JPH08149522A - Position detector and image correction device - Google Patents

Abstract

PURPOSE: To realize a position detector detecting a position of a test pattern to automatically conduct correction of convergence distortion and geometrical distortion in a projection television receiver and an image correction device conducting automatic adjustment in a short time with high accuracy depending on the position. CONSTITUTION: Photodetection section 8-15 comprising plural photodetectors are provided in an outer circumferential part of a screen 7 on which an image is displayed. Furthermore, a test pattern generating circuit 1 generates a test pattern and it is received by the photodetection sections 8-15. A position calculation section 17 detects the display position of the test pattern from the light receiving signal. An error detection section 18 calculates an error of the display position based on the detected position. A correction signal generating circuit 19 generates a correction signal based on the error and gives the signal to a convergence correction circuit 20 and a deflection circuit 21. Thus, image distortion is detected in a short time with high accuracy and the distortion is automatically adjusted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for correcting image distortion of a color television receiver, and a position detecting apparatus for detecting positional deviation of the three primary colors on a screen and automatic convergence and geometric distortion correction. The present invention relates to an image correction device that performs

[0002]

2. Description of the Related Art Generally, in a projection type display for enlarging and projecting an image on a screen using a projection tube which emits light of three primary colors, such as a concentration angle of the three primary color projection tubes with respect to the screen and a projection angle of the projection type display with respect to the screen. Due to optical conditions, geometric distortion, which is image distortion, and misconvergence occur.

Since adjustment of geometrical distortion and convergence is very complicated in a projection type display and adjustment takes a long time manually, as a method for performing automatic adjustment, Japanese Patent Publication No. 6-32486 and Registration No. 1685724 disclose. An automatic convergence correction method has been proposed. In addition, as a method for automatically adjusting the convergence drift that occurs due to the influence of the electric / material / mechanical fluctuation of the receiver and the geomagnetism after the convergence adjustment, there is a method disclosed in Japanese Patent Publication No. 6-9393.
Japanese Patent Publication No. 6-5960, US Patent No. 4857.
The position detection device and the image correction device disclosed in Japanese Patent Laid-Open No. 998 and Japanese Patent Laid-Open No. 63-48987 are proposed.

Convergence drift is a combination of neck charge of the projection tube, gun center drift, etc., drift of each drive output circuit, material sensitivity fluctuations of the convergence yoke and deflection yoke, and mechanical fluctuations such as geomagnetism and transportation. It is a thing.

FIG. 87 shows a basic configuration of a conventional image correction device for automatically adjusting the position and a position detection device (Japanese Patent Publication No. 6-32486 "photodiode array and misregistration detection circuit") used in this device. Indicates. As shown in FIG. 87 (a), there is provided a focusing system which comprises a quadrant photodiode sensor 331 which is in synergistic relation with the imaging lens 333 and which is attached to the XY motor assembly 335. XY motor assembly 335
Has a mechanical structure that supports two stepper motors 337 on the XY gimbal for focusing the imaging lens 333 and the quadrant photodiode sensor 331 onto the projected image (not shown). ing. A tubular housing 334 having an imaging lens 333 provided at one end and a quadrant photodiode sensor 331 provided at the other end is rotatably attached.

The quadrant photodiode sensor 331 is mounted on a small surface mount preamplifier board. X
The -Y motor assembly 335 is preferably mounted to the projector frame, just below the center lens of the projector (not shown). The wire wiring 339 connects the quadrant photodiode sensor 331 and the step motor 337 to the parent board 311 in the card cage 313. The card cage 313 has a drive circuit for the step motor 337 and also has a circuit for digitizing the signal taken in from the quadrant photodiode sensor 331. These circuits are provided on the main printed circuit board 315.

The position of each of the red (R), green (G) and blue (B) image components at the projected image point is detected by the quadrant photodiode sensor 331 and adjusted to coincide with the center of the quadrant. .
Convergence across the screen is achieved by repeating this operation for multiple convergence points in the raster image. The autofocus operation is initiated by the selection of the focus menu via the projector's remote or built-in cue pad (not shown). The software running in the convergence system then controls the projector until convergence is complete or interrupted by the user.

In such an operation, the microprocessor in the video control board built into the card cage 313 controls to display the targets and patterns required for the convergence algorithm. Fig. 87
(B) is a block diagram of a quadrant photodiode sensor 331. As shown in this figure, the quadrant photodiode sensor 3
Reference numeral 31 includes photodiodes 321A to 324A and photodiodes 321B to 324B arranged at the four corners thereof.

Each photodiode 321A-324
Each DC voltage (that is, a photovoltaic potential) proportional to the position of the image is obtained from A, and those signals are given to an analog / digital converter (hereinafter referred to as an A / D converter). In response to this, the A / D converter outputs an 8-bit digital value and supplies it to the data bus of the microprocessor of the convergence system. The microprocessor detects the image misregistration in a well-known manner by comparing the 8-bit digital values and generates the necessary focusing coil correction signals to provide automatic adjustment of the registration.

FIG. 88 is a basic configuration diagram of a conventional image correction apparatus ("convergence apparatus" of US Pat. No. 4,857,998) for automatically adjusting drift. Screen 4
Photosensors 414 and 415 arranged in the periphery of 13
The detection test signals 416 and 417 are detected at. This detection signal is applied to the position detection circuit 418 to obtain the convergence error value. Thereby, the convergence drift of the display is automatically adjusted through the convergence correction circuit (C correction circuit) 421. In this way, the drift adjustment can be automatically performed while the image is displayed on the projection screen.

[0011]

However, in the above-mentioned structure, by comparing the outputs of a plurality of photodiodes arranged in a quadrant, the pattern for registration adjustment is converged at the intersection of the photodiodes. I am trying to let you. Then, the display position coordinates of the pattern are detected from the movement amount when the pattern is moved to the convergence point. In such a method, the adjustment accuracy depends on the resolution of the pattern movement amount. Further, there is a problem in that adjustment requires a time required for moving the pattern, which requires adjustment time.

Further, when a detector is provided in the peripheral portion of the screen for detection, complicated signal processing is required for accurate detection, and the circuit scale becomes large. Further, considering the convergence drift of the device and the fluctuation of the screen phase, there is a problem that a large light receiving area of the detector is required, and a very expensive sensor is required as the detector.

The present invention has been made in view of the above conventional problems, and in the projection type color display device, when the geometric distortion of an image or the convergence adjustment is performed, the display position of the adjustment pattern is adjusted. It is an object of the present invention to realize a position detection device that detects coordinates with high accuracy and to provide an image correction device that can perform geometric distortion and convergence adjustment with high accuracy in a short time using this position detection device. To do.

[0014]

According to a first aspect of the present invention, a plurality of light beams are provided on an outer peripheral portion of a display screen, and a plurality of light detecting elements are arranged close to each other along at least one direction of the display screen. The detector and the photodetector of the photodetector generate a test pattern whose signal level changes along the arrangement direction of the photodetector of the photodetector at a position where the photodetector can receive light. A pattern position calculating means for calculating the display position of the test pattern from the received signal level is provided.

According to the invention of claim 5 of the present application, a plurality of photodetector elements arranged at predetermined positions on the outer peripheral portion of the image display screen, and a test for generating a test pattern in which the signal level changes along the plane of the display screen. The pattern generation means, the display position control means for controlling the display position of the test pattern generated by the test pattern generation means within a range that can be received by the photodetector, the signal level received by the photodetector and the display position control means. A pattern position calculating means for calculating the display position of the test pattern from the control amount is provided.

According to the invention of claim 8 of the present application, a plurality of photodetector units are provided on the outer peripheral portion of the image display screen, and a plurality of photodetector elements are arranged adjacent to each other along the display screen, and each photodetector unit. Test pattern generating means for generating a test pattern having an irradiation range smaller than the light receiving area of the photodetector at a position where the photodetector can receive light, and two-dimensional coordinates on the display screen are assigned to the respective photodetector elements. And a position calculating means for calculating the display position of the test pattern by weighting and adding the outputs of the above with the assigned coordinates.

According to a tenth aspect of the invention of the present application, a plurality of photodetection portions which are provided on the outer peripheral portion of the display screen and in which a plurality of photodetection elements are arranged close to each other at least along one direction of the display screen, and position detection. And a test pattern for error detection, a test pattern generating means for generating at a position where the photodetector can receive light, and a pattern position calculating means for calculating the display position of the test pattern from the signal level received by the photodetector,
From the signal of the pattern position calculating means, an error calculating means for calculating the correction direction of the geometrical distortion as image distortion and the convergence error, and a correction signal creating means for creating a signal for correcting the error of the image distortion from the output of the error calculating means. And is provided.

According to a twelfth aspect of the present invention, a plurality of photo-detecting elements are arranged obliquely with respect to the horizontal and vertical scanning directions at the four corners of the image display screen, and horizontal scanning is performed at the outer periphery of the long side of the display screen. Direction, and a plurality of photodetectors with a plurality of photodetectors arranged in the vertical scanning direction on the outer periphery of the short side of the display screen, and a test pattern at a position where the photodetectors can receive light. Generated test pattern generation means, pattern position calculation means for calculating the display position of the test pattern from the signal level received by the photodetector element, and the signal of the pattern position calculation means from the geometric distortion as image distortion and the convergence error. An error calculating means for calculating a correction direction and a correction signal generating means for generating a signal for correcting an error of image distortion from an output of the error calculating means. A.

According to a fourteenth aspect of the present invention, a plurality of photodetector portions, each of which has a plurality of photodetector elements arranged on the outer periphery of the display screen, and a test pattern generator for generating a test pattern at a position where the photodetector elements can receive light. Means and a pattern position calculating means for calculating the display position of the test pattern based on a value obtained by adding and subtracting the signals received by the photodetector, and geometric distortion as image distortion from the signal of the pattern position calculating means. It is characterized by comprising an error calculation means for calculating the correction direction of the convergence error and a correction signal generation means for generating a signal for correcting the image distortion error from the output of the error calculation means.

The invention according to claim 17 of the present application is a test for generating a test pattern at a position where a plurality of photodetector elements are arranged on the outer peripheral portion of an image display screen and at a position where the photodetector elements can receive light. The pattern generating means, the pattern position calculating means for calculating the display position of the test pattern based on the signal level received by the light detecting element, and the signal of the pattern position calculating means, the geometric distortion as the image distortion and the correction direction of the convergence error are determined. An error calculating means for calculating and a peripheral portion correction signal generating means for generating a correction signal only for the peripheral portion of the screen, which is a detection area, by the output of the error calculating means, and a convergence waveform by the correction waveform from the peripheral portion correction signal generating means. Drive the means to converge the display position of the test pattern,
And a full-screen correction signal creating means for creating a full-screen correction signal based on the convergence result.

According to a twentieth aspect of the invention of the present application, a plurality of photo-detecting portions in which a plurality of photo-detecting elements are arranged on an outer peripheral portion of an image display screen, and a test for generating a test pattern at a position where the photo-detecting elements can receive light. The pattern generating means, the pattern position calculating means for calculating the display position of the test pattern on the basis of the signal level received by the light detecting element, and the geometrical distortion and the convergence as image distortion at predetermined time intervals from the signal of the pattern position calculating means. It is characterized by comprising an error calculation means for calculating a correction direction of the error and a correction signal generation means for generating a signal for correcting the error of the image distortion from the output of the error calculation means.

According to a twenty-fourth aspect of the present invention, a plurality of photodetector units each having a plurality of photodetector units arranged on the outer periphery of the image display screen, and a test for generating a test pattern at a position where the photodetector units can receive light A signal of the pattern generating means, a pattern position calculating means for calculating the display position of the test pattern from the position / voltage conversion signal in which the position information corresponding to the light receiving position from the light detecting element is converted into voltage information, and the signal of the pattern position calculating means. Error calculation means for calculating the correction direction of the geometrical distortion as image distortion and the convergence error, and correction signal generation means for generating a signal for correcting the image distortion error from the output of the error calculation means. It is what

The invention according to claim 27 of the present application is a position detecting device for detecting the display position of a test pattern displayed on a display screen, wherein a plurality of photodetection elements are arranged adjacent to each other on the outer peripheral portion of the display screen. A plurality of photodetectors, a test pattern generating means for generating a linear test pattern whose signal level changes in the width direction at a position where the photodetector can receive light, and a display screen for each photodetector in the photodetector. Pattern position calculation means for calculating the display position of the test pattern by assigning the above coordinates, and adding the output ratio of each photodetector element by weighting with the coordinates assigned to each photodetector element,
It is characterized by including.

A thirty-first aspect of the invention of the present application is a position detecting device for detecting the display position of a test pattern displayed on a display screen, comprising a plurality of photodetection elements arranged on the outer periphery of the display screen and a signal level. Of a linear test pattern whose width changes in the width direction is generated at a position where the photodetector can receive light, and the display position of the test pattern generated from the test pattern generating means is finely moved in a time-division manner within the pattern width. By calculating the output ratio of the display position control means and each detection signal output from the photodetector in a time division manner, and weighting and adding this output ratio with the movement amount of the test pattern output from the display position control means. , Pattern position calculation means for calculating the display position of the test pattern,
It is characterized by including.

A thirty-fifth aspect of the present invention is a position detecting device for detecting a display position of a test pattern displayed on a display screen, wherein a plurality of photodetection elements are arranged adjacent to each other on the outer peripheral portion of the display screen. When a plurality of photodetectors and a linear test pattern whose signal level changes in the width direction are applied to the photodetector, the test pattern generation occurs so that the width of the test pattern becomes smaller than the light receiving area of the photodetector. Means and
The minimum value calculating means for detecting the minimum value of the outputs of the respective photodetecting elements in the photodetecting section as the unnecessary light level, and the output of the minimum value calculating means is subtracted from the respective outputs of the respective photodetecting elements in the photodetecting section. A plurality of differentiating means and a pattern position calculating means for calculating the display position of the test pattern from the output of the differentiating means corresponding to each photodetecting element in the photodetecting section.

According to a thirty-ninth aspect of the present invention, there is provided an image correction apparatus which detects a display position of a test pattern for detecting image distortion and corrects image distortion when an image is displayed on the display screen. A plurality of photodetection sections in which a plurality of photodetection elements are arranged adjacent to each other on the outer periphery, and a test pattern generating means for generating a linear test pattern in which the signal level changes in the width direction at a position where the photodetection elements can receive light An image averaging means for averaging the level of the input image signal at least in field units, and switching between the output of the image averaging means and the test pattern output by the test pattern generating means.
Switching means, second switching means for switching between the output of the first switching means and an input image signal, and switching to the output of the first switching means by using the second switching means when correcting an image on the display screen. A timing generation section for giving a switching timing signal to the first switching means so that the output image of the image averaging means is displayed in the effective display range of and the test pattern of the test pattern generation means is displayed on the outer peripheral portion of the display screen. By assigning coordinates on the display screen to each photodetector in the photodetector and weighting the output ratio of each photodetector with the coordinates assigned to each photodetector, the display position of the test pattern is determined. The pattern position calculating means for calculating, the error calculating means for calculating the correction direction of the geometrical distortion of the image and the convergence error from the signal of the pattern position calculating means, and the output from the error calculating means Is characterized in that it comprises a correction signal generating means for generating a signal for correcting the error of the distortion, the.

The invention according to claim 41 of the present application is an image correction apparatus for correcting the image distortion by detecting the display position of a test pattern for detecting the image distortion when the image is displayed on the display screen. A plurality of photodetection sections in which a plurality of photodetection elements are arranged adjacent to each other on the outer peripheral portion, a test pattern generating means for generating a linear test pattern at a position where the photodetection elements can receive light, and a test pattern generating means The display position of the linear test pattern, display position control means for sequentially moving from the reference position to the left or right or up and down of the display screen at an integral multiple of the minimum pitch, and when the detection signal of the test pattern is obtained in the photodetector, From the pattern position calculation means for calculating the display position of the test pattern based on the number of times of movement of the test pattern designated by the display position control means, and the signal of the pattern position calculation means The image forming apparatus further comprises: an error calculating unit that calculates a geometric distortion as an image distortion and a correction direction of the convergence error; and a correction signal creating unit that creates a signal for correcting the image distortion error from the output of the error calculating unit. It is what

The invention according to claim 44 of the present application is a test for detecting image distortion when an image is displayed by a plurality of magnifying projection tubes on a multi-display screen in which a plurality of display screens are arranged vertically and horizontally. An image correction device that detects the display position of a pattern and corrects image distortion, and is located on the magnifying projection tube side from each display screen, and a plurality of photodetection elements are arranged adjacent to each other on the radiation outer peripheral portion of each projection beam. When the distance between the light detection units and the magnifying projection tube is set as the projection distance, the first test pattern for calculating the projection distance and the second test pattern for detecting the image distortion are A test pattern generating means that is generated at a position where the light detecting element of the detecting section can receive light;
From the output of the photodetection element of each photodetector and the output of the projection distance calculation means, the projection distance calculation means for calculating the projection distance to the photodetection section based on the signal level of the first test pattern received by the photodetection element From the output of the error calculation means, the pattern position calculation means for calculating the display position of the second test pattern, the error calculation means for calculating the correction direction of the geometrical distortion as the image distortion and the convergence error from the signal of the pattern position calculation means. And a correction signal generating means for generating a signal for correcting an error of image distortion.

The invention of claim 46 of the present application is a test for image distortion detection when an image is displayed by a plurality of magnifying projection tubes on a multi-display screen in which a plurality of display screens are arranged vertically and horizontally. An image correction device that detects the display position of a pattern and corrects image distortion, and is located on the magnifying projection tube side from each display screen, and a plurality of photodetection elements are arranged adjacent to each other on the radiation outer peripheral portion of each projection beam. When the distance between the light detection units and the magnifying projection tube is set as the projection distance, the first test pattern for calculating the projection distance and the second test pattern for detecting the image distortion are A test pattern generating means that is generated at a position where the light detecting element of the detecting section can receive light;
The projection distance calculation means for calculating the projection distance to the photodetection unit based on the signal level of the first test pattern received by the photodetection element, and the display position of the second test pattern based on the output of the projection distance calculation means. Display position control means for fine movement,
Pattern position calculating means for calculating the display position of the second test pattern from the output of the light detecting element of each light detecting section, and geometric distortion as image distortion and the correction direction of the convergence error are calculated from the signal of the pattern position calculating means. Error calculating means and correction signal generating means for generating a signal for correcting the error of the image distortion from the output of the error calculating means.

[0030]

According to the inventions of claims 1 to 4 having the above-mentioned features, a test pattern in which the signal level changes is displayed on the photodetection section provided with a plurality of photodetection elements. By comparing the signal level of each photodetector,
Calculate the display position of the test pattern. By doing so, the direction of the test pattern and the amount of deviation can be detected directly, so that image distortion can be detected with high accuracy in a short time.

Further, according to the inventions of claims 5 to 7 of the present application,
A test pattern whose signal level changes with respect to the detection direction is moved by a predetermined amount. At this time, the display position of the test pattern is calculated from the change in the signal level obtained from the single photodetector. By doing so, the direction of the test pattern and the amount of deviation can be directly detected by the photodetector, so that image distortion can be detected with high accuracy in a short time.

According to claims 8 and 9 of the present application,
For each of the plurality of photodetector elements arranged at a predetermined position,
Allocate two-dimensional plane coordinates on the display screen. Then, a spot-shaped test pattern is displayed, and the coordinates assigned by the output of each photodetector are weighted and added, whereby the display position of the test pattern is directly calculated. In this way, the direction of the test pattern and the amount of deviation can be easily detected by the photodetector, so that image distortion can be detected with high accuracy in a short time.

According to the tenth and eleventh aspects of the present invention, two types of test patterns for position detection (signal search) and error detection are used to calculate the error in the direction and display position. A correction signal for correcting geometrical distortion and convergence distortion is created based on this error value. This makes it possible to correct image distortion with high accuracy in a short time with a simple configuration.

According to the twelfth and thirteenth aspects of the present invention, a plurality of photo-detecting elements are installed on the screen cross at right angles to the scanning directions and at the four corners obliquely to the scanning directions. . Then, the display position of the test pattern is calculated, and a correction signal for correcting the geometrical distortion or the convergence distortion is created. This allows stable and highly accurate automatic adjustment of image distortion.

According to the invention of claims 14 to 16 of the present application, detection signals obtained from a plurality of photodetector elements are added,
The approximate direction and generation position of the test pattern are controlled based on the addition signal. Further, the detection signal obtained from each detection element is subtracted, and the error in the display position of the test pattern is calculated by the subtraction signal. In this way, by detecting the error value of the display position in two stages, it is possible to automatically and stably correct the geometric distortion and the convergence distortion with high accuracy. Further, since the subtraction value is used as the error signal value, the influence of unnecessary light on the photodetector is reduced.

According to the seventeenth to nineteenth aspects of the present invention, first, the converging operation is performed only in the detection area of the photo-detecting element installed in the peripheral portion of the screen, and then the converging operation of the entire screen is performed. Then, by correcting the geometric distortion and the convergence distortion, it is possible to stably and accurately adjust the image distortion automatically without disturbing the image on the effective screen.

Further, according to the invention of claims 20 to 23 of the present application, the test pattern is output with the lapse of time after the power of the image display device is turned on. Then, the position shift amount of the test pattern is detected from the value projected on the photodetection element and subjected to the position / voltage conversion. An image distortion correction signal is created in synchronization with this detection signal. By doing so, the drift of the image distortion can be corrected with high accuracy.

Further, according to the inventions of claims 24 to 26, test patterns for position detection (for signal search) and error detection are created respectively. These test patterns are displayed, and the display position is detected by position / voltage conversion. This makes it possible to correct image distortion with high accuracy in a short time using a simple test pattern.

According to the twenty-seventh to thirtieth inventions of the present application, the display position of the test pattern is calculated from the output ratio of the photodetector. In this case, the influence of the gain variation of the test pattern and other variation factors is less likely to occur, and the direction and the amount of deviation of the test pattern can be directly detected, so that the image distortion is detected with high accuracy in a short time.

According to the inventions of claims 31 to 34 of the present application, the display position of the test pattern is directly calculated from the output ratio of the brightness level when the display position of the test pattern is shifted. This makes it possible to detect image distortion with high accuracy and in a short time with a simple configuration.

Further, according to the invention of claims 35 to 38 of the present application, by using the test pattern having the irradiation area narrower than the light receiving range of the photodetector, the test pattern is not irradiated and only the unnecessary light is incident. Unnecessary light components are detected from the photodetecting elements in the existing portions, and the unnecessary light components are subtracted from the output of each photodetecting element to calculate the display position of the test pattern. In this way, unnecessary light such as reflected light and external light inside the projection device set can be removed, so that stable and highly accurate image distortion can be detected.

According to the invention of claims 39 and 40 of the present application, the average value of the video signal and the test pattern are switched and output, and the positional deviation amount of the test pattern is calculated to generate the image distortion correction signal. . This way multi-scan,
When performing multi-aspect image distortion correction, the test pattern insertion operation is inconspicuous and the image distortion can be automatically adjusted with high accuracy.

Further, according to the inventions of claims 41 to 43 of the present application, the display position of the test pattern is controlled, and the image distortion correction signal is generated from the detection signal and the control amount. In this way, the test pattern can be searched with a small number of times, and the efficiency of the search and the adjustment time can be shortened.

According to the inventions of claims 44 and 45 of the present application, the projection distance to the detection portion is calculated from the brightness level of the test pattern, and the image distortion correction signal is created from this calculation signal and the detection signal. This allows accurate automatic adjustment of image distortion even when the photodetector is arranged on the non-imaging surface as in a multi-screen display.

According to the 46th and 47th aspects of the present invention, the projection distance to the detection unit is calculated from the brightness level of the test pattern, and the phase of the test pattern is controlled by this calculation signal to correct the image distortion. To create. In this way, the actual position on the non-imaging plane can be detected, and more accurate image distortion can be automatically adjusted.

[0046]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A position detecting device according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the overall configuration of an integrated video projector (projection display). FIG. 2 is a side view showing the structure of the projection display. As shown in FIGS. 1 and 2, the projection display 27 includes a magnifying projection device 24 including an R, G, and B CRT 4 and three lenses 5, a mirror 6, a screen 7, an automatic adjustment device 25, and a position detection device. 26 is included.

The position detecting device 26 is the magnifying projection device 24.
This is a device for detecting the positional deviation of the R, B, and G images projected by. In each of the embodiments described below, the position detection device detects the position of the test pattern required for automatic adjustment of geometric distortion and convergence of the image, but it is also effective when detecting the position of another pattern. is there.

In FIG. 1, a test pattern generating circuit (TP generating circuit) 1 is a circuit for generating a test pattern for geometric distortion and convergence adjustment, and its output is given to a switching circuit 2. The switching circuit 2 is a circuit for switching a video signal and a test pattern signal input from the outside, and the output thereof is given to the video circuit 3. Video circuit 3
Performs various processing on the input signal,
This is a circuit for driving the G CRT 4. The three lenses 5 are lenses for magnifying and projecting the image displayed on each CRT 4 on the screen 7 via the mirror 6 as shown in FIG.

The photodetectors 8 to 15 are devices arranged at predetermined positions on the periphery of the screen 7 to detect the signal level of the displayed test pattern. The multiplexer 16 in FIG. 1 is a circuit that receives the output signals of the photodetectors 8 to 15 and selects a signal to be processed. The position calculation unit 17 is a circuit that processes the output signal of the multiplexer 16 and calculates the display position of the test pattern. In this way, the photodetector 8 ...
15, the multiplexer 16, and the position calculation unit 17 constitute a position detection device 26 that detects the display position of the test pattern displayed on the light detection units 8 to 15 on the screen 7.

The error calculator 18 is a circuit for calculating the geometric distortion and the amount of misconvergence from the output of the position calculator 17. The correction signal generation circuit 19 is a circuit that generates a correction signal for geometrical distortion and convergence error correction based on the output of the error calculation unit 18, and its output is a convergence correction circuit (C correction circuit) 20 and a deflection circuit. 21 and 21. Here, the test pattern generation circuit 1 and the error calculation unit 1
8. The correction signal generation circuit 19 constitutes an automatic adjustment device 25 for automatically adjusting geometric distortion and misconvergence of an image.

The convergence correction circuit 20 is a circuit which outputs a control signal for convergence correction to a convergence yoke (hereinafter referred to as CY) 22. Deflection circuit 21
Is a circuit for outputting control signals for deflection control and deflection correction to a deflection yoke (hereinafter referred to as DY) 23. Thus, the magnifying projection device 24 includes the switching circuit 2, the video circuit 3, and the CY2.
2 and DY 23 are mounted on the CRT 4, the lens 5, the convergence correction circuit 20, the deflection circuit 21, and the like.

In FIG. 2, the image light from the projection enlarging device 24 is reflected by the mirror 6, and the transmission type screen 7 is displayed.
Is enlarged and projected. The mirror 6 provided between the projection enlarging device 24 and the screen 7 is an optical reflection means for shortening the depth of the set of the integrated video projector 27. As described above, the automatic adjustment device 25 projects a test pattern in which the signal (luminance) level changes on the light detection units 8 to 15 arranged on the screen 7, and detects the test pattern from the detection signal of this light detection unit. The display position is detected and the geometrical distortion and misconvergence of the magnifying projection device 24 are automatically adjusted.

The operation of the position detecting device 26 of this embodiment provided in the VSP having such a configuration will be described. In the automatic adjustment of the geometric distortion and the convergence, the position coordinate of the displayed test pattern is calculated by the position calculation unit 17, the geometric distortion and the misconvergence error are calculated from the obtained position coordinates, and the position error is calculated according to the error amount. This is performed by supplying a correction signal to the convergence correction circuit 20 and the deflection circuit 21.

Here, the operation of detecting the position coordinates of the test pattern of this embodiment will be described in detail. First, the light detection units 8 to 15 and the position detection device 26 arranged at predetermined positions on the peripheral portion of the display screen will be described with reference to FIG. When the screen 7 is a two-dimensional plane, the photodetector elements 30 to 32 shown in FIG.
Horizontal direction (called x direction), vertical direction (called y direction)
A photodiode or a phototransistor arranged along the line. Peak hold circuit (PH circuit) 33,
Reference numerals 34 and 35 are circuits for inputting the signals of the photodetecting elements 32, 31, 30 respectively and holding the peak values thereof. The difference circuit 36 includes the photo detectors 31 and 3 arranged in the horizontal direction.
2 is a circuit for calculating a difference value between two outputs. Difference circuit 37
Is a circuit for calculating the difference value between the outputs of the photodetector elements 30 and 31 arranged along the vertical direction.

The output of the two difference circuits 36 and 37 and the peak hold circuit 3 which is a signal common to the horizontal and vertical directions.
The output of 4 is supplied to the switching circuit 120. Switching circuit 12
Reference numeral 0 denotes an analog switch or the like, which inputs two difference signals and the signal of the peak hold circuit 34 and selects a signal required for coordinate calculation. The circuit indicated by the broken line L1 shows the configuration of only the photodetector 8 of the photodetectors 8 to 15, but the same applies to the other photodetectors 9 to 15.

The analog DC signal from the switching circuit 120 is passed through the multiplexer 16 to A / A in the position detecting section 17.
It is given to the D converter 121. The A / D converter 121 converts the input signal into digital data and outputs the digital data to the coordinate calculation circuit 122 including a CPU or the like. Coordinate calculation circuit 1
Reference numeral 22 is a circuit for calculating the position coordinates from the level value of the input signal and giving the coordinate output to the error calculating unit 18 in FIG.

Next, the test pattern of this embodiment will be described. As shown in FIG. 4A, the test pattern generation circuit 1 is a circuit that generates a test pattern projected at a predetermined position in the overscan area in the peripheral portion of the screen 7. The test pattern here is a test signal whose luminance level changes in the horizontal and vertical directions of the display surface (screen) as shown in FIG. 4B, and for example, a test pattern having a linear chevron-shaped luminance distribution. 40-47. In order for the test pattern displayed on the screen 7 to be linear in the luminance level direction in this way, gamma correction of the magnifying projection device 24 is required.

The test pattern generation circuit 1 considering the gamma correction will be described. Generally, the relationship between the input signal voltage E of the CRT and the light emission output L can be approximated by the following equation (1).

[Equation 2] The index γ of the input signal voltage E in this expression represents the gamma characteristic of the CRT, and this value is generally γ = 2.2. Since this gamma characteristic is an amount that is uniquely determined for the CRT, the input signal voltage E is converted as follows using a ROM, for example, in the test pattern generation circuit.

(Equation 3) Then, the light emission output L becomes L = k · E and is linear with respect to the input. In the following description, it is assumed that the gamma characteristic is corrected in this way.

Next, using such a test pattern,
A method of calculating the geometrical distortion and the amount of misconvergence by the position calculation unit 17 will be described with reference to FIG. Figure 5
(A) is an explanatory view showing a positional relationship between a test pattern and a photodetector in an ideal state in which geometrical distortion and misconvergence do not occur. In this case, the position of the photo-detecting element 31 common to the x direction and the y direction coincides with the apex of the test pattern. On the other hand, FIG. 5B shows the positional relationship between the test pattern displaced due to geometric distortion or misconvergence and the photodetector. By detecting the displacement amounts x ₀ and y ₀ , the geometric distortion and the misconvergence amount can be calculated.

As described above, in order to calculate the geometric distortion and the misconvergence amount with higher accuracy than the output level from the photodetector, the level detection accuracy is an important factor.
In general, photodetectors such as photodiodes and phototransistors have different detection sensitivities. Therefore, unless this correction is performed, highly accurate level detection cannot be performed. Therefore, the minimum value test signal, that is, the minimum level when the test signal is not projected and the maximum level when the maximum value test signal such as the window pattern is projected are measured in advance, and It becomes possible to detect the level with high accuracy by displaying the signal and measuring the level.

The displacements x ₀ and y ₀ of the test pattern are calculated sequentially in the x and y directions. First, the x direction will be described. In this case, as shown in FIG. 4B, a linear chevron pattern in the x direction is used as the test pattern. First, in order to obtain the peak level VR of the test pattern, a window-like pattern having a level equal to the peak level of the linear chevron test pattern as shown in FIG. 6A is generated, and the brightness level VR of this window pattern is calculated. , X-direction, y-direction common photodetector 31
To detect.

Next, as shown in FIG. 6B, a linear chevron-shaped test pattern is generated, and the photodetection element 31 detects the luminance level Vx at that position. Here, the difference output between the photodetectors 31 and 32 from the difference circuit 36 in FIG.
If the distance between the photodetectors 31 and 32 is Δx, the inclination Ax of the test pattern with respect to the x direction is Ax = ΔVx / Δx.
Is required. The displacement amount x ₀ of the test pattern in the x direction due to geometric distortion or misconvergence is obtained by the following equation (2) with the position of the apex of the test pattern being x = 0.

X ₀ = Ax ⁻¹ · (Vx −VR) ... (2) As for the displacement amount y _{0 in the} y direction, as shown in FIG. 6C, a linear chevron-shaped test pattern is used in the y direction. , Y direction inclination of the test pattern Ay (= ΔVy / Δy: the differential output of the photodetector elements 31 and 30 from the difference circuit 37 is ΔVy, and the photodetector elements 31 and 3 are the same.
If the interval of 0 is Δy), the position of the apex of the test pattern is y = 0, and it can be obtained by the following equation (3). ^{_{y 0 = Ay -1 · (Vy}} -VR) ··· (3)

By such a method, the displacement of the position coordinates of the test pattern due to geometric distortion or misconvergence can be detected. Here, the position coordinate detection is described for one test pattern having a linear mountain shape in which the signal level continuously changes, but the operation is the same for other patterns as shown in FIGS. 7D to 7G. Is.

Next, from the coordinates of the test pattern calculated by the position calculating section 17 described above, the error calculating section 18 calculates an error and the correction signal generating circuit 19 creates a correction signal. , FIG. 10 will be described.
FIG. 8A shows an ideal state in which geometric distortion does not occur in the display image. FIG. 8B shows the displacement of the test pattern when, for example, trapezoidal geometric distortion occurs.

In the case of the trapezoidal distortion as shown in FIG. 8B, pay attention to the test patterns 40 and 42 (or the test patterns 45 and 47) corresponding to both ends of the upper side (or the lower side) of the screen. Then, the displacements of the position coordinates of these test patterns from the ideal state are detected by the light detection units 8 and 10 (or the light detection unit 1).
3, 15). If the displacement obtained in the test pattern 40 is Δy ₁ and the displacement obtained in the test pattern 42 is Δy ₂ , the distortion component of the trapezoidal distortion is Δy ₁ + Δy.
Required by ₂ . Based on the geometrical distortion and the convergence error obtained by the error calculation unit 18, the correction signal generation circuit 19 generates a vertical rate sawtooth waveform with a correction amount of Y ₁ + Y _{2 as} shown in FIG. 8C. Generates a waveform that is multiplied by the sawtooth waveform of the rate.

FIG. 9 and FIG. 10 show typical geometric distortions and correction waveforms corresponding thereto. Further, the position coordinates of each of the R, G, and B test patterns at the correction point of interest are obtained by the method described above, and R and B for the G test pattern are obtained.
The amount of misconvergence is obtained from the error in the position coordinates of the test pattern.

Next, the correction signal generating circuit 19 is shown in FIG.
This will be described with reference to FIGS. 1, 12, 13, and 14. Figure 11
3 is a block diagram showing a specific configuration of the correction signal generating circuit 19. FIG. 12 to 13 show various correction waveforms generated by the correction waveform generating circuit 52 of FIG. In FIG. 11, the horizontal synchronizing signal and the vertical synchronizing signal are supplied to the input terminals 50 and 51 of the correction waveform generating circuit 52, respectively.
The correction waveform generating circuit 52 is composed of, for example, a plurality of Miller integrating circuits, and has 12 kinds of basic waveforms (WF1 to W) required for geometric distortion and convergence correction shown in FIGS.
F12) is generated. The correction waveform generation circuit 52 gives a correction waveform synchronized with the input synchronization signal to the reference potential terminals of the multiplication D / A converters (multiplication D / A) 53 to 64.

On the other hand, the correction data of the error calculating section 18 of FIG. 1 is supplied to the serial data creating circuit 65 of FIG.
The serial data creating circuit 65 creates a serial signal as shown in FIG. 15 based on the control signal from the error calculating section 18. As shown in FIG. 15A, an address signal (A3 to A0) and a data signal (D7 to) are included in the serial signal.
D0) is multiplexed. The address signal A selects the multiplication D / A converters 53 to 64, and then the data signal D controls the amplitude of the correction waveform.

Clock signals and load signals of the multiplication D / A converters 53 to 64 are shown in FIGS. 15B and 15C, respectively.
In the multiplication D / A converters 53 to 64, the load signal of FIG. 15C is set to LOW and the clock signal of FIG. 15B is set to input data at the positive edge. The three serial signals shown in FIG. 15 are multiplication type D / A.
The 12 types of basic correction waveforms (WF1 to WF) supplied from the correction waveform generating circuit 52 are supplied to the input terminals of the converters 53 to 64.
The polarity and amplitude of 12) are controlled, and geometric distortion and misconvergence are corrected.

FIG. 14 shows the relationship between the analog correction waveform and the correction change. As shown in the installation position of the light detection unit 8 in FIG. 4, it can be understood that the display positions of the center and the peripheral portion of the screen can be calculated to automatically correct using the correction waveforms of FIGS.

As described above, according to this embodiment, the test pattern in which the signal level changes is detected in the installation direction of the plurality of photodetecting elements, and the display position of the test pattern is determined from the level and inclination of the detection signal. calculate. By doing so, the direction of the image having distortion and the amount of deviation can be directly detected, so that the image distortion of the projected image can be corrected with high accuracy in a short time.

Next, a position detecting device according to a second embodiment of the present invention will be described with reference to the drawings. FIG. 16 shows the second
It is a block diagram which shows the whole structure of the projection type display containing the position detection apparatus of an Example. 16, the same parts as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. The projection type display of this embodiment is the same as that shown in FIG.
The magnifying projection device 24 has the same structure as in FIG.

In FIG. 16, the display position control unit 29 is a circuit for controlling the display position of the test pattern generated by the test pattern generation circuit 1. The photodetection elements 70 to 77 are elements that are arranged at predetermined positions in the peripheral portion of the screen 7 and detect the brightness level of the displayed test pattern.
The peak hold circuit 39 is a circuit that converts the light detection signal output from the multiplexer 16 into a DC signal. A / D
The converter 38 is a circuit for converting the output of the peak hold circuit 39 into digital data, the output of which is the position calculator 17
Given to. Position detecting device 28 configured in this way
Detects the display position of the test pattern projected on the photodetection elements 70 to 77 on the screen 7.

Next, the operation of detecting the position coordinates of the test pattern of this embodiment will be described. Here, the position coordinate detection is described for one test pattern, but the operation is the same for other patterns. First, the test pattern of this embodiment will be described. As shown in FIG. 17A, the test pattern generating circuit 1 is provided at a predetermined position in the overscan area in the peripheral portion of the screen 7 as shown in FIG.
, The test patterns 80 to 87 having a linear mountain-shaped luminance distribution with respect to the horizontal and vertical directions of the display surface.
Occurs. In order for the test pattern displayed on the screen to be linear with respect to the brightness level in this way, gamma correction in the display device is required as described in the first embodiment.

Next, with such a test pattern,
A method of calculating the geometric distortion and the amount of misconvergence will be described with reference to FIG. FIG. 18A is an explanatory diagram of the positional relationship between the test pattern and the photodetector in an ideal state in which geometric distortion and misconvergence do not occur. In this case, the apex of the test pattern is located at the position of the photodetector. On the other hand, FIG. 18B is an explanatory diagram showing the positional relationship between the test pattern displaced due to geometric distortion or misconvergence and the photodetector. Here, by detecting the displacement amounts x ₀ and y ₀ , the geometric distortion and the misconvergence amount can be calculated.

FIG. 19 is a specific block diagram of the position detecting device 28. In the figure, photoelectric conversion signals from the photodetecting elements 70 to 77 are given to the switching circuit 123. Switching circuit 1
Reference numeral 23 is a circuit composed of an analog switch or the like, and selects a signal necessary for calculating coordinates of each position. Switching circuit 12
The signal of low frequency rate from 3 is supplied to the maximum value detection circuit 124 and converted into a DC signal. Maximum value detection circuit 12
The analog DC signal output from 4 is the A / D converter 1
25 and is converted into digital data. This signal is supplied to the coordinate calculation circuit 126 composed of a CPU or the like and converted from a signal level into a coordinate signal. The position coordinate calculation circuit 126 generates a control signal for controlling each position and the detection direction and a control signal for controlling the display position of the test pattern, and outputs the control signal to the switching circuit 123 and the test pattern display position control circuit 127. Supply.

The displacements x ₀ and y ₀ of the test pattern are calculated sequentially in the x and y directions. First, the x direction will be described. In this case, as the test pattern, a linear mountain-shaped test pattern is used in the x direction. First, in order to obtain the peak level VR of the test pattern, FIG.
A window-like pattern having a level equal to the peak level of the linear chevron test pattern is generated as shown in FIG. And the brightness level VR of the window pattern
Is detected by the light detecting element.

Next, as shown in FIG. 20B, the linear mountain-shaped test pattern described above is generated, and the brightness level Vx in this case is detected by the photodetector. Next, the display position control unit 29 moves the display position of the test pattern a minute distance Δx in the x direction. In this case, the output change ΔV of the photodetector is detected and the inclination Ax = ΔV / Δx of the test pattern with respect to the horizontal direction x is obtained. Displacement x in the x direction of the test pattern due to geometric distortion or misconvergence
₀ is obtained by the following equation (4) with the vertex of the test pattern being x = 0. ^{_{x 0 = Ax -1 · (Vx}} -VR) ··· (4)

As shown in FIG. 20C, the displacement amount y ₀ in the y direction is calculated by using a linear mountain-shaped test pattern in the y direction by the same method as in the x direction. That is, the light detection output is Vy, the inclination Ay of the test pattern with respect to the y direction (= ΔVy / Δy: the change amount of the light output when the test pattern is moved by a small distance Δy by the display position controller 29 is ΔVy), the test It is calculated by the following equation (5) with the position of the apex of the pattern being y = 0. ^{_{y 0 = Ay -1 · (Vy}} -VR) ··· (5)

With such a method, the displacement of the position coordinates of the test pattern due to geometric distortion or misconvergence can be detected. After that, the geometrical distortion and the amount of misconvergence are calculated and corrected from the position coordinates of the detected test pattern, but since this is the same processing as in the case of the first embodiment, its explanation is omitted. To do. The shape of the test pattern is the same as the other patterns described in the first embodiment.

Further, by calculating the display position by using the specific shape (level change) test pattern created in advance, position detection can be realized in a short time with a simple structure. Further, as a method of detecting the position with higher accuracy, it is possible to further improve the accuracy by giving the display size of the test pattern displayed on the display screen as setting data in advance.

As described above, according to the present embodiment, the display position is calculated by moving the test pattern in which the signal level changes in the detection direction, so that the direction and the shift amount are directly detected by one photodetector element. it can. Therefore, the position detection can be realized with high accuracy with a simple structure in a short time.

Next, a position detecting device according to a third embodiment of the present invention will be described with reference to the drawings. FIG. 21 shows the third
It is a block diagram which shows the whole structure of the projection type display containing the position detection apparatus of an Example. In FIG. 21, first and second
The same parts as those in the embodiment are designated by the same reference numerals, and detailed description will be omitted.

In the figure, the photodetectors 100 to 107 are arranged at predetermined positions in the peripheral portion of the screen 7, detect the brightness level of the displayed test pattern, and are composed of a plurality of photodetectors. The position calculation unit 78 is a circuit for obtaining the display position coordinates of the test pattern from the light detection signal output from the multiplexer 16. Position detector 69
Is an apparatus for detecting the display position of the test pattern displayed on the light detection units 100 to 107 on the screen 7.

Next, the operation of detecting the position coordinates of the test pattern of this embodiment will be described. As shown in FIG. 22, the test pattern generation circuit 1 generates test patterns 110 to 117 having signal peaks such as cos ² characteristics at predetermined positions in the overscan area outside the effective screen. Here, a test pattern having a cos ² characteristic is used, but if the waveform has a peak, for example, as shown in FIG. 23, when the display surface is the bottom surface and the brightness level direction is the height direction, a quadrangular pyramid is used. It may be a test pattern having a shape. It is also effective for a test pattern such as a cross hatch.

Next, the position coordinate detecting operation of the test pattern generated in the test pattern generating circuit 1 will be described in detail with reference to FIGS. 24 and 25. Here, the position coordinate detection is described for one test pattern, but the operation is the same for other test patterns. FIG. 24 is a configuration diagram of the light detection units 100 to 107, and FIG.
6 is a concrete block diagram of a position detecting device 69 for detecting pattern coordinates. FIG.

In FIG. 24, the photodetectors a to i are, for example, photodetectors such as photodiodes and phototransistors arranged in a matrix. In this embodiment, each of the nine photodetector elements a to i is the central photodetector element e.
Are used as reference coordinates and are arranged in a grid pattern with respect to horizontal (x direction) and vertical (y direction) coordinates on the display surface. The coordinates of each detection element in these arrangements are a (-1,
1), b (0,1), c (1,1), d (-1,0),
e (0,0), f (1,0), g (-1, -1), h
(0, -1) and i (1, -1).

In the present embodiment, as shown in FIG. 26A, a dot-shaped test pattern is used, and the position of this pattern is calculated by the photodetection sections arranged in a lattice by nine photodetection elements. . For example, as shown in FIGS. 27C to 27F, a linear test pattern is used, and the position of this pattern is L-shaped as shown in FIGS. 27C and 27D, or (e).
Calculation may be performed using photodetection elements arranged in a lattice pattern, such as the cross shape shown in FIG. 26 and 27
In the figure, only the test pattern in the horizontal direction is shown, but the test pattern in the vertical direction is similar to that in the horizontal direction. Moreover, although the xy coordinates are assigned as described above for the sake of simplicity, the assignment method of the coordinates may be another assignment method as long as it is suitable for the arrangement of the photodetecting elements.

In FIG. 25, the peak hold circuit 19
Reference numerals 0 to 198 denote photodetector elements a arranged at predetermined positions on the periphery of the screen 7 selected by the multiplexer 16.
It is a circuit which detects the peak of each signal output of ~ i. A /
The D converters 199-207 are peak hold circuits 190-190.
This circuit converts the output of 198 into digital data. The adder 208 is a circuit that adds all the digital data output from the A / D converters 199 to 207. The dividers 209 to 217 are circuits that find the ratio of the output of each photodetector a to i to the output of the adder 208. The coordinate conversion table 218 is a circuit for obtaining the display position coordinates (x, y) of the test pattern from the outputs of the dividers 209 to 217.

The coordinate conversion table 218 is used in the divider 209.
Output respectively Z _A Z _B of ～217 ..., When Z _I, and outputs the value to be converted by the following equation (6).

[Equation 4]

This conversion formula will be described using a specific example. For example, when the test pattern is displayed at the intersection of the arrangements of the photodetecting elements a, b, d, and e as shown in FIG. 26A, the outputs of these photodetecting elements become equal to each other, and the other photodetecting elements are output. Output is zero. In this case, the photodetector a,
dividers 209, 210, 212 corresponding to b, d, e,
The outputs Z _A , Z _B , Z _D , and Z _E of 213 are 0.25, respectively, as shown in FIG. Substituting this into the coordinate conversion table of equation (6) gives the following equation (7).

(Equation 5) From the above equation, the display position coordinates of the test pattern are (x,
y) = (− 0.5, 0.5) is calculated.

As described above, the photo-detecting elements are arranged in a grid (matrix), coordinates on the display screen are assigned to these photo-detecting elements, and the photo-detecting elements arranged in the matrix form a ratio to the total output. The display position of the test pattern in the photodetector can be directly calculated by weighting and adding the coordinates assigned to each photodetector.

Therefore, the displacement of the position coordinates of the test pattern due to geometrical distortion or misconvergence can be detected from the display position. The geometrical distortion and the amount of misconvergence are calculated and corrected from the detected position coordinates of the test pattern, but this is the same processing as in the case of the first embodiment, and a description thereof will be omitted. In this embodiment, the photodetector elements are arranged in a grid pattern (matrix pattern) in the horizontal and vertical directions, and the position coordinates in the horizontal and vertical directions are simultaneously detected. Coordinates can also be detected.

As described above, according to this embodiment, a plurality of photodetecting elements are arranged at predetermined positions, and the coordinates on the display screen are assigned to these photodetecting elements. Then, the display position of the test pattern in the photodetector is directly calculated by weighting and adding the coordinates assigned to each photodetector by the ratio of each output of each photodetector to the total output of each photodetector. be able to. Therefore, it is possible to perform highly accurate automatic adjustment in a short time.

Next, an image correction apparatus as a fourth embodiment of the present invention will be described with reference to the drawings. FIG. 28 is a block diagram showing the overall configuration of a projection display including an image correction device. 28, the same parts as those in the first to fourth embodiments are designated by the same reference numerals, and detailed description thereof will be omitted. In this figure, the image correction device is configured to include a magnifying projection device 24, an automatic adjustment device 25, and light detection units 8 to 15.

The image correction device is a device for automatically adjusting geometrical distortion and convergence in a projection display and outputting a video without image distortion. Similar to the first embodiment, the magnifying projection device 24 includes a switching circuit 2, a video circuit 3, a CRT for R, B, G 4, a lens 5, a convergence correction circuit 20, and a deflection circuit 21. The automatic adjusting device 25 is different from the first embodiment in that the multiplexer 1
6, an error calculator 18, a correction signal generator 19, a test pattern generator 79, and a position calculator 88.

The test pattern generation circuit 79 is a circuit for sequentially generating test patterns for position detection and error detection. The photodetectors 8 to 15 are arranged at predetermined positions on the periphery of the screen 7, detect the brightness level of the displayed test pattern, and are composed of a plurality of photodetectors. The position calculation unit 88 is a circuit that obtains the display position coordinates of the test pattern from the light detection signal output via the multiplexer 16.

The operation of the image correction apparatus thus configured will be described. FIG. 29 is an explanatory diagram showing a test pattern and a position detection method in each adjustment mode. First, a case where a rough position detection of a test pattern is performed will be described. This position detecting method is the same as the detecting method described in FIG. 5 of the first embodiment, as shown in FIG. That is, a large test pattern 98 whose brightness level changes is displayed, and the rough direction and shift amount of the test pattern are detected.
Performs convergence by rough adjustment. Since this converging operation is the same as that of the first embodiment, its explanation is omitted.

Next, error detection for convergence of fine adjustment will be described. As shown in FIG. 29 (b), the error detection method is a small test pattern 99 such as a crosshatch signal.
Is displayed, a minute amount of positional deviation of the test pattern is detected, and the fine adjustment operation is converged. Table 1 shows a comparison of each adjustment mode.

[Table 1]

In order to explain the error detecting operation in detail, the block diagram of FIG. 30, the operation waveform diagram of FIG. 31, and the operation characteristic diagram of FIG. 32 are used. FIG. 30 is a block diagram showing a specific configuration of the position calculation unit 88. The photodetection elements 30 to 31 forming a part of the photodetection section 8 are composed of a plurality of photoelectric conversion elements such as photodiodes and phototransistors. The subtractor subtracts the photoelectric conversion signal from the photodetection conversion element 31 (S1) to the left of the reference position X ₀ and the photoelectric conversion signal from the photodetection element 32 (S2) to the right of the reference position X ₀ . It is supplied to 160 and subtracted.

When the test pattern is located at the reference position X ₀ of the photodetecting section 8, the signals from the photodetecting elements 30 and 31 have waveforms with the same amplitude as shown in FIGS. 31 (a) and 31 (b). In this case, the output from the subtractor 160 is shown in FIG.
As shown in, the voltage becomes 0 (V). When the light received by the photodetector elements 31 and 32 moves in the direction of arrow P as shown in FIG. 30, the photoelectric conversion signal also changes in signal amplitude in the direction of arrow as shown in FIGS. 31 (a) and 31 (b). To do. Therefore, as shown in FIG. 31D, the output from the subtractor 160 changes its polarity depending on the position shift direction with reference to the reference position X ₀ of the photodetecting element, and changes the signal amplitude depending on the position shift amount.

A signal including this position information is supplied to the maximum value detection circuit 161 and the minimum value detection circuit 162 of FIG.
Maximum and minimum values are detected. By adding the maximum value and the minimum value of this DC potential in the adder 163, the DC potential corresponding to the position shift direction and the position shift amount is output from the adder 163. Therefore, the output from the adder 163 becomes a voltage 0 (V) as shown in FIG. 31 (e) when the test pattern is located on the reference position X _{0 of the} photodetector. Further, when the test pattern moves upward (direction of arrow P), the voltage becomes + V1 (V) as shown in FIG. 31 (f), and when the test pattern moves downward, FIG. ), The voltage becomes -V2 (V).

FIG. 32 is a characteristic diagram of the output of the adder 163 with respect to the positions on the photodetectors 30 to 31. As shown in this figure, a signal including position information is obtained when the reference position X0 of the photodetector is set to a voltage of 0 (V). In FIG. 30, the output of the adder 163 is supplied to the comparator 164, and the error detection signal is output so as to converge to 0V which is the convergence potential of the reference position. Here, the case has been described where the error detection is performed only in the horizontal direction on the screen cross. Since the error detection of other positions and directions is performed in the same manner, the description thereof will be omitted.

By such a method, the error value of the test pattern due to geometric distortion or misconvergence can be detected. Next, the geometrical distortion and the amount of misconvergence are calculated and corrected from the detected position coordinates of the test pattern, but since this is the same processing as in the case of the first embodiment, its explanation is omitted. In this way, using the test patterns for position detection (for signal search) and error detection, the display position is calculated and corrected by detecting the direction and error. Therefore, it is possible to perform highly accurate correction in a short time with a simple configuration. Further, since the reference point has a convergence point, it is possible to correct the screen phase.

Next, an image correction apparatus according to the fifth embodiment of the present invention will be described with reference to the drawings. FIG. 33 is a block diagram showing the overall configuration of a projection type display including an image correction device. In this figure, the same parts as those in the fourth embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

The test pattern generation circuit 1 of FIG. 33 is a circuit for sequentially generating a test pattern such as a crosshatch signal for position detection. The photodetectors 170 to 177 are arranged at predetermined positions on the periphery of the screen 7, detect the brightness level of the displayed test pattern, and are composed of a plurality of photodetectors. The position calculation unit 89 is a circuit that obtains the display position coordinates of the test pattern from the light detection signal output from the multiplexer 16.

First, the photodetectors 170 to 177 and test patterns 150 to 177 arranged at predetermined positions on the periphery of the display screen.
157 will be described in detail with reference to FIG. Photodetectors 132, 133, 142, 143, 136, 13
Reference numerals 7, 138 and 139 are elements arranged on the screen cross of the screen 7 along each scanning direction. Further, the photodetector elements 130, 131, 134, 135, 140, 141,
Elements 144 and 145 are elements arranged in the peripheral portions of the four corners on the screen 7 in an oblique direction with respect to each scanning direction. These photodetection elements are composed of photodiodes, phototransistors, or the like.

The test patterns displayed on the photo-detecting elements are vertical line hatch signals for the upper and lower patterns on the screen cross, horizontal line hatch signals for the left and right patterns on the screen cross, and vertical and horizontal line hatches for the four corners. The signals are sequentially displayed, and the position of the test pattern is detected. First, the operation of detecting the position coordinates of the test pattern will be described. As the position detection mode, as shown in FIG.
It can be roughly classified into modes for detecting the positions of the four corners. The basic operation of detecting the position on the cross of the screen is the same as the detection method described in the fourth embodiment, and the convergence operation in that case is the same as in the first embodiment.

The position detection method in each detection mode is shown in FIG.
5 shows. FIG. 35 (a) is a top and bottom of the screen cross, and FIG.
(B) shows the relationship between the left and right on the cross of the screen, and (c) and (d) of FIG. 35 show the relationship between the photo-detecting elements in the four corners and the test pattern. FIG. 35E shows, as the position detection signal, the amount of positional deviation with respect to the reference position at the center of the two photodetection elements set in advance in each detection region, as described in the fourth embodiment.

FIG. 36 and FIG. 37 are convergence operation diagrams for detecting the positions of the four corner peripheral portions. FIG. 36A shows a convergence point when the photodetector elements (S3, S4) are installed along the conventional scanning direction, and it can be seen that the reference position of the test pattern is concentrated at one point indicated by a black circle. FIG. 36B shows a case where the photodetector elements (S3, S4) are installed obliquely with respect to the scanning direction, and the reference position of the convergence point is shown by a black line in FIG.
It can be seen that there are convergence points in a wider range than in 6 (a). Therefore, in FIG. 36A, the test pattern of the vertical line converges on one convergence point, but as shown by the broken line or the one-dotted line, a position deviation error occurs as the distance from the convergence point increases.

Further, as shown in FIG. 36 (c) due to the aberration of the projection optical system, the deformation of the beam spot diameter, etc., even if one dot of the test pattern is deformed (broken line), the position can be detected with high accuracy. realizable. Figure 37 (a)
As shown in, when a detection element is provided in the peripheral portion on the upper right of the screen, the convergence point is one each in the horizontal / vertical direction (black circle).
On the other hand, in FIG. 37B, since the convergence point exists in a wide range in both the horizontal and vertical directions, highly accurate correction can be realized. Further, although the photodetector element in the shaded area shown in FIG. 37 (b) is not related to the converging operation, the photodetector element can be effectively used by using it as a signal search sensor.

In addition, since the amount of correction of convergence and the like becomes maximum in the peripheral portions of the four corners, if the correction amount is set to an excessively large amount, clogging of the coil drive system will occur and misconvergence will occur. Is very important to correct. From the above, highly accurate correction can be realized by disposing the photodetecting elements in the peripheral portions of the four corners obliquely with respect to the scanning direction.

By such a method, the error value of the test pattern due to geometric distortion or misconvergence can be detected. The geometrical distortion and the amount of misconvergence are calculated and corrected from the position coordinates of the detected test pattern, but this is the same processing as in the case of the first embodiment, and the description thereof is omitted. In this way, a plurality of photodetector elements are installed on the screen cross at right angles to each scanning direction and at the four corners diagonally to each scanning direction, and the display position of the test pattern is calculated to calculate the geometric distortion. Stable and highly accurate automatic adjustment can be achieved by correcting the convergence and convergence.

Next, an image correction apparatus according to the sixth embodiment of the present invention will be described with reference to the drawings. FIG. 38 is a block diagram showing the overall configuration of a projection type display including an image correction device. In this figure, the same parts as those in the fourth embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

In this figure, the test pattern generation circuit 1
Is a circuit for sequentially generating a test pattern such as a crosshatch signal for position detection. Photodetector 170-1
Reference numeral 77 is arranged at a predetermined position in the peripheral portion of the screen 7, detects the brightness level of the displayed test pattern, and is composed of a plurality of photodetection elements. Photodetector 170,
172, 175, 177 are provided at the four corners of the display screen,
A plurality of photodetector elements are arranged obliquely with respect to the horizontal and vertical directions of the image. The photodetectors 171 and 176 are the outer peripheral parts of the long sides of the display screen, and have a plurality of photodetectors arranged in the horizontal scanning direction. Photodetector 173,
Reference numeral 174 denotes an outer peripheral portion of the short side of the display screen, in which a plurality of photodetection elements are arranged in the vertical scanning direction.

The addition / subtraction processing unit 108 is a circuit for adding and subtracting each photoelectric conversion signal of a plurality of photodetecting elements, and the output thereof is given to the position calculating unit 89. The position calculation unit 89 is a circuit that obtains the display position coordinates of the test pattern from the signal of the addition / subtraction processing unit 108. It should be noted that each of the photodetectors 170 to 177 arranged at a predetermined position on the peripheral portion of the display screen, the test pattern, and the position detection method of the test pattern are the fifth.
The description is omitted because it is similar to the embodiment.

Here, a method of calculating the position and the error from the signals obtained by adding and subtracting the signals of the plurality of photodetecting elements will be described. FIG. 39 shows a photodetector 170 including photodetectors 132 and 133, an addition / subtraction processor 108, and a position calculator 8.
9 is a configuration diagram showing the connection relationship of the error calculation unit 18. FIG. 40 is an operation waveform diagram of FIG. 39. The photodetection conversion element 132 in the upward direction with respect to the reference position X ₀ on the upper portion of the screen cross
The photoelectric conversion signal from (S3) and the photoelectric conversion signal from the photodetector element 133 (S4) in the downward direction with respect to the reference position X ₀ are supplied to the adder 163 and the subtractor 160, respectively, where they are subjected to addition / subtraction processing.

40 (a) to 40 (d), the photodetector element S3 is shown.
The relative relationship between S4 and the test pattern is shown. Figure 40 (a)
(C) shows a case where the test pattern can receive light on the photodetector, and FIG. 40D shows a state where the test pattern cannot receive light on the photodetector. That is, it means that if the test pattern is received on the photodetection element, the photoelectric conversion signal is output from the photodetection element. The subtracted signal from the subtractor 160 is supplied to the peak hold circuit 165, and the low frequency rate waveform is converted into a DC signal.

As shown in FIG. 40E, the reference position X ₀ of the detection element is set to the reference voltage 0 V, and the position shift direction
The polarity of the position detection signal output by the subtractor 163 changes,
The displacement direction and the displacement amount are detected. Also adder 1
The addition signal from 63 is supplied to the binarization circuit 166 and binarized. This binarized signal is shown in FIG.
In this way, when the test pattern is received on the detection element, the detection voltage is generated and the position detection signal is output.

From the peak hold circuit 165 to FIG.
The position detection signal of (e) is output, the binarization circuit 166 outputs the position detection signal of FIG. 40 (f), and these signals are switched by a switching circuit 167 including an analog switch or the like.
Is supplied to. In this way, the switching circuit 167 selects signals necessary for position detection and error detection. The analog DC signal of the switching circuit 167 is supplied to the A / D converter 168 and converted into digital data. This signal is supplied to the position detection error detection circuit 169 composed of a CPU,
The position coordinates are calculated from the signal level, and the error calculation signal is output. This error calculation signal is processed so as to converge to 0V which is the convergence potential of the reference position.

The position detection signal obtained by the addition process shown in FIG. 40F is for position detection for signal search, and the position detection signal obtained by the subtraction process shown in FIG. 40E is for error detection for convergence. Then used. In the description of the operation, the case where the photodetector elements are arranged as shown in FIG. 34 has been described. By doing so, the position and the error can be detected with higher accuracy. Further, since the position detection of other positions and directions is performed in the same manner, description thereof will be omitted.

By such a method, the error value of the test pattern due to geometric distortion or misconvergence can be detected. The geometrical distortion and the amount of misconvergence are calculated and corrected from the detected position coordinates of the test pattern, but this is the same processing as in the first embodiment, and the description thereof is omitted. In this way, the direction and generation position of the test pattern are controlled by the signal obtained by adding the detection signals from a plurality of photodetectors, and the error is calculated by the signal obtained by subtracting the detection signals from the detector elements, and the geometrical pattern is calculated. Corrects distortion and convergence. Since this method has little influence of unnecessary light, stable and highly accurate automatic adjustment can be realized.

Next, an image correction apparatus according to the seventh embodiment of the present invention will be described with reference to the drawings. FIG. 42 is a block diagram showing the overall configuration of a projection type display including an image correction device. In this figure, the same parts as those in the fifth embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

In this figure, the test pattern generation circuit 1
Is a circuit for sequentially generating a test pattern such as a crosshatch signal for position detection. Photodetector 170-1
Reference numeral 77 is arranged at a predetermined position in the peripheral portion of the screen 7, detects the brightness level of the displayed test pattern, and is composed of a plurality of photodetection elements. The position calculation unit 89 is a circuit that obtains the display position coordinates of the test pattern from the light detection signal output from the multiplexer 16, and its output is given to the error calculation unit 118. The error calculation unit 118 is a circuit that calculates an error value from the signal of the position calculation unit 89. The correction signal generation circuit 119 is a circuit that generates correction signals for the peripheral portion of the screen and the entire screen from the error value of the error calculation unit 118. The photodetectors 170 to 177 arranged at predetermined positions on the periphery of the display screen, the test pattern, and the method for detecting the position of the test pattern are the same as those in the fifth embodiment, and thus the description thereof is omitted.

Here, the method of calculating the position and the error from the signals of the plurality of photodetector elements constituting the photodetector will be described. FIG. 43 is a block diagram showing a specific connection relationship between the photodetectors 170 to 177, the position calculator 89, the error calculator 118, and the correction signal generation circuit 119. Also in FIG.
Is a layout view of the photo-detecting elements, and FIG. 45 is an operation waveform diagram of FIG. 43. As shown in FIG. 44, in the photodetection elements 130 to 145 installed in each detection area, the photodetection conversion elements S3 and S4 symmetrically installed with respect to the reference position are a set of photodetection units. The photoelectric conversion signals output from the eight photo detectors 170 to 177 are given to subtraction circuits 180 to 181, and a subtraction process between the two photo detection elements is performed. The signal is a switching circuit 18 composed of analog switches and the like.
2, and the signals required for position detection and error detection are selected.

The output of the switching circuit 182 is supplied to the peak hold circuit 183, and the low frequency rate waveform is converted into a DC signal. As described above, this converted signal becomes a position detection signal in which the reference position of the photodetector is set to 0V and the polarity changes depending on the direction of the position shift, and the signal amplitude changes depending on the amount of position shift. The analog DC signal from the peak hold circuit 183 is supplied to the A / D converter 184 and converted into digital data. This signal is supplied to an error detection circuit 185 composed of a CPU or the like, position coordinates are calculated from the signal level, and an error calculation signal is output.

The error detection signal is obtained so that this error calculation signal converges to 0V which is the convergence potential of the reference position.
The error detection signal from the error detection circuit 185 is supplied to the correction signal creation circuit 186, and a correction signal for controlling the horizontal amplitude as shown in FIG. 45A is created. The correction signal of the correction signal generation circuit 186 is supplied to the switching circuit 187, the correction signal of only the effective display area is removed by the blanking signal (BLK) signal, and the correction signal of only the peripheral portion of the screen shown in FIG. Is output. The peripheral portion correction signal from which the correction waveform of the effective display area has been removed is supplied to the drive circuit 188 to drive the convergence yoke CY22 to perform the convergence operation only in the peripheral portion of the screen shown in FIG.

As a result, when the convergence operation of the peripheral portion of the screen, which is the detection area, is completed, the switching circuits 182 and 187 are controlled based on the control signal from the error detection circuit 185, and the operation shown in FIG.
The correction signal for the full screen shown in 5 (c) is output, the correction is performed for the full screen, and the convergence operation for the full screen is completed.
In FIG. 45B, the case where a horizontal sawtooth waveform for controlling the amplitude in the horizontal direction is used has been described.
As shown in (d), it is also possible to create a correction signal of the DC potential and perform the focusing operation only in the peripheral portion.

In general, the band (cut-off frequency) of the drive system including the drive circuit 188 and the CY22 having an inductance value of several tens of μH is about several hundred kHz, and therefore, in actuality, as shown in FIG.
It is difficult to have a steep rise / fall characteristic as shown in (c) and (d), but by controlling the generation timing of the correction signal as shown in FIG. The peripheral part can be corrected without disturbing the image. FIG. 46 shows the adjustment order.

First, the photodetectors 132, 133 (upper), 142, 143 on the cross of the screen shown in FIG.
(Bottom), 136, 137 (left), 138, 139 (right)
Error patterns are detected by projecting a test pattern such as a crosshatch signal at four positions, and the static, linearity, size, skew, and
Convergence operation of the peripheral part is performed in the baud adjustment item. When the convergence operation of the peripheral part is completed, the convergence operation of the entire screen is performed.

Next, at four locations around the four corners of the screen shown in FIG. 44, the photodetectors 130, 131 (upper left), 134, 135 (upper right), 140, 141 (lower left), 144, 145 (lower right). , A test pattern such as a crosshatch signal is displayed to detect an error value. Then, the trapezoidal distortion, the pincushion, and the four corner independent adjustment items as shown in FIG. When this convergence operation is completed, the convergence operation for the entire screen is performed, and all adjustments are completed.

Here, the correction signal generation circuit 119 has both functions of a peripheral part correction signal creating means for creating a correction signal only for the screen peripheral part and a full screen correction signal creating means for creating a full screen correction signal. are doing. In this way, first, after completing the focusing operation of only the detection area of the photo-detecting elements installed in the peripheral area of the screen, then performing the focusing operation of the entire screen to correct the geometric distortion and convergence. Thus, stable and highly accurate automatic adjustment can be realized without disturbing the image on the effective screen.

Next, an image correction apparatus according to the eighth embodiment of the present invention will be described with reference to the drawings. FIG. 47 is a block diagram showing the overall configuration of a projection type display including an image correction device. In this figure, the same parts as those in the fourth embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

In this figure, the test pattern generating circuit 1
Is a circuit for sequentially generating a test pattern such as a crosshatch signal for position detection. Photodetector 170-1
Reference numeral 77 is arranged at a predetermined position in the peripheral portion of the screen 7, detects the brightness level of the displayed test pattern, and is composed of a plurality of photodetection elements. The position calculation unit 89 is a circuit that obtains the display position coordinates of the test pattern from the light detection signal output from the multiplexer 16. The error calculator 18 is a circuit that calculates an error value from the signal of the position calculator 89.

The temperature detecting circuit 146 is a circuit for detecting the temperature inside the magnifying projection device 24. The timer circuit 147 is a circuit for measuring the elapsed time from the power-on of the magnifying projection device 24. The correction signal generation circuit 148 includes an error calculation unit 18,
It is a circuit that generates a correction signal from signals from the temperature detection circuit 146 and the timer circuit 147. In addition, each of the light detection units 170 to 17 arranged at a predetermined position on the periphery of the display screen.
7, the test pattern and the method of detecting the position of the test pattern are the same as those in the fifth embodiment, and the description thereof will be omitted.

Here, a method of generating a correction signal based on the error value from the error calculation section 18 will be described depending on the elapsed time or the ambient temperature. FIG. 48 shows the light detectors 170-.
17 is a block diagram showing a connection relationship among a 177, a position calculation unit 89, an error calculation unit 18, and a correction signal generation circuit 148. FIG. Further, FIG. 49 is an operation waveform diagram of FIG. In the photodetector elements 130 to 145 installed in the respective detection areas as shown in FIG. 44, the photodetector conversion elements (S3 and S4) with respect to the reference position.
Are installed symmetrically. The outputs of the photo-detecting section composed of two photo-detecting elements are given to the subtraction circuits 180 to 181, respectively. Eight types of photoelectric conversion signals are subtracted from the subtraction circuit 180-
After the subtraction processing is performed in 181, it is supplied to the switching circuit 182 composed of an analog switch or the like. The switching circuit 182 selects a signal required for position detection and error detection.

The output of the switching circuit 182 is supplied to the peak hold circuit 183, and the low frequency rate waveform is converted into a DC signal. As described above, the converted signal is a position detection signal in which the reference position of the photo-detecting element is set to the reference voltage of 0 V, the polarity changes depending on the position shift direction, and the signal amplitude changes depending on the position shift amount. The analog DC signal of the peak hold circuit 183 is supplied to the A / D converter 184 and converted into digital data. This signal is supplied to an error detection circuit 185 composed of a CPU or the like, position coordinates are calculated from the signal level, and an error calculation signal is output. This error calculation signal is the amount of positional deviation with respect to the reference position for each lapse of time, as shown in FIG. The error calculation signal from the error detection circuit 185 is the correction signal creation circuit 18
9 and a correction signal for each lapse of time is created as shown in FIG.

Further, the correction signal generating circuit 189 is supplied with a temperature detection signal from the temperature detection circuit 146 for detecting the temperature inside the set and a detection signal from the timer circuit 147 for detecting the time after power-on of the set. There is. The correction signal generating circuit 189 detects the position information of the test pattern to generate a correction signal when the test pattern is projected on the photodetector, but FIG. 49A of the temperature detection circuit 146 and the positional deviation characteristic with respect to the reference position for each elapsed time shown in FIG.
From the temperature characteristics shown in FIG. 49C, optimum correction signals close to the correction characteristics shown in FIG. 49B are sequentially created.

This means that when the projection type display is installed and adjusted, if the amount of positional deviation with respect to the passage of time is detected once in advance, the test pattern is not projected on the photodetector thereafter. This means that drift-forward control can automatically perform drift correction. Further, as shown in white circles (circle) in FIG. 49 (d), a test pattern is periodically projected on the photodetector to confirm the convergence state of the positional deviation amount, and if the positional deviation occurs, the feedback control is converged. It is also possible to take action.

If the test pattern is always projected on the photodetector and feedback control is performed, the correction can always be made.
Since the malfunction occurs due to the influence of unnecessary light such as indoor lighting and the deformation of the set body, the convergence operation is performed periodically as described above. With such a method, the error value of the test pattern due to geometric distortion or misconvergence can be detected. Then, the geometrical distortion and the amount of misconvergence are calculated and corrected from the detected position coordinates of the test pattern, but this is the same processing as in the case of the first embodiment, and a description thereof will be omitted.

As described above, by detecting the amount of positional deviation for each lapse of time from the test pattern displayed on the photodetection element and creating a correction signal by this detection signal and the detection signal from the photodetection element, Stable and highly accurate drift correction can be realized without constant detection.

Next, an image correction apparatus according to the ninth embodiment of the present invention will be described with reference to the drawings. FIG. 50 is a block diagram showing the overall configuration of a projection display including an image correction device. In this figure, the same parts as those in the fourth embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

In this figure, the test pattern generation circuit 2
A circuit 22 sequentially generates a test pattern such as a crosshatch signal for position detection. Photodetector 170
~ 177 is arranged at a predetermined position on the periphery of the screen,
It detects the brightness level of the displayed test pattern and is composed of a plurality of photodetection elements. Position calculation unit 220
Is a circuit for obtaining the display position coordinates of the test pattern by changing the time / voltage conversion characteristic corresponding to the light receiving position from the light detection signal output from the multiplexer 16. The error calculation unit 221 is a circuit that calculates an error value from the signal from the position calculation unit 220, and its output is a correction signal generation circuit 119.
Given to.

Here, a position calculation method for obtaining the display position coordinates of the test pattern by changing the position / voltage conversion characteristic will be described. FIG. 51 shows photodetectors 170-177.
3 is a circuit diagram showing a specific configuration of a position calculation section 220. FIG. Further, FIG. 52 is an operation characteristic diagram of the position calculation unit 220. In this embodiment, the positional deviation from the reference position is detected, and the test pattern is controlled so that the test pattern is always located at the reference position. Therefore, the detection sensitivity near the reference position is greatly affected by the detection accuracy. . Therefore, in the case of signal detection and error detection, the position / voltage conversion characteristic with respect to the light receiving position is changed to realize high-speed signal search and highly accurate error detection.

In FIG. 51, arithmetic units 243 and 244 are adders composed of operational amplifiers (op amps) 260 and 261, and arithmetic unit 245 is a subtracter composed of operational amplifier 262. Generally, the output voltages of the computing units 243 and 244 are represented by the following equations (8) and (9). The output voltage E01 of the operational amplifier 260 is E01 =-(Rf / R1 * E1 + Rf / R2 * E2) (8) The output voltage E02 of the operational amplifier 261 is E02 =-(Rf / R2 * E3 + Rf / R1 * E4) (9)

The output voltage of the computing unit 245 is the following (1
0) formula (provided that R3 = R4 and R5 = R6). E03 = R5 / R3 × (E01−E02) (10)

The photodetector S2 adjacent to the reference position X ₀
The photoelectric conversion signal from S3 is supplied to the operational amplifiers 260 and 261 through the resistor R2. Further, the photoelectric conversion signals from the photoelectric conversion elements S1 and S4 which are away from the reference position are the resistance R
It is supplied to the operational amplifiers 260 and 261 through 1. Photodetector elements (S1, S2) located above the reference position
Are supplied to the operational amplifier 260, and the photodetector elements (S3, S4) located below the reference position are operated by the operational amplifier 261.
To be added to each. At this time, by setting the resistance values of the resistors R1 and R2 so that R1> R2, the detection sensitivity in the vicinity of the reference position can be increased.

The operational amplifiers 260 and 261 output signals in which the detection sensitivity of the photodetector elements S2 and S3 adjacent to the reference position is increased. The signal from the operational amplifier 260 is supplied to the negative terminal of the operational amplifier 262, and the signal from the operational amplifier 261 is supplied to the positive terminal of the operational amplifier 262 to be subtracted. Then, as shown in FIG. 53A, the reference position is set as the convergence point, and a non-linear position detection signal with increased detection sensitivity in the vicinity of the reference position is output. Also, resistors R1 and R
By setting the resistance value of 2 such that R2> R1, a linear position detection signal with a wide detection range is output as shown in FIG. 53 (b).

In the signal search, the linear characteristic of FIG. 53 (b) in which the convergence direction and the approximate error value can be directly calculated is used. In the final error detection and convergence operation, the error can be detected in the vicinity of the reference position with high accuracy. Position detection is performed using the non-linear characteristic of 53 (a). Subsequent processing is the same as that described above, and the maximum and minimum values of the signal are detected, and both detection signals are added to perform position detection. Therefore, if the output characteristics from the adder are shown corresponding to the position on the photodetector,
As shown in FIG. 53, a position / voltage converted conversion signal for the light receiving position is obtained.

As described above, the conversion characteristics are controlled by controlling the detection sensitivity of the reference position by changing the addition ratio in the arithmetic units 243 and 244. Can be done.

Next, the relationship between the test pattern signal and the position calculation method will be described with reference to FIG. FIG. 53 is an explanatory diagram showing the relationship between the test pattern and the position detectability. First, a signal search is performed. With the narrow crosshatch signal shown in FIG. 53B, position detection cannot be performed unless the test pattern exists within the light receiving range of the photodetector. Therefore, for signal search, the crosshatch signal shown in FIG. 53 (c) which is as wide as possible is advantageous.
This test pattern is subjected to position calculation of the linear characteristic shown in FIG. 53A to detect the convergence direction and an approximate error value.

Next, in order to detect an error, the narrow crosshatch signal shown in FIG. 53 (e) is projected, and the error near the reference position is detected with high accuracy by the position calculation of the nonlinear characteristic shown in FIG. 53 (a). are doing. In the case of error detection near the reference position, FIG.
Using the wide crosshatch signal shown in FIG.
When position detection is performed with the non-linear characteristic of 3 (a), high-accuracy error detection is impossible because there are portions with high detection sensitivity on both sides.

As described above, during signal search, a large test pattern is displayed and position detection is performed using a position / voltage conversion signal having a linear characteristic. When error is detected, a small test pattern is displayed and a nonlinear characteristic is displayed. Error detection is performed using the position / voltage conversion signal. This enables high-speed signal search and highly accurate error detection. Note that FIG. 53 (f) shows the photodetector elements (S1 to S
4) The states of the wide test pattern and the narrow test pattern shown above are shown.

With such a method, the error value of the test pattern due to geometric distortion or misconvergence can be detected. And from the position coordinates of the detected test pattern,
Geometric distortion and misconvergence amount are calculated and corrected, but this is the same process as in the first embodiment, and the description thereof is omitted. In this way, by controlling the position / voltage conversion characteristics that perform position detection using the position detection (signal search) pattern and the error detection pattern, and performing position detection, high-precision correction can be realized in a short time. it can.

A position detecting apparatus according to the tenth embodiment of the present invention will be described with reference to the drawings. FIG. 54 is a block diagram showing the overall construction of a projection type display including the position detecting device of the tenth embodiment. In this figure, the same parts as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. Figure 5
The test pattern generation circuit 600 of No. 4 is a circuit for generating a test pattern for geometric distortion and convergence adjustment, and the test pattern is given to the switching circuit 2.

The photo detectors 601 to 608 are a group of photo detectors provided in the overscan area of the display screen. The photo detectors 602, 604, 605, 607 are arranged on the cross of the screen 7, and the photo detectors 601, 603,
606 and 608 are arranged at the corners of the screen 7. These photodetectors detect the geometric distortion and the brightness level of the convergence adjustment test pattern displayed in the overscan area. The multiplexer 609 is a circuit that selects the outputs of the photodetectors 601 to 608. The position calculation unit 610 is a circuit that calculates the display position of the test pattern from the outputs of the light detection units 601 to 608 selected by the multiplexer 609.

FIG. 55 is a specific block diagram of the photodetectors 601 to 608. Here, since the photodetection units 601 to 608 have the same configuration, respectively, one of them, the photodetection unit 601.
Will be described. In the figure, the photodetector 620,
Reference numeral 621 denotes a photoelectric element such as a photodiode or a phototransistor, which is arranged obliquely with respect to the horizontal scanning direction x and the vertical scanning direction y of the display device. In this figure, two photodetection elements are provided to simplify the description.
It is effective if the number of light detecting elements is two or more.

FIG. 56 is a block diagram showing a specific structure of the position calculation unit 610. In this figure, peak hold (PH) circuits 622 and 623 are multiplexers 609.
It is a circuit for converting the outputs Z _n and Z _{n + 1} of each photodetector selected by the above into a DC signal. A / D converters 624, 6
Reference numeral 25 is a circuit for converting the outputs of the peak hold circuits 622 and 623 into digital data. Coefficient ROM 62
Reference numerals 6 and 627 denote circuits for multiplying the outputs of the A / D converters 624 and 625 by a built-in coefficient. First adder 62
8 is a circuit for adding the outputs of the coefficient ROMs 626 and 627, and the second adder 629 is the A / D converters 624 and 62.
It is a circuit for adding the outputs of the five. The divider 630 is a circuit that divides the output of the first adder 628 by the output of the second adder 629.

Next, a method of calculating the display position of the test pattern of this embodiment will be described. First, the test pattern used in this embodiment will be described. As shown in FIG. 57 (a), the test pattern generating circuit 600 has a horizontal test pattern 6 at a predetermined position in the overscan area.
31 and a vertical test pattern 632 are generated respectively.

Each of the test patterns 631 and 632 is a linear pattern, and a test pattern having a peak in the luminance level in the width direction thereof, that is, in the horizontal scanning direction x and the vertical scanning direction y of the screen 7. To do. For example, it is assumed that the luminance level has a cos ² characteristic as shown in FIG. 57B, the Gaussian characteristic has a luminance level, or the luminance level has a linear mountain shape as shown in FIG. 57C. Cross hatch patterns having such luminance characteristics are sequentially generated in the width direction. The test pattern having the characteristic as shown in FIG. 57B can be easily obtained by passing a crosshatch pattern having a binary luminance value through an electrical and optical low-pass filter.

Next, the display position calculation processing will be described. Here, the barycentric position of the linear chevron test pattern shown in FIG. 57C is calculated as its display position. As shown in FIG. 57, the procedure for calculating the display position of the test pattern is the test pattern 63 in the horizontal scanning direction x and the vertical scanning direction y.
This is performed by sequentially projecting Nos. 1 and 632 on the display screen and selecting the outputs of the photodetectors 601 to 608 with the multiplexer 609 of FIG. Since all the detection units perform the same processing, only the calculation processing of the display position of the test pattern in the horizontal scanning direction in the light detection unit 601 will be described here.

First, as shown in FIG. 58, a photodetector 601.
For each of the photodetector elements 620 and 621 of
The coordinates are assigned, for example, X _n and X _{n + 1} , and the values are stored in the coefficient ROMs 626 and 627. Here, the peak-held and A / D-converted photodetection elements 620 and 62
If the outputs of 1 are Z _n and Z _{n + 1} respectively, the coefficient ROM 62
Reference numerals 6 and 627 respectively calculate and output the values of X _n .Z _n and X _{n + 1} .Z _{n + 1} . Further, these values are added to the first adder 62.
Input to 8 and add, and output (X _n · Z _n + X
_{n + 1} · Z _{n + 1} ).

On the other hand, the second adder 629 obtains the sum Z _n + Z _{n + 1} of the outputs of the photodetecting elements 620 and 621. These are input to the divider 630, and the output (X _n · Z _n + X _{n + 1} · Z _{n + 1} ) of the _first adder 628 is input to the second adder 62.
Divide by the output of 9 (Z _n + Z _{n + 1} ). In this way, the display position X of the test pattern is calculated. The calculation process of the display position is shown in the following equation (11).

(Equation 6) Equation (11) is the result when a linear chevron pattern is used, but even with a non-linear test pattern such as a cos ² or Gaussian distribution curve, the output X is expressed using that function to determine the position of the center of gravity. It can be calculated uniquely.

X _n · Z _n / (Z _n + Z _{n + 1} ) in the above equation and X
_{The n + 1} · Z _{n + 1} / (Z _n + Z _{n + 1} ) part is the photodetector element 62.
The output ratios from 0 and 621 are shown. The display position of the test pattern is calculated by weighting and adding this output ratio with the coordinates X _n , X _{n + 1} on the display screen assigned to the photodetectors 620, 621. As shown in FIG. 58, if the output ratio of the photodetecting elements 620 and 621 to the test pattern is 1: 1, the display position of the test pattern on the display screen is (X _n +
X _{n + 1} ) / 2 is obtained, and it can be seen that the test pattern is located at the midpoint between the photodetectors 620 and 621. The relationship between the test pattern width and the photodetector spacing is that the test pattern exists on at least two photodetectors.

Similarly, the display positions of the test patterns are calculated in the vertical direction, and the display positions of the test patterns in the horizontal direction and the vertical direction are calculated. Further, these processes are similarly performed for the light detection units 601 to 608 in the peripheral portion of the screen, and the display positions of the RGB test patterns corresponding to the adjustment points in the peripheral portion of the screen are calculated. By doing so, the error calculation unit 18 can detect an error in the display position of the test pattern due to geometric distortion or misconvergence. Then, the correction signal generation circuit 19 creates correction data from this error and corrects geometric distortion and misconvergence. Since the signal processing here is the same as that in the first embodiment,
The description of the operation is omitted. Further, by multiplexing the detection signals from the eight peripheral parts by time division processing in the vertical scanning cycle,
It is also possible to use one system of peak hold circuit or A / D converter.

As described above, in this embodiment, since the display position of the test pattern is calculated from the output ratio of the photodetector, it is less susceptible to the test pattern gain fluctuation and other fluctuation factors, and highly accurate. The display position of the test pattern can be calculated. Although the operation of calculating the display position of the test pattern has been described with the hardware configuration in the present embodiment, the same processing can be performed with software. As described above, according to the present embodiment, since the display position of the test pattern can be directly detected with high accuracy, highly accurate automatic adjustment can be performed in a short time.

A position detecting device according to an eleventh embodiment of the present invention will be described with reference to the drawings. FIG. 59 is a block diagram showing the overall structure of a projection type display including the position detecting device of the eleventh embodiment. In this figure, the same parts as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. Figure 5
9, the test pattern generation circuit 640 is a circuit that generates a test pattern for adjusting image distortion. The display position control unit 641 is a circuit that controls the display position of the test pattern, and the display position signal is the test pattern generation circuit 6.
Given to 40.

The photodetectors 642 to 649 are photoelectric conversion elements provided in the overscan area of the display screen. The light detecting elements 643, 645, 646, 648 are provided on the cross of the display screen, and the light detecting elements 642, 644, 64 are provided.
7, 649 are provided at the corners of the display screen. These photodetection elements are photoelectric elements that detect the brightness level of the test pattern that adjusts the geometric distortion and convergence of the image displayed on the screen 7, and a photodiode or the like is used.

The multiplexer 650 is the photodetector element 642.
It is a circuit that selects the output of ~ 649. The peak hold circuit 651 is a circuit that converts the output of the photodetection elements 642 to 649 selected by the multiplexer 650 into a DC signal. The A / D converter 652 is the peak hold circuit 6
This is a circuit for converting the output of 51 into digital data.
The CPU 653 is a signal processing unit that calculates the display position of the test pattern from the output of the A / D converter 652.

FIG. 60 shows a test pattern generation circuit 640.
3 is a block diagram showing a specific configuration example of a display position control unit 641. FIG. In this figure, a ROM 660 is a memory that stores test pattern data. D / A converter 6
Reference numeral 61 is a circuit for converting the data in the ROM 660 into an analog signal. The low pass filter (LPF) 662 is D /
It is a circuit that smoothes the output of the A converter 661. The address generator 663 constitutes the display position control unit 641, and is a circuit that generates a read address of the ROM 660 by using horizontal and vertical synchronization signals and a control signal from the CPU 653.

Next, the operation of calculating the display position of the test pattern of this embodiment will be described in detail. The test pattern used in this embodiment is the same as that in the tenth embodiment, and FIG. 57 is used for the description. First, a method of calculating the display position will be described. The procedure for calculating the actual display position of the test pattern is as follows. The test patterns in the horizontal scanning direction x and the vertical scanning direction y as shown in FIG. 57 are sequentially projected on the display screen, and the multiplexer 650 outputs the outputs of the photodetection elements 642 to 649. The selection and processing is the same as in the tenth embodiment.

FIG. 61 is an explanatory diagram of a method of calculating the display position of the horizontal scanning direction test pattern in the photodetector 642. First, the photodetector 642 detects the brightness level Z ₀ of the test pattern. Next, the display position control unit 641
Thus, the display position of the test pattern 631 is shifted by M at the coordinates on the display screen, and the brightness level Z ₁ at that time is detected. The display position of the test pattern is controlled by shifting the read address generated by the address generator 663. Here, if the coordinate X ₀ on the display screen is assigned to the photodetecting element 642, the display position X of the test pattern is calculated by the CPU 653 by the following equation (12).

(Equation 7)

Here, Z ₁ / (Z ₀ + in the equation (12) is used.
The portions Z ₁ ) and Z ₀ / (Z ₀ + Z ₁ ) show the output ratio of the brightness levels detected before and after shifting the display position of the test pattern. For example, if the ratio of the brightness levels before and after shifting the display position of the test pattern is 1: 1, the display position X of the test pattern is X ₀ + M /
It is 2 and it can be seen that M / 2 is at the right position with respect to the photodetector 642.

The display position of the test pattern can be calculated by weighting and adding the output ratio of the brightness level before and after the test pattern is shifted as in the equation (12) with the shift amount of the test pattern. Although the process of calculating the display position by software has been described here, this process can also be realized by a configuration of only hardware. Further, in the present embodiment, the test pattern generation circuit 640
Although the display position is controlled by controlling the above, the same processing can be realized by controlling the deflecting unit and the auxiliary deflecting unit. It can be said that such a correction method is the most suitable control method for a multi-scan type magnifying projection apparatus that supports various scanning frequencies.

In this way, the display position of the test pattern can be directly detected by calculating the output ratio of the brightness level when the display position of the test pattern is shifted. Therefore, the displacement of the test pattern due to geometric distortion or misconvergence can be detected from the display position of the test pattern.

Since the display position of the test pattern is calculated from the output ratio of the photodetector in this embodiment, the display position of the test pattern is calculated with high accuracy without being affected by the gain variation of the test pattern and other fluctuation factors. can do. Further, from the display position of the detected RGB test pattern, geometric distortion and misconvergence are detected and corrected by the same processing as in the first embodiment. As described above, according to the present embodiment, the display position of the test pattern can be directly detected with high accuracy, so that high-precision automatic adjustment can be performed in a short time.

A position detecting apparatus according to the twelfth embodiment of the present invention will be described with reference to the drawings. FIG. 62 is a block diagram showing the overall structure of a projection type display including the position detecting device of the twelfth embodiment. In this figure, the same parts as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. Figure 6
2, the test pattern generation circuit 670 is a circuit that generates a test pattern for adjusting image distortion. The photo detectors 671 to 678 are a group of photo detectors provided in the overscan area of the display screen. The light detection unit 672,
674, 675, and 677 are arranged on the cross of the screen 7, and the photodetectors 671, 673, 676, and 678 are arranged at the corners of the screen 7.

The multiplexer 679 includes the photodetection units 671 to 671.
This is a circuit for selecting the output of 678. Unnecessary light removing unit 68
Reference numeral 0 is a circuit that removes unnecessary light such as reflected light inside the projection device set and external light from the output of the photodetector selected by the multiplexer 679 by signal processing. The position calculation unit 681 is a circuit that calculates the display position of the test pattern from the output of the light detection unit from which the unnecessary light component is removed by the unnecessary light removal unit 680.

FIG. 63 is a block diagram of the photodetectors 671-678. Here, the photodetectors 671 to 678 shown in FIG. 62 have the same configuration, and each photodetector has photodetector elements 690, 691, and 692 as shown in FIG. The light detection elements 690, 691, 692 are made of photoelectric conversion elements such as photodiodes and phototransistors, and are arranged obliquely with respect to the horizontal scanning direction x and the vertical scanning direction y of the screen 7. In this embodiment, three photodetecting elements are used for simplification of description, and the test pattern is received by the two photodetecting elements and the unnecessary light is received by the remaining one photodetecting element. It is effective that the number of the photodetecting elements is three or more, and the width of the test pattern is adjusted so that the photodetecting elements are formed into a predetermined plurality of photodetecting elements.

FIG. 64 is a block diagram showing a specific structural example of the unnecessary light removing section 680. In the figure, peak hold circuits 693, 694, and 695 are circuits that convert the outputs of the three photodetection elements into DC signals, respectively. The A / D converters 696, 697 and 698 are peak hold circuits 69.
This is a circuit for converting the outputs of 3, 694 and 695 into digital data. The minimum value calculation circuit 699 is the A / D converter 6
This is a circuit for calculating the minimum value of the outputs of 96, 697, and 698. The difference units 700, 701, and 702 are A / D converters 6
Minimum value calculation circuit 699 from the outputs of 96, 697, 698
Is a circuit that subtracts the output of each.

FIG. 65 is a block diagram showing the structure of the minimum value calculating circuit 699 provided in the unnecessary light removing section 680.
In this figure, the first comparator 703 compares the outputs (Z ₀ , Z ₁ ) of the A / D converters 696, 697 of FIG. 64, and compares the results (for example, 0, Z ₀ when Z ₀ ≧ Z ₁ ). This circuit outputs 1) in the case of <Z ₁ . The first selector 704 is A
The outputs of the D / D converters 696 and 697 are supplied to the first comparator 70.
It is a circuit that selects based on the output of 3. For example, when the output of the first comparator 703 is 0, Z ₁ is selected, and when it is ₁ , Z ₁ is selected.
Select ₀ . The second comparator 705 is the first selector 7
04 output (Z ₃ ) and the output of the A / D converter 698 (Z ₂ ) are compared, and the comparison result (for example, when Z ₃ ≧ Z ₂ , 0, Z ₃ <
This is a circuit that outputs 1) in the case of Z ₂ . The second selector 706 outputs the output of the first selector 704 and the A / D converter 6
This circuit selects the output of 98 based on the output of the second comparator 705. For example, when the output of the second comparator 705 is 1, Z ₃ is selected, and when it is 0, Z ₂ is selected.

Next, the method of calculating the display position of the test pattern of this embodiment will be described. The shape of the test pattern used in this embodiment is the same as that of the eleventh embodiment, and FIG. 57 is used for the description. The test pattern of this embodiment is
The width thereof is narrower than the detection area of the photodetectors 671 to 678.

First, the operation of removing unnecessary light in this embodiment will be described. In the projection type display, unnecessary light other than the test pattern may be incident on the light detection unit due to reflected light inside the projection device set or external light. This adversely affects the adjustment of the geometrical distortion and the convergence distortion, so that it is necessary to remove this unnecessary light in order to perform the highly accurate adjustment. As shown in FIG. 66A, since the test pattern of this embodiment has an irradiation area narrower than the detection range of the photodetector 671, there is a photodetection element 690 not irradiated with the test pattern. The output of the photodetector 690 on which only unnecessary light is incident is smaller than the output of the photodetector 691, 692 in the irradiated portion. As a result, the minimum value detection circuit 699 is used and each photodetection element 6 is
When the minimum value of 90, 691, 692 is obtained, the unnecessary light component is detected.

Further, the differencers 700, 701, 702 are used to remove unnecessary light components from the photodetectors 690, 691, 69.
The unnecessary light component is removed by subtracting from the output of 2. Further, as another method for reducing unnecessary light received by the photodetector, there is also a method in which, for example, a cylindrical light shield 693 is provided around the photodetector as shown in FIG. 66 (b). . Further, as shown in FIG. 66 (c), by using a photodetector element having a narrow directional characteristic, unnecessary light components can be further removed.

The process of calculating the display position of the test pattern from the output of each photodetector from which unnecessary light has been removed is similar to that of the tenth embodiment, and therefore its explanation is omitted. The processing method of performing geometric distortion and convergence correction from the calculated display position of the test pattern is the same as that in the first embodiment, and therefore its description is omitted. As described above, according to the twelfth embodiment, it is possible to perform highly accurate adjustment by removing unnecessary light such as reflected light and external light inside the projection device set.

An image correcting apparatus according to the thirteenth embodiment of the present invention will be described with reference to the drawings. FIG. 67 is a block diagram showing the overall construction of a projection type display including the image correction device of the thirteenth embodiment. In this figure, the same parts as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. Figure 6
In FIG. 7, a low pass filter (LPF) 710 is a circuit that generates an image signal having an average luminance of one field / frame period of a video signal. The test pattern generation circuit 711 is a circuit for generating a test pattern for geometric distortion and convergence adjustment. First switching circuit 712
Is a circuit for switching the output of the low pass filter 710 and the output of the test pattern generation circuit 711. The second switching circuit 713 is a circuit for switching between the output of the first switching circuit 712 and a normal video signal. The timing generator 714 includes a first switching circuit 712 and a second switching circuit 713.
2 is a circuit for generating a switching timing signal. Second
The output of the switching circuit 713 is given to the video circuit 3.

The light detectors 715 to 722 are screens 7.
Is an aggregate of photodetection elements provided in the overscan region of. The photodetectors 716, 718, 719, 721 are arranged on the cross of the screen 7, that is, in the upper, lower, left and right central portions, respectively, and the photodetectors 715, 717, 720, 722 are arranged at the peripheral corners of the screen 7. There is. These photodetectors detect the brightness level of the test pattern displayed on the screen 7. The multiplexer 723 is a circuit that selects the output of each photodetector 715 to 722. The position calculation unit 724 is a circuit that calculates the display position of the test pattern from the output of the light detection unit selected by the multiplexer 723. The configuration of the light detection units 715 to 722 is the tenth.
This is similar to FIG. 55 of the embodiment.

Next, a correction method of the image correction apparatus of this embodiment will be described. In a multi-scan projection display that displays video signals of various specifications, in order to adjust geometric distortion and convergence while displaying video, superimpose an adjustment test pattern on the video signal and perform this test. The pattern needs to be detected by the photodetector. If the screen size of the video signal is small as shown by video V1 in FIG. 68 (a), the test pattern may not be emitted to the photodetection unit.

Therefore, as shown in the image V2 of FIG. 68 (b), it is necessary to enlarge and adjust the screen size so that the test pattern can be detected. In this case, if the test pattern is superimposed on the video signal as it is, FIG.
The image is enlarged at the time of correction as shown by the circular pattern in the center of the screen 7. In this case, the correction operation becomes very noticeable, so when displaying the video signal during correction,
The average value of the luminance signal is taken and the value (DC potential) is displayed on the screen 7 as a video signal within one frame. In this way, the continuity of the brightness before and after the correction is maintained, and the correction operation can be made inconspicuous. Then, geometric distortion and convergence are corrected while displaying a flat image having uniform luminance and hue on the screen.

Next, the correction operation of this embodiment will be described. The shape of the test pattern used in this embodiment is the eleventh.
This is the same as the embodiment, and FIG. 57 is used for the description. First, the LPF 710 of FIG. 67 calculates the average value of one field / frame of the video signal. The average value of the video signal is LPF
It can be obtained by appropriately selecting the cutoff frequency of 710. Then, in order to superimpose the test pattern on the video signal, in the timing generation unit 714, the average value of the video signal and the test pattern switching timing signal are set to the first and the second from the information of the screen size of the video signal and the screen size of the test pattern. 2 switching circuits 712, 71
It should output to 3.

Information on the screen size including the aspect ratio and the length in the main scanning direction and the length in the sub scanning direction is obtained by the deflection circuit 21.
Is obtained from the amplitude of the deflection current. As shown in the left side of FIG. 69, for example, when the screen size (length in the scanning direction) of the video signal is Ws and the screen size of the test pattern is Wt, the timing signal is Ws / Wt times the horizontal and vertical periods, respectively. Only the average value of the video signal is selected, and the other values are control signals for selecting the test pattern. The video signal thus obtained is (Ws / Wt) times the screen size of the test pattern, as shown in FIG. 69, and is a window pattern superimposed such that its luminance level becomes the average value of the video signal. .

As shown in FIG. 70, when the image is corrected, the test pattern is set in each of the photodetectors 715 to 722 in the peripheral portion of the screen.
The screen size is controlled so that the area is illuminated. With such a pattern, even when the test pattern is displayed during correction, the change in the brightness level of the entire screen of the video signal is reduced, and the effect of making the insertion of the test pattern inconspicuous is produced.

Next, the photodetector 71 arranged in the peripheral portion of the screen
5 to 722, the display position of the RGB test pattern is calculated, but since this processing is the same as in the tenth embodiment, description thereof is omitted. Further, the processing method for correcting the geometrical distortion and the convergence from the calculated display position of the test pattern is the same as that of the first embodiment, and therefore its explanation is omitted. As described above, according to the present embodiment, a test pattern for adjustment is inserted into a multi-scan or multi-aspect video signal, and the change in the brightness level of the entire screen is small,
It is possible to realize an image correction device having a function in which the test pattern insertion operation is inconspicuous.

An image correction apparatus according to the 14th embodiment of the present invention will be described with reference to the drawings. FIG. 71 is a block diagram showing the overall construction of a projection type display including the image correction device of the fourteenth embodiment. In this figure, the same parts as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. Figure 7
1, the test pattern generation circuit 730 is a circuit that generates a test pattern for image distortion adjustment. The display position control unit 731 is a circuit that controls the display position of the test pattern.

The photo detectors 732 to 739 are a group of photo detectors provided in the overscan area of the screen 7. The photodetectors 733, 735, 736, 738 are arranged on the cross of the screen 7, and the photodetectors 732, 73
4, 737 and 739 are arranged at the corners of the screen 7. These photo-detecting units are composed of a plurality of photoelectric conversion elements such as photodiodes, and detect the geometric distortion displayed on the screen 7 and the brightness level of the test pattern for convergence adjustment. The multiplexer 740 is a circuit that selects the output of each photodetector 732 to 739. The position calculation unit 741 is a circuit that calculates the display position of the test pattern from the output of the light detection unit selected by the multiplexer 740. The configuration of the photodetectors 732 to 739 is the tenth.
It is similar to FIG. 54 of the embodiment.

The operation of the position detecting device 26 will be described with reference to FIG.
To use. Further, the configurations of the test pattern generation circuit 730 and the display position control unit 731 are the same as those in the eleventh embodiment, and therefore detailed description thereof will be omitted. First, a method of calculating the display position of the test pattern according to this embodiment will be described. The test pattern used in this embodiment is the same as in the tenth embodiment.

First, a method of calculating the display position will be described. For example, as shown in FIG. 72, when the horizontal test pattern 631 and the vertical test pattern 632 do not exist in the photodetection units 732 to 739 provided in the peripheral portion of the screen, these test patterns 631 and 632 are detected by light. It is necessary to move to a position where the parts 732 to 739 can be irradiated. Hereinafter, the operation of moving such a test pattern to a position where it can be detected by the photodetector will be referred to as a test pattern search.

The display position of the test pattern can be obtained from the moving amount of the test pattern by the search. Here, a test pattern search method for moving the test pattern to a position where it can be detected by the photodetectors 732 to 739 will be described. Since the operation of the test pattern search is the same for each of the photodetection units 732 to 739, here, the photodetection unit 7 is used.
Only 32 will be described.

As shown in FIG. 73, the search for the test pattern is performed by the photodetector 732 in the horizontal test pattern 63.
When 1 is not radiated, the display position control unit 731 moves the test pattern 631 at a movement interval slightly smaller than the detection area of the light detection unit 732.
For example, the test pattern is moved by sequentially increasing the left and right movement intervals in the order of the numbers shown in FIG.
Repeatedly move to a position that can be detected with. Then, the number of times of movement of the test pattern until the test pattern can be detected is N (N = 3 in FIG. 73), the movement interval of the test pattern is M, and the light detection of the test pattern at the time when the test pattern can be detected. Assuming that the detection position in the part is X ₀ , the display position X of the test pattern can be calculated by the following equation (13).

(Equation 8)

Here, the position calculation processing of the test pattern in the photodetection section is the same as that of the tenth embodiment, and therefore its explanation is omitted. Further, although the search of the test pattern 631 in the horizontal direction has been described here as shown in FIG. 73, the same processing is performed in the vertical direction.

Next, the test pattern search procedure for the photodetection sections 733, 735, 736, 738 arranged on the cross of the display screen and the photodetection sections 732, 734, 737, 739 arranged in the peripheral section. 74 to 7
This will be described using 6. The test pattern search procedure is
Basically, the corner of the screen is searched after the search on the cross of the display screen. 77 and 78 are flowcharts showing the search procedure of the test pattern.

First, as shown in the processing from step S0 in FIG. 77, the search on the screen cross is performed as shown in FIGS.
Will be explained. When the start of the search on the screen cross is instructed in step S0 of FIG. 77, the process proceeds to step S1.
A V-direction pattern search is performed on the upper and lower parts of the screen cross. Therefore, in step S2, the V-direction pattern is moved upward by Y ₁ as shown in FIG. Then, in step S3, as shown in FIG. 74 (b), the pattern is moved to the right by X _{1 with} respect to the upper portion on the screen cross, and the pattern search in the H direction is performed.

Next, in step S4, the V direction pattern is moved downward by Y ₂ from the initial position as shown in FIG. 74 (a). In the next step S5, a pattern search in the H direction is performed on the lower portion on the cross of the screen to obtain the movement amount X ₂ . In this way, the pattern movement amounts Y ₁ and Y ₂ are calculated in step S6, and the search for the vertical test pattern 632 in the central portion of the screen is completed with respect to the upper and lower photodetection portions 733 and 738 on the screen cross. Thus, the amount of movement of the test pattern with respect to the photodetector (X ₁ ,
Y ₁ ) and (X ₂ , Y ₂ ) are calculated.

Next, in step S7, an H-direction pattern search is performed on the left and right portions on the screen cross as shown in FIG. 75 (c). For this purpose, the process proceeds to step S8, and the left horizontal test pattern 631 is moved by the movement amount X ₃ to perform the search. Next, proceeding to step S9, FIG.
As shown in (d), the pattern is moved upward by Y _{3 with} respect to the left portion on the screen cross, and the pattern search in the V direction is performed. Then, in the next step S10, the search is performed by moving the right side horizontal test pattern 631 by the movement amount X ₄ . When the process proceeds to step S11, the pattern is moved upward by Y _{4 with} respect to the right portion on the screen cross, and the pattern search in the V direction is performed. In this way step S12
Then, the pattern movement amounts X ₃ and X ₄ are calculated, and the search for the horizontal test patterns 631 on the left and right sides of the screen is completed with respect to the upper and lower photodetection sections 733 and 738 on the screen cross.

By the above processing, the display positions of the test patterns corresponding to the left and right photodetection portions 735 on the cross of the screen are obtained as (X ₃ , Y ₃ ), and the photodetection portion 736 also has (X ₄ , Y ₄ ). The above process completes the search on the screen cross.

Next, with reference to the search for the peripheral portion of the screen, see FIG.
And the flowchart of FIG. 78. When the search of the peripheral portion of the screen is instructed, the process proceeds to step S13, and the process of moving the H direction pattern in the X direction and the V direction pattern in the Y direction is performed as shown in FIG.
That is, the process proceeds to step S14, and the pattern search in the H and V directions is performed on the photodetector 732 in the upper left portion on the screen cross. To do this, proceed to step S15, move the H-direction pattern to the left by X ₃ , and further move the V-direction pattern to Y.
Move ₁ upwards. After that, horizontal and vertical searches are performed by finely moving the test pattern by Y ₅ , and the display position of the test pattern corresponding to the photodetector 732 is detected.

In the same manner, the process proceeds to step S16, and pattern search in the H and V directions is performed on the photodetection section 731 in the lower left portion of the screen cross. For this, step S1
In step 7, the H-direction pattern is moved in the X direction and the V-direction pattern is moved in the Y direction in the same manner as the processing in step S13. In this way, the H-direction pattern is moved to the left by a predetermined amount, and further the V-direction pattern is moved downward by a predetermined amount.

Thereafter, the process proceeds to step S18, and pattern search in the H and V directions is performed for the photodetector 734 in the upper right portion on the screen cross. To this end, the process proceeds to step S19, where the H-direction pattern is moved in the X direction and the V-direction pattern is moved in the Y direction. Further, go to step S20,
H, V for the light detection unit 739 in the lower right part of the screen cross
Directional pattern searches are performed respectively. When the search of the peripheral portion of the screen is finished in this way, all the searches are completed.

In this way, first, the cross on the screen is searched,
By using the movement amount of the test pattern at that time,
The test pattern can be searched a smaller number of times than the search from the position of the test pattern in the initial state shown in FIG. Therefore, the efficiency of the search and the adjustment time can be shortened.

With the above-described processing, the attention points of the RGB test patterns corresponding to the photodetectors 732 to 739 on the screen cross and the corners of the screen are searched, and their display positions are calculated. This makes it possible to easily detect geometric distortion and misconvergence. The method for creating the correction data for the detected geometric distortion and misconvergence is the same as that in the first embodiment, and therefore its description is omitted. Thus, according to this embodiment,
First, by searching the cross on the screen and using the movement amount of the test pattern at that time, the efficiency of the search can be improved.

An image correction apparatus according to the fifteenth embodiment of the present invention will be described with reference to the drawings. FIG. 79 is a block diagram showing the overall construction of a projection type display including the image correction device of the fifteenth embodiment. In this figure, the same parts as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. Figure 7
9, the test pattern generation circuit 770 generates a test pattern for measuring the projection distance to the photodetector as the first test pattern, and a test pattern for image distortion and convergence adjustment as the second test pattern. Is a circuit for generating.

Unlike the previous embodiments, the photodetectors 771 to 778 are CRTs which are magnifying projection tubes when viewed from the display screen.
It is an assembly of photodetection elements that are present on the fourth side and are located on the outer peripheral portion of the pyramidal projection beam. Light detector 7
72, 774, 775, and 777 are arranged in a cross shape when viewed from one screen 7, and light detection units 771, 773, and 7 are provided.
76 and 778 are arranged at the corners of the screen 7.
These photodetection units are composed of a plurality of photoelectric conversion elements such as photodiodes, and detect the brightness level of the test pattern. The multiplexer 779 is the light detection units 771 to 778.
It is a circuit that selects the output of.

The projection distance calculation unit 780 is the multiplexer 7
It is a circuit that calculates the projection distance to the light detection unit from the brightness level of the test pattern for measuring the projection distance, using the outputs of the light detection units 771 to 778 selected by 79. The position calculation unit 781 inputs the geometric distortion of the image and the brightness level of the test pattern for convergence adjustment, and calculates the display position of the test pattern from the projection distance to the light detection unit calculated by the projection distance calculation unit 780. Circuit.

A method of adjusting geometrical distortion and convergence in this embodiment will be described. First, the necessity of measuring the projection distance to the light detecting element will be described. For example, consider a projection display 782 having a multi-display screen as shown in FIG. This projection display 782
Shows a plurality of display screens arranged in a matrix like the units # 1 to # 4. In such a projection type display 782, in order to improve the image quality of the entire screen, the joint 783 of the display set is extremely narrow and has a structure that is as inconspicuous as possible.

In such a case, the photodetector is connected to the screen 7
It is difficult to dispose on the periphery of the display screen. For example, as shown in the lower part of FIG. 80, it is necessary to arrange the photodetection units 771 to 778 at positions away from the display screen 784 so as not to block the projection beam of the effective screen. In such a case, due to the structure of the projection display 782, a plurality of light shielding parts 790 as shown by the diagonal lines are provided on the non-imaging surface at a position distant from the display screen 784. The light shield 790 is for preventing image projection light other than the effective display area from entering the adjacent unit. A substrate is attached to the side of the light shield 790 facing the CRT 4, and the photodetectors 771 to 778 are fixed on the substrate.

If RGB convergence correction is performed in such an arrangement, as shown in FIG. 81, even if the RGB test patterns match on the photodetector, they may shift on the display screen 784. There is. In such a case, the projection tubes 785, 78 are required to perform accurate correction.
It is necessary to detect the projection distance from 6,787 to the light detection unit. When the photodetector as described above is present on the non-imaging surface indicated by the broken line P1, it is necessary to calculate the shift amount Y ₀ of the display screen indicated by the solid line P2 and then correct the image.

Next, a method of calculating the projection distance to the light detection units 771 to 778 will be described. In this processing, the test pattern generation circuit 770 generates window patterns 788 to 795 corresponding to the respective photodetection units 771 to 778 as shown in FIG. Then, the light detection units 771 to 778 detect the brightness levels of these window turns, respectively. Here, the photodetectors 771 to 778
FIG. 82B shows the characteristics of the brightness level of the test pattern with respect to the projection distance to.

As shown in FIG. 82 (b), the screen brightness is inversely proportional to the projection area, and the projection distance is inversely proportional to its squared value. In this way, the photodetectors 771-7
The projection distance to 78 and the brightness level of the test pattern detected at that time have a one-to-one relationship. The relationship is uniquely determined by the structural parameters of the projection optical system of the display such as the image enlargement ratio and the projection angle. Therefore, if the brightness level is detected, the projection distance to the light detection units 771 to 778 can be calculated. The projection distance calculation unit 780 in FIG. 79 calculates the projection distance to the light detection unit using the detected brightness level based on the structural parameter of the projection optical system of the display.

Next, the position calculation unit 781 calculates the display position of the geometric distortion and the test pattern for convergence adjustment. Since this test pattern is the same as that of the first embodiment, FIG. 57 is used for the description. For this, the test pattern is detected by the light detection units 771 to 778 and the display position of the test pattern is calculated. However, since this processing is the same as that of the tenth embodiment, the description thereof is omitted.

Next, the display position of the test pattern calculated by the position calculation unit 781 is corrected by the projection distance to the light detection units 771 to 778 calculated by the projection distance calculation unit 780, and the actual display screen is displayed. A method of obtaining the display position of the test pattern will be described. FIG. 83 is a diagram showing the positional relationship of the light detection units 771, 772, and 773 with respect to the projection tube and the display screen of the display device as seen from above the magnifying projection device 24. Although only three light detection units are shown in this figure for simplification of description, it is assumed that the same processing is performed for other light detection units in the projection display 782. Further, although the present drawing describes the horizontal test pattern 631 shown in FIG. 57, the same applies to the vertical test pattern.

As shown in FIG. 81, each RGB projection tube 78
The angle of concentration of 5, 786 and 787 is φ. As shown in the drawing, assuming that the concentration angle of the G projection tube 786 is 0, the R projection tube 7
The concentration angle of 85 is φ, and the concentration angle of the B projection tube 787 is −φ. In addition, the angle of magnified projection with respect to the central axis of each projection tube
The distance between the display screen and the photodetector obtained by the above-mentioned projection distance calculation process is Y ₀ , and the position of the photodetector seen from the projection tube is θ (however, the photodetection is performed in the direction perpendicular to the projection tube. If θ = 0) when there is a copy, the correction amount X is calculated by the following equation (14). X = Y ₀ tan (φ−θ) (14)

From the equation (11), for example, the correction amount of the R test pattern is Y ₀ ta in the photodetector 771.
n (φ−ω), Y ₀ tanφ in the photodetector 772, and Y ₀ tan (φ + ω) in the photodetector 773. At the display position of the test pattern calculated by the photodetector ((1
By adding the correction amount by the equation 4), the display screen 78
It is possible to obtain the display position of the test pattern on the display 4. Further, geometric distortion and misconvergence are detected and corrected from the detected display positions of the respective test patterns of RGB, which is the same processing as in the first embodiment.
Descriptions thereof are omitted.

In the present embodiment, the position calculation unit 781 corrects the error between the detected position of the test pattern and the actual display position on the display screen. The correction signal generation circuit 19 corrects the error data corresponding to the error. The correction data may be created in consideration. In addition, in the present embodiment, in the projection display 782 having a multi-display screen, the light detection unit 7
Although 71 to 778 are provided in each unit, as shown in FIG. 83, the photodetector is shared by each unit and installed on the light shield 790, and geometric distortion and convergence are sequentially corrected for each unit. You may go.

As described above, according to the present embodiment, even when it is necessary to dispose the photodetection section on the non-imaging plane as in the case of a display of a multi-display screen, the test can be performed from the brightness level of the test pattern. By calculating the error between the detection position of the pattern and the actual display position on the display screen, it is possible to accurately adjust the geometric distortion and the convergence.

An image correction apparatus according to the 16th embodiment of the present invention will be described with reference to the drawings. FIG. 84 is a block diagram showing the overall construction of a projection type display including the image correction apparatus of the 16th embodiment. In this figure, the same parts as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. FIG.
4, the test pattern generation circuit 800 generates a test pattern for measuring the projection distance to the photodetection unit as a first test pattern, and a test pattern for image distortion and convergence adjustment as a second test pattern. Circuit. The display position control unit 801 is a circuit that controls the display position of the test pattern.

Like the fifteenth embodiment, the photodetectors 800 to 809 are present on the CRT4 side when viewed from the multi-display screen,
It is an assembly of photodetection elements provided on the outer periphery of a pyramidal projection beam. Light detectors 803, 805, 806, 80
8 is arranged on the cross as seen from one screen 7,
The photodetectors 802, 804, 807, 809 are arranged at the corners of the screen 7. These photodetection units are composed of a plurality of photoelectric conversion elements such as photodiodes, and detect the brightness level of the test pattern. Multiplexer 81
Reference numeral 0 is a circuit that selects the output of each of the light detection units 802 to 809.

The projection distance calculation unit 811 is the multiplexer 8
10 is a circuit for calculating the projection distance to the light detection unit from the brightness level of the test pattern for measuring the projection distance, which is selected by 10 and output from the light detection units 802 to 709. The position calculation unit 812 outputs the output of the light detection units 802 to 809 selected by the multiplexer 810 to the brightness level of the test pattern for geometrical distortion and convergence adjustment and the light detection unit calculated by the projection distance calculation unit 811. It is a circuit that calculates the display position of the test pattern from the projection distance.

Next, a method of correcting geometric distortion and convergence according to this embodiment will be described. Similar to the fifteenth embodiment, this embodiment is directed to a case where it is difficult to dispose the photodetection unit in the peripheral portion of the display screen, such as a projection display having a multi-display screen. Here, as in the fifteenth embodiment, a window pattern as shown in FIG. 82 is displayed,
The projection distance to the light detection unit is calculated from the brightness. Since the method of calculating the projection distance is the same as that of the fifteenth embodiment, the description thereof will be omitted.

Next, the test pattern generating circuit 800 creates a test pattern for geometric distortion and convergence adjustment, and the enlarged projection device 24 displays the test pattern. Then, the position calculation unit 812 calculates the display position of the test pattern. Here, the display position control unit 801 displays the test pattern so as to correct the difference between the position of the test pattern on the light detection unit and the position on the actual display screen from the calculated projection distance to the light detection unit. Control the position. As a result, it is possible to correct the error between the detection position of the test pattern by arranging the photodetector on the non-imaging surface and the display position on the actual display screen, and perform accurate geometric distortion and convergence adjustment. be able to.

The structure of the test pattern display position controller 801 is the same as that of the eleventh embodiment, and therefore its explanation is omitted. Figure 85
FIG. 6 is a diagram of the photodetectors 802, 803, and 804 as viewed from above the projection display of the positional relationship of the display device with respect to the projection tube and the display screen. In this figure, only three photodetection units are shown for the sake of simplicity, but it is assumed that similar processes are performed for the other photodetection units.

Each RG of the display as shown in FIG.
The angle of concentration of the B projection tubes 785, 786, and 787 is φ (the angle of concentration of R is φ, the angle of concentration of G is 0, and the angle of concentration of B is −φ). Also, the angle of the magnified projection is ω, the distance between the display screen and the photodetector is Y ₀ , and the position of the photodetector seen from the projection tube is θ.
(However, when the photodetector is present in the direction perpendicular to the projection tube, θ = 0), the enlargement ratio in enlarged projection is N. Then, the correction amount of the test pattern due to the difference between the position of the test pattern on the photodetector and the actual display position on the display screen is calculated by the following equation (15). X = Y ₀ tan (φ−θ) / N ... (15)

From the equation (15), for example, the correction amount of the display position of the R test pattern is Y ₀ tan (φ−ω) / N in the portion corresponding to the photodetector 802 and in the portion corresponding to the photodetector 803. Y ₀ tan φ / N, and Y ₀ tan (φ + ω) / N at the portion corresponding to the photodetector 804.

For example, as shown in FIG. 86, the display position controller 801 displays on the display screen 784 a test pattern in which the difference between the position of the test pattern in the photodetector and the actual display position on the display screen is corrected. To do. Fig. 86
(A) is the original position of the test pattern for each color when the projection optical system is not present. Next, FIG. 86 (b)-
As shown in (d), the RGB test pattern is detected by the light detection unit, and the display position of the test pattern is calculated.
In this way, geometric distortion and convergence are corrected,
Since this processing is similar to that of the tenth embodiment, the description thereof will be omitted.

As described above, according to the present embodiment, even when it is necessary to dispose the photodetection section on the non-imaging plane as in the case of a multi-display screen display, the brightness level of the test pattern The projection distance is calculated automatically,
By controlling the position of the test pattern and calculating the display position, it is possible to more accurately adjust the geometric distortion and the convergence.

In each of the embodiments, an image display device using a CRT as a magnifying projection tube has been described for easy understanding, but it goes without saying that other display devices are also effective. Also, in each example,
Although the integrated video projector has been described as the magnifying projection device, the same applies to a magnifying projection device having a separate structure and a direct-view tube type display device.

Further, in each of the embodiments, the case where the photodetector is installed near the image forming surface outside the effective screen of the screen has been described, but it may be installed inside the effective screen or on the non-image forming surface for detection. . Further, in each of the embodiments, the case where the photodetecting elements are installed on the screen cross outside the effective screen of the screen at eight locations around the four corners has been described, but it may be detected at other locations or numbers. Further, in each of the embodiments, the case where the image distortion such as the geometric distortion and the convergence is corrected is described, but the brightness correction other than the above may be performed. Further, in each embodiment, the case where the number of the photodetecting elements in each detection region is set to 2 to 3 has been described, but the number may be other than that.

In each of the embodiments, the case where the test patterns for detecting each color are sequentially projected to detect the position has been described. However, a color filter may be provided on the photodetector to detect each color at the same time. Further, in each of the examples, the case where a test signal having a linear mountain shape symmetrical with respect to the apex of the test pattern, a cos ² characteristic, or a Gaussian characteristic is used is described.
Any signal may be used as long as it is a test signal whose brightness level changes.

In the third embodiment, the case where the photodetecting elements are arranged on the grid with respect to the horizontal and vertical directions to detect the position coordinates has been described. May be.

In the fourth embodiment, the case where a linear chevron-shaped test signal is used for position detection (signal search) and a crosshatch-shaped test signal is used for error detection has been described. It may be a signal whose signal level changes or a high frequency signal.

In the fifth embodiment, the description has been given of the case where the photodetecting elements are installed in the four corner peripheral portions in the direction of 45 degrees oblique to each scanning direction. However, the inclination angles are changed according to the aspect and the correction amount. Good.

In the sixth embodiment, the case where a plurality of photodetector elements are installed on the screen cross at right angles to the scanning directions and at the four corners obliquely to the scanning directions has been described. You may add and detect the photodetection element for position detection in the peripheral part of four corners.

Further, in the seventh embodiment, the case where the position and error are detected by controlling the correction signal has been described, but the display position of the test signal may be controlled.

In the eighth embodiment, the error detection is described based on the position detection signal from the test pattern, the elapsed time after the power is turned on, and the temperature inside the set. However, other combinations may be used.

Further, in the ninth embodiment, the case where the crosshatch signal is used as the test pattern for the position detection and the error detection is described, but other signals may be used.

Further, in the tenth to sixteenth embodiments, the case where the photo-detecting elements are arranged obliquely with respect to the respective scanning directions has been described. However, as in the sixth embodiment, the cross on the screen crosses in the respective scanning directions. It may be installed at a right angle to.

Further, in the tenth embodiment, the case where the position of the test pattern is calculated using a signal whose luminance level changes in the line width direction with a cos ² characteristic, a Gaussian characteristic, or a linear mountain shape has been described. Other signals other than the Yamagata symmetry may be used.

Also, in the eleventh embodiment, the case where the display position of the test pattern is shifted by controlling the signal system and the deflection system has been described, but it may be performed by other means.

In the twelfth embodiment, the case has been described in which the photodetection elements for detecting the position and the unnecessary light are provided in the same region for detection, but the photodetection element for detecting the unnecessary light is separately provided. May be.

In the thirteenth embodiment, the DC signal is used as the average value of the video signal.
If necessary, other average value signals may be used.

Further, in the fourteenth embodiment, the case where the display position of the signal itself of the test pattern is controlled has been described. However, the signal search and the detection of the correction sensitivity are used in combination by controlling the auxiliary deflection means such as convergence. You may go.

Further, in the fifteenth to sixteenth embodiments, the case where the projection distance is calculated from the brightness level of the window pattern has been described, but other widths such as a crosshatch signal may be used.

[0253]

As described above, according to the inventions of claims 1 to 4 of the present application, a test pattern in which the luminance level is linear with respect to at least one of the orthogonal coordinate directions on the image display device is provided. Project. Then, the brightness level of the test pattern and its inclination value are detected by the outputs of the plurality of photodetection elements arranged on the outer periphery of the display screen. This makes it possible to detect the display position of the test pattern in a short time and with high accuracy.

Further, according to the inventions of claims 5 to 7 of the present application,
A test pattern having a linear brightness level is moved by a minute distance in at least one of the orthogonal coordinate directions on the display screen of the image display device. Then, the display position of the test pattern is calculated from the change in the brightness level of the test pattern detected by the photodetector. This can reduce the number of photodetectors provided on the outer periphery of the display screen. Further, the value of image distortion can be detected with high accuracy in a short time.

Further, according to the inventions of claims 8 and 9 of the present application,
On the display screen of the image display device, two-dimensional plane coordinates on the display screen are assigned to the respective photodetecting elements arranged in a matrix. Next, the display position of the test pattern can be directly calculated by weighting and adding the coordinates assigned by the output of each photodetecting element.

According to the tenth and eleventh aspects of the present invention, two types of test patterns for position detection (for signal search) and error detection are generated. Then, using these test patterns, the direction and error of the test pattern are calculated. By doing so, the value of image distortion can be detected with high accuracy. Further, the geometric distortion and the convergence distortion can be corrected with a simple structure in a short time and with high accuracy.

According to the twelfth and thirteenth aspects of the present invention, a plurality of photo-detecting elements are installed on the screen cross at right angles to the scanning directions and at the four corners obliquely to the scanning directions. By doing so, the display position of the test pattern can be detected with high accuracy at all positions on the screen. By using this value, geometric distortion and convergence distortion can be stably and accurately adjusted automatically.

According to the fourteenth and sixteenth aspects of the present invention, by adding detection signals obtained from a plurality of photodetecting elements, even if the display position of the test pattern is largely displaced, the display can be easily performed. The position can be detected. Further, by subtracting the detection signal from each detection element, the error in the display position can be accurately calculated. By using this value, geometric distortion and convergence distortion can be stably and accurately adjusted automatically. In addition, it is possible to prevent adverse effects of unnecessary light that is incident on the light detection element.

According to the seventeenth to nineteenth aspects of the present invention, first, the converging operation of only the detection region of the photo-detecting element installed in the peripheral portion of the screen is completed. Next, by performing a convergent operation on the entire screen to correct geometric distortion and convergence, it is possible to automatically and stably adjust image distortion without disturbing the image on the effective screen.

Further, according to the invention of claims 20 to 23 of the present application, the amount of positional deviation for each lapse of time is detected from the test pattern projected on the photodetection element, and this detection signal and the photodetection element are used. By creating the correction signal in synchronization with the detection signal, drift correction of image distortion can be realized with high accuracy.

According to the invention of claims 24 to 26 of the present application, the display position of the test pattern for position detection (for signal search) and position detection for error detection is utilized by utilizing the position / voltage conversion characteristic. Detect. This makes it possible to correct image distortion with high accuracy in a short time using a simple test pattern.

According to the twenty-seventh to thirtieth inventions of the present application, the display position of the test pattern is calculated from the output ratio of the photodetector. By doing so, the influence of the gain variation of the test pattern and other variation factors is less likely to occur, and the direction and the amount of deviation of the test pattern can be directly detected, so that the image distortion can be detected with high accuracy in a short time.

According to the inventions of claims 31 to 34 of the present application, the display position of the test pattern is directly calculated from the output ratio of the luminance level when the display position of the test pattern is shifted. This makes it possible to detect the image distortion with high accuracy and in a short time with a simple configuration.

Further, according to the invention of claims 35 to 38 of the present application, by using the test pattern having the irradiation area narrower than the light receiving range of the photodetector, it is unnecessary from the photodetector element in the portion where only the unnecessary light is incident. The light component can be detected. By doing this, the display position of the test pattern can be calculated with high accuracy by subtracting this unnecessary light component from the output of each photodetecting element. Therefore, unnecessary light such as reflected light and external light inside the projection device set can be removed, and stable and highly accurate image distortion can be detected.

Further, according to the inventions of claims 39 and 40 of the present application, the average value of the video signal and the test pattern are switched and output, and the positional deviation amount of the test pattern is calculated to generate the image distortion correction signal. I am trying. In this way, the test pattern insertion operation becomes inconspicuous when performing multi-scan and multi-aspect image distortion correction, and the image distortion can be automatically adjusted with high accuracy.

Further, according to the inventions of claims 41 to 43 of the present application, the display position of the test pattern is controlled, and the correction signal of the image distortion is generated from the detection signal and the control amount. In this way, the test pattern can be searched with a small number of times, and the efficiency of the search and the adjustment time can be shortened.

Further, according to the inventions of claims 44 and 45 of the present application, the projection distance to the detection portion is calculated from the brightness level of the test pattern, and the correction signal of the image distortion is created from this calculation signal and the detection signal. This allows accurate automatic adjustment of image distortion even when the photodetector is arranged on the non-imaging surface as in a multi-screen display.

According to the 46th and 47th aspects of the present invention, the projection distance to the detecting portion is calculated from the brightness level of the test pattern, and the phase of the test pattern is controlled by this calculation signal to correct the image distortion. I am trying to create. This makes it possible to detect the position on the actual non-imaging surface, and more accurate automatic adjustment of image distortion can be performed.

In the inventions of all claims of the present application,
A low-cost optical device such as a photodiode can be used as the light detection element. For example, an image distortion correction device can be realized at a lower cost than that using an optical device such as a CCD sensor, and its practical effect is great.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a projection display including a position detection device according to a first embodiment of the present invention.

FIG. 2 is an internal configuration diagram of a projection display in each example.

FIG. 3 is a block diagram showing a configuration of a position detection device of a first embodiment.

FIG. 4A is a plan view showing the positional relationship between the photodetector and the screen of the first embodiment, and FIG. 4B is a luminance distribution diagram of a test pattern.

FIG. 5 is an explanatory diagram showing the operating principle of the position detecting device of the first embodiment.

FIG. 6 is a luminance distribution diagram of a test pattern (No. 1) of the first embodiment.

FIG. 7 is a luminance distribution diagram of a test pattern (No. 2) of the first embodiment.

8A and 8B show an example of geometric distortion of a display screen, and FIG. 8C is a correction waveform diagram thereof.

FIG. 9 is a diagram (No. 1) of geometric distortion and its correction waveform in the projection display.

FIG. 10 is a geometrical distortion diagram (2) of the geometric distortion in the projection display.

FIG. 11 is a block diagram of a correction signal generation circuit used in the position detection device of the first embodiment.

FIG. 12 is a diagram (part 1) of various correction waveforms used in each embodiment of the present invention.

FIG. 13 is various correction waveform diagrams (No. 2) used in each embodiment of the present invention.

FIG. 14 is a diagram (part 3) of various correction waveforms used in each embodiment of the present invention.

FIG. 15 is a signal waveform diagram of a serial data creation circuit used in the position detection device of the first embodiment.

FIG. 16 is a configuration diagram of a projection type display including a position detection device according to a second embodiment of the present invention.

FIG. 17A is a plan view showing the positional relationship between the photodetector and the screen of the second embodiment, and FIG. 17B is a luminance distribution diagram of the test pattern.

FIG. 18 is an explanatory diagram showing the operating principle of the position detecting device of the second embodiment.

FIG. 19 is a block diagram showing a configuration of a position detection device according to a second embodiment.

FIG. 20 is a luminance distribution diagram of a test pattern of the second embodiment.

FIG. 21 is a configuration diagram of a projection display including a position detecting device according to a third embodiment of the invention.

FIG. 22A is a plan view showing the positional relationship between the photodetector and the screen of the third embodiment, and FIG. 22B is a luminance distribution diagram of the test pattern (No. 1).

FIG. 23 is a luminance distribution diagram (2) of the test pattern of the third example.

FIG. 24 is a configuration diagram of a photodetector section according to a third embodiment.

FIG. 25 is a block diagram showing a configuration of a position detection device of a third embodiment.

FIG. 26 (a) is a layout view of photo-detecting elements arranged in a grid pattern in the third embodiment, and FIG. 26 (b) is an explanatory view showing coordinate conversion in the third embodiment.

FIG. 27 is a diagram showing the structure of the photodetector section of the third embodiment.
(C) is a layout of photodetectors in an L-shaped lattice array,
(D) is a layout view of the photodetecting elements in an inverted L-shaped lattice array,
(E) is a layout view of cross-shaped lattice-shaped photodetector elements,
(F) is a layout view of the photo-detecting elements in an X-shaped lattice array.

FIG. 28 is a configuration diagram of a projection type display including an image correction device according to a fourth example of the present invention.

FIG. 29 is a luminance distribution diagram of the test pattern of the fourth example.

FIG. 30 is a configuration diagram of a position calculation unit and an error calculation unit in the fourth embodiment.

FIG. 31 is an operation waveform diagram of a position calculating unit and an error calculating unit in the fourth example.

FIG. 32 is a characteristic diagram of a position detection signal in the fourth embodiment.

FIG. 33 is a configuration diagram of a projection display including an image correction device according to a fifth embodiment of the present invention.

FIG. 34 is a plan view showing the positional relationship between the photodetector and the screen in the fifth embodiment.

FIG. 35 is a characteristic diagram showing the operation of the position calculation unit and the error calculation unit of the fifth embodiment.

FIG. 36 is an explanatory diagram (part 1) of the converging operation of the image correction apparatus of the fifth embodiment.

FIG. 37 is an explanatory diagram (part 2) showing the converging operation of the image correction device of the fifth embodiment.

FIG. 38 is a configuration diagram of a projection display including an image correction device according to a sixth embodiment of the present invention.

FIG. 39 is a configuration diagram of a position calculation unit and an error calculation unit in the sixth embodiment.

FIG. 40 is an operation waveform diagram of the position calculating unit and the error calculating unit in the sixth embodiment.

FIG. 41 is a plan view showing the arrangement of photodetection units according to the sixth embodiment.

FIG. 42 is a configuration diagram of a projection display including an image correction device according to a seventh embodiment of the present invention.

FIG. 43 is a block diagram showing the relationship between the position calculation unit, the error calculation unit, and the correction signal generation circuit of the seventh embodiment.

FIG. 44 is a plan view showing the arrangement of photodetection elements according to the seventh embodiment.

FIG. 45 is an operation waveform diagram of the correction signal generation circuit of the seventh embodiment.

FIG. 46 is an explanatory diagram showing a procedure of test pattern error detection and convergence operation in the image correction apparatus of the seventh embodiment.

FIG. 47 is a configuration diagram of a projection type display including an image correction device according to an eighth embodiment of the present invention.

FIG. 48 is a block diagram showing the relationship between the position calculation unit, the error calculation unit, and the correction signal generation circuit of the eighth embodiment.

FIG. 49 is a characteristic diagram of the position calculation unit, the error calculation unit, and the correction signal generation circuit of the eighth embodiment.

FIG. 50 is a configuration diagram of a projection type display including an image correction device according to a ninth embodiment of the present invention.

FIG. 51 is a circuit diagram showing a configuration of a position calculation unit of the ninth embodiment.

FIG. 52 is an operation characteristic diagram of the position calculation unit of the ninth embodiment.

FIG. 53 is an operation waveform diagram of the position calculation unit of the ninth embodiment.

FIG. 54 is a configuration diagram of a projection display including a position detection device according to a tenth embodiment of the present invention.

FIG. 55 is a configuration diagram of a photo-detecting section according to the tenth embodiment.

FIG. 56 is a configuration diagram of a position calculation unit of the tenth embodiment.

57A is a plan view showing the positional relationship between the photodetector and the screen of the tenth embodiment, FIG. 57B is a luminance distribution diagram of a test pattern (No. 1), and FIG. 57C is a luminance of the test pattern. It is a distribution map (the 2).

FIG. 58 is a plan view showing the positional relationship between the photodetector and the test pattern in the position calculating operation of the tenth embodiment, and a luminance distribution diagram of the test pattern.

FIG. 59 is a configuration diagram of a projection type display including a position detection device according to an eleventh embodiment of the present invention.

FIG. 60 is a configuration diagram of a display position control unit of the eleventh embodiment.

FIG. 61 is a plan view showing the positional relationship between the photodetector and the test pattern in the position calculating operation of the eleventh embodiment, and a luminance distribution diagram of the test pattern.

FIG. 62 is a configuration diagram of a projection type display including a position detection device according to a twelfth embodiment of the present invention.

FIG. 63 is a configuration diagram of a photodetector section in a twelfth embodiment.

FIG. 64 is a configuration diagram of an unnecessary light removing unit according to the twelfth embodiment.

FIG. 65 is a configuration diagram of a minimum value calculation circuit in an unnecessary light removing unit according to the twelfth embodiment.

66A is a plan view showing the positional relationship between the photodetector and the test pattern in the position calculating operation of the twelfth embodiment, and a luminance distribution diagram of the test pattern, and FIG. 66B is for reducing unnecessary light. FIG. 3C is a configuration diagram of the light shielding portion of FIG.

FIG. 67 is a configuration diagram of a projection type display including an image correction device according to a thirteenth embodiment of the present invention.

68A is a plan view showing a normal display screen of the thirteenth embodiment, and FIG. 68B is a plan view showing a display screen of a video signal and a test pattern at the time of correction.

FIG. 69 is a plan view showing a display screen on which a test pattern is superimposed in the thirteenth embodiment.

FIG. 70 is an explanatory diagram showing the states of the display screen at the normal time and the correction time in the thirteenth embodiment.

FIG. 71 is a configuration diagram of a projection display including an image correction device in a fourteenth embodiment of the present invention.

72 is a plan view showing the positional relationship between the photodetector and screen of the fourteenth embodiment. FIG.

FIG. 73 is a plan view showing the positional relationship between the photodetector and the test pattern in the display position control operation of the fourteenth embodiment.

FIG. 74 is a plan view (1) showing the positional relationship between the photodetector and the test pattern in the search operation on the screen cross in the fourteenth embodiment.

FIG. 75 is a plan view (No. 2) showing the positional relationship between the photodetector and the test pattern in the search operation on the screen cross in the fourteenth embodiment.

FIG. 76 is a plan view showing the positional relationship between the photodetector and the test pattern in the search operation for the peripheral portion of the screen according to the fourteenth embodiment.

77 is a flowchart (No. 1) showing the search operation of each part of the screen in the fourteenth embodiment. FIG.

FIG. 78 is a flowchart (No. 2) showing the search operation of each part of the screen in the fourteenth embodiment.

FIG. 79 is a configuration diagram of a projection type display including an image correction device according to a fifteenth embodiment of the present invention.

FIG. 80 is a basic configuration diagram of a multi-screen projection display according to the fifteenth embodiment.

FIG. 81 is a configuration diagram of the multi-screen projection display of the fifteenth embodiment when the photodetector is installed on the non-imaging surface.

82A is a plan view showing the positional relationship between the light detection unit and the window pattern in the projection distance calculation operation of the fifteenth embodiment, and FIG. 82B is a characteristic diagram showing the relationship between the projection distance and the brightness level. Is.

FIG. 83 is a plan view showing the arrangement of photodetectors in the multi-screen display of the fifteenth embodiment.

FIG. 84 is a configuration diagram of a projection type display including an image correction device in a sixteenth embodiment of the present invention.

FIG. 85 is a plan view of the display device, in which the photodetection unit of the sixteenth embodiment is installed, seen from above.

FIG. 86 (a) is a plan view of the original test pattern,
(B)-(c) is a top view of the test pattern by which the display position was controlled.

FIG. 87 is a block diagram showing a configuration example of a conventional position detection device.

FIG. 88 is a block diagram of an image correction apparatus used in a conventional magnifying projection apparatus.

[Explanation of symbols]

1, 222, 600, 640, 670, 711, 73
0,770,800 Test pattern generation circuit (TP generation circuit) 2,120,123,167,182,187,71
2,713 Switching circuit 3 Video circuit 4 CRT 5 Lens 6 Mirror 7 Screen 8-15, 100-107, 170-177, 601-
608, 671-678, 690, 691, 692, 7
15-722, 732-739, 771-778, 80
2 to 809 Photodetector 16,609,650,679,723,740,77
9,810 Multiplexer 17,78,88,89,220,610,681,7
24, 741, 781, 812 Position calculation section 18, 118, 221 Error calculation section 19, 119 Correction signal generation circuit 20 Convergence correction circuit (C correction circuit) 21 Deflection circuit 22 Convergence yoke (CY) 23 Deflection yoke (DY) 24 Enlargement projection device 25 Automatic adjustment device 26, 28, 69 Position detection device 29, 641, 731, 801 Display position control unit 30-32, 70-77, 130-145, 620, 6
21, 642-649 photodetector elements 33-35, 39, 165, 183, 190-198,
622, 623, 651, 693 to 695 Peak hold circuit (PH circuit) 36, 37 Differential circuit 38, 121, 125, 168, 184, 199 to 20
7,624,625,652,696 ~ 698 A / D
Converter 40-47, 80-87, 90-97, 110-11
7,150 to 157,631,632 Test pattern 50,51 Input terminal 52 Correction waveform generation circuit 53 to 64 Multiplying D / A converter 65 Serial data creation circuit 108 Addition / subtraction processing unit 122 Coordinate calculation circuit 127 Test pattern display phase Control circuit 146 Temperature detection circuit 147 Timer circuit 160,700-702 Subtractor 161 Maximum value detection circuit 162 Minimum value detection circuit 163,208,628,629 Adder 166 Binarization circuit 180,181 Subtraction circuit 185 Error detection circuit 186 , 189 Correction signal creation circuit 188 Drive circuit 209-217,630 Divider 243-245 Operator 260-262 Operational amplifier 626,627 Coefficient ROM 653 CPU 663 Address generator 660 ROM 661 D / A converter 662,710 Low range Communication Over-filter (LPF) 680 Unnecessary light removal unit 699 Minimum value calculation circuit 703,705 Comparator 704,706 Selector 714 Timing generation unit 780,811 Projection distance calculation unit 782,783 Projection display 784 Display screen 785-787 Projection tube 788- 795 Window pattern 790 Light shield

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[Procedure amendment]

[Submission date] June 20, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Fig. 86

[Correction method] Change

[Correction content]

FIG. 86 (a) is a plan view of an original test pattern,
(B)-( d ) is a top view of the test pattern by which the display position was controlled.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location H04N 9/28 A 9/31 A

Claims (47)

[Claims] 1. A position detection device for detecting a display position of a test pattern displayed on a display screen, the position detection device being provided on an outer peripheral portion of the display screen and having a plurality of photodetection elements at least along one direction of the display screen. A plurality of photodetectors arranged close to each other and a test pattern whose signal level changes along the arrangement direction of the photodetector of the photodetector are generated at a position where the photodetector can receive light. A position detecting device comprising: a means and a pattern position calculating means for calculating a display position of the test pattern from a signal level received by a light detecting element of the light detecting section. 2. The position detecting apparatus according to claim 1, wherein the test pattern generating means generates a test signal having a ridge-shaped luminance distribution having symmetry. 3. The pattern position calculating means determines the display position of the test pattern from the level and inclination of the received light signal when the test pattern generating means generates a test signal having a symmetric mountain-shaped luminance distribution. The position detecting device according to claim 1, wherein the position detecting device calculates the position. 4. The pattern position calculation means uses a dark signal level obtained by all the photodetectors when the test pattern is not projected and a bright signal level obtained from a high-brightness pattern of the test pattern,
2. The position detection device according to claim 1, wherein the test pattern is displayed and the display position of the test pattern is calculated after the photoelectric detection elements are corrected to have the same photoelectric sensitivity. 5. A position detection device for detecting a display position of a test pattern displayed on a display screen, comprising: a plurality of photodetection elements arranged at predetermined positions on an outer peripheral portion of a video display screen; Test pattern generating means for generating a test pattern that changes along the plane of the display screen, and display position control for controlling the display position of the test pattern generated by the test pattern generating means within a range that can be received by the photodetector. And a pattern position calculation unit that calculates the display position of the test pattern from the signal level received by the photodetector and the control amount of the display position control unit. . 6. The position detecting device according to claim 5, wherein the test pattern generating means generates a test signal having a ridge-shaped luminance distribution having symmetry. 7. The pattern position calculation means, when the test pattern generation means generates a test signal having a symmetrical luminance distribution of a mountain shape, a level of a light reception signal and a control amount of the display position control means. The position detecting device according to claim 5, wherein the display position of the test pattern is calculated from the above. 8. A position detecting device for detecting a display position of a test pattern displayed on a display screen, wherein the position detecting device is provided on an outer peripheral portion of an image display screen and has a plurality of photodetection elements arranged along the display screen. A plurality of photodetectors arranged adjacent to each other, a test pattern having an irradiation range smaller than the light-receiving region of each photodetector, a test pattern generating means for generating a position at which the photodetector can receive light, Pattern position calculating means for calculating the display position of the test pattern by assigning two-dimensional coordinates on the display screen to each photodetecting element and weighting and adding the outputs of the photodetecting elements with the assigned coordinates. A position detecting device comprising: 9. The pattern position calculation means sets the two-dimensional plane coordinates on the display screen assigned to each photodetector as (x1, y1), (x2, y2), ... (xn, yn), respectively. Let Z1, Z2, ..., Zn be the normalized output of each photodetector, and use the following equation: 9. The position detecting device according to claim 8, wherein the display position (x, y) of the test pattern is calculated according to. 10. An image correction device for detecting a display position of a test pattern for detecting image distortion and correcting image distortion when an image is displayed on the display screen, the image correction device being provided on an outer peripheral portion of the display screen. A plurality of photo-detecting sections in which a plurality of photo-detecting elements are arranged close to each other along one direction of the display screen, and test patterns for position detection and error detection are generated at positions where the photo-detecting elements can receive light. Test pattern generation means, pattern position calculation means for calculating the display position of the test pattern from the signal level received by the photodetector, and geometric distortion and convergence error as image distortion from the signal of the pattern position calculation means. Error calculating means for calculating the correction direction of the image, and correction signal creating means for creating a signal for correcting the error of the image distortion from the output of the error calculating means, Image correction apparatus characterized by comprising. 11. The test pattern generating means includes a first test pattern having a large display area as a position detection signal and a signal level change, and a light detection having a small display area as an error detection signal and adjacent light detection. 11. A second test pattern having a luminance of a line width smaller than the element pitch is generated.
The image correction device described. 12. An image correction device for correcting image distortion by detecting a display position of a test pattern for detecting image distortion when an image is displayed on the display screen, wherein the four corners of the image display screen are horizontal and horizontal. A plurality of photo-detecting elements are arranged obliquely with respect to the vertical scanning direction, a plurality of photo-detecting elements are arranged in the horizontal scanning direction in the outer peripheral portion of the long side of the display screen, and a vertical direction in the outer peripheral portion of the short side of the display screen. A plurality of photodetector sections in which a plurality of photodetector elements are arranged in the scanning direction, a test pattern generating means for generating a test pattern at a position where the photodetector elements can receive light, and a signal level received by the photodetector elements A pattern position calculating means for calculating the display position of the test pattern, and an error for calculating the correction direction of the geometrical distortion as the image distortion and the convergence error from the signal of the pattern position calculating means. Calculating means and the image correction apparatus characterized by comprising a correction signal generating means for generating a signal for correcting the error of the image distortion from the output of said error calculating means. 13. The pattern position calculating means calculates position information corresponding to a light receiving position of the photodetecting element by using a position / voltage signal converted into voltage information. The image correction device described. 14. An image correction device for detecting a display position of a test pattern for detecting image distortion and correcting the image distortion when an image is displayed on the display screen, wherein a plurality of light detection devices are provided on an outer peripheral portion of the display screen. A plurality of photo detectors in which the elements are arranged, a test pattern generating unit that generates a test pattern at a position where the photo detectors can receive light, based on a value obtained by adding and subtracting signals received by the photo detectors, Pattern position calculating means for calculating the display position of the test pattern; error calculating means for calculating the correction direction of the geometrical distortion as image distortion and the convergence error from the signal of the pattern position calculating means; An image correction apparatus comprising: a correction signal creating unit that creates a signal for correcting the error of the image distortion from the output. 15. The photo-detecting section has a plurality of photo-detecting elements arranged obliquely with respect to horizontal and vertical scanning directions of an image at four corners of a display screen of an image, and at a peripheral portion of a long side of the display screen. 15. The image correction according to claim 14, wherein a plurality of photodetection elements are arranged in a horizontal scanning direction, and a plurality of photodetection elements are arranged in a vertical scanning direction on an outer peripheral portion of a short side of the display screen. apparatus. 16. The pattern position calculating means detects the projected position of the test pattern with a low resolution based on the added value of the outputs of the adjacent photodetector elements, and the corrected signal generating means detects the projected position of the test pattern. 15. The image correction apparatus according to claim 14, wherein after the image is roughly corrected, the projected position of the test pattern is detected again with high resolution based on the difference value between the adjacent photodetection elements. 17. An image correction apparatus which corrects image distortion by detecting a display position of a test pattern for detecting image distortion when an image is displayed on the display screen. A plurality of photodetector sections in which photodetector elements are arranged, a test pattern generating means for generating a test pattern at a position where the photodetector elements can receive light, and a display position of the test pattern depending on the signal level received by the photodetector elements. A pattern position calculating means for calculating, from the signal of the pattern position calculating means, an error calculating means for calculating a geometric distortion as image distortion and a correction direction of a convergence error, and an output of the error calculating means, A peripheral portion correction signal generating means for generating a correction signal only for a peripheral portion of a screen and a correction waveform from the peripheral portion correction signal generating means An image correction apparatus comprising: a full-screen correction signal creation unit that drives the image correction unit to converge the display position of the test pattern and creates a correction signal for the entire screen based on the convergence result. 18. The photodetection unit has a plurality of photodetection elements arranged obliquely with respect to horizontal and vertical scanning directions of an image at four corners of a display screen of an image, and at a peripheral portion of a long side of the display screen. 18. The image correction according to claim 17, wherein a plurality of photodetection elements are arranged in a horizontal scanning direction, and a plurality of photodetection elements are arranged in a vertical scanning direction on an outer peripheral portion of the short side of the display screen. apparatus. 19. The pattern position calculation means detects a projected position of a test pattern with a low resolution based on an added value of outputs of adjacent photodetection elements, and a corrected signal generation means detects a projected position of the test pattern. 18. The image correction apparatus according to claim 17, wherein after the image is roughly corrected, the projected position of the test pattern is detected again with high resolution based on the difference value between the adjacent photodetection elements. 20. An image correction apparatus for detecting a display position of a test pattern for detecting image distortion and correcting image distortion when an image is displayed on the display screen, wherein a plurality of image correction devices are provided on an outer peripheral portion of a video display screen. A plurality of photodetector sections in which photodetector elements are arranged, a test pattern generating means for generating a test pattern at a position where the photodetector elements can receive light, and a display position of the test pattern depending on the signal level received by the photodetector elements. A pattern position calculating means for calculating the correction direction of the geometrical distortion as image distortion and the convergence error for each predetermined time from the signal of the pattern position calculating means, and the output of the error calculating means An image correction apparatus, further comprising: a correction signal creating unit that creates a signal for correcting the image distortion error. 21. The correction signal creating means creates a correction signal in synchronization with a signal from the photodetection section, based on an elapsed time after power-on of the image display device and an internal temperature of the device. 21. The image correction device according to claim 20. 22. The image correction according to claim 20, wherein the photodetector outputs a position / voltage conversion signal in which position information corresponding to the light receiving position of the test pattern is voltage-converted. apparatus. 23. The correction signal generating means periodically generates a correction signal in synchronization with the elapsed time of the image display device and the temperature in the set when the test pattern is not received by the photodetector. 21. The image correction device according to claim 20, wherein 24. An image correction device for correcting the image distortion by detecting the display position of a test pattern for detecting the image distortion when the image is displayed on the display screen. A plurality of photodetector parts in which photodetector elements are arranged, a test pattern generating means for generating a test pattern at a position where the photodetector elements can receive light, and position information corresponding to the light receiving position from the photodetector elements is voltage information. Pattern position calculating means for calculating the display position of the test pattern from the position / voltage conversion signal converted to the error, and an error for calculating the correction direction of the geometrical distortion as image distortion and the convergence error from the signal of the pattern position calculating means. And a correction signal generating means for generating a signal for correcting the image distortion error from the output of the error calculating means. Image correction device. 25. When detecting the position of the test pattern, the pattern position calculation means performs a detection process with a position / voltage conversion characteristic that linearly changes over the installation distance of a plurality of photodetection elements, and the error of the test pattern is detected. In detection,
25. The image correction apparatus according to claim 24, wherein the detection processing is performed with a time / voltage conversion characteristic that linearly changes within a range shorter than the installation interval of the photodetection elements at the convergence point. 26. The test pattern generating means outputs a crosshatch signal having a large display area for position detection,
25. The image correction device according to claim 24, wherein the error correction is for generating a crosshatch signal having a small display area. 27. A position detection device for detecting a display position of a test pattern displayed on a display screen, comprising: a plurality of photodetection parts in which a plurality of photodetection elements are adjacently arranged on an outer peripheral portion of the display screen. , A test pattern generating means for generating a linear test pattern whose signal level changes in the width direction at a position where the photodetector can receive light, and coordinates on the display screen for each photodetector in the photodetector. Pattern position calculating means for calculating the display position of the test pattern by weighting and adding the output ratios of the respective photodetecting elements with the coordinates assigned to the respective photodetecting elements. Position detection device. 28. The pattern position calculation means divides the output of each photodetector element of the photodetector by the sum of the outputs of all photodetector elements in the photodetector to obtain an output ratio of each photodetector. 28. The position detecting device according to claim 27, wherein the display position of the test pattern is calculated by calculating and adding weighted with the coordinates assigned to each photodetecting element. 29. The test pattern generating means generates a linear test pattern having a luminance distribution symmetrical in a widthwise direction on at least two or more photodetection elements in the photodetection section. 28. The method according to claim 27, wherein
The position detection device described. 30. The photo-detecting section has photo-detecting elements arranged in a straight line oblique to the scanning direction of the display screen, and the test pattern generating means has a luminance distribution in the scanning direction of the display screen. 28 is a line-shaped test pattern that is symmetric with respect to a mountain.
The position detection device described. 31. A position detecting device for detecting a display position of a test pattern displayed on a display screen, comprising: a plurality of photodetector elements arranged on an outer peripheral portion of the display screen; and a signal level varying in a width direction. Test pattern generating means for generating a linear test pattern at a position where the photodetector can receive light, and display position control for finely moving the display position of the test pattern generated by the test pattern generating means within a pattern width in a time division manner. Means for calculating the output ratio of each detection signal output from the photodetector in a time division manner, and adding the output ratio by weighting with the movement amount of the test pattern output from the display position control means A position detecting device comprising: a pattern position calculating means for calculating a display position of the pattern. 32. The pattern position calculating means temporarily stores each signal level detected by the photodetector in a time division manner, and divides each stored signal level by the sum of all signal levels to obtain an output ratio. 32. The position detecting device according to claim 31, wherein the display position of the test pattern is calculated by multiplying the output ratio by the moving amount of the test pattern. 33. The display position control means controls the fine movement range of the test pattern in a time division manner within a range of a half of the width of the test pattern. Position detection device. 34. The position detecting apparatus according to claim 32, wherein the test pattern generating means generates a linear test pattern having a luminance distribution symmetrical in a widthwise direction. 35. A position detecting device for detecting a display position of a test pattern displayed on a display screen, comprising: a plurality of photodetecting parts in which a plurality of photodetecting elements are arranged adjacent to each other on an outer peripheral part of the display screen. A test pattern generating means for generating a width of the test pattern to be smaller than a light receiving area of the photodetector when irradiating the photodetector with a linear test pattern whose signal level changes in the width direction, An output of the minimum value calculation unit from a minimum value calculation unit that detects the minimum value of the output of each photo detection element in the photo detection unit as an unnecessary light level, and an output of each photo detection element in the photo detection unit. Pattern position calculation for calculating the display position of the test pattern from a plurality of difference means for respectively subtracting and the output of the difference means corresponding to each photodetection element in the photodetection section. Position detecting device characterized by comprising a means. 36. The pattern position calculation means assigns coordinates on the display screen to the respective photodetection elements in each of the photodetection sections, and outputs each output of the difference means corresponding to each photodetection element to a total difference means. Is calculated by dividing the output ratio of each difference means by dividing by the total sum of the outputs of the above, and the display position of the test pattern is calculated by weighting and adding the coordinate value on the display screen to this output ratio. 36. The position detecting device according to claim 35. 37. The photo-detecting unit is one in which the photo-detecting elements are arrayed in a straight line oblique to the scanning direction of the display screen, and the test pattern generating means produces a luminance distribution symmetrical in a width direction in the width direction. 36. The position detecting device according to claim 35, which generates a linear test pattern. 38. The photo-detecting section includes a photo-detecting element having a narrow directional characteristic, and a light-shielding section for shielding unnecessary light around the photo-detecting element. The position detection device according to claim 35. 39. An image correction apparatus which corrects image distortion by detecting a display position of a test pattern for detecting image distortion when an image is displayed on the display screen. A plurality of photodetection sections in which the detection elements are arranged adjacent to each other, a test pattern generating means for generating a linear test pattern whose signal level changes in the width direction at a position where the photodetection elements can receive light, and an input image signal An image averaging means for averaging levels at least in field units, a first switching means for switching between the output of the image averaging means and the test pattern output by the test pattern generating means, and the first switching means. Second switching means for switching between the output and the input image signal, and switching to the output of the first switching means by using the second switching means during image correction, and the display screen Timing for giving the switching timing signal to the first switching means so that the output image of the image averaging means is displayed in the effective display range of the above and the test pattern of the test pattern generating means is displayed on the outer peripheral portion of the display screen. Generating section, the coordinates on the display screen for each photodetector in the photodetector is assigned, the output ratio of each photodetector, by weighted addition by the coordinates assigned to each photodetector, A pattern position calculating means for calculating the display position of the test pattern, an error calculating means for calculating the correction direction of the geometrical distortion and the convergence error of the image from the signal of the pattern position calculating means, and an image from the output of the error calculating means. An image correction apparatus, comprising: a correction signal creating unit that creates a signal for correcting a distortion error. 40. When the input image is different from the effective display range of the display screen, the timing generator displays the output of the image averaging means on the display screen when correcting the image, and displays the test pattern on the display screen. 40. The image correction apparatus according to claim 39, wherein the first switching means is controlled so as to be displayed on the outer peripheral portion. 41. An image correction device for detecting a display position of a test pattern for detecting image distortion and correcting image distortion when an image is displayed on the display screen, wherein a plurality of light beams are provided on an outer peripheral portion of the display screen. A plurality of photodetection sections in which the detection elements are arranged adjacent to each other, a test pattern generating means for generating a linear test pattern at a position where the photodetection element can receive light, and a linear test generated by the test pattern generating means. Display position control means for sequentially moving the display position of the pattern from the reference position to the left or right or up and down of the display screen at an integral multiple of the minimum pitch; and when the detection signal of the test pattern is obtained by the photodetector, the display Pattern position calculating means for calculating the display position of the test pattern based on the number of times of movement of the test pattern instructed by the position controlling means; Error correction means for calculating the geometric distortion as image distortion and the correction direction of the convergence error from the signal, and the correction signal generation means for generating a signal for correcting the image distortion error from the output of the error calculation means. An image correction device characterized by the above. 42. The test pattern generating means generates a grid point of the grid pattern at a position where light can be received by the photodetector when the grid pattern is a combination of linear test patterns in a grid pattern. The display position control means, when changing the display position of the lattice pattern during image correction, first performs position control so that the photodetector located on the cross of the display screen can detect the lattice pattern. Then, position control is performed so that the photodetector located at a corner of the display screen can detect the lattice pattern with a location controlled on a cross as a movement source. Is for calculating the display position of each grid point in the grid pattern from each position control amount in the display position control means. Image correction apparatus according to claim 41 wherein the. 43. The display position control means provides a display position of a test pattern to the test pattern generating means by controlling a deflecting means provided in an image display device. 41
The image correction device described. 44. A display position of a test pattern for detecting image distortion is detected when an image is displayed by a plurality of magnifying projection tubes on a multi-display screen in which a plurality of display screens are arranged vertically and horizontally. An image correction device that corrects image distortion by means of a plurality of photodetectors that are located on the side of the magnifying projection tube from each of the display screens and that have a plurality of photodetection elements arranged adjacent to each other on the radiation outer peripheral portion of each projection beam. Section, the first test pattern for calculating the projection distance and the second test pattern for detecting image distortion are the light detection when the distance between the light detection unit and the magnifying projection tube is the projection distance. Pattern generating means that is generated at a position where the light detection element of the other part can receive light, and projection distance calculation means that calculates the projection distance to the light detection part based on the signal level of the first test pattern received by the light detection element. A pattern position calculating means for calculating a display position of the second test pattern from an output of the light detecting element of each of the light detecting sections and an output of the projection distance calculating means, and an image distortion from a signal of the pattern position calculating means. Error calculation means for calculating the correction direction of the geometrical distortion and convergence error, and correction signal generation means for generating a signal for correcting the image distortion error from the output of the error calculation means. Image correction device. 45. The test pattern generating means includes a window pattern for calculating a projection distance having a constant brightness value as the first test pattern, and a brightness pattern as a grid pattern in the display screen as the second test pattern. 45. The image correction apparatus according to claim 44, wherein a crosshatch pattern for detecting image distortion that changes in the order of 1 is sequentially generated. 46. A display position of a test pattern for detecting image distortion is detected when an image is displayed by a plurality of magnifying projection tubes on a multi-display screen in which a plurality of display screens are vertically and horizontally arranged. An image correction device that corrects image distortion by means of a plurality of photodetectors that are located on the side of the magnifying projection tube from each of the display screens and that have a plurality of photodetection elements arranged adjacent to each other on the radiation outer peripheral portion of each projection beam. Section, the first test pattern for calculating the projection distance and the second test pattern for detecting image distortion are the light detection when the distance between the light detection unit and the magnifying projection tube is the projection distance. Pattern generating means that is generated at a position where the light detection element of the other part can receive light, and projection distance calculation means that calculates the projection distance to the light detection part based on the signal level of the first test pattern received by the light detection element. Display position control means for finely moving the display position of the second test pattern based on the output of the projection distance calculation means, and display of the second test pattern from the output of the photodetection element of each photodetection section. Pattern position calculation means for calculating the position, error calculation means for calculating the correction direction of the geometrical distortion as image distortion and convergence error from the signal of the pattern position calculation means, and the error of the image distortion from the output of the error calculation means An image correction apparatus comprising: a correction signal creating unit that creates a signal for correcting the image. 47. The test pattern generating means includes a window pattern for calculating a projection distance having a constant brightness value as the first test pattern, and a brightness value as a grid pattern in the display screen as the second test pattern. 47. The image correction apparatus according to claim 46, which sequentially generates a crosshatch pattern for detecting the image distortion that changes to.