Digital data reader of digital data recording sheet

• US 5,408,543 A
• Filed: 06/17/1994
• Issued: 04/18/1995
• Est. Priority Date: 08/02/1989
• Status: Expired due to Term

• Current Assignee: Teiryo Sangyo Company Limited
• Original Assignee: Teiryo Sangyo Company Limited
• Inventors: Yoshida, Hirokazu
• Primary Examiner(s): Mancuso, Joseph
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US08/262,321
• Time in Patent Office: 305 Days
• Field of Search: 382/61, 382/46, 382/44, 382/45, 395/137, 235/494, 235/495
• US Class Current: 382/317
• CPC Class Codes: G06K 7/015 Aligning or centering of the sensing device with respect to the record carrier
• 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
• CPC Class Codes: G06K 7/1456 determining the orientation of the optical code with respect to the reader and correcting therefore

Abstract

A system and method for locating and reading digital data in data regions within a data field disposed on a surface of an object to be identified include the capability of compensating for optical or physical distortions of the data field as viewed by an optical reader. The data field is defined by X-axis and Y-axis intersecting basic lines disposed at a predetermined angle with respect to each other and a corner mark disposed on the opposite side of the data field from those basic lines. A plurality of positions marks for marking predetermined distances between a plurality of imaginary X and Y axis internal lines are also provided. The positions of the imaginary X-axis internal lines within the data field are determinable from their spacings and angles with respect to the Y-axis basic line. The positions of the imaginary Y-axis internal lines are determinable from their spacings and their angles with respect to the X-axis basic line. The location of the points of intersection of the imaginary X and Y axis internal lines are calculated in order to define data regions within the data field. The system and method compensate for optical and physical distortions of the locations of the X and Y axis basic lines, corner mark and position marks at the time of reading the data in order to accurately locate positions of the data regions within the data field.

Claims

1. A system for locating and reading digital data in data regions within a data field on a surface and compensating for optical or physical distortions of the data field viewed by an optical reader comprising:

means for defining the data field by providing x-axis and y-axis intersecting basic lines disposed at a predetermined angle with respect to each other and a corner mark on said surface, the corner mark together with the basic lines defining a data field therebetween;

means for defining the positions of a plurality of imaginary x-axis internal lines within said data field, said x-axis internal lines being spaced at predetermined distances from each other, said x-axis internal lines being disposed at predetermined angles with respect to said y-axis basic line;

means for defining the positions of a plurality of imaginary y-axis internal lines within said data field, said y-axis internal lines being spaced at predetermined distances from each other, said y-axis internal lines being disposed at predetermined angles with respect to said x-axis basic line;

means for calculating the location of the points of intersection of the imaginary x and y axis internal lines at the time of reading said data from the angle between the x and y axis basic line, the angles of the x-axis internal lines with respect to the y-axis basic line, and the angles of the y-axis internal lines with respect to the x-axis basic line;

means for locating said data regions within said data field from the calculated locations of the points of intersection of the x and y axis internal lines at the time of reading; and

means for reading the digital data within said data regions;

whereby optical and physical distortions of the locations of the x and y axis basic lines, and corner mark are compensated for at the time of reading the data in order to accurately locate positions of the data regions within the data field.

2. The system of claim 1, said means for defining the data field further providing an X-axis external line and a Y-axis external line disposed on the opposite side of the data field from said X-axis and Y-axis intersecting basic lines, respectively, for further defining the data field therebetween.

5. The system of claim 1, the angles of the plurality of imaginary Y-axis internal lines with respect to said X-axis basic line being:

##EQU5## where;

Θ

_o =an angle formed by the intersection of said X-axis basic line and said Y-axis basic line,

Θ

_x =an angle formed by the intersection of said X-axis basic line and said Y-axis external line,

M_BX =the number of X-axis internal line position marks plus one, and

n=an index used to denote the specific Y-axis internal line being calculated; and

the angles of the plurality of imaginary X-axis internal lines with respect to said Y-axis basic line being;

##EQU6## where;

Θ

_y =an angle formed by the intersection of said Y-axis basic line and said X-axis external line,

M_BY =the number of Y-axis internal line position marks plus one, and

n=an index used to denote the specific X-axis internal line being calculated.

3. A method for locating and reading digital data in data regions within a data field on a surface and compensating for optical or physical distortions of the data field viewed by an optical reader, comprising the steps of:

defining the data field by providing x-axis and y-axis intersecting basic lines disposed at a predetermined angle with respect to each other and a corner mark on said surface, the corner mark together with the basic lines defining a data field therebetween;

defining the positions of a plurality of imaginary x-axis internal lines within said data field, said x-axis internal lines being spaced at predetermined distances from each other, said x-axis internal lines being disposed at predetermined angles with respect to said y-axis basic line;

defining the positions of a plurality of imaginary y-axis internal lines within said data field, said y-axis internal lines being spaced at predetermined distances from each other, said y-axis internal lines being disposed at predetermined angles with respect to said x-axis basic line;

calculating the location of the points of intersection of the imaginary x and y axis internal lines at the time of reading said data from the angle between the x and y axis basic lines, the angles of the x-axis internal lines with respect to the y-axis basic line and the angles of the y-axis internal lines with respect to the x-axis basic line;

locating said data regions within said data field from the calculated locations of the points of intersection of the x and y axis internal lines at the time of reading; and

reading the digital data within said data regions;

whereby optical and physical distortions of the locations of the x and y axis basic lines and corner mark are compensated for at the time of reading the data in order to accurately locate positions of the data regions within the data field.

4. The method of claim 3, wherein the step of defining the data field further includes providing an X-axis external line and a Y-axis external line disposed on the opposite side of the data field from said X-axis and Y-axis intersecting basic lines, respectively, for further defining the data field therebetween.

6. The method of claim 3, wherein the angles of the plurality of imaginary Y-axis internal lines with respect to the X-axis basic lines being:

##EQU7## where;

Θ

_o =an angle formed by the intersection of said X-axis basic line and said Y-axis basic line,

Θ

_x =an angle formed by the intersection of said X-axis basic line and said Y-axis external line,

M_BX =the number of X-axis internal line position marks plus one, and

n=an index used to denote the specific Y-axis internal line being calculated; and

the angles of the plurality of imaginary X-axis internal lines with respect to the Y-axis basic lines being;

##EQU8## where;

Θ

_y =an angle formed by the intersection of said Y-axis basic line and said X-axis external line,

M_BY =the number of Y-axis internal line position marks plus one, and

m=an index used to denote the specific X-axis internal line being calculated.