Electronic display systems

Abstract: In operation of an electronic display system in accordance with the present invention, a pseudo-price change command is transmitted by a base communications station to an individual electronic display module (10) and the strength of the acknowledgement signal returned by the individual electronic display module is observed and temporarily recorded. The base communications station then transmits a command to change the electronic display (12) on that particular electronic display module (10) to display a digital value indicative of the communication signal strength received by the base communications station.

Description: The present invention relates generally to electronic display systems. Large retail stores often deal with several tens of thousands of different kinds of goods. In such stores, much attention is paid to the management and control of the inventory of goods and the displaying and labelling of the prices of the goods being sold. Accordingly, much effort is expended and careful attention is paid to managing and controlling the stock of goods and to labelling prices of products displayed on shelves or in showcases. Mistakes as to the labelling of the prices of goods could cause dissatisfaction to customers and damage the reputation of the store. Therefore, it is desirable to correctly identify the prices of goods and minimize the number of pricing errors. Accordingly, electronic shelf display systems having multiple electronic display modules have been developed. EP-A-0 459 659 describes such a system. Such electronic display systems are typically arranged such that light weight compact electronic display modules which display the price of products, along with other product information, are placed on display shelves or showcases in front of the displayed products. These types of electronic display systems typically allow the prices of products displayed in the electronic display portions of the electronic display modules to be changed when the prices are raised or lowered and/or when the arrangement of goods displayed on the display shelves or showcases is changed. It is advantageous in such electronic display systems to have electronic display modules which are capable of providing acknowledgement of the receipt of transmitted price changes, as well as other transmitted information, to help identify "lost" or broken electronic display modules. In such electronic display systems, it becomes possible to reliably identify the correct prices of goods since changes in the prices of goods displayed on the electronic display portions of the electronic display modules are controlled and managed by a communications base system or some other processing control unit. If desired, other product information, for example inventory or stocking information, product identification numbers or codes, and product volume or weight, could be displayed on the electronic display modules. In addition, electronic display systems in accordance with the present invention could be used in applications other than retail store environments, for example in identifying inventory information in warehouses or distribution centres. When setting up electronic display systems which utilize wireless communication to and from a communications base station, it is normally desirable to maximize the communication signal strength received from the electronic display modules. A communication signal strength below a certain threshold value may result in the message not being received from the appropriate electronic display module. The communication signal strength received from electronic display modules is dependent on several factors, including the number and position of transmitting stations, the configuration and set-up of the building and its contents, the number and placement of fluorescent lighting fixtures and refrigeration units and many other factors. Because so many factors influence the strength of the communication signal received from individual electronic display modules, it is often desirable to optimize the communication signal strength received from individual electronic display modules by "trial and error" or by observing the communication signal strength received from an electronic display module under certain operating conditions, changing the operating conditions in some controlled manner, and observing the effect on the communication signal strength received from the electronic display module. Such a procedure has the disadvantage that it is time-consuming. In the past, a relatively sophisticated and expensive piece of equipment, for example a signal spectrum analyzer, was typically used to measure the communication signal strength at individual electronic display modules. Using such a separate piece of test equipment is disadvantageous in that it not only involves additional cost, but also in that a separate piece of test equipment must be carried to and from each individual electronic display module. In addition, a source of electrical power, such as a battery or electrical lead and outlet, is generally required to provide electricity for operation of such a separate piece of test equipment. Furthermore, using such a separate piece of test equipment may be cumbersome in certain locations, such as in freezers or other compact areas. Moreover, a signal spectrum analyzer or power meter can only measure the radio frequency signal strength at the electronic display module's location, whereas signal strength loss results from the two paths from the base communications station to the individual electronic display module and back to the base communications station. It is an object of the present invention to provide an electronic display system and method which substantially overcome the above-mentioned disadvantages of known procedures for assessing the communication signal strength received from individual electronic display modules. In accordance with one aspect of the invention there is provided an electronic display system including at least one electronic display module having an electronic display, an antenna arranged to receive communication signals from said at least one electronic display module and to transmit communication signals to said at least one electronic display module; and a base communications station arranged to send communication signals to said antenna for transmittal to said at least one electronic display module, to receive a return acknowledgement signal from said at least one electronic display module, and being characterised in that the base communication station is arranged to send back a communication signal having a value of the communication signal strength of said return acknowledgement signal received from said at least one electronic display module, for display on said electronic display of said at least one electronic display module. In accordance with another aspect of the invention there is provided a method of operating an individual electronic display module in an electronic display system, characterizing the steps of sending a communication signal from a base communications station; said individual electronic display module receiving said communication signal from said base communications station and returning a communication acknowledgement signal; said base communications station receiving said communication acknowledgement signal from said individual electronic display module and measuring the signal strength thereof; said base communications station transmitting a value corresponding to the strength of said acknowledgement signal; said individual electronic display module receiving said value from said base communications station; and said individual electronic display module displaying said value. An embodiment of the present invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 is a perspective view of an electronic display system, including a typical display showcase having multiple shelves and a plurality of shelf mounted electronic display modules; and Figure 2 is a front view of an electronic display module of the system of Figure 1. Referring to the drawings, an electronic display system in accordance with the invention includes a plurality of electronic display modules 10 each having an electronic display 12, preferably a liquid crystal display (LCD). As seen in Figure 1, the electronic display system includes a ceiling mounted antenna 20, which transmits signals to, and receives signals from, one or more of the electronic display modules 10. The antenna 20 also receives signals from, and forwards signals to, a base communications station (not shown) for processing. The electronic display modules 10 are shown mounted in a typical display showcase 22 such as is used in a retail store. The typical display showcase 22 shown in Figure 1 has a plurality of shelves 24, each shelf 24 having multiple electronic display modules 10 mounted thereon. In operation of the electronic display system, a pseudo-price change command is transmitted from the ceiling mounted antenna 20 addressed to a particular electronic display module 10. After receiving the pseudo-price change command signal, the particular electronic display module 10 returns an acknowledgement signal to the antenna 20. The base communications station observes the strength of the acknowledgement signal received from the particular electronic display module 10 and transmits a command to change the digital value of the "price" displayed on the electronic display module 10 to a digital value indicative of the received communication signal strength. In the typical display shown in Figure 2, a communication signal strength of "87" is displayed on the electronic display 12. The cycle of the base communications station receiving the acknowledgement signal from a particular electronic display module 10, observing its strength and returning a command to the relevant electronic display module 10 to display the communication signal strength can be repeated for as long as desired. This permits certain operating conditions to be changed to evaluate the impact of such changes on the strength of the communication signal received by a particular electronic display module 10. In one preferred embodiment, this cycle is repeated every six (6) seconds so that the communication signal strength being displayed on an electronic display module 10 represents the communication signal sent and received approximately six (6) seconds ago. While such a six (6) second cycle has been found to be adequate in providing timely feedback as to the communication signal strength being received from a particular electronic display module 10, the length of this cycle could be modified as desired. By permitting individual electronic display modules 10 to display the communication signal strength value received by the base communications station, it is possible for field service personnel to evaluate the electronic display system without a separate piece of test equipment. In addition, store personnel can readily perform communication signal strength evaluation in respect of individual electronic display modules 10. In a slightly different form, the electronic display system having electronic display modules 10 capable of displaying communication signal strength values on individual electronic display modules 10 can be useful in electronic display system diagnostics. Once installed in a fully populated environment, such as a retail store, the base communications system could sequentially check each individual electronic display module 10, for example at night or before a store's grand opening, and transmit a communication signal strength message to evaluate if there are some "dead spots" in the store, or if any electronic display modules 10 are receiving a communication signal having inadequate strength for effective communication. This would permit a field engineer, or some other individual, to verify communication signal strength, and take appropriate corrective measures, right at the locations where electronic display modules 10 are mounted. Electronic display modules 10 can also be moved around the store to act as portable, light-weight battery powered acknowledgement signal strength meters. A printout or report can be prepared which indicates the communication signal strength values observed in respect of each individual electronic display module 10. Such information can assist in determining the most effective placement of antennas, electronic display modules, display showcases, as well as other items within a store.

Claims: An electronic display system including at least one electronic display module (10) having an electronic display (12), an antenna (20) arranged to receive communication signals from said at least one electronic display module and to transmit communication signals to said at least one electronic display module; and a base communications station arranged to send communication signals to said antenna (20) for transmittal to said at least one electronic display module (10), to receive a return acknowledgement signal from said at least one electronic display module, and being characterised in that the base communication station is arranged to send back a communication signal having a value of the communication signal strength of said return acknowledgement signal received from said at least one electronic display module, for display on said electronic display of said at least one electronic display module. An electronic display system according to claim 1, characterized in that said electronic display (12) is a liquid crystal display (LCD). An electronic display system according to either claim 1 or claim 2, characterized in that said antenna (20) is mounted on a ceiling above said at least one electronic display module (10). An electronic display system according to any one of the preceding claims, characterized in that said at least one electronic display module (10) is mounted on a merchandise display showcase (22). A method of operating an individual electronic display module (10) in an electronic display system, comprising the steps of sending a communication signal from a base communications station; said individual electronic display module receiving said communication signal from said base communications station and returning a communication acknowledgement signal; said base communications station receiving said communication acknowledgement signal from said individual electronic display modulen, characterized by measuring the signal strength thereof; said base communications station transmitting a value corresponding to the strength of said acknowledgement signal; said individual electronic display module (10) receiving said value from said base communications station; and said individual electronic display module (10) displaying said value. A method according to either claim 5, characterized in that the series of steps of the method is repeated at approximately six second intervals. A method according to either claim 5 or claim 6, characterized in that said communication signal is a pseudo-price communication signal. A method according to claim 7, characterized in that said value is displayed as a digital value.

Inventors: WILKUS STEPHEN A, WILKUS, STEPHEN A.
Applicants: NCR INT INC, NCR INTERNATIONAL, INC.
Application year: 1995
Main classification: G06K7
IPC codes: G06K17