Handheld wireless tag reader device

Abstract

To provide a wireless tag communication device that can guide operators to perform appropriate operations. [Solution] According to the embodiment, the wireless tag communication device includes a communication control circuit, a sensor, and a processor. The communication control circuit communicates with the wireless tag via an antenna. The sensor detects the amount of change in the antenna's orientation. The processor outputs an alert when the amount of change in the antenna's orientation detected by the sensor is smaller than a reference value.

Description

Technical Field

[0001] Embodiments of the present invention relate to a wireless tag communication device.

Background Art

[0002] Conventionally, there is a wireless tag communication device for the purpose of reading RFID tags (hereinafter also referred to as wireless tags) located at unspecified positions. The wireless tag communication device communicates with a specific RFID tag while changing the orientation of the antenna by the operation of an operator. The wireless tag communication device notifies the operator of information indicating the position where a specific RFID tag exists, estimated based on the communication state with the specific RFD tag.

[0003] As described above, in the wireless tag communication device, it is necessary to change the orientation of the antenna by the operation of the operator in order to estimate the position where a specific RFID tag exists. However, there is a problem that in the conventional wireless tag communication device, the operator may not know how to operate in order to appropriately change the orientation of the antenna.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In order to solve the above problems, an object is to provide a wireless tag communication device that can guide an operator to perform an appropriate operation.

Means for Solving the Problems

[0006] According to one embodiment, the wireless tag communication device includes a communication control circuit, a sensor, and a processor. The communication control circuit communicates with the wireless tag via an antenna. The sensor detects the amount of change in the antenna's orientation. The processor outputs an alert when the amount of change in the antenna's orientation detected by the sensor is smaller than a reference value. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a schematic block diagram showing an example of the configuration of the control system in a wireless tag reader according to the embodiment. [Figure 2] Figure 2 is an external view showing an example of the external configuration of a wireless tag reader according to an embodiment. [Figure 3] Figure 3 shows an example of the operation guide displayed by the wireless tag reader according to the embodiment while it is operating in RFID tag search mode. [Figure 4] Figure 4 is a flowchart illustrating a first example of operation in the wireless tag reader according to this embodiment. [Figure 5] Figure 5 is a flowchart illustrating a second example of operation in the wireless tag reader according to the embodiment. [Figure 6] Figure 6 is a flowchart illustrating a third example of operation in the wireless tag reader according to the embodiment. [Figure 7] Figure 7 is a flowchart illustrating a fourth example of operation in the wireless tag reader according to the embodiment. [Figure 8] Figure 8 is a flowchart illustrating a first example of the process by which the wireless tag reader according to the embodiment estimates the tag direction. [Figure 9] Figure 9 is a flowchart illustrating a second example of the process by which the wireless tag reader according to the embodiment estimates the tag direction. [Modes for carrying out the invention]

[0008] The embodiments will be described below with reference to the drawings. First, the configuration of the wireless tag reader (wireless tag communication device) 10 according to this embodiment will be described. Figure 1 is a schematic block diagram showing an example of the configuration of a wireless tag reader 10 according to an embodiment. The wireless tag reader 10 according to this embodiment is a wireless tag communication device that communicates with an RFID tag (wireless tag). The wireless tag reader 10 reads tag information recorded on the RFID tag by communicating with the RFID tag. The wireless tag reader 10 estimates information about the location of the RFID tag, such as the direction and distance, from the reading result of the RFID tag. The wireless tag reader 10 informs the operator of the information (direction and distance) about the location of the RFID tag estimated from the reading result.

[0009] An RFID tag is a wireless communication device that operates using radio waves (output signals) from a wireless tag reader 10. The RFID tag includes a processor, memory, communication circuitry, and antenna. In response to a read command from the wireless tag reader 10, the RFID tag outputs a response signal containing tag information stored in its own memory. For example, an RFID tag is attached to an item such as a product or part. An RFID tag attached to an item stores tag information, including information identifying the item, in its internal memory.

[0010] The wireless tag reader 10 according to this embodiment is operated by an operator. The wireless tag reader 10 is a device that changes the orientation of the antenna 25 used for communication with the RFID tag by the operator's operation. For example, the wireless tag reader 10 is a handheld device that the operator holds and operates. Alternatively, the wireless tag reader 10 may be mounted on a mobile device that the operator uses to control the orientation of the antenna.

[0011] The wireless tag reader 10 according to this embodiment reads RFID tags attached to items while changing its position and antenna orientation according to the operator's operation. The wireless tag reader 10 reads the tag information recorded on the RFID tag by receiving a response signal from the RFID tag within the reading range. As a result of reading the RFID tag, the wireless tag reader 10 also acquires information such as the RSSI (Received Signal Strength Indicator) value, which indicates the strength of the received signal received from the RFID tag, along with the tag information.

[0012] For example, the wireless tag reader 10 is operated as a search device for finding items with RFID tags attached within a predetermined area such as a warehouse or store. As a search device, the wireless tag reader 10 continuously reads the target RFID tags while changing its position and antenna orientation according to the operator's operation. Based on the reading results of the target RFID tags, the wireless tag reader 10 estimates the location (direction, distance, etc.) of the RFID tags. The wireless tag reader 10 may also estimate the change in relative position to the RFID tags based on the change in the intensity of the received signal over time. The wireless tag reader 10 informs the operator of information such as the direction in which the RFID tags are located and the distance to the RFID tags, which are estimated from the reading results.

[0013] In the configuration example shown in Figure 1, the wireless tag reader 10 includes a processor 21, memory 22, sensor 23, communication control circuit 24, antenna 25, communication interface (I / F) 26, interface 27, information terminal 28, and power supply 29.

[0014] The processor 21 controls each component. The processor 21 includes, for example, an arithmetic circuit such as a CPU. The processor 21 performs control of each component and various data processing by executing a program. The processor 21 may also be equipped with internal memory.

[0015] The processor 21 executes various processes by executing programs stored in the memory 22 and the like. For example, the processor 21 interprets commands from the host device 11 received by the communication I / F 26 and executes processes according to the commands.

[0016] The memory 22 includes various memories. For example, the memory 22 includes memories such as ROM, RAM, and NVM. The ROM is a non-volatile memory that cannot be rewritten. The ROM stores programs executed by the processor 21 and the like. The RAM is a volatile memory that temporarily stores data. The RAM operates as a working memory or a buffer memory. The NVM is a rewritable non-volatile memory. The NVM stores information such as programs, control information, setting information, and reading results.

[0017] The sensor 23 detects the movement of the wireless tag reader device 10. The sensor 23 includes a sensor that detects a change in the orientation of the antenna 25 provided in the wireless tag reader device 10. For example, the sensor 23 is an acceleration sensor, a gyro sensor, or a geomagnetic (azimuth) sensor. The sensor 23 may be configured to include multiple types of sensors. Note that the sensor 23 may be provided in the information terminal 28.

[0018] The communication control circuit 24 and the antenna 25 constitute an RFID interface for communicating with an RFID tag. The communication control circuit 24 includes a control circuit for communicating with an RFID tag via the antenna 25. The communication control circuit 24 transmits the transmission signal (radio wave) supplied from the processor 21 from the antenna 25 at a set output value. The antenna 25 outputs the transmission signal supplied from the communication control circuit 24 as a radio wave that can be received by the RFID tag.

[0019] The communication control circuit 24 not only outputs a transmission signal to the antenna 25, but also supplies the signal received by the antenna 25 to the processor 21 as received data. In other words, the communication control circuit 24 receives a response signal from the RFID tag via the antenna 25, processes the received response signal (received signal) via the antenna 25, and supplies it to the processor 21. For example, the communication control circuit 24 supplies the processor 21 with tag information contained in the received signal from the RFID tag and the RSSI value indicating the strength of the received signal.

[0020] Communication I / F26 is an interface for communicating with external devices. Communication I / F26 is a communication interface for communicating with higher-level devices 11, such as servers. Communication I / F26 may be a wired communication interface or a wireless communication interface.

[0021] Interface 27 is an interface for connecting to the information terminal 28. Interface 27 only needs to be compatible with the interfaces provided by the information terminal 28. For example, interface 27 may connect by physically contacting an interface provided by the information terminal 28, such as a USB (Universal Serial Bus) interface or a LAN interface. Alternatively, interface 27 may communicate wirelessly, such as with a Bluetooth® interface or a Wi-Fi interface.

[0022] The information terminal 28 is a device equipped with a display 114 and an input device 115, etc. The information terminal 28 operates as a user interface for the wireless tag reader 10, acting as both a display and an input device. The information terminal 28 may also be a portable information processing device such as a smartphone or a tablet PC.

[0023] In the configuration example shown in Figure 1, the information terminal 28 includes a processor 111, memory 112, interface (I / F) 113, display 114, and input 115, among others. The processor 111 controls each component and performs data processing. The processor 111 is, for example, a CPU. The processor 111 performs various operations by executing programs stored in the memory 112.

[0024] Interface 113 is an interface (second communication interface) for communicating with the processor 21. Interface 113 can be any interface that corresponds to interface 27. For example, interface 113 can be a LAN, USB, Bluetooth (registered trademark), or Wi-Fi interface.

[0025] The display unit 114 is a device that displays information. For example, the display unit 114 displays the detection results of RFID tags (e.g., the location of the RFID tags). The input unit 115 is a device for the operator to input operation instructions, etc. The display unit 114 and the input unit 115 are configured, for example, by a display device with a touch panel.

[0026] The power supply 29 provides the power necessary to operate the wireless tag reader 10. The power supply 29 supplies power to each part of the wireless tag reader 10. In a handheld wireless tag reader 10, the power supply 29 is, for example, comprised of a rechargeable battery.

[0027] Next, an example of the configuration of the communication control circuit 24 in the wireless tag reader 10 according to the embodiment will be described. As shown in Figure 1, the communication control circuit 24 includes a modulation circuit 41, an amplification circuit 42, a coupler 43, an amplification circuit 44, a demodulation circuit 45, an output setting circuit 46, and a level detection circuit 47. In the configuration example shown in Figure 1, the communication control circuit 24 processes signals transmitted to the RFID tag via the antenna 25 and signals received from the RFID tag.

[0028] The modulation circuit 41 is a circuit that modulates a waveform signal (carrier wave) with input data. The modulation circuit 41 modulates the carrier wave with the transmission data provided by the processor 21. The amplification circuit 42 is a transmitting-side amplification circuit that amplifies the input signal. The amplification circuit 42 amplifies the output signal of the modulation circuit 41. The coupler 43 includes a circuit that supplies the output signal of the amplification circuit 42 to the antenna 25. With these configurations, the communication control circuit 24 outputs a carrier wave modulated with the transmission data from the antenna 25.

[0029] The RFID tag receives radio waves as a transmission signal from antenna 25. The RFID tag recognizes, for example, a read command included in the transmission signal sent from antenna 25. Upon recognizing the read command, the RFID tag outputs data (tag information) stored in its memory via radio waves, for example, by backscatter modulation.

[0030] Antenna 25 receives radio waves as received signals output by the RFID tag. Coupler 43 includes a circuit that acquires the received signal received by antenna 25 and supplies the acquired received signal to amplification circuit 44. Coupler 43 is, for example, a directional coupler or an isolator. Amplification circuit 44 is a receiving-side amplification circuit that amplifies the input signal. Amplification circuit 44 amplifies the received signal received by antenna 25. Demodulation circuit 45 is a circuit that demodulates data superimposed on the waveform signal (carrier wave). Demodulation circuit 45 demodulates the data (tag information) contained in the received signal amplified by amplification circuit 44.

[0031] The antenna 25 can be any antenna that transmits and receives radio waves for communication with the RFID tag. The antenna 25 can transmit a transmission signal to the RFID tag and receive radio waves output by the RFID tag as a reception signal. In this embodiment, the antenna 25 is directional. The antenna 25 is arranged to transmit electromagnetic waves toward the reading area centered on the direction in which the directivity is strongest (direction a shown in Figure 2). The wireless tag reader 10 is configured to communicate with RFID tags attached to all products placed in the reading area via the antenna 25. The antenna 25 is, for example, a planar antenna. However, the antenna 25 is not limited to a specific configuration.

[0032] The output setting circuit 46 is a circuit that sets the strength (output value) of the signal to be output. The output setting circuit 46 controls the amplification circuit 42 so that the strength of the signal to be output becomes the set output value. The amplification circuit 42 amplifies the signal supplied from the modulation circuit 41 to the output value set by the output setting circuit 46 and outputs it to the coupler 43. As a result, the antenna 25 emits an output signal (radio wave) with the output value set by the output setting circuit 46, supplied from the amplification circuit 42 via the coupler 43.

[0033] The level detection circuit 47 is a circuit that detects (measures) the strength of a signal. The level detection circuit 47 detects the strength of the signal input to the amplification circuit 44. The received signal received by the antenna 25 is input to the amplification circuit 44 via the coupler 43. In other words, the level detection circuit 47 detects information to identify the RSSI value, which indicates the strength of the received signal (response signal from the RFID tag) received by the antenna 25.

[0034] Next, an example of the operation of the wireless tag reader 10 according to this embodiment will be described. Figure 2 shows an example of the external configuration of the wireless tag reader 10 according to this embodiment. The wireless tag reader 10 shown in Figure 2 is a handheld device operated by an operator while being held in their hand. The wireless tag reader 10 shown in Figure 2 is used, for example, as a search device to locate RFID tags or items to which RFID tags are attached.

[0035] In the configuration example shown in Figure 2, the wireless tag reader 10 is configured to operate with an information terminal 28 set on a reader device (base device) 120. The reader device 120 is a device that has all the components except for the information terminal 28 shown in Figure 1. The reader device 120 has a housing on which an antenna 25 is installed. For example, in the reader device 120, the antenna 25 is positioned so that its directivity is strongest in the direction of arrow a shown in Figure 2. Here, the direction of arrow a is assumed to be the front (forward) direction of the wireless tag reader 10. Also, the front direction of the wireless tag reader 10 is assumed to be the direction of the antenna 25.

[0036] The reader device 120 has a gripping section 121 and a holding section 122 in addition to the control system configuration shown in Figure 1. The gripping section 121 is the part that the operator grips. The holding section 122 is made up of a jig that holds the information terminal 28. The holding section 122 holds the information terminal 28 so that the display screen of the display unit 114 faces the operator who is gripping the gripping section 121. The wireless tag reader device 10 is operated by the operator gripping the gripping section 121 with the information terminal 28 set in the holding section 122.

[0037] The wireless tag reader 10 is moved by an operator while the information terminal 28 is attached to it. The wireless tag reader 10 continuously reads RFID tags while being operated by the operator. For example, the operator holding the gripping part 121 changes the orientation of the antenna 25 provided on the reader device 120. The wireless tag reader 10 detects the change in the orientation of the antenna 25 caused by the operator's operation using the sensor 23. The wireless tag reader 10 reads the RFID tags while detecting the change in the orientation of the antenna.

[0038] The wireless tag reader 10 repeatedly reads a specific RFID tag while changing the orientation of the antenna 25 in response to the operator's input and saves the reading results. For example, the wireless tag reader 10 acquires reading results when reading a specific RFID tag while changing the orientation of the antenna 25. In addition to the tag information obtained from the RFID tag, the wireless tag reader 10 acquires information such as the RSSI value indicating the strength of the signal received from the RFID tag as part of the reading results. Furthermore, the wireless tag reader 10 also acquires information such as the amount of change in orientation detected by the sensor 23 as part of the reading results.

[0039] The wireless tag reader 10 estimates the direction in which an RFID tag is located (tag direction) from the reading result of the RFID tag. For example, the wireless tag reader 10 estimates the tag direction in which the RFID tag is located by the median value of the range of directions (antenna orientation) in which a particular RFID tag was read. Alternatively, the wireless tag reader 10 may estimate the tag direction in which the RFID tag is located by the direction (antenna orientation) in which the RSSI value was maximized in the reading result of reading a particular RFID tag.

[0040] The wireless tag reader 10 detects changes in the orientation of the antenna 25 using the sensor 23. If the amount of change in the orientation of the antenna 25 detected by the sensor 23 is below a reference value, the wireless tag reader 10 notifies an alert prompting the user to change the orientation of the antenna 25. For example, if the change in the orientation of the antenna 25 is below a reference value, the wireless tag reader 10 displays an operation guide on the display 114 prompting the user to change the orientation of the antenna 25.

[0041] Figure 3 shows an example of the operation guide displayed on the display unit 114 by the wireless tag reader 10. The example shown in Figure 3 is an example of displaying operation instructions on a screen that shows the search results for RFDI tags. In the search mode for a specific RFID tag, the wireless tag reader 10 displays a display screen on the display unit 114 showing the RFID tag search results, as shown in Figure 3. In the search mode, the wireless tag reader estimates the location (direction and distance) of a specific RFID tag from the RFID tag reading results. The wireless tag reader 10 displays information indicating the location of the specific RFID tag estimated from the RFID tag reading results on the display unit 114 as the search result.

[0042] In the display example shown in Figure 3, the display unit 114 displays the reading range 202 read by the wireless tag reader 10 superimposed on concentric circles 201 centered on the position of the wireless tag reader 10. For example, the display unit 14 displays the reading range 202 on the concentric circles 201 such that the top is in front of the wireless tag reader 10 (in the direction of arrow a shown in Figure 2). The display unit 114 displays a mark 203 indicating the position of the RFID tag read within the reading range 202 on the concentric circles 201.

[0043] For example, the wireless tag reader 10 estimates the distance from the wireless tag reader 10 to the RFID tag based on the RSSI value included in the RFID tag reading result. The display unit 114 displays a mark 203 on a concentric circle 201 centered on the position of the wireless tag reader 10, at a position corresponding to the estimated direction and distance. In this way, the display unit 114 can inform the operator of the direction and distance where the RFID tag is located by displaying the mark 203 on the reading range 202.

[0044] Furthermore, the display unit 114 displays the display area 211, the display area 212, the search start button 231, and the end button 232 in the display example shown in Figure 3. Display field 211 displays the part number of the RFID tag to be searched. Display field 212 displays the serial number of the RFID tag to be searched.

[0045] The search start button 231 and the search end button 232 are buttons that the operator can control via the touch panel, which serves as the input device 115. The search start button 231 is used by the operator to initiate the search for RFID tags. The search end button 232 is used by the operator to initiate the search for RFID tags. The operator can search for RFID tags by operating the wireless tag reader 110 while viewing a screen like the one shown in Figure 3.

[0046] Furthermore, the display unit 114 displays operation instructions in the display area 241, as shown in the display example in Figure 3, prompting the user to operate the wireless tag reader 10. The wireless tag reader 10 needs to read RFID tags while changing the orientation of the antenna 25 in order to search for RFID tags. The wireless tag reader 10 according to this embodiment notifies an alert prompting the user to change the orientation of the antenna 25. The operation instructions displayed in the display area 241 shown in Figure 3 are an example of an alert prompting the user to change the orientation of the antenna.

[0047] For example, if the amount of change in the orientation of the antenna 25 (or pace device 120 equipped with the antenna 25) is below a predetermined threshold, the wireless tag reader 10 displays an operation guide on the display 114 prompting the user to change the orientation of the antenna 25. When the wireless tag reader 10 is operating in search mode, it displays an operation guide in the display field 241 on the display screen as shown in Figure 3. In the example shown in Figure 3, the wireless tag reader 10 displays "Shake the reader (wireless tag reader) left and right" in the display field 241.

[0048] Next, the operation of the wireless tag reader 10 according to this embodiment will be described. Figure 4 is a flowchart illustrating a first example of operation of the wireless tag reader 10 according to this embodiment. The processor 21 of the wireless tag reader 10 operates in search mode by operator input. The processor 21 receives settings from the operator for the RFID tags to be searched. After setting the RFID tags to be searched, the processor 21 receives an instruction from the operator to start the search. For example, the processor 21 receives an instruction to start the search via the search start button 231 on the display screen shown in Figure 3 on the display unit 114.

[0049] The processor 21 of the wireless tag reader 10 executes the RFID tag reading process in response to an operator's instruction to start a search (ACT 11). The processor 21 stores the reading results of RFID tags within the reading range (communication range) of the communication control circuit 24 and antenna 25 in the memory 22.

[0050] The processor 21 stores information such as tag information, orientation (reading direction), output value, and RSSI value in the memory 22 as the reading result for each RFID tag. Tag information is information output by the RFID tag in response to a response request (read command) from the wireless tag reader 10. Tag information consists of, for example, a header, a product code, and a serial number. The header indicates the format of the tag information and the range of the product code in the tag information. The product code is information used to identify the product (item). The serial number is an identification number assigned to each individual product.

[0051] The orientation (reading direction) is information indicating the orientation of the antenna 25 (the orientation of the wireless tag reader 10) when the RFID tag is read. The processor 21 acquires information indicating the orientation of the antenna 25 detected by the sensor 23. For example, the processor 21 acquires information indicating the orientation of the antenna 25 by detecting the amount of variation in orientation (angle of variation) relative to a reference orientation using the sensor 23.

[0052] The output value is the strength of the output signal (radio wave) emitted from the antenna 25 when an RFID tag is read. The output value is set by the output setting circuit 46 of the communication control circuit 24 according to instructions from the processor 21. The processor 21 identifies the output value set in the communication control circuit 24.

[0053] The RSSI value is information indicating the strength of the received signal from each RFID tag. The RSSI value is detected from the received signal of each RFID tag by the level detection circuit 47. The processor 21 acquires the RSSI value detected by the level detection circuit 47.

[0054] When the processor 21 acquires the reading result of each RFID tag within the reading range, it measures (detects) the swing amount, which is the change in the orientation of the antenna 25 (ACT12). The processor 21 measures (detects) the swing amount based on the change in orientation detected by the sensor 23. For example, the processor 21 measures the swing amount by the change (difference) between the orientation when the RFID tag was read and the orientation a predetermined time earlier. Alternatively, the processor 21 may measure the swing amount by the difference (change) between the orientation when the search started and the orientation when the RFID tag was read. Alternatively, the processor 21 may measure the swing amount by the difference between the orientation when the RFID tag was read and the orientation when the RFID tag was read immediately before.

[0055] After measuring the swing amount, the processor 21 determines whether or not it has read the RFID tag to be searched (ACT13). If the RFID tag to be searched has not been read (ACT13, NO), the processor 21 proceeds to ACT19, which will be described later.

[0056] When the RFID tag to be searched is read (ACT13, YES), the processor 21 estimates the direction in which the RFID tag is located (tag direction) (ACT14). An example of the process for estimating the tag direction will be explained later. However, the process for estimating the tag direction in ACT15 may be omitted.

[0057] Once the tag direction is estimated, the processor 21 stores the reading results of the target RFID tag, including the estimated tag direction, in the memory 22 (ACT15). As a result, the memory 22 accumulates the reading results of the target RFID tags.

[0058] After saving the reading result of the RFID tag to be searched, the processor 21 determines whether the communication status with the RFID tag to be searched exceeds a reference level (ACT16). For example, the processor 21 determines whether the RSSI value of the received signal from the RFID tag to be searched exceeds a reference level as the communication status. Here, the processor 21 may set a reference level to compare with the communication status according to the output value set in the communication control circuit 24.

[0059] If the communication status exceeds the reference level (ACT16, YES), the processor 21 determines whether the output value (magnitude of the output signal) of the transmission signal set in the communication control circuit 24 is the minimum value that can be set (ACT17).

[0060] If the output value of the transmitted signal is not the minimum value (ACT17, YES), the processor 21 reduces the output value of the output signal set in the communication control circuit 24 (ACT18). Here, the processor 21 gradually reduces the output value until it reaches the minimum configurable value. Reducing the output value reduces the reading range of the RFID tag by the wireless tag reader 10. In other words, by gradually reducing the output value, the processor 21 gradually limits the reading range in which the target RFID tag is read. This allows the wireless tag reader 10 to pinpoint the location where the target RFID tag exists.

[0061] If the output value of the transmitted signal is at its minimum (ACT17, NO), the processor 21 notifies the detection result of the RFID tag to be searched (ACT22). For example, the processor 21 displays information on the display 114 indicating the location of the RFID tag to be searched, estimated from the reading result at the minimum output value. Alternatively, the processor 21 may also notify the host device 11 via the communication interface 26 of the information indicating the detection result of the RFID tag to be searched.

[0062] The processor 21 sets a reference value as a threshold for the swing amount according to the RFID tag reading status, the estimated tag direction result, the output value, and the estimated distance to the RFID tag (ACT19). For example, if the RFID tag to be searched cannot be read (ACT13, NO), the processor 21 sets a predetermined reference value for the swing amount to read a wider area (ACT19).

[0063] Furthermore, if the tag direction is estimated, the processor 21 sets a reference value for the swing amount based on the estimated tag direction. For example, the processor 21 sets a reference value for the swing amount based on the estimated tag direction if the communication state is below a reference level (ACT16, NO) or if the output value of the transmitted signal is reduced.

[0064] Furthermore, the processor 21 may set a reference value for the swing amount according to various conditions. Specifically, the processor 21 may set a reference value according to the output value of the transmission signal set in the communication control circuit 24. For example, the processor 21 may decrease the reference value for the swing amount as the output value of the transmission signal decreases. Alternatively, the processor 21 may set a reference value according to the distance to the RFID tag estimated from the RSSI value or the like. For example, the processor 21 may decrease the reference value as the distance to the RFID tag decreases.

[0065] After setting a reference value for the swing amount, the processor 21 determines whether the measured swing amount is less than the set reference value (ACT20). If the swing amount is greater than or equal to the reference value (ACT20, NO), the processor 21 returns to ACT11 and executes the above process again.

[0066] If the swing amount is smaller than the reference value (ACT20, YES), the processor 21 outputs an alert prompting the operator to increase the swing amount (ACT21). For example, as an alert, the processor 21 displays an operation guide on the display unit 114, as shown in the display area 241 of Figure 3. Alternatively, the alert may be an alarm or voice guidance output from a speaker on the information terminal 28. The alert should prompt the operator to change the direction of the antenna 25 to a value greater than the reference value.

[0067] As described above, the wireless tag reader issues an alert prompting the operator to change the antenna's orientation if the swing amount, which indicates the amount of change in the antenna's orientation, is below a certain threshold. This allows the operator of the wireless tag reader to appropriately change the antenna's orientation in order to efficiently search for RFID tags.

[0068] Furthermore, the wireless tag reader sets a reference value for the swing amount, which indicates the amount of change in the antenna's orientation, depending on the situation. If the swing amount is smaller than the reference value set depending on the situation, the wireless tag reader notifies the operator of an alert prompting them to change the antenna's orientation. This allows the wireless tag reader to notify the operator of alerts that enable efficient searching of the target RFID tag, depending on the situation.

[0069] Next, a second example of operation of the wireless tag reader 10 according to the embodiment will be described. Figure 5 is a flowchart illustrating a second example of operation of the wireless tag reader 10 according to this embodiment. The second operational example differs from the first operational example described above in that the swing amount is measured after reading the RFID tag to be searched. Since each process of ACT11-22 shown in Figure 5 is the same as each process of ACT11-22 shown in Figure 4, which was explained in the first operational example, a detailed explanation is omitted.

[0070] The processor 21 of the wireless tag reader 10 performs the RFID tag reading process in response to the operator's instruction to start the search (ACT 11). After obtaining the reading result for each RFID tag within the reading range, the processor 21 determines whether or not the target RFID tag has been read (ACT 13). If the target RFID tag has not been read (ACT 13, NO), the processor 21 returns to ACT 11 and performs the RFID tag reading again.

[0071] If the RFID tag to be searched is read (ACT13, YES), the processor 21 estimates the direction in which the RFID tag to be searched is located (tag direction) (ACT14). After estimating the tag direction, the processor 21 stores the reading result of the RFID tag to be searched, including the estimated tag direction, in the memory 22 (ACT15).

[0072] After saving the reading results of the RFID tag to be searched, the processor 21 determines whether the communication status with the RFID tag to be searched exceeds a reference level (ACT16). If the communication status exceeds a reference level (ACT16, YES), the processor 21 determines whether the output value of the transmission signal set in the communication control circuit 24 is the minimum value that can be set (ACT17).

[0073] If the output value is the minimum value (ACT17, NO), the processor 21 notifies the detection result of the RFID tag being searched (ACT22). If the output value is not the minimum value (ACT17, YES), the processor 21 reduces the output value of the transmission signal set in the communication control circuit 24 (ACT18). If the output value is reduced, or if the communication status is below the reference level (ACT16, NO), the processor 21 measures (detects) the swing amount, which is the change in the orientation of the antenna 25 (ACT31). The processor 21 measures (detects) the swing amount based on the change in orientation (reading direction) detected by the sensor 23, similar to ACT12 described above. However, in the second example of operation, the processor 21 measures the swing amount relative to the estimated tag direction.

[0074] After measuring the swing amount, the processor 21 sets a reference value as a threshold for the swing amount (ACT19). In the second example of operation, the processor 21 sets a reference value for the estimated tag direction. The processor 21 also sets a reference value according to the output value of the transmission signal set in the communication control circuit 24. Furthermore, the processor 21 may also set a reference value taking into account the estimated distance to the RFID tag to be searched.

[0075] When a reference value is set for the swing amount, the processor 21 determines whether the measured swing amount is smaller than the set reference value (ACT20). In the second example of operation, a reference value is set for the tag direction. Therefore, the processor 21 determines whether the swing amount in the tag direction is greater than or equal to the reference value.

[0076] If the swing amount is smaller than the baseline value (ACT20, YES), the processor 21 outputs an alert prompting the user to increase the swing amount in the tag direction (ACT21). If the swing amount is greater than or equal to the standard value (ACT20, NO), processor 21 returns to ACT11 and executes the above process again. According to the second example of operation described above, the wireless tag reader estimates the tag direction in which the RFID tag is located when the RFID tag to be searched is read. The wireless tag reader measures the swing amount, which indicates the amount of change in the antenna orientation relative to the tag direction. If the swing amount is smaller than a reference value relative to the tag direction, the wireless tag reader outputs an alert prompting the reader to increase the swing amount relative to the tag direction.

[0077] As a result, according to the second example of operation, the operator can be prompted to perform an operation such that the amount of swing of the target RFID tag relative to the tag direction exceeds a certain threshold value. Consequently, the wireless tag reader can efficiently search for the target RFID tag based on the operator's actions in response to the alert.

[0078] Next, a third example of operation of the wireless tag reader 10 according to this embodiment will be described. Figure 6 is a flowchart illustrating a third example of operation of the wireless tag reader 10 according to this embodiment. The third example of operation differs from the first example of operation described above in that it starts reading the RFID tag when the swing amount exceeds a certain threshold. Since each process of ACT11-22 shown in Figure 6 is the same as each process of ACT11-22 shown in Figure 4, which was explained in the first example of operation, a detailed explanation is omitted.

[0079] In the third operational example, the processor 21 of the wireless tag reader 10 sets the RFID tag to be searched and then measures the swing amount, which indicates the amount of change in the direction of the antenna (ACT41). After measuring the swing amount, the processor 21 determines whether the measured swing amount is equal to or greater than the reference value for starting the search (search start reference value) (ACT42).

[0080] If the swing amount is smaller than the threshold value for starting the search (ACT42, NO), the processor 21 outputs an alert prompting the user to perform an operation that increases the amount of change in the antenna's orientation (ACT43). For example, the processor 21 displays an operation guide on the display 114 prompting the user to swing the reader device 120 from side to side.

[0081] If the swing amount exceeds the threshold value for starting the search (ACT42, YES), the processor 21 starts the RFID tag reading process and executes the operations of ACT11-22 as described in the first operation example.

[0082] Next, a fourth example of operation of the wireless tag reader 10 according to this embodiment will be described. Figure 7 is a flowchart illustrating a fourth example of operation of the wireless tag reader 10 according to this embodiment. The fourth example differs from the second example described above in that it starts reading the RFID tag when the swing amount exceeds the threshold value for starting the search. The processes of ACT11-22 shown in Figure 6 are the same as the processes of ACT11-22 shown in Figure 5, which were explained in the first and second examples, so a detailed explanation is omitted.

[0083] In the fourth operational example, the processor 21 of the wireless tag reader 10 sets the RFID tag to be searched and then measures the swing amount, which indicates the amount of change in the direction of the antenna (ACT41). After measuring the swing amount, the processor 21 determines whether the measured swing amount is equal to or greater than the reference value for starting the search (search start reference value) (ACT42).

[0084] If the swing amount is smaller than the threshold value for starting the search (ACT42, NO), the processor 21 outputs an alert prompting the user to perform an operation that increases the amount of change in the antenna's orientation (ACT43). For example, the processor 21 displays an operation guide on the display 114 prompting the user to swing the reader device 120 from side to side.

[0085] If the swing amount exceeds the threshold value for starting the search (ACT42, YES), the processor 21 starts the RFID tag reading process and executes the operations of ACT11-22 and 31 as described in the second operation example.

[0086] According to the third and fourth operational examples described above, the wireless tag reader starts reading the RFID tag after confirming that the swing amount exceeds a predetermined threshold value. If the swing amount is less than the threshold for starting the search, the wireless tag reader outputs an alert prompting the user to increase the swing amount, which indicates the change in the antenna's orientation.

[0087] This allows the wireless tag reader to output an alert prompting the user to increase the swing amount while the swing amount is small. Furthermore, the wireless tag reader can begin reading the RFID tag only after the swing amount exceeds a predetermined threshold value. As a result, when the wireless tag reader begins searching for an RFID tag, it can reliably prompt the user to ensure the swing amount is above the threshold value.

[0088] Next, we will describe the process by which the wireless tag reader 10 according to this embodiment estimates the tag direction in which the RFID tag to be searched is located. Figure 8 is a flowchart illustrating a first example of the process by which the wireless tag reader 10 according to this embodiment estimates the tag direction. The processor 21 of the wireless tag reader 10 reads the reading result of the RFID tag to be searched, which is stored in the memory 22 (ACT81). The reading result of the RFID tag stored in the memory 22 includes information indicating the orientation of the RFID tag when it was read. The orientation of the RFID tag to be searched is detected by the sensor 23.

[0089] The processor 21 identifies all possible orientations when reading the RFID tag to be searched (ACT82). The processor 21 calculates the range of all possible orientations when reading the RFID tag to be searched (ACT83). The processor 21 estimates the center of the orientation range as the tag direction (ACT84).

[0090] Figure 9 is a flowchart illustrating a second example of the process by which the wireless tag reader 10 according to the embodiment estimates the tag direction. The processor 21 of the wireless tag reader 10 reads the reading results of the target RFID tag stored in the memory 22 (ACT91). The reading results of the RFID tag stored in the memory 22 include the RSSI value indicating the strength of the received signal when the RFID tag was read. The reading results of the RFID tag stored in the memory 22 include information indicating the orientation of the RFID tag when it was read and the RSSI value indicating the strength of the received signal.

[0091] The processor 21 identifies the reading result that maximizes the RSSI value from the reading results of the RFID tag to be searched (ACT92). Based on the reading result that maximizes the RSSI value, the processor 21 estimates the orientation at which the RSSI value was maximized as the tag direction (ACT84).

[0092] As described above, the wireless tag reader according to the embodiment comprises a communication interface, a sensor, and a processor. The communication interface communicates with the RFID tag via an antenna. The sensor detects a swing amount indicating the amount of change in the antenna's orientation. The processor causes a device such as a display to output an alert prompting the user to increase the swing amount when the swing amount detected by the sensor is smaller than a predetermined reference value. As a result, the wireless tag reader according to the embodiment can prompt the user to perform operations such that the amount of change in the antenna's orientation becomes greater than or equal to the reference value.

[0093] Furthermore, in the wireless tag reader according to the embodiment, the processor estimates the tag direction in which the RFID tag read via the communication interface was located. The processor measures the amount of swing relative to the estimated tag direction when reading the tag information of the RFID tag to be searched. The processor outputs an alert if the amount of swing relative to the tag direction is smaller than a reference value. As a result, the wireless tag reader according to the embodiment can prompt the user to perform operations such that the amount of change in the antenna orientation relative to the direction in which the tag is estimated to be located is greater than or equal to a reference value.

[0094] Furthermore, in the wireless tag reader according to the embodiment, the processor sets a reference value for the swing amount according to the output value of the transmission signal sent to the RFID tag. This allows the wireless tag reader to be prompted to operate with an appropriate swing amount according to the output value of the transmission signal.

[0095] Furthermore, in the wireless tag reader according to the embodiment, the processor estimates the distance to the RFID tag to be searched. The processor can set a reference value for the swing amount according to the distance to the RFID tag. This allows the wireless tag reader to be prompted to operate with an appropriate swing amount according to the estimated distance to the RFID tag to be searched.

[0096] In the embodiments described above, the program executed by the processor was pre-stored in the device's memory. However, the program executed by the processor may be downloaded to the device from a network or installed on the device from a storage medium. The storage medium can be any medium that can store programs and is readable by the device, such as a CD-ROM. Furthermore, functions obtained through pre-installation or download may be implemented in cooperation with the device's internal OS (operating system), etc. Furthermore, in the embodiments described above, the processor 21 was described as performing the search process. However, the processor 111 of the information terminal 28 may send a command to the processor 21, and the processor 111 may take the lead in performing the search process.

[0097] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of symbols]

[0098] 10... Wireless tag reader, 21... Processor, 22... Memory, 23... Sensor, 24... Communication control circuit, 25... Antenna, 26... Communication interface, 27... Interface, 28... Information terminal, 29... Power supply, 111... Processor, 112... Memory, 113... Interface, 114... Display, 115... Input device.

Claims

[Claim 1] A communication control circuit that communicates with a wireless tag via an antenna, A sensor for detecting the amount of change in the direction of the antenna, A processor that outputs an alert when the amount of change in the direction of the antenna detected by the sensor is smaller than a reference value, A wireless tag communication device having a tag.

Images