JPH02154575A - Linearity compensation device for deflection circuit - Google Patents

Abstract

PURPOSE:To obtain a stable video image on a curved face screen by juxtaposing an inductor for correcting nonlinear distortion connecting to a deflection yoke with an electromagnet and supplying a DC current in response to an input frequency to the coil of the electromagnet from a DC power supply. CONSTITUTION:The inductor 5c correcting nonlinear distortion of a deflection current in a deflection yoke is formed by winding a coil 12 onto a magnetic core 11 and an electromagnet 13 is juxtaposed with the inductor 5c. A signal inputted to a transistor(TR) 1 is fetched in a DC power supply to apply the frequency/voltage conversion and the rectification of the signal and the resulting current is applied to the coil 15 of the electromagnet 13 as a predetermined distortion correction pattern. Thus, the characteristic of the inductor 5c is changed so as to correct nonlinear distortion of the deflection current in response to the magnetic core characteristic of the electromagnet due to the distortion correction pattern current. Thus, a stable video picture is displayed on a curved face screen.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a linearity compensation device for a deflection circuit that prevents distortion in a reproduced image due to the flow of an extra-deflection current in the deflection circuit of a CRT display monitor.

[Conventional technology]

FIG. 3 is a circuit diagram showing a conventional linearity compensation device for a deflection circuit. In the figure, 1 is a transistor that outputs an output current according to the horizontal frequency, and 2 is a transistor that improves the switching characteristics of this output transistor 1. A damper diode, 3 is also a choke, and 4 is a deflection yoke. The deflection yoke 4 is connected in series with an inductor 5 and a capacitor 6 for correcting nonlinear distortion of the deflection current. Moreover, FIG. 4 shows a conventional example of the above-mentioned inductor 5.
What is shown in Figure (a) is a magnetic core 8 integrated with a permanent magnet 7.
The fixed inductor 5A has a coil 9 wound around the magnetic core 8, and the one shown in FIG. 4(b) is a movable inductor 5B that rotates or moves the permanent magnet 7. It is. Next, the operation will be explained. First, the transistor 1 stabilizes a deflection current, which is an output current according to the input frequency, by the damper diode 2 and the choke 3, and then supplies it to the deflection yoke 4. In this case, the deflection current is between the inductor 5 and the capacitor 6.
Linear correction of the waveform is performed by the resonant circuit characteristics. By the way, in such a linearity compensation circuit, when the input frequency for switching driving the transistor 1 changes, the characteristics of the inductor 5 and capacitor 6 change, and therefore, these constants must be changed. Therefore, as shown in Part 5, two types of capacitors 6a and 6b are used to correct the nonlinear distortion according to the change in the input frequency.
It has been considered that the inductor 5 is selectively connected to the inductor 5 by switching the relays 10a and 10b.

[Problem to be solved by the invention]

Since the conventional linearity compensator for a deflection circuit is configured as described above, it is necessary to change the resonance circuit characteristics by switching the relays 10a and IOb one by one according to the change in the input frequency. If the frequency changes over a larger range, it is not possible to set an appropriate resonance constant, and the non-linear distortion of the deflection current cannot be reliably suppressed. This invention was made to solve the above problems, and provides a linearity compensator for a deflection circuit that can appropriately correct nonlinear distortion of a deflection current regardless of changes in input frequency. The purpose is to obtain.

[Means to solve the problem]

A linearity compensator for a deflection circuit according to the present invention has an electromagnet installed in parallel with an inductor for non-linear distortion correction connected to a deflection yoke, and a DC current output from a DC multiplex according to an input frequency. - The non-linear distortion is automatically corrected optimally by being supplied to the coil of the distribution magnet.

[For use]

In the DC power supply according to the present invention, in order to supply a DC current according to the input frequency to the coil of the electromagnet, the constant of the inductor is changed according to the input frequency, thereby deflecting the deflection supplied to the deflection yoke. Operates to automatically correct non-linear distortions in current.

[Embodiment 1] An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, 5C is an inductor for correcting non-linear distortion of the deflection current passing through the deflection yoke, and this is made up of a magnetic core 11 wrapped with an ml coil 12, as shown in FIG. Further, 13 is an electromagnet arranged in parallel with the inductor 5c, 14 is a magnetic core forming the electromagnet 13, and 15 is a coil wound around the magnetic core 14. Further, I6 is a DC power supply that outputs a DC current according to the input frequency, and this is configured with a frequency/voltage converter and a rectifier, and is used to correct nonlinear distortion of the deflection current for the coil I5 of the electromagnet 13. Supplies direct current for Note that other circuit parts that are the same as those shown in FIG. 3 are given the same reference numerals, and redundant explanation thereof will be omitted. Next, the operation will be explained. The mass transistor 1 transmits a deflection current according to the input frequency to the damper diode 2. Stabilized by choke 3,
It is supplied to the deflection yoke 4. On the other hand, the signal input to the transistor 1 is taken into the DC power supply 16, which performs frequency/voltage conversion and rectification, and converts the signal into a current having a predetermined distortion correction pattern to the coil 1 of the electromagnet 13.
5. Therefore, the inductor 5c corrects the non-linear distortion of the deflection current according to the magnetic core characteristics of the electromagnet due to the current of the distortion correction pattern.
Characteristic changes are made. As a result, a stable video image can be displayed on the curved screen. This linearity compensation device can be applied to linear compensation of the deflection current flowing through either the vertical or horizontal deflection yoke. [Effects of the Invention] As described above, according to the present invention, an electromagnet is installed in parallel to the nonlinear distortion correction inductor connected to the deflection yoke, and a DC current corresponding to the input frequency is applied from the DC power source to the coil of the electromagnet. Therefore, the non-linear distortion of the deflection current flowing through the deflection yoke described in (g) can be automatically and appropriately corrected regardless of changes in the input frequency.
Therefore, there is an effect that a stable image can be obtained on a curved screen.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing a linearity compensation device for a deflection circuit according to an embodiment of the present invention, Fig. 2 is an explanatory diagram showing the inductor and electromagnet of Fig. 1, and Fig. 3 is a circuit diagram showing the linearity compensating device for a deflection circuit according to an embodiment of the present invention. FIG. 4 is an explanatory diagram showing the inductor of FIG. 3, and circuit diagram 1 shows another conventional example of the Ca+linearity compensator. 1 is a transistor, 4 is a deflection yoke, 50 is an inductor, 13 is an electromagnet, 15 is a coil, and 16 is a DC power supply. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. Patent applicant Mitsubishi Electric Corporation agent
Patent attorney 1) Hiroshi Sawa (2 others)

Claims (1)

[Claims] A transistor that outputs an output current according to an input frequency, a deflection yoke that electromagnetically deflects an electron beam in response to the output current from this transistor, and an inductor and a capacitor that correct nonlinear distortion of the deflection current in this deflection yoke. A linearity compensator for a deflection circuit comprising: an electromagnet installed in parallel with the inductor; and a DC power source that supplies a DC current according to the input frequency to the coil of the electromagnet to change the characteristics of the inductor. A linearity compensator for a deflection circuit, characterized in that: