Automatic focusing apparatus for automatically matching focus in response to video signal based on extracted high frequency component of non-linear processed luminance signal
US5369436A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 29, 1993 |
| Grant date | Nov 29, 1994 |
| Priority date | — |
| Expiry date | Jan 29, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N23/673
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present invention relates to an automatic focusing apparatus which permits an automatic focusing operation to occur with a high accuracy irrespective of the luminance of an object being sensed. The automatic focusing apparatus includes a focus lens, an image sensor, a focus motor for changing the position of the focus lens, a Y/C separating circuit for separating a luminance signal Y from the output of the image sensor, a non-linear circuit for subjecting the separated luminance signal Y to a non-linear processing, a high pass filter (HPE) extracting a high frequency component from the output of the non-linear circuit, an integrating circuit for integrating the extracted high frequency component and an in-focus detecting circuit for controlling the position of the focus lens based on the result of integration.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.