Patents by Inventor Jagdish C. Tandon
Jagdish C. Tandon has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 8368002Abstract: A photosensitive apparatus including a full width array of photosensors and a first photosensor chip. The first photosensor chip including a linear array of photosensors having a plurality of pixels arranged in a long direction and a linear variable filter adapted to transmit at least ten unique bandwidths of wavelengths of light along a length of the linear variable filter where the linear variable filter is fixedly secured to the linear array. Each respective pixel receives a unique bandwidth of wavelengths of light as a light passes through the linear variable filter and the length is aligned with the long direction. The full width array of photosensors is arranged perpendicular to a process direction of a printing device.Type: GrantFiled: October 15, 2009Date of Patent: February 5, 2013Assignee: Xerox CorporationInventors: Paul A. Hosier, Jagdish C. Tandon, Josef E. Jedlicka, Paul S. Bonino
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Patent number: 7990528Abstract: A photosensitive chip, including: at least one set of photosensors substantially aligned in a Y direction; and a layer of non-transmissive material including a plurality of openings. Each opening in the plurality of openings includes a respective center line and overlaps only a portion of a respective photosensor so that only the portion of the respective photosensor is photosensitive. The respective center lines for openings for each set of photosensors are not collinear in the Y direction. In an example embodiment, the plurality of openings includes at least one row of openings substantially aligned in an X direction, orthogonal to the Y direction. In an example embodiment, each opening has an equal width in an X direction, orthogonal to the Y direction.Type: GrantFiled: September 29, 2009Date of Patent: August 2, 2011Assignee: Xerox CorporationInventors: Paul A. Hosier, Jagdish C. Tandon
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Publication number: 20110089316Abstract: A photosensitive apparatus including a full width array of photosensors and a first photosensor chip. The first photosensor chip including a linear array of photosensors having a plurality of pixels arranged in a long direction and a linear variable filter adapted to transmit at least ten unique bandwidths of wavelengths of light along a length of the linear variable filter where the linear variable filter is fixedly secured to the linear array. Each respective pixel receives a unique bandwidth of wavelengths of light as a light passes through the linear variable filter and the length is aligned with the long direction. The full width array of photosensors is arranged perpendicular to a process direction of a printing device.Type: ApplicationFiled: October 15, 2009Publication date: April 21, 2011Applicant: XEROX CORPORATIONInventors: Paul A. HOSIER, Jagdish C. TANDON, Josef E. JEDLICKA, Paul S. BONINO
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Publication number: 20110075157Abstract: A photosensitive chip, including: at least one set of photosensors substantially aligned in a Y direction; and a layer of non-transmissive material including a plurality of openings. Each opening in the plurality of openings includes a respective center line and overlaps only a portion of a respective photosensor so that only the portion of the respective photosensor is photosensitive. The respective center lines for openings for each set of photosensors are not collinear in the Y direction. In an example embodiment, the plurality of openings includes at least one row of openings substantially aligned in an X direction, orthogonal to the Y direction. In an example embodiment, each opening has an equal width in an X direction, orthogonal to the Y direction.Type: ApplicationFiled: September 29, 2009Publication date: March 31, 2011Applicant: XEROX CORPORATIONInventors: Paul A. HOSIER, Jagdish C. TANDON
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Patent number: 7706030Abstract: An apparatus for illuminating a document includes an optical element formed of a light-transmissive material of a predetermined refractory index that defines a curved entry surface and an exit surface opposite the entry surface in which light enters the optical element via the entry surface and light exits the optical element via exit surface. A first substantially parabolic surface is defined between a first edge of the entry surface and first edge of the exit surface and a second substantially parabolic surface is defined between a second edge of the entry surface and a second edge of the exit surface such that the first and second substantially parabolic surface are spaced apart more at the exit surface than at the entry surface.Type: GrantFiled: April 21, 2006Date of Patent: April 27, 2010Assignee: Xerox CorporationInventors: Robert P. Herloski, Douglas E. Proctor, Jagdish C. Tandon, Pravin N. Kothari, Eric Dudley
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Patent number: 7586082Abstract: An apparatus for recording an image on a sheet comprises a linear array of light sources and an optical element for transmitting light emitted from the light sources. The optical element comprises a light-transmissive member, having an entry surface for disposal near the light sources. The entry surface defines at least one set of prisms. The optical element can further define a DCPC (dielectric compound parabolic concentrator) in cross-section. Collection optics, such as a SELFOC® lens, receives light reflected from the sheet. Each prism of the optical element defines an angle whereby light exiting the optical element is outside the acceptance angle of the collection optics.Type: GrantFiled: January 24, 2007Date of Patent: September 8, 2009Assignee: Xerox CorporationInventors: Robert P. Herloski, Jagdish C. Tandon, Douglas E. Proctor, Stephen J. Wenthe, Jr., Eugene A. Rogalski, Jr., Jeffrey L. Baniak, Paul A. Hosier
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Publication number: 20090180111Abstract: A system for detecting reflectance from an image bearing surface in a printer or electronic copier includes an illuminator array, positioned adjacent to the image bearing surface, comprising a plurality of discrete illuminator elements that are spaced in a linear arrangement; a light diffuser positioned between the illuminator array and the image bearing surface, the light diffuser being positioned with respect to the illuminator array to receive the light beams emitted by the illuminator elements and to diffuse the light beams for transmission to the image bearing surface at an incidence angle; and a linear sensor array positioned adjacent to the image bearing surface such that specular and diffuse portions of the light beams reflecting off the image bearing surface at a reflectance angle bearing are received by the sensors.Type: ApplicationFiled: January 15, 2008Publication date: July 16, 2009Applicant: XEROX CORPORATIONInventors: Jagdish C. TANDON, Robert Herloski
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Patent number: 7528997Abstract: In a system and method for streak detection in a fixed imaging array digital scanning system, redundant information regarding individual lines of a scanned image collected by multiple discrete rows or sets of scanning sensors in the imaging array are compared. Stationary obstructions in the field of view of the imaging array are detected through this comparison which would otherwise appear repeatedly reproduced as streaks or lines in the reproduced output image.Type: GrantFiled: December 22, 2003Date of Patent: May 5, 2009Assignee: Xerox CorporationInventors: Donald J. Gusmano, Jagdish C. Tandon, Paul A. Hosier
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Patent number: 7518759Abstract: In an image sensor having a plurality of photodiodes, subsets of photodiodes share a common node for signals to be sent to an amplifier. Within each subset, each individual photodiode is selected for sending signals to the amplifier by an associated selection device. The selection device is a MOS device operating in a linear region. The subset of photodiodes share a common “fill and spill” or “bucket brigade” transfer circuit to the amplifier, the transfer circuit including at least one MOS device which operates in a subthreshold region.Type: GrantFiled: April 22, 2003Date of Patent: April 14, 2009Assignee: Xerox CorporationInventors: Paul A. Hosier, Scott L. TeWinkle, Jagdish C. Tandon, Pravin N. Kothari
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Patent number: 7471327Abstract: A photosensitive imaging apparatus has a linear array of groups of photosensors. In a low-resolution scanning mode, all of the photosensors in each group act together as one large photosensor. In a high-resolution scanning mode, each photosensor in a group acts outputs image-based signals independently. In either mode, the signals output by the photosensors are transferred to one of two output lines, such as for “odd-” and “even-” positioned photosensors or groups of photosensors. The signals on the two lines can then be multiplexed to a single output line. The dual output lines enable fast signal output in either resolution mode.Type: GrantFiled: January 21, 2004Date of Patent: December 30, 2008Assignee: Xerox CorporationInventors: Paul A. Hosier, Scott L. TeWinkle, Roger L. Triplett, Jagdish C. Tandon
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Patent number: 7467879Abstract: An apparatus for scanning a document comprises a platen for supporting at least a portion of the document; a light source; and an optical element for directing light from the light source to the platen. The optical element defines a plurality of small planar surfaces, the small planar surfaces being arranged in a linear array. Light emanating from a source is reflected from one of the small planar surfaces and emerges substantially perpendicular to an exit surface.Type: GrantFiled: April 21, 2006Date of Patent: December 23, 2008Assignee: Xerox CorporationInventors: Robert P. Herloski, Jagdish C. Tandon, Douglas E. Proctor, Eric Dudley
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Patent number: 7446907Abstract: In an image sensor array, as would be used in an input scanner such as in a digital copier, an original image is moved relative to a linear array of photosites. Each photosite includes at least two wide photosensors, each of which extends substantially across the photosite along the array direction, and at least two narrow photosensors, which are arranged next to each other along the array direction. In one embodiment, the wide photosensors include primary-color filters and the narrow photosensors are clear-filtered.Type: GrantFiled: April 22, 2003Date of Patent: November 4, 2008Assignee: Xerox CorporationInventors: Paul A. Hosier, Jagdish C. Tandon, Scott L. TeWinkle
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Publication number: 20080173799Abstract: An apparatus for recording an image on a sheet comprises a linear array of light sources and an optical element for transmitting light emitted from the light sources. The optical element comprises a light-transmissive member, having an entry surface for disposal near the light sources. The entry surface defines at least one set of prisms. The optical element can further define a DCPC (dielectric compound parabolic concentrator) in cross-section. Collection optics, such as a SELFOC® lens, receives light reflected from the sheet. Each prism of the optical element defines an angle whereby light exiting the optical element is outside the acceptance angle of the collection optics.Type: ApplicationFiled: January 24, 2007Publication date: July 24, 2008Inventors: Robert P. Herloski, Jagdish C. Tandon, Douglas E. Proctor, Stephen J. Wenthe, Eugene A. Rogalski, Jeffrey L. Baniak, Paul A. Hosier
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Patent number: 6975949Abstract: A full width array spectrophotometer for full width scanning color analysis of color test targets, with one or two substantially linear elongated arrays of closely spaced multiple LED illumination sources of plural different color emissions in a multiply repeated pattern of at least three or four different colors transversely spanning a printer paper path and sequentially illuminated to illuminate a transverse band across a printed sheet moving in the paper path, and a corresponding elongated low cost light imaging bar with a parallel and correspondingly elongated array of multiple closely spaced different color sensitive (three or four rows of color-filtered) photodetectors, which imaging bar is positioned to detect and analyze light reflected from the transverse sequentially illuminated band.Type: GrantFiled: April 27, 2004Date of Patent: December 13, 2005Assignee: Xerox CorporationInventors: Lalit K. Mestha, Jagdish C. Tandon, Steven B. Bolte
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Patent number: 6961157Abstract: In an imaging apparatus such as a scanner or digital camera, a photosensitive device includes multiple linear arrays of photosensors. One of the arrays has a higher spatial resolution than other arrays. The high-resolution array is filtered to detect different portions of the color spectrum than the low-resolution arrays.Type: GrantFiled: May 29, 2001Date of Patent: November 1, 2005Assignee: Xerox CorporationInventors: Jagdish C. Tandon, Keith T. Knox, Robert R. Buckley
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Patent number: 6955989Abstract: The present disclosure relates that by modifying chip die dicing methodology to a U-groove profile from a V-groove profile by modifying the second etch step to be a dry etch instead of a wet etch results in a direct cost savings by eliminating a more expensive process step, as well as the need for stripping the developed photoresist layer. Furthermore, going to a U-groove profile accomplishes additional indirect and greater cost savings resulting from increased process throughput, improved yield, and reduced metal layer defects.Type: GrantFiled: November 30, 2001Date of Patent: October 18, 2005Assignee: Xerox CorporationInventors: Alain E. Perregaux, Paul A. Hosier, Josef E. Jedlicka, Nicholas J. Salatino, Jagdish C. Tandon
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Patent number: 6927381Abstract: A photosensitive imaging device for recording images across the entire visible spectrum includes a set of photosensors which have a peak response around the orange part of the spectrum, about 600 nm. The peak response is obtained by combining responses of, in one case, photosensors associated with a filter which admits red or infrared wavelengths and longer and photosensors associated with a filter which admits orange wavelengths and longer. In another case, the photosensor is structured to attenuate longer wavelengths, which, in combination with a filter which admits orange and longer wavelengths, can simulate a peak behavior around the orange part of the spectrum.Type: GrantFiled: September 5, 2003Date of Patent: August 9, 2005Assignee: Xerox CorporationInventors: Paul A. Hosier, Jagdish C. Tandon, Josef E. Jedlicka, Gaurav Sharma, Alain E. Perregaux, Robert P. Herloski
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Publication number: 20040212858Abstract: In an image sensor array, as would be used in an input scanner such as in a digital copier, an original image is moved relative to a linear array of photosites. Each photosite includes at least two wide photosensors, each of which extends substantially across the photosite along the array direction, and at least two narrow photosensors, which are arranged next to each other along the array direction. In one embodiment, the wide photosensors include primary-color filters and the narrow photosensors are clear-filtered.Type: ApplicationFiled: April 22, 2003Publication date: October 28, 2004Applicant: Xerox Corporation.Inventors: Paul A. Hosier, Jagdish C. Tandon, Scott L. TeWinkle
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Publication number: 20040212850Abstract: In an image sensor having a plurality of photodiodes, subsets of photodiodes share a common node for signals to be sent to an amplifier. Within each subset, each individual photodiode is selected for sending signals to the amplifier by an associated selection device. The selection device is a MOS device operating in a linear region. The subset of photodiodes share a common “fill and spill” or “bucket brigade” transfer circuit to the amplifier, the transfer circuit including at least one MOS device which operates in a subthreshold region.Type: ApplicationFiled: April 22, 2003Publication date: October 28, 2004Applicant: Xerox CorporationInventors: Paul A. Hosier, Scott L. TeWinkle, Jagdish C. Tandon, Pravin N. Kothari
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Patent number: 6690471Abstract: An improved and lower cost color spectrophotometer, especially suitable for on-line color printer color control systems, incorporating a low cost commercial imaging chip, which normally only forms part of a three row, three color, document imaging bar used for imaging documents in scanners, digital copiers, or multifunction products, having multiple photo-sites with at least three different color filters in three rows. This multiple photo-sites chip may be modified to also provide unfiltered photo-sites. This spectrophotometer may have a substantially reduced number of different LED or other spectral illumination sources, one of which may be for white light, yet provide multiple spectral data outputs from the differently filtered photo-sites being simultaneous illuminated by the light reflected from a color test target area which is being sequentially illuminated by the respective limited number of LEDs, enabling broad spectrum information and color control.Type: GrantFiled: February 28, 2003Date of Patent: February 10, 2004Assignee: Xerox CorporationInventors: Jagdish C. Tandon, Lingappa K. Mestha