Nisca Corporation

Hiroaki Naganuma

Tetsuyuki Tohyama

Yosuke Sajiki

Katsura Nakajima

Tokuro Kusunoki

Yosuke Sasiki

A plurality of blade members is overlapped and disposed in the shape of scales in a ring-shaped board having an optical-axis aperture at the center, and is held from above by a driving ring so that each blade member performs open/close motion. At this point, an elastic member is disposed between the blade members and the board to press each blade member against the driving ring side, or an elastic member is disposed between the blade members and the driving ring to press the blade members against the board side, and in this state, the blade members are opened and closed.

Light quantity adjustment apparatus, lens unit and optical apparatus provided with the same

An imaging apparatus includes an imaging optical unit for focusing light on an image-forming plane; a solid-state image pickup unit for photo-electrically converting light; a data transfer unit for controlling transfer of image data; a substrate disposed in an imaging optical path of the imaging optical unit and provided with an exposure aperture; a shutter blade for closing the exposure aperture at a closed position and opening the exposure aperture at an open position; a shutter driving unit having an exciting coil for driving the shutter blade between the closed position and the open position; and a control unit for controlling the shutter driving unit. A blade restriction member is provided for restricting a motion of the shutter blade at the closed position. A shutter blade holding unit is provided for holding the shutter blade at the open position when no driving current is supplied to the exciting coil.

Imaging apparatus and light quantity regulating device used therein

An electromagnetic device includes a magnet rotor having a rotary shaft and a stator having an excitation coil configured to apply a rotation force to the rotor. The magnet rotor includes a hollow cylindrical permanent magnet, a rotary shaft disposed in a hollow space portion of the permanent magnet, and a driving arm that rotates around the rotary shaft integrally with the permanent magnet. The magnet and driving arm are reliably secured, not easily separated during use, and includes a structure that facilitates machining and assemble.

Magnet rotor and electromagnetically-driving device using the same, and optical apparatus with light quantity-control device

An electromagnetically-driving device has a rotor with a hollow, cylindrical permanent magnet; an inside yoke on an internal circumference side of the rotor; an outside yoke on an external circumference side of the rotor; and a coil for magnetically exciting the yokes. The outside yoke has a trough shape, and two opposed magnetic pole-guide pieces, between which magnetic poles of the permanent magnet are sandwiched. The rotor has a bearing portion in the internal circumference wall of the body, and the bearing portion engages a shaft portion of the inside yoke. When a magnetic field is generated by the coil, a rotation force is applied to the rotor, resulting in a structurally-simple magnetic circuit.

Electromagnetic-driving device and light quantity-control device incorporating the same

A light quantity adjusting device includes a ring-shaped base plate having an exposure aperture at a center thereof, a first light quantity adjusting blade arranged in the exposure aperture, a first drive device for opening/closing the first light quantity adjusting blade, a second light quantity adjusting blade arranged in the exposure aperture, and a second drive device for opening/closing the second light quantity adjusting blade. The first drive device includes a magnet rotor and an exciting coil formed in a ring shape, and a guiding member for inducing a magnetic field to a position facing a magnetic pole formed on a circumference side of the magnet rotor. The second drive device includes a magnet rotor, an exciting coil, and a guiding member for guiding a magnetic field to a position facing a magnetic pole formed on a circumference side of the magnet rotor.

Light quantity adjusting device and photographing device having the same

A light controller includes a substrate that has an optical path opening; at least a pair of blades that is reciprocally supported on the substrate and opens and closes the optical path opening; and a driver unit that drives the opening and closing of the pair of blades. The pair of blades is displaced movably on the substrate between an open position where the optical path opening is opened and a closed position where the optical path opening is closed by overlapping with each other. The driver unit and the pair of blades are connected for driving by a transmission unit, and the transmission unit transmits drive power such that one of the pair of blades can be moved at a higher speed than the other blade within a predetermined travel range between the open position and closed position.

Light controller and image pickup device including the same

A light controller includes a substrate having an optical path opening, a blade unit with a blade mounted on the substrate for opening and closing the optical path opening, a driver unit for driving the blade, and a stopper unit for restricting a movement of the blade between an open position and a closed position. The stopper unit includes a long hole formed in the blade and extending in a direction that the blade moves, and a stopper pin fitted into the long hole. The long hole is disposed at a position away from the optical path opening in an entire range that the blade moves. Accordingly, when the blade unit has a plurality of blades, it is necessary to arrange only the stopper pins having a number equal to the number of the blades on the substrate, thereby reducing a size of an apparatus.

An electromagnetic drive device includes a coil frame with a hollow tubular shape, a magnet rotor disposed in the coil frame to be rotatable through a rotational shaft, a transmission arm attached to the rotational shaft for outputting a rotation of the magnet rotor to an outside, and a coil wound around an outer periphery of the coil frame. The tubular coil frame is divided laterally in a direction perpendicular to the rotational shaft, and is formed of two bobbin members. The transmission arm is attached to the rotational shaft in a state approximately perpendicular to the rotational shaft. An opening is provided in one of the bobbin members in a peripheral side surface at a location different from a connection surface contacting the other of the bobbin members, so that the transmission arm protrudes to an outside of the coil frame through the opening.

Electromagnetic drive device and light quantity adjustment device using the same

An electromagnetic drive device includes a coil frame with a hollow tubular shape, a magnet rotor rotatably disposed in the coil frame through a rotational shaft, a transmission member for transmitting a rotation of the magnet rotor, and a coil wound around an outer periphery of the coil frame. The coil frame is formed of two coil frame halves divided vertically along the rotational shaft of the rotor, and the coil is wound in a direction crossing connection faces (joint faces) of the two coil frame halves on upper and lower end surfaces thereof.

An electromagnetic driving unit includes a rotor having a central shaft and formed of a permanent magnet with a hollow cylindrical shape; an inner yoke disposed on an inner circumferential side of the rotor; an outer yoke disposed on an outer circumferential side of the rotor; and a coil for exciting the inner yoke and outer yoke. The inner yoke has a shaft portion at an end portion thereof inserted into the rotor, and the shaft portion has a circular cross-section or an oval cross-section perpendicular to an axial direction of the shaft portion. The rotor has a bearing recess in an inner circumferential wall thereof, so that the shaft portion of the inner yoke slidably fits in the bearing recess.

Electromagnetic driving unit and light quantity regulating apparatus using the same

A light quantity control unit includes a base plate having an aperture forming an optical axis; a blade member for regulating a condition of the aperture; a coil and a magnet rotor polarized with two magnetic poles, formed on the base plate; and a pair of magnetic force inducing members. Each member has a base end part, and a leading end part extending from the base end part perpendicular to the optical axis and having an equal thickness throughout an entire length thereof. The leading end parts surround the magnet rotor at a middle area thereof and have magnetic poles for rotating the magnet rotor. A regulating device is formed at the base plate for regulating a rotation of the magnet rotor to swing at a predetermined angle between the magnetic poles formed in the magnetic force inducing members.

Light quantity controller and camera system including the same

A light quantity control apparatus includes a first base plate, at least one drive device mounted on the first base plate, a shutter blade mounted on the first base plate and engaging the drive device, an intermediate plate disposed above the shutter blade, a diaphragm blade disposed above the intermediate plate, a second base plate disposed above the diaphragm blade, and a protruding guide formed on the first base plate to support the shutter blade thereon. The protruding guide includes a closing region where the shutter blade completely closes the opening, an opening region where the shutter blade opens the opening, and an inclined surface formed at the closing region and/or the opening region. The inclined surface gradually narrowing a gap with respect to the intermediate plate so that a movement of the shutter blade is reduced by the inclined surface to prevent rebounding thereof.

Light quantity controller

A light amount control apparatus includes at least one blade member facing an optical axis aperture on a base plate and freely opening and closing the aperture, a rotating magnet rotor interconnected with the blade member to open and close the blade members, a coil and/or soft magnetic member to apply rotational torque to the magnet rotor, and a regulating device to regulate the movement of the magnet rotor within a prescribed angle. The regulating device is located to provide the magnetic rotor with an opening region and a closing region different from each other with respect to a neutral point so that a rotational torque acting on the magnet rotor differs by the regulating device to regulate the rotational movement of the at least one blade member in the opening and closing regions.

A high-performance exposure adjusting device for a camera has a magnet rotor united with an aperture member capable of steadily assuming three exposing positions according to the polarity of a direct current applied to a coil surrounding the rotor. When applying no current to the coil, the aperture member takes its magnetically neutral position to form a full aperture and is magnetically stabilized by a yoke surrounding the rotor. When the direct current of one polarity is applied to the coil, the aperture member rotates in one direction to form a first reduced aperture, and when the polarity of the current applied is reversed, a second reduced aperture is formed.

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Kofu, Japan

Hiroaki Naganuma