Abstract:
A bar code scanner is disclosed, which is arranged to operate in both a first mode, and a second mode. In said first mode a limited number of bar code symbologies or types are read, as part of the scanning process. In said second mode, at least, one additional bar code symbology is read, as part of the scanning process.

Description:
The present invention relates generally to bar code scanners and, more specifically, to scanning bar codes. 
   BACKGROUND OF THE INVENTION 
   Conventional bar codes have varying width bars and spaces suitably printed on a label. The bar code may take any conventional form in one or more dimensions, and includes, for example, the typical one-dimensional UPC form. The UPC symbology is based on a specification enacted by the Uniform Product Code Council, Inc. of Dayton Ohio. The typical UPC bar code includes a series or sequence of alternating dark bars and light spaces of varying widths. The bars and spaces are arranged in groups representing individual characters. The bar code starts with a left margin character and ends with a right margin character, and has a center reference character as well, with the characters provided there between representing any desired data. 
   The minimum width of either a bar or space in the UPC symbology is defined as a single module, which represents a unit width. The width of a single character coded using the UPC symbology is seven (7) modules. A seven module UPC character has two bar and two space elements which have varying widths to differentiate between the respective characters. 
   There are many types of bar code symbologies (encoding schemes). For example, there are a number of different one-dimensional bar code symbologies. These symbologies include UPC/EAN, Code 39, Code 128, Codabar and Interleaved 2 of 5. There are also 2 dimensional bar code symbologies. 
   Generally, bar code scanners are programmed to read only the bar code types that are currently being used in the system. This is done to increase decoding accuracy and allow the bar code scanner the maximum processing power to decode the bar codes that do exist in the system. 
   Occasionally, a new type of bar code is introduced into the system, such as, Interleaved 2 of 5, or some other bar code symbology. The scanner operator or scanner service personnel may not have the capability to discern the bar code symbology and other, significant details of the new bar code. Therefore, the operator or service personnel lack the ability to program the scanner to read this new bar code type. Accordingly, this can result in delays at checkouts as a more experienced operator or engineer may be required to program the scanner, before the new bar code in question can be read. 
   It is an object of the present invention to provide a bar code scanner, which can be utilized by an untrained operator to scan regularly used bar codes and those which are new or are infrequently used by a system. 
   It is a further object of the present invention to enable the introduction of new types of bar code into a bar code system when the operator does not know the details of the bar code, such as the bar code symbology or type, or bar code length, etc. 
   It is yet a further object of the present invention to produce a bar code scanner, which obviates the problems discussed above. 
   SUMMARY OF THE INVENTION 
   According to a first aspect of the present invention there is provided a bar code scanner arranged to operate in both a first mode, in which a limited number of bar code symbologies or types are read, as part of the scanning process, and a second mode, in which, at least, one additional bar code symbology is read, as part of the scanning process. 
   According to a second aspect of the present invention there is provided a method of scanning a bar code utilizing both a first mode, in which a limited number of bar code symbologies or types are read, as part of the scanning process, and a second mode, in which, at least, one additional bar code symbology is read, as part of the scanning process. 
   The invention, in accordance with preferred and exemplary embodiments, together with further objects and advantages thereof, is more particularly described in the following detailed description taken in conjunction with the accompanying drawing. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a schematic representation of a bar code and scanner in accordance with the present invention. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Illustrated schematically in  FIG. 1  is a laser bar code scanner  10  for scanning and decoding a conventional bar code  12  printed on a suitable label  14 . The bar code  12  may take any conventional form in one or more dimensions including the conventional one-dimensional UPC symbology illustrated. The exemplary bar code  12  illustrated in  FIG. 1  includes a plurality of sequential or alternating dark bars  12   a  and white spaces  12   b , which are straight and parallel to each other and have corresponding varying widths W.sub.b and W.sub.s. The bars and spaces are arranged in a plurality of sequential groups defining respective characters of equal width. The minimum width of a bar or a space is defined as the minimum width module, and in the UPC symbology must exceed 8 mils by specification. A single UPC character is defined as having two bars  12   a  and two spaces  12   b  of varying widths. And, the specified widths of a single character coded using the UPC symbology must, by specification, be seven modules. Furthermore, the UPC symbology defines the maximum bar width as being four modules. 
   In the exemplary bar code  12  illustrated in  FIG. 1 , the bar code conventionally starts with a left margin character  12   c , ends with a right margin character  12   d , and has a center reference character  12   d , with the remaining bars and spaces there between defining desired data characters. As indicated above, each of the data characters has a total width of seven modules and includes two bars and two spaces. 
   The exemplary scanner  10  illustrated in  FIG. 1  includes conventional means for optically scanning the bar code  12  sequentially across the bars and spaces  12   a,b  over the total width of the bar code  12  from the left margin character  12   c  to the right margin character  12   d . In the preferred embodiment illustrated, scanning is accomplished by using a conventional laser  16  which emits a suitable laser beam  16   a  which is suitably scanned across the face of the bar code  12  by a conventional sweep generator  18  which may take the form of a rotating multifaceted mirror. The laser beam  16   a  is scanned transversely across the bar code  12  in a scan direction S so that back scattered light  16   b  reflects off the bars and spaces back to the scanner. Since the bars  12   a  are dark, very little light is back scattered therefrom, whereas the spaces  12   b  are substantially white and more effectively back scatter light to the scanner. 
   A conventional photodetector  20  is provided in the scanner  10  and is suitably optically aligned therein for receiving the back scattered light  16   b  and producing an electrical bar code signature  20   s  alternating in intensity between maximum and minimum values corresponding with the back scattered light  16   b  from the spaces  12   b  and bars  12   a , respectively. The time duration of the maximum and minimum intensity portions of the signature  20   s  corresponds with the varying widths of the bars and spaces. Since the scan beam  16   a  is scanned across the bar code  12  at a known and constant rate of speed, the bar code signature  20   s  is representative of the bar code  12  itself and may be decoded in a conventional decoder  22  specifically configured for the corresponding bar code symbology printed on the label  14 . 
   The decoder  22  may take any conventional form and is typically a digitally programmable microprocessor containing suitable software for analyzing the bar code signature  20   s  and decoding the data contained therein. The scanner  10  is electrically joined to a suitable display  24  which may be used for displaying certain information encoded in the bar code  12 , such as the price of a consumer product represented thereby. When the bar code  12  is accurately scanned and decoded, the data may be presented on the display  24 , and a small speaker  26  operatively joined to the scanner  10  may beep to indicate successful decoding of the bar code  12 . 
   However, if the scanner  10  is unable to decode the bar code  12 , the speaker  26  will not beep and the display  24  will remain blank. Multiple passes of the bar code  12  over the scanner  10  may be attempted in order to properly read the label if possible, or if the bar code  12  is defective it cannot be read. 
   A probable cause of the scanner not reading or decoding the bar code correctly is that the bar code has a symbology that is not on the list of symbologies that the scanner uses during normal operation. If so the scanner may be switched to a second mode of operation, in which all symbologies known to the scanner are checked for. The scanner can be switched between the normal or first mode of operation and the second or universal mode in a number of different ways. For example, the operator or service personnel could scan a special bar code, press a switch  28  on the bar code scanner, press a key on a point of sale terminal (not shown) connected to the scanner, or any other means to communicate to the bar code scanner a command to initiate the second mode of operation, in which the scanner is enabled to read any bar code symbology that the scanner is capable of decoding. 
   The operator or service personnel would then scan the new bar code, which the scanner would then decode and, subsequently, inform the operator/service personnel of the bar code symbology and other pertinent details, such as, bar code length, etc. Multiple methods of informing the operator/service personnel of the bar code details could be used in one or more combinations and could include operator or customer displays  30 , speech from the scanner, speech from a point of sale terminal, printer output or any other method of communication known to a person skilled in the art. The operator/service personnel can then utilize that information to program the scanner to enable the decoding of that bar code type in the normal scanning mode. In other words if a bar code type is detected in the second mode of operation of the scanner, the scanner can be programmed to look for that symbology in the first or normal mode of operation from then on. 
   Alternatively, a different special bar code or command could be input into the bar code scanner to allow the bar code scanner not only to detect and communicate the new bar code type but would also allow the bar code scanner to program itself to be capable of scanning the new bar code type in the normal scanning mode. For example, if a new bar code can not be read by the scanner the scanner can be arranged to automatically review all of the symbologies with which it has been programmed and if the symbology of the bar code in question is found the bar code is read. The scanner may now also check for the new symbology during each scan operation thereafter. Alternatively, the scanner may then revert to its normal operation while logging the fact that the new symbology has been detected. The scanner may be required to detect the new bar code symbology a predetermined number of times before it looks for that symbology as part of its normal scanning operation. 
   Also, if a symbology has not been detected over a predetermined number of scan operations that symbology may be moved, either automatically, or via operator input, from the first mode to the second mode. 
   The foregoing description of the preferred embodiment of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto.