Abstract: Spot registration or position in an optical output device, such as a raster output scanner (ROS), may be controlled in a slow, or process, scan direction by interposing in the image path an electro-optic element whose angular dispersion varies for a given wavelength as a function of the electrical bias applied to it. By orienting the electro-optic element such that dispersion control is perpendicular to the fast or line scan direction of the ROS, varying the electrical bias applied to it varies the dispersion in the slow scan direction. The electro-optic element may be, for example, a prism of AlGaAs. Bias applied to the electro-optic element may be in response to the output of a means for detecting and quantifying such positional errors and/or in response to predetermined correction information output from a processor controlled memory unit or the like. Spot position for single or multiple beam optical output devices may be achieved.

Abstract: A multiple wavelength semiconductor laser includes a plurality of layers, one or more of said layers comprising a carrier confinement (multiple quantum well) active region of the type wherein at least two conforming regions (quantum wells) contained in the active region are formed such that one quantum level of a first region (quantum well) is at the same energy level as a different quantum level of a second region (quantum well). This alignment of the quantum levels between two confinement regions (quantum wells) results in the recombination of carriers from one region augmenting the recombination of carriers from the other region, the net effect being an output intensity at both shorter and longer wavelengths of operation more nearly equal than heretofore available. Appropriate placement of the regions within the laser waveguide also facilitates a matching of the output intensity profile with a desired output mode, e.g., the fundamental mode TEOO.

Abstract: A method of slow, or process, scan direction spot registration or position control in an optical output device, such as a raster output scanner (ROS), may be facilitated by interposing in the image path an electro-optic element whose angular dispersion varies for a given wavelength as a function of the electrical bias applied to it. By orienting the electro-optic element such that dispersion control is perpendicular to the fast or line scan direction of the ROS, varying the electrical bias applied to it varies the dispersion in the slow scan direction. The electro-optic element may be, for example, a prism of AlGaAs. Bias applied to the electro-optic element may be in response to the output of a means for detecting and quantifying such positional errors and/or in response to predetermined correction information output from a processor controlled memory unit or the like. Spot position for single or multiple beam optical output device may be achieved.

Abstract: In an optical output device wherein a beam of light is generated and focused to a spot upon an image plane, such as a photoreceptor in a xerographic printing apparatus, an apparatus for controlling the position of the spot in the slow scan direction of the image plane including a light source capable of emitting the beam of light at a selected one of at least two selectable wavelengths and beam deflecting means for deflecting the beam of light an amount which depends on the wavelength of the beam of light, the amount of deflection determining the position of the spot in the slow scan direction on the image plane. The light source may be of the solid state laser type, and may emit a plurality of beams of light the spots from which may be individually or together selectively positioned in the slow scan direction on the image plane. The beam deflecting element may be a semiconductor prism, for example of AlGaAs, and have a controllable bias applied thereto to allow further control of spot positioning.

Abstract: In an optical output device wherein a beam of light is generated and focused to a spot upon an image plane, such as a photoreceptor in a xerographic printing apparatus, an method for controlling the position of the spot in the slow scan direction of the image plane including the steps of generating a beam of light, deflecting the beam of light by way of an optical beam deflecting elements such that the optical beam deflecting element deflects the path of the beam of light by an amount that is determined by the wavelength of the light beam, and varying the wavelength of the beam of light such that the amount that the beam of light is deflected by the optical beam deflecting element is varied to achieve control of the position of the spot at which the beam of light is incident on the image plane in the slow scan direction.

Abstract: A lateral heterojunction bipolar transistor (LHBT) comprises emitter and/or collector regions forming a p-n heterojunctions at the emitter/base junction and at the collector/base junction with a planar base region wherein at least the emitter region is formed by employing impurity induced disordering (IID) to produce emitter or collector region of wider bandgap than the base region. The lateral heterojunction bipolar transistor of this invention can also double as a hetero transverse junction (HTJ) laser.

Abstract: A bicycle frame manufactured of one or more continuous fiber composite tubes, wherein the tubes are joined to one another without lugs by overlaying the joints with resin impregnated continuous fiber composite material and clamping the joints in static pressure molds. Gussets are integrally formed as part of the joints. One or more of the tubes may be metal, preferably, titanium. The bicycle frame is provided with metal drop outs which are also preferably titanium.

Abstract: A light sensing apparatus adaptable for inclusion in an array of such apparatus is operable independent of polling cycle providing a more accurate sensing of the patterns of illumination incident on an array of such apparatus. The apparatus facilitates utlizing each address line to simultaneously initialize one row of apparatus while enabling the subsequent row of apparatus. The apparatus is also compatible with elements capable of providing gain, given that the photosensitive element is separate from the path across which voltage or current is measured. The apparatus may be fabricated of amorphous silicon. The light sensing cell includes an input terminal, an output terminal, a conductive element electrically interconnecting the input and output terminals, a multiple-state sensing device, means for establishing an initial state of the sensing device, means for changing the initial state of the sensing device in response to the incidence of electromagnetic or ionizing radiation (e.g.

Abstract: Modulation-induced thermal crosstalk between the independently addressable lasers of a monolithic multilaser array is reduced by forming each laser with two optically coupled active regions, an amplifier region and a modulator region, biasing the amplifier region in such a way that stimulated emission is caused to occur therein, and varying the electrical condition of the modulator region in order to modulate the lasers. Modulation of the laser output is achieved by varying the internal optical loss of the modulator region, known as Q-switching. In one form, control of this loss is achieved by varying the reverse bias voltage applied to the modulation region. In another form, control of this loss is achieved by selectively connecting and disconnecting regions of p-type and n-type material in the modulator region together. In a third form, control of this loss is achieved by selectively connecting and disconnecting the modulator region to ground potential.

Abstract: Interstitial incorporation of Group III or Group V dopants, such as As, Sb, Ga, Al or B, in a III-V semiconductor, such as GaAs or Al.sub.x Ga.sub.1-x As, in the absence of any substitutional doping via a Group IV or Group VI dopant, will substantially eliminate, if not completely suppress, the formation of deep donor levels or DX centers in the III-V semiconductor.

Abstract: A form including user modifiable fields and an encoded description of the location, size, type, etc. of the fields allows direct programming of a form interpreter. Other information including the processing of the form, encoded data, etc., may be included in the encoded information. A system for creating forms carrying an encoded description of selected attributes of the fields includes means for selecting or creating fields and locating the fields on a form while generating, substantially simultaneously, the encoded description of the selected attributes. A form composer then allows merging of the form and its encoded description for printing or electronic transmission. A system for reading such forms includes a scanner, decoding device, and processor. By reading such forms, data may be entered into or recalled from a data processing system, or a form interpreter may be programmed, locally or remotely, for subsequent handling of forms.

Abstract: An image sensing apparatus of the type employing resolving and sensing means is provided with sensing means of selected size and geometry to allow approximation of arbitrary filter response. The sensing means of selected size and geometry may be incorporated into compact, self contained image resolving and sensing apparatus having a transparent substrate for resolving an incident image by refraction, diffraction or other suitable mechanism. The sensing means may be located directly on a surface of the transparent substrate. Logic and select circuitry may be integrally and simultaneously formed with the sensing means. The size and geometry of the sensing means may enable approximation to color inhibition and other effects to allow approximation of the spectral response of the human eye.

Abstract: A compact, self contained image resolving and sensing apparatus of the type used in electronic imaging applications includes a plurality of sensing devices such as photodetectors formed on a transparent substrate capable of resolving a polychromatic image incident thereupon. The mechanism by which the substrate resolves the incident image may be refraction, diffraction or other suitable mechanism. The sensing devices are sized and located on the substrate such that they are capable of detecting one or more wavelength components of the resolved polychromatic image. Logic and select circuitry may be formed on the substrate generally contemporaneously and of similar materials as the sensing device.

Abstract: A lateral heterojunction bipolar transistor (LHBT) comprises emitter and/or collector regions forming a p-n heterojunctions at the emitter/base junction and at the collector/base junction with a planar base region wherein at least the emitter region is formed by employing impurity induced disordering (IID) to produce emitter or collector region of wider bandgap than the base region. The lateral heterojunction bipolar transistor of this invention can also double as a hetero transverse junction (HTJ) laser.

Abstract: Monolithic high density arrays of independently addressable offset semiconductor laser emitters or elements are able to be placed in close center-to-center proximity, e.g., on 3-10 .mu.m centers, without experiencing any undesirable phase locking and with minimal amount of electrical and thermal interaction or crosstalk occurring between the independently addressed lasing elements and their independent operation in ROS printer applications. With a proper offset in the laser emitters, interlace scanning relative to an image bearing surface, which is required with other multiple emitter lasers in ROS printer applications, is eliminated thereby permitting adjacent line scanning of an image bearing surface without complicated optics and electronics.

Abstract: An acoustic ink printhead having improved ink drop ejection control includes a substrate having an array of acoustic lenses at its upper surface for bringing rf acoustic waves to a predetermined focus and a layer of acoustically reflective material of a thickness equal to an odd multiple of one quarter of the wavelength of the acoustic rf waves passing through it having openings corresponding to and positioned above each lens. Ink from an ink pool is allowed to couple acoustically to the lenses at each opening for receiving the focussed acoustic rf wave, while the layer acoustically isolates the interstitial regions between each lens by reflecting the acoustic rf waves incident on the upper surface of the substrate in those regions.

Abstract: Intermediate buffer films having a low plastic deformation threshold are provided for absorbing defects due to lattice mismatch and/or thermal coefficient of expansion mismatch between a substrate or layer support and an overlayer while concurrently providing a good template for subsequent crystalline growth at the overlayer. This is accomplished for diamond cubic structure substrates, such as Si or Ge or Si on sapphire or crystalline Si on glass, upon which are to be deposited lattice mismatch overlayers, such as, GaAs or ZnSe. Also, zinc blend type substrates, such as GaAs or InP may be employed with such intermediate buffer films. A characteristic of these intermediate buffer films is a substantially lower plastic deformation threshold compared to either the substrate support or the overlayer to be grown heteroepitaxially thereon.

Abstract: A BiCMOS voltage reference generator circuit generates and maintains a reference voltage within 3 mV over an 80.degree. C. temperture range and over a 1 volt change in power supply level. The circuit uses feedback from the output of the reference voltage generator to the current source supplying current to the voltage reference generator. This feedback increases the effective output impedance of the current source, making the reference voltage output substantially independent of power supply variations. The circuit operates with power supply differential as low as about 3 volts, and preferably is fabricated from bipolar transistors and MOS transistors on the same chip.

Abstract: A method for determining the transfer function of a data acquisition system involves inputting a set of bilevel input test patterns to the system and measuring the system's response. The input test patterns from a complete orthogonal set. The input test patterns or the system's response can be weighted to correct for aliasing error and/or to represent any arbitrary input waveform. From the ratio of the Fourier transform of the sum of the responses to the Fourier transform of the sum of the input test patterns the transfer function is derived. In operation, the transfer function is used to accurately determine the characteristics of any input waveform to the system.

Abstract: A high precision analog to digital converter comprises the combination of an imperfect or low resolution digital to analog converter having an error function known in terms of orthonormal components and an error compensating device capable of generating correction terms which do not interact with one another. The correction terms are based on orthonormal components namely, the Walsh function components, of each signal level to be compensated. At most only one weighting value per bit is required, the combination of which will compensate for errors of any bit combination. In a specific embodiment employing feedback compensation, the output of the low resolution converter and of the compensating device may be summed to produce a high performance, high precision converter with increased accuracy and resolution.