JP7472618B2 - Light guide for vehicle and vehicle lamp unit - Google Patents

Description

The present invention relates to a light guide for a vehicle and a vehicle lighting unit.

A configuration is known in which the functions corresponding to a reflector, shade, projection lens, etc. are integrated into one vehicle light guide (see, for example, Patent Document 1). That is, such a vehicle light guide has an entrance surface on which light from a light source is incident, an internal reflection surface (corresponding to a reflector) that internally reflects the incident light, a light shielding portion (corresponding to a shade) that shields a portion of the internally reflected light, and an exit surface (corresponding to a projection lens) that emits the light that is internally reflected and passes through the light shielding portion, thereby irradiating the light distribution pattern PF in front of the vehicle.

Patent No. 6130602

In the vehicle light guide described in Patent Document 1, it is necessary to improve the light utilization efficiency so that the light incident from the entrance surface can be internally reflected to reach the exit surface with as little loss as possible.

The present invention has been made in consideration of the above, and aims to provide a vehicle light guide and a vehicle lighting unit that can improve the efficiency of light utilization.

The vehicle light guide according to the present invention includes an entrance surface on which light from a light source is incident, a first reflecting surface that is disposed forward in the front-rear direction relative to the light source when the vehicle is mounted on the vehicle and that internally reflects the light incident from the entrance surface to form approximately parallel light, a second reflecting surface that has a second front region at its front end where the light reflected by the first front region is incident and that internally reflects the light reflected by the first reflecting surface forward, a light shielding portion that shields a portion of the light reflected by the second reflecting surface, a transmission surface that is provided in a state where it is folded back upward in the vertical direction when the vehicle is mounted on the vehicle and that transmits the light reflected by the second front region to the outside of the light guide and directs it forward, a re-entry surface that is disposed forward of the transmission surface and below the light shielding portion and that re-enters the light that has been transmitted from the transmission surface to the outside of the light guide, and an exit surface that emits the light internally reflected by the second reflecting surface and the light that has entered from the re-entry surface.

In the above vehicle light guide, the first reflecting surface has a first rear region located rearward of the light source, and the second reflecting surface has a second rear region located rearward of the second front region, and may further include a connecting surface extending forward from an upper end of the transmitting surface, connecting the transmitting surface and the light blocking portion, and internally reflecting a portion of the light internally reflected in the second rear region.

In the vehicle light guide described above, the second front region may be disposed below the light blocking portion.

In the above vehicle light guide, the connection surface may have an external light shielding portion that is arranged to protrude toward the outside of the light guide and blocks a portion of the light that is transmitted from the transmission surface to the outside of the light guide.

In the above vehicle light guide, the exit surface may project a light distribution pattern forward of the vehicle.

In the above vehicle light guide, the light distribution pattern may include a main pattern formed by the light internally reflected at the second rear region of the second reflecting surface, and an upper pattern formed by the light internally reflected at the second front region of the second reflecting surface and irradiated above the main pattern.

The vehicle lighting unit according to the present invention includes a light source and a plurality of the vehicle light guides described above that guide and emit light from the light source.

The present invention can improve the efficiency of light utilization.

FIG. 1 is a plan view showing an example of a vehicle lamp according to the present embodiment. FIG. 2 is a bottom view showing an example of a vehicle lamp according to the present embodiment. FIG. 3 is a diagram showing a configuration along the cross section AA in FIG. FIG. 4 is an enlarged view of a portion of FIG. FIG. 5 is a diagram showing an example of an optical path along which light is guided by the vehicle light guide. FIG. 6 is a diagram showing an example of a light distribution pattern projected onto a virtual screen in front of a vehicle. FIG. 7 is a diagram showing an example of a vehicle lamp unit according to this embodiment.

Below, an embodiment of a vehicle light guide and a vehicle lighting unit according to the present invention will be described with reference to the drawings. Note that the present invention is not limited to this embodiment. Furthermore, the components in the following embodiments include those that are easily replaceable by a person skilled in the art, or those that are substantially the same. In the following description, the front-rear, up-down, and left-right directions refer to directions when the vehicle headlamp is mounted on the vehicle and viewed from the driver's seat in the direction of travel of the vehicle. Note that in this embodiment, the up-down direction is parallel to the vertical direction, and the left-right direction is horizontal.

Figure 1 is a plan view showing an example of a vehicle lamp 100 according to this embodiment. Figure 2 is a bottom view showing an example of a vehicle lamp 100 according to this embodiment. Figure 3 is a diagram showing a configuration along the A-A cross section in Figure 1. Figure 4 is an enlarged view of a portion of Figure 3.

The vehicle lamp 100 can project a light distribution pattern PF (see FIG. 5) described below in front of the vehicle. In this embodiment, the light distribution pattern PF includes, for example, a low beam pattern P1, which is a main pattern, and an overhead pattern P2, which is an upper pattern. The vehicle lamp 100 includes a light source 10 and a vehicle light guide 20. The vehicle lamp 100 may further include other units having a light source, a reflector, a shade, a projection lens, etc. In the following, in this embodiment, the configuration of the vehicle lamp 100 mounted on a vehicle traveling on a left-hand traffic road is described as an example.

[light source]
In this embodiment, the light source 10 is, for example, a semiconductor light source such as an LED or an OLED (organic electroluminescence), a laser light source, or the like. The light emitting surface 11 is disposed opposite to an incident surface 21 of a vehicle light guide 20 described below. The light emitting surface 11 is disposed in a state facing the vehicle light guide 20. In this embodiment, a plurality of light sources 10, for example, four light sources 10, are disposed in the left-right direction. Note that the number of light sources 10 is not limited to four, and may be three or less, or five or more.

[Light guide for vehicle]
The vehicle light guide 20 guides light from the light source 10 and emits the light forward when mounted on the vehicle. The vehicle light guide 20 according to the present embodiment is configured to integrate functions corresponding to, for example, a reflector, a shade, a projection lens, and the like in a conventional projector-type vehicle headlamp. As shown in Figs. 1 to 3, the vehicle light guide 20 includes an incident surface 21, a first reflecting surface 22, a second reflecting surface 23, a light shielding portion 24, a transmitting surface 25, a connecting surface 26, a re-incident surface 27, and an exit surface 28.

[Incident surface]
A plurality of incident surfaces 21 are provided, for example, for each light source 10. The incident surfaces 21 may be provided at positions that do not correspond one-to-one to the light sources 10. For example, a configuration may be used in which a plurality of incident surfaces 21 are provided for one light source 10. The plurality of incident surfaces 21 are arranged side by side in the left-right direction when mounted on the vehicle. The incident surfaces 21 are formed, for example, in a truncated cone shape. In this embodiment, for example, four incident surfaces 21 are arranged. The diameter of the incident surface 21 arranged on the outside in the left-right direction may be smaller than the diameter of the incident surface 21 arranged on the center side in the left-right direction. In this embodiment, the diameters of the two incident surfaces 21 arranged on the outside in the left-right direction are smaller than the diameters of the two incident surfaces 21 on the center side in the left-right direction. Hereinafter, the two incident surfaces 21 on the center side in the left-right direction may be referred to as center side incident surfaces 21M, and the two incident surfaces on the outside in the left-right direction may be referred to as outer incident surfaces 21N, to distinguish between the two.

As shown in FIG. 3, each incident surface 21 has a first surface 21a and a second surface 21b. Light from the light source 10 is incident on the first surface 21a and the second surface 21b. The first surface 21a faces the light-emitting surface 11. The first surface 21a is a flat surface or a convex surface that protrudes toward the light source 10. The second surface 21b is disposed to the side of the light source 10 and is disposed in a cylindrical surface shape so as to surround the light-emitting surface 11 and the first surface 21a of the light source 10.

[First Reflecting Surface]
The first reflecting surface 22 internally reflects the light incident from the incident surface 21 to make it into a substantially parallel light. The first reflecting surface 22 is arranged to surround the second surface 21b of the incident surface 21, and reflects the light incident from the second surface 21b toward the second reflecting surface 23. In this embodiment, the first reflecting surface 22 is provided corresponding to the incident surface 21. A plurality of the first reflecting surfaces 22 are arranged side by side in the left-right direction when mounted on the vehicle. The plurality of second reflecting surfaces 23 include a light-collecting pattern reflecting surface 22M and a diffusion pattern reflecting surface 22N. The two light-collecting pattern reflecting surfaces 22M arranged at the center in the left-right direction are arranged in a state where they partially overlap each other.

Of the first reflective surfaces 22, for example, the light collecting pattern reflective surface 22M has a first rear region 22a and a first front region 22b. The first rear region 22a is disposed rearward with respect to the light source 10. In this embodiment, the first rear region 22a is disposed, for example, rearward in the front-rear direction with respect to an imaginary plane S that includes the optical axis AX of the light source 10 and is oriented forward. The first front region 22b is disposed forward with respect to the light source 10. In this embodiment, the first front region 22b is disposed, for example, forward with respect to the imaginary plane S.

[Second Reflective Surface]
The second reflecting surface 23 has a shape based on a paraboloid of revolution. The second reflecting surface 23 has a focal point P that coincides or nearly coincides with the focal point of the paraboloid of revolution. The focal point P is located at a position near the focal point of an exit surface 28 described below. The second reflecting surface 23 reflects light from the first reflecting surface 22 toward the focal point P, i.e., toward the front of the vehicle. The second reflecting surface 23 has an axis parallel to the optical axis of the light reflected by the first reflecting surface 22, and internally reflects the light toward the focal point P of the paraboloid of revolution.

As shown in FIG. 2, the second reflection surfaces 23 are arranged in a row in the left-right direction when mounted on the vehicle. The second reflection surfaces 23 include a light-collecting pattern forming surface 23M and a diffusion pattern forming surface 23N. The light-collecting pattern forming surface 23M internally reflects light from the first reflection surface 22 so that it passes through the focal point P and the vicinity of the focal point P. The light-collecting pattern forming surface 23M is arranged in the center in the left-right direction. The light-collecting pattern forming surface 23M is arranged corresponding to the two center side incident surfaces 21M. The light-collecting pattern forming surface 23M reflects light that is incident on the two center side incident surfaces 21M and reflected by the first reflection surface 22. When the vehicle light guide 20 is viewed from below, as shown in FIG. 2, the light-collecting pattern forming surface 23M can reflect light, for example, to the area between the virtual straight lines LMa and LMb in the left-right direction.

The diffusion pattern forming surface 23N internally reflects the light from the first reflecting surface 22 so that the light passes through a position including the focal point P and shifted outward in the horizontal direction from the focal point P when mounted on the vehicle. For this reason, the end of the diffusion pattern forming surface 23N on the light collecting pattern forming surface 23M side in the left-right direction has a shape that is deformed toward the focal point P (forward) from a shape based on a paraboloid of revolution. Of the multiple second reflecting surfaces 23, the second reflecting surface 23 arranged on the outside in the left-right direction from the light collecting pattern forming surface 23M is the diffusion pattern forming surface 23N. The diffusion pattern forming surface 23N is arranged corresponding to each outer incident surface 21N. The diffusion pattern forming surface 23N reflects the light that is incident on each outer incident surface 21N and reflected by the first reflecting surface 22. When the vehicle light guide 20 is viewed from below, as shown in FIG. 2, each diffusion pattern forming surface 23N can reflect light, for example, in the left-right direction in the area between the imaginary lines LNa and LNb, and in the area between the imaginary lines LNc and LNd.

When viewed from below as shown in FIG. 2, the reflected light internally reflected by the light-collecting pattern forming surface 23M mainly passes through the area between the virtual straight lines LMa and LMb in the left-right direction. Also, the reflected light internally reflected by the diffusion pattern forming surface 23N mainly passes through the area between the virtual straight lines LNa and LNb, and the area between the virtual straight lines LNc and LNd, and some of the light passes through the area between the virtual straight lines LNb and LNc (rear side in the front-rear direction). In this embodiment, a part of the area through which the reflected light internally reflected by the light-collecting pattern forming surface 23M mainly passes and through which some of the reflected light internally reflected by the diffusion pattern forming surface 23N passes is set as the area AR. The area AR has a shape that tapers from the second reflection surface 23 side toward the front. Also, the area AR has a shape along the virtual straight lines LNb and LNc that indicate the range through which the reflected light internally reflected by the diffusion pattern forming surface 23N mainly passes.

The light-collecting pattern forming surface 23M of the second reflecting surface 23 has a second rear region 23a and a second front region 23b. The second rear region 23a is connected to the first rear region 22a of the first reflecting surface 22. The second rear region 23a receives light reflected by the first rear region 22a. The second rear region 23a internally reflects the light reflected by the first rear region 22a forward.

The second front region 23b is connected to the front end of the second rear region 23a. The second front region 23b receives light reflected by the first front region 22b. The second front region 23b internally reflects the light reflected by the first front region 22b forward. The second front region 23b is provided, for example, in a state of extending forward from the front end of the second rear region 23a. The second front region 23b is smoothly connected to the second rear region 23a. The second front region 23b may be connected to the second rear region 23a in a manner that is not smooth. For example, a step may be provided between the second front region 23b and the second rear region 23a. The second front region 23b is disposed below the light shielding portion 24 described later. The rear end of the second front region 23b is disposed on the virtual straight line VL1 extending backward from the light shielding portion 24 of the light collecting pattern forming surface 23M or below the virtual straight line VL1. The front end of the second front region 23b is disposed on a virtual line VL2 that passes through the front end of the first front region 22b and is parallel to the optical axis AX of the light source 10. That is, in a cross-sectional view, the second front region 23b is disposed between the intersection of the light-collecting pattern forming surface 23M and the virtual line VL1 and the intersection of the light-collecting pattern forming surface 23M and the virtual line VL2. By setting the second front region 23b within this range, the light reflected by the first front region 22b can be reliably reflected forward by the second front region 23b.

[Light-shielding part]
The light shielding portion 24 shields a part of the light that is internally reflected by the second rear region 23a of the second reflecting surface 23. The light shielding portion 24 is provided at a corner 20g formed by a connection surface 26 and a re-entering surface 27 described later. The corner 20g is concave when the vehicle light guide 20 is viewed from the outside (below). The corner 20g extends linearly in the left-right direction. The light shielding portion 24 forms a cutoff line CL (see FIG. 6) of a low beam pattern P1 of a light distribution pattern PF described later at the corner 20g. The cutoff line CL includes a horizontal cutoff line and an oblique cutoff line. The corner 20g has a horizontal portion (not shown) for forming a horizontal cutoff line and an inclined surface portion (not shown) for forming an oblique cutoff line.

The light shielding portion 24 is provided in an area including the corner 20g. The light shielding portion 24 may, for example, refract or internally reflect the light that reaches the light shielding portion 24 in a direction different from the direction of the light output surface 28 to block light, or may provide a light absorbing layer on the portion of the connection surface 26 including the corner 20g that corresponds to the light shielding portion 24, and block light by absorbing the light with the light absorbing layer. The light that is internally reflected or refracted by the light shielding portion 24 is emitted to the outside of the vehicle light guide 20 and absorbed by an inner housing or the like that is disposed outside the vehicle light guide 20.

[Transmitting surface]
The transmitting surface 25 is folded back upward from the front end of the second front region 23b and is provided facing the second front region 23b. The transmitting surface 25 is, for example, planar and has a shape that is inclined upward from the rear to the front. The transmitting surface 25 and the second front region 23b are provided in a V-shape in cross section, as shown in Fig. 4 etc. The transmitting surface 25 transmits light reflected by the second front region 23b to the outside of the light guide and directs it forward.

The transmitting surface 25 transmits the light from the second reflecting surface 23 to the outside of the vehicle light guide 20 and emits it forward (see FIG. 5). The light that transmits from the transmitting surface 25 to the outside of the light guide and heads forward is incident on the re-entering surface 27 (described later) and is emitted from the exit surface 28 to form an overhead pattern P2 (described later) in front of the vehicle (see FIG. 6).

As shown in FIG. 2, for example, the transmission surface 25 is arranged so that it fits within the area through which the reflected light that is internally reflected by the light-collecting pattern forming surface 23M passes when viewed from below. In this embodiment, the transmission surface 25 is arranged so that it fits within an area AR that tapers forward from both lateral ends of the light-collecting pattern forming surface 23M toward the focal point P when viewed from below.

[Connection surface]
The connection surface 26 connects the second reflection surface 23 and the light shielding portion 24. The connection surface 26 is located on the lower side of the vehicle light guide 20 and is disposed along the horizontal plane. The connection surface 26 is provided flat from the light shielding portion 24 to the connection portion with the upper end portion of the transmission surface 25. Therefore, the connection surface 26 has an area capable of internal reflection over a wide range in the front-rear direction. An external light shielding portion 29 is provided on the connection surface 26.

The external light shielding portion 29 is configured such that a portion of the connection surface 26 protrudes downward. As shown in FIG. 2, the external light shielding portion 29 is arranged so as to be contained within the area AR through which light internally reflected by the light-collecting pattern forming surface 23M passes when viewed from the top-bottom direction. The external light shielding portion 29 blocks a portion of the light that passes from the transmission surface 25 to the outside of the light guide and travels forward. Specifically, the external light shielding portion 29 blocks the light that is irradiated to the area PA near the H-H line of the overhead pattern P2 (see FIG. 6).

The external light shielding portion 29 may, for example, shield light by refracting or internally reflecting light that reaches the external light shielding portion 29 in a direction different from the direction of the re-entry surface 27, or may shield light by arranging a light absorbing layer on the surface of the external light shielding portion 29 and absorbing the light with the light absorbing layer. Note that the light that is internally reflected or refracted by the external light shielding portion 29 is absorbed by an inner housing or the like that is arranged outside the vehicle light guide 20.

[Re-entrance surface]
The re-entry surface 27 is provided in a state of being bent downward with respect to the connection surface 26. The re-entry surface 27 is formed in a state of being inclined forward from the top to the bottom. The re-entry surface 27 re-enters the light that has been transmitted to the outside from the transmission surface 25. The light re-entering from the re-entry surface 27 proceeds from the lower side of the light-shielding portion 24 toward the exit surface 28.

[Exit surface]
The exit surface 28 emits the light that is internally reflected by the second reflecting surface 23 and is not blocked by the light blocking portion 24, and the light that is incident from the re-entering surface 27, and irradiates a light distribution pattern PF (see FIG. 6) in front of the vehicle. In this embodiment, the exit surface 28 is, for example, curved and has a focal point and an optical axis (not shown). Note that the exit surface 28 may be, for example, planar, and may be configured to have other optical elements arranged to irradiate the light emitted from the exit surface 28 in front of the vehicle. The focal point of the exit surface 28 is located in a position near the focal point P of the second reflecting surface 23. In this embodiment, the width of the exit surface 28 in the left-right direction may be narrower than the width of the second reflecting surface 23 in the left-right direction. In this case, the size of the exit surface 28 when viewed from the outside can be suppressed.

A light diffusion section such as a prism section may be formed on the upper surface 20h of the vehicle light guide 20. The light diffusion section diffuses the light that is internally reflected by the second reflecting surface 23. This makes it possible to prevent the light emitted from the upper surface 20h to the outside of the vehicle light guide 20 from becoming glare.

[motion]
Next, the operation of the vehicular lamp 100 configured as described above will be described. Fig. 6 is a diagram showing an example of a light distribution pattern projected onto a virtual screen in front of the vehicle. Fig. 6 shows a pattern corresponding to vehicles driving on the left side of the road. In Fig. 6, line V-V indicates a vertical line of the screen, and line H-H indicates horizontal lines on the left and right sides of the screen. In addition, the intersection of the vertical line and the horizontal line is assumed to be the reference position in the horizontal direction.

When the light source 10 of the vehicle lamp 100 is turned on, light is emitted from the light-emitting surface 11. This light is incident on the vehicle light guide 20 from the first surface 21a and the second surface 21b of the incident surface 21. The light incident from the first surface 21a travels toward the first reflecting surface 22. The light incident from the second surface 21b is internally reflected by the first reflecting surface 22 toward the second reflecting surface 23.

As shown in FIG. 5, for example, light L1 reflected by the first rear region 22a of the first reflecting surface 22 reaches the second rear region 23a of the second reflecting surface 23. The light L1 that reaches the second rear region 23a is internally reflected by the second rear region 23a and reaches the connecting surface 26. In this embodiment, the connecting surface 26 is formed flat over the entire front-rear direction from the light-shielding portion 24 to the transmitting surface 25. Therefore, the light L1 that reaches the connecting surface 26 is internally reflected toward the front of the vehicle without waste. The light L1 that is internally reflected by the connecting surface 26 passes above the light-shielding portion 24 and reaches the exit surface 28. The light L1 that reaches the exit surface is emitted from the exit surface 28 toward the front of the vehicle.

In addition, the light L2 and L3 reflected by the first front region 22b of the first reflecting surface 22 reaches the second front region 23b of the second reflecting surface 23. The light L2 and L3 that reaches the second front region 23b is internally reflected by the second front region 23b and reaches the transmission surface 25. In this embodiment, the transmission surface 25 is arranged facing the second front region 23b in a state where it is folded back upward from the front end of the second front region 23b. Therefore, the light L2 and L3 reflected by the second front region 23b is transmitted from the transmission surface 25 to the outside of the light guide without waste. The light L2 and L3 transmitted to the outside of the light guide by the transmission surface 25 proceeds forward outside the light guide, passes under the light shielding portion 24, and re-enters the inside of the vehicle light guide 20 from the re-entry surface 27. The re-entered light L2 and L3 reaches the exit surface 28 and is emitted from the exit surface 28 to the front of the vehicle. Note that, in FIG. 5, an example is shown in which light L2 and light L3 intersect outside the light guide, but this is not limited to this case.

The light L1, L2, and L3 emitted from the exit surface 28 are irradiated in front of the vehicle as a light distribution pattern PF, as shown in FIG. 6. Specifically, the light L1 that passes above the light-shielding portion 24 and reaches the exit surface 28 forms a light-collecting pattern P1a including a cutoff line CL in the low beam pattern P1. Note that FIG. 6 illustrates an example in which the oblique cutoff line CLa of the cutoff line CL is formed so as to tilt downward toward the right, but this is not limited thereto, and a similar explanation is also possible in the case where the oblique cutoff line CLa tilts downward toward the left.

Although not shown, the diffused light reflected by the diffusion pattern forming surface 23N of the second reflecting surface 23 partly passes over the connecting surface 26 and partly is reflected by the connecting surface 26, passes above the light blocking portion 24, and reaches the exit surface 28. The diffused light emitted from the exit surface 28 forms the diffusion pattern P1b of the low beam pattern P1.

In addition, the light L2 and L3 emitted to the outside of the light guide by the transmission surface 25, passing under the light shielding portion 24, and reaching the emission surface 28 form the overhead pattern P2. By using a portion of the light reflected by the first front region 22b of the first reflection surface 22 as the overhead pattern P2 without waste, the light utilization efficiency can be improved.

[Vehicle lighting unit]
FIG. 7 is a diagram showing an example of a vehicle lighting unit 200 according to the present embodiment. FIG. 7 shows an example seen from the front in a state mounted on a vehicle. The vehicle lighting unit 200 shown in FIG. 7 has a housing 201, an outer lens 202, a light source 10, and a plurality of vehicle light guides 20. The vehicle lighting unit 200 is configured such that, for example, two vehicle light guides 20 are arranged in a lamp chamber surrounded by the housing 201 and the outer lens 202. The vehicle light guides 20 arranged in the lamp chamber may be one or three or more. In addition, the vehicle light guides 20 are not limited to being arranged in the left-right direction when viewed from the front, but may be arranged in the up-down direction, may be arranged in an oblique direction, or may be arranged in a combination of two or more of the left-right direction, the up-down direction, and the oblique direction. The number and arrangement of the light sources 10 may be different for different vehicle light guides 20.

For example, one vehicle light guide 20 may be configured for light collection with the light source 10 arranged to make light incident on the central incident surface 21M, and another vehicle light guide 20 may be configured for diffusion with the light source 10 arranged to make light incident on the outer incident surface 21N. Also, at least one of the light collection configuration and the diffusion configuration may be provided in multiple locations. In this case, the vehicle lamp unit 200 as a whole can form a light collection pattern P1a and a diffusion pattern P1b in front of the vehicle while suppressing heat generation from each vehicle light guide 20.

As described above, the vehicle light guide 20 according to this embodiment has an incident surface 21 on which light from the light source 10 is incident, a first front region 22b arranged forward of the light source 10, a first reflective surface 22 that internally reflects the light incident from the incident surface 21 to form approximately parallel light, a second front region 23b at the front end into which the light reflected by the first front region 22b is incident, a second reflective surface 23 that internally reflects the light reflected by the first reflective surface 22 forward, and a portion of the light reflected by the second reflective surface 23. It is equipped with a light shielding section 24 that blocks light, a transmission surface 25 that is folded back from the front end of the second front region 23b upward in the vertical direction when mounted on the vehicle and transmits the light reflected by the second front region 23b to the outside of the light guide and directs it forward, a re-entry surface 27 that is disposed in front of the transmission surface 25 and below the light shielding section 24 and re-enters the light that has transmitted from the transmission surface 25 to the outside of the light guide, and an exit surface 28 that exits the light that has been internally reflected by the second reflection surface 23 and the light that has entered from the re-entry surface 27.

According to this configuration, the main pattern (low beam pattern P1) is formed by the light reflected by the second reflecting surface 23, passing through the light shielding portion 24 or above the light shielding portion 24, and exiting from the exiting surface 28. In addition, a separate pattern (overhead pattern P2) is formed on the upper front side of the vehicle by the light emitted to the outside of the light guide by the transmitting surface 25, passing under the light shielding portion 24, re-entering from the re-entering surface 27, and exiting from the exiting surface 28. In this way, by using a part of the light incident from the incident surface 21 as light that forms a pattern (overhead pattern P2) different from the main pattern (low beam pattern P1), the light utilization efficiency can be improved. At this time, the light that reaches the first front region 22b of the first reflecting surface 22 reaches the second front region 23b of the second reflecting surface 23 and is transmitted to the transmitting surface 25 folded back in front of the second front region 23b, so that the light that reaches the first front region 22b can be used efficiently without waste.

In the above vehicle light guide 20, the first reflecting surface 22 has a first rear region 22a arranged rearward from the light source 10, and the second reflecting surface 23 has a second rear region 23a arranged rearward from the second front region 23b, and further includes a connecting surface 26 that extends forward from the upper end of the transmitting surface 25, connects the transmitting surface 25 and the light blocking portion 24, and internally reflects a portion of the light internally reflected by the second rear region 23a. This ensures that the connecting surface 26, which internally reflects a portion of the light internally reflected by the second rear region 23a, has a wide area in the front-rear direction that can be internally reflected.

In the vehicle light guide 20, the second front region 23b is disposed below the light blocking portion 24. This allows the second front region 23b to be secured wide, so that the light reaching the first front region 22b can be used efficiently without waste.

In the above-mentioned vehicle light guide 20, the connection surface 26 may have an external light shielding portion 29 that is arranged in a protruding state toward the outside of the light guide and shields a portion of the light that is transmitted from the transmission surface 25 to the outside of the light guide. In this configuration, the light irradiated to a portion of the area of the pattern (overhead pattern P2) formed on the upper front part of the vehicle is dimmed. This makes it possible to, for example, suppress dazzling the preceding vehicle or the oncoming vehicle, and suppress the occurrence of glare light.

In the above-mentioned vehicle light guide 20, the exit surface 28 irradiates the light distribution pattern PF in front of the vehicle. In this configuration, the vehicle light guide 20, which is an integrated unit from the entrance surface 21 to the exit surface 28, can effectively utilize light while forming the light distribution pattern PF in front of the vehicle.

In the above-mentioned vehicle light guide 20, the light distribution pattern includes a main pattern formed by light internally reflected by the second rear region 23a of the second reflecting surface 23, and an upper pattern formed by light internally reflected by the second front region 23b of the second reflecting surface 23 and irradiated above the main pattern. This allows the light that reaches the first front region 22b to be used efficiently without waste as the upper pattern.

The vehicle lighting unit according to the present invention includes a light source 10 and a plurality of the above-mentioned vehicle light guides 20 that guide and emit light from the light source 10. With this configuration, the vehicle lighting unit 200 as a whole can obtain a light distribution pattern PF that combines the irradiation patterns of the plurality of vehicle light guides 20.

The technical scope of the present invention is not limited to the above embodiment, and appropriate modifications can be made without departing from the spirit of the present invention. In the above embodiment, the configuration of the vehicle lamp 100 mounted on a vehicle traveling on a left-hand traffic road was described as an example, but the present invention is not limited to this, and a similar description can be made when a vehicle headlamp is mounted on a vehicle traveling on a right-hand traffic road.

In the above embodiment, a low beam pattern has been described as an example of the light distribution pattern PF, but this is not limited thereto, and other patterns such as a high beam pattern may also be used. In addition, in a vehicle lighting unit 200 in which multiple vehicle light guides 20 are provided, vehicle light guides 20 that form different types of patterns may be provided.

AR, PA...area, AX...optical axis, CL...cutoff line, CLa...oblique cutoff line, L1, L2, L3...light, LMa, LMb, LNa, LNb, LNc, LNd, VL1, VL2...virtual line, P...focus, P1...low beam pattern, P2...overhead pattern, P1a...concentration pattern, P1b...diffusion pattern, PF...light distribution pattern, S...virtual plane, 10...light source, 11...light emitting surface, 20...vehicle light guide, 20g...corner, 20h...upper surface, 21...incident surface, 21M...central incident surface, 21N...outer incident surface, 21a...first surface, 21b...second surface, 22...first reflecting surface, 22M...reflecting surface for light-collecting pattern, 22N...reflecting surface for diffusion pattern, 22a...first rear region, 22b...first front region, 23...second reflecting surface, 23M...light-collecting pattern forming surface, 23N...diffusion pattern forming surface, 23a...second rear region, 23b...second front region, 24...light shielding portion, 25...transmitting surface, 26...connecting surface, 27...re-entrance surface, 28...exiting surface, 29...external light shielding portion, 100...vehicle lamp, 200...vehicle lamp unit, 201...housing, 202...outer lens

Claims (7)

an incident surface on which light from a light source is incident;
a first reflecting surface that has a first front region that is disposed forward in a front-rear direction relative to the light source when the light source is mounted on the vehicle, and that internally reflects the light incident from the incident surface to form substantially parallel light;
a second reflecting surface having a second front region at a front end portion into which the light reflected by the first front region is incident, the second reflecting surface internally reflecting the light reflected by the first reflecting surface toward a front;
a light blocking portion that blocks a portion of the light reflected by the second reflecting surface;
a transmission surface that is provided in a state where it is folded back upward from a front end portion of the second reflection surface in a vertical direction in a state where the light is mounted on the vehicle, and transmits the light reflected in the second front region to an outside of the light guide and directs the light forward;
a re-entry surface disposed in front of the transmission surface and below the light blocking portion, the re-entry surface being adapted to re-enter the light transmitted from the transmission surface to the outside of the light guide;
an exit surface that exits the light that has been internally reflected by the second reflecting surface and the light that has entered from the re-entering surface. The first reflecting surface has a first rear region disposed rearward with respect to the light source,
the second reflecting surface has a second rear region disposed rearward of the second front region,
2. The vehicle light guide according to claim 1, further comprising a connecting surface extending forward from an upper end of the transmitting surface, connecting the transmitting surface and the light blocking portion, and internally reflecting a portion of the light internally reflected in the second rear region. The vehicle light guide according to claim 1 or 2, wherein the second front region is disposed below the light blocking portion. The vehicle light guide according to claim 2 , wherein the connection surface has an external light shielding portion arranged to protrude to an outside of the light guide and to shield a part of the light transmitted from the transmission surface to the outside of the light guide. The vehicle light guide according to claim 1 , wherein the light exit surface projects a light distribution pattern ahead of the vehicle. The first reflecting surface has a first rear region disposed rearward with respect to the light source,
the second reflecting surface has a second rear region disposed rearward of the second front region,
6. The vehicle light guide according to claim 5, wherein the light distribution pattern includes a main pattern formed by the light internally reflected at the second rear region of the second reflecting surface, and an upper pattern formed by the light internally reflected at the second front region of the second reflecting surface and irradiated above the main pattern. Equipped with a light source,
A vehicle lamp unit comprising a plurality of vehicle light guides according to claim 1 , each of which guides and emits light from the light source.

Images