JPH07115654A - Automatic convergence device - Google Patents

Abstract

PURPOSE:To accurately, stably and automatically adjust convergence regardless of the scanning system of input signals by discriminating the scanning system and fields, correcting the convergence for the respective fields and using the average value of the correction values of two fields as correction data. CONSTITUTION:In a scanning system discrimination part 1 to which deflection synchronizing signals are inputted, whether or not the input signals are of an interlace scanning system or a noninterlace scanning system is discriminated from the phase relation of horizontal synchronizing signals and vertical synchronizing signals and the result is supplied to a control part 4. Also, the deflection synchronizing signals are supplied to a field discrimination part 2 and the parity of the present field is discriminated and sent to the control part 4. The deflection synchronizing signals are inputted to a test signal generation part 3 as well and test signals synchronized with the deflection synchronizing signals are generated at the time of adjustment and sent to a projection part 5. In the projection part 5, the test signals are projected on a phosphor and convergence deviation is detected in a detection part 6 from the light emission timing of the phosphor. The control part 4 controls the projection part 5 so as to eliminate the convergence deviation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for correcting a color television receiver, and more particularly to an automatic convergence correction device for automatically correcting the convergence.

[0002]

2. Description of the Related Art Generally, in a cathode ray tube receiver that displays an image using three electron guns that emit three primary colors (green; hereinafter G, blue; hereinafter B, red; hereinafter R) The electron beam is disturbed by the peripheral magnetic field, causing color shift, focus shift, deflection distortion, and brightness change on the shadow mask. These various corrections produce an analog correction waveform in synchronization with the horizontal and vertical scanning periods, and the size of this waveform,
Although a method of adjusting by changing the shape is adopted, there is a problem in correction accuracy. In addition, various corrections are made manually by visually observing the deviation on the screen,
There is also a problem that adjustment takes time. Therefore, as a method for automatically correcting the deflection distortion, an electron beam deflection control device of Japanese Patent Laid-Open No. 58-24186 is proposed.

FIG. 6 shows a block diagram of a conventional image correction apparatus capable of automatic correction. The electron beam position is detected from the index phosphor coated on the shadow mask surface 43.
0 is detected, and a signal for convergence correction or geometric distortion correction is generated by the processing device 66 from this detection signal. The signal from the processor 66 is supplied to the waveform generator 52 to generate each scanning waveform for driving the convergence yoke 44 and the deflection yoke 46, and the convergence and geometric distortion can be automatically corrected.

As described above, it is possible to automatically correct the position control of the electron beam for correcting the convergence, the geometric distortion and the like.

[0005]

However, in the conventional structure as described above, since the adjustment according to the scanning method and the field is not performed, when the signal of the interlaced scanning method is input, the first field and the second field are input. Since the position of the scanning line is vertically displaced, it is not possible to accurately detect the amount of convergence deviation, and in multi-scan televisions, etc. where various signals are input, there is a decrease in correction accuracy and the time until convergence due to measurement instability. Had problems such as increase in

In view of the above point, the present invention discriminates the scanning system and the field, and performs the convergence adjustment separately for the odd field and the even field when the interlaced scanning signal is input, so that the difference in the amount of convergence deviation due to the difference in the fields is eliminated. An object of the present invention is to provide an automatic convergence device capable of accurately detecting the amount of convergence deviation, improving accuracy and shortening the convergence time.

[0007]

In order to achieve the above object, the present invention achieves the above object, a scanning method determining section for determining a scanning method based on a synchronization signal, a field determining section for performing field determination based on a synchronization signal, and a test synchronized with the synchronization signal. A test signal generating section for generating a signal, a projecting section for projecting a test signal from the test signal generating section, and a detecting section for detecting a deviation in convergence from the test signal projected on the projecting section, The control unit controls the convergence correction data based on the detection result from the detection unit, the scanning system determination result from the scanning system determination unit, and the field determination result from the field determination unit.

Further, the control unit has a structure for separately measuring the correction data of both the even field and the odd field.

Further, the control unit is provided with a memory for storing an average value of the correction data of the even field and the correction data of the odd field.

[0010]

According to the present invention, the synchronizing signal is supplied to the scanning system discriminating section and the field discriminating section, and the scanning system discriminating result and the field discriminating result are respectively detected by the constitution. These detection signals are supplied to the control unit, and the convergence correction is separately performed in the even field and the odd field. The correction data is averaged for the even field and the odd field, and is stored in the memory in the control unit. As a result, accurate correction data can be obtained even when the interlaced scanning signal is input, and automatic convergence with high accuracy and stability and short convergence time is performed without increasing the memory capacity.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of an automatic convergence device according to an embodiment of the present invention.

In FIG. 1, reference numeral 1 is a scanning method discriminating section for discriminating a scanning method from a deflection synchronizing signal, 2 is a field discriminating section for discriminating an odd field or an even field from the deflection synchronizing signal, and 3 is a deflection synchronizing signal. A test signal generator that generates a synchronized test signal. Reference numeral 5 denotes a projecting section for projecting the test signal from the test signal generating section 3, and 6
Is a detection unit that detects the amount of convergence deviation of the projection unit 5,
Reference numeral 4 denotes the discrimination result of the scanning method discrimination unit 1 and the field discrimination unit 2
It is a control unit that performs convergence correction on the projection unit 5 in accordance with the determination result of 1 and the detection result of the detection unit 6.

The operation of the automatic convergence device of this embodiment having the above-described structure will be described below. First, the scanning system determination unit 1 to which the deflection synchronization signal is input
Then, whether the input signal is interlaced scanning method,
The non-interlaced scanning system is discriminated by the phase relationship between the horizontal synchronizing signal and the vertical synchronizing signal, and the result is supplied to the control unit 4. The deflection synchronization signal is also supplied to the field discriminating unit 2 to discriminate whether the current field is an odd field or an even field, and the result is also supplied to the control unit 4.

The deflection synchronization signal is also supplied to the test signal generator 3, and a test signal synchronized with the deflection synchronization signal is generated during adjustment and supplied to the projection unit 5. The projecting unit 5 projects a test signal on an index phosphor (not shown) installed in a beam shield (not shown) in the projecting unit 5, and the detection unit 6 converges on the basis of the emission timing of the index phosphor. The amount of deviation is detected.

The control unit 4 controls the projection unit 5 so that the convergence deviation detected by the detection unit 6 is eliminated. At this time, the scanning system determination result and the field determination result are supplied to the control unit 4, and the control unit 4 separately corrects the odd field image and the even field image. The average of these two types of correction data is taken and stored. At the end of the adjustment, this correction data is read and used as the convergence correction data.

Next, each part of the automatic convergence adjusting device of the present invention will be described in detail. The scanning method discrimination unit 1 to which the deflection synchronization signal is supplied is configured as shown in FIG. 2, for example. In FIG. 2, 7 is a counter in which a horizontal deflection synchronization signal is input to the clock terminal and a vertical deflection synchronization signal is input to the reset terminal, and 8 is an output of the counter 7 stored at the timing of the vertical deflection synchronization signal. A first D flip-flop 9 for obtaining the number of horizontal scanning lines in one vertical scanning period, 9 inputs the output of the first D flip-flop 8,
Since the vertical deflection synchronization signal is supplied to the clock, the second D flip-flop 10 for displaying the counter output for one vertical deflection period before is output by the first flip-flop 8 and the second flip-flop 9 by the second flip-flop 9. It is a subtractor that takes the difference between the outputs.

The timing chart of FIG. 3 will be used to explain the operation of the scanning system discriminating unit shown in FIG. 2 and configured as described above. FIG. 3 shows an example when an NTSC signal is input. First, the counter 7 is supplied with the horizontal deflection synchronizing signal shown in FIG. 3A at the clock input terminal and the vertical deflection synchronizing signal shown in FIG. 3B at the reset input terminal. Therefore, the output of the counter 7 counts the number of horizontal scanning lines in one vertical scanning period, and then returns to 0 when the vertical deflection synchronizing signal is supplied to the reset terminal.

The output signal of this counter becomes a signal of about 9 to 11 bits depending on the number of horizontal scanning lines. The output of the counter 7 is input to the first D flip-flop 8,
The LSB output is connected, and the vertical deflection synchronizing signal is input to the clock input. Therefore, a signal as shown in FIG. 3D is always output to the output of the first D flip-flop 8. The output of the first D flip-flop 8 is connected to the input of the second D flip-flop 9, and the vertical deflection synchronization signal is supplied to the clock. Therefore, the output of the second D flip-flop 9 is as shown in FIG.
Compared to the output of the first D flip-flop 8 as shown in (e), the one before the vertical deflection scanning period is output.

The subtractor 10 receives the first D flip-flop output and the second D flip-flop output, and outputs the difference between them. Here, for example, if the input synchronizing signal is the NTSC system, as shown in FIG. 3D, the number of horizontal scanning lines counted in the odd field and the number of horizontal scanning lines counted in the even field which is one field before the Is always the opposite signal, the subtractor 10
Output is 1.

This difference occurs because interlaced scanning is performed in the NTSC system. The scanning system discrimination unit 1 uses this output as a scanning system discrimination signal. If a non-interlaced signal is input, the number of scanning lines in one field is the same in both odd and even fields, so the output of the subtractor 10 is zero. That is, when the scanning method is the non-interlaced method, the determination result is 0. As described above, the scanning method determination unit 1 determines whether the scanning method is the non-interlaced scanning method or the interlaced scanning method.

Further, the field discriminating unit 2 of FIG. 1 discriminates whether each field is an odd field or an even field when the discrimination result supplied from the scanning system discriminating unit 1 is the interlaced scanning system. At this time, the horizontal synchronizing signal is counted in the period from the vertical synchronizing signal to the next vertical synchronizing signal, and it is discriminated whether it is an odd field or an even field depending on the magnitude of the count number.

For example, in the NTSC system, when the count number of the horizontal synchronizing signal is 262, it is determined as the first field, and when it is 263, it is determined as the second field. In this way, the field discriminating unit 2 can discriminate the field. Also,
In the non-interlaced scanning system, the scanning system discrimination unit 1
The field determination signal is stopped by receiving the determination result that it is more non-interlaced, and 0 is always output as the field determination signal.

The test signal generator 3 generates a test signal in synchronization with the deflection synchronization signal. For example, assuming that the interlace scanning type synchronization signal is being input, the test signal is displayed on the index phosphor provided in the beam shield section of the display section 5 as shown in FIG.

In FIG. 4, reference numeral 11 is an index fluorescent substance installed in the beam shield portion of the projection portion 5, reference numeral 12 is a test signal of an odd field generated by the test signal generation portion 3 and projected by the projection portion 5, Reference numeral 13 is an even field test signal generated by the test signal generator 3 and displayed by the display unit 5. At this time, since the scanning method is interlaced scanning, odd field (odd) and even field (eve)
In n), the projection position changes vertically. This test signal causes the index phosphor to emit light. The light emission time interval of this index phosphor is measured by the detection unit 6 and used for convergence correction.

In FIG. 4, t _HO and t _He are times showing the horizontal beam detection positions in the odd field and the even field, and this time difference between the three color beams corresponds to the amount of convergence deviation. Further, t _VO and t _VE are times indicating the beam detection positions in the vertical direction in the case of odd fields and even fields, and the time difference corresponds to the amount of convergence deviation in the vertical direction as in the horizontal direction.

The control unit 4 performs convergence correction for each of the odd field and the even field based on the discrimination results of the scanning system discrimination unit 1 and the field discrimination unit 2. FIG. 5 shows a block diagram of the inside of the control unit 4. In FIG. 5, 1
Reference numeral 4 denotes a data calculation unit 15 and a memory 1 in the control unit 4.
6, a CPU that controls the correction data generation unit 17, a correction data generation unit that generates correction data to be supplied to the projection unit 5, a memory 16 that stores the correction data, and a data calculation unit that calculates the correction data Is.

The operation of the control unit 4 configured as above will be described below. The CPU 14 receives the scanning system determination result and the field determination result, and at the same time controls the correction data generating unit 7 to generate correction data that eliminates the amount of convergence deviation from the detection result. This is corrected separately for even and odd fields.

The thus separately corrected data are averaged by the data calculator 15 and stored in the memory 16. The reason for averaging the correction data here is to reduce the memory capacity without impairing the correction accuracy, and thus it is possible to realize an automatic convergence apparatus with high accuracy and low cost.

Further, when the signal of the non-interlaced scanning system is input, the correction data becomes the same because the projection positions of the even field and the odd field are the same. Even if there is an influence of noise or the like, since the correction data of the even field and the correction data of the odd field are averaged, the influence of the noise or the like is reduced.

As described above, according to this embodiment, the scanning system and the field are discriminated, the correction data of the even field and the correction data of the odd field are separately adjusted, and this data is averaged to obtain a multi-scan monitor. Even in a television to which various signals are input, it is possible to accurately and stably perform automatic convergence adjustment without increasing the memory amount.

In the description of FIG. 2, even if the subtractor 10 is replaced with a mismatch circuit, the same operation can be obtained.

[0032]

As described above, according to the present invention, since the scanning method and the field are discriminated and the odd field and the even field are separately adjusted when the interlaced scanning signal is inputted, the difference in the amount of convergence deviation due to the difference in the field is eliminated. As a result, the amount of convergence deviation can be accurately detected, and the accuracy can be improved and the convergence time can be shortened.

Further, the scanning method and the field are discriminated,
Convergence correction is performed for each field and the average value of the correction values of the two fields is used as the correction data, so that it can be performed accurately and stably regardless of the scanning method of the input signal without increasing the memory capacity. Convergence adjustment can be performed.

[Brief description of drawings]

FIG. 1 is a block diagram of an automatic convergence device according to an embodiment of the present invention.

FIG. 2 is a detailed block diagram of a scanning system discrimination unit of the embodiment.

FIG. 3 is a timing chart of the scanning system discriminating unit of the embodiment.

FIG. 4 is a diagram showing a relationship between a test signal and an index phosphor of the same example.

FIG. 5 is a block diagram of a control unit of the same embodiment.

FIG. 6 is a block diagram of an automatic convergence device in a conventional example.

[Explanation of symbols]

 1 Scanning Method Discrimination Unit 2 Field Discrimination Unit 3 Test Signal Generation Unit 4 Control Unit 5 Projection Unit 6 Detection Unit 7 Counter 8 First Flip-Flop 9 Second Flip-Flop 10 Subtractor 11 Index Phosphor 12 Odd Field Test Signal 13 even field test signal 14 CPU 15 data calculator 16 memory 17 correction data generator

Claims (3)

[Claims] 1. A scanning method discriminating section for discriminating a scanning method from a synchronizing signal, a field discriminating section for discriminating a field from the synchronizing signal, a test signal generating section for generating a test signal synchronized with the synchronizing signal, and A projecting section for projecting a test signal from the test signal generating section, a detecting section for detecting a deviation in convergence from the test signal projected on the projecting section, a detection result from the detecting section and the scanning method. An automatic convergence device, comprising: a scanning system determination result from a determination unit and a control unit that controls convergence correction data based on a field determination result from the field determination unit. 2. The automatic convergence apparatus according to claim 1, wherein the control unit measures the correction data of both the even field and the odd field separately. 3. The automatic convergence apparatus according to claim 2, wherein the control unit includes a memory for storing an average value of the correction data of the even field and the correction data of the odd field.