Method of estimating nib position using images captured at different pen rotations

• US 8,319,745 B2
• Filed: 12/29/2009
• Issued: 11/27/2012
• Est. Priority Date: 02/24/2000
• Status: Expired due to Fees

• Current Assignee: Silverbrook Research Pty Limited
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Lapstun, Paul, Silverbrook, Kia, King, Tobin Allen
• Primary Examiner(s): Abdulselam, Abbas
• Application Number:
  US12/649,303
• Publication Number:
  US 20100101873A1
• Time in Patent Office: 1,064 Days
• Field of Search: 345/166, 345/173, 345/179, 178/18.01, 178/18.03, 178/18.09, 178/19.05, 382/181
• US Class Current: 345/173
• CPC Class Codes: B41J 13/106 for the sheet output section
• CPC Class Codes: B41J 2/17513 Inner structure
• CPC Class Codes: B42C 19/02 starting with single sheets
• CPC Class Codes: B42C 9/0006 by applying adhesive to a stack of sheets
• CPC Class Codes: B42C 9/0081 applying adhesive to individual sheets for binding them together by fusing, welding B42C9/0093
• CPC Class Codes: B42P 2261/04 Producing books by printing sheets in following order, e.g. for ordering via the Internet
• CPC Class Codes: B65H 29/34 from supports slid from under the articles
• CPC Class Codes: B65H 37/04 for securing together articles or webs, e.g. by adhesive, stitching or stapling adhering replacement to expiring web during change of web roll B65H19/18
• CPC Class Codes: G06F 3/033 Pointing devices displaced or positioned by the user , e.g. mice, trackballs, pens or joysticks; Accessories therefor digitisers characterised by the transducing means G06F3/041
• CPC Class Codes: G06F 40/169 Annotation, e.g. comment data or footnotes
• CPC Class Codes: G06Q 10/10 Office automation; Time management
• CPC Class Codes: G06Q 20/085 involving remote charge determination or related payment systems
• CPC Class Codes: G06Q 20/10 specially adapted for electronic funds transfer [EFT] systems; specially adapted for home banking systems
• CPC Class Codes: G06Q 20/40 Authorisation, e.g. identification of payer or payee, verification of customer or shop credentials; Review and approval of payers, e.g. check credit lines or negative lists
• CPC Class Codes: G06Q 30/0241 Advertisements
• CPC Class Codes: G06Q 40/00 Finance; Insurance; Tax strategies; Processing of corporate or income taxes
• CPC Class Codes: G06V 10/19 by sensing codes defining pattern positions
• CPC Class Codes: G06V 10/225 based on a marking or identifier characterising the area
• CPC Class Codes: G06V 30/1423 the instrument generating sequences of position coordinates corresponding to handwriting preprocessing or recognising digital ink G06V30/32
• CPC Class Codes: H04L 65/4015 where at least one of the additional parallel sessions is real time or time sensitive, e.g. white board sharing, collaboration or spawning of a subconference
• CPC Class Codes: H04L 67/131 : Protocols for games, networked simulations or virtual reality
• CPC Class Codes: H04L 67/52 : specially adapted for the location of the user terminal
• CPC Class Codes: H04W 4/02 : Services making use of location information

Abstract

A method of estimating a position of nib of a pen relative to an optical sensor mounted on the pen. The method comprises the steps of: (a) placing the nib in contact with a coded surface; (b) capturing, using the sensor, at least two images of the coded surface at different rotations of the pen relative to the surface; (c) determining, from a perspective distortion of the coded surface in each image, an estimated rotation and viewing distance for each image; and (d) estimating, from the estimated rotations and viewing distances, the position of the nib relative to the optical sensor.

Claims

1. A method of estimating a position of nib of a pen relative to an optical sensor mounted on the pen, said method comprising the steps of:

placing the nib in contact with a coded surface;

capturing, using the sensor, at least two images of the coded surface at different rotations of the pen relative to the surface;

determining, from a perspective distortion of the coded surface in each image, an estimated rotation and viewing distance for each image; and

estimating, from the estimated rotations and viewing distances, the position of the nib relative to the optical sensor.

2. The method of claim 1, comprising the steps of:

generating a line for each rotation using a corresponding estimated rotation and viewing distance;

intersecting the at least two lines generated; and

estimating, from at least one point of intersection of the lines, the position of the nib relative to the sensor.

3. The method of claim 1, wherein the coded surface comprises coded data identifying a plurality of locations on the surface.

4. The method of claim 3, wherein the coded data is defined by a plurality of printed tags, each tag containing coded data identifying the surface and its own location on the surface.

5. The method of claim 1, wherein each rotation is defined by at least one of a pitch, roll or yaw component.

6. The electronic pen of claim 1, wherein the nib is marking nib or a non-marking nib.

7. An electronic pen comprising:

a body;

a nib at one end of the body for contacting a coded surface;

an optical sensor mounted on the body for capturing images of the coded surface; and

a processor configured for;

determining, from a perspective distortion of the coded surface in at least two images captured at different rotations, an estimated rotation and viewing distance for each image; and

estimating, from the estimated rotations and viewing distances, the position of the point relative to the optical sensor.

8. The electronic pen of claim 7, wherein the processor is configured for:

generating a line for each rotation using a corresponding estimated rotation and viewing distance;

intersecting the at least two lines generated; and

estimating, from at least one point of intersection, the position of the nib relative to the sensor.

9. The electronic pen of claim 8, wherein the optical sensor is detachably mounted on the body.