Method of generating interface surface

• US 7,380,727 B2
• Filed: 05/16/2007
• Issued: 06/03/2008
• Est. Priority Date: 10/25/2002
• Status: Expired due to Fees

• Current Assignee: Silverbrook Research Pty Limited
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Lapstun, Paul
• Primary Examiner(s): St. Cyr; Daniel
• Application Number:
  US11/749,158
• Publication Number:
  US 20070210176A1
• Time in Patent Office: 384 Days
• Field of Search: 235/494, 235/462.01, 235/462.04, 235/462.38
• US Class Current: 235/494
• CPC Class Codes: G06K 19/06 characterised by the kind of the digital marking, e.g. shape, nature, code
• CPC Class Codes: G06K 19/06009 with optically detectable marking G06K19/063, G06K19/08 take precedence
• CPC Class Codes: G06K 19/06075 the marking containing means for error correction
• CPC Class Codes: G06K 19/06168 the marking being a concentric barcode
• CPC Class Codes: G06K 2019/06243 concentric-code
• 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 7/1421 Circular bar codes
• CPC Class Codes: G06K 7/1456 determining the orientation of the optical code with respect to the reader and correcting therefore
• CPC Class Codes: G06K 7/1473 error correction

Abstract

A method of generating an interface surface is provided, in which machine-readable coded data is generated in a computer system in accordance with a layout and is printed onto a surface with a printer in communication with the computer system. The layout has at least order n rotational symmetry, where n is at least two, and encodes a fault tolerant orientation codeword comprising a sequence of an integer multiple m of n symbols, where m is one or more. Each encoded symbol is distributed at n locations about a center of rotational symmetry of the layout such that decoding the symbols at each of the n orientations of the layout produces n representations of the orientation codeword. Each representation has a different cyclic shift of the orientation codeword and is indicative of the degree of rotation of the layout.

Claims

1. A method of generating an interface surface, including the steps of:

generating, in a computer system, machine-readable coded data in accordance with a layout, the layout having at least order n rotational symmetry, where n is at least two, and encoding a fault tolerant orientation codeword comprising a sequence of an integer multiple m of n symbols, where m is one or more, each encoded symbol being distributed at n locations about a center of rotational symmetry of the layout such that decoding the symbols at each of the n orientations of the layout produces n representations of the orientation codeword, each representation comprising a different cyclic shift of the orientation codeword and being indicative of the degree of rotation of the layout; and

printing, with a printer in communication with the computer system, the coded data onto the surface.

2. A method according to claim 1 wherein the orientation codeword is sufficiently fault tolerant such that each representation of the orientation codeword can be accurately decoded even if one of its symbols is corrupted.

3. A method according to claim 1 wherein the orientation codeword is sufficiently fault tolerant such that each representation of the orientation codeword can be accurately decoded even if two or more of its symbols are corrupted.

4. A method according to claim 1, wherein the layout is repeated on the substrate within a layout region.

5. A method according to claim 4 wherein the layout region comprises a plurality of layouts of two or more layout types, each layout encoding its layout type.

6. A method according to claim 5 encoding a distributed codeword wherein fragments of the distributed codeword are distributed between the two or more layout types in a predetermined manner such that the distributed codeword can be reconstructed from fragments located in a plurality of adjacent layouts of different types.

7. A method according to claim 4, wherein the layouts are packed together on the substrate.

8. A method according to claim 1 wherein the layout encodes a local codeword wherein fragments of the local codeword are distributed within the layout in a predetermined manner such that the local codeword can be reconstructed from the fragments.

9. A method according to claim 1, wherein the coded data is generated to include one or more target features for enabling preliminary location and rotation of the layout to be determined by a machine used to read the coded data.

10. A method according to claim 9, wherein the target features are configured to enable perspective correction of the coded data of the, or each, layout upon reading by the machine.

11. A method according to claim 1, wherein the coded data is printed onto the surface in ink that is of low-visibility or is invisible to an average unaided human eye.

12. A method according to claim 11, wherein the ink is an infrared ink that is substantially invisible to an average unaided human eye.

13. A method according to claim 11, further including printing visible markings on the surface.

14. A surface according to claim 13, wherein the visible marking are disposed adjacent to, or coincident with, at least some of the coded data.

15. A method according to claim 1, wherein the coded data is generated to include location data indicative of a position of the layout pattern relative to a region of the surface.

16. A method according to claim 1, wherein the coded data is generated to include identification data identifying a region of the surface within which the layout is disposed.

17. A method according to claim 1, wherein the coded data is generated to include function data identifying a function to be performed upon reading of the layout pattern or sub-pattern by the machine.