Abstract: A single lens reflex camera of the TTL light measuring type and mounting interchangeable objective lenses of the fully open and stopped down aperture light measuring type includes a two coil differential meter. One of the meter coils is connected through a photocell to a battery and the other coil is connected between the battery grounded first terminal and the arm of a double throw switch. An adjustable first resistor is connected between the switch first contact which is grounded through a normally open second switch and an objective aperture varied second resistor is connected between the battery ungrounded terminal and the first switch second contact. The open aperture light measuring objective lens is provided with an actuating element which functions upon mounting of the lens to close the second switch to short circuit the second coil when the first switch first contact is closed, thereby disabling the light measuring circuit and providing an indication thereof.
Abstract: A conveyor belt for use in electrophotographic copying apparatus, which conveyor belt has a plurality of apertures therein and comprises electrically insulating material that can be electrostatically charged, the size and the distribution of the apertures being such that sheet material on which a copy is to be produced can adhere by electrostatic attraction to the belt when the belt is installed in the apparatus and such that the tendency of the belt to impair the copy is less than that for a belt without apertures.
Abstract: The described invention relates to a focal-plane shutter for a photographic camera. This shutter is a slide system having a plurality of parts which move in timed sequence during exposure. The parts include a plurality of sliders which are displaceable relative to one another.This invention provides a form of focal-plane shutter for a photographic camera wherein there are slide systems which function during exposure in timed succession with each system having a plurality of slides which are movable relative to one another. Each of the slide systems has a driven element which is rectilinearly guided by a single rotatably mounted part held in operational engagement with each individual slide system in such a manner that the slide participating in forming the focal-plane slit width engages its driving part at a point which is at the maximum possible radial distance from the axis of rotation.
Abstract: A magnetic brush developer wherein the bias voltage applied to the brush roll is altered, i.e., reduced, during the transit therepast of the photoconductor drum's seal, thereby reducing the number of magnetic carrier beads which are carried out of the developer on the surface and edges of the drum seal.
December 6, 1974
Date of Patent:
September 28, 1976
International Business Machines Corporation
Abstract: A magnetic brush development system for developing latent electrostatic images carried by a photoconductively coated substrate has a split housing comprising a movable section with a sump for storing a supply of developer, a stationary section including one or more development rolls which are fed with developer from the sump to carry out the development process, a latching mechanism for releasably securing the movable section of the housing to the stationary section, and a flow gate which is interlocked with the latching mechanism so that the flow gate is closed to interrupt the flow of developer from the sump whenever the latch is released.
Abstract: In light exposure apparatus wherein the face plate of a color picture tube is exposed to the light from a light source through a swinging illumination intensity correcting filter, a correction lens and a color selection electrode, the effective surface of the illumination intensity correcting filter comprises a plurality of regions having different light transmitting ability, and the effect of the optical characteristics at the interfaces between the regions is arranged and substantially eliminated by the swinging motion of the illumination intensity correcting filter.
Abstract: Rotary shutter blade mechanism includes at least a shutter blade which rotates always in one direction. The driving energy of the shutter blade is recovered by a driving spring in the course of deceleration of the blade. An auxiliary actuating means is adapted to supply one directional rotative force to the driving shaft of the blade. A rotary cam means is secured to the driving shaft and has at its periphery at least one pair of accelerating portions and decelerating portions. A reciprocating lever means is pivotally mounted in the body portion of the mechanism. The lever means has a portion engageable with the accelerating and decelerating portions. A main actuating means urges the lever means so that the engaging portions may contact the rotary cam means. The driving shaft is locked when the respective foremost ends of the accelerating portions are engaged with the engaging portion of the lever means.
Abstract: A collapsible camera apparatus of a type having at least two sections connected in pivotal relation to each other with a substantially planar surface associated with one section pivotal about a line orthogonal to a second substantially planar surface associated with the other section, further includes circuit board means angularly and permanently prefolded in interconnecting relation between the planar surfaces in a manner whereby the angular prefold remains substantially uneffected by pivotal motion between the sections. The circuit board is arranged to flex in a gradual manner over an extended length portion thereof thus accommodating pivotal motion between the camera sections without flexing the printed circuit board means about its angular prefold.
Abstract: An exposure time control circuit for an electric shutter of a camera includes a monolithic IC having input circuitry in the form of a transistorized differential amplifier having two input terminals. A time-constant circuit develops a timing signal proportional to the brightness of the object field and applies it to one input terminal and a reference voltage signal is applied to the other input terminal to control the exposure timing. In order to enable varying the reference voltage through a wide range so that the input terminals can also be used for introducing other exposure information variables, such as input signals representative of the F-value, film sensitivity, etc., a transistor is connected between the IC and the source of electric power.
Abstract: A warning light display device for an electric shutter of a camera having an exposure time control circuit for determining the exposure time of an electric shutter in dependence upon at least the brightness of an object being photographed. A warning display circuit is connected with the exposure time control circuit and has a control transistor that receives the output of the exposure time control circuit and controls the visual indication of three stages of the warning display circuit comprising light emitting diodes that indicate adequate and inadequate exposure conditions. A reference time generating circuit is provided in the warning display circuit for developing a signal representative of a predetermined time duration and a control transistor thereof controls energization of the three stages as a function of a comparison of the exposure time duration developed by the exposure time control circuit and the predetermined time duration developed by the reference time generating circuit.
Abstract: A protected photographic film structure includes a strip of photographic film comprised of a series of frames, an information carrier strip secured to the strip of photographic film and running alongside the strip of film and bearing information concerning the printing order and/or the customer giving the printing order, and a pair of flexible protective strips each secured to the information carrier strip along the length of the information carrier strip at a respective one of the two faces of the information carrier strip. Each protective strip extends in direction from the information carrier strip towards the strip of photographic film and overlies and thereby protects a respective one of the two faces of the strip of photographic film.
Abstract: An exposure control system for photographic apparatus utilizing motor driven shutter-diaphragm blades in conjunction with a blade sensor which is selectively positioned along the path of blade travel in accordance with an exposure value and which provides a control signal for reversing the blade drive to terminate the exposure interval. In the illustrated embodiment, the sensor is coupled to a comparison photometer and moved along the path of travel of the blades in accordance with photometer setting. Upon initiation of an exposure cycle, the blades are driven from a blocking position through progressively enlarging aperture values until the sensor is actuated by the blades. At this time the control circuitry is triggered to reverse the motor operation thereby returning the blades to a light blocking condition which terminates the exposure interval.
Abstract: A photographic exposure control system which automatically functions in an ambient mode of operation, in response to scene light values and in a flash mode of operation, in response to both scene light values and scene ranging, the latter providing select aperture values in accordance with anticipated flash illumination of the scene, includes a trim mechanism providing operator variation of the automatic settings for both the ambient and flash modes of operation. The trim arrangement provides a single control which alters both the photoresponse of the system and the selection of aperture with scene ranging so as to modify only the photoresponse for ambient operation and both the photoresponse and the scene ranging response for the flash illumination mode.
Abstract: An automatic exposure control circuit for a single lens reflex camera of the TTL light measuring type in which light entering through an eyepiece, in addition to light entering through an objective lens, is compensated for accurate exposures of the film. The automatic exposure control circuit of the invention is characterized in that, even if the characteristics of the circuit components for the two measured values of light are not exactly identical with each other, predetermined correct shutter control characteristics can be obtained through the provision of voltage control means for trigger levels, by which arrangement, marked improvement is achieved from the view point of mass production.
Abstract: An off-photometric-range indicating device for photometric circuits for cameras visually indicates to a photographer when the brightness of an object to be photographed is off the set photometric range of the photometric circuit. The indicating device includes a detection circuit to detect the brightness of the object and to produce an output signal when the detected value of the brightness is out of the photometric range of the photometric circuit, a switching circuit connected to the detection circuit and operated by said output signal, and a circuit connected to the switching circuit and actuated by the operation of the switching circuit to scale out the indicator, which may be visually observed by the photographer.
Abstract: An automatic exposure control circuit for a camera or the like includes a memory circuit comprising a series connection of a capacitor and an impedance element connected to an input of a high input impedance circuit to enable the measurement of the amount of mean light during photography under a fluorescent lamp.
October 29, 1974
Date of Patent:
August 10, 1976
Matsushita Electric Industrial Co., Ltd.
Abstract: The present invention relates to an exposure control apparatus for a camera which is so designed that the output terminal of the light measuring circuit of the brightness of the object to be photographed having a photo electric transducing means is connected to one input terminal of an operation amplifier. The output of the photographing information setting circuit, having a variable resistance means for setting other photographing informations than the information of the brightness of the object to be photographed, is connected to the other input terminal of the above mentioned operation amplifier. This is done in such a manner that proper exposure conditions can be obtained by means of the output of the exposure control circuit connected to the output of the above mentioned operation amplifier. Each input signal to the operational amplifier is adjusted by a bias signal which is controlled in accordance with ambient temperature conditions.
Abstract: Apparatus for electrophotographically imaging a photosensitive film in which a fractional area of the film, selected by automatic or preprogrammed access, is electrostatically charged and thereafter exposed to a pattern of radiation, is moved along a path of travel to a second location at which the latent image is developed by the application of toning fluid, and is preferably returned along the path of travel to fix or fuse the developed image as a next adjacent area is indexed for exposure. Additional areas of the film may be sequentially imaged by repeating the above sequence or by reinserting the partially completed film at a later time and addressing any desired used or unused area.
Abstract: An electromagnetic trigger device for use with camera capable of automatic time exposure, comprises: a power supply; a motor; a trigger switch; shutter driving means driven by said motor for driving a shutter and movable between a fully closed position and a fully open position, said shutter driving means fully opening the shutter when it is at the fully open position and fully closing the shutter when it is at the fully closing position; engaging means movable between a latching position and a non-latching position, said engaging means being adapted, when moved to said latching position, to latch said shutter driving means which occupies one of the fully open and closing positions; a motor switch which is closed for electrically connecting said motor to said power supply, when said engaging means is in said non-latching position; a starting coil for attracting said engaging means, when energized, to move said engaging means to said non-latching position; a switching circuit for connecting said starting coil
Abstract: In a single lens reflex camera, a lever responsive to operation of a shutter button initiates timing of an electronic shutter control a predetermined time interval before the shutter is actually opened. The predetermined time interval corresponds to the time elapse between the moment the shutter control changes the current which operates the magnet that holds the shutter open and the moment the magnet actually causes the shutter to close. After this predetermined time interval the shutter is opened, such as by running of the opening screen. After the measured shutter interval has ended, a current in the shutter control changes and operates on a magnet which has been holding the shutter open and causes the magnet to close the shutter, such as by releasing a closing screen.