04970379 is referenced by 74 patents and cites 7 patents.

In an exemplary wand type bar code scanner the scanner circuit includes a first control loop for reducing the LED driving current as the D.C. voltage level supplied to the digitizer tends to exceed a selected D.C. reference value; a second control loop becomes active when the LED is shut off by the first control loop, e.g. in the presence of sunlight. The second control loop controls the gain of the scanner amplifier so that the D.C. reference level at the input to the digitizer circuit is maintained as the scanner scans bar codes in the presence of sunlight but with the LED de-energized.

Title
Bar code scanner system and scanner circuitry therefor
Application Number
44820
Publication Number
4970379
Application Date
October 12, 1988
Publication Date
November 13, 1990
Inventor
Eric J Danstrom
Cedar Rapids
IA, US
Agent
Neuman Williams Anderson & Olson
Assignee
Norand Corporation
IA, US
IPC
G06K 7/14
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