Abstract: A method for measuring a synchronization error between a first stage and a second stage in a scanning exposure apparatus including the first stage which supports a reticle, the second stage which supports a substrate, and a projection optical system which projects a pattern of the reticle onto the substrate, the method comprises the steps of measuring, using a measurement unit, a light intensity distribution formed by a measurement pattern while synchronously scanning a measurement mask which has the measurement pattern and is arranged on the first stage, and the measurement unit arranged on the second stage, and calculating the synchronization error between the first stage and the second stage based on a time change in the light intensity distribution measured in the measuring step.

Abstract: A weighted fit based on a sample density of a plurality of samples is used to determine an alignment curve. A scan that produces the samples may include portions having greater and lesser sample density. While performing an interpolation to produce a best fit curve, a plurality of neighboring samples are chosen for each sample point, for sample points associated with a value above a threshold. A weighting function may be performed based on a distance between a given sample and the chosen nearest neighbors, wherein measurements that are taken in a region with denser samples are given less weight than measurements that are taken in a region with sparser samples.

Abstract: The present invention relates to a method of aligning comprising providing a support, applying a transparent layer, patterning at least the transparent layer to produce a pattern and an alignment feature capable of scattering light, illuminating the support and the transparent layer with oblique lighting, providing an analysis system capable of sensing scattered light from the alignment feature and referencing, sensing the scattered light from the alignment feature; referencing the scattered light from the alignment feature to a position on said support; and aligning a second operation to the position.

Abstract: In one embodiment, a system for aligning multiple image frames in an LCoS projector is provided. The system includes a plurality of detectors aligned with a desired projection image of a projector. The plurality of detectors is coupled to the projector. Each detector of the plurality of detectors is aligned with an edge of the desired projection image. The plurality of detectors may be coupled to a screen distant from the projector, or part of a calibration unit associated more directly with the projector. The system may further include calibration logic in the projector. The calibration logic is to receive data from the plurality of detectors and to adjust an image of the projectors responsive to the data from the plurality of detectors.

Abstract: Both the 1st and 0th diffraction orders are detected in a scatterometer. The 1st diffraction orders are used to detect the overlay error. The 0th diffraction order is then used to flag if this is a false overlay error calculation of magnitude greater than the bias but smaller than the pitch of the grating.

Abstract: A method for aligning a beam spot with a waveguide portion of a wavelength conversion device includes scanning a beam spot over the input face of the wavelength conversion device while measuring the output intensity of the device such that an output intensity for each of a plurality of fast scan lines is generated. A first alignment set point is then determined based on the output intensity of each fast scan line. A second scan of the beam spot is then performed over the fast scan line containing the first alignment set point while measuring the output intensity for each point along the fast scan line. A second alignment set point is then determined based on the output intensities measured during the second scan. The beam spot is then aligned with the waveguide portion using the first alignment set point and the second alignment set point.

Abstract: An article and a method for testing the assembly of that article are disclosed. The article includes a plurality of modules, at least two of the modules are capable of being placed in two different positions in the article, each module having a correct position in the article. Each module includes an aperture at a location determined by the desired position for that module in the article. The apertures are placed such that the apertures will be aligned to form a transparent channel when the modules are arranged in a predetermined pattern with respect to one another, but not when arranged in any of the possible incorrect orders. The article can be tested for assembly errors by transmitting a test light signal into the first end and testing for light that traversed all of said first transparent channel.

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 capacitative or optical height sensors.

Abstract: A light amount detector includes a light emitter, a light receiver, and a light amount detection unit. The light emitter emits light on a detection pattern formed on a detection surface of an image carrier. The light receiver detects diffused light reflected from the detection pattern. The light amount detection unit detects an amount of light received by the light receiver based on detection output of the light receiver. One of the light emitter and the light receiver is provided at a position directly opposite to the detection surface, such that a distribution of sensitivity of the light receiver detecting the diffused light is substantially symmetrical with respect to a detection output peak when the detection surface is substantially parallel to a hypothetical line connecting the light emitter with the light receiver.

Abstract: A method of inspecting the alignment of a second structure with respect to a first structure, including emitting light from a first plane of a first structure to a second plane of a second structure in a first direction perpendicular to the first plane of the first structure, the first plane and the second plane facing each other. The incident light can be reflected from the second plane toward the first plane in a second direction parallel with the first direction. The position of the reflected light can be detected to inspect the alignment of the second structure with respect to the first structure.

Abstract: By means of a method, at least one component is placed on at least one substrate. The component is picked-up by at least one placement machine and is placed at a desired position on the substrate. After the component is placed on the substrate, an image of the component placed on the substrate is taken by a camera. Any difference between the actual position of the component on the substrate and a desired position of the component on the substrate is established on account of the image. The positioning of another component to be placed on the substrate takes into account any such difference.

Abstract: An ion beam irradiating apparatus has: a beam profile monitor 14 which measures a beam current density distribution in y direction of an ion beam 4 in the vicinity of a target 8; movable shielding plate groups 18a, 18b respectively having plural movable shielding plates 16 which are arranged in the y direction so as to be opposed to each other across an ion beam path on an upstream side of the position of the target, the movable shielding plates being mutually independently movable in x direction; shielding-plate driving devices 22a, 22b which reciprocally drive the movable shielding plates 16 constituting the groups, in the x direction in a mutually independent manner; and a shielding-plate controlling device 24 which, on the basis of measurement information obtained by the monitor 14, controls the shielding-plate driving devices 22a, 22b to relatively increase an amount of blocking the ion beam 4 by the opposed movable shielding plates 16 which correspond to a position where a measured y-direction beam curr

Abstract: A projection lens unit, related exposure apparatus and control method are described in which measurement light irradiating a semiconductor substrate after passing through lenses in the projection lens unit and reference light irradiating the semiconductor substrate without passing through the lenses in the projection lens unit are used to derive a control signal adapted to adjust the position of the semiconductor substrate under the projection lens unit.

Abstract: Fast on-line electro-optical detection of wafer defects by illuminating with a short light pulse from a repetitively pulsed laser, a section of the wafer while it is moved across the field of view of an imaging system, and imaging the moving wafer onto a focal plane assembly, optically forming a continuous surface of photo-detectors at the focal plane of the optical imaging system. The continuously moving wafer is illuminated by a laser pulse of duration significantly shorter than the pixel dwell time, such that there is effectively no image smear during the wafer motion. The laser pulse has sufficient energy and brightness to impart the necessary illumination to each sequentially inspected field of view required for creating an image of the inspected wafer die. A novel fiber optical illumination delivery system, which is effective in reducing the effects of source coherence is described.

Abstract: The disclosure relates to a system and a method for light beam interrogation of an optical biosensor and for monitoring a biological event on the biosensor for use, for example, in microplate image analysis. The system and method correct pointing-errors that can be encountered, for example, in scanning label-independent-detection biosensor applications.

Abstract: An alignment system for optical lithography uses cameras fixed to a movable stage and to a lithography unit to view unique microscopic non-uniformities that are inherent to the surface of a work piece, e.g., metal or ceramic microcrystalline grains, for position referencing. Stage cameras image two sites on the work piece through windows in the stage to establish original position templates. After the work piece has been repositioned, e.g., reversed topside-down, the same two sites are again viewed and template matching establishes the transformed coordinates of the work piece, e.g. by a lithography unit camera under which the stage moves to approximate site locations. Two corner cameras can serve as a coarse positioning mechanism. The alignment system is particular useful for backside alignment in printed circuit board lithography.

Abstract: Methods and systems for determining drift in a position of a light beam with respect to a chuck are provided. One method includes illuminating a surface with the light beam. The surface has a predetermined position with respect to the chuck during illumination. The method also includes generating signals responsive to the illumination of the surface and determining the drift in the position of the light beam with respect to the chuck using the signals. One system includes an illumination subsystem configured to illuminate a fiduciary with the light beam. The fiduciary has a predetermined position with respect to the chuck during illumination. This system also includes a detector configured to generate signals responsive to the illumination of the fiduciary and a processor configured to use the signals to determine the drift in the position of the light beam with respect to the chuck.

Abstract: A laser beam may be used to provide a virtual reference axis of travel for the in-axis direction of motion of lenses in a zoom assembly to be positioned during a zoom operation. The virtual reference axis is projected along the optical axis, parallel to existing mechanical lens slides. The virtual reference axis passes through an aperture on each of the lens assemblies, and is sampled by a set of optics and detectors on each of the lens assemblies. The optics and detectors are arranged such that any change in the position of a lens cell within a lens assembly relative to the virtual reference axis is sensed and corrected using a feedback signal to a positioning motor. Since the same virtual reference axis is used for each lens in the zoom assembly, each lens can be independently corrected for off-axis position errors to very high precision.

Abstract: A device for improving the efficiency of operation for aligning the optical axis of mirrors disposed in an optical path for laser transmission in a laser beam machine. The laser beam output from a laser oscillator of a laser beam machine is transmitted via multiple mirrors disposed in the optical path thereof to a torch. A mirror for receiving the laser beam from the mirror is removed and a laser beam detecting device is attached in replacement thereof. The laser beam is passed through a cross-shape target, a portion of which is branched and taken as image by a laser beam detecting picture element. The operator operates adjusting screws and to change the tilt angle of the mirror while watching image data, so as to align the optical axis of the laser beam.

Abstract: A remotely operated laser survey device for performing a runway survey on a rail system that supports a device such as an overhead crane. The survey device includes a laser assembly and a survey car. The laser assembly can include a self-leveling laser. The survey car includes an image acquisition device and can be self-propelled by a drive mechanism. Images obtained using the image acquisition device are transmitted to a remote computer for analysis. The analysis can include a centroidal analysis of the image. Deviation of the rails is compared to established standards and correction carried out if necessary. The image acquisition device can be triggered to obtain images based on movement of the survey car. The survey car can be centered on a rail of the rail system to ensure accurate results regardless of the condition of the rail.

Abstract: An exposure apparatus performs a relative alignment between a reticle and a substrate, and exposes the substrate to light via a pattern formed on the reticle. The exposure apparatus includes a movable stage that carries one of the reticle and the substrate and a position measurement apparatus that measures a position of at least one of the reticle and the substrate. The position measurement apparatus includes an illumination unit configured to emit light toward a mark that indicates the position of the reticle or the substrate, a light intensity measurement unit configured to measure an intensity of the light, an imaging unit configured to capture an image of the mark, a stage position measurement unit configured to measure a position of the stage, and a signal waveform correction unit configured to correct a signal waveform output from the imaging unit based on a change in stage position and a change in illumination light intensity.

Abstract: A device for aligning a substrate and a mask, and a method using the same, where the device includes aligning marks in unused portions of the substrate and the mask, a sensing unit for determining overlap of the aligning marks when the substrate is aligned with the mask, and a control unit for controlling an aligning process to be repeated on the basis of data sensed and determined by the sensing unit. The sensing unit may include a camera positioned in photographic range to determine any alignment error in the alignment marks. According to another embodiment of the present invention, the alignment error between the substrate and the mask is sensed to determine whether it is acceptable or not. When the alignment error is unacceptable, the operations for aligning the substrate with the mask are repeated until the alignment error is acceptable.

Abstract: The present invention provides an adjustment method for a position detection apparatus which comprises an optical system including first and second optical members whose positions can be changed, and detects a position of an object, comprising the steps of calculating a value representing an asymmetry of a detection signal of a light which enters a photoelectric conversion device via the optical system, for each of a plurality of positions of the first optical member in a direction perpendicular to an optical axis of the optical system, specifying a position of the object in the direction of the optical axis, at which the value is insensitive, for each of the plurality of positions, and adjusting a position of the second optical member in the direction perpendicular to the optical axis based on the value at the position of the object specified in the specifying step.

Abstract: An optical position assessment apparatus and method has an illumination system that supplies an alignment beam of radiation, and positional data is derived from reflections of the alignment beam. A substrate is supported on a substrate table and a projection system is used to project the alignment beam onto a target portion of the substrate. A positioning system causes relative movement between the substrate and the projection system. An array of lenses is arranged such that each lens in the array focuses a respective portion of the alignment beam onto a respective part of the target portion. An array of detectors is arranged such that each detector in the array detects light reflected from the substrate through a respective lens in the array and provides an output representative of the intensity of light reflected to it from the substrate through the respective lens.

Abstract: A flow path unit of one aspect of the invention includes: a plurality of plates, each of the plurality of plates having a hole, the plurality of plates being laminated in a lamination direction with a predetermined positional relationship such that a flow path is formed by mutual communication of the holes provided at the plurality of plates. Each of the plurality of plates having a side surface, and a slit portion formed at the side surface, and the slit portions of the plurality of plates are connected to one another in the lamination direction of the plurality of plates. Each of widths of the slit portions of the plurality of plates is equal to or below an allowable error of a positional deviation of the plurality of plates so as to allow a formation of the flow path by the plurality of holes.

Abstract: By irradiating a detection beam from an irradiation system of a detection device to a scale used for measuring the position of a wafer stage, and detecting the detection beam via the scale by a photodetection system, a surface state (an existence state of foreign substance) of the scale is detected. With this operation, detection of the surface state can be performed contactlessly with respect to the scale. Moreover, movement control of the wafer stage can be performed with high precision by taking the surface state into consideration.

Abstract: An optical alignment method is for a light-emitting module that includes a housing unit, a light-emitting unit disposed in the housing unit, and a lens unit. The optical alignment method includes: (a) through image-capturing techniques, finding a light-emitting point of the light-emitting unit and a predetermined reference point, and determining a total optical path length between the light-emitting point and an imaging plane; (b) finding a first center line that divides the total optical path length in half; (c) through image-capturing techniques, finding opposite first and second edges of the lens unit, and determining a lens length between the first and second edges; (d) finding a second center line that divides the lens length in half; and (e) assembling the lens unit to the housing unit so that the first and second center lines overlap. A light-emitting module and an assembly method therefor are also disclosed.

Abstract: A rail sensing and analysis system utilizes a laser sensor 105, 107 to detect displacement of a rail 102, 104 resulting from loads imposed by a passing rail vehicle. Vertical and/or lateral displacements/loads may be sensed. Signatures in the resulting signals are indicative of useful information about the rail vehicle; such as wheel condition, bearing condition, truck condition, degree of bogie hunting, total load, load distribution, etc. The ratio of Lateral over Vertical force (L/V) may be used as an evaluation criterion.

Abstract: Methods and systems for evaluating and controlling a lithography process are provided. For example, a method for reducing within wafer variation of a critical metric of a lithography process may include measuring at least one property of a resist disposed upon a wafer during the lithography process. A critical metric of a lithography process may include, but may not be limited to, a critical dimension of a feature formed during the lithography process. The method may also include altering at least one parameter of a process module configured to perform a step of the lithography process to reduce within wafer variation of the critical metric. The parameter of the process module may be altered in response to at least the one measured property of the resist.

Abstract: An image measurement method is provided for measuring an image of a pattern of a mask projected with a projection optical system. The method includes the steps of detecting light transmitted through an aperture while a substrate is arranged at an image plane of the projection optical system, the substrate having a slit and the aperture having a width larger than a width of the slit; adjusting an alignment angle of the slit on the basis of a signal related to the light detected in the detecting; and measuring the image by detecting light transmitted through the slit while moving the slit, the alignment angle of which has been adjusted in the adjusting, in the image plane of the projection optical system.

Abstract: A system and method of providing alignment of the top surface of the substrate to alignment marks on the back side of the substrate on a lithographic projection system. A back-side optical alignment system is integrated under a movable substrate stage of the projection system. Alignment marks on the mask, which correspond to the location and separation of the substrate back side alignment marks are projected directly using UV illumination to the back-side optical alignment system, processed by a pattern recognition optical system, and stored. With a substrate on the movable stage, the substrate back-side alignment marks are positioned to correspond with the stored co-ordinate data. The projection system images the front side of the wafer after it has been aligned to the back side alignment marks.

Abstract: Methods and apparatus are provided for locating a notch and/or a center of the notch of a substrate. An exemplary method includes rotating a substrate; illuminating an edge of the substrate with a light beam as the substrate rotates; detecting a change in light intensity of the light beam as the substrate rotates; determining a rough location of a notch in the edge of the substrate based on a position of the substrate when the change in light intensity of the light beam is detected; and reversing a rotational direction of the substrate to determine a fine location of the notch in the edge of the substrate. Numerous other aspects are provided.

Abstract: The invention relates to an image sensor for detection of an aerial image formed by a beam of radiation in a lithographic projection apparatus for exposing a pattern onto a substrate held in a substrate plane by a substrate holder. The image sensor has an image detector and a lens. The lens is arranged to project at least part of the aerial image onto the image detector. The image sensor is positioned such within the substrate holder that the lens is positioned proximate the substrate plane.

Abstract: A wafer pre-alignment apparatus according to this invention includes a wafer rotating member, a rotation detecting member, a light emitting member for emitting light toward the periphery of the wafer, a COD linear sensor linearly arranged and signal processing member for detecting the edge position of the wafer to acquire at least one of an orientation flat position, notch position and center position of the wafer on the basis of the edge position detected, and further includes an up-down counter for converting a signal received from the rotation detecting member into rotating position information, a measured angle setting register for storing the rotation position information when the wafer rotating member rotates by an interval angle and a comparator for comparing a set value in the measured angle setting register and a counted value in the up-down counter.

Abstract: An alignment apparatus for a substrate bonding system is provided with a first optical arm arranged to direct onto a detector radiation from a first alignment mark on a first substrate, and a second optical arm arranged to direct onto the detector radiation from a second alignment mark on a second substrate. The first alignment mark has a known location relative to a functional pattern provided on an opposite side of the first substrate, and the second alignment mark has a known location relative to a functional pattern provided on an opposite side of the second substrate. The substrate bonding system can be further provided with first and second substrate tables arranged to hold the first and second substrates such that they face one another, at least one of the substrate tables being movable in response to a signal output from the detector, thereby allowing the first and second substrates to be aligned with respect to each other for bonding.

Abstract: An optical alignment method is for a light-emitting module that includes a housing unit, a light-emitting unit disposed in the housing unit, and a lens unit. The optical alignment method includes: (a) through image-capturing techniques, finding a light-emitting point of the light-emitting unit and a predetermined reference point, and determining a total optical path length between the light-emitting point and an imaging plane; (b) finding a first center line that divides the total optical path length in half; (c) through image-capturing techniques, finding opposite first and second edges of the lens unit, and determining a lens length between the first and second edges; (d) finding a second center line that divides the lens length in half; and (e) assembling the lens unit to the housing unit so that the first and second center lines overlap. A light-emitting module and an assembly method therefor are also disclosed.

Abstract: A method includes detecting a feature of an input pattern using a plurality of feature detectors, selecting at least one of the feature detectors based on their output values, and calculating a feature quantity of the input pattern based on an output value from at least one selected feature detector.

Abstract: Each target used in a method of measuring overlay using a scatterometer includes a first portion and a second portion, the first portion has features varying only in a first direction and the second portion has features only varying in a second direction. The first and second directions are orthogonal, thus eliminating cross talk between the directions, and improving the accuracy of overlay error calculations.

Abstract: The invention provides an alignment measurement arrangement having a broadband source, an optical system and a detector. The broadband source is arranged to generate a radiation beam with a first and second range of wavelengths. The optical system is arranged to receive the generated radiation beam, produce an alignment beam, direct the alignment beam to a mark located on an object, to receive alignment radiation back from the mark, and to transmit the alignment radiation. The detector is arranged to receive the alignment radiation and to detect an image of the alignment mark located on the object. The detector furthermore produces a first and a second alignment signal, respectively, associated with said first and second range of wavelengths, respectively. The alignment measurement arrangement finally has a processor, which is connected to the detector.

Abstract: A shape value of a pattern having a pivotal characteristic is measured (step S1), an exposure energy variation is detected from the measured value, a first data base is accessed using a result of the measurement of the shape value (Step S2), an exposure energy is calculated (Step S3), a shape value of an isolated pattern is measured (Step S4), a second data base is accessed using a result of the measurement (Step S5), and a focal variation is determined using the calculated proper exposure energy (Step S6).

Abstract: An apparatus for checking concentricity between a barrel holder and a lens barrel rotatably engaging with the barrel holder is provided. The lens barrel includes at least one lens coaxially received therein. The apparatus includes a barrel holder retaining member, a rotating member, a driving unit, a light source, and an image sensor. The barrel holder retaining member is used for fixedly retaining the barrel holder in position. The rotating member is structured for meshing with the lens barrel. The driving unit is used for driving the rotating member to rotate, thereby rotates the lens barrel. The light source is configured for emitting light toward a first end of the lens barrel. The image sensor is arranged to face toward an opposite second end of the lens barrel. The image sensor is configured for sensing the light emitted from the light source.

Abstract: The invention relates to a method for positioning a substrate relative to a substrate table, is presented. When the substrate is positioned on the substrate table for a first time, a first relative position of the substrate with respect to the substrate table is determined. When the substrate is positioned on the substrate table a second subsequent time, a second relative position of the substrate with respect to the substrate table is determined and the position of the substrate table with respect to the substrate is adjusted based on the first and second relative positions, so that the substrate is positioned with respect to the substrate table substantially equally to the first relative position.

Abstract: A method and a system are provided for calibrating metrological tools used to measure features of a semiconductor device. A critical dimension (CD) ruler defines a known pitch plus a pitch offset. A photoresist layer is measured to determine a measured pitch whereupon the measured pitch is compared to the known pitch. From the comparison, appropriate calibration steps can be taken to reduce the difference between the known pitch and the measured pitch.

Abstract: Improved systems, apparatus, and methods for detecting positions of moving stages and accurately compensating position error during operation (in “real time”) are provided. For some embodiments, rather than rely on two dimensional position measurements, measurements in at least three dimensions may be taken allowing compensation for pitch and roll and, therefore, more accurate position measurements. Further, by including a measurement of a beam column, compensation for movement of the beam may be performed.

Abstract: A lithographic apparatus comprises a substrate table that supports a substrate having alignment marks on a surface thereof. The apparatus further comprises a frame moveable relative to the substrate to provide for a scanning or stepping mode of operation. An array of projection systems is disposed across the frame for projecting respective patterned beams onto a target portion of the substrate. A plurality of alignment mark detectors are attached to the frame and are moveable with respect to the frame using respective linear drive mechanisms. A position sensor is associated with each alignment mark detector for determining the position of the detector relative to the frame. A control system is responsible for both initial positioning of the detectors above alignment mark patterns on the substrate, and for dynamic alignment of the frame and substrate during a lithographic process.

Abstract: An exposure apparatus performs AGA measurement by using a predetermined sample shot group formed on a wafer, and decides an alignment parameter. The exposure apparatus executes wafer alignment processing and exposure processing by using the alignment parameter. The exposure apparatus notifies a central processing unit of AGA measurement results and the alignment parameter. An overlay inspection apparatus measures an actual exposure position on the exposed wafer, and notifies the central processing unit of the measurement result. The central processing unit optimizes alignment processing on the basis of the AGA measurement results, alignment parameter, and actually measured exposure position.

Abstract: An optical system for alignment assembly of a field emission display panel comprises an optical lens tube, a lens unit, an image conversion unit and an image processing and display unit. The lens unit has at least two optical lenses corresponding to a first outlet end and a second outlet end of the optical lens tube, respectively. A reflective translucent lens is disposed in the optical lens tube to correspond to the inlet end and the first and second outlet ends. The reflective translucent lens transmits several optical signals generated during alignment of the anode and cathode substrates to the lens unit. The image conversion unit and the image processing and display unit are used to display the image captured by the optical lenses on the same display, thereby accomplishing image capture and alignment reference for reference points of the anode and cathode substrates at different focus depths.

Abstract: Substrate processing apparatus includes a lithographic apparatus which comprises an illumination system for supplying a projection beam of radiation, an array of individually controllable elements serving to impart the projection beam with a pattern in its cross-section, and a projection system for projecting the patterned beam onto a target portion of a substrate. The processing apparatus also includes a substrate supply arranged to output at least one unbroken length of substrate, and a substrate conveying system arranged to convey each outputted unbroken length of substrate from the substrate supply and past the projection system such that the projection system is able to project the patterned beam onto a series of target portions along each unbroken length of substrate. In certain embodiments, long lengths of substrate are supplied from a roll, but alternatively a series of separate sheets can be supplied.

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: An image display device including a plurality of laser light sources arranged to produce angularly offset beams of light, and scanning optics configured to raster scan the angularly offset beams of light simultaneously across separate parallel lines of pixels of a display surface to form an image, wherein each beam of light scans substantially the entire display surface.