Abstract: The present invention is to provide a method for identifying an optical line easily and accurately regardless of the optical line length. A plurality of reflecting parts is placed on the optical line, and a combination of relative positions of the reflecting parts is changed for every optical line to form an identification code, and the relative positions of the reflecting parts are detected based on reflected lights when a detecting light is inputted to the optical line, so that the optical line is identified based on a result. Concretely, when the detecting light is inputted to one end of the optical line, the light is reflected at the plurality of the reflecting parts which form the identification code and comes back the input end. A combination of the relative positions etc. of the reflecting parts is changed for every optical line.

Abstract: A method of testing a laser target designator, in which an aperture in the field of view of the laser target designator has one side facing the target image detector and the laser, a beam image detector faces an opposite side of the aperture and is aligned with the opening thereof so that the beam optical axis and the opposite side of the aperture are in a field of view of the beam image detector, both sides of the aperture being illuminated, and beam video processor obtains a test video image from the beam image detector and computes a centroid of the aperture in the test video image and a centroid of the laser beam in the test video image, the displacement of these centroids being a measure of the static error while relative movement of them during dithering of the optical path from the laser target designator is a measure of the dynamic error.

Abstract: High speed pattern and defect detection in flat panel displays, integrated circuits, photo mask reticles, CRT color masks, printed circuit boards, and any other patterned devices, regular or irregular, uses analog optical computing. Using appropriate illumination and optics, the Fourier transform of the image of a device under test is formed. The Fourier transform components of an ideal pattern are compared to the Fourier transform components of a measured pattern, and differences in relative intensities of the spatial components indicate a defect. A spatial separator is used to direct different components of the Fourier transform in different directions for parallel, simultaneous measurement and analysis. Utilizing Statistical Process Control, and properly comparing the different Fourier transform components, the defect is partially classified. Optical image processing is done in real time at the speed of light.

Abstract: Soluble metal complexes for use as standards in wear metal analysis of PFPAE fluids are provided. These standards are the metal complexes of 2,2-dimethyl-6,6,7,7,8,8,8,-heptafluoro-3,5-octanedione (HFOD). These complexes are soluble in PFPAE's to at least 100 ppm metal and are stable over a long period of time (months) in the presence of air. Generally, the metals of interest are Al, Na, Mg, Ca, Ba, Ni, Cu, Zn, Cd, Pb, Hg, Fe, Cr, Mn, V, Mo, Si, Ag, Na, Sn, Ti and Co. Also provided is a method for determining the concentration of at least one wear metal in a PFPAE fluid. This method is particularly suitable for determining determining the concentration of at least one wear metal in a PFPAE fluid by inductively coupled plasma-atomic emission spectroscopy.

Abstract: A System for Collecting Weakly Scattered Electromagnetic Radiation is disclosed. The present invention overcomes problems suffered by previous collection systems by providing a reliable and efficient device for intensifying and collecting the scattered radiation generated by laser induced scattering. The present invention employs a laser source which illuminates an unknown gas contained by a long hollow tube having a highly reflective sheathing. The illuminating electromagnetic radiation from the laser is directed along the entire length of the tube and collides with the molecules of the unknown gas in the tube. The collisions cause the emission of weakly scattered electromagnetic radiation that is shifted in reference to the illuminating radiation. The sheathing is sufficiently reflective of the scattered radiation to substantially contain it. An exit is coupled to the long hollow tube in such a way that the scattered radiation may pass from the reflective sheathing and be collected for analysis.

Abstract: A nephelometer instrument capable of measuring from zero to 10,000 NTUs. The instrument includes four light detectors, three of which are positioned such that they measure light scattered at specific directions by a liquid sample. The fourth detector measures light transmitted through the sample. A removable light filter is also included. The light beam is focused on the front surface of the sample cell.

Abstract: A liquid mercury optical scintillator for simulating atmospheric laser scintillation effects is described which comprises a partially bounded mercury pool, a transducer operatively connected to the the pool for coupling vibrational energy to the surface of the pool, and a detector for measuring spatial irradiance variations in a laser beam reflected from the vibrating mercury surface which variations correspond to probability distributions matching atmospheric In-normal statistics.

Abstract: A displacement detector includes a light generation source for generating light, a scale to be irradiated by the generated light and displaceable relative to the irradiated light, a first detection device having a photo-sensing element for detecting light transmitted through the scale for detecting displacement information of the scale, a mark having a focusing or light-condensing function formed integrally with the scale, and a second detection device having a photo-sensing element for sensing the light-condensed by the mark for detecting a reference position of the scale.

Abstract: Method and apparatus are disclosed for determining the position and attitude of objects, together with robotic systems employing same, and methods of targeting objects for such purposes. Particularly of interest is the application to continuous conveyors, particularly in the process of automobile manufacture. Also disclosed is the use of naturally occuring object features as targets in a machine vision based robot (or other) guidance system. In one embodiment, a special high speed processor finds at least 3 preselected feature points on an object, which when considered with the data base for the object, allows a rapid 6 degree of freedom solution for the object location relative to the camera and thence connected automation. While primarily envisioned for industrial robots, the invention is useful for all sorts of machines including vehicles, construction machinery and the like--anywhere the target object has a known data base relative to the features in question.

Abstract: This invention comprises a sensor (40) having a slit-ray generator (41) and a camera (42), a calibration block (100) for calibrating 3-dimensional coordinate values, a computer (10) for processing 2-dimensional coordinate values of the calibration block (100) and the object (90) to obtain data of 3-dimensional space coordinate and output it to CRT (60), a robot hand (10) for moving the sensor (40) on multiple axes. Therefore, this invention can measure the section profile shape of a tire, etc. accurately and quickly.

Abstract: A scanning exposure apparatus has a mask (reticle) and a photosensitive substrate (a wafer) in an imaging relationship across a projection optical system. A mask stage and a wafer stage are moved simultaneously in first (X) direction with a speed ratio corresponding to the magnification of projection, so that a shot area of the photosensitive substrate is scan-exposed to an original pattern of the mask.The mask is provided, over the scanning range of the original pattern, with mask gratings, each composed of plural grating elements arranged at a predetermined pitch along the first (X) direction. The photosensitive substrate is provided with substrate gratings corresponding to said mask gratings. The positional aberration between said mask gratings and the substrate gratings is detected, through the projection optical system, by positional aberration detecting means.

Abstract: The invention provides a method consisting successively in producing two electromagnetic radiations of the same wavelength that is modulated as a function of time over a range of wavelengths, a "measurement" one of said radiations passing through a gas that presents selective absorption for said radiation in the range, while the other radiation constitutes a "reference" radiation. Each of said radiations is transformed into a respective "measurement" or "reference" electrical signal. The measurement signal is divided by the reference signal to obtain a first quotient electrical signal which is in turn split into two portions: a time-varying AC portion and a DC portion that does not vary with time. The AC portion is divided by said DC portion in order to obtain a second quotient electrical signal representative solely of the electromagnetic radiation absorbed by the gas.

Abstract: The present invention provides a method (100) and device (200) for allocating bits to video pictures in a video compression system. A sequence of video frames or pictures is received, and the number of bits used to compress a previously encoded frame and a signal-to-noise ratio for the immediately previously encoded video frame are determined. Rate distortion model parameters are updated. Then, first, second, and third deviations are determined. Finally, the bit allocation for the frame is determined based on the first number of bits used to compress a previously encoded frame, the first deviation, the second deviation, and the third deviation.

Abstract: A digital video tape recording/playback system having a plurality of recording heads (A, B, C, D) on a rotating head mechanism 94 for recording slanting tracks 108 which extend diagonally across a tape 82 provides processing of video signals in a plurality of data processing channels with selective connection of the data processing channels to the recording heads such that data from a plurality of data processing channels are stored in respective portions of a slanting track (A+/A-; B+/B-; C+/C-; D+/D-). The data in each data processing channel and recorded in each track portion is sampled with a substantially even distribution over a field of video signals to provide for effective concealment of recording/playback errors. Preferably, two data processing channels are recorded on each track, the respective portions being located in upper and lower portions of the tape, respectively.

Abstract: In an apparatus for recording video signals within recording tracks extending obliquely across a magnetic tape, having a rotary drum with first and second pairs of heads spaced from each other pair by a distance corresponding to one track pitch in a direction parallel to the axis of the rotary drum for recording video signals simultaneously on two recording tracks, while sequentially recording video signals on the magnetic tape within the recording tracks the video signals are recorded on said magnetic tape for longer than at the time of normal recording in such a manner that one of the two recording tracks on which the video signals are recorded by one of the second pair of heads overlaps part of the other recording track which is next to the one recording track and on which the video signals are recorded by one of said first pair of heads, so that by controlling the moving speed of the moving means in such a way so as to be slower than the normal moving speed at the time of normal recording, reductions in t

Abstract: A time code format circuit in which information regarding a system state and a tape is formatted on a user's bit area within a time code used for playback/editing in a VCR, thereby easily confirming the operational state of the system and the tape information as well as effectively utilizing the user's bit area.

Abstract: A video accompaniment apparatus provides various screens of high picture quality by using data recorded on a laser disk or a compact disk and data stored in a memory accompaniment apparatus in which a plurality of accompanied songs and song texts are recorded. The background screen for video display is provided by the optical disk apparatus or by an external video unit; the song text is provided by the memory accompaniment unit; the audio accompaniment is provided by the optical disk unit or the memory accompaniment unit or by an external audio unit; and the user's voice is combined with the audio accompaniment selected.

Abstract: An image processing and retrieval system in which images are captured and stored at the remote site where the document processor is located, with codelines from the documents captured and transmitted to a central host computer site, whereby the accounting and financial records may be done at the host computer at the central site and image statements and other image processing activity to process the image may be done at remote sites.

Abstract: An image forming apparatus which is used with an external host computer. The image forming apparatus includes an interface for connecting the image forming apparatus to the external host computer. The image forming apparatus further includes a file system emulator which emulates a file system contained in the disk storage apparatus of the external host computer. The file system emulator makes the image forming apparatus look like the disk storage apparatus to the external host computer connected to the image forming apparatus to transfer images from the external host computer to the image forming apparatus via the interface device.

Abstract: An imagery data memory addressing mechanism writes data representative of respective pixel values of an image into and reads out of immediately successive storage locations of memory, irrespective of whether the number of pixels in the image is the same as or less than the number of storage locations of memory, facilitating the use of a DMA controller and reducing access time. Data values associated with successive pixels of a first line of the m lines of the m.times.n image are stored in successive first through n storage locations of the framestore memory and data values associated with successive pixels of successive ones of second through m lines of the image are stored in successive (n+1) through mn storage locations of the framestore, so that there are no unused or dummy memory locations (in which `fill` data is inserted) between those memory addresses associated with the first line and the last or mth line of the image.

Abstract: Upon writing, a portion of light emitted from light-emitting devices of a light-emitting and light-receiving head 2 is deflected by a half mirror and is then allowed to pass through a first lens array to achieve optical writing on a rotating or moving photoreceptor. Upon reading, on the other hand, light reflected by an original is allowed to pass through a second lens array and then to enter the half mirror. The light is then allowed to pass through the half mirror to the light-emitting and light-receiving head 2 and is hence read by reading devices of the light-emitting and light-receiving head.It is therefore possible to perform writing and reading while the light-emitting and light-receiving head and the optical system remain stationary. No mechanism is therefore needed for moving the light-emitting and light-receiving head, thereby making it possible to provide a scanner-equipped electrophotographic printing machine having small dimensions and high resolution.

Abstract: A low cost, compact light shutter apparatus for a photographic film scanner in which an elongate light shutter mechanism has a curvilinear surface nested in a mating, curvilinear recess formed in an opaque plate. The shutter mechanism preferably is comprised of an elongated blade of sufficient length and width to cover a light transmitting slot in the plate when the blade is in a light blocking position. The blade is attached to a rotary solenoid for movement between light blocking and light transmitting positions.

Abstract: A color separation section for converting colorimetric values into color separation values adopts a neural network. When a color image output device for outputting a color image on the basis of color separation value signals is used, the color image output device to be used outputs a standard color sample having known color separation values. The color sample is colorimetrically measured by a colorimetry device to obtain colorimetric values of the color sample. The neural network executes learning to have conversion characteristics for converting the colorimetric values into corresponding color separation values. An object to be reproduced which has a required color is colorimetrically measured by the colorimetry device. Colorimetric values obtained by the colorimetry processing are converted into color separation values using the neural network of the color separation section. The color image output device outputs a target color based on the converted color separation values.

Abstract: An original document of one or more pages containing human-readable printed information is encoded in one or more two-dimensional bar code symbols and transmitted by facsimile to a remote site where a facsimile of the symbols is machine read, decoded and printed to provide an accurate reproduction of the original document. The facsimile symbol can be facsimile transmitted to another remote site where the facsimile symbol is regenerated, machine read, decoded and printed as another reproduction of the original document. The machine readability of the symbol facilitates computer entry of the original document printed information. The coded symbol may also contain data used at a remote site to control processing and dissemination of the original document printed information.

Abstract: Apparatus and process for reproducing apparatus capable of reproducing a source image, wherein an original intensity value determined on the basis of an intensity at each picture element under consideration of the source image is quantized to one of two levels by comparison of the original intensity value with a threshold value, using a minimized average error technique, and wherein the original intensity value at each picture element under consideration is divided into a plurality of fractions, and each of the is quantized to one of two levels, with the minimized average error technique being practiced for each fraction.

Abstract: A method and apparatus for converting a binary image into a gray scale image includes a pipeline having a number of nearly identical stages. At each stage, modifications occur to provide the gray scale image by following a sequence of steps including: (1) determining a sample mean value representing an averaging of pixel values within a neighborhood containing a selected pixel; (2) determining a weighted variation value representing pixel value variations within the neighborhood; and (3) adjusting the pixel value of the selected pixel toward the sample mean value if the difference between the pixel value and the sample mean value exceeds the weighted variation value. The adjustment to the pixel value is in the direction of the sample mean value. Preferably, the weighting of the variation value is different at each stage. At each stage along the pipeline, low pass filtering is provided to remove high frequency noise generated by the process.

Abstract: A facsimile apparatus in which a single A/D converter used for analog image signals is shared efficiently with other analog sensors. The facsimile apparatus has an image scanner for outputting an analog image signal by scanning an original and at least one analog sensor for outputting an analog detection signal. A multiplexer is provided for selecting one of the analog signals including the analog image signal and the analog detection signal. An analog/digital converter converts the analog signal selected by the multiplexer into a digital signal. A primary scanning counter counts the number of pulses of a pixel clock signal indicating a reading timing of each pixel so as to output a count value, the count value being reset each time a line synchronization signal indicating a first position of each scanning line is supplied thereto.

Abstract: The present invention has for its object to spectrally diffract white light by a hologram for the illumination of a given position, thereby achieving some considerable improvement in the efficiency of utilization of backlight for liquid crystal display, etc., and makes use of a difference in the angle of diffraction of a hologram 5 depending on wavelength to diffract the wavelength components of the colors displayed into liquid crystal cells R, G and B of a liquid crystal display element 10 located at the back side of the hologram 5, thereby achieving some considerable improvement in the efficiency of utilization of backlight. As the hologram 5, an array form of converging unit holograms with the efficiency of diffraction independent, or less dependent, on wavelength, or other equivalent hologram arrangement may be used.

Abstract: An artificial star is disclosed for use with an optical system (10) that has at least one optical axis (14a). The optical system includes an entrance aperture (14) through which the at least one optical axis passes and a radiation detector (22) having a radiation receiving surface. The optical system also includes an optical train having at least one optical element (16, 18, 20). The at least one optical train is disposed for receiving radiation from the entrance aperture, for directing the received radiation along the at least one optical axis, and for focussing the received radiation onto the radiation receiving surface of the radiation detector.

Abstract: A three-dimensional image display device which comprises a holographic plate having a plurality of holograms divided in correspondence with rotational angles, the holographic plate being exposed so that when light is irradiated, each of the holograms forms a point image at a different position in a depth direction of the holographic plate; a drive unit for rotating the holographic plate; a light irradiating unit including a plurality of light sources arranged substantially in a straight line so that the light sources are kept at substantially equal distances from the holographic plate, for irradiating the holographic plate with light from the light sources; and a controller for controlling the drive unit and lighting operations of the plurality of light sources of the light irradiating unit in accordance with a signal indicative of a three-dimensional image to be displayed so as to control lighting of a plurality of point images formed in a three-dimensional space, whereby a three-dimensional image can be obt

Abstract: A broadband cholesteric polarizer is described, as well as a method of manufacturing such a polarizer. Said polarizer comprises an optically active layer of a polymer material having a cholesteric order, said material being oriented so that the axis of the molecular helix extends transversely to the layer. In accordance with the invention, the polarizer is characterized in that the pitch of the molecular helix in the layer is varied in such a manner that the difference between the maximum pitch and the minimum pitch is at least 100 nm. The optically active layers are preferably provided on substrates which bring about a conversion of circularly polarized light into linearly polarized light. Three different methods of manufacturing such broadband polarizers are described.

Abstract: The goggle type display apparatus of this invention comprises a first image generating unit for providing an image for the left eye and a second image generating unit for providing an image for the right eye, each of the first image generating unit and the second image generating unit comprising: a polarization beam splitter for polarizing light emitted from a light source; and a reflection type display device including a substrate, a switching circuit formed on the substrate, a display medium for modulating the light polarized by the polarization beam splitter to provide the light with image information, and an electrode layer electrically connected to the switching circuit for applying a voltage to the display medium, the electrode layer reflecting the light incident thereto after passing through the display medium.

Abstract: A phase difference plate capable of eliminating contrast changes due to viewing angle changes of display image, coloring phenomenon of display screen, and black and white reversal phenomenon, and a liquid crystal display device capable of displaying images of high quality are presented. A phase difference plate is a drawn and elongated material possessing optical anisotropy such as high polymer compound formed in a flat plate form, and the direction of the minimum principal refractive index na of the three principal refractive indices na, nb, nc of the index ellipsoid is parallel to the y-axis direction, and the direction of the principal refractive index nb is inclined to the normal direction of the surface.

Abstract: An electrode substrate for display devices comprises a builtup structure having a resin layer 1, an underlying layer 2 and a pattern of a conductive layer superposed in this order. The underlying layer consists of a SiO.sub.2 film 8 formed by sputtering. The conductive layer 3 consists of a double-layer structure including a first ITO film 9 formed by low temperature sputtering and a second ITO film 10 formed by high temperature sputtering. The SiO.sub.2 film has an internal stress close to zero. The first ITO film 9 has an internal stress in tension and the second ITO film has an internal stress in compression counterbalancing the internal stress in tension therewith. Thus, the builtup structure permits the internal stresses involved in the substrate to be relaxed.

Abstract: Phthalocyanine of formula (I), wherein M is a metal or is 2H, bonded at 29 and 31 positions shown, R.sub.1 to R.sub.8 are the same or different and are independently selected from C.sub.1 to C.sub.20 alkyl, C.sub.1 -C.sub.20 alkenyl, --X--COO--X.sup.1, --X--O--Y, a, and --X--COZ where X is independently selected from a chemical bond, (CH.sub.2).sub.n where n-0-20 or (CH.sub.2).sub.a CH--CH (CH.sub.2).sub.b where a and b are independently selected from 0-20 and a+b is in the range 0-20, X.sup.1 is independently selected from C.sub.1 -C.sub.20 alkyl or C.sub.2 -C.sub.20 alkenyl, Y is independently selected from C.sub.1 -C.sub.20 alkyl, C.sub.2 -C.sub.20 alkenyl or H and Z is selected from OH or NR.sup.1 R.sup.11 are independently selected from H, C.sub.1 -C.sub.20 alkyl and C.sub.2 -C.sub.20 alkenyl. These phthalocyanines may exhibit discotic liquid crystal phases, absorb infra-red radiation and make good Langmuir-Blodgett films.

Abstract: A station-to-station communication system with a built-in testing arrangement in at least one of the stations. The testing arrangement includes a transmitter/receiver pair with associated light/electricity and electricity/light transducers connectable at will by controlled switching means. When the transmitter/receiver pair is connected to each other, electro-optical light signals emitted by the transmitter are returned to the receiver and produce perceptible signals.

Abstract: An add-drop multiplexer includes a first photodector (14), which receives informations in optical form, some of which are to be supplied to users addressees or recipients chosen from among N users addressees or recipients associated with the wavelengths L1, . . . , LN, whilst the other informations form an output flow at wavelength LO, a second photodetector (16) receiving in optical form informations to be inserted in said flow, a tunable source (18), which converts the signals from the first photodetector into optical signals of wavelengths chosen from among LO, L1 . . . LN under the control of control unit (20) and as a function of their destination, another source (22), which converts the signals from the second photodetector into optical signals of wavelength LO, a coupler (24) connecting the sources to N+1 filters (f0 . . . , f3) only respectively permitting the passage of LO . . . LN. Application to optical telecommunications.

Abstract: A star type multi-stage network having the same connectivity graph between stages and having a physical topology of a star form, comprises a plurality of columns assigned with different specific transmission wavelengths, respectively, NIU's each including a transmitter for making a transmission on a wavelength assigned to a column to which that NIU (network interface unit) belongs and a receiver for receiving a wavelength assigned to a column from which reception is to be made, and a fundamental connection section including a connection portion formed by optical fibers or optical waveguides to provide a fundamental connection pattern between stages. Inputs and outputs of the optical fibers or optical waveguides are connected to couplers having inputs or outputs the number of which is equal to at least the number of the transmitters of the NIU's. Outputs of the transmitters of the NIU's are connected to inputs of the fundamental connection section corresponding to connectivity between stages.

Abstract: A photonic frequency routing type time division highway switch which requires no conflict control at the input side, and incorporates no inherent splitting loss of the optical signal power. The switch is formed by a plurality of tunable frequency convertors for allocating frequency channels to the optical signals on the input highways at each timeslot; a frequency router for connecting the optical signals outputted from the frequency convertors to its outputs according to the frequency channels allocated to the optical signals at each timeslot; and a plurality of frequency multiplexed output buffers for outputting the optical signals outputted from the frequency router to the output highways such that a plurality of optical signals with different frequency channels which are in an identical timeslot are outputted at different timeslots.

Abstract: An optical switching system to which a plurality of input transmission lines and output transmission lines for transmitting optical signals are arranged and connected, and in which fixed length cells transmitted from the input transmission lines are switched based on the routing information contained in the cells and the switched cells are outputted to the output transmission lines includes: optical cell synchronizer portions for detecting the fronts of the cells and synchronizing the fronts of the cells incoming from respective transmission lines; a switching portion for converting respective cells the fronts of which are synchronized to those of different wavelengths by input transmission lines and for switching them based on the routing information in the cells; multiplexer portions for wavelength division multiplexing the cells switched to different wavelengths by input transmission line with respect to respective output transmission lines; demultiplexer portions for splitting cells wavelength division mu

Abstract: In an optical ATM switching system, an optical ATM cell is produced in response to an incoming ATM cell so that it contains an optical routing bit in a timeslot corresponding to the destination of the cell. A first switching stage is provided for routing the cell from one of its inlets to one of its outlets in accordance with the routing bit contained in the cell and generating a routing signal indicative of the position of the outlet to which the cell is routed. A second switching stage is connected to the outlets of the first switching stage for routing the cell to one of optical buffers in response to the routing signal from the first switching stage. Optical combiners are provided, each corresponding to a group of the optical buffers for combining outputs of the corresponding group of optical combiners.

Abstract: A lighting system having an electric lamp controlled by an infrared remote controller. The remote controller incorporates a commercially available transmitter and receiver which reliably functions in the presence of infrared noise having frequencies at and about the carrier frequency of the transmitted signal. The remote controller receiver outputs a demodulated signal and a filter acts on the demodulated signal to remove noise present in the demodulated signal caused by the electric lamp by comparing measured time intervals between leading and trailing edges of the demodulated signal to predetermined values defining data elements.

Abstract: A method, circuit, and apparatus for mitigating effects of wavelength-dependent atmospheric transmission characteristics on an atmospheric optical telecommunication system. The system comprises two atmospheric optical telecommunication units communicating with one another using light propagated through the atmosphere. Each of the atmospheric telecommunication units includes an optical transmitter having a laser generating a transmitted light beam for reception by the other, and an optical receiver. The optical receiver generates an electrical signal in response to a received light beam received from the other of the atmospheric optical telecommunication units. In the method, an increase in noise above a normal noise level is detected in the electrical signal, and a flag signal is generated in response. The increase in noise is due to the received light beam having a wavelength at which the atmosphere has a wavelength-dependent transmission characteristic.

Abstract: An apparatus for locating a remote control transmitter which controls an electronic or electric device, such as a TV, VCR, or air conditioner. The apparatus includes two detecting units disposed at different angles, and the different infrared signal strengths received according to directivity of the location detecting units is transformed into a time value from which the accurate location of the remote control transmitter can be obtained. The apparatus is simple and the detecting operation of the remote control transmitter is reliable and precise.

Abstract: A scanning optical apparatus has a source (1) of light for producing a light beam as a light flux (5) in a given direction, a polariscope (2) for polarizing the light flux (5) of the light beam in another given direction, a member or medium which is scanned by the light flux (5) of the light beam while the light flux (5) of the light beam is polarized by the polariscope (2), and a plastic lens (3) placed between the polariscope (2) and the scanned member or medium (4) for forming an image spot on the scanned member or medium (4). The plastic lens (3) has two kinds of surfaces, one of which is a polarization surface or optical surface through which the light flux (5) of the light beam passes, and the other of which is a non-polarization surface or non-optical surface through which the light flux (5) of the light beam does not pass. All of the surfaces of the plastic lens (3) have dampproofing characteristics.

Abstract: An optical scanning device for leading a laser beam emitted from a semiconductor laser diode through a collimator lens, an imaging lens, and a cylindrical lens to a plurality of reflecting surfaces of a rotatable polygon mirror, and scanning a surface to be scanned movable in a vertical scanning direction with the laser beam reflected on the reflecting surfaces of the polygon mirror and transmitted through a correcting lens. The optical centers of the semiconductor laser diode, the collimator lens, the cylindrical lens, a return mirror, and the correcting lens are located in a plane containing an axis of rotation of the polygon mirror. The semiconductor laser diode, the collimator lens, and the cylindrical lens are located over an upper surface of the polygon mirror. Accordingly, an optical system can be formed in symmetry with respect to a center axis of an optical path of a horizontal scanning light beam from the polygon mirror without interference of the semiconductor laser diode, etc.

Abstract: An array of M.times.N electrodisplacive actuated mirrors for use in an optical projection system is assembled by way of: (a) preparing a ceramic wafer made of an electrodisplacive material, having a top and a bottom surfaces; (b) providing on the bottom surface of the ceramic wafer an array of M.times.N first electrodes; (c) forming a first metallization on the top surface thereof; (d) mask bonding; (e) forming an array of M.times.N actuating members by providing M trenches thereon using a sandblasting method; (f) mounting the ceramic wafer on an active matrix; (g) mask removing; (h) forming a second metallization; (i) providing a first photoresistive layer; (j) electroforming; (k) removing the first photoresistive layer; (l) providing a second photoresistive layer; (m) forming a platform with a flat top surface; (n) providing a light reflecting layer; (o) pattern the light reflecting layer, including the platform, into an array of M.times.

Abstract: In an external modulator for optical communication, a piezoelectric element section is formed by laminating a lower electrode, a piezoelectric thin film and an upper electrode in this order on one surface of a substantially flat substrate which has substantially the same acoustic impedance as the clad layer of a single mode optical fiber to be disposed on the substrate. At least one single mode optical fiber is disposed on the other surface of the substrate on the upper electrode, and the single mode optical fiber is at least partly coated with a material having an acoustic impedance substantially equal to that of the clad layer in a place in which the single mode optical fiber is disposed.

Abstract: An optical wavelength converting device is provided with a LiTaO.sub.3 substrate, a plurality of inverted-polarization layers periodically arranged in an upper surface of the LiTaO.sub.3 substrate, and an optical waveguide crossing the inverted-polarization layers. The upper surface of the LiTaO.sub.3 substrate is directed toward a -X-crystal axis direction. The inverted-polarization layers are formed by exchanging Ta.sup.+ ions of the LiTaO.sub.3 substrate for H.sup.+ ions, and an extending direction of each inverted-polarization layer is inclined at an angle of .theta. degrees (6.ltoreq..theta..ltoreq.174) to the +C-crystal axis direction toward a -Y-crystal axis direction. The optical waveguide is formed by exchanging Ta.sup.+ ions of the LiTaO.sub.3 substrate and the inverted-polarization layers for H.sup.+ ions to set a refractive index of the optical waveguide higher than that of the LiTaO.sub.3 substrate. The optical waveguide extends in a +Y-crystal axis direction.

Abstract: In an optical receiver of the prior art, a multistage fiber-optic amplifier in which optical signal components propagating along different paths in the same direction beat with one another generate noise in addition to the noise due to spontaneous emission in the amplifier. A two-stage fiber-optic amplifier, according to the invention is provided in which a first section of optical fiber (F1) is pumped opposite to or in the direction of propagation of the optical signal and a second section of optical fiber (F2) is pumped in or opposite to the direction of propagation. A pump-light source (1), the sections of optical fiber (F1, F2), and couplers (K1, K2, K3) are arranged in such a way that any signal components propagating along different paths in the same direction will not beat with one another.