KR0141119B1 - Luminance compensation circuit - Google Patents

Abstract

The present invention relates to a luminance and gradation correction circuit of a cathode ray tube display device using a dynamic focus signal, and comprises a video signal amplifier, a luminance and gradation correction means, a luminance signal output unit, and an image signal output unit. The gradation can be corrected at the same time. Accordingly, in the large-screen display device, uniform luminance and gradation signals appear at the center as well as the edge of the screen, thereby obtaining clear image quality. The present invention can also be used in cathode ray tube display devices or general display devices, and is particularly useful for large screen display devices and flat screens.

Description

Brightness and gradation correction circuit of cathode ray tube display device

1 is a block diagram showing an embodiment of a luminance and gray scale correction circuit of a cathode ray tube display device according to the present invention;

2 is a detailed circuit diagram according to FIG. 1;

3 is a cross-sectional view of the cathode ray tube without dynamic focusing,

(A) and (b) of FIG. 4 are characteristic charts showing the phases before and after the correction of the luminance and the gradation signals;

5 is a waveform diagram showing an input state of a dynamic poker signal according to FIG.

(A)-(d) of FIG. 6 are the waveform diagrams shown to (a) and (b) of FIG.

* Explanation of symbols for important parts of the drawings

11: Dynamic focus signal input terminal

10: dynamic focus signal input unit

20: luminance and gradation correction signal generator

30A: luminance signal synthesizing unit 30B: gradation correction signal synthesizing unit

31: External luminance adjustment signal input terminal

40: reference luminance signal adjusting unit 50: luminance signal amplifying unit

60: luminance signal output unit 70: video signal amplification unit

71: video signal input terminal 80: video signal output unit

90: cathode ray tube V _CC , V _DD : constant voltage source

R1 to R24: resistance VR1 to VR3: variable resistance

C1 to C6: Capacitor Q1 to Q7: Transistor

L1-L3: Coil D1-D5: Diode

A1: Amplifier A: Luminance and gradation correction means

The present invention relates to a video signal correction circuit of a cathode ray tube display device. More particularly, the luminance and gradation of a cathode ray tube display device are corrected by using a dynamic focus signal so that the brightness of the entire cathode ray tube display device is made uniform. And a gradation correction circuit.

As the current display device has a large screen resolution, that is, a screen size gradually increases and pixels are gradually enlarged, the distance of the focus signal reaching the flat screen is not constant according to the conventional display technology. There was a problem in that the luminance and gradation appeared distinctly only in the center of the screen, and the luminance and gradation fell toward the edge of the screen.

In addition, in the conventional luminance and gray level correction circuit, a luminance correction parabola signal generator is used to correct luminance, and a tone correction parabola signal generator is used to correct the gray scale. As a result, each parabola signal generator must be installed to correct luminance and gradation, which results in an increase in the volume of the set. In addition, there was a hassle to adjust the integer value of the parabola signal generator in order to correct the brightness and the gray scale. The brightness and the gray scale are not precisely corrected according to the size and deflection angle of the screen with the integer values of the same parts. There was a problem that a difference in image quality occurs between the edges.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to correct luminance and gradation by using a dynamic focus signal, thereby adjusting luminance and gradation using only dynamic focusing adjustment values without adjusting a separate luminance and gradation correction amount. The present invention provides a luminance and gradation correction circuit of a cathode ray tube display device capable of performing the same time to uniformize the luminance and gradation of the entire screen.

A characteristic of the luminance and gray scale correction circuit of the cathode ray tube display apparatus according to the present invention for achieving the above object is a video signal amplifying unit for amplifying the image signal input from the video signal input multi-function, and performing the luminance and gray scale correction A luminance signal output unit for receiving luminance and gradation correction means, a luminance and gradation correction signal outputted from the luminance and gradation correction means, and combining the image signal with an image signal to output the image signal output unit, the image signal amplifier and the luminance signal output unit A luminance and tone correction circuit of a cathode ray tube display device comprising a video signal output unit for applying a negative output as an input to a cathode end of a cathode ray tube; The luminance and gradation correction means generates and outputs an appropriate luminance and gradation correction sinhol using a dynamic focus signal input from a dynamic focus signal input terminal, and outputs the gradation correction signal through the gradation correction signal synthesizing unit. It is provided to the amplification unit, and the external luminance adjustment signal inputted from the external luminance adjustment signal input terminal to synthesize the luminance correction signal and the reference luminance signal to output to the luminance signal output unit.

Hereinafter, a preferred embodiment of a luminance and gray scale correction circuit of a cathode ray tube display device according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of a luminance and gray scale correction circuit of a cathode ray tube display device.

The video signal input from the video signal input terminal 71 is amplified by the video signal amplifier 70 and is sent to the video signal output unit 80.

The video signal output unit 80 outputs the amplified video signal to the cathode end of the cathode ray tube 90.

In addition, the dynamic focus signal input from the dynamic focus signal input terminal 11 is input to the dynamic focus signal input section 10, and this signal is sent to the luminance and gradation correction signal generator 20. At this time, the brightness correction signal and the tone correction signal generated by the brightness and tone correction signal generator 20 are input to the brightness signal synthesis unit 30A and the tone correction signal synthesis unit 30B, respectively.

At this time, the gradation correction signal inputted to the gradation correction signal synthesizing unit 30B is transferred to the image signal amplifying unit 70 and amplified. In addition, the luminance correction signal input to the luminance signal synthesizing unit 30A is input from the external luminance adjustment signal input from the external luminance adjustment signal input terminal 31 and from the reference luminance signal adjusting unit 40 for adjusting the reference luminance signal. Combined with the reference luminance adjustment signal.

The synthesized signal is produced by the amplification process of the luminance signal amplification unit 50, and a luminance correction signal of an appropriate size is generated, and the signal is sent to the image signal output unit 80 through the luminance signal output unit 60. .

FIG. 2 is a detailed circuit diagram of the luminance and gray level correction circuit of the cathode ray tube display device of FIG.

The dynamic focus signal input terminal 11 is connected to the dynamic focus signal input unit 91 including the condenser C1 and the resistor R1, and the output of the dynamic focus signal input unit 10 is a luminance and gradation correction signal generator ( 20) is entered.

The luminance and the correction signal generating section 20 to control the constant voltage source (V _CC), and a constant voltage source resistor (R2, R3) operable to distribute a constant voltage generated from the (V _CC) and the luminance and tone correction signal The variable resistors VR1 and VR2 and the input of the luminance and gray level correction signal generator 20 are connected to the base, the collector is connected to the constant voltage source V _CC , and the emitters are the respective variable resistors VR1 and VR2. And a transistor Q1 connected thereto.

In addition, the luminance and gradation correction signals adjusted by the variable resistors VR1 and VR2 are input to the luminance signal synthesizing unit 30A and the gradation correction signal synthesizing unit 30B.

In addition, the luminance correction signal output from the luminance and gradation correction signal generator 920 is input to the luminance signal synthesizing unit 30A. The luminance signal synthesizing unit 30A includes an amplifier A1 and a plurality of resistors. And a noise canceling section consisting of (R6, R7) and a condenser (C3), a plurality of resistors (R4, R5), and an external luminance signal input terminal for inputting an external luminance adjustment signal, and a variable resistor (VR3). ) And a plurality of resistors R10 and R11 are connected to the output terminal of the reference luminance signal adjusting unit 10.

In addition, the synthesized signal output from the luminance signal synthesizing unit 30A includes a constant voltage source V _DD , transistors Q2 and Q3 for amplifying, and a plurality of resistors R12-R16. It is entered as 50.

In addition, the luminance correction signal amplified by the luminance signal amplifying unit 50 is input to the luminance signal output unit 60 composed of a plurality of diodes D1 to D3.

On the other hand, the gradation correction signal output from the luminance and gradation correction signal generator 20 is composed of a gradation correction signal composed of a constant voltage source V _CC , a coil L1, a capacitor C4, and a resistor R8, R9. It is applied to the part 30B.

In addition, the synthesized newlywed constant voltage source V _DD , the plurality of resistors R17 to R22, the coils L2 and L3, the diodes D4 and D5, And a condenser C5 and a plurality of transistors Q4 to Q7, which are input to the image signal amplifier 70 connected to the image signal input terminal 71 to which the image signal is input.

In addition, the signal amplified by the video signal amplifier 70 is input to the video signal output unit 80 composed of a plurality of resistors (R23, R24) and a capacitor (C6).

In addition, the video signal output from the video signal output unit 80 is applied to the cathode end of the cathode ray tube (90).

Referring to the circuit configured as described above, the dynamic focus signal input from the dynamic focus signal input terminal 11 (refer to (a) and (b) of FIG. 5) is a dynamic focus signal input unit ( 10) The straight component is removed through the process.

In addition, the transistors Q1, the resistors R2 and R3, and the variable resistors VR1 and VR2 of the luminance and gray level correction signal generator 20 serve as buffers.

Here, the variable resistor VR1 is adjusted to make an appropriate magnitude and gray level correction waveform, and the variable resistor VR2 is adjusted to make an appropriate magnitude luminance correction waveform.

In addition, the luminance signal synthesizing unit 30A synthesizes the luminance correction signal 롸 external luminance adjustment signal and the luminance adjustment signal generated by the reference luminance signal adjusting unit 40, and noise composed of the resistors R6 and R7 and the capacitor C3. The noise is removed through the elimination section to generate an appropriate luminance correction signal (see (c) of FIG. 6).

In addition, the variable resistor VR3 and the resistor R10 of the reference luminance signal adjusting unit 40 serve to adjust the reference luminance signal, and the constant voltage generated from the constant voltage source V _CC adjusts the variable resistor VR3. The reference resistance level of the entire screen is determined using this variable resistance value.

In addition, the transistors Q2 and Q3 and the resistors R12 to R16 in the luminance signal amplifying unit 50 constitute a two-stage equalizer and function to amplify the luminance signal.

In addition, the diode D1 in the luminance signal output unit 60 functions to combine the luminance signal and the image signal, and the diodes D62 and D63 absorb the surge voltage to the cathode of the cathode ray tube. It acts to pass to ground when overvoltage occurs.

On the other hand, the gradation correction signal synthesizing unit 30B applies the gradation correction signal to the image signal amplifying unit 70, and the transistor Q4 determined by the constant voltage source V _CC , the coil L1, and the resistors R8 and R9. DC voltage applied to the base of < RTI ID = 0.0 >) and < / RTI > the gradation correction signal adjusted by the variable resistor VR1 in the luminance and gradation correction signal generator 20 are synthesized by the cone line C4 (Fig. 6 (c)). Reference).

In this case, when the gradation correction is not performed, the light resistance does not operate because the transistor Q1 is turned off. Therefore, a constant DC voltage is applied to the transistor Q4.

When the gradation is corrected, the video signal amplifier 70 is composed of transistors Q4 to Q7, resistors R17 to R22, capacitors C5, diodes D4 and D5, and coils L2 and L3. The video signal input from the video signal input terminal 71 is appropriately amplified by the gradation correction signal applied to the base of the transistor Q4.

In addition, the capacitors C6 and the low phases R23 and R24 of the video signal output unit 80 apply the grayscale corrected video signal and the luminance-preserved luminance signal (see FIG. 6 (d)) to the cathode end of the cathode ray tube. do.

3 shows the focus state reaching the flat screen from the cathode ray tube without dynamic focusing.

(A) of FIG. 4 is a luminance and gradation characteristic diagram appearing on the screen without luminance and gradation correction, and (b) is a luminance and gradation characteristic diagram appearing on the screen with luminance and gradation correction.

5 is a characteristic diagram of a dynamic focus signal, and shows well the horizontal and vertical characteristics.

As described above, according to the luminance and gradation correction circuit of the cathode ray tube display device according to the present invention, the luminance and gradation of the entire screen are simultaneously corrected and uniformed, so that a clear picture quality can be obtained when using a general display device, especially a large display device. Can be.

This is especially useful for projection display devices using cathode ray tubes.

Claims (2)

In the video signal amplifying unit 70 for amplifying the video signal input from the video signal input terminal 71, luminance and gradation correction means A for performing luminance and gradation correction, and in the luminance and maintenance means A A luminance signal output unit 60 for receiving the output luminance and gray level correction signals and outputting them to the image signal output unit 80, and an output of the image signal amplifying unit 70 and the luminance signal output unit 60 as inputs. The cathode ray tube display device comprising a video signal output unit 80 applied to the cathode end of the cathode ray tube 90 is a luminance and gradation preservation circuit, and the luminance and gradation correction means A is a dynamic focus signal input terminal. 11 generates and outputs an appropriate luminance and gradation correction signal using the dynamic focus signal inputted from 11), and outputs the gradation correction signal to the image signal amplifying unit 70 through the gradation correction signal synthesizing unit 30B. External brightness Jeongsinho adjust the external brightness is input from the input terminal 31 signal rwa luminance correction signal and the reference signal and the bent composite to the luminance signal output unit 60, cathode ray tube display device, the luminance and tone correction circuit of the output, characterized in that a. The dynamic focus signal input unit of claim 1, wherein the luminance and gradation correction means A receives the dynamic focus signal from the dynamic focus signal input terminal 11 and outputs the dynamic focus signal to the luminance and gradation correction signal generator 20. 10); A luminance and gradation correction signal generator 20 which receives the signal output from the dynamic poker signal input unit 10 and generates an appropriate luminance and gradation correction signal; A gradation correction signal synthesizing unit 30B for synthesizing the gradation correction signals output from the luminance and gradation correction signal generating unit 20 and applying them to the image signal amplifying unit 70; The luminance correction signal output from the luminance and gradation correction signal generator 20, the external luminance adjustment signal input from the external luminance adjustment signal input terminal 31, and the existing luminance adjustment output from the reference luminance signal adjustment unit 40. A luminance signal synthesizing unit 30A for synthesizing the signals, and a luminance signal amplifying unit 50 for receiving and amplifying the synthesized signal output from the luminance signal synthesizing unit 30A and outputting the amplified signal to the luminance signal output unit 60. Brightness and gradation correction circuit of cathode ray tube display device.