Abstract: An A/D converter having folding circuits for being supplied with analog signal pairs and reference voltage pairs and for outputting folded differential current pairs; first comparators for comparing the differential current pairs supplied from the folding circuits and for outputting higher 3 bits of a Gray code; sine wave generators for outputting 4-phase sine wave pairs; a current interpolation circuit for interpolating the 4-phase sine wave pairs and outputting 32 sine wave pairs; second comparators for comparing the sine wave pairs with each other respectively; and a Gray code encoder for encoding the outputs of the second comparators into lower 5 bits of the Gray code. Thus, the A/D converter can be made high in speed, lower in operating voltage, finer in density and higher in integration.

Abstract: A wire cut electric discharge machine according to the invention includes a machining tank storing a machining fluid, an upper arm disposed at an upper portion of the machining tank, a lower arm inserted into the machining tank, a wire electrode extending between the upper arm and the lower arm for performing electric discharge machining on a workpiece placed fixedly in the machining tank, a support member mounted to the machining tank for supporting the lower arm such that the lower arm is slidable relative to the machining tank and sealed from the machining tank, and an O-ring interposed between the lower arm and the support member. The support member has a groove formed all around its inner circumference, and the O-ring makes contact with sidewalls of the groove. Accordingly, even when the outside diameter of the O-ring varies depending on an error in diameter of the lower arm, contact between the sidewalls and the O-ring remains unchanged and fluid-tightness can be reliably ensured.

Abstract: A camera having a photographic optical system, a lens barrel disposed to be movable relative to a camera body in a direction of an optical axis and holding the photographic optical system, a focal length switchover mechanism for moving the photographic optical system such that the photographic optical system has a longer focal length as the same is moved forwardly in the direction of the optical axis, and a lens barrier displaceable between a closed position and an opened position for covering and uncovering a front face of the lens barrel. This lens barrier is disposed independently of the lens barrel adjacent a front end of the lens barrel having returned to a home position thereof at the side of the camera body such that the lens barrier is not movable in unison with the lens barrel.

Abstract: A camera having zoom lenses of a photographing optical system, zoom lenses of a viewfinder optical system, and a driving motor for driving both zoom lenses. A transmitting mechanism for transmitting the force of the driving motor to the zoom lenses of the viewfinder optical system having a gear train connected to the driving motor and a rotation cam which is provided coaxially with the last gear of the gear train to drive the zoom lenses of the viewfinder lens. A key projects from the end of the periphery of a rotation shaft included in the cam. The last gear is mounted around an end of the rotation shaft of the cam and has a key groove engaging the key. A play is provided between the key groove and the key.

Abstract: A camera having a photographic optical system capable of switching over a focal length having a control member, a cam operatively connected with the control member, a first cam face defined on the cam for effecting a focus adjustment in a first focal length, a second cam face defined on the cam for switching over from the first focal length to a second focal length, a third cam face defined on the cam for effecting a focus adjustment in the second focal length and a cam follower driven by the first through third cam faces and connected with the photographic optical system to drive the same. The second cam face is aligned in an operative direction of the cam or peripherally relative to the first cam face and the third cam face is aligned in the operative direction of the cam or peripherally relative to the second cam face.

Abstract: A contralight compensation exposure control system which determines as a contralight condition and fires a strobe when there is a difference between the output of a partial light measuring means for measuring the brightness of a portion of a scene to be photographed i.e. the brightness of the main object such as a person, and the output of an average light measuring means for measuring the brightness of comparatively large area of the scene i.e. the brightness of the subordinate object such as the background of the main object. The control circuit of the system inhibits the strobe firing and actuates an exposure compensation means to shift the controlled exposure to the overexposure side when a detecting means detect uncompletion of charging of the main capacitor for firing the strobe even if the contralight condition is detected.

Abstract: A film information reading system for automatically reading film information such as film sensitivity from code patterns on a film cartridge mounted in a cartridge chamber of a camera. The code patterns comprise a six code areas arranged axially of the film cartridge. The reading system comprises a first electric contact to contact at least one of the second to fourth code areas, a second electric contact to contact the fifth code area, and a third electric contact to contact the sixth code area. The second and third contacts are in a short-circulating relationship. A film information readout circuit is connected to the contacts for reading the film information from conductive, and non-conductive states between the first to third contacts provided by the code patterns.

Abstract: A thin vertically disposed camera adapted for use with a disk type film contained cartridge includes latch device for catching a compartment door at its closed position and rotatably supported connecting member to be connected to a cover member of the cartridge loaded in the camera for moving the cover member between an exposure window opening position and an exposure window closing position. The latch device includes a manually operable portion movable between a locking position for enabling the latch device to catch the compartment door and a releasing position for disabling the latch device. The rotation of the manually operable member from its releasing to locking position is same in the direction as the rotation of the connecting member for moving the cover member from its exposure window closing position to the exposure window opening position. A motion transmitting mechanism is provided in the camera for transmitting the rotation of said manually operable member to the connecting member.

Abstract: A dustproofing mechanism for a thin, disc film cartridge type camera having windows in its front wall for the camera viewfinder and objective lens includes a cover structure guided for movement to alternative positions opening or closing both windows and an operating member accessible through one of the windows is connected to the cover structure to permit the manual selective movement of the cover structure to the window open or closed position.

Abstract: PCT No. PCT/JP78/00051 Sec. 371 Date Aug. 10, 1979 Sec. 102(e) Date Aug. 10, 1979 PCT Filed Dec. 12, 1978 PCT Pub. No. WO79/00384 PCT Pub. Date Jun. 28, 1979In a camera having incorporated therein two kinds of photographic lenses respectively selectively settable to a photographic position and a retired position thereof, the camera including an integrally molded camera body which is formed with a film position-determining surface and two lens position-determining surfaces with which respective ends of two kinds of photographic lenses are in contact at different positions with respect to the direction of the camera optical axis, and a space being formed between the two lens position-determining planes for accommodating one of the photographic lenses.Further, the photographic lenses are urged by springs against the respective position-determining planes at their photographic positions.

Abstract: A camera having at least two objective lenses of different focal lengths, which can be selectively externally manually positioned in the camera photographic optical path includes an inverted Galilean viewfinder optical system consisting of a front negative, divergent lens group and a rear positive, convergent lens group. The divergent lens group consists of two concave lenses which are transferrable between a first position providing a low magnification and a second position providing a high magnification. In the first position both concave lenses are in the viewfinder optical path and the other concave lens remains in the viewfinder optical path and is shifted to a second position axially spaced from its first position along the finder optical axis.

Abstract: A camera which incorporates a supplemental lens that may be selectively used in combination with a normal picture-taking lens by moving a selector device projecting externally of the camera. Movement of the selector device results in the supplemental lens being moved either into or out of the optical path of the picture-taking lens. An objective lens which is positioned in the optical path of the view finder system is operable so as to be movable with respect to the view finder optical path upon movement of the supplemental lens to automatically compensate for parallax when the supplemental lens is positioned in the optical path of the picture-taking lens for modified photography.

Abstract: Compositions comprising a polycarbonate resin and a mixture of anthraquinone series colorants have excellent transparency.