KR19980014559A - A display device having a vertical distortion correction circuit - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image distortion correction circuit for correcting an image to be displayed to be distorted upward or downward.

A correction position adjuster for adjusting an output position of a horizontal signal by adjusting a width of an output duty pulse of the horizontal output circuit; and a variable gain amplifier for variably amplifying a voltage of a horizontal signal whose output position is adjusted by the correction position adjuster, A correction size adjuster for adjusting an output size of the horizontal signal, a horizontal output signal whose output position and output size are adjusted by the correction position adjuster and the correction magnitude adjuster, to a primary coil, And a modulation circuit for receiving a vertical output signal at one end and superimposing the horizontal output signal and the vertical output signal and transmitting the superposed horizontal output signal and the vertical output signal to a vertical deflection coil connected to a secondary coil. The voltage of the position-corrected signal is variably amplified to adjust the correction size, and then the corrected horizontal output signal A has the effect that can be superimposed to the vertical output signal to correct the applied By the upper and the lower image distortion in the vertical deflection coil by using the E-I transformer.

Description

A display device having an image distortion correction circuit

In particular, the present invention relates to a correction circuit for an image that is distorted upward and downward. In particular, the correction position is adjusted by varying the width of the duty pulse of the horizontal output signal, the voltage of the position- And a correction circuit for correcting the distorted image by applying the corrected horizontal output signal to the vertical deflection coil by superimposing the vertical output signal on the vertical output signal using an EI transformer.

1 is a block diagram showing an internal circuit of a general display device. As shown in the figure, the computer 10 includes a CPU 11 for receiving and processing a keyboard signal used by a user and generating data according to a processed result, and a CPU 11 for receiving data output from the computer 11, (H-SYNC) for synchronizing the processed video signals R, G, and B with the video signals R, G, and B, and a vertical synchronizing signal And a video card 12 for outputting a V-SYNC signal.

The monitor 20 includes a microcomputer 21 for receiving a horizontal synchronizing signal H-SYNC and a vertical synchronizing signal V-SYNC from the video card 12 and a microcomputer 21 for generating a screen control signal for controlling the monitor screen A horizontal and vertical output circuit 23 for synchronizing a monitor screen control signal outputted from the microcomputer 21 and a raster by receiving a reference oscillation signal, A video circuit section 24 for receiving and displaying a video signal outputted from the card 11 and a video signal processing section 24 for supplying a driving voltage to the microcomputer 21 and the horizontal and vertical output circuit section 23 and the video signal processing section 24 And serves as a power supply circuit unit 25.

Each block in the monitor 20 having such a configuration will be described in more detail as follows.

The microcomputer 21 receives the horizontal synchronizing signal H-SYNC and the vertical synchronizing signal V-SYNC output from the video card 12. [ The microcomputer 21 receiving the horizontal synchronizing signal H-SYNC and the vertical synchronizing signal V-SYNC incorporates various monitor screen control data. When a monitor screen control signal is applied to the microcomputer 21 by the control button section 22, the microcomputer 21 outputs a phase adjustment signal for adjusting an image displayed on the monitor screen in accordance with the screen control signal do.

The microcomputer 21 outputs a phase adjustment signal and a reference oscillation signal in accordance with the monitor screen control signal. The reference oscillation signal output from the microcomputer 21 is applied to the horizontal and vertical oscillation signal processor 23-1.

The horizontal and vertical oscillation signal processor 23-1 outputs the switching speed of the on / off operation of the sawtooth wave generating circuit in accordance with the horizontal synchronizing signal H-SYNC and the vertical synchronizing signal V-SYNC transmitted from the video card 11, . The vertical pulse output from the horizontal and vertical oscillation signal processor 23-1 is applied to the vertical drive circuit 23-2. The vertical drive circuit 23-2, to which the vertical oscillation signal is applied, generally uses one stage of the vertical amplification type. The emitter follower 23-2 applies an input to the base terminal of the transistor and extracts an output voltage from the emitter terminal. The mold is used a lot. Therefore, the linearity improving operation is performed rather than the gain. The vertical output circuit 23-3 receiving the current signal output from the vertical drive circuit 23-2 outputs a sawtooth current corresponding to the vertical sync pulse flowing through the vertical deflection coil 23-6 And the vertical scanning period is determined accordingly.

The horizontal drive circuit 23-5 receiving the horizontal oscillation signal output from the horizontal and vertical oscillation signal processor 23-1 supplies a sufficient current for turning on / off the horizontal output circuit 23-4 do. The horizontal output circuit 23-4 generates a sawtooth current in the horizontal deflection coil 23-7. The horizontal scanning period is determined by the sawtooth current.

Then, a retrace collector is used through a flyback transformer (FBT) 23-9 to supply a stable direct current (DC) voltage to the anode terminal of the CRT 24-4, Using the inductance and the harmonics due to the distribution capacity of the high-voltage circuit 23-8, a large high voltage is generated even when the collector pulse is small, and the high voltage is applied to the anode terminal of the CRT.

The OSD unit 24-1 generates and outputs the OSD gain signal according to the screen control through the microcomputer 21. [ The video preamplifier 24-2, which receives the OSD gain signal output from the OSD unit 24-1 and the video signals R, G, and B applied from the video card 12, (R, G, B) are amplified to maintain a constant voltage level. The video output amplifier 24-3 amplifies the signal amplified by the video pre-amplifier 24-2 with a signal of 40 to 60 VPP, and supplies energy to each pixel. The video signal amplified by the video output amplifier 24-3 is applied to the cathode of the CRT and the video signals R, G, and B are displayed on the monitor screen.

On the other hand, an alternating current (hereinafter referred to as AC) is inputted through the AC input terminal 25-1 of the power supply circuit part 25 for supplying a driving voltage for displaying the video signals R, G and B through a monitor screen The received degaussing coil 25-2 operates to restore the blurring state of the color generated due to the magnetic field purity or the external condition of the monitor screen to the original color. When an alternating current is applied to the degaussing coil 25-2 instantaneously for 2 to 8 seconds in order to perform such operation, the magnetic field formed in the shadow mask in the monitor is disturbed to recover the color blurring state.

The alternating current outputted through the AC rectifier 25-3 is applied to the switching transformer 25-4 and the switching transformer 25-4 performs the switching operation to output the AC output through the voltage output terminal 25-5 to the monitor 20 And supplies various driving voltages required in the driving circuit. At this time, if the horizontal sync signal H-SYNC is not applied from the video card 12, the microcomputer 21 applies a suspend mode signal to the voltage regulator 25-6 to cut off the deflection voltage.

At this time, the square wave pulse output from the pulse width modulation (PWM) unit 25-7 causes the switching device to perform the ON / OFF drive operation, and the change of the pulse width may increase or decrease the conduction time Thereby stabilizing the output voltage. The PWM unit 25-7 receives a power off mode signal from the microcomputer 21 and blocks the voltage supplied to the monitor 20. Thus, the power consumed in the monitor 20 is saved.

Such a display device has an electron gun that emits an electron beam to be scanned on a screen, and the emitted electron beam is scanned laterally in the screen, and an image is formed according to the concentration of the electron beam to be scanned. Since the electron beam is deflected by the electromagnetic field formed by the deflection yoke, the deflection angle of the electron beam can be deformed when the electromagnetic field is affected by the disturbance.

Also, the displayed image may represent a modified image as shown in Figs. 2A to 2B due to an internal or external factor. In addition to the phenomenon of image rotation due to an external magnetic field, the scanning of the electron beam is abnormally performed by the resistance value of the aberration itself, so that the image is formed asymmetrically in the horizontal or vertical direction, or the current applied to the deflection yoke is excessively supplied The image is not displayed in a rectangular shape but has a top-bottom and left-right unevenness formation, resulting in a problem that the image is displayed in a non-rectangular form.

First, the phenomenon as shown in FIG. 2A is referred to as a side pin cushion. This phenomenon occurs when a horizontal deflection output voltage is changed to a variable resistance by using a pin cushion correction circuit (not shown) It is possible to solve this problem. That is, the sawtooth voltage supplied from the vertical circuit is supplied to the pin cushion correction circuit by the parabolic voltage through the integrating circuit, and superimposed on the horizontal output circuit, so that the amount to be corrected and the point to be corrected can be adjusted.

On the other hand, as shown in Fig. 2B, due to the distortion caused by the pulling out of the parabolic waveform due to the RC charging / discharging time constant by the sawtooth wave oscillation output, the distortion due to the nonlinearity characteristic of the transistor or the distortion due to the output transformer, The correction of the phenomenon in which the image appears distorted has a non-linearity in the top and bottom of the image, so that it is necessary to provide a non-linear or quadratic function current in order to correct it, and it is difficult to provide such a quadratic function current .

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and it is an object of the present invention to provide a method and apparatus for adjusting a correction position by varying an integration amount of a horizontal output signal, variably amplifying a voltage of a position- And a correction circuit for correcting the distorted image by applying the vertical output signal to the vertical deflection coil by superimposing the vertical output signal on the vertical output signal using an EI transformer.

According to an aspect of the present invention, there is provided an image processing apparatus including a correction position adjuster for adjusting an output position of a horizontal signal by adjusting a width of an output duty pulse of a horizontal output circuit, And a horizontal magnitude adjusting unit for adjusting the output magnitude and the magnitude of the horizontal magnitude of the output signal by the correction magnitude adjusting unit and the correction magnitude adjusting unit, And a modulation circuit unit which receives the vertical output signal from one end of the secondary coil and superposes the horizontal output signal and the vertical output signal and transmits the superposed vertical output signal to the vertical deflection coil connected to the secondary coil .

1 is a block diagram of a general display device,

Figs. 2A and 2B are exemplary views of abnormal display images,

3 is a partial block diagram of a display device to which the present invention is applied,

4 is a block diagram of a correction circuit for an image that is distorted in the vertical direction according to the present invention;

FIG. 5 is a detailed circuit diagram of the correction position adjusting unit of FIG. 4,

FIG. 6 is a detailed circuit diagram of the correction size adjuster of FIG. 4,

FIG. 7 is a detailed circuit diagram of the modulation circuit section of FIG. 4,

8 is a waveform diagram of a variable output signal of the correction position adjusting unit of FIG. 5,

FIG. 9 is a diagram illustrating the operation of the correction position adjusting unit shown in FIG.

Also,

10 is a waveform diagram of a variable output signal of the correction size adjuster of FIG. 6,

11 is displayed according to the variable output signal of the correction size adjuster in Fig. 6

Fig.

DESCRIPTION OF THE REFERENCE NUMERALS

1: Horizontal output circuit 2: Up-and-down distortion correction circuit

3, 400: Vertical output circuit 4, 500: Vertical deflection coil

10: computer 11: CPU

12: Video card 20: Monitor

21: microcomputer 22: control button section

23: vertical / horizontal output circuit section 24; Video circuitry

25: Power supply circuit unit 100:

200: correction size adjuster 300: modulation circuit

The present invention is for amplifying a synchronization signal Sync provided from a horizontal deflection end and modulating the same to a vertical circuit.

3 is a block diagram of a deflection circuit of a display device according to an embodiment of the present invention. The configuration of the other portions is shown in Fig. 1, and therefore, a description will be given of a deflection stage in which the present invention operates.

As shown in the figure, an upper / lower distortion correction circuit 2 for adjusting a correction position and a correction size of a vertical image using an output signal of the horizontal output circuit 1 converts the correction signal into an output signal of the vertical output circuit 3 To the vertical deflection coil (4).

FIG. 4 is a block diagram showing the upper and lower distortion correction circuits shown in FIG. 3.

A correction position adjuster 100 for varying the pulse width by integrating a horizontal signal of the horizontal output circuit as shown in the figure, a correction size adjuster 200 for adjusting the voltage level of the horizontal signal whose correction position is adjusted, A modulation circuit unit for superimposing the horizontal signal adjusted by the correction position adjustment unit 100 and the correction size adjustment unit 200 on the vertical output signal of the vertical output circuit 400 and outputting the vertical signal to the vertical deflection coil 500; (300).

5 is a detailed circuit diagram of the correction position adjusting unit shown in FIG. As shown in the figure, the correction position adjuster 100 determines the output duty pulse of the horizontal pulse as the R / C time constant composed of the variable resistor VR and the capacitor C0 and outputs a desired output duty pulse Multi- Vibrator).

FIG. 6 illustrates the correction magnitude adjusting unit 200 shown in FIG. 4, and includes a buffer unit 210 for adjusting a gain of an output signal of a multivibrator MV of the correction position adjusting unit 100, And an amplifying unit 220 for amplifying the gain-adjusted input signal.

The buffer unit 210 includes a plurality of resistors R1 to R4, a variable resistor VR2, and transistors Q1 to Q2.

The resistor R1 detects the output signal of the correction magnitude controller 200 and the resistors R2 and R3 are used as resistors for voltage dividing.

The detection resistor R2 is connected to the base end of the transistor Q1 and the resistor R3 is connected to the collector end. The emitter terminal of the transistor Q1 is connected to the emitter terminal of the transistor Q1 and the load resistor R4 is connected to the emitter terminal of the transistor Q2. At this time, a variable resistor (VR2) is connected to the base end of the transistor (Q2) for adjusting the value of the current flowing to the collector terminal.

The amplifying unit 220 for amplifying the gain-controlled input signal includes a plurality of resistors R5 to R13, amplifying transistors Q3 to Q5, capacitors C3 to C6 and diodes D1 to D4 .

A resistor R5 is connected to the base end of the transistor Q3, a resistor R6 is connected to the emitter end, and a diode D1 and a resistor R9 and a diode D2 are connected in series to the collector end. The base end of the transistor Q4 is connected to the collector end of the transistor Q3. A resistor R7 and a diode D4 are connected to the collector terminal of the transistor Q4 and a capacitor C3 and a resistor R8 are connected to the emitter terminal.

A diode D2 connected to the collector terminal of the transistor Q3 and a coil L1 are connected to the base end of the transistor Q5.

The capacitor C3 and the resistor R11 are connected to the emitter terminal of the transistor Q5 and the diode D3 and the resistors R11 and R14 are connected to the collector terminal.

A resistor R12, capacitors C5 to C6, and a resistor R13 are connected to a diode D4 connected to a collector terminal of the transistor Q4.

FIG. 7 is a detailed circuit diagram of the modulation circuit unit 300 of FIG. 4. The modulation circuit unit 300 includes an E-I transformer T1 and a capacitor C7 and a resistor R15.

The amplification unit 220 of the correction magnitude control unit 200 is connected to the c'-end of the E-I transformer T1, and the d'-end thereof is grounded. a vertical output circuit is connected to the a 'terminal, and a vertical deflection yoke (V_DY) is connected to the terminal b'.

The present invention having the above configuration operates as follows.

The horizontal output pulse applied to the multivibrator M-V of the correction position adjustment unit 100 is adjusted in accordance with the time constant of the variable resistor VR and the time constant of the capacitor C0.

The output signal of the multi-vibrator M-V is divided by the resistors R1 and R2 and applied to the base end of the emitter follow transistor Q1 through the resistor R2.

The resistor R4 connected to the emitter terminal of the transistor Q1 is used as a load resistor for controlling the maximum value of the current output to the collector terminal of the transistor Q2.

At this time, the value of the current output to the collector of the variable resistor (VR2) connected to the base end of the transistor (Q2) is adjusted according to the adjustment value.

An output signal of the collector terminal of the transistor Q2 is applied to the base end of the transistor Q3 and an output signal of the collector terminal of the transistor Q4 is fed back to the emitter terminal of the transistor Q3.

The transistor Q5 connected to the emitter terminal of the transistor Q4 stabilizes the emitter voltage of the transistor Q4.

The output signal of the collector terminal of the transistor Q5 is noise canceled by the peak coil L1 to stabilize the output voltage of the collector terminal of the transistor Q3 via the diodes D2 and D1 and the resistor R9 It works.

The output of the transistor Q4 passes through a coupling capacitor C5 via a diode D4 to form an inverse parabolic waveform in conjunction with the capacitor C6 and this signal is transmitted to the modulation transformer.

The correction-scaled signal is superimposed on the vertical output signal applied from the vertical output circuit 400 and outputted to the vertical deflection yoke V_DY in the E-I transformer T1.

The waveform changes according to the operation of the correction position adjusting unit 100 during the operation of each circuit according to the flow of the signal as described above is shown in FIG.

(a) shows a horizontal period pulse signal, and (b) is a signal of a preferable type integrated according to the magnitude of the time constant of the variable resistor VR and the capacitor C0. (c) is a first change waveform in which the integration amount is changed according to the change of the RC time constant, and (d) is a second change waveform in which the integration amount is changed in accordance with the change of the RC time constant.

Such a change in the waveform becomes a phenomenon in which the position of the image displayed on the screen is shifted as shown in FIGS. 9 (b), (c) and (d) when the horizontal period is shifted and overlapped with the vertical output signal.

In other words, when moving the horizontal period pulse, when (b) is regarded as a basic integral waveform, when the high state of the pulse is positioned in the first half of one period as shown in (c) The lower portion is distorted toward the center, and when the high state is positioned in the latter half of the period as shown in (d), the upper right and lower portions of the image are distorted.

On the other hand, the waveform of the horizontal output signal changes according to the amplification ratios of the transistors Q3, Q4, and Q5, as shown in FIG. (e) is a waveform of a horizontal period pulse, and (f) is a preferable output waveform of the correction position adjuster 100. [ (g) is a first variation waveform according to a change in amplification factor of the amplification unit 220, and (h) is a second variation waveform according to a variation in an amplification factor of the amplification unit 220. These waveform changes appear as shown in (f), (g), and (h) in the state in which they are superimposed on the vertical output signal and are displayed as shown in FIG.

In other words, when the peak-to-peak voltage is different from Vgp-p 'Vfp-p' Vhp-p ', the displayed image is displayed in the order of gfh It will appear close to the center.

As described above, according to the present invention, the correction amount is adjusted by varying the integration amount of the horizontal output signal using a multivibrator, the voltage of the position-corrected signal is variably amplified to adjust the correction size, The signal is superimposed on the vertical output signal using the EI transformer and applied to the vertical deflection coil, so that the distorted image can be corrected.

Claims (4)

A correction position adjuster for adjusting an output position of the horizontal signal by adjusting a width of an output duty pulse of the horizontal output circuit, A correction size adjuster for adjusting the output amplitude of the horizontal signal by variably amplifying the voltage of the horizontal signal whose output position is adjusted by the correction position adjuster, A horizontal output signal having an output position and an output size adjusted by the correction position adjusting unit and the correction size adjusting unit is applied to the primary coil and a vertical output signal is applied to one end of the secondary coil, And a modulation circuit section for superimposing the output signals and transmitting them to vertical deflection coils connected to the secondary coil. The method according to claim 1, Wherein the correction position adjustment unit comprises a multivibrator using a time constant of the variable resistor (VR) and the capacitor (C0) to vary the integration amount of the horizontal period pulse. The method according to claim 1, Wherein the correction size adjuster includes buffer means for adjusting an output gain of the correction position adjuster, And an amplifying means for amplifying the gain-adjusted input signal. The method according to claim 1, The modulation circuit unit receives the horizontal output signal from the primary coil, receives the vertical output signal from one end of the secondary coil, superimposes the horizontal output signal and the vertical output signal, and is connected to the other end of the secondary coil And an EI transformer for transmitting the vertical distortion to the vertical deflection coil.