Abstract: A photoelectric smoke detector is equipped with a light emitter for radiating light into a measuring space. A light receiver detects scattered light caused by the presence of smoke in the measuring space. The measuring chamber is constructed as a light trap such that the light beam radiated by the light emitter is multiply reflected and cannot reach the light receiving element of the light receiver.

Abstract: In order to inspect a floppy disk casing for projection of a liner beyond an edge of the casing, a light beam is projected in the direction of the thickness of the casing so that at least a part of the light beam passes near the edge of the casing on the side of the edge opposite to the casing, and whether the liner projects beyond the edge is determined on the basis of the amount of light received by a light receiving means disposed in a direction in which, when a portion of the liner projects beyond the edge, the light beam is scattered by the projecting portion of the liner and which deviates from the direction of straight travel of the light beam.

Abstract: A document scan apparatus in which the position of a document support table relative to an optical system is detected during the relative movement between the document support platen and the optical system. A reference position marker is mounted on the document support table which directly reflects a light from a document illumination light source into an optical sensor array or a CCD sensor array through a mirror and a lens for causing the CCD sensor array to operate in a saturated range to generate a higher output signal level than an expected highest signal level of the CCD sensor array in the document scan operation; and by setting a threshold level of a comparator circuit to a high level which is exceeded by the higher output signal level of the CCD sensor array. The reference position marker is positioned within the field of view of the CCD sensor array for sensing the image of the document, so that the CCD sensor array sensing the document image also senses the reference position marker.

Abstract: A non-metallic fiber-optic device is provided for measuring the level of fluid in a tank, reservoir, or other vessel. Light from a broadband light source is transmitted through a fiber optic waveguide and an optical coupler to an optical pipe sensor which is immersed in the fluid to be measured. The optical pipe sensor includes a monotonically varied diffraction grating in the surface and along the length of the sensor which serves to retroreflect wavelengths of light as a function of the local spacing of the diffraction grating. For light entering the sensor from the waveguide, wavelengths of light corresponding to the local spacing of the diffraction grating above the fluid level are retroreflected, whereas wavelengths of light corresponding to the diffraction grating spacing below the fluid level either escape into the fluid, are absorbed, or are coupled to a return fiber to be detected.

Abstract: A line photosensor comprising a plurality of sensor elements in at least one row on a substrate and a plurality of extract wiring electrodes extending from the respective sensor elements. The extract wiring electrodes are wired in an electrically isolated and laminated manner. The extract wiring electrodes are laminated such that they hold therebetween a laminated structure including a first insulating layer, an intermediate electrode layer formed on the first insulating layer, and a second insulating layer formed on the intermediate electrode layer.

Abstract: An image reading apparatus and method which does not require that two optical elements be focused on one line of a document. A single optical element is provided for simultaneously guiding light reflected from two lines of the document onto light receiving elements arranged in two staggered rows, respectively. The optical element is a glass fiber lens array having a plurality of light focusing glass fibers arranged in linear fashion. The light receiving elements include a photoelectric alloy and are arranged in an effective field of view of the fiber lens array. Since the document is scanned, each line of the document is read by each row of light receiving elements, one row at a time. To form a complete image of the line, the output signals of each of the rows must be synchronized. This is accomplished in a signal processing circuit where the output signal of one row is delayed by a period of time equal to the distance between the two rows divided by the scanning velocity.

Abstract: A fiber optic load measuring system, and method of constructing the same, are disclosed which comprises a light source, a fiber optic attenuator, a photodetector, and a signal processor. The fiber optic attenuator was formed to have a curved portion along the length thereof disposed in low transfer relation with the surface where the load is to be measured. The signal processor is adapted to receive signals from the photodetector and measure variations attributable to the application of a load on the surface. The processor is further adapted to linearly translate the detected variations to compute deformation of the curved portion in response to an applied load.

Abstract: A light beam scanner includes a focus-varying mechanism disposed in a light beam path between a light beam source and a rotating polygonal mirror for adjusting focus position of a light beam as it falls on the rotating polygonal mirror, and a control circuit arrangement for controlling the focus-varying mechanism in synchronism with rotation of the rotating polygonal mirror so that the light beam can fall on the rotating polygonal mirror as a correct linear image at all times for thereby focusing the light beam as a spot image on the image-carrying surface being scanned.

Abstract: An electromechanical control for use with a joystick lever which swivels along x and y axes simultaneously. The control has a light source and two light sensitive phototransistors. The light source emits a beam which is split into two parts. A light control sector is pivoted on the base, and mechanically linked to the lever. The sector is disposed in the paths of the two parts of the split beam, and has two arcuate translucent portions, each translucent portion being on its own radius and the portions having a common center. One part of the beam passes through one translucent portion and the other part of the beam passes through the second. The phototransistors are disposed on that side of the translucent portions opposite the location of the light source. The one translucent portion has a graduated opacity along its length, such that the light arriving at one phototransistor varies as the sector pivots by movement of the lever.

Abstract: A multi-turn shaft position encoder employs a plurality of encoder discs with successive speed reductions of 1:2.sup.n and the generation of n+1 bits of binary data representative of the angular position of the respective discs as the input shaft rotates. Specifically, a high-speed disc is coupled to an input shaft and low-speed disc means is coupled to the input shaft with a speed reduction of 1:2.sup.n relative to the high-speed disc. At least one group of n+1 bits of binary data representative of the angular position of the high-speed disc are generated as the input shaft rotates. A group of n+1 bits of data representative of the angular position of the low-speed disc means is generated as the input shaft rotates. Thus, the low-speed disc is divided in to 2.sup.n units per revolution but produces 2.sup.n+1 bits of data. The data is generated by the encoder in unit distance code and is then converted into fewer bits of data in natural binary code.

Abstract: A photo-electric scanning device 1, with tubular housings 2, 3 with light source 15 and receiving element 16 and 17, respectively, arranged transversely and enclosing a web between them. The receiving element 17 cooperates with the light source 15 either according to the reflection principle or the light barrier principle. For light source 15 two receiving elements 16, 17 are provided which are capable of being actuated, of which either the first 16 cooperates with the light source 15 according to the reflection principle or the second 17 according to the light barrier principle. The first receiver 16 is closer to the light source 15 than the second receiving element 17. In this manner, operation is continuous with both receiving elements 16, 17.

Abstract: An autofocusing control system makes a position of focusing spot follow for itself a displacement of an information medium. In the autofocusing control system, a single mode semiconductor laser is excited in a multi oscillation mode by returning part of a reflected light beam from the information medium, and a focusing lens having chromatic aberration is used which focuses a laser beam from the semiconductor laser onto a different position along the optical axis of the lens in association with a different laser wavelength.

Abstract: Longitudinal tensile and/or compressive strain in optical fibers is detered by an entirely optical technique. A test optical fiber optically coupled to optical injection and extraction couplers form an optically recirculating loop. A semiconductor laser diode feeds a series of narrow light pulses into the loop via the injection coupler and an oscilloscope or signal peak detector give visual indications of optical correlation when an avalanche photodiode provides responsive signals coming from the extraction coupler. Straining the optical test fiber will change the loop's length and, hence, the time delay between reoccurring pulses so that the loop frequency of the narrow optical pulses must be correspondingly changed to provide maximum signal correlation. Changing the pulse repetition rate of the laser diode until a maximum correlated signal is observed at the scope or detector provides a new resonant loop frequency that is proportional to strain.

Abstract: A translational mount for supporting large optical elements, the mount having a stationary support, a mounting ring pivotally attached to the support, a first eccentric ring rotatably mounted within the mounting ring, a second eccentric ring rotatably mounted within the first ring, and an element rotatably mounted within the second ring securing the large optical element thereto. By the appropriate rotational movement of the pair of eccentric rings the optical element is displaced a predetermined amount in both the horizontal and vertical directions.

Abstract: A synchronizing light beam detecting apparatus is provided in a light scanning system, such as a laser printer, which includes a light source for emitting a light beam, a polygonal mirror driven to rotate for deflecting the light beam over a predetermined angle repetitively, and a f.theta. lens for focusing the deflected beam along a predetermined imaginary scanning line. The detector includes a cylindrical lens for receiving the light beam passing through the f.theta. lens and picked up at a predetermined position and a detector surface for receiving the light beam passing through the cylindrical lens. A conjugate relation is established between the light beam deflecting point at the polygonal mirror and the detector surface so that the effect of inclination of a mirror surface of the polygonal mirror is cancelled. The detector surface is so located that the light beam is formed thereon only by the image-forming action of the f.theta.

Abstract: Array of Fresnel lenses moulded in a single sheet of plastic 29 are used in conjunction with a thermal radiation detector 1 to provide intruder alarm apparatus. Each lens defines one detection direction in a fan of such directions 26,27,28. Such arrays have been moulded as a curved surface 22 centered on the detector. To reduce moulding costs while maintaining the optical efficiencies of all lenses in the array, a flat array of lenses is provided in which each lens is moulded as an angled facet 30,31,32. The poles 36,37,38 of the lenses lie in a plane.

Abstract: Scan distortion is eliminated in a light beam positioner utilizing a first mirror for deflecting a light beam in a first direction in response to a first compensated control signal. A second mirror receives the light deflected from the first mirror and, in response to a second compensated control signal, deflects the received light beam at a second angle in a second direction which is orthogonal to the first direction. An objective lens is provided for focussing the deflected light beam produced by the second mirror. A controller means generates first and second uncompensated control signals which are respectively proportional to the first and second angles of deflection. A scan distortion compensating circuit generates first and second intermediate signals which are respectively dependent on the first and second uncompensated control signals.

Abstract: A system for calibrating the time axis of an X-ray streak tube comprising a light source for generating a train of light pulses and an X-ray tube including a photocathode for receiving the light pulses. Upon receiving the light pulses, the X-ray tube generates a train of X-rays which excite the photocathode of the streak tube causing it to emit an electron beam. The electron beam is scanned by a sweep voltage synchronized with the light pulses and applied across deflection electrodes in the streak tube. The deflected beam impinges on the phosphor screen of the streak tube where the time interval of the streak image is measured.

Abstract: There is disclosed a blind person guide device comprising a walking stick, a source mounted on a front face of the walking stick for emitting a beam of infrared radiation in a forward direction, a photoelectric element mounted on the front face of the walking stick for receiving infrared radiation reflected from an object irradiated by the beam, an electric circuit for producing information as to a distance to the object based on the illuminance or energy of received radiation on the photoelectric element, an oscillator for generating electric vibrations having a frequency and an amplitude which are dependent on the distance information produced by the electric circuit, and a vibrator vibratable in response to the electric vibrations and having a vibrating surface against which a human skin can be pressed.

Abstract: Method and apparatus for monitoring the purity of a liquid in a container by passing a laser beam divided into two portions with the first portion passing through a pair of quartz windows with the liquid in a container therebetween, and the second portion being directed through the two windows and the liquid, the first portion being detected to detect the amount of solid particles in the liquid, and the second portion being detected to determine changes in refraction index to obtain a recording of the purity of the liquid.