Imaging apparatus having electrooptic devices which comprise a variable focal length lens
US5071229A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 7, 1989 |
| Grant date | Dec 10, 1991 |
| Priority date | — |
| Expiry date | Aug 7, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/294
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An imaging apparatus is provided with a negative lens, a variable focal length lens unit including a material with an electrooptic effect, a light blocking unit, including the material with the electrooptic effect, capable of changing an aperture diameter, and a switch, interlocked with each other, capable of supplying electric power to the variable focal length lens unit and the light blocking unit which are arranged in order on an optical axis from an object side to an image side. When the switch is turned off, the variable focal length lens unit is set to bring an object at a far point into focus and the light blocking unit is set so that an aperture is determined by an aperture stop, while on the other hand, when the switch is turned on, the variable focal length lens unit is set so that an object at a near point is in focus and the light blocking unit is set to be smaller in aperture. Apertures different in size are determined by a plurality of annular transparent electrodes incorporated in the light blocking unit and configured concentrically. Thus the imaging apparatus can be constructed to be small or compact in size and is easy in manufacturing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.