JPS63209387A - Convergence device - Google Patents

Abstract

PURPOSE:To automatically execute a static convergence correction in a state displaying an image is displayed by superimposing a pattern signal to a video signal compressed with time base and detecting positional deviation based on that. CONSTITUTION:When static convergence deviation is generated caused by temperature or the like after finishing convergence adjustment, a pattern signals is superimposed 36 to the video signal compressed with the time base 37 and displayed on a display screen. This pattern signal is light-received on a position detector 30 provided on the peripheral part of the screen and the positional deviation is detected. By this detection signal, a convergence correction circuit 34 is controlled. Thus the static convergence correction can be automatically executed in the state displaying the video on the screen.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention is used to adjust the convergence of a color television receiver, and after adjusting the dynamic convergence, automatically adjusts the Kg of the convergence that statically moves depending on temperature, etc. The present invention relates to a convergence device.

2. Description of the Related Art In general, in a color receiver that uses three projection tubes emitting three primary colors to project enlarged images onto a screen, color shift occurs on the screen because the angle of incidence of the projection tubes on the screen is different for each projection tube. The superposition of these three primary colors,
So-called convergence is achieved by using an analog convergence correction waveform in synchronization with the horizontal and vertical scanning cycles.
Although this method uses a method of adjusting the size and shape of this waveform, there is a problem in terms of convergence accuracy.

Therefore, as a method with high convergence accuracy, for example,
Japanese Patent Publication No. 59-8114 and Japanese Patent Application Laid-Open No. 65-61552 have proposed a digital convergence device capable of automatic adjustment, which shortens adjustment time and facilitates work.

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

First, as shown in FIG. 6, a grid pattern of, for example, nine horizontal rows and seven vertical columns is projected 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 15 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 8 to 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 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 5 that receives a vertical synchronizing signal 4 as an input. The data is supplied to the address generation circuit 6 and read out from the frame memory 11 via the frame memory control circuit 10 as well as the correction data of each adjustment point. Since the frame memory 11 only stores correction data for locations corresponding to each adjustment point,
A vertical interpolation circuit 12 performs interpolation between adjustment points in the vertical direction. Vertical interpolation circuit 12 is a subtraction circuit, coefficient ROM
, a multiplication circuit, an addition circuit, etc., and its operation is, for example, by calculating the difference from the correction data of the two adjustment points on the second line 16 and the third line 17, using a subtraction circuit, and calculating the difference from the coefficients written in advance in the coefficient ROM. A multiplication circuit multiplies the weighting coefficients for each scanning line, and the result is added to the correction data 17 on the second row in an addition circuit to 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 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.

Next, the second conventional method will be explained in Section 6.6 using FIG. In FIG. 7, 18 is a projection tube, 19 is a projection lens, 20 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 necessary amplitude in the video circuit 24 and drives the projection tube 18.

The video circuit 24 operates in the same way as a normal receiver, and when adjusting convergence, the U digital convergence circuit 2
The convergence adjustment pattern such as the grid pattern created in step 5 is supplied and displayed. This convergence circuit 25 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 receive the incoming synchronization signal 2.
6, the electron beam of the projection tube 18 is scanned.

Although FIG. 7 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 performs light detection using a camera or the like, detects the convergence adjustment pattern projected on the screen, and supplies it 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.

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, although the convergence device configured as described above can perform convergence adjustment with high accuracy, static convergence drift may occur after the power is turned on or due to the ambient temperature of the display device. Color shift occurs. This static convergence drift is caused by neck charge of the projection tube, gun center drift, etc., or DC drift of the convergence output circuit.

This is a combination of thermal deformation of the convergence yoke, changes in the deflection and focus system, etc. Therefore, when adjusting convergence with high accuracy using conventional analog and digital methods, it is necessary to perform the adjustment after sufficient heat run of the display device. Furthermore, static deviations that occur after power-on or due to temperature rise are
This had the problem of having functions such as static centering, which had to be adjusted each time.

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 a position detecting means for detecting a positional shift using a photoelectric conversion element provided at the periphery of a screen, and a pattern generated on the screen that can receive a pattern signal by the position detecting means. generating means; time-base compression means for time-base compressing the video signal input to the receiver; addition means for calculating the pattern signal from the pattern generation means and the video signal from the time-base compression means; and addition means. A display means for displaying the pattern signal added at the light receiving position of the position detection means, a recording means for storing the position data from the position detection means, and a comparison means for comparing the position data from the storage means 9, -7. This is a convergence device that controls the convergence correction means from the output port of the convergence device.

According to the above-described configuration, the present invention superimposes a pattern signal on the time-axis compressed video signal and projects it on the screen when a static convergence shift occurs due to temperature etc. after completing the convergence adjustment. is received by a position detector installed around the screen to detect positional deviation.
By controlling the convergence correction circuit using the detection signal, static convergence correction can be automatically performed while an image is displayed on the screen.

Embodiment FIG. 1 shows a block diagram of a convergence device in a first embodiment of the present invention. In Figure 1, 3
7 is a time axis compression circuit for compressing the video signal in the time axis;
35 is a pattern generation circuit that generates a pattern signal for detecting a convergence shift, and 36 is a time-axis compressed video signal and a filter.

An adder for adding turn signals, 3o a position detector for detecting convergence deviation, 32 a memory circuit for storing position data from the position detector 30, and 33 a comparison of position data from the memory circuit 32. comparison circuit, 34
is a convergence correction circuit that performs static convergence correction using the output signal from the comparison circuit 33. In the figure, components that operate in the same manner as in the prior art are designated by the same numbers and explanations will be omitted.

In order to explain the operation of the convergence device of this embodiment configured as follows, the operation diagrams shown in FIGS. 2 and 3 will be used.

A video signal of a horizontal effective display period T1 as shown in FIG. 3(a) is applied to the input terminal 23 in FIG. 1, and is supplied to the time axis compression circuit 37. The time axis compression circuit 37 compresses the video signal in the horizontal effective display period T1 shown in FIG. The time axis is compressed. The time-base compressed video signal from the time-base compression circuit 37 is sent to an adder 36.
supplied to A pattern signal from a pattern generation circuit 36 that generates a pattern signal for detecting an invergence shift is also supplied to the adder 36, and the time axis compression circuit 3 shown in FIG. 3(b)
The signal from 7 and the pattern signal shown in FIG. 3(0) are added, and the adder 36 outputs an addition output as shown in FIG. 3(d). The screen when this signal is projected on the screen is shown in FIG.
8 is shown.

The portion indicated by the broken line is scanned by the deflection circuit 27 in FIG. 1 and indicates an effective scanning period. On the screen displayed as described above, immediately after the convergence adjustment is completed, the same position is scanned without any shift in each color. The position is detected by the position detection circuit 3o, and this position data is stored in the storage circuit 32. The output signal from the memory circuit 32 is stored in a comparator circuit 33, where it is compared with a position signal serving as reference data, such as a green pattern signal, and this comparison output is supplied to a convergence correction circuit 34 to generate a green pattern serving as reference data. The amount of static deviation is controlled so that the position is the same as the signal.

Next, the operation when a convergence shift occurs will be explained. For example, the pattern generation circuit 36 after convergence adjustment
The explanation will be given assuming that the projected screen is, for example, when the red pattern signal 39 is shifted upward as shown in FIGS. 2 to 4. Note that the color switching of the pattern signal at this time is such that the green pattern signal is generated during the first field scan, and the red pattern signal is generated during the second field scan by the device detector 30 composed of the pattern generation circuit 35. The position of the pattern signal 39 is detected, and the position information corresponding to the green pattern signal 38 and red pattern signal 39 is stored in the memory circuit 32.
The location is memorized. The output signal from the memory circuit 32 is supplied to a comparison circuit 33, which compares the position information of the green pattern signal and the position information of the red pattern signal, which serve as reference information, and sends this comparison output to the red vertical direction static signal of the convergence correction circuit 34. Static convergence correction can be performed by supplying the signal to the convergence correction circuit and controlling the static deviation amount so that it is at the same position as the green pattern 38, which is the reference information.

Further, convergence adjustment for static deviations in the left and right directions can also be performed in the same way. Furthermore, since the process for blue color is similar to that for red color, the explanation will be omitted.

As described above, according to this embodiment, the video signal input to the receiver is compressed in the time axis, a pattern signal is superimposed on this signal and projected on the screen, and this pattern signal is applied to the periphery of the screen. The installed position detector receives the light and detects the positional deviation.
By controlling the convergence correction circuit with the detection signal, the video signal can be displayed on the display screen without overscanning, and static convergence adjustment can be performed automatically.

Although static convergence correction has been described here, position detectors may also be provided in contradictory areas around the screen to perform part of the dynamic convergence correction. It goes without saying that a dynamic convergence adjustment instruction may also be given by determining whether the deviation is dynamic and displaying a display using a lamp or the like to indicate that the dynamic convergence adjustment is to be performed.

In the first embodiment, we have described time axis compression when one type of video signal is input, but time axis compression used for scan conversion when multiple video signals with different aspect ratios are input is also discussed. It goes without saying that it may also be used as a means.

Although the description has been given here of a projection type color receiver for ease of understanding, it goes without saying that the present invention is also effective for a shadow mass type direct view type receiver.

As described in detail, according to the present invention, if the convergence, which has been precisely adjusted by the digital and analog dynamic convergence correction circuits, undergoes a static deviation due to temperature, etc., the image displayed on the screen can be adjusted. Static convergence correction can be performed automatically.

In addition, the video signal is compressed on the time axis and the pattern signal is superimposed on this signal and displayed on the screen, so the video signal can be displayed without overscanning the display screen.
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, FIGS. 2, 3, and 4 are diagrams for explaining the operation of the same embodiment, and FIG. 6 is a diagram of a conventional digital convergence circuit. 6 is a diagram for explaining the operation of the circuit, and FIG. 7 is a block diagram of a conventional convergence device that automatically adjusts convergence. 34... Convergence correction circuit, 32...
...Memory circuit, 33...Comparison circuit, 30...
...Position detector, 37...Time axis compression circuit, 35...Pattern generation circuit, 36...
- Adder, 27...Deflection circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure 3 Figure 4

Claims (1)

[Claims] A convergence correction means for correcting color shift on the screen of a color television receiver; a position detection means for detecting position shift using a photoelectric conversion element provided at the periphery of the screen; a pattern generating means for generating a pattern at a position on the screen where light can be received by the detecting means; a time axis compressing means for compressing the time axis of a video signal input to the receiver; and a pattern signal from the pattern generating means and the time axis. Adding means for adding the video signal from the compression means; display means for displaying the pattern signal added by the adding means at the light receiving position of the position detecting means; and storing position data from the output of the position detecting means. A convergence device comprising: a storage means for comparing position data from the storage means, a comparison means for comparing position data from the storage means, and a control means for controlling the convergence correction means based on an output from the comparison means.