JPH01108524A - Parallel a/d converter for liquid crystal light - Google Patents

Abstract

PURPOSE:To cope with both positive and negative image conversions by a simple structure by forming the title converter by a structure in which a liquid crystal which can be operated by a voltage variation is enclosed in a gap of a liquid crystal oriented film, and thereafter, it is inserted and held by two polarizing elements whose polarization directions have been shifted to a suitable angle to each other. CONSTITUTION:The forming surfaces of liquid crystal oriented films 6, 6 of each liquid crystal substrate A, B are opposed by the inside to each other, a liquid crystal 7 which can be operated by a voltage variation is enclosed into its gap, and thereafter, structured so as to be inserted and held by two polarizing elements 8, 8 whose polarization directions have been shifted at a suitable angle to each other. Accordingly, a transparent electrode matrix can be brought to optical parallel A/D conversion without forming a thin film transistor (TFT) or a matrix electrode. In such a way, it is possible to cope with both positive and negative image conversions by a simple structure.

Description

[Detailed Description of the Invention] [Industrial Application Field] The liquid crystal optical parallel A/D converter according to the present invention is used in the optical information processing industry, particularly in the optical image information processing industry, and converts an analog input image into an optical form. This is particularly important when producing devices that must convert the original image into a digital image.

[Summary of the invention]

The liquid crystal optical parallel A/D converter according to the present invention includes forming a transparent conductive film on a transparent substrate, forming a photoconductive film thereon, forming an insulating film in the shape of a mesh lattice, and forming a liquid crystal alignment film thereon. When the liquid crystal substrate is A, and the liquid crystal substrate in which a transparent conductive film is formed on a transparent substrate and a liquid crystal alignment film is formed thereon is B,
After facing each other with the forming surfaces of the liquid crystal alignment films A and B facing each other, and filling the gap with a liquid crystal that can be operated by voltage changes, the two polarization directions are shifted at an appropriate angle from each other.
By using a structure sandwiched between two polarizing elements, it is possible to convert an analog input image into a digital negative or positive image while maintaining its optical form. Note that when performing image conversion, it is performed with a voltage applied between the opposing conductive films, and when returning to the initial state that does not include image information, the image information is included while being grounded or a reverse voltage is applied between the opposing conductive films. It is returned by irradiating with uniform light.

[Conventional technology]

Conventional liquid crystal optical parallel A/D converters have a structure in which transparent electrode matrices are individually driven by thin film transistors (TPTs), or electrode matrix nodes are driven in which a photoconductive film is provided between transparent electrodes and TPTs. There were many things that were.

[Problem that the invention seeks to solve]

However, the conventional liquid crystal optical parallel A/D converter has a problem in that the structure is complicated because the individual electrodes are driven by TPT as described above, and the manufacturing yield is therefore poor.

[Means for solving problems]

The liquid crystal optical parallel A/D converter according to the present invention includes forming a transparent conductive film on a transparent substrate, forming a photoconductive film thereon, forming an insulating film in the shape of a mesh lattice, and forming a liquid crystal alignment film thereon. When the liquid crystal substrate is A, and the liquid crystal substrate in which a transparent conductive film is formed on a transparent substrate and a liquid crystal alignment film is formed thereon is B,
After facing each other with the forming surfaces of the liquid crystal alignment films A and B facing each other, and filling the gap with a liquid crystal that can be operated by voltage changes, the two polarization directions are shifted at an appropriate angle from each other.
By using a structure sandwiched between two polarizing elements, optical parallel A/
This enables D conversion and solves the above problems.

[Effect]

Liquid crystal substrates A and B of the liquid crystal optical parallel A/D converter according to the present invention
The liquid crystal light parallel A/
When the light enters the D converter, the photoconductive film in the area irradiated with the light forming the analog image becomes conductive in an analog manner, but the liquid crystal sealed in the gap between the liquid crystal substrates A and B due to the action of the insulating film forming the mesh lattice. Only the light-irradiated portions constituting the analog image are arranged in a mesh grid pattern, that is, digitally. If you want to convert another analog image, the transparent conductive films of each of liquid crystal substrates A and B are grounded, and the liquid crystal is irradiated with uniform light that does not contain image information and has a wavelength sufficiently short to make the photoconductive film conductive. After the arrangement is made uniform, conversion is performed according to the analog image conversion procedure described above.

〔Example〕

Embodiments of the liquid crystal optical parallel A/D converter according to the present invention will be described with reference to the drawings. FIG. 1 shows a liquid crystal light parallel A/
It is a perspective view showing the composition of one example of a D converter. 1st
In the figure, 1 is a liquid crystal substrate A, 2 is a liquid crystal substrate B, 3 is a transparent conductive film, 4 is a photoconductive film, 5 is a mesh lattice insulating film, 6 is a liquid crystal alignment film, 7 is a TN liquid crystal, and 8 is a polarizing plate. be. In this example, the liquid crystal substrates A and B are blue plate glass with a size of 251 m x 25 mm x 1 ml, both sides of which are optically polished, and the transparent conductive film 3 is made of ITO with a film thickness of about 160 m by vacuum evaporation.
The photoconductive film 4 is formed by applying Se to a thickness of approximately 6 cm using a vacuum evaporation method.
00 people formed. In addition, as a mesh lattice insulating film, a SiO
It was processed into a square lattice with a grid size of 2008 m x 200 μm. Further, as a liquid crystal alignment film 6, a TN liquid crystal 7 with a large contrast ratio is used as a liquid crystal that can be operated by voltage changes, and a polarizing plate 8 using a polymer polarizing film is used as a polarizing element. The polarization directions were arranged parallel to each other.

Next, the basic operation of the liquid crystal optical parallel A/D converter according to the present invention in the embodiment shown in FIG. 1 is shown in FIG. In FIG. 2, 9 is a liquid crystal optical parallel A/D converter according to the present invention;
11 is an input analog image, 11 is an output digital image, and 12 is a driving power source. First, while a bias voltage of about 6 volts is applied to the liquid crystal optical parallel A/D converter according to the present invention by the drive power supply 9, an analog image is formed with light at the wavelength at which the Se photoconductive film is sensitive (for example, argon laser light). When the liquid crystal light parallel A/D converter 9 according to the present invention is irradiated with the liquid crystal light parallel A/D converter 9 according to the present invention, a negative image with respect to the input analog image 10 is formed in the liquid crystal light parallel A/D converter according to the present invention. Next, when the liquid crystal optical parallel A/D converter 9 according to the present invention is irradiated with uniform light that does not contain image information and is made of light having a sufficiently long wavelength (for example, semiconductor laser light with an emission wavelength of 850 μm) compared to the wavelength at which the Se photoconductive film is sensitive. An output digital image 11 is obtained as a negative image of the input analog image 10, and the desired optical parallel A/D conversion becomes possible.

When it is desired to erase the negative image formed in the liquid crystal optical parallel A/D converter 11 according to the present invention, a bias voltage of -6 to 0 ports is applied to the liquid crystal optical parallel A/D converter according to the present invention using the drive power supply 9. The liquid crystal light parallel A/D converter according to the present invention may be irradiated with uniform light that does not contain image information and is generated at a wavelength to which the Se photoconductive film is sensitive (for example, argon laser light). So far, we have described the method of converting an input analog image into a negative digital image, but when converting an input analog image into a positive digital image, the first method is
The polarization directions of the polarizing plates 8 in the block diagram of the liquid crystal optical parallel A/D converter according to the present invention shown in the figure may be orthogonal to each other.

Furthermore, in this embodiment, a TN liquid crystal with a high contrast ratio was used as the liquid crystal 7, but if even higher speed driving is required, S
It is also possible to use mC liquid crystal or ferroelectric liquid crystal. Furthermore, as the photoconductive film 4, C
dS+ CdSe, Zn5e.

A chalcogenide compound such as HgCdTe or a photoconductive organic substance such as vanadyl phthalocyanine may be used.

When driving the liquid crystal optical parallel A/D converter according to the present invention, two near-infrared semiconductor lasers and an SHG element using a near-infrared semiconductor laser and a nonlinear optical crystal such as 8-BaJ03 are used as light sources. Approximately 2 m when using a TN liquid crystal by synchronizing the drive power to the external semiconductor laser and the drive power to the liquid crystal optical parallel A/D converter according to the present invention.
Approximately 200μ when using 5ecl frame and SmC liquid crystal
sec/frame, approximately 100μ when using ferroelectric liquid crystal
It has been found that conversion speeds of sec/frame can be obtained.

Further, the mesh lattice-shaped insulating film shown in FIG. 1 is not limited to a square lattice shape, and may be a hexagonal light grid (honeycomb shape) or a regular triangular light grid. Further, as the insulator material, it is also possible to use materials such as A7!203, Si+Na, and Ta205.

〔Effect of the invention〕

As described above, in the liquid crystal optical parallel A/D converter according to the present invention, a transparent conductive film is formed on an alliance substrate, a photoconductive film is formed on the transparent conductive film, a mesh lattice-shaped insulating film is formed on the transparent conductive film, and the liquid crystal When A is a liquid crystal substrate on which an alignment film is formed, and B is a liquid crystal substrate on which a transparent conductive film is formed on a transparent substrate and a liquid crystal alignment film is formed thereon, the surfaces on which the liquid crystal alignment films of A and B are formed are mutually They are placed inward facing each other, and a liquid crystal that can be operated by voltage changes is sealed in the gap between them, and then sandwiched between two polarizing elements whose polarization directions are shifted at an appropriate angle.The liquid crystal used for the Samurai is TN liquid crystal, SmC Liquid crystal, ferroelectric liquid crystal,
Since the photoconductive film used is a chalcogenide compound film or a photoconductive organic film, it has a simpler structure than conventional liquid crystal optical parallel A/D converters, and can support both positive and negative image conversion. Optical parallel A/D conversion becomes possible, which has a great effect on optical parallel image/image processing.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the configuration of one embodiment of the liquid crystal optical parallel A/D converter according to the present invention, and FIG. 2 is an explanatory diagram of the basic operation of the liquid crystal optical parallel A/D converter according to the present invention. It is. 1...Liquid crystal substrate A 2...Liquid crystal substrate B 3...Transparent conductive film 4...Photoconductive film 5...Mesh lattice shape insulating film 6...Liquid crystal alignment film 7...TN liquid crystal 8...Polarizing plate 9...Liquid crystal optical parallel A/D converter 10 according to the present invention...
・Input analog image 11... Output digital image 12... Drive power supply and above Applicant: Seiko Electronics Co., Ltd.

Claims (3)

[Claims] (1) A liquid crystal substrate in which a transparent conductive film is formed on a transparent substrate, a photoconductive film is formed on it, an insulating film in the form of a mesh lattice is formed, and a liquid crystal alignment film is formed thereon is designated as A, and the transparent substrate When B is a liquid crystal substrate on which a transparent conductive film is formed and a liquid crystal alignment film is formed thereon, the surfaces on which the liquid crystal alignment films of A and B are formed face each other inside, and a voltage is applied to the gap between them by changing the voltage. A liquid crystal optical parallel A/D converter characterized in that an operable liquid crystal is sealed and then sandwiched between two polarizing elements whose polarization directions are shifted from each other at an appropriate angle. (2) The liquid crystal optical parallel A/D converter according to claim 1, wherein the liquid crystal used is any one of TN liquid crystal, SmC liquid crystal, and ferroelectric liquid crystal. (3) The liquid crystal optical parallel A/D converter according to claim 1 or 2, wherein the photoconductive film used is a chalcogenide compound film or a photoconductive organic film.