Capacitive gesture detection system and methods thereof

Abstract

Apparatus and methods are disclosed related to managing characteristics of a mobile device based upon capacitive detection of materials proximate the mobile device, a capacitive gesture system that can allow the same gestures be used in arbitrary locations within range of a mobile device. One such method includes receiving a first capacitive sensor measurement with a first capacitive sensor of the mobile device. The method further includes determining a value indicative of a material adjacent to the mobile device based on a correspondence between the first capacitive sensor measurement and stored values corresponding to different materials. The method further includes sending instructions to adjust a characteristic of the mobile device based on the determined value indicative of the material adjacent to the mobile device. In certain examples, gesture sensing can be performed using capacitive measurements from the capacitive sensors.

What is claimed is: 
     
         1 . A method for controlling transmitted electromagnetic power on a hand-held device using environmental capacitive sensing, the steps comprising:
 measuring a dielectric constant of an object proximate to the hand-held device using a first and second capacitive sensor;   receiving data from the first and second capacitive sensors;   determining the material of the object based on the dielectric constant;   developing a spatial profile of the object based upon the electrostatic charge distribution represented in the received data;   calculating the imposed impedance produced from the proximity and material of the object; and,   compensating the transmitted electromagnetic power based on the imposed impedance.   
     
     
         2 . The method of  claim 1  further comprising the step of altering the transmitted electromagnetic power distribution using a phased antenna array disposed in the hand-held device. 
     
     
         3 . The method of  claim 2  further comprising the step distributing transmitted electromagnetic power distribution such that the electromagnetic radiation is directed substantially away from the object. 
     
     
         4 . The method of  claim 1  further comprising executing a single-ended capacitance measurement using the first capacitive sensor. 
     
     
         5 . The method of  claim 4  further comprising executing a single-ended capacitance measurement using the second capacitive sensor. 
     
     
         6 . The method of  claim 5  further comprising executing a differential capacitance measurement using the first and second capacitive sensor. 
     
     
         7 . The method of  claim 6  further comprising the step of utilizing the sum of the single-ended capacitance measurements of the first and second capacitive sensors and the differential capacitance measurement assist in the development of the spatial profile. 
     
     
         8 . The method of  claim 6  further comprising the step of utilizing the sum of the single-ended capacitance measurements of the first and second capacitive sensors and the differential capacitance measurement assist in the determination of the object material. 
     
     
         9 . The method of  claim 6  further comprising the step of connecting the first capacitive sensor to a positive input of a differential amplifier front-end to an analog-to-digital converter and the second capacitive sensor to a negative input of the differential amplifier front-end, or vice versa, to obtain the differential capacitance measurement between the first capacitive sensor and the second capacitive sensor. 
     
     
         10 . The method of  claim 1  further comprising the step of measuring a conductivity of the object proximate to the hand-held device using a ground plane antenna disposed in the hand-held device. 
     
     
         11 . The method of  claim 1  further comprising the step of accessing a multi-dimensional lookup table stored on a memory using the capacitance measurements. 
     
     
         12 . The method of  claim 1  further comprising the step of applying a pre-determined algorithm stored on a memory to the capacitance measurements. 
     
     
         13 . A non-transitory computer-readable medium comprising code that, when executed by a processor, causes an apparatus to:
 receive capacitance measurements measured by at least two capacitive sensors of the hand-held device, including: (1) a left capacitive sensor configured to provide capacitance measurements related to a first portion of a hand adjacent to the left side of hand-held device and (2) a right capacitive sensor configured to provide capacitance measurements related to a second portion of the hand adjacent to the right side of hand-held device; and   determine a type of grip of the hand on the hand-held device based on the capacitance measurements, wherein the capacitance measurements include a differential capacitance measurement between the left capacitive sensor and the right capacitive sensor, a single-ended capacitance measurement of the left capacitive sensor, and a single-ended capacitance measurement of the right capacitive sensor; and   access a two-dimensional lookup table, wherein accessing the two-dimensional lookup table comprises:
 looking up a magnitude of the differential capacitance measurement between the left capacitive sensor and the right capacitive sensor; and 
 looking up the sum of (1) the single-ended capacitance measurement of the left capacitive sensor, and (2) the single-ended capacitance measurement of the right capacitive sensor, 
   wherein the intersection of the two-indexed look-ups includes information indicating the type of grip, and   wherein the type of grip specifies placements of the palm, digits, and thumb on the hand-held device in a particular configuration.   
     
     
         14 . The medium of  claim 13 , wherein:
 determining the type of grip of the hand comprises accessing a multi-dimensional lookup table stored on a memory using the capacitance measurements.   
     
     
         15 . A system for detecting dynamic motion proximate to a hand-held device using environmental capacitive sensing, the system comprising:
 means for measuring a dielectric constant of an object proximate to the hand-held device using a first and second capacitive sensor;   means for receiving data from the first and second capacitive sensors;   means for determining the material of the object based on the dielectric constant;   means for developing a dynamic spatial profile of the object based upon a plurality of electrostatic charge distributions represented in the received data over a predetermine time period;   means for receiving data from one or more accelerometers disposed in the hand-held device; and,   means for interpreting the dynamic spatial profile as object motion relative to hand-held device in view of data received from one or more accelerometers.   
     
     
         16 . The system of  claim 15  further comprising a means for executing a single-ended capacitance measurement using the first capacitive sensor. 
     
     
         17 . The system of  claim 15  further comprising a means for executing a single-ended capacitance measurement using the second capacitive sensor. 
     
     
         18 . The system of  claim 17  further comprising a means for executing a differential capacitance measurement using the first and second capacitive sensor. 
     
     
         19 . The system of  claim 18  further comprising a means for utilizing the sum of the single-ended capacitance measurements of the first and second capacitive sensors and the differential capacitance measurement assist in the development of the dynamic spatial profile. 
     
     
         20 . The system of  claim 19  further comprising a means for of utilizing the sum of the single-ended capacitance measurements of the first and second capacitive sensors and the differential capacitance measurement assist in the determination of the object material.