Seiko Koki Kabushiki Kaisha

Shogo Kato

Kiyoshi Kitai

Yukio Morino

Yukio Nakamura

Shinji Nagaoka

Ichiro Nemoto

Masanori Watanabe

Tomoo Yonemoto

Masaru Kobayashi

An electromagnetic shutter release device is provided with an electromagnet including an armature. A control circuit including two delay circuits are connected to the electromagnet for energizing same for a first period upon the initiation of the shutter release operation and thereafter energizing same for a second period upon the initiation of the exposure operation. The armature is mounted for movement to a first position during the first period, movement into a second position between the first and second periods and maintaining of same in the second position in the second period and into a third position after the second period. The movement of the armature from the first to the second position initiates the exposure operation and the movement of the armature from the second to the third position initiates the aperture closing operation which in turn begins the energization of the electromagnet during the second period whereupon the armature is maintained in position. As a result, a device is obtained which is technically and economically advantageous since it uses a single electromagnetic assembly for two purposes.

Electromagnetic shutter release device for cameras

A flash changeover device for a shutter is operative when the exposure operation is performed by cancelling the retention on a shutter blade control in the charged state by the operation of an actuating member which has previously been charged and is actuated by a shutter release operation. The device includes a flash system changeover member, a switching member, a synchronizing switch and wherein the switching member is oscillatably mounted on the changeover member so as to close the synchronizing switch in connection with the operation of the actuating member when the flash system changeover member is set to a first position and to close the synchronizing switch in connection with the shutter blade opening operation of the shutter blade control member when the flash system changeover member is set at a second position. The synchronizing switch has contacts having relative positions which are independent of the position of the changeover member when the synchronizing switch is in the open state.

Flash system changeover device for the shutter of camera

In an automatic focusing camera, a shutter blade control device comprises a first movable actuating member for controlling a focusing member, a second movable actuating member for controlling a shutter blade control member and a delay device mounted on one of the two actuating members and engaged with the other actuating member to regulate the movement of the two actuating members with respect to each other. In operation, one actuating member is held stationary and the movement of the other is under the action of the delay device. Thereafter, the other actuating member is stationary and the one actuating member moves under the action of the delay device.

Shutter blade control device for automatic focusing camera

In an automatic focusing camera having a shutter control member for controlling the shutter mechanism and a focusing member for regulating the position of the camera lens, an actuating member is provided for controlling the focusing member and the shutter control member. The actuating member is a single slidably mounted element which is movable between a charged position and a rest position and is biased into the rest position. The actuating member actuates the focusing member in the initial stage of movement from the charged position to the rest position and actuates the shutter control member in the final stage of the movement to the rest position.

Shutter control device for automatic focusing camera

An electromagnetic shutter controlling device releases the shutter to start exposure when the device is energized and completes exposure when the device is deenergized. The electromagnetic shutter controlling device is constituted of a shutter blade for opening and closing the shutter aperture, a first driving spring for closing or releasing the shutter blade, an electrical delay circuit for controlling exposure time, an electromagnetic device including an armature attracted by the magnetic force of the electromagnetic device and being connected to the electrical delay circuit, a second driving spring which is strained by the attraction of the armature so as to release or close the shutter blade when it is released, and a retaining member for keeping the shutter blade at the aperture closing position until it is actuated to release the shutter blade by the attraction of the armature. The armature is actuated by the magnetic attraction of the electromagnetic device first to strain the second driving spring, then to release the stop restraining the shutter blade so that exposure is started. The electromagnetic device is deenergized after a predetermined period of exposure time controlled by the delay circuit to complete the exposure by releasing the armature to return to the resting position and by actuating the previously strained driving spring to drive the shutter blade to close the shutter aperture. A trigger switch is closed simultaneously with the attraction of the armature to energize the delay circuit.

Electromagnetic shutter controlling device for camera

An automatic focusing camera capable of automatically focusing the photographic lens thereof by a system actuated by a signal produced by a focus detection circuit when the distance between the object to be photographed by the camera is detected includes an exposure control device comprising an exposure control circuit and an electromagnet. A photographic lens focusing member is movable in response to the shutter release operation and is stopped in response to the magnetizing of the electromagnet. An exposure device is actuated to open to start the exposure after the photographic lens focusing member is stopped, and is closed in response to the demagnetizing of the electromagnet which occurs upon the receipt thereof of the exposure completion signal generated by the exposure control circuit. In this way, a common electromagnet is used for both the focus control and the exposure control to simplify the construction of the camera and to reduce the cost thereof.

Exposure control device for automatic focusing camera

In an electronic program shutter having sectoral shutter blades functioning in varying both the aperture and the exposure time corresponding to the brightness of the field, a synchronizing device according to the present invention comprises a sectoral shutter blade control lever which is oscillatable and capable of opening and closing the sectoral shutter blades and is normally urged in the direction that the sectoral shutter blades keep the aperture closed, a driving member which travels in one direction according to the shutter release operation, an actuating lever rotatable about a shaft fitted on the driving member and interlocked with the sectoral shutter blade control lever, an electromagnet which is unmagnetized at an exposure completion signal given by an exposure control circuit, and an armature which operates a flash light switch and cancels the engagement between the sectoral shutter blade control lever and the actuating lever when the electromagnet is unmagnetized and the attraction by the electromagnet is cancelled.

Synchronizing device for electronic program shutter

In a self-timer starting its operation by releasing blocking of an anchor or intermediate gear blocking member, a self-timer featured in that there are provided a blocking lever which is able to move said anchor or intermediate gear to blocking position and a locking lever capable of locking said blocking lever in a releasing position, said locking lever being pushed by the intermediate gear shaft removable along a guide groove to set free the engagement of a gear train, and the blocking of the anchor or intermediate gear being so arranged as to be made by releasing locking of the blocking lever, thus enabling a driving shaft to be reset at any desired position during operation of said self-timer.

Resettable self-timer

A single-lens reflex camera shutter having an operating ring driven in one direction by a gear-rack and pinion combination. The operating ring actuates the diaphragm and shutter blades and is stopped by a stop lever during the taking of an exposure. The stop lever is locked during the taking of an exposure by a signal lever that signals the taking of an exposure and is released upon completion of an exposure to allow the operating ring to continue in its travel and carry out opening of the shutter and opening of the diaphragm blades.

Lens shutter actuating device for quick-return type single-lens reflex

A lens shutter for a quick-return single-lens reflex camera in which the diaphragm blades and shutter blades are operated by an operating ring driven rotationally in opposite directions by a driving device. The driving device has a pair of axially biased rods that coact to sequence their travel axially in two directions for driving the operating ring through gear racks on one of the rods and a driving ring coupled to the operating ring. A pinion meshes with both gear racks. A stop lever releasably locked by a signal lever stops the operating ring temporarily during taking of an exposure and the signal lever releases the stop lever at the end of an exposure which it signals or indicates. A cocking mechanism comprising a plurality of levers cocks the operating rods to cock the shutter.

Driving device of lens shutter of single-lens reflex camera

An exposure time control circuit for an electric shutter of a camera includes a monolithic IC having input circuitry in the form of a transistorized differential amplifier having two input terminals. A time-constant circuit develops a timing signal proportional to the brightness of the object field and applies it to one input terminal and a reference voltage signal is applied to the other input terminal to control the exposure timing. In order to enable varying the reference voltage through a wide range so that the input terminals can also be used for introducing other exposure information variables, such as input signals representative of the F-value, film sensitivity, etc., a transistor is connected between the IC and the source of electric power.

Exposure time control circuit of shutter of a camera

A warning light display device for an electric shutter of a camera having an exposure time control circuit for determining the exposure time of an electric shutter in dependence upon at least the brightness of an object being photographed. A warning display circuit is connected with the exposure time control circuit and has a control transistor that receives the output of the exposure time control circuit and controls the visual indication of three stages of the warning display circuit comprising light emitting diodes that indicate adequate and inadequate exposure conditions. A reference time generating circuit is provided in the warning display circuit for developing a signal representative of a predetermined time duration and a control transistor thereof controls energization of the three stages as a function of a comparison of the exposure time duration developed by the exposure time control circuit and the predetermined time duration developed by the reference time generating circuit.

Growing community of inventors

Yotsukaido, Japan

Shogo Kato