JPH1054987A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the luminance of light extremely large so as to improve utilization efficiency by arraying a condensing lens on the upper surface of the diffusing plate of back light so that the condensing lens corresponds to each picture element electrode of an LCD panel. SOLUTION: After light is radiated from a fluorescent lamp 11, the radiated light is diffused by a light transmission plate 13, so that the light is prevented from leaking outside. Then, the light is diffused by the plate 14 attached on the plate 3, and the diffused light is made incident on a condensing plate 16. The light made incident by condensers 16-1 to 16-3... constituting the plate 16 is concentrated. Since the condensers 16-1 to 16-3... are arrayed under the corresponding picture element electrodes 18-1 to 18-3..., the light concentrated by the condensers 16-1 to 16-3... is made incident on the corresponding electrodes 18-1 to 18-3... of the LCD panel including a thin film transistor and the electrode 18. Thus, the quantity of the light made incident on the respective electrodes 18-1 to 18-3... is more increased than that of a conventional LCD device which is not provided with the plate 6.

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,
In particular, the present invention relates to a backlight unit structure of a liquid crystal display device capable of improving light efficiency.

[0002]

2. Description of the Related Art Present display elements are rapidly being used in various flat panel display devices in place of the bulky CRTs used up to now. Among them, the technology of the liquid crystal display device, which is advantageous in terms of screen size, thickness and image quality, has been remarkably developed, and has been developed in the field of camcorders, desktop computers and the like.
e) Became better. In particular, an active matrix type liquid crystal display device that combines liquid crystal technology and semiconductor technology has a memory function for the electro-optical effect of liquid crystal by adding an active element having nonlinear characteristics to each pixel arranged in a matrix form. Device.

[0003] Unlike a CRT, such a liquid crystal display device does not include a light emitting unit, and therefore requires a light source other than a liquid crystal screen.

[0004] The backlight unit of the fluorescent lamp LCD device is classified into a direct type backlight unit and an edge light type backlight unit (edge-light) according to the installation position of the fluorescent lamp used as a light source. The direct-type backlight unit has a structure in which light generated by a fluorescent lamp is made uniform by a diffusion plate and then incident on a liquid crystal panel. On the other hand, the edge light type backlight unit has a structure in which light from a fluorescent lamp is incident on a liquid crystal panel through a light guide plate.

A typical example of a conventional edge light type backlight unit is shown in FIG.

Referring to FIG. 3, a fluorescent lamp 1 is mounted and installed on a side surface of a light guide plate 3 that scatters and equalizes light, and the fluorescent lamp 1 is surrounded by a lamp housing 2. Here, the lamp housing 2 supports the fluorescent lamp 1 and prevents light emitted from the fluorescent lamp 1 from leaking to the side surface. The diffusion plate 4 is a polarizing plate at the lower part of the LCD panel of a structure composed of liquid crystal interposed between the upper surface of the light guide plate 3 and a substrate (not shown), on which thin film transistors and pixel electrodes are arranged. And is located between. The reflection plate 5 prevents light generated from the fluorescent lamp 1 from leaking to the outside. That is, the reflection plate 5 functions to prevent light from leaking to the lower part of the light guide plate 3.

In such a conventional backlight unit, light emitted from the fluorescent lamp 1 is incident on the LCD panel through the diffusion plate 4 disposed above the light guide plate 3 to form a predetermined image. You. At this time, the light emitted from the fluorescent lamp 1 is prevented from leaking to the outside by the reflection plate 5 and is incident on the light guide plate 3 to be uniformly scattered.

In the LCD having the above-described backlight unit, the light is made uniform by the diffusion plate 4 of the light guide plate 3 and then incident on the LCD panel. However, since the conventional backlight unit does not include a unit for concentrating the uniformed light, the light incident on the LCD panel is not concentrated. As a result, there is a problem that the efficiency of using light emitted through the LCD panel is only about 6%.

[0009]

SUMMARY OF THE INVENTION Accordingly, it is a primary object of the present invention to provide a liquid crystal display device capable of increasing the use efficiency of light emitted from a backlight unit and passing through an LCD panel for light emitted from the backlight unit. It is.

[0010]

According to the present invention, there is provided a liquid crystal display, comprising: a backlight unit for projecting light onto an LCD panel including pixel electrodes; A liquid crystal, comprising a plurality of condenser lenses inserted between the unit and the LCD panel, and a condenser means for concentrating light from the backlight unit to each pixel electrode of the LCD panel. A display device is provided. In the present invention, the light radiated through the diffusion plate is condensed by arranging a condenser lens on the upper surface of the diffusion plate corresponding to the position of each pixel of the liquid crystal panel. Thereby, the illuminance of the light is maximized, and the light is transmitted to the liquid crystal panel, so that the utilization efficiency is increased.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a perspective view of a backlight unit provided with a condenser lens above a diffusion plate according to the present invention, and FIG. 2 is a liquid crystal display provided with a liquid crystal panel above a backlight unit according to the present invention. It is a perspective view of an element.

In FIG. 1, a lamp housing 12 for preventing light from leaking out of the backlight unit is provided around the fluorescent lamp 11. The diffusion plate 14 is conventionally disposed between the upper surface of the light guide plate 13 and a polarizing plate (not shown), and the polarizing plate is formed on a lower surface of an LCD panel (not shown). The light collector 16 is formed on the upper surface of the diffusion plate 14 according to the present invention. Although not shown, the light collector 16 has the same arrangement as the pixel electrodes so as to correspond to the respective pixel electrodes of the LCD panel. The reflection plate 15 prevents light generated from the fluorescent lamp 11 from leaking to the outside. That is, the reflection plate 15 serves to prevent light from leaking to the lower part of the light guide plate 13. The light collector 16 is formed on the upper surface of the diffusion plate 14 and has the same arrangement as the pixel electrodes.

The above light source includes a cold cathode fluorescent lamp (C
CFL) and a halogen cathode fluorescent lamp (HCFL).

FIG. 2 is an exploded perspective view of the backlight unit of FIG. 1 and the LCD panel 17 thereon, showing that each condenser lens is arranged at an overlapping position corresponding to each pixel of the LCD panel. Show.

In FIG. 2, after the light is emitted from the fluorescent lamp 11, the emitted light is scattered by the light guide plate 13. Light leakage to the outside is prevented. Thereafter, the light is diffused by the diffusion plate 14 attached on the light guide plate 3.
Thereafter, the diffused light is incident on the light collector 16, and each of the light collecting lenses 16-1, 16-2, 16-constituting the light collector 16
.. Are focused. Light collector 1
6 is a large number of condenser lenses 16-1, 16-2, 16-3.
, Including each condenser lens 16-1, 16-2, ...
Are the corresponding pixel electrodes 18-1, 18-2,.
・ ・ Because it is arranged at the bottom of
The light concentrated by 6-2, 16-3,... Is incident on the corresponding pixel electrodes 18-1, 18-2, 18-3,. As a result, each pixel electrode 18-1, 18-2,
18-3... Greatly increases as compared with a conventional LCD device having no light collector 6.

[0017]

As described above, according to the present invention, the illuminance of light is maximized by arranging a condenser lens on the upper surface of the diffusion plate of the backlight so as to correspond to each pixel electrode of the LCD panel. Thereby, the light use efficiency is improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a backlight unit having a condenser lens provided above a diffusion plate according to the present invention.

FIG. 2 is an exploded perspective view of a liquid crystal display device having a liquid crystal panel on an upper portion of a backlight unit according to the present invention;

FIG. 3 is a perspective view of a backlight unit provided in a general liquid crystal display device.

[Explanation of symbols]

 1,11 Fluorescent lamp 2,12 Lamp housing 3,13 Light guide plate 4,14 Diffusion plate 5,15 Reflection plate 16 Light collector 16-1,16-2,16-3 ... Light collector lens 18-1,18 -2, 18-3 ... Pixel electrode

Claims (8)

[Claims] 1. A liquid crystal display device, comprising: a backlight unit for projecting light onto an LCD panel including pixel electrodes; and a plurality of condenser lenses inserted between the backlight unit and the LCD panel. A liquid crystal display device comprising: a light collecting means for concentrating light from the backlight unit to each pixel electrode of the LCD panel. 2. The backlight unit according to claim 1, further comprising: a light source; a lamp housing surrounding the light source to prevent the light source from leaking outside; and a light guide plate for guiding light from the light source. 2. The liquid crystal display device according to 1. 3. The liquid crystal display device according to claim 2, wherein the backlight unit includes a diffusion plate for diffusing light passing through the light guide plate. 4. The liquid crystal display device according to claim 3, wherein the backlight unit includes a light reflection plate for preventing light from leaking from the diffusion plate to the outside. 5. The liquid crystal display device according to claim 2, wherein the light source is a fluorescent lamp. 6. The liquid crystal display of claim 5, wherein the fluorescent lamp is a cold cathode fluorescent lamp (CCFL). 7. The liquid crystal display according to claim 5, wherein the fluorescent lamp is a halogen cathode fluorescent lamp (HCFL). 8. The light condensing means is arranged below the corresponding pixel electrode of the LCD panel, and the light condensed by the light condensing means is incident on the corresponding pixel electrode. Item 2. The liquid crystal display device according to item 1.