JP2883430B2 - Liquid crystal display - Google Patents

Description

The present invention relates to a liquid crystal display device, particularly to a liquid crystal projector having a liquid crystal panel as an original image.

(B) Conventional technology In recent years, as a device that can easily obtain a large image display,
Liquid crystal projectors using liquid crystal panels have begun to spread. Currently, most liquid crystal panels used in such liquid crystal projectors are of an active matrix type having good display characteristics such as contrast and response.

However, in the case of an active matrix type liquid crystal display panel, since one active element, for example, a TFT (thin film transistor) or a non-linear element having a MIM structure is formed for one pixel, the aperture ratio of the effective pixel tends to be small. .

Therefore, when a liquid crystal projector is configured using such a liquid crystal panel, the effective pixel aperture ratio is small, so that the light use efficiency is low, and sufficient luminance is not obtained in a display image obtained on a screen. was there.

It is considered that this disadvantage can be solved to some extent by using a high-brightness light source for the liquid crystal projector. In this case, however, an increase in power consumption of the entire apparatus or high heat generation due to the use of a high-brightness light source is active. There is a concern that the operating characteristics of the active element of the matrix type liquid crystal display panel may be affected.

On the other hand, in a normal liquid crystal display panel as shown in FIG. 4, the preferred viewing angle direction (high-contrast axis direction) indicated by an arrow is set at an angle (eg, about 6 degrees) inclined from the vertical direction of the panel P. Exists. In FIG. 1, reference numeral 1 denotes a transparent pixel electrode substrate, 2 denotes a transparent counter electrode substrate, and 3 denotes a sealant that seals the periphery of both substrates, and a liquid crystal 4 is placed in a cell constituted by these. It is enclosed.
In the liquid crystal 4, pixel separation is performed at a portion (hatched position) 40 which is shielded from light by a light shielding mask provided on the counter electrode substrate.

When a projector is configured using a liquid crystal panel having such a high contrast axis direction, as shown in the schematic configuration diagram of FIG. Since the viewing angles are aligned, this panel is mounted diagonally. That is,
Parallel rays from the light source lens R1 for converting light from the light source L into parallel rays are efficiently transmitted along the preferential viewing angle direction of the obliquely provided panel P, and the transmitted light is screened through the magnifying projection lens R2. Projected onto S.

In such a projector, the liquid crystal panel P must be arranged at an angle, which not only has a drawback of complicating the device structure, but also makes it difficult to adjust the angle of inclination of the panel P. .

(C) Problems to be Solved by the Invention The present invention has been made in view of the above-mentioned drawbacks, and has been made to improve the light use efficiency in order to eliminate the drawback that sufficient luminance cannot be obtained in a display image. The present invention provides a liquid crystal display device capable of obtaining a brighter screen.

In addition, the present invention, apparently high contrast axis direction,
An object of the present invention is to provide a liquid crystal display device that can be set in a direction perpendicular to a liquid crystal panel.

(D) Means for Solving the Problems In the liquid crystal display device of the present invention, a convex lens having an area larger than the area of each pixel is provided on at least one surface of each pixel of the light transmission type liquid crystal panel, and light from a light source is provided by the convex lens. The main point is that the convex lens is formed into an aspherical asymmetric cross-sectional shape so as to provide a focal point in a direction along a high contrast direction axis of the liquid crystal panel while condensing the light and supplying it to each pixel of the liquid crystal panel.

Further, the liquid crystal display device of the present invention is provided with a convex lens having an area larger than the area of each pixel on at least one surface of each pixel of the light transmission type liquid crystal panel, and condensing light from the light source by the convex lens to form the liquid crystal panel. A light-blocking mask for blocking light leakage from a region other than the pixels, the light-curing resin being applied to the entire surface of the liquid crystal panel. The gist of the present invention is that the pattern is exposed and patterned by light transmitted through the liquid crystal panel itself.

(E) Function According to the liquid crystal display device of the present invention, since the light from the light source is condensed by the convex lens and supplied to each pixel of the liquid crystal panel, the light use efficiency is greatly increased.

Further, according to the liquid crystal display device of the present invention, a pair of aspherical asymmetrical condensing convex lenses can be arranged before and after the liquid crystal panel for each pixel. By this lens shape, the incident light is refracted along the high contrast axis direction of the liquid crystal panel, and the light emitted from this panel is refracted again and transmitted as light in the same direction as the incident light, that is, parallel light. Become.

Further, according to the liquid crystal display device of the present invention, the inter-pixel light-shielding mask originally provided in the liquid crystal panel can be used for the formation of the lens in order to improve the display contrast. That is,
By exposing and patterning the photocurable resin applied to the liquid crystal panel with light transmitted through the liquid crystal panel with the inter-pixel light-shielding mask, a convex lens having an aspherical asymmetric cross-sectional shape can be obtained.

(F) Embodiment FIG. 1 is a sectional view of a liquid crystal panel of the liquid crystal display device of the present invention. In the figure, 1 is a transparent pixel electrode substrate, 2 is a transparent counter electrode substrate, 3 is a sealant that seals the periphery of both these substrates, 4 is a liquid crystal, and 40 is provided on the counter electrode substrate 2. The portions (hatched positions in the figure) shielded by the light-shielding mask are shown, and these may be the same as those in the conventional device in FIG.

4 is different from the conventional device of FIG. 4 in that convex surfaces 5, 5... Having an area larger than the area of each pixel are provided on both surfaces of the liquid crystal panel P. , 5 ... collect the light from the light source and supply it to each pixel.

Moreover, since the convex lenses 5, 5,... Are formed to have an aspherical asymmetric cross-sectional shape so as to provide a focal point in a direction along the high contrast direction axis of the liquid crystal panel, light incident perpendicularly to the panel P is obtained. Are condensed and refracted in the direction of the high contrast axis, and the light emitted from the panel P is condensed by the convex lenses 5, 5,.

Therefore, when such a liquid crystal panel P is employed in a projector, as shown in the schematic configuration diagram of FIG.
By simply arranging the transmitted light axis perpendicular to the transmitted light axis, the transmitted light axis and the apparent high contrast axis direction can be matched. That is, parallel light rays from the light source lens R1 for converting light from the light source L into parallel light rays are efficiently transmitted along the apparent high contrast axis direction of the vertically arranged panel P, and this transmitted light is enlarged by a magnifying projection lens. It is projected on the screen S via R2.

Thus, in a liquid crystal panel using an active switching element such as a TFT or MIM, the aperture ratio of the pixel is reduced due to the size and wiring of the element, and thus the light transmittance is also reduced, but in the liquid crystal display device of the present invention, Are disposed on the pixel surface without wasting light applied to the opening of the pixel, that is, the portion other than the effective display portion.
, And the light passes through the pixel opening along the high contrast axis direction of the liquid crystal, and after passing through the panel, can be further converted into parallel light by the lenses 5, 5,..., And the light use efficiency is greatly improved. You.

Next, an example of a method of manufacturing the above-described lenses 5, 5,... Will be outlined based on FIGS.

First, as shown in FIG. 3 (a), in a state where a polarizing plate (not shown) is adhered to one surface of the liquid crystal panel P, an ultraviolet curing resin is applied on the polarizing plate, and Light irradiation is performed from the opposite side. The light thus irradiated is transmitted only in the pixel region by a light shielding mask for shielding light leakage from a region other than the pixel, and the transmitted light has high contrast in the panel P as indicated by an arrow in the drawing. The light is refracted in the axial direction and is incident on the ultraviolet-curable resin layer, which is cured.

The light irradiation at this time is performed at an angle mainly perpendicular to the panel P from the opposite surface of the panel P. In order to obtain an aspherical asymmetric cross-sectional shape larger than the pixel area,
The panel P is irradiated with light supplementarily from an angle slightly shifted from the vertical direction.

Thus, an array of lenses 5, 5,... On one surface of the liquid crystal panel P can be manufactured as shown in FIG.

Further, when a lens array is formed on the other side of the liquid crystal panel P, the first lens array shown in FIG. 2B is peeled off together with the polarizing plate (not shown) attached to the surface of the panel P. Then, in a state where the second polarizing plate is adhered to the other surface, a UV-curable resin is applied on this polarizing plate, and the same exposure and patterning as described above is performed to form a second lens array. I do. Then, the first lens array may be attached again to one surface of the panel P.

(G) Effects of the Invention Since the liquid crystal display device of the present invention has a structure in which light from a light source is condensed by a convex lens for each pixel and supplied to each pixel of the liquid crystal panel, light use efficiency is increased, and display is performed. The brightness of the image can be increased.

Further, according to the liquid crystal display device of the present invention, a pair of aspherical asymmetric condensing convex lenses can be disposed in front of and behind the liquid crystal panel for each pixel, so that incident light is directed along the high contrast axis direction of the liquid crystal panel. The light emitted from the panel is refracted again and transmitted as light in the same direction as the incident light, that is, parallel light, and the configuration of the projector using the light can be simplified and downsized. .

Further, since the inter-pixel light-shielding mask originally provided in the liquid crystal panel for improving the display contrast can be used for forming the lens, the liquid crystal display device of the present invention can be realized by a simple manufacturing method.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a liquid crystal panel used in the liquid crystal display device of the present invention, FIG. 2 is a conceptual configuration diagram of a projector equipped with the liquid crystal display device of the present invention, and FIG. FIG. 4 is a cross-sectional view of a conventional liquid crystal panel, and FIG. 5 is a conceptual configuration diagram of a conventional projector. 4 ... liquid crystal, 5 ... lens, 50 ... ultraviolet curable resin layer,
P ... LCD panel.

Claims (2)

(57) [Claims] 1. A convex lens having an area larger than the area of each pixel is provided on at least one surface of each pixel of the light transmission type liquid crystal panel, and light from a light source is condensed by the convex lens and supplied to each pixel of the liquid crystal panel. A liquid crystal display device, wherein the convex lens has an aspherical asymmetric cross-sectional shape so as to provide a focal point in a direction along a high contrast direction axis of the liquid crystal panel. 2. A light transmission type liquid crystal panel, wherein at least one surface of each pixel is provided with a convex lens having an area larger than the area of each pixel, and the convex lens collects light from a light source and supplies the light to each pixel of the liquid crystal panel. Wherein the liquid crystal panel is provided with a light-shielding mask for shielding light leakage from a region other than the pixel, and the convex lens is provided on the liquid crystal panel with respect to a photocurable resin applied to the entire surface of the liquid crystal panel. A liquid crystal display device characterized by being exposed and patterned by light transmitted through itself.