OPTICAL TOUCH SCREEN SYSTEMS USING WIDE LIGHT BEAMS
A touch screen system, including a screen, a plurality of light sources coupled with the screen, for emitting light, a plurality of photo diodes coupled with the screen, for detecting the light emitted by the light sources, and for identifying the location of a touch on the screen when an absence of the emitted light is detected, and a plurality of lenses coupled respectively with the plurality of light sources to generate wide beams of light over a portion of the screen wherein substantially connected areas of the screen are covered by neighboring wide beams.
1 . A touch screen system, comprising:
a display screen for displaying a plurality of buttons at designated horizontal and vertical screen coordinates thereon;
a plurality of photo diodes coupled with said display screen, for detecting received light; and
a plurality of lenses coupled with said display screen,
wherein the designated horizontal and vertical screen coordinates span a touch sensitive sub-area of said display screen, wherein said photo diodes and lenses are positioned so as to detect a touch of said display screen at the touch sensitive sub-area, and wherein the remainder of said display screen is non-functional for detecting screen coordinates of a touch thereof.
2 . The touch screen system of claim 1 wherein the touch sensitive sub-area comprises less than 25% of the area of said display screen.
3 . The touch screen system of claim 1 wherein the touch sensitive sub-area comprises less than 10% of the area of said display screen.
4 . The touch screen system of claim 1 wherein the touch sensitive sub-area is situated in a corner of said display screen.
5 . The touch screen system of claim 1 wherein said touch sensitive sub-area is surrounded on four sides by portions of the remainder of said display screen.
6 . The touch screen system of claim 1 wherein said display screen is between 6″ and 9″ in length.
7 . The touch screen system of claim 1 wherein said display screen is at least 30″ in length.
8 . The touch screen system of claim 1 wherein said display screen is at least 40″ in length.
9 . The touch screen system of claim 1 wherein said photo diodes are spaced approximately 10 mm apart.
10 . The touch screen system of claim 1 wherein a first coordinate of a touch location is determined based on light detected by at least one of said photo diodes, and a second coordinate of the touch location is determined by correlating the detected light with an activation of at least one of said light sources.
11 . A touch screen system, comprising:
a display screen comprising a touch sensitive sub-area;
a plurality of photo diodes coupled with said display screen, for detecting received light; and
a plurality of lenses coupled with said display screen, wherein said photo diodes and said lenses are positioned so as to detect the position of a touch of said display screen within said touch sensitive sub-area, and wherein the remainder of said display screen is non-functional for detecting the location of a touch thereof.
12 . The touch screen system of claim 11 wherein the touch sensitive sub-area comprises less than 25% of the area of said display screen.
13 . The touch screen system of claim 11 wherein the touch sensitive sub-area comprises less than 10% of the area of said display screen.
14 . The touch screen system of claim 11 wherein the touch sensitive sub-area is situated in a corner of said display screen.
15 . The touch screen system of claim 11 wherein said touch sensitive sub-area is surrounded on four sides by portions of the remainder of said display screen.
16 . The touch screen system of claim 11 wherein said lenses are operative to focus wide beams of light onto said photo diodes, the touch screen further comprising a processor connected to said photo diodes for calculating a position of a pen tip that touches said display screen within one of the wide beams.
17 . The touch screen system of claim 16 wherein said processor calculates the position of the pen tip based upon a light intensity detected by at least one of said photo diodes.
18 . The touch screen system of claim 16 wherein said processor calculates the position of the pen tip along one axis based upon light intensities detected by the photo diodes along a single axis.
19 . The touch screen system of claim 11 wherein said display screen is between 6″ and 9″ in length.
20 . The touch screen system of claim 11 wherein said display screen is at least 30″ in length.
21 . The touch screen system of claim 11 wherein said display screen is at least 40″ in length.
22 . The touch screen system of claim 11 wherein said photo diodes are spaced approximately 10 mm apart.
23 . The touch screen system of claim 11 wherein a first coordinate of a touch location is determined based on light detected by at least one of said photo diodes, and a second coordinate of the touch location is determined by correlating the detected light with an activation of at least one of said light sources.
24 . A touch screen system, comprising:
a screen;
a plurality of light sources coupled with said screen, for emitting light;
a plurality of photo diodes coupled with said screen, for detecting the light emitted by said light sources, and for identifying the location of a touch on said screen when an absence of the emitted light is detected; and
a plurality of lenses coupled respectively with said plurality of light sources to generate wide beams of light over a portion of said screen wherein substantially connected areas of said screen are covered by neighboring wide beams.
25 . The touch screen system of claim 24 further comprising a second plurality of lenses coupled respectively with said plurality of photo diodes to narrow the wide beams onto said photo diodes.
26 . The touch screen system of claim 25 wherein said second lenses are placed at least 4 mm away from respective ones of said photo diodes.
27 . The touch screen system of claim 26 wherein said photo diodes and said second lenses are placed adjacent to an edge of said screen.
28 . The touch screen system of claim 26 wherein said light sources are placed under said screen and said second lenses are placed adjacent to an edge of said screen.
29 . The touch screen system of claim 24 wherein a first set of the wide beams span the length of said screen and a second set of the wide beams span the width of said screen, wherein an overlap between the first and second sets defines a touch-sensitive sub-area of said screen, and wherein the remainder of said screen is non-functional for detecting the location of a touch thereon.
30 . The touch screen system of claim 29 wherein the touch sensitive sub-area is situated in a corner of said screen.
31 . The touch screen system of claim 29 wherein the touch sensitive sub-area is surrounded on four sides by portions of the remainder of said screen.
32 . The touch screen system of claim 24 further comprising a processor connected to said photo diodes for calculating a location of a pen tip that touches said screen within one of the wide beams.
33 . The touch screen system of claim 22 wherein said processor calculates the location of the pen tip based upon a light intensity detected by at least one of said photo diodes.
34 . The touch screen system of claim 22 wherein said processor calculates the location of the pen tip along one axis based upon light intensities detected by said photo diodes along a single axis.
35 . The touch screen system of claim 24 wherein said screen is between 6″ and 9″ in length.
36 . The touch screen system of claim 24 wherein said screen is at least 30″ in length.
37 . The touch screen system of claim 24 wherein said screen is at least 40″ in length.
38 . The touch screen system of claim 24 wherein said photo diodes are spaced approximately 10 mm apart.
39 . The touch screen system of claim 24 wherein a first coordinate of a touch location is determined based on light detected by at least one of said photo diodes, and a second coordinate of the touch location is determined by correlating the detected light with an activation of at least one of said light sources.
40 . The touch screen system of claim 24 wherein said lenses are placed at least 4 mm way from respective ones of said light sources.
41 . The touch screen system of claim 40 wherein said light sources are placed under said screen and said first lenses are placed adjacent to an edge of said screen.
42 . The touch screen system of claim 40 wherein said light sources and said first lenses are placed adjacent to an edge of said screen.