JPH07114011A - Direct viewing type liquid crystal display device - Google Patents

Abstract

PURPOSE:To suppress the rough feel of displayed images based on a light shielding layer by adhering a microlens substrate to a substrate on a light exit side. CONSTITUTION:A matrix array substrate 7 is adhered by an adhesive to the surface formed with microlenses of the microlens substrate 1. The surface of a counter substrate 5 consisting of glass, quartz, etc., is then provided with the light shielding layer 4, color filters 2 and a counter electrode 3. This substrate is stuck to the matrix array substrate 7 by disposing a prescribed gap therebetween. A liquid crystal compsn. 8 is held therebetween to constitute the liquid crystal display device. The resulted liquid crystal display device is used as a view finder for video cameras. The substrate on the light exit side is a direct viewing side of the device. The light transmitted through the aperture of the liquid crystal display device is eventually viewed by the condensing effect of the microlenses if the substrate side is provided with the microlens substrate. The rough feel of the display images based on the light shielding layer is therefore eliminated even with the small-sized direct viewing type liquid crystal display device of small pixel sizes and opening rates.

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, and more particularly to a direct view type liquid crystal display device capable of improving image quality.

[0002]

2. Description of the Related Art In recent years, liquid crystal display devices have been utilized as a viewfinder for a video camera or a display for virtual reality in addition to a display element such as a television or a graphic display, by taking advantage of features such as thinness, low power consumption, and color display. Attention has been paid. like this,
The viewfinder is required to have high definition in addition to color display, and it is necessary to reduce the pixel size. For example, a screen size of 0.7 inches diagonally
~ It is required to form 300,000 pixels. Therefore, it is more important to increase the aperture ratio of the pixel portion and downsize the display device.

In the direct-viewing type liquid crystal display device used for such a viewfinder, an active matrix type liquid crystal display device is mainly used. An active matrix type liquid crystal display device uses a thin film transistor (TFT) as a switching element which is one of semiconductor active elements,
A matrix array substrate having pixel electrodes connected thereto, further provided with scanning lines and signal lines, and a counter substrate having counter electrodes arranged facing it.
The main part of the liquid crystal composition is sandwiched between these substrates. Further, a light shielding layer is provided in order to secure the contrast ratio and suppress the light leak current of the TFT.

FIG. 3 is a sectional view of a conventional direct-view type liquid crystal display device.
Shown in. Counter electrode 3, color filter 2 and light shielding layer 4
And a matrix array substrate 7 having a pixel switch 6 composed of a TFT and a liquid crystal composition 8 sandwiched therebetween to form a liquid crystal display device.
The display image is directly viewed from the side of the emitted light.

[0005]

However, when looking into a viewfinder manufactured by the conventional direct-view type liquid crystal display device, there is a problem that the light-shielding layer becomes anxious and the displayed image looks rough. This phenomenon is somewhat unnoticeable on the wide-angle side, but particularly when the image is enlarged on the telephoto side.

There is also a problem that the smaller the screen size, the larger the number of pixels and the smaller the aperture ratio, the greater this tendency.

The present invention has been made in order to solve such a problem, and is a direct-view type which can suppress the roughness of a display image based on a light-shielding layer even with a small pixel size and small aperture ratio. An object is to provide a liquid crystal display device.

[0008]

A direct-view type liquid crystal display device of the present invention comprises a liquid crystal composition between a substrate on which an electrode is formed and a counter substrate which is arranged facing the substrate and on which a counter electrode is formed. In a direct-view type liquid crystal display device in which light is incident from the counter substrate side, is emitted to the substrate side, and is directly viewed on the emission side, a microlens substrate is bonded to the substrate on the light emission side. Characterize.

The microlens substrate according to the present invention is a selective ion exchange method for forming a microlens having a desired refractive index by diffusing and substituting desired ions in glass, a method for molding glass, etc., photolithography. It can be manufactured by a method of forming a lens using a technique. Among them, the selective ion exchange method is preferable because it can obtain a microlens substrate having a uniform thickness and a thin thickness.

The substrate on which the electrode according to the present invention is formed is
It may be either an active matrix array substrate having a two-dimensional pixel switch formed thereon or a simple matrix type substrate. In the present invention, an active matrix array substrate which is excellent in high-speed response and suitable for high definition is particularly preferable.

Such a matrix array substrate includes semiconductor active elements arranged in a matrix on a transparent substrate and pixel electrodes electrically connected to the semiconductor active elements. Here, the semiconductor active element refers to a switching transistor used for each pixel electrode, a drive circuit transistor for driving the pixel electrode, and the like. As the active layer, single crystal, polycrystal, or amorphous semiconductor can be used. Among these, single crystal silicon,
Polycrystalline silicon and amorphous silicon are preferable, and polycrystalline silicon is particularly preferable because signal lines and scanning lines can be easily formed on the same substrate and the size can be easily reduced. In the direct-view liquid crystal display device such as a viewfinder for a video camera or a display for virtual reality, an element technology that can be easily miniaturized is particularly important.

The microlens substrate and the matrix array substrate are adhered together using an adhesive. The adhesive is preferably translucent and excellent in heat resistance, and examples thereof include UV curing type and epoxy type.

In the direct-viewing type liquid crystal display device of the present invention, the light-shielding layer is arranged at a position for protecting the semiconductor active element, but the substrate to be arranged is not particularly limited. However, it is preferable to form the light-shielding layer on the matrix array substrate on which the TFTs are formed, because a high aperture ratio can be achieved by improving the alignment accuracy of the counter substrate. A metal such as chromium (Cr) can be used for the light shielding layer.

Further, in order to display the color of the direct view type liquid crystal display device of the present invention, a color filter may be arranged. In that case, the color filter can be formed on the opposite substrate or the surface of the matrix array substrate on which the liquid crystal is sealed as usual, or between the matrix array substrate on the light emitting side and the microlens substrate. You can also do it.

For the formation of the elements and wirings and the liquid crystal composition used in the direct-view type liquid crystal display device of the present invention, known means used for manufacturing a liquid crystal display device can be used.

In the direct-view type liquid crystal display device of the present invention, a matrix array substrate to which a microlens substrate is adhered and a counter substrate are arranged, and a liquid crystal composition is sandwiched between them to manufacture a liquid crystal display device. When the counter substrate is a translucent substrate, it is a transmissive liquid crystal display device, but the present invention is also applicable to a reflective liquid crystal display device.

[0017]

The substrate on the light emitting side is the direct view side in the direct view type liquid crystal display device of the present invention. When the microlens substrate is provided on the substrate side, the light that has passed through the opening of the liquid crystal display device is mainly seen due to the condensing action of the microlens.
For this reason, even in a small direct view type liquid crystal display device having a small pixel size and a small aperture ratio, the roughness of the display image based on the light shielding layer is eliminated.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The liquid crystal display device of the present invention will be described in detail below with reference to the drawings. Example 1 FIG. 1 is a sectional view of a liquid crystal display device of this example. First, the matrix array substrate 7 is manufactured by the method described below.

A polycrystalline silicon layer is formed on a translucent substrate such as glass or quartz, and the switching TFT 6 and the driving circuit TFT are formed and arranged by using this as an active layer, and an auxiliary capacitance electrode, a pixel electrode, and a signal electrode. Lines and scanning lines are formed and arranged on the same transparent substrate. The pixel pitch is 30 μ
m. Since polycrystalline silicon has high mobility, the size of the switching TFT can be reduced. Furthermore, since a high-quality insulating film obtained by a thermal oxidation method or the like can be used, a high aperture ratio can be obtained even with a small size.

Next, using the ion exchange method, the pitch is 3
A microlens substrate 1 having a thickness of 0 μm and a thickness of 1 mm is formed. The matrix array substrate 7 is adhered to the surface of the microlens substrate 1 on which the microlenses are formed with an adhesive.

A light shielding layer 4, a color filter 2 and a counter electrode 3 are provided on a counter substrate 5 made of glass, quartz or the like.
A predetermined space is provided between the matrix array substrate 7 and the matrix array substrate 7 and the liquid crystal composition 8 is sandwiched between them to form a liquid crystal display device. As a comparative example, the microlens substrate 1
A liquid crystal display device which is the same as that of the example 1 is manufactured except that is not used.

When the obtained liquid crystal display device was used for a viewfinder for a video camera, the displayed image did not have a rough feeling as compared with the comparative example.

Embodiment 2 FIG. 2 is a sectional view of a liquid crystal display device of this embodiment. The matrix array substrate 7 is manufactured by the same method as in the first embodiment. Next, after the interlayer insulating layer 9 is formed on the switching TFT 6 on the substrate 7, the switching TFT is formed.
The light-shielding layer 4 is formed at a position that covers 6.

The microlens substrate 1 is adhered to the matrix array substrate 7 on which the light shielding layer 4 is formed via the color filter layer 2 with an adhesive. The microlens substrate 1 is formed by the same method as in Example 1, and the surface on which the microlenses are formed is bonded to the matrix array substrate 7. The color filter layer 2 including the R, G, and B layers is thus formed into the microlens substrate 1 and the matrix array substrate 7.
By forming the gap between the transparent electrode and the transparent electrode, the problem of unevenness due to the color filter layer 2 and the peeling of the transparent electrode can be eliminated, and the manufacturing margin of the transparent electrode can be widened.

The counter electrode 3 is provided on the counter substrate 5 made of glass, quartz, or the like, and the matrix array substrate 7 is bonded to the matrix substrate 7 with a predetermined gap therebetween, and the liquid crystal composition 8 is sandwiched therebetween to form a liquid crystal display device. . In addition, as a comparative example, the same liquid crystal display device as in Example 2 is manufactured except that the microlens substrate 1 is not used.

When the obtained liquid crystal display device was used for a viewfinder for a video camera, the displayed image did not have a rough feeling as compared with the comparative example.

[0027]

In the direct-view type liquid crystal display device of the present invention, since the microlens substrate is bonded to the substrate on the light emitting side,
The light transmitted through the opening of the liquid crystal display device can be mainly seen. As a result, it is possible to suppress the roughness of the display image based on the light shielding layer of the direct-viewing type liquid crystal display device.

Further, in the direct-viewing type liquid crystal display device of color display, since the problem of unevenness due to the color filter and the peeling of the transparent electrode are eliminated, the manufacturing yield is further improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a cross-sectional structure of a direct-view type liquid crystal display device of Example 1.

FIG. 2 is a diagram showing a cross-sectional structure of a direct-view type liquid crystal display device of Example 2.

FIG. 3 is a diagram showing a cross-sectional structure of a conventional direct view type liquid crystal display device.

[Explanation of symbols] 1 ... Microlens substrate, 2 ... Color filter layer,
3 ... Counter electrode, 4 ... Light-shielding layer, 5 ... Counter substrate, 6 ...
... TFT for switching, 7 ... matrix array substrate, 8 ... liquid crystal composition, 9 ... interlayer insulating layer.

Claims (1)

[Claims] 1. A liquid crystal display device in which a liquid crystal composition is sandwiched between a substrate on which an electrode is formed and an opposite substrate which is arranged facing the substrate and on which an opposite electrode is formed, In the direct-view liquid crystal display device, which is incident from the counter substrate side, is emitted to the substrate side, and is directly viewed on the emission side, a microlens substrate is bonded to the substrate on the light emission side. Type liquid crystal display device.