JPH0618881A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To eliminate a luminance variance on the display surface, and also, to thin the device by using a fluorescent display tube for a back light instead of a fluorescent lamp. CONSTITUTION:A signal inputted to a liquid crystal display device is driven by a liquid crystal driver 13 of a drain side and a liquid crystal driver 14 of a gate side, irradiated by a fluorescent display tube 15, and displayed of liquid crystal panel 12. That is, a filament 8 is driven by an AC power source, a bias is applied to a control grid 9, and a bias is applied to a conductive layer 10 provided with a phosphor layer. The conductive layer 10 is protected by a ceramic substrate 11. An electron radiated from the filament 8 is controlled by the grid 9, and accelerated and reaches the conductive layer 10 to which a voltage of scores of volts is applied. In that case, when the phosphor layer emits light, its emitted light passes through a TFT panel 2 and by driving of the liquid crystal driver 13, a switching operation of a liquid crystal 3 emits it to the outside of a color filter 1.

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, it relates to the structure of the backlight.

[0002]

2. Description of the Related Art A conventional liquid crystal display device has a structure as shown in FIG. FIG. 2A is a perspective view and FIG.
Is a cross-sectional view taken along line BB '. As shown in the figure, a color filter 1 forming a liquid crystal panel and a TFT for controlling display pixels
In order to make the panel 2 and the liquid crystal 3 enclosed between them, the driver 4 for driving the TFT panel 2, the backlight 5 which is the light source 5, the fluorescent lamp 6 and the fluorescent lamp 6 constituting the backlight 5 uniform, It is composed of the diffusing plate 7.

The operation of the conventional example will be described.
The signal input from the outside is input to the liquid crystal driver 4 and processed to drive the TFT panel 2. The driven liquid crystal is normally (normally white) in the off state (the liquid crystal is not biased), and when driven, the liquid crystal 3 cuts off the light emitted from the backlight 5. The backlight 5 transmits the light from the fluorescent lamp 6 to the TFT panel 2 via the diffusion plate 7, the liquid crystal 3 controls the passage / blocking, and the light is emitted to the outside via the color filter 1.

[0004]

In this conventional liquid crystal display device, since a fluorescent lamp is used, the thickness of the backlight is large, and even if a diffuser plate is used, the liquid crystal display device can be made thinner.
There was a problem that there was a clear difference in brightness on the screen. Further, this problem was particularly remarkable in the color liquid crystal display device.

[0005]

A liquid crystal display device of the present invention comprises a liquid crystal panel, a drive circuit for the liquid crystal panel, and a fluorescent display tube for making the display of the liquid crystal panel visible.

[0006]

The present invention will be described below with reference to the drawings. FIG. 1A is a perspective view of an embodiment of the present invention,
FIG. 1B is a sectional view taken along the line AA ′ of FIG. A signal input to the liquid crystal display device is driven by the liquid crystal driver 13 on the drain side and the liquid crystal driver 14 on the gate side, and illuminated by the fluorescent display tube 15 to display the liquid crystal panel 12. Next, the operation of the present invention will be further described. The filament 8 is driven by an AC power source, the control grid 9 is biased, and the bias is applied to the conductive layer 10 provided with the phosphor layer. The conductive layer 10 is protected by the ceramic substrate 11. The electrons radiated from the filament 8 are accelerated by the grid 9 and reach the conductive layer 10 to which a voltage of several tens of volts is applied. At that time, when the phosphor layer emits light, the emitted light passes through the TFT panel 2 and is driven by the liquid crystal driver 13 to be emitted to the outside of the color filter 1 by the switching operation of the liquid crystal 3.

The TFT panel 2 has a fluorescent display tube 15
It also functions as a display side glass. The current fluorescent lamp type has a thickness of about 12 mm, but when a fluorescent display tube is used, the thickness becomes about 6 mm.

[0008]

As described above, the present invention eliminates the variation in the brightness of the display surface by using the fluorescent display tube instead of the fluorescent lamp conventionally used for the backlight.
Further, since it can be made thin, it has an effect of being effective for a display unit of a notebook type personal computer or the like.

[Brief description of drawings]

FIG. 1A is a perspective view of an embodiment of the present invention, and FIG. 1B is a sectional view of AA ′ of the embodiment of the present invention.

2A is a perspective view of a conventional example, and FIG. 2B is a B of the conventional example.
It is a sectional view of B '.

[Explanation of symbols]

 1 Color Filter 2 TFT Panel 3 Liquid Crystal 4 Liquid Crystal Driver 5 Backlight 6 Fluorescent Lamp 7 Diffusion Plate 8 Filament 9 Grid 10 Conductive Layer with Fluorescent Layer 11 Ceramic Substrate 12 Liquid Crystal Panel 13 Drain Side Liquid Crystal Driver 14 Gate Side Liquid Crystal Driver 15 Fluorescent Display tube

Claims (1)

[Claims] 1. A liquid crystal display device having a liquid crystal display panel, a drive circuit, and a backlight for making the screen of the display panel visible, wherein a fluorescent display tube is used as the backlight. Liquid crystal display device.