Sony Corporation

Junzo Watanabe

Ken Kikuchi

Hidetaka Honji

Ban Kawamura

Seiji Kawaberi

Akihiro Ueyama

Masahiro Suzuki

Kenji Iwai

Susumu Otaki

An appartus for adjusting the correction amount of a horizontal linearity and suppressing the amplitude of a horizontal deflection current in an image display device. A switching element,is provided between both ends of an S-curve correction capacitor,connected in series to a horizontal deflection coil,, and by turning on this switching element,during a horizontal retrace period to discharge the S-curve correction capacitor,, and controlling also the ON time of this switching element,, the linearity in the horizontal period is corrected.

Horizontal linearity correcting circuit

A horizontal deflection circuit capable of performing various corrections. It is characterized by grounding one end of a first parallel circuit connecting a first switching element,, a first damper diode,, and a first resonance capacitor,in parallel, connecting the other end of the first parallel circuit to one end of a second parallel circuit connecting a second switching element,, a second damper diode,, and a second resonance capacitor,in parallel, and further connecting the other end of this first parallel circuit to a direct-current power source terminal through a primary winding of a flyback transformer,, grounding the other end of this second parallel circuit through a series circuit of a horizontal deflection coil,and an S-curve correction capacitor,, grounding the connection middle point of the horizontal deflection coil,and S-curve correction capacitor,through a parallel circuit of an intermediate pincushion distortion correction circuit,and a horizontal linearity correction circuit,, and installing switching element control means,for switching the first switching element,by a horizontal drive signal, and controlling the OFF start timing and OFF period of the second switching element

Horizontal deflection circuit

This invention is directed to a circuit for permitting stable operation of horizontal deflection output, and comprises: a first parallel circuit P,composed of a first switching element,, a first damper diode,and a first resonance capacitor,; a second parallel circuit P,composed of a second switching element,, a second damper diode,and a second resonance capacitor,; a horizontal deflection yoke,connected to the second parallel circuit P,; a flyback transformer,; an integration circuit,operative to synthesize pulses from the first and second parallel circuits P,, P,to generate deflection current and to integrate inputted horizontal deflection drive signal; first and second comparison&bull;latch circuits,for respectively comparing signal from the integration circuit,with first and second levels to latch comparison results; first and second drive circuits,for respectively driving the first and second switching elements,; and a control element for controlling the second level.

A horizontal deflection circuit is provided in which a large retrace pulse voltage applied to a horizontal deflection yoke can be taken to reduce the deflection current and which is capable of easily performing horizontal image size adjustment and distortion adjustment. A parallel connection of a switching element, a damper diode, and a resonance capacitor is connected in series to a parallel connection of another switching element, another damper diode, and another resonance capacitor, and power is supplied from the connection point via a fly-back transformer. The comparison value of the retrace pulse voltages applied across both ends of the switching elements is fed back through a switching element control circuit to the switching element so that the deflection current of the horizontal deflection yoke is controlled.

There is provided a sine wave deflecting circuit having a resonance circuit comprising a deflecting coil and a resonance capacitor and a circuit for detecting a signal waveform of the resonance circuit and for driving the resonance circuit on the basis of the detection signal, in which the deflecting coil is sine-wave driven by the self-oscillation. A rectangular wave driving circuit which is constructed by connecting first and second switching elements such as FETs through a capacitor is provided at one end of the deflecting coil.

Sine wave deflecting circuit

In a dual direction horizontal bi-directional scan circuit, deterioration of the picture quality is prevented, while linearity is improved without supplying wasteful deflecting current, and pin distortion is corrected. The deflecting current in the going scan and in the returning scan are supplied to each deflecting coil by first and second resonance circuits, and capacitors substantially the same in capacitance are provided in the first and second resonance circuits to bias the deflecting voltage so that the terminal voltage and the power source voltage of the capacitors are synchronized to the vertical synchronizing signals to produce a parabolic modulation.

Bi-directional scan circuit

At a horizontal deflecting circuit of bi-directional deflection, timings of deflection of forward scan path and backward scan path are respectively controlled. The timing of deflection of forward path or backward path is controlled at the first timing control circuit 22 so that it is synchronized with the horizontal synchronizing signal HD and timing of deflection of backward path or forward path is controlled at the second timing control circuit 24 so that deflection cycles of forward path and backward path are equalized. Further, timings of deflection of forward scan path and backward scan path are controlled respectively at first and second phase comparison circuits 22 and 24 so that the relation in phase between the image signal and the deflection takes a constant value on the basis of the horizontal synchronizing signal, to previously prevent occurrence of steady phase error.

A coil (11) is connected in series to a primary winding (1a) of a flyback transformer (1). A series circuit of a capacitor (15) and a switching circuit (12) is connected in parallel to the coil (11). By turning on and off the switching circuit (12), the connection of the capacitor (15) to the coil (11) is switched, to thereby connect or disconnect the coil (11) in an AC fashion. Therefore, it is possible to realize a high voltage regulating circuit which can be made inexpensive.

High voltage regulating circuit

A sine wave deflecting circuit has a simplified configuration capable of ensuring an efficient and stable operation with a function of facilitating external synchronization. The deflecting circuit comprises a resonant circuit comprising a deflecting coil and a resonant capacitor, and a circuit for detecting a signal waveform of the resonant circuit and driving the resonant circuit in accordance with the detection signal, wherein the deflecting coil is driven with sine waves generated by self-oscillation. A deflection interruption time is set during the driving action, and the sine-wave driving frequency is controlled by controlling the length of such interruption time.

In a horizontal deflection output circuit adapted for correction of horizontal linearity in a television receiver or the like, and which comprises a switching transistor, a damper diode, a horizontal deflecting coil and an S correcting capacitor connected in series to the horizontal deflecting coil; the terminal voltage of the S correcting capacitor is modulated by a sawtooth signal produced by a linear distortion correcting circuit synchronously with a horizontal periodic signal. The sawtooth signal produced by the switching transistor and fed to the horizontal deflecting coil is applied to the S correcting capacitor which feeds an S correcting current to the horizontal deflecting coil, so as to correct the image distortion caused particularly by the resistance component of the horizontal deflecting coil.

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Kanagawa, Japan

Junzo Watanabe