Characterization of a scan line produced from a facet of a scanning device

Abstract

A method for refining a length of a scan line, where the scan line is produced from a facet of a scanning device. The method comprises the steps of: (a) acquiring a plurality of scan line lengths produced from the facet, (b) determining from the plurality of scan line lengths, an average scan line length for the facet, and (c) determining from the average scan line length, a scan line length correction for the facet. A method for measuring a length of a scan line comprises the steps of: (a) charging an electrical current integrator to a voltage while a scan line is produced from a facet, (b) measuring the voltage, and (c) determining from the voltage, the length of the scan line produced from the facet.

What is claimed is:  
     
         1 . A method for refining a length of a scan line, wherein said scan line is produced from a facet of a scanning device, comprising the steps of: 
 (a) acquiring a plurality of scan line lengths produced from a facet;    (b) determining from said plurality of scan line lengths, an average scan line length for said facet; and    (c) determining from said average scan line length, a scan line length correction for said facet.    
     
     
         2 . The method of  claim 1 , wherein said facet is one of a plurality of facets on a rotating reflector, and wherein said method further comprises the step of obtaining a number from a cyclic counter to identify said facet and to associate said plurality of scan line lengths with said facet when determining said average scan line length.  
     
     
         3 . The method of  claim 1 , wherein said scanning device produces pixels at a dot imaging frequency, and wherein said plurality of scan line lengths is acquired from a counter that is clocked at a rate of less than 8 times said dot imaging frequency.  
     
     
         4 . A system for refining a length of a scan line, wherein said scan line is produced from a facet of a scanning device, comprising: 
 (a) means for acquiring a plurality of scan line lengths produced from a facet;    (b) means for determining from said plurality of scan line lengths, an average scan line length for said facet; and    (c) means for determining from said average scan line length, a scan line length correction for said facet.    
     
     
         5 . The system of  claim 4 , wherein said facet is one of a plurality of facets on a rotating reflector, and wherein said system further comprises a cyclic counter for providing a number for said facet to identify said facet and to associate said plurality of scan line lengths with said facet when determining said average scan line length.  
     
     
         6 . The system of  claim 4 , wherein said scanning device produces pixels at a dot imaging frequency, and wherein said acquiring means comprises a counter that is clocked at a rate of less than 8 times said dot imaging frequency.  
     
     
         7 . A storage medium that includes instructions for controlling a processor to execute a method for refining a length of a scan line, wherein said scan line is produced from a facet of a scanning device, said storage medium comprising: 
 (a) first instructions for controlling said processor to acquire a plurality of scan line lengths produced from a facet;    (b) second instructions for controlling said processor to determine from said plurality of scan line lengths, an average scan line length for said facet; and    (c) third instructions for controlling said processor to determine from said average scan line length, a scan line length correction for said facet.    
     
     
         8 . The storage medium of  claim 7 , wherein said facet is one of a plurality of facets on a rotating reflector, and wherein said storage medium comprises further instructions for controlling said processor to obtain a number from a cyclic counter to identify said facet and to associate said plurality of scan line lengths with said facet when determining said average scan line length.  
     
     
         9 . The storage medium of  claim 7 , wherein said scanning device produces pixels at a dot imaging frequency, and wherein said scan line length is acquired from a counter that is clocked at a rate of less than 8 times said dot imaging frequency.  
     
     
         10 . A method for measuring a length of a scan line, wherein said scan line is produced from a facet of a scanning device, comprising the steps of: 
 (a) charging an electrical current integrator to a voltage while a scan line is produced from a facet;    (b) measuring said voltage; and    (c) determining from said voltage, a length of said scan line.    
     
     
         11 . The method of  claim 10 , further comprising the step of determining from said length, a scan line length correction for said facet.  
     
     
         12 . The method of  claim 10 , wherein said facet is one of a plurality of facets on a rotating reflector, and wherein said method further comprises the step of obtaining a number from a cyclic counter to identify said facet and to associate said length of said scan line with said facet.  
     
     
         13 . The method of  claim 10 , further comprising before said charging step, the step of resetting said electrical current integrator in response to a receipt of a reference signal that indicates a start of said scan line produced from said facet.  
     
     
         14 . The method of  claim 13 , wherein said resetting step is delayed by a predetermined interval of time from said receipt of said reference signal.  
     
     
         15 . The method of  claim 10 , wherein said measuring step samples said voltage in response to a receipt of a reference signal that indicates an end of said scan line produced from said facet.  
     
     
         16 . The method of  claim 10 , wherein said measuring step samples said voltage in response to a receipt of a reference signal that indicates a start of a scan line produced by a next facet.  
     
     
         17 . A system for measuring a length of a scan line, wherein said scan line is produced from a facet of a scanning device, comprising: 
 (a) means for charging an electrical current integrator to a voltage while a scan line is produced from a facet;    (b) means for measuring said voltage; and    (c) means for determining from said voltage, a length of said scan line.    
     
     
         18 . The system of  claim 17 , further comprising means for determining from said length, a scan line length correction for said facet.  
     
     
         19 . The system of  claim 17 , wherein said facet is one of a plurality of facets on a rotating reflector, and wherein said system further comprises a cyclic counter for providing a number for said facet to identify said facet and to associate said length of said scan line with said facet.  
     
     
         20 . The system of  claim 17 , further comprising means for resetting said electrical current integrator in response to a receipt of a reference signal that indicates a start of said scan line produced from said facet.  
     
     
         21 . The system of  claim 20 , wherein said resetting means performs its respective action after a delay of a predetermined interval of time from said receipt of said reference signal.  
     
     
         22 . The system of  claim 17 , wherein said measuring means samples said voltage in response to a receipt of a reference signal that indicates an end of said scan line produced from said facet.  
     
     
         23 . The system of  claim 17 , wherein said measuring means samples said voltage in response to a receipt of a reference signal that indicates a start of a scan line produced by a next facet.  
     
     
         24 . A storage medium that includes instructions for controlling a processor to execute a method for measuring a length of a scan line, wherein said scan line is produced from a facet of a scanning device, comprising the steps of: 
 (a) first instructions for controlling said processor to charge an electrical current integrator to a voltage while a scan line is produced from a facet;    (b) second instructions for controlling said processor to measure said voltage; and    (c) third instructions for controlling said processor to determine from said voltage, a length of said scan line.    
     
     
         25 . The storage medium of  claim 24 , comprising further instructions for controlling said processor to determine from said length of said scan line, a scan line length correction for said facet.  
     
     
         26 . The storage medium of  claim 24 , wherein said facet is one of a plurality of facets on a rotating reflector, and wherein said storage medium comprises further instructions for controlling said processor to obtain a number from a cyclic counter to identify said facet and to associate said length of said scan line with said facet.  
     
     
         27 . The storage medium of  claim 24 , comprising further instructions for controlling said processor to reset said electrical current integrator in response to a receipt of a reference signal that indicates a start of said scan line produced from said facet.  
     
     
         28 . The storage medium of  claim 27 , wherein said instructions for controlling said processor to reset said electrical current integrator performs its respective action after a delay of a predetermined interval of time from said receipt of said reference signal.  
     
     
         29 . The storage medium of  claim 24 , comprising further instructions for controlling said processor to sample said voltage in response to a receipt of a reference signal that indicates an end of said scan line produced from said facet.  
     
     
         30 . The storage medium of  claim 24 , comprising further instructions for controlling said processor to sample said voltage in response to a receipt of a reference signal that indicates a start of a scan line produced by a next facet.