# US 11,907,795 B2 · Wireless tag communication device and method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,907,795 B2 - Document ID: US11907795B2 - Status: Granted - Kind: B2 - Application number: 17/860,790 - Filed: 2022-07-08 - Published: 2023-03-02 - Granted: 2024-02-20 - Earliest claimed: 2021-08-25 - Assignees: Toshiba Tec Kabushiki Kaisha - Applicants: Toshiba Tec Kabushiki Kaisha - Inventors: Yuki Suzuki - Web page: https://patentgrep.com/patent/US11907795B2 ## CPC - G06K 7/10128: {the step consisting of detection of the presence of one or more record carriers in the vicinity of the interrogation device} - G06K 7/10316: {using at least one antenna particularly designed for interrogating the wireless record carriers (antennas in general H01Q1/22)} - G06K 7/10019: {resolving collision on the communication channels between simultaneously or concurrently interrogated record carriers. (collision between the communication channels used by wireless communication devices, where the solution is not particularly adapted for RFIDs or the like, H04W74/08)} - G06K 7/10118: {the sensing being preceded by at least one preliminary step} - G06K 7/10386: {the interrogation device being of the portable or hand-handheld type, e.g. incorporated in ubiquitous hand-held devices such as PDA or mobile phone, or in the form of a portable dedicated RFID reader} - G06K: GRAPHICAL DATA READING (image or video recognition or understanding G06V); PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS ## Abstract A wireless tag communication device includes an antenna configured to transmit a carrier wave and receive a response wave output from a wireless tag with respect to the carrier wave and to specify a position of the wireless tag to be searched based on a radio wave intensity of the response wave received by the antenna. The device includes: a radio wave controller configured to switch the carrier wave between a first and second carrier wave to be transmitted in a first and second polarization direction respectively; and a comparator configured to compare a first and second radio wave intensity of a first and second response wave respectively output from the wireless tag with respect to the first and second carrier waves respectively, and the radio wave controller switches the carrier wave between the first carrier wave and the second carrier wave based on a comparison result of the comparator. ## Claims ### Claim 1 A wireless tag communication device including an antenna configured to transmit a carrier wave and receive a response wave output from a wireless tag with respect to the carrier wave, and configured to specify a position of the wireless tag to be searched based on a radio wave intensity of the response wave received by the antenna, the wireless tag communication device further comprising: a radio wave controller configured to switch the carrier wave between a first carrier wave to be transmitted in a first polarization direction and a second carrier wave to be transmitted in a second polarization direction; a comparator configured to compare a radio wave intensity of a first response wave output by the wireless tag with respect to the first carrier wave and a radio wave intensity of a second response wave output by the wireless tag with respect to the second carrier wave, the radio wave controller being configured to switch the carrier wave between the first carrier wave and the second carrier wave based on a comparison result of the comparator, the radio wave controller is configured to set an output mode of the carrier wave transmitted from the antenna to a dual polarization mode in which the first carrier wave and the second carrier wave are alternately transmitted or to a single polarization mode in which only one of the first carrier wave and the second carrier wave is transmitted; and a receiver configured to receive identification information that identifies the wireless tag to be searched, wherein the radio wave controller sets the output mode to the single polarization mode when a search for the wireless tag identified by the identification information received by the receiver is started. ### Claim 2 (depends on 1) The device according to claim 1, wherein the comparator is configured to compare, in the dual polarization mode, the radio wave intensity of the first response wave transmitted from the wireless tag with respect to the first carrier wave and the radio wave intensity of the second response wave transmitted from the wireless tag with respect to the second carrier wave transmitted subsequent to the first carrier wave, and as the comparison result of the comparator, when the radio wave intensity of one of the first response wave or the second response wave is continuously higher than that of the other response wave for a preset number of times or more, the radio wave controller switches the output mode to the single polarization mode in which the carrier wave with respect to the response wave having the higher radio wave intensity is continuously transmitted. ### Claim 3 (depends on 1) The device according to claim 1, wherein the radio wave controller is configured to switch the output mode to the dual polarization mode when the antenna does not receive the response wave in the single polarization mode. ### Claim 4 (depends on 1) The device according to claim 1, further comprising: a radio wave information processor configured to estimate a distance between the wireless tag communication device and the wireless tag to be searched and to estimate a direction of the wireless tag to be searched, based on the radio wave intensity of the response wave. ### Claim 5 (depends on 1) The device according to claim 1, further comprising: a display configured to display a positional relationship between the wireless tag communication device and the wireless tag. ### Claim 6 (depends on 5) The device according to claim 5, wherein the display is configured to provide a warning when an earlier radio wave intensity of the radio wave received by the antenna is lower than a subsequent radio wave intensity of the radio wave received by the antenna. ### Claim 7 A wireless tag communication device including an antenna configured to transmit a carrier wave and receive a response wave output from a wireless tag with respect to the carrier wave, and configured to specify a position of the wireless tag to be searched based on a radio wave intensity of the response wave received by the antenna, the wireless tag communication device further comprising: a radio wave controller configured to switch the carrier wave between a first carrier wave to be transmitted in a first polarization direction and a second carrier wave to be transmitted in a second polarization direction; and a comparator configured to compare a radio wave intensity of a first response wave output by the wireless tag with respect to the first carrier wave and a radio wave intensity of a second response wave output by the wireless tag with respect to the second carrier wave, the radio wave controller being configured to switch the carrier wave between the first carrier wave and the second carrier wave based on a comparison result of the comparator, wherein the radio wave controller is configured to control an output value of the carrier wave in a plurality of stages, the radio wave controller decreases the output value of the carrier wave by one stage when the wireless tag communication device receives the response wave from the wireless tag a first preset number of times, and the radio wave controller increases the output value of the carrier wave by one stage when the wireless tag communication device does not receive the response wave from the wireless tag for a second preset number of times. ### Claim 8 (depends on 7) The device according to claim 7, further comprising: a search mode switcher configured to set an operation mode of the wireless tag communication device to a long-distance search mode in which the output value of the carrier wave is variable or to a short-distance search mode in which the output value of the carrier wave is constant. ### Claim 9 A method for controlling a wireless tag communication device by a computer, the wireless tag communication device including an antenna configured to transmit a carrier wave and receive a response wave output from a wireless tag with respect to the carrier wave, and configured to specify a position of the wireless tag to be searched based on a radio wave intensity of the response wave received by the antenna, the method comprising: switching, by a radio wave controller, the carrier wave between a first carrier wave to be transmitted in a first polarization direction and a second carrier wave to be transmitted in a second polarization direction; comparing, by a comparator, a radio wave intensity of a first response wave output by the wireless tag with respect to the first carrier wave and a radio wave intensity of a second response wave output by the wireless tag with respect to the second carrier wave; switching, by the radio wave controller, the carrier wave between the first carrier wave and the second carrier wave based on a comparison result of the comparator; decreasing, by the radio wave controller, an output value of the carrier wave by one stage when the wireless tag communication device receives the response wave from the wireless tag a first preset number of times; and increasing, by the radio wave controller, the output value of the carrier wave by one stage when the wireless tag communication device does not receive the response wave from the wireless tag for a second preset number of times; wherein the radio wave controller is configured to control an output value of the carrier wave in a plurality of stages. ### Claim 10 (depends on 9) The method according to claim 9, further comprising: setting, by the radio wave controller, an output mode of the carrier wave transmitted from the antenna to a dual polarization mode, in which the first carrier wave and the second carrier wave are alternately transmitted, or to a single polarization mode in which only one of the first carrier wave and the second carrier wave is transmitted. ### Claim 11 (depends on 10) The method according to claim 10, further comprising: comparing, by the comparator, in the dual polarization mode, the radio wave intensity of the first response wave transmitted from the wireless tag with respect to the first carrier wave and the radio wave intensity of the second response wave transmitted from the wireless tag with respect to the second carrier wave transmitted subsequent to the first carrier wave; and switching, by the radio wave controller, the output mode to the single polarization mode in which the carrier wave with respect to the response wave having the higher radio wave intensity is continuously transmitted, as the comparison result of the comparator, when the radio wave intensity of one of the first response wave or the second response wave is continuously higher than that of the other response wave for a preset number of times or more. ### Claim 12 (depends on 10) The method according to claim 10, further comprising: switching, by the radio wave controller, the output mode to the dual polarization mode when the antenna does not receive the response wave in the single polarization mode. ### Claim 13 A method for controlling a wireless tag communication device by a computer, the wireless tag communication device including an antenna configured to transmit a carrier wave and receive a response wave output from a wireless tag with respect to the carrier wave, and configured to specify a position of the wireless tag to be searched based on a radio wave intensity of the response wave received by the antenna, the method comprising: switching, by a radio wave controller, the carrier wave between a first carrier wave to be transmitted in a first polarization direction and a second carrier wave to be transmitted in a second polarization direction; comparing, by a comparator, a radio wave intensity of a first response wave output by the wireless tag with respect to the first carrier wave and a radio wave intensity of a second response wave output by the wireless tag with respect to the second carrier wave; and switching, by the radio wave controller, the carrier wave between the first carrier wave and the second carrier wave based on a comparison result of the comparator; setting, by the radio wave controller, an output mode of the carrier wave transmitted from the antenna to a dual polarization mode, in which the first carrier wave and the second carrier wave are alternately transmitted, or to a single polarization mode in which only one of the first carrier wave and the second carrier wave is transmitted; switching, by the radio wave controller, the output mode to the dual polarization mode when the antenna does not receive the response wave in the single polarization mode; receiving, by a receiver, identification information that identifies the wireless tag to be searched; and setting, by the radio wave controller, the output mode to the single polarization mode when a search for the wireless tag identified by the identification information received by the receiver is started. ### Claim 14 (depends on 9) The method according to claim 9, further comprising: estimating by a radio wave information processor, a distance between the wireless tag communication device and the wireless tag to be searched and a direction of the wireless tag to be searched, based on the radio wave intensity of the response wave. ### Claim 15 (depends on 9) The method according to claim 9, further comprising: setting, by a search mode switcher, an operation mode of the wireless tag communication device to a long-distance search mode in which the output value of the carrier wave is variable or to a short-distance search mode in which the output value of the carrier wave is constant. ### Claim 16 (depends on 9) The method according to claim 9, further comprising: displaying, by a display, a positional relationship between the wireless tag communication device and the wireless tag. ### Claim 17 (depends on 16) The method according to claim 16, further comprising: providing, by the display, a warning when an earlier radio wave intensity of the radio wave received by the antenna is lower than a subsequent radio wave intensity of the radio wave received by the antenna.