OBJECT LOCATION DETERMINATION

• US 20140375613A1
• Filed: 06/20/2013
• Published: 12/25/2014
• Est. Priority Date: 06/20/2013
• Status: Active Grant

• Current Assignee: Otter Products LLC
• Original Assignee: 1 Oak Technologies LLC
• Inventors: SPEARS, KURT E.
• Granted Patent: US 9,170,685 B2
• Time in Patent Office: Days
• US Class Current: 345/175
• CPC Class Codes: G06F 2203/04104 Multi-touch detection in digitiser, i.e. details about the simultaneous detection of a plurality of touching locations, e.g. multiple fingers or pen and finger
• CPC Class Codes: G06F 3/0425 using a single imaging device like a video camera for tracking the absolute position of a single or a plurality of objects with respect to an imaged reference surface, e.g. video camera imaging a display or a projection screen, a table or a wall surface, on which a computer generated image is displayed or projected tracking a projected light spot to determine a position on a display surface G06F3/0386
• CPC Class Codes: G06F 3/0428 by sensing at the edges of the touch surface the interruption of optical paths, e.g. an illumination plane, parallel to the touch surface which may be virtual sensing beam interruptions in a planar beam grid of an optical touch-screen G06F3/0421

Abstract

An apparatus for determining a position of an object on a planar surface is provided. The apparatus includes a conical mirror having an axis that is perpendicular to the planar surface and a time-of-flight sensor array having a spatial relationship to the conical mirror such that a field of view of the time of flight sensor array is reflected radially from the conical mirror in a plurality of directions across the planar surface. The apparatus also includes electrical circuitry configured to receive a ranged image captured by the time-of-flight sensor array through the conical mirror, process the ranged image to determine the position of the object on the planar surface by determining an angle and a radius of the object relative to the axis of the conical mirror, and transmit the position of the object to a display system.

Claims

1. An apparatus for determining a position of an object on a planar surface, the apparatus comprising:

a conical mirror having an axis that is about perpendicular to a planar surface;

a time-of-flight sensor array having a spatial relationship to the conical mirror such that a field of view of the time-of-flight sensor array is reflected radially from the conical mirror in a plurality of directions across the planar surface;

electrical circuitry configured to;

receive a ranged image captured by the time-of-flight sensor array through the conical mirror, the ranged image including the object;

process the ranged image to determine the position of the object on the planar surface by determining an angle and a radius of the object relative to the axis of the conical mirror; and

transmit the position of the object to a display system.

2. The apparatus of claim 1 wherein the ranged image includes both intensity information and distance information associated with each of two or more of a plurality of pixels of the time-of-flight sensor array.

3. The apparatus of claim 1 wherein the time-of-flight sensor array is positioned with respect to the axis of the conical mirror such that the ranged image includes at least a one hundred eighty degree area of the planar surface with respect to the axis of the conical mirror.

4. The apparatus of claim 1 wherein the object is an electronic stylus and the electrical circuitry is further configured to receive a communication from the electronic stylus indicating whether the electronic stylus is in contact with the planar surface.

5. The apparatus of claim 4 wherein the communication is received from the electronic stylus through a wireless communication interface.

6. The apparatus of claim 1 further comprising a battery configured to power the time-of-flight sensor array and the electrical circuitry.

7. The apparatus of claim 1 wherein the time-of-flight sensor array includes a radio frequency modulated light source and a phase detector.

8. The apparatus of claim 1 wherein the time-of-flight sensor array includes a pulsed light source and a shutter synchronized with the pulsed light source.

9. The apparatus of claim 1 further comprising a telecentric optical element positioned in an optical path between the time-of-flight sensor array and the conical mirror.

10. The apparatus of claim 1 wherein the conical mirror is a conical aspheric mirror.

11. The apparatus of claim 1 wherein the electrical circuitry is further configured to process the ranged image to identify a characteristic of a holder of the object.

12. The apparatus of claim 1 wherein the electrical circuitry is further configured to process the ranged image to determine a position of a second object on the planar surface.

15. The method of claim 1 further comprising positioning a telecentric optical element in a path between the time of flight sensor and the conical reflector.

16. The method of claim 1 further comprising processing the ranged image to identify a characteristic of a holder of the object.

17. The method of claim 1 further comprising processing the ranged image to determine a position of a second object on the planar surface.

13. A method for determining a position of an object on a planar surface, the method comprising:

receiving a ranged image captured by a time of flight sensor through a conical reflector, wherein a field of view of the time of flight sensor is radially reflected from the conical reflector across the planar surface in a plurality of directions;

processing the ranged image to determine the position of the object on the planar surface by determining an angle and a distance of the object with respect to an axis of the conical reflector; and

transmitting the position of the object to a display system.

14. The method of claim 13 wherein the time of flight sensor is positioned with respect to the axis of the conical reflector such that the ranged image includes at least a one hundred eighty degree area of the planar surface with respect to the axis of the conical reflector.

18. An information display system comprising:

an electronic display; and

a position determining unit including;

a conical mirror;

a time-of-flight sensor array positioned with respect to the conical mirror such that a field of view of the time-of-flight sensor is reflected from the conical mirror in a plurality of directions across a surface of the electronic display; and

one or more computer processors configured to;

receive a ranged image captured by the time-of-flight sensor array through the conical mirror;

process the ranged image to determine a position of an object on the surface of the electronic display by determining an angle and a radius of the object relative to an axis of the conical mirror; and

transmit the position of the object for display on the electronic display.

19. The information display system of claim 18 wherein the one or more computer processors are further configured to determine the position of the object on the surface only if the object is in contact with the surface.

20. The information display system of claim 19 wherein the one or more computer processors are further configured to determine if the object is in contact with the surface based on the ranged image.