Symmetric tags

• US 7,564,605 B2
• Filed: 02/26/2004
• Issued: 07/21/2009
• Est. Priority Date: 03/04/2003
• Status: Expired due to Fees

• Current Assignee: Silverbrook Research Pty Limited
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia, Lapstun, Paul
• Primary Examiner(s): Zimmerman; Mark K
• Assistant Examiner(s): Chen; Huo Long
• Application Number:
  US10/786,631
• Publication Number:
  US 20040174577A1
• Time in Patent Office: 1,972 Days
• Field of Search: 358/539, 358/448, 235/494, 235/462.03, 235/375
• US Class Current: 358/539
• CPC Class Codes: G06K 19/06037 multi-dimensional coding

Abstract

Coded data for disposal on or in a surface, the coded data being arranged in accordance with at least one layout having n-fold rotational symmetry about a center of rotation, where n is at least two, and having mirror symmetry, the layout including:

• • (a) n identical first sub-layouts rotated 1/n revolutions apart about the center of rotation, and,
  • (b) n identical second sub-layouts rotated 1/n revolutions apart about the center of rotation, each second sub-layout being a reflection of a corresponding one of the first sub-layouts, at least one sub-layout including:
    • (i) rotation-indicating data that distinguishes that sub-layout from at least one other sub-layout; and,
    • (ii) reflection-indicating data that distinguishes the reflection of that sub-layout from the reflection of a corresponding reflected sub-layout.

Claims

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

(a) receiving user data in a printer;

(b) generating machine-readable coded data incorporating the user data, the coded data being arranged in accordance with at least one layout having n-fold rotational symmetry about a center of rotation, where n is at least two, and having mirror symmetry, the layout including;

(i) n identical first sub-layouts rotated 1/n revolutions apart about the center of rotation, and,

(ii) n identical second sub-layouts rotated 1/n revolutions apart about the center of rotation, each second sub-layout being a reflection of a corresponding one of the first sub-layouts, at least one sub-layout including;

(1) rotation-indicating data that distinguishes that sub-layout from at least one other sub-layout; and

,

(2) reflection-indicating data that distinguishes the reflection of that sub-layout from the reflection of a corresponding reflected sub-layout; and

(c) printing the coded data onto a surface.

2. A method according to claim 1, the coded data being substantially invisible to the unaided human eye.

3. A method according to claim 1, the surface further including additional visible markings, the method including printing visible markings on the surface substantially simultaneously with the coded data.