Object location determination

• US 9,170,685 B2
• Filed: 06/20/2013
• Issued: 10/27/2015
• Est. Priority Date: 06/20/2013
• Status: Active Grant

• Current Assignee: Otter Products LLC
• Original Assignee: Otter Products LLC
• Inventors: Spears, Kurt E
• Primary Examiner(s): Pappas, Claire X
• Assistant Examiner(s): CASAREZ, BENJAMIN X.
• Application Number:
  US13/923,174
• Publication Number:
  US 20140375613A1
• Time in Patent Office: 859 Days
• Field of Search: None
• US Class Current: 1/1
• 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 positioned at one location relative to the planar surface, the one location 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, wherein the apparatus does not include a second time-of-flight sensor array; and

electrical circuitry configured to;

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

process the plurality of ranged images to detect a deformation of the object resulting from the object coming into contact with the planar surface, the deformation of the object detected based on both intensity information and distance information included in each of the ranged images captured by the time-of-flight sensor array from the one location;

in response to the detected deformation of the object, process one or more of the ranged images to determine the position of the object on the planar surface by determining an angle and a radius of the position of the object relative to the axis of the conical mirror;

process one or more of the ranged images to detect a physical characteristic of the object and associate a display color with the object based on the detected characteristic; and

transmit the position of the object and the color to a display system.

2. The apparatus of claim 1 wherein the intensity information and distance information included in each of the ranged images includes 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 images include 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 further comprising a battery configured to power the time-of-flight sensor array and the electrical circuitry.

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

6. 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.

7. 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.

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

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

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

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

receiving a series of ranged images captured by a single time of flight sensor through a conical reflector, wherein the time of flight sensor is positioned at one location and 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, wherein a second time of flight sensor is not used in the method;

processing the series of ranged images captured from the one location to detect a deformation of the object resulting from the object contacting the planar surface, wherein each ranged image of the series includes intensity and distance information;

processing one or more of the ranged images to determine the position of the object on the planar surface in response to detecting the deformation by determining an angle and a distance of the object with respect to an axis of the conical reflector;

processing one or more of the ranged images to detect a physical characteristic of the object to associate a parameter with the object; and

transmitting the position of the object and the parameter to a display system.

12. The method of claim 11 wherein the time of flight sensor is positioned with respect to the axis of the conical reflector such that the ranged images include at least a one hundred eighty degree area of the planar surface with respect to the axis of the conical reflector.

13. The method of claim 11 further comprising positioning a telecentric optical element in a path between the time of flight sensor and the conical reflector.

14. The method of claim 11 further comprising processing the series of ranged images to identify a characteristic of a holder of the object.

15. The method of claim 11 further comprising processing the series of ranged images to determine a position of a second object on the planar surface.

16. An information display system comprising:

an electronic display; and

a position determining unit including;

a conical mirror;

a time-of-flight sensor array positioned at a single location with respect to the conical mirror such that a field of view of the time-of-flight sensor array is reflected from the conical mirror in a plurality of directions across a surface of the electronic display, wherein the system does not include a second time-of-flight sensor array; and

one or more computer processors configured to;

receive ranged images captured by the time-of-flight sensor array from the single location through the conical mirror;

process the ranged images 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, wherein the object is determined to be on the surface based on a detected deformation of the object determined based on the ranged images;

process the ranged images to detect a physical characteristic of the object and associate a color with the object based on the detected characteristic; and

transmit the position of the object and the color associated with the object for display on the electronic display.

17. The information display system of claim 16 wherein the object comprises a finger of a user of the information display system.

18. The information display system of claim 16 wherein the object comprises a stylus having a deformable tip.