JPH04204819A - Optical information processor and gradation controller - Google Patents

Abstract

PURPOSE:To display stable images free from fluctuations by using the input signal corrected by detecting the quantity of the transmitted light to a liquid crystal panel as the input to a liquid crystal driving means. CONSTITUTION:A signal synthesizing means 54 synthesizes an image signal 55 for measuring transmittance with an input digital signal 53 in such a manner that the image signal is displayed in the transmittance measurement region of the liquid crystal panel. The output of the signal synthesizing means 54 is the table address of the look up table(LUT) of a signal converting means 56 and the contents of a selected address are outputted. A photosensor outputs the quantity of the transmitted light for measuring the quantity of the transmitted light to a voltage and outputs the voltage to a control means 58. The control means 58 compares this voltage and the reference voltage corresponding to the gradation of the image measuring the quantity of the transmitted light and rewrites the table contents of the LUT of the signal converting means 56, thereby equaling the output 59 of the photosensor to the reference value of each gradation. The fluctuation in the quantity of the transmitted light of the display image of the liquid crystal panel is suppressed in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is directed to an optical system that enables stable image display on a liquid crystal panel, regardless of fluctuations in the applied voltage versus transmittance characteristics of the liquid crystal panel or the input/output characteristics of the liquid crystal driving means. Conventional technology related to information processing devices and gradation control devices FIG. 13 is a cross-sectional view of the main parts of a liquid crystal panel. In the figure, 1 is a polarizing plate, 2 is a glass plate, and 3 is formed on the inner surface of the glass plate 2. 4 is a transparent electrode formed on the transparent electrode 3; 5 is a liquid crystal layer sandwiched between 42 glass plates 2, a liquid crystal cell 6, and the liquid crystal cell 6 sandwiched between two polarizing plates 1; 14 is a block diagram of a conventional optical information processing device. In FIG. 14, 8 is a television camera (hereinafter referred to as (referred to as a TV camera), 9 is a first liquid crystal panel that displays an image captured by the TV camera 8, 10 is a semiconductor laser beam, 11 is a collimator lens that converts the light from the semiconductor laser 10 into parallel light, and 12 is a first lens. The first liquid crystal panel 9 is arranged at the focal plane of the first lens 12 on the light source side (hereinafter referred to as the front focal plane). Reference numeral 13 denotes a second liquid crystal panel, which is disposed on the focal plane opposite to the light source of the first lens 12 (hereinafter referred to as the back focal plane). Reference numeral 14 denotes a read-only memory (hereinafter referred to as ROM), which is a Fourier read-only memory (hereinafter referred to as ROM). The data of the conversion computer hologram is written with the applied voltage data corresponding to the transmittance of each pixel of the second liquid crystal panel 13. 15 is the second lens;
A second liquid crystal panel 13 is disposed on the front focal plane of the second liquid crystal panel 13. A photoelectric conversion device 16 is disposed on the rear focal plane of the second lens 15. To explain the operation of the information processing device, the image of the object to be measured displayed on the first liquid crystal panel 9 in FIG. The image of the object to be measured displayed on the first liquid crystal panel 9 is
A Fourier transformed image of the object to be measured is optically converted by the first lens 12 and formed on the second liquid crystal panel 13. Even if a Fourier transform image is formed, the second liquid crystal panel 13 is located at the front focal plane of the second lens 15, so that the optical product of the two Fourier transform images of the object to be measured and a specific standard pattern is generated. is the second
If the image of the object to be measured and the Fourier transformed image of the standard pattern match, that is, when they are the same object image, the second lens 1
A bright spot is generated on the rear focal plane of 5 and detected by the photoelectric conversion device 16. In this way, the optical filter based on the computer generated hologram displayed on the second liquid crystal panel 13 acts as a matched filter. Although it is possible to realize an optical information processing device that performs optical correlation processing, the problem to be solved by the invention is that the above-mentioned conventional configuration, however, does not allow changes in the applied voltage versus transmittance characteristics of the first liquid crystal panel due to temperature changes and liquid crystal driving means. Due to the fluctuation of the liquid crystal drive signal with respect to the input signal of
The problem is that the amplitude and phase of the transmitted light of the image displayed on the first liquid crystal panel fluctuates, making it impossible to perform stable pattern matching.Also, there are changes in the applied voltage versus transmittance characteristics of the liquid crystal panel, and the liquid crystal driving means. Due to the fluctuation of the liquid crystal drive signal with respect to the input signal of
The number of effective display gradations on the second liquid crystal panel decreases,
The present invention solves the above-mentioned conventional problems, and provides an optical information processing device and gradation control that are less susceptible to changes in characteristics of liquid crystal panels and liquid crystal driving means. Means for solving the problem In order to achieve this object, an optical information processing device of the present invention (Table 1) provides a liquid crystal panel whose transmittance is controlled by an applied voltage;
A light source that illuminates the liquid crystal panel, a light receiving means that detects the amount of light transmitted through the liquid crystal panel, a liquid crystal driving means that drives the liquid crystal panel, and an input signal corrected using the output of the light receiving means is input to the liquid crystal driving means. The optical information processing device ζ as the second invention may also have a configuration including a gradation control means.
a first light source that illuminates the liquid crystal panel; a second liquid crystal panel disposed in the optical path between the first liquid crystal panel and the first light source; and a first light source of the first liquid crystal panel. A second light source that irradiates an area that is not irradiated, a light receiving means that detects the amount of transmitted light of the first liquid crystal panel of the second light source, a liquid crystal driving means that drives the liquid crystal panel, and correction using the output of the light receiving means. The gradation control device method of the present invention may also include a gradation control means for inputting the input digital signal to the liquid crystal driving means. a signal synthesizing means for synthesizing a signal for displaying a gradation image; a signal synthesizing means for converting the output of the signal synthesizing means into a liquid crystal drive signal using an internal lookup table; The gradation control device according to the second invention has a configuration including a control means for rewriting the value of the internal look-up table of the signal conversion means according to the output of the light receiving means to be measured. a signal synthesizing means for synthesizing a signal for displaying an image of a specific gradation in a transmittance measurement area of the LCD panel; a signal converting means for converting the output of the signal synthesizing means into a liquid crystal driving signal using an internal lookup table; a control means that rewrites a value in an internal look-up table of the signal conversion means based on the output of the light reception means that measures the amount of transmitted light in the transmittance measurement area; a digital-to-analog converter that converts the digital output of the signal conversion means into an analog quantity; The present invention c! a) The light receiving means detects changes in the characteristics of the liquid crystal panel and the liquid crystal driving means, as well as changes in the intensity of the liquid crystal panel illumination light source, and the gradation control means corrects the video signal to control fluctuations in the amount of transmitted light of the image displayed on the liquid crystal panel. b) The change in the characteristics of the liquid crystal panel or liquid crystal driving means is detected by the light receiving means, the gradation control means corrects the video signal, and superimposes the change in the amplitude and phase modulated light on the liquid crystal panel. A first embodiment of the optical information processing device according to the present invention will be described below with reference to the drawings. Fig. 1 shows the optical information processing device according to the present invention. In Fig. 1, 2° is a semiconductor laser that irradiates the liquid crystal panel, 21 is a collimator lens X that collimates the light emitted from the semiconductor laser 20, and 22 is a liquid crystal spring lens. 23 is a photosensor that measures the amount of light transmitted through the liquid crystal panel 22;
24 inputs the output of the photosensor 23 and inputs the human power signal 25
26 is a liquid crystal drive means for displaying the output of the gradation control means 24 on the liquid crystal panel 22. FIG. 2 is a diagram showing the arrangement of the photosensors.

The photosensor 23 is arranged at the left end of the image display area 27 and receives the transmitted light that has passed through the transmitted light amount measurement area 28.The operation of the optical information processing apparatus in the first embodiment configured as above will be described below. First, the gradation control means 24 synthesizes the input signal 25 and a signal for displaying an image of a specific gradation in the transmitted light amount measurement area 28.
The display period of the transmitted light amount measurement image shown in FIG. In other words, the input image shown in Fig. 4(a) and the transmitted light amount measurement area display image shown in Fig. 4(b) are combined to create the composite image shown in Fig. 4(c). Transmitted light amount of transmitted light amount measurement area 28 and image display area 2
The signals are converted so that the amount of transmitted light of 7 corresponds to each other and outputted to the liquid crystal driving means 26. This conversion is performed by measuring the amount of light transmitted through the liquid crystal panel 22 when a certain human input signal is applied, and by setting a conversion coefficient in advance so that the amount of light transmitted through the liquid crystal panel 22 corresponds to the amount of light indicated by the input signal.This converted output is used to drive the liquid crystal display. A photosensor 23 arranged at the left end of the liquid crystal panel 22 is sent to the liquid crystal panel 22 by means 26.
1. Convert the amount of transmitted light of the image for measuring the amount of transmitted light into a voltage and output it to the gradation control means 24. The input signal 25 is compared with a reference voltage, and the amount of conversion of the input from the human input signal 25 to the liquid crystal driving means 26 is corrected based on the result, so that the amount of transmitted light of the image given by the input signal 25 can be obtained. According to the first embodiment of the optical information processing device, when the characteristics of the liquid crystal panel or the liquid crystal driving means change due to changes in temperature, an image of a predetermined gradation is displayed in the transmitted light amount measurement area of the liquid crystal panel. By detecting the amount of transmitted light of an image with a photosensor and correcting it with a gradation control means so that the value becomes constant, a stable image without fluctuations in the amount of transmitted light can be displayed. In FIG. 5, reference numeral 29 denotes a first liquid crystal spring that superimposes the transmitted light that has been spatially and temporally modulated on the second liquid crystal panel 22 and the displayed image. ) I, 30 is a light shielding plate for preventing the first semiconductor laser light 20 from irradiating the transmitted light amount measurement area of the first liquid crystal panel 29;
31 is a second semiconductor laser for reference for measuring the transmittance of the first liquid crystal panel 29; 32 is the transmission of the transmitted light amount measurement area of the first liquid crystal panel 29 irradiated by the second semiconductor laser 31; Photo sensor that measures the amount of light, 3
3 is a first gradation control means 3 that corrects the input signal 34 based on the output of the photosensor 32; 35 is a first gradation control means 3;
The operation of the second embodiment of the optical information processing apparatus according to the present invention configured as described above will be described below. .

The part consisting of 20 to 26 elements is the same as that in the first embodiment (
1), in which the amount of transmitted light given by the input signal 25 is obtained as transmitted light of the second liquid crystal panel 22, and the transmittance of each pixel of the first liquid crystal panel 29. By changing the second liquid crystal panel 2
Superimposition with the image represented by the transmitted light of 2 is performed.
The light measured by the photosensor 32 is transmitted to the first liquid crystal panel 29.
The transmitted light amount measurement area is irradiated by the second semiconductor laser 3. Therefore, while superimposing the image with the image whose amplitude and phase of light change temporally, the gradation control means 33 Although the transmittance of the liquid crystal panel 29 can be kept constant, the overlapping of images is shown in FIG. The first liquid crystal shown in FIG. 6(c) is a composite of the transmitted light of the second liquid crystal panel 22 shown in FIG. 6(a) and the display image of the first liquid crystal panel 29 shown in FIG. 6(b). As described above, according to the second embodiment of the optical information processing device of the present invention, when the characteristics of the liquid crystal panel and the liquid crystal drive means change due to temperature changes, the amount of light transmitted through the liquid crystal panel is L. The images are superimposed by displaying an image of a specific gradation in the measurement area, detecting the transmitted light from the light source for transmittance measurement with a photosensor, and correcting the input signal with the gradation control means so that the value remains constant. 7 is a block diagram of a third embodiment of the optical information processing device according to the present invention. In FIG. 7, 36 is a TV left camera, and 37 is a TV left camera. Photo sensor, 38 is gradation control hand north 39
is a liquid crystal driving means; 40 is a first liquid crystal panel; 41 is a semiconductor laser; 42 is a collimator lens; C43 is a first lens X; 44 is a second liquid crystal spring; 48 is a liquid crystal driving means;
49 is a second lens, 50 is a photoelectric conversion device, 51 is a front claw for transmittance measurement, and 52 is a light shielding mask.The third embodiment of the optical information processing device of the present invention configured as above will be described below. To explain its operation, the image of the object to be measured captured by the TV left camera 6 is corrected by the gradation control means 38 according to the output of the photosensor 37. This output becomes the human power of the liquid crystal driving means 39, and the first Even if displayed on the liquid crystal panel 40, the first liquid crystal panel 4
The image of the object to be measured displayed at 0 is optically converted by the first lens 43 and a Fourier transformed image of the object to be measured is formed on the second liquid crystal panel 44. At this time, the ROM
Even if the Fourier transformed image of the standard pattern stored in 45 is input to the gradation control means 46, the output of the photosensor 47 which measures the transmittance of the second liquid crystal panel 44 is input, and the image is corrected by the gradation control means 46. second liquid crystal driving means 4
This second liquid crystal panel 44 is converted into an input signal to the second lens 4 and displayed on the second liquid crystal panel 44.
9, the optical product of the two Fourier transformed images of the object to be measured image and a specific standard pattern is inversely Fourier transformed by the second lens 49. When the Fourier transformed images of the patterns match, that is, when they are the same object, a bright spot is generated in the rear focused image of the second lens 49, and the photoelectric conversion device 50
The pressure will be checked.

In this way, it is possible to realize an optical information processing device that performs optical correlation processing that functions as an optical filter filter using a computer-generated hologram displayed on the second liquid crystal panel 44. If the applied voltage vs. transmittance characteristics of the liquid crystal panel 40 or 44 or the characteristics of the liquid crystal driving means 39 or 48 change due to causes, the intensity distribution of the transmitted light of the first liquid crystal panel 40 will change. However, the amount of light transmitted through the first liquid crystal panel 40 is measured by the photosensor 37, and the amount of transmitted light of the displayed image is corrected by the gradation control means 38 so that the amount of transmitted light of the displayed image is constant. Therefore, fluctuations in light intensity are suppressed. Similarly, the force that changes the transmittance of the image displayed on the second liquid crystal panel 44 (photo sensor 4
In step 7, the transmittance of the second liquid crystal panel 44 is measured, and the gradation control means 46 performs correction to keep the transmittance of the displayed image constant, suppressing fluctuations in the transmittance. Regarding the Fourier transformed image of the standard pattern displayed on the screen, even if the number of pixels of the second liquid crystal panel 44 is the same, the higher the number of effective gradations, the more accurate pattern matching will be possible.
Use the optical information processing device according to the third embodiment! Since the transmittance fluctuation of the displayed image can be reduced, the number of effective gradation levels can be increased. The transmittance characteristics and the characteristics of the liquid crystal driving means fluctuate, making it possible to stably perform pattern matching without reducing precision.Zara & Mi The number of effective gradations of the liquid crystal panel on the Fourier transform surface can be increased, resulting in higher accuracy. 4 Next, a first embodiment of the gradation control device according to the present invention will be described. FIG. 8 is a block diagram of the first embodiment of the gradation control device according to the present invention. be. In FIG. 8, 53 is an input digital signal, 54 is a signal synthesizing means for synthesizing the input digital signal 53 and a transmittance measurement image signal 55 for displaying an image of a specific gradation in the transmitted light amount measurement area of the liquid crystal panel, and 56 is a synthesis means. The resulting digital signal is stored in an internal lookup table (hereinafter referred to as L).
A signal synthesizing means 58 converts the input signal 57 into an input signal 57 to the liquid crystal driving means (denoted as UT). A control means 58 inputs the output 59 of the photosensor and controls the signal synthesizing means 54 and the signal converting means 56. FIG. FIG. 3 is a diagram showing the configuration of an internal LOT of the signal converting means 56.The input to the signal converting means 56 becomes an address of the LUT, and the contents of the table indicated by the address are output. The operation will be explained below.The input digital signal 53 (which is converted from the amount of transmitted light of the image displayed on the liquid crystal panel) is used in the control means 58 to display an image of a specific gradation in the transmittance measurement area of the liquid crystal panel. The image signal 55 for transmittance measurement is created and outputted to the signal synthesis means 54.The signal synthesis means 54 generates the digital signal 53 manually so that the image signal 55 for transmittance measurement is displayed on the transmittance measurement area of the liquid crystal panel. The output of the signal synthesizing means 54 becomes the table address of the LUT of the signal converting means 56, and the contents of the selected address are output. The photosensor converts the amount of transmitted light of the pattern for measuring the amount of transmitted light into a voltage and outputs it to the control means 58.The control means 58 converts this voltage into the gradation of the image for measuring the amount of transmitted light. The signal converting means 5 compares the corresponding reference voltages and uses the result as a signal converter.
Rewrite the table contents of LUT 6 so that the output 59 of the photosensor becomes equal to the reference value for each gradation a. By measuring the amount of transmitted light and correcting the contents of the LUT of the signal conversion means, fluctuations in the amount of transmitted light of the displayed image on the liquid crystal panel can be suppressed.Next, a second embodiment of the gradation control device according to the present invention 10 is a block diagram of a second embodiment of the gradation control device according to the present invention. In FIG. 10, 60 is a digital input signal, and 61 is a digital input signal 60 and an image signal for transmittance measurement. 63 is a signal converting means, and 64 is a digital-to-analog converter (hereinafter referred to as D/analog converter) that converts the digital output of the signal converting means 63 into an analog quantity.
A converter), 65 is a signal synthesizing means for correcting the output of the D/A converter 64 according to the characteristics of the liquid crystal panel, and outputting it as an input signal 66 for the liquid crystal driving means; 67 is a signal for inputting the output 68 of the photosensor; Combining means 61 and signal converting means 63
FIG. 11(a) shows the relationship between the output of the D/A converter 64 and the transmittance of the liquid crystal panel when the signal correction means 65 is not used. ii, where the change in transmittance is large with respect to the output voltage of the D/A converter 64;
A signal correction means 65 is provided after the D/A converter 64.
If we correct the non-linear characteristic of the applied voltage vs. transmittance of the liquid crystal panel by providing By providing the signal correction means 65, the transmittance of the liquid crystal panel can be specified at equal intervals. By providing the signal correction means 65 at the subsequent stage and correcting the applied voltage versus transmittance characteristics of the liquid crystal panel, it is possible to control the transmittance with higher accuracy than when the number of conversion bits of the D/A converter 64 is the same. Also, if the accuracy is the same, the number of conversion bits of the D/A converter can be reduced, and faster conversion is possible. It may be the upper end or the lower end or a combination thereof.Furthermore, the photosensors 23, 32, 37,
47 is singular, but it may be plural, Xo and
The liquid crystal panel has no specified force <, TN supervision Dynamic scattering supervision Either a guest host type or an electric field controlled birefringence type may be used.Also, the photosensor 23 directly receives the transmitted light of the liquid crystal panel. (The light source 31 for transmittance measurement may also be moved away from the liquid crystal display surface using the optical path changing means.)
51 is a force that directly irradiates the transmitted light amount measurement area 28 (after changing the optical path by the optical path changing means, the transmitted light amount measurement area 2
In addition, in the optical information processing device of the second embodiment shown in FIG. As shown in the figure, the emitted light from the first semiconductor laser 20 is split by a beam splitter 69 and mirrors 70, 71, 7
2 and irradiate the first liquid crystal panel 29.
In FIG. 12, the same parts as in the embodiment shown in FIG. 5 are given the same reference numerals, and detailed explanations are omitted. Voltage vs. Transmittance Method Input/Output Method of LCD Drive Device A stable image can be displayed without fluctuation even if the light intensity of the light source fluctuates.b) Applied voltage vs. transmittance method of LCD panel due to temperature changes, etc. Liquid crystal Even if the human output characteristics of the drive device fluctuate, it is possible to display a stable image without fluctuations by superimposing images, and the number of effective display gradations can be increased. Due to fluctuations in applied voltage vs. transmittance characteristics and fluctuations in the characteristics of the liquid crystal driving means, pattern matching cannot be performed stably without reducing accuracy.D) Even worse: The number of effective gradations of the liquid crystal panel on the Fourier transform surface It has excellent effects such as increasing the number of patterns, making it possible to perform pattern matching with higher accuracy.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a first embodiment of the optical information processing device according to the present invention. FIG. 2 shows the arrangement of photosensors.
The figure shows the display period of the transmitted light amount measurement image.
a) to (C) show the composition of images according to the first embodiment; FIG. 5 shows the configuration of the second embodiment of the optical information processing device according to the present invention; FIGS. FIG. 7 is a block diagram of the third embodiment of the optical information processing device according to the present invention. FIG. 8 is a diagram showing the configuration of the third embodiment of the gradation control device according to the present invention. Configuration diagram FIG. 9 shows the configuration of the internal look-up table of the signal conversion means. FIG. 10 is the configuration of the second embodiment of the gradation control device according to the present invention. Part 12 shows the relationship between the output of the D/A converter and the transmittance of the liquid crystal panel.
13 is a cross-sectional view of the main part of a liquid crystal panel; FIG. 14 is a configuration diagram of a conventional optical information processing device. 20... Semiconductor sensor (light source), 22... Liquid crystal spring/l, 23... Photo sensor (light receiving means), 24
... Gradation control half-dark 25 ... Input signal 26 ...
Name of agent for liquid crystal driving means: Patent attorney Akira Okaji and two others Figure 1〃--)Two series I$+-ty"23---+<11-"
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-- J n ・v , 1-L Fig. 2 Fig. 4 Stand / allowance &, (Sewing Fig. 5 Input No. 41 △7'7I
LCD panel X in Fig. 6 Ning 2! iJJ, tl's 1-hole imitation, and tPFl's near liquid crystal. Figure 12 Figure 13\

Claims (4)

[Claims] (1) A liquid crystal panel whose transmittance is controlled by an applied voltage, a light source that illuminates the liquid crystal panel, a light receiving means that detects the amount of light transmitted through the liquid crystal panel, and a liquid crystal driving means that drives the liquid crystal panel. , an optical information processing device comprising gradation control means for inputting an input signal corrected using the output of the light receiving means to the liquid crystal driving means. (2) A first liquid crystal panel whose transmittance is controlled by an applied voltage, a first light source that illuminates the first liquid crystal panel, and a light source between the first liquid crystal panel and the first light source. a second liquid crystal panel disposed in the optical path; and a second liquid crystal panel that illuminates an area of the first liquid crystal panel that is not illuminated by the first light source.
a light source, a light receiving means for detecting the amount of transmitted light of the first liquid crystal panel of the second light source, a liquid crystal driving means for driving the liquid crystal panel, and an input signal corrected using the output of the light receiving means. An optical information processing device including gradation control means for input to liquid crystal driving means. (3) A signal synthesizing means for synthesizing the input digital signal and a signal for displaying an image of a specific gradation in the transmittance measurement area of the liquid crystal panel, and converting the output of this signal synthesizing means into a liquid crystal driving signal using an internal lookup table. a signal converting means for
A gradation control device comprising: a light receiving means for measuring the amount of transmitted light in a transmittance measurement area of a liquid crystal panel; and a control means for rewriting a value in an internal lookup table of the signal converting means based on the output of the light receiving means. (4) A signal synthesis means for synthesizing the input digital signal and a signal for displaying an image of a specific gradation in the transmittance measurement area of the liquid crystal panel, and the output of this signal synthesis means is converted into a liquid crystal drive signal by an internal lookup table. a signal converting means for converting the signal; a light receiving means for measuring the amount of transmitted light in a transmittance measurement area of a liquid crystal panel; a control means for rewriting a value in an internal lookup table of the signal converting means based on the output of the light receiving means; A gradation control device comprising: a digital-to-analog converter for converting the digital output of the means into an analog quantity; and a correction means for correcting the output of the digital-to-analog converter in accordance with the characteristics of a liquid crystal panel.