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Method and system for increasing the effective dynamic range of a photosensor
   
Document Number
US Patent 4967066
Issued Date
October 30, 1990
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Abstract
In active range finder apparatus wherein an object to be inspected is illuminated by a laser source and light reflected by the object is detected in an imaging photosensor, a system is provided for increasing the dynamic range of the apparatus. This system provides for integrating over each of a series of measuring time periods light reflected from a window of the photosensor and hence proportional to the light received by such photosensor. When such integrated light exceeds a predetermined amount, a saturation signal is generated that immediately de-energizes the source. If this amount is not reached by the end of each period, the system is reset. The source is gradually re-energized at the commencement of each subsequent period. The virtually instantaneous de-energization and gradual re-energization combined with use of a saturation detector separate from the main photosensor ensures rapid action that is quick enough to substantially avoid saturation of such main photosensor.
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Method and system for increasing the effective dynamic range of a photosensor - US Patent 4967066 Drawing
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Number of Claims:
7
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Published
October 30, 1990
Application Number
07/417,492
Filed
October 5, 1989
US Classification
250/205   250/214R
Int'l Classification
G01S   7/491   (20060101)   G01S   7/48   (20060101)  
Examiner
Assistant Examiner
Priority Data
Oct 19, 1988 [CA] 580652
USPTO Field of Search
250/205   250/214R   315/152   315/156   315/157   315/158  
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Description
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