Patent GB-1435732-A (GB)
Title: Method of editing data-carrying web and a system for editing video tape
IPC: G11B27/024
Filed: 1973-05-14
Abstract: 1435732 Editing SPECTRA-VISION CORP 14 May 1973 [15 May 1972] 22793/73 Heading G5R In a method of editing a data-carrying web on a web-handling edit deck provided with a positive fixed-speed reverse drive for the web, the amount of roll-back of the web from a predetermined edit point necessary to allow the web to start from a stopped condition and reach full forward record speed at or by the edit point is determined, and a period of roll-back by the reverse drive is pre-set to achieve the necessary roll-back. Electronic editing of data from a transfer tape deck 14 to a magnetic tape on a video tape edit deck 10 is performed by first finding the required edit point on deck 10 tape and then pressing switch S1 momentarily thereby energizing self-latching relay 1RY to connect a tape drive capstan control 54 to reverse drive for roll-back and energize tape deck functions, e.g. reversing the tape reels, by control 55 and to start timer T1. When capacitor G1 charges via R1, R2 to a predetermined level, transistor Q1 turns on and SCR1 fires thereby momentarily energizing relay 2RY whereby relay 1RY is de-energized and stop circuit 62 is operated which together stop rollback. Energization of 2RY also energizes selflatching relay 3RY to thereby withdraw a pinch roller through actuator 58 and to apply take-up reel brakes 60. If a reset button S2 is operated 3RY is de-energized and a capacitor C4 discharges to energize relay 4RY for a short time to produce forward drive by means of control 64. Transfer deck 14 operation is similarly controlled by roll-back switch S4, reset switch S5, timer T2 and relays 7RY to 10RY. When both decks 10, 14 have rolled back and stopped, an editing operation is performed by operating roll switches S3A, S3B together thereby de-energizing relays 3RY, 9RY and energizing relays 4RY, 10RY to start forward tape drive on both decks as above. Switch S3A also momentarily operates relay 5RY to start timer T3 which is set to act via relay 6RY and control 66 to put edit deck 10 in the record mode just at the desired edit point. The method of the invention may be applied to an edit deck 10 which carries a video, audio, instrumentation or data tape and is associated with one or more transfer decks, each having controls as for deck 14 and carrying a magnetic tape, or a movie film or punched paper tape, for example. A switch permits any selected one of the transfer decks to be operational with the edit deck. The necessary roll-back to achieve operational speed at or by the edit point is determined for each deck in the system by trial and error adjustment by means of resistor R2 of the timing period of each timer, such as T1, T2. All of the timers are then set to the same period equal to the longest of the necessary roll-back periods of the individual decks whereafter no further adjustment is needed to ensure that the edit deck 10 and any selected transfer deck 14 will both have reached operational speed at or by the edit point when starting after roll-back, decks 10, 14 reaching the edit point simultaneously.