JPH06303623A - Cathode ray tube controller - Google Patents

Abstract

PURPOSE:To provide the cathode ray tube controller executing deflection control in a short adjustment by obtaining a convergence error at a high speed with respect to a picture correction device in a color television receiver. CONSTITUTION:This controller is provided with a test signal generating section 1 generating a test signal to emit simultaneously electron beams 10a-10c from at least two electron guns 4, a photoelectric conversion section 7 converting a light detection signal from a fluorescent body coated to a shadow mask 3 detecting a position of the electron beams into an electric signal, a time width detection section 8 detecting a time width of the converted signal, a control signal generating section 9 controlling the electron beam based on the detected time width, and a deflection yoke 5 or the like controlling the electron beam with a control signal of the control signal generating section 9.

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 a cathode ray tube control device for automatically making various corrections.

[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), Of the electron beam is disturbed by the peripheral magnetic field, and color shift occurs on the shadow mask. For these various corrections, an analog correction waveform is created in synchronization with the horizontal and vertical scanning periods, and the size and shape of this waveform are changed to make adjustments. There is.

In addition, various corrections are manually performed by visually observing deviations on the screen, which causes a problem that adjustment time is required. Therefore, as a method with high convergence accuracy, a digital convergence apparatus of Japanese Patent Publication No. 59-8114 is proposed, and as a method of automatically correcting deflection distortion, an electron beam deflection control apparatus of Japanese Patent Publication No. 58-24186 is proposed. ing.

FIG. 11 shows a block diagram of a conventional image correction apparatus capable of automatic correction. The detector 32 detects the electron beam position from the index phosphor coated on the shadow mask surface 31 of the cathode ray tube 30, and the processing device 3 outputs signals for convergence correction and geometric distortion correction from this detection signal.
Created in 3. The signal from the processing unit 33 is supplied to the waveform generator 34 to generate each scanning waveform for driving the convergence yoke 35 and the deflection yoke 36, and automatically corrects the convergence and geometric distortion.

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

[0006]

However, in the above configuration, when the electron beam position is detected by the detector,
Since the beam of each color is sequentially projected at each adjustment point, three kinds of electron beam position detection operations are required, which causes a problem that the adjustment time becomes long.

In view of the above point, the present invention, when detecting the electron beam position by the detector, projects at least two colors out of the three primary color beams at the same time, and outputs R, G depending on the time width or the maximum amplitude of the detected signal. , B to detect the concentrated state of the beam position, the detection time is shortened, and an object of the present invention is to provide a cathode ray tube control device with a short adjustment time.

[0008]

A first invention is a test signal generating means for generating a test signal for simultaneously emitting electron beams from at least two electron guns, and a detecting means for detecting the position of the electron beams. A photoelectric conversion means for converting the light detection signal from the detection means into an electric signal; a time width detection section for detecting the time width of the detection signal output from the photoelectric conversion means; and an electron beam controlled by the time width signal. The configuration is characterized by including a control signal generating means and a deflecting means for controlling the electron beam by the control signal.

According to a second aspect of the present invention, there are provided a test signal generating means for generating a test signal for simultaneously emitting electron beams from at least two electron guns, a detecting means for detecting the position of the electron beam, and a detecting means. A photoelectric conversion unit that converts a light detection signal into an electric signal, a maximum amplitude detection unit that detects the maximum amplitude of the detection signal output from the photoelectric conversion unit, a control signal generation unit that controls the electron beam by the maximum amplitude signal, The configuration is characterized in that a deflection means for controlling the electron beam by a control signal is provided.

[0010]

According to the first aspect of the present invention, the test signal generated by the test signal generating means is supplied to the electron gun with the above-mentioned structure.
Here, electron beams of at least two colors are simultaneously emitted,
The detection means detects the position of this electron beam, and the photoelectric conversion means converts the detection signal from the detection means into an electric signal. The time width detecting means detects the time width of the generation period of this signal, and the control signal generating means generates a control signal for controlling the electron beam by the time width signal, and supplies the control signal to the deflecting means to control the electron beam. Therefore, the deflection distortion is corrected.

According to the second aspect of the present invention, the test signal generated by the test signal generating means is supplied to the electron gun, the electron beams of at least two colors are emitted at the same time, and the position of the electron beam is detected by the detecting means. Is detected, and the photoelectric conversion means converts the detection signal from the detection means into an electric signal. The maximum amplitude detection means detects the maximum amplitude of this signal, the control signal generation means generates a control signal for controlling the electron beam by the maximum amplitude signal, and supplies the control signal to the deflection means to deflect the electron beam. Corrects the distortion.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram of a cathode ray tube control apparatus according to an embodiment of the first invention.

In FIG. 1, 1 is a test signal generator for generating a test signal for convergence correction and deflection distortion correction, 2 is a cathode ray tube having a shadow mask 3 coated with an index phosphor, and 4 is a cathode ray tube 2. Electron gun, 5
Is a convergence yoke of the cathode ray tube 2, 6 is the cathode ray tube 2
Deflection yoke of the electron beam 10 is applied to the shadow mask 3
A photoelectric conversion unit that converts a light detection signal emitted by hitting the index phosphor applied to the electric signal into an electric signal, 8 a time width detection unit that detects a signal period of an output signal of the photoelectric conversion unit 7, and 9
Is a control signal generator that generates a deflection control signal based on the time width detected by the time width detector 8. Also, 10a, 1
0b and 10c are R, G, which are emitted from the electron gun 4, respectively.
B electron beam.

The operation of the cathode ray tube control device of this embodiment having the above-described structure will be described below. The test signal generated by the test signal generator 1 is supplied to the electron gun 4 of the cathode ray tube 2. As a result, the electron gun 4 emits electron beams 10a, 10b, and 10c. When the electron beams 10a, 10b, 10c hit the index phosphor coated on the shadow mask 3, they emit light. The emitted light signal is converted into an electric signal by the photoelectric conversion unit 7. For example, as the photoelectric conversion unit 7, a photomultiplier tube, a photo diode, or the like is used. This photoelectrically converted signal is supplied to the time width detection unit 8 and the signal period is measured. The control signal generator 9 changes the control signal based on the time width signal until the signal is minimized, and supplies it to the convergence yoke 5 and the deflection yoke 6. At this time, when the time width signal becomes the minimum, it is determined that the deflection distortion is corrected.

Next, the deflection distortion correction process will be described with reference to FIG. The test signal generator 1 simultaneously generates a G test signal and a B test signal as shown in FIGS. However, on the screen, it is assumed that this signal is displayed deviated on the index phosphor as shown in FIG. 2B due to the convergence deviation. Here, 11 is a shadow mask 3
Is an index phosphor coated on the shadow mask 12, 12 is an electron beam by the G test signal projected on the shadow mask 3, 1
Reference numeral 3 is an electron beam by the B test signal similarly projected. At this time, the photoelectric conversion signal detected by the photoelectric conversion unit 7 is separated and detected into a detection signal by the G test signal and a detection signal by the B test signal as shown in FIG.

The time width detector 8 measures the time width t ₁ of these detection signals and supplies it to the control signal generator 9. The control signal generator 9 generates a deflection control signal for horizontal deflection correction of the B electron beam based on this measurement data and supplies it to the convergence yoke 5. As a result, the horizontal projection position of the B electron beam changes, so that the generation timing of the detection signal by the B test signal changes. When the control signal is sequentially changed and the correction amount is increased, the time timings of the detection signals coincide with each other as shown in FIG. 2C, and at this time, the time width becomes the minimum value t ₂ .

As the value is changed, it shifts in the opposite direction as shown in FIG. 2 (c), and the time width increases. FIG. 3 shows the relationship between the correction amount and the time width. Since because state convergence is suits is when Utsude position of each movies out test signals match, the detection timing may coincide, the correction time width of the detection signal becomes minimum t ₂ weight x ₂ It is time for Therefore, if the correction amount is sequentially increased from x ₁ , the time width is decreased, and the increase is started again, the correction amount x ₂ is brought into a state in which the convergence is matched, and the horizontal adjustment at that point is completed.

Next, a case where the vertical adjustment is performed will be described with reference to FIG. After the adjustment in the horizontal direction is completed, the G test signal and the B test signal as shown in FIG. Then, as shown in FIG. 4 (B), the image is projected on the index phosphor provided on the shadow mask 3 while being inclined with respect to the scanning direction. Index phosphor 21 and electron beam 22 and B by G test signal
As for the relationship of the electron beam 23 by the test signal, as shown in FIG. 4B, it is assumed that the convergence is adjusted in the horizontal direction by adjustment, but the convergence is not adjusted in the vertical direction. At this time, since the index phosphor 21 is tilted with respect to the scanning direction, a vertical deviation in convergence appears in the detection signal output as a time difference.

FIG. 4C shows a G detection signal and a B detection signal in the photoelectric conversion output. The time width detection unit 8 has a time width t
₄ is measured and supplied to the control signal generator 9. The control signal generator 9 generates a deflection control signal for vertical deflection correction of the B electron beam based on the measurement data as in the horizontal deflection correction, and supplies the deflection control signal to the convergence yoke 5. This makes B
Since the vertical projection position of the electron beam changes, the generation timing of the detection signal by the B test signal changes.
At this time, when the control signal is sequentially changed and the correction amount is increased, the time timings of the detection signals coincide with each other as shown in FIG. 4C, and the time width becomes the minimum value t _{5 at} this time. As it is changed, it shifts to the opposite as shown in FIG. 4C, and the time width increases.

The state in which the convergence is matched means that the projected positions of the projected test signals match, so that the detection timings also match and the time width of the detected signal becomes the minimum t _5. Is. Therefore, if the correction amount is sequentially increased and the time width is reduced, it is determined that the convergence is achieved when it becomes the minimum, and the vertical adjustment at that point is completed. As shown in FIG. 4 (D), the horizontal and vertical convergences are adjusted in this manner.
As shown in, the convergence can be adjusted so that it is perfectly matched.

As described above, according to this embodiment, at least two types of test signals are simultaneously projected, the time width of the detected signals is measured, and the electron beam is controlled so as to minimize this time width. Conventionally, the convergence error amount can be detected in a shorter time than when the R, G, B, and test signals are sequentially projected, whereby the deflection control adjustment can be speeded up.

Next, an embodiment of the second invention will be described with reference to the drawings. FIG. 5 is a block diagram of a cathode ray tube control device according to an embodiment of the second invention. 5, the same blocks as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted below. Reference numeral 14 is a maximum amplitude detection unit that detects the maximum amplitude value from the output of the photoelectric conversion unit 7.

In the cathode ray tube control apparatus of this embodiment constructed as described above, the maximum amplitude detecting section 14 is different from the embodiment of the first invention. The operation will be mainly described below. In the test signal generator 1, FIG.
As in the case of b, at least two colors are simultaneously generated, for example, a G test signal and a B test signal are simultaneously generated. However, it is assumed that the display is shifted on the index phosphor as shown in FIG. 6B due to the convergence shift on the screen.

Here, as in FIG. 2, 11 is an index phosphor coated on the shadow mask 3, 12 is a G test signal projected on the shadow mask 3, and 13 is a B test signal similarly projected. Is. At this time, the photoelectric conversion signal detected by the photoelectric conversion unit 7 is separated and detected into a detection signal by the G test signal and a detection signal by the B test signal as shown in FIG. Here, the maximum value detection unit 14 determines the maximum amplitude value y ₁ of these detection signals in the test signal period.
Is measured and supplied to the control signal generator 9. The control signal generator 9 generates a deflection control signal for horizontal deflection correction of the B electron beam based on this measurement data and supplies it to the convergence yoke 5.

Since this changes the horizontal projection position of the B electron beam, the generation timing of the detection signal by the B test signal changes. At this time, if the control signal is sequentially changed and the correction amount is increased, the time timings of the detection signals match as shown in FIG. 6C, and at this time, the maximum amplitude value of the detection signals during the test period is The maximum value is y ₂ . It should be noted that as it is changed, it shifts oppositely as shown in FIG. 6C, and the maximum amplitude value decreases.

Thus, the relationship between the correction amount and the maximum amplitude value is as shown in FIG. The state in which the convergence is matched at this time is a time when the projected test signals are matched, so that the time timings of the detection signals are also matched and the maximum amplitude value becomes the maximum y _2. It was when it was ₂ . Therefore sequentially increasing the correction amount from x _1, when gradually increasing the maximum amplitude value, is the correction amount when club decrease again x ₂ as a boundary is a state in which the correction amount x ₂ to meet the convergence adjustment at that point To finish.

Here, the process of obtaining the maximum amplitude value will be described in detail with reference to FIGS. 8 and 9. FIG. 8 shows the maximum amplitude detector 1
4 is a circuit diagram showing an example of the configuration of No. 4, and FIG. 9 is a timing diagram for explaining the operation. In FIG. 8, 15
Is an input buffer to which a photoelectric conversion signal is supplied, 16 is a diode, 17 is a current limiting resistor, 18 is a hold capacitor, 19 is a reset switch, and 20 is an output buffer.

When the G test signal and the B test signal as shown in FIG. 9A are supplied to the electron gun 4, an electron beam is generated, which is projected on the index phosphor, and the maximum amplitude detecting section 14 displays it. It is assumed that a photoelectric conversion signal such as 9 (b) is supplied.

The reset signal is generated at the rising edge of the test signal as shown in FIG.
Supply to. Then, when the test signal rises, the reset signal having a positive logic is supplied to the reset switch 19, and the reset switch 19 is turned on. At this time, the electric charge accumulated in the hold capacitor 18 is discharged through the current limiting resistor 17 and the reset switch 19. Then, V ₂ becomes 0V, and the maximum amplitude value output also becomes 0V. When the reset signal has a negative logic and the photoelectric conversion signal becomes large so that V ₁ > V ₂ , the diode 16 is turned on and electric charge is accumulated in the hold capacitor 18 so that the voltage V ₁ = V ₂ . When the photoelectric conversion signal begins to decrease and V ₁ <V ₂ , the diode 16 is turned off and V ₂
And the output of the output buffer 20 holds the peak value of the photoelectric conversion signal.

This is shown in the peak hold output of FIG. 9 (d). This peak value is held until the reset signal becomes positive logic next time. In this way, the maximum amplitude detector 14 can detect the maximum amplitude of the test signal period. By capturing the detected data with the data capture signal at the time of the fall of the test signal as shown in FIG. 9E, only the maximum amplitude value can be retrieved as shown in FIG. 9F. The maximum amplitude value is changed by sequentially changing the correction amount, and if the maximum amplitude value of the detection signal within the test period is the maximum correction amount, it is determined that the convergence is satisfied.

Next, a case where the vertical adjustment is performed will be described with reference to FIG. After the horizontal adjustment is completed, FIG.
The G test signal and the B test signal as shown in FIG. Then, as shown in FIG. 10 (B), the image is projected on the index phosphor installed on the shadow mask while being obliquely inclined with respect to the scanning direction. The relationship between the index phosphor 21, the electron beam 22 based on the G test signal, and the electron beam 23 based on the B test signal is shown in FIG.
As shown in (B), it is assumed that the convergence is adjusted by adjusting in the horizontal direction, but the convergence is not adjusted in the vertical direction. At this time, since the index phosphor 21 is inclined with respect to the scanning direction, the vertical deviation of the convergence appears as a time difference in the detection signal output.

The G detection signal and the B detection signal in the photoelectric conversion output at this time are shown in FIG. The maximum amplitude detector 14 measures the maximum amplitude y ₄ within the test signal period and supplies it to the control signal generator 9. The control signal generator 9 generates a deflection control signal for vertical deflection correction of the B electron beam based on the measurement data as in the horizontal deflection correction, and supplies the deflection control signal to the convergence yoke 5. As a result, the vertical projection position of the B electron beam changes, so that the generation timing of the detection signal by the B test signal changes. When the control signal is sequentially changed and the correction amount is increased, the temporal timings of the detection signals coincide with each other as shown in FIG. 10C, and the maximum amplitude becomes the maximum value y ₅ . It should be noted that as it is changed, it shifts in the opposite manner as shown in FIG. 10C, and the maximum amplitude value decreases.

The state in which the convergence is matched means that the projected positions of the projected test signals match, so that the detection timings also match and the maximum amplitude value within the test signal period is the maximum value y ₅ It was when. Therefore, the correction amount is sequentially increased and the maximum amplitude value is increased, and when the maximum amplitude value becomes the maximum, it is determined that the convergence is achieved, and the vertical adjustment at that point is completed. In this way, by adjusting the convergence in the horizontal direction and the convergence in the vertical direction, it is possible to adjust the convergence to a perfect state as shown in FIG.

As described above, according to the second embodiment,
By projecting two or more test signals simultaneously, measuring the maximum amplitude of the detected signal, and controlling the electron beam to maximize the maximum amplitude value, the conventional R, G, B, and test signals are sequentially projected. The convergence error amount can be detected in a shorter time than when it is being output, and thus the deflection control adjustment can be speeded up.

In the above embodiment, the case where the convergence of the B and G beams is matched has been described, but it goes without saying that the same adjustment can be made with other combinations of beams. In addition, two types of test signals are displayed simultaneously,
Although only one type of convergence adjustment has been described, it goes without saying that three types of test signals may be simultaneously projected and two types of convergence adjustment may be performed at the same time.

Further, the adjustment of only one correction point has been described, but it is needless to say that this can be divided on the screen to perform dynamic deflection correction at a plurality of adjustment points. Further, although the deflection control device for the cathode ray tube has been described, it is needless to say that the present invention can be applied to other displays such as a projection type display in which a plurality of beams need to be concentrated.

Furthermore, although an example has been described as the maximum amplitude detecting section, it goes without saying that other configurations may be used.
In addition, the embodiments of the two types of cathode ray tube control devices have been described.
It goes without saying that these may be used in combination.

[0038]

As described above, according to the present invention,
At least two colors of R, G, and B test signals are simultaneously projected, the time width or maximum amplitude of the light emission signal from the index phosphor is measured, and the convergence deviation is detected by this data. Compared with the case where G and B are sequentially displayed, the convergence error amount can be detected in a shorter time, which can speed up the adjustment and has a large practical effect.

[Brief description of drawings]

FIG. 1 is a block diagram of a cathode ray tube control device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a horizontal correction operation of the embodiment.

FIG. 3 is a characteristic diagram showing a relationship between a convergence correction amount and an output of a time width detection unit in the embodiment.

FIG. 4 is a diagram showing an operation of vertical correction in the same embodiment.

FIG. 5 is a block diagram of a cathode ray tube control device according to a second embodiment of the present invention.

FIG. 6 is a diagram showing a horizontal direction correction operation of the embodiment.

FIG. 7 is a characteristic diagram showing the relationship between the convergence correction amount and the maximum amplitude detection unit output of the same embodiment.

FIG. 8 is a circuit diagram showing an example of an internal circuit of a maximum amplitude detector in the same embodiment.

FIG. 9 is an operation waveform diagram of the maximum amplitude detection unit in the embodiment.

FIG. 10 is a diagram showing an operation of vertical correction in the same embodiment.

FIG. 11 is a block diagram of a conventional electron beam deflection control device.

[Explanation of symbols]

 1 Test Signal Generator 2 Cathode Ray Tube 3 Shadow Mask Coated with Index Phosphor 4 Electron Gun 5 Convergence Yoke 6 Deflection Yoke 7 Photoelectric Converter 8 Time Width Detector 9 Control Signal Generator 10 Electron Beam 11 Index Phosphor 12 Projection Output G test signal 13 Projected B test signal 14 Maximum amplitude detector

Claims (2)

[Claims] 1. A test signal generating means for generating a test signal for simultaneously emitting electron beams from at least two electron guns, a detecting means for detecting the position of the electron beam, and a light detection from the detecting means. A photoelectric conversion unit that converts a signal into an electric signal, a time width detection unit that detects a time width of a detection signal output from the photoelectric conversion unit, and a control signal generation unit that controls the electron beam according to the detected time width. And a deflection means for controlling the electron beam according to a control signal of the control signal generation means. 2. A test signal generating means for generating a test signal for simultaneously emitting electron beams from at least two electron guns, a detecting means for detecting the position of the electron beam, and a light detection from the detecting means. A photoelectric conversion unit that converts a signal into an electric signal, a maximum amplitude detection unit that detects the maximum amplitude of the detection signal output from the photoelectric conversion unit, and a control signal generation that controls the electron beam by the detected maximum amplitude signal And a deflection means for controlling the electron beam according to the control signal of the control signal generation means.