Surface Having Optically Readable Printed Tags

• US 20090294544A1
• Filed: 08/05/2009
• Published: 12/03/2009
• Est. Priority Date: 06/30/2000
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Lapstun, Paul, Walmsley, Simon Robert
• Granted Patent: US 7,997,504 B2
• Time in Patent Office: Days
• US Class Current: 235/494
• CPC Class Codes: G06K 1/121 by printing code marks applying code marks to labels B65C9/46; marking or coding completed packages B65B61/26
• CPC Class Codes: G06K 19/06 characterised by the kind of the digital marking, e.g. shape, nature, code
• CPC Class Codes: G06K 19/06037 multi-dimensional coding
• CPC Class Codes: G06K 19/06168 the marking being a concentric barcode
• CPC Class Codes: G06K 2019/06262 with target- or other orientation-indicating feature
• CPC Class Codes: G06K 7/1417 2D bar codes
• CPC Class Codes: G06K 7/1421 Circular bar codes
• 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 surface having an optically readable pattern of dots printed thereon. The pattern comprises an arbitrarily shaped constant background pattern of dots and/or blanks. The constant background pattern defines discrete areas of coded data represented by a plurality of dots positioned according to an encoding scheme. Each discrete area contains orientation information for enabling an optical reader to determine an orientation relative to the pattern of dots.

Claims

1. A surface having optically readable tags printed thereon, each tag comprising:

a background pattern of markings and/or blanks, said background pattern being common to all tags and defining discrete areas;

coded data positioned within said discrete areas, said coded data being represented by a plurality of dots positioned according to an encoding scheme; and

orientation information positioned within said discrete areas, the orientation information being indicative of a rotational orientation of the tag.

2. The surface of claim 1, wherein each discrete area further contains features usable by an optical reader to determine a perspective distortion of the tag.

3. The surface of claim 1, wherein the background pattern of markings and/or blanks is distinguishable from the coded data and orientation information.

4. The surface of claim 1, wherein the coded data in each discrete area is redundantly encoded by the plurality of dots.

5. The surface of claim 4, wherein the coded data is encoded by Reed-Solomon codewords.

6. The surface of claim 1, wherein the coded data within each discrete area identifies a page identity which is common to each discrete area on the surface.

7. The surface of claim 6, wherein the coded data varies between each tag.

8. The surface of claim 1, wherein said tags are printed with an infrared absorbing ink.