Automatic focusing apparatus
US4975726A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 18, 1988 |
| Grant date | Dec 4, 1990 |
| Priority date | — |
| Expiry date | Nov 18, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N23/673
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An automatic focusing apparatus uses an image signal provided by a lens system of a camera for focusing the taking lens system. The apparatus includes: a lens system; a pickup element for converting the optical image of an object formed by the lens system into a corresponding electric signal; a signal processing circuit which processes the output signal of the pickup element to provide two focus signals corresponding to the respective quantities of horizontal and vertical high-frequency components of the object in an image plane; a lens driving mechanism for driving the lens system; and a control unit for controlling the lens driving mechanism according to the two focus signals to focus the lens system. Preferably, the apparatus further includes: a detector for detecting the condition of the object or the viewing conditions and a changeover circuit for changing over the characteristics of the signal processing circuit on the basis of the output of the detector. The additional use of information about the vertical direction enables the focusing of the lens system for any object including a horizontal line. Since the characteristics of the signal processing circuit are changed select…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.