JPH0468688A - Digital convergence correction device - Google Patents

Abstract

PURPOSE:To realize high accuracy convergence compensation for short adjustment time by storing the correction pattern of the entire screen, selecting and inputting a pattern to be corrected. CONSTITUTION:When a synchronizing signal is inputted from a synchronizing signal input terminal 13, a cross hatch pattern generation circuit 15 reflects the cross hatch pattern on a television screen. The intersection point of the cross hatch is in a convergence adjustment point. By the state of misconvergence on the screen, the adjustment pattern is selected by a control panel 1, and the correction amount in the adjustment pattern is set. A data operation microcomputer 24 by patterns writes the data for one screen in an one frame memory 5 based on this data, a correction data is called from the one frame memory 5 while matched with the scanning on the screen by an address counter 16 based on the synchronizing signal to be converted to the analog amount by a D/A conversion circuit 7. Thus, the misconvergence of the entire screen is corrected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a digital convergence correction device used in a color CRT display device.

[Prior Art] FIG. 5 is a block diagram showing the configuration of a conventional digital convergence correction device described in, for example, Japanese Patent Laid-Open No. 58-215887.

The digital convergence correction device has a control panel (1), and the control panel (1) is provided with a cursor key (2) for selecting an adjustment point and a write key (3) for writing data.

A data reversible counter (4) is connected to the control panel (1), and a data reversible counter (4) is connected to the control panel (1).
4) is connected to a 1-frame memory (5) that stores the convergence correction amount;
) is fed back to the data reversible counter (4).

Furthermore, an interpolation circuit (6) that calculates the amount of correction for each scanning line included between adjustment points is connected to the one-frame memory (5), and the interpolation circuit (6) includes a D/A conversion circuit. (7) is connected, and a low-pass filter (8) is connected to the D/A conversion circuit (7).

A cursor counter (9) is also connected to the control panel (1), and a multiplexer (10) and a match detection circuit (11) are connected to the cursor counter (9).
is connected.

The match detection circuit (11) includes a cursor generation circuit (
12) is connected, and the multiplexer (10) is connected to 1
Connected to frame memory (5).

On the other hand, the digital convergence correction device has a synchronization signal input terminal (13).
3) is connected to a control circuit (14).

A crosshatch pattern generation circuit (15) and an address counter C16) are connected to the control circuit (14), and the crosshatch pattern generation circuit (15)
An adder circuit (17) is connected to the adder circuit (17).
7) is connected to a cursor generation circuit (12).

Furthermore, the address counter (16) is connected to the coincidence detection circuit (11).
) and multiplexer (10).

Next, the operation will be explained.

When a synchronization signal is input from the synchronization signal input terminal (13), the control circuit (14) controls the crosshatch pattern generation circuit (15) to project a crosshatch pattern of 5 rows and 7 columns on the television screen. (See Figure 6).

Note that the intersection of the crosshatches is the convergence adjustment point.

Then, press the cursor keys (2) on the control panel (1).
) to select an adjustment point to be corrected, the address of this adjustment point is stored in the cursor counter (9).

Then, the address stored in the cursor counter (9) is applied to the coincidence detection circuit (11) together with the address of the address counter (16) which sequentially outputs the address of each adjustment point of the crosshatch pattern.
When the output address of the cursor counter (9) matches the output address of the cursor counter (9), a coincidence output causes the cursor generation circuit (12) to generate a cursor signal corresponding to the memory address of the cursor counter (9). 1
7) is added to the crosshatch pattern signal from the crosshatch pattern generation circuit (15), and the cursor is superimposed on the selected adjustment point on the television screen and displayed.

In this case, the cursor counter (9) 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.

After selecting the adjustment point in this way, use the write key (3) for the color you want to correct, for example red, and set the desired data on the data reversible counter (4) while looking at the screen.
The output of the data reversible counter (4) is sent to the cursor counter (9) of the one frame memory (5) during the horizontal or vertical blanking period.
) to the specified address.

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 (9), and if you want to further increase the convergence correction amount, the data reversible counter (4) Counter (4)
When it is desired to increase or decrease the contents of the data reversible counter (4), write correction is performed by decrementing the contents of the data reversible counter (4) and writing desired data into the one frame memory (5).

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.

The convergence correction amount data for each adjustment point written in this one frame memory (5) is stored in the address counter (1
6) is read out in synchronization with the video signal corresponding to the crosshatch intersection in FIG. 6 by the address signal output from.

However, since the one-frame memory (5) only has correction data for locations corresponding to adjustment points, it is necessary to find the amount of correction for each scanning line between the adjustment points in the vertical direction.

Therefore, the interpolation circuit (6) calculates the convergence correction amount included between the first and second adjustment points from the convergence correction amount at the first adjustment point and the convergence correction amount at the second adjustment point immediately below the first adjustment point. The amount of correction for each scanning line is determined by interpolation, and this interpolation circuit (
The output signal of step 6) is converted into an analog quantity by the D/A conversion circuit (7).

Since the output signal of the D/A conversion circuit (7) has a staircase waveform, it is smoothed by a low-pass filter (8), and after being amplified, it is supplied to a convergence yoke (not shown). Thereafter, similar operations are performed to correct other colors.

This conventional digital convergence correction device can perform convergence correction at each adjustment point on the screen independently, so that convergence correction can be performed with high precision.

However, the convergence correction amount must be written into the one-frame memory (5) for each adjustment point, which poses a problem in that the adjustment takes a very long time when the convergence shift amount is large.

Therefore, a digital convergence correction device that solves this problem is described in Japanese Patent Laid-Open No. 61-78294.

This digital convergence correction device includes a pattern memory that stores pattern data corresponding to a predetermined correction pattern (see FIGS. 4 and 5) within a predetermined area of the screen, and a It is equipped with a control means for varying the amount of correction and superimposing pattern data with the variable amount of correction on the correction data, and writing data for correcting a predetermined area in accordance with the correction pattern in the pattern memory. The control means takes in the pattern data selected from
The amount of correction based on the pattern data is adjusted by the control means and added to or subtracted from the correction data.

[Problems to be Solved by the Invention] Since the conventional digital convergence correction device is configured as described above, each of the digital convergence correction devices includes a 1/2 area divided into the top and bottom or left and right of the screen or four corners of the screen. Since the correction is made to make the 1/4 area into a predetermined pattern (see Figures 4 and 5), even though the symmetry of the screen is known, a correction pattern that divides the screen is used. Therefore, there was a problem that the adjustment time could not be further shortened.

The present invention was made to solve the above-mentioned problems, and an object of the present invention is to provide a digital convergence correction device that can further shorten the adjustment time.

[Means for Solving the Problems] A digital convergence correction device according to the present invention divides the screen of a color display device into m rows and n columns (m and n are integers) of adjustment points, and performs convergence correction of each adjustment point. a one-frame memory for digitally storing the amount; a storage means for storing a plurality of correction pattern components corresponding to the entire screen area; and a storage means for selecting a pattern to be corrected from among the correction pattern components stored in the storage means and selecting the correction amount for that pattern. The present invention is characterized by comprising a calculation means for creating convergence correction amount data to be stored in the one-frame memory by inputting the following.

[Operation] The digital convergence correction device according to the present invention divides the screen of a color display device into m rows and n columns (m,
(n is an integer) adjustment points, and the convergence correction amount for each adjustment point is digitally stored in a 1-frame memory, a plurality of correction pattern components corresponding to the entire screen are stored in the storage means, and the convergence correction amount for each adjustment point is stored in the storage means, and The convergence correction amount data to be stored in the one-frame memory is created by selecting a pattern to be corrected from the correction pattern components stored in the storage means and inputting the correction amount for the pattern.

[Example code] An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the digital convergence correction device has a control panel (21), and the control panel (21) includes an adjustment pattern selection key (
22) and a data amount setting key (23).

The control panel (21) has a memory (21) that stores a plurality of correction pattern components corresponding to the entire screen.
4a) and data for each pattern as a calculation means for creating convergence correction amount data by selecting a pattern to be corrected from the correction pattern components stored in the memory (24a) and inputting the correction amount for that pattern. A calculation microcomputer (24) is connected.

Furthermore, a data calculation microcomputer (2
4) is connected to a 1-frame memory (5) that stores the convergence correction amount;
) is connected to the D/A conversion circuit (7), and the D/A
A low pass filter (8) is connected to the conversion circuit (7).

Further, the digital convergence correction device has a synchronization signal input terminal (13), and a synchronization signal input terminal (13).
3) is connected to a crosshatch pattern generation circuit (15) and a horizontal/vertical position adjustment circuit (25), and the horizontal/vertical position adjustment circuit (25) is connected to an address counter (1).
6) is connected, and the address counter (16) is 1.
Connected to frame memory (5).

In addition, Figure 2 shows the misconvergence pattern on the screen before misconvergence correction.The deflection yoke uses the same magnetic field distribution, and the misconvergence pattern before correction basically has almost the same tendency. Become.

From this, if you break down this basic pattern into several types of patterns and adjust them to get the best fit, the adjustment time for the basic pattern can be reduced by adjusting each point on the screen one by one. It is possible to significantly shorten the time required.

Further, FIGS. 3A to 3C show typical decomposed misconvergence adjustment patterns in the case of an in-line cathode ray tube.

Ideally, by correcting these three types of patterns, the remaining amount of misconvergence becomes almost zero.

However, other adjustment patterns are normally required due to manufacturing errors (variations) in the deflection yokes and cathode ray tubes.

FIGS. 4A to 4C show examples of adjustment patterns used to correct manufacturing errors.

In order to correct manufacturing error components, it is sufficient to adjust approximately 20 types of patterns, including the example shown in Figure 3, and even in combination with the correction of the basic pattern, it is necessary to correct each adjustment point on the screen as in the past. Compared to other methods, the adjustment time can be significantly reduced.

Next, the operation of this embodiment will be explained.

When a synchronization signal is input from the synchronization signal input terminal (13), the crosshatch pattern generation circuit (15) projects a crosshatch pattern of 5 rows and 7 columns on the television screen (
(See Figure 6).

Note that the intersection of the crosshatches is the convergence adjustment point.

Then, depending on the state of misconvergence on the screen, an adjustment pattern is selected on the control panel (1), and the amount of correction for that adjustment pattern is set.

Then, the pattern-specific data calculation microcomputer (24) writes data for one screen into the one-frame memory (5) based on this data, and adjusts it to the scanning on the screen using the address counter (16) based on the synchronization signal. The correction data is called from the 1 frame memory (5),
It is converted into an analog quantity by the D/A conversion circuit (7).

Note that since the output waveform of the D/A converter circuit (7) has a step-like waveform, it is smoothed by a low-pass filter (8), and after amplification is supplied to a convergence yoke (not shown).

By repeating similar operations, misconvergence across the entire screen is corrected.

[Effects of the Invention] As explained above, according to the present invention, a plurality of correction pattern components corresponding to the entire screen area are stored in the storage means, and a pattern to be corrected is selected from among the correction pattern components stored in the storage means. Since the convergence correction amount data is created by inputting the correction amount of the pattern, the adjustment time can be further shortened without dividing the screen. This allows highly accurate digital convergence correction to be achieved in a short adjustment time.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the configuration of a digital convergence correction device according to an embodiment of the present invention, Fig. 2 is a diagram showing an example of a misconvergence pattern before digital convergence correction, and Fig. 3 is a correction using an in-line cathode ray tube. FIG. 4 is a diagram showing an example of a misconvergence pattern caused by manufacturing errors. FIG. 5 is a block diagram showing the configuration of a conventional digital convergence correction device. FIG. 7 and 8 are diagrams showing the projected state of the crosshatch pattern.
The figure is an explanatory diagram of a correction pattern used in a conventional digital convergence correction device and a change in the amplitude. In the figure, (5) is a one-frame memory, (24) is a pattern-based data calculation microcomputer, and (24a) is a memory. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] The screen of a color display device is divided into m rows and n columns of adjustment points (m and n are integers), and has one frame memory that digitally stores the convergence correction amount of each adjustment point. In a digital convergence correction device configured to perform convergence correction by reading out contents in synchronization with scanning of a color display screen, the digital convergence correction device includes a storage means for storing a plurality of correction pattern components corresponding to the entire screen area, and a correction pattern stored in the storage means. A digital convergence correction device comprising: a calculation means for selecting a pattern to be corrected from pattern components and inputting a correction amount for the pattern to create convergence correction amount data to be stored in the one frame memory.