Hoya Corporation

Pentax Ricoh Imaging Company, Ltd.

Hirotaka Ueno

Kosei Kosako

Toshiaki Yamada

Yutaka Ohsawa

Shinichiro Sanada

Kazuhiro Matsumoto

An exposure control unit comprising a photometer, a designator, a first calculator, a first counter, a selector, a second calculator, a categorizer, and an exposure controller is provided. The photometer comprises a plurality of photometric zones. The designator designates the photometric zones one by one as a target zone. The first calculator calculates a first difference. The first counter counts a first determination number. The selector selects the target zone of which the first determination number is greater than a second threshold. The second calculator calculates a categorization value. The categorizer categorizes a target zone into low- or high-luminous zones. The exposure controller controls an exposure of the imaging apparatus on the basis of the partial value of light for one of the low- and high-luminous zones.

Exposure control unit and imaging apparatus

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

Hirotaka Ueno