Hewlett-packard Development Company, L.P.

Hewlett-packard Company

Stephen B Witte

Damon W Broder

Brent W Richtsmeier

Mark A Flores

Todd R Medin

Glenn W Gaarder

Robert R Giles

Abdolreza Movaghar

Todd L Russell

Craig T Johnson

Steven Wayne Hendrix

Gary W Gragg

Jeffrey A Sunamoto

An optical scanner includes a CCD and a light monitor window ('LMW') and a black region adjacent the LMW. The LMW is imaged to provide feedback signals for Red, Green and Blue channels of the CCD. The black region is imaged to remove flare from the feedback signals. The flare-corrected feedback signals may be supplied to gain compensation controls.

Optical scanner providing compensation for non-uniform bulb illumination

An optical scanner system wherein the central region of the light source is selectively covered up by a mechanically actuated shutter during a transparency scanning mode. By occluding the central portion of the light source, problems with flare and degraded image quality are eliminated. The shutter is actuated to its two positions (normal reflective mode position, transparency mode position) by pins, protrusions, or the scanner walls in the scan module path. When the scan module is driven to the extremes of its travel the shutter is either driven open or closed. A bracket structure is provided to hold the transparent media and a covering light reflective tent, and can include the pin or pins that can protrude into the scanner module path and thus actuate the shutter only when the structure is mounted on to the scanner by the user. The bracket structure can include a lower member that rests directly on the platen glass to align filmstrips, slides, and other transparent media. The tent structure is hinged relative to the lower structure which allows it to be opened and closed to enable insertion of transparent media. When the tent structure is closed it acts as the reflective light path to allow light from the primary light source to be reflected up, over, and down through the transparent media, and into the optical light path leading to the optical sensor.

Light source shutter for scanning transparent media through overhead reflective light path

An optical scanner includes a CCD and a light monitor window (&ldquo;LMW&rdquo;) and a black region adjacent the LMW. The LMW is imaged to provide feedback signals for Red, Green and Blue channels of the CCD. The black region is imaged to remove flare from the feedback signals. The flare-corrected feedback signals may be supplied to gain compensation controls.

A scanner system and method are described, wherein two lenses are mounted on a slider positioned in the optical light path between two moving mirrors and the optical sensor. Each mirror is mounted on a moving carriage. The slider is bistable in two alignment positions, one for each lens. The slider is moved by the motion of one of the carriages. As the carriage moves toward the lens slider, a linkage causes the slider to move from the position it is currently in to the other position. This system allows the slider to be shuttled from one position to the other, thereby changing resolutions, using energy provided by the same motor that moves the mirrors.

Multiple resolution selectable lens scanning system and method

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

A backlash control system for a printer medium drive system having a motor-driven gear train for driving medium-engaging rollers. Pinion gears mounted on the motor drive shaft mesh with a main gear and a tension gear, mounted in turn on a main drive and a tension roller. An anti-backlash spring device includes pinch fingers which exert a pinch force on the main and tension gears. The pinch fingers are mounted at ends of a horizontal spring beam secured at an intermediate pivot point. As the motor turns to drive the print medium forward, the pinch force results in bowing of the horizontal beam, tending to exert a restoring force on the main and tension gears. As the motor direction is reversed and stopped, the restoring force results in the main and tension gears being pulled backwards to keep the gear teeth meshed tightly to the pinion gear teeth. The pinch fingers also exert a thrust load axially against the main drive and tension gears.

Printer motor drive with backlash control system

A pinch wheel is mounted to be spring-loaded against an exit drive roller in close proximity to a print zone, with the pinch wheel formed by a dual starwheel having two spaced-apart sets of teeth for contacting a newly-printed media surface without puncturing or damaging the media.

Double star wheel for post-printing media control in inkjet printing

An ink-jet printer having improved print quality and full color printing capability on plain paper media. To accommodate placement of both input and output media trays on the same side of the printer housing for operator convenience, a paper path with a direction reversal is employed. A low cost radiant print heater with a reflector cavity heats the medium at the print area to increase the ink carrier evaporation rate. The printer provides improved medium control at the print area through an arrangement of small diameter drive and tension shafts and shortened handoff distance between the rollers. The heater is disposed between the drive and tension rollers. To minimize the handoff distance, portions of the drive rollers extend into the reflector cavity. The resulting media advancement mechanism has low inertia, with improved media positioning accuracy.

Growing community of inventors

Poway, CA, United States of America

Stephen B Witte