Abstract: In making reflection mirrors for optics, a technique is provided for making up a reflection mirror not of a glass-system material but of metallic material, and a method for high-precision mirror-machining of a metal plate is also disclosed.

Abstract: A winding device is provided with a first guide roller for bringing the tongue of the film into contact with a frictional member on the outer periphery of a takeup spool, and a second guide roller for conforming the film tongue to the takeup spool when the film is wound on the takeup spool by almost one turn, wherein the free end portion of a support plate for the second guide roller is extended concentrically to the pivot shaft of the support plate.

Abstract: A mirror box formed of metal serves as a metallic portion constituting together with a plastic portion an essential part for imparting strength characteristics to a camera body. The metallic portion is provided with a base for a lens mount and with similar parts for assembling other element. During molding, some of the metallic segments of the lens mount base are inserted as a framework into the plastic portion so that the metallic and plastic portions are constructed in the form of a unit. This unit is then assembled with other portions as the base unit of the essential part to complete a single lens reflex camera body.

Abstract: In the disclosed camera, a switchover arrangement automatically shifts from an automatic exposure mode to a flash mode in response to a charge completion signal from a flash device. A line electrically connects a terminal capable of receiving the charge completion signal from the flash unit to the switchover arrangement. A switch connected to the connecting line applies a signal of a value corresponding to the charge completion signal from a signal source in the camera to the switchover arrangement to cause the latter to effect a switchover to the flash mode in response thereto in the same manner as when a charge completion signal is applied thereto.

Abstract: An electromagnetically driven shutter, wherein between the electromagnetic driving source and the shutter blade actuating member which receives the driving force from the driving source a play is provided in such a manner that after the electromagnetic driving source has run a certain determined distance the driving force is transmitted to the shutter blade actuating member so as to let the shutter blade start to run.

Abstract: A process for producing an electromagnetically driven focal plane shutter including the steps of assembling an electromagnetic drive source and transmission members in a drive unit and the shutter blade groups in a shutter blade unit, and then assembling these units in a final unit.

Abstract: A camera having an electromagnetic driving source for operating a focal plane shutter in the camera, includes a shutter base plate and a driving arm pivoted on the base plate for swinging movement in a plane parallel to the plate. A group of thin shutter blades are supported on the driving arm parallel to the surface of the base plate. The output shaft of a motor is coupled with the driving arm, and either one of the rotor of the motor, or a permanent magnet forming a part of the stator of the motor, provides magnetic flux parallel to the axis of the output shaft, thereby causing the rotor to rotate the output shaft and drive the focal plane shutter.

Abstract: An electromagnetically driven shutter of which the leading and trailing curtains are driven by respective electromagnetic drive sources to make a forward and backward movement. The electromagnetic drive sources each have a magnetic winding constructed in a unified form of two coils arranged to be supplied with respective currents flowing in direction opposite to each other so that the forward movement of each of the leading and trailing curtains is followed, after a controlled time interval, by the backward movement thereof.

Abstract: In a slit exposure shutter having leading and trailing blades driven to run down to make an exposure and to return to their initial positions by an electromagnetic drive source, this source is provided with electromagnetically operated latch means for holding the leading and trailing blades in either one of the terminal ends of running down and returning movement thereof. Another feature is that the above-described latch means is constructed by utilizing the magnetic attraction force of at least one of the stationary and movable electromagnetic members of the drive source.

Abstract: In the shutter disclosed, a conductor and a permanent magnet, movable relative to each other, form a driver to drive at least one shutter blade across an optical path for photographic light and the force of the driver is supplemented by an auxiliary spring arrangement that exerts zero force at the start of movement of the shutter blade and gradually increases toward termination of movement of the blade.

Abstract: Disclosed is a single lens reflex camera having an electrically driven focal plane shutter. A locking arrangement locks the shutter curtains in their start positions before shutter release to prevent unintentional actuation of an exposure due to faulty operation of switches, shock, or the like. Upon completion of the upward movement of the quick return mirror, the locking mechanism is disabled.

Abstract: An electromagnetic device for driving a shutter includes a moving coil which is arranged to rotate in the magnetic field of a stator. A current supply arrangement for supplying exciting current to the moving coil includes a pair of insulated side pieces fixed about the rotational axis of the coil and connected to both terminals of the moving coil, and a pair of elastic rod-shaped brushes pressed against the side pieces on diametrically opposite sides of the rotational axis. A slide surface on each slide piece is provided with at a pair of flatened portions against which the elastic rod-shaped brushes are pressed so as to hold the shutter blades at a stop position.

Abstract: In a camera provided with an electromagnetic drive source when energized producing an electromagnetic force by which the shutter is driven to move, the above-described electromagnetic force of drive source is used only as the power of driving the shutter, while an electromagnetic device which is controlled by a shutter closing signal is provided, so that an initiation of returning movement of the mirror and automatic diaphragm and of lock releasing operation of the film transporting mechanism is controlled by said electromagnetic device.

Abstract: A focal plane shutter mechanism for a single lens reflex camera has its shutter blades driven by an electromagnetic driving source, with setting of shutter blades to their running start positions being mechanically effected in association with mirror driving means thereby diminishing power consumption, and with the shutter blades being electromagnetically driven only during a film exposure.

Abstract: A slit exposure shutter having the front and rear screens thereof respectively arranged to be driven by a source of an electromagnetic driving force is provided with a minimum slit width insuring means which prevents uneven exposure resulting from difference in travelling speed between the front and rear shutter screens during a high speed shutter operation and particularly prevents a total absence of the slit, the shutter is also provided with a nullifying means which nullifies the insuring means when the shutter screens are on their return travels.

Abstract: An automatic exposure control device for a camera capable of permitting flash photography includes an exposure computing portion for natural light photography wherein the computing portion generates an exposure signal corresponding to the brightness of an object and an exposure computing portion for flash photography wherein the computing portion is arranged to generate an exposure signal suitable for a flash photographing operation. An exposure control portion is responsive to one of the exposure signals generated by the natural light photographing exposure computing portion and the flash photographing exposure computing portion. A change-over device applies one of the exposure signals to the exposure control portion. An electromagnetic release device actuates the internal mechanism of the camera wherein the release device produces an electrical signal when it operates.

Abstract: A digital system for controlling coordination of the various portions of the camera to operate in selected modes including the automatic and bulb modes is provided with signal forming means comprising a count start switch and a bulb control switch connected in parallel to each other. Where the automatic mode is selected, in a predetermined time interval after the initiation of an actuation of release of the camera, as the both switches are open, the signal forming means produces an actuating signal which is then applied to discriminating means, causing the shutter to operate automatically. Where the bulb mode is selected, no actuating signal is produced even after the termination of duration of the predetermined time interval so that the discriminating means permits the opening of the shutter to continue until the termination of the release actuation.

Abstract: An exposure control device for a camera having a first counter which performs analog-to-digital conversion for a photometric purpose and a second counter for sequence control of each part of the camera. For use of a self-timer, the first and second counters are connected in series with each other to use them in a state of having their steps added together. Upon completion of a self-timer photographing operation, the first and second counters are separated from each other and are brought back into their original conditions.

Abstract: A slit exposure shutter which has an electromagnetic drive source and is arranged to have shutter blades moved by rotation of a rotor not exceeding a half turn to perform exposure effecting and returning travels. The weight of the shutter blades and that of the rotor are arranged to be approximately in balance by having the rotation shaft of the rotor eccentrically disposed in a position deviating from the center of the rotor.

Abstract: A device for preventing erroneous operation of a camera is disclosed. The device includes an electromagnet for closing the camera shutter. Current supply apparatus supplies current to the electromagnet. A detection device is employed for detecting whether current from the current supply device has been supplied to the electromagnet. The detection device produces a detection signal when the current is supplied to the electromagnet. A signal generation device has a switch which closes in response to the release operation wherein the signal generation device generates an electrical signal when it receives the detection signal from the detection device. A control device is included for generating a check signal and a release signal. The control device produces the check signal for a predetermined period of time only when it receives the electrical signal from the signal generation device to actuate the detection device.