Abstract: An automated, non-invasive method for classifying, detecting, and counting micropipes contained within silicon wafers, and generally any assortment of transparent wafers. Classifying, detecting, and counting micropipes takes place through the use of a data processing algorithm that incorporates information regarding: defect size; pit signature; area of pit signature when comparing a topography, specular, or scatter images; and detecting a tail within the standard pit signature. The method of the present invention teaches the development of a topography defect map, specular defect map, and scatter defect map for a complete analysis of the surface of a particular transparent wafer. Conventional detection, classification, and counting of micropipes involve characterization of micropipes in a manual fashion and rely upon an extremely invasive form of sample preparation.

Abstract: An apparatus comprises a grouping unit dividing substrates into groups, and determining reference and non-reference substrates for each group, a measurement unit measuring a first number of points for the reference substrate, and measuring a second number, smaller than the first number, of points for the non-reference substrate, a correction value determining unit determining a first correction value to position the reference substrate, and a second correction value to position the non-reference substrate, and an exposure unit exposing the reference substrate by positioning it based on the first correction value, and exposing the non-reference substrate by positioning it based on the second correction value, the correction value determining unit determining the first correction value based on the measurement of the reference substrate, and determining the second correction value based on the measurement of the non-reference substrate, and the measurement of the reference substrate or the first correction valu

Abstract: This application relates to systems and methods for the detection of orientation features on a material web.

Abstract: A positioning apparatus for a printer. The positioning apparatus includes at least one encoder, an OPC belt, and a code strip consisting of a reference bar code region, a blank region and a normal bar code region. The OPC belt is moved relative to the encoder and has a joint region. The code strip is mounted on the OPC belt and has multiple of bar codes. The encoder is used for detecting the bar codes and generating a displacement signal representing a displacement of the OPC belt moved relative to the encoder. The blank region may adjoin the joint region. Therefore, a home position can be located precisely by the displacement signal due to the existence of the reference bar code region and blank region.

Abstract: A device comprises an imaging device, a placement element connected to the imaging device for placing a component on a substrate, as well as an optical system having an optical axis. The placement element and the imaging device can be jointly moved relative to the optical system to at least a position in which the optical axis is located between the imaging device and the placement element, wherein the position of a component supported by the placement element can be detected by means of the imaging device. The optical system is telecentric at least in an image space located near the imaging device as well as in an object space located near the placement element.

Abstract: A map of the surface of a substrate is generated at a measurement station. The substrate is then moved to where a space between a projection lens and the substrate is filled with a liquid. The substrate is then aligned using, for example, a transmission image sensor and, using the previous mapping, the substrate can be accurately exposed. Thus the mapping does not take place in a liquid environment.

Abstract: In the case of a method for sensing a marking (2) of a running web of material (3), the web of material is optically scanned by an image recording device (6). This generates in successive measuring cycles image signals which are fed to an image processing device (7). This image processing device (7) determines the positional values of the marking (2) of the web of material (3). A validity signal is generated from these positional values by applying a position-dependent weighting function and is output. This validity signal indicates whether the currently determined positional value is valid.

Abstract: The present disclosure provides an apparatus and method for the measurement of the width and radial spacing of commutator segments with respect to span. The apparatus utilizes a microprocessor and computer to record and calculate data from both a rotary encoder wheel held in contact with the commutator surface as it turns, and a fiber optic sensor that recognizes commutator segment boundaries. The commutator is rotated for one revolution plus one span to improve convenience and accuracy of the measurements. Output is provided in the form of graphs and charts that show the variation in the different spans around the commutator, and information is also provided as to each bar and insulator.

Abstract: A positional measurement system includes an electromagnetic wave source which emits an electromagnetic wave, a lens system which has a first lens surface, an electromagnetic wave shield section provided around a center axis of the first lens surface, and a second lens surface, and causes the electromagnetic wave having entered by way of the first lens surface exclusive of the electromagnetic wave shield section to exit from the second lens surface, to form an electromagnetic wave concentrated area at a position opposite the electromagnetic wave source, a receiving device which detects the electromagnetic wave concentrated area formed by the lens system, and a computing device which measures a position of the electromagnetic wave source based on information detected by the receiving device on the electromagnetic wave concentrated area.

Abstract: One or more fixed-orientation fanned laser beams and one or more displacement measurement devices to precisely measure the orientation of a payload platform are disclosed in a metrology system and method. The measurement devices may be distributed at locations across a payload platform such that displacement changes of these devices can be used to accurately determine platform pointing. Laser beam transmitters may be fixed in the same reference block to which a spacecraft attitude sensor is mounted. Fanned laser beams are transmitted from these sources to the measurement devices so that their displacements can be determined with respect to the plane of the fanned beams and thereby with respect to the spacecraft attitude sensor. Only a small number of fixed laser beams are needed to achieve precision measurements at a reduced cost, weight and power, and with increased system reliability and simplified system integration.

Abstract: A method and apparatus wherein a substrate is provided with a preformatted structure, with structural elements arranged in a matrix, wherein the matrix extends in an X-direction and Y-direction, wherein a processing head is provided, wherein a camera is provided which is connected with the processing head and which comprises at least one series of sensors arranged along a main line, wherein the camera scans the substrate and thereby provides at least one one-dimensional camera signal, wherein, for real-time determining at least the X-position and the Y-position of the structure with respect to the camera, the said main line includes an angle with the X-direction and with the Y-direction, wherein the angle is chosen such that the camera signal contains spatially separated X-position information and Y-position information and that the X-position information and the Y-position information can be separated from the sensor signal with the aid of signal processing.

Abstract: In one aspect, an optical sensor is used to detect defects, which can appear on smooth surfaces, is provided. The sensor includes a telecentric laser scanner and a detection unit. The scanner includes a laser for the approximately perpendicular illumination of a smooth surface, a scanning mirror, and a telecentric optical system for guiding illumination and detection beams the detection unit includes an optical detector system, a central diaphragm, which is concentrically positioned in the vicinity of the optical detector system in the direction toward the telecentric laser scanner, a highly sensitive photomultiplier for detecting scattered light, which emanates from defects on smooth surfaces, and a slit diaphragm arranged upstream of the photomultiplier.

Abstract: An optical scanning unit of a position measuring system for measuring a relative position of a first machine element with respect to a second machine element in a measuring direction. The optical scanning unit includes a support of a scanning grating attached to the first machine element and a detector unit attached separately to the first machine element, wherein a scanning light beam extends from the scanning grating to the detector unit as a free beam.

Abstract: A spatial information detection system is provided, which is capable of, even when detecting spatial information from a common target space by use of a plurality of detection devices, achieving accurate detection without causing interference between the detection devices. Each of the detection devices has a light emitting source for projecting light intensity-modulated with a modulation period into the target space, a photodetector for receiving light from the target space, and an evaluation portion for detecting the spatial information of the target space from a change between the light projected from the light emitting source and the light received by the photodetector. The system comprises a timing control portion for controlling the timings of projecting the lights from the light emitting sources such that a light projection period of the light emitting source of one of the detection devices does not overlap with the light projection period of the light emitting source of another detection device.

Abstract: Array scanning methods that focus on the far side and devices configured for use in the same are provided. In reading arrays according to the subject methods, an array is placed in a reading position of a scanning device so that the nominal focal plane of the scanning device is present within the array substrate at a predetermined fixed substrate thickness fraction distance from the far-side of the array, and the array is then read by the device. As such, the subject scanner devices of the present invention are configured to hold an array substrate in a reading position of the device in which the device's nominal focal plane is present within the array substrate. The subject methods and devices find use in a variety of different applications, including both genomic and proteomic applications.

Abstract: An apparatus for measuring characteristics of a substance is provided. The apparatus includes a light source to generate light to form an image. A splitter transmits the light from the light source to a first lens, which collimates the light. A second lens receives the collimated light and is adapted to oscillate with respect to the substance and adapted to transmit and focus the light to a focal region within the substance, such that the oscillation will cause the focal region to pass back and forth through the substance and its surfaces/interfaces. A sensor receives light reflected from the focal region and provides a signal indicative of characteristics of the substance at the focal region.

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: The invention provides a measuring apparatus that can efficiently analyze a three-dimensional image by simultaneously recording a circular streak image and a straight-line streak image at a measured point, even when a large number of circular streak images are present. A measuring apparatus includes: a 3CCD camera; a cubic beam splitter that combines optical images incident from plural routes; a mirror that shifts an image focusing position of an optical image at a measured point by a predetermined distance; a coloring unit that applies a predetermined color to an optical image incident to a route of the beam splitter; a motor that rotates the beam splitter and the mirror in a direction of an arrowhead; and a PC that calculates a three-dimensional position of the measured point based on the optical image recorded by a camera.

Abstract: An exposure method for exposing a pattern of a reticle onto a plate, via a projection optical system, while synchronously scanning the reticle and the plate. The exposure method includes the steps of (a) measuring before exposing, the measuring step including (i) a first substep of obtaining surface form data that shows a surface form of the reticle, and (ii) a second substep of detecting a measurement position having an abnormal measurement result as an error measurement position among measurement positions, to measure the surface form of the reticle based on a measurement result of the obtaining substep, and (b) controlling synchronous scanning of the reticle and the plate using the measurement result of the detecting substep, except for the detecting result of the error measurement position.

Abstract: A position detecting apparatus includes a first illuminating unit that radiates light onto a substrate in a direction substantially parallel to the front and the rear surfaces of the substrate from the direction of a lateral face of the substrate; a second illuminating unit that radiates light onto the front surface of the substrate, in a direction substantially perpendicular to the front surface of the substrate; an image pickup unit that takes an image of the substrate from a rear surface side thereof; and an edge-position detecting unit that detects an edge position of the substrate, based on a first image that is taken while the light is being radiated from the first illuminating unit and a second image that is taken while the light is being radiated from the second illuminating unit, respectively.

Abstract: An optical scanning device is provided. The optical scanning device an excitation light source that is operable to illuminate the object to be scanned. An image detector is operable to detect excited emission rays through illumination of the object to be scanned by the excitation light source and imaging optics that dictate a focal distance. The image detector detects a scan image of the emission radiation of the object to be scanned with the highest level of image sharpness if the focal distance is maintained. A control device includes a distance sensor through which a distance between an optical scanning device and the object to be scanned can be measured, wherein maintenance of the focal distance as the function of the measured distance can be checked by the control device.

Abstract: An integrated display and input device including a first pixel array operative to provide a visually sensible output, a second pixel array operative to sense at least a position of an object with respect to the first pixel array and circuitry receiving an output from the second pixel array and providing a non-imagewise input to utilization circuitry.

Abstract: A method of determining position information, the method having detecting—along a first direction—a value of a geometry parameter related to a structure formed on and/or in a substrate, and determining—with regard to a second direction—a value of a position parameter based on the detected value of the geometry parameter and a predetermined relationship between the geometry parameter and the position parameter.

Abstract: A collar, a system and a method detect a mark on a rod within an interior of the collar. The mark and the rod move from a first position to a second position within an interior of the collar between a first end and a second end of the collar. A light emitter and/or a light detector is connected to the collar for determining the first position and/or the second position of the mark and/or of the rod within the interior of the collar. An exterior surface of the rod and/or a mark on the rod absorb an amount of light emitted from the light emitter within the interior of the collar. The light detector measures and/or detects an intensity of light within the interior of the collar which is not be absorbed by the mark and/or by the exterior surface of the rod.

Abstract: Provided is a paper detection apparatus for detecting the size of a sheet of paper transferred along a paper transfer path, which includes a light source and an optical sensor. A plurality of light emitting optical fibers are located at a first side of the paper transfer path and receive light radiated by the light source and emit the received light to a plurality of positions in a widthwise direction of the paper. A plurality of light receiving optical fibers are located at a second side of the paper transfer path and guide the light emitted by the light emitting optical fibers toward the optical sensor. A determination unit detects the size of the paper based on the amount of light detected by the optical sensor.

Abstract: A positioning apparatus for a printer is provided. The positioning apparatus includes at least one encoder, an OPC belt, and a code strip consisting of a reference bar code region, a blank region and normal bar code region. The OPC belt is moved relatively to the encoder and has a joint region. The code strip is mounted on the OPC belt and has a plurality of bar codes. The encoder is used for detecting the bar codes and generating a displacement signal representing a displacement of the OPC belt moved relatively to the encoder. The blank region may be adjoined the joint region. Therefore, a home position can be located precisely by the displacement signal due to the existence of the reference bar code region and blank region. Moreover, a positioning method for a printer is also disclosed.

Abstract: To transmit energy without direct mechanical or electrical contact, a transmitter unit emits a laser beam onto a radiation receiver of a receiver unit including a photovoltaic cell arrangement surrounded by a ring-shaped reflector. A portion of the laser beam is reflected from the reflector back to the transmitter unit, where the received reflected signal is evaluated to determine the position of the laser beam impinging on the radiation receiver. The transmitter unit deflects the laser beam as necessary to impinge directly on the photovoltaic cell arrangement and track any relative motion of the receiver unit. The receiver unit orients the radiation receiver to optimize the energy reception. The position of the laser beam is modulated and the resulting variation of the reflected signal is evaluated to determine therefrom the position of the laser beam on the radiation receiver.

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: Disclosed is a sealant dispenser for more precisely dispensing a sealant onto a substrate, and a control method thereof. The sealant dispenser includes a stage on which a substrate is mounted; a nozzle for dispensing a sealant while making a relative motion with the substrate; a syringe coupled to the nozzle, for storing the sealant; and a distance sensor installed on both sides of a lower portion of the syringe, for measuring a vertical distance between a principal plane of the substrate and an outlet of the nozzle. According to the principles of the present invention, because the nozzle and the syringe have substantially the same central axis, the response speed of the sealant to be dispensed is increased and the start point and the end point of paste pattern are more precisely dispensed. Also, by minimizing the distance between the nozzle and a measuring point provided by the distance sensor, it becomes possible to dispense the sealant at higher precision.

Abstract: Apparatus for optically measuring a remote object comprises at least one source for projecting a plurality of discrete zones of electromagnetic radiation (for example laser spots) along a projection plane. Imaging apparatus images a plurality of reflections from the remote object. By spatially offsetting the imaging apparatus from the projection plane, easier discrimination and identification of the reflections is made possible.

Abstract: A method and apparatus for protecting an optical transmission measurement when sensing transparent materials. Sensing apparatus located in a housing directs a light beam at an upward angle to a sheet of transparent material and detects downward surface reflections of the beam from the transparent material. The light beam and the reflections pass through a transparent protective layer on the housing. A flow of clean air is passed between the protective layer and the transparent material to remove particles and liquid from the protective layer and from the space between the protective layer and the transparent material. Preferably, the protective layer is either made from a hydrophobic material or has a hydrophobic surface coating to facilitate blowing liquid and particles from the surface.

Abstract: A method of measuring dimensional changes in a transparent substrate includes forming an array of reference markers on a reference plate, forming an array of substrate markers on the transparent substrate, stacking the reference plate and transparent substrate such that the reference markers and substrate markers overlap, measuring coordinates of the substrate markers relative to coordinates of the reference markers before and after processing the transparent substrate, and determining dimensional changes in the transparent substrate from the difference between the measured relative coordinates of the substrate markers before and after processing the transparent substrate.

Abstract: A transmitter formed of two or more light-emitting sections such as LEDs, which are physically arranged in a predetermined manner, is disposed in the real world object, and each light-emitting section transmits data by flashing at a flashing pattern representing the transmission data of a predetermined bit length. A receiver, on the other hand, includes a photoreceiving section formed from a two-dimensional photoreceiving surface, decodes the transmission data on the basis of the photoreceived flashing pattern, and recognizes the spatial information of an object on the basis of the flashing position on the two-dimensional photoreceiving surface. Therefore, information, such as an ID, can be obtained from the object in the real world, and also, the spatial position of the object can be recognized at the same time.

Abstract: In a circuit arrangement for analyzing a clocked signal reflected from an object, particularly an optical signal, wherein at least one radiation emitter which, for providing the clocked signal, is connected to a clocking signal generator, and at least one radiation receiver which receives radiation pulses emitted by the radiation emitter and reflected from the object, and a comparator by which the output signal pulses of the radiation are compared with reference pulses whose amplitudes depend on output signals of the comparator, are provided, the reference signal pulses occur concurrently with the radiation impulses received by the radiation receiver and the impulses received by the radiation receiver are compensated for each by a respective internal reference impulse before their analysis in the circuit arrangement.

Abstract: A digital camera receives position information from GPS satellites for detecting camera position when capturing an image. Additional information, which is composed of the camera position, camera azimuth and focal distance of the taking lens, is added to image data of the captured image as tag and recorded in an image file. When the captured image is reproduced, the map image generated according to the additional information is displayed below the captured image, covering an area from the image capture point toward the subject in the captured image. Field view lines and map symbols indicating the subjects are displayed in the map image. Further, the map image includes the extension line which passes the map symbol and is extended to the subject in the captured image for showing the correspondence between the map symbol and the subject.

Abstract: A plurality of optical beacons that emit light in respective light emitting patterns containing an ID code are distributed and installed in a space in which of a mobile body are moved. The mobile body is provided with a detection unit. The detection unit identifies at least three optical beacons according to the ID codes of the lights emitted according to the optical beacons and detects the direction of light emitted according to each of the identified optical beacons. Then, it detects the position of the mobile body according to the outcome of detection.

Abstract: Various edge detection arrangements are disclosed, including an edge detection method and arrangement that utilizes outputs of commonly illuminated reference and edge sensors as the inputs for a comparator. The reference sensor is configured to have a wide field of view and the edge sensor is configured to have a narrow, high gain, field of view. Therefore, the reference sensor has a broad signal response to an edge passage and the edge sensor a steep and narrow signal response. When the two signals are biased to cross each other, the comparator output changes state, indicating passage of an edge. Because the reference sensor provides a base signal level directly related to the real time illumination level that the edge sensor also receives, the reference sensor provides a switch point along the transition ramp of the edge sensor that integrates a majority of the random error sources.

Abstract: A trackball in one embodiment includes a PCB including an aperture, a socket including upper and lower chambers communicated with each other, rollers disposed around bottom of the upper chamber, a ball rotatably supported by the rollers, a ring cover secured to the socket, a light guide plate mounted between the socket and the PCB and including an inclined light guide tube and an optical element; and an optical assembly mounted under the aperture and including a light source (e.g., LED) for emitting light through the light guide tube prior to impinging on the ball, and a photosensor. Rolling the ball will reflect the light from the ball through the optical element to be received by the photosensor such that the rotational movement of the ball can convert into a digital signal useable to move a cursor a corresponding distance and direction on a display.

Abstract: The orientation of a machine 2 relative to a work-piece 10 is manually controlled by means of an alignment device 4. The device 4 includes a light source 24 rigidly attached to a foot 12 that is resiliently movably attached to the main body 18 of the device. The body 18 of the device 4 houses a light detector 26 for detecting a light beam from the light source 24, the position of the region on the detector 26 illuminated by the beam depending on the orientation of the machine 2 relative to the work-piece 10. The operator is provided with feedback on whether the machine 2 is correctly aligned with a target orientation (usually perpendicular to the surface) and concerning the direction of corrective movement required, if any.

Abstract: A measuring system includes a coordinate measuring machine for driving a scanning probe and a host computer. The host computer includes a compensation table (53) and a profile analysis unit (54). The compensation table stores, as compensation data, compensation coefficients to correct counter values of a probe counter (415), and compensation radiuses “r” to the workpiece surface concerning central coordinate values of a contact portion, for respective contact directions. The profile analysis unit has a contact direction calculation unit (542), a compensation data selection unit (543), a compensation calculation unit (544). The contact direction calculation unit calculates the contact direction along which the scanning probe comes into contact with a workpiece W, and the compensation data selection unit selects compensation data set up in the compensation table based on thus calculated contact direction.

Abstract: There is provided a position detecting method for detecting a position of an object, on which an alignment mark including plural mark elements is formed. The method includes the steps of obtaining positional information indicative of each position of the plural mark elements, selecting positional information that has predetermined precision among plural pieces of positional information obtained by the obtaining step, and calculating the position of the object using the positional information that has the predetermined precision selected by the selecting step.

Abstract: The invention provides a surface profile measurement device for use on rigid or semi-rigid substrates, such as floors. The device includes (a) a beam; (b) at least one beam support mounted on the beam; (c) a sensor assembly slidably connected to said beam and adapted for measuring the distance to the surface; and (d) a transducer assembly adapted for measuring the position of said sensor assembly along said beam.

Abstract: A method and apparatus for dynamically focusing an imaging mechanism on a moving target surface having a variable geometry is herein disclosed. Apparatus for focusing an imaging mechanism may include an objective, a prism, or another optical device that forms part of an optical train of an imaging mechanism, a sensor for measuring a distance to the target surface, and a mechanism for modifying the depth of focus of the objective, prism or other optical device. Data from the sensor may be used to create a predictive model of the target surface. Data from the sensor is also used to fit or correlate the generated model to an exemplary target. Data from the correlated model is used to drive the mechanism for modifying the depth of focus of the objective, prism, or other optical device to maintain the surface of the exemplary target in focus.

Abstract: A tightly adhering state between an elastically deformable first substrate deformed and made to tightly adhere to an elastically undeformable second substrate is detected by way of displacement of the light receiving position of a light receiving section adapted to receive light emitted from a light source for the first substrate and reflected by the first substrate.

Abstract: A method and system position a laser beam spot relative to a semiconductor substrate having structures on or within the semiconductor substrate to be selectively processed by delivering a processing laser beam to a processing laser beam spot. The method generates a metrology laser beam and propagates the metrology laser beam along a propagation path to a metrology laser beam spot on or near a structure to be selectively processed. The method detects a reflection of the metrology laser beam from the structure, thereby generating a reflection signal, and determining, based on the reflection signal, a position of the metrology laser beam spot relative to the structure.

Abstract: In the optical distance measuring device of the invention, a second optical path is formed by a transparent resin formed in a region where a light emitting element and a second light receiving part are connected directly to each other. As the temperature increases, the length of the optical path increases while its refractive index decreases, so that the optical path length itself becomes generally constant. Therefore, the length of the second optical path can be kept generally constant independently of temperature. Further, a first light receiving part for a first optical path and a second light receiving part for the second optical path 18 are formed in one identical light receiving element. Therefore, characteristic variations of the first light receiving part and the second light receiving part due to temperature can be reduced. This optical distance measuring device can achieve high distance measuring accuracy even under environments of intense temperature changes.

Abstract: Various methods and systems measure, determine, or align a position of a laser beam spot relative to a semiconductor substrate having structures on or within the semiconductor substrate to be selectively processed by delivering a processing laser beam to a processing laser beam spot. A metrology laser beam spot is directed to one or more of those structures to be selectively processed (e.g., laser-severable conductive links), and reflections of the metrology laser beam off of those structures to be selectively processed are detected to perform the measurement, determination, or alignment. The processing laser beam can then be accurately directed onto those structures to process them on a selective basis. The various methods and systems thus utilize those structures themselves—rather than relying exclusively on dedicated alignment markers—to perform the measurement, determination, or alignment.

Abstract: A logistic station comprises a plurality of objects having a first status and a second status and a detection device used for detecting the status of the objects. The detection device comprises a pallet having a plurality of first supporting portions and a first sensor. The objects are detachably disposed on the first supporting portions of the pallet. A first reference position and a first predetermined position are configured in the pallet with respect to the first supporting portions thereof. The first sensor transmits a first signal to the first predetermined position to detect whether objects having the second status.

Abstract: A wireless substrate-like sensor is provided to facilitate alignment and calibration of semiconductor processing systems. The wireless substrate-like sensor includes an optical image acquisition system that acquires one or more images of targets placed within the semiconductor processing system. Analysis of images of the targets obtained by the wireless substrate-like sensor provides position and/or orientation information in at least three degrees of freedom. An additional target is affixed to a known location within the semiconductor processing system such that imaging the reference position with the wireless substrate-like sensor allows the measurement and compensation for pick-up errors.

Abstract: A position-measuring device includes: a measuring graduation provided on a material measure going around in ring-like fashion; a scanning unit for optically scanning the measuring graduation using electromagnetic radiation; a scanning plate with a periodic scanning graduation which is arranged in the beam path of the electromagnetic radiation used for scanning the measuring graduation, so that the radiation interacts both with the scanning graduation and with the measuring graduation; and a detector of the scanning unit, the detector surface of which is used for detecting the electromagnetic radiation after interaction with the scanning graduation and the measuring graduation and which is arranged with a period (PD) for detecting electromagnetic radiation in the form of a stripe pattern. The period PM of the measuring graduation and the period PA of the scanning graduation may be coordinated so that 1/(1/PA?1/PM)<PD.