Optical Apparatus Including Diaphragm Device

• US 20070053684A1
• Filed: 08/15/2006
• Published: 03/08/2007
• Est. Priority Date: 09/08/2005
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Ogino, Shigeru, Iwasaki, Youichi
• Granted Patent: US 7,611,296 B2
• Time in Patent Office: Days
• US Class Current: 396/505
• CPC Class Codes: G03B 9/06 Two or more co-operating pivoted blades, e.g. iris type shutters functioning as diaphragms by limiting extent of opening movement G03B9/08
• CPC Class Codes: G03B 9/07 with means for presetting the diaphragm
• CPC Class Codes: G03B 9/14 Two separate members moving in opposite directions

Abstract

A lens apparatus includes a lens barrel, an image-capturing optical system, and a diaphragm device disposed in an optical path of the image-capturing optical system. The diaphragm device includes a plurality of diaphragm blades and an electroactive polymer actuator configured to move the plurality of diaphragm blades from a diaphragm-open state to a diaphragm-closed state and from a diaphragm-closed state to a diaphragm-open state.

Claims

1. A lens apparatus comprising:

a lens barrel;

an image-capturing optical system; and

a diaphragm device disposed in an optical path of the image-capturing optical system,

wherein the diaphragm device includes,

a plurality of diaphragm blades, and

an electroactive polymer actuator configured to move the plurality of diaphragm blades from a diaphragm-open state to a diaphragm-closed state and from a diaphragm-closed state to a diaphragm-open state.

2. The lens apparatus according to claim 1, wherein,

the electroactive polymer actuator is a single-phase electroactive polymer actuator, and

when the single-phase electroactive polymer actuator is in a non-conductive state, the plurality of diaphragm blades is kept in the diaphragm-closed state or the diaphragm-open state.

3. The lens apparatus according to claim 1, wherein,

the electroactive polymer actuator is a two-phase electroactive polymer actuator, and

when the two-phase electroactive polymer actuator is in a non-conductive state, the plurality of diaphragm blades is kept at an intermediate diaphragm position.

4. A camera comprising:

the lens apparatus according to claim 1;

and

a camera main body including an image-capturing device configured to receive light from the lens apparatus.