CN101183431A - Wireless communication system and wireless communication method - Google Patents
Wireless communication system and wireless communication method Download PDFInfo
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- CN101183431A CN101183431A CNA2007101701795A CN200710170179A CN101183431A CN 101183431 A CN101183431 A CN 101183431A CN A2007101701795 A CNA2007101701795 A CN A2007101701795A CN 200710170179 A CN200710170179 A CN 200710170179A CN 101183431 A CN101183431 A CN 101183431A
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Abstract
To perform communication between an antenna and an RFID tag securely. There are generated an interference area with an increased electric field level and an interference area with a decreased level, due to reflections at the upper and lower reflection plates. There are two reflective faces in each reflection plate, which are joined while being shifted from each other by 1/4 wavelength of the electromagnetic wave. Since the two reflective faces are being shifted, the interference area with a decreased electric field level moves on a production line according to a move of a dolly transporting the article. Thus, even if the RFID tag on the article passes through the interference area with a decreased electric field level in a first-half section, it comes to pass the point with recovered electric field level in a latter-half section. Therefore, the antenna can communicate with the RFID tag securely.
Description
Technical field
The present invention relates to a kind of wireless communication system and wireless communications method.
Background technology
There is a kind of wireless communication system of carrying out read/write communication between as RFID (radio frequency identifiers) label of wireless identification tag and antenna (for example, uncensored patent is announced 2003-295339 (patent documentation 1) referring to Japan).
Disclosed wireless communication system is the combination of RFID label, conveyer and antenna in patent documentation 1.The RFID label is attached on the article, and identification number of these article or the like is stored in wherein.This conveyer transmits RFID label article attached thereto, and antenna is carried out radio communication between the RFID label.
In above-mentioned wireless communication system, these article are towards at random direction.Therefore, this RFID label surface is at random direction.In addition, the level of the radiowave that on the RFID label, receives depend on the RFID label surface towards direction and change.
Therefore, in wireless communication system described above, this antenna is provided on the both sides of conveyer so that electromagnetic wave is radiated this RFID label from the both sides of conveyer, with all RFID label communications.
In addition, as wireless communication system, on production line, provide antenna, and on the side of production line, provide the plane reflection plate, so as with carry out radio communication towards all RFID label of different directions.
This plane reflection plate will be from the electromagnetic wave of the above antenna that provides towards the RFID tag reflection on production line.This antenna is radiated the RFID label with electromagnetic direct wave, and plane reflection plate reflection is from the electromagnetic wave of above antenna, thereby reflection wave is radiated the RFID label.Through thus, this antenna and RFID label are carried out radio communication.
Providing when electromagnetic wave from antenna reflect on the plane reflection plate in the wireless communication system of routine of above-described plane reflection plate in, this reflection wave scatters.Should overlapped and interference from the reflection wave of a plurality of baffle reflections.
In the time of each homophase of this reflection wave, the electromagnetic electric field level of this on interference point increases.When each of this reflection wave was anti-phase, the electromagnetic electric field level of this on interference point reduced.Therefore, near the front of reflecting plate, having the generation electric field level is that high point and generation electric field level is low point.
In conventional as mentioned above wireless communication system, with a plurality of plane reflection plates with the different elevations angle at transmission path, such as arranging abreast with such posture on path or the production line, that is, the reflection wave that moves on transmission path can be assembled towards the direction of article.In addition, a plurality of plane reflection plates are arranged in vertical direction (in the above with following on).Therefore, from the reflection wave phase mutual interference in vertical direction as mentioned above of adjacent planar reflecting plate.
The phenomenon that interferes with each other from the reflection wave of plane reflection plate depends on that the distance from the plane reflection plate produces the point with high electric field level and low electric field level.In the wireless communication system of routine, the reflecting surface of this plane reflection plate is set at respect on path or the production line uniform distance.Therefore, the electric field level of reflection wave is that high point and electric field level are that the zone of low point exists with respect to the direction that the RFID label towards article moves equably.
Therefore, even they move on transmission path, the electric field level of passing reflection wave is that the electric field level that the RFID label of low point never passes reflection wave is high point.Therefore, for realizing that the RFID label communication with the article of the point that passes the low electric field with reflection wave is impossible.Therefore, be impossible for the information that need to obtain from all RFID labels that on transmission path, pass through.
Summary of the invention
The purpose of a demonstration of the present invention provides a kind of wireless communication system, even under the environment of the phase mutual interference that reflection wave occurs, and it can be reliably and the RFID label executive communication of the article that move on transmission path.
In order to realize above-mentioned purpose, according to wireless communication system of the present invention is a kind of wireless communication system, its executive communication between attached to wireless identification tag on the article and antenna, these article transmit on transmission path, antenna is with the direction radiation of electromagnetic wave towards transmission path, this system comprises and being used for from the reflection of electromagnetic wave of the antenna reflecting plate to the wireless identification tag on transmission path, wherein
Reflecting plate comprises a plurality of reflecting surfaces along the length direction of transmission path, wherein
Reflecting surface is arranged on the position that is used to improve the interference range that produces owing to the interference between reflection wave.
In addition, can comprise according to wireless communication system of the present invention:
Attached to the wireless identification tag on the article of the transmission that transmits via transmission path, the electromagnetic wave of the radiation that it is used to inquire about by wireless response sends the identifying information of article of the transmission of storage;
Antenna, it sends electromagnetic wave and the identifying information of reception from the article of the transmission of wireless identification tag transmission; With
A plurality of reflecting plates with a plurality of reflecting surfaces that are used for reflection electromagnetic wave, it is placed along transmission path, reflection electromagnetic wave by this way, that is, the interference range that produces owing to the interference between electromagnetic reflection wave is moving according to the article of transmission on transmission path.
In addition, can comprise according to wireless communication system of the present invention:
Attached to the wireless identification tag on the article of the transmission that transmits via transmission path, it is used to inquire about the electromagnetic wave of radiation by wireless response, sends the identifying information of article of the transmission of storage;
Antenna, it sends electromagnetic wave and the identifying information of reception from the article of the transmission of wireless identification tag transmission;
Have a plurality of reflecting plates of the reflecting surface that is used for reflection electromagnetic wave, it is placed along transmission path; With
The reflecting plate control section, it controls a plurality of reflecting plates by this way, that is, and owing to interference range moving according to the article that transmit on transmission path of the generation of the interference between electromagnetic reflection wave.
In addition, can comprise according to wireless communication system of the present invention:
Attached to the wireless identification tag on the article of the transmission that transmits via transmission path, it is used to inquire about the electromagnetic wave of radiation by wireless response, sends the identifying information of article of the transmission of storage;
Antenna, it sends electromagnetic wave and the identifying information of reception from the article of the transmission of wireless identification tag transmission; With
The reflecting plate that is used for reflection electromagnetic wave along the transmission path placement, between the reflecting surface of reflecting plate and transmission path, has an angle that is arranged in such a way, that is interference range the moving according to the article that transmit on transmission path that produces owing to the interference between electromagnetic reflection wave.
By means of the present invention, might executive communication reliably between antenna and wireless identification tag.
Description of drawings
Fig. 1 is used to illustrate the structure of conduct according to the wireless communication system of the embodiment of first demonstration of the present invention, the side view of the RFID communication system architecture that uses in the logic manage system;
Fig. 2 is the anterior elevational view of RFID communication system shown in Figure 1;
Fig. 3 is an example that is used to illustrate the RFID label construction;
Fig. 4 illustrates a reflecting plate, and wherein Fig. 4 A is the example of watching from the Z direction, and Fig. 4 B is the example of watching from Y direction, and Fig. 4 C is the example of watching from X-direction;
Fig. 5 is used to the example that the interference range principle is provided by the reflecting plate that vertically provides is shown, and wherein Fig. 5 A is that example and Fig. 5 B that watches from X-direction is the example of watching from the Z direction;
Fig. 6 is used to illustrate conduct another structure according to the wireless communication system of the embodiment of first demonstration of the present invention, the side view of the RFID communication system architecture that uses in the logic manage system;
Fig. 7 is the anterior elevational view of RFID communication system shown in Figure 6;
Fig. 8 is the example that is used to illustrate according to the RFID communication system architecture of the embodiment of second demonstration of the present invention;
Fig. 9 is used to the example that the interference range principle is provided by the reflecting plate of the Fig. 8 that vertically provides is shown, and wherein Fig. 9 A is that example and Fig. 9 B that watches from X-direction is the example of watching from the Z direction;
Figure 10 is used to illustrate the structure of conduct according to another wireless communication system of the embodiment of second demonstration of the present invention, the side view of the RFID communication system architecture that uses in the logic manage system;
Figure 11 is the anterior elevational view of RFID communication system shown in Figure 10;
Figure 12 is the example that is used to illustrate the reflecting plate with three reflecting surfaces (N=3), and wherein Figure 12 A is the example of watching from the Z direction, and Figure 12 B is the example of watching from Y direction, and Figure 12 C is the example of watching from X-direction;
Figure 13 is an example that is used to illustrate the interference range that produces when using reflecting plate shown in Figure 12;
Figure 14 is used to illustrate the example that is suitable for the reflecting plate example, here reflecting plate has by changing two reflecting surfaces that angle connects, wherein Figure 14 A is the example of watching from the Z direction, Figure 14 B is the example of watching from Y direction, Figure 14 C is the example of watching from X-direction, and Figure 14 D is the skeleton view of this reflecting plate;
Figure 15 is used to illustrate two reflecting plates by flatly or the example of the suitable example that vertically moves, wherein Figure 15 A is the example of watching from Y direction, Figure 15 B is the example of watching from X-direction, and Figure 15 C is an example that is used to illustrate the reflecting plate control section that is used for mobile reflecting plate;
Figure 16 is used to illustrate the example of two reflecting plates with the suitable example of a plurality of angular movement, wherein Figure 16 A is the example of watching from Y direction, Figure 16 B is the example of watching from X-direction, and Figure 16 C is an example that is used to illustrate the reflecting plate control section that is used for mobile reflecting plate;
Figure 17 is the example that is used to illustrate the suitable example that single reflecting plate is rotated, wherein Figure 17 A is the example of watching from Y direction, Figure 17 B is the example of watching from X-direction, and Figure 17 C is an example that is used to illustrate the reflecting plate control section that is used to rotate reflecting plate;
Figure 18 is used to illustrate single reflecting plate by the example with the suitable example of rotating with respect to a certain angle [alpha] of the direction of motion of trolley, wherein Figure 18 A is the example of watching from Z-direction, Figure 18 B is the example of watching from Y direction, and Figure 18 C is the example of watching from X-direction; And
Figure 19 is an example that is used to illustrate the interference range that produces when using reflecting plate shown in Figure 18;
Figure 20 is the example of the reflecting plate that uses of an embodiment who is used for being illustrated in the 3rd demonstration of watching from Z-direction of the present invention.
Embodiment
Hereinafter will be by describe radio communications system with reference to the accompanying drawing of following according to the embodiment of the present invention's demonstration.In the embodiment of following demonstration, this wireless communication system is described to a RFID communication system that is used for the logic manage system.
(embodiment of first demonstration)
As depicted in figs. 1 and 2, the wireless communication system according to the embodiment of first demonstration of the present invention comprises RFID label 3, antenna 21 to 23, reflecting plate 4 (4-1 to 4-4), reader/writer 11 to 13, duplexer equipment 25, door sensor 26,27 and terminal 15.
To be loaded in as the article (not shown) of management objectives on the trolley 8, this trolley 8 moves on such as the transmission path 5 of path or production line, and is transferred to the target area along article transmission path 5.Suppose that trolley 8 X-directions (travel direction) shown in Figure 1 move on transmission path 5.
The embodiment of demonstration shown in Figure 1 comprises a plurality of antennas 21 to 23, and will distribute to the length direction (X-direction) that antenna 21,22 and 23 each electromagenetic wave radiation area E 1, E2 and E3 are arranged on transmission path 5.
Fig. 3 illustrates the configuration example of a RFID label 3.This RFID label 3 comprises dielectric basic unit 31, antenna 32 and label IC (integrated circuit) 33.
This antenna 32 is used for transmitting and receive data on electromagnetic wave.For example, it is made of dipole antenna, and is formed in the dielectric basic unit 31.The surface of dielectric described above basic unit 31 is antenna surface (antennas 32), and it plays the RFID label surface.
This label IC 33 comprises modulating/demodulating part (not shown), storer (not shown) or the like.This storer is used to store the article relevant information attached thereto with RFID label 3.As this information, this memory stores is used to identification number of discerning these article or the like.
This modulating/demodulating part is based on the data-modulated electromagnetic wave that is stored in the information in the storer, and demodulation is by the electromagnetic signal of antenna 32 receptions.
In case receive one irradiation of electromagnetic waves from antenna 21 to 23, this RFID label 3 is started by the electric energy that electromagnetic wave causes, and electron device, such as, aforesaid modulating/demodulating part and storer are started working.This RFID label 3 is attached on the article, and the article loading that will have a RFID label 3 that adheres to is on trolley 8.Therefore, how to depend on loaded with articles, the faces direction of the article that RFID label 3 is attached thereto is not necessarily pointed to certain direction.Therefore, there be the situation of the RFID label surface of this RFID label 3 towards random direction.
In the reception area proportional variation of the electromagnetic wave level that receives from antenna 21 on the RFID label 3 with electromagnetic reality the RFID label surface.When the electromagnetic wave level that receives improved, receiving became possible from the request signal (electromagnetic wave) of antenna 21 to 23 radiation.When the RFID label surface became facing to one of antenna 21 to 23 radiating surface, the reception area of this electromagnetic reality became maximum in the RFID label surface.Therefore, the electromagnetic wave level of reception becomes maximum.
In case receive request signal, this RFID label 3 is read information from the storer in label IC 33 in response, such as, identification number of these article or the like, and sends it to of antenna 21 to 23 via antenna 32.
This antenna 21 to 23 sends electromagnetic wave to give RFID label 3 with these wave radiation, therefore, with 3 executive communications of RFID label, and receives the information of identification number such as the article that send from RFID label 3 or the like.This antenna 21 to 23 is placed on the transmission path corresponding to the approximate position intermediate on the length direction (X-direction) of the reflecting plate of describing after a while 4.
As shown in Figure 1, this antenna 21 is with such posture arrangement, that is, in electromagenetic wave radiation district E1 electromagnetic wave towards the direction radiation in the front of trolley 8, and antenna 21 from the front of trolley 8 towards this electromagnetic wave of direction radiation of trolley 8.Then, this antenna 21 is by means of direct wave 6 and 3 executive communications of RFID label, and the RFID label surface is towards the direction of antenna 21 here.
As shown in Figure 2, this antenna 23 is with such posture arrangement, that is, trolley 8 is faced on this electromagenetic wave radiation surface downwards in electromagenetic wave radiation district E2.As shown in Figure 2, this antenna 23 is by means of direct wave executive communication between RFID label 3, here the RFID label surface is towards the direction of antenna 23, and simultaneously, via the reflection wave 7 that utilizes reflection on reflecting plate 4, by reflection wave 7 and 3 executive communications of RFID label, it arrives the RFID label surface of RFID label 3.
As shown in Figure 1, this antenna 22 is with such posture arrangement, that is, the electromagenetic wave radiation surface is towards the direction radiated electromagnetic wave at the back side of the trolley 8 that is arranged in electromagenetic wave radiation district E3, and antenna 22 from the back of trolley 8 towards this electromagnetic wave of direction radiation of trolley 8.Then, this antenna 22 is by means of direct wave 6 and 3 executive communications of RFID label, and the RFID label surface is towards the direction of antenna 22 here.
When terminal 15 provides control signal, this reader/writer 11 to 13 is repeatedly exported to request signal RFID label 3 via antenna 21 to 23.In the time of the response that exists from RFID label 3, antenna 21 to 23 is carried out and is communicated by letter with the RFID label 3 that responds this request signal.
This reflecting plate 4 will be from the electromagnetic wave of antenna 23 output towards Y direction the direction reflection communicate by letter with antenna 23 so that allow its RFID label surface to carry out towards the RFID of Y direction label 3.Should " Y direction " be cover horizontal direction or on trolley 8 with respect to the direction of RFID label 3 level of approximation directions, the direction of propagation of its expression reflected light 7, this reflected light 7 be from antenna 22 radiation on reflecting plate 4 towards the electromagnetic wave of the direction (Width of transmission path 5) of trolley 8 reflection.A plurality of reflecting plate 4-1 to 4-4 are arranged on the vertical direction on the side of transmission path 5 among the electromagenetic wave radiation district E2.This reflecting plate 4-1 to 4-4 arranges in the inclination mode, makes the reflection wave 7 that reflects on its reflecting surface move towards the direction of the RFID label on trolley 8.
Four the reflecting plate 4-1 to 4-4 that have in Fig. 1 and Fig. 2 illustrated.But the number of reflecting plate is not limited to this.The number of reflecting plate 4 and be based at the width of short transverse that the stacking of the RFID label of stacking 3 highly determines three-dimensionally.That is to say that if the piling height of this RFID label 3 becomes higher, the number of reflecting plate 4 increases, perhaps the width of reflecting plate 4 is expanded in short transverse.But, when becoming, the width of reflecting plate 4 equals electromagnetic wavelength, and perhaps 3/4 of this wavelength, 1/2 or the like the time, owing to produce resonance on reflecting plate 4, electromagnetic wave is attenuated, thereby the electric power of reflection wave is worsened.Therefore, to be set to the length longer than electromagnetic wavelength be desirable to the width of this reflecting plate 4.
By using metal-ware or the like with certain angle, make reflection wave 7 in the horizontal direction or the level of approximation direction move, with each of this reflecting plate 4-1 to 4-4 attached on wall face of factory or the like, perhaps attached to being provided at such as on pillar (not shown) on the side of the transmission path 5 of production line or the like.
Each of this reflecting plate 4-1 to 4-4 is the rectangular slab that is made of metal, the perhaps rectangular slab of making by synthetic resin, and the reflection of electromagnetic wave acting force is applied on it.
The reflecting plate 4-1 to 4-4 of the embodiment of first demonstration comprises a plurality of reflecting surfaces (on the electromagnetic position of reflection from antenna).A plurality of reflecting surfaces are arranged on have on the position of the different distance of transmission path 5, that is, be arranged on the different position of Width (Y direction) of transmission path 5.A plurality of reflecting surfaces are arranged in the length direction of reflecting plate 4-1 to 4-4, that is, are arranged in along the direction of transmission path 5 (X-direction in Fig. 1).This will be below by describing with reference to specific example.
Shown in Fig. 4 A to 4C, this reflecting plate 4 (each of reflecting plate 4-1 to 4-4) has two planes, the reflecting surface 4a and the 4b of peace.The reflecting surface 4a and the 4b of this reflecting plate 4 are arranged along the length direction (X-direction) of this transmission path 5.The length of supposing this reflecting surface 4a, the 4b that place along the length direction (X-direction) of this transmission path 5 is d1, d2, according in the Width of (Y direction) of transmission path 5 from the distance of transmission path 5, will be at this reflecting surface 4a among each the part d1 of this reflecting plate 4-1 to 4-4, with reflecting surface 4b in part d2 be arranged in move mutually be used to communicate by letter should electromagnetic position that is similar to 1/4 wavelength.In this case, two reflecting surface 4a and 4b are arranged continuously.But, these both can with provide betwixt certain apart from arrangement.
As mentioned above, two of this reflecting plate 4 reflecting surface 4a, 4b are to move the position of electromagnetic 1/4 wavelength that is used to communicate by letter mutually approximate.Therefore, the interference range that is formed by reflection wave 7 forms moving mutually with the Width (Y direction) at transmission path 5 on the position that is used at electromagnetic approximate 1/4 wavelength of communication on the transmission path 5, reflection wave 7 is respectively by reflecting surface 4a, the 4b of close reflecting plate 4 (4-1 and 4-2,4-3 and 4-4) reflection mutually in vertical direction.
Will as among Fig. 5 A, describe by especially with reflecting plate 4-3 and 4-4 as arranging contiguous mutually in vertical direction reflecting plate 4.But, its for reflecting plate 4-1 and 4-2 be in vertical direction mutually the situation of contiguous reflecting plate 4 also be the same.For adjacent reflecting plates 4-3 and 4-4 in vertical direction, when overlapping by the electromagnetic reflection wave 7 of the reflection of reflecting plate 4-3 with by the zone of electromagnetic reflection wave 7 on transmission path 5 of another reflecting plate 4-4 reflection, by interfering mutually in the zone of reflection wave (electromagnetic wave) 7 on transmission path 5 of adjacent reflecting plates 4-3,4-4 reflection, as representing with oblique line.
In phase mutual interference in phase in two zones of reflection wave 7 on transmission path 5 being reflected by reflecting plate 4-3,4-4, electric field level improves on that aspect.At the interference range H1 shown in Fig. 5 A is that zone and the interference range H2 that an electric field level is enhanced in the part d1 of transmission path 5 is a zone that electric field level is enhanced in the part d2 of transmission path 5.In Fig. 5 B, the part d1 of this transmission path 5 (X-direction) is corresponding to the length (X-direction) of reflecting surface 4a, and it constitutes the part of reflecting plate 4.
In anti-phase ground phase mutual interference in the zone of two reflection waves 7 on transmission path 5 of being reflected by reflecting plate 4-3,4-4, electric field level reduces on that aspect.At the interference range L1 shown in Fig. 5 A is that zone and the interference range L2 that an electric field level is reduced in the part d1 of transmission path 5 is a zone that electric field level is reduced in the part d2 of transmission path 5.In Fig. 5 B, the part d2 of this transmission path 5 (X-direction) is corresponding to the length (X-direction) of reflecting surface 4b, and it is the remainder of this reflecting plate 4.
This reflecting plate 4-1 to 4-4 is arranged abreast along transmission path 5 (X-direction), make interference range L1, L2, H1 and H2 form along the length direction (X-direction) of this transmission path 5.
In the embodiment of demonstration, this reflecting surface 4b that will be in part d2 has different distances with the Width (Y direction) that the reflecting surface 4a in part d1 is arranged in respect to this transmission path 5.That is to say that position relation mutual between reflecting surface 4b in part d2 and the reflecting surface 4a in part d1 moves approximate electromagnetic 1/4 wavelength that is used to communicate by letter with the Width (Y direction) along this transmission path 5.
Therefore, shown in Fig. 5 B, will move approximate electromagnetic 1/4 wavelength that is used to communicate by letter with interference range L2 in part d2 mutually at the Width (Y direction) of this transmission path 5 at the interference range L1 among the part d1.In addition, will move approximate electromagnetic 1/4 wavelength that is used to communicate by letter with interference range H2 in part d2 mutually at the Width (Y direction) of this transmission path 5 at the interference range H1 among the part d1.In addition, will move approximate electromagnetic 1/4 wavelength that is used to communicate by letter with interference range H1, H2 in part d1, d2 mutually at the Width (Y direction) of this transmission path 5 at interference range L1, L2 among part d1, the d2.Therefore, this interference range L1, L2 and interference range H1, H2 do not overlap each other at the length direction (X-direction) and the Width (Y direction) of this transmission path 5.
Therefore, even in the part d1 of transmission path 5, be in interference range L1 at the RFID label 3 on the trolley 8, here because the phase mutual interference that between reflection wave 7, produces, this electric field level is low, this reflection wave 7 is by the reflection of the reflecting surface of reflecting plate 4-3 and 4-4, and this RFID label 3 can not with antenna 23 executive communications, for at the mobile interference range L2 that avoid among the part d2s of transmission path 5 have low electric field of the RFID label 3 on the trolley 8 according to this trolley 8, and in by the zone of the reflection wave 7 of the reflecting surface 4b reflection of reflecting plate 4-3 and 4-4 execution to communicate by letter with antenna 23 be possible.
Now, investigate the electric field level in the zone in the part d2 of transmission path 5, existed in this RFID label 3 on the trolley 8 here.In the part d2 of this transmission path 5, the zone that exists in this RFID label 3 on the trolley 8 is a little zone of mutual degree of disturbance between reflection wave 7, perhaps zone that has the phase mutual interference hardly is as representing with oblique line in Fig. 5 A and Fig. 5 B.This electric field level therein is out and away greater than the electric field level in interference range L1.Therefore, the RFID label 3 on trolley 8 can be communicated by letter with antenna 21 to 23 by correctly carrying out among the part d2 that moves forward into this transmission path 5.
When in vertical direction width in each of reflecting plate 4-1 to 4-4 become equal electromagnetic wavelength or this wavelength 3/4,1/2 in, because the electromagnetic resonance that on reflecting plate 4-1 to 4-4, produces, this electric field level is attenuated, thereby the electric power of reflection wave is worsened.Therefore, each width in vertical direction of this reflecting plate 4-1 to 4-4 is set to aspect length longer than electromagnetic wavelength.
Each of reader/writer 11 to 13 reads the information such as the identification number of the article that received by antenna 21 to 23, and will be written to RFID label 3 about the information of these article via antenna 21 to 23.
In case the data that provide from terminal 15 are provided, each of this reader/writer 11 to 13 offers antenna 21 to 23 with the data that provide.On the contrary, when providing data via antenna 21 to 23, each of reader/writer 11 to 13 offers terminal 15 with the data that provide.
In the above description that provides, this reader/writer 11 to 13 is provided by the antenna 21 to 23 of respective number, and this reader/writer 11 to 13 is switched by the duplexer equipment 25 that is used to pass its switched antenna 21 to 23, communicates by letter with the RFID label 3 on trolley 8 to carry out.But it is not intended to be confined to this.As shown in Figure 6 and Figure 7, it provides single reader/writer 11 for a plurality of antennas 21 to 23 also is possible, and a plurality of antennas 21 to 23 are switched by single reader/writer 11, so that the antenna and the executive communication between the RFID label 3 on the trolley 8 of switching.Except the relation between reader/writer 11 and the antenna 21 to 23, Fig. 6 and the structure shown in Fig. 7 be identical at shown in Fig. 1 and Fig. 2 those.
Simultaneously, when the sensor strip 27a of door sensor 27 rotated, this door sensor 27 offered 25 1 trolleys of duplexer equipment by detection signal, and its expression trolley 8 moves to electromagenetic wave radiation district E3 from electromagenetic wave radiation district E2.In fact this door sensor 26 and 27 is made of to detect trolley 8 sensor strip 26a and 27a, and still, its structure is not limited to this.This door sensor 26 and 27 can be optically or electromagnetic ground detect the sensor of trolley 8 rather than its type that in fact detects.Key is to detect by means of those sensors whenever possible the position of trolley 8, can adopt any type of detection as door sensor 26 and 27.
According to the position of the trolleys 8 that detected by door sensor 26 and 27, this duplexer equipment 25 switches in the antenna 21 to 23 that covers communication among electromagenetic wave radiation district E1, E2 that trolley 8 enters or the E3 selectively.
In the time of among trolley 8 is in electromagenetic wave radiation district E1, this trolley does not offer duplexer equipment 25 from door sensor 26 and 27 by detection signal.Therefore, this duplexer equipment 25 is selected reader/writer 11 and antenna 21.
When trolley by detection signal when door sensor 26 provides, these duplexer equipment 25 switched antennas 21 are to antenna 23, and switch reader/writer 11 to reader/writer 13.
When trolley by detection signal when door sensor 27 provides, these duplexer equipment 25 switched antennas 23 are to antenna 22, and switch reader/writer 13 to reader/writer 12.
This terminal 15 comprises ROM (ROM (read-only memory), not shown), RAM (random access memory, not shown), CPU (CPU (central processing unit), not shown), HDD (hard disk drive, not shown) or the like, and these terminal 15 control entire RF ID communication systems.
This terminal 15 repeatedly offers control signal one of the reader/writer 11 to 13 switched by duplexer equipment 25, make reader 11 and antenna 21, reader/writer 12 and antenna 22, perhaps reader/writer 13 and antenna 23 and 3 executive communications of RFID label.
When data provided from of reader/writer 11 to 13, this terminal 15 sent the data that provide to server 17 via network 16 (it is a communication network).
This server 17 is collected the data that obtain by communicating by letter with RFID label 3, and with its form storage with database.This server 17 uses the data of storage to be used in factory's production control or the like.
Next operation according to the RFID communication system of the embodiment of first demonstration will be described.
As shown in Figure 1, trolley 8 moves to X-direction from-X-direction on transmission path 5.In the time of among trolley 8 is in electromagenetic wave radiation district E1, this trolley does not offer duplexer equipment 25 from door sensor 26 and 27 by detection signal.Therefore, this duplexer equipment 25 is selected reader/writer 11 and antenna 21.
This terminal 15 offers antenna 21 via reader/writer 11 with control signal.When this control signal when terminal 15 provides, this reader/writer 11 is sent to RFID label 3 via the electromagnetic wave of antenna 21 with a request signal.This reader/writer 11 is repeatedly sent this request signal from antenna 21.
The radiating surface of this antenna 21 is towards the front of the trolley on transmission path 58, and the electromagnetic wave that receives from antenna 21 towards the RFID label 3 of Z-direction shown in Figure 1 of its RFID label surface.
Receive these electromagnetic these RFID label 3 response request signals and from the storer of label IC 33, read identification number of article or the like, and provided it to antenna 32.Antenna 32 transmits identification number or the like on electromagnetic wave.
This antenna 21 receives these electromagnetic waves, and reader/writer 11 reads identification number of these article or the like, and identification number of reading or the like is offered terminal 15.
When trolley 8 moves and to the sensor strip 26a energy supply of door sensor 26 time, this sensor strip 26a rotates, and this door sensor 26 offers duplexer equipment 25 with trolley by detection signal.
Pass through detection signal in case the trolley that provides from door sensor 26 is provided, this duplexer equipment 25 judges that trolleys 8 move to electromagenetic wave radiation district E2 from electromagenetic wave radiation district E1.These duplexer equipment 25 switched antennas 21 are to antenna 23, and switching reader/writer 11 is to reader/writer 13.
When terminal 15 provides control signal, this reader/writer 13 is repeatedly launched a request signal (electromagnetic wave) via antenna 23.Among the electromagnetic wave of antenna 23 emissions, will in a district, not pass to the directly emission of the direction towards RFID label 3 from antenna 23 of this electromagnetic wave of reflecting plate 4 positions as direct wave, its RFID label surface is upwards facial on platform track 8.By means of this, between antenna 23 and RFID label 3, pass through the direct wave executive communication.
Among the electromagnetic wave of antenna 23 radiation, the electromagnetic wave that arrives reflecting plate 4 respectively by reflecting surface 4a, the 4b of reflecting plate 4 in the horizontal direction or level of approximation direction (Y direction) towards 3 reflections of the RFID label on trolley 8, so that propagate towards the direction of the RFID label 3 on trolley 8.
In electromagnetic radiation district E2, use the reflection wave except direct wave to carry out with various forms at antenna 23 and the communication between the RFID label 3 on the trolley 8.To describe these forms in detail.
When passing reflecting plate 4-3,4-4, the RFID label 3 on trolley 8 (that is to say, in the part d1 of transmission path 5) the zone of reflecting surface 4a in, interfere with each other towards the reflection wave 7 of the direction reflection of horizontal direction or level of approximation by the reflecting surface 4a of adjacent reflecting plates 4-3 and 4-4, thereby the interference range L1 that interference range H1 that the electric field level that produces reflection wave 7 improves and the electric field level that produces reflection wave 7 reduce.
When at the RFID label 3 on the trolley 8 be on a zone except that interference range H1 and interference range L1 in, antenna 23 and at the RFID label on the trolley 83 by utilizing the reflection executive communication on the reflecting surface 4a at reflecting plate 4-3 and 4-4.
When at the RFID label 3 on the trolley 8 be in interference range L1 in, it is lower than being used for the necessary level of executive communication that this electric field level becomes.Therefore, in interference range L1, will not carry out in the mobile zone (that is to say the part d2 of transmission path 5) that moves to the reflecting surface 4b of reflecting plate 4-3,4-4 of the RFID label 3 on trolley 8 of communicating by letter between the antenna 23 according to trolley 8.
Do not carrying out under the situation of part d2 that RFID label 3 on the trolley 8 of communicating by letter with antenna 23 enters transmission path 5, by adjacent reflecting plates 4-3,4-4 in the horizontal direction or the environment of the reflection wave 7 of level of approximation direction reflection be different under the situation of the part d1 of transmission path 5 those.That is to say, this reflecting surface 4b be in the Width of transmission path 5 with respect to the reflecting surface 4a of reflecting plate 4-3,4-4 in the part d1 of transmission path 5, by moving the position of approximate electromagnetic 1/4 wavelength that is used to communicate by letter.
Therefore, interference range L2 that will produce in the part d2 of transmission path 5 and interference range H2 move approximate electromagnetic 1/4 wavelength that be used to communicate by letter with interference range H1 at the Width of transmission path 5 with respect to the interference range L1 that produces in the part d1 of transmission path 5.
Under the ripple environment of above-mentioned reflection wave 7, even can not communicate by letter with antenna 23 because of the interference range L1 in the part d1 of this transmission path 5 at the RFID label on the trolley 83, when being moved to the part d2 of transmission path 5, RFID label 3 on trolley 8 can be avoided interference range L2, here electric field level is reduced in the part d2 of transmission path 5, and comes by reflecting plate 4-3,4-4 in the horizontal direction or the zone of the reflection wave 7 of level of approximation direction reflection.
Therefore, even not executive communication between RFID label 3 on the trolley 8 and antenna 23 in the part d1 of transmission path 5, when among the part d2 that enters transmission path 5 time, can executive communication between RFID label 3 and antenna 23 by using reflecting plate 4-3,4-4 (via the reflection wave 7 of the propagation of reflecting) by reflecting plate 4-3,4-4.
These RFID label 3 response request signals that received this reflection wave 7 are read identification number of article or the like from the storer of label IC 33, and provide it to antenna 32.Antenna 32 transmits identification number or the like on electromagnetic wave.This electromagnetic wave reflects on reflecting plate 4 and arrives antenna 23.
This antenna 23 receives this electromagnetic wave, and reader/writer 11 reads in identification number in the RFID label 3 or the like.Then, this reader/11 offer terminal 15 with identification number of reading or the like.
When trolley 8 moves and to the sensor strip 27a energy supply of door sensor 27 time, this sensor strip 27a rotates, and this door sensor 27 offers duplexer equipment 25 with trolley by detection signal.
Pass through detection signal in case the trolley that provides from door sensor 27 is provided, this duplexer equipment 25 judges that trolleys 8 move to electromagenetic wave radiation district E3 from electromagenetic wave radiation district E2.These antenna switching equipment 25 switched antennas 23 are to antenna 22, and switching reader/writer 13 is to reader/writer 12.
This antenna 22 repeatedly sends the electromagnetic wave of this request signal to this RFID label 3.The RFID surface receives this electromagnetic wave towards the RFID of Z-direction label 3 as direct wave 6.
These RFID label 3 response request signals that received this direct wave 6 are read identification number of article or the like from the storer of label IC 33, and provide it to antenna 32.Antenna 32 transmits identification number or the like on electromagnetic wave.
This antenna 22 receives these electromagnetic waves, and this reader/writer 12 reads identification number of these article or the like, and identification number of reading or the like is offered terminal 15.
Therefore, during trolley 8 passes electromagenetic wave radiation district E1 to E3, each of antenna 21 to 23 with towards the RFID of Z-direction label 3, with from X-direction (front of trolley 8) towards the RFID of Y direction label 3, and from the back side of trolley 8 towards 3 executive communications of the RFID of Z-direction label.In this way, this antenna 21 to 23 and all RFID label 3 executive communications.
When trolley 8 further leaves from the electromagenetic wave radiation district E3 of antenna 22, the sign off between RFID label 3 and antenna 21 to 23.Identification number of these article that this terminal 15 will provide or the like sends server 17 to via network 16.
In the embodiment of first demonstration, to be placed on the position that has from the different distance of this transmission path (that is to say that the Width (Y direction) that will be arranged in transmission path 5 along a plurality of reflecting surfaces of the length direction arrangement of transmission path 5 moves approximate electromagnetic 1/4 wavelength that is used to communicate by letter mutually) along the reflecting surface of this reflecting plate of the length direction arrangement of transmission path 5.Therefore, though the RFID label on the trolley in the Qian Ban district of transmission path 5 (part d1), become can not with this antenna communication, be possible in the RFID label on the trolley and the executive communication in the later half district of transmission path 5 (part d2) of this antenna.Therefore, executive communication between the RFID label on the trolley and this antenna reliably.
Especially, in electromagenetic wave radiation district E2, owing in the part d1 of transmission path 5 and d2, alternately occur along transmission path 5 at the interference range that produces interference range by the interference between the reflection wave 7 of reflecting plate 4 reflection and have a high electric field level with low electric field level.
When trolley 8 was proal on transmission path 5, the interference range L1 that has low electric field level in part d1 arrived the position of moving 1/4 wavelength at the Width of hop 5 as the interference range L2 that has the electric field level that weakens in part d2.
Therefore, even RFID label 3 passes the area L 1 with low electric field level, and can not receive reflection wave 7, because the point that this label 3 recovers by electric field level inevitably, this RFID label 3 can receive reflection wave 7 for certain.Therefore, this antenna 23 can be reliably and all RFID label 3 executive communications.
In addition, the radiating surface of this antenna 21,22 is towards different directions, and in addition, this antenna 23 is given RFID label 3 by using reflecting plate 4 with electromagenetic wave radiation.Therefore, even a plurality of RFID labels 3 are dispersed in the wide scope three-dimensionally, and this RFID label surface is towards at random direction, and this antenna 21 to 23 can be reliably and all RFID label 3 executive communications.
Because duplexer equipment 25 can be based on the position switched antenna 21 to 23 of the trolley 8 that passes through on production line 5, by the following RFID label 3 that moves according to trolley 8 and a plurality of antennas 21 to 23, executive communication between antenna 21 to 23 and RFID label 3 reliably.
(second embodiment)
The reflecting plate that provides on its both sides along transmission path is provided RFID communication system according to the embodiment of second demonstration.
As shown in Figure 8, the RFID communication system according to the embodiment of second demonstration comprises RFID label 3, antenna 21 to 24, reflecting plate 4-1 to 4-8 and reader/writer 11 to 14.
Those of the embodiment of this RFID label 3, antenna 21 to 23, reflecting plate 4-1 to 4-4 and reader/writer 11 to 13 and first demonstration are identical.In the embodiment of second demonstration, this antenna 24, reflecting plate 4-5 to 4-8 and reader/writer 14 have been added.
When transmission path 5, when being wide, perhaps,, may form the zone that a reflection wave 7 can not arrive on a side if this reflecting plate 4 only provides when the electromagnetic level of transmission from antenna 23 radiation when being low such as the width of production line.
Even under these circumstances, by increasing an antenna (antenna 24) and reflecting plate 4 (arranging reflecting plate 4-1 to 4-8 along transmission path 5 on its both sides), antenna 21 to 24 might be reliably and 3 executive communications of RFID label.
This antenna 24 is used for by communicating by letter with RFID label 3 via the reflection wave 7 towards the direction radiated electromagnetic wave of reflecting plate 4-5 to 4-8.This antenna 24 is parallel to antenna 21 to 23 is arranged on the transmission path 5, and this radiating surface is towards the direction inclination of reflecting plate 4-5 to 4-8 side.
Each of this reflecting plate 4-5 to 4-8 is the plate that is equivalent to reflecting plate 4-1 to 4-4.That is to say that each of this reflecting plate 4-5 to 4-8 is the rectangular slab that is made of metal, the perhaps rectangular slab of making by synthetic resin, the reflection of electromagnetic wave acting force is applied on it.Arrange this reflecting plate 4-5 to 4-8 by this way, that is, reflecting surface in the part d1 of transmission path 5 on it and the reflecting surface in the part d2 of transmission path 5 move approximate electromagnetic 1/4 wavelength that is used to communicate by letter mutually.
This reflecting plate 4-5 to 4-8 is similar on the position of and reflecting plate 4-1 to 4-4 symmetry approximate with respect to production line 5 and is arranged on the transmission path 5 with reflecting plate 4-1 to 4-4 with paralleling.Mainly, this reflecting plate 4-5 to 4-8 reflection is from the electromagnetic wave of antenna 24.
On each both sides with this reflecting plate 4-1 to 4-8 attached to the face-to-face metope of factory or the like, perhaps for example, by using metal-ware or the like, by with transmission path 5, such as, be inserted in therebetween production line mutually in the face of being provided on the pillar on the both sides.
This antenna 23 is by utilizing reflection wave 7 and RFID label 3 executive communications on the right half part of trolley 8, and this antenna 23 is by utilizing reflection wave 7 and RFID label 3 executive communications on the left-half of trolley 8.
This reader/writer 14 is identical with reader/writer 11 to 13, and it reads the information such as the identification number of the article that received by antenna 24, and will be written to RFID label 3 about the information of these article.
Next operation according to the RFID communication system of the embodiment of second demonstration will be described.
When trolley 8 moves from electromagenetic wave radiation district E1, and to the sensor strip 26a energy supply of door sensor 26 time, this door sensor 26 offers duplexer equipment 25 with trolley by detection signal.
Pass through detection signal in case the trolley that provides from door sensor 26 is provided, this duplexer equipment 25 judges that trolleys 8 move to electromagenetic wave radiation district E2 from electromagenetic wave radiation district E1.These duplexer equipment 25 switched antennas 21 arrive antenna 23,24 then, and switch reader/writer 11 to reader/ writer 13,14.
Fig. 9 A is that the example and Fig. 9 B that watch from X-direction are the examples of watching from Z-direction.Fig. 9 A and 9B illustrate this state, and wherein electromagnetic wave is to be spread by per two the reflecting plate 4-1 to 4-8 that are placed on the both sides, and reflection wave separately 7 interferes with each other.
From antenna 23 or antenna 24 electromagnetic each by reflecting plate 4-1 to 4-8 reflection and diffusion.Among reflecting plate 4-1 to 4-4, overlap each other by the reflection wave 7 of last lateral reflection plate 4 reflections and the reflection wave 7 that reflects by following lateral reflection plate 4, thereby produce an interference range.
In addition, among reflecting plate 4-5 to 4-8, overlap each other by the reflection wave 7 of last lateral reflection plate 4 reflections and the reflection wave 7 that reflects by following lateral reflection plate 4, thereby produce an interference range.
Fig. 9 A illustrate one when last lateral reflection plate 4 be reflecting plate 4-3,4-7, and the example of watching from X-direction when down lateral reflection plate is reflecting plate 4-4,4-8.Fig. 9 B illustrates an example of watching from Z-direction.
The interference range that overlaps each other by the reflection wave 7 of reflecting plate 4-3 reflection with by the reflection wave 7 of reflecting plate 4-4 reflection with one of the region representation shown in the oblique line in Fig. 9 A and one are by the reflection wave 7 of reflecting plate 4-7 reflection and the interference range that overlapped each other by the reflection wave 7 of reflecting plate 4-8 reflection.
In addition, be illustrated in interference range among part d1 and the d2 in each of interference range H1 shown in Fig. 9 A and the 9B and H2, wherein because homophase disturbs, electric field level is enhanced.In addition, each of interference range L1 and L2 is illustrated in the interference range among part d1 and the d2, and wherein owing to anti-phase interference, electric field level is reduced.This interference range H1, H2, L1 and L2 are produced abreast along transmission path 5.
Among the RFID of Y direction label 3, the RFID label 3 that has passed the zone except that the interference range L1 in the part d1 of Fig. 9 B receives the reflection wave 7 of the reflecting plate 4-1 to 4-8 among the comfortable part d1 at the RFID label surface.
In part d1, to work as the interference range L1 that produces when the reflection wave 7 that is reflected by reflecting plate 4-3,4-4 overlaps each other, be arranged on reflecting plate 4-5 to the 4-8 side on the transmission path 5 with the interference range L2 that in part d2, produces, that is, be arranged in the zone of moving mutually in the Width (Y direction) of transmission path 5.Therefore, those interference ranges do not overlap each other at the length direction (X-direction) of transmission path 5.
In part d1, by reflecting plate 4-1 to 4-4 side and the RFID label 3 that passes interference range L1 this zone in part d2 of moving through according to trolley 8, here this electromagnetic electric field level is enhanced (that is to say, pass except that interference range L2 should zone).
Therefore, even this RFID label 3 is by the interference range L1 on reflecting plate 4-1 to 4-4 side, and by the interference range L1 on reflecting plate 4-5 to 4-8, and can not receive reflection wave 7 therein, because label 3 is by having this point in the interference range that improves electric field level in part d2, it is possible that RFID label 3 receives reflection wave 7.
In the embodiment of second demonstration, on the both sides of production line 5, provide this antenna 23,24 and reflecting plate 4-1 to 4-8.
Therefore, even when the width of transmission path 5 when being wide, when ought be low perhaps from the electromagnetic level of antenna 23 radiation, the result forms a zone, wherein reflection wave 7 can not only arrive by means of the reflecting plate 4-1 to 4-4 on a side, comes to become possible with 3 executive communications of RFID label reliably by means of antenna 23 and 24.
(the 3rd embodiment)
The embodiment of the 3rd demonstration shown in Figure 20 illustrates a kind of situation, and the reflecting surface 4a that wherein forms on reflecting plate 4-1,4-2, the layout of 4b are changed.
In the embodiment 3 of the 3rd demonstration shown in Figure 20, reflecting surface 4a, the 4b that forms on reflecting plate 4-1,4-2 is with an angle of elevation alpha arrangement with respect to vertical direction.It is desirable that reflecting surface 4a, the 4b that forms on reflecting plate 4-1,4-2 is arranged on the adjacent areas (that is to say, be arranged in this zone that is arranged in vertical direction contiguously).In addition, the shape that the reflecting surface 4a that will form on reflecting plate 4-1,4-2,4b are combined into taper is desirable, and its direction towards article on transmission path is extended.
In addition, reflecting surface 4a, 4b are desirable with respect to the angle of elevation alpha of vertical direction in the scope of 1/2 to 1/4 wavelength of the frequency of using.But, be not limited to this.In the zone of the transmission path that these article transmit thereon, not only there is the electromagnetic wave that is used to communicate by letter from aerial radiation, and existence is used to control electromagnetic wave and the harmonic wave thereof that trolley moves on transmission path, and these ripples may be reciprocally interfering with each other, and reflected by reflecting surface 4a, 4b.Therefore, even the angle of elevation alpha of reflecting surface 4a and 4b is set in a laboratory, its numerical value only is an ideal value.Therefore, be necessary to consider the electromagnetic state in the actual zone that this reflecting surface is provided thereon, make the angle of elevation alpha of reflecting surface 4a and 4b be not limited to value described above.
Result as a test, be by in reflecting surface 4a, the 4b reflection of the embodiment of the 3rd demonstration shown in Figure 20 wherein from the electromagnetic wave of this antenna 23, it is found that, this reflecting surface 4a, the 4b of the embodiment of the 3rd demonstration can reduce the zone that electric field intensity becomes very little on transmission path, and on transmission path, distribute electric field equably, simultaneously it is maintained until the essential intensity of communication.
The effect that is obtained by the embodiment of the 3rd demonstration is used as experimental result to be confirmed, and does not still carry out its technical Analysis.But, according to estimates, based on there is a kind of phenomenon in the similar principle of the principle of tapered slot antennas, and reflecting surface 4a, 4b allow electric field to be evenly distributed in the very wide scope in zone with the expansion of angle [alpha], maintains electric field on the transmission path simultaneously to the necessary intensity of communication.Figure 20 illustrates this situation, wherein reflecting surface 4a and 4b is arranged on the side of transmission path.But this layout is not limited to this.Reflecting surface 4a and 4b shown in Figure 20 can be arranged on the both sides of transmission path.
In the above description that provides, this reader/writer 11 to 14 is provided by the antenna 21 to 24 of respective number, and this reader/writer 11 to 14 is switched by duplexer equipment 25, is used to switch and passes antenna 21 to 24 with executive communication between the RFID label 3 on the trolley 8.But it is not intended to be confined to this.As shown in Figure 10 and Figure 11, it also is possible providing single reader/writer 11 for a plurality of antennas 21 to 24, and a plurality of antennas 21 to 24 are switched by single reader/writer 11, so that the antenna and the executive communication between the RFID label 3 on the trolley 8 of switching.Except the relation between reader/writer 11 and the antenna 21 to 24, Figure 10 and the structure shown in Figure 11 be identical at shown in Fig. 8 and Fig. 9 those.
Can consider to be used to embody various form of the present invention, and its structure is not limited to as mentioned above those of embodiment of demonstration.
For example, the number of the reflecting surface of this reflecting plate 4 of placing along the length direction (X-direction) of transmission path 5 is not limited to two, but can be a plurality of.When there are two reflecting surfaces in this reflecting plate 4, these two reflecting surfaces are arranged in the Width (Y direction) of transmission path 5 in the position of moving electromagnetic approximate 1/4 wavelength that is used to communicate by letter mutually.This reflecting plate 4 can have the reflecting surface that (that is to say that N reflecting surface: N is a natural number, N 〉=3) more than three.Under the sort of situation, a plurality of reflecting surfaces are arranged in a spacing on the position of moving mutually at the Width (Y direction) of transmission path 5, this spacing is divided by (N-1), that is, with 1/4{1/ (N-1) by electromagnetic approximate 1/4 the length that is used to communicate by letter } spacing obtain.
When this reflecting plate 4 each reflecting plate 4 vertically have a N reflecting surface in, according to separately surface produce on N the different position by on the reflection wave 7 of lateral reflection plate 4 reflections and the interference range that overlaps each other by the reflection wave 7 of lateral reflection plate 4 reflections down.
Figure 12 mode as an example illustrates the situation of the reflecting plate 4 with N=3.In this case, as shown in figure 13, on three different positions, produce this interference range L1, L2, L3, H1, H2 and H3.In the part d1 of transmission path 5, this reflecting surface 4a is arranged among the part d2 of Width of transmission path 5 and moves electromagnetic approximate 1/8 wavelength that is used to communicate by letter from reflecting surface 4b, and from position that reflecting surface 4c among the part d3 of the Width of transmission path 5 moves electromagnetic approximate 1/4 wavelength that is used to communicate by letter.
Therefore, interference range L1 in part d1 and H1 (it is to produce when the reflection wave 7 by the reflecting surface 4a reflection of adjacent reflecting plates 4 in vertical direction interferes with each other) not with interference range L2 and H2 (it is to produce when the reflection wave 7 by the reflecting surface 4b reflection of adjacent reflecting plates 4 in vertical direction interferes with each other) in part d2, perhaps interference range L3 in part d3 and H3 (it is to produce when the reflection wave 7 by the reflecting surface 4c reflection of adjacent reflecting plates 4 in vertical direction interferes with each other) are overlapping.Therefore, even can not executive communication in of several sections, might executive communication in other part.
By N aforesaid reflecting surface is provided, the point with low electric field level can disperse.Therefore, might shorten the distance that the RFID label 3 on trolley 8 becomes and can not communicate by letter.
In addition, this reflecting plate 4 can be to form by connect a plurality of reflecting surfaces on different mutually angles, shown in Figure 14 A-14D.
This reflecting plate 4 is arranged on the side of transmission path 5, two reflecting surface 4a placing at length direction (X-direction) and the angle of 4b is differed from one another, as shown in figure 14 with respect to Z-direction.
By means of structure shown in Figure 14, interference range L1 and L2 with low electric field level produce when the reflection wave by the reflecting surface reflection of adjacent reflecting plates 4 vertically interferes with each other, and it is (short transverse: Z-direction) produce on the position of moving mutually in vertical direction.Therefore, might avoid Width at transmission path 5 described above (Y direction) and short transverse (Z-direction) among both, interference range L1, the L2's between part d1 and d2 is overlapping.
But when the angle of two reflecting surfaces was too big, this reflection wave 7 became and moves from RFID label 3.Therefore, consider that the angle of two reflecting surfaces is enough at about 10 degree, and it is arranged on that value.
In the embodiment of first and second demonstration, by the interference range that the reflecting surface improvement of arranging reflecting plate 4 produces owing to the interference between reflection wave, this reflecting surface reflects the electromagnetic wave from antenna on the position of determining by the electromagnetic wavelength of considering to be used to communicate by letter.But it is not limited to this.As Figure 15 to shown in Figure 17, by make the position of reflecting surface be adjustable also be can improve because the interference range that the interference between reflection wave produces.
In Figure 15, this reflecting surface 4a and 4b reciprocally move by the Width (Y direction) of a reflecting plate control section 40 at transmission path 5, are kept for the electromagnetic distance that is similar to 1/4 wavelength of communicating by letter simultaneously.In Figure 16, this reflecting surface 4a and 4b are reciprocally moved by reflecting plate control section 40 in the Z-Y quadrant, that is to say,, be kept for the distance of electromagnetic approximate 1/4 wavelength of communicating by letter simultaneously at the direction and the Width (Y direction) of the inclination of transmission path 5.
By means of embodiment, because interference range L1, L2, H1 and H2 that the interference between the reflection wave on the transmission path 5 produces can move at the Width of transmission path 5 and the direction of inclination in the demonstration shown in Figure 15 and Figure 16.Therefore, for example, depend on the stress state of these article on trolley 8, might change by the electromagnetic wave zone of reflection wave 7 for RFID label 3 radiation of the article on the side that is carried in trolley 8 distortedly.Be not limited to the stress state that is used to handle these article in the structure shown in Fig. 15 and Fig. 16.When it need change because in interference range L1, L2, H1 and the H2 that the interference between reflection wave 7 produces, those structures can adopt as required.
As shown in figure 17, it also is possible for making reflecting plate 4 reciprocally rotating around transverse axis (X-direction).In Figure 17, illustrate this reflecting plate 4 by means of single reflecting surface.But this reflecting plate 4 can have a plurality of reflecting surfaces, and this reflecting surface can be arranged in the position of moving electromagnetic approximate 1/4 wavelength that is used to communicate by letter mutually.
Under the situation of Figure 17, the rotation angle of this reflecting plate 4 is enough at about 10 degree.This reflecting plate control section 40 is arranged on about 10 degree with the rotation angle of reflecting plate 4, and rotates this reflecting plate 4.Under the situation shown in Figure 15 and Figure 16, may only provide single reflecting plate 4 equally therein.
By means of in the structure shown in Figure 15 to Figure 17, might be by means of the executive communication between RFID label on the trolley and antenna of the reliable in structure except that above-mentioned structure ground, will reflect reflecting surface from the electromagnetic reflecting plate 4 of antenna here and be arranged in the definite position of electromagnetic wavelength by considering to be used to communicate by letter.
In the embodiment of first and second demonstration, when will reflect reflecting surface from the electromagnetic reflecting plate 4 of antenna and be arranged in by the electromagnetic wavelength considering to be used to communicate by letter locational, for the whole length of reflecting plate in length direction (X-direction), the spacing of a plurality of reflecting surfaces is set with the size corresponding to electromagnetic approximate 1/4 wavelength that is used to communicate by letter.But it is not limited to this.Shown in Figure 18 A to 18C, the angle [alpha] that can preset with the travel direction with respect to trolley 8 is arranged this reflecting plate 4.This angle [alpha] is set to electromagnetic 1/4 wavelength of α=arctan[()/H], and move this reflecting plate 4 obliquely, and be provided with the distance of electromagnetic 1/4 wavelength.H is the length (d1+d2) of reflecting plate 4 in length direction (X-direction).
When this reflecting plate 4 is provided with the angle [alpha] with respect to the travel direction of trolley 8, as shown in figure 19, since by on lateral reflection plate 4 reflection reflection wave 7 and be parallel to reflecting plate 4 and produce obliquely by the interference range L1 that the interference between the reflection wave 7 of lateral reflection plate 4 reflections down produces with respect to the direction of motion of trolley 8.
Therefore, when trolley 8 travels forward on transmission path 5 and crosses interference range L1, and the RFID label 3 on the trolley 8 become in interference range L1, can not communicate by letter in, by after this interference range L1, this RFID label 3 becomes and can communicate by letter.As describing, when arranging reflecting plate 4 with respect to the angle [alpha] of the direction of motion of trolley 8 when, the distance that can not communicate by letter that becomes of the RFID label 3 on trolley 8 can be shortened.
Go for replacing reflecting plate 4 according to structure according to the embodiment of first and second demonstration at this reflecting plate 4 of the embodiment of the demonstration shown in Figure 15 to Figure 18.
In the embodiment of demonstration described above, these duplexer equipment 25 switched antennas 21 to 23.But the radiation areas of each in antenna 21 to 23 do not overlap each other, and do not produce when crosstalking, and are unnecessary for duplexer equipment 25 switched antennas 21 to 23.Therefore, in the case, provide duplexer equipment 25 and door sensor the 26, the 27th, unnecessary.
The present invention is not limited to the RFID communication system that is used for the logistics management system.For example, it can be used for: be used to manage the parts of transmission on belt conveyer, trolley or the like and the system of equipment; Be used for the system of managed storage at the parts and the equipment of factory, warehouse, allocated channel or the like; Use the special-purpose recognition system of RFID label; Enter/withdraw from management system; Use the animal identification system of RFID label; And animal management system.
The application based on the Japanese patent application No. No.2006-160694 that requires from June 9th, 2006 application, with the rights and interests of the right of priority of the Japanese patent application No. No.2007-130849 of on May 16th, 2007 application, it is open to be combined in this as reference data integral body.
Claims (15)
1. wireless communication system, its executive communication between attached to wireless identification tag on the article and antenna, these article transmit on transmission path, antenna is with the direction radiation of electromagnetic wave towards transmission path, this system comprises and being used for from the reflection of electromagnetic wave of the antenna reflector element to the wireless identification tag on transmission path, wherein
Reflector element comprises a plurality of reflecting surfaces along the length direction of transmission path, wherein
Reflecting surface is arranged on the position that is used to improve the interference range that produces owing to the interference between reflection wave.
2. according to the wireless communication system of claim 1, the electromagnetic wavelength by considering to be used to communicate by letter wherein is arranged in reflecting surface on the position of Width of transmission path.
3. according to the wireless communication system of claim 2, wherein with of the length direction arrangement of a plurality of reflecting surfaces along transmission path.
4. according to the wireless communication system of claim 2, wherein with reflecting surface as of the length direction arrangement of single surface along transmission path.
5. according to the wireless communication system of claim 3, wherein with a plurality of reflecting surfaces to arrange from the different distance of the transmission path that provides betwixt.
6. according to the wireless communication system of claim 5, wherein, when having the individual reflecting surface of N (N is equal to or greater than 3 integer), N reflecting surface is arranged in the mobile mutually position of Width of transmission path with the electromagnetic spacing that is similar to 1/4 wavelength that is used to communicate by letter.
7. according to the wireless communication system of claim 3, wherein a plurality of reflecting surfaces are arranged with the different elevations angle.
8. according to the wireless communication system of claim 1, wherein reflecting surface reciprocally moves at least or at the Width of transmission path or the direction of inclination.
9. according to the wireless communication system of claim 1, wherein reflecting surface reciprocally rotates around transverse axis.
10. according to the wireless communication system of claim 1, wherein with the angular arrangement of reflecting surface with a direction that intersects with respect to length direction with transmission path.
11., wherein reflecting surface is arranged with the elevation angle with respect to vertical direction according to the wireless communication system of claim 1.
12., wherein reflecting surface is arranged with the elevation angle with respect to vertical direction in adjacent region according to the wireless communication system of claim 1.
13. according to the wireless communication system of claim 12, wherein reflecting surface is combined into the shape of taper, its direction towards article on transmission path is extended.
14. wireless communication system, its executive communication between attached to wireless identification tag on the article and antenna, these article transmit on transmission path, antenna is with the direction radiation of electromagnetic wave towards transmission path, this system comprises and being used for from the reflection of electromagnetic wave of the antenna reflection unit to the wireless identification tag on transmission path, wherein
Reflection unit comprises a plurality of reflecting surfaces along the length direction of transmission path, wherein
Reflecting surface is arranged on the position that is used to improve the interference range that produces owing to the interference between reflection wave.
15. a wireless communications method, its executive communication between attached to wireless identification tag on the article and antenna, these article transmit on transmission path, and antenna is with the direction radiation of electromagnetic wave towards transmission path, wherein:
From the electromagnetic wave of antenna by the direction reflection of the reflecting surface of reflector element towards the wireless identification tag on transmission path; With
Electromagnetic wave is being used to improve owing to reflect on the position of disturbing the interference range that produces between the reflection wave by the reflecting surface of reflector element.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2006160694 | 2006-06-09 | ||
| JP2006160694 | 2006-06-09 | ||
| JP2007130849 | 2007-05-16 |
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| CN101183431A true CN101183431A (en) | 2008-05-21 |
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| Application Number | Title | Priority Date | Filing Date |
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| CNA2007101701795A Pending CN101183431A (en) | 2006-06-09 | 2007-06-04 | Wireless communication system and wireless communication method |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102204009A (en) * | 2008-07-09 | 2011-09-28 | 康宁光缆系统有限公司 | Transponder systems and methods for radio-over-fiber (rof) wireless picocellular systems |
| CN101751583B (en) * | 2009-07-29 | 2012-03-21 | 中国科学院自动化研究所 | System and method for recognizing motor vehicle built-in electronic tag |
| CN107766761B (en) * | 2016-08-22 | 2021-01-12 | 东芝泰格有限公司 | Reading device |
| CN113807481A (en) * | 2020-06-16 | 2021-12-17 | 电装波动株式会社 | Interference suppression device and interference suppression system |
| CN114126988A (en) * | 2019-06-20 | 2022-03-01 | 村田机械株式会社 | Conveying vehicle |
| CN114275426A (en) * | 2021-11-08 | 2022-04-05 | 云南电网有限责任公司玉溪供电局 | Tool storehouse in-out detection device based on radio frequency identification technology |
-
2007
- 2007-06-04 CN CNA2007101701795A patent/CN101183431A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102204009A (en) * | 2008-07-09 | 2011-09-28 | 康宁光缆系统有限公司 | Transponder systems and methods for radio-over-fiber (rof) wireless picocellular systems |
| CN101751583B (en) * | 2009-07-29 | 2012-03-21 | 中国科学院自动化研究所 | System and method for recognizing motor vehicle built-in electronic tag |
| CN107766761B (en) * | 2016-08-22 | 2021-01-12 | 东芝泰格有限公司 | Reading device |
| CN114126988A (en) * | 2019-06-20 | 2022-03-01 | 村田机械株式会社 | Conveying vehicle |
| CN114126988B (en) * | 2019-06-20 | 2023-11-10 | 村田机械株式会社 | Conveying vehicle |
| CN113807481A (en) * | 2020-06-16 | 2021-12-17 | 电装波动株式会社 | Interference suppression device and interference suppression system |
| CN114275426A (en) * | 2021-11-08 | 2022-04-05 | 云南电网有限责任公司玉溪供电局 | Tool storehouse in-out detection device based on radio frequency identification technology |
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