U.S. Patent Number: RE36,801
Time Delayed Digital Video System using Concurrent Recording and Playback
Date Filed: October 29, 1992
Date Issued: December 6, 1995
Date Filed for Reissue: April 18,1996
Date Reissued: August 1, 2000
Abstract:
A broadcast recording and playback device employing a "circular buffer" which constantly records one or more incoming audio or video program signals and a microprocessor for accessing the memory to read a playback signal from the circular buffer to display programming material delayed from its receipt by a selectable delay interval. The circular buffer is implemented by a digital memory. Subsystem comprising the combination of a semiconductor RAM memory and a disk memory operated under the control of a microprocessor such that incoming signals are constantly recorded as received, while at the same time delayed signals are being read from the memory subsystem at a different memory location selected by a microprocessor to provide a user-selected time delay. A plurality of input signal processors provides one or more programming signals to the memory subsystem in compressed digital form and a separate output signal processor converts the compressed digital information read from the memory into a form suitableor display. The audio/video buffer system operates under the control of a microprocessor which accepts commands from a remote command device or a connected host computer.