Rotationally symmetric coded data

• US 7,334,739 B2
• Filed: 05/30/2006
• Issued: 02/26/2008
• Est. Priority Date: 09/17/1999
• 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): Stcyr; Daniel
• Application Number:
  US11/442,366
• Publication Number:
  US 20060214013A1
• Time in Patent Office: 637 Days
• Field of Search: 235/494, 23546201- 49
• US Class Current: 235/494
• CPC Class Codes: G06F 3/0321 by optically sensing the absolute position with respect to a regularly patterned surface forming a passive digitiser, e.g. pen optically detecting position indicative tags printed on a paper sheet constructional details of pen-shaped pointing devices G06F3/03545, G06F3/03542, G06F3/037
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06K 19/06046 Constructional details
• CPC Class Codes: G06K 19/06075 the marking containing means for error correction

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, the layout including n identical sub-layouts rotated 1/n revolutions apart about the center of rotation, each sub-layout encoding a codeword formed from a number of data elements, the sub-layout defining the position of the data elements, and including rotation-indicating data that distinguishes that sub-layout from at least one other sub-layout.

Claims

1. 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, the layout including n identical sub-layouts rotated 1/n revolutions apart about the center of rotation, each sub-layout encoding a codeword formed from a number of data elements, the sub-layout defining the position of the data elements, and including rotation-indicating data that distinguishes that sub-layout from at least one other sub-layout.

2. The coded data of claim 1, the sub-layouts being arranged such that each data element has a unique position.

3. The coded data of claim 1, the positions of the data elements of respective sub-layouts being interleaved.

4. The coded data of claim 1, the coded data including a plurality of layouts, each layout having at least one codeword that is different to at least one codeword of at least one other layout.

5. The coded data of claim 1, the coded data including a plurality of layouts, each layout having at least one codeword that is identical to at least one codeword of at least one other layout.

6. The coded data claim 1, each sub-layout having at least one codeword that is different to at least one codeword of at least one other sub-layout.

7. The coded data of claim 1, each sub-layout having at least one codeword that is identical to at least one codeword of at least one sub-layout.

8. The coded data being coded data according to claim 1.

14. A surface according to claim 12, the surface being a surface according to claim 1.

9. A surface bearing machine-readable coded 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, the layout including n identical sub-layouts rotated 1/n revolutions apart about the center of rotation, each sub-layout encoding a codeword formed from a number of data elements, the sub-layout defining the position of the data elements, and including rotation-indicating data that distinguishes that sub-layout from at least one other sub-layout.

10. A surface according to claim 9, the coded data being substantially invisible to the unaided human eye.

11. A surface according to claim 9, the surface further including additional visible markings.

12. A surface according to claim 9, the surface being configured as an interface surface for enabling user interaction with a computer.

13. A surface according to claim 12, the surface including at least one region and the coded data representing an identity of at least one region.

15. 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, the layout including n identical sub-layouts rotated 1/n revolutions apart about the center of rotation, each sub-layout defining the position of the data elements, and including rotation-indicating data that distinguishes that sub-layout from at least one other sub-layout.

(c) printing the coded data onto a surface.

16. A method according to claim 15, the coded data being substantially invisible to the unaided human eye.

17. A method according to claim 15, the surface further including additional visible markings, the method including printing visible markings on the surface substantially simultaneously with the coded data.

18. A method according to claim 15, the method being a method according to claim 15.

23. A method according to claim 19, the method being a method according to claim 15.

19. A method of using a sensing device to read machine-readable coded data, the coded data being arranged in accordance with at least one layout having n-fold rotational symmetry about a centre of rotation, where n is at least two, the layout including n identical sub-layouts rotated 1/n revolutions apart about the center of rotation, each sub-layout encoding a codeword formed from a number of data elements, the sub-layout defining the position of the data elements, and including rotation-indicating data that distinguishes that sub-layout from at least one other sub-layout.

(a) sensing at least one layout using the sensing device;

(b) decoding the coded data of at least one of the sub-layouts of the sensed layout, thereby determining at least the rotation-indicating data of that sub-layout; and

(c) using the rotation-indicating data to interpret the meaning of at least some of the coded data.

20. A method according to claim 19, each layout including at least one target feature representing at least a position and a rotation of the layout, the method of reading the coded data including:

(a) imaging the surface to generate an image thereof;

(b) processing the image to locate one or more target features; and

(c) on the basis of the located target features, determining at least one of the position and the rotation of at least one of the sub-layouts.

21. A method according to claim 19, each layout including a codeword, the codeword being encoded in each sub-layout, the method including decoding the codeword from at least one of the sub-layouts.

22. A method according to claim 19, at least one sub-layout including type-indicating data, the method including:

(a) determining at least the type-indicating data of the at least one sub-layout; and

,

(b) using the type indicating data to interpret the meaning of at least some of the coded data.