JP3395940B2 - Liquid crystal display - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly to a technique effective when applied to a backlight used as a light source of a liquid crystal display device.

[0002]

2. Description of the Related Art Conventionally, a simple matrix type liquid crystal display module (LCM) is known as one of liquid crystal display devices.

FIG. 9 is an exploded perspective view of a conventional simple matrix type liquid crystal display module (LCM).

In FIG. 9, 701 is a frame-shaped upper frame made of a metal plate, 702 is a silicon spacer, and 703.
Is a liquid crystal display panel (LCD), 704 is a drive circuit board,
705 is a mold, 706 is a prism sheet, 707 is a light guide plate assembly, 708 is a cold shade 1 fluorescent lamp (cold cathode tube), 7
09 is a rubber bush, 710 is a cable connector, 71
Reference numeral 1 is a silver reflection sheet, and 712 is a lower frame made of a metal plate.

As shown in FIG. 9, in a conventional liquid crystal display module (LCM), a cold cathode fluorescent lamp 708 and light from the cold cathode fluorescent lamp 708 are supplied to a liquid crystal display panel (LC).
D) Light guide plate assembly 707 that irradiates 703, a prism sheet 706 that collects light from the light guide plate assembly 707, and a lower frame 71 in which white paint is applied to a metal plate.
2 is a frame-shaped mold 7 in the order shown in FIG.
It is fitted in the window of 05.

Here, the light guide plate assembly 707 includes a light guide plate made of an acrylic plate, and a reflection sheet and a diffusion sheet formed on both sides of the light guide plate.

Around the cold-cathode fluorescent lamp 708, a cold-cathode fluorescent lamp 708 is enclosed in order to collect light emitted in a different direction from that of the light guide plate assembly 707 to the light guide plate assembly without waste. The silver reflection sheet 711 is arranged so as to be open.

A semiconductor integrated circuit (IC) for driving a liquid crystal display panel (LCD) 703 on a drive circuit board 704.
Is mounted, and a liquid crystal display panel (LCD) 703 around which the drive circuit board 704 is mounted is a mold 705.
Mounted on the window part of the upper frame 7
01 is stacked and the lower frame is sandwiched by the claws provided on the upper frame 701 to assemble the liquid crystal display module (LCM).

Here, the mold 705, the prism sheet 706, the cold cathode fluorescent lamp 708, the silver reflection sheet 711, the light guide plate assembly 707 and the lower frame 712 serve as a backlight for irradiating the liquid crystal display panel 703 with light. Constitute.

This backlight has a light guide plate assembly 707.
The cold-cathode fluorescent lamps 708 are arranged close to each other along the side surface of the light-guiding plate, so that as much light as possible from the cold-cathode fluorescent lamps 708 is guided to the light guide plate assembly 707, and at the same time, space saving is achieved.

FIG. 10 is a plan view showing a state in which a cold cathode fluorescent lamp 708 and a light guide plate 713 are attached to a mold 705 in the conventional simple matrix type liquid crystal display module (LCM) shown in FIG.

As shown in FIG. 10, a protrusion 710 is provided on the mold 705, and a cut 711 is formed in the light guide plate 713.
By providing the cold cathode fluorescent lamp 708 and the light guide plate 71.
The light guide plate 7 is made to have a constant distance from the light guide plate 3 when a shock (F shown in FIG. 10) is applied in the direction of the arrow shown in FIG.
13 is prevented from moving to the cold cathode fluorescent lamp 708 side.

In FIG. 10, 712 is a cable, and the mold 705 is made of a plastic material in which polycarbonate and ABS resin are mixed.

[0014]

In recent years, in the liquid crystal display device, the display screen of the liquid crystal display panel has become larger and larger, and accordingly, the frame of the liquid crystal display panel has become narrower, that is, the periphery of the liquid crystal display panel. The part (frame) is smaller.

Therefore, also in the conventional simple matrix type liquid crystal display module (LCM) shown in FIG. 9, the effective display area of the liquid crystal display panel (LCD) 703 becomes large, and accordingly, it occupies the entire area of the light guide plate 713. The effective display area of the liquid crystal display panel (LCD) 703 is large, and the liquid crystal display panel (LC
D) As the frame of 703 becomes narrower, the distance between the cold cathode fluorescent lamp 708 and the light guide plate 713 becomes narrower.

Therefore, when the cold cathode fluorescent lamp 708 and the light guide plate 713 are attached to the mold 705 by the method shown in FIG. 10, the region where the cut 711 is formed in the light guide plate 713 becomes small, so that the mold 705 is formed. The width of the formed protrusion 710 (d shown in FIG. 10) becomes smaller,
When an impact (F shown in FIG. 10) is applied in the direction of the arrow shown in FIG. 10, the protrusion 710 is damaged and the cold cathode fluorescent lamp 708 is broken.

Further, since the notch 711 is formed in the light guide plate 713, the portion of the liquid crystal display panel (LCD) 703 corresponding to the notch 711 is not irradiated with light from the cold cathode fluorescent lamp 708 by the light guide plate 713. Liquid crystal display panel (LCD) occupying the entire area of the light guide plate 713.
When the ratio of the effective display area of 703 increases, the cutout portion 711 of the liquid crystal display panel (LCD) 703.
There is also a problem that the brightness of the portion corresponding to is lowered.

The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a liquid crystal display device with a narrow frame even if the liquid crystal display panel is narrowed.
It is an object of the present invention to provide a technique capable of improving a mounting strength between a light guide plate assembly and a light source and further improving a luminance deviation to obtain a uniform luminance distribution.

The above objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[0020]

Among the inventions disclosed in the present application, a brief description will be given to the outline of typical ones.
It is as follows.

[0021] That is, a liquid crystal display device comprising a liquid crystal display panel and a backlight for illuminating the liquid crystal display panel, wherein the backlight includes a light guide plate, a first side surface of the light guide plate It has a light source arranged in the vicinity, and a frame-shaped body that houses the light source and the light guide plate, the light guide plate has a surface and a second side surface intersecting with the first side surface ,
The second and a protrusion outward from the side, the surface of the light guide plate, the dot pattern for irradiating the light emitted from the light source to the liquid crystal display panel side is formed, prior to SL projection Is a protrusion that is continuous with the surface of the light guide plate.
Has a front surface, said projections surface, the dot pattern
And the frame-shaped body has a window portion and a concave portion provided around the window portion and into which the protrusion is inserted.

The present invention is also a liquid crystal display device comprising a liquid crystal display panel and a backlight for illuminating the liquid crystal display panel, wherein the backlight is a light guide plate and a first light guide plate. 1 has a light source arranged in the vicinity of the side surface, and a frame-shaped body that houses the light source and the light guide plate,
The light guide plate has a second side surface that intersects with the first side surface.
And a protrusion that extends outward from the second side surface,
Projections on the surface of the light guide plate, the dot pattern for the illumination light from a light source for irradiating the liquid crystal display panel side is formed, the pre-Symbol protrusion, which is continuous with the surface of the light guide plate of
Has a section table surface, wherein the protrusion surface, the dot pattern
And the frame-shaped body has a window portion and a recessed portion formed around the window portion and into which the protrusion is inserted. The shear strength of the light guide plate is equal to that of the frame-shaped body. It is characterized by being stronger than the shear strength.

In a preferred embodiment of the present invention, the backlight has a prism sheet, and the prism sheet has a side extending in the same direction as the second side surface of the light guide plate.
And the side has a protrusion protruding outward from the side .

According to the above-mentioned means, in the liquid crystal display device, at least one projection is provided on the light guide plate, and the projection is fitted in the recess provided in the frame-like body, so that the machine against impact It is possible to improve the dynamic strength.

Further, projections to be formed on the outside of the light guide plate, it is possible to sufficiently cope with a narrow frame liquid crystal display panel.

Furthermore , since the size or density of the dot pattern near the protrusions of the light guide plate is adjusted, the distribution of the light emitted from the light source emitted from the light guide plate to the liquid crystal display panel is determined by the liquid crystal panel. can be made uniform over the entire surface and that Do.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention in which the present invention is applied to a simple matrix type liquid crystal display module (LCM) will be described below with reference to the drawings.

In all the drawings for explaining the embodiments of the invention, components having the same function are designated by the same reference numeral, and the repeated description thereof will be omitted.

FIG. 1 is a perspective view showing a schematic structure of a simple matrix type liquid crystal display module (LCM) which is an embodiment of the present invention.

In FIG. 1, 101 is a frame-shaped upper frame made of metal, 102 is a silicon spacer, 103 is a liquid crystal display panel (LCD), 104 is a drive circuit board, 1
Reference numeral 05 denotes a mold, 106 a prism sheet, 107 a light guide plate assembly, 108 a cold cathode fluorescent lamp (cold cathode tube), 10
9 is a rubber bush, 110 is a cable connector, 111
Is a silver reflection sheet, 112 is a lower frame made of a metal plate, 113 is a bar spacer, 114 is a flat cable,
Reference numeral 115 is a tape carrier package, and 205 is a cable.

The drive circuit board 104 on which the tape carrier package 115 is mounted is divided into three parts, and each drive circuit board is electrically connected by the flat cable 114.

The tape carrier package 115 has an IC for driving the liquid crystal display panel (LCD) 103.
The chip is mounted by tape automated bonding (TAB).

Also in the liquid crystal display module (LCM) of the embodiment of the present invention, the cold cathode fluorescent lamp 108 and the light from the cold cathode fluorescent lamp 108 are used in the liquid crystal display panel (LCD) 1.
03, the light guide plate assembly 107 and the light guide plate assembly 10
A prism sheet 106 that collects the light from 7 and
The lower frame 112 in which the white paint is applied to the metal plate is
It is fitted into the window portion of the mold 105 formed in a frame shape in the order shown in FIG.

Around the cold cathode fluorescent lamp 108, in order to focus light emitted in a direction different from that of the light guide plate assembly 107 on the light guide plate assembly without waste, silver reflection is performed so as to wrap the cold cathode fluorescent lamp 108. The seat 111 is arranged.

Further, the liquid crystal display panel (LCD) 103 on which the drive circuit board 104 is mounted is provided around the mold 10.
5 is placed on the window portion, and the upper frame 101 is further laid on this, and the claws provided on the upper frame 101
A liquid crystal display module (LCM) is assembled by sandwiching the lower frame.

FIG. 2 is an exploded perspective view showing a schematic structure of the light guide plate assembly 107 shown in FIG.

As shown in FIG. 2, the light guide plate assembly 107.
Is composed of a light guide plate 201, and a diffusion sheet 202 and a reflection sheet 203 provided on both sides of the light guide plate 201.

FIG. 3 shows a light guide plate 201 of a simple matrix type liquid crystal display module (LCM) according to an embodiment of the present invention.
FIG.

As shown in FIG. 3, in the embodiment of the present invention, the convex portions 204 are formed at the center of gravity of the light guide plate 201 on both sides of the light guide plate 201 (direction perpendicular to the surface facing the cold cathode fluorescent lamp 108). Is provided.

In this case, since the convex portion 204 formed on the light guide plate 201 is formed at the center of gravity of the light guide plate 201, when the light guide plate 201 has a wedge shape as shown in FIG. The position of the convex portion 204 is the cold cathode fluorescent lamp 10.
It is formed at a position close to 8.

As for the size of the convex portion 204, for example, the dimensions of the light guide plate 201 are as follows: length (L) 180 mm, width (B) 230 mm, height (a) 3.5 mm, height (b).
In the case of 1.3 mm, the length (S) may be 10 mm and the width (H) may be 1.6 mm.

FIG. 4 is a diagram showing a schematic configuration of an example of the mold 105 in the simple matrix type liquid crystal display module (LCM) according to the embodiment of the present invention.
4A is a plan view showing a schematic configuration of the mold 105, and FIG. 4B is a cross-sectional view showing a cross section taken along line JJ ′ of FIG. 4A.

The mold 105 shown in FIG. 4 has a window portion 211, and outside the window portion 211, three protrusions (21
2, 213, 214) are formed, and the recess 21 formed by these three protrusions (212, 213, 214) is formed.
The convex portion 204 provided on the light guide plate 201 is fitted into the light guide plate 5.

Further, these three protrusions (212, 21
3, 214), a protrusion 217 having a recess 216 is also formed outside the three protrusions (212, 21).
3, 214) and the protrusion 217 form a groove 218.

FIG. 5 is a plan view showing a state where the light guide plate 201 and the cold cathode fluorescent lamp 108 shown in FIG. 3 are attached to the mold 105 shown in FIG.

As shown in FIG. 5, in the embodiment of the present invention, the convex portion 204 provided on the light guide plate 201 is fitted into the concave portion 203 formed in the mold 105, and the cold cathode fluorescent lamp 108 and the light guide plate 201 are fitted. And are attached to the mold 105.

Further, the cable 2 on the GND side is provided in the groove 217.
By arranging 05, the cable 205 is routed along the light guide plate 201 and is pulled out from the recess 216.

In this case, the cable 205 on the GND side
In addition, a white cable is adopted, and thereby, the irradiation light leaking from the convex portion 204 of the light guide plate 201 is reflected, and the brightness can be improved.

Here, the acrylic resin, which is the material of the light guide plate 201, has a shear strength about twice that of the plastic material, which is a mixture of polycarbonate and ABS resin, which is the material of the mold 105, and its convex shape. Since the area of the portion 204 (C shown in FIG. 3) can be made sufficiently large,
In the embodiment of the present invention, it becomes possible to improve the mechanical strength against an impact (F shown in FIG. 10).

Furthermore, since the convex portion 204 is formed outside the light guide plate 201, the liquid crystal display panel (LCD) 103 is formed.
It becomes possible to deal with narrowing of the frame.

However, in the embodiment of the present invention, since the projection 204 is formed on the light guide plate 201, the light emitted from the cold cathode fluorescent lamp 108 is scattered by the projection 204, so that the projection 204 is formed. The distribution of the irradiation light from the cold cathode fluorescent lamp 108 at the peripheral portion (portion B shown in FIG. 5) is not the same as that of the other portions. Therefore, in the embodiment of the present invention, the liquid crystal display panel ( The distribution of the light emitted from the cold cathode fluorescent lamp 108 on the LCD 103 becomes non-uniform.

In this case, as shown in FIG. 6A, on the surface of the light guide plate 201, a dot pattern for irradiating the liquid crystal display panel (LCD) 103 with the irradiation light from the cold cathode fluorescent lamp 108. 206 is formed.

FIG. 6 is a view for explaining the outline of the surface of the light guide plate 201.

In the embodiment of the present invention, the dot pattern 20 around the convex portion 204 of the light guide plate 201.
6, the size or density of the light guide plate 201 is adjusted.
The distribution of the irradiation light from the cold cathode fluorescent lamp 108 that is emitted from the liquid crystal display panel (LCD) 103 is made uniform over the entire surface of the liquid crystal display panel (LCD) 103.

As a result, the liquid crystal display panel (LCD) 1
03, it is possible to improve the luminance deviation in the effective display area and improve the display quality of the liquid crystal display panel (LCD) 103.

The cross-sectional shape of the dot pattern 206 is bowl-shaped or prism-shaped as shown in FIG. 6B, and the dot pattern 205 is also formed on the convex portion 204. .

In addition, the convex portion 20 formed on the light guide plate 201
By forming 4 at the center of gravity of the light guide plate 201,
This is advantageous when the light guide plate 201 is formed by injection molding.

FIG. 7 shows a schematic structure of another example of the mold 105 in the simple matrix type liquid crystal display module (LCM) according to the embodiment of the present invention.
FIG. 7A is a plan view showing a schematic configuration of another example of the mold 105, and FIG. 7B is K- of FIG. 7A.
It is sectional drawing which shows the cross section cut | disconnected by the K'line.

The mold 105 shown in FIG. 7 has a window 211, and a protrusion 217 is formed on the outside of the window 211. The protrusion 217 corresponds to the protrusion 204 provided on the light guide plate 201. The concave portion 215 is formed at the position to be formed.

The projection 217 has a cold cathode fluorescent lamp 1
A recess 216 into which the 08 is fitted is provided.

FIG. 8 is a plan view showing a state in which the light guide plate 201 and the cold cathode fluorescent lamp 108 shown in FIG. 3 are attached to the mold 105 shown in FIG.

In the case shown in FIG. 8 as well, the convex portion 204 provided on the light guide plate 201 is fitted into the concave portion 215 formed in the mold 105, so that the cold cathode fluorescent lamp 108 and the light guide plate 201.
And are attached to the mold 105.

In the embodiment of the present invention, the case where the present invention is applied to the STN type simple matrix type liquid crystal display panel has been described, but the present invention is not limited to this, and the present invention is a TFT type. Needless to say, it can be applied to the active type liquid crystal display panel.

As described above, the invention made by the present inventor is
Although the specific description has been given based on the embodiment of the invention, the invention is not limited to the embodiment of the invention and can be variously modified without departing from the scope of the invention. .

[0065]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows.

(1) According to the present invention, since the protrusion formed on the light guide plate is fitted into the recess provided on the frame-like body, the mechanical strength against impact can be improved. .

(2) According to the present invention, since the protrusion is formed on the outer side of the light guide plate, it is possible to sufficiently cope with the narrowing of the frame of the liquid crystal display panel. Can be reduced.

(3) According to the present invention, since the protrusion is formed at the center of gravity of the light guide plate, injection molding of the light guide plate forming the backlight is facilitated.

(4) According to the present invention, since the size or density of the dot pattern near the protrusion of the light guide plate is adjusted, the light source irradiates the liquid crystal display panel with the light source. It is possible to make the light distribution uniform over the entire surface of the liquid crystal panel, thereby improving the luminance deviation in the effective display area of the liquid crystal display panel and improving the display quality.

(5) According to the present invention, a liquid crystal display device can be manufactured at low cost.

[Brief description of drawings]

FIG. 1 is a perspective view showing a schematic configuration of a simple matrix type liquid crystal display module (LCM) which is an embodiment of the present invention.

FIG. 2 is an exploded perspective view showing a schematic configuration of the light guide plate assembly shown in FIG.

FIG. 3 is a perspective view showing a light guide plate in a simple matrix type liquid crystal display module (LCM) according to an embodiment of the present invention.

FIG. 4 is a diagram showing a schematic configuration of an example of a mold in the simple matrix type liquid crystal display module (LCM) according to the embodiment of the present invention.

5 is a plan view showing a state in which the light guide plate shown in FIG. 3 and a cold cathode fluorescent lamp are attached to the mold shown in FIG.

FIG. 6 is a diagram for explaining the outline of the surface of the light guide plate 201.

FIG. 7 is a diagram showing a schematic configuration of another example of the mold in the simple matrix type liquid crystal display module (LCM) according to the embodiment of the present invention.

8 is a plan view showing a state in which the light guide plate shown in FIG. 3 and a cold cathode fluorescent lamp are attached to the mold shown in FIG.

FIG. 9 is an exploded perspective view of a conventional simple matrix type liquid crystal display module (LCM).

10 is a plan view showing a state in which a cold cathode fluorescent lamp and a light guide plate are attached to a mold in the conventional simple matrix type liquid crystal display module (LCM) shown in FIG.

[Explanation of reference numerals] 101, 701 ... Upper frame, 102, 702 ... Silicon spacer, 103, 703 ... Liquid crystal display panel (LC
D), 104, 704 ... Driving circuit board, 105, 705
... Mold, 106, 706 ... Prism sheet, 10
7, 707 ... Light guide plate assembly, 108, 708 ... Cold cathode fluorescent lamp (cold cathode tube), 109, 709 ... Rubber bush, 1
10, 710 ... Cable connector, 111, 711 ... Silver reflection sheet, 112, 712 ... Lower frame, 113 ...
Bar spacer, 114 ... Flat cable, 115 ... Tape carrier package, 201, 713 ... Light guide plate, 20
2 ... Diffusion sheet, 203 ... Reflection sheet, 204 ... Convex portion,
205 ... Cable, 211 ... Window part, 212, 213, 2
14, 217 ... Projections, 215, 216 ... Recesses, 218
… Groove.

   ─────────────────────────────────────────────────── ─── Continued front page       (56) Reference JP-A-6-308489 (JP, A)                 JP-A-7-56170 (JP, A)                 Actual development Sho 59-68385 (JP, U)                 Actual Kaihei 5-69734 (JP, U)

Claims (4)

(57) [Claims] 1. A liquid crystal display device comprising: a liquid crystal display panel; and a backlight for illuminating the liquid crystal display panel, wherein the backlight is a light guide plate, and a first side surface of the light guide plate and the vicinity thereof. And a frame-shaped body that houses the light source and the light guide plate, wherein the light guide plate has a surface and a second crossing the first side surface.
A side surface of the light guide plate, and a protrusion that extends outward from the second side surface, and a dot pattern for irradiating the liquid crystal display panel side with light emitted from the light source is formed on the surface of the light guide plate. , the protrusion includes a protrusion table surface that is continuous with the surface of the light guide plate, wherein the protrusion surface, the dot pattern shape
The liquid crystal display device is characterized in that the frame-shaped body has a window portion and a concave portion provided around the window portion and into which the protrusion is inserted. 2. The backlight has a prism sheet.
And the prism sheet and the second side surface of the light guide plate are
The liquid crystal display device according to claim 1, wherein the liquid crystal display device has a side extending in the same direction, and a protrusion protruding outward from the side . 3. A liquid crystal display panel and a backlight for illuminating the liquid crystal display panel.
In the liquid crystal display device, the backlight includes a light guide plate, a light source disposed near a first side surface of the light guide plate, and a frame-shaped body that houses the light source and the light guide plate. The light guide plate has a second side surface that intersects with the first side surface.
And a protrusion that extends from the second side surface to the outside, and the surface of the light guide plate is irradiated with the irradiation light from the light source.
Pattern is formed to irradiate the crystal display panel side
And the protrusion is a protrusion surface that is continuous with the surface of the light guide plate.
And the dot pattern is formed on the surface of the protrusion.
The frame-shaped body is formed on the window portion and around the window portion, and
And a recess into which the protrusion is inserted, and the shear strength of the light guide plate is greater than the shear strength of the frame-shaped body.
Stronger liquid crystal display device comprising Ri. 4. The backlight is a prism sheet.
And the prism sheet is provided with the second side surface of the light guide plate.
The liquid crystal display device according to claim 3, wherein the liquid crystal display device has a side extending in the same direction, and the side has a protrusion protruding outward from the side .