Abstract: A portable electronic device is provided which an operator (photographer) has not an abnormal but favorable feeling from a design (aesthetic) viewpoint and which enables the operator to know an area in which a photograph can be successfully taken or a position of a subject to be photographed. A control section has an auxiliary display section display present time, notification of arrival of data and/or messages, or a like when no photograph is taken. When the operator presses down a photographing mode selecting key, the control section controls a liquid crystal panel so that its all pixels are put into a light transmitting state and causes reflected light from a mirror reflecting plate to be visually viewed by the operator. That is, the auxiliary display section operates as the mirror to look therein at an image of a subject to be photographed.

Abstract: First image data and second image data are generated by capturing a subject image at a CCD. The first image data captured over a first exposure time manifest a relatively small extent of image blur. The second image data are captured over a second exposure time set longer than the first exposure time. A spatial frequency analysis is implemented on the first image data and the second image data to calculate the amplitude ratio and the phase difference of the high-frequency components in the two sets of image data. Based upon the amplitude ratio and the phase difference of the high-frequency components thus calculated, the spatial frequency component of the second image data is corrected to generate third image data in which any image blur has been corrected.

Abstract: A system, a method, and software for image fusion are disclosed. Image sensors sense light and generate image sensor data in response to the light. Spectral detectors detect energy of the light proximate each image sensor, and a voltage value corresponding to the detected energy is determined. A weight factor for each image sensor is calculated according to the voltage value. The image sensor data from each image sensor is weighted according to the weight factor for the image sensor, and the weighted image sensor data are fused.

Abstract: An electronic still camera includes an image pickup unit for picking up an object image to generate a frame image, the image pickup unit having a single pickup mode of picking up an object image to generate a single frame image, and a continuous pickup mode of picking up an object image continuously to generate a plurality of continuous frame images, and a display unit for displaying a frame image in a display manner specialized to the pickup mode in which the frame image is generated. Each frame image is stored in a memory, and given with pickup mode information representing which the frame image is generated in the single pickup mode or the continuous pickup mode.

Abstract: The brightness of image data is previously defined based on the R, G, and B values of each pixel. In an image considered to have been exposed appropriately by a conventional method, when the brightness histogram for the defined image is computed, pixels having the maximum value in the definition of brightness always occupy a predetermined rate (1% or so) of all pixels. Based on this rule of thumb, the gain of an image acquisition device or the pixel value of acquired data is adjusted so that a brightness histogram (3) for image data which is an object of adjustment becomes a histogram (4) having the same characteristic as the above-mentioned appropriately exposed image.

Abstract: In short, the image processing device for obtaining a single image by using a plurality of image-pickup elements comprises a plurality of image-pickup signal processing circuits that are provided for each of the image-pickup elements, an image arrangement conversion circuit which converts the read-out order of the images corresponding to the respective image-pickup elements that are output from the image-pickup signal processing circuits, an image splitting processing circuit for performing image splitting on the image that is output from the image arrangement conversion circuit, an image processing circuit for performing image processing in parallel on each of the split images, and an image compression circuit for compressing in parallel each of the split images that are output from the image processing circuit.

Abstract: A camera includes a first sensor disposed to image light that propagates along a reflected axis, a second sensor disposed to image light that propagates along a direct axis, and a rotatable structure disposed to define a rotation plane that is oblique to both the reflected axis and the direct axis. The rotatable structure includes either a first transmission sector, a first reflection sector disposed adjacent to the first transmission sector, a second transmission sector disposed adjacent to the first reflection sector and a second reflection sector disposed adjacent to the second transmission sector or the rotatable structure includes a first reflection sector, a first opaque sector disposed adjacent to the first reflection sector, and a first transmission sector disposed adjacent to the first opaque sector.

Abstract: The invention relates to a camera system and to a display device for displaying images recorded by the camera system. The camera system comprises a camera (1) provided with an optics system (2) and a photosensitive image surface (3) disposed near the optics symmetrically relative to its optic axis, the image refracted by the optics being projected onto said image surface. The photosensitive image surface is a concave spherical surface whose center of curvature is at the focal point of the optics.

Abstract: A device and process which eliminates potential moiré patterns in digitized images by employing a one-dimensional sensor array and a sampling method of the sensor signals which produces a data set of non-uniformly spaced sensor positions. This allows the spacing of the sensors to avoid having a strong “harmonic” which may interfere with details or harmonics present in the image source, which eliminates the occurrence of moiré patterns and the need for application of image processing to remove moiré patterns. Sensors are non-uniformly spaced along a first axis according to a predetermined scheme or function. Sensors are sampled during scanning according a non-uniform function in order to realize a non-uniform sampling scheme in a second dimension. Linear interpolation is applied to the non-uniformly spaced data set, synthesizing a uniformly-spaced data set for use in common imaging formats and processing.

Abstract: A photodetector (105) generates an electrical signal that has a value that changes approximately linearly at a rate that is proportional to an amount of light intensity incident on a photodetector since a most recent reset command was received at a reset input of the photodetector. A measurement circuit (110) generates a comparison state that is based on a comparison of the value of the photodetector signal to a reference signal in response to one of a plurality a sample pulses. A control circuit (160) generates the plurality of sample pulses at non-uniform time intervals and generates an elapsed time as an accumulation of the non-uniform time intervals occurring from the reset command to a change of the comparison state. In one embodiment, the reciprocal of an accumulated duration of the non-uniform time intervals is a linear function of a number of time intervals after the reset command.

Abstract: A solid-state image pickup device is provided which includes an electric charge accumulation region capable of accumulating electric charges, a reset transistor having a first terminal and a second terminal, in which an electric charge discharge potential is applied to the first terminal and the second terminal is connected to the electric charge accumulation region, and a source follower circuit including a driver transistor having the same structure as the reset transistor. An electric charge accumulation voltage of the electric charge accumulation region can be set to the electric charge discharge potential through the reset transistor. An output voltage from the source follower circuit is the electric charge discharge potential.

Abstract: A fast imaging device 32 has a charge signal converter 33, a charge signal accumulator 36 and a charge signal transporter 37. A charge signal accumulator 36 is provided to each charge signal converter 33. A charge signal accumulator 36 extends linearly while inclining with respect to a line L2 connecting charge signal converter 33. The other end of a charge signal accumulator 36, connected at one end thereof to a charge signal converter 33 constituting a corresponding column, merges to a charge signal transporter 37. This construction reduces noise and increases a frame rate.

Abstract: An iris camera module includes an image pickup optical system and a target optical system and the optical path is divided by a half mirror. An image of an iris is picked up by an image pickup element of an image pickup section. The iris image thus picked up is compared with a reference iris image stored in a storage in advance and the comparison result is output. The iris camera module has a configuration fit for a compact design. The reference iris image as a reference for comparison is stored in the storage of the comparison chip. It is thus difficult to falsify the reference iris image thereby providing a high security.

Abstract: A method of positioning by using image uses an image-collecting device with a known angle of view to gain a digital image. A pixel matrix of the digital image is defined as the known angle of view and a gap between every two adjacent pixels of each horizontal line and each longitudinal line is an equally divided angle of the known angle. A displaying objective is shown on an image sensor and has a datum point of computing of a position angle. A camera lens has a principal axis directing to the datum point such that a calculating unit can compute an angle formed between the displaying objective and the principal axis.

Abstract: When a shutter key is pressed, the first image (in-focus image) is picked up and temporarily stored. The focus position is changed to a near- or far-focus position. The second image (out-of-focus image) is picked up and synthesized with the first image. The synthesized image is a soft-focus image in which a background around the contour of a main object is blurred.

Abstract: An improved method for automatic exposure control at a digital camera is described. In response to a user request for capture of a digital image, image data is captured on the camera's image sensor. The captured image data includes pixel values of brightness of pixels of the image sensor. A histogram of pixel values is generated based upon brightness of pixels of the image sensor. The histogram that is generated is then evaluated to determine whether an image is overexposed or underexposed. Coarse exposure settings for capture of a digital image are automatically generated based upon scaling the histogram of pixel values towards the midpoint of a pre-selected interval. The coarse exposure settings and image data that have been captured are evaluated to determine whether light sources are present. In the event that light sources are determined not to be present, the coarse exposure settings are adjusted based upon not scaling said histogram beyond the largest histogram value.

Abstract: A method and system for deinterlacing an interlaced video stream is presented. The method and system determines whether an interlaced video stream is a normal mode video stream or a special mode video stream. Special mode video streams, which interlaced video streams created from a progressive original video stream, are deinterlaced using special mode deinterlacing, which involves merging two fields to form a frame. Normal mode video streams are deinterlaced using normal mode deinterlacing, which involves converting a field into a frame using line repeating or some form of interpolation to generate the missing scan lines.

Abstract: In synchronization of a conventional AV system, when a stream as the master stops, a system clock cannot be corrected for synchronization. Since the correction is consistently performed even when an error is small, overhead of correction is large. On the other hand, when an error is large, sharp correction causes a feeling that something wrong. In the present invention, when the stream as the master stops, previously registering the degree of priority regarding the master, consideration of a corrected period or a previous error for the system clock, or transmitting a stream containing information regarding the master can allow for other process to serves as the master. Accordingly, it is possible to provide a method for synchronization with maintaining correction of the system clock. When a corrected error is large, gradual correction or reference can provide a system with normal feeling.

Abstract: A synchronization pulse detector includes an absolute value independent shape detector for processing samples of an input signal having a synchronization pulse and a plurality of non-synchronization pulses to determine whether such samples have a predetermined sequence. The predetermined sequence includes a first and second absolute value independent time-varying portions and a first and second absolute value independent non-time varying portions. One of the first and second absolute value independent time-varying portions having a positive slope and the other one of the first and second absolute value independent time-varying portions having a negative slope.

Abstract: A method (200) for verifying a video format supported by a display device (25). The display device (25) is adapted to receive a television signal from a video source (10) via a video interface (15). The method includes: receiving (202) a data structure (75) provided by the display device (25), the data structure (75) specifying a plurality of timing parameters associated with a supported video format; providing (204) a plurality of predetermined value ranges, each of the plurality of predetermined value ranges corresponding to one of the plurality of timing parameters; separating (206) the data structure into a plurality of portions, each of the plurality of portions corresponding to one of the plurality of timing parameters; comparing (208) at least some of the plurality of portions with at least some of the plurality of predetermined value ranges; and based on the comparisons, determining whether the supported video format is verified.

Abstract: Overlaying visual interface information atop a video signal without obscuring desired features of the video signal. The video signal may contain one or more pre-selected features, such as text. Two or more display sections equally divide the video signal, and any pre-selected features in the video signal are identified as residing in particular display sections. Depending on the nature of the features, the selected visual interface information is placed atop the video signal in a display section not containing any pre-selected features so as not to cover or obscure the features or is placed over specified features that do not significantly contribute to the video signal, such as blank or static screen regions. A hierarchy of preferred display sections for placing the visual interface information may be created to optimize the placement thereof. The methods for overlaying visual interface information find particular application with interactive television systems.

Abstract: A system and system for performing adaptive recursive noise reduction with still pixel detection on a video stream is presented. After processing a field pixels that were modified are stored in the field so that processing of later fields uses the modified pixels. Furthermore, the system uses novel still pixel detection routines that include multiple thresholds and multiple windows of pixels so that noise reduction is only performed on still pixels.

Abstract: A processor for enhancing an input luminance signal including: a circuit for calculating a chroma edge value associated with the input luminance signal; a circuit for measuring a luminance gradient associated with the input luminance signal; a peaking filter for processing the input luminance signal; a gain adjustment circuit having a gain function that is adjustable relative to the calculated chroma edge value, the gain adjustment circuit being operable to adjust the magnitude of the output of the peaking filter wherein: in a first range of luminance gradients, the output is an attenuated version of the input; in a second range of luminance gradients the output is directly proportional to the input; in a third range of luminance gradients, the output is inversely proportional to the input; wherein the enhanced luminance signal is the sum of the input and output of the peaking filter.

Abstract: A method and/or apparatus for separating a video signal into a luminance signal and a chrominance signal is disclosed. The method first generates a target video signal and a plurality of reference video signals by delaying the video signal, then generates a plurality of intermediate signals such as an HCS, VCS and SLED according to the target signal and the plurality of reference signals, and finally generates the chrominance signal of the video signal by determining the HCS, the VCS, and the SLFD and generates the luminance signal of the video signal according to the chrominance signal of the video signal and the plurality of reference video signals.

Abstract: An apparatus, system and method for clamping a video signal input to a coupling capacitor (215) for providing a clamping voltage. A charging current is applied to the capacitor (215) via an amplifier (225) having a first input (227) coupled with the capacitor output and a second input (226) coupled to a reference potential, the amplifier (225) is responsive to the capacitor output signal and the reference potential for providing the charging current to the capacitor (215). The current has a linearly varying magnitude which is proportional to a difference between the capacitor output and the reference potential.

Abstract: A projection television including a CRT assembly projecting image beams and a reflecting mirror reflecting the image beams. The projection television has a support casing having support frames provided on both sides thereof below the reflecting mirror, receiving and supporting the CRT assembly, and a lower frame coupled to the bottom of each support frame, supporting the support frame. With this configuration, the present invention provides a projection television having a support casing whose weight is reduced, thereby facilitating transportation thereof and reducing the cost of production and transportation, etc., and further being unlikely to be deformed or deteriorated because of changes in temperature and humidity.

Abstract: A portable DVD player, having an output terminal, is detachably received in a console arrangement. The console arrangement includes a DVD player housing, which is adapted for securely supporting within an interior of a vehicle, having a receiving cavity to detachably receive the portable DVD player therein and including an output adapter, which is arranged for electrically extending from a power source of the vehicle, detachably connected to the output terminal of the portable DVD player so as to electrically connect the portable DVD player with respect to the power source of the vehicle.

Abstract: A liquid crystal display panel capable of improving a picture quality and reducing power dissipation includes a plurality of liquid crystal cells each having a thin film transistor formed at a crossing of gate lines and date lines, and a pixel electrode connected to the thin film transistor; a first parasitic capacitor formed between a data line and an adjacent preceding or succeeding pixel first electrode; a second parasitic capacitor formed between the data line and an preceding or succeeding pixel second electrode; and a groove formed at a portion of the pixel electrode adjacent the data line and opposing a portion coupled to the thin film transistor.

Abstract: An electro-optical device including, above a substrate: data lines extending in a first direction, scanning lines extending in a second direction which intersects the data lines, pixel electrodes and thin film transistors provided so as to correspond to intersection regions of the data lines and the scanning lines, and storage capacitors electrically connected to the thin film transistors and the pixel electrodes. Dielectric films which constitute the storage capacitors are made of a plurality of layers including different materials and one of the plurality of the layers is made of a material having a higher dielectric constant than those of the other layers.

Abstract: A liquid crystal display having a liquid crystal display panel driven according a dot inversion method using a data driver driven according to a column inversion method includes dummy liquid crystal cells formed in first and last ones of successive columns in the liquid crystal display panel.

Abstract: A display includes a polarizing member and a reflective display element behind an EL element. The EL element self-emits light to display information and doubles as a display-use light source for the reflective display element. In a sufficiently bright environment, ambient light enters a liquid crystal layer after passing through a frontal substrate of the reflective display element, and is reflected from a metal electrode to produce displays. In addition to the direct light from the EL element, light that enters the liquid crystal layer is simultaneously used. In a dark environment, the EL element emits light, and displayed contents are visible owing to the reflection from the metal electrode as well as directly exiting light.

Abstract: A method of fabricating an optical device by providing a nematic liquid crystal; providing a photo-curable pre-polymer mixture; mixing the nematic liquid crystal with the photo-curable pre-polymer mixture to form a homogeneous nematic/pre-polymer mixture, with the nematic liquid crystal representing greater than 40% (by weight) of the combined homogeneous mixture. Providing a cell including a pair of transparent substrates that are each coated with a transparent conductive layer when creating an electrooptic device and omitting the conductive layers when creating a static device. Separating the substrates by approximately 5–20 ?m or greater; filling the cell with the homogeneous nematic/pre-polymer mixture; and photo-curing the nematic/pre-polymer mixture using a spatially inhomogeneous illumination source thereby forming a polymer dispersed liquid crystal (PDLC) film exhibiting low scattering loss and high index modulation.

Abstract: Among insulating layers for insulating and separating first wiring lines, second wiring lines, and pixel electrodes constituting a reflection type display device, at least one layer is made of an insulating film in which a carbon-based material or a pigment is dispersed. By this structure, a conventional step of forming a black mask can be greatly simplified.

Abstract: A liquid crystal display panel of the type having reflection electrodes tends to have an image-forming plane undesirably yellowed due to the wavelength dependency of transparency observed in an orientation layer on the reflection electrodes; aluminum-neodymium alloy, which has neodymium content between 5 weight % to 10 weight %, is deposited on an inter-layered insulating layer at the substrate temperature equal to or less than 170 degrees in centigrade for the reflection electrodes so that the surface morphology is represented by average pitches equal to or less than 1 micron; even though the orientation layer has the wavelength dependency of transparency, the reflection electrodes make the optical path in the orientation layer equalized so that the image-forming plane is not yellowed.

Abstract: A reflective plate used in a liquid crystal display including a substrate, a first peak and depression layer of organic insulator on the substrate, a second peak and depression layer of organic insulator overlapping with the first peak and depression layer, and a reflective layer on the first and second peak and depression layers.

Abstract: Disclosed are a transreflective type LCD and a method of manufacturing the same. A color filter substrate is formed with a light transreflective member for reflecting an external light or transmitting an artificial light and a visual angle increasing member for increasing the visual angle of the light from the light transreflective member. A thickness of a color filter varies to obtain a uniformity of the light from the light transreflective member regardless of the transmissive and the reflective modes. The light from the light transreflective member is provided through a TFT substrate to a user as an image.

Abstract: The invention provides a liquid crystal display device capable of displaying colors clearly and with high visibility in both a reflective mode and a transmissive mode. The liquid crystal display device according to the invention can be a transflective liquid crystal display device including a reflection layer, color filters in which coloring layers of different colors are arranged corresponding to sub-pixel regions, and light shielding layers for partitioning the adjacent sub-pixel regions, and the transflective liquid crystal display device displays images in reflective regions and transmissive regions. Colored regions, in which the coloring layers of the color filters exist, and non-colored regions, in which the coloring layers do not exist, are provided in the reflective regions. Both the colored regions and the non-colored regions can be provided so as to overlap the light shielding layers along the longitudinal direction of the sub-pixel regions in plan view.

Abstract: A display device comprising a liquid-crystal cell element (20) placed between two polarizers (23, 28) comprising at least one optical structure for compensating for the variations in birefringence of said liquid crystal according to the viewing angle. The optical compensation structure comprises at least one oblique-axis film (25, 26) of polymerized liquid-crystal type suitable for at least partly compensating for the undesirable effects of the natural birefringence of the liquid crystal, combined with a volume hologram (24, 27) of small retardation suitable for improving the compensatability of said film.

Abstract: A positive uniaxial film 14 with a retardation of Rp [nm] in an in-plane direction is provided between a vertical alignment mode liquid crystal cell 11 and a polarizing plate 12, and a negative uniaxial film 15 with a retardation of Rn [nm] in a thickness direction is provided between the liquid crystal cell 11 and a polarizing plate 13. Further, when a parameter ?1 [nm] relative to Rp is: ?1=135?0.7×Rtac; and a parameter ?1 [nm] relative to Rn is: ?1=Rlc?65?1.4×Rtac, where Rtac [nm] is a retardation in a thickness direction of the respective triacetyl cellulose films 12b and 13b of polarizing plates 12 and 13, the retardations Rp and Rn are set to be values greater than 90% but smaller than 110% with reference to the parameters ?1 and ?1, respectively. This makes it possible to surely provide a vertical alignment mode liquid crystal display device which can maintain a high contrast when viewed from an oblique direction.

Abstract: In a process of forming a LCD cell structure, an electrode layer provided with a recessed portion is formed over a substrate, and a transparent dielectric layer is formed to cover the recessed portion of the pixel electrode layer. The recessed portion of the electrode layer acts to distort an electric field created in the liquid crystal of the LCD system for image displaying, while the transparent dielectric layer eliminates the boundary conditions created by the concavity of the recessed portion of the electrode layer.

Abstract: An in-plane switching mode liquid crystal display device includes: first and second substrates facing and spaced apart from each other; a gate line on the first substrate; a data line crossing the gate line to define a pixel region including a plurality of domains; a thin film transistor connected to the gate line and the data line; a common line parallel to and spaced apart from the gate line; a common electrode extending from the common line and having a ring shape; a pixel electrode connected to the thin film transistor and having a ring shape, the pixel electrode alternating with the common electrode; and a liquid crystal layer between the pixel electrode and the second substrate, the liquid crystal layer in neighboring domains having orientation directions different from each other.

Abstract: Pixel regions are formed on a liquid-crystal-side surface of one substrate out of respective substrates which are arranged to face each other in an opposed manner with liquid crystal therebetween, wherein each pixel region includes pixel electrodes having bent portions and counter electrodes which are arranged at positions where the pixel electrodes are shifted in parallel, the pixel electrode and the counter electrode are respectively constituted of two electrodes which are overlapped to each other as an upper layer and a lower layer by way of an insulation film, and to the lower-layer side electrode of at least one electrode out of the pixel electrode and the counter electrode, projections which further project from crests of convex-portion sides of the bent portions and extend toward another electrode side are provided.

Abstract: A method of fabricating a liquid crystal display device is provided. An aluminum alloy layer and a copper metal layer are sequentially formed on a substrate. A photoresist pattern is formed on the copper metal layer and the copper metal layer and the underlying aluminum alloy layer are etched to form a gate line. A gate insulating layer, an amorphous silicon layer and an impurity-doped amorphous silicon layer are deposited and then etched to form a semiconductor layer. An aluminum alloy layer and a copper metal layer are sequentially formed and etched on the structure to form a data line, a source electrode and a drain electrode. A passivation layer is formed and a contact hole and a pad opening are formed in the passivation layer. A transparent conductive thin film is deposited on this structure.

Abstract: The present invention concerns an electro-optical cell, in particular a liquid crystal display cell (2), or an electrochemical photovoltaic cell, including in particular a first transparent front substrate (4) and a second back substrate (6) which may or may not be transparent, said substrates (4, 6) being joined by a sealing frame that defines a volume (8) for retaining a sensitive material whose physical properties, particularly optical, or electrical properties are capable of changing, said substrates (4, 6) including on their faces opposite each other at least one electrode (14, 16), these electrodes (14, 16) being intended to be connected to an electrical power or control circuit, said cell (2) being characterised in that the sealing frame includes at least one wall (12) structured on one of the two substrates (4, 6) and which defines via its inner lateral face the volume (8) for retaining the sensitive material, the substrates (4, 6) being joined by a sealing frame (30), which occupies at least part of

Abstract: There is provided a liquid crystal display device manufacturing method that comprises the steps of forming a sealing member along a periphery of a display area on a first surface of a first substrate, dropping a liquid crystal to the first surface of the first substrate from a top end of a liquid crystal supply needle provided to a lower end of a syringe in which the liquid crystal is filled, and dropping down the liquid crystal adhered to a surface of the liquid crystal supply needle onto the first substrate by an external force in a middle of dropping of the liquid crystal or after the liquid crystal is dropped. Accordingly, an amount of liquid crystal supplied to the substrate can be controlled with high precision.

Abstract: An exposure method includes the steps of introducing fluid to a space between a surface of an object to be exposed, and a final surface of a projection optical system, projecting a pattern on a mask onto the object via the projection optical system and the fluid, wherein the introducing step includes the steps of filling the fluid in the space between the surface of the object and the final surface of the projection optical system, and wherein the filling step changes a capillary attraction of the fluid different from the capillary attraction that operates during the projection step.

Abstract: An exposure apparatus including an illumination optical unit for irradiating exposure light, a stage for mounting a substrate and moving the substrate, a driving unit for driving the stage, a heater for applying heat to the stage, and a heat generation amount control unit for controlling heat generation amount to suppress a temperature change of the stage before or after driving of the driving unit or a temperature change of the stage before or after irradiating of the illumination optical unit.

Abstract: A scanning exposure apparatus includes a projection system, a stage system, a first detector and a control system. The stage system has first and second stages, each of which is movable independently in a plane while holding a substrate. The first detector detects focusing information of a vicinity of an outer circumference of the substrate during a detecting operation. The control system controls the stage system to perform the detecting operation with the first stage, while performing a first exposure operation on the substrate held by the second stage. After the first exposure operation, a second exposure operation for the substrate held on the first stage is performed, in which a shot area in the vicinity of the outer circumference of the substrate is exposed by moving the first stage while adjusting a position of the substrate surface held by the first stage using the detected focusing information.

Abstract: An embodiment of the invention may be applied to measure the positions of features in a alignment region on a mask with a sensor. The positions of the features in the alignment region are known from the design. A feature of which the position is measured, is identified by comparing the relative positions between measured features with relative positions known from the design. The known position of the identified feature is subtracted from a measured position of the identified feature to give the position of the mask.

Abstract: A lithographic apparatus comprises an illumination system for providing a projection beam of radiation, a support structure for supporting patterning device, the patterning device serving to transmit or reflect radiation in the projection beam and impart the projection beam with a pattern in its cross-section, a substrate table for holding a substrate, and a projection system for projecting the patterned beam onto a target portion of the substrate. A sensor is provided for measuring the spatial intensity distribution of the projection beam at the substrate. The spatial distribution of transmission or reflectance of the patterning device, together with the distribution of the projection beam incident on the patterning device, may be determined from the measured intensity distribution. By comparing the transmission or reflectance from regions having identical patterns the overall (macroscopic) distribution of the transmission or reflectance of the patterning device can be determined.