Abstract:
A wireless system for self-service shopping is described that includes a customer identification device with an optically readable code, a portable terminal that includes an optical code reader, a local area radio, a terminal controller, and a locking mechanism, a master station, consisting of a master controller and a master radio, and a receiving rack for the portable terminals to which the scanners may be locked using the locking mechanism. A customer presents his or her identification device to a terminal which reads the code, the code is transferred by radio to the master controller which checks the identification and, if valid, sends an authorized signal by radio to the terminal to unlock the scanner. In addition, several locking mechanisms are described that are controlled by the terminal controller. An additional feature provides a shopping cart with a receiving cradle for a portable terminal that allows the customer to lock the scanner onto the cart for hands-free shopping.

Description:
REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. patent application Ser. No. 08/907,785 filed Aug. 8, 1997, now pending. 
    
    
     BACKGROUND OF INVENTION 
     This invention relates to wireless optical scanning devices, locking mechanisms for use in self-service shops, and improved locking arrangements for portable data acquisition terminals. 
     DESCRIPTION OF THE RELATED ART 
     Self service optical scanning systems have been described that allow shoppers in self-service stores to shop by taking items off of shelves, scanning the items&#39; identifying bar code with a portable terminal, placing the items in their shopping cart, and checking out without standing in long lines. Check-out is simplified and made more efficient because the customer in charged for the items previously scanned, e.g. by reading out a memory of the terminal. The system generates an itemization and account of purchases is possible without the need for the cashier to scan the items individually. A store can use this system to reduce the need for cashiers and for processing regular customers more quickly. 
     U.S. Pat. No. 5,468,942 describes a self-service system having a scanner terminal dispensing device that is accessible from two sides. The dispensing apparatus holds the terminals and includes a customer identification station whereat a customer presents an ID card and, upon confirmation of the customer&#39;s identity, the host computer sends a data signal through the dispenser apparatus to release a terminal for use by the customer. 
     The disclosed configuration requires that each terminal station on the dispensing rack be wired for data communication with the host computer in order for the computer to release a selected terminal among many terminals and to enable data communication between the host computer and the terminals. This wiring can be extensive, making the dispensing rack costly to assemble and maintain. It is an object of the present invention to provide improved self-service shopping systems and improved terminal locking mechanisms. 
     SUMMARY OF THE INVENTION 
     In accordance with one aspect of the present invention, there is provided an improved method of controlling release of a terminal from a terminal storage rack. According to the method, user identification data is entered into the terminal to operate a lock mechanism in response to the data entry. 
     The user identification data may be entered manually or by scanning a user identification device. The release may be under control of a master controller which communicates with the terminal. 
     In accordance with another aspect of the invention, user identification may be presented to a master controller using a machine-readable device or by keying. 
     In accordance with the invention there is further provided a data acquisition system having a simplified terminal storage rack wherein a host computer communicates with the portable terminals via radio-frequency. According to the invention there is provided customer identification device, a portable terminal that includes an optical code reading device, a terminal radio, a programmed terminal controller, and a locking mechanism. There is further provided a master station that includes a master radio and a programmed master controller, and a terminal receiving and dispensing rack that has terminal receiving positions that engage the terminal locking mechanism. The terminal controller is programmed to cause the terminal radio to send data to the master station and to respond to unlock signals from the master station to operate the locking mechanism. The master controller is programmed to receive codes from the master radio, to process the codes, and to cause the master radio to send unlock signals. The data acquisition system may be a self-service shopping system. 
     In accordance with the invention there is further provided a cradle for a terminal on a shopping cart. The cart includes a terminal receiving station for receiving and engaging the terminal and the locking mechanism on the terminal is released when the terminal reads a customer identification device. One way to perform the identification is using a terminal controller to verify the customer authorization. Identification can also be performed by a master station that sends radio signals to the terminal to verify the customer authorization. 
     In accordance with the invention there are provided a variety of alternative arrangements for locking a terminal to a receiving rack, either internal or external to the terminal and controlled by the master controller via the terminal controller. One locking arrangement contains a solenoid operating a lock on the terminal and is activated by RF signals from a master controller. A second locking arrangement contains a solenoid on the terminal receiving rack, and its release may be activated by RF signals to the terminal, which provides electrical signals to operate the solenoid on the receiving rack. 
     For a better understanding of the present invention together with other and further objects thereof, reference is made to the following description, taken in conjunction with the accompanying drawings, and its scope will be pointed out in the appended claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a block diagram of a wireless self-service shopping system. 
     FIG. 2 is a plan elevation view of a terminal receiving rack. 
     FIG. 3 is a perspective view of a terminal. 
     FIG. 4 is a partial cross-sectional view of a first embodiment of a terminal and receiving rack. 
     FIG. 5 is a diagram of a shopping cart with a terminal receiving cradle. 
     FIG. 6 is a cross-sectional view of an alternate terminal locking mechanism. 
     FIG. 7 is a schematic diagram for a first locking circuit usable with the FIG. 6 locking mechanism. 
     FIG. 8 is a schematic diagram for an alternate locking circuit usable with the FIG. 6 locking mechanism. 
     FIG. 9 is a cross-sectional view of a further alternative terminal locking mechanism. 
     FIG. 10 is a perspective view of a portable terminal having two terminal members. 
     FIG. 11 is an alternative embodiment of a portable terminal. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 is a block diagram of one embodiment of the present invention which comprises a wireless self-service shopping system. This particular embodiment includes terminals  10  and a master station  16 . The terminal  10  includes a terminal controller  12 , a terminal, radio  13 , an optical reading device  14 , and a locking mechanism  15 . The master station  16  includes the master controller  17 , the master radio  18  and may include a customer ID reader  20 . 
     The terminal radio and master radio may be a local area wireless network system, such as the Spectrum24® system available from Symbol Technologies, Inc., the assignee of this application. In a shopping environment, a customer can use a terminal to record items to be purchased while shopping. The terminal may either retain the data in its own memory and download to the master station when the customer completes his or her shopping and returns the terminal  10  to a rack or the terminal may transfer the data to the master station as items are scanned. The terminal may also signal to the master station to obtain data relating to item and price for display to the customer on the terminal. 
     In a first embodiment, in an arrangement similar to that described in U.S. Pat. 5,468,942, the customer presents an identification device to an ID reader  20  associated with master station  16 . In this embodiment, the identification device may take on a variety of forms, including a magnetic stripe card, smart card or a card having an optical-readable bar code encrypting customer identification. In this first embodiment, the master station  16  will verify the customer&#39;s authorization in master controller  17 , select a terminal  10  for use by the customer and signal the terminal  10  using local area network master radio  18 . The signal  19  from master station  16  is decoded by terminal controller  12  and used to activate locking mechanism  15 . In addition, terminal controller  12  may activate a signal light  21  and/or a buzzer on the terminal to signal the customer which terminal  10  has been activated and unlocked. The master controller may also additionally or alternately display the terminal location to the customer as will be described. 
     FIG. 2 shows an arrangement of terminals  10  in a terminal receiving and dispensing rack  24 . It should be understood that dispensing rack  24  may take on a variety of configurations, such as the two-sided terminal dispensing device shown in U.S. Pat. No. 5,468,942 or a round carousel type terminal dispensing device (not shown). Dispensing rack  24  includes a plurality of shelves  26  each having a plurality of terminal sockets  28  for receiving terminals  10  in a locked configuration. At each terminal socket  28  there are provided connectors that allow electrical power to be provided to a terminal  10  when docked, for charging the battery in terminal  10 . Alternately, power may be provided to the terminals by induction. Because the data, corresponding to items to be purchased or customer identification, which is scanned by terminal  10  can be relayed to the master station  16  by radio signal  19 , it is not necessary to provide data connections in dispensing rack  24 , simplifying the wiring thereof. In addition, it is unnecessary to provide wiring to unlock sockets in rack  24 , since this function is also provided by radio link. 
     In accordance with a second embodiment, the customer identification device  34 , shown in FIG. 3 includes an optically readable identification code  36 . The customer can checkout a terminal  10  by placing identification device  34  in front of the optical reader  14  of terminal  10  while the terminal is in the receiving rack, whereby the code  36  is read and relayed by terminal controller  12  and terminal radio  13  to master station  16 . At master station  16  the authorization of the customer is verified by master controller  17  and, upon verification, an unlock signal is sent to terminal  10  by master radio  18 . In either embodiment master controller  17  records the identification of the terminal  10  and customer code  36 . Alternatively, the customer identification device could be a smart card (either contact or non-contact) or card with magnetically stored data. The optical reader would be replaced with the corresponding reading device. 
     Terminal  10  is provided with a liquid crystal or similar display  35  for identifying and providing display of the price of an item being scanned. When the item is scanned by pressing the “plus” button  37 , the item and price will be added to the customer&#39;s bill. When the item is scanned while pressing the “minus” button  37 , the item will be deleted from the bill, as when a customer changes his mind about a purchase and wishes to return an item previously scanned to a shelf. The “equals” button  37  provides the customer with a total of the items being purchased and may also indicate the total number of items scanned. Those skilled in the art will recognize that other functions may also be provided on terminal  10 . 
     During use, a record of items purchased is either maintained in terminal  10  or in master station  16  or both. When the terminal is returned to a rack, the terminal signals the master station that the customer has finished shopping and the master station may cause a statement to be printed. The customer then takes the statement to a cashier to pay for the purchased items without waiting for item-by-item check out. Alternately the customer might present the identification at the cashier and the cashier&#39;s terminal will retrieve a statement from the master station. Upon return of the terminal  10  to the rack  24 , the terminal reads a bar code with its optical reader. The bar code identifies the location of the terminal in the rack so that it can be stored in the master controller for subsequent use. 
     In either embodiment, it is desirable for the master controller to rotate the selection of terminals by customers, so that terminals are subjected to even wear and tear, and so that terminals have sufficient time in rack  24  for recharging. In the event selection is made at a remote entry station, assignment may also be made by height where the customer is physically challenged. Selection of terminals in the first system embodiment can be controlled by master controller  17 , which selects the terminal and causes illumination or flashing of signal light  21 . Light  21  will be extinguished when the terminal  10  is removed from its socket  28  in rack  24 , the removal being sensed by the absence of external power, or if the terminal is not removed from its socket  28  within a predetermined time period. 
     In the first embodiment it may be desirable for a display on master station  16  to indicate to a customer the location of the terminal that has been unlocked in addition to the activation of signal light  21 . For this purpose rack  24  is provided with coded socket tags  32 , which in the embodiment shown in FIG. 2 comprise bar code tags  32  arranged in a position enabling reading by the optical reader  10  of a terminal when the terminal is in a socket  28 . In the rack embodiment of FIG. 2, code tags  32  are arranged on tag support members  30 . When an unlock signal is sent to a terminal  10 , the optical reader of that terminal is activated to read code tag  32  and signal the master station, thereby indicating the location of the selected terminal, which can also be displayed to the customer at master station  16 . 
     In the second system embodiment, wherein the customer identification device  34  is read by the optical reader  14  of terminal  10 , the customer is generally free to select which terminal to present the identification device to. Uniform usage of terminals  10  can be controlled by providing one or more signal lights  21 ,  38  on terminals  10  (FIG. 3) to indicate to the customer which terminal to use. It should be noted that the master controller can be controlled to activate the terminal “ready” light  21  on less than all terminals that are actually in a ready-to-use condition, so that terminals are used in a uniform fashion. Thus, while all terminals may be charged and ready when a store opens, only a few might display a “ready” light  21 , while others show “not ready” light  38 , to control the customer selection. In an alternative embodiment, an entry station is provided which reads a customer card  34 , communicates the read data to the master controller  17 . The controller then communicates an assigned terminal on the entry station display. This permits the master controller to assign terminals in a manner which evenly distributes usage. This system requires a means for the terminal or rack  24  to communicate which of the terminals have a charged battery. In the preferred embodiment the radio  13  is used to communicate the information to the master radio. 
     Either of the two systems provide an operational check for the system at the time of dispensing a terminal. In the embodiment wherein the code tags  32  are read at the time of dispensing, the reading and transmission of the terminal location code assures operation of the optical reader  14  and local area radio  13  of terminal  10 . In the second embodiment, successful operation is confirmed by the successful reading of the identification code  36  on the customer identification card  34  and relay thereof to master station  16 . 
     Referring to FIG. 4, there is shown an example of a terminal mechanical arrangement for one possible locking mechanism useful in a system according to the present invention. FIG. 4 is a cross-sectional view of a base portion of a terminal  10  and terminal socket  28 . Terminal  10  includes a lower recess  40  which is sized and arranged to receive protrusion  42  within socket  28 . Within recess  40  there is provided an electrical connector  44 , which connects to a mating connector  46  on protrusion  42  when terminal  10  is placed fully into socket  28 . 
     Connectors  44 ,  46 , are provided to primarily supply current to terminal  10  from dispensing rack  24 . Accordingly, all positions on rack  24  have the same wiring in a relatively simple configuration. In other arrangements, additional wiring may be provided. 
     The locking mechanism of FIG. 4 includes a detent lever  48  pivotable about axis  50  and urged clockwise by compression spring  52 . When terminal  10  is inserted into socket  28 , projection  42  deflects lever  48  counterclockwise until the lower pawl  49  of lever  48  is received into slot  58  on projection  42 , locking the terminal into slot  28 . When an unlock signal is received by terminal  10 , current is supplied to solenoid coil  54  to draw armature  56  and rotate lever  48  counterclockwise to release terminal  10 . Those skilled in the art will recognize that other mechanical arrangements within terminal  10  are possible, and variations can include slide locks, rotating locks and release buttons to supply current to solenoid  54  only during the terminal removal process. 
     In the locking mechanism of FIG. 4, it is apparent that only fixed mechanical parts of the locking arrangement are provided on the rack  24  and socket  28 . Accordingly, it is easy to duplicate such mechanical configuration as part of a terminal cradle  60  provided on a shopping cart  62 . In this arrangement when a customer places the terminal  10  in the socket of terminal cradle  60 , it becomes locked therein and is released only when the customer again presents a customer identification device  34  to the optical reader of terminal  10 . Thus terminals used by different customers do not become mixed up, and a terminal checked out by one customer is not easily taken by another. 
     In the process of unlocking a terminal that has already been checked out by a customer from a terminal carrier  60 , the terminal controller or master controller verifies that the customer identification device  34  presented to the terminal is the same as the identification device used to check out the terminal. 
     FIG. 6 shows an alternate mechanical arrangement wherein the base of terminal  10  includes connector  44  and is received within socket  28 . In the FIG. 6 arrangement no projection is provided within socket  28 . Further, in the FIG. 6 arrangement a detent lever  64  is mounted on rack  24  adjacent socket  28 . Lever  64  pivots about axis  66  and is urged counterclockwise by tension spring  68 , Pawl  74  is arranged to engage slot  76  on terminal  10 . Solenoid coil  72  is arranged to draw armature  70 , rotating lever  64  clockwise to release terminal  10 . 
     While coil  10  is provided as part of rack  24 , which includes many sockets  28 , each requiring a locking mechanism, it is intended to avoid individual wiring to such coils and thereby simplify the rack wiring. This object is achieved by controlling current to coil  72  by terminal  10  using arrangements similar or equivalent to those described below. In particular, by arranging coil  72  as part of socket  28 , the added weight on terminal  10  is avoided and current for coil  72  can be provided by the stationary power supply rather than by the batteries of terminal  10 . 
     One arrangement for operating coil  72  using a control signal sent by radio link to terminal  10  is shown schematically in FIG.  7 . In this arrangement a positive going logic signal is provided through a pin of connectors  44 ,  46  from the terminal controller  12  to a relay transistor  78  which turns on current through coil  72 . Filter circuit  80  holds the coil current for a brief period until the terminal is withdrawn after the terminal controller signal is lost by the opening of the connector. Alternate arrangements, including providing transistor relay  78  on terminal  10  are apparent. Alternative to using a pin of connectors  44 ,  46 , to relay the control signal from terminal  10  to rack  24 , it is possible to provide optical signal coupling or magnetic coupling, for example using a reed switch. 
     Another arrangement for operating coil  72  without using an extra pin on the connectors is shown in FIG.  8 . In this arrangement the unlocking signal from terminal controller  12  turns on transistor  82  drawing a large current through resistor  84  on terminal  10 , overloading self-resetting fuse  86  on rack  24 . When fuse  86  opens, transistor  88  turns on drawing current through coil  72 . Following a delay which allows terminal  10  to be removed, fuse  86  resets, causing transistor  84  to turn off. 
     It will be recognized that the circuits of FIGS. 7 and 8 are not advantageous in a system wherein the terminal  10  is to be locked to terminal cradle  60  as shown in FIG. 5, since normally cradle  60  is not powered. It is possible, however, to supply power to cradle  60  from the battery on terminal  10 . 
     FIG. 9 shows a further alternative arrangement for a locking mechanism, which can be used with either rack  24  or terminal cradle  60 . In the FIG. 9 arrangement, coil  90  is carried by and operated by terminal  10  and used to attract armature  92  on lever  94  mounted to rack  24 . 
     From the foregoing it becomes evident that a wide range of terminal-activated locking arrangements can be used in connection with the terminals of the invention and that the examples set forth herein are exemplary only and not intended to limit the appended claims. In addition, those skilled in the art will recognize that the locking arrangements of the invention may be generally used with portable terminals to secure them when not being used and to enable such terminals to be released by an authorized user. In such arrangements, a terminal may be secured to a receiving rack at a user&#39;s workplace or in a user&#39;s vehicle and released only by scanning a user&#39;s identification device or alternately by a user entering a secret identification code on a terminal keyboard, keypad or touch screen display. 
     FIG. 10 illustrates a further configuration for use of the terminals  10  of the invention for alternative functions. In FIG. 10 it is seen that a first terminal member  100 , which corresponds, for example, to the self-service terminals previously described, may be attached by its base locking mechanism and connector to a second terminal member  101  which has projection  102  and connector  46 . By the addition of second member  101 , terminal  100  may be provided with enhanced functionality, for example for inventory scanning. Because inventory personnel typically use a terminal for a longer time period, second member  101  may include an additional battery to provide extended terminal use. In addition, second member  101  may be provided with extended memory containing an inventory operating program code and extra memory for inventory data. The second member can also include an alpha or numeric keypad  104 , whereby inventory personnel can, manually enter data corresponding, e.g., to the number of items in inventory corresponding to the scanned code. The second member may also include a printer for printing product tags and shelf tags, providing such information as pricing, restriction information and/or bar code symbologies. 
     In an alternative preferred embodiment, a heightened security system is provided for releasing the terminal from its locking mechanism. A user is provided with an optically coded data portion on a card such as a one dimensional or two dimensional bar code. Once this code is read by the system controller or terminal, as the case may be, the user is required to enter a pin code on a numeric keypad provided either on the terminal or in the vicinity of the card reader. This ensures that users who lose their cards will have additional protection from system abuse. 
     In an alternative preferred embodiment, the authorization code  36  is embedded in a PDF417 bar code, or some other form of coded symbology, stored on a customer identification device  34  in an encrypted format. The optical reader  14  on terminal  10  reads the encrypted data from the coded symbology, recovers a security code stored within the data and releases the locking mechanism only upon entry of the security code on data entry means on the terminal  10 . The security code could take on any one of numerous encryption and coding schemes. In an alternative embodiment, shown in FIG. 11, a terminal  10  is equipped with an alarm mechanism  110 . 
     The mechanism signals the system and/or store personnel that the terminal has been removed from the terminal rack without authorization. The alarm mechanism can have an audible and/or visual indicator  21  for signaling an unauthorized removal. Additionally, the mechanism may be connected to the local area radio  13 , for transmitting the unauthorized removal event to the master station. 
     The alarm mechanism can be implemented via an electro-mechanical switch. Removal of the terminal produces either a closure, or an opening, of the switch&#39;s electrical contacts. The contacts&#39; status is then communicated to the terminal controller which monitors the status of the terminal. If the removal of the terminal was authorized by the master station, the status of the electro-mechanical switch is ignored. Otherwise, the alarm is signaled. 
     Instead of an electro-mechanical switch, the alarm mechanism may utilize a rack-to-terminal proximity sensor. The physical removal of the terminal from the rack causes the sensing mechanism to change its status. Change of status is then acted upon by the terminal controller. 
     In alternative embodiments, the proximity sensor could be replaced by an electronic article surveillance (EAS) tag or a radio frequency identification device (RFID). 
     Regardless of the technology used, the goal is to have a system that can monitor a removal of the terminal from the terminal rack and appropriately signal an unauthorized terminal removal. 
     In addition to being able to monitor unauthorized removal of the terminal from the terminal rack, the system could also monitor removal of the terminal from inside the boundaries of a designated area. This will prevent theft of the terminals and inadvertent mistakes by customers who forget to return the terminal to the rack upon completion of their shopping transaction. 
     The implementation of the boundary sensing can be accomplished using RFID tag technology. Local access points can be set up throughout the designated area, typically the store, to monitor the location of the terminal. As long as the terminal is within the bounds of the designated area, the system behaves normally. As soon as, or with slight delay, the terminal is taken outside the access point area, the terminal senses loss of contact with the access points and enables the terminal alarm mechanism. This method of operation is useful because it reduces the store&#39;s risk of terminal loss. The communication between the terminal and the local access points can be achieved via a wireless RF communication LAN, such as the Spectrum24 network. It should be obvious to one skilled in the surveillance art that other embodiments of the security mechanism can be utilized. As long as the unauthorized removal of a terminal from the dispenser rack and from the designated boundary area can be monitored, the system&#39;s efficiency of operation can be increased and the store&#39;s risk of terminal loss or damage can be reduced. 
     While there have been described what are believed to be the preferred embodiments of the present invention, those skilled in the art will recognize that further changes and modifications may be made thereto without departing from the spirit of the invention, and it is intended to claim all such changes and modification as fall within the true scope of the invention. For example, although the present invention has been described in the context of a self-service shopping system, the invention may be applied to any terminal system whether employed in retail or other data collection system.