Title:
TELEVISION RECEIVER
Document Type and Number:
Japanese Patent JPS6397077
Kind Code:
A
Abstract:
PURPOSE:To generate not a white random signal but random signals of primary colors of red, green and blue at the time of silence and in black-and-white broadcasting by providing three oscillation circuits, voltage comparators and switching circuits respectively and one switching circuit and the like. CONSTITUTION:Composite video signals are in a state where bias voltages are changed by the oscillation circuits 64, 65 and 66 and they are inputted to voltage comparators 11, 31 and 51, which output random signals of red, green and blue as the outputs from the switching circuits 20, 40 and 60. Then, the outputs from the switching circuits 20, 40 and 60 are inputted to the input terminals (m), (o) and (q) of the switching circuit 61, and color difference signals obtained from the composite video signals are inputted to the other terminals. An alternation switch 62 selects either the random signal or the color difference signal, which a CRT drive circuit 63 displays on a CRT. Thus, not the white random signal, but the random signals of primary colors of red, green and blue can be generated even at the time of silence and in black-and-white broadcasting.
Inventors:
HARA KENJI
Application Number:
JP24346686A
Publication Date:
April 27, 1988
Filing Date:
October 14, 1986
Export Citation:
Assignee:
MATSUSHITA ELECTRIC IND CO LTD
International Classes:
H04N9/00; (IPC1-7): H04N9/00
Attorney, Agent or Firm:
Akira Kobiji (2 outside)