JP7564308B2 - Planar lighting device - Google Patents

Description

The present invention relates to a surface lighting device.

Planar lighting devices used as backlights for liquid crystal display devices, etc., are known. In this type of planar lighting device, cutouts may be provided to allow space for other components to be added for functions other than lighting (see, for example, Patent Documents 1 and 2). For example, in the backlight of a liquid crystal display device mounted on an automobile, a cutout may be provided on the outer edge side of the frame to accommodate a camera for monitoring the driver's line of sight, etc., as another component.

In this way, when a cutout is provided on the outer edge of the frame (sometimes called an irregular shape as opposed to a normal shape without a cutout), it is necessary to ensure space in which other components can be stably placed, as well as take measures to prevent dust and other foreign matter from entering through the cutout, and to take measures to block light so that the illumination light does not inadvertently leak out, causing discomfort to the user, reducing the efficiency of the illumination, or affecting other components. Generally, it is difficult to form the part that surrounds the other components integrally with the frame by drawing or the like, so a separate member that surrounds the other components from the outer wall of the frame to the inside is often prepared, and the separate member is fixed to the frame by crimping or the like.

JP 2020-24800 A JP 2018-77954 A

However, the above measures require the use of separate components with complex shapes to manufacture the frame, making it difficult to produce frame parts, and the cost of frame parts may increase significantly compared to cases where the parts have a normal shape without missing parts. Also, crimps are often used to fasten metal parts to metal frames, but when a separate component is fastened to the frame by crimping, contamination is likely to occur due to foreign matter remaining after crimping, and further increases in costs are expected as measures to address this issue.

Furthermore, the presence of the missing part affects not only the shape of the frame, but also the shape of the outer edge side of the resin injection molded parts such as spacers and reflectors placed inside the surface lighting device. For example, the outer edge side of the spacers and reflectors requires a recess to avoid the separate material attached to the missing part of the frame, and the recess causes deformation due to molding shrinkage, which can cause problems such as demolding and reduced dimensional accuracy.

The present invention has been made in consideration of the above, and aims to provide a surface lighting device that is easy to manufacture even when the missing portion is provided on the outer peripheral end side of the frame.

In order to solve the above-mentioned problems and achieve the object, a surface illumination device according to one aspect of the present invention includes a cylindrical light-shielding component in which other components are arranged, and a frame in which the light-shielding component is arranged and a cutout portion consisting of a hole is provided on an outer peripheral end side . The end face of the light-shielding component is attached and fixed to the periphery of the cutout portion of the frame via double-sided tape.

The planar lighting device according to one aspect of the present invention is easy to manufacture even when the missing portion is provided on the outer peripheral end side of the frame.

FIG. 1 is a perspective view of the appearance of a surface illumination device according to an embodiment. FIG. 2 is a perspective view showing the appearance of the surface illumination device of FIG. 1 as viewed from the rear side. FIG. 3 is an exploded perspective view of the main part of the surface illumination device. FIG. 4 is a diagram showing a state in which the fixing member and the light blocking part are attached to the bottom frame. FIG. 5 is a diagram showing a state in which the fixing member and the light blocking part are attached to the bottom frame. FIG. 6 is a perspective view showing an example of a reflector. FIG. 7 is an external perspective view showing an example of a spacer. FIG. 8 is a diagram showing a state in which a separate member is attached to a bottom frame in a comparative example. FIG. 9 is a diagram showing a state in which a separate member is attached to the bottom frame. FIG. 10 is an external perspective view showing an example of a reflector in a comparative example. FIG. 11 is an external perspective view showing an example of a spacer in a comparative example. FIG. 12 is a diagram showing an example in which the vicinity of a defective portion of a surface illumination device becomes dark.

The surface lighting device according to the embodiment will be described below with reference to the drawings. Note that the present invention is not limited to this embodiment. Furthermore, the dimensional relationships between elements in the drawings and the ratios between elements may differ from reality. The drawings may also include parts with different dimensional relationships and ratios. Furthermore, the contents described in one embodiment or modified example are, in principle, applicable to other embodiments or modified examples in the same way.

Fig. 1 is an external perspective view of a planar lighting device 1 according to one embodiment, and Fig. 2 is an external perspective view of the planar lighting device 1 of Fig. 1 as seen from the back side. In the figure, for convenience, the longitudinal direction of the planar lighting device 1 is the X-axis direction, the short side direction is the Y-axis direction, and the thickness direction is the Z-axis direction. Note that, although a direct-type planar lighting device in which multiple light sources are arranged two-dimensionally along the exit surface will be described as an example, it can also be applied to an edge-light type planar lighting device in which light enters from the side of the light guide plate and exits from one of the main surfaces of the light guide plate.

In Figures 1 and 2, the surface lighting device 1 has a roughly rectangular (or roughly square) plate-like outer shape, and the housing is made up of a bottom frame 2, which is a box-like frame with a floor and contains a substrate and other components described below, and a top frame 16 that covers the opening side of the bottom frame 2. The top frame 16 has an exit surface 1a formed by a roughly rectangular opening, and light is emitted from the inside of the surface lighting device 1 to the outside.

In addition, a light-shielding part 4 is provided on the outer peripheral end side of the surface lighting device 1, in the recess 1b where other parts such as a camera are arranged, and the light-shielding part 4 is covered on the emission surface 1a side by the edge 16a of the top frame 16. The recess 1b is composed of a rectangular hole with a closed outer periphery, and the cylindrical light-shielding part 4 is arranged in the hole. The light-shielding part 4 is formed, for example, from resin. Note that the hole of the recess 1b is not limited to a rectangle, and can be changed to a circle, ellipse, triangle, etc. depending on the parts to be arranged and the design.

The back side of the bottom frame 2 is provided with a boss portion 2f for mounting, and a connector 6b for electrical connection. The bottom frame 2 and the top frame 16 are formed by die casting, sheet metal, or the like. When the surface lighting device 1 is used as a backlight for an in-vehicle navigation device, indicator, or the like, a liquid crystal display device or the like is attached to the side of the emission surface 1a.

Figure 3 is an exploded perspective view of the main parts of the surface lighting device 1, and is a view seen from the light output surface side, similar to Figure 1. In Figure 3, the surface lighting device 1 has a bottom frame 2 to which a fixing member 3, a light blocking part 4, a substrate 6 on which a light source 7 is arranged, a reflector 9, a lens 11, a spacer 13, and optical sheets 15A to 15C are attached, and is covered with a top frame 16.

Figure 4 is a diagram showing the state in which the fixing member 3 and the light-shielding part 4 are attached to the bottom frame 2. In Figure 4, the bottom frame 2 has a substantially rectangular bottom 2a and four side walls 2b surrounding the periphery of the bottom 2a. A fixing member 3 made of a substantially rectangular frame-shaped double-sided tape or the like is attached to surround a hole 2c (corresponding to the missing part 1b) provided on the outer peripheral end side of the bottom 2a, and the end face of the cylindrical light-shielding part 4 is attached and fixed on top of the fixing member 3. The bottom frame 2 is provided with a plurality of holes 2d to which the boss part 2f (Figure 2) is fixed, and a hole 2e through which the connector 6b on the board 6 is exposed. Figure 5 is a diagram showing the state in which the fixing member 3 and the light-shielding part 4 are attached to the bottom frame 2.

Returning to FIG. 3, the substrate 6 is fixed to the inner bottom (2a) of the bottom frame 2 via a fixing member (not shown) such as a sheet-like double-sided tape. A plurality (a large number) of light sources 7 such as LEDs (Light Emitting Diodes) are arranged two-dimensionally on the substrate 6. A recess 6a is formed on the outer peripheral end side (the upper end side in the figure) of the substrate 6 so as to avoid the light-shielding component 4.

Reflectors 9 are fixed between the light sources 7 on the substrate 6 via multiple fixing members (not shown) such as double-sided tape that are shaped like strips and extend vertically in the figure. The reflectors 9 reflect the light emitted from the light sources 7 in the normal direction of the light emission surface, thereby increasing the brightness.

Figure 6 is an external perspective view showing an example of a reflector 9. In Figure 6, a substantially rectangular reflector body 9a is provided with multiple (many) unit reflectors 9b. The unit reflector 9b has a substantially rectangular hole through which the light source 7 is placed, and four inclined reflecting surfaces surrounding the hole and opening toward the light exit surface. In addition, a substantially rectangular hole 9c through which the light blocking part 4 (Figures 3 to 5) is inserted is formed on the outer peripheral end side of the reflector 9, and the outer peripheral end side of the hole 9c has a continuous connecting shape 9d. The reflector 9 is manufactured by injection molding of resin, etc.

Returning to FIG. 3, the lens 11 is fixed to the upper end of the reflector 9 via a fixing member (not shown) made of a plurality of rectangular double-sided tape or the like. The lens 11 is used to adjust the light distribution and brightness of the light emitted from the reflector 9. Two protrusions 11a are provided near the center of the lens 11 to maintain a distance from the optical sheet 15A.

Spacers 13 are fixed near the top, bottom, left and right ends of the lens 11 using multiple rectangular fixing members (not shown) such as double-sided tape.

Figure 7 is an external perspective view showing an example of the spacer 13. In Figure 7, the spacer 13 is composed of a substantially rectangular frame-shaped spacer body 13a, and the portion adjacent to the light-shielding component 4 (Figures 3 to 5) has a continuous connecting shape 13b at the end. The spacer 13 is manufactured by injection molding of resin, etc.

Returning to FIG. 3, optical sheets 15A-15C are fixed to the upper end of spacer 13 in the figure via a fixing member (not shown) made of a plurality of rectangular double-sided tape or the like. The fixing member has a step, and ears 15a-15c of optical sheets 15A-15C are respectively fixed to spacer 13 without overlapping via the fixing member. Optical sheets 15A-15C adjust the light distribution and brightness of the light passing through, and are diffusion sheets (diffusion films), prism sheets (prism films), brightness enhancement sheets (brightness enhancement films), louver sheets (louver films), etc.

A top frame 16 is disposed on the exit surface side of the optical sheet 15C, and the top frame 16 is fixed to the bottom frame 2.

Figure 8 is a diagram showing a state in which a separate member 4' is attached to a bottom frame 2' in a comparative example. In this comparative example, a recess 2a' is provided on the outer peripheral end side of the bottom frame 2' corresponding to the missing portion where other parts such as a camera are placed, and a separate member 4' is fixed to the recess 2a'. The separate member 4' has a portion that becomes a wall surrounding the missing portion and a portion for fixing to the bottom of the bottom frame 2', and is integrally formed from sheet metal or the like.

The hole 4a' of the separate member 4' is subjected to burring (hole flange processing), and the flange portion of the hole 4a' is inserted into the hole 2b' of the bottom frame 2' and then crimped, thereby fixing the separate member 4' to the bottom frame 2'. Figure 9 shows the state in which the separate member 4' is attached to the bottom frame 2'.

However, in the configurations of Figures 8 and 9, a separate member 4' with a complex shape is required to manufacture the bottom frame 2', making it difficult to produce the frame parts, and the cost of the frame parts may increase significantly compared to a normal shape without missing parts. In addition, when the separate member 4' is fixed to the bottom frame 2' by crimping, contamination is likely to occur due to foreign matter remaining after crimping, and further cost increases are expected to be required to deal with this (such as adding tape to the crimped part to prevent foreign matter from falling off).

In contrast, the bottom frame 2 of the embodiment shown in Figures 4 and 5 has a hole 2c that corresponds to the missing part where other parts such as a camera are placed, and the light-shielding part 4 is simply fixed to this hole 2c via the fixing member 3, so the cost of the frame parts does not increase significantly compared to a normal shape without missing parts. In addition, since crimping is not required, contamination problems do not occur and there is no need to increase costs for contamination countermeasures.

Figure 10 is an external perspective view showing an example of a reflector 9' in a comparative example. In Figure 10, a recess 9a' is provided on the outer peripheral end side of the reflector 9' in the comparative example to avoid a separate member 4' attached to the bottom frame 2' (Figures 8 and 9).

Figure 11 is an external perspective view showing an example of a spacer 13' in a comparative example. In Figure 11, a recess 13a' is provided on the outer peripheral end side of the spacer 13' in the comparative example to avoid a separate member 4' attached to the bottom frame 2' (Figures 8 and 9).

In Figures 10 and 11, reflector 9' and spacer 13' are generally manufactured by injection molding using resin, but the recesses 9a' and 13a' cause deformation due to molding shrinkage, which can cause problems such as problems with demolding and reduced dimensional accuracy.

In contrast, in the embodiment of the reflector 9 and spacer 13 shown in Figures 6 and 7, connecting shapes 9d, 13b are provided to surround the light-shielding part 4 that is provided in correspondence with the missing part where other parts such as a camera are placed, and no recesses are formed at the ends of the reflector 9 or spacer 13. Therefore, deformation due to molding shrinkage caused by the recesses does not occur, and problems such as problems with demolding and reduced dimensional accuracy do not occur.

Next, the material of the light-shielding part 4 in Figures 1 to 5 will be described. If other parts such as a camera are placed inside the light-shielding part 4, and the surface surrounding the light-shielding part 4 emits light with high luminance, the other parts will stand out. Therefore, if you do not want the other parts to stand out, it is effective to reduce the luminance around the light-shielding part 4. In this case, it is desirable to use a black low-reflection (high-absorption) material for the light-shielding part 4. Figure 12 is a diagram showing an example in which the vicinity of the defective part of the planar lighting device 1 becomes dark. Conversely, if high luminance is required because the liquid crystal display device displays images up to the periphery of the light-shielding part 4, it is desirable to use a white high-reflection (low-absorption) material for the light-shielding part 4.

In addition, if the other part is a camera, and light blocking is required to prevent light from entering the camera, and the area around the light blocking part 4 needs to be bright, the inside of the light blocking part 4 can be made black and the outside white by two-tone molding or coloring.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the present invention.

As described above, the surface lighting device according to the embodiment includes a frame having a cutout portion on the outer peripheral end side, the cutout portion being a hole with a closed periphery, in which other components are placed, and a cylindrical light-shielding component that is placed in the cutout portion and surrounds the hole. This makes the device easy to manufacture, even when the cutout portion is located on the outer peripheral end side of the frame.

The missing portion and the light-shielding part are also roughly rectangular when viewed from the direction of emission. This makes positioning easier during assembly.

In addition, black, low-reflectivity materials are used for the light-shielding parts when it is desired to darken the area around the defect, and white, high-reflectivity materials are used when it is desired to brighten the area around the defect. This makes it possible to meet a variety of needs, such as making the defect less noticeable or maintaining high brightness up to the vicinity of the defect.

The inner and outer surfaces of the light-shielding component can be the same color or different colors. This allows the light-shielding component to both block light from inside and meet the requirements for brightness on the outside.

The frame also has an injection molded part with a connecting shape that is adjacent to the light-shielding part and is provided on the outer peripheral end side of the frame. This prevents deformation due to molding shrinkage, and eliminates problems such as issues with demolding and reduced dimensional accuracy.

Furthermore, the present invention is not limited to the above-mentioned embodiment. The present invention also includes configurations in which the above-mentioned components are appropriately combined. Furthermore, further effects and modifications can be easily derived by those skilled in the art. Therefore, the broader aspects of the present invention are not limited to the above-mentioned embodiment, and various modifications are possible.

1 Planar lighting device, 1b Missing part, 2 Bottom frame, 2c Hole, 3 Fixing member, 4 Light shielding part, 6 Substrate, 7 Light source, 9 Reflector, 9d Joint shape, 11 Lens, 13 Spacer, 13b Joint shape, 15A to 15C Optical sheets, 16 Top frame

Claims (9)

A cylindrical light-shielding part in which other parts are arranged;
a frame in which the light-shielding component is disposed and a cutout portion formed of a hole is provided on an outer peripheral end side;
Equipped with
The light-shielding component has an end surface that is affixed and fixed to the periphery of the missing portion in the frame via double-sided tape. A frame having a recessed portion on an outer peripheral end side in which other components are arranged;
A cylindrical light-shielding part to be placed in the missing portion;
A plurality of light sources;
a reflector surrounding the plurality of light sources;
Equipped with
The reflector is provided with a hole through which the light blocking part is inserted.
Surface lighting device. The recess and the light-shielding component are rectangular when viewed from the light emission direction.
3. A spread illuminating device according to claim 1 or 2 . The light-shielding part is made of a black material when it is desired to darken the periphery of the defect, and is made of a white material when it is desired to brighten the periphery of the defect.
The spread illuminating device according to any one of claims 1 to 3 . The light-shielding parts are set to have the same color or different colors on the inner and outer surfaces.
The spread illuminating device according to any one of claims 1 to 4 . Another component is disposed inside the light-shielding component.
The spread illuminating device according to any one of claims 1 to 5 . A light source device comprising: a plurality of light sources; and a reflector surrounding the plurality of light sources;
The reflector is provided with a hole through which the light blocking part is inserted.
2. The spread illuminating device according to claim 1 . the reflector has a connecting shape on an outer peripheral end side of a hole through which the light-shielding part is inserted,
The connecting shape is disposed on an outer peripheral end side corresponding to a missing portion of the frame.
8. The spread illuminating device according to claim 7 . The light-shielding component is fixed by attaching an end surface to the periphery of the missing portion in the frame via double-sided tape.
3. The spread illuminating device according to claim 2.

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