JPH07287229A - Color liquid crystal display device - Google Patents

Abstract

PURPOSE:To reduce the loss of light energy and to display a color image with sufficient luminance by separating light source light to plural kinds of luminous fluxes having a different wavelength band and making them incident on different areas of a liquid crystal display panel. CONSTITUTION:A prism array 8 separates respective stripe-state luminous fluxes (a) from a light source, which are made parallel rays by a luminous flux correcting lens array 7, to plural kinds of stripe-state light beams R, G and B having the different wavelngth band and turning to a different direction by every wavength band. The prism array 8 is formed by arraying slender optical prisms 8a as many as the concave lenses of the lens array 7 to be in parallel corresponding to the stripe state luminous fluxes (a). The cylindrical lenses 9a of the luminous flux correcting lens array 9 correct the stripe-state luminous fluxes (a) spectrally split by the prism array 8 to the parallel beams to make the red light beam R, the green light beam G and the blue light B of the respective luminous fluxes incident on each line of picture element display part of the liquid crystal display panel 1.

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 for performing color display.

[0002]

2. Description of the Related Art As a liquid crystal display device, for example, a dot matrix type liquid crystal display panel is used, the liquid crystal display panel is illuminated from the back side thereof, and an image (for example, a television image or the like) is emitted by light emitted from the liquid crystal display panel. ) Is displayed.

In this type of liquid crystal display device, for example, there is a liquid crystal projector that magnifies and projects the image light emitted from the liquid crystal display panel onto a projection surface such as a screen by a projection lens. The display image on the liquid crystal display panel can be enlarged and viewed.

There are two types of liquid crystal display devices, one for projecting a black and white image and the other for projecting a color image. As a color liquid crystal display device for projecting a color image, a color liquid crystal display is conventionally used on a liquid crystal display panel. A panel is known.

The above-mentioned color liquid crystal display panel is one in which color filters of three colors of red, green and blue are alternately arranged corresponding to each pixel display portion, and the color filter is generally one of the liquid crystal display panels. It is provided on the inner surface of one of the substrates.

[0006]

However, the color liquid crystal display panel displays a color image by coloring the light (white light) from the light source by absorbing the specific wavelength light in the color filter. About 70% or more of light energy is absorbed in the color filter.

Therefore, in the conventional color liquid crystal display device using this color liquid crystal display panel, the brightness of the light (color image light) emitted from the liquid crystal display panel is greatly reduced, and the display is considerably darkened. .

Therefore, in the conventional color liquid crystal display device, in order to obtain a display with sufficient brightness, the light emission energy of the light source must be three times or more that of the liquid crystal display device for displaying a black and white image. When the light emission energy of the light source is increased, not only the heat generation temperature of the light source rises, but also the liquid crystal display panel generates heat due to the absorption of light by the color filter, so strict heat measures are also taken to prevent the temperature rise of the liquid crystal display panel. Was needed.

The present invention has been made in view of the above situation, and an object thereof is to reduce a loss of light energy and to obtain a color having sufficient brightness without increasing the light emission energy of a light source. An object is to provide a color liquid crystal display device capable of displaying an image.

[0010]

A color liquid crystal display device according to the present invention includes a light source, a light separating means for separating light from the light source into a plurality of kinds of light fluxes having different wavelength ranges, and the light separating means. A single liquid crystal display panel in which the plurality of types of light fluxes are incident on different regions is provided.

[0011]

In the color liquid crystal display device of the present invention, the light from the light source is separated into a plurality of kinds of light fluxes having different wavelength ranges by the light separating means, and the plurality of kinds of light fluxes are made incident on a single liquid crystal display panel. A color image is displayed on this liquid crystal display panel.

According to this color liquid crystal display device, the light from the light source is separated by the light separating means to obtain a plurality of kinds of light fluxes having different wavelength ranges, that is, a plurality of kinds of color light fluxes, and the light fluxes of the respective colors are displayed on the liquid crystal display. Since the light is incident on the panel, it is not necessary to provide a color filter for coloring light on the liquid crystal display panel. Therefore, light energy is largely lost due to absorption of light of a specific wavelength unlike the case of coloring with a color filter. Moreover, most of the light from the light source is incident on the liquid crystal display panel as a plurality of types of light fluxes having different wavelength ranges, so that the light from the light source can be used without waste.

Therefore, according to the color liquid crystal display device of the present invention, it is possible to reduce the loss of light energy and display a color image with sufficient brightness without increasing the light emission energy of the light source. Since it is not necessary to increase the light emission energy of the light source, the heat generation of the liquid crystal display panel can be suppressed low.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a color liquid crystal projector will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram of a color liquid crystal projector, FIG. 2 is an enlarged view of a main part thereof, and FIG. 3 is an enlarged tilted view of a light separating means.

1 to 3, reference numeral 1 denotes a dot matrix type liquid crystal display panel.
Does not have a color filter. This liquid crystal display panel is, for example, of a simple matrix type, in which a large number of transparent scanning electrodes are formed in parallel with each other on the inner surface of one of a pair of transparent substrates which face each other across the liquid crystal and the other transparent substrate. A large number of transparent signal electrodes are formed parallel to each other on the inner surface of the substrate so as to be orthogonal to the scanning electrodes.

Reference numeral 2 denotes a white light source lamp 3 for illuminating the liquid crystal display panel 1, and a white light A emitted from the light source lamp 2.
Is reflected by the reflector 3 and further collimated by the light flux correction lens (concave lens) 4 toward the liquid crystal display panel 1.

On the other hand, reference numeral 5 divides the white light A reflected by the reflector 3 and collimated by the light flux correction lens (concave lens) 4 into a large number of parallel striped light fluxes (light fluxes having an elongated rectangular section) a, a. The light beam splitting lens system 5 includes a light beam splitting lens array 6 and a light beam correction lens array 7 that makes the respective striped light beams a, a split by the light beam splitting lens array 6, parallel light beams. It consists of

As shown in FIG. 3, the light beam splitting lens array 6 is formed by arraying a large number of elongated convex lenses 6a, 6a in parallel, and the entire surface of the light beam splitting lens array 6 from the light source lamp 3 is formed. The white light A, which is uniformly incident on the convex lenses 6a, 6a, passes through the convex lenses 6a, 6a, and is condensed by the convex lenses 6a, 6a.
A large number of striped luminous fluxes a, a are condensed in front of 6a.
Is divided into

As shown in FIG. 3, the light flux correction lens array 7 is formed by arranging a large number of elongated concave lenses 7a, 7a arranged in parallel and arranged. Striped luminous flux a, a
Are the concave lenses 7a, 7a of the light flux correction lens array 7.
After passing through a, the light beams are corrected by the concave lenses 7a, 7a into parallel light beams. The number of convex lenses of the light beam splitting lens array 6 and the number of concave lenses of the light beam correction lens array 7 are each 1/3 of the number of signal electrodes of the liquid crystal display panel 1.
Further, the light beam splitting lens array 6 and the light beam correcting lens array 7 are arranged such that the lengthwise direction of each lens 6a, 7a is parallel to the lengthwise direction of the signal electrode of the liquid crystal display panel 1. It is arranged.

Further, 8 is a prism array provided as a light separating means for separating the light from the light source into a plurality of types of light fluxes having different wavelength ranges, and the light flux correction lens array 7 converts the light fluxes into parallel light fluxes. Each stripe-shaped luminous flux a,
The prism array 8 divides a into three stripes of light in the red region, light in the green region, and light in the blue region.

That is, the prism array 8 forms a plurality of stripe light beams a, a, which are parallel light beams by the light beam correction lens array 7, in a different wavelength range and in different directions for different wavelength ranges. The prism array 8 is divided into R, G, and B, and as shown in FIG. 3, the prism array 8 is as long and thin as the number of concave lenses of the light flux correction lens array 7 (1/3 of the number of signal electrodes of the liquid crystal display panel 1). The optical prisms 8a, 8a are arranged in parallel so as to correspond to the respective striped light beams a, a. In addition,
The prism array 8 is also arranged such that the length directions of the respective prisms 8a, 8a are parallel to the length direction of the signal electrodes of the liquid crystal display panel 1.

Each prism 8a of this prism array 8,
8a, like a general prism, spectrally disperses the transmitted light by the light dispersion effect.
Striped luminous fluxes a and a that have been spectrally dispersed through a and 8a are roughly classified into light in the red wavelength range (hereinafter referred to as red light) R and light in the green wavelength range (hereinafter referred to as green light) G.
And blue light (hereinafter, referred to as blue light) B in the three wavelength bands. Since the red light R, the green light G, and the blue light B are obtained by spectrally dispersing white light, the striped lights R, G, B of the three colors are obtained.
If mixed as it is, white light will be obtained.

Reference numeral 9 denotes stripe-shaped light beams (light beams including red, green and blue stripe lights R, G and B) a and a which are spectrally transmitted through the respective prisms 8a and 8a of the prism array 8. The light flux correction lens array 9 corrects the light fluxes into parallel light fluxes. It is provided at the position just before touching.

The luminous flux correction lens array 9 has the same number of elongated cylindrical lenses 9 as the prism number of the prism array 8 (1/3 of the number of signal electrodes of the liquid crystal display panel 1).
a and 9a are arranged in parallel so as to correspond to the respective striped luminous fluxes a and a spectrally dispersed, and the luminous flux correction lens array 9 is also configured such that the longitudinal direction of each cylindrical lens 9a and 9a is The liquid crystal display panel 1 is arranged so as to be parallel to the length direction of the signal electrodes.

The respective cylindrical lenses 9a, 9a of this light flux correction lens array 9 correct the respective striped light fluxes a, a spectrally dispersed by the respective prisms 8a, 8a of the prism array 8 into parallel light, and obtain the respective stripe shapes. The red light R, the green light G, and the blue light B of the light fluxes a and a are made incident on the liquid crystal display panel 1 toward the pixel display portions of the respective columns of the liquid crystal display panel 1, respectively.

That is, the luminous flux incident on the liquid crystal display panel 1 is a large number of luminous fluxes in which red, green and blue stripes R, G and B are alternately arranged.
It has a large number of areas where the red, green and blue luminous fluxes R, G and B respectively enter, that is, a pixel display portion.

Then, stripe-shaped red light R, green light G, and blue light B are alternately arranged in the pixel display section of each column of the liquid crystal display panel 1 along the column direction, that is, the length direction of the signal electrode. When we put in a line of light, these red, green,
Since the blue lights R, G, B pass through and exit the liquid crystal display panel 1, the display image on the liquid crystal display panel 1 becomes a color image.

Further, in FIGS. 1 and 2, reference numeral 10 denotes a projection lens for enlarging and projecting the light transmitted through the liquid crystal display panel 1, that is, the color image light B displayed by the liquid crystal display panel 1, onto the screen 12 surface.

In this color liquid crystal projector, the white light A from the white light source lamp 2 is split into a large number of striped light fluxes a, a by a light flux splitting lens system 5, and the light is split by a light splitting means consisting of a prism array 8. , Different wavelength bands and facing different directions for each wavelength band, red, green,
A large number of blue light fluxes (stripe lights) R, G, B are separated, and the large number of red, green, and blue light fluxes R, G, B are respectively reflected by a light flux correction lens array 9 in a single liquid crystal display panel 1. The light emitted from the liquid crystal display panel 1, which is incident on a predetermined area (each pixel display section), that is, color image light is enlarged and projected by the projection lens 10 and displayed on the screen 11.

According to this color liquid crystal projector, the light from the light source lamp 2 is separated by the light separating means, and a plurality of kinds of light fluxes having different wavelength ranges, that is, red, green and blue light fluxes R,
G and B are obtained, and the light fluxes R, G, and B of the respective colors are made incident on different regions (pixel display portions) of the liquid crystal display panel 1, respectively. Therefore, a color filter for coloring the liquid crystal display panel 1 Therefore, it is possible to increase the light transmittance of the liquid crystal display panel 1 since there is no large loss of light energy due to absorption of light of a specific wavelength as in the case of coloring with a color filter. Also, most of the light from the light source lamp 2 becomes the red, green, and blue luminous fluxes R, G, B, and the liquid crystal display panel 1
Since the light is incident on, the light from the light source lamp 2 can be used without waste.

Therefore, according to the color liquid crystal projector, it is possible to reduce the loss of light energy and project a color image of sufficient brightness on the screen 11 without increasing the light emission energy of the light source lamp 2. Further, since it is not necessary to increase the light emission energy of the light source lamp 2, the heat generation of the liquid crystal display panel can be suppressed to a low level, so that the heat countermeasure for preventing the temperature rise of the liquid crystal display panel becomes simple.

In the above embodiment, the prism array 8
The red, green, and blue lights R, G, and B, which are spectrally dispersed by the light flux correction lens array 9 and are corrected into parallel light fluxes, are directly incident on the liquid crystal display panel 1.
The red, green, and blue lights R, G, and B may be changed in direction by a reflection plate so as to be incident on the liquid crystal display panel 1. By doing so, the liquid crystal display panel 1 and the projection lens 10 can be made. It is possible to project a color image on a screen provided in any direction by arbitrarily selecting the direction.

In the above embodiment, the light from the light source is divided into a large number of striped light beams a, a by the light beam splitting lens system 5.
Although the light from the light source is incident on the light separating means (prism array) 8 as it is, the light from the light source may be directly incident on the light separating means. It is not limited to the above-mentioned embodiment as long as it separates into a plurality of kinds of light fluxes that are different and face different directions for each wavelength range, and further, different directions for each wavelength range separated by the light separating means. The luminous flux correction means for making a plurality of types of luminous fluxes directed to the respective beams incident on predetermined regions of the liquid crystal display panel 1 are not limited to the above-described luminous flux correction lens array 9.

Further, in the above embodiment, the lights R, G, B in the respective wavelength bands obtained by separating the light from the light source are directed to the pixel display section of each column of the liquid crystal display panel 1, that is, each signal electrode. Although the light is made incident, the light R, G, B in each wavelength range
May be directed toward the pixel display section of each row of the liquid crystal display panel 1, that is, each scanning electrode.

The present invention is not limited to a projector that projects and displays the light emitted from the liquid crystal display panel 1 on the screen 11, but a non-projection type color liquid crystal display in which the light emitted from the liquid crystal display panel 1 is viewed as a display image. Can also be applied to.

[0036]

According to the color liquid crystal display device of the present invention, the light from the light source is separated into a plurality of kinds of light fluxes having different wavelength ranges by the light separating means, and the plurality of kinds of light fluxes are incident on a single liquid crystal display panel. Since the color image is displayed on this liquid crystal display panel, the loss of light energy can be reduced and a color image with sufficient brightness can be projected on the screen surface without increasing the light emission energy of the light source. Moreover, since it is not necessary to increase the light emission energy of the light source, heat generation of the liquid crystal display panel can be suppressed to a low level.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an embodiment in which the present invention is applied to a color liquid crystal projector.

FIG. 2 is an enlarged view of a main part thereof.

FIG. 3 is an enlarged perspective view of a light separating unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display panel 2 ... Light source lamp 5 ... Light flux splitting lens system 8 ... Prism array (light separating means) 9 ... Light flux correction lens array A ... White light a ... Striped light flux R ... Red light (light in red wavelength range) ) G ... Green light (light in the green wavelength range) B ... Blue light (light in the blue wavelength range) Z ... Color image light

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display area H04N 9/31 C B

Claims (2)

[Claims] 1. A light source, a light separating means for separating light from the light source into a plurality of kinds of light fluxes having different wavelength ranges, and the plurality of kinds of light fluxes separated by the light separating means are incident on different regions. A color liquid crystal display device comprising a single liquid crystal display panel. 2. The light flux entering the liquid crystal display panel is a large number of light fluxes in which a plurality of types of light fluxes having different wavelength regions are alternately arranged, and the liquid crystal display panel includes a large number of light fluxes into which the plurality of light fluxes are respectively incident. The color liquid crystal display device according to claim 1, having a region.