Automatic focusing device for a video camera
US4621292A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 16, 1984 |
| Grant date | Nov 4, 1986 |
| Priority date | — |
| Expiry date | Oct 16, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N23/671
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An automatic focusing device for a video camera includes a projector for projecting an infrared ray used for measuring distances and a converging lens for focusing reflected infrared ray light from an object whose distance is to be measured. A light spot detector and a computer are provided for determining whether the video camera is in focus. A lens encoder is utilized to determine the position of a focusing lens and a lens driving unit moves the position of a photographic lens used for photographing the object forwardly or backwardly in dependence upon outputs from the lens encoder and computer so as to automatically focus the video camera in response to the infrared rays reflected from the object to be photographed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.