JPH07336554A - Image correction device - Google Patents

Abstract

PURPOSE:To eliminate the need for write of data to a memory by providing a horizontal, vertical deflection current detector, a convergence output circuit driven by the output of an arithmetic unit, a vertical pincushion distortion correction output circuit and a dynamic focus output circuit to the device. CONSTITUTION:A horizontal deflection current flowing to a horizontal deflection coil L1 is converted into a voltage similar to a horizontal deflection current by a resistor R1. A current flowing to a vertical deflection coil L2 is converted into a voltage similar to a vertical deflection current by a resistor R2. Both voltages are fed to an arithmetic unit 3 comprising multipliers MP1, MP2, and an adder ADD 1 and a correction waveform is generated. The correction waveform is given to a convergence output circuit 4 to drive a convergence coil L3. Furthermore, the correction waveform is given to a vertical pincushion distortion correction output circuit 5 to drive the coil 2. Moreover, the correction waveform is given to a dynamic focus output circuit to drive a focus electrode 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image correction device used for a television receiver, a display device or the like.

[0002]

2. Description of the Related Art In recent years, there has been a demand for a highly accurate and inexpensive convergence correction circuit, upper and lower pincushion distortion correction circuit, and a dynamic focus circuit in television receivers and display devices. Particularly, in a multi-scan type display device, an inexpensive circuit that accurately follows changes in frequency and amplitude is required.

The applicant of the present invention automatically corrects various corrections such as deflection, brightness, focus and screen phase by using digital correction data from a storage device in which various correction data is previously stored and various analog correction waveforms. An image correction device was proposed (see Japanese Patent Application No. 2-229394 application document).

This image correction device will be described with reference to FIG. The pattern generator 25 generates, for example, a crosshatch pattern and displays it on the screen of the display means. Further, the synchronization signal is also supplied to the correction waveform generator 27 to create an analog correction waveform in each scanning direction and input to the reference potential input terminal of the multiplication D / A converter 26. Digital data from the memory 23 in which various correction data are stored is a multiplication type D /
It is supplied to the data input terminal of the A conversion unit 26. Where D
The A / A converted signal is multiplied by the analog correction waveform to suppress the amplitude and DC potential of the correction waveform, and the correction circuit 30 automatically performs various corrections such as convergence, deflection, focus, brightness and screen phase. Be seen.

[0005]

However, in the above-described conventional configuration, when a plurality of signals having different horizontal frequencies, image amplitudes, etc. are received, it is necessary to write (preset) the data in the memory, and the operation is performed. It had a problem that the circuit was complicated and the circuit was complicated.

The present invention solves the above-mentioned conventional problems. Even when a plurality of signals having different horizontal frequencies and image amplitudes are received, it is not necessary to write (preset) data in the memory. It is an object of the present invention to provide an inexpensive image correction device.

[0007]

In order to achieve this object, the image correction apparatus of the present invention uses a horizontal deflection current detector that generates a voltage similar to the horizontal deflection current and a voltage similar to the vertical deflection current. A vertical deflection current detector that is generated, an arithmetic unit that calculates the outputs of both detectors, a convergence output circuit that is driven by the arithmetic output, an upper and lower pincushion distortion correction output circuit, and a dynamic focus output circuit. It has the following structure.

[0008]

With this configuration, a voltage waveform similar to the deflection current is calculated and various corrections are performed. This gives the horizontal frequency,
It is not necessary to write (preset) data in the memory even when a plurality of signals having different image amplitudes are received, and an inexpensive image correction apparatus can be provided.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is a horizontal deflection current detector that generates a voltage similar to the horizontal deflection current, 2 is a vertical deflection current detector that generates a voltage similar to the vertical deflection current, 3
Is a computing unit for computing outputs of both detectors, 4 is a convergence output circuit driven by the computing output, 5 is a top and bottom pincushion distortion correction output circuit driven by the computing output, and 6 is a dynamic focus output circuit driven by the computing output Is.

The operation of the image correction apparatus constructed as above will be described. First, the horizontal deflection current flowing through the horizontal deflection coil L1 is converted into a voltage similar to the horizontal deflection current by the resistor R1, and the horizontal deflection current flowing through the vertical deflection coil L2 is converted into a voltage similar to the vertical deflection current by the resistor R2. , Both voltages are input to the arithmetic unit 3 composed of the multipliers MP1, MP2 and the adder ADD1,
Generate a correction waveform. The corrected waveform is input to the convergence output circuit 4 and drives the convergence coil L3. The correction waveform is input to the upper and lower pincushion distortion correction output circuit 5 to drive the vertical deflection coil L2. The corrected waveform is input to the dynamic focus output circuit 6 to drive the focus electrode G3.

Even when a plurality of signals having different horizontal frequencies, image amplitudes, etc. are received, the change appears as a change in the deflection current, and the correction waveform follows the change, so the horizontal frequency,
Even when receiving a plurality of signals having different image amplitudes, it is not necessary to write (preset) data in the memory, and an excellent effect that an inexpensive image correction apparatus can be provided can be obtained.

Although the horizontal deflection current detector 1 is the resistor R1 in the above embodiment, a current transformer may be used. Although the vertical deflection current detector 2 is the resistor R2, a current transformer may be used. Also, the multiplier M
Instead of the arithmetic unit 3 composed of P1, MP2 and the adder ADD1, an arithmetic unit composed of a polygonal line approximate amplifier by a diode or the like may be used.

[0013]

As described above, according to the present invention, a horizontal deflection current detector for generating a voltage similar to a horizontal deflection current, a vertical deflection current detector for generating a voltage similar to a vertical deflection current, and both detectors. By providing a calculator that calculates the output, a convergence output circuit driven by the calculation output, a top and bottom pincushion distortion correction output circuit, and a dynamic focus output circuit, when multiple signals with different horizontal frequencies, image amplitudes, etc. are received Also, it is not necessary to write (preset) data in the memory, and an excellent effect that an inexpensive image correction apparatus can be provided can be obtained.

[Brief description of drawings]

FIG. 1 is a circuit configuration block diagram of an image correction apparatus according to an embodiment of the present invention.

FIG. 2 is a circuit configuration block diagram of a conventional image correction device.

[Explanation of symbols]

 1 horizontal deflection current detector 2 vertical deflection current detector 3 calculator 4 convergence output circuit 5 upper and lower pincushion distortion correction output circuit 6 dynamic focus output circuit L1 horizontal deflection coil R1 resistance L2 vertical deflection coil R2 resistance MP1, MP2 multiplier ADD1 addition L3 Convergence coil L3 G3 Focus electrode

Claims (1)

[Claims] 1. A horizontal deflection current detector for generating a voltage similar to a horizontal deflection current, a vertical deflection current detector for generating a voltage similar to a vertical deflection current, and an arithmetic unit for calculating outputs of both detectors. An image correction apparatus comprising at least one of a convergence output circuit driven by the output of the arithmetic unit, an upper and lower pincushion distortion correction output circuit, and a dynamic focus output circuit.