Abstract: The electrochromic element comprises an electrochromic layer (22) whose transmission properties change when a voltage difference is applied across the element. Said electrochromic layer (22) comprises a first metal oxide of the group formed by WO.sub.3, MoO.sub.3, Nb.sub.2 O.sub.5, MnO.sub.2 and ZrO.sub.2 (and combinations thereof) and a second metal oxide containing V.sub.2 O.sub.5, TiO.sub.2 and/or ZnO. If the concentration of the second metal in the mixture ranges from 1 to 15 at. %, preferably from 3 to 10 at. %, the electrochromic layer (22) is transparent and colorless if no guest atoms are incorporated in the layer, and it is (color neutral) grey if a substantial concentration of guest atoms is incorporated in the layer.Electrochromic elements are provided, for example, on the outer surface of a display screen of a display device.

Abstract: Whether or not an object is present, the surface state of the object, the material constituting the object and the presence of scattering bodies are discriminated through a simple arrangement which includes a light-emitting element for projecting light upon an object to be sensed, and a polarization beam splitter upon which light reflected from the object (or light transmitted through or scattered from the object) impinges. Reflected light from the polarization beam splitter is received by a first light-receiving element, and transmitted light from the polarization beam splitter is received by a second light-receiving element. The aforesaid discrimination is performed on the basis of the value of S/P, S-P, S-kP or (S-P)/(S+P), where S and P represent light-reception signals from the first and second light-receiving elements, and k is a constant.

Abstract: An apparatus and method for measuring in real time the eccentric error of a rotating body, particularly an encoded optical disk. An eccentricity measurement pattern comprising a plurality of concentric spaced apart diffraction rings are included on an encoded disk. An error read head with a plurality of laser beams is positioned to reflect laser light off the eccentricity measurement pattern on the disk. The relative radial spacing of the laser beams on the error read head is adjusted to a non-integral multiple of the radial spacing of the diffraction rings. Output signals from the error read head are generated according to reflected laser light from the eccentricity measurement pattern which is detected by the error read head. The output signals are converted to count and direction information.

Abstract: A device and process for measuring and analyzing spectral radiation within a desired wavelength range. A number of radiation sources are provided, in combination with a sensor for detecting radiation within the desired wavelength range. The radiation sources are selected to have spectral characteristics that are linearly independent from one another, but overlap so that, in combination, the radiation sources generate radiation over the entire desired wavelength range. Alternatively, a single radiation source generating radiation over the entire desired wavelength range is provided in combination with a plurality of sensors that have spectral sensing characteristics that are linearly independent from one another, but overlap so that, in combination, the sensors sense radiation over the entire desired wavelength range.

Abstract: Apparatus for distinguishing between genuine and counterfeit articles whereby a first optical filter is applied to genuine articles and suspect articles are scanned with the aid of a suitable second optical filter. Scanning of genuine articles incorporating first optical filter with the aid of suitable second optical filter gives rise to optical effects which would not otherwise be apparent.

Abstract: A micromechanical optical modulator having a linear response in reflectivity, as a function of applied bias, and a method of operating and making same, are disclosed. The modulator consists of a movable layer suspended over a substrate. A gap is defined between the movable layer and the substrate. As the movable layer moves, the gap changes size, resulting in a change in modulator reflectivity. In operation, the movable layer moves within a linear operating regime under the action of an applied voltage, which is the sum of a constant bias and a signal from an analog source. A substantially linear operating characteristic, i.e., reflectivity versus applied voltage is obtained within the linear operating regime by properly selecting the size of the gap in the absence of the applied voltage and the range in the applied voltage.

Abstract: The present invention provides a measuring apparatus (10) for centering and determining wedge error of an optical element (12) under test. The measuring apparatus (10) preferably includes a lens holder (16) for supporting the optical element (12) to be tested. The lens holder (16) is rotatably supported on an air bearing (68) having an axis such that the lens holder (16) may be rotated about the axis. A first sensor (18) is located proximate the lens holder (16) for measuring the wedge characteristics of the optical element (12). The first sensor (18) is movable in a horizontal, vertical and rotatable direction such that the first sensor (18) may be positioned to a predetermined distance from the optical element (12) at a preselected angle. A second sensor (20) is located proximate the lens holder (16) for measuring centering characteristics of the optical element (12).

Abstract: The present invention involves an apparatus and a method for optically detecting and determining the angular position of a target. The apparatus comprises a pair of optic sensors arranged so that at least a portion of their sensing areas overlap. Their overlapping areas define the total sensing, or active sensing, area for the apparatus. Each of the optic sensors in the apparatus senses light, or other optically sensible transmission, either projected or reflected from a target positioned within the total sensing area and produces a signal relative to the amount of light sensed. The signals are then interpreted to determine the angular position of the target based on the relative signals from the optic sensors. The method of the present invention determines the angular position of a target within an area, defined by the overlapping sensing areas of a pair of optic sensors, by interpreting the relative signal intensities from the pair of optic sensors.

Abstract: An optical surface inspection system is designed to correct for misregistration errors. A reference vector of data samples is obtained by computing an average of adjacent data sample vectors. A comparison of the data samples in a current vector being processed to data samples that may be offset from such current vector along the direction of the current vector enables the detection and correction of misregistration errors. Alternatively, a target array of data samples is compared to a reference array of data samples collected from a different portion of the surface with various offsets for detection and correction of misregistration errors. The intensity of the reflection from the inspection beam may be monitored to vary the intensity of the inspection beam so as to reduce the dynamic range of background scattering.

Abstract: A soft focus lens which is designed as a retrofocus type lens, comprises a front lens group having a negative power, a rear lens group having positive power, and a diaphragm located within the rear lens group. The front and rear lens groups are arranged in this order from an object side. In particular, the soft focus lens satisfies the following conditions;SAU/f<-0.10 (1)f/fF<-0.5 (2)whereSAU is spherical aberration at full open aperture, f is focal length of the whole lens system, and fF is focal length of the front lens group.

Abstract: Two detectors are effectively positioned at a predetermined lateral position in a rectangular illumination field at a wafer plane. The ratio of the signals from the two detectors is calculated. This ratio is indicative of the quality of the illumination field and any lamp instability which may effect the illumination field, and therefore image quality. In a photolithographic device, a short arc mercury xenon lamp provides illumination for projecting the image of a reticle onto a photosensitive resist covered substrate or wafer. The desired illumination intensity profile is sensitive to lamp instability. This instability may alter the desired illumination intensity profile which may adversely effect image quality, and therefore the resulting product. The ratio of the signals received from predetermined locations laterally along the illumination intensity profile improves the detection of unstable lamps.

Abstract: An apparatus and method for the testing of materials by thermal oxidation is provided. The apparatus comprises a housing having at least one optic-isolated chamber. A photon counting photomultiplier and a heat source, for each optic-isolated chamber, are also provided within the housing. A cell, having a plurality of gas inputs and gas outlets, for holding a sample to be tested, is provided within the housing for each chamber. The gas inputs and outputs are distributed about the cell so as to disperse gas evenly about the material to be tested. The apparatus is used to count the number of photons which escape from a test sample as various oxidation conditions are employed.

Abstract: An all fiber-optic in-line photopolarimeter is disclosed. This photopolarimeter replaces the conventional 1.times.2 coupler, bulk beamsplitter and accompanying optics with a single 1.times.5 star coupler. This system can measure state of polarization of light in a fiber in situ.

Abstract: An optical wheel alignment apparatus intended for race cars and other high performance road vehicles which provides an extremely accurate, low-cost, light-weight, portable and non-electrical method for toe and camber alignments even in space limited and hostile environments such as race car pit areas. Further, the apparatus is simple to operate, requires less that five-minutes set-up time and provides repeatable accuracy up to two minutes of a degree toe and 1/8" camber without the aid of computer control.

Abstract: A lenslet array system for imaging an associated object onto a final image plane includes (i) a first lens assembly including a field limiting mask and a first lenslet array having an associated image plane, (ii) a second assembly including a rear lenslet array, and (iii) a middle lenslet array located between the first and said rear lenslet array. The first lenslet array accepts a full field of view subtends by the associated object and forms a plurality of image sections of the associated object on an intermediate image plane. The first lenslet array includes a plurality of positive power lenslets, each of the plurality of lenslets having a focal length f.sub.1 and accepting a unique segment of the full field of view subtended by the associated object. These segments of the full field of view together comprise the full field of view, and each of the lenslets forms one image section corresponding to its segment of the full field of view. The rear lenslet array has a plurality of positive power lenslets.

Abstract: A contamination detection apparatus is provided for measuring an amount of contamination on an optically transmitting element or pane. The optically transmitting element is capable of transmitting electromagnetic radiation. The contamination detection apparatus includes a contamination detection (CD) radiation source for providing a source intensity of radiation. The source intensity or radiation passes through the optically transmitting element at least one time. A reference detector is also provided for detecting the source intensity of radiation, and the reference detector has a reference output level that is representative of the source intensity.

Abstract: A system and method for increasing the number of bits available for use in a video display system that includes at least one spatial light modulator. The system uses a wheel (30) of three colors, or a color wheel that is clear, including at least one segment (34) which has a lower intensity region, referred to as a neutral density filter. Alternately, the filter could be a liquid crystal controller to control either light amplitude or color. By using a lower intensity region, the amount of time available to process the least significant bit of the data sample is lengthened, thereby eliminating the constraint on the number of bits available for display.

Abstract: A method for determining the thickness of a thin sample is described. The method includes the step of exciting time-dependent acoustic waveguide modes in the sample with an excitation radiation field. The acoustic waveguide modes are detected by diffracting probe radiation off a ripple morphology induced on the sample's surface by the acoustic waveguide modes. The diffracted probe radiation is then analyzed to measure phase velocities or frequencies of the acoustic waveguide modes. A thickness of the thin sample is determined by comparing the measured phase velocities or frequencies to the phase velocities or frequencies calculated from a mathematical model.

Abstract: A photomask defect inspection method is provided by which defects of pin holes with the diameter equal to or less than 0.35 .mu.m can be detected with certainty. According to the inspection method, a pattern whose image is projected onto an imaging position by the use of illumination light (P1) for exposure consists of light transmitting portions (41) formed on a glass base (2) and light intercepting portions (42) which transmit part of the illumination light (P1) in such a way that a phase of the part of the illumination light (P1) passing through the light intercepting portions (42) is delayed with respect to a phase of the illumination light (P1) passing through the light transmitting portions (41).

Abstract: In a device for measuring feeble light and a method thereof, the device includes a feeble light amplifying device having a reaction chamber with two transparent windows as a constituent part, a detector, and two mirrors. The feeble light generated in the reaction chamber in which an etching process is in progress is amplified by the mirrors and is then detected, whereby an etching endpoint can be accurately determined. Therefore, the damage to semiconductors due to overetching or underetching can be prevented.