Reading bar code symbols using readers having one-way RF signal transmission links with base stations

• US 6,761,317 B1
• Filed: 08/05/2002
• Issued: 07/13/2004
• Est. Priority Date: 09/17/1991
• Status: Expired due to Fees

• Current Assignee: Metrologic Instruments Incorporated (Honeywell International Inc.)
• Original Assignee: Metrologic Instruments Incorporated (Honeywell International Inc.)
• Inventors: Wilz, David M. Sr., Germaine, Gennady, Colavito, Stephen J., Rockstein, George B., Knowles, Carl H.
• Primary Examiner(s): Le, Thien M.
• Assistant Examiner(s): TRAIL, ALLYSON NEEL
• Application Number:
  US10/213,383
• Time in Patent Office: 708 Days
• Field of Search: 235/472.01, 235/462.15, 235/487, 235/454, 235/380, 235/462.45, 235/383, 235/375, 235/381
• US Class Current: 235/472.01
• 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 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 7/10594 Beam path
• CPC Class Codes: G06K 7/10603 Basic scanning using moving elements
• 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 7/10851 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 7/10881 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 7/14 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;

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.

2. The system of claim 1, wherein each said code symbol reading device comprises a laser diode for producing a beam that is repeatedly scanned across said code symbol situated in a scan field defined external to the code symbol reading device.

3. The system of claim 2, wherein the code symbol reading device further includes an object detector providing an object detection field which spatially encompasses at least a portion of the scan field, thereby improving aiming efficiency of the code symbol reading device.

4. The system of claim 3, wherein the object detector includes an adjustable range selection mechanism for selecting from among a short range mode of object detection and a long-range mode of object detection, and wherein the long range mode encompasses a greater spatial volume than the short range mode.

5. The system of claim 4 wherein the long-and short-range modes are manually selected by a user by way of a manual activation of a switch on the code symbol reading device.

6. The system of claim 4, wherein the base unit further includes a support frame for removably supporting the code symbol reading device, and wherein the long-range mode of object detection is automatically selected when the code symbol reading device is in the support frame.

7. The system of claim 6, wherein the short-range mode of object detection is automatically selected when the code symbol reading device is removed from the support frame.

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

9. The system of claim 8, wherein the acknowledgement signal further comprises a light signal visible to the user of the code symbol reading device when the user is situated within the predetermined data transmission range.

10. The system of claim 8, wherein the acoustical signal produced by each said base unit has at least one uniquely identifiable pitch characteristic corresponding to said assigned code symbol reading device.

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

a tuned circuit resonant at the preselected carrier frequency,

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

a demodulator, operably associated with the receiver circuit, for demodulating the received modulated carrier signal to retrieve one or more data packets.

12. The system of claim 1, wherein each base unit further comprises a data processing unit selected from the group consisting of a 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.

13. The system of claim 1, wherein the data processing mechanism of the base unit is equipped to distinguish data packets associated with consecutively different bar code symbols read by a particular code symbol reading device, without the base unit transmitting an electromagnetically based acknowledgement signal after receiving each data packet.

14. The system of claim 1, wherein the base unit further includes a support frame for supporting the code symbol reading device in a selected mounting position so as to permit a gripping of the code symbol reading device prior to removing the code symbol reading device from the support frame.