JP3067430B2 - Color 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 color liquid crystal display device used for a color liquid crystal television, a color liquid crystal display of a computer, and the like.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional example of this type of color liquid crystal display device. This color liquid crystal display device has a diffusion plate 20 as a backlight behind a color liquid crystal panel 10.
It has a structure in which a plurality of fluorescent lamps 22 and reflectors 24 are arranged.

A color liquid crystal panel 10 has 90 liquid crystal molecules.
Transparent electrodes 12 and 13 above and below liquid crystal 11 twisted
Are provided, and glass substrates 14 and 15 are provided above and below the polarizing plate.
6 and 17 are provided.

The transparent electrodes 12 and 13 may be a number of stripe-shaped electrodes orthogonal to each other, or one of the transparent electrodes 13 may be a number of pixel electrodes and the other may be a transparent electrode 12.
May be a common electrode, but in any case, a large number of pixels arranged in a matrix are formed between the upper and lower transparent electrodes 12 and 13.

By controlling the voltage applied between the transparent electrodes 12 and 13, each pixel transmits or blocks light by a shutter action utilizing the electro-optical anisotropy of the liquid crystal 11.

Further, for color display, red (R),
A color filter 18 in which the three primary colors of green (G) and blue (B) are arranged corresponding to each pixel is used.
2 and the glass substrate 14. In order to obtain a high contrast ratio between the colors of the color filter 18,
A light shielding layer (black matrix or black stripe) 19 is provided.

As described above, the conventional color liquid crystal display device is
Color display is performed by using the fluorescent lamp 22 as a light source and passing the light transmitted through the liquid crystal 11 through the color filter 18.

The color filter 18 is formed by applying a dyeing substrate onto a substrate, exposing the substrate to a mask, developing the pattern, and applying a material colored with a dye or pigment to the substrate. And a printing method of patterning by screen printing or flexographic printing.

[0009]

However, in the above-mentioned color liquid crystal display device, the fluorescent lamp 22 is used as a light source and the liquid crystal 1 is used.
Since the light transmitted through 1 passes through the color filter 18, the transmittance of the color filter 18 is reduced. for that reason,
This leads to a decrease in luminance, which is an important element of the image quality characteristics. In order to increase the luminance, it is necessary to increase the power of the light source, which causes a problem that power consumption cannot be reduced.

Accordingly, the present invention provides a color liquid crystal display device which enables color display without using a color filter causing a decrease in luminance, thereby achieving both luminance and low power consumption. Its primary purpose is to provide.

[0011]

In order to achieve the above object, a color liquid crystal display device according to the present invention comprises a liquid crystal in which transparent electrodes are provided on both upper and lower sides of a liquid crystal to form a large number of pixels arranged in a lattice. A panel and a plurality of first to third optical fibers with a condensing lens arranged along the back of each pixel row of the liquid crystal panel, wherein one of the first to third optical fibers with a condensing lens is provided. And a white light source for allowing white light to be incident from one end side into all of these optical fibers with a condensing lens. optical fiber, the light incident on one end to those colored red a fiber emerging from the side surface, substantially parallel toward the light emitted from the optical fiber to a corresponding pixel row of the liquid crystal panel Made by along the emitted thereby converging lens, each of the second condensing lens with the optical fiber, to those comprising an optical fiber for emitting light incident on the one end side from the side was colored in green, out the optical fiber made with light and along substantially parallel to the emitted thereby converging lens toward the corresponding pixel row of the liquid crystal panel, and the third condenser lens with optical fibers, the side of the light incident on one end
An optical fiber that is emitted from a surface and is colored blue, and a condensing lens that emits light emitted from the optical fiber substantially parallel to a corresponding pixel row of the liquid crystal panel is provided. And

[0012]

According to the above construction, the light emitted from the white light source is transmitted by the first through third optical fibers with condenser lenses.
The light is guided to each corresponding pixel column of the liquid crystal panel, and is incident on each pixel column as substantially parallel light.

In addition, since the first to third optical fibers with a converging lens use red, green and blue colored optical fibers, respectively, light from a white light source is not condensed by the first to third condensing lenses. While passing through the optical fiber with the lens, it is converted to red light, green light and blue light, respectively.
These are incident on each pixel column.

The combination of the first to third optical fibers with a condensing lens and the liquid crystal panel makes it possible to form a stripe type in which red, green and blue are arranged in a stripe without using a color filter as in the prior art. Color pattern arrangement can be realized. That is, color display can be performed.

[0015]

FIG. 1 is a schematic sectional view partially showing a color liquid crystal display device according to an embodiment of the present invention. FIG.
FIG. 2 is a schematic rear view of the entire color liquid crystal display device of FIG. 1.

This color liquid crystal display device has a so-called black and white liquid crystal panel 30 and a number of first liquid crystal panels 30 provided behind the panel.
To third optical fibers with condenser lens 40a to 40c
And all of these optical fibers 40a-
The light source 40c includes a white light source 46 for allowing white light to enter from one end thereof.

The liquid crystal panel 30 is provided with transparent electrodes 32 and 33 above and below a liquid crystal 31 in which liquid crystal molecules are twisted by 90 degrees, and further provided with glass substrates 34 and 35 above and below.
Further, a polarizing plate 36 and a polarizing plate 37 whose polarization directions are orthogonal to each other are provided on the upper and lower sides.

The transparent electrodes 32 and 33 may be a large number of striped electrodes orthogonal to each other, or one of the transparent electrodes 33 may be a large number of pixel electrodes and the other may be a transparent electrode 32.
May be a common electrode, but in any case, a large number of pixels arranged in a lattice are formed between the upper and lower transparent electrodes 32 and 33. The dashed line in FIG. 2 illustrates only three pixel columns 38 formed in this way.

By controlling the voltage applied between the transparent electrodes 32 and 33, each pixel transmits or blocks light by a shutter action utilizing the electro-optical anisotropy of the liquid crystal 31.

The driving method of each pixel may be a simple matrix method in which each pixel is directly driven by an external signal, or an active matrix method in which each pixel performs a kind of storage operation using a thin film transistor (TFT) or the like. .

Each of the first to third optical fibers with a condenser lens 40a to 40c is connected to the liquid crystal panel 3 as described above.
0 along each of the pixel rows 38, and the first to third optical fibers 40a to 40c with a condenser lens.
0c are arranged one by one.

Each first optical fiber 40a with a condenser lens
Converts light incident on one end side along the length direction (that is,
From the side. The same applies to the optical fiber 41a to be emitted and colored red.
Of light 44 from the corresponding pixel column 38 of the liquid crystal panel 30
Nearly parallel to (ie, do not diverge and focus).
The same applies to the following). The optical fiber 41a is typically a colored glass fiber.

Each second optical fiber with condenser lens 40b
Is an optical fiber 41b that emits light incident on one end side along the length direction and is colored green,
The light 44 emitted from the optical fiber 41b is transmitted to the liquid crystal panel 3
It has a structure in which a condenser lens 42b that emits light substantially in parallel toward the corresponding pixel row 38 of 0 is arranged. The optical fiber 41b is typically a colored glass fiber.

Each third optical fiber 40c with a condenser lens
Is an optical fiber 41c that emits light incident on one end side along the length direction and is colored blue,
The light 44 emitted from the optical fiber 41c is transmitted to the liquid crystal panel 3
It has a structure in which a condenser lens 42c that emits light substantially parallel to the corresponding pixel row 38 of 0 is arranged. This optical fiber 41c is typically a colored glass fiber.

The white light source 46 comprises, for example, a white fluorescent lamp and a reflector.

In this color liquid crystal display device, the light emitted from the white light source 46 is transmitted to the liquid crystal panel 3 by the first to third optical fibers 40a to 40c with condenser lenses.
The light is guided to each corresponding pixel row 38 of 0, and is incident on each pixel row 38 as substantially parallel light.

Further, since the first to third optical fibers with a condenser lens 40a to 40c use red, green and blue colored optical fibers 41a to 41c, respectively, the light from the white light source 46 is 1st to 3rd
Are respectively converted into red light, green light, and blue light while passing through the optical fibers 40a to 40c with condenser lenses.

The combination of the first to third optical fibers 40a to 40c with a condenser lens and the liquid crystal panel 30 enables red (R) and green (G) without using a color filter as in the related art. And blue (B) in a stripe pattern. That is, color display can be performed.

Further, in this color liquid crystal display device, since the color filters are not used, the decrease in light transmittance is small, and the decrease in light transmittance in the optical fibers 41a to 41c constituting the respective optical fibers 40a to 40c with condenser lenses. Even if it is present, the light is collected by the condenser lenses 42a-4
Since the effective use of light can be compensated by 2c, the color liquid crystal display device has higher luminance than the conventional color liquid crystal display device when compared with the same power consumption.
Conversely, if the luminance is the same, the color liquid crystal display device requires lower power consumption. That is, both luminance and low power consumption can be achieved.

In this color liquid crystal display device, since the light 44 is emitted from the respective optical fibers 40a to 40c with condenser lenses almost in parallel, even if the light-shielding layer 19 as in the conventional example is not provided, the height can be increased. A contrast ratio can be obtained. Therefore, it is not necessary to provide the light-shielding layer 19, so that the manufacturing process can be simplified.

[0031]

As described above, according to the present invention, the combination of the white light source, the first to third optical fibers with a condensing lens and the liquid crystal panel as described above eliminates the need for a color filter as in the prior art. However, color display can be performed.

Further, since the color filter is not used, the decrease in light transmittance is small, and even if there is a decrease in light transmittance in the colored optical fiber constituting each optical fiber with a condensing lens, the light is reduced by the condensing lens. Can be compensated for by using light effectively, so that both luminance and low power consumption can be achieved.

Also, since the light emitted from each optical fiber with a condenser lens is emitted almost in parallel, a high contrast ratio can be obtained without providing a light-shielding layer as in the conventional example. The manufacturing process can be simplified.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view partially showing a color liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a schematic rear view of the entire color liquid crystal display device of FIG.

FIG. 3 is a schematic sectional view partially showing an example of a conventional color liquid crystal display device.

[Explanation of symbols]

 Reference Signs List 30 liquid crystal panel 31 liquid crystal 32, 33 transparent electrode 40a first optical fiber with condenser lens 40b second optical fiber with condenser lens 40c third optical fiber with condenser lens 41a-41c optical fiber 42a-42c condenser lens 46 white light source

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-58-149088 (JP, A) JP-A-3-1718104 (JP, A) JP-A-3-15022 (JP, A) JP-A-55-15088 29892 (JP, A) JP-A-5-134252 (JP, A) JP-A-2-100201 (JP, U) JP-A-2-19002 (JP, U) (58) Fields investigated (Int. ⁷ , DB name) G02F 1/13357 G02B 6/00 306 G02B 6/04

Claims (1)

(57) [Claims] 1. A liquid crystal panel in which transparent electrodes are provided on both upper and lower sides of a liquid crystal to form a large number of pixels arranged in a lattice, and arranged behind each pixel row of the liquid crystal panel. A plurality of first to third optical fibers with a condenser lens, wherein the first to third optical fibers with a condenser lens are arranged so as to form a group, and A white light source for allowing white light to be incident from one end of the optical fiber, and each of the first optical fibers with a condensing lens is an optical fiber that emits the light incident on one end from the side surface and has a red color. And a condenser lens for emitting light emitted from the optical fiber substantially parallel to a corresponding pixel row of the liquid crystal panel, and each second optical fiber with a condenser lens is , The light incident on one end side
An optical fiber that is emitted from the surface and is colored green, and a condensing lens that emits light emitted from the optical fiber substantially parallel to a corresponding pixel row of the liquid crystal panel, and The third optical fiber with a condenser lens is an optical fiber that emits light incident on one end side from the side surface and is colored blue, and the light emitted from the optical fiber is applied to a corresponding pixel column of the liquid crystal panel. A color liquid crystal display device comprising a condensing lens that emits light in a substantially parallel direction.