JPS6110384A - Convergence device - Google Patents

Abstract

PURPOSE:To attain adjustment with high accuracy, ease of adjustment and to reduce power consumption by dividing a dynamic winding of a convergence york into two other windings corresponding to the analog and digital correcting amounts. CONSTITUTION:An output signal of the analog convergence circuit 24 for convergence correction of coarse adjustment and that of the digital convergence circuit 23 for convergence correction of fine adjustment are amplified, the dynamic winding of the convergence yoke is divided into two, the 1st dynamic winding is driven by a digital convergence correction data and the 2nd dynamic winding is driven by the analog convergence correction data.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a device for correcting convergence in a color television receiver, and more particularly to a convergence device that can be adjusted with high precision, is easy to adjust, and consumes little power.

Conventional Structure and Problems In the shadow mask type color picture tube used in general color television receivers, color shift occurs because the radius of curvature of the shadow mask from the center of deflection is larger than the radius of curvature of the shadow mask. In addition, in three projection type color receivers that emit light in three primary colors, the angle of incidence of the picture tube with respect to the screen differs for each picture tube, resulting in color misregistration on the screen. For the superposition of these three primary colors, so-called convergence, an analog method is used to obtain a convergence correction waveform from a horizontal flyback pulse and a vertical waveform using passive elements such as coils, capacitors, and resistors, but the convergence accuracy However, there are some drawbacks that are not very good. As a means for performing highly accurate convergence over the entire screen, for example, as shown in US Pat. No. 3,943,279, a means for digitally performing convergence correction has been proposed.

A conventional digital convergence device for a picture receiver using a picture tube with a delta type electron gun arrangement will be described below. The concept, which will be explained with reference to the block diagram in Figure 1, is that a pattern for convergence correction, such as a grid pattern, is projected on the screen, and data on the amount of convergence correction for each point is digitally recorded in one frame. This information is written into memory, read out, D/A converted, and convergence correction performed. Figure 1 below.

This will be explained in more detail using FIG. First, as shown in FIG. 2a, there are, for example, nine columns in the horizontal direction on the screen.

A dot pattern corresponding to the convergence adjustment points in seven vertical lines is projected from the video signal generation circuit 16, and a dot corresponding to the adjustment point to be corrected is selected using the cursor keys on the control panel 1. The address of the grid point (hereinafter referred to as adjustment point) corresponding to the adjustment point selected with the cursor key is stored in the cursor counter 12. Next, when you specify the color you want to correct, for example red using the write key on the control panel 1, the contents of the one frame memory 3 selected using the cursor key and the write key are read into the data reversible counter 2, and then press the write key. By continuing to operate and increasing/decreasing the data reversible counter 2, write correction is performed. Thereafter, write corrections are made for all adjustment points in the same manner.

Next, reading out the convergence correction amount written in the one-frame memory 3 will be explained. Since the one-frame memory 3 stores only the correction amount at the location corresponding to the adjustment point, it is necessary to perform interpolation for each scanning line between vertical and directional adjustment points. Therefore, for example, read out the correction amount of the adjustment point in the first row from the 1 frame memory 3, and
After filling the register 4, the correction amount of the adjustment point in the second row is read out from the one frame memory 3. In this way, using the correction amounts of the first and second lines read from the one-frame memory 3, the correction amount of the scanning line included between the adjustment points of the first and second lines can be calculated within a linear approximation. Find by insertion.

That is, the difference between the correction amount in the first line and the correction amount in the second line is obtained by a subtraction circuit 5, and multiplied by a weighting coefficient for each scanning line, which is written in advance in the coefficient ROM 7, by a multiplication circuit 6. , the result and the correction data of the second row are added together in an adder circuit 8 to perform interpolation. Next, the output signal of the adder circuit 9 is D/A
The R converter 9 converts it into an analog quantity to obtain a stepped waveform signal. The signal between adjustment points in the horizontal direction is supplied to the convergence yoke 17 after smoothing the correction amount of the adjustment point in each row by a low-pass filter 1o and amplifying it by an output port @21. The same applies to the other green, blue radials, and blue laterals.

However, in the above configuration, since each adjustment point can be corrected independently, convergence correction can be performed with high accuracy;

Blue radial and blue lateral adjustments are required four times, and the entire screen requires 9 x 7 x 4 = 262 adjustments, and to prevent interference from occurring in the convergence yoke of each color, the adjustment for the entire screen was performed several times. Since this method needs to be repeated several times, there is a problem in that it takes a very long adjustment time to accurately perform convergence correction.

As shown in Figure 3, the convergence shift in the shadow mask type color picture tube generally used in color television receivers is caused by the distance from the deflection center to the mask surface 1 even if the beam is concentrated at the center of the screen. is different between the center and the periphery, so the beam is concentrated in front of the shadow mask in the periphery, and the convergence shift increases as it moves away from the center of the screen. The necessary correction waveforms at seven points in the vertical direction passing through the grid point patterns N1 to 81 in FIG. 2(b) are shown by solid lines in FIG. 4(a), and the necessary correction at nine points in the horizontal direction passing through the grid point patterns W1 to El in FIG. The waveform is shown in Figure 4 (b).
As shown by the solid line in Figure 4, both the vertical and horizontal periods are parabolic waveforms as is well known, and when linear approximation is interpolated for each scanning line between adjustment points in the vertical direction, the result is shown by the broken line in Figure 4 (-). Similarly, a convergence shift occurs between each adjustment point in the vertical direction. In addition, regarding the adjustment points in the horizontal direction, if smoothing by LPF is considered to be interpolation of approximately linear approximation, there is a problem that a convergence shift occurs between each adjustment point in the horizontal direction, as shown by the broken line in Figure 4 (b). It had

Further, as a convergence output circuit, an output circuit with frequency characteristics corresponding to the number of adjustment points in the horizontal direction is required, resulting in an extremely wide band output circuit.

Therefore, since the output circuit has a wide band, the voltage induced in the output circuit increases as the change in the amount of correction with respect to the time axis increases. Since the power consumption of the convergence output circuit has to be lowered, the power consumption of the convergence output circuit becomes extremely large.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional problems, and aims to provide a convergence device that can be adjusted with high precision, is easy to adjust, and consumes little power.

Structure of the Invention The present invention provides analog convergence means for performing convergence correction for rough adjustment, digital convergence means for performing fine adjustment, and signals from the two convergence means are outputted to a first output configured with a constant current circuit. a circuit, an output means for amplifying each signal in a second output circuit, and dividing the dynamometer winding of the convergence yoke into a first dynamometer winding and a second dynamometer winding; ) is driven with digital convergence M positive data from the first output circuit,
The second dynamic winding is a convergence device including a drive means driven by Bunalog convergence correction data from the second output circuit, and by dividing the analog correction amount and the digital correction amount by separate windings, The adjustment can be made with high accuracy, the adjustment is easy, and the power consumption can be reduced.

DESCRIPTION OF EMBODIMENTS FIG. 6 shows a block diagram of a convergence device in a first embodiment of the present invention. Components in FIG. 6 that operate in the same way as in FIG. 1 are designated by the same numbers and their explanations will be omitted.

In FIG. 5, 23 is the digital convergence circuit mentioned above, 25 is an output circuit composed of a constant current circuit,
17 is a convergence yoke, for example, a blue radial first dynamic winding, 24 is a horizontal parabolic waveform generating circuit 18, a vertical parabolic waveform generating circuit 19, and 2.
21 is an output circuit composed of a constant current circuit, and 22 is a convergence yoke, for example a blue radial second dynamic winding.

The waveform diagram of FIG. 6 will be used to explain the operation of the convergence device of this embodiment constructed as described above.

Horizontal and vertical periodic pulses synchronized with the deflection current period are added as synchronization signals, which drive the mK digital convergence circuit 23 mentioned above, and also drive the horizontal parabolic waveform generation circuit 18 and the vertical parabolic waveform generation circuit of the analog convergence circuit 24. 19 to create horizontal parabolic and vertical parabolic waveforms. Horizontal parabolic waveform creation circuit 18 and vertical parabolic waveform creation circuit 19
The signals are added by the adder circuit 2o and then supplied to the output circuit 21, and after being amplified, the signals are supplied to the second radial front winding.

Generally, the green and red radial correction waveforms are a correction waveform in which a horizontal parabola waveform and a vertical parabola waveform are superimposed, but the blue radial correction waveform is almost a horizontal parabola waveform. The necessary correction waveform of the blue radial at nine points in the horizontal direction passing through the grid point pattern W1 to El in FIG. 2(b) is a horizontal parabolic waveform as shown in FIG. 6(d). At this time, as a correction waveform for rough adjustment, the analog waveform from the analog convergence circuit 24 is amplified by the output circuit 21, and the blue radial second dynamic winding is driven, as shown in FIG. 6(a). , a horizontal parabolic current with a correction amount x1 flows. Therefore, the convergence is almost the same on the screen.

Next, as a correction waveform for fine adjustment, the correction amount for each adjustment point from Wl to Wl to El is inputted from the control panel 1 of the digital convergence circuit 23, and the D/A 9
A staircase wave shown in FIG. 6(b) is outputted from the step waveform shown in FIG. this(
By passing the waveform of b) through the LPF 1o and amplifying it in the output circuit 25 and driving the blue radial first dynamic winding, the horizontal parahora current of correction amount x2 as shown in FIG. 6(C) is obtained. flows. Therefore, the amount of correction of the necessary correction waveform in FIG. 6(d) is approximately x3! 1+x2, and the convergence correction can be performed at the adjustment point from Wl to Ll in Fig. 2 Φ).

Thereafter, the above operation is similarly performed for all adjustment points.

In the present invention, the correction amount has been described for the blue radial, which requires a correction amount that is about twice or more compared to the correction amount for the green, red radials, and blue laterals, but the present invention also applies to other items. It goes without saying that this idea is valid, but it is clear that it is not.

As described above, according to this embodiment, the analog convergence circuit for creating an analog correction waveform, the digital convergence circuit for creating a digital correction waveform, and the dynamic winding of the convergence yoke are connected to the first dynamic winding and the first dynamic winding. The first dynamic winding is driven by a digital correction waveform, that is, fine adjustment data, which is amplified by an output circuit consisting of a constant current circuit, and the second dynamic winding is driven by an analog waveform. By amplifying and driving the correction waveform, that is, the coarse adjustment data, by an output circuit composed of a constant current circuit, the adjustment time can be shortened and misconvergence between adjustment points can be eliminated. In addition, the amount of digital correction, which is discontinuous correction data, is small and the induced voltage in the output circuit can be reduced, reducing power consumption.
Since the amount of correction per bit can also be reduced, it is possible to eliminate horizontal stripes in the raster caused by discontinuity in the amount of correction in the vertical direction.

A second embodiment of the present invention will be described below with reference to the drawings.

FIG. 7 is a block diagram of a convergence device showing a second embodiment of the present invention, and FIG. 8 is a waveform diagram for explaining the second embodiment. In the figure, 23 is a digital convergence circuit, 24 is an analog convergence circuit, 26.21 is an output circuit configured with a current feedback type, 17 is a blue radial first dynamic winding, and 22 is a blue radial second dynamic winding. This is a dynamic winding, and the structure described above is similar to that shown in FIG. What is different from the configuration shown in FIG. 6 is that the digital correction amounts for the red radial, green radial, and blue lateral from the digital convergence circuit 23 and the analog correction amount from the analog convergence circuit 24 are configured by a constant current circuit. output circuit 26.27.
28 and then the red and green radial and blue lateral dynamic windings are driven.

The operation of the second embodiment of the convergence device configured as described above will be described below.

An analog waveform in which a vertical parabola is superimposed on a horizontal parabola shown in FIG. 8(a) from the analog convergence circuit 24 is supplied to an input terminal θ of an output circuit 26.27.

On the other hand, from the digital comparability circuit 23 as shown in FIG.
) is the red radial digital correction amount shown in output circuit 2.
The correction current shown in FIG. 8C flows through the amplified red radial dynamic winding to perform convergence correction. The same applies to the green radial below. For blue lateral, the analog waveform from the analog convergence circuit 24 is, for example,
A sawtooth waveform is applied to the input terminal Q of the output circuit 28.

The blue lateral digital correction amount from the digital convergence circuit 23 is supplied to the input terminal (2) of the exit circuit 28, and is amplified to drive the blue lateral dynamic winding.

As described above, according to this embodiment, by using the analog correction amount as coarse adjustment data and the digital correction amount as fine adjustment data, adjustment time can be shortened and misconvergence between adjustment points can be eliminated. Furthermore, since the amount of digital correction is small and the amount of correction per bit can be reduced, it is possible to eliminate horizontal stripes in the raster caused by discontinuity in the amount of correction in the vertical direction.

Furthermore, by inputting the analog correction amount with DC cut, the power consumption of the output circuit can be balanced.

9 and 1o are screen diagrams and waveform diagrams showing the concept of extrapolation calculation of the digital convergence device according to the third embodiment of the present invention.

In the extrapolation calculation in the digital convergence device that combines digital convergence and analog convergence according to the present invention, the correction amount is written independently in one frame memory at the extrapolation adjustment point outside the screen.

Generally, extrapolation calculations are performed using the extrapolation point W based on the correction data of the adjustment points W2 and Wl shown in FIG. A method of calculating by linear approximation of (2W1-W2), a method of superimposing the correction data of the difference on the linear approximation data, and a method of using the correction data of Wl as the correction data of the extrapolation point W0 are considered. However, as shown in Figure 10, the convergence shift of the shadow mask type color picture tube is such that the required correction data (solid line) increases as the distance from the center of the screen increases.
Adjustment point W2. Correction data (broken line) (2A2-A1)=A3 obtained by linear approximation of W1 and extrapolation point W0 does not match the necessary correction data A4. Also, A3 obtained by linear approximation
Even if the difference correction data is added to the correction data of A4, it is not possible to obtain a wide frequency characteristic of the output circuit in the large current region. The W2 correction waveform (dotted line) results in a convergence shift. Therefore, adjustment point W2. W1.
Adjustment of W0 must be repeated several times. From the above, the correction method is to increase the correction amount independently as an extrapolation point, and at the same time adjust the correction data from an extrapolation point where the data changes rapidly on the time axis. It is possible to eliminate the influence of response due to deterioration of the frequency characteristics of , and to shorten the adjustment time.

In the embodiment, the waveform for driving the first dynamic winding is digital correction data from the digital convergence circuit 23, but the digital convergence circuit 23 uses analog correction data for local correction that requires a wide band, for example. It may also be used as a circuit.

Although this embodiment has described a picture tube in which the electron gun arrangement is a delta type, it is also applicable to a projection television receiver in which a large screen television is configured using an in-line electron gun arrangement or a plurality of projection picture tubes. It goes without saying that the idea of the present invention is effective even in great aircraft.

Effects of the Invention The convergence device of the present invention comprises an analog convergence means for performing coarse adjustment convergence correction, a digital convergence means for performing fine adjustment convergence correction, and a constant current circuit for the signals from the two comparator means. a first output circuit which has a second output circuit, an output means which amplifies each signal in a second output circuit, and a dynamic winding of the convergence yoke is divided into a first dynamic winding and a second dynamic winding, Drive means for driving the first dynamic winding with digital convergence correction data from the first output circuit, and driving the second dynamic winding with analog convergence correction data from the second output circuit. By providing these, analog quantities can be used as rough adjustment data and digital quantities can be used as fine adjustment data, so adjustment time can be shortened and misconvergence due to linear approximation interpolation between adjustment points can be eliminated. By performing convergence correction on the correction data of the irregular extrapolation points alone, the influence of the frequency characteristics of the output stage is eliminated and adjustment is easy.

In addition, since the discontinuous correction data, that is, the digital correction amount changes less per time axis, and the induced voltage in the output circuit can be reduced, power consumption can be reduced, and the correction amount per bit of digital correction amount can also be reduced. It is possible to eliminate horizontal stripes in the raster due to discontinuity in the amount of correction in the direction, which has a great practical effect.

[Brief explanation of drawings]

Figure 1 is a block diagram of a conventional convergence device, Figure 2 is a block diagram of a conventional convergence device.
The figure is a front view of the screen displaying the pattern, Figure 3 is a front view of the screen showing convergence deviation, Figure 4 is a waveform diagram showing the required amount of convergence and the amount of correction by the conventional example, and Figure 6 is a front view of the screen showing the convergence shift.
The figure is a block diagram of a convergence device in the first embodiment of the present invention, FIG. 6 is a waveform diagram for explaining the first embodiment, 23... digital convergence circuit, 2
4...Analog convergence circuit, 25...
...First output circuit, 21...Second output circuit, 17...First dynamic winding, 22...
...Second dynamic winding. Fig. 2(a) Fig. 3 Fig. 4 Cα) Fig. 6 II', #ImJk411a41-1. gl&J Figure 8 Figure 9 Wataru tnpt Lido 4th place → Beg. 00 ・ @ @・@Neo (!1 @ @
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Claims (2)

[Claims] (1) Analog convergence means that performs coarse convergence correction using passive elements using horizontal and vertical periodic voltages synchronized with a synchronization signal, and a convergence adjustment point that is specified using the cursor key, and the convergence correction data of this adjustment point Digital convergence means writes in a frame memory and reads out from the one frame memory to perform fine adjustment convergence correction, and the signals from the two convergence means are transmitted to a first output circuit composed of a constant current circuit, and a second output circuit configured with a constant current circuit. output means for amplifying each signal in an output circuit; and a dynamic winding of the convergence yoke is divided into a first dynamic winding and a second dynamic winding, and the first dynamic winding includes the first dynamic winding. A convergence device, characterized in that the convergence device is driven by digital convergence correction data from an output circuit, and the second dynamic winding is provided with a drive means for driving by analog convergence correction data from the second output circuit. (2) A convergence device according to claim 1, wherein the digital convergence means is capable of performing convergence correction on an extrapolation point independently without performing extrapolation calculations.