JPH0262515A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To suppress a decrease in display quality due to the coloring of a display panel when the twist angle of liquid crystal molecules is increased and to improve the display quality by providing a light source which emits coloring light of the complementary color to the coloring of the liquid crystal display panel behind the liquid crystal panel. CONSTITUTION:The liquid crystal display panel 1 which is increased in twist angle changes generally with an applied voltage, but is colored in blue or green. A light source of the complementary color to the coloring of the display panel 1 is used as the light source 2 provided behind the display panel 1. Namely, a light source 2 of red is used for the display panel 1 which is colored in green and a light source 2 of green and red is used for the display panel 1 which is colored in blue. Thus, the bright liquid crystal display device with a color tone close to white is obtained. Further, a color filter 5 may be provided between a light source 2 of white and the liquid crystal panel 1 and backlighting is only devised to improve the display quality.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a liquid crystal display device widely used in various display terminals.

BACKGROUND OF THE INVENTION Liquid crystal display devices have been widely used in the past for displays on calculators, toys, various home appliances, computers, word processors, and other information devices, large displays, and the like.

During these displays, a large amount of information is displayed, especially when used for displaying on information equipment terminals, so a multi-duty multiplex motion system must be adopted.For this reason, the conventional TN type display method However, as a solution to the above-mentioned problems, a display method in which the twist angle of liquid crystal molecules is increased in the conventional TI method has been proposed. Quality has been improved.

Problems to be Solved by the Invention While the viewing angle has increased in the above-mentioned improved display system, a new problem has arisen: as the twist angle increases, the display panel becomes colored and the display quality deteriorates. It's here.

Means for Solving the Problems In the present invention, as a means for solving the coloring problem of the improved display system described above, a light source having an emission color complementary to the coloring described above is provided behind the liquid crystal display panel. .

Effect As mentioned above, by providing a light source that produces a color complementary to the coloring of the liquid crystal display panel behind it, a liquid crystal display device that is visually close to white can be obtained, and the display quality can be significantly improved. It is something.

Example An overview of the present invention will be explained with reference to FIGS. 1 to 3.

FIG. 1 is a schematic diagram showing a cross section of a liquid crystal display device according to one embodiment of the present invention, and FIGS. 2 and 3 are schematic diagrams showing a cross section of a liquid crystal display device according to other embodiments.

1 in FIG. 1 is a liquid crystal display panel with a large twist angle, and the color changes depending on the applied voltage, but is generally colored blue to green. Reference numeral 2 denotes a light source provided on the back of the liquid crystal display panel 1, and the color of the emitted light is complementary to the coloring of the liquid crystal display panel 1. In other words, for the liquid crystal display panel 1 colored green, the red light source 2
The liquid crystal display panel 1 colored blue requires a red light source 2. Suitable light sources 2 for this purpose include fluorescent lamps that emit the above two colors, XL (electroluminescent) light emitters, etc.; Any light-emitting body may be used.

Note that, if necessary, a reflecting plate 3 may be provided at the back of the light source. Further, 4 is a polarizing plate.

FIG. 2 shows another embodiment of the present invention, in which a white light source 2 is covered with a color filter 6.

FIG. 3 also shows another embodiment of the present invention, in which a polarizing plate 6 having a color filter function is installed between the light source 2 and the liquid crystal display panel 1.

If the light source 2 has a flat plate shape, it has the effect of reducing the thickness of the entire panel, but from the viewpoint of display quality, there is no need to be particularly particular about the shape.

Hereinafter, specific examples will be described.

(Example 1) A liquid crystal display panel 1 was manufactured by a conventional method. However, the interval between the upper and lower electrodes was 4.6μ, and the upper and lower twist angle was 270 degrees. This liquid crystal display panel 1 exhibited a pale edge color under normal crossed Nicols conditions.

Next, as shown in Fig. 1, a translucent polarizing plate 4 is attached to the back of this liquid crystal display panel 1, and it is placed in front of a fluorescent lamp that emits blue, red, and two-color light, and a normal polarizing plate 4 is attached to the front. Oto9
When the liquid crystal display device was turned on, a bright liquid crystal display device with a color close to white was obtained.

(Example 2) In Example 1, a commonly used three-color fluorescent lamp was used instead of the two-color fluorescent lamp, and the polarizing plate 4 and the light source 2 at the rear of the color filter (magenta) were In this case as well, a liquid crystal display device with a color tone close to white with a slight reddish tinge was obtained.

Effects of the Invention As can be seen from the above explanation, the present invention can provide a liquid crystal display device with good display quality by simply adding a modification to the backlight illumination of a normal liquid crystal display panel, and has a great industrial effect. be.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram showing a cross section of an example of a liquid crystal display device according to the present invention, and FIGS. 2 and 3 are conceptual diagrams showing a cross section of another embodiment. 1...---Liquid crystal display panel, 2...Light source,
3...Reflector, 4...Polarizing plate. Figure 1 Figure 2 Figure 3

Claims (2)

[Claims] (1) A liquid crystal display device comprising a light source behind a liquid crystal display panel that emits colored light that is complementary to the coloring of the liquid crystal display panel. (2) A liquid crystal display device characterized in that a color filter is provided behind the liquid crystal display panel and between the light source and has a complementary color to the coloring of the liquid crystal display panel.