Seiko Koki Kabushiki Kaisha

Seikosha Co., Ltd.

Seiko Koki Kabushiki Kasiha

Nobuo Shinozaki

Masuo Ogihara

Yoichi Seki

Kozo Chimura

Kiyoshi Kitai

Shigeru Tagami

Tadashi Ishikawa

Kozo Sato

Hiroaki Ishida

Hiroshi Yamazaki

Yuzuru Takazawa

Hiroto Tsuyuki

Youichi Seki

Tadashi Nakagawa

Shinji Nagaoka

Hiroyuki Koizumi

Kouzo Sato

Hiroyuki Ishida

Hiroyuki Saito

Kazuo Akimoto

Seiichi Imano

Miyoshi Tanikawa

Atsushi Takami

Katsuhiko Matsushita

Masaki Tanaka

Yoichi Nakano

Yasuhiro Nishitani

Yusuru Takazawa

Musuo Ogihara

Michitake Nakazawa

Katauhito Niwa

Sigeru Tagami

An automatic focusing system for a camera comprises a motor rotatable in opposite directions, a drive member driven for rotation by the motor, a distance-setting member rotatable together with the drive member to place an objective lens in an initial position and movable to a predetermined forward position, and a holding mechanism for holding the distance-setting member in the predetermined forward position. The position of the drive member is identified at each monitoring point, and a position identification signal is generated. The sequence of movement of the distance-setting member is analyzed from a starting position to the predetermined forward position. The system further provides for preventing improper holding of the distance-setting member at its initial position.

Drive member sensing arrangement for an automatic focusing system of a

A program shutter for automatic exposure control including a forwardly/reversibly rotatable step motor for opening and closing a shutter to effect automatic exposure in the control circuit for controlling the operation of the step motor. The control circuit includes stored predetermined shutter mechanism characteristic values. The reversible stepping motor varies the lens aperture in response to a pulsed lens control signal generated by the control circuit. The corresponding value associated with each pulse is varied to be synchronized with and dependent on the shutter mechanism characteristic values and correspondingly varies the rotational power of the reversible stepping motor to overcome detrimental inherent shutter mechanism characteristics and to increase the response efficiency of the shutter.

Program shutter

A drive ring drivable by a stepping motor is normally urged by a spring to turn in one direction around a lens aperture. When not in use, the stepping motor is not subjected to the resilient force from the spring since the drive ring is locked against rotation by a ratchet wheel engaged by an engagement lever. The stepping motor is therefore not subjected to undue stresses and is prevented from malfunctioning. Consequently, focusing failures and exposure adjustment failures which could otherwise arise from malfunctioning of the stepping motor are prevented from occurring. In operation, a solenoid is energized to move the engagement lever out of engagement with the ratchet wheel, which is then freed to allow the drive ring to be turned by the stepping motor.

Motor-driven shutter for camera

An automatic focusing device for a camera having a lens, includes a camera lens focusing mechanism which adjusts the focus of the lens and which includes a rotatable driving ring, a coaxially mounted rotatable range ring and a spring which moves the range ring in correspondence with movement of the driving ring; a stepper motor which drives the driving ring so that the range ring adjusts the focus of the lens; a stepper motor driving circuit which controls the operation of the stepper motor; a home switch connected with the range ring and which determines the start of the focusing operation thereby; a shutter speed calculating circuit which calculates the shutter speed; a focusing arithmetic circuit which performs arithmetic operations for the focusing adjustment; an AF magnet sequence circuit which controls an electromagnet of the camera lens focusing mechanism to rotatably lock the range ring once the focusing operation has been completed; a main control circuit which includes software for controlling the shutter speed calculating circuit, the focusing arithmetic circuit and the AF magnet sequence circuit; and a forward/reverse rotation pulse delivering circuit which supplied respective pulse signals to the stepper motor driving circuit in response to the home switch, the shutter speed calculating circuit, the focusing arithmetic circuit and the AF magnet sequence circuit so as to ensure that the shutter is not operated when the camera lens focusing mechanism does not operate correctly.

Automatic focusing device for camera

A mechanism for opening and closing a shutter includes a rotatably mounted drive member, a motor operable to rotatably drive the drive member, an actuator for opening and closing the shutter when the drive member is rotated, and an operating arrangement between the drive member and the actuator operable to provide a gear driving operating relationship between the drive member and the actuator during one part rotation of the drive member and a non-driving relationship during another part rotation of the drive member.

Motor driven shutter

A shutter for a single lens reflex camera, comprises a drive gear rotatable in opposite directions by a motor and having a non-tooth portion, a control gear directly or indirectly engageable with the drive gear, shutter blades driven by the control gear to open and close a shutter opening, and a spring for constantly biasing the control gear in a direction to close the shutter opening. Upon rotation of the drive gear, the control gear is rotated to face the non-tooth portion of the drive gear whereby the shutter blades are moved under the action of the spring to close the shutter opening. When the control gear is brought into meshing engagement with the drive gear, the shutter blades are rendered operative to open and close the shutter opening.

Shutter for a single lens reflex camera

A lens driving device for an auto-focusing camera includes a lens driving member biased to move in one direction, a ratchet wheel having a plurality of teeth and rotatably associated with the lens driving member, a rockable retaining member having two pawl portions alternately engaging the teeth of the ratchet wheel, an electromagnet for controlling the rocking motions of the retaining member, and a control circuit for outputting a signal to the electromagnet to control the biased movement of the lens driving member.

Camera lens driving device

A camera having a lens shutter and a focal-plane shutter, includes a selector circuit for selecting either a lens shutter mode or a focal-plane shutter mode; a first driving device for controlling either the programmed exposure value of the lens shutter or the size of the aperture, the first driving device including a motor and an actuating member driven by the motor, the actuating member including a peripheral surface with a first cam for controlling the programmed exposure value of the lens shutter in response to forward rotation of the motor, and a second cam for controlling the size of the aperture in response to reverse rotation of the motor, the first cam having an inclination in a first direction and the second cam having a less steep inclination in an opposite direction; a pivotally mounted opening lever connecting the lens shutter to the actuating member, the lever defining a first arm and a second arm, the first arm in engagement with the actuating member and the second arm connected with the lens shutter, a first pin on the first arm which rides on the cams, and a second pin on the second arm to pivotally connect with shutter blades of the lens shutter; a spring biasing the first pin into engagement with the cams; a second driving device controlling the time of operation of the focal-plane shutter mode; and a sequential control circuit controlling the driving devices.

Camera

A device for activating shutter blades relative to a shutter opening and utilizing a control signal from an electronic circuit includes an electric motor rotatable clockwise and counterclockwise according to a control signal from the electronic circuit, a gear driven by the motor, the gear being located on one side of the shutter opening, fixed pivot axes located on an opposite side of the shutter opening, and a shutter operable device comprising shutter blades pivotable about the fixed pivot axes, the shutter operable device having gear teeth meshing with the gear such that the gear is operable to pivot the shutter blades clockwise and counterclockwise about fixed pivot axes to open and close the shutter opening.

Device for activating motor-driven shutter blades

A camera shutter has an automatic focusing lens operative when actuated to effect an automatic focusing operation. An actuating ring is normally placed in a non-operating region and momentarily shifted to an operating region during the automatic focusing operation. The actuating ring is sequentially displaceable in forward and reverse direction through the operating region to actuate the automatic focusing lens, and displaceable in the forward and reverse directions in the non-operating region without effecting actuation of the automatic focusing lens. A ratchet mechanism is coupled to the actuating ring for selectively locking and unlocking the actuating ring in the non-operating region in response to the displacement thereof in the forward and reverse directions. A bi-directionally rotatable stepping motor is connected to drive the actuating ring to displace the same in the forward and reverse directions.

A motor-driven shutter mechanism is provided with a lens protecting mechanism to protect the lens of a camera. The lens protecting mechanism consists of one or more lens guard members movable back and forth upon operation of the camera's motor-driven focussing and aperture setting mechanism to cover and uncover the lens. The lens guards are operably interconnected with the same motor which controls the focussing and aperture setting operations of the camera.

A motor driven shutter for a camera provided with a drive member moving in a lens operating area and an exposure operating area that are parted in one and the other, only one motor capable of reciprocal operation for operating said drive member, a range member for setting a lens position by interlocking with said drive member in said lens operating area, an urging member for urging said range member in a direction toward an initial position, an opening and closing member which has a sector open and close by interlocking with said drive member on said exposure operating area, locking means which locks said range member at a position corresponding to a focusing direction signal, and releasing means for releasing the locking of said range member by moving said drive member to the lens operating area again after exposure operation is completed.

Motor driven shutter for camera

A program shutter has a plurality of shutter sectors driven in opening and closing directions by a reversible stepping motor to define a lens aperture during an exposure operation. An arithmetic circuit calculates an exposure amount corresponding to the brightness of the object being photographed, and a counting circuit outputs a pulse count corresponding to the number of steps through which the stepping motor should be rotated based on the calculated exposure amount. A pulse circuit produces driving pulses equal in number to the number of steps determined by the counting circuit, and a time circuit determines the ON/OFF periods of the driving pulses based on the calculated exposure amount. The driving pulses are applied to the stepping motor through a driving circuit to accordingly drive the shutter sectors in the opening and closing directions during the exposure operation.

There is disclosed a program shutter for use in a camera. The program shutter consists of a shutter mechanism and a control portion. The shutter mechanism has sectors for defining an opening and a stepper motor for driving the sectors. The control portion produces pulses having pulse width conforming to the operating characteristic of the shutter mechanism. These pulses are used to step the motor forward or backward according to the exposure corresponding to the luminance of the subject.

In a program shutter using a stepping motor for opening and closing sectors, the stepping motor is composed of a 4-pole magnetized rotor and two sets of U-shaped stators and coils, the stators being each provided with a pair of leg portions which are formed with magnetic poles at end portions thereof in an opposed relation to the outer periphery of the rotor, the magnetic poles at the leg end portions of each stator being formed in a phase relation of 90.degree. with respect to the rotational center of the rotor, and one magnetic poles of the stators being disposed in proximity to each other so as to in a phase relation of 45.degree. with respect to the rotational center of the rotor.

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Yotsukaido, Japan

Nobuo Shinozaki