Optical components and illumination devices

Abstract

To provide an optical member and an illumination device capable of unifying light distribution along a prescribed direction and improving utilization efficiency of light.SOLUTION: An optical member (113) has a light incident surface to which light is incident, and a light emission surface disposed in opposition to the light incident surface. The light incident surface and the light emission surface are formed along a prescribed direction, and has a central region (113a) positioned at the center in the prescribed direction, and both side regions (113b) positioned at both sides of the central region (113a) along the prescribed direction. The central region (113a) has negative optical power, and both side regions (113b) have positive optical power.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an optical member and a lighting device.

Background Art

[0002] Conventionally, a light source device using a lens that utilizes total reflection, so-called a TIR lens, is known. The TIR lens includes a refraction portion disposed at the central portion and a reflection portion disposed around the refraction portion. As a document that discloses a light source device using a TIR lens, for example, Patent Document 1 is known.

[0003] The optical unit (light source device) disclosed in Patent Document 1 includes a plurality of light sources (light emitting elements), a plurality of optical means (TIR lenses) having the function of a collimating lens respectively disposed on the plurality of light sources, and a plurality of lens arrays disposed on the emission surface side of the plurality of optical means, and forms a plurality of different light distribution patterns. The use of the optical unit disclosed in Patent Document 1 is mainly for vehicle lamps.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The light source devices described above are sometimes used as lighting devices (backlights) for head-up displays (hereinafter sometimes referred to as "HUDs") mounted on vehicles, for example. Light source devices used in HUDs are required to be particularly bright and uniform, that is, to have a high-brightness and uniform brightness distribution. In other words, they are required to have high luminous flux utilization efficiency and appropriate light distribution. The TIR lenses described above can also focus light that spreads outward with a large angle (direction angle) with respect to the emission axis of the light source, so they are often used as optical means suitable for this purpose.

[0006] Figure 9 is a schematic diagram illustrating the overview and light irradiation of a conventional lighting device using a TIR lens. As shown in Figure 9, the conventional lighting device comprises multiple light-emitting elements 1, a TIR lens 2, a light distribution adjustment lens 3, a diffusion sheet 4, and a display unit 5. The arrows in the figure schematically indicate the direction of light propagation emitted from each light-emitting element 1.

[0007] Multiple light-emitting elements 1 are arranged along the horizontal direction (a predetermined direction) in the figure and irradiate light in the direction of the TIR lens 2. The TIR lens 2 is formed by extending in the horizontal direction in the figure and collimates the light from the light-emitting elements 1 in a direction perpendicular to the plane of the paper in Figure 9 (second direction). The light distribution adjustment lens 3 refracts the light from the light-emitting elements 1 via the TIR lens 2 and irradiates the diffusion sheet 4 and the display unit 5. The diffusion sheet 4 transmits the irradiated light while diffusing or scattering it. The display unit 5 is a part that transmits light from a liquid crystal display device or the like to display an image, and displays the image using light from the back side that has been diffused by the diffusion sheet 4.

[0008] In the conventional lighting device shown in Figure 9, as an example, a concave lens is used as the light distribution adjustment lens 3, in which the light incident surface and light exit surface are concave over the entire area in the lateral direction (a predetermined direction) shown in the figure. This expands the illumination range of the light transmitted through the TIR lens 2 along the predetermined direction, allowing for good illumination of a wide area on the diffusion sheet 4 and the display unit 5.

[0009] However, by using a concave lens as the light distribution adjustment lens 3, the light incident on both ends of the TIR lens 2 and the light distribution adjustment lens 3 in a predetermined direction is further expanded outward. As a result, some of the light travels outside the range of the diffusion sheet 4 and the display unit 5, which reduces the utilization efficiency of the light emitted from the light-emitting element 1.

[0010] Therefore, the present invention has been made in view of the above-mentioned conventional problems, and aims to provide an optical component and lighting device that can equalize the light distribution along a predetermined direction and improve the efficiency of light utilization. [Means for solving the problem]

[0011] To solve the above problems, the present invention Lighting device teeth, A plurality of light-emitting parts arranged along a predetermined direction and emitting light, and formed along the predetermined direction, A light incident surface into which the light enters, and a light exit surface positioned opposite the light incident surface. The optical member comprises an optical member having, The device has a central region located in the center of the predetermined direction and side regions located on both sides of the central region along the predetermined direction, wherein the central region has negative optical power and the side regions have positive optical power.

[0012] In the optical member of the present invention, the optical member has negative optical power in the central region in a predetermined direction and positive optical power in the regions on both sides. This allows the light to be amplified near the central region while being concentrated within the irradiation range in the regions on both sides, thereby uniformizing the light distribution along the predetermined direction and improving the efficiency of light utilization.

[0013] Furthermore, in one aspect of the present invention, the central region has a concave lens shape that is thin near the center and thick at the edges in the predetermined direction, and the side regions have a convex lens shape that is thin at the edges in the predetermined direction.

[0014] Furthermore, in one aspect of the present invention, the central region has a meniscus lens shape in which the light incident surface and the light output surface are curved in the direction of light incidence in the predetermined direction.

[0015] In one aspect of the present invention, a lenticular portion in which concavities and convexities are repeated along two axial directions orthogonal to the predetermined direction is formed on the light incident surface or the light exit surface.

[0016] Also, In one aspect of the present invention, having a collimating lens disposed between the optical member and the light emitting portion 。

[0017] In one aspect of the present invention, a plurality of the light emitting portions are arranged along the predetermined direction, and the collimating lens is an internal total reflection lens including a refracting portion disposed at the center along a second direction orthogonal to the predetermined direction and reflecting portions disposed on both sides of the refracting portion.

[0018] In one aspect of the present invention, in the internal total reflection lens, the refracting portion and the reflecting portion are extended in the predetermined direction.

Advantages of the Invention

[0019] In the present invention, it is possible to provide an optical member and a lighting device capable of equalizing a light distribution pattern along a predetermined direction and improving the utilization efficiency of light.

Brief Description of the Drawings

[0020] [Figure 1] It is a diagram schematically explaining the outline of the lighting device 100 according to the first embodiment. FIG. 1(a) is a schematic cross-sectional view along a predetermined direction, and FIG. 1(b) is a schematic cross-sectional view along a second direction. [Figure 2] It is a diagram schematically explaining the outline of the lighting device 200 according to the second embodiment, and is a schematic cross-sectional view along a predetermined direction. [Figure 3] It is a schematic diagram explaining the progress of light in the lighting devices 100 and 200. FIG. 3(a) shows the light distribution adjustment lens 113, and FIG. 3(b) shows the light distribution adjustment lens 213. [Figure 4]It is a schematic diagram for explaining the propagation of light near the boundary where the positive and negative of the optical power are switched. Fig. 4(a) shows the light distribution adjustment lens 113, and Fig. 4(b) shows the light distribution adjustment lens 213. [Figure 5] It is a diagram schematically showing the range 213d having the maximum thickness in the light distribution adjustment lens 213. [Figure 6] It is a diagram showing virtual image display and luminance in the lighting devices 100 and 200. Fig. 6(a) shows the virtual image obtained by the lighting device 100, Fig. 6(b) shows the virtual image obtained by the lighting device 200, Fig. 6(c) shows the luminance distribution of the lighting device 100, and Fig. 6(d) shows the luminance distribution of the lighting device 200. [Figure 7] It is a graph showing the luminance distributions of the lighting devices 100 and 200. Fig. 7(a) shows the relative luminance distribution of the lighting device 100, and Fig. 7(b) shows the relative luminance distribution of the lighting device 200. [Figure 8] It is a diagram showing the case where a lenticular portion 213c is provided on the light incident surface of the light distribution adjustment lens 213. Fig. 8(a) is a schematic cross-sectional view along a predetermined direction, and Fig. 8(b) is a schematic perspective view. [Figure 9] It is a schematic diagram for explaining the outline and light irradiation of a lighting device using a conventional TIR lens.

Embodiments for Carrying Out the Invention

[0021] (First Embodiment) Embodiments of the present invention will now be described in detail 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 diagram illustrating the outline of the lighting device 100 according to this embodiment, where Figure 1(a) is a schematic cross-sectional view along a predetermined direction, and Figure 1(b) is a schematic cross-sectional view along a second direction. In Figure 1(a), the horizontal direction is the x-axis direction (predetermined direction), the vertical direction is the z-axis direction, and the direction perpendicular to the plane of the paper is the y-axis direction (second direction). In Figure 1(b), the horizontal direction corresponds to the y-axis direction, the vertical direction corresponds to the z-axis direction, and the direction perpendicular to the plane of the paper corresponds to the x-axis direction. As shown in Figures 1(a) and 1(b), the lighting device 100 includes a light-emitting element 111, a TIR lens 112, a light distribution adjustment lens 113, a diffusion sheet 114, and a display unit 115.

[0022] The light-emitting element 111 is an electronic component mounted on a mounting substrate (not shown) on which wiring is formed, and emits light in a predetermined color when current is supplied by a drive circuit. Multiple light-emitting elements 111 are arranged along the x-axis direction (a predetermined direction), and this corresponds to the light-emitting part in the present invention. Here, "arranged along the x-axis direction" includes cases that can be substantially considered as the x-axis direction, and may include inclinations of several degrees or staggered arrangements. The specific structure of the light-emitting element 111 is not limited, but an LED package can be used that combines a light-emitting diode (LED) that emits primary light and a wavelength conversion member that converts a portion of the primary light into secondary light. The material of the light-emitting diode is also not limited, and known materials and structures can be used. As an example, a GaN-based LED that emits blue light can be used. The material of the wavelength conversion member is also not limited, and as an example, a YAG-based phosphor material that is excited by blue light and emits yellow light can be used. In this embodiment, the number of light-emitting elements 111 is shown as one row, but there may be two or more rows. Furthermore, the light-emitting element 111 is not limited to LEDs but may also be a semiconductor laser or the like.

[0023] The TIR lens 112 is positioned between the multiple light-emitting elements 111 and the light distribution adjustment lens 113, and extends along the arrangement direction (x-axis direction) of the light-emitting elements 111. The TIR lens 112 also has a centrally located refraction portion 112a and reflective portions 112b positioned on both sides of the refraction portion 112a in the y-axis direction (second direction) perpendicular to the x-axis direction. The reflective portion 112b has a reflective surface 112c with an inclined outer surface in the y-axis direction. The surfaces of the refraction portion 112a and the reflective portion 112b facing the light distribution adjustment lens 113 have an emission surface 112d. A portion of the light emitted from the light-emitting elements 111 enters the refraction portion 112a, is refracted according to the refractive index difference, passes through the refraction portion 112a, and is emitted from the emission surface 112d to the light distribution adjustment lens 113. Furthermore, some of the light emitted from the light-emitting element 111 enters the reflecting element 112b from the inner surface provided at the boundary between the refracting element 112a and the reflecting element 112b, undergoes total internal reflection at the reflecting surface 112c, and is emitted from the exit surface 112d onto the light distribution adjustment lens 113.

[0024] As shown in Figure 1(b), the TIR lens 112 functions as a collimating lens that focuses the light emitted from the light-emitting element 111, which has a large directional angle, in the y-axis direction by total internal reflection (TIR), and emits it as, for example, parallel light or light that is close to parallel light (hereinafter, both are collectively referred to as "approximately parallel light"). Therefore, the TIR lens 112 corresponds to the total internal reflection lens in this invention. Light emitted from the light-emitting element 111 with a large directional angle is, for example, the light that spreads outward in the y-axis direction in Figure 1(b). In other words, the TIR lens 112 can efficiently focus the light emitted from the light-emitting element 111.

[0025] The light distribution adjustment lens 113 is positioned on the light output surface 112d side of the TIR lens 112 and has a light incident surface into which light enters and a light output surface positioned opposite the light incident surface. The light distribution adjustment lens 113 is formed by extending along the x-axis direction and has a central region 113a and side regions 113b. Furthermore, a lenticular portion 113c with repeated irregularities along the y-axis direction is formed on the light incident surface side of the light distribution adjustment lens 113. In this embodiment, an example is shown in which the lenticular portion 113c is provided on the light incident surface side, but the lenticular portion 113c may also be provided on the light output surface side, or the lenticular portion 113c may be omitted.

[0026] The central region 113a is located in the center in the x-axis direction and is a region with negative optical power. The side regions 113b are located on either side of the central region 113a and are regions with positive optical power. The boundary between the central region 113a and the side regions 113b may not be clearly defined in terms of shape, but when parallel light is incident from the light incident surface, the region where the light emitted from the light exit surface is expanded corresponds to the central region 113a, and the region where the light is focused corresponds to the side regions 113b. Therefore, the light distribution adjustment lens 113 corresponds to the optical component in this invention. The specific shapes of the central region 113a and the light distribution adjustment lens 113 are not limited, but a combination of the central region 113a, which is a concave lens shape that is thin near the center and thick at the ends, and the side regions 113b, which are convex lens shapes that are thin at the ends, can be used, as shown in Figure 1(a).

[0027] The TIR lens 112 and the light distribution adjustment lens 113 work together to guide the light emitted from the light-emitting element 111 to the illumination area of ​​the object to be illuminated. In this embodiment, the back surface of the diffusion sheet 114 (the surface facing the light-emitting element 111) is used as an example of the illumination area. However, the location of the illumination area can be determined by considering the specifications of the light source device, etc. For example, the back surface of the display unit 115 may be directly illuminated. The TIR lens 112 and the light distribution adjustment lens 113 are made of, for example, a resin such as acrylic resin, glass, or the like.

[0028] The diffusion sheet 114 is an optical component positioned between the light distribution adjustment lens 113 and the display unit 115, transmitting light emitted from the light distribution adjustment lens 113 while diffusing or scattering it. Therefore, the diffusion sheet 114 functions to diffuse the highly directional light deflected by the TIR lens 112 and the light distribution adjustment lens 113 and emit it to the display unit 115, thereby illuminating the display unit 115 more uniformly. The specific material and structure of the diffusion sheet 114 are not limited; it may be a roughly plate-like material with light-scattering particles dispersed in a resin, or it may be a sheet with a structure in which minute irregularities are formed on the surface of a resin material.

[0029] The display unit 115 is a device that displays an image in response to an image signal from a control unit (not shown). The specific configuration of the display unit 115 is not limited, but a liquid crystal display device or the like that can be used to display an image by transmitting light from the back side (the side of the light-emitting element 111).

[0030] As shown in Figures 1(a) and 1(b), the light emitted from the light-emitting element 111 is incident on the TIR lens 112 while expanding in the x-axis and y-axis directions. Also, as shown in Figure 1(a), since the structure of the TIR lens 112, with its refracting portion 112a and reflective portion 112b, is extended along the x-axis, the light that has spread in the x-axis direction is then expanded and emitted from the emission surface 112d toward the light distribution adjustment lens 113. The light incident on the central region 113a of the light distribution adjustment lens 113 is refracted in a direction that expands further due to negative optical power, and illuminates a wide area near the center of the diffusion sheet 114 and the display unit 115. The light incident on both side regions 113b of the light distribution adjustment lens 113 is refracted in a direction that focuses due to positive optical power, and illuminates the area near both sides of the diffusion sheet 114 and the display unit 115 with focused or parallel light.

[0031] Furthermore, as shown in Figure 1(b), since the TIR lens 112 has a refractive section 112a and a reflective section 112b in the y-axis direction, it functions as a collimating lens in the y-axis direction, and light is emitted from the emission surface 112d as substantially parallel light. The light collimated in the y-axis direction is refracted by the lenticular section 113c provided on the light incidence surface of the light distribution adjustment lens 113 before being emitted onto the diffusion sheet 114.

[0032] Since the multiple light-emitting elements 111 are arranged in the x-axis direction, the light intensity tends to be relatively high near the center of the x-axis where light from multiple light-emitting elements 111 overlaps and reaches, while the light intensity tends to be relatively low near both ends of the x-axis where light from only the end light-emitting elements 111 reaches. However, in the illumination device 100 of this embodiment, negative optical power is applied to the light in the central region 113a of the light distribution adjustment lens 113, expanding the light incident on the center of the x-axis and widening the light distribution of the emitted light. In addition, positive optical power is applied to the light in the side regions 113b of the light distribution adjustment lens 113, focusing the light incident on both ends of the x-axis and increasing the amount of light irradiated within the range of the diffusion sheet 114. Therefore, the light irradiated onto the diffusion sheet 114 via the light distribution adjustment lens 113 has a uniform light distribution along the x-axis direction, and the light utilization efficiency is improved.

[0033] As described above, in the light distribution adjustment lens 113 and illumination device 100 of this embodiment, the light distribution adjustment lens 113 has negative optical power in the central region 113a in the x-axis direction and positive optical power in the side regions 113b. This allows the light to be amplified near the central region 113a while being concentrated within the illumination range in the side regions 113b, thereby making the light distribution uniform along the x-axis direction and improving the efficiency of light utilization.

[0034] (Second Embodiment) Next, a second embodiment of the present invention will be described with reference to Figure 2. Details that overlap with the first embodiment will be omitted. Figure 2 is a schematic diagram illustrating the outline of the lighting device 200 according to this embodiment, and is a schematic cross-sectional view along a predetermined direction. As shown in Figure 2, the lighting device 200 includes a light-emitting element 211, a TIR lens 212, a light distribution adjustment lens 213, a diffusion sheet 214, and a display unit 215. The structure of the refraction portion 112a and the reflection portion 112b along the y-axis direction of the TIR lens 212 is the same as in the first embodiment, and will not be described.

[0035] In the lighting device 200 of this embodiment, the light distribution adjustment lens 213 is formed by extending along the x-axis direction and has a central region 213a and side regions 213b. The central region 213a has negative optical power, and the side regions 113b have positive optical power. As shown in Figure 2, in this embodiment, the central region 213a has a meniscus lens shape, with the light incident surface and light exit surface curved in the direction of the light-emitting element 211 (the direction of light incidence) in the x-axis direction.

[0036] In the light distribution adjustment lens 213 and illumination device 200 of this embodiment, the light distribution adjustment lens 213 has negative optical power in the central region 213a in the x-axis direction and positive optical power in the side regions 213b. This allows the light to be amplified near the central region 213a while being concentrated within the illumination range in the side regions 213b, thereby making the light distribution uniform along the x-axis direction and improving the efficiency of light utilization.

[0037] (Explanation of uniformizing light distribution) Figure 3 is a schematic diagram illustrating the propagation of light in the lighting devices 100 and 200, where Figure 3(a) shows the light distribution adjustment lens 113 and Figure 3(b) shows the light distribution adjustment lens 213. Figures 3(a) and 3(b) schematically show the path of light that receives negative optical power near the boundary between the central regions 113a and 213a and the side regions 113b and 213b. Similar to the first embodiment, in the central regions 113a and 213a and the side regions 113b and 213b of the light distribution adjustment lenses 113 and 213, the incident light receives negative and positive optical power, respectively, making it possible to equalize the light distribution along the x-axis and improve the light utilization efficiency.

[0038] As shown in Figure 3(a), in the light distribution adjustment lens 113 of the lighting device 100, the central region 113a has a concave lens shape, and the side regions 113b have convex lens shapes. Therefore, the curvature change between the light incident surface and the light exit surface becomes large at the boundary between the two. In particular, near the side regions 113b of the central region 113a, the negative optical power is greater than in the center of the central region 113a, resulting in light that propagates outside the diffusion sheet 114. In particular, for light incident from the light-emitting element 111 located on the opposite side of the central region 113a, it is difficult to appropriately set the direction of light propagation so that it remains within the diffusion sheet 114.

[0039] As shown in Figure 3(b), in the light distribution adjustment lens 213 of the lighting device 200, the central region 213a has a meniscus lens shape, and the side regions 213b have convex lens shapes. Therefore, the change in curvature between the light incident surface and the light exit surface at the boundary between the two can be made smaller than that of the light distribution adjustment lens 113. Consequently, the negative optical power in the central region 213a is approximately the same throughout the entire region, and light traveling outside the diffusion sheet 214 can be suppressed. In particular, even for light incident from the light-emitting element 211 located on the opposite side of the central region 213a, the direction of light propagation can be set to stay within the diffusion sheet 214, increasing the amount of light incident within the diffusion sheet 214 and achieving further uniformity.

[0040] Figure 4 is a schematic diagram illustrating the propagation of light near the boundary where the positive and negative optical power switch. Figure 4(a) shows the light distribution adjustment lens 113, and Figure 4(b) shows the light distribution adjustment lens 213. In the light distribution adjustment lens 113, as shown in Figure 4(a), in the central region 113a, some of the light that is incident obliquely on the edge of the light incident surface is strongly affected by the negative optical power and spreads outward in the x-axis direction, and may be emitted from the light exit surfaces of both side regions 113b. In both side regions 113b, the light is strongly affected by the positive optical power, causing it to propagate further outward in the x-axis direction.

[0041] In contrast, with the light distribution adjustment lens 213, as shown in Figure 4(b), light incident at an oblique angle to the edge of the light incident surface in the central region 213a receives negative optical power, but reaches and is emitted on the light emission surface of both side regions 213b closer to the central region 213a. Therefore, the positive optical power received in both side regions 213b is weaker than with the light distribution adjustment lens 113, reducing the angle of light directed outward in the x-axis direction and keeping it within the range of the diffusion sheet 214.

[0042] Figure 5 schematically shows the range 213d in the light distribution adjustment lens 213 where the maximum thickness is located. In Figure 5, only the portion of the light distribution adjustment lens 213 that has optical power is shown, but a retaining member for proper holding and fixing may be formed integrally with the light distribution adjustment lens 213. When the retaining member is formed integrally with the light distribution adjustment lens 213, the thickness of the light distribution adjustment lens 213 refers to the thickness of the portion that has optical power and contributes to the refraction of light. The light distribution adjustment lens 213 has a central region 213a with a meniscus lens shape and convex lens-shaped regions 213b on both sides, and the thickness in the z-axis direction is at its maximum value at any position in the x-axis direction. The position where the light distribution adjustment lens 213 has its maximum thickness is called the thickest position. If the center in the x-axis direction is expressed as 0% and both ends as 100%, it is preferable that the thickest position lies within the range 213d of 5% to 95%. If the thickest point is smaller than the range 213d, the light diffusion by the central region 213a will be insufficient. Conversely, if the thickest point is larger than the range 213d, the light focusing in the side regions 213b will be insufficient, and the amount of light reaching outside the diffusion sheet 214 will increase. Figure 5 shows only the light distribution adjustment lens 213 in which the central region 213a has a meniscus lens shape, but the same applies to the light distribution adjustment lens 113 in which the central region 113a has a concave lens shape. Also, although Figure 5 shows an example of a symmetrical shape for the light distribution adjustment lens 213, it may be asymmetrical, and the maximum thickness and thickest point in the left and right ranges 213d may differ.

[0043] Figure 6 shows the virtual image display and luminance of lighting devices 100 and 200. Figure 6(a) shows the virtual image obtained with lighting device 100, Figure 6(b) shows the virtual image obtained with lighting device 200, Figure 6(c) shows the luminance distribution of lighting device 100, and Figure 6(d) shows the luminance distribution of lighting device 200. The virtual image and luminance cross-sections shown in Figures 6(a) to 6(d) are viewed from the left edge of the area (eyebox) where the driver's eyes are assumed to be located, using lighting devices 100 and 200 as backlights for a HUD device. As shown in Figures 6(a) to 6(d), it can be seen that both the virtual image and the virtual image luminance are illuminated with a uniform light distribution in the x-axis direction. In particular, in lighting device 200 shown in Figures 6(b) and 6(d), the central region 213a of the light distribution adjustment lens 213 has a meniscus lens shape, so the uniformity of the light distribution is further improved in the region at the right edge of the figure.

[0044] Figure 7 is a graph showing the luminance distribution of lighting devices 100 and 200. Figure 7(a) shows the relative luminance distribution of lighting device 100, and Figure 7(b) shows the relative luminance distribution of lighting device 200. The relative luminance distributions shown in Figures 7(a) and 7(b) were measured at the center of the y-axis direction of the diffusion sheets 114 and 214, as shown by the solid lines in Figures 6(c) and 6(d). As shown in Figures 7(a) and 7(b), both the light distribution adjustment lenses 113 and 213 irradiate with a relative luminance of 0.7 or higher over a wide area, demonstrating that the light distribution is made uniform along the x-axis direction, improving the efficiency of light utilization. In particular, when using the light distribution adjustment lens 213 shown in Figure 7(b), the relative luminance is 0.7 or higher even near both ends, further improving the uniformity of the light distribution and the efficiency of light utilization.

[0045] Figure 8 shows a case where a lenticular portion 213c is provided on the light incident surface of the light distribution adjustment lens 213. Figure 8(a) is a schematic cross-sectional view along a predetermined direction, and Figure 8(b) is a schematic perspective view. As shown in Figure 8, the lenticular portion 213c is formed as a periodic uneven shape in the y-axis direction of the light incident surface, and this uneven shape extends along the x-axis direction. Figure 8 shows an example where the lenticular portion 213c is provided on the light incident surface side, but the lenticular portion 213c may also be provided on the light output surface side, or on both the light incident surface side and the light output surface side. By providing an uneven lenticular portion 213c in the y-axis direction of the light distribution adjustment lens 213, the light distribution in the y-axis direction can be adjusted.

[0046] (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 first and second embodiments, examples were shown where the light incident and light exit surfaces of the central regions 113a, 213a and the side regions 113b, 213b of the light distribution adjustment lenses 113, 213 were smoothly and continuously formed. However, a Fresnel lens shape with multiple sections and steps in the x-axis direction may also be used.

[0047] Even if the light distribution adjustment lenses 113 and 213 are in the shape of Fresnel lenses, by appropriately designing the shapes of the light incident surface and the light exit surface, it is possible to have negative optical power in the central region 113a and 213a and positive optical power in the side regions 113b and 213b. Furthermore, by making the light distribution adjustment lenses 113 and 213 in the shape of Fresnel lenses, it becomes possible to make the lenses thinner.

[0048] (Fourth Embodiment) Next, a fourth embodiment of the present invention will be described. Details that overlap with the first embodiment will be omitted. In the first and second embodiments, the light distribution adjustment lenses 113 and 213 were shown as having a quadrilateral shape with central regions 113a and 213a and side regions 113b and 213b extended in the y-axis direction. However, the light distribution adjustment lenses 113 and 213 may also be circular in shape.

[0049] When the light distribution adjustment lenses 113 and 213 are circular in shape, the area near the center of the circle becomes the central region 113a and 213a and has negative optical power, while the area near the outer edge becomes the side regions 113b and 213b and has positive optical power. In this case, it is preferable to use circular TIR lenses 112 and 212 as well. Alternatively, collimating lenses with a different shape from the TIR lenses 112 and 212 may be used.

[0050] 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]

[0051] 100,200... Lighting devices 111,211…light-emitting elements 112,212…TIR lens 112a...Refracted section 112b...Reflector 112c…Reflective surface 112d...Emission surface 113,213… Light distribution adjustment lens 113a,213a...Central area 113b, 213b… Bilateral regions 113c, 213c... Lenticular section 114,214… Diffusion Sheet 115,215...Display section 213d... range

Claims

1. A plurality of light-emitting parts arranged along a predetermined direction and emitting light, The optical member comprises a light incident surface formed along the predetermined direction and having a light incident surface into which the light is incident, and a light emission surface arranged opposite to the light incident surface, The optical component is A central region located in the center of the predetermined direction, It has both side regions located on both sides of the central region along the predetermined direction, An illumination device characterized in that the central region has negative optical power, and the side regions have positive optical power.

2. A lighting device according to claim 1, The central region has a concave lens shape, which is thin near the center and thick at the edges in the predetermined direction. The illumination device is characterized in that the two side regions have a convex lens shape with thin ends in the predetermined direction.

3. A lighting device according to claim 1, The illumination device is characterized in that the central region has a meniscus lens shape in which the light incident surface and the light output surface are curved in the direction of light incidence in the predetermined direction.

4. A lighting device according to any one of claims 1 to 3, The lighting device is characterized in that the light incident surface or the light emission surface has a lenticular portion formed thereon, in which the irregularities are repeated along a second direction perpendicular to the predetermined direction.

5. A lighting device according to any one of claims 1 to 3, A lighting device characterized by having a collimating lens disposed between the optical element and the light-emitting part.

6. A lighting device according to claim 5, The illumination device is characterized in that the collimating lens is an internal total internal reflection lens having a refractive portion located in the center along a second direction perpendicular to the predetermined direction and reflecting portions located on both sides of the refractive portion.

7. A lighting device according to claim 6, The lighting device is characterized in that the internal total internal reflection lens has the refractive portion and the reflective portion extended in the predetermined direction.

Images