Abstract: An apparatus for determining the optical retardation of a material. The apparatus includes a light source emitting light along a light path, and a lens disposed in the light path intermediate the light source and a sample of the material. A waveguide directs the light from the light source to the sample and directs light reflected from the sample to a wavelength analyzer, whereby the wavelength analyzer detects the wavelengths of the reflected light. The apparatus of the present invention includes a sole polarizing element disposed in the light path intermediate the light source and the wavelength analyzer.

Abstract: A focus monitor for establishing best focus of a lithographic system in semiconductor wafers. The focus monitor has a phase region having a first phase and a slot disposed within the phase region having a gap size indicative of a defocus level of the lithographic system.

Abstract: A multiple optical head interferometer comprises one Light Source-Detection-Computing unit and multiple optical heads. The diameters of all of the optical heads are of equal size, and oriented in the same direction. Shutters or adjustable mirrors are provided such that the Light Source-Detection-Computing unit is used with only one optical head at a time. The multiple optical head interferometer of the present invention may measure many workpieces quickly in a short time, as while one workpiece is being measured, others may be setup for measurement or removed for further processing. In a first embodiment, the branching device for branching the laser beam comprises a plurality of beam splitters. Shutters are used to control which optical head is to be used with the Light Source-Detection-Computing unit at a particular time. In the second and preferred embodiment of the present invention, branching out of the optical heads is achieved by using adjustable mirrors and reflection.

Abstract: The invention relates to a method of operating an opto-electronic sensor, in particular a light barrier, in which a light signal is transmitted by means of a light transmitter into a monitored region and a light receiver designed to receive transmitted and reflected light signals delivers a signal, the amplitude of which is investigated for the presence of an object in the monitored region, wherein an object detection signal is transmitted when an amplitude threshold value is exceeded or fallen short of, wherein, before taking the sensor into operation, the threshold is automatically set in dependence on amplitude values which occur in a predetermined measurement time interval in the context of an initialization process with an object-free monitored region, and is thereby adapted to the operating conditions which exist during the initialization process, or wherein the threshold value is automatically adjusted during the sensor operation in dependence on amplitude values which have occurred in a specific measu

Abstract: Precision optical mounts that carry and reliably position an optical element so that a plurality of such optical mounts can be arranged in a compact and optically efficient system, wherein opposing optical elements are held in relatively close proximity to one another without introducing distortion. A stationary back plate is arranged in spaced facing alignment with a face plate for importing a tilting or translational movement to the face plate and to an optical element that is to be carried thereby. The optical mount may be disposed in vertical, upstanding alignment with respect to a support surface to position the optical element (e.g. a mirror) to receive a beam of optical energy. In the alternative, the optical mount may function as a mounting platform to be disposed in horizontal alignment with respect to the support surface so that an optical element (e.g. a prism) can be supported thereupon.

Abstract: An autocollimator/point-range sensor system produces a linearly polarized light beam that is split into a point-range sensor beam and an autocollimator beam. The linearly polarized point-range sensor beam is utilized to carry out z-position measurements according to prior-art techniques. The autocollimator beam is passed through a quarter-wave plate to introduce a 90-degree phase shift and convert it to circularly polarized light. An analyzer placed in front of the autocollimator detector is positioned such that its transmission axis is offset with respect to the plane of polarization of the linearly polarized point-range sensor beam, thereby blocking any scattered light from the sensor beam while passing a component of the circularly-polarized autocollimator light to reach the detector.

Abstract: A surface plasmon sensor comprises a prism, a metal film, which is formed on one surface of the prism and is brought into contact with a sample, and a light source for producing a light beam. An optical system causes the light beam to pass through the prism and to impinge upon an interface between the prism and the metal film such that various different angles of incidence may be obtained with respect to the interface. A photodetector detects an intensity of the light beam, which has been totally reflected from the interface, with respect to each of the various different angles of incidence. An electrode stands facing the metal film with a liquid sample intervening therebetween, and a DC voltage is applied across the electrode and the metal film. A substance contained in the liquid sample is thus analyzed quickly and with a high sensitivity.

Abstract: Apparatus for inspecting the surface of a sample includes a wide scanning interferometer, which is used to locate defects, or anomalies in the surface, and a narrow scanning interferometer, which is used to develop profiles of individual defects found by the narrow scanning interferometer. The sample may be driven in rotation about an axis, while the interferometers are independently moved radially to the axis.

Abstract: An apparatus and method for providing an indication of a type of note passing through the apparatus includes a note transport (12) which moves the note past transversely spaced spot sensing assemblies (18). Each spot sensing assembly includes four emitters (32). Each of the emitters produces radiation at a different wavelength. The spot sensing assemblies include a reflectance detector (20) and a transmission detector (22) which are disposed on opposed sides of the passing note. The emitters direct radiation onto test spots (34) on the passing note. The emitters in each assembly are activated individually and repeatedly in a sequence. Radiation reflected from each type of emitter to the reflectance detector at each test spot causes a control circuit (24) to generate reflectance values. Radiation transmitted from each emitter through each test spot to the transmission detector causes the control circuit to generate transmission values.

Abstract: According to the method the intensity of at least one pressure-independent (impurity detection) or pressure-dependent (gas pressure determination) spectral line is measured selectively. Indirect detection utilizes the intensity of spectral lines whose wavelengths correspond to higher levels of excitation energy than those of the impurities. The intensity of these spectral lines is a measure of the impurities. Alternatively, the intensity of at least one spectral line of the respective impurity is measured directly. In order to eliminate co-phasal interference, two spectral lines are measured and the ratio is formed therefrom. The intensity ratio of argon lines of wavelengths .lambda..sub.1 =772.4 nm and .lambda..sub.2 =738.4 nm has in particular proved acceptable for the indirect detection of impurities in argon and the intensity ratio V of the argon lines of wavelengths .lambda..sub.1 =763.5 nm and .lambda..sub.2 =738.4 nm has proved acceptable for determining the argon pressure.

Abstract: A system and method for inspecting a moving container on a conveyor. An encoder assembly detects movement of the conveyor and generates a signal representative of the speed of the container as a function of the movement of the conveyor. A light source adjacent the conveyor illuminates the container and a camera adjacent the conveyor generates a plurality of successive images of portions of the illuminated container. The images each include a plurality of pixels, each having a value representative of an optical characteristic of the images. The camera is controlled to generate the successive images as a function of the speed of the moving container. An image processor acquires a two-dimensional image of the container from the successive images generated by the camera and processes the two-dimensional image as a function of the pixel values to detect edges in the image for inspecting the container.

Abstract: A wiper control apparatus of the water drop sensitive type for detecting of the amount of water or water drops adhering to or present upon the front surface of a windshield and for driving a wiper, comprising: a light emitting means for introducing light into the inside of the windshield so that the light experiences total internal reflection upon interior surfaces of the windshield; a light receiving means for receiving the light reflected within the windshield; means for turning a first output D1, a second output D2, and a third output D3 to either an H level or an L level in response to the level of a signal output from the light receiving means, the outputs being preset in sequence of height of sensitivity thereof; means for outputting a drive signal WD for the wiper when outputs D1, D2, and D3 are switched into the H level; means for maintaining the drive signal as long as the second output signal D2 is in the H level even if the third output D3 turns to the L level; and means for stopping the drive sign

Abstract: A mechanism for aligning the elements of an optical system is disclosed. One aspect of the present invention is an alignment mechanism which includes lead screws placed on opposite corners of the elements to be aligned. The elements are provided with threaded holes of different pitch, and the lead screw is provided with threads of the same unequal pitches as the elements, thereby forming a differential lead screw. The threads include a locking thread which assures a positive lock between the lead screw and the elements to be aligned and eliminates backlash between them. Another aspect of the present invention is an interference fit mechanism which is provided by the employment of a slightly-oversized flexible boss which mates with a cavity. The boss is provided with a thin outer wall capable of flexing when the boss is inserted into the cavity. Yet another aspect of the present invention includes a wobble plate comprising a spherical socket and housing.

Abstract: In a method and apparatus for analyzing an unknown material, the spectra of absorption and remission coefficients are determined by means of equations relating to remission, absorption and transmission fractions through layers of material of different thicknesses in accordance with a discontinuum theory. To determine the concentration of an absorber in an unknown material, the absorption coefficients are determined for the unknown material and for samples of known material. The concentrations of absorbers in the unknown material are determined from the absorption coefficients by regression analysis.

Abstract: A depth-from-defocus optical apparatus is provided for use with a depth-from-defocus three-dimensional imaging system for obtaining a depth image of an object. The invention facilitates the formation of depth images of objects exhibiting specular reflection, either alone or in combination with diffuse reflection, thereby allowing the application of depth-from-defocus three-dimensional imaging to objects such as microelectronic packages. The optical apparatus of the invention generally includes an illumination source, a projection lens assembly for converging rays of incident light towards an object, and a viewing lens assembly for converging rays of reflected light towards an image plane. Importantly, the viewing lens assembly is of the same working f-number as the projection lens assembly.

Abstract: The invention relates to a photomechanical transducer which comprises a photochromic element made of a first material and attached on a carrier element made of a deformable second material. The first material of the photochromic element changes its molecular shape when it is irradiated with light and thereby introduces a strain into the carrier element which as a result is deformed.

Abstract: A positioning apparatus and a method which enables precise positioning of a mask and a wafer without being influenced by the deviation of the gap between the mask and wafer or the positional deviation of the irradiated light beam. A light beam irradiates on a first mark of a first object and a second mark of a second object. The relative position of the two objects is detected on the basis of a plurality of spot images of the light beam transmitting through the two marks, or being reflected upon or diffracted upon the marks. Each centroid of the plurality of spots is detected and a first alignment amount is obtained; in addition, a correction amount for the first alignment is obtained by applying the fuzzy inference method based on an additional signal, such as the positional relation of the first and second objects or the positional relation of the irradiated light beam and the first mark.

Abstract: A light beam from a light source is formed into an annular beam and an inner wall of a hole in an object is illuminated with the annular beam.

Abstract: An optical inspection module detects defects on an active surface of a substrate in an integrated process tool system. The optical inspection module includes an enclosure, a substrate holder, a light source, a light beam path, a lens and a photodetector array. The light source has a light beam port. The light beam path extends from the light beam port to the substrate holder and has a grazing angle of incidence with respect to the active surface of the substrate. The light beam path illuminates substantially the entire active surface. The lens is oriented to collect non-secularly reflected light scattered from the light beam path by any defects on the active surface. The photodetector array has a plurality of pixels which are positioned within a focal plane of the lens. Each pixel corresponds to an area on the active surface, and the plurality of pixels together form a field of view that covers substantially the entire active surface.

Abstract: A method of the invention for inspecting a defect on a translucid film is provided. The method includes an anti-reflective coating (ARC) layer over the translucid film. The anti-reflective coating (ARC) layer prevents inspecting light from penetrating through the ARC layer and reduces the amount of inspecting light refracting through the translucid film. The inspection is performed by generating an inspecting light with a predetermined angle radiating on the ARC layer. The reflecting light message from different regions of the anti-reflective coating (ARC) layer are separately collected. The reflecting light messages are compared die to die to calculate an inspecting result.