Abstract: An optical disk apparatus includes a semiconductor laser for emitting a light beam, and an automatic power control or APC circuit for driving the laser. A compound prism structure is optically coupled to the laser in an optical head section, and defines a first optical path for causing a front laser light to be projected onto a rotating optical disk and guiding a reflected light therefrom toward a first photodetector, and a second optical path for guiding a part of the reflected light toward a second photodetector. An output signal of the first photodetector is used to generate a reproduced information signal. An output signal of the second photodetector is fed back to the APC circuit as a front light monitor signal. A part of a laser control signal internally generated in the APC circuit is supplied through a wiring line to a noise reduction circuit as a laser noise monitor signal.

Abstract: A print paper detecting circuit for installation on a printer, to detect whether a print paper is supplied at a predetermined position along a paper path by using an optical sensor composed of a light emitting diode and phototransistor. The circuit detects the existence of the print paper according to the detection of light which is emitted from the light emitting diode, which is reflected from the print paper, and which arrives at the phototransistor. According to one embodiment, circuit has a current amplifier and a gain reducing circuit. The current amplifier feeds a pulse current which is greater than the normal constant current to the light emitting diode while the gain reducing circuit reduces the output of the output voltage.

Abstract: An apparatus and a method for measuring the radius of curvature of a surface using a laser beam with a wavelength selectable from a plurality wavelengths are disclosed. The present invention avoids poor measurement due to destructive interference of the beams reflected at a thin film's upper and lower surfaces. The present invention is applicable to laser reflection stress measurement apparatuses of both scanning and beam-splitting types.

Abstract: A image intensifier tube, having its brightness curve corrected in a simple way. The image intensifier tube comprises an input window (3), and an output window (4) at which the brightness is measured. The output window (4) bears a device for the attenuation of light (20), the opacity of this device being greater in a central zone (0) than it is towards the edges (21).

Abstract: A confocal imaging system utilizes an opaque mask with a slit and a row of pinpoint sensors or utilizes an opaque mask with a skewed pattern of pinholes and an array of isolated pinpoint sensors in a matching pattern in order to obtain sufficient data to provide a complete image for imaging and/or inspecting an object such as electronics in a single one-dimensional scan. The system also simultaneously produces multiple images at different heights in the single one-dimensional scan of the viewed object, and also simultaneously produces images taken in different spectral bands in the same one-dimensional scan of the object to be imaged and/or inspected. The relative height or depth of the different images can be modified by simply adjusting the inclination between the confocal imaging system and a path followed by the object that is to be imaged and/or inspected during the one-dimensional scan.

Abstract: A converging funnel is placed in an exhaust line to direct substantially all the gas flow in the exhaust line to the sensing laser beam of a particle sensor, thereby preventing deposition of species carried by the gas from depositing on the particle sensor. By concentrating substantially all gas flow through the laser beam, the particle count rate is increased because substantially all particles carried by the exhaust gas is channeled through the laser beam. Further, the particle sensor is also prevented from adverse heating effects of the exhaust gas. In one embodiment, the converging funnel is mounted to the interior wall of the exhaust line by a centering ring.

Abstract: An apparatus and method for automatically testing a safety light curtain used to protect to an unsafe moving part of an industrial machine. A combined beam splitter and photodetector is temporarily attached to the receiver of the light curtain with beam splitter in the path of one of the light beams. A portion of the light beam continues to a receiver of the light curtain and a diverted portion of the light beam illuminates a photodetector. Interruption of this particular light beam simultaneously triggers a safety system to initiate the stopping of the machine and triggers the photodetector. A motion detector temporarily coupled to a rotating part of the machine determines when the machine has stopped. This motion detector may include a d.c. tachometer coupled via a resilient friction wheel. A timer connected to the photodetector and the motion detector determines the duration of the interval between interruption of the one light beam and the stopping of the machine.

Abstract: Beam position sensors detect deviations of a light beam from target positions defined at both sides of a recording drum. Predicted total deviations of light beam from the target positions are calculated as a function of beam position signals detected by the beam position sensors. A piezoelectric element of a sub-deflector is actuated in response to the predicted total deviations. The light beam deflected by a main deflector scans the target positions on a recording medium.

Abstract: An apparatus for preventing blocking of a measuring head intended for carrying out measurements on substances suspended in a flowing medium. A light beam is transmitted from a radiation source with a determined intensity which is essentially constant during the measuring process. the intensity of the radiation radiated from the medium is indicated with the aid of at least one radiation indicator. The electrical output signal of the radiation indicator is sent for evaluation to a signal processing device. An open measuring channel has two mutually opposing edges which are intended to be placed along the direction of medium flow. Radiation from the radiation source is emitted from the one edge and received at the other. Placed in connection with the measuring channel are radiation-conducting elements which are placed as close as possible to the outer part of the edges. All of the junctions between surfaces of different extension in the vicinity of the measuring channel are gently rounded.

Abstract: A laser warning device for sector-by-sector surveillance of the air space, comprises a plurality of module sections such that each surveyed sector is coupled through an optical antenna and an optical buffer to a module section.

Abstract: A solid-state image sensor of a CCD is disclosed, wherein the photodiodes in the photo-sensing part are arranged in regions separated horizontally. A vertical CCD channel is interposed between the photodiodes so that high resolution is achieved by increasing the horizontal resolution without any change of the driving pulse frequency or the charge handling capability.

Abstract: A CCD camera is set under a print object having a registration hole, and a screen plate having a reference mark on its screen corresponding to the registration hole is arranged above the position of the print object. First, the amount of elongation of the screen is measured from a position of the reference mark in an unelongated state of the screen and that of the reference mark in a elongated state of the screen upon operation of a squeegee, and the shift amount between the registration hole and the reference mark is calculated from positions of the reference mark and the registration hole before printing This shift amount is corrected by the amount of elongation of the screen, and the screen plate is moved in response to the corrected shift amount to attain registration.

Abstract: A radiation transmission fiber for spectroscopic monitoring includes a transmission portion and a sensor portion; the transmission and sensor portions have a continuous core portion and continuous cladding over the core portion throughout the transmission and sensor portions; the sensor portion of the core is of smaller diameter than the transmission portion(s) and is connected to the transmission portion(s) by a conical transition portion(s); and the cladding in the transmission portion is of greater thickness than the cladding in the sensor region.

Abstract: A photographing apparatus for microscopes is constructed so that a simultaneous observation is made by overlapping an image of a sample formed by transmitted illumination with that formed by reflected fluorescence, in which signals for designating the simultaneous observation at once cause a second shutter for the transmitted illumination to be closed and a first shutter for the reflected fluorescence to be opened, the brightness of the sample image formed by the reflected fluorescence is measured by a light-detecting element disposed in an optical path for observation, and after a light-adjusting member for the transmitted illumination is controlled so that, based on data outputted from a memory device corresponding to a measured value, the brightness of the sample image by the transmitted illumination in the simultaneous observation is balanced with that of the sample image by the reflected fluorescence, the second shutter is opened.

Abstract: A rotary color scanner has both linear and logarithmic mode static and dynamic calibration to quickly and automatically calibrate the scanner before each scan, as well as during a given scan, without operator intervention of any kind, whether in the factory or in the field. Close calibration is achieved, despite the use of photomultiplier detectors which are inherently particularly susceptible to drift, and despite the use of high intensity lamps whose output typically varies greatly with aging. The system establishes operation at an optimized data throughput rate up to a limit determined by the maximum scan rate of the system, and thereafter switches to operation at an optimized signal/noise ratio.

Abstract: An evanescent wave liquid level sensor for measuring the density-compensated level of a liquid in a container. The sensor employs an eccentric core optical fiber fully immersed in the liquid to be measured. Light is injected into one end of the fiber. Some of the light will be lost due to evanescent wave losses. Changes in the ratio of the intensity of the input light and the reflected light are due solely to changes in the density of the liquid. Changes in the liquid density can then be used to compensate a liquid level measurement. Since the liquid temperature is related to its density, the sensor can also be used to measure changes in the liquid temperature.

Abstract: A light beam transmitter and receiver are located in or near a door opener enclosure, and fiber optics connect the transmitter and receiver to the sides of the door opening. Lens arrangements are attached to the ends of the optic cables and are mounted near the bottom of the door frame. Thus, the transmitter and receiver do not need to be located near the door which eliminates the need for wiring from the enclosure to the door area and protects the transmitter and detector from physical abuse at the doorway.

Abstract: An optoelectronic system for controlling laser drive current to produce a power level at the target independent of changes in the transmissivity of a beamsplitter positioned in the optical path between the laser source and the target. A second beamsplitter with transmissivity and reflectivity factors matched to the first beamsplitter is used to direct portions of light to two photodetectors. The two photodetectors are connected to circuits which produce a signal proportional to the power transmitted by the first beamsplitter divided by the power reflected by the second beamsplitter, that quotient multiplied by the sum of the photodetector signals to produce a final detection signal which is used as input to the servo control of laser drive current.

Abstract: A radiation image read-out apparatus comprises a read-out section for photoelectrically reading out a radiation image from silver halide film, on which the radiation image has been recorded, and thereby generating an image signal representing the radiation image. A signal conversion device converts the image signal such that distortion in the image signal, which distortion is caused to occur by nonlinear characteristics of the silver halide film, may be eliminated. A corrected image signal is thereby obtained, which can be processed commonly with an image signal obtained by reading out a radiation image from a stimulable phosphor sheet, on which the radiation image has been stored.

Abstract: A color preserving image intensifier having synchronously reciprocating input and output multi-segmented, multi-color filter slides. To compensate for differences in exposure time of the segments of the filters arising from varying reciprocation velocity due, e.g. to sinusoidal motion, either the intensity of the output image is variably filtered or the intensifier gain is varied. In one embodiment, polarizing filters rotated in synchronicity with the reciprocation of the color preserving filters vary image intensity. In another embodiment, intensifier gain is varied based upon a velocity indicator.