JPH0638249A - Picture position measurement instrument - Google Patents

Abstract

PURPOSE:To easily attain the calibration method detecting correction quantity of mis-convergence in a numeral in the unit of length by detecting the number of a picture element corresponding to an edge length of a valid pattern on an image memory. CONSTITUTION:A cross hatched pattern on a screen 5 of a television receiver 4 is picked up by an image pickup device 7 and fetched by an image memory 10. Then picture data in the upper/lower and left/right directions from the center of the valid pattern fetched in the memory 10 are read under the control of a microprocessor 13. Then a rapid changing point of the picture data is detected and how many picture elements of an image length on the X axis and of an image length on the Y axis are in existence in the memory are obtained. The processor 13 uses the number of the picture element and the screen length of the CRT inputted in advance to obtain how many millimeters on a CRT screen one picture element of the memory 10 corresponds. One picture element length in the X and Y axes in the memory 10 is detected and the length is stored in a correction data storage section 17. The correction data are converted into the measured mis-convergence.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image position measuring device suitable for measuring distortion of an image projected on an image device, particularly a television receiver, or convergence, and more particularly, it relates to misconvergence. At the time of correction, the correction amount can be output as a dimension on the tube surface.

[0002]

2. Description of the Related Art Conventionally, a television receiver using a color cathode ray tube, which has been most popularly used as an image device, has a static and It is an indispensable requirement to perform dynamic image distortion correction and misconvergence correction.

In recent years, such convergence correction has been
An imaging device, such as a TV camera, is installed at a position that opposes the tube surface of the TV receiver on the measured side, and the specific pattern projected by this TV camera is loaded into the image memory and the pattern projected is specified. Calculate the barycentric position of the electron beam irradiating the position,
An image position measuring device has been developed which measures misconvergence by examining whether or not the position matches a predetermined position.

The image position measuring device shown in FIG.
The applicant of the present invention has previously proposed it as Japanese Patent Laid-Open No. 1-204594, in which a television receiver 4 serving as a device to be measured has a video circuit 3 for supplying a video signal to a CRT 1, a deflection yoke 2 and a CRT 1. It is provided. 7 is a CRT
A photographing device for photographing the tube surface 5 of 1, such as a television camera is shown, and an optical lens 6 is provided on the front side, and a photographing element 8 made of CCD or MOS or the like into which photographing light is incident is provided.

The video output signal of the photographing device 7 is taken into the image memory 10 through the analog-digital converter 9. A reference numeral 11 reads out the video data taken in the image memory 10 for each pixel by the address data from the timing signal generating circuit 16 and calculates the sum of the address data in a predetermined range and the product sum of the brightness levels to obtain the electron beam. This is an arithmetic circuit that determines the position of the center of gravity, and the output data of this arithmetic circuit 11 is sequentially stored in the memory 12.
The pattern signal generation circuit 15 supplies a lattice-shaped crosshatch pattern signal to the above-mentioned television receiver 1 as shown in FIG. 9, for example.

The arithmetic unit 11, the memory 12, the pattern signal generation circuit 15, and the timing signal generation circuit 16 are controlled by the control data output from the microprocessor 13, and are located on the memory at the cross points of the cross hatch pattern. The data is detected, and the measurement result is sent to the monitor 14 so that the state of image distortion and convergence can be displayed by graphic and character data. Each cross point P11, P12, P13 of the cross hatch pattern loaded in the image memory.
The position of Pn, m is, for example, as shown in the enlarged view of FIG. 10, a horizontal measurement area (horizontal measurement area HS) and a vertical measurement area (vertical measurement area) around the cross point Pn, m. VS) is set, the data (luminance level) of each cell in each measurement area is detected, the center of gravity is calculated by calculating the center of gravity, and the position of the cell that is the center of gravity (indicated by diagonal lines) is obtained. ) Is determined horizontally and vertically.

[0007]

The image position measuring device as described above has, for example, cross hatch patterns R, G,
It is possible to detect the correction amount necessary for color convergence by taking in the three image memories for each B video signal and measuring the position shift of the cross points of the cross hatch pattern that is the maximum brightness of each R, G, B signal. it can.

However, the amount of misconvergence detected by the above-mentioned method is shown only by the address data on the image memory, and the address of the memory has no meaning as a unit. There is a problem in that it is not known how long (mm) the amount will be on the tube surface of the television receiver, and the correction amount for that can not be known accurately. In particular, when measuring the tube surface of a television receiver on the manufacturing line, the relative distance between the measured image device and the image capture device changes, and in the case of different types of television receiver, Misconvergence data shows different dimensions for each television receiver,
This is a problem when automating the convergence correction.

[0009]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention does not project an all-white screen on the CRT 1 described above in the first invention, and the effective edge of the display screen is a television camera. So that it can be loaded into the image memory. Then, the number of pixels corresponding to the edge length of the effective screen is detected on the image memory. In the second aspect of the invention, the television camera is set in the zoom-up state, for example, in the field of view so that the phosphor pitch can be identified with respect to the CRT 1, and the barycentric position of each phosphor pitch written in the image memory is measured. . Then, the number of pixels between the centers of gravity is read from the address data, and the length of one pixel is converted into a unit of mm according to the phosphor pitch length of the CRT that is input in advance. Further, the third invention provides a method useful for detecting how long one pixel length is on a CRT, particularly when the shadow mask type is used.

[0010]

Even when the relative distance between the CRT 1 and the photographing device 7 changes, or in the case of an image device having a different CRT size, the television screen corresponding to the number of pixels in the image memory is previously prepared by the above method. Top length is eg mm
Since it is possible to perform calibration that is converted and output in units, it is possible to easily perform a calibration method in which the correction amount of misconvergence is detected by a numerical value in a length unit. Therefore, the convergence adjustment amount can be appropriately performed even when the CRT size is different.

[0011]

FIG. 1 is a block diagram of an image position measuring apparatus showing an embodiment of the present invention, in which the same parts as those shown in FIG. 6 are designated by the same reference numerals. That is, the cross hatch pattern projected on the tube surface 5 of the television receiver 4 is photographed by the photographing device 7, and the image memory 1
It is taken into 0. By the way, in the first aspect of the present invention, when measuring the image output position of the CRT 1 in the image position measuring device, first, the image photographed by the photographing device 7 is at least the edge of the tube surface of the CRT 1 (the boundary line with the bezel). )
Are arranged to include. That is, the image pickup device (CCD) of the television camera is configured to include all the edges of the effective screen of the television receiver as shown in FIG.
This screen is stored in the image memory 10 as an all-white screen.

Next, the image data is read out vertically and horizontally from the center of the effective screen captured in the image memory 10 under the control of the microprocessor. And
That the image data is rapidly changed (X _L, X _R, Y
_U , Y _D ) is detected and the image length on the X axis (X _R -X
And _L), the image length on the Y-axis (Y _U over Y _D) is determined how many pixels in memory (determined by the address calculation). The microprocessor uses this number of pixels and the CRT tube surface length (X-axis length L _X mm, Y-axis length L _Y mm) of the image-to-be-measured device, which has been input in advance, to set 1 in the image memory 10. How many mm the pixel (pixel) P corresponds to on the CRT tube surface is obtained by the following formula. Length of one pixel on the X-axis = L _X / (X _L -X _R ) ‥‥‥‥‥‥‥‥‥‥‥‥
(1 over 1) Y axis 1 pixel length = L _Y / _{(Y U} over Y _D) ‥‥‥‥‥‥‥
(1-2)

One pixel length in the X-axis direction and the Y-axis direction on the image memory is detected, and this value is stored in the correction data storage unit 17. This correction data converts the measurement value of misconvergence performed thereafter, that is, the number of pixels of misconvergence detected by the address data on the image memory into a measurement value indicating the length of misconvergence on the CRT screen. For example, the number of misconvergence pixels in the X-axis length is 12, and the X-axis one pixel length is CR.
If the T-tube surface is 0.05 mm, the CRT tube surface is 6 m
There will be m misconvergence.

Next, 1 for performing the above conversion
A second invention showing a method for detecting the pixel length will be described.
As shown in FIG. 3A, the camera (video camera) of the photographing device 7 is brought into close contact with the tube surface 5 of the image device to be measured, and the phosphor pitch of the CRT is changed by zooming the camera. Make sure the field of view is identifiable above. That is, as shown in FIG. 4A, in the CRT of the trinitron system, the field of view of the camera is 2 of the CRT tube surface.
The field of view is set to capture a range of 0 mm × 20 mm and has a resolution that allows the grid-like phosphor to be measured. Then, when this image is loaded into the image memory 10 and the barycentric point of a certain specific color is obtained in the X-axis direction (or the Y-axis direction), N barycentric points are arranged at a predetermined pitch Pm as shown in FIG. 4B. A point (peak point) is observed. If the number of pixels of the image sensor corresponding to the distance between the N peak points is found from the address data and the value is M, the number of pixels per pitch n is n = M / N. ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥
(2-1) By inputting the dimension (mm) of the phosphor pitch P _CRT of the CRT of the image device to be measured, the dimension L _X (mm) of one pixel length on the CRT screen is obtained by the following formula. 1 pixel length L _X (mm) = P _CRT mm / n ‥‥‥‥‥‥‥‥‥‥‥‥‥
(2-2)

In contrast to the first invention described above, the phosphor pitch of the CRT is macroscopically determined, while the second invention is
According to the invention, the length (mm) in which one pixel (pixel) of the image pickup device is displayed on the CRT tube surface is obtained by microscopically viewing the tube surface of the CRT. Although the above embodiment describes the CRT of the trinitron system, it can be applied to the CRT of the shadow mask system in which the phosphors are separated in the vertical direction. In the case of the trinitron system, C
When the direction of the RT and the pitch row of the image pickup device is set at an angle of 45 degrees, the applicant previously proposed JP-A-3-236699.
As can be seen from No. 1, the interference between the spatial frequency of the phosphor of the camera and the spatial frequency of the image pickup device of the camera can be avoided, and at the same time, the vertical pixel length L _Y can be obtained.

In the case of a shadow mask type CRT, it may not always be found when searching for a peak point indicating a specific color in the horizontal direction. Therefore, in the case of the shadow mask method, it is preferable to apply the embodiment according to the third invention described below.

As shown in FIG. 5, in the shadow mask type CRT, phosphors are separated in the vertical direction and the three primary colors are arranged in a delta shape. Therefore, when such a pattern is photographed microscopically and the center of gravity of the phosphor is searched for in the image memory as indicated by the solid arrow, the peak point cannot be found. Therefore, in the third embodiment of the present invention, first, as shown in FIG. 6, the phosphor A is first found on the image memory, and then the pixels of the image pickup device are scanned in an oblique 30 degree direction from this point. Find phosphor B. Similarly, the fluorescent substance C is found by scanning the fluorescent substance A in the oblique direction at an angle of -30 degrees.

Next, a line connecting the centers of gravity of the phosphors B and C,
An intersection point X of a line obtained by horizontally extending the center of gravity of the phosphor A is obtained. The distance between A and X is L. Once the positions of A and X are determined, it is easy to predict the position of the phosphor D from that position, and the phosphor D can be easily searched for. When the distance between X and D is L ', the pitch of the phosphors on the image memory can be calculated as (L + L') / 2. Next, the number n of pixels existing within this distance is obtained from the address, and the phosphor pitch (mm) of the CRT that is known in advance is divided by the number of pixels, and the length showing one pixel on the CRT is mm. Can be converted in units.

The above-mentioned scanning for searching for the phosphor B or the phosphor C from the phosphor A is performed on a straight line in an angle direction of 30 degrees, but as shown in FIG. 7, a zigzag pattern is formed at an angle of 30 degrees. It is possible to more reliably find the shadow mask type phosphor by scanning the phosphor.

[0020]

As described above, the image position measuring apparatus of the present invention adjusts image distortion and misconvergence by arranging a photographing camera facing an image device under measurement and by capturing a predetermined pattern in an image memory. When the image data is captured, the
A conversion value indicating how the pixel length is converted on the CRT screen is calculated, and the amount of misconvergence detected on the image memory is output by this conversion value in units of the length of the DRT screen. Even if the distance between the image-measuring device and the image-capturing device changes, the amount of misconvergence detected on the image memory will be CR.
The length on the T screen can be grasped in length units, and the adjustment can be performed accurately.

[Brief description of drawings]

FIG. 1 is a block diagram showing an outline of an image position measuring device of the present invention.

FIG. 2 is an explanation of a screen performed by a macroscopic method when converting one pixel length into a length unit on a CRT tube surface.

FIG. 3 is an arrangement of devices used in a microscopic method when converting one pixel length into a length unit on a CRT tube surface.

FIG. 4 is a diagram showing a grid-like fluorescent pitch when a tube surface of an image device under measurement is microscopically photographed.

FIG. 5 is a diagram showing a phosphor pattern when a shadow mask type CRT is microscopically photographed.

FIG. 6 is an explanatory diagram for measuring a shadow mask phosphor pitch.

FIG. 7 is an explanatory diagram for scanning a shadow mask phosphor pitch.

FIG. 8 is a block diagram showing an outline of an image position measuring device.

FIG. 9 is an explanatory diagram showing an example of a hatch pattern for measuring an image position.

FIG. 10 is an explanatory diagram for obtaining a barycenter of cross points of a hatch pattern on an image memory.

[Explanation of symbols]

 4 television receiver 7 photographing device 10 image memory 17 correction data storage means

Claims (5)

[Claims] 1. An image pickup device which is arranged so as to face the image device under test and at least completely captures a display surface of the image device under test; and an image which takes in a video signal output from the image pickup device as image data. A memory, a pattern generator that generates a predetermined video pattern signal to be supplied to the image device under measurement, and an image data stored in the image memory,
In an image position measuring device comprising a calculation means for calculating the image position of the video pattern and a timing control means, before measuring the image position, the contour edge positions in the horizontal and vertical directions of the display screen area of the image device under test are measured. Is detected on the image memory, the number of pixels between the edges is calculated, and the horizontal and vertical lengths of the display surface of the image device under measurement are input to display one pixel length of the image memory on the display screen. An image position measuring device, characterized in that it is provided with a means for converting into the above length and provided with a calibration means for outputting the distance on the CRT image corresponding to the number of pixels of the image memory in units of length. 2. An image pickup unit which is arranged so as to face the image device under measurement and which captures the display surface of the image device under measurement, and an image memory which receives the video signal output from the image pickup unit as image data. A pattern generator that generates a predetermined video pattern signal to be supplied to the image device under measurement, and the image data stored in the image memory is broken.
In an image position measuring device provided with a calculating means for calculating the image position of the video pattern and a timing control means, before the image position measurement, an all-white screen is displayed with a field of view capable of identifying the phosphor pitch of the image device under test. A CRT tube surface corresponding to the number of pixels of the image sensor from the distance of the center of gravity of the phosphor region of a predetermined color captured in the image memory and the phosphor pitch length of the CRT of the image device under measurement. An image position measuring device, characterized in that it is provided with a calibration means for outputting the distance of the distance in units of length. 3. The image position measuring device according to claim 2, wherein the pixel array of the image pickup device is inclined with respect to the phosphor pitch array of the image-under-measurement device. 4. A photographing means which is arranged so as to face the image device under measurement and which captures the display surface of the image device under measurement, and an image memory which captures the video signal output from the photographing device as image data. A pattern generator that generates a predetermined video pattern signal to be supplied to the image device under measurement, and the image data stored in the image memory is broken.
In an image position measuring device provided with a calculating means for calculating the image position of the video pattern and a timing control means, before the image position measurement, an all-white screen is displayed with a field of view capable of identifying the phosphor pitch of the image device under test. The distance between the centers of gravity of the phosphor regions when scanned in an image memory and the center of the centers of the phosphor regions captured in the image memory when obliquely scanned is obtained, and the distance between the centers of gravity and the measured object are measured. An image position measuring device comprising: a calibration means for outputting, in length units, a distance of a CRT tube surface corresponding to the number of pixels of an image sensor from a phosphor pitch length of the CRT tube surface of the image device. 5. The image position measuring device according to claim 4, wherein the oblique scanning is performed in a zigzag pattern.