MACHINE READABLE CODE TRACK

• US 3,636,317 A
• Filed: 04/28/1969
• Issued: 01/18/1972
• Est. Priority Date: 04/28/1969
• Status: Expired due to Term

• Current Assignee: Bradford M. Torrey
• Original Assignee: Bradford M. Torrey
• Inventors: Torrey, Bradford M.
• Primary Examiner(s): Wilbur, Maynard R.
• Assistant Examiner(s): Sloyan, Thomas J.
• Application Number:
  US04/819,760
• Time in Patent Office: 995 Days
• Field of Search: 235/61.12,61.11,61.11E 340/146.3RR,146.3ID,149A 250/219D,219DC,219DD
• US Class Current: 235/494
• CPC Class Codes: G06K 19/06018 one-dimensional coding
• CPC Class Codes: G06K 2019/06243 concentric-code
• CPC Class Codes: G06K 7/10881 constructional details of hand-held scanners

Abstract

Encoded information is contained in a circular track having sector patterns formed by abutting segments. The segments are all of equal angular extent and extend around the track with each sector containing the same number of segments. Each segment has a binary value and the sequence of binary segments in a sector represents the encoded information. Each different sequence can, for example, represent a different decimal numeral. An encoded '"'"''"'"''"'"''"'"'start'"'"''"'"''"'"''"'"' sector is employed that is not duplicated by any sequence of segments that can occur from assembling the decimal coded sectors in any order whatsoever. The circular track is thereby assured of containing within it only one '"'"''"'"''"'"''"'"'start'"'"''"'"''"'"''"'"' pattern regardless of the other information encoded in the track. The sector codes are chosen so that when the sectors are assembled in abutting relation, no more than two like valued segments occur in succession in the track. The transitions between differently valued segments provide the timing information for decoding the markings.

Claims

1. An article having on it a machine readable, binary coded circular track formed by abutting segments, each segment being coded to have only one or the other of the two binary values whereby the same binary value exists throughout the entire area of the segment, the radial extent of the segment constituting the full width of the track, the abutting segments all being of equal angular extent, the coded track being divided into abutting sectors of equal angular extent whereby each sector has a like plurality of the arcuate segments, each sector having in it segments of both binary values, no more than two like valued segments abutting in succession in any sector, encoded information being represented by the sequence of segments in a sector, and one of the sectors having a start code sequence of segments that is not duplicated within the circular track by any sequential arrangement of the other sectors whatsoever.

2. An article having on it the machine readable, binary coded circular track according to claim 1, further characterized in that self-clocking information is provided in the track by having no more than two like valued segments abut in succession in the encoded track.

3. An article having on it the self-clocking, machine readable, binary coded circular track according to claim 1, further characterized in that any sequential arrangement of the sectors whatsoever places no more than two like valued segments in succession in the track.

4. An article having on it the self-clocking, machine readable, binary coded circular track according to claim 3, further characterized in that the coded sectors begin with two segments of complementary values and end with two segments of complementary values.

5. An article having on it the self-clocking, machine readable, binary coded circular track according to claim 1, further characterized in that the same ratio of segments of one value to segments of the complementary value is present in each encoded sector.

6. An article having on it the self-clocking, machine readable, binary coded circular track according to claim 5, wherein the ratio is one to one.