Luminaire and display device

Abstract

To provide a luminaire capable of easily fixing a reflector to a circuit board and capable of suppressing light leakage, and to provide a display device including the same.SOLUTION: A luminaire includes: a circuit board on which a plurality of light sources 5a are mounted; a lattice reflector 6 for surrounding each of the plurality of light sources 5a; and a double-sided tape, and illuminates an object by the plurality of light sources 5a which can be controlled by local dimming. The reflector 6 includes: a plurality of first portions 61 extending in an X direction and arranged with intervals in a Y direction; and a plurality of second portions 62 positioned between the adjacent first portions 61, extending in the Y direction, and arranged with intervals in the X direction. The double-sided tape is a belt-like shape extending in the X direction, and is positioned between a surface facing the circuit board in the first portion 61 and the circuit board. On the surface facing the circuit board in the second portion 62, a recessed part 62a is formed recessed in a direction being separated from the circuit board.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present disclosure relates to an illumination device and a display device including the same. [Background technology]

[0002] For example, Patent Document 1 describes a display device that is capable of controlling the lighting of multiple light sources mounted on a circuit board and illuminating a liquid crystal panel from behind using local dimming. Local dimming is a technology that controls the brightness of the light source for illuminating the liquid crystal panel for each of multiple areas (dimming zones). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-104781 Summary of the Invention [Problem to be solved by the invention]

[0004] In this type of device, a lattice-shaped reflector that surrounds each of the multiple light sources (i.e., divides the dimming zones) is fixed to a circuit board. There are various methods for fixing the reflector to the circuit board, but there is room for improvement in a method for simply fixing the reflector to the circuit board while preventing light from a light source located in a dimming zone from leaking into another dimming zone (light leakage).

[0005] The present disclosure has been made in consideration of the above-described situation, and aims to provide an illumination device that can easily fix a reflector to a circuit board and suppress light leakage, and a display device including the same. [Means for solving the problem]

[0006] In order to achieve the above object, a lighting device according to a first aspect of the present disclosure comprises: A circuit board on which a plurality of light sources are mounted; a lattice-shaped reflector surrounding each of the plurality of light sources; a double-sided tape for fixing the reflector to the circuit board; and The reflector is a first portion extending in a first direction and arranged at intervals in a second direction intersecting the first direction; a plurality of second portions disposed between adjacent first portions and extending in the second direction and spaced apart in the first direction; the double-sided tape has a strip shape extending in the first direction and is positioned between the circuit board and a surface of the first portion facing the circuit board; A recess recessed in a direction away from the circuit board is formed on a surface of the second portion facing the circuit board.

[0007] In order to achieve the above object, a display device according to a second aspect of the present disclosure includes: The illumination device and a liquid crystal panel as the target are provided. Effect of the Invention

[0008] According to the present disclosure, a reflector can be easily fixed to a circuit board, and light leakage can be suppressed. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic configuration diagram of a display device according to an embodiment of the present disclosure. [Diagram 2] FIG. [Diagram 3] 3 is a cross-sectional view of the lighting device according to the embodiment taken along line II in FIG. 2. [Figure 4] FIG. 2 is a front perspective view of the circuit board and the double-sided tape according to the embodiment; [Diagram 5] 3 is a cross-sectional view of the lighting device according to the embodiment taken along line II-II of FIG. 2. [Figure 6] FIG. 2 is a rear perspective view of the reflector and the light source according to the embodiment. [Figure 7] FIG. 6 is a cross-sectional view showing a reflector according to a comparative example, the cross-sectional view corresponding to FIG. 5 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] An embodiment of the present disclosure will be described with reference to the drawings.

[0011] The display device 100 shown in Fig. 1 includes a liquid crystal panel 1, an illumination device 2 (backlight unit) that illuminates the liquid crystal panel 1 from behind, an optical sheet 3 provided between the liquid crystal panel 1 and the illumination device 2, a housing 4 that houses these, and a control unit (not shown). The liquid crystal panel 1 is, for example, a TFT (Thin Film Transistor) type. The optical sheet 3 is a diffusion plate or the like. The display device 100 is, for example, a meter provided on an instrument panel of a vehicle.

[0012] In the following, each configuration of the display device 100 may be described using the mutually orthogonal X, Y, and Z axes as appropriate. The Z axis is along the vertical direction in FIG. 1. The direction in which the arrows indicating each of the X, Y, and Z axes point is the + (plus) direction of each axis, and the opposite direction is the - (minus) direction. For example, the +Z direction of a certain configuration corresponds to the front side, and the -Z direction corresponds to the back side.

[0013] As shown in appropriate drawings of FIGS. 2 to 6, the lighting device 2 includes a circuit board 5, a reflector 6, and a double-sided tape .

[0014] The circuit board 5 is a PCB (Printed Circuit Board). For example, the main surface of the circuit board 5 is parallel to the XY plane. A plurality of light sources 5a arranged in each of the X and Y directions are mounted on the circuit board 5. For example, the light sources 5a are LEDs (Light-Emitting Diodes).

[0015] The multiple light sources 5a can be controlled by a control unit (not shown) through local dimming. That is, the brightness of the light source 5a is controlled for each dimming zone. In this embodiment, one light source 5a is provided for one dimming zone. The control unit (not shown) is electrically connected to each of the liquid crystal panel 1 and the circuit board 5, and is configured with a microcontroller that controls the operation of the liquid crystal panel 1 and the multiple light sources 5a.

[0016] The reflector 6 is formed in a lattice shape surrounding each of the multiple light sources 5a. The reflector 6 is formed in white color, for example, from a resin. As shown mainly in FIG. 6, in the reflector 6 formed in a lattice shape, a portion extending in the X direction is defined as a first portion 61, and a portion located between adjacent first portions 61 is defined as a second portion 62 extending in the Y direction. In other words, the reflector 6 has the first portion 61 and the second portion 62.

[0017] Specifically, the first portions 61 extend in the X direction (an example of a first direction) and are arranged at intervals in the Y direction (an example of a second direction). The second portions 62 are located between adjacent first portions 61, extend in the Y direction, and are arranged at intervals in the X direction.

[0018] Here, adjacent first portions 61 and adjacent second portions 62 between them form one surrounding wall 60 surrounding one light source 5a (see the dashed line portion in FIG. 2). In other words, the surrounding wall 60 defines a dimming zone. The surrounding wall 60 defining one dimming zone reflects light emitted by the light source 5a located therein and guides the light to the liquid crystal panel 1. The reflector 6, in which a plurality of such surrounding walls 60 are arranged in a matrix, guides the light from the light source 5a for each dimming zone toward the liquid crystal panel 1.

[0019] The double-sided tape 7 is a component for fixing the reflector 6 to the circuit board 5. The double-sided tape 7 is in a strip shape extending in the X direction as shown in Fig. 4, and is located between the surface of the first portion 61 facing the circuit board 5 and the circuit board 5 as shown in Fig. 3.

[0020] In this embodiment, the double-sided tape 7 is provided on each of the multiple first portions 61 of the reflector 6, but is not provided on the multiple second portions 62. If the double-sided tape 7 were applied to both the first portions 61 and the second portions 62, double-sided tape 7 extending in both the X and Y directions would be used, which would make it difficult to fix the reflector 6 to the circuit board 5. On the other hand, in this embodiment, the reflector 6 can be fixed to the circuit board 5 by the multiple double-sided tapes 7 extending in the X direction, so that the reflector 6 can be easily fixed to the circuit board 5.

[0021] 5, a recess 62a recessed in a direction away from the circuit board 5 (+Z direction) is formed on the surface of the second portion 62 facing the circuit board 5. The recess 62a is also shown in the rear perspective view of the reflector 6 and the light source 5a shown in FIG.

[0022] Here, FIG. 7 shows a reflector 6r according to a comparative example in which the second portion 62r shown in FIG. 5 does not have a recess 62a. When the reflector 6r is fixed to the circuit board 5 using a plurality of double-sided tapes 7 extending in the X direction, a gap corresponding to the thickness of the double-sided tape 7 is generated between the second portion 62r located between the light sources 5a adjacent in the X direction and the circuit board 5. Then, as shown by the dashed arrow in FIG. 7, there is a risk of light leakage from one dimming zone to the other dimming zone of the light sources 5a adjacent in the X direction. If light leakage occurs in this way, there is a risk of it being difficult to illuminate the desired dimming zone with the desired brightness.

[0023] As shown in FIG. 5, even in this embodiment, a gap corresponding to the thickness of the double-sided tape 7 is generated between the second portion 62 and the circuit board 5, so that there is a risk of light leakage from one dimming zone to the other dimming zone of the light sources 5a adjacent to each other in the X direction. However, since the recess 62a is provided in the second portion 62, even if light from a certain light source 5a enters between the second portion 62 and the circuit board 5, the light is repeatedly reflected between the recess 62a and the circuit board 5 and weakened. Therefore, even if light leakage occurs from one dimming zone to the other dimming zone of the light sources 5a adjacent to each other in the X direction, the amount of light leakage is reduced more favorably than in the comparative example of FIG. 7.

[0024] 5, the recesses 62a do not have to be provided in the second portions 62 that form the edges of the reflector 6. It is sufficient that the recesses 62a are provided in the second portions 62 that are located between the light sources 5a adjacent to each other in the X direction.

[0025] For example, the recess 62a is formed in a V-shape in cross section as shown in Fig. 5, but is not limited to this shape. The recess 62a may have another shape, such as a concave curved shape or a W-shape, as long as it can reduce light leakage as described above.

[0026] In order to further reduce light leakage, the recess 62a may be subjected to at least one of light absorption treatment and surface roughening treatment. The light absorption treatment here refers to coloring the recess 62a with paint of a color such as black or dark blue that has a higher light absorption than the color of the resin that constitutes the reflector 6. The surface roughening treatment refers to a treatment that forms fine irregularities on the surface that constitutes the recess 62a by a known processing method such as embossing, sandblasting, or hairline processing.

[0027] The present invention is not limited to the above-described embodiment and drawings, and can be modified (including the deletion of components) as appropriate without departing from the spirit of the present invention.

[0028] In the above, an example in which the X direction is the first direction and the Y direction is the second direction has been described, but the Y direction may be the first direction and the X direction may be the second direction. That is, the first portion 61 may extend in the Y direction and the second portion 62 may extend in the X direction. In addition, the first direction and the second direction are not limited to being orthogonal to each other, but may intersect each other. That is, the surrounding wall 60 (and the dimming zone) of the reflector 6 is not limited to being square or rectangular, but may be rhombic or parallelogrammatic. In addition, the display device 100 and the lighting device 2 are not limited to being mounted on a vehicle, and may be used for various purposes.

[0029] In the above description, descriptions of well-known technical matters have been omitted as appropriate in order to facilitate understanding of the present disclosure.

[0030] Various embodiments and modifications of the present invention are possible without departing from the broad spirit and scope of the present invention. The above-described embodiments are for the purpose of explaining the present invention and do not limit the scope of the present invention. That is, the scope of the present invention is indicated by the claims, not the embodiments. Various modifications made within the scope of the claims and the scope of the invention equivalent thereto are considered to be within the scope of the present invention. [Explanation of symbols]

[0031] 100...Display device 1. Liquid crystal panel 2. Lighting equipment 3...Optical sheet 4. Housing 5...Circuit board, 5a...Light source 6...reflector, 60...enclosure wall, 61...first part, 62...second part 7…Double-sided tape

Claims

1. A circuit board on which a plurality of light sources are mounted; a lattice-shaped reflector surrounding each of the plurality of light sources; a double-sided tape for fixing the reflector to the circuit board; and The reflector is a first portion extending in a first direction and arranged at intervals in a second direction intersecting the first direction; a plurality of second portions disposed between adjacent first portions and extending in the second direction and spaced apart in the first direction; the double-sided tape has a strip shape extending in the first direction and is positioned between a surface of the first portion facing the circuit board and the circuit board; A recess is formed on a surface of the second portion facing the circuit board, the recess being recessed in a direction away from the circuit board. Lighting equipment.

2. The recess is subjected to at least one of a light absorbing treatment and a surface roughening treatment.

10. The lighting device of claim 1.

3. The lighting device according to claim 1 or 2, and a liquid crystal panel as the target. Display device.

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