Bar code symbol reading system employing an extremely elongated laser scanning beam capable of reading poor and damaged quality bar code symbols with improved levels of performance

• US 8,376,233 B2
• Filed: 06/15/2011
• Issued: 02/19/2013
• Est. Priority Date: 06/15/2011
• Status: Active Grant

• Current Assignee: Metrologic Instruments Incorporated (Honeywell International Inc.)
• Original Assignee: Metrologic Instruments Incorporated (Honeywell International Inc.)
• Inventors: Giordano, Patrick Anthony, Amundsen, Thomas, Olson, Daniel James, Brady, Robert Hugh, Colavito, Stephen, Saber, Kevin, Haggerty, Thomas, Wilz, David M. Sr., Horn, Erik Van
• Primary Examiner(s): Le, Thien M
• Assistant Examiner(s): LY, TOAN C
• Application Number:
  US13/160,897
• Publication Number:
  US 20120318868A1
• Time in Patent Office: 615 Days
• Field of Search: 235/462.1, 235/462.25
• US Class Current: 235/462.25
• CPC Class Codes: G06K 7/10564 Light sources
• CPC Class Codes: G06K 7/146 the method including quality enhancement steps

Abstract

The system includes a housing having a light transmission window and produces an extremely-elongated laser beam having an elongation ratio (ER) that is defined as greater than 4.5 for any point within the working range of the laser scanning bar code symbol reading system. A laser scanning mechanism is provided for scanning the extremely-elongated laser beam out the light transmission window and across a scanning field defined external to the housing, in which a bar code symbol is present for scanning by the extremely-elongated laser scanning beam.

Claims

1. A laser scanning bar code symbol reading system for scanning and reading poor quality or damaged bar code symbols, said laser scanning bar code symbol reading system having a working range and comprising:

a housing having a light transmission window;

an extremely-elongated laser beam production module for producing an extremely-elongated laser beam haying (i) a direction of propagation extending along a z reference direction, (ii) a height dimension being indicated by the y reference direction, and (iii) a width dimension being indicated by the x reference direction, where x, y and z reference directions are orthogonal to each other;

wherein said extremely-elongated laser beam is characterized by an elongation ratio (ER) that is defined as Y/X>

4.5 for any point within said working range of said laser scanning bar code symbol reading system, extending along said z reference direction;

where (i) Y indicates the beam height of said extremely-elongated laser beam measured in said y reference direction, and X indicates the beam width of said extremely-elongated laser beam measured in the x reference direction, and (iii) beam height (Y) and said laser beam width (X) are measured at 1/e² intensity clip level,

wherein said elongation ratio (ER) is greater than 4.5 over the entire working range of said laser scanning bar code symbol reading system, along said z reference direction, and

wherein said elongation ratio (ER) has a maximum value greater than 9.0 at or near the waist portion of said extremely-elongated laser beam, occurring within the working distance of said laser scanning bar code symbol reading system, so as to help optimize the reading of bar code symbols when scanned by the waist portion of said extremely-elongated laser beam; and

a laser scanning mechanism for scanning said extremely-elongated laser beam out said light transmission window and across a scanning field defined external to said housing, in which a bar code symbol is present for scanning by said extremely-elongated laser scanning beam.

2. The laser scanning bar code symbol reading system of claim 1, wherein said bar code symbol is a code symbol selected from the group consisting of 1D bar code symbols, and 2D stacked bar code symbols.

3. The laser scanning bar code symbol reading system of claim 1, wherein said extremely-elongated laser beam production module comprises a laser drive circuit for generating and delivering laser drive current signals to a laser source to produce said extremely-elongated laser scanning beam.

4. The laser scanning bar code symbol reading system of claim 3, which further comprises:

light, collection optics for collecting light reflected/scattered from scanned object in the scanning field, and a photo-detector for detecting the intensity of collected light and generating an analog scan data signal corresponding to said detected light intensity during scanning operations;

an analog scan data signal processor/digitizer for processing the analog scan data signals and converting the processed analog scan data signals into digital scan data signals, which are then converted into digital words representative of the relative width of the bars and spaces in the scanned code symbol structure;

programmed decode processor for decode processing digitized data signals, and generating symbol character data representative of each bar code symbol scanned by said extremely-elongated laser scanning beam.

5. The laser scanning bar code symbol reading system of claim 4, which further

an input/output (I/O) communication interface module for interfacing with a host communication system and transmitting symbol character data thereto via wired or wireless communication links that are supported by the symbol reader and host system;

and

a system controller for generating the necessary control signals for controlling operations within said laser scanning bar code symbol reading system.

6. The laser scanning bar code symbol reading system of claim 4, wherein said housing comprises a hand-supportable housing.

7. The laser scanning bar code symbol reading system of claim 4, wherein said laser source comprises a visible laser diode (VLD).

8. A laser scanning system for scanning poor quality or damaged bar code symbols, said laser scanning system having a working range and comprising:

a housing having a light transmission window;

an extremely-elongated laser beam production module for producing an extremely-elongated laser beam having (i) a direction of propagation extending along a z reference direction, (ii) a height dimension being indicated by the y reference direction, and (iii) a width dimension being indicated by the x reference direction, where x, y and z reference directions are orthogonal to each other;

wherein said extremely-elongated laser beam is characterized by an elongation ratio (ER) that is defined as Y/X>

4.5 for any point within said working, range of said laser scanning bar code symbol reading system, extending along said z reference direction;

where (i) Y indicates the beam height of said extremely-elongated laser beam measured in said y reference direction, and X indicates the beam width of said extremely-elongated laser beam measured in the x reference direction, and (iii) said beam height (Y) and said laser beam width (X) are measured at 1/e² intensity clip level;

wherein said elongation ratio (ER) is greater than 4.5 over the entire working range of said laser scanning bar code symbol reading system, along said z reference direction, and

wherein said elongation ratio (ER) has a maximum value greater than 9.0 at or near the waist portion of said extremely-elongated laser beam, occurring within the working distance of said laser scanning bar code symbol reading system, so as to help optimize the reading of bar code symbols when scanned by the waist portion of said extremely-elongated laser beam; and

a laser scanning mechanism for scanning said extremely-elongated laser beam out said light transmission window and across a scanning field defined external to said housing, in which a bar code symbol is present for scanning by said extremely-elongated laser scanning beam.

9. The laser scanning system of claim 8, wherein said bar code symbol is a code symbol selected from the group consisting of 1D bar code symbols, and 2D stacked bar code symbols.

10. The laser scanning system of claim 8, wherein said extremely-elongated laser beam production module comprises a laser drive circuit for generating and delivering laser (diode) drive current signals to a laser source to produce said extremely-elongated laser scanning beam.

11. The laser scanning system of claim 10, wherein said laser source comprises a visible laser diode (VLD).

12. The laser scanning system of claim 8, which further comprises:

light collection optics for collecting light reflected/scattered from scanned object in the scanning field, and a photo-detector for detecting the intensity of collected light and generating an analog scan data signal corresponding to said detected light intensity during seaming operations;

an analog, scan data signal processor/digitizer for processing the analog scan data signals and converting, the processed analog scan data signals into digital scan data signals, which are then converted into digital words representative of the relative width of the bars and spaces in the scanned bar code symbol;

programmed decode processor for decode processing digitized data signals, and generating symbol character data representative of each bar code symbol scanned by said extremely-elongated laser scanning beam.

13. The laser scanning system of claim 8, wherein said housing comprises a hand-supportable housing.

14. A method of laser scanning a bar code symbol comprising the steps:

(a) producing from a hand-supportable housing, an extremely-elongated laser beam having (i) a direction of propagation extending along a z reference direction, (ii) a height dimension being indicated by the y reference direction, and (iii) a width dimension being indicated by the x reference direction, where x, y and z reference directions are orthogonal to each other;

wherein said extremely-elongated laser beam is characterized by an elongation ratio (ER) that is defined as Y/X>

4.5 for any point within said working range of said laser scanning bar code symbol reading system, extending along said z reference direction;

where (i) Y indicates the beam height of said extremely-elongated laser beam measured in said y reference direction, and X indicates the beam width of said extremely-elongated laser beam measured in the x reference direction, and (iii) said beam height (Y) and said laser beam width (X) are measured at 1/e² intensity clip level; and

(b) scanning said extremely-elongated laser beam across a scanning field defined external to said hand-supportable housing, in which a bar code symbol is present for scanning by said extremely-elongated laser scanning beam;

wherein said elongation ratio (ER) is greater than 4.5 over the entire working range of said laser scanning bar code symbol reading system, along said z reference direction, and

wherein said elongation ratio (ER) has a maximum value greater than 9.0 at or near the waist portion of said extremely-elongated laser beam, occurring within the working distance of said laser scanning bar code symbol reading system, so as to help optimize the reading of bar code symbols when scanned by the waist portion of said extremely-elongated laser beam.

15. The method of claim 14, which further comprises:

(c) collecting light reflected/scattered from scanned bar code symbol in said scanning field, and detecting the intensity of said collected light and generating an analog scan data signal corresponding to said detected light intensity during scanning operations;

(d) processing said analog scan data signals and converting the processed analog scan data signals into digital scan data signals, and then converted said digital scan data signals into digital words representative of the relative width of the bars and spaces in the scanned bar code symbol; and

(e) decode processing digitized scan data signals, and generating symbol character data representative of each bar code symbol scanned by said extremely-elongated laser scanning beam.

16. The method of claim 14, wherein said bar code symbol is a code symbol selected from the group consisting of 1D bar code symbols, and 2D stacked bar code symbols.