JPS62135093A - Digital convergence device - Google Patents

Abstract

PURPOSE:To reduce the time necessary for the convergence-adjustment by executing the convergence-adjustment when the second synchronizing signal different from the preceding first synchronizing signal is inputted after transferring the convergence correction amount adjusted by the preceding first synchronizing signal to the second frame memory as it is. CONSTITUTION:When the first synchronizing signal is inputted, the signal is frequency-detected by a frequency detecting circuit 27, and the convergence adjustment is executed in the conventional method and stored the result in the first frame memory 10. The circuit operates with a switch 26 at (a)-side. In case the second synchronizing signal different from the first one is inputted, the said second signal is detected by the circuit 27, and whether or not the convergence-adjustment is already executed for the entire screen with the second synchronizing signal is discriminated. If already executed, the switch 26 is turned to (b)-side to supply the data in a second frame memory 24 to a vertical direction interinsertion processing section 13 via a register 25. If not yet executed, the data in the first frame memory 10 is transferred to the memory 24 by a transfer circuit 28 and then executes the convergence-adjustment.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a device for correcting the convergence of a color television receiver i, which can be adjusted with high precision and is fully compatible with input synchronization signals having different frequencies. The present invention relates to a possible low-cost digital convergence device.

Conventional technology Generally, color TV receivers use red and green.

An image is created by combining the three colors of blue on a phosphor screen or a projected screen, but in this case, accurately aligning the three colors, that is, convergence adjustment, is an important issue that affects image quality. Become.

Here, we will explain the convergence deviation using a projection type color television receiver as an example. In Fig. 2, 1 indicates the projection screen on which the image is projected, and 2, 3. It is a projection type cathode ray tube equipped with an optical lens that forms an image on the projection screen 1, and each fluorescent surface has three lights of red, green, and blue.
A color image is obtained.

As shown in Fig. 2, when these cathode ray tubes are arranged horizontally, the projection angle changes with respect to the projection screen 1 are different, so the projected raster is
A positional shift occurs as shown in the figure. In FIG. 3, the solid line 3β is the projection raster of green light from the cathode ray tube 3, and the dashed line 4
1 indicates a raster projected by the cathode ray tube 4 for blue light, and a dashed-dotted line 2β indicates a raster projected by the cathode ray tube 2 for red light.

In order to correct this positional shift, the projection type cathode ray tube 2.3
．． 4, a convergence adjustment coil is provided separately from the main deflection coil, and the amplitude of the sawtooth wave current in the horizontal scanning period is modulated in the vertical period, and the amplitude is adjusted independently for each color.

However, the amount of color shift varies due to variations in the mounting position of each cathode ray tube, variations in the configuration of the optical lens system, variations in the projection screen position, etc.
Highly accurate convergence adjustment cannot be achieved with a simple sawtooth wave current or a combination of parabolic currents.

As a method for realizing such convergence adjustment, a convergence circuit having a digital correction waveform forming section has been considered.

The conventional digital convergence device will be explained in detail below with reference to FIG.

Horizontal and vertical period pulses synchronized with the deflection current period are added as synchronization signals, thereby driving the read address control section 5. The pulse from the read address control section 6 is used to drive the crosshatch pattern generator 6 to project a crosshatch pattern on the projection screen. Figure 2 shows the crosshatch pattern generator. On the other hand, the address key of the control panel 12 is used to designate a cross point (for example, a person in FIG. 4) at a position that requires convergence correction, and the position address is set in the write address control section 8. Next, correction is performed and the amount of correction is written into the 1-frame memory 1o through the data reversible counter 11 while looking at the screen using the orange and red data write keys provided on the control panel 12. Normally, this one-frame memory writing is controlled by switching by the multiplexer Vx 9 so that it is performed during the blanking period of the video signal. Therefore, reading is not impaired.

Similar operations are performed at each adjustment point as described above. Next, the readout of the one frame memory 1o is performed by the readout address control unit 6 for the cross position of each crosshatch on the screen, and through the register 18 driven by the readout control unit 6, the data is read out by the vertical interpolation processing unit. At step 13, correction amount processing in the vertical scanning direction between crosshatches is performed. Next, FIG. 5 shows the operation of this correction process.

This will be explained with reference to FIG. The amount of correction for each scanning line between person and B or between C and 0 in FIG. 5 can be obtained from the equation (A-B)K. Here, K is the value obtained from linear approximation, and RO
I am writing to M. Therefore, it is clear that K can be determined from the number N of scanning lines between A and B. Further, the number of scanning lines N is determined from the number of scanning lines M in one field and the number of horizontal lines in the crosshatch.

Next, the correction amount processing between A and B in FIG. 5 will be explained with reference to FIG. 6. One frame memo IJ by read address control unit 6
The correction amounts of point A and point 8 read from register 10 are registered in register 1.18 and registers 2 and 19. The output signals of registers 1 and 2 are subjected to the calculation (person-B) by the subtracter 20, sent to the multiplier, multiplied by the coefficient for each scanning line to obtain (person-B)K, and then calculated by the adder 23. (A-B
)K-1-me is sent. In this way, the correction amount for the scanning line for which the correction amount is not stored is determined. Next, the output signal is converted into an analog quantity by the D/person converter 14. Next, the current is applied to the output amplification circuit section 16 through the low-pass filter 15, and a correction current is supplied to the convergence coil 17. Convergence adjustment at each adjustment point is performed as described above.

Problems to be Solved by the Invention However, in the above-described configuration, when the input synchronization signals are different (for example, different models of personal computers, or NTSG and high-definition TVs), each input synchronization signal is The convergence correction amount was adjusted accordingly and stored in the frame memory.

Therefore, the adjustment time becomes very long.

In view of this, the present invention detects an input synchronization signal, writes previously adjusted data to an unadjusted memory area if the frequency is unadjusted, and then performs adjustment, thereby reducing adjustment time. The purpose is to measure.

Means for Solving the Problems The present invention provides means for displaying a plurality of convergence adjustment points horizontally and vertically on the screen of a color television receiver, an input means for inputting position information of the adjustment points, and a receiver. a detection means for detecting at least two types of frequencies of an input synchronization signal; a first storage means for storing a convergence correction amount at a first frequency by the frequency detection means; and a convergence correction amount at a second frequency. a second storage means for storing the data, a transfer means for transferring the data of the first storage means to the second storage means, and a first storage means and a second storage means.
This digital convergence device includes switching means for switching and reading out the storage means using frequency detection means.

Operation The digital convergence device of the present invention has the above-described configuration, and when a different second synchronization signal is input, the convergence correction amount adjusted using the previous first synchronization signal is directly transferred to the second frame memory. The convergence adjustment time can be reduced because the adjustment is then performed.

Embodiment FIG. 1 shows a configuration diagram of a digital convergence device in an embodiment of the present invention. In FIG. 1, components that operate in the same manner as in the conventional example are designated by the same numerals, and explanations thereof will be omitted. 24 is a second frame memory that stores the digital convergence correction t in the second synchronization signal;
5 is a second register and is similar to the second register 18. 2
6 is the first frame memory 1o and the second frame memory IJ2
This is a switch that switches the output of 4. 27 detects the frequency of the synchronizing signal and controls the first frame memory 1o, the second frame memory 24, the switch 26, and the transfer circuit 28. 28
is a transfer circuit that transfers the data in the first frame memory 1o to the second frame memory 24.

The operation of the convergence device having the above configuration will be explained below.

First, when the first synchronization signal is input, the frequency detection circuit 27 detects the frequency and performs convergence adjustment in the first frame memory 1o in the same manner as in the conventional case. At this time, the switch 26 operates on the A side. Next, a case where a different second synchronization signal is input will be described.

When the frequency detection circuit 27 detects that it is the second synchronization signal, it determines whether or not the convergence of the entire screen has been adjusted using the second synchronization signal, and if it has been adjusted, the switch 26 is turned to the front side and the convergence of the entire screen is adjusted. The data in the 2-frame memory 24 is supplied to the vertical interpolation processing section 13 via the register 25.

If no adjustment has been made, the data in the second frame memory 24 will remain in the same state as when the power was turned on, and it will take a very long time to perform convergence adjustment from that state. Therefore, if the adjustment has not been made yet, the data in the first frame memory 1o is transferred to the second frame memory 24 by the transfer circuit 28, and then the convergence adjustment is performed. Convergence adjustment in the second frame memory 24 is performed in the same way as in the past, writing from the reversible data counter 11 to the second frame memory 24 via the transfer circuit 28, and reading is performed via the second register 25 and through the input side of the switch 26. Supplied to the vertical interpolation processing unit 13, D/A14°LP
FI 5 is supplied to the convergence coil via the output amplification circuit 16. In the manner described above, convergence adjustment at each adjustment point is performed.

As described above, according to the present invention, the frequency detection circuit 27 detects the frequency of the second synchronizing signal, determines whether it is unadjusted, and if it is unadjusted, the transfer circuit 28 transfers the Since the data is transferred to the 2-frame memory 24 and then the convergence adjustment is performed, the adjustment time can be shortened, which has a great practical effect.

As described in detail, according to the present invention, the adjustment time for comparability adjustment can be shortened.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a digital convergence device according to an embodiment of the present invention, Fig. 2 is a principle diagram of a projection type color TV receiver, Fig. 3 is a diagram for explaining the convergence deviation, and Fig. 4 is a block diagram of a digital convergence device according to an embodiment of the present invention. FIG. 6 is a block diagram of a conventional digital convergence device. FIG. 6 is a pattern diagram for explaining the device, and FIG. 6 is a partial block diagram for explaining the operation of the device. 5... Read address control section, 6...
・Crosshatch generator, 7... Video circuit, 8.
...Write address control unit, 9...Multiplexer, 10...First frame memory, 1
1... Data reversible counter, 12...
Control panel, 18...2nd register,
24... Second frame memory, 25...
・Second register, 26...Switcher, 27...
...Frequency detection circuit, 28...Transfer circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
figure! Figure 3

Claims (1)

[Claims] Display means for displaying a plurality of convergence adjustment points in horizontal and vertical directions on the screen of a color television receiver; input means for inputting position information of the adjustment points; and input means for inputting position information of the adjustment points; a detection means for detecting at least two or more types; a first storage means for storing a convergence correction amount at a first frequency by the detection means; and a second storage means for storing a second convergence correction amount by the detection means. A digital convergence device comprising: a transfer means for transferring data from the first storage means to a second storage means; and a switching means for switching between and reading out the first and second storage means using the detection means.