Abstract: An imaging system employs a photoconductive material capable of bearing a latent photostatic image, a plurality of elongated parallel stripes adjacent the photoconductive material, selective scanning of the stripes to produce charge carriers within the photoconductive material, and time-ordered detection of the current created by the charge carriers with the plurality of elongated parallel stripes. Appropriate addressing of the stripes as they are scanned produces a pixellated representation of the latent image. The system has improved output signal strength and higher resolution than known systems.

Abstract: In a pen plotter having plotting media supplied in the form of plotting media supply rolled around a hollow tube, this is a method and apparatus for automatically identifying the type of, and measuring the amount of, plotting media contained on the plotting media supply roll. A circular barcode strip is secured to the inner surface of the supply tube and is optically scanned to reveal the identity of the media contained on the supply roll. Said barcode strip's properties allow for the determination of the rotational velocity of the supply roll which, when used in conjunction with other known and easily derivable pieces of information, also allow for the precise calculation of the amount of media remaining on the roll. Knowing the identity of the media on the roll allows the plotter to handle the media in a manner consistent with its properties. Knowing the quantity of media remaining allows both media low and media out conditions to be determined and alarmed.

Abstract: A device for detecting the marker dye band which is used to monitor the progression of biological macromolecules in gel electrophoresis. This device mounts external to the gel box, and utilizes a single light detector and a pair of AC activated light sources. The light sources produce reflected or transmitted light signals which, when balanced at the detector, cancel. When marker dye is absent the light signals are balanced, and no signal is detected. When marker dye is present at a specific detection point within the gel, the light reflected (or transmitted) is no longer balanced and a signal is detected.

Abstract: An optical element drive apparatus includes an objective lens for applying a light beam spot to a recording surface of an optical disc and a holder for holding the objective lens. The objective lens is supported to be movable in the focusing direction and the tracking direction by a carriage through the holder. The objective lens is moved by first drive mechanism including focusing and tracking coils and a magnetic circuit magnetically acting on the coils. The magnetic circuit is partly constituted by the carriage. The carriage is supported by a support mechanism and moved in the tracking direction by second drive mechanism.

Abstract: A microlithographic stepper, employing a Half-Field Dyson projection optical system, achieves focusing of an image of a first-layer reticle pattern on a completely unpatterned reflective wafer surface by including a repetitive diffraction pattern on the reticle which has a configuration in which a particular ordinal diffraction order is normally missing. In response to being simultaneously illuminated with each of two incident monochromatic beams of light, diffraction orders generated by the repetitive diffraction pattern are imaged on the reflective wafer surface and then reflected back to and reimaged on the repetitive diffraction pattern on the reticle. Diffraction orders generated on the first encounter with the repetitive diffraction pattern generate light in the originally missing ordinal diffraction order on the second encounter.

Abstract: The sensor has at least one sensor unit arranged opposite an incremental measurement scale (1) with reflecting graduation (2). The sensor unit comprises a photoemitter (3) and an adjacent photoreceiver (4), located in a printed circuit (6), with optical axes (xx') parallel to each other and perpendicular to the plane of the scale (1), and an optical group (9) with two focusing lenses (10, 12) and two deflection faces (11, 13) integrated by molding in a support of transparent synthetic material. In the optical group, one of the two lenses and one of the two deflection faces are aligned on each of the two said optical axes (x, x') in order to direct and deviate the light rays coming from the photoemitter (3) and to recover them on the photoreceiver (4) after their passage through a graduated sensing graticule (14).

Abstract: A device for position encoding of a rotating shaft in which a polygonal mirror having a number of facets is mounted to the shaft and a monochromatic light beam is directed towards the facets. The facets of the polygonal mirror each have a low line density diffraction grating to diffract the monochromatic light beam into a number of diffracted light beams such that a number of light spots are created on a linear array detector. An analog-to-digital converter is connected to the linear array detector for reading the position of the spots on the linear array detector means. A microprocessor with memory is connected to the analog-to-digital converter to hold and manipulate the data provided by the analog-to-digital converter on the position of the spots and to compute the position of the shaft based upon the data from the analog-to-digital converter.

Abstract: In a circuit arrangement for the operation of a light source for the optical scanning of recording media, in particular so-called compact discs, from an information signal obtained by the scanning a signal (quality signal) is derived which describes the quality of the information signal. The power of the light source is controlled in dependence on the quality signal with the aim of maximising quality.

Abstract: A plurality of CCD sensors are arranged whose respective light receiving portions form a line sensor of a single straight line on a plurality of ceramic substrates. The plurality of ceramic substrates are arranged on the frame such that one end portions of respective elastic elements are in contact with the longitudinally opposed side edges of the ceramic substrates, and the other end portions are fixedly mounted on the frame. When the frame expands or contracts due to a change in circumferential temperature so that displacement in the longitudinal direction occurs, the one end portions of the elastic elements slide on the edge parts of the ceramic substrates. That is, deformation in the longitudinal direction of the frame is not transmitted directly to the ceramic substrates. Thus, it is possible to prevent space or interval slippage on a straight line from occurring between the plurality of CCD sensors.

Abstract: A four-layer, wideband anti-reflection coating (30) is formed on a light-receiving surface (22) of an indium antimonide (InSb) photodetector (10) to enable detection of light at visible as well as infrared wavelengths. The layers (30a,30b,30c,30d) each have an optical thickness of approximately one-quarter wavelength at a reference wavelength of 1.6 microns. The refractive indices of the layers (30a,30b,30c,30d) are stepped down from the surface (22), having values of approximately 3.2/2.6/1.9/1.45 respectively. The second layer (30b) is preferably formed of silicon suboxide (SiO.sub.0<X<1) by electron-beam deposition of silicon in an oxygen backfill to obtain a refractive index between the indices of silicon and silicon monoxide. A thin passivation layer (26) of germanium or silicon nitride is formed on the surface (22) under the anti-reflection coating (30) to inhibit a flashing effect at infrared wavelengths after exposing to the ultraviolet (UV) and/or visible light.

Abstract: A proximity sensor apparatus for use with a laser diode device utilizes the photodiode mounted in the housing of the laser diode, and includes an electronic circuit coupled to the photodiode to monitor the output of the photodiode. When an object is closely adjacent to the output window of the laser diode, reflected light from the laser diode is transmitted retrograde through the output window and is received by the photodiode within the housing. The circuit of the invention establishes a threshold level for the photodiode current, determines the proximity of the reflecting object and permits (or prevents) operation of the laser diode. The circuit also includes a sampling timer to operate the laser diode for a very brief period (on the order of microseconds) each second, to ascertain if a target object is proximate to the laser diode output. The circuit is set to prevent laser operation, and operates the laser diode to emit a brief test pulse and determine the level of reflected laser light.

Abstract: A disk cartridge has a disk accommodated in a casing having a center aperture and access windows. A pivotal shutter is pivotally mounted for closing the center aperture. A rotary shutter is rotatably mounted for closing the access windows and interlocked with the pivotal shutter. A first slidable member is cooperatively coupled to the rotary shutter, and a second slidable member is opposed to the first slidable member and adapted to be slid upon engagement with a shutter actuating member when a disk drive is loaded with the disk cartridge. The first and second slidable members having racks on their opposed surfaces interlocked through a gear mechanism for transmitting the motion of the second slidable member to the first slidable member, which in turn, drives the rotary shutter.

Abstract: A method of detecting image information which enables real-time extraction of mobile components of optical input image information in the form of electric current signals or real-time extraction of outlines of optical input image information in the form of electric current signals. The method uses a photoelectric device having a photoreception plane carrying arrays of pixels of a photosensitive material capable of directly converting an optical input signal into an electric current signal. The photosensitive material is endowed in itself with a differential responsivity which changes the level of the materials's output electric current in accordance with the rate of change in the incident light intensity of the optical input signal per unit time, so that only mobile components of the input image information are selectively and automatically detected in real time in the form of electric signals.

Abstract: An endpoint detector for gas purifiers which contains a detection element comprising a small amount of a highly reactive metal coated on an insulator and exposed to the gas stream being purified. This metal does not react with the gas being purified, but does undergo reaction with the impurity species. As this metal reacts with impurities in the gas stream, its conductivity decreases. The change in conductivity signals that the wave front of impurity-containing gas has reached the sensor, and thus the purifier has reached the end of its useful life. The use of a thin coating of reactive metal as the detection element gives the sensitivity that is required to sense sub-part-per-million levels of impurities. This resistance change sensor may be combined with a thermal measurement to detect the presence of exothermic conditions indicative of a large pulse of impurity gas.

Abstract: A portable laser pulse detection device. Optical pulses are sensed by a photodiode, and if the pulse width is narrow enough to yield sufficient spectral energy within the bandpass of the tuned circuits, a "laser occurred" indication will be produced by the processing circuitry. Automatic adjustment of the detected output for non-laser incident radiation is made by varying the signal level into a sequential detection logarithmic amplifier by a voltage proportional to the integral of the incident radiation over a short period of time. The device is shielded against electromagnetic interference and adapts automatically to variations in background noise.

Abstract: An optical distribution system incorporating improved absorbance-based optical fiber sensor incorporating fiber optic couplers, thereby eliminating fiber optic connectors in the system to provide improved efficiency and improved output in the system, the system further incorporating specific thermal stabilizing mechanisms to improve the stability of the system and a specific construction for the photodiode assembly to minimize internal reflection therein.

Abstract: Information is received from an image on a moving substrate. Flash exposure is used, defining operating or exposure cycles. The reflection or a representation of the image is subdivided into a matrix having n columns and m rows or lines. The sensor is a charge coupled device (CCD), arranged to have a sensing area (11) with n columns and m rows or lines, and a storage region or section (12), likewise arranged to have storage cells of n and m columns and rows or lines. Information of any one image element, upon sensing, is shifted by a line transfer pulse by one image line. The line transfer pulses are synchronized with web movement of the substrate and operate as shift pulses. The m line, at the first transfer line shift pulse, is shifted into the first line or row of the matrix of the storage portion of the CCD. For each operating cycle, at least one line transfer pulse is used. The information of the image elements can be read out serially from the storage portion (12) at high speed.

Abstract: A reader for a coded discontinuous security thread in a security document comprises a multiplicity of reading channels each coupled to at least one magnetic transducing means (11, 40) for sensing along a track across the document and including processing circuits for forming a channel signal which exhibits signal excursions in response to the passage of the ends of each length of magnetic material. First and second comparators (55, 56) compare the channel signal with relatively positive and relatively negative thresholds respectively and a bistable switching means (59) is coupled to the comparators to provide a digital signal. A reference comparator (64) controls an analog switch and diode pumps (70, 71) to adjust the thresholds in accordance with the amplitude of a signal excursion.

Abstract: In an automatic focusing system an element (2) is inserted in the path of a beam of light (3) directed towards a sensor array. The element comprises a transparent material or predetermined reflective index, the element presenting a first region (4) of a first thickness and another region (5) of a greater thickness. The image falling on to the sensor comprises three areas--one area where the light has passed through the one region and another area where the light has passed through the further region and yet another area. The automatic focusing system derives signals from two of the areas and processes the signals so that the image is in focus in the third area.

Abstract: A flitch or cant is successively transported by a pair of differentially operated clamps, first to a scanning station, and then to a sawing station where the wane is removed. A series of flitches are processed in this manner such that as the wane edge from a first flitch is sawn, a next flitch in succession is optically scanned. The sawing and scanning is accomplished by means of a combination saw and scanner which moves in a direction longitudinal of the flitch as respective flitches are held in stationary positions at the sawing station and at the scanning station. Between passes of the saw-scanner combination, the sawn flitch is conveyed away and the next flitch in line is conveyed forwardly to the sawing position while being skewed by the clamps in accordance with the characterization generated by the scanner.