Time division multiplex video recorder with enhanced vertical chrominance sampling rate
US4752830A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 29, 1986 |
| Grant date | Jun 21, 1988 |
| Priority date | — |
| Expiry date | Sep 29, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/825
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A time division multiplex video recording system records every other one of the two chrominance signals (I and Q or R-Y and B-Y) of successive video fields and records the luminance signal (Y) of every field in separate time division segments. During odd fields, it records the luminance signal and the I chrominance signal of every horizontal line and during even fields it records the luminance signal with the Q chrominance signal of every horizontal line. During playback, a field store memory receives and stores the previously recorded chrominance signal of each field for repetition during the next to fill in for the unrecorded chrominance signal. In another embodiment, a helical scan four-head video playback system repeats every field during playback of the next field by playing back the adjacent tape tracks of both fields simultaneously, to fill in for the unrecorded chrominance signal (thereby eliminating the requirement for a field store memory). The invention represents a dramatic improvement because it achieves at least twice the vertical chrominance sampling rate of known time division multiplex video recording techniques.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.