Vehicle headlight

Abstract

An optical unit (1) of a vehicle headlight that forms a low beam light distribution pattern (LP) comprises: a light source (10); a primary optical member (20) that renders light emitted from the light source (10) parallel light; and a light guide body (30) into which the parallel light emitted from the primary optical member (20) is incident. The light guide body (30) has: an emission surface (32) that is provided on the front side of the light guide body (30) and that emits light so as to form the low beam light distribution pattern (LP); and a reflection part (33) which is provided as a total reflection surface on the light guide body (30) and according to which light from the primary optical member (20) is directed into the light guide body (30) and either directly or indirectly reflected to the emission surface (32). The reflection part (33) is composed of a plurality of mutually different reflection surfaces (331, 332).

Description

Vehicle headlights

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

[0002] Patent Document 1 discloses a vehicle headlamp that forms a low-beam light distribution pattern. The vehicle headlamp includes a light source and a light guide that guides light from the light source toward the front of the vehicle. A reflector is formed on at least a portion of the surface of the light guide, has an optical center near the light source, and reflects light incident from the light source through the light guide. A lens is formed integrally with the light guide and deflects the light reflected by the reflector to irradiate it outside the vehicle headlamp. The light guide has a housing portion near the optical center that houses at least a portion of the light source so that it faces at least a portion of the reflector.

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

[0004] From the viewpoint of the overall design of the lamp, it is preferable that the exit surface of the light guide be thin in the vertical direction. However, the thinner the exit surface, the more difficult it is for the light emitted from the light source to enter the exit surface, resulting in a decrease in luminous flux utilization rate and maximum luminous intensity. Increasing the number of light sources is an option, but this would increase the power consumption per lamp.

[0005] An object of the present disclosure is to provide a vehicle headlamp with improved luminous flux utilization rate and maximum luminous intensity.

[0006] A vehicle headlamp according to one aspect of the present disclosure is a vehicle headlamp that forms a low-beam light distribution pattern, the vehicle headlamp comprising: a light source; a primary optical element that converts light emitted from the light source into parallel light; and a light guide into which the parallel light emitted from the primary optical element is incident, the light guide having an exit surface that is provided on the front surface of the light guide and that emits light to form the low-beam light distribution pattern; and a reflecting portion that is provided on the light guide as a total reflection surface and that reflects light from the primary optical element directly or indirectly toward the exit surface into the light guide, the reflecting portion being composed of a plurality of mutually different reflecting surfaces.

[0007] According to the present disclosure, since the reflector is composed of a plurality of different reflecting surfaces, light incident on the reflector is reflected in different directions by the plurality of reflecting surfaces. Therefore, compared to a case where the reflector is composed of a single reflecting surface, light from the light source can be more efficiently reflected to the light output surface. As a result, the luminous flux utilization rate and maximum luminous intensity of the lamp can be improved.

[0008] According to the present disclosure, a vehicle headlamp is provided that has improved luminous flux utilization rate and maximum luminous intensity.

[0009] FIG. 1 is a cross-sectional view illustrating an optical unit of a vehicle headlight according to this embodiment. FIG. 2 is a schematic cross-sectional view illustrating a state in which light emitted from a light source is emitted from an exit surface of a light guide of the optical unit. FIG. 3 is a cross-sectional view illustrating a configuration of an optical unit of a vehicle headlight according to Modification 1. FIG. 4 is a cross-sectional view illustrating a configuration of an optical unit of a vehicle headlight according to Modification 2. FIG. 5 is a cross-sectional view illustrating a configuration of an optical unit of a vehicle headlight according to Modification 3. FIG. 6 is a cross-sectional view illustrating a configuration of an optical unit of a vehicle headlight according to Modification 4. FIG. 7 is a cross-sectional view illustrating a configuration of an optical unit of a vehicle headlight according to Modification 5. FIG. 8 is a cross-sectional view illustrating a configuration of an optical unit of a vehicle headlight according to Modification 6. FIG. 9 is a cross-sectional view illustrating a configuration of an optical unit of a vehicle headlight according to Modification 7.

[0010] 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.

[0011] 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 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.

[0012] An optical unit 1 for a vehicle headlamp according to this embodiment will be described with reference to FIG.

[0013] Fig. 1 is a cross-sectional view illustrating an optical unit 1 of a vehicle headlamp according to this embodiment. As shown in Fig. 1, the optical unit 1 includes a light source 10, a primary optical member 20, and a light guide 30. Each of the components will be described below.

[0014] The light source 10 emits light that forms a low-beam light distribution pattern LP. The light source 10 is, for example, an LED (Light Emitting Diode) element or an LD (Laser Diode) element.

[0015] The primary optical member 20 is configured to convert the light emitted from the light source 10 into parallel light. Specifically, the primary optical member 20 has a reflecting surface 21 at a position facing the light source 10. The reflecting surface 21 converts the light emitted from the light source 10 into parallel light and reflects it toward the light guide 30. The primary optical member 20 is, for example, a parabolic reflector.

[0016] The light guide 30 is formed of a transparent material that transmits light. The light guide 30 is configured to guide light from the light source 10 that is incident via the primary optical member 20 toward the front of the vehicle. The light guide 30 has an incident surface 31, an exit surface 32, a reflecting portion 33, and a cutoff line forming portion 34Z. Parallel light incident on the incident surface 31 is guided into the light guide 30, reflected by the reflecting portion 33, and guided to the exit surface 32.

[0017] 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.

[0018] The exit surface 32 is provided on the front surface of the light guide 30. In this embodiment, the exit surface 32 is a single lens surface. The exit surface 32 emits the incident parallel light forward to form a low-beam light distribution pattern LP.

[0019] The reflecting portion 33 is provided as a total reflection surface behind the exit surface 32. The reflecting portion 33 is configured to reflect the parallel light from the primary optical member 20 directly or indirectly onto the exit surface 32 toward the inside of the light guide 30. The way in which the light travels will be described in detail later.

[0020] The reflecting portion 33 has a first reflecting surface 331 and a second reflecting surface 332. The second reflecting surface 332 is a reflecting surface different from the first reflecting surface 331. In other words, the reflecting portion 33 has two reflecting surfaces that are different from each other, the first reflecting surface 331 and the second reflecting surface 332. The first reflecting surface 331 and the second reflecting surface 332 are examples of a plurality of reflecting surfaces.

[0021] The cutoff line forming portion 34Z is provided between the light exit surface 32 and the reflecting portion 33. The cutoff line forming portion 34Z is configured to form a cutoff line CL of the low beam distribution pattern LP. The cutoff line forming portion 34Z is configured to totally reflect a part of the light reflected by the reflecting portion 33, for example.

[0022] A recess 34 is formed in the bottom 30d of the light guide 30. The cutoff line forming portion 34Z is formed by this recess 34. More specifically, the cutoff line forming portion 34Z is a corner formed by the front surface 34F and the upper surface 34U of the recess 34. The recess 34 is provided so that a gap is generated between the second reflecting surface 332 and the light exit surface 32. The recess 34 is located between the reflecting portion 33 and the light exit surface 32 in the front-rear direction. The recess 34 has a shape in which a part of the bottom 30d of the light guide 30 is recessed upward in the up-down direction of the light guide 30.

[0023] The recess 34 has a rear surface 34B extending in a direction intersecting the front-rear direction, a front surface 34F located forward of the rear surface 34B and extending in a direction intersecting the front-rear direction, and an upper surface 34U connecting the upper portions of the rear surface 34B and the front surface 34F. The upper surface 34U is configured to totally reflect at least a portion of the light incident from the reflecting portion 33. The cutoff line forming portion 34Z is a corner formed by the front surface 34F and the upper surface 34U. Although not shown, the cutoff line forming portion 34Z extends in a staggered manner in the left-right direction when viewed from the front. The shape of the cutoff line forming portion 34Z viewed from the front is similar to the cutoff line CL of the low-beam light distribution pattern LP. The upper surface 34U is an example of another total reflection surface. The rear surface 34B is an example of a third surface.

[0024] Next, the propagation of light will be described with reference to FIG. 2 . FIG. 2 is a schematic cross-sectional view illustrating the manner in which light emitted from the light source 10 is emitted from the emission surface 32 of the light guide 30. For ease of explanation, a portion of the light emitted from the light source 10 and reflected by the first reflecting surface 331 will be referred to as light L1. Meanwhile, another portion of the light emitted from the light source 10 and reflected by the second reflecting surface 332 will be referred to as light L2. The propagation of each of light L1 and light L2 will be described below. Here, L1 refers to light of relatively high intensity emitted from the light source 10 at an emission angle smaller than a predetermined angle. Furthermore, L2 refers to light of relatively low intensity emitted from the light source 10 at an emission angle larger than the predetermined angle.

[0025] First, the travel of light L1 will be described. As shown in Fig. 2, a portion of light L1 emitted from light source 10 is reflected by reflecting surface 21 of primary optical member 20 and becomes parallel light. The parallel light L1 is incident on incident surface 31 of light guide 30, is guided into light guide 30, and reaches first reflecting surface 331 at the rear of light guide 30.

[0026] The light L1 is reflected by the first reflecting surface 331 directly to the exit surface 32 toward the front of the light guide 30. The light L1 reflected by the first reflecting surface 331 passes near the cutoff line forming portion 34Z and reaches the exit surface 32. As the light L1 passes near the cutoff line forming portion 34Z, a portion of the light L1 is totally reflected by the upper surface 34U behind the cutoff line forming portion 34Z and does not reach the exit surface 32. The remaining portion of the light L1 that does not strike the upper surface 34U reaches the exit surface 32. In other words, the light L1 that passes above the cutoff line forming portion 34Z reaches the exit surface 32, so the exit surface 32 forms a low-beam distribution pattern LP in which the upper portion is shielded from light and the lower portion is illuminated with light. The cutoff line forming portion 34Z, which has a boundary between a light-transmitting region and a light-blocking region, has a stepped shape when viewed from the front, so a step-shaped cutoff line is formed between the bright and dark regions of the low-beam distribution pattern LP.

[0027] Next, the travel of light L2 will be described. As shown in Figure 2, another portion of light L2 emitted from light source 10 is also reflected by reflecting surface 21 of primary optical member 20 and becomes parallel light. Light L2, which has become parallel light, is incident on incident surface 31 of light guide 30, is guided into light guide 30, and reaches second reflecting surface 332 at the rear of light guide 30.

[0028] The light L2 is indirectly reflected by the second reflecting surface 332 toward the front inside the light guide 30 and toward the output surface 32. More specifically, a portion of the light L2 is reflected by the second reflecting surface 332 and then totally reflected by the upper surface 34U behind the cutoff line forming portion 34Z toward the output surface 32. In this way, the light L2 is not directly reflected from the second reflecting surface 332 toward the output surface 32, but is indirectly reflected from the second reflecting surface 332 to the output surface 32 via the upper surface 34U, which is a total reflection surface.

[0029] In this way, the light guide 30 irradiates the light L2 reflected by the second reflecting surface 332 in front of the vehicle as a low-beam light distribution pattern LP. The light guide 30 may irradiate the light L2 reflected by the second reflecting surface 332 in front of the vehicle so that the light L2 overlaps at least a part of the low-beam light distribution pattern LP formed by the light L1 reflected by the first reflecting surface 331.

[0030] In this way, the light guide 30 is configured so that the reflecting portion 33 onto which light emitted from the common light source 10 is incident has different first and second reflecting surfaces 331 and 332, and the light reflected by each reflecting surface forms different light distribution patterns. In this embodiment, the first reflecting surface 331 reflects light L1 that forms the low-beam light distribution pattern LP, and the second reflecting surface 332 reflects light L2 that forms a light distribution pattern that overlaps with part of the low-beam light distribution pattern LP. However, by devising the first reflecting surface 331, the second reflecting surface 332, the exit surface 32, etc., a variety of different light distribution patterns can be formed.

[0031] Furthermore, light L1 is light emitted from light source 10 at an emission angle smaller than a predetermined angle, and conventionally, light emitted at such an emission angle has been effectively used to form a light distribution pattern. However, light L2 emitted from light source 10 at an emission angle larger than the predetermined angle has a relatively low intensity, and is emitted at an angle larger than light L1. Therefore, attempting to utilize such light would tend to require larger reflectors and lenses, making it difficult to use. However, in this embodiment, a light distribution pattern is also formed by light L2, and therefore the light emitted from light source 10 is effectively utilized.

[0032] As described above, the vehicle headlamp of this embodiment is a vehicle headlamp that forms a low-beam light distribution pattern LP. The optical unit 1 of the vehicle headlamp includes a light source 10, a primary optical member 20 that converts light emitted from the light source 10 into parallel light, and a light guide 30 onto which the parallel light emitted from the primary optical member 20 is incident. The light guide 30 has an exit surface 32 that is provided on the front surface of the light guide 30 and that emits light to form the low-beam light distribution pattern LP, and a reflecting portion 33 that is provided on the light guide 30 as a total reflection surface and that directly or indirectly reflects light from the primary optical member 20 toward the light guide 30. The reflecting portion 33 is composed of multiple reflecting surfaces, including a first reflecting surface 331 and a second reflecting surface 332. The light incident on the reflecting portion 33 is reflected in different directions by each of the reflecting surfaces. In other words, the first reflecting surface 331 and the second reflecting surface 332 can each reflect the light from the light source 10 in different directions. Therefore, compared to when the reflecting portion is composed of a single reflecting surface, the light from the light source 10 can be more efficiently reflected to the emission surface 32. As a result, the luminous flux utilization rate and maximum luminous intensity of the optical unit 1 for a vehicle headlamp can be improved.

[0033] The light guide 30 has a cutoff line forming portion 34Z. The cutoff line forming portion 34Z partially blocks light from the light source 10, thereby forming a cutoff line CL of the low-beam light distribution pattern LP and reducing glare to oncoming vehicles and vehicles ahead.

[0034] The cutoff line forming portion 34Z is formed between the reflecting portion 33 and the emission surface 32 by a recess 34 formed in the bottom portion 30d of the light guide 30. With such a simple configuration, the cutoff line forming portion 34Z can be provided.

[0035] An upper surface 34U, which is a total reflection surface, is provided behind the cutoff line forming portion 34Z. The upper surface 34U can guide the light L2 to the emission surface 32, thereby improving the luminous flux utilization rate.

[0036] The primary optical member 20 is a parabolic reflector. Compared to other optical members, a parabolic reflector has a structural advantage in that it is easy to extend the reflective surface 21 widely. This makes it easy to ensure a wide reflective surface 21, and allows more light from the light source 10 to be reflected toward the light guide 30.

[0037] The light guide 30 irradiates the light L1 reflected by the first reflecting surface 331 and the light L2 reflected by the second reflecting surface 332 toward the front of the vehicle. Therefore, it is easier to increase the luminous flux utilization rate of the optical unit 1 of the vehicle headlamp compared to when the reflecting portion 33 has only one reflecting surface.

[0038] The light guide 30 emits the light L2 reflected by the second reflecting surface 332 toward the front of the vehicle so that the light L2 overlaps with the illumination area formed by the light L1 reflected by the first reflecting surface 331. Since the luminous intensity of the area where the light L1 and the light L2 overlap can be increased, it is easier to increase the maximum luminous intensity of the optical unit 1 of the vehicle headlamp.

[0039] The light guide 30 may irradiate the light L1 reflected by the first reflecting surface 331 as a low-beam light distribution pattern LP toward the front of the vehicle, and may irradiate a portion of the light L3 reflected by the second reflecting surface 332 as an OHS (Over Head Sign) light distribution pattern toward the front of the vehicle ( FIG. 2 ). For convenience of explanation, the light emitted from the light source 10 that forms the OHS light distribution pattern is referred to as light L3. The OHS light distribution pattern is an example of another light distribution pattern different from the low-beam light distribution pattern LP.

[0040] 2, light L3 emitted from light source 10 is reflected by reflecting surface 21 of primary optical member 20 to become parallel light. The parallel light L3 is incident on incident surface 31 of light guide 30, guided into light guide 30, reflected by second reflecting surface 332, and reaches rear surface 34B of recess 34. Light L3 passes from rear surface 34B through the cavity formed by recess 34, and passes through front surface 34F to be indirectly emitted to exit surface 32.

[0041] Here, the emission angle of light L3 is larger than the emission angle of light L1 and the emission angle of light L2. Light L3 with such a large emission angle has rarely been utilized in the past. However, in this embodiment, light L3 passes below the cutoff line forming portion 34Z and is emitted as an OHS light distribution pattern from the lower part of the emission surface 32. Therefore, light emitted from the light source 10 at a large emission angle is also irradiated forward of the lamp, thereby increasing the luminous flux utilization rate.

[0042] The recess 34 is also provided with a rear surface 34B that indirectly directs the light L3 incident on the second reflecting surface 332 toward the light exit surface 32. The rear surface 34B allows the light L3 to be guided to the light exit surface 32 more efficiently.

[0043] The first reflecting surface 331 and the second reflecting surface 332 have different focal points. In Fig. 2, the first focal point F1 of the first reflecting surface 331 is located slightly forward of the cutoff line forming portion 34Z. Therefore, part of the light L1 reflected by the first reflecting surface 331 is totally reflected by the upper surface 34U of the cutoff line forming portion 34Z, thereby forming a low-beam light distribution pattern LP.

[0044] On the other hand, the second focal point F2 of the second reflecting surface 332 is located on the upper surface 34U, slightly behind the cutoff line forming portion 34Z. Therefore, the light L2 reflected by the second reflecting surface 332 is reflected by the upper surface 34U and enters the upper part of the emission surface 32, and is irradiated in front of the lamp so as to overlap with the low-beam light distribution pattern LP.

[0045] The first reflecting surface 331 and the second reflecting surface 332 may be adjacent to each other (FIG. 1). Since a plurality of reflecting surfaces are adjacent to each other, it is easy to design the shape of the reflecting portion 33 and the optical path simply.

[0046] The incident surface 31 of the light guide 30 may have a first incident surface 311 and a second incident surface 312 ( FIG. 1 ). The first incident surface 311 is a surface onto which a portion of the parallel light from the primary optical member 20 is incident. For convenience of explanation, the first incident surface 311 is assumed to be a surface that receives the light L1 reflected by the first reflecting surface 331. The first incident surface 311 is a flat surface. The light L1, which has been converted into parallel light by the reflecting surface 21 of the primary optical member 20, is incident on the first incident surface 311, reflected by the first reflecting surface 331, and emitted forward from the exit surface 32. In this way, the first incident surface 311 can efficiently guide the light L1 to the first reflecting surface 331.

[0047] The second incident surface 312 is a surface onto which another portion of the collimated light from the primary optical member 20 is incident. For convenience of explanation, the second incident surface 312 is assumed to be a surface that receives the light L2 reflected by the second reflecting surface 332. The second incident surface 312 is a flat surface. The light L2 that has been converted into collimated light by the reflecting surface 21 of the primary optical member 20 is incident on the second incident surface 312, reflected by the second reflecting surface 332 and the upper surface 34U, and emitted forward from the exit surface 32. In this way, the second incident surface 312 can efficiently guide the light L2 to the second reflecting surface 332.

[0048] The first entrance surface 311 and the second entrance surface 312 may be adjacent to each other (FIG. 1). Since a plurality of entrance surfaces are adjacent to each other, it is easy to design the shape of the entrance surface 31 simply.

[0049] (Modification 1) An optical unit 1A for a vehicle headlamp according to Modification 1 will be described with reference to Fig. 3. Fig. 3 is a cross-sectional view illustrating the configuration of the optical unit 1A for a vehicle headlamp according to Modification 1. In the configuration shown in Fig. 3, the same components as those shown in Fig. 1 are denoted by the same reference numerals, and descriptions thereof will be omitted.

[0050] In the light guide 30 shown in Fig. 1, the first incident surface 311 is a flat surface, whereas in the light guide 30A shown in Fig. 3, the first incident surface 311A ​​is a curved surface.

[0051] More specifically, the light guide 30A of the optical unit 1A for a vehicle headlamp has a notch 31A in a portion that receives the parallel light from the primary optical member 20. The notch 31A is provided to face the reflecting surface 21 of the primary optical member 20. The notch 31A has a shape in which a part of the upper portion 30u of the light guide 30A is recessed downward in the up-down direction.

[0052] The cutout portion 31A is formed with a first incident surface 311A ​​and a second incident surface 312A. The second incident surface 312A is a flat surface located behind the cutout portion 31A and extending in the front-to-rear direction. The first incident surface 311A ​​is located in front of the second incident surface 312A and is a surface that connects the second incident surface 312A to the upper portion 30u of the light guide 30A. The first incident surface 311A ​​is a curved surface. The first incident surface 311A ​​is configured to refract the light L1 reflected by the first reflecting surface 331. In other words, the first incident surface 311A ​​is a refractive surface that refracts the light L1.

[0053] Light L1, which has been converted into parallel light by reflecting surface 21 of primary optical member 20, is reflected by first reflecting surface 331, enters first incident surface 311A, and is refracted by first incident surface 311A. The refracted light L1 is guided directly to exit surface 32. In this way, because first incident surface 311A ​​is a curved surface, light L1 can be more efficiently guided to exit surface 32.

[0054] (Modification 2) An optical unit 1B for a vehicle headlamp according to Modification 2 will be described with reference to Fig. 4. Fig. 4 is a cross-sectional view illustrating the configuration of the optical unit 1B for a vehicle headlamp according to Modification 2. In the configuration shown in Fig. 4, the same components as those shown in Fig. 1 are denoted by the same reference numerals, and descriptions thereof will be omitted.

[0055] In the optical unit 1 shown in Fig. 1, the primary optical member 20 is a parabolic reflector different from the light guide 30. On the other hand, in the optical unit 1B shown in Fig. 4, a first TIR section 22 and a second TIR section 23 formed integrally with the light guide 30B are provided as the primary optical member 20B. The first TIR section 22 and the second TIR section 23 each form a total internal reflection lens, and emit light from the light source 10 as parallel light.

[0056] More specifically, optical unit 1B includes light source 10 and light guide 30B. Light guide 30B has first TIR section 22 and second TIR section 23. For ease of explanation, a portion of the light emitted from light source 10 and guided by first TIR section 22 will be referred to as light L1. As will be described later, light L1 is also light reflected by first reflecting surface 331. Another portion of the light emitted from light source 10 and guided by second TIR section 23 will be referred to as light L2. Light L2 is also light reflected by second reflecting surface 332.

[0057] The first TIR section 22 and the second TIR section 23 are each provided to face the light source 10. The first TIR section 22 and the second TIR section 23 are adjacent to each other in the front-to-rear direction. The first TIR section 22 is formed integrally with the light guide 30B. There is no boundary surface between the first TIR section 22 and the first reflecting surface 331, and no first incident surface 311 is provided. Similarly, the second TIR section 23 is formed integrally with the light guide 30B. There is no boundary surface between the second TIR section 23 and the second reflecting surface 332, and no second incident surface 312 is provided. In this way, the light guide 30B has the first TIR section 22 and the second TIR section 23 integrally.

[0058] The light guide 30B further includes a notch 31B between the first reflecting surface 331 and the cutoff line forming portion 34Z in the front-rear direction. The notch 31B has a shape in which a portion of the upper portion 30u of the light guide 30B is recessed downward in the up-down direction. A refracting surface 311B is formed in the notch 31B. The refracting surface 311B is configured to refract the light L1 reflected by the first reflecting surface 331 toward the exit surface 32.

[0059] A portion of light L1 emitted from light source 10 enters first TIR section 22 and becomes parallel light. Light L1, which has been parallelized by first TIR section 22, is guided to first reflecting surface 331 and irradiated to the outside of light guide 30B through cutout section 31B. Light L1 is then refracted by refraction surface 311B and guided again from refraction surface 311B into light guide 30B and toward exit surface 32. Meanwhile, another portion of light L2 emitted from light source 10 enters second TIR section 23 and becomes parallel light. Light L2, which has been parallelized by second TIR section 23, is guided to second reflecting surface 332 and indirectly reflected toward exit surface 32 via cutoff line forming section 34Z.

[0060] In this way, the optical unit 1B for the vehicle headlamp can individually control the light L1 and the light L2 using two TIR sections, the first TIR section 22 and the second TIR section 23. Specifically, the first TIR section 22 can more efficiently guide the light L1 toward the first reflecting surface 331, and the second TIR section 23 can more efficiently guide the light L2 toward the second reflecting surface 332. Therefore, compared to when the primary optical member is composed of a single member, the light from the light source 10 can be more efficiently guided to each of the first reflecting surface 331 and the second reflecting surface 332, thereby further improving the luminous flux utilization rate and maximum luminous intensity of the optical unit 1B. Furthermore, the first TIR section 22 and the second TIR section 23 are integrally formed with the light guide body 30B, thereby reducing the number of parts.

[0061] Furthermore, optical unit 1B has two TIR sections, namely, first TIR section 22 and second TIR section 23, in addition to reflecting section 33 having two reflecting surfaces, namely, first reflecting surface 331 and second reflecting surface 332. It can be said that optical unit 1B is configured to split the light emitted from light source 10 by these two TIR sections.

[0062] (Modification 3) An optical unit 1C for a vehicle headlamp according to Modification 3 will be described with reference to Fig. 5. Fig. 5 is a cross-sectional view illustrating the configuration of the optical unit 1C for a vehicle headlamp according to Modification 3. In the configuration shown in Fig. 5, the same components as those shown in Fig. 1 are denoted by the same reference numerals, and descriptions thereof will be omitted.

[0063] In the optical unit 1 shown in Fig. 1, the primary optical member 20 is a parabolic reflector, whereas the optical unit 1B shown in Fig. 5 is provided with a bullet-shaped lens 20C as the primary optical member.

[0064] More specifically, the optical unit 1C for a vehicle headlamp includes a light source 10, a bullet-shaped lens 20C, and a light guide 30C. The bullet-shaped lens 20C is a lens having a downwardly convex parabolic shape. The bullet-shaped lens 20C is configured to receive light from the light source 10, collimate the received light, and emit it toward the incident surface 31 of the light guide 30C.

[0065] A portion of light L1 emitted from light source 10 enters bullet-shaped lens 20C and becomes parallel light. The parallel light L1 is guided from first incident surface 311 to first reflecting surface 331 and reflected to exit surface 32. A downwardly recessed notch 31C may be provided in a portion of upper portion 30u of light guide 30C. A refractive surface 311C formed in notch 31C may refract light L1 reflected by first reflecting surface 331 toward exit surface 32. Another portion of light L2 emitted from light source 10 enters bullet-shaped lens 20C and becomes parallel light. The parallel light L2 is guided to second reflecting surface 332 and indirectly reflected to exit surface 32 via upper surface 34U of cutoff line forming portion 34Z.

[0066] The bullet-shaped lens 20C can emit highly parallel light beams. Since the bullet-shaped lens 20C can emit the light beams L1 and L2 with high parallelism to the light guide 30, the maximum luminous intensity of the optical unit 1C can be further increased.

[0067] (Modification 4) An optical unit 1D for a vehicle headlamp according to Modification 4 will be described with reference to Fig. 6. Fig. 6 is a cross-sectional view illustrating the configuration of the optical unit 1D for a vehicle headlamp according to Modification 4. In the configuration shown in Fig. 6, the same components as those shown in Fig. 1 are denoted by the same reference numerals, and descriptions thereof will be omitted.

[0068] The optical unit 1 shown in Fig. 1 has one lens element portion, which is a light guide 30. On the other hand, the light guide 30D of the optical unit 1D shown in Fig. 6 has a first lens element portion 30D1 and a second lens element portion 30D2 provided integrally below the first lens element portion 30D1.

[0069] The first lens element portion 30D1 has a first entrance surface 311, a first reflecting surface 331, a first cutoff line forming portion 35Z, and a first exit surface 321. The configurations of the first entrance surface 311, the first reflecting surface 331, and the first exit surface 321 are the same as those described above, and therefore description thereof will be omitted.

[0070] A first recess 35 is formed in the bottom 30d1 of the first lens element 30D1. The first recess 35 is formed by an air layer. A first cutoff line forming portion 35Z is formed by this first recess 35. More specifically, the first cutoff line forming portion 35Z is a corner formed by the front surface 35F and the top surface 35U of the first recess 35. The first recess 35 is provided so that a gap is formed between the first reflecting surface 331 and the first exit surface 321. The first recess 35 is located between the reflecting portion 33 and the first exit surface 321 in the front-rear direction. The first recess 35 has a shape in which a portion of the bottom 30d1 of the first lens element 30D1 is recessed upward in the up-down direction of the light guide 30D.

[0071] The first recess 35 has a front surface 35F extending in a direction intersecting the front-rear direction, an upper surface 35U provided rearward of the front surface 35F and extending in the front-rear direction, and an inclined surface 35D connecting a lower portion of the front surface 35F to a lower portion of the upper surface 35U. The upper surface 35U is configured to totally reflect at least a portion of the light incident from the first reflecting surface 331. The first cutoff line forming portion 35Z is a corner formed by the front surface 35F and the upper surface 35U.

[0072] The first lens element portion 30D1 has the first cutoff line forming portion 35Z, and therefore can form a low-beam light distribution pattern LP having a cutoff line CL.

[0073] Similar to the first lens element portion 30D1, the second lens element portion 30D2 has a second entrance surface 312, a second reflecting surface 332, a second cutoff line forming portion 36Z, and a second exit surface 322. The configurations of the second entrance surface 312, the second reflecting surface 332, and the second exit surface 322 are the same as those described above, and therefore description thereof will be omitted.

[0074] A second recess 36 is formed in the bottom 30d2 of the second lens element 30D2. The second cutoff line forming portion 36Z is formed by this second recess 36. More specifically, the second cutoff line forming portion 36Z is a corner formed by the front surface 36F and the upper surface 36U of the second recess 36. The second recess 36 is provided so that a gap is formed between the second reflecting surface 332 and the second emission surface 322. The second recess 36 is located between the reflecting portion 33 and the second emission surface 322 in the front-rear direction. The second recess 36 has a shape in which a portion of the bottom 30d2 of the second lens element 30D2 is recessed upward in the up-down direction of the light guide 30D.

[0075] The second recess 36 has a front surface 36F extending in a direction intersecting the front-rear direction and an upper surface 36U located rearward of the front surface 36F and extending in the front-rear direction. The upper surface 36U is configured to totally reflect at least a portion of the light incident from the second reflecting surface 332. The second cutoff line forming portion 36Z is a corner formed by the front surface 36F and the upper surface 36U.

[0076] Unlike this modified example, if the second lens element portion 30D2 is simply stacked below the first lens element portion 30D1, no gap will be created between the first lens element portion 30D1 and the second lens element portion 30D2, and the first cutoff line forming portion 35Z cannot be provided.

[0077] 6, however, a first recess 35 is provided below first lens element 30D1 to form an air layer. This makes it possible to provide first cutoff line forming portion 35Z below first lens element 30D1, and first lens element 30D1 can form a low-beam light distribution pattern LP having a cutoff line CL, similar to second lens element 30D2. By superimposing the light distribution pattern formed by second lens element 30D2 on the low-beam light distribution pattern LP formed by first lens element 30D1, a low-beam light distribution pattern LP with higher luminous intensity can be formed.

[0078] The light guide 30D may be provided with a total reflection surface on each of the upper surface 35U of the first cutoff line forming portion 35Z and the upper surface 36U of the second cutoff line forming portion 36Z. The upper surface 35U is configured to totally reflect a portion of the light L1' reflected by the first reflecting surface 331 toward the first exit surface 321. Similarly, the upper surface 36U is configured to totally reflect a portion of the light L2' reflected by the second reflecting surface 332 toward the second exit surface 322. Such total reflection surfaces can further increase the luminous flux utilization rate of the optical unit 1D of the vehicle headlamp.

[0079] (Modification 5) An optical unit 1E for a vehicle headlamp according to Modification 5 will be described with reference to Fig. 7. Fig. 7 is a cross-sectional view illustrating the configuration of the optical unit 1E for a vehicle headlamp according to Modification 5. In the configuration shown in Fig. 7, the same components as those shown in Fig. 1 are denoted by the same reference numerals, and descriptions thereof will be omitted.

[0080] In the optical unit 1 for a vehicle headlight shown in Fig. 1, the light source 10 is provided above the light guide 30. On the other hand, in the optical unit 1E for a vehicle headlight shown in Fig. 7, the light source 10 is provided below the light guide 30E. Furthermore, in the optical unit 1 for a vehicle headlight shown in Fig. 1, the first incident surface 311 and the second incident surface 312 are adjacent to each other. On the other hand, in the optical unit 1E for a vehicle headlight shown in Fig. 7, the first incident surface 311E and the second incident surface 312E are spaced apart from each other.

[0081] More specifically, the optical unit 1E for a vehicle headlamp includes a light source 10, a primary optical member 20E, and a light guide 30E. The light source 10 is provided below the light guide 30E.

[0082] The primary optical member 20E has a reflecting surface 21E that reflects light emitted from the light source 10. The reflecting surface 21E has a parabolic direct reflecting surface 211 onto which the light emitted from the light source 10 is directly incident, and an indirect reflecting surface 212 onto which a portion of the light reflected by the direct reflecting surface 211 is incident. The indirect reflecting surface 212 is disposed opposite the direct reflecting surface 211. The direct reflecting surface 211 reflects the light emitted from the light source 10 as parallel light directly or indirectly toward the light guide 30E. The indirect reflecting surface 212 is a flat surface. The indirect reflecting surface 212 reflects the parallel light incident from the direct reflecting surface 211 toward the light guide 30E as parallel light.

[0083] The light guide 30E is an integrated lens element extending in the front-to-rear direction. A second incident surface 312E, onto which light reflected by the direct reflection surface 211 is incident, is provided on the lower surface of the rear portion of the light guide 30E. In the light guide 30E, the rear portion of the direct reflection surface 211 is provided in a convex shape rearward of the second incident surface 312E of the light guide 30E. Therefore, a portion of the light reflected by the direct reflection surface 211 is incident on the indirect reflection surface 212 without being incident on the second reflection surface 332F of the light guide 30E.

[0084] The rear surface of the light guide 30E is provided with a second reflecting surface 332E onto which the parallel light emitted from the direct reflecting surface 211 is incident, and a first incident surface 311E onto which the parallel light emitted from the indirect reflecting surface 212 is incident. The first incident surface 311E has a refractive surface that refracts light. The light guide 30E further has a cutoff line forming portion 34Z and an output surface 32. The cutoff line forming portion 34Z is a corner formed by the front surface 34F and the top surface 34U of the recess 34. A total reflection surface is formed on the top surface 34U.

[0085] Light incident on the first incident surface 311E from the indirect reflecting surface 212 is refracted by the refractive surface of the first incident surface 311E toward the exit surface 32. A portion of this light is blocked by the front surface 34F and the top surface 34U of the cutoff line forming portion 34Z as it travels from the first incident surface 311E to the exit surface 32. Therefore, the exit surface 32 irradiates this light forward as a low-beam light distribution pattern LP having a cutoff line CL.

[0086] The second reflecting surface 332E totally reflects the light incident from the direct reflecting surface 211 toward the upper surface 34U of the cutoff line forming portion 34Z. The upper surface 34U, which is a totally reflecting surface, causes this light to be incident on the upper part of the emitting surface 32. The emitting surface 32 emits this light so as to be superimposed on the lower part of the low-beam distribution pattern LP.

[0087] (Modification 6) An optical unit 1F for a vehicle headlamp according to Modification 6 will be described with reference to Fig. 8. Fig. 8 is a cross-sectional view illustrating the configuration of an optical unit 1F for a vehicle headlamp according to Modification 6. In the configuration shown in Fig. 8, the same components as those shown in Fig. 1 are denoted by the same reference numerals, and descriptions thereof will be omitted.

[0088] In the optical unit 1 for a vehicle headlamp shown in Fig. 1, the first reflecting surface 331 and the second reflecting surface 332 are adjacent to each other. On the other hand, in the optical unit 1F for a vehicle headlamp shown in Fig. 8, the first reflecting surface 331F and the second reflecting surface 332F are spaced apart from each other.

[0089] More specifically, the optical unit 1F for a vehicle headlamp includes a light source 10 and a light guide 30F. The light guide 30F has a first TIR portion 22F and a second TIR portion 23F. The light guide 30F further has a notch portion 33F in which a portion of an upper portion 30u of the light guide 30F is recessed downward. The notch portion 33F is provided to face the second TIR portion 23F. The notch portion 33F is provided with a refractive surface 311F and a second reflective surface 332F.

[0090] The first reflecting surface 331F is provided behind the cutout portion 33F and facing the first TIR portion 22F. The first reflecting surface 331F is configured to indirectly reflect the light L1, which has been collimated by the first TIR portion 22F, from the refraction surface 311F to the emission surface 32, after passing through the cavity of the cutout portion 33F.

[0091] The second reflecting surface 332F is provided to face the second TIR section 23F. The second reflecting surface 332F is configured to indirectly reflect the light L2, which has been converted into parallel light by the second TIR section 23F, to the exit surface 32 via the upper surface 34U of the cutoff line forming section 34Z.

[0092] A portion of light L1 emitted from light source 10 enters first TIR section 22F and becomes parallel light. Light L1 that has been parallelized by first TIR section 22F is guided to first reflecting surface 331F and reflected to notch 33F. Light L1 is emitted from notch 33F to the outside of light guide 30F. Light L1 then passes through notch 33F, enters light guide 30F from refracting surface 311F of notch 33F, and travels toward exit surface 32.

[0093] Meanwhile, another portion of light L2 emitted from the light source 10 is incident on the second TIR section 23 and becomes parallel light. The light L2 that has been parallelized by the second TIR section 23 is guided to the second reflecting surface 332 and indirectly reflected to the exit surface 32 via the upper surface 34U of the cutoff line forming section 34Z.

[0094] In this way, the first reflecting surface 331F and the second reflecting surface 332F are spaced apart from each other. Therefore, the first reflecting surface 331F and the second reflecting surface 332F can easily guide light to the light exit surface 32 individually.

[0095] (Variation 7) An optical unit 1G for a vehicle headlamp according to Variation 7 will be described with reference to Fig. 9. Fig. 9 is a cross-sectional view illustrating the configuration of an optical unit 1G for a vehicle headlamp according to Variation 7. In the configuration shown in Fig. 9, the same components as those shown in Fig. 1 are denoted by the same reference numerals, and descriptions thereof will be omitted.

[0096] The optical unit 1G of the vehicle headlamp is configured to irradiate a low beam light distribution pattern LP with light L1, and also to irradiate an OHS light distribution pattern with light L3.

[0097] More specifically, the optical unit 1G for a vehicle headlamp includes a light source 10, a primary optical member 20G, and a light guide 30G. The primary optical member 20G has a parabolic reflecting surface 21G onto which light L1 is incident, as well as an OHS reflecting surface 24 onto which light L3, having a larger emission angle than light L1, is incident. The OHS reflecting surface 24 is disposed to face the light source 10 and is disposed between the reflecting surface 21G and the incident surface 31G of the light guide 30G in the vertical direction. The OHS reflecting surface 24 is configured to reflect light L3 toward a cutoff line forming portion 34Z. In this modification, the lower portion of the light guide 30G is shaped so as not to block light L3 traveling from the OHS reflecting surface 24 toward the cutoff line forming portion 34Z. Specifically, the lower surface of the light guide 30G is an inclined surface that slopes upward from the front to the rear.

[0098] 9 , light L3 emitted from the light source 10 is reflected by the OHS reflecting surface 24 of the primary optical member 20G. The reflected light L3 passes through the exterior of the light guide 30G and is guided from the front surface 34F of the cutoff line forming portion 34Z to the interior of the light guide 30G. The light L3 then travels from the front surface 34F of the cutoff line forming portion 34Z toward the exit surface 32.

[0099] In this way, the optical unit 1G for a vehicle headlamp includes the OHS reflecting surface 24 between the reflecting surface 21G of the primary optical member 20G and the incident surface 31G of the light guide 30G. Because an OHS light distribution pattern is formed by the light L3 that attempts to pass between the reflecting surface 21G of the primary optical member 20G and the incident surface 31G of the light guide 30G, the optical unit 1G for a vehicle headlamp is more likely to increase the luminous flux utilization rate.

[0100] 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.

[0101] 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, the vehicle headlamp including: a light source; a primary optical member that collimates light emitted from the light source; and a light guide into which the collimated light emitted from the primary optical member is incident, the light guide having: an exit surface that is provided on a front surface of the light guide and that emits light to form the low-beam light distribution pattern; and a reflecting portion that is provided on the light guide as a total reflection surface and that reflects light from the primary optical member directly or indirectly toward the exit surface into the light guide, the reflecting portion being composed of a plurality of mutually different reflecting surfaces. Item 2: The vehicle headlamp according to item 1, wherein the plurality of reflecting surfaces have mutually different focal points. Item 3: The vehicle headlamp according to item 1 or 2, wherein the plurality of reflective surfaces include a first reflective surface and a second reflective surface different from the first reflective surface, and the first reflective surface and the second reflective surface are adjacent to each other. Item 4: The vehicle headlamp according to item 1 or 2, wherein the plurality of reflective surfaces include a first reflective surface and a second reflective surface different from the first reflective surface, and the first reflective surface and the second reflective surface are spaced apart from each other. Item 5: The vehicle headlamp according to any one of items 1 to 4, wherein the light guide has a first incident surface that receives a portion of the collimated light and a second incident surface that receives another portion of the collimated light. Item 6: The vehicle headlamp according to item 5, wherein the first incident surface and the second incident surface are adjacent to each other. Item 7: The vehicle headlamp according to item 5, wherein the first incident surface and the second incident surface are spaced apart from each other. Item 8: The vehicle headlamp according to Item 5, wherein the first incident surface is a curved surface and the second incident surface is a flat surface. Item 9: The vehicle headlamp according to any one of Items 1 to 8, wherein the light guide has a cutoff line forming portion that forms a cutoff line of the low beam distribution pattern. Item 10: The vehicle headlamp according to Item 9, wherein the cutoff line forming portion is formed by a recess that is formed in a bottom portion of the light guide and is between the reflecting portion and the exit surface.Item 11: The vehicle headlamp according to Item 9 or 10, wherein another total reflection surface is provided behind the cutoff line forming portion. Item 12: The vehicle headlamp according to any one of Items 1 to 11, wherein the plurality of reflection surfaces include a first reflection surface and a second reflection surface different from the first reflection surface, a recess is provided in the light guide so as to create a gap between the second reflection surface and the exit surface, and a third surface is provided in the recess to direct light incident from the second reflection surface directly or indirectly toward the exit surface. Item 13: The vehicle headlamp according to any one of Items 1 to 12, wherein the primary optical member is a parabolic reflector. Item 14: The vehicle headlamp according to any one of Items 1 to 13, wherein the plurality of reflection surfaces include a first reflection surface and a second reflection surface different from the first reflection surface, and the light guide irradiates light reflected by the first reflection surface and the second reflection surface toward a front of the vehicle as the low-beam light distribution pattern. Item 15: The vehicle headlamp according to any one of Items 1 to 14, wherein the plurality of reflective surfaces have a first reflective surface and a second reflective surface different from the first reflective surface, and the light guide irradiates light reflected by the second reflective surface toward the front of the vehicle so that the light overlaps with the low-beam light distribution pattern formed by the light reflected by the first reflective surface. Item 16: The vehicle headlamp according to any one of Items 1 to 13, wherein the plurality of reflective surfaces have a first reflective surface and a second reflective surface different from the first reflective surface, and the light guide irradiates light reflected by the first reflective surface toward the front of the vehicle as the low-beam light distribution pattern, and irradiates light reflected by the second reflective surface toward the front of the vehicle as another light distribution pattern different from the low-beam light distribution pattern.

[0102] This application claims priority based on Japanese Application No. 2023-221018 filed on December 27, 2023, and incorporates by reference all of the contents of the aforementioned Japanese application.

Claims

1. A vehicle headlamp that forms a low-beam light distribution pattern, the vehicle headlamp comprising: a light source; a primary optical member that makes the light emitted from the light source into parallel light; and a light guide body into which the parallel light emitted from the primary optical member is incident, the light guide body having: an emission surface provided on the front surface of the light guide body and emitting light so as to form the low-beam light distribution pattern; and a reflection portion provided as a total reflection surface in the light guide body and reflecting the light from the primary optical member directly or indirectly toward the emission surface in the light guide body, the reflection portion being configured by a plurality of mutually different reflection surfaces.

2. The vehicle headlamp according to claim 1, wherein the plurality of reflection surfaces have mutually different focal points.

3. The vehicle headlamp according to claim 1, wherein the plurality of reflection surfaces include a first reflection surface and a second reflection surface different from the first reflection surface, and the first reflection surface and the second reflection surface are adjacent to each other.

4. The vehicle headlamp according to claim 1, wherein the plurality of reflection surfaces include a first reflection surface and a second reflection surface different from the first reflection surface, and the first reflection surface and the second reflection surface are separated from each other.

5. The vehicle headlamp according to claim 1, wherein the light guide body has a first incident surface that receives a part of the parallel light and a second incident surface that receives another part of the parallel light.

6. The vehicle headlamp according to claim 5, wherein the first incident surface and the second incident surface are adjacent to each other.

7. The vehicle headlamp according to claim 5, wherein the first incident surface and the second incident surface are separated from each other.

8. The vehicle headlamp according to claim 5, wherein the first incident surface is a curved surface and the second incident surface is a flat surface.

9. The vehicle headlamp according to claim 1, wherein the light guide body has a cut-off line forming portion that forms a cut-off line of the low-beam light distribution pattern.

10. The vehicle headlamp according to claim 9, wherein the cut-off line forming portion is formed by a concave portion formed at the bottom of the light guide body between the reflection portion and the emission surface.

11. The vehicle headlamp according to claim 9, wherein another total reflection surface is provided behind the cut-off line forming portion.

12. The plurality of the reflecting surfaces include a first reflecting surface and a second reflecting surface different from the first reflecting surface. A recess is provided in the light guide so that a gap is formed between the second reflecting surface and the light emitting surface. A third surface is provided in the recess to direct the light incident from the second reflecting surface directly or indirectly toward the light emitting surface. The vehicle headlamp according to claim 1.

13. The primary optical member is a parabolic reflector. The vehicle headlamp according to claim 1.

14. The plurality of the reflecting surfaces include a first reflecting surface and a second reflecting surface different from the first reflecting surface. The light guide irradiates the light reflected by the first reflecting surface and the second reflecting surface in front of the vehicle as the low beam light distribution pattern. The vehicle headlamp according to claim 1.

15. The plurality of the reflecting surfaces include a first reflecting surface and a second reflecting surface different from the first reflecting surface. The light guide irradiates the light reflected by the second reflecting surface in front of the vehicle so as to overlap with the low beam light distribution pattern formed by the light reflected by the first reflecting surface. The vehicle headlamp according to claim 1.

16. The plurality of the reflecting surfaces include a first reflecting surface and a second reflecting surface different from the first reflecting surface. The light guide irradiates the light reflected by the first reflecting surface in front of the vehicle as the low beam light distribution pattern, and irradiates the light reflected by the second reflecting surface in front of the vehicle as another light distribution pattern different from the low beam light distribution pattern. The vehicle headlamp according to claim 1.

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