JPS6284691A - Digital convergence device - Google Patents

Abstract

PURPOSE:To allow a user to properly adjust a digital convergence device by providing the 1st detection means detecting the frequency of a synchronizing signal, and the 2nd detection means detecting a range out of that of the 1st detection means and displaying that the frequency concerned is out of a regulated frequency on a screen when the 2nd detection means detects a synchronizing frequency. CONSTITUTION:The limited synchronizing signal detects whether a frame memory 10 corresponds to the 2nd frame memory 24 or not in the 1st frequency detection detection circuit 26. According to the detected result, the 1st switch is switched, and the convergence device is adjusted in a way the same as a conventional one. If a synchronizing signal beyond the limited range is inputted, the 2nd frequency detection circuit 28 acts, sets the 2nd switch 29 to a side (b), whereby a dot signal in the dot generation means of the 2nd display means is displayed. Further the 3rd switch 30 is switched to the side (b), and convergence correction data at fixed values are supplied to a convergence coil from a fixed value output circuit 31. Accordingly the user can adjust the digital convergence in a proper way.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a device for correcting the convergence of a color television receiver fH1, 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 television receivers have red and green.

An image is created by combining the three colors of blue on a fluorescent surface 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, the convergence deviation will be explained using a projection type color television receiver as an example.

In FIG. 2, numeral 1 indicates a projection screen for projecting an image, and numerals 2, 3, and 4 are projection type cathode ray tubes each equipped with an optical lens for forming an image obtained on a fluorescent surface onto the projection screen 1. There are 3 colors of red, green, and blue on the fluorescent surface.
A color image is obtained.

As shown in Fig. 2, when these cathode ray tubes are arranged horizontally, the zero angle of projection with respect to the projection screen 1 is different, so the projected raster is
A positional shift occurs as shown in the figure. In FIG. 3, a solid line 34 is a projection raster of green light by the cathode ray tube 3, and a broken line 4
1 indicates a raster projected by the cathode ray tube 4 for blue light, and a dashed-dotted line 21 indicates a raster projected by the cathode ray tube 2 for red light.

To correct this positional shift, the projection type cathode ray tubes 2 and 3 must be
．． 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, since 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., it is necessary to use a simple sawtooth waveform to perform highly accurate convergence adjustment. This is not possible with electric currents or combinations of parabolic currents.

As a method for realizing such convergence adjustment, a convergence circuit with 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 periodic pulses synchronized with the deflection current period are applied as synchronization signals, thereby driving the read address control unit 6. The pulse from the read address control unit 5 is used to drive the crosshatch pattern generator 6 to project a crosshatch pattern on the projection screen. Figure 2 shows a crosshatch pattern. On the other hand, by using the address key on the control panel 12, a cross point at a position requiring convergence correction (for example, the mark in FIG. 4) is designated, and the position address is set in the write address control section 8. The color you want to correct next.

For example, by pressing the red data write key provided on the control panel 12, you can write the data reversible counter 11 while looking at the screen.
The correction amount is written into the 1-frame memory 1o through the 1-frame memory 1o.

Normally, this one frame memory is written to the multiplexer 9 during the blanking period of the video signal, as shown in row &'5.
Switching is controlled by Therefore, reading is not impaired.

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

Next, the operation of this correction process will be explained with reference to FIGS. 5 and 6. The amount of correction for each scanning line between M and 8 or between C and D in FIG. 5 can be determined from the formula (M-B)K+A.

Here, K indicates a value obtained by linear approximation and is written in the ROM. Therefore, it is clear that K can be determined from the number N of scanning lines between M and B. Further, the number of scanning lines N is determined by the number of scanning lines M in one field and the number of horizontal lines in the crosshatch.

Next, the correction amount processing between FIG. 6A and FIG. 6B will be explained with reference to FIG. One frame memo IJ by read address control unit 5
The correction amounts of points A and B read from 10 are registered in register 1.1B and register 2.19. The output signal of the register 1.2 is subjected to the operation (mu-B) by the subtracter 2o, sent to the multiplier, multiplied by the coefficient for each scanning line (mu-B), and then calculated by the adder 23. (A-B
)K-)-A is sent. In this way, the correction amount for the scanning line for which the τ correction amount is not stored is determined. Next, the output signal is converted into an analog quantity by the D/A converter 14. Next, it passes through the low-pass filter 16 and is applied to the output amplification circuit section 16 to supply a correction current to the convergence coil 17. Convergence adjustment at each adjustment point is performed as described above.

Problems to be Solved by the Invention However, with the above configuration, if the input synchronization signals are different (different models of personal computers etc. or
TS (j and high-definition TV), the convergence correction amount was adjusted according to the frequency of each input synchronization signal, and was stored in a plurality of frame memories. However, digital convergence equipment that can handle a wide variety of signal sources is
As frame memory capacity increases and costs increase,
Compatible with only limited types of signal sources. Therefore, for frequencies other than those limited to Celsius, the deflection system of the receiver is compatible, but the convergence, which requires high precision, is not operational.

In view of this, it is an object of the present invention to detect the frequency of an input synchronization signal and use this digital convergence device to inform the user of the device that only a limited synchronization signal can be used.

Means for Solving the Problems The present invention provides a first display means for displaying a plurality of convergence adjustment points in the horizontal and vertical directions on the screen of a color television receiver, and means for inputting position information of the adjustment points; A first detection means for detecting the frequency of the synchronization signal, a plurality of storage means for storing convergence correction amounts according to the first detection means, and means for reading the storage means according to the frequency of the input synchronization signal. A digital convergence device comprising: a second detection means for detecting an area outside the range of the first detection means; a second display means for displaying a result of the second detection means; and an output means for outputting a constant convergence correction amount. be.

Effects of the present invention With the above-described configuration, when the second detection means detects the synchronous frequency, it displays it on the screen to indicate to the user that the frequency is other than the specified frequency, thereby allowing the user to use the digital convergence device correctly. be.

Embodiment FIG. 1 shows a configuration diagram of a digital convergence device according to an embodiment of the present invention. Components that operate in the same manner as in the conventional example are designated by the same numerals, and a description of the operation will be omitted.

In FIG. 1, 24 is a second controller that adjusts and stores the convergence correction amount when synchronization signals of different frequencies are input.
frame memory; 26 is a second register; 26 is a first frequency detection circuit that detects the frequency of a limited synchronization signal;
Finally, the first switch 228 is a second frequency detection circuit that detects outside the limited frequency range, 29 is a second switch, 3o is a third switch, 31 is a constant value output circuit, and 32 is a circuit that detects outside the limited range. This is a second display means that is output and displayed when detected.

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

First, the case when a limited synchronization signal is input will be explained. The limited synchronization signal is detected by the first frequency detection circuit 26 as to whether it corresponds to the first frame memory 10 or the second frame memory 24, and if the synchronization signal corresponds to the first frame memo IJ 10, it is detected as Switch the switch to the A side,
If the synchronization signal corresponds to the second frame memory 24, the first switch is switched to the front side and adjustment is performed in the same manner as in the conventional case.

At this time, the second switch and the third switch are set to the A side. Next, if a synchronization signal outside the limited range is input, the second
The frequency detection circuit 28 operates, and the second switch 29 is turned to the opening side, and the dot signal from the dot generation section of the second display means is displayed. Furthermore, the third switch 3o is switched to the mouth side, and a constant value of convergence correction data is supplied from the constant value output circuit 31 to the convergence coil.

As described above, according to the present invention, the second frequency detection circuit 28 for detecting that the frequency of the limited synchronization signal is out of range is provided, and the second display means different from that when the limited synchronization signal is input, the constant value output circuit 31, and the second frequency detection circuit 28 are provided. By controlling the switch 29 and the third switch 30 as described above, the user can correctly adjust the digital convergence.

Note that although the second display means is generation of a dont signal, color or other display means may be used.

As described in detail, the present invention allows a user to correctly adjust a digital convergence device, and has great practical effects.

[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 Professional diagram of conventional digital convergence equipment. FIG. 5 is a pattern diagram for explaining the device, and FIG. 6 is a partial diagram for explaining the operation of the device. 5... Read address control section, 6...
1st display means, 8... write address control unit, 9... multiplexer, 1o... first frame memory, 11... data reversible counter,
12. Old control panel, 13. Vertical interpolation circuit, 18.2nd register, 24
...Second frame memory, 25...Second register, 26...First frequency detection circuit, 2
7...First switch, 28...Second frequency detection circuit, 29...Second switch, 30...
...Third switch, 31... Constant value output circuit,
32...Second display means. Name of agent: Patent attorney Toshio Nakao, 1st person, 2nd person
Figure 3

Claims (1)

[Claims] a first display means for displaying a plurality of convergence adjustment points horizontally and vertically on a screen of a color television receiver;
an input means for inputting position information of the adjustment point; a first detection means for detecting a frequency of a synchronization signal input to the receiver; and a plurality of memories for storing convergence correction amounts according to the detection means. and means for reading out the storage means according to the frequency of the input synchronization signal, the first
A digital convergence device comprising: a second detection means for detecting an area outside the range of the detection means; a second display means for displaying an image by the detection means; and an output means for outputting a constant convergence correction amount.