JPS63221787A - Convergence device - Google Patents

Abstract

PURPOSE:To detect the position deviation of convergence with high accuracy and sensitivity by controlling the detection period of a detector to detect the position synchronously with the period of a pattern signal detected by the detector. CONSTITUTION:When a pattern signal is displayed on a screen 20, the position of the adjusting point in the pattern signal is detected by the detector 30 provided on the screen 20 and stored in a storage circuit 32. In this case, the period of the detection signal, that is, the period of the pattern signal is used for the detection synchronously by a detection period control circuit 31 to control the detection period of the detector 30. When the position data of the adjusting point is obtain with respect to a green pattern signal and red pattern signal, both the position data are compared by a comparator circuit 33 and the convergence correction is controlled so that the red pattern signal is at the same position of the reference green pattern signal on the screen by the convergence correction circuit 34.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a convergence device that accurately detects a convergence deviation and adjusts it to a convergence correction means when adjusting the convergence of a color television receiver.

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, there is a method disclosed in Japanese Patent Publication No. 59-811, and a digital convergence device that can shorten adjustment time and perform automatic adjustment, and Japanese Patent Application Laid-Open No. 55-61552. Proposed.

A first method of the conventional convergence device will be described below. Figure 7 shows a configuration diagram of a conventional digital convergence device, in which a convergence correction pattern such as a grid pattern (shown in Figure 8) is projected on the screen, and the convergence correction amount for each adjustment point is calculated. Data is digitally stored in one frame memory, this data is read out, D/A converted, and convergence correction is performed.

First, as shown in FIG. 8, a grid pattern of, for example, nine rows in the horizontal direction and seven columns in the vertical direction is displayed on the screen by the pattern projection circuit 1. 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, use the cursor keys (not shown) on the control panel 80 to select the grid point at 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 from the frame memory 11 and written into the reversible data 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 written 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 6 that receives a vertical synchronizing signal 4 as an input. The correction data for each adjustment point is read out from the frame memory 11 via the frame memory control circuit 1. The frame memory 11 only stores correction data for locations corresponding to each adjustment point, so between adjustment points in the vertical direction,
A vertical interpolation circuit 12 performs interpolation. 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, for example, subtraction from correction data d- of two adjustment points on the second line 16 and third line 17. Find the difference in the circuit,
A multiplication circuit multiplies the weighting coefficient for each scanning line written in advance in the coefficient ROM, and the result is applied to the second line 17.
The correction data of is added by an adding circuit and interpolation is performed. 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 being amplified, 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.

The second conventional method will be briefly explained using Figure @9.

In FIG. 9, 18 is a projection tube, 19 is a projection lens, 2
0 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 a required width in the video circuit 24, and then outputs the video signal to the projection tube 1.
Drive 8. The video circuit 24 operates in the same way as a normal television receiver, and when adjusting convergence, a convergence adjustment pattern such as a grid pattern created by the digital 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. 9 shows only one projection tube 18, three projection tubes, red, green, and blue, are normally used in a color receiver. The adjustment pattern detector 28 is a device that performs light detection using a camera or the like, detects a convergence adjustment pattern projected on a screen, and supplies the detected convergence adjustment pattern to an 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 26 based on a signal of the convergence shift, and automatically performs convergence adjustment.

Furthermore, as a method of automatic adjustment, there is a method of correcting the convergence shift using a screen equipped with a photodetector, but the explanation thereof will be omitted.

Problems to be Solved by the Invention However, in the convergence device configured as described above, since the projection period of the convergence adjustment pattern and the detection period of the photodetector are different, detection accuracy at a minute detection level cannot be achieved. There was a problem. Furthermore, in order to accurately detect various types of displays with different projection periods, there is a problem in that the detection period of the photodetector must be changed each time.

In view of the above, an object of the present invention is to provide a convergence device that accurately detects convergence deviation and automatically performs convergence correction.

Means for Solving the Problems The present invention provides detection means for detecting screen convergence deviation, pattern generation means for generating a pattern signal to be detected by the detection means, and periodicity of the pattern signal detected by the detection means. detection period control means for controlling the detection period of the detection means so as to detect and perform detection in synchronization with the detection period; storage means for storing position data from the position detection means; and position data from the storage means. and a convergence device that controls convergence correction means based on the output from the comparison means.

Effect of the Invention With the above-described configuration, the present invention controls the position detection in synchronization with the period of the pattern signal detected by the detector, detects positional deviation with high precision and sensitivity, and uses the detection signal to drive the convergence circuit. By controlling this, convergence correction can be automatically performed.

Embodiment FIG. 1 shows a block diagram of a controller according to a first embodiment of the present invention.

In FIG. 1, numeral 30 is a pattern generator that generates a pattern signal for detecting a convergence shift, 30 is a detector for detecting a convergence shift, and 31 is a detector that detects the period of the pattern signal from the detector 3o. A detection period control circuit for controlling the detection period of the detector 3o so as to perform detection in synchronization with the detection period; 32 a storage circuit for storing position data from the detection period control circuit 31; and 33 a position data from the storage circuit 32. Comparison circuit for comparing data, 34
is an intensity correction circuit that performs convergence correction using the output signal from the comparison circuit 33. In the figure, components that operate in the same way as in the conventional system are designated by the same numbers and their explanations will be omitted.

In order to explain the operation of the convergence device of this embodiment configured as described above, the screen diagram and waveform diagram of FIG. 2 will be used below. FIG. 2a shows a screen 2o, on which detectors 3o are provided at positions corresponding to adjustment points in nine rows in the horizontal direction and five columns in the vertical direction. First, the pattern signal 36 indicated by the solid line in FIG. 2 will be explained as an example. The position of the adjustment point A shown in FIG. 2a is detected by the detector 3o. The detection signal detected by the detector 3o is supplied to a detection cycle control circuit 31, which controls the detection cycle of the detector 3o so that detection is performed in synchronization with the cycle of the detection signal, that is, the cycle of the pattern signal. The signal detected in synchronization with the pattern signal 35 from the detection cycle control circuit 31 stores position data in the storage circuit 32.

The color switching of the pattern signal is such that during the first field scanning, the green pattern signal 35 shown by the solid line in FIG. 2a is changed to the green pattern signal 35 shown by the broken line in FIG.
6 is output from the pattern generation circuit 32. Detection of the red pattern signal 36 is also performed in synchronization with the period of the pattern signal, as described above. First, the horizontal convergence adjustment method will be explained in detail.

The green pattern signal 35 shown by the solid line in FIG.
The red pattern signal 36 indicated by the broken line in FIG. 2 is also detected by the detector 3o, resulting in the signal C in FIG. 2. This position data is stored in the storage circuit 32, and the position data of the green pattern signal 35 shown in FIG. 2C and the position data of the red pattern signal 36 shown in FIG. is supplied to The comparison circuit 33 uses a green pattern signal 36 as reference data.
The position data of the red pattern signal 36 is compared with the position data of the red pattern signal 36. This comparison output is supplied to the convergence correction circuit 34, and the convergence correction amount is controlled so that the red pattern signal 36 is at the same position on the screen as the green pattern signal 36 which is the reference data. The position of the red pattern signal 36 shown in C is moved from point B to point 0. This means that horizontal green and red convergence adjustment has been performed. Further, since the vertical direction and the blue color are performed in the same manner as the red color, a description thereof will be omitted.

Next, in order to explain the detection cycle control circuit 31 in detail, the block diagram of FIG. 3 and the operation diagram of FIG. 4 will be used. Third
In the figure, the detector 3o is composed of, for example, an image sensor 37, and the detection cycle control circuit 31 is composed of cycle detection circuits 3 and 8 and a PLL circuit 39. The pattern signal received by the image sensor 37 is photoelectrically converted, and the image sensor 37 outputs a photoelectrically converted output signal shown in FIG. 4a. This photoelectric conversion output signal is supplied to a period detection circuit 38, which detects the peak period of the photoelectric conversion output signal shown in FIG. 4a, and detects the period of the pattern signal as shown in FIG. 4S.

This pattern signal detection cycle signal is supplied to the PLL circuit 39, which generates a clock signal synchronized with the cycle of the pattern signal to drive the image sensor 37, thereby detecting the pattern signal received by the image sensor 37. Position detection can be performed in synchronization with the cycle. Also the fourth
When photoelectric conversion outputs with different projection periods are obtained as shown in FIG. d, the period detection circuit 38 similarly detects the signal shown in FIG. Generates a clock signal synchronized with the signal period,
By driving the image sensor 37, synchronous position detection can be performed.

As described above, according to this embodiment, the convergence correction circuit is controlled by the detection signal that controls the detection cycle of the detector so that position detection is performed in synchronization with the cycle of the pattern signal detected by the detector. Therefore, highly accurate automatic convergence correction can be performed.

FIG. 5 is a block diagram of a convergence device showing a second embodiment of the present invention. The configuration that differs from the one shown in FIG. 1 is a detection period signal generation circuit 40 that generates a detection period signal for controlling the detection period, and an adder 41 that adds the pattern signal from the pattern generation circuit 32 and the detection period signal. The point is that the signal is provided and supplied to the video circuit 24.

FIG. 6 shows the screen 2o. On the screen, detectors are provided at positions corresponding to each adjustment point as in FIG. This is reflected in the detection period signal 42. Detector 3
The signal received at o is used for position detection using a pattern signal. The detection cycle control circuit 3 also detects a detection cycle using the weft cycle signal, and controls the detection cycle control circuit 3 to detect the detector 3o at this signal cycle.
It is controlled by 1. This detection signal is supplied to the memory circuit 32, and a similar operation is performed to perform convergence correction.

As described above, by separating the pattern signal for position detection and the detection period signal for controlling the detection period, accurate detection can be achieved even on various displays with different detection periods, and automatic convergence correction can be performed. I can do it.

In this embodiment, a case has been described in which a sensor is provided as the light detection means to perform position detection, but it goes without saying that the present invention is also effective in a case where position detection is performed using a camera.

Although dynamic convergence correction has been described in this embodiment, it goes without saying that static convergence correction may be performed by providing a detector at the periphery of the screen.

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.

In addition, in this example, the detection period signal is used only to control the detection period, but it may also be used as a cursor display for specifying adjustment points when performing a digital convergence method. Needless to say.

As described in detail, according to the present invention, by performing position detection in synchronization with the cycle of the pattern signal received by the detector, it is possible to always detect in synchronization even on various displays with different projection cycles. Therefore, it is possible to perform accurate detection and automatically perform convergence correction.

Further, data processing between the detector and the signal processing system does not require a synchronizing signal for the detection cycle, so even in a system where the detector and signal processing system are separated, the circuit configuration is simple and the practical effect is large.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a convergence device according to an embodiment of the present invention, FIG. 2 is a diagram for explaining the operation of the same embodiment, and FIGS. 3 and 4 are operations of the detection period control circuit of the same device. ' Block diagram and operation waveform diagram for explanation, Part 5
The figure is a block diagram of a convergence device according to another embodiment of the present invention, FIG. 8 is a diagram for explaining the operation of the same embodiment, FIG. 7 is a block diagram of a conventional digital convergence device, and FIG. Diagrams to explain the operation of the circuit,
FIG. 9 is a block diagram of a conventional convergence device that automatically performs convergence adjustment. 34... Convergence M positive circuit, 32...
. . . t is a circuit, 33 . . . Comparison circuit, 30.
...detector, sweet...detection period control circuit, 3
2...Pattern generation circuit, 4o...Detection cycle signal generation circuit, 41...Adder. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure, % 35 B feeling C disease Figure 3 Figure 4 Figure 6 Figure 8 Figure 9

Claims (2)

[Claims] (1) a convergence correction means for correcting color shift on the screen; a detection means for detecting the convergence shift on the screen; a pattern generation means for generating a pattern signal to be detected by the detection means; Detection cycle control means for detecting the cycle of the pattern signal detected by the detection means and controlling the detection cycle of the detection means so that detection is performed in synchronization with the detection cycle; and storing position data from the output of the detection means. A convergence device comprising: storage means for comparing position data from the storage means; comparison means for comparing position data from the storage means; and control means for controlling the convergence correction means based on an output from the comparison means. (2) The convergence device according to claim 1, wherein the pattern generating means superimposes the detection periodic signal on the pattern signal.