Hewlett-packard Company

Hewlett-packard Development Company, L.P.

Michael J Steinle

Steven L Webb

Dan S Johnson

Greg A Degi

David Douglas Bohn

Robert Gregory Gann

Dean C Buck

Brian L Hastings

Steven G Henry

Edward S Beeman

Hans D Neumann

Jerry L Bybee

Joseph A Eccher

C William Elder, Jr

Duane L Starner

Joe A Eccher

A lens receives light emitted from an illumination source along an orientation in which a center of the lens is aligned with a central axis of illumination that forms an acute angle of incidence relative to a to-be-imaged surface and the lens directs the light toward the to-be-imaged surface.

Illumination assembly

An image scanner uses optical targets within the scanner to characterize imperfections of a lens system and to partially compensate for the imperfections using digital image processing. In one sample embodiment, a series of two-dimensional optical targets are placed outside the document scanning area. Each individual target is suitable for obtaining an estimate of the point-spread function for a small segment of the scan line. Each point-spread function is then used to compute a convolution kernel for the corresponding segment of the scan line. Alternatively, each point-spread function may be used in an iterative solution for a modified image. In an alternative embodiment, a two-dimensional known random pattern is provided for a target. Cross-correlation of a portion of the known random pattern with the scanned image of the same portion of known random pattern provides an estimate of the point-spread function for the portion of the scan line corresponding to the portion of the known random pattern. Providing a series of targets or continuous random target over the width of the scan line, within the scanner, enables determination of the point-spread function as a function of position for an assembled lens, at the humidity and temperature appropriate for the scan. As a result, a smaller, lower cost lens can be used and some the lens aberrations can be removed from the final scanned image.

Optical image scanner with internal measurement of point-spread function and compensation for optical aberrations

A CCD assembly comprising: a semiconductor chip having a first face surface; an active light sensitive region located on the first face surface; an inactive region located on the first face surface next adjacent the active region; and a nonreflective coating applied over at least a portion of the inactive region.

Charge coupled device with nonreflective coating

A feedback control system has two sinusoidal quadrature position feedback signals generated by photosensitive detectors that sense light reflected from (or transmitted through) position encoding strips that have a reflectance (or transmissivity) that varies sinusoidally along the length of the strip. The system may have one position encoding strip, with two photosensors offset along the length of the strip to provide a ninety degree phase offset. Alternatively, the system may have two strips that are offset in phase by ninety degrees. An error signal is produced directly within the servo loop without requiring computation of ARC-SIN or ARC-COSINE. The error signal is continuous, and position error is not sensitive to photosensor gain.

Feedback control system using optical incremental position encoder with dual sinusoidal intensity patterns

An imaging device is disclosed wherein the imaging portion of the imaging device is integrated into an optical positioning system. The imaging device has a linear array of photodetector elements that are used to generate machine-readable image data representing an object being imaged. At least one two-dimensional photodetector segment comprising a two-dimensional array of photodetector elements is integrated into the linear array of photodetector elements. The two-dimensional photodetector segments serve the dual function of providing image data and positioning data.

Integral positioning and imaging device

A process for compensation for real time changes of magnification in an optics system for an image scanner. Targets having high-contrast edges, on both sides of an image to be scanned, are scanned along with the image. If magnification changes, the number of pixels between the targets may change. The pixels between the targets are filtered to generate a fixed number of pixels. Photosensor sensitivity compensation values may be separated into factory compensation values and scanner pre-scan compensation values. Factory compensation values are applied before filtering. Differences between factory compensation values and pre-scan compensation values are applied after filtering.

Image scanner with compensation for magnification changes

An optical system that folds a light path multiple times with all the folded paths being coplanar. The light is first polarized. Then, the polarized light is reflected multiple times through a quarter-wave plate, finally being phase shifted to the proper polarization state to enable transmission out of the system. One optical element transmits light that is at one planar polarity and reflects light at the orthogonal planar polarity. Another optical element transmits light that is at one circular polarity and reflects light at the orthogonal circular polarity.

Optics for reducing one dimension of a folded optical path

A method for dynamically determining and adjusting the color balance of the light strip along one edge of the scanned area and adjusting the gains of independently controlled red, green and blue channels of a CCD array. Alternatively, the gain of one color channel may be held constant and measured to determine the light intensity of the light source as the temperature of the light source varies. The power to the light is then changed to maintain the intensity of the light source within a predetermined range. The three color channels are then compared to a predetermined color balance. If the color balance is outside of a predetermined range, the other two color channels gains are varied in order to maintain the color balance between the three color channels.

Method and apparatus for dynamic white point adjustment

The optical photoelectric imaging apparatus adjusts automatically using closed-loop control before each scan to optimize scanning quality. Various optical components can be moved in order to align a scanned image of an object with the linear photosensor array. The device scans a target of known characteristics to determine what adjustment is needed.

Imaging device with beam steering capability

A scanning apparatus having a linear photosensor, an imaging assembly, and a scanning displacement assembly adapted for producing relatively constant rate linear displacement between an imaged object and the imaging assembly to cause scan line portions of the object to be sequentially imaged on the linear photosensor device and an image registration holding assembly associated with the scanning displacement device to cause an image from each different scan line portion on the object to be temporarily held in registration with the linear photosensor.

Color optical scanner with image registration holding assembly

A photosensor device which comprises a first photosensor array having a first predetermined number of pixels for generating a first data signal indicative of a first color component image of an object which is imaged thereon; a second photosensor array having a second predetermined number of pixels for generating a second data signal indicative of a second color component image of the object which is imaged thereon; and color registration error correction means operatively associated with the photosensor array for correcting color registration error due to a predetermined difference in image size between the first color component image and the second color component image.

Method and apparatus for correcting color registration error

An optical scanning device for generating a data signal representative of an object which is scanned comprising a light source for illuminating the object; an imaging assembly for projecting imaging light from the object onto an image plane; a plurality of linear photosensor arrays positioned at the image plane for generating light sensing signals indicative of the intensity of light in different spectral regions impinged thereon; a transparent plate positioned in adjacent overlying relationship with the photosensor arrays; a plurality of filter coatings disposed on different regions of the transparent plate in alignment the plurality of photosensor arrays for filteringly transmitting imaging light in the predetermined different spectral regions to the different photosensor arrays.

Color image sensing assembly with multiple linear sensors and aligned

An apparatus for assembling components of a color optical scanner subassembly which includes a first filter member, a second filter member and a photosensor unit. The apparatus includes an imaging means for impinging an imaging light beam from a line object onto the first and second filter assemblies for producing spatially separated color component images of the line object on the photosensor unit. The apparatus also includes a physical adjustment assembly for holding and selectively adjusting the relative position of the first filter member, the second filter member and the photosensor unit in response to data signals generated by the photosensor unit. This positioning accurately locates the filter members relative to the photosensor unit for optimizing performance of the color optical scanner.

Apparatus for assembling components of color optical scanners

An optical separator device for splitting a beam of incident polychromatic light into a plurality of spacially and spectrally separated component beams having parallel optical axes including a first composite for spectrally and spacially separating the incident beam into a first plurality of component beams and having a first plurality of parallel, spectrally selective, reflective layers including a layer adapted to reflect light in a first spectral range and a second spectral range; a second composite for further spectrally and spacially separating the first plurality of component beams into a second plurality of component beams and having a second plurality of parallel, spectrally selective, reflective layers including a layer adapted to reflect light in the spectral range and to transmit light in the second spectral range.

Beam splitter/combiner apparatus

A color imaging assembly for forming spatially separated, color component images of an object on a unitary image plane, comprising an imaging lens adapted for receiving a polychromatic imaging light beam from the object for imaging the object on the unitary image plane; a unitary multilayered beam splitter disposed obliquely in the path of the polychromatic, imaging light beam for splitting the polychromatic light beam into a plurality of parallel, spatially separated, color component beams having optical axes positioned perpendicular to the unitary image plane; and a path length compensator device disposed between the beam splitter and the unitary image plane for refractively compensating for differences in optical path lengths of the plurality of color component beams whereby each of the color component beams provides a focused color component image of the object on the unitary image plane is disclosed. A beam combiner assembly having a component beam path length compensator device is also disclosed.

Growing community of inventors

Fort Collins, CO, United States of America

Michael J Steinle