JPH0338797B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a convergence adjustment device for a color television receiver, and provides a digital convergence adjustment device that can be adjusted quickly and accurately.

Prior Art First, we will discuss the convergence deviation of color television receivers by taking a projection type receiver as an example.
This will be explained with figures. In FIG. 1, 1 indicates a projection screen for projecting an image, 2,
Reference numerals 3 and 4 denote projection cathode ray tubes equipped with optical lenses that form images captured on the phosphor screen onto the projection screen, and three-color images of red, green, and blue are obtained on each phosphor screen. These projection cathode ray tubes are the first
When arranged in the horizontal direction as shown in the figure, the projection angles of the projection cathode ray tubes with respect to the projection screen 1 are different, so that the projected raster images are shifted in position for each color. This situation is shown in FIG. In FIG. 2, a solid line 31 is a raster image projected by the green light projection cathode ray tube 3 placed in the center, a dotted line 41 is a raster image projected by the blue light projection cathode ray tube 4 placed on the left side with respect to the screen, and a dashed line 51 shows a raster image projected by a red light projection cathode ray tube 5 placed on the right side of the screen.

In order to correct these positional deviations, a convergence adjustment coil is provided in the projection cathode ray tubes 2, 3, and 4 separately from the main deflection coil, and a current obtained by amplitude modulating a sawtooth wave with a horizontal scanning period with a vertical period is used for these convergence adjustments. This is possible by flowing it through a coil.

However, the amount of convergence shift is not solely determined by the projection angle and projection distance between the screen and the projection CRT, but also by the aberrations and variations in the optical lens system (the mounting position of the projection CRT, the curvature of the projection screen, etc.). Therefore, it is impossible to perform highly accurate convergence adjustment over the entire screen using a combination of normal sawtooth waves and parabolic waves.

As one method for realizing this highly accurate convergence adjustment, a method using a convergence circuit having digital correction waveform formation has been considered. The outline is as follows. First, a plurality of convergence adjustment points are set in a matrix on the screen (for example, about 7 points horizontally and 5 points vertically), and the convergence correction data of the adjustment points is stored in a memory in digital quantities. The data is read out in synchronization with the main deflection, and the analog amount after D/A conversion is amplified in power and applied to the convergence adjustment coil. Convergence adjustment is performed by rewriting digital data stored in memory. As a result, any waveform can be generated, and highly accurate convergence correction including variation correction can be performed.

Next, an example of the configuration will be explained with reference to FIG. In FIG. 3, reference numeral 5 denotes a read address control section which generates an address for a convergence correction signal and an address for a dot signal for convergence adjustment based on a synchronization signal. A dot generator 6 generates a dot signal from the signal of the read address control section. Although not shown, 7 is a video circuit that amplifies the normal video signal and the signal from the dot generator, performs DC reproduction, etc., and drives the video portion of the cathode ray tube. Reference numeral 8 denotes a write address control section that generates position data, that is, an address during convergence adjustment. Numeral 9 is a multiplexer for selecting either read or write address.
10 is a one-frame memory that stores convergence correction data. 11 is a data reversible counter that generates increase/decrease data for convergence correction data. Reference numeral 12 denotes a control panel equipped with an address key for externally selecting the position of an adjustment point during convergence adjustment, and a data key for increasing or decreasing the convergence correction amount. Reference numeral 13 denotes a vertical interpolation processing section that generates a convergence correction signal from data interpolation during scanning at points other than the convergence adjustment point. 14 is a D/A converter, 15 is a low-pass filter, 16 is an output amplification section, and 17 is a convergence adjustment coil. 18 is a register that stores data once.

Note that FIG. 3 shows only one channel, and in addition to this, the configuration of FIG. 1 requires at least three other channels, a total of four channels. This includes horizontal and vertical corrections for the blue projection cathode ray tube and horizontal and vertical corrections for the red projection cathode ray tube.

Next, the operation will be explained. First, when receiving a normal video signal, the video circuit 7 receives the normal video signal. Then, the read address control section 5 generates repeated addresses in synchronization with the synchronization signal. The multiplexer 9 selects the read side, the address of this read side is input to the 1-frame memory 10, data corresponding to that address is output to the register 18, and is sent to the D/A converter through the vertical interpolation processor 13. The signal is converted into an analog quantity at 14, passes through a low-pass filter 15 and an output amplification section 16, and drives a convergence adjustment coil 17. In other words, it operates in the same way as an arbitrary signal generator that reads data from one frame memory, and can generate free waveforms that are not restricted by parabolic waves or sawtooth waves.

Next, during convergence adjustment, the video circuit 7 is connected to the dot signal generator 6, and the screen becomes a dot pattern in which only the convergence adjustment points are illuminated. On the other hand, when a convergence adjustment point is selected using the address key on the control panel 12, the write address control unit 8 converts the data of this adjustment point into an actual address and transmits it to the multiplexer 9. When the data key on the control panel 12 is operated, this data is transmitted to the data reversible counter and the data value is increased or decreased. Then, during the retrace period, the multiplexer 9 is switched to the write address control section 8, and the contents of the one frame memory 10 are rewritten with the data of the data reversible counter 11. Since the read address control unit 5 is enabled during the scanning period, new rewritten data is output and the convergence changes. This series of operations must be performed visually. By visually performing this series of operations, the convergence adjustment at each adjustment point can be performed independently and accurately.

Problems to be Solved by the Invention However, such convergence correction has the problem that it is necessary to visually adjust each dot, which takes a very long time. For example, in the example of adjustment points of 7 vertical points and 9 horizontal points mentioned above, 5×7×
4 = 140 times, and even if each time is 30 seconds, the amount of work will exceed one hour.

Means for Solving the Problems The digital convergence adjustment device of the present invention includes a generating means for generating adjustment patterns corresponding to a plurality of convergence adjustment points in the horizontal and vertical directions of the screen of a color television receiver; a switching means for switching between a signal of the means and a video signal and applying the signal to a video circuit, a cathode ray tube for displaying an image based on an output signal of the video circuit, a convergence correction coil attached to the cathode ray tube, and each of the convergence adjustment points. a storage means for storing digital data of a convergence correction amount for one screen; a readout address control section for controlling a readout address of the storage means in accordance with a synchronization signal; and A/D conversion of the data in the storage means to perform convergence correction. In a digital convergence adjustment device for a color television receiver, which includes a conversion section that converts into a waveform, and an output amplifier that drives the convergence correction coil according to the output of the conversion section, a portion of the screen including the convergence adjustment point is provided. a moving means for physically varying the imaging direction of the enlarged imaging means; a control means for controlling the moving means; and an instruction input means for instructing the control means to position a convergence adjustment point. and a detection means for detecting the amount of deviation at a convergence adjustment point between two colors from the output signal of the enlarged imaging means, and an increase/decrease means for increasing or decreasing the amount of digital data stored in the storage means by the detection means. It has a similar configuration.

Operation According to the above configuration, the convergence adjustment point specified by the instruction input means is enlarged and imaged, the convergence shift between the two colors is detected with high accuracy from the output signal, and the detected amount is stored in one frame memory which is the storage means. By increasing or decreasing the digital data of the convergence correction amount stored in , the convergence deviation between the two colors can be automatically adjusted without relying on human visual observation. Therefore,
Convergence can be adjusted quickly and without any skill.

Embodiment An embodiment of the present invention is shown in FIGS. 4 and 5, and will be described with reference to the drawings. Components with the same functions as those in FIG. 3 are given the same numbers and their explanations will be omitted.

FIG. 4 is a schematic diagram showing a color television receiver combined with a digital convergence adjustment device according to the present invention, and 19 is a projection screen;
20 is a projection cathode ray tube, and 21 is a projection lens. 22 is a deflection yoke, and 23 is a convergence yoke, in which a third convergence coil 17 is provided. 24 is a digital convergence section, and 25 is a deflection circuit that drives the deflection yoke 22.

26 surrounded by a dotted line indicates an imaging section. Imaging unit 2
6 is equipped with a television camera head 27 and a camera head angle moving section 28 capable of directing the camera head 27 to any convergence adjustment point within the screen 19. Position detection section 2
9 detects which position on the screen the camera head 27 is pointing at based on the angle of the camera head 27. The digital storage device 30 controls the camera head angle moving section 28 and stores which adjustment point is currently in place. The position of the convergence adjustment point is selected by an instruction from the input section 31.

Next, the operation will be explained. First, when receiving a normal image, a video signal is applied to the video circuit 7, although not shown. On the other hand, data from one frame memory in the digital convergence unit 24 is read out, and after D/A conversion, the convergence coil 17 in the convergence yoke 22 is driven through the output amplification unit 16 to perform convergence correction. This operation is the same as the conventional one. Note that the imaging unit 26 and the input unit 31 do not operate during normal image reception, and may be left alone.

Next, during convergence adjustment, the dot pattern of the dot generator 6 is input to the video circuit 7.
At this time, convergence correction is performed based on the data in the one-frame memory in the digital convergence unit 24, as in the case of normal image reception.

Here, as will be described in detail later, the input unit 31 instructs the convergence adjustment point, and the digital convergence unit 24 detects the convergence deviation amount based on the output of the television camera head 27.
The digital data of the convergence correction amount is increased or decreased in accordance with the value, and the convergence shift at the designated adjustment point is automatically adjusted.

On the other hand, in the conventional example, as described above, the convergence shift was detected visually and the data increase/decrease was manually instructed using the control panel 12 shown in FIG.

The internal configuration of the digital convergence section 24 is shown in FIG. Note that in FIG. 5, parts that operate in the same way as in FIG. 3 are given the same numbers and their explanations are omitted. FIG. 5 shows, by way of example, a channel for adjusting the horizontal convergence of red and green. Reference numeral 32 denotes a color signal switching unit that switches between the dot generator 6 and a position counter to be described later, depending on the color to be adjusted;
3 is a green horizontal position counter, 35 is a red horizontal position counter, and 34 is a comparator for comparing the values of both horizontal position counters.

Next, the operation is shown in Figure 5 and Figure 6, which is an explanatory diagram of the operation.
This will be explained with reference to figures a, b, and c. Figure 6a shows the convergence adjustment points of 5 points vertically and 7 points horizontally.
2, indicating that point Y4 has been selected. This instruction is given by the input section 31 shown in FIG. 5, and on the other hand is converted into data for actually operating the camera head angle moving section 28 by the digital storage device 30 shown in FIG. 4, so as to direct the camera head 27 in that direction. It turns out. On the other hand, information on convergence adjustment points X2 and Y4 is sent to the write address control section 8 in FIG. Thereby, the detection of the convergence correction amount and the position of data rewriting are made to coincide. The camera head 27 magnifies and images a part of the screen to obtain an image as shown in FIG. 6b.

The reason for enlarging the image is that the obtained dot image becomes wider due to the spread of the electron beam, the blurring of the optical system, etc., and a resolution sufficient to detect the shape of the spread image is required.

First, the color signal switching unit 32 controls the dot generator 6 to generate only a green signal, and at the same time stops the red horizontal counter 35. Then the 6th
Since only the green dot signal shown in FIG. 6B is obtained, the output of the camera head 27 at this time becomes the signal shown in FIG. 6C. This is the waveform of one horizontal period during scanning with a green dot signal. This green horizontal position counter counts an appropriate clock signal of several MHz using the horizontal synchronization signal as a start signal, and this sixth
The dot imaging waveform shown in FIG. c is used as a stop signal, and the value of this counter indicates the horizontal position.

Next, the color signal generating section 32 generates only a red signal, stops the green horizontal position counter, and obtains the horizontal position of the red signal from the value of the red horizontal position counter.
This switching may be performed in vertical cycles. Then, the comparator 34 compares both values, and increases or decreases the value of the data reversible counter 11 depending on the magnitude. As a result, the amount of convergence correction performed based on the data in the one-frame digital memory 10 changes, and the position of the red dot in the horizontal direction moves. The automatic adjustment is completed by repeating the loop of detection, comparison, and data increase/decrease until the horizontal positions of green and red match.

Vertical adjustment is likewise possible with the configuration shown in FIG. However, if the clock counted by the green horizontal position counter 33 and the red horizontal position counter 34 shown in FIG. Position can be detected.

By performing the above operations for the blue and green dots, all convergence adjustments can be made.

Although the above operation has been described using a projection type color television receiver as an example, it can be used in the same manner for a general color television receiver equipped with a direct view type cathode ray tube.

Effects of the Invention According to the convergence adjustment device of the embodiment, by inputting the address of an arbitrary convergence adjustment point where the convergence is out of alignment, the camera head automatically points in the direction of that adjustment point, and furthermore, the convergence adjustment is automatically performed. It is done. Therefore, convergence adjustment for the entire screen can be completed by simply performing an operation corresponding to the address from the input section, and adjustment can be performed in a short time regardless of the skill level of the adjuster.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the principle of a projection type color television receiver, Fig. 2 is an explanatory diagram explaining convergence deviation due to the structure of Fig. 1, and Fig. 3 is a main part structure of a conventional digital convergence adjustment device. 4 is a configuration diagram showing an embodiment of the present invention,
Fig. 5 is a configuration diagram showing the main parts of the present invention, Fig. 6a,
b and c are respectively a front view of the screen, an enlarged view thereof, and a waveform diagram for explaining the operation. 5... Read address control unit, 6... Dot generator, 7... Video circuit, 8... Write address control unit, 9... Multiplexer, 10... 1 frame memory, 11... Data reversible counter, 13... Vertical direction interpolation processing unit, 14...D/A converter, 15...Low pass filter, 16...Output amplification section, 17...Convergence adjustment coil, 18...Register, 27...Camera head, 31...Input section, 32...Color signal switching section,
33... Green horizontal position counter, 34... Comparator, 35
...Red horizontal position counter.

Claims (1)

[Claims] 1. Generating means for generating adjustment patterns corresponding to a plurality of convergence adjustment points in the horizontal and vertical directions of the screen of a color television receiver, and switching between the signal of the generating means and the video signal and applying it to the video circuit. a switching means, a cathode ray tube for displaying an image based on the output signal of the video circuit, a convergence correction coil attached to the cathode ray tube, and a storage means for storing digital data of convergence correction amounts for each of the convergence adjustment points for one screen. a read address control section that controls the read address of the storage means according to a synchronization signal; a conversion section that A/D converts the data of the storage means and converts it into a convergence correction waveform; a digital convergence adjustment device for a color television receiver, comprising: an output amplifier for driving the convergence correction coil; means for enlarging an image of a part of the screen including the convergence adjustment point; a moving means for physically varying a convergence adjustment point; a control means for controlling the moving means; an instruction input means for instructing the control means to position a convergence adjustment point; A digital convergence adjustment device comprising: a detection means for detecting a shift amount at an adjustment point; and an increase/decrease means for increasing or decreasing the amount of digital data stored in the storage means by the detection means.