Calibrating system for a compact optical sensor

• Main Authors: HEILES TOD S, SARMAST SAM, GUDAITIS ALGRID M, ARQULLEVICH DAN
• Format: Patent
• Language: English
• Published: 10.01.2006
• Subjects: COLORIMETRY; CORRECTION OF TYPOGRAPHICAL ERRORS; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; LINING MACHINES; MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT,POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRA-RED,VISIBLE OR ULTRA-VIOLET LIGHT; MEASURING; PERFORMING OPERATIONS; PHYSICS; PICTORIAL COMMUNICATION, e.g. TELEVISION; PRINTING; RADIATION PYROMETRY; SELECTIVE PRINTING MECHANISMS; STAMPS; TESTING; TESTING STATIC OR DYNAMIC BALANCE OF MACHINES ORSTRUCTURES; TESTING STRUCTURES OR APPARATUS NOT OTHERWISE PROVIDED FOR; TRANSPORTING; TYPEWRITERS

A compact optical sensing system is used in hardcopy devices for scanning and/or printing images, for instance, using inkjet printing technology in desktop printing or in photographic printers appearing in grocery and variety stores. Several light emitting diodes ("LEDs") illuminate a sheet of print media, and one or more photodiodes receive light reflected from the sheet. The photodiode generates signals in response to the light received, and the hardcopy device uses these signals to adjust printing parameters for optimal print quality. Using a chip-on-board process, the bare silicon die for each component is wire bonded directly to a printed circuit board assembly, allowing at least four LEDs (blue, green, red and soft-orange) to be grouped closely together in a space smaller than that occupied by a factory-made, single-packaged LED. A calibrating system uses a white target covered for cleanliness by a windowed door which is opened/closed by a printhead carriage.