Optical components, light source units, and vehicle lighting fixtures

Abstract

The present invention provides an optical component, a light source unit, and a vehicle lighting fixture that can emit light with uniform brightness even when the light-emitting surface is enlarged. [Solution] An optical member that guides light incident from a light incident part through a light guide part and emits it from a light emission part, wherein the light guide part has an incident side light guide plate part provided with a light incident part, and an emission side light guide plate part provided extending in a direction intersecting the extension direction of the incident side light guide plate part, the emission side light guide plate part is provided with a direction changing reflecting part for reflecting the light guided from the incident side light guide plate part and guiding it within the emission side light guide plate part, the incident side light guide plate part is provided with a light reflecting recess at a position corresponding to the light incident part, the light reflecting recess has an emission side reflecting surface that reflects a part of the light toward the emission side light guide plate part, and an opposite side reflecting surface that reflects the other part of the light toward the opposite side of the emission side light guide plate part, and the emission side reflecting surface and the opposite side reflecting surface are separated by a reflection separation part.

Description

Technical Field

[0001] The present invention relates to an optical member, a light source unit, and a vehicular lamp.

Background Art

[0002] As a vehicular lamp, there has been proposed a device that causes light from a semiconductor light emitting element (LED: Light Emitting Diode) serving as a light source to enter a plate-shaped light guide member and irradiate the outside with light from an end portion of the light guide member (see, for example, Patent Documents 1 and 2). In such a vehicular lamp, the light from the LED, which is a point light source, can be emitted in the shape of the light emission surface of the light guide member, so that various designs can be expressed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of Invention

Problems to be Solved by the Invention

[0004] Further, in the technical field of vehicular lamps, there is also a demand for combining a plurality of segments each composed of a light guide member and a light source to express various designs with a light emission surface having a larger area. However, when a plurality of light guide members are combined, there is a problem that a luminance difference at the boundary position of each segment is easily visually recognized, and the design property is deteriorated. In addition, when the area of the light emission surface is increased, there is a problem that a luminance difference is likely to occur even inside the segment.

[0005] The present invention has been made in view of the above-described conventional problems, and an object thereof is to provide an optical member, a light source unit, and a vehicular lamp that can emit light with uniform luminance even when a light emission surface is made larger.

Means for Solving the Problems

[0006] To solve the above problems, the present invention provides an optical member that guides light incident from an incident light portion through a light guide portion and emits it from a light emission portion, wherein the light guide portion has an incident light guide plate portion on which the incident light portion is provided, and an emission light guide plate portion that extends in a direction intersecting the extension direction of the incident light guide plate portion, the emission light guide plate portion is provided with a direction-changing reflective portion for reflecting the light guided from the incident light guide plate portion and guiding it within the emission light guide plate portion, the incident light guide plate portion is provided with a light-reflecting recess at a position corresponding to the incident light portion, the light-reflecting recess has an emission-side reflective surface that reflects a part of the light toward the emission light guide plate portion, and an opposite-side reflective surface that reflects another part of the light toward the opposite direction from the emission light guide plate portion, and the emission-side reflective surface and the opposite-side reflective surface are separated by a reflection separation portion.

[0007] In the optical member of the present invention, the light-reflecting recess has an output-side reflective surface that reflects a portion of the light in the direction of the output-side light guide plate, and an opposite-side reflective surface that reflects the other portion of the light in the direction opposite to the output-side light guide plate. The output-side reflective surface and the opposite-side reflective surface are separated by a reflection separation section, so that even if the light output section is enlarged, light can be emitted with uniform brightness.

[0008] In another aspect of the present invention, the incident light guide plate portion has a light-reflecting end face on the side opposite to the output light guide plate portion, and the light-reflecting end face has a re-reflecting end face that reflects the light reflected by the opposite reflective surface, and a folded-back reflective end face that reflects the light reflected by the re-reflecting end face in the direction of the output light guide plate portion.

[0009] In another aspect of the present invention, the folded reflective end face has a Fresnel shape and reflects the light as substantially parallel light in the direction of the output side light guide plate.

[0010] Furthermore, in one aspect of the present invention, there is an intermediate reflective portion provided between the re-reflecting end surface and the folded-back reflective end surface, which reflects a portion of the light reflected by the re-reflecting end surface in the direction of the output-side light guide plate portion.

[0011] In another aspect of the present invention, the light-reflecting recess and the intermediate-reflecting portion are concave in shape and provided on the opposite side of the light incident portion, and are composed only of surfaces whose normal direction is in the range of 0 degrees to 90 degrees with respect to a predetermined direction.

[0012] In another aspect of the present invention, the direction-changing reflective portion has a Fresnel reflective portion to which the light reflected by the output-side reflective surface is incident and the light is reflected in the in-plane direction of the output-side light guide plate portion as substantially parallel light.

[0013] In another aspect of the present invention, the direction-changing reflective portion has a stepped reflective portion to which the light reflected by the opposite reflective surface is incident and the light is reflected in the in-plane direction of the output-side light guide plate portion.

[0014] In another aspect of the present invention, the direction-changing reflective portion diffuses and reflects the light in the thickness direction of the light-guiding plate portion on the output side.

[0015] Furthermore, in order to solve the above problems, the light source unit of the present invention is characterized by comprising an optical member described in any one of the above and a light source unit arranged opposite the light incident portion.

[0016] Furthermore, in order to solve the above problems, the vehicle lighting device of the present invention is characterized by arranging a plurality of the above-mentioned light source units. [Effects of the Invention]

[0017] The present invention provides an optical component, a light source unit, and a vehicle lighting device that can emit light with uniform brightness even when the light-emitting surface is enlarged. [Brief explanation of the drawing]

[0018] [Figure 1] Figure 1(a) is a schematic perspective view showing the structure of the optical member 100 according to the first embodiment, where the upper side is provided with the light incident portion 30 and the light emission portion 90, and Figure 1(b) is provided with the lower side is provided with the light reflection recess 40 and the intermediate reflection portion 60. [Figure 2] This is a schematic diagram showing light reflection at a light reflecting recess 40 in a light source unit 1 using the optical member 100. [Figure 3] This is a schematic diagram showing light reflection at a direction changing reflector 50 and the light path in an emission-side light guide plate portion 20 in the light source unit 1 using the optical member 100. [Figure 4] This is an enlarged schematic perspective view showing the vicinity of an incident-side light guide plate portion 10, where Fig. 4(a) shows the upper surface side provided with a light incident portion 30 and the direction changing reflector 50, and Fig. 4(b) shows the lower surface side provided with the light reflecting recess 40 and an intermediate reflector 60. [Figure 5] This is a transparent perspective view showing the positional relationship among the light incident portion 30, the direction changing reflector 50, the light reflecting recess 40, and the intermediate reflector 60. [Figure 6] This is a transparent top view showing the positional relationship among the light incident portion 30, the direction changing reflector 50, the light reflecting recess 40, and the intermediate reflector 60. [Figure 7] This is a schematic diagram for describing the path of light incident from the light incident portion 30. [Figure 8] This is an enlarged schematic perspective view showing the direction changing reflector 50. [Figure 9] This is a schematic top view showing the structure of an optical member 200 according to the second embodiment. [Modes for Carrying Out the Invention]

[0019] (First Embodiment) Embodiments of the present invention will be described in detail below with reference to the drawings. The same or equivalent components, members, and processes shown in each drawing will be denoted by the same reference numerals, and redundant explanations will be omitted as appropriate. Figure 1 is a schematic perspective view showing the structure of the optical member 100 according to this embodiment, where Figure 1(a) shows the upper side provided with the light incident portion 30 and the light emission portion 90, and Figure 1(b) shows the lower side provided with the light reflection recess 40 and the intermediate reflection portion 60. As shown in Figure 1, the optical member 100 comprises an incident light guide plate portion 10, an emission light guide plate portion 20, a light incident portion 30, a light reflection recess 40, a direction-changing reflection portion 50, an intermediate reflection portion 60, a re-reflection end face 70, a folded reflection end face 80, and a light emission portion 90.

[0020] The optical component 100 is made of a light-transmitting material and guides light incident from the light incident section 30 through the light guide section and emits it from the light emission section 90. At each part of the optical component 100, light incident at an angle greater than the critical angle at the interface with air is totally reflected due to the refractive index of the material constituting the optical component 100. Each part constituting the optical component 100 is formed by integral molding of a resin material. The optical component 100 is combined with a light source section 120 that emits light as described later to form a light source unit 1, and a vehicle light fixture is formed by arranging multiple light source units 1.

[0021] The incident light guide plate portion 10 constitutes a part of the light guide portion of the optical member 100 and is a plate-shaped portion that guides light to the exit light guide plate portion 20. The incident light guide plate portion 10 has a light incident portion 30 on its upper surface and a light reflection recess 40 and an intermediate reflection portion 60 on its lower surface. The exit light guide plate portion 20 is provided at one end of the incident light guide plate portion 10, and a re-reflection end surface 70 and a folded reflection end surface 80 are provided at the end opposite to the exit light guide plate portion 20.

[0022] The exit-side light guide plate portion 20 constitutes a part of the light guide portion of the optical member 100 and is a plate-shaped portion that guides light arriving from the incident-side light guide plate portion 10. The exit-side light guide plate portion 20 is provided extending in a direction intersecting the extending direction of the incident-side light guide plate portion 10 and is provided bent from the incident-side light guide plate portion 10. The exit-side light guide plate portion 20 is provided with a direction-changing reflecting portion 50 and a light-emitting portion 90 on one surface (front side). A scattering reflecting portion (not shown) for extracting light may be provided on the surface of the exit-side light guide plate portion 20 facing the light-emitting portion 90 (back side). The combination of the incident-side light guide plate portion 10 and the exit-side light guide plate portion 20 constitutes the light guide portion in the present invention.

[0023] The light incident section 30 is provided protruding from the upper surface of the incident-side light guide plate section 10, and is the part into which light emitted from the light source section 120, which will be described later, is incident. The shape of the light incident section 30 is not limited, but a frustoconical shape centered on the optical axis of the light from the light source section 120 can be used. Furthermore, the position in which the light incident section 30 is provided is not limited, but it is preferable for it to be in the center in the width direction of the incident-side light guide plate section 10 in order to emit light uniformly. In addition, it is preferable for the light incident section 30 to be located at an intermediate position between the direction-changing reflection section 50 and the re-reflection end face 70.

[0024] The light-reflecting recess 40 is a concave shape provided on the back surface of the incident light guide plate portion 10, facing the light incident portion 30. The light-reflecting recess 40 has a curved reflective surface and reflects light incident from the light incident portion 30 toward the exit light guide plate portion 20 and toward the re-reflecting end face 70. Details of the light-reflecting recess 40 will be described later.

[0025] The direction-changing reflective section 50 is provided on the surface side of the output-side light guide plate section 20 and reflects the light guided from the input-side light guide plate section 10, guiding the light in a direction along the output-side light guide plate section 20. The position where the direction-changing reflective section 50 is provided is near the upper end of the output-side light guide plate section 20 and intersects with the extension direction of the input-side light guide plate section 10. Furthermore, the direction-changing reflective section 50 is provided in a region with a length along the extension direction of the output-side light guide plate section 20, corresponding to the thickness of the input-side light guide plate section 10. Details of the direction-changing reflective section 50 will be described later.

[0026] The intermediate reflective section 60 is provided on the back surface of the incident light guide plate section 10, between the re-reflecting end surface 70 and the folded-back reflective end surface 80, and has a concave shape that reflects a portion of the light reflected by the re-reflecting end surface 70 towards the exit light guide plate section 20. The intermediate reflective section 60 is formed to a depth less than the thickness of the incident light guide plate section 10 and does not reach the upper surface of the incident light guide plate section 10. As a result, only a portion of the light reflected by the re-reflecting end surface 70 is reflected by the intermediate reflective section 60, and the light that does not enter the intermediate reflective section 60 reaches the folded-back reflective end surface 80. Details of the intermediate reflective section 60 will be described later.

[0027] The re-reflecting end face 70 is the portion that reflects the light that has been reflected from the light-reflecting recess 40 towards the folded-back reflective end face 80. The re-reflecting end face 70 is provided in two separate regions in the center of the width direction of the incident-side light guide plate portion 10, and the reflection directions of each region are opposite in the width direction. Therefore, the light reflected by the light-reflecting recess 40 is reflected by the re-reflecting end face 70 and propagates in opposite directions toward both sides in the width direction. In Figure 1, the re-reflecting end face 70 is shown as a curved shape, but it may also be a Fresnel shape with a stepped shape created by dividing the curved surface into multiple regions.

[0028] The folded-back reflective end face 80 is the portion that reflects the light reflected by the re-reflecting end face 70 towards the exit-side light guide plate portion 20. Figure 1 shows an example in which a Fresnel shape is used as the folded-back reflective end face 80, by dividing the curved surface into multiple regions to create a stepped shape, and reflecting the light as substantially parallel light. This allows the light to be guided along both ends of the incident-side light guide plate portion 10 and the exit-side light guide plate portion 20, thereby achieving a uniform brightness distribution. The combination of the re-reflecting end face 70 and the folded-back reflective end face 80 constitutes the light-reflecting end face in this invention.

[0029] The light-emitting section 90 is located on the surface side of the light-emitting side light guide plate section 20 and is the surface that irradiates the light that has propagated within the light-emitting side light guide plate section 20 to the outside. In Figure 1, the light-emitting section 90 is shown as rectangular, but its shape is not limited. When multiple optical elements 100 are arranged, the light-emitting section 90 is used in combination with adjacent light-emitting sections 90 to express the design, and constitutes one segment in the entire vehicle lighting fixture that uses multiple light source units 1.

[0030] Figure 2 is a schematic diagram showing the reflection of light at the light-reflecting recess 40 in the light source unit 1 using the optical element 100. Figure 3 is a schematic diagram showing the reflection of light at the direction-changing reflecting section 50 and the path of light at the output-side light guide plate section 20 in the light source unit 1 using the optical element 100. As shown in Figures 2 and 3, the light source unit 1 includes the optical element 100, the circuit board 110, and the light source section 120.

[0031] The circuit board 110 has a light source unit 120 mounted on one side and is a board that supplies power and control signals to the light source unit 120. The circuit board 110 also has electronic components (not shown) that constitute the drive circuit for the light source unit 120 mounted on it. Furthermore, a wiring layer is provided on the surface or inside of the circuit board 110, electrically connecting the light source unit 120 and the electronic components. Although not shown in Figures 2 and 3, a heat dissipation member may be provided on the side of the circuit board 110 opposite to the side on which the light source unit 120 is mounted.

[0032] The light source unit 120 is a component that emits light of a predetermined wavelength when power is supplied to it, and one example is a semiconductor light-emitting element such as an LED. The light-emitting surface of the light source unit 120 is positioned opposite the light incident unit 30, and the light emitted by the light source unit 120 is taken into the incident-side light guide plate unit 10 from the light incident unit 30.

[0033] As shown in Figure 2, light incident from the light incident section 30 is reflected by the exit-side reflective surface 42 and the opposite-side reflective surface 41 of the light-reflecting recess 40, and propagates in the in-plane direction of the incident-side light guide plate section 10. Here, the light reflected by the opposite-side reflective surface 41 travels in the direction of the re-reflecting end surface 70, and the light reflected by the exit-side reflective surface 42 travels in the direction of the exit-side light guide plate section 20. Details of the opposite-side reflective surface 41 and the exit-side reflective surface 42 will be described later. The light reflected by the exit-side reflective surface 42 travels in the direction of the exit-side light guide plate section 20 within the plane of the incident-side light guide plate section 10, reaches the direction-changing reflective section 50 where it is reflected, and travels along the in-plane direction of the exit-side light guide plate section 20.

[0034] Furthermore, as shown in Figure 3, the light reflected by the direction-changing reflective section 50 is diffused in multiple directions along the thickness direction of the output-side light guide plate section 20. As a result, the path for light propagating in the in-plane direction of the output-side light guide plate section 20 is broadened when it is repeatedly reflected between the back surface 91 and the light output section 90, making the brightness distribution of the light extracted from the light output section 90 uniform. The structure for scattering light in the direction-changing reflective section 50 is not limited; a reflective surface with a fine curved shape may be used, or fine irregularities may be formed on the reflective surface.

[0035] Figure 4 is a schematic perspective view showing an enlarged view of the vicinity of the incident light guide plate 10. Figure 4(a) shows the upper side where the light incident section 30 and the direction-changing reflecting section 50 are provided, and Figure 4(b) shows the lower side where the light-reflecting recess 40 and the intermediate reflecting section 60 are provided. Figure 5 is a transmission perspective view showing the positional relationship of the light incident section 30, the direction-changing reflecting section 50, the light-reflecting recess 40, and the intermediate reflecting section 60. Figure 6 is a transmission top view showing the positional relationship of the light incident section 30, the direction-changing reflecting section 50, the light-reflecting recess 40, and the intermediate reflecting section 60.

[0036] As shown in Figures 4(a), 5, and 6, the light incident section 30 has an opposing surface 31 and a side surface 32, and the direction-changing reflective section 50 has a Fresnel reflective section 51 and a stepped reflective section 52. Also, as shown in Figures 4(b), 5, and 6, the light-reflecting recess 40 has an opposite reflective surface 41, an exit-side reflective surface 42, and a reflection separation section 43.

[0037] The opposing surface 31 is a surface provided on the upper surface of the light incident section 30 and facing the light source section 120. Preferably, the opposing surface 31 has a larger area than the irradiation range of light from the light source section 120. The shape of the opposing surface 31 is not limited and may be flat, concave, or convex. A side surface 32 is provided on the outer circumference of the opposing surface 31.

[0038] The side surface 32 is provided along the outer circumference of the opposing surface 31 and is erected from the upper surface of the incident light guide plate portion 10. Preferably, the side surface 32 is erected at an inclination with respect to the incident light guide plate portion 10, and preferably is composed of a smooth surface so as to reflect light at the interface between the side surface 32 and the air. This allows a portion of the light irradiated from the light source portion 120 that spreads laterally from the opposing surface 31 to be reflected by the side surface 32 and reach the light reflection recess 40. The shape of the side surface 32 is not limited and may be a slope with a constant inclination with respect to the incident light guide plate portion 10, or it may be part of a paraboloid or ellipsoid of revolution with the light source portion 120 as the focal point.

[0039] The opposite reflective surface 41 is provided in a fan shape in a plan view, centered on the vertex P of the light-reflecting recess 40, and is a reflective surface that reflects a portion of the light incident from the light incident section 30 in the opposite direction to the exit-side light guide plate section 20. Preferably, the area where the opposite reflective surface 41 is provided is wider than the region connecting the ends of the re-reflecting end surface 70 and the vertex P. The opposite reflective surface 41 has a curved surface that is inclined with respect to the back surface of the incident-side light guide plate section 10, and light that reaches the opposite reflective surface 41 is reflected by the curved surface and travels in the in-plane direction of the incident-side light guide plate section 10 to reach the re-reflecting end surface 70.

[0040] The curved shape of the opposite reflective surface 41 is not limited, but a part of a curved surface obtained by rotating a parabola or ellipse around the vertex P as the central axis can be used. In this case, it is preferable to position the light source unit 120 at the focal position of the rotated parabola or ellipsoid. By positioning the light source unit 120 at the focal position of the parabola or ellipsoid, the light reflected by the opposite reflective surface 41 travels through the inside of the incident light guide plate unit 10 as substantially parallel light, thereby improving the uniformity of light in the thickness direction.

[0041] The exit-side reflective surface 42 is provided in a fan shape in a plan view, centered on the vertex P of the light-reflecting recess 40, and is a reflective surface that reflects a portion of the light incident from the light incident section 30 toward the exit-side light guide plate section 20. Preferably, the area where the exit-side reflective surface 42 is provided is wider than the region connecting the ends of the Fresnel reflective section 51 and the vertex P. The exit-side reflective surface 42 has a curved surface that is inclined with respect to the back surface of the incident-side light guide plate section 10, and light that reaches the exit-side reflective surface 42 is reflected by the curved surface and travels in the in-plane direction of the incident-side light guide plate section 10 to reach the Fresnel reflective section 51.

[0042] The curved shape of the output-side reflecting surface 42 is not limited, but a part of a curved surface obtained by rotating a parabola or ellipse around the vertex P as the central axis can be used. In this case, it is preferable to position the light source unit 120 at the focal position of the rotated parabola or ellipse. By positioning the light source unit 120 at the focal position of the parabola or ellipse, the light reflected by the output-side reflecting surface 42 travels through the inside of the incident-side light guide plate unit 10 as substantially parallel light, thereby improving the uniformity of light in the thickness direction.

[0043] The reflection separation section 43 is provided between the exit-side reflective surface 42 and the opposite-side reflective surface 41, and is the part that separates the two reflective surfaces. The reflection separation section 43 is made of the material that constitutes the incident-side light guide plate section 10, and is also provided in the region that overlaps with the light incident section 30 in a plan view. Therefore, of the light incident from the light incident section 30, the light in the region that overlaps with the reflection separation section 43 in a plan view does not enter either the opposite-side reflective surface 41 or the exit-side reflective surface 42, but passes to the back surface of the incident-side light guide plate section 10. As a result, propagation of light incident in the region corresponding to the reflection separation section 43 in the in-plane direction of the incident-side light guide plate section 10 is suppressed, preventing stray light and improving brightness uniformity.

[0044] The Fresnel reflector 51 is located at the center of the width direction of the direction-changing reflector 50, and is the portion where light reflected by the exit-side reflector 42 is incident and reflected as substantially parallel light in the in-plane direction of the exit-side light guide plate 20. The light incident on the Fresnel reflector 51 is the light reflected by the exit-side reflector 42, and reaches the Fresnel reflector 51 while spreading in the width direction corresponding to the curved shape of the exit-side reflector 42. Therefore, the shape of the Fresnel reflector 51 is preferably a Fresnel shape in which a paraboloid of rotation is used as the basic reflective surface, and the paraboloid of rotation is divided into multiple parts in the width direction and extension direction of the exit-side light guide plate 20, in order to convert light that spreads in a fan shape into parallel light.

[0045] Furthermore, the range of light reaching the Fresnel reflecting portion 51 in the width direction varies depending on the thickness direction of the incident light guide plate portion 10. Therefore, it is preferable that the width of the Fresnel reflecting portion 51 is narrower at the upper end closer to the incident light portion 30, and wider towards the lower end further from the incident light portion 30. In the examples shown in Figures 4(a), 5, and 6, the Fresnel reflecting portion 51 is divided into 8 sections in the width direction and 6 sections in the extension direction, but the number of divisions in the Fresnel shape is not limited. In addition, in order to diffuse the light reflected by the Fresnel reflecting portion 51 in multiple directions in the thickness direction of the output light guide plate portion 20, curvature and irregularities for scattering light may be provided in each part of the Fresnel shape.

[0046] The stepped reflective sections 52 are provided on both sides of the direction-changing reflective section 50 in the width direction, and are portions into which light reflected by the folded-back reflective end face 80 is incident and reflected as substantially parallel light in the in-plane direction of the output-side light guide plate section 20. The light incident on the stepped reflective section 52 is light reflected by the folded-back reflective end face 80, and reaches the stepped reflective section 52 as substantially parallel light in the width direction, corresponding to the curved shape of the folded-back reflective end face 80. Therefore, it is preferable that the shape of the stepped reflective section 52 be a stepped shape divided into multiple sections in the extension direction so that the substantially parallel light does not expand in the width direction.

[0047] Furthermore, since the stepped reflective section 52 is provided on both sides of the Fresnel reflective section 51, it is wider at the upper end closer to the light incident section 30 and narrows towards the lower end further from the light incident section 30. In addition, in order to diffuse the light reflected by the stepped reflective section 52 in multiple directions in the thickness direction of the output-side light guide plate section 20, curvature and irregularities for scattering light may be provided in each part of the stepped shape.

[0048] The intermediate reflective section 60 has a shape in which a reflective surface is cut out in the thickness direction from the back surface of the incident light guide plate section 10. Figures 4(b), 5, and 6 show an example in which the intermediate reflective section 60 is cut out in a triangular pyramidal shape with a triangular reflective surface from a triangular opening, but the shape is not limited. By making the reflective surface of the intermediate reflective section 60 triangular in shape, making it shallower on the side closer to the re-reflecting end surface 70 and deeper on the side closer to the folded-back reflective end surface 80, the amount of light irradiated to both ends in the width direction of the incident light guide plate section 10 can be appropriately adjusted.

[0049] Light reflected from the reflective surface of the intermediate reflector 60 propagates inside the incident light guide plate 10 and reaches the vicinity of the boundary between the Fresnel reflector 51 and the stepped reflector 52. As described above, the light reaching the Fresnel reflector 51 is the light reflected from the exit reflective surface 42, and the light reaching the stepped reflector 52 is the light reflected from the opposite reflective surface 41, the re-reflected end surface 70, and the folded-back reflective end surface 80. By providing the intermediate reflector 60 and reflecting light to the vicinity of the boundary between the Fresnel reflector 51 and the stepped reflector 52, the lack of light at the boundary between the two can be compensated for, and a more uniform luminance distribution can be achieved.

[0050] As shown in Figures 4(b) and 5, the normal direction of each surface constituting the light-reflecting recess 40 and the intermediate-reflecting portion 60 is within the range of 0 degrees to 90 degrees with respect to a predetermined direction. In other words, when viewed from the front side from the back side of the incident-side light guide plate portion 10, all surfaces constituting the light-reflecting recess 40 and the intermediate-reflecting portion 60 are directly visible, and there are no overhang-shaped portions covered by the material constituting the optical member 100. Similarly, the surfaces constituting the back surface of the incident-side light guide plate portion 10 and the back surface 91 of the exit-side light guide plate portion 20 are also within the range of 0 degrees to 90 degrees with respect to a predetermined direction. This makes it easier to remove the material constituting the optical member 100 when molding it with a mold, improving work efficiency.

[0051] Figure 7 is a schematic diagram illustrating the path of light incident from the light incident section 30. The light source section 120 is positioned so as to coincide with the vertex P of the light reflection recess 40 in a plan view. The solid arrows in the figure show typical paths of some of the light reflected by the light reflection recess 40. The dashed arrows in the figure show some of the directions in which light is not reflected by the light reflection recess 40.

[0052] Of the light incident from the light incident section 30, the light that reaches the opposite reflection surface 41 propagates in the in-plane direction through the incident light guide plate section 10 and reaches the re-reflected end surface 70. The light reflected by the re-reflected end surface 70 propagates to both sides in the width direction. The shape of the re-reflected end surface 70 is concave to prevent the reflected light from expanding too much in the in-plane direction within the incident light guide plate section 10.

[0053] A portion of the light reflected by the re-reflecting end face 70 is reflected by the reflective surface of the intermediate reflecting section 60 towards the exit-side light guide plate section 20. The light reflected by the intermediate reflecting section 60 reaches the vicinity of the boundary region between the Fresnel reflecting section 51 and the stepped reflecting section 52 of the direction-changing reflecting section 50, is reflected by the respective reflective surfaces of the Fresnel reflecting section 51 and the stepped reflecting section 52, and propagates in the in-plane direction of the exit-side light guide plate section 20.

[0054] Of the light reflected by the re-reflecting end face 70, the light that is not reflected by the intermediate reflecting section 60 reaches the folded-back reflecting end face 80, is reflected, and propagates as substantially parallel light in the direction of the exiting light guide plate section 20 within the plane of the incident light guide plate section 10. The light reflected by the re-reflecting end face 70 reaches the stepped reflecting section 52 of the direction-changing reflecting section 50, is reflected by each reflecting surface of the stepped reflecting section 52, and propagates in the in-plane direction of the exiting light guide plate section 20.

[0055] Of the light incident from the light incident section 30, the light that reaches the exit-side reflecting surface 42 propagates while spreading within the plane of the incident-side light guide plate section 10 and reaches the Fresnel reflecting section 51 of the direction-changing reflecting section 50. The light that reaches the Fresnel reflecting section 51 is reflected according to the Fresnel shape of the Fresnel reflecting section 51 and is converted to be approximately parallel in the width direction of the exit-side light guide plate section 20.

[0056] Of the light incident from the light incident section 30, the light that reaches the reflection separation section 43 is not reflected by either the opposite reflection surface 41 or the output reflection surface 42, but is transmitted to the back side of the incident light guide plate section 10. Therefore, stray light spreading in the width direction from the light incident section 30 to the incident light guide plate section 10, as shown by the dashed line in Figure 7, can be suppressed. This makes it possible to suppress brightness unevenness from the light output section 90.

[0057] Figure 8 is a schematic perspective view showing an enlarged view of the direction-changing reflective section 50. The Fresnel reflective section 51 and the stepped reflective section 52 are provided along the extending direction of the output-side light guide plate section 20. The Fresnel reflective section 51 uses a paraboloid of rotation as its basic reflective surface, and the curved portion of the paraboloid of rotation is divided into multiple sections in the extending direction and width direction, creating a Fresnel shape with a constant thickness. Because the Fresnel shape of the Fresnel reflective section 51 is based on a paraboloid of rotation, the width is narrower towards the upper end of the output-side light guide plate section 20, which is closer to the light source section 120, and widens towards the lower end. The stepped reflective section 52 is a stepped shape divided into multiple sections in the extending direction of the output-side light guide plate section 20, and each divided step is a slightly concave curved surface.

[0058] As described above, the light incident from the light incident section 30 is reflected by the opposite reflective surface 41, the exiting reflective surface 42, the intermediate reflective section 60, the re-reflecting end surface 70, the folded reflective end surface 80, the Fresnel reflective section 51, and the stepped reflective section 52. As a result, the light propagating through the exiting light guide plate section 20 has its spread in the width direction suppressed, becoming approximately parallel light, and the light emitting section 90 can be illuminated with uniform brightness. In addition, the light reflected by the Fresnel reflective section 51 and the stepped reflective section 52 spreads in the thickness direction of the exiting light guide plate section 20, so brightness unevenness can be suppressed at positions along the extension direction.

[0059] As described above, in the optical member 100, light source unit 1 and vehicle lamp of this embodiment, the light reflective recess 40 has an output-side reflective surface 42 that reflects a portion of the light toward the output-side light guide plate portion 20, and an opposite-side reflective surface 41 that reflects the other portion of the light toward the opposite direction from the output-side light guide plate portion 20. The output-side reflective surface 42 and the opposite-side reflective surface 41 are separated by a reflection separation portion 43, so that even if the light output portion 90 is enlarged, light can be emitted with uniform brightness.

[0060] (Second Embodiment) Next, a second embodiment of the present invention will be described with reference to Figure 9. Details that overlap with the first embodiment will be omitted. Figure 9 is a schematic top view showing the structure of the optical member 200 according to this embodiment. Figure 9 shows the side of the incident light guide plate 10 where the light incident portion 30 is provided, and the direction-changing reflective portion 50, while the light-reflecting recess 40, the intermediate reflective portion 60, and the exit light guide plate 20 are omitted from the illustration.

[0061] As shown in Figure 9, the optical member 200 has multiple light incident sections 30 on the incident light guide plate section 10, and corresponding to the light incident sections 30 are the opposite reflective surface 41, the exit reflective surface 42, the intermediate reflective section 60, the re-reflected end surface 70, the folded-back reflective end surface 80, the Fresnel reflective section 51, and the stepped reflective section 52. The relative positional relationship of the light incident sections 30, the opposite reflective surface 41, the exit reflective surface 42, the intermediate reflective section 60, the re-reflected end surface 70, the folded-back reflective end surface 80, the Fresnel reflective section 51, and the stepped reflective section 52 is the same as in the first embodiment. In the vertical direction in Figure 9, the positions of adjacent light incident sections 30 are different. Figure 9 shows an example in which multiple light incident sections 30 are provided on the incident light guide plate section 10, but multiple incident light guide plate sections 10 may be arranged in a row.

[0062] The dashed line shown in Figure 9 represents a hypothetical straight line along the boundary between the incident light guide plate section 10 and the exit light guide plate section 20, and is inclined with respect to the width direction (left-right direction in the figure) of the incident light guide plate section 10. Therefore, the width direction of the exit light guide plate section 20 is also inclined with respect to the width direction of the incident light guide plate section 10, and the upper and lower ends of the Fresnel reflector section 51 and the stepped reflector section 52 are positioned diagonally along the inclination of the exit light guide plate section 20.

[0063] As shown in Figure 9, in the optical member 200, the Fresnel reflecting portion 51 and the stepped reflecting portion 52 of the direction-changing reflecting portion 50 are arranged in a region divided in the width direction along the inclination of the exiting light guide plate portion 20. Therefore, the Fresnel reflecting portion 51 and the stepped reflecting portion 52 are provided with a step along the boundary between the incident light guide plate portion 10 and the exiting light guide plate portion 20, and are given a Fresnel shape. As a result, the optical member 200 can guide light uniformly in accordance with the inclination of the exiting light guide plate portion 20, and can achieve light irradiation with uniform brightness even with various design shapes.

[0064] (Third embodiment) Next, a third embodiment of the present invention will be described. Details that overlap with the first embodiment will be omitted. In the optical member 100 and light source unit 1 of the first embodiment, an example was shown in which the incident light guide plate portion 10 and light source portion 120 were provided only on the upper end side of the exit light guide plate portion 20. However, the incident light guide plate portion 10 and light source portion 120 may also be provided on the lower end side of the exit light guide plate portion 20, resulting in a symmetrical shape vertically. By providing the incident light guide plate portion 10 and light source portion 120 at both the upper and lower ends, a uniform luminance distribution can be achieved throughout the light emission portion 90 even if the exit light guide plate portion 20 is enlarged in the extension direction.

[0065] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of Symbols]

[0066] 100,200… Optical components 1…Light source unit 10...Incidence side light guide plate part 20... Light guide plate section on the emission side 30...Light incidence part 31… Opposite side 32... Side view 40…Light-reflecting recess 41… Opposite reflective surface 42…Output side reflective surface 43…Reflection separation section 50... Directional change reflective section 51... Fresnel reflector 52...Step reflective section 60...Intermediate reflective section 70...Re-reflection end face 80…Reflection end face 90...Light emission section 91...Back side 110... Circuit board 120...Light source section

Claims

1. An optical component that guides light incident from a light incident part through a light guide part and emits it from a light emission part, The light guide portion comprises an incident light guide plate portion on which the light incident portion is provided, and an outgoing light guide plate portion extending in a direction intersecting the extending direction of the incident light guide plate portion. The output-side light guide plate is provided with a direction-changing reflecting section for reflecting the light guided from the input-side light guide plate and guiding it within the output-side light guide plate. The incident light guide plate portion is provided with a light-reflecting recess at a position corresponding to the light incident portion. The light-reflecting recess has an output-side reflective surface that reflects a portion of the light in the direction of the output-side light guide plate, and an opposite-side reflective surface that reflects the other portion of the light in the direction opposite to the output-side light guide plate. An optical member characterized in that the emission-side reflective surface and the opposite-side reflective surface are separated by a reflection separation portion.

2. The optical member according to claim 1, The incident light guide plate portion has a light-reflecting end surface on the side opposite to the exit light guide plate portion. The optical member is characterized in that the light-reflecting end face has a re-reflecting end face that reflects the light reflected by the opposite reflective surface, and a folded-back reflective end face that reflects the light reflected by the re-reflecting end face in the direction of the output-side light guide plate.

3. The optical member according to claim 2, The optical member is characterized in that the folded reflective end face has a Fresnel shape and reflects the light as substantially parallel light in the direction of the output side light guide plate.

4. The optical member according to claim 2, An optical member characterized by having an intermediate reflecting portion provided between the re-reflecting end surface and the folded-back reflecting end surface, which reflects a portion of the light reflected by the re-reflecting end surface in the direction of the output-side light guide plate portion.

5. The optical member according to claim 4, The optical member is characterized in that the light-reflecting recess and the intermediate-reflecting portion are concave in shape and provided on the opposite side of the light incident portion, and are composed only of surfaces whose normal direction is in the range of 0 degrees to 90 degrees with respect to a predetermined direction.

6. The optical member according to claim 1, The optical member is characterized in that the direction-changing reflective portion has a Fresnel reflective portion that receives the light reflected from the output-side reflective surface and reflects the light as substantially parallel light in the in-plane direction of the output-side light guide plate portion.

7. The optical member according to claim 6, The optical member is characterized in that the direction-changing reflective portion has a stepped reflective portion that receives the light reflected from the opposite reflective surface and reflects the light in the in-plane direction of the output-side light guide plate portion.

8. The optical member according to claim 1, The direction-changing reflective portion is an optical member characterized by diffusing and reflecting the light in the thickness direction of the light-guiding plate portion on the emission side.

9. An optical member according to any one of claims 1 to 8, A light source unit characterized by comprising a light source unit arranged opposite to the light incident portion.

10. A vehicle lighting device characterized by arranging a plurality of light source units as described in claim 9.

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