Abstract: A light detector circuit is described in which the baseline level of the output signal of a light detector is stabilized by feeding back a control signal to an element that has a voltage variable resistance and is connected in series with the light detector across a voltage source. Several embodiments are shown. In one embodiment a differential amplifier circuit with an integrating feedback circuit is employed to establish a stabilized control voltage.

Abstract: A laser beam scanner with encoder and a laser beam plotter with encoder are disclosed. The scanner provides for unsharp masking by alternating between a large scan beam and a small scan beam on alternate scans. Compensation for non-straight scan lines is achieved through a small linear galvonometer placed in the scanning optics. An equal conjugate optical system is utilized to allow encoder information to be obtained from a stationary image of the main scanning and plotting galvonometer mirror.

Abstract: An apparatus for reading an original surface by illuminating it with a slit-like light beam includes a fixed linear light source, a cylindrical parabolic mirror fixedly provided so that the focal line position thereof is coincident with the linear light source, the light beam from the linear light source being directed in a predetermined direction by the parabolic mirror, a cylindrical scanning mirror disposed so that the generating line direction thereof is coincident with the generating line direction of the cylindrical parabolic mirror, the cylindrical scanning mirror condensing the light beam from the cylindrical parabolic mirror in a slit-like form on the original surface and being moved along the original surface to thereby illuminate the entire area of the original surface, and an optical system movable with the cylindrical scanning mirror to read the light beam scattered by the original surface, the optical system includes a line sensor array and optical means for directing the scattered light to the

Abstract: An optical shaft angle encoder uses novel slit emitters having a long, narrow, configuration coupled with collimation lenses to utilize emitted light beams having an improved degree of collimation in an axis perpendicular to radial axes of a rotating code wheel and, thereby, to provide a higher quality generated electrical waveform which is used to describe shaft rotation. The slit emitters are narrowed to improve collimation uniaxially and lengthened to increase the total power of the emitted light.

Abstract: An improved optical system for thermal imaging systems using wide field of view optics in conjunction with large detector arrays in which a detector cold shield, system aperture stop and scanning subassembly are placed in substantially the same location such that the size of the scanning optics is minimized and cold shielding efficiency is maximized.

Abstract: A tracking servo signal generating device in a tracking servo control system in a recorded information reading apparatus adapted to deviate an information detecting point in the direction perpendicular to a target recording track on a recording medium in accordance with the tracking servo signal so that the information detecting point accurately traces the recording track, which comprises detecting means for producing a pair of detection signals a difference between which represents amount and/or direction of deviations of the information detecting point from the recording track in the direction perpendicular to the track. The pair of detection signals is processed to produce a first difference between low frequency components of the detection signals and a second difference between envelope components of high frequency components of the detection signals.

Abstract: Logic circuits employ photoresponsive GaAs field effect transistors to directly drive GaAs laser diodes to provide optical output signals in response to optical input signals. Since the only electrical inputs are DC bias voltages, each such circuit can be readily decoupled, such as for use in electrically noisy environments. The optical output represents a predetermined logic condition in response to a predetermined operating current applied to the laser diode as a result of the operation of the photoresponsive device. Two photoresponsive devices may be used to apply two different operating current magnitudes to the laser diode to produce two different optical output signals.

Abstract: A semiconductor printing apparatus eliminates the alignment error caused by any relative deformation between the mask and the wafer due to variations in parameters such as temperature change, and intermediate processing, for example, etching etc. The apparatus is characterized by the provision of a device for cooling or heating respectively and independently plural different sections of at least either of the mask and the wafer.

Abstract: A beamformer device for forming at least one beam from the outputs of a sensor array, including: a plurality of radiation sources; means for providing to each radiation source a signal from an associated one of the sensors in the sensor array; a detector array of radiation-sensitive means for providing a series of spaced signals representing radiation incident from each of the radiation sources; and means for varying the delays between the spaced signals for optimizing the response of the device to a signal from a predetermined direction.

Abstract: A differential pressure sensor has a sensing diaphragm mounted in a body. The curvature of the diaphragm is representative of differential pressure across the diaphragm. Monochromatic light is direct from a source at the diaphragm to set up interference fringes which have varying spacings representative of the curvature, in the manner of Newton's rings. The fringes and their spacings are monitored and a computer calculates therefrom the curvature of the diaphragm and thence the pressure difference.

Abstract: A concentricity evaluating system has a stage supported by a hydrostatic bearing in at least one of radial and thrust directions. The angle of rotation of the stage is detected by a rotation angle detector. On the stage a hollow cylindrical member is fixed coaxially. Onto the upper end face of the hollow cylindrical member or into the hole thereof a light beam is applied from a light emitting means, whereby a clear image of the profile of the hole is formed. The image thus formed is enlarged by an optical system. The light beam passing through the optical system reaches a photodiode array which is positioned across a part of the enlarged image. The hollow cylindrical member is rotated, and a displacement meter is detected how the circumference of the hollow cylindrical member varies as the member rotates. Data from the displacement meter, photodiode array and the rotation angle detector are fed to an interface and processed.

Abstract: A photomultiplier detector protection system and method utilizing a negative feedback loop to maintain the photomultiplier detector output below a predetermined output. The feedback loop comprises a comparator responsive to the photomultiplier detector output and also responsive to a predetermined limit signal. The comparator output is applied to a summing amplifier which also receives a voltage adjust signal. The output of the summing amplifier controls the output of a power supply which is in turn applied to the photomultiplier detector.

Abstract: An apparatus is disclosed which inspects whether or not an object to be inspected contains an abnormality, defect or the like by using a single photo-sensor such as a video camera provided with a photo-electric conversion screen such as a target screen therein. An inspection section or processor such as an computer is provided to receive the output from the video camera and process the same to determine whether the object contains the abnormality, defect etc. or not. The video camera includes an optical lens arrangement which can simultaneously focus images of at least two different portions of the object on the target screen of the video camera.

Abstract: In an automatic brightness control feedback loop for controlling the bias voltage of a microchannel plate of an image intensifier tube, there are provided a gas discharge tube and a photoconductor which is photoelectrically coupled with the gas discharge tube. The brightness of the gas discharge tube is controlled depending on the phosphor screen current. An ordinary automatic brightness control and also the blinking when the incident light is excessive can be made by having the bias voltage of the microchannel plate depend on the resistance of the photoconductor.

Abstract: An angular-position encoder has a transparent scale (106) which is rotatably supported between an illumination device (109) secured to the housing and a photoelectric receiver. A self-scanning photodiode array (102) which has an annular photosensitive region (103) is used as the receiver. The otherwise uniform incremental graduation (108) of the scale (102) which is projected onto the array is interrupted at one point by a code field (111) which covers a few diodes of the array. Eased on the numbers of the diodes onto which the code field (111) is projected, the position of the scale (106) is determined as an absolute quantity by a "rough" read-out electronic system, while a "fine" reading (added to the "rough" determination) is effected by an interpolation based on the signal intensities of the other diodes covered by the incremental graduation (108).

Abstract: The photodetector comprises a silicon substrate with high sensitivity, a diffusion layer defining a PN junction, and a CdTe layer, as filter, placed on the face close to the PN junction, for stopping radiations of wave lengths shorter than 0.8 .mu.m. The photodetector is suitable for detecting radiations of AsGa diodes used in optical telecommunication systems.

Abstract: An apparatus for detecting and measuring the area of defects in a sheet or rolled material comprises a defect detection section which rapidly scans the whole area of the material to locate the positions of defects and a defect size measuring section which is moved directly to each of the located positions to measure the area of the defect.

Abstract: The circuitry required to obtain a ing that of the quadrature pair, the bits of a multibit binary word are gated with a coarse index taken from the code disc. The multibit binary word includes square waves already available in the multiplier and an additional bit obtained from a logical combination of the pair of quadrature signals.

Abstract: An optical fiber position sensor includes an optical fiber cable wound in the shape of a single layer, tightly wound coil, the coil being secured to a first member. A second member, which is linearly movable with respect to the first member, has fixed thereto an LED which is aimed at the coil such that radiation being emitted from the LED is injected approximately tangentially into the coil. Radiation being transmitted through the coil is attenuated as a function of the distance that it travels therethrough and as a result, radiation exiting the coil through the terminations is representative of the location of the movable member with respect to the fixed member.

Abstract: A moving object detecting apparatus of which a plurality of light receiving means arranged to have a common light receiving zone and a plurality of independent light receiving zones are disposed within a single casing together with a light emitting means. Receiving order in the respective light receiving means of reflected light from a moving object within the zones is detected to discriminate moving direction of the object and desired indications are performed responsive to the discriminated direction.