Ambient correction in rolling image capture system
First Claim
1. An optical touch-sensitive device, comprising:
- a screen;
a rolling image capture system configured to acquire an image of the screen, the rolling image capture system comprising one or more fields of pixels;
a local light source configured to illuminate the screen with local light; and
a controller in electrical communication with the rolling image capture system and the local light source, wherein the controller is configured to;
acquire a first frame of image data with the rolling image capture system;
acquire a second frame of image data with the rolling image capture system;
while acquiring the first frame of image data and the second frame of image data, operate the local light source such that each field of pixels integrates local+ambient light for a duration tlocal+ambient and ambient light for a duration tambient, and such that a sum tlocal+ambient+tambient for the first frame of image data is different than a sum tlocal+ambient+tambient for the second frame of image data for each field of pixels;
determine an ambient light value for a pixel in the image data from one or more of the first frame of image data and the second frame of image data; and
adjust one or more pixels for ambient light based upon the ambient light value.
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Accused Products
Abstract
Embodiments are disclosed that relate to the correction of an image acquired in a rolling image capture system for ambient light. One embodiment provides a device comprising a screen, a rolling image capture system, a local light source, and a controller. The controller is configured to operate the local light source while acquiring first and second frames of image data to integrate each field of image sensor pixels for a duration of local+ambient light and for a duration of ambient light such that a sum tlocal+ambient+tambient for the first frame is different than a sum tlocal+ambient+tambient for the second frame for each field of pixels. The controller is further configured to determine an ambient light value, and to adjust one or more pixels based upon the ambient light value.
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Citations
20 Claims
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1. An optical touch-sensitive device, comprising:
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a screen; a rolling image capture system configured to acquire an image of the screen, the rolling image capture system comprising one or more fields of pixels; a local light source configured to illuminate the screen with local light; and a controller in electrical communication with the rolling image capture system and the local light source, wherein the controller is configured to; acquire a first frame of image data with the rolling image capture system; acquire a second frame of image data with the rolling image capture system; while acquiring the first frame of image data and the second frame of image data, operate the local light source such that each field of pixels integrates local+ambient light for a duration tlocal+ambient and ambient light for a duration tambient, and such that a sum tlocal+ambient+tambient for the first frame of image data is different than a sum tlocal+ambient+tambient for the second frame of image data for each field of pixels; determine an ambient light value for a pixel in the image data from one or more of the first frame of image data and the second frame of image data; and adjust one or more pixels for ambient light based upon the ambient light value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. An optical touch-sensitive device, comprising:
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a screen; a rolling image capture system configured to acquire an image of the screen, the rolling image capture system comprising one or more fields of pixels; a rolling local light source configured to provide local lighting in a spatially rolling pattern synchronized with the rolling image capture system; and a controller in electrical communication with the rolling image capture system and the rolling local light source, wherein the controller is configured to; acquire a first frame of image data with the rolling image capture system; acquire a second frame of image data with the rolling image capture system; while acquiring the first frame of image data and the second frame of image data, operate the rolling local light source such that each field of rolling image capture system pixels integrates local+ambient light for a duration tlocal+ambient and ambient light for a duration tambient, and such that a sum tlocal+ambient+tambient for the first frame of image data is different than a sum tlocal+ambient+tambient for the second frame of image data for each field of pixels; determine an ambient light value for a pixel in the image data from one or more of the first frame of image data and the second frame of image data; and adjust one or more pixels of the data frame for ambient light based upon the ambient light value. - View Dependent Claims (14, 15, 16, 17)
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18. A method of correcting for ambient light in an optical touch-sensitive device comprising a screen, a rolling image capture system comprising a first field of pixels and a second field of pixels, a rolling local light source configured to provide local lighting in a spatially rolling pattern synchronized with the rolling image capture system, and a controller in electrical communication with the rolling image capture system and the rolling local light source, the method comprising:
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acquiring a first frame of image data by progressively reading the first field of pixels while illuminating the screen with the rolling local light source and then progressively reading the second field of pixels while not illuminating the screen with the rolling local light source; and after acquiring the first frame of image data, acquiring a second frame of image data by progressively reading the second field of pixels while illuminating the screen with the rolling local light source and then progressively reading the first field of pixels while not illuminating the screen with the rolling local light source; determining an ambient light value for a selected pixel from one or more of the first frame of image data and the second frame of image data; and adjusting one or more pixels of image data for ambient light based upon the ambient light value. - View Dependent Claims (19, 20)
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Specification