Measuring Capacitance

Abstract

An apparatus may include an input surface, a plurality of key positions on the input surface, a force sensor positioned underneath the input surface at at least one of the key positions, and a proximity controller in communication with a capacitance measuring circuit incorporated into the apparatus.

1 . An apparatus, including:
 an input surface;   a force sensor positioned underneath the input surface; and   the force sensor including:
 a piezoelectric material, 
 a first electrically conductive material located on a first side of the piezoelectric material; 
 a second electrically conductive material located on a second side, opposite of the first side, of the piezoelectric material; 
 the first electrically conductive material and the second electrically conductive material are each in communication with a proximity controller, which is programmed to measure the capacitance between the first electrically conductive material and the second electrically conductive material; 
 the force sensor being configured to:
 detect a user input on and/or near the input surface based on the capacitance measurement from between first electrically conductive material portion and the second electrically conductive material of the piezoelectric sensor. 
 
   
     
     
         2 . The apparatus of  claim 1 , wherein the input surface is a screen. 
     
     
         3 . The apparatus of  claim 2 , wherein the input surface is made of a foldable material. 
     
     
         4 . The apparatus of  claim 2 , further comprising:
 a processor;   memory in communication with the processor;   programmed instructions stored in the memory that, when executed, cause the processor to:
 send a haptic feedback signal to the force sensor in response to a user input on and/or near the input surface. 
   
     
     
         5 . The apparatus of  claim 4 , wherein the programmed instructions, when executed, cause the processor to:
 detect the user input pressing the input surface based on input from the proximity controller.   
     
     
         6 . The apparatus of  claim 4 , wherein the programmed instructions, when executed, cause the processor to:
 detect hand gestures based on input from the proximity controller.   
     
     
         7 . The apparatus of  claim 4 , wherein the programmed instructions, when executed, cause the processor to:
 detect the user input pressing the input surface based on input from the force controller.   
     
     
         8 . The apparatus of  claim 4 , wherein the proximity circuit and a force circuit of the force sensor are both in communication with an integrated circuit. 
     
     
         9 . The apparatus of  claim 1 , wherein the force sensor includes:
 wherein the first electrically conductive material is connected to a transmit electrode in communication with the proximity controller; and   wherein the second electrically conductive material is connected to a sense electrode in communication with the proximity controller.   
     
     
         10 . The apparatus of  claim 1 , wherein the input surface is a roll up or a foldable surface. 
     
     
         11 . The apparatus of  claim 1 , wherein the input surface is made of a continuous material. 
     
     
         12 . A method for measuring proximity, including:
 measuring capacitance between a first electronically conductive portion of a force sensor and a second electronically conductive portion of the force sensor.   
     
     
         13 . The method of  claim 12 , wherein the force sensor includes an active material responsive to pressure;
 wherein the first portion is a first electrically conductive layer adjacent a first side of the active material;   wherein the second portion is a second electrically conductive layer adjacent a second side, opposite of the first side, of the active material.   
     
     
         14 . The method of  claim 13 , wherein the active material is selected from the group of piezoelectric materials, magnetostrictive materials, or combinations thereof. 
     
     
         15 . The method of  claim 12 , wherein the first portion of the force sensor and the second portion of the force sensor are in communication with a proximity controller. 
     
     
         16 . The method of  claim 12 , wherein the force sensor is incorporated into an input device, the input device comprising:
 an input surface;   a plurality of key positions on the input surface;   the force sensor positioned underneath the input surface at at least one of the key positions; and   a proximity controller in communication with force sensor.   
     
     
         17 . The method of  claim 16 , further comprising:
 detecting a user input pressing the at least one key position based on input from the proximity controller.   
     
     
         18 . The method of  claim 16 , further comprising:
 detecting hand gestures based on input from the proximity controller.   
     
     
         19 . The method of  claim 16 , further comprising:
 detecting a user input pressing on the at least one key position based on the capacitance measurement from between portions of the force sensor without relative movement between the input surface and the at least one key position.   
     
     
         20 . A computer-program product for controlling a computing device, the computer-program product comprising a non-transitory computer-readable medium storing instructions executable by a processor to:
 measure capacitance in an input device where the capacitance is measured between a first electrically conductive material located on a first side of a piezoelectric and/or magnetostrictive sensor and a second electrically conductive material located on a second side, opposite of the first side, of the piezoelectric and/or magnetostrictive sensor;   detect a user input on and/or near a surface of the input device based on the measured capacitance from between portions of the piezoelectric and/or magnetostrictive sensor.