Abstract: A scanhead of an imaging apparatus for providing image illumination uniformity for imaging of a media sheet, and a method thereof, are disclosed. The scanhead includes a lens, a lens shading plate and a sensor array. The lens is capable of receiving light reflected from the media sheet and focusing the received light. The lens shading plate is capable of assuming a lens shading plate position of a plurality of lens shading plate positions between the lens and the sensor array for receiving the light focused by the lens. The lens shading plate, on assuming the lens shading plate position, is capable of adjusting the light received from the lens for focusing the light onto the sensor array, thereby providing image illumination uniformity, for the imaging of the media sheet.

Abstract: A method for uniformly illuminating a predetermined scan line position on a media sheet containing an image includes defining an optical path from a media sheet to a sensor, selecting a predetermined scan line position on the media sheet, and emitting a light beam from a light source whereby a portion of the light beam illuminates a first portion of the predetermined scan line and a portion of the light beam is reflected from a reflector to illuminate a second, opposed portion of the predetermined scan line position. A method for imaging a scan line on a media sheet includes these steps and also collecting at least a portion of the light beam reflected from or transmitted through the media sheet to image the portion of the media sheet defined by the predetermined scan line position. Still further, an optical imaging module is provided for accomplishing the described method.

Abstract: A scanner includes a scan bar and a calibration strip. The scan bar has perpendicular fast-scan and slow-scan axes. The scan bar has an image sensor plane and includes a substantially linear array of sensor elements substantially aligned along the fast-scan axis. A first method for calibrating the scan bar includes imaging the calibration strip to the image sensor plane of the scan bar wherein the imaging is out of focus substantially-along the slow-scan axis. The first method also includes obtaining a calibration reading of the sensor elements from the imaging of the calibration strip. A second method includes imaging the calibration strip to the image sensor plane of the scan bar wherein the imaging is optically widened substantially-along the slow-scan axis. In a third method, the imaging is optically widened substantially-along the slow-scan axis using a cylindrical lens having an imaging-widening axis.

Abstract: A scanning device for simplex and duplex scanning. The device may include a scan head for capturing content appearing on a page; a substantially C-shaped first scan path for simplex scanning, the first scan path adapted to guide the page relative to the scan head for scanning a first side of the page; a second scan path for duplex scanning, the second scan path adapted to guide the page relative to the scan head for scanning a first side of the page and a second side of the page; a path diverter, the path diverter adapted to direct the page to the first path or the second path; and a controller for controlling the first and second scan paths and the diverter. The second scan path forms a loop for moving the first and second sides of the page so that each is temporarily disposed adjacent the scan head.

Abstract: A scan module including an image sensor defining a scan field, at least one lamp positioned to illuminate at least a portion of the scan field, and a second light source positioned to provide illumination for the portion of the scan field.

Abstract: The present application is directed to embodiments for moving a media sheet within a scanning device. The methods include moving the media sheet through a separation mechanism that prevents multiple media sheets from being moved simultaneously along the media path. Further, a buckle is formed in the sheet at a point upstream from a scanner. The buckle acts as a buffer to absorb any load release that could occur as the media sheet exits the separation mechanism. The load release could cause a change in the velocity of the media sheet as it moves across the scanner.

Abstract: A scanner calibration strip medium is described which includes at least one of a plurality of text symbols and a plurality of halftoned non-text images. A scanner is described which includes a scan bar and a scanner calibration strip medium scannable by the scan bar. The calibration strip medium includes a plurality of text symbols having text pixels and a plurality of halftoned non-text images having halftoned non-text pixels. A method for segmenting a scanned document image into text symbols and halftoned non-text images is described which uses a scanner calibration strip medium which includes a plurality of text symbols having text pixels and a plurality of halftoned non-text symbols having halftoned non-text pixels, wherein the calibration strip medium has a known pixel classification including which pixels of the calibration strip medium are text pixels and which pixels of the calibration strip medium are halftoned non-text pixels.

Abstract: A detachable transparent plate for a scan head assembly in a document scanning system that allows an operator to detach the transparent plate from the scan head assembly located above a media feed path to clean a top face of the transparent plate and easily reattach it to the scan head assembly. The scan head assembly has an optical system and a sealing member detachably mounted to a bottom end of the optical system. The transparent plate is received and supported by the sealing member and defines a portion of a bottom surface of the sealing member. The sealing member is detachable from the bottom end of the optical system to allow an operator access to the top face of the transparent plate of the sealing member for cleaning the top face of the transparent plate.

Abstract: A method for adjusting a controller of a scanner includes obtaining a scan of a predefined image. The method further includes moving the sensor-element signals of the control signal pattern generated by the controller earlier in the pattern by at least one unit and obtaining an additional scan. The obtaining and moving are repeated until a comparison of a latest additional scan to the image is worse than a comparison of a second-latest additional scan to the image. Another method obtains a noise-reducing heuristic which modifies a time parameter of a sensor-element signal. A set of repeated scans of a same scan line is obtained, noise is measured there from, the time parameter is modified by one predetermined unit, and the process repeats until the noise measured from the latest set of repeated scans is worse than that from the second-latest set of repeated scans.

Abstract: A method for providing a visible reference marker on a scanning unit for orienting an item to be scanned or copied includes the steps of emitting a light from a light source, guiding the light to a scanning unit having a contact glass scanning surface, and redirecting the light to define an illuminated reference marker substantially adjacent to the contact glass. A reference marker assembly for accomplishing that method is provided, including a light source, a waveguide for guiding light emitted from the light source to a scanning unit having a contact glass, and a redirector for redirecting the light to define an illuminated reference marker adjacent to the contact glass, for orienting an item to be copied or scanned. The light source may be a light emitting diode, and the redirector may be a light diffuser for redirecting the collected light to define an illuminated reference marker adjacent to the contact glass.

Abstract: A scanning system for generating an image includes a scanning device configured to receive light reflected from a document and to output a signal corresponding to the received light to collect image data for use in generating an image. An automatic document feed system is configured to move the document from a position upstream of the scanning device toward a position downstream of the scanning device along a document feed path in proximity to the scanning device to allow the scanning device to receive light reflected from the document. A processor includes logic that compensates for changes in document movement past the scanning device using document motion data to reduce motion error induced image defects.

Abstract: A system for saving and retrieving job settings comprising a multifunction document management system and a settings form including a machine recognizable portion printed thereon, wherein the machine recognizable portion includes data indicative of at least one user-selected job setting and wherein the machine recognizable portion is readable by the multifunction document management system.

Abstract: Methods of identifying the location and dimensions of a contaminant particle on a calibration strip comprise imaging a calibration strip comprising a plurality of channels and a plurality of pixel columns. The method also includes generating a normalized local average pixel intensity value and locating a contaminant particle in a pixel column by comparing the intensity of an individual pixel in the pixel column to the normalized local average pixel intensity value. An intensity value of an individual pixel less than a predefined limit set below the normalized local average pixel intensity value corresponds to a location of a contaminant particle. The method further includes identifying the number of adjacent pixels in a pixel column less than a predefined limit set below the normalized local average pixel intensity value.

Abstract: A scanning or copying system can include imaging elements and one or more system processors that are programmed or adapted to perform image processing methods and algorithms on image data, and in some instances, to enhance the image. Image data is acquired using imaging elements. Some imaging elements may have overlapping or rotated fields of view or employ differing resolutions. For each imaging element, its output is recombined together with the output of one or more other imaging elements. To perform the recombination, the system can extract features in an overlapping region and match these features in multiple images. In some instances, the features matched can be edges. Alternatively, the recombination can be performed by positioning each subimage with respect to a larger image through image matching and location techniques. Parameters from the recombined image can be extracted and these parameters can be used to correct for geometrical and spatial distortions and thereby enhance the image.

Abstract: A method is provided for compensating two-dimensional images for non-uniformity variations in the illumination of a document, or a scene, that is acquired by a digital camera. The invention can include a printer and/or a personal computer to perform some or all of the compensation calculations, if desired. The present invention captures initial image data, determines a region or area of that data having substantially, or somewhat, uniform pixel intensities and uses that as a background or border region. This border data is used to calculate correction data to correct or compensate the non-border pixel values for non-uniformities in the illumination of the image when it was first acquired, without needing a separate reference frame.

Abstract: Methods of identifying the location and dimensions of a contaminant particle on a calibration strip may be used to compensate for contaminant particles on a calibration strip. A method of locating a contaminant particle on a calibration strip comprises imaging a calibration strip comprising a plurality of channels arranged in rows and a plurality of pixel columns, wherein each channel comprises a plurality of horizontally adjacent pixels, and each pixel column comprises pixels from a plurality of channels. The method also includes generating an average pixel intensity value by normalizing the channels and locating a contaminant particle in a pixel column by comparing the intensity of an individual pixel in the pixel column to the average pixel intensity value. An intensity value of an individual pixel less than a predefined limit set below the normalized local average pixel intensity value corresponds to a location of a contaminant particle.

Abstract: A method of estimating light output of a lamp in a scanner prior to the lamp being fully warmed-up. The method includes measuring a spectral characteristic of light emitted by a lamp in a scanner at a time t0 prior to the lamp being fully warmed-up and estimating the light output of the lamp at a time t1 based on the measured spectral characteristic, wherein t1 is greater than t0. A method of scanning, as well as a scanning apparatus is also provided.

Abstract: A method and system for combining a first image and a second image where the first image and second image include an overlap portion. The method includes selecting a first stitch location for a line of pixels, calculating a first line edge value for the first stitch location, selecting a second stitch location, calculating a second line edge value for the second stitch location and comparing the line edge values. The final stitch location is selected based upon the line edge values. A second embodiment provides a method and system for selecting an algorithm for combining a first image and second image including an overlap portion. The method includes applying a first stitching algorithm to the overlap portion, calculating an overlap edge value, and comparing the overlap edge value to a predetermined threshold. If the overlap edge value is greater than the threshold, a second stitching algorithm is applied.

Abstract: Methods for automatically grading multiple choice tests using test question sheets marked by a test-taker. Image processing algorithms automatically recognize the circled answer selections on the test question sheets. Using the invention multiple choice tests may be scanned and graded automatically without the use of bubble sheets, thereby simplifying and reducing the cost of testing.

Abstract: To reduce errors introduced by a scanner, an unmarked, digital master document may be generated and stored in digital form so that subsequent scanning of the document is unnecessary to place it in digital form for comparison to a marked version of the document. Additionally, regions or fields, rather than the entire digital master document, may be individually created, stored, and subsequently used for comparison to corresponding portions of a marked version. Further, test targets or patterns may be inserted into the content of a digital master document. Characteristics of image quality degeneration and distortion can be extracted from printed versions of the test targets or patterns and used to effect closed loop control to digitally reduce image quality degeneration caused by the scanner.