WO2007055037A1

WO2007055037A1 - Interference judging device, data reader, rfid system, interference judging method and interference judging program

Info

Publication number: WO2007055037A1
Application number: PCT/JP2006/306463
Authority: WO
Inventors: Koji Nishikawa; Toshihisa Kamemaru; Hidetoshi Funakura
Original assignee: Mitsubishi Denki Kabushiki Kaisha
Priority date: 2005-11-08
Filing date: 2006-03-29
Publication date: 2007-05-18
Also published as: JPWO2007055037A1; KR100965973B1; WO2007055000A1; CN101292435A; KR20080054423A; TW200719609A; JP4589404B2

Abstract

An interference of radio waves between a data reader (100) and other data reader (100), and an interference of radio waves between the data reader (100) and an IC tag (200) are prevented, even when another new data reader (100) is arranged. An interference judging device is provided with a first comparing section (126) for judging whether there is an interference of radio waves between the data reader (100) and the data reader (100); a second comparing section (136) for judging whether there is an interference between the data reader (100) and the IC tag (200); and a judging section (140) for judging that another new data reader (100) can be arranged when the first comparing section (126) judges that there is no interference of radio waves between the data reader (100) and the data reader (100) and that the second comparing section (136) judges that there is no interference of radio waves between the data reader (100) and the IC tag (200).

Description

Specification

Interference determination device, data reader, RFID system, interference determination method, and interference determination program

Technical field

The present invention relates to a technique for preventing interference between a radio wave used in an RFID (Radio Frequency IDentification) system and a predetermined radio wave, for example.

Background art

Conventionally, automatic recognition (RFID) by non-contact data communication has been performed for individual management of articles and entrance / exit management. In the RFID system, an IC (Integrated Circuit) tag with a unique ID (identifier) is attached to an identification object such as an article or person. A data reader installed next to the gate or door supplies power to the IC tag using radio waves and sends a unique ID read command. The IC tag uses a radio wave from the data reader to drive the silicon chip built in the IC tag. The IC tag is stored in the IC tag, such as a unique ID, according to the command of the data reader, and the information that is stored in the IC tag responds depending on whether or not the unmodulated radio wave is reflected. return it. On the other hand, the data reader identifies the presence or absence of a reflected wave that is a response from the IC tag, and reads information stored in the IC tag such as a unique ID.

[0003] Since the data reader thus identifies the presence or absence of a weak reflected wave, when another data reader using the same frequency emits radio waves in the vicinity, Communication will be hindered. Therefore, the data reader checks whether another data reader using the same frequency in the vicinity emits radio waves before emitting radio waves. Here, this operation of the data reader is referred to as carrier sense. As a result of carrier sense, when it becomes clear that other data readers using the same frequency nearby do not emit radio waves, communication with the IC tag is started. On the other hand, when another data reader using the same frequency nearby emits radio waves! /, The frequency used is switched to another frequency, carrier sense is performed again, and the unused frequency is Communicate with IC tag using. Patent Document 1: Japanese Patent Laid-Open No. 10-293824

Disclosure of the invention

Problems to be solved by the invention

Conventionally, radio wave interference between a data reading device and another data reading device can be prevented by using conventional carrier sense. However, IC tags are assumed to be distributed globally. For this reason, IC tags are being developed mainly for the purpose of reducing power consumption for energy supply by radio waves and reducing manufacturing costs. Therefore, IC tags usually do not have steep frequency selectivity. Therefore, radio wave interference between the data reader and the IC tag was strong enough to prevent the radio wave interference even if the conventional carrier sense was used. In other words, if an IC tag communicating with a data reader with radio waves of a predetermined frequency is irradiated with radio waves of a different frequency, there is a problem that the IC tag malfunctions.

Embodiments of the present invention have been made to solve the above-described problems, and even when a data reading device is newly arranged in a location where the data reading device exists in the vicinity, the data reading is performed. The purpose is to prevent radio wave interference between the device and other data readers, and between the data reader and the IC tag.

Means for solving the problem

[0005] An interference determination device according to an embodiment of the present invention determines whether or not a radio wave used in an RFID system including an IC tag and a data reading device interferes with a predetermined radio wave. In the judgment device,

The specified frequency, which is the frequency of the specified radio wave, is specified by the input device, and the first threshold value, which is the threshold of the interference level of the specified frequency specified by the frequency specifying unit, is set and stored in the storage device. A first interference level setting unit; a first interference level detecting unit that detects a first detection value that is an interference level of the specified frequency; and stores the first detection value in a storage device; and a first threshold set by the first interference level setting unit. And the first detection value detected by the first interference level detection unit, and is assigned to the RFID system, a first comparison unit that determines whether or not the first detection value is less than or equal to the first threshold by the processing device. Set the second threshold that is the threshold of the interference level of the specified frequency band that is the frequency band that includes the specified frequency of multiple frequency bands. A second interference level setting unit for storing in the storage device, a second interference level detection unit for detecting a second detection value that is an interference level in the designated frequency band, and storing the second detection value in the storage device, and the second interference level setting unit. Comparing the second threshold value set by the second detection value detected by the second interference level detection unit and determining whether the second detection value is less than or equal to the second threshold value by the processing device; If the first comparison unit determines that the first detection value is less than or equal to the first threshold value and the second comparison unit determines that the second detection value is less than or equal to the second threshold value, radio waves interfere. And a determination unit that determines by the processing device.

[0006] In addition, the second interference level detection unit of the interference determination device detects the interference level of each channel of the plurality of channels assigned to the designated frequency band as a second detection value, and stores it in the storage device, The second comparison unit compares the second threshold value with each second detection value for each channel detected by the second interference level detection unit, and whether each second detection value for each channel is less than or equal to the second threshold value. The determination unit determines that the first comparison unit determines that the first detection value is less than or equal to the first threshold value, and the second comparison unit determines all the second detection values for each channel. If it is determined that it is less than or equal to the second threshold, it is determined that radio waves should not interfere.

[0007] Further, the second threshold set by the second interference level setting unit of the interference determination device is larger than the first threshold set by the first interference level setting unit.

[0008] Furthermore, the first interference level setting unit of the interference determination device sets a first threshold based on the magnitude of the output for transmitting the radio wave of the specified frequency, and the second interference level setting unit includes: The second threshold is set based on the magnitude of the output for transmitting the radio wave of the specified frequency.

[0009] In addition, the interference determination apparatus according to the embodiment of the present invention has a notification wave that is a notification radio wave when an IC tag and a communication wave that is a communication radio wave are transmitted to the IC tag. An interference determination device for determining whether or not a radio wave used in an RFID system and a predetermined radio wave interfere with each other. il /

A frequency designating unit that designates a designated frequency that is the frequency of the predetermined radio wave by an input device, and a first threshold that is a threshold of an interference level of the designated frequency designated by the frequency designating unit. A first interference level setting unit that sets a value and stores it in a storage device, a first interference level detection unit that detects and stores in a storage device a first detection value that is an interference level of the specified frequency, and the first interference The first threshold value set by the level setting unit and the first detection value detected by the first interference level detection unit are compared, and the processing device determines whether the first detection value is less than or equal to the first threshold value. A comparison unit; a notification channel interference level setting unit that sets a notification channel threshold value that is a threshold of a notification channel interference level and stores the notification channel threshold value; and a notification channel detection value that is a notification channel interference level is detected and stored in a storage device. The notification channel interference level detection unit stored in the notification channel, the notification channel threshold set by the notification channel interference level setting unit and the notification channel detection value detected by the notification channel interference level detection unit are compared, and A notification channel comparison unit that determines whether or not the channel detection value is equal to or less than a notification channel threshold, and the first comparison unit determines that the first detection value is equal to or less than the first threshold, and the notification When the channel comparison unit determines that the notification channel detection value is equal to or less than the notification channel threshold value, the channel comparison unit includes a determination unit that determines by the processing device that radio waves do not interfere.

[0010] Furthermore, the notification channel threshold set by the notification channel interference level setting unit of the interference determination device is larger than the first threshold set by the first interference level setting unit.

[0011] Further, the first interference level setting unit of the interference determination device sets a first threshold based on the magnitude of the output for transmitting the radio wave of the designated frequency, and the notification channel interference level setting unit is The notification channel threshold is set based on the magnitude of the output for transmitting the radio wave of the specified frequency.

[0012] Further, the interference determination device according to the embodiment of the present invention transmits an IC (Integrated Circuit) tag and a radio wave having a predetermined frequency to the IC tag, and the IC tag force has a frequency different from the predetermined frequency. RFID (Radio Frequency) equipped with a data reader that receives

(IDentification) Contact an interference judgment device that judges whether or not the radio wave used in the system interferes with the specified radio wave.

A frequency designating unit for designating a designated frequency, which is a frequency of the predetermined radio wave, by an input device, and a frequency including the designated frequency in a plurality of frequency bands assigned to the RFID system. A second interference level setting unit that sets a second threshold value that is a threshold value of an interference level of a designated frequency band that is a wave number band and stores the second threshold value in a storage device, and a second detection value that is an interference level of the designated frequency band is detected. The second interference level detection unit stored in the storage device, the second threshold set by the second interference level setting unit and the second detection value detected by the second interference level detection unit are compared, and the second When the second comparison unit determines whether the detected value is less than or equal to the second threshold by the processing device and the second comparison unit determines that the second detection value is equal to or less than the second threshold, the radio wave does not interfere. And a determination unit for determining by the processing device.

[0013] Further, the second interference level setting unit of the interference determination device is characterized in that the second threshold is set based on the magnitude of the output for transmitting the radio wave of the specified frequency.

[0014] Further, the interference determination device according to the embodiment of the present invention determines whether or not a radio wave used in an RFID system including an IC tag and a data reading device interferes with a predetermined radio wave. In the interference judgment device

The specified frequency, which is the frequency of the specified radio wave, is specified by the input device, and the first threshold value, which is the threshold of the interference level of the specified frequency specified by the frequency specifying unit, is set and stored in the storage device. A first interference level setting unit; a first interference level detecting unit that detects a first detection value that is an interference level of the specified frequency; and stores the first detection value in a storage device; and a first threshold set by the first interference level setting unit. Is compared with the first detection value detected by the first interference level detection unit, and a first comparison unit that determines whether the first detection value is less than or equal to the first threshold by the processing device and a predetermined frequency based on the specified frequency. The peripheral frequency interference level setting unit that sets a peripheral frequency threshold value that is a threshold value of the interference frequency of the peripheral frequency and stores it in the storage device, with a predetermined frequency in the range of the peripheral frequency, and the interference level of the peripheral frequency A certain lap A peripheral frequency interference level detection unit that detects a side frequency detection value and stores it in a storage device; a peripheral frequency threshold set by the peripheral frequency interference level setting unit; and a peripheral frequency detection value detected by the peripheral frequency interference level detection unit And the peripheral frequency comparison unit that determines whether the peripheral frequency detection value is less than or equal to the peripheral frequency threshold by the processing device and the first comparison unit determines that the first detection value is equal to or lower than the first threshold, And when the said surrounding frequency comparison part determines that a surrounding frequency detection value is below a surrounding frequency threshold value, it has a judgment part which judges with a processing apparatus that a wave does not interfere. [0015] Further, the peripheral frequency threshold set by the peripheral frequency interference level setting unit of the interference determination device is larger than the first threshold set by the first interference level setting unit.

[0016] Further, the peripheral frequency interference level setting unit of the interference determination device sets each frequency of a plurality of predetermined frequencies within the predetermined frequency power in a predetermined range as the peripheral frequency, and the peripheral frequency is the above As the distance from the designated frequency increases, the peripheral frequency threshold value is set to a larger value, the peripheral frequency interference level detection unit detects the peripheral frequency detection value of each of the predetermined frequencies, and the peripheral frequency comparison unit The peripheral frequency threshold is compared with the peripheral frequency detection value for each of a plurality of predetermined frequencies, and it is determined whether the peripheral frequency detection value is equal to or less than the peripheral frequency threshold. The first comparison unit determines that the first detection value is less than or equal to the first threshold value, and the peripheral frequency comparison unit detects the peripheral frequency for all the predetermined frequencies. Where it is determined that the boundary frequency threshold or less, the radio wave is characterized that you determine interference Do, and.

[0017] Furthermore, the data reading apparatus according to the embodiment of the present invention provides a command to the IC tag when the interference determination apparatus and the determination unit of the interference determination apparatus determine that radio waves do not interfere. And a receiving unit that receives a response to the command transmitted from the IC tag from the IC tag.

[0018] Further, an RFID system according to an embodiment of the present invention is an RFID system including the data reader and an IC tag.

The IC tag performs processing based on an IC tag receiving unit that receives a command transmitted from the transmitting unit of the data reading device by the communication device, and a command received by the IC tag receiving unit, and the processing result is transmitted from the communication device. And an IC tag transmitter for transmitting.

Further, the interference determination method according to the embodiment of the present invention determines whether or not a radio wave used in an RFID system including an IC tag and a data reading device interferes with a predetermined radio wave. The interference judgment method of the interference judgment device

A frequency designation step in which the frequency designation unit designates a designated frequency, which is a frequency of the predetermined radio wave, by an input device, and a specification frequency designated in the frequency designation step. A first interference level setting step in which the first interference level setting unit sets a first threshold that is a threshold for the interference level and stores it in the storage device; and a first detection value that is the interference level of the specified frequency is the first interference level. A first interference level detection step detected by the detection unit and stored in the storage device; a first threshold set in the first interference level setting step; and a first detection value detected in the first interference level detection step. (1) The first comparison step in which the comparison unit compares and the first detection value is determined by the processing device to determine whether or not the first detection value is equal to or less than the first threshold, and the above designation of a plurality of frequency bands assigned to the RFID system. A second interference level setting step in which a second threshold value is set by the second interference level setting unit and stored in the storage device, and the interference in the specified frequency band is set. Is level 2Detected by the second interference level detection step in which the second interference level detection unit detects the detected value and stores it in the storage device, the second threshold set in the second interference level setting step, and the second interference level detection step. The second comparison unit compares the second detection value, and the second comparison unit determines whether or not the second detection value is equal to or less than the second threshold by the processing device; and the first comparison step If the first detection value is determined to be less than or equal to the first threshold value and the second comparison value is determined to be less than or equal to the second threshold value in the second comparison step, the radio wave does not interfere! And a determination step of determining by the processing device.

Furthermore, the interference determination program according to the embodiment of the present invention is an interference determination program for determining whether or not a radio wave used in an RFID system including an IC tag and a data reader interferes with a predetermined radio wave. In the interference judgment program of the judgment device,

The frequency designating unit designates the designated frequency, which is the frequency of the predetermined radio wave, by the input device, and the first threshold value which is the threshold value of the interference level of the designated frequency designated in the frequency designating step is the first interference. A first interference level setting step which is set by the level setting unit and stored in the storage device; and a first interference level which is detected by the first interference level detection unit and stored in the storage device, which is the interference level of the designated frequency. In the level detection step, the first comparison unit compares the first threshold value set in the first interference level setting step and the first detection value detected in the first interference level detection step, and the first detection value is 1st comparison step in which the first comparison unit determines whether or not the force is less than or equal to a threshold by the processing device, and a specified frequency that is a frequency band including the specified frequencies of a plurality of frequency bands assigned to the RFID system A second interference level setting step in which the second interference level setting unit sets a second threshold that is a threshold of interference levels in several bands and stores it in the storage device; and a second detection value that is the interference level in the designated frequency band (2) The second interference level detection step detected by the interference level detection unit and stored in the storage device, the second threshold value set in the second interference level setting step, and the second detection value detected in the second interference level detection step The second comparison unit compares the second detection value and the second comparison unit determines whether the second detection value is less than or equal to the second threshold by the processing device, and the first detection value in the first comparison step. Is determined to be less than or equal to the first threshold, and the second comparison step determines that the second detected value is less than or equal to the second threshold, the radio wave does not interfere! The computer to execute the determination step And wherein the door.

The invention's effect

[0021] According to the interference determination device according to the embodiment of the present invention, the first comparison unit determines the presence or absence of radio wave interference between the data reading device and the data reading device, and the second comparison unit determines the data. It is possible to determine the presence or absence of radio wave interference between the data reader and the IC tag. Therefore, it is possible to prevent radio wave interference between the data reader and another data reader and radio wave interference between the data reader and the IC tag.

BEST MODE FOR CARRYING OUT THE INVENTION

First, a hardware configuration of the data reading apparatus 100 that works on the embodiment will be described with reference to FIG. FIG. 1 is a diagram illustrating an example of a hardware configuration of the data reading apparatus 100 according to the embodiment.

In FIG. 1, a data reading apparatus 100 includes a CPU (Central Processing Unit) 911 that executes a program. The CPU 911 is connected to the ROM 913, the RAM 914, the communication board 915, the LCD (liquid crystal display) 901, the touch panel 902, the FDD (Flexible Disk) 904, the CDD 905, and the magnetic disk device 920 via the node 912. A CPU or the like is an example of a processing apparatus 980.

The RAM 914 is an example of a volatile memory. The ROM 913 and the magnetic disk device 920 are examples of non-volatile memory. These are examples of the storage device 984.

The communication board 915 is connected to a wireless antenna, LAN 942, and the like. Communication board 915 A wireless antenna or the like is an example of the communication device 986.

The touch panel 902 and the like are examples of the input device 982.

Here, the communication board 915 is not limited to the LAN 942, and may be directly connected to the Internet 940 or a WAN (Wide Area Network) such as ISDN. When directly connected to a WAN such as the Internet 940 or ISDN, the data reader 100 is connected to the Internet 940 or a WAN such as ISDN, and the gateway 941 is unnecessary.

The magnetic disk device 920 stores an operating system (OS) 921, a window system 922, a program group 923, and a file group 924. The program group 923 is executed by the CPU 911, the OS 921, and the window system 922.

[0024] The program group 923 stores a program for executing a function described as "-unit" in the description of the embodiment described below. The program is read and executed by CPU911.

In the file group 924, what is described as “to determination” and “to determination” in the description of the embodiment described below is stored as “to file”.

In addition, the arrow portion of the flowchart described in the description of the embodiment described below mainly indicates input / output of data, and for the input / output of the data, the data is the magnetic disk device 920, FD, optical disk, CD, It is recorded on other recording media such as MD (mini disk) and DVD (Digital Ver satile Disk). Alternatively, it is transmitted through signal lines and other transmission media.

In addition, what is described as “˜unit” in the description of the embodiment described below may be realized by firmware stored in the ROM 913. Alternatively, it may be implemented by software alone, hardware alone, a combination of software and hardware, or a combination of firmware.

[0026] In addition, a program for carrying out the embodiment described below may also be stored using a recording device using another recording medium such as a magnetic disk device 920, FD, optical disk, CD, MD, or DVD. I do not care.

Embodiment 1. Next, Embodiment 1 will be described. In the first embodiment, a data reading apparatus 100 that prevents radio wave interference between the data reading apparatus 100 and another data reading apparatus 100 and radio wave interference between the data reading apparatus 100 and the IC tag 200 will be described. . Here, among the functions of the data reader 100, radio wave interference between the data reader 100 and another data reader 100, and radio wave interference between the data reader 100 and the IC tag 200 occur. The part that determines whether or not the force is applied is an interference determination device.

First, the function of the RFID system 300 including the data reading device 100 and the IC tag 200 according to the first embodiment will be described with reference to FIG. FIG. 2 is a functional block diagram showing functions of the RFID system 300 including the data reading device 100 and the IC tag 200 according to the first embodiment.

[0029] The data reader 100 includes a frequency designation unit 110, a first determination unit 120, a second determination unit 130, a determination unit 140, a transmission unit 150, a reception unit 160, a processing device 980, an input device 982, and a storage device 984. The communication device 986 is provided.

[0030] Frequency designation unit 110 designates a designated frequency, which is a frequency of a predetermined radio wave, which is determined by the interference determination device to determine whether or not the radio wave used in RFID system 300 interferes with radio wave, using input device 982. That is, the interference determination device determines whether or not the radio wave used in the RFID system 300 interferes with the specified frequency. Here, the designated frequency is a frequency that the data reading apparatus 100 tries to use.

[0031] The first determination unit 120 performs high-accuracy carrier sense on the designated frequency designated by the frequency designation unit 110. The reason why the carrier sense is performed with high accuracy is, for example, to determine whether or not there is a force that causes radio wave interference between the data reader 100 and another data reader 100. The first determination unit 120 includes a first interference level setting unit 122, a first interference level detection unit 124, and a first comparison unit 126.

The first interference level setting unit 122 sets a first threshold value, which is an interference level threshold value of the designated frequency designated by the frequency designation unit 110, and stores it in the storage device 984.

The first interference level detection unit 124 detects the first detection value that is the interference level of the designated frequency designated by the frequency designation unit 110 and stores it in the storage device 984. For example, the first interference level detection unit 124 detects the first detection value by detecting the intensity of the radio wave of the specified frequency. The

The first comparison unit 126 compares the first threshold value set by the first interference level setting unit 122 and the first detection value detected by the first interference level detection unit 124, and the first detection value is the first threshold value. The processing device 980 determines whether or not the following is true.

That is, for example, when the first comparison unit 126 determines that the first detection value is equal to or less than the first threshold value, the first determination unit 120 generates a radio wave between the data reading device 100 and another data reading device 100. It is determined that no interference occurs.

The second determination unit 130 performs coarse carrier sense on the frequency band assigned to the RFID system 300 including the specified frequency specified by the frequency specifying unit 110. The reason why coarse sense is performed is, for example, to determine whether or not there is a force that causes radio wave interference between the data reader 100 and the IC tag 200. Here, the frequency band assigned to the RFID system 300 is a frequency band assigned to the RFID system 300 such as a 125 kHz band, a 13.56 MHz band, an 80θΖ900Ζζ band, and a 2.45 GHz band. The frequency band allocated to the RFID system 300 including the specified frequency is a frequency band including the specified frequency among the above frequency bands. The second determination unit 130 includes a second interference level setting unit 132, a second interference level detection unit 134, and a second comparison unit 136.

The second interference level setting unit 132 sets a second threshold that is a threshold of an interference level of a designated frequency band that is a frequency band including the designated frequencies of a plurality of frequency bands assigned to the RFID system 300, and stores the second threshold in the storage device 984. To do. Here, normally, the first determination unit 120 performs high-accuracy carrier sense, and the second determination unit 130 performs coarse-accuracy carrier sense. Therefore, the second threshold value is larger than the first threshold value.

The second interference level detection unit 134 stores the second detection value, which is the interference level in the designated frequency band, in the detection storage device 984.

The second comparison unit 136 compares the second threshold value set by the second interference level setting unit 132 with the second detection value detected by the second interference level detection unit 134, and the second detection value is the second threshold value. The processing device 980 determines whether or not the following is true.

That is, for example, when the second comparison unit 136 determines that the second detection value is equal to or less than the second threshold, the second determination unit 130 generates radio wave interference between the data reader 100 and the IC tag 200. Judge that not.

[0033] The determination unit 140 determines that the first comparison unit 126 determines that the first detection value is less than or equal to the first threshold value, and the second comparison unit 136 determines that the second detection value is less than or equal to the second threshold value. In this case, the processor 980 determines that the radio wave does not interfere. Here, radio waves do not interfere with radio waves between the data reader 100 and other data readers 100, and radio waves between the data reader 100 and the IC tag 200 do not interfere. That's what it means.

When the determination unit 140 determines that the radio wave does not interfere, the transmission unit 150 transmits a command to the IC tag by the communication device 986. That is, the transmitter 150 does not interfere with radio waves between the data reader 100 and other data readers 100, and does not interfere with radio waves between the data reader 100 and the IC tag 200. Send command to tag via communication device 986. Further, the transmission unit 150 transmits not only a command but also an unmodulated wave or the like.

[0035] Receiving section 160 receives a response to the command transmitted from transmitting section 150 from the IC tag.

The IC tag 200 includes an IC tag receiver 210 and an IC tag transmitter 220.

The IC tag receiving unit 210 receives the command transmitted from the transmitting unit 150 of the data reading device 100 by the communication device 986.

The IC tag transmission unit 220 performs processing based on the command received by the IC tag reception unit 210 and transmits the processing result by the communication device 986.

Next, the interference level of the channel assigned to each frequency at a certain time will be described based on FIG. 3 and FIG. FIG. 3 is a diagram showing the interference level (a) 410 of the channel assigned to each frequency at a certain time. FIG. 4 is a diagram showing the interference level (b) 420 of the channel assigned to each frequency at a certain time. In FIG. 3 and FIG. 4, “CH-1” represents channel 1, “CH-2” represents channel 2, and “CH—” is interchanged with channel in the same manner. Here, it is assumed that each frequency in a certain frequency band assigned to the RFID system 300 is assigned to channel 1 to channel 9. In each of the interference level (a) 410 and the interference level (b) 420, the first interference level is set as the first threshold value, and the second interference level is set as the second threshold value.

[0038] At interference level (a) 410, channel 3, channel 6, channel 8, and channel 9 are One threshold or less. At interference level (a) 410, channel 1, channel 2, channel 4, and channel 7 are below the second threshold. Also, at interference level (a) 410, channel 5 is greater than the second threshold, which is greater than the first threshold.

[0039] In interference level (b) 420, channel 3, channel 6, channel 8, and channel 9 are below the first threshold. At interference level (b) 420, channel 1, channel 2, channel 4, channel 5, and channel 7 are below the second threshold. Also, at interference level (b) 420, there is no channel greater than the second threshold that is greater than the first threshold.

Next, the operation of the RFID system 300 including the data reading device 100 and the IC tag 200 according to the first embodiment will be described with reference to FIG. FIG. 5 is a flowchart illustrating an interference determination method that is an operation of the RFID system 300 including the data reader 100 and the IC tag 200 according to the first embodiment.

In the first interference level setting step and the second interference level setting step (S 101), the first interference level setting unit 122 is the first threshold value that is the interference level of the specified frequency specified by the frequency specifying unit 110. A threshold value is set and stored in the storage device 984. The second interference level setting unit 1 32 sets and stores a second threshold value that is a threshold value of an interference level in a designated frequency band that is a frequency band including designated frequencies in a plurality of frequency bands assigned to the RFID system 300. Store in device 984. For example, the first interference level setting step and the second interference level setting step may be performed only when the data reader 100 is activated, or may be performed after the frequency specifying step (S102) described later. Ok! /.

[0042] In the frequency specifying step (S102), the frequency specifying unit 110 is a specified frequency that is a frequency of a predetermined radio wave that is determined by the interference determination device to determine whether or not the radio wave used in the RFID system 300 interferes with the radio wave. Is specified by the input device 982. For example, the frequency designation unit 110 may designate a channel assigned to the frequency as the designated frequency.

[0043] In the first interference level detection step (S103), the first interference level detection unit 124 detects the first detection value that is the interference level of the designated frequency designated by the frequency designation unit 110, and stores it in the storage device 984. To do.

[0044] In the first comparison step (S104), the first comparison unit 126 compares the first threshold value set by the first interference level setting unit 122 and the first detection value detected by the first interference level detection unit 124. And second 1 The processor 980 determines whether the detected value is less than or equal to the first threshold value. If the first detection value is equal to or smaller than the first threshold value (YES in S104), the data reading apparatus 100 proceeds to the standby step (S105). On the other hand, when the first detection value is not less than or equal to the first threshold value (NO in S104), the data reading device 100 proceeds to the frequency changing step (S113). That is, the first determination unit 120, for example, when the first comparison unit 126 determines that the first detection value is equal to or less than the first threshold (YES in S104), the first determination unit 120 is connected to another data reading device 100. It is determined that radio wave interference does not occur. Then, the data reading apparatus 100 proceeds to the standby step (S105) which is the next process. On the other hand, the first determination unit 120, for example, when the first comparison unit 126 determines that the first detection value is not less than or equal to the first threshold value (NO in S104), radio wave interference with other data reading devices 100 Is determined to occur. Then, the data reading apparatus 100 proceeds to the frequency changing step (S113), changes the specified frequency, and performs a process for determining whether or not the radio wave interferes again. That is, the data reading apparatus 100 changes the designated frequency and repeats the determination process as to whether or not the radio wave interferes until a frequency that does not cause radio wave interference with another data reading apparatus 100 is found. By this processing, the data reading apparatus 100 avoids radio wave interference with other data reading apparatuses 100. The frequency changing step (S113) will be described later.

In the standby step (S105), the data reading device 100 waits for execution of processing for a predetermined time. This process requires a certain amount of time for carrier sense, and even if it detects a channel that is V ヽ that is used first (no radio interference occurs), the channel must be used immediately. I can't do it.

In the second interference level detection step (S 106), the second interference level detection unit 134 detects the second detection value that is the interference level in the designated frequency band and stores it in the storage device 984.

In the second comparison step and the determination step (S 107), the second comparison unit 136 uses the second threshold set by the second interference level setting unit 132 and the second detection detected by the second interference level detection unit 134. The processing device 980 determines whether or not the second detection value is equal to or less than the second threshold value. When the second detection value is equal to or smaller than the second threshold (YES in S107), the data reading apparatus 100 performs the first interference level detection step (S108). On the other hand, when the second detection value is not less than or equal to the second threshold value (NO in S107), the data reading apparatus 100 proceeds to the frequency changing step (S113). That is, for example, the second determination unit 130 determines that the second comparison unit 136 sets the second detection value to be equal to or less than the second threshold value. If it is determined that there is (YES in S107), the data reading apparatus 100 determines that radio wave interference between the data reading apparatus 100 and the IC tag 200 does not occur. In this case, the determination unit 140 determines that the first comparison unit 126 determines that the first detection value is less than or equal to the first threshold value, and the second comparison unit 136 determines that the second detection value is less than or equal to the second threshold value. Since the determination is made, the processor 980 determines that the radio wave does not interfere. Then, the data reader 100 proceeds to the first interference level detection step (S108) which is the next process. On the other hand, the second determination unit 130, for example, when the second comparison unit 136 determines that the second detection value is not equal to or less than the second threshold (NO in S107), the radio wave between the data reader 100 and the IC tag 200 It is determined that interference occurs. In this case, the determination unit 140 determines that the radio wave interferes with the processing device 980. Then, the data reading apparatus 100 proceeds to the frequency changing step (S113), changes the designated frequency, and again performs a determination processing power for determining whether or not the radio waves interfere with other data reading apparatuses 100. In other words, the data reader 100 is designated until it finds a frequency that does not cause radio wave interference with other data readers 100 and between the data reader 100 and the IC tag 200. Change the frequency and repeat the process of determining whether radio waves interfere. By this processing, the data reading device 100 avoids radio wave interference between the other data reading devices 100 and radio wave interference between the data reading device 100 and the IC tag 200.

In the first interference level detection step (S 108), as in the first interference level detection step (S 103), the first interference level detection unit 124 uses the interference level of the designated frequency designated by the frequency designation unit 110. A first detection value is detected and stored in the storage device 984.

[0049] In the first comparison step (S109), as in the first comparison step (S104), the first comparison unit 126 uses the first threshold set by the first interference level setting unit 122 and the first interference level detection unit 124. Is compared with the first detected value, and the processor 980 determines whether or not the first detected value is less than or equal to the first threshold value. If the first detection value is less than or equal to the first threshold (YES in S109), the data reading apparatus 100 proceeds to the command issuing step (S110). On the other hand, when the first detection value is not less than or equal to the first threshold value (NO in S109), data reader 100 proceeds to the frequency changing step (S113).

Similar to the standby step (S105), this process requires a predetermined time for carrier sense, and even if a channel that is not used at the beginning (no radio wave interference) is detected, Do that because you cannot use that channel. That is, the data reader 100 is

After the specified time has elapsed, confirm again that the channel assigned to the specified frequency is not being used.

[0050] In the command issuing step (S110), the determination unit 140 determines that the radio wave does not interfere, and further confirms that the channel assigned to the specified frequency is not used even after a predetermined time has elapsed. When it is removed, the transmission unit 150 transmits a command to the IC tag 200.

[0051] In the response receiving step (S111), the receiving unit 160 receives a response to the command transmitted by the transmitting unit 150 from the IC tag.

Here, the IC tag receiving unit 210 of the IC tag 200 receives the command transmitted by the transmitting unit 150. Then, processing is performed based on the command received by the IC tag receiving unit 210, and the processing result is transmitted by the communication device 986. The receiving unit 160 receives this response.

[0052] In the termination determination step (S112), the data reader 100 issues a command again depending on whether or not the response from the IC tag 200 has been received or whether or not a predetermined time has passed. It is determined whether to end the process.

In the frequency changing step (S 113), the frequency specifying unit 110 changes the specified frequency. In this case, the frequency designation unit 110 clears the designated frequency, and performs the processing from the frequency designation step (S102) again.

Next, an example of the operation of the RFID system 300 including the data reader 100 and the IC tag 200 according to the first embodiment will be described based on FIGS. 3, 4, and 5. FIG.

First, it is assumed that the interference level of the channel assigned to each frequency is in the state of interference level (a) 410 shown in FIG. First, in the first interference level setting step and the second interference level setting step (S101), it is assumed that the first interference level setting unit 122 sets the first threshold value to the first interference level shown in FIGS. . Further, it is assumed that second interference level setting section 132 sets the second threshold value to the second interference level shown in FIGS.

Next, in the frequency designation step (S102), it is assumed that the frequency designation unit 110 designates channel 1. Next, in the first interference level detection step (S103), the first interference level detection unit 124 detects the interference level of channel 1. In the first comparison step (S104), the first comparison unit 126 determines that the first detection value is not less than or equal to the first threshold value (NO in S104). That is, the first comparison unit 126 determines that the other data reading device 100 is using the channel 1. That is, when channel 1 is used, first comparison unit 126 determines that radio wave interference occurs with other nearby data reading devices 100.

Therefore, next, in the frequency changing step (S113), the frequency specifying unit 110 clears channel 1 which is the specified frequency. Next, in the frequency designation step (S102), the frequency designation unit 110 designates the designated frequency again. Here, it is assumed that frequency specifying section 110 has set channel 2. Then, the data reading apparatus 100 performs the first interference level detection step (S103) and the first comparison step (S104) again. In the first comparison step (S104), the first comparison unit 126 determines that another data reader 100 in the vicinity is using the channel 2.

Therefore, the data reading apparatus 100 performs a frequency changing step (S113) and a frequency specifying step (S102). In the frequency designation step (S102), it is assumed that the frequency designation unit 110 designates channel 3 as the designated frequency. Then, the data reading apparatus 100 performs the first interference level detection step (S 103) and the first comparison step (S 104) again. In the first comparison step (S104), the first comparison unit 126 determines that the first detection value is not more than the first threshold value (YES in S104). That is, the first comparison unit 126 determines that another data reading device 100 in the vicinity uses the channel 3.

Therefore, next, in the standby step (S 105), the data reading apparatus 100 waits for execution of a predetermined time process. Next, in the second interference level detection step (S106), the second interference level detection unit 134 detects the interference level of the frequency band including the channel 3 that is the designated frequency. In other words, here, second interference level detection section 134 detects the interference level from channel 1 to channel 9, which is the frequency band in which channel 3 is included. Here, it is assumed that the interference levels from channel 1 to channel 9 are in the state of interference level (a) 410 shown in FIG. In the second comparison step (S107), the second comparison unit 136 determines that the second detection value is not less than or equal to the second threshold value (NO in S107) because channel 5 is greater than the second threshold value. That is, the second comparison unit 136 determines that the use of the channel 3 affects the IC tag 200 in communication with the other data reading device 100. That is, the second comparison unit 136 determines that radio wave interference with the IC tag 200 occurs. Therefore, next, in the frequency changing step (S113), the frequency specifying unit 110 clears channel 3 that is the specified frequency. Next, in the frequency designation step (S102), the frequency designation unit 110 designates the designated frequency again. Then, the data reading apparatus 100 performs the first interference level detection step (S103) and the first comparison step (S104) again. As a result of repeating the above processing (S 113 to S 104), in the first comparison step (S 104), the first comparison unit 126 uses the channel 6 for other data reading devices 100 in the vicinity. Judged.

Next, in the waiting step (S 105), the data reading apparatus 100 waits for execution of processing for a predetermined time. Then, in the second interference level detection step (S 106), the second interference level detection unit 134 detects the interference levels from channel 1 to channel 9. Here, it is assumed that the interference levels from channel 1 to channel 9 are in the state of interference level (b) 420 shown in FIG. In the second comparison step (S107), the second comparison unit 136 determines that the second detection value is less than or equal to the second threshold because all the interference levels up to the channel 1 power channel 9 are less than or equal to the second threshold (in S107). YES) In other words, the second comparison unit 136 uses the channel 6 to determine that the IC tag 200 in communication with the other data reading apparatus 100 is not affected. That is, the second comparison unit 136 determines that there is no radio wave interference with the IC tag 200. Therefore, the determination unit 140 determines that radio waves do not interfere.

[0059] Therefore, next, the data reading apparatus 100 performs the first interference level detection step (S108) and the first comparison step (S109), and the channel 6 is in the vicinity of the vicinity even after a predetermined time has elapsed. Make sure that the data reader 100 is using channel 6. That is, the data reading apparatus 100 confirms that no radio wave interference occurs with other data reading apparatuses 100 in the vicinity even if the channel 6 is used after a predetermined time has elapsed.

[0060] If the confirmation is obtained (YES in S109), the data reading apparatus 100 executes the command issuing step.

(S110), response reception step (S111), and end determination step (S112) are performed.

[0061] According to the data reader 100 and the RFID system 300 according to the first embodiment, even when a plurality of data readers 100 are arranged in the vicinity, the data reader 100 and the other data readers 100 are not It is possible to prevent radio wave interference and radio wave interference between the data reader 100 and the IC tag 200. Therefore, according to the data reading apparatus 100 and the RFID system 300 according to the first embodiment, the data reading apparatus 100 can perform stable communication with the IC tag 200.

In the above, when the second comparison unit 136 determines in the second comparison step (S107) that the second detection value is not less than or equal to the second threshold (NO in S107), the data reader 100 changes the frequency. Proceeding to step (S113), frequency designation unit 110 changes the designated frequency. However, the data reading apparatus 100 is not limited to this, and may wait for a predetermined time before proceeding to the second interference level detection step (S106)! /.

[0063] Also, the second interference level detector 134 detects the interference level of each channel of the plurality of channels assigned to the designated frequency band as the second detection value, stores it in the storage device 984, and stores it in the second device. The comparison unit 136 compares the second threshold value with the second detection value for each channel detected by the second interference level detection unit 134, and each second detection value for each channel is less than or equal to the second threshold value. The determination unit 140 determines that the first comparison unit 126 determines that the first detection value is less than or equal to the first threshold value, and the second comparison unit 136 determines all the second detection values for each channel. If it is determined that it is less than or equal to 2 thresholds, it may be determined that radio waves do not interfere.

[0064] Furthermore, the first interference level setting unit 122 sets the first threshold based on the magnitude of the output for transmitting the radio wave of the specified frequency, and the second interference level setting unit 132 transmits the radio wave of the specified frequency. The second threshold may be set based on the magnitude of the output to be output.

The first interference level setting unit 122 and the second interference level setting unit 132 may change the first threshold value and the second threshold value, respectively, when the magnitude of the output for transmitting the radio wave of the specified frequency is changed. I do not care.

When the output for transmitting radio waves at the specified frequency is low, compared to when the output for transmitting radio waves at the specified frequency is high, radio wave interference with other data readers 100 and IC tags 200 occurs. Become. Therefore, since the first interference level setting unit 122 and the second interference level setting unit 1 32 set the first threshold value and the second threshold value based on the magnitude of the output for transmitting the radio wave of the specified frequency, the data reader 100 Radio wave emission can be efficiently performed, and wireless communication between the data reader 100 and the IC tag 200 can be performed efficiently.

[0065] The RFID system according to the first embodiment is summarized as follows. The command analysis unit that demodulates the received command and analyzes the command, the memory control unit that reads or writes the memory, the data read from the memory and the analysis result of the command analysis unit An IC tag having a command execution unit to perform, a transmission means for transmitting data read from the memory, and

An RFID system including the IC tag and a data reading device that performs non-contact data communication, wherein the RFID system includes the following means.

The data reader (a) a transmitter that transmits a command or a non-modulated wave to the IC tag (b) a receiver that receives a response of the IC tag power (c) sets the interference level of the frequency to be used First interference level setting means (d) Second interference level setting means for setting the interference level of the frequency band allocated to the RFID system including the frequency to be used that is larger than the interference level set by the first interference level setting means (e) First interference level detection means for detecting the interference level of the used frequency (f) Second interference level detection means for detecting the interference level of the frequency band assigned to the RFID system including the used frequency (g) The interference level detected by the first interference level detection means is equal to or lower than the interference level set by the first interference level setting means, and the interference level detected by the second interference level detection means. But, When the interference level is below that set by the second interference level setting means includes a control unit which controls transmission of commands or unmodulated wave from the front Symbol transmitting unit.

[0066] Further, the data reading device includes: (a) a transmission output control unit that makes a transmission output variable (b) first interference level setting means that can change an interference level of a frequency to be used by a transmission output (c) Second interference level setting means is provided for setting the interference level of the frequency band or the notification dedicated channel according to the transmission output.

[0067] Embodiment 2.

Next, Embodiment 2 will be described. In the second embodiment, when a communication wave that is a communication radio wave for sending a command or the like to the IC tag 200 is transmitted, a notification channel that is a notification radio wave is assigned to a predetermined frequency. A data reading device 100 to be transmitted to and an RFID system 300 including the data reading device 100 will be described.

First, the data reading device 100 and the IC tag 200 according to the second embodiment are provided based on FIG. The functions of the RFID system 300 will be described. FIG. 6 is a functional block diagram showing functions of the RFID system 300 including the data reader 100 and the IC tag 200 according to the second embodiment. Here, only functions different from those of the RFID system 300 according to the first embodiment will be described.

The data reading apparatus 100 according to the second embodiment includes a notification channel determination unit 170 instead of the second determination unit 130.

Notification channel determination section 170 performs coarse carrier sense on the notification channel. The reason why the coarse carrier sense is performed is, for example, to determine whether or not radio wave interference occurs between the data reader 100 and the IC tag 200. In other words, the notification channel determination unit 170 performs power sense on the notification channel through which the notification wave is transmitted, thereby determining the power / force / intensity that affects the IC tag 200 in communication with the other data reader 100. To do. The notification channel determination unit 170 includes a notification channel interference level setting unit 172, a notification channel interference level detection unit 174, and a notification channel comparison unit 176.

The notification channel interference level setting unit 172 sets a notification channel threshold that is a threshold of the interference level of the notification channel and stores it in the storage device 984. Here, normally, the first determination unit 120 performs high-accuracy carrier sensing, and the notification channel determination unit 170 performs coarse-accuracy carrier sensing. Therefore, the notification channel threshold is larger than the first threshold.

Notification channel interference level detection section 174 detects the notification channel detection value that is the interference level of the notification channel and stores it in storage device 984.

The notification channel comparison unit 176 compares the notification channel threshold set by the notification channel interference level setting unit 172 with the notification channel detection value detected by the notification channel interference level detection unit 174, and the notification channel detection value is equal to or less than the notification channel threshold. The processor 980 determines whether or not there is any.

In other words, for example, when the notification channel comparison unit 176 determines that the notification channel detection value is equal to or less than the notification channel threshold, the notification channel determination unit 170 causes radio wave interference between the data reader 100 and the IC tag 200. Judge that it does not occur.

[0070] The determination unit 140 determines that the first comparison unit 126 determines that the first detection value is less than or equal to the first threshold value, and that the notification channel comparison unit 176 determines that the notification channel detection value is less than or equal to the notification channel threshold value. If it is determined, the processing device 980 determines that the radio wave does not interfere.

[0071] In addition to the function of the first embodiment, transmission unit 150 transmits a communication wave, which is a radio wave for communication such as a command, to IC tag 200. Thus, a notification wave, which is a radio wave for notifying other data readers 100, is transmitted to a notification channel assigned to a predetermined frequency. Here, the notification wave is an unmodulated wave or the like.

Next, the operation of the RFID system 300 including the data reading device 100 and the IC tag 200 according to the second embodiment will be described based on FIG. FIG. 7 is a flowchart illustrating an interference determination method that is an operation of the RFID system 300 including the data reading device 100 and the IC tag 200 according to the second embodiment. Here, only the operation different from that of the RFID system 300 according to the first embodiment will be described.

[0073] In the first interference level setting step and the notification channel interference level setting step (S201), the first interference level setting unit 122 is the threshold of the interference level of the specified frequency specified by the frequency specifying unit 110 as in (S101). A first threshold value is set and stored in the storage device 984. Also, the notification channel interference level setting unit 172 sets a notification channel threshold that is a threshold of the notification channel interference level, and stores the notification channel threshold in the storage device 984. For example, the first interference level setting step and the notification channel interference level setting step may be performed only when the data reader 100 is activated or may be performed after the frequency specifying step (S202).

(S202) The force and the like (S205) are the same as (S102) to (S105), respectively.

In the notification channel interference level detection step (S 206), notification channel interference level detection section 174 detects the notification channel detection value that is the interference level of the notification channel and stores it in storage device 984.

[0076] In the notification channel comparison step and determination step (S207), the notification channel comparison unit 176 detects the notification channel threshold set by the notification channel interference level setting unit 172 and the notification channel detection detected by the notification channel interference level detection unit 174. The processor 980 determines whether or not the notification channel detection value is equal to or less than the notification channel threshold. When the notification channel detection value is not more than the notification channel threshold value (YES in S207), the first interference level detection step (S208) is performed. On the other hand, the notification channel detection value is less than or equal to the notification channel threshold. If not (NO in S207), the process proceeds to the frequency changing step (S213). In other words, for example, when the notification channel comparison unit 176 determines that the notification channel detection value is equal to or less than the notification channel threshold value (YES in S207), the notification channel determination unit 170 determines whether the notification channel comparison unit 176 is between the data reader 100 and the IC tag 200. It is determined that no radio wave interference occurs. In this case, the determination unit 140 determines that the first comparison unit 126 determines that the first detection value is less than or equal to the first threshold, and the notification channel comparison unit 176 determines that the notification channel detection value is less than or equal to the notification channel threshold. Therefore, the processor 980 determines that the radio wave does not interfere. Then, the data reading apparatus 100 proceeds to the first interference level detection step (S208) which is the next process. On the other hand, the notification channel determination unit 170, for example, if the notification channel comparison unit 176 determines that the notification channel detection value is not less than or equal to the notification channel threshold value (NO in S207), the radio wave between the data reader 100 and the IC tag 200 It is determined that interference occurs. In this case, the determination unit 140 determines that the radio wave interferes with the processing device 980. Then, the data reading apparatus 100 proceeds to the frequency changing step (S213), changes the designated frequency, and again performs a processing power for determining whether or not the radio waves interfere with other data reading apparatuses 100. In other words, whether the radio wave interferes with the specified frequency until a frequency is found that does not cause radio wave interference with other data readers 100 and radio wave interference between data reader 100 and IC tag 200. Repeat the decision process. By this processing, radio wave interference between the other data reading apparatus 100 and radio wave interference between the data reading apparatus 100 and the IC tag 200 are avoided.

(S208) The force and the like (S209) are the same as (S108) to (S109), respectively.

[0078] In the command issuing step (S210), the transmitting unit 150 transmits a command to the IC tag 200 and notifies the other data reading device 100 that the radio wave is being transmitted to the IC tag 200. To the notification channel.

In the response receiving step (S211), receiving unit 160 receives a response to the command transmitted from transmitting unit 150 from the IC tag. Then, the transmission unit 150 stops the transmission of the notification wave

[0080] (S212) to (S213) are the same as (S112) to (S113), respectively.

[0081] According to the data reading device 100 and the RFID system 300 according to the second embodiment, the interference level of the notification channel is measured and assigned to the RFID system 300 including the specified frequency. This is equivalent to measuring the interference level of the selected frequency band. Therefore, according to the data reader 100 and RFID system 300 according to the embodiment 2, the interference level of only the notification channel is measured without measuring all the interference levels from the channel 1 to the channel 9. Thus, it is possible to determine whether or not radio waves between the data reading apparatus 100 and the IC tag 200 interfere. Therefore, according to the data reading device 100 and the RFID system 300 according to the second embodiment, it is possible to reduce the time required for carrier sense.

Here, the first interference level setting unit 122 sets the first threshold based on the magnitude of the output for transmitting the radio wave of the specified frequency, and the notification channel interference level setting unit 172 transmits the radio wave of the specified frequency. The notification channel threshold may be set based on the size of output to be output.

The first interference level setting unit 122 and the notification channel interference level setting unit 172 may change the first threshold value and the notification channel threshold value, respectively, when the magnitude of the output for transmitting the radio wave of the specified frequency is changed. That's okay.

When the output for transmitting radio waves at the specified frequency is low, compared to when the output for transmitting radio waves at the specified frequency is high, radio wave interference with other data readers 100 and IC tags 200 occurs. Become. Therefore, since the first interference level setting unit 122 and the notification channel interference level setting unit 172 set the first threshold and the notification channel threshold based on the magnitude of the output for transmitting the radio wave of the specified frequency, the data reader 100 radio waves can be efficiently emitted, and wireless communication between the data reader 100 and the IC tag 200 can be performed efficiently.

[0083] The RFID system according to the second embodiment can be summarized as follows: a memory that holds data, a command analysis unit that demodulates a command given from the outside and analyzes the command, and a memory control that reads or writes the memory An IC tag having a data read from the memory and a command execution unit that performs processing based on an analysis result in the command analysis unit, and a transmission unit that transmits the data read from the memory;

The data reader (a) transmits a command or an unmodulated wave to the IC tag. (1) Transmitter (b) A dedicated notification channel indicating that radio waves are being transmitted, and a second transmission unit that transmits unmodulated waves to the dedicated notification channel (c) A receiver that receives the response of the power of the IC tag (d) First interference level setting means for setting the interference level of the frequency to be used (e) Second interference level for setting the interference level of the dedicated notification channel larger than the interference level set by the first interference level setting means Setting means (f) First interference level detection means for detecting the interference level of the frequency to be used (g) Second interference level detection means for detecting the interference level of the dedicated notification channel (h) The first interference level detection means Is detected by the second interference level setting means, and the interference level detected by the second interference level detection means is set by the second interference level setting means. Below the interference level When the includes a control unit that performs the first transmission portion or the second transmission unit force also transmits control commands or unmodulated wave that.

[0084] Further, the data reading device includes: (a) a transmission output control unit that makes a transmission output variable (b) first interference level setting means that can change an interference level of a frequency to be used by a transmission output (c) Second interference level setting means is provided for setting the interference level of the frequency band or the notification dedicated channel according to the transmission output.

[0085] Embodiment 3.

Next, Embodiment 3 will be described. In Embodiment 3, radio waves are transmitted to IC tag 200 and IC tag 200 through a dedicated transmission channel having a predetermined frequency, and data is received from IC tag 200 through a dedicated reception channel having a frequency different from the dedicated transmission channel. An interference determination device that determines whether or not a radio wave used in an RFID system 300 including the reading device 100 interferes with a predetermined radio wave will be described.

First, the function of the RFID system 300 including the data reading device 100 and the IC tag 200 according to the third embodiment will be described with reference to FIG. FIG. 8 is a functional block diagram showing functions of the RFID system 300 including the data reader 100 and the IC tag 200 according to the third embodiment. Here, only functions different from those of the RFID system 300 according to the first embodiment will be described.

The data reading apparatus 100 according to the third embodiment does not include the first determination unit. Further, in the third embodiment, the transmission unit 150 transmits a dedicated transmission channel having a predetermined frequency to the IC tag 200. It is a transmission-dedicated channel use transmission unit that transmits radio waves on the channel. The reception unit 160 is a reception dedicated channel use reception unit that receives radio waves from the IC tag 200 through a reception dedicated channel having a frequency different from that of the transmission dedicated channel. That is, the frequency of the radio wave emitted from the data reader 100 and the frequency of the reflected wave emitted from the IC tag 200 are separated. Therefore, it is possible to prevent the occurrence of radio wave interference between the data reading device 100 and another data reading device 100.

Therefore, the data reading apparatus 100 according to the third embodiment does not need to include the first determination unit.

Next, the operation of the RFID system 300 including the data reading device 100 and the IC tag 200 according to the third embodiment will be described based on FIG. FIG. 9 is a flowchart illustrating an interference determination method that is an operation of the RFID system 300 including the data reader 100 and the IC tag 200 according to the third embodiment. Here, only the operation different from that of the RFID system 300 according to the first embodiment will be described.

In the second interference level setting step (S301), the second interference level setting unit 132 sets the interference level of the designated frequency band that is a frequency band including the designated frequencies of the plurality of frequency bands assigned to the RFID system 300. A second threshold value, which is a threshold value, is set and stored in the storage device 984. There is no need to set the first threshold. Others are the same as (S101).

[0090] (S302) is the same as (S102).

[0091] Further, (S303) and (S304) are the same as (S106) and (S107), respectively. That is, in the second interference level detection step (S303), the second interference level detection unit 134 detects the second detection value that is the interference level in the designated frequency band and stores it in the storage device 984. In the second comparison step and the determination step (S304), the second comparison unit 136 calculates the second threshold value set by the second interference level setting unit 132 and the second detection value detected by the second interference level detection unit 134. And the processor 980 determines whether the second detection value is less than or equal to the second threshold value. If the second detection value is equal to or smaller than the second threshold value (YES in S304), the data reading apparatus 100 performs a standby step (S305). On the other hand, when the second detection value is not equal to or smaller than the second threshold value (NO in S304), the data reading apparatus 100 proceeds to the frequency changing step (S311). That is, the second determination unit 130, for example, when the second comparison unit 136 determines that the second detection value is less than or equal to the second threshold (S3 04: YES), it is determined that there is no radio wave interference between the data reader 100 and the IC tag 200. In this case, the determination unit 140 determines that the radio wave does not interfere with the processing device 980 because the second comparison unit 136 determines that the second detection value is equal to or less than the second threshold value. Then, the data reading apparatus 100 proceeds to a standby step (S305) which is the next process. On the other hand, the second determination unit 130, for example, when the second comparison unit 136 determines that the second detection value is not less than or equal to the second threshold (NO in S304), the radio wave between the data reading device 100 and the IC tag 200 It is determined that interference occurs. In this case, the determination unit 140 determines that the radio wave interferes with the processing device 980 because the second comparison unit 136 determines that the second detection value is not less than or equal to the second threshold value. Then, the data reading device 100 proceeds to the frequency changing step (S311), changes the designated frequency, and again performs a determination processing power for determining whether or not the radio waves interfere with other data reading devices 100. In other words, the data reader 100 changes the specified frequency until a frequency at which no radio wave interference occurs between the data reader 100 and the IC tag 200 is found, and determines whether or not the radio wave interferes. repeat. With this process, the data reading apparatus 100 avoids radio wave interference between the data reading apparatus 100 and the IC tag 200. As described above, since no interference occurs between the data reading apparatus 100 and another data reading apparatus 100, verification using the first threshold value is not necessary.

[0092] (S305) is the same as (S105).

[0093] In the second interference level detection step (S306), as in the second interference level detection step (S303), the second interference level detection unit 134 detects the second detection value that is the interference level of the designated frequency band. Store in the storage device 984. In the second comparison step and determination step (S307), as in the second comparison step and determination step (S304), the second comparison unit 136 sets the second threshold value set by the second interference level setting unit 132. The second detection value detected by the second interference level detection unit 134 is compared, and the processor 980 determines whether the second detection value is less than or equal to the second threshold value. If the second detection value is less than or equal to the second threshold (YES in S307), the data reading apparatus 100 proceeds to the command issuing step (S308). On the other hand, when the second detection value is not less than or equal to the second threshold value (NO in S307), the data reading apparatus 100 proceeds to the frequency changing step (S311). That is, for example, when the second comparison unit 136 determines that the second detection value is equal to or smaller than the second threshold (YES in S307), the second determination unit 130 determines that the data reading device 100 is the same as the data reading device 100. IC It is determined that there is no radio wave interference with the group 200.

[0094] (S308) to (S311) are the same as (S110) to (S113), respectively.

In Embodiment 3, the data reader 100 transmits radio waves to the IC tag 200 using a transmission-dedicated channel having a predetermined frequency, and the IC tag 200 transmits radio waves using a reception-dedicated channel having a frequency different from that of the transmission-dedicated channel. Receive. That is, in the third embodiment, the frequency of the radio wave emitted from the data reading device 100 and the frequency of the reflected wave emitted from the IC tag 200 are separated. Therefore, it is possible to prevent radio wave interference between the data reader 100 and another data reader 100. Therefore, according to the data reading device 100 and the RFID system 300 according to the third embodiment, the second determination unit confirms that no interference occurs between the data reading device 100 and the IC tag 200. The reading device 100 can perform stable communication with the IC tag 200.

In the above, when the second comparison unit 136 determines in the second comparison step (S304, S307) that the second detection value is not less than or equal to the second threshold value (NO in S304, S307), the data reader 100 Advances to the frequency changing step (S311), and the frequency specifying unit 110 has changed the specified frequency. However, the data reader 100 is not limited to this, and may wait for a predetermined time before proceeding to the second interference level detecting step (S303)! /.

[0097] Also, the second interference level setting unit 132 may set the second threshold based on the magnitude of the output for transmitting the radio wave of the designated frequency. The second interference level setting unit 132 may change the second threshold when the magnitude of the output for transmitting the radio wave of the specified frequency is changed.

When the output for transmitting radio waves at the specified frequency is low, compared to when the output for transmitting radio waves at the specified frequency is high, radio wave interference with other data readers 100 and IC tags 200 occurs. Become. Therefore, since the second interference level setting unit 132 sets the second threshold based on the magnitude of the output for transmitting the radio wave of the specified frequency, the data reader 100 can efficiently emit the radio wave, and the data reader Wireless communication between 100 and the IC tag 200 can be performed efficiently.

Summarizing the RFID system according to the third embodiment, a memory for holding data, a command analysis unit for demodulating a command given from the outside and analyzing the command, and reading the memory A memory control unit that reads or writes data, a command execution unit that performs processing based on data read from the memory and an analysis result of the command analysis unit, and transmission means that transmits data read from the memory An RFID tag, and a data reader that performs non-contact data communication with the IC tag,

It is an RFID system comprising the following means for transmitting a command to the IC tag using a frequency dedicated for transmission and receiving a response having the power of the IC tag using a frequency dedicated for reception.

The data reader is (a) a transmitter that transmits a command or unmodulated wave to the IC tag, (b) a receiver that receives a response of the IC tag power, and (c) an RFID system that includes a frequency to be used. (D) Second interference level detection means for detecting the interference level of the frequency band assigned to the RFID system including the frequency to be used (e) ) When the interference level detected by the second interference level detection means is equal to or lower than the interference level set by the second interference level setting means, the transmission power is also a command, or control for performing transmission control of unmodulated waves A part.

[0099] Further, the data reading device includes: (a) a transmission output control unit that makes a transmission output variable; and (b) a second interference level setting unit that sets an interference level of a frequency band or a notification-dedicated channel according to the transmission output. Prepare.

[0100] Embodiment 4.

Next, Embodiment 4 will be described. In the fourth embodiment, unlike in the first embodiment, it is determined whether or not the radio wave having a predetermined frequency around the designated frequency interferes. Accordingly, the data reader 100 and the data reader 100 can prevent the interference of radio waves between the data reader 100 and another data reader 100 and the interference of radio waves between the data reader 100 and the IC tag 200. RFID system 300 equipped with

First, the function of the RFID system 300 including the data reading device 100 and the IC tag 200 according to the fourth embodiment will be described with reference to FIG. FIG. 10 is a functional block diagram showing functions of the RFID system 300 including the data reader 100 and the IC tag 200 according to the fourth embodiment. Here, functions different from those of the RFID system 300 according to the first embodiment are described. I will explain only.

The data reading apparatus 100 according to the fourth embodiment includes a peripheral frequency determination unit 180 instead of the second determination unit 130.

The peripheral frequency determination unit 180 performs coarse-accuracy carrier sensing on the peripheral frequency that is a predetermined frequency around (near) the frequency to be used. The reason why the coarse carrier sense is performed is, for example, to determine whether or not the data reader 100 and another data reader 100 are capable of causing radio wave interference between the IC tag 200 in communication. Here, the accuracy of carrier sense will be described later. The peripheral frequency determination unit 180 includes a peripheral frequency interference level setting unit 182, a peripheral frequency interference level detection unit 184, and a peripheral frequency comparison unit 186. The peripheral frequency interference level setting unit 182 sets a peripheral frequency threshold that is a threshold of the interference level of the peripheral frequency, and stores it in the storage device 984. The peripheral frequency interference level setting unit 18 2 sets each frequency of a plurality of predetermined frequencies within a predetermined frequency force within a predetermined range as a peripheral frequency, and the peripheral frequency threshold value increases as the peripheral frequency moves away from the specified frequency. You can set the value.

The peripheral frequency interference level detection unit 184 detects a peripheral frequency detection value that is an interference level of the peripheral frequency and stores it in the storage device 984. When there are a plurality of peripheral frequencies, the peripheral frequency interference level detection unit 184 detects the peripheral frequency detection value of each peripheral frequency. The peripheral frequency comparison unit 186 is a peripheral frequency threshold set by the peripheral frequency interference level setting unit 182. And the peripheral frequency detection value detected by the peripheral frequency interference level detection unit 184, and the processor 980 determines whether or not the peripheral frequency detection value is less than or equal to the peripheral frequency threshold. When there are a plurality of peripheral frequencies, the peripheral frequency comparison unit 186 compares the peripheral frequency threshold value with the peripheral frequency detection value for each peripheral frequency, and determines whether the peripheral frequency detection value is equal to or less than the peripheral frequency threshold value. judge.

In other words, for example, if the peripheral frequency comparison unit 186 determines that the peripheral frequency detection value is equal to or less than the peripheral frequency threshold value for all peripheral frequencies, the peripheral frequency determination unit 180 and the data reader 100 and other data It is determined that there is no radio wave interference with the IC tag 200 with which the reader 100 is communicating! [0103] The determination unit 140 determines that the first comparison unit 126 determines that the first detection value is less than or equal to the first threshold value, and the peripheral frequency comparison unit 186 determines that the peripheral frequency detection value is less than or equal to the peripheral frequency threshold value. In this case, the processor 980 determines that the radio wave does not interfere. When there are a plurality of peripheral frequencies, the determination unit 140 determines that the first comparison unit 126 determines that the first detection value is less than or equal to the first threshold value, and the peripheral frequency comparison unit 186 sets all the peripheral frequencies. On the other hand, if it is determined that the detected value of the peripheral frequency is below the peripheral frequency threshold, it is determined that the radio wave does not interfere.

Next, the interference level of the channel assigned to each frequency at a certain time will be described based on FIG. 11 and FIG. FIG. 11 is a diagram showing the interference level (c) 430 of the channel assigned to each frequency at a certain time. FIG. 12 is a diagram showing the interference level (d) 440 of the channel assigned to each frequency at a certain time. In FIG. 11 and FIG. 12, “CH-1” indicates channel 1, “CH-2” indicates channel 2, and “CH—” is read as a channel in the same manner. Here, it is assumed that each frequency in a certain frequency band assigned to the RFID system 300 is assigned to channel 1 to channel 9. For interference level (c) 430 and interference level (d) 440, the first interference level is the first threshold value, (N-1) is the interference level is (N-1) threshold, and (N-2) is the interference level. (N-2) Set as threshold. Here, the (N-1) threshold value and the (N-2) threshold value are examples of the peripheral frequency threshold value. Also, (N-1) interference level is the interference level of the specified frequency closest to the used frequency (adjacent channel), and (N-2) interference level is the second closest to the used frequency (next adjacent channel). This is the interference level at a given frequency.

[0105] At interference level (c) 430, channel 3, channel 6, and channel 8 are below the first threshold. Also, at interference level (c) 430, channel 7 is below the (N−1) threshold. At interference level (c) 430, channel 2 and channel 4 are below the (N−2) threshold. At interference level (c) 430, channel 1, channel 5, and channel 9 are larger than the (N−2) threshold.

[0106] At interference level (d) 440 mm, channel 3, channel 6, and channel 8 are below the first threshold. Also, at interference level (d) 440, channel 2, channel 4, and channel 7 are below the (N-1) threshold. Also, at interference level (d) 440, channel 1 and channel 5 are below the (N-2) threshold. Also, at interference level (d) 440, channel 9 is (N-2) Greater than threshold.

[0107] FIG. 13 shows how much noise is communicated as noise when another data reader 100 emits radio waves at different frequencies while the data reader 100 and the IC tag 200 are communicating at the frequency N. It shows how it affects. The vertical axis shows the strength against noise (CZD and the horizontal axis shows the frequency. Near the frequency used (N), the IC tag 200 is very vulnerable to noise. However, as the frequency force used increases, the noise Based on the characteristics of this IC tag 200, the interference level in the adjacent channel is (N-1) interference level, and the interference level in the next adjacent channel is (N-2) interference. The level is determined.

That is, the peripheral frequency interference level setting unit 182 sets the peripheral frequency threshold based on the characteristics of the IC tag 200 described above. Therefore, the peripheral frequency threshold is larger than the first threshold.

Next, the operation of the RFID system 300 including the data reading device 100 and the IC tag 200 according to the fourth embodiment will be described based on FIG. FIG. 14 is a flowchart illustrating an interference determination method that is an operation of the RFID system 300 including the data reading device 100 and the IC tag 200 according to the fourth embodiment. Here, only the operation different from that of the RFID system 300 according to the first embodiment will be described.

[0109] In the first interference level setting step and the peripheral frequency interference level setting step (S401), the first interference level setting unit 122, like (S101), sets the threshold of the interference level of the specified frequency specified by the frequency specifying unit 110. Is set and stored in the storage device 984. Also, the peripheral frequency interference level setting unit 182 sets a peripheral frequency threshold that is a threshold of the interference level of the peripheral frequency and stores it in the storage device 984. The peripheral frequency interference level setting unit 182 sets a peripheral frequency threshold value for each channel that is a predetermined frequency in the peripheral frequency range. The range of the peripheral frequency represents how many channels away from the specified channel power are subjected to carrier sense. For example, the first interference level setting step and the peripheral frequency interference level setting step may be performed only when the data reader 100 is activated, or may be performed after the frequency designation step (S402)! /, .

[0110] (S402) to (S405) are the same as (S102) to (S105), respectively.

[0111] In the level setting step (S406), the peripheral frequency determination unit 180 performs carrier sense. The peripheral frequency is set by the processor 980. Here, when the designated channel is N, the peripheral frequency range is J, and the variable is i, peripheral frequency determining section 180 sets the peripheral frequency channel for carrier sensing to the N−J + i channel. Variable i has an initial value of 0, for example, 0≤i≤2J. In other words, the carrier sense is performed up to the channel apart from the J channel with the designated channel N as the center.

[0112] In the peripheral frequency interference level detection step (S407), the peripheral frequency interference level detection unit 184 detects the peripheral frequency detection value that is the interference level of the peripheral frequency of the channel set in (S406), and stores it in the storage device 984. To remember.

[0113] In the peripheral frequency comparison step and determination step (S408), the peripheral frequency comparison unit 186

In the channel set in (S406), the peripheral frequency threshold set by the peripheral frequency interference level setting unit 182 is compared with the peripheral frequency detection value detected by the peripheral frequency interference level detection unit 184. The processor 980 determines whether or not the force is below the frequency threshold. If the detected peripheral frequency is equal to or lower than the peripheral frequency threshold (YES in S408), the level changing step (S409) is performed. On the other hand, if the detected peripheral frequency value is not less than or equal to the peripheral frequency threshold value (NO in S408), the process proceeds to the frequency changing step (S416). That is, for example, when the peripheral frequency comparison unit 186 determines that the peripheral frequency detection value is equal to or less than the peripheral frequency threshold (YES in S408), the peripheral frequency determination unit 180 performs data reading on the channel set in (S406). It is determined that radio wave interference between the device 100 and the IC tag 200 with which the other data reading device 100 is communicating does not occur. On the other hand, for example, when the peripheral frequency comparison unit 186 determines that the peripheral frequency detection value is not less than the peripheral frequency threshold (NO in S408), the peripheral frequency determination unit 186 sets the channel set in (S406). Then, it is determined that there is a radio interference between the data reading device 100 and the IC tag 200 with which the other data reading device 100 is communicating. In this case, the determination unit 140 determines that the radio wave interferes with the processing device 980. Then, the data reading apparatus 100 proceeds to the frequency changing step (S416), changes the designated frequency, and again performs a determination processing power for determining whether or not another data reading apparatus 100 interferes with radio waves. In other words, the determination unit 140 has at least one peripheral frequency threshold value set by the peripheral frequency interference level setting unit 182 detected by the peripheral frequency interference level detection unit 184 in all measured peripheral frequency channels. When it exceeds, it is determined that another data reader 100 in the vicinity gives interference to the communicating IC tag. Then, change the specified frequency until you find a frequency that does not cause radio wave interference with other data readers 100 or between the data reader 100 and the IC tag 200. Repeats the process of determining whether or not interference occurs.

[0114] In the level changing step (S409), the peripheral frequency determining unit 180 increases the variable i by 1.

(Increment).

[0115] In the level determination step and determination step (S410), the peripheral frequency determination unit 180 determines whether or not the variable i is larger than 2J by the processing device 980. That is, the peripheral frequency determination unit 180 determines whether the carrier sense up to all the channels separated from the J channel with the designated channel N as the center has been completed. If the surrounding frequency determination unit 180 determines that the variable i is greater than 2J (YES in S410), the determination unit 140 determines that the first comparison unit 126 determines that the first detection value is less than or equal to the first threshold value, and Since the peripheral frequency comparison unit 186 determines that the peripheral frequency detection value is equal to or lower than the peripheral frequency threshold value in all channels within the set range, the processing device 980 determines that radio waves do not interfere. Then, the data reading apparatus 100 proceeds to a first interference level detection step (S411) which is the next process. On the other hand, when the peripheral frequency determining unit 180 determines that the variable i is 2J or less (NO in S410), the peripheral frequency determining unit 180 returns to (S406) and performs carrier sense for the next channel.

That is, by the above processing, radio wave interference between the other data reading device 100 and radio wave interference between the data reading device 100 and the IC tag 200 are avoided.

[0117] (S411) to (S416) are the same as (S108) to (S113), respectively.

Next, an example of the operation of the RFID system 300 including the data reading device 100 according to the fourth embodiment and the IC tag 200 will be described based on FIGS. 11, 12, and 14. FIG.

First, the interference level of the channel assigned to each frequency is the interference level shown in FIG.

(c) Assume that the state is 430. First, in the first interference level setting step and the peripheral frequency interference level setting step (S401), it is assumed that the first interference level setting unit 122 sets the first threshold to the first interference level shown in FIG. Also, the peripheral frequency interference level setting unit 182 sets the (N-1) threshold of the peripheral frequency threshold to the (N-1) interference level shown in FIGS. 11 and 12, and sets the (N-2) of the peripheral frequency threshold. The threshold is set to (N-2) interference level shown in Fig. 11 and Fig. 12. Suppose that it is set. In other words, here J = 2.

Next, in the frequency designation step (S402), it is assumed that the frequency designation unit 110 designates channel 1. Next, in the first interference level detection step (S403), the first interference level detection unit 124 detects the interference level of channel 1. In the first comparison step (S404), the first comparison unit 126 determines that the first detection value is not less than or equal to the first threshold (NO in S104). That is, the first comparison unit 126 determines that the other data reading device 100 is using the channel 1. That is, when channel 1 is used, first comparison unit 126 determines that radio wave interference occurs with other nearby data reading devices 100.

Therefore, next, in the frequency changing step (S416), the frequency specifying unit 110 clears channel 1 which is the specified frequency. Next, in the frequency designation step (S402), the frequency designation unit 110 designates the designated frequency again. Here, it is assumed that frequency specifying section 110 has set channel 2. Then, the data reading apparatus 100 performs the first interference level detection step (S403) and the first comparison step (S404) again. In the first comparison step (S404), the first comparison unit 126 determines that another data reader 100 in the vicinity is using the channel 2.

Therefore, the data reading apparatus 100 performs a frequency changing step (S416) and a frequency specifying step (S402). In the frequency designation step (S402), it is assumed that the frequency designation unit 110 designates channel 3 as the designated frequency. Then, the data reading apparatus 100 performs the first interference level detection step (S403) and the first comparison step (S404) again. In the first comparison step (S404), the first comparison unit 126 determines that the first detection value is not more than the first threshold value (YES in S104). That is, the first comparison unit 126 determines that another data reading device 100 in the vicinity uses the channel 3.

Therefore, next, in a standby step (S405), the data reading apparatus 100 waits for execution of a predetermined time process. Next, in the level setting step (S406), the peripheral frequency determination unit 180 sets the channel of the peripheral frequency to channel 1, which is the (N-2) level channel. Because the specified channel is 3, the peripheral frequency range is J is 2, and i is the initial value 0, N− J + i is also a force of 1. Next, in the peripheral frequency interference level detection step (S407), the peripheral frequency interference level detection unit 184 determines the frequency of the channel set in (S406). The interference level of the side frequency is detected. In other words, here, peripheral frequency interference level detection section 184 detects the interference level of channel 1 set in (S406). Here, it is assumed that the interference levels from channel 1 to channel 9 are in the state of interference level (c) 430 shown in FIG. In the peripheral frequency comparison step and determination step (S408), the peripheral frequency comparison unit 186 determines that the peripheral frequency detection value is not less than the peripheral frequency threshold value (NO in S408) because channel 1 is larger than the (N-2) threshold value. judge. That is, the peripheral frequency comparison unit 186 determines that the use of the channel 1 affects the IC tag 200 in communication with the other data reader 100. That is, the peripheral frequency comparison unit 186 determines that interference between the IC tag 200 and the radio wave occurs.

[0121] Therefore, next, in the frequency changing step (S416), the frequency specifying unit 110 clears channel 3 which is the specified frequency. Next, in the frequency designation step (S402), the frequency designation unit 110 designates the designated frequency again. Then, the data reading apparatus 100 performs the first interference level detection step (S403) and the first comparison step (S404) again. As a result of repeating the above processing (S416 to S404), in the first comparison step (S404), the first comparison unit 126 determines that another data reader 100 in the vicinity uses the channel 6. The

Next, in a standby step (S405), the data reading apparatus 100 waits for execution of a predetermined time process. Next, in the level setting step (S406), the peripheral frequency determination unit 180 sets the channel of the peripheral frequency to channel 4 which is the (N-2) level channel. Next, in the peripheral frequency interference level detection step (S407), the peripheral frequency interference level detection unit 184 detects the interference level of the peripheral frequency of the channel set in (S406). That is, here, peripheral frequency interference level detection section 184 detects the interference level of channel 4 set in (S406). Here, it is assumed that the interference levels from channel 1 to channel 9 are in the state of interference level (c) 430 shown in FIG. In the peripheral frequency comparison step and determination step (S408), the peripheral frequency comparison unit 186 determines that the peripheral frequency detection value is the peripheral frequency threshold value because channel 4 is smaller than the peripheral frequency threshold value of the (N-2) level setting value. It is determined as follows (YES in S408). Therefore, in the level changing step (S409), the peripheral frequency determining unit 180 increases the variable i by 1 and the level determining step. In the step, determination step (S410), the peripheral frequency determination unit 180 determines whether or not the variable i is greater than 2J. Here, since i is 0 and J is 2, i is determined to be 2J or less, and the process returns to (S406) to perform carrier sense for the next channel. Therefore, in (S406), the peripheral frequency channel is set to channel 4, which is the (N-1) level channel. (S4 07) is executed, and in (S408), the peripheral frequency comparison unit 186 determines that the peripheral frequency detection value is the peripheral frequency threshold because channel 5 is larger than the peripheral frequency threshold of the (N-1) level setting value. Judged as 以下 (NO in S408).

[0123] Therefore, the process proceeds again to (S416), and the designated frequency is designated in (S402). Then, the data reading apparatus 100 performs a first interference level detection step (S403) and a first comparison step (S404). Here, it is assumed that the interference level force of the channel assigned to each frequency is in the state of interference level (d) 440 shown in FIG.

As a result of repeating the above processing (S416 to S404), in the first comparison step (S404), the first comparison unit 126 determines that another data reader 100 in the vicinity does not use the channel 3.

[0124] A standby step (S405) and a level setting step (S406) are performed. Here, carrier sense is performed for channel 1 to channel 5. (N-2) Level setting value channel 1 and channel 5 are (N-2) smaller than interference level (N-1) Level setting value channel 2 and channel 4 are (N-1) ) Less than interference level. Therefore, as a result of repeating the peripheral frequency determination processing (S406 force et al. S410), in the peripheral frequency interference level detection step (S408), the peripheral frequency comparison unit 186 detects the peripheral frequency in all measured peripheral frequency channels. It is determined that the value is equal to or lower than the peripheral frequency threshold (YES in S408). In the level determination step and determination step (S410), when the carrier sense up to channel 5 is completed, the peripheral frequency determination unit 180 determines that i is greater than 2J (YES in S410), and the determination unit 140 The first comparison unit 126 determines that the first detection value is equal to or less than the first threshold value, and the peripheral frequency comparison unit 186 determines that the peripheral frequency detection value is equal to or less than the peripheral frequency threshold value for all channels in the set range. judge.

[0125] Therefore, next, the data reader 100 performs the first interference level detection step (S411) and the first comparison step (S412), and the channel 3 is in the vicinity even after a predetermined time has elapsed. Make sure that the other data reader 100 is using channel 3. That is, the data reading apparatus 100 confirms that no radio wave interference occurs with other data reading apparatuses 100 in the vicinity even if the channel 3 is used after a predetermined time has elapsed.

[0126] If the confirmation is obtained (YES in S412), the data reading apparatus 100 performs the command issuing step.

(S413), a response reception step (S414), and an end determination step (S415) are performed.

[0127] According to the data reader 100 and the RFID system 300 according to the fourth embodiment, the data reader 100 can be arranged even when a plurality of data readers are arranged in the vicinity by measuring the interference level of the peripheral frequency. By preventing interference between the data reader 100 and the IC tag 200, the data reader 100 can perform stable communication with the IC tag 200.

[0128] Here, in the above, the interference level of a plurality of surrounding frequencies is sequentially measured and compared, the force Fourier transform is performed, the interference level for each frequency is detected at once, and the interference level of each frequency is compared. Anyway.

[0129] The RFID system according to the fourth embodiment is summarized as follows: a memory that holds data, a command analysis unit that demodulates a command given from the outside and analyzes the command, and a memory control that reads or writes the memory An IC tag having a data read from the memory and a command execution unit that performs processing based on an analysis result in the command analysis unit, and a transmission unit that transmits the data read from the memory;

The data reader (a) transmits a command or unmodulated wave to the IC tag (b) receives a response from the IC tag (c) sets the interference level of the frequency to be used (D) Peripheral frequency interference level setting means for setting interference levels of a plurality of adjacent frequencies larger than the interference level set by the first interference level setting means (e) First interference level detection means for detecting the interference level (f) Peripheral frequency interference level detection means for detecting the interference level at a plurality of frequencies adjacent to the frequency to be used (g) The first interference level detection means The detected interference level is less than or equal to the interference level set by the first interference level setting means, and A control unit that performs transmission control of a command or an unmodulated wave from the transmission unit when the interference level detected by the peripheral frequency interference level detection unit is equal to or less than the interference level set by the peripheral frequency interference level setting unit .

Brief Description of Drawings

FIG. 1 is a diagram showing an example of a hardware configuration of a data reading device 100 in an embodiment.

FIG. 2 is a functional block diagram showing functions of an RFID system 300 including the data reading device 100 and the IC tag 200 according to the first embodiment.

FIG. 3 is a diagram showing an interference level (a) 410 of a channel assigned to each frequency at a certain time.

FIG. 4 is a diagram showing an interference level (b) 420 of a channel assigned to each frequency at a certain time.

FIG. 5 is a flowchart showing an interference determination method that is an operation of the RFID system 300 including the data reading device 100 and the IC tag 200 according to the first embodiment.

FIG. 6 is a functional block diagram showing functions of an RFID system 300 including the data reading device 100 and the IC tag 200 according to the second embodiment.

FIG. 7 is a flowchart showing an interference determination method that is an operation of the RFID system 300 including the data reading device 100 and the IC tag 200 according to the second embodiment.

FIG. 8 is a functional block diagram showing functions of an RFID system 300 including a data reading device 100 and an IC tag 200 according to a third embodiment.

FIG. 9 is a flowchart showing an interference determination method that is an operation of the RFID system 300 including the data reading device 100 and the IC tag 200 according to the third embodiment.

FIG. 10 is a functional block diagram showing functions of an RFID system 300 including a data reading device 100 and an IC tag 200 according to a fourth embodiment.

FIG. 11 is a diagram showing an interference level (c) 430 of a channel assigned to each frequency at a certain time.

FIG. 12 is a diagram showing an interference level (d) 440 of a channel assigned to each frequency at a certain time. FIG. 13 is a diagram showing frequency vs. noise characteristics of an IC tag.

FIG. 14 is a flowchart showing an interference determination method that is an operation of the RFID system 300 including the data reading device 100 and the IC tag 200 according to the fourth embodiment.

Explanation of symbols

100 Data reader, 110 Frequency specification unit, 120 First determination unit, 122 First interference level setting unit, 124 First interference level detection unit, 126 First comparison unit, 130 Second determination unit, 1 32 Second interference Level setting section, 134 Second interference level detection section, 136 Second comparison section, 140 Judgment section, 150 Transmission section, 160 Reception section, 170 Notification channel determination section, 172 Notification channel interference level setting section, 174 Notification channel interference level Detection unit, 176 notification channel comparison unit, 180 ambient frequency determination unit, 182 ambient frequency interference level setting unit, 184 ambient frequency interference level detection unit, 186 ambient frequency comparison unit, 410 interference level (a), 4 20 interference level ( b), 430 interference level (c), 440 interference level (d), 901 LCD, 90 2 touch panel, 904 FDD, 905 CDD, 908 database, 909 system unit, 910 Sano, 911 CPU, 912 NOS, 913 ROM, 914 RAM, 915 communication board, 920 magnetic Disk device, 921 OS, 922 window system, 923 program group, 924 file group, 940 Internet, 941 gateway, 942 LAN, 980 processing device, 982 input device, 984 storage device, 986 communication device.

Claims

The scope of the claims

[1] In an interference judgment device for judging whether or not a radio wave used in an RFID (Radio Frequency IDentification) system including an IC (Integrated Circuit) tag and a data reader interferes with a predetermined radio wave,

A frequency designating unit for designating a designated frequency, which is a frequency of the predetermined radio wave, by an input device;

A first interference level setting unit that sets a first threshold value that is a threshold value of an interference level of a specified frequency specified by the frequency specifying unit, and stores the first threshold value in a storage device;

A first interference level detector that detects a first detection value that is an interference level of the specified frequency and stores the first detection value in a storage device;

The first threshold value set by the first interference level setting unit and the first detection value detected by the first interference level detection unit are compared, and whether or not the first detection value is less than or equal to the first threshold is processed. A first comparison unit determined by

A second interference level setting unit that sets a second threshold value that is a threshold value of an interference level of a specified frequency band that is a frequency band including the specified frequency of a plurality of frequency bands assigned to the RFID system, and stores the second threshold value in a storage device;

A second interference level detection unit that detects a second detection value that is an interference level of the designated frequency band and stores the second detection value in a storage device;

The second threshold value set by the second interference level setting unit and the second detection value detected by the second interference level detection unit are compared, and whether or not the second detection value is less than or equal to the second threshold value is processed. A second comparison unit determined by

If the first comparison unit determines that the first detection value is less than or equal to the first threshold value, and the second comparison unit determines that the second detection value is less than or equal to the second threshold value, radio waves do not interfere. Judgment unit to judge by the processing equipment

An interference determination device comprising:

[2] The second interference level detection unit detects the interference level of each channel of the plurality of channels assigned to the designated frequency band as a second detection value and stores it in a storage device, and the second comparison unit The second threshold and each channel detected by the second interference level detector Each of the second detection values for each channel, determine whether each second detection value for each channel is less than or equal to the second threshold,

The determination unit determines that the first comparison unit determines that the first detection value is equal to or less than a first threshold value, and

If the second comparison unit determines that all the second detection values for each channel are less than or equal to the second threshold, the radio wave is determined not to interfere.

The interference judgment device according to claim 1, wherein:

[3] The interference judgment device according to claim 1, wherein the second threshold set by the second interference level setting unit is larger than the first threshold set by the first interference level setting unit.

[4] The first interference level setting unit sets the first threshold based on the output level for transmitting the radio wave of the specified frequency,

The second interference level setting unit sets the second threshold based on the magnitude of the output for transmitting the radio wave of the specified frequency.

The interference judgment device according to claim 1, wherein:

[5] When an IC (Integrated Circuit) tag and a communication wave, which is a communication radio wave, are transmitted to the IC tag, the notification wave, which is a radio wave for communication, is sent to a notification channel assigned to a predetermined frequency. In an interference judgment device for judging whether or not a radio wave used in an RFID (Radio Frequency IDentification) system provided with a data reader for transmission interferes with a predetermined radio wave,

Set the notification channel threshold, which is the threshold for the interference level of the notification channel, and store it in the storage device. A notification channel interference level setting unit,

A notification channel interference level detection unit that detects a notification channel detection value that is an interference level of the notification channel and stores it in a storage device;

The notification channel threshold set by the notification channel interference level setting unit is compared with the notification channel detection value detected by the notification channel interference level detection unit, and whether or not the notification channel detection value is equal to or less than the notification channel threshold is processed. A notification channel comparison unit determined by the device;

When the first comparison unit determines that the first detection value is less than or equal to the first threshold, and the notification channel comparison unit determines that the notification channel detection value is less than or equal to the notification channel threshold, radio waves do not interfere. And a judging unit for judging by the processing device

An interference determination device comprising:

6. The interference determination device according to claim 5, wherein the notification channel threshold set by the notification channel interference level setting unit is larger than the first threshold set by the first interference level setting unit.

[7] The first interference level setting unit sets the first threshold based on the magnitude of the output for transmitting the radio wave of the specified frequency,

The notification channel interference level setting unit sets a notification channel threshold based on the magnitude of the output for transmitting the radio wave of the specified frequency.

The interference judgment device according to claim 5, wherein:

[8] Provided with an IC (Integrated Circuit) tag and a data reader that transmits radio waves of a predetermined frequency to the IC tag and receives radio waves of a frequency different from the predetermined frequency from the IC tag

In an interference judgment device that judges whether radio waves used in RFID (Radio Frequency IDentification) systems interfere with predetermined radio waves,

A second interference level setting unit that sets a second threshold value that is a threshold value of an interference level of a specified frequency band that is a frequency band including the specified frequency of a plurality of frequency bands assigned to the RFID system, and stores the second threshold value in a storage device; A second interference level detection unit that detects a second detection value that is an interference level of the designated frequency band and stores the second detection value in a storage device;

When the second comparison unit determines that the second detection value is equal to or smaller than the second threshold value, the determination unit determines that the radio wave does not interfere with the processing device.

An interference determination device comprising:

[9] The second interference level setting unit sets the second threshold based on the magnitude of the output for transmitting the radio wave of the specified frequency.

9. The interference judgment device according to claim 8.

[10] An interference determination device that determines whether or not a radio wave used in an RFID (Radio Frequency IDentification) system including an IC (Integrated Circuit) tag and a data reader interferes with a predetermined radio wave,

A peripheral frequency interference level setting unit that sets a peripheral frequency threshold that is a threshold of an interference level of the peripheral frequency and stores it in a storage device with a predetermined frequency within a predetermined range from the specified frequency as a peripheral frequency;

A peripheral frequency interference level detection unit that detects a peripheral frequency detection value that is an interference level of the peripheral frequency and stores it in a storage device; The peripheral frequency threshold set by the peripheral frequency interference level setting unit is compared with the peripheral frequency detection value detected by the peripheral frequency interference level detection unit, and whether or not the peripheral frequency detection value is equal to or less than the peripheral frequency threshold is determined by the processing device. The peripheral frequency comparison unit for determining, the first comparison unit determines that the first detection value is equal to or less than the first threshold value, and the peripheral frequency comparison unit determines that the peripheral frequency detection value is equal to or less than the peripheral frequency threshold value. If it is determined, the processing unit determines that the radio wave does not interfere with

An interference determination device comprising:

11. The interference determination device according to claim 10, wherein the peripheral frequency threshold set by the peripheral frequency interference level setting unit is larger than the first threshold set by the first interference level setting unit.

[12] The peripheral frequency interference level setting unit sets each frequency of a plurality of predetermined frequencies within a predetermined range from the specified frequency as a peripheral frequency, and the peripheral frequency threshold increases as the peripheral frequency is separated from the specified frequency force. Set a large value to

The peripheral frequency interference level detection unit detects a peripheral frequency detection value of each of the plurality of predetermined frequencies,

The peripheral frequency comparison unit compares the peripheral frequency threshold value with the peripheral frequency detection value for each of the plurality of predetermined frequencies, and determines whether the peripheral frequency detection value is equal to or less than the peripheral frequency threshold value. And

If the peripheral frequency comparison unit determines that the peripheral frequency detection value is equal to or less than the peripheral frequency threshold for all of the plurality of predetermined frequencies, it determines that the radio wave does not interfere.

The interference judgment device according to claim 10.

[13] The interference judgment device according to claim 1,

When the determination unit of the interference determination device determines that the radio wave does not interfere! 送信, a transmission unit that transmits a command to the IC tag by the communication device;

A data reading apparatus comprising: a receiving unit that receives a response to a command transmitted by the transmitting unit as well as an IC tag power.

[14] The interference judgment device according to claim 5,

When the determination unit of the interference determination device determines that the radio wave does not interfere! ヽ, the transmission unit transmits a command to the IC tag by the communication device.

[15] The interference judgment device according to claim 8,

[16] The interference judgment device according to claim 10,

[17] An RFID system comprising the data reader according to claim 13 and an IC tag,

IC tag

An IC tag receiving unit that receives a command transmitted by the transmitting unit of the data reader by the communication device;

An IC tag transmitter that performs processing based on the command received by the IC tag receiver and transmits the processing result by the communication device.

An RFID system comprising:

[18] An RFID system comprising the data reader according to claim 14 and an IC tag,

IC tag

An IC tag transmitter that performs processing based on the command received by the IC tag receiver and transmits the processing result by the communication device. An RFID system comprising:

[19] An RFID system comprising the data reader according to claim 15 and an IC tag,

IC tag

An RFID system comprising:

[20] An RFID system comprising the data reader according to claim 16 and an IC tag,

IC tag

An RFID system comprising:

[21] Interference judgment by an interference judgment device that judges whether radio waves used in RFID (Radio Frequency IDentification) systems equipped with IC (Integrated Circuit) tags and data readers interfere with predetermined radio waves In the method

A frequency designating step in which a frequency designating unit designates a designated frequency, which is a frequency of the predetermined radio wave, by an input device;

A first interference level setting step in which the first interference level setting unit sets and stores the first threshold value, which is the threshold value of the interference level of the specified frequency specified in the frequency specifying step, in the storage device;

A first interference level detection step in which the first interference level detection unit detects the first detection value that is the interference level of the designated frequency and stores it in the storage device;

The first comparison unit compares the first threshold value set in the first interference level setting step and the first detection value detected in the first interference level detection step, and the first detection value is not more than the first threshold value. A first comparison step in which the first comparison unit determines whether or not the force is detected by the processing device; The second interference level setting unit sets a second threshold value that is a threshold value of an interference level of a specified frequency band that is a frequency band including the specified frequency of a plurality of frequency bands assigned to the RFID system, and stores the second threshold value in a storage device. An interference level setting step;

A second interference level detection step in which the second interference level detection unit detects the second detection value, which is the interference level of the specified frequency band, and stores it in the storage device;

The second comparison unit compares the second threshold value set in the second interference level setting step and the second detection value detected in the second interference level detection step, and the second detection value is equal to or less than the second threshold value. A second comparison step in which the second comparison unit determines whether or not the force is detected by the processing device;

If it is determined in the first comparison step that the first detection value is less than or equal to the first threshold value and the second comparison step is determined to be less than or equal to the second threshold value, the radio wave does not interfere. ! ヽ

An interference determination method comprising:

In the interference judgment program of the interference judgment device that judges whether radio waves used in RFID (Radio Frequency IDentification) systems equipped with IC (Integrated Circuit) tags and data readers interfere with predetermined radio waves,

The first comparison unit compares the first threshold value set in the first interference level setting step and the first detection value detected in the first interference level detection step, and the first detection value is not more than the first threshold value. A first comparison step in which the first comparison unit determines whether or not the force is detected by the processing device;

The second interference level setting unit sets a second threshold value that is a threshold value of an interference level of a specified frequency band that is a frequency band including the specified frequency of a plurality of frequency bands assigned to the RFID system, and stores the second threshold value in a storage device. An interference level setting step; A second interference level detection step in which the second interference level detection unit detects the second detection value, which is the interference level of the specified frequency band, and stores it in the storage device;

An interference determination program that causes a computer to execute.