×

Portable code symbol reading device with one-way wireless data packet transmission link to base unit employing condition-dependent acoustical signalling for data packet reception acknowledgement

  • US 5,808,285 A
  • Filed: 08/17/1994
  • Issued: 09/15/1998
  • Est. Priority Date: 09/17/1990
  • Status: Expired due to Term
First Claim
Patent Images

1. A system for reading code symbols on objects, comprising:

  • (A) a code symbol reading device, including(1) reading means for reading code symbols on one or more objects, and for automatically producing, for each said code symbol read, symbol character data representative of said read code symbol,(2) data packet group synthesizing means for automatically synthesizing, in response to each code symbol read by said reading means, a stream of digital data bits representative of a group of data packets, wherein each said data packet in said group has a plurality of data fields containing(i) said symbol character data produced by said reading means, and(ii) packet group identifying data for uniquely identifying the group of data packets to which said data packet belongs,(3) carrier signal generating means for generating a carrier signal of electromagnetic nature having a modulatable parameter,(4) signal modulation means for modulating said modulatable parameter of said carrier signal in accordance with each said digital data stream produced by said data packet group synthesizing means, and(5) carrier signal transmission means for transmitting said modulated carrier signal over a predetermined data transmission range in free space; and

    (B) a base unit positionable within the predetermined data transmission range of said code symbol reading device, and including(1) carrier signal receiving means for receiving said modulated carrier signal transmitted from said code symbol reading device,(2) signal demodulating means for demodulating said received modulated carrier signal,(3) data packet recovery means for recovering from said demodulated carrier signal, at least one data packet from said groups of data packets produced by said data packet group synthesizing means,(4) data packet analyzing means for analyzing the packet group identifying data contained in each recovered data packet so as to determine that the recovered data packet (a) belongs to a transmitted data packet group and (b) contains symbol character data which has not been (b)(1) extracted from a data packet in said transmitted data packet group and (b)(2) buffered for subsequent transmission to a host system,(5) data extracting means for extracting, symbol character data contained in a recovered data packet analyzed by said data packet analyzing means,(6) acknowledgment signal producing means for producing, when enabled, an acknowledgment signal perceptible by the user of said code symbol reading device when said user is situated within said predetermined data transmission range, and informing said user that the symbol character data produced by said code reading device has been successfully received and extracted,(7) data buffering means for buffering, when enabled, said extracted symbol character data for subsequent transmission to said host system, and(8) enabling means for automatically enabling said acknowledgment signal producing means to produce said perceptible acknowledgment signal and said data buffering means to buffer said extracted symbol character data only when said data packet analyzing means has determined that said recovered data packet being analyzed (i) belongs to a transmitted data packet group, and (ii) contains symbol character data representative of a code symbol read by said reading means which has not been (a) extracted from a data packet in said transmitted data packet group and (b) buffered in said data buffering means for subsequent transmission to said host system,whereby said perceptible acknowledgment signal informs the user of said code symbol reading device that the symbol character data produced thereby has been successfully received and extracted at said base unit.

View all claims
  • 7 Assignments
Timeline View
Assignment View
    ×
    ×