FET discharging circuit of a horizontal deflection circuit

Details FET discharging circuit of a horizontal deflection circuit FET discharging circuit of a horizontal deflection circuit

1999-02-26

2001-05-01

Wong, Don (Department: 2821)

Electric lamp and discharge devices: systems

Cathode ray tube circuits

Cathode-ray deflections circuits

C315S399000

Reexamination Certificate

active

06225763

ABSTRACT:

CLAIM OF PRIORITY
This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. § 119 from an application entitled FET Discharging Circuit of a Horizontal Deflection Circuit earlier filed in the Korean Industrial Property Office on Feb. 26, 1998, and there duly assigned Ser. No. 98-2646 by that Office.
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates, in general, to a field effect transistor (FET) discharging circuit for a horizontal deflection circuit in a cathode ray tube display apparatus. More particularly, the invention relates to an FET discharging circuit for a horizontal deflection circuit in which a backward voltage is removed by connecting a diode, instead of a resistance, for discharging a high level voltage formed on an FET.
Generally, a cathode ray tube display apparatus has a vertical and a horizontal deflection circuit for deflecting an election beam discharged from a cathode of the cathode ray tube.
As explained in more detailed below, a horizontal deflection circuit for a cathode ray tube display apparatus includes a horizontal oscillator, a horizontal driving unit, a horizontal outputting unit, and an S-shaped correcting unit. The S-shaped correcting unit is typically connected in series with a horizontal deflection coil so as to linearly correct an image which is displayed in a distorted manner on the screen of the cathode ray tube.
In such arrangements, a high voltage generated at the output of the circuit can be removed by a discharge resistance provided in the output circuit. However, in actual practice, higher voltages occur in the output circuit, and it takes more time to discharge such higher voltages. This causes damage to the components of the output circuitry.
Therefore, there is a need for the development of an FED discharging circuit for a horizontal deflection circuit which is capable of producing an improved discharged effect such that the higher voltages, which cannot be quickly discharged in previous arrangements, can be discharged instantly without damage to the output circuit components.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an FET discharging circuit for a horizontal deflection circuit which is capable of improving a discharge effect by using a circuit in which a condenser is connected in parallel with a diode. That is in contrast with the arrangements of the conventional art in which discharging is performed by a resistance connected in parallel with an FET.
To achieve the above objects, there is provided an FET discharging circuit for a horizontal deflection circuit which includes: a horizontal oscillator for receiving a horizontal synchronous signal from a microcomputer, and for generating an output signal having a horizontal oscillating frequency identical to that of the horizontal synchronous signal; a horizontal driving unit driven by the output signal of the horizontal oscillator for generating an amplified pulse waveform of the same frequency as the horizontal oscillating frequency, and for outputting the amplified pulse through a transformer which provides electrical isolation from a high level power circuit; a horizontal outputting unit, driven by the output signal of the horizontal driving unit, for supplying a current to a horizontal deflection coil, the horizontal outputting unit being connected in parallel with a damping diode and a resonance condenser for resonating with the horizontal deflection coil, the horizontal deflection coil being connected in series with the horizontal outputting unit for receiving an output current from the horizontal outputting unit, and for generating a sawtooth current to adjust right and left deflections an electron beam of a screen; and an S-shaped correcting unit connected in series with the horizontal deflection coil for linearly correcting an image displayed in a distorted manner, the S-shaped correcting unit having a discharge device for instantly discharging when a high overvoltage is generated due to an abnormal operation.
Additional advantages, objects and other features of the invention will be set forth in part in the description which follows, and in part will become apparent to those having ordinary skill in the art upon examination of the following, or may be learned from practice of the invention. The object and advantages of the invention may be realized and attained as particularly pointed out in the appended claims.


REFERENCES:
patent: 4707640 (1987-11-01), Onozawa et al.
patent: 5068581 (1991-11-01), Nishiura et al.
patent: 5517090 (1996-05-01), Bando
patent: 5703443 (1997-12-01), Kwon
patent: 5831398 (1998-11-01), Kim
patent: 5877598 (1999-03-01), Pistemaa
patent: 5949201 (1999-09-01), Suzuki et al.
patent: 5955848 (1999-09-01), Arima et al.
patent: 5962994 (1999-10-01), Kwon et al.
patent: 6081079 (2000-06-01), Lee

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