Back to results
US 4,500,930 AGranted
Television signal standards conversion using a helical scan VTR
AssigneeRCA Corporation
InventorsKaarlo J. Hamalainen, Glenn A. Reitmeier
Life of this patent
Estimating the term…
Abstract
A television standards converter uses a VTR. The capstan speed is that of the video signal recorded on the tape, however, the drum speed is that of the standard to which it is desired to convert. Thus the reproduced signal has the original line rate but the new field rate. A line rate converter converts the reproduced signal to the new line rate, the signal is now totally in the new standard.
Claims2
A television standards conversion apparatus for changing the line and frame rates of a recorded NTSC television signal to the line and frame rates of a PAL signal standard comprising:
- a helical-scan video tape playback apparatus having a capstan which establishes the velocity at which the tape travels and at least one video head disposed on a headwheel which rotates at a velocity to scan the video heads at an angle across the direction of tape travel;
- control means for establishing the speed of said capstan in accordance with said NTSC television signal and for establishing the speed of said headwheel in accordance with said PAL signal standard to thereby convert the NTSC frame rate of the recorded television signal to said PAL standard;
- and
- line rate interpolation means for converting the line rate derived from the recorded NTSC television signal to the PAL standard which interpolation means uses coefficients predicated on simple fractional values which have a single digit numerator and a single digit denominator and establish a conversion ratio of 5/6.
1 more element
Dependencies are inferred from the claim text.