Lens unit wherein focal lens movement is selectively inhibited during zooming
US5281796A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 14, 1992 |
| Grant date | Jan 25, 1994 |
| Priority date | — |
| Expiry date | Jan 14, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B7/282
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical equipment comprises: a first lens for focusing and compensation for magnification variation; a second lens for magnification variation; position detection means for detecting positions of the first lens and the second lens; focus detection means for detecting a focus status; lens drive means for driving the first lens and the second lens; and control means for controlling the lens drive means in accordance with information from the position detection means and the focus detection means. The control means determines a drive range of the first lens in which a circle of confusion may be zero, in accordance with focal length information, and inhibits the first lens from being driven out of the range during the magnification variation of the second lens.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.