Rca Inc.

Sarnoff Corporation

US Government As Represented by the Secretary of the Army

Arthur Herbert Firester

Istvan Gorog

Dennis John Bechis

Bawa Singh

George Herbert Needham Riddle

Karl G Hernqvist

Michael T Gale

Thomas L Credelle

Joseph Thomas McGinn

Michael Gillis Kane

Herschel Clement Burstyn

Joseph Michael Carpinelli

John P Russell

Robert V D'Aiello

Donald Barry Carlin

Ping Sheng

Gong Gu

Macy E Heller

Joseph Paul Walentine

A read-only memory (ROM) is disclosed that uses the presence or absence of linear passive electrical elements, such as resistors or capacitors, to encode zeros and ones, permitting a large-area ROM to be fabricated, possibly on a flexible substrate. The ROM includes a substrate, a plurality of row conductors insulated from each other and at least partially layered on a portion of the substrate; a plurality of column conductors insulated from each other and from the row conductors and at least partially layered above or below a portion of the plurality of row conductors, a plurality of amplifiers electrically connected to the column conductors, and at least one linear passive element attached between the row conductors and the column conductors. An amplifier connected to a column conductor has an input impedance much lower than the combined parallel impedance of the linear passive elements connected to that column, thus comprising a virtual ground, and is operable to output a first logical state when one of the linear passive elements is electrically connected between one of the row conductors and one of the column conductors, and operable to output a second local state when said one of the linear passive elements is absent between one of the row conductors and one of the column conductors. The resistive or capacitive arrays can be made into low-cost imagers if the resistors/capacitors are sensitive to electromagnetic radiation or mechanical pressure.

Read-only memory using linear passive elements

A plural-beam cathode ray tube includes an electron gun directing electrons towards a faceplate having an electrode biased at screen potential. The electron beam is magnetically deflected to scan across the faceplate to impinge upon a pattern of phosphors thereon to produce light of different colors depicting an image. A first conductive coating near the tube neck is biased below screen potential and a second conductive coating between the neck electrode and the faceplate is biased at screen potential. A gap between the first and second conductive coatings varies in distance from the faceplate so as to be non-Z-planar. The non-Z-planar gap is preferably partly within the region wherein electrons are deflected by the magnetic deflection yoke and partly more proximate the faceplate than such deflection region.

Bi-potential electrode space-saving cathode ray tube

Large visual displays are comprised of an array of smaller display devices or modules, each of which displays a portion of the image to be displayed so that together the array of smaller display devices displays the complete image. Unlike conventional large displays which necessarily seek to minimize the edge areas of the smaller display elements that do not display an image so as to minimize the &ldquo;seams&rdquo; or gaps between the image portions, the present display device projects image portions scanned from less than the entire display area of the smaller display devices in an array to create an image on a substantially flat panel that is substantially free of visual &ldquo;seams&rdquo; or gaps between the image portions. Thus the display device may employ display elements that do not have narrow edges and that are not contiguous to generate overlapping sub-images. Image pixels in what would otherwise be &ldquo;seams&rdquo; or gaps are generated from the image data and are displayed in proper position and brightness in the displayed image, such as in the overlap regions of overlapping sub-images. Where the scanning beams are electron beams, the flat panel is a faceplate that includes phosphors that are excited by the electron beam to produce light, and where the beams are light beams, the flat panel is a distributor of light, such as a diffuser panel.

Modular display system

An LCD pixel in accordance with the invention has disposed on a substrate a segmented back-to-back diode, an address line, and an electrode adjacent to the address line. The electrode has an additional portion, with one diode segment disposed on the additional portion and the other diode segment disposed on the address line. A free area of the substrate is adjacent to the additional portion so that the diode area is accurately defined.

LCD pixel incorporating segmented back-to-back diode

The performance of a photodetector is reduced by the presence of an electrical defect such as a short or a shunt. The invention is a method of improving the performance of this photodetector by preferentially removing a portion of an exposed surface of a detector electrode at the defect site. The preferential etching of the exposed surface is obtained by immersing the photodetector in a chemical etching ambient which has an etching rate for the exposed surface of the electrode which increases with increasing temperature while applying a reverse-bias voltage to the electrodes. The reverse-bias voltage has sufficient magnitude to cause a local increase in temperature of the exposed surface at the defect site.

Method for eliminating defects in a photodetector

A method of producing an information storage disc by optical techniques includes the steps of coating a flat, reflective disc surface with a thin coating of radiant energy sensitive material, moving the coated disc relative to a coherent light beam, which is intensity modulated with the information to be recorded, to expose the radiant energy sensitive material, and developing the radiant energy sensitive material to form a track having geometric variations in the disc representative of the modulated information signals.

Optical recording in thin photoresist

The beam intensity of an optical recording system employed for recording frequency modulated composite video signals on discs undergoes temporal distortion at critical signal frequencies in a manner complementary to the effects of frequency distortion in the spatial frequency response of the recording system. Concomitant recording of the composite signal and a groove effects a practical elimination of signal track drop which results when recording is effected on pre-grooves discs, and additionally eliminates frequency response distortions in the recorded signal due to the optical recording system.

Optical recording with track drop compensation

Recovery from a record of information recorded in an elongated information track comprising depressed areas alternating along the length of the track with relatively non-depressed areas, is effected by an optical playback system. The playback system employs means for illuminating a focusing lens with a light beam having a cross-section forming a closed band of light, such as an annulus, to thereby increase the depth-of-field of the resulting focused spot formed on the information track. Light detection means, responsive to light diffracted by the track provides an output signal representative of the recorded data.

Optical playback system having increased depth-of-field

The light power not occluded during a repetitive, transverse knife-edge scanning of a focused spot is measured by a photodetector while an interferometer measures the displacement of the knife-edge during the scanning operation. The knife-edge is supported on a glass plate carried by the photodetector with a liquid medium being located between the glass plate and the light sensitive surface of the photodetector to enhance light reception by the photodetector. The differentiated output of the photodetector when displayed (e.g., by means of an oscilloscope) provides a graphic representation of the intensity profile of the spot which is dependent on the composite refractive index of the glass plate and the liquid medium. The output of the interferometer when displayed along with the intensity profile of the spot provides a known quantity with reference to which spot diameter as a function of the composite refractive index can be accurately determined to within 1/8 of a wavelength of the light provided for the measurements of the interferometer.

Apparatus for the determination of focused spot size and structure

High speed writing apparatus, for mapping 1:1 polar plots of disc record defect locations on disc-shaped electrosensitive paper, accepts electrical signals representing defect occurrences from a defect detector which scans the disc record surface in a spiral scanning pattern. These signals activate a high voltage switch circuit that produces an electric current between an electric writing pen stylus and a conducting surface of a turntable of the printing apparatus upon which the disc shaped electrosensitive paper is mounted. Relative motion is established between the turntable and the writing pen in a manner causing markings resulting from pen activations to be located on the electrosensitive paper with radial and circumferential positions corresponding to the locations of the defects appearing on the disc record, thereby generating 1:1 polar plots of the defect locations on the paper. The writing pen scans the paper disc surface in a spiral scanning pattern in synchronization with the defect detector scanning of the disc record. The writing pen is a multistylus pen used in a balanced configuration to effect high speed marking of defect locations without causing damage to the paper.

Defect plotting system

System employs pinhole array in conjunctionwith a random phase shift plate for recording a redundant Fourier-transform hologram of a two-dimensional object that exhibits a gray scale.

System for recording redundant fourier-transform hologram

Defect detection apparatus, for optically inspecting a spiral groove of a video disc record, directs a coherent light beam at the grooved surface of the disc. The incident beam, focused at a point beyond the disc surface, illuminates the grooved surface with a light spot that spans a plurality of convolutions of the groove. Relative motion is established between the disc surface and the incident beam in a manner causing the illuminating spot to rapidly scan the groove surfaces in a coarse spiral pattern. The structure of the illuminated groove convolutions, absent any defects, serves as a diffraction grating for diffracting the light into an undeviated zero diffraction order cone of light that converges at a first location in a plane spaced from the disc surface and into deviated higher diffraction order cones of light that converge at additional locations in said plane separated from the first location. A photodetector is positioned to be in registry with the first location and spaced from said additional locations. A blocking means is placed over a central region of the photodetector to normally intercept the zero diffraction order light, thereby preventing the conversion of light energy to electric energy by the photodetector when defect-free groove regions are illuminated. When a defect exists in the illuminated region of the groove, unblocked regions of the photodetector receive light and the photodetector produces electrical signals indicative of the presence of a defect. A servo means, responsive to departures of the zero order cone axis from a desired orientation, is employed for controlling the orientation of the axis of the incident beam to oppose such departures, in order to preclude false defect indications due to warpage or unevenness of the disc record.

Defect detection system

Two ring mounts extend around and are secured to a gas laser discharge tube. The ring mounts are positioned near opposite ends of the laser tube. The laser discharge tube is in a prealigned relationship to the external perimeter of each ring mount. The mounts serve as the means for mounting the laser discharge tube. The mounts are formed by placing the laser discharge tube within two molds and aligning the laser output beam with respect to the molds. Plastic material is then forced into the molds and allowed to harden so as to permanently fix the aligned relationship of the tube with respect to the mold.

Prealigned laser mount and method of making same

A mirror is aligned on a laser tube using an apparatus comprising a window spaced from the mirror and a means for containing fluid, such as a bellows, between the window and the mirror. The window and the fluid have an index of refraction that matches that of the mirror. The bellows permits the mirror's relation to the window to be changed without the loss of the fluid. In aligning the lasing mirror, the window is oriented normal to a light beam from an autocollimator. The mirror is then placed in contact with the laser tube and oriented so that the beam from the autocollimator is reflected back on itself.

Laser alignment apparatus and method with an alignment mirror

An optical element for a laser, such as a mirror, includes a rectangular parallelepiped body of a material suitable for the element, such as glass, and a cylindrical projection extending from one surface of the body. The projection is smaller in area than the area of the surface of the body and the periphery of the projection is spaced from the edges of the surface. The edge of the surface of the projection is free of nicks or chips and serves as the mounting edge for the element in a laser. A plurality of the elements are made simultaneously by etching the surface of a sheet of material to form a plurality of spaced projections and dividing the sheet along lines between the projections. Prior to dividing the sheet, the surfaces of the projections may be coated with a suitable optical coating.

Growing community of inventors

Skillman, NJ, United States of America

Arthur Herbert Firester