Active Sensing Device Configured To Capture And Decode Infrared (IR) Position Tags From A Page

• US 20080110988A1
• Filed: 01/16/2008
• Published: 05/15/2008
• Est. Priority Date: 09/17/1999
• Status: Active Grant

• Current Assignee: Silverbrook Research Pty Limited
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia, Lapstun, Paul
• Granted Patent: US 7,542,629 B2
• Time in Patent Office: Days
• US Class Current: 235/439
• 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

The invention relates to an active sensing device configured to capture and decode infrared (IR) position tags from a page. The sensing device includes a force sensor photodiode configured to sense when a portion of the device is in contact with the page, and an image sensor configured to image a part of the page proximate the portion when the portion is in contact therewith. Also included is a controller arranged in signal communication with the photodiode and image sensor, said controller configured to control the photodiode and image sensor to capture, decode and encrypt the tags into digital ink data. The device further includes a radio frequency (RF) integrated circuit and antenna configured to securely transmit the digital ink data to a computing system by utilising a pre-registered session key.

Claims

1. An active sensing device configured to capture and decode infrared (IR) position tags from a page, said sensing device comprising:

a force sensor photodiode configured to sense when a portion of the device is in contact with the page;

an image sensor configured to image a part of the page proximate the portion when the portion is in contact therewith;

a controller arranged in signal communication with the photodiode and image sensor, said controller configured to control the photodiode and image sensor to capture, decode and encrypt the tags into digital ink data; and

a radio frequency (RF) integrated circuit and antenna configured to securely transmit the digital ink data to a computing system by utilising a pre-registered session key.

2. The sensing device of claim 1, which includes a pair of orthogonal accelerometers configured so that the controller is able to sense motion without reference to the position tags by sensing acceleration in x and y directions and integrating with respect to time to produce an instantaneous velocity and position.

3. The sensing device of claim 1, wherein the image sensor is configured to image in the infrared spectrum.

4. The sensing device of claim 1, wherein the force sensor photodiode is configured to sense force as a continuous value.

5. The sensing device of claim 1, including a status LED to indicate a status of the device to a user.

6. The sensing device of claim 1, wherein the RF integrated circuit is configured to operate in a 2.4 GHz radio frequency band with the controller utilising frequency hopping and collision detection techniques to provide interference-free communication.

7. The sensing device of claim 1, wherein the controller includes a buffer and is configured to buffer digital ink data when the device is out-of-range of the computing system and to transmit the buffered digital ink data when the device is once again within range of the computing system.