Enabling physical controls on an illuminated surface

Patent metadata

Field	Value
Publication number	US-10488948-B2
Application number	US-201313828526-A
Country	US
Kind code	B2
Filing date	Mar 14, 2013
Priority date	Mar 14, 2012
Publication date	Nov 26, 2019
Grant date	Nov 26, 2019

Abstract

A method for enabling physical controls in a digital system is provided that includes receiving an image of an illuminated surface in the digital system, wherein the image is captured by a camera in the digital system, determining a state of a physical control mounted on the illuminated surface by analyzing the image; and outputting an indication of the state of the physical control.

First claim

What is claimed is:

1. A method comprising:
projecting, by an infrared light source, infrared light through a rear surface of an illuminated surface of a touch screen display,
receiving a reflection of the projected infrared light as an infrared image, wherein the infrared image is captured by an infrared camera;
identifying a physical control attached to the illuminated surface of the touch screen display by analyzing a reflection of a first binary pattern of the physical control in the infrared image, the physical control having a non-rotatable portion and a rotatable portion, a back surface of the non-rotatable portion of the physical control comprising the first binary pattern and a back surface of the rotatable portion of the physical control comprising a second binary pattern;
determining a rotational state of the physical control attached to the illuminated surface of the touch screen display by analyzing a reflection of the second binary pattern of the physical control in the infrared image; and
outputting an indication of the rotational state of the physical control.

2. The method of claim 1 , further comprising:
outputting an identity indicator for the physical control in association with the rotational state.

3. The method of claim 2 , wherein identifying the physical control comprises:
determining a set of points that lie along the non-rotatable portion of the physical control;
extracting a set of pixel values corresponding to the set of points from the infrared image; and
determining the identity indicator based on the set of pixel values.

4. The method of claim 3 , wherein determining a set of points comprises:
computing the set of points from a sub-image of the infrared image of the illuminated surface captured by the infrared camera, the sub-image corresponding to a pre-determined bounding box specified for the physical control.

5. The method of claim 1 , wherein determining a rotational state of a physical control comprises:
determining a set of points that lie along the rotatable portion of the physical control;
extracting a set of pixel values corresponding to the set of points from the infrared image; and
determining the rotational state based on the set of pixel values.

6. The method of claim 5 , wherein determining a set of points comprises:
computing the set of points from a sub-image of the infrared image of the illuminated surface captured by the infrared camera, the sub-image corresponding to a pre-determined bounding box specified for the physical control.

7. The method of claim 5 , wherein determining the rotational state comprises:
locating a subset of consecutive pixel values of like intensity distinct from other pixel values in the set of pixel values, wherein the subset corresponds to a state indicator encoded on the rotatable portion of the physical control; and
determining the rotational state from a position of the subset corresponding to the state indicator in the set of pixel values.

8. The method of claim 1 , wherein the physical control is a knob, and the rotational state of the physical control is an angle of rotation of the knob.

9. A digital system, comprising:
a touch screen display having an illuminated surface;
a physical control mounted on the illuminated surface of the touch screen display, the physical control having a non-rotatable portion and a rotatable portion, a back surface of the non-rotatable portion of the physical control comprising a first binary pattern and a back surface of the rotatable portion of the physical control comprising a second binary pattern;
an infrared light source configured to project infrared light through a rear surface of the illuminated surface of the touch screen display;
an infrared camera positioned to capture a reflection of the projected infrared light as an infrared image; and
one or more processors configured to:
receive the infrared image captured by the infrared camera;
identify the physical control by analyzing a reflection of the first binary pattern of the physical control in the infrared image;
determine a rotational state of the physical control by analyzing a reflection of the second binary pattern of the physical control in the infrared image; and
output an indication of the rotational state of the physical control.

10. The digital system of claim 9 , wherein the one or more processors are further configured to:
output an identity indicator for the physical control in association with the rotational state.

11. The digital system of claim 10 , wherein the one or more processors are further configured to:
determine a set of points that lie along a fixed portion of the physical control;
extract a set of pixel values corresponding to the set of points from the infrared image; and
determine the identity indicator based on the set of pixel values.

12. The digital system of claim 11 , wherein the one or more processors are further configured to:
compute the set of points from a sub-image of the infrared image of the illuminated surface captured by the infrared camera, the sub-image corresponding to a pre-determined bounding box specified for the physical control.

13. The digital system of claim 9 , wherein the one or more processors are further configured to:
determine a set of points that lie along the rotatable part of the physical control;
extract a set of pixel values corresponding to the set of points from the infrared image; and
determine the rotational state based on the set of pixel values.

14. The digital system of claim 13 , wherein the one or more processors are further configured to:
compute the set of points from a sub-image of the infrared image of the illuminated surface captured by the infrared camera, the sub-image corresponding to a pre-determined bounding box specified for the physical control.

15. The digital system of claim 13 , wherein the one or more processors are further configured to:
locate a subset of consecutive pixel values of like intensity distinct from other pixel values in the set of pixel values, wherein the subset corresponds to a state indicator encoded on the rotatable part of the physical control; and
determine the rotational state from a position of the subset corresponding to the state indicator in the set of pixel values.

16. The system of claim 9 , wherein the physical control is a knob, and the rotational state of the physical control is an angle of rotation of the knob.

17. A non-transitory computer readable medium storing instructions that, when executed by a processor comprised in a digital system, cause the digital system to:
project an infrared light through a rear surface of an illuminated surface of a touch screen display;
receive a reflection of the projected infrared light as an infrared image;
identify a physical control attached to the illuminated surface of the touch screen display by analyzing a reflection of a first binary pattern of the physical control in the infrared image, the physical control having a non-rotatable portion and a rotatable portion, a back surface of the non-rotatable portion of the physical control comprising the first binary pattern and a back surface of the rotatable portion of the physical control comprising a second binary pattern;
determine a rotational state of a physical control by analyzing a reflection of the second binary pattern of the physical control in the infrared image; and
output an indication of the rotational state of the physical control.

18. The computer readable medium of claim 17 , wherein the instructi

Assignees

• Texas Instruments Inc

Inventors

• Sharma Vinay
• Sharp Frank

Classifications

• G06F3/0425

  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 title

• G06F3/02

  Input arrangements using manually operated switches, e.g. using keyboards or dials · CPC title

• G06F3/0362

  with detection of one-dimensional [1D] translations or rotations of an operating part of the device, e.g. scroll wheels, sliders, knobs, rollers or belts · CPC title

• G06F3/0304 Primary

  Detection arrangements using opto-electronic means (constructional details of pointing devices not related to the detection arrangement using opto-electronic means G06F3/033; optical digitisers G06F3/042) · CPC title

• G06F3/039 Primary

  Accessories therefor, e.g. mouse pads · CPC title