JP2008034273A - Reflector for direct backlight - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reflector for a direct backlight of a liquid crystal display device capable of reducing or eliminating luminance irregularity with a relatively simple structure by effectively utilizing reflection light that was ineffective in the past. <P>SOLUTION: This reflector for a direct backlight is arranged behind a plurality of light sources for illuminating a liquid crystal display panel, and reflects light from the light sources toward the liquid crystal display panel. The reflector for a direct backlight of a liquid crystal display device is characterized in that the reflector is slantly arranged above the light source adjacent thereto from an area between the light sources; a folded part at a predetermined angle is formed at its end; light emitted from the light source is reflected on the folded part formed above the light source adjacent thereto; and the reflected light is reflected toward the liquid crystal display panel. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a reflector used in a liquid crystal display device such as a computer monitor or a television. More specifically, the present invention relates to a reflector disposed between a plurality of light sources (for example, LEDs) for illuminating a liquid crystal display panel. The present invention relates to a direct-type backlight reflector that reflects the light toward the liquid crystal display panel.

Conventionally, a reflector for a direct backlight, in which mountain-shaped reflecting surfaces having a substantially triangular cross section are formed in parallel at an equal pitch so as to be arranged between a plurality of light sources (for example, LEDs), and the like As an illumination / display device using a simple reflector, Japanese Patent Application Laid-Open No. 2002-107720 (see Patent Document 1), Japanese Patent Application Laid-Open No. 2003-156610 (see Patent Document 2), Japanese Patent Application Laid-Open No. 2004-109205 (see Patent Document 3). ) Etc. are known.

In such a direct-type backlight reflector, since it is easy to generate luminance unevenness in which the portion close to the light source is bright and dark between the light sources, the shape of the mountain-shaped reflecting surface has been conventionally used to eliminate the luminance unevenness. Various proposals have been made (see, for example, Patent Documents 1 and 2).
JP 2002-107720 A JP 2003-156610 A JP 2004-109205 A

Uneven brightness is more likely to occur as the distance between the reflector and the diffuser becomes shorter, and the direct light from the light source and the light reflected from the reflector are reflected by the diffuser when the incident angle exceeds the incident angle. As a result, it is a wasteful light that does not come out to the front side (the liquid crystal display panel side) from the diffusion plate, and as a practical matter, it is very difficult to eliminate the luminance unevenness with a simple structure.

Therefore, the present invention has been devised in the structure of the reflecting plate to control the light that was wasted by hitting the flat bottom so that the incident angle of the light entering the diffusing plate becomes an acute angle, and the luminance was low. It has been found that brightness unevenness can be reduced or eliminated with a relatively simple structure by controlling the reflected light to strike the part, and the present invention has been completed.
That is, the present invention provides a reflector for a direct-type backlight of a liquid crystal display device that can reduce or eliminate luminance unevenness with a relatively simple structure by effectively using reflected light that has been invalidated conventionally. It is something to try.

In order to achieve the above object, a direct-type backlight reflector for a liquid crystal display device according to claim 1 of the present invention is disposed behind a plurality of light sources to illuminate the liquid crystal display panel, and emits light from the light sources. A reflector for a direct backlight that reflects to the liquid crystal display panel side, and is inclined from above the light source to an upper part of an adjacent light source, and has a folded portion at a predetermined angle at an end thereof. The light emitted from the light source is reflected by the folded portion formed above the adjacent light source, and the reflected light is reflected toward the liquid crystal display panel.

According to a second aspect of the present invention, a direct backlight backlight reflector is disposed behind a plurality of light sources to illuminate the liquid crystal display panel and transmits light from the light sources to the liquid crystal display panel side. A reflector for direct type backlight to be reflected, which is inclined from above the light source to the upper part of the adjacent light source, and is formed with a folded portion at a predetermined angle at the end thereof. However, it is characterized in that it is reflected on the inclined surface from the folded portion formed on the upper part of the adjacent light source, and the reflected light is reflected on the liquid crystal display panel side.

According to a third aspect of the present invention, there is provided the direct-type backlight reflector of the liquid crystal display device, wherein the light emitted from the light source passes through the upper part of the folded portion formed on the upper part of the adjacent light source. It is also characterized in that the light is irradiated.

As described above, the direct-type backlight reflector of the liquid crystal display device according to the present invention is inclined from the light source to the upper part of the adjacent light source in the first invention, and the folded portion at a predetermined angle is provided at the end thereof. The light emitted from the light source is reflected by the folded portion formed above the adjacent light source, and the reflected light is reflected to the liquid crystal display panel side.
Therefore, conventionally, it is possible to control the light that has been wasted by hitting the flat bottom surface portion so that the incident angle of the light entering the diffusion plate becomes an acute angle, and the reflected light hits the portion where the luminance is low. As a result, the luminance unevenness can be reduced or eliminated with a relatively simple structure.

In the direct-type backlight reflector of the liquid crystal display device according to the second aspect of the invention, the reflector is provided to be inclined from above the light source to the upper part of the adjacent light source, and a folded portion of a predetermined angle is formed at the end thereof. The light emitted from the light source is reflected on the inclined surface from the folded portion formed on the adjacent light source, and the reflected light is reflected on the liquid crystal display panel side.
Therefore, in this case as well, the wasted light hitting the flat bottom surface is controlled so that the incident angle of the light entering the diffuser becomes an acute angle, and the reflected light hits the part where the luminance is low. This makes it possible to reduce or eliminate luminance unevenness with a relatively simple structure.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic diagram showing a first embodiment of a reflector for a direct backlight according to the present invention, FIG. 2 is a schematic diagram showing a single reflector of the embodiment, FIG. 3 is a schematic diagram showing a second embodiment, FIG. 4 is a schematic view showing a third embodiment.

1 and 2, the direct-type backlight reflector 11 according to the first embodiment is disposed behind a plurality of light sources to illuminate the liquid crystal display panel, and transmits light from the light sources to the liquid crystal display panel. Reflected to the side.
The direct-type backlight reflector 11 is provided so as to be inclined from above the light sources 12 made of LEDs or the like to the upper portion of the adjacent light source 12, and a folded portion 14 having a predetermined angle is formed at the end thereof. is there. Since the angle of the folded portion 14 is formed to be slightly more acute than the right angle with respect to the bottom surface portion 13, the light emitted from the light source 12 is reflected by the folded portion 14 formed above the adjacent light source 12. The reflected light is reflected to the liquid crystal display panel side.

That is, in the direct-type backlight reflector 11 in the above embodiment, the light 21 irradiated from the light source 12 is reflected into the reflected light 22 reflected on the flat bottom surface portion 13 and the reflected light 23 reflected on the folded portion 14. Divided. The reflected light 22 reflected on the bottom surface portion 13 is further divided into a reflected light 22-1 reflected to the liquid crystal display panel side and a reflected light 22-2 reflected on the folded portion 14.
The reflected light 22-1 reflected toward the liquid crystal display panel is emitted from the light source 12 toward the upper portion on the folded portion 14 side. Further, the reflected light 22-2 and the reflected light 23 reflected by the folded portion 14 are further reflected by the bottom surface portion 13 and irradiated toward the upper portion on the light source 12 side.
Note that the height, inclination angle, and pitch (number) of the folded portions 14 formed on the direct-type backlight reflector 11 are optimally designed according to the required size of the display device and the size of the light source 12.

In FIG. 3, the direct-type backlight reflector 31 according to the second embodiment is also arranged behind a plurality of light sources to illuminate the liquid crystal display panel, and reflects light from the light sources to the liquid crystal display panel side. It is something to be made.
The direct-type backlight reflector 31 is provided to be inclined from above the light sources 32 made of LEDs or the like to the upper part of the adjacent light source 32, and a folded portion 34 having a predetermined angle is formed at the end thereof. is there. Since the angle of the folded portion 34 is formed to be somewhat obtuse than the right angle with respect to the bottom surface portion 33, the light emitted from the light source 32 is reflected by the folded portion 34 formed on the upper portion of the adjacent light source 32. The reflected light is reflected to the liquid crystal display panel side.

That is, in the direct-type backlight reflector 31 in the above embodiment, the light 41 emitted from the light source 32 is reflected into the reflected light 42 reflected on the flat bottom surface portion 33 and the reflected light 43 reflected on the folded portion 34. Divided. The reflected light 42 reflected on the bottom surface portion 33 is further divided into a reflected light 42-1 reflected toward the liquid crystal display panel and a reflected light 42-2 reflected on the folded portion 34.
The reflected light 42-1 reflected toward the liquid crystal display panel is emitted from the light source 32 toward the upper portion on the folded portion 34 side. Further, the reflected light 42-2 and the reflected light 43 reflected by the folded portion 34 are irradiated directly toward the upper part on the light source 32 side.
Note that the height, inclination angle, and pitch (number) of the folded portions 34 formed on the direct-type backlight reflector 31 are also optimally designed according to the required size of the display device and the size of the light source 32.

4, the direct-type backlight reflector 51 according to the third embodiment is also arranged behind a plurality of light sources to illuminate the liquid crystal display panel, and reflects light from the light sources toward the liquid crystal display panel side. It is something to be made.
The direct-type backlight reflector 51 is provided so as to be inclined between the light sources 52 made of LEDs or the like and on the upper part of the adjacent light source 52, and a folded portion 54 having a predetermined angle is formed at the end thereof. is there. Since the angle of the folded portion 54 is formed at an obtuse angle larger than the substantially right angle with respect to the bottom surface portion 53, the light irradiated from the light source 52 is reflected at the folded portion 54 formed above the adjacent light source 52. The reflected light is reflected on the liquid crystal display panel side.

That is, in the direct-type backlight reflector 51 in the above embodiment, the light 61 emitted from the light source 52 is reflected into the reflected light 62 reflected on the flat bottom surface portion 53 and the reflected light 63 reflected on the folded portion 54. Divided. The reflected light 62 reflected on the bottom surface portion 53 is further divided into reflected light 62-1 reflected to the liquid crystal display panel side and reflected light 62-2 reflected on the folded portion 54.
The reflected light 62-1 reflected toward the liquid crystal display panel is emitted from the light source 52 toward the upper portion of the folded portion 54. The reflected light 62-2 and the reflected light 63 reflected by the folded portion 54 are also irradiated toward the upper portion of the folded portion 54.
Note that the height, inclination angle, and pitch (number) of the folded portions 54 formed on the direct-type backlight reflector 51 are also optimally designed according to the required size of the display device and the size of the light source 52.

The direct-type backlight reflectors 11, 31, 51 of the first, second, and third embodiments can be used in appropriate combinations so that the above-described characteristics of reflected light can be utilized. is there.

The reflector for a direct backlight of the liquid crystal display device according to the present invention can be applied to various lighting devices as well as the liquid crystal display device described above.

It is the schematic which shows 1st Example of the reflecting plate for direct type | mold backlights of this invention. It is the schematic which shows the reflecting plate single-piece | unit of the said Example. It is the schematic which shows 2nd Example. It is the schematic which shows 3rd Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Direct type | mold backlight reflecting plate 12 Light source 13 Bottom surface part 14 Return part 21 Light 22 Reflected light 22-1 and 22-2 Reflected light 23 Reflected light 31 Direct type backlight reflector 32 Light source 33 Bottom part 34 Return part 41 Light 42 Reflected light 42-1 and 42-2 Reflected light 43 Reflected light 51 Reflector plate for direct type backlight 52 Light source 53 Bottom surface portion 54 Folded portion 61 Light 62 Reflected light 62-1 and 62-2 Reflected light 63 Reflected light

Claims (3)

A direct-type backlight reflector disposed behind a plurality of light sources for illuminating a liquid crystal display panel and reflecting light from the light sources toward the liquid crystal display panel, the light sources adjacent to each other between the light sources The light is emitted from the light source and reflected from the folded part formed on the upper part of the adjacent light source, and the reflected light is formed. Reflecting toward the liquid crystal display panel, a reflector for a direct backlight of a liquid crystal display device. A direct-type backlight reflector disposed behind a plurality of light sources for illuminating a liquid crystal display panel and reflecting light from the light sources toward the liquid crystal display panel, the light sources adjacent to each other between the light sources The light is emitted from the light source and reflected from the folded surface formed on the upper part of the adjacent light source on the inclined surface. A reflection plate for a direct backlight of a liquid crystal display device, wherein the reflected light is reflected toward the liquid crystal display panel. 3. The liquid crystal according to claim 1, wherein light emitted from a light source passes through an upper portion of a folded portion formed on an upper portion of the adjacent light source and is emitted to the liquid crystal display panel side. 4. Reflector for direct backlight of display device.

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