Abstract: An electromagnetic device is provided with a coil bobbin (1) supporting an excitation coil (5) and a U-shaped movable iron piece (2) whose one side (2a) is inserted in and fixed to a hollow section (1a) of the coil bobbin (1) in a state where it is held between a pair of iron cores (3) and (4). A remaining side (2b) of the U-shaped movable iron piece (2) is inserted in a through-hole section (1c) of the coil bobbin (1) and has a resilient characteristic that it is spaced away from the one side (2a). The top surface of each of rising sections (3a) and (3b) of the iron cores (3) and (4) is configured by bending the end of each of the rising sections (3a) and (3b) and is located to be opposite to the top of the remaining side (2b) at a preset distance away.

Abstract: An electromagnetic device is provided with a coil bobbin (1) supporting an excitation coil (5) and a U-shaped movable iron piece (2) whose one side (2a) is inserted in and fixed to a hollow section (1a) of the coil bobbin (1) in a state where it is held between a pair of iron cores (3) and (4). A remaining side (2b) of the U-shaped movable iron piece (2) is inserted in a through-hole section (1c) of the coil bobbin (1) and has a resilient characteristic that it is spaced away from the one side (2a). The top surface of each of rising sections (3a) and (3b) of the iron cores (3) and (4) is configured by bending the end of each of the rising sections (3a) and (3b) and is located to be opposite to the top of the remaining side (2b) at a preset distance away.

Abstract: In a camera battery charger, a solar battery is provided upon a lid of a camera case, and a charging circuit for charging the in-camera battery by the solar battery or an external battery. When a camera is stored in a main body of the case, the in-camera battery is electrically connected to a power supply output terminal of the charging circuit, and is normally charged by the solar battery. When high-speed charging is necessary, the in-camera battery is charged at high speed by an external battery in an external battery adapter set in the main body of the case, or an external battery stored in an external battery storage part integrated with the main body of the case.

Abstract: An overhead projector has a stage on which original material is placed. The stage has a Fresnel mirror. An electrostatic attracting structure is integral with the Fresnel mirror. The attracting structure includes a conductive membrane of ceramic and a resinous dielectric/protective layer. The conductive membrane consists of a pair of comb-shaped electrodes, which interfinger in coplanar fashion, and are covered by the dielectric/protective layer for insulation and protection. A power supply device applies a high voltage of direct current to the electrodes. The original material is attracted electrostatically by the electrodes, and can be kept flat on the stage. In a preferred embodiment, the power supply device incorporates a self-starting blocking oscillator, which is adapted to boost the voltage sufficiently for electrostatic attraction.

Abstract: An optical apparatus having a base table on which an original is placed and an image forming unit with an optical system which projects an image of the original onto a remote screen for showing the same to a number of viewers. A foldable structure is provided, having a support structure mounted on a base table for movement between a lowered position covering the base table and a raised position wherein the image forming unit is located above the base table so as to form and project the image of the original onto the remote screen. A linkage interconnects the image forming unit and the support structure for causing a movement of the image forming unit relative to the support structure upon movement of the support structure between the folded and unfolded positions, thereby placing the image forming unit above the base table when the supporting means is in the raised position and flush with the support means so as to cover the base table when the support means is in the lowered position.

Abstract: An electonic copying machine for making a hard copy of a remote original comprises a housing and an image pick-up unit pivotally mounted on the housing for vertical swinging movement between a raised use position and a lowered non-use position. In the housing, there are a scanner for scanning the remote original with a line of light projected through a transparent window plate, a recording head and image recording paper. In the image pick-up unit, there are a lens for forming a line image of the scanned remote original on the recording paper, a line image sensor for reading the line image formed thereon by the lens to provide line image signals according to which the image recording head records and image on the recording paper, shifting the line image sensor by a predetermined pitch in a direction perpendicular to the longitudinal direction of the line image sensor.

Abstract: A copying machine for making a hard copy of an original comprises an image sensor for reading an image of the original to provide image signals, a memory for memorizing the image signals after or before processing the image signals for necessary corrections, and a printer for printing an image on a copying sheet according to the image signal after image processing. Preferably, a thermal printing head and a heat sensitive sheet are used. The copying machine is compact and either is incorporated in a portable overhead projector or is used as a writing board copy machine. In the former case, the image sensor is disposed in a supporting arm for supporting an image projection lens assembly above a base section of the overhead projector on which a transparent original is placed.

Abstract: An electric shutter device wherein an armature lever is attracted by an electromagnet by making a large current flow to the electromagnet only when the operation of a self-timer ends so that a normal exposure operation may be thereby started in order to minimize the power consumption during the operation of the electric self-timer. This electric shutter device is provided with a pair of shutter blades which are also diaphragm blades, a closing drive plate engageable with the armature lever to control the opening and closing of the shutter, an exposure time controlling circuit controlling the energizing time of the electromagnet to determine a proper exposure time, an exposure warning circuit and a flash controlling circuit.

Abstract: A program type electric shutter wherein a shutter blade which is also a diaphragm blade and is made to be able to latch an exposure warning indicating device to be inoperative just before the beginning of the opening of the shutter blade and a diaphragm device which can open and close a window for a light receiving element are operatively connected with each other in order to prevent the mis-indication of the exposure warning indicating device. This electric shutter is provided with an electric self-timer device and a flash controlling circuit.

Abstract: An electric shutter means which comprises a voltage checking circuit connected to an exposure time control circuit including an electromagnet for controlling the time of closing shutter blades so that, when the voltage of a power source battery for said exposure time control circuit has dropped to be below a predetermined level, the passage of electricity to said electromagnet may be forcibly interrupted by said voltage checking circuit.BACKGROUND OF THE INVENTIONa. Field of the InventionThe present invention relates to electric shutter means, and more particularly to an electric circuit to be applied to an electric shutter arranged so that, when the power source voltage has dropped to be below a predetermined level, the exposure time may be mechanically controlled with a specific shutter speed.B. Description of the Prior ArtA camera equipped with an electric shutter is generally provided with a voltage checking means.