Abstract: An operation mode display device is provided for a picture taking device such as a camera which controls exposure in a plurality of modes such as a programmed automatic exposure control mode, a diaphragm priority automatic shutter speed control mode, a shutter speed priority automatic diaphragm control mode and a manual exposure control mode. A plurality of display devices are individually operable for displaying a letter for each display means and arranged in a single line to display the letters P, R, O, G, R, A, M and S in order of mention. When the programmed automatic control mode, which is the most frequently used mode in practice, has been selected, all or almost all of the display devices are driven to display the letters "PROGRAMS" or "PROGRAM". When another mode, e.g., the diaphragm priority automatic shutter speed control mode has been selected, one of the display devices is driven to display a single letter "A".

Abstract: A camera includes a manually adjustable photographic parameter such as diaphragm aperture, shutter speed, focus distance or the like and an electrically energizable network indicating the value of the adjusted parameter or a related value. The indicator network is connected through a normally open signal controlled semiconductor switch to a current source and a device is located on the manually accessible face of the photographic parameter adjusting member and is electrically connected to the switch network input and is touch responsive to produce of switch network closing signal so as to automatically energize the indicator network upon manual engagement of the adjusting member. The sensing member is alternatively a pair of spaced conductor electrodes or a piezo-electric element and the switch is respectively responsive to resistance or voltage values applied to its input. A network is provided for opening the closed switch after a predetermined period.

Abstract: An automatic diaphragm control device is constructed such that energization of a release electromagnetic causes a release interlock mechanism to simultaneously release diaphragm stop means and a diaphragm operating mechanism. This allows the diaphragm stop means to stop the diaphragm operating mechanism at a position maintaining the diaphragm fully open when a diaphragm control circuit, based on T.T.L light measurement, generates a diaphragm stop signal simultaneously with the energization of the release electromagnet to energize a diaphragm determination electromagnet which in turn releases the diaphragm stop means. In response to termination of an exposure, a reset member directly engages and returns the release interlock mechanism and the diaphragm operating mechanism while returning the diaphragm stop means through the release interlock mechanism.

Abstract: In an exposure control system for a camera having an interchangeable objective lens, a diaphragm mechanism defining the diaphragm aperture, a preset means for presetting the f-number of the diaphragm aperture and a shutter mechanism for effecting an exposure, a light measuring circuit generates an output signal having a level representative of the light from an object to be photographed and a reference signal circuit generates a reference signal having a predetermined level. A programmed signal circuit generates a programmed signal in accordance with the output signal and the reference signal, and an exposure control circuit controls both the diaphragm and the shutter mechanisms such that the diaphragm aperture and the shutter speed have a combination of values commensurate with the programmed signal. The programmed signal circuit includes a variable member having an electric parameter variable in accordance with the number of steps of the diaphragm aperture from the minimum f-number to a preset f-number.

Abstract: A camera diaphragm control device which arrests a diaphragm when a TTL light measurement output represents a given relationship with respect to a reference signal during stop down operation of the diaphragm can automatically set the diaphragm to a specific aperture for flash photography by the aid of a preliminary flash light produced prior to the production of a primary flash light with its intensity maintained substantially constant for a duration covering the period of time from the automatic setting of the diaphragm to the setting of the specific aperture.

Abstract: A camera body particularly suited for a lens exchangeable single lens reflex camera is composed of a plastic body proper having a metal block insert, and including a pair of side housings for a film patrone chamber, a spool and sprocket chamber, a bottom wall and a pair of interconnecting portions extending between the housings. The metal block includes a flat rear plate portion having an exposure aperture, film pressure plate abutting surfaces and film guide rails, a pair of bent portions projecting forwardly from the opposite sides of the flat plate portion to constitute a part of the walls of the side housings, and a pair of front metal plate attaching portions formed at the front ends of the bent portions. The rear plate portion and the bent portions of the metal block are anchored or held by a pair of anchor portions of the plastic body proper, which continuously extend along the upper and lower opposite faces of the flat plate portion and the bent portions, respectively.

Abstract: An exposure control system for a photographic camera of a type having a two-curtain type focal plane shutter. When used in combination with an electronic flash device in which the voltage stored on a capacitor is discharged through a flash tube to illuminate the target object to be photographed, this system is switched from an automatic or manual daylight exposure mode to an automatic flash exposure mode when the voltage stored on the capacitor in the flash device reaches a predetermined amount. The shutter is closed in response to the firing of the flash device.

Abstract: A lens exchangeable camera has two automatic exposure control modes, one of which is a program exposure control mode and the other of which is an aperture priority automatic shutter speed control mode. The program exposure control mode is selected when a diaphragm presetting ring on an exchangeable lens mounted on the camera is set to a position to preset a minimum aperture size or maximum f-number. The aperture priority automatic shutter speed control mode is selected when the diaphragm presetting ring is set to a position to preset an aperture size other than the minimum aperture.

Abstract: A camera exposure control device having TTL light measuring circuitry capable of spot metering and also averaged metering is disclosed, the spot metering being used for measurement with the camera directed to a main object prior to the camera release operation, and the averaged metering being used for measurement with the camera positioned for making a desired composition including the main object. The difference between the logarithm of the spot metering output and that of the averaged metering output with the aperture at its initial size is stored prior to the aperture stopping-down motion.

Abstract: A hollow pentagonal roof type reflecting mirror assembly for use in a viewfinder optical system of a single lens reflex camera is dust tight to prevent entry of dust into the inside hollow space and includes a filtered vent aperture to allow passage of vapor so that condensation will not occur inside the assembly. The assembly includes a hollow pentagonal body having roof and front mirrors and at least one vent aperture and a shielding or sealing member arranged to close the vent hole. The shielding or sealing member is made of a dust proof and ventilative material such as a foamed plastic, a paper and a cloth to filter out any dust particles.

Abstract: In a lens barrel for automatic and manual focus control of a camera, a non-movable barrel is adapted to be mounted on the camera and a first movable barrel is movably carried by the non-movable barrel with a second movable barrel movably carried by the first movable barrel and a third movable barrel movably carried by the second movable barrel for carrying at least one lens group for focussing by means of axial movement of the lens group. The third movable barrel is guided for movement without rotation relative to the non-movable barrel and the second movable barrel is shifted along the optical axis of the lens group relative to the non-movable barrel. The third movable barrel is shifted along the optical axis relative to the non-movable barrel with either the shifting of the second movable barrel or the shifting of the third movable barrel being for automatic focus control operation and the other being for manual focus control operation.

Abstract: A dioptry adjusting mechanism for an eyepiece of a viewfinder for a single lens reflex camera in which the eyepiece includes a negative lens element movable along the optical axis of the view finder for the dioptry adjustment and a stationary positive lens element located at the eye side of the negative lens element, the mechanism including a lever rotatable in response to a manual operation to displace the negative lens element translationally, with a guide member guiding the lens. A manual member for the adjustment may be disposed somewhat remote from the lenses.

Abstract: A mounting structure for levers and the like such as in a reflex camera mirror box includes a metal base plate which may be the wall of the box and one or more tongues stamped from and bent outwardly perpendicular to the base plate and a synthetic organic polymeric resin having low friction and low light reflectivity properties molded to integrally form a layer on the base plate inside face, portions to fill the openings in the plate left by the tongues and externally cylindrical sheaths at least partially enveloping the tongues and functioning as reinforcing cores and defining projections which serve as pivots for swingably supporting levers, as lever stop abutments or for other functions. Where a projection is exposed to little stress, the core tongue may be omitted and by providing recesses in a tongue circumferential surface, the connection of the sheath to the plate covering resin layer may be omitted.

Abstract: A camera focal plane shutter including longitudinally movable leading and trailing curtains is provided along the transverse border of one of the curtains with a transverse shield element projecting into and terminating along a line disposed in the path of the other curtain and functions to shield the objective lens traversing light obliquely incident in the area of the curtain overlapping portions. The shield element may be a transversely curved strip or loop integrally formed with or clamped to the respective curtain border by an edge defining channel member, or may be an extension of a respective channel member arm or may be a light weight bar bonded to the curtain member proximate its channel member clamped border.

Abstract: An automatic exposure camera, for example a TTL light measuring camera including a light measuring circuit, an exposed condition indicating circuit, and a light information storage circuit includes a normally open semiconductor switch connecting the circuits to a source of energizing current and actuated to a closed condition in response to a conductor being coupled across its control input terminals, at least one of which is defined by the camera manually operated shutter release members. In one form the switch input terminals are connected to mutually insulated coaxial members forming the release button and exposed at their top and in another form such terminals are connected respectively to the camera body and an electrically insulated top exposed portion of the release member. Thus, merely touching the release button by the photographer energizes and activates the respective circuits.

Abstract: A pentagonal roof reflecting mirror assembly for use in a viewfinder optical system of a single lens reflex camera is provided. The roof mirror assembly is of a modular form and includes an upper roof member and a lower roof support member that can be fastened together to form an enclosure that prevents the entrance of dust. The upper roof portion includes at least a pair of roof walls provided with a first and second mirror. The lower roof support member includes at least a lower light transmission wall and a side front wall provided with a third mirror positioned opposite to the first and second mirrors. The lower roof support member is molded of a transparent plastic material to permit light flux for the viewfinder optical system to enter the enclosure through the lower light transmission wall. Optical elements such as prisms, fresnel lens, plano-convex and plano-concave lenses can be molded as an integral part of the support assembly.

Abstract: A plate member bearing thereon a pair of first symbols respectively representative of the highest shutter speed and the lowest shutter speed, a pair of second symbols respectively representative of middle shutter speeds, and three letters or zone marks are arranged between the first and the second symbols and also between the second symbols. The plate member is disposed between a focussing plate and a pentagonal prism, which form a viewfinder of a single lens reflex camera. The first and second symbols are illuminated by light from outside of the camera, which light has passed through the focussing plate after being reflected by a movable mirror.

Abstract: In a still or motion picture camera including an electric circuit such as a light measuring circuit, an exposure control circuit, a sound recording circuit, or a capstan driving circuit, the shutter release button is provided with a piezo-electric element for developing an electric charge or potential difference when an external pressure is applied thereon. The pressure responsive piezo-electric element is connected in the electric circuit in response to the pressure applied on the pressure responsive element, whereby the electric circuit is enabled prior to the commencement of the exposure.

Abstract: A camera body includes at its rearside a frame having a rectangular window delineating the area of an image of an object projected onto the film and a pair of film guide longitudinal rails and is integrally formed of a reinforced polymeric resin or plastic material to reduce the weight thereof. Spacer members on which is abuttable a film pressure plate secured to the rear cover of the camera is made of metal of high machinability and are embedded in, clinched to, or threaded into the camera body so as to rearwardly project from the camera body. When abutting the spacer members, the pressure plate accurately positions a film guided by the film guide rails, in the direction perpendicular to a surface of the film, i.e., in the direction of the optical axis of a picture taking optical system since high accuracy is obtained by machining the spacer members.

Abstract: A camera body, particularly useful for a camera of the interchangeable lens type, includes a front metal unit having a mount member to which an interchangeable lens is attachable, a rear metal unit having an exposure framing aperture, film rail surfaces, an abutting surface on which a film pressure plate is abuttable and a mount surface to which the front metal unit is attached, and a body proper molded of a reinforced plastic with the rear metal unit imbedded therein and having a pair of box shaped main portions which are disposed at opposite sides of the rear metal unit and a pair of laterally extending portions which interconnect the main portions. The rear metal unit is provided with perforations formed as casting holes and packed and filled with the plastic and is of box shape with the front wall being open and the four peripheral walls being continuous with each other.