WO2024034458A1

WO2024034458A1 - Optical member and illumination device

Info

Publication number: WO2024034458A1
Application number: PCT/JP2023/028084
Authority: WO
Inventors: 圭一郎野村; 隆延豊嶋
Original assignee: 株式会社小糸製作所
Priority date: 2022-08-10
Filing date: 2023-08-01
Publication date: 2024-02-15
Also published as: JP2024025239A

Abstract

Provided are an optical member and an illumination device that make it possible to achieve a uniform light allocation distribution in a predetermined direction, and improved light utilization efficiency. An optical member (113) comprises a light incident surface on which light is incident, and a light exit surface disposed opposite the light incident surface. The light incident surface and the light exit surface are formed along a predetermined direction. The optical member (113) includes a central region (113a) positioned at the center in the predetermined direction, and side regions (113b) that are positioned on both sides of the central region (113a) along the predetermined direction. The central region (113a) has a negative optical power, and the side regions (113b) have a positive optical power.

Description

Optical components and lighting devices

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

A light source device using a lens that utilizes total internal reflection, a so-called TIR lens, is conventionally known. A TIR lens includes a refracting section located in the center and a reflecting section located around the refracting section. For example, Patent Document 1 is known as a document disclosing a light source device using a TIR lens.

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) each having a function of a collimating lens arranged on the plurality of light sources, and a plurality of optical means. It includes a plurality of lens arrays arranged on the exit surface side of the lens, forming a plurality of different light distribution patterns. The optical unit disclosed in Patent Document 1 is mainly used as a vehicle lamp.

Japanese Patent Application Publication No. 2021-189306

A light source device as described above may be used, for example, as a lighting device (backlight) for a head-up display (hereinafter sometimes referred to as "HUD") mounted on a vehicle or the like. A light source device used in a HUD is particularly required to be bright and without unevenness, that is, to have high brightness and a uniform brightness distribution. In other words, high luminous flux utilization efficiency and appropriate light distribution are required. The above-mentioned TIR lens can condense the light emitted from the light emitting element that has a large angle (directivity angle) with the emission axis and spreads outward, so it may be used as an optical means suitable for this purpose. many.

FIG. 9 is a schematic diagram illustrating an overview of a lighting device using a conventional TIR lens and light irradiation. As shown in FIG. 9, the conventional lighting device includes a plurality of light emitting elements 1, a TIR lens 2, a light distribution adjusting lens 3, a diffusion sheet 4, and a display section 5. The arrows in the figure schematically indicate the traveling direction of light emitted from each light emitting element 1.

A plurality of light emitting elements 1 are arranged along the lateral direction (predetermined direction) in the figure, and irradiate light in the direction of the TIR lens 2. The TIR lens 2 is formed to extend in the lateral direction in the figure, and collimates the light from the light emitting element 1 in a direction (second direction) perpendicular to the paper surface of FIG. The light distribution adjustment lens 3 refracts the light from the light emitting element 1 via the TIR lens 2 and irradiates it onto the diffusion sheet 4 and the display section 5 . The diffusion sheet 4 transmits the irradiated light while diffusing or scattering it. The display unit 5 is a part of a liquid crystal display device or the like that transmits light and displays an image, and displays an image using light diffused by the diffusion sheet 4 from the back side.

In the conventional illumination device shown in FIG. 9, as an example, a concave lens is used as the light distribution adjustment lens 3, the light incidence surface and the light exit surface of which are concave over the entire area in the lateral direction (predetermined direction) in the figure. Thereby, the irradiation range of the light transmitted through the TIR lens 2 can be expanded along a predetermined direction, and a wide range on the diffusion sheet 4 and the display section 5 can be well irradiated.

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, so that a part of the light is transferred to the diffusion sheet 4. There is also a problem in that the light propagates outside the range of the display section 5, resulting in a decrease in the utilization efficiency of the emitted light from the light emitting element 1.

The present invention has been made in view of the above conventional problems, and provides an optical member and a lighting device that can make the light distribution uniform along a predetermined direction and improve the light utilization efficiency. The purpose is to

In order to solve the above problems, an optical member of the present invention has a light entrance surface into which light enters, and a light exit surface disposed opposite to the light entrance surface, the light entrance surface and the light exit surface are arranged opposite to the light entrance surface. The surface is formed along a predetermined direction, and has a central region located in the center of the predetermined direction, and both side regions located on both sides of the central region along the predetermined direction, and the central region is It has a negative optical power, and the both side regions have a positive optical power.

In such an 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 both side regions, so that light is expanded in the vicinity of the central region. At the same time, it is possible to collect light within the irradiation range in both side areas, make the light distribution uniform along a predetermined direction, and improve the light utilization efficiency.

Further, 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 ends in the predetermined direction, and the both side regions have a convex lens shape that is thin at the ends in the predetermined direction.

Further, in one aspect of the present invention, the central region has a meniscus lens shape in which the light entrance surface and the light exit surface are curved in the direction of incidence of the light in the predetermined direction.

Furthermore, in one aspect of the present invention, a lenticular portion in which concavities and convexities are repeated along two axial directions perpendicular to the predetermined direction is formed on the light entrance surface or the light exit surface.

In order to solve the above problems, the lighting device of the present invention includes the optical member according to any one of the above aspects, a plurality of light emitting parts arranged on the light incident surface side, and a combination of the optical member and the light emitting part. It is characterized by having a collimating lens disposed in between.

Further, in one aspect of the present invention, the plurality of light emitting units are arranged along the predetermined direction, and the collimating lens is a refracting lens arranged at the center along a second direction perpendicular to the predetermined direction. This is a total internal reflection lens comprising a refracting section and a reflecting section disposed on both sides of the refracting section.

Furthermore, in one aspect of the present invention, the total internal reflection lens has the refracting section and the reflecting section extending in the predetermined direction.

According to the present invention, it is possible to provide an optical member and a lighting device that can make the light distribution uniform along a predetermined direction and improve the light utilization efficiency.

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. It is a schematic cross-sectional view. FIG. 2 is a diagram schematically explaining the outline of a lighting device 200 according to a second embodiment, and is a schematic cross-sectional view along a predetermined direction. 3(a) shows a light distribution adjusting lens 113, and FIG. 3(b) shows a light distribution adjusting lens 213. FIG. 4(a) shows the light distribution adjusting lens 113, and FIG. 4(b) shows the light distribution adjusting lens 213. FIG. There is. FIG. 6 is a diagram schematically showing a range 213d having the maximum thickness in the light distribution adjustment lens 213. 6(a) shows a virtual image obtained by the lighting device 100, FIG. 6(b) shows a virtual image obtained by the lighting device 200, and FIG. 6(c) shows the brightness distribution of the lighting device 100, and FIG. 6(d) shows the brightness distribution of the lighting device 200. 7(a) shows the relative brightness distribution of the lighting device 100, and FIG. 7(b) shows the relative brightness distribution of the lighting device 200. FIG. 8(a) is a schematic cross-sectional view along a predetermined direction, and FIG. 8(b) is a schematic perspective view. be. FIG. 2 is a schematic diagram illustrating an overview of a lighting device using a conventional TIR lens and light irradiation.

(First embodiment)
Embodiments of the present invention will be described in detail below with reference to the drawings. Identical or equivalent constituent elements, members, and processes shown in each drawing are denoted by the same reference numerals, and redundant explanations will be omitted as appropriate. FIG. 1 is a diagram schematically explaining the outline of a lighting device 100 according to the present embodiment, FIG. 1(a) is a schematic cross-sectional view along a predetermined direction, and FIG. FIG. In FIG. 1A, 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). Further, in FIG. 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 paper surface corresponds to the x-axis direction. As shown in FIGS. 1A and 1B, 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 section 115.

The light emitting element 111 is an electronic component that is mounted on a mounting board (not shown) on which wiring is formed and emits light in a predetermined color when a current is supplied by a drive circuit. A plurality of light emitting elements 111 are arranged along the x-axis direction (predetermined direction), and correspond to a light emitting section in the present invention. Here, the term "arrangement along the x-axis direction" includes a case where it can be considered to be substantially in the x-axis direction, and may be an inclination of several degrees, a staggered arrangement, or the like. Although the specific structure of the light emitting element 111 is not limited, it may be an LED package that combines a light emitting diode (LED) that emits primary light and a wavelength conversion member that converts the wavelength of a part of the primary light into secondary light. can be used. Further, the material of the light emitting diode is not limited either, and known materials and structures can be used. As an example, a GaN-based LED that emits blue light can be used. Further, the material of the wavelength conversion member is not limited, and for example, a YAG-based phosphor material that emits yellow light when excited by blue light can be used. Note that in this embodiment, the light emitting elements 111 are arranged in one row, but may be arranged in two or more rows. Further, the light emitting element 111 is not limited to an LED, but may be a semiconductor laser or the like.

The TIR lens 112 is arranged between the plurality of 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. Further, the TIR lens 112 includes a refraction section 112a disposed at the center and reflection sections 112b disposed on both sides of the refraction section 112a in the y-axis direction (second direction) orthogonal to the x-axis direction. . Further, the reflecting portion 112b has a reflecting surface 112c whose outer surface in the y-axis direction is inclined. Further, the surfaces of the refracting section 112a and the reflecting section 112b that face the light distribution adjusting lens 113 have an output surface 112d. A part of the light emitted from the light emitting element 111 enters the refracting section 112a, is refracted according to the refractive index difference, passes through the refracting section 112a, and is irradiated onto the light distribution adjustment lens 113 from the output surface 112d. . Further, the other part of the light emitted from the light emitting element 111 enters the reflection part 112b from the inner surface provided at the boundary between the refraction part 112a and the reflection part 112b, is totally reflected by the reflection surface 112c, and is reflected from the output surface. The light is irradiated onto the light distribution adjustment lens 113 from 112d.

As shown in FIG. 1(b), the TIR lens 112 focuses the light emitted from the light emitting element 111 having a large directivity angle in the y-axis direction by total internal reflection (TIR). It has a function as a collimating lens that emits parallel light or light close to parallel light (hereinafter, both are collectively referred to as "substantially parallel light"). Therefore, the TIR lens 112 corresponds to a total internal reflection lens in the present invention. The light emitted from the light emitting element 111 with a large directivity angle is, for example, light that spreads outward in the y-axis direction in FIG. 1(b). That is, the TIR lens 112 can efficiently collect the light emitted from the light emitting element 111.

The light distribution adjustment lens 113 is arranged on the exit surface 112d side of the TIR lens 112, and has a light entrance surface into which light enters, and a light exit surface arranged opposite to the light entrance surface. The light distribution adjustment lens 113 is formed to extend along the x-axis direction, and has a central region 113a and both side regions 113b. Furthermore, on the light incident surface side of the light distribution adjustment lens 113, a lenticular portion 113c is formed with repeated concavities and convexities along the y-axis direction. Although this embodiment shows an example in which the lenticular portion 113c is provided on the light incident surface side, the lenticular portion 113c may be provided on the light exit surface side, or the lenticular portion 113c may be omitted.

The central region 113a is located at the center in the x-axis direction and has negative optical power. Further, the both-side regions 113b are located on both sides of the central region 113a, and have positive optical power. Although the boundaries between the central region 113a and both side regions 113b may not be clearly defined in terms of shape, there is a region where light emitted from the light exit surface expands when parallel light enters from the light entrance surface. This corresponds to the central region 113a, and the regions where light is focused correspond to both side regions 113b. Therefore, the light distribution adjusting lens 113 corresponds to an optical member in the present invention. Although the specific shapes of the central region 113a and the light distribution adjustment lens 113 are not limited, the central region 113a has a concave lens shape that is thin near the center and thick at the edges, as shown in FIG. A combination of convex lens-shaped both side regions 113b can be used.

The TIR lens 112 and the light distribution adjustment lens 113 have the function of guiding the light emitted from the light emitting element 111 to the illumination area of the illumination target. In this embodiment, the back surface of the diffusion sheet 114 (the surface on the light emitting element 111 side) is used as an example of the illumination area. However, the area to be illuminated may be determined by taking into consideration the specifications of the light source device, and 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, resin such as acrylic resin, glass, or the like.

The diffusion sheet 114 is an optical member that is disposed between the light distribution adjustment lens 113 and the display section 115 and transmits the 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 output it to the display section 115, so that the display section 115 is more uniformly illuminated. The specific material and structure of the diffusion sheet 114 are not limited, and a substantially plate-like sheet in which light-scattering particles are dispersed in resin may be used, or a sheet having a structure in which minute irregularities are formed on the surface of a resin material may be used. You can also use it as

The display unit 115 is a device that displays an image in response to an image signal from a control unit (not shown). Although the specific configuration of the display section 115 is not limited, a liquid crystal display device or the like that transmits light from the back side (light emitting element 111 side) and displays an image can be used.

As shown in FIGS. 1(a) and 1(b), the light emitted from the light emitting element 111 enters the TIR lens 112 while expanding in the x-axis direction and the y-axis direction. Further, as shown in FIG. 1(a), in the TIR lens 112, the structure of the refracting part 112a and the reflecting part 112b extends along the x-axis direction, so that the light spread in the x-axis direction remains at the exit surface. The light is magnified and irradiated from 112d toward the light distribution adjustment lens 113. The light incident on the central region 113a of the light distribution adjustment lens 113 receives negative optical power and is refracted in the direction of further expansion, and is irradiated in a wide range near the center of the diffusion sheet 114 and the display section 115. . The light incident on both side regions 113b of the light distribution adjustment lens 113 receives positive optical power and is refracted in the direction of condensation, and is condensed or parallel light toward the vicinity of both sides of the diffusion sheet 114 and the display section 115. irradiated.

Further, as shown in FIG. 1(b), since the TIR lens 112 is provided with a refracting section 112a and a reflecting section 112b in the y-axis direction, it functions as a collimating lens in the y-axis direction, and the output surface 112d Light is emitted as substantially parallel light from. The light collimated in the y-axis direction is refracted by the lenticular portion 113c provided on the light incidence surface of the light distribution adjustment lens 113, and then irradiated onto the diffusion sheet 114.

Since the plurality of light emitting elements 111 are arranged in the x-axis direction, the intensity of light is relatively high near the center of the x-axis where the light from the plurality of light emitting elements 111 overlaps and reaches the light emitting elements 111 at the ends. The intensity of light tends to be relatively small near both ends of the x-axis, where only light from the center reaches. However, in the illumination device 100 of this embodiment, negative optical power is given to the light in the central region 113a of the light distribution adjustment lens 113, and the light incident on the center of the x-axis is expanded, thereby changing the light distribution of the output light. Can be expanded. Furthermore, positive optical power is given to the light in both regions 113b of the light distribution adjustment lens 113, and the light incident on both ends of the x-axis is focused, thereby increasing the amount of light irradiated within the range of the diffusion sheet 114. Can be done. Therefore, the light distribution of the light irradiated onto the diffusion sheet 114 via the light distribution adjustment lens 113 is made uniform along the x-axis direction, and the light utilization efficiency is improved.

As described above, in the light distribution adjustment lens 113 and the lighting 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 has positive optical power in both side regions 113b. By having the desired power, the light is expanded in the vicinity of the central region 113a, while the light is concentrated within the irradiation range in the both side regions 113b, making the light distribution uniform along the x-axis direction, and increasing the light utilization efficiency. It becomes possible to improve the performance.

(Second embodiment)
Next, a second embodiment of the present invention will be described using FIG. 2. Description of contents that overlap with those of the first embodiment will be omitted. FIG. 2 is a diagram schematically explaining the outline of the lighting device 200 according to the present embodiment, and is a schematic cross-sectional view along a predetermined direction. As shown in FIG. 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 section 215. The structure of the refracting section 112a and the reflecting section 112b of the TIR lens 212 along the y-axis direction is the same as that of the first embodiment, and the explanation thereof will be omitted.

In the lighting device 200 of this embodiment as well, the light distribution adjustment lens 213 is formed to extend along the x-axis direction, and has a central region 213a and both side regions 213b. Further, the central region 213a has negative optical power, and both side regions 113b have positive optical power. As shown in FIG. 2, in this embodiment, the central region 213a has a light incident surface and a light exit surface curved in the direction of the light emitting element 211 (light incident direction) in the x-axis direction, and has a meniscus lens shape. ing.

Also 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 both side regions 213b. This makes it possible to expand the light in the vicinity of the central region 213a and gather the light within the irradiation range in the both side regions 213b, making the light distribution uniform along the x-axis direction and improving the light utilization efficiency. becomes.

(Explanation of uniform light distribution)
FIG. 3 is a schematic diagram illustrating the progression of light in the

illumination devices

100, 200, in which FIG. 3(a) shows the light distribution adjustment lens 113, and FIG. 3(b) shows the light distribution adjustment lens 213. . FIGS. 3A and 3B schematically illustrate the path of light that receives negative optical power in the vicinity of the boundary between the

central regions

113a and 213a and the both-

side regions

113b and 213b. In the

central region

113a, 213a and both

side regions

113b, 213b of the light

distribution adjustment lenses

113, 213, the incident light receives negative optical power and positive optical power, respectively, and the light distribution is changed along the x-axis direction. Similar to the first embodiment, it is possible to make the light uniform and improve the light usage efficiency.

As shown in FIG. 3A, in the light distribution adjustment lens 113 of the illumination device 100, the central region 113a has a concave lens shape, and the both side regions 113b have a convex lens shape, so that the light incident surface and the light The change in curvature of the exit surface increases. In particular, in the vicinity of the both side regions 113b of the central region 113a, the negative optical power is greater than in the center of the central region 113a, and light traveling outward from the diffusion sheet 114 is generated. In particular, it is difficult to appropriately set the traveling direction of light incident from the light emitting elements 111 disposed on opposite sides of the central region 113a so that it falls within the diffusion sheet 114.

As shown in FIG. 3(b), in the light distribution adjustment lens 213 of the illumination device 200, the central region 213a has a meniscus lens shape, and the both side regions 213b have a convex lens shape, so that the boundary between the two regions forms a light incident surface. The change in curvature of the light exit surface can be made smaller than that of the light distribution adjustment lens 113. Therefore, the negative optical power in the central region 213a is approximately the same throughout the region, and light traveling outward from the diffusion sheet 214 can be suppressed. In particular, even for light incident from the light emitting elements 211 arranged on the opposite side with the central region 213a in between, the traveling direction of the light can be set to fall within the diffusion sheet 214, so that the light enters the diffusion sheet 214. Further uniformity can be achieved by increasing the amount of light.

FIG. 4 is a schematic diagram illustrating the progress of light near the boundary where the optical power changes between positive and negative. FIG. 4(a) shows the light distribution adjustment lens 113, and FIG. 4(b) shows the light distribution adjustment lens 113. 213 is shown. In the light distribution adjustment lens 113, as shown in FIG. 4(a), a part of the light obliquely incident on the end of the light incident surface in the central region 113a is strongly affected by negative optical power and is shifted along the x-axis. The light may spread outward in the direction and be emitted from the light emitting surfaces of both side regions 113b. Since the both side regions 113b receive strong positive optical power, the light travels further outward in the x-axis direction.

On the other hand, in the light distribution adjustment lens 213, as shown in FIG. The light reaches the side closer to the central region 213a on the light emitting surface of 213b and is emitted. Therefore, the positive optical power received by both side regions 213b becomes weaker than that of the light distribution adjustment lens 113, and the angle of the light directed outward in the x-axis direction can be made smaller and placed within the range of the diffusion sheet 214.

FIG. 5 is a diagram schematically showing a range 213d having the maximum thickness in the light distribution adjustment lens 213. In FIG. 5, only a portion having optical power is shown as the light distribution adjusting lens 213, but a holding member for appropriately holding and fixing may be formed integrally with the light distribution adjusting lens 213. When the holding member is formed integrally with the light distribution adjusting lens 213, the thickness of the light distribution adjusting lens 213 indicates the thickness of a portion that has optical power and contributes to refraction of light. The light distribution adjustment lens 213 has a central area 213a shaped like a meniscus lens and both side areas 213b shaped like a convex lens, and has a maximum thickness in the z-axis direction at any position in the x-axis direction. . The position where this light distribution adjustment lens 213 has the maximum thickness is defined as the thickest position. When the center in the x-axis direction is expressed as 0% and both ends as 100%, it is preferable that the thickest position exists within a range 213d of 5% or more and 95% or less. When the thickest position is smaller than the range 213d, the expansion of light by the central region 213a becomes insufficient. Furthermore, if the thickest position is larger than the range 213d, the light condensation at both side regions 213b becomes insufficient, and the amount of light reaching the outside of the diffusion sheet 214 increases. Although FIG. 5 shows only the light distribution adjusting lens 213 in which the central region 213a is shaped like a meniscus lens, the same applies to the light distribution adjusting lens 113 in which the central region 113a is shaped like a concave lens. Further, although FIG. 5 shows an example of a bilaterally symmetrical shape as the light distribution adjustment lens 213, it may be bilaterally asymmetrical, and the maximum thickness and the thickest position in the left and right ranges 213d may be different.

FIG. 6 is a diagram showing virtual image display and brightness in the

lighting devices

100 and 200, FIG. 6(a) shows a virtual image obtained by the lighting device 100, and FIG. 6(b) shows a virtual image obtained by the lighting device 200. 6(c) shows the brightness distribution of the lighting device 100, and FIG. 6(d) shows the brightness distribution of the lighting device 200. The virtual images and brightness cross-sections shown in FIGS. 6(a) to 6(d) are obtained by using the

illumination devices

100 and 200 as backlights of the HUD device, and using the

lighting devices

100 and 200 as backlights of the HUD device. ) seen from the left end. As shown in FIGS. 6(a) to 6(d), it can be seen that light is irradiated with a uniform light distribution in the x-axis direction in both the virtual image and the virtual image brightness. In particular, in the lighting device 200 shown in FIGS. 6(b) and 6(d), the central region 213a of the light distribution adjustment lens 213 has a meniscus lens shape, so that the uniformity of the light distribution is more improved in the rightmost region in the figure. are doing.

7 is a graph showing the brightness distribution of the

lighting devices

100 and 200, FIG. 7(a) shows the relative brightness distribution of the lighting device 100, and FIG. 7(b) shows the relative brightness distribution of the lighting device 200. There is. The relative brightness distributions shown in FIGS. 7(a) and 7(b) were measured at the center of the

diffusion sheets

114 and 214 in the y-axis direction, as shown by solid lines in FIGS. 6(c) and 6(d). As shown in FIGS. 7(a) and 7(b), both the light

distribution adjustment lenses

113 and 213 emit light over a wide range with a relative brightness of 0.7 or more, and the light is distributed along the x-axis direction. It can be seen that the distribution is made more uniform and the efficiency of light use is improved. In particular, when the light distribution adjustment lens 213 shown in FIG. 7(b) is used, it is possible to irradiate with a relative brightness of 0.7 or more even near both ends, making the light distribution more uniform and making better use of light. Can improve efficiency.

FIG. 8 is a diagram showing a case where a lenticular portion 213c is provided on the light incidence surface of the light distribution adjustment lens 213, FIG. 8(a) is a schematic cross-sectional view along a predetermined direction, and FIG. FIG. As shown in FIG. 8, the lenticular portion 213c is formed as a periodic uneven shape in the y-axis direction of the light incident surface, and the uneven shape extends along the x-axis direction. Although FIG. 8 shows an example in which the lenticular portion 213c is provided on the light incident surface side, the lenticular portion 213c may be provided on the light emitting surface side, or may be provided on both the light incident surface side and the light emitting surface side. good. By providing the 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.

(Third embodiment)
Next, a third embodiment of the present invention will be described. Description of contents that overlap with those of the first embodiment will be omitted. In the first embodiment and the second embodiment, examples are shown in which the light incidence and light exit surfaces of the

central regions

113a, 213a and both

side regions

113b, 213b are formed smoothly and continuously as the light

distribution adjusting lenses

113, 213. However, a Fresnel lens shape may be used in which the lens is divided into a plurality of sections in the x-axis direction and steps are provided.

Even if the light

distribution adjustment lenses

113, 213 are shaped like Fresnel lenses, by appropriately designing the shapes of the light entrance surface and the light exit surface, the

central regions

113a, 213a have negative optical power, and both

side regions

113b, 213b can have positive optical power. Further, by forming the light

distribution adjusting lenses

113 and 213 into a Fresnel lens shape, it is possible to reduce the thickness.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described. Description of contents that overlap with those of the first embodiment will be omitted. In the first embodiment and the second embodiment, the light

distribution adjusting lenses

113, 213 are shown as having a quadrilateral shape in which the

central regions

113a, 213a and both

side regions

113b, 213b are extended in the y-axis direction. The

lenses

113 and 213 may have a circular shape.

When the light

distribution adjustment lenses

113, 213 are circular, the vicinity of the center of the circle becomes the

central region

113a, 213a and has negative optical power, and the vicinity of the outer periphery becomes both

side regions

113b, 213b and has positive optical power. It will have the following. In this case, it is preferable to use

circular TIR lenses

112 and 212 as well. Further, a collimating lens having a shape different from that of the

TIR lenses

112 and 212 may be used.

The present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. are also included within the technical scope of the present invention.

This international application claims priority based on Japanese patent application No. 2022-128517, which is a Japanese patent application filed on August 10, 2022. The entire contents of No. 1 are incorporated by reference into this international application.

The above descriptions of specific embodiments of the invention have been presented for purposes of illustration. They are not intended to be exhaustive or to limit the invention to the precise forms described. It will be obvious to those skilled in the art that many modifications and variations are possible in light of the above description.

100,200...Illumination device 111,211...Light emitting element 112,212...TIR lens 112a...Refraction part 112b...Reflection part 112c...Reflection surface 112d...

Emission surface

113, 213...Light

distribution adjustment lens

113a, 213a...

Central region

113b, 213b...both

side regions

113c, 213c...

lenticular portions

114, 214...

diffusion sheets

115, 215...display portion 213d...range

Claims

It has a light entrance surface into which light enters, and a light exit surface disposed opposite to the light entrance surface,
The light entrance surface and the light exit surface are formed along a predetermined direction,
a central region located at the center in the predetermined direction;
and both side regions located on both sides of the central region along the predetermined direction,
An optical member characterized in that the central region has negative optical power, and the both side regions have positive optical power.
The optical member according to claim 1,
The central region has a concave lens shape that is thin near the center and thick at the ends in the predetermined direction;
The optical member is characterized in that the both side regions have a convex lens shape with thin end portions in the predetermined direction.
The optical member according to claim 1,
The optical member is characterized in that the central region has a meniscus lens shape in which the light incident surface and the light exit surface are curved in the light incident direction in the predetermined direction.
The optical member according to any one of claims 1 to 3,
The optical member is characterized in that the light entrance surface or the light exit surface is formed with a lenticular portion in which concavities and convexities are repeated along a second direction orthogonal to the predetermined direction.
The optical member according to any one of claims 1 to 3,
a plurality of light emitting parts arranged on the light incidence surface side;
An illumination device comprising a collimating lens disposed between the optical member and the light emitting section.
The lighting device according to claim 5,
The plurality of light emitting parts are arranged along the predetermined direction,
The collimating lens is a total internal reflection lens that includes a refracting section disposed at the center along a second direction orthogonal to the predetermined direction, and reflecting sections disposed on both sides of the refracting section. lighting equipment.
7. The lighting device according to claim 6,
The illumination device is characterized in that the total internal reflection lens has the refraction section and the reflection section extending in the predetermined direction.