JP2008206065A - Wireless authentication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wireless authentication system which judges on which of sides a transponder is present and from which side to the other a person passes by transmitting an interrogation signal from an interrogator installed at an entrance etc., of two spatial domains and making a transponder send back an acknowledge signal, passage being accurately judged and problems associated with construction such as routing of a wiring being made small even when an LF-band antenna which forms a detection area in an 8 (spindle) shape, but is low-cost and very convenient is used. <P>SOLUTION: Radiation surfaces A1a and A2a of two antennas A1 and A2 are arranged on a boundary surface (1) between the two spatial domains (3, 20) with an interval L in a direction of the boundary surface (1) while crossing each other at an angle θ in a spread or inverted spread shape, and then detection areas AR11 and AR12, and AR21 and AR22 are arranged in a nearly isosceles triangle shape to overlap (AR11, AR21) at the vertical angle part and not overlap (AR12, AR22) at base angle parts. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention is used in an RFID (RADIO FREQUENCY IDENTIFICATION) system, and a responder (IC tag) is activated in a non-contact manner from an interrogator, receives information, and returns its identification information. The present invention relates to a wireless authentication system that is preferably realized as a non-contact IC tag system or an IC card system.

  A typical prior art of the wireless authentication system as described above is disclosed in Patent Document 1. FIG. 4 is a diagram for explaining the wireless authentication system according to the prior art. In this wireless authentication system, it is possible to detect the passage of the user 2 in a traffic part (door 9) between the room 3 which is one space area separated by the wall 1 which is a boundary and the outside of the room 3 which is the other space area. Thus, entrance / exit management of the room 3 that can manage which user exists in the room 3 and at what time the user enters and exits is realized. In addition, when used for article management, it is possible to manage which products are received and received at what time, and how many products are present in the warehouse.

  This wireless authentication system includes an infrared transmitter 4 as an activation device and a management device 5 constituting the authentication device, which includes an IC tag and a responder 6 carried by the user 2. The infrared transmitter 4 is arranged inside and outside the room 3 in the vicinity of the traffic part (door 9), and irradiates infrared rays with different identification information (ID) superimposed on a narrow detection area 7. The responder 6 that has received the infrared rays wirelessly returns a response signal including its own identification information (ID) to the identification information (ID) of the infrared transmitter 4. The response signal is received by the antenna 8, and the management device 5 unlocks the door 9 if the identification information (ID) is registered in advance.

  However, the above-described prior art uses infrared light to activate the responder 6. Infrared rays are convenient for forming the narrow detection area 7 as described above. However, for example, when the infrared transmitter 4 is installed on the ceiling and the name tag type responder 6 faces downward, it does not react. In some cases, it is inconvenient. Therefore, in order to solve such a problem, a conventional technique using the LF band for activation is proposed in Patent Document 2.

  FIG. 5 is a diagram for explaining a wireless authentication system according to the prior art of Patent Document 2. In FIG. In FIG. 5, the configuration is similar to that of FIG. 1 described above, and corresponding portions are denoted by the same reference numerals and description thereof is omitted. This wireless authentication system includes an interrogator 14 that constitutes the activation device and the authentication device, and a management device 10 that manages them, and a responder 16 that includes the IC tag.

  The interrogator 14 generates an interrogation signal including unique identification information (ID) set in advance in the interrogator 14 and transmits it to the responder 16 by the first wireless communication method (LF). As a result, a detection area 17 is formed around the responder 16, and the responder 16 possessed by the user 2 or the like that enters the detection area 17 receives the question signal and receives the ID of the interrogator 14. In addition, a response signal including unique identification information (ID) preset in itself is generated and returned to the interrogator 14 by the second wireless communication method (UHF). If the returned response signal has identification information (ID) registered in advance, the interrogator 14 uses the second wireless communication method (UHF) to identify the identification information (ID of the responder 16 that has been authenticated. ) As an ACK signal. When receiving the ACK signal, the responder 16 ends the transmission of the response signal.

  Further, when the authentication is completed, the interrogator 14 unlocks the door 9. Further, as described above, the management device 10 manages which user is present in the room 3 and at what time it enters and exits from the authentication result, and what product arrives and arrives at the warehouse. It manages how many products are in the market.

  In this way, the responder 16 is activated with an electromotive force in the LF band (long wave band: 30 to 300 kHz) and a response signal is returned in the UHF band (ultra high frequency band: 300 MHz to 3 GHz), so that it is cheap and easy to use (direction) The detection area 17 can be accurately defined within a relatively narrow range of 1.5 to 2 m.

  However, although the radio wave type using the LF band is cheap and easy to use as described above, the antenna 14a of the first wireless communication method (LF) in the interrogator 14 is composed of a small coiled reader antenna. As shown in FIG. 6, when the radio wave of the LF band is transmitted, a substantially symmetrical 8-shaped (spindle) LF band reaching area is formed as the detection area 17 before and after the radiation surface of the antenna 14a. End up. For this reason, when the two antennas 14a are arranged on the inner side and the outer side (the hallway side) of the room 3 with the traffic part (door 9) sandwiched between them as shown in FIG. The LF band arrival area (detection area 17) overlaps at the door 9 which is the boundary, and response signals are generated at the same time, so that the management device 10 cannot determine from which side the user has passed. There's a problem. In particular, the LF band passes through a structure (wall 1 or door 9).

  Therefore, as shown in FIG. 8, when the two antennas 14 a are installed separately from the wall surface 1 so that the LF band arrival area (detection area 17) does not overlap, as shown by reference numeral 19, There is a problem that the question signal does not reach the user who has come and the electric lock of the door 9 does not react. In addition, the wiring laid on the wall surface 1 or the like must be routed to the antenna 14a away from the wall surface 1, which causes problems in construction and aesthetics.

On the other hand, in Patent Document 3, in order to solve the problem of Patent Document 2 as described above, there is one loop coil that forms a detection area in the shape of a figure 8 and is embedded in a wall. Detection areas are set equally on both sides of the part (door), and the passing direction is determined by the order in which the pressure sensitive mats installed on the floors on both sides of the traffic part (door) are stepped on.
JP 2006-72706 A Japanese Patent Laid-Open No. 2003-21679 JP 2003-213998 A

  However, in the prior art of Patent Document 3, a pressure-sensitive mat must be installed on the floor surface, which is a large scale, and there are great problems in construction and aesthetics due to the routing of the wiring. For this reason, only new buildings can be applied.

  The object of the present invention is to provide a transponder on either side of two spatial regions, even if an antenna is used in which detection areas are formed almost symmetrically before and after the radiation surface corresponding to low-cost and convenient low-frequency signals. By providing a wireless authentication system that can accurately determine from which side it has passed to and from which part of the traffic section, and can reduce construction problems such as wiring routing is there.

  The wireless authentication system of the present invention transmits an interrogation signal from two interrogators installed near the traffic part of two spatial areas, and the responder responds to the interrogation signal with a response signal including its own identification information. In the wireless authentication system that determines which side of the two spatial areas the transponder is sent to, and from which side through the traffic part, it radiates as an antenna in each interrogator. An antenna in which detection areas are formed approximately symmetrically before and after the plane, the radiation planes of the two antennas intersect with the opposite planes of the boundary planes of the two spatial regions, and in the direction of the boundary plane By arranging the gaps at predetermined intervals, the substantially symmetrical detection areas are set so that most of them overlap in one space area and most do not overlap in the other space area. From the reception result of the response signal in the response unit is either present on either side of the two spatial regions, also characterized in that it comprises a determining host device whether it has passed into either from either the traffic portion.

  Further, the wireless authentication system of the present invention transmits a question signal from two interrogators installed in the vicinity of the traffic part of two spatial regions, and the response unit includes its own identification information in response to the question signal. In the wireless authentication system for determining which side of the two spatial regions the transponder is present by returning a signal, and from which side of the traffic part, the antenna in each interrogator Using a coiled reader antenna in which a detection area is formed in an 8-shaped shape that is substantially symmetric in plan view before and after the radiation surface, and the radiation surface of the two antennas is defined with respect to the boundary surface of the two spatial regions The detection area is arranged in a substantially isosceles triangle shape by crossing a letter C or an inverted letter C and arranging the two antennas at a predetermined interval in the boundary surface direction, It is set so that it overlaps with each other at the corners and does not overlap with each other at the two bottom corners, and from the reception result of the response signal in each interrogator, on which side of the two spatial regions the responders are present, And a host device that determines from which direction the traffic part has passed.

  According to the above configuration, an interrogator is realized as a wireless tag authentication system or the like, and the interrogator is transmitted from the two interrogators installed near the traffic part such as the entrance / exit of the two space areas, and the responder responds to the interrogator signal. Then, a response signal including its own identification information is returned to determine which side of the two space areas the responder exists, and from which side through which the traffic part has passed. In the system, the interrogation signal from each interrogator has a low frequency (long wavelength) as in the LF band, and radiates a signal that can narrow the detection area, such as a light beam or a high frequency signal, as an antenna in each interrogator. An antenna that is composed of a small coiled reader antenna, etc., and whose detection area is formed approximately symmetrically (eight-shaped (spindle) shape in plan view) before and after the radiation surface If you are, it would overlap the detection area, the determination and the passing direction judgment of the presence area becomes difficult. Therefore, in the present invention, the antenna is arranged so as to overlap the detection area in one spatial region of the traffic part, so that it does not overlap in the other spatial region, and the reception result of the response signal in each interrogator is From the logic, the host device determines on which side of the two spatial regions the transponder is located and from which side it has passed through the traffic part.

  Specifically, the radiation surfaces of the two antennas are opposite in phase with respect to the boundary surface of the two spatial regions, that is, crossed in a letter C or a reverse letter C, and in advance in the direction of the boundary surface. The substantially symmetric detection area is mostly arranged in one spatial region by arranging a predetermined interval L and adjusting the intersection angle θ corresponding to the distance L and the detection area R formed by the antenna. And the detection areas are set to be approximately isosceles triangles, preferably equilateral triangles, and overlap each other at the apex portion, and mutually overlap at the two base corner portions. It will be set not to overlap.

  Therefore, from the logic of the reception results of the response signals respectively received in the detection area of the apex angle portion formed in one spatial region and the detection area of the two bottom angle portions formed in the other spatial region The host device, for example, remains in the detection area of the apex portion, i.e. one spatial region, or remains in the detection area of the two base corner portions, i.e. the other spatial region, or 2 Was it moved between the detection areas of the two corners, or passed through the traffic area between the detection areas of the apex corners, that is, one spatial area and the detection area of the bottom corners, that is, the other spatial area? Can be determined.

  In this way, even if an antenna that forms a detection area approximately symmetrically before and after the radiation surface corresponding to a low-frequency and convenient low-frequency question signal is used, the transponder exists on either side of the two spatial regions In addition, it is possible to accurately determine from which side the traffic part has been passed. In addition, the antenna can be installed near the traffic part of the two space areas such as the door and the wall surface, and construction problems such as wiring can be reduced.

  Furthermore, in the wireless authentication system of the present invention, each interrogator uses at least one of time division, frequency division, code division, and different modulation schemes to prevent interference of the interrogation signal in the responder. It is characterized by that.

  According to the above configuration, the interrogator identification information is included in the interrogator signal and the source interrogator can be specified, but in particular the apex portion where the two detection areas overlap If the interrogation signal interferes in the detection area, the responder stops responding, so time division multiple access (TDMA), frequency division multiple access (FDMA), code division multiple access (CDMA), or different from each other Interference of the interrogation signal is prevented at a portion where the detection areas overlap by using a modulation method or the like.

  Therefore, the response of the responder can be promptly performed, and many responders can be handled.

  In the wireless authentication system of the present invention, the interrogator is connected to the host device, and the control circuit for generating the interrogation signal and the interrogation signal superimposed on the signal component of the induced magnetic field An LF transmission circuit and an LF antenna that transmit to the responder in a wireless communication scheme; an RF antenna and an RF reception circuit that receives the response signal from the responder and applies the response signal to the control circuit; and The responder includes an LF antenna and an LF receiving circuit for receiving an interrogation signal from the interrogator, a built-in battery, and a response signal including the unique identification information set in advance in response to the received interrogation signal A control circuit for generating a response, and an RF transmission circuit and an RF antenna for returning the response signal to the interrogator in the second wireless communication system using the built-in battery as a power source The features.

  According to the above configuration, the interrogator activates the responder with the electromotive force of the LF band (long wave band: 30 to 300 kHz), and the control circuit on the responder side uses the built-in battery as the power source for the RF transmission circuit. A response signal in the UHF band (ultra-high frequency band: 300 MHz to 3 GHz) is returned.

  Therefore, even if the inquiry signal is transmitted through the inexpensive and easy-to-use LF band, the response signal can be returned stably by using the UHF band, and the power consumption of the RF transmission circuit in the UHF band is 10 to 10. Even if it is as large as 20 mA, the LF band LF receiver circuit operates with a weak power of several μA. Therefore, by not using the RF transmitter circuit in the standby state, the power consumption of the built-in battery is suppressed, and the long life of the responder Can be achieved.

  As described above, the wireless authentication system of the present invention is realized as a wireless tag authentication system or the like, and transmits a question signal from two interrogators installed in the vicinity of a traffic part such as an entrance / exit of two space areas, and responder In response to the interrogation signal, a response signal including its own identification information is returned, so that the responder is located on which side of the two spatial regions, and from which direction the traffic part has passed. In the wireless authentication system for determining whether the interrogator has a low frequency (long wavelength) as in the LF band, the interrogator detects the antenna in each interrogator as a light beam or a high frequency signal. It does not radiate a signal that narrows down the area, but consists of a small coiled reader antenna, etc., and the detection area is formed approximately symmetrically (in the shape of a figure 8 (spindle) in plan view) before and after the radiation surface. In the case where an antenna is used, the antenna is arranged so as to overlap the detection area in one spatial region of the traffic part, so that it does not overlap in the other spatial region. From the logic of the reception result, the higher-level device determines which side of the two spatial regions the responder is located and from which side the traffic part has passed.

  Therefore, even if an antenna whose detection area is formed approximately symmetrically before and after the radiation surface corresponding to the low-frequency and convenient low-frequency question signal is used, the transponder is located on either side of the two spatial regions. It is possible to accurately determine whether it exists and from which side it has passed the traffic part. In addition, the antenna can be installed near the traffic part of the two space areas such as the door and the wall surface, and construction problems such as wiring can be reduced.

  Furthermore, as described above, the wireless authentication system of the present invention can identify the interrogator as the transmission source because the interrogator identification information is included in the interrogator signal between the interrogators. If the interrogation signal interferes in the detection area of the apex portion where the two detection areas overlap, the responder will not respond, so time division multiple access (TDMA), frequency division multiple access (FDMA), code division multiple Interference of the interrogation signal is prevented in the portion where the detection areas overlap by using connection (CDMA) or using different modulation schemes.

  Therefore, the response of the responder can be promptly performed, and many responders can be handled.

  In the wireless authentication system of the present invention, as described above, the interrogator is connected to the host device, the control circuit for generating the interrogation signal, and the interrogation signal superimposed on the signal component of the induced magnetic field. And an LF transmission circuit and an LF antenna for transmitting to the responder in a first wireless communication system, and an RF antenna and an RF reception circuit for receiving the response signal from the responder and supplying the response signal to the control circuit. And the responder is configured to respond to the interrogation signal received by an LF antenna and an LF receiving circuit that receive an interrogation signal from the interrogator, and to receive the interrogation signal. A control circuit for generating a response signal including information, and an RF transmission circuit and an RF antenna for returning the response signal to the interrogator by the second wireless communication system using the built-in battery as a power source It is configured with a.

  Therefore, even if the inquiry signal is transmitted through the LF band which is cheap and easy to use, the response signal can be returned stably by using the UHF band, and the power consumption of the RF transmission circuit in the UHF band is 10 Even if it is as large as -20 mA, the LF band LF receiver circuit operates with a weak power of several μA. Therefore, by not using the RF transmitter circuit in the standby state, the power consumption of the built-in battery is suppressed, and the length of the responder Life can be extended.

  FIG. 1 is a block diagram showing an electrical configuration of a wireless authentication system according to an embodiment of the present invention. This wireless authentication system controls two interrogators TX1 and TX2, one or a plurality of responders RX (one in the example of FIG. 1) RX, and the interrogators TX1 and TX2. It comprises a host device B that performs entry / exit management and article management. Each of the interrogators TX1 and TX2 includes small coiled reader antennas A1 and A2 that are adapted to the LF band (long wave band: 30 to 300 kHz), which is the first wireless communication system, for transmitting a question signal to be described later. ing.

  In each interrogator TX1, TX2, the control circuit 31 generates a question signal including unique identification information (ID) set in advance in the interrogator TX1, TX2, and superimposes it on the signal component of the induced magnetic field in the LF transmission circuit 32, Amplified and transmitted from the antennas A1 and A2 toward the responder RX by the first wireless communication method (LF). As a result, detection areas AR11, AR12; AR21, AR22, which will be described later, are formed around the responder RX, and in the responder RX possessed by the user or the like who has entered the detection areas AR11, AR12; AR21, AR22, After the interrogation signal is received by the three-axis LF antenna 33 of X, Y, and Z, the LF reception circuit 34 activates the control circuit 35. The control circuit 35 is operated by the power of the built-in battery 36, and A response signal including unique identification information (ID) set in advance in the identification information of the interrogators TX1 and TX2 is generated, and the second wireless communication method is transmitted from the RF transmission / reception circuit 37 via the RF antenna 38. Is returned to the interrogators TX1 and TX2 in the UHF band (ultra high frequency band: 300 MHz to 3 GHz).

  The response signal is received by the RF transmission / reception circuit 40 from the RF antenna 39 of the interrogators TX1 and TX2, and is input to the control circuit 31 to identify the responder RX that has responded. If the identified transponder RX has identification information registered in advance, the control circuit 31 transmits the RF transceiver circuit 40 to the second wireless communication system (UHF) via the RF antenna 39. The identification information of the responder RX that has been authenticated is transmitted as an ACK signal. When the ACK signal is received from the RF antenna 38 by the RF transmission / reception circuit 37, the control circuit 35 ends the transmission of the response signal.

  When the authentication is completed, the control circuit 31 indicates the completion of authentication with the display unit 41 and the buzzer 42 and simultaneously unlocks the door. Further, as described above, the management device B manages which user is present in the room and when it enters and exits from the authentication result of the control circuit 31, and which product is received and received when. And how many products exist in the warehouse.

  In this way, the responder RX is activated by the electromotive force in the LF band, and the control circuit 35 causes the RF transmitter / receiver circuit 37 to return a response signal in the UHF band with the built-in battery 36 as a power source. The detection areas AR11, AR12; AR21, AR22 can be accurately defined in a relatively narrow range of 1.5 to 2 m. Furthermore, the power consumption of the RF transmission / reception circuit 37 in the UHF band is as large as 10 to 20 mA, whereas the LF reception circuit 34 in the LF band is activated with a weak power of several μA. By not using 37, the power consumption of the built-in battery 36 is suppressed, and the life of the responder RX is extended.

  FIG. 2 is a schematic plan view for explaining in detail the installation method of the antennas A1 and A2 according to the present invention. In this example, as in the wireless authentication system of FIGS. 4 and 5 described above, the room 3 that is the first space area and the room 3 that is the second space area partitioned by the wall 1 that is the boundary surface. The antennas A1 and A2 of the two interrogators TX1 and TX2 are installed in the vicinity of the door 9, which is a traffic part to the outside corridor 20. It should be noted that the present invention uses a coiled reader antenna in which the detection areas AR11, AR12; AR21, AR22 of the antennas A1, A2 are formed in an 8-shaped (spindle) shape as shown in FIG. In this case, the radiating surfaces A1a and A2a of the two antennas A1 and A2 are made to have a C-shape or an inverted C-shape (in the example of FIG. 2) with respect to the boundary surface (1) of the two space regions (3, 20). And the two antennas A1 and A2 are arranged with a predetermined interval L in the direction of the boundary surface (1). Thereby, the detection areas AR11, AR12; AR21, AR22 are arranged in a substantially isosceles triangle shape, and most of the apex angle portions on the side of the room 3 which is one space region overlap each other (AR11, AR21), The two bottom corners on the side of the hallway 20 which is the other space area are set so that most do not overlap each other (AR12, AR22).

  The responder RX returns a response signal in response to the interrogation signals from the antennas A1 and A2, and the case where the interrogators TX1 and TX2 are authenticated is set to “1”, and the response signal is not detected and authentication is performed. If not, the higher-level device B receives the authentication result from the control circuit 31 and determines the entrance / exit from the logic of the authentication result as shown in Table 1 and exists. Save history.

  That is, as shown in mode 1, when only one of the interrogators TX1 and TX2 is detected, the user exits from the overlapping detection areas AR11 and AR21, and mutually Since it has entered either the detection area AR12 or AR22 that does not overlap, it can be determined that the room 3 has left the hallway 20 side. On the other hand, as shown in mode 2, when both of the interrogators TX1 and TX2 are detected, the user exits from either of the detection areas AR12 or AR22 that do not overlap each other. Thus, since the detection areas AR11 and AR21 that overlap each other are entered, it can be determined that the room 3 is entered from the corridor 20 side.

  In addition, as shown in mode 3, when one of the interrogators TX1 or TX2 is detected and the other is detected, the user has moved between the detection areas AR12 and AR22 that do not overlap each other. Therefore, it can be determined that the corridor 20 has been passed. Furthermore, as shown in mode 4, when the interrogators TX1 and TX2 are not detected together, both are detected, and when both are not detected again, the user overlaps the detection area AR11. , AR21, it can be determined that the user has moved in the room 3. In modes 3 and 4, the interrogator TX1 or TX2 reacts and unlocks the door 9, although it does not actually pass through the traffic part (door 9).

  By configuring in this way, the host device B allows the responder RX to remain in, for example, the detection areas AR11 and AR21 of the apex portion, that is, one of the spatial regions (3), or The detection areas AR12, AR22, that is, staying in the other spatial region (20) or moved between the detection areas AR12, AR22 of the two bottom corners, or the detection areas AR11, AR21 of the apex corner, ie, one It is possible to determine whether or not the traffic part (9) between the space area (3) and the detection areas AR12 and AR22 of the bottom corner portion, that is, the other space area (20), has passed.

  Thus, a small coiled reader antenna is used in which the detection areas AR11, AR12; AR21, AR22 are formed approximately symmetrically before and after the radiation surfaces A1a, A2a corresponding to the low-cost and convenient LF band interrogation signals. However, it is possible to accurately determine on which side of the two spatial regions (3, 20) the transponder RX has passed and from which side the traffic part (9) has passed. Further, the antennas A1 and A2 can be installed near the traffic part (9) of the two space areas (3, 20) such as the top of the door 9 and the wall 1 surface, and the wiring is routed. The problem can be reduced.

  Further, when the antennas A1 and A2 are arranged close to each other and the interrogators TX1 and TX2 are housed in an integral housing, it is not only suitable for downsizing but also easy to construct, and adjustment of the angle θ described later Is also unnecessary.

  Here, as shown in FIG. 2, in order to make the detection areas AR11 and AR21 (the LF band arrival area) coincide with each other, the antennas A1 and A21 are placed at the same radius R from the centers P of the detection areas AR11 and AR21. A2 may be installed, and the angle θ of the antennas A1 and A2 may be adjusted so that the radiation surfaces A1a and A2a are tangent to the circles of the detection areas AR11 and AR21 as shown in FIG.

  In addition, the interrogation signals from the interrogators TX1 and TX2 include the identification information (ID) of the interrogators TX1 and TX2, and can identify the source interrogator. , AR21 will interfere with the interrogation signal in the detection area of the apex portion where AR21 overlaps, so that the responder RX will not respond, so the LF transmitter circuit 32 is provided with time division multiple access (TDMA), frequency division multiple access ( Interference of the interrogation signal is prevented at a portion where the detection areas AR11 and AR21 overlap by using FDMA), code division multiple access (CDMA), or using different modulation schemes.

  FIG. 3 shows the operation of transmitting the interrogation signals from the antennas A1 and A2 when the time division multiple access (TDMA) is adopted, and the reception operation of the responders RX existing in the detection areas AR11 and AR12; AR21 and AR22. Indicates. By preventing the interference of the interrogation signal in this way, the response of the responder RX can be promptly performed, the time required for the response of one responder can be shortened, and many responders are supported. be able to. Furthermore, the response signal in the UHF band can also be used for each detection area by using the time division multiple access (TDMA), frequency division multiple access (FDMA), code division multiple access (CDMA), or different modulation schemes. It is possible to prevent interference of response signals when there are a plurality of responders in AR11, AR12; AR21, AR22.

  In addition, as shown in the mode 3 or 4, it is not necessary to react (unlock operation) to a user who simply passes in front of the door 9, but it goes in and out beyond the traffic part (9). Since the user must react (unlock operation), when performing time division multiple access (TDMA) in this way, each interrogator TX1 is alternately and continuously performed as shown in FIG. The transmission period of the question signal from TX2 needs to be set sufficiently shorter than the time during which the user who passes through the traffic section (9) stays in each of the detection areas AR11, AR12; AR21, AR22. Otherwise, only the question signal of the detection area AR11, AR21 and detection area AR12, AR22, which was received first for unlocking the door 9, was received, and the destination that passed through the traffic part (9) This is because there is a possibility that a question signal will not be received, and an error will occur in the occupancy and inventory check.

1 is a block diagram showing an electrical configuration of a wireless authentication system according to an embodiment of the present invention. It is a typical top view for explaining in detail the installation method of the antenna by the present invention. It is a figure for demonstrating the transmission timing of the inquiry signal by one Embodiment of this invention. 1 is a diagram for explaining a typical conventional wireless authentication system. It is a figure for demonstrating the radio | wireless authentication system by another prior art. It is a figure which shows the radiation characteristic of a small coil-shaped reader antenna of LF band. It is a figure for demonstrating the problem by the radiation characteristic shown in FIG. It is another figure for demonstrating the problem by the radiation | emission characteristic shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wall 2 User 3 Room 9 Door 20 Corridor 31, 35 Control circuit 32 LF transmission circuit 33 LF antenna 34 LF reception circuit 36 Built-in battery 37, 40 RF transmission / reception circuit 38, 39 RF antenna 41 Display part 42 Buzzer A1, A2 Coil shape Reader antenna A1a, A2a Radiation surface AR11, AR12; AR21, AR22 Detection area B Host device RX Transponder TX1, TX2 Interrogator

Claims (4)

The interrogator transmits an interrogation signal from two interrogators installed near the traffic part of the two spatial regions, and the transponder returns a response signal including its own identification information in response to the interrogation signal. In the wireless authentication system for determining which side of the two spatial regions is present and from which direction the traffic part has been passed,
Using an antenna in which a detection area is formed approximately symmetrically before and after the radiation surface as an antenna in each interrogator,
The radiation areas of the two antennas intersect with the boundary surfaces of the two spatial regions in opposite phases to each other, and are arranged at a predetermined interval in the boundary surface direction, thereby providing the substantially symmetric detection area. Is set so that the majority overlaps in one spatial region and the majority does not overlap in the other spatial region,
And a host device for determining which side of the two spatial regions the response device is received from, and from which side the traffic unit has been passed, based on the reception result of the response signal in each interrogator. A featured wireless authentication system. The interrogator transmits an interrogation signal from two interrogators installed near the traffic part of the two spatial regions, and the transponder returns a response signal including its own identification information in response to the interrogation signal. In the wireless authentication system for determining which side of the two spatial regions is present and from which direction the traffic part has been passed,
As the antenna in each interrogator, a coiled reader antenna in which a detection area is formed in an 8-shaped shape that is substantially symmetrical in plan view before and after the radiation surface,
The radiation surface of the two antennas intersects the C-shape or reverse C-shape with respect to the boundary surface of the two spatial regions, and the two antennas are arranged at a predetermined interval in the boundary surface direction. Thus, the detection areas are arranged in a substantially isosceles triangle shape, are set so as to overlap each other at the apex angle portion, and not overlap each other at the two base angle portions,
And a host device for determining which side of the two spatial regions the response device is received from, and from which side the traffic unit has been passed, based on the reception result of the response signal in each interrogator. A featured wireless authentication system.   3. The interrogator prevents interference of the interrogation signal in the responder by using at least one of time division, frequency division, code division, and different modulation method. Wireless authentication system. The interrogator is
A control circuit connected to the host device and generating the interrogation signal;
An LF transmission circuit and an LF antenna for superimposing the interrogation signal on a signal component of an induced magnetic field and transmitting the interrogation signal to the responder in a first wireless communication method;
An RF antenna and an RF receiving circuit configured to receive the response signal from the responder and apply the response signal to the control circuit;
The responder is
An LF antenna and an LF receiving circuit for receiving an interrogation signal from the interrogator;
Built-in battery,
A control circuit for responding to the received interrogation signal and generating a response signal including the preset unique identification information;
4. An RF transmission circuit and an RF antenna that return the response signal to the interrogator by the second wireless communication method using the built-in battery as a power source. 5. The wireless authentication system described in 1.

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