Hewlett-packard Development Company, L.p.

Hewlett-packard Company

Craig T Johnson

Kenneth Kay Smith

Edward Anthony Hill

Patrick J Chase

Dejan Depalov

Baris Efe

Jerry Wagner

Di-Yuan Tzeng

Mark Edward Shaw

Ryan M Smith

Dennis J Schissler

George Henry Kerby

Stephen B Witte

Stuart Allman

Gary W Gragg

Joseph Scott McCoy

Lixia Li

Jeffrey A Sunamoto

Myungsae Son

Jain Chirag

Goudar Chanaveeragouda

Carolyn L Harris

William D Amidei

Richard M Dartez

An example scanner device includes a sealed enclosure including a scan window to allow light to enter the sealed enclosure, and an optical assembly including a light source and an image sensor. The light source is to emit light through the scan window onto a medium to be scanned. The image sensor is to capture light reflected by the medium through the scan window. The optical assembly is rotatably positioned within the sealed enclosure. An actuator is disposed within the sealed enclosure to rotate the optical assembly to aim the optical assembly at different locations on the scan window.

Rotatable scanner image sensors within sealed enclosures

Examples herein involve retrieving a color transformation from a highlighter color transform, and processing an image using the color transformation to enhance highlighter colors in the image, the image scanned by a scanner using strobed illumination.

Enhance highlighter color in scanned images

A scanner is disclosed. The scanner has a background pattern that is captured as part of the scanned image. The scanner may be a flatbed scanner, a sheet-feed scanner, or a flatbed scanner using an automatic document feeder (ADF).

Scanner with a background

A scanner is disclosed. The scanner has three lights with three different colors. The scanner uses only two of the three lights when capturing each scan line. The scanner does this by alternating the use of two of the three colors every other scan line.

Capturing a scan line with two colors

A scanner is disclosed. The scanner detects when the to surface of the ADF scan glass is contaminated.

Scanner that detects debris

An adaptive digital ramp current control system comprises a digital current ramp controller configured to digitally ramp a current level supplied to at least one light emitting diode (LED) according to a predetermined ramp profile, the ramp profile comprising at least one intermediate current level step between a minimum current level and a maximum current level.

System and method for adaptive digital ramp current control

In one embodiment, a scanning device includes a light source configured to selectively illuminate an area of interest and a light sensitive receiver configured to receive light from the light source and generate signals based on the received light. Control logic is configured to power the light source at a power level, generating mid-tone-scan signals at the light sensitive receiver. Calibration logic is configured to determine a calibration factor for a selected pixel based data including the mid-tone-scan signals.

Scanning device calibration system and method

A circuit connected to a linear array of photosensors generates image data representative of information printed on a document and adjusts the gains applied to the outputs of selected ones of the photosensors to eliminate streaks in the image data otherwise due to the selected photosensors imaging debris on an optical reference surface. The circuit determines which photosensors have low output values during a factory scan of a clean white reference surface. During a subsequent user environment calibration scan, low output values are adjusted to the average of their neighbors, but only for locations not identified as having low outputs during the factory scan. The circuit additionally performs a PRNU compensation and further adjusts the gains applied to each of the outputs of the photosensors so that all of their output values have a substantially uniform value.

Correction for debris and low output photosensors in scroll fed scanner using stored initial calibration data

A scanner includes a photodetector, and encoder and an exposure control. For each line of pixels detected by the photodetector, the exposure control starts the exposure time and then stops the exposure time after a specified amount of relative motion has been detected. Thus, variations in the amount of relative motion cause inversely proportional variations in the exposure time to ensure that exposure time for each line of pixels corresponds to the same displacement. The exposure control can compensate for unavoidable position and velocity errors encountered in a dc motor drive and thereby allows a dc motor drive to be used in low cost commercial scanning products.

Optical scanner including exposure control

A lamp control scheme for rapid warmup of a cold cathode fluorescent lamp, to minimize the warmup time while maintaining long lamp service light. The lamp is over-driven with high current for up to a predetermined time limit to accelerate mercury vaporization. The drive current is then reduced to a normal level. The scanner light output is monitored by a sensor circuit, and the system waits until the light output exceeds a minimum output and the light profile is sufficiently stable. The scanner is then calibrated to a white reference, and the closed loop control of the signal level is activated. The scan or copy process is now performed, and the light level control is deactivated as needed. Thereafter, between uses the lower lamp current is 40% of normal level to keep the lamp warm while extending the life of the product. If the product has not been used in a long time, the lamp is turned off.

Lamp control scheme for rapid warmup of fluorescent lamp in office

Each two-dimensional alignment mark on a printing medium is found by using information about the whole mark area, or with respect to each of two different directions relative to the medium by using a distinctive two-dimensional pattern or characteristic of the mark; or by finding the mark centroid, or by scanning the mark region to obtain a two-dimensional representation for analysis--and preferably by combinations of these procedures. An image is then aligned and printed by reference to the mark so located. A previous image may also be preprinted in known relation with the mark, so that the new image is aligned with the preprinted one--sometimes on the same piece of medium. Preferably information used includes the mark's intended size, shape, areal disposition and other properties; and a two-dimensional search template is defined which matches the mark in at least one of these. A template position is then found that essentially maximizes areal intersection with the mark; this position is then treated as the mark position, for printing the new image. The invention preferably determines a position of the template along each of two directions in alternation--maximizing the areal intersection with respect to shifting along each direction, iteratively--until no significant increase is obtained.

Growing community of inventors

San Diego, CA, United States of America

Craig T Johnson