Detecting Ambient Light Levels in a Vision System

• US 20110227879A1
• Filed: 06/01/2011
• Published: 09/22/2011
• Est. Priority Date: 10/26/2007
• Status: Abandoned Application

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Masalkar, Prafulla
• Application Number:
  US13/150,416
• Publication Number:
  US 20110227879A1
• Time in Patent Office: Days
• US Class Current: 345/175
• 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

Abstract

The detection of ambient light on an optical touch-sensitive device is disclosed. For example, one disclosed embodiment comprises capturing an image of at least a portion of a display screen with a camera located within the display device, and determined if ambient light in the image is at an acceptable level for display screen operation. Then, a visual representation is displayed representing whether the ambient light level is acceptable for display screen operation.

Claims

1. A method of detecting ambient light in an optical touch-sensitive display device, the optical touch-sensitive display device comprising a display screen, an illuminant and an image sensor, the method comprising:

capturing an image of at least a portion of the display screen with the image sensor;

determining whether an ambient light level in the image is at an acceptable level for optical touch-detection system operation; and

displaying a visual representation of whether the ambient light level is acceptable for display screen optical touch-detection system operation.

2. The method of claim 1, wherein the visual representation of whether the ambient light level is acceptable for optical touch-detection system operation is updated in real-time.

3. The method of claim 1, wherein the visual representation comprises a map of relative ambient light intensities across the display screen.

4. The method of claim 3, wherein the visual representation is color-coded, and wherein a color in the visual representation represents a relative ambient light level.

5. The method of claim 1, further comprising providing a visual indicator of a direction to move the display device to correct for an unacceptable ambient light level.

6. The method of claim 5, wherein a direction to move the display device is determined by determining a plurality of gradients of ambient intensities on the display screen, and generating a directional vector from the gradients.

7-15. -15. (canceled)

16. An optical touch-sensitive device, comprising:

a display screen having a touch surface and a backside;

an image sensor configured to capture an image of the backside of the screen;

an illuminant configured to illuminate the backside of the screen; and

a controller configured to;

operate the illuminant to illuminate the backside of the display screen;

operate the image sensor to capture an image of the display screen;

determine an ambient light level in the image; and

display a visual representation of whether the ambient light level is acceptable for optical touch-detection system operation.

17. The device of claim 16, wherein the visual representation comprises a map of ambient light intensity levels on the display screen.

18. The device of claim 16, wherein the controller is configured to update the visual representation in real-time.

19. The device of claim 16, wherein the visual representation comprises an indicator of a direction to move the display device to reduce the ambient light level.

20. The device of claim 19, wherein the controller is configured to determine the direction to move the display device by determining a plurality of gradients of ambient intensities on the display screen, and determining a directional vector from the gradients.