JPS60140386A - Method and apparatus for correcting deflection strain - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method and apparatus for correcting horizontal and vertical deflection distortions in a CRT display device.

1. Prior Art - Monitoring images displayed on a CRT display device,
Alternatively, when photographing with a camera, high precision may be required for the 1115 fidelity of the geometric shape of the displayed image.

In order to meet this requirement, it is necessary to minimize the horizontal and vertical deflection distortion of the CRT display device, but the deflection distortion correction means of conventional CRT display devices can ensure high accuracy over the entire screen. Even if high accuracy could be achieved, it would not be suitable for seating, and there was a problem that distortion would increase due to aging.

1. Object of the Invention 1. The present invention provides a method and apparatus that can be applied to both electrostatic deflection method and electromagnetic deflection method, and that can correct distortions in wood f and vertical deflection with high precision, reliably, and easily. The purpose is to

Structure of the Invention and Its Effects The present invention is characterized by a correction method for correcting the deflection distortion of a CRT display device by detecting the amount of spatial distortion as a luminance signal and calibrating the deflection distortion.

The present invention also provides a display screen of a CRT display device,
means for generating display image signals for calibration; horizontal and vertical deflection signal means; means for generating horizontal and vertical deflection correction signals; and horizontal and vertical deflection signals generated by the horizontal and vertical deflection signal generating means. means for adding the correction signals generated by the correction signal generation means for the horizontal and vertical deflection signals, spatial transmittance for calibrating the position t: of the calibration signal on the display screen of the CRT display device; A means for changing the reflectance, a means for detecting the luminance through the means for spatially changing the transmittance and reflectance, and a means for monitoring the operation of all the means and applying a calibration signal to a desired position. controlling the operation of the correction signal generating means so as to display the correction signal, calculating the correction amount of the deflection signal with respect to the coordinates of the display surface based on this result, and deflecting the front/back image based on alEMk with respect to the calculated coordinates. An apparatus comprising means for controlling a supplementary iE function, further comprising:
current detection means for detecting a deflection current of an electromagnetic deflection CRT;
The apparatus is characterized by comprising a comparing means for comparing the signal detected by the current detecting means and a deflection signal input, and controlling the value of the deflection current to a desired value by balancing the two input signals of the comparing means. do.

The deflection distortion correction method of the present invention has two operating modes: a calibration mode and a display mode. Calibration mode measures the amount of correction to the deflection voltage or current as a function of the coordinates of the display screen; Display mode automatically corrects the deflection voltage or current when displaying the desired image. Add. A method that can relatively easily obtain the necessary precision through two operating modes is to digitally transmit the signals passing through several circuits involved in deflection, and to digitally control the operation of each circuit using a microprocessor or the like. The following explanation assumes digital control. - Hereinafter, embodiments will be described in detail using drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. In FIG. 1, 1 is a control device, 2 is a deflection signal generator, 3 and 3' are adders, 4 is a CRT display device, 5 is a calibration signal generator, and 6 is a switch.

7 is a mask for deflection measurement, 8 is a brightness detector, and 9 is a correction signal generator. First, in the case of electrostatic deflection, the operation in the calibration mode will be explained. The control device 1 has a function of controlling the operation of the present invention, and its main components are a microprocessor and a memory circuit.

Details of the operation of the control device consisting of a microprocessor and memory can be easily understood from the analogy with the operation of a microcomputer, so a detailed explanation thereof will be omitted. Here, only a description of the control device 1 will be explained.

Deflection signal generator 2 generates horizontal and vertical deflection signals. Each of these horizontal and vertical deflection signals generates a sawtooth voltage in binary ? This is a 4-go pattern. Here, let M be the number of pins for 1, 1 and 2 brigadiers. The internal structure of the deflection signal generator 2 will be explained in detail later. Taking horizontal deflection as an example, it is assumed that the beam is deflected to the left end of the CRT display screen when all of the two 1M bits are O's, and is deflected to the right end when they are all 1's.

If M=8, the beam position (horizontal coordinate) is 2
This means that it can be controlled in 56 steps.

The horizontal and vertical deflection signals sent out from the deflection signal generator 2 pass through adders 3 and 3', respectively, and are applied to the horizontal deflection terminal 41 and the vertical deflection terminal 41 of the CRT display device 4.
′ is added. It is assumed that the CRT display device 4 includes a D/A converter that converts horizontal and vertical deflection input signals into analog deflection voltages.

The horizontal and vertical deflection signals generated by the deflection signal generator 2 are also sent to the control device l. As a result, the control device 1 allows the CRT electron beam to reach the CART tube surface 1-
You can know the position jig (coordinates). The control device 1 drives the calibration signal generator 5 based on the beam coordinates thus obtained. The calibration signal generator 5 is C
A calibration beam is generated that produces a spot-like pattern with a predetermined brightness in a predetermined small area of the display surface of the RT display device 4. The signal for this calibration is.

The CRT display device 1.
The brightness signal of No. 4 is input manually to one terminal 42.

A deflection measurement mask 7 is attached closely to the display surface of the CRT display device 4. Figure 2 shows the mask 7 for deflection measurement.
jlζ is an example of how it looks from the +iij plane. The deflection measurement mask 7 is a transpermeable mask having several predetermined transmittances as indicated by hatching in FIG. Figure 3 shows an example of the transmission (of one distribution) of a part of the trans-par range indicated by diagonal lines in Fig. 2.As shown in Fig. 3(a), The center of is set as the origin O, and a rectangular coordinate system (X ty) passing through 0 is determined.The transmittance of a part of the trans-par range is within a predetermined range (-X < x < X and -
y<y<y), for example, as shown in Fig. 3(b), and if the position of the calibration signal of the brightness is without positional distortion, then the position of the calibration signal of the brightness is at the origin of the part of the transformer range. Please make sure to do so. At this time, if there is deflection distortion, the calibration signal deviates from the origin of the transformer range. The brightness detector 8 detects the brightness of the calibration signal transmitted through the deflection measurement mask 7. The brightness detector 8 is composed of a suitable photoelectric conversion element, and its field of view is adjusted so as to cover the front surface of the display surface of the CRT display device 4.
The output signal is manually input to the control device 1. In this state, the correction signal generator 9 generates correction signals for horizontal and vertical deflection, and the adders Ia 3 and 3' send the correction signals to the deflection signal 1) generator 2.
The correction signals for the drinking water deflection of the water f and l supplied by the water f and l are respectively added. As a result, the position of the iE signal displayed on the CRT display device 4 moves. That is, when the magnitude of the correction signal is changed under the control of the control device 1, the coordinates of the signal for 1 degree +1 degree change. Along with this, the light intensity transmitted through the deflection measurement mask 7 changes. The magnitude of the supplementary IL signal is changed so that the peak value of the output of the brightness detector 8 becomes minimum or maximum. In addition,
The brightness of the calibration signal (spot) decays exponentially after the electron beam stimulating the phosphor disappears. The values of the horizontal and vertical correction signals when the peak value of the luminance reaches the minimum value or the maximum value are stored in the control device 1 together with the coordinates of the calibration signal.

The operations described above are performed for all the shaded areas shown in FIG. 2, and the amount of correction of the deflection signal with respect to the center coordinates of each shaded area is memorized. If you want to perform more precise correction, use multiple deflection measurement masks with different transmittance distributions as shown in Figure 3. By replacing it with a mask, adjusting the position of F1 with the necessary accuracy becomes Ijffl.C
The tendency of change in the amount of correction with respect to the coordinates on the RT display screen is actually relatively monotonous. Therefore, the number of hatched areas shown in FIG. 2 does not need to be so large. Also, from the data of the supplementary IF recovered in this way,
The function of the control device 1 allows the control device 1 to easily determine the coordinates of each pixel on the display screen of T, in other words, the amount of correction for the pattern of the deflection signal, by interpolation.

Here, the water and vertical deflection signals generated by the deflection signal generator 2 and the correction signal generator 9 and their correction signals will be further explained. FIG. 4 is a block diagram showing an example of the internal configuration of the deflection signal generator 2. As shown in FIG. In the figure, 21 is a clock generator, 22 and 22'
is a binary counter, and 23 is a frequency divider circuit.

The output of the clock generator 21 is supplied to an M+1 stage binary counter 22 and a frequency divider circuit 23. When the scanning method of the CRT display device is the NTSG method, the frequency division ratio of the frequency dividing circuit 23 is 525 (= 3X5X5X7)
The output of the 0 frequency divider circuit 23 is supplied to the M'-stage binary counter 22' (M and M' may be the same or different as required). The contents of the north M stage of the M+1 stage binary counter 22 are outputted from the output terminal 24 as an M-bit pattern.

The frequency of the clock generated by the clock generator 21 is selected so that one cycle of this pattern change is equal to one horizontal scanning period. Further, the contents of the M'-stage binary counter are outputted as an M'-bit pattern from the output terminal 24'.

The signals output from the output terminals 24 and 24' (which are actually terminals for outputting parallel M or M' bit signals) become horizontal and vertical deflection signals, respectively. If these signals are converted into 11-binary codes and D/A converted, a sawtooth deflection voltage waveform can be obtained. Note that the signal sent from the M'-stage binary counter 22' to the M+1-stage binary counter 22 is a reset signal for matching the phases of the horizontal deflection start point and the frame start point.

FIG. 5 is a block diagram showing an example of the internal configuration of the correction signal generator 9. As shown in FIG. In the figure, 81 and 91' are N-bit 0f inverse counters for generating water/vibration and vertical deflection correction signals, respectively. ii Ding reverse count 9
1 and 91' advance or reverse the counting contents according to signals inputted from the control device 1 to the corresponding input terminals 92 and 32', respectively. The counted contents are output as an N-bit pattern to adders 3 and 3' via corresponding output terminals 93 and 83', and further controlled!
It is also sent to one device.

FIG. 6 is a diagram for explaining the operation of adders 3 and 3'. As an example, assume that the number of bits N of the complementary i[signal is N=4. The adder 3 adds, for example, the lower two bits of the horizontal deflection signal to the l-2 bits of the Mokou correction signal in correspondence. Therefore, the output signal of the adder 3 consists of a pattern of M+2 bits, and in this way, the accuracy of the deflection voltage becomes 3A. At this time, the correction of deflection distortion; The corresponding range is the number of bits (-
In the first series of examples, the selection of 2) is determined by the equipment design conditions. Note that the operation of the adder 3' is as follows:
Since it is the same as , the description is omitted.

Next, the case of electromagnetic deflection will be explained. In the case of electrostatic deflection, the deflection angle of the electron beam is determined by the deflection voltage applied to the deflection electrodes of the CRT. °CRT in case of electromagnetic deflection
The deflection angle is determined by the current flowing through the deflection coil located outside of the deflection coil. Therefore, when using an electromagnetic deflection type CRT, it is necessary to accurately correct the deflection current.

A control method for this purpose will be explained below.

FIG. 7 shows the deflection "upstream 1" when using an electromagnetic deflection CRT.
In Figure 0, which is a block diagram showing an example of the u control, only the portion related to the deflection of the water 11 is shown, and 43 is the D/
A converter, 44 is a differential amplifier, 45 is a current drive circuit, 4
6 is a deflection coil, and 47 is a deflection current detection resistor.

The output of adder 3 is input to input terminal r41. The signal is applied to a differential amplifier 44 via a D/A converter 43. The output of the differential amplifier 44 is applied to a current drive circuit 45, and the current drive circuit 45 supplies a deflection current id to the horizontal deflection coil 4B. id
(l/j is detected by the voltage drop d of the resistor 47 connected in series with the deflection coil 46, and ld is fed back to the differential amplifier 44. With such a configuration of the feedback control system.

11 to the deviation increase '-8f voltage applied to the input terminal 41.
The proportional deflection current id can be ft), and therefore, to compensate for the deflection current id, one can apply exactly the same method as described above for the case of electrostatic deflection. . Note that the vertical deflection is the same as the tree f deflection, so a description thereof will be omitted.

Finally, I will explain the display mode. In FIG. 1, the contacts of the switch 6 are connected to the 62 side. The image data to be displayed is input from the input terminal IO, and when the image data is read from a frame memory that stores one screen worth of image data, for example, the read address of the frame memory is specified by the tree+i and the toncho deflection. This can be easily performed on the frame memory side based on the clock signal outputted via the output terminal 25. Also,
In the display mode, the control device 1 can generate a correction signal corresponding to the coordinates of the deflection signal by using the correspondence between the deflection signal CId in the calibration mode and the correction jE signal. Furthermore, by monitoring the CR7 display screen from the location where the brightness detector 8 obtained in the calibration mode is installed, it is possible to monitor images free of deflection distortion.
When photographing a display image, a camera may be installed here.

An embodiment of the deflection distortion correction method has been described in detail, but many variations based on the principle described in ``UF'' are possible. For example, the density pattern of the deflection measurement mask 7 may have many shapes different from those shown in FIGS. 2 and 3, and instead of the deflection measurement mask 7 shown in FIG.
A correction signal may be obtained by measuring the brightness of the reflected light with the brightness detector 8 using a mirror (deflection measuring mirror) with a spatially holey reflectance distribution as shown in FIG. An example of this is shown in FIG. 10. In FIGS. 8, 9, and 10, the same parts and numbers as in other figures indicate the same members,
7' is a deflection measuring mirror. By using the deflection measuring mirror 7' instead of the deflection measuring mask 7, the CRT
Test i1: without putting a mask etc. in close contact with the tube surface.

This makes it easy to measure brightness when Hereinafter, in the explanation of the block diagrams shown in each figure, it is assumed that all the signals are digital signals, but some or all of these signals may be analog signals.

The key point of the present invention is to use data regarding the correction ψ of deflection distortion measured in the calibration mode to automatically generate a correction signal in the table jJ< mode and to correct the deflection distortion ′. It is a matter of choosing whether to use analog, digital, or digital signals for realizing spiritual operations.

-Effects- As explained above, the present invention has 1. Since it is possible to display images with linearity of X'6 accuracy, it can be used not only for initial adjustment at the manufacturing stage of display devices, but also for the purpose of compensating for the effects of ambient temperature or aging. However, it is not widely applicable and has great effects in practical use.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the deflection distortion compensation ILE method of the present invention, FIG. 2 is an explanatory diagram of the arrangement of a density pattern with a mask 7 for deflection measurement, and FIG.
Fig. 4 is a block diagram of an example of the internal configuration of the deflection signal generator 2, and Fig. 5 is a correction signal generator. 9 is a block diagram of one embodiment of the internal configuration of 9, FIG. 6 is a diagram explaining the operation of the adders 3 and 3', 7th is a block diagram of two examples of deflection current control for an electromagnetic deflection CRT, Figure 8 is a front view of the deflection measurement mirror, and Figure 9 is the deflection measurement mirror.
FIG. 1O, which is an explanatory diagram of the spatial change in reflectance, is a block diagram for detecting a correction signal using a deflection measuring mirror. ■...Control device, 2...Deflection signal, 3
．． 3'... Generator, 6... Switch. 4...CRT display device, 5...
- Calibration 1r: Signal generator, 7...Mask for deflection measurement. 8... Brightness detector, 9... Correction signal generator, 24, 24', 25.41.41', 42.81.
62°82, 92', 83. ! 33'...
Signal-input/output terminal, 21...Clock generator, 22, 22'...Binary φ counter, 2
3... Frequency divider circuit, 91, 91'...11 reverse counter, 43
...D/A converter, 44...Differential amplifier, 45...Pass current drive circuit, 46...Deflection coil, 47... ...Resistance permit for deflection itt current galvanometer Applicant: Konishi Roku Photo Industry Co., Ltd. Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 σ Figure 8 Figure 9 (a) (b) Figure 10 424141' to 1

Claims (1)

[Claims] 1) Add the signal of the display image for deflection distortion calibration as the brightness signal of the CRT display device, and calculate the horizontal and vertical directions of the display image for calibration with respect to the screen coordinates corresponding to the horizontal and vertical deflection signals. A deflection distortion compensation method, characterized in that the spatial deflection distortion is compensated by detecting the deflection distortion star as the amount of change in brightness of the displayed image, and performing feedback correction of the water 1L-vertical deflection signal from this amount of change. IF method. 2) means for generating a display image signal for calibration on the display screen of a CRT display device, means for generating horizontal and vertical deflection signals, means for generating correction signals for horizontal and vertical deflection;
means for adding correction signals generated by the correction signal generation means for the horizontal and vertical deflection signals to the horizontal and one-direction deflection signals generated by the horizontal and vertical deflection signal generation means, respectively; A means for spatially changing the transmittance and reflectance to calibrate the position of the calibration signal on the display screen, and detecting the luminance through the means for spatially changing the transmittance and reflectance. means for monitoring the operations of all the means, controlling the operation of the correction signal generating means so as to display the calibration signal at a desired position, and based on this result, deflecting the coordinates of the display surface. A deflection distortion correction IE device comprising means for calculating a correction amount of a signal and controlling the deflection correction amount based on a correction ψ regarding coordinates calculated for a display image. 3) The apparatus according to claim 2, comprising current detection means for detecting a deflection current of an electromagnetic deflection CRT, and comparison means for comparing a signal detected by the current detection means with a deflection signal input, A deflection distortion correction device for an electromagnetic deflection CRT, characterized in that the value of the deflection current is controlled to a required value by balancing the two input signals of the comparison means.