JPH02154593A - Digital convergence device - Google Patents

Abstract

PURPOSE:To speed up correction and to improve accuracy by obtaining the correction quantity of scanning lines of every several pieces during convergence correction, substituting the correction quantity for a scanning line above or below the scanning line, and obtaining the correction quantity of every scanning lines after the lapse of specific time from the completion of adjustment or when an adjustment point is moved. CONSTITUTION:When a convergence adjustment is executed with the adjustment key of a control panel 12, the correction quantity of every 3 pieces, for instance, is obtained, and for scanning lines excluding the scanning line of which correction quantity is obtained, a correction quantity 1 equal to the obtained correction quantity of the scanning line being located above or below the scanning line of which correction quantity is not obtained is written in 1-frame random access memory 9. When a specific time passes from the completion of adjustment key operation, or when the adjustment point is moved to another place, interpolated operation is executed to the correction quantity of each of the scanning line, and the wiring of 1-frame random access memory is executed. Thus, time for the convergence adjustment necessary for every adjustment points is greatly shortened, the convergence adjustment of a whole picture can be speedily and accurately executed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a digital convergence device that can quickly and accurately adjust convergence correction in a color television receiver.

2. Description of the Related Art As is well known, a shadow mask type color cathode ray tube (hereinafter abbreviated as CRT) used in general color television receivers has red, green, blue and Miki electron guns. However, since it is structurally impossible to arrange all of these multiple electron guns on the central axis of the CRT, they are mounted a little apart from the central axis and slightly tilted inward with respect to the central axis. Therefore, on the screen on this central axis, each electron beam converges at the shadow mask, and at the same time emit red, green, and blue fluorescent dots through the same hole, resulting in a convergence state.

However, since the radius of curvature of the shadow mask is larger than the distance from the center of deflection to the center of the shadow mask,
At locations other than the central axis of the CRT, the three electron beams converge in front of the shadow mask. Therefore, three electron beams cannot pass through the same hole at the same time, and the color shift, that is, the convergence shift, of the reproduced image increases as it moves away from the center of the screen. To prevent this kind of inconvenience, set the shadow mask to 3 over the entire screen.
It is necessary to perform convergence correction so that the book's electron beam converges.

Furthermore, in a projection type color television receiver that uses three CRTs that emit light in three primary colors to enlarge and project images onto a screen, color shift occurs on the screen because the angle of incidence of the CRT on the screen differs for each CRT.

The superposition of these three primary colors, so-called convergence,
- For boat fishing, a method is used to obtain a convergence correction waveform in an analog manner using passive elements such as L, C, and R, rather than a horizontal flyback pulse and a vertical deflection waveform.
There is a problem with convergence accuracy.

In contrast, a method of digitally performing convergence correction has been proposed as a method of performing convergence with higher precision. The concept is to project a convergence correction pattern such as a crosshatch on the screen, digitally write the convergence correction amount data for each intersection in one frame memory, and synchronize this information with horizontal and vertical scanning. The data is read out, subjected to D/A conversion, amplification processing, and convergence correction.

An example of the digital convergence correction described above will be described below with reference to the drawings.

Fig. 2 is a diagram showing the state of the screen after convergence correction has been performed for each scanning line, Fig. 3 is a block diagram of the digital convergence device, and Fig. 4 is a diagram showing the screen state after convergence correction is performed for each scanning line. FIG.

As shown in FIG. 4, crosshatches 24 indicating adjustment points in, for example, 9 columns in the horizontal direction and 7 rows in the vertical direction are displayed on the screen from the convergence adjustment signal output terminal 17 of the control section 7.

The intersection of these crosshatches 24 becomes the adjustment point. The control unit 7 receives signals input from the horizontal synchronization signal input terminal 18, vertical synchronization signal input terminal 19, and clock input terminal 20, and digital convergence control data of the data buffer random access memory 11, CPU, and nonvolatile one frame memory. 10.1 frame random access memory 9, data buffer random access memory 11
It generates a control signal 21 to control the digital convergence device, outputs a pattern signal for convergence correction, and interfaces the control panel 12 and the CPU 8.

First, when an adjustment point is selected on the control panel 12 of FIG. 3, the CPU 8 obtains the cursor address of the adjustment point. At this time, the addresses of the nonvolatile one-frame memory 10 and data buffer random access memory 11 are also obtained. In addition, in the data buffer random access memory 11, a stack area and a working area used by the CPU 8 are allocated to an area that stores digital convergence control data and correction amounts for all adjustment points of the crosshatch 24. After the above operation, the control unit 7
displays a cursor 25 at the corresponding adjustment point on the screen. Next, input the color you want to correct from the control panel 12, look at the cursor 25 on the screen that indicates the selected adjustment point, perform convergence adjustment using the adjustment keys on the control panel 12, and adjust the desired amount of correction using the random access for data buffer. Write to the previously specified address in the memory 11. When a certain period of time has elapsed after the adjustment key operation is completed, the above-mentioned correction amount is written into the non-volatile one frame memory 10. The same procedure is then performed for all adjustment points sequentially. Hereafter, the same process is performed for other colors.

Next, reading out the convergence correction amount written in the data buffer random access memory 11 will be explained. Since the correction amounts written in the data buffer random access memory 11 are only for the positions corresponding to the adjustment points shown in FIG. 4, it is necessary to perform interpolation for each scanning line between adjustment points in the vertical direction. . Therefore, for example, the data buffer random access memory 11
Using the correction amounts of the first and second lines read from the CPU 8, the correction amounts for each scanning line included between the adjustment points of the first and second lines are determined by the CPU 8 as described later. It is obtained by approximate calculation and written to the Eframe random access memory 9. After that, the one frame random access memory 9
Read the correction amount for each scanning line written in the D/A
The signal is converted into an analog signal by a converter 13, smoothed by a low pass filter (LPF) 14, amplified by an amplifier 15, and then supplied from a convergence correction signal output terminal 16 to a convergence coil (not shown).

The above approximate calculation is obtained as follows. As shown in Figure 2, for example, when moving the red crosshatch 1 in the first row from point A to point A'' on the green crosshatch 3, the amount of correction is a, and the point B in the second row is Let the amount of correction when moving to point B' be b (in the case of Figure 2, the amount of correction is O because point B on the second line is uncorrected).The amount of correction on this first line The amount of change for each scanning line between the adjustment points is determined from a and the correction amount of the second row, and the amount of correction for each scanning line is determined by adding this amount of change and the amount of correction of the second row. That is, the correction amount of the adjustment point of the n-th grain (05M) from the second line is written to the nonvolatile 1-frame memory 10, but this is to back up the correction amount of each adjustment point. If the power is turned off, the correction amount written in the data buffer random access memory 11.1 frame random access memory 9 will be erased.However, each adjustment point written in the nonvolatile 1 frame memory 10 will be erased. Therefore, when the power is turned on, the correction amount for each adjustment point stored in the non-volatile 1-frame memory 10 is written to the data buffer random access memory 11, and Random access memo January 1
By interpolating the correction amount for each adjustment point written in the CPU 8 and writing the correction amount for each scanning line into the 1-frame random access memory 9, it is possible to eliminate the trouble of re-adjusting every time the power is turned on. can.

Now, as can be seen from the descriptions so far, in the digital convergence device, the CPU 8 performs key scans on the control panel 12, changes in the amount of correction at each 81 adjustment point,
Processes such as interpolation calculation for determining the correction amount for each scanning line from the correction amount at each adjustment point, writing of the correction amount for each scanning line into the frame random access memory 9, horizontal frequency detection, etc. are performed. However, if the CPU processing described above is performed during the vertical scanning period, the screen will be affected and the image will be distorted. Therefore, in order to avoid affecting the image displayed on the screen, the CPU 8 is operated only during the vertical blanking period (as the horizontal blanking period during the vertical scanning period is short, the CPU 8 is stopped). During the vertical scanning period, the CPU 8 stops operating, and uses a control signal output from the control unit 7 to output the correction amount for each scanning line stored in the one-frame random access memory 9 to the D/A converter. Convergence correction is being performed.

In the digital convergence device described above, the adjustment points can be arbitrarily corrected independently, so that convergence correction can be performed with high accuracy.

Problem to be Solved by the Invention The amount of correction for each scanning line is obtained by interpolating the amount of correction at adjustment points above and below that scanning line using the CPU.
Since the operating period of the PU is set to the vertical blanking period, it takes a considerable amount of time to perform the interpolation calculation to obtain the correction amount for each scanning line.

In the conventional system, even if the adjustment point selected on the control panel is changed continuously by pressing the adjustment key on the control panel, the correction value is changed every time the correction amount data increases or decreases by one. The amount of correction for each scanning line between the adjustment point selected in Correction takes a long time. Therefore, it took a considerable amount of time to perform convergence adjustment for all adjustment points on the screen.

In view of the above-mentioned problems, the present invention does not calculate the correction amount for each scanning line when adjusting the convergence, but calculates the correction amount for every third scan line, and For scanning lines other than lines, write the same correction amount as the correction amount for the scanning line above or below that scanning line in one frame random access memory, and keep it constant after you stop operating the adjustment key. When time passes or when the adjustment point is moved to another location, quick convergence adjustment can be performed by interpolating the correction amount for each scanning line and writing it to the random access memory for one frame. The present invention provides a device that can perform the following functions.

Means for Solving the Problems In order to solve the above problems, the digital convergence device of the present invention does not calculate the correction amount for each scanning line when adjusting the convergence, but instead calculates the amount of correction for each scanning line, for example. Calculate the correction amount every other time, and apply the same correction amount to the scanning line above or below the scanning line other than the one for which the correction amount was calculated using one-frame random access. If a certain period of time has passed since you stopped operating the adjustment key, or if you moved the adjustment point slightly, the correction amount for each scanning line is interpolated and stored in the random access memory for one frame. It is designed to perform processing such as writing.

According to the present invention, since the convergence adjustment time required for each adjustment point can be significantly reduced, the convergence adjustment for the entire screen can be performed quickly and with high precision.

Embodiment Hereinafter, a digital convergence device according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing a correction state near a selected adjustment point during convergence adjustment in an embodiment of the present invention,
Fig. 2 is a diagram showing the state of the screen when convergence correction is performed for each scanning line, Fig. 3 is a block diagram of the digital convergence device, and Fig. 4 is a diagram showing the image of the cross hatch which is the convergence adjustment signal. FIG.

As shown in FIG. 4, adjustment points arranged in, for example, 9 columns in the horizontal direction and 7 rows in the vertical direction are displayed on the screen using a crosshatch 24 to the control section 7 from the convergence adjustment signal output terminal 17. The intersection of these crosshatches 24 becomes the adjustment point. Note that the control unit 7
is horizontal synchronization signal input terminal 18 vertical synchronization signal input terminal 19
, the signal input from the clock input terminal 20 and the random access memo for the data buffer From the digital convergence control data of January 1st, the CPU 8, the non-volatile 1 frame memory 10, the frame random access memory 9
, data buffer random access memo January 1, etc. to control the digital convergence device, output a pattern signal for convergence correction, and interface between the control panel 12 and the CPU 8.

First, when an adjustment point is selected on the control panel 12 of FIG. 3, the CPU 8 obtains the cursor address of the adjustment point. At this time, the addresses of the nonvolatile one-frame memory 10 and data buffer random access memory 11 are also obtained. In addition to an area for storing digital convergence control data and correction amounts for all adjustment points of the crosshatch 24, a stack area and a working area used by the CPU 8 are allocated to the data buffer random access memory 11. After the above operation, the control unit 7 displays the cursor 25 at the corresponding adjustment point on the screen. Next, input the color you want to correct using the control panel 12, and use the second cursor 25 on the screen to indicate the selected adjustment point.
, perform convergence adjustment using the control panel adjustment keys, and write the desired correction amount to the previously specified address of the data buffer random access memory 11. At this point, only the selected adjustment point has been corrected, so it is necessary to perform correction for each scanning line between the selected adjustment point and the adjustment points above and below it. The correction amount for each scanning line is determined by the CPU performing approximate calculations as will be described later from the correction amounts of the selected adjustment point and the adjustment points above and below it.

The above approximate calculation will be explained with reference to FIG. As shown in Figure 1, for example, red crosshatches 1 and 4
Green crosshatch 1 from adjustment point A in the first row and first column of
A in the first row and first column of 3.

The amount of correction when moving up to a is the amount of correction when moving from adjustment point B in the second row, first column of red crosshatch 2 to B' in the second row, first column of green crosshatch. b
(In the case of FIG. 1, since point B is uncorrected, the amount of correction at point B is 0).

If the number of scanning lines included between the crosshatches in the first and second rows is M, then the number M' of every third scanning line is expressed by the following equation.

M' - M/β (round down to the nearest whole number) Here, β needs to be a value that does not make the screen too difficult to view. By subtracting the correction amount a of the first line and the correction amount of the second line and dividing it by M, the change for each scanning line selected between the adjustment points is calculated, and this change and the second The correction amounts for each selected scanning line are determined by adding together the correction amounts for the rows.

2nd row crosshatch 2 to n' wood grain n''≦M')
In this case, the correction amount of the interpolated scanning line above or below that scanning line is used as the correction amount. Figure 1 shows β-3, which is obtained by substituting the correction amount of the interpolated scanning line below that scanning line for the correction amount of the scanning line other than the interpolated scanning line. .

The correction amount for each scanning line between the adjustment points determined as described above is written into the address corresponding to each scanning line in the one-frame random access memory 9. Thereafter, the correction amount for each scanning line written in the 1-frame random access memory 9 is read out, converted into an analog signal by the D/A converter 13, smoothed by the low-pass filter (LPF) 14, and smoothed by the amplifier 15. The amplified convergence correction signal is supplied from the output terminal 16 to a convergence coil (not shown).

Then, if a certain period of time has passed after the adjustment key operation at the selected adjustment point, or if the adjustment point has been changed, the scanning line 1
Approximate calculations, which will be described later, are performed on the correction amount for one frame, and the calculation results are written to the corresponding addresses in the one-frame random access memory 9, thereby making it possible to perform highly accurate convergence adjustment. Note that at this time, the correction amount of the adjustment point is simultaneously written into the nonvolatile one-frame memory 106.

The same procedure is then performed for all adjustment points sequentially. Hereafter, the same process is performed for other colors.

The above approximate calculation will be explained with reference to FIG. As shown in Figure 2, for example, a red crosshatch 1.4
Green crosshatch 1 from adjustment point A in the first row and first column of
The amount of correction when moving to A' in the first row and first column of 3 is a, and from adjustment point B in the second row and first column of red crosshatch 2 to the second row of green crosshatch 3. 1st row B”
The amount of correction when the point is moved up to the point is b (in the case of FIG. 1, point B is uncorrected, so the amount of correction at point B is O).

From the correction amount a of the first line and the correction amount S of the second line, the change for each scanning line between the adjustment points is calculated, and this change and the correction amount S of the second line are added together. Find the correction amount for each line. That is, if the number of scanning lines included between the crosshatches in the first and second lines is M, then the correction amount of adjustment points of n main openings (n5M) from the second line is stored in the non-volatile one frame memory 10. This is written in order to buffer the correction amount for each adjustment point. When the power of the digital convergence device is turned off, the correction amounts written in the data buffer random access memory 11 and the frame random access memory 9 are erased. However, the written correction amounts for each adjustment point are stored in the nonvolatile one-frame memory 10 as they are. Therefore, when the power is turned on, the correction amount for each adjustment point stored in the non-volatile one frame memory 10 is written to the data buffer random access memory 11, and each adjustment written in the data buffer random access memory 11 is By performing the process of interpolating the correction amount of a point in the CPU 8 and writing the correction amount for each scanning line into the 1-frame random access memory 9, it is possible to eliminate the trouble of re-adjusting every time the power is turned on. can.

As described above, with this configuration, by changing the method of interpolation calculation during convergence adjustment and convergence correction, convergence adjustment can be performed accurately and quickly.

Effects of the Invention As described above, the present invention enables convergence adjustment to be performed accurately and quickly by changing the method of interpolation calculation during convergence adjustment and convergence correction.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the correction state near a selected adjustment point during convergence adjustment in an embodiment of the present invention, and FIG. 2 is a diagram showing the state of the screen when convergence correction is performed for each scanning line. FIG. 3 is a block diagram of the digital convergence device, and FIG. 4 is a diagram showing a state in which a crosshatch, which is a convergence adjustment signal, is projected. 1... Red and green first row crosshatch, 2
・・・・・・Red and green second row crosshatch, 3.
・・・・・・Green crosshatch in the first row, 4・・・・・・
Red crosshatch in the first row before correction, 5... Scanning line, 6... Red crosshatch in the first row after correction, 7... Control unit, 8. ...CPU, 9.
...1 frame random access memory, 10.
...Non-volatile 1 frame memory, 11...
・Data buffer memory, 12... Control panel, 13... D/A converter, 14...
...L P F, 15...Amplifier, 16.
...Convergence correction signal output terminal, 17...
...Convergence adjustment signal terminal, 18...
...Horizontal synchronization signal input terminal, 19...Vertical synchronization signal input terminal, 20...Clock input terminal, 2
1...Control signal, 22...Address bus, 23...Data bus, 24...Cross hatch projected on screen, 25...・・・
cursor.

Claims (1)

[Claims] means for generating a convergence correction pattern such that the screen of a color television receiver has a plurality of convergence adjustment points in the horizontal and vertical directions; and inputting position information of the convergence adjustment points into a data buffer random access memory. means for writing the correction amount of the specified adjustment point into the corresponding address of the data buffer random access memory and the nonvolatile one frame memory; and means for writing the correction amount corresponding to all the scanning lines into the data buffer random access memory. It is provided with a means for calculating by approximate calculation using the correction data of the adjustment point read from the above and writing it to the address corresponding to the scanning line of the 1-frame random access memory, and if convergence correction is in progress, the selected adjustment point and the adjustment points above and below it. Instead of calculating the correction amount for all the scanning lines in between, calculate the correction amount for every few scanning lines, and calculate the correction amount above or below the scanning line for the scanning line other than the one for which the correction amount was calculated. Substituting the same correction amount as the calculated scanning line correction amount, if a certain period of time has passed after the adjustment key operation is completed, or if the adjustment point is moved, one scanning line
A digital convergence device characterized by performing processing to obtain a correction amount for a book.