Touch-sensitive button with two levels

Abstract

A touch-sensitive depressible button with multiple depression thresholds is provided. When the button is depressed to a first depression threshold, the touch sensor can be switched from a low-power, non-sensing state to a sensing state. When the button is depressed to a second depression threshold, the touch sensor can sense the touch context and input can be generated based on the depression and the touch context. In this way, the touch-sensitive depressible button with multiple depression thresholds can facilitate timely switching of the touch sensor to a sensing state.

What is claimed is: 
     
         1 . A touch sensing system, comprising:
 a touch sensor array for detecting one or more touches;   a force sensing mechanism coupled with the touch sensor array; and   a controller communicatively coupled to the touch sensor array and the force sensing mechanism, the controller configured for
 placing the touch sensor array in non-sensing state when no touch is detected by the force sensing mechanism, 
 switching the touch sensor array from the non-sensing state to a sensing state when a touch is detected by the force sensing mechanism, and 
 receiving touch input from the touch sensor array after the touch sensor array has been switched to the sensing state, the touch input capturing an image of the touch on the touch sensor array. 
   
     
     
         2 . The touch sensing system of  claim 1 , wherein the force sensing mechanism is a mechanical force sensing actuator. 
     
     
         3 . The touch sensing system of  claim 1 , wherein the force sensing mechanism is a self-capacitance force sensing actuator. 
     
     
         4 . The touch sensing system of  claim 1 , the controller further configured for:
 placing the touch sensor array in low power state when no touch is detected by the force sensing mechanism;   switching the touch sensor array from the low power state to an active scan state when the touch is detected by the force sensing mechanism.   
     
     
         5 . The touch sensing system of  claim 1 , the force sensing mechanism configured for detecting a touch when a pressure threshold is exceeded. 
     
     
         6 . The touch sensing system of  claim 1 , the controller further configured for identifying a touch object based on the touch input. 
     
     
         7 . The touch sensing system of  claim 1 , the controller further configured for scanning the touch sensor array to detect one or more touches of one or more objects when the touch sensor array is switched to the sensing state. 
     
     
         8 . The touch sensing system of  claim 7 , the controller further configured for performing a series of scans of the touch sensor array to detect one or more positions of the one or more touches. 
     
     
         9 . The touch sensing system of  claim 1 , the controller further configured for detecting a shape of the one or more touches. 
     
     
         10 . The touch sensing system of  claim 1 , incorporated within a portable computing device. 
     
     
         11 . A method for capturing an image of touch from a touch sensor array and a force sensing mechanism, comprising:
 placing the touch sensor array in a non-sensing state when no touch is detected by the force sensing mechanism;   switching the touch sensor array from the non-sensing state to a sensing state when a touch is detected by the force sensing mechanism; and   receiving touch input from the touch sensor array after the touch sensor array has been switched to the sensing state, the touch input capturing the image of the touch on the touch sensor array.   
     
     
         12 . The method of  claim 11 , further comprising detecting the touch using a mechanical force sensing actuator. 
     
     
         13 . The method of  claim 11 , further comprising detecting the touch using a self-capacitance force sensing actuator. 
     
     
         14 . The method of  claim 11 , further comprising:
 placing the touch sensor array in low power state when no touch is detected by the force sensing mechanism;   switching the touch sensor array from the low power state to an active scan state when the touch is detected by the force sensing mechanism.   
     
     
         15 . The method of  claim 11 , further comprising detecting a touch when a pressure threshold is exceeded. 
     
     
         16 . The method of  claim 11 , further comprising identifying a touch object based on the touch input. 
     
     
         17 . The method of  claim 11 , further comprising scanning the touch sensor array to detect one or more touches of one or more objects when the touch sensor array is switched to the sensing state. 
     
     
         18 . The method of  claim 17 , further comprising performing a series of scans of the touch sensor array to detect one or more positions of the one or more touches. 
     
     
         19 . The method of  claim 11 , further comprising detecting a shape of the one or more touches. 
     
     
         20 . A touch sensing system, comprising:
 means for placing a touch sensor array in a non-sensing state when no touch is detected by a force sensing mechanism;   means for switching the touch sensor array from the non-sensing state to a sensing state when a touch is detected by the force sensing mechanism; and   means for receiving touch input from the touch sensor array after the touch sensor array has been switched to the sensing state, the touch input capturing the image of the touch on the touch sensor array.