Xerox Corporation

Ned J Seachman

Joseph P Taillie

Jagdish C Tandon

William L Lama

James C Stoffel

Alain E Perregaux

Kevin Michael Carolan

LeRoy A Baldwin

John D Hower, Jr

Edgar E Price

Robert Brutovski

Leon C Williams

James D Rees

Robert Paul Herloski

Charles J Kramer

Gary A Dir

William Kingsley

Clark I Bright

Jack R Hauber

A system and method electronically determines an edge of a copy substrate to be printed on. A copy substrate is inserted between a linear light source array and a linear sensor array and a light segment of the linear light source array is illuminated. An edge location of a shadow created by the copy substrate intersecting a light path between the illuminated light segment and the linear sensor array is measured, and a location of the edge of the copy substrate is calculated based on the measured shadow location. A second light segment of the linear light source on an opposite side of an expected copy substrate edge position of the light segment can also be illuminated, and a second edge location of a shadow created by the copy substrate intersecting a light path between the illuminated second light segment and the linear sensor array can be measured wherein this second measurement can be used with the first to calculate a location of the edge of the copy substrate. Alternatively, the calculated location can be used to determine a light segment of the linear light source which corresponds to the calculated location. This determined light source is illuminated and the shadow measured. The new measurement is used to calculate the edge of the copy substrate.

Copy substrate edge electronic registration system for a reprographic system

An illumination system includes a platen upon which a document rests. The document is irradiated directly by light from a light source and indirectly by light reflected from an opposing reflector. The light reflected from the document passes through an opening or slit in the illumination registration device. The opposing reflector and light source are attached to an illumination system registration device. The illumination system registration device includes an opposing reflector locating surface and a lamp locating feature for providing proper registration and alignment between the light source and the opposing reflector. The opposing reflector locating surface is shaped in the same shape as the opposing reflector.

Reflector and light source registration device for a document illuminator

A platen cover assembly of an image processor includes a light source array that has a plurality of light sources arranged in a two-dimensional light source array, and a translucent white material covering at least a side of the light source array that faces a platen of the image processor. When a document is placed on a platen and covered by the platen cover assembly, a first scan of the platen is performed with a document illuminator of the digital image processor deactivated to sense light from exposed light sources of the light source array. The document illuminator is then activated, and a second scan is performed to obtain image data from the document. The obtained image data is then processed based on the size, location and/or orientation of the document, as determined from positions of the light sources detected during the first scan.

Methods and apparatus for detecting a document on a platen

A raster input scanner, and a reproduction system that uses that input scanner, having multiple depths of focus. The raster input scanner includes a light source for emitting light toward an image bearing member and at least two lens arrays, with the ability to selectably position any one lens array in optical conjugate relationship between the image bearing member on a transparent platen and a photosensor array. One of the lens arrays has a first depth of focus, while the other lens array has a second depth of focus that is different than the first depth of focus. Beneficially, the input scanner responds to an operator selection of which depth of focus is to be used to image a given image bearing member.

Dual depth of focus imaging system

Copy substrate edge electronic registration system for a reprographic

A system and method digitally scans a document using a high reflectance mode and a low reflectance mode. Initially, a platen cover provides a low reflectance background around the document and the scanner scans the low reflectance background and document to determine an edge of the document or to retrieve other image characteristics of the document. Subsequently, the platen cover changes so as to provide a high reflectance background around the document. The scanner then scans the high reflectance background and the document and produces digital image data relating to an image on the document.

Platen cover for a digital document scanner with electrically switchable

A system for calibrating a digital scanner utilizes a calibration strip having reference information printed thereon and a machine readable encoded tag having characteristic values corresponding to the calibration strip reference information encoded thereon. A scanning system scans the calibration strip and the machine readable encoded tag to generate image data corresponding to scanned-in reference information and data corresponding to scanned-in characteristic values of the reference information. The correction values are then derived from the generated image data and the decoded characteristic values that accurately describe the desired image data.

Apparatus and method for calibrating a digital scanner

In an optical/electrical imaging system, optical depth of focus corrections are accomplished electronically. A plurality of defocus states of the optical system are measured and/or determined and image restoration coefficients corresponding to each of these states are stored. The state of defocus of the imaging system is then determined by deriving an image from a target having known characteristics, which are then correlated to determine a state of defocus. A microprocessor is utilized to provide appropriate defocus correction information to an electronic filter, thereby providing an adaptive filtering arrangement.

Optical image defocus correction

A liquid crystal birefringent MTF filter is permanently positioned between lens and array of an image input scanner to reduce image modulation at frequencies where moire occurs, with a source of electric potential and a control switch for selectively applying the potential and switching the filter to or from a filtering state. In a variation of the first embodiment, a two-stage MTF filter is used. In a second embodiment, a tunable liquid crystal scattering MTF filter is combined with a full width sensor array.

Electronically variable MTF filter for image sensor arrays

A double Gauss reduction lens is optimized for projecting line images from an object plane onto a photosensor array. The six elements, four-component lens has a numeral focal length of 550 mm, a field of view of 17.degree. at the numeral 550 mm overall object to image conjugate length and a magnification of 0.1102. The lens is characterized by a high modulation transfer fequency, large depth of focus and low distortion.

Double gauss lens for a raster input scanner

A dual mode image input terminal having a linear scanning array with optical and illumination means supported on a carriage that, in a first scanning mode, reciprocates from a start-of-scan position to an end-of-scan position to scan a document opposite thereto on a transparent platen, and, in a second scanning mode, assumes a predetermined fixed scan position adjacent one side of the platen, with a Constant Velocity Transport (CVT) type document transport for moving the document past the fixed scan position with the document in preset spaced relation above and out of contact with the platen to avoid wear on the platen and allow room for document assisting devices ancillary to the CVT, and with the inside surface of the platen at the fixed scan position only being thicker than the remainder of the platen to raise the image focus point of the scanning array from the surface of the platen to the level of the document transported past the fixed scan position by the CVT.

Compensating platen for dual mode image input terminals

A high speed parallel process raster input scanner employing time delay in integration (TDI) arrays for scanning plural lines of an original document. The lines of image signals output by the arrays are processed simultaneously, such processing including a two dimensional digital processor for processing text and pictorial image signals which are then input to a detector for selecting one or the other of the text and pictorial image signals for output from the scanner.

Raster input scanner

A high density charge coupled device imaging array 28 with a bilinear array 30, 32 of photosites on a single integrated circuit chip is utilized in an image scanning configuration. Offset photosites 30a, 32a in two rows are coupled via transfer gates 36 to storage register 38 and then to shift register 44, and via transfer gates 34 to shift register 42. The output of these two shift registers 42, 44 are multiplexed to generate a single output pulse train representative of the information scanned.

Adjacent bilinear photosite imager

An ink jet printer having improved droplet sensing apparatus for calibrating the printer. The improved apparatus defines a number of sensing sites each having first and second light sources for directing light signals through a sensing zone and a single fiber optic light pipe leading away from the sensing zone to circuitry for detecting the presence of ink droplets in that sensing zone. The preferred apparatus includes two light emitting diodes, each of which generate visible light signals of different wavelengths. These two light signals are received by an output light pipe and travel together along the right pipe to means for detecting the intensity of the two signals and determining droplet positioning in the sensing zone as a function of the two intensities. One apparatus for differentiating between the two light intensities comprises first and second photo detectors which respond to the wavelength light generated by the two light sources. The output from these two detectors are then routed to a difference amplifier which gives an indication of droplet position as a function of time. A second way of sensing the intensities is to time multiplex the sources so that only one source illuminates the droplet at a given time. These intensities are then stored in a sample and hold circuit and compared with a difference amplifier in a manner identical to the multiple wavelength sensing embodiment.

Ink jet droplet sensing method and apparatus

The invention relates to an optical scanning system which utilizes a tilted lens array to image scan line segments onto an area array of detector units. Each line segment is imaged onto a multiple time integration segment which enhances effective exposure by integration of multiple scans for each line segment.

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Penfield, NY, United States of America

Ned J Seachman