Magnetic recording at video cassette recorder for home use
Yuma Shiraishi, Akira Hirota · IEEE Transactions on Magnetics · 1978
A 2-head helical scan type, home-use video cassette recorder was developed and this new system was named "VHS". The basic tape pattern enables variable speed playback, permitting noise-free still-frame and double-speed playback. For equipment built to the NTSC standard, to attain high-density recording, various techniques including a 90° phase-shift color signal processing technique, double limiter circuit and burst signal emphasis circuit were employed. An adequate color signal processing method was developed for the PAL and SECAM television standards.