CN2896726Y - Convergent dynamic compensation circuit of CRT rear-projection TV set - Google Patents
Convergent dynamic compensation circuit of CRT rear-projection TV set Download PDFInfo
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- CN2896726Y CN2896726Y CN 200620085466 CN200620085466U CN2896726Y CN 2896726 Y CN2896726 Y CN 2896726Y CN 200620085466 CN200620085466 CN 200620085466 CN 200620085466 U CN200620085466 U CN 200620085466U CN 2896726 Y CN2896726 Y CN 2896726Y
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Abstract
A dynamic convergence compensation circuit of a CRT projection TV and shunted on a coupling resistor R1 on the input end of the convergence magnifier comprises an emitter follower taking ABL control signal as input port, the gate limit circuit connected with the emitter follower through resistor R276 and switch control circuit connected with gate limit circuit. The output 1 of switch control circuit transmit blue line compensation signal through the resistor R733 while the output port 4 of the switch control circuit transmit red line compensation control signals through resistor R732. The gate limit circuit is type TA75393P and the switch control circuit is type TC4066B. With proper circuit design, the circuit correspondingly modify the compensation of these three colors so that red, green and blue colors can be convergent when the brightness changes so as to guarantee uniform convergence of pictures under different brightness and improve the display effects of picture colors, and thus it can be widely used for various kinds of projection TV sets.
Description
Technical field
The utility model belongs to the rear-projection TV set technical field, more particularly relates to the improvement of the convergence dynamics compensation circuits of CRT rear-projection TV set.
Background technology
In the CRT projection TV set, imaging system is made up of the redgreenblue projection tube.Three looks overlap and are finished by convergence yoke fully, finally reach satisfied effect.Because the mechanical location difference of three projection tubes, the amplification quantity of three look convergence yokes are also just different.Three pipes order is followed successively by red, green, blue from left to right.Redness is emitting shape from left to right during the under convergence state, so after assembling adjustment, the convergence amplification quantity that needs is also inequality, the right side amplification quantity should be big.Equally, the convergence amplification quantity on the left of blueness is focused at should be big.
General television set can cause that when image generation brightness changes high pressure changes, and high pressure changes the changes in amplitude that then causes image.In order to weaken this variation effect, scanning control chip in the circuit (as TDA9333) carries out reverse compensation (if high pressure changes amplitude is diminished, TDA9333 compensates and makes amplitude suitably become big) to the image line width of cloth.But because this compensation is an equivalent to red, green, blue three looks, and the every as mentioned above capable diverse location convergence amplification quantity of actual conditions is different, therefore can cause the color misconvergence of red, green, blue picture signal.Main phenomenon is: screen right side redness was turned right and is deflected away from when image brightened, and screen left side blueness is turned left and deflected away from.
Summary of the invention
The purpose of this utility model just is to overcome above-mentioned shortcoming and defect, and a kind of convergence dynamics compensation circuits of CRT rear-projection TV set is provided.By reasonable circuit design, corresponding correction is carried out in the compensation of three looks, red, green, blue three looks when changing, image brightness also can be assembled well, guarantee that effectively image in the different bright dark consistency of assembling down, improves the display effect of image color.
In order to achieve the above object, the resistance of a suitable resistance of the utility model dynamically control in parallel is on the build-out resistor R1 that assembles amplifier in.Comprise with the ABL control signal be the emitter follower of input, the threshold circuit that is connected with the emitter of emitter follower through resistance R 726, the ON-OFF control circuit that is connected with threshold circuit.The output 1 of ON-OFF control circuit is through the blue row of resistance R 733 outputs compensating control signal, and the output 4 of ON-OFF control circuit is through the red capable compensating control signal of resistance R 732 outputs.
Threshold circuit is the TA75393P type, and ON-OFF control circuit is the TC4066BP type.
The reason that the color misconvergence phenomenon produces mainly is because picture signal changes the variation that causes high pressure line (ABL): the electron beam rheology is big, the output high pressure step-down of row bag, and the image line amplitude variation is big.TDA9333 makes the image line amplitude variation little by adjusting, and reaches the purpose of image stabilization.Therefore can it be controlled the convergence amplification quantity as control signal by extracting the ABL value.Assemble amplifying signal and have 6 the tunnel, for not being the row of RGB (H) and (V) component.Only need to proofread and correct BH and RH, because redly bluely can deflect away from about 2 pixels when assembling variation.That is to say, when image brightens, the electron beam rheology is big → the capable amplitude variation of high pressure reductions → image raster greatly → make picture signal row amplitude variation little by TDA9333, owing to assemble the amplification quantity difference, cause that the inconsistent redness that causes the screen right side of red or blue shrinkage amplitude deflects away from or the blueness in screen left side deflects away from.Probably can deflect away from 1～2 pixel.
Realize that principle is to assemble the elementary amplification input of power amplifier build-out resistor by changing, thereby reach the minor variations of assembling deflection current.With the blueness is example, by extracting the conducting of control signal control switch, dynamically increases R733 resistance, finally changes amplification quantity.The R733 resistance can be determined according to the effect of test.
The extraction and the control principle of ABL control signal are as follows: extract the ABL control signal from the row bag, in case the ABL line arrives threshold value, make R732/R733 equivalence ground connection by emitter follower control N797, and be connected to the convergence amplifier in respectively.With the blue image is example, when electronic beam current reaches certain numerical value, under the effect of ON-OFF control circuit, the switch of R733 will conducting, R733 forms relation in parallel with the input resistance of amplifying circuit, the actual input impedance of amplifying circuit is diminished, and then the compensation rate of control blue image, make blue image remain on correct position.
The correction principle of red image is the same.The numerical value of R732 and R733 need be determined by the test of many times checking.
As shown in Figure 2, V796 conducting after the effect of ABL control signal is added to N797 behind the switching signal process comparison threshold circuit N794, makes the conducting of N797 internal switch.Signal BH and RH are equivalent to by resistance R 732 and R733 ground connection.Be connected respectively to the input that back level convergence is separately amplified owing to assemble blue red amplification quantity signal BH and RH, input impedance changes like this, is example with the BH signal, and R733 and R1 parallel impedance are changed in input impedance, can minor effect be arranged to the amplification quantity of assembling like this, promptly play compensating action.
Task of the present utility model comes to this and finishes.
The utility model passes through reasonable circuit design, corresponding correction is carried out in compensation to three looks, red, green, blue three looks also can be assembled when image brightness changes well, guarantee that effectively image in the different bright dark consistency of assembling down, improves the display effect of image color.It can be widely used in the various rear-projection TV sets.
Description of drawings
Fig. 1 is a principle schematic of the present utility model.
Fig. 2 is its circuit theory diagrams.
Fig. 3 is for being the aggregation procedure schematic diagram of example with the redness.Redness was emitting shape from left to right when the left side illustrated the under convergence state among the figure.After the right side explanation was assembled and adjusted, the convergence amplification quantity that needs was also inequality, and the amplification quantity in left side should be big.
Embodiment
Embodiment 1.A kind of convergence dynamics compensation circuits of CRT rear-projection TV set is as Fig. 1～shown in Figure 2.This convergence dynamics compensation circuits is connected in parallel on the lotus root of assembling amplifier in and closes on the resistance R 1.Comprise with the ABL control signal be the emitter follower V796 of input, the threshold circuit N794, the ON-OFF control circuit N797 that is connected with threshold circuit N794 that are connected with the emitter of emitter follower V796 through resistance R 726.The output 1 of ON-OFF control circuit N797 is through the blue row of resistance R 733 outputs compensating control signal, and the output 4 of ON-OFF control circuit is through the red capable compensating control signal of resistance R 732 outputs.
Threshold circuit N794 is the TA75393P type, and ON-OFF control circuit N797 is the TC4066BP type.
Among Fig. 1, be the signal of this convergence dynamics compensation circuits in the frame of broken lines (1), for assembling amplifier, it amplifies chip is STK394-250A-E in the frame of broken lines (2).
Embodiment 1 carries out corresponding correction by reasonable circuit design to the compensation of three looks, and red, green, blue three looks also can be assembled when image brightness changes well, guarantees that effectively image in the different bright dark consistency of assembling down, improves the display effect of image color.It can be widely used in the various rear-projection TV sets.
Claims (2)
1. the convergence dynamics compensation circuits of a CRT rear-projection TV set, being connected in parallel on the lotus root of assembling amplifier in closes on the resistance R 1, it is characterized in that comprising with the ABL control signal be the emitter follower of input, the threshold circuit that is connected with the emitter of emitter follower through resistance R 276, the ON-OFF control circuit that is connected with threshold circuit, the output 1 of ON-OFF control circuit is through the blue row of resistance R 733 outputs compensating control signal, and the output 4 of ON-OFF control circuit is through the red capable compensating control signal of resistance R 732 outputs.
2. according to the convergence dynamics compensation circuits of the described CRT rear-projection TV set of claim 1, it is characterized in that said threshold circuit is the TA75393P type, ON-OFF control circuit is the TC4066BP type.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200620085466 CN2896726Y (en) | 2006-06-09 | 2006-06-09 | Convergent dynamic compensation circuit of CRT rear-projection TV set |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200620085466 CN2896726Y (en) | 2006-06-09 | 2006-06-09 | Convergent dynamic compensation circuit of CRT rear-projection TV set |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2896726Y true CN2896726Y (en) | 2007-05-02 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200620085466 Expired - Fee Related CN2896726Y (en) | 2006-06-09 | 2006-06-09 | Convergent dynamic compensation circuit of CRT rear-projection TV set |
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| CN (1) | CN2896726Y (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101399936B (en) * | 2008-10-13 | 2010-07-21 | 深圳创维－Rgb电子有限公司 | Linear compensation circuit for CRT color television |
-
2006
- 2006-06-09 CN CN 200620085466 patent/CN2896726Y/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101399936B (en) * | 2008-10-13 | 2010-07-21 | 深圳创维－Rgb电子有限公司 | Linear compensation circuit for CRT color television |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20070502 Termination date: 20100609 |