Abstract: Precisely prefabricated glass plates are cemented on a precisely machined aluminum polygon employing ultraviolet sensitive cement. Each glass plate is aligned precisely and then fixed in place by application of U-V radiation which fixes the cement and thereby permanently affixes the glass plate to the aluminum polygon. Methods of employing this scanning system in flying spot scanning applications are also disclosed.
Abstract: Method and apparatus for accurately positioning a blank angular position transducer element for boring at its center. A relatively high frequency carrier signal is applied to the blank transducer element to be bored and is thereby induced in a master rotor element which is rotated at a constant speed in an operative relationship with the blank. The rotor is made deliberately eccentric with respect to its axis of rotation, and the induced signal contains a carrier signal, a component indicative of relative angular position, and a once-per-revolution eccentricity error component, if the blank element is also eccentric with respect to the axis of rotation. Error detection circuitry isolates the once-per-revolution eccentricity error component, and resolution circuitry resolves it into x and y directions for application to error display devices, or to actuators connected to move the blank transducer element automatically until the x and y components are both zero.
Abstract: Half-tone imaging is achieved in a flying spot scanning system wherein a highly collimated light beam is modulated with imaging information, reflected from a multifaceted rotating polygon and directed to a scanned medium through a light attenuating member. The latter member is supported proximate the imaging focal plane and orthogonal to the collimated, reflected light beam. The light attenuating member has an optical light transmission characteristic that varies in a continuous and cyclic pattern with a cycle period at least about ten times the maximum lateral extent of the collimated light beam, thereby serving to alter the system imaging from contrasting black and white patterns to half tones and gray colorations.
Abstract: A linear actuator for selectively moving an assembly relative to a support frame along a predefined linear path. The linear actuator includes a drive shaft having a cylindrical surface, means for rotatable mounting the drive shaft to the frame for rotation of the drive shaft about the axis of the cylindrical surface, and means coupled to the drive shaft for rotating same about such axis. A carriage forms part of the assembly with the remainder of the assembly being mounted to the carriage and including a roller. Means are included for mounting the roller to the carriage with the roller being rotatable about a first axis and pivotable about a second axis perpendicular to the first axis.
Abstract: A heterojunction diode laser which produces a highly collimated, polarized light beam perpendicular to the plane of the PN junction of the laser rather than through cleaved end faces in the plane of the PN junction. The diode laser includes a periodic structure which is buried at a heterojunction interface and in contact with a light waveguide layer. The periodic structure acts to produce the feedback necessary for lasing. If the spacing of the teeth of the periodic structure are an integer number of wavelengths of the light photons produced in the laser, the light beam exits at an angle perpendicular to the plane of the PN junction. If a tooth spacing is chosen that is not equal to an integer number of wavelengths of the light photons produced in the laser, the light beam may emerge from the diode at an angle other than the normal with the specific angle determined by the particular tooth spacing.
October 15, 1974
Date of Patent:
February 1, 1977
William Streifer, Donald R. Scifres, Robert D. Burnham
Abstract: An apparatus for removing contaminant particles from an enclosure containing a rotating magnetic disk by using the air flow created by rotation of the disk. A tacky substance is provided at a point of maximum centrifugal force within the enclosure so that contaminant particles are permanently captured. Means can be provided for refreshing the tacky substance.
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 reflective surfaces for scanning across a medium with a planar object surface. In each scanning cycle, information is transmitted to the scanned medium by modulating the directed light in accordance with a video signal.
Abstract: A flying spot scanning system is provided by utilizing reflected light from a multifaceted rotating polygon which is then directed to the scanned medium. A light source illuminates a portion of the mirrored sides of the polygon during each scanning cycle, to provide a desired sequence of spot scanning. In each scanning cycle, information is transmitted to the scanned medium by modulating the light from the light source in accordance with a video signal. An optical convolution of elements including at least two lenses having power in one optical plane and substantially no power in the other plane, is provided in combination with the polygon. One of these lenses is placed in the optical path between the polygon and the scanned medium with its power plane substantially parallel to the axis of rotation of the polygon for allowing a wide variance in runout tolerance of the scanning system.
Abstract: An acoustic residue algebra decoder having a plurality of acoustic channels with each channel having an input transducer and an output transducer. The number of acoustic channels is equal to the number of residue bases used in the decoder. An electrical signal is supplied to each input transducer of each acoustic channel with the frequency of the signal supplied being inversely proportional to the residue base of that acoustic channel. The spacing of the conductors of the input and output transducers of each acoustic channel are proportional to the residue base of that acoustic channel. Circuitry is provided in conjunction with the acoustic channels to provide a phase shift of each of the input signals with the degree of phase shifting being determined by the residue and the residue base.
Abstract: The invention relates to a position device which rides over a surface for controlling a cursor over a visual display. The device generates signals indicative of its position to cause the cursor to be displayed on the display at a corresponding position. The device includes a control mechanism that comprises a transport sphere coupled with rotatable shafts which represent the position of the device in terms of Cartesian coordinates. The sphere is in contact with the surface over which the device rides and the rotatable shafts contact the sphere at a position on the sphere approximately 90.degree. from the contact loci of the sphere and the surface.
Abstract: A character segment detection system adapted for use with conventional scanning apparatus comprising translating apparatus disposed to illuminate an area of a page, detection means disposed for sensing the level of reflected light within a predetermined aperture from the paper and for producing an electrical signal indicative thereof, peak detector means connected to the detection means for producing the output signal indicative of the peak of the electrical signal, differentiator means connected to the detection means for producing an output signal indicative of the first derivative of the electrical signal, rectifying means connected to receive the differentiator means output signal for producing an output signal of only one polarity indicative thereof and comparator means connected to receive the electrical signal and the peak detector means and rectifier means output signals for producing an output signal when the sum of the electrical signal and and the peak detector means signal is greater than the diff
Abstract: A shift register that utilizes a plurality of amorphous semiconductor threshold switches. The shift register is driven by a two phase clock with odd-numbered threshold switches being supplied a pulse waveform of one phase and even-numbered threshold switches being supplied a pulse waveform of a different phase. The threshold switches have a V-I characteristic that is strongly temperature dependent and each is heated by a heating element which can take the form of an amorphous semiconductor current controlled negative differential resistance device, with the current controlled negative differential resistance devices and the threshold switches fabricated simultaneously on a common substrate.
Abstract: Apparatus for supporting a carriage about an elongate shaft for linear movement of the carriage along the shaft. The apparatus comprises an elongate tubular housing to which a carriage may be mounted, the housing having opposing normally open ends, a pair of linear bearings mounted in the housing in spaced apart relation adjacent respective opposing ends thereof, the bearings having aligned openings for receiving an elongate shaft in contacting relatively movable relation, and means included in the housing for lubricating the bearings during movement of the housing along an elongate shaft disposed therethrough.
Abstract: A method of making a diode laser in which a pump current confining channel is formed on the n-side of the diode laser prior to the growth of the active region of the diode laser. The current confining channel is formed by providing two spaced regions in a substrate with the regions being highly resistive to current flow when the diode laser is forwarded biased. Preferably, the regions are formed by diffusion of an impurity into a substrate of a selected conductivity type so as to form secondary p-n junctions on both sides of an intermediate channel, with subsequent growth of other layers of the diode laser providing a primary p-n junction at the boundary of the active laser region. Forward biasing of the primary p-n junction results in reverse biasing of the secondary p-n junctions and pump current confinement to the channel.
Abstract: A laser having layers of a first material interleaved with layers of a second material with the first material having a different index of refraction and bandgap than those of the second material. The thicknesses of the layers of the first and second materials satisfy the relationship t = m .lambda./2n where m is the laser mode and n is the index of refraction of the material, such that the right and left going waves of the light produced by the layers of the first material when the laser is pumped are coupled and reinforced in a coherent manner by the layers of the second material such that reflections from the second material are in phase, thus allowing laser operation in the absence of discrete end mirrors.
Abstract: Method and apparatus for reducing X-ray dosage required for xeroradiographic examinations without reducing the relative information capacity of the images produced during the examination. In particular, a charged xerographic plate is positioned adjacent the object to be examined and penetrating X-ray radiation is projected through the object onto the plate surface, forming a latent electrostatic image on the surface of the plate. The penetrating radiation utilized is of a substantially lower dosage than normally utilized. The image is then partially developed with developing powder and the partially developed image is then charged and exposed to substantially uniform radiation. The exposed charged image is finally developed by applying additional developing powder thereto resulting in an enhanced image or signal.
Abstract: A buried-heterostructure (BH) diode injection laser capable of operating at low room temperature thresholds and in the lowest order TE, TM or TEM modes. The laser has an elongated groove in a substrate with the groove extending through a pump current confining layer with a central portion of the active layer substantially completely within the groove and substantially completely surrounded by light guiding and carrier confining layers of material having a lower index of refraction than the index of refraction of the material of the active layer. The light guiding and carrier confining layer in contact with the substrate has a central depression within the elongated groove and the central portion of the active layer is bowl-shaped and within the depression such that light waves produced by carrier recombination within the central portion of the active layer when the laser is forward biased are guided in the central portion of the active layer such that the laser produces a light beam having reduced width v.
Abstract: A switching device having as the active switching element a material with a band gap between 0.6 and 1.2 eV and a mean coordination number of 4. These parameters provide a material having a glass transition temperature that is relatively high such that the material is resistant to devitrification. Amorphous (a-) CdAs.sub.2 is the most promising active switching material having the parameters, and a method of making thin films of a-CdAs.sub.2 by open source evaporation is disclosed.