Method of decoding a two-dimensional code symbol mark

• US 5,343,031 A
• Filed: 12/31/1992
• Issued: 08/30/1994
• Est. Priority Date: 04/06/1992
• Status: Expired due to Term

• Current Assignee: Teiryo Sangyo Company Limited
• Original Assignee: Teiryo Sangyo Company Limited
• Inventors: Yoshida, Hirokazu
• Primary Examiner(s): PITTS, HAROLD I
• Application Number:
  US07/999,130
• Time in Patent Office: 607 Days
• Field of Search: 235/494, 235/454, 235/456
• US Class Current: 235/494
• CPC Class Codes: G06K 19/06037 multi-dimensional coding
• CPC Class Codes: G06K 2019/06262 with target- or other orientation-indicating feature
• 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 7/1417 2D bar codes

Abstract

A method for decoding and processing at high speed by reading two-dimensional code symbol marks by a code reader in a small memory capacity. The X-axis side indication line 4 or Y-axis side indication line 5 in an information area 8 recording the code symbol mark 2 is read by the code reader 3, and division marks 7 recorded on the X-axis side indication line 4 or Y-axis side indication line 5 are detected. At every interval of dividing the division marks 7 in the Y-axis direction or X-axis direction by a specific integer value, the code mark 9 of the binary signal recorded in the information are 8 is sequentially read by the code reader 3 up to an end part of the Y-axis side indication line 5 or the X-axis side indication line 4 and the region formed in each square, of which one side is the interval of the division mark 7 is read by the code reader 3, or the length between the division codes divided by an integer value is processed, thereby decoding the code symbol mark 2.

Claims

1. A method of decoding a two-dimensional code symbol mark an information area defined by an X-axis side indication line and a Y-axis side indication line for determining a reading range of the two-dimensional code symbol mark and reading a binary signal of the code symbol mark recorded in the information area, thereby decoding the code symbol mark, wherein the X-axis side indication line or the Y-axis side indication line of the information area, and the division marks recorded on the X-axis side indication line or the Y-axis side indication line are detected by a code reader said method comprising the steps of:

(a) calculating intervals of the divisional marks at every point of the intervals dividing the detection marks up to an end part of the Y-axis side indication line or X-axis side indication line, by dividing a distance between them by a specified integer,

(b) reading and digitally storing the binary signals of the code symbol mark, and

(c) digitally decoding and processing the digitally stored code symbol mark recorded in each region formed in a square of which one side is a length defined by the intervals of the division marks or a division mark spacing divided by an integer value.

2. The method of decoding the two-dimensional symbol mark of claim 1, wherein the X-axis side indication line, the Y-axis side indication line the division marks recorded on the X-axis side indication line, and Y-axis side indication line, and corner marks at diagonal positions of intersections with the X-axis side indication line and Y-axis side indication line of which the code symbol mark is recorded in the information area are individually detected by the code reader,

wherein crossing angles are calculated based on a detection of the X-axis side indication line and Y-axis side indication line, including calculating crossing angles of the X-axis side indication line with a straight line linking an end part of the X-axis side indication line and the corner mark, and calculating crossing angles of the Y-axis side indication line with a straight line linking an end part of the Y-axis side indication line and the corner mark and,

calculating straight lines passing through the division marks of the X-axis side indication line and the Y-axis side indication line, or the points of segmenting the interval of the division marks into a specific number by linear interpolation method, and

calculating region of each square formed by crossing of these straight lines, and

digitally decoding the digitally stored code symbol mark recorded in the information area.

3. The method of decoding the two-dimensional code symbol mark of claim 1 or 2, wherein the code reader is first scanned at rough reading precision to detect the X-axis side indication line, the Y-axis side indication line, and the corner marks at the diagonal positions of the intersections with the X-axis side indication line and Y-axis side indication line of the information area recording the code symbol mark, and

the code reader is scanned at dense reading precision to detect the X-axis side indication line and division marks on the X-axis side indication line, the interval of division marks or the Y-axis side indication line and division marks on the Y-axis side indication line, and an interval of division marks, thereby digitally decoding the digitally stored code symbol mark recorded in the information area specified by the X-axis side indication line and Y-axis side indication line.

4. The method of decoding the two-dimensional code symbol mark of any one of the claims 1 or 2, wherein the code reader is a line sensor or laser scanner of a one-dimensional charged coupled device (CCD).

5. The method of decoding the two-dimensional code symbol mark of claim 1 or 2, wherein digitally reading and storing the binary signals in the information region by the code reader is done at every point of an interval of a middle point of division mark, or at every point of an interval of a middle point between division marks.

6. A decoding method of two-dimensional code symbol mark of claim 1 or 2, wherein

the code reader of a one-dimensional laser scanner is scanned and any one of the X-axis side indication line, the division mark on the X-axis side indication line, the Y-axis side indication line, and the division mark of the Y-axis side indication line of the information area recording the code symbol mark are detected by a detecting portion of a polygon mirror of the code reader, and

the polygon mirror of the code reader of the laser scanner is revolved by 90 degrees, an indication line of a remaining side of the information area and the division marks are detected by other one-dimensional laser scanners installed in an orthogonal direction thereof, and the code symbol mark recorded in the information area specified by the X-axis side indication line and Y-axis side indication line is decoded.

7. The method of decoding the two-dimensional code symbol mark of claim 1 or 2,

wherein two one-dimensional scanners are utilized orthogonal to each other,

one of the one-dimensional scanners is scanned and any one of the X-axis side indication line, the division marks on the X-axis side indication line, the Y-axis side indication line, and the division marks on the Y-axis side indication line of the information area recording the code symbol mark are detected, and

the other one-dimensional scanner is scanned and the indication line of the remaining side of the information area and its division marks are detected, and

the code symbol mark recorded in the information area specified by the X-axis side indication line and Y-axis side indication line is digitally decoded.

8. The method of decoding the two-dimensional code symbol mark of claim 4, wherein each square of which one side is the interval of division marks determines the region of the specified range centered around the middle point of division mark or an extended point from the middle point between division marks, in order to digitally process the code mark recorded in the region.

9. The method of decoding the two-dimensional code symbol mark of claim 1 or 2, wherein each square of which one side is the interval of division mark is the region having the point extended from each end part side of division marks as a corner part, and the code mark recorded in this region is processed.

10. The method of decoding the two-dimensional code symbol mark of claim 1 or 2, wherein the information area is detected by reading the X-axis side indication line, Y-axis side indication line, and an asymmetrical corner mark at the diagonal position of their intersection.

11. The method of decoding the two dimensional code symbol mark of claim 1 or 2, wherein the division mark is as wide as the interval between division marks, and the interval of the division marks is set to a length of the interval between division marks.

12. The method of decoding the two-dimensional code symbol mark of claim 1 or 2, wherein the code symbol marks is written on a magnetic material.

13. The method of decoding the two-dimensional code symbol mark of claim 5, wherein each square of which one side is the interval of division marks determines the region of he specified range centered around the middle point of division mark or an extended point from the middle point between division marks, in order to digitally process the code mark recorded in the region.