KR100228391B1 - Dynamic luminance compensation apparatus - Google Patents

Abstract

The present invention relates to a dynamic luminance compensator for realizing a sharp image quality due to the enlargement, wide angle, and wideness of the CRT by compensating for the luminance reduction around the CRT by a dynamic screen voltage. The brightness of the displayed image is that the electron beam path from the electron gun to the fluorescent surface is longer than the center portion, so that when the electron beam collides with the phosphor, the amount of light emitted is smaller and the periphery of the screen becomes darker than the center portion.

In order to solve the conventional problem, the present invention superimposes a vertical square wave output from a vertical drive amplifier with a horizontal flyback pulse output from a flyback transformer and superimposes the output dynamic luminance compensation voltage on the screen voltage to the screen electrode. Therefore, it is a dynamic luminance compensation device that compensates the luminance of the periphery of the screen to make the overall screen uniform.

Description

Dynamic Luminance Compensator

1 is a block diagram showing a luminance compensator of a conventional CRT.

2 is a view showing the brightness of a conventional CRT.

3 is a diagram showing the linearity in the spectacle or panorama mode of a conventional wide TV.

4 is a block diagram showing a dynamic luminance compensation device of the present invention CRT.

5 is a detailed block circuit diagram of the dynamic luminance compensation device of the present invention.

6 is a dynamic screen voltage waveform diagram of the dynamic luminance compensation device of the present invention.

7 is a block circuit diagram showing another embodiment of the present invention dynamic luminance compensation device.

* Explanation of symbols for main parts of the drawings

11: image chroma deflection processing unit 12: image amplification unit

13: CRT 14: Deflection coil

15: vertical drive amplifier 16: vertical integrator

17: horizontal drive amplifier 18: flyback transformer

19: Horizontal Integrator 20: Adder

21: connection

The present invention relates to a dynamic luminance compensator for realizing a sharp image quality due to the enlargement, wide angle, and wideness of the CRT by compensating for the luminance reduction around the CRT by a dynamic screen voltage.

As shown in FIG. 1, a conventional CRT tube amplifies an RGB image signal output from an RGB image signal and a horizontal / vertical drive signal, and an RGB image signal outputted from the image chroma deflection processor 1. (3) an image amplifier (2) applied to the RGB cathode electrode, and a vertical drive amplifier for receiving the vertical drive signal (V) and amplifying and outputting a vertical deflection current to the deflection coil (4) of the CRT (3). (5) and the horizontal drive amplifying unit 6 which receives the horizontal drive signal H and switches the current amplification to amplify and output the horizontal deflection current to the deflection coil 4 and simultaneously to the flyback transformer 7. In response to the amplified output signal from the horizontal drive amplifier 6, the screen voltage for controlling the beam brightness of the CRT 3, the focus voltage for adjusting the image focus, the high pressure impinging on the phosphor surface of the CRT 3Is composed of a flyback transformer (7) applied to the screen electrode, a focus electrode and an anode electrode of the cathode-ray tube exchanger (3).

As shown in FIG. 1, in the conventional CRT luminance compensator configured as described above, first, when the RGB image signal and the horizontal / vertical drive signal are output from the image chroma deflection processing unit 1, the image amplifier 2 outputs the RGB image signal. Receives and amplifies and outputs the RGB cathode of the cathode ray tube 3.

At this time, the vertical drive signal V output from the image chroma deflection processing unit 1 is amplified and output from the vertical drive amplifier 5 to apply a vertical deflection current from the deflection coil 4 of the CRT 3 and simultaneously drive the horizontal drive. The signal H is input to the horizontal drive amplifying unit 6 and switched on the current amplification, and then a horizontal deflection current is applied to the deflection coil 4 so that the deflection coil 4 deflects the electron beam in the vertical / horizontal direction.

On the other hand, when the horizontal deflection current amplified and output from the horizontal drive amplifier 6 is applied to the deflection coil 4 and simultaneously to the flyback transformer 7, the flyback transformer 7 is applied to the RGB cathode electrode. By accelerating the electron beam generated according to the image signal, the screen voltage is output to the screen electrode so that the beam brightness of the CRT 3 is controlled, and the focused electron beam is focused to accurately adjust the focus of the image appearing on the CRT 3. The high voltage is output to the anode electrode while the focus voltage is output to the electrode so that the image is displayed on the CRT 3.

However, in the conventional CRT, the brightness of the displayed image is longer than the center portion of the electron beam path from the electron gun to the fluorescent surface. Therefore, when the electron beam collides with the phosphor, the amount of light emitted is smaller so that the peripheral portion is darker than the center portion. there was.

That is, in the case of 29-inch large CRT, the brightness of the screen is 50% -70% lower than that of the center part, and 33% of the CRT is horizontally enlarged by 33% horizontally than the CRT. Likewise, the image brightness of the left and right points B and C is darker than the center portion A, and the brightness of the C tube edges E, F, I, and H is darker.

In this case, wide TVs with wide CRTs (16: 9) should be able to watch the screen naturally when the 4: 3 screen is increased to 16: 9 wide screen. As shown in FIG. (J → N) A wider spectacle or panorama mode is used, but this has a problem in that the number of collisions of the electron beams per unit area is larger in the center part and decreases toward the periphery part so that the brightness of the periphery is darker than the center part.

In order to solve the conventional problem, the present invention superimposes a vertical square wave output from the vertical drive amplifier and a horizontal flyback pulse output from the flyback transformer and superimposes the dynamic luminance compensation voltage output on the screen voltage to the screen electrode. Therefore, the brightness of the screen peripheral portion is compensated for to make the overall screen uniformity. The configuration and effect of the present invention will be described with reference to the accompanying drawings.

As shown in FIGS. 4 and 5, the dynamic luminance compensation device of the CRT of the present invention includes an image chroma deflection processing unit 11 for outputting an RGB image signal and a horizontal / vertical drive signal (H / V), and an output RGB. The image amplifier 12 amplifies the image signal and applies it to the RBG cathode electrode of the CRT 13, and receives the vertical drive signal V and amplifies it so as to vertically deflect the deflection coil 14 of the CRT 13. The vertical drive amplifier 15 for applying current and the vertical square wave 16 outputted at the same time when the vertical deflection current is simultaneously outputted from the vertical drive amplifier 15 receives the vertical integral part 16 for outputting the vertical parabola wave. And a horizontal drive amplifying unit 17 which receives the horizontal drive signal H, switches the same, applies a horizontal deflection current to the deflection coil 14, and simultaneously applies a horizontal current to the flyback transformer 18. Prize The horizontal integrating unit 19 which receives a horizontal deflection current amplified by the horizontal drive amplifier 17 and applies a voltage to the anode electrode, the focus electrode, and the screen electrode of the CRT 13 and simultaneously outputs a horizontal flyback pulse wave. And an adder 20 for synthesizing the parabola waves integrally output from the vertical / horizontal integral parts 16 and 19 and outputting a dynamic luminance compensation voltage, and overlapping with the screen voltage output from the adder 20. 15A is a vertical output IC, 16A is a first amplifier, 16B is a first integrator, 16C is a second amplifier, and 16D is a second integrator. Q1-Q5 is a transistor. D1-D10 is a diode, C1-C12 is a capacitor, and R1-R25 is a resistor. L1-L3 is the coil, T1 is the transformer, NP is the primary winding, and NS1-NS9 is the secondary winding.

As shown in FIG. 4 and FIG. 5, when the RGB image signal and the horizontal / vertical drive signal are output from the image chroma deflection processing unit 11, the image amplification unit 2 outputs the RGB. The video signal is input and amplified and output to the RGB cathode electrode of the CRT (3).

At this time, the vertical drive signal v output from the image chroma deflection processing unit 11 is amplified and output from the vertical drive amplifier 15 so as to apply a vertical deflection current to the deflection coil 14 of the CRT. The vertical square wave output from the vertical drive amplifier 15 is applied to the vertical integrator 16 at the same time.

That is, the vertical drive sawtooth wave is output from the image chroma deflection processing unit 11 and input to the non-inverting input terminal e of the vertical output IC 15A through the resistor R18 in the vertical drive amplifying unit 15 and the reference direct current. The voltage is divided against the resistors R20 and R21 and input to the inverting input terminal d.

Therefore, the voltage amplified by the vertical output IC 15A is applied to the vertical deflection coil L3 through the output terminal b so that the vertical deflection current flows, and the sawtooth wave output current is detected by the resistor R16. The negative feedback signal is combined with the vertical drive sawtooth wave input through the resistor R17 to the resistor R18.

Thereafter, when a voltage is amplified and output from the vertical output IC 15A, a vertical square wave is generated in the pump-up circuit inside the vertical output IC 15A.

At this time, the pump-up pulse of the vertical square wave is combined with the power supply terminal f + Vcc by the capacitor C11 and the diode D10 and acts on the power output terminal c.

Accordingly, the vertical square wave output from the vertical square wave output terminal g is applied to the first amplifier 16A including the resistors R3 and R4 and the transistor Q2 in the vertical integrating unit 16, thereby providing the resistors R2 and R4. ) Is applied to the first amplifier 16A including the transistor Q2 and is divided by the resistors R3 and R4 and then applied to the base of the transistor Q2 to be amplified and output.

When the amplified output signal is integrated in the first integrator 16B including the resistor R5 and the capacitor C7 and the vertical sawtooth wave is output, the second amplifier 16C including the resistor R6-R8 and the transistor Q3 is By receiving the vertical sawtooth wave and amplifying it and applying it to the second integrator 16D including the resistors R10 and R11, the capacitor C8, and the transistor Q4, the second integrator 16D integrates the amplified output sawtooth wave. To output vertical parabolic waves.

On the other hand, the horizontal drive signal H output from the image chroma deflection processing unit 11 is input to the horizontal drive amplifier 17 and the current amplified switch is applied to the deflection coil 4 to apply a horizontal deflection current to the electron beam in the horizontal direction. And a horizontal deflection current amplified and output from the horizontal drive amplifier 17 is applied to the flyback transformer 18 so that the anode of the cathode tube according to the RGB image signal applied to the RGB cathode electrode of the cathode ray tube 13 is A horizontal flyback pulse wave is output while applying voltage to the electrode, screen electrode and focus electrode.

That is, the horizontal drive pulses output from the image chroma deflection processing unit 11 are applied to the base of the transistor Q1 in the horizontal drive amplifier 17 to switch the transistor Q1 and the diode D1 during the horizontal scanning period. By applying a horizontal deflection current to the horizontal deflection coil (L1) by performing a horizontal S-shaped correction by the series resonant current of the horizontal deflection coil (L1) and condenser (C1).

At this time, during the horizontal retrace period, the transistor Q1 is formed by the resonant resonance of the inductance LP and the horizontal deflection coil L1 in parallel with the inductance LP of the primary winding NP of the flyback transformer 18. The flyback pulses are generated in the collector, and the voltage becomes the primary winding voltage of the flyback transformer 18.

Therefore, after superimposing the voltage generated in the primary windings NS1-NS6 of the flyback transformer 18, a high voltage is applied to the anode electrode of the CRT 13,

The voltage generated in the secondary windings NS1-NS2 is rectified and superimposed by the diodes D2 and D3 so that the focus voltage and the screen voltage are applied to the focus electrode and the screen electrode of the flyback transformer 13, respectively.

On the other hand, the flyback pulse voltage generated in the secondary windings NS7-NS8 of the flyback transformer 18 is rectified and smoothed by the diodes D8 and D9 and the capacitors C3 and C4 so that each DC voltage is a vertical drive amplifier. The inverse flyback pulses generated at the secondary output windings NS7 and supplied to the power supply terminals a and f of the vertical output IC 15A in the coil 15 are coil L2, condenser C5, and transformer T1. It is applied to the horizontal integrating portion 19 consisting of the primary side winding (NP) of the horizontal parabolic voltage of the horizontal period is generated.

As such, when the vertical / horizontal parabola voltages are output from the vertical integrator 16 and the horizontal integrator 19, the adder 20 synthesizes the input vertical / horizontal periodic parabola voltages to compensate for the dynamic luminance as shown in FIG. When the voltage is generated, the connection unit 21 connects the dynamic luminance compensation voltage to DC and superimposes the AC waveform voltage on the screen voltage output from the flyback transformer 18 to the screen electrode of the CRT.

That is, the vertical period parabola voltage output from the vertical integrator 16 is applied to the third amplifier 20A made up of the resistors R12-R14 transistor Q5 in the adder 20 and amplified and outputted. Through the applied to the start point (S) of the secondary winding (NS) of the transformer (T1) of the vertical integrator 16 through the synthesized with the vertical periodic parabola voltage boosted by the transformer (T1) outputs a dynamic luminance compensation voltage Let's do it.

Accordingly, the dynamic luminance compensation voltage synthesized and output by the adder 20 is applied to the connection portion 21 formed of the resistor R1 capacitor 12 to be DC-coupled, and then the screen voltage output from the flyback transformer 18. By superimposing on the screen electrode of the CRT 13, a parabolic voltage in the form of horizontal and vertical periods is applied to the screen electrode of the CRT 13 so that the horizontal period is gradually moved to the periphery of the screen of the CRT 13. It takes high, and the vertical period is also high toward the peripheral circumference to accelerate the electron beam of the horizontal and vertical periphery, thereby brightly compensating the periphery, thereby compensating the brightness of the horizontal / vertical periphery to the center, thereby making the screen of the CRT 13 uniform throughout. Keep the brightness

On the other hand, Figure 7 is another embodiment of the dynamic luminance correction device of the present invention CRT,

The parabolic voltage of the horizontal / vertical period is applied to the anode electrode of the CRT 13 by receiving the dynamic luminance compensation voltage synthesized and output from the adder 20 and overlapping the high voltage output from the flyback transformer 18. The higher the voltage is supplied to the parabola phase toward the periphery of the screen, the phosphor collision energy of the electron beam is increased to the periphery of the screen to compensate for the luminance of the periphery.

As described above, the vertical square wave output from the vertical drive amplifier is overlapped with the horizontal flyback pulse output from the flyback transformer, and the dynamic luminance compensation voltage superimposed on the screen voltage is applied to the screen electrode, thereby increasing the luminance of the peripheral portion of the screen. By compensating for the overall brightness of the screen is uniform, there is an effect that can display a clear image quality.

Claims (4)

An image chroma deflection processing unit for outputting an RGB image signal and a horizontal / vertical drive signal, an image amplification unit for amplifying an RGB image signal output from the image chroma deflection processing unit, and applying it to an RGB cathode electrode of a CRT, and the vertical drive signal ( A vertical drive amplifier for amplifying and outputting a vertical deflection current to the deflection coil of the CRT and V), and amplifying and outputting a horizontal deflection current to the deflection coil at the same time by receiving the horizontal drive signal (H). A horizontal drive amplifier applied to the transformer, a screen voltage for controlling the beam brightness of the CRT by receiving the amplified output signal from the horizontal drive amplifier, a focus voltage for adjusting image focus, and a high pressure impinging on the phosphor surface of the CRT Flyback applied to the screen electrode, focus electrode and anode electrode of the CRT In the CRT luminance compensator comprising a transformer, a vertical integrating unit (16) for receiving a vertical square wave simultaneously outputted at the time of amplifying output from the vertical drive amplifier (15) and integrating it to output a vertical parabola wave; A horizontal integrator 19 for receiving a horizontal flyback pulse wave output from the flyback transformer 18 and integrating it to output a horizontal parabola wave, and an integrator in the vertical / horizontal integrator 16 and 19. An adder 20 for synthesizing the output parabola wave and outputting a dynamic luminance compensation voltage and a dynamic luminance compensation voltage output from the adder 20 are superimposed on the screen voltage output from the flyback transformer 18. Dynamic luminance compensation device, characterized in that consisting of a connecting portion (21). The coil L2 and the condenser C5 of claim 1, wherein the horizontal integrator 19 receives a reverse flyback pulse generated from the secondary winding NS7 of the flyback transformer 18 to output a horizontal parabola voltage. And a transformer (T1). The vertical integrating unit 16 of claim 1, wherein the vertical integrating unit 16 divides the input vertical square wave into a first amplifier 16A including resistors R3 and R4 and a transistor Q2, and amplifies and outputs the vertical square wave. A first integrator 16B composed of a resistor R5 and a capacitor C7 integrated and outputting a vertical sawtooth wave; a second amplifier 16C amplifying the integrated output sawtooth wave and applying it to a second integrator 16D; And a second integrator (16D) comprising a resistor (R10) (R11) and a capacitor (C8) for integrating the amplified output vertical sawtooth wave to output a vertical parabola wave. The method of claim 1, wherein the dynamic luminance compensation voltage added by the adder 20 is superimposed on the anode high voltage output from the flyback transformer 18 to be input to the anode electrode of the CRT 13. Dynamic luminance compensator.