Optical code reading system and method using a variable resolution imaging sensor

Abstract

An optical code reading system having an auto-exposure system for use with a variable resolution imaging sensor in which very low resolution images are used to determine exposure parameters is presented. The very low resolution images can be transferred much faster than high resolution images which results in a very fast auto-exposure system. The optical code reading system further includes an optical zoom system for zooming in and out of a target without the use of any moveable components. The optical zoom system makes use of a binning and/or subsampling feature of the imaging sensor for zooming in and out of the target. High-speed decoding methodologies are also presented for the optical code reading system. One decoding methodology utilizes low resolution images for performing high-speed decoding. Other methodologies utilize low resolution images and higher resolution images, if the optical code imaged by the low resolution images is not decoded successfully.

1 . An auto-exposure control system for an optical system, said auto-exposure system comprising: 
 a processor for receiving from a variable resolution imaging sensor a low resolution image having at least one characteristic, determining at least one value for the at least one characteristic, associating said at least one value with at least one corresponding exposure-related parameter value, and transmitting at least one auto-exposure control signal for communicating the at least one corresponding exposure-related parameter value, wherein the variable resolution imaging sensor can output images having at least two different resolutions; and    control circuitry for receiving said at least one auto-exposure control signal and controlling at least one exposure-related feature of said optical system in accordance with said at least one corresponding exposure-related parameter value.    
     
     
         2 . The auto-exposure control system according to  claim 1 , wherein the at least one characteristic is selected from the group consisting of light intensity for one pixel of the low resolution image, and a statistical function of a group of pixels of the low resolution image.  
     
     
         3 . The auto-exposure control system according to  claim 1 , wherein the processor accesses at least one data structure for associating the at least one value with the at least one corresponding exposure-related parameter value.  
     
     
         4 . The auto-exposure control system according to  claim 1 , further comprising sensor control circuitry for controlling the imaging sensor for generating the low resolution image.  
     
     
         5 . An optical zoom system for an optical system, said optical zoom system comprising: 
 an imaging sensor having a pixel array and circuitry for combining two or more pixels to form an enlarged pixel; and    a processor for determining a zoom setting from at least two zoom settings and controlling said imaging sensor for outputting an image corresponding to the determined zoom setting, wherein the outputted image is one of an image corresponding to the pixel array of the imaging sensor and an image corresponding to a portion of the pixel array of the imaging sensor, wherein said image corresponding to the portion of the pixel array is comprised of individual pixels or two or more pixels combined to form an enlarged pixel.    
     
     
         6 . The optical zoom system according to  claim 5 , further comprising a range finder system for determining distance information from said imaging sensor to a target.  
     
     
         7 . The optical zoom system according to  claim 6 , further comprising means for communicating the distance information to the processor for use in determining the zoom setting from the at least two zoom settings.  
     
     
         8 . The optical zoom system according to  claim 7 , further comprising a data structure capable of being accessed by said processor for correlating the distance information with one of the at least two zoom settings.  
     
     
         9 . An optical code reading system comprising: 
 an auto-exposure control system comprising: 
 a processor for receiving from an imaging sensor a low resolution image having at least one characteristic, determining at least one value for the at least one characteristic, associating said at least one value with at least one corresponding exposure-related parameter value, and transmitting at least one auto-exposure control signal for communicating the at least one corresponding exposure-related parameter value; and  
 control circuitry for receiving said at least one auto-exposure control signal and controlling at least one exposure-related feature of said optical system in accordance with said at least one corresponding exposure-related parameter value; and  
   an optical zoom system, wherein the imaging sensor has a pixel array and circuitry for combining two or more pixels to form an enlarged pixel, and wherein said processor determines a zoom setting from at least two zoom settings and controls said imaging sensor for outputting an image corresponding to the determined zoom setting, wherein the outputted image is one of an image corresponding to the pixel array of the imaging sensor and an image corresponding to a portion of the pixel array of the imaging sensor, wherein said image corresponding to the portion of the pixel array is comprised of individual pixels or two or more pixels combined to form an enlarged pixel.    
     
     
         10 . The optical code reading system according to  claim 9 , wherein the at least one characteristic is selected from the group consisting of light intensity for one pixel of the low resolution image, and a statistical function of a group of pixels of the low resolution image.  
     
     
         11 . The optical code reading system according to  claim 9 , wherein the processor accesses at least one data structure for associating the at least one value with the at least one corresponding exposure-related parameter value.  
     
     
         12 . The optical code reading system according to  claim 9 , further comprising sensor control circuitry for controlling the imaging sensor for generating the low resolution image.  
     
     
         13 . The optical code reading system according to  claim 9 , further comprising a range finder system for determining distance information from said imaging sensor to a target.  
     
     
         14 . The optical code reading system according to  claim 13 , further comprising means for communicating the distance information to the processor for use in determining the zoom setting from the at least two zoom settings.  
     
     
         15 . The optical code reading system according to  claim 14 , further comprising a data structure capable of being accessed by said processor for correlating the distance information with one of the at least two zoom settings.  
     
     
         16 . The optical code reading system according to  claim 9 , wherein the imaging sensor is a variable resolution imaging sensor capable of outputting images having at least two different resolutions.  
     
     
         17 . An optical code reading system comprising: 
 an imaging sensor capable of generating and outputting images having at least two different resolutions;    means for controlling the imaging sensor for generating and outputting an image having a particular resolution for an optical code; and    means for analyzing the image having the particular resolution.    
     
     
         18 . The optical code reading system according to  claim 17 , wherein the particular resolution is a low resolution.  
     
     
         19 . The optical code reading system according to  claim 17 , further comprising: 
 means for determining whether an image having a higher resolution than the image having the particular resolution should be generated and outputted by said imaging sensor; and    means for controlling the imaging sensor for generating and outputting the image having the higher resolution in accordance with the determination.    
     
     
         20 . A method for decoding an optical code comprising the steps of: 
 providing an imaging sensor capable of generating and outputting images having at least two different resolutions;    controlling the imaging sensor for generating and outputting an image having a particular resolution for the optical code; and    processing the image for decoding the optical code.    
     
     
         21 . The method according to  claim 20 , wherein the particular resolution is a low resolution.  
     
     
         22 . The method according to  claim 20 , further comprising the steps of: 
 if the optical code was not decoded, controlling the imaging sensor for generating and outputting an image having a higher resolution than the image having the particular resolution; and    repeating the method starting from the processing step.    
     
     
         23 . An optical code reading system comprising: 
 an imaging sensor capable of generating and outputting images having at least two different resolutions;    means for controlling the imaging sensor for generating and outputting an image having a low resolution and an image having a high resolution for the optical code;    means for attempting to decode said optical code imaged by the low resolution image;    means for determining whether the optical code imaged by the low resolution image was decoded and attempting to decode said optical code imaged by the high resolution image, if the optical code imaged by the low resolution image was not decoded; and    means for determining whether the optical code imaged by the high resolution image was decoded.    
     
     
         24 . A method for decoding an optical code comprising the steps of: 
 providing an imaging sensor capable of generating and outputting images having at least two different resolutions;    controlling the imaging sensor for generating and outputting an image having a low resolution and an image having a high resolution for the optical code;    attempting to decode said optical code imaged by the low resolution image;    determining whether the optical code imaged by the low resolution image was decoded;    attempting to decode said optical code imaged by the high resolution image, if according to the determining step, the optical code imaged by the low resolution image was not decoded; and    determining whether the optical code imaged by the high resolution image was decoded.    
     
     
         25 . The method according to  claim 24 , further comprising the step of repeating the method starting from the controlling step, if according to the last determining step, the optical code imaged by the high resolution image was not decoded.  
     
     
         26 . The method according to  claim 24 , wherein the step of controlling comprises the steps of: 
 setting a focus position of an optical code reading system to a NEAR position for generating and outputting the image having the low resolution; and    setting the focus position of the optical code reading system to a FAR position for generating and outputting the image having the high resolution.    
     
     
         27 . An optical code reading system comprising: 
 a variable resolution imaging sensor capable of generating images having at least two different resolutions; and    a trigger for actuating an image and decode feature for imaging an optical code with the variable resolution imaging sensor and for decoding said optical code using a decoder.    
     
     
         28 . The optical code reading system according to  claim 27 , further comprising: 
 means for determining an imaging resolution for said variable resolution imaging sensor; and    means for controlling said variable resolution imaging sensor for imaging said optical code according to the determined imaging resolution.    
     
     
         29 . The optical code reading system according to  claim 27 , further comprising: 
 a processor for receiving from said variable resolution imaging sensor a low resolution image having at least one characteristic, determining at least one value for the at least one characteristic, associating said at least one value with at least one corresponding exposure-related parameter value, and transmitting at least one auto-exposure control signal for communicating the at least one corresponding exposure-related parameter value; and    control circuitry for receiving said at least one auto-exposure control signal and controlling at least one exposure-related feature of said optical system in accordance with said at least one corresponding exposure-related parameter value.    
     
     
         30 . The optical code reading system according to  claim 29 , wherein the at least one characteristic is selected from the group consisting of light intensity for one pixel of the low resolution image, and a statistical function of a group of pixels of the low resolution image.  
     
     
         31 . The optical code reading system according to  claim 29 , wherein the processor accesses at least one data structure for associating the at least one value with the at least one corresponding exposure-related parameter value.  
     
     
         32 . The optical code reading system according to  claim 29 , further comprising sensor control circuitry for controlling the variable resolution imaging sensor for generating the low resolution image.  
     
     
         33 . The optical code reading system according to  claim 27 , further comprising an optical zoom system comprising: 
 means for combining two or more pixels of a pixel array of said variable resolution imaging sensor to form an enlarged pixel; and    a processor for determining a zoom setting from at least two zoom settings and controlling said variable resolution imaging sensor for outputting an image corresponding to the determined zoom setting, wherein the outputted image is one of an image corresponding to the pixel array of said variable resolution imaging sensor and an image corresponding to a portion of the pixel array of the variable resolution imaging sensor, wherein said image corresponding to the portion of the pixel array is comprised of individual pixels or two or more pixels combined to form an enlarged pixel.    
     
     
         34 . The optical code reading system according to  claim 27 , further comprising an optical zoom system comprising: 
 means for subsampling at least one pixel from a set of pixels; and    a processor for determining a zoom setting from at least two zoom settings and controlling said imaging sensor for outputting an image corresponding to the determined zoom setting, wherein the outputted image is one of an image corresponding to the pixel array of the imaging sensor and an image corresponding to a portion of the pixel array of the imaging sensor, wherein said image corresponding to the portion of the pixel array is comprised of at least one pixel from the set of pixels.    
     
     
         35 . The optical code reading system according to  claim 33 , further comprising a range finder system for determining distance information from said variable resolution imaging sensor to a target.  
     
     
         36 . The optical code reading system according to  claim 35 , further comprising means for communicating the distance information to the processor for use in determining the zoom setting from the at least two zoom settings.  
     
     
         37 . The optical code reading system according to  claim 35 , further comprising a data structure capable of being accessed by said processor for correlating the distance information with one of the at least two zoom settings.  
     
     
         38 . An optical zoom system for an optical system, said optical zoom system comprising: 
 an imaging sensor having a pixel array and circuitry for subsampling at least one pixel from a set of pixels; and    a processor for determining a zoom setting from at least two zoom settings and controlling said imaging sensor for outputting an image corresponding to the determined zoom setting, wherein the outputted image is one of an image corresponding to the pixel array of the imaging sensor and an image corresponding to a portion of the pixel array of the imaging sensor, wherein said image corresponding to the portion of the pixel array is comprised of at least one pixel from the set of pixels.    
     
     
         39 . An optical code reading system comprising: 
 an auto-exposure control system comprising: 
 a processor for receiving from an imaging sensor a low resolution image having at least one characteristic, determining at least one value for the at least one characteristic, associating said at least one value with at least one corresponding exposure-related parameter value, and transmitting at least one auto-exposure control signal for communicating the at least one corresponding exposure-related parameter value; and  
 control circuitry for receiving said at least one auto-exposure control signal and controlling at least one exposure-related feature of said optical system in accordance with said at least one corresponding exposure-related parameter value; and  
   an optical zoom system, wherein the imaging sensor has a pixel array and circuitry for subsampling at least one pixel from a set of pixels, and wherein said processor determines a zoom setting from at least two zoom settings and controls said imaging sensor for outputting an image corresponding to the determined zoom setting, wherein the outputted image is one of an image corresponding to the pixel array of the imaging sensor and an image corresponding to a portion of the pixel array of the imaging sensor, wherein said image corresponding to the portion of the pixel array is comprised of at least one pixel from the set of pixels.    
     
     
         40 . The optical code reading system according to  claim 39 , wherein the at least one characteristic is selected from the group consisting of light intensity for one pixel of the low resolution image, and a statistical function of a group of pixels of the low resolution image.  
     
     
         41 . The optical code reading system according to  claim 39 , wherein the processor accesses at least one data structure for associating the at least one value with the at least one corresponding exposure-related parameter value.  
     
     
         42 . The optical code reading system according to  claim 39 , further comprising sensor control circuitry for controlling the imaging sensor for generating the low resolution image.  
     
     
         43 . The optical code reading system according to  claim 39 , further comprising a range finder system for determining distance information from said imaging sensor to a target.  
     
     
         44 . The optical code reading system according to  claim 43 , further comprising means for communicating the distance information to the processor for use in determining the zoom setting from the at least two zoom settings.  
     
     
         45 . The optical code reading system according to  claim 44 , further comprising a data structure capable of being accessed by said processor for correlating the distance information with one of the at least two zoom settings.  
     
     
         46 . The optical code reading system according to  claim 39 , wherein the imaging sensor is a variable resolution imaging sensor capable of outputting images having at least two different resolutions.