11. No other companies at NAB showed a helical scan VTR, so the VR-8000 stayed hidden. 12. To facilitate digital recording on existing Hi8 videocassettes the helical scan video head drum spins 2.5?faster. 13. This method was called quadrature scanning, as opposed to the helical scan transport used by later videotape formats. 14. A DDS tape drive uses helical scan recording, the same process used by a video cassette recorder ( VCR ). 15. A miniature " video cartridge " contained thirty minutes of Hi8 tape permanently loaded around a conventional helical scan record head. 16. His main research interests is in medical imaging, the development and introduction of helical scan CT was a particular focus. 17. The helical scan method reduces the X-ray dose to the patient required for a given resolution while scanning more quickly. 18. Subsequent videotape systems have used helical scan , where the video heads record diagonal tracks ( of complete fields ) onto the tape. 19. The helical scan VTR ( the HDV-100 ) used magnetic tape similar to 1 " type C videotape for analog recording. 20. This is known as a helical scan because the tape wraps around the circular drum at an angle, travelling up like a helix.
