JPS62193475A - Digital convergence device - Google Patents

Abstract

PURPOSE:To clearly display color to be adjusted by building in a switching function at a convergence correcting pattern signal output circuit. CONSTITUTION:A cross hatch 32 that is a convergence correcting pattern signal is generated at a hatch generator 25, and is displayed on a screen through a red, a green, and a blue output circuits 26-28. The intersection of the cross hatch 32 becomes an adjusting point. First of all, when the adjusting point is selected with a cursor key 21 on a control panel 1, a CPU2 finds the cursor address of the adjusting point, and sets it at a register at which a cursor 33 is displayed. Next, when a red or a green is selected with a selection key 22, the CPU2 turns off a switch built in the blue output circuit 28, and erases a convergence correcting pattern signal 31 of blue. In such a state, convergence corrections for the red and the green are performed looking at a picture plane with a write key 23, and a requested data is written at an address indicated by a one frame memory 3. And so forth, convergence dislocation for all of the adjusting points on the red and the green picture planes is corrected.

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.

Conventional technology A glossy mask color cathode ray tube (hereinafter abbreviated as CRT) used in color television receivers.
As is well known, it has three electron guns: red, green, and blue.

However, since it is structurally impossible to arrange all of these multiple electron guns on the central axis of the CRT, they are mounted slightly away 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 emits red, green, and blue fluorescent dots through the same hole, creating 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, CRT
At locations other than the central axis, the three electron beams converge in front of the shadow mask. Therefore, the three 'electron beams cannot pass through the same hole at the same time, and the reproduced image becomes more distorted, that is, the convergence shift increases as the distance from the center of the screen increases.

In order to prevent such problems, it is necessary to perform convergence correction so that the three electron beams converge at the shadow mask over the entire screen VC.

'Also, in a projection type color receiver that uses three CRTs that emit three primary colors to enlarge and project onto a screen, C
Since the angle of incidence of RT on the screen differs for each C and RT, color shift occurs on the screen.

For the superposition of these three primary colors, so-called convergence, a method is generally adopted in which a convergence correction waveform is obtained in an analog manner using passive elements such as L, C, and R, rather than a horizontal flyback pulse and a vertical deflection waveform. However, 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 cross/switch or digitally write one frame on the screen to the memory, read out this information for horizontal and vertical scanning, perform D/A conversion, amplify, and perform convergence correction. What is done will be explained below based on FIGS. 2 and 3.

First, as shown in FIG. 2, a crosshatch signal 34 indicating adjustment points in, for example, 9 columns in the horizontal direction and 7 rows in the vertical direction is output from the hatch generator 25 and displayed on the screen. The intersection of the crosshatches 32 on the screen becomes the adjustment point.

First, when an adjustment point is selected using the control panel 1 or the dial keys 21, the CPU 2 obtains the cursor address of that adjustment point, and displays the cursor 33 in the register.
1. At this time, the address of the 1 frame memory 3 is also found. Next, select the color to be corrected, for example red\, using the selection key 22, adjust it using the data write key 23 while looking at the screen, and write the desired data to the address specified in the 1-frame memory 3. The same process is then performed sequentially for green\, blue t, and blue-. Hereinafter, all adjustment points on the screen are similarly adjusted.

Next, reading out the convergence correction amount written in the 17 Rem memory 3 will be explained.

Since the one-frame memory 3 only has correction data for positions corresponding to the adjustment points shown in FIG. 2, it is necessary to perform interpolation for each scanning line between adjustment points in the vertical direction. Therefore, for example, using the correction data of the first and second rows read from the one-frame memory 3, the amount of correction in the scanning line included between the adjustment points of the first and second rows is calculated. It is determined by the interpolation calculation circuit 4. Next, the output signal of the interpolation calculation circuit 4 is
It is converted into an analog quantity by /A converters 5, 6, 7.8, smoothed by low pass 7 (/L/F (LPF) 9, 10, 11.12, and amplifiers 13, 14, 15, 16. After amplification, it is supplied to each color's convergence yoke.

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

However, in order to perform accurate convergence correction, the convergence correction pattern signal of the color to be corrected must be clearly visible. Therefore, when adjusting the red and green convergence, it is desirable to erase the blue convergence correction pattern signal.

Conventionally, in order to erase the previous convergence correction pattern signal, the screen volume 38 shown in FIG. 4 lowers the G2 voltage of the cathode ray tube 35 to erase the blue raster, or a specially provided switch shown in FIG. 5 is used. 41, a method was used in which the G2 voltage of the cathode ray tube 35 was lowered to erase the blue raster.

Problems to be Solved by the Invention However, in the above configuration, the screen volume controls 36, 3, and 38 shown in FIG. 4 must be adjusted every time the convergence is adjusted, or the switches 39, 4 shown in FIG.
In view of the above problem, the present invention has the problem that it is necessary to provide a 0.41 meter, and in view of the above problem, it is possible to adjust the screen volume or adjust the red and green without using a special switch.

Alternatively, the present invention provides a digital convergence device that can erase the blue convergence correction pattern and perform convergence correction with high accuracy.

Means for Solving the Problems In order to solve the above problems, the digital convergence device of the present invention automatically adjusts the blue convergence correction pattern when performing red to green cD-y7/Z-sense adjustment. It has a function of automatically erasing the red or green convergence correction pattern even when adjusting the blue convergence correction pattern.

Function: With the above-described configuration, the present invention automatically erases the blue (Z-turn for convergence correction) when the selection key provided on the control panel is operated, and displays only the red and green (Z-turns for convergence correction). It is possible to clearly identify convergence deviations using the monitor and make convergence adjustments 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 shows a digital convergence device in an embodiment of the present invention. In Figure 1, 26.2
7.28 is a pattern signal output circuit for convergence correction of red, green, and blue, and 29, 30.degree. 31 is a pattern signal of red, green, and blue. The other parts are the same as those in FIG. 3, and their explanation will be omitted.

The operation of the digital convergence device configured as described above will be explained using FIG. 1.

First, as shown in Figure 2, a crosshatch 3 which is a pattern signal for convergence correction showing 9x7 adjustment points on the screen.
2 is generated by the hatch generator 9, and the light output circuit 26.2 is generated by the hatch generator 9. Green output circuit 27. The image is displayed on the screen via the blue output circuit 28. The intersection of these crosshatches 32 becomes the adjustment point. First, when an adjustment point is selected with the cursor key 21 of the control panel 1, the CPU 2 obtains the cursor address of the adjustment point and sets the cursor 33 in the register for displaying. At this time, the address of 1 frame 3 is also obtained.

Next, when red l or green - is selected with the selection key 22, the CP
U2 detects this and controls the blue output circuit 28 to turn off the switch built in the blue output circuit 28,
The blue convergence correction pattern signal 31 is deleted.

In this state, red and green convergence correction is performed using the write key 23 while looking at the screen, and desired data is written to the specified address in the one-frame memory 3. In the same manner, the convergence deviation of all the red and green screen adjustment points is corrected.

Next, when blue or blue- is selected with the selection key 22, the CPU
2 detects this and controls the line output circuit 27 to turn off the switch built in the line output circuit 27, thereby erasing the green convergence correction pattern signal 30. In this state, the convergence shift of all adjustment points on the blue screen is corrected in the same way as above.

Next, the reading of the convergence correction amount written in the one-frame memory 3 is the same as in the conventional method (FIG. 3), and the explanation thereof will be omitted.

As described above, according to this configuration, the convergence correction pattern signal output circuits 26, 27, and 28 have a built-in switch that turns off the output, and this is controlled by the CPU 3 to adjust the convergence deviation between red and green. When this happens, the blue Talosno-itch signal 31 is erased and the red and green cross signal 31 is erased.
・The switch signals 29 and 30 are displayed clearly. Also, when adjusting the blue convergence shift, the red or green cross/notch signal 29 or 3Q is erased, and the red and blue or green and blue crosshatches are clearly displayed, so you can accurately adjust the convergence shift. Can be adjusted.

Effects of the Invention As described above, according to the present invention, the pattern signal output circuit for convergence correction has a built-in switch function, and when adjusting the convergence deviation between red and green, the switch of the blue output circuit is turned off and the blue output circuit is turned off. When erasing the blue signal and adjusting the blue convergence shift, turning off the switch of the red or green output circuit allows the color to be adjusted to be displayed clearly, allowing for accurate convergence adjustment. It can be carried out.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a digital convergence device according to an embodiment of the present invention, FIG. 2 is a front view showing a projected state of a crosshatch which is a pattern signal for convergence correction, and FIG. 3 is a diagram showing a conventional digital convergence device. A block diagram showing the configuration of the convergence device, and FIGS. 4 and 6 are circuit diagrams each showing a conventional method for erasing a crosshatch signal. 1...Control handle, 2...C
PU, 3...1 frame memory, 4...
・Interpolation calculation circuit, 5゜6.7.8...D/A converter, 9,10,11゜12...Low pass filter, 13,14,15゜16 ...Current amplifier, 22...Selection key, 23...Data write key, 24...Various control circuits, circuits,
29, 30. 31...Cross hatch signal. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure Kutta

Claims (1)

[Claims] Means for inputting position information of a plurality of convergence adjustment points in the horizontal and vertical directions on the screen of a color television receiver, means for correcting convergence deviation of the adjustment points, and means for generating a convergence correction pattern. and automatically erases the blue convergence correction pattern signal when correcting red or green convergence deviation, and automatically erases the red or green convergence correction pattern signal when correcting blue convergence deviation. A digital convergence device characterized by adjusting convergence.