Digital on video recording and playback system

• US 4,419,699 A
• Filed: 11/16/1981
• Issued: 12/06/1983
• Est. Priority Date: 10/12/1979
• Status: Expired due to Fees

• Current Assignee: RCA Corporation
• Original Assignee: RCA Corporation
• Inventors: Dieterich, Charles B., Christopher, Todd J.
• Primary Examiner(s): PSITOS, ARISTOTELIS
• Application Number:
  US06/322,061
• Time in Patent Office: 750 Days
• Field of Search: 358/128.5, 358/128.6, 358/145, 358/147, 358/21 V, 358/4, 358/34, 358/37, 358/171, 358/176, 358/178, 358/166, 358/327, 358/340, 358/342, 358/335, 330/11
• US Class Current: 386/216
• CPC Class Codes: G11B 2220/20 Disc-shaped record carriers
• CPC Class Codes: G11B 27/105 of operating discs
• CPC Class Codes: G11B 27/3054 Vertical Interval Time code [VITC]
• CPC Class Codes: G11B 27/36 Monitoring, i.e. supervising the progress of recording or reproducing for digital recording G11B20/00 and s.gr.; for monitoring, testing or measuring of TV recorders of the type covered by H04N5/76 and subgroups, see H04N17/06
• CPC Class Codes: H04N 9/8233 the additional signal being a character code signal
• CPC Class Codes: H04N 9/87 Regeneration of colour television signals H04N9/80 takes precedence

Abstract

In a system for recording digital information on a video disc and for playback of the digital information therefrom, the digital data is recorded in synchronism with the color subcarrier signal on a horizontal line adjacent to a constant luminance line. This arrangement facilitates a video disc player having a simple, efficient, video-to-digital interface for separating the prerecorded digital information from the video signal. The player apparatus is responsive to the color subcarrier signal and the chrominance-related output signal of a comb filter, both of which are normally available during video signal processing. Prerecorded digital information representing field number and type of program content is used by a microprocessor controller to provide player features such as locked groove detection, program elapsed time display, and end of program indication. The microprocessor-to-player interface includes means responsive to the panel controls to operate the player mechanism and panel displays in accordance with the desired player features.

Claims

1. A microprocessor-controlled video disc player for playing back a video disc having recorded thereon a video signal including a subcarrier signal of a prescribed frequency, said video signal further including a digital information signal encoded during a horizontal line thereof, said digital information signal being synchronized with said subcarrier signal, and a further horizontal line having a signal value corresponding to a constant luminance level, said further horizontal line always being adjacent the horizontal line encoded with the digital information, said video disc player comprising:

signal pickup circuitry for recovering recorded signal from the disc record;

video processing circuitry responsive to the recovered signal including,

(a) means responsive to said subcarrier signal for generating a clock signal synchronous therewith, and having a cyclic rate equal to said prescribed frequency,

(b) means for subtracting one of said horizontal line encoded with digital information and said further horizontal line from the other of said horizontal line encoded with digital information and said further horizontal line to generate a self DC-referenced difference signal corresponding to said recorded digital information signal;

an information buffer responsive to said clock signal for synchronously detecting said recorded self-referenced digital information signal, and storing said digital information signal for use by the microprocessor; and

wherein said microprocessor is firmware programmed to generate a gating time interval responsive to said clock signal and said digital information signal and generating a control pulse at the end of said timing interval for enabling said information buffer to receive successive digital information signals.

2. The video disc player set forth in claim 1 wherein the means for subtracting one of said horizontal lines from the other comprises a comb filter.