ELECTRONIC PEN HAVING FAST RESPONSE TIME

• US 20090315863A1
• Filed: 06/03/2009
• Published: 12/24/2009
• Est. Priority Date: 06/23/2008
• Status: Active Grant

• Current Assignee: Silverbrook Research Pty Limited
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia, Lapstun, Paul, Underwood, Matthew John, Brice, Robert John, Szarka-Kovacs, Zsolt
• Granted Patent: US 8,366,338 B2
• Time in Patent Office: Days
• US Class Current: 345/179
• 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

Abstract

An electronic pen for interacting with a surface. The pen comprises a cartridge having a nib for contacting the surface, a capacitive force sensor cooperating with said cartridge for sensing a nib force transmitted axially through the cartridge, and a processor configured to generate force data indicative of a force detected by the force sensor. The capacitive force sensor comprises: a spring having an integral conductive moving plate resiliently biased towards a reference position, a conductive fixed plate and a dielectric separating said plates.

Claims

1. An electronic pen for interacting with a surface, said pen comprising:

a cartridge having a nib for contacting said surface;

a capacitive force sensor, cooperating with said cartridge, for sensing a nib force transmitted axially through said cartridge; and

a processor configured to generate force data indicative of a force detected by said force sensor,

wherein said capacitive force sensor comprises;

a spring having an integral conductive moving plate, said spring resiliently biasing said moving plate towards a reference position;

a conductive fixed plate; and

a dielectric separating said plates.

2. The electronic pen of claim 1, wherein said spring is configured to return said moving plate to said reference position in less than 5 milliseconds.

3. The electronic pen of claim 1, wherein said spring is comprised of a material selected from the group consisting of:

stainless steel and beryllium-copper alloy.

4. The electronic pen of claim 1, wherein said nib force moves said moving plate towards said fixed plate.

5. The electronic pen of claim 1, wherein said nib force moves said moving plate away from said fixed plate.

6. The electronic pen of claim 1, wherein said spring comprises one or more spring arms supporting said moving plate.

7. The electronic pen of claim 6, wherein said one or more spring arms extend radially, circumferentially or spirally from said moving plate to an outer annular support.

8. The electronic pen of claim 6, wherein said moving plate and said one or more spring arms are coplanar in said reference position.

9. The electronic pen of claim 6, wherein said moving plate and said one or more spring arms are formed from a single blank of material.

10. The electronic pen of claim 1, wherein said dielectric comprises air and a polymer.

11. The electronic pen of claim 10, wherein said polymer is polyimide.

12. The electronic pen of claim 1, said moving plate and said fixed plate are separated by a rigid spacer.

13. The electronic pen of claim 1, wherein said nib is retractable within a body of said pen.

14. The electronic pen of claim 13, wherein said cartridge is coupled to said force sensor via a retraction mechanism.

15. The electronic pen of claim 14, wherein said retraction mechanism comprises a user-operable button for retracting and extending said nib.

16. The electronic pen of claim 1, wherein said force data is captured as a continuous stream of sensed forces during a pen stroke.

17. The electronic pen of claim 1, wherein said force data is indicative of whether a predetermined threshold force has been detected by said force sensor.

18. The electronic pen of claim 1, wherein said cartridge is selected from any one of:

an ink cartridge comprising an ink reservoir for supplying ink to said nib, wherein said nib is a marking nib; and

a stylus cartridge wherein said nib is a non-marking nib.

19. The electronic pen of claim 1 further comprising an image sensor for imaging a coded data pattern disposed on said surface, wherein said processor is further configured for generating interaction data using imaged coded data pattern.

20. The electronic pen of claim 19, wherein said processor is configured to generate said interaction data only if said force data indicates that said nib is in contact with said surface.