Hoya Corporation

Ricoh Imaging Company, Ltd.

Shinichiro Sanada

Kosei Kosako

Toshiaki Yamada

Yutaka Ohsawa

Hirotaka Ueno

Masahiro Inazuka

A movable-mirror drive mechanism of a camera includes a main mirror held by a main-mirror holding frame rotatable between a viewfinder light-guiding position and a retracted position; a sub-mirror held by a sub-mirror holding frame that is rotatably supported by the main-mirror holding frame, wherein the sub-mirror holding frame is positioned in a jutting-out position when the main mirror is in the viewfinder light-guiding position, and the sub-mirror holding frame is retracted with the main mirror when the main mirror is in the retracted position; and a vibration control member which rotates in association with rotation of the main-mirror holding frame and holds the sub-mirror holding frame in the jutting-out position to prevent the sub-mirror holding frame from rotating toward the sub-mirror retracted position when the main mirror rotates to the viewfinder light-guiding position.

Drive mechanism for movable mirror of camera

A control apparatus for a cam drive mechanism comprising a motor, a driven member having a cam follower, a rotatable cam which is rotated by the motor, and a cam surface on the cam, the cam surface including a pressing area which is inclined so as to press the cam follower against a load when the cam is rotated by the motor and a recessed area which is inclined in a direction opposite to the inclination direction of said pressing area. A controller rotates the cam by the motor in a single direction, and changes a rotational speed of the motor between when the cam is positioned at a first rotational position at which the recessed area and the cam follower face each other, and when the cam is positioned at a second rotational position at which the pressing area and the cam follower face each other.

Camera, control apparatus for cam drive mechanism and control method for cam drive mechanism

A camera having a mirror drive mechanism, for rotating a movable mirror, includes a slider supported on a side of the movable mirror to be linearly movable in a vertical direction corresponding to an up-and-down rotation of the movable mirror, the slider including a cam follower; an end-face cam member positioned above a mirror up-and-down pivot, about which the movable mirror pivots, to be rotatable about a vertical rotational shaft, a cam follower provided on the slider is in contact with the end-face cam member so that the end-face cam member changes a vertical position of the slider via an end-face cam and the cam follower by rotating; and an end-face cam driver. A control apparatus for a cam drive mechanism and a method of controlling a cam drive mechanism are also provided.

A diaphragm control apparatus is provided in a camera body, in which a controller drives a stepping motor to move the slider away from an origin position, thereafter drives the stepping motor in the opposite direction toward the origin position, and thereafter detects the slider position after holding the stepping motor for a first waiting time upon a distance from the slider to the origin position becoming less than slider-moving distance for one step of the stepping motor. The controller causes the stepping motor to enter a free state upon a lapse of the first waiting time and detects the slider position upon a lapse of a second waiting time to set an initial excitation pattern from a difference between the slider position detected during the first waiting time and the slider position detected in the free state thereof and from the moving distance of the slider.

Diaphragm control apparatus of interchangeable lens camera

A diaphragm control apparatus in a camera body includes a stepping motor, a lead screw thereof, wherein a slider is driven by the lead screw, a position detector, and a controller. When the stepping motor is in a free state, the slider allows a diaphragm operatively-associated rod to move to an initial position. The controller detects the slider origin position when the stepping motor is in the free state and drives the stepping motor stepwise to move the slider away from the origin position against a biasing force of a resilient biaser, and drives the stepping motor stepwise to move the slider toward the origin position while detecting the slider position; and sets an initial excitation pattern of the stepping motor upon a distance from the detected slider position to the origin position becoming less than a slider moving distance for one step of the stepping motor.

A diaphragm control apparatus in a camera body includes a stepping motor; a lead screw thereof, wherein a slider is driven by the lead screw; a position detector; and a controller. When driving the stepping motor by a predetermined number of steps in a direction to move the slider away from an origin position, the controller detects the slider position before driving the stepping motor stepwise as the origin position via the position detector, and thereafter detects a stepping position of the slider to compare the stepping position with the origin position each time the stepping motor is driven by one step, and counts the number of steps based from the moment at which the stepping position of the slider exceeds a predetermined position in the direction to move the slider away from the origin position against the biasing force of the resilient biaser.

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Saitama, Japan

Shinichiro Sanada