Horizontal raster size controller for a monitor
AssigneeSamsung Electronics Co., Ltd.
InventorSeog-gi Kim
Life of this patent
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Abstract
A device for adjusting a horizontal raster size in a monitor is disclosed, wherein, by detection of beam current applied to a cathode ray tube of induced voltage across a flyback transformer. An error detector detects overvoltage or overcurrent and generates a pulse to a frame compensator. A variation in size of horizontal raster is regulated by controlling output signal of a horizontal output and deflection circuit, whereby a stabilized video frame in horizontal size is obtained.
Claims6
A horizontal raster size controller for a monitor, comprising:
- a horizontal output and deflection circuit providing a first signal to a primary winding of a horizontal flyback transformer, said flyback transformer providing a second signal to an anode of a cathode ray tube of said monitor;
- error detection means for generating an error detection signal by detecting overcurrent in said second signal provided to said anode of said cathode ray tube;
- comparison means for generating a first voltage signal indicative of a difference between said error detection signal and a reference potential;
- voltage-to-current conversion means for converting said voltage signal to corresponding current;
- means for providing a second voltage signal, said second voltage signal being varied in response to current output by said voltage-to-current conversion means;
- differential amplifying means for generating a differentially amplified signal by amplifying said second voltage level;
- and
- means for generating said compensation signal in response to said differentially amplified signal.
A horizontal raster size controller for a monitor in which an output signal of a horizontal output and deflection circuit is induced across a plurality of windings on secondary side of a flyback transformer driven by a switching mode operation of a flyback transformer voltage controller on a primary side of said flyback transformer to provide a signal to an anode of a cathode ray tube, said horizontal raster size controller comprising a compensation circuit, said compensation circuit comprising:
- error detection means for generating an error detection pulse signal by detecting a voltage level of said signal provided to said anode of said cathode ray tube;
- and
- compensation means coupled to receive said error detection pulse signal from said error detection means, said compensation means generates a current signal in response to said error detection pulse signal, generates a differentially amplified voltage in response to said current and generates a compensation signal in response to said differentially amplified voltage for compensating a horizontal raster size in a frame displayed by said monitor, said compensation signal being applied to said horizontal output and deflection circuit, said compensation means comprising:
- comparison means the receiving said error detection pulse signal and for generating a direct current voltage signal which represents a difference between said error detection pulse signal and a reference potential;
- voltage-to-current conversion means for converting said direct current voltage signal generated from said comparison means to corresponding current;
- amplifying means for receiving an varied voltage level varied in response to a value of said current and for generating an amplified signal by differentially amplifying said varied voltage level;
- and
- means for generating said compensation signal in response to said amplified signal;
- said comparison means comprising:
- a first resistor and a capacitor coupled in series between said error detection means and said reference potential smoothing said error detection pulse signal;
- and
- an operational amplifier having a non-inverting input terminal coupled to a common connection between said resistor and said capacitor for receiving the smoothed error detection pulse signal, and an inverting input terminal connected to said reference potential via a second resistor, an output terminal of said operational amplifier being connected to said inverting input terminal via a third resistor, said operation amplifier generating said direct current voltage signal in response to a comparison between said smoothed error detection signal and said reference potential supplied through said second resistor.
A horizontal raster size controller for a monitor in which an output signal of a horizontal output and deflection circuit is induced across a plurality of windings on secondary side of a flyback transformer driven by a switching mode operation of a flyback transformer voltage controller on a primary side of said flyback transformer to provide a signal to an anode of a cathode ray tube, said horizontal raster size controller comprising a compensation circuit, said compensation circuit comprising:
- error detection means for generating an error detection pulse signal by detecting a voltage level of said signal provided to said anode of said cathode ray tube;
- and
- compensation means coupled to receive said error detection pulse signal from said error detection means, said compensation means generates a current signal in response to said error detection pulse signal, generates a differentially amplified voltage in response to said current and generates a compensation signal in response to said differentially amplified voltage for compensating a horizontal raster size in a frame displayed by said monitor, said compensation signal being applied to said horizontal output and deflection circuit, said compensation means comprising:
- comparison means for receiving said error detection pulse signal and for generating a direct current voltage signal which represents a difference between said error detection pulse signal and a reference potential;
- voltage-to-current conversion means for converting said direct current voltage signal generated from said comparison means to corresponding current;
- amplifying means for receiving an varied voltage level varied in response to a value of said current and for generating an amplified signal by differentially amplifying said varied voltage level;
- and
- means for generating said compensation signal in response to said amplified signal, said means for generating said compensation signal in response to said amplified signal comprising:
- a first transistor Darlington connected to a second transistor, a base of said first transistor coupled to receive said amplified signal, a collector of said first transistor being connected to said reference potential via a resistor and a base of said second transistor being directly connected to said reference potential;
- a voltage source connected to an emitter of said second transistor;
- a capacitor connected between said reference potential and said emitter of said second transistor;
- and
- an inductor coupled to said emitter of said second transistor for outputting said compensation signal to said horizontal output and deflection circuit.
Dependencies are inferred from the claim text.