Patent ID: 6761317
Filing Date: 2004-07-13
Classification: G06K

Abstract:
A system for reading code symbols comprising:(A) a plurality of code symbol reading devices, each said code symbol reading device including: a mechanism for automatically scanning a code symbol on an object, a scan data production mechanism for producing symbol character data in a form representative of said scanned code symbol, a data packet synthesizing mechanism for synthesizing a data packet having a data field containing a code for identifying the code symbol reading device synthesizing said data packet, a data packet number for identifying said data packet, and a sequence of digital data bits representative of the symbol character data, and a signal generation mechanism for generating an electromagnetic carrier signal modulated by the digital data bits representative of said data packet, and transmitting said modulated carrier signal into at least a predetermined data transmission range in free space, wherein the frequency of the carrier signal produced by each said code symbol reading device is substantially the same and equal to a preselected carrier frequency; and (B) a plurality of base units, each of respective base units being assigned to a corresponding one of said code symbol reading devices, and positionable within the predetermined transmitting range, each said base unit including: a receiver for receiving a modulated carrier signal transmitted from said any one of the code symbol reading devices, a demodulator for demodulating any one of the received modulated carrier signals so as to recover at least one data packet therefrom, a data processing mechanism for analyzing said recovered data packet to determine whether the received data packet was synthesized by the corresponding assigned code symbol reading device, and if so, then recovering said symbol character data therefrom, a data buffer said symbol character data recovered from the data packet synthesized by the corresponding assigned code symbol reading device, and an indication mechanism for producing, in response to the recovery and buffering of said symbol character data, a visual and/or audible acknowledgement signal perceptible to the user of said assigned code symbol reading device when said user is situated within the predetermined data transmission range, so as to inform the user of said code symbol reading device that said symbol character data produced thereby has been received and recovered at the corresponding assigned base unit, data interface circuitry for interfacing the data output port of a computer keyboard with the data input port of a computer system, and a data conversion mechanism for converting the data format of said symbol character data recovered at said base unit into a data format which is substantially identical to the data format of data produced from the output of the computer keyboard.