Surface illumination device

Abstract

A planar illumination device (1) according to an embodiment comprises a substrate (3), a plurality of light sources (4) in a first group, and one or more light sources (5) in a second group. Prescribed electrical wiring is applied to the substrate (3). The plurality of light sources (4) in the first group are disposed across substantially the entire surface of the substrate (3). The one or more light sources (5) in the second group are disposed adjacent to the plurality of light sources (4) in the first group within a prescribed region on the substrate (3).

Description

Technical Field

[0001] The present invention relates to a planar lighting device.

Background Art

[0002] There is a cluster meter that integrates various meters required during driving, such as a speedometer, tachometer, and odometer of an automobile (see, for example, Patent Document 1). Such a cluster meter includes a tail part such as a warning light. The tail part is specified in terms of color by regulations, and it is required to be visible in any environment, such as not having insufficient brightness even when direct sunlight hits it.

[0003] Recently, such a cluster meter has come to be capable of highly flexible display using a liquid crystal panel and a backlight. However, since the tail part requires high brightness and high color rendering properties, it is often provided independently of the liquid crystal panel. That is, the tail part is composed of a light-shielding member in which the icon shape to be displayed is cut out, and a single-color LED (Light Emitting Diode) corresponding to the specified display color, which is arranged directly below the light-shielding member.

[0004] Although it is not the tail part of the cluster meter itself, a display device provided with different backlights is disclosed for displaying a fixed pattern such as a touch switch pattern along with a non-fixed pattern such as map information or an in-vehicle camera image (see, for example, Patent Document 2). Alternatively, a warning display for vehicle proximity to the rear may be provided independently. In addition, displays using a liquid crystal panel and a backlight have also come to be used for door mirrors and room back mirrors, and a tail part such as a proximity warning display may be provided in the display device.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] As mentioned above, when the telltale section of a cluster meter is provided separately from the LCD panel and its backlight used for the rest of the display, or when the telltale sections of door mirrors and rearview mirrors are provided separately from the LCD panel and its backlight used for the rest of the display, the structure becomes complex and cost reduction becomes difficult. Furthermore, since the telltale section cannot be used for other displays, the display screen is not fully utilized, and the degree of flexibility in screen display is not increased.

[0007] The present invention has been made in view of the above, and aims to provide a surface illumination device that can be used as a backlight for cluster meters, door mirrors, rearview mirrors, etc., which have a telltale section, and that can meet the requirements for high brightness and high color rendering, such as for telltale sections, has a simple structure, and can effectively utilize the display screen and improve the freedom of screen display. [Means for solving the problem]

[0008] To solve the above-mentioned problems and achieve the objective, a planar illumination device according to one aspect of the present invention comprises a substrate, a plurality of first light sources, and one or more second light sources. , reflector and The plurality of first light sources are arranged in a first region of the substrate. The one or more second light sources are arranged in a second region inside the first region, at positions different from the first light sources. The reflector has a reflective wall. The plurality of first light sources are arranged in a grid. The one or more second light sources are positioned in the center of four adjacent first light sources in the vertical and horizontal directions. The reflective wall includes a first reflective wall that individually surrounds each of the plurality of first light sources in the first region other than the second region, and a second reflective wall that surrounds the second light source and the four first light sources surrounding the second light source as a group in the second region.

[0009] A planar illumination device according to one aspect of the present invention can be used as a backlight for cluster meters, door mirrors, rearview mirrors, etc., which have telltale sections, and can meet the requirements for high brightness and high color rendering, such as telltale sections, has a simple structure, and can enable effective use of the display screen and improve the flexibility of the screen display. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is an external perspective view of a planar illumination device according to one embodiment. [Figure 2] Figure 2 is an exploded perspective view of the main components of a surface illumination device. [Figure 3] Figure 3 is a plan view showing only the substrate and reflector. [Figure 4] Figure 4 is a cross-sectional view of the planar illumination device shown in Figure 1. [Figure 5] Figure 5 shows the effect of adding a second group of light sources and removing some of the reflective walls of the reflector on brightness uniformity, and an example of its improvement. [Figure 6] Figure 6 is an external perspective view showing an example of a planar illumination device with a liquid crystal panel attached. [Figure 7] Figure 7 shows an example of a telltale display on a liquid crystal panel. [Modes for carrying out the invention]

[0011] The following description of a planar illumination device according to an embodiment will be provided with reference to the drawings. However, this embodiment does not limit the present invention. Furthermore, the dimensional relationships and ratios of the elements in the drawings may differ from reality. Even between drawings, there may be differences in dimensional relationships and ratios. Also, the content described in one embodiment or modification generally applies to other embodiments and modifications.

[0012] Figure 1 is an external perspective view of a planar illumination device 1 according to one embodiment. In the figure, for convenience, the longitudinal direction of the planar illumination device 1 is the X-axis direction, the short direction is the Y-axis direction, and the thickness direction is the Z-axis direction, but the orientation during use is arbitrary. Figure 2 is an exploded perspective view of the main part of the planar illumination device 1, and is viewed from the emission surface side, similar to Figure 1. Figure 3 is a plan view showing only the substrate 3 and reflector 6. Figure 4 is an XX cross-sectional view of the planar illumination device 1 in Figure 1, showing a cross-section of a part of the upper side in Figure 1.

[0013] In Figure 1, the surface illumination device 1 has a roughly rectangular (or roughly square) and roughly plate-like outer shape. Its housing consists of a bottom frame (hidden in the background in Figure 1) that houses the substrate and the like, which will be described later, and a top frame 10 that covers the opening side of the bottom frame. The top frame 10 has a roughly rectangular opening 10a that forms an emission surface 1a, so that light is emitted from the inside of the surface illumination device 1 toward the outside. In Figure 1, the internal polarizing reflective film 9 is exposed on the emission surface 1a. When the surface illumination device 1 is used as a backlight for automotive cluster meters, door mirrors, rearview mirrors, etc., the liquid crystal panel and the like are mounted on the side of the emission surface 1a.

[0014] In Figure 2, the planar illumination device 1 consists of a substrate 3 on which multiple (many) light sources 4 of the first group and one or more (six in the illustrated example) light sources 5 of the second group are arranged, a reflector 6, a diffuser 7, a prism sheet 8, and a polarizing reflective film 9 are attached to the bottom frame 2, and the top frame 10 fits onto the outside of the bottom frame 2 to form a cover.

[0015] The bottom frame 2 has a bottom and four side walls provided on the outer circumference of the bottom. The bottom frame 2 is formed from die-cast metal, sheet metal, etc. The substrate 3 is fixed to the inside of the bottom of the bottom frame 2 via a fixing member (not shown) such as double-sided tape.

[0016] On the substrate 3, a first group of light sources 4, such as a plurality (a large number) of LEDs (Light Emitting Diodes), are arranged, for example, in a grid pattern over substantially the entire surface. Further, in a predetermined region on the substrate 3, for example, a part of the upper long side in the figure, one or more light sources 5 of the second group are arranged adjacent to the plurality of light sources 4 of the first group. Each of the light sources 5 of the second group is arranged, for example, at the center of four light sources 4 of the first group arranged at the corners of a virtual rectangle (without interfering with the light sources 4 of the first group). The substrate 3 is provided with electrical wirings for supplying power to each of the light sources 4 and 5. Each of the light sources 4 and 5 can be individually controlled for light emission.

[0017] Between the light sources 4 of the first group on the substrate 3, the back surface of the reflector 6 is fixed via a plurality of strip-shaped fixing members (not shown), such as double-sided tapes, extending in the left-right direction (or the up-down direction) of FIG. 2.

[0018] The reflector 6 reflects the light emitted from the light sources 4 in the first group toward the emission surface side to enhance the luminance. The reflector 6 is surrounded by a frame 6a whose outer edge also serves as a reflecting wall, and its interior is divided into a plurality (a large number) of segments surrounded by four reflecting walls 6b. Most of them are segments (first segments) corresponding to the individual light sources 4 in the first group. The portion corresponding to the tail part such as a warning light is a segment corresponding to four light sources 4 in the first group arranged vertically and horizontally and one light source 5 in the second group at their center. In the segment (second segment) corresponding to the tail part etc., the four reflecting walls 6b between the four light sources 4 in the first group are removed, and the light source 5 in the second group is arranged in the space formed by removing the four reflecting walls 6b. As a result, the four light sources 4 in the first group and the one light source 5 in the second group at the center are surrounded by four reflecting walls ⑥b (one of which is part of the frame 6a). The reflector 6 is manufactured by injection molding of a synthetic resin or the like. In the above embodiment, the entire four reflecting walls 6b are removed, but if a space for arranging the light source 5 in the second group can be secured, a part of each of the four reflecting walls 6b may be left. Also, the arrangement position of the second segment is arbitrary. For example, a first segment may be interposed between adjacent second segments, or a second segment may be provided at a position away from the inside of the frame 6a. When the overall shape of the reflector 6 is irregular in plan view, the second segment may be provided only in the rectangular portion excluding the irregular portion. Also, a plurality of second segments may correspond to one icon.

[0019] Also, the plurality of light sources 4 in the first group are elements that emit light from the side surface, and the one or more light sources 5 in the second group are elements that emit light from the top surface. That is, the light emitted from the side surface of the light source 4 in the first group is reflected by the reflecting wall 6b of the reflector 6 and emitted in the substantially normal direction of the emission surface. Also, the light emitted from the top surface of the light source 5 in the second group is directly emitted in the substantially normal direction of the emission surface.

[0020] The diffuser 7, positioned on the output side of the reflector 6, reduces brightness unevenness by diffusing the light that passes through it. On the input side of the diffuser 7 (the side with light sources 4 and 5, and the side with the reflector 6), there are multiple tiny pyramidal prisms, each with its vertices (vertices not touching the base) facing the light sources 4 and 5 and its base facing the output side. The pyramidal prisms may be provided across the entire surface of the diffuser 7, or they may be provided only in the area where the second group of light sources 5 are located, corresponding to the telltales. In addition to the diffuser 7, an optical sheet with multiple pyramidal prisms may be positioned on the input side of the diffuser 7.

[0021] The pyramid prism diffuses the light emitted from the side of the first group of light sources 4 and reflected by the reflective wall 6b of the reflector 6, as well as the light emitted from the top surface of the second group of light sources 5, thereby reducing brightness unevenness. Depending on the specifications regarding brightness uniformity, the diffuser 7 does not necessarily need to have a pyramid prism, and a prism of a different shape than a pyramid may also be used.

[0022] The prism sheet 8, positioned on the output side of the diffuser 7, improves brightness by adjusting the light distribution.

[0023] The polarizing reflective film 9, positioned on the output side of the prism sheet 8, allows polarization in a predetermined direction to pass through and reflects polarization in a direction perpendicular to it, and is aligned with the polarization direction of the externally mounted liquid crystal panel.

[0024] A top frame 10 is positioned on the exit side of the polarizing reflective film 9, and the top frame 10 is fixed to the bottom frame 2. The top frame 10 is formed from die casting, sheet metal, or the like.

[0025] Although the diagram shows the planar illumination device 1 as being planar, the planar illumination device 1 may also be curved. In this case, for example, the bottom frame 2, substrate 3, reflector 6, and top frame 10 are formed in a curved shape, and the diffuser 7, prism sheet 8, and polarizing reflective film 9 are deformed into a curved shape during assembly.

[0026] Figure 5 shows the effect of adding the second group of light sources 5 and removing part of the reflective wall of the reflector 6 on brightness uniformity and an example of improvement. The top row (a) is a plan view showing an example of the brightness distribution of the first comparative example planar illumination device 1' in which the second group of light sources is not provided and part of the reflective wall of the reflector has not been removed. In this case, there is a slight decrease in brightness in the surrounding area, but brightness uniformity is maintained in most areas.

[0027] Figure (b) in the second row from the top is a plan view showing an example of the luminance distribution in a second comparative example planar illumination device 1'' in which a second group of light sources is provided and a portion of the reflector's reflective wall is removed, when only the first group of light sources is lit. In this case, luminance unevenness occurs near the upper long side due to the removal of the reflector's reflective wall, but since the number and arrangement of the first group of light sources are the same as in the first comparative example, the effect is small. The second comparative example, in which a second group of light sources is provided and a portion of the reflector's reflective wall is removed, has slightly inferior luminance uniformity compared to the embodiments shown in Figures 1 to 4, but it can be adopted as another embodiment.

[0028] The third image from the top, (c), is a plan view showing an example of the luminance distribution in a second comparative example planar illumination device 1'', in which a second group of light sources is provided and a portion of the reflector's reflective wall is removed, when both the first group of light sources and the second group of light sources are lit. In this case, in addition to the smooth luminance distribution in (b), a peaky luminance distribution due to the ignition of the second group of light sources can be observed, and high luminance can be expected in the telltale area.

[0029] The fourth row from the top, (d), is a plan view showing an example of the luminance distribution in the planar lighting device 1 of the embodiments in Figures 1 to 4, when only the first group of light sources 4 is lit. In this case, compared to the luminance distribution in (b), the luminance unevenness is reduced due to the diffusion effect of the pyramidal prism of the diffuser 7.

[0030] The fifth row from the top, (e), is a plan view showing an example of the luminance distribution in the planar lighting device 1 of the embodiments shown in Figures 1 to 4, when the first group of light sources 4 and the second group of light sources 5 are lit. In this case, compared to the luminance distribution in (c), the peaky luminance distribution is eliminated due to the diffusion effect of the pyramidal prism of the diffuser 7. Therefore, the use of a diffuser with a pyramidal prism is effective when uniformity is prioritized over the magnitude of luminance.

[0031] Figure 6 is an external perspective view showing an example of a surface illumination device 1 with a liquid crystal panel 20 mounted on it. The front side of the figure is the display surface 20a of the liquid crystal panel 20. The liquid crystal panel 20 can be either a color liquid crystal panel or a monochrome liquid crystal panel.

[0032] Figure 7 shows an example of a telltale section 20b displayed on a liquid crystal panel 20. When a color liquid crystal panel is used as the liquid crystal panel 20, the first group of light sources 4 and the second group of light sources 5 can emit white or pseudo-white light. In this case, the shapes and colors of the various warning lights on the telltale section 20b are represented by images reproduced by the color liquid crystal panel, and the various warning lights are displayed by illuminating them from behind with white or pseudo-white light from the second group of light sources 5. Furthermore, the brightness of the warning lights can be further increased by simultaneously illuminating not only the second group of light sources 5 but also the surrounding first group of light sources 4. Even when using a color liquid crystal panel, the brightness of the warning lights can be further increased by illuminating the second group of light sources 5 in a color corresponding to the displayed icon.

[0033] Furthermore, at least one of the light sources 4 and 5 in the first and second groups may be a light source that combines red, green, and blue (RGB) monochromatic LEDs into a single unit. LEDs that integrate each of the RGB light-emitting chips into a single package are commercially available, and if the RGB light-emitting chips are lit simultaneously, white light is obtained, and if either of the RGB light-emitting chips is lit, monochromatic light of any RGB color is obtained. By changing the ratio of the light-emitting amounts of the RGB chips, monochromatic light of any color can be obtained. This makes it possible to unify the elements of the light source.

[0034] Furthermore, if a monochrome liquid crystal panel is used as the liquid crystal panel 20, the first group of light sources 4 may emit light in white, pseudo-white, or a predetermined color, and the second group of light sources 5 may emit light in a color (including white and pseudo-white) corresponding to the displayed icon. In this case, the shapes of the various warning lights on the telltail section 20b are represented by images reproduced by the monochrome liquid crystal panel, and the colors of the various warning lights are represented by the color of the illumination provided from behind by the second group of light sources 5. In this case as well, at least one of the first and second group of light sources 4 and 5 may be a light source that combines red, green, and blue (RGB) mono-color LEDs into a single light source.

[0035] Furthermore, regardless of whether a color or monochrome liquid crystal panel is used as the liquid crystal panel 20, any image (speedometer, tachometer, map image, television image, etc.) can be displayed across the entire surface of the display surface 20a, including the telltale section 20b. In this case, illumination from the surface illumination device 1 is provided by the first group of light sources 4. In addition, icons corresponding to warning lights, etc., in a predetermined color can be displayed on the telltale section 20b, superimposed on images in other parts. To ensure the visibility of the icons, when displaying icons superimposed on various meters, etc., icons can be placed on a black background, the display of various meters, etc. in the overlapping area can be turned off, or the telltale section 20b and various meters, etc. can be displayed alternately. Furthermore, when used as a cluster meter, in addition to the display on the telltale section 20b, various meters necessary for driving, such as the speedometer and tachometer, can be displayed on the parts other than the telltale section 20b. Furthermore, when used as a door mirror or rearview mirror, the camera image can be displayed on the parts other than the telltale section 20b, showing the rear and side views, in addition to the display on the telltale section 20b.

[0036] Although embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications are possible without departing from the spirit of the invention.

[0037] As described above, the planar illumination device according to the embodiment comprises a substrate with predetermined electrical wiring, a first group of multiple light sources arranged over substantially the entire surface of the substrate, and a second group of one or more light sources arranged adjacent to the first group of multiple light sources within a predetermined area of ​​the substrate. This makes it usable as a backlight for cluster meters with telltale sections, door mirrors, rearview mirrors, etc., and can meet the requirements for high brightness and high color rendering, such as telltale sections, while having a simple structure, enabling effective use of the display screen, and improving the flexibility of screen display.

[0038] In other words, since the telltale area is illuminated primarily by the second group of light sources and the area outside the telltale area is illuminated by the first group of light sources, it can be used as a backlight for cluster meters, door mirrors, rearview mirrors, etc. that have telltale areas. Furthermore, since the second group of light sources is provided separately from the first group of light sources, the brightness of the second group of light sources can be easily increased, and it is also possible to emit light in any color, thus meeting the high brightness and high color rendering requirements for telltale areas. In addition, since the first group of light sources and the second group of light sources are arranged on a single substrate, the structure is simple and low cost can be achieved. Moreover, since the entire screen can be used for areas other than the telltale area by the first group of light sources, the display screen can be used effectively. Furthermore, since the telltale area and the area outside are displayed by a liquid crystal panel provided on the output side, there is no need for light-shielding members with cutouts for telltale icon shapes, thus improving the flexibility of screen display.

[0039] Furthermore, the multiple light sources of the first group are arranged in a grid pattern over substantially the entire surface of the substrate, and one or more light sources of the second group are arranged between adjacent light sources of the first group. As a result, the multiple light sources of the first group can be arranged in the same way as in the conventional technology without a telltale section, and thus the function of a telltale section or the like can be performed while maintaining the function of a telltale section or the like as a backlight.

[0040] Furthermore, the system includes a reflector having reflective walls surrounding each of the multiple light sources in the first group, the multiple light sources in the first group arranged in a grid pattern over substantially the entire surface of the substrate, and the light sources in the second group are positioned in the center of four adjacent light sources in the first group, with at least a portion of the four reflective walls between the four light sources in the first group with the light sources of the second group positioned in the center being removed. This makes it possible to add additional light sources in the second group while improving brightness with the reflector.

[0041] Furthermore, the multiple light sources in the first group are elements that emit light from the side, and one or more light sources in the second group are elements that emit light from the top. This allows for light emission depending on the presence or absence of the reflector's reflective wall. That is, the light sources in the first group emit light toward the reflective wall, and the light sources in the second group, which are not surrounded by the reflective wall, emit light toward the exit side, thereby effectively obtaining light distribution in a direction approximately normal to the light source.

[0042] Furthermore, an optical sheet with multiple tiny pyramidal prisms, each with its vertex facing the light source, is provided on the emission side. This reduces brightness unevenness caused by the addition of one or more light sources in the second group and brightness unevenness caused by the removal of the reflector's reflective wall through the diffusion effect of the pyramidal prisms, thereby improving brightness uniformity.

[0043] Furthermore, a color liquid crystal panel is arranged on the output side, and the multiple light sources of the first group emit light in white or pseudo-white, while one or more light sources of the second group emit light in white, pseudo-white, or a predetermined color corresponding to an icon. As a result, the required light emission color in the telltale section, etc., is achieved by the color emission of the color liquid crystal. In addition, the brightness in the telltale section, etc., can be increased by emitting light not only from the light sources of the second group but also from the surrounding light sources of the first group. One or more light sources of the first group and the second group may be light-emitting light sources consisting of a single red, green, or blue monochromatic LED.

[0044] Furthermore, when illuminating a predetermined area of ​​the substrate, one or more light sources of the second group arranged in the predetermined area are activated, or multiple light sources of the first group arranged in the predetermined area and one or more light sources of the second group arranged in the predetermined area are activated. This allows for the display of telltales and the like by the light emitted from the second group of light sources, and the brightness can be increased by adding the light sources of the first group.

[0045] Furthermore, a monochrome liquid crystal panel is arranged on the output side, and the multiple light sources of the first group emit light in white, pseudo-white, or a predetermined color, while one or more light sources of the second group emit light in a color corresponding to the icon displayed in the predetermined area. As a result, the emission color required for the telltale section, etc., is achieved by the emission color of the light sources of the second group. One or more light sources of the first group and the second group may be light sources consisting of a single red, green, or blue monochromatic LED.

[0046] Furthermore, the light sources of the first group and / or the second group are light-emitting light sources that combine red, green, and blue monochromatic LEDs into a single unit. This allows for the unification of the light source elements.

[0047] Furthermore, the surface illumination device according to this embodiment can be applied not only to warning displays on cluster meters, but also, for example, to warning lights on door mirrors and rearview mirrors. It can also be applied to blind spot warnings (warning when a vehicle is approaching from the rear or side).

[0048] Furthermore, the present invention is not limited to the embodiments described above. Configurations that appropriately combine the above-described components are also included in the present invention. Moreover, further effects and modifications can be easily derived by those skilled in the art. Therefore, broader aspects of the present invention are not limited to the embodiments described above, and various modifications are possible. [Explanation of symbols]

[0049] 1 Planar illumination device, 1a Emitting surface, 2 Bottom frame, 3 Substrate, 4, 5 Light source, 6 Reflector, 6a Frame, 6b Reflective wall, 7 Diffuser, 8 Prism sheet, 9 Polarizing reflective film, 10 Top frame, 10a Aperture, 20 Liquid crystal panel, 20a Display surface, 20b Telltale section

Claims

1. circuit board and A plurality of first light sources arranged in the first region of the substrate, Within the second region inside the first region, one or more second light sources are arranged at positions different from the first light source, A reflector having a reflective wall, Equipped with, The plurality of first light sources are arranged in a grid pattern, The one or more second light sources are arranged in the center of four first light sources that are adjacent to each other vertically and horizontally. The aforementioned reflective wall is In the region of the first region other than the second region, a first reflective wall surrounds each of the plurality of first light sources individually, The second region includes a second reflective wall that surrounds the second light source and the four first light sources surrounding the second light source as a group, A surface illumination device.

2. The plurality of first light sources are arranged in a grid pattern in the first region. The one or more second light sources are arranged between the plurality of first light sources arranged in the second region. The planar illumination device according to claim 1.

3. At least a portion of the four reflective walls between the four first light sources, with the second light source positioned in the center, The planar illumination device according to claim 1 or 2.

4. The aforementioned plurality of first light sources are elements that emit light from the side, The aforementioned one or more second light sources are elements that emit light from the top surface. The planar illumination device according to claim 1 or 2.

5. An optical sheet is provided on the output side of the substrate, having multiple minute pyramidal prisms whose vertices face the substrate side. The planar illumination device according to claim 1 or 2.

6. A color LCD panel is positioned on the output side. The plurality of first light sources emit light in white or pseudo-white, The one or more second light sources emit light in white, pseudo-white, or a predetermined color corresponding to an icon. The planar illumination device according to claim 1 or 2.

7. When illuminating the second region of the substrate, the emission of light from one or more second light sources arranged in the second region, or the emission of light from the plurality of first light sources arranged in the second region and one or more second light sources arranged in the second region, The planar illumination device according to claim 6.

8. A monochrome LCD panel is positioned on the output side. The plurality of first light sources emit light in white, pseudo-white, or a predetermined color. The one or more second light sources emit light in a color corresponding to the icon displayed in the second region. The planar illumination device according to claim 1 or 2.

9. The first light source and / or the second light source is a light-emitting light source that combines red, green, and blue monochromatic LEDs into one unit. The planar illumination device according to claim 1 or 2.

10. The one or more second light sources are arranged in a position different from the first light source within the second region corresponding to the telltale portion inside the first region. The planar illumination device according to claim 1 or 2.

11. The one or more second light sources are located in a region inside the first region, and within the second region which is located in a part of the first region, they are positioned at a different location from the first light source. The planar illumination device according to claim 1 or 2.

12. The first light source and the second light source have different wavelengths of emitted light. The planar illumination device according to claim 1 or 2.

13. circuit board and A first group of multiple light sources arranged over substantially the entire surface of the substrate, One or more light sources of a second group are arranged adjacent to the plurality of light sources of the first group within a predetermined area which is a part of substantially the entire surface of the substrate, A reflector having a reflective wall, Equipped with, The multiple light sources of the first group are arranged in a grid pattern over substantially the entire surface of the substrate. The second group of light sources is positioned in the center of the four light sources of the first group that are adjacent to each other vertically and horizontally. The aforementioned reflective wall is In the area of ​​the arrangement region of the multiple light sources of the first group, excluding the area of ​​the arrangement region of the second group of light sources, a first reflective wall individually surrounds each of the multiple light sources of the first group, In the arrangement region of the second group of light sources, a second reflective wall is included that surrounds the second group of light sources and the four light sources surrounding the second group of light sources as a single group, A surface illumination device.

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