WO2025216043A1 - Vehicle headlight - Google Patents

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

This disclosure relates to a vehicle headlamp.

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

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

Japan Special Table Publication No. 2016-534503 International Publication No. 2023/243345

When creating 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.

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

However, in recent years, there has been a demand for more precise light distribution patterns. For this reason, there is also a need to suppress field curvature in vehicle headlights that incorporate lens components.

One of the objectives of this disclosure is to provide a vehicle headlamp that forms multiple light distribution patterns while reducing the number of parts and the difficulty of molding optical components.

Another object of this disclosure is to provide a vehicle headlamp with reduced field curvature.

A vehicle headlamp according to one aspect of the present disclosure includes:
A vehicle headlamp that forms a low beam light distribution pattern and an OHS light distribution pattern,
A light source and
a primary optical member that converts light emitted from the light source into parallel light;
a secondary optical member onto which the parallel light emitted from the primary optical member is incident,
The secondary optical member is
a first exit surface that emits a low beam light distribution pattern;
a second exit surface that emits an OHS light distribution pattern;
a reflecting surface that reflects the parallel light to each of the first exit surface and the second exit surface;
a cutoff line forming portion that blocks a part of the parallel light that is about to be incident on the first exit surface and the second exit surface, respectively, is integrally provided behind the first exit surface and the second exit surface,
the reflecting surface reflects the parallel light to each of the first exit surface and the second exit 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.

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 separate optical systems. However, if two optical systems with different shapes are integrated to form a secondary optical element, molding the secondary optical element would be difficult.

In the present disclosure, the optical systems have the same configuration, with cutoff line forming sections behind the first and second exit surfaces, respectively, making it easy to mold the secondary optical element. Furthermore, in the present disclosure, a light distribution pattern for OHS is formed at the second exit surface, which has a focal point forward of the cutoff line forming section. This provides 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.

A vehicle headlamp according to another aspect of the present disclosure includes:
A vehicle headlamp that forms a low beam light distribution pattern forward,
A light source and
a lens component integrally including a plurality of optical systems arranged in the left-right direction;
The lens component includes:
a first optical system that illuminates a first illumination area including a first cutoff line;
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;
the first optical system includes a first incident surface, a first exit surface, and a first cutoff line forming unit that totally reflects a part of light traveling from the first incident surface to the first exit surface to form the first cutoff line,
the second optical system includes a second incident surface, a second exit surface, and a second cutoff line forming unit that totally reflects a portion of light traveling from the second incident surface toward the second exit surface to form the second cutoff line,
In a top view, the second cutoff line forming portion is configured as a curve that convex forward.

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. Because each optical system has a similar configuration, the lens component is relatively easy to design.

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. This allows the second optical system to illuminate the second illumination area with reduced field curvature.

This disclosure provides a vehicle headlamp that forms multiple light distribution patterns while reducing the number of parts and the difficulty of molding optical components.

This disclosure provides a vehicle headlamp that allows for easy design of lens components and suppresses field curvature.

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

Embodiments of the present disclosure will be described below with reference to the drawings. Note that for the sake of convenience, descriptions of components with the same reference numbers as components 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.

Furthermore, in the description of this embodiment, for convenience of explanation, the terms "left-right direction,""up-downdirection," 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 vehicle 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)

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

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 comprises a light source 10, a primary optical member 20, and a secondary optical member 30. Each component will be described below.

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

The primary optical element 20 is configured to collimate the light emitted from the light source 10. The primary optical element 20 has a reflecting surface 21 facing the light source 10 (Figures 2 and 3). The reflecting surface 21 collimates the light emitted from the light source 10 and reflects it toward the secondary optical element 30.

In the illustrated example, the primary optical element 20 is a parabolic reflector. The reflecting surface 21 is a parabolic surface with an axis extending in the front-to-rear direction. The light source 10 is positioned on this axis. Light emitted from the light source 10 while diffusing rearward is reflected downward by the reflecting surface 21 as parallel light. The primary optical element 20 emits parallel light downward.

The secondary optical element 30 is formed from a transparent element that transmits light. The secondary optical element 30 is configured to guide the parallel light emitted from the primary optical element 20 toward the front of the vehicle. The secondary optical element 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 element 30, reflected by the reflecting surface 33, and guided to the first exit surface 321 or the second exit surface 322.

The incident surface 31 is the 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 arranged to face the reflecting surface 21 of the primary optical member 20.

The first exit surface 321 is provided on the front surface of the secondary optical element 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 light distribution pattern. The first focal position F321 of the first exit surface 321 is located near the cutoff line forming portion 34.

The second exit surface 322 is provided on the front surface of the secondary optical element 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. The second focal position F322 of the second exit surface 322 is located further forward than 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.

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.

The reflecting surface 33 is located 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 element 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 element 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.

The cutoff line forming section 34 is provided behind each of the first exit surface 321 and the second exit surface 322. The cutoff line forming section 34 is provided in front of the reflecting surface 33. The cutoff line forming section 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 section 34 is configured to totally reflect a portion of the light using a total reflection surface extending behind the cutoff line forming section 34, preventing the light from being emitted above the low beam light distribution pattern. A cutoff line for the low beam light distribution pattern can be formed by blocking a portion of the light by the cutoff line forming section 34.

The cutoff line forming portion 34 is a step provided on the underside of the secondary optical element 30. The front portion of the underside of the secondary optical element 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 element 30. A total reflection surface extends to the rear portion of the underside of the secondary optical element 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 element 30 have the same shape.

Next, the way light travels will be explained.
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 ease of explanation, light emitted from light source 10 and passing through the interior of secondary optical member 30 is 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.

As illustrated in Figure 4, a portion of light L1 emitted from the light source 10 is reflected by the reflecting surface 21 of the primary optical element 20 and becomes parallel light. The parallel light L1 is incident on the incident surface 31 of the secondary optical element 30, guided inside the secondary optical element 30, and reaches the reflecting surface 33 at the rear of the secondary optical element 30. The light L1 is reflected by the reflecting surface 33 toward the front of the interior of the secondary optical element 30, toward each of the first exit surface 321 and the second exit surface 322.

FIG. 5 is an enlarged view for explaining how light travels through the first exit surface 321 and the second exit surface 322 of the secondary optical member 30. As shown in FIG.
First, the light L1 that reaches the first light exit surface 321 will be described.
A portion of the light L1 reflected by the reflecting surface 33 passes near the cutoff line forming portion 34 and reaches the first exit surface 321. When the light L1 passes near the cutoff line forming portion 34, a portion of the 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 the light L1 reaches the first exit surface 321.

Because light L1 that passes above the cutoff line forming portion 34 reaches the first exit surface 321, the first exit surface 321 forms a low beam light distribution pattern in which the upper portion is blocked and light is irradiated to the lower portion. The cutoff line forming portion 34, which has an area that allows light to pass and a boundary that prevents light from passing through, has a stepped shape when viewed from the front, so a stepped cutoff line is formed between the bright and dark areas of the low beam light distribution pattern.

Furthermore, the first focal position F321 of the first exit surface 321 is located near the cutoff line forming portion 34. Therefore, the first exit surface 321 emits light L1 while relatively clearly reflecting the shape of the light L1 passing near 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 element 30 can form a low-beam light distribution pattern with a clear difference in brightness and darkness of the cutoff line by using the first exit surface 321.

Next, the light L1 that reaches the second light exit surface 322 will be described.
The light L1 that has passed 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 has passed through the second focal position F322 in a relatively blurred state and 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.

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 comprises a light source 10, a primary optical element 20 that converts the 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 has 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 collimated 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 collimated light to each of the first exit surface 321 and the second exit surface 322 so that the 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.

Generally, the shapes of low-beam light distribution patterns and OHS light distribution patterns are significantly different, so ideally each would be formed using a separate optical system. However, if two optical systems with different shapes are integrated to form a secondary optical element, molding the secondary optical element is difficult.

In contrast, in this embodiment, the secondary optical element 30 is provided so that each optical system has a similar configuration, with a cutoff line forming portion 34 provided behind each of the first and second exit surfaces 321 and 322. This makes it relatively easy to mold the secondary optical element 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.

Furthermore, because an 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 element 30 of this embodiment constitutes another optical system including a second exit surface 322 that irradiates an OHS light distribution pattern, with a configuration similar to that of an optical system including a first exit surface 321 that irradiates a 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.

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. This configuration makes it 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.

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

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 in 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 element 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.

The second exit surface 322 may not only be located at the right or left end, but may also be located to the right or left of the center. For example, if eight exit surfaces are arranged in the left-right direction, the second 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 exit surface 322 can emit a symmetrical OHS light distribution pattern while keeping the luminous intensity low.

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

With reference to Figures 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 is configured to form a low-beam light distribution pattern LP ahead.

FIG. 6 is a plan view illustrating an optical unit 1X for 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.

As illustrated in Figures 6 and 7, the 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.

The secondary optical element 30X integrally comprises a first optical system 30A and a second optical system 30B arranged in the left-right direction. Figure 8 is a diagram illustrating the illumination areas formed by the first optical system 30A and the second optical system 30B of the secondary optical element 30X. First, the configuration of the first optical system 30A will be described.

The first optical system 30A is configured to illuminate a first illumination region R1, which is 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.

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 arranged to face the reflecting surface 21 of the primary optical member 20. The first incident surface 31A is arranged on the upper surface of the secondary optical member 30X.

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

The first reflecting surface 33A is located 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 element 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 element 20 to the first exit surface 32A so that the parallel light is focused near the first cutoff line forming portion 34A.

The first cutoff line forming portion 34A is provided between the first reflecting surface 33A and the first exit surface 32A. The first cutoff line forming portion 34A is configured to totally reflect a portion of the light traveling from the first entrance surface 31A toward the first exit 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 exit surface 32A using a total reflection surface extending rearward of the first cutoff line forming portion 34A, preventing the light from emitting above the low beam distribution pattern LP. By blocking a portion of the light by the first cutoff line forming portion 34A, a first cutoff line CL1 in the first illumination region R1 of the low beam distribution pattern LP can be formed.

The first cutoff line forming portion 34A is a step 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 this first optical system 30A and a surface extending between the front and rear portions (surfaces extending in the vertical and horizontal 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 that corresponds to the first cutoff line CL1 of the low beam distribution pattern LP.

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

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. 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.

Except for the second cutoff line forming section 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 reflection surface 33B differs from the shape of the first emission surface 32A and the shape of the first reflection surface 33A. The second emission surface 32B is also a single lens surface that is convex forward.

The second cutoff line forming portion 34B is provided between the second reflecting surface 33B and the second exit surface 32B. The second cutoff line forming portion 34B is configured to totally reflect a portion of the light traveling from the second entrance surface 31B toward the second exit 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 exit surface 32B using a total reflection surface extending rearward of the second cutoff line forming portion 34B, thereby preventing the light from being emitted above the low beam distribution pattern LP. As a portion of the light is blocked by the second cutoff line forming portion 34B, a second cutoff line CL2 in the second irradiation region R2 of the low beam distribution pattern LP is formed.

The second cutoff line forming portion 34B is a step provided on the underside of the second optical system 30B. The front portion of the underside 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 underside of this second optical system 30B and a surface extending between the front and rear portions (surfaces extending in the vertical and horizontal directions). The rear portion of the underside 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 that corresponds to the second cutoff line CL2 of the low beam distribution pattern LP.

In top view, the second cutoff line forming portion 34B is configured as a curve that convexly faces forward (Figure 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 emission surface 32B.

Next, we will explain how light travels. 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, we will explain how light travels through the second optical system 30B, and will omit an explanation of how light travels through the first optical system 30A.

Figure 9 is a cross-sectional view taken along the arrows IX-IX in Figure 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 ease of explanation, light emitted from the light source 10 and passing through the inside of 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.

As illustrated in Figure 9, a portion of light L1 emitted from the light source 10 is reflected by the reflecting surface 21 of the primary optical element 20 and becomes parallel light. The parallel light L1 is incident on the second incident surface 31B of the second optical element 30B of the secondary optical element 30X, is guided inside the second optical element 30B, and reaches the second reflecting surface 33B at the rear of the second optical element 30B. The light L1 is reflected by the second reflecting surface 33B to the second exit surface 32B toward the front inside the second optical element 30B.

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. As 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 behind 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.

Because light L1 that passes 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 distribution pattern LP, with the upper portion blocked and the lower portion illuminated. The second cutoff line forming portion 34B, which has a region that passes light and a boundary that does not pass light, has a stepped shape when viewed from the front, so a stepped second cutoff line CL2 is formed between the bright and dark portions of the second irradiation region R2.

The second optical system 30B may be configured to direct a portion of the light L1 reflected by the total reflection surface extending rearward of the second cutoff line forming portion 34B to the second exit surface 32B, so that the light is irradiated onto an area below the second cutoff line CL2. This improves the light utilization efficiency.

As described above, the optical unit 1X of the vehicle lamp of this embodiment is an optical unit of a vehicle headlamp that forms a low-beam light distribution pattern LP forward. The optical unit 1X has a light source 10 and a secondary optical element 30X that integrally comprises multiple optical elements arranged in the left-right direction. The secondary optical element 30X includes a first optical element 30A and a second optical element 30B. The first optical element 30A illuminates a first illumination region R1 that includes a first cutoff line CL1. The second optical element 30B illuminates a second illumination region R2 that includes a second cutoff line CL2, is wider than the first illumination region R1, and forms the low-beam light distribution pattern LP together with the first illumination region R1. The first optical element 30A has a first incident surface 31A, a first exit surface 32A, and a first cutoff line forming portion 34A that totally reflects a portion of the 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 forms a second cutoff line CL2 by totally reflecting a portion of the light traveling from the second incident surface 31B to the second exit surface 32B. In a top view, the second cutoff line forming portion 34B is configured as a curve that convexly faces forward.

The low-beam light distribution pattern LP of a vehicle headlamp is long in the left-right direction. For this reason, 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 can be positioned upward, resulting in a problem of field curvature. However, as in the vehicle headlamp optical unit 1X of this embodiment, the secondary optical member 30X, which integrally comprises 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. For this reason, it has generally been thought that a vehicle headlamp optical unit 1X equipped with such an optical system is less likely to suffer from field curvature problems.

However, in the optical unit 1X for a vehicle headlamp of this embodiment, the low beam light distribution pattern LP is formed by the first illumination region R1 and the wider second illumination region R2. The second illumination region R2 tends to be an illumination region that is extremely flat in the left-right direction, making it easy for problems with field curvature to occur at the left and 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 that field curvature is less likely to occur. This provides an optical unit 1X for a vehicle headlamp that is less likely to cause field curvature.

Furthermore, the secondary optical member 30X of the present disclosure is configured to include multiple integrated optical systems in order 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 one were to try to resolve the problem of field curvature for all optical systems, the difficulty of designing would increase even further.

Therefore, the first cutoff line forming portion 34A may be configured to be linear when viewed from above (Figure 6). Because the horizontal dimension of at least the first illuminated region R1 is not large, the problem of field curvature is unlikely to occur in the first illuminated region R1. The inventors focused on the characteristics of each illuminated region and determined that 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 it increases the design difficulty, it would be possible to balance the problem of field curvature and the design difficulty for the secondary optical member 30X as a whole. This provides an optical unit 1X for a vehicle headlamp that is easy to design and suppresses the problem of field curvature.

The first cutoff line forming portion 34A may be configured as a curved line that convex forward. With this configuration, distortion of the first cutoff line CL1 due to 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.

The secondary optical element 30X of this embodiment may have multiple first optical systems 30A and multiple second optical systems 30B (Figure 6). Each of the first optical systems 30A has the same configuration. Each of the second optical systems 30B has the same configuration.

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 outboard 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.

One or more light sources 10 may be provided for one secondary optical element 30X. The optical unit 1X of the vehicle headlamp may include one or more secondary optical elements 30X.

The above describes an embodiment of the present disclosure, but it goes without saying that the technical scope of the present disclosure should not be interpreted as being limited by the description of this embodiment. This embodiment is merely an example, and it will be understood by those skilled in the art that various modifications to the embodiment 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 the scope of equivalents thereof.

The configurations described in each item listed below also constitute part of this disclosure.
Item 1:
A vehicle headlamp that forms a low beam light distribution pattern and an OHS light distribution pattern,
A light source and
a primary optical member that converts light emitted from the light source into parallel light;
a secondary optical member onto which the parallel light emitted from the primary optical member is incident,
The secondary optical member is
a first exit surface that emits a low beam light distribution pattern;
a second exit surface that emits an OHS light distribution pattern;
a reflecting surface that reflects the parallel light to each of the first exit surface and the second exit surface;
a cutoff line forming portion that blocks a part of the parallel light that is about to be incident on the first exit surface and the second exit surface, respectively, is integrally provided behind the first exit surface and the second exit surface,
the reflecting surface reflects the parallel light to each of the first exit surface and the second exit 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.
Item 2:
Item 2. The vehicle headlamp according to item 1, wherein an optical axis of the second light exit surface is positioned above an optical axis of the first light exit surface.
Item 3:
the first exit surface and the second exit surface are aligned in the left-right direction,
3. The vehicle headlamp according to claim 1, wherein the second light exit surface is positioned other than at the center in the left-right direction.
Item 4:
the first exit surface and the second exit surface are aligned in the left-right direction,
4. The vehicle headlamp according to claim 1, wherein the second light exit surface is located at an end in the left-right direction.

This application claims priority to Japanese Patent Application No. 2024-063144, filed April 10, 2024, and Japanese Patent Application No. 2024-073615, filed April 30, 2024, and incorporates all of the contents of those Japanese applications by reference.

Claims (7)

A vehicle headlamp that forms a low beam light distribution pattern and an OHS light distribution pattern,
A light source and
a primary optical member that converts light emitted from the light source into parallel light;
a secondary optical member onto which the parallel light emitted from the primary optical member is incident,
The secondary optical member is
a first exit surface that emits a low beam light distribution pattern;
a second exit surface that emits an OHS light distribution pattern;
a reflecting surface that reflects the parallel light to each of the first exit surface and the second exit surface;
a cutoff line forming portion that blocks a part of the parallel light that is about to be incident on the first exit surface and the second exit surface, respectively, is integrally provided behind the first exit surface and the second exit surface,
the reflecting surface reflects the parallel light to each of the first exit surface and the second exit 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. 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. the first exit surface and the second exit surface are aligned in the left-right direction,
The vehicle headlamp according to claim 1 , wherein the second light exit surface is positioned other than at the center in the left-right direction. the first exit surface and the second exit surface are aligned in the left-right direction,
The vehicle headlamp according to claim 1 , wherein the second light exit surface is located at an end in the left-right direction. A vehicle headlamp that forms a low beam light distribution pattern forward,
A light source and
a lens component integrally including a plurality of optical systems arranged in the left-right direction;
The lens component includes:
a first optical system that illuminates a first illumination area including a first cutoff line;
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;
the first optical system includes a first incident surface, a first exit surface, and a first cutoff line forming unit that totally reflects a part of light traveling from the first incident surface to the first exit surface to form the first cutoff line,
the second optical system includes a second incident surface, a second exit surface, and a second cutoff line forming unit that totally reflects a portion of light traveling from the second incident surface toward the second exit surface to form the second cutoff line,
A vehicle headlamp, wherein the second cutoff line forming portion is configured as a curve that convex forward when viewed from above. The vehicle headlamp according to claim 5, wherein the first cutoff line forming portion is configured in a linear shape when viewed from above. 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.