Abstract: To solve an uneven light quantity caused in a case where a light guide plate, in which light from a spot light source such as an LED enters an surface, changes by 90 degrees and exits the light to the outside, is used as a backlight. The light guide plate of the invention includes a light flux unifying region. The light flux unifying region has an incident surface, a first surface, and an exit surface. Light fluxes emitted from a light source enter the incident surface. The first surface is almost perpendicular to the incident surface and the intensity distribution of the light fluxes having entered is unified at the first surface. The exit surface is disposed almost parallel with the incident surface and the unified light fluxes exit from the exit surface. A boundary line between the incident surface and the first surface has a zigzag surface.

Abstract: To solve an uneven light quantity caused in a case where a light guide plate, in which light from a spot light source such as an LED enters an surface, changes by 90 degrees and exits the light to the outside, is used as a backlight. The light guide plate of the invention includes a light flux unifying region. The light flux unifying region has an incident surface, a first surface, and an exit surface. Light fluxes emitted from a light source enter the incident surface. The first surface is almost perpendicular to the incident surface and the intensity distribution of the light fluxes having entered is unified at the first surface. The exit surface is disposed almost parallel with the incident surface and the unified light fluxes exit from the exit surface. A boundary line between the incident surface and the first surface has a zigzag surface.

Abstract: A focal plane shutter for use in a photographic camera in which a shutter base plate is made of a synthetic resin material and a metallic supporting plate is mounted on a front surface of the shutter base plate. Shafts pivoting levers for driving a leading blade group and trailing blade group are fixed to a front surface of the metallic supporting plate, whereas shafts pivoting arms for driving the leading blade group and the trailing blade group are fixed to a rear surface of the supporting plate. The shafts pivoting the driving arms and supporting arms protrude from a rear surface of the shutter base plate.

Abstract: The forcal plane shutter for cameras is equipped with a first release lever capable of retaining a rear blade group at position to close an exposure aperture, and a second release lever capable of maintaining a front blade group and the rear blade group at the unfolded position thereof and the folded position thereof respectively until the front blade group and the rear blade group are attracted and retained at the unfolded position and the folded position respectively securely with an electromagnetic device. The focal plane shutter is of a double light interruption type which has excellent response to the release signal and capable of assuring stable operations. The focal plane shutter further comprises a control means capable of retaining the first release lever in the released state thereof and can be set in a successive photographing mode accordingly.

Abstract: In order to enable to obtain stable exposure time even for successive photographing at high speeds and completely synchronize flashing without errors, the focal plane shutter comprising a front blade group and a rear blade group is adapted in such a manner that the rear blade group is returned to its start position (folded position) substantially at the final stage of the shutter cocking travel, a retaining lever for locking the rear balde group at the unfolded position (position covering the exposure aperture) during the shutter cocking operation functions as a brake member for the rear blade operating lever, and said focal plane shutter is equipped with a movable X-contact lever which is retained at a position apart from a fixed contact by a front blade actuating arm during and after the shutter cocking operation and maintained at a position apart from the fixed contact by an X-contact release lever operated by the rear blade operating lever for the time from completion of the exposure operation to completi

Abstract: A light leakage preventing device for reflex cameras wherein a flexible light intercepting member is provided between the upper edge of a reflecting mirror and the vertical wall of a mirror box and a light intercepting member which can be brought to a light intercepting position in association with the movement of the reflecting mirror is provided between the lower edge of the reflecting mirror and the bottom wall of the mirror box so that, when the reflecting mirror is in a position in which it can conduct a light from an object to be photographed to a view finder, the light leakage from the upper edge and lower edge of the reflecting mirror to a film can be positively prevented.

Abstract: A bound preventing device for focal plane shutters which is provided with a rear blade operating arm which can move a rear blade between an exposure aperture covering position and opening position and a brake lever which is set in the motion track of the rear blade operating arm and can collide with a rear blade operating lever in order to control the rear blade operating arm in the final stage of the motion of the rear blade operating arm so as to prevent bounds when the motion of the rear blade ends. This brake lever can also catch the rear blade operating arm when it collides with the rear blade operating arm.

Abstract: A blade type focal plane shutter wherein an auxiliary arm is always biased with a spring so that backlashes at pivotably connecting points between a driving arm and shutter blades and between the auxiliary arm and shutter blades may not have a bad influence on the shutter opening and closing motions. This focal plane shutter is provided with a braking lever which can catch a closing driving lever to prevent a bound from being caused when the motion of the shutter blades for exposure ends.

Abstract: A cocking mechanism for electric focal plane shutters arranged so that, in order to simplify the cocking mechanism, while a shutter opening controlling armature lever is brought to the cocked position from the uncocked position, a shutter closing controlling armature lever may be brought to the cocked position from the uncocked position by the shutter opening controlling armature lever and, when the shutter opening controlling lever is locked in the cocked position, the shutter closing controlling armature lever may be held in the cocked position.

Abstract: An automatic diaphragm aperture controlling device which includes an exposure information pulse generation circuit to generate a pulse in a number corresponding to an aperture value to be controlled, the obtained pulses being based on exposure informations such as a scene brightness or the like. A counter circuit is provided for counting the output of the exposure information pulse generation circuit, together with an aperture value pulse generation circuit for generating pulses in a number corresponding to an aperture value of a diaphragm stopped down in association with a diaphragm drive, and diaphragm fixing means for fixing the diaphragm aperture which fixing means is actuated when an aperture value pulse number is coincident with an exposure information pulse number.

Abstract: An exposure controlling circuit for electric shutters comprising a timer circuit which can determine a proper exposure time in response to the brightness of an object to be photographed and another time circuit which can determine the specific shortest exposure time in order to regulate the exposure time to be determined by the brightness of the object to be photographed to be less than the shortest exposure time obtainable by the inherent performance of the shutter mechanism to be used, whereby when the states of the above mentioned two time circuit started to act simultaneously in relation to the shutter release operation are reversed to each other, the shutter is closed. The above mentioned specific shortest exposure time can be selected.

Abstract: The digital shutter control circuit comprises a reference clock pulse generating circuit, a binary counter circuit having a plurality of output stages each issuing, upon counting the pulses from the reference pulse generating circuit, output signals corresponding to the exposure time to be set in the shutter in terms of 2.sup.n where n is an integer and a selector circuit connected to the shutter closing means and selectively connectable to any of the output stages. The binary counter circuit is actuated simultaneously with the actuation of the shutter opening means for opening the shutter so that the shutter closing means is actuated when the output signal is issued from the output stage to which the selector circuit is connected thereby closing the shutter to provide the selected shutter speed.

Abstract: An electroflash controlling circuit wherein, in order to make the fully open time of a shutter and the flashing time of a flash accurately coincide with each other, a delaying circuit operated by an electric signal for starting a shutter blade opening motion or an electric signal for starting a shutter blade closing motion is provided so that a flashing circuit may be triggered after the lapse of a delay time made by the delaying circuit.

Abstract: A focal plane shutter comprising a pair of upper arms rotatably supported on a shutter base plate and arranged with a spacing between them, a pair of lower arms overlapped respectively on said pair of upper arms with a spacing, three main shutter blades respectively supported by said upper arms so as to have overlapped portions even when developed between the respective pairs of upper arms and lower arms, and two auxiliary shutter blades respectively supported by the lower arms so as to overlap on the above mentioned overlapped portions when developed between the respective pairs of the upper arms and lower arms, in order to make the entire shutter device or particularly the dimensions in the vertical direction smaller. Tail portions are formed respectively at the free ends of the main shutter in the middle and the auxiliary shutter blades.

Abstract: An exposure controlling circuit for electric shutters incorporating therein a voltage drop detecting circuit which will issue a signal for passing a current to a coil for closing a shutter when a current source voltage becomes lower than a predetermined voltage in order to prevent the shutter closing motion from being made unable to be made by the drop of the current source voltage after the shutter is opened. This controlling circuit further includes a driving circuit for making an indication within the field of vision of the view finder of a photographic camera when a signal is issued from the voltage drop detecting circuit.

Abstract: A built-in self-timer for cameras comprising a cocking member movable to the uncocked position and cocked position, a sector gear engageable with said cocking member and capable of being brought to the cocked position from the uncocked position by the cocking member, a checking member engageable with an interlocking member and capable of locking in the cocked position a delaying gear train meshed with the sector gear, and a locking member engaged with the checking member and engageable with the cocking member and interlocking member so that, even after the self-timer is set in the using state, if the cocking member is returned to the uncocked position, the delaying gear train may be automatically returned to the uncocked position and, at the same time, the checking member and locking member may be moved to a position of not engaging with the interlocking member.