JPS63224572A - Convergence device - Google Patents

Abstract

PURPOSE:To attain a static convergence correction automatically while a video is displayed on a screen by providing a photoelectric conversion element to the surrounding of the screen so as to detect the misalignment and using the detection signal to control a convergence circuit. CONSTITUTION:A signal subjected to photoelectric conversion by a photoelectric conversion element 30 is supplied to a detection circuit 37 comprising a maximum position detection circuit 31 and a symmetrical position detection circuit 32. The circuit 31 detects the maximum position of a pattern signal comprising plural scanning lines and the circuit 32 detects the position where the outputs of the elements adjacent to the position are symmetrical. The position of the position data from the circuit 37 is stored by a storage circuit 33 and the output from the circuit 33 is supplied to a comparator 34, where the output is compared with a position signal being a reference data, e.g., a green pattern signal. The output from the circuit 34 is fed to a convergence correction circuit 35, in which static misalignment is controlled so that the said output shares the same position as the green patter signal being the reference data.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a convergence device that automatically adjusts convergence that statically changes depending on temperature, etc. after dynamic convergence adjustment when adjusting the convergence of a color television receiver. It is.

Conventional technology In general, in a projection type color receiver that uses three projection tubes that emit three primary colors to project enlarged images onto a screen, the angle of incidence of the projection tubes on the screen is different for each projection tube, which causes color shift on the screen. arise. The superposition of these three primary colors, so-called convergence, is achieved by creating an analog convergence correction waveform in synchronization with the horizontal and vertical scanning cycles, and adjusting the size and shape of this waveform. There is a problem with accuracy. Therefore, as a method with high convergence accuracy, for example, the method of Japanese Patent Publication No. 5G-8114 and the method of Japanese Patent Application Laid-open No. 1983-61ffi52, which is a digital convergence device that can shorten adjustment time, simplify work, and perform automatic adjustment, have been proposed. has been done.

A first method of the conventional convergence device will be described below. Figure 6 shows a configuration diagram of a conventional digital convergence device, in which a convergence correction pattern such as a grid pattern (shown in Figure 7) is projected on the screen, and the convergence correction amount for each adjustment point is calculated. Data is digitally written into one frame memory, this data is read out, D/A converted, and convergence correction is performed.

First, as shown in FIG. 7, a grid pattern of, for example, nine rows in the horizontal direction and seven columns in the vertical direction is projected by the pattern projection circuit 1 on the screen. The horizontal direction signal 14 of this pattern signal is created by supplying a horizontal synchronizing signal 2 synchronized with the scanning of the screen to a horizontal address counter circuit 3 composed of a PLL circuit and a frequency dividing circuit.

Further, a vertical signal 16 is generated by a vertical address counter circuit 5 which is reset by a vertical synchronizing signal 4, and is supplied to a pattern projection circuit 1 and displayed. Next, using the cursor keys (not shown) on the control panel 8, select the grid point of the location to be corrected and the color to be corrected, for example, red. Grid points selected using the cursor keys (hereinafter referred to as adjustment points)
The address is stored in the write address generation circuit 7, and is supplied to the frame memory 11 via the frame memory control circuit 1o, and the correction data of the adjustment point specified by the cursor key is read out from the frame memory 11 and written into the data reversible counter 9. . Furthermore, by operating a write key (not shown) on the control panel 8, the data reversible counter 9 is increased or decreased, and the write correction is performed in the frame memory 11. Next, reading out the convergence correction data stored in the frame memory 11 will be explained. Horizontal and vertical addresses corresponding to the adjustment points of the screen are created and read out by a horizontal address counter circuit 3 that receives a horizontal synchronizing signal 2 synchronized with the scanning of the screen and a vertical address counter circuit 5 that receives a vertical synchronizing signal 4 as an input. The data is supplied to the address generation circuit 6, and added to the frame memory 11 via the frame memory control circuit 1° to read correction data for each adjustment point. Since the frame memory 11 stores only correction data for locations corresponding to each adjustment point, the vertical interpolation circuit 12 performs interpolation between adjustment points in the vertical direction. The vertical interpolation circuit 12 is composed of a subtraction circuit, a coefficient ROM, a multiplication circuit, an addition circuit, etc., and its operation is performed by, for example, the second row 16 and the third row 17.
A subtraction circuit calculates the difference from the correction data of the point adjustment point, a multiplication circuit multiplies the weight coefficient for each scanning line written in advance in the coefficient ROM, and the result is added to the correction data of the second row 17 in the addition circuit. and perform interpolation. The output of the vertical interpolation circuit 12 operating as described above is converted into an analog quantity by the D/A conversion circuit 13 to obtain a step-wave signal. The signal between the adjustment points in the horizontal direction is smoothed by a low-pass filter (not shown) according to the correction amount of the adjustment point in each row, and after amplification is supplied to the convergence yoke.

As mentioned above, in the conventional method, for each adjustment point,
Since the corrections can be performed independently, convergence correction can be performed with high accuracy.

Next, the second conventional method will be explained using FIG.

In FIG. 8, 18 is a projection tube, 19 is a projection lens, 2
o is a screen, 21 is a deflection yoke, and 22 is a convergence yoke. 23 amplifies the video signal arriving at the video signal input terminal to the necessary amplitude in the video circuit 24, and outputs the video signal to the projection tube 1.
Drive 8. The video circuit 24 operates in the same way as a normal receiver, but when adjusting the comparability, a convergence adjustment pattern such as a grid pattern created by the hygienic convergence circuit 26 is supplied and displayed. This convergence circuit 26 is the same as that explained in the conventional method 1, so its explanation will be omitted. The deflection circuit 27 and the deflection yoke 21 scan the electron beam of the projection tube 18 using the incoming synchronization signal 26. Although FIG. 8 shows only one projection tube 18, three projection tubes for red, green, and blue are normally used in a color receiver.The zero adjustment pattern detector 28 detects light from a camera, etc. The convergence adjustment pattern displayed on the screen is detected and supplied to the adjustment point detection circuit 29. The adjustment point detection circuit 29 detects a convergence shift at each adjustment point, changes the correction amount of the digital convergence circuit 25 based on a signal of the convergence shift, and automatically performs convergence adjustment. As a further automatic adjustment method, there is a method of correcting the convergence shift using a screen equipped with a photodetector, etc., but the explanation is omitted.Problems to be Solved by the InventionHowever, in the convergence device with the above configuration, Although the convergence can be adjusted with high accuracy, a static comparability deviation occurs after the power is turned on or due to the ambient temperature of the display device.

This static deviation is caused by neck charge of the projection tube, gun center drift, etc., DC drift of the convergence output circuit, and deformation of the convergence yoke due to heat.

This is a combination of changes in deflection and focus systems. Therefore, when adjusting convergence with high precision using the conventional method, it is necessary to perform the adjustment after sufficiently heat-running the display device. Furthermore, static deviations that occur after power is turned on or due to temperature rises have the problem of having to be adjusted each time the functional deviation, such as static centering, occurs.

In view of the above, it is an object of the present invention to provide a convergence device that accurately detects static color shift and automatically performs static convergence correction while an image is displayed.

Means for Solving the Problems The present invention provides an installation means for providing a plurality of photoelectric conversion elements in the periphery of a screen, a pattern generation means for generating a pattern signal for receiving light by the photoelectric conversion elements, and a method for generating a pattern signal from the photoelectric conversion elements. a detection means for detecting a position where the output of the photoelectric conversion element is maximum and the output of the photoelectric conversion element adjacent to the position is symmetrical; a storage means for storing position data from the detection means; and a position data from the storage means. The convergence device includes a comparison means for comparing data, and a convergence correction means for controlling the convergence correction means based on the output from the comparison means.

Function The present invention has the above-described configuration, and when a static convergence shift occurs due to temperature etc. after convergence adjustment, a plurality of photoelectric conversion elements are provided in the peripheral area of the screen to accurately correct the position shift. By detecting the detection signal and controlling the convergence circuit using the detection signal, static convergence correction can be automatically performed while an image is displayed on the screen. Embodiment FIG. 1 shows the first embodiment of the present invention. 1 shows a block diagram of a convergence device in an embodiment. In Figure 1,
36 is a pattern generation circuit that generates a pattern signal necessary for detecting a convergence shift, 3o is a plurality of photoelectric conversion elements provided at the periphery of the screen for detecting a convergence shift, and 31 is a circuit for outputting from the photoelectric conversion elements. A maximum position detection circuit detects the maximum position; 32 is a symmetrical position detection circuit that detects a position where the outputs of photoelectric conversion elements adjacent to the maximum position are symmetrical; 37 is a symmetrical position detection circuit with the maximum position detection circuit 31; 33 is a storage circuit that stores the position data from the detection circuit 37, 34 is a comparison circuit that compares the position data from the storage circuit 33, and 36 is a static detection circuit configured by the output signal from the comparison circuit. In the figure, parts that operate in the same way as the conventional ones are indicated by the same numbers and their explanations are omitted. 0 Regarding the convergence device of this embodiment configured as above. The operation will be explained below.Convergence adjustment for the entire screen is performed by the digital convergence circuit 26 or analog convergence circuit as in the conventional case.
After the adjustment is completed, the pattern generation circuit 36 displays pattern signals of each color passing through the plurality of photoelectric conversion elements 3o.
FIG. 2 shows a pattern signal 38 passing through the photoelectric conversion element 3o.
0 Immediately after the convergence adjustment is completed, there is no color shift and the same position is being scanned. 0 At this time, the photoelectric conversion element 3
The signal charged at 0 is supplied to a detection circuit 37 composed of a maximum position detection circuit 31 and a symmetrical position detection circuit 32.

The maximum position detection circuit 31 detects the maximum position of the pattern signal 38 made up of a plurality of scanning lines, and the symmetrical position detection circuit 32 detects the maximum position of the photoelectric conversion element 3 adjacent to that position.
Position detection is performed by detecting the position where the outputs of o are symmetrical. The position data from the detection circuit 37 is stored in the memory circuit 3.
3 memorizes the position. The output signal from the memory circuit 33 is supplied to a comparison circuit 34 and is compared with a position signal serving as reference data, such as a green pattern signal.Comparison circuit 3
The output from 4 is supplied to the convergence correction circuit 36, and the static deviation amount is controlled so that it is at the same position as the green pattern signal, which is the reference data.Next, the photoelectric conversion circuit installed at the periphery of the screen In order to explain the operation of the element 30 and the detection circuit 37 in detail, the operation diagram of FIG. 3 will be used. 38 is enlarged, and the pattern signal is composed of the signals on scanning @13 to 16. ◎The solid line in Figure 3 represents the photoelectrically converted output voltage from the photoelectric conversion elements 3o from Sl to S6, It is a diagram shown corresponding to the position of the charging conversion element, and the broken line shows the brightness characteristic on the screen. This photoelectrically converted voltage is supplied to the maximum position detection circuit 31 and the symmetrical position detection circuit 32.@The maximum position detection circuit 31 corresponds to the maximum position of the received pattern signal, that is, the maximum output voltage v3 shown in FIG. The symmetrical position detection circuit 32 detects the position (photoelectric conversion element 8a) of the photoelectric conversion element S2 adjacent to that position.
The position where the outputs v1 and v2 of S4 are symmetrical and equal is detected.By performing position detection using this maximum position detection and symmetrical position detection, the detection accuracy of divided sampling detection using multiple photoelectric conversion elements can be improved. ing.

Next, in order to explain the operation when a convergence shift occurs, the operation diagrams shown in FIGS. 4 and 6 will be used. This will be explained when 39 is shifted upward. An enlarged screen view is shown in FIG. Green pattern signal 3 is output @photoelectric conversion element 3o
8 and the red pattern signal 39, and the charged converted voltage is 0 as shown in FIG. Detection circuit 37
The detection signal from the memory circuit 33 stores position data.The output signal from the memory circuit 33 is supplied to the comparator circuit 34, which serves as reference data for the position data of the green pattern signal and the position data of the red pattern signal. The comparison output is supplied to the red vertical static convergence Wa positive circuit of the convergence correction circuit 36, and the red pattern signal 39 is displayed on the screen as shown in FIG.
By controlling the amount of static deviation so that it moves from B to B and becomes the same position as the green pattern signal 38, static convergence correction can be performed automatically. Similarly, the convergence adjustment of photoelectric conversion element 30. Alternatively, the correction can be performed by using a plurality of charge conversion elements in the horizontal direction at the bottom of the screen. Furthermore, the correction for blue color is also performed in the same manner as for red color, so a description thereof will be omitted.

As described above, according to this embodiment, pattern signals are received on a plurality of photoelectric conversion elements provided at the periphery of the screen, and the maximum position of the photoelectric conversion voltage and the output of the photoelectric conversion element adjacent to that position are By detecting symmetry and performing position detection, and controlling the convergence correction circuit using this detection signal, it is possible to reduce detection errors in sampling detection by multiple photoelectric conversion elements and perform highly accurate automatic static convergence correction. .

In this embodiment, static convergence correction has been described, but photoelectric conversion elements may also be provided in contradictory areas at the periphery of the screen to perform part of the dynamic convergence correction. Also, determine the dynamic deviation.

Needless to say, it is also possible to use a lamp or the like to indicate that the dynamic convergence adjustment is to be performed, and provide a dynamic convergence adjustment instruction.

Further, in this embodiment, the superimposition of the three primary colors, so-called convergence correction, has been described, but it goes without saying that control of screen amplitude, phase, etc. may also be performed.

Further, in this embodiment, a projection type color receiver has been described for ease of understanding, but it goes without saying that the present invention is also effective for a shadow mask type direct view receiver.

As described in detail, according to the present invention, when there is a systematic shift in convergence that has been precisely adjusted by digital and analog convergence circuits due to temperature, etc., an image can be projected on the screen. Static convergence correction can be automatically performed in the state of Because the position is detected,
Detection accuracy is high even with split sampling detection using multiple photoelectric conversion elements, and accurate convergence correction can be achieved.
Its practical effects are great.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a convergence device according to an embodiment of the present invention, and FIGS. 2, 3, and 4. 6 is a diagram for explaining the operation of the same embodiment, FIG. 6 is a block diagram of a conventional digital convergence circuit, FIG. 7 is a diagram for explaining the operation of the same circuit, and FIG. 8 is a diagram for explaining the operation of the conventional digital convergence circuit. It is a block diagram of a convergence device that performs automatic convergence adjustment. 036... Convergence correction circuit, 33... Memory circuit, 34...
... Comparison circuit, 3o... Multiple photoelectric conversion elements,
36... Pattern generation circuit, 37...
Detection circuit, 31... Maximum position detection circuit, 32.
...Symmetrical position detection circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure st sz ss s+ ss sb Koden Mugishuko Kiri! Fig. 4 Ditch Fig. 5, St Sz Ss S4 SS Fig. 7 Fig. 8

Claims (1)

[Claims] convergence correction means for correcting color shift on the screen; installation means for providing a plurality of photoelectric conversion elements at the periphery of the screen; and generating pattern signals at positions on the screen where the photoelectric conversion elements can receive light. a pattern generating means for detecting a position where the output from the photoelectric conversion element is maximum and at which the outputs of the photoelectric conversion elements adjacent to the position are symmetrical; A convergence device comprising a storage means for storing position data, a comparison means for comparing the position data from the storage means, and a control means for controlling the convergence correction means based on an output from the comparison means.