Canon Kabushiki Kaisha

Taizo Mitani

Takashi Isobe

Shigeru Hashimoto

Katsumi Tanaka

Akiyasu Sumi

Masao Aoyagi

Takehiko Kiyohara

Syohei Ohtaki

Mithutoshi Ogiso

An interchangeable lens assembly for a camera is formed with a bayonet coupling affixed to the lens barrel with both being rotatable relative to an adapter shell. Upon attachment of the lens assembly to a camera housing, a detent pin is retracted from a fitted hole found in a radial flange of the adapter shell and the lens barrel is thereby rendered rotatable together with the bayonet coupling with reference to both the adapter shell and the camera housing while the adapter shell is held stationary relative to the camera housing during mounting and dismounting of the lens assembly.

Lens assembly coupling device for camera system

An interchangeable lens assembly for a camera including a lens barrel having a diaphragm mechanism mounted therewith, a bayonet coupling mechanism fixed on the lens barrel and adapted to be brought into engagement with a complementary coupling mechanism on the camera for releasably mounting the lens assembly in operative position on the camera, an adapter shell mounted on the lens barrel in rotative relationship relative thereto for establishing predetermined relative positioning between the interchangeable lens assembly and the camera, and a retainer mechanism adapted to be interposed between the adapter shell and the camera for retaining the adapter shell in fixed rotative position relative to the camera during mounting and dismounting of the interchangeable lens assembly. The lens assembly also includes a diaphragm presetting mechanism for transmitting signals representative of a diaphragm aperture between the lens assembly and the camera. Since coupling and decoupling of the lens assembly is performed by rotating the lens barrel relative to the camera housing, while the adapter shell remains stationary, the diaphragm presetting mechanism is provided with a device for assuring that an arm extending between the camera and the lens assembly is located in a predetermined angular position relative to a slot in the stationary adapter shell before and after the unit is attached to and detached from the camera housing despite the fact that the range of rotative tightening movement of the tube may be larger or smaller than that of movement of the arm. Thus the operator is able to detach the unit with the position of the diaphragm ring left unchanged.

Mounting for interchangeable camera lens assembly with diaphragm means

In the photographic apparatus disclosed a long-exposure adapter is attached to a camera to lengthen the camera's shutter operating times. When the camera's light sensing system responds to a low illumination by setting the shutter time to B (infinite time), an operator shifts to the long exposure range. The adapter then responds to a high sensitivity sensor and a long exposure timing device in the adapter is adjusted for the low illumination. The adapter then operates the shutter release of the camera, which has been set to B to obtain long exposures.

Photographing apparatus

Growing community of inventors

Kanagawa, Japan

Taizo Mitani