Vehicle headlight

Abstract

In this invention, a light guide body has a first emission surface provided on the front surface of the light guide body, a second emission surface provided on the front surface of the light guide body, a first reflection surface provided on the rear surface of the light guide body and reflecting light incident on the light guide body from an optical member to make the light incident on the first emission surface, and a second reflection surface provided on the rear surface of the light guide body and reflecting the light incident on the light guide body from the optical member to make the light incident on the second emission surface. The focal position of the first reflection surface is located on or near the optical axis of the first emission surface, and the focal position of the second reflection surface is deviated from the optical axis of the second emission surface.

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 lamp be short in the vertical direction and long in the horizontal direction, however, it has been difficult to form a desired light distribution pattern with such a lamp.

[0005] An object of the present disclosure is to provide a vehicle headlamp that can easily form a desired light distribution pattern.

[0006] a first reflective surface provided on a rear surface of the light guide, the first reflective surface reflecting the light incident on the light guide from the optical member to the first exit surface; and a second reflective surface provided on the rear surface of the light guide, the second reflective surface reflecting the light incident on the light guide from the optical member to the second exit surface, the focal position of the first reflective surface being located on or near the optical axis of the first reflective surface, and the focal position of the second reflective surface being shifted from the optical axis of the second reflective surface.

[0007] A vehicle headlamp according to one aspect of the present disclosure is a vehicle headlamp that forms a light distribution pattern, and includes a light guide having a first exit surface that emits light to form a first light distribution pattern including a first hot zone, and a second exit surface that emits light to form a second light distribution pattern including a second hot zone, wherein the light distribution pattern is formed by superimposing the first light distribution pattern and the second light distribution pattern, and the hot zone of the light distribution pattern is formed by superimposing the first hot zone and the second hot zone, and the second hot zone of the second light distribution pattern is offset from the first hot zone of the first light distribution pattern.

[0008] According to the present disclosure, it is possible to provide a vehicle headlamp that can easily form a desired light distribution pattern.

[0009] FIG. 1 is a plan view illustrating the configuration of an optical unit according to a first embodiment. FIG. 2 is a cross-sectional view illustrating the configuration of a cross-section taken along line IIA-IIA or line IIB-IIB in FIG. 1, as viewed from the direction of the arrows. FIG. 3 is a diagram illustrating a first light distribution pattern formed by light emitted from a first emission surface. FIG. 4 is a diagram illustrating a second light distribution pattern formed by light emitted from a second emission surface. FIG. 5 is a diagram illustrating a low-beam light distribution pattern formed by light emitted from an optical unit. FIG. 6 is a schematic diagram illustrating a low-beam light distribution pattern PL illuminated by light emitted from a vehicle headlamp mounted on a vehicle, as viewed from above. FIG. 7 is a plan view illustrating the configuration of an optical unit according to a second embodiment. FIG. 8 is a cross-sectional view illustrating the configuration of a cross-section taken along line VIIIA-VIIIA or line VIIIB-VIIIB in FIG. 7, as viewed from the direction of the arrows. FIG. 9 is a cross-sectional view illustrating a configuration of a cut surface taken along line IX-IX in FIG. 7 as viewed from the direction of the arrows. FIG. 10 is a diagram illustrating a light distribution pattern formed by light emitted from the first emission surface. FIG. 11 is a diagram illustrating a light distribution pattern formed by light emitted from the second emission surface. FIG. 12 is a diagram illustrating a light distribution pattern formed by light emitted from the third emission surface. FIG. 13 is a plan view illustrating a configuration of an optical unit according to a third embodiment. FIG. 15 is a cross-sectional view illustrating a configuration of a cut surface taken along line XIV-XIV in FIG. 14 as viewed from the direction of the arrows.

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. For the sake of convenience, the dimensions of each component shown in the drawings may differ from the actual dimensions of each component. 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 backward direction. The symbol L indicates the leftward direction. The symbol R indicates the rightward direction. These directions are relative directions set for the optical unit 1 illustrated in FIG. 1, and the direction of light emitted from the optical unit 1 is defined as the forward direction.

[0011] First Embodiment FIG. 1 is a plan view illustrating the configuration of an optical unit 1 according to a first embodiment. FIG. 2 is a cross-sectional view illustrating the configuration of a cross-section taken along line IIA-IIA or line IIB-IIB in FIG. 1 , as viewed from the direction of the arrows. The cross-sections of the optical unit 1 taken along line IIA-IIA and line IIB-IIB have the same shape, and FIG. 2 illustrates both of these cross-sections. FIGS. 1 and 2 illustrate portions of light L1 and L2 that are emitted from the light source 10, pass through the light guide 30, and are emitted to the outside. However, FIG. 1 omits the illustration of light L1 and L2 that is emitted from the light source 10 and enters the light guide 30.

[0012] The optical unit 1 is mounted in a vehicle headlamp and configured to form a low-beam light distribution pattern.

[0013] 1, the optical unit 1 includes a light source 10, an optical member 20, and a light guide 30. The light source 10 is, for example, an LED (Light Emitting Diode) element or an LD (Laser Diode) element.

[0014] 2 , the optical member 20 is configured to convert the light beams L1 and L2 emitted from the light source 10 into parallel light beams. The optical member 20 has a reflecting surface 21 at a position facing the light source 10. The reflecting surface 21 converts the light beams L1 and L2 emitted from the light source 10 into parallel light beams and reflects them toward the light guide 30.

[0015] In the illustrated example, the optical member 20 is a parabolic reflector. The reflecting surface 21 is a paraboloid having an axis extending in the front-to-rear direction. The light source 10 is disposed on this axis. The light beams L1 and L2 emitted from the light source 10 while diffusing backward are reflected downward by the reflecting surface 21 as parallel beams.

[0016] The light guide 30 is made of a transparent material that transmits light. The light L1 and L2 emitted as parallel light from the optical member 20 are incident on the light guide 30. The light guide 30 is configured to guide the light L1 and L2 emitted from the optical member 20 forward.

[0017] The light guide 30 integrally has an incident surface 31, a plurality of exit surfaces 32, a plurality of reflecting surfaces 33, and a plurality of cutoff line forming portions 34. The incident surface 31 is a surface onto which the light beams L1 and L2 emitted as parallel light from the optical member 20 are incident. The incident surface 31 is disposed opposite the reflecting surface 21 of the optical member 20. The light beams L1 and L2 incident on the incident surface 31 are guided into the light guide 30.

[0018] A plurality of exit surfaces 32 are provided on the front surface of the light guide 30. Each exit surface 32 forms a single lens surface. Each exit surface 32 is formed so as to be convex forward. Each exit surface 32 emits the parallel light beams L1 and L2 that have entered the light guide 30 forward. The focal position of each exit surface 32 is located near the cutoff line forming portion 34.

[0019] 1 , two first exit surfaces 321 and one second exit surface 322 are provided on the front surface of the light guide 30 as the multiple exit surfaces 32. A first optical axis A1 of the first exit surface 321 and a second optical axis A2 of the second exit surface 322 extend parallel to each other. Note that the optical axis of the exit surface 32 here refers to a straight line that coincides with the normal to the most protruding portion of the forward-convex exit surface 32.

[0020] A plurality of reflecting surfaces 33 are provided on the rear surface of the light guide 30. Each reflecting surface 33 is configured to reflect light L1, L2 incident on the light guide 30 from the optical member 20 and cause the light L1, L2 to be incident on the opposite light exit surface 32. The reflecting surface 33 is, for example, a total reflection surface. The focal position of each reflecting surface 33 is located near the cutoff line forming portion 34.

[0021] In this example, two first reflecting surfaces 331 and one second reflecting surface 332 are provided on the rear surface of the light guide 30 as the multiple reflecting surfaces 33. The first reflecting surface 331 reflects light L1 incident on the light guide 30 and makes it incident on the opposing first exit surface 321. The second reflecting surface 332 reflects light L2 incident on the light guide 30 and makes it incident on the opposing second exit surface 322.

[0022] Each cutoff line forming portion 34 is provided between the exit surface 32 and the reflecting surface 33 facing each other. The cutoff line forming portion 34 is configured to totally reflect a portion of the light that is reflected by the reflecting surface 33 and is about to enter the exit surface 32. As a result of the total reflection of a portion of the light by the cutoff line forming portion 34, the light distribution pattern formed by the light emitted from the exit surface 32 becomes a light distribution pattern having a cutoff line. A low-beam light distribution pattern is formed by superimposing a plurality of light distribution patterns formed by the light emitted from the plurality of exit surfaces 32.

[0023] As illustrated in FIG. 2 , the cutoff line forming portion 34 is a step portion provided on the lower surface of the light guide 30. The front portion of the lower surface of the light guide 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 lower surface of the light guide 30. Each cutoff line forming portion 34 is configured to have a shape corresponding to the cutoff line CL ( FIG. 5 ) of the low beam distribution pattern PL when viewed from the front. For example, the cutoff line forming portion 34 is configured to have a substantially Z-shape when viewed from the front. The cutoff line forming portion 34 is configured to totally reflect a portion of light by a total reflection surface extending rearward of the cutoff line forming portion 34, thereby preventing light from emitting above the low beam distribution pattern.

[0024] 2, in the optical unit 1 configured as described above, the first focal position F1 of the first reflecting surface 331 is located on or near the first optical axis A1 of the first exit surface 321 in side view. The second focal position F2 of the second reflecting surface 332 is located on or near the second optical axis A2 of the second exit surface 322 in side view.

[0025] 1 , the first focal position F1 of the first reflecting surface 331 is located on or near the first optical axis A1 of the first exit surface 321 in the top view. On the other hand, the second focal position F2 of the second reflecting surface 332 is deviated from the second optical axis A2 of the second exit surface 322 in the top view. In this example, the second focal position F2 of the second reflecting surface 332 is deviated to the right from the second optical axis A2 of the second exit surface 322. Note that, in the top view, the Z-shaped position of the cutoff line forming portion 34 with respect to the first optical axis A1 of the first exit surface 321 is the same as the Z-shaped position of the cutoff line forming portion 34 with respect to the second optical axis A2 of the second exit surface 322.

[0026] FIG. 3 illustrates a first light distribution pattern P1 formed on a virtual vertical screen positioned a predetermined distance from a vehicle equipped with a vehicle headlamp by light L1 emitted from the first emission surface 321. In FIG. 3, a V-V line indicates the vertical direction (the up-down direction in FIG. 3 ) of the center of the illumination range of the vehicle headlamp, and an H-H line extends horizontally (the left-right direction in FIG. 3 ) perpendicular to the V-V line. In the light distribution pattern shown in FIG. 3 , different hatching is used for each region having a predetermined range of luminous intensity, with the region having higher luminous intensity being represented as being darker. A similar display method is used in subsequent figures illustrating light distribution patterns.

[0027] As illustrated in FIG. 3 , the first light distribution pattern P1 has a cutoff line CL1. A first hot zone H1 of the first light distribution pattern P1 extends in the left-right direction across an elbow point E1 of the first light distribution pattern P1. The hot zone is an area in the light distribution pattern where the luminous intensity is 90% or more of the maximum luminous intensity. The elbow point is a point where the horizontal cutoff line on the oncoming vehicle side of the cutoff line and the oblique cutoff line on the own vehicle side of the cutoff line intersect. The elbow point E1 of the first light distribution pattern P1 is located at the same position as the elbow point E (see FIG. 5 ) of the low-beam light distribution pattern PL formed by the light emitted by the optical unit 1.

[0028] For example, the first light distribution pattern P1 is formed so that the maximum luminous intensity in the first hot zone H1 is located within a range of ±1 degree on the H-H line (horizontal direction). Note that the position on the H-H line that intersects the V-V line at right angles is defined as 0 degrees. In other words, by positioning the first focal position F1 of the first reflecting surface 331 on or near the first optical axis A1 of the first exit surface 321 in a top view, it is possible to form the first light distribution pattern P1 whose maximum luminous intensity is located within a range of ±1 degree on the H-H line.

[0029] Fig. 4 illustrates a second light distribution pattern P2 formed on a virtual vertical screen by light emitted from the second emission surface 322. As illustrated in Fig. 4, the second light distribution pattern P2 has a cutoff line CL2. An elbow point E2 of the second light distribution pattern P2 is located at the same position as the elbow point E (see Fig. 5) of the low-beam light distribution pattern PL formed by light emitted by the optical unit 1.

[0030] The second hot zone H2 of the second light distribution pattern P2 is located closer to the vehicle's lane than the first hot zone H1 of the first light distribution pattern P1. In this example, the second hot zone H2 is shifted to the left of the first hot zone H1.

[0031] For example, the second light distribution pattern P2 is formed so that the maximum luminous intensity in the second hot zone H2 is located within a range of 2 to 5 degrees on the H-H line toward the vehicle's lane. In other words, by shifting the second focal position F2 of the second reflecting surface 332 from the optical axis of the second emitting surface 322 in a top view, it is possible to form the second light distribution pattern P2 whose maximum luminous intensity is located within a range of 2 to 5 degrees on the H-H line toward the vehicle's lane.

[0032] In addition, in the second light distribution pattern P2, the luminous intensity of the light irradiated to the area below and extending to the left and right of the second hot zone H2 is low, so the position of the second light distribution pattern P2 as a whole is substantially the same as the position of the first light distribution pattern P1 as a whole.

[0033] 5 illustrates a low-beam light distribution pattern PL formed on a virtual vertical screen by the optical unit 1. The low-beam light distribution pattern PL is formed by superimposing a first light distribution pattern P1 formed by light emitted from each first emission surface 321 of the optical unit 1 and a second light distribution pattern P2 formed by light emitted from the second emission surface 322. The hot zone H of the low-beam light distribution pattern PL is formed by superimposing a first hot zone H1 and a second hot zone H2.

[0034] As described above, with the optical unit 1 according to this embodiment, the hot zone H of the low-beam distribution pattern PL formed by overlapping the first light distribution pattern P1 and the second light distribution pattern P2 spreads in the left-right direction. As a result, even if the lamp is designed to be short in the vertical direction from the standpoint of the overall design of the lamp, a desired low-beam distribution pattern PL with a hot zone H that spreads left and right can be formed. Therefore, a vehicle headlamp that easily forms a desired low-beam distribution pattern can be provided.

[0035] 6 is a schematic diagram showing a low-beam light distribution pattern PL, viewed from above, illuminated by light emitted from a vehicle headlamp 2 having an optical unit 1 mounted on a vehicle 100. In this example, the vehicle headlamp 2 is mounted on each of the left and right sides of the front of the vehicle 100.

[0036] 6, the low-beam light distribution pattern PL10 indicated by the dashed line is a low-beam light distribution pattern formed by light emitted from a vehicle headlamp having an optical unit in which the optical axes of each exit surface are not deviated from the focal positions of the reflecting surfaces. On the other hand, the low-beam light distribution pattern PL indicated by the solid line is a low-beam light distribution pattern formed by light emitted from a vehicle headlamp 2 having an optical unit 1 in which the second optical axis A2 of the second exit surface 322 is deviated from the second focal position F2 of the second reflecting surface 332.

[0037] As illustrated in FIG. 6 , the low-beam light distribution pattern PL formed by the light emitted from the vehicle headlamp 2 according to this embodiment has a smaller maximum luminous intensity (i.e., a shorter long-distance reach) than the low-beam light distribution pattern PL10, but the brightness of the road shoulder 101 at a medium distance is improved.

[0038] In this embodiment, the optical unit 1 has two first exit surfaces 321 and one second exit surface 322. However, the number and arrangement of the first exit surfaces 321 and second exit surfaces 322 of the optical unit 1 are not limited to the number and arrangement of the present embodiment.

[0039] In the present embodiment, the first exit surface 321, the first reflecting surface 331, and the second exit surface 322, and the second reflecting surface 332 are formed in the light guide 30 of one optical unit 1. However, when a vehicle headlamp includes multiple optical units, for example, the multiple first exit surfaces 321, the multiple first reflecting surfaces 331, and the multiple second exit surfaces 322, and the multiple second reflecting surfaces 332 may be formed in different optical units. That is, the multiple first exit surfaces 321 and the multiple first reflecting surfaces 331 may be formed in the light guide of one optical unit, and the multiple second exit surfaces 322 and the multiple second reflecting surfaces 332 may be formed in the light guide of another optical unit.

[0040] Second Embodiment Fig. 7 is a plan view illustrating the configuration of an optical unit 1A according to a second embodiment. Fig. 8 is a cross-sectional view illustrating the configuration of a cut surface taken along line VIIIA-VIIIA or a cut surface taken along line VIIIB-VIIIB in Fig. 7, as viewed from the direction of the arrows. Fig. 9 is a cross-sectional view illustrating the configuration of a cut surface taken along line IX-IX in Fig. 7, as viewed from the direction of the arrows. Note that the cut surfaces of the optical unit 1A taken along line VIIIA-VIIIA and line VIIIB-VIIIB have the same shape, and both cut surfaces are shown in Fig. 7.

[0041] 7 to 9 show some of the light L11 and L12 emitted from the light source 10, passing through the light guide 40, and being emitted to the outside, but FIG. 7 does not show the light L11 and L12 emitted from the light source 10 until it enters the light guide 40.

[0042] In the description of this embodiment, the same reference numerals are used to designate components having the same functions as those in the first embodiment, and for the sake of convenience, detailed description thereof will be omitted.

[0043] The optical unit 1A is mounted in a vehicle headlamp and is configured to form a high beam light distribution pattern. As shown in FIG. 7 , the optical unit 1A includes a light source 10, an optical member 20, and a light guide 40.

[0044] 8 and 9 , the optical member 20 is configured to convert the light beams L11 and L12 emitted from the light source 10 into parallel light beams. The optical member 20 has a reflecting surface 21 located opposite the light source 10. The reflecting surface 21 converts the light beams L11 and L12 emitted from the light source 10 into parallel light beams and reflects them toward the light guide 40. The light beams L11 and L12 emitted from the light source 10 while diffusing toward the rear are reflected downward by the reflecting surface 21 as parallel light beams.

[0045] The light guide 40 is made of a transparent material that transmits light. The light beams L11 and L12 that are emitted as parallel light beams from the optical member 20 are incident on the light guide 40. The light guide 40 is configured to guide the light beams L11 and L12 that are emitted from the optical member 20 forward.

[0046] The light guide 40 integrally has an incident surface 41, a plurality of exit surfaces 42, a plurality of reflecting surfaces 43, and a plurality of cutoff line forming portions 34. The incident surface 41 is a surface onto which the light beams L11 and L12 emitted as parallel light from the optical member 20 are incident. The incident surface 41 is disposed opposite the reflecting surface 21 of the optical member 20. The light beams L11 and L12 incident on the incident surface 41 are guided into the light guide 40.

[0047] A plurality of exit surfaces 42 are provided on the front surface of the light guide 40. Each exit surface 42 forms a single lens surface. Each exit surface 42 is formed so as to be convex forward. Each exit surface 42 emits the parallel light beams L11 and L12 that have entered the light guide 40 forward.

[0048] 1 , a first exit surface 421, a second exit surface 422, and a third exit surface 423 are provided as a plurality of exit surfaces 42 on the front surface of the light guide 40. A first optical axis A11 of the first exit surface 421, a second optical axis A12 of the second exit surface 422, and a third optical axis A13 of the third exit surface 423 extend parallel to each other.

[0049] A plurality of reflecting surfaces 43 are provided on the rear surface of the light guide 40. Each reflecting surface 43 is configured to reflect light L11, L12, and L13 incident on the light guide 40 from the optical member 20, and cause the light to be incident on the opposite exit surface 42. The reflecting surfaces 43 are, for example, total reflection surfaces.

[0050] In this example, the multiple reflective surfaces 43, including a first reflective surface 431, a second reflective surface 432, and a third reflective surface 433, are provided on the rear surface of the light guide 40. The first reflective surface 431 reflects light L1 incident on the light guide 40, causing it to be incident on the opposing first exit surface 421. The second reflective surface 432 reflects light L2 incident on the light guide 40, causing it to be incident on the opposing second exit surface 422. The third reflective surface 433 reflects light L3 incident on the light guide 40, causing it to be incident on the opposing third exit surface 423.

[0051] In the optical unit 1A configured as described above, as illustrated in Fig. 8, the first focal position F11 of the first reflecting surface 431 is located on or near the first optical axis A11 of the first exit surface 421 in side view. The second focal position F12 of the second reflecting surface 432 is located on or near the second optical axis A12 of the second exit surface 422 in side view. As illustrated in Fig. 9, the third focal position F13 of the third reflecting surface 433 is shifted downward from the third optical axis A13 of the third exit surface 423.

[0052] 7 , the first focal position F11 of the first reflecting surface 431 is located on or near the first optical axis A11 of the first exit surface 421 in the top view. The third focal position F13 of the third reflecting surface 433 is located on or near the third optical axis A13 of the third exit surface 423 in the top view. On the other hand, the second focal position F12 of the second reflecting surface 432 is shifted from the second optical axis A12 of the second exit surface 422 in the top view. In this example, the second focal position F12 of the second reflecting surface 432 is shifted to the right from the second optical axis A12 of the second exit surface 422.

[0053] 10 illustrates a light distribution pattern P11 formed on a virtual vertical screen located at a predetermined distance from a vehicle equipped with a vehicle headlamp by light L11 emitted from the first emission surface 421. The light distribution pattern P11 is an example of a first light distribution pattern.

[0054] 10, a hot zone H11 of the light distribution pattern P11 extends in the left-right and up-down directions from the point where the VV line and the HH line intersect. The hot zone H11 is an example of a first hot zone.

[0055] For example, the light distribution pattern P11 is formed so that the maximum luminous intensity in the hot zone H11 is located within a range of ±1 degree on the H-H line (horizontal direction) and within a range of ±1 degree on the V-V line (vertical direction). In other words, by positioning the first focal position F11 of the first reflecting surface 431 on or near the first optical axis A11 of the first exit surface 421 in a top view, it is possible to form a light distribution pattern P11 whose maximum luminous intensity is located within a range of ±1 degree on the H-H line. Furthermore, by positioning the first focal position F11 of the first reflecting surface 431 on or near the first optical axis A11 of the first exit surface 421 in a side view, it is possible to form a light distribution pattern P11 whose maximum luminous intensity is located within a range of ±1 degree on the V-V line.

[0056] 11 illustrates a light distribution pattern P12 formed on a virtual vertical screen by light emitted from the second emission surface 422. The light distribution pattern P12 is an example of a second light distribution pattern.

[0057] 11 , the light distribution pattern P12 is located closer to the vehicle's lane than the light distribution pattern P11. The hot zone H12 of the light distribution pattern P12 is located closer to the vehicle's lane than the hot zone H11 of the light distribution pattern P11. In this example, the hot zone H12 is shifted to the left of the hot zone H11. The hot zone H12 is an example of a second hot zone.

[0058] For example, the light distribution pattern P12 is formed so that the maximum luminous intensity in the hot zone H12 is located within a range of 2 to 5 degrees on the H-H line toward the vehicle's lane. In other words, by shifting the second focal position F12 of the second reflecting surface 432 from the second optical axis A12 of the second exit surface 422 in a top view, it is possible to form the light distribution pattern P12 whose maximum luminous intensity is located within a range of 2 to 5 degrees on the H-H line toward the vehicle's lane.

[0059] 12 illustrates a light distribution pattern P13 formed on a virtual vertical screen by light emitted from the third emission surface 423. The light distribution pattern P13 is an example of a third light distribution pattern.

[0060] 12, the light distribution pattern P13 is located above the light distribution pattern P11. The hot zone H13 of the light distribution pattern P13 is located above the hot zone H11 of the light distribution pattern P11. The hot zone H13 is an example of a third hot zone.

[0061] For example, light distribution pattern P13 is formed so that the maximum luminous intensity in hot zone H13 is located in a range of 2 to 5 degrees upward on line V-V. In other words, by displacing third focal position F13 of third reflecting surface 433 downward from third optical axis A13 of third exit surface 423 in side view, it is possible to form light distribution pattern P13 whose maximum luminous intensity is located in a range of 2 to 5 degrees upward on line V-V.

[0062] 13 illustrates a high-beam light distribution pattern PH formed on a virtual vertical screen by the optical unit 1A. The high-beam light distribution pattern PH is formed by superimposing a light distribution pattern P11 formed by light emitted from the first emission surface 421 of the optical unit 1A, a light distribution pattern P12 formed by light emitted from the second emission surface 422, and a light distribution pattern P13 formed by light emitted from the third emission surface 423. A hot zone H10 of the high-beam light distribution pattern PH is formed by superimposing hot zones H11, H12, and H13.

[0063] As described above, with the optical unit 1A according to this embodiment, the hot zone H10 of the high-beam distribution pattern PH formed by overlapping the light distribution patterns P11, P12, and P13 spreads left and right and upward. This allows a desired high-beam distribution pattern PH with the hot zone H10 spreading left and right and upward to be formed, even in a lamp that is designed to be short in the vertical direction from the standpoint of the overall lamp design. Therefore, a vehicle headlamp that easily forms a desired high-beam distribution pattern can be provided.

[0064] In this embodiment, optical unit 1A has one first exit surface 421, one second exit surface 422, and one third exit surface 423. However, the number and arrangement of first exit surface 421, second exit surface 422, and third exit surface 423 of optical unit 1A are not limited to the number and arrangement of this embodiment.

[0065] In the present embodiment, the first exit surface 421 and the first reflecting surface 431, the second exit surface 422 and the second reflecting surface 432, and the third exit surface 423 and the third reflecting surface 433 are formed on the light guide 40 of one optical unit 1A. However, when a vehicle headlamp includes a plurality of optical units, for example, the plurality of first exit surfaces 421 and the plurality of first reflecting surfaces 431, the plurality of second exit surfaces 422 and the plurality of second reflecting surfaces 432, and the plurality of third exit surfaces 423 and the plurality of third reflecting surfaces 433 may be formed on different optical units.

[0066] Third Embodiment Fig. 14 is a plan view illustrating the configuration of an optical unit 1B according to a third embodiment. Fig. 15 is a cross-sectional view illustrating the configuration of a cut surface along line XIV-XIV in Fig. 14, as viewed from the direction of the arrows. Note that the cut surface along the line passing through first reflecting surface 331 and first exit surface 321 and the cut surface along the line passing through second reflecting surface 332 and second exit surface 322 are the same as the cut surfaces shown in Fig. 2, and therefore are not shown in the figures.

[0067] 14 and 15 show some of the light L1, L2, and L3 emitted from the light source 10, passing through the light guide 30A, and being emitted to the outside, but FIG. 14 does not show the light L1, L2, and L3 emitted from the light source 10 until it enters the light guide 30A.

[0068] In the description of this embodiment, the same reference numerals are used to designate components having the same functions as those in the first embodiment, and for the sake of convenience, detailed description thereof will be omitted.

[0069] The optical unit 1B is mounted on a vehicle headlamp and is configured to form a low beam light distribution pattern and an OHS light distribution pattern.

[0070] 14, the optical unit 1B includes a light source 10, an optical member 20, and a light guide 30A. The light source 10 is, for example, an LED (Light Emitting Diode) element or an LD (Laser Diode) element.

[0071] 15 , the optical member 20 is configured to convert the light beams L1, L2, and L3 emitted from the light source 10 into parallel light beams. The optical member 20 has a reflecting surface 21 located opposite the light source 10. The reflecting surface 21 converts the light beams L1, L2, and L3 emitted from the light source 10 into parallel light beams and reflects them toward the light guide 30A. The light beams L1, L2, and L3 emitted from the light source 10 while diffusing toward the rear are reflected downward by the reflecting surface 21 as parallel light beams.

[0072] The light guide 30A is made of a transparent material that transmits light. The light guide 30A receives the parallel light beams L1, L2, and L3 emitted from the optical member 20. The light guide 30A is configured to guide the light beams L1, L2, and L3 emitted from the optical member 20 forward.

[0073] The light guide 30A integrally has an incident surface 31, a plurality of exit surfaces 32, a plurality of reflecting surfaces 33, and a plurality of cutoff line forming portions 34. The incident surface 31 is a surface onto which the light beams L1, L2, and L3 emitted as parallel light from the optical member 20 are incident. The incident surface 31 is disposed opposite the reflecting surface 21 of the optical member 20. The light beams L1, L2, and L3 incident on the incident surface 31 are guided into the light guide 30A.

[0074] A plurality of exit surfaces 32 are provided on the front surface of the light guide 30A. Each exit surface 32 forms a single lens surface. Each exit surface 32 is formed so as to be convex forward. Each exit surface 32 emits the parallel light beams L1, L2, and L3 that have entered the light guide 30A forward. The focal position of each exit surface 32 is located near the cutoff line forming portion 34.

[0075] 14 , a first exit surface 321, a second exit surface 322, and a third exit surface 323 are provided on the front surface of the light guide 30A as a plurality of exit surfaces 32. A first optical axis A1 of the first exit surface 321, a second optical axis A2 of the second exit surface 322, and a third optical axis A3 of the third exit surface 323 extend parallel to one another.

[0076] The plurality of reflecting surfaces 33 are provided on the rear surface of the light guide 30A. Each reflecting surface 33 is configured to reflect the light beams L1, L2, and L3 incident on the light guide 30A from the optical member 20, and cause the light beams to be incident on the opposite light exit surface 32. The reflecting surfaces 33 are, for example, total reflection surfaces. The focal positions of the reflecting surfaces 33 are located near the cutoff line forming portion 34.

[0077] In this example, the multiple reflective surfaces 33, including a first reflective surface 331, a second reflective surface 332, and a third reflective surface 333, are provided on the rear surface of the light guide 30A. The first reflective surface 331 reflects light L1 incident on the light guide 30A and makes it incident on the opposing first exit surface 321. The second reflective surface 332 reflects light L2 incident on the light guide 30A and makes it incident on the opposing second exit surface 322. The third reflective surface 333 reflects light L3 incident on the light guide 30A and makes it incident on the opposing third exit surface 323.

[0078] Each cutoff line forming portion 34 is provided between the exit surface 32 and the reflecting surface 33 facing each other. The cutoff line forming portion 34 is configured to totally reflect a portion of the light that is reflected by the reflecting surface 33 and is about to enter the exit surface 32. As a result of the total reflection of a portion of the light by the cutoff line forming portion 34, the light distribution pattern formed by the light emitted from the exit surface 32 becomes a light distribution pattern having a cutoff line. A low-beam light distribution pattern is formed by superimposing a plurality of light distribution patterns formed by the light emitted from the plurality of exit surfaces 32.

[0079] As illustrated in FIG. 15 , the cutoff line forming portion 34 is a step portion provided on the lower surface of the light guide 30A. The front portion of the lower surface of the light guide 30A 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 lower surface of the light guide 30A. Each cutoff line forming portion 34 is configured to have a shape corresponding to the cutoff line of the low beam distribution pattern when viewed from the front. For example, the cutoff line forming portion 34 is configured to have a substantially Z-shape when viewed from the front. The cutoff line forming portion 34 is configured to totally reflect a portion of light by a total reflection surface extending rearward of the cutoff line forming portion 34, thereby preventing light from emitting above the low beam distribution pattern.

[0080] 2, in the optical unit 1B configured as described above, the first focal position F1 of the first reflecting surface 331 is located on or near the first optical axis A1 of the first exit surface 321 in side view. The second focal position F2 of the second reflecting surface 332 is located on or near the second optical axis A2 of the second exit surface 322 in side view.

[0081] 14 , the first focal position F1 of the first reflecting surface 331 is located on or near the first optical axis A1 of the first exit surface 321 in the top view. On the other hand, the second focal position F2 of the second reflecting surface 332 is shifted from the second optical axis A2 of the second exit surface 322 in the top view.

[0082] With this configuration, the low beam distribution pattern PL formed by superimposing the first light distribution pattern P1 formed by the light emitted from the first exit surface 321 and the second light distribution pattern P2 formed by the light emitted from the second exit surface 322 becomes a low beam distribution pattern in which the hot zone H extends in the left and right directions, as illustrated in Figure 5.

[0083] 14 , the third focal position F3 of the third reflecting surface 333 is located on or near the third optical axis A3 of the third exit surface 323 in a top view. On the other hand, as illustrated in FIG. 15 , the third focal position F3 of the third reflecting surface 333 is deviated from the third optical axis A3 of the third exit surface 323 in a side view. In this example, the third focal position F3 of the third reflecting surface 333 is deviated downward from the third optical axis A3 of the third exit surface 323. The third optical axis A3 of the third exit surface 323 is deviated upward from the first optical axis A1 of the first exit surface 321 and the second optical axis A2 of the second exit surface 322.

[0084] With this configuration, an OHS (Over Head Sign) light distribution pattern can be formed above the low-beam light distribution pattern PL by the light emitted from the third light exit surface 323. The OHS light distribution pattern is an example of a third light distribution pattern. That is, an optical unit 1B for a vehicle headlamp is provided that can simultaneously form the shape of a low-beam light distribution pattern and an OHS light distribution pattern.

[0085] In this embodiment, optical unit 1B has one first exit surface 321, one second exit surface 322, and one third exit surface 323. However, the number and arrangement of first exit surface 321, second exit surface 322, and third exit surface 323 of optical unit 1B are not limited to the number and arrangement of this embodiment.

[0086] In the present embodiment, the first exit surface 321 and the first reflecting surface 331, the second exit surface 322 and the second reflecting surface 332, and the third exit surface 323 and the third reflecting surface 333 are formed in the light guide 30 of one optical unit 1. However, when a vehicle headlamp includes a plurality of optical units, for example, the plurality of first exit surfaces 321 and the plurality of first reflecting surfaces 331, the plurality of second exit surfaces 322 and the plurality of second reflecting surfaces 332, and the plurality of third exit surfaces 323 and the plurality of third reflecting surfaces 333 may be formed in different optical units.

[0087] 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.

[0088] In each of the above-described embodiments, one or more light sources 10 may be provided for the light guide 30, 30A, or 40.

[0089] The configurations described in the following items also constitute part of the present disclosure. Item 1: A vehicle headlamp that forms a light distribution pattern, comprising: a light source; an 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 optical element is incident, wherein the light guide has: a first emission surface provided on a front surface of the light guide; a second emission surface provided on the front surface of the light guide; a first reflection surface provided on a rear surface of the light guide, the first reflection surface reflecting the light that has entered the light guide from the optical element to the first emission surface; and a second reflection surface provided on the rear surface of the light guide, the second reflection surface reflecting the light that has entered the light guide from the optical element to the second emission surface, wherein the focal position of the first reflection surface is located on or near the optical axis of the first emission surface, and the focal position of the second reflection surface is deviated from the optical axis of the second emission surface. Item 2: The vehicle headlamp according to Item 1, wherein, in a top view, a focal position of the second reflecting surface is deviated from an optical axis of the second exit surface. Item 3: The vehicle headlamp according to Item 1 or 2, wherein the light guide has a third exit surface provided on a front surface of the light guide, and a third reflecting surface provided on a rear surface of the light guide, the third reflecting surface reflecting light that has entered the light guide from the optical member to the third exit surface, and wherein, in a side view, a focal position of the third reflecting surface is deviated from the optical axis of the third exit surface. Item 4: A vehicle headlamp that forms a light distribution pattern, comprising a light guide having a first emission surface that emits light to form a first light distribution pattern including a first hot zone, and a second emission surface that emits light to form a second light distribution pattern including a second hot zone, wherein the light distribution pattern is formed by superimposing the first light distribution pattern and the second light distribution pattern, and the hot zone of the light distribution pattern is formed by superimposing the first hot zone and the second hot zone, and the second hot zone of the second light distribution pattern is offset from the first hot zone of the first light distribution pattern.Item 5: The vehicle headlamp according to Item 4, wherein the second hot zone of the second light distribution pattern is offset in the left-right direction from the first hot zone of the first light distribution pattern. Item 6: The vehicle headlamp according to Item 4 or Item 5, wherein the light guide has a third emission surface that emits light to form a third light distribution pattern including a third hot zone, the light distribution pattern is formed by superimposing the first light distribution pattern, the second light distribution pattern, and the third light distribution pattern, and the hot zone of the light distribution pattern is formed by superimposing the first hot zone, the second hot zone, and the third hot zone, and the third hot zone of the third light distribution pattern is offset in the up-down direction from the first hot zone of the first light distribution pattern. Item 7: The vehicle headlamp according to any one of Items 1 to 6, wherein the light distribution pattern is a low-beam light distribution pattern. Item 8: The vehicle headlamp according to any one of items 4 to 6, wherein the first hot zone extends in the left-right direction across an elbow point of the low-beam light distribution pattern on a virtual vertical screen arranged at a position a predetermined distance from the vehicle, and the second hot zone is located closer to the vehicle's lane than the first hot zone. Item 9: The vehicle headlamp according to any one of items 1 to 6, wherein the light distribution pattern is a high-beam light distribution pattern.

[0090] This application is based on Japanese Patent Application No. 2024-110740 filed on July 10, 2024, the contents of which are incorporated herein by reference.

Claims

1. A vehicle headlamp that forms a light distribution pattern, comprising: a light source; an 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 optical element is incident, wherein the light guide has: a first exit surface provided on the front surface of the light guide; a second exit surface provided on the front surface of the light guide; a first reflecting surface provided on the rear surface of the light guide, which reflects light that has entered the light guide from the optical element so that the light is incident on the first exit surface; and a second reflecting surface provided on the rear surface of the light guide, which reflects light that has entered the light guide from the optical element so that the light is incident on the second exit surface, wherein the focal position of the first reflecting surface is located on or near the optical axis of the first exit surface, and the focal position of the second reflecting surface is deviated from the optical axis of the second exit surface.

2. The vehicle headlamp according to claim 1, wherein, in a top view, the focal position of the second reflecting surface is shifted from the optical axis of the second light exit surface.

3. A vehicle headlamp as claimed in claim 1 or 2, wherein the light guide has a third exit surface provided on the front surface of the light guide, and a third reflecting surface provided on the rear surface of the light guide, which reflects light that has entered the light guide from the optical element and makes it enter the third exit surface, and wherein, in a side view, the focal position of the third reflecting surface is shifted from the optical axis of the third exit surface.

4. A vehicle headlamp that forms a light distribution pattern, comprising a light guide having a first exit surface that emits light to form a first light distribution pattern including a first hot zone, and a second exit surface that emits light to form a second light distribution pattern including a second hot zone, wherein the light distribution pattern is formed by superimposing the first light distribution pattern and the second light distribution pattern, the hot zone of the light distribution pattern is formed by superimposing the first hot zone and the second hot zone, and the second hot zone of the second light distribution pattern is offset from the first hot zone of the first light distribution pattern.

5. The vehicle headlamp according to claim 4, wherein the second hot zone of the second light distribution pattern is shifted in the left-right direction from the first hot zone of the first light distribution pattern.

6. A vehicle headlamp as claimed in claim 4 or 5, wherein the light guide has a third exit surface that emits light so as to form a third light distribution pattern including a third hot zone, the light distribution pattern is formed by superimposing the first light distribution pattern, the second light distribution pattern and the third light distribution pattern, the hot zone of the light distribution pattern is formed by superimposing the first hot zone, the second hot zone and the third hot zone, and the third hot zone of the third light distribution pattern is shifted in the vertical direction from the first hot zone of the first light distribution pattern.

7. The vehicle headlamp according to claim 4, wherein the light distribution pattern is a low beam light distribution pattern.

8. A vehicle headlamp as described in claim 7, wherein the first hot zone extends in left and right directions on either side of an elbow point of the low beam light distribution pattern on a virtual vertical screen positioned at a predetermined distance from the vehicle, and the second hot zone is located closer to the vehicle's lane than the first hot zone.

9. A vehicle headlamp according to claim 1 or claim 4, wherein the light distribution pattern is a high beam light distribution pattern.

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