Light source distribution element for headlamp device, headlamp device, and headlamp module

Abstract

To provide a light source distribution element for a headlamp device which has a simple structure and is miniaturized without reducing light utilization efficiency. [Solution] The light source distribution element for a headlamp device comprises an incident surface 21a into which light from the light source is incident, an incident section 21 located along one direction in a plane perpendicular to the optical axis of the light source, a first exit section 22 that emits light, a second exit section 23 having a second exit surface 23a that emits light located at a different position in one direction from the first exit surface 22a of the first exit section and in another direction perpendicular to the one direction in the plane perpendicular to the optical axis of the light source, a first light guiding section 24 located between the first bonding surface 21b of the incident section 21 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 25 having a first reflecting surface 25a and a second reflecting surface formed on opposing side surfaces in the other direction, and in which the first reflecting surface and the second reflecting surface reflect light from the second bonding surface of the incident section and guide it to the second exit section 23.

Description

[Technical field]

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

[0002] 2. Description of the Related Art Headlight devices that illuminate the area in front of a vehicle body, so-called headlight devices, and particularly low-beam headlights and high-beam headlights, are desired to be thin and have improved light utilization efficiency. Patent Document 1 shows a low-beam headlight that is thin and has improved light utilization efficiency. The low beam headlight disclosed in Patent Document 1 has an LED, an LED collimator, a light guide, and a projector lens arranged along the optical axis direction.

[0003] The light guide has an entrance section, an exit section, a total reflection section, an attachment section, etc., and has a first light guide section on the rear side along the optical axis and a second light guide section on the front side consisting of two parts, left and right, with multiple total reflection surfaces arranged inside. The total reflection portions are disposed on both the left and right sides of the incident portion, and above and below the left and right sides. The light incident on the light guide does not undergo total reflection inside the light guide and is emitted as a portion of the light without being cut, and passes through multiple total reflections inside the light guide, where it is cut and reused, and emitted as another portion of the light. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] WO2020-021825 publication Summary of the Invention [Problem to be solved by the invention]

[0005] The light guide in the low beam headlight shown in Patent Document 1 has multiple total reflection surfaces inside and has a complex structure including a first light guide section and a second light guide section on the front side consisting of two sections, left and right.

[0006] The present disclosure has been made in consideration of the above-mentioned points, and has an object to provide a light source distribution element for a headlamp device that is compact and has a simplified structure without reducing light utilization efficiency. [Means for solving the problem]

[0007] A light source distribution element for a headlamp device according to the present disclosure includes an entrance section having an entrance surface into which light from a light source is incident, and having a first bonding surface and a second bonding surface positioned along one direction in a plane perpendicular to the optical axis of the light source, a first exit section having a first exit surface from which light is emitted, and a second exit section having a second exit surface from which light is emitted positioned at a different position in one direction from the first exit surface of the first exit section and in another direction perpendicular to the one direction in the plane perpendicular to the optical axis of the light source, a first light guiding section located between the first bonding surface of the incident section and the first exit section, 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, 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 guiding light from the second bonding surface of the incident section to the second exit section by having the first reflecting surface and the second reflecting surface reflected by the first reflecting surface and the second reflecting surface. If the length in one direction of the light source is h0, the divergence angle of light in one direction at the incident surface of the incident portion is θ0, the length in one direction at the first exit surface of the first exit portion is h1, the divergence angle of light in one direction at the first exit surface of the first exit portion is θ1, the length in one direction at the second exit surface of the second exit portion is h2, and the divergence angle of light in one direction at the second exit surface of the second exit portion is θ2, then the relationships h0×sinθ0>h1×sinθ1 and h0×sinθ0>h2×sinθ2 hold, and the first exit surface of the first exit portion and the second exit surface of the second exit portion each have a convex lens having refractive power on at least a portion of their surface. Effect of the Invention

[0008] According to the present disclosure, the structure can be simplified and the size can be reduced without reducing the light utilization efficiency. [Brief description of the drawings]

[0009] [Figure 1] 1 is a perspective view showing a light source distribution element for a headlamp device according to a first embodiment. [Diagram 2] 1 is a plan view showing a light collecting optical system including a light source distribution element for a headlamp device according to a first embodiment. [Diagram 3]1 is a right side view showing a light collecting optical system including a light source distribution element for a headlamp device according to a first embodiment. [Figure 4] 1 is a front view showing a light collecting optical system including a light source distribution element for a headlamp device according to a first embodiment. [Diagram 5] 3 is a schematic diagram for explaining an Abbe invariant in a light collecting optical system including a light source distribution element for a headlamp device according to the first embodiment. FIG. [Figure 6] 11 is a plan view showing a light collecting optical system including a light source distribution element for a headlamp device according to a second embodiment. FIG. [Figure 7] 11 is a right side view showing a light collecting optical system including a light source distribution element for a headlamp device according to a second embodiment. FIG. [Figure 8] FIG. 11 is a perspective view showing a light source distribution element for a headlamp device according to a third embodiment. [Figure 9] 11 is a plan view showing a light collecting optical system including a light source distribution element for a headlamp device according to a third embodiment. FIG. [Figure 10] 11 is a right side view showing a light collecting optical system including a light source distribution element for a headlamp device according to a third embodiment. FIG. [Figure 11] 11 is a front view showing a light collecting optical system including a light source distribution element for a headlamp device according to a third embodiment. FIG. [Figure 12] FIG. 11 is a right side view showing a headlight device according to a fourth embodiment. [Figure 13] FIG. 13 is a right side view showing a headlight module according to a fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Embodiment 1 A light-source distribution element 2 for a headlamp device (hereinafter, abbreviated as light-source distribution element 2) according to a first embodiment will be described with reference to Figs. 1 to 5. Figs. The light source distribution element 2 is used in a headlamp device that illuminates the front of a motorcycle, an automobile, or a three-wheeled vehicle called a gyro (a three-wheeled scooter or motorized bicycle with one front wheel and two rear wheels on a single axle) that satisfies a specified light distribution pattern defined by road traffic regulations, etc. The headlamp device has a low beam and a high beam.

[0011] The light-source distribution element 2 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 a motorcycle will be described. When applied to a low beam of an automobile headlamp device, the light collecting optical system 100 including the light source distribution element 2 may be one, or a plurality of light collecting optical systems 100 may be arranged in parallel in the left-right direction.

[0012] Before specifically describing the light-source distribution element 2, the terms used in this disclosure will be explained. Light distribution refers to the luminous intensity distribution of a light source in space, that is, the spatial distribution of light emitted from a light source. Luminous intensity indicates the degree of strength of light emitted by an illuminant, and is calculated by dividing the luminous flux passing through a small solid angle in a certain direction by that small solid angle.

[0013] Road traffic regulations require that the low beams of motorcycle headlamp devices and automobile headlamp devices have a horizontally elongated light distribution pattern that is narrow in the vertical direction, and in order not to dazzle oncoming vehicles, the upper light boundary line of the light distribution pattern, i.e., the cut-off line, must be clear. 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 light distribution is the distribution of light intensity in the direction of light emitted from a light source. The light distribution is also used to mean the illuminance distribution on an illuminated surface.

[0014] The required cutoff line being clear 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.

[0015] The cut-off line is a dividing line between light and dark that is produced when light from a headlamp device is irradiated onto a wall or a screen, and is the upper dividing line of a light distribution pattern. That is, the cutoff line is the boundary line between the light and dark 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, that is, the inside of the light distribution pattern, and the dark area, that is, the outside of the light distribution pattern. The cutoff line is a term used when adjusting the irradiation direction of a headlamp device for passing vehicles. A headlamp device for passing vehicles is also called a low beam.

[0016] 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 illuminates a distant object. In order to realize a clear cutoff line, the cutoff line must not have significant chromatic aberration, blur, etc. Blurring of the cutoff line means that the cutoff line becomes unclear.

[0017] 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, that is, in the area inside the light distribution pattern. In a low beam headlamp device for an automobile, the cut-off line has a stepped shape having a rising line. Furthermore, because headlamp devices are disposed at the front of an automobile, design is important, and there is a demand for headlamp devices with increased freedom in design. If a headlamp device is designed to be thin in the vertical direction of a vehicle in order to improve design, the light utilization efficiency will be low.

[0018] The light source distribution element 2 in embodiment 1 has a thin vertical thickness of the light emission surface to improve design, and is compact without reducing light utilization efficiency by focusing on Abbe's invariant (Abbe's sine condition or the conservation law of etendue).

[0019] 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 traveling direction of the vehicle. In other words, "forward" refers to the direction in which the headlamp device irradiates light. In the light-source distribution element 2 according to the first embodiment, the X-axis direction is the other direction.

[0020] 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 forward direction, 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 shine.

[0021] The ZX plane is a plane 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, for example, uphill or downhill, relative to the direction of travel of the vehicle.

[0022] Furthermore, while it is rare for a typical road surface to be inclined left or right with respect to the vehicle's traveling direction, 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 assumes 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.

[0023] The light source distribution element 2 will be specifically described below. First, a light collection optical system 100 including a light source distribution element 2 includes a light source 1, as shown in FIGS. The light source 1 emits light for illuminating the area ahead of the vehicle. The light source 1 is disposed on the negative side of the Z axis of the light source distribution element 2, and emits light in the positive direction of the Z axis. The optical axis of the light source 1 coincides with the optical axis of the light collecting optical system 100. The light source 1 has a rectangular, in this example, square emission surface that emits light to the front.

[0024] 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).

[0025] From the perspective of reducing the burden on the environment by suppressing 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 a smaller, lighter optical system. The light collecting optical system 100 in this disclosure uses an LED, which is one type of semiconductor light source.

[0026] As shown in FIGS. 1 to 4, the light-source distribution element 2 includes an entrance portion 21, a first exit portion 22, a second exit portion 23, a first light-guiding portion 24, and a second light-guiding portion 25. The incident portion 21 has an incident surface 21a onto which light from the light source 1 is incident, and has a first bonding surface 21b and a second bonding surface 21c positioned along the vertical direction, which is one direction in a plane perpendicular to the optical axis of the light source 1. Note that the first bonding surface 21b and the second bonding surface 21c are not physical bonding surfaces, but are virtual surfaces that indicate the boundary surfaces between the input section 21 and the first output section 22 and the second output section 23.

[0027] The incident portion 21 has a rectangular parallelepiped base 21A and a lens 21B that is integrally formed with the base 21A and has, at least in part, an incident surface 21a that is convex and has positive refractive power. Lens 21B is a convex lens whose joint surface with base 21A is rectangular or circular. The incident portion 21 uses the lens 21B to focus the light emitted from the light source 1 incident from the incident surface 21a with a small divergence angle, and guides the light as parallel light, ideally as collimated light, to the first bonding surface 21b and the second bonding surface 21c via the base portion 21A.

[0028] Base 21A of incident portion 21 has a square vertical plane that is perpendicular to the YX plane, i.e., the horizontal plane (ZX plane) and perpendicular to the optical axis. First bonding surface 21b is located in the lower half of the vertical plane, and second bonding surface 21c is located in the upper half of the vertical plane. The sum of the area of ​​the first joint surface 21b and the area of ​​the second joint surface 21c may be equal to the area of ​​the vertical surface of the base portion 21A. Furthermore, the shape of the vertical surface is not limited to a square, but may be a rectangle; in short, it is a rectangle, with the first bonding surface 21b located below and the second bonding surface 21c located above, and the sum of the areas of the first bonding surface 21b and the second bonding surface 21c being the area of ​​the vertical surface of base 21A.

[0029] The first emission section 22 has a first emission surface 22a from which light is emitted, and a third bonding surface 22b parallel to the first emission surface 22a. The first emission surface 22a and the third bonding surface 22b are parallel to the first bonding surface 21b of the incidence portion 21 and have the same shape.

[0030] The second emission section 23 has a second emission surface 23a from which light is emitted, and a fourth bonding surface 23b parallel to the second emission surface 23a. The second emission surface 23a and the fourth bonding surface 23b are parallel to the second bonding surface 21c of the incidence portion 21 and have the same shape.

[0031] The second exit surface 23a emits light at a different position in one direction from the first exit surface 22a of the first exit section 22, i.e., the up-down direction, and in another direction perpendicular to the one direction in a plane perpendicular to the optical axis of the light source 1, i.e., the left-right direction. The upper left side of first emission portion 22 and the lower right side of second emission portion 23 are in contact, and the upper left corner of first emission surface 22a and the lower right corner of second emission surface 23a coincide. It should be noted that the upper left corner of first exit surface 22a and the lower right corner of second exit surface 23a do not necessarily need to coincide with each other.

[0032] Moreover, the first exit surface 22a and the second exit surface 23a may be physical exit surfaces, or may be virtual exit surfaces. The first exit surface 22a and the second exit surface 23a are light emission reference surfaces that serve as a reference for the amount of light emitted from the light-source distribution element 2, regardless of whether they are physically present or virtual exit surfaces. In addition, the third bonding surface 22b and the fourth bonding surface 23b do not have physical bonding surfaces, but are virtual surfaces indicating the boundary surface between the first emission section 22 and the first light-guiding section 24, and virtual surfaces indicating the boundary surface between the second emission section 23 and the second light-guiding section 25.

[0033] The first light guiding section 24 is located between the first bonding surface 21b of the incident section 21 and the third bonding surface 22b of the first exit section 22, and guides the light from the first bonding surface 21b of the incident section to the first exit section 22. The first light guiding section 24 has a rectangular parallelepiped shape that linearly connects the first bonding surface 21b and the third bonding surface 22b, and the shape of the vertical cross section that is the YX plane is the same as the shape of the first bonding surface 21b and the third bonding surface 22b.

[0034] The light guided from the first joint surface 21b of the incident portion 21 to the first light guiding portion 24, which is a portion of the light from the light source 1 that is incident on the incident surface 21a of the incident portion 21, travels straight parallel to the optical axis of the light source 1 as the first light L1, as shown by the two-dotted dashed arrow in Figures 1 to 3, is guided to the third joint surface 22b of the first exit portion 22, and is emitted from the first exit surface 22a of the first exit portion 22 as light parallel to the optical axis of the light source 1.

[0035] The second light-guiding section 25 is located between the second bonding surface 21c of the incident section 21 and the fourth bonding surface 23b of the second exit section 23, and has a first reflecting surface 25a formed on the right side of the opposing side surface in the other direction, i.e., the left-right direction, and a second reflecting surface 25b formed on the left side of the opposing side surface in the left-right direction, and the first reflecting surface 25a and the second reflecting surface 25b reflect light from the second bonding surface 21c of the incident section 21 and guide it to the second exit section 23.

[0036] The second light-guiding section 25 has a rectangular shape that connects the second bonding surface 21c and the fourth bonding surface 23b in a straight line inclined at 45 degrees to the left and right with respect to the optical axis of the light source 1, in this example, to the left, and the shape of the vertical cross section that is the YX plane is the same shape as the second bonding surface 21c and the fourth bonding surface 23b. The right and left side surfaces of second light guiding section 25 are inclined at 45 degrees to the left, and are parallel to each other.

[0037] The second light-guiding section 25 has a first bent portion that bends in the other direction, in this example, to the left, and a second bent portion that bends in the opposite direction to the first bent portion, the first bent portion being at the second bonding surface 21c of the incident section 21, and the second bent portion being the fourth bonding surface 23b of the second exit section 23.

[0038] The light guided from the second joint surface 21c of the incident portion 21 to the second light guiding portion 25, which is another part of the light from the light source 1 incident on the incident surface 21a of the incident portion 21, travels straight parallel to the optical axis of the light source 1 as second light L2, as shown by the dotted arrows in Figures 1 to 3, and the light that reaches the first reflecting surface 25a is totally reflected at a right angle by the first reflecting surface 25a. The light that is totally reflected by first reflecting surface 25a and reaches second reflecting surface 25b is totally reflected at a right angle by second reflecting surface 25b and is guided to fourth bonding surface 23b of second emission part 23. The light guided to the fourth bonding surface 23b is emitted from the second emission surface 23a of the second emission section 23 as light parallel to the optical axis of the light source 1.

[0039] The light-source distribution element 2 includes an entrance portion 21, a first exit portion 22, a second exit portion 23, a first light guiding portion 24, and a second light guiding portion 25, which are integrally formed from a transparent material. The light source distribution element 2 is manufactured by injection molding and is a transparent material filled with a refractive material.

[0040] The material from which the light source distribution element 2 is manufactured is preferably highly transparent from the viewpoint of light utilization efficiency, and is preferably heat-resistant because it 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), cycloolefin resins, and the like.

[0041] The light source distribution element 2 of embodiment 1 configured as described above guides light from the light source 1 into the inside of the incident portion 21 by using the incident surface 21a of the incident portion 21 to reduce the divergence angle of the light, and uses two light guiding portions, the first light guiding portion 24 and the second light guiding portion 25, to split and branch the incident light beam incident on the incident portion 21 into two in the vertical direction, and emits the branched light beams from the first exit surface 22a of the first exit portion 22 and the second exit surface 23a of the second exit portion 23.

[0042] In this way, by dividing and branching the incident light beam incident on the entrance section 21 into two in the vertical direction by the first light-guiding section 24 and the second light-guiding section 25, the apparent size of the light source in the division direction relative to the first exit surface 22a of the first exit section 22 and the second exit surface 23a of the second exit section 23, which are the light-emitting reference surfaces, i.e., in the vertical direction, can be made smaller than the light source size of a light source that is not divided into two. At this time, the total light emitting surface size of first exit surface 22 a of first exit portion 22 and second exit surface 23 a of second exit portion 23 is the same as the light source size based on the light from light source 1 .

[0043] Therefore, the light utilization efficiency of the light source distribution element 2 does not deteriorate, and the light-collecting optical system 100 can be made thinner in the vertical direction. This point will be explained further. The apparent size of a light source is defined by the "Abbe invariant," which is the product of the divergence angle in a direction of the light source and the length of a side of the light source in that direction.

[0044] Now, as shown in Figures 3 and 5, if the height of light source 1, i.e., the vertical length, is h0, the vertical divergence angle of light from light source 1 is θ0, the vertical length of first emission surface 22a of first emission section 22, i.e., the length of the vertical side, is h1, and the vertical divergence angle of light emitted from first emission surface 22a is θ1, then the relationship represented by the following equation (1) is satisfied. h0×sin θ0>h1×sin θ1 ···(1)

[0045] As an example, if the vertical length h0 of the LED which is the light source 1 is 1 mm, the vertical divergence angle θ0 of the light from the LED is 90 degrees, the vertical length h1 of the first light exit surface 22a is 9.0 mm, and the vertical divergence angle θ1 of the light emitted from the first light exit surface 22a is 3 degrees, then the left side of equation (1) becomes the following equation (2), and the right side of equation (1) becomes the following equation (3). h0×sin θ0=1.0 (2) h1 × sin θ1 = 0.47 (3)

[0046] As is clear from formulas (2) and (3), the light-collection optical system 100 satisfies formula (1). Therefore, in the direction in which the light flux of the light source is divided, i.e., in the vertical direction, the apparent size in the vertical direction of the first exit surface 22a of the first exit section 22, which is the light emitting reference surface, and the second exit surface 23a of the second exit section 23, can be made smaller than the light source size of a light source that is not divided in two. As a result, a decrease in the light utilization efficiency due to the light source distribution element 2 can be prevented, and the light-collecting optical system 100 can be made thinner in the vertical direction.

[0047] In short, in the light source distribution element 2 of embodiment 1, the product of the vertical length h0 of the first exit surface 22a of the first emission section 22 and the vertical divergence angle θ1 of the light emitted from the first exit surface 22a is set to a value smaller than the product of the vertical length h1 of the light source 1 and the vertical divergence angle θ0 of the light from the light source 1.

[0048] In addition, the product of the vertical length h2 of the second exit surface 23a of the second exit section 23 and the vertical divergence angle θ2 of the light emitted from the second exit surface 23a is set to a value smaller than the product of the vertical length h0 of the light source 1 and the vertical divergence angle θ0 of the light from the light source 1, similar to the relationship between the first exit surface 22a and the light source 1. That is, it is set so as to satisfy the following formula (4). h0×sinθ0>h2×sinθ2 (4)

[0049] As described above, the light-source distribution element 2 of embodiment 1 includes the first light-guiding section 24, which is located between the first bonding surface 21b of the incident section 21 and the first exit section 22 and guides light from the first bonding surface 21b of the incident section 21 to the first exit section 22, and the second light-guiding section 25, which is located between the second bonding surface 21c of the incident section 21 and the second exit section 23 and has a first reflecting surface 25a formed on one of the opposing side surfaces in the other direction and a second reflecting surface 25b formed on the other of the opposing side surfaces in the other direction, and which reflects light from the second bonding surface 21c of the incident section 21 by the first reflecting surface 25a and the second reflecting surface 25b and guides it to the second exit section 23. Therefore, the light-source distribution element 2 of embodiment 1 can be made compact without reducing the light utilization efficiency by simplifying the structure.

[0050] That is, if one direction is the up-down direction and the other direction is the left-right direction, a thin light-collecting optical system 100 can be manufactured. In the light-source distribution element 2 in the first embodiment, the number of divisions of the luminous flux is two in the vertical direction, but the number is not limited to this, and may be three or more in the vertical direction, or may be four in total, two each in the vertical and horizontal directions. In short, it is sufficient to provide a plurality of light guiding sections having a plurality of exit sections, each of which guides light from an entrance section to each of the plurality of exit sections.

[0051] Alternatively, first exit surface 22a may be divided into two in the vertical direction, and each of the divided surfaces may be regarded as first bonding surface 21b and second bonding surface 21c of entrance portion 21, with first light guiding section 24 and first exit portion 22 formed with respect to first bonding surface 21b, and second light guiding section 25 and second exit portion 23 formed with respect to second bonding surface 21c. Second exit surface 23a may be divided into two in the vertical direction, and each of the divided surfaces may be regarded as first bonding surface 21b and second bonding surface 21c of entrance portion 21, with first light guiding section 24 and first exit portion 22 formed with respect to first bonding surface 21b, and second light guiding section 25 and second exit portion 23 formed with respect to second bonding surface 21c.

[0052] Embodiment 2 A light-source distribution element 2 according to the second embodiment will be described with reference to FIGS. The light source distribution element 2 of embodiment 2 differs from the light source distribution element 2 of embodiment 1 in that the first exit portion 22 and the second exit portion 23 each have a first exit surface 22a and a second exit surface 23a, each of which has a convex shape with positive refractive power, but is otherwise the same. In addition, in Figs. 6 and 7, the same reference numerals as those shown in Figs. 1 to 4 indicate the same or corresponding parts.

[0053] The following mainly describes the differences from the light-source distribution element 2 according to the first embodiment. The first exit section 22 has a rectangular parallelepiped base 22A having a third bonding surface 22b which is a bonding surface with the first light-guiding section 24, and a lens 22B which is integrally formed with the base 22A on a surface opposite to the third bonding surface 22b and has a first exit surface 22a which is convex in shape and has positive refractive power at least in part on its surface. The first emission unit 22 collects light by the lens 22B and emits the collected light from the first emission surface 22a.

[0054] The second exit section 23 has a rectangular parallelepiped base 23A having a fourth bonding surface 23b which is a bonding surface with the second light-guiding section 25, and a lens 23B which is integrally formed with the base 23A on a surface opposite to the fourth bonding surface 23b and has a convex second exit surface 23a on at least a portion of its surface, the second exit surface 23a having a positive refractive power. The second emission unit 23 collects light by the lens 23B and emits the collected light from the second emission surface 23a.

[0055] The light source distribution element 2 of embodiment 2 configured in this manner has the same effect as the light source distribution element 2 of embodiment 1. In addition, light is collected and emitted by the convex first exit surface 22a formed on the surface of the lens 22B of the first exit portion 22, and light is collected and emitted by the second exit surface 23a of the lens 23B of the second exit portion 23. Therefore, the optical system of the headlight device arranged after the light source distribution element 2 can be made even smaller than the optical system of the headlight device arranged after the light source distribution element 2 of embodiment 1.

[0056] Embodiment 3 A light-source distribution element 2 according to the third embodiment will be described with reference to FIGS. The light source distribution element 2 of embodiment 3 differs from the light source distribution element 2 of embodiment 1 in that it is arranged on the Y axis relative to the light source 1, whereas the light source distribution element 2 of embodiment 1 is arranged on the Z axis relative to the light source 1. As a result, the first exit portion 22 and the second exit portion 23 respectively have a first optical path change portion 22C and a second optical path change portion 23C for changing the optical path in the + direction of the Z axis, but are otherwise the same. In addition, in Figs. 8 to 11, the same reference numerals as those shown in Figs. 1 to 4 indicate the same or corresponding parts.

[0057] The following mainly describes the differences between the light-source distribution element 2 according to the third embodiment and the light-source distribution element 2 according to the first embodiment. The light source 1 is disposed on the negative side of the Y axis of the light source distribution element 2, and emits light in the positive direction of the Y axis, that is, upward in the vertical direction. The optical axis of the light source 1 is along the Y axis and coincides with the optical axis of the light collection optical system 100. In the light-source distribution element 2 according to the third embodiment, one direction is the front-rear direction, that is, the Z-axis direction, and the other direction is the left-right direction, that is, the X-direction.

[0058] The light source distribution element 2 is disposed on the + side of the Y axis of the light source 1, and collects the light emitted from the light source 1 incident on the incident surface 21a of the lens 21B with a small divergence angle, and guides the light, ideally parallel light, along the Y axis, i.e., in the vertical direction, to the first bonding surface 21b and the second bonding surface 21c via the base 21A. The first joint surface 21b and the second joint surface 21c are positioned along one direction, that is, the front-rear direction.

[0059] First emission section 22 has first emission surface 22a located on the front side in the front-rear direction, and has third reflection surface 22c that reflects light guided to first light guiding section 24 and guides the light to first emission surface 22a. The first emission section 22 has a rectangular parallelepiped base 22A having a third bonding surface 22b which is a bonding surface with the first light-guiding section 24, and a first optical path changing section 22C which is integrally formed with the base 22A on a surface opposite to the third bonding surface 22b, has a first emission surface 22a on its front surface, and has a third reflecting surface 22c formed on its upper surface. The third bonding surface 22b is parallel to the first bonding surface 21b of the incident portion 21 and has the same shape.

[0060] The first optical path changing section 22C has a slope inclined at 45 degrees with respect to the surface facing the third bonding surface 22b, and a third reflecting surface 22c is formed on the slope. On the front surface, the area between the slope and the surface facing the third bonding surface 22b forms the first exit surface 22a. That is, the light guided to the surface opposite to the third bonding surface 22b is totally reflected by the third reflecting surface 22c, and its optical path is changed by 90 degrees, as shown in Figures 9 to 11, and is emitted forward in the front-to-back direction from the first exit surface 22a.

[0061] The third reflecting surface 22c may be a reflecting surface having a light collecting function, in which case the third reflecting surface 22c has a positive power. In this way, by providing the third reflecting surface 22c with a light collecting function, it is possible to easily form a complex light distribution required for a headlamp device. Furthermore, the third reflecting surface 22c may be an assembly of a plurality of reflecting surfaces each having a light collecting function, in which case the third reflecting surface 22c may have a positive power as a whole.

[0062] Second exit section 23 has second exit surface 23a located on the front side in the front-rear direction, and has fourth reflecting surface 23c that reflects the light guided to second light guiding section 25 and guides it to second exit surface 23a. The second exit section 23 has a rectangular parallelepiped base 23A having a fourth bonding surface 23b which is a bonding surface with the second light-guiding section 25, and a second optical path changing section 23C which is integrally formed with base 23A on the surface opposite to fourth bonding surface 23b, has a second exit surface 23a on its front surface, and has a fourth reflecting surface 23c formed on its upper surface.

[0063] The fourth bonding surface 23b is parallel to the second bonding surface 21c of the incident portion 21 and has the same shape. The second exit surface 23a emits light in one direction, i.e., the front-to-back direction, from the first exit surface 22a of the first exit section 22, and in another direction perpendicular to the one direction in a plane perpendicular to the optical axis of the light source 1, i.e., in the left-to-right direction, at a different position. The left rear side of first emission portion 22 and the right front side of second emission portion 23 are in contact with each other, and the left rear corner of first emission surface 22a and the right front corner of second emission surface 23a coincide with each other. It is not necessary that the rear left corner of first exit surface 22a and the front right corner of second exit surface 23a coincide with each other.

[0064] The second optical path changing section 23C has an inclined surface inclined at 45 degrees with respect to the surface opposite the fourth bonding surface 23b, and a fourth reflecting surface 23c is formed on the inclined surface, and on the front surface, the area between the inclined surface and the surface opposite the fourth bonding surface 23b forms the second exit surface 23a. That is, the light guided to the surface opposite to the fourth bonding surface 23b is totally reflected by the fourth reflecting surface 23c, as shown in Figures 9 to 11, and its optical path is changed by 90 degrees, and is emitted forward in the front-to-back direction from the second exit surface 23a.

[0065] The fourth reflecting surface 23c may be a reflecting surface having a light collecting function, in which case the fourth reflecting surface 23c has a positive power. In this way, by providing the fourth reflecting surface 23c with a light collecting function, it is possible to easily form a complex light distribution required for a headlamp device. Furthermore, the fourth reflecting surface 23c may be an assembly of a plurality of reflecting surfaces each having a light collecting function, in which case the fourth reflecting surface 23c may have a positive power as a whole.

[0066] When the third reflecting surface 22c and the fourth reflecting surface 23c have a light collecting function, it is preferable that the third reflecting surface 22c and the fourth reflecting surface 23c have different light collecting powers. Since the third reflecting surface 22c and the fourth reflecting surface 23c have different light collecting powers, the first exit portion 22 and the second exit portion 23 emit light having different light distributions. Therefore, the complex light distribution required for the headlamp device can be easily formed with a higher degree of freedom by the composite light distribution of the first emission portion 22 and the second emission portion 23. At least one of the third reflecting surface 22c and the fourth reflecting surface 23c may be a reflecting surface having a light collecting function.

[0067] The first exit section 22 and the second exit section 23 are integrally formed from a transparent material as the light source distribution element 2, and the surface opposite the third bonding surface 22b and the surface opposite the fourth bonding surface 23b are not physically existing surfaces but are virtual surfaces, and the first exit surface 22a and the second exit surface 23a may be physical exit surfaces or may be virtual exit surfaces.

[0068] The first light guiding section 24 is located between the first bonding surface 21b of the incident section 21 and the third bonding surface 22b of the first exit section 22, and guides the light from the first bonding surface 21b of the incident section to the first exit section 22. The first light guiding section 24 has a rectangular parallelepiped shape that linearly connects the first bonding surface 21b and the third bonding surface 22b, and the shape of the horizontal cross section that is the ZX plane is the same as the shape of the first bonding surface 21b and the third bonding surface 22b.

[0069] The light guided from the first joint surface 21b of the incident portion 21 to the first light guiding portion 24, which is a portion of the light from the light source 1 that is incident on the incident surface 21a of the incident portion 21, travels straight parallel to the optical axis of the light source 1 as the first light L1, as shown by the two-dotted dashed arrows in Figures 8 to 11, is guided to the third joint surface 22b of the first exit portion 22, is totally reflected at a right angle by the third reflecting surface 22c, and is emitted forward from the first exit surface 22a as parallel light that is bent at a right angle to the optical axis of the light source 1.

[0070] The second light-guiding section 25 is located between the second bonding surface 21c of the incident section 21 and the fourth bonding surface 23b of the second exit section 23, and has a first reflecting surface 25a formed on the right side of the opposing side surface in the other direction, i.e., the left-right direction, and a second reflecting surface 25b formed on the left side of the opposing side surface in the left-right direction, and the first reflecting surface 25a and the second reflecting surface 25b reflect light from the second bonding surface 21c of the incident section 21 and guide it to the second exit section 23.

[0071] The second light-guiding section 25 has a rectangular shape that connects the second bonding surface 21c and the fourth bonding surface 23b in a straight line inclined at 45 degrees to the left and right with respect to the optical axis of the light source 1, in this example, to the left, and the shape of the horizontal cross section, which is the ZX plane, is the same shape as the second bonding surface 21c and the fourth bonding surface 23b. The right and left side surfaces of second light guiding section 25 are inclined at 45 degrees to the left, and are parallel to each other.

[0072] The second light-guiding section 25 has a first bent portion that bends in the other direction, in this example, to the left, and a second bent portion that bends in the opposite direction to the first bent portion, the first bent portion being at the second bonding surface 21c of the incident section 21, and the second bent portion being the fourth bonding surface 23b of the second exit section 23.

[0073] The light guided from the second joint surface 21c of the incident portion 21 to the second light guiding portion 25, which is another part of the light from the light source 1 incident on the incident surface 21a of the incident portion 21, travels straight parallel to the optical axis of the light source 1 as second light L2, as shown by dotted arrows in Figures 8 to 11, and the light that reaches the first reflecting surface 25a is totally reflected at a right angle by the first reflecting surface 25a.

[0074] The light that is totally reflected by first reflecting surface 25a and reaches second reflecting surface 25b is totally reflected at a right angle by second reflecting surface 25b and is guided to fourth bonding surface 23b of second emission part 23. The light guided to the fourth bonding surface 23b is totally reflected by the fourth reflecting surface 23c, and is emitted forward from the second emission surface 23a as parallel light that is bent at a right angle to the optical axis of the light source 1.

[0075] The light source distribution element 2 of embodiment 3 configured as described above guides light from the light source 1 into the inside of the entrance portion 21 by using the entrance surface 21a of the entrance portion 21 to reduce the divergence angle of the light, and uses two light guiding portions, the first light guiding portion 24 and the second light guiding portion 25, to branch the incident light beam incident on the entrance portion 21 into two in the front-to-rear direction, and the branched incident light beam is totally reflected by the third reflecting surface 22c of the first exit portion 22 and the fourth reflecting surface 23c of the second exit portion 23, and emits the branched light beam forward from the first exit surface 22a and the second exit surface 23a as parallel light beams bent at a right angle to the optical axis of the light source 1.

[0076] As with the light source distribution element 2 of embodiment 1, the light source distribution element 2 of embodiment 3 is set so that the product of the vertical length h1 of the first exit surface 22a of the first emission section 22 and the vertical divergence angle θ1 of the light emitted from the first exit surface 22a is smaller than the product of the front-to-rear length h0 of the light source 1 and the front-to-rear divergence angle θ0 of the light from the light source 1. That is, it is set so as to satisfy the formula (1).

[0077] In addition, the product of the vertical length h2 of the second exit surface 23a of the second exit section 23 and the vertical divergence angle θ2 of the light emitted from the second exit surface 23a is set to a value smaller than the product of the front-to-rear length h0 of the light source 1 and the front-to-rear divergence angle θ0 of the light from the light source 1. That is, it is set so as to satisfy the following formula (4).

[0078] The light-source distribution element 2 according to the third embodiment configured in this manner can be made smaller in size without reducing the light utilization efficiency by simplifying the structure, similar to the light-source distribution element 2 according to the first embodiment. Furthermore, the branched incident light beam is totally reflected by the third reflecting surface 22c of the first exit portion 22 and the fourth reflecting surface 23c of the second exit portion 23, and the branched light beam is emitted forward from the first exit surface 22a and the second exit surface 23a as a parallel light beam bent at a right angle to the optical axis of the light source 1, so that the position at which the light is extracted from the light source distribution element 2 can be easily adjusted.

[0079] In other words, in the light source distribution element 2 of embodiment 3, the vertical height of the light emitted from the first exit surface 22a of the first exit portion 22 and the light emitted from the second exit surface 23a of the second exit portion 23 are the same, but by changing the vertical length of the base 22A of the first exit portion 22 and the vertical length of the base 23A of the second exit portion 23, the vertical height of the light emitted from the first exit surface 22a and the light emitted from the second exit surface 23a can be changed, which allows for free design of the headlight device and, as a result, improves the design of the headlight device.

[0080] Furthermore, by making the third reflecting surface 22c of the first exit portion 22 and the fourth reflecting surface 23c of the second exit portion 23 reflecting surfaces having a light-collecting function, it is possible to easily form the complex light distribution required for a headlight device. Furthermore, by making the third reflecting surface 22c and the fourth reflecting surface 23c reflecting surfaces having different light collecting powers, the complex light distribution required for the headlamp device can be formed more freely and easily by the composite light distribution of the first exit portion 22 and the second exit portion 23.

[0081] In addition, as shown in the light source distribution element 2 of embodiment 2, the light source distribution element 2 of embodiment 3 may be configured such that the first exit surface 22a in the first optical path changing section 22C as the first exit section 22 is a lens 22B having a first exit surface 22a of a convex shape having positive refractive power at least in a portion thereof on its surface, and the second exit surface 23a in the second optical path changing section 23C as the second exit section 23 is a lens 23B having a second exit surface 23a of a convex shape having positive refractive power at least in a portion thereof on its surface.

[0082] Embodiment 4 A headlamp device according to a fourth embodiment will be described with reference to FIG. In FIG. 12, the same reference numerals as those shown in FIGS. 6 and 7 indicate the same or corresponding parts. The headlamp device according to the fourth embodiment is a low beam headlamp device for a motorcycle. When applied to a low beam automobile headlamp device, a plurality of headlamp devices shown in the fourth embodiment may be arranged in parallel in the left-right direction as one element of the automobile headlamp device. In this case, the shade 3 and the projection lens 4 may each be formed integrally with the plurality of elements.

[0083] The headlamp device according to the fourth embodiment includes a light source 1, a light source distribution element 2, a shade 3, and a projection lens 4. The light collecting optical system 100 having the light source 1 and the light source distribution element 2 is the light collecting optical system 100 including the light source distribution element 2 according to the second embodiment. However, the light collecting optical system 100 may include the light-source distribution element 2 according to the third embodiment, in which the first emission section 22 has the lens 22B and the second emission section 23 has the lens 23B.

[0084] The shade 3 is disposed at a light collecting position of the light-source distribution element 2 and forms a cut-off line for the light emitted from the light-source distribution element 2. That is, the shade 3 blocks a portion of the light emitted from the light-source distribution element 2 so 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.

[0085] The projection lens 4 receives the light, part of which has been blocked by the shade 3, and emits the transmitted light having a light distribution pattern in which a cutoff line is formed forward as low beam irradiation light. The projection lens 4 is located in an inverse relationship to the position of the light source distribution element 2 relative to the shade 3 ; that is, the shade 3 is located at the focal position of the projection lens 4 .

[0086] In the headlight device of embodiment 4 configured as described above, the light source distribution element 2, to which light from the light source 1 is incident on the incident surface 21a, reduces the divergence angle of the light by the incident surface 21a, and utilizes the two light guiding sections, the first light guiding section 24 and the second light guiding section 25, to focus each of the parallel incident light beams branched into two by the first exit surface 22a of the first exit section 22 and the second exit surface 23a of the second exit section 23, and emits them to the shade 3.

[0087] The shade 3 partially blocks the light collected by each of the first exit surface 22a and the second exit surface 23a, and the projection lens 4 emits the light partially blocked by the shade 3 forward as low beam irradiation light with a light distribution pattern in which a cutoff line is formed.

[0088] Therefore, the headlight device of embodiment 4 uses a focusing optical system 100 including the light source distribution element 2 of embodiment 2, which has a simple structure and can be made compact without reducing light utilization efficiency, and therefore the projection lens 4 can be shortened in the vertical direction, and the headlight device of embodiment 4 has a thin optical system, which can flexibly respond to design and aesthetic needs.

[0089] Embodiment 5. A headlamp module according to a fifth embodiment will be described with reference to FIG. In FIG. 13, the same reference numerals as those shown in FIGS. 8 to 11 indicate the same or corresponding parts. The headlight module according to the fifth embodiment is applied to a low beam in a headlight device for a motorcycle. When applied to a low beam automobile headlamp device, a plurality of headlamp modules shown in the fifth embodiment may be arranged in parallel in the left-right direction as one element of the automobile headlamp device.

[0090] The headlight module of embodiment 5 is configured by integrally forming a first cutoff line forming section 26, a second cutoff line forming section 27, a first projection lens 28, and a second projection lens 29 on the light source distribution element 2 of embodiment 3.

[0091] The first cutoff line forming portion 26 is integrally formed extending forward in the front-to-rear direction from the first exit surface 22a of the first exit portion 22 of the light source distribution element 2, and has a fifth reflecting surface 26a on its lower surface in the up-down direction that reflects light emitted from the first exit surface 22a and emits light on which a cutoff line has been formed.

[0092] The first cutoff line forming portion 26 has a first area 26A and a second area 26B. One end face of the first region 26A is a joint surface with the first exit surface 22a of the first exit section 22, the lower surface is located on the ZX plane, i.e., the horizontal plane, the upper surface is a surface that is inclined downward relative to the horizontal plane, and the right and left sides are located on the same plane as the right and left sides, respectively, of the first light-guiding section 24.

[0093] The third reflecting surface 22c of the first emission unit 22 totally reflects the light guided from the third bonding surface 22b, and condenses and guides the light from the first emission surface 22a to the fifth reflecting surface 26a of the first cutoff line forming unit 26. The third reflecting surface 22c is formed at an inclination of less than 45 degrees with respect to the third bonding surface 22b, which is a horizontal plane. The third reflecting surface 22c may be a reflecting surface having a light collecting function similar to the light-source distribution element 2 according to the third embodiment.

[0094] The second area 26B has one end surface which is a joint surface with the other end surface of the first area 26A, extends integrally forward from the first area 26A, has upper and lower surfaces which lie in a horizontal plane, and has right and left sides which lie on the same plane as the right and left sides of the first area 26A, respectively. The second region 26B guides light having a cutoff line that is emitted from the first emission surface 22a and reflected by the fifth reflection surface 26a to the other end surface.

[0095] An underline on the joint surface between the first area portion 26A and the second area portion 26B, that is, the front end of the fifth reflecting surface 26a, is a ridge line 26b for forming the cutoff line. The ridge line 26b is located above the cutoff line, that is, the outside of the light distribution pattern is dark, and below the cutoff line, that is, the inside of the light distribution pattern is bright, and the fifth reflecting surface 26a reflects the incident light.

[0096] The second cutoff line forming portion 27 has a first area 27A and a second area 27B. One end face of the first region 27A is a joint surface with the second exit surface 23a of the second exit section 23, the lower surface is located on the ZX plane, i.e., the horizontal plane, the upper surface is a surface that is inclined downward relative to the horizontal plane, and the right and left sides are located on the same plane as the right and left sides of the second light-guiding section 25, respectively.

[0097] The fourth reflecting surface 23c of the second emission part 23 totally reflects the light guided from the fourth bonding surface 23b, and condenses and guides the light from the second emission surface 23a to the sixth reflecting surface 27a. The fourth reflecting surface 23c is formed at an angle of less than 45 degrees with respect to the fourth bonding surface 23b, which is a horizontal plane. The fourth reflecting surface 23c may be a reflecting surface having a light collecting function similarly to the light-source distribution element 2 according to the third embodiment.

[0098] The vertical length of the base 23A of the second emission section 23 is longer than the vertical length of the base 22A of the first emission section 22, and the height of the second emission surface 23a of the second emission section 23 is higher than the height of the first emission surface 22a of the first emission section 22.

[0099] The second area 27B has one end surface which is a joint surface with the other end surface of the first area 27A, extends integrally forward from the first area 27A, has upper and lower surfaces which lie in a horizontal plane, and has right and left sides which lie on the same plane as the right and left sides of the first area 27A. The second region 27B guides light having a cutoff line that is emitted from the second emission surface 23a and reflected by the sixth reflection surface 27a to the other end surface.

[0100] An underline on the joint surface between the first area 27A and the second area 27B, that is, the front end of the sixth reflecting surface 27a, is a ridge 27b for forming the cutoff line. The ridge line 27b is located above the cutoff line, i.e., the outside of the light distribution pattern is dark, and below the cutoff line, i.e., the inside of the light distribution pattern is bright, and the sixth reflecting surface 27a reflects the incident light.

[0101] The first projection lens 28 is a convex lens whose rectangular or circular flat surface is a joint surface with the other end surface of the second region portion 26B and whose surface has a convex exit surface. The first projection lens 28 emits the light beam reflected by the fifth reflecting surface 26a forward as low-beam irradiation light, which is light of a light distribution pattern having a cut-off line. The focal position of the first projection lens 28 is located on the ridge line 26b.

[0102] The second projection lens 29 is a convex lens whose rectangular or circular flat surface is a joint surface with the other end surface of the second region portion 27B and whose surface has a convex exit surface. The second projection lens 29 emits the light beam reflected by the sixth reflecting surface 27a forward as low-beam irradiation light, which is light of a light distribution pattern having a cut-off line. The focal position of the second projection lens 29 is located on the ridge line 27b.

[0103] The first cutoff line forming portion 26, the second cutoff line forming portion 27, the first projection lens 28, and the second projection lens 29 are integrally formed with the light-source distribution element 2 by using a transparent material.

[0104] The first exit surface 22a of the first exit section 22, one end face and the other end face of the first area 26A and one end face and the other end face of the second area 26B in the first cutoff line forming section 26, the flat surface of the first projection lens 28, the second exit surface 23a of the second exit section 23, one end face and the other end face of the first area 27A and one end face and the other end face of the second area 27B in the second cutoff line forming section 27, and the flat surface of the second projection lens 29 are not physically existing surfaces but are virtual surfaces.

[0105] In the headlight module of embodiment 5 configured as described above, the light source distribution element 2, to which light from the light source 1 is incident on the incident surface 21a, reduces the divergence angle of the light by the incident surface 21a, and utilizes the two light guiding sections, the first light guiding section 24 and the second light guiding section 25, to guide each of the parallel incident light beams branched into two parts from the first exit section 22 and the second exit section 23 to the first cutoff line forming section 26 and the second cutoff line forming section 27.

[0106] The first cutoff line forming section 26 and the first projection lens 28, as well as the second cutoff line forming section 27 and the second projection lens 29, each emit the light emitted from the first exit surface 22a of the first exit section 22 and the second exit surface 23a of the second exit section 23, respectively, forward as low beam irradiation light, which is light of a light distribution pattern having a cutoff line.

[0107] Therefore, the headlight module of embodiment 5 uses the light source distribution element 2 of embodiment 3 which has a simple structure and can be made compact without reducing light utilization efficiency, and the first cutoff line forming section 26 and the first projection lens 28, as well as the second cutoff line forming section 27 and the second projection lens 29 are integrally configured with the light source distribution element 2, thereby forming an optical system for low beam irradiation which is resistant to variations in placement accuracy, easy to handle, and has a simple structure that can be made compact without reducing light utilization efficiency.

[0108] Moreover, the underline at the joint surface between the first area portion 26A and the second area portion 26B, i.e., the front end of the fifth reflecting surface 26a, is used as the ridge line 26b for forming the cutoff line, and the underline at the joint surface between the first area portion 27A and the second area portion 27B, i.e., the front end of the sixth reflecting surface 27a, is used as the ridge line 27b for forming the cutoff line. Therefore, depending on the shapes of the ridge line 26b and the ridge line 27b, a light distribution pattern having an arbitrary and desired cutoff shape can be projected from the headlight module of embodiment 5.

[0109] Although the headlight module of embodiment 5 has the first projection lens 28 and the second projection lens 29, the first projection lens 28 and the second projection lens 29 do not have to be integrally formed in the headlight module.

[0110] That is, light may be emitted from a flat surface that is the other end face of the second region 26B in the first cutoff line forming portion 26 and a flat surface that is the other end face of the second region 26B in the second cutoff line forming portion 27. Moreover, the first projection lens 28 and the second projection lens 29 may be concave lenses having a concave exit surface on the surface. By making the emission surface flat or concave in this manner, it is possible to irradiate the light forward with a diffused light distribution.

[0111] In the description of the first to fifth embodiments, terms indicating the positional relationship between parts or the shape of parts, such as "parallel" and "perpendicular", include a range that takes into account manufacturing tolerances and assembly variations.

[0112] 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]

[0113] The light source distribution element for a headlamp device, the headlamp device, and the headlamp module according to the present disclosure are suitable for use in motorcycle and automobile headlights, particularly in low beam headlights. [Explanation of symbols]

[0114] 100 Light collecting optical system, 1 Light source, 2 Light source distribution element, 21 Incident portion, 21A Base portion, 21B Lens, 21a Incident surface, 21b First bonding surface, 21c Second bonding surface, 21A Base portion, 21B Lens, 22 First exit portion, 22a First exit surface, 22b Third bonding surface, 22c Third reflecting surface, 22A Base portion, 22B Lens, 22C First optical path changing section , 23 second exit portion, 23a second exit surface, 23b fourth bonding surface, 23c fourth reflecting surface, 23A base, 23B lens, 23C second optical path changing portion, 24 first light guiding portion, 25 second light guiding portion, 25a first reflecting surface, 25b second reflecting surface, 26 first cutoff line forming portion, 26a fifth reflecting surface, 27 second cutoff line forming portion, 27a sixth reflecting surface, 28 first projection lens, 29 second projection lens, 3 shade, 4 projection lens.

Claims

1. an incidence section having an incidence surface to which light from a light source is incident, the incidence section having a first bonding surface and a second bonding surface positioned along one direction in a plane perpendicular to an optical axis of the light source; a first emission section having a first emission surface that emits light; a second emission section having a second emission surface that emits light located at a different position in another direction perpendicular to the one direction on a plane perpendicular to the first emission surface of the first emission section and the one direction and an optical axis of the light source; a first light guiding portion located between a first bonding surface of the incident portion and the first exit portion, the first light guiding portion guiding light from the first bonding surface of the incident portion to the first exit portion; a second light guiding section that is located between the second bonding surface of the incident section and the second exit section, the second light guiding section having a first reflecting surface formed on one of the side surfaces facing in the other direction and a second reflecting surface formed on the other of the side surfaces facing in the other direction, and that guides light from the second bonding surface of the incident section to the second exit section by being reflected by the first reflecting surface and the second reflecting surface; Equipped with When the length in one direction of the light source is h0, the divergence angle of the light in one direction at the incident surface of the incident portion is θ0, the length in one direction at the first exit surface of the first exit portion is h1, the divergence angle of the light in one direction at the first exit surface of the first exit portion is θ1, the length in one direction at the second exit surface of the second exit portion is h2, and the divergence angle of the light in one direction at the second exit surface of the second exit portion is θ2, the relationships of h0×sinθ0>h1×sinθ1 and h0×sinθ0>h2×sinθ2 are satisfied, Each of the first exit surface of the first exit portion and the second exit surface of the second exit portion has a convex lens having refractive power on at least a part of the surface. A light source distribution element for a headlamp device.

2. an incidence section having an incidence surface to which light from a light source is incident, the incidence section having a first bonding surface and a second bonding surface positioned along one direction in a plane perpendicular to an optical axis of the light source; a first emission section having a first emission surface that emits light; a second emission section having a second emission surface that emits light located at a different position in another direction perpendicular to the one direction on a plane perpendicular to the first emission surface of the first emission section and the one direction and an optical axis of the light source; a first light guiding portion located between a first bonding surface of the incident portion and the first exit portion, the first light guiding portion guiding light from the first bonding surface of the incident portion to the first exit portion; a second light guiding section that is located between the second bonding surface of the incident section and the second exit section, the second light guiding section having a first reflecting surface formed on one of the side surfaces facing in the other direction and a second reflecting surface formed on the other of the side surfaces facing in the other direction, and that guides light from the second bonding surface of the incident section to the second exit section by being reflected by the first reflecting surface and the second reflecting surface; Equipped with The one direction is a front-rear direction, and the other direction is a left-right direction, a first exit surface of the first exit portion is located on a front surface in the front-rear direction, and the first exit portion has a third reflecting surface that reflects the light guided to the first light guiding portion and guides the light to the first exit surface, a second exit surface of the second exit portion is located on a front surface in the front-rear direction, and the second exit portion has a fourth reflecting surface that reflects the light guided to the second light guiding portion and guides the light to the second exit surface, The third reflecting surface is a collection of a plurality of reflecting surfaces having a light collecting function. A light source distribution element for a headlamp device.

3. an incidence section having an incidence surface to which light from a light source is incident, the incidence section having a first bonding surface and a second bonding surface positioned along one direction in a plane perpendicular to an optical axis of the light source; a first emission section having a first emission surface that emits light; a second emission section having a second emission surface that emits light located at a different position in another direction perpendicular to the one direction on a plane perpendicular to the first emission surface of the first emission section and the one direction and an optical axis of the light source; a first light guiding portion located between a first bonding surface of the incident portion and the first exit portion, the first light guiding portion guiding light from the first bonding surface of the incident portion to the first exit portion; a second light guiding section that is located between the second bonding surface of the incident section and the second exit section, the second light guiding section having a first reflecting surface formed on one of the side surfaces facing in the other direction and a second reflecting surface formed on the other of the side surfaces facing in the other direction, and that guides light from the second bonding surface of the incident section to the second exit section by being reflected by the first reflecting surface and the second reflecting surface; Equipped with The one direction is a front-rear direction, and the other direction is a left-right direction, a first exit surface of the first exit portion is located on a front surface in the front-rear direction, and the first exit portion has a third reflecting surface that reflects the light guided to the first light guiding portion and guides the light to the first exit surface, a second exit surface of the second exit portion is located on a front surface in the front-rear direction, and the second exit portion has a fourth reflecting surface that reflects the light guided to the second light guiding portion and guides the light to the second exit surface, The fourth reflecting surface is a collection of a plurality of reflecting surfaces having a light collecting function. A light source distribution element for a headlamp device.

4. 3. The light source distribution element for a headlamp device according to claim 2, wherein the fourth reflecting surface is an assembly of a plurality of reflecting surfaces each having a light collecting function.

5. 5. The light source distribution element for a headlamp device according to claim 1, wherein the entrance portion, the first exit portion, the second exit portion, the first light guiding portion, and the second light guiding portion are integrally formed from a transparent material.

6. the first light guiding portion is formed linearly between a first joint surface of the incident portion and the first emission portion, the second light guiding section has, between a first joint surface of the incident section and the first emission section, a first bent section bent in the other direction and a second bent section bent in a direction opposite to the first bent section; The light source distribution element for a headlamp device according to any one of claims 1 to 5.

7. The light-source distribution element for a headlamp device according to claim 1 , wherein the incident portion condenses incident light and guides parallel light to the first joint surface and the second joint surface.

8. 8. The light source distribution element for a headlamp device according to claim 1, wherein an entrance surface of the entrance portion has a positive refractive power and a convex shape that reduces a divergence angle of light incident on the entrance surface.

9. A light source distribution element for a headlamp device according to any one of claims 1 to 8, a shade that is disposed at a light collecting position of the light source distribution element for the headlamp device and forms a cutoff line for light emitted from the light source distribution element for the headlamp device; a projection lens that projects light having a cutoff line formed by the shade; Equipped with headlight device.

10. A light source distribution element for a headlamp device according to any one of claims 1 to 8, a first cutoff line forming portion that is integrally formed with a first emission surface of the headlamp device light source distribution element and that emits light having a cutoff line formed therein with respect to light emitted from the first emission surface; a second cutoff line forming portion that is integrally formed with a second emission surface of the headlamp device light source distribution element and that emits light having a cutoff line formed therein with respect to light emitted from the second emission surface; Equipped with a headlamp module.

11. A light source distribution element for a headlamp device according to any one of claims 2 to 4, a first cutoff line forming portion that is integrally formed so as to extend in the front-rear direction from a first emission surface of the headlamp device light source distribution element, and has a fifth reflecting surface on a lower surface in a vertical direction along an optical axis of the light source, the fifth reflecting surface reflecting the light emitted from the first emission surface and emitting light on which a cutoff line is formed; a second cutoff line forming portion that is integrally formed so as to extend in the front-rear direction from the second emission surface of the headlamp device light source distribution element, and has a sixth reflecting surface on a lower surface in the up-down direction, the sixth reflecting surface reflecting the light emitted from the second emission surface and emitting light on which a cutoff line is formed; Equipped with a headlamp module.

12. the first cutoff line forming unit has a first projection lens integrally formed at a tip thereof, the second cutoff line forming unit has a second projection lens integrally formed at a tip thereof; 12. A headlamp module according to claim 11.

Images