Optical reader having a plurality of imaging modules

Abstract

The invention is an optical reader having a plurality of imaging modules. In one method for operating a multiple imaging module reader of the invention, a second frame of image data captured via actuation of a second imaging module is automatically captured and subjected to decoding in the case an attempt to decode using a frame of image data captured via actuation of a first imaging module fails. In another embodiment, a frame of image data captured via actuation of an image sensor of a first module and actuation of illumination of a second imaging module is subjected to decoding. In another embodiment, frames of image data captured via actuation of image sensors of spaced apart modules are combined. The various modules of a multiple imaging module reader can be adapted to have different best focus positions so that a field depth of the reader is improved.

What is claimed:  
     
         1 . An optical reader comprising: 
 a housing defining at least one cavity;    a first imaging module mounted in said at least one cavity;    a second imaging module mounted in said at least one cavity; 
 wherein each of said first and second modules includes an image sensor, a support assembly, and at least one illumination LED;  
   a control circuit in communication with each of said first and second imaging modules; 
 wherein said control circuit is programmed, in response to receipt of a trigger signal, to: 
 (a) capture a first frame of image data via actuation of said at least one illumination LED and said image sensor of said first imaging module;  
 (b) determine whether said first frame of image data includes decodable indicia;  
 (c) automatically subject to a decode attempt a second frame of image data if said determination step (b) indicates that decodable indicia is not or is likely not represented in said first frame of image data, wherein said second frame of image data is captured via actuation of said at least one LED and said image sensor of said second imaging module.  
 
   
     
     
         2 . The reader of  claim 1 , wherein said control circuit in determining whether decodable indicia is represented in said first frame of image data attempts to decode decodable indicia represented in said first frame of image data.  
     
     
         3 . The reader of  claim 1 , wherein said control circuit  140  captures said second frame of image data contemporaneously while capturing said first frame of image data.  
     
     
         4 . The reader of  claim 1 , wherein said control circuit in determining whether decodable indicia is represented in said first frame of image data preliminarily evaluates image data of said first frame without attempting to decode decodable indicia represented therein.  
     
     
         5 . The reader of  claim 4 , wherein said control circuit in preliminarily evaluating said image data evaluates said image data to determine whether a saturation condition is present.  
     
     
         6 . The reader of  claim 1 , wherein said first imaging module is a 1D imaging module and wherein said second imaging module is a 2D imaging module.  
     
     
         7 . The reader of  claim 1 , wherein said first and second imaging modules are configured to have first and second best focus distances, wherein said first best focus distance is at least 1 inch apart from said second best focus distance.  
     
     
         8 . The reader of  claim 1 , wherein said trigger signal is an automatically generated trigger signal generated by decodable indicia being moved in a field of view of said reader.  
     
     
         9 . The reader of  claim 1 , further comprising a trigger, wherein said trigger signal is generated when said trigger is pulled.  
     
     
         10 . An optical reader comprising: 
 a housing defining at least one cavity;    a first imaging module mounted in said at least one cavity,    a second imaging module mounted in said at least one cavity; 
 wherein each of said first and second modules includes an image sensor, a support assembly, and at least one illumination LED;  
   a control circuit in communication with each of said first and second imaging modules; 
 wherein said control circuit is programmed, in response to receipt of a trigger signal to: 
 (a) capture a first frame of image data via actuation of said illumination LED and said image sensor of said first imaging module;  
 (b) determine whether said first frame of image data includes decodable indicia;  
 (c) automatically subject to a decode attempt a second frame of image data if said determination step (b) indicates that decodable indicia is not or is likely not represented in said first frame, wherein said second frame of image data is captured via actuation of said at least one LED of said second imaging module and said image sensor of said first imaging module, wherein no illumination LED of said first imaging module is actuated when said second frame of image data is captured.  
 
   
     
     
         11 . The reader of  claim 10 , wherein said control circuit in determining whether decodable indicia is represented in said first frame of image data attempts to decode decodable indicia represented in said first frame of image data.  
     
     
         12 . The reader of  claim 10 , wherein said control circuit captures said second frame of image data contemporaneously while capturing said first frame of image data.  
     
     
         13 . The reader of  claim 10 , wherein said control circuit in determining whether decodable indicia is represented in said first frame of image data preliminarily evaluates image data of said first frame without attempting to decode decodable indicia represented therein.  
     
     
         14 . The reader of  claim 13 , wherein said control circuit in preliminarily evaluating said image data evaluates said image data to determine whether a saturation condition is present.  
     
     
         15 . The reader of  claim 10 , wherein said first imaging module is a 1D imaging module and wherein said second imaging module is a 2D imaging module.  
     
     
         16 . The reader of  claim 10 , wherein said first and second imaging modules are configured to have first and second best focus distances, wherein said first best focus distance is at least 1 inch apart from said second best focus distance.  
     
     
         17 . The reader of  claim 10 , wherein said trigger signal is an automatically generated trigger signal generated by decodable indicia being moved in a field of view of said reader.  
     
     
         18 . The reader of  claim 10 , further comprising a trigger, wherein said trigger signal is generated when said trigger is pulled.  
     
     
         19 . An optical reader comprising: 
 a housing defining a cavity;    a first imaging module mounted in said cavity;    a second imaging module mounted in said cavity; 
 wherein each of said first and second imaging modules includes an image sensor, a support assembly, and at least one illumination LED;  
   a control circuit in communication with each of said first and second imaging modules; 
 wherein said control circuit is programmed, in response to receipt of a trigger signal, to: 
 (a) capture a first and second frame of image data, wherein said first frame of image data is captured via actuation of said at least one LED and said image sensor of said first imaging module, and said second frame of image data is captured via actuation of said at least one LED and said image sensor of said second imaging module;  
 (b) determine whether said first and second frames include decodable indicia;  
 (c) automatically combine said first frame and said second frame to generate a third image representation if said determination step (b) indicates that decodable indicia is not or is likely not represented in said first and second frames of image data; and to  
 (d) subject said third image representation to a decode attempt.  
 
   
     
     
         20 . The reader of  claim 19 , wherein said control circuit in determining whether decodable indicia is represented in said first and second frames of image data attempts to decode decodable indicia represented in said first and second frames of image data.  
     
     
         21 . The reader of  claim 19 , wherein said control circuit captures said second frame of image data contemporaneously while capturing said first frame of image data.  
     
     
         22 . The reader of  claim 19 , wherein said control circuit in determining whether decodable indicia is represented in said first and second frames of image data preliminarily evaluates image data of said first and second frames of image data without attempting to decode decodable indicia represented therein.  
     
     
         23 . The reader of  claim 22 , wherein said control circuit in preliminarily evaluating said image data evaluates gray scale pixel values of said image data to determine whether a saturation condition is present.  
     
     
         24 . The reader of  claim 19 , wherein said control circuit in combining said first and second frames of image data determines an area of overlap between said first and second frames of image data.  
     
     
         25 . The reader of  claim 19 , wherein said control circuit in combining said first and second frames of image data generates a signal indicative of a module-to-target distance of at least one of said modules.  
     
     
         26 . The reader of  claim 19 , wherein said control circuit in combining said first and second frames of image data combines said first and second frames in a manner dependent on an angle between imaging axes of said first and second imaging modules.  
     
     
         27 . The reader of  claim 19 , wherein said control circuit in combining said first and second frames of image data identifies a common graphical element commonly represented in said first and second frames of image data.  
     
     
         28 . The reader of  claim 19 , wherein said first and second imaging modules are configured to have first and second best focus distances, wherein said first best focus distance is at least 1 inch apart from said second best focus distance.  
     
     
         29 . The reader of  claim 19 , wherein said trigger signal is an automatically generated trigger signal generated by decodable indicia being moved in a field of view of said reader.  
     
     
         30 . The reader of  claim 19 , further comprising a trigger, wherein said trigger signal is generated when said trigger is pulled.