Motor-driven auto-focusing system
US6055378A · kind A · utility
13Cited by
4References
14Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 11, 1998 |
| Grant date | Apr 25, 2000 |
| Priority date | — |
| Expiry date | Feb 11, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B7/08
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An auto-focusing device of a camera includes a photographic lens having a focusing lens group guided along an optical axis, a stepping motor for moving the focusing lens group along the optical axis to bring an object into focus; and a controller for controlling the stepping motor to rotate stepwise when the depth of focus is smaller than a predetermined value and for controlling the stepping motor to rotate the rotor by even-numbered steps when the depth of focus of the photographic lens is greater than the predetermined value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.