Abstract: A slide tray position sensing arrangement is provided for slide projector apparatus. The slide tray position sensing arrangement is arranged at a detection station. A coded aperture ring is provided that moves in a manner correlated to the movement of a slide tray turntable. The slide tray turntable carries the slide tray that holds the slides for projection and also functions as a tray transport arrangement. The coded aperture ring includes two circumferential arrays of apertures. Each of the apertures in the first array corresponds to a controlled slide position of a first tray type; e.g., an 80 slide tray. Each of the apertures in the second array corresponds to a controlled side position of a second tray type; e.g., a 140 slide tray. The slide tray position sensing arrangement is controllable to selectively sense the appropriate array of apertures corresponding to the slide tray type being utilized.

Abstract: Control apparatus is provided for a slide projector to accurately control rotation of a slide tray to predetermined slide positions of the slide tray and to provide integrated control of the slide change function at each slide position. The control apparatus operates in a forced mode between slide positions and operates in a servo mode to accurately position the slide tray at each of the predetermined slide positions. The detection of the slide positions utilizes a circumferential, apertured ring carried on a movable turntable that also carries the slide tray; the ring including a single incremental position aperture corresponding to each of the slide positions. Dual photodetectors are positioned at a sensing station to sense the respective slide position apertures, to provide differential position feedback detection signals in a servo loop, to interrupt the forced mode of operation and for controlling the stopping and positioning of the slide tray to a selected slide position in the servo mode.

Abstract: A slide transfer and shutter control arrangement is provided for a slide projector including a simplified shutter control arrangement and a positive acting slide sensor arm that is slidably mounted for shifting translation. Slide transfer is accomplished by a vertically movable lifter arm operated by a level wind screw. The level wind screw also operates a cam actuator. The cam actuator moves up and down with the lifter arm to actuate a slider member. The slider member controls the position of the slide sensor arm and provides shutter latch control. The slide sensor arm retains the shutter in the closed position when no slide is present and the slider member is actuated by the cam actuator to release the shutter latch. When a slide is sensed by the slide sensor arm, the slide sensor arm releases the shutter for projection of the slide at the slide transfer station. Slide face tension is appropriately provided by a face tension arrangement under the control of the cam actuator.

Abstract: A servo control arrangement is provided that accurately controls the positioning of a movable member. The movable member is controlled by a motor through a drive train. A coded member is carried either by the drive train or the controlled movable member so as to move in accordance with the controlled movable member. The coded member includes an array of apertures with each of the apertures corresponding to a controlled position of the controlled movable member. In a preferred arrangement, the controlled movable member is a rotary turntable that carries a slide tray for projection apparatus. In that arrangement, each of the apertures corresponds to one of the slide positions of the rotary turntable and slide tray. Feedback information representing the position of the coded member is provided by alternately energized light sources and a single photodetector device.

Abstract: A slide tray position sensing arrangement is provided for slide projector apparatus. The slide tray position sensing arrangement is arranged at a detection station. A coded aperture ring is provided that moves in a manner correlated to the movement of a slide tray turntable. The slide tray turntable carries the slide tray that holds the slides for projection and also functions as a tray transport arrangement. The coded aperture ring includes two circumferential arrays of apertures. Each of the apertures in the first array corresponds to a controlled slide position of a first tray type; e.g., an 80 slide position tray. Each of the apertures in the second array corresponds to a controlled slide position of a second tray type; e.g., a 140 slide position tray.

Abstract: A wet modular film printer having a plurality of removable modules upon which film printer components are mounted including a liquid immersed, capstanless printing head. The printing head immersion liquid is continuously recirculated and filtered by means of a recirculation draw off near the top of the liquid surface and a recirculated liquid return downstream of the printed head. Liquid containing areas are all enclosed and a negative pressure is maintained to remove any noxious vapors. After printing, the liquid remaining on the raw stock and the negative is removed by a series of wipers, an air stripper and a drying column. The drying column uses heated air which flows countercurrent to the direction of film movement so that the air is progressively hotter along the film's path of movement.

Abstract: The system has a variator lens and a compensator lens which are mutually displaceable for varying the focal length of the optical system. In the normal zoom range, the focal length is adjustable between a telephoto condition and a wide angle condition, in accordance with the positions of the variator and compensator lenses. The system has macro capability in both a range beyond the extreme telephoto end of the zoom range and also in a range beyond the extreme wide angle end of the zoom range. In at least the macro range at the telephoto end, the slots in the camming sleeve for the variator and compensator lenses lie substantially in planes.

Abstract: A recursive digital filter is disclosed for removing noise from an incoming television signal. The filter couples the incoming television signal to a subtracter without substantial attenuation of the television signal. The subtracter also receives at an input an attenuated difference signal comprising a selected amplitude of the difference between the incoming signal and an earlier received signal which has been delayed for an interval corresponding to one television frame. The subtracter subtracts the attenuated difference signal from the incoming signal and develops an output in which noise is substantially reduced.

Abstract: A control circuit is provided in projection apparatus to control the operating characteristics of the projection lamp. The projection lamp control circuit maintains a constant illumination output and color temperature of the projection lamp to provide improved operation and increased lamp operating life. The desired operating point of the projection lamp is accurately maintained by sensing the operating point of the projection lamp and utilizing the sensed deviation from the desired operating point to vary the output of a blower that provides cooling of the lamp. Thus, the operating point and color temperature of the projection lamp is accurately maintained in a closed loop arrangement by sensing the operating point of the lamp and controlling the blower output.

Abstract: A color-separating prism arrangement for a small portable video camera having solid-state detectors about 0.35 inch in height includes three prisms with the first and second prisms being separated by an air gap, and color separation occurring at respective spectrally selective dichroic plates between the first and second prisms and the second and third prisms, respectively, the separated color components being directed in different directions. The specific geometry of the system provides a prism assembly which is extremely small and compact, having an overall length of about 1.1 inches and an entrance face height of about 1 inch, and with each of the exit faces of the assembly having an effective height of about 1/2 inch.

Abstract: Apparatus for sequential cyclic operation of a plurality of magnetic tape playing devices. A single side of each tape in each device is played one after the other until all the devices have been operated. Then the other side of the tape is sequentially played. The operation of the device is controlled by logic circuitry responsive to an end-of-tape sensor to operate the next device, switch the tape drive mechanism of the device just operated to play the other side of the tape when activated, and finally to switch off the previously played device. A trouble indicator responsive to the failure of the drive mechanism to be switched from one way of operation to the next is also disclosed.

Abstract: Disclosed is an optical design for a variable focal length lens of large effective aperture which is focusable over an extended range including the "macro" range and is provided with a high degree of correction.

Abstract: A changeover control arrangement is provided for projection apparatus to allow two identical projection apparatus with identical changeover control arrangements and interconnected by a multi-conductor changeover interconnection cable to be utilized alternately and sequentially for multi-reel presentations or other projection formats requiring the operation of more than one projection apparatus.The changeover control arrangement of each projection apparatus includes a momentary actuated changeover control switch that is interconnected over the changeover interconnection cable to activate an illumination generating source; for example, an LED device. The illumination generating source has no electrical connections to the electrical or ground reference system of the projection apparatus in which the illumination generating source is physically disposed.

Abstract: The present invention provides an improvement in a card reader type audio visual teaching device. The device employs a card handling mechanism for moving an information card which may contain both audio and visual information, across a record/playback transducing head. A dual track magnetic stripe on the information card carries instructor information or a question on one track to be audibly reproduced by the device which a student can hear through a speaker or preferably a set of headphones. A microphone permits a student to record an attempted repetition or response on the second track. The improvement comprises a multispeed card transport drive mechanism which permits either the student track or both the instructor track and the student track to be driven past the record/playback head at a substantially reduced rate. Additionally, the transport drive mechanism includes a repeat mechanism for returning the card to an initial position.

Abstract: A system is described for replaying, in any selected sequence, programs recorded on a tape. The system is adapted to read a tape having tape location information and program location information thereon. In a preferred embodiment, a keyboard is included for selecting desired programs for replay in any sequence. In response to that selection, a controller determines from the program location information where the selected programs begin and end on the tape and causes those programs to be replayed in the sequence selected.Preferably, the system also permits replay of any tape segment or part of a recorded program by operator input of tape location information corresponding to the starting and stopping tape locations of the selected tape segments.

Abstract: A system is described for selecting and replaying desired tape segments of a recorded tape, a video tape for example, in any predetermined sequence. The system accepts an operator's designation of which segments of the tape are desired for replay and in which sequence those segments are to be replayed, irrespective of the location of the selected segments on the tape. An electronic controller, responsive to the operator's designations, causes the playback machine to replay each selected tape segment in the proper sequence.

Abstract: The optical system in the binoculars includes a pair of sets of optical elements respectively on a pair of carriages mounted in an hermetically sealed housing. These carriages are moved by an external control toward and away from each other in order to vary the interpupillary distance between the two sets of optical elements. A transparent window or windows are located in front of the sets of optical elements and are hermetically mounted on the housing. The windows are large enough to be aligned with the sets of optical elements throughout the range of movement thereof.

Abstract: One or more remote control arrangements are provided for interconnection to projector apparatus including local controls. Each of the remote control arrangements includes momentary actuated push-button controls for independently controlling the forward, reverse and stop drive modes and the on and off lamp status of the projection apparatus. Each of the remote control arrangements and the local control arrangement generate or synthesize a predetermined control signal corresponding to each of the drive modes and lamp status conditions from a signal waveform inputted to the remote control arrangements from the projection apparatus over one conductor of the interconnection cable between the projection apparatus and each of the remote control arrangements.

Abstract: The present invention provides a system for automatically focusing a projected film image by maintaining a predetermined distance along the optical axis between the emulsion on the surface of the film and the projection lens. The system includes a movable carriage for mounting the projection lens and an electro-optic sensor mounted for movement with the carriage for maintaining the predetermined distance. The electro-optic scanner includes a light source and lens assembly for focusing a beam of light onto the surface of the film and a lens for focusing the reflected image onto a dual phototransistor receptor. A servo-amplifier is connected to the output of the dual phototransistor to provide appropriate signals to the carriage drive mechanism to maintain said predetermined distance. The servo-amplifier utilizes both positional and rate feedback to provide faster operation and settling.

Abstract: Disclosed is an optical design for a variable focal length lens of large effective aperture which is focusable over an extended range including the "macro" range and is provided with a high degree of correction.