JP2009265254A - Edge light type partially driving back light, and edge light type back light partial driving method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an edge type back light unit which is suitably made thin and partially drives a liquid crystal display screen two-dimentionally. <P>SOLUTION: A plurality of sub-edge type back light parts configured to divide the liquid crystal display screen into a plurality of blocks and have light sources and light transmission plates by the blocks are arranged in a stack, and the sub-edge type back light parts irradiate the respective blocks with light independently. When a sub-edge type back light part is arranged over other sub-edge type back light part, a dot pattern is not arranged at a light transmission plate in an area overlapping the other sub-edge type back light part to obtain a mirror surface state, so that light is not emitted repeatedly from an intermediate sub edge type back light part. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a backlight device used in a liquid crystal display device and an edge light type backlight partial driving method.

  In recent years, televisions are moving from those using cathode ray tubes to those using liquid crystals. Furthermore, there is a tendency to shift from a normal thin TV to a wall-mounted LCD TV, and the thinning is accelerated.

  In order to reduce the thickness, the LED light source, which is smaller than the cold-cathode tube, is adopted as the light source of the backlight device, and the adoption of an edge light type backlight that is advantageous for a thin structure is also being promoted. .

  It is known that a backlight capable of partial drive display can realize high contrast and wide color reproducibility.

Although there is an example that realizes partial drive with a direct type backlight, in the case of a direct type backlight, in order to improve luminance unevenness, a certain distance is required between the light source and the diffusion plate, and there is a limit to thinning There is. This will be described with reference to the drawings.
FIG. 4 is an explanatory diagram showing an outline of partial driving by a direct type backlight.
In FIG. 4, 401 is a liquid crystal screen block to be partially driven, 403 is a light source, and 404 is a diffusion plate. Reference numeral 402 denotes a distance from the light source to the diffusion plate 404.
In the case of a direct type backlight, due to the influence of unevenness of light from the light source 403, a distance 402 from the light source to the diffusion plate 404 is required to some extent, and it is difficult to make the structure thin.

On the other hand, if an edge light type backlight is used, a reduction in thickness can be realized, but there are problems in using an edge light type backlight in a stacked manner, and two-dimensional partial driving is difficult. Specifically, in the case of an edge light type backlight, there is a liquid crystal panel that is partially driven in a one-dimensional manner as shown in FIG. 3 in order to place a light source on the side surface of the liquid crystal panel. However, there was no edge light type backlight capable of two-dimensional partial drive display. FIG. 3 is a schematic view of an edge light type backlight capable of one-dimensional partial drive display.
In FIG. 3, reference numeral 301 denotes a light guide plate, and 302 denotes a position where a light source is installed.

  The inventor can devise the light guide plate to make the light source and the light guide plate have a laminated structure, and divide and arrange in blocks so that two-dimensional partial drive is possible with the edge-light type backlight with the light source arrangement on the side only Focused on that.

JP 2007-293339 A

  Therefore, the present invention uses an edge light type backlight that is advantageous for thinning, divides the liquid crystal panel into a plurality of blocks, and irradiates light independently for each block to perform two-dimensional partial driving. An object of the present invention is to provide an edge type backlight unit that can be used.

According to the first aspect of the present invention, the display screen of the liquid crystal panel is divided into a plurality of blocks, and a sub-edge type backlight unit having a light source and a light guide plate independent for each block is disposed on the back side of the liquid crystal panel. An edge-type partial drive backlight unit in which the sub-edge type backlight unit irradiates light independently for each block,
A plurality of the sub-edge type backlight portions are laminated on the back side of the liquid crystal panel,
Among the sub-edge type backlight units, the sub-edge type backlight unit in which the other sub-edge type backlight unit is installed between the sub-edge type backlight unit and the liquid crystal panel. Regarding the light guide plate (hereinafter also referred to as “intermediate sub-edge type backlight portion”), the region where the other sub-edge type backlight portion is present between the liquid crystal panel (hereinafter referred to as “backlight overlapping region”). In other words, it is configured not to irradiate light from the intermediate sub-edge type backlight unit to the backlight overlapping area by setting a mirror surface state without installing a dot pattern on the light guide plate. It is characterized by.

  According to a second aspect of the present invention, there is provided a liquid crystal display device including the edge-type partial drive backlight unit according to the first aspect.

The invention according to claim 3 is a method of dividing the display screen of the liquid crystal panel into a plurality of blocks using an edge type backlight unit, and partially driving each block,
In accordance with the divided blocks, a step of laminating a plurality of sub-edge type backlight portions on the back side of the liquid crystal panel;
For the light guide plate of the intermediate sub-edge type backlight unit, without installing a dot pattern on the light guide plate for the backlight overlap region, installing a dot pattern for the region outside the backlight overlap region; and It is characterized by having.

The invention according to claim 4 relates to an edge type backlight unit,
The edge-type backlight unit partial driving method according to claim 3 is used.

  According to the edge-type partial drive backlight unit according to the present invention, the liquid crystal panel can be divided into a plurality of blocks two-dimensionally, and each block can be partially driven by the edge-type backlight unit. A high contrast and a wide color reproducibility can be realized on the liquid crystal screen while keeping the display device thin.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

FIG. 1 is an explanatory cross-sectional view for explaining the structure of the edge-type partial drive backlight unit according to the first embodiment.
The edge type partial drive backlight unit according to the present invention shown in FIG. 1 is provided between the liquid crystal panel and the sub edge type backlight unit 100 in which no other sub edge type backlight unit exists between the liquid crystal panel. The sub-edge type backlight unit 110 has an intermediate sub-edge type backlight unit 110.
In FIG. 1, 101 is a light source, 102 is a light guide plate, 100 is a sub-edge type backlight unit having the light source 101 and the light guide plate 102, and 103 is a dot pattern. Reference numeral 109 denotes light emitted from the light source 101.

  Reference numeral 111 denotes a light source, 112 denotes a light guide plate, and 110 denotes an intermediate sub-edge type backlight unit having the light source 111 and the light guide plate 112. Reference numeral 119 denotes light emitted from the light source 111. Reference numeral 114 denotes a backlight overlapping area in which the other sub-edge type backlight unit 100 is installed between the intermediate sub-edge type backlight unit 110 and the liquid crystal panel. Reference numeral 115 denotes a region of the light guide plate 112 other than the backlight overlap region.

  As for the light guide plate of the sub-edge type backlight unit 100, a dot pattern is formed on all surfaces in the same manner as a general light guide plate. As a result, the emitted light from the light source 101 is emitted from the entire surface of the light guide plate 102 as represented by the emitted light 109.

Next, the intermediate sub-edge type backlight unit 110 will be described.
In the light guide plate 112 of the intermediate sub-edge type backlight unit 110, the dot pattern 113 is not formed in the backlight overlap region 114, and the mirror surface state is maintained. As a result, the emitted light from the light source 111 travels while being totally reflected in the light guide plate 112 in the backlight overlapping region 114, as represented by the emitted light 119, and the backlight in which the dot pattern 113 is formed. In the region 115 other than the overlapping region 114, irregular reflection is caused by the dot pattern 113, so that the region 115 other than the backlight overlapping region 114 has a backlight effect.

  As described above, by not creating a dot pattern for the backlight overlapping region 114 of the light guide plate 112 of the intermediate sub-edge type backlight unit 110, the sub-edge type backlight unit 100 is partially driven. On the other hand, it is possible to prevent redundant light irradiation.

  As a result, the two-dimensional partial drive of the liquid crystal panel, which has been difficult with the conventional edge type backlight unit, becomes possible.

FIG. 2 is a diagram of FIG. 1 as viewed from above, and is an explanatory diagram for explaining a region of a liquid crystal panel in which two-dimensional partial driving is possible by the edge-type partial driving backlight unit according to the present invention. is there. Although the light source is not shown, it is installed on the left and right edge sides (205, 206) of the liquid crystal panel.
Reference numerals 201 and 203 denote areas where the edges of the liquid crystal panel are in contact with the edges where the light sources are installed, and 202 and 204 are areas where the edges where the light sources are installed are not in contact.

  In order to partially drive an area in contact with the edge where the light source is installed, such as the area 201 and the area 203, the sub-edge type backlight unit 100 of FIG. In order to partially drive the regions 202 and 204 that are not in contact with each other, the intermediate sub-edge type backlight unit 110 shown in FIG. 1 is installed, so that the liquid crystal panel can be partially driven two-dimensionally.

  In FIG. 1, the sub-edge type backlight unit is stacked only in two stages. However, if necessary, the liquid crystal panel can be partially driven in a more complex two-dimensional manner by stacking in two or more stages. Can do.

4 is an explanatory cross-sectional view for explaining the structure of the edge-type partial drive backlight unit according to Embodiment 1. FIG. It is explanatory drawing of the two-dimensional partial drive of a liquid crystal panel by the edge type partial drive backlight unit which concerns on this invention. It is a schematic diagram of an edge light type backlight capable of one-dimensional partial drive display. It is explanatory drawing which shows the outline of the partial drive by a direct type | mold backlight.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Sub edge type backlight part 101 Light source 102 Light guide plate 103 Dot pattern 109 Light emitted from light source 101 110 Intermediate sub edge type backlight part 111 Light source 112 Light guide plate 113 Dot pattern 114 Backlight overlap area 115 Backlight overlap area Area other than

Claims (4)

The display screen of the liquid crystal panel is divided into a plurality of blocks, and a sub-edge type backlight unit having a light source and a light guide plate independent for each block is arranged on the back side of the liquid crystal panel, Sub-edge type backlight unit is an edge type partial drive backlight unit that irradiates light independently,
A plurality of the sub-edge type backlight portions are laminated on the back side of the liquid crystal panel,
Among the sub-edge type backlight units, the sub-edge type backlight unit in which the other sub-edge type backlight unit is installed between the sub-edge type backlight unit and the liquid crystal panel. Regarding the light guide plate (hereinafter also referred to as “intermediate sub-edge type backlight portion”), the region where the other sub-edge type backlight portion is present between the liquid crystal panel (hereinafter referred to as “backlight overlapping region”). In other words, it is configured not to irradiate light from the intermediate sub-edge type backlight unit to the backlight overlapping area by setting a mirror surface state without installing a dot pattern on the light guide plate. An edge-type partial drive backlight unit.   A liquid crystal display device comprising the edge-type partial drive backlight unit according to claim 1. Using an edge-type backlight unit, the display screen of the liquid crystal panel is divided into a plurality of blocks, and each block is partially driven,
In accordance with the divided blocks, a step of laminating a plurality of sub-edge type backlight portions on the back side of the liquid crystal panel;
For the light guide plate of the intermediate sub-edge type backlight unit, without installing a dot pattern on the light guide plate for the backlight overlap region, installing a dot pattern for the region outside the backlight overlap region; and An edge-type backlight unit partial driving method comprising: An edge type backlight unit,
An edge-type partial drive backlight unit manufactured using the edge-type backlight unit partial drive method according to claim 3.

Images