JPS6163177A - Digital convergence device - Google Patents

Abstract

PURPOSE:To suppress voltage which is incited during a BLK period in the horizontal direction and to decrease power consumption of a device by reading a corrected quantity stored at a storing means and operating a corrected quantity during a fly-back line period from the corrected quantity of adjusting points outside a picture. CONSTITUTION:A reading address control part 5 is driven by a synchronizing signal by a horizontal and vertical pulse which synchronizes to a deflecting current, and a pattern from a cross hatch generating device 6 is added to a video circuit 7 and indicated by a read pulse. A cross point located at a position to correct convergence with an address key of a control panel 12 is designated and set to a writing address control part 8. Next, the data are set to a frame memory 10 by a reversible counter 11 and corrected data of an address set to a memory 10 are read at a BLK period corrected quantity operation processing part 19. A corrected quantity of a fly-back period is operated from the corrected quantity of the corrected quantity of an adjusting point outside the picture at the processing part 19, voltage, which is induced during the BLK period in the horizontal direction, is suppressed and power consumption of a device is decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a device for correcting the convergence of a color television receiver, and relates to a digital convergence device that can be adjusted accurately and consumes little power.

Conventional configuration and its problems Generally, color television receivers have red and green.

Images are created by combining the three primary colors of blue on a phosphor 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 shift will be explained using a projection type color television receiver as an example.

In FIG. 1, numeral 1 indicates a projection screen for projecting an image, and numerals 2, 3, and 4 indicate a projection type picture tube equipped with an optical lens for forming an image obtained on a fluorescent surface onto the projection screen 1. Three color images of red, green, and blue are obtained on each fluorescent surface.

As shown in Figure 1, when these picture tubes are arranged horizontally, the projection angles relative to the projection screen 1 are different, so the projected raster will have a positional shift for each color as shown in Figure 2. arise.

In FIG. 2, a solid line 32 shows a raster projected by the picture tube 3 for green light, a broken line 4β shows a raster projected by the picture tube 4 for blue light, and a dash-dotted line 22 shows a raster projected by the picture tube 2 for red light.

To correct this positional shift, use a projection picture tube of 2°3.4
It is sufficient to provide a convergence adjustment coil separately from the main deflection yoke, amplitude-modulate the sawtooth wave current in the horizontal scanning period in the vertical period, and adjust the amplitude independently for each color.

However, this amount of color shift is due to variations in the mounting position of each picture tube, variations in the configuration of the optical lens system, etc.
Since the convergence varies depending on changes in the projection screen position, etc., it is impossible to perform highly accurate convergence adjustment with a combination of a simple sawtooth wave current or a parabolic current.

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 pulses from the read address control section 5 are used to drive the cross-hatch pattern generator 6 to project a cross-hatch pattern on the projection screen. Figure 2 shows the crosshatch pattern. On the other hand, use the address key of the control panel 12 to select the cross point at the position where convergence correction is required (for example, A in Fig. 4).
, and set the position address in the write address control unit 8. Next, using the data write key of the color to be corrected, for example, red provided on the control panel 12, write the correction amount into the one frame memory 10 through the data reversible counter 11 while looking at the screen. Normally, this one-frame memory writing is controlled by switching by the multiplexer 9 so that it is performed during the video signal blanking period. Therefore, reading is not impaired.

Similar operations are performed at each adjustment point as described above. Next, the one-frame memory 1o is read by the read address control section 5 for each cross position of Kuromeno Tsuchi on the screen, and is read out from the vertical direction insertion through the register 18 driven by the read address control section. The inter-processing section 13 performs correction amount processing in the vertical scanning direction between crosses and edges, and obtains correction amounts for scanning lines for which no correction amounts are stored. Furthermore, the amount of correction for the BLK period in the horizontal direction is the same as the amount of correction for the adjustment point outside the screen. Next, the output signal is converted into an analog quantity by the D/A converter 14 shown in FIG.
) 15, the correction amount in the horizontal direction is smoothed and applied to the output amplifying section 16, which supplies a correction current to the concentric coil 17. As described above, adjust each adjustment point (
- Adjusting the sense 0 However, conventional digital computer
In the device, the correction amount for the BLK period in the horizontal direction is the same as the correction amount for the adjustment point outside the screen, so between the correction amount for the BLK period and the correction amount for the other adjustment point outside the screen,
The change in correction amount per time axis is large. Therefore, the induced voltage in the output amplification section also increases, so the power supply voltage must be increased, resulting in a problem of increased power consumption.

Furthermore, in order to suppress the induced voltage, the band can be limited using an LPF or the like with a low cut-off frequency.
At this time, there was a problem in that the response of the correction amount within the scanning period also deteriorated, and the correction amount at each adjustment point could not be adjusted independently.

OBJECT OF THE INVENTION The present invention solves the above-mentioned problems of the conventional art, and aims to improve horizontal BL which has a low correlation with changes in the amount of correction in the power amplifying section.
It is an object of the present invention to provide a digital convergence device that suppresses the induced voltage during the K period and consumes less power.

Structure of the Invention The present invention provides a means for digitally storing the correction amount for each adjustment point, a means for reading out the stored correction amount, and a means for reading out the correction amount from the read out correction amount for the adjustment point outside the screen. , is a digital convergence device equipped with means for calculating the correction amount for the retrace period by calculation, and calculates the correction amount for the retrace period from the correction amounts of two off-screen adjustment points, and detects highly correlated correction amount changes. In this way, the power amplification section suppresses the induced voltage induced during the horizontal BLK period in which the amount of correction per time axis changes greatly, thereby making it possible to perform convergence adjustment with low power consumption and high precision.

DESCRIPTION OF EMBODIMENTS FIG. 4 shows a block diagram of a digital convergence device in a first embodiment of the present invention. In FIG. 4, components that perform the same operations as those in FIG. 3 are designated by the same numbers, and their explanations will be omitted.

In FIG. 4, 19 is a BLK period correction amount calculation processing section. The BLK period correction amount calculation processing unit 19 calculates and obtains the correction amount from the adjustment points outside the screen read from the one-frame memory 10.

In order to explain the operation of the digital convergence device of this embodiment configured as described above in detail below, the block diagram showing the configuration of the BLK period correction amount calculation processing section 19 in FIG. 6 and the waveform diagram in FIG. Use. Further, in this embodiment, a case will be described in which, for example, average value approximation is used as the BLK period correction amount calculation processing means.

As shown in Figure 6a, when the adjustment points in the horizontal direction are composed of 7 adjustment points inside the screen, 2 adjustment points outside the screen, and the BLK period, adjustment points A to I and outside the screen. Correction amounts corresponding to R from (1) are written into the one-frame memory 10.

The correction amounts corresponding to the adjustment points A to I and F to R are sequentially read from the 1-frame memory 1°, and
．． The correction amount of B2 is determined by average value approximation from the correction amounts of the left and right adjustment points I and J in the BLK period. The BLK period correction amount calculation processing section 19 is composed of a register 2o, an addition circuit 21, and a gain control circuit 22. Read out the correction amount of off-screen adjustment points I and J in 1 frame memory 1Q and register 20
After setting the 1 frame memory 1Q in the adder circuit 21,
The BLK period obtained as described above is obtained by adding the correction amount (A) of the adjustment point and the correction amount (B) of the adjustment point read from , and halving the gain in the gain control circuit 22. The correction amount is written into the one frame memory 10 via the data multiplexer 28. In the same way, the correction amounts for other BLK periods are calculated and written into the 1-frame memory 1°. By performing the BLK period correction amount calculation processing means as described above, the correction waveform from the adjustment point A shown in FIG.
A correction waveform as shown in Figure C is created. Therefore, the induced voltage vp induced in the output amplifying section 1d has a retrace period of t.
If H is the inductance of the convergence yoke, Ly is the inductance of the convergence yoke.

ipp is a correction current.

Also, when the flyback period is very short, vp naturally becomes very large. Therefore, when the correction waveform shown in FIG.
A large induced voltage is generated as shown in Figure d, but as shown in Figure 6C
When the correction waveform is used, a small induced voltage is generated as shown in FIG. 6e. Next, the output signal is converted into an analog quantity by a D/A converter 14. Then smoothed through LPFl 5,
A correction current as shown in FIG. 6e is applied to the output increaser 16 and is supplied to the convergence coil 17 to perform convergence adjustment.

As described above, according to this embodiment, by using the BLK period period correction calculation processing unit which calculates the correction amount of the BLK period from the correction amount of the adjustment points outside the screen on the left and right sides of the BLK period by means of average value approximation, the correction waveform is The correction amount changes are highly correlated, and the power amplification section suppresses the induced voltage induced during the horizontal BLK period where the correction amount changes greatly on the time axis, making it possible to perform highly accurate convergence adjustment with low power consumption. .

In the first embodiment, the BLK period correction amount calculation processing section performs calculations based on average value approximation, but it goes without saying that calculations using arbitrary coefficients may be used.

Effects of the Invention The present invention provides a means for digitally storing a convergence correction amount for each adjustment point, a means for reading out the stored correction amount, and a return method from the read-out correction amount of the adjustment point outside the screen. By providing a means for calculating the line period correction, the correction amount changes with a high correlation, and the horizontal direction BI where the correction amount changes per time axis in the power amplification section is large;
By suppressing the induced voltage during the period, power consumption can be reduced, and since the correction amount changes are highly correlated, it is easy to design a low-pass filter. Therefore, since the response of the correction amount within the scanning period can be made faster, convergence adjustment can be performed with high precision at each adjustment point, which has a great practical effect.

[Brief explanation of drawings]

Figure 1 is a configuration diagram showing the principle of a projection type color TV receiver.
Figure 2 is a diagram to explain the convergence shift.
FIG. 3 is a block diagram of a conventional digital convergence device, FIG. 4 is a block diagram of a digital convergence device in an embodiment of the present invention, FIG. 5 is a block diagram of a blanking period correction amount calculation processing section, and FIG. FIG. 2 is a waveform chart for explaining the present invention in detail. 5... Read address control section, 8...
・Write address control unit, 9...-Multiplexer, 1Q...1 frame memory, 11...
. . . Data reversible counter, 12 . . . Control channel, 13 . . . Vertical direction interpolation processing unit, 1
8...Register, 14...D/A converter, 15...LPF, 19...BLK
Period correction amount calculation processing unit.

Claims (2)

[Claims] (1) Display means for generating and displaying a plurality of convergence adjustment points in the horizontal and vertical directions on the screen of a color television receiver, input means for inputting position information of the adjustment points, and convergence correction for the adjustment points. A storage means for digitally storing the amount of correction, a reading means for reading out the correction amount stored in the storage means, and a correction amount for the retrace period from the correction amount of the adjustment point outside the screen read from the reading means. A digital convergence device characterized by comprising: means for calculating by calculation. (2) The digital convergence device according to claim 1, wherein the calculation means performs average value calculation.