Method and apparatus for film weave correction
US4823204A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 18, 1987 |
| Grant date | Apr 18, 1989 |
| Priority date | — |
| Expiry date | Jun 18, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2201/04791
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for correction of both horizontal and vertical film weave is disclosed in connection with continuous motion type moving beam recorder or playback devices such as electron beam or laser beam recorders or flying spot scanner or line scan telecines. Weave correction is accomplished by scanning the sprocket hole of the film and generating a correction signal to compensate for the film weave. The film weave is corrected by electronic weave correction as opposed to mechanical pin registration means. The sprocket hole is scanned in the vertical direction to locate the upper and lower edges of the sprocket hole, and then to position the beam in the vertical center of the hole and for determination of vertical weave of the film. The sprocket hole is then scanned in the hozizontal direction, for determination of the horizontal weave of the film. In a film to tape transfer system the edge position of the sprocket hole is advantageously determined by comparing the actual detected signal with a fast peak detector signal set at 90% of the actual signal level. Provision is made for setting windows for acceptable weave corrections signals such that if the detected error exce…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.