Abstract: An aperture apparatus includes a substrate having a lens opening, a first aperture sector having a first aperture opening, a second aperture sector having a second aperture opening, and a drive pin that is engaged in cam openings respectively formed in the first aperture sector and in the second aperture sector and that swings the first aperture sector and the second aperture sector. The first aperture sector and the second aperture sector are located in receding positions from the lens opening, when the drive pin is in an initial position. The cam openings include a swing region and a non-swing region, the swing region guiding a corresponding sector to the lens opening as the drive pin moves from the initial position, the non-swing region retaining the other sector in the receding position, when one of the first aperture sector and the second aperture sector is guided to the lens opening.

Abstract: A sector drive mechanism includes an electromagnetic actuator including a rotor having four polarities, a C-shaped stator, and a current control portion that controls current applied to a first coil and a second coil, the C-shaped stator including a first magnetic pole magnetically excited by the first coil, a second magnetic pole magnetically excited by the second coil, and a third magnetic pole magnetically excited by the first coil and the second coil, and sectors that are connected to the electromagnetic actuator to open and close a shutter opening provided in a substrate. The first coil and the second coil are driven to close the shutter opening with a fewer number of pulses applied from the current control portion than the number of the pulses to open the shutter opening.

Abstract: A lens barrier module including a substrate in which an opening is defined, sectors opening the opening when picking up an image and closing the opening when not picking up the image, and a motor provided at the substrate and driving the sectors.

Abstract: A lens barrier apparatus includes: swingable sectors opening and closing an opening, a swinging member swinging the sectors; and a drive portion driving the swinging member, and one ends of bias members biasing the sectors in a closing direction are provided at the sectors, the other ends of the bias members are provided at the swinging member, and when the sectors are at a closed position closing the opening, the swinging member is driven in the closing direction of the sectors against biasing forces of the bias members.

Abstract: A step motor includes a rotor having four magnetic poles, a first magnetic pole magnetically excited by a first coil, a second magnetic pole magnetically excited by a second coil, and a third magnetic pole magnetically excited by the first coil and the second coil. A gap D between the third magnetic pole and the rotor is larger than a gap d between the first magnetic pole and the rotor and the gap d between the second magnetic pole and the rotor, so that a magnetic attraction is generated between a pole of the rotor and the first magnetic pole and between another pole of the rotor and the second magnetic pole. With this step motor applied to a shutter driving mechanism of a camera, it is possible to surely retain the shutter state even when the current does not flow.

Abstract: An aperture apparatus includes a substrate having a lens opening, a first aperture sector having a first aperture opening, a second aperture sector having a second aperture opening, and a drive pin that is engaged in cam openings respectively formed in the first aperture sector and in the second aperture sector and that swings the first aperture sector and the second aperture sector. The first aperture sector and the second aperture sector are located in receding positions from the lens opening, when the drive pin is in an initial position. The cam openings include a swing region and a non-swing region, the swing region guiding a corresponding sector to the lens opening as the drive pin moves from the initial position, the non-swing region retaining the other sector in the receding position, when one of the first aperture sector and the second aperture sector is guided to the lens opening.

Abstract: A step motor includes a rotor having four magnetic poles, a first magnetic pole magnetically excited by a first coil, a second magnetic pole magnetically excited by a second coil, and a third magnetic pole magnetically excited by the first coil and the second coil. A gap between the third magnetic pole and the rotor is smaller than that between the first magnetic pole and the rotor and that between the second magnetic pole and the rotor. In the step motor, it is possible to intensify the influence, on the rotor having four poles, of the magnetic fields created from three magnetic poles. Accordingly, this can weaken the magnetic fields set up from the first magnetic pole and the second magnetic pole, which tend to intensify the influence on the rotor, enabling the torque smaller at the time of the rotation start of the rotor.

Abstract: A step motor includes a rotor having four magnetic poles, a first magnetic pole magnetically excited by a first coil, a second magnetic pole magnetically excited by a second coil, and a third magnetic pole magnetically excited by the first coil and the second coil. A gap D between the third magnetic pole and the rotor is larger than a gap d between the first magnetic pole and the rotor and the gap d between the second magnetic pole and the rotor, so that a magnetic attraction is generated between a pole of the rotor and the first magnetic pole and between another pole of the rotor and the second magnetic pole. With this step motor applied to a shutter driving mechanism of a camera, it is possible to surely retain the shutter state even when the current does not flow.

Abstract: A sector drive mechanism includes an electromagnetic actuator including a rotor having four polarities, a C-shaped stator, and a current control portion that controls current applied to a first coil and a second coil, the C-shaped stator including a first magnetic pole magnetically excited by the first coil, a second magnetic pole magnetically excited by the second coil, and a third magnetic pole magnetically excited by the first coil and the second coil, and sectors that are connected to the electromagnetic actuator to open and close a shutter opening provided in a substrate. The first coil and the second coil are driven to close the shutter opening with a fewer number of pulses applied from the current control portion than the number of the pulses to open the shutter opening.

Abstract: A step motor includes a rotor having four magnetic poles, a first magnetic pole magnetically excited by a first coil, a second magnetic pole magnetically excited by a second coil, and a third magnetic pole magnetically excited by the first coil and the second coil. A gap between the third magnetic pole and the rotor is smaller than that between the first magnetic pole and the rotor and that between the second magnetic pole and the rotor. In the step motor, it is possible to intensify the influence, on the rotor having four poles, of the magnetic fields created from three magnetic poles. Accordingly, this can weaken the magnetic fields set up from the first magnetic pole and the second magnetic pole, which tend to intensify the influence on the rotor, enabling the torque smaller at the time of the rotation start of the rotor.

Abstract: A shutter for a camera capable of opening a shutter sector in a reduced period of time includes a shutter opening formed in a shutter plate, shutter sectors for opening and closing the shutter opening, a drive lever having a drive pin for operating the shutter sectors, and an actuator for driving the drive lever. The drive pin penetrates through-holes formed in the shutter sectors. The through-holes have a size sufficiently large so that the drive lever is driven by the actuator substantially in a no-load state immediately after starting to drive the drive lever so that the shutter sectors are not moved until the drive pin has achieved sufficient acceleration.

Abstract: A camera shutter has a base plate provided with a shutter opening. Sectors are mounted on the base plate to undergo movement to open and close the shutter opening. A driving lever has a driving pin that extends through through-holes in the sectors for operating the sectors. One of the through-holes is configured so that a gap is formed between an edge of the through-hole and the driving pin in the direction of movement of the driving pin. As the driving pin moves to drive the sectors to close the shutter opening, the movement of the driving pin is abruptly stopped when the sectors fully close the shutter opening thereby causing the driving pin to rebound. The rebounding motion is not transmitted to the sector in which the gap is formed, and inertia permits further movement of the sector in the closing direction over a distance equal to the gap. This maintains the sectors in overlapping relation and prevents reexposure when the shutter is in a fully closed state.

Abstract: A camera shutter has a base plate provided with a shutter opening. Sectors are mounted on the base plate to undergo movement to open and close the shutter opening. A driving lever has a driving pin that extends through through-holes in the sectors for operating the sectors. One of the through-holes is configured so that a gap is formed between an edge of the through-hole and the driving pin in the direction of movement of the driving pin. As the driving pin moves to drive the sectors to close the shutter opening, the movement of the driving pin is abruptly stopped when the sectors fully close the shutter opening thereby causing the driving pin to rebound. The rebounding motion is not transmitted to the sector in which the gap is formed, and inertia permits further movement of the sector in the closing direction over a distance equal to the gap. This maintains the sectors in overlapping relation and prevents reexposure when the shutter is in a fully closed state.

Abstract: A shutter for a camera comprises sectors for opening and closing a shutter opening by reciprocal pivotal movement, a motor for reciprocally and pivotally moving the sectors by forwardly and reversely rotating a rotor of the motor by forward and reverse electricity conduction to a coil, a memory circuit having stored therein electricity conduction data of the coil corresponding to operational characteristics of the motor and the sectors, and a control circuit for controlling electricity conduction to the coil in accordance with a brightness of an object to be photographed and executing exposure control in accordance with the brightness of the object. The electricity conduction data includes reverse pulses for rotating the rotor in a direction reverse to a direction of opening the sectors for reducing acceleration of the sectors during opening movement thereof, and forward pulses for rotating the rotor in the direction of opening the sectors for continuing the opening movement of the sectors.

Abstract: A shutter for a camera capable of opening a shutter sector in a reduced period of time includes a shutter opening formed in a shutter plate, shutter sectors for opening and closing the shutter opening, a drive lever having a drive pin for operating the shutter sectors, and an actuator for driving the drive lever. The drive pin penetrates through-holes formed in the shutter sectors. The through-holes have a size sufficiently large so that the drive lever is driven by the actuator substantially in a no-load state immediately after starting to drive the drive lever so that the shutter sectors are not moved until the drive pin has achieved sufficient acceleration.