Light source distribution element for headlamp device and headlamp module

Abstract

A light source distribution element (100) for a headlight device comprises: an incident unit (110) to which light from a light source (1) is inputted and which has three or more joining surfaces (111) to (115) located along one direction on a plane orthogonal to the optical axis of the light source (1); and three or more light-guiding units (121) to (125) that each have a rectangular cross section and each have a pair of opposed surfaces facing each other in another direction orthogonal to the one direction on the plane orthogonal to the optical axis of the light source (1), that have emission surfaces (121a) to (125a) corresponding to the plurality of joining surfaces (111) to (115) of the incident unit (110), respectively, and that guide light from the corresponding joining surfaces (111) to (115) to the corresponding emission surfaces (121a) to (125a). Among the plurality of light-guiding units (121) to (125), the pairs of opposed surfaces, at which the emission surfaces (122a), (123a) are located, of the light-guiding units (122), (123) on one end side in another direction with respect to the light source (1) have pairs of reflection surfaces (122b), (122c), (123b), (123c) inclined with respect to the optical axis of the light source (1), on the one end side. Among the plurality of light-guiding units (121) to (125), the pairs of opposed surfaces, at which the emission surfaces (124a), (125a) are located, of the light-guiding units (124), (125) on the other end side in the other direction with respect to the light source (1) have pairs of reflection surfaces (124b), (124c), (125b), (125c) inclined with respect to the optical axis of the light source (1), on the other end side.

Description

[Technical Field]

[0001] The present disclosure relates to a light source distribution element and a headlight module used in a headlight device that illuminates the area ahead of a vehicle body. [Background technology]

[0002] BACKGROUND ART Headlight devices that illuminate the area ahead of a vehicle body, so-called headlight devices, particularly low-beam headlights and high-beam headlights, are desired to be thin and have improved light utilization efficiency. Patent Document 1 proposes a light source distribution element for a headlamp device that has a simplified structure and is compact without reducing light utilization efficiency.

[0003] The light source distribution element for a headlamp device proposed in Patent Document 1 includes a first light guiding section located between the first bonding surface of the incident section and the first exit section, and guiding light from the first bonding surface of the incident section to the first exit section; and a second light guiding section located between the second bonding surface of the incident section and the second exit section, and having a first reflecting surface formed on one of the opposing side surfaces in the other direction and a second reflecting surface formed on the other of the opposing side surfaces in the other direction, and reflecting the light from the second bonding surface of the incident section by the first reflecting surface and the second reflecting surface to guide it to the second exit section. The light source distribution element for a headlamp device proposed in Patent Document 1 has a simple structure and can be made smaller without reducing the light utilization efficiency. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7,031,087 Summary of the Invention [Problem to be solved by the invention]

[0005] There is a demand for light source distribution elements and headlight modules with even lower heights for vehicle headlight devices, and the present disclosure has been made in response to such demands, with the objective of obtaining a light source distribution element for a headlight device that has a simplified structure and is even smaller without reducing light utilization efficiency. [Means for solving the problem]

[0006] The light source distribution element for a headlamp device according to the present disclosure comprises an entrance section into which light from a light source is incident and which has three or more bonding surfaces located along one direction in a plane perpendicular to the optical axis of the light source, and three or more light guiding sections each having a rectangular cross-sectional shape with a pair of opposing surfaces facing one direction in the plane perpendicular to the optical axis of the light source and another direction perpendicular to the one direction in the plane perpendicular to the optical axis of the light source, each having an exit surface corresponding to one of the plurality of bonding surfaces of the entrance section, and each guiding light from the corresponding bonding surface to the corresponding exit surface, wherein of the plurality of light guiding sections, the pair of opposing surfaces of the light guiding section whose exit surface is located at one end side in the other direction relative to the light source has a pair of reflective surfaces on one end side that are inclined with respect to the optical axis of the light source, and among the plurality of light guiding sections, the pair of opposing surfaces of the light guiding section whose exit surface is located at the other end side in the other direction relative to the light source has a pair of reflective surfaces on the other end side that are inclined with respect to the optical axis of the light source. [Effects of the Invention]

[0007] According to the present disclosure, the structure can be simplified and further miniaturized without reducing the light utilization efficiency. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view showing a headlight module according to a first embodiment, viewed from above on the right side. [Figure 2] 1 is a perspective view showing a headlight module according to a first embodiment, viewed from below on the left side. [Figure 3] 1 is a front view showing a headlight module according to a first embodiment. [Figure 4] 1 is a top view showing a headlight module according to a first embodiment. [Figure 5]2 is a bottom view showing the headlight module according to the first embodiment. FIG. [Figure 6] 1 is a side view showing a headlight module according to a first embodiment. [Figure 7] 1 is a front view showing a part of a cross section of an incident portion of a headlight module according to a first embodiment. [Figure 8] 4 is a diagram showing an illuminance distribution at a joint surface in an incident portion of the headlight module according to the first embodiment. FIG. [Figure 9] 3 is a perspective view showing a light beam in the headlight module according to the first embodiment, as viewed from above on the right side. FIG. [Figure 10] 3 is a perspective view showing a light beam in the headlight module according to the first embodiment, as viewed from below on the left side. FIG. [Figure 11] FIG. 10 is a perspective view showing a headlight module according to a second embodiment, viewed from above on the right side. [Figure 12] FIG. 10 is a perspective view showing a headlight module according to a second embodiment, as viewed from below on the left side. [Figure 13] FIG. 10 is a front view showing a headlight module according to a second embodiment. [Figure 14] FIG. 10 is a top view showing a headlight module according to a second embodiment. [Figure 15] FIG. 10 is a bottom view showing a headlight module according to a second embodiment. [Figure 16] FIG. 10 is a side view showing a headlight module according to a second embodiment. [Figure 17] 10 is a perspective view showing a light beam in a headlamp module according to a second embodiment, as viewed from above on the right side. FIG. [Figure 18] 10 is a perspective view showing a light beam in a headlamp module according to a second embodiment, as viewed from below on the left side. FIG. [Figure 19] FIG. 11 is a perspective view showing a headlight module according to a third embodiment, viewed from above on the right side. [Figure 20] FIG. 11 is a perspective view showing a headlight module according to a third embodiment, as viewed from below on the left side. [Figure 21] FIG. 10 is a front view showing a headlight module according to a third embodiment. [Figure 22] FIG. 10 is a top view showing a headlight module according to a third embodiment. [Figure 23] FIG. 10 is a bottom view showing a headlight module according to a third embodiment. [Figure 24] FIG. 10 is a side view showing a headlight module according to a third embodiment. [Figure 25] 11 is an enlarged perspective view showing a light source distribution element and a light collecting optical unit in a headlamp module according to a third embodiment, as viewed from the right side. FIG. [Figure 26] 11 is an enlarged perspective view showing a light source distribution element and a light collecting optical unit in a headlamp module according to a third embodiment, as viewed from the left side. FIG. [Figure 27] FIG. 10 is a perspective view showing a headlight module according to a fourth embodiment, viewed from above on the right side. [Figure 28] FIG. 10 is a perspective view showing a headlight module according to a fourth embodiment, viewed from below on the left side. [Figure 29] FIG. 10 is a front view showing a headlight module according to a fourth embodiment. [Figure 30] FIG. 10 is a top view showing a headlight module according to a fourth embodiment. [Figure 31] FIG. 10 is a bottom view showing a headlight module according to a fourth embodiment. [Figure 32] FIG. 10 is a side view showing a headlight module according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Embodiment 1 A light source distribution element 100 for a headlamp device (hereinafter simply referred to as light source distribution element 100) and a headlamp module according to a first embodiment will be described with reference to FIGS. 1 to 10. FIG. The headlight module is used in headlight devices that illuminate the area ahead of automobiles, motorcycles, and three-wheeled vehicles known as gyros (scooters and motorized bicycles with one front wheel and two rear wheels on a single axle), and that satisfy specified light distribution patterns stipulated by road traffic regulations, etc. The headlamp device has a low beam and a high beam.

[0010] The headlamp module according to the first embodiment can be used for low beam and high beam, but is particularly suitable for use in low beam. In the following description, an example in which the present invention is applied to a low beam headlamp device for an automobile will be described. When applied to a low beam headlamp device for an automobile, the headlamp module may be one, or a plurality of headlamp modules may be arranged in parallel in the left-right direction.

[0011] Before specifically describing the light source distribution element 100 and the headlamp module, the terms used in this disclosure will be explained. Light distribution refers to the spatial distribution of luminous intensity of a light source, i.e., the spatial distribution of light emitted from a light source. Luminous intensity indicates the degree of strength of light emitted by a light source, and is calculated by dividing the luminous flux passing through a small solid angle in a certain direction by that small solid angle.

[0012] Road traffic regulations require that the low beams of automobile headlight devices and motorcycle headlight devices have a horizontally elongated light distribution pattern that is narrow in the vertical direction, and that the upper light boundary line of the light distribution pattern, i.e., the cut-off line, be clear so as not to dazzle drivers of oncoming vehicles. The light distribution pattern refers to the shape of the light flux and the light intensity distribution resulting from the direction of light emitted from the light source 1. The light distribution pattern is also used to mean the illuminance pattern on the illuminated surface. The luminous intensity distribution is the distribution of light intensity relative to the direction of light emitted from a light source. The luminous intensity distribution is also used to mean the illuminance distribution on an illuminated surface.

[0013] The required clear cutoff line means that the upper side of the cutoff line, i.e., the outside of the light distribution pattern, is dark, and the lower side of the cutoff line, i.e., the inside of the light distribution pattern, is bright.

[0014] The cut-off line is a dividing line between light and darkness that is created when light from a headlight device is projected onto a wall or a screen, and is the dividing line at the top of the light distribution pattern. That is, the cutoff line is the boundary line between the bright and dark areas of the upper part of the light distribution pattern. It is the boundary line between the bright area of ​​the upper part of the light distribution pattern, i.e., the inside of the light distribution pattern, and the dark area, i.e., the outside of the light distribution pattern. The cutoff line is a term used when adjusting the illumination direction of a passing headlight device. A passing headlight device is also called a low beam.

[0015] Low beams are required to have maximum illuminance in the area below the cutoff line, which is called the high illuminance area. The area below the cutoff line means the upper part of the light distribution pattern, which corresponds to the part of the headlamp device that irradiates a distant object. To achieve a clear cutoff line, the cutoff line must not have large chromatic aberration or blur, etc. Blurring of the cutoff line means that the cutoff line is unclear.

[0016] In a low beam headlamp device for an automobile, the cut-off line has a stepped shape with a rising line. In a low beam motorcycle headlamp device, the cutoff line is a horizontal straight line in the left-right direction of the vehicle, and the light distribution pattern is brightest below the cutoff line, i.e., in the area inside the light distribution pattern. Furthermore, because headlight devices are disposed at the front of an automobile, design is important, and there is a demand for headlight devices that offer increased freedom in design. If a headlamp device is designed to be thin in the vertical direction of the vehicle in order to enhance design, the light utilization efficiency will be low.

[0017] The light source distribution element 100 and headlight module according to embodiment 1 are made smaller without reducing light utilization efficiency by reducing the thickness of the light emission surface of the light source distribution element 100 in the vertical direction to enhance design, and by focusing on Abbe's invariant (Abbe's sine condition or the law of conservation of etendue). In other words, by making the light source distribution element 100 have three or more exit surfaces, preferably five exit surfaces, the length of one side of the exit surface of the light source distribution element 100, which acts as an apparent light source, can be made shorter, thereby achieving miniaturization.

[0018] In the following description, for ease of explanation, XYZ coordinates will be used. The left-right direction of the vehicle is the X-axis direction. The right side of the vehicle is the + direction of the X-axis, and the left side is the - direction of the X-axis. Here, "forward" refers to the direction in which the vehicle is traveling. In other words, "forward" refers to the direction in which the headlight device emits light. In the light-source distribution element 100 and headlight module according to the first embodiment, the X-axis direction is the other direction, with one end side being the negative direction (right side) and the other end side being the positive direction (left side). Although one end side is the right side and the other end side is the left side, this is specified for convenience of explanation, and one end side may be the left side and the other end side may be the right side.

[0019] The vertical direction of the vehicle is the Y-axis direction. The upper side is the + direction of the Y-axis, and the lower side is the - direction of the Y-axis. The upper side is the direction of the sky, and the lower side is the direction of the ground (road surface, etc.). The direction of travel of the vehicle is the Z-axis direction. The direction of travel is the + direction of the Z-axis, and the opposite direction is the - direction of the Z-axis. The + direction of the Z-axis is called the front, and the - direction of the Z-axis is called the rear. In other words, the + direction of the Z-axis is the direction in which the headlights emit light. In the light source distribution element 100 and headlight module according to embodiment 1, the Z-axis direction is one direction, with one end side being the + direction, which is the front when used for an automobile, and the other end side being the - direction, which is the rear when used for an automobile.

[0020] The ZX plane is parallel to the road surface. The road surface is usually considered to be a horizontal plane, that is, a plane perpendicular to the direction of gravity, although the road surface may be inclined relative to the direction of travel of the vehicle due to an uphill or downhill slope, for example.

[0021] Furthermore, although it is rare for a typical road surface to be inclined left or right with respect to the direction of travel of a vehicle, that is, in the width direction of the road, the road surface may be inclined left or right. Therefore, the horizontal plane, which is a plane parallel to the road surface, is not necessarily a plane perpendicular to the direction of gravity, but the following explanation will be given assuming that the horizontal plane is a plane perpendicular to the direction of gravity, and that the ZX plane is a plane perpendicular to the direction of gravity.

[0022] The light source distribution element 100 and the headlamp module will be described in detail below. As shown in FIGS. 1 to 6, the headlamp module includes a light source distribution element 100 and a light distribution forming part 200. The headlamp device further comprises a light source 1 in addition to the headlamp module. The light source 1 emits light to illuminate the area ahead of the vehicle. The light source 1 is disposed on the negative side of the Y axis of the light source distribution element 100, and emits light in the positive direction of the Y axis. The optical axis of the light source 1 is an axis along the Y axis direction.

[0023] The light source 1 has a rectangular emission surface that emits light to the front. The light source 1 is either a tube light source such as an incandescent lamp, a halogen lamp, or a fluorescent lamp, or a semiconductor light source such as a light emitting diode (LED, hereinafter referred to as LED) or a laser diode (LD, hereinafter referred to as LD).

[0024] From the perspective of reducing the burden on the environment by reducing carbon dioxide (CO2) emissions and fuel consumption, it is preferable to use semiconductor light sources, which have higher luminous efficiency than halogen lamps, are directional, and allow for smaller and lighter optical systems. The headlamp device of the present disclosure uses an LED, which is one type of semiconductor light source.

[0025] In the first embodiment, the light source distribution element 100 and the light distribution formation section 200 are integrally formed from a transparent material, and the boundary surface between the components is not a physical boundary surface but a virtual surface. However, when the light source distribution element 100 is used alone, the exit surfaces 121a to 125a of the light source distribution element 100 are physically exposed surfaces, and when used as a headlamp module, the exit surfaces 121a to 125a of the light source distribution element 100 are coupled to the light distribution forming unit 200 when assembled with the light distribution forming unit 200.

[0026] In the first embodiment, the headlamp module is manufactured by injection molding and is made of a transparent material filled with a refractive material. The material from which the headlamp module is manufactured is preferably highly transparent from the viewpoint of light utilization efficiency, and is also preferably heat-resistant because the light source distribution element 100 is disposed immediately after the light source 1. For example, glass or a transparent resin such as silicone is suitable. Specifically, suitable transparent resins include acrylic resins (particularly PMMA: polymethyl methacrylate), polycarbonate (PC), and cycloolefin resins.

[0027] The light source distribution element 100 comprises an input section 110 and a collecting light guide section 120 . 7, incident section 110 is a collimator that has a conical shape and has lens 116 at the apex, and the bottom surface of the cone serves as the bonding surface for collecting light-guiding section 120. The bonding surface has a diameter of, for example, 20 mm. In the incident portion 110, light emitted from the light source 1 is incident on the lens 116, and the incident light is guided to the junction surface as parallel light, ideally as parallel light.

[0028] Of the light emitted from light source 1, light rays with small emission angles are incident on lens 116 and then directly guided to the conical bottom surface of incident section 110 (the joint surface of collective light-guiding section 120). On the other hand, of the light emitted from light source 1, light rays with large emission angles are incident on lens 116 and then reflected by reflecting surface 117 and guided to the conical bottom surface of incident section 110. The light rays directly guided from lens 116 and the light rays reflected and guided by reflecting surface 117 are guided to the joint surface of collective light-guiding section 120 as parallel light.

[0029] FIG. 8 shows the illuminance distribution at the joint surface of the light source distribution element 100 when an LED that emits light elongated in the X-axis direction is used as the light source 1. In the first embodiment, as shown in FIG. 8 , the bonding surfaces of the light-source distribution element 100 are divided into equal lengths, i.e., equal widths, in one direction in a plane perpendicular to the optical axis of the light source 1, i.e., along the Z-axis direction, and include a first bonding surface 111 located at the center, a second bonding surface 112 and a third bonding surface 113 located in this order from the center to one end side in the one direction, i.e., on the + side of the Z-axis, and a fourth bonding surface 114 and a fifth bonding surface 115 located in this order from the center to the other end side in the one direction, i.e., on the - side of the Z-axis. First bonding surface 111 to fifth bonding surface 115 are imaginary surfaces that indicate boundaries with collective light-guiding section 120 .

[0030] Collective light-guiding section 120 has a joint surface that joins with the joint surface of incident section 110. Collective light-guiding section 120 has five exit surfaces, first to fifth exit surfaces 121a to 125a, that are arranged in a plane parallel to the joint surface of incident section 110, i.e., the ZX plane, and without overlapping in the Z-axis direction and the X-axis direction, and guides light from the joint surface of incident section 110 to first to fifth exit surfaces 121a to 125a.

[0031] Along the X axis, fifth exit surface 125a, fourth exit surface 124a, first exit surface 121a, second exit surface 122a, and third exit surface 123a are arranged in this order from the other end side. Along the Z axis, fifth exit surface 125a, fourth exit surface 124a, first exit surface 121a, second exit surface 122a, and third exit surface 123a are arranged in this order from the other end side. First to fifth exit surfaces 121a to 125a are rectangular, and each has the same length W in the X-axis direction and the same length in the Z-axis direction. The lengths of the respective exit surfaces in the X-axis direction may be different.

[0032] Collective light-guiding section 120 includes first light-guiding section 121 to fifth light-guiding section 125 . Each of the first light guiding section 121 to the fifth light guiding section 125 has a pair of opposing surfaces that face each other parallel to the X-axis direction in the ZX plane, a plane perpendicular to the optical axis of the light source 1, i.e., the Y-axis, and is a columnar body with a rectangular ZX cross section. First light guiding section 121 has first emission surface 121a, and guides light from first bonding surface 111 of incident section 110 to first emission surface 121a.

[0033] First light guiding section 121 has a pair of opposing surfaces parallel to the Y axis, stands upright from first bonding surface 111 of incident section 110, and is formed integrally with incident section 110. The distance between the pair of opposing surfaces along the X axis direction is W. First light guiding section 121 has a rectangular parallelepiped shape that linearly connects first joint surface 111 of incident section 110 to first emission surface 121a. As shown as light beam L1 in FIGS. 9 and 10, first light guiding section 121 causes light from first bonding surface 111 of incident section 110 to travel straight along the Y axis to first emission surface 121a.

[0034] Second light guiding section 122 has second exit surface 122a, and guides light from second bonding surface 112 of incident section 110 to second exit surface 122a. A pair of opposing surfaces of second light guiding section 122 has a pair of reflecting surfaces, that is, first reflecting surface 122b located on the central side in the X-axis direction and second reflecting surface 122c located on one end side. In the first embodiment, the first reflecting surface 122b and the second reflecting surface 122c are the entire surfaces of a pair of opposing surfaces, respectively.

[0035] Second light guiding section 122 is formed integrally with incident section 110 such that first reflecting surface 122b and second reflecting surface 122c are each inclined at 45 degrees toward one end with respect to second bonding surface 112. In other words, second light guiding section 122 is formed integrally with incident section 110 such that first reflecting surface 122b and second reflecting surface 122c are each inclined at 45 degrees toward one end with respect to the optical axis of light source 1.

[0036] The distance between the first reflecting surface 122b and the second reflecting surface 122c along the X-axis direction is W. The second light-guiding section 122 has a columnar shape, with a distance W along the X-axis direction between a first reflecting surface 122b and a second reflecting surface 122c that connect the second bonding surface 112 of the incident section 110 to the second exit surface 122a in a straight line at an angle of 45 degrees toward one end with respect to the second bonding surface 112.

[0037] Note that 45 degrees does not mean the exact angle of 45 degrees, but refers to a range of 45 degrees ±α that takes into account ±α in design tolerances, etc. In the following explanation, 45 degrees also refers to a range of 45 degrees ±α. Furthermore, the tilt angle of the reflective surface does not need to be limited to 45 degrees. Since it is desirable for the reflective surface to be a total reflection surface, the ideal tilt angle is around 45 degrees. However, in the case of a mirror surface formed by metal vapor deposition or the like, the tilt angle can be freely designed. However, it is desirable for the reflective surface to function as a total reflection surface. This is because a total reflection surface has a higher reflectivity than a mirror surface and contributes to improving the light utilization efficiency. Furthermore, by eliminating the mirror vapor deposition process, the manufacturing process of the light source distribution element 100 can be simplified, which contributes to reducing the manufacturing cost of the light source distribution element 100.

[0038] 9 and 10, second light guiding unit 122 totally reflects the light from second bonding surface 112 of incident unit 110 by first reflecting surface 122b to second reflecting surface 122c, and then second reflecting surface 122c totally reflects the light to second exit surface 122a, thereby guiding the light to second exit surface 122a. Second light guiding unit 122 finally guides the light from second bonding surface 112 of incident unit 110 to second exit surface 122a as parallel light along the Y axis.

[0039] Third light guiding section 123 has third exit surface 123a, and guides light from third bonding surface 113 of incident section 110 to third exit surface 123a. A pair of opposing surfaces of third light guiding section 123 has a pair of reflecting surfaces, that is, third reflecting surface 123b located on the central side in the X-axis direction and fourth reflecting surface 123c located on one end side.

[0040] Third light guiding section 123 is formed integrally with incident section 110 such that third reflecting surface 123b and fourth reflecting surface 123c are each inclined at 45 degrees toward one end with respect to third bonding surface 113. In other words, third light guiding section 123 is formed integrally with incident section 110 such that third reflecting surface 123b and fourth reflecting surface 123c are each inclined at 45 degrees toward one end with respect to the optical axis of light source 1.

[0041] The distance between third reflecting surface 123b and fourth reflecting surface 123c along the X-axis direction is twice W, ie, 2W. Third light guiding section 123 has a length of 2W along the X-axis direction and is in the shape of a column inclined at 45 degrees toward one end with respect to third bonding surface 113. The fourth reflecting surface 123c of the third light guiding section 123 is located at a position away from the position of the second reflecting surface 122c of the second light guiding section 122 by the length W of the third exit surface 123a in the other direction toward one end in the other direction.

[0042] 9 and 10, third light guiding unit 123 totally reflects the light from third bonding surface 113 of incident unit 110 to fourth reflecting surface 123c, which then totally reflects the light to third exit surface 123a, thereby guiding the light to third exit surface 123a, as shown as light beam L3 in Fig. 9 and 10. Third light guiding unit 123 finally guides the light from third bonding surface 113 of incident unit 110 to third exit surface 123a as parallel light along the Y axis.

[0043] Third reflecting surface 123b of third light guiding section 123 is continuous with first reflecting surface 122b of second light guiding section 122 on one end side in the Z axis direction. Third light guiding section 123 is formed integrally with second light guiding section 122 from third joint surface 113 of incident section 110 to the position of first reflecting surface 122b of second light guiding section 122 to the position of second reflecting surface 122c.

[0044] The fourth reflecting surface 123c of the third light guiding section 123 is located at a position away from the position of the second reflecting surface 122c of the second light guiding section 122 by the length W of the third exit surface 123a in the X-axis direction toward one end in the X-axis direction. That is, the distance along the X-axis direction between the third reflecting surface 123b and the fourth reflecting surface 123c is twice the distance W along the X-axis direction between the first reflecting surface 122b and the second reflecting surface 122c in the second light-guiding section 122, i.e., 2W.

[0045] Third light guiding section 123 has a shape in which two second light guiding sections 122 are arranged in parallel in the X-axis direction. The portion from third reflecting surface 123 b of third light guiding portion 123 to the position of second reflecting surface 122 c of second light guiding portion 122 is formed integrally with second light guiding portion 122 .

[0046] The section from the position of the first reflecting surface 122b to the position of the second reflecting surface 122c of the second light guiding section 122 and the section from the position of the third reflecting surface 123b of the third light guiding section 123 to the position of the second reflecting surface 122c of the second light guiding section 122 form a common light guiding section in the Z-axis direction, with the shape of two second light guiding sections 122 arranged in parallel. From the position of the first reflecting surface 122b of the second light guiding section 122 to the position of the second reflecting surface 122c, the boundary surface between the second light guiding section 122 and the third light guiding section 123 is not a physical boundary surface, but a virtual surface.

[0047] Fourth light guiding section 124 has fourth exit surface 124a, and guides light from fourth bonding surface 114 of incident section 110 to fourth exit surface 124a. A pair of opposing surfaces of fourth light guiding section 124 has a pair of reflecting surfaces, that is, fifth reflecting surface 124b located on the central side in the X-axis direction and sixth reflecting surface 124c located on the other end side. In the first embodiment, the fifth reflecting surface 124b and the sixth reflecting surface 124c are the entire surfaces of a pair of opposing surfaces, respectively.

[0048] Fourth light guiding section 124 is formed integrally with incident section 110 such that fifth reflecting surface 124b and sixth reflecting surface 124c are each inclined at 45 degrees toward the other end with respect to fourth bonding surface 114. In other words, fourth light guiding section 124 is formed integrally with incident section 110 such that fifth reflecting surface 124b and sixth reflecting surface 124c are each inclined at 45 degrees toward one end with respect to the optical axis of light source 1.

[0049] The distance between the fifth reflecting surface 124b and the sixth reflecting surface 124c along the X-axis direction is W. The fourth light-guiding section 124 has a columnar shape that connects the fourth bonding surface 114 of the incident section 110 to the fourth exit surface 124a in a straight line at an angle of 45 degrees toward the other end with respect to the fourth bonding surface 114, and has a spacing of W along the X-axis direction between the fifth reflecting surface 124b and the sixth reflecting surface 124c.

[0050] 9 and 10, the fourth light guiding unit 124 totally reflects the light from the fourth bonding surface 114 of the incident unit 110 to the sixth reflecting surface 124c, which then totally reflects the light to the fourth exit surface 124a, and guides the light to the fourth exit surface 124a, as shown as light beam L4 in Fig. 9 and 10. The fourth light guiding unit 124 finally guides the light from the fourth bonding surface 114 of the incident unit 110 to the fourth exit surface 124a as parallel light along the Y axis. The shape of fourth light guiding section 124 is in a line symmetric relationship with the shape of second light guiding section 122 with respect to the Y axis.

[0051] Fifth light guiding section 125 has fifth exit surface 125a, and guides light from fifth bonding surface 115 of incident section 110 to fifth exit surface 125a. A pair of opposing surfaces of fifth light guiding section 125 has a pair of reflecting surfaces, that is, seventh reflecting surface 125b located on the central side in the X-axis direction and eighth reflecting surface 125c located on the other end side.

[0052] Fifth light guiding section 125 is formed integrally with incident section 110 such that seventh reflecting surface 125b and eighth reflecting surface 125c are each inclined at 45 degrees toward the other end with respect to fifth bonding surface 115. In other words, fifth light guiding section 125 is formed integrally with incident section 110 such that seventh reflecting surface 125b and eighth reflecting surface 125c are each inclined at 45 degrees toward one end with respect to the optical axis of light source 1.

[0053] The distance between seventh reflecting surface 125b and eighth reflecting surface 125c along the X-axis direction is twice W, ie, 2W. Fifth light guiding section 125 has a length of 2W along the X-axis direction and is in the shape of a column inclined at 45 degrees toward the other end with respect to fifth joint surface 115 . Eighth reflecting surface 125c of fifth light guiding section 125 is located at a position away from the position of sixth reflecting surface 124c of fourth light guiding section 124 by the length W of fifth exit surface 125a in the other direction toward the other end in the other direction.

[0054] 9 and 10, the fifth light guiding unit 125 totally reflects the light from the fifth bonding surface 115 of the incident unit 110 to the eighth reflecting surface 125c, which then totally reflects the light to the fifth exit surface 125a, and guides the light to the fifth exit surface 125a, as shown as light beam L5 in Fig. 9 and 10. The fifth light guiding unit 125 finally guides the light from the fifth bonding surface 115 of the incident unit 110 to the fifth exit surface 125a as parallel light along the Y axis.

[0055] Seventh reflecting surface 125b of fifth light guiding section 125 is continuous with fifth reflecting surface 124b of fourth light guiding section 124 on the other end side in the Z-axis direction. Fifth light guiding section 125 is formed integrally with fourth light guiding section 124 from fifth joint surface 115 of incident section 110 to the position of fifth reflecting surface 124b of fourth light guiding section 124 to the position of sixth reflecting surface 124c.

[0056] The eighth reflecting surface 125c of the fifth light guiding section 125 is located at a position away from the position of the sixth reflecting surface 124c of the fourth light guiding section 124 by the length W of the fifth exit surface 125a in the X-axis direction toward the other end in the X-axis direction. That is, the distance along the X-axis direction between the seventh reflecting surface 125b and the eighth reflecting surface 125c is twice the distance W along the X-axis direction between the fifth reflecting surface 124b and the sixth reflecting surface 124c in the fourth light-guiding section 124, i.e., 2W.

[0057] Fifth light guiding section 125 has a shape in which two fourth light guiding sections 124 are arranged in parallel in the X-axis direction. The portion from seventh reflecting surface 125b of fifth light guiding portion 125 to the position of sixth reflecting surface 124c of fourth light guiding portion 124 is formed integrally with fourth light guiding portion 124. The section from the position of the fifth reflecting surface 124b to the position of the sixth reflecting surface 124c of the fourth light guiding section 124 and the section from the position of the seventh reflecting surface 125b of the fifth light guiding section 125 to the position of the sixth reflecting surface 124c of the fourth light guiding section 124 form a common light guiding section in the Z-axis direction, with two fourth light guiding sections 124 arranged in parallel.

[0058] From the position of the fifth reflecting surface 124b of the fourth light guiding section 124 to the position of the sixth reflecting surface 124c, the boundary surface between the fourth light guiding section 124 and the fifth light guiding section 125 is not a physical boundary surface, but a virtual surface. The shape of fifth light guiding section 125 is in a line symmetric relationship with the shape of third light guiding section 123 with respect to the Y axis.

[0059] In the light source distribution element 100 configured in this manner, by providing three or more, preferably five, exit surfaces for the collective light guide section 120, it is possible to reduce the height to the exit surface of the collective light guide section 120 without reducing the light utilization efficiency of light from the light source 1, as will be explained below. The apparent size of a light source is defined by "Abbe's invariant," which is determined by the product of the divergence angle in a direction of the light source and the length of the side of the light source in that direction. In other words, if the height of the light source, i.e., the vertical length, is h0, the vertical divergence angle of the light from the light source is θ0, the vertical length of the exit surface, i.e., the length of the vertical side, is h1, and the vertical divergence angle of the light emitted from the exit surface is θ1, then the relationship is h0×sin θ0>h1×sin θ1.

[0060] Therefore, by dividing the light beam from light source 1 into multiple beams, the apparent height of the light source can be reduced. In embodiment 1, first light guiding section 121 to fifth light guiding section 125 divide the light from light source 1 collimated by incident section 110 into five light beams, so that the length of the side in the Z-axis direction of the exit surface of collective light guiding section 120 can be reduced, and the length of the side in the Z-axis direction of first exit surface 121a to fifth exit surface 125a can be reduced. When the light-source distribution element 100 according to the first embodiment is applied to a headlight module, the height of the projection surface can be reduced, and the module can be made smaller.

[0061] The light distribution forming section 200 totally reflects light in the Y-axis direction from the exit surface of the collective light guiding section 120 in the light source distribution element 100, that is, in embodiment 1, the first exit surface 121a to the fifth exit surface 125a, forward in the Z-axis direction, and guides the light to the projection surface, that is, in embodiment 1, the first projection surface 231a to the fifth projection surface 235a. The light distribution forming unit 200 includes a light collecting optical unit 210, a light collecting distribution unit 220, and a projection unit 230. The light distribution forming unit 200 is integrally formed from a transparent material.

[0062] The light collecting optical section 210 collects the light from the exit surface of the light collecting light guiding section 120 by total reflection downward and forward in the Z-axis direction. The light collecting optical section 210 is formed integrally with the light collecting light guiding section 120. The collective focusing optic 210 comprises a first focusing optic 211 to a fifth focusing optic 215 . The first focusing optical unit 211 to the fifth focusing optical unit 215 are arranged along the X-axis in the order of the fifth focusing optical unit 215, the fourth focusing optical unit 214, the first focusing optical unit 211, the second focusing optical unit 212, and the third focusing optical unit 213 from the other end side.

[0063] The first light-collecting optical unit 211 has a joint surface that joins with the first exit surface 121a of the first light-guiding unit 121, a reflecting surface that faces the joint surface, is inclined toward one end of the Z axis, i.e., forward, relative to the joint surface, and has a light-collecting function, a pair of parallel opposing surfaces along the X axis, and a front surface that is located on one end of the Z axis and serves as an exit port for light reflected by the reflecting surface. The length along the X-axis of the joint surface of the first focusing optical unit 211, the distance between a pair of opposing surfaces of the first focusing optical unit 211, and the length along the X-axis of the front surface of the first focusing optical unit 211 are W, which is the same as the length W of the first exit surface 121a in the X-axis direction.

[0064] In the first light collecting optical unit 211, the reflecting surface is a flat surface inclined forward at an angle of less than 45 degrees relative to the bonding surface, and may have a curved surface depending on the application. First light collecting optical unit 211 collects light from first emission surface 121a of first light guiding unit 121 by reflecting the light downward and forward in the Z-axis direction using a reflecting surface. In the first embodiment, the joint surface of first light collecting optical unit 211 and first emission surface 121a of first light guiding unit 121 are not physically joined surfaces but are virtual surfaces.

[0065] The second light-collecting optical unit 212 has a joint surface that joins with the second emission surface 122a of the second light-guiding unit 122, a reflecting surface that faces the joint surface, is inclined toward one end of the Z axis, i.e., forward, relative to the joint surface, and has a light-collecting function, a pair of parallel opposing surfaces along the X axis, and a front surface that is located on one end of the Z axis and serves as an exit for light reflected by the reflecting surface. The length along the X-axis of the joint surface of the second focusing optical unit 212, the distance between the pair of opposing surfaces of the second focusing optical unit 212, and the length along the X-axis of the front surface of the second focusing optical unit 212 are W, which is the same as the length W of the second exit surface 122a in the X-axis direction.

[0066] In the second light collecting optical unit 212, the reflecting surface is a flat surface inclined forward at an angle of less than 45 degrees relative to the bonding surface, and may have a curved surface depending on the application. The second light-collecting optical unit 212 collects light from the second light-emitting surface 122a of the second light-guiding unit 122 by reflecting the light downward and forward in the Z-axis direction using a reflecting surface. In the first embodiment, the joint surface of second light collecting optical unit 212 and second emission surface 122a of second light guiding unit 122 are not physically joined surfaces but are virtual surfaces.

[0067] The third light-collecting optical unit 213 has a joint surface that joins with the third exit surface 123a of the third light-guiding unit 123, a reflecting surface that faces the joint surface and is inclined downward toward one end of the Z axis, i.e., forward, relative to the joint surface, and has a light-collecting function, a pair of parallel opposing surfaces along the X axis, and a front surface that is located on one end of the Z axis and serves as an exit port for light reflected by the reflecting surface. The length along the X-axis of the joint surface of the third focusing optical unit 213, the distance between a pair of opposing surfaces of the third focusing optical unit 213, and the length along the X-axis of the front surface of the third focusing optical unit 213 are W, which is the same as the length W of the third exit surface 123a in the X-axis direction.

[0068] In the third light collecting optical unit 213, the reflecting surface is a flat surface inclined forward at an angle of less than 45 degrees relative to the bonding surface, and may have a curved surface depending on the application. The third light-collecting optical unit 213 reflects the light from the third emission surface 123a of the third light-guiding unit 123 downward and forward in the Z-axis direction using a reflecting surface, thereby collecting the light. In the first embodiment, the joint surface of third light collecting optical unit 213 and third emission surface 123a of third light guiding unit 123 are not physically joined surfaces but are virtual surfaces.

[0069] The fourth light-collecting optical unit 214 has a joint surface that joins with the fourth exit surface 124a of the fourth light-guiding unit 124, a reflecting surface that faces the joint surface and is inclined downward toward one end of the Z axis, i.e., forward, relative to the joint surface, and has a light-collecting function, a pair of parallel opposing surfaces along the X axis, and a front surface located on one end of the Z axis that serves as an exit for light reflected by the reflecting surface. The length along the X-axis of the joint surface of the fourth focusing optical unit 214, the distance between a pair of opposing surfaces of the fourth focusing optical unit 214, and the length along the X-axis of the front surface of the fourth focusing optical unit 214 are W, which is the same as the length W of the fourth exit surface 124a in the X-axis direction.

[0070] In the fourth light collecting optical section 214, the reflecting surface is a flat surface inclined forward at less than 45 degrees relative to the bonding surface, and may have a curved surface depending on the application. The fourth light-collecting optical unit 214 reflects the light from the fourth emission surface 124a of the fourth light-guiding unit 124 downward and forward in the Z-axis direction using a reflecting surface, thereby collecting the light. In the first embodiment, the bonding surface of the fourth light collecting optical unit 214 and the fourth emission surface 124a of the fourth light guiding unit 124 are not physically bonded surfaces but are virtual surfaces.

[0071] The fifth light-collecting optical unit 215 has a joint surface that joins with the fifth exit surface 125a of the fifth light-guiding unit 125, a reflecting surface that faces the joint surface and is inclined toward one end of the Z axis, i.e., forward, relative to the joint surface, and has a light-collecting function, a pair of opposing surfaces along the X axis, and a front surface that is located on one end of the Z axis and serves as an exit for light reflected by the reflecting surface. The length along the X-axis of the joint surface of the fifth focusing optical unit 215, the distance between a pair of opposing surfaces of the fifth focusing optical unit 215, and the length along the X-axis of the front surface of the fifth focusing optical unit 215 are W, which is the same as the length W of the fifth exit surface 125a in the X-axis direction.

[0072] In the fifth light collecting optical section 215, the reflecting surface is a flat surface inclined forward and downward at an angle of less than 45 degrees relative to the cemented surface, and may have a curved surface depending on the application. Fifth light-collecting optical unit 215 reflects light from fifth emission surface 125a of fifth light-guiding unit 125 downward and forward in the Z-axis direction using a reflecting surface to collect the light. In the first embodiment, the joint surface of fifth light collecting optical section 215 and fifth emission surface 125a of fifth light guiding section 125 are not physically joined surfaces but are virtual surfaces.

[0073] By making the reflecting surfaces of each of the first focusing optical unit 211 to the fifth focusing optical unit 215 reflecting surfaces having a focusing function, it is possible to easily form the complex light distribution required for a headlamp device.

[0074] Collective light distribution section 220 guides the multiple light beams reflected and collected by collective light collection optical section 210 to multiple projection surfaces, in the first embodiment, first projection surface 231a to fifth projection surface 235a. The light collecting and distributing section 220 is formed integrally with the light collecting and concentrating optical section 210 . The collective light distribution section 220 includes a first light distribution section 221 to a fifth light distribution section 225 . The first to fifth light distribution sections 221 to 225 are arranged along the X axis in the following order from the other end: fifth light distribution section 225, fourth light distribution section 224, first light distribution section 221, second light distribution section 222, and third light distribution section 223. Adjacent light distribution sections are not physically joined together.

[0075] First light distribution unit 221 guides light resulting from a luminous flux reflected and collected from the front surface of first light collecting optical unit 211 to projection unit 230. The joint surface between first light distribution unit 221 and the front surface of first light collecting optical unit 211 is not a physically joined surface but a virtual surface. The width of first light distribution section 221 along the X axis is W, which is the same as the length W of first emission surface 121a in the X axis direction.

[0076] The second light distribution unit 222 guides the light resulting from the luminous flux reflected and collected from the front surface of the second light collecting optical unit 212 to the projection unit 230. The joint surface between the second light distribution unit 222 and the front surface of the second light collecting optical unit 212 is not a physically joined surface, but a virtual surface. The width of second light distribution section 222 along the X axis is W, which is the same as the length W of second emission surface 122a in the X axis direction.

[0077] Third light distribution unit 223 guides light resulting from the luminous flux reflected and collected from the front surface of third light collecting optical unit 213 to projection unit 230. The joint surface between third light distribution unit 223 and the front surface of third light collecting optical unit 213 is not a physically joined surface but a virtual surface. The width of third light distribution section 223 along the X axis is W, which is the same as the length W of third emission surface 123a in the X axis direction.

[0078] The fourth light distribution unit 224 guides the light of the luminous flux reflected and collected from the front surface of the fourth light collecting optical unit 214 to the projection unit 230. The joint surface between the fourth light distribution unit 224 and the front surface of the fourth light collecting optical unit 214 is not a physically joined surface, but a virtual surface. The width of fourth light distribution section 224 along the X axis is W, which is the same as the length W of fourth emission surface 124a in the X axis direction.

[0079] Fifth light distribution unit 225 guides light resulting from the luminous flux reflected and collected from the front surface of fifth light collecting optical unit 215 to projection unit 230. The joint surface between fifth light distribution unit 225 and the front surface of fifth light collecting optical unit 215 is not a physically joined surface but a virtual surface. The width of fifth light distribution section 225 along the X axis is W, which is the same as the length W of fifth emission surface 125a in the X axis direction.

[0080] Projection unit 230 has a plurality of projection surfaces, first to fifth projection surfaces 231a to 235a in the first embodiment, and projects light guided as a luminous flux by collective light distribution unit 220 from the plurality of projection surfaces. Projection unit 230 is formed integrally with collective light distribution unit 220. The projection unit 230 includes a first projection lens 231 to a fifth projection lens 235 . The first to fifth projection lenses 231 to 235 are arranged along the X-axis in the order of the fifth projection lens 235, the fourth projection lens 234, the first projection lens 231, the second projection surface 232a, and the third projection surface 233a from the other end side.

[0081] The first projection lens 231 has a first projection surface 231a, and projects the light guided as a luminous flux by the first light distribution section 221 forward from the first projection surface 231a as low beam irradiation light. The first projection lens 231 is a convex lens having a first projection surface 231a with a convex shape on its surface. The joint surface between the first projection lens 231 and the first light distribution section 221 is not a physically joined surface, but a virtual surface.

[0082] The second projection lens 232 has a second projection surface 232a, and projects the light guided as a luminous flux by the second light distribution section 222 forward from the second projection surface 232a as low beam irradiation light. The second projection lens 232 is a convex lens having a second projection surface 232a with a convex shape on its surface. The joint surface between the second projection lens 232 and the second light distribution section 222 is not a physically joined surface, but a virtual surface.

[0083] The third projection lens 233 has a third projection surface 233a, and projects the light guided as a luminous flux by the third light distribution section 223 forward from the third projection surface 233a as low beam irradiation light. The third projection lens 233 is a convex lens having a third projection surface 233a with a convex shape on its surface. The joint surface between the third projection lens 233 and the third light distribution section 223 is not a physically joined surface, but a virtual surface.

[0084] The fourth projection lens 234 has a fourth projection surface 234a, and projects the light guided as a luminous flux by the fourth light distribution section 224 forward from the fourth projection surface 234a as low beam irradiation light. The fourth projection lens 234 is a convex lens having a fourth projection surface 234a with a convex shape on its surface. The joint surface between the fourth projection lens 234 and the fourth light distribution section 224 is not a physically joined surface, but a virtual surface.

[0085] The fifth projection lens 235 has a fifth projection surface 235a, and projects the light guided as a luminous flux by the fifth light distribution section 225 forward from the fifth projection surface 235a as low beam irradiation light. The fifth projection lens 235 is a convex lens having a fifth projection surface 235a with a convex shape on its surface. The joint surface between the fifth projection lens 235 and the fifth light distribution section 225 is not a physically joined surface, but a virtual surface. Each of the first projection lens 231 to the fifth projection lens 235 may be a concave lens having a concave projection surface on its surface.

[0086] Next, the path of light from the bonding surface of the incident portion 110 will be described with reference to FIGS. The light guided from the first bonding surface 111 of the incident section 110 to the first light guiding section 121 travels straight along the Y axis to the first exit surface 121a, as shown as light beam L1 in Figures 9 and 10, and the light that reaches the reflecting surface of the first focusing optical section 211 is totally reflected and focused forward in the Z axis direction by the reflecting surface of the first focusing optical section 211, and propagates within the first light distribution section 221 to reach the first projection lens 231. The light that reaches the first projection lens 231 is focused by the first projection lens 231 and emitted forward as low beam irradiation light.

[0087] The light guided from the second bonding surface 112 of the incident section 110 to the second light guiding section 122 travels straight along the Y axis to the first reflecting surface 122b, as shown as light beam L2 in Figures 9 and 10, and the light that reaches the first reflecting surface 122b is totally reflected by the first reflecting surface 122b at a right angle to one end side in the X axis direction. The light that is totally reflected at a right angle by the first reflecting surface 122b and reaches the second reflecting surface 122c is totally reflected at a right angle by the second reflecting surface 122c, is guided along the Y axis to the second exit surface 122a, and reaches the reflecting surface of the second focusing optical unit 212.

[0088] The light that reaches the reflective surface of the second focusing optical unit 212 is totally reflected forward in the Z-axis direction by the reflective surface of the second focusing optical unit 212 and focused, and then propagates within the second light distribution unit 222 to reach the second projection lens 232. The light that reaches the second projection lens 232 is focused by the second projection lens 232 and emitted forward as low beam irradiation light.

[0089] The light guided from the third bonding surface 113 of the incident portion 110 to the third light guiding portion 123 travels straight along the Y axis to the third reflecting surface 123b, as shown as light beam L3 in Figures 9 and 10, and the light that reaches the third reflecting surface 123b is totally reflected by the third reflecting surface 123b at a right angle to one end side in the X axis direction. The light that is totally reflected at a right angle by the third reflecting surface 123b and reaches the fourth reflecting surface 123c is totally reflected at a right angle by the fourth reflecting surface 123c, is guided along the Y axis to the third exit surface 123a, and reaches the reflecting surface of the third focusing optical unit 213.

[0090] The light that reaches the reflecting surface of the third focusing optical unit 213 is totally reflected forward in the Z-axis direction by the reflecting surface of the third focusing optical unit 213 and focused, and then propagates within the third light distribution unit 223 to reach the third projection lens 233. The light that reaches the third projection lens 233 is focused by the third projection lens 233 and emitted forward as low beam irradiation light.

[0091] The light guided from the fourth bonding surface 114 of the incident section 110 to the fourth light-guiding section 124 travels straight along the Y-axis to the fifth reflecting surface 124b, as shown as light beam L4 in Figures 9 and 10, and the light that reaches the fifth reflecting surface 124b is totally reflected by the fifth reflecting surface 124b at a right angle to the other end side in the X-axis direction. The light that is totally reflected at a right angle by the fifth reflecting surface 124b and reaches the sixth reflecting surface 124c is totally reflected at a right angle by the sixth reflecting surface 124c, is guided along the Y axis to the fourth exit surface 124a, and reaches the reflecting surface of the fourth focusing optical unit 214.

[0092] The light that reaches the reflective surface of the fourth focusing optical unit 214 is totally reflected forward in the Z-axis direction by the reflective surface of the fourth focusing optical unit 214 and focused, then propagates within the fourth light distribution unit 224 and reaches the fourth projection lens 234. The light that reaches the fourth projection lens 234 is focused by the fourth projection lens 234 and emitted forward as low beam irradiation light.

[0093] The light guided from the fifth bonding surface 115 of the incident section 110 to the fifth light-guiding section 125 travels straight along the Y-axis to the seventh reflecting surface 125b, as shown as light beam L5 in Figures 9 and 10, and the light that reaches the seventh reflecting surface 125b is totally reflected by the seventh reflecting surface 125b at a right angle to the other end side in the X-axis direction. The light that is totally reflected at a right angle by the seventh reflecting surface 125b and reaches the eighth reflecting surface 125c is totally reflected at a right angle by the eighth reflecting surface 125c, is guided along the Y axis to the fifth exit surface 125a, and reaches the reflecting surface of the fifth focusing optical unit 215.

[0094] The light that reaches the reflecting surface of the fifth focusing optical unit 215 is totally reflected forward in the Z-axis direction by the reflecting surface of the fifth focusing optical unit 215 and focused, and then propagates within the fifth light distribution unit 225 to reach the fifth projection lens 235. The light that reaches the fifth projection lens 235 is focused by the fifth projection lens 235 and emitted forward as low beam irradiation light.

[0095] In the light-source distribution element 100 according to the first embodiment configured as described above, the incident portion 110 has three or more bonding surfaces 111 to 115, and has exit surfaces 121a to 125a corresponding to the bonding surfaces 111 to 115 of the incident portion 110, and three or more light guide portions 121 to 125 are provided, each of which guides light from the corresponding bonding surface 111 to 115 to the corresponding exit surface 121a to 125a. Of the light guide portions 121 to 125, the pair of opposing surfaces of the light guide portions 122 and 123 whose exit surfaces 122a and 123a are located on one end side from the center in the X-axis direction are located on one end side. The light guides 124, 125 have a pair of reflecting surfaces 122b, 122c, 123b, 123c tilted with respect to the optical axis of the light source 1 on the opposite side, and among the plurality of light guides 121 to 125, the pair of opposing surfaces of the light guides 124, 125 whose exit surfaces 124a, 125a are located on the other end side of the center in the X-axis direction have a pair of reflecting surfaces 124b, 124c, 125b, 125c tilted with respect to the optical axis of the light source 1 on the other end side, and three or more plurality of light guides 121 to 125 are used to split the incident light beam that has entered the entrance unit 110 into a plurality of beams in the Z-axis direction, and the split light beams are emitted from the exit surfaces 121a to 125a.

[0096] In this way, by dividing and branching the incident light beam incident from the incident section 110 into three or more beams in one direction by three or more light-guiding sections 121-125, the apparent size of the light source in the division direction relative to the three or more bonding surfaces 111-115, i.e., in one direction, can be made smaller. Therefore, the light utilization efficiency of the light source distribution element 100 does not deteriorate, and the structure is simplified and the light source distribution element 100 can be made thinner in one direction without reducing the light utilization efficiency.

[0097] Furthermore, in the light-source distribution element 100 according to the first embodiment, the joint surface of the incident portion 110 is divided into first joint surface 111 to fifth joint surface 115 at equal lengths in one direction, and first light guiding portion 121 to fifth light guiding portion 125 have first exit surface 121a to fifth exit surface 125a corresponding to the first joint surface 111 to fifth joint surface and arranged without overlapping in one direction and the other direction, and a second light guiding portion 125 has a pair of reflecting surfaces inclined at 45 degrees toward one end side with respect to the corresponding joint surface of the incident portion 110 at the center, at one end side of the first light guiding portion 121. The light source distribution element 100 has a light section 122 and a third light guiding section 123, and a fourth light guiding section 124 and a fifth light guiding section 125 at the other end thereof, each having a pair of reflecting surfaces inclined at 45 degrees toward the other end thereof relative to the corresponding joint surface of the incident section 110. The third light guiding section 123 has a light guiding section that is continuous in one direction from the third joint surface 113 to the second light guiding section 122, and the fifth light guiding section 125 has a light guiding section that is continuous in one direction from the third joint surface 113 to the fourth light guiding section 124. This makes it possible to obtain a thin light source distribution element 100 with a simple structure and without reducing light utilization efficiency.

[0098] The headlight module of embodiment 1 applies the above-mentioned light source distribution element 100, has a plurality of projection surfaces positioned along the other direction, and is equipped with a light distribution forming section 200 that reflects light from the exit surfaces 121a to 125a of the plurality of light-guiding sections 121 to 125 in the light source distribution element 100 toward one end in one direction and guides it to the plurality of projection surfaces 231a to 235a.Therefore, the length in the direction perpendicular to the plane formed by the one direction and the other direction of the plurality of projection surfaces 231a to 235a, i.e., the height direction, can be reduced, and the structure can be simplified and the module can be made thinner in the height direction without reducing light utilization efficiency.

[0099] The headlamp module according to the first embodiment is resistant to variations in placement accuracy for a plurality of light beams and is easy to handle, because the light-source distribution element 100 and the light distribution formation section 200 are integrally formed from a transparent material. Furthermore, by forming them integrally, loss due to Fresnel reflection can be reduced. The headlight module according to the first embodiment may be used as one element of a low-beam automobile headlight device, and a plurality of headlight modules according to the first embodiment may be arranged in parallel in other directions, that is, in the left-right direction of the automobile.

[0100] Embodiment 2 A light-source distribution element 100 and a headlamp module according to the second embodiment will be described with reference to FIGS. The headlight module according to the second embodiment has a configuration in which the joining surfaces of the incident portion 110 are five first joining surfaces 111 to fifth joining surfaces 115, the collective light-guiding portion 120 is five first light-guiding portions 121 to fifth light-guiding portions 125, the collective light-collecting optical portion 210 is five first light-collecting optical portions 211 to fifth light-collecting optical portions 215, the collective light-distributing portion 200 is five first light-distributing portions 221 to fifth light-distributing portions 225, and the projection portion 230 is five first projection lenses 231 to fifth projection lenses 235. The differences are that the surfaces are three: a first bonding surface 111, a second bonding surface 112, and a fourth bonding surface 114; the collective light-guiding section 120 is three: a first light-guiding section 121, a second light-guiding section 122, and a fourth light-guiding section 124; the collective light-collecting optical section 210 is three: a first light-collecting optical section 211, a second light-collecting optical section 212, and a fourth light-collecting optical section 214; the collective light-distributing section 200 is three: a first light-distributing section 221, a second light-distributing section 222, and a fourth light-distributing section 224; and the projection section 230 is three: a first projection lens 231, a second projection lens 232, and a fourth projection lens 234. 11 to 18, the same reference numerals as those in FIGS. 1 to 10 indicate the same or corresponding parts.

[0101] The following description will focus on the differences from the headlamp module according to the first embodiment. The bonding surfaces of the incident portion 110 are divided along the Z-axis direction at equal lengths, i.e., equal widths, and have a first bonding surface 111 located at the center, a second bonding surface 112 located at one end side in one direction from the center, and a fourth bonding surface 114 located at the other end side in one direction from the center.

[0102] The collective light-guiding section 120 has a joint surface that joins with the joint surface of the light-source distribution element 100, and has three exit surfaces, namely, a first exit surface 121a, a second exit surface 122a, and a fourth exit surface 124a, that are arranged without overlapping in the Z-axis direction and the X-axis direction, and guides light from the joint surface of the light-source distribution element 100 to the first exit surface 121a, the second exit surface 122a, and the fourth exit surface 124a. The length W in the X-axis direction of each of first exit surface 121a, second exit surface 122a, and fourth exit surface 124a is the same as the length W in the X-axis direction of each of first exit surface 121a, second exit surface 122a, and fourth exit surface 124a in embodiment 1.

[0103] Collective light-guiding section 120 includes first light-guiding section 121, second light-guiding section 122, and fourth light-guiding section 124, which differ only in length along the Z-axis direction from first light-guiding section 121, second light-guiding section 122, and fourth light-guiding section 124 in embodiment 1, but are otherwise the same.

[0104] In this light source distribution element 100 in which the collective light guide section 120 has three exit surfaces, by dividing the light beam from the light source 1 into three, the apparent height of the light source can be reduced, the length of the side in the Z-axis direction of the exit surface of the collective light guide section 120 can be reduced, and the length of the side in the Z-axis direction of each of the first exit surface 121a, the second exit surface 122a, and the fourth exit surface 124a can be reduced. When the light-source distribution element 100 according to the first embodiment is applied to a headlight module, the height of the projection surface can be reduced, and the module can be made smaller.

[0105] The light distribution forming unit 200 guides light from the first exit surface 121a, the second exit surface 122a, and the fourth exit surface 124a of the light source distribution element 100 to the first projection surface 231a, the second projection surface 232a, and the fourth projection surface 234a, respectively, and projects the light from the first projection surface 231a, the second projection surface 232a, and the fourth projection surface 234a.

[0106] The first focusing optical unit 211, the second focusing optical unit 212, and the fourth focusing optical unit 214 of the collective focusing optical unit 210 in the light distribution forming unit 200 are the same as the first focusing optical unit 211, the second focusing optical unit 212, and the fourth focusing optical unit 214 in embodiment 1, respectively. The first light distribution section 221, the second light distribution section 222, and the fourth light distribution section 224 of the collective light distribution section 220 in the light distribution forming section 200 are the same as the first light distribution section 221, the second light distribution section 222, and the fourth light distribution section 224 in the first embodiment, respectively. The first projection lens 231, the second projection lens 232, and the fourth projection lens 234 of the projection section 230 in the light distribution forming section 200 are the same as the first projection lens 231, the second projection lens 232, and the fourth projection lens 234, respectively, in embodiment 1.

[0107] Next, the path of light from the bonding surface of the incident portion 110 will be described with reference to FIGS. The light guided from the first bonding surface 111 of the incident section 110 to the first light guiding section 121 travels straight along the Y axis to the first exit surface 121a, as shown as light beam L1 in Figures 17 and 18, and the light that reaches the reflective surface of the first focusing optical section 211 is totally reflected and focused forward and downward in the Z axis direction by the reflective surface of the first focusing optical section 211, and propagates within the first light distribution section 221 to reach the first projection lens 231. The light that reaches the first projection lens 231 is focused by the first projection lens 231 and emitted forward as low beam irradiation light.

[0108] The light guided from the second bonding surface 112 of the incident section 110 to the second light guiding section 122 travels straight along the Y axis to the first reflecting surface 122b, as shown as light beam L2 in Figures 17 and 18, and the light that reaches the first reflecting surface 122b is totally reflected by the first reflecting surface 122b at a right angle to one end side in the X axis direction. The light that is totally reflected at a right angle by the first reflecting surface 122b and reaches the second reflecting surface 122c is totally reflected at a right angle by the second reflecting surface 122c, is guided along the Y axis to the second exit surface 122a, and reaches the reflecting surface of the second focusing optical unit 212.

[0109] The light that reaches the reflective surface of the second focusing optical unit 212 is totally reflected and focused forward and downward in the Z-axis direction by the reflective surface of the second focusing optical unit 212, and then propagates within the second light distribution unit 222 to reach the second projection lens 232. The light that reaches the second projection lens 232 is focused by the second projection lens 232 and emitted forward as low beam irradiation light.

[0110] The light guided from the fourth bonding surface 114 of the incident section 110 to the fourth light-guiding section 124 travels straight along the Y-axis to the fifth reflecting surface 124b, as shown as light beam L4 in Figures 17 and 18, and the light that reaches the fifth reflecting surface 124b is totally reflected by the fifth reflecting surface 124b at a right angle to the other end side in the X-axis direction. The light that is totally reflected at a right angle by the fifth reflecting surface 124b and reaches the sixth reflecting surface 124c is totally reflected at a right angle by the sixth reflecting surface 124c, is guided along the Y axis to the fourth exit surface 124a, and reaches the reflecting surface of the fourth focusing optical unit 214.

[0111] The light that reaches the reflective surface of the fourth focusing optical unit 214 is totally reflected and focused forward and downward in the Z-axis direction by the reflective surface of the fourth focusing optical unit 214, and then propagates within the fourth light distribution unit 224 to reach the fourth projection lens 234. The light that reaches the fourth projection lens 234 is focused by the fourth projection lens 234 and emitted forward as low beam irradiation light.

[0112] The light-source distribution element 100 according to the second embodiment configured as described above splits and branches the incident light beam from the incident section 110 into three in one direction using the first light-guiding section 121, the second light-guiding section 122, and the fourth light-guiding section 124, thereby making it possible to reduce the apparent size of the light source in the splitting direction, i.e., in one direction, relative to the three light-emitting reference surfaces, i.e., the first bonding surface 111, the second bonding surface 112, and the fourth bonding surface 114. Therefore, the light utilization efficiency is not deteriorated, and the structure can be simplified and made thin.

[0113] Furthermore, the headlight module according to the second embodiment applies the above-described light source distribution element 100, and uses the light distribution forming unit 200 to project light from the first projection lens 231, the second projection lens 232, and the fourth projection lens 234, which are positioned along the other direction. This makes it possible to reduce the length in the direction perpendicular to the plane formed by the one direction and the other direction of the first projection lens 231, the second projection lens 232, and the fourth projection lens 234, i.e., the height direction, and thereby simplify the structure and make it possible to reduce the thickness in the height direction without reducing the light utilization efficiency.

[0114] In the first embodiment, the joint surface of the incident portion 110 is divided into five, and light from the five divided joint surfaces 111 to 115 of the incident portion 110 is guided to the five exit surfaces 121 a to 125 a of the light-source distribution element 100, and the light from the five exit surfaces 121 a to 125 a of the light-source distribution element 100 is propagated to the light distribution formation portion 200 and projected from the five projection surfaces 231 a to 235 a. In the second embodiment, the joint surface of the incident portion 110 is divided into three, and light from the three divided joint surfaces 111, 112 of the incident portion 110 is guided to the five exit surfaces 121 a to 125 a of the light-source distribution element 100. , 114 is guided to three exit surfaces 121a, 122a, 124a of the light source distribution element 100, and the light from the three exit surfaces 121a, 122a, 124a of the light source distribution element 100 is propagated to the light distribution forming unit 200 and projected from three projection surfaces 231a, 232a, 234a. However, the joining surface of the incident portion 110 may be divided into four or seven, and the light source distribution element 100 and the light distribution forming unit 200 may be configured to match the number of divisions of the joining surface of the incident portion 110, as in the first embodiment.

[0115] As a headlight module, a preferred configuration is one in which the joint surface of incident portion 110 is divided into an odd number of portions equal to or greater than three, a first light-guiding portion is placed on the joint surface located in the center, and the remaining light-guiding portions are placed in half in the Z-axis direction, sandwiching the first light-guiding portion therebetween, with half of the light-guiding portions placed on one end side of the Z-axis direction tilted toward one end side of the X-axis direction, and half of the light-guiding portions placed on the other end side of the Z-axis direction tilted toward the other end side of the X-axis direction. In this case, the light beam from lens 116 can be concentrated on the cemented surface located at the center of incident portion 110, making it easier to form a light distribution from the projection surface.

[0116] Embodiment 3 A light-source distribution element 100 and a headlamp module according to the third embodiment will be described with reference to FIGS. 19 to 26. FIG. The headlight module according to embodiment 3 differs from the headlight module according to embodiment 1 in that, while the lengths in the X-axis direction of first exit surface 121a to fifth exit surface 125a are all W, the length in the X-axis direction of first exit surface 121a is W, the lengths in the X-axis direction of second exit surface 122a and fourth exit surface 124a are W1 which is shorter than W, and the lengths in the X-axis direction of third exit surface 123a and fifth exit surface 125a are W2 which is shorter than W1.

[0117] Due to this difference, the distance between the pair of reflecting surfaces in the second light guiding section 122 and the fourth light guiding section 124, the lengths in the X-axis direction of the second concentrating optical section 212 and the fourth concentrating optical section 214, the lengths in the X-axis direction of the second light distribution section 222 and the fourth light distribution section 224, and the lengths in the X-axis direction of the second projection lens 232 and the fourth projection lens 234 are W1, and the distance between the pair of reflecting surfaces in the third light guiding section 123 and the fifth light guiding section 125, the lengths in the X-axis direction of the third concentrating optical section 213 and the fifth light distribution section 215, the lengths in the X-axis direction of the third light distribution section 223 and the fifth light distribution section 225, and the lengths in the X-axis direction of the third projection lens 233 and the fifth projection lens 235 are W2. All other points are the same. The relationship between W, W1, and W2 is W>W1>W2.

[0118] However, the lengths in the X-axis direction of the second emission surface 122a, the second light guiding unit 122, the second concentrating optical unit 212, the second light distribution unit 222, and the second projection lens 232 may be different from the lengths in the X-axis direction of the fourth emission surface 124a, the fourth light guiding unit 124, the fourth concentrating optical unit 214, the fourth light distribution unit 224, and the fourth projection lens 234. Similarly, the lengths in the X-axis direction of the third emission surface 123a, the third light guiding unit 123, the third concentrating optical unit 213, the third light distribution unit 223, and the third projection lens 233 may be different from the lengths in the X-axis direction of the fifth emission surface 125a, the fifth light guiding unit 125, the fifth concentrating optical unit 215, the fifth light distribution unit 225, and the fifth projection lens 235. 19 to 26, the same reference numerals as those in FIGS. 1 to 10 indicate the same or corresponding parts.

[0119] The following description will focus on the differences from the headlamp module according to the first embodiment. First light guiding section 121 is the same as first light guiding section 121 in the first embodiment. The opposing surface at one end in the X-axis direction of the pair of opposing surfaces in the second light-guiding section 122 has a second rising surface 122d that is perpendicular to the second bonding surface 112 from the bottom surface that contacts the second bonding surface 112 of the incident section 110, and a second reflecting surface 122c that is inclined 45 degrees toward one end with respect to the second bonding surface 112 from the upper side of the second rising surface 122d to the second exit surface 122a. The distance between first reflecting surface 122b and second reflecting surface 122c along the X-axis direction is W1, which is the same as the distance W1 between second emitting surfaces 122a along the X-axis direction.

[0120] The length from the bottom to the top of second rising surface 122d corresponds to the length required to obtain an offset (W-W1) relative to length W1 of second exit surface 122a in the X-axis direction. The amount of light totally reflected by the first reflecting surface 122b and totally reflected by the second reflecting surface 122c is comparable to that in the case where the second rising surface 122d is not provided, because there is no light from the second bonding surface 112 of the incident section 110 at both ends of the bonding surface of the second light-guiding section 122 that contacts the second bonding surface 112 of the incident section 110.

[0121] The opposing surface at one end in the X-axis direction of the pair of opposing surfaces in the third light-guiding section 123 has a fourth rising surface 123d that is perpendicular to the third bonding surface 113 from the bottom surface that contacts the third bonding surface 113 of the incident section 110, and a fourth reflecting surface 123c that is inclined 45 degrees toward one end with respect to the third bonding surface 113 from the upper side of the fourth rising surface 123d to the third exit surface 123a. The distance between the third reflecting surface 123b and the fourth reflecting surface 123c along the X-axis direction is (W1+W2).

[0122] The spacing W2 along the X-axis direction of the third exit surface 123a is the spacing (W1+W2) along the X-axis direction between the third reflecting surface 123b and the fourth reflecting surface 123c minus the spacing W1 along the X-axis direction between the first reflecting surface 122b and the second reflecting surface 122c in the second light-guiding section 122. The distance (W1+W2) along the X-axis direction between the third reflecting surface 123b and the fourth reflecting surface 123c of the third light guiding section 123 is shorter than 2W1, which is twice the distance W1 along the X-axis direction between the first reflecting surface 122b and the second reflecting surface 122c of the second light guiding section 122.

[0123] The length from the bottom to the top of the fourth rising surface 123d corresponds to the offset amount (W-W2) relative to the length W2 of the third exit surface 123a in the X-axis direction, in other words, the length required to obtain (2W-(W1+W2)). The amount of light totally reflected by the third reflecting surface 123b and totally reflected by the fourth reflecting surface 123c is comparable to that in the case where the fourth rising surface 123d is not provided, because there is no light from the third bonding surface 113 of the incident section 110 at both ends of the bonding surface of the third light-guiding section 123 that contacts the third bonding surface 113 of the incident section 110.

[0124] The opposing surface on the other end side in the X-axis direction of the pair of opposing surfaces in the fourth light-guiding section 124 has a sixth rising surface 124d that is perpendicular to the fourth bonding surface 114 from the bottom surface that contacts the fourth bonding surface 114 of the incident section 110, and has a sixth reflecting surface 124c that is inclined at 45 degrees toward the other end side with respect to the fourth bonding surface 114 from the upper side of the sixth rising surface 124d to the fourth emission surface 124a. The distance between the fifth reflecting surface 124b and the sixth reflecting surface 124c along the X-axis direction is W1, which is the same as the distance W1 between the fourth exit surface 124a along the X-axis direction.

[0125] The length from the bottom to the top of the sixth rising surface 124d corresponds to the length required to obtain an offset (W-W1) relative to the length W1 of the fourth exit surface 124a in the X-axis direction. The amount of light totally reflected by the fifth reflecting surface 124b and then totally reflected by the sixth reflecting surface 124c is comparable to that in the case where the sixth rising surface 124d is not provided, because there is no light from the fourth bonding surface 114 of the incident section 110 at both ends of the bonding surface of the fourth light-guiding section 124 that contacts the fourth bonding surface 114 of the incident section 110.

[0126] The opposing surface on the other end side in the X-axis direction of the pair of opposing surfaces in the fifth light-guiding section 125 has an eighth rising surface 125d that is perpendicular to the fifth bonding surface 115 from the bottom surface that contacts the fifth bonding surface 115 of the incident section 110, and has an eighth reflecting surface 125c that is inclined 45 degrees toward the other end side with respect to the fifth bonding surface 115 from the upper side of the eighth rising surface 125d to the fifth exit surface 125a. The distance between the seventh reflecting surface 125b and the eighth reflecting surface 125c along the X-axis direction is (W1+W2).

[0127] The spacing W2 of the fifth exit surface 125a along the X-axis direction is the value obtained by subtracting the spacing W1 along the X-axis direction between the fifth reflecting surface 124b and the sixth reflecting surface 124c in the fourth light-guiding section 124 from the spacing (W1+W2) between the seventh reflecting surface 125b and the eighth reflecting surface 125c along the X-axis direction. The distance (W1+W2) along the X-axis direction between the seventh reflecting surface 125b and the eighth reflecting surface 125c of the fifth light guiding section 125 is shorter than 2W1, which is twice the distance W1 along the X-axis direction between the fifth reflecting surface 124b and the sixth reflecting surface 124c of the fourth light guiding section 124.

[0128] The length from the bottom to the top of the eighth rising surface 125d corresponds to the offset amount (W-W2) relative to the length W2 of the fifth exit surface 125a in the X-axis direction, in other words, the length required to obtain (2W-(W1+W2)). The amount of light totally reflected by the seventh reflecting surface 125b and then totally reflected by the eighth reflecting surface 125c is comparable to that in the case where the eighth rising surface 125d is not provided, because there is no light from the fifth bonding surface 115 of the incident section 110 at both ends of the bonding surface of the fifth light-guiding section 125 that contacts the fifth bonding surface 115 of the incident section 110.

[0129] The total length in the X-axis direction of first exit surface 121a to fifth exit surface 125a (W+2(W1+W2)) is 5W, the total length W of all lengths being 5W, which is shorter by 5W-((W+2(W1+W2))), that is, 4W-2(W1+W2).

[0130] Light distribution formation section 200 differs from light distribution formation section 200 in embodiment 1 only in its length in the X-axis direction, and is otherwise the same. The first condensing optical unit 211 is the same as the first condensing optical unit 211 in the first embodiment. The length in the X-axis direction of the second focusing optical unit 212 and the fourth focusing optical unit 214 is W1, which is the same as the distance W1 along the X-axis direction between the second exit surface 122a and the fourth exit surface 124a.

[0131] The length of second light distribution section 222 and fourth light distribution section 224 in the X-axis direction is W1, which is the same as the interval W1 along the X-axis direction between second emission surface 122a and fourth emission surface 124a. The length of the second projection lens 232 and the fourth projection lens 234 in the X-axis direction is W1, which is the same as the distance W1 along the X-axis direction between the second exit surface 122a and the fourth exit surface 124a.

[0132] The length in the X-axis direction of the third focusing optical unit 213 and the fifth focusing optical unit 215 is W2, which is the same as the distance W2 along the X-axis direction between the third exit surface 123a and the fifth exit surface 125a. The length of third light distribution section 223 and fifth light distribution section 225 in the X-axis direction is W2, which is the same as the interval W2 along the X-axis direction between third exit surface 123a and fifth exit surface 125a.

[0133] The length of each of the third projection lens 233 and the fifth projection lens 235 in the X-axis direction is W2, which is the same as the distance W2 between the third exit surface 123a and the fifth exit surface 125a along the X-axis direction. The total length in the X-axis direction of the first projection surface 231a to the fifth projection surface 235a, which are arranged in a row along the X-axis (W+2(W1+W2)), is 4W-2(W1+W2) shorter than the total length W of 5W.

[0134] As described above, the light-source distribution element 100 according to the third embodiment has the same effects as the light-source distribution element 100 according to the first embodiment, and in addition, the length in the X-axis direction can be shortened, and the structure can be simplified without reducing the light utilization efficiency, thereby shortening the width direction and making the element thinner. Furthermore, by including the light source distribution element 100 and the light distribution forming section 200 described above, the headlight module according to embodiment 3 can be made shorter in width and thinner in height without reducing the light utilization efficiency by simplifying the structure.

[0135] Embodiment 4 A headlamp module according to a fourth embodiment will be described with reference to FIGS. The headlight module according to the fourth embodiment differs from the headlight module according to the third embodiment in that a cutoff line forming surface 220a is provided in the collected light distribution section 220 of the light distribution forming section 200. 27 to 32, the same reference numerals as those in FIGS. 1 to 10 and 19 to 26 indicate the same or corresponding parts.

[0136] The following mainly describes the differences from the headlamp module according to the third embodiment. Since the light distribution forming section 200 is basically the same as the headlamp module according to the third embodiment except for the collected light distribution section 220, the description will be centered on the collected light distribution section 220. The collective light distribution section 220 has a cutoff line forming surface 220a on its bottom surface, i.e., the surface located on the side of the incident section 110 in the Y-axis direction, which has a ridge line for forming a cutoff line along the X-axis direction, and the section from the ridge line of the cutoff line forming surface 220a to the front surface of the collective light-collecting optical section 210 is the first region section 220A, and the section from the ridge line of the cutoff line forming surface 220a to the projection section 230 is the second region section 220B.

[0137] In the first region 220A, the bottom surface is a horizontal surface along the ZX plane, and the top surface opposite the bottom surface is also a horizontal surface along the ZX plane. To form a cutoff line, the bottom surface may be inclined in the Z-axis direction relative to the ZX plane, and the top surface may also be inclined in the Z-axis direction relative to the ZX plane. Furthermore, at least one of the bottom surface and the top surface may be changed to a surface parallel to the ZX plane. The first region 220A has a reflecting surface on the bottom surface thereof.

[0138] The collective light distribution unit 220 totally reflects light from the front surface of the collective focusing optical unit 210 by the cutoff line forming surface 220a, which is a reflective surface in the first region 220A, and propagates the light, on which a cutoff line has been formed, to the projection unit 230 via the second region 220B. The bottom and top surfaces of the second region 220B are horizontal surfaces along the ZX plane, like the bottom and top surfaces of the first region 220A, but may be surfaces that are inclined toward the Z-axis direction relative to the ZX plane, or surfaces that are parallel to the ZX plane.

[0139] The first light distribution section 221 constituting the collective light distribution section 220 has a first cutoff line forming surface 221a having a ridge line for forming a cutoff line along the X-axis direction. The first region 221A is the area from the ridge line of the first cutoff line forming surface 221a to the front surface of the first light collecting optical section 211, and the second region 221B is the area from the ridge line of the first cutoff line forming surface 221a to the first projection lens 231.

[0140] In the first region 221A, the bottom surface is located on the incident portion 110 side and is a horizontal plane along the ZX plane. The top surface is also a horizontal plane along the ZX plane. The bottom surface of the first region 221A has a first cutoff line forming surface 221a, which is a reflective surface. The length in the X-axis direction of a pair of opposing surfaces that face each other parallel to the X-axis direction, i.e., the distance between them, is W. A portion of the light beam L1 from the front surface of the first light collecting optical unit 211 is reflected by the first cutoff line forming surface 221a. The light reflected by the first cutoff line forming surface 221a and having a cutoff line formed thereon is guided to the first projection lens 231 via the second area 221B.

[0141] Furthermore, the remaining light of the light beam L1 from the front surface of the first light-collecting optical unit 211 is not reflected by the first cutoff line forming surface 221a and is guided directly to the first projection lens 231 via the second area 221B. The light reflected by the first cutoff line forming surface 221a and the light not reflected by the first cutoff line forming surface 221a are combined to form a cutoff light distribution, which is projected as a low beam from the first projection lens 231.

[0142] The second light distribution section 222 constituting the collective light distribution section 220 has a second cutoff line forming surface 222a having a ridge line for forming a cutoff line along the X-axis direction. The first region 222A is the area from the ridge line of the second cutoff line forming surface 222a to the front surface of the second concentrating optical section 212, and the second region 222B is the area from the ridge line of the second cutoff line forming surface 222a to the second projection lens 232.

[0143] In the first region 222A, the bottom surface is located on the incident portion 110 side and is a horizontal plane along the ZX plane. The top surface is also a horizontal plane along the ZX plane. The bottom surface of the first region 222A has a second cutoff line forming surface 222a, which is a reflective surface. The length in the X-axis direction of a pair of opposing surfaces that face each other parallel to the X-axis direction, i.e., the distance between them, is W. A portion of the light beam L2 from the front surface of the second converging optical unit 212 is reflected by the second cutoff line forming surface 222a. The light reflected by the second cutoff line forming surface 222a and having a cutoff line formed thereon is guided to the second projection lens 232 via the second region 222B.

[0144] Furthermore, the remaining light of the light beam L2 from the front surface of the second light-collecting optical unit 212 is not reflected by the second cutoff line forming surface 222a and is guided directly to the second projection lens 232 via the second area 222B. The light reflected by the second cutoff line forming surface 222a and the light not reflected by the first cutoff line forming surface 222a are combined to form a cutoff light distribution, which is projected as a low beam from the second projection lens 232.

[0145] The third light distribution section 223 constituting the collective light distribution section 220 has a third cutoff line forming surface 223a having a ridge line for forming a cutoff line along the X-axis direction. The first region 223A is the area from the ridge line of the third cutoff line forming surface 223a to the front surface of the third concentrating optical section 213, and the second region 223B is the area from the ridge line of the third cutoff line forming surface 223a to the third projection lens 233.

[0146] In the first region 223A, the bottom surface is located on the incident portion 110 side and is a horizontal plane along the ZX plane. The top surface is also a horizontal plane along the ZX plane. The bottom surface of the first region 223A has a third cutoff line forming surface 223a, which is a reflective surface. The length in the X-axis direction of a pair of opposing surfaces that face each other parallel to the X-axis direction, i.e., the distance between them, is W. A portion of the light beam L3 from the front surface of the third converging optical unit 213 is reflected by the third cutoff line forming surface 223a. The light reflected by the first cutoff line forming surface 223a and having a cutoff line formed thereon is guided to the third projection lens 233 via the second region 223B.

[0147] Furthermore, the remaining light of the light beam L3 from the front surface of the third converging optical unit 213 is not reflected by the third cutoff line forming surface 223a, but is directly guided to the second projection lens 232 via the second area 223B. The light reflected by the third cutoff line forming surface 223a and the light not reflected by the third cutoff line forming surface 223a are combined to form a cutoff light distribution, which is projected from the second projection lens 232 as a low beam.

[0148] The fourth light distribution section 224 constituting the collective light distribution section 220 has a fourth cutoff line forming surface 224a having a ridge line for forming a cutoff line along the X-axis direction. The first region 224A is the area from the ridge line of the fourth cutoff line forming surface 224a to the front surface of the fourth concentrating optical section 214, and the second region 224B is the area from the ridge line of the fourth cutoff line forming surface 224a to the fourth projection lens 234.

[0149] In the first region 224A, the bottom surface is located on the incident portion 110 side and is a horizontal plane along the ZX plane. The top surface is also a horizontal plane along the ZX plane. The bottom surface of the first region 224A has a fourth cutoff line forming surface 224a, which is a reflective surface. The length in the X-axis direction of the pair of opposing surfaces that face each other parallel to the X-axis direction, i.e., the distance between them, is W. A portion of the light beam L4 from the front surface of the fourth converging optical unit 214 is reflected by the fourth cutoff line forming surface 224a. The light reflected by the fourth cutoff line forming surface 224a and having a cutoff line formed thereon is guided to the fourth projection lens 234 via the second region 224B.

[0150] Furthermore, the remaining light of the light beam L4 from the front surface of the fourth converging optical unit 214 is not reflected by the fourth cutoff line forming surface 224a and is guided directly to the fourth projection lens 234 via the second area 224B. The light reflected by the fourth cutoff line forming surface 224a and the light not reflected by the fourth cutoff line forming surface 224a are combined to form a cutoff light distribution, which is projected as a low beam from the fourth projection lens 234.

[0151] The fifth light distribution section 225 constituting the collective light distribution section 220 has a fifth cutoff line forming surface 225a having a ridge line for forming a cutoff line along the X-axis direction. The first region 225A is the area from the ridge line of the fifth cutoff line forming surface 225a to the front surface of the fifth concentrating optical section 215, and the second region 225B is the area from the ridge line of the fifth cutoff line forming surface 225a to the fifth projection lens 235.

[0152] In the first region 225A, the bottom surface is located on the incident portion 110 side and is a horizontal plane along the ZX plane. The top surface is also a horizontal plane along the ZX plane. The bottom surface of the first region 225A has a fifth cutoff line forming surface 225a, which is a reflective surface. The length in the X-axis direction of a pair of opposing surfaces that face each other parallel to the X-axis direction, i.e., the distance between them, is W. A portion of the light beam L5 from the front surface of the fifth converging optical unit 215 is reflected by the fifth cutoff line forming surface 225a. The light reflected by the fifth cutoff line forming surface 225a and having a cutoff line formed thereon is guided to the fifth projection lens 235 via the second area 225B.

[0153] In addition, the remaining light of the light beam L5 from the front surface of the fifth focusing optical unit 215 is not reflected by the fifth cutoff line forming surface 225a and is guided directly to the fifth projection lens 235 via the second area portion 225B. The light reflected by the fifth cutoff line forming surface 225a and the light not reflected by the fifth cutoff line forming surface 225a are combined to form a cutoff light distribution, which is projected as a low beam from the fifth projection lens 235.

[0154] The ridge lines for forming the cutoff lines of each of the first cutoff line forming surface 221a to the fifth cutoff line forming surface 225a are the underlines at the joint surfaces of the first area portions 221A to 225A and the second area portions 221B to 225B, respectively, that is, the front edge of the reflecting surface of the bottom surface of each of the first area portions 221A to 225A. The ridge line for forming the cutoff line is positioned so that the upper side, i.e., the outside of the light distribution pattern, is dark and the lower side, i.e., the inside of the light distribution pattern, is bright.

[0155] The headlight module of embodiment 4 configured in this manner not only achieves the same effects as the headlight module of embodiment 3, but also has a cutoff line forming surface 220a for forming a cutoff line in the collective light distribution unit 220, so that the light projected from the projection unit 230 can be projected forward as low beam irradiation light, which is light of a light distribution pattern having a cutoff line. Furthermore, by changing the shape of the ridge line for forming the cutoff line of each of the cutoff line forming surfaces 221a to 225a of the first light distribution section 221 to the fifth light distribution section 225, a light distribution pattern having a desired cutoff line shape can be obtained.

[0156] In the headlight module according to embodiment 4, the first light distribution section 221 to the fifth light distribution section 225 each have their own cutoff line forming surfaces 221a to 225a, first region sections 221A to 225A, and second region sections 221B to 225B, but the cutoff line forming surfaces may be continuous in the X-axis direction. That is, the cutoff line forming surfaces 221a to 225a are all rectangular with no steps located on the same plane.

[0157] The first light distribution section 221 to the fifth light distribution section 225 in the first and second embodiments may be replaced with the first light distribution section 221A to the fifth light distribution section 225A having the cutoff line forming surfaces 221a to 225a, respectively, of the fourth embodiment, thereby making it possible to obtain a light distribution pattern having a desired cutoff line shape.

[0158] Furthermore, the embodiments may be freely combined, or any of the components in each embodiment may be modified, or any of the components in each embodiment may be omitted. [Industrial Applicability]

[0159] The light source distribution element for a headlamp device and the headlamp module according to the present disclosure are suitable for use in headlamp devices for automobiles and motorcycles, particularly in low-beam headlights. [Explanation of symbols]

[0160] 1 light source, 100 light source distribution element for headlamp device, 110 incident portion, 111 first bonding surface, 112 second bonding surface, 113 third bonding surface, 114 fourth bonding surface, 115 fifth bonding surface, 120 collective light guiding portion, 121 first light guiding portion, 122 second light guiding portion, 123 third light guiding portion, 124 fourth light guiding portion, 125 fifth light guiding portion, 121a first exit surface, 122a second exit surface, 123a third exit surface, 124a fourth exit surface, 125a fifth exit surface, 122b first reflecting surface, 122c second reflecting surface, 123b third reflecting surface, 123c fourth reflecting surface, 124b fifth reflecting surface, 124c Sixth reflecting surface, 125b Seventh reflecting surface, 125c Eighth reflecting surface, 200 Light distribution forming portion, 210 Collecting and concentrating optical portion, 211 First concentrating optical portion, 212 Second concentrating optical portion, 213 Third concentrating optical portion, 214 Fourth concentrating optical portion, 215 Fifth concentrating optical portion, 220 Collecting and concentrating optical portion, 220A First region, 220B Second region, 220a Cutoff line forming surface, 221 First light distribution portion, 221a First cutoff line forming surface, 222 Second light distribution portion, 222a Second cutoff line forming surface, 223 Third light distribution portion, 223a Third cutoff line forming surface, 224 Fourth light distribution portion, 224a Fourth cutoff line forming surface, 225 Fifth light distribution portion, 225a Fifth cutoff line forming surface, 230 projection unit, 231 first projection lens, 232 second projection lens, 233 third projection lens, 234 fourth projection lens, 235 fifth projection lens, 231a first projection surface, 232a second projection surface, 233a third projection surface, 234a fourth projection surface, 235a fifth projection surface, L1 to L5 first light beam to fifth light beam.

Claims

1. an incident portion to which light from a light source is incident and which has three or more bonding surfaces positioned along one direction in a plane perpendicular to an optical axis of the light source; a plurality of light guide sections each having a pair of opposing surfaces facing each other in one direction in a plane perpendicular to the optical axis of the light source and having a rectangular cross section parallel to the plane perpendicular to the optical axis of the light source, each having an exit surface corresponding to each of the plurality of bonding surfaces of the incident section, and each guiding light from the corresponding bonding surface to the corresponding exit surface; Among the plurality of light guiding sections, each of the pair of opposing surfaces of a light guiding section whose exit surface is located on one end side in the other direction relative to the light source has a reflection surface on one end side that is inclined with respect to the optical axis of the light source, Among the plurality of light guiding sections, each of the pair of opposing surfaces of a light guiding section whose exit surface is located on the other end side in the other direction relative to the light source has a reflection surface on the other end side that is inclined with respect to the optical axis of the light source. A light source distribution element for a headlamp device.

2. 2. The light source distribution element for a headlamp device according to claim 1, wherein the reflecting surface inclined with respect to the optical axis of the light source is inclined at 45 degrees with respect to the optical axis of the light source.

3. 2. The light source distribution element for a headlamp device according to claim 1, wherein the incident portion and the plurality of light guide portions are integrally formed from a transparent material.

4. the plurality of bonding surfaces of the incident portion are divided in the one direction, and include five bonding surfaces including a first bonding surface located in a central portion, a second bonding surface and a third bonding surface located in this order from the central portion toward one end side in the one direction, and a fourth bonding surface and a fifth bonding surface located in this order from the central portion toward the other end side in the one direction, the plurality of light guiding units are five light guiding units consisting of first to fifth light guiding units, each having a first to fifth light exit surface, a pair of opposing surfaces of the first light guiding unit are parallel to an optical axis of the light source, and the first light guiding unit guides light from a first joint surface of the incident unit to the first exit surface; a first reflecting surface and a second reflecting surface, which are a pair of reflecting surfaces of the second light guiding unit, are inclined toward one end side in the other direction with respect to the optical axis of the light source, the first reflecting surface is located on the optical axis side of the light source, and the second reflecting surface is located on the one end side in the other direction, and the second light guiding unit reflects light from a second joint surface of the incident unit to the second reflecting surface by the first reflecting surface, and the second reflecting surface reflects light to the second exit surface, a third reflecting surface and a fourth reflecting surface, which are a pair of reflecting surfaces of the third light guiding unit, are inclined toward one end in the other direction with respect to the optical axis of the light source; the third reflecting surface of the third light guiding unit is continuous with the first reflecting surface at one end in the one direction; the third light guiding unit is formed integrally with the second light guiding unit from the third reflecting surface to the second reflecting surface of the second light guiding unit; the fourth reflecting surface of the third light guiding unit is located at a position spaced from the position of the second reflecting surface of the second light guiding unit toward the one end in the other direction by a length of the third exit surface in the other direction; and the third reflecting surface of the third light guiding unit reflects light from a third joint surface of the incident unit to the fourth reflecting surface, and the fourth reflecting surface reflects light to the third exit surface, a fifth reflecting surface and a sixth reflecting surface, which are a pair of reflecting surfaces of the fourth light guiding unit, are inclined toward the other end side in the other direction with respect to the optical axis of the light source, the fifth reflecting surface is located on the optical axis side of the light source, and the sixth reflecting surface is located on the other end side in the other direction, and in the fourth light guiding unit, the fifth reflecting surface reflects light from a fourth joint surface of the incident unit to the sixth reflecting surface, and the sixth reflecting surface reflects light to the fourth exit surface, a seventh reflecting surface and an eighth reflecting surface, which are a pair of reflecting surfaces of the fifth light guiding unit, are inclined toward the other end side in the other direction with respect to the optical axis of the light source, the seventh reflecting surface of the fifth light guiding unit is continuous with the fifth reflecting surface on the other end side in the one direction, the fifth light guiding unit is formed integrally with the fourth light guiding unit from the seventh reflecting surface to the position of the fifth reflecting surface of the fourth light guiding unit, the eighth reflecting surface of the fifth light guiding unit is located at a position spaced apart from the sixth reflecting surface of the fourth light guiding unit on the other end side in the other direction by a length of the fifth exit surface in the other direction, and in the fifth light guiding unit, the seventh reflecting surface reflects light from the fifth joint surface of the incident unit to the eighth reflecting surface, and the eighth reflecting surface reflects light to the fifth exit surface. The light source distribution element for a headlamp device according to any one of claims 1 to 3.

5. a distance between the pair of reflecting surfaces of the third light guiding unit in the other direction is shorter than twice the distance between the pair of reflecting surfaces of the second light guiding unit in the other direction; a length in the other direction of the third exit surface of the third light guiding portion is shorter than a length in the other direction of the second exit surface of the second light guiding portion; a distance between the pair of reflecting surfaces of the fifth light guiding unit in the other direction is shorter than twice the distance between the pair of reflecting surfaces of the fourth light guiding unit in the other direction; a length in the other direction of the fifth exit surface of the fifth light guiding unit is shorter than a length in the other direction of the fourth exit surface of the fourth light guiding unit; The light source distribution element for a headlamp device according to claim 4.

6. The light-source distribution element for a headlamp device according to claim 4 , wherein the incident portion condenses incident light and guides parallel light from the first joint surface to the fifth joint surface.

7. A headlamp device comprising the light source distribution element for a headlamp device according to claim 4 and a light distribution forming unit, The light distribution forming unit is a first light-collecting optical unit that reflects and collects light from a first exit surface of the first light-guiding unit toward one end side in the one direction; a second light-collecting optical unit that reflects and collects light from the second exit surface of the second light-guiding unit toward one end side in the one direction; a third light-collecting optical unit that reflects and collects light from a third exit surface of the third light-guiding unit toward one end side in the one direction; a fourth light-collecting optical unit that reflects and collects light from a fourth exit surface of the fourth light-guiding unit toward one end side in the one direction; a fifth light-collecting optical unit that reflects and collects light from a fifth exit surface of the fifth light-guiding unit toward one end side in the one direction; a first light distribution unit that guides the light flux reflected and collected by the first light collecting optical unit; a second light distribution unit that guides the light flux reflected and collected by the second light collecting optical unit; a third light distribution unit that guides the light flux reflected and collected by the third light collecting optical unit; a fourth light distribution unit that guides the light flux reflected and collected by the fourth light collecting optical unit; a fifth light distribution unit that guides the light flux reflected and collected by the fifth light collecting optical unit; a first projection lens having a first projection surface and projecting, from the first projection surface, the light guided as a luminous flux by the first light distribution unit; a second projection lens having a second projection surface and projecting the light guided as a luminous flux by the second light distribution unit from the second projection surface; a third projection lens having a third projection surface and projecting the light guided as a luminous flux by the third light distribution unit from the third projection surface; a fourth projection lens having a fourth projection surface and projecting the light guided as a luminous flux by the fourth light distribution unit from the fourth projection surface; a fifth projection lens having a fifth projection surface and projecting the light guided as a luminous flux by the fifth light distribution section from the fifth projection surface, The first projection surface to the fifth projection surface are arranged in the other direction from one end to the other end in the order of the third projection surface, the second projection surface, the first projection surface, the fourth projection surface, and the fifth projection surface, without overlapping.

8. The first light distribution unit has a first cutoff line forming surface having a ridge for forming a cutoff line along the other direction, and projects a cutoff light distribution formed by reflecting a portion of the light from the first focusing optical unit onto the first cutoff line forming surface and guiding the remaining light from the first focusing optical unit directly to the first projection lens; the second light distribution unit has a second cutoff line forming surface having a ridge line for forming a cutoff line along the other direction, and projects a cutoff light distribution formed by reflecting a part of the light from the second converging optical unit on the second cutoff line forming surface and guiding the part of the light from the second converging optical unit to the second projection lens, and guiding the other light from the second converging optical unit directly to the second projection lens; the third light distribution unit has a third cutoff line forming surface having a ridge line for forming a cutoff line along the other direction, and projects a cutoff light distribution formed by reflecting a part of the light from the third converging optical unit on the third cutoff line forming surface and guiding the part of the light from the third converging optical unit to the third projection lens, and guiding the other light from the third converging optical unit directly to the third projection lens; the fourth light distribution unit has a fourth cutoff line forming surface having a ridge line for forming a cutoff line along the other direction, and projects a cutoff light distribution formed by reflecting a part of the light from the fourth converging optical unit on the fourth cutoff line forming surface and guiding the part of the light from the fourth converging optical unit to the fourth projection lens, and guiding the other light from the fourth converging optical unit directly to the fourth projection lens; the fifth light distribution unit has a fifth cutoff line forming surface having a ridge line for forming a cutoff line along the other direction, and projects a cutoff light distribution formed by reflecting a part of the light from the fifth converging optical unit on the fifth cutoff line forming surface and guiding the part of the light from the fifth converging optical unit to the fifth projection lens, and guiding the other light from the fifth converging optical unit directly to the fifth projection lens.

8. The headlamp module according to claim 7.

9. 8. The headlamp module according to claim 7, wherein the light source distribution element for a headlamp device and the light distribution forming portion are integrally formed from a transparent material.

10. A light source distribution element for a headlamp device according to claim 1; a light distribution forming unit having a plurality of projection surfaces positioned along the other direction, which reflects light from the exit surfaces of the plurality of light guiding units in the headlamp device light source distribution element toward one end side in the one direction and guides the light to the plurality of projection surfaces; A headlamp module comprising:

11. The light distribution forming section is a collective light-collecting optical unit that reflects and collects light from the exit surfaces of the plurality of light-guiding units toward one end in the one direction; a light collecting and distributing unit that guides the plurality of light beams reflected and collected by the light collecting optical unit to the plurality of projection surfaces; a projection unit having the plurality of projection surfaces and projecting the light guided as the plurality of luminous fluxes by the collective light distribution unit from the plurality of projection surfaces, respectively; The headlamp module of claim 10, comprising:

12. A headlight module as described in Claim 11, wherein the projection unit comprises a plurality of projection lenses, each having one of the plurality of projection surfaces.

13. A headlight module as described in Claim 10, wherein the light source distribution element for the headlight device and the light distribution forming portion are integrally formed from a transparent material.

14. A headlight module as described in claim 11 or claim 12, wherein the collective light distribution unit has a cutoff line forming surface having a ridge line for forming a cutoff line along another direction, a first region extending from the ridge line of the cutoff line forming surface to the collective focusing optical unit, and a second region extending from the ridge line of the cutoff line forming surface to the projection unit, and wherein each of the multiple light beams from the collective focusing optical unit is reflected by the cutoff line forming surface, and the light beams on which the cutoff line has been formed are guided to the projection unit via the second region.

15. A headlight module as described in Claim 14, wherein the cutoff line forming surface has cutoff line forming surfaces each having its own unique characteristics corresponding to each of the multiple light beams from the collective focusing optical unit.

16. A headlight module as described in Claim 14, wherein the cutoff line forming surface is a cutoff line forming surface located on the same plane that is continuous in the other direction with respect to multiple light beams from the collective focusing optical unit.

17. A headlight module as described in Claim 14, wherein the light source distribution element for the headlight device and the light distribution forming portion are integrally formed from a transparent material.

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