JP2008167968A - Electronic shelf label system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic shelf label system capable of easily determining whether or not a received radio signal is a proper response signal. <P>SOLUTION: In the electronic shelf label system, when a plurality of electronic shelf labels respectively receive merchandise data signals transmitted to their own devices, infrared signals modulated by code data including the code string of an M sequence are transmitted as the response signals in response to the reception. In the meantime, a communication device determines whether or not the infrared signals are the proper response signals on the basis of whether or not the code string of the M series can be obtained from the received infrared signals (step S15). Thus, whether or not the received infrared signal is the proper response signal is easily determined. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electronic shelf label system including a plurality of electronic shelf labels that are arranged corresponding to products and display product data relating to the corresponding products.

  In general, in a store such as a supermarket or a convenience store, the selling price of the product in the store is centrally managed by a product master stored in a POS system or the like. On the other hand, the selling price is transmitted to the consumer by a paper medium shelf label placed at the position of the product. Since management of such a paper medium shelf label must be relied upon manually, human error such as a mistake in selling price tends to occur. For this reason, there is a possibility that a selling price different from the settlement selling price by the register of the POS system is transmitted to the consumer.

  In order to solve such a problem, an electronic shelf label system (ESL system / Electronic Shelf Label System) has been put into practical use in recent years. In the electronic shelf label system, a portable electronic shelf label having a display for displaying product data such as selling price is arranged corresponding to each product. Then, a product data signal including the selling price based on the product master is distributed from the distribution side device to each electronic shelf label by wireless communication. Thus, the distributed selling price is displayed on each electronic shelf label, and the correct selling price that matches the settlement selling price can be transmitted to the consumer.

  When each electronic shelf label of the electronic shelf label system receives a product data signal related to its own device, it transmits a response signal, which is a radio signal called ACK, in response to this. The distribution-side apparatus can confirm that the selling price is normally displayed on the electronic shelf label based on the presence / absence of the response signal transmitted from the electronic shelf label in this way (see, for example, Patent Document 1). .)

JP 2001-5872 A

  By the way, in the conventional electronic shelf label system, an unmodulated carrier (carrier wave) is used as a response signal. For this reason, the distribution-side apparatus may recognize noise or the like as a response signal. If an incorrect signal is recognized as a response signal in this way, even if the electronic shelf label does not display the correct selling price, the electronic shelf label system cannot grasp it and the store staff cannot recognize it. . As a result, there arises a problem that the state in which the wrong selling price is transmitted to the consumer is maintained.

  The present invention has been made in view of the above problems, and an object thereof is to provide an electronic shelf label system that can easily determine whether or not a received wireless signal is a valid response signal.

  In order to solve the above-mentioned problem, the invention of claim 1 is characterized in that a plurality of electronic shelf labels that are arranged corresponding to products and display product data relating to the corresponding products, and the product data are stored in the plurality of electronic shelf labels. A distribution means for transmitting to each of the plurality of electronic shelf labels, wherein each of the plurality of electronic shelf labels receives the product data transmitted from the distribution means to the own device. And, in response to receiving the product data, signal transmission means for transmitting a radio signal modulated with code data including at least a predetermined code string as a response signal, and the distribution means transmits the radio signal A determination unit that determines whether or not the wireless signal is the valid response signal based on whether or not the predetermined code string is obtained from the signal receiving unit that receives the signal and the wireless signal received by the signal receiving unit. It has a, and.

  According to a second aspect of the present invention, in the electronic shelf label system according to the first aspect, the predetermined code sequence is a code sequence having a high autocorrelation characteristic.

  The invention of claim 3 is the electronic shelf label system according to claim 1 or 2, wherein the distribution means uses identification information for identifying each of the plurality of electronic shelf labels to transmit The product data is transmitted to the electronic shelf label, and the predetermined code string includes a code string indicating the identification information of the electronic shelf label that transmits the response signal.

  According to a fourth aspect of the present invention, in the electronic shelf label system according to any one of the first to third aspects, the code data includes the predetermined code string continuously.

  According to the first to fourth aspects of the present invention, since the legitimate response signal is modulated with code data including a predetermined code string, it is based on whether or not the predetermined code string can be obtained from the received radio signal. Thus, it is possible to easily determine whether the response signal is valid.

  In particular, according to the invention of claim 2, the response signal and the noise can be easily distinguished by performing autocorrelation of the code data obtained from the received radio signal.

  Further, according to the invention of claim 3, it is not a valid reply signal and transmission target based on whether or not a code string indicating identification information of the electronic shelf label to be transmitted can be obtained from the received radio signal. A response signal from an electronic shelf label can be distinguished.

  In particular, according to the invention of claim 4, even when noise that becomes code data including a predetermined code string occurs by chance, it is possible to easily distinguish between noise and a legitimate response signal.

<1. M-sequence code sequence>
Hereinafter, an embodiment of the present invention will be described. In this embodiment, an M-sequence (Maximum length sequence) code string is used. The M-sequence code string is a code string having a feature of high autocorrelation characteristics. Before describing the specific configuration and operation of the embodiment of the present invention, first, a method and characteristics of generating an M-sequence code string will be described.

  FIG. 1 is a diagram illustrating an example of an M-sequence generation circuit 90 for generating an M-sequence code string. The M series generation circuit 90 includes a shift register 91 and an exclusive OR (EXOR) gate 92.

  The shift register 91 is composed of four registers R1 to R4 each capable of storing a 1-bit code of “0” or “1”. The codes stored in the registers R1, R2, and R3 of the shift register 91 are transferred to the registers R2, R3, and R4 adjacent on the downstream side (right side in the figure) for each clock. The code stored in the most downstream register R4 is output for each clock and used as the output code of the M-sequence generation circuit 90.

  The exclusive OR gate 92 performs an exclusive OR operation for two given codes (an operation that is “0” when the two given codes are the same and “1” when the two given codes are different). It is. The exclusive OR gate 92 receives the code stored in the most downstream register R4 and the code stored in the second register R3 from the most downstream for each clock. The operation result of the exclusive OR gate 92 is input to the most upstream register R1.

  Here, it is assumed that the signs “1”, “0”, “0”, and “0” are stored as initial values in the registers R1, R2, R3, and R4, respectively. In this case, “0” of the register R4 is output as an output code of the M-sequence generation circuit 90 after one clock. The registers R2, R3, and R4 receive “1”, “0”, and “0” of the registers R1, R2, and R3, respectively. Further, the register R1 receives “0” as a result of exclusive OR between “0” of the register R3 and “0” of the register R4.

  If such processing is continued for each clock, the codes of the registers R1 to R4 and the output code of the M-sequence generation circuit 90 change as shown in FIG. After 15 clocks, 15 codes “000100110101111” are generated as output codes. The code string generated in this way is an M-sequence code string. Note that after 15 clocks, the signs of the registers R1 to R4 return to the initial values. Therefore, thereafter, the M-sequence generation circuit 90 repeatedly outputs a code string having the same pattern (that is, an M-sequence code string) as an output code in a 15 clock cycle.

  Here, it is considered that the M-sequence code string is correlated with itself (autocorrelation). That is, as shown in FIG. 3, in the M-sequence code string and its copy (self), the corresponding codes are multiplied, and the sum of those products is further calculated. At this time, the code “0” included in the M-sequence code string is converted to “−1”. When autocorrelation is taken in this way, the resulting correlation value is “15”.

  Next, it is considered that the M-sequence code string is correlated with the code sequence shifted by one bit (shifted in phase). In this case, as shown in FIG. 4, the correlation value is “−1”.

  Similarly, assuming that the correlations with those shifted by 2 bits, 3 bits,..., 14 bits are taken, the correlation value is “−1” in either case. Therefore, as shown in FIG. 5, in consideration of a graph in which the horizontal axis represents the shift amount and the vertical axis represents the correlation value, the correlation value is “15” only when the shift amount is “0”, and the correlation values are the other shift amounts. The value is “−1”. That is, a sharp peak value appears only when the shift amount is “0” (that is, when there is no phase difference). As described above, the M-sequence code string is a code string having high autocorrelation characteristics. In other words, it can also be expressed as a code string having a correlation characteristic that shows a clear peak only when it coincides with itself without phase shift.

  Therefore, when the M-sequence code string correlates with itself, a markedly different correlation is obtained as compared with the case where the M-sequence code string is correlated with another code string (for example, noise). Will be detected.

  In the embodiment of the present invention specifically described below, the response signal is used as another signal (for example, noise) by using the M-sequence code string having such a high autocorrelation characteristic as the response signal. Is to be distinguished from

<2. Configuration>
FIG. 6 is a diagram illustrating a state in which the electronic shelf labels included in the electronic shelf label system according to the present embodiment are arranged on the product shelf of the store. As shown in the figure, the product shelf 60 is divided into spaces called faces 61, and the same type of products 6 are collected and placed on each face 61.

  The electronic shelf label 5 is attached to the frame 62 of the product shelf 60 at a position corresponding to each face 61. That is, each electronic shelf label 5 is associated with one product 6 (more precisely, one product type), and a frame 62 in the vicinity of the corresponding product 6 (generally, the lower side of the product 6). Placed in. Each electronic shelf label 5 has a display, and product data including the selling price of the corresponding product 6 is displayed on the display. The customer (consumer) of the store recognizes the selling price of the product 6 by such display of the electronic shelf label 5.

  The electronic shelf label 5 is a portable device, and can be removed from the frame 62 and rearranged at another position so as to cope with the change in the arrangement of the product 6. In the present embodiment, a plurality of product shelves 60 as shown in FIG. 6 are arranged in the sales space in the store.

  FIG. 7 is a diagram illustrating a configuration example of a store information system including the electronic shelf label system 1 applied to a store. As shown in the figure, the store information system 100 includes a store controller 2 and a POS system 3 along with the electronic shelf label system 1. The POS server 31 included in the POS system 3 and the ESL server 10 included in the electronic shelf label system 1 are connected to the store controller 2 via the LAN 21. Thereby, data communication is enabled among the store controller 2, the POS system 3, and the electronic shelf label system 1.

  The store controller 2 is composed of a general computer and functions as a device that manages the store information system 100 in an integrated manner. In addition, the store controller 2 is connected to an external network such as the Internet, and can communicate with a computer such as a server device disposed in a headquarter center that manages the store in an integrated manner via the external network.

  The POS system 3 is a system that collects and analyzes information related to the sale of products at the time of sale, and includes a plurality of registers 32 that perform product settlement together with a POS server 31 that collectively manages the POS system 3. ing. The POS server 31 and the register 32 are connected by a dedicated communication cable.

  The POS server 31 is composed of a general computer, and the hard disk stores a product master 301 indicating various information (product data) related to products such as selling prices. In each of the plurality of registers 32, the product is settled based on the selling price described in the product master 301.

  Product data relating to all products in the store is centrally managed by the product master 301. The product data described in the product master 301 includes a “product code” that is product identification information, a “product name” that is the name of the product, a “normal price” that is a normal selling price, and a “sale price” that is a selling price in a sale. “Price”, “Special Sale Period”, which is a period for executing special sale, and the like are included.

  The electronic shelf label system 1 is broadly divided into a plurality of electronic shelf labels 5 described above and a distribution side device 40 that distributes product data to be displayed on the electronic shelf labels 5.

  The distribution-side device 40 includes an ESL server 10 that is a server device that manages the electronic shelf label system 1 in an integrated manner, and a plurality of communication devices 4 that perform wireless communication with each electronic shelf label 5. The ESL server 10 and the plurality of communication devices 4 are connected to each other via a dedicated communication cable 22 so that data communication is possible between them. The plurality of communication devices 4 perform wireless data communication with each electronic shelf label 5 using infrared signals. The communication device 4 is arranged at a substantially constant distance on the ceiling of the sales space so that it can communicate with all the electronic shelf labels 5 arranged in the sales space.

  The configuration of the ESL server 10 as hardware is the same as that of a general computer. FIG. 8 is a diagram showing the configuration of the ESL server 10. The ESL server 10 includes a CPU 11 that performs various arithmetic processes, a ROM 12 that stores basic programs, a RAM 13 that serves as a work area for the arithmetic processes, a hard disk 14 that stores programs and various data files, a display 15 that performs various displays, a keyboard, An input unit 16 composed of a mouse or the like, a data communication unit 17 having a data communication function via the LAN 21, and an interface 18 for communicating with the communication device 4 are provided. Product data to be transmitted to the electronic shelf label 5 is transmitted to the communication device 4 via the interface 18.

  A dedicated program is stored in advance in the hard disk 14 of the ESL server 10, and various functions as the ESL server 10 are realized by the CPU 11 performing arithmetic processing according to the program. The hard disk 14 of the ESL server 10 stores a product file 101 that is a data file indicating various information (product data) related to the product.

  FIG. 9 is a diagram illustrating an example of the product file 101. As shown in FIG. 9, the product file 101 has a table format, and each record 102 indicates information related to one product. Specifically, “product code”, “product name”, “normal price”, “sale price”, “sale period”, and the like are registered for each record 102. These pieces of information are the same information as the product master 301 stored in the POS system 3 described above, and are registered based on the information in the product master 301 through communication between the ESL server 10 and the POS system 3. For this reason, the information in the product file 101 and the information in the product master 301 are the same.

  Further, in each record 102 of the product file 101, one “device code” which is identification information unique to each of the plurality of electronic shelf labels 5 included in the electronic shelf label system 1 is registered. Thereby, the product and the electronic shelf label 5 are associated with each other in a one-to-one relationship. By using this “device code”, product data of a product is transmitted to the electronic shelf label 5 corresponding to the product.

  Next, the communication device 4 will be described. FIG. 10 is a block diagram illustrating a configuration of the communication device 4. As shown in FIG. 10, the communication device 4 includes a control unit 41 that controls each unit of the device, a light emitting unit 42 that transmits an infrared signal, and a light receiving unit 43 that receives the infrared signal. The light emitting unit 42 includes, for example, an LED capable of emitting infrared light, and outputs an infrared signal modulated with data to be transmitted to the electronic shelf label 5 as a product data signal IR1. Such data to be transmitted includes product data and a device code of the electronic shelf label 5 to be transmitted.

  The light receiving unit 43 includes a photodiode capable of receiving infrared light, for example, and receives an infrared signal. When each electronic shelf label 5 of the electronic shelf label system 1 receives the product data signal IR1 intended for transmission of its own device, in response to this, the binary data of predetermined code data ("0" or "1") is received. An infrared signal modulated with a data consisting of a code is transmitted as a response signal IR2. The response signal IR2 transmitted from the electronic shelf label 5 is received by the light receiving unit 43. In addition to the function of receiving such infrared signals, the light receiving unit 43 also has a function of demodulating the received infrared signals and acquiring code data.

  The control unit 41 is configured by, for example, a hardware circuit, and has a function of controlling each unit of the apparatus and performing various calculations. In FIG. 10, the light emission control unit 44, the correlation unit 46, and the determination unit 45 schematically show functions realized by the control unit 41. A part of the function of the control unit 41 may be realized in software (by calculation according to a program such as a CPU).

  The light emission control unit 44 controls the light emission unit 42 based on data given from the ESL server 10. Thereby, from the light emission part 42, the infrared signal modulated with the data given from the ESL server 10 is output as the product data signal IR1. The correlation unit 46 also correlates the code data obtained from the infrared signal received by the light receiving unit 43 and the M-sequence code string. The determination unit 45 determines whether the infrared signal received by the light receiving unit 43 is a valid response signal IR2 based on the correlation result in the correlation unit 46, and transmits the determination result to the ESL server 10. Details of these functions will be described later.

  Next, the electronic shelf label 5 will be described. FIG. 11 is a diagram showing an external configuration of the electronic shelf label 5. As shown in FIG. 11, on the front surface of the electronic shelf label 5, a display unit 50 for displaying product data such as the selling price of the corresponding product, and a product data signal IR1 transmitted from the communication device 4 of the distribution side device 40. And a light emitting unit 53 that transmits a response signal IR2.

  The display unit 50 is composed of a display device such as a liquid crystal display or electronic paper, and can display various information such as character strings, symbols, and figures as well as numerical values indicating the selling price of goods. Here, the “electronic paper” is a non-volatile display device that can electrically rewrite the display content and can maintain the display content even when the drive power is not supplied.

  The light receiving unit 52 includes, for example, a photodiode capable of receiving infrared rays, and receives a product data signal IR1 and also has a function of demodulating the received product data signal IR1 to acquire data. The light emitting unit 53 includes, for example, an LED capable of emitting infrared light, and outputs a response signal IR2.

  In addition, the electronic shelf label 5 includes a control unit 51 that is a hardware circuit having a function of controlling various units of the apparatus and performing various calculations. FIG. 12 is a block diagram showing the configuration of the electronic shelf label 5 including the function of the control unit 51. In FIG. 12, the reception confirmation unit 54, the memory 55, the display control unit 56, the light emission control unit 57, and the M series generation unit 58 schematically show functions realized by the control unit 51. Note that some of the functions of the control unit 51 may be realized in software (by calculation according to a program such as a CPU).

  The reception confirmation unit 54 confirms whether or not the product data signal IR1 received by the light receiving unit 52 is intended for transmission of the device itself. This confirmation is performed based on whether or not the device code included in the data obtained by demodulating the product data signal IR1 matches the device code of the own device. The device code of the own device is stored in the memory 55 in advance. The display control unit 56 controls the display unit 50 to display the product data included in the data obtained by demodulating the product data signal IR1 on the display unit 50. The M sequence generator 58 generates an M sequence code string. As the configuration of the M-sequence generator 58, the same configuration as that shown in FIG. 1 can be adopted.

  Further, the light emission control unit 57 controls the light emitting unit 53 to cause the light emitting unit 53 to transmit a response signal IR2. Under the control of the light emission control unit 57, the light emission unit 53 outputs an infrared signal modulated based on the code data including the M-sequence code string generated by the M-sequence generation unit 58 as the response signal IR2. The light emission control unit 57 causes the light emission unit 53 to transmit a response signal IR2 in response to the reception confirmation unit 54 confirming the reception of the commodity data signal IR1 related to its own device.

<3. Operation>
Next, the operation of the electronic shelf label system 1 will be described. In the electronic shelf label system 1, when the normal selling price of the product file 101 (product master 301) is changed at the time of starting the system, or when a special sale for a limited time is performed, the electronic shelf label system 40 receives the electronic shelf label system 1. The product data signal IR 1 is transmitted to 5.

  When the electronic shelf label system 1 is activated, the product data signal IR1 is transmitted for all the electronic shelf labels 5 in the store. On the other hand, when the normal selling price is changed and when special sale is performed, the product data signal IR1 is transmitted only for the electronic shelf label 5 corresponding to the corresponding product. In this way, the display price of the electronic shelf label 5 and the settlement price of the register 32 are always matched by transmitting the product data signal IR1 as necessary.

  Hereinafter, operations of the distribution side device 40 and the electronic shelf label 5 when the product data signal IR1 is transmitted from the distribution side device 40 to the electronic shelf label 5 will be described.

  FIG. 13 shows a flow of operations when the distribution side device 40 transmits a product data signal IR1 related to a certain product. First, in the ESL server 10, the product file 101 is referred to, and product data such as the selling price related to one product and the device code of the electronic shelf label 5 associated with the product are acquired. The acquired product data and data including the device code are transmitted from the ESL server 10 to each communication device 4 (step S11).

  Subsequently, in each communication device 4, the light emission unit 42 is controlled by the light emission control unit 44 based on the data transmitted from the ESL server 10. Thereby, the product data signal IR1 which is an infrared signal modulated by the data is transmitted from the light emitting unit 42 to the electronic shelf label 5 (step S12).

  FIG. 14 is a diagram showing a flow of operations of the electronic shelf label 5 that has received the product data signal IR1. In the electronic shelf label 5, when the light receiving unit 52 receives the product data signal IR1 (step S21), the reception confirmation unit 54 confirms whether or not the received product data signal IR1 is for the device itself. Is done. That is, it is determined whether or not the device code included in the data obtained by demodulating the product data signal IR1 matches the device code of its own device in the memory 55 (step S22).

  If the device code obtained from the product data signal IR1 does not match the device code of its own device (No in step S22), the received product data signal IR1 is a signal intended for transmission of another electronic shelf label 5. Therefore, the operation ends as it is.

  On the other hand, when the device code obtained from the product data signal IR1 matches the device code of the own device (Yes in step S22), the received product data signal IR1 is a signal intended for transmission of the own device. Therefore, the product data included in the data obtained by demodulating the product data signal IR1 is displayed on the display unit 50 under the control of the display control unit 56 (step S23).

  Further, in response to the reception of the commodity data signal IR 1, a response signal IR 2 that is an infrared signal modulated with predetermined code data is transmitted from the light emitting unit 53 under the control of the light emission control unit 57. As shown in FIG. 15, the code data Cd includes the M-sequence code string generated by the M-sequence generator 58 continuously (step S24).

  Returning to FIG. 13, after the transmission of the product data signal IR1 (after step S12), the distribution side device 40 is in a state of waiting for a response signal IR2 from the electronic shelf label 5. If the reply of the response signal IR2 from the electronic shelf label 5 cannot be confirmed for a predetermined time, it is determined that the communication is poor (Yes in step S13, step S18).

  Further, when the light receiving unit 43 of the communication device 4 receives any infrared signal in a state of waiting for the reply signal IR2 as described above (Yes in step S14), the received infrared signal is a valid response signal. It is determined whether it is IR2 (step S15).

  That is, first, the received infrared signal is demodulated by the light receiving unit 43 to obtain code data. Next, the correlation unit 46 correlates the obtained code data with the M-sequence code string. This M-sequence code string is the same as that generated in the M-sequence generator 58 of the electronic shelf label 5. When a significant correlation is detected in the correlation result of the correlation unit 46, the determination unit 45 determines that the received infrared signal is a valid response signal IR2. That is, it is determined whether or not the received infrared signal is a valid response signal IR2 based on whether or not the code data includes an M-sequence code string.

  As described above, the M-sequence code string has high autocorrelation characteristics. Therefore, when the code data does not include the M-sequence code string, the correlation with the M-sequence code string is low, but when the code data includes the M-sequence code string, the correlation with the M-sequence code string is remarkable. To be high. Therefore, when a significant correlation is detected in the correlation result of the correlation unit 46, the M-sequence code string is included in the code data obtained from the received infrared signal.

  Note that even if code data obtained from noise accidentally includes an M-sequence code string, it is almost impossible to include an M-sequence code string continuously. In the present embodiment, since the code data used for the response signal IR2 includes the M-sequence code string continuously, even if noise that becomes the code data accidentally including the M-sequence code string occurs, It is possible to easily distinguish the noise from the legitimate response signal IR2.

  As the configuration of the correlator 46, for example, the configuration shown in FIG. The correlation unit 46 includes an M-sequence generation unit 71 and a correlation calculation unit 72. The M-sequence generator 71 generates the same M-sequence code string as the M-sequence generator 58 of the electronic shelf label 5. The correlation calculation unit 72 performs a correlation calculation between the code data and the M-sequence code string generated by the M-sequence generation unit 71. As the correlation calculation method, the same method as described above with reference to FIGS. 3 to 5 may be employed. In this case, if the output correlation value is “15”, it can be determined that the code data includes an M-sequence code string.

  Further, as the configuration of the correlation unit 46, the configuration shown in FIG. The correlation unit 46 includes a shift register 73 having four registers R5 to R8 and two exclusive OR gates 74 and 75.

  The exclusive OR gate 74 receives the code stored in the most downstream register R8 and the code stored in the second register R7 from the most downstream. On the other hand, the exclusive OR gate 75 receives the operation result of the exclusive OR gate 74 and the code data. The code data is also input to the most upstream register R5.

  The operation performed by the shift register 73 and the exclusive OR gate 74 is the same as the operation performed by the shift register 91 and the exclusive OR gate 92 of the M series generation circuit 90 shown in FIG. Therefore, if the code data given to the correlation unit 46 is an M-sequence code string, the exclusive OR gate 75 is always given the same code. In other words, “0” is always output from the exclusive OR gate 75. Therefore, for example, when “0” is output from the exclusive OR gate 75 for the number of times corresponding to one period of the M-sequence code string (15 times in the present embodiment), the code data is M-sequence. It can be determined that the code string is included.

  Returning to FIG. 13, if it is determined that the code data obtained from the received infrared signal includes an M-sequence code string and the received infrared signal is a valid response signal (Yes in step S <b> 16). The determination result is notified to the ESL server 10, and the process ends normally (step S17). On the other hand, if it is determined that the received infrared signal is not a response signal (No in step S16), the determination result is notified to ESL server 10, and distribution side device 40 again waits for a response signal IR2. Return to state. As described above, since the process is normally completed only when a valid response signal is received, it is possible to avoid a state in which a state in which an incorrect selling price is transmitted to the consumer is maintained.

  As described above, in the electronic shelf label system 1 according to the present embodiment, when each of the plurality of electronic shelf labels receives the product data signal IR1 transmitted to the device itself, An infrared signal modulated with code data including the code string is transmitted as a response signal IR2. On the other hand, the communication device 4 determines whether or not the infrared signal is a valid response signal based on whether or not a predetermined code string is obtained from the received infrared signal. For this reason, it can be easily determined whether or not the received infrared signal is a valid response signal.

  The code data used for the response signal includes an M-sequence code having high autocorrelation characteristics as a predetermined code string. For this reason, if autocorrelation of code data obtained from the received infrared signal is performed, a significant correlation is detected if it is a valid response signal. For this reason, the response signal and the noise can be easily distinguished based on the correlation result. Further, even if the sensitivity of the light receiving unit 43 is reduced, it is possible to eliminate the influence of such sensitivity reduction by the gain generated by autocorrelation.

<4. Second Embodiment>
Next, a second embodiment will be described. Since the configuration and operation of the electronic shelf label system 1 of the present embodiment are substantially the same as those of the first embodiment, the differences will be mainly described below. In the first embodiment, only the M-sequence code string is included in the code data used for the reply signal IR2. In the present embodiment, the electronic shelf label 5 that is the source of the reply signal IR2 is used. The code data further includes a code string indicating the device code.

  FIG. 18 is a diagram conceptually showing the configuration of the code data of the present embodiment. As shown in the figure, the code data Cd according to the present embodiment includes a code string indicating a device code at the head thereof, and subsequently includes M-sequence code strings continuously.

  When the electronic shelf label 5 transmits the response signal IR2, in the present embodiment, the light emission control unit 57 acquires the device code of the own device from the memory 55 (see FIG. 12). The light emission control unit 57 controls the light emission unit 53 based on code data obtained by combining the code string indicating the device code and the repetition of the M-sequence code string output from the M-sequence generation unit 58. To do. As a result, a response signal IR2 modulated with the code data is transmitted from the light emitting unit 53.

  FIG. 19 is a block diagram illustrating a configuration of the communication device 4 according to the present embodiment. The communication device 4 according to the present embodiment further includes a memory 47 and a comparison unit 48 as functions of the control unit 41 in addition to the same configuration as that of the communication device 4 shown in FIG.

  The memory 47 stores a code string indicating a device code included in data given from the ESL server 10 when the product data signal IR1 is transmitted. That is, a code string indicating the device code of the electronic shelf label 5 that is the transmission target of the product data signal IR1 is recorded.

  Further, the comparison unit 48 compares the code data obtained from the infrared signal received by the light receiving unit 43 with a code string indicating the device code stored in the memory 47 and compares the code data indicating the device code with the code data. Determine if a column is included.

  As described above, the memory 47 stores a code string indicating the device code of the electronic shelf label 5 that is the transmission target of the product data signal IR1. On the other hand, the code data obtained from the response signal IR2 includes a code string indicating the device code of the electronic shelf label 5 as the transmission source. The electronic shelf label 5 that transmits the legitimate response signal IR2 is the electronic shelf label 5 that is the latest transmission target of the commodity data signal IR1. Therefore, if the received infrared signal received by the light receiving unit 43 is a valid response signal IR2, the code data obtained by demodulating it should include the code string of the device code stored in the memory 47.

  In the present embodiment, when the light receiving unit 43 of the communication device 4 receives any infrared signal (Yes in step S14 in FIG. 13), the code data acquired from the received infrared signal is combined with the correlation unit 46. It is also input to the comparison unit 48. The correlation unit 46 correlates the code data and the M-sequence code string in the same manner as in the first embodiment. On the other hand, in the comparison unit 48, it is determined whether or not the code string of the device code stored in the memory 47 is included in the code data.

  The correlation result in the correlation unit 46 and the comparison result in the comparison unit 48 are input to the determination unit 45. In the determination unit 45, significant correlation is detected in the correlation result of the correlation unit 46, and the code string of the device code stored in the memory 47 in the comparison result of the comparison unit 48 is included in the code data. When it is determined that the received infrared signal is present, it is determined that the received infrared signal is a valid response signal IR2.

  In the failed electronic shelf label 5, there is a case where the response signal IR2 is erroneously returned even when the product data signal IR1 intended for transmission by another device is received. Such a reply signal IR2 that is erroneously transmitted from other than the electronic shelf label 5 that should be transmitted causes a malfunction of the electronic shelf label system 1. However, as in the present embodiment, the code data used for the response signal IR2 includes the code string indicating the device code of the electronic shelf label 5 that is the transmission source, so that the electronic data that is not the transmission target of the product data signal IR1. Even when a response signal is erroneously transmitted from the shelf label 5, such an erroneous response signal and a legitimate response signal can be reliably distinguished.

<5. Other embodiments>
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications are possible. Hereinafter, such other embodiments will be described. Of course, you may combine the form demonstrated below suitably.

  In the above embodiment, an M-sequence code string is used as a code string having high autocorrelation characteristics, but other code strings having similar properties such as a Barker code string may be used.

  In the above embodiment, the M-sequence code string is configured by 15 codes, but may be configured by more codes.

  In the second embodiment, the code data used for the response signal includes a code string indicating the device code and a continuous M-sequence code string. However, only the code string indicating the device code is included. May be included. The code data used for the response signal may include a code string indicating the device code continuously.

  In the above embodiment, an infrared signal is used as the product data signal and the response signal. However, other wireless signals such as a radio wave signal and a visible light signal may be used.

  Further, in the electronic shelf label system, the user may be able to select the operation between the first embodiment and the second embodiment by switching the operation mode. When switching the operation mode, a control signal indicating the operation mode after switching may be transmitted to each electronic shelf label 5.

It is a figure which shows an example of the M series production | generation circuit for producing | generating an M series code sequence. It is a figure which shows the change of the code | symbol in an M series production | generation circuit. It is a figure which shows an example of the correlation calculation of the code sequence of M series. It is a figure which shows an example of the correlation calculation of the code sequence of M series. It is a figure which shows the correlation result of the code sequence of M series. It is a figure which shows a mode that the electronic shelf label was arrange | positioned at the goods shelf. It is a figure which shows the structural example of the shop information system containing an electronic shelf label system. It is a figure which shows the structure of an ESL server. It is a figure which shows the example of a goods file. It is a block diagram which shows the structure of the communication apparatus of 1st Embodiment. It is a figure which shows the external appearance structure of an electronic shelf label. It is a block diagram which shows the function structure of an electronic shelf label. It is a figure which shows the flow of operation | movement of the delivery side apparatus. It is a figure which shows the flow of operation | movement of an electronic shelf label. It is a figure which shows the structure of the code data of 2nd Embodiment. It is a figure which shows an example of a structure of a correlation part. It is a figure which shows an example of a structure of a correlation part. It is a figure which shows the structure of the code data of 2nd Embodiment. It is a block diagram which shows the structure of the communication apparatus of 2nd Embodiment.

Explanation of symbols

4 communication device 5 electronic shelf label 10 ESL server 40 distribution side device 45 determination unit 46 correlation unit 48 comparison unit 57 light emission control unit 58 M sequence generation unit IR2 response signal

Claims (4)

An electronic shelf having a plurality of electronic shelf labels that are arranged corresponding to the products and display product data relating to the corresponding products, and a distribution unit that transmits the product data to each of the plurality of electronic shelf labels A bill system,
Each of the plurality of electronic shelf labels is
Data receiving means for receiving the product data transmitted from the distribution means toward the device;
In response to receiving the product data, a signal transmitting means for transmitting a radio signal modulated with code data including at least a predetermined code string as a response signal;
With
The delivery means includes
Signal receiving means for receiving a radio signal;
Determining means for determining whether or not the radio signal is a valid response signal based on whether or not the predetermined code string is obtained from the radio signal received by the signal receiving means;
An electronic shelf label system comprising: The electronic shelf label system according to claim 1,
The electronic shelf label system, wherein the predetermined code string is a code string having high autocorrelation characteristics. The electronic shelf label system according to claim 1 or 2,
The distribution means uses identification information for identifying each of the plurality of electronic shelf labels, and transmits the product data to an electronic shelf label to be transmitted.
The electronic shelf label system, wherein the predetermined code sequence includes a code sequence indicating the identification information of the electronic shelf label that transmits the response signal. The electronic shelf label system according to any one of claims 1 to 3,
The electronic shelf label system, wherein the code data includes the predetermined code string continuously.

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