Cursor control device

• US 9,298,279 B2
• Filed: 09/17/2010
• Issued: 03/29/2016
• Est. Priority Date: 12/20/2002
• Status: Active Grant

• Current Assignee: ITAC Systems, Inc.
• Original Assignee: ITAC Systems, Inc.
• Inventors: Bynum, Donald P., Magel, Gregory A., Dawes, Robert Leo, Moore, Larry V., Ahmed, Minhaj
• Primary Examiner(s): Nguyen, Jimmy H
• Application Number:
  US12/924,006
• Publication Number:
  US 20110128220A1
• Time in Patent Office: 2,020 Days
• Field of Search: 345156-184
• US Class Current: 1/1
• CPC Class Codes: G06F 2203/0338 Fingerprint track pad, i.e. fingerprint sensor used as pointing device tracking the fingertip image
• CPC Class Codes: G06F 3/0312 for tracking the rotation of a spherical or circular member, e.g. optical rotary encoders used in mice or trackballs using a tracking ball or in mouse scroll wheels tracking relative movement in co-operation with a regularly or irregularly patterned surface, e.g. as in optical mice G06F3/0317; constructional details of scroll or thumb-wheels G06F3/0362; optical rotary encoders G01D5/3473
• CPC Class Codes: G06F 3/0317 in co-operation with a patterned surface, e.g. absolute position or relative movement detection for an optical mouse or pen positioned with respect to a coded surface
• 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 3/03547 Touch pads, in which fingers can move on a surface
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

A cursor control device having a light source and an image sensor for optically tracking motion. The device includes an upwardly facing dome or window that provides a visual and tactile interface for user interaction. The user'"'"'s hand or finger, bare or gloved, or other object controlled by the user, can be moved in close proximity or touching the dome, and means are provided to discriminate against the motion of objects that are not close to the dome in order to prevent unwanted cursor motion. Said means can include optics having a limited depth of focus, adaptive illumination processing for controlling the intensity of light emitted from the light source to optimize sensor operation, and/or processing for projecting cursor motion in accordance with a detected level of confidence in the sensor data.

Claims

1. A cursor control device comprising:

a light source for illuminating a sensitive region;

a sensor for sensing a motion of an object in the sensitive region;

a confidence calculation section for determining a tracking confidence value using illumination information received from the sensor;

a projection calculation section for determining a projected tracking value using a historical tracking value; and

an enhancement calculation section for determining an enhanced tracking value using the tracking confidence value, the projected tracking value and a measured tracking value, the measured tracking value being representative of the motion sensed by the sensor;

wherein when the tracking confidence value is equal to zero, the enhanced tracking value is equal to the projected tracking value; and

,

wherein when the tracking confidence value is equal to a value between zero and one, the enhanced tracking value is equal to a sum of the measured tracking value and the projected tracking value.

2. A cursor control device according to claim 1, wherein the sensor provides a pair of measured tracking values representative of the sensed motion, wherein the projection calculation section determines a pair of projected tracking values using respective historical tracking values, and wherein the enhancement calculation section determines a pair of enhanced tracking values, each of the pair of enhanced tracking values being calculated using the tracking confidence value, a respective one of the pair of historical tracking values, and a respective one of the pair of measured tracking values.

3. A cursor control device according to claim 2, wherein each of the pair of measured tracking values, projected tracking values, historical tracking values, and enhanced tracking values is representative of motion in a respective one of a pair of orthogonal directions.

4. A cursor control device according to claim 1, wherein the confidence calculation uses illumination information received from the sensor that includes a shutter value and uses a brightness value indicative of an amount of light emitted from the light source.

5. A cursor control device according to claim 1, wherein the measured tracking value is representative of motion sensed by the sensor during a subject sensor scan, and the historical tracking value is related to at least one sensor scan prior to the subject sensor scan.

6. A cursor control device according to claim 5, wherein the historical tracking value is calculated using the enhanced tracking value for said at least one sensor scan prior to the subject sensor scan.

7. A cursor control device according to claim 5, wherein the illumination information is representative of an intensity of light sensed by the sensor during the subject sensor scan.

8. A cursor control device according to claim 1, further comprising a memory for storing the enhanced tracking value.

9. A cursor control device according to claim 8, wherein the projection calculation section uses a previously stored enhanced tracking value as a basis for determining the historical tracking value.

10. A cursor control device according to claim 1, wherein the enhanced tracking value is calculated such that if the tracking confidence value is a first value then the enhanced tracking value is equal to the measured tracking value, and if the tracking confidence value is a second value then the enhanced tracking value is equal to the projected tracking value.

11. A cursor control device according to claim 10, wherein the enhanced tracking value is calculated such that if the tracking confidence value is a third value then the enhanced tracking value equals a weighted combination of each of the measured tracking value and the projected tracking value.

12. A cursor control device according to claim 1, further comprising an adaptive illumination control section for controlling the intensity of light emitted by the light source.

13. A cursor control device according to claim 12, wherein the adaptive illumination control section controls the intensity of light in order to optimize the dynamic range of the sensor.

14. A cursor control device according to claim 12, wherein the adaptive illumination control section controls the intensity of light based on a shutter value signal received from the sensor.

15. A cursor control device according to claim 12, wherein the adaptive illumination control section controls the intensity of light based on a contrast signal received from the sensor.

16. A cursor control device according to claim 12, wherein the illumination information is based on the illumination information received from the sensor and an intensity at which the adaptive illumination control section is controlling the light source.

17. A cursor control device according to claim 1,

wherein the historical tracking value is updated with the enhanced tracking value;

wherein the enhanced tracking value is calculated based on the equation;

dx=(Mdx)*alpha+(1.0−

alpha)*Pdx

wherein dx is the enhanced tracking value,

wherein Mdx is the measured tracking value,

wherein alpha is the tracking confidence value in a range from 0 to 1, and

wherein Pdx is the projected tracking value;

wherein the tracking confidence value is used to retard a tangential speed according to a parameter beta when the tracking confidence value indicates the measured tracking value is unreliable;

wherein the tracking confidence value indicates the measured tracking value is unreliable when the tracking confidence value is less than 1; and

,

wherein the projected value is determined based on the retarded tangential speed that is determined according to the equation;

newspeed=oldspeed*(beta+alpha*(1.0−

beta*alpha))

wherein newspeed is the retarded tangential speed, and

wherein oldspeed is the tangential speed.