Abstract: A ribbon cartridge for a printer provides an unsupported length of ribbon between a pair of spaced guide means to provide for easy threading. In addition, continuous rotation of the ribbon is made possible by storing the ribbon as an endless loop in a random fashion in the principal cavity of the cartridge. A secondary cavity prevents an accidental loop from coming out of the cartridge which would otherwise result in slack in the unsupported length.

Abstract: A distributed feedback, (DFB) electrically pumped diode laser in which the spacing of the periodic structure within the diode is selected to optimize the interaction between the periodic structure and the electromagnetic waves in the diode laser. The degree to which the waves interact with the periodic structure is described mathematically by a coupling constant K, with larger values of K corresponding to lower gains required to produce laser operation. It is shown that in DFB diode lasers higher order transverse modes have a higher coupling constant K with the periodic structure than does the lowest order transverse mode and thus the higher order transverse modes will lase more easily than the lowest order transverse mode.

Abstract: A multiple switching apparatus comprising two spring-like switching members disposed in a tandem array with each integral with its metallic support base. The central area of each of the switching members is defined by a plurality of slots formed in the support base with the length and displacement of the slots defining the force-displacement characteristics of each switching member and, accordingly, of the tandem array. The top switching member moves downward until it produces a first switching function, with further movement of the top switching member effecting movement of the second switching member such that a second switching function is produced.

Abstract: An electrically pumped, distributed feedback laser having all side surfaces of the active laser medium cleaved and a periodic structure at a 45.degree. angle to all of the cleaved surfaces. Current confining channels restrict pumping current to selected regions of the active laser medium to provide sufficient feedback such that two parallel filamentary areas of the active medium lase. By having multiple lasing filaments the divergence of the output beam in the direction of the width of the filaments is reduced by a factor proportional to the number of filamentary lasing areas.

Abstract: A switching device having a movable contact element characterized by a set of unconnected, curved slots radiating outward from a central key area and equally spaced around the central key area. The radially extending unconnected, curved slots may be sections of a spiral, at least some of which sections overlap each other. Adjustment of the spring rate of the movable contact element is accomplished by adjusting the length of the slots or by regulating the distance of the inner terminus of the slots from a central point of the central key area. The movable contact element either contacts a second contact element for contact switching or approaches the second contact element for capacitive switching.A plurality of the switching elements can be formed in a planar array on a continuous metallic substrate to provide a keyboard. The movable switching elements can be formed on the metallized areas of a printed circuit board.

Abstract: A flying spot scanning system is provided which uses directed light from a scanning element, which directed light is reflected through a symmetrical arrangement of prisms for scanning across a medium with a planar object surface. Virtual scanners provide a segmented focal plane whereby the effective scan angle of the system is reduced.

Abstract: A method of making thin film devices with selective etchants. Specifically, a fabrication process in accordance with the invention provides for the manufacture of amorphous chalcogenide sandwich structures. Such structures consist of a glass substrate, a chromium or aluminum electrode on the substrate bounding one side of the chalcogenide layer, and a second electrode of aluminum bounding the other side of the chalcogenide layer. First, the aluminum electrode is etched without affecting the other layers. Secondly, the chalcogenide layer is etched with a solution which attacks only the chalcogenide material and neither the overlying aluminum nor the underlying chromium or aluminum electrode. This two-step process is particularly suitable for fabricating current controlled negative differential resistance devices which requires the precise registration of one of the electrodes with the boundary of the chalcogenide such that a coextensive boundary is achieved.

Abstract: A structure for providing arrays or individual hemispherical diodes and methods of producing the diodes. When the diode array is to be part of a configuration utilizing a substrate, the substrate is selected to have radiation transparency, a lower refractive index, and lattice constant and lattice structure similar to that of a crystal layer grown in hemispheres formed in the substrate. When the diode array is to be removed from the substrate, a material that can be preferentially etched is grown between the hemispheres formed in the substrate and the grown crystal layer that is to have light emitting areas.

Abstract: A high-speed printer with a printing wheel with the individual type elements supported by radially extending spokes. Separate servo systems provide intermittent movement for the printing wheel and the carriage carrying the printing wheel.

Abstract: A thermal printer comprised of a shift register, a line buffer and a plurality of printheads in heat-transfer relationship with a heat-sensitive record medium. The shift register and line buffer are comprised of a plurality of stages or modules with each module having an amorphous semiconductor heating element that exhibits current controlled negative differential resistance in heat-transfer proximity to a heat-gated amorphous semiconductor threshold switch which has a V-I characteristic which is strongly temperature dependent. The printheads are comprised of the amorphous semiconductor heating elements. Data is stored in the shift register by means of a video data signal and two oppositely phased clock signals of an amplitude that will only bias a heated threshold switch to conduction, with transfer of data to the line buffer being achieved in a parallel format by a third properly phased clock signal.

Abstract: A system for generating video information on a display medium which is characterized by a character generation of high quality, variant font definition, and font character off-set. The character generating means within the system provides means for selecting an external video source to be displayed alternative to the output from the character generator itself.

Abstract: A system for processing a plurality of audio signals to generate binaural output signals. The signal processor has a manually operated spatial position control which provides a correspondence between movement of the control and the binaural perception of movement by a listener at a listening position within an audio signal space. The spatial position control is essentially an electric circuit analog of a particular audio signal space, with means for obtaining variable binaural output signals from the circuit to simulate movement of the listening position in the signal space. One embodiment of the position control includes a mechanical linkage to a plurality of series ring connected potentiometers. The variable outputs from the wiper arms of the potentiometers are combined to produce the desired binaural output signals. The perceived orientation of the listening position in the audio signal space may be changed by selective combinations of potentiometer outputs.

Abstract: A method of forming a switching device having a movable contact that is an integral part of a metallic support substrate and is supported above the support substrate by a plurality of spring-like legs that are also an integral part of the support substrate. One or more of the switching devices is produced by forming one or more groups of curved, unconnected radially extending slots in a metallic substrate to define support legs, plastically deforming the legs defined by the slots past their elastic limit, and then precipitation hardening the complete structure. The slots can be formed by a photomasking technique followed by an acid etch with the etch being performed from both sides of the metallic support substrate. To provide a desired tactile response characteristic, and to assure movement of a central portion of the switching device past the plane of the metallic support substrate, a portion of each of the legs defined by the slots may be removed to thin that portion of each leg.

Abstract: Infrared radiation over a field of view is scanned in a first direction by an aximuth scan mirror and optically coupled to a spherical reflecting mirror. The scanned infrared radiation is reflected by the spherical mirror to a first surface of a vertical scanning mirror which forms an image on an adjacent detector array. The electrical signal output of the detector array, proportional to the intensity of the detected infrared radiation, is processed and coupled to an array of light emitting elements. The array of light emitting elements produces a visible image, corresponding to the infrared image, which is projected onto the other surface of the vertical scanning mirror, the visible radiation reflected therefrom being optically coupled to the rear surface of the azimuth scan mirror and thereafter to a recording medium or display device to produce a thermal image of the field of view.

Abstract: A system for automatically focusing images of different magnifications to be reproduced onto a light sensitive medium. First and second optical patterns of a wavelength to which the light sensitive medium is not responsive are projected from first and second displaced light pattern producing means to the projection plane of the images to be reproduced and back to the light pattern producing means. The light pattern producing means have transparent portions therein such that when the returned optical patterns are defocused portions of the defocused optical patterns are transmitted through the transparent portions. The transmitted light is then mechanically modulated and then converted to an electrical signal which is amplified, filtered and then demodulated to provide a signal having the polarity needed to drive a servo system such that focus of the images to be reproduced is achieved.

Abstract: A flux scanner which is comprised of a rotating polygon for scanning a beam of radiated flux transverse a photoreceptive medium. In the beam path between the flux source and the polygon, an astigmatic-beam expander lens is employed to focus the flux distributions to a spot at an image plane. The astigmatic lens is configured so as to produce a very narrow beam of flux to control the size of the spot in a direction orthogonal to the transverse direction, without any loss of efficiency. Between the photoreceptive medium and the polygon, a cylindrical lens and linear optical elements are positioned to focus the beam to control the size of the spot along the transverse direction. The transverse direction is designated optically as the tangential plane; whereas the direction orthogonal to the transverse direction is designated optically as the sagittal plane.

Abstract: A system for providing a predetermined phase relationship between signals representing the operation of first and second moveable members, the operation of said first moveable member being regulated in accordance with the operation of said second moveable member. The phase relationship is determined by comparison means which produces a pulse signal indicative of said phase relationship. Signal storage means, responsive to the pulse signal, produces an analog signal, the amplitude thereof varying at a first rate, the maximum amplitude attained by said analog signal being proportional to said phase relationship. The output of said signal storage means is coupled to signal generating means comprising variable gain means, said variable gain means being adjusted to correspond to a predetermined gain, said signal generating means generating an analog signal proportional to the signal stored by said storage means.

Abstract: Asynchronous high-speed film transport apparatus wherein supply and take-up reels have opposite ends of an elongated film wound thereupon. A pair of drive motors one for each reel is selectively operable to rotate the reels respectively to move film along a path from one reel to the other. First and second film vacuum chambers are associated respectively with the supply and take-up reels, each chamber being arranged to hold a loop of film, the chambers being positioned adjacent the film path between the reels. Means are connected to the drive motors for producing movement of the film and sensing means are provided for maintaining a predetermined loop of film in each of the chambers during film movement. Between the first vacuum chamber and a read/record station is a first clamp for the film and a storage device for controlling the film advance, the storage device including a movable member for controlling the length of a frame. A second film clamp is positioned opposite the read/record station.