JPS5850882A - Digital convergence device - Google Patents

Abstract

PURPOSE:To project the convergence state of a TV receiver speedily by performing convergence adjustment automatically by the use of an image pickup element, and writting corrected data in a frame memory only when the convergence adjustment is completed. CONSTITUTION:Correction is made with cursor keys on a control panel 1 and an adjustment point is selected to turn a TV camera 25 in the direction, thus setting the adjustment point in its range. Then, a pattern generating circuit 15 for correction projects a dot in reference green and from its video signal, the dot position of the green is measured by a counter 26; and a red dot signal is then projected and its position is set in a counter 27. A comparator 28 compares the contents of the counters 26 and 27 with each other and the contents of a reversible counter 2 are increased or decreased so that both the contents coincide with each other, thereby writing the data in a frame memory 4 indicated by a cursor counter 9. The counter 2 reads the contents of the frame memory 4 specified by the counter 9 and sets them in the counter 2, thereby increasing or decreasing the data. The contents of the memory 4 are written in a memory 3 during blanking periods to adjust a horizontal position.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a convergence circuit for a color television receiver, and an object thereof is to provide a digital convergence device that can be adjusted quickly and with high precision.

In the shadow mask type color picture tube used in general color television receivers, the radius of curvature of the shadow mask is longer than the distance from the center of deflection to the center of the shadow mask, resulting in color shift. In addition, in projection-type color receivers that use three picture tubes that emit three primary colors to project enlarged images onto a screen, the angle of incidence of the picture tubes on the screen differs for each picture tube, so the colors appear on the screen. Misalignment occurs. The superposition of these three primary colors, so-called convergence, is performed by creating a correction waveform synchronized with the horizontal and vertical scanning cycles and adjusting this waveform. This method tends to have large convergence defects around the screen, and requires skill to adjust. For this reason, a method of digitally creating a convergence correction waveform has been proposed as a method of performing more accurate convergence over the entire screen.

This digital convergence method projects a convergence correction pattern such as a dot signal on the screen, digitally writes the convergence correction amount data for each point in one frame memory, and then scans this data horizontally and vertically. It is read out in synchronization with the scanning signal, performs D/A conversion, and creates a convergence correction waveform.

This will be explained in detail below with reference to FIGS. 1 and 2. First, as shown in Figure 1, on the screen, for example, there are 13 lines in the vertical direction and 9 lines in the horizontal direction.
A dot corresponding to the convergence adjustment point of the column is displayed by the control circuit 8 and the correction pattern generator 16 when a synchronization signal is applied from the synchronization input terminal 17. Next, as soon as the adjustment is made using the cursor keys on the control panel 1, the driver 6t corresponding to the adjustment point is selected. The address of the adjustment point selected with the cursor key 1 is stored in the cursor counter 9. The address stored in the cursor counter 9 is applied to the coincidence detection circuit 11 together with the address of the first one-frame memory control counter 12 which sequentially outputs the address of each adjustment point of the dot pattern, and When the output signal of the counter 12 and the output signal of the cursor counter 9 match, a match output signal is generated from the minus number generating circuit 11. The match output signal is then applied to the cursor generation circuit 14. The cursor generation circuit 14 generates a cursor signal corresponding to the storage address of the cursor counter 9. Next, the output signal of the cursor generation circuit 14 is added to the dot pattern signal of the correction pattern generation port/path 16 by the addition circuit 16, and the cursor is superimposed on the selected adjustment point on the television screen and displayed. .

After selecting the adjustment point as described above, the desired correction amount is set on the reversible counter 2 while viewing the screen using the writing key for the color to be corrected, for example, red provided on the control panel 1. Next, the output signal of the reversible counter 2 is written to the address specified by the cursor counter 9 of the first one-frame memory 3 via the data multiplexer 19. This first one-frame memory 3 is a storage element that can store information even when the power is turned off, such as a nonvolatile RAM or a ROM that can be electrically erased and written.
Consists of etc. Here, the first one-frame memory 3 and the second one-frame memory 4, which will be described next, will be explained. The first 1-frame memory 3 uses non-volatile RAM as described above, but this means that when adjusting the convergence of a television receiver, the correction data is retained even when the power is turned off. In addition to remembering this, convergence adjustment must be performed again due to misalignment of the electron gun of the television receiver that occurs when the television receiver is moved, or color shift due to misalignment of the panel as in the case of projection receivers. Therefore, a rewritable storage element must be used for the convergence correction data. However, since such an element generally has a very slow writing speed, the peripheral circuitry required to operate it at high speed in synchronization with a television receiver becomes complex. Therefore, when reading and writing operations are performed at high speed in synchronization with a television receiver, another high-speed memory is provided and correction data is transferred from the nonvolatile RAM to the high-speed memory to create a convergence correction waveform.

This high-speed memory is the second one-frame memory 4 in Figure 2.
It is.

When writing the correction amount to the first one-frame memory 3 as described above, the output of the reversible counter 2 is written. At this time, the address specified by the cursor counter 9 is written to the reversible counter 2 as the second address multiplexer 2
In addition to the second 1-frame memory 4 via 0, the contents of that address are read out. If you want to further increase the convergence correction amount, increase the reversible counter 2, and conversely, if you want to decrease it, decrease the reversible counter 2 and write the address specified by the cursor counter 9 in the first one-frame memory 3. Multiplexer 10 for first address
The contents of the first one-frame memory 3 are sequentially read out during the horizontal and vertical retrace periods by the first one-frame memory control counter 12. , the second one-frame memory control counter 13 sequentially performs write correction in the second one-frame memory 4 during the horizontal and vertical retrace periods.
゛Next, reading from the second one-frame memory 4 will be explained.

The second one-frame memory is read out in synchronization with the dot pattern shown in FIG. 1 by the address signal output from the second one-frame memory control counter 13. However, since the second one-frame memory 4 only has correction amount data for locations corresponding to adjustment points, including virtual 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 uses, for example, A in FIG.
The correction amount for each walking line included between the A point and the B point is determined by interpolation from the correction amount of the A point and the correction amount of the B point. Next, the output signal of this high interpolation circuit 6 is converted into an analog signal by a D/A converter 6. Since the output signal of the D/A converter 6 has a staircase waveform, it is supplied to a low frequency coil (not shown). The red color has been explained above, but the correction for green and blue colors is also the same. Also, when using green as the reference, match the green no (red or - blue) to the turn signal.

Such a digital convergence device can perform convergence correction at each adjustment point independently, so that convergence correction can be performed with high accuracy.

However, in the digital convergence device as described above, the correction data from the reversible counter 2 is written into the first 1-frame memory 3, and then the first 1-frame memory 3 is sequentially read out and horizontally read out.

It is written during the vertical retrace interval and then read out in synchronization with the television receiver's dot pattern. For that reason,
It takes time for the rewritten and corrected convergence state to be displayed. It goes without saying that as the number of adjustment points increases, it takes longer to transfer and it takes longer for the convergence state to be displayed. Also, the corner portions' of the screen (portions 21, 22, 23, indicated by dotted lines in Figure 1).
24), if the correction amount f of one adjustment point is changed, the correction amounts of three points must be calculated by the extrapolation calculation circuit 18 and written into the first one-frame memory 3.

For example, when adjusting point a in Figure 1 21, Figure 1 c, d
, the correction data for point e must be rewritten. Therefore, at the part where the color shift is the largest (corner part),
It takes an extra long time to rewrite the correction data in the first one-frame memory 3, and quick adjustment cannot be performed.

The present invention eliminates the above-mentioned drawbacks and provides a reversible counter 2.
To provide a convergence device that efficiently writes the contents of a frame into a second frame memory 4, stores convergence correction data in a first frame memory 3, and automatically performs adjustment using an image sensor. It is something to do.

Hereinafter, one embodiment of the present invention will be described with reference to FIG. In FIG. 3, components that perform the same operations as in FIG. 2 are designated by the same numbers, and their explanations will be omitted.

The present invention uses an image pickup device (such as a camera) and performs the first one frame only when the automatic sense adjustment is completed. Therefore, in the past, every time the reversible counter 2 was increased or decreased, it was written in the first one-frame memory 3 and then transferred to the second one-frame memory 4, but in the present invention, -
Since the contents of the reversible counter 2 are directly written into the second one-frame memory 4, the current state of the television receiver can be immediately displayed.

The operation will be explained in detail below, but in order to make it easier to understand,
The reference point on the plywood is set to green and red correction is performed.

In Fig. 3, select the adjustment point you want to correct using the cursor keys on the control panel 1, then point the TV camera 26 in that direction and set the adjustment point so that it is inside the TV camera (Fig. 4). (set it so that you can get the image shown in the picture)

Next, a reference green 1 dot is displayed by the correction pattern generating circuit 16. Then, a green horizontal position counter 26 that counts clock pulses from the signal is set in the television camera, and the position of the green dot in the screen of the television camera 26B is measured by replacing it with time. Next, a red dot signal is projected onto the correction pattern generation circuit 16,
Similar to the green one, the red horizontal position counter 27 is set this time.

After detecting the horizontal position of the red dot, the comparator 28 compares the contents of the green horizontal position counter 26 and the red horizontal position counter 27, and sets the data reversible counter 2 so that they match.
, and writes it to the second 17-ray memory 4 at the address specified by the cursor counter 9 during the horizontal or vertical retrace period. In this case, the reversible counter 2 reads the contents of the A and RERES specified by the cursor counter 9 of the second 1-frame memory 4, writes the contents to the reversible counter 2, and increases or decreases the data. let Next, the red and green horizontal position counters 26°2□. +i
□□Yu, 8 Todoroki 1, -, Oi, Pa Stop the increase/decrease of reversible counter 2.

Next, the contents of the second 1-frame memory 4 at the address specified by the cursor counter 9 are horizontally scanned.

Read in the vertical retrace period, the first 1' frame memory 3. Write to the address specified by the cursor counter 9, and complete the horizontal position convergence adjustment. Next, the first and second one-frame memories 4 are read, and this operation is similar to that described in the conventional example.

Although the horizontal direction of red color has been described above, the convergence adjustment of vertical direction and blue color is also the same.

As described above, according to the present invention, in order to write to the first one-frame memory, which is a non-volatile memory, after the adjustment of one adjustment point is completed, an element with a slow writing speed of the non-volatile memory is used. convergence adjustment can be performed quickly even when Also, directly to the second 1 frame memory,
Correction data only for that adjustment point (contents of reversible counter 2)
Since the convergence state of the television receiver can be displayed quickly, it is possible to quickly display the convergence state of the television receiver.
3

[Brief explanation of the drawing]

Fig. 1 is a pattern diagram when a correction pattern signal of a digital convergence device is displayed on a television receiver, Fig. 2 is a block diagram of a conventional digital convergence device, and Fig. 3 is an embodiment of the present invention. A block diagram of the digital convergence device in the example, FIG. 4a is a diagram showing each adjustment point on a television receiver, and FIG.
Figure 4 shows one adjustment point captured by a TV camera.
Figure C is a waveform diagram of a video signal when the green dot is photographed by a television camera. 1...Control channel, 9...Cursor counter, 11...-number output circuit, 1o.
...Multi-switch lexer for 1st address, 12...
1st 1-frame memory control circuit, 3... 1st 1-frame memory, 26... TV camera,
26... Green horizontal position counter, 27...
,・Red horizontal position counter, 28... Comparator, 2
・・・・・・Reversible force;, 1 ・Ul-1・L Multi-7 lexer for 2nd address, 4・・・・・・ 4 2nd 1 frame mori, 13 ・・・・2nd 1 frame memory control circuit, 6...Interpolation calculation circuit, 1
8... Extrapolation calculation circuit, 14... Cursor generation circuit, 16... Correction pattern generation circuit, 16... Addition circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
11. Shear-2j7 m, --” ° °1° °
°I-J 4 II4 Figure

Claims (1)

[Claims] means for generating a pattern that enables convergence adjustment at multiple points in the horizontal and vertical directions on a screen of a color television receiver; means for inputting positional information of the convergence adjustment points; and a screen including the convergence adjustment points. an imaging means for enlarging and detecting a part of the imaging means; a means for correcting a convergence deviation using an output signal of the imaging means; and a first apparatus for storing correction data obtained by the means for correcting the convergence deviation as non-volatile information. and a second storage means that stores the correction data and reads out with a clock signal synchronized with the horizontal deflection and the vertical deflection, and the means for storing the convergence correction data stores the correction data during the convergence adjustment. is stored in the second storage means, and only correction data after completion of convergence adjustment is stored in the first storage means.