Object identification using an optical scanner

Abstract

A method to discriminate between multiple types of objects presented to a scanner is discussed. The method includes illuminating an object in a scan using a light source, performing multiple analog to digital conversions of light magnitude reflected off the object producing a multitude of digital values and processing the digital values using changes in the digital values and the light source position. One embodiment is a system which identifies blood sample vials a for blood testing. The system includes an optical scanner producing an analog output of a scan of a blood sample vial, a digitizer sampling the analog output to produce digitized scan data, a data processor interpreting the digitized data providing vial type identification information to the blood tester. The scanner used may also incorporate a barcode scanner to read barcodes affixed to the blood sample vials.

We claim:  
     
         1 . A method for determining characteristics of an object, comprising: 
 scanning an object with an optical source to produce an analog reflected light signal, the scanned object residing forward of a background reflective enough to produce contrast between the scanned object and the background that is discernable in a digitized version of the analog reflected light signal;    sampling the analog reflected light signal to obtain a sampled reflection signal;    converting the sampled reflection signal into a series of digital values; and    processing the digital values to determine the characteristics of the scanned object.    
     
     
         2 . The method of  claim 1 , wherein the characteristics include one or more of the group consisting of position, width, height, shape, contents, and attachments of the object.  
     
     
         3 . The method of  claim 1 , wherein the processing comprises searching for magnitude changes in sequential digital values to indicate the presence of an edge of the object.  
     
     
         4 . The method of  claim 3 , wherein the processing further comprises distinctly detecting object edges corresponding to optical source illumination scanning from the reflective background onto the object and from the object and onto the reflective background.  
     
     
         5 . The method of  claim 1 , wherein the optical source is light from a barcode scanner.  
     
     
         6 . A method for discriminating between types of objects presented to a scanner, comprising: 
 illuminating at least a portion of an object during a scan with a light source in the scanner    sampling light reflected from the object during the scan to obtain a first sampled reflected light signal;    performing at least two analog to digital conversions of the first sampled reflected light signal to produce at least two digital values; and    determining an object type by processing the at least two digital values using knowledge of light source position relative to the scanned object.    
     
     
         7 . The method of  claim 6 , wherein the object is located in an object carrier, and the method further comprises: 
 illuminating at least a portion of the object carrier during the scan with the light source; and    sampling light reflected from the object carrier during the scan to obtain a second sampled reflected light signal indicating the presence of the object carrier.    
     
     
         8 . The method of  claim 7 , wherein the multiple objects are medical sample vials.  
     
     
         9 . The method of  claim 8 , wherein each medical sample vial is associated with a barcode which is read by the scanner.  
     
     
         10 . The method of  claim 6 , wherein the at least one portion comprises the top of an object.  
     
     
         11 . The method of  claim 6 , wherein the processing comprises: 
 arithmetically manipulating the at least two digital values to determine if a change of shape has occurred along a path of the scan.    
     
     
         12 . The method of  claim 6 , wherein the type of object includes one or more of the group consisting of position, width, height, shape, contents, and attachments of the object.  
     
     
         13 . The method of  claim 6 , wherein the scanner is a bar code scanner with a reflected light analog output.  
     
     
         14 . The method of  claim 6 , further comprising: 
 repeating the illuminating, sampling, performing, and determining steps to determine the width of the object.    
     
     
         15 . The method of  claim 6 , wherein the processing step includes determining the height of the object.  
     
     
         16 . The method of  claim 6 , wherein the objects are medial sample vials, and the determining step includes determining if the objects have one or more of the group consisting of a tapered top, a cap, the absence of a cap, and an insert.  
     
     
         17 . A system for identifying objects, comprising: 
 an optical scanner for illuminating with light an object residing forward of a reflective background during a scan;    a digitizer for receiving and sampling an analog reflected light signal produced by the illumination of the object during the scan; and    a data processor that determines a type for the object by discerning changes in magnitude of sequential portions of the digitized data output by the digitizer indicative of an edge of the object.    
     
     
         18 . The system of  claim 17 , wherein the optical scanner also acts as a barcode scanner.  
     
     
         19 . The system of  claim 17 , wherein the digitizer comprises a progressively corrected scan signal circuit allowing the digitized data to accurately represent the magnitude of the analog reflected light signal independent of any spectral reflectance received from the reflective background during the scan.  
     
     
         20 . The system of  claim 19 , wherein the background is a highly reflective background.  
     
     
         21 . The system of  claim 17 , wherein the object edges are discerned from the portion of the digitized data indicative of when the light from the optical scanner transitions from the reflective background to the object and from the object to the reflective background.  
     
     
         22 . The system of  claim 17 , wherein the object type includes an object size and an object shape.  
     
     
         23 . The system of  claim 17 , further comprising a barcode reader associated with the optical scanner, the barcode reader extracting information contained in a barcode associated with the object.  
     
     
         24 . The system of  claim 17 , wherein the object resides in an object carrier.  
     
     
         25 . The system of  claim 24 , wherein the data processor also detects the presence of the object carrier analyzing the changes in magnitude of sequential portions of the digitized data output by the digitizer.  
     
     
         26 . The system of  claim 17 , wherein the object is a blood sample vial.  
     
     
         27 . The system of  claim 25 , wherein the blood sample vial resides in a carrier.