Seiko Precision Inc.

Seikosha Co., Ltd.

Miyoshi Tanikawa

Kazuo Akimoto

Yoichi Nakano

Toshiaki Hirai

Hiroyuki Saito

Hiroshi Takahashi

Nobuo Shinozaki

Akira Ito

Tadashi Nakagawa

Hiroshi Yamazaki

Shigeru Tagami

Akihiro Ito

Chiaki Nemoto

Hiroto Tsuyuki

Katsuhiko Matsushita

Masaki Tanaka

Hiroyuki Koizumi

Nobuyuki Fukui

Hiroki Kusumi

A focal plane shutter for a camera has a synchronous contact member that produces less chattering than conventional synchronous contact members. One end of an opening electromagnet and one end of a closing electromagnet are separately connected to the higher-potential side of a power supply for a CPU in the camera, and the other ends of the electromagnets are grounded. An output circuit has an inverter circuit made up of a transistor and two resistors. A driver voltage for energizing the closing electromagnet is applied to the base of the transistor via a first resistor. The collector of the transistor is connected to the higher-potential side of the power supply via a second resistor. The emitter of the transistor is connected to the lower-potential side of the power supply. First and second voltage signals are produced from an output terminal on the side of the collector. One end of the synchronous contact member is connected to the lower-potential side of the power supply and the other end thereof is connected to the base of the transistor.

Focal plane shutter having synchronous contact member

A double-shielding type focal-plane shutter has a closing blade and an opening blade for closing and opening a shutter opening to perform an exposure operation. A closing lever and an opening lever drive the closing blade and the opening blade, respectively. The closing lever has a first closing lever and a second closing lever supported coaxial with each other for undergoing pivotal movement. The second closing lever has a drive portion at a first end thereof for driving the closing blade and an engagement portion at a second end thereof. A lock lever restricts movement of the closing lever. The lock lever has a first mating engagement portion for engaging the engagement portion of the second closing lever in the predetermined position of the closing lever, and a second mating engagement portion for engaging the engagement portion of the second closing lever short of the predetermined position thereof. A set lever undergoes movement to a set position to set the closing lever, the opening lever and the lock lever to predetermined positions.

Double-shielding type focal-plane shutter

A lens driving device for controlling the position of a lens setting member according to a distance to an object to be photographed has a lens barrel mounted to undergo movement in the direction of an optical axis, a lens setting member mounted to undergo rotation about the lens barrel and to move the lens barrel in the direction of the optical axis, a biasing spring for applying a biasing force for biasing the lens setting member in one direction, a ratchet engaging with the lens setting member to undergo rotation therewith, a retaining member having a pair of engaging pawls disposed to alternately engage with the ratchet to prevent rotation of the ratchet due to the biasing force of the biasing spring, an electromagnetic actuator for applying a first driving voltage for maintaining the retaining member in an engaged state and a second driving voltage for rocking the retaining member to alternately engage the pawls with the ratchet to cause the biasing spring to rotate the ratchet in a stepwise manner during periods when the ratchet is not engaged by either of the engaging pawls of the retaining member, and a driving ring for driving the lens barrel to return to an initial position by rotating the lens setting member to an initial position against the biasing force of the biasing spring and for performing at least one of an exposure operation and an aperture control operation. In the lens driving device, the first driving voltage of the electromagnetic actuator is lower than the second driving voltage such that a lower voltage is applied when the driving member is rotated and the lens setting member is at rest than when the lens setting member is not at rest.

Lens driving device

A lens driving device comprises a lens driving member mounted for rotation between an initial position and a preselected focus position, an urging member for urging the lens driving member in a first direction of rotation to control a rotational position of the lens driving member in accordance with the preselected focus position, and a ratchet operably rotatable with the lens driving member. A retaining member is mounted for back and forth rocking movement and has retaining portions for alternate engagement with the ratchet during back and forth rocking movement of the retaining member. A control mechanism controls the rocking movement of the retaining member. A holding member holds the lens driving member from rotation in a second direction of rotation opposite to the first direction of rotation when the lens driving member is in the initial position.

Lens driving device for auto-focus camera

A rocking motor comprises a coil wound around a hollow coil bobbin. A rotor is rotatably mounted at a position close to an end portion of the coil bobbin. The rotor has a center shaft and a permanent magnet and is magnetized with two poles such that the positions of the poles are located close to the coil and the magnetization angle is greater than 90 degrees but less than 180 degrees. The positions of the poles of the rotor and the coil are adjacent to one another so that a rotary torque can be efficiently obtained by a magnetic force generated by the coil. The rocking motor can generate a high power output with a relatively low power supply and its operational performance is not adversely affected by an external magnetic field.

Rocking motor

A lens driving device for a camera or the like drives a lens through a correct distance by the distance through which the lens is driven being corrected according to errors in mechanical parts; as a result it is not necessary for the mechanical parts to be made of high precision, and maintenance of molds used in their manufacture can therefore be made easy.

When a driving member is rotated counterclockwise by a single motor with a pair of sectors biased in the closing direction by a biasing spring, a first driving pin causes an operating lever to rotate clockwise. The pair of sectors pivot in opposite directions to each other in association with the driving lever to reach a first position where the sectors are fully open without overlapping the lens opening. When the driving member is rotated clockwise, a second driving pin also causes the operating lever to rotate clockwise. The pair of sectors pivot in opposite directions to each other to reach a second position, that is, a half-open position where an opening smaller than the lens opening is obtained. At this time, The second driving pin abuts on a part of one sector to restrain the displacement of the driving member. Accordingly, the driving member is prevented from overrunning, and no hunting occurs.

Shutter for camera

A drive mechanism for a camera having a lens including a drive member, a motor for driving the drive member in a clockwise and a counterclockwise direction, a range setting device operated by the drive member operable to effect movement of a lens member to a plurality of positions corresponding to a plurality of focused positions of the lens when the drive member is rotated by the motor, an exposure actuation device operable upon actuation to effect exposure operation of the camera, and actuating cams on the drive member for actuating the exposure actuation device as the range setting device maintains a focused position of the lens.

Shutter with lens drive mechanism

Apparatus for performing an automatic focus/exposure operation for a camera includes a drive member driven by a motor, a distance member for driving a lens focusing mechanism during a lens focusing operation in correspondence with movement of the drive member in a first direction, a retaining pawl for engaging the distance member means to prevent reverse movement of the distance member means upon completion of the lens focusing operation, and a blade opening/closing mechanism for opening blades during an exposure operation when the drive member moves in a second direction which is opposite to the first direction of the focusing operation, the blade opening/closing mechanism shifting the exposure operation quickly upon completion of the lens focusing operation.

Automatic focus/exposure operation apparatus for camera

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.

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Yotsukaido, Japan

Miyoshi Tanikawa