Abstract: A method for determining the centrality of masks is disclosed. The mask is positioned in a coordinate measuring device on a measurement table displaceable in a direction perpendicular to the optical axis of an imaging measurement system in an interferometrically measurable way. The position of a mask coordinate system with respect to the measuring device coordinate system is determined based on at lest two structures on the mask. The relative distance from one of the at least first and second outer edges to the at least two structures is determined. The coordinate measuring machine determines the actual coordinates of the at least two structures with respect to the respective outer edges, which must not exceed a predetermined deviation from a desired value.

Abstract: A lithographic apparatus includes a displacement measuring system configured to measure the position of a substrate table in at least three degrees of freedom. The displacement measuring system includes a first x-sensor configured to measure the position of the substrate table in a first direction and a first and a second y-sensor configured to measure the position of the substrate table in a second direction. Said displacement measuring system further comprises a second x-sensor. The first and second x-sensor and first and second y-sensors are encoder type sensors configured to measure the position of each of the sensors with respect to at least one grid plate. The displacement measuring system is configured to selectively use, depending on the position of the substrate table, three of the first and second x-sensors and the first and second y-sensors to determine the position of the substrate table in three degrees of freedom.

Abstract: According to one aspect of the invention, there is provided a sensor device which is capable of detecting a state of a movable stage using an easily manufacturable reference grating and capable of improving the accuracy of detection. The sensor device comprises a reference grating which has a configuration that is varied periodically in a two-dimensional direction. A light source emits light to the reference grating. A spectral unit has a plurality of openings to convert the light emitted by the light source into a plurality of light beams through the plurality of openings. A detector unit has a photodetector to receive collectively reflected light beams reflected by the reference grating. The detector unit is provided to detect a state of a movable body relative to the reference grating based on a change of the reflected light beams received by the photodetector.

Abstract: Systems and methods for calibrating a solid-imaging system (10) are disclosed. A calibration plate (110) having a non-scattering surface (140) with a plurality (150) of light-scattering fiducial marks (156) in a periodic array is disposed in the solid-imaging system. The actinic laser beam (26) is scanned over the fiducial marks, and the scattered light (26S) is detected by a detector (130) residing above the calibration plate. A computer control system (30) is configured to control the steering of the light beam and to process the detector signals (SD) so as to measure actual center positions (xA, yA) of the fiducial marks and perform an interpolation that establishes a calibrated relationship between the angular positions of the mirrors and (x,y) locations at the build plane (23). The calibrated relationship is then used to steer the laser beam in forming a three-dimensional object (50).

Abstract: The present invention provides an optical displacement meter which performs a profile search for performing positional adjustment of a profile shape.

Abstract: A system for sensing an absolute two-dimensional position of an object having a two-dimensional target pattern thereon comprises a sensor and a controller. The sensor is for capturing an image of a subset of the target pattern. The controller is for generating a first image vector representing summations of rows of pixel values from the image, and a second image vector representing summations of columns of pixel values from the image. The controller is configured to determine an absolute two-dimensional position of the subset of the target pattern with respect to the origin of the target pattern based on the first image vector, the second image vector and target vectors that represent the target pattern.

Abstract: A method of measuring shot shape includes sequentially exposing a substrate with main scale marks (32) in compliance with a predetermined map, and forming a reference grid including a plurality of the main scale marks (32) arranged in the predetermined map in at least one shot region, exposing a shot for measuring, via a projection optical system, that includes a plurality of auxiliary scale marks (34) arranged in the predetermined map in the shot region, measuring a relative positional relationship between adjacent main scale marks (32), measuring an amount of deviation between the main scale marks (32) and the auxiliary scale marks (34), and correcting the reference grid based on the relative positional relationship, and calculating a shot shape of the shot for measuring based on the corrected reference grid and the amount of deviation.

Abstract: A three-grating type photoelectric encoder includes a second grating formed on a scale and first and third gratings disposed on a side of a detector. A part of at least the first grating is shifted in a direction of a measurement axis by P/(2n) (wherein P is a grating pitch, n is the order of a harmonic component to be removed) in order to remove a harmonic component of the nth order. This encoder can be improved with high accuracy by removing harmonic components without increasing manufacturing costs.

Abstract: A displacement measurement system, in particular for measuring the displacement of a substrate table in a lithographic apparatus relative to a reference frame is presented. The displacement measure system includes a plurality of displacement sensors mounted to the substrate table and a target associated with each displacement sensor mounted to the reference frame.

Abstract: A position detecting device, includes a light emitting portion that includes a light emitting surface which emits light, a light receiving portion that includes a light receiving surface which receives the light from the light emitting portion, a scale that is arranged between the light emitting surface and the light receiving surface, and a cleaning member that is fixed to the scale to clean at least one of the light emitting surface and the light receiving surface.

Abstract: A scanning system of a position measuring device for photo-electric scanning of a measuring graduation, the scanning system including a support carrying measuring components, an adapter including a scanning graduation in a graduation plane and a holder that holds the support on the adapter. The holder is structured so that the support is stationarily positioned on the adapter in six degrees of freedom, but compensates thermally caused expansion of the support in relation to the adapter in a first coordinate direction and a second direction which define the graduation plane.

Abstract: An optical encoder includes an incoherent light source; a first grating, which is an amplitude grating having a first grating period, for spatial amplitude modulation of the incoherent light from the light source; a second grating, which is a phase grating having a second grating period, for spatial phase modulation of light from the first grating; a third grating, which is an amplitude grating having a third grating period, for spatial amplitude modulation of light from the second grating; and a light detecting element for detecting light from the third grating. The encoder detects relative displacement between the respective gratings. The optical transfer function from the light source to the light detecting element is enhanced, and the efficiency in utilizing light is improved.

Abstract: The X, Y and Rz positions of a mask stage are measured using two optical encoder-reading heads measuring displacements of respective grid gratings mounted on the mask stage. The grid gratings are preferably provided on cut-away portions of the mask table so as to be coplanar with the pattern on the mask itself. Measurements of the table position in the other degrees of freedom can be measured with capacitive or optical height sensors.

Abstract: A location system and a location system on a chip (LCoS) and method are described.

Abstract: An optical position-measuring device is arranged for recording the relative position of a scanning unit and a scale movable to it in at least one measuring direction. The scale is configured as a combined unit which includes at least one reflector element as well as a measuring graduation. A light source and one or more detector elements are assigned to the scanning unit. The scanning unit includes splitting device(s) which split the beam of rays, emitted by the light source, into at least two partial beams of rays in the measuring direction, which after being split, propagate in the direction of the scale.

Abstract: In a photoelectric encoder (incremental encoder and absolute encoder) having a detector that is displaceable relative to a scale having a predetermined pattern (incremental pattern and pseudorandom pattern) formed thereon, the detection range, to be simultaneously detected, of the pattern is divided in at least the detection direction, and a plurality of light-receiving systems are provided to detect each of the respective detection areas, whereby measurement of a wide detection range is enabled by using a small-sized and simple optical system and light-receiving system.

Abstract: A mark detector to detect a plurality of marks which are arranged in a predetermined cycle on a moving member, such as a photo conductor belt, a transfer belt, a paper conveyance belt, a photo conductor drum, a transfer drum, etc. especially in an image forming apparatus, has an optical head including a light source to irradiate a light beam, a beam shaping device to shape the light beam, and a photo acceptor to accept light from the marks. Light beams on the marks from the light source have different positions shifted within a half mark cycle of each other on the marks. This increases accuracy and stability of controlling a motion of the moving member.

Abstract: A displacement measuring device including a scale, and an optical readhead including an index pattern and a light receiving element is provided. A bright/dark pattern arising from a scale grating is detected by the readhead to measure displacement. In various embodiments, a magnification of the pattern is adjusted by the spacing between at least a lens element, aperture element, and detection plane of the readhead. An aperture can be designed to provide a diffraction-limited telecentric imaging configuration that filters an image of the scale grating to provide a sinusoidal intensity pattern that supports highly interpolated measurements. An aperture dimension, selected in relation to the grating pitch and other parameters, can provide a desirable combination of readhead operating characteristics including one or more of a desired depth of field; degree of spatial filtering; and optical signal power.

Abstract: An improved signal processing method and apparatus are presented for use in real-time sub-nanometer scale position measurements with the aid of probing sensors and/or beams scanning periodically undulating surfaces such as a grating and diffraction patterns generated thereby, and the like, enabling greater sub-nanometer precision, higher stage scanner movement speeds, and simultaneous high accuracy and top speed measuring capabilities.

Abstract: A scanning unit for a position measuring system for the optical scanning of a scale, the scanning unit including a light source for transmitting light in a direction toward a section of a scale and a detector for receiving light modified by the scale. A lens arrangement placed in front of the detector, the lens arrangement having a plurality of optical lenses and is used for generating a definite image of a scanned scanning area in an image field on the detector, wherein the lens arrangement optically images the scanning area reduced in surface in the image field on the detector.

Abstract: An optical encoder device for a small-sized motor has a code wheel attached to a motor shaft which extends to the exterior of the motor through a bearing accommodated in a bearing-retaining section provided on an end bell of the motor, and a board on which a photosensor module is mounted such that an optical modulation track portion of the code wheel is positioned and disposed in a gap of the photosensor module. While a spacer is sandwiched between the end bell and the board, the motor, the spacer, and the board are fixed together by soldering a pair of motor terminals to a printed wiring portion of the board. The spacer has a generally U-shaped structure so as to allow fitting in position thereof from a direction orthogonal to the motor shaft.

Abstract: A method for controlling a scanning signal of a light-electric position measuring arrangement, the method includes in a first mode of operation providing the scanning signal to a control device and the control device comparing an amplitude of the scanning signal with a predetermined level and makes a differentiation as to whether the amplitude lies above or below the predetermined level. In a second mode of operation the method includes reducing the amplitude of the scanning signal by attenuating light within a light beam path, and the reduced amplitude is compared with the predetermined level and generating an indication which is suitable for controlling a basic setting of a scanning head relative to a scale.

Abstract: A co-ordinate-measuring instrument is provided with a translumination device which includes at least one illumination body and an image processing sensor system which is provided with a lens measuring along an optical axis. In order to perform high-accuracy measurement without the necessity of placing and removing the illumination body and the sensor image processing system, the illumination body is constructed in such a way that it emits diffused light and a filter which is embodied, for example in the form of a comb, provided with through holes and arranged between the illumination body and a measured object is transparent for beams forming with the axis an angle which is less than a defined limiting angle ?.

Abstract: When a convex lens 13 comes close to 0-th order transmitted light T0 with rotation of an optical scale 11, the 0-th order transmitted light T0 derived from a light beam L emitted from a light source 15 and transmitted through a diffraction grating 12 around is converged and incident on a reference position signal detection sensor 14. At that time, a large output is obtained from the reference position signal detection sensor 14. This signal constitutes a reference position signal. On the other hand, reflective diffracted light beams La, Lb having been reflected by the diffraction grating are detected by a diffraction light detection sensor 16 after interference, so that the speed and the angle etc. of the scale 11 are detected. In this way, the reference position signal and an incremental signal are detected at the same position on the optical scale.

Abstract: A method is provided for positioning at least one target portion of a substrate with respect to a focal plane of a projection system. The method comprises performing height measurements of at least part of the substrate to generate height data, using predetermined correction heights to compute corrected height data for the height data. The method further comprises positioning the target portion of the substrate with respect to the focal plane of the projection system at least partially based on the corrected height data.

Abstract: A position-measuring device is for determining the position of two objects which are arranged displaceably with respect to each other in at least one measuring direction, and a method is for the operation of such a position-measuring device. The position-measuring device includes a measuring graduation as well as a scanning device having a light source and one or a plurality of optical and/or optoelectronic components for generating displacement-dependent position signals. A semiconductor laser having great coherence length is provided as the light source, which is operated pulsed in a single-mode operational-mode.

Abstract: At least one exemplary embodiment is directed to an optical encoder which includes a first diffraction grating having a desired optical effective aperture ratio at an appropriate gap position so as to eliminate and/or reduce high-harmonic components from the light intensity distribution of interference fringes and reduce high-order spatial frequency components overlapped on a displacement signal of the interference fringes formed by the first diffraction grating.

Abstract: Optical encoders having one or more of a number of disclosed features are disclosed. The features of the optical encoder in accordance with the present invention include a symmetrical (for example, circular) emitter; baffle between the emitter and a detector; double-dome or single-dome encapsulant; multiple detector; and multiple (at least three) data channels.

Abstract: An exemplary Two-Dimensional Optical encoder (“2-D Encoder”) described herein includes a light emitter and a light detector array. The light detector array includes at least one band of light detectors arranged on at least one diagonal of an X-Y grid having an X-axis and a Y-axis, wherein the X-axis and Y-axis are approximately orthogonal.

Abstract: An Optical Projecting Encoder (“OPE”) having an emitter module for transmitting emitted optical radiation through a mask to a moving object, and a detector module for receiving reflected optical radiation from the moving object. The reflected optical radiation from the moving object may include a predetermined image cast by the mask and a surface texture image from the moving object. The OPE may include a transmissive layer covering both the emitter module and the detector module, where the transmissive layer covering the emitter module collimates the optical radiation from the emitter module, and the transmissive layer covering the detector module concentrates the optical radiation reflected from the moving object to the detector module. The detector module may include an optical navigation sensor that continuously acquires and compares predetermined images cast by the mask and surface texture images from the moving object.

Abstract: This patent specification describes a relative position detection device and a detector for a rotary body and an image forming apparatus including the relative position detection device. The relative position detection device includes a scale comprising a pattern continuously formed by changing reflectance or transmittance and moving in a direction, a light source to irradiate the scale, a light receiving unit to read the pattern and output a signal, and a signal processing unit to process the output signal of the light receiving unit. The pattern is formed by a line pattern having regularly spaced lines perpendicular to the direction of movement of the scale, the light receiving unit is slanted with respect to the lines, and the relative position detection device detects a relative position change and speed change of the scale.

Abstract: A laser scanner is located in a fixed position to have line-of-sight access to key features of monitored objects. The scanner rapidly scans pre-programmed points corresponding to the positions of retroreflecting targets affixed to the key features of the objects. The scanner is capable of making highly detailed scans of any portion of the field of view, permitting the exact location and identity of targets to be confirmed. The security of an object is verified by determining that the cooperative target is still present and that its position has not changed. The retroreflecting targets also modulate the reflected light for purposes of returning additional information back to the location of the scanner.

Abstract: The invention describes a method of positioning an image field of, for example, an electron microscope at a specific structure in a regular grid of nominally identical structures. Such structures can, for example, be memory cells on a chip. Such memory cells nowadays have an area of, for example, less than 1 ?m2, and are arranged in a grid of 1000*1000 cells. During displacement, an error can occur that is larger than a grid distance of the structures, as a result of which the image field is adjusted to a structure other than the intended one. The displacement can be sub-divided into a large number of component displacements, whereby the error per component displacement is smaller than half a grid distance. By now determining the displacement after each component displacement, the error per component displacement can be eliminated. This method lends itself to automation, whereby the image displacements are determined with the aid of correlation techniques.

Abstract: An encoder having a code pattern on a carrier and an emitter detector module is disclosed. The code pattern includes alternating reflective and opaque regions on a carrier that includes a planar surface. The emitter-detector module includes a light source that generates light and directs a portion of the generated light at the first side of the carrier and a first detector that detects light reflected from one of the reflective regions. The reflective regions include a three-dimensional element for directing light from the light source onto the first detector. The element has a surface that is inclined at an oblique angle with respect to the planar surface. The code pattern moves with respect to the emitter-detector module. The three-dimensional element can include a reflective imaging element that images the light source onto a surface of the first detector.

Abstract: A position measurement system for measuring a position of an object is described, the system including: a first incremental measurement unit for measuring a first number of first distance steps in a distance between a reference frame and the object, wherein the first number equals a first integer value plus a first fraction, and a second incremental measurement unit for measuring a second number of second distance steps in a distance between the reference frame and the object, wherein the second number equals a second integer value plus a second fraction, wherein the position measurement system is constructed and arranged to initialize the second incremental measurement unit on the basis of the first number and the second fraction.

Abstract: A sensor head is used with a scale having a periodic optical pattern to constitute a reflective optical encoder. The sensor head includes a light source which emits a light beam applied to the scale, a photodetector which detects a light beam reflected and modulated by the scale, and a package which contains the light source and the photodetector. The package includes a box-like housing with a flat outer bottom surface and a lid member having a light-transmitting portion in at least part of it. The light source is fixed to an inner surface of the housing. The photodetector is fixed to an inner surface of the lid member.

Abstract: A system (100) and a method (500) are described for determining a two-dimensional position of a location in an image. The method (500) starts by imaging (510) a two-dimensional pattern (440). The two-dimensional pattern comprises a plurality of at least partially overlapping two-dimensional sub-patterns (410, 420, 430). The sub-patterns (410, 420, 430) repeat with different spatial periods to form the two-dimensional pattern, and the spatial period of the sub-patterns are anharmonic. A two-dimensional offset for each of the sub-patterns is then determined (540) at the location in the image formed by the imaging. The two-dimensional position is determined from said two-dimensional offsets.

Abstract: A photoelectric encoder includes a light source of an illumination light beam. The encoder also includes a movable grating which has grating lines and which is displaceable in a direction intersecting the grating lines. An index grating serves as a reference for displacement of the movable grating. A light-receiver receives the illumination light beam via the movable grating and the index grating. A modulator periodically changes a light beam outgoing from the index grating. A displacement detector detects the displacement of the movable grating based on the illumination light beam received by the light-receiver. Accordingly, a signal representing the displacement of a movable body can be accurately generated even when fluctuation of the attitude of the grating occurs.

Abstract: An optical encoder includes a mobile object having a plurality of aligned slits, a light-emitting portion for emitting light toward the mobile object, and a light-receiving portion 103 for receiving the light which has passed the mobile object. The light-receiving portion 103 produces an AC (Alternating Current) signal in an oscillation circuit 111 and outputs an input current, which is changed to an AC, from a light-emitting current output circuit 112 into the light-emitting portion.

Abstract: In an optical encoder which is designed to convert light generated from a light source into parallel light rays by using a collimator lens, thereby allowing the collimated light to radiate to gratings (a first grating, a second grating and a third grating), a diffusion means (a diffusion plate or a diffusion surface) is provided between the light source and the collimator lens to mitigate the parallelization degree of light, thereby weakening the second-order and the third-order or high-order diffraction light. Thereby, even where a light emitting diode (LED) or laser diode (LD) is used as the light source, a favorable interference output can be obtained.

Abstract: A reflection encoder is disclosed having a light emitting element in a light receiving element that are separated by a light shielding body that prevents unwanted light from entering the light receiving element. In variations of the invention, the light shielding body may be integrally formed with a mold resin portion that holds the light emitting element and light receiving element, formed by a sheet or plate, or formed using an opaque liquid resin that is poured between transparent resin bodies that encapsulate the light emitter and receiver. In operation, light radiated from the light emitting element is reflected by a code wheel and then received by a light receiving element. Other variations include varying the height at which the light receiving and detecting elements are disposed relative to the code wheel and tilting these elements towards each other so as to increase light efficiency.

Abstract: A system and method of measuring a rotational motion of a code wheel measures a rotational movement of the code wheel including an error component due to a non-rotational movement of the code wheel; measures the non-rotational movement of the code wheel; and produces an error-corrected measurement of the rotational movement of the code wheel by using the measured non-rotational movement of the code wheel to cancel the error component of the measured rotational movement of the code wheel. A signal can be produced indicating a need for maintenance when the non-rotational movement of the code wheel exceeds a threshold.

Abstract: Disclosed are remote spatial calibration apparatuses and spatial calibration methods. A first plurality of line-generating lasers is arranged for generating a first set of substantially parallel lines in a first orientation. A second plurality of line-generating lasers is arranged for generating a second set of substantially parallel lines in a second orientation. Both sets of lines are directed to project on an object and the second orientation is substantially perpendicular to the first orientation such that the lines form a matrix of lines. An imaging device is configured for obtaining an image of the object and the matrix of lines formed on the object. The spatial calibration apparatuses may be included in a housing comprising a projection face, an imaging device cavity formed in the projection face, and a plurality of laser cavities formed in the projection face.

Abstract: A photodetector for an optical encoder has plural sets of segmented photodiodes, each set of which is made by two adjoining segmented photodiodes capable of coping with a scale slit having a reference resolution. Output lines of the two adjoining segmented photodiodes are connected together in each set of the photodiodes. These output lines are connected to output lines of the corresponding segmented photodiodes in the other sets. The two adjoining segmented photodiodes function like one segmented photodiode, and thereby, the resolution of the applied scale slit is made ½ of the reference resolution. Thus, this photodetector easily copes with a scale slit having a half resolution of the reference resolution at low cost only by modification of wiring without changing any configuration of the segmented photodiodes.

Abstract: The present invention relates to a method and apparatus for determining an absolute angle and torque with an optical detection module, in which the absolute angle and the torque are determined on the basis of measurements including marked waveforms at both ends of a torsion bar, relative rotation angles at both ends of the torsion bar, and revolutions per minute of the torsion bar measured with the aid of the revolution number measurement unit.

Abstract: An optical displacement-measuring instrument of a reflection type includes a sensor head movable above a scale in a direction of measurement. This instrument is of a three-grating type that comprises a first optical grating arranged close to a light source, a second optical grating arranged on the scale, and a third optical grating arranged in a photoreceptor. A light diffuser is arranged between the light source and the first optical grating. A collimated light from the light source is diffused at the light diffuser and led to the first optical grating.

Abstract: An optical encoder includes a code strip having a first side, a second side, a first track comprising indicia thereon, and a second track comprising indicia thereon. The code strip is moveable along a displacement path with respect to the optical encoder. A light source positioned on the first side of the code strip directs light toward the code strip. A first detector element is positioned on the second side of the code strip and is generally aligned with the first track of the code strip. A second detector element is positioned on the second side of the code strip and is generally aligned with the second track of the code strip. The second detector element is also positioned so that the second detector element is located a spaced distance along the displacement path from the first detector element.

Abstract: An optical position sensing device for sensing a two-dimensional displacement, comprising a first photosensor arranged parallel to a first axis; a second photosensor arranged parallel to a second axis; wherein the first and the second axis are at an angle with respect to each other; and an encoding means which interferes with a path of light incident on the photosensors such that a pattern consisting of light and shadow is cast onto the photosensors, wherein the encoding means and the photosensors are able to move with respect to each other, resulting in modulation of light received by the photosensors, and are arranged in an arrangement such that when the encoding means moves relatively in a direction parallel to the first axis, the modulation of light received by the second photosensor is larger than the modulation of light received by the first photosensor; and when the encoding means moves relatively in a direction parallel to the second axis, the modulation of light received by the first photosensor is l

Abstract: A scanning unit for a position measuring instrument for optical scanning of a measuring graduation. The scanning unit includes a light source that emits light in a direction towards a measuring graduation that generates modified light from the emitted light. A detector that receives the modified light. A lens array, disposed upstream of the detector and including a plurality of optical lenses, that generates a defined image of a region of the measuring graduation, scanned by the emitted light, on the detector, wherein an image magnification of the lens array is greater than 0 and less than or equal to 2.

Abstract: A scanning unit for an optical position measuring device, which is suited for optically scanning a scale graduation, to produce positionally dependent scanning signals on the basis of scale graduation. The scanning unit includes a carrier element, at least one optoelectronic component, which is arranged on the carrier element, a radiation-sensitive or a radiation-emitting surface region of the component being oriented to face away from the carrier element. Provision is also made for at least one electrically conductive connector lead between the carrier element and a contacting region of the component. An at least semi-transparent cover element is arranged directly on the radiation-sensitive and/or radiation-emitting surface region of the component.