System and method for determining light source current

A system and method are provided for determining a light output of a light emitting diode (LED) in a scanner. The system includes a processor circuit to execute current control logic to obtain an optimum light output from the LED. The current control logic repeatedly applies increasing or decreasing...

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Bibliographic Details
Main Authors CAPPS VIRGINIA K, BOHAN DAVID G, KEITHLEY DOUGLAS G, JENSEN NANETTE C
Format Patent
LanguageEnglish
Published 11.12.2007
Subjects
COLORIMETRY
ELECTRIC COMMUNICATION TECHNIQUE
ELECTRICITY
MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT,POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRA-RED,VISIBLE OR ULTRA-VIOLET LIGHT
MEASURING
MEASURING ELECTRIC VARIABLES
MEASURING MAGNETIC VARIABLES
PHYSICS
PICTORIAL COMMUNICATION, e.g. TELEVISION
RADIATION PYROMETRY
TESTING
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Summary:A system and method are provided for determining a light output of a light emitting diode (LED) in a scanner. The system includes a processor circuit to execute current control logic to obtain an optimum light output from the LED. The current control logic repeatedly applies increasing or decreasing currents to the LED until a saturation point is identified. This may be accomplished, for example, by comparing two measures of the light output of the LED for two different currents applied to the LED. When a difference equaling a predetermined threshold between the two measures is detected, then the saturation point is identified.
Bibliography:Application Number: US20010855208