Abstract:
An electronic price label (EPL) which includes a plurality of separately-addressable displays. The EPL includes a housing, a first display identified by a first unique identification number, a second display within the housing identified by a second unique identification number, and circuitry within the housing for controlling each of the first and second displays in response to messages received by the circuitry which are addressed to the first and second displays using the first and second unique identification numbers.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to price display systems used in transaction establishments, and more specifically to an electronic price label (EPL) including a plurality of separately addressable displays. 
     EPL systems typically include a plurality of EPLs for each merchandise item in a store. EPLs typically display the price of corresponding merchandise items on store shelves and are typically attached to a rail along the leading edge of the shelves. A store may contain thousands of EPLs to display the prices of the merchandise items. The EPLs are coupled to a central server from where information about the EPLs is typically maintained in an EPL data file. Price information displayed by the EPLs is obtained from the PLU file. 
     EPLs today may be wired or wireless. Wireless EPLs may employ infrared or radio frequency (RF) transmitters. EPLs systems of the assignee of the present invention employ RF transmitters and modulated backscatter techniques. An EPL computer transmits polling signals to one or more EPLs. In order to respond to the poll, an EPL “reflects” the polling signal back to the EPL computer within a predetermined time interval of receiving the polling signal. A good analogy of the RF modulated backscatter acknowledgment signal is a mirror reflection. If two men face each other, one with a flashlight and the other with a mirror, the man with the mirror can send an acknowledgment to the man with the flashlight by reflecting the beam of light back to him. Similarly, the man with the mirror may indicate the opposite by not reflecting the light of the flashlight. 
     Modulated backscatter techniques are taught in U.S. Pat. No. 5,640,683, to Evans et al., entitled “Modulated Backscatter Wireless Communication System Having An Extended Range”, issued Jun. 17, 1997. This patent is hereby incorporated by reference. 
     Typical EPLs have limited functionality. They have small displays, limited memory, and a simple communications protocol. Functionality is usually limited because cost is limited. Uses for EPLs exist that cannot be satisfied by current EPLs. For example, current EPLs do not readily function as marketing tools that attract and inform customers, because they are incapable of displaying long promotional messages. Also, current EPLs are too large to be located on shelves adjacent small merchandise items. 
     Therefore, it would be desirable to provide an EPL including a plurality of separately addressable displays to solve these and other problems. 
     SUMMARY OF THE INVENTION 
     In accordance with the teachings of the present invention, an electronic price label (EPL) including a plurality of separately addressable displays is provided. 
     The EPL includes a housing, a first display identified by a first unique identification number, a second display within the housing identified by a second unique identification number, and circuitry within the housing for controlling each of the first and second displays in response to messages received by the circuitry which are addressed to the first and second displays using the first and second unique identification numbers. 
     In a first embodiment, the first display displays first information associated with a first merchandise item and the second display displays second information associated with a second merchandise item. 
     In a second embodiment, the first and second displays display a promotional message. 
     It is accordingly an object of the present invention to provide an EPL including a plurality of separately addressable displays. 
     It is another object of the present invention to combine a plurality of separately addressable EPLs into a single housing for displaying prices of a plurality of different merchandise items that are too small to permit mounting of a plurality of separately housed EPLs. 
     It is another object of the present invention to combine a plurality of separately addressable EPLs into a single housing with their displays arranged in adjacent fashion so as to create a single display which is larger than any one of the displays in the EPLs for displaying promotional messages. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Additional benefits and advantages of the present invention will become apparent to those skilled in the art to which this invention relates from the subsequent description of the preferred embodiments and the appended claims, taken in conjunction with the accompanying drawings, in which: 
     FIG. 1 is a block diagram of an EPL system; and 
     FIG. 2A is a block diagram of a first embodiment of an EPL in accordance with the present invention; 
     FIG. 2B is a block diagram of a second embodiment of an EPL in accordance with the present invention; 
     FIG. 3 is a detailed view of an EPL in accordance with the first embodiment of FIG. 2A; 
     FIG. 4 is a detailed view of another EPL in accordance with the first embodiment of FIG. 2A; and 
     FIG. 5 is a detailed view of an EPL in accordance with the second embodiment of FIG.  2 B. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to FIG. 1, EPL system  10  includes computer  12 , storage medium  14 , communication base station (CBS)  16 , electronic price labels (EPLs)  18 , and EPL  24  of the present invention. EPL system  10  makes use of modulated backscatter communication techniques. 
     Computer  12  executes EPL control software  20 . EPL control software  20  records, schedules, and transmits all messages to EPLs  18  and  24  through CBS  16 , and receives and analyzes messages from EPLs  18  and  24  through CBS  16 . Such messages may include price information and promotional information. 
     EPL control software  20  maintains and uses EPL data file  28 . EPL data file  28  contains item information, EPL identification information, and status information for each of EPLs  18  and EPL  24 . 
     EPL control software  20  primarily includes data scheduler  34  and CBS manager  36 . Data scheduler  34  schedules EPL price change messages to be sent to EPLs  18  and  24  through CBS  16 . 
     Storage medium  14  is preferably a fixed disk drive. Storage medium  14  stores EPL data file  28 . 
     CBS  16  preferably includes one transmit antenna  37  and from one to four receive antennas  38  for transmitting and receiving messages between CBS  16  and EPLs  18  and  24 . CBS  16  includes CBS circuitry  39  which controls operation of CBS  16 . EPL system  10  preferably includes a plurality of CBSs  16  connected together in series. 
     CBS manager  36  schedules transmission of price change messages and promotional messages to EPLs  18  and  24 . CBS manager  36  controls reception of status messages from EPLs  18  and  24 . 
     Turning now to FIG. 2A, a first embodiment of EPL  24  is illustrated. 
     In this embodiment, EPL  24  is a combination of a plurality of EPLs  18  which share a common battery  40 . Here, three EPLs  18  provide the hardware for EPL  24 . A first EPL  18  provides EPL circuitry  48 , memory  54 , display  60 , and transmit and receive antenna  66 . A second EPL  18  provides EPL circuitry  50 , memory  56 , display  62 , and transmit and receive antenna  68 . A third EPL  18  provides EPL circuitry  52 , memory  58 , display  64 , and transmit and receive antenna  70 . 
     Battery  40  provides power to EPL  24  and is more powerful than any single battery in EPLs  18 . 
     Displays  60 - 64  are preferably liquid crystal displays (LCDs). 
     Memories  54 - 58  store messages from EPL computer  12 . 
     EPL circuitries  48 - 52  store received messages from EPL computer  12  and transmit response messages to EPL computer  12 . EPL circuitries  48 - 52  have their own EPL identification numbers. Thus, EPL computer  12  communicates with EPL circuitries  48 - 52  as if they were separate EPLs  18 . 
     Transmit and receive antennae  66 - 70  transmit acknowledgment messages from EPL circuitries  48 - 52  and receive price change and other control messages from EPL computer  12 . Since EPL  24  is made from separate EPLs  18 , it operates in the same frequency range as EPLs  18 . 
     Turning now to FIG. 2B, a second embodiment of EPL  24  is illustrated. 
     In this embodiment, EPL  24  is also a combination of a plurality of EPLs  18 , except that EPL  24  includes a single battery  40 , transmit and receive antenna  42 , and display  46 . 
     Display  46  is preferably a liquid crystal display (LCD). Display  46  includes character segments  72 - 76  which preferably consist of eight characters each. EPL circuitry  48  communicates with character segment  72 . EPL circuitry  50  communicates with character segment  74 . EPL circuitry  52  communicates with character segment  76 . 
     This embodiment is particularly suited for displaying promotional messages, including scrolling promotional messages. The promotional messages are formed from the combination of characters displayed by character segments  72 - 76 . 
     Turning now to FIG. 3, an EPL  24  in accordance with the first embodiment of FIG. 2A is shown. EPL  24  includes a single housing  82  containing the components of FIG.  2 A. EPL  24  is particularly suited for displaying prices of items  84 - 88  which are arranged on shelf  80  in a manner that fails to permit mounting of single EPLs  18  due to lack of space. Separate displays  60 - 64  are shown for displaying prices of items  84 - 88 . Each of displays  60 - 64  is driven by its own EPL circuitry within EPL  24 . EPL computer  12  controls displays  60 - 64  by sending messages addressed to the EPL circuitries. Each of displays  60 - 64  includes a horizontal arrangement of characters. Here, eight characters are shown. 
     Turning now to FIG. 4, another EPL  24  in accordance with the first embodiment of FIG. 2A is shown. This EPL  24  provides a greater space savings than the EPL  24  of FIG.  3 . Each of displays  60 - 64  includes a horizontal and vertical arrangement of characters. Here, eight characters are shown, arranged four over four. 
     Turning now to FIG. 5, an EPL  24  in accordance with the second embodiment of FIG. 2B is shown. EPL  24  includes a single housing  82  containing the components of FIG.  2 B. EPL  24  is particularly suited for displaying promotional messages, including scrolling promotional messages. The promotional messages are formed from the combination of characters displayed by character segments  90 - 100 . 
     Smaller versions of this type of EPL  24  may also be used to display prices of items  84 - 88 . Here, display  46  includes six character segments  90 - 100 . Each of character segments  90 - 100  is driven by its own EPL circuitry within EPL  24 . EPL computer  12  controls character segments  90 - 100  by sending messages addressed to the EPL circuitries. 
     Although the present invention has been described with particular reference to certain preferred embodiments thereof, variations and modifications of the present invention can be effected within the spirit and scope of the following claims.