Abstract:
An optical scanner for use at a checkout counter determines information relating to products to be purchased, including coded label data. The scanner supplies the information to a cash register system. The scanner includes a scanner controller for reading coded labels on the products. The scanner further includes an interface circuit, mounted in said scanner and receiving power therefrom, for providing coded label data to said cash register system.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates generally to a scanner system and an interface for data gathering systems of the type used at point of sale checkout counters. More particularly, the present invention relates to a scanner having an improved interface for providing communications between an optical scanner and a host system, such as for example an IBM 4683 cash register system, to facilitate the transfer of data from the scanner to the cash register system. 
     Supermarket checkout counters commonly include optical scanners mounted therein for optically scanning bar code labels on products to be purchased as the products are moved over scanning windows in the top surfaces of the scanners. Such a scanner reads the bar code labels and transmits the bar code data to the cash register system via an interface which in the past has been a separate, external system component. The bar code data may include product identification and pricing information which is used for the sale and other mechandising purposes, such as inventory control. 
     In the past there has been considerable difficulty in interfacing bar code scanners of this type with certain cash register systems. The requirement of a separate, external interface circuit has increased the cost and complexity of such systems. Specifically noted as a difficult cash register system to link via an interface is the IBM 4683 Cash Register System. The specifications regarding communication with this system are unique and exacting. In the past it has been common to provide a separate, external interface to reconfigure data prior to its submission to the 4683 Cash Register System. Further, such a separate system has typically required its own, separate power supply. 
     It is seen, however, that there is a need for an improved interface for use with bar code scanners and cash register systems, and for such an interface which is capable of receiving power from any of several sources. 
     SUMMARY OF THE INVENTION 
     This need is met by an optical scanner according to the present invention for determining information relating to products to be purchased and providing such information to a cash register system. The scanner scans coded labels on the products and provides a signal indicative of the coded label data. The scanner includes scanning controller means, mounted in and responsive to the optical scanner, for identifying the data on the bar code labels; and interface means, mounted in the optical scanner and responsive to the scanning controller means, for providing coded label data to the cash register system. 
     The scanning controller means includes a bar code decoder circuit for decoding scan signals to provide coded label data. The scanning controller means also includes a scanner microprocessor for correlating coded label data and supplying the coded label data to the common interface circuit, and scanner memory means for storing control software for use by the scanner microprocessor. 
     The interface means comprises an interface microprocessor, responsive to coded label data from the scanning controller means; interface memory means for storing control software for use by the interface microprocessor; and a driver circuit, responsive to the interface microprocessor, for supplying coded label data to the cash register system. 
     A power means provides power to the interface means. The interface power means providing power from the scanner as long as such power is available and, subsequently, provides power for the interface from the cash register system. 
     An optical scanner for use at a checkout counter to determine information relating to products to be purchased, including coded label data, and to supply the information to a cash register system, comprises a scanner controller for reading coded labels on the products, and an interface circuit, mounted in the scanner and receiving power therefrom, for providing coded label data to the cash register system. 
     An interface power means provides power to the interface means from the scanner as long as such power is available and, subsequently, provides power for the interface from the cash register system. The scanner controller includes a bar code decoder circuit for decoding scan signals to provide coded label data, a scanner microprocessor for correlating coded label data and supplying the coded label data to the interface circuit, and memory means for storing control software for use by the scanner microprocessor. The interface circuit comprises an interface microprocessor, responsive to coded label data from the optical scanning means, memory means for storing control software for use by the interface microprocessor, and a driver circuit, responsive to the interface microprocessor, for providing coded label data to the cash register system. 
     Accordingly, it is an object of the present invention to provide a scanner capable of communicating directly with a cash register system; to provide such a scanner including an internal interface; to provide such a scanner including an interface which may receive its power from either the scanner or the cash register system; and to provide such a scanner in which the interface includes a programmed microprocessor to facilitate interface operation. 
     Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an electrical schematic representation of the scanner controller, interface circuit, and associated circuitry, which provides weight data and coded label data to the cash register system; 
     FIGS. 2A and 2B, when assembled with FIG. 2A to the left of FIG. 2B, represent schematically the scanner controller of FIG. 1 in greater detail; and 
     FIGS. 3A and 3B, when assembled with FIG. 3A to the left of FIG. 3B, represent schematically the interface circuit of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Reference is made to FIG. 1 of the drawings which illustrates schematically an optical scanner 200 according to the present invention for determining information relating to products to be purchased and providing such information to a cash register system 202. The scanner 200 scans coded labels on the products and the scanner optics 204 of conventional construction provide a signal on line 206 indicative of the coded label data. The scanner 200 includes scanning controller means 208, mounted in the optical scanner 200 and responsive thereto, for identifying the data on the bar code labels. The scanner 200 further includes interface means 210, mounted in the optical scanner 200, and responsive to the scanning controller means 208, for providing coded label data to the cash register system 202, which may be an IBM Model 4683 cash register system. 
     The optical scanner controller 208 includes a bar code decoder circuit 212 for decoding scan signals to provide coded label data. Circuit 212, preferably an NCR VLSI decoder circuit, in combination with gate array and timer circuit 224, decodes label segment data received on line 206. Scanner microprocessor 214 correlates the coded label data received from circuit 212 and supplies the coded label data to the interface circuit 210 under control of control software stored in scanner memory means 216, preferably comprising an EPROM. Scanner microprocessor 214 is preferably an INTEL 8039 microprocessor. 
     The interface circuit 210 comprises an interface microprocessor 218, responsive to coded label data from the scanner controller 214. Microprocessor 218 is preferably a ZILOG Super8 microprocessor. Interface circuit 210 also includes an interface memory means 220, preferably an EPROM, for storing control software for use by the interface microprocessor 218. A driver circuit 222 is responsive to the interface microprocessor 218 for supplying weight data and coded label data to the cash register system 202. 
     Reference is made to FIGS. 2A and 2B which, when assembled with FIG. 2A to the left of FIG. 2B, collectively illustrate schematically the circuitry of scanner controller 208. A pulse stream is provided on lines 206, labeled &#34;RTV˜&#34; and &#34;STV˜&#34;, which defines the width of successive bars and spaces read by the scanner optics across a bar code label. These widths are quantified by timer circuit 224 which counts the number of 36 MHz cycles between start-of-low and start-of-high signals defining these widths. The decoder chip 212 then decodes segments of the bar code data and supplies these segments to microprocessor 214 where they are correlated. The correlated data is transmitted to the interface circuit 210 over lines 226. Lines 227 are connected to appropriate audible and visual indicators to signal the operator that a scan has been made (&#34;GDLT&#34;), or that a scan has not been made (&#34;BDLT&#34;). The line labeled TONE activates an audible signal. 
     Reference is made to FIGS. 3A and 3B which, when assembled with FIG. 3A to the left of FIG. 3B, schematically illustrate the interface circuitry 210 in greater detail. The interface circuit 210 includes an interface power means, comprising relay 228, for providing power to the interface means. As is apparent, the relay 228 provides power from the scanner on line 230 as long as such power is available and, subsequently, provides power for the interface from the cash register system via line 232 when the scanner power is terminated. Thus, it is assured that the interface 210 will receive power, even in the event that either the scanner 200 or the cash register system 202 should lose power. 
     The interface microprocessor 218 is reset by means of power-on sensor circuit 234 when the power to the system is turned on. Bidirectional communication with the scanner controller 208 is provided via buffer 236. Similarly, bidirectional communication is provided with the cash register system via driver 222. Data transmitted to the driver 222 via the line &#34;TXD&#34;, while information may be received from the cash register system via the line &#34;RXD&#34;. Control signals are received from the controller 208 via lines 238 and sent to the controller 208 via lines 240. 
     The control software stored in scanner controller memory means 216 may be exemplified by the following listing. ##SPC1## 
     The control software stored in interface memory means 220 may be exemplified by the following listing. ##SPC2## 
     It can be seen therefore that the scanner of the present invention, including an internal interface, provides significant advantages over prior art systems of the type including a separate interface connecting a scanner to the cash register system. Furthermore, it will be appreciated that this interface circuit produces superior communication between the scanner and the cash register system. 
     Having described the invention in detail and by reference to the preferred embodiment thereof, it will be apparent that other modifications and variations are possible without departing from the scope of the invention defined in the appended claims.