KR20040090511A - Apparatus for controlling auto convergence of projection TV - Google Patents

Abstract

PURPOSE: An apparatus for controlling auto-convergence of a projection TV is provided to correct auto-convergence without having errors irrespective of brightness of indoor illumination. CONSTITUTION: An apparatus for controlling auto-convergence of a projection TV includes a screen(119) on which an image corresponding to RGB video signals is displayed, a test pattern generator(113) for generating a test pattern with a predetermined size for controlling auto-convergence, and sensors(119a,119,b,119c,119d,119e,119f,119g,119h) for sensing the test pattern. The apparatus further includes a voltage removing unit(120) for removing a DC voltage from the value sensed by the sensors, an A/D converter(121) for converting an analog signal output from the voltage removing unit into a digital signal, a memory(122) for storing a reference value for controlling auto-convergence, and a digital convergence unit(114) for outputting a signal to automatically control convergence according to whether the output of the A/D converter corresponds to the reference value stored in the memory.

Description

Apparatus for controlling auto convergence of projection TV

TECHNICAL FIELD The present invention relates to TVs, and more particularly, to an auto-convergence control apparatus of a projection TV.

In general, video display devices are being introduced to consumers in various forms, starting with small models such as 14-inch analog receivers and projection TVs of 60 inches or more.

Projection TV is a device that displays images on the screen by projecting the colors of R, G, and B on the screen using respective CRTs.The quality of the projection TV is W / U (White Uniformity), B / U (Bright). It consists of various items such as Uniformity, Convergence, Focus, and Distortion.

Here, convergence means that the R (Red), G (Green), and B (Blue) beams emitted by the electron gun are collected at a point on the screen by the magnetic field of the deflection yoke, but the influence of the abnormality or the magnetic field of the deflection yoke If the beam is not deflected as desired, mis-convergence occurs and color shift occurs on the screen.

In other words, three beams of R, G, and B must be gathered exactly at one point to become white. When the image is miss-converged, abnormally colored lines such as R, G, and B will be displayed next to the white line. It acts as a factor to decrease.

Therefore, in order to show white color, the light projected from each C, R, G, and B tubes should be collected in one place. Here, the convergence of R, G, and B light in one place is called auto convergence. As the digital TV broadcasting starts, a projection TV is in the spotlight as a display that meets the needs of a large screen.

Such auto convergence generates a specific pattern on the screen, and uses the optical sensor to determine the degree of convergence and then corrects it.

Hereinafter, with reference to the accompanying drawings illustrating a convergence adjustment apparatus of the projection TV according to the prior art.

1 is a block diagram showing the configuration of the convergence adjustment device of the projection TV according to the prior art, Figure 2 is a view showing a detection method of the optical sensor according to the movement of the measurement pattern, Figure 3 is a light according to the movement of the measurement pattern This is a waveform diagram showing the output waveform of the sensor.

As shown in FIG. 1, the convergence adjusting apparatus of the projection TV according to the related art includes a screen 10 for displaying an image signal and first to eighth sensing units mounted on a predetermined area of the screen 10. 11 to 18, an amplification unit 20 that receives the sensed values detected through the first to eighth sensing units 11 to 18 and amplifies and outputs the amplified by a predetermined multiple, and amplified by the amplifying unit 20. The comparison unit 30 receives and compares the amplification value to the inverting (-) terminal and the non-inverting (+) terminal as preset, and the AND gate 40 receiving the output value of the comparing unit 30 and performing an AND operation. ), An inverter 50 for inverting the output of the AND gate 40, a D flip-flop 60 for receiving and latching an output value of the inverter 50, and the D flip-flop 60. Do not output the control signal to receive the latched data and adjust the convergence It consists of the ICCOM 70.

In the first to eighth sensing units 11 to 18, the first, third, fifth, and seventh sensing units 11, 13, 15, and 17 are formed at the centers of the four sides of the screen 10. The second, fourth, sixth and eighth detectors 12, 14, 16 and 18 are located at the four corners of the screen 10. In addition, the first to fourth sensing units 11 to 14 are divided into a first group, and the fifth to eighth sensing units 15 to 18 are divided into a second group, and the first to eighth sensing units ( 11 to 18 include a plurality of first and second photosensors A and B, as shown in FIG.

In addition, the amplifying unit 20 is a first to receive and amplify the sensed values respectively sensed by the first and second optical sensors (A) (B) in the first to fourth sensing units (11 to 14) A second amplifying unit 21 and a second amplifying unit for receiving and amplifying sensing values sensed through the first and second optical sensors A and B by the fifth to eighth sensing units 15 to 18, respectively; It consists of 22.

The first amplifier 21 may include a first amplifier 21a for receiving and amplifying a value detected by the first optical sensor A from the first to fourth detectors 11 to 14. The first to fourth sensing units 11 to 14 are configured to receive and amplify a sensing value sensed through the second optical sensor B to amplify the second amplifier 21b. The second amplifier 22 is a third amplifier (22a) for receiving and amplifying the sensed value detected by the first optical sensor (A) in the fifth to eighth sensing unit (15 to 18), The fifth to eighth sensing units 15 to 18 may include a fourth amplifier 22b that receives and amplifies a sensing value detected through the second optical sensor B.

The comparator 30 may include a first comparator 31 configured to receive and compare output values of the first and second amplifiers 21a and 21b through inverted (-) and non-inverted (+) terminals, respectively, And a second comparator 32 that receives the output values of the third and fourth amplifiers 22a and 22b through the inverting (-) and non-inverting (+) terminals, respectively, and compares them.

Referring to the operation of the automatic convergence adjustment device of the projection TV according to the prior art configured as described above are as follows.

When the user selects the auto convergence adjustment mode, the first to eighth detection units 11 to 18 detect the position of the pattern generated for the convergence adjustment, and the first to eighth detection units 11 to 18. ) And the detected value detected through the first optical sensor A is input to the second and fourth amplifiers 21b and 22b, and the detected value detected through the second optical sensor B is the first and the second It is input to the three amplifiers 21a and 22a and amplified by twice as much as the amplification degree of the second and fourth amplifiers 21b and 22b and output.

The amplified value b1 amplified by the first amplifier 21a is input to the inverting (−) terminal of the first comparator 31 and amplified value a1 amplified by the second amplifier 21b. Is input to the non-inverting (-) terminal of the first comparator 31 and outputs a comparison value c1. The amplified value b2 amplified by the third amplifier 22a is input to the inverting (−) terminal of the second comparator 32 and amplified by the fourth amplifier 22b. Is input to the non-inverting (+) terminal of the second comparator 32 to output a comparison value c2.

The output values of the first and second comparators 31 and 32 are inputted from the AND gate 40 to the inverter 50, and the values inverted through the inverter 50 are converted to the D flip-flop ( 60 is inputted and latched to enter the input of the microcomputer 70.

Herein, the sensing method according to the movement of the measurement pattern through the first to eighth sensing units 11 to 18 will be described with reference to FIGS. 2 and 3.

First, when the measurement pattern is red (even when green or blue) is moved downward for the pattern, it can be described through the detection process of the third sensor (13). First, as shown in FIG. 2, when the pattern is at the preset first sensing position t1, since the pattern does not overlap with both the first optical sensor A and the second optical sensor B, light is not detected. As shown in FIG. 3, it can be seen that a low signal is also output as a low signal is applied to both the first and second amplifiers 21a and 21b.

In addition, a low signal output from the first and second amplifiers 21a and 21b is input to the non-inverting (+) and inverting (-) terminals of the first comparator 31, respectively. The one comparator 31 outputs a high signal. This is because a slight pull-up resistor is connected to the non-inverting (+) terminal of the first comparator 31.

As shown in FIG. 2, when the pattern is at the second detection position t2, the first optical sensor A overlaps about 1/2 of the pattern, and the second optical sensor B is still It can be seen that the light is not detected because the patterns do not overlap. In this case, since the output value of the second amplifier 21b is larger than the output value of the first amplifier 21a, the first comparator 31 continues to output a high signal.

In addition, as shown in FIG. 2, when the pattern is at the third detection position t3, the first optical sensor A overlaps the pattern, and the second optical sensor B overlaps about 1/2. The first amplifier 21a in which the output value of the second amplifier 21b, which receives the detection value of the first optical sensor A, receives the detection value of the second optical sensor B, is an overlapping state. Will be twice the output of (A = 2B).

However, since the amplification degree of the first amplifier 21a is twice as large as that of the second amplifier 21b, the output values of the first amplifier 21a and the second amplifier 21b are the same, and this is input. The output value of the received first comparator 31 outputs a low signal from thereafter.

In this manner, a signal is also output from the second comparator 32, and outputs of the first and second comparators 31 and 32 are calculated by being inputted to the inverter 50 and inverted. A high signal is outputted, and the signal is inputted to the clock of the D flip-flop 60 to latch data, and then a high signal is inputted to the microcomputer 70.

The microcomputer 70 determines that the position of the pattern is the third set position t3 when the port connected to the microcomputer 70 goes from low to high, and thus the initial stage of the pattern is determined. The distance from the position to the third set position t3 is measured to determine how far the convergence is, and the correction control signal is output accordingly.

As described above, the projection TV according to the prior art has the following problems.

First, since the detector mounted on the screen recognizes not only the light of the test pattern, but also the indoor lighting, it generates a basic voltage to the sensor mounted on the detector and can change the on time of the comparator. it's difficult.

Second, in the vertical test, the progress of the pattern coincides with the progress of the scan in the case of sequential scanning, and there is no error in distance calculation. In the case of interlaced scan, the microcomputer recognizes the pattern and the progress of the scan every field. This may cause an error.

Third, it takes a certain time to approach the test pattern to the sensor, so the production efficiency is reduced in the production process.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a projection TV's auto-convergence adjusting device that can perform error-free auto convergence correction irrespective of the brightness of the indoor lighting.

1 is a block diagram showing an auto convergence adjustment device of a projection TV according to the prior art.

2 is a diagram illustrating the detection criteria according to the movement of the measurement pattern

3 is a waveform diagram illustrating an output waveform of a comparator according to an output waveform of the amplifier illustrated in FIG. 1.

Figure 4 is a block diagram showing an auto convergence adjustment device of the projection TV according to the present invention

FIG. 5 is a diagram illustrating a configuration of a sensing unit illustrated in FIG. 4.

6 (a) and 6 (b) are diagrams illustrating a horizontal / vertical test pattern generated by the test pattern generator shown in FIG. 4.

7A to 7D are diagrams illustrating voltage waveforms output according to positions of a sensing unit.

Explanation of symbols for main parts of the drawings

110: tuner 111: image processing unit

112: main control unit 113: test pattern generation unit

114: convergence control unit 115: power amplification unit

116: video switching unit 117: amplifier

118: Convergence York 119: Screen

119a to 119h: detection unit 120: removal unit

121: A / D converter 122: memory

123: PRT

In order to achieve the above object, an apparatus for adjusting auto-convergence of a projection TV according to the present invention includes a screen for displaying R, G, and B image signals, and a test pattern generator for generating a test pattern having a predetermined size for auto-convergence adjustment. And a detector for detecting a pattern generated by the test pattern generator, a remover for removing a voltage of a DC component from a detected value detected through the detector, and an analog signal output through the remover. The A / D converter converts the signal to the A / D converter, a memory for storing a reference value for auto-convergence adjustment, and a signal so that the convergence is automatically adjusted according to whether the output of the A / D converter matches the reference value previously stored in the memory. It is configured to include a digital convergence unit for outputting.

Preferably, the sensing unit is composed of one optical sensor, which is characterized by the fact.

More preferably, the test pattern generation unit generates a pattern giving a gradual change in brightness to the left and right when the horizontal test is to be performed, and generates a pattern giving a gradual change in brightness to the vertical test when the vertical test is to be performed. It features.

Hereinafter, the auto-convergence adjustment apparatus of the projection TV according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 4 is a block diagram illustrating an apparatus for adjusting auto-convergence of a projection TV according to the present invention, FIG. 5 is a detailed block diagram of the sensor board shown in FIG. 4, and FIGS. 6 and 7 are test patterns shown in FIG. 4. 8 illustrates a pattern generated by the generation unit, and FIG. 8

As shown in FIG. 4, the apparatus for auto-convergence adjustment of the projection TV according to the present invention includes a tuner 110 for tuning an image signal received from an antenna, and a video signal tuned through the tuner 110. Generate a test pattern for generating a test pattern of a predetermined size for auto-convergence adjustment, an image processing unit 111 for processing an image signal displayable on the 119, a screen 119 for displaying R, G, and B video signals The voltage of the DC component in the detection value detected by the unit 113, the detection unit 119a to 119g for detecting the pattern generated by the test pattern generator 113, and the detection unit 119a to 119g. A remover 120 for removing the PDP, an A / D converter 121 for converting the analog signal output through the remover 120 into a digital signal, and a memory 122 for storing a reference value for auto convergence adjustment. ) And A convergence control unit 114 for outputting a signal so that the convergence is automatically adjusted according to whether the output of the A / D converter 121 and the reference value previously stored in the memory 123 are matched, and the convergence control unit 114 of the A power amplifier amplifying input power according to a control signal, an image signal processed by the image processor 111, a test pattern generated by the test pattern generator 113, and the power amplifier 115. The image switching unit 116 for selectively outputting the signal output from the output, the amplifier 117 for amplifying the output signal of the image switching unit 116, and for adjusting the convergence according to the output of the amplifier 117 A convergence yoke 118 and a PRT 124 which processes the output of the convergence yoke 118 to be displayable on the screen 119.

Referring to the operation of the automatic convergence adjustment device of the projection TV according to the present invention configured as described above are as follows.

Each sensor board constituting the sensing units 119a to 119h mounted on the screen 119 is provided with a plurality of optical sensors. However, in the present invention, as shown in FIG. 5, the optical sensors A Only one is installed.

The test pattern generated by the test pattern generator 113 is a horizontal test pattern and a vertical test pattern, and the horizontal test pattern is left / right luminance as shown in FIG. 6A. It is generated by giving a gradual change, and the vertical test pattern is generated by giving a gradual change of luminance up and down, as shown in FIG.

Therefore, after the producer adjusts the convergence in the factory, the state is stored in the memory 122, and when the user executes the auto convergence, the pattern generated by the test pattern generator 113 is specified as in the conventional method. Instead of moving toward the sensor at, the pattern is illuminated at a time large enough to cover the sensing units 119a to 119g at once, so that the brightness of the light is different depending on the position covered by the sensing units 119a to 119g. It can be seen that the voltage waveform generated also varies.

That is, when the shape of the test pattern generated by the test pattern generator 113 covers the sensing unit is the same as that of FIG. 7 (a) or (c), the case of FIG. It can be seen that the voltage waveform as shown in (b) of FIG. 7 and the voltage waveform as shown in (d) of FIG. 7 which is higher than that shown in FIG.

Accordingly, it can be seen that the brightness of the light is generated differently according to the positions of the sensing units 119a to 119g, the bright place shows a high voltage waveform, and the dark place shows a low voltage waveform.

The voltage waveform generated as described above is removed by turning on the capacitor C1 of the removal unit 120 to remove the DC component (photosensitive waveform due to indoor lighting), and the diode D1 and the capacitor C2 of the removal unit 120 are removed. Through rectification and smoothing, the voltage waveform is output at a constant level.

Then, the voltage waveform of a predetermined level output from the removal unit 120 is input to the A / D converter 121 is converted into a digital signal, the converted digital signal is input to the digital convergence control unit 114, The input signal is stored in the memory 122 as a reference value.

Therefore, when a consumer wants to automatically correct a distorted convergence while watching, the pattern is lit vertically / horizontally at each point in the same order as the first step, and the resulting voltage waveform also eliminates the DC level caused by indoor lighting. After a smoothing circuit is performed through the smoothing circuit constituting the removing unit 120, a value changed through the A / D converter 121 is input to the convergence control unit 114 to be stored in the memory 122. Will be compared with

Subsequently, the convergence control unit 114 compares a value input through the A / D converter 121 with a value previously stored in the memory 122 and calculates a corresponding position change if the comparison result value is wrong. A corresponding correction current is output to the convergence yoke 118, thereby restoring the convergence quality in the factory adjusted state.

As described above, the apparatus for adjusting auto convergence of the projection TV according to the present invention has the following effects.

First, instead of calculating the distance by moving the test pattern, it generates a test pattern whose brightness is gradually changed and reflects it at once, and performs convergence correction based on the magnitude of the waveform level according to the luminance change generated according to the position where the pattern covers the sensor. Therefore, the time required for the convergence correction is shortened.

Second, it is possible to eliminate the error caused by removing the DC component generated by the indoor lighting.

Third, the distance measurement irrationality in the conventional interlaced scanning method was improved.

Fourth, the manufacturing cost can be lowered by using only one light sensor.

Claims (4)

A screen for displaying R, G, and B video signals; A test pattern generation unit generating a test pattern having a predetermined size for auto convergence adjustment; A detector for detecting a pattern generated by the test pattern generator; A remover for removing a voltage of a DC component from a sensed value detected by the detector; An A / D converter for converting an analog signal output through the removal unit into a digital signal; A memory for storing a reference value for auto convergence adjustment; And, And a digital convergence unit for outputting a signal such that the convergence is automatically adjusted according to whether the output of the A / D converter and the reference value previously stored in the memory are matched. The method of claim 1, And said sensing unit comprises an optical sensor. The method of claim 1, The test pattern generation unit If you want to do a horizontal test, create a pattern with a gradual change in luminance from left to right. The projection TV's auto-convergence control device, characterized in that to generate a pattern with a gradual change in brightness when the vertical test. The method of claim 1, The removal unit is a capacitor (C1) for removing the DC component of the voltage waveform output from the detection unit; And a diode (D1) and a capacitor (C2) for smoothing the signal output through the capacitor (C1).