The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 27, 1990
Filed:
Jan. 15, 1988
Hitachi, Ltd., Tokyo, JP;
Abstract
A CRT (cathode ray tube) controller for controlling one CRT device in an interlace mode has a synchronizing circuit of bi-directional construction, in order to make possible synchronous operation of the CRT controller with other circuits (other CRT controllers or a TV system). When the CRTC is used as a master circuit of a CRT display system, a synchronizing signal is derived from the synchronizing circuit in synchronization with a count signal of a vertical scanning counter and an output of an interlace controller of the CRTC, and is supplied to a synchronizing terminal of the other CRTCs. Scanning counters and a flip-flop for controlling an interlace operation of the other CRTCs are reset to their initial state in synchronization with the synchronizing signal. When the CRTC is used as a slave circuit, scanning counters and a flip-flop of the CRTC are reset to their initial state in synchronization with the external synchronizing signal.