JPH0743700A - Liquid crystal display element - Google Patents

Abstract

PURPOSE:To provide the liquid crystal display element with which display images of high brightness are easily obtd. CONSTITUTION:The parts corresponding to the non-apertures on the incident light side of a transmission type liquid crystal display panel are provided with reflection layers 11. The parts corresponding to the peripheral parts of the respective microlens of the transmission type liquid crystal display panel provided with a microlens array for improving an equiv. opening rate are provided with the reflection layers 11. The incident light not used for displaying images is reflected by the reflection layers 11 described above, by which the rise of the temp. of the liquid crystal of the liquid crystal display element is prevented and, therefore, the rise of the temp. of the liquid crystal of the liquid crystal display element is prevented even if the light from a light source of a large light quantity is made incident thereon. The displayed images of high brightness are thus easily obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmissive liquid crystal display panel and a micro-display for improving the equivalent aperture ratio.
The present invention relates to a liquid crystal display device such as a transmissive liquid crystal display panel provided with a lens array.

[0002]

2. Description of the Related Art A transmissive liquid crystal display panel, which is known as a kind of light valve constructed by using liquid crystal as a light modulating material, and a micro-panel for improving the equivalent aperture ratio.
It is well known that a liquid crystal display device such as a transmission type liquid crystal display panel provided with a lens array has been proposed in many configurations.
By the way, in a transmissive liquid crystal display element in which a large number of pixels are two-dimensionally arranged, a component (for example, a thin film transistor) for individually controlling the amount of transmitted light for each pixel cannot transmit light. A light-shielding area (black matrix
Black stripes, etc.) are provided, and the signal electrode busbars, the scanning electrode busbars, etc. are also non-transmissive portions of light.

Therefore, of the light incident on the transmissive liquid crystal display element in which a large number of pixels are two-dimensionally arranged, the light used for displaying an image becomes a part of the incident light. The pixel aperture ratio, which indicates the ratio of the amount of light incident on one pixel region to the amount of light output from one pixel in the state of 100% white, is
With the total area of the liquid crystal display device being constant, as the number of pixels is increased, the pixel size will naturally decrease.
In order to display a high-definition display image by increasing the number of pixels with high brightness, it is necessary to apply a large amount of incident light to the liquid crystal display element. However, since the liquid crystal used in the liquid crystal display device is not a lyotropic liquid crystal whose liquid crystal phase appears due to the effect of a solvent, but a thermotropic liquid crystal whose liquid crystal phase appears in a specific temperature range,
Since a change in temperature of the liquid crystal display element causes a phase transition among the crystal, the liquid crystal, and the liquid, the operating temperature of the liquid crystal display element must be kept within a predetermined temperature range even by irradiation with incident light.

[0004]

By the way, since the liquid crystal display element does not have a pixel aperture ratio of 100%, the incident light which is not used for displaying an image raises the temperature of the liquid crystal display element. become. Therefore, it is not possible to simply use a high-output light source to obtain a high-luminance display image. Therefore, conventionally, as a means for obtaining a high-luminance display image, a transmissive liquid crystal display panel provided with a micro lens array for improving the equivalent aperture ratio of a liquid crystal display element has been proposed. When using the above-mentioned micro lens array, theoretically 100
Although it is possible to obtain a pixel aperture ratio of%, it is actually several tens of%.
Therefore, it was not possible to easily obtain a high-luminance display image even with a transmissive liquid crystal display panel provided with a conventional micro lens array.

[0005]

The present invention provides a liquid crystal display device having a reflection surface for incident light at a portion corresponding to a non-aperture portion on the incident light side of a transmissive liquid crystal display panel, and an equivalent aperture ratio. Micro to improve
Provided is a liquid crystal display device having a reflection surface for incident light at a portion corresponding to the peripheral portion of each micro lens in a transmission type liquid crystal display panel provided with a lens array.

[0006]

[Function] A micro-surface for reflecting incident light not used for displaying an image or improving the equivalent aperture ratio by a reflecting surface provided at a portion corresponding to the non-aperture portion on the incident light side of the transmissive liquid crystal display panel. By reflecting the incident light that is not used for displaying an image by the reflecting surface for the incident light, which is provided in the portion corresponding to the peripheral portion of each micro lens in the transmissive liquid crystal display panel provided with the lens array, Even when light is incident from a light source having a light amount, it is possible to prevent the temperature of the liquid crystal in the liquid crystal display element from rising, so that it is possible to easily obtain a display image with high brightness.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The concrete contents of the liquid crystal display device of the present invention will be described in detail below with reference to the accompanying drawings. 1 to 5 are enlarged vertical cross-sectional views of a part of different embodiments of the liquid crystal display device of the present invention, and FIG. 6 is a vertical cross-sectional view for explaining a configuration example of a reflective layer. 1 to 3 show a configuration example of a liquid crystal display device when the present invention is embodied as a thin film transistor (TFT) / switch matrix laminated / transmissive liquid crystal display panel, and FIGS. 4 and 5 show thin film transistors. (TFT) -Switch matrix lamination-When the present invention is carried out in a configuration mode in which a micro lens array is added to a transmissive liquid crystal display panel in order to improve the equivalent aperture ratio of the transmissive liquid crystal display panel. 2 shows an example of the configuration of the liquid crystal display element.

1 to 5, 1 and 13 are substrates (eg, glass substrates) made of a transparent material, and 2 are pixel electrodes (pixel electrodes) made of a transparent conductive film such as an ITO film, 3 Is a silicon dioxide film (SiO2
Film), 4 is a gate electrode made of a conductive material such as chromium, 5, 7 is a silicon nitride film (SiNx film), 6 is an amorphous silicon film (a-Si film), 8 is a source electrode, 9
Is a drain electrode, 10 is a liquid crystal layer, 11 is a reflective layer, 12 is a counter electrode made of a transparent conductive film such as an ITO film, TFT is a thin film transistor, P is incident light, and 14 is a black stripe in FIG. In FIG. 3, 15 is a transparent conductive film, 16 and 17 are alignment films, 18 is a black matrix, 19 is a color separation filter, and in FIGS. 4 and 5, 18 is a black matrix, 20 is an optical adhesive layer, and 21 is a plane. It is a micro lens array.

By the way, in the liquid crystal display device of the present invention illustrated in FIGS. 1 to 3, the components other than the reflective layer 11 are known as thin film transistors (TFTs), switch matrix stacks, and transmissive liquid crystal display panels. The structure of the liquid crystal display device of the present invention illustrated in FIGS. 4 and 5 is the same as that of the conventional liquid crystal display device described above, except that the reflective layer 11 is a thin film transistor (TFT) switch. Similar to a conventional liquid crystal display element known as a configuration mode in which a micro lens array is added to a transmissive liquid crystal display panel in order to improve the equivalent aperture ratio of a matrix laminated transmissive liquid crystal display panel. Therefore, detailed description of the above-mentioned conventional configuration will be omitted.

In the liquid crystal display device of the present invention comprising the transmissive liquid crystal display panel shown in FIGS. 1 to 3, a reflecting surface 11 for incident light P provided in a portion corresponding to the non-opening portion on the incident light side thereof. And a peripheral portion of each micro lens in the liquid crystal display element of the present invention shown in FIGS. 4 and 5, that is, a transmissive liquid crystal display panel provided with a micro lens array for improving the equivalent aperture ratio. The reflective layer 11 in the liquid crystal display element in which the reflective layer 11 that functions as a reflective surface for the incident light P is formed in the portion corresponding to A reflective layer made of a single metal (eg, gold, silver, aluminum, etc.) film, or having a reflectance higher than that of the single metal film itself. Layer film structure and the reflective layer, or a high refractive index dielectric (e.g., TiO2, CeO2) and thin,
Use a dielectric mirror composed of a dielectric multi-layered film formed by alternately laminating thin films of low refractive index dielectrics (eg, SiO2, MgF2), or white fine powder such as titanium white, magnesium fluoride, etc. It is possible to use a reflective layer having any constitution such as a reflective layer formed by a printing method.

FIG. 6 shows an example of the structure of the above-mentioned reflective layer 11 by taking the reflective layer 11 having a multi-layered film structure capable of obtaining a reflectivity higher than that of a single metal film itself. 6 (a), 22 is a glass substrate having a refractive index of 1.5, 23 is an aluminum film having a film thickness of 48 nm (optical thickness of 27.2 nm) (having a refractive index of about 0.57). ), 24 is a magnesium fluoride film having a film thickness of 86.9 nm (optical thickness of 120 nm) (having a refractive index of approximately 1.
38) and 25 have a film thickness of 48.8 nm (optical thickness of 12
0 nm) cerium oxide film (refractive index is approximately 2.46), and 22 in FIG. 6B has a refractive index of 1.5.
Glass substrate, 26 is a silver film with a thickness of 90 nm (optical thickness is 7.34 nm) (refractive index is approximately 0.08), and 27 is a thickness of 70.4 nm (optical thickness is 97.5 nm). Is a magnesium fluoride film (having a refractive index of approximately 1.38) and 28 is a cerium oxide film (having a refractive index of approximately 2.59) having a film thickness of 37.7 nm (optical thickness is 97.5 nm).

A reflection surface 11 for incident light provided in a portion corresponding to the non-opening portion on the incident light side in the liquid crystal display device of the present invention by the transmission type liquid crystal display panel illustrated in FIGS. 1 to 3, and FIG. 4 and 5 correspond to the peripheral portion of each micro lens in the liquid crystal display element of the present invention, that is, in the transmissive liquid crystal display panel provided with the micro lens array for improving the equivalent aperture ratio. The reflection layer 11 that functions as a reflection surface for the incident light on the part effectively reflects the incident light, which is not used for displaying an image, of the light P supplied from the light source to the liquid crystal display element, and the reflected light is the liquid crystal layer 10. Therefore, even if light from a light source with a large amount of light is incident on the liquid crystal display element, the temperature rise of the liquid crystal in the liquid crystal display element can be prevented. The liquid crystal display device using a transmission type liquid crystal display panel capable of displaying the display image brightness according to the present invention can be easily provided wishes.

[0013]

As is apparent from the above detailed description, the liquid crystal display device of the present invention has a reflection surface for incident light in a portion corresponding to the non-opening portion on the incident light side of the transmissive liquid crystal display panel. , A transmissive liquid crystal display panel provided with a micro lens array for reflecting the incident light not used for displaying an image to prevent the temperature rise of the liquid crystal in the liquid crystal display element and improving the equivalent aperture ratio. The incident light not used for displaying an image can be reflected by the reflecting surface for incident light provided in the portion corresponding to the peripheral portion of each micro lens in, and the temperature rise of the liquid crystal in the liquid crystal display element can be prevented. Even when light from a light source is incident, the temperature of the liquid crystal in the liquid crystal display element can be prevented from rising, making it easy to display high-brightness images. And is possible to obtain, conventional problems described above, according to the present invention can be satisfactorily solved.

[Brief description of drawings]

FIG. 1 is an enlarged vertical sectional view of a part of a liquid crystal display element of the present invention.

FIG. 2 is an enlarged vertical sectional view of a part of the liquid crystal display element of the present invention.

FIG. 3 is an enlarged vertical sectional view of a part of the liquid crystal display element of the present invention.

FIG. 4 is an enlarged vertical sectional view of a part of the liquid crystal display element of the present invention.

FIG. 5 is an enlarged vertical sectional view of a part of the liquid crystal display element of the present invention.

FIG. 6 is a vertical cross-sectional view for explaining a configuration example of a reflective layer.

[Explanation of symbols]

1, 13 ... Substrate made of transparent material (eg glass substrate), 2 ... Pixel electrode (pixel electrode) made of transparent conductive film, 3 ... Silicon dioxide film (SiO2 film), 4 ...
Gate electrode made of conductive material, 5, 7 ... Silicon nitride film
(SiNx film), 6 ... Amorphous silicon film (a-Si
Film), 8 ... Source electrode, 9 ... Drain electrode, 10 ... Liquid crystal layer, 11 ... Reflective layer, 12 ... Counter electrode made of transparent conductive film such as ITO film, 14 ... Black stripe, 15 ... Transparent conductive film, 16, 17 ... Alignment film, 18 ... Black matrix, 19 ... Color separation filter, 20 ... Optical adhesive layer, 2
1 ... Planar micro lens array, 22 ... Glass substrate,
23 ... Magnesium fluoride film, 25 ... Cerium oxide film, 2
6 ... Silver film, 27 ... Magnesium fluoride film, 28 ... Cerium oxide film, TFT ... Thin film transistor, P ... Incident light,

Claims (2)

[Claims] 1. A liquid crystal display device comprising a transmissive liquid crystal display panel having a reflection surface for incident light at a portion corresponding to a non-opening portion on the incident light side. 2. A reflection surface for incident light is formed at a portion corresponding to a peripheral portion of each micro lens in a transmissive liquid crystal display panel provided with a micro lens array for improving an equivalent aperture ratio. Liquid crystal display device.