Temperature compensation and noise avoidance for resonator pen

Abstract

Methods and devices are disclosed for characterizing user inputs. A first input object may be detected in a sensing region of an input device. A resonance frequency of the first input object may be determined. A first characteristic may be assigned to the first input object based at least in part on the resonance frequency of the first input object. User inputs provided by the first input object may be processed based at least in part on the first input object characteristic.

What is claimed is: 
     
         1 . A method for adjusting a frequency band associated with a first input object, comprising:
 detecting first user input provided by a first input object in a sensing region of an input device;   identifying a first frequency associated with the first input object;   determining that a threshold condition is met for adjusting the first frequency; and   in response to determining that the threshold condition is met, adjusting the first frequency associated with the first input object.   
     
     
         2 . The method of  claim 1 , wherein the threshold condition is met when a first frequency response of the first input object at the first frequency is less than a threshold frequency response. 
     
     
         3 . The method of  claim 2 , wherein adjusting the first frequency comprises reducing the first frequency. 
     
     
         4 . The method of  claim 3 , wherein adjusting the first frequency comprises reducing the first frequency by a fixed amount. 
     
     
         5 . The method of  claim 2 , wherein the threshold frequency is equal to zero. 
     
     
         6 . The method of  claim 2 , wherein the threshold frequency is greater than zero. 
     
     
         7 . The method of  claim 1 , wherein identifying the first frequency comprises:
 determining two or more frequency responses of the first input object, wherein the two or more frequency responses include at least a frequency response at a second frequency and a frequency response at a third frequency; and   determining the largest frequency response of the two or more frequency responses of the first input object, the first frequency being identified based on the largest of the two or more frequency responses.   
     
     
         8 . The method of  claim 1 , wherein the first frequency is adjusted in a direction of a peak frequency response of the first input object. 
     
     
         9 . The method of  claim 1 , wherein the adjusting of the first frequency comprises:
 scanning a range of frequencies extending above and below the first frequency; and   selecting an optimum frequency within the range of frequencies to be the adjusted first frequency.   
     
     
         10 . The method of  claim 9 , wherein the highest frequency in the range of scanned frequencies is 7% higher than the first frequency and the lowest frequency in the range of scanned frequencies is 7% lower than the first frequency. 
     
     
         11 . The method of  claim 9 , wherein the determining of the optimum frequency comprises:
 determining a respective frequency response of the input object at each of the frequencies in the range of scanned frequencies, the optimum frequency being the frequency associated with the largest of the determined frequency responses.   
     
     
         12 . The method of  claim 9 , wherein the determining of the optimum frequency comprises:
 determining a respective frequency response of the input object at each of the frequencies in the range of scanned frequencies, the optimum frequency being less than the frequency associated with the largest of the determined frequency responses.   
     
     
         13 . An input device, comprising:
 one or more processors;   a touch-sensitive sensing region; and   a memory, storing one or more programs comprising instructions that, when executed by the one or more processors, cause the input device to perform operations comprising:
 detecting first user input provided by a first input object in a sensing region of an input device; 
 identifying a first frequency associated with the first input object; 
 determining that a threshold condition is met for adjusting the first frequency; and 
 in response to determining that the threshold condition is met, adjusting the first frequency associated with the first input object. 
   
     
     
         14 . The input device of  claim 13 , wherein the threshold condition is met when a first frequency response of the first input object at the first frequency is less than a threshold frequency response. 
     
     
         15 . The input device of  claim 14 , wherein execution of the instructions for adjusting the first frequency causes the input device to perform operations further comprising reducing the first frequency. 
     
     
         16 . The input device of  claim 15 , wherein execution of the instructions for adjusting the first frequency causes the input device to perform operations further comprising reducing the first frequency by a fixed amount. 
     
     
         17 . The input device of  claim 14 , wherein the threshold frequency is equal to zero. 
     
     
         18 . The input device of  claim 14 , wherein the threshold frequency is greater than zero. 
     
     
         19 . The input device of  claim 13 , wherein execution of the instructions for identifying the first frequency causes the input device to perform operations further comprising:
 determining two or more frequency responses of the first input object, wherein the two or more frequency responses include at least a frequency response at a second frequency and a frequency response at a third frequency; and   determining the largest frequency response of the two or more frequency responses of the first input object, the first frequency being identified based on the largest of the two or more frequency responses.   
     
     
         20 . A non-transitory computer-readable storage medium storing instructions that, when executed by processing circuitry of an input device, cause the input device to perform operations comprising:
 detecting first user input provided by a first input object in a sensing region of an input device;   identifying a first frequency associated with the first input object;   determining that a threshold condition is met for adjusting the first frequency; and   in response to determining that the threshold condition is met, adjusting the first frequency associated with the first input object.