JPS63238789A - Convergence device - Google Patents

Abstract

PURPOSE:To automatically execute the static convergence correction in the condition to display an image by detecting the position dislocation of a pattern signal for detection and controlling a convergence circuit with the detecting signal. CONSTITUTION:A pattern signal necessary to detect a convergence dislocation generated from a pattern generating circuit 35 and a signal from a video signal processing circuit are added 38 and supplied through a video amplifying circuit 37 to the cathode of a CRT. On the other hand, position data from position detecting devices 30 and 31 provided at a screen peripheral part in order to detect the convergence dislocation are stored 32 and compared 33 with reference data. By the comparing output signal, a convergence correcting circuit 34 to execute the static convergence correction is controlled and the output of the circuit 34 is inputted to a convergence yoke 22 of the CRT.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a convergence device that automatically adjusts the convergence that statically changes depending on temperature etc. after the gnamic convergence adjustment when adjusting the convergence of a color television receiver. This invention relates to a pattern signal image output method.

Conventional technology In general, in a projection type color receiver that uses three projection tubes that emit three primary colors to project enlarged images onto a screen, the angle of incidence of the projection tubes on the screen is different for each projection tube, which causes color shift on the screen. arise. The superposition of these three primary colors, so-called convergence, uses a method in which a convergence correction waveform is created in an analog manner in synchronization with the horizontal and vertical scanning cycles, and the size and shape of this waveform are changed and adjusted. There is good luck in terms of convergence accuracy. Therefore, as a method with high convergence accuracy, for example, the method of Japanese Patent Publication No. 59-8114 and the method of Japanese Patent Application Laid-Open No. 65-61652, which is a digital convergence device that can shorten adjustment time, simplify work, and perform automatic adjustment, have been proposed. ing.

A first method of the conventional convergence device will be described below. Fig. 7 shows a configuration diagram of a conventional digital convergence device, in which a grid pattern (shown in Fig. 8) for convergence correction is projected on the screen, and convergence correction is performed for each adjustment point. This method digitally writes data in one frame into a memory, reads out the data, performs D/A conversion, and performs convergence correction.

First, as shown in FIG. 8, a grid pattern projection circuit of, for example, 9 rows in the horizontal direction and 7 columns in the vertical direction is projected on the screen. A horizontal force direction signal 14 of this pattern signal is created by supplying it to a horizontal synchronizing signal 2 synchronized with the scanning of the screen, a horizontal address counter circuit 3 composed of a PLL circuit and a frequency dividing circuit. Further, a vertical force direction signal 15 is generated by a vertical address counter circuit 6 which is reset by a vertical synchronizing signal 4, and is supplied to a pattern projection circuit 1 and displayed. Next, using the cursor keys (not shown) on the control panel 8, select the grid point of the location to be corrected and the color to be corrected, for example, red. The address of the lattice point C selected with the cursor key (referred to as adjustment point) is stored in the write address generation circuit 7, and is supplied to the frame memory 11 via the frame memory control circuit 10i, and the correction data of the adjustment point specified with the cursor key is stored in the write address generation circuit 7. Data read from the frame memory 11 is written to the reversible counter 9. Roughly operate a write key (not shown) on the control panel 8 to increase or decrease the data reversible counter 9 and write corrections to the frame memory 11. Next, a description will be given of how the convergence correction data written in the frame memory 11 is outputted from a-+. 5 Horizontal and vertical addresses corresponding to the adjustment points of the screen are created by a horizontal address counter circuit 3 which receives a horizontal synchronizing signal 2 synchronized with the scanning of the screen and a vertical address counter circuit 6 which receives a vertical synchronizing signal 4 as an input, The data is supplied to the read address generation circuit 6, and the correction data of each adjustment point is read out in addition to the frame memory 11 via the frame memory control circuit 1of:. Since the frame memory 11 stores only correction data for locations corresponding to each adjustment point, the vertical interpolation circuit 12 performs all interpolation between adjustment points in the vertical direction. The vertical interpolation circuit 12 is composed of a subtraction circuit, a coefficient ROM, a multiplication circuit, an addition circuit, etc., and its operation is such that, for example, the subtraction circuit calculates the difference from the correction data of the adjustment points of the second row 1e and the third row 1702 points. The weighting coefficient for each scanning line written in advance in the coefficient ROM is multiplied by a multiplication circuit, and the result is added to the correction data 17 in the second row by an addition circuit to perform interpolation.

The output of the vertical interpolation circuit 12 operating as described above is
A stepwise waveform signal is obtained by converting the signal into an analog quantity in a program conversion circuit 13.

The signal between the adjustment points in the horizontal direction is smoothed by a low-pass filter (not shown) according to the correction amount of the adjustment point in each row, and after being amplified, is supplied to the convergence yoke.

As mentioned above, in the conventional method, for each adjustment point,
Since it can be corrected independently, precision engineering (convergence correction) can be performed.

Next, the second conventional method will be explained using FIG. 9.

In FIG. 9, 18 is a CRT (called a projection tube), 19
is the projection lens, 2o is the screen, 21c is the deflection yaw
22 f”j is the convergence yoke.23
The video signal arriving at the video signal input terminal is amplified to a required amplitude by the video circuit 24, and the projection tube 181r is driven. The video circuit 24 operates in the same way as a normal receiver, but during convergence adjustment, a convergence adjustment pattern signal such as a lattice pattern created by a digital convergence circuit 25 is supplied and displayed. This convergence circuit 25 is the same as that explained in the conventional method 1, so its explanation will be omitted. The deflection circuit 2 and the deflection yoke 21 scan the electron beam of the projection tube 18 using the incoming synchronization signal 26.

Although FIG. 9 shows only one projection tube 18, three projection tubes, red, green, and blue, are normally used in a color receiver. The adjustment pattern detector 28 performs all light detection using a camera or the like, detects the convergence adjustment pattern projected on the screen, and supplies the detected convergence adjustment pattern to the adjustment point detection circuit 29.

The adjustment point detection circuit 29 detects all convergence deviations at each adjustment point, changes the correction amount of the digital convergence circuit 26 based on the signal of the convergence deviation, and automatically performs convergence adjustment. Furthermore, as a method of automatic adjustment, there is a method of correcting the convergence shift using a screen equipped with a photodetector, but the explanation thereof will be omitted.

Problems to be Solved by the Invention However, although the convergence device configured as described above can perform convergence adjustment with high accuracy, static convergence deviation may occur after the power is turned on or due to the ambient temperature of the display device, etc. occur. This static deviation is due to the neck charge of the projection tube.
Gun center drift, etc., DC drift of the convergence output circuit, and deformation of the convergence yoke due to heat.

This is a combination of changes in deflection and focus systems. Therefore, when adjusting convergence with high precision using the conventional method, it is necessary to perform the adjustment after sufficiently heat-running the display device. In general, there is a problem in that static deviations that occur after power is turned on or due to temperature rise require a function such as static centering to be adjusted each time. In addition, in order to project the detection pattern signal only on the periphery of the screen,
This method requires a special blanking signal, and also has the problem that the detection conditions change each time the luminance, brightness, etc. of the display device changes.

In view of the above, the present invention easily displays a detection pattern signal under certain conditions, detects static color misalignment, and automatically performs static convergence correction while the image is displayed. The purpose is to provide a convergence device.

Means for Solving the Problems The present invention provides position detection means for detecting all positional deviations using photoelectric conversion elements provided at the periphery of the screen, and pattern generation means for generating pattern signals to be received by the position detection means. a video signal processing means for processing the video signal; an addition means for adding the signal from the video signal processing circuit and the pattern signal from the pattern generation means; On the left, a video amplification circuit that supplies a video amplification circuit to the left side, a storage unit that stores position data from the position detection unit, a comparison unit that compares the position data from the storage unit, and a convergence unit that controls the deconvergence correction unit using the output from the comparison unit. It is a device.

Effect of the present invention With the above-described configuration, when a static convergence shift occurs due to temperature etc. after all convergence adjustment is completed, the detection pattern signal is added to the video signal after signal processing to detect the peripheral area of the screen. It will be displayed in the section. By accurately detecting all positional deviations of this pattern signal using photoelectric conversion elements installed at the periphery of the screen, and controlling the convergence circuit with the detection signal, it is possible to easily display a pattern signal under certain conditions, and also to display the pattern signal on the screen. Static convergence correction can be performed automatically while the image is being projected.

Embodiment FIG. 1 shows a block diagram of a convergence device in a first embodiment of the present invention. In Figure 1,
36 is a pattern generation circuit that generates a pattern signal necessary for detecting a convergence shift, 36 is a video signal processing circuit that processes a video signal, and 38 is a signal of the number of video signal processing circuits and a pattern from the pattern generation circuit. An adder that adds signals; 37 is a video amplification circuit that amplifies the signal from the adder and supplies it to the cathode of the CRT; 30.3
1 is a position detector provided at the periphery of the screen to detect convergence deviation; 32 is a storage circuit that stores position data from the position detection circuits 30 and 31; and 33 is a storage circuit 3.
A comparison circuit 34 compares the position data from the comparison circuit 33, and a convergence correction circuit 34 performs eristatic convergence correction on the output signal from the comparison circuit 33. In the figure, components that operate in the same manner as in the prior art are designated by the same numbers and explanations will be omitted.

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

Convergence adjustment for the entire screen is performed by the digital convergence circuit 26 or analog convergence circuit as in the past, and after the adjustment is completed, the pattern generation circuit 36 displays pattern signals of each color passing through the position detector 30.31'i. . The projection of the pattern signal is
Amplitude control and black level control from the video signal processing circuit 36,
The video signal subjected to the blanking process is added to the pattern signal from the pattern generation circuit 35 by the adder 38, and the added output is amplified by the video amplification circuit 37 and supplied to the cathode of the CRT. A pattern signal is projected on the FIG. 2 shows the pattern signal 39 passing through the position detector 30.31'i. Immediately after the convergence adjustment is completed, there is no color shift and the same position is scanned. At this time, the position detectors 30 and 31 are performing position detection. The position data from the position detectors 30, 31 is stored in a storage circuit 34. The output signal from the storage circuit 34 is supplied to a comparison circuit 36 and is compared with a position signal, such as a green pattern signal, which serves as reference data. The output from the comparison circuit 36 is supplied to the convergence correction circuit 36 to control the static deviation amount so that the position is the same as that of the green pattern signal serving as the reference data.

Next, in order to explain in detail the operation of the method of displaying the pattern signal displayed at the periphery of the screen, the block diagram in Fig. 3 and the block diagram in Fig.
Use the operation diagram shown in the figure. The video signal shown in FIG. 4(b) is input to the video signal input terminal 23 in FIG. The signal is supplied to the configured video signal processing circuit 38. The amplitude control circuit 4o performs contrast control by controlling the amplitude of the video signal. A black level control circuit 41 controls the black level of the video signal to perform brightness control. The blanking processing circuit 42 blanks periods other than the valid display period. Therefore, from the video signal processing circuit 36,
The video signal shown in FIG. 4(b) is subjected to amplitude and black level control, and the signal blanking period t is shown in FIG. 4(C).
A video signal (FIG. 4(d)) blanked with a blanking pulse having BLK is output. Figure 4 (2L
) to drive the F deflection yoke in the deflection circuit 27 to
The deflection current for scanning the electron beam of 18 is shown, and t
R is the retrace period. The fourth signal from the pattern generation circuit 35
The pattern signal shown in FIG. 4(6) is supplied to the adder 38, where it is added to the video signal shown in FIG. 4(d) from the video signal processing circuit 36, and the signal shown in FIG. 4(f) is output. Ru. The video signal on which the pattern signal from the adder 38 is superimposed is amplified by the video amplification circuit 3T and then supplied to the cathode of the CRT 18, so that the pattern signal is displayed on the periphery of the screen together with the video signal. Note that the condition for projecting the pattern signal on the periphery of the screen is that the retrace period tR must be set shorter than the signal blanking period tBLK. (tR
(t BLK) Next, in order to explain the operation when a convergence shift occurs, FIGS. 6 and 6 are operation diagrams. The explanation will be given assuming that the pattern signal after convergence adjustment is shifted upward, for example, in the red pattern signal 43, as shown in FIGS. 2 to 6. An enlarged screen view is shown in FIG. 6 (!L). Note that the color switching of the pattern signal at this time is such that the green pattern signal 39 is generated during the first field scan, and the red pattern signal 43 is generated during the second field scan by the device detector 3o constituted by the pattern generation circuit 36. The red pattern signal 43 is photoelectrically converted, and the photoelectrically converted voltage is shown in FIG. 6(b). This photoelectric conversion voltage is used by the position detector 31 described above to detect the amount of positional deviation as shown in the upper part of FIG. 6(b).

The detection signal from the position detector 31 is stored as position data in a storage circuit 32. The output signal from the memory circuit 32 is supplied to a comparator circuit 33 which compares the position data of the green pattern signal, which serves as reference data, with the position data of the red butter/signal. The direction static convergence correction circuit is supplied with a static convergence correction circuit to move the red pattern signal 43 from A to B on the screen so that it is at the same position as the green pattern signal 39, as shown in FIG. 5(b). By controlling the amount of deviation, static convergence correction can be performed automatically.

Furthermore, convergence adjustment of static deviations in the left-right direction can also be performed using the position detector 3o. Furthermore, since the correction for blue color is performed in the same manner as for red color, the explanation will be omitted.

As described above, according to this embodiment, the pattern signal is added to the video signal after video signal processing and projected on the periphery of the screen, and this pattern signal is sent to the photoelectric converter provided at the periphery of the screen. By accurately detecting positional deviation with the element and controlling the convergence correction circuit with this detection signal,
It is possible to easily display pattern signals under certain conditions, and to perform highly accurate automatic static convergence correction.

Although static convergence correction has been described in this embodiment, a part of dynamic convergence correction may be performed by providing photoelectric conversion elements also in contradictory areas at the periphery of the screen. It goes without saying that a dynamic convergence adjustment instruction may also be given by displaying a display using a lamp or the like to perform a dynamic convergence adjustment after determining whether there is any dynamic deviation.

Further, in this embodiment, the superimposition of the three primary colors, so-called convergence correction, has been described, but it goes without saying that control of screen amplitude, phase, etc. may also be performed.

Further, in this embodiment, a projection type color receiver has been described for ease of understanding, but it goes without saying that the present invention is also effective for a shadow mask type direct view receiver.

As described in detail, according to the present invention, when the convergence, which has been precisely adjusted by the digital and analog force type dynamic convergence circuits, undergoes a static deviation due to temperature, etc., an image is projected on the screen. Static convergence correction can be automatically performed in this state.

In addition, as the pattern signal is projected, the video signal after video signal processing is added to the pattern signal and projected on the periphery of the screen, so there is no need for a special blanking signal, and the pattern signal under certain conditions is can be easily projected, and
Accurate convergence correction with good detection accuracy can be achieved.
Its practical effects are great.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a convergence device in an embodiment of the present invention, FIGS. 2, 3, 4, 6, and 8.
The figure is a diagram for explaining the operation of the same embodiment, Figure 7 is a block diagram of a conventional digital convergence device, Figure 8 is a diagram for explaining the operation of the same circuit, and Figure 9 is a diagram for explaining the operation of the conventional digital convergence device. FIG. 2 is a block diagram of a convergence device that performs two convergence adjustments. 34... Convergence correction circuit, 32...
...Memory circuit, 33...Comparison circuit, 30.3
1...Position detector, 35...Pattern generation circuit, 36...Video signal processing circuit, 38...
...Adder, 37...Video amplification circuit, 2
7...Deflection circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure 2θ iθ Figure 3 Figure 4 Figure 5 2θ

Claims (2)

[Claims] (1) Deflection means for projecting an image on the screen using a deflection current synchronized with a synchronization signal, convergence correction means for correcting color shift on the screen, and photoelectric conversion provided at the periphery of the screen. a position detecting means for detecting positional deviation with an element; a pattern generating means for generating a pattern signal at a position on the screen where the position detecting means can receive; a video signal processing means for processing a video signal; Adding means for adding the signal from the signal processing means and the pattern signal from the pattern generating means; video amplifying means for amplifying the signal from the adding means and supplying it to the cathode of the CRT; and an output from the position detecting means. A convergence device comprising a storage means for storing position data of the storage means, a comparison means for comparing the position data from the storage means, and a control means for controlling the convergence correction means based on an output from the comparison means. (2) Claim 1, characterized in that the pattern generation means sets the deflection retrace period to be shorter than the signal blanking period of the video signal processing means, and generates the pattern signal during the difference period. Convergence device as described.