JP5637352B2 - Vehicle headlamp - Google Patents

Description

  The present invention relates to a vehicle headlamp, and more particularly to a vehicle headlamp capable of improving the visibility (awareness) of surrounding pedestrians and obstacles in an actual traffic environment.

  Conventionally, in the field of headlamps, it has been demanded to improve the brightness so that it can be driven at night as well as in the daytime. In order to meet this demand, a high luminous flux light source such as a halogen lamp or an HID lamp is used to provide an optical system. Various headlamps have been proposed with the aim of improving brightness such as improving the brightness (see, for example, Patent Document 1 and Patent Document 2).

JP 2007-59162 A Japanese Patent Laid-Open No. 11-273407

  However, cones that are densely located in the central part of the retina and capture the color of the central part of the field of view in bright places, rods that are distributed in the peripheral part of the retina and function in dark places, central vision, peripheral vision, color matching functions, specific visual sensitivity curves, etc. When the visual characteristics based on the above are taken into consideration (see FIGS. 56 to 59), the visibility (awareness) of surrounding pedestrians and obstacles in the actual traffic environment should be affected by these visual characteristics, Simply turning the power on and making the headlamps brighter goes against social trends that focus on environmental issues, and more efficiently improves the visibility (awareness) of surrounding pedestrians and obstacles. There is also a problem of going backwards in improving performance.

  The present invention has been made in view of such circumstances, and provides a vehicle headlamp capable of improving the visibility (awareness) of surrounding pedestrians and obstacles in an actual traffic environment. For the purpose.

In order to solve the above-mentioned problem, the invention according to claim 1 is configured to irradiate with light used for forming a partial light distribution pattern constituting a low-beam light distribution pattern in a predetermined white range. In the vehicle headlamp including one headlamp unit, the headlamp unit includes an LED light source, a light incident surface on which light emitted from the LED light source enters the lens, an output surface, and the light incident surface. A solid lens body comprising: a reflection surface configured to internally reflect light incident on the lens, and the reflected light is emitted from the emission surface to form a predetermined light distribution pattern having a light / dark boundary line; The reflecting surface is radiated from one side of the LED light source corresponding to the light / dark boundary line, enters the light incident surface perpendicularly, and enters the lens without being refracted. A first reflection region configured to internally reflect light of a reference wavelength and emit the reflected light from the emission surface to form the light / dark boundary line, and radiate from one side of the LED light source corresponding to the light / dark boundary line The light incident on the light incident surface at a non-perpendicular angle, refracted according to the incident angle, and internally reflected light having a wavelength longer than a reference wavelength incident on the inside of the lens, and the reflected light is emitted from the light exit surface. A second reflection region configured to be distributed below the light-dark boundary, and an incident angle that is emitted from one side of the LED light source corresponding to the light-dark boundary and is incident on the light incident surface at a non-perpendicular angle. And a light having a wavelength shorter than a reference wavelength incident on the inside of the lens is refracted in response to the light, and the reflected light is emitted from the emission surface and is distributed below the bright / dark boundary line. And a reflective area The LED light source, color temperature from 4,500 to 7000 [K], and 4-color four coordinate values representing the prediction of the definitive appearance when irradiated with color chips (red, green, blue and yellow) (a *, b *) is a coordinate value R (41.7, 20.9), G (-39.5 on the a * -b * coordinate system where the vertical axis corresponding to the CIE1976L * a * b * space is a * and the horizontal axis is b *. , 14.3), B (8.8, -29.9), LED light source der contained in a circle within a radius of 5 centered on the Y (-10.4,74.2) is, the LED light source, a blue or ultraviolet LED element and the wavelength Using a white LED light source containing a conversion material, or an LED light source combining LEDs of three colors of red, green, and blue, the coordinate values on the xy chromaticity coordinates (0.323, 0.352), (0.325, 0.316), ( 0.343, 0.331), (0.368, 0.379) is irradiated with white light in a chromaticity range surrounded by a straight line .

  The conditions described in claim 1 were found as a result of an experiment conducted by the inventors of the present application. According to the invention described in claim 1, in the actual traffic environment (especially when turning right at an intersection). Visibility (awareness) of surrounding pedestrians and obstacles can be improved.

  Conventionally, in the field of vehicular lamps using LED light sources, as shown in FIG. 74, vehicular lamps 400 using an optical unit including an LED light source 410 and a light guide 420 are known (for example, special features No. 2008-78086).

  The light guide 420 of the vehicle lamp 400 described in the publication includes a reflection surface 421 that internally reflects light emitted from the LED light source 410 and incident inside, and emits light reflected internally by the reflection surface 421. The light distribution pattern is emitted from the surface 422 and has a light / dark boundary line.

  However, the vehicular lamp 400 described in the same publication has a problem that the vicinity of the bright / dark boundary line is colored in a rainbow shape (color blur occurs) due to the influence of chromatic aberration. This coloring (color blur) is particularly noticeable when the light guide is formed using a transparent resin material having a relatively high refractive index, such as acrylic or polycarbonate.

  On the other hand, according to the first aspect of the present invention, from the LED light source that causes rainbow-like coloring near the light / dark boundary line that is refracted according to the incident angle to the light incident surface and enters the lens. Light (light having a shorter wavelength than the reference wavelength and light having a longer wavelength) is distributed below the light / dark boundary line by the action of the second reflective region and the third reflective region. It becomes possible to prevent or reduce iridescent coloring.

According to a second aspect of the present invention, in the first aspect of the invention, the second reflection region internally reflects light having a wavelength longer than a reference wavelength incident on the lens, and the reflected light is emitted from the emission surface. And is distributed so as to be distributed on the light / dark boundary line or in the predetermined light distribution pattern,
The third reflection region internally reflects light having a wavelength shorter than a reference wavelength incident on the lens, and the reflected light is emitted from the emission surface and is distributed on the light / dark boundary line or in the predetermined light distribution pattern. It is comprised so that it may be comprised.

  According to the second aspect of the present invention, light that is refracted according to the incident angle to the light incident surface and is incident on the inside of the lens and causes rainbow-like coloring near the light-dark boundary line (wavelength shorter than the reference wavelength) Light and long wavelength light) are distributed on the light / dark boundary line or within the predetermined light distribution pattern by the action of the second reflection region and the third reflection region, thereby preventing or reducing color unevenness in the predetermined light distribution pattern. It becomes possible to do.

  According to a third aspect of the present invention, in the first or second aspect of the invention, the reflection surface causes light emitted from an end portion of the LED light source to enter the light / dark boundary line and the predetermined light distribution pattern. It is formed so as to be emitted from the emission surface in a spreading direction, whereby light emitted from the end portion of the LED light source is transmitted from a point on the light emission surface other than the end portion on the light emission surface of the LED light source. It is characterized by being formed so as to be superimposed on the emitted light.

  According to the third aspect of the present invention, the light emitted from the end portion of the LED light source is mixed with the light emitted from a point other than the end portion of the LED light source. It is possible to prevent or reduce color unevenness of the predetermined light distribution pattern.

It invention of claim 4 is the invention according to any one of claims 1 to 3, wherein the LED light source, the color temperature is an LED light source that the light emission in the range of 5000-6000 [K] It is characterized by .

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the headlamp for vehicles which can improve the visibility (awareness) with respect to the surrounding pedestrian, an obstruction, etc. in an actual traffic environment.

It is a figure for demonstrating the white range A1 of the headlamp prescribed | regulated by the regulation. It is a figure for demonstrating the apparatus structure used for the experiment 1 for clarifying the white range favored as light of a headlamp. (A) The figure which plotted the measurement result (group 1) of experiment 1 on xy chromaticity coordinates, (b) (a) The figure which plotted the measurement result (group 2) of experiment 1 on xy chromaticity coordinates. . (A) The figure which plotted the measurement result (group 1) of experiment 1 on xy chromaticity coordinates, (b) (a) The figure which plotted the measurement result (group 2) of experiment 1 on xy chromaticity coordinates. . (A) The figure which plotted the measurement result (group 1) of experiment 1 on xy chromaticity coordinates, (b) (a) The figure which plotted the measurement result (group 2) of experiment 1 on xy chromaticity coordinates. . (A) The figure which plotted the measurement result (group 1) of experiment 1 on xy chromaticity coordinates, (b) (a) The figure which plotted the measurement result (group 2) of experiment 1 on xy chromaticity coordinates. . The figure for demonstrating the approximate range accept | permitted as the light of a headlamp clarified from the measurement result (group 1) of experiment 1, (b) The head clarified from the measurement result (group 2) of experiment 1 It is a figure for demonstrating the approximate range accept | permitted as the light of a lamp | ramp. It is a figure for demonstrating the white range A2 preferred as the light of the headlamp which became clear from Fig.7 (a) (b). To explain that in an actual traffic environment (especially when turning right at an intersection), the driver recognizes surrounding pedestrians and obstacles with peripheral vision while viewing the oncoming vehicle V1 with central vision. FIG. It is a figure for demonstrating the apparatus structure used for the experiment 2 for clarifying the white range (chromaticity range of the light color as a headlamp) which can improve the visibility (awareness) by peripheral vision. . It is a figure for demonstrating the correlation chromaticity etc. of the light source used for experiment 2 grade | etc.,. It is the graph which plotted the relationship between the reaction time measured by Experiment 2, and the presentation position for every light source. (A) Table which evaluated each light source based on reaction time etc., (b) It is a graph showing the relationship between each light source and evaluation score. It is the graph which plotted the relationship between the miss rate calculated based on the reaction time measured by Experiment 2, and the presentation position for each light source. It is a figure for demonstrating the concept of the reaction number ratio. It is a graph showing the relationship between the reaction number ratio of the light source (luminance: 1 cd / m < ² >) used for Experiment 2, and reaction time. It is a graph showing the relationship between the reaction number ratio of the light source (luminance: 0.1 cd / m < ² >) used for Experiment 2, and reaction time. It is a graph showing the relationship between the reaction number ratio of the light source (luminance: 0.01 cd / m < ² >) used for Experiment 2, and reaction time. It is the graph which averaged the graph shown in FIGS. It is a graph for demonstrating that the visibility (awareness) by peripheral vision is improving, so that the light source with high color temperature is related to the awareness with respect to white light. It is a figure for demonstrating the apparatus structure used for the experiment 3 for clarifying whether there exists a difference in the visibility (awareness) by peripheral vision with respect to colors other than white. It is a graph showing the relationship between the reaction number ratio of the light source used for Experiment 3, and reaction time. It is the graph which plotted the reciprocal number of the average reaction time with respect to the color material of the light source used for Experiment 3 in the coordinate system which is Yellow on the + side of a vertical axis | shaft, Blue on the negative side, Red on the horizontal side, and Green on the-side. It is the graph which averaged four graphs shown in FIG. It is a graph showing the relationship between each light source and an evaluation score. It is a graph for demonstrating the fact that the sensitivity with respect to a specific wavelength (450-550 nm) becomes high compared with the state of photopic vision in the state of scotopic vision (the state of twilight vision is the same). It is a figure for demonstrating the fact that there exists a tendency for a radiant energy component ratio to become high, so that a light source with high color temperature. It is a figure for demonstrating white range A3 (chromaticity range of the light color as a headlamp) which can improve the visibility (perception) by peripheral vision. It is a figure for demonstrating that it is LED whose color temperature is 5000 [K] or more that notice time is shorter than TH and HID. It is a figure for demonstrating the area | region etc. from which the relationship with notice is not clarified by Experiment 2 and Experiment 3. FIG. It is the graph which plotted for each light source the relationship between the miss rate calculated based on the reaction time measured by the additional experiment (ratio which passed 2 second or more to notice presentation light), and the presentation position. It is a graph showing the relationship between the reaction number ratio of the light source (luminance: 1 cd / m < ² >) used for the additional experiment, and reaction time. It is a graph showing the relationship between the reaction number ratio of the light source (luminance: 0.1 cd / m < ² >) used for the additional experiment, and reaction time. It is a graph showing the relationship between the reaction number ratio of the light source (luminance: 0.01 cd / m < ² >) used for the additional experiment, and reaction time. It is the graph which averaged the graph shown in FIGS. It is a figure for demonstrating the white range (chromaticity range of the light color as a headlamp) which can improve the visibility (awareness) by peripheral vision. Prediction of the appearance of four colors (red, green, blue, yellow) for each TH, HID, LED (T9) calculated by using a known formula based on the spectrum of TH, HID, LED (T9) The four coordinate values are represented by the a ^* -b ^* coordinate system corresponding to the CIE1976L * a * b * space (a ^* is in the red direction, -a ^* is in the green direction, b ^* is in the yellow direction, and -b ^* is in the blue direction. It is a graph plotted in FIG. Other than the LED (T9), other LEDs (T6, T7, etc.) have four coordinate values R (41.7,20.9), G (-39.5,14.3), B (8.8, -29.9), Y (-10.4, 74.2) is a diagram for explaining that it is included in a circle range with a radius of 5 centering on Y. It is a figure for demonstrating arrangement | positioning etc. of the headlamp 10 of this embodiment. It is an enlarged view of the headlamp 10 arrange | positioned on the left side. It is an example of the light distribution pattern formed on a vertical screen by the headlamp 10 arrange | positioned at the left side. It is a figure for demonstrating that the light source with a high ratio of a radiant energy component has little fall of reaction time, even if a brightness | luminance becomes low. It is a figure for demonstrating that the light source with a high ratio of a radiant energy component has little fall of reaction time, even if a brightness | luminance becomes low. It is a figure for demonstrating that the light source with a high ratio of a radiant energy component has little fall of reaction time, even if a brightness | luminance becomes low. It is a figure for demonstrating that the light source with a high ratio of a radiant energy component has little fall of reaction time, even if a brightness | luminance becomes low. It is the light distribution pattern (luminous intensity distribution) formed on the vertical screen by the headlamp 10 of this embodiment. It is a light distribution pattern (light intensity distribution) formed on the vertical screen by the headlamp of Conventional Example 1. It is a road surface light distribution pattern (equal illumination distribution) formed on the road by the headlamp 10 of the present embodiment. It is a road surface light distribution pattern (equal illumination distribution) formed on the road by the headlamp of Conventional Example 1. It is a road surface light distribution pattern (equal illumination distribution) formed on the road by the headlamp of Conventional Example 2. It is the graph which put together the evaluation result of run ease. It is a figure for demonstrating the arrangement | positioning location of the color mark C1. It is the graph which put together the evaluation result of the visibility of the color at the time of driving | running | working. (A) The figure for demonstrating the arrangement | positioning locations, such as color target C2, (b) The table | surface for demonstrating the arrangement locations, such as color target C2. It is the graph which put together the evaluation result of the visibility of the color in the scene at the time of the intersection right turn. It is a figure for demonstrating the visual characteristic based on a cone, a rod, central vision, peripheral vision, etc. FIG. It is a figure for demonstrating the visual characteristic based on a cone, a rod, central vision, peripheral vision, etc. FIG. It is a figure for demonstrating the visual characteristic based on a cone, a rod, central vision, peripheral vision, etc. FIG. It is a figure for demonstrating the visual characteristic based on a cone, a rod, central vision, peripheral vision, etc. FIG. It is a front view of the conventional vehicle lamp which has arrange | positioned the some optical unit in the upper and lower two steps. It is an example of the light distribution pattern for low beams formed with the conventional vehicle lamp of FIG. FIG. 61 is a diagram for explaining that a step (illuminance unevenness) occurs in an illuminance cross section in the conventional vehicle lamp of FIG. 60. FIG. 61 is a diagram for explaining that a step (illuminance unevenness) occurs in an illuminance cross section in the conventional vehicle lamp of FIG. 60. This is an example (Modification 1) in which a plurality of headlamp units 10A to 10D are arranged in a state in which the light emission range is not adjacent to the vertical direction but adjacent to the vehicle width direction when viewed from the front. The arrangement of the headlamp units 10A to 10D shown in FIG. 64 makes it possible to prevent the difference in illuminance cross section (illuminance unevenness) due to the difference in mounting height between the upper optical unit and the lower optical unit. It is a figure for demonstrating. It is a figure for demonstrating the light distribution pattern PLA obtained by the optical unit 10A. This is an example (Modification 2) in which a plurality of headlamp units 10A to 10D are arranged in a state where the light emission range is not adjacent to the vertical direction but adjacent to the vehicle width direction when viewed from the front. The arrangement of the headlamp units 10A to 10D shown in FIG. 67 makes it possible to prevent a step in the illuminance section (illuminance unevenness) due to a difference in mounting height between the upper optical unit and the lower optical unit. It is a figure for demonstrating. This is an example (Modification 3) in which a plurality of headlamp units 10A to 10D are arranged in a state where the light emission range is not adjacent to the vertical direction but adjacent to the vehicle width direction when viewed from the front. The arrangement of the headlamp units 10A to 10D shown in FIG. 69 makes it possible to prevent a difference in illuminance cross section (illuminance unevenness) due to a difference in mounting height between the upper optical unit and the lower optical unit. It is a figure for demonstrating. This is an example in which the plurality of headlamp units 10A to 10D are arranged in a state where the light emission range is not adjacent to the vertical direction but adjacent to the vehicle width direction when viewed from the front. It is an example of the general light distribution pattern for low beams. It is a figure for demonstrating the emission angle x of the light beam which forms the upper end of a light distribution pattern. It is a structural example of the vehicle lamp 300 using the optical unit containing the conventional LED light source 310 and the light guide 320. FIG. 2 is a front view of a headlamp 50. FIG. FIG. 76 is a diagram for describing a configuration of a lens body 52 (Modification 4) used in the headlamp 50 of FIG. 75. It is an example of the light distribution pattern formed with the headlamp 50 of FIG. It is a figure for demonstrating that the illumination area | region Q which color-separated unintentionally formed in the whole upper side of the light-dark boundary line CL by color separation. In the light distribution pattern P of the headlamp 50 of FIG. 76 configured by the light source units 50A to 50D, the measurement point is fixed in the direction of 1 degree downward from the H line with respect to the vertical direction, and the measurement point is on the V line with respect to the horizontal direction. It is the measured value table | surface which showed the result of having actually measured the chromaticity and the luminous intensity in the measurement points L0-L6 from 0 degree to 30 degree | times shifted leftward from 5 degree | times to 0 degree. Based on the actual value table in FIG. 79, actual values relating to the chromaticity at each measurement point are shown on the chromaticity diagram of the CIE color system. Based on the actual value table in FIG. 79, actual values relating to the chromaticity at each measurement point are shown on the chromaticity diagram of the CIE color system. FIG. 76 is a diagram for describing a configuration of a lens body 52 (Modification 5) used in the headlamp 50 of FIG. 75. FIG. 76 is a diagram for describing a configuration of a lens body 52 (Modification 6) used in the headlamp 50 of FIG. 75. It is a figure for demonstrating the example of LED51. 84A and 84B are diagrams showing packaging of LED chips having different forms using the same LED chip 200 as in FIG. 84, where FIG. 11A is a plan view and FIG. 8B is a BB line in FIG. A cross-sectional view and FIG. 10C are cross-sectional views taken along line AA in FIG.

  The conditions for improving the visibility (awareness) of surrounding pedestrians and obstacles in the actual traffic environment (especially when turning right at the intersection) will be clarified below.

[White range preferred for headlamp light]
The white range A1 of the headlamp (the chromaticity range of the light color as the headlamp) is defined by law (see FIG. 1). However, the headlight white range A1 (coordinate values on xy chromaticity coordinates (0.31,0.28), (0.44,0.38), (0.50,0.38), (0.50,0.44), (0.455,0.44) ), (0.31,0.35) is a chromaticity range surrounded by a straight line), which is determined regardless of whether it is preferred as light of the headlamp. It is not always preferred as light. Therefore, the inventor of the present application conducted the following experiment in order to clarify the white range preferred as the headlamp light in the white range A1 defined by the law.

[Experiment 1]
Experimental environment: A dark room in which RGB (red, green, blue) LEDs and a diffusion board that diffuses light emitted from the LEDs were arranged was used (see FIG. 2). There are 6 subjects, 3 in Group 1 and 3 in Group 2.

  Experimental procedure: The light source color for controlling the LED and illuminating the diffusion board is gradually changed in the direction of the arrow shown in FIGS. 3 (a) (b) to 6 (a) (b), through the opening of the dark room. When the stimulus light to be presented entered the subject's favorite white range, the push button was pressed, and the chromaticity at the time when the push button was pressed was measured.

  As a result of plotting the above measurement results on the xy chromaticity coordinates (see FIGS. 3 (a) (b) to 6 (a) (b)) and examining, there is an approximate range allowed as light of the headlamp. It becomes clear (see FIGS. 7 (a) and 7 (b)), and the white range (the chromaticity range of the light color as the headlamp) preferred as the light of the headlamp is a coordinate value on the chromaticity coordinates shown in FIG. It became clear that it was the chromaticity range A2 surrounded by P1 to P4.

[White range that can improve visibility (perception) by peripheral vision]
In an actual traffic environment (especially when turning right at an intersection), as shown in FIG. 9, in general, the driver visually recognizes the oncoming vehicle V1 in the central view, while seeing surrounding pedestrians and obstacles in the peripheral view. It seems that they are aware.

  The inventor of the present application is able to improve the visibility (awareness) by peripheral vision among the white range A2 preferred as the light of the above-described headlamp (the chromaticity of the light color as the headlamp). The following experiment was conducted to clarify the range.

[Experiment 2]
Experimental environment: An apparatus having the configuration shown in FIG. 10 was used, and a plurality of light sources (T1 to T11, TH, HID) having different correlated color temperatures were used as the light source of the presenting light as shown in FIG. T1 to T11 represent LEDs, TH represents a halogen lamp, and HID represents an HID lamp. There are 18 subjects.

Experimental procedure: While the subject is gazing at the display (the hiragana is displayed) 2 m in front, the left (or right) 30 °, 45 °, 60 °, and 75 ° positions with respect to the front The gray color materials irradiated by the light sources (T1 to T11, TH, HID) adjusted to a constant luminance (1, 0.1 cd / m ² ) at (angular position) are sequentially presented, and each light source and presentation position is presented. The time (reaction time) until the subject visually recognizes (notices) the presented light (reflected light from the gray color material) was measured.

[Reaction time for each light source and presentation position]
FIG. 12 is a graph in which the relationship between the reaction time measured in Experiment 2 and the presentation position is plotted for each light source. FIG. 13A (column of “reaction time”) is a table in which each light source is evaluated based on the reaction time. A light source with a shorter reaction time can be said to have improved visibility (awareness) in peripheral vision. Therefore, a higher evaluation score was assigned to a light source with a shorter reaction time.

  Referring to FIG. 12 and FIG. 13A (column of “Reaction time”), the light source having a higher color temperature tends to have a shorter reaction time (higher evaluation score), that is, the color regarding the awareness of white light. It can be seen that the higher the temperature of the light source, the better the visibility (awareness) by peripheral vision.

[Missing rate]
FIG. 14 is a graph in which the relationship between the missed rate calculated based on the reaction time measured in Experiment 2 (the rate at which 2 seconds or more have passed to notice the presented light) and the presented position is plotted for each light source. FIG. 13A (column of “missing rate”) is a table in which each light source is evaluated based on the missing rate. Since it can be said that the visibility (awareness) of peripheral vision is improved with a light source with a small miss rate, a higher evaluation score is assigned to a light source with a small miss rate.

  Referring to FIG. 14 and FIG. 13A (column of “missing rate”), the light source having a higher color temperature tends to have a smaller missing rate (higher evaluation score), that is, color awareness regarding white light. It can be seen that the higher the temperature of the light source, the better the visibility (awareness) by peripheral vision.

[Reaction number ratio]
FIG. 15 is a diagram for explaining the concept of the reaction number ratio. The ratio of the number of reactions means (number of reactions up to a certain time) / (number of data with a reaction time of 2 seconds or less out of the total number of reactions). The time that half of the subjects noticed was evaluated as the response time to the light source. The reaction time of 2 seconds or longer was defined as missed.

FIG. 16 is a graph showing the relationship between the reaction number ratio of the light source (luminance: 1 cd / m ² ) used in Experiment 2 and the reaction time.

  Referring to Figure 16, the order in which the reaction rate ratio reaches 0.5 is T10⇒T8⇒T5⇒T3⇒T7⇒T9⇒T6⇒HID⇒T11⇒T2⇒T1⇒TH⇒T4. From the above, it can be seen that the light source with a higher color temperature tends to have a shorter reaction time until the reaction rate ratio reaches 0.5, that is, the light source with a higher color temperature has a higher visibility due to peripheral vision. It can be seen that (Awareness) has improved.

FIG. 17 is a graph showing the relationship between the reaction number ratio of the light source (luminance: 0.1 cd / m ² ) used in Experiment 2 and the reaction time.

  Referring to FIG. 17, the order in which the reaction rate ratio reaches 0.5 is T8⇒T5⇒T7⇒HID⇒T9⇒T6⇒T11⇒T1⇒T10⇒T3⇒T4⇒T2⇒TH. From the above, it can be seen that the light source with a higher color temperature tends to have a shorter reaction time until the reaction rate ratio reaches 0.5, that is, the light source with a higher color temperature has a higher visibility due to peripheral vision. It can be seen that (Awareness) has improved.

FIG. 18 is a graph showing the relationship between the reaction number ratio of the light source (luminance: 0.01 cd / m ² ) used in Experiment 2 and the reaction time.

  Referring to FIG. 18, the order in which the reaction rate ratio reaches 0.5 is T5⇒T8⇒T9⇒HID⇒T11⇒T10⇒T6⇒T2⇒T7⇒T3⇒T1⇒T3⇒TH. From the above, it can be seen that the light source with a higher color temperature tends to have a shorter reaction time until the reaction rate ratio reaches 0.5, that is, the light source with a higher color temperature has a higher visibility due to peripheral vision. It can be seen that (Awareness) has improved.

  FIG. 19 is a graph obtained by averaging the graphs shown in FIGS. FIG. 13A (column of “reaction number ratio”) is a table in which each light source was evaluated based on the reaction time until the reaction number ratio 0.5 was reached. Since it can be said that the visibility (awareness) by peripheral vision is improved as the light source has a shorter reaction time until reaching the reaction number ratio 0.5, the light source has a shorter reaction time until the reaction number ratio 0.5 is reached. A higher evaluation score was assigned.

  Referring to Fig. 19 and Fig. 13 (a) ("Reaction number ratio" column), the order in which the reaction number ratio reaches 0.5 is T8⇒T5⇒HID⇒T9⇒T10⇒T7⇒T11⇒T6⇒ T2⇒T1⇒T3⇒T4⇒TH in this order. From this, the light source with higher color temperature tends to have a shorter reaction time until reaching the reaction number ratio 0.5, that is, for white light With regard to awareness, it can be seen that the light source having a higher color temperature has improved visibility (awareness) in peripheral vision.

  When each light source is comprehensively evaluated based on the total points of the reaction time, reaction rate ratio, and miss rate (see FIGS. 13 (a) and 13 (b)) that are scored as described above, It can be seen that the higher the temperature of the light source, the better the visibility (awareness) by peripheral vision (see FIG. 20).

[Awareness of color materials]
In an actual traffic environment, it is not only white light that is irradiated and reflected from the headlamp. The inventor of the present application conducted the following experiment in order to clarify whether there is a difference in visibility (awareness) in peripheral vision for colors other than white.

[Experiment 3]
Experimental environment: A device having the configuration shown in FIG. 21 was used, and a plurality of light sources (T5, T6, T7, T9, TH, HID) having different correlated color temperatures were used as the light source of the presenting light as shown in FIG. T5, T6, T7, and T9 represent LEDs, TH represents a halogen lamp, and HID represents an HID lamp. There are 18 subjects.

  Experimental procedure: While the subject is gazing at the display (the hiragana is displayed) 2 m in front, the left (or right) 30 °, 45 °, 60 °, and 75 ° positions with respect to the front The color materials (red / green / blue / yellow) irradiated by the light source (T5, T6, T7, T9, TH, HID) adjusted to a constant luminance at (angular position) are sequentially presented, the light source, the presentation position, For each color material, the time (reaction time) until the subject visually recognizes (notices) the presented light was measured.

  FIG. 22 is a graph showing the relationship between the reaction number ratio of the light source used in Experiment 3 and the reaction time.

  Referring to FIG. 22, regarding the awareness of the color material, it can be seen that the light source having a short reaction time until reaching the reaction number ratio of 0.5 is the LED (T9).

  FIG. 23 plots the reciprocal of the average reaction time for the light source color material used in Experiment 3 in a coordinate system in which the positive side of the vertical axis is Yellow, the negative side is Blue, the positive side of the horizontal axis is Red, and the negative side is Green. It is a graph. It shows that the visibility (awareness) by the peripheral vision is improved as the light source having a larger diamond connecting the coordinate values.

  FIG. 24 is a graph obtained by averaging the four graphs shown in FIG. Referring to FIG. 24, the LED has a larger rhombus connecting the coordinate values than TH and HID, that is, the awareness of color (coloring material), and visibility (awareness) by peripheral vision rather than TH and HID. It can be seen that is improved.

  When the results of Experiment 2 and Experiment 3 are combined, regarding the awareness of white light and color (coloring material), the light source with a higher color temperature tends to have a higher evaluation score, and the visibility (awareness) by peripheral vision is improved. (See FIG. 25). This is due to the fact that the sensitivity to a specific wavelength (450 to 550 nm) is higher in the scotopic state (similar to the twilight state) (see FIG. 26), and the light source has a high color temperature. This is consistent with the fact that the radiant energy component ratio (see FIG. 26 for the definition of the radiant energy component ratio) tends to be high (see FIG. 27).

  Summing up the above, FIG. 28 shows the white range (the chromaticity range of the light color as a headlamp) that can improve the visibility (awareness) by peripheral vision regarding the awareness of white light and color (coloring material). It can be seen that the chromaticity range A3 is surrounded by the coordinate values P1, P2, P5, and P6 on the xy chromaticity coordinates shown.

  This chromaticity range A3 (see FIG. 28), the facts made clear above (the light source having a higher color temperature improves the visibility (awareness) by peripheral vision. See FIGS. 13 (a) and 13 (b)), Furthermore, considering that LEDs that have a color temperature of 5000 [K] or higher are shorter than TH and HID (see FIG. 29), the conditions for improving the visibility (awareness) of peripheral vision are One shows that the color temperature is 5000 to 6000 [K].

  The inventor of the present application has a region (see FIG. 30) in the white range A2 that is preferred as the light of the above-described headlamp, in which the relationship with the awareness is not clarified by the experiments 2 and 3 (see FIG. 30) In order to clarify whether it is possible to improve visibility (awareness) by visual observation, the following additional experiment was conducted.

[Additional experiment]
Experimental environment: Using the apparatus having the configuration shown in FIG. 10, as the light source of the presenting light, a plurality of light sources (T1 to T11, TH, HID) having different correlated color temperatures as shown in FIG. 11, and the correlated color shown in FIG. Temperature LEDs (T15, T17) were used. T1 to T11, T15, and T16 are LEDs, TH is a halogen lamp, and HID is an HID lamp. There are 18 subjects.

Experimental procedure: While the subject is gazing at the display (the hiragana is displayed) 2 m in front, the left (or right) 30 °, 45 °, 60 °, and 75 ° positions with respect to the front The light source (T1 to T11, T15, T17, TH, HID) adjusted to a constant luminance (1, 0.1 cd / m ² ) is sequentially presented at (angular position), and the subject presents light for each light source and presentation position. The time (reaction time) to visually recognize (recognize) was measured.

[Reaction time for each light source and presentation position]
Since the relationship between the reaction time measured by the additional experiment and the presentation position is the same as in Experiment 2 (see FIG. 12), the description thereof is omitted.

[Missing rate]
FIG. 31 is a graph in which the relationship between the missed rate calculated based on the reaction time measured by the additional experiment (the rate at which 2 seconds or more have passed to notice the presented light) and the presented position is plotted for each light source. After correcting the reaction time data based on HID, the miss rate was calculated.

  Referring to FIG. 31, it can be seen that the LED (T15) corresponds to a missing rate comparable to that of a light source having a low color temperature.

[Reaction number ratio]
FIG. 32 is a graph showing the relationship between the reaction number ratio of the light source (luminance: 1 cd / m ² ) used in the additional experiment and the reaction time. After correcting the reaction time data based on HID, the reaction number ratio was calculated.

  Referring to FIG. 32, the order in which the reaction rate ratio reaches 0.5 is as follows: T10 → T8 → T5 = T3 = T7 = T6 = HID = T9 = T11 = T15 → T2 → T17 → T1 → TH → T4 It turns out that it is.

FIG. 33 is a graph showing the relationship between the reaction number ratio of the light source (luminance: 0.1 cd / m ² ) used in the additional experiment and the reaction time. After correcting the reaction time data based on HID, the reaction number ratio was calculated. Referring to FIG. 33, the order in which the reaction rate ratio reaches 0.5 is as follows: T8 → T7 = T5 = HID = T15 = T6 → T11 → T9 → T1 → T10 → T3 → T17 → T4 → T2 → TH It turns out that it is.

FIG. 34 is a graph showing the relationship between the reaction number ratio of the light source (luminance: 0.01 cd / m ² ) used in the additional experiment and the reaction time. After correcting the reaction time data based on HID, the reaction number ratio was calculated. Referring to FIG. 34, the order in which the reaction rate ratio reaches 0.5 is as follows: T5 → T8 = T9 = HID = T11 = T15 = T10 → T6 → T2 → T7 → T4 → T1 → T17 → T3 → TH It turns out that it is.

  FIG. 35 is a graph obtained by averaging the graphs shown in FIGS. Referring to FIG. 35, the order in which the reaction ratio reaches 0.5 is as follows: T5 → T8 → T9 = HID = T10 = T7 = T11 = T6 = T15 → T2 → T1 → T3 → T4 → T17 → TH That is, it can be seen that the reaction time of H15 is almost equal to that of HID.

  As a result of the additional experiment, it has been clarified that the reaction time of the LED (T15) is equivalent to that of a light source having a high color temperature, and the reaction time of the LED (T17) behaves similarly to a light source having a low color temperature. .

  Combining the results of Experiment 1 to Experiment 3 and the additional experiment, the white range (the chromaticity range of the light color as the headlamp) that can improve the visibility (awareness) by peripheral vision is shown in FIG. It can be seen that the chromaticity range A4 is surrounded by a straight line connecting the coordinate values (0.323, 0.352), (0.325, 0.316), (0.343, 0.331), and (0.368, 0.379) on the chromaticity coordinates.

  This chromaticity range A4 (see FIG. 36) and the above-described fact (the light source having a higher color temperature improves visibility (awareness) in peripheral vision. See FIGS. 13 (a) and 13 (b)). In consideration, it can be seen that one of the conditions for improving the visibility (awareness) by peripheral vision is a color temperature of 4500 to 7000 [K].

[Prediction of color appearance]
Even if they are the same color, they look different if the light source is different. It is generally explained that this is due to the change in the spectral distribution of the light source and the fact that the eyes get used to it (adaptation) when the light source color changes. The color appearance is not completely but can be predicted by using a known formula.

FIG. 37 shows the appearance of four colors (red, green, blue, and yellow) for each TH, HID, and LED (T9) calculated using known formulas based on the respective spectra of TH, HID, and LED (T9). The four coordinate values representing the prediction of the direction are represented by the a ^* -b ^* coordinate system corresponding to the CIE1976L * a * b * space (a ^* is in the red direction, -a ^* is in the green direction, b ^* is in the yellow direction, -b ^(* Represents the blue direction). This represents prediction about the appearance of the color for each TH, HID, and LED (T9). In FIG. 37, the closer each coordinate value is to 100 (that is, the light source having a larger rhombus connecting the four coordinate values), the more the color (color chart) looks like the reference light source (sunlight, color temperature: 6500 [K ]) Approaching the appearance under illumination (that is, the color can be reproduced more faithfully).

  Referring to FIG. 37, the LED (T9) has four coordinate values R (41.7, 20.9), G (-39.5, 14.3), B (8.8, -29.9), Y (-10.4, compared with TH and HID. 74.2) is large, that is, the appearance of the color (color chart) under the illumination of the LED (T9) is the appearance of the color (color table) under the illumination of the standard light source compared to TH and HID It can be seen that it is closer (that is, the color can be reproduced more faithfully).

  Referring to FIG. 38, other LED (T6, T7, etc.) other than LED (T9) have four coordinate values R (41.7, 20.9), G (-39.5, 14.3). ), B (8.8, -29.9), Y (-10.4,74.2) is included in a circle with radius 5 and has four coordinate values compared to TH and HID, similar to LED (T9). Is large, that is, the appearance of the color (color table) under illumination of other LEDs (T6, T7, etc.) other than LED (T9) is also under the illumination of a standard light source compared to TH and HID It can be seen that the color (color table) is closer to the appearance (that is, the color can be reproduced more faithfully).

In summary, the four coordinate values representing the prediction of the appearance of the four colors (red, green, blue, yellow) are coordinate values on the a ^* -b ^* coordinate system corresponding to the CIE1976L * a * b * space. It is possible to use an LED light source included in a circular range with a radius of 5 centered on R (41.7,20.9), G (-39.5,14.3), B (8.8, -29.9), Y (-10.4,74.2). It can be seen that this is a condition for reproducing the image more faithfully.

  This condition is that the white range that can improve the visibility (awareness) by peripheral vision is the chromaticity range A3 (or chromaticity range A4), and the fact that has been clarified above (light source with high color temperature) Considering that the visibility (awareness) by peripheral vision is improved, see FIGS. 13 (a) and 13 (b)), which is one of the conditions for improving the visibility (awareness) by peripheral vision. It can be said that it can be said.

In summary, the conditions for improving the visibility (awareness) of peripheral vision are: a color temperature of 4500 to 7000 [K] (preferably 5000 to 6000 [K]), and four colors (red, green, The four coordinate values representing the prediction of the appearance of blue and yellow) are the coordinate values R (41.7,20.9), G (-39.5,) on the a ^* -b ^* coordinate system corresponding to the CIE1976L * a * b * space. 14.3), B (8.8, -29.9), Y (-10.4, 74.2), it turns out that it is using the LED light source (or light source equivalent to this) contained in the circle | round | yen range of radius 5. More preferably, the light color as the headlamp is surrounded by a straight line connecting the coordinate values (0.323, 0.352), (0.325, 0.316), (0.343, 0.331), (0.368, 0.379) on the xy chromaticity coordinates. It can be seen that the chromaticity range is A4 (see FIG. 36).

  As a light source satisfying these conditions, for example, there are LEDs (T6, T7, T9) having correlated color temperatures shown in FIG.

  Note that it is known that the LED is about 10% brighter than the TH and HID in the dark place vision state (similar to the twilight vision state). From this point also, the LED light source is used as the light source of the headlamp 10. 11 may be advantageous.

[Configuration of headlamp]
Next, a description will be given of a configuration example of a headlamp that satisfies the conditions for improving the visibility (awareness) of the above-described peripheral vision.

  As shown in FIG. 39, the headlamp 10 of the present embodiment is disposed on each of the left and right sides of the front portion of the vehicle. Since the left and right headlamps 10 are symmetrical and have the same configuration, the left headlamp 10 will be mainly described below.

  FIG. 40 is an enlarged view of the headlamp 10 arranged on the left side.

  The headlamp 10 of this embodiment has a configuration in which four headlamp units 10A to 10D (hereinafter also referred to as optical units) are arranged in a horizontal direction (vehicle width direction).

  The headlamp units 10 </ b> A to 10 </ b> D include, as a common configuration, an LED light source 11, a lens body 12 disposed in front of the LED light source 11, a heat sink 13 for heat dissipation to which a substrate on which the LED light source 11 is mounted is fixed. ing.

The LED light source 11 is an LED light source that satisfies the conditions for improving the visibility (awareness) by the above-described peripheral vision, that is, a color temperature of 4500 to 7000 [K] (preferably 5000 to 6000 [K]), The four coordinate values representing the prediction of the appearance of the four colors (red, green, blue, yellow) are coordinate values R (41.7 on the a ^* −b ^* coordinate system corresponding to the CIE1976L * a * b * space. , 20.9), G (-39.5, 14.3), B (8.8, -29.9), and Y (-10.4, 74.2).

  As the LED light source 11, for example, an LED light source in which a blue LED and a yellow phosphor are combined, for example, LEDs (T6, T7, T9) having correlated color temperatures shown in FIG. 11 can be used. In this case, for example, by adjusting the concentration and composition of the yellow phosphor, it is possible to configure an LED light source that satisfies the conditions for improving the above-described visibility (awareness). Alternatively, as the LED light source 11, it is also possible to use an LED light source that combines an ultraviolet LED and a white (three primary colors) phosphor, or an LED light source that combines a red, green, and blue three-color LED.

  Hereinafter, an example in which an LED light source (correlated color temperature: 6000 [K], luminous flux: 1100 [lm]) in which a blue LED and a yellow phosphor are combined is used as the LED light source 11 will be described.

  The lens body 12 includes an incident surface 12a on which light emitted from the LED light source 11 enters the lens, both side reflection surfaces 12b and 12c on which light from the LED light source 11 incident on the lens is internally reflected, and both side reflection surfaces. It is a solid lens body including an exit surface 12d from which light from the LED light source 11 reflected by 12b and 12c exits.

  As the lens body 12, for example, a lens body disclosed in JP 2009-238469 A, or a lens body having a configuration other than that described below can be used.

  The lens bodies 12 of the headlamp units 10A to 10D are arranged so that the inclination angle with respect to the reference axis AX0 extending in the vehicle front-rear direction increases from the vehicle center toward the outside (left side in FIG. 40). Hereinafter, the lens body 12 on the vehicle center side is the first lens body 12A, the lens body 12 adjacent to the outside is the second lens body 12B, the lens body 12 adjacent to the outside is the third lens body 12C, and the outside is adjacent to the outside. The lens body 12 that performs this operation is referred to as a fourth lens body 12D.

  The headlamp unit 10A is configured to collect light near the intersection of a horizontal line and a vertical line to form a hot zone light distribution pattern P1 including an elbow line.

  The first lens body 12A of the headlamp unit 10A is arranged so that the optical axis AX1 coincides with the reference axis AX0. The incident surface 12a, the both-side reflecting surfaces 12b and 12c, and the exit surface 12d of the first lens body 12A are provided with a horizontal line and a vertical line on a vertical screen on which light from the LED light source 11 incident on the lens is placed at a predetermined position in front. The hot zone light distribution pattern P1 (refer to FIG. 41) including the elbow line is collected near the intersection. The elbow line can be formed by using, for example, a light shielding film described in JP-A-2008-78086.

  The headlamp unit 10C is configured to form a diffused light distribution pattern P3 that is superimposed on the hot zone light distribution pattern P1 and diffused in the horizontal direction.

  The third lens body 12C of the headlamp unit 10C is arranged in a posture in which the optical axis AX3 is inclined further outward with respect to the reference axis AX0 (14 ° is illustrated in FIG. 40). The incident surface 12a, both side reflecting surfaces 12b and 12c, and the exit surface 12d of the third lens body 12C are arranged in a hot zone light distribution on a vertical screen in which light from the LED light source 11 incident on the lens is disposed at a predetermined position in front. A diffused light distribution pattern P3 (horizontally wide light distribution pattern extending from the right side of the right end of the middle diffusion light distribution pattern P2 to the left side of the left end, see FIG. 41) is formed by being superimposed on the pattern P1 and diffusing in the horizontal direction. It is configured as follows.

  The headlamp unit 10B is configured to form an intermediate diffusion light distribution pattern P2 having a horizontal diffusion degree smaller than that of the diffusion light distribution pattern P3 and superimposed on the respective light distribution patterns P1 and P3.

  The second lens body 12B of the headlamp unit 10B is arranged in a posture in which the optical axis AX2 is inclined outward with respect to the reference axis AX0 (7 ° is illustrated in FIG. 40). The incident surface 12a, both-side reflection surfaces 12b and 12c, and the exit surface 12d of the second lens body 12B are horizontally diffused on a vertical screen in which light from the LED light source 11 incident on the lens is disposed at a predetermined position in front. Is less than the diffused light distribution pattern P3 and the medium diffused light distribution pattern P2 superimposed on each of the light distribution patterns P1, P3 (wide in the horizontal direction extending from the vicinity of the right end of the hot zone light distribution pattern P1 to the left side of the left end). A light distribution pattern (see FIG. 41).

  The headlamp unit 10D is configured to form a large diffusion light distribution pattern P4 that has a greater degree of horizontal diffusion than the diffusion light distribution pattern P3 and is superimposed on each of the light distribution patterns P1 to P3.

  The fourth lens body 12D of the headlamp unit 10D is arranged in a posture in which the optical axis AX4 is inclined further outward with respect to the reference axis AX0 (21 ° is exemplified in FIG. 40). The entrance surface 12a, the reflecting surfaces 12b and 12c, and the exit surface 12d of the fourth lens body 12D are horizontally diffused on a vertical screen in which light from the LED light source 11 incident on the lens is disposed at a predetermined position in front. Is larger than the diffused light distribution pattern P3 and is superposed in the left-right direction extending from the vicinity of the right end of the diffused light distribution pattern P3 to the left side of the left end of the diffused light distribution pattern P3. The light distribution pattern P4 (see FIG. 41) is formed.

  The headlamp units 10A to 10B are arranged closer to the side of the vehicle and closer to the rear of the vehicle as the headlamp unit having a greater degree of horizontal diffusion (see FIG. 40). The vehicle is arranged so that the inclination angle toward the vehicle side surface with respect to the reference axis AX0 extending in the direction becomes large (see FIG. 40).

  According to this arrangement, even if the headlamp unit is arranged so as to wrap around the vehicle side from the front end of the vehicle in accordance with the vehicle design (see, for example, FIG. 40), the headlamp unit closer to the vehicle side (for example, the headlamp unit in FIG. 40). 10D) to form a diffused light distribution pattern (see, for example, P2 to P4 in FIG. 41) without being blocked by a headlamp unit (for example, see the headlamp unit 10C in FIG. 40) adjacent thereto. Is possible.

  In addition, the entire gradation-like light intensity decreases as the individual partial light distribution patterns including the hot zone light distribution pattern P1, the medium diffusion light distribution pattern P2, the diffusion light distribution pattern P3, and the large diffusion light distribution pattern P4 overlap. As a result, it is possible to construct a horizontal light distribution pattern (see FIGS. 41 and 46) optimized for the low beam light distribution pattern.

  In addition, since this ultra-wide light distribution is a gradation-shaped light distribution whose luminous intensity decreases as it goes outward (see FIGS. 41 and 46), while improving the left (and right) visibility in peripheral vision, It is possible to prevent or reduce glare for pedestrians. Note that a light source having a high ratio of radiant energy components is less likely to reduce the reaction time even when the luminance is low (see FIGS. 42 to 45).

[Comparative example]
Hereinafter, regarding the superiority of the headlamp 10 (correlated color temperature: 6000 [K], luminous flux: 1100 [lm] of the LED light source 11) of the present embodiment, the conventional LED headlamp (correlated color temperature: 4300) is used. [K], luminous flux: 540 [lm], hereinafter referred to as Conventional Example 1, and conventional HID headlamp (correlated color temperature: 4100 [K], luminous flux: 1100 [lm], hereinafter referred to as Conventional Example 2). A description will be given while comparing.

  FIG. 46 shows a light distribution pattern (luminance distribution) formed on the vertical screen by the headlamp 10 of the present embodiment. FIG. 47 is a light distribution pattern (luminance distribution) formed on the vertical screen by the headlamp of Conventional Example 1. FIG. 48 is a road surface light distribution pattern (isoluminance distribution) formed on the road by the headlamp 10 of the present embodiment. FIG. 49 is a road surface light distribution pattern (isoluminance distribution) formed on the road by the headlamp of Conventional Example 1. FIG. 50 shows a road surface light distribution pattern (isoluminance distribution) formed on the road by the headlamp of Conventional Example 2.

  46 to 50, according to the headlamp 10 of the present embodiment, the headlamps 10 arranged on the left side by the action of the lens bodies 12 </ b> A to 12 </ b> D are the headlamps of Conventional Example 1 and Conventional Example 2. Compared with the headlamps of Conventional Example 1 and Conventional Example 2, the ultra wide light distribution (see FIGS. 41 and 46) that extends significantly to the left side as compared with the headlamps 10 arranged on the right side is larger on the right side. It can be seen that it forms an extended ultra-wide light distribution).

  According to the headlamp 10 of the present embodiment, the LED light source 11 that satisfies the condition for improving the visibility (awareness) of the above-described peripheral vision is used, and the light from the LED light source 11 is excessive. Considering the formation of a wide light distribution (FIGS. 41 and 46), not only the front visibility is improved, but also the left side (and the right side) as viewed from the periphery as compared with the headlamps of Conventional Example 1 and Conventional Example 2. It can be seen that the visibility (awareness) of is greatly improved.

[Evaluation of ease of running]
In order to evaluate the ease of running of the vehicle equipped with the headlamp 10 of the present embodiment, the conventional example 1, and the conventional example 2, the following experiment was performed.

  Experimental environment: A vehicle equipped with the headlamp 10 of the present embodiment, the headlamps of the conventional example 1 and the conventional example 2 was used.

  Experimental procedure: Actually running on a vehicle equipped with the headlamp 10 of the present embodiment, the headlamps of the conventional examples 1 and 2, and the subjective evaluation scale (1: difficult to run, 2: difficult to run, 3: normal) (4: easy to run, 5: very easy to run). There are 18 subjects.

  FIG. 51 is a graph summarizing the evaluation results of ease of running. Referring to FIG. 51, it can be seen that the evaluation value of the headlamp 10 of the present embodiment is the highest. This is presumably due to the fact that the headlamp 10 of the present embodiment employs an ultra-wide light distribution that greatly extends to the left (and right).

  The headlamp 10 of this embodiment has an evaluation value as high as 0.8 as compared with the headlamp of Conventional Example 2 having substantially the same luminous flux. This is mainly because the color appearance under the illumination of the LED is closer to the color appearance under the illumination of the standard light source as compared with the HID (that is, the color can be reproduced more faithfully, see FIG. 37). This is thought to be due to the fact that an ultra-wide light distribution that extends greatly to the left (and right) is employed.

  The headlamp of Conventional Example 1 is one point lower in evaluation value than the headlamp of Conventional Example 2. This is probably because the headlamp of Conventional Example 1 has a lower luminous flux (540 [lm]) than the headlamp of Conventional Example 2 (light flux: 1100 [lm]), and therefore, the light distribution is less spread. .

[Evaluation of color visibility]
The following experiment was conducted in order to evaluate the visibility of the color when the vehicle equipped with the headlamp 10 of the present embodiment, the headlamps of the conventional example 1 and the conventional example 2 is running.

  Experimental environment: A vehicle equipped with the headlamp 10 of the present embodiment, the headlamps of the conventional example 1 and the conventional example 2 was used. On the road shoulder, red, green, blue, and yellow color marks C1 are arranged (see FIG. 52).

  Experimental procedure: Actually running on a vehicle equipped with the headlamp 10 of the present embodiment, the conventional example 1 and the conventional example 2, the subjective evaluation scale (1: invisible, 2: dull, 3: normal, 4: slightly vivid, 5: very vivid) was used to evaluate the visibility of the color mark C1. There are 18 subjects.

  FIG. 53 is a graph summarizing the evaluation results of the visibility of colors during travel. Referring to FIG. 53, it can be seen that the evaluation value of the headlamp 10 of the present embodiment is the highest for any of red, green, blue, and yellow. This is considered to be a result of color discrimination and vivid appearance due to the color temperature (6000 [K]) of the LED light source 11 used in the headlamp 10 of the present embodiment.

  Referring to FIG. 53, the headlamp 10 of the present embodiment greatly exceeds the evaluation value of the headlamps of the conventional example 1 and the conventional example 2, and can be said to be excellent in the perception of the sign. The red color meaning prohibition or regulation is 1.9 (70%) higher than the headlamp of Conventional Example 2 and 2.1 (84%) higher than the headlamp of Conventional Example 1. The yellow color meaning “attention” is 1.7 (59%) higher than the headlamp of Conventional Example 2 and 1.9 (77%) higher than the headlamp of Conventional Example 1. In view of this, according to the headlamp 10 of the present embodiment, it is possible not only to improve the visibility (awareness) by peripheral vision, but also to improve the visibility in terms of color perception. Can be estimated.

[Evaluation in the scene when turning right at the intersection]
The following experiment was performed to evaluate the visibility of color in a scene when turning right at the intersection of a vehicle equipped with the headlamp 10 of the present embodiment, the headlamps of the conventional example 1 and the conventional example 2.

  Experimental environment: A vehicle equipped with the headlamp 10 of the present embodiment, the conventional example 1 and the conventional example 2 was stopped before the intersection (see FIG. 54A). Color markers C2 (red, green, blue, and yellow) are arranged around the intersection (see FIGS. 54A and 54B).

  Experimental procedure: A subjective evaluation scale (1: invisible, 2: dull, 3: normal, 4: slightly vivid, 5: very vivid) was used to evaluate the visibility of color in the scene when turning right at the intersection. . There are 18 subjects.

  FIG. 55 is a graph summarizing the evaluation results of the visibility of colors in a scene when turning right at an intersection. Referring to FIG. 55, it can be seen that the evaluation value of the headlamp 10 of the present embodiment is highest for any of the pedestrian crossing front, the pedestrian crossing center, the pedestrian crossing back, and the shoulder front.

  The headlamp 10 of the present embodiment has a higher evaluation score of 3 in front of the pedestrian crossing than the headlamps of the conventional examples 1 and 2. This is mainly because the headlamp 10 arranged on the right side forms an ultra-wide light distribution that extends significantly to the right side as compared with the headlamps of the conventional example 1 and the conventional example 2, and the visibility by the peripheral vision described above It is considered that the LED light source 11 that satisfies the condition for improving (awareness) is used, and that light from the LED light source 11 forms an ultra-wide light distribution. This is considered to have a great effect on the reduction of the accident involving a right turn. Further, the headlamp 10 of the present embodiment is superior to the headlamps of the conventional example 1 and the conventional example 2 because the evaluation points at the center of the pedestrian crossing and the depth of the pedestrian crossing are 1.5 or more higher, which is advantageous in reducing accidents. I can guess.

As described above, according to the vehicle headlamp 10 of the present embodiment, the LED light source 11 that satisfies the condition for improving the visibility (awareness) by the above-described peripheral vision, that is, the color temperature is 4500. 7000 [K] (preferably 5000 to 6000 [K]) and four coordinate values representing the prediction of the appearance of four colors (red, green, blue, yellow) correspond to the CIE1976L * a * b * space A ^* -b ^* coordinate value on the coordinate system R (41.7,20.9), G (-39.5,14.3), B (8.8, -29.9), Y (-10.4,74.2) circle with radius 5 Since the LED light source 11 included in the range is used, it is possible to improve the visibility (awareness) of surrounding pedestrians and obstacles in the actual traffic environment (especially when turning right at the intersection).
Next, a modified example will be described.

[Outline of Headlamp Unit Arrangement (Modification 1 to Modification 3)]
In Modification 1 (the following Modification 2 and Modification 3 are also the same), the four headlamp units 10A to 10D shown in FIG. They are arranged adjacent to each other in the vehicle width direction (see, for example, FIGS. 64, 67, 69, and 71), and are formed by irradiation light from each of the plurality of headlamp units 10A to 10D (light emission ranges). The light distribution pattern for low beam is formed only by the partial distribution light patterns PLA to PLB (see FIG. 65A, etc.). Since the headlamp units 10A to 10D are arranged to form a continuous light emission range in the vertical direction (see, for example, FIGS. 64, 67, 69, and 71), the upper optical unit and the lower optical unit. It is possible to prevent a step in the illuminance cross section (illuminance unevenness) due to the difference in the mounting heights (see FIGS. 65, 68, and 70).

[Arrangement of Headlamp Unit (Modification 1)]
Hereinafter, modification 1 will be described in detail with reference to the drawings.

  FIG. 64 is a front view showing the arrangement (first modification) of the headlamp unit.

  The headlamp 20 of the first modification has a configuration in which the four optical units 10A to 10D shown in FIG. 40 are arranged in the horizontal direction (vehicle width direction) so that the respective light emission ranges have the same height when viewed from the front. is there.

  A rectangular range in FIG. 64 represents a range in which light is emitted from the optical units 10A to 10D (hereinafter referred to as a light emission range).

  FIG. 65 is a diagram showing a light distribution pattern formed on a virtual vertical screen disposed at a predetermined distance (for example, 25 m) in front of the lamp by the irradiation light from the headlamp 20 of the first modification. . From each of the optical units 10A to 10D, light having an emission angle equal to or smaller than the emission angle defined by the law is emitted as light distribution for at least a low beam with respect to the longitudinal direction of the lamp. For example, light of 0.57 degrees or less is emitted downward with respect to the horizontal direction, and in each of the optical units 10A to 10D, the emission angle of the light beam forming the upper end of the light beams emitted from each of the optical units 10A to 10D is 0.57 downward. It is set to be degrees.

  In the following description, for example, as shown in FIG. 65 (A), a light distribution pattern in which the upper light / dark boundary line is substantially parallel to the horizontal line is used for convenience, but the light distribution pattern formed in the present invention is It is not limited to this. That is, the present invention can be applied to a general low beam light distribution pattern as shown in FIG. 72 by using a light shielding film described in, for example, Japanese Patent Application Laid-Open No. 2008-78086.

  At this time, the light distribution patterns PLA to PLD corresponding to the respective optical units 10A to 10D are formed at positions lower than the horizontal line H indicating the height of the headlamp 20, and the light distribution patterns PLA to PLD are synthesized. Is obtained as a light distribution pattern of the entire headlamp 20.

  Here, as an example of the light distribution patterns PLA to PLD formed by the optical units 10A to 10D, only the light distribution pattern PLA obtained by the optical unit 10A is shown in FIG. As shown in the figure, the light distribution pattern PLA includes a boundary range PLAa in which a light / dark boundary line is formed as a boundary between a range where light is irradiated and a range where light is not irradiated at the upper edge, and light other than the boundary range PLAa. It is formed from the irradiated light distribution range PLAb.

  The boundary range PLAa corresponds to a range projected in a state where the light / dark boundary line is not clear (so-called blurred), and is emitted from the light emission range at the most upward angle among the light emitted from the optical unit 10A. The parallel light is irradiated and has the same height as the light emission range of the optical unit 10A in the vertical direction. The boundary range PLAa shows a distribution in which the illuminance value gradually increases from the upper end edge of the boundary range PLAa to the lower end edge of the boundary range PLAa.

  On the other hand, the light distribution range PLAb is a range in which the light distribution pattern (shape, size, illuminance) can be freely controlled by the design of the optical unit 10A.

  As for the light distribution patterns PLB, PLC, and PLD formed by the other optical units 10B to 10D, similarly to the light distribution pattern PLA, as shown in FIG. It is formed of boundary ranges PLBa, PLCa, PLDa having the same height as the direction height, and light distribution ranges PLBb, PLCb, PLDb in which the light distribution pattern can be freely controlled.

  In the case of the arrangement of the optical units 10A to 10D shown in FIG. 64, the heights of the light emission ranges of the optical units 10A to 10D are the same, and the upper end light beam emitted from each of the optical units 10A to 10D. Since the emission angles of the light distribution patterns PLA, PLB, PLC, and PLD coincide with each other, the boundary ranges PLAa, PLBa, PLCa, and PLDa are overlapped at the same position in the vertical direction. It is like that.

  The light distribution pattern of the entire headlamp 20 thus obtained shows an illuminance distribution as shown in the illuminance cross-sectional view of FIG. 65B on the V line indicating the center position of the left and right of the headlamp 20. According to this, there is no minimum value at which the illuminance value is lower than that of the upper and lower peripheral portions, and an ideal light distribution pattern in which illuminance unevenness (light distribution unevenness) does not occur is formed. That is, since the boundary ranges PLAa, PLBa, PLCa, and PLDa that are the blur ranges of the light and dark boundary lines of the light distribution patterns PLA, PLB, PLC, and PLD formed by the optical units 10A to 10D are superimposed, uneven illuminance is generated. It does not occur, and the blur range of the light / dark boundary line of the light distribution pattern of the headlamp 20 as a whole can be minimized.

  In addition, the light distribution range which each optical unit 10A-10D takes may differ from the above-mentioned case, and the light distribution pattern PLA, PLB, PLC, PLD formed by each optical unit 10A-10D is the said implementation. It may not be shown in the form. Further, the light distribution range of any one of the optical units may be an angular direction other than the front with respect to the horizontal direction.

  In the first modification, the headlamp 20 has four optical units 10A to 10D, and the light emission ranges of the optical units 10A to 10D have the same shape and size. Modification 1 includes each of the optical units so as to satisfy the following conditions (conditions of Modification 1), including a configuration in which the number of optical units is a plurality other than 4 and the light emission ranges of the optical units are not the same. The light emission range is arranged. That is, among the light emission ranges of a plurality (arbitrary number) of optical units arranged in the headlamp 20, the vertical light emission range within the vertical position range (height range) is arranged. The light emission range of another optical unit is arranged. For example, it can be considered that the upper end, the lower end, or the center position of the light emission range of each optical unit is the same height.

[Arrangement of Headlamp Unit (Modification 2)]
Next, Modification 2 will be described.

  FIG. 67 is a front view showing the arrangement (Modification 2) of the headlamp unit.

  In the headlamp 30 of the second modification, the four optical units 10A to 10D shown in FIG. 40 are different from each other in the height at which the respective light emission ranges are different in front view, that is, the leftmost (or rightmost) optical unit 10A. It is the structure which has arrange | positioned in the high position and arrange | positioned in the position lower than the optical unit of the left side (or right side) in order to the optical unit 10D of the right end (or left end).

  Further, the position of the lower end edge of the light emitting range of the optical unit 10A arranged at the highest position is arranged so that the height of the upper end edge of the light emitting range of the optical unit 10D arranged at the lowest position coincides. The light emission ranges of the optical units 10B and 10C are arranged so as to be within the range between the upper edge of the light emission range of the optical unit 10A and the lower edge of the light emission range of the optical unit 10D.

  FIG. 68 (A) is a diagram showing a light distribution pattern formed on a virtual vertical screen arranged at a predetermined distance (for example, 25 m) in front of the lamp by the light emitted from the headlamp 30. From each of the optical units 10A to 10D, light having an emission angle equal to or smaller than the emission angle defined by the law is emitted as light distribution for at least a low beam with respect to the longitudinal direction of the lamp. For example, light of 0.57 degrees or less is emitted downward with respect to the horizontal direction, and in each of the optical units 10A to 10D, the emission angle of the light beam forming the upper end of the light beams emitted from each of the optical units 10A to 10D is 0.57 downward. It is set to be degrees.

  At this time, light distribution patterns PLA, PLB, PLC, and PLD similar to the light distribution pattern shown in FIG. 65A indicate the height of the vehicular headlamp 300 corresponding to each of the optical units 10A to 10D. The light distribution patterns PLA, PLB, PLC, and PLD are also formed in a position lower than the horizontal line H, and the light emission ranges of the optical units 10A to 10D correspond to the height difference of the light emission ranges of the optical units 10A to 10D. Are formed at different heights by the difference in height.

  Further, the lower end edge of the boundary range PLAa of the light distribution pattern PLA formed by the optical unit 10A and the upper end edge of the boundary range PLDa of the light distribution pattern PLD formed by the optical unit 10D are formed at the same height. The boundary ranges PLBa and PLCa of the light distribution patterns PLB and PLC formed by the optical units 10B and 10C are formed within the range PLAa and the boundary range PLDa.

  The light distribution pattern of the entire headlamp 30 obtained in this manner shows an illuminance distribution as shown in the illuminance cross-sectional view of FIG. 68B on the V line indicating the left-right center position of the headlamp 30. According to this, there is no minimum value at which the illuminance value is lower than the upper and lower peripheral portions, and a light distribution pattern in which illuminance unevenness (light distribution unevenness) does not occur is formed.

  In addition, the light distribution range which each optical unit 10A-10D takes may differ from the above-mentioned case, and the light distribution pattern PLA, PLB, PLC, PLD formed by each optical unit 10A-10D is the said implementation. It may not be shown in the form. Further, the light distribution range of any one of the optical units may be an angular direction other than the front with respect to the horizontal direction.

  In the second modification, the headlamp 30 has four optical units 10A to 10D, and the light emission ranges of the optical units 10A to 10D have the same shape and size. In the second modification including the case where the number of optical units is a plurality other than four or the light emission ranges of the respective optical units are not the same, the second modification satisfies the following conditions (conditions of the second modification). The light emission range is arranged. That is, among the light emission ranges of a plurality (arbitrary number) of optical units arranged in the headlamp 30, the light emission range (uppermost light emission range) arranged at the highest position and the lower end at the lowest position. The light emission range (lowermost light emission range) is arranged so as to form a continuous range in the vertical direction, and the light emission ranges of the other optical units are arranged in the continuous range. Of these conditions, a range excluding the range satisfying the condition of Modification 1 is the condition of Modification 2. In addition, when the position of the lower end of the uppermost light emission range is lower than the position of the upper end of the lowermost light emission range, or when those positions coincide, the light emission ranges are in the vertical direction. It is assumed that a continuous range is formed.

  When the light emission ranges of a plurality of optical units are arranged so as to satisfy the conditions of Modification 2, the blur range of the light / dark boundary line in the light distribution pattern of the entire headlamp 30 is larger than that of Modification 1, but each optical Since the range of blurring of the light distribution pattern by the unit is overlaid, uneven illuminance does not occur.

[Arrangement of Headlamp Unit (Modification 3)]
Next, Modification 3 will be described.

  FIG. 69 is a front view showing the arrangement (Modification 3) of the headlamp unit.

  The headlamp 40 of the third modification is different from the four optical units 10A to 10D shown in FIG. 40 in that the light emission ranges are different from each other in the front view, that is, the leftmost (or rightmost) optical unit 10A is the most. It is the structure which has arrange | positioned in the high position and arrange | positioned in the position lower than the optical unit of the left side (or right side) in order to the optical unit 10D of the right end (or left end).

  On the other hand, the headlamp 40 is different from the headlamp 30 of FIG. 67 in terms of the arrangement conditions of the optical units 10A to 10D, and the light emission range of the optical unit 10A arranged at the highest position and the optical arrangement arranged at the lowest position. The light emission range of the unit 10D is not continuous in the vertical direction.

  However, the light emission ranges of the optical units 10A to 10D are arranged so as to be continuous in the vertical direction, and the height of the lower edge of the light emission range of the optical unit 10A matches the height of the upper edge of the light emission range of the optical unit 10B. The lower edge of the light emission range of the optical unit 10B matches the height of the upper edge of the light emission range of the optical unit 10C, and the height of the lower edge of the light emission range of the optical unit 10C and the height of the upper edge of the light emission range of the optical unit 10D. Match.

  FIG. 70A is a diagram showing a light distribution pattern formed on a virtual vertical screen arranged at a predetermined distance (for example, 25 m) in front of the lamp by the light emitted from the headlamp 40. From each of the optical units 10A to 10D of the headlamp 40, light having an emission angle equal to or smaller than the emission angle defined by the law is emitted as light distribution for at least a low beam in the vertical direction of the lamp. For example, light of 0.57 degrees or less is emitted downward with respect to the horizontal direction, and in each of the optical units 10A to 10D, the emission angles of the light rays forming the upper end among the light rays emitted from each of the optical units 10A to 10D are all downward 0.57. It is set to be degrees.

  At this time, corresponding to each of the optical units 10A to 10D, a light distribution pattern PLA, PLB, PLC, PLD similar to the light distribution pattern shown in FIG. 65A is a horizontal line H indicating the height of the headlamp 40. The light distribution patterns PLA, PLB, PLC, and PLD are also heights of the light emission ranges of the optical units 10A to 10D corresponding to the difference in height of the light emission ranges of the optical units 10A to 10D. Are formed at different heights.

  Further, the lower end edge of the boundary range PLAa of the light distribution pattern PLA and the upper end edge of the boundary range PLBa of the light distribution pattern PLB are formed at the same height, and the lower end edge of the boundary range PLBa of the light distribution pattern PLB and the light distribution The upper edge of the boundary range PLCa of the pattern PLC is formed at the same height, and the lower edge of the boundary range PLCa of the light distribution pattern PLC and the upper edge of the boundary range PLDa of the light distribution pattern PLD are formed at the same height. The

  The light distribution pattern of the entire headlamp 40 thus obtained shows an illuminance distribution as shown in the illuminance cross-sectional view of FIG. 70B on the V line indicating the left-right center position of the headlamp 40. According to this, although the illuminance value swells, there is no local minimum value at which the illuminance value is lower than the upper and lower peripheral portions, and a light distribution pattern in which illuminance unevenness (light distribution unevenness) does not occur is formed. .

  In addition, the light distribution range which each optical unit 10A-10D takes may differ from the above-mentioned case, and the light distribution pattern PLA, PLB, PLC, PLD formed by each optical unit 10A-10D is the said implementation. It may not be shown in the form. Further, the light distribution range of any one of the optical units may be an angular direction other than the front with respect to the horizontal direction.

  In the third modification, the headlamp 40 has four optical units 10A to 10D, and the light emission ranges of the optical units 10A to 10D have the same shape and size. Modification 3 includes the case where the number of optical units is a plurality other than 4 or the light emission range of each optical unit is not the same, and Modification 3 satisfies the following conditions (conditions of Modification 3). The light emission range is arranged. That is, the light emission ranges of a plurality (arbitrary number) of optical units arranged in the headlamp 40 are arranged so as to form one range that is continuous in the vertical direction. However, a range excluding a range satisfying the condition of Modification 2 among these conditions is the condition of Modification 3. For example, as shown in the headlamp 41 of FIG. 71, even if the light emitting ranges of the four optical units 10A to 10D have different widths in the vertical direction, the light emitting ranges are formed as one continuous range in the vertical direction. By arranging in such a manner, unevenness in illuminance can be prevented.

  When the light emission ranges of a plurality of optical units are arranged so as to satisfy the condition of the third modification, the light / dark boundary line in the light distribution pattern of the entire headlamp 40 (or headlamp 41) as compared with the first and second modifications. Although the range of the blur is increased, the blur range of the light distribution pattern by each optical unit is not separated in the vertical direction, so that illuminance unevenness does not occur.

  As described above, the configuration of the vehicle headlamp described in the first to third modifications can be applied as the configuration of the headlamp of any type of vehicle such as a two-wheeled vehicle, a four-wheeled vehicle, and a train. The present invention is not limited to the headlamp, and can be applied to a configuration of an arbitrary type of vehicle lamp such as a fog lamp.

  Moreover, in the said modification 1-modification 3, the upper end of the light distribution pattern (light distribution pattern which each optical unit forms) among the light rays radiate | emitted from each of the some optical unit arrange | positioned as a vehicle lamp is formed. All the light rays (the most upward light rays) to be emitted have the same emission angle, but this is not restrictive, and the light rays that form the upper end of the light distribution pattern among the light rays emitted from each optical unit are at an arbitrary distance. For example, the light distribution is performed for each optical unit based on the height from the road surface where the light emission range of each optical unit is arranged so that the emission angle irradiates the road surface located at a predetermined distance of about 50 to 80 m ahead of the lamp. You may make it set the emission angle of the light beam which forms the upper end of a pattern. That is, as shown in FIG. 73, the height at which the light emission range of the optical unit having the highest contribution to the upper end of the light distribution pattern is arranged is a (m), and the upper end of the light distribution pattern is formed in the optical unit. When the distance to the position where the light beam illuminates the road surface is I (m) and the emission angle of the light beam is m, the upper end of the light distribution pattern is formed in the optical unit having the height b (m) where the light emission range is arranged. The output angle x of the light beam is set to be an angle (downward angle with respect to the horizontal direction) obtained by the following formula, x = m−arctan {(ab) / I}, and is formed by each optical unit. The range of blurring of the light / dark boundary line of the light distribution pattern may overlap on the road surface of the distance I in front of the lamp.

  As described above, according to the first to third modifications, the four headlamp units 10A to 10D shown in FIG. 40 are not carved in the vertical direction in the front view but in the light emission range instead of the upper and lower stages. Arranged in a state adjacent to each other in the width direction (see, for example, FIGS. 64, 66, 68, and 70), and individual portions formed by irradiation light from each of the plurality of headlamp units 10 </ b> A to 10 </ b> D (light emission ranges). In this configuration, the light distribution pattern for low beam is formed only by the distribution light patterns P1 to P4. Since the headlamp units 10A to 10D are arranged to form a continuous light emission range in the vertical direction (see FIGS. 64, 66, 68, and 70), the upper optical unit and the lower optical unit described above. It is possible to prevent a difference in illuminance cross section (illuminance unevenness) due to a difference in the mounting height of the illuminant (see FIGS. 65, 67, 69, and 71).

  Note that the headlamp units to which the first to third modifications can be applied are not limited to the four headlamp units 10A to 10D shown in FIG. For example, the headlamp units 50 </ b> A to 50 </ b> D, which will be described later, and headlamp units having other configurations can be similarly applied.

  Moreover, although the modification 1-the modification 3 demonstrated the example using four headlamp units 10A-10D, this invention is not limited to this. For example, it is possible to use two, three, five or more headlamp units.

[Outline of Headlamp Unit (Modification 4 to Modification 6)]
In this modified example 4 (same as modified examples 5 and 6 below), as shown in FIG. 76 and the like, a headlamp unit is used to prevent or reduce rainbow-like coloring in the vicinity of the light / dark boundary line caused by chromatic aberration. 50A-50D was constructed.

  The headlamp units 50 </ b> A to 50 </ b> D are headlamp units configured to irradiate light used for forming a partial light distribution pattern that forms a low-beam light distribution pattern in a predetermined white range.

  The head lamp units 50 </ b> A to 50 </ b> D include an LED light source 51, a lens body 52 disposed in front of the LED light source 51, and the like as a common configuration.

The LED light source 51 is an LED light source that satisfies the conditions for improving the visibility (awareness) by the above-described peripheral vision, that is, a color temperature of 4500 to 7000 [K] (preferably 5000 to 6000 [K]), The four coordinate values representing the prediction of the appearance of the four colors (red, green, blue, yellow) are coordinate values R (41.7 on the a ^* −b ^* coordinate system corresponding to the CIE1976L * a * b * space. , 20.9), G (-39.5, 14.3), B (8.8, -29.9), and Y (-10.4, 74.2).

  As the LED light source 51, for example, an LED light source in which a blue LED and a yellow phosphor are combined, for example, LEDs (T6, T7, T9) having correlated color temperatures shown in FIG. 11 can be used. In this case, for example, by adjusting the concentration and composition of the yellow phosphor, it is possible to configure an LED light source that satisfies the conditions for improving the above-described visibility (awareness). Alternatively, as the LED light source 11, it is also possible to use an LED light source that combines an ultraviolet LED and a white (three primary colors) phosphor, or an LED light source that combines a red, green, and blue three-color LED.

  As shown in FIG. 76, the lens body 52 includes a light incident surface 52a on which light emitted from the LED light source 51 enters the lens, a light exit surface 52b, and light incident on the inside of the lens from the light incident surface 52a. A solid lens body that includes a reflecting surface 52c that is configured to reflect, and the reflected light is emitted from the emitting surface 52b to form a partially distributed light pattern PA or the like (see FIG. 77) having a bright / dark boundary line CL. is there.

  The reflection surface 52c internally reflects the light X1 (G1) of the reference wavelength that is emitted from one side 51B of the LED light source 51 corresponding to the light / dark boundary line CL, enters the light incident surface 52a perpendicularly, and enters the lens without being refracted. Then, the reflected light is emitted from the emission surface 52b to form the light / dark boundary line CL, and the LED light source 51 corresponding to the light / dark boundary line CL and the first light reflective area (corresponding to T1 in FIG. 76). Light R2 emitted from one side 51B is incident on the light incident surface 52a at an angle other than perpendicular, is refracted according to the incident angle, and is incident on the inside of the lens, and is internally reflected, and the reflected light is emitted from the surface. A second reflection region 52c (a region between the intersection of the light R2 and the reflection surface 52c and T1 in FIG. 76) configured to be emitted from 52b and distributed below the light-dark boundary line CL, and a light-dark boundary Compatible with line CL The light B3 emitted from one side 51B of the LED light source 51 is incident on the light incident surface 52a at an angle other than perpendicular, is refracted according to the incident angle, and is incident on the inside of the lens, and is internally reflected. A third reflection region 51c2 configured such that the reflected light is emitted from the emission surface 52b and distributed below the bright / dark boundary line CL (in FIG. 76, between the intersection of the light R3 and the reflection surface 52c and T1). Area).

  According to this configuration, light from the LED light source 51 that causes rainbow-like coloring in the vicinity of the light-dark boundary line CL that is refracted according to the incident angle to the light incident surface 52a and enters the inside of the lens (than the reference wavelength). The short-wavelength light R2 and the long-wavelength light B3) are distributed below the light-dark boundary line CL by the action of the second reflective region 52c1 and the third reflective region 52c2, so that the rainbow near the light-dark boundary line caused by chromatic aberration It becomes possible to prevent or reduce the coloring of the shape.

  The second reflection region 52c1 internally reflects the light R2 having a wavelength longer than the reference wavelength incident on the inside of the lens, and the reflected light is emitted from the emission surface 52b to be distributed on the light / dark boundary line CL or in the partial distribution light pattern PA. The third reflection region 52c2 internally reflects the light B3 having a wavelength shorter than the reference wavelength incident on the inside of the lens, and the reflected light is emitted from the emission surface 52c2 on the light / dark boundary line CL or It is desirable that the light is distributed within the partial distribution light pattern PA.

  In this way, light that causes refraction in accordance with the incident angle to the light incident surface and enters the lens and causes rainbow-like coloring near the light-dark boundary line CL (light R2 having a wavelength shorter than the reference wavelength and Since the light B3) having a long wavelength is distributed on the light / dark boundary line CL or in the partial light distribution pattern PA by the action of the second reflection region 52c1 and the third reflection region 52c2, color unevenness in the partial light distribution pattern PA. Can be prevented or reduced.

  Further, the reflection surface 52c is formed so that the light emitted from the end portion 51B of the LED light source 51 is emitted from the emission surface 52b in a direction extending inside the light / dark boundary line CL and the partial distribution light pattern PA. Thus, the light emitted from the end portion 51B of the LED light source 51 is superimposed on the light emitted from a point on the light emission surface other than the end portion 51B on the light emission surface 51A of the LED light source 51. Is desirable.

In this way, the light emitted from the end portion 51B of the LED light source 51 is mixed with the light emitted from a point other than the end portion 51B of the LED light source 51. Therefore, color unevenness at the end portion 51B of the LED light source 51 is caused. It is possible to prevent or reduce the resulting color unevenness of the partial distribution light pattern PA. [Headlamp unit (Modification 4)]
Hereinafter, Modification 4 will be described in detail.

  FIG. 75 is a front view of the headlamp 50. The headlamp 50 in the figure is applied to a headlamp for passing light (low beam) in, for example, an automobile or a motorcycle, and includes one LED light source 51 and A plurality of (four) light source units 50 </ b> A to 50 </ b> D each including a combination of one lens body 52 (light guide) are provided. These light source units 50A to 50D have the same basic configuration but different light distribution patterns. By superimposing the illumination light emitted from the emission surfaces of the light source units 50A to 50D, As a light distribution pattern, illumination light having a light distribution pattern of passing light (low beam) is irradiated. In the headlamp 50 shown in the figure, the light source units 50A to 50D are arranged in a line in the horizontal direction. However, the arrangement of the light source units 50A to 50D is not limited to this, and the number of light source units is four. The number is not limited to one, but may be one or more than four.

  FIG. 76 is a vertical sectional view showing the configuration of one light source unit 50A of the headlamp 50. As shown in FIG. A light source unit 50A shown in the figure includes a lens body 52 (light guide) formed of a polycarbonate material that is a transparent resin having high heat resistance, an LED light source 51, and the like.

  The lens body 52 is disposed, for example, on the bottom surface including the incident surface 52a, the reflection surface 52c disposed on the vehicle rear side (lamp rear side), the emission surface 52b disposed on the vehicle front side, and the vehicle upper side. And a three-dimensional shape surrounded by two side surfaces (not shown) arranged on both sides of the vehicle.

  The incident surface 52a is a light incident surface on which the light emitted from the LED light source 51 enters the lens body 52, and is formed by a plane inclined obliquely with respect to the vehicle front-rear direction. The other surface constituting the bottom surface is a horizontal plane.

  The reflection surface 52c is a surface that reflects light emitted from the LED light source 51 and incident into the lens body 52 by the incident surface 52a in a predetermined direction, and is formed based on, for example, the shape of a rotating paraboloid system. Has been. The reflection surface 52c may be formed by total reflection on the inner surface, or may be reflected by a mirror surface by forming a metal reflection film or the like on the outer surface in a portion where the reflection is not totally reflected.

  The emission surface 52b is a surface from which the reflected light from the reflection surface 52c is emitted, and is formed by a vertical plane orthogonal to the vehicle longitudinal direction in this embodiment.

  The LED light source 51 is, for example, a light source that emits white light in which one or a plurality of LED chips are packaged, and a planar light emitting surface 50A that emits light is disposed substantially upward in the vertical direction. For example, an InGaN-based LED chip that emits blue light is used as the LED chip, and the LED chip 200 mounted on the circuit board 202 as shown in FIG. Can do. As the wavelength conversion material layer 204, for example, a known YAG phosphor dispersed in a silicone resin is used. As a result, white light is emitted by a color mixture of blue from the LED chip and yellow (light including red and green components) wavelength-converted into a YAG phosphor. Note that the light emission surface 51A is not limited to a planar shape, and may have a convex shape.

  In FIG. 84, three InGaN LED chips arranged in a straight line with a predetermined gap are used, and the periphery of the LED chip including the gap between the LED chips is shown in FIGS. 84 (B) and (C). As shown, the wavelength conversion material layer 204 is covered with a rectangle so that the upper surface is a flat surface. In order to form the wavelength conversion material layer in a planar shape on the upper surface, for example, it can be formed by applying a liquid translucent resin material in which the wavelength conversion material is dispersed by applying a printing method or the like and then curing it.

  The headlamp 50 including the light source unit 50A configured as described above and the light source units 50B to 50D configured in the same manner is illustrated by superimposing the illumination light emitted from the light source units 50A to 50D. A light distribution pattern for passing light as shown in 77 is formed. The headlamp 50 according to the present embodiment is a headlamp installed in a vehicle for left traveling. When the headlamp 50 is installed in a vehicle for right traveling, the components of the vehicle lamp 50 are reversed left and right. The light distribution pattern is also a horizontally reversed pattern.

  In the figure, an H line indicating a horizontal angle (indicating a horizontal height of the headlamp 50) and a vertical angle with respect to the direction directly in front of the headlamp 50 (the direction of the reference axis) ( The V line is shown (showing the left and right center position).

  As shown in the drawing, the light distribution pattern P of the headlamp 50 has a light distribution region in a wide angle range in the left-right direction within an angle range downward from the H line, and about 25 on the right side of the V line. Illumination light is irradiated to an angle range of about 65 degrees on the left side. At the upper edge of the light distribution pattern P, a light / dark boundary line (cut-off line) CL indicating a light / dark boundary between a bright region irradiated with light and a dark region not irradiated with light is formed in the horizontal direction. The line CL is formed in the vicinity of the H line (for example, downward 0.57 degrees).

  The light distribution pattern P is formed by overlapping light distribution patterns (light distribution regions) PA to PD for the respective light source units 50A to 50D. For example, the light source unit 50A has an HV center point (H = V = 0 degree) A light distribution pattern PA that brightly illuminates a narrow area near is formed, the light source units 50B and 50C form medium light distribution patterns PB and PC including the light distribution pattern PA, and the light source unit 50D The large light distribution pattern PD including the light distribution patterns PA, PB, and PC is formed. However, the light distribution patterns PA to PD formed by the light source units 50A to 50D are not limited to the above case, and the light distribution patterns PA to PD of the light source units 50A to 50D are not limited to the above case. . Further, the overall light distribution pattern P as the headlamp 50 is not limited to that shown in FIG. 77, and the number of light source units is not limited to four, but may be three, two, or five or more. .

  By the way, each of the light source units 50A to 50D is optically designed by the same method. For example, when the optical design of the light source unit 50A is performed, first, light is emitted from the light emission surface 51A of the LED light source 51 in each direction. The positional relationship between the LED light source 51 and the lens body 52 and the target of the white light so that the light distribution pattern PA shown in FIG. 77 is formed with respect to the white light (light having a wavelength in the visible light region). The irradiation direction (target emission direction when emitting white light from the lens body 52) is determined. Then, the shapes of the entrance surface 52a, the reflection surface 52c, and the exit surface 52b of the lens body 52 are set so that each white light beam emitted from the light emitting surface 51A in each direction becomes the target exit direction. In the present embodiment, the light emitting surface 51A of the rotating paraboloid type system is formed such that the light emitting point 51B which is the rearmost end in the vehicle front-rear direction is enlarged and projected onto the light / dark boundary line CL to form a cut-off line. The reflection surface 52c is set. If the last end is the light / dark boundary line CL, the light emitted from the foremost end of the light emitting surface 51A is directed downward from the light / dark boundary line CL, and glare light upward from the H line is not generated. .

  When performing such an optical design, a refractive index corresponding to a material of the lens body 52 is used as a refraction angle with respect to an incident angle of the white light incident surface 52a or the exit surface 52b, and the refractive index depends on the wavelength of light. Are different from each other, a refractive index with respect to a specific reference wavelength (hereinafter referred to as a reference refractive index) is approximately used as a constant refractive index in the entire wavelength range of white light (visible light region). In this embodiment, a green wavelength, which is a substantially central wavelength in the wavelength region of white light, is set as a reference wavelength, and a refractive index of the green wavelength is set as a reference refractive index. It is assumed that optical design such as the shapes of the incident surface 52a, the reflecting surface 52c, and the exit surface 52b of the lens body 52 is performed so that the light distribution pattern PA shown in FIG. 77 is obtained.

  On the other hand, when the lens body 52 is formed of a transparent resin material as in Modification 4, the difference in refractive index for each wavelength of light is greater than that of a glass lens that is an inorganic material. In particular, when formed of a polycarbonate material with excellent transparency, heat resistance and weather resistance, the polycarbonate material has a large difference in refractive index for each wavelength of light and a large chromatic dispersion. If the optical design is performed so that the light distribution pattern PA of FIG. 77 is obtained, an unintended color-separated illumination region (color blur region) due to color dispersion above the angular position of the light / dark boundary line CL of the light distribution pattern PA. ) Is formed. When the same optical design is performed for the light source units 50B to 50D, an unintended color-separated illumination area Q is formed on the entire upper side of the light / dark boundary line CL of the light distribution pattern P as the headlamp 50 as shown in FIG. . Here, chromatic dispersion refers to dispersion of light, and refers to a phenomenon in which the refractive index varies depending on the wavelength when light is incident on a lens or the like.

  That is, the lens body 52 basically forms a light distribution pattern PA as shown in FIG. 77 by enlarging and projecting the light emission surface 51A of the LED light source 51. Therefore, as described above, assuming a constant reference refractive index for the entire wavelength range of white light, the optical design is performed so that the light distribution pattern PA of FIG. 77 is obtained without considering the chromatic dispersion of the lens body 52. In this case, the positional relationship between the light emitting surface 51 </ b> A of the LED light source 51 and the lens body 52 is determined so that the light emitting point 51 </ b> B that is the rearmost end in the vehicle longitudinal direction of the light emitting surface 51 </ b> A becomes the focal point of the entire lens body 52. Is done. The focal point of the entire lens body 52 refers to a focal position adjusted in consideration of the influence of refraction by the incident surface 52a with respect to the focal position of the reflecting surface 52c of the paraboloidal system. At this time, the white light beam emitted in each direction from the light emission point 51B is irradiated as a light beam substantially parallel to the angular direction of the light / dark boundary line CL which is the design target. The white light beam emitted from each point of the light emission surface 51A on the vehicle front side from the light emission point 51B is designed to illuminate an angular range below the design target light / dark boundary line CL.

  On the other hand, in consideration of actual chromatic dispersion generated in the lens body 52, the white light beam emitted from the light emission point 51B passes through an optical path (non-refractive optical path) that is not refracted by both the incident surface 52a and the output surface 52b. What is to be irradiated is irradiated in the angular direction of the design target light / dark boundary line CL, but for the light passing through the light path (refracted light path) refracted at the entrance surface 52a or the exit surface 52b, the green color used as the reference refractive index is used. Light with a wavelength other than the wavelength (green light), that is, red or blue light with a wavelength longer or shorter than the green wavelength, the actual refractive index of those wavelengths is different from the reference refractive index. Therefore, the lens body 10 is separated in a direction different from that of the green light ray on the surface where the refraction occurs. As a result, a part of red and blue light rays are irradiated in an upward angle direction with respect to the light / dark boundary line CL, which is the design target, causing color bleeding above the light / dark boundary line CL, and above the light / dark boundary line CL. An unintended illumination region Q as shown in FIG. 78 is formed. The illumination area Q may disturb the chromaticity uniformity of the light distribution pattern (cause color unevenness) and may cause light upward from the H line.

  Therefore, in the fourth modification, as described above, the basic configuration of the light source unit 50A designed without considering chromatic dispersion assuming a constant reference refractive index for the entire wavelength range of white light, that is, With respect to the positional relationship between the LED light source 51 and the lens body 52, the configuration of the lens body 52, etc. (shapes of the incident surface 52a, the reflective surface 52c, and the exit surface 52b, etc.), the light emission point of the light emission surface 51A is as follows. In consideration of chromatic dispersion (difference in refractive index for each wavelength) with respect to white light emitted from 51B, the incident surface of the lens body 52 prevents color blurring (unintended illumination region Q) from occurring above the light-dark boundary line CL. Adjustments (corrections) are made to the shapes of 52a, reflecting surface 52c, and emitting surface 52b.

  The polycarbonate material has a characteristic that the refractive index decreases as the wavelength increases in the range of about 380 to 780 nm, which is the wavelength region of white light (the wavelength region of visible light). The refractive index is 1.6115 for 435.8 nm, the refractive index is 1.5855 for the green wavelength of 546.1 nm, and the refractive index is 1.576 for the blue wavelength of 706.5 nm. At this time, when designing the basic shapes of the entrance surface 52a, the reflection surface 52c, and the exit surface 52b of the lens body 52, for example, the wavelength of the green light used as the light of the reference wavelength is the above 546.1 nm. The reference refractive index is set to 1.5855. In addition, among the wavelength ranges of light that should be considered for the problem of chromatic dispersion of the lens body 52, the longest wavelength is the wavelength of red light such as the above-described wavelength of 706.5 nm, and the shortest wavelength is For example, the basic shape of the entrance surface 52a, the reflection surface 52c, and the exit surface 52b of the lens body 52 is adjusted as the wavelength of blue light such as the above-described wavelength of 435.8 nm. The light described by designating colors such as red light and blue light indicates light of these wavelengths. However, the value of each wavelength specifically shown is appropriately changed.

  In the fourth modification, the basic shapes of the incident surface 52a, the reflecting surface 52c, and the emitting surface 52b of the lens body 52 are adjusted only by adjusting the reflecting surface 52c. The shape of the emission surface 52b is fixed to the surface shape (plane) when designed so as to obtain the light distribution pattern PA of FIG. 77 assuming the reference refractive index, and the reflection surface 52c is, for example, basic. The rotation paraboloid obtained as a simple shape is adjusted.

  Furthermore, the emission surface 52b of the lens body 52 of the fourth modification is formed as a substantially vertical plane as described above. Since the light reflected from the reflecting surface 52c in the vicinity of the light-dark boundary line CL is irradiated substantially horizontally, the refraction by the emitting surface 52b is small and the degree of chromatic dispersion is also small. Therefore, for the sake of simplicity, it is assumed that color dispersion and color separation are not caused by the emission surface 52b, and the direction of the light beam emitted from the emission surface 52b is equal to the direction of the light beam reflected by the reflection surface 52c. And

  Hereinafter, the shape adjustment of the lens body 52 will be described. The lens body 52 of FIG. 76 takes into account chromatic dispersion due to the difference in refractive index for each wavelength so that color blur (unintended illumination region Q) does not occur above the light / dark boundary line CL, and the reflecting surface 52c of the lens body 52 is considered. The shape is adjusted (corrected). In the figure, among the white light rays emitted from the light emission point 51B at the rearmost end of the LED light source 51, the white light ray X1 incident perpendicularly to the incident surface 52a (incidence angle 0 degree), and the vehicle from the white light ray X1. The solid line represents the optical path at the basic refractive index of the white light rays X2 and X3 obliquely incident on the incident surface 52a on the front side and the vehicle rear side (the optical path when the refractive index is constant over the entire wavelength range of the white light rays). It is illustrated by. As shown in the figure, each white light beam X1, X2, X3 emitted from the light emission point 51B of the LED light source 51 enters the lens body 52 from the incident surface 52a and is reflected by the reflecting surface 52c. The lens body 52 is irradiated from the exit surface 52b. In FIG. 76, assuming a constant reference refractive index for the entire wavelength range of white light rays, the optical paths corresponding to the white light rays X1, X2 and X3 in the case where chromatic dispersion is not taken into consideration are shown as the optical paths CLD1, CLD2 and CLD3. It is described as. CLD1 has the same optical path as X1, and CLD2 and CLD3 irradiate light parallel to CLD1 to the outside from the exit surface 52b. Such optical paths CLD1, CLD2, and CLD3 have a light emitting point 51B as a reflecting surface 52c (strictly, a position slightly obliquely lower left in the drawing from the light emitting point 51B in consideration of refraction by the incident surface 52a). It can be obtained by using a rotating paraboloid reflecting surface as a focal point. This shape is a basic shape. The optical paths CLD1, CLD2, and CLD3 indicated by the alternate long and short dash lines indicate the optical paths for emitting the white light rays X1, X2, and X3 from the emission surface 52b in the angular direction of the design target bright / dark boundary line CL, as described above. Since light rays in the vicinity of the light / dark boundary line CL are not refracted at the exit surface 52b, their optical paths CLD1, CLD2, and CLD3 are shown as straight lines from the position of the reflective surface 52c to the outside of the lens body 52 via the exit surface 52b. .

  On the other hand, in the lens body 52 of the fourth modification, the shape of the reflection surface 52c is set in consideration of chromatic dispersion, and the light enters the incidence surface 52a perpendicularly, and enters and exits the incidence surface 52a of the lens body 52. For the white light ray X1 in which refraction does not occur on the surface 52b, the target irradiation direction is set to the angular direction of the light / dark boundary line CL of the design target without any change as described above, and at the position T1 of the reflection surface 52c as shown in FIG. The shape (position and inclination) of the reflecting surface 52c at the position T1 matches the basic shape so that the incident white light beam X1 is reflected in the angular direction of the light / dark boundary line CL along the optical path CLD1. . In addition, the angle of the incident surface 52c is set so that the position T1 of the reflecting surface 52c where the white light beam X1 that does not cause refraction at the incident surface 52a is reflected is approximately the center of the vertical range of the reflecting surface 52c. Yes. As a result, the incident angle (refraction angle) of all light rays reflected by the reflecting surface 52c on the incident surface 52a is considered to be as small as possible, and the occurrence of chromatic dispersion itself is reduced. That is, the position T1 is a reflection part of a non-refractive optical path where refraction does not occur on the incident surface 52a, and coincides with the basic shape described above.

  On the other hand, with respect to white light rays (white light rays X2 and X3) that are incident on the incident surface 52a on the vehicle front side or vehicle rear side with respect to the white light beam X1 and are refracted on the incident surface 52a, color dispersion (color separation) generated by the refraction. ), The target irradiation direction is set to an angular direction downward from the design target light / dark boundary line CL, and a constant reference refractive index is assumed for the entire wavelength range of white light as shown in FIG. In this case, the white light rays X2 and X3 (that is, green light rays) incident on the positions T2 and T3 above and below the position T1 of the reflecting surface 52c are from the angular direction of the light / dark boundary line CL (optical paths CLD2 and CLD3). Also, the shape of the reflecting surface 52c is designed so as to be irradiated (reflected) in the downward angle direction.

  As a method of designing the reflecting surface 52c of the fourth modification by correcting the reflecting surface of the basic shape, for example, a position T1 where no correction is applied to the reflecting surface of the basic shape is used as a reference point. Assume that points on the reflecting surface are set as correction points in order above the reference point. Then, at a certain correction point, the inclination of the reflecting surface 52c is corrected so as to reflect the white light incident on the correction point in the corrected target irradiation direction, and the correction amount of the inclination is corrected. By applying rotation to the entire reflecting surface above the correction point, the position and inclination of each point on the entire reflecting surface above the correction point are corrected without changing the overall shape. Thereafter, a new correction point is set on the corrected reflection surface, and the same operation is repeated. A method of repeating the same operation on the reflective surface below the position T1 can be considered. However, the method of designing the reflection surface 52c of the fourth modification is not limited to this.

  Specifically, when the shape of the reflecting surface 52c is designed in consideration of chromatic dispersion as in the lens body 52 of the fourth modification example, the white light rays X1, X2 emitted from the light emission point 51B of the LED light source 51, How X3 is actually irradiated through the lens body 52 will be described.

  First, since the white light ray X1 incident perpendicularly to the incident surface 52a is not refracted at the incident surface 52a, the white light ray X1 travels through the lens body 52 without causing chromatic dispersion (color separation) as it is, and reaches the position T1 of the reflecting surface 52c. Incident. The white light beam X1 incident on the reflecting surface 52c is reflected in the direction along the optical path CLD1, and is irradiated (emitted from the emitting surface 52b) in the angle direction of the light / dark boundary line CL, which is a design target. That is, the optical paths of the white light rays X1, X2, and X3 in the figure are optical paths when assuming a constant reference refractive index over the entire wavelength range of the white light rays, and the reference refractive index is the refractive index of the green light ray. The green light beam G1 included in the white light beam X1 passes through the same optical path as that of the white light beam X1 shown in FIG. In addition, light rays such as red and blue other than the green wavelength included in the white light beam X1 are not refracted at the incident surface 52a (and the output surface 52b), and thus are not separated and are the same as the white light beam X1. The light passes through the optical path and is irradiated in the angular direction of the light / dark boundary line CL which is the design target. Therefore, the white light beam X1 emitted from the light emission point 52B and perpendicularly incident on the incident surface 52a is irradiated in the angular direction of the light / dark boundary line CL, which is the design target, to form a white light / dark boundary line CL. To do.

  On the other hand, when the white light beam X2 obliquely incident on the incident surface 52a from the front side of the vehicle is incident on the incident surface 52a, refraction occurs and color separation occurs inside the lens body 52 due to chromatic dispersion. At this time, in the lens body 52, the green light ray G2 included in the white light ray X2 travels along the same optical path as the white light ray X2 when a constant reference refractive index is assumed, and enters the position T2 of the reflecting surface 52a. . Then, the light is reflected by the reflecting surface 52c in the downward angular direction with respect to the optical path CLD2, and is irradiated in the downward angular direction with respect to the angular direction of the light / dark boundary line CL as the design target.

  On the other hand, since the red light ray R2 (dotted line) included in the white light ray X2 has a refractive index smaller than the reference refractive index (refractive index of the green wavelength), it is smaller than the green light ray G2 at the incident surface 52a. The light beam is refracted at a small refraction angle, travels along an optical path in the angular direction that is on the vehicle front side of the optical path of the white light beam X2 (the optical path of the green light beam G2), and enters the vicinity (upper side) of the reflection surface 52c at the position T2. And since the incident angle to the reflecting surface 52c becomes larger than the white light beam X2 (green light beam G2), the red light beam R2 is reflected in the upward angular direction than the white light beam X2 (green light beam G2). The At this time, considering how much the red light ray R2 is reflected in the upward angular direction with respect to the white light ray X2 (green light ray G2), the red light ray R2 is upward from the light / dark boundary line CL of the design target. The target irradiation direction of the white light beam X2 (green light beam G2) is set so as not to be irradiated in the angular direction, and the shape of the reflection surface 16 is set. Accordingly, the red light ray R2 is reflected by the reflecting surface 52c in an angular direction substantially along the optical path CLD2 or in an angular direction downward from the optical path CLD2. As a result, the red light ray R2 is emitted from the emission surface 52b in an angular direction that is not upward from the design target light / dark boundary line CL.

  Note that a blue light beam (not shown) included in the white light beam X2 is also separated by the incident surface 52a and passes through an optical path different from that of the white light beam X2 (green light beam G2) shown in FIG. However, since the red light ray R2 is emitted from the emission surface 52b in the downward angle direction with respect to the white light ray X2 (green light ray G2) as opposed to the red light ray R2, the red light ray R2 is more than the design target light / dark boundary line CL. By irradiating in an angular direction that does not face upward, blue light is inevitably emitted in an angular direction that does not face upward from the design target light / dark boundary line CL.

  Further, when the white light beam X3 obliquely incident on the incident surface 52a from the rear side of the vehicle is incident on the incident surface 52a, refraction occurs and color separation occurs inside the lens body 52 by chromatic dispersion. At this time, in the lens body 52, the green light ray G3 included in the white light ray X3 travels on the same optical path as the white light ray X3 when a constant reference refractive index is assumed, and enters the position T3 of the reflecting surface 52c. . Then, the light is reflected by the reflecting surface 52c in the downward angular direction with respect to the optical path CLD3, and irradiated in the downward angular direction with respect to the angular direction of the light / dark boundary line CL that is the design target.

  On the other hand, since the blue light ray B3 (dotted line) included in the white light ray X3 has a refractive index larger than the reference refractive index (refractive index of the green wavelength), the incident surface 12 has a higher refractive index than the green light ray G3. The light beam is refracted at a large refraction angle, travels along an optical path in the angular direction on the front side of the vehicle with respect to the optical path of the white light beam X3 (the optical path of the green light beam G3), and enters the vicinity (upper side) of the reflective surface 52c at the position T3. The blue light ray B3 is reflected in an upward angle direction with respect to the white light ray X3 (green light ray G3) because the incident angle on the reflecting surface 52c is larger than that of the white light ray X3 (green light ray G3). The At this time, considering how much the blue light ray B3 is reflected in the upward angular direction with respect to the white light ray X3 (green light ray G3), the blue light ray B3 is directed upward from the light / dark boundary line CL of the design target. The target irradiation direction of the white light beam X3 (green light beam G3) is set so as not to be irradiated in the angle direction, and the shape of the reflection surface 52c is set. Accordingly, the blue light beam B3 is reflected by the reflecting surface 52c in an angular direction substantially along the optical path CLD3 or in an angular direction downward from the optical path CLD3. As a result, the blue light beam B3 is emitted from the emission surface 52b in an angular direction that is not upward from the design target light / dark boundary line CL.

  Note that a red ray (not shown) included in the white ray X3 is also separated by the incident surface 52a and passes through an optical path different from that of the white ray X3 (green ray G3) shown in the figure, but opposite to the blue ray B3. Are emitted from the emission surface 52b in a downward angle direction with respect to the white light ray X3 (green light ray G3), and therefore the blue light ray B3 is emitted in an angular direction that does not face the design target light / dark boundary line CL. As a result, the red light beam is inevitably irradiated in an angular direction that does not face upward from the design target light / dark boundary line CL.

  As described above, according to the light source unit 50A of the fourth modification, the white light emitted in each direction from the light emission point 51B of the LED light source 51 is not refracted in the lens body 52 and chromatic dispersion ( A light beam such as the white light beam X1 passing through the non-refractive optical path where no color separation occurs is irradiated in the angular direction of the light / dark boundary line CL, and a clear light / dark boundary line CL is formed by the white light. Further, the formation of the light / dark boundary line CL by the white light beam X1 maintains the chromaticity of the light / dark boundary line CL in the white range.

  On the other hand, for light rays such as white light rays X2 and X3 that pass through a refraction optical path where refraction occurs and chromatic dispersion occurs, the target irradiation direction (green color) when a constant reference refractive index is assumed in the entire wavelength range of white light rays. (Light irradiation direction) is set to an angle direction downward from the light-dark boundary line CL, and red or blue light rays irradiated to an angle direction upward from the green light beam by chromatic dispersion are directions of the light-dark boundary line CL, Or it irradiates in the downward angle direction. That is, the light of the wavelength band that is color-separated irradiates the light distribution pattern PA below the light / dark boundary line CL, and is mixed with the light emitted from locations other than the light emission point 51B in the light distribution pattern. Therefore, a problem that color blur (unintended illumination region Q) occurs due to color dispersion above the light / dark boundary line CL is prevented, and chromaticity variation (color unevenness) of illumination light is prevented.

  In the above description, only the light beam emitted from the light emission point 51B of the LED light source 51 is focused. Similarly, the light emission point in the vicinity thereof (the light emission point on the vehicle front side of the light emission point 51B). The white light emitted from) is also separated by chromatic dispersion to produce red or blue light upward from the green light. However, by correcting the shape of the reflecting surface 51c as described above, these rays are also emitted downward from the light / dark boundary line CL, and therefore, a problem of causing a color blur on the upper side of the light / dark boundary line CL. Has been resolved. In addition, the light rays emitted from the light emission point 51B and each of the light emission points in the vicinity of the light emission point 51B are not irradiated with concentrated light rays in the same wavelength region in the same direction, but are irradiated with a spread. Since the color is mixed with light rays emitted from other light emission points, color unevenness of illumination light does not occur in the light distribution pattern PA.

  Here, the chromatic dispersion in the lens body 52 as described above is emitted from a white light ray emitted from the light emission point 51B in a direction other than within the vertical cross section of FIG. 76 or from a light emission point other than the light emission point 51B. Also, the white light beam generated for the light beam that passes through the light path (refracting light path) where refraction occurs, and the light beams in the respective wavelength ranges separated by chromatic dispersion are irradiated from the emission surface 52b in different directions. Basically, white light that passes through an optical path that irradiates light in a direction other than the vicinity of the edge in the light distribution pattern PA is superimposed and mixed with light emitted from other light emission points even when color separation is performed. Does not cause uneven color of illumination light.

  On the other hand, light is emitted in the direction of the boundary of the left end, the right end, and the lower end of the light distribution pattern PA like white light that passes through the refractive light path that irradiates light in the direction of the light / dark boundary line CL that is the upper edge of the light distribution pattern PA. When the white light beam that passes through the refracting optical path to be irradiated is color-separated, only the light in a part of the wavelength range of the light beam that has been color-separated outside the boundary (red, blue, or mixed color light) is irradiated, Color blur may occur.

  Therefore, as for the light rays irradiated to these boundaries, similarly to the light rays irradiated in the direction of the above-mentioned light / dark boundary line CL, the light distribution pattern PA whose design target is the light rays in all the wavelength regions separated in color. The color of the boundary is obtained by correcting the reflecting surface 52c with respect to the reflecting surface of the basic shape so as to be irradiated inside, and superimposing the color-separated light beam with a light beam emitted from a light emitting point different from the light beam. The occurrence of bleeding can be prevented, and the color unevenness of the illumination light can be reduced.

  It should be noted that the color-separated light beam applied to the boundary portion including the light / dark boundary line CL of the light distribution pattern PA is not simply irradiated into the light distribution pattern PA, but the color-separated light beams in the respective wavelength ranges are wide-ranged. If the light is spread in the direction of, the color unevenness of the illumination light can be reduced more effectively. Further, color unevenness of illumination light can be more effectively prevented by irradiating a color-separated light beam to a region that is brightly illuminated with white light (the light emission color of the LED light source) by another light beam. . Furthermore, you may make it irradiate the area | region currently illuminated brightly by the other light source units 50B-50D with the light beam of each wavelength range which carried out color separation.

  In addition, when an LED light source using a wavelength conversion material as a light source is used to form a light / dark boundary, it is energy to form the light / dark boundary by using it as effectively as possible without shielding the light flux emitted from the LED chip. It is also preferable from the viewpoint of utilization efficiency. Therefore, it is preferable to use the end portion of the LED light source 51 as a light / dark boundary, in particular, as a light / dark boundary line CL in the vicinity of the H line of the headlamp for passing light distribution. In this case, since the LED light source 51 is provided with the wavelength conversion material layer as far as the LED end as shown in FIG. 84, color unevenness is more likely to occur at the end of the LED light source 51 than at the center. This has a potential problem in that when the LED light source 51 is enlarged and projected by the lens body 52, the color unevenness of the LED light source 51 is projected as it is onto the light / dark boundary line CL. In the present embodiment, as described above, since the lens body 52 takes the color dispersion into consideration on the light / dark boundary line CL, the color unevenness can be reduced even when the color unevenness occurs at the end of the LED light source 51. It becomes possible.

  That is, as shown in FIG. 75, the light emitted from the light emission point 51B, which is the rear end of the LED light source 51, is spread and irradiated as a whole in the direction in the light distribution pattern PA that is downward from the light / dark boundary line CL. (Along with the spread of light by color separation, the spread of the emission direction of the white light beam (green light beam) reflected from each point of the reflection surface 52c from the emission surface), and the light emission different from the light emission point 51B of the LED light source 51 Since the light emitted from the point is superimposed and mixed, the color unevenness of the illumination light caused by the color unevenness at the end of the LED light source 51 is combined with the color unevenness of the illumination light due to the color dispersion of the lens body 52. It is reduced. Therefore, in order to prevent the color unevenness of the illumination light of the headlamp 50, the conditions regarding the color unevenness of the LED light source 51 itself are relaxed, and the types of light sources that can be selected as the LED light source 51 of the headlamp 50 are expanded. The management conditions for color unevenness that occurs in mass production can be relaxed. Note that, in the direction of the boundary between the left end, the right end, and the lower end of the light distribution pattern PA, the color blur (color unevenness) due to the color dispersion of the lens body 52 is caused in the same manner as the light irradiated in the direction of the light / dark boundary line CL. When the reflection surface 52c is corrected with respect to the basic shape so as to prevent, the color unevenness of the illumination light caused by the color unevenness at the end of the LED light source 51 that emits light in the direction of the boundary between them is also reduced. Is done.

  Further, in order to make the explanation easy to understand, the white light beam X1 reflected at the position T1 has been described as matching the non-refractive optical path. As a definition of a non-refractive optical path, an optical path that does not cause refraction at all is desirable as a strictly narrow definition. However, as described above, it is necessary to consider the refraction of the exit surface 52b. Therefore, in this specification, the non-refractive optical path is to be interpreted in a broad sense, that is, an optical path serving as a reference with a small refraction level at which chromatic dispersion need not be considered.

  FIG. 79 shows the horizontal direction of the light distribution pattern P of the headlamp 50 shown in FIG. 76 configured by the light source units 50A to 50D configured as described above. A measurement value table showing the results of actual measurement of chromaticity and luminous intensity at measurement points L0 to L6 from 0 degree to 30 degrees by shifting the measurement point left from 0 degree on the V line by 5 degrees on the V line. is there. FIG. 80 and FIG. 81 show the actual measurement values relating to the chromaticity of each measurement point on the chromaticity diagram of the CIE color system based on the actual measurement value table. In the present specification, the numerical values of x and y representing chromaticity indicate values in the CIE color system. In addition, in FIGS. 79 to 81, in addition to the data relating to the vehicular lamp 50 of the present embodiment (described as “the lamp of the present application”), an HID bulb (metal hydride discharge lamp), which is a conventional product, is used as a light source for reference. The measurement results obtained by actually measuring the chromaticity and luminous intensity of the headlamp (projector-type headlight for passing light) are shown as data of “A lamp”.

  First, in the LED light source 51 of the fourth modification, the chromaticity is different depending on the position of the light emission point, but the average value is x = 0.3179, y = 0.3255, and the color temperature. Equivalent to 6248K is used. As the HID light source of the A lamp, a chromaticity characteristic having an average value of x = 0.3362, y = 0.3509, and a color temperature corresponding to 5346K is used.

  Since the LED light source 51 of the present modification 4 and the HID light source of the A lamp have different chromaticities, the chromaticity of the illumination light emitted from each lamp also differs. However, as shown in FIG. Illumination light of a color within a chromaticity range W that is recognized as being irradiated.

  FIG. 79 shows the light intensity (cd) actually measured at the measurement points L0 to L6 in the light distribution region of both the headlamp 50 and the lamp A according to the fourth modified example up to the 30 degree direction on the left side. In addition, the measured value at the measurement point where the maximum luminous intensity is obtained among the measurement points L0 to L6 is 100%, and the luminous intensity at the other measuring points is shown as a percentage (%) with respect to the maximum luminous intensity. According to this, the headlamp 50 of the fourth modification has a value of 20% or more with respect to the maximum luminous intensity value at the measurement point L1 (left direction of 5 degrees) up to the measurement point L6 (left direction of 30 degrees). It can be seen that the wide area on the left side is brightly illuminated even when the lamp A is 3.6% at the measurement point L6. Although not shown in FIG. 79, the headlamp 50 of the present embodiment showed a luminous intensity value of about 500 cd in the direction of 65 degrees on the left side.

  Regarding the chromaticity, as can be seen by comparing the distribution of chromaticity at the measurement points L0 to L6 of the headlamp 50 of the present modification 4 and the A lamp shown in the chromaticity diagrams of FIGS. It can be seen that the variation in the chromaticity of the illumination light of the headlamp 50 of the modified example 4 is reduced to a sufficiently small range even when compared with the A lamp. Comparing numerically, the difference between the maximum value and the minimum value for each of the chromaticity x, y from the measurement point L0 (H = 0 °) on the V-line in front of the vehicle to the measurement point L6 in the direction of 30 degrees to the left ( The change amounts Δx and Δy in the headlamp 50 according to the fourth modification are Δx = 0.0099 (about 0.01) and Δy = 0.177 (about 0.02), whereas the lamp A Then, Δx = 0.025 and Δy = 0.032.

  As can be seen from this numerical value, the headlamp 50 of the present modification 4 is within a sufficiently small variation in chromaticity from the 0 degree direction, which is the front direction of the vehicle, to the 30 degree direction on the left side, which is the sidewalk side. It can be seen that a light distribution pattern with less unevenness is formed.

  In addition, although the variation in chromaticity varies depending on individual differences, in the headlamp 50 according to the fourth modification, the illumination light applied to the measurement point L4 in the left 20-degree direction is the measurement point on the V line that is the front of the vehicle. Variations (changes) Δx and Δy in chromaticity x and y with respect to illumination light irradiated on L0 (H = 0 °) can be set to Δx ≦ 0.002 and Δy ≦ 0.02. In the range from the front of the vehicle to the left 20 ° direction, if chromaticity variation can be suppressed to this extent, there is a practically sufficient effect.

  The illumination light applied to the measurement point L6 in the 30 ° direction on the left side has chromaticity x and y with respect to the illumination light applied to the measurement point L0 (H = 0 °) on the V line on the front of the vehicle. Variations (variations) Δx and Δy are Δx ≦ 0.01 and Δy ≦ 0.03, and variations in chromaticity x and y with respect to illumination light irradiated to the measurement point L2 in the 10 ° direction on the left side (Changes) Δx and Δy are more preferably set to satisfy Δx ≦ 0.01 and Δy ≦ 0.02, and the headlamp 50 of Modification 4 satisfies this condition.

  FIG. 80 also shows a black body radiation locus, equal color temperature line, and equal deviation line on the chromaticity diagram, and shows the chromaticity (color correlation temperature) of the headlamp 50 of the fourth modification. ) Is within the white chromaticity range W, and the correlated color temperature / BR> X is within a range of 5000K or more (7000K or less). On the other hand, the chromaticity of the A lamp is in a range of about 5000K or less (4000K or more), and the headlamp 50 of the fourth modification is in a range closer to blue among white. This difference is caused by the difference in the chromaticity of the light source. However, like the headlamp 50 of the fourth modification, illumination light in the chromaticity range in which the correlated color temperature is 5000 K or more is illuminated. Since the color of the object could be easily identified, it was judged that the color rendering property was excellent.

[Headlamp unit (Modification 5)]
75, Modification 5 of the configuration of the light source units 50A to 2D of the headlamp 50 according to Modification 4 of FIG. 75 is shown, and the occurrence of color blurring (unintended color-separated illumination area Q) at the light / dark boundary line CL is prevented. This is shown.

  First, the case where the LED light source 51 in a different package form is used will be described. FIG. 85 is a drawing showing packaging of LED chips having different forms using the same LED chip 200 as FIG. 84, wherein FIG. 85 (A) is a plan view and FIG. 85 (B) is in FIG. BB line sectional drawing and the figure (C) are AA line sectional views in the figure (A).

  In FIG. 85, three InGaN LED chips arranged in a straight line with the same predetermined gap as in FIG. 84 are used, and the convex wavelength conversion material layer 204 is formed only on the upper surface of each LED chip 200. It is supposed to be covered with. In order to form the wavelength conversion material layer in a convex shape only on the upper surface of each LED chip, for example, the surface is obtained by curing a liquid translucent resin material in which the wavelength conversion material is dispersed after being appropriately applied by a dispensing method or the like. It can be formed using tension.

  In Modification 4 described above, the case where the LED light source 51 shown in FIG. 84 is used has been described. The same examination was performed by changing only the point using the LED light source shown in FIG. 85 instead of the LED light source 51 shown in FIG. The color temperature and chromaticity were almost the same as when the LED light source 51 shown in FIG. 54 was used. Also in this case, the color unevenness of the illumination light could be reduced.

  In both cases of the packaging shown in FIG. 84 and the packaging shown in FIG. 85, variations in the thickness and concentration of the wavelength conversion material layer and variations in position occur in the manufacturing process. Also, the LED chip itself has variations in brightness. Therefore, naturally the variation of the LED light source 51 also occurs. When color unevenness occurs due to variations in the LED light source, the configuration of the above-described embodiment can overlap the light emitted from different light emission points and reduce the color unevenness of the illumination light. It becomes possible.

  FIG. 82 is a vertical sectional view showing the configuration of Modification 5 of the light source unit 50A. Elements that are the same as or similar to those of the light source unit 50A of Modification 4 in FIG. 76 are denoted by the same reference numerals or prime symbols. The light source unit 50A shown in FIG. 82 is different from the light source unit 50A shown in FIG. 76 in the shape of the incident surface 52a ', and is formed by a concave surface instead of a flat surface. The reflection surface 52c ′ of the lens body 10 is formed so as to form the light distribution pattern PA of FIG. 77.

  The incident surface 52a ′ is, for example, in the shape of a circular arc (light emission of the LED light source 51) centered on a position away from the light emission point 51B of the LED light source 51 with respect to the incident surface 52a ′ on the vertical sectional view of FIG. The center of the arc is located on a straight line passing through the light emission point 51B and the position T1 ′ near the center of the reflecting surface 52c ′. It is formed by the concave surface of the circular arc. Therefore, the incident angle when white light emitted in each direction from the light emission point 51B is incident on the incident surface 52a ′ is generally smaller than that in the light source unit 50A of the fourth modification, and the incident light on the incident surface 52a ′. The chromatic dispersion due to refraction is small.

  The shape of the reflecting surface 52b ′ is designed in consideration of the chromatic dispersion generated in the lens body 52. Of the white light rays emitted from the light emitting point 51B in each direction, the reflecting surface 52b ′ is incident on the incident surface 52a ′ perpendicularly. For the white light beam X1 ′ in which refraction does not occur on the incident surface 52a ′ and the exit surface 52b of 52, the target irradiation direction is set to the angle direction of the light / dark boundary line CL, and as shown in FIG. The shape (position and position) of the reflecting surface 52c ′ at the position T1 ′ is such that the white light beam X1 ′ (green light beam G1 ′) incident on the position T1 ′ is reflected in the angular direction of the light / dark boundary line CL along the optical path CLD1 ′. (Tilt) is formed.

  On the other hand, the white light rays (white light rays X2 ′ and X3 ′) that are incident on the incident surface 52a ′ and refracted at the incident surface 52a ′ with respect to the vehicle front side or the vehicle rear side with respect to the white light ray X1 are colors generated by the refraction. The target irradiation direction is set to an angular direction downward from the design target light / dark boundary line CL according to the size of dispersion (color separation), and a constant reference refractive index is assumed for the entire wavelength range of white light. In this case, the white light rays X2 'and X3' (green light rays G2 'and G3') incident on the positions T2 'and T3' above and below the position T1 'of the reflecting surface 52c' are converted into the angular direction of the light / dark boundary line CL. The shape of the reflecting surface 52c ′ is designed so as to irradiate (reflect) in an angle direction downward from (optical paths CLD2 ′, CLD3 ′).

  According to this, since the light dispersion at the incident surface 52a ′ is smaller than that of the light source unit 50A of the modified example 4, it is possible to reduce the occurrence of color blur on the upper side of the light / dark boundary line CL. In order to completely prevent the occurrence of the color blur, the angle with the irradiation direction of the white light (green light) downward may be small, the change to the shape of the reflecting surface 52c ′ is small, and the light / dark boundary The influence on the light distribution in other illumination areas other than the line CL can also be reduced.

  The incident surface 52a 'may have an elliptical arc or a circular cross section in the vertical direction, and the same effect as described above can be obtained as long as it is a concave surface when viewed from the light emission point 51B. If the shape of the incident surface 52a ′ is a spherical surface with the light emission point 51B as the center point, the incident angle from the light emission point 51B is 0 degrees and no refraction occurs, so that color separation caused by the incident angle does not occur. Can do. However, in this case, the light utilization efficiency is lowered unless the reflecting surface is set so as to cover the spherical surface corresponding to the spherical surface corresponding to the light incident from the spherical incident surface. That is, the lens body is increased in size. Therefore, it is preferable to design the concave curved surface so as to reduce the chromatic dispersion in consideration of the balance between the amount of light emitted from the light emitting surface 51A and the size of the reflecting surface 52c. More preferably, as shown in FIG. 82, the curvature of the incident surface near the reflecting surface is close to a spherical surface centered on the light emission point 51B.

[Headlamp unit (Modification 6)]
FIG. 83 is a vertical sectional view showing the configuration of Modification 6 of the light source unit 50A. Elements that are the same as or similar to those of the light source unit 50A in the modification 4 of FIG. 76 are denoted by the same reference symbols or double prime symbols. The light source unit 50A shown in FIG. 83 differs from the light source unit 2A shown in FIG. 76 in that the light emitted from the LED light source 51 is guided to the reflection surface 52c ″ corresponding to the reflection surface 52c in FIG. The incident surface 52a ″ is formed on the back side (vehicle rear side) of the lens body 52, and the LED light source 51 is arranged on the back side of the lens body 51 with the light emission surface 51A facing the vehicle front side.

  Further, the light from the LED light source 51 that has entered the lens body 52 from the incident surface 51a ″ is not directly incident on the reflecting surface 52c ″, but is reflected once by the reflecting surface 103 different from the reflecting surface 52c ″. To the reflecting surface 52c ″. That is, the light from the LED light source 51 that has entered the lens body 52 from the entrance surface 52a ″ is reflected twice inside the lens body 52 and then exits from the exit surface 52b. Aluminum is vapor-deposited on the outer surface portion where the reflecting surface 103 is formed, and the reflecting surface 103 that reflects light inside the lens body 52 is formed.

  In the light source unit 50A having such a configuration, similarly to the light source unit 50A of the fourth modification, it is possible to prevent a problem that color blur occurs on the upper side of the light / dark boundary line CL.

  That is, the shape of the reflecting surface 52c ″ is designed in consideration of the chromatic dispersion generated in the lens body 52, and of the white light rays emitted from the light emitting point 51B in each direction, the shape of the reflecting surface 52c ″ is perpendicularly incident on the incident surface 52a ″. For the white light beam X1 ″ that is not refracted at the entrance surface 52a ″ and the exit surface 52b of the lens body 52, the target irradiation direction is set to the angular direction of the light / dark boundary line CL, and as shown in FIG. The shape of the reflecting surface 52c "at the position T1" so that the white light ray X1 "(green light ray G1") incident on the "position T1" is reflected in the angular direction of the light / dark boundary line CL along the optical path CLD1 "( Position and tilt).

  On the other hand, the white light rays (white light rays X2 ″ and X3 ″) that enter the incident surface 52a ″ from the position above or below the vehicle with respect to the white light beam X1 ″ and are refracted at the incident surface 52a ″ are refracted. The target irradiation direction is set to an angular direction downward from the design target light / dark boundary line CL in accordance with the magnitude of chromatic dispersion (color separation) caused by the above, and the reference refractive index is constant for the entire wavelength range of white light. , White light rays X2 ″ and X3 ″ (green light rays G2 ″ and G3 ″) incident on positions T2 ″ and T3 ″ above and below the position T1 ″ of the reflecting surface 52c ″ are bright and dark boundary lines CL. The shape of the reflecting surface 52c ″ is designed so as to irradiate (reflect) in the angle direction downward from the angle direction (optical path CLD2 ″, CLD3 ″).

  According to the light source unit 50A of the sixth modification, by providing a plurality of reflection surfaces (52c ″, 102) that reflect light inside the lens body 52, the range of selection of the arrangement location of the LED light source 51 can be widened. That is, it is possible to change the location of the LED light source 51 to a position different from that shown in FIG. 83 by changing the positions of the incident surface 52 a ″ and the reflecting surface 103. And even if it is the aspect which provided multiple reflective surfaces, the irradiation direction of the green light ray (white light ray when a fixed reference refractive index is assumed) passing through the optical path where refraction occurs is the angle direction of the light-dark boundary line CL If the shape of the reflecting surface 53c ″ is set so as to be in a downward angle direction (corrected from the basic shape), it is possible to prevent color blur from occurring on the upper side of the light / dark boundary line CL.

  In Modification 6, the lens body 52 configured to reflect the light incident on the inside of the lens body 52 twice inside the lens body 52 and exit from the exit surface 52b is shown. However, the light incident on the inside of the lens body 52 is shown. Even in the case of a vehicle lamp using a lens body that is reflected three times or more inside the lens body 52 and exits from the exit surface 52b, color blur is generated above the light / dark boundary line CL in the same manner as in the above embodiment. Occurrence can be prevented.

  In the above modified example 5 and modified example 6 as well, as described in modified example 4, there is a possibility that color unevenness may occur at the boundary portions of the left end, right end, and lower end of the light distribution pattern. This can be prevented in the same manner as described in the fourth modification.

  Moreover, in the said modification 4-6, the non-refractive optical path which is not refracted in the lens body 10 among the light rays emitted from the light emission point 51B of the LED light source 51 is the vertical direction of the reflecting surface 52c (52c ', 52c "). Although it passes through substantially the center, the position where the non-refractive optical path passes through the reflecting surface 52 (52 ', 52 ") is not limited to this. For example, you may make it pass the substantially lowermost part or substantially uppermost part of the reflective surface 52c (52c ', 52c ").

  Further, in the above modified examples 4 to 6, only the shape of the reflection surface 52c (52c ′, 52c ″) of the lens body 52 is corrected from the basic shape. , The incident surface 52a (52a ′, 52a ″), the reflective surface 16 (52c ′, 52c ″, the reflective surface 103), and the exit surface 52b (52b ′), at least one surface (any one or more surfaces). The shape may be corrected with respect to the basic shape.

  Moreover, in the said modification 4-6, although the light emission surface 51A of the LED light source 51 was enlarged and projected to the illumination area | region as a basic shape of each surface of the lens body 52, it is not restricted to this. For example, in the light source unit 50A of Modification 4 in FIG. 76, when designing the basic shape of each surface of the lens body 52, white light emitted in the different directions from the same light emission point of the LED light source 51 is distributed over a wide range. Refraction light path by making the basic shape a shape that diffuses and illuminates the illumination area, or a shape that irradiates and mixes white light emitted from spaced light emission points so as to overlap the same illumination area Even when white light rays passing through the light source are color-separated, the light rays color-separated in a similar manner from adjacent light emitting points of the LED light source 51 are not superimposed in the illumination area, but are color-separated in various ways. The light rays from the respective optical paths are superimposed (mixed) in the illumination area. Therefore, the color unevenness of the illumination light (including the color unevenness of the illumination light caused by the color unevenness of the LED light source 51) can be further reduced, and the correction amount for the basic shape can also be reduced.

  As an example of the basic shape of each surface of the lens body 52 in this case, in the above-described embodiment, white light emitted from the light emission point 51B at the rearmost end of the LED light source 51 is irradiated in the direction of the light / dark boundary line CL. The white light emitted from the light emitting point at the foremost end of the LED light source 51 is irradiated to the lower edge of the light distribution pattern PA, but is emitted from the light emitting point at the foremost end of the LED light source 51. The shape of each surface of the lens body 52 may be a basic shape such that a white light beam is irradiated in a region other than the lower end edge of the light distribution pattern PA and an area to be brightly illuminated (near the upper end edge).

  Further, the reflecting surface of the lens body 52 is subdivided into fine minute surfaces, and a minute surface that irradiates an illumination region (illumination region having a narrow vertical width) that irradiates white light incident on the reflecting surface in the left-right direction; The illumination area (illumination area with a narrow width in the left-right direction) that irradiates light is alternately arranged vertically and horizontally, and the white light emitted from the light emission point in the vicinity of the LED light source 51 is irradiated to different illumination areas. In addition, the white light emitted from the separated light emission points may be mixed. Such light distribution control can also be performed between light source units when the headlamp 50 forms one light distribution pattern with a plurality of light source units as shown in FIG.

  In the light source units shown in Modifications 4 to 6, the lens body 52 is formed of a polycarbonate material, but the lens body 52 is made of a material other than the polycarbonate material (for example, a transparent material such as glass or acrylic). Even if it is formed by the above method, the present invention can be applied in the same manner as in the above embodiment in order to prevent color unevenness of illumination light regardless of the degree as long as the material causes color dispersion.

  Further, the light source units shown in the above-described modified examples 4 to 6 not only prevent uneven distribution of illumination light, but also have a double refraction when the material of the lens body 52 has a birefringent property like a polycarbonate material. It is possible to reduce blurring of a light / dark boundary caused by refraction. For example, a polycarbonate material has a large residual stress at the time of molding, and has a birefringent property due to the high photoelastic modulus peculiar to the material, and is emitted from the light emission point 51B of the LED light source 51 due to the influence of the birefringence. Among the received light rays, the light rays obliquely incident on the incident surface 52a (52a ′, 52a ″) (light rays refracted by the incident surface 52a) are complicatedly separated in a plurality of directions. If it is designed so that white light (green light) is assumed to be irradiated in the angular direction of the light / dark boundary without considering birefringence and assuming a constant reference refractive index, the light beams separated by birefringence are bright and dark. Causes blurring of the boundary.

  On the other hand, by designing so that the color-separated light beam is irradiated in the angle direction inside the light-dark boundary as described above, the influence of the light beam separated by birefringence on the light-dark boundary is also reduced. Occurrence of blurring of the light / dark boundary is also prevented.

  Further, in the above-described modified examples 4 to 6, the shape (basic shape) of the exit surface 52b of the lens body 52 is a plane, and the reflecting surface 52c (52c ′, 52c ″ is formed in the angular direction near the design target light / dark boundary line CL. However, the basic shape of the exit surface 52b is not a flat surface (for example, a concave surface or a convex surface), and refraction occurs on the exit surface 52b. However, the present invention can be applied.

  That is, according to the present invention, among the light rays emitted from the respective light emission points of the LED light source 51, the color passes through the refraction light path where refraction occurs at either the incident surface 52a (52a ′, 52a ″) or the exit surface 52b. It is only necessary to form at least one of the incident surface, the reflecting surface, and the emitting surface so that the separated light beams in each wavelength region overlap with light emitted from other light emitting points in the light distribution pattern. .

  In the above modification, the vehicle lamp applied to the headlamp that irradiates the illumination light with the light distribution pattern for passing light is exemplified. However, the present invention is not limited to the headlamp for passing light distribution, The present invention can be applied to other types of vehicle lamps such as beam headlamps and fog lamps.

  As described above, according to the modification examples 4 to 6, the light emitted from the end portion 51B of the LED light source 51 is mixed with the light emitted from a point other than the end portion 51B of the LED light source 51. It becomes possible to prevent or reduce the color unevenness of the partial light distribution pattern PA caused by the color unevenness at the end 51B of the LED light source 51.

  The above embodiment is merely an example in all respects. The present invention is not construed as being limited to these descriptions. The present invention can be implemented in various other forms without departing from the spirit or main features thereof.

  DESCRIPTION OF SYMBOLS 10 ... Headlamp, 10A-10B ... Headlamp unit, 11 ... LED light source, 12A-12D ... Lens body, 13 ... Heat sink

Claims (4)

In a vehicle headlamp including at least one headlamp unit configured to irradiate light used to form a partial light distribution pattern constituting a low-beam light distribution pattern in a predetermined white range,
The headlamp unit is:
An LED light source;
A light incident surface on which the light emitted from the LED light source is incident on the inside of the lens, an output surface, and light that is incident on the lens from the light incident surface is internally reflected, and the reflected light is emitted from the output surface to be a light / dark boundary. A solid lens body including a reflective surface configured to form a predetermined light distribution pattern having lines;
With
The reflective surface is
Light of a reference wavelength that is radiated from one side of the LED light source corresponding to the light / dark boundary line and is incident perpendicularly to the light incident surface and is not refracted is internally reflected, and the reflected light is emitted from the light exit surface. A first reflective region configured to form the light-dark boundary line;
Light having a wavelength longer than the reference wavelength emitted from one side of the LED light source corresponding to the light / dark boundary line and incident on the light incident surface at an angle other than perpendicular and refracted according to the incident angle and incident on the inside of the lens. A second reflection region configured to be internally reflected and the reflected light is emitted from the emission surface and distributed below the light-dark boundary line;
Light having a shorter wavelength than the reference wavelength emitted from one side of the LED light source corresponding to the light / dark boundary line and incident on the light incident surface at an angle other than perpendicular and refracted according to the incident angle and incident on the inside of the lens. A third reflection region configured to be internally reflected, and the reflected light is emitted from the emission surface and distributed below the light-dark boundary line;
Contains
The LED light source has a color temperature of 4500 to 7000 [K], and four coordinate values (a *, representing prediction of appearance when irradiated with color charts of four colors (red, green, blue, yellow) . b *) is a coordinate value R (41.7, 20.9), G (-39.5 on the a * -b * coordinate system where the vertical axis corresponding to the CIE1976L * a * b * space is a * and the horizontal axis is b *. , 14.3), B (8.8, -29.9), Ri LED light source der contained in a circle within a radius of 5 centered on the Y (-10.4,74.2),
The LED light source is a white LED light source including a blue or ultraviolet light emitting LED element and a wavelength conversion material, or an LED light source that is a combination of LEDs of three colors of red, green, and blue. A vehicle headlamp that emits white light in a chromaticity range surrounded by a straight line connecting (0.323, 0.352), (0.325, 0.316), (0.343, 0.331), and (0.368, 0.379) . The second reflection region internally reflects light having a wavelength longer than a reference wavelength incident on the lens, and the reflected light is emitted from the emission surface and distributed on the light / dark boundary line or in the predetermined light distribution pattern. Configured to
The third reflection region internally reflects light having a wavelength shorter than a reference wavelength incident on the lens, and the reflected light is emitted from the emission surface and is distributed on the light / dark boundary line or in the predetermined light distribution pattern. The vehicle headlamp according to claim 1, wherein the vehicle headlamp is configured as described above.   The reflection surface is formed so that light emitted from an end portion of the LED light source is emitted from the emission surface in a direction in which the light spreads inward of the light / dark boundary line and the predetermined light distribution pattern. The light emitted from the end of the light source is formed so as to be superimposed on the light emitted from a point on the light emitting surface other than the end on the light emitting surface of the LED light source. The vehicle headlamp according to 1 or 2. The LED light source for a vehicle headlamp according to any one of claims 1 to 3, characterized in that the color temperature is an LED light source that the light emission in the range of 5000-6000 [K].