Canon Kabushiki Kaisha

Canon Denshi Kabushiki Kaisha

Katumi Yoshida

Shigeru Yoshida

Hiroshi Yamamoto

Ryuji Suzuki

Tadashi Arai

Masachika Nishimura

Hiroaki Seino

Takehiko Ando

Hiroshi Yamomoto

A motor-driven type exposure adjusting device, such as a diaphragm-shutter device, adapted for a lens incorporating camera, an interchangeable lens, or the like. In the adjusting device, a rotary member has an optical path hole formed in a central portion thereof and is arranged to control the opening and closing actions of a plurality of light shielding blades. A stepping motor servers as a drive source for the rotation of the roatary member and is disposed outside of the optical path hole, and an aperture position detecting means detects a boundary between a given maximum aperture position defined by the light shielding blades and a stopped-down aperture position of the optical path hole. The aperture position of the optical path hole is detected through the rotating angle position of a rotary wheel to which the rotation output of the rotor shaft of the stepping motor is transmitted.

Motor driven exposure adjusting device

A diaphragm control device for use in an interchangeable lens of a single lens reflex camera. A motor for driving diaphragm blades includes a coil, a rotor, and a stator which are arranged in a diaphragm device comprising a ring-shaped disc with diaphragm blades that open and close an optical path hole provided in a central portion thereof. The rotor and stator are disposed on the surface of a ring-shaped disc between the periphery of the opening and the outer periphery of the diaphragm device. The shaft of the rotor, the coil, and the stator are positioned in parallel with the axis of the opening, and the rotor and the coil are arranged in a parallel arcuate row on the surface of the ring-shaped disc. The present invention provides a diaphragm device which, when installed in the lens barrel, has reduced size and makes it possible to drive the diaphragm blades with high torque.

Diaphragm control device for interchangeable lens

Growing community of inventors

Saitama, Japan

Katumi Yoshida