JPS58215887A - Digital convergence correcting device - Google Patents

Abstract

PURPOSE:To shorten an ajdustment time, by utilizing the symmetry of a waveform necessary for convergence corrections and correcting two symmetric colors simultaneously in one operation. CONSTITUTION:Once an adjustment point for convergence is selected with cursor keys 2 on a control panel 1, red convergence corrected value data on the point stored previously in a one-frame memory 5 is fetched in a data reversible counter 4. Further, an address of the memory 5 corresponding to the adjustment point is set in a cursor counter 10 and an address corresponding to green (DELTA array of electronic locks) at an adjustment point symmetrical to the adjustment point is set in a symmetrical adjustment point counter 21. If the convergence corrected value of red further increases, a write key 3 for red on the panel 1 is operated over a look at a screen to set new corrected value data in the counter 4. This data is written in the memory 5 and an address of green set in the counter 21 is accessed and written in the memory 5.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a digital convergence correction device.

A conventional convergence correction circuit is configured to obtain a convergence correction waveform in an analog manner from a horizontal 72-wavelength waveform and a vertical deflection waveform using passive elements such as inductance, capacitance, and resistance. However, such a conventional convergence correction circuit has a problem in terms of convergence correction accuracy. Therefore, in order to perform convergence correction with higher precision, methods for performing convergence correction digitally have been proposed in recent years.

This digital convergence correction device d projects a convergence correction pattern such as a dot pattern Id or a crosshatch pattern on the screen of a television receiver, and calculates each dot t□ point or each intersection of the dot 0 hatch. The data of the convergence correction amount for each m
The convergence correction amount for each convergence adjustment point in rows and columns (m and n are integers) is digitally written into one frame memory, and this information is read out and D/A converted to perform convergence correction. be.

This will be explained in detail below using the drawings. In Figure 1,
1 is a control panel having a cursor key 2 and a write key 3, 4 is a reversible data counter, 5 is a one-frame memory, 6 is an interpolation circuit, 7 is a D/A conversion circuit, 8 is a low-pass filter, and 9 is a control circuit, 10 is a cursor counter, 11 is a multiplexer, 12 is a coincidence detection circuit, 1
3 is an address counter, 14 is a cursor generation circuit, 1
5 is a crosshatch pattern generation circuit, 16 is an addition circuit,
17 is a synchronization signal input terminal.

Next, the operation of this digital convergence correction device will be explained. First, the control circuit 9 to which a synchronization signal is applied from the synchronization signal input terminal 17 controls the crosshatch pattern generation circuit 15 to display seven patterns horizontally and five vertically on the television screen, for example, as shown in FIG. Displays the crosshatch pattern of a book. In this case, the intersection of the crosshatches is used as the convergence adjustment point.

Then, when an adjustment point to be corrected is selected using the cursor keys 2 of the control panel 1, the address of this adjustment point is stored in the cursor counter 10. The address stored in the cursor counter 10 is applied to the coincidence detection circuit 12 together with the address of the address counter 13 which sequentially outputs the address of each adjustment point of the crosshatch pattern, and the output address of the address counter 13 and the memory of the cursor counter 1o are The cursor counter 10 is output from the cursor generation circuit 14 by the coincidence output when the address matches.
A cursor signal corresponding to the storage address is generated and added to the crosshatch pattern signal of a crosshatch pattern generation circuit 15 by an adder circuit 16, and the cursor is superimposed on the selected adjustment point on the television screen and displayed.

In this case, the cursor counter 10 stores the addresses of adjustment points sequentially moved up, down, left and right from the original adjustment point by operating the up, down, left and right cursor keys 2.

After selecting the adjustment point in this way, set the desired data on the data reversible counter 4 while looking at the screen with the writing key 3 of the color you want to correct, for example red, and set the output of the data reversible counter 4 horizontally or vertically. It is written to the address specified by the cursor counter 10 of the one frame memory 5 during the retrace period.

In this case, the data reversible counter 4 has read out the contents of the one frame memory 5 at the address specified by the cursor counter 10, and if you want to further increase the convergence correction amount, increase the contents of the data reversible counter 4. If you want to decrease the data, use the data reversible counter 4.
Reduce the contents of the desired data into one frame memory 5
Write correction is performed by writing to . The same procedure is repeated for all adjustment points on the screen.

Next, reading out the convergence correction amount written in the one-frame memory 5 will be explained. This one
The convergence correction amount data for each adjustment point stored in the frame memory 5 is read out by the address signal output from the address counter 13 in synchronization with the image forming signal corresponding to each intersection of the crosshatch in FIG. However, 1
Since the frame memory 5 only has correction amount data for locations corresponding to adjustment points, it is necessary to find the correction amount for each scanning line between adjustment points in the vertical direction. Therefore, the interpolation circuit 6
From the convergence correction amount of the first adjustment point and the convergence correction amount of the second adjustment point immediately below the first adjustment point, calculate the correction amount for each scanning line included between the first and second adjustment points. The output signal of the interpolation circuit 6 is converted into an analog quantity by the D/A conversion circuit 7. Since the output signal waveform of the D//A conversion circuit 7 is a staircase waveform, the low-pass filter 8
After smoothing and amplifying, the signal is supplied to a convergence yoke (not shown).

The above explanation has been given using red as an example, but the same applies to correction of other colors.

This digital convergence correction device can perform convergence correction with high precision because it can independently perform convergence correction for each adjustment point on the screen.

However, conversely, the convergence correction amount must be written into the one-frame memory 5 for each color at each adjustment point, which has the disadvantage that adjustment takes a very long time, especially when the amount of convergence deviation is large.

If the electron gun is arranged in a delta arrangement, the red and green electron guns are generally located in symmetrical positions with the blue electron gun in the center, and if the electron gun is in an inline arrangement, the red and blue electron guns are arranged in symmetrical positions with the blue electron gun in the center. are arranged symmetrically.

At this time, after adjusting the static convergence, the convergence shift u at Noscreen 2, as shown in Figure 3, in the case of delta arrangement, red and green, and in the case of inline arrangement, red and blue, As is well known, the two sides are symmetrical.

Therefore, the present invention focuses on the fact that the waveform required for convergence correction is symmetrical, and when the convergence deviation is large, for example, when adjusting a red adjustment point, the adjustment point is adjusted at a position symmetrical to this adjustment point. There is a coarse adjustment mode that writes the same amount of correction as red for green or blue points, and a fine adjustment mode that allows you to independently correct each color and each adjustment point when the deviation becomes small. This is an attempt to shorten the time period.

In order to facilitate understanding, the following explanation will be given assuming that the electron guns are arranged in a delta arrangement. In FIG. 4, the red correction amount at adjustment point A1 is equal to the green correction amount at left-right symmetrical adjustment points of A1, and the red correction amount at A2 is equal to the green correction amount at A6. Similarly, regarding other adjustment points, the red and green correction amounts of mutually symmetrical adjustment points are equal.

One embodiment of the present invention will be described using FIG.

In FIG. 5, parts that perform the same operations as in FIG. 1 are designated by the same numbers, and their explanations will be omitted.

It is assumed that the coarse adjustment mode is selected using the mode key 20 of the control panel 1, and that the convergence of red color is adjusted.

Cursor key 2 on control panel 1 When you select the adjustment point at which you want to perform convergence, for example, point A1 in Figure 4, the selected adjustment point will be displayed on the television screen and one frame memory will be displayed as described above. The red convergence correction amount data X at that point, which has already been written in the data reversible counter 4, is taken into the reversible data counter 4.

Further, the cursor counter 1o is set with the address A1' of the one frame memory 5 corresponding to the red adjustment point A1, and the symmetrical adjustment point counter 21 is set with the address A7' corresponding to the adjustment point Aρgreen that is symmetrical to the adjustment point A1. is set.

Now, suppose you want to further increase the red convergence correction amount, and if you operate the red write key 3 on the control panel 1 while looking at the screen, the correction amount data X stored in the data reversible counter 4 will increase, and a new Correction amount data X' is set. This new correction amount data X'
The red address A, / set in the cursor counter 1o is addressed via the multiplexer 11, and is written into the memory for one frame as red correction amount data.
At the same time, the green address A7/ set in the symmetry adjustment point counter 21 is addressed via the multiplexer 11 and also written as green correction amount data.

That is, by the above operation, the red correction amount data X of the adjustment point A1 is also written into the correction amount data of the green adjustment point Aρ, which is symmetrical to the adjustment point A1. If you perform the above operations for red ~, A3...E7, and all screens, red convergence correction will be performed, and at the same time, green convergence correction will be applied to almost all screens.
This means that convergence correction has been performed.

If the above operations still result in insufficient convergence correction (7) and 8 degrees correction, switch to fine adjustment mode using the mode key 20 on the control panel 1. The operation in the fine adjustment mode is similar to that described in the conventional example, and the correction amount data for each color and each adjustment point is independently written into the one frame memory 5.

As is clear from the above description, if the present invention is used, the symmetry of the waveform necessary for convergence correction can be utilized,
It has a coarse adjustment mode that allows you to correct red and green simultaneously with a single operation, and a fine adjustment mode that allows you to adjust each color and each adjustment point independently, so you can maintain convergence correction accuracy. This has the advantage that the adjustment time is greatly reduced.

In the above explanation, the electron guns are arranged in a delta arrangement. It goes without saying that the concept of the present invention is also effective in the projection type receiver used.

[Brief explanation of the drawing]

Figure 1 is a block diagram of a conventional digital convergence correction device, Figure 2 is a diagram showing the projected state of a crosshatch pattern, Figure 3 is a diagram showing convergence deviation after static convergence adjustment, and Figure 4 is a diagram showing the adjustment. FIG. 5 is a block diagram of a digital convergence correction device according to an embodiment of the present invention. 10...Cursor counter, 12...-...
Coincidence detection circuit, 13...Address counter, 1
4...L...Cursor generation circuit, 15...S0 crosshatch pattern generation circuit, 16...Addition circuit,
21...eo・Symmetry adjustment point counter, 11 Shoken・IIe
・Multiplexer, 5...1 frame memory,
9...@@@- control circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 3
Figure 4

Claims (1)

[Claims] The screen of a color display tube is arranged in m rows and n columns (m and n are integers)
has a one-frame memory that digitally stores the convergence correction amount for each adjustment point,
The content of this 1-frame memory is read out in synchronization with the scanning of the color TV receiver [image] to perform convergence correction, and the address corresponding to the 1-frame memory of the selected adjustment point of the selected color is stored. and one of the symmetrical adjustment points of the selected adjustment point of the color whose convergence shift of the selected color is symmetrical.
and a symmetrical adjustment point counter that stores an address corresponding to the frame memory, and transmits the same correction amount data as the convergence correction amount data of the selected adjustment point of the selected color to the symmetrical adjustment point counter of the color in which the convergence shift is symmetrical. A digital convergence correction device characterized by writing in one frame memory as correction amount data of left-right symmetrical adjustment points.