Method and apparatus for encoding and decoding bar codes with primary and secondary information and method of using such bar codes

• US 6,991,164 B2
• Filed: 02/06/2003
• Issued: 01/31/2006
• Est. Priority Date: 01/03/1995
• Status: Expired due to Fees

• Current Assignee: Lemelson Medical, Education & Research Foundation LP
• Original Assignee: Lemelson Medical, Education & Research Foundation LP
• Inventors: Lemelson, Jerome H., Hiett, John H.
• Primary Examiner(s): Kim, Ahshik
• Application Number:
  US10/360,155
• Publication Number:
  US 20030121980A1
• Time in Patent Office: 1,090 Days
• Field of Search: 235/462.01, 235/462.02, 235/462.03, 235/462.04, 235/462.09, 235/456, 235/494, 235/462.1, 235/462.11, 235/462.24, 235/449
• US Class Current: 235/456
• CPC Class Codes: G06K 19/06037 multi-dimensional coding
• CPC Class Codes: G06K 19/06056 the marking comprising a further embedded marking, e.g. a 1D bar code with the black bars containing a smaller sized coding
• 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 7/1434 Barcodes with supplemental or add-on codes

Abstract

A bar code (10) has primary information (46, 48, 50, 51) encoded in one direction (e.g., horizontally) and secondary information (13, 21, 36) encoded in another direction (e.g., vertically) in single (11) or multiple tracks (35) in selected ones of the vertical bars (11) of a bar code (10). Using a non-linear, variable amplitude scanner, all of the bars are scanned in the one direction to obtain all of the primary information and all of those vertical bars having secondary information are scanned in the other direction to obtain all of the secondary information. The one direction which is perpendicular to the vertical bars (11), is determined by first rotating the scan path axis (86, 87) until both start (46) and end (48) code bars are read thereby placing the scan path entirely within the total bar code, and, then, further rotating the scan path (88, 89) to determine the direction of the minimum crossing width (Lsc 80) of the total bar code (10). Secondary information is scanned in planes orthogonal to the one direction after those vertical bars (11) having such information are first identified and selected. In a preferred embodiment, the decoded secondary information may be used to control selected station process operations for selected products in a continuous manufacturing assembly line.

Claims

1. A method for reading a bar code having primary and secondary information encoded therein, comprising:

(a) optically scanning spaced apart bars of a magnetic ink bar code on a substrate and decoding the primary information encoded in the spaces and bars of the bar code; and

(b) magnetically scanning one or more of the bars and decoding the secondary information encoded in magnetic codes recorded within the ink of the one or more bars scanned.

2. The method of claim 1 wherein optically scanning is performed in one direction and magnetically scanning is performed in another direction.

3. The method of claim 1 further comprising encoding the secondary information in one or more magnetically recorded code tracks running longitudinally along one or more of the bars.

4. The method of claim 1 wherein optically scanning is performed perpendicular to the bars and magnetically scanning is performed parallel to the bars.

5. The method of claim 1 wherein the primary information is encoded in spaced-apart bars of a generally rectangular bar code, and wherein optically scanning includes:

(a) locating a direction perpendicular to the bars;

(b) scanning the bars in the perpendicular direction; and

(c) interpreting the decoded primary information obtained.

6. The method of claim 5 wherein locating a direction perpendicular to the bars further comprises scanning the bars with a scan beam in a scan path in a plane of the area, which path is rotated about one or more axes sequentially as necessary until the path crosses the entire bar code in a minimum crossing distance.

7. The method of claim 5 wherein locating a direction perpendicular to the bars further comprises:

(a) scanning the bars with a scan beam in a scan path in a plane of the bars while the path is rotated about one axis until the path crosses a start or stop code of the bar code thereby identifying a crossing length of the bar code;

(b) shifting the axis of rotation to a point within the bar code substantially at the center of the crossing length of the bar code; and

(c) continuing to rotate the scan path until both a start and stop code of the bar code are crossed in a minimum crossing length.

8. The method of claim 5 wherein locating a direction perpendicular to the bars further comprises:

(a) scanning the bars with a scan beam in a scan path at an angle to a transverse axis common to all of the bars;

(b) positioning the scan beam path across an entire crossing length of the bar code; and

(c) minimizing the entire crossing length of the scan beam path across the bar code.

9. The method of claim 8 wherein positioning the scan beam path across an entire crossing length of the bar code further comprises:

(a) rotating the scan beam path about a first axis until at least a portion of the bar code is crossed by the path;

(b) measuring the length of the path portion crossing the bar code;

(c) substantially re-positioning the axis of rotation of the path at the center of the path portion crossing the bar code; and

(d) rotating the scan beam path about the re-positioned axis until the scan beam path crosses the entire bar code.

10. The method of claim 9 wherein positioning the scan beam path across an entire crossing length of the bar code further comprises sequentially rotating the scan beam path about a plurality of axes as necessary until the scan path is inside of the entire bar code in a minimum crossing distance.

11. The method of claim 8 wherein positioning the scan beam further comprises changing the angle at which the bars are scanned in a direction wherein the crossing length decreases.

12. The method of claim 8 wherein minimizing the entire crossing length further comprises:

(a) substantially centering a scan rotation axis of the scan path at a center of a last measured crossing length of the bar code;

(b) changing the angle at which the bars are scanned in a direction of decreasing crossing length; and

(c) repeating the centering and changing steps until the crossing length is a minimum length across the entire bar code.

13. The method of claim 5 wherein locating a direction perpendicular to the bars further comprises using an image processing system to find the perpendicular direction.

14. The method of claim 5 wherein locating a direction perpendicular to the bars further comprises using multiple beams that find the perpendicular direction when the multiple beams simultaneously cross a bar.

15. A method for reading a bar code having an area with primary and secondary information encoded therein, comprising:

(a) encoding the primary information with spaced apart bars of a generally rectangular bar code;

(b) optically scanning the area to decode the primary information;

(c) magnetically scanning the area to decode the secondary information; and

(d) interpreting the decoded primary information obtained;

(e) wherein optically scanning includes (1) scanning the bars with a scan beam in a scan path in a plane of the area, which path is rotated about one or more axes sequentially as necessary until the path crosses the entire bar code in a minimum crossing distance, thereby locating a direction perpendicular to the bars, and (2) scanning the bars in the perpendicular direction.

16. The method of claim 15 wherein optically scanning further includes:

(a) scanning the bars with a scan beam in a scan path in a plane of the bars while the path is rotated about one axis until the path crosses a start or stop code of the bar code, thereby identifying a crossing length of the bar code;

(b) shifting the axis of rotation to a point within the bar code substantially at the center of the crossing length of the bar code; and

(c) continuing to rotate the scan path until both a start and stop code of the bar code are crossed in a minimum crossing length.

17. A method for reading a bar code having an area with primary and secondary information encoded therein, comprising:

(a) encoding the primary information with spaced apart bars of a generally rectangular bar code;

(b) optically scanning the area to decode the primary information;

(c) magnetically scanning the area to decode the secondary information; and

(d) interpreting the decoded primary information obtained;

(e) wherein optically scanning includes;

(1) scanning the bars with a scan beam in a scan path at an angle to a transverse axis common to all of the bars;

(2) positioning the scan beam path across an entire crossing length of the bar code;

(3) minimizing the entire crossing length of the scan beam path across the bar code, thereby locating a direction perpendicular to the bars; and

(4) scanning the bars in the perpendicular direction.

18. The method of claim 17 wherein positioning the scan beam path across an entire crossing length of the bar code further comprises:

(a) rotating the scan beam path about a first axis until at least a portion of the bar code is crossed by the path;

(b) measuring the length of the path portion crossing the bar code;

(c) substantially re-positioning the axis of rotation of the path at the center of the path portion crossing the bar code; and

(d) rotating the scan beam path about the re-positioned axis until the scan beam path crosses the entire bar code.

19. The method of claim 18 wherein positioning the scan beam path across an entire crossing length of the bar code further comprises sequentially rotating the scan beam path about a plurality of axes as necessary until the scan path is inside of the entire bar code in a minimum crossing distance.

20. The method of claim 17 wherein positioning the scan beam further comprises changing the angle at which the bars are scanned in a direction wherein the crossing length decreases.

21. The method of claim 17 wherein minimizing the entire crossing length further comprises:

(a) substantially centering a scan rotation axis of the scan path at a center of a last measured crossing length of the bar code;

(b) changing the angle at which the bars are scanned in a direction of decreasing crossing length; and

(c) repeating the centering and changing steps until the crossing length is a minimum length across the entire bar code.