Method and Apparatus For Configurable Photodetector Array Patterning For Optical Encoders

Abstract

An encoder device includes an array of detectors that are operable to detect a flux and to generate currents in response to the detection; multiple current lines for conducting currents; a set of switches coupled between the array of detectors and the multiple current lines such that an output of each of the array of detectors is routed to none or one of the multiple current lines; and a controller operable to configure the set of switches.

What is claimed is: 
     
         1 . An encoder device, comprising:
 an array of detectors that are operable to detect a flux and to generate currents in response to the detection;   multiple current lines for conducting currents;   a set of switches coupled between the array of detectors and the multiple current lines such that an output of each of the array of detectors is routed to none or one of the multiple current lines; and   a controller operable to configure the set of switches.   
     
     
         2 . The encoder device of  claim 1 , wherein the multiple current lines include four lines. 
     
     
         3 . The encoder device of  claim 1 , wherein the array of detectors has non-homogeneous shapes. 
     
     
         4 . The encoder device of  claim 1 , wherein some detectors of the array of detectors are of a rectangular shape, a round shape, an elliptical shape, or a shape having rounded corners. 
     
     
         5 . The encoder device of  claim 1 , further comprising a first memory that is operable to store first data for configuring the set of switches, wherein the controller is operable to access the first data from the first memory. 
     
     
         6 . The encoder device of  claim 5 , further comprising a second memory that is operable to store second data for configuring the set of switches, wherein the controller is operable to access the first data from the first memory and to access the second data from the second memory. 
     
     
         7 . The encoder device of  claim 1 , wherein some of the array of detectors are operable to be turned off or partially on during operations of the encoder device. 
     
     
         8 . The encoder device of  claim 1 , further comprising multiple transimpedance amplifiers coupled to the multiple current lines. 
     
     
         9 . The encoder device of  claim 8 , wherein each of the multiple transimpedance amplifiers includes an adjustable current sink additive to its input. 
     
     
         10 . An encoder apparatus, comprising:
 an array of photodetectors that are operable to generate currents in response to detection of light incident thereon;   multiple current lines for conducting currents;   a set of switches coupled between outputs of the array of photodetectors and the multiple current lines;   a memory operable to store data; and   a controller operable to access the data from the memory and configure the set of switches according to the data such that an output of each of the array of photodetectors is connected to no more than one of the multiple current lines at a time.   
     
     
         11 . The encoder apparatus of  claim 10 , further comprising an emitter operable to generate the light. 
     
     
         12 . The encoder apparatus of  claim 10 , further comprising a motion object that is operable to modulate the light before the light is detected by the array of photodetectors. 
     
     
         13 . The encoder apparatus of  claim 10 , wherein some of the array of photodetectors are operable to be turned off or partially on during operations of the encoder apparatus. 
     
     
         14 . The encoder apparatus of  claim 10 , wherein the array of photodetectors includes photodetectors of different sizes or of different shapes. 
     
     
         15 . A method, comprising:
 collecting first characteristics of a motion object;   collecting second characteristics of a configurable detector array that includes an array of detectors;   determining a partition map that defines quadrature states for the array of detectors based on the first and the second characteristics; and   storing the partition map into a non-volatile memory.   
     
     
         16 . The method of  claim 15 , wherein the motion object is a code wheel and the first characteristics include radii, pulse per resolution, or rotation speed of the code wheel. 
     
     
         17 . The method of  claim 15 , wherein the second characteristics include dimensions of the array of detectors, detector spacing, detector shape, detector size, X-direction misalignment between the array of detectors and the motion object, or Y-direction misalignment between the array of detectors and the motion object. 
     
     
         18 . The method of  claim 15 , further comprising:
 retrieving the partition map from the non-volatile memory;   configuring the configurable detector array according to the partition map; and   performing a detection of movement of the motion object.   
     
     
         19 . The method of  claim 18 , further comprising:
 from the detection of movement of the motion object, generating data about misalignment between the motion object and the configurable detector array.   
     
     
         20 . The method of  claim 19 , further comprising:
 computing another partition map based on the data about the misalignment.