Lap and dissolve in video cameras with VTR
US4325088A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 24, 1980 |
| Grant date | Apr 13, 1982 |
| Priority date | — |
| Expiry date | Mar 24, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B27/10
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A video camera is provided with means for producing lap and/or dissolve effects between successively recorded scenes. Means are provided for controlling the level of AC bias accompanying the video signals applied to a magnetic recording head. A dissolve effect is achieved by gradually decreasing the level of such bias at the end of a recorded scene. A lap effect is achieved by gradually increasing the bias level at the beginning of a new scene. A simultaneous lap and dissolve effect is achieved by performing the individual lap and dissolve effects on the same segment of tape. To do this, the tape drive is reversed at the end of each scene to position the dissolved portion of the scene upstream of the magnetic recording head. Upon recording a new scene while gradually increasing the level of AC bias at the beginning thereof, a simultaneous lap and dissolve effect is achieved automatically.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.