Television pick-up device suitable for a discontinuous recording of information during continuous operation
AssigneeU.S. Philips Corporation
InventorsRudolf Kemner, Rudy R. Cramer
Life of this patent
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Abstract
A television pick-up device suitable for a discontinuous recording of information during continuous operation, such as, for example, in X-ray television. When information recording is interrupted at a continuing field scanning of a target plate in the pick-up tube, the cathode thereof is supplied from a supply circuit with a higher voltage than during the field scanning during information recording. As a result thereof a negative charging of the free surface of the target plate by the more rapid electrons in the electron beam is prevented, so that at the next recording of information the picture quality on display is not poorer due to signal clipping.
Claims6
A television pick-up device suitable for a discontinuous recording of information during continuous operation, the device comprising a pick-up tube having a cathode for generating an electron beam, a control electrode for controlling the electron beam current strength, and a target plate which is scanned line-by-line and field-by-field by the electron beam by means of deflection means, wherein the pick-up device further comprises a supply circuit coupled to the cathode of the pick-up tube, said supply circuit having means for providing a first voltage level to the cathode when information is being recorded by said pick-up device, and a second voltage level to the cathode when information is not being recorded, said second voltage level being higher than said first voltage level, whereby said second voltage level prevents said target plate from becoming more negative when information is not being recorded.
Dependencies are inferred from the claim text.