Abstract: A motion picture camera having a film transport mechanism driven by an electric motor having an electronic speed control circuit which may be controlled by the camera operator so as to modify the speed of the motor and consequently the film transport velocity for the selection of various picture frequencies or frames per unit of time both above and below a normal picture frequency for normal shooting thereby permitting both time lapse and slow motion photography during use, the motor speed control circuit permitting the motor to be returned to its normal film speed automatically, together with an automatic aperture control circuit and a picture frequency indicator which may be observed by the operator during the operation of the camera.

Abstract: A basic lens for a pancratic camera lens system having an afocal screen of variable enlargement in which the screen includes a primary, positive front component, second and third negative components, the total focal length of the second negative component being displaceable of the optical axis and the minimum focal length of the second negative element and the image field diagonal 2.sub.y having a relationship (f.sub.Gmin - f.sub.II)<6y, and a fourth positive component, the basic lens being constructed in the form of an assembly of six lenses including, in succession beginning with the lens facing the object to be photographed, a first biconvex lens, a second biconvex lens, a first biconcave lens cemented to the second biconvex lens, a second biconcave lens, a third biconvex lens and a positive meniscus, all arranged in aligned relationship in the direction of light incidence.

Abstract: The invention concerns a device for adjusting the rotational speed of a drive mechanism preferably of the type used in a movie projector and provided with a drive motor having a stationary fixed stator, a rotor rotating in only one direction and connected to a friction wheel with at least one, preferably two, oppositely disposed friction discs fixed on a drive shaft for driving engagement with the friction wheel, the friction wheel being adjustable with respect to the friction discs in a radial direction to thereby adjust the rotational speed of the driving mechanism.

Abstract: A cine camera for taking talking pictures, in which a film is moved intermittently past an image gate by a reciprocating traction claw and continuously past a recording head by a rotating capstan coacting with a pinch roller, includes a latch by which the pinch roller can be held spaced from the capstan in an inactive position. The latching of the pinch roller in this inactive position, against the force of a biasing spring providing the necessary contact pressure during filming, is accomplished upon deactivation of the film drive by the residual kinetic energy of an inertial mass such as a flywheel which is coupled with either the capstan drive or the claw drive. The latch is released upon actuation of a trigger, either directly or through the intermediary of the claw drive. The biasing spring may be part of a toggle mechanism tripped by a presetting member, such as a sensor detecting the presence of a sound-film cassette in the camera.

Abstract: A camera of variable focal length is equipped with an indicator which signals the existence of a condition unsuitable for the taking of pictures because of the risk of blurring. The indicator is controlled by a sensing circuit taking into account such parameters as focal length, exposure time and, possibly, the steadiness of the camera support.

Abstract: A device for determining the position of at least two objects movable relative to each other preferably in a pre-set counter train which includes operatively associated optical elements supported on the objects together with a transmitter for emitting a directional beam such as an electromagnetic wave transmitter for producing an electromagnetic beam and a receiver onto which the beam is directed, the beam being directed in a unidirectional path onto the receiver when the optical elements are in a predetermined aligned position and being deflected from such path to an extent corresponding to the relative position of the objects and the optical elements supported thereon to provide an output from the receiver responsive to relative position of the objects.

Abstract: The housing of a motion-picture camera has a cassette-receiving space into which at least one feeler projects to detect the insertion of a sound-film cassette differing in shape from a silent-film cassette. With both types of cassettes the film is intermittently transported past an image gate by a traction claw; in the case of a sound-film cassette a portion of the film downstream of the image window is accessible for engagement by a constant-speed feeder in the vicinity of a sound-recording head. The feed rate of the traction claw is stabilized by a centrifugal governor in the presence of a silent-film cassette; upon sensing a sound-film cassette, the feeler deactivates the governor and synchronizes the claw drive with the constant-speed feeder under the control of a mechanism, such as a loop detector, which measures the length of film between the image gate and the recording head.

Abstract: A film strip is continuously advanced past a film gate of a camera or a projector while light coming from the strip through the film gate is reflected by a pivotable mirror keeping a beam of light trained upon a specific area of the strip, i.e., a frame, during a major part of a recurrent operating cycle. The mirror is reciprocated during each operating cycle under the control of an electrical signal generator synchronized with the strip-feeding mechanism, either directly or through markings (e.g., perforations) on the film strip, and performs a relatively slow forward sweep followed by a relatively fast return sweep, the latter being effected by a pulse of one polarity immediately followed by a pulse of opposite polarity arresting the mirror drive. In one embodiment (FIG.

Abstract: A camera of the reflex type comprises a view finder with an achromatic finder objective, an eyepiece, and an interposed inverting lens group. The finder objective includes a negative-meniscus lens of relatively low Abbe number and a biconvex lens of relatively high Abbe number. The negative-meniscus lens, which has a concave forward surface, may be air-spaced from the biconvex lens or may be cemented thereto to form a doublet; in the latter instance the doublet is preceded by a positive, biconvex or planoconvex, front lens.

Abstract: The invention relates to a recording- or reproducing apparatus for a strip-type information carrier having different operating modes and comprising an intermittent drive mechanism including a cam device rotatable about at least one axis. A carrier is movable relative to the cam device and has at least two positions corresponding to different operating modes; at least two cam followers are provided for engagement with the cam device. The cam followers are arranged in spaced relation on the carrier, each cam follower having an operative and at least one inoperative position in dependence on the position of the carrier. The respective cam follower transmits movement from the cam device for the intermittent drive of the information carrier only in its operative position. The apparatus further comprises a mode control device which is operatively connected to the carrier and controls the positions thereof.

Abstract: To facilitate visual and/or electronic determination of the shape of a light-reflecting test object, a source of coherent light such as a laser produces an illuminating beam and a reference beam, the latter beam being combined in an optical system with reflections of the illuminating beam from the test object to form a holographic pattern on a receiving surface. The optical system includes a main objectives and two ancillary objectives, these ancillary objectives focusing the reflected rays of the illuminating beam and the rays of the reference beam upon two substantially coincident points so located on or near the axis of the main objective, in non-conjugate relationship with the receiving surface, as to train upon that surface a defocused composite beam producing a holographic pattern of contour lines. The substantially coincident points also lie in or near the plane of a real or virtual aperture stop, such as a pinhole diaphragm or its image.

Abstract: A zoom lens assembly has a normal-range finder which is operable at all settings of a macro-range finder. The normal-range finder produces relative movement between two lens elements one of which is also positionable by the macro-range finder. This is achieved in one arrangement by controlling the positions of the lens elements with two coaxially arranged tubes which are coupled together for rotational movement but which can be moved axially with respect to one another by the macro-range finder. In another arrangement a single control tube is used to shift the two lens elements in response to adjustment of the normal-range finder but one of the lens elements is also displaceable within the control tube by rotation of a threaded mounting cylinder.

Abstract: A lens system for a camera comprises a pair of axially shiftable components for varying the focal length, coupled with a cylindrical zoom-control member, and a further axially shiftable component for changing the object distance, coupled with a cylindrical focusing-control member. An operating tube coaxial with the two control members engages the zoom-control member for rotating same, the focusing-control member being releasably entrainable by the zoom-control member between a limiting macro-range position and a close-up position through a deactivable coupling which may include two coacting lugs on these members or a pawl on the zoom-control member retractable by an axial shift of the operating tube. A toothed detent ring, nonrotatable but axially slidable, is also movable by that tube into engagement with the focusing-control member for arresting same against the force of a biasing spring urging that member into its limiting macro-range position.

Abstract: If a cine film is to be projected to the accompaniment of a sound track on a separate tape it is necessary to cheek that the film and the sound track are correctly coordinated. This is ensured by reading a code mark from the sound track and using it to slow or stop the motion of the film. The point at which the film motion is slowed or stopped is used to evaluate the relative position of the film with respect to the sound track and thus check that correct coordination is present. This evaluation may take place visually or automatically. In the latter case the prolonged presence of a correlation marking on the film in a sensing position can be used to signal the existence of correlation whereas the absence of such marking may energize a warning lamp or deactivate the film drive.

Abstract: A pancratic wide-angle objective comprises a stationary negative front component in the form of a single meniscus with a convex forward surface, an axially movable intermediate component consisting of a biconvex lens, and a stationary multilens positive rear component separated from the front component by an airspace greater than the focal length of the latter. The individual focal lengths of the front, intermediate and rear components have absolute values in a ratio of approximately 4:5:3.

Abstract: A varifocal objective has an axially shiftable positive front component, an axially shiftable negative intermediate component, and a fixed positive rear component or basic lens group. The latter component consists of five closely spaced lens members, all but the second of them singlets and all but the third of them positively refracting. The intermediate component is separated from the rear component by a diaphragm space which in a position of close approach of these components, corresponding to maximum focal length, is still substantially greater than any air space between the lens members of the rear component. With a varifocal ratio close to 3:1, the distance between the front and rear components is the same in the positions of maximum and minimum focal lengths.

Abstract: A method and an apparatus are described to enable one of two independently driven strips to be stopped for a predetermined period and then restarted in synchronism with the other strip which has been running continuously. Stoppage markers are provided on the first strip and synchronizing markers, which are interrupted when this first strip is to be stopped, are provided on the second strip. An integrator accumulating the output of a first sensor, responsive to the synchronizing markers on the second strip, feeds a coincidence circuit, also receiving the output of a second sensor responsive to the appearance of a stoppage marker on the first strip, which arrests the drive of the latter strip upon detection of a stoppage marker and restarts that drive after a period of interruption determined by the time constant of the integrator.

Abstract: A cine camera having a rotary or reciprocating shutter driven by a motor is provided with a supplementary diaphragm which cooperates with the shutter during acceleration of the motor to its rated speed to reduce the effect on the first film frame or frames of the change in exposure time occurring during the acceleration period of the motor.

Abstract: An electronic switching system for the control of a load, such as a motor serving to adjust the diaphragm of a motion-picture camera, comprises a normally inactive comparison circuit including a transistor bridge with a pair of NPN transistors in one pair of adjoining arms and a pair of PNP transistors in the other pair. Two complementary transistors in each half of the bridge, lying between diagonally opposite corners, are provided with a common biasing circuit shunted across that bridge diagonal, the load being connected across the other bridge diagonal. Each biasing circuit includes a resistive voltage divider with taps joined to the bases of the associated bridge transistors and a group of cascaded ancillary transistors connected across a section of the voltage divider containing one of these taps. The first ancillary transistor of each cascaded group has its base connected to an associated input terminal receiving a switching signal and a reference voltage, respectively.

Abstract: A main lens unit having a fixed focal length and consisting of a positive lens member is preceded by an afocal forward lens unit having a variable magnification and consisting of a positive forward lens member, a negative intermediate lens member which is axially movable to change the magnification, and a positive rear lens member. The intermediate lens member is arranged to direct divergent bundles of rays to said rear lens member. The rear lens member is arranged to convert said divergent bundles or rays into bundles of rays which are substantially parallel to the optical axis of the lens and to direct them to said main lens unit. The forward lens member is axially movable to control the position of the image plane. The lens is designed to meet the conditionf.sub.min -f.sub.11 < 6ywhere f.sub.min is the smallest focal length of the lens, f.sub.11 the focal length of the intermediate lens member, and 2y the image field diagonal.