JP4926642B2 - Lighting fixtures for vehicles - Google Patents

Description

  The present invention relates to a vehicular illumination lamp configured to form a predetermined light distribution pattern by a light source and a lens disposed on the front side of the lamp.

  Conventionally, in a lamp unit of a cornering lamp or a headlamp, light from a light source disposed on an optical axis extending in the front-rear direction of the lamp is deflected and emitted toward the front of the lamp by a lens disposed on the front side of the lamp. Thus, there is known one configured to form a predetermined light distribution pattern.

  For example, “Patent Document 1” describes a configuration example as a cornering lamp, and “Patent Document 2” and “Patent Document 3” describe a configuration example as a lamp unit of a headlamp. .

  “Patent Document 4” describes a projector-type lamp unit in a headlamp in which the surface shape of the projection lens is set to a shape different from that of a normal projection lens.

JP-A-2005-141918 JP-A-2005-44683 Japanese Utility Model Publication No. 4-21005 JP 2005-183090 A

  Since vehicle illumination lamps such as cornering lamps and headlamp lamp units are often arranged along the shape of the vehicle body, it is also possible to form the lens with a surface shape along the shape of the vehicle. From the viewpoint of increasing the degree of freedom of the vehicle and improving the design of the vehicle.

  However, in the vehicular illumination lamp described in the above-mentioned “Patent Document 2” and “Patent Document 3”, a plano-convex lens is used as the lens, and the vehicular illumination lamp described in “Patent Document 1” is used. In the illuminating lamp, a lens having a front surface formed of an elliptical spherical surface is used as the lens thereof, and none of the lenses follows the shape of the vehicle body. For this reason, there exists a problem that it is inadequate in raising the freedom degree of a lamp layout or a vehicle design.

  The projection lens of the lamp unit described in “Patent Document 4” has a surface shape different from that of a normal projection lens. However, even in this case, the surface shape has a certain degree of regularity. The surface shape does not correspond to the vehicle body shape.

  Further, even if the front surface of the lens is configured with a free-form surface along the shape of the vehicle body, a desired light distribution pattern cannot be formed with high accuracy.

  The present invention has been made in view of such circumstances, and in a vehicular illumination lamp configured to form a predetermined light distribution pattern by a light source and a lens disposed on the front side of the lamp, Even if it is a case where the front side surface of a lens comprises a free-form surface, it aims at providing the illumination lamp for vehicles which can form a desired light distribution pattern with sufficient accuracy.

  In the present invention, the front surface of the lens is configured with a free curved surface, and the rear surface thereof is configured with a predetermined free curved surface so as to achieve the above object.

That is, the vehicular illumination lamp according to the first invention of the present application is:
A light source disposed on an optical axis extending in the front-rear direction of the lamp, and a lens disposed on the front side of the lamp of the light source and deflecting and emitting light from the light source toward the front of the lamp. In a vehicular lighting fixture configured to form a pattern,
The front surface of the lens is composed of a first free-form surface,
The emission angle of the light emitted from the front surface with respect to the optical axis is set as a target emission angle for each point on the front surface,
The rear surface of the lens is composed of a second free-form surface formed by continuously forming a surface element having an inclination angle for realizing light emission at a target emission angle set for each point. And
The target emission angle in the vertical direction is maintained at a constant value even if the vertical opening angle is increased above the optical axis, while the vertical opening angle is increased below the optical axis. Is set to be larger according to
Moreover, the vehicular illumination lamp according to the second invention of the present application is:
A light source disposed on an optical axis extending in the front-rear direction of the lamp, and a lens disposed on the front side of the lamp of the light source and deflecting and emitting light from the light source toward the front of the lamp. In a vehicular lighting fixture configured to form a pattern,
The front surface of the lens is composed of a first free-form surface,
The emission angle of the light emitted from the front surface with respect to the optical axis is set as a target emission angle for each point on the front surface,
The rear surface of the lens is composed of a second free-form surface formed by continuously forming a surface element having an inclination angle for realizing light emission at a target emission angle set for each point. And
The target emission angle in the vertical direction is set so as to increase as the vertical opening angle increases on either side above and below the optical axis, and the light on the lower side of the optical axis. The change rate of the target emission angle is set to a value smaller than that on the upper side of the shaft .

  The type of the “vehicle illumination lamp” is not particularly limited, and, for example, a cornering lamp, a headlamp lamp unit, a fog lamp, or the like can be employed.

  The “lamp front-rear direction” may or may not coincide with the vehicle front-rear direction.

  The type of the “light source” is not particularly limited, and for example, a light emitting chip of a light emitting element such as a light emitting diode or a laser diode, a discharge light emitting part of a discharge bulb, a filament of a halogen bulb, etc. can be employed. Further, as the “light source”, in addition to such a primary light source, a secondary light source formed by converging light from the primary light source to a substantially single point by a reflector, a lens, or the like can be employed. .

  The specific shape of the “first free curved surface” is not particularly limited. For example, a curved surface formed flush with the surface of the vehicle body, or formed at equal intervals with respect to the curved surface. A curved surface or the like can be used.

  As shown in the above configuration, the vehicular illumination lamp according to the present invention directs light from a light source disposed on an optical axis extending in the front-rear direction of the lamp to the front of the lamp by a lens disposed on the front side of the lamp. The lens is configured to be deflected and emitted to form a predetermined light distribution pattern. The front surface of the lens is formed of a first free-form surface, and the optical axis of light emitted from the front surface. Is set as a target output angle for each point on the front surface, and the rear surface of the lens emits light at the target output angle set for each point. Since it is composed of a second free-form surface formed by continuously forming surface elements having an inclination angle for realizing, the following operational effects can be obtained.

  That is, since the front side surface of the lens is formed of the first free-form surface, it is possible to easily form the front side surface in a shape along the surface shape of the vehicle body.

  In addition, since the emission angle of the light emitted from the front surface of the lens with respect to the optical axis is set as the target emission angle for each point on the front surface, the shape of the desired light distribution pattern and its luminous intensity distribution Accordingly, the light distribution pattern can be formed with high accuracy by setting the target emission angle for each point.

  Furthermore, the rear surface of the lens is formed by continuously forming a surface element having an inclination angle for realizing light emission at a target emission angle set for each point on the front surface. Therefore, an optical path necessary for the light emission can be obtained without causing a step or the like on the rear surface.

  Specifically, the second free-form surface can be generated by the following procedure.

  That is, first, an appropriate point on the front surface of the lens (for example, a point located on the optical axis or a point located on the outer peripheral edge) is set as a reference point. Then, the light incident direction to the reference point in the lens necessary for emitting light from the reference point at the target emission angle is calculated using Snell's law.

  Next, a starting point for generating the second free-form surface is set at an appropriate position on the straight line extending in the light incident direction. And the first surface element which comprises a part of 2nd free-form surface is allocated to this starting point. At that time, the angle between the straight line extending in the light incident direction and the straight line connecting the light emission center of the light source and the starting point is calculated, and the inclination angle of the first surface element is obtained so that the refractive power corresponding to this angle can be obtained. Is calculated using Snell's law.

  Then, the calculation is performed on the point adjacent to the reference point on the front surface of the lens by the same procedure as that for the reference point, and the inclination angle of the surface element adjacent to the first surface element is calculated. . Thereafter, by repeating the same process and continuously forming a series of these surface elements, it is possible to generate a second free-form surface extending over the entire lens area.

  As described above, according to the present invention, in the vehicular illumination lamp configured to form a predetermined light distribution pattern with the light source and the lens disposed on the front side of the lamp, the front surface of the lens is a free-form surface. Even if configured, a desired light distribution pattern can be formed with high accuracy. As a result, the degree of freedom in lamp layout and vehicle design can be increased.

  In particular, in the lens of the vehicular illumination lamp according to the present invention, the front side surface and the rear side surface are both configured by free-form surfaces, so that no step or the like can be formed on the lens surface. Therefore, the appearance of the vehicular illumination lamp can be improved.

  In the above configuration, instead of configuring the front surface of the lens with the first free-form surface over the entire area, a central region located in the vicinity of the optical axis on the front surface is a general peripheral region surrounding the central region. And a third free-form surface formed substantially similar to the first free-form surface with respect to the position of the light source on the rear side, and the central region and the general peripheral region via an annular wall surface A connected configuration is also possible.

  By adopting such a configuration, the lens can be reduced in thickness and weight, and the light transmission efficiency from the light source can be increased by the reduced thickness.

  In particular, since the front side surface and the rear side surface of the lens of the vehicular illumination lamp according to the present invention are both free-form surfaces, it is ensured that the lens is made of a synthetic resin. In this case, if the thickness of the lens partly becomes extremely thick, sink marks are likely to occur, and it becomes difficult to ensure surface accuracy.

  In that respect, if the central region located near the optical axis on the front surface of the lens is displaced rearward from the general peripheral region, the thickness of the lens will become extremely thick partially. Can be prevented in advance, and this makes it easy to ensure surface accuracy. In addition, such a configuration can suppress an increase in temperature in the lens when the lamp is turned on, which is preferable for a lens made of synthetic resin having poor heat resistance.

  At this time, since the third free-form surface constituting the central region is formed in a shape substantially similar to the first free-form surface with reference to the light source, the emitted light from each point in the central region is converted into the lens. When the front side surface of the light beam is composed of the first free-form surface over the entire area, the light can travel in substantially the same direction as the light emitted from each point.

  Further, if the inclination angle of the annular wall surface in the plane including the optical axis is set to substantially the same value as the emission angle of the outgoing light from the outer peripheral edge of the central region with respect to the optical axis, a part of the outgoing light from the central region However, it is possible to prevent the incident light from entering the lens from the annular wall surface and exiting from the general peripheral region in an unexpected direction. And it can suppress effectively that the light control function of a lens will be impaired since the annular wall surface was formed.

  In the above configuration, if the light source of the vehicular illumination lamp is configured by a light emitting chip in a light emitting element such as a light emitting diode and direct light from the light emitting chip is incident on the lens, the vehicular illumination lamp can be made compact. Can be configured.

  In the above configuration, the “light source” has a reflecting surface made of a spheroid having a light beam from a primary light source arranged behind the position of the light source as a first focal point and the light emission center of the primary light source. If a secondary light source formed by reflecting with a reflector and converging on the second focal point of the spheroid surface is adopted, the luminous flux utilization rate for the light emitted from the primary light source can be increased and the primary The luminance unevenness of the light source can be reduced as compared with the light source. The type of the “primary light source” is not particularly limited, and the central axis of the “spheroid” is within the angle range in which light from the secondary light source can enter the lens. The axis may coincide with the axis or may not coincide with the axis.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, a first embodiment of the present invention will be described.

  FIG. 1 is a plan sectional view showing a vehicular illumination lamp 10 according to the present embodiment. 2 is a cross-sectional view taken along the line II-II in FIG. 1, and FIG. 3 is a view taken in the direction of the arrow III in FIG.

  As shown in these drawings, the vehicular illumination lamp 10 according to the present embodiment is a cornering lamp mounted on the left front end corner portion of the vehicle body 2 and is tilted to the left when the vehicle turns to the left. The front road surface is irradiated.

  This vehicular illumination lamp 10 is disposed on an optical axis Ax extending in a direction inclined by a predetermined angle ν (specifically, ν = 50 °) outward in the vehicle width direction with respect to an axis Ax0 extending in the vehicle longitudinal direction. A light emitting diode 12 and a lens 14 that is disposed on the front side of the lamp of the light emitting diode 12 (that is, on the front side in the optical axis Ax direction) and deflects and emits the light from the light emitting diode 12 toward the front of the lamp. Yes.

  The light emitting diode 12 is a white light emitting diode in which a square light emitting chip 12a having a size of about 0.3 to 3 mm square is sealed with a substantially hemispherical resin mold 12b, and the light emitting chip 12a has an optical axis Ax. It is fixedly supported by a metal support plate 16 in a state where it is arranged toward the front side of the lamp. The support plate 16 is positioned and fixed to the rear surface of the rear vertical surface portion 18a of the substantially mortar-shaped holder 18 that expands toward the front side of the lamp. At this time, a circular small hole 18c slightly larger than the outer diameter of the resin mold 12b is formed on the rear vertical surface portion 18a on the optical axis Ax, and the resin mold 12b is moved forward of the lamp from the small hole 18c. It is designed to be exposed to the side.

  The front surface 14a of the lens 14 is configured by a first free curved surface extending substantially flush with the surface of the vehicle body 2, and the rear surface 14b of the lens 14 is a second free surface corresponding to the first free curved surface. The free-form surface (this will be described later). The lens 14 is fixedly supported by the holder 18 with the outer peripheral edge of the rear surface 14b abutting against the front end surface 18b of the holder 18.

  FIG. 4 is a perspective view of a horizontally long light distribution pattern PC formed on a virtual vertical screen disposed at a position 25 m ahead of the vehicle by light emitted forward from the vehicular illumination lamp 10 according to the present embodiment. FIG.

  This horizontally long light distribution pattern PC is formed on the left side of the VV line, which is a vertical line passing through HV, which is a vanishing point in the vehicle front direction of the axis Ax0 extending in the vehicle front-rear direction, and its upper edge is HV Is located slightly below the HH line, which is a horizontal line passing through.

  At this time, the horizontally long light distribution pattern PC is formed over the range from the vicinity of the VV line to about 100 ° to the left side with the direction of about 50 ° on the left side of the VV line as the center. The hot zone HZ, which is a region, is formed in a horizontally long shape at a position that is approximately the center in the left-right direction of the horizontally long light distribution pattern PC and near the upper edge.

  In order to form such a horizontally long light distribution pattern PC with high accuracy, in this embodiment, a target emission angle is set for each point on the front surface 14a of the lens 14, and the rear surface 14b thereof. Is set to a curved surface shape for realizing light emission at the target emission angle.

  The shape of the second free-form surface is set in the following procedure.

  That is, first, as shown in FIGS. 1 and 2, the emission angle of the light emitted from the lens 14 with respect to the optical axis Ax is set as a target emission angle for each point on the front surface 14a. At this time, the target emission angle is set as a horizontal target emission angle α and a vertical target emission angle β by dividing the target emission angle into a horizontal component and a vertical component.

  Specifically, as shown in FIG. 1, a horizontal component of an angle formed by a straight line L0 connecting the point P on the front surface 14a and the light emission center O of the light emitting chip 12a with the optical axis Ax is defined as a horizontal opening angle θH. The horizontal target emission angle α is set in correspondence with the horizontal opening angle θH, while the straight line connecting the point Q on the front surface 14a and the light emission center O of the light emitting chip 12a as shown in FIG. The vertical component of the angle formed by L0 and the optical axis Ax is the vertical opening angle θV, and the vertical target emission angle β is set corresponding to the vertical opening angle θV.

  At that time, the horizontal target emission angle α is set to a value corresponding to the horizontal diffusion angle and the luminous intensity distribution of the horizontally long light distribution pattern PC. That is, as shown in the graph of FIG. 5A, as the horizontal opening angle θH increases, the target emission angle α is increased in a substantially direct relationship with this. At this time, the horizontally long light distribution pattern PC is such that the portion located on the left side of the portion on the right side with respect to the direction of the optical axis Ax (that is, the direction about 50 ° on the left side of the VV line) is in the horizontal direction. Since the diffusion angle is slightly larger, the change rate of the target emission angle α is set so that the target emission angle α in the left direction is slightly larger than the target emission angle α in the right direction. .

  On the other hand, the target emission angle β in the vertical direction is set to a value corresponding to the vertical diffusion angle and the luminous intensity distribution of the horizontally long light distribution pattern PC. That is, as shown in the graph of FIG. 5B, above the optical axis Ax, the target emission angle β is maintained at a small negative constant value even when the vertical opening angle θV increases, The emitted light from the lens 14 is set to be a downward parallel light. Further, as shown in the graph, on the lower side than the optical axis Ax, as the vertical opening angle θV is increased, the target emission angle β is increased in a substantially direct relationship with this. However, the rate of change of the target emission angle β is set to a value that is considerably smaller than the rate of change of the target emission angle α so that the light emitted from the lens 14 is slightly diffused downward. .

  Next, a second free-form surface constituting the rear side surface 14b of the lens 14 is generated. The generation of the second free-form surface is performed by continuously forming a surface element having an inclination angle for realizing light emission at a target emission angle set for each point on the front surface 14a. .

  FIG. 6 is a diagram showing a procedure for generating a free curve C2 constituting the horizontal sectional shape of the second free curved surface.

  First, as shown in FIG. 2A, the lens necessary for emitting light at a target emission angle α from a point P on a free curve C1 constituting the horizontal cross-sectional shape of the front surface 14a of the lens 14. The light incident direction on the point P within 14 is calculated.

  At that time, since the front surface 14a of the lens 14 is formed of a first free-form surface along the surface shape of the vehicle body 2, the direction of the normal line N1 of the free curve C1 at the point P is known. Therefore, the light incident direction (direction indicated by the straight line L2) to the point P corresponding to the light emission direction from the point P (direction indicated by the straight line L1) is calculated using Snell's law.

  Next, as shown in FIG. 6B, the point R where the free curve C2 in the process of intersecting the straight line L2 and the light emission center O of the light emitting chip 12a are connected by a straight line L3, and this straight line L3 is connected to the straight line L2. The formed angle δ is calculated.

  The free curve C2 is generated starting from a point S on the optical axis Ax as described later. For convenience of explanation, it is assumed that the free curve C2 has already been generated up to the position of the point R.

  Next, the line element E of the free curve C2 is assigned to the point R. At this time, the direction of the normal N2 of the line element E is calculated using Snell's law so that the refractive power corresponding to the angle δ can be obtained in the line element E, and the inclination angle of the line element E is also calculated simultaneously. To do. Thereby, the light emitted from the light emission center O of the light emitting chip 12a is emitted from the lens 14 forward of the lamp along the optical path of the straight line L3 to the straight line L2 to the straight line L1.

  Then, on the free curve C1, the calculation is performed on the point adjacent to the right side of the point P (that is, the side away from the optical axis Ax) in the same procedure as in the case of the point P, and the line adjacent to the right side of the line element E The prime tilt angle is calculated. Thereafter, the same processing is repeated to continuously form these series of line elements, thereby generating a portion located on the right side of the optical axis Ax in the free curve C2.

  The free curve C2 is generated by setting a point P0 located on the optical axis Ax on the free curve C1 as a reference point. At this time, the starting point S when generating the free curve C2 is set on the optical axis Ax as a point corresponding to the reference point P0, and the first line element assigned to the starting point S is the optical axis Ax at the starting point S. It will be orthogonal. This is because the target emission angle α at the reference point P0 is set to α = 0 ° (see FIG. 1), whereby the normal line N1 at the reference point P0 of the free curve C1 coincides with the optical axis Ax, and the straight line This is because the optical paths of L3 to L2 to L1 also coincide with the optical axis Ax.

  The position in the front-rear direction on the optical axis Ax of the starting point S is separated from the reference point P0 to such an extent that a second free-form surface can be generated over the entire rear surface 14b of the lens 14. Is set as close as possible to the reference point P0 so as not to become unnecessarily thick.

  The portion located on the left side of the optical axis Ax in the free curve C2 is also generated in the same procedure starting from the point S on the optical axis Ax.

  Then, the second free curve C2 is generated not only on the plane including the optical axis Ax but also on each of a plurality of planes parallel to the plane located on both upper and lower sides of the plane by the same procedure as that for generating the free curve C2. A free curve that forms the horizontal cross-sectional shape of the curved surface is generated.

  The free curve that forms the vertical cross-sectional shape of the second free-form surface that forms the rear surface 14b of the lens 14 is also generated in the same procedure as the free-curve C2 generation procedure. As the envelopes of the plurality of free curves constituting the horizontal sectional shape and the plurality of free curves constituting the vertical sectional shape (that is, the line elements and the vertical sectional shape of each of the plurality of free curves constituting the horizontal sectional shape) The second free-form surface is generated by continuously forming a plurality of surface elements arranged in a matrix in combination with each of the line elements of the plurality of free-form curves constituting the s.

  As described above in detail, the vehicular illumination lamp 10 according to the present embodiment uses the light from the light emitting diode 12 disposed on the optical axis Ax extending in the front-rear direction of the lamp to the lens 14 disposed on the front side of the lamp. Is formed so as to be deflected and emitted toward the front of the lamp to form a horizontally long light distribution pattern PC, but the front side surface 14a of the lens 14 is formed of a first free-form surface. It is possible to easily form the side surface 14a in a shape along the surface shape of the vehicle body 2 (in this embodiment, a curved surface shape extending substantially flush with the surface of the vehicle body 2).

  Further, in the vehicular illumination lamp 10 according to the present embodiment, the emission angle of the emitted light from the front surface 14a of the lens 14 with respect to the optical axis Ax depends on the shape of the horizontally long light distribution pattern PC and the light intensity distribution thereof. Since the target emission angle is set for each point on the front surface 14a, the horizontally long light distribution pattern PC can be formed with high accuracy.

  Furthermore, the vehicular illumination lamp 10 according to the present embodiment is configured so that the rear surface 14b of the lens 14 realizes light emission at a target emission angle set for each point on the front surface 14a. Since it is composed of a second free-form surface formed by continuously forming surface elements having an inclination angle, it is possible to obtain an optical path necessary for the light emission without causing a step or the like on the rear surface 14b. it can.

  As described above, the vehicular illumination lamp 10 according to the present embodiment can form a desired laterally long light distribution pattern PC even though the front surface 14a of the lens 14 is configured as a free-form surface. As a result, the degree of freedom in lamp layout and vehicle design can be increased.

  In addition, the front side surface 14a and the rear side surface 14b of the lens 14 of the vehicular illumination lamp 10 according to the present embodiment are both free-form surfaces, so that no step or the like is formed on the surface of the lens 14. Therefore, the appearance of the vehicular illumination lamp 10 can be improved.

  In addition, the vehicular illumination lamp 10 according to the present embodiment is configured such that the light source is composed of the light emitting chip 12 a of the light emitting diode 12, and the direct light from the light emitting chip 12 a is incident on the lens 14. Therefore, this vehicular illumination lamp 10 can be configured compactly.

  At that time, the light emitting diode 12 is configured such that only the substantially hemispherical resin mold 12b for sealing the light emitting chip 12a is exposed to the front side of the lamp from the small hole 18c formed in the rear vertical surface portion 18a of the holder 18. Since it is arranged, the design in the lamp chamber that can be enlarged through the lens 14 can be seen well.

  Furthermore, in the present embodiment, the upper half of the lens 14 is configured to emit light from the light emitting diode 12 as parallel light in the vertical direction, and the lower half of the lens 14 emits light from the light emitting diode 12. Since it is configured to emit light that diffuses downward in the vertical direction, the horizontally long light distribution pattern PC can be formed so that the vicinity of the upper end is brighter and gradually becomes darker toward the lower end. As a result, it is possible to irradiate the front surface of the lamp with a substantially uniform brightness from the short-distance region to the long-distance region, and it is possible to further improve the visibility of the road surface ahead in the vehicle traveling direction when the vehicle is turning.

  Next, a second embodiment of the present invention will be described.

FIG. 7 is a front view showing the vehicular illumination lamp 110 according to the present embodiment. FIG. 8 shows the VIII-VIII in FIG.
FIG. 9 is a sectional view taken along line IX-IX in FIG.

  As shown in these drawings, the vehicular illumination lamp 110 according to the present embodiment is a lamp unit incorporated as a part of a headlamp mounted on the left front end corner portion of the vehicle body, and has a high beam light distribution pattern. Light irradiation for forming is performed. The headlamp has a transparent translucent cover 102 that extends substantially flush with the surface of the vehicle body. The vehicular illumination lamp 110 includes a translucent cover 102 and a lamp body (not shown). Is to be housed.

  The vehicle illumination lamp 110 includes a light source bulb 112 disposed on an optical axis Ax extending in the vehicle front-rear direction, a reflector 116 that reflects light from the light source bulb 112 forward and toward the optical axis Ax, A lens 114 disposed in front of the reflector 116 and a holder 118 for connecting the lens 114 and the reflector 116 are provided.

  The light source bulb 112 is a discharge bulb such as a metal halide bulb using the discharge light emitting portion 112a as a light source, and is inserted from the rear side into the rear top opening portion 116b of the reflector 116. The discharge light emitting portion 112a has an optical axis. The line segment light source extends along the optical axis Ax on Ax.

  The reflector 116 has a reflecting surface 116a formed of a spheroid having the optical axis Ax as a central axis. At this time, the spheroidal surface constituting the reflecting surface 116a has the first focal point F1 positioned at the light emission center of the discharge light emitting unit 112a, and the second focal point F2 is located in front of the first focal point F1. The position is set. And this reflector 116 forms the secondary light source by reflecting the light from the discharge light emission part 112a as a primary light source toward the optical axis Ax toward the front and converging it at the position of the second focal point F2, The light from the secondary light source is incident on the lens 114 as divergent light from the second focal point F2.

  The front surface 114a of the lens 114 is formed of a first free-form surface that extends substantially equidistantly from the translucent cover 102 in the vicinity of the rear of the translucent cover 102, and the rear surface 114b of the lens 114 is The second free-form surface (which will be described later) corresponding to the first free-form surface.

  The lens 114 is fixedly supported by the holder 118 in a state where the vicinity of the outer peripheral edge of the rear surface 114 b is in contact with the front end surface of the holder 118. An annular flange portion 114 c for positioning the lens 114 on the holder 118 is formed in the vicinity of the outer peripheral edge of the rear surface 114 b of the lens 114.

  The holder 118 is a substantially cylindrical member disposed between the lens 114 and the reflector 116, and is fixedly supported by the reflector 116 at the rear end thereof, whereby the positional relationship between the lens 114 and the reflector 116 is achieved. It is designed to position with.

  FIG. 10 is a perspective view of a high beam light distribution pattern PH formed on a virtual vertical screen disposed at a position 25 m ahead of the vehicle by light emitted forward from the vehicular illumination lamp 110 according to the present embodiment. FIG.

  The high-beam light distribution pattern PH is formed as a light distribution pattern that greatly expands in the left-right direction around HV, and the hot zone HZ is formed in a slightly horizontally long shape in the vicinity of HV.

  In order to form such a high beam light distribution pattern PH with high accuracy, in the present embodiment, a target emission angle is set for each point on the front surface 114a of the lens 114, and the rear surface thereof. The second free-form surface constituting 114b is set to a curved surface shape for realizing light emission at the target emission angle.

  The shape of the second free-form surface is set in the following procedure.

  That is, first, as shown in FIGS. 8 and 9, the emission angle of the light emitted from the lens 114 with respect to the optical axis Ax is set as a target emission angle for each point on the front surface 114a. At this time, the target emission angle is set as a horizontal target emission angle α and a vertical target emission angle β by dividing the target emission angle into a horizontal component and a vertical component.

  Specifically, as shown in FIG. 8, the horizontal component of the angle formed by the straight line L0 connecting the point P on the front surface 114a and the second focal point F2 serving as the light emission center of the secondary light source with the optical axis Ax is shown. A horizontal opening angle θH is set, and a target outgoing angle α in the horizontal direction is set in correspondence with the horizontal opening angle θH. On the other hand, as shown in FIG. 9, a point Q on the front surface 114a and the second focal point F2 The vertical component of the angle formed by the straight line L0 connecting with the optical axis Ax is the vertical opening angle θV, and the vertical target emission angle β is set corresponding to the vertical opening angle θV.

  At that time, the horizontal target emission angle α is set to a value corresponding to the horizontal diffusion angle and luminous intensity distribution of the high beam light distribution pattern PH. That is, as shown in the graph of FIG. 11A, the target emission angle α is increased as the horizontal opening angle θH is increased. At this time, the target emission angle α changes with a change rate of about the square of the change rate of the horizontal opening angle θH, thereby making the hot zone HZ formed in the vicinity of HV sufficiently bright.

  On the other hand, the target emission angle β in the vertical direction is set to a value corresponding to the vertical diffusion angle and luminous intensity distribution of the high beam light distribution pattern PH. That is, as shown in the graph of FIG. 11B, the target emission angle β is increased as the vertical opening angle θV is increased. At this time, the target output angle β is changed with a change rate of about the square of the change rate of the vertical opening angle θV, and the change rate of the target output angle β is compared with the change rate of the target output angle α. And a fairly small value. Thereby, formation of the horizontally long hot zone HZ is realized. Further, on the lower side of the optical axis Ax, the rate of change of the target emission angle β is set to be slightly smaller than that on the upper side thereof, whereby the position of the lower edge of the high beam light distribution pattern PH is set as shown in FIG. In FIG. 2, the position is displaced slightly toward the HH line from the position indicated by the two-dot chain line. And thereby, it prevents that the short distance area | region of a vehicle front road surface becomes bright too much, and is trying to raise the distance visibility.

  Next, a second free-form surface constituting the rear side surface 114b of the lens 114 is generated. The generation of the second free-form surface is performed by continuously forming a surface element having an inclination angle for realizing light emission at a target emission angle set for each point on the front surface 114a. .

  FIG. 12 is a diagram showing a procedure for generating a free curve C2 constituting the horizontal sectional shape of the second free curved surface.

  First, as shown in FIG. 2A, the lens necessary for emitting light at a target emission angle α from a point P on a free curve C1 constituting the horizontal cross-sectional shape of the front surface 114a of the lens 114. The light incident direction to the point P in 114 is calculated.

  At this time, since the front surface 114a of the lens 114 is formed of a first free-form surface corresponding to the surface shape of the vehicle body, the direction of the normal line N1 of the free curve C1 at the point P is known. Therefore, the light incident direction (direction indicated by the straight line L2) to the point P corresponding to the light emission direction from the point P (direction indicated by the straight line L1) is calculated using Snell's law.

  Next, as shown in FIG. 4B, the point R where the free curve C2 in the process of intersecting the straight line L2 and the second focal point F2 are connected by a straight line L3, and the angle δ between the straight line L3 and the straight line L2 Is calculated.

  The free curve C2 is generated starting from a point S near the optical axis Ax as will be described later. For convenience of explanation, it is assumed that the free curve C2 has already been generated up to the position of the point R.

  Next, the line element E of the free curve C2 is assigned to the point R. At this time, the direction of the normal N2 of the line element E is calculated using Snell's law so that the refractive power corresponding to the angle δ can be obtained in the line element E, and the inclination angle of the line element E is also calculated simultaneously. To do. As a result, the light emitted from the second focal point F2, which is the light emission center of the secondary light source, is emitted from the lens 114 forward of the lamp along the optical path of the straight lines L3 to L2 to L1.

  Then, on the free curve C1, the calculation is performed on the point adjacent to the right side of the point P (that is, the side away from the optical axis Ax) in the same procedure as in the case of the point P, and the line adjacent to the right side of the line element E The prime tilt angle is calculated. Thereafter, the same processing is repeated to continuously form these series of line elements, thereby generating a portion located on the right side of the optical axis Ax in the free curve C2.

  The free curve C2 is generated by setting a point P0 located on the optical axis Ax on the free curve C1 as a reference point. At this time, the starting point S when the free curve C2 is generated is set at a position near the optical axis Ax as a point corresponding to the reference point P0. The position of the starting point S in the front-rear direction of the lamp is separated from the reference point P0 to such an extent that the second free-form surface can be generated over the entire rear surface 114b of the lens 114, and the lens 114 is unnecessarily thick. The position is set as close as possible to the reference point P0 so as not to become meat.

  The portion located on the left side of the optical axis Ax in the free curve C2 is also generated in the same procedure starting from the point S near the optical axis Ax.

  Then, the second free curve C2 is generated not only on the plane including the optical axis Ax but also on each of a plurality of planes parallel to the plane located on both upper and lower sides of the plane by the same procedure as that for generating the free curve C2. A free curve that forms the horizontal cross-sectional shape of the curved surface is generated.

  In addition, the free curve that forms the vertical cross-sectional shape of the second free-form surface constituting the rear surface 114b of the lens 114 is also generated in the same procedure as the free-curve C2 generation procedure. As the envelopes of the plurality of free curves constituting the horizontal sectional shape and the plurality of free curves constituting the vertical sectional shape (that is, the line elements and the vertical sectional shape of each of the plurality of free curves constituting the horizontal sectional shape) The second free-form surface is generated by continuously forming a plurality of surface elements arranged in a matrix in combination with each of the line elements of the plurality of free-form curves constituting the s.

  As described above in detail, the vehicular illumination lamp 110 according to the present embodiment uses the light from the light source bulb 112 arranged on the optical axis Ax extending in the lamp front-rear direction to the lens 114 arranged on the front side of the lamp. The lens 114 is configured to be deflected and emitted toward the front of the lamp to form a high beam light distribution pattern PH. However, since the front surface 114a of the lens 114 is formed of a first free-form surface, The front surface 114a is formed in a shape along the surface shape of the vehicle body (in this embodiment, a curved surface shape extending substantially at the same interval as the transparent light-transmitting cover 102 extending substantially flush with the vehicle body surface). Is easily possible.

  Further, in the vehicular illumination lamp 110 according to the present embodiment, the emission angle of the light emitted from the front surface 114a of the lens 114 with respect to the optical axis Ax depends on the shape of the high beam light distribution pattern PH and the light intensity distribution thereof. Since the target emission angle is set for each point on the front surface 114a, the high beam light distribution pattern PH can be formed with high accuracy.

  Furthermore, in the vehicular illumination lamp 110 according to the present embodiment, the rear surface 114b of the lens 114 realizes light emission at a target emission angle set for each point on the front surface 114a. Since it is composed of a second free-form surface formed by continuously forming surface elements having an inclination angle, it is possible to obtain an optical path necessary for the light emission without causing a step or the like on the rear surface 114b. it can.

  As described above, the vehicular illumination lamp 110 according to the present embodiment can form a desired high-beam light distribution pattern PH even though the front surface 114a of the lens 114 is a free-form surface. . As a result, the degree of freedom in lamp layout and vehicle design can be increased.

  In addition, the front surface 114a and the rear surface 114b of the lens 114 of the vehicular illumination lamp 110 according to the present embodiment are both free-form surfaces, so that no step or the like is formed on the surface of the lens 114. Thus, the appearance of the vehicular illumination lamp 110 can be improved.

  Further, the vehicular illumination lamp 110 according to the present embodiment is a reflector 116 having a reflecting surface 116a made of a spheroid having a light emission center as a first focal point F1 and light emitted from a discharge light emitting unit 112a as a primary light source. The secondary light source is formed at the position of the second focal point F2 by being reflected and converged on the second focal point F2 of the spheroid, and the light from the secondary light source is emitted by the lens 114 to the front of the lamp. Compared to the case where the discharge light emitting unit 112a is disposed at the position of the second focal point F2 and the direct light is incident on the lens 114, the light emitted from the discharge light emitting unit 112a The luminous flux utilization factor can be increased, and the luminance unevenness of the light source can be reduced. As a result, the high-beam light distribution pattern PH can be a brighter light distribution pattern with less light distribution unevenness.

  Next, a third embodiment of the present invention will be described.

FIG. 13 is a plan sectional view showing the vehicular illumination lamp 210 according to the present embodiment. FIG. 14 shows the XIV-XIV of FIG.
FIG. 15 is a cross-sectional view taken along line XV in FIG.

  As shown in these drawings, the vehicular illumination lamp 210 according to this embodiment has the same basic configuration as that of the first embodiment, but the lens 214 has the same configuration as that of the first embodiment. Part of the form is different.

  That is, the lens 214 of the present embodiment is formed such that the central region 214a2 located in the vicinity of the optical axis Ax on the front surface 214a thereof is displaced rearward from the general peripheral region 214a1 surrounding the central region 214a2. Has been.

  That is, the front surface 214a of the lens 214 has a general peripheral region 214a1 having the same first free-form surface as the front surface 14a of the lens 14 in the first embodiment (see FIGS. The central region 214a2 is formed in a shape substantially similar to the first free-form surface with the light emission center O of the light-emitting diode 12 as a reference, while the free-form curves C1h and C1v are shown. 3 free-form surfaces (the free curves C3h and C3v constituting the cross-sectional shape are shown in FIGS. 13 and 14). The central region 214a2 and the general peripheral region 214a1 are connected via an annular wall surface 214c.

  The surface shape of the rear surface 214b of the lens 214 is exactly the same as the surface shape of the rear surface 14b of the lens 14 in the first embodiment.

  FIG. 16 is a detailed view of the XVI portion of FIG.

  As shown in the figure, the third free-form surface constituting the central region 214a2 on the front surface 214a of the lens 214 is precisely incident on the rear surface 214b of the lens 214, and each of the central regions 214a2 If the central region 214a2 is not formed and the general peripheral region 214a1 is extended along the first free-form surface, the light from the light emitting diode 12 that reaches the point will be emitted. This is a free curved surface generated with reference to the rear surface 214b of the lens 214 so as to be emitted in the direction indicated by the two-dot chain line in FIGS. The third free-form surface generated in this way is formed in a shape substantially similar to the first free-form surface based on the light emission center O of the light emitting diode 12 as described above.

  As shown in the figure, the inclination angle μ of the annular wall surface 214c in the plane including the optical axis Ax is set to be approximately the same value as the outgoing angle φ of the outgoing light from the outer peripheral edge of the central region 214a2 with respect to the optical axis Ax. ing. This prevents a part of the light emitted from the central region 214a2 from reentering the lens 214 from the annular wall surface 214c and exiting from the general peripheral region 214a1 in an unexpected direction. It has become.

  At this time, since the emission angle φ varies depending on the position of the plane including the optical axis Ax, the inclination angle μ of the annular wall surface 214c is also set to a different value depending on the circumferential position of the annular wall surface 214c. ing.

  By adopting the configuration of this embodiment, the lens 214 can be reduced in thickness and weight, and the light transmission efficiency from the light emitting diode 12 can be increased by the reduced thickness.

  In particular, since the front surface 214a and the rear surface 214b of the lens 214 of the present embodiment are both free-form surfaces, it can be ensured that the surface accuracy is achieved by using a synthetic resin lens. In this case, however, if the thickness of the lens 214 is partially extremely thick, sink marks are likely to occur, and it becomes difficult to ensure surface accuracy. In this regard, if the central region 214a2 located near the optical axis Ax on the front surface 214a is displaced rearward from the general peripheral region 214a1 as in the lens 214 of the present embodiment, the lens 214 It is possible to prevent the thickness of the film from becoming extremely thick partially, and it is possible to easily ensure surface accuracy.

  At this time, the third free-form surface constituting the central region 214a2 is formed in a shape substantially similar to the first free-form surface with respect to the light emission center O of the light-emitting diode 12, so that each of the central regions 214a2 The light emitted from the point is light directed in substantially the same direction as the light emitted from each point when the front surface 214a of the lens 214 is formed of the first free-form surface over the entire region. it can.

  In addition, the inclination angle μ of the annular wall surface 214c in the plane including the optical axis Ax of the lens 214 is set to substantially the same value as the emission angle φ of the outgoing light from the outer peripheral edge of the central region 214a2 with respect to the optical axis Ax. Therefore, it is possible to prevent a part of the emitted light from the central region 214a2 from reentering the lens 214 from the annular wall surface 214c and exiting from the general peripheral region 214a1 in an unexpected direction. And thereby, it can suppress effectively that the light control function of the lens 214 is impaired since the annular wall surface 214c was formed.

  Further, by adopting the lens 214 of the present embodiment, it is possible to suppress a temperature rise in the lens 214 when the lamp is turned on, which is preferable for a lens made of synthetic resin having poor heat resistance. In the vehicular illumination lamp 210 according to the present embodiment, since the light source is the light-emitting diode 12, the temperature rise in the lens 214 is not particularly serious, but the vehicular illumination according to the second embodiment. When the light source is the light source bulb 112 as in the case of the lamp 110, the temperature rise in the lens 114 is considerably large. Therefore, the lens configuration as in this embodiment is adopted for the lens 114. Is particularly effective.

  In each of the above embodiments, the vehicle illumination lamps 10, 110, and 210 that are mounted on the left front end corner portion of the vehicle body have been described. However, the vehicle illumination lamp that is mounted on the right front end corner portion of the vehicle body is also described. By forming these in a left-right symmetric shape with respect to the vehicular illumination lamps 10, 110, 210, it is possible to obtain the same functions and effects as in the above embodiments.

Plan sectional drawing which shows the illumination lamp for vehicles which concerns on 1st Embodiment of this invention. II-II sectional view of Fig. 1 View along arrow III in Fig. 1 The figure which shows perspectively the horizontally long light distribution pattern formed on the virtual vertical screen arrange | positioned in the position of 25 m ahead of the vehicle with the light irradiated from the said vehicle lighting device. The figure which shows the target emission angle from each point on the front side surface of the lens in the said vehicle lighting device The figure which shows the procedure which produces | generates the 2nd free-form surface which comprises the back side surface of the said lens. Front view showing a vehicular illumination lamp according to a second embodiment of the present invention Sectional view taken along line VIII-VIII in FIG. IX-IX line cross section of FIG. The figure which shows perspectively the light distribution pattern for high beams formed on the said virtual vertical screen with the light irradiated from the vehicle lighting device which concerns on the said 2nd Embodiment. The figure which shows the target emission angle from each point on the front side surface of the lens in the vehicle lighting device which concerns on the said 2nd Embodiment. The figure which shows the procedure which produces | generates the 2nd free-form surface which comprises the back side surface of the lens in the vehicle lighting device which concerns on the said 2nd Embodiment. Plan sectional drawing which shows the illumination lamp for vehicles which concerns on 3rd Embodiment of this invention. XIV-XIV cross-sectional view of Fig. 13 XV direction arrow view of FIG. Detailed view of XVI part in Fig. 13

Explanation of symbols

2 Car body 10, 110, 210 Vehicle lighting lamp 12 Light emitting diode 12a Light emitting chip 12b Resin mold 14, 114, 214 Lens 14a, 114a, 214a Front side surface 14b, 114b, 214b Rear side surface 16 Support plate 18, 118 Holder 18a Rear vertical surface portion 18b Front end surface 18c Small hole 102 Translucent cover 112 Light source bulb 112a Discharge light emitting portion 114c Annular flange portion 116 Reflector 116a Reflective surface 116b Rear apex opening portion 214a1 General peripheral region 214a2 Central region 214c Annular wall surface Ax Optical axis Ax0 Front and rear of vehicle Axis extending in the direction C1, C1h, C1v, C2, C3h, C3v Free curve E Line element F1 First focus F2 Second focus HZ Hot zone L0, L1, L2, L3 Straight line N1, N2 Normal O Light emitting P, Q, R point P0 Reference point PC Horizontal light distribution pattern PH High beam light distribution pattern S Starting point α Target emission angle in horizontal direction β Target emission angle in vertical direction δ angle θH Horizontal opening angle θV Vertical opening angle μ Inclination Angle ν Predetermined angle φ Output angle

Claims (6)

A light source disposed on an optical axis extending in the front-rear direction of the lamp, and a lens disposed on the front side of the lamp of the light source and deflecting and emitting light from the light source toward the front of the lamp. In a vehicular lighting fixture configured to form a pattern,
The front surface of the lens is composed of a first free-form surface,
The emission angle of the light emitted from the front surface with respect to the optical axis is set as a target emission angle for each point on the front surface,
The rear surface of the lens is composed of a second free-form surface formed by continuously forming a surface element having an inclination angle for realizing light emission at a target emission angle set for each point. And
The target emission angle in the vertical direction is maintained at a constant value even if the vertical opening angle is increased above the optical axis, while the vertical opening angle is increased below the optical axis. It is set so that it may become large according to, The illumination lamp for vehicles characterized by the above-mentioned. A light source disposed on an optical axis extending in the front-rear direction of the lamp, and a lens disposed on the front side of the lamp of the light source and deflecting and emitting light from the light source toward the front of the lamp. In a vehicular lighting fixture configured to form a pattern,
  The front surface of the lens is composed of a first free-form surface,
  The emission angle of the light emitted from the front surface with respect to the optical axis is set as a target emission angle for each point on the front surface,
  The rear surface of the lens is composed of a second free-form surface formed by continuously forming a surface element having an inclination angle for realizing light emission at a target emission angle set for each point. And
  The target emission angle in the vertical direction is set so as to increase as the vertical opening angle increases on either side above and below the optical axis, and the light on the lower side of the optical axis. The vehicular illumination lamp, wherein the change rate of the target emission angle is set to a value smaller than that on the upper side of the shaft. A central area located in the vicinity of the optical axis on the front surface of the lens is substantially similar to the first free-form surface with respect to the position of the light source on the rear side of the general peripheral area surrounding the central area. It consists of a third free-form surface formed into a shape,
The vehicular illumination lamp according to claim 1 or 2, wherein the central area and the general peripheral area are connected via an annular wall surface. The inclination angle of the annular wall surface in a plane including the optical axis is set to be substantially the same value as the emission angle of the outgoing light from the outer peripheral edge of the central region with respect to the optical axis. Item 4. A vehicle illumination lamp according to Item 3 . The light source consists of light-emitting chips of the light emitting element, the direct light is vehicle lighting device according to any one of claims 1 to 4, characterized in that, is configured to be incident on the lens from the light emitting chip. The light source reflects light from a primary light source arranged behind the position of the light source by a reflector having a reflection surface composed of a spheroid having a light emission center of the primary light source as a first focal point. The vehicular illumination lamp according to any one of claims 1 to 4 , comprising a secondary light source formed by converging on a second focal point of a spheroidal surface.

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