JP2002271229A - Rfid-retrieving device and article retrieving method using rfid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To retrieve an RFID or an article attached with an RFID. SOLUTION: An RFID-retrieving device 1 retrieves a specific RFID tag 12 from RFID tags 12, 13, 14, and so on attached to articles 2, 3, 4, and so on by a radio wave 10 transmitted from an antenna 11. An existence determining means 21 determines that the RFID tag 12 to be retrieved exists when receiving data matched with preliminarily inputted data. A range narrowing means 22 changes the transmitting direction of the radio wave 10 to the right and left by using the directivity of the antenna 11. A direction-instructing means 23 instructs the center of right and left critical angles, where it is determined that the RFID tag 12 exists as the directions where it is determined that the RFID tag 12 exists with light.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises an antenna and a semiconductor integrated circuit chip, receives a radio wave from the antenna, generates operating power from the received radio wave, and stores the power in the semiconductor integrated circuit chip. An RFID (Radiator) that generates a reflected wave changed according to the stored data and reads the stored data from a transmission source of a radio wave.
The present invention relates to an RFID search device that searches for the location of dio frequency IDentification) and an article search method that uses RFID.

[0002]

2. Description of the Related Art Conventionally, RFID is attached to an article placed in a distribution process or the like as an article identification technique instead of a barcode, and is used to identify the article. RF
The ID stores identification information in the semiconductor integrated circuit chip, and the stored identification information can be read in a non-contact manner via a radio wave. An RFID holds information as data in a semiconductor integrated circuit chip, and thus is also called a data carrier. In addition, since data is read so as to respond to a question by a radio wave, it is also called a transponder. In this case, R which transmits a radio wave and reads data
The FID reader is also called an interrogator. An RFID semiconductor integrated circuit chip extracts operation power from radio waves and can operate without a power source such as a battery. In a semiconductor integrated circuit chip, a non-volatile memory to which data can be written, such as a flash memory, is used to store data. A device that writes data to an RFID is called an RFID writer.

[0003] The RFID is small and can be easily attached to an article like a tag. Therefore, RF
The ID is also called a wireless tag capable of reading identification information without contact. A plurality of articles with RFID attached as tags may be present in the data reading range.
In such a case, even if the identification information is read from the RFID,
It becomes impossible to know which article is identified by the identification information. In order to detect a target article from a plurality of RFID tag-attached articles, a light emitting diode (LED) is added to the RFID tag, and the light emitting diode of the target RFID tag emits light. There has been proposed a method of indicating which article is.

Japanese Patent Laid-Open Publication No. Hei 10-224144 discloses a technique in which a plurality of multi-element planar antennas are switched to change the receiving angle over a wide range in order to read data from a container or the like on which an RFID tag is mounted. ing. This is because when the RFID tag moves in a short distance at a high speed, it is necessary to perform wireless communication in a wide angle range.

[0005]

Since an RFID tag can communicate with a reader or the like by non-contact wireless communication, it is often used by attaching it to an article or storing it in a packing box. For this reason, RFID tags
It is rare that the user is in a position or state that is always visible to the user.
When there is a possibility that an RFID tag may be attached to a plurality of articles, as conventionally proposed, an RF tag is used.
Even if a light emitting diode is attached to the ID tag and the light emitting diode emits light, a target RFID tag or article cannot be searched for unless the user can see it. When the receiving angle is widened by utilizing the characteristics of the antenna as in Japanese Patent Application Laid-Open No. H10-224144, the number of articles to be searched increases, and it becomes more difficult to identify the target RFID tag or article. turn into.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an RFID search apparatus and an article search method using an RFID, which enable search for an RFID or an article attached with the RFID.

[0007]

SUMMARY OF THE INVENTION According to the present invention, a radio wave is received, operating power is generated from the received radio wave, and a reflected wave changed according to data stored in the radio wave is generated. An RFID search apparatus for searching for an existence position of an RFID for reading data stored in a transmission source of a radio wave, wherein the radio wave for reading data is located in a range of a space in which the RFID is presumed to be present. Receiving a reflected wave from the RFID,
Presence determining means for determining whether an RFID is present;
When the presence determining unit determines that the RFID is present, the range determining unit changes the transmission range of the radio wave by the radio wave transmitting unit, and narrows the range of the space in which the presence determining unit determines that the RFID is present; The range of the space narrowed down by RFI
And a direction designating means for designating a search direction of D.

According to the present invention, the RFID search device receives a radio wave, generates operating power from the received radio wave, and generates a reflected wave changed according to data stored therein. A radio wave transmitting means, an existence determining means, and an RFID for reading data stored in a transmission source of a radio wave, in order to search for an existing position;
It includes a range narrowing unit and a direction instruction unit. The presence judging means receives a reflected wave from the RFID with respect to the data-reading radio wave transmitted by the radio wave transmitting means, and
It is determined whether D exists. Range narrowing means,
The range of the space in which the presence determination unit determines that the RFID is present is narrowed down by changing the transmission range of the radio wave by the radio wave transmission unit. RF in the narrowed space
Since the ID exists, the direction in which the RFID exists can be known by giving an instruction as the search direction of the RFID by the direction indicating means.

Further, in the present invention, the direction instructing means instructs a search direction of the RFID by a light emission direction.

According to the present invention, since the direction indicating means indicates the search direction of the RFID by the light emission direction, it is possible to easily indicate the search direction with a simple and small configuration.

Further, in the present invention, the RFID determination means includes:
Only when the data read from the RFID matches the data set in advance, it is determined that the RFID exists.

According to the present invention, even if a plurality of RFIDs are present, it is possible to search for only those RFIDs whose stored data matches the preset data, and indicate the direction in which the RFIDs exist.

Further, in the present invention, the radio wave transmitting means can change the transmitting direction of the radio wave, and the range narrowing means changes the transmitting direction of the radio wave from the radio wave transmitting means to change the direction of the space. When the direction indicating means narrows the range, the one-side limit angle at which the RFID is determined to be present when the transmission direction of the radio wave is changed to one side and the transmission angle of the radio wave is changed to the other side. RFID
The search direction of the RFID is designated as the center with the other limit angle determined to be present.

According to the present invention, the radio wave transmitting means can transmit a radio wave to a certain range in the surrounding space by the directivity of the antenna or the like, and can change the transmitting direction. The range narrowing unit changes the transmitting direction of the radio wave from the radio wave transmitting unit between one side and the other side, and obtains a limit angle at which it is determined that the RFID is present. When the transmission direction is at the limit angle, the RFID is located near the boundary that is the limit of the transmission direction.
Exists, the central direction between the one-side limit angle and the other-side limit angle can be set as the search direction in which the RFID exists.

Further, according to the present invention, a radio wave is received, operating power is generated from the received radio wave, and a reflected wave changed according to data stored therein is generated.
An article search method using an RFID for searching for an existence position of an article to which an RFID for reading data stored in a transmission source of a radio wave is attached.
Transmits a radio wave for data reading in a range of a space where it is presumed that an article with an ID is present, receives a reflected wave from the RFID, and determines whether or not the RFID is present,
When it is determined that the RFID is present, the transmission range of the radio wave is changed, the range of the space where the RFID is determined to be present is narrowed, and the range of the narrowed space is defined as RFI.
This is a method for searching for an article using RFID, wherein D is designated as a search direction of the article to which the attached article is attached.

According to the present invention, a radio wave is received, operating power is generated from the received radio wave, and a reflected wave changed according to data stored in the radio wave is generated.
An RFID for reading the stored data from the transmission source of the radio wave is attached to the article, the RFID is searched, and the location of the article to which the RFID is attached is searched. The first to search for articles with RFID attached
As a step, the presence of the RFID is determined. In the second step, the range of the space where the RFID exists is narrowed down, and the narrowed down range of the space is designated as the search direction. Even in a state where a plurality of articles exist and the RFID cannot be directly viewed, the direction in which the RFID exists can be specified, so that the target article can be easily found. RF
When there are a plurality of IDs, the ID can be identified by the data to be read, and the target article can be easily found.

Further, in the present invention, the narrowing of the space is performed by angularly displacing the transmitting direction of the radio wave to the left and right in a horizontal plane, and detecting a left limit angle which can be detected by the RFID when angularly displacing to the left; When the angular displacement is made in the direction, the right limit angle which can be detected by the RFID is obtained, and the center of the left limit angle and the right limit angle is designated as the search direction.

According to the present invention, the transmission direction of the radio wave is angularly displaced left and right in the horizontal plane, and the search direction is designated as the center of the left and right limit angles at which RFID can be detected. It can be carried out.

Further, in the present invention, the narrowing of the space is performed by angularly displacing the transmission direction of the radio wave vertically in a vertical plane, and detecting an upper limit angle that can be detected by RFID when angularly displacing upward. When the angular displacement is made, a lower limit angle detectable by the RFID is obtained, and the center of the upper limit angle and the lower limit angle is designated as the search direction.

According to the present invention, the transmission direction of the radio wave is angularly displaced up and down in the vertical plane, and the search direction is designated as the center of the upper and lower limit angles at which RFID can be detected. It can be performed.

[0021]

FIG. 1 is a plan view showing an outline of an article search method using an RFID search apparatus 1 according to an embodiment of the present invention. The RFID search device 1 emits a radio wave including an antenna 11 for transmitting a radio wave 10 in a space where a search target article 2, 3, 4,... Having means. Articles 2, 3, 4, ... have an RFID tag 1
Are attached respectively. Each R
Each of the FID tags 12, 13, 14,.
Data for identifying 4,... Is previously written and stored. The radio wave transmitting unit 11 transmits a radio wave 10 in a range of a left limit 10L and a right limit 10R. The transmitted radio wave 10 is transmitted to the RFID tags 12, 13, 1
, And received by each of the RFID tags 12, 13, 14,
... generate a reflected wave changed according to the stored data.

The RFID search device 1 includes a receiving circuit 20 for receiving reflected waves from the RFIDs 12, 13, 14,... Received by the antenna 11, an existence determining unit 21, a range narrowing unit 22, a direction indicating unit. 23 are included.
The presence determining means 21 is provided for the RFID tags 12, 1 with respect to the data reading radio wave 10 transmitted from the antenna 11.
The at least one RFID tag 12, 13, 1 is determined by whether or not the receiving circuit 20 receives the reflected wave from 3, 14,.
It is determined whether 4,... Exist. If no reflected wave is received by the receiving circuit 20, the RFID tag 12, 1
.. Can be determined to not exist at all.

As shown in FIG. 1, a plurality of articles 2,
RFID tags 12, 13, 1 attached to 3, 4, ...
In order to search for an arbitrary RFID tag from among 4,.
The data written in the ID tag is input. Only when the data represented by the reflected wave received by the receiving circuit 20 matches the input data, the presence determination unit 21
It is determined that the ID exists.

Even if it is determined that the target article exists among the plurality of articles 2, 3, 4,..., The article cannot be specified. The direction in which the target article is present is narrowed down by the range narrowing means 22 and is instructed by the direction instructing means 23. Thereby, the plurality of RFID tags 12, 1
Even if 3, 14,... Exist, only the RFID tag whose stored data matches the preset data can be searched to indicate the direction in which the tag exists.

The range narrowing means 22 includes the existence determining means 2
The range of the space where it is determined that the RFID to be searched for exists according to 1 is narrowed down by changing the transmission range of the radio wave 10 from the antenna 11. Since the search target RFID exists in the narrowed space, the direction instructing unit 23
Indicates the search direction of the RFID. The direction instructing means 23 detects the direction of light emission of the RFID tags 12, 13,.
.. Can be indicated. Since the direction instructing means 23 instructs the search direction of the RFID by the light emitting direction, the RFID tag 12,
13, 14, ... The search direction can be easily specified.

FIG. 2 shows the RFID tags 12, 13, and
Regarding 14,..., A schematic configuration is shown in plan view. R
In the FID tags 12, 13, 14,..., A semiconductor integrated circuit chip 31 and an antenna 32 are mounted on a substrate 30 made of an electrically insulating synthetic resin or ceramic. On the semiconductor integrated circuit chip 31, a microcomputer, a memory, a transmission / reception circuit, a power supply circuit, and the like are formed. The power supply circuit extracts power necessary for operating the semiconductor integrated circuit chip 31 from the radio wave received by the antenna 32. The memory includes a flash memory which is non-volatile and to which data can be written. When a radio wave is received by the antenna 32, the microcomputer controls the transmission / reception circuit to transmit a reflected wave from the antenna 32 according to the data written in the memory.

The antenna 32 is formed on the substrate 30 with a conductor pattern or the like so as to be of a dipole type capable of receiving the radio wave 10 in a frequency band of several GHz, for example.
The substrate 30 has, for example, a rectangular shape, and can be formed such that the length L of the long side is about several tens mm and the width W of the short side is about 10 mm.

FIG. 3 shows a concept of narrowing down, for example, the existence range of the RFID tag 12 among the plurality of RFID tags 12, 13, 14,... By the range narrowing means 22 of FIG. First, as shown in FIG.
The direction of transmission / reception of the radio wave 10 based on the directivity of 1 is shifted to the leftward limit at which the RFID tag 12 to be searched can return a response. On the left side of the right limit 10R,
In addition, it is estimated that the RFID tag 12 to be searched exists at a position near the right limit 10R. At this time, the angle indicating the transmission / reception direction 11L of the radio wave 10 from the antenna 11 is measured and stored as the left limit angle.

Next, as shown in FIG. 3B, the direction of transmission / reception of the radio wave 10 is determined by the RFID tag 1 to be searched.
Swing to the right limit at which 2 can return a response. It is estimated that the RFID tag 12 to be searched exists on the right side of the left limit 10L and near the left limit 10L. At this time, the angle indicating the transmission / reception direction 11R of the radio wave 10 from the antenna 11 is measured and stored as the right limit angle.

The transmission / reception direction of the radio wave 10 can be made variable by mechanically changing the direction of the antenna 11, or can be made electrically variable using a phase array antenna in which a plurality of antenna elements are arranged. You can also. Alternatively, a plurality of antennas may be arranged in different directions of directivity, and the direction of transmission of the radio wave 10 may be switched stepwise by switching. When narrowing the range while changing the direction, it is preferable to narrow the range in which the radio wave 10 is transmitted.

As shown in FIG. 3 (3), the RF to be searched is
It is considered that the direction in which the ID tag 12 and the article 2 to which the RFID tag 12 is attached exists is the center of the transmission and reception directions 11L and 11R indicated by the measured left and right limit angles. Search direction 2 indicated by the angle representing this center
The direction indicator 23 emits light toward 3a. The user can identify the article 2 by looking at the direction of the light.
The direction instructing means 23 can issue an instruction by mechanically changing the light emitting direction using a laser pointer. When the laser pointer is used, the article 2 can be easily specified because the laser light irradiates the article 2 to be searched.

As the direction indicating means 23, a plurality of light emitting diodes (LEDs) can be arranged and selectively emit light to indicate a direction. In addition, liquid crystal display (LC
As in D), an arrow or the like can be displayed as an image. Further, the notification is not limited to the light instruction, and may be notified by voice or the like.

The transmission direction of the radio wave 10 can be changed in the vertical direction. Since the antenna 11 has directivity even in the vertical direction, if the direction of transmission and reception is changed electrically or mechanically, it is possible to narrow down the direction in which the RFID tag 12 to be searched exists in the vertical plane as well as in the horizontal plane. . In addition, since the RFID search device 1 is small, the user can change his or her posture to perform both the search in the horizontal plane and the search in the vertical plane.

FIG. 4 shows an overall procedure for searching for and specifying an article as shown in FIG. The procedure starts from step s1, and in step s2, data of the article 2 to be searched, that is, the RFID tag 1 attached to the article 2
2 is input to the existence determining means 21 of the RFID search device 1. In step s3, a read signal is transmitted over a wide range. As shown in FIG.
When 0 is received by a plurality of RFIDs 12, 13, 14,..., A plurality of data are given to the existence determining means 21 from the receiving circuit 20. The presence determination circuit 21 sets only the RFID tag 12 that transmits data that matches the data input in step s2 as a detection target in step s4.

In step s5, it is determined whether the RFID tag 12 to be detected exists. When it is determined that it does not exist, the process returns to step s3. If it is determined that the RFID tag 12 to be detected exists, the process proceeds to step s6, and the transmission range of the read signal is narrowed down. In step s7, the existence direction of the article 2 is calculated from the left and right limit angles, and in step s8, the direction of the calculated angle as the existence direction of the article 2 is indicated by emitting light. In step s9, the pointing direction by the light emission is searched, the article 2 is specified, and the procedure ends in step s10.

According to the present embodiment, a plurality of RFIs
Any RFID from D tags 12, 13, 14, ...
By searching the tag 12, the direction of the target RFID tag 12 can be indicated by light. Thus, even in the case where the RFID tag 12 is not visible to the user, such as an RFID tag attached to an article or a box, the direction in which the RFID tag 12 exists can be confirmed by the direction indicated by the light. By removing obstacles such as articles and boxes, the target RFID tag 12
Can be detected, so that the article 2 can be specified.

[0037]

As described above, according to the present invention, the RFID
The search device receives a reflected wave from the RFID with respect to the data-reading radio wave transmitted by the radio wave transmitting means in order to search for the location of the RFID, and determines the range of the space in which it is determined that the RFID is present. By changing the transmission range of Since the RFID exists in the narrowed-down space, if an instruction is given as the RFID search direction,
The direction in which the RFID exists can be known.

Further, according to the present invention, it is possible to indicate the direction in which the searched RFID exists in the light emission direction.

Further, according to the present invention, it is possible to indicate the direction in which the RFID whose stored data matches the preset data exists.

Further, according to the present invention, it is possible to narrow down the range in which the RFID is determined to exist by using the directivity of the antenna or the like, and to specify the search direction in which the RFID is present.

Further, according to the present invention, the presence of the RFID is determined as the first step of searching for an article to which the RFID is attached, and the search direction is specified by narrowing the range of the space where the RFID is present as the second step. If there are multiple articles, R
Even if you cannot see the FID directly,
The target article can be easily found in the ID search direction. When there are a plurality of RFIDs, the RFID can be identified by the data to be read, and the target article can be easily found.

Further, according to the present invention, it is possible to perform an angular displacement of the transmission direction of the radio wave to the left and right in a horizontal plane, and to search for articles in the left and right directions.

Further, according to the present invention, it is possible to vertically displace the transmission direction of the radio wave in the vertical plane and search for articles in the vertical direction.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a simplified electrical configuration of an RFID search device 1 according to an embodiment of the present invention in a plan view.

FIG. 2 is a plan view showing a schematic configuration of the RFID tags 12, 13, 14,... Of FIG.

FIG. 3 is a simplified plan view showing a state of searching for an article using the RFID search device 1 of FIG.

FIG. 4 is a flowchart illustrating a procedure for searching for an article using the RFID search apparatus 1 of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 RFID search device 2, 3, 4, ... Article 10 Radio wave 11, 32 Antenna 12, 13, 14, ... RFID tag 21 Presence judging means 22 Range narrowing means 23 Direction indicating means 31 Semiconductor integrated circuit chip

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G06K 17/00

Claims (7)

[Claims] 1. A radio wave is received, an operating power is generated from the received radio wave, a reflected wave changed according to data stored in the radio wave is generated, and a transmission source of the radio wave is generated. RFI to read stored data
D, an RFID search device that searches for an existing position, a radio wave transmitting unit that transmits a radio wave for reading data in a space in which it is presumed that the RFID is present, and a reflected wave from the RFID, Presence determining means for determining whether an RFID is present; and, when the presence determining means determines that the RFID is present, changing the transmission range of the radio wave by the radio wave transmitting means and determining that the RFID is present by the presence determining means. Means for narrowing down the range of the space to be defined, and the range of the space narrowed down by the range narrowing means,
A direction instructing unit for instructing a search direction of the RFID. 2. The RFID search device according to claim 1, wherein the direction indicating means indicates a search direction of the RFID by a light emission direction. 3. The RFID search device according to claim 1, wherein the RFID determination unit determines that the RFID exists only when data read from the RFID matches data set in advance. 4. The radio wave transmitting means is capable of changing the transmitting direction of the radio wave, and the range narrowing means is configured to change the transmitting direction of the radio wave from the radio wave transmitting means to narrow the range of the space. The direction instructing means includes a one-side limit angle at which the RFID is determined to be present when the transmission direction of the radio wave is changed to one side, and the presence of the RFID when the transmission angle of the radio wave is changed to the other side. The RFI according to any one of claims 1 to 3, wherein a search direction of the RFID is designated as a center with respect to the other-side limit angle determined to be the same.
D search device. 5. Receiving a radio wave, generating operating power from the received radio wave, generating a reflected wave changed according to data stored inside, and transmitting the reflected wave to a transmission source of the radio wave. RFI to read stored data
RFID that searches for the location of the article with D attached
A radio wave for reading data in a space of a space where it is presumed that an article with an RFID is present, receiving a reflected wave from the RFID, and determining whether or not the RFID is present. When it is determined that the RFID is present, the transmission range of the radio wave is changed to narrow down the range of the space where the RFID is determined to be present. A method for retrieving an article using an RFID, characterized by designating a search direction of the article. 6. The method of narrowing down the space includes a left limit angle at which the RFID can detect when the transmission direction of the radio wave is angularly displaced left and right in a horizontal plane, and a rightward angular shift. The article using RFID according to claim 5, wherein the displacement is determined by obtaining a right limit angle detectable by the RFID when the displacement is performed, and the center of the left limit angle and the right limit angle is indicated as the search direction. Search method. 7. The narrowing down of the space is performed by angularly displacing the transmission direction of the radio wave up and down in a vertical plane, and when detecting angular displacement upward, an upper limit angle at which RFID can be detected, and angular displacement downward. The RFI according to claim 5 or 6, wherein the search is performed by obtaining a lower limit angle that can be detected by the RFID, and the center of the upper limit angle and the lower limit angle is indicated as the search direction.
A method of searching for articles using D.