Shutter device
AssigneeNikon Corporation
InventorMasanori Hasuda
Life of this patent
Estimating the term…
Abstract
A mechanism wherein the operation state of a shutter is detectable even with a diaphragm plate, without light shading blades being damaged, is disclosed. The mechanism includes a substrate, a cover plate, and a light blocking blade between the substrate and the cover plate. A diaphragm plate is between the light blocking blade and the substrate or the cover plate. A traveling state detection device uses detection holes to detect the traveling state of the light shading blade at a position corresponding to the traveling state detection device of the diaphragm plate.
Claims18
A shutter device, comprising:
- a substrate;
- a cover plate;
- a diaphragm plate between said substrate and said cover plate and including a first aperture which passes exposure light and a second aperture which defines a different area from the first aperture;
- a light blocking blade that travels between said substrate and said cover plate to alternatively expose and block said first aperture and said second aperture, said second aperture being of varying width in the direction of travel of said light blocking blade;
- and
- a travelling state detection device that uses a light beam wherein said second aperture is aligned with said travelling state detection device to allow said light beam to pass when said light blocking blade does not block said second aperture in order to detect the travelling state of said light blocking blade.
A shutter device, comprising:
- a substrate;
- a cover plate;
- a diaphragm plate between said substrate and said cover plate and including a first aperture which passes exposure light and a second aperture which defines a different area from the first aperture,
- a light blocking member which determines opening and closing of said shutter device and travels between said substrate and said cover plate to alternatively expose and block said first aperture and said second aperture, said second aperture being of varying width in the direction of travel of said light blocking member;
- and
- a travelling state detection device that detects the travelling state of said light blocking member using a light beam, wherein said second aperture is aligned with said travelling state detection device to allow said light beam to pass when the light blocking member does not block said second aperture.
A method of detecting the traveling state of a light blocking plate in a shutter device, comprising the steps of:
- emitting light toward an aperture in a diaphragm plate of said shutter device, said aperture does not define an exposure aperture and being of varying width in a direction of travel of said light blocking plate;
- allowing emitted light to pass through said aperture;
- reflecting emitted light passed through said aperture from a reflecting surface so that the emitted light passes through said aperture again;
- receiving the reflected light at a light receiver;
- and
- moving said light blocking plate in said first direction to block emitted light passing toward said aperture.
Dependencies are inferred from the claim text.