Integrated pressure sensitive lens assembly
A touch screen assembly for an electronic device such as a cell phone or PDA. The touch screen assembly generally comprises a floating lens suspended over the display and, optionally, the keypad to allow a degree of freedom. An underlying thin connecting layer such as a flex film is attached beneath the floating lens, and a plurality (for example, four) differentially-mounted pressure sensors are mounted beneath the floating lens and are electrically connected to the electronic device via the flex film. The pressure sensors are differentially positioned along an x- and y-axis for registering a pressure z from a touch to the lens at each of the four positions, to provide four data sets (x 1-4 , y 1-4 , z 1-4 ). Control software then interprets the exact touch-coordinate from the four data sets and generates a control signal. An optional haptic response generator and/or motion sensor are also contemplated. When used in a smaller electronics device such as a cell phone or PDA the touch screen sensor technology of the present invention is exceedingly thin and is capable of modular assembly for more-or-less “snap-in” construction.
1. A touch screen assembly for an electronic device having an LCD or OLED display module, comprising:
a lens over said display module;
a plurality n=1 . . . m of differentially-mounted pressure sensors mounted beneath said display module and differentially positioned along an x- and y-axis, said pressure sensors being electrically connected to the electronic device for registering a pressure z from a touch of said lens at any position along said x- and y-axis and for providing an analog differential pressure signal z over a duration of said touch of said lens;
a circuit for converting said analog differential pressure signal into a time-based sequence of digital data sets (x 1-m , y 1-m , z 1-m ) each data set comprising a sequence of data points x, y, z for each of said plurality n=1. . . m of differentially-mounted pressure sensors measured at successive time instants during the duration of said touch of said lens; and
control software for filtering said time-based sequence of data sets (x 1-m , y 1-m , z 1-m ) by removing non-relevant data points x, y, z from said time-based sequence, and for interpreting the filtered data set as an exact touch-coordinate x, y and pressure z resulting from a touch of said lens along said x- and y-axis, and for generating a control signal in accordance with said filtered and interpreted touch coordinate.
2. The touch screen assembly for an electronic device according to claim 1 , wherein said differentially-mounted pressure sensors further comprises Force Sensing Resistor (FSR) sensors.
3. The touch screen assembly for an electronic device according to claim 2 , wherein said differentially-mounted FSR sensors include four FSR sensors.
4. The touch screen assembly for an electronic device according to claim 1 , further comprising a haptic response generator coupled to said lens for generating a vibration burst when a pressure is registered against said lens.
5. The touch screen assembly for an electronic device according to claim 1 , wherein said lens is a floating lens over said display module.
6. The touch screen assembly for an electronic device according to claim 5 , wherein said floating lens extends over a keypad of said device.
7. The touch screen assembly for an electronic device according to claim 1 , wherein said pressure sensors each comprise a piezo resistive force sensor mounted orthogonally from the lens.
8. The touch screen assembly for an electronic device according to claim 1 , wherein said control software filters successive data sets to remove non-relevant input.
9. The touch screen assembly for an electronic device according to claim 1 , further comprising a motion sensor connected through said connection layer for responding to position, orientation and movement.
10. The touch screen assembly for an electronic device according to claim 1 , wherein said control software is resident in a host processor of said electronic device.
11. The touch screen assembly for an electronic device according to claim 5 , wherein said electronic device comprises a housing with an aperture and said floating lens comprises a tongue and groove periphery for engaging said electronic device housing and allowing a downward degree of freedom.
12. A touch screen assembly for an electronic device having a display, comprising:
a floating lens suspended over said display to allow a degree of freedom.
an underlying flex film connection layer attached beneath at least a portion of said floating lens;
four differentially-mounted pressure sensors mounted beneath said floating lens and differentially positioned along an x- and y-axis, said pressure sensors being electrically connected to the electronic device via said connection layer for registering a pressure z from a touch of said lens at each of said four positions over a duration of said touch of said lens;
a circuit for converting said pressure z from a touch of said lens at each of said four positions into a time-based sequence of digital data sets (x 1-4 , y 1-4 , z 1-4 ), each data set comprising a sequence of data points x, y, z for each of said four differentially-mounted pressure sensors measured at successive time instants during the duration of said touch of said lens; and
control software for filtering said time-based sequence of data sets by removing non-relevant data points x, y, z from said time-based sequence and interpreting said filtered data sets (x 1-4 , y 1-4 , z 1-4 ) as a single data set x, y, z) representative of a touch coordinate and for generating a control signal in accordance with said touch coordinate.
13. The touch screen assembly for an electronic device according to claim 12 , further comprising a haptic response generator coupled to said lens for generating a vibration burst when a pressure is registered against said lens.
14. The touch screen assembly for an electronic device according to claim 12 , wherein said floating lens extends over both of said display and keypad.
15. The touch screen assembly for an electronic device according to claim 12 , wherein said pressure sensors each comprise an Force Sensing Resistor (FSR) sensor.
16. The touch screen assembly for an electronic device according to claim 12 , wherein said pressure sensors each comprise a mechanical component and transducer mounted orthogonally from the transparent lens.
17. The touch screen assembly for an electronic device according to claim 12 , wherein said floating lens assembly is spring loaded.
18. The touch screen assembly for an electronic device according to claim 12 , wherein said software component records a number of data points over time during each key press.
19. A touch screen assembly for an electronic device having an LCD or OLED display module, comprising:
a lens over said display module;
a plurality n=1. . . m of pressure sensors mounted below said lens and differentially positioned along an x- and y-axis, each of said pressure sensors being compressed with a preload force p 1 . . . m and electrically connected to the electronic device for registering a pressure Pc i-m from a touch of said lens at any position along said x- and y-axis and for providing an analog differential pressure signal over a duration of said touch of said lens;
a circuit for converting said analog differential pressure signal into a time-based sequence of data sets (x 1-m , y 1-m , z 1-m ), each data set comprising a sequence of data points x, y, z for each of said plurality n=1. . .m of differentially-mounted pressure sensors measured at successive time instants during the duration of said touch of said lens; and
control software for compensating said time-based sequence of data sets (x i-m , y i-m , z i-m ) by adjusting data points z 1-m within said time-based sequence in accordance with a formula Pc1 . . . m =z 1-m −Pc 1-m , and for interpreting said modified time-based data sets (x i-m ,y i-m , p ci-m , as a sin le non-time-based data set x, y, z) resentative of a touch coordinate to provide an exact touch-coordinate and for generating a control signal in accordance with said touch coordinate.
20. The touch screen assembly for an electronic device according to claim 19 , wherein said differentially-mounted pressure sensors further comprise four Force Sensing Resistor (FSR) sensors.
21. The touch screen assembly for an electronic device according to claim 19 , further comprising a haptic response generator coupled to said lens for generating a vibration burst when a pressure is registered against said lens.
22. The touch screen assembly for an electronic device according to claim 21 , wherein said pressure sensors each comprise a piezo resistive force sensor mounted orthogonally from the lens.