Automatic kinescope bias control circuit

Details Automatic kinescope bias control circuit Automatic kinescope bias control circuit

1978-10-13

1980-06-10

Murray, Richard

Facsimile and static presentation processing

Static presentation processing

Attribute control

358 33, 358171, H04N 516

Patent

active

042075920

ABSTRACT:
Apparatus for automatically controlling the bias of an image reproducing color kinescope in a system incuding a plurality of video driver stages for supplying image representative video signals to respective intensity control electrodes of the electron guns of the kinescope. The output of each driver stage is coupled to an operating supply voltage via a load impedance. The electron gun currents (e.g., cathode currents) are sensed during image blanking intervals of the video signal to provide respective control voltages representative of the electron gun blanking current levels. The control voltages are respectively applied to control the output operating voltage of each driver stage, and thereby the electron gun bias, in a manner to reduce deviations of the blanking current level from a normally expected level. In one embodiment, each driver stage comprises a transistor with a video input base electrode, and a collector output electrode coupled to an electron gun. The control voltage is applied to the collector circuit of the transistor for varying the quiescent current through the load impedance and the collector quiescent output potential independent of the video signal, to thereby vary the electron gun bias in a direction for reducing the blanking current. Interaction between the control voltages and video signals is minimized, and the apparatus is suitable for use with kinescopes having separately energized grids or with kinescopes having grids energized from a common source.

REFERENCES:
patent: 3449619 (1969-06-01), Stalp
patent: 4012775 (1977-03-01), Smith
"Permanent Colour Truth," (Publication by Bang & Olufsen, Denmark).
"Towards True Color Stability in Television," Videocolor S.A., Paris, France, No. 1600, Jun. 1978.
"Color Receiver Design", E. A. Jensen, Wireless World, Jul., 1978.

Affiliated with

Also associated with

Rating

Automatic kinescope bias control circuit does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Automatic kinescope bias control circuit, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Automatic kinescope bias control circuit will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-866213