Abstract: Method and apparatus for increasing the visibility of low contrast images. In accordance with the invention, the visibility of a selected area of an image is increased relative to another area of said image which differs only slightly in brightness from said selected area by causing said selected area to periodically vary in brightness while maintaining the brightness of said other area constant.The apparatus for carrying out the invention comprises an optical circuit including an electro-optic photosensitive storage device having a photosensitive characteristic in which the conductance of the device varies as a function of the intensity of the radiation incident upon it, and an electro-optic birefringent characteristic in which the birefringence varies as a function of an electric field applied across it. An image of an object is read into the device which is then read-out onto a screen by placing the device between two polarizers in a readout light beam.

Abstract: Transfer apparatus for receiving a printing plate from a first station in a first horizontal orientation and for transferring the plate to a second station in a second orientation which is both vertical and rotated 90.degree. relative to the first orientation. The apparatus comprises a receptor bin for supporting the plate, which receptor bin is, in turn, supported solely by a single rotatable shaft. By mounting the shaft to the receptor bin at a precise angular orientation, rotation of the shaft about its own axis will carry the receptor bin and the plate supported on it from the first orientation to the second orientation to transfer the plate to the second station.

Abstract: An acousto-optic deflector that utilizes second order diffraction in a birefringent crystal provides doubled resolution while maintaining high diffraction efficiency. For the second order birefringent deflector employing a paratellurite crystal, 1200 spot resolution was achieved with a 24 MHz bandwidth and 25 .mu. sec access time. This maximum number of spots is twice that obtainable in a conventional first order acousto-optic deflector.

Abstract: A plurality of outwardly and radially extending font segment support arms are coupled to a central hub which is rotated to sequentially present the letters formed upon the segments to an optical imaging station which selectively projects optical images of the letters upon a photosensitive medium. Vertical shoulder portions are precision machined upon outer portions of the radially extending support members for precisely positioning the arcuate character tracks on the segments with respect to the imaging station. Horizontal plates are affixed to the radially extending support members to support the segments against gravity and centrifugal force is employed to precisely seat the segments against the vertically oriented shoulder portions upon rotation of the hub.

Abstract: A magnification signal of 64 - 100% is applied as an input parameter to a specially designed relaxation oscillator which produces a pulse train wherein the pulses thereof have a duration which vary in linear fashion with respect to the magnification input signal, the relaxation oscillator employing a constant current source in series relationship with an integrating capacitor which produces a saw tooth signal having a slope which is constant regardless of variations in the amplitude of the magnification input signal. The output pulses from the relaxation oscillator are counted to define an exposure control interval which changes linearly with respect to the input magnification signal.

Abstract: Apparatus for recording a serial line of electrical data as a spatial array of optical data. The apparatus employs an acousto-optic device through which the electrical signal to be recorded is passed as a continuous acoustic wave. The device is illuminated by a laser and imaged onto a recording medium to form an image of the acoustic wave passing through the device. By pulsing the laser just as the acoustic wave fills the device, a line of optical data can be recorded which will correspond to the acoustic wave in the device. By indexing the recording medium and reimaging every time a new acoustic wave just fills the device, an entire raster may be recorded.

Abstract: A protective container for font disc segments. The container includes a housing portion for supporting the segment and a cap portion for closing the housing portion and, at the same time, for locking the segment against movement within the housing portion. More particularly, the housing portion includes an inner casing supported within an outer casing with the inner casing being of relatively flexible material and having side wall portions extending beyond the top opening in said outer casing. After insertion of the segment into the inner casing, the cap portion is placed around the extended wall portions of said inner casing and, in doing so, will not only close the container, but will also force the walls of the inner casing inwardly against the segment to positively lock it against movement. Upon removal of the cap portion, the side walls of the inner casing will spring outwardly to release the segment for easy removal from the housing.

Abstract: A linear measuring system for precisely measuring distances along a rather long measurement axis. The apparatus includes an endless measuring cable which is held under tension between a metering drum at one end of the system and an idler drum at the other end. The measuring cable is wrapped around a groove, which has a semicircular cross sectional shape, on the circumference of the measuring drum, and is wrapped similarly around the idler drum. The cable is coupled to an object, the movement of which is to be measured, and movement of the object results in linear movement of the cable and rotational movement of the metering drum. A rotary encoder, which produces a digital output signal, is coupled to the metering drum to measure linear movement of the object. The accuracy of the measurement depends upon maintaining a constant measuring diameter of the metering drum and the measuring cable, and also upon maintaining a tight frictional bond between the measuring cable and the metering drum.

Abstract: Apparatus for supporting a sheet of photosensitive material in the image plane of an optical imaging system for exposure thereat. The apparatus includes a first cover plate assembly having a transparent cover plate and a second backing plate assembly including a relatively flexible backing sheet. The cover plate assembly is driven into contact with the backing plate assembly with the photosensitive sheet to be exposed supported therebetween such that an air-tight chamber is defined between the cover plate assembly and the relatively flexible backing sheet. The air-tight chamber is then evacuated through the cover plate assembly, and as it is evacuated, the flexible backing plate will be sucked towards the cover plate assembly and drive the photosensitive sheet into firm contact with the transparent cover plate.By the use of the flexible backing plate, the chamber can be evacuated very rapidly, for example, in two or three seconds.

Abstract: A main programming memory device is coupled to an arithmetic logic unit through controllable gating circuitry which permits the majority of control data within the main memory to be sequentially transmitted to the arithmetic logic unit for control of arithmetic data therein. An instruction designation source controls a main memory address device which in turn is coupled to the main programming memory to initiate data readout to the arithmetic logic unit, through the gating circuitry, such instruction designation source also being coupled to a function memory which contains arithmetic logic data unique to particular instructions to be executed.

Abstract: A contact screen positioning device supports a flexible bowed halftone screen over a vacuum platen having a sheet of film thereon so that as the positioning device moves slowly down over the vacuum platen, central portions of the contact screen initially press against central portions of the platen and less and less centralized portions thereafter sequentially press against less and less centralized portions of said vacuum platen, to produce a rapid sweeping of air toward outer portions of the platen for rapid positioning of said screen over said platen without entrapped air pockets being formed between the screen and the film on the platen.

Abstract: An automatically focusing optical system for copiers, duplicators and other reproduction equipment having a variable magnification capability. The auto-focusing mechanism comprises a camming means for moving a mirror or other component of the optical system to maintain focus throughout the magnification range of the system. The camming means is additionally designed to be adjustable in such a way that it can accommodate imaging lens systems which differ in focal length within the normal manufacturing tolerance band, and thus replace the family of cams utilized in the prior art to accommodate lenses of different focal length.

Abstract: A solar energy collector of low cost and high thermal efficiency is disclosed having a heat trap produced by zigzagging a thin strip of polyethylene terephthalate between opposite sides of the trap while wrapping the strip about rows of dowels positioned at opposite sides of the frame of the solar collector. A window of soda lime glass filters UV radiation to inhibit discoloration of the plastic heat trap walls. An absorber plate having fluid pipes therein is positioned underneath the heat trap and a first layer of fiberglass, and a second layer of polyurethane foam are positioned below the absorber plate. The fiberglass layer prevents overheating of the polyurethane foam layer to in turn inhibit the formation of toxic fluids, which may condense upon the underside of the window to reduce the efficiency of the collector.

Abstract: A phototypesetter is disclosed having a stepping motor which actuates an escapement carriage coupled to an elongated carriage driving member. A projection lens carriage and a collimating lens carriage are selectively electromagnetically coupled to the elongated driving member, thereby to project images of varying character sizes through a focusing lens coupled to the escapement carriage, which sequentially projects focused character images across a photosensitive film on a line by line basis. A track select mirror is also selectively electromagnetically coupled to the elongated driving member for selectively projecting one of a plurality of tracks bearing characters of differing fonts carried by a rotatable font carrier element.

Abstract: An electronically tunable optical filter is described wherein an optical beam is diffracted by an acoustic beam the group velocity of which is noncollinear with the optical beam transmitted through the birefringent crystal medium. The frequency and the direction of the phase velocity of the acoustic wave are chosen for a given incidence direction of the optical beam so that the diffraction occurs for a band of optical frequencies centered about a predetermined optical frequency and a relatively large angular distribution of incident optical beams.

Abstract: A two-part replaceable cassette-like device is provided, having a disposable cassette portion and a light sealed buffer box, having a pair of drive rollers therein and which is detachably fastened to the disposable cassette, whereby the photosensitive material driven out of the cassette will be driven through the light sealed buffer box into a camera processor. Upon exhaustion of the photosensitive media within the cassette, the buffer box is removed from the cassette for reuse and the cassette is thrown away. A gear coupled to the buffer box roller material drive means is automatically rotated during insertion and withdrawal of the buffer box to and from the camera due to roller contact with a stationary drive gear positioned within such camera.

Abstract: For variable letter sizes being photographically recorded in a second generation phototypesetter, it is desired to increase generated quantities of light flux produced by the flash lamp operating in conjunction with a font disc where larger letter sizes are thereby imaged upon the photosensitive medium, and conversely, to reduce such flux where smaller characters are to be projected. The disclosed system employs a digital letter size code for controlling the amount of charge inserted into a storage capacitor via a digital to analog converter and multivibrator. When the flash lamp is triggered at the appropriate time to selectively illuminate a given character, the energy associated with the stored charge is employed to energize the lamp.

Abstract: A solar energy collector of low cost and high thermal efficiency is disclosed having a heat trap produced by zigzagging a thin strip of polyethylene terephthalate between opposite sides of the trap while wrapping the strip about rows of dowels positioned at opposite sides of the frame of the solar collector. A window of soda lime glass filters UV radiation to inhibit discoloration of the plastic heat trap walls. An absorber plate having fluid pipes therein is positioned underneath the heat trap and a first layer of fiberglass, and a second layer of polyurethane foam are positioned below the absorber plate. The fiberglass layer prevents overheating of the polyurethane foam layer to in turn inhibit the formation of toxic fluids, which may condense upon the underside of the window to reduce the efficiency of the collector.

Abstract: Film transport apparatus for phototypesetters. The apparatus includes upper and lower guide plates supporting pinch and drive rollers, respectively, between which a strip of film is frictionally fed. A pair of hold-down rollers are provided to press the upper guide plate against the lower guide plate to maintain the pinch and drive rollers properly positioned against each other, and also to help keep the apparatus locked together during operation. The upper guide plate is designed to be laterally slidable relative to the lower guide and further is provided with a pair of notches cut into its sides. Accordingly, to load film into the apparatus, it is only necessary to slide the upper guide plate until the hold-down rollers become aligned with the notches at which position the upper guide plate can be lifted up and away from the lower guide plate to separate the pinch and drive rollers for film loading.

Abstract: An automatic freeze protection system for solar energy collector apparatus. The apparatus includes a solar collector for circulating water or another fluid to be heated by the sun. Sensor means are provided within the collector to monitor the temperature of the water, and whenever it approaches the freezing point, the sensor will automatically actuate a valve means to rapidly drain the water from the collector. When the temperature within the collector thereafter rises to a predetermined safe level, the sensor means will again automatically actuate the valve means to refill the collector with fresh water to be heated. The system provided thus avoids the need for anti-freeze or other freeze protection materials suggested by the prior art as well as isolated water loops, heat exchangers and other expensive safety equipment necessitated thereby.