Vehicle headlight

Abstract

In the present invention, a vehicle headlight that emits light forward comprises: a light source; a first optical element that converts light emitted from the light source into parallel light; and a second optical element that has an incidence surface, an emission surface, and a side surface connecting the incidence surface and the emission surface. A first region of a lamp front surface is irradiated using light that is incident on the emission surface from the incident surface of the second optical element without being directed toward the side surface. A second region positioned to the left and / or right of the first region is irradiated at an illuminance lower than the illuminance of the first region by using the light that is incident on the emission surface after being reflected by the side surface.

Description

Vehicle headlights

[0001] The present disclosure relates to a vehicle headlamp.

[0002] Patent Document 1 discloses a vehicle headlamp that includes an optical unit in which a reflector that reflects light from a light source and a lens that deflects the light reflected by the reflector and irradiates it outside the optical unit are integrally formed with a translucent member that transmits the light from the light source.

[0003] Japanese Patent Application Publication No. 2004-241349

[0004] However, in an optical unit having such a light-transmitting member, if the length of the light-transmitting member in the front-to-rear direction is greater than the length of the light-transmitting member in the left-to-right direction, it becomes difficult to obtain a diffused component in the left-to-right direction in the light distribution.

[0005] An object of the present disclosure is to provide a vehicle headlamp that is capable of forming a diffused light distribution pattern.

[0006] A vehicle headlamp according to one aspect of the present disclosure is a vehicle headlamp that emits light forward, and includes: a light source; a first optical element that converts the light emitted from the light source into parallel light; and a second optical element having an entrance surface, an exit surface, and a side surface connecting the entrance surface and the exit surface, wherein a first area on the front of the lamp is illuminated by light that enters the exit surface from the entrance surface of the second optical element without traveling toward the side surface, and a second area located at least to the left or right of the first area is illuminated at an illuminance lower than the illuminance of the first area by light that travels from the entrance surface of the second optical element toward the side surface, is reflected by the side surface, and then enters the exit surface.

[0007] According to the present disclosure, it is possible to provide a vehicle headlamp that can form a diffused light distribution pattern.

[0008] FIG. 5 is a plan view illustrating the configuration of an optical unit according to a first embodiment of the present disclosure. FIG. 6 is a cross-sectional view illustrating a configuration of a cross section taken along line II-II in FIG. 1 as viewed from the direction of the arrows. FIG. 7 illustrates a low-beam light distribution pattern projected on a virtual vertical screen by light emitted from the optical unit. FIG. 7 is a plan view illustrating the configuration of an optical unit according to a first modified example of the present disclosure. FIG. 8 is a cross-sectional view illustrating a configuration of an optical unit according to a second embodiment of the present disclosure. FIG. 9 is a cross-sectional view illustrating a configuration of a cross section taken along line VI-VI in FIG. 5 as viewed from the direction of the arrows. FIG. 10 is a plan view illustrating the configuration of an optical unit according to a third modified example of the present disclosure.

[0009] Hereinafter, examples of embodiments of the present disclosure will be described with reference to the drawings. In each drawing used in the following description, the scale has been changed as necessary so that each component can be recognized. In addition, in the drawings, arrow U indicates the upward direction of the illustrated structure. Arrow D indicates the downward direction of the illustrated structure. Arrow F indicates the forward direction of the illustrated structure. Arrow B indicates the backward direction of the illustrated structure. Arrow R indicates the rightward direction of the illustrated structure. Arrow L indicates the leftward direction of the illustrated structure. These directions are relative directions set for the optical unit 10 shown in FIG. 1, and the direction of light irradiation from the optical unit 10 is the forward direction.

[0010] First Embodiment Fig. 1 is a plan view illustrating the configuration of an optical unit 10 according to a first embodiment of the present disclosure. Fig. 2 is a cross-sectional view illustrating the configuration of a cross section taken along line II-II in Fig. 1 as viewed from the direction of the arrows.

[0011] The optical unit 10 is mounted in a vehicle headlamp and configured to form a low-beam light distribution pattern including a cut-off line ahead. The vehicle headlamp includes an outer lens and a housing (not shown) in addition to the optical unit 10 shown in Fig. 1, and the optical unit 10 is disposed within a lamp chamber formed by the outer lens and the housing.

[0012] 1, the optical unit 10 includes a light source 11, a reflector 12, and a lens element 13. The reflector 12 is an example of a first optical element. The lens element 13 is an example of a second optical element.

[0013] The light source 11 is mounted on the substrate 14 with its light-emitting surface facing rearward. A heat sink may be provided on the front surface of the substrate 14. The light source 11 may be an LED (Light Emitting Diode) or an LD (Laser Diode).

[0014] The reflector 12 is configured to convert the light emitted from the light source 11 into parallel light and emit it to the lens element 13. The reflector 12 is attached to, for example, a substrate 14 on which the light source 11 is disposed.

[0015] Specifically, as illustrated in Fig. 2, the reflector 12 has a reflecting surface 121 that reflects light emitted from the light source 11. For example, the reflecting surface 121 is formed as a parabolic surface. In this example, the parabolic surface is a paraboloid of revolution obtained by rotating a parabola around an axis extending in the vertical direction. The reflecting surface 121 formed as a parabolic surface is configured as a reflecting surface that reflects light emitted from the focus of the parabola downward as parallel light. The light source 11 is disposed near the focus of the parabolic surface that constitutes the reflecting surface 121.

[0016] 1 and 2, the lens element 13 has an incident surface 131, a reflecting surface 132, a plurality of exit surfaces 133, a first side surface 134, and a second side surface 135. The lens element 13 is formed of, for example, a transparent resin material or a glass material.

[0017] The incident surface 131 is formed on the upper surface of the lens element 13. Light emitted from the light source 11 and converted into parallel light by the reflector 12 is incident on the incident surface 131.

[0018] Reflecting surface 132 is formed on the rear surface of lens element 13. Reflecting surface 132 is configured to reflect a portion of the parallel light incident on lens element 13 from incident surface 131 toward exit surface 133. Reflecting surface 132 is also configured to reflect a portion of the parallel light incident on lens element 13 toward first side surface 134 or second side surface 135. Reflecting surface 132 is formed so that the amount of light reflected toward first side surface 134 or second side surface 135 is less than the amount of light reflected toward exit surface 133.

[0019] In this example, the reflecting surface 132 has a convex shape facing backward when viewed from above, and is configured so that the light reflected by the reflecting surface 132 is focused behind the focal position f of the emitting surface 133.

[0020] The plurality of exit surfaces 133 are formed on the front surface of the lens element 13. In other words, the front surface of the lens element 13 is divided into the plurality of exit surfaces 133. The plurality of exit surfaces 133 are aligned in the left-right direction. In this example, three exit surfaces 133A, 133B, and 133C are aligned in the left-right direction. Each of the plurality of exit surfaces 133 has a forward convex lens shape with a single focal point. Each of the plurality of exit surfaces 133 is configured to refract and emit light that reaches the exit surface 133 in any direction, thereby forming a desired light distribution pattern.

[0021] The first side surface 134 is formed on the left surface of the lens element 13 so as to connect the incident surface 131 and the exit surface 133. The first side surface 134 is configured to reflect light that has been reflected by the reflecting surface 132 and reached the first side surface 134. For example, the first side surface 134 is configured to totally reflect the light.

[0022] Second side surface 135 is formed on the right surface of lens element 13 so as to connect incident surface 131 and exit surface 133. Second side surface 135 is configured to reflect light that has been reflected by reflecting surface 132 and reached second side surface 135. For example, second side surface 135 is configured to totally reflect light.

[0023] In FIG. 1 , a virtual plane passing through the focal positions f of the three exit surfaces 133 and perpendicular to the optical axis of each exit surface 133 is shown as focal plane f10. As illustrated in FIG. 2 , the lens element 13 has a cutoff line forming portion 136 near the focal position f of the exit surface 133A. The cutoff line forming portion 136 is formed by the boundary between the first surface 137 and the second surface 138. The first surface 137 extends to the focal position f of the exit surface 133A on a plane including the front-rear and left-right directions. The second surface 138 extends to the focal position f of the exit surface 133A on a plane including the up-down and left-right directions. The cutoff line forming portion 136 has a shape corresponding to the cutoff line of the low-beam light distribution pattern. For example, the cutoff line forming portion 136 extends in the left-right direction when viewed from the front, and a step is formed in its center.

[0024] Of the light that enters lens element 13 and proceeds toward exit surface 133A, light that proceeds toward a region below cutoff line forming portion 136 is totally reflected by first surface 137 and reaches exit surface 133. As a result, the light distribution pattern formed by the light that has been emitted from exit surface 133A becomes a light distribution pattern that has a cutoff line that corresponds to cutoff line forming portion 136.

[0025] 3 illustrates a low-beam light distribution pattern PL projected onto a virtual vertical screen by light emitted from the optical unit 10. The virtual vertical screen is placed, for example, at a position 25 m in front of the optical unit 10. In FIG. 3 , H indicates the horizontal line, and V indicates the vertical line passing through the center of the illumination range of the optical unit 10.

[0026] The low-beam distribution pattern PL has a cutoff line CL corresponding to the cutoff line forming portion 136 of the lens element 13. The low-beam distribution pattern PL includes a first region P1, a second region P2, and a third region P3.

[0027] The first region P1 is located on the front surface of the optical unit 10. The first region P1 is irradiated by light that is reflected by the reflecting surface 132 of the lens element 13 and directly enters the exit surface 133 without traveling toward the first side surface 134 and the second side surface 135.

[0028] 1, a portion of the parallel light beams incident on the lens element 13 from the incident surface 131, that is, light L11, is reflected by the reflecting surface 132 toward the exit surface 133. The light L11 is incident on the exit surface 133 without traveling toward the first side surface 134 or the second side surface 135, and is emitted forward from the exit surface 133. This light L11 forms a first region P1 of the low-beam light distribution pattern PL.

[0029] 3, the second region P2 is located to the right of the first region P1. The second region P2 is irradiated with light that is reflected by the reflecting surface 132 of the lens element 13 toward the first side surface 134, and is then reflected by the first side surface 134 and incident on the exit surface 133.

[0030] 1 , light L12, which is a portion of the parallel light incident on the lens element 13 from the incident surface 131, is reflected by the reflecting surface 132 toward the first side surface 134. The light L12 is reflected by the first side surface 134, enters the exit surface 133, and is emitted from the exit surface 133 diagonally forward to the right. This light L12 forms a second region P2 of the low-beam light distribution pattern PL. Because the amount of light L12 is less than the amount of light L11, the second region P2 is irradiated with an illuminance lower than the illuminance of the first region P1.

[0031] 3, the third region P3 is located to the left of the first region P1. The third region P3 is irradiated with light that is reflected by the reflecting surface 132 of the lens element 13 toward the second side surface 135, and is then reflected by the second side surface 135 and enters the exit surface 133.

[0032] 1 , light L13, a portion of the parallel light incident on lens element 13 from incident surface 131, is reflected by reflecting surface 132 toward second side surface 135. Light L13 is reflected by second side surface 135, incident on exit surface 133, and emitted from exit surface 133 diagonally forward to the left. This light L13 forms third region P3 of low beam light distribution pattern PL. Because the amount of light L13 is less than the amount of light L11, third region P3 is irradiated with an illuminance lower than the illuminance of first region P1.

[0033] According to the optical unit 10 according to the first embodiment of the present disclosure, a portion of the light emitted from the light source 11, converted into parallel light by the reflector 12, and incident on the lens element 13 is reflected by the first side surface 134 or the second side surface 135 and is emitted diffused in the left-right direction from the exit surface 133. This makes it possible to form a low-beam light distribution pattern PL that is widely diffused left-right with a simple configuration.

[0034] In the above first embodiment, the lens element 13 may be configured so that a portion of the parallel light L11 incident on the lens element 13 is incident on the exit surface 133A of the multiple exit surfaces 133, the light L12 incident on the lens element 13 and reflected by the first side surface 134 is incident on the exit surface 133B of the multiple exit surfaces 133, and the light L13 incident on the lens element 13 and reflected by the second side surface 135 is incident on the exit surface 133C of the multiple exit surfaces 133.

[0035] In the illustrated example, light L12 emitted from light source 11 and reflected by the right portion of reflecting surface 132 is incident on exit surface 133B, which is located at the leftmost position among exit surfaces 133. Because light L12 passes to the left of the focal point of exit surface 133B before entering exit surface 133B, light L12 is refracted at exit surface 133B and emitted to the right. Similarly, light L13 emitted from light source 11 and reflected by the left portion of reflecting surface 132 is incident on exit surface 133C, which is located at the rightmost position among exit surfaces 133. Because light L13 passes to the right of the focal point of exit surface 133C before entering exit surface 133C, light L13 is refracted at exit surface 133C and emitted to the left.

[0036] With this configuration, each exit surface 133 can be designed independently, allowing for greater freedom in the design of the exit surfaces 133. For example, exit surface 133A located in front of reflecting surface 132 can be optically designed to direct light to first region P1, and left and right exit surfaces 133B and 133C can be optically designed to direct light reflected by first side surface 134 or second side surface 135 to second region P2 or third region P3 at a desired angle.

[0037] (Variation 1) Figure 4 is a plan view illustrating the configuration of an optical unit 100 according to Variation 1 of the present disclosure. Elements that are substantially the same as elements in the configuration of the first embodiment described with reference to Figures 1 and 2 are given the same reference numerals, and repeated explanations will be omitted. Furthermore, the cross-sectional shape of the optical unit 100 is basically the same as the cross-sectional shape of the optical unit 10 shown in Figure 2, so a cross-sectional view will be omitted.

[0038] The optical unit 10 of the first embodiment described above has one light source 11. In contrast, the optical unit 100 of the present modified example 1 has multiple light sources 11. In this example, three light sources 11A, 11B, and 11C are arranged on the substrate 14. The light source 11B is provided to the left of the light source 11A, and the light source 11C is provided to the right of the light source 11A.

[0039] 4 , light L11A, a portion of the parallel light emitted from light source 11A and incident on lens element 13 from incident surface 131, is reflected by reflecting surface 132 toward exit surface 133A. Furthermore, light L11B, a portion of the parallel light emitted from light source 11B and incident on lens element 13 from incident surface 131, is reflected by reflecting surface 132 toward exit surface 133A. Furthermore, light L11C, a portion of the parallel light emitted from light source 11C and incident on lens element 13 from incident surface 131, is reflected by reflecting surface 132 toward exit surface 133A. These light beams L11A, L11B, and L11C are incident on exit surface 133A without traveling toward first side surface 134 and second side surface 135, and are emitted forward from exit surface 133A. The light beams L11A, L11B, and L11C illuminate a first region P1 of the low-beam light distribution pattern PL illustrated in FIG.

[0040] Furthermore, light L12A, a portion of the parallel light emitted from light source 11A and incident on lens element 13 from incident surface 131, is reflected by reflecting surface 132 toward first side surface 134. Light L12B, a portion of the parallel light emitted from light source 11B and incident on lens element 13 from incident surface 131, is reflected by reflecting surface 132 toward first side surface 134. Light L12C, a portion of the parallel light emitted from light source 11C and incident on lens element 13 from incident surface 131, is reflected by reflecting surface 132 toward first side surface 134. These light beams L12A, L12B, and L12C are each reflected by first side surface 134, incident on exit surface 133B, and emitted from exit surface 133B diagonally forward to the right. A second region P2 of the low-beam light distribution pattern PL is illuminated by light beams L12A, L12B, and L12C.

[0041] Furthermore, light L13A, a portion of the parallel light emitted from light source 11A and incident on lens element 13 from incident surface 131, is reflected by reflecting surface 132 toward second side surface 135. Light L13B, a portion of the parallel light emitted from light source 11B and incident on lens element 13 from incident surface 131, is reflected by reflecting surface 132 toward second side surface 135. Light L13C, a portion of the parallel light emitted from light source 11C and incident on lens element 13 from incident surface 131, is reflected by reflecting surface 132 toward second side surface 135. These light beams L13A, L13B, and L13C are each reflected by second side surface 135, incident on exit surface 133C, and emitted from exit surface 133C diagonally forward and to the left. A third region P3 of low-beam light distribution pattern PL is illuminated by light beams L13A, L13B, and L13C.

[0042] According to optical unit 100 according to the first modification of the present disclosure, a portion of the light emitted from each of the plurality of light sources 11, converted into parallel light by reflector 12, and incident on lens element 13 is reflected by first side surface 134 or second side surface 135 and emitted diffused in the left-right direction from exit surface 133. This makes it possible to form a low-beam light distribution pattern PL that is widely diffused left-right with a simple configuration.

[0043] In the first embodiment and the first modification, the light source and the reflector are disposed on the upper side, and the lens element is disposed on the lower side. However, the light source and the reflector may be disposed on the lower side, and the lens element may be disposed on the upper side.

[0044] Second Embodiment Fig. 5 is a plan view illustrating the configuration of an optical unit 20 according to a second embodiment of the present disclosure. Fig. 6 is a cross-sectional view illustrating the configuration of a cross section taken along line VI-VI in Fig. 5 as viewed from the direction of the arrows.

[0045] The optical unit 20 is mounted in a vehicle headlamp and configured to form a low-beam light distribution pattern including a cut-off line ahead.

[0046] 5, the optical unit 20 includes a light source 21, a primary lens 22, and a lens element 23. The primary lens 22 is an example of a first optical element. The lens element 23 is an example of a second optical element.

[0047] The light source 21 is mounted on a substrate (not shown) with its light-emitting surface facing forward. The light source 21 may be an LED or an LD.

[0048] The primary lens 22 is configured to convert the light emitted from the light source 21 into parallel light and emit the parallel light to the lens element 23. As the primary lens 22, for example, a collimating lens such as a TIR (Total Internal Reflection) lens can be used.

[0049] The lens element 23 has an incident surface 231, a plurality of exit surfaces 232, a first side surface 233, and a second side surface 234. The lens element 23 is formed of, for example, a transparent resin material or a glass material.

[0050] The incident surface 231 is formed on the rear surface of the lens element 23. Light emitted from the light source 21 and collimated by the primary lens 22 is incident on the incident surface 231. The incident surface 231 is configured to refract a portion of the collimated light incident on the lens element 23 toward the exit surface 232. The incident surface 231 is also configured to refract a portion of the collimated light incident on the lens element 23 toward the first side surface 233 or the second side surface 234. The incident surface 231 is formed so that the amount of light refracted toward the first side surface 233 or the second side surface 234 is less than the amount of light refracted toward the exit surface 232.

[0051] In this example, the incident surface 231 has a convex shape facing backward when viewed from above, and is configured so that light refracted by the incident surface 231 is focused behind the focal position f of the exit surface 232.

[0052] The plurality of exit surfaces 232 are formed on the front surface of the lens element 23. In other words, the front surface of the lens element 23 is divided into the plurality of exit surfaces 232. The plurality of exit surfaces 232 are aligned in the left-right direction. In this example, three exit surfaces 232A, 232B, and 232C are aligned in the left-right direction. Each of the plurality of exit surfaces 232 has a forward-convex lens shape with a single focal point. Each of the plurality of exit surfaces 232 is configured to refract light that reaches the exit surface 232 in any direction and emit the light to form a desired light distribution pattern. In the illustrated example, when viewed from the front, the exit surface 232A is positioned so as to overlap with the incident surface 231, the exit surface 232B is positioned to the right of the incident surface 231, and the exit surface 232C is positioned to the left of the incident surface 231.

[0053] First side surface 233 is formed on the left surface of lens element 23 so as to connect incident surface 231 and exit surface 232. In this example, incident surface 231 and first side surface 233 are connected by first connecting surface 235. First side surface 233 is configured to reflect light that has been refracted by incident surface 231 and reached first side surface 233. For example, first side surface 233 is configured to totally reflect light.

[0054] The second side surface 234 is formed on the right surface of the lens element 23 so as to connect the incident surface 231 and the exit surface 232. In this example, the incident surface 231 and the second side surface 234 are connected by a second connecting surface 236. The second side surface 234 is configured to reflect light that has been refracted by the incident surface 231 and reached the second side surface 234. For example, the second side surface 234 is configured to totally reflect light.

[0055] The first side surface 233 and the second side surface 234 are provided behind the focal position of the incident surface 231 in the front-rear direction. In addition, the first side surface 233 and the second side surface 234 are provided near the focal plane f10 of the exit surface 232 in the front-rear direction.

[0056] As illustrated in FIG. 6 , the lens element 23 has a cutoff line forming portion 237 near the focal position f of the light exit surface 232A. The cutoff line forming portion 237 is formed by the boundary between the first surface 238 and the second surface 239. The first surface 238 extends to the focal position f of the light exit surface 232A on a plane including the front-rear direction and the left-right direction. The second surface 239 extends to the focal position f of the light exit surface 232A on a plane including the up-down direction and the left-right direction. The cutoff line forming portion 237 has a shape corresponding to the cutoff line of the low beam light distribution pattern. For example, the cutoff line forming portion 237 extends in the left-right direction when viewed from the front, and a step is formed in the center.

[0057] Of the light that enters lens element 23 and proceeds toward exit surface 232A, light that proceeds toward a region below cutoff line forming portion 237 is totally reflected by first surface 238 and reaches exit surface 232. As a result, the light distribution pattern formed by the light emitted from exit surface 232A becomes a light distribution pattern having a cutoff line that corresponds to cutoff line forming portion 237. The light distribution patterns formed by the light emitted from each exit surface 232 are superimposed to form a low-beam light distribution pattern PL as illustrated in FIG.

[0058] 5 , light L21, which is a portion of the parallel light incident on the lens element 23 from the incident surface 231, is refracted by the incident surface 231 toward the exit surface 232. The light L21 is incident on the exit surface 232 without traveling toward the first side surface 233 or the second side surface 234, and is emitted forward from the exit surface 232. This light L21 illuminates a first region P1 in front of the lamp in the low-beam light distribution pattern PL.

[0059] Furthermore, light L22, a portion of the parallel light incident on the lens element 23 from the incident surface 231, is refracted by the incident surface 231 toward the first side surface 233. The light L22 is reflected by the first side surface 233 to enter the exit surface 232 and is emitted from the exit surface 232 diagonally forward to the right. This light L22 illuminates a second region P2 located to the right of the first region P1 in the low-beam light distribution pattern PL. Because the amount of light L22 is less than the amount of light L21, the second region P2 is illuminated with an illuminance lower than the illuminance of the first region P1.

[0060] Furthermore, light L23, a portion of the parallel light incident on the lens element 23 from the incident surface 231, is refracted by the incident surface 231 toward the second side surface 234. The light L23 is reflected by the second side surface 234, incident on the exit surface 232, and emitted from the exit surface 232 diagonally forward to the left. This light L23 illuminates a third region P3 located to the left of the first region P1 in the low-beam light distribution pattern PL. Because the amount of light L13 is less than the amount of light L11, the third region P3 is illuminated with an illuminance lower than the illuminance of the first region P1.

[0061] According to the optical unit 20 according to the second embodiment of the present disclosure, a portion of the light emitted from the light source 21, converted into parallel light by the primary lens 22, and incident on the lens element 23 is reflected by the first side surface 233 or the second side surface 234 and is emitted diffused in the left-right direction from the emission surface 232. This makes it possible to form a low-beam light distribution pattern PL that is widely diffused left-right with a simple configuration.

[0062] In the second embodiment, lens element 23 may be configured such that light L21, a portion of the parallel light incident on lens element 23, is incident on exit surface 232A of the plurality of exit surfaces 232, light L22 incident on lens element 23 and reflected by first side surface 233 is incident on exit surface 232B of the plurality of exit surfaces 232, and light L23 incident on lens element 23 and reflected by second side surface 234 is incident on exit surface 232C of the plurality of exit surfaces 232. With such a configuration, each exit surface 232 can be designed independently, thereby increasing the degree of freedom in designing exit surfaces 232.

[0063] (Modification 2) Figure 7 is a plan view illustrating the configuration of an optical unit 200 according to Modification 2 of the present disclosure. Elements that are substantially the same as elements in the configuration of the second embodiment described with reference to Figures 5 and 6 are given the same reference numerals, and repeated description will be omitted. Furthermore, the cross-sectional shape of the optical unit 200 is basically the same as the cross-sectional shape of the optical unit 20 shown in Figure 6, so a cross-sectional view will be omitted.

[0064] Lens element 23 in the second embodiment described above has one incident surface 231. In contrast, lens element 23 in the present modified example 2 has multiple incident surfaces 231. In this example, lens element 23 has three incident surfaces 231A, 231B, and 231C. First side surface 233 is formed on the left surface of lens element 23 so as to connect incident surface 231B and exit surface 232. Second side surface 234 is formed on the left surface of lens element 23 so as to connect incident surface 231C and exit surface 232.

[0065] Light emitted from the light source 21 and converted into parallel light by the primary lens 22 is incident on each of the plurality of incident surfaces 231. Each of the plurality of incident surfaces 231 is configured to refract the light emitted from the light source 21, converted into parallel light by the primary lens 22, and incident on the lens element 23.

[0066] Furthermore, at least one of the plurality of incident surfaces 231 is configured to refract a portion of the parallel light emitted from the light source 21 and incident on the lens element 23 toward the first side surface 233 or the second side surface 234. In this example, the incident surface 231A is configured to refract light L22, L23, which are portions of the parallel light incident on the lens element 23, toward the first side surface 233 or the second side surface 234.

[0067] Specifically, incident surfaces 231A, 231B, and 231C each have a rearward convex shape when viewed from above. Furthermore, incident surface 231A is configured so that light refracted by incident surface 231A is focused behind focal position f of exit surface 232. In other words, the focal position of incident surface 231A is located behind focal position f of exit surface 232.

[0068] 7 , a portion of light L21 incident on incident surface 231A is refracted by incident surface 231A toward exit surface 232 and emitted forward from exit surface 232. Furthermore, a portion of light L22 incident on incident surface 231A is refracted toward first side surface 233, reflected by first side surface 233, and emitted diagonally forward to the right from exit surface 232. A portion of light L23 incident on incident surface 231A is refracted toward second side surface 234, reflected by second side surface 234, and emitted diagonally forward to the left from exit surface 232.

[0069] Furthermore, light L24 incident on incident surface 231B is refracted toward exit surface 232 and emitted forward from exit surface 232. Specifically, light L24 is incident on the right part of incident surface 231B and is emitted diagonally forward to the right from the left part of exit surface 232B.

[0070] Light L25 incident on incident surface 231C is refracted toward exit surface 232 and emitted forward from exit surface 232. In detail, light L25 is incident on the left part of incident surface 231C and emitted diagonally forward and left from the right part of exit surface 232C.

[0071] A first region P1 in front of the lamp in the low beam distribution pattern PL is illuminated by light L21 emitted forward from the emission surface 232. A second region P2 located to the right of the first region P1 is illuminated by light L22 emitted diagonally forward to the right from the emission surface 232. A third region P3 located to the left of the first region P1 is illuminated by light L23 emitted diagonally forward to the left from the emission surface 232.

[0072] Furthermore, the light L24 emitted from the exit surface 232 diagonally forward to the right illuminates an area between the first area P1 illuminated by the light L21 and the second area P2 illuminated by the light L22. The light L25 emitted from the exit surface 232 diagonally forward to the left illuminates an area between the first area P1 illuminated by the light L21 and the third area P3 illuminated by the light L23.

[0073] According to optical unit 200 according to modification 2 of the present disclosure, a portion of the light emitted from light source 21, converted into parallel light by primary lens 22, and incident on lens element 23 is reflected by first side surface 233 or second side surface 234 and is emitted diffused in the left-right direction from exit surface 232. This makes it possible to form a low-beam light distribution pattern PL that is widely diffused left-right with a simple configuration.

[0074] Furthermore, the parallel light emitted from the left and right ends of the primary lens 22 is incident on the entrance surfaces 231B and 231C arranged on the left and right of the entrance surface 231A and is emitted from the exit surface 232, thereby improving the light utilization efficiency compared to the lens element 13 shown in Figure 5.

[0075] (Variation 3) Fig. 8 is a plan view illustrating the configuration of an optical unit 300 according to Variation 3 of the present disclosure. Elements that are substantially the same as elements in the configuration of Variation 2 described with reference to Fig. 7 are given the same reference numerals, and repeated description will be omitted. Furthermore, the cross-sectional shape of the optical unit 300 is basically the same as the cross-sectional shape of the optical unit 20 shown in Fig. 6, so a cross-sectional view will be omitted.

[0076] The optical unit 200 of the above-described modified example 2 has one light source 21. In contrast, the optical unit 300 of the present modified example 3 has multiple light sources 21. In this example, three light sources 21A, 21B, and 21C are arranged on a substrate (not shown). The light source 21B is provided to the right of the light source 21A, and the light source 21C is provided to the left of the light source 21A.

[0077] 8 , a portion of the parallel light L21A emitted from the light source 21A and incident on the lens element 23 from the incident surface 231 is refracted by the incident surface 231 toward the exit surface 232 and is emitted forward from the exit surface 232. A portion of the parallel light L22A emitted from the light source 21A and incident on the lens element 23 from the incident surface 231 is refracted toward the first side surface 233, reflected by the first side surface 233, and emitted diagonally forward to the right from the exit surface 232. A portion of the parallel light L23A emitted from the light source 21A and incident on the lens element 23 from the incident surface 231 is refracted toward the second side surface 234, reflected by the second side surface 234, and emitted diagonally forward to the left from the exit surface 232.

[0078] In the illustrated example, a portion of light L22B emitted from light source 21B, located to the right of light source 21A, travels leftward relative to light L22A emitted from light source 21A after passing through incident surface 231. In other words, position PB at which light L22B enters first side surface 233 is behind position PA1 at which light L22A enters first side surface 233. Here, position PB is behind focal plane f10, and position PA1 is ahead of focal plane f10. Light L22B enters exit surface 232B at a gentler angle than light L22A. Therefore, light L22B refracted by exit surface 232B travels closer to the center than light L22A refracted by exit surface 232B, and light L22B irradiates between first region P1 and second region P2.

[0079] Similarly, a portion of light L23C emitted from light source 21C, located to the left of light source 21A, passes through incident surface 231 and travels to the right of light L23A emitted from light source 21A. In other words, position PC at which light L23C enters first side surface 233 is behind position PA2 at which light L23A enters first side surface 233. Here, position PC is behind focal plane f10, and position PA2 is ahead of focal plane f10. Light L23C enters exit surface 232C at a gentler angle than light L23A. Therefore, light L23C refracted by exit surface 232C travels closer to the center than light L23A refracted by exit surface 232C, and light L23C irradiates between first region P1 and third region P3.

[0080] According to optical unit 300 according to modification 3 of the present disclosure, a portion of the light emitted from each of the plurality of light sources 21, converted into parallel light by primary lens 22, and incident on lens element 23 is reflected by first side surface 233 or second side surface 234 and emitted diffused in the left-right direction from exit surface 232. This makes it possible to form a low-beam light distribution pattern PL that is widely diffused left-right with a simple configuration.

[0081] In the third modification, the lens element 23 has a plurality of entrance surfaces 231, but the lens element 23 may be configured to have a single entrance surface 231 as illustrated in FIG.

[0082] The present invention is not limited to the above-described embodiments and can be freely modified, improved, etc. The material, shape, dimensions, numerical values, form, number, location, etc. of each component in the above-described embodiments are arbitrary and not limited as long as they can achieve the present invention.

[0083] In the first embodiment and the first modified example, the lens element has one reflecting surface. However, the lens element may be configured to have a plurality of reflecting surfaces.

[0084] The following configurations also constitute part of the present disclosure. Item 1: A vehicle headlamp that emits light forward, comprising: a light source; a first optical element that converts light emitted from the light source into parallel light; and a second optical element having an incident surface, an exit surface, and a side surface connecting the incident surface and the exit surface, wherein a first area on a front surface of the lamp is illuminated by light that enters the exit surface from the incident surface of the second optical element without traveling toward the side surface, and a second area located on at least one side of the first area is illuminated at an illuminance lower than the illuminance of the first area by light that travels from the incident surface of the second optical element toward the side surface, is reflected by the side surface, and then enters the exit surface. Item 2: The vehicle headlamp according to Item 1, wherein the second optical element has a reflective surface that reflects the parallel light emitted from the first optical element, wherein the first region is illuminated by light that is reflected by the reflective surface and enters the exit surface without traveling toward the side surface, and the second region is illuminated by light that is reflected by the reflective surface and travels toward the side surface, reflected by the side surface, and enters the exit surface. Item 3: The vehicle headlamp according to Item 1, wherein the second optical element has an entrance surface that refracts the parallel light emitted from the first optical element, wherein the first region is illuminated by light that is refracted by the entrance surface and enters the exit surface without traveling toward the side surface, and the second region is illuminated by light that is refracted by the entrance surface, travels toward the side surface, reflected by the side surface, and enters the exit surface. Item 4: The vehicle headlamp according to any one of Items 1 to 3, wherein the second optical element has a cutoff line forming portion near a focal position of the exit surface, and the light emitted from the exit surface of the second optical element forms a low beam light distribution pattern. Item 5: The vehicle headlamp according to any one of Items 1 to 4, wherein the second optical element has a plurality of the exit surfaces arranged in the left-right direction.

[0085] This application is based on Japanese Patent Application No. 2024-005120, filed on January 17, 2024, the contents of which are incorporated herein by reference.

Claims

1. A vehicle headlamp that irradiates light forward, comprising a light source, a first optical element that makes the light emitted from the light source into parallel light, and a second optical element having an incident surface, an exit surface, and a side surface connecting the incident surface and the exit surface, wherein a first region on the front of the lamp is irradiated by light that enters the exit surface without going toward the side surface from the incident surface of the second optical element, and a second region located at least on one of the left and right sides of the first region is irradiated with an illuminance lower than the illuminance of the first region by light that goes from the incident surface of the second optical element toward the side surface, is reflected by the side surface, and then enters the exit surface.

2. The vehicle headlamp according to claim 1, wherein the second optical element has a reflecting surface that reflects the parallel light emitted from the first optical element, the first region is irradiated by light that is reflected by the reflecting surface and enters the exit surface without going toward the side surface, and the second region is irradiated by light that is reflected by the reflecting surface, goes toward the side surface, is reflected by the side surface, and then enters the exit surface.

3. The vehicle headlamp according to claim 1, wherein the second optical element has an incident surface that refracts the parallel light emitted from the first optical element, the first region is irradiated by light that is refracted by the incident surface and enters the exit surface without going toward the side surface, and the second region is irradiated by light that is refracted by the incident surface, goes toward the side surface, is reflected by the side surface, and then enters the exit surface.

4. The vehicle headlamp according to any one of claims 1 to 3, wherein the second optical element has a cut-off line forming portion near the focal position of the exit surface, and the light emitted from the exit surface of the second optical element forms a low beam light distribution pattern.

5. The vehicle headlamp according to any one of claims 1 to 3, wherein the second optical element has a plurality of the exit surfaces arranged in the left-right direction.

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