Interactive touch-screen using infrared illuminators
First Claim
1. A touch-screen system, comprising:
- a computing system;
a translucent screen;
a plurality of illuminators that project in a particular range of frequencies, wherein the plurality of illuminators are configured such that an object touching the translucent screen casts a plurality of shadows, each shadow corresponding to an illuminator of the plurality of illuminators; and
a camera sensitive to the particular range of frequencies to which the plurality of illuminators is sensitive;
wherein a first image captured by the camera is employed by the computing system to determine where the object touches the translucent screen based upon the locations of the plurality of shadows in the first image.
0 Assignments
0 Petitions
Accused Products
Abstract
Provided is a touch-screen system that employs infrared illuminators and detectors to determine where an object or person touches a translucent screen. A visual image is projected onto the translucent screen by means of a projector placed on the back side of the screen opposite the user. Infrared illuminators are placed on the front side of the translucent screen at oblique angles to the screen. When a user touches the screen each of the infrared illuminators is shadowed from the screen to a certain degree, depending upon the shape of the object placed upon the screen. By determining where on the screen the shadows cast by the object or person overlap, a computing device calculates where the object or person is touching the screen In an alternative embodiment, controlled ambient light rather than infrared illuminators is employed. Also provided is a calibration method for the system.
44 Citations
24 Claims
-
1. A touch-screen system, comprising:
-
a computing system;
a translucent screen;
a plurality of illuminators that project in a particular range of frequencies, wherein the plurality of illuminators are configured such that an object touching the translucent screen casts a plurality of shadows, each shadow corresponding to an illuminator of the plurality of illuminators; and
a camera sensitive to the particular range of frequencies to which the plurality of illuminators is sensitive;
wherein a first image captured by the camera is employed by the computing system to determine where the object touches the translucent screen based upon the locations of the plurality of shadows in the first image. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A touch-screen system, comprising:
-
a computing system;
a translucent screen;
a barrier, opaque to ambient light and positioned such that ambient light strikes the translucent screen only at oblique angles; and
a camera sensitive to a range of frequencies associated with the ambient light;
wherein a first image captured by the camera is employed by the computing system to determine where an object touches the translucent screen based upon a plurality of shadows cast by the object in conjunction with the ambient light. - View Dependent Claims (11, 12, 13, 14, 15)
-
-
16. A method of calculating coordinates of an area of contact on a touch-screen, comprising the steps of:
-
illuminating a translucent screen such that an object that touches the translucent screen cast one or more shadows on the translucent screen;
detecting the one or more shadows to create a first image of the translucent screen; and
calculating an area of contact upon the translucent screen corresponding to where the object touches the translucent screen based upon the first image. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23)
-
-
24. A method of calibrating a touch-screen, comprising the steps of:
-
projecting onto a translucent screen a series of registration spots, each of the registration spots projected to a known coordinate on the translucent screen;
capturing a series of images of the translucent screen, each image corresponding to one spot of the series of projected spots;
calculating a coordinate in each image of the series of images corresponding to the corresponding projected spot;
correlating the known coordinate of each of the registration images to the calculated coordinate to create a coordinate pair; and
saving the coordinate pairs corresponding to each spot.
-
Specification