System for reading bar code symbols using portable bar code symbol readers having one-way RF signal transmission links with base stations

• US 6,015,091 A
• Filed: 07/09/1997
• Issued: 01/18/2000
• Est. Priority Date: 09/17/1990
• Status: Expired due to Fees

• Current Assignee: Metrologic Instruments Incorporated (Honeywell International Inc.)
• Original Assignee: Metrologic Instruments Incorporated (Honeywell International Inc.)
• Inventors: German, Gene, Colavito, Stephen J., Rockstein, George B., Knowles, Carl Harry, Wilz, David M.
• Primary Examiner(s): Le, Thien Minh
• Application Number:
  US08/890,576
• Time in Patent Office: 923 Days
• Field of Search: 235/462, 235/472, 235/469, 235/470, 235/463, 235/494, 375/1
• US Class Current: 235/472.01
• CPC Class Codes: G02B 26/106 having diffraction gratings as scanning elements, e.g. holographic scanners holographic optical elements G02B5/32, holography G03H
• CPC Class Codes: G06K 17/0022 arrangements or provisious for transferring data to distant stations, e.g. from a sensing device "transfer between computer elements G06F13/00 "; data-transmission H04L
• CPC Class Codes: G06K 2007/10534 Scanner to be worn on a finger or on a wrist
• CPC Class Codes: G06K 2207/1012 Special detection of object
• CPC Class Codes: G06K 2207/1016 Motor control or optical moving unit control
• CPC Class Codes: G06K 2207/1017 Programmable
• CPC Class Codes: G06K 2207/1018 Source control
• CPC Class Codes: G06K 7/10 by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
• CPC Class Codes: G06K 7/10564 Light sources
• CPC Class Codes: G06K 7/10584 Source control
• CPC Class Codes: G06K 7/10594 Beam path
• CPC Class Codes: G06K 7/10603 Basic scanning using moving elements
• CPC Class Codes: G06K 7/10663 using hologram
• CPC Class Codes: G06K 7/10673 Parallel lines
• CPC Class Codes: G06K 7/10693 for omnidirectional scanning
• CPC Class Codes: G06K 7/10702 Particularities of propagating elements, e.g. lenses, mirrors G06K7/10831 takes precedence
• CPC Class Codes: G06K 7/10792 Special measures in relation to the object to be scanned
• CPC Class Codes: G06K 7/10801 Multidistance reading
• CPC Class Codes: G06K 7/10811 Focalisation
• CPC Class Codes: G06K 7/10851 Circuits for pulse shaping, amplifying, eliminating noise signals, checking the function of the sensing device basic electronic circuitry H03
• CPC Class Codes: G06K 7/10861 : sensing of data fields affixed to objects or articles, e.g. coded labels postal sorting B07C3/14, conveying articles B65G47/48
• CPC Class Codes: G06K 7/10871 : randomly oriented data-fields, code-marks therefore, e.g. concentric circles-code
• CPC Class Codes: G06K 7/10881 : constructional details of hand-held scanners
• CPC Class Codes: G06K 7/10891 : the scanner to be worn on a finger or on a wrist
• CPC Class Codes: G06K 7/109 : adaptations to make the hand-held scanner useable as a fixed scanner
• CPC Class Codes: G06K 7/14 : using light without selection of wavelength, e.g. sensing reflected white light G06K7/10831 - G06K7/1097 take precedence
• CPC Class Codes: G06K 7/1443 : locating of the code in an image

Abstract

A code symbol reading device includes a portable housing that contains a light source. Light from the light source is projected into a scan field external to the housing and onto a code symbol on an object located within the scan field. The light reflected off the code symbol is detected within the housing to produce scan data that is indicative of the detected light intensity. The scan data is processed to detect and decode the code symbol and to produce symbol character data that are representative of the decoded code symbol. A data packet utilizing the symbol character data is synthesized and modulated onto a carrier signal that is transmitted to a base unit where the carrier signal is demodulated and the data packet recovered. The received data packet is analyzed to recover the symbol character data, and an acknowledgment signal is produced to acknowledge the receipt of the symbol character data at the base unit.

Claims

1. A system for reading code symbols comprising:

(A) a plurality of code symbol reading devices, each said code symbol reading device including

means for automatically scanning a code symbol on an object,

means for automatically producing symbol character data in a form representative of said scanned code symbol,

mean for synthesizing a group of data packets, each having a plurality of data fields containing codes for identifying the code symbol reading device synthesizing said data packet in said group thereof, a data packet number for identifying each said data packet, a data packet group number for identifying the group to which each said data packet belongs, and a sequence of digital data bits representative of said symbol character data, and

means for generating a carrier signal of electromagnetic nature, having a frequency modulated by the digital data bits representative of said group of data packets, and transmitting said modulated carrier signal over 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 frequency value; and

(B) a plurality of base units, each said base unit being assigned to one said code symbol reading device, and positionable within the predetermined transmitting range thereof, and including

means for receiving a modulated carrier signal transmitted from said any one of said code symbol reading devices,

means for demodulating any one of the received modulated carrier signals so as to recover at least one data packet therefrom,

means for analyzing said recovered data packet to determine whether the received data packet was synthesized by its assigned code symbol reading device, and if so, then recovering said symbol character data therefrom,

means for buffering said symbol character data recovered from the data packet synthesized by said preassigned code symbol reading device, and

means for automatically producing, in response to the recovery and buffering of said symbol character data, an acknowledgement signal perceptible to the user of said assigned code symbol reading device when said user is situated within said 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 said assigned base unit.

2. The system of claim 1, wherein each said code symbol reading device comprises a laser diode for producing a visible laser that is repeatedly scanned across said code symbol.

3. The system of claim 1, wherein said acknowledgement signal comprises an acoustical signal audible to the user of said code symbol reading device when said user is situated within said predetermined data transmission range.

4. The system of claim 3, wherein said acknowledgement signal further comprises a light signal visible to the user of said code symbol reading device when said user is situated within said predetermined data transmission range.

5. The system of claim 3, wherein said acoustical signal produced by each said base unit has at least one uniquely identifiable pitch characteristic assigned to said preassigned code symbol reading device.

6. The system of claim 1, wherein each said base unit comprises

a circuit tuned to said preselected frequency, and

a receiving element operably associated with said circuit, for receiving the modulated carrier signal transmitted from any one or more of said code symbol reading devices.

7. The system of claim 1, wherein each said base unit further comprises

data interface circuitry for interfacing the data output port of a computer keyboard with the data input port of a computer system, and

data conversion means 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 said computer keyboard.

8. The system of claim 1, wherein each said base unit further comprises a data processing unit selected from the group consisting of slot-type bar code symbol reader, a projection-type bar code symbol reader, a cash register, a host computer system, and a portable collection device.