Vehicle headlight

Abstract

An optical unit (1) of a vehicle lamp comprises a light source (10), a primary optical member (20), and a secondary optical member (30). The secondary optical member (30) has, in an integrated manner, a first output surface (321) from which a low beam light distribution pattern is emitted, a second output surface (322) from which an OHS light distribution pattern is emitted, a reflective surface (33) that reflects collimated light from the light source (10) to each of the first output surface (321) and the second output surface (322), and a cut-off line forming part (34) that blocks a portion of the light that is about to be incident on each of the first output surface (321) and the second output surface (322). The reflective surface (33) reflects collimated light to each of the first output surface (321) and the second output surface (322) so that a focal point is formed in the vicinity of the cut-off line forming part (34). A first focal point position (F321) of the first output surface (321) is located in the vicinity of the cut-off line forming part (34), and a second focal point position (F322) of the second output surface (322) is located farther forward than the first focal point position (F321).

Description

Vehicle headlights

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

[0002] Patent Document 1 discloses a vehicle headlamp. The vehicle headlamp includes an incident optical system consisting of a plurality of micro incident optical systems arranged in an array, and an exit optical system consisting of a plurality of micro exit optical systems arranged in an array. Each micro incident optical system is assigned to one micro exit optical system. The micro incident optical systems are configured so that all light emitted from the micro incident optical systems is incident only on the assigned micro exit optical system. The light preformed by the micro incident optical system is imaged as at least one light distribution in an area in front of the vehicle by the micro exit optical system.

[0003] Patent Document 2 discloses a lens component that is mounted on a vehicle headlamp and has multiple integrated optical systems. The lens component includes multiple optical systems each consisting of a pair of an entrance surface and an exit surface, and each optical system is configured to emit a desired light distribution pattern.

[0004] Japanese Patent Publication No. 2016-534503 International Publication No. 2023 / 243345

[0005] When forming multiple different light distribution patterns with a single lighting fixture, providing separate optical systems for each of the multiple light distribution patterns increases the number of parts, and attempting to integrally form multiple optical elements with different shapes increases the difficulty of molding the optical elements.

[0006] The inventors have also devised a vehicle headlamp that forms a low-beam light distribution pattern by combining different light distribution patterns emitted by each optical system. The exit surface of a lens component that integrates multiple optical systems is smaller than that of a plano-convex lens used in conventional optical systems in which the reflector and shade are separate components from the projection lens. Therefore, it has been thought that such lens components are less likely to produce field curvature.

[0007] However, in recent years, there has been a demand for more precise light distribution patterns, which has led to a demand for suppressing field curvature in vehicle headlights that incorporate lens components.

[0008] An object of the present disclosure is to provide a vehicle headlamp that forms a plurality of light distribution patterns while reducing the number of parts and the difficulty of molding optical members.

[0009] Another object of the present disclosure is to provide a vehicle headlamp in which field curvature is suppressed.

[0010] a primary optical element that converts light emitted from the light source into parallel light; and a secondary optical element onto which the parallel light emitted from the primary optical element is incident; wherein the secondary optical element integrally includes: a first emission surface that irradiates a low beam light distribution pattern; a second emission surface that irradiates an OHS light distribution pattern; a reflecting surface that reflects the parallel light to each of the first emission surface and the second emission surface; and a cutoff line forming portion behind each of the first emission surface and the second emission surface that blocks a portion of the parallel light that is about to be incident on each of the first emission surface and the second emission surface, wherein the reflecting surface reflects the parallel light to each of the first emission surface and the second emission surface so as to form a focus in the vicinity of the cutoff line forming portion, A first focal position of the first light exit surface is located near the cutoff line forming portion, and a second focal position of the second light exit surface is located forward of the first focal position.

[0011] Because the shapes of the low-beam light distribution pattern and the OHS light distribution pattern are significantly different, each light distribution pattern would normally be formed using a separate optical system. However, if an attempt were made to integrate two optical systems with different shapes to form a secondary optical member, molding the secondary optical member would be difficult.

[0012] In the present disclosure, the optical systems of the first and second exit surfaces are similarly configured, each having a cutoff line forming portion behind the first and second exit surfaces, making it easy to mold the secondary optical member. Furthermore, the present disclosure forms a light distribution pattern for OHS at the second exit surface, which has a focal point forward of the cutoff line forming portion. This provides a vehicle headlamp that is easy to mold and can simultaneously form a low-beam light distribution pattern and an OHS light distribution pattern.

[0013] a first optical system configured to illuminate a first illumination area including a first cutoff line; and a second optical system configured to illuminate a second illumination area including a second cutoff line, the second optical system being wider than the first illumination area and forming the low-beam light distribution pattern together with the first illumination area; the first optical system configured to illuminate a first incident surface, a first exit surface, and a first cutoff line forming portion configured to form the first cutoff line by totally reflecting a portion of light traveling from the first incident surface toward the first exit surface; the second optical system configured to illuminate a second incident surface, a second exit surface, and a second cutoff line forming portion configured to form the second cutoff line by totally reflecting a portion of light traveling from the second incident surface toward the second exit surface; and the second cutoff line forming portion configured to form a curve that is convex forward in top view.

[0014] According to the present disclosure, the lens component includes a first optical system that illuminates a first illumination area and a second optical system that illuminates a second illumination area that is wider than the first illumination area. Since each optical system has a similar configuration, the lens component is relatively easy to design.

[0015] Furthermore, when viewed from above, the second cutoff line forming portion of the second optical system is configured as a curve that is convex forward, so that the second optical system can irradiate the second irradiation area with reduced curvature of field.

[0016] According to the present disclosure, a vehicle headlamp that forms a plurality of light distribution patterns is provided while reducing the number of parts and the difficulty of molding optical members.

[0017] According to the present disclosure, a vehicle headlamp is provided in which lens components are easy to design and field curvature is suppressed.

[0018] FIG. 1 is a plan view illustrating an optical unit of a vehicle headlamp according to a first embodiment. FIG. 2 is a cross-sectional view of a secondary optical member of the optical unit taken along line II-II in FIG. 1 . FIG. 3 is a cross-sectional view of a secondary optical member of the optical unit taken along line III-III in FIG. 1 . FIG. 4 is a cross-sectional view illustrating how light emitted from a light source passes through the secondary optical member and is emitted to the outside. FIG. 5 is an enlarged view illustrating how light travels through the first and second emission surfaces of the secondary optical member. FIG. 6 is a plan view illustrating an optical unit of a vehicle headlamp according to a second embodiment. FIG. 7 is a cross-sectional view of a secondary optical member of the optical unit taken along line VII-VII in FIG. 6 . FIG. 8 is a diagram illustrating illumination areas formed by the first and second optical systems of the secondary optical member. FIG. 9 is a cross-sectional view of line IX-IX in FIG. 6 , illustrating how light emitted from a light source passes through the second optical system of the secondary optical member and is emitted to the outside.

[0019] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. For the sake of convenience, descriptions of components having the same reference numerals as those already described in the description of the embodiments will be omitted. Furthermore, for the sake of convenience, the dimensions of each component shown in the drawings may differ from the actual dimensions of each component.

[0020] Furthermore, in the description of this embodiment, for convenience of explanation, the terms "left-right direction," "up-down direction," and "front-rear direction" may be referred to as appropriate. These directions are relative directions set for the optical unit 1 of the vehicle headlight illustrated in FIG. 1 . Here, the "left-right direction" includes the "left direction" and the "right direction," and is also the width direction of the vehicle on which the optical unit 1 of the vehicle headlight is mounted. The "up-down direction" includes the "upward direction" and the "downward direction." The "front-rear direction" includes the "forward direction" and the "rearward direction." The front-rear direction is a direction perpendicular to the left-right direction and the up-down direction. Note that in each drawing, the symbol U indicates the upward direction. The symbol D indicates the downward direction. The symbol F indicates the forward direction. The symbol B indicates the rearward direction. The symbol L indicates the leftward direction. The symbol R indicates the rightward direction. The left-right direction is an example of the horizontal direction. (First Embodiment)

[0021] An optical unit 1 for a vehicle headlamp according to a first embodiment will be described with reference to Figures 1 to 3. The optical unit 1 is mounted in the vehicle headlamp and configured to form a low-beam light distribution pattern and an OHS light distribution pattern.

[0022] Fig. 1 is a plan view illustrating an optical unit 1 for a vehicle headlamp according to a first embodiment. Fig. 2 is a cross-sectional view of the secondary optical member 30 of the optical unit 1 taken along line II-II in Fig. 1. Fig. 3 is a cross-sectional view of the secondary optical member 30 of the optical unit 1 taken along line III-III in Fig. 1. As illustrated in Figs. 1 to 3, the optical unit 1 for a vehicle headlamp includes a light source 10, a primary optical member 20, and a secondary optical member 30. Each component will be described below.

[0023] The light source 10 is, for example, an LED (Light Emitting Diode) element or an LD (Laser Diode) element.

[0024] Primary optical member 20 is configured to collimate the light emitted from light source 10. Primary optical member 20 has a reflective surface 21 facing light source 10 (FIGS. 2 and 3). Reflective surface 21 collimates the light emitted from light source 10 and reflects it toward secondary optical member 30.

[0025] In the illustrated example, the primary optical member 20 is a parabolic reflector. The reflecting surface 21 is a paraboloid having an axis extending in the front-to-rear direction. The light source 10 is disposed on this axis. Light emitted from the light source 10 while diffusing toward the rear is reflected downward by the reflecting surface 21 as parallel light. The primary optical member 20 emits parallel light downward.

[0026] The secondary optical member 30 is formed of a transparent member that transmits light. The secondary optical member 30 is configured to guide the parallel light emitted from the primary optical member 20 toward the front of the vehicle. The secondary optical member 30 integrally includes an incident surface 31, a first exit surface 321, a second exit surface 322, a reflecting surface 33, and a cutoff line forming portion 34. The parallel light incident on the incident surface 31 is guided into the secondary optical member 30, reflected by the reflecting surface 33, and guided to the first exit surface 321 or the second exit surface 322.

[0027] The incident surface 31 is a surface onto which the parallel light emitted from the primary optical member 20 is incident. In this embodiment, at least a portion of the incident surface 31 is provided so as to face the reflecting surface 21 of the primary optical member 20.

[0028] The first exit surface 321 is provided on the front surface of the secondary optical member 30. The first exit surface 321 forms a single lens surface. The first exit surface 321 emits incident parallel light forward to form a low beam distribution pattern. A first focal position F321 of the first exit surface 321 is located near the cutoff line forming portion 34.

[0029] The second exit surface 322 is provided on the front surface of the secondary optical member 30. The second exit surface 322 forms a single lens surface. The second exit surface 322 emits incident parallel light forward to form an OHS (Over Head Sign) light distribution pattern. A second focal position F322 of the second exit surface 322 is located forward of the first focal position F321. For example, the radius of curvature of the lens surface of the second exit surface 322 is smaller than the radius of curvature of the lens surface of the first exit surface 321.

[0030] The first optical axis A1 of the first exit surface 321 and the second optical axis A2 of the second exit surface 322 extend parallel to each other.

[0031] The reflecting surface 33 is provided behind the first exit surface 321 and the second exit surface 322. The reflecting surface 33 has a total reflection surface that reflects the parallel light from the primary optical member 20 to each of the first exit surface 321 and the second exit surface 322. The total reflection surface of the reflecting surface 33 is configured to reflect the parallel light from the primary optical member 20 to each of the first exit surface 321 and the second exit surface 322 so that the parallel light is focused near the cutoff line forming portion 34.

[0032] The cutoff line forming portion 34 is provided behind each of the first exit surface 321 and the second exit surface 322. The cutoff line forming portion 34 is provided in front of the reflecting surface 33. The cutoff line forming portion 34 is configured to block a portion of the parallel light from the primary optical member 20 that is about to enter each of the first exit surface 321 and the second exit surface 322. Specifically, the cutoff line forming portion 34 is configured to totally reflect a portion of the light by a total reflection surface extending behind the cutoff line forming portion 34, thereby preventing the light from being emitted above the low beam distribution pattern. A cutoff line of the low beam distribution pattern can be formed by blocking a portion of the light by the cutoff line forming portion 34.

[0033] The cutoff line forming portion 34 is a step portion provided on the underside of the secondary optical member 30. The front portion of the underside of the secondary optical member 30 protrudes downward more than the rear portion. The cutoff line forming portion 34 is located at the boundary between the front and rear portions of the underside of this secondary optical member 30. A total reflection surface extends to the rear portion of the underside of the secondary optical member 30, which is located rearward of the boundary. When viewed from the front, the cutoff line forming portion 34 has a shape that corresponds to the cutoff line of the low-beam light distribution pattern. Furthermore, all of the multiple cutoff line forming portions 34 provided on the secondary optical member 30 have the same shape.

[0034] Next, the way light travels will be described. Figure 4 is a cross-sectional view illustrating the manner in which light emitted from light source 10 passes through secondary optical member 30 and is emitted to the outside. For convenience of explanation, light emitted from light source 10 and passing through the interior of secondary optical member 30 will be referred to as light L1. Here, L1 refers to light of relatively high intensity that is emitted from light source 10 at an emission angle smaller than a predetermined angle. In addition, first emission surface 321 is indicated by a dashed line, and second emission surface 322 is indicated by a solid line.

[0035] 4 , a portion of light L1 emitted from light source 10 is reflected by reflecting surface 21 of primary optical member 20 to become parallel light. The parallel light L1 is incident on incident surface 31 of secondary optical member 30, guided into the interior of secondary optical member 30, and reaches reflecting surface 33 at the rear of secondary optical member 30. Light L1 is reflected by reflecting surface 33 toward the front inside secondary optical member 30, toward each of first exit surface 321 and second exit surface 322.

[0036] 5 is an enlarged view illustrating how light travels through the first exit surface 321 and the second exit surface 322 of the secondary optical member 30. First, light L1 that reaches the first exit surface 321 will be described. A portion of light L1 reflected by the reflecting surface 33 passes near the cutoff line forming portion 34 and reaches the first exit surface 321. As light L1 passes near the cutoff line forming portion 34, a portion of light L1 is reflected by a total reflection surface extending rearward of the cutoff line forming portion 34 and reaches the first exit surface 321. In this way, a portion of light L1 reaches the first exit surface 321.

[0037] Since light L1 that has passed above cutoff line forming portion 34 reaches first exit surface 321, first exit surface 321 forms a low-beam light distribution pattern in which the upper part is blocked and the lower part is illuminated with light. Since cutoff line forming portion 34, which has a region that passes light and a boundary that does not pass light, has a stepped shape when viewed from the front, a step-shaped cutoff line is formed between the bright part and the dark part of the low-beam light distribution pattern.

[0038] Furthermore, the first focal position F321 of the first exit surface 321 is located in the vicinity of the cutoff line forming portion 34. Therefore, the first exit surface 321 emits the light L1 while relatively clearly reflecting the shape of the light L1 passing in the vicinity of the cutoff line forming portion 34 (a shape in which part of the light is totally reflected and another part passes through without being blocked). In this way, the secondary optical member 30 can form, by the first exit surface 321, a low-beam light distribution pattern in which the brightness difference of the cutoff line is clear.

[0039] Next, the light L1 that reaches the second exit surface 322 will be described. The light L1 that passes above the cutoff line forming portion 34 also reaches the second exit surface 322. Unlike the first exit surface 321, the second focal position F322 of the second exit surface 322 is located forward of the first focal position F321. Because the second focal position F322 is away from the cutoff line forming portion 34, the second exit surface 322 emits the light L1 that passes through the second focal position F322 in a relatively blurred state with low luminous intensity. In this way, the secondary optical member 30 can form an OHS light distribution pattern with a blurred outline and low luminous intensity by using the second exit surface 322.

[0040] As described above, the optical unit 1 of the vehicle lamp of this embodiment is an optical unit for a vehicle headlamp that forms a low-beam light distribution pattern and an OHS light distribution pattern. The optical unit 1 includes a light source 10, a primary optical element 20 that converts light emitted from the light source 10 into parallel light, and a secondary optical element 30 onto which the parallel light emitted from the primary optical element 20 is incident. The secondary optical element 30 integrally includes a first exit surface 321, a second exit surface 322, a reflecting surface 33, and a cutoff line forming portion 34. The first exit surface 321 emits a low-beam light distribution pattern. The second exit surface 322 emits an OHS light distribution pattern. The reflecting surface 33 reflects the parallel light to each of the first exit surface 321 and the second exit surface 322. The cutoff line forming portion 34 blocks a portion of the parallel light that is about to enter the first exit surface 321 and the second exit surface 322 behind each of the first exit surface 321 and the second exit surface 322. The reflecting surface 33 reflects the parallel light to each of the first exit surface 321 and the second exit surface 322 so that the parallel light is focused near the cutoff line forming portion 34. A first focal position F321 of the first exit surface 321 is located near the cutoff line forming portion 34, and a second focal position F322 of the second exit surface 322 is located forward of the first focal position F321.

[0041] Generally, the shapes of the low-beam light distribution pattern and the OHS light distribution pattern are significantly different, so each light distribution pattern is normally formed using a separate optical system. However, if an attempt is made to integrate two optical systems with different shapes to form a secondary optical member, molding the secondary optical member is difficult.

[0042] On the other hand, in this embodiment, the secondary optical member 30 is provided so that each optical system has the same configuration, with the cutoff line forming portion 34 provided behind the first exit surface 321 and the second exit surface 322, respectively. This makes it relatively easy to mold the secondary optical member 30. Additionally, in this embodiment, the light distribution pattern for OHS is formed on the second exit surface 322, which has a focal point forward of the cutoff line forming portion 34. This provides an optical unit 1 for a vehicle headlamp that is easy to mold and can simultaneously form the shape of a low-beam light distribution pattern and an OHS light distribution pattern.

[0043] Furthermore, because the OHS light distribution pattern does not require a clear outline and does not require as high a luminous intensity as a low-beam light distribution pattern, the OHS light distribution pattern may be a blurred image. The secondary optical member 30 of this embodiment constitutes another optical system including a second exit surface 322 that irradiates the OHS light distribution pattern, with a configuration similar to that of an optical system including a first exit surface 321 that irradiates the low-beam light distribution pattern. Furthermore, by shifting the second focal position F322 of the second exit surface 322 forward from the cutoff line forming portion 34, the OHS light distribution pattern can be irradiated by the second exit surface 322.

[0044] The second optical axis A2 of the second exit surface 322 may be located above the first optical axis A1 of the first exit surface 321. With this configuration, it becomes easier to emit an OHS light distribution pattern from the second exit surface 322 above the low-beam light distribution pattern emitted from the first exit surface 321.

[0045] The secondary optical element 30 of this embodiment has a plurality of first light exit surfaces 321 and a plurality of second light exit surfaces 322 (FIG. 1). Each of the first light exit surfaces 321 has the same configuration. Each of the second light exit surfaces 322 has the same configuration.

[0046] The first exit surface 321 and the second exit surface 322 are aligned in the left-right direction, and the second exit surface 322 may be located at a position other than the center in the left-right direction. The second exit surface 322 may also be located at an end in the left-right direction. For example, the secondary optical member 30 of this embodiment has eight exit surfaces aligned in the left-right direction. Of the multiple exit surfaces aligned in the left-right direction, the second exit surface 322 may be located at the right end located at the rightmost position or the left end located at the leftmost position. With this configuration, the second exit surface 322 can emit an OHS light distribution pattern with a relatively low luminous intensity.

[0047] The second light exit surface 322 may be located not only at the right end or the left end, but also to the right or left of the center. For example, if eight light exit surfaces are arranged in the left-right direction, the second light exit surface 322 may be located not only at the first position (right end) or the eighth position (left end), but also at the second position (the position adjacent to the right end to the left) or the seventh position (the position adjacent to the left end to the right). With this configuration, the second light exit surface 322 can emit a symmetrical OHS light distribution pattern while keeping the luminous intensity low.

[0048] One or more light sources 10 may be provided for one secondary optical member 30. The optical unit 1 of the vehicle headlamp may include one or more secondary optical members 30. (Second Embodiment)

[0049] 6 to 9, an optical unit 1X for a vehicle headlamp according to a second embodiment will be described. The optical unit 1X is mounted in a vehicle headlamp and configured to form a low-beam light distribution pattern LP ahead.

[0050] Fig. 6 is a plan view illustrating an optical unit 1X of a vehicle headlamp according to a second embodiment. In the configuration shown in Fig. 6, the same components as those shown in Fig. 1 are designated by the same reference numerals, and their description will be omitted. Fig. 7 is a cross-sectional view of the secondary optical member 30X of the optical unit 1X taken along line VII-VII in Fig. 6. In the configuration shown in Fig. 7, the same components as those shown in Fig. 2 are designated by the same reference numerals, and their description will be omitted.

[0051] 6 and 7, an optical unit 1X for a vehicle headlamp includes a light source 10, a primary optical member 20, and a secondary optical member 30X. The secondary optical member 30X is an example of a lens component.

[0052] The secondary optical member 30X integrally includes a first optical system 30A and a second optical system 30B arranged in the left-right direction. Fig. 8 is a diagram illustrating an example of an illumination area formed by each of the first optical system 30A and the second optical system 30B of the secondary optical member 30X. First, the configuration of the first optical system 30A will be described.

[0053] The first optical system 30A is configured to illuminate a first illumination region R1, which is a part of the low-beam distribution pattern LP. As illustrated in Fig. 7 , the first optical system 30A is provided below the primary optical member 20. The first optical system 30A integrally includes a first incident surface 31A, a first exit surface 32A, a first reflecting surface 33A, and a first cutoff line forming portion 34A. Parallel light incident on the first incident surface 31A is guided into the first optical system 30A, reflected by the first reflecting surface 33A, and guided to the first exit surface 32A.

[0054] The first incident surface 31A is a surface onto which the parallel light emitted from the primary optical member 20 is incident. In this embodiment, at least a portion of the first incident surface 31A is provided to face the reflecting surface 21 of the primary optical member 20. The first incident surface 31A is provided on the upper surface of the secondary optical member 30X.

[0055] The first light exit surface 32A is provided on the front surface of the secondary optical member 30X. The first light exit surface 32A forms a single lens surface that is convex forward. The first light exit surface 32A emits incident parallel light forward so as to form a first illumination region R1 of the low beam distribution pattern LP. The focal position of the first light exit surface 32A is located near the first cutoff line forming portion 34A.

[0056] The first reflecting surface 33A is provided behind the first exit surface 32A. The first reflecting surface 33A has a total reflection surface that reflects the parallel light from the primary optical member 20 to the first exit surface 32A. The total reflection surface of the first reflecting surface 33A is configured to reflect the parallel light from the primary optical member 20 to the first exit surface 32A so that the parallel light is focused near the first cutoff line forming portion 34A.

[0057] The first cutoff line forming portion 34A is provided between the first reflecting surface 33A and the first emitting surface 32A. The first cutoff line forming portion 34A is configured to totally reflect a portion of the light traveling from the first incident surface 31A toward the first emitting surface 32A. Specifically, the first cutoff line forming portion 34A is configured to totally reflect a portion of the light that is about to enter the first emitting surface 32A using a total reflection surface extending rearward of the first cutoff line forming portion 34A, thereby preventing the light from emitting above the low beam distribution pattern LP. The first cutoff line forming portion 34A blocks a portion of the light, thereby forming a first cutoff line CL1 in the first irradiation region R1 of the low beam distribution pattern LP.

[0058] The first cutoff line forming portion 34A is a step portion provided on the underside of the first optical system 30A. The front portion of the underside of the first optical system 30A protrudes downward more than the rear portion. The first cutoff line forming portion 34A is configured as a corner formed by the rear portion of the underside of the first optical system 30A and a surface extending between the front and rear portions (surfaces extending in the up-down and left-right directions). The rear portion of the underside of the first optical system 30A extending rearward from this corner is a total reflection surface. When viewed from the front, the first cutoff line forming portion 34A has a shape corresponding to the first cutoff line CL1 of the low-beam light distribution pattern LP.

[0059] Next, the second optical system 30B will be described. As illustrated in Fig. 8, the second optical system 30B is configured to irradiate a second irradiation region R2, which is a part of the low-beam light distribution pattern LP. The second irradiation region R2 is wider than the first irradiation region R1 at least in the left-right direction. The first irradiation region R1 and the second irradiation region R2 partially overlap each other to form the low-beam light distribution pattern LP.

[0060] The second optical system 30B integrally includes a second incident surface 31B, a second exit surface 32B, a second reflecting surface 33B, and a second cutoff line forming portion 34B. The parallel light incident on the second incident surface 31B is guided into the second optical system 30B, reflected by the second reflecting surface 33B, and guided to the second exit surface 32B.

[0061] Except for the second cutoff line forming portion 34B, the configuration of the second optical system 30B is substantially the same as the configuration of the first optical system 30A. However, in order to make the second irradiation region R2 wider than the first irradiation region R1, at least one of the shape of the second emission surface 32B and the shape of the second reflecting surface 33B is different from the shape of the first emission surface 32A and the shape of the first reflecting surface 33A. The second emission surface 32B is also a single lens surface that is convex forward.

[0062] The second cutoff line forming portion 34B is provided between the second reflecting surface 33B and the second emitting surface 32B. The second cutoff line forming portion 34B is configured to totally reflect a portion of the light traveling from the second incident surface 31B toward the second emitting surface 32B. Specifically, the second cutoff line forming portion 34B is configured to totally reflect a portion of the light that is about to enter the second emitting surface 32B using a total reflection surface extending rearward of the second cutoff line forming portion 34B, thereby preventing the light from emitting above the low beam distribution pattern LP. The second cutoff line forming portion 34B blocks a portion of the light, thereby forming a second cutoff line CL2 in the second irradiation region R2 of the low beam distribution pattern LP.

[0063] The second cutoff line forming portion 34B is a step portion provided on the lower surface of the second optical system 30B. The front portion of the lower surface of the second optical system 30B protrudes downward more than the rear portion. The second cutoff line forming portion 34B is configured as a corner formed by the rear portion of the lower surface of the second optical system 30B and a surface extending between the front and rear portions (surfaces extending in the up-down and left-right directions). The rear portion of the lower surface of the second optical system 30B extending rearward from this corner is a total reflection surface. When viewed from the front, the second cutoff line forming portion 34B has a shape corresponding to the second cutoff line CL2 of the low-beam light distribution pattern LP.

[0064] In a top view, the second cutoff line forming portion 34B is configured as a curve that convexly extends forward (FIG. 6). The radius of curvature of the second cutoff line forming portion 34B is set to a value corresponding to the radius of curvature of the second light exit surface 32B.

[0065] Next, the way light travels will be described. The way light travels through the first optical system 30A and the way light travels through the second optical system 30B are basically the same. Below, the way light travels through the second optical system 30B will be described, and a description of the way light travels through the first optical system 30A will be omitted.

[0066] 9 is a cross-sectional view taken along the arrows IX-IX in FIG. 6 , illustrating how light emitted from the light source 10 passes through the second optical system 30B of the secondary optical member 30X and is emitted to the outside. For convenience of explanation, light emitted from the light source 10 and passing through the second optical system 30B is referred to as light L1. Here, L1 refers to light of relatively high intensity that is emitted from the light source 10 at an emission angle smaller than a predetermined angle.

[0067] 9 , a portion of light L1 emitted from light source 10 is reflected by reflecting surface 21 of primary optical member 20 to become parallel light. The parallel light L1 is incident on second incident surface 31B of second optical system 30B of secondary optical member 30X, guided into the second optical system 30B, and reaches second reflecting surface 33B at the rear of second optical system 30B. Light L1 is reflected by second reflecting surface 33B to second exit surface 32B toward the front inside second optical system 30B.

[0068] A portion of the light L1 reflected by the second reflecting surface 33B passes near the second cutoff line forming portion 34B and reaches the second exit surface 32B. When the light L1 passes near the second cutoff line forming portion 34B, a portion of the light L1 is reflected by a total reflection surface extending rearward of the second cutoff line forming portion 34B. A portion of the light L1 that passes above the second cutoff line forming portion 34B reaches the second exit surface 32B.

[0069] Because the light L1 that has passed above the second cutoff line forming portion 34B reaches the second exit surface 32B, the second exit surface 32B forms a second irradiation region R2 of the low-beam light distribution pattern LP, where the upper portion is light-shielded and the lower portion is light-irradiated. The second cutoff line forming portion 34B, which has a region that transmits light and a boundary that does not transmit light, has a stepped shape when viewed from the front, so a stepped second cutoff line CL2 is formed between the bright portion and the dark portion of the second irradiation region R2.

[0070] The second optical system 30B may be configured so that a portion of the light L1 reflected by the total reflection surface extending behind the second cutoff line forming portion 34B is incident on the second exit surface 32B, and the light is irradiated onto a region below the second cutoff line CL2, thereby improving the light utilization efficiency.

[0071] As described above, the optical unit 1X of the vehicle lamp of this embodiment is an optical unit for a vehicle headlamp that forms a low-beam light distribution pattern LP forward. The optical unit 1X includes a light source 10 and a secondary optical member 30X that integrally includes a plurality of optical systems arranged in the left-right direction. The secondary optical member 30X includes a first optical system 30A and a second optical system 30B. The first optical system 30A irradiates a first irradiation region R1 that includes a first cutoff line CL1. The second optical system 30B irradiates a second irradiation region R2 that includes a second cutoff line CL2, is wider than the first irradiation region R1, and forms the low-beam light distribution pattern LP together with the first irradiation region R1. The first optical system 30A includes a first incident surface 31A, a first exit surface 32A, and a first cutoff line forming portion 34A that totally reflects a portion of light traveling from the first incident surface 31A toward the first exit surface 32A to form the first cutoff line CL1. The second optical system 30B has a second incident surface 31B, a second exit surface 32B, and a second cutoff line forming portion 34B that totally reflects a portion of light traveling from the second incident surface 31B toward the second exit surface 32B to form a second cutoff line CL2. In a top view, the second cutoff line forming portion 34B is configured as a curve that is convex forward.

[0072] The low-beam light distribution pattern LP of a vehicle headlamp is long in the left-right direction. Therefore, when a low-beam light distribution pattern LP is formed using a relatively large projection lens as in the past, the left-right ends of the low-beam light distribution pattern LP may be positioned upward, resulting in a problem of field curvature. However, as in the optical unit 1X of the vehicle headlamp of this embodiment, the secondary optical member 30X, which integrally includes the first optical system 30A and the second optical system 30B, is relatively small, and therefore its first exit surface 32A and second exit surface 32B are also small. Therefore, it has generally been thought that the optical unit 1X of a vehicle headlamp equipped with such an optical system is less likely to suffer from the problem of field curvature.

[0073] However, in the optical unit 1X for a vehicle headlamp of this embodiment, the low-beam light distribution pattern LP is formed by a first illumination region R1 and a wider second illumination region R2. The second illumination region R2 tends to be an extremely flat illumination region in the left-right direction, which makes the problem of field curvature more likely to occur at the left-right ends. Therefore, in the optical unit 1X for a vehicle headlamp of this embodiment, the second cutoff line forming portion 34B that forms at least the second illumination region R2 is configured with a forward-convex curve to match the forward-convex lens surface of the second exit surface 32B, so as to reduce the occurrence of field curvature. This provides an optical unit 1X for a vehicle headlamp that is less likely to experience field curvature.

[0074] The secondary optical member 30X of the present disclosure is configured to include multiple integrated optical systems to emit multiple light distribution patterns (first illumination region R1 and second illumination region R2) that are different from each other, which increases the difficulty of designing the secondary optical member 30X. Furthermore, if an attempt is made to solve the problem of field curvature for all optical systems, the difficulty of designing the secondary optical member 30X increases even further.

[0075] Therefore, the first cutoff line forming portion 34A may be configured linearly in a top view ( FIG. 6 ). Because the horizontal dimension of at least the first illumination region R1 is not large, the problem of field curvature is unlikely to occur in the first illumination region R1. The inventors considered the characteristics of each illumination region and considered that the problem of field curvature and the design difficulty could be balanced for the secondary optical member 30X as a whole by prioritizing reducing the design difficulty of the first optical system 30A over the problem of field curvature, and prioritizing suppressing the problem of field curvature for the second optical system 30B, even if this increases the design difficulty. This provides an optical unit 1X for a vehicle headlamp that is easy to design and suppresses the problem of field curvature.

[0076] The first cutoff line forming portion 34A may be configured as a curved line that is convex forward. With this configuration, distortion of the first cutoff line CL1 due to the curvature of field of the first exit surface 32A is reduced compared to when the first cutoff line forming portion 34A is configured as a straight line.

[0077] The secondary optical member 30X of this embodiment may have a plurality of first optical systems 30A and a plurality of second optical systems 30B (FIG. 6). Each of the first optical systems 30A has the same configuration. Each of the second optical systems 30B has the same configuration.

[0078] The first optical system 30A and the second optical system 30B are aligned in the left-right direction, and the second optical system 30B may be positioned outward of the first optical system 30A in the left-right direction when viewed from above. The second optical system 30B may be positioned at an end in the left-right direction. For example, the secondary optical member 30X of this embodiment has two first optical systems 30A and two second optical systems 30B aligned in the left-right direction. Of the multiple optical systems aligned in the left-right direction, the second optical system 30B may be positioned at the right end located at the rightmost position or the left end located at the leftmost position. With this configuration, the second optical system 30B can form a wide second irradiation region R2 with a relatively low luminous intensity.

[0079] One or more light sources 10 may be provided for one secondary optical member 30X. The optical unit 1X of the vehicle headlamp may include one or more secondary optical members 30X.

[0080] Although the embodiments of the present disclosure have been described above, it goes without saying that the technical scope of the present disclosure should not be interpreted as being limited by the description of the present embodiments. The present embodiments are merely examples, and it will be understood by those skilled in the art that various modifications of the embodiments are possible within the scope of the disclosure described in the claims. The technical scope of the present disclosure should be determined based on the scope of the disclosure described in the claims and its equivalents.

[0081] The configurations described in the following items also constitute part of the present disclosure. Item 1: A vehicle headlamp that forms a low-beam light distribution pattern and an OHS light distribution pattern, comprising: a light source; a primary optical member that converts light emitted from the light source into parallel light; and a secondary optical member onto which the parallel light emitted from the primary optical member is incident, wherein the secondary optical member integrally includes: a first emission surface that irradiates a low-beam light distribution pattern; a second emission surface that irradiates an OHS light distribution pattern; a reflecting surface that reflects the parallel light to each of the first emission surface and the second emission surface; and a cutoff line forming portion behind each of the first emission surface and the second emission surface that blocks a part of the parallel light that is about to be incident on the first emission surface and the second emission surface, A vehicle headlamp, wherein a first focal position of the first exit surface is located near the cutoff line forming portion, and a second focal position of the second exit surface is located forward of the first focal position. Item 2: The vehicle headlamp according to Item 1, wherein an optical axis of the second exit surface is located above the optical axis of the first exit surface. Item 3: The vehicle headlamp according to Item 1 or 2, wherein the first exit surface and the second exit surface are aligned in the left-right direction, and the second exit surface is located other than at the center in the left-right direction. Item 4: The vehicle headlamp according to any one of Items 1 to 3, wherein the first exit surface and the second exit surface are aligned in the left-right direction, and the second exit surface is located at an end in the left-right direction.

[0082] This application claims priority based on Japanese Application No. 2024-063144 filed on April 10, 2024 and Japanese Application No. 2024-073615 filed on April 30, 2024, and incorporates all of the contents of the aforementioned Japanese applications by reference.

Claims

1. A vehicle headlamp that forms a low-beam light distribution pattern and an OHS light distribution pattern, comprising: a light source; a primary optical element that converts light emitted from the light source into parallel light; and a secondary optical element onto which the parallel light emitted from the primary optical element is incident, wherein the secondary optical element integrally includes: a first emission surface that irradiates a low-beam light distribution pattern; a second emission surface that irradiates an OHS light distribution pattern; a reflecting surface that reflects the parallel light to each of the first emission surface and the second emission surface; and a cutoff line forming portion behind each of the first emission surface and the second emission surface that blocks a part of the parallel light that is about to enter the first emission surface and the second emission surface, wherein the reflecting surface reflects the parallel light to each of the first emission surface and the second emission surface so as to form a focus in the vicinity of the cutoff line forming portion, a first focal position of the first exit surface is located near the cutoff line forming portion, and a second focal position of the second exit surface is located forward of the first focal position.

2. The vehicle headlamp according to claim 1, wherein the optical axis of the second light exit surface is positioned above the optical axis of the first light exit surface.

3. The vehicle headlamp according to claim 1, wherein the first light exit surface and the second light exit surface are aligned in the left-right direction, and the second light exit surface is positioned other than at the center in the left-right direction.

4. The vehicle headlamp according to claim 1, wherein the first light exit surface and the second light exit surface are aligned in the left-right direction, and the second light exit surface is located at an end in the left-right direction.

5. A vehicle headlamp that forms a low-beam light distribution pattern forward, comprising: a light source; and a lens component integrally comprising a plurality of optical systems arranged in the left-right direction, wherein the lens component comprises: a first optical system that irradiates a first illumination area including a first cutoff line; and a second optical system that irradiates a second illumination area that includes a second cutoff line, is wider than the first illumination area, and forms the low-beam light distribution pattern together with the first illumination area, wherein the first optical system has a first incident surface, a first exit surface, and a first cutoff line forming portion that forms the first cutoff line by totally reflecting a portion of the light that travels from the first incident surface to the first exit surface, and wherein the second optical system has a second incident surface, a second exit surface, and a second cutoff line forming portion that forms the second cutoff line by totally reflecting a portion of the light that travels from the second incident surface to the second exit surface, wherein the second cutoff line forming portion is configured as a curve that is convex forward in top view.

6. The vehicle headlamp according to claim 5, wherein the first cutoff line forming portion is configured to have a linear shape in the top view.

7. The vehicle headlamp according to claim 5 or 6, wherein the second optical system is disposed outward in the left-right direction from the first optical system when viewed from above.

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