Picture display apparatus with beam scan velocity modulation
AssigneeU.S. Philips Corporation
InventorPhilippe Vilard
Life of this patent
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Abstract
A television set includes a circuit for modulating the horizontal velocity of the beam scan as a function of the video content with the aid of an auxiliary line deflection coil. The beam scan velocity modulation circuit includes a video signal differentiator circuit followed by an amplifier provided at the output of a power stage of the current generator type, which has its output connected to one terminal of the auxiliary line deflection coil. A voltage amplifier is provided at the output of a power stage of the voltage generator type which has its input connected to the output of the differentiator circuit, and its voltage output connected to the other terminal of the auxiliary line deflection coil.
Claims13
A picture display device comprising:
- a video signal source providing a video signal having video signal information components for display by a picture tube, a horizontal scanning circuit with a line deflection coil and a vertical scanning circuit for displaying a picture by means of a spot scanned on the screen of the picture tube,
- a beam scan velocity modulation circuit coupled to said video signal source for modulating the horizontal velocity of the spot as a function of the video content of said video signal with the aid of an auxiliary line deflection coil, and comprising a video signal differentiator circuit followed by a transconductance amplifier having an output including a power stage of the current generator type whose current output is connected to a first terminal of the auxiliary line deflection coil, wherein the beam scan velocity modulation circuit further includes a voltage amplifier having a power stage of the voltage generator type with an input connected to an output of the video signal differentiator circuit, and having an output connected to a second terminal of the auxiliary line deflection coil.
In a television apparatus including an auxiliary line deflection coil and a video signal source providing a video signal, a beam scan velocity modulation circuit comprising:
- a video signal differentiator circuit having an input coupled to an output of said video signal source,
- a transconductance amplifier having an input coupled to output means of the video signal differentiator circuit and having a current generator type output power stage coupled to a first terminal of the auxiliary line deflection coil, and
- a voltage amplifier having an input coupled to the output means of the video signal differentiator circuit and having a voltage generator type power stage coupled to a second terminal of the auxiliary line deflection coil.
Dependencies are inferred from the claim text.