High-Speed Video Tape Duplication Using Contact Printing

A system for duplicating prerecorded video tapes at high speed has been developed. The system employs contact printing and can handle half-inch video tapes for home-use VCRs. In contact printing, the mother tape must have three times higher coercivity than that of a copy tape with a coercivity of 650 Oersted. For this purpose, a metal tape was developed whose coercivity is approximately 2000 Oersted. To attain a duplicating speed of more than one hundred times the normal speed, the "Transfer Drum Method" has been devised. Mirror mother and copy tapes are wrapped around the transfer drum, so that the coated surfaces of both tapes face each other. By means of air pressure the tapes are pressed firmly together and a bias transfer field is applied using a stationary transfer bias head; these conditions allow a mirror image pattern of mother tape to be transferred at the same time. The system can handle either pancake or cassette copy tapes, a feature which decreases duplication cost and increases operational reliability.