WO2014142009A1

WO2014142009A1 - Encoding apparatus

Info

Publication number: WO2014142009A1
Application number: PCT/JP2014/055839
Authority: WO
Inventors: 昌宏前田
Original assignee: 株式会社イシダ
Priority date: 2013-03-13
Filing date: 2014-03-06
Publication date: 2014-09-18
Also published as: JP2014179964A

Abstract

Provided is an encoding apparatus for encoding information data according to prescribed signal rules, the encoding apparatus generating encoding data for which a reception circuit is unlikely to cause an incorrect recognition of a bit value regardless of conditions on the reception circuit side. An encoding apparatus (50) is provided with an encoding unit (50a). The encoding unit converts 4-bit information data into N-bit (N ≥ 5) encoding data according to prescribed code rules. Under the code rules, bits in the encoding data having a value of "1" are not consecutive, and the number of bits in the encoding data having the value of "1" is 1 or 2, N being 7.

Description

Encoder

The present invention relates to an encoding device.

Conventionally, various methods are known as a method of encoding data to be transmitted on a transmission line. For example, Patent Document 1 (Japanese Patent Application Laid-Open No. 2008-103898) discloses that the code efficiency is better than the PPM (Pulse Position Modulation) method and the CMI (Coded Mark Inversion) method, and the receiving circuit is synchronized with the encoded data. An encoding method that is easy to take is disclosed.

However, when data encoded by the encoding method of Patent Document 1 (Japanese Patent Laid-Open No. 2008-103898) is transmitted to the receiving circuit, depending on the conditions on the receiving circuit side (for example, the receiving circuit Depending on the characteristics and the installation state of the receiving circuit such as the distance between the receiving circuit and the transmitter), the following problems may occur.

Here, as an example, encoded data is transmitted using infrared communication to a receiving circuit 100 having a photodiode 101, a current-voltage converter 102, an amplifier 103, and a comparator 104 as shown in FIG. explain.

In the receiving circuit 100, infrared light as an input signal is converted from an optical signal to an electric signal (current) by the photodiode 101. The current output from the photodiode 101 is converted into a voltage by the current-voltage converter 102 and amplified by the amplifier 103. Here, the voltage after being amplified by the amplifier 103 is expressed as a voltage V1. The comparator 104 compares the voltage V1 with a predetermined threshold value, and outputs the predetermined voltage Vo when the voltage V1 exceeds the threshold value.

In the encoding method disclosed in Patent Document 1 (Japanese Patent Application Laid-Open No. 2008-103898), encoded data in which a plurality of bits having a value of “1” may continue is generated. For example, it is assumed that encoded data “01001100” is generated by this encoding method and transmitted to the receiving circuit 100 as an input signal as shown in FIG.

At this time, if the receiving circuit 100 has poor high-frequency characteristics, or if the level difference between “1” and “0” of the received optical signal is extremely large because the installation distance to the transmitter is short, the encoded data Among them, the larger the number of consecutive bits having a value of “1”, the larger the amplitude of the voltage V1 (see FIG. 10B). When such a voltage V1 is applied to the comparator 104, if the threshold value of the comparator 104 is Th1 (see FIG. 10B), an output Vo1 as shown in FIG. 10C is obtained. On the other hand, when the threshold value of the comparator 104 is Th2 (see FIG. 10B), an output Vo2 as shown in FIG. 10D is obtained.

In the output Vo1, the voltage value of the portion corresponding to the portion (M1 in FIG. 10A) where the bit having the value “1” exists alone in the encoded data is 0 (FIG. 10 ( c)), the receiving circuit 100 may misrecognize a bit having a value of “1” as a bit having a value of “0”. On the other hand, in the output Vo2, from the transmission time t1 of the input signal corresponding to the portion (M2 in FIG. 10A) in which the bit having the value “1” continues in the encoded data, the output Vo2 in FIG. Since the output time t2 of the voltage Vo2 at the portion corresponding to M2 is longer (see FIG. 10D), the receiving circuit 100 misrecognizes a bit having a value of “0” as a bit having a value of “1”. there's a possibility that.

When such a misrecognition of the bit value occurs, the input signal needs to be retransmitted to the receiving circuit, and it may take time until the receiving circuit receives the correct encoded data.

An object of the present invention is an encoding device that encodes information data in accordance with a predetermined signal rule, and generates encoded data that is less likely to cause erroneous recognition of bit values regardless of conditions on the receiving circuit side. It is an object to provide an encoding device.

The encoding device according to the present invention includes conversion means. The converting means converts the 4-bit information data into N-bit (N ≧ 5) encoded data according to a predetermined coding rule. In the coding rule, bits having a value of “1” are not consecutive in the encoded data, and the number of bits having a value of “1” in the encoded data is 1 or 2, and the N is 7.

Here, 4-bit information data is converted into encoded data in which bits having a value of “1” are not consecutive. When such encoded data is transmitted from the transmitter, the amplitude of the output of the receiving circuit is always constant with respect to the input signal corresponding to the bit having a value of “1” regardless of the conditions on the receiving circuit side. Cheap. That is, the present encoding device can generate encoded data in which the receiving circuit is unlikely to erroneously recognize bit values regardless of the conditions on the receiving circuit side.

Also, here, since the number of bits having a value of “1” in 1 encoded data (7-bit encoded data) is 1 or 2, the duty ratio of the signal can be suppressed. As a result, the average output of the transmitter that transmits the encoded data can be suppressed. Further, since one encoded data always includes a bit having a value of “1”, a receiving circuit that receives a signal can easily synchronize.

Also, since the 4-bit information data is converted to 7-bit code data here, the time required for signal transmission is reduced compared to the case where 4-bit information data is converted to encoded data of 8 bits or more. It can be shortened.

In the encoding apparatus according to the present invention, 4-bit information data is converted into encoded data in which bits having a value of “1” are not consecutive. When such encoded data is transmitted from the transmitter, the amplitude of the output of the receiving circuit is always constant with respect to the input signal corresponding to the bit having a value of “1” regardless of the conditions on the receiving circuit side. Cheap. That is, the present encoding device can generate encoded data in which the receiving circuit is unlikely to erroneously recognize bit values regardless of the conditions on the receiving circuit side.

It is a figure which shows the electronic shelf label system in which the encoding apparatus which concerns on one Embodiment of this invention is used. It is a figure which shows the example of arrangement | positioning of the electronic shelf label used with the electronic shelf label system of FIG. It is a figure which shows the external appearance of the electronic shelf label used with the electronic shelf label system of FIG. It is a block diagram which shows schematic structure of the communication apparatus used with the electronic shelf label system of FIG. The communication device incorporates an encoding device according to an embodiment of the present invention. It is a block diagram which shows schematic structure of the communication part of the electronic shelf label used with the electronic shelf label system of FIG. The communication unit incorporates an encoding device according to an embodiment of the present invention. It is a figure which shows an example of the receiving circuit (light-receiving / reproducing part) of an infrared signal. It is an example of the code rule used with the encoding apparatus which concerns on one Embodiment of this invention. FIG. 8 is an example of encoded data reproduced by the receiving circuit (light receiving / reproducing unit) of FIG. 6 when the encoded data obtained using the encoding rule shown in FIG. 7 is transmitted as an infrared signal. FIG. 8A shows encoded data and an input signal (infrared signal) transmitted based on the encoded data. FIG. 8B shows a voltage V1 obtained by converting the infrared signal of FIG. 8A into an electrical signal by the photodiode of the receiving circuit and further amplifying it by the amplifier of the receiving circuit. FIG. 8C shows an output signal obtained by inputting the voltage V1 of FIG. 8B to the comparator. It is an example of the code rule used with the encoding apparatus which concerns on the modification B. Coding that is obtained by using a conventional coding rule and is reproduced by the receiving circuit (light receiving reproduction unit) in FIG. 6 when coded data having consecutive bits having a value of “1” is transmitted as an infrared signal. It is an example of data. FIG. 10A shows encoded data and an input signal (infrared signal) transmitted based on the encoded data. FIG. 10B shows a voltage V1 obtained by converting the infrared signal of FIG. 10A into an electrical signal by the photodiode of the receiving circuit and further amplifying it by the amplifier of the receiving circuit. FIG. 10C shows an output signal obtained by inputting the voltage V1 of FIG. 10B to the comparator. FIG. 10C shows an output signal when Th1 is used as the threshold value. FIG. 10D shows an output signal obtained by inputting the voltage V1 of FIG. 10B to the comparator. FIG. 10D shows an output signal when Th2 is used as the threshold value.

Hereinafter, an encoding apparatus 50 according to an embodiment of the present invention will be described with reference to the drawings.

Note that the encoding device 50 according to the present embodiment is merely an example of the encoding device of the present invention, and the encoding device according to the present invention is not limited to the contents described below. Other modes can be adopted as long as they do not contradict the gist of the invention.

(1) Overall Overview In the present embodiment, the encoding device 50 constitutes a part of the electronic shelf label system 1 shown in FIG. However, the present invention is not limited to this, and the encoding device 50 can be applied to various systems that require signal encoding.

(2) Overview of Electronic Shelf Label System The following is an overview of the electronic shelf label system 1 in which the encoding device 50 is used.

The electronic shelf label system 1 is used in stores such as supermarkets and convenience stores. The electronic shelf label system 1 displays the product information (the sales price of the product in this embodiment) managed by the electronic shelf label server 10 on the electronic shelf label 40 arranged corresponding to the product displayed on the sales floor. It is a system to do.

Note that the electronic shelf label 40 is a portable device, and is a display device arranged corresponding to each of a plurality of products P handled in the store. The electronic shelf label 40 is arranged in the vicinity of the corresponding product P among the plurality of types of products P displayed on the store floor of the store, and displays the product information regarding the corresponding product P on the display unit 41 described later ( 2 and 3). Each electronic shelf label 40 is given a unique ID (device ID) for identifying the electronic shelf label 40 and other electronic shelf labels 40.

As shown in FIG. 1, the electronic shelf label system 1 mainly includes an electronic shelf label server 10, a plurality of electronic shelf labels 40, 40,..., A plurality of

communication devices

30, 30,. It is composed of The number of electronic shelf labels 40 and communication devices 30 included in the electronic shelf label system 1 is not limited to the number shown in FIG. The communication device 30 and the electronic shelf label 40 include an encoding device 50 according to an embodiment of the present application (see FIGS. 4 and 5).

(2-1) Electronic Shelf Label Server The electronic shelf label server 10 is a computer that comprehensively controls the electronic shelf label system 1. The electronic shelf label server 10 is disposed, for example, in a store backyard.

The electronic shelf label server 10 stores product information displayed on the electronic shelf label 40 (here, numerical data of the sales price of the product P). The electronic shelf label server 10 transmits product information to the electronic shelf label 40 via the communication device 30 when the electronic shelf label system 1 is activated or when the display change of the electronic shelf label 40 is necessary. When the display change of the electronic shelf label 40 is necessary, for example, when the content of the product information stored in the electronic shelf label server 10 is updated or during the sale period of the product P, the price is changed from the normal selling price to the special price. This is when the price is changed to the selling price or when the price is changed from the special selling price to the normal selling price at the end of the special sale period of the product P.

The electronic shelf label server 10 stores the device ID of the electronic shelf label 40 and the product ID of the product P (the product ID attached to the product P with a barcode or the like) in association (linked). ing. When the product information of a product P is transmitted to the electronic shelf label 40 via the communication device 30, the device ID (product information of the product information) of the electronic shelf label 40 associated with the product P is displayed together with the product information. The device ID of the electronic shelf label 40 of the transmission destination) is transmitted as an identifier. The electronic shelf label 40 determines whether the transmitted product information has been transmitted to itself by comparing the transmitted identifier with its own device ID.

(2-2) Communication Device The communication device 30 is an infrared transceiver. The communication device 30 exchanges various signals with the electronic shelf label 40 using infrared rays. The communication device 30 is attached to a ceiling in a store, for example, with a certain interval. The installation location and the installation interval of the communication device 30 are determined so that the electronic shelf label 40 installed in the store can communicate with any one of the communication devices 30. The communication device 30 is connected to the electronic shelf label server 10 via a network 2 such as a LAN (Local Area Network).

The communication device 30 mainly includes an encoding device 50, a decoding device 60, a drive unit 31, an infrared light emitting element 32, and a light receiving / reproducing unit 33, as shown in FIG.

The encoding device 50 receives product information and an identifier transmitted as information data from the electronic shelf label server 10 and encodes them according to a coding rule described later. In other words, the encoding device 50 converts the information data transmitted from the electronic shelf label server 10 into encoded data according to a predetermined encoding rule. The encoding device 50 will be described in detail later.

The encoded data encoded by the encoding device 50 is output to the drive unit 31. The drive unit 31 drives the infrared light emitting element 32 based on the encoded data input from the encoding device 50. The infrared light emitting element 32 is, for example, an LED (Light Emitting Diode). The infrared light emitting element 32 is driven by the drive unit 31 and outputs an infrared signal modulated with encoded data. Specifically, the infrared light emitting element 32 is driven by the drive unit 31 and blinks at a predetermined frequency while the value of “1” is indicated in the encoded data. On the other hand, the infrared light emitting element 32 is turned off while the encoded data indicates a bit having a value of “0”.

The light receiving / reproducing unit 33 receives an infrared signal (for example, an ACK signal described later) transmitted from the electronic shelf label 40, and reproduces encoded data from the infrared signal. Specifically, the light receiving / reproducing unit 33 first converts the received infrared signal into an electrical signal. Next, the light receiving / reproducing unit 33 amplifies the electric signal. Further, the light receiving / reproducing unit 33 reproduces the encoded data based on the amplified electrical signal. For the light receiving / reproducing unit 33, for example, the receiving circuit 100 including the photodiode 101, the current-voltage converter 102, the amplifier 103, and the comparator 104 shown in FIG. 6 is used.

The encoded data reproduced by the light receiving / reproducing unit 33 is output to the decoding device 60. The decoding device 60 decodes the encoded data input from the light receiving / reproducing unit 33 (converts it into information data) and transmits it to the electronic shelf label server 10. The decryption device 60 will be described later.

(2-3) Electronic Shelf Label As described above, the electronic shelf label 40 is arranged corresponding to each of the plurality of products P handled in the store, and displays product information regarding the corresponding product P (see FIG. 2). ). The sales price of the product P is displayed on the electronic shelf label 40 as product information (see FIG. 3).

The electronic shelf label 40 is driven by a built-in battery (not shown). The electronic shelf label 40 includes, as main components, a display unit 41 on which product information is displayed, a communication unit 42 that communicates with the communication device 30, and a control unit 43 that controls each unit of the electronic shelf label 40. .

The display unit 41 is a segment type liquid crystal display. However, the present invention is not limited to this, and may be, for example, dot matrix electronic paper.

The communication unit 42 communicates with the communication device 30 using infrared rays. As shown in FIG. 5, the communication unit 42 mainly includes an encoding device 50, a decoding device 60, a driving unit 42a, an infrared light emitting element 42b, and a light receiving / reproducing unit 42c. Since the communication unit 42 has the same configuration as that of the communication device 30, the difference between the two is mainly described here, and a part of the description is omitted for the common points.

The light receiving and reproducing unit 42c receives the product information transmitted from the electronic shelf label server 10 via the communication device 30 and the identifier transmitted together with the product information in the form of an infrared signal. The light receiving / reproducing unit 42c reproduces the encoded data from the infrared signal in the same manner as the light receiving / reproducing unit 33 described above. The encoded data reproduced by the light receiving / reproducing unit 42 c is output to the decoding device 60. The decoding device 60 decodes the encoded data input from the light receiving / reproducing unit 42 c, converts it into information data, and transmits the information data to the control unit 43.

The encoding device 50 of the communication unit 42 encodes a signal (for example, an ACK signal described later) input from the control unit 43 according to a coding rule described later. The encoded data encoded by the encoding device 50 is output to the drive unit 42a. The drive unit 42a drives the infrared light emitting element 42b made of, for example, an LED based on the encoded data input from the encoding device 50. Since the drive part 42a and the infrared light emitting element 42b are the same as the drive part 31 and the infrared light emitting element 32 of the communication apparatus 30, description is abbreviate | omitted here.

The control unit 43 is mainly configured by a CPU. The control unit 43 controls each unit of the electronic shelf label 40 by executing a program stored in a storage unit (not shown).

The control unit 43 controls the communication unit 42 to receive infrared rays transmitted from the communication device 30 and causes the control unit 43 to transmit information data obtained by decoding the infrared data. When the information data is transmitted from the communication unit 42, the control unit 43 compares the identifier transmitted together with the product information from the electronic shelf label server 10 with the device ID stored in the storage unit. When the identifier and the device ID stored in the storage unit match, the control unit 43 determines that the product information addressed to itself (addressed to the electronic shelf label 40 to which the control unit 43 belongs) has been received. . When determining that the product information addressed to itself is received, the control unit 43 transmits a signal (ACK signal) notifying that the product information has been received to the communication unit 42. Further, the control unit 43 stores the product information addressed to itself received by the communication unit 42 in the storage unit. Furthermore, the control unit 43 controls the display unit 41 so that the product information stored in the storage unit is displayed on the display unit 41.

(3) Encoding Device and Decoding Device The encoding device 50 and the decoding device 60 will be described.

The encoding device 50 and the decoding device 60 are mainly composed of logic circuits. The encoding device 50 mainly includes an encoding unit 50a. The encoding unit 50a is an example of a conversion unit that converts 4-bit information data into encoded data of 5 bits or more according to a coding rule. The decoding device 60 mainly includes a decoding unit 60a. The decoding unit 60a converts the encoded data into 4-bit information data according to a decoding rule. Note that the coding rule and the decoding rule correspond to each other, and it is determined that original information data can be obtained by converting encoded data obtained by converting certain information data according to the coding rule according to the decoding rule.

FIG. 7 shows a coding rule used in the coding device 50. The encoding unit 50a uses the coding rule of FIG. 7 to convert the information data described on the left side of FIG. 7 into 7-bit encoded data described on the right side of FIG. The decoding rule corresponding to this coding rule is that the encoded data described on the right side in FIG. 7 is converted to 4-bit information data described on the left side in FIG. Omitted.

As can be seen from FIG. 7, there are mainly three features on this code side.

First, in the encoded data generated by this encoding rule (encoded data obtained by the encoding unit 50a converting the information data according to the encoding rule), bits having a value of “1” are continuous. There is no (see FIG. 7). Note that “bits having a value of“ 1 ”are not consecutive in encoded data” means that bits having a value of “1” are consecutive in one encoded data (7-bit encoded data). Not only does this mean, but also means that bits having a value of “1” do not continue between adjacent encoded data. The reason why the bit having a value of “1” does not continue between adjacent encoded data is that the last bit of the encoded data is always “0”.

Second, in the encoded data generated by this encoding rule, one or two bits having a value “1” are included in one encoded data (see FIG. 7).

Third, in this coding rule, 4-bit information data is converted into 7-bit encoded data (see FIG. 7).

The effects obtained by these features will be described below.

First, the effect obtained because the bit having the value “1” will not be continued will be described. Here, a case will be described as an example in which encoded data transmitted by infrared rays from the communication device 30 is received by the light receiving and reproducing unit 42c of the electronic shelf label 40. Here, it is assumed that the light receiving / reproducing unit 42c of the electronic shelf label 40 is the receiving circuit 100 shown in FIG.

In the receiving circuit 100, infrared light as an input signal is converted from an optical signal to an electric signal (current) by the photodiode 101. The current output from the photodiode 101 is converted into a voltage by the current-voltage converter 102 and amplified by the amplifier 103. The voltage after being amplified by the amplifier 103 is represented by a voltage V1. The comparator 104 compares the voltage V1 with a predetermined threshold value, and outputs an “H” level to the output voltage Vo when the voltage V1 exceeds the threshold value, and outputs an “L” level when the voltage V1 does not exceed the threshold value. Thereby, the encoded data is reproduced from the infrared signal.

First, a problem in the case where the light receiving / reproducing unit 42c receives data with consecutive bits having a value of “1” as an infrared signal will be described.

When receiving encoded data with consecutive bits having a value of “1” as an infrared signal, if the light receiving / reproducing unit 42c has poor high-frequency characteristics or has been subjected to specific conditions, As the number of consecutive bits having a value of “1” increases, the amplitude of the voltage V1 increases (see FIG. 10B). Conditions that affect the reception characteristics of the light receiving / reproducing unit 42c include, for example, the distance between the electronic shelf label 40 and the communication device 30 (more precisely, the distance between the light receiving / reproducing unit 42c and the communication device 30). For example, when the distance between the electronic shelf label 40 and the communication device 30 is short, the level difference between “1” and “0” of the optical signal received by the light receiving / reproducing unit 42c becomes extremely large, and the encoded data includes As the number of consecutive bits having a value of “1” increases, the amplitude of the voltage V1 may increase. When such a voltage V1 is applied to the comparator 104, if the threshold value of the comparator 104 is Th1 (see FIG. 10B), an output Vo1 as shown in FIG. 10C is obtained. On the other hand, when the threshold value of the comparator 104 is Th2 (see FIG. 10B), an output Vo2 as shown in FIG. 10D is obtained.

On the other hand, in the coding rule of FIG. 7 used by the encoding device 50, since the bits having the value “1” are not consecutive, the amplitude of the voltage V1 obtained corresponding to the bit having the value “1” as shown in FIG. Is constant. For this reason, the encoded data is unlikely to be reproduced erroneously regardless of the high frequency characteristics of the light receiving / reproducing unit 42c.

Next, an effect obtained because one or two bits having a value “1” in one encoded data will be described.

First, in 7-bit encoded data, there are only 2 bits whose value is “1” at the maximum, so the duty ratio (the ratio of the number of bits whose value is “1” to the total number of bits) is suppressed. can do. For example, the duty ratio is 25% in the quaternary PPM system (quaternary pulse position modulation (Pulse-Position Modulation) system), which is a generally known encoding system, and the duty ratio is 50 in the CMI (Coded Mark Inversion) system. %. On the other hand, when this code rule is used, the duty ratio can be reduced to about 20%. As a result, it is possible to suppress the average output of the communication unit 30 and the communication unit 42 of the electronic shelf label 40 when transmitting the encoded data.

In addition, since one encoded data always includes a bit having a value of “1”, the communication device 30 and the communication unit 42 of the electronic shelf label 40 may be synchronized with the encoded data. Easy.

Finally, the effect obtained by converting 4-bit information data into 7-bit encoded data will be described.

The quaternary PPM method and the CMI method have a feature that the number of bits of encoded data is twice that of information data. On the other hand, according to this coding rule, the number of bits of encoded data is only 1.75 times the number of bits of information data. Therefore, the time required for signal transmission can be shortened compared to the 4-value PPM method and the CMI method.

It should be noted that the effect obtained by not consecutive bits having a value of “1” and the effect obtained by the presence of one or two bits having a value of “1” in one encoded data, In obtaining the coding rule, the 4-bit information data may be converted into 8-bit or more encoded data. However, as described above, from the viewpoint of shortening the signal transmission time, it is desirable that the coding rule is to convert 4-bit information data into 7-bit encoded data.

(4) Features The encoding device 50 according to the present embodiment includes an encoding unit 50a. The converting means converts the 4-bit information data into N-bit (N ≧ 5) encoded data according to a predetermined coding rule. In the coding rule, bits having a value of “1” are not consecutive in the encoded data, and the number of bits having a value of “1” in the encoded data is 1 or 2, and the N is 7.

Here, 4-bit information data is converted into encoded data in which bits having a value of “1” are not consecutive. When such encoded data is transmitted from the communication device 30 or the communication unit 42 of the electronic shelf label 40, the conditions on the receiving circuit (the light receiving / reproducing unit 33 of the communication device 30 and the light receiving / reproducing unit 42 c of the communication unit 42) are satisfied. Regardless, the amplitude of the output of the receiving circuit with respect to an input signal corresponding to a bit having a value of “1” tends to be always constant. That is, the encoding device 50 can generate encoded data in which the receiving circuit is less likely to misrecognize the bit value regardless of the conditions on the receiving circuit side.

In addition, here, since the number of bits having a value of “1” in one encoded data is 1 or 2, the duty ratio of the signal can be suppressed low. As a result, the average output of the communication device 30 and the communication unit 42 that transmit the encoded data can be suppressed. Further, since one encoded data always includes a bit having a value of “1”, a receiving circuit that receives a signal can easily synchronize.

(5) Modification Examples of the present embodiment will be described below. Note that a plurality of modified examples may be combined as long as they do not contradict each other.

(5-1) Modification A
In the above embodiment, FIG. 7 is shown as an example of the coding rule, but the present invention is not limited to this. In FIG. 7, the correspondence between the information data and the encoded data can be arbitrarily rearranged. However, it is desirable that the correspondence between the information data and the encoded data is determined based on a rule (for example, a Gray code) that hardly causes an error.

(5-2) Modification B
In the above embodiment, FIG. 7 is shown as an example of the coding rule, but the present invention is not limited to this. For example, the coding rule may be as shown in FIG. Also in the coding rule of FIG. 9, the bits having the value “1” in the encoded data are not consecutive, and the number of bits having the value “1” in one encoded data is 1 or 2, and 4 bits. Are converted into 7-bit encoded data.

(5-3) Modification C
In the above-described embodiment, the encoding device 50 and the decoding device 60 are used for the communication unit 42 and the communication device 30 of the electronic shelf label 40 that perform communication using infrared rays, but are not limited thereto. . For example, the encoding device 50 and the decoding device 60 may be used for a communication unit and a communication device of an electronic shelf label that performs communication using radio waves.

(5-4) Modification D
In the above embodiment, encoded data in which bits having a value of “1” are continuous and encoded data in which the number of bits having a value of “1” is 3 or more are not particularly used. However, the present invention is not limited to this. . For example, encoded data with consecutive bits having a value of “1” and encoded data with 3 or more bits having a value of “1” are used for error detection purposes, receiver circuit synchronization, and communication control. May be used for the purpose.

The encoding apparatus according to the present invention is useful as an encoding apparatus that generates encoded data in which the receiving circuit is unlikely to cause erroneous recognition of bit values regardless of conditions on the receiving circuit side.

50 Coding device 50a Encoding unit (conversion means)

JP 2008-103898 A

Claims

Conversion means for converting 4-bit information data into N-bit (N ≧ 5) encoded data according to a predetermined encoding rule;
In the coding rule, bits having a value of “1” are not consecutive in the encoded data, and the number of bits having a value of “1” in the encoded data is 1 or 2, and N is 7 Is,
Encoding device.