Abstract: A machine vision inspection system acquires a plurality of images of a workpiece region of interest at various focus heights, and determines a Z-height (e.g., the best focus height) for the region of interest based on a focus peak determining data set for the region of interest. The focus peak determining data set is derived from the plurality of images. The machine vision inspection system also determines Z-height quality meta-data based on data derived from the plurality of images (e.g., based on the focus peak determining data set), and associates the Z-height quality meta-data with the corresponding Z-heights. The Z-height quality meta-data are usable to establish weighting factors that are used in association with the corresponding best focus Z-heights in subsequent operations that fit a workpiece surface representation to a plurality of the best focus Z-heights.

Abstract: An apparatus for determining surface topology of a portion of a three-dimensional structure is provided, that includes a probing member, an illumination unit, a light focusing optics, a translation mechanism, a detector and a processor.

Abstract: A metrology tool (1) for measuring the positions of structures (32) on a mask surface (31) is disclosed. On a measuring stage (33) a reflector (36) selective with respect to the wavelength is provided, which essentially reflects light within a first wavelength region emitted from a first illumination device (10), and essentially does not reflect light within a second wavelength region emitted from a second illumination device (20). The reflector (36) selective with respect to the wavelength preferentially is a dichroic mirror. By detecting the light within the first wavelength region reflected by the reflector (36) the position of predefined sections of outer edges (37) of the mask is determined. The light from the second wavelength region is used for determining the coordinates of structures on the mask.

Abstract: The invention is directed to a method for illuminating an object and projecting its image on a ground glass screen. Optical comparators conventionally use incandescent illumination, either mercury arc or halogen. The use of an array of high intensity LED devices, provides many options for packaging the required optical components used in comparators.

Abstract: Methods and systems for three-dimensionally imaging an apical dome located at the cotyledon end of a plant embryo are provided. Three-dimensional information of an apical dome can be obtained by scanning the apical dome at varying focal planes along an axis of the embryo, or by using multiple cameras arranged in a confocal manner to image the apical dome. It can also be obtained by irradiating the apical dome with polychromatic light, wherein light beams of multiple wavelengths are focused at multiple focal planes along the axis of the embryo so that the dome's height information can be obtained based on the wavelength of the light precisely focused and reflected at each surface point of the dome. The three-dimensional information is used to ascertain various morphological features (e.g., size, shape, texture, etc.) of the apical dome, which are in turn used to assess the embryo's germinant vigor.

Abstract: Methods for providing compensation for non-uniform response of a light source and wavelength detector subsystem of a chromatic point sensor (CPS) are provided. Light from the light source is input into an optical path that bypasses the measurement path through a CPS optical pen and provides the bypass light to the wavelength detector to provide a raw intensity profile distributed over the pixels of detector. The resulting set of raw intensity profile signals are analyzed to determine a set of error compensation factors for wavelength-dependent intensity variations that occur in the raw intensity profile signals. Later, the error compensation factors may be applied to reduce distortions and asymmetries that may otherwise occur in the shape of the signals in the peak region of CPS distance measurement profile signal data. The disclosed methods may provide enhanced accuracy, robustness, field-testing, and interchangeability for CPS components, in various embodiments.

Abstract: A probe microscope includes a cantilever having a probe for contact with an object, first and second displacement detection optical systems, and an object lens. The first displacement detection optical system includes a first light source and a first displacement detecting section that detects displacement of the cantilever. The second displacement detection optical system includes a second light source and a second displacement detecting section that detects displacement of the object. The object lens is provided between the cantilever and the first light source and between the cantilever and the second light source. The object lens has a focal position for the light that is emitted from the first light source and has a first wavelength at the position of the cantilever and has a focal position for the light that is emitted from the second light source and has a second wavelength at the position of the object.

Abstract: A scatterometer has a focus sensor arranged to detect whether the target being measured is in a correct focal plane. A modulation is applied to a component of the focus sensor or the scatterometer such that a defocus as measured by the focus sensor varies according to a certain function. From knowledge of the modulation, the gain of the sensor can be calibrated.

Abstract: A 3D shape measurement apparatus for measuring a 3D shape of an object existing on a measurement area, comprising, a pattern projection unit for projecting a pattern having a periodicity onto the measurement area, and a capturing unit for capturing an image of the area where the pattern is projected, wherein the measurement area is specified by a reference plane, a projection area of the pattern projection unit, and a capturing area of the capturing unit, and the pattern projection unit projects the pattern to be focused on the reference plane. The apparatus further comprises a first calculation unit for calculating phase information of a pattern of the captured image, a second calculation unit for calculating defocus amounts of the pattern in the captured image, and a third calculation unit for calculating a 3D shape of the object based on the phase information and the defocus amounts.

Abstract: Methods and apparatus relating to the inspection of photomasks are described. In an embodiment, an inspection tool may be automatically focused on a reticle utilizing various topographic mapping techniques. Other embodiments are also described.

Abstract: Methods for providing compensation for non-uniform response of a light source and wavelength detector subsystem of a chromatic point sensor (CPS) are provided. Light from the light source is input into an optical path that bypasses the measurement path through a CPS optical pen and provides the bypass light to the wavelength detector to provide a raw intensity profile distributed over the pixels of detector. The resulting set of raw intensity profile signals are analyzed to determine a set of error compensation factors for wavelength-dependent intensity variations that occur in the raw intensity profile signals. Later, the error compensation factors may be applied to reduce distortions and asymmetries that may otherwise occur in the shape of the signals in the peak region of CPS distance measurement profile signal data. The disclosed methods may provide enhanced accuracy, robustness, field-testing, and interchangeability for CPS components, in various embodiments.

Abstract: This is an optical three-dimensional measurement device provided with observation illumination light for illuminating an observation specimen, an object lens for collecting the observation light on the observation specimen and a display unit for displaying an observation image and its measurement result that are obtained via the object lens. The optical three-dimensional measurement device comprises a filter process determination unit for determining a first filter process on the basis of observation conditions used when taking in a three-dimensional image of the observation specimen and a filter process unit for applying the first filter process determined by the filter process determination unit to the measurement image or the measurement result.

Abstract: An apparatus for determining surface topology of a portion (26) of a three-dimensional structure is provided, that includes a probing member, an illumination unit, a light focusing optics, a translation mechanism, a detector and a processor.

Abstract: A fiber interface configuration for a chromatic point sensor optical pen is provided wherein a detector aperture element provides an aperture that is smaller than the light-transmitting core diameter of an optical fiber that is connected to the optical pen. The detector aperture element is fixed relative to the chromatically dispersive optics of the optical pen, the optical fiber abuts the aperture element, and the optical fiber core is aligned to the aperture. The aperture element and the end of the fiber may be inclined relative to the axis of the fiber, to deflect spurious reflections away from the optical signal path. The configuration provides high measuring resolution without using a tapered optical fiber, and provides interchangeability of the optical fiber connected to the optical pen.

Abstract: The present invention discloses methods and systems for improved focusing of imaging systems for the acquisition of high-quality focused tissue image data. A light emitter (L) aims a focusing light beam (FLB) towards an object of interest (O) so that the focusing light beam (FLB) is at an angle relative to the optical axis (OA) of the imager (I). If the object of interest (O) is out of focus, the focusing light spot (FLS) will appear above or below the focal point in the image (I). The pixel difference between the center of the focusing light spot (FLS) and the focal point indicates the range adjustment value. The range between the imager (I) and the object of interest (O) can then be adjusted according to the range adjustment value using a lookup table or calculations.

Abstract: A method and system are provided which can easily determine relative positions and postures of a three-dimensional measurement device and an object when the measurement device is used to measure the object using a manipulator. The method includes fixing one of the measurement device and the object, supporting the other at a support point with the manipulator so that a position and support posture of the other can be changed, conducting first measurement with the support point being set to first position and posture, changing the support point to second position and posture so that the second position is a position where the posture is changed, about a reference position within a measurable area of the measurement device in the first measurement, to an opposite side by a degree equal to a portion corresponding to a change from the first posture to the second posture, and conducting second measurement.

Abstract: A method for analyzing probe mark, the method includes: scanning the probe mark by multiple spots; evaluating a probe mark characteristic in response to detection signals generated by multiple sensors of the chromatic confocal system that is characterized by a sub-micron axial resolution.

Abstract: A method of using an in-situ aerial image sensor array is disclosed to separate and remove the focal plane variations caused by the image sensor array non-flatness and/or by the exposure tool by collecting sensor image data at various nominal focal planes and by determining best focus at each sampling location by analysis of the through-focus data. In various embodiments, the method provides accurate image data at best focus anywhere in the exposure field, image data covering an exposure-dose based process window area, and a map of effective focal plane distortions. The focus map can be separated into contributions from the exposure tool and contributions due to topography of the image sensor array by suitable calibration or self-calibration procedures. The basic method enables a wide range of applications, including for example qualification testing, process monitoring, and process control by deriving optimum process corrections from analysis of the image sensor data.

Abstract: An apparatus for determining surface topology of a portion of a three-dimensional structure is provided, that includes a probing member, an illumination unit, a light focusing optics, a translation mechanism, a detector and a processor.

Abstract: An apparatus for determining surface topology of a portion of a three-dimensional structure is provided, that includes a probing member, an illumination unit, a light focusing optics, a translation mechanism, a detector and a processor.

Abstract: A three-dimensional profile inspecting apparatus includes at least two optical inspecting apparatuses and a tilt angle adjusting mechanism. The tilt angle adjusting mechanism is equipped with the at least two optical inspecting apparatuses so as to adjust the tilt angles of the at least two optical inspecting apparatuses. When the tilt angles of the optical inspecting apparatuses are changed, the focuses of the optical inspecting apparatuses remain at a single position and a subject to be inspected is within the fields of view of the optical inspecting apparatuses. The three-dimensional profile of the subject can be obtained by building the images collected by the two optical inspecting apparatuses.

Abstract: A device for determining the surface topology and associated color of a structure, such as a teeth segment, includes a scanner for providing depth data for points along a two-dimensional array substantially orthogonal to the depth direction, and an image acquisition means for providing color data for each of the points of the array, while the spatial disposition of the device with respect to the structure is maintained substantially unchanged. A processor combines the color data and depth data for each point in the array, thereby providing a three-dimensional color virtual model of the surface of the structure. A corresponding method for determining the surface topology and associated color of a structure is also provided.

Abstract: A three-dimensional shape measuring system is provided with a measuring unit having a three-dimensional measurement range and adapted to measure the three-dimensional shape of a measurement object in a noncontact manner, a measurement range shifting unit for shifting the position of the measurement range of the measuring unit, a shape calculating unit for calculating the overall three-dimensional shape of the measurement object from a plurality of measurement data obtained by shifting the measurement range relative to the measurement object, and a judging unit for setting judgment areas in specified peripheral areas within the measurement range and judging the presence or absence of any unmeasured area of the measurement object outside the measurement range based on measurement data corresponding to the judgment areas.

Abstract: A method and apparatus for assessing a height of a specimen includes an electron beam unit having an electron beam source, lenses, a table for setting a specimen and controllable in a height direction, and a detector, and a height detection system for detecting height of the specimen set on the table while the specimen is irradiated by an electron beam. The height detection system further includes an illumination system, a collection system, first and second detectors, a device configured to receive output signals from the first and second detectors while the specimen is irradiated by the electron beam and to generate a comparison signal from the output signals, wherein the comparison signal is responsive to the height of the specimen.

Abstract: An apparatus and a method are proposed for measuring displacement, surface profile and roughness of a moving object or an inner radius of a hollow cylinder. The apparatus includes a light emitting unit, a light dispersing unit for receiving light from the light emitting unit and focusing rays with different wavelengths into different focal points with different intervals, and a wavelength measuring unit for measuring wavelengths of the rays. When the moving object is moving within a dispersing range of the focal points, the rays with different wavelengths are reflected or scattered, and the displacement of the moving object is learned from variation of the wavelengths being measured by the wavelength measuring unit. Given that a reflecting component is disposed in the centre of an inner circle of the hollow cylinder, the inner radius of the hollow cylinder can be measured by the principle of the apparatus for measuring displacement.

Abstract: An apparatus for determining surface topology of a portion (26) of a three-dimensional structure is provided, that includes a probing member, an illumination unit, a light focusing optics, a translation mechanism, a detector and a processor.

Abstract: Measurement of a profile of a scatterometry object on top of one or more product layers on a substrate is disclosed. To prevent an unknown parameters of one or more product layers having an effect on the measurement of the object profile, the thickness of the one or more product layers is measured prior to measuring the profile of the scatterometry object on the layer(s). In an embodiment, each of a plurality of product layers is measured as it is exposed so that only the degree of freedom of the most recently exposed product layer is unknown at each measurement step. When each of a plurality of product layers has been measured, and a scatterometry object is placed at the top of the layers, only the degrees of freedom of that scatterometry object should be unknown and only the profile of the object should need to be measured.

Abstract: The profile of a single feature formed on a wafer can be determined by obtaining an optical signature of the single feature using a beam of light focused on the single feature. The obtained optical signature can then be compared to a set of simulated optical signatures, where each simulated optical signature corresponds to a hypothetical profile of the single feature and is modeled based on the hypothetical profile.

Abstract: An image is processed by a sensed-feature-based classifier to generate a list of objects assigned to classes. The most prominent objects (those objects whose classification is most likely reliable) are selected for range estimation and interpolation. Based on the range estimation and interpolation, the sensed features are converted to physical features for each object. Next, that subset of objects is then run through a physical-feature-based classifier that re-classifies the objects. Next, the objects and their range estimates are re-run through the processes of range estimation and interpolation, sensed-feature-to-physical-feature conversion, and physical-feature-based classification iteratively to continuously increase the reliability of the classification as well as the range estimation. The iterations are halted when the reliability reaches a predetermined confidence threshold.

Abstract: An apparatus for determining surface topology of a portion (26) of a three-dimensional structure is provided, that includes a probing member, an illumination unit, a light focusing optics, a translation mechanism, a detector and a processor.

Abstract: A device for determining the surface topology and associated color of a structure, such as a teeth segment, includes a scanner for providing depth data for points along a two-dimensional array substantially orthogonal to the depth direction, and an image acquisition means for providing color data for each of the points of the array, while the spatial disposition of the device with respect to the structure is maintained substantially unchanged. A processor combines the color data and depth data for each point in the array, thereby providing a three-dimensional color virtual model of the surface of the structure. A corresponding method for determining the surface topology and associated color of a structure is also provided.

Abstract: A level detection apparatus includes an illumination slit in which a rectangular first opening which causes illumination light to pass is formed, an optical system configured to illuminate a target object surface by illumination light passing through the illumination slit and focuses reflected light from the target object surface, first and second detection slits which are arranged in front of and in back of a focal point and in each of which a second opening is formed such that a short side of a rectangle is shorter than a short side of a illumination slit image formed by the illumination slit and a long side of the rectangle is larger than a long side of the illumination slit image, first and second light amount sensors configured to detect amounts of light of the reflected lights passing through the first and second detection slits, and a calculating unit configured to calculate a level of the target object surface based on outputs from the first and second light amount sensors.

Abstract: A device for optically examining an object includes a lens, an object stage for receiving the object, and an image-recording apparatus for recording a series of individual images of the object in a number of planes. A piezo-controlled apparatus is provided for adjusting the distance between the lens and the object, and an image-generating apparatus is provided for generating a multifocus image from the series of individual images.

Abstract: A system and a method for thickness measurement that comprises providing a first confocal microscope, emitting a first light beam from the first confocal microscope in a first direction, focusing the first beam at a first focal plane, providing a second confocal microscope, emitting a second light beam from the second confocal microscope in a second direction substantially opposed to the first direction, focusing the second beam at a second focal plane, and adjusting the relative position of the first and second microscopes by overlapping the first and second focal planes.

Abstract: A system for the measurement of high aspect ratio trenches. The preferred embodiment consists of three elements: a) an integrated microscope and optical height sensor, b) an axially dispersive, afocal lens system, which is included in the optical height sensor, and c) an algorithm for processing the optical height sensor data to produce the depth of the high aspect ratio trench. The present invention combines a traditional imaging microscope with a chromatic confocal, single point, height sensor. This combination instantaneously provides an image of the object and the height value at one point in the image. No mechanical movement is necessary anywhere in the system to achieve that result. The chromatic confocal height sensor is integrated with a traditional microscope through the use of separate wavelength bands such as a wavelength band in the visible part of the spectrum, and a wavelength band in the infrared or ultraviolet part of the spectrum.

Abstract: A range/speed finder can be incorporated into a personal electronic device. In one example, a personal electronic device includes an automatic focus system adapted to focus an image of an object and a processor in communication with the automatic focus system adapted to detect a distance of the object using the automatic focus system. The processor can be adapted to detect a speed of the object and/or a dimension of the object using the automatic focus system. Methods and systems for determining a distance, a dimension, and/or a speed of the object relative to the personal electronic device are also provided.

Abstract: Determining surface topology of a portion (26) of a three-dimensional structure is provided. An array of incident light beams (36) passing through a focusing optics (42) and a probing face is shone on said portion. The focusing optics defines one or more focal planes forward the probing face in a position which can be changed (72) by the focusing optics. The beams generate illuminated spots (t2) on the structure and the intensity of returning light rays propagating in an optical path opposite to that of the incident light rays is measured (60) at various positions of the focal plane(s). By determining spot-specific positions yielding a maximum intensity of the returned light beams, data is generated which is representative of said topology.

Abstract: An apparatus and a method are proposed for measuring displacement, surface profile and roughness of a moving object or an inner radius of a hollow cylinder. The apparatus includes a light emitting unit, a light dispersing unit for receiving light from the light emitting unit and focusing rays with different wavelengths into different focal points with different intervals, and a wavelength measuring unit for measuring wavelengths of the rays. When the moving object is moving within a dispersing range of the focal points, the rays with different wavelengths are reflected or scattered, and the displacement of the moving object is learned from variation of the wavelengths being measured by the wavelength measuring unit. Given that a reflecting component is disposed in the centre of an inner circle of the hollow cylinder, the inner radius of the hollow cylinder can be measured by the principle of the apparatus for measuring displacement.

Abstract: The focus of an optical system (20) can be determined in a reliable and accurate way by arranging a first and second test object (62,64) having a periodic structure at different sides of the focal plane (66) of the optical system and determining the difference in modulation depth of the images formed on different areas (32,34) of a radiation-sensitive detection system (30).

Abstract: An operation of projecting slit light onto an object to be measured and receiving light reflected thereon, and an operation of acquiring a two-dimensional image concerning the object to be measured are repeated a certain number of times by changing a focal length. An imaging contrast is calculated with respect to each of areas on the two-dimensional images acquired at the different focal lengths. A high contrast area where the imaging contrast exceeds a predetermined threshold value is extracted with respect to each of the two-dimensional images acquired at the different focal lengths. Distance information concerning the respective areas is acquired by performing triangulation with respect to each of the high contrast areas. Position adjustment of measurement dimensions is performed in such a manner that the areas are included in the measurement dimensions having the predetermined measurement depth, based on the distance information.

Abstract: An apparatus for measuring the height of a work held by a chuck table provided in a machining apparatus, including: a white light source for emitting a white beam of light; a chromatic aberration lens for condensing the white beam emitted from the white light source; a beam splitter which is disposed between the white light source and the chromatic aberration lens and by which a reflected beam of the white beam irradiating the work therewith is split; a first condenser lens for condensing the reflected beam split by the beam splitter; a diffraction grating by which the reflected beam condensed by the first condenser lens is converted into a diffracted beam; a second condenser lens for condensing the diffracted beam diffracted by the diffraction grating; and a wavelength detecting unit for detecting the wavelength of the diffracted beam condensed by the second condenser lens.

Abstract: A displacement measurement sensor using the confocal principle with an optical fiber for measuring small changes in distance to a specular target surface comprises a monochromatic light source such as a laser diode 12 coupled to a multimode optical fiber. The fiber 32 functions as both a transmitter, receiver of light ray angle information. An objective lens 40 possessing spherical aberration separates the monochromatic light at different focal distances according to the magnitude of angular deviation from the optical axis. Each distance of the target surface from the objective lens will select specific angular rays able to retrace the path through the objective lens and fiber. Each angle then will correspond to specific distance. Angular information is preserved as the light path is traced back through the fiber 32 and the angle measurement is determined by registering the light impinging on a light sensitive electronic detector array 36.

Abstract: The invention relates to a device for measuring surfaces and to a method, which uses, preferably, the device. The device comprises a light source which is used to produce a multi-colored light beam. The light beam can be focused by an imaging optical system on a plurality of points which are arranged at different distances from the imaging optical system, using the chromatic aberration of the optics. The focused light beam can be deviated to a point of the surface. A sensor device is provided in order to detect the reflected light beam. The aim of the invention is to maintain the largest distance possible between the measuring head and the object. The imaging optical system comprises an optical system for the targeted circulation of a chromatic aberration and an additional optical system which is used to form the focused light beam emerging from the imaging optical system.

Abstract: An apparatus and method of measuring the thickness of a substrate. A first light is reflected from a standard sample having a known thickness. The light is concentrated through the light-focusing lens. The first light is converted into a first electrical signal by a detector responding to a light intensity of the concentrated first light. A second light is reflected from a substrate, and then is concentrated through the light-focusing lens. The second light is converted into a second electrical signal by the detector responding to a light intensity of the concentrated second light. An operating unit determines first and second peak values from the first and second electrical signals, respectively. The operating unit calculates the thickness of the substrate by using a standard distance corresponding to the first peak value, a moving distance of the substrate corresponding to the second peak value, and the known thickness of the standard sample.

Abstract: Focus detecting methods and focus detecting mechanisms of an image measuring device able to execute focus detection at high speed with high accuracy, and image measuring device having the focus detecting mechanisms are provided. A rotation driving device rotates and operates a grating filter for projecting a grating pattern to a measured object. A distance driving device adjusts the interval distance between an image pickup device and the measured object. The image of the measured object projecting the grating pattern thereto every predetermined rotating angle is picked up by the image pickup device via multiple exposure by operating the rotation driving device and the distance driving device in association with each other. A focus position is determined from a contrast value of the grating pattern within the picked-up image information. Accordingly, it is not necessary to pick-up plural images in plural distance positions and process the plural images.

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 device for determining the surface topology and associated color of a structure, such as a teeth segment, includes a scanner for providing depth data for points along a two-dimensional array substantially orthogonal to the depth direction, and an image acquisition means for providing color data for each of the points of the array, while the spatial disposition of the device with respect to the structure is maintained substantially unchanged. A processor combines the color data and depth data for each point in the array, thereby providing a three-dimensional color virtual model of the surface of the structure. A corresponding method for determining the surface topology and associated color of a structure is also provided.

Abstract: A three-dimensional shape measuring apparatus includes a measuring section and a data integrating section. The measuring section has three-dimensional measurement dimensions, and measures a three-dimensional shape of a measurement object in a non-contact state. The measuring section measures a three-dimensional shape of a part of the measurement object multiple times by shifting the measurement dimensions to obtain multiple measurement data. The measurement dimensions are shifted in such a manner that at least portions of consecutive measurement dimensions by the shifting are lapped one over the other. The data integrating section integrates the multiple measurement data to obtain the three-dimensional shape of the measurement object. The data integrating section executes the data integration, using reliability information attributed to the respective measurement data.

Abstract: A device and a method for the contactless measurement of at least one curved surface. The device comprises at least one light source for generating light with a continuous spectrum, and a light exit face assigned to the light source. It furthermore has at least one measurement head having an optical imaging system with chromatic aberration for imaging the light exit face into wavelength-dependent focal planes, and an optical spectral instrument by which it is possible to record the spectral intensity distribution of light which is directed through the optical system onto the surface to be measured and is reflected therefrom. The device is furthermore equipped with an evaluation unit by which a distance between the optical system and the surface can be assigned to each wavelength at which the intensity distribution recorded by the optical spectral instrument has a local maximum. The surface to be measured is plane in one space direction.

Abstract: A confocal displacement sensor is created in which, through a graduated arrangement of optical outputs relative to an imaging optic in the object area of displacement sensor, real images of the optical outputs can be created at different heights. A surface to be measured, which is located in the area between the real images, at least partly scatters back illumination beams emitted by the optical outputs. As such, two measurement beams are created for which the intensities are each recorded by a light detector. This is done by interpolation between the measured light intensities. The height position of the scanned points of the surface can be calculated and the surface to be measured can be measured simultaneously at a number of scanning points. Two planar light sources are preferably used for light generation and two planar high-resolution cameras for light detection.