Other

Hiroshi Koike

Shoji Suzuki

Takeki Asakawa

An automatic diaphragm assembly for use in an optical or optoelectronic image pick-up device having lens systems, comprising diaphragm blades forming a variable aperture, at least one neutral-density filter element movable with one of the diaphragm blades, and an electromagnetic drive unit including a ring-shaped permanent magnet having locally magnetized pole portions alternately disposed circumferentially of the magnet and a ferromagnetic ring forming a circular air gap between the permanent magnet and the ferromagnetic ring.

Automatic diaphragm assembly

Herein disclosed is an electromagnetic rotary motion device including permanent magnets establishing a pair of spaced concentric and coextensive circular or semicircular air gaps and a rotor unit including armatures which are movable in a circular path in and along the spaced air gaps in response to an electric control signal impressed thereon. A typical application of the rotary motion device is a diaphragm-assisted exposure control arrangement of an optical instrument, such as for example as a still camera, a cinema motion camera or a television camera, wherein the diaphragm is driven by the rotor unit for providing a degree of exposure which is optimum for the brightness of an object to be photographed or televised.

Automatic-exposure control device for optical instruments

Herein disclosed is an electromagnetic rotary motion device including permanent magnets establishing a pair of spaced concentric and coextensive circular or semicircular air gaps and a rotor unit including armatures which are movable in a circular path in and along the spaced air gaps in response to an electric control signal impressed thereon. A typical application of the rotary motion device is a diaphragm-assisted exposure control arrangement of an optical instrument, such as for example, a still camera, a cinema motion camera or a television camera, wherein the diaphragm is driven by the rotor unit for providing a degree of exposure which is optimum for the brightness of an object to be photographed or televised.

Growing community of inventors

Tokyo, Japan

Hiroshi Koike