Abstract:
Systems and techniques for electronic shelf label (ESL) battery replacement are described. A first embodiment includes an ESL having a single battery and two battery compartments. A replacement battery is placed within the empty battery compartment before the old battery is removed. In a second embodiment, an ESL includes a single battery situated in a single battery compartment, and a large value capacitor connected in parallel with the battery which maintains the contents of the ESL&#39;s volatile RAM while the single battery is changed. In a third embodiment, an ESL includes two battery compartments, a single battery and a large value capacitor connected in parallel with the battery. In another aspect, an ESL displays instructions for changing the ESL battery. The ESL includes a pushbutton for user input which allows the user to cycle through multiple battery change instructions. These instructions may be stored in locally in the ESL or may be transmitted to the ESL from a host system.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present invention is related to the following commonly assigned and co-pending U.S. application: 
     Ser. No. 09/250,858, entitled “Electronic Price Label Battery Storage Apparatus And Replacement Method”, filed Feb. 17, 1999, and incorporated by reference herein in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to improvements in electronic shelf label (ESL) systems used in transaction establishments. More specifically, the present invention relates to improved methods and apparatus for replacing an ESL battery. 
     BACKGROUND OF THE INVENTION 
     ESL systems typically include a plurality of ESLs for each merchandise item in a store. ESLs 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 ESLs to display the prices of the merchandise items. The ESLs are coupled to a central server where information about the ESLs is typically maintained in an ESL data file which contains ESL identification information and ESL merchandise item information. The central server sends messages, including price change messages, to the ESLs. 
     Typical ESLs include a battery which provides power for the display and electronic circuitry contained in the ESL, including power to maintain the display contents and ESL identification number information stored in volatile random access memory (RAM). One prior art ESL includes a single battery permanently sealed inside the ESL. This approach reduces the production cost of the ESL, but does not allow a user to replace the battery when its charge is exhausted. Another prior art ESL contains two batteries wired in parallel with a lockout mechanism which discourages the user from removing both batteries at the same time. While this approach allows the user to replace one of the batteries without losing the information stored in the volatile RAM, it also increases the cost of the ESL due to the requirement for two batteries. 
     SUMMARY OF THE INVENTION 
     The present invention advantageously provides methods and apparatus for improved electronic shelf label (ESL) battery replacement. A first embodiment of the present invention includes an ESL having a single battery and two battery compartments connected in parallel. A replacement battery is placed within the empty battery compartment before the old battery is removed. In a second embodiment of the present invention, an ESL includes a single battery situated in a single battery compartment, and a large value capacitor connected in parallel with the battery which maintains the contents of the ESL&#39;s volatile RAM while the single battery is changed. In a third embodiment of the present invention, an ESL includes two battery compartments, a single battery and a large value capacitor connected in parallel with the battery compartments. 
     In another aspect, the present invention includes an ESL which displays instructions for changing the ESL battery. The ESL includes a pushbutton for user input which allows the user to cycle through multiple battery change instructions. These instructions may be stored locally in the ESL or may be transmitted to the ESL from a host system. 
     A more complete understanding of the present invention, as well as further features and advantages of the invention, will be apparent from the following detailed description and the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a block diagram of a transaction management system in accordance with the present invention; 
     FIG. 2 is a block diagram of an ESL in accordance with the present invention; 
     FIG. 3 shows a rear view of a first embodiment of an ESL in accordance with the present invention; 
     FIG. 4 shows a block diagram of an ESL in accordance with one aspect of the present invention; 
     FIG. 5 shows a block diagram of an ESL in accordance with another aspect of the present invention; 
     FIG. 6 shows a rear view of a second embodiment of an ESL in accordance with the present invention; 
     FIG. 6A shows an ESL circuit diagram in accordance with the present invention; 
     FIG. 7 illustrates a first method of replacing an ESL battery in accordance with the present invention; and 
     FIG. 8 illustrates a second method of replacing an ESL battery in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION 
     The present invention now will be described more fully with reference to the accompanying drawings, in which several presently preferred embodiments of the invention are shown. This invention may, however, be embodied in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. 
     FIG. 1 shows a transaction management system  100  in accordance with the present invention. The system  100  includes a host computer system  102  and a point-of-service (POS) system  104 . Here, components  102  and  104  are shown as separate components that are networked together, but they and their subcomponents may also be combined or divided in various ways. Thus, host computer system  102  may be a POS terminal which doubles as a host computer for a network of other POS terminals. 
     The host computer system  102  includes a storage medium  106 , system software  108 , ESL software  110 , a display  112  and an input device  114 . The storage medium  106  includes a PLU data file  107  which stores item prices which are available for distribution to a POS terminal  116  by the host system  102 . Alternatively, provision may be made for a bar code scanner  118  to directly access the PLU data file  107 . The storage medium  106  also includes ESL data file  109  which contains item information, such as a PLU number and ESL identification information for each of the ESLs  122 . The system  102  executes system software  108  which updates the contents of storage medium  106  and performs other system functions, as described in greater detail below. Input device  114  is preferably a keyboard, but it will be recognized that data can be entered in a variety of alternative manners. 
     POS system  104  includes bar code scanner  118  and POS terminal  116 . 
     The system  100  also includes relay units  120  and ESLs  122 . The relay units  120  may be suitably mounted in or near the ceiling of the retail establishment. 
     ESL software  110  records, schedules, and transmits all messages to ESLs  122 . ESL software  110  controls the transmission of messages, including price change messages, to ESLs  122  utilizing relay units  120  which are placed periodically across a retail establishment. These messages are sent to the relay array units  120  through communications link  124 . Communications link  124  may suitably utilize radio frequency (RF) communication, infrared (IR) communication, a wired link, or some combination of communication techniques. After receiving a message from the host system  102 , the relay units  120  then transmit the message to the ESLs  122  utilizing a further communications link  126 , which may suitably utilize RF communication, IR communication, a wired link or some combination of communication techniques. In an alternate embodiment, host system  102  may communicate directly with ESLs  122 . 
     After receiving a message, the ESLs  122  may respond with an acknowledgement which is transmitted to the relay units  120  over communication link  127 . The relay units  120  would then retransmit the acknowledgement message to the host system  102  over communication link  124 . 
     FIG. 2 shows a block diagram of the ESL  122  in accordance with the present invention. A display  202  displays information, such as item price and related data. ESL  122  includes a transmitter/receiver  206  for transmitting messages and receiving messages. The transmitter/receiver may utilize RF communication, IR communication, a wired link or some combination of communication techniques. A power source  208  provides power for the operation of ESL  122 . The operation of ESL  122  is controlled by ESL circuitry  204 . ESL circuitry  204  decodes incoming messages received, and performs any actions indicated by the messages. For example, if a price change message is received, the ESL circuitry  204  would cause the display  202  to be updated with the new price information. Volatile RAM  210  stores the ESL identification number and the displayed message. ESL circuitry  204  may also include a variety of components such as timers and other electronic components. Additionally, ESL circuitry  204  may monitor power source  208  to determine if an adequate power supply is being provided. 
     FIG. 3 shows a rear view of a first embodiment of an ESL  122   a  in accordance with the present invention. The ESL  122   a  includes a first battery compartment  302  and a second battery compartment  304  which are connected in parallel, allowing power to be supplied to the ESL  122   a  from a battery in either compartment. A battery door  306  slides within two channels  308  to cover either the first battery compartment  302  or the second battery compartment  304 . In a preferred embodiment, the ESL  122   a  is equipped with only a single battery  310  which may be initially placed in the second battery compartment, for example. In FIG. 3, the battery door  306  is shown in the half-open position for illustration purposes. Normally, the battery door  306  would be positioned over the battery compartment containing the battery  310 . Since only a single battery  304  is present during normal operation, the battery door  304  may be half as wide as prior art battery doors, resulting in a cost savings. 
     When the battery  310  needs to be replaced due to a low charge, with the door  306  covering the battery  310 , a user inserts a new battery  310  into the empty battery compartment, slides the battery door  306  over the new battery, and then removes and discards the old battery. By inserting the new battery into the empty compartment before the old battery is removed from the other compartment, power is never removed from the volatile RAM, preserving its contents. To help insure the correct order of steps, the door  306  may include a statement, such as “Insert new battery first”, or the like. 
     In another aspect of the present invention, an ESL  122   b  displays instructions describing how to properly replace the battery  310 . FIG. 4 shows a block diagram of the ESL  122   b  in accordance with the present invention. The ESL  122   b  may suitably include all of the same elements as ESL  122   a  with the addition of a pushbutton  220 , or other user input element. When pressed, the pushbutton  220  causes the ESL circuitry  204  to transmit a message to the host system  102 . During normal operation, the host system may periodically query the ESL to determine if the battery is low and needs replacement. When the battery  310  needs to be replaced, the host system  102  sends a message to the ESL  122   b  causing the ESL to display a first message containing a first instruction step describing how to replace the battery. Such a first message may be “Change battery—push button for further instructions”, for example. 
     When the user who will perform the battery replacement pushes the pushbutton  320 , the ESL  122   b  sends a message to the host system  102  providing an indication that the user has pressed the button. The host system then sends a message to the ESL  122   b  causing the ESL to display a second message containing a second instruction step, such as “Insert new battery into empty compartment and push button to continue”, for example. Each incremental button push causes the ESL  122   b  to display the next instruction in the sequence. For example, the next instruction may be “Move battery door to cover new battery and push button to continue” followed by the succeeding instruction “Remove old battery and push button to continue.” Pushing the button after the final instruction causes the ESL  122   b  to return to displaying normal price information. 
     In another aspect of the present invention, an ESL  122   c , as shown in FIG. 5, may include a switch  230  which is used by the ESL circuitry  204  to detect when the ESL  122   c  is attached to a shelf rail or other mount. When the ESL circuitry  204  detects that the ESL  122   c  is detached from its mount and the battery power is low, the ESL  122   c  begins to display battery change instructions. Rather than receiving the battery change instructions from the host system, these battery change instructions may be stored in RAM or ROM included within the ESL  122   c.    
     FIG. 6 shows a rear view of a second embodiment of an ESL  122   d  in accordance with the present invention. The ESL  122   d  includes a single battery compartment  602 . A battery door  606  slides within two channels  608  to cover the battery compartment  602  containing a battery  610 . In FIG. 6, the battery door  306  is shown in partially open position for illustration purposes. Normally, the battery door  306  would be positioned over the battery compartment containing the battery  610 . As seen in a circuit diagram  652  of FIG. 6A, the ESL  122   d  includes a capacitor  650  to temporarily maintain the contents of volatile RAM  652  while a single battery  654  is being replaced. The capacitor  650  may be 500 μF, for example, to allow the contents of the volatile RAM  652  to be maintained for 60 seconds, for example. The battery  654  is connected in parallel with the capacitor  650 , the volatile RAM  656 , and other ESL circuitry  658 . 
     In a third embodiment of the present invention, advantageous aspects of the first and second embodiments are combined to minimize the chances of losing power during battery replacement. An ESL in accordance with the third embodiment of the present invention includes the two battery compartments with the single battery from the first embodiment, and the capacitor from the second embodiment. 
     FIG. 7 shows a method  700  of replacing an old battery with a new battery in an ESL, such as ESL  122   a , in accordance with the present invention. In a first step  702 , a user ensures that a battery cover is covering the old battery contained in a first battery compartment, and that a second battery compartment is exposed and empty. In step  704 , the user inserts the new battery into the second compartment. In step  706 , the user slides the battery cover to cover the new battery. In step  708 , the user removes the old battery. 
     FIG. 8 shows a method  800  of replacing an old battery with a new battery in an ESL in accordance with the present invention. In step  802 , the ESL determines if the battery is low. Additionally, the ESL may also determine if the ESL has been removed from its mounting. In step  804 , the ESL displays a first instructional message to a user, providing the user with a first step of battery replacement instructions. This message may be read from local ESL memory or transmitted from a host system. In step  806 , the user performs the first step of the instructions. In step  808 , the user provides an indication to the ESL that the first step has been completed. In a preferred embodiment, step  808  is accomplished by the user depressing a pushbutton. In step  810  the ESL determines if all replacement instructions have been displayed. If all instructions have not been displayed, steps  804 - 808  are repeated for each additional instruction. If all instructions have been displayed, then in step  812  the ESL begins displaying normal information, such as price information. 
     It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the present invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.