Calibration of an interactive display system
First Claim
1. A method for calibrating and compensating at least one error in an interactive display system that includes a projector for projecting images on a display surface as defined by a software program, a light source for illuminating an object on the display surface with light, and a vision sensing system having an imaging sensor for receiving light reflected back from the display surface by an object in contact with the display surface, said method including the steps of:
- (a) receiving a signal from the imaging sensor, said signal varying in response to an intensity of the light reflected from an object in contact with the display surface;
(b) automatically compensating the signal received from the imaging sensor for the at least one error on the image produced by the imaging sensor, yielding a compensated signal;
(c) aligning at least one of the vision sensing system and the projector relative to the other and to the display surface; and
(d) employing the compensated signal as an input to the software program that defines the images projected on the display surface, so that the software program accurately detects a location of an object on the display surface relative to the images projected on the display surface by the projector.
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Accused Products
Abstract
In an interactive display system, a projected image on a display surface and a vision system used to detect objects touching the display surface are aligned, and optical distortion of the vision system is compensated. Also, calibration procedures correct for a non-uniformity of infrared (IR) illumination of the display surface by IR light sources and establish a touch threshold for one or more uses so that the interactive display system correctly responds to each user touching the display surface. A movable IR camera filter enables automation of the alignment of the projected image and the image of the display surface and help in detecting problems in either the projector or vision system.
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Citations
48 Claims
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1. A method for calibrating and compensating at least one error in an interactive display system that includes a projector for projecting images on a display surface as defined by a software program, a light source for illuminating an object on the display surface with light, and a vision sensing system having an imaging sensor for receiving light reflected back from the display surface by an object in contact with the display surface, said method including the steps of:
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(a) receiving a signal from the imaging sensor, said signal varying in response to an intensity of the light reflected from an object in contact with the display surface;
(b) automatically compensating the signal received from the imaging sensor for the at least one error on the image produced by the imaging sensor, yielding a compensated signal;
(c) aligning at least one of the vision sensing system and the projector relative to the other and to the display surface; and
(d) employing the compensated signal as an input to the software program that defines the images projected on the display surface, so that the software program accurately detects a location of an object on the display surface relative to the images projected on the display surface by the projector. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. An interactive display system, comprising:
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(a) a display surface on which images are displayed and on which objects are detected;
(b) a light source for illuminating an object on the display surface with light;
(c) a vision sensing system having an imaging sensor for sensing a object in contact with the display surface by sensing the light reflected back from the object;
(d) a projector for projecting images on the display surface;
(e) a processor coupled to the projector and the vision sensing system; and
(f) a memory storing machine instructions including a software application and procedures for calibrating and compensating said at least one error in the interactive display system, by carrying out a plurality of functions, including;
(i) receiving a signal from the imaging sensor, said signal varying in response to an intensity of the light reflected from an object in contact with the display surface;
(ii) automatically compensating the signal received from the imaging sensor for the at least one error on the image produced by the imaging sensor, yielding a compensated signal;
(iii) facilitating alignment of at least one of the vision sensing system and the projector relative to the other and to the display surface; and
(iv) employing the compensated signal as an input to the software program that defines images projected on the display surface, so that the software program accurately detects a location of an object on the display surface relative to the images projected on the display surface by the projector. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
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30. A method for calibrating a touch threshold for an interactive display system that responds to users touching a display surface on which images are projected by sensing light reflected from where the user touches the display surface, comprising the steps of:
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(a) detecting a likely touch of a region on the display surface by a user, based upon criteria related to an image of the display surface that indicate the user has touched the region;
(b) detecting an intensity of reflected light for points in the image within the region where it is determined that the user likely touched the display surface; and
(c) setting the touch threshold equal to the intensity of the points within the region where it is determined that the user likely touched the display surface. - View Dependent Claims (31, 32, 33, 34, 35, 36, 37, 38, 39)
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40. An interactive display system in which provision is made for calibrating a touch threshold, comprising:
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(a) a display surface on which images are displayed and on which objects are detected;
(b) a light source for illuminating an object on the display surface with light;
(c) a vision sensing system having an imaging sensor for sensing a object in contact with the display surface by sensing the light reflected back from the object;
(d) a projector for projecting images on the display surface;
(e) a processor coupled to the projector and the vision sensing system; and
(f) a memory storing machine instructions for carrying out a plurality of functions, including;
(i) detecting a likely touch of a region on the display surface by a user, based upon criteria related to an image of the display surface made by the imaging sensor that indicate the user has touched the region;
(ii) detecting an intensity of reflected light for points in the image within the region where it is determined that the user likely touched the display surface; and
(iii) setting the touch threshold equal to the intensity of the points within the region where it is determined that the user likely touched the display surface. - View Dependent Claims (41, 42, 43, 44, 45, 46, 47, 48)
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Specification