Lighting device and display device

Abstract

To provide a lighting device that can improve luminance.SOLUTION: A lighting device includes: a substrate; a light emitting body installed on the substrate; a first coating layer provided in an outer periphery of the light emitting body and on the substrate; and a second coating layer laminated on the first coating layer. A material constituting the first coating layer and a material constituting the second coating layer have the same reflectance.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a lighting device and a display device. [Background technology]

[0002] An illumination device (light source module) is disclosed that includes a substrate (printed circuit board), a light-emitting body (light-emitting chip) mounted on the substrate, and a lens portion (optical lens) arranged above the light-emitting body (for example, Patent Document 1).

[0003] In a lighting device, light emitted from the light-emitting body either enters the lens portion directly and is diffused from the lens portion to the upper side of the light-emitting body, or is reflected by the substrate, enters the lens portion, and is diffused from the lens portion to the upper side of the light-emitting body.

[0004] In Patent Document 1, the substrate includes a coating layer (insulating coating layer) and a reflection adjustment pattern having reflection characteristics different from those of the coating layer. In Patent Document 1, the reflection adjustment pattern can control the amount of light reflected by the substrate and incident on the upper lens portion of the light emitter. Therefore, in Patent Document 1, the uniformity of the brightness of the light emitted from the light emitter can be improved. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2015-149472 A Summary of the Invention [Problem to be solved by the invention]

[0006] The lighting device disclosed in Patent Document 1 can improve the uniformity of luminance by using the reflection adjustment pattern, but the reflection adjustment pattern also reduces the luminance.

[0007] An object of the present disclosure is to provide an illumination device and a display device capable of improving brightness. [Means for solving the problem]

[0008] An illumination device according to one embodiment of the present disclosure includes a substrate, a light-emitting body provided on the substrate, a first coating layer that surrounds the light-emitting body and is laminated on the substrate, and a second coating layer that is laminated on the first coating layer, the first coating layer and the second coating layer being made of materials having the same reflectance.

[0009] A display device according to one embodiment of the present disclosure includes an illumination device comprising a substrate, an illuminant provided on the substrate, a first coating layer around the periphery of the illuminant and laminated on the substrate, and a second coating layer laminated on the first coating layer, the first coating layer and the second coating layer being made of materials having the same reflectance. [Brief description of the drawings]

[0010] [Figure 1] 1 is a perspective view showing a schematic configuration of a display device according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is an exploded perspective view showing a schematic configuration of the display device shown in FIG. [Diagram 3] FIG. 2 is a plan view illustrating an example of a lighting device included in the display device according to the embodiment of the present disclosure. [Figure 4] FIG. 4 is a plan view illustrating an example of the lighting device illustrated in FIG. [Diagram 5] 5 is a VV cross-sectional view of the lighting device shown in FIG. [Figure 6] FIG. 11 is a plan view illustrating an example of an illumination device according to a first modified example of the embodiment of the present disclosure. [Figure 7] 7 is a cross-sectional view taken along line VII-VII of the illumination device shown in FIG. 6. [Figure 8] FIG. 11 is a plan view illustrating an example of an illumination device according to a second modified example of the embodiment of the present disclosure. [Figure 9]9 is a cross-sectional view of the lighting device 20 shown in FIG. 8 taken along line IX-IX. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, the embodiments and modifications of the present disclosure will be described with reference to the drawings. In the following, the same or corresponding components are denoted by the same reference numerals throughout all the drawings, and their repeated description will be omitted. In addition, the embodiments and modifications described below are merely examples of the present disclosure, and the present disclosure is not limited to the embodiments and modifications. Even if the embodiments and modifications are not limited to the embodiments and modifications, various modifications can be made according to the design, etc., as long as they do not deviate from the technical idea of ​​the present disclosure.

[0012] (display device) A display device 1 according to an embodiment of the present disclosure will be described with reference to Figures 1 and 2. Figure 1 is a perspective view showing a schematic configuration of the display device 1 according to an embodiment of the present disclosure. Figure 2 is an exploded perspective view showing the schematic configuration of the display device 1 shown in Figure 1.

[0013] As shown in Figures 1 and 2, the display device 1 according to an embodiment of the present disclosure has an overall horizontally elongated, roughly rectangular shape, and has a configuration in which a backlight chassis 15 having an illumination device 20 (see Figure 3 described below) including a plurality of light-emitting elements 22, such as mini LED chips, is provided on the back side of a display panel 11 that displays images.

[0014] In the following description, the longitudinal direction of the display device 1 is defined as the left-right direction, the lateral direction of the display device 1 as the up-down direction, and the thickness direction of the display device 1 as the front-rear direction (see Figs. 1 and 2). Of the left-right direction of the display device 1, the left side when viewed from the front side is defined as the left direction, and the right side is defined as the right direction. Of the front-rear direction when viewed from the front side, the front side (near side) of the display device 1 is defined as the front direction, and the back side (rear side) is defined as the rear direction. Also, in the display device 1, the bottom side is defined as the downward direction, and the opposite side is defined as the upward direction. However, these directions are defined for the convenience of explanation, and do not limit the directions of the display device 1 when in use.

[0015] As shown in FIG. 2, the display device 1 includes a display panel 11, an adhesive layer 12, a frame 13, an optical sheet 14, a diffusion plate 10, and a backlight chassis 15.

[0016] A circuit board 21 (substrate) on which a plurality of light emitters 22 are mounted is disposed on the front side of the backlight chassis 15 as shown in Fig. 3. Fig. 3 is a plan view showing a schematic example of an illumination device 20 included in the display device 1 according to an embodiment of the present disclosure. The illumination device 20 of the present disclosure is realized by the plurality of light emitters 22 and the circuit board 21. A detailed configuration of the illumination device 20 will be described later.

[0017] The circuit board 21 is fixed to the front side of the backlight chassis 15 by mounting members (screws, adhesive tape, etc.) not shown. The circuit board 21 may be a printed circuit board on which a plurality of light emitters 22 are mounted. The plurality of light emitters 22 are arranged at equal intervals in a matrix on the circuit board 21 as shown in FIG. 3. Specifically, the plurality of light emitters 22 are arranged at predetermined intervals in the row and column directions on the circuit board 21. The number and intervals of the light emitters 22 are not particularly limited and are appropriately determined based on the size and display performance of the display panel 11, the performance (brightness) of the light emitters 22, and the like. The plurality of light emitters 22 are arranged so that their light emission surfaces are approximately parallel to each other with respect to the display surface of the display panel 11, and are configured so that the optical axis (center axis) of the light emitted from each of the plurality of light emitters 22 is approximately perpendicular to the display surface of the display panel 11.

[0018] The light emitting body 22 is covered by a lens portion 23 that diffuses the light emitted from the light emitting body 22. The lens portion 23 can be, for example, a so-called potting lens formed by piling up and coating urethane resin or the like so as to cover the light emitting body 22.

[0019] Moreover, a coating layer 24 is provided on the surface of the circuit board 21 so as to surround the periphery of the light emitter 22. The coating layer 24 reflects the light emitted from the light emitter 22 toward the rear side, in other words, the light toward the circuit board 21, toward the front side, in other words, the display panel 11 side. The coating layer 24 may be made of, for example, a solder resist. The coating layer 24 includes at least two layers, a first coating layer 24a and a second coating layer 24b, and the material constituting the first coating layer 24a and the material constituting the second coating layer 24b have the same reflectance (see FIG. 5 described later). That is, the material constituting the first coating layer 24a and the material constituting the second coating layer 24b only need to have the same ratio of the reflected light flux to the light flux incident thereon, and the first coating layer 24a and the second coating layer 24b may be made of the same material, or may be made of different materials as long as they have the same reflectance. The surfaces of the first coating layer 24a and the second coating layer 24b have a good reflectance and a hue such as white. The reflectance of each of the first coating layer 24a and the second coating layer 24b is preferably 95% or more. In the lighting device 20 according to the embodiment of the present disclosure, the coating layer 24 is composed of two layers, the first coating layer 24a and the second coating layer 24b, but may be three or more layers.

[0020] The diffusion plate 10 diffuses the light emitted from the light emitters 17 toward the optical sheet 14. The optical sheet 14 is disposed on the front side of the diffusion plate 10.

[0021] The optical sheet 14 collects the light diffused by the diffusion plate 10 and emits the light toward the display panel 11. Although Fig. 2 and Fig. 3 show the configuration of the display device 1 including one optical sheet 14, a plurality of optical sheets 14 may be provided.

[0022] In the display device 1, the frame 13 is provided on the sides of the respective side end faces of the backlight chassis 15, the diffusion plate 10, the optical sheet 14, and the display panel 11. Note that the above-mentioned side end faces include not only the left and right side parts of each of the backlight chassis 15, the diffusion plate 10, the optical sheet 14, and the display panel 11, but also the upper and lower side parts.

[0023] The display panel 11 is composed of a glass substrate, liquid crystal, etc., and functions as an image display portion of the display device 1. The sides of the display panel 11 are adhered and fixed to the frame 13 via an adhesive layer 12 such as double-sided tape. The frame 13 and the display panel 11 are adhered to each other by bonding dissimilar members. For this reason, the adhesive layer 12 is made thick and elastic to prevent the two from coming apart due to differences in thermal expansion between the two, etc.

[0024] (Lighting equipment) The configuration of the lighting device 20 will be described with reference to Fig. 4 and Fig. 5 in addition to Fig. 3 described above. Here, for convenience, the configuration of the lighting device 20 will be described focusing on one light emitter 22 included in the lighting device 20. Fig. 4 is a plan view showing an example of the lighting device 20 shown in Fig. 3. Fig. 4 shows an enlarged state of part A in the lighting device 20 shown in Fig. 3. Fig. 5 is a VV cross-sectional view of the lighting device 20 shown in Fig. 4. In Fig. 4, the second area β where the second coating layer 24b is laminated on the first coating layer 24a and the first area α where only the first coating layer 24a is laminated are distinguished by hatching in the dot pattern. The dot pattern of the second area β is denser than the dot pattern of the first area α.

[0025] 5, the lighting device 20 includes a circuit board 21, a light emitter 22 mounted on the circuit board 21 via solder 25, a first coating layer 24a provided on the circuit board 21 around the periphery of the light emitter 22, and a second coating layer 24b laminated on the first coating layer 24a. The material constituting the first coating layer 24a and the material constituting the second coating layer 24b have the same reflectance.

[0026] In this manner, the lighting device 20 has a configuration in which the first coating layer 24a and the second coating layer 24b, each having a high reflectance, are laminated on the circuit board 21. This makes it possible to prevent the light emitted from the light emitter 22 from being absorbed by the circuit board 21.

[0027] In particular, since the first coating layer 24a and the second coating layer 24b made of materials having the same reflectance are laminated, the light that is not completely reflected by the second coating layer 24b can be reflected by the first coating layer 24a. That is, most of the light emitted from the light emitter 22 (about 95%) is reflected by the second coating layer 24b, and most of the light that passes through the second coating layer 24b (about 95%) is reflected by the first coating layer 24a.

[0028] Therefore, the lighting device 20 can improve the amount of light emitted toward the display panel 11 compared to a lighting device configuration that does not have the first coating layer 24a and the second coating layer 24b, or a lighting device configuration that has only the first coating layer 24a.

[0029] Therefore, the display device 1 including the illumination device 20 as a backlight can achieve improved display quality.

[0030] In addition, the solder 25 that joins the light-emitting body 22 onto the circuit board 21 and the first coating layer 24a that is provided on the circuit board 21 may be provided so as to be in contact with the surface of the circuit board 21, or, if the circuit board 21 is made of an insulating material, a conductive wiring layer (not shown) may be provided on the surface of the circuit board 21, and the solder 25 and the first coating layer 24a may be provided so as to be in contact with this wiring layer.

[0031] As shown in FIG. 4, when the circuit board 21 is viewed from the light-emitting body 22 side in plan view, the first area α where only the first coating layer 24a is provided is different from the second area β where the second coating layer 24b is laminated on the first coating layer 24a. More specifically, the first coating layer 24a is laminated on the entire surface of the circuit board 21 except for the light-emitting body 22. In contrast, the second coating layer 24b is laminated on the entire surface of the circuit board 21 except for the light-emitting body 22 and an area spaced a predetermined distance from the light-emitting body 22. That is, the first area α is an area spaced a predetermined distance from the light-emitting body 22. The second area β is an area where the second coating layer 24b is laminated. In other words, the second area β is located farther away from the light-emitting body 22 than the first area α.

[0032] In this way, the second coating layer 24b is laminated on the first coating layer 24a such that the second area β is located farther from the light emitter 22 than the first area α. This makes it possible to prevent a deviation in the positional relationship between the first coating layer 24a and the second coating layer 24b due to manufacturing errors or the like, and to prevent the second coating layer 24b from being laminated closer to the light emitter 22 than the first coating layer 24a.

[0033] This prevents the second coating layer 24b from being laminated closer to the light emitting body 22 than the first coating layer 24a, thereby narrowing the area in which the solder 25 can be mounted and reducing the amount of solder 25 that can be applied.

[0034] In this way, it is possible to prevent the amount of solder 25 applied from being reduced, and therefore the occurrence of mounting defects of the light emitting body 22 on the circuit board 21 can be suppressed.

[0035] In the lighting device 20 according to the embodiment of the present disclosure, when the positional deviation occurring during the manufacturing of the first coating layer 24a and the second coating layer 24b is very small and need not be considered, the area where the first coating layer 24a is laminated may coincide with the area where the second coating layer 24b is laminated. In other words, the entire surface of the circuit board 21 may be the second area β.

[0036] (First Modification) Next, the configuration of the lighting device 20 according to the first modified example of the embodiment of the present disclosure will be described with reference to Figs. 6 and 7. The lighting device 20 according to the first modified example of the embodiment is similar to the lighting device 20 according to the embodiment, except that the first range α and the second range β are different. That is, the lighting device 20 according to the first modified example of the embodiment has a range in which the first coating layer 24a is laminated on the circuit board 21 similar to the lighting device 20 according to the embodiment, but the range in which the second coating layer 24b is laminated on the first coating layer 24a is different. With respect to the other configurations, the lighting device 20 according to the first modified example of the embodiment is similar to the lighting device 20 according to the embodiment. For this reason, the same members are denoted by the same reference numerals, and their description will be omitted.

[0037] Fig. 6 is a plan view showing an example of the lighting device 20 according to the first modified example of the embodiment of the present disclosure. Fig. 6 shows an enlarged state of the portion A in the lighting device 20 shown in Fig. 3, similar to Fig. 4. Note that Fig. 6 uses dot-shading similar to Fig. 4 to clearly distinguish between the second area β where the second coating layer 24b is laminated on the first coating layer 24a and the first area α where only the first coating layer 24a is laminated. Fig. 7 is a cross-sectional view taken along the line VII-VII of the lighting device 20 shown in Fig. 6.

[0038] 7, the lighting device 20 according to the first modification includes a circuit board 21, a light emitter 22 mounted on the circuit board 21 via solder 25, a first coating layer 24a provided on the circuit board 21 around the periphery of the light emitter 22, and a second coating layer 24b laminated on the first coating layer 24a. The material constituting the first coating layer 24a and the material constituting the second coating layer 24b have the same reflectance.

[0039] 6, when the circuit board 21 is viewed from the light emitter 22 side, the first area α where only the first coating layer 24a is provided is different from the second area β where the second coating layer 24b is laminated on the first coating layer 24a. More specifically, the first coating layer 24a is laminated on the entire surface of the circuit board 21 except for the light emitter 22. In contrast, the second coating layer 24b is laminated on the circuit board 21 within the area where the lens portion 23 is provided and excluding the light emitter 22. In addition, in consideration of the possibility that the positional relationship between the first coating layer 24a and the second coating layer 24b may be shifted due to manufacturing errors, etc., the area where the second coating layer 24b is laminated further excludes an area spaced a predetermined distance from the light emitter 22. In other words, the first area α is the area spaced a predetermined distance from the light emitter 22 and the outside of the area where the lens portion 23 is provided on the circuit board 21. The second area β is the area where the second coating layer 24b is laminated.

[0040] Here, the number of times that the light emitted from the light emitter 22 is reflected by the circuit board 21 is greater in the area where the lens portion 23 is provided than in the area where the lens portion 23 is not provided on the circuit board 21. This is because some of the light is reflected by the lens portion 23 and heads toward the circuit board 21.

[0041] In the lighting device 20 according to the first modification example, the second coating layer 24b is laminated only in the range where the lens portion 23 is provided when the circuit board 21 is viewed in a plan view. Therefore, in the circuit board 21, it is possible to efficiently suppress the absorption of light by the circuit board 21 in a range where the number of times the light is reflected is large.

[0042] As described above, the lighting device 20 according to the first modification example of the embodiment is advantageous in that the cost can be reduced because the range in which the second coating layer 24b is laminated can be reduced as compared with the lighting device 20 according to the embodiment.

[0043] Further, the display device 1 including the lighting device 20 according to the first modification example of the embodiment may be configured to further include a reflection sheet (not shown) that covers the surface of the circuit board 21 between the diffusion plate 10 and the backlight chassis 15. That is, the reflection sheet has an opening at a position corresponding to the lens portion 23 provided on the circuit board 21, and the light emitting surface of the light emitter 22 and the tip of the lens portion 23 are arranged so as to protrude forward from the opening. In this way, in the case of the configuration further including the reflection sheet, the reflectivity of light is improved by laminating the first coating layer 24a and the second coating layer 24b in the range where the lens portion 23 is provided on the surface of the circuit board 21, and in the range where the lens portion 23 is not provided, the reflectivity of light can be improved by the first coating layer 24a and the reflection sheet.

[0044] (Second Modification Example) Next, the configuration of the lighting device 20 according to the second modified example of the embodiment of the present disclosure will be described with reference to Figs. 8 and 9. The lighting device 20 according to the second modified example of the embodiment is similar to the lighting device 20 according to the embodiment, except that the first range α and the second range β are different. That is, in the lighting device 20 according to the second modified example of the embodiment, the range in which the first coating layer 24a is laminated on the circuit board 21 is similar to that of the lighting device 20 according to the embodiment, but the range in which the second coating layer 24b is laminated on the first coating layer 24a is different. In other respects, the lighting device 20 according to the second modified example of the embodiment is similar to the lighting device 20 according to the embodiment. For this reason, the same members are denoted by the same reference numerals, and their description will be omitted.

[0045] Fig. 8 is a plan view showing an example of an illumination device 20 according to a second modified example of an embodiment of the present disclosure. Fig. 8 shows an enlarged state of part A in the illumination device 20 shown in Fig. 3, similar to Fig. 4. Note that Fig. 8 uses dot-pattern shading similar to Fig. 4 to clearly distinguish between a second area β where the second coating layer 24b is laminated on the first coating layer 24a and a first area α where only the first coating layer 24a is laminated. Fig. 9 is a cross-sectional view taken along line IX-IX of the illumination device 20 shown in Fig. 8.

[0046] 9, the lighting device 20 according to the second modification includes a circuit board 21, a light emitter 22 mounted on the circuit board 21 via solder 25, a first coating layer 24a provided on the circuit board 21 around the periphery of the light emitter 22, and a second coating layer 24b laminated on the first coating layer 24a. The material constituting the first coating layer 24a and the material constituting the second coating layer 24b have the same reflectance.

[0047] Incidentally, the amount of light emitted from the light-emitting body 22 decreases as the distance from the light-emitting body 22 increases. However, due to the influence of light emitted from other light-emitting bodies adjacent to the light-emitting body 22, there are also areas far from the light-emitting body 22 where the amount of light is relatively increased.

[0048] Furthermore, depending on the shape of the lens portion 23 that covers the light emitter 22, there are regions on the circuit board 21 where the light reflected by the lens portion 23 is concentrated in a large amount and regions where this is not the case.

[0049] In this way, since the amount of light changes depending on the distance from the light emitter 22, the presence or absence of other adjacent light emitters, the shape of the lens portion 23, etc., the amount of light reflected by the circuit board 21 becomes uneven.

[0050] Therefore, in the lighting device 20 according to the second modification of the present disclosure, the range in which the illuminance is relatively small on the surface of the circuit board 21 is defined as the second range β. More specifically, the range in which the illuminance on the surface of the circuit board 21 illuminated by the light emitted from the light emitter 22 is smaller than the average is defined as the second range β, and the range in which the illuminance is equal to or greater than the average is defined as the first range α. Note that the illuminance refers to the amount of light incident on the circuit board 21 per unit area.

[0051] 8 and 9, in lighting device 20 according to the second modification, second range β is the entire surface of circuit board 21 excluding light emitter 22 and the position where the outer periphery of lens portion 23 contacts circuit board 21 and a predetermined area therearound. This is because light reflected by lens portion 23 is easily focused in the position where the outer periphery of lens portion 23 contacts circuit board 21 and the predetermined area therearound, resulting in an area with higher illuminance than average.

[0052] Furthermore, in consideration of the possibility that a deviation in the positional relationship between the first coating layer 24a and the second coating layer 24b may occur due to manufacturing errors or the like, the second range β is set to a range that further excludes an area spaced a predetermined distance from the light emitter 22.

[0053] That is, the first coating layer 24a is laminated on the entire surface of the circuit board 21 excluding the light emitter 22. On the other hand, the second coating layer 24b is laminated on the first coating layer 24a in an area excluding the positions where the outer peripheries of the light emitter 22 and the lens portion 23 contact the circuit board 21 and predetermined areas in the vicinity of the positions, and an area spaced a predetermined distance from the light emitter 22.

[0054] In the illumination device 20 according to the second modification, the second range β in the circuit board 21 is a range in which the illuminance on the surface of the circuit board 21 illuminated by the light emitted from the light emitter 22 is smaller than the average. That is, the second range β is a range in which the amount of light emitted from the light emitter 22 on the surface of the circuit board 21 is relatively smaller than other ranges. Therefore, it is possible to increase the reflectance of light in the range in which the illuminance is small on the surface of the circuit board 21. Therefore, it is possible to suppress unevenness in the amount of light reflected by the circuit board 21. In addition, it is possible to efficiently suppress light absorption by the circuit board 21 in the region in which the illuminance is small on the circuit board 21, thereby improving the luminance of the display device 1.

[0055] In the illumination device 20 according to the second modification, the second range β is the entire surface of the circuit board 21 excluding the light-emitting body 22, an area spaced a predetermined distance from the light-emitting body 22, and a predetermined area near the position where the outer periphery of the lens portion 23 contacts the circuit board 21. However, the second range β is not limited to this range. It is preferable to configure the second range β so that it is appropriately set to a range in which the illuminance on the circuit board 21 is smaller than the average, depending on the distance from the light-emitting body 22 to other light-emitting bodies adjacent thereto, the shape of the lens portion 23, and the like.

[0056] For example, the illumination device 20 may be configured to examine the illuminance distribution on the surface of the circuit board 21 in advance, and set the second range β based on the examination results. In this manner, when the illumination distribution on the surface of the circuit board 21 is examined in advance and the second range β is set, unevenness in the amount of light reflected by the circuit board 21 can be further suppressed. [Explanation of symbols]

[0057] 1 Display device 11 Display Panel 15 Backlight chassis 17 Luminous Object 20 Lighting Equipment 21 Circuit Board 22 Luminous object 23 Lens section 24 Coating Layer 24a First coating layer 24b Second coating layer α First range β 2nd range

Claims

1. A substrate; A light emitter provided on the substrate; a first coating layer disposed on the substrate and surrounding the light emitter; a second coating layer laminated on the first coating layer, The first coating layer and the second coating layer are made of materials having the same reflectivity.

2. The lighting device of claim 1, wherein when the substrate is viewed in a plane from the light-emitting body side, a first area in which only the first coating layer is laminated is different from a second area in which the second coating layer is laminated on the first coating layer.

3. The lighting device according to claim 2 , wherein the second range is located farther from the light emitter than the first range.

4. Further comprising a lens portion provided on the substrate so as to cover at least the light emitter, The lighting device according to claim 2 , wherein the second range is within a range in which the lens portion is provided on the substrate.

5. The lighting device according to claim 2 , wherein the second range is a range in which illuminance on the substrate caused by the light emitted from the light emitter is smaller than an average.

6. The lighting device according to claim 1 , wherein the first coating layer and the second coating layer each have a surface reflectance of 95% or more.

7. A display device comprising the illumination device according to claim 1.

Images