JP2006261891A - Radio tag communication device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio tag communication device which is capable of controlling and directing its communication directivity in an optimal direction independently of its attitude. <P>SOLUTION: The radio tag communication device 12 is equipped with a gravity sensor 62 and a geomagnetic sensor 64 which detect the attitudes of array antennas 36 and 40 on the basis of the prescribed coordinates, a transmission PAA wait control unit 34 and a receiving PAA wait control unit 54 which control the directivity of communication with the radio tag 14 corresponding to the attitudes detected by the gravity sensor 62 and the geomagnetic sensor 64, so that a main lobe can be kept in a prescribed direction even if the radio tag communication device 12 is varied in attitude. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a wireless tag communication device that performs communication with a wireless tag capable of wirelessly writing and reading information, and more particularly to improvement of communication directivity control.

  2. Description of the Related Art An RFID (Radio Frequency Identification) system is known in which information is read out in a non-contact manner by a predetermined wireless tag communication device (interrogator) from a small wireless tag (responder) that stores predetermined information. This RFID system is capable of reading information stored in a wireless tag by communication with the wireless tag communication device even when the wireless tag is dirty or disposed at an invisible position. Therefore, practical use is expected in various fields such as merchandise management and inspection processes.

  As one aspect of the above-described RFID tag communication apparatus, a portable RFID tag communication apparatus (handy scanner) provided to be movable with respect to a predetermined position such as a room that is a detection range has been proposed. For example, this is the portable terminal described in Patent Document 1. According to this technology, it is said that a lightweight and small-sized RFID tag communication device that can be easily carried and used by a user can be provided.

JP 2001-307032 A

  However, in order to extend the communicable distance of the portable wireless tag communication device as in the conventional technique as much as possible, it is conceivable to control the main lobe direction using an antenna that can change the communication directivity. However, when the user tilts the portable RFID tag communication device, the main lobe direction also tilts, and the communication state relatively changes depending on the posture of the device itself, so that the optimum communication state is established. There was an evil that it was difficult. For this reason, there has been a demand for the development of a wireless tag communication device that can control the communication directivity in an optimum direction regardless of the posture of the device itself.

  The present invention has been made in the background of the above circumstances, and an object of the present invention is to provide a wireless tag communication apparatus capable of controlling communication directivity in an optimum direction regardless of the attitude of the apparatus itself. There is.

  In order to achieve such an object, the gist of the present invention is that an antenna is integrally provided, a transmission signal is transmitted to a wireless tag, and a response is returned from the wireless tag according to the transmission signal. A wireless tag communication device that receives a reply signal and communicates information with the wireless tag, and is provided in the wireless tag communication device, and detects the posture of the antenna based on predetermined coordinates And a directivity control unit that controls the directivity direction of the communication according to the posture detected by the posture sensor.

  As described above, according to the present invention, the wireless tag communication device is provided with the posture sensor that detects the posture of the antenna with reference to predetermined coordinates, and the communication of the communication according to the posture detected by the posture sensor. Since the directivity control unit that controls the directivity direction is provided, the main lobe direction can be maintained in a predetermined direction even when the attitude of the RFID tag communication apparatus varies. That is, it is possible to provide a wireless tag communication device that can control the communication directivity in an optimum direction regardless of the posture of the device itself.

  Here, preferably, the RFID tag communication device is a portable device provided to be movable with respect to a predetermined position. In this way, the communication directivity can be controlled in the optimum direction regardless of the attitude of the portable radio tag communication apparatus whose attitude is likely to fluctuate due to handling by the user.

  Preferably, the posture sensor is a tilt sensor that detects the tilt of the antenna with reference to the direction of gravity. In this way, the communication directivity can be controlled in the optimum direction regardless of the attitude of the apparatus itself with respect to the direction of gravity.

  Preferably, the attitude sensor is an azimuth sensor that detects the azimuth of the antenna with reference to the geomagnetic direction. In this way, the communication directivity can be controlled in the optimum direction regardless of the attitude of the device itself with respect to the geomagnetic direction.

  Preferably, the directivity control unit performs control so that the directivity direction of the communication is a predetermined one direction. In this way, communication directivity can be controlled in a predetermined direction regardless of the attitude of the apparatus itself.

  Preferably, the directivity control unit performs control so that the communication directivity direction is any one of a plurality of predetermined directions. In this way, when there are a plurality of wireless tags to be communicated, the communication directivity can be controlled in the direction in which the communication sensitivity with the wireless tags is the highest regardless of the attitude of the device itself. .

  In addition, preferably, it has a switching function for switching operation of the directivity control unit. In this way, when communication directivity control according to the attitude variation of the device itself is unnecessary, the control can be easily stopped.

  Preferably, the antenna has a plurality of antenna elements shared for transmission of the transmission signal and reception of the reception signal. In this way, communication directivity can be suitably controlled with an antenna having a simple configuration.

  Preferably, the antenna has at least three antenna elements involved in directivity with respect to a predetermined direction. In this way, the communication directivity can be controlled in a practical manner.

  Preferably, the antenna has five antenna elements sharing one antenna element with respect to the gravity direction and the geomagnetic direction, and controls the directivity direction of the communication based on the gravity direction and the geomagnetic direction. Is. In this way, it is possible to control the communication directivity with respect to the direction of gravity and the direction of geomagnetism in a practical manner.

  Preferably, the information processing apparatus includes a display unit that displays information and images related to the communication, and a grip unit for gripping when the mobile phone is carried, and the gripping unit is provided with a switching device for the switching function. It is a portable device. If it does in this way, the portable radio | wireless tag communication apparatus of a practical aspect can be provided.

  Preferably, the wireless tag communication device has a function of writing predetermined information to the wireless tag, and the switching function is an operation of the directivity control unit when writing information to the wireless tag. Is effective. In this way, when writing information to the wireless tag, which requires the control of the communication directivity because a large power supply is required, the communication directivity can be controlled in an optimum direction.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram for explaining a radio tag communication system 10 in which the present invention is preferably used. The RFID tag communication system 10 includes an RFID tag communication device 12 according to an embodiment of the present invention, and a single or plural (single in FIG. 1) RFID tags 14 that are communication targets of the RFID tag communication device 12. It is a so-called RFID (Radio Frequency Identification) system, and the RFID tag communication device 12 functions as an interrogator of the RFID system, and the RFID tag 14 functions as a responder. That is, when the interrogation wave F _c (transmission signal) is transmitted from the radio tag communication apparatus 12 toward the radio tag 14, a predetermined information signal (data) is received in the radio tag 14 that has received the interrogation wave F _c. As a result, the interrogation wave F _c is modulated and sent back to the RFID tag communication apparatus 12 as a response wave F _r (reply signal), so that information is transmitted between the RFID tag communication apparatus 12 and the RFID tag 14. Communication takes place.

  FIG. 2 is a perspective view illustrating an appearance of the wireless tag communication device 12. As shown in FIG. 2, the wireless tag communication device 12 includes a flat display unit (first flat plate unit) 16 that displays an image (video) related to communication with the wireless tag 14, and a grip when being carried. A flat plate-shaped gripping portion (second flat plate portion) 18 and an operation portion 20 composed of a plurality of operation buttons (switches) provided on the gripping portion 18. The shaft portion 22 is connected as a shaft and can be folded like a hinge, and is movable with respect to a predetermined position (for example, a room in which the wireless tag 14 to be communicated is disposed). This is a portable device (handy scanner) provided. Here, as a part of the operation unit 20, a switching button 20s for switching execution / non-execution of directivity control described later is provided. Further, the RFID tag communication device 12 includes a plurality of vertical antenna elements 38a, 38b, 38c constituting a vertical array antenna 36 and a plurality of horizontal directions constituting a horizontal array antenna 40 as will be described later. Antenna elements 42a, 42b, and 42c (the horizontal antenna element 42b is common to the vertical antenna element 38b). Both the vertical antenna element 38 and the horizontal antenna element 42 are provided. The display unit 16 is provided integrally (incorporated), and is configured to follow the display unit 16 and change its attitude with respect to predetermined reference coordinates.

  FIG. 3 is a diagram illustrating the configuration of the wireless tag communication device 12. As shown in FIG. 3, the wireless tag communication device 12 includes a transmission bit string generation unit 24 that generates a command bit string corresponding to a transmission signal to the wireless tag 14, and a digital signal output from the transmission bit string generation unit 24. An FSK encoding unit 26 that encodes a signal using the FSK method, an AM modulation unit 28 that modulates the signal encoded by the FSK encoding unit 26 using the AM method, and supplies (stores) the signal to the transmission signal memory unit 30; A transmission weight multiplication unit 32 that is a transmission PAA (Phased Array Antenna) processing unit that reads a transmission signal stored in the transmission signal memory unit 30 at any time and multiplies a predetermined transmission weight (transmission PAA weight), and a transmission weight thereof. A transmission PAA weight control unit 34 that controls transmission weights multiplied by the multiplication unit 32 is provided.

  In addition, a plurality of (three in FIG. 3) vertical antennas are used to transmit a transmission signal toward the wireless tag 14 and receive a reply signal returned from the wireless tag 14 in response to the transmission signal. A vertical array antenna 36 having elements 38a, 38b, 38c (hereinafter simply referred to as a vertical antenna element 38 unless otherwise specified), and a plurality (three in FIG. 3) of horizontal antennas. A horizontal array antenna 40 having elements 42a, 42b, 42c (hereinafter simply referred to as a horizontal antenna element 42 unless otherwise specified), and a local transmission signal output unit 44 that outputs a predetermined local transmission signal. And up-converting the transmission signal output from the transmission weight multiplication unit 32 in accordance with the local transmission signal output from the local transmission signal output unit 44 Then, the plurality of vertical antenna elements 38 and the horizontal antenna elements 42 are supplied to the plurality of vertical antenna elements 38 and the horizontal antenna elements 42, respectively, and the plurality of vertical antenna elements 38 are output according to the local transmission signal output from the local transmission signal output unit 44. , A plurality of (five in FIG. 3) high-frequency transmitting / receiving units 46a, 46b, 46c, 46d, which respectively down-convert received signals received by the horizontal antenna element 42 and supply (store) them to the received signal memory unit 50. 46e (hereinafter, simply referred to as a high frequency transmitter / receiver 46 unless otherwise specified). Here, the horizontal direction antenna element 42b is the same as the vertical direction antenna element 38b, and is shared by the vertical direction array antenna 36 and the horizontal direction array antenna 40. Further, a circuit is switched between the transmission weight multiplication unit 32 and the high frequency transmission / reception unit 46b so as to selectively supply a transmission signal to one of the vertical array antenna 36 and the horizontal array antenna 40. A switching unit 48 is provided.

  In addition, in the reception weight multiplication unit 52, which is a reception PAA processing unit that reads out the reception signal stored in the reception signal memory unit 50 at any time and multiplies a predetermined reception weight (reception PAA weight), and in the reception weight multiplication unit 52 A reception PAA weight control unit 54 that controls a reception weight to be multiplied, an AM demodulation unit 56 that detects an AM demodulated wave by demodulating the reception signal output from the reception weight multiplication unit 52, and an AM demodulation thereof An FSK decoding unit 58 that decodes the AM demodulated wave demodulated by the unit 56 using the FSK method, and a response bit string interpretation that interprets the decoded signal decoded by the FSK decoding unit 58 and reads the information signal related to the modulation of the wireless tag 14 Part 60.

  Further, as a posture sensor for detecting the posture of the antenna with reference to predetermined coordinates, a gravity sensor 62 which is a tilt sensor for detecting the tilt of the vertical array antenna 36 with reference to the direction of gravity, and And a geomagnetic sensor 64 which is an azimuth sensor for detecting the azimuth of the horizontal array antenna 40. In addition, an inclination detection unit 66 that detects the inclination of the vertical array antenna 36 and the horizontal array antenna 40 (or the RFID tag communication device 12 main body) according to the detection results of the gravity sensor 62 and the geomagnetic sensor 64; And an inclination information memory unit 68 for storing the received PAA weight according to the inclination information which is a detection result by the inclination detection unit 66.

  FIG. 4 is a diagram illustrating the configuration of the transmission weight multiplying unit 32 in detail. As shown in FIG. 4, the transmission weight multiplying unit 32 multiplies the transmission signal read from the transmission signal memory unit 30 by a predetermined transmission PAA weight, respectively, so as to correspond to the antenna elements 38 and 42. A plurality of (six in FIG. 4) multipliers 70a, 70b, 70c, 70d, 70e, and 70f (hereinafter simply referred to as multipliers 70 unless otherwise specified) are provided. Here, the multiplier 70a is the vertical antenna element 38a, the multiplier 70b is the vertical antenna element 38b, the multiplier 70c is the vertical antenna element 38c, and the multiplier 70d is the horizontal antenna element 42a. The multiplier 70e corresponds to the horizontal antenna element 42b, and the multiplier 70f corresponds to the horizontal antenna element 42c. Further, as described above, the horizontal antenna element 42b is the same as the vertical antenna element 38b, and either the multiplier 70b or the multiplier 70e is alternatively selected by switching the switching unit 48. Is supplied to the antenna element.

  FIG. 5 is a diagram illustrating in detail the configuration of the high-frequency transmitting / receiving unit 46. As shown in FIG. 5, the high-frequency transmitter / receiver 46 includes a transmission signal D / A converter 72 that converts the transmission signal supplied from the transmission weight multiplier 32 into an analog signal, and its transmission signal D / A conversion. An upconverter 74 that increases the frequency of the transmission signal analog-converted by the converter 72 by the frequency of the local transmission signal output from the local transmission signal output unit 44, and amplifies the transmission signal upconverted by the upconverter 74 A transmission signal amplifier 76 and a transmission signal output from the transmission signal amplifier 76 are supplied to the antenna elements 36 and 42, and a reception signal received by the antenna elements 36 and 42 is supplied to the reception signal amplifier 80. Directional coupler 78 and reception signal amplifier 80 for amplifying the reception signal supplied from the directional coupler 78 The downconverter 82 lowers the frequency of the reception signal output from the reception signal amplifier 80 by the frequency of the local transmission signal output from the local transmission signal output unit 44, and the reception signal downconverted by the downconverter 82. A received signal A / D converter 84 that converts the signal into a digital signal and supplies the received signal to the received signal memory unit 50.

  FIG. 6 is a diagram for explaining in detail the configuration of the reception weight multiplication unit 52. As shown in FIG. 6, the reception weight multiplication unit 52 multiplies a plurality of (six in FIG. 6) multiplications by multiplying each reception signal read from the reception signal memory unit 50 by a predetermined reception PAA weight. 86a, 86b, 86c, 86d, 86e, 86f (hereinafter simply referred to as multiplier 86 unless otherwise distinguished) and signals output from these multipliers 86 are combined and supplied to AM demodulator 56. And a synthesizer 88. Here, the multiplier 86a is the vertical antenna element 38a, the multiplier 86b is the vertical antenna element 38b, the multiplier 86c is the vertical antenna element 38c, and the multiplier 86d is the horizontal antenna element 42a. The multiplier 86e corresponds to the horizontal antenna element 42b, and the multiplier 86f corresponds to the horizontal antenna element 42c. Further, as described above, the horizontal antenna element 42b is the same as the vertical antenna element 38b, and the received signal corresponding to the antenna element is used for controlling the communication directivity in the vertical direction or communicating in the horizontal direction. Depending on whether the directivity is controlled, it can be supplied to either of the multipliers 86b and 86e.

FIG. 7 is a diagram for explaining the configuration of the wireless tag 14. As shown in FIG. 7, the wireless tag 14 includes an antenna unit 90 for transmitting and receiving signals to and from the wireless tag communication device 12 and a signal received by the antenna unit 90. An IC circuit unit 92 is provided. The IC circuit unit 92 rectifies the interrogation wave F _c received from the RFID tag communication apparatus 12 received by the antenna unit 90 and the energy of the interrogation wave F _c rectified by the rectification unit 94. Functions as a power supply unit 96 for storing, a clock extraction unit 98 that extracts a clock signal from the carrier wave received by the antenna unit 90 and supplies the clock signal to the control unit 104, and an information storage unit that can store a predetermined information signal The wireless tag 14 via the memory unit 100, the modem unit 102 connected to the antenna unit 90 for modulating and demodulating the signal, the rectifier unit 94, the clock extracting unit 98, the modem unit 102, and the like. And a control unit 104 for controlling the function. The control unit 104 performs control for storing the predetermined information in the memory unit 100 by communicating with the RFID tag communication device 12, and transmits the interrogation wave F _c received by the antenna unit 90 to the modulation / demodulation unit 102. Then, basic control such as control for reflecting and returning the response wave _Fr as the response wave _Fr is executed based on the information signal stored in the memory unit 100.

  Next, communication directivity control of the wireless tag communication device 12 will be described with reference to FIGS. The RFID tag communication device 12 controls the directivity direction of the communication according to the posture of the array antennas 36 and 40 detected by the gravity sensor 62 and the geomagnetic sensor 64. Specifically, the transmission directivity is controlled by controlling the transmission PAA weight supplied from the transmission PAA weight control unit 34 to the transmission weight multiplication unit 32. The reception directivity is controlled by controlling the reception PAA weight supplied from the reception PAA weight control unit 54 to the reception weight multiplication unit 56. Here, preferably, when the switching button 20s in the operation unit 20 is pressed and the communication directivity control operation is invalidated, the postures of the array antennas 36 and 40 described in detail below will be described. The directivity control according to is not executed.

  FIG. 8 is a diagram for explaining communication directivity control based on the gravitational direction (vertical direction) of the RFID tag communication apparatus 12. In FIG. 8, the direction of gravity is indicated by an arrow G. Further, a communication directivity direction with respect to the direction of gravity with respect to the wireless tag 14 is indicated by an arrow Dv. FIG. 8A shows a state in which the plane portion of the grip portion 18 is perpendicular to the direction of gravity, and FIG. 8B maintains the angle of the display portion 16 with respect to the grip portion 18. In this state, the wireless tag communication device 12 is tilted from the state of FIG. 8A by a predetermined angle with respect to the direction of gravity. That is, since the posture of the display unit 16 is different with respect to the direction of gravity in the state of FIG. 8A and the state of FIG. 8B, the posture of the vertical array antenna 36 built in the display unit 16 is also different. Is different. The transmission PAA weight control section 34 preferably controls the transmission PAA weight supplied to the transmission weight multiplication section 32 so that the transmission directivity based on the gravitational direction becomes a predetermined one direction. . Similarly, the reception PAA weight control unit 54 preferably controls the reception PAA weight supplied to the reception weight multiplication unit 52 so that the reception directivity based on the gravitational direction becomes a predetermined one direction. To control. For example, as shown in FIG. 8, even if the inclination of the vertical array antenna 36 with respect to the gravitational direction changes, the communication directivity direction Dv is in a direction perpendicular to the gravitational direction. Control to be maintained.

  FIG. 9 is a diagram illustrating communication directivity control based on the azimuth direction (horizontal direction) of the RFID tag communication apparatus 12. In FIG. 9, the north direction is indicated by an arrow N. In addition, a communication directivity direction based on the azimuth direction with respect to the wireless tag 14 is indicated by an arrow Dh. FIG. 9A shows a state in which the flat portion of the display unit 16 is perpendicular to the north direction, and FIG. 9B maintains the angle of the display unit 16 with respect to the grip unit 18. In this state, the RFID tag communication device 12 is tilted from the state of FIG. 9A by a predetermined angle with respect to the azimuth direction. That is, since the posture of the display unit 16 differs in the azimuth direction between the state of FIG. 9A and the state of FIG. 9B, the posture of the horizontal array antenna 40 built in the display unit 16 is also different. Is different. The transmission PAA weight control section 34 preferably controls the transmission PAA weight supplied to the transmission weight multiplying section 32 so that the transmission directivity based on the azimuth direction is a predetermined one direction. . Similarly, the reception PAA weight control unit 54 preferably controls the reception PAA weight supplied to the reception weight multiplication unit 52 so that the reception directivity based on the azimuth direction becomes a predetermined one direction. To control. For example, as shown in FIG. 9, even if the inclination of the horizontal array antenna 40 with respect to the azimuth direction changes, the directivity direction Dh of the communication is maintained in the same direction as the north azimuth. To control.

  FIG. 10 is a diagram for explaining information communication control (RFID communication control) with the wireless tag 14 by the wireless tag communication device 12, and is repeatedly executed at a predetermined cycle.

  First, in step (hereinafter, step is omitted) S1, a command bit string corresponding to a transmission signal to the wireless tag 14 is generated by the transmission bit string generation unit 24, and is encoded by the FSK encoding unit 26 using the FSK method. Is done. Next, in S <b> 2, the signal encoded in S <b> 1 is modulated by the AM modulation unit 28 by the AM method and stored in the transmission signal memory unit 30. Next, in S3, it is determined whether or not the switching button 20s is turned on so as to invalidate directivity control. If the determination in S3 is negative, directivity control command transmission control shown in FIG. 11 is performed in SA, and directivity control response reception control shown in FIG. However, if the determination in S3 is affirmative, in S4, the transmission PAA weight output from the transmission PAA weight control unit 34 is set so that the maximum directivity direction is the front. . Next, in S5, a transmission signal is read from the transmission signal memory unit 30, and transmission of the transmission signal (command transmission) is directed to the wireless tag 14 that is a search target (communication target) via the high frequency transmission / reception unit 46 and the like. ) Is executed. Next, in S6, a reply signal returned from the wireless tag 14 in response to the transmission signal transmitted in S5 is received and stored in the received signal memory unit 50 via the high frequency transmitting / receiving unit 46 and the like. . Next, in S7, the received signal is read from the received signal memory unit 50, and the received signal corresponding to each antenna element 38, 42 is multiplied by a predetermined received PAA weight so that the maximum directivity direction is the front. Thus, the reception PAA weight output from the reception PAA weight control unit 54 is controlled. Next, in S <b> 8, the combined reception signal output from the reception weight multiplication unit 52 is demodulated by the AM demodulation unit 56 using the AM method. Next, in S9, the signal demodulated in S8 is decoded by the FSK decoding unit 58 by the FSK method, and the response bit string interpretation unit 60 reads an information signal related to the modulation in the wireless tag 14. In S10, after the information read in S9 is displayed on the display of the display unit 16, this routine is terminated.

  FIG. 11 is a flowchart illustrating directivity control command transmission control that is part of the control of FIG. First, in SA1, it is determined whether transmission of a transmission signal to the wireless tag 14 is completed. When the determination of SA1 is affirmed, it is returned to the RFID communication control shown in FIG. 10, but when the determination of SA1 is negative, the directivity setting control shown in FIG. In SA2, data of one sample of the command is transmitted to the wireless tag 14 that is the search target, and then the processing after SA1 is executed again.

  FIG. 12 is a flowchart for explaining directivity setting control which is a part of the control of FIG. First, in SC1, the inclination (posture) of the RFID tag communication device 12 is detected according to the outputs from the gravity sensor 62 and the geomagnetic sensor 64. Next, in SC2, it is determined whether or not the inclination detected in SC1 is within the controllable range. If the determination in SC2 is affirmative, in SC3, transmission PAA is performed so that the maximum directivity direction is directed in a predetermined angular direction (in the first embodiment, the vertical direction is vertical to the gravity direction and the horizontal direction is north). The weight is corrected by the amount of inclination detected at SC1, and it is returned to the directivity control command transmission control shown in FIG. 11, but if the determination at SC2 is negative, it is determined as an error, In SC4, after an error message is displayed on the display unit 16, the error is terminated.

  FIG. 13 is a flowchart illustrating directivity control response reception control that is part of the control of FIG. First, in SB1, it is determined whether or not reception of a reply signal from the wireless tag 14 is completed. When the determination of SB1 is affirmed, in SB2, the reception PAA weight corresponding to the inclination information is read from the inclination information memory unit 68 for each sample, and the reception received by the antenna elements 38 and 42 is received. After the signal is multiplied by the reception PAA weight corresponding to the inclination information, the RFID communication control shown in FIG. 10 is restored. If the determination of SB1 is negative, the directivity shown in FIG. Storage control is performed, and in SB3, one sample of data is received regarding the response from the wireless tag 14 that is the search target, and then the processing from SB1 is executed again.

  FIG. 14 is a flowchart for explaining directivity storage control which is a part of the control of FIG. First, in SD1, the inclination (posture) of the RFID tag communication device 12 is detected according to the outputs from the gravity sensor 62 and the geomagnetic sensor 64. Next, in SD2, it is determined whether or not the inclination detected in SD1 is within the controllable range. If the determination in SD2 is affirmative, in SD3, the received PAA weight is corrected by the amount of inclination detected in SD1 so that the maximum directivity direction is directed to the predetermined angle direction, and the received PAA weight is converted into inclination information. After being stored in the memory unit 68, the control returns to the directivity control response reception control shown in FIG. 13. However, if the determination of SD2 is negative, it is determined that an error has occurred, and in SD4, the display unit 16 After an error message is displayed, the error is terminated.

  As described above, according to the present embodiment, the RFID tag communication device 12 includes the gravity sensor 62 and the geomagnetic sensor 64 which are posture sensors that detect the posture of the array antennas 36 and 40 with reference to predetermined coordinates. A transmission PAA weight control unit 34 and a reception PAA weight control unit 54, which are directivity control units that control the directivity direction of the communication in accordance with the posture detected by the gravity sensor 62 and the geomagnetic sensor 64. Thus, even when the attitude of the RFID tag communication apparatus 12 changes, the main lobe direction can be maintained in a predetermined direction. That is, it is possible to provide the wireless tag communication device 12 that can control the communication directivity in the optimum direction regardless of the posture of the device itself.

  In addition, since the RFID tag communication device 12 is a portable device that is movably provided with respect to a predetermined position, the portable RFID tag communication device 12 whose posture is likely to fluctuate due to handling by the user is related to the device itself. The communication directivity can be controlled in the optimum direction regardless of the posture.

  Further, since the posture sensor is a gravity sensor 62 that detects the inclination of the vertical array antenna 36 with respect to the direction of gravity, the communication directivity is set to the optimum direction regardless of the posture of the apparatus itself with respect to the direction of gravity. Can be controlled.

  Further, since the attitude sensor is the geomagnetic sensor 64 that detects the orientation of the horizontal array antenna 40 with reference to the geomagnetic direction, the communication directivity is set to the optimum direction regardless of the attitude of the apparatus itself with respect to the geomagnetic direction. Can be controlled.

  The transmission PAA weight control unit 34 and the reception PAA weight control unit 54 control the communication so that the directionality of the communication is a predetermined direction. Can be controlled in one predetermined direction.

  Further, since it has a switching function for switching the presence / absence of the directivity control operation, it is possible to easily stop the control when the communication directivity control according to the attitude variation of the apparatus itself is not necessary.

  Further, since the array antennas 36 and 40 have a plurality of antenna elements 38 and 42 that are shared for transmission of the transmission signal and reception of the reception signal, the antenna having a simple configuration is preferably used for communication directivity. Control can be performed.

  In addition, since the array antennas 36 and 40 have three antenna elements 38 and 42 that are related to directivity in a predetermined direction, the communication directivity can be controlled in a practical manner. it can.

  The array antennas 36 and 40 share five antenna elements 38a, 38b (42b), 38c, 42a and 42c by sharing one antenna element 38b (42b) with respect to the direction of gravity and the geomagnetic direction. Since the directivity direction of the communication is controlled based on the direction and the geomagnetic direction, the communication directivity related to the gravity direction and the geomagnetic direction can be controlled in a practical manner.

  In addition, the display unit 16 that displays information and images related to the communication and the grip unit 18 that is gripped when the mobile phone is carried are provided with a switching button 20s that is an operation device for the switching function. Since the portable device can be folded, the portable wireless tag communication device 12 can be provided in a practical manner.

  Next, another preferred embodiment of the present invention will be described in detail with reference to the drawings. In addition, regarding the following description, about the part which is common in the Example mentioned above, the same code | symbol is attached | subjected to drawing and the description is abbreviate | omitted.

  FIG. 15 is a diagram for explaining the configuration of the RFID tag communication apparatus 106 according to another embodiment of the present invention. As shown in FIG. 15, the RFID tag communication apparatus 106 of the present embodiment detects the signal strength of the received signal received by the array antennas 36 and 40 based on the demodulated signal output from the AM demodulator 56. The received signal strength detecting unit 108 is provided, and the received signal strength detected by the received signal strength detecting unit 108 is supplied to the received PAA weight control unit 54. In addition, the reception PAA weight control unit 54 controls the communication directivity direction to be one of a plurality of predetermined directions based on the reception signal strength detected by the reception signal strength detection unit 108. Specifically, this is a case of searching for a wireless tag 14 that is a communication target in a plurality of predetermined directions, and for specifying a plurality of predetermined directions separately from the wireless tag 14 stretched on the search object. A wireless tag 14 (hereinafter referred to as a reference tag) is installed at a predetermined position. The direction of each reference tag is detected from the direction in which each reference tag is determined to be present, that is, the direction in which the received signal strength detected by the received signal strength detection unit 108 has a maximum value when communicating with each reference tag. The communication directivity is controlled so that the direction of each reference tag becomes the direction in which each wireless tag 14 is searched. That is, the direction of the target wireless tag 14 is detected after the direction to be searched is previously determined by the reference tag.

  FIG. 16 is a diagram for explaining information communication control (RFID communication control) with the wireless tag 14 by the wireless tag communication device 106, which is repeatedly executed at a predetermined cycle. Regarding the control shown in FIG. 16, steps common to the control of FIG. 10 described above are denoted by the same reference numerals and description thereof is omitted.

  First, in S11, it is determined whether or not it is the reference tag detection mode. When the determination at S11 is negative, the processing after S1 described above is executed. When the determination at S11 is affirmative, the reference tag direction detection control shown in FIG. In step S12, it is determined whether all reference tags have been detected. If the determination in S12 is negative, the processing after SE is executed again. If the determination in S12 is affirmative, the detection result of the reference tag is displayed on the display unit 16 in S13. After that, the above-described processing after S1 is executed. However, the predetermined angular direction of SC3 and SD3 is the direction of each reference tag detected by SE. Further, following S9 described above, in S14, it is determined whether or not the detection of the wireless tags 14 in all the reference tag directions is completed. When the determination at S14 is negative, the above-described processing after S1 is executed again. However, when the determination at S14 is positive, this routine is executed after the processing at S10 described above is executed. Be terminated.

FIG. 17 is a flowchart for explaining the direction detection control of the reference tag, which is a part of the RFID communication control shown in FIG. First, in SE1, the initial value of the maximum directivity direction θ _MAIN is set to a predetermined value (for example, θ _MAIN = −45 °) in the transmission PAA weight control unit 34 and the reception PAA weight control unit 54 and stored in a register. The Next, in SE2, the value of the register of the transmission PAA weight control unit 34 is multiplied by the transmission signal corresponding to each of the antenna elements 38 and 42 in the transmission weight multiplication unit 32 and transmitted toward the reference tag. Next, in SE3, a reply signal returned from the reference tag in accordance with the transmission signal transmitted in SE2 is received and stored in the received signal memory unit 50 via the high frequency transmitting / receiving unit 46 and the like. Next, in SE4, the reception signal stored in SE3 is read from the reception signal memory unit 50. Next, in SE5, the register value of the reception PAA weight control unit 54 is multiplied by the reception signals corresponding to the antenna elements 38 and 42 in the reception weight multiplication unit 56, and the combined output Y is obtained by synthesizing these reception signals. Is calculated. Next, at SE6, the combined output Y calculated at SE5 is demodulated by the AM demodulator 56. Next, in SE7, it is determined whether or not the combined output Y calculated in SE5 has a maximum value. If the determination in SE7 is negative, the processing from SE9 is executed. If the determination in SE7 is positive, the maximum directivity in which the reference tag direction θ _{REF_MAX} is set in SE8. After the direction θ _MAIN (θ _REF — _MAX = θ _MAIN ) is set, the maximum directivity direction θ _MAIN is updated (for example, θ _MAIN = θ _MAIN +) in the transmission PAA weight control unit 34 and the reception PAA weight control unit 54 in SE9. 15 °) and stored in the register. Next, in SE10, it is determined whether or not the set directivity direction θ _MAIN is greater than a predetermined value (for example, θ _MAIN > 45 °). When the determination of SE10 is negative, the processing after SE2 is executed again. However, when the determination of SE10 is positive, the maximum directivity direction is the reference tag direction θ _{REF_MAX} in _SE11 . AM demodulated data is decoded by the FSK decoding unit 58. Next, in SE12, it is determined whether or not the decrypted data decrypted in SE11 is normal. If the determination in SE12 is affirmative, in SE13, after the predetermined angle direction is set to the reference tag direction θ _{REF_MAX} , the RFID communication control shown in FIG. 16 is restored, but the determination in SE12 is denied. In this case, it is determined that an error has occurred, and in SD4, an error is displayed on the display unit 16, and the error is terminated.

  As described above, in the RFID tag communication apparatus 106 of the present embodiment, the transmission PAA weight control unit 34 and the reception PAA weight control unit 54, which are directivity control units, determine whether the communication directivity direction is any one of a plurality of predetermined directions. In the case where there are a plurality of wireless tags 14 to be communicated, the directionality of communication directivity with the wireless tags 14 is the highest regardless of the attitude of the device itself. Can be controlled.

  Next, still another embodiment of the present invention will be described with reference to FIG. In the first and second embodiments described above, the RFID tag communication device 12 reads information stored in the RFID tag 14 by communicating information with the RFID tag 14. Although it is a reading device, the RFID tag communication device 12 of the present embodiment is a RFID tag writing device for writing predetermined information to the RFID tag 14 by communicating information with the RFID tag 14. Or it functions as a reader / writer capable of both reading and writing. Further, it has an automatic switching function that enables the above-described directivity control operation when information is written to the wireless tag 14.

  FIG. 18 is a flowchart for explaining the directivity control presence / absence switching control by the RFID tag communication apparatus 12 having the function of writing information to the RFID tag 14, and is repeatedly executed at a predetermined cycle.

  First, in SF1, it is determined whether or not the transmission signal transmitted to the wireless tag 14 includes a write command for writing predetermined information to the wireless tag 14. If the determination of SF1 is affirmative, the routine is terminated after the directivity control operation according to the attitude of the array antennas 36 and 40 described above is validated in SF2, but the determination of SF1 is not completed. When the result is negative, the routine is terminated after the directivity control operation according to the attitude of the array antennas 36 and 40 described above is invalidated at SF3.

  As described above, the wireless tag communication device 12 according to the present embodiment has a function of writing predetermined information to the wireless tag 14, and performs the directivity control operation described above when writing information to the wireless tag 14. Since it is effective and requires a large amount of power supply, the communication directivity is controlled in the optimum direction when writing information to the wireless tag 14 that particularly requires the control of the communication directivity. Can do.

  The preferred embodiments of the present invention have been described in detail with reference to the drawings. However, the present invention is not limited to these embodiments, and may be implemented in other modes.

  For example, in the above-described embodiment, the transmission weight multiplication unit 32, the transmission PAA weight control unit 34, the reception weight multiplication unit 52, the reception PAA weight control unit 54, and the like are all provided as individual control devices. The present invention is not limited to this, for example, a so-called microcomputer system that includes a CPU, a ROM, a RAM, and the like, and performs signal processing according to a program stored in advance in the ROM while using a temporary storage function of the RAM. As a control function of a DSP (Digital Signal Processor), the transmission weight multiplication unit 32, the transmission PAA weight control unit 34, the reception weight multiplication unit 52, the reception PAA weight control unit 54, and the like are functionally included. I do not care. The control by these control units may be digital signal processing or analog signal processing.

  In the above-described embodiment, the portable wireless tag communication device 12 provided so as to be movable with respect to a predetermined position has been described. However, the present invention is a stationary type provided with a fixed position with respect to a predetermined position. The present invention can also be applied to a wireless tag communication device. When the base on which the wireless tag communication device is stationary is movable with respect to the wireless tag 14 that is the detection target, the relative relationship between the antenna provided in the wireless tag communication device and the wireless tag 14 by the movement Although the direction varies, an optimal communication state can always be established by applying the present invention.

  In the above-described embodiment, the wireless tag communication device 12 or the like transmits the transmission signal and receives a return signal returned from the wireless tag 14 according to the transmission signal. , 40 may be provided, but a transmitting array antenna and a receiving array antenna may be provided separately.

  In the above-described embodiment, the wireless tag communication device 12 or the like controls the transmission PAA weight output from the transmission PAA weight control unit 34 in accordance with the posture detected by the gravity sensor 62 and the geomagnetic sensor 64. The transmission directivity is controlled by controlling the reception directivity by controlling the reception PAA weight output from the reception PAA weight control unit 54, but the transmission directivity and the reception directivity are controlled. Only one of them may be controlled.

  In addition, although not illustrated one by one, the present invention is implemented with various modifications within a range not departing from the gist thereof.

It is a figure explaining the radio | wireless tag communication system with which this invention is used suitably. It is a perspective view explaining the external appearance of the RFID tag communication apparatus which is one Example of this invention. It is a figure explaining the structure of the radio | wireless tag communication apparatus of FIG. It is a figure explaining in detail the structure of the transmission weight multiplication part with which the RFID tag communication apparatus of FIG. 3 was equipped. It is a figure explaining in detail the structure of the high frequency transmission / reception part with which the RFID tag communication apparatus of FIG. 3 was equipped. It is a figure explaining in detail the structure of the reception weight multiplication part with which the RFID tag communication apparatus of FIG. 3 was equipped. It is a figure explaining the structure of the wireless tag which is a communication object of the wireless tag communication apparatus of FIG. It is a figure explaining the communication directivity control on the basis of the gravity direction (vertical direction) by the wireless tag communication apparatus of FIG. It is a figure explaining the communication directivity control on the basis of the geomagnetic direction (azimuth | direction direction) by the radio | wireless tag communication apparatus of FIG. It is a figure explaining the information communication control (RFID communication control) between the wireless tag of FIG. 7 by the wireless tag communication apparatus of FIG. It is a flowchart explaining the directivity control command transmission control which is a part of control of FIG. It is a flowchart explaining the directivity setting control which is a part of control of FIG. It is a flowchart explaining the directivity control response reception control which is a part of control of FIG. It is a flowchart explaining the directivity memory | storage control which is a part of control of FIG. It is a figure explaining the structure of the RFID tag communication apparatus which is the other Example of this invention. It is a figure explaining the information communication control (RFID communication control) between the wireless tag of FIG. 7 by the wireless tag communication apparatus of FIG. It is a flowchart explaining the direction detection control of the reference tag which is a part of RFID communication control shown in FIG. It is a flowchart explaining the directivity control presence / absence switching control by the wireless tag communication apparatus having an information writing function to the wireless tag of FIG.

Explanation of symbols

12, 106: RFID tag communication device 14: RFID tag 16: display unit 18: gripping unit 20: operation unit 20s: switching button (switching device)
34: Transmission PAA weight control unit (directivity control unit)
36: Array antenna for vertical direction 38: Antenna element for vertical direction 40: Array antenna for horizontal direction 42: Antenna element for horizontal direction 54: Reception PAA weight control unit (directivity control unit)
62: Gravity sensor (tilt sensor)
64: Geomagnetic sensor (orientation sensor)

Claims (12)

An antenna is integrally provided, and a transmission signal is transmitted to the wireless tag, and a reply signal returned from the wireless tag according to the transmission signal is received to communicate information with the wireless tag. A wireless tag communication device,
An attitude sensor that is provided in the RFID tag communication device and detects an attitude of the antenna with reference to predetermined coordinates;
A wireless tag communication device comprising: a directivity control unit that controls a directivity direction of the communication according to a posture detected by the posture sensor.   The wireless tag communication device according to claim 1, wherein the wireless tag communication device is a portable device provided to be movable with respect to a predetermined position.   The wireless tag communication device according to claim 1, wherein the attitude sensor is an inclination sensor that detects an inclination of the antenna with respect to a direction of gravity.   The wireless tag communication device according to claim 1 or 2, wherein the attitude sensor is an orientation sensor that detects the orientation of the antenna with reference to a geomagnetic direction.   The RFID tag communication apparatus according to claim 1, wherein the directivity control unit controls the communication so that a directivity direction of the communication is a predetermined one direction.   5. The RFID tag communication apparatus according to claim 1, wherein the directivity control unit performs control so that a directivity direction of the communication is any one of a plurality of predetermined directions.   The wireless tag communication device according to claim 1, wherein the wireless tag communication device has a switching function for switching whether or not the directivity control unit operates.   The wireless tag communication device according to claim 1, wherein the antenna includes a plurality of antenna elements shared for transmission of the transmission signal and reception of the reception signal.   9. The wireless tag communication apparatus according to claim 8, wherein the antenna has at least three antenna elements involved in directivity with respect to a predetermined direction.   9. The antenna has five antenna elements sharing one antenna element with respect to the gravitational direction and the geomagnetic direction, and controls the directivity direction of the communication based on the gravitational direction and the geomagnetic direction. Or 9 RFID tag communication devices. A display unit for displaying an image relating to the communication;
A gripping part for gripping when carrying,
The RFID tag communication device according to any one of claims 7 to 10, wherein the RFID tag communication device is a foldable portable device in which an operation device for the switching function is provided in the grip portion.   The wireless tag communication device has a wireless tag writing function capable of writing predetermined information to the wireless tag, and the switching function performs an operation of the directivity control unit when writing information to the wireless tag. 12. The wireless tag communication device according to claim 7, wherein the wireless tag communication device is valid.

Images