Abstract: Systems and methods for measuring the flow of a liquid along a conduit are disclosed. A heat source applies thermal energy to a portion of a liquid flowing along a conduit thereby elevating its temperature. A light source generates a first beam that passes through the liquid in the conduit downstream from the position of application of the thermal energy and an optical detector receives this beam in combination with a second beam that is not passed through the liquid in the conduit and measures a change in intensity of a combined beam. The time required for the heated portion of the liquid to move from the point of application of thermal energy to the point at which the beam passes through the liquid is measured. This measured time, along with the distance of separation of the heat source and the optical sensing means permits calculation of the velocity of the liquid in the conduit.

Abstract: Color-coding is used to simplify the prior art floating-element Moiré shear-stress sensor. The use of color-coding allows conversion of the Moiré sensor into a 2-D area array sensor, provides a simplified method that saves costs associated with data acquisition and analysis and permits the use of color in the mapping of shear stress distribution.

Abstract: A chemical imaging system is provided which uses a near infrared radiation microscope. The system includes an illumination source which illuminates an area of a sample using light in the near infrared radiation wavelength and light in the visible wavelength. A multitude of spatially resolved spectra of transmitted, reflected, emitted or scattered near infrared wavelength radiation light from the illuminated area of the sample is collected and a collimated beam is produced therefrom. A near infrared imaging spectrometer is provided for selecting a near infrared radiation image of the collimated beam. The filtered images are collected by a detector for further processing. The visible wavelength light from the illuminated area of the sample is simultaneously detected providing for the simultaneous visible and near infrared chemical imaging analysis of the sample. Two efficient means for performing three dimensional near infrared chemical imaging microscopy are provided.

Abstract: A chemical imaging system is provided which uses a near infrared radiation microscope. The system includes an illumination source which illuminates an area of a sample using light in the near infrared radiation wavelength and light in the visible wavelength. A multitude of spatially resolved spectra of transmitted, reflected, emitted or scattered near infrared wavelength radiation light from the illuminated area of the sample is collected and a collimated beam is produced therefrom. A near infrared imaging spectrometer is provided for selecting a near infrared radiation image of the collimated beam. The filtered images are collected by a detector for further processing. The visible wavelength light from the illuminated area of the sample is simultaneously detected providing for the simultaneous visible and near infrared chemical imaging analysis of the sample. Two efficient means for performing three dimensional near infrared chemical imaging microscopy are provided.

Abstract: A CW lightwave modulated by a continuously reiterated autocorrelated spectrum-spreading signal is launched into an end of a span of ordinary optical fiber cable. Portions of this lightwave back propagate to the launch end from a continuum of span locations because of innate fiber properties including Rayleigh effects. This is picked off the launch end and heterodyned producing an r.f. beat signal. The beat signal is processed by a plurality (can be thousands) of multifunction despreader, autocorrelator and de-multiplexer units respectively operated in different time delayed relationships to the timing base of launch signal reiteration. This provides r.f. time-domain reflectometry outputs representative of acoustic, or other signals incident upon virtual sensors at positions along the fiber corresponding to the various delay relationships. Material attenuation of undesired noises (e.g., reflections due to presence of couplers in the fiber cable line) is effected by the spectrum spreading and de-spreading.

Abstract: An apparatus utilizes optical reflectivity (REF) to measure concentrations in liquids. The REF optical system is packaged in a compact and cost-effective form factor. An electronic circuit drives the optical system. The miniaturized REF sensor is situated in an optical-fluidic cell or an optical-fluidic manifold with an optical window in contact with the liquid. Changes in a total internal reflection (TIR) signal are sensitive to temperature and concentration of the liquid. These changes in the TIR signal are used to accurately determine the concentration in the liquid. The liquids may be either static or dynamic.

Abstract: A method of detecting foreign objects in display manufacturing process, wherein the method comprising steps as flows: First a laser source and a laser detector are provided on a first side of a target to be measured, wherein the laser detector is supported by an adjustable gauge to provide the laser detector both horizontal and vertical movement. Then, a reflector located is provided on a second side of the target, wherein a laser beam coming from the laser source passes through a detecting position over the surface of the target, and is reflected to the laser detector by the reflector. Subsequently the intensity of the reflected laser beam is received and measured of by the laser detector.

Abstract: The invention relates to an inspection method for inspecting the quality of a weld seam (15) during which a material, which is transparent to electromagnetic radiation (30) of a defined frequency, is used in a workpiece (10) consisting of two plastic parts (11, 12). In order to be able to reliably inspect the weld seam, the invention provides that an electromagnetic inspection radiation (30) is irradiated inside the workpiece (10). The resulting reflections between the boundary surfaces in the workpiece (10) and the portions of inspection radiation (30, 30?) exiting from the workpiece (10) are affected by the quality of the produced weld seam (15). (15). By measuring the exiting radiation (33, 33?), it can be clearly determined whether the workpiece (10) has a defective or a tolerable seam (15).

Abstract: Examination devices and methods operating with incident light have hitherto been used for the examination of wafers. To allow these devices also to be used with the transmitted-light method, it is proposed to configure the substrate holder (16) so that an illumination device (38, 40, 42) is integrated into the substrate holder (16) in such a way that transmitted-light illumination of the wafer (18) is possible.

Abstract: An improved method of analyzing target analytes in a sample is described. The method is based on anti-resonant guided optical waveguides which enables a strongly improved light-target interaction since the light can be guided within the target-containing medium. The light-target interaction can be monitored by many different means to determine characteristics of the target analyte. The anti-resonant waveguide concept is suitable for a large variety of characterization methods and combinations of them, since it is relatively unaffected by changes to both wavelength and film thickness.

Abstract: An in-situ spectrograph having a spectrometer module positioned at a reticle plane or at a wafer plane of a photolithography projection system is disclosed. The spectrometer module disperses light projected from an illumination source, and the produced spectrum may be recorded. The spectrum may be recorded using a photodetector or a layer of photoresist. The recorded spectrums produced by illumination sources of a plurality of steppers may be compared, thus providing a comparison of the wavelength characteristics, particularly the wavelength spread and intensity of the light of the illumination sources. A plurality of spectrometer modules may be used to provide a comparison of the central wavelength of light produced by the illumination sources. The absolute wavelength of light produced by an illumination source may be determined using a spectrometer module having a spectrometer grating.

Abstract: A measuring head of the present invention conveys light from an external source through at least one optical fiber to at least one respective plane mirror inside the measuring head, where the light reflects through and is collimated by at least one collimating lens so as to be incident on a sample, in one embodiment, at an angle of substantially 45 degrees. The resulting optical path is folded once and thereby allows enough virtual space to redirect the light without excessive bending of the fibers. Light diffused from the sample is, in one embodiment, perpendicularly collected by a focusing lens, focused on the end of another optical fiber and directed outside of the measuring head to be used, for example, by a measuring instrument for the spectral analysis of the collected light.

Abstract: Methods are provided for measuring isotropic scattering coefficients of suspensions using multiply scattered radiation that is modulated in amplitude at selected modulation frequencies. The radiation may be light. Quantities describing diffusion of the multiply scattered radiation are preferably measured at a plurality of distances between source and receiver and a plurality of frequencies. Linear regression techniques are provided for maximizing accuracy of the scattering data at a selected wavelength of a radiation. Methods are provided for inversing an integral equation so as to determine a calculated value of scattering coefficient. Parameters are varied to minimize the difference between the calculated and measured scattering coefficients and thereby to determine volume fraction, particle size distribution and interparticle force between the particles in a suspension.

Abstract: A method of measuring properties of particles immersed in a body (B), comprising the performing of a series of instantaneous acquisitions by illumination of the body with a temporally coherent light beam (152) of predetermined width D and predetermined wavelength ? such as to generate scattered radiation (155) by scattering interaction of the light beam with the particles, and the detection of a plurality of values of the intensity of the total radiation (155, 156 155?,156?) coming from the body at a plurality of points simultaneously, the points being at a distance z from the body such that the points can receive the scattered radiation (155, 155?) which comes from substantially all of the directions in which the particles are capable of scattering, and that each of the points receives the scattered radiation (155, 155?) of a large number of particles, and processing (100) of the series of acquisitions in a manner such as to determine the properties of the particles.

Abstract: A method and apparatus using two sets of polarized light detection systems are disclosed for optically measuring absolute displacement. In the first detection system a step motor is controlled to drive an analyzer to trace synchronously the displacement being measured by comparison of the magnitude of the intensity of two orthogonal light beams and then the number of control pulses from the step motor becomes a value of the displacement measured; and by comparison with the magnitude the intensity of a plurality of light beams with phase difference from a plurality of light paths in the second polarized light detection system the section of system operation is ascertain and consequently the absolute displacement is detected and measured.

Abstract: A method of characterizing the outermost material on an article manufactured by deposition or removal of material from its surface, which requires no prior knowledge of the composition of the article.

Abstract: Described are systems and methods for orienting a semiconductor wafer during semiconductor fabrication with the aid of an optical alignment system, the semiconductor wafer having an alignment mark with regular structures, on the basis of which the position of the semiconductor wafer can be determined.

Abstract: Disclosed is a portable fluorescence correlation spectroscopy instrument that includes an excitation source, at least one of a light focusing element positioned to receive light emitted by the excitation source, a detector for detecting light, the detector positioned to receive light emitted by a sample excited by the excitation source, and a correlator coupled to the detector, the correlator for processing data received at the detector and providing data including autocorrelation data, crosscorrelation data, or a combination thereof.

Abstract: A color measurement instrument includes a housing and illuminators, a two-dimensional photodetector array, and an optics system within the housing. A UV filter wheel closes the housing to prevent contaminants from entering the housing. The filter wheel supports UV filters and non-UV glass that can be selectively aligned with the illuminators. The photodetectors can be read in parallel, and each photodetector includes a unique spectral filter. The optics system delivers light from the sample target area equally to each of the photodetectors.

Abstract: Provided are methods and devices for measuring the dispersion along a line of sight, using spectral narrow-band light sources with multiple wavelengths, and atmospheric structures, both in the absorptive (imaginary refractive index) and in the dispersive region (real refractive index).

Abstract: The invention concerns high sensitivity light scattering detection and its application to evaporative light scattering detection in liquid chromatography. The exemplary embodiment includes a detection cell to accept particles suspended in a gas stream and permit a polarized light beam to pass through a trajectory of the particles and gas stream. A sample light detector is disposed to detect light scattered in the detection cell. A light trap accepts the polarized beam after it passes through the detection cell. The light trap includes an elongated housing through which the polarized beam passes, and light absorptive material within the elongated housing. An absorptive filter is aligned such that the angle of incidence of the light beam upon the filter approximates Brewster's angle and the electric field vector of the beam is aligned with the plane of incidence between the beam and the filter. Other embodiments of the invention provide increased light collection.

Abstract: A gas sensor arrangement comprises a first half-shell mateable with a second half-shell. The first half-shell has a detector receiving opening and radiation source receiving apertures. A gas measuring chamber is formed between the first half-shell and the second half-shell. The gas measuring chamber extends between the detector receiving opening and the radiation source receiving apertures. Concave mirrors are arranged around the radiation source receiving apertures. The concave mirrors are formed by inner surfaces of the first and second half-shells. Tubes extend from the concave mirrors to the detector receiving opening. The tubes are formed by the inner surfaces of the first and second half-shells. The inner surfaces are coated with a reflective material.

Abstract: An optoelectronic detector system is for generating a plurality of periodic, phase-shifted scanning signals from the scanning of a periodic fringe pattern. The fringe pattern extends in a detection plane with fringe-pattern period P in a fringe-displacement direction. The detector system is made up of a plurality of detector elements, the geometrical shape of the detector elements being selected such that a defined filtering of unwanted harmonics from the scanning signals thereby results. Within one fringe-pattern period P, a total of N detector elements of the same geometrical shape are arranged one immediately after the other in measuring direction x.

Abstract: Devices and methods of accurately determining optical wavelengths, such as the Bragg wavelengths of an FBG sensor array. Wavelength-swept light having a characteristic spectrum is swept over a bandwidth and is applied to an interference filter. The interference filter produces an optical spectrum having one or more reference peaks that are identifiable because of the characteristic spectrum. The optical spectrum is converted into electrical signals having at least one electrical signal that is identifiable because of the characteristic spectrum. The identifiable electrical signal is used by a signal processor as an absolute, high accuracy wavelength reference. Temperature compensation or temperature stabilization can compensate the characteristic wavelength. Fiber Bragg sensor systems can use the wavelength reference to determine the Bragg wavelength of FBG elements. The characteristic spectrum can be imparted by the light source or an optical element such as a transmission line filter.

Abstract: An optical image measuring apparatus capable of effectively obtaining a direct current component of a heterodyne signal which is composed of background light of interference light is provided.

Abstract: Disclosed herein is a method and apparatus for simultaneously measuring a displacement and angular variations. The method and apparatus of the present invention allows light radiated from a single light source to be placed along a light axis so as to simultaneously measure a distance (displacement) and angular variations that are different physical quantities, so that the displacement and angular variations of the measuring device of a precision measuring apparatus or machining device of a machine tool moved by a stage can be simultaneously measured without an Abbe error.

Abstract: Two common-path interferometers share a measuring cavity for measuring opposite sides of opaque test parts. Interference patterns are formed between one side of the test parts and the reference surface of a first of the two interferometers, between the other side of the test parts and the reference surface of a second of the two interferometers, and between the first and second reference surfaces. The latter measurement between the reference surfaces of the two interferometers enables the measurements of the opposite sides of the test parts to be related to each other.

Abstract: In general, in one aspect, the invention features a method that includes directing a first measurement beam along a first path contacting a measurement object to determine a first interferometric phase related to a position of a measurement object, directing a second measurement beam along a second path contacting the measurement object to determine an second interferometric phase related to the position of the measurement object, and determining a contribution to the first interferometric phase due to perturbations in refractivity along the first path based on the second interferometric phase.

Abstract: A frequency-shifting interferometer gathers intensity data from a set of interference patterns produced at different measuring beam frequencies. A periodic function is matched to the intensity data gathered from the set of interference patterns over a corresponding range of measuring beam frequencies. Localized correlations involving phase offsets between the interfering portions of the measuring beam are used to inform a determination of a rate of phase change with measuring beam frequency corresponding to the optical path length difference between the interfering beam portions.

Abstract: A device and a method for wavefront measurement of an optical imaging system, and a microlithography projection exposure machine that is equipped with such a device. The device has a wavefront generating unit that includes an optical element (1) with an object-side periodic structure (2), and a light source unit (20,21) for illuminating the object-side periodic structure with the aid of a measuring radiation. The device also has a detector unit that is arranged on the image side of the imaging system to be measured and that includes an optical element (3) with an image-side periodic structure, and a detector element (52, 52a, 52b) for detecting an overlay pattern of the imaged object-side periodic structure and image-side periodic structure.

Abstract: A wavefront measurement system includes a source of electromagnetic radiation. An imaging system directs the electromagnetic radiation at an object plane that it uniformly illuminates. A first grating is positioned in the object plane to condition the radiation entering the input of a projection optic. A projection optical system projects an image of the first grating onto the focal plane. A second grating is positioned at the focal plane that receives a diffracted image of the object plane to form a shearing interferometer. A CCD detector receives the image of the pupil of the projection optical system through the projection optical system and the second grating that forms a fringe pattern if there are aberrations in the projection optical system. Phaseshift readout of fringe pattern can be accomplished by stepping the first grating in a lateral direction and reading each frame with the CCD detector.

Abstract: The invention concerns a method and a reference object for the verification and identification of a measuring device for measuring the spatial position of one or several points situated in the measuring volume (9) of the measuring device, whereby the measuring device is calibrated, according to which calibration a mathematical model is calculated which makes it possible to determine the spatial position of a point perceived by the measuring device, whereby a reference object (1) with predetermined dimensions is provided in the measuring volume (9), and, next, the position of several points of this reference object (1) is determined by means of the measuring device, whereby the mutual situation of the thus determined position of the points of the reference object (1) is calculated and compared to the actual dimensions of the reference object (1) and, on the basis of the thus established deviations between the measured mutual position of the points of the reference object (1) and the actual dimensions of the re

Abstract: There is provided an optical projection system for projecting an image onto an object that is being manufactured and/or inspected. The system includes an image-projecting device, a target-locating device for determining the orientation of the image-projecting device relative to the object, and an image-rendering device for rendering the image that is projected onto the object. The target-locating device advantageously comprises a camera that locates at least one target in mechanical communication with the object to determine the orientation of the image-projecting device relative to the object. The image-rendering device advantageously stores a three-dimensional representation of the object that is converted into a two-dimensional image that is projected upon the object. The image projected upon the object is advantageously used during assembly and/or inspection of the object.

Abstract: An image measuring method comprises making no stop of an imaging means relative to a measurement stage at measurement positions (MP1-MP3), and capturing instantaneous images to acquire information required for measurement. A first direction to a measurement position (MP1) to be measured next and a second direction from the measurement position (MP1) to a next measurement position (MP2) form an angle therebetween. If this angle exceeds a certain angle, an overshoot path is formed at a location beyond the measurement position (MP1) in the first direction. The larger the angle formed between the first direction and the second direction, the lower the measurement speed at the measurement position (MP1) is made.

Abstract: An inspection system for inspecting a wafer and an inspection method thereof are provided. The inspection system includes a rotating means for turning and arranging a wafer to an inspection position, an angle measuring means for measuring a rotational angle used by the rotating means to rotate to the inspection position, an inspection apparatus for acquiring inspection data associated with the wafer, and a controller for determining an amending angle from the rotational angle and for amending the inspection data in accordance with the amending angle to calculate amended inspection data, wherein the amended inspection data reflects a state of the wafer on the rotating means.

Abstract: A networked system for enabling geographically-spaced common-brand users to publish locale-specific, content-controlled messages is provided. The networked system comprises an online publishing portal providing selective access to pre-constructed, digital, plate-ready macrotemplates. A dynamic document server stores the macrotemplates and authorizes selective access thereto based upon user-supplied credentials. The user, having authenticated credentials, may access a select macrotemplate, which necessarily comprises a plurality of digital, plate-ready microtemplates, including at least one restricted access template and at least one open access template. Authorized users may edit a select microtemplate as dictated by the user's level of authorization. The user may thus send the content-controlled digital, plate-ready file to a publisher for publishing information or messages compiled upon the macrotemplate.

Abstract: In this invention, when a printer driver uses data obtained by referring to a table, the printer driver searches a first table of two, first and second tables to obtain a search condition of the second table. The printer driver searches the second table using the obtained search condition to obtain required data. When another search condition is added, the search condition is added to the first able, and data corresponding to the added search condition is added to the second table.

Abstract: In a data processing system in which data to be processed is managed as processing-object data, and the processing-object data is processed in response to a designation, there are provided: data management means for managing the processing-object data together with processing-object attribute information indicative of an attribute thereof; processing designation means for designating a processing with respect to the processing-object data through a dialog performed with the user; processing execution means for executing a processing of the processing-object data in response to a designation performed by the processing designation means; and first processing result forecasting means for executing, when the dialog is performed, a forecast on a result of the processing by comparing processing-subject attribute information, which indicates an attribute of a processing to be executed by the processing execution means, with the processing-object attribute information, and for outputting to the user forecast notific

Abstract: A system for the remote retrieval of at least one document sent by facsimile transmission using a repository server for storing at least one document for a recipient at a location using a remote system connected to the system. Security apparatus for the system includes apparatus, such as a smartcard, to identify, to validate, and to locate a remote user of a remote system connected to the system when the user is connected to the repository server for retrieving at least one document stored by the repository server. Upon validation of identification of a user, any or all documents may be retrieved by a user.

Abstract: A printer cable that is configured for coupling to a printer having an enclosure and a printer port. The printer cable includes a first connector for connecting to the printer port and a second connector for coupling to a host device (e.g., a personal computer (PC)). The printer cable includes a printer formatter for providing formatting services to the printer via the first connector. Since the printer formatter is integrated into the printer cable, the printer formatter is external to the printer enclosure and is easily removable and configurable by a user.

Abstract: A publication is distributed by an automated publication delivery system. Activity around a physical location of the automated publication delivery system is monitored. In response to detection of an increased activity level around the physical location of the automated publication delivery system, additional copies of the publication are printed for distribution. For example, the automated publication delivery system is a kiosk and the publication is a newspaper. Monitoring is performed, for example, using a microphone to monitor noise level, an optical sensor to detect movement near the automated publication delivery system, and/or a motion detector to detect movement near the automated publication delivery system.

Abstract: To collect optimal data to an image processing capacity of an output section in an image processing apparatus. Therefore, a method of the present invention includes the steps of: selecting a resource from among conditional branch resources linked in analyzed document information on the basis of an image processing capacity value of a printer engine; and acquiring the selected resource from a server device, analyzing link information in the document information described in the structured description language.

Abstract: The invention relates to the data transfer method, the image processing method, the data transfer system and the image data processor for transferring digital data, especially for transferring image data. The invention has an object to provide the data transfer method, the image processing method, the data transfer system and the image data processor, wherein the compression ratio is changed corresponding to the transfer rate between connecting devices and the lack of image is avoided. The detecting means detects the data transfer capability of the transmission channel and the transfer end, and the control means changes the compression ratio of the digital data corresponding to the data transfer capability. Subsequently, the compressing means compresses the digital data based on the changed compression ratio and the transfer means transfers the compressed digital data to the transfer end.

Abstract: Reduced image data of images recorded in a memory card of a digital camera is transmitted from the digital camera to a portable phone. In the portable phone, while viewing the photographs one by one, a print order instruction operation is performed on the desired images. The print order information is transmitted from the portable phone to the digital camera, and the information is recorded as a print order file into the memory card in the digital camera.

Abstract: A system and method for communicating commands and data to a printer and pre- and post-processors through a link using different protocols. In the exemplary embodiment, UP3I finishing instructions for a print file are specified in a MO:DCA Form Definition and processed by a print server on a host computer. Print commands are generated by the host computer and transmitted to a printer using the Intelligent Printer Data Stream (IPDS) Architecture. The processor within the printer receives and processes the UP3I pre- and post-processor commands received via the IPDS communications link and generates commands on a separate communications channel according to the Universal Printer Pre- and Post-Processing Interface (UP3I) for transmission to the pre- and post-processors. Status reported by the pre- and post-processors according to the UP3I™ specification are received by the printer and transmitted to the host computer.

Abstract: Xerox Docket No. D/A0037Q Document authentication is accomplished by acquiring document image data, generating a set of features of the document, and generating an assist channel that includes information on how to generate the set of features. The set of features and the assist channel are digitally signed and then append to the document. Document verification is accomplished by acquiring document image data and verifying the signature. If the signature is valid, a set of features of the document is generated using information contained in the assist channel appended to the document. The generated set of features is then compared to the set of features appended on the document. If the sets do not match, the document is determined to have been altered sometimes after the assist channel was appended to the document, i.e., the document is not genuine. Otherwise, the document can be considered to be genuine.

Abstract: Together with an image forming apparatus, a method and a control program which can be applied to the image forming apparatus are disclosed in an embodiment of the invention. The image forming apparatus is an image forming apparatus for printing data whose printing has been requested from a client apparatus via a network. The image forming apparatus has: identifying means for identifying a text portion and an attached file with respect to E-mail transmitted from the client apparatus, recognizing means for recognizing control data which can be disclosed in the text portion of the E-mail and control data which can be enclosed in the attached file identified by the identifying means, and control means for controlling a printing process in accordance with a recognition result of the recognizing means showing whether at least either the text portion or the attached file identified by the identifying means includes the control data or not.

Abstract: A host computer is connected to a plurality of printers via an IEEE1394 bus. To make these printers print an identical image, the host computer assures a communication channel. The host computer then broadcasts print data to the printers to make them print images. In this case, the host computer starts transmission after it confirms that all the printers are ready to print and to receive print data. Upon receiving a busy response from any printer, the host computer pauses data transmission.

Abstract: According to this invention, a document processing method of documenting image data obtained by double-sided scanning of an original containing a single-sided printed part and a double-sided printed part includes a blank determination step of determining on the basis of the image data whether the lower surface of an original is blank, and a documentation step of, when the lower surface is determined in the blank determination step to be blank, saving image data corresponding to the upper surface of the original as document information together with a single-sided printing attribute, and when the lower surface is determined in the blank determination step not to be blank, saving image data corresponding to the two surfaces of the original as document information together with a double-sided printing attribute.

Abstract: A print drive is present in an electronic pre-press workflow that includes a raster image processor (“RIP”) and an output device to receive, store, combine and transmit raster data processed by the raster image processor. A prepress imposition scheme is created at the front end and processed by the RIP. Prepress imposition parameters are used to generate a press sheet template image, which is transmitted to the print drive. The print drive is capable of applying the press sheet template to page raster data on demand to form a multi-page press sheet assembly so that raster images of individual pages remain independent. Among other benefits, this improves electronic prepress workflow by eliminating the need to generate combined raster images of multi-page press sheets to correct or modify a portion of the assembly.