JPH05336394A - Vertical pincushion correction circuit - Google Patents

Abstract

PURPOSE:To always perform appropriate correction by monitoring a vertical pincushion correcting state and simultaneously, to supply an appropriate source voltage to a horizontal deflection circuit even when steep fluctuation occurs in a horizontal frequency. CONSTITUTION:A power source output voltage is controlled by comparing the mixing output of the modulation waveform of the power source output voltage with output in which the collector pulse of a horizontal output transistor Q1 is detected and peak-rectified with a voltage in which a reference DC voltage is modulated by a vertical pincushion correcting waveform, and vertical pincushion correction quantity is controlled, and also, the appropriate source voltage is supplied to the horizontal deflection circuit 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical pincushion correction circuit system for horizontal and vertical multi-frequency display monitors and the like.

[0002]

2. Description of the Related Art In recent years, the horizontal frequency of personal computers and the like has become higher with higher definition, and there are display monitors on the market which can support various horizontal frequencies up to high frequencies.

A conventional display monitor vertical pincushion correction circuit system will be described below. FIG. 2 shows a conventional vertical pincushion correction circuit system. In FIG. 2, reference numeral 1 is a chopper control type power supply circuit.
Reference numeral 2 is a horizontal deflection circuit, 3 is a collector pulse detection circuit for horizontal output transistors, and 4 is a peak rectification circuit for the pulse. Reference numeral 5 is a horizontal amplitude control circuit, 6 is a vertical pincushion correction waveform generating circuit, and 7 is an error amplifying circuit for controlling the output voltage of the chipper control system power supply.

The operation of the vertical pincushion correction circuit system configured as described above will be described below. First, when the horizontal frequency of the input signal changes, the peak value of the collector pulse of the horizontal output transistor Q1 changes. This pulse is detected and peak rectified at 3 and 4, is controlled by the DC voltage of the horizontal amplitude control circuit of 5, and is input to the negative terminal of the error amplification circuit of 7. The voltage obtained by modulating the reference DC voltage with the vertical pincushion correction waveform is input to the positive terminal of 7. The output of 7 is the difference between the positive terminal reference voltage and the negative terminal voltage, and the modulation of the vertical pincushion correction waveform is added. The output voltage of the chopper control type power supply 1 is controlled and supplied to the horizontal deflection circuit to perform vertical pincushion correction.

[0005]

However, in the above-mentioned conventional configuration, when the vertical frequency changes, the peak rectification characteristic of the detection pulse changes to affect the vertical pincushion correction, and the vertical pincushion correction is monitored. Since no correction is performed, the vertical pincushion correction that has been affected and changed remains as it is, and there is a problem that the received signal on the surface of the cathode ray tube looks bent.

The present invention solves the above-mentioned conventional problems. In the closed-loop control in which the modulation waveform of the power supply output is fed back AC and is compared with the vertical pincushion correction waveform to control the power supply output voltage, the vertical pin is used. An object of the present invention is to provide a circuit system that constantly monitors and corrects the cushion correction to perform stable vertical pincushion correction.

[0007]

In order to achieve this object, the circuit system of the present invention is a power supply circuit of a chipper control system, a circuit for extracting a modulation waveform of the power supply output voltage, and a collector pulse of a horizontal output transistor. Circuit, a circuit for rectifying this pulse, a vertical pincushion correction waveform generation circuit, and an error amplification circuit for controlling the output voltage of the chopper control type power supply.

[0008]

With this configuration, when the waveform of the power supply output voltage modulated for vertical pincushion correction changes due to the change in vertical frequency, this modulated waveform is fed back and the error amplifier circuit AC-converts the vertical pincushion correction waveform. The correction of the correction is performed by controlling the power supply circuit of the chipper control system in comparison with the above, so that stable vertical pincushion correction can always be performed. At the same time, in the error amplifier circuit, the output voltage of the peak rectification is compared with the reference voltage in terms of direct current, so that an appropriate output voltage can be supplied to the horizontal deflection circuit.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 11 is a chipper control type power supply circuit for supplying power to 12 horizontal deflection circuits,
Reference numeral 13 is a circuit for detecting the collector pulse of the horizontal output transistor Q1 and reference numeral 14 is a circuit for peak rectifying this pulse. Reference numeral 15 is a horizontal amplitude control circuit, 16 is a circuit for extracting a modulation waveform of the power supply output voltage, 17 is a mixing circuit for the output from the peak rectification and the power supply output voltage modulation waveform, 18 is a vertical pincushion correction waveform generation circuit, and 19 is an error. It is an amplifier circuit.

The operation of the circuit system configured as above will be described. First, the collector pulse of the horizontal output transistor Q1 is detected by the capacitors C1 and C2, and the diode D1 and the capacitor C3 are passed through the transistor Q2.
Peak rectification at. Then, after controlling the peak rectification output level by the DC voltage level of the horizontal amplitude control circuit of 15, 1
The modulated waveform AC component extracted in 6 and the circuit in 17 are mixed and input to the negative terminal of 19. A voltage obtained by modulating the reference DC voltage with the vertical pincushion correction waveform is input to the positive terminal of 19, and the output of 19 is the output of the difference between the vertical pincushion correction waveform and the field-backed power supply modulation waveform in terms of AC. In terms of direct current, the output is the difference between the reference voltage and the peak rectified output, and this controls the output voltage of the power supply of the chipper control system to perform vertical pincushion correction and simultaneously supply an appropriate voltage to the horizontal deflection circuit.

[0012]

As described above, according to the present invention, by providing a circuit for extracting the modulation waveform of the power supply output voltage, the modulation waveform and the vertical pincushion correction waveform are compared in terms of alternating current, and a chopper control type power supply is provided. By controlling, it is possible to easily realize stable vertical pincushion correction.

[Brief description of drawings]

FIG. 1 is a diagram of a vertical pincushion correction circuit system according to a first embodiment of the present invention.

[Fig. 2] Conventional vertical pincushion correction circuit system diagram

[Explanation of symbols]

 11 Chopper Control System Power Supply Circuit 12 Horizontal Deflection Circuit 13 Horizontal Output Transistor Collector Pulse Detection Circuit 14 Peak Rectification Circuit 15 Horizontal Amplitude Control Circuit 16 Power Supply Voltage Modulation Waveform Fieldback Circuit 17 Mixing Circuit 18 Vertical Pincushion Correction Waveform Generation Circuit 19 Error Amplification Circuit FBT Flyback transformer V voltage

Claims (3)

[Claims] 1. A chopper control system power supply circuit, a circuit for feeding back a modulation waveform of a power supply output voltage thereof, a vertical pincushion correction waveform generation circuit, and an error amplification circuit for controlling a chopper control system power supply. A vertical pincushion correction circuit characterized by performing a vertical pincushion correction by controlling the power supply output voltage by comparing the voltage modulation waveform and the vertical pincushion correction waveform with an error amplification circuit. 2. A chopper control type power supply circuit, a circuit for detecting a collector pulse of a horizontal output transistor, a circuit for peak rectifying this pulse, a circuit for feeding back a modulation waveform of a chopper power supply output voltage, and this modulation waveform. Equipped with a circuit that mixes the peak rectified output, a vertical pincushion correction waveform generation circuit, and an error amplification circuit that controls the chopper control power supply, and modulates the voltage from the mixing circuit and the reference voltage with the vertical pincushion correction waveform. The vertical pincushion correction circuit is characterized by comparing the generated voltage with an error amplification circuit to control the power supply output voltage to perform vertical pincushion correction and at the same time supply an appropriate power supply output voltage according to the horizontal frequency. 3. A power source for externally controlling the output voltage, and a circuit for field-backing the modulation waveform of the output voltage.
A vertical pincushion correction waveform generation circuit and an error amplification circuit that controls the power supply are provided, and the power amplifier output voltage is controlled by comparing the power supply output voltage modulation waveform and the vertical pincushion correction waveform with the error amplification circuit. Vertical pincushion correction circuit characterized by performing pincushion correction.