Automatic hand-supportable laser bar code symbol scanner and method of reading bar code symbols using the same

• US 5,260,553 A
• Filed: 09/17/1990
• Issued: 11/09/1993
• 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: Wilz, David M. Sr., Rockstein, George B., Knowles, Carl H., Bubnoski, David P.
• Primary Examiner(s): Weinhardt, Robert A.
• Application Number:
  US07/583,421
• Time in Patent Office: 1,149 Days
• Field of Search: 235/462, 235/472, 235/455, 235/454, 235/470, 235/383
• US Class Current: 235/462.01
• 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 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

An automatic bar code symbol reading system comprising components for carrying out object detection, scanning, photoreceiving, A/D conversion, bar code presence detection, symbol decoding, data format conversion, data storage and data transmission functions. In general, the bar code symbol reading device includes a control system having a plurality of control centers that control the operation of the system components in accordance with preselected system control operations. Each of the control centers are responsive to control activation signals generated by certain of the system components upon the occurrence of predefined conditions. Certain of the control centers are capable overriding other control centers to provide diverse control capabilities which facilitate execution of intelligent operations and power conservation, during bar code symbol reading.

Claims

1. An automatic bar code symbol system having a selectable mode of operation in which a bar code symbol can be selectively read one or more times, said system comprising:

a hand-supportable housing having a light transmission aperture through which visible light can exit from and enter into said hand-supportable housing;

laser beam producing means, disposed in said hand-supportable housing, for producing a visible laser beam within said hand-supportable housing;

laser beam scanning means, disposed in said hand-supportable housing, for repeatedly scanning said visible laser beam across a scan field defined external to said hand-supportable housing and across a bar code symbol on an object located in at least a portion of said scan field;

laser light detecting means, disposed in said hand-supportable housing, for detecting the intensity of visible laser light reflected off said bar code symbol and passing through said light transmission aperture as said visible laser light reflected off said bar code symbol and passing through said light transmission aperture as said visible laser beam is repeatedly scanned across said bar code symbol present in said scan field, and for automatically producing scan data indicative of said detected intensity;

scan data processing means for processing produced scan data in order to detect and decode said bar code symbol when said bar code symbol is present in said scan field and automatically produce symbol character data in a form representative of said decoded bar code symbol and suitable for transmission to a symbol character data storage means,

said scan data processing means also including means for automatically processing produced scan data in order to determine that said decoded bar code symbol has become absent from said scan field, prior to said scan data processing means automatically processing produced scan data so as to detect and decode said decoded bar code symbol once again when said decoded bar code symbol is once again present in said scan field, and thereafter produce once again symbol character data in a form representative of said decoded bar code symbol and suitable for transmission to said symbol character data storage means;

control means for automatically controlling the operation of said laser beam producing means and said scan data processing means so that said bar code symbol is detected and decoded as said visible laser beam is repeatedly scanned across said bar code symbol present in said scan field, and after said scan data processing means detects the absence of said decoded bar code symbol from said scan field, said scan data in order to detect and decode said decoded bar code symbol once again when said decoded bar code symbol is once again present in said scan field, and thereafter automatically produces once again said symbol character representative of said decoded bar code symbol.

2. The system of claim 1, wherein said laser beam producing means comprises a laser diode.

3. The system of claim 1, wherein said bar code symbol has first and second envelope borders, and wherein said scan data processing means detects the presence of said bar code symbol in said scan field by processing produced scan data so as to detect the first and second envelope borders of said bar code symbol.

4. The system of claim 1, wherein said hand-supportable housing comprises a head portion and a handle portion, and wherein said laser beam producing means, said laser beam scanning means, and said laser detecting means are disposed in said head portion.

5. The system of claim 1, wherein said scan data processing means and said control means are disposed within said hand-supportable housing.

6. The system of claim 5, which further comprises a data output port for transmitting said symbol character data to said symbol character data storage means disposed external to said hand-supportable housing.

7. The system of claim 6, which further comprises a flexible connector cable physically associated with said data output port, for transmitting said bar code symbol data to said symbol character data storage means.

8. A method of selectively reading a bar code symbol one or more times using an automatic hand-supportable unit, comprising the sequence of steps:

(a) manually supporting said automatic hand-supportable unit adjacent an object bearing a bar code symbol so that said object is located within at least a portion of a scan field defined external to said automatic hand-supportable unit, and said automatic hand-supportable unit is disposed in a substantially non-contacting relationship with said object;

(b) producing a visible laser beam from a laser beam producing source disposed in said automatic hand-supportable unit, in repeatedly scanning said visible laser beam through a light transmission aperture in said automatic hand-supportable unit and across said bar code symbol while said bar code symbol is present in said scan field;

(c) automatically detecting at said automatic hand-supportable unit, the intensity of visible laser light reflected off said bar code symbol, and automatically producing scan data indicative of said detected intensity of visible laser light reflected off said bar code symbol;

(d) automatically processing scan data produced in step (c) in order to detect and decode said bar code symbol present in said scan field, and upon detecting and decoding said bar code symbol, automatically producing symbol character data in a form representative of said decoded bar code symbol and suitable for transmission to a symbol character data storage means operatively associated with said hand-supportable unit;

(e) moving said automatic hand-supportable unit relative to said object so as to cause said decoded bar code symbol to be absent from said scan field;

(f) producing said visible laser beam from said laser beam producing source, and repeatedly scanning said visible laser beam through said light transmission aperture and across said object while said bar code symbol is absent from said scan field;

(g) automatically detecting at said automatic hand-supportable unit, the intensity of visible laser light reflected off said object, and automatically producing scan data indicative of said detected intensity of visible laser light reflected off said object;

(h) automatically processing scan data produced in step (g) in order to detect the absence of said bar code symbol from said scan field;

(i) moving said automatic hand-supportable unit relative to said object so as to cause said decoded bar code symbol to be present once again in said scan field;

(j) projecting said visible laser beam from said laser beam producing source, and repeatedly scanning said visible laser beam through said light transmission aperture and across said bar code symbol present once again in said scan field;

(k) automatically detecting at said automatic hand-supportable unit, the intensity of visible laser light reflected off said decoded bar code symbol, and automatically producing scan data indicative of said detected intensity of visible laser light of the decoded bar code symbol;

(1) automatically processing scan data produced in step (k) in order to detect and decode once again said decoded bar code symbol, and upon detecting and decoding said decoded bar code symbol, automatically producing once again symbol character data in a form representative of said decoded bar code symbol and suitable for transmission to said symbol character data storage means.

9. The method of claim 8, where in steps (d), (h) and (l), said scan data is processed by a scan data processor disposed in said automatic hand-supportable unit.

10. The method of claim 8, where in steps (b), (f) and (j), said visible laser beam is produced by a laser diode disposed in said automatic hand-supportable unit.

11. The method of claim 8, wherein said bar code symbol has first and second envelope borders, and where in steps (d) and (h) the presence of said bar code symbol in said scan field is detected by processing produced scan data so as to detect the first and second envelope borders of said bar code symbol.

12. The method of claim 8, wherein said automatic hand-supportable unit comprises a housing having a head portion and a handle portion.