JP5245926B2 - Wireless tag and wireless tag communication system - Google Patents

Description

  The present invention relates to a wireless tag that performs wireless communication with a wireless tag communication device and a wireless tag communication system, and in particular, a wireless tag and a wireless tag communication that include a light emitting unit capable of emitting light when wireless communication is performed with the wireless tag communication device. About the system.

  Conventionally, an RFID (Radio Frequency Identification) tag in which an identification number of the article is recorded is attached to the article to be managed. The manager or user of the article manages the article by causing the RFID reader to read the identification information of the article from the RFID tag.

  In recent years, a management system that causes a light emitting unit such as a light emitting element provided in an RFID tag to emit light by wireless communication with an RFID reader has been proposed (Patent Document 1). When the RFID tag in this prior art performs wireless communication with the RFID reader, the content of light emission is changed according to information about the article such as the elapsed time from the production date and time of the article to which the RFID tag is attached.

JP 2002-60017 A

  Wireless communication between the RFID reader and the RFID tag is performed under various communication conditions. In particular, the search for an article to which an RFID tag is attached is performed in a state where the distance between the RFID reader and the RFID tag is some distance away. That is, the user searches for the RFID tag by operating the RFID reader from a position somewhat away from the article to which the RFID tag is attached.

  Then, the user finds an article to which the RFID tag searched by the RFID reader is attached. In the prior art described in Patent Document 1 described above, the user finds an article by confirming light emission or the like of the display portion of the RFID tag from a position somewhat away from the RFID tag.

  However, in the prior art, the light emission mode of the light emitting unit is not adjusted according to the distance between the RFID reader and the RFID tag. Therefore, the user must confirm the article by the same light emission mode regardless of whether the distance between the RFID reader (specifically, the user who operates the RFID reader) and the RFID tag is a long distance or a short distance. did not become.

  Specifically, for example, in the conventional technology, when the light emission of the light emitting unit is strong (a conspicuous light emission pattern) at both a long distance and a short distance, it is difficult to confirm the RFID tag from a short distance. That is, when a plurality of RFID tags emit light strongly at a short distance, overlapping of light emission or flickering occurs, and it is difficult to determine which RFID tag emits light. Moreover, when the light emission of the light emitting unit is weakened, a problem that it is difficult to confirm the RFID tag from a long distance is an example.

  In order to solve the above-described problem, the present invention can change the light emission mode of the light emitting portion of the wireless tag according to the state of wireless communication with the wireless tag communication device, and can perform efficient light emission. It is another object of the present invention to provide a wireless tag communication system. In particular, to provide a wireless tag and a wireless tag communication system capable of improving the efficiency of light emission by appropriately determining the light emission mode of the light emitting unit according to the distance between the wireless tag communication device and the wireless tag. Objective.

In order to solve the above-described problems and achieve the object, the wireless tag according to the invention of claim 1 is a wireless tag including a light emitting unit capable of emitting light when wireless communication is performed with a wireless tag communication device, the wireless tag against the interrogating wave transmitted from the communication device, wherein acquires the response time information about the response time of the wireless tag communication apparatus in a radio communication from the radio tag communication apparatus, the light emission based on the response time information The light emission control means which controls the light emission mode of a part is provided.

Wireless tag according to the invention of claim 2 is the invention according to claim 1, wherein the radio when the tag communication apparatus and wireless communication is performed, the possible switching power supply of the internal power supply to the wireless tag power Control means is further provided.

According to a third aspect of the present invention, there is provided a wireless tag communication system comprising: a wireless tag communication device; and a wireless tag including a light emitting unit capable of emitting light when wireless communication is performed with the wireless tag communication device. In the system, the wireless tag communication device measures a response time until the response wave is received from the wireless tag in response to the interrogation wave when the interrogation wave is transmitted to the radio tag. And the wireless tag includes light emission control means for controlling a light emission mode of the light emitting unit based on the response time measured by the time measuring means.

A wireless tag communication system according to a fourth aspect of the present invention is the wireless tag communication system according to the third aspect , wherein the wireless tag communication device further comprises response time transmitting means for transmitting the response time measured by the time measuring means. The light emission control means of the wireless tag determines a current value for controlling a light emission mode of the light emitting unit from the response time transmitted by the response time transmission means, and the light emission based on the determined current value The light emission mode of the part is controlled.

A wireless tag communication system according to a fifth aspect of the present invention is the wireless tag communication system according to the third aspect , wherein the wireless tag communication device changes the light emission mode of the wireless tag based on the response time measured by the time measuring means. The wireless tag light emission control means further comprises: a determination means for determining a current value to be controlled; and a light emission instruction signal transmission means for transmitting a light emission instruction signal based on the current value determined by the determination means to the wireless tag. The light emission mode of the light emitting unit is controlled based on the light emission instruction signal transmitted by the light emission instruction signal transmission means.

According to the first aspect of the present invention, light emission efficiency can be improved by controlling the light emission of the light emitting unit in the light emission mode according to the response time information in the wireless communication with the wireless tag communication device.

According to the second aspect of the present invention, it is possible to switch to the internal power supply when wireless communication is performed with the wireless tag communication device, so that it is possible to stabilize power supply to the wireless tag.

According to the third aspect of the present invention, light emission efficiency can be improved by controlling the light emission of the light emitting unit in the light emission mode according to the response time measured by the wireless tag communication device.

According to the fourth aspect of the invention, the light emission mode of the wireless tag can be controlled by transmitting the response time measured by the wireless tag communication device to the wireless tag. Therefore, simplification of the configuration and processing of the RFID tag communication apparatus can be achieved.

According to the fifth aspect of the present invention, the light emission mode of the wireless tag can be controlled by the light emission current value determined by the wireless tag communication device. Therefore, the configuration of the wireless tag can be simplified and the processing can be simplified.

  As described above, according to the wireless tag and the wireless tag communication system according to the present invention, the light emission mode of the light emitting unit of the wireless tag can be changed according to the state of the wireless communication with the wireless tag communication device, which is efficient. This produces the effect of being able to emit light.

It is explanatory drawing which shows an example of the file search system concerning Embodiment 1 of this invention. It is explanatory drawing which shows an example of the functional structure of the reader in the file search system concerning Embodiment 1 of this invention. It is explanatory drawing which shows an example of a functional structure of the wireless tag in the file search system concerning Embodiment 1 of this invention. It is explanatory drawing shown about the light emission characteristic of LED which is an example of the light emission part concerning Embodiment 1 of this invention. It is explanatory drawing shown about the issuing characteristic of organic EL which is an example of the light emission part concerning Embodiment 1 of this invention. It is a flowchart which shows the content of the process of the reader | leader concerning 1st Embodiment of this invention, and a wireless tag. It is explanatory drawing which shows an example of the determination of the light emission current value concerning Embodiment 1 of this invention. It is explanatory drawing which shows an example of the determination of the luminous intensity concerning the modification of Embodiment 1 of this invention. It is explanatory drawing which shows an example of the determination of the light emission current value concerning the modification of Embodiment 1 of this invention. It is a flowchart which shows the content of the process of the reader | leader concerning Embodiment 2 of this invention, and a wireless tag. It is explanatory drawing which shows an example of the determination of the light emission current value concerning Embodiment 2 of this invention. It is explanatory drawing which shows an example of the determination of the luminous intensity concerning the modification of Embodiment 2 of this invention. It is explanatory drawing which shows an example of a functional structure of the wireless tag in the file search system concerning Embodiment 3 of this invention. It is a flowchart which shows the content of the process of the reader | leader concerning Embodiment 3 of this invention, and a wireless tag. It is a flowchart which shows the content of the process of the reader | leader concerning 4th Embodiment of this invention, and a wireless tag.

  Exemplary embodiments of a wireless tag and a wireless tag communication system according to the present invention are explained in detail below with reference to the accompanying drawings.

(Embodiment 1)
(Overview of file search system)
A file search system according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is an explanatory diagram illustrating an example of a file search system according to the first embodiment of the present invention. FIGS. 1A and 1B show the case where the communication distance between the wireless tag T and the reader 110 is (communication distance in FIG. 1A) <(communication distance in FIG. 1B). Show.

  In the first embodiment, each file 101 is affixed to each of a plurality of files 101 (in the example shown, the codes 101a, 101b, 101c, 101d, and 101e are simply referred to as “file 101” unless otherwise specified). The wireless tag according to the present invention is realized by the wireless tag T (in the example shown, the codes are Ta, Tb, Tc, Td, Te and are simply referred to as “wireless tag T” unless otherwise specified). A case where the wireless tag communication system according to the present invention is realized by a file search system including the wireless tag T and the reader 110 will be described.

  When searching for the file 101c from the plurality of files 101, the user transmits a search command to the wireless tag Tc attached to the file 101c by the handy type reader 110. Specifically, the reader 110 specifies a tag ID as tag identification information of the wireless tag Tc as a search command, and confirms the presence or absence of the wireless tag Tc storing the specified tag ID. Send the signal.

  More specifically, for example, the reader 110 stores a correspondence table between each file 101 and the tag ID in a memory (not shown), and when the user inputs a file name, the reader 110 stores the file 101 corresponding to the file name. A search command specifying a tag ID is transmitted.

  When the wireless tag T receives the search command transmitted from the reader 110, the wireless tag T determines whether or not the tag ID stored in the wireless tag T matches the tag ID specified by the search command. When the stored tag ID matches the tag ID specified by the search command, the wireless tag Tc transmits a response command to the reader 110. Specifically, for example, the wireless tag Tc transmits a signal including various information such as a tag ID stored in the wireless tag Tc as a response command.

  When the reader 110 receives the response command from the wireless tag Tc, the reader 110 transmits a light emission command for causing the wireless tag Tc to emit light from the wireless tag Tc based on the communication status with the wireless tag Tc. Specifically, the reader 110 transmits a search command to the wireless tag Tc and receives a response time t (described later in FIG. 7) from receiving the response command from the wireless tag Tc. Based on V (described later in FIG. 11), a light emission current value I that indicates a light emission intensity or a light emission pattern for causing the wireless tag Tc to emit light is determined. The reader 110 transmits a signal for causing the light emitting unit to emit light based on the determined light emission current value I as a light emission command.

  For example, when the response time t is short or the reception intensity V is large, the light emission command indicates that the communication distance is short (in other words, the positional relationship between the user and the file 101 is close) and the light emission current value I is set. decide. In other words, the light emission command is a command that is dimmed enough to allow the user to confirm the light emission of the wireless tag Tc at a short distance, or to increase the blinking interval.

  In addition, when the response time t is long or the reception intensity V is small, the light emission command indicates that the communication distance is long (in other words, the positional relationship between the user and the file 101 is long) and the light emission current value I is set. decide. That is, the light emission command is a command that is bright enough to allow the user to confirm the light emission of the wireless tag Tc at a long distance, or to shorten the blinking interval.

  When receiving the light emission command from the reader 110, the wireless tag Tc causes the light emitting unit to emit light based on the light emission current value I instructed by the light emission command. Then, the user can find the wireless tag Tc (specifically, the file 101c with the wireless tag Tc attached) by confirming the light emission of the light emitting unit of the wireless tag Tc.

(Functional configuration)
A functional configuration of the reader 110 in the file search system 100 will be described with reference to FIG. FIG. 2 is an explanatory diagram illustrating an example of a functional configuration of a reader in the file search system according to the first embodiment of the present invention.

  2, the reader 110 of the file search system 100 includes a control unit 211 that controls the entire reader 110, a reader antenna AT that performs wireless communication with the wireless tag T attached to the file 101, and a reader antenna AT. A wireless tag communication control unit 212 that controls wireless communication with the wireless tag T, an operation unit 213 that receives input of various information and outputs the information to the control unit 211, a display unit 214 that displays display data, and an external device A communication I / F 215 that controls communication with the wireless tag T, and a timer 216 that measures a response time t in wireless communication with the wireless tag T. Each component of the reader 110 is connected by a bus 210.

  The control unit 211 controls the entire reader 110. Specifically, the control unit 211 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc. The ROM records various programs such as a boot program. Yes. The RAM is used as a work area for the CPU.

  The wireless tag communication control unit 212 performs wireless communication with the wireless tag T via the reader antenna AT according to the control of the control unit 211. Specifically, the control unit 211 designates the tag ID of the wireless tag Tc attached to the search target file 101c. The tag ID is specified based on, for example, a correspondence table between file names stored in a memory (not shown) and tag IDs.

  Specifically, when a search target file name is input from the user by the operation unit 213, the control unit 211 specifies the tag ID of the wireless tag Tc corresponding to the file name from the correspondence table. Then, the control unit 211 controls the wireless tag communication control unit 212 to transmit a search command for searching for the wireless tag Tc (file 101c to which the wireless tag Tc is attached) designated by the tag ID via the reader antenna AT. Send.

  The correspondence table is stored in a memory (not shown) provided in the reader 110, but may be stored in a server (not shown). That is, when a user inputs a search target file name to the server, the tag ID is specified by the server. Then, the reader 110 receives input of a tag ID from the server via the communication I / F 215.

  The control unit 211 controls the wireless tag communication control unit 212 to receive a response command transmitted from the wireless tag Tc via the reader antenna AT. The control unit 211 controls the wireless tag communication control unit 212 to transmit a light emission command based on the response command received from the wireless tag Tc via the reader antenna AT.

  Specifically, the control unit 211 realizes the function of the determination unit according to the present invention, and according to the response time t counted by the timer 216 from when the search command is transmitted until the response command is received, the light emitting unit A light emission current value I for emitting light is determined. The control unit 211 emits a light emission command as a light emission instruction signal including the tag ID of the wireless tag Tc to be emitted (in other words, the wireless tag Tc attached to the search target file 101c) and the determined light emission current value I. Is controlled by the wireless tag communication control unit 212, and a light emission command is transmitted to the wireless tag Tc via the reader antenna AT.

  That is, the control unit 211 controls the wireless tag communication control unit 212 to realize the function of the light emission instruction signal transmission unit according to the present invention. Although details will be described with reference to FIGS. 10 and 11, the control unit 211 determines the light emission current value I according to the reception intensity V detected according to the output from the RFID tag communication control unit 212 for the response command. It is good also as a structure which determines.

  The operation unit 213 receives input of various information from a user or the like. Specifically, the operation unit 213 is configured by a touch panel, operation buttons, and the like, and receives input such as information related to the search of the file 101 and outputs the input signal to the control unit 211.

  The display unit 214 displays various information according to the control of the control unit 211. Specifically, the display unit 214 is configured by a CRT, a TFT liquid crystal display, a plasma display, or the like, and displays a screen related to search or the like by a document or an image. The screen related to the search is, for example, an initial screen for selecting processing of the reader 110, a reading screen indicating that the wireless tag T is being read, a confirmation screen for various information, and the like.

  The communication I / F 215 is connected to a network such as the Internet through a communication line, and is connected to another external device such as a server (not shown) via this network. The communication I / F 215 controls an interface between the network and the reader 110, and controls data input / output with respect to an external device. As the communication I / F 215, for example, a modem or a LAN adapter can be employed.

  The timer 216 measures various times according to the control of the control unit 211. Specifically, the timer 216 realizes the function of the time measuring unit according to the present invention, and measures the response time t from when the search command is transmitted to the wireless tag T until the response command is received from the wireless tag T. .

  In the first embodiment, the response time t is constant regardless of the distance from the reader 110 to the wireless tag T with respect to the time for processing the search command by the wireless tag T. That is, the response time t represents the distance from the reader 110 to the wireless tag T without considering the time for processing the search command by the wireless tag T.

  Next, a functional configuration of the wireless tag T in the file search system 100 will be described with reference to FIG. FIG. 3 is an explanatory diagram illustrating an example of a functional configuration of the wireless tag in the file search system according to the first embodiment of the present invention.

  In FIG. 3, the wireless tag T includes a tag antenna 301 that performs wireless communication with the reader antenna AT, and an IC circuit unit 350 connected to the tag antenna. The IC circuit unit 350 includes a rectifier 302 that rectifies an interrogation wave such as a search command received by the tag antenna 301, and an interfering wave energy rectified by the rectifier 302 and an internal battery 308 that is switched by the control unit 307. A power supply unit 303 for storing energy to be used as a driving power source, a clock extraction unit 304 that extracts a clock signal from the interrogation wave received by the tag antenna 301 and supplies the clock signal to the control unit 307, and a predetermined tag ID such as its own tag ID A memory unit 305 capable of storing an information signal, a modem unit 306 connected to the tag antenna 301, a light emitting unit 309 that emits light in response to a light emission command received from the reader 110 received by the tag antenna 301, a power source unit 303, a clock Extraction unit 304, memory unit 305, modem unit 306, internal battery 308, and light emission A control unit 307 for controlling the operation of the RFID tag T via a 309, and a.

  The power supply unit 303 stores energy according to the control of the control unit 307 and uses it as a driving power source for the wireless tag T. The energy supply source of the driving power stored in the power supply unit 303 is controlled by the control unit 307 to either the rectifying unit 302 or the internal battery 308. Although the wiring is omitted for simplicity of the drawing, the power supply unit 303 is connected to each component of the wireless tag T and supplies drive power to each component under the control of the control unit 307.

  The clock extraction unit 304 extracts a clock component from the received signal and supplies a clock corresponding to the frequency of the clock component of the received signal to the control unit 307. The modem unit 306 demodulates the interrogation wave from the reader antenna AT of the reader 110 received by the tag antenna 301. The modem unit 306 modulates the reply signal from the control unit 307 and transmits it as a response wave (a signal including a tag ID) such as a response command from the tag antenna 301.

  The control unit 307 interprets the received signal demodulated by the modem unit 306. Specifically, for example, the control unit 307 interprets a search command or a light emission command transmitted from the reader 110 demodulated by the modem unit 306.

  The control unit 307 generates a reply signal based on the information signal stored in the memory unit 305 according to the received signal. Specifically, for example, the control unit 307 generates a response command as a reply signal when the tag ID in the search command transmitted from the reader 110 is its own tag ID. The control unit 307 modulates the generated response command by the modem unit 306 and sends it back from the tag antenna 301.

  The internal battery 308 supplies energy to the inside of the wireless tag T via the power supply unit 303 under the control of the control unit 307. Specifically, the control unit 307 realizes the function of the power control unit according to the present invention, and operates the wireless tag T when receiving a query wave such as a search command or a light emission command from the reader 110 via the tag antenna 301. The energy supply source (energy supply source of the drive power supply) is switched to the internal battery 308.

  The light emitting unit 309 includes a light emitting element such as an LED (Light Emitting Diode) or an organic EL (Electro Luminescence), and emits light according to the control of the control unit 307. Specifically, the control unit 307 realizes the function of the light emission control unit according to the present invention, and outputs the light emission current value I based on the light emission intensity and the light emission pattern instructed by the light emission command transmitted from the reader 110. The light is supplied from 303 to the light emitting unit 309.

  Here, the light emission characteristics of the light emitting unit 309 will be described with reference to FIGS. 4 and 5. FIG. 4 is an explanatory diagram showing light emission characteristics of an LED that is an example of the light emitting unit according to the first embodiment of the present invention. In FIG. 4, a characteristic diagram 400 showing the light emission characteristics of an LED is a light emission current value I (mA: milliampere) for causing the LED to emit light, and the brightness of light per unit solid angle emitted from the light source (light emission intensity). The relationship with the luminous intensity (mcd: millicandela), which is a psychological physical quantity representing).

  A characteristic diagram 400 shows a characteristic in which the luminous intensity increases as the light emission current value I increases. That is, since the light emission current value I and the light intensity have a proportional relationship, a high light emission current value I is required to increase the light intensity.

FIG. 5 is an explanatory diagram showing issuance characteristics of an organic EL that is an example of the light emitting unit according to the first embodiment of the present invention. In FIG. 5, a characteristic diagram 500 showing the light emission characteristics of the organic EL is a light emission current value I (mA) for causing the organic EL to emit light and a luminance (mcd /) indicating the luminous intensity of light emitted from the light source per unit area. m ² ).

  A characteristic diagram 500 shows a characteristic that the luminance increases as the light emission current value I increases. That is, since the light emission current value I and the luminance have a proportional relationship, a high light emission current value I is required to increase the luminance.

(Contents of file search system processing)
The processing contents of the file search system 100 according to the first embodiment of the present invention will be described with reference to FIGS. 6 and 7. FIG. 6 is a flowchart showing the processing contents of the reader and the wireless tag according to the first embodiment of the present invention. The processing contents of the reader according to the first embodiment of the present invention will be described with reference to the flowchart of FIG. 6A, and the processing contents of the wireless tag according to the first embodiment of the present invention will be described with reference to the flowchart of FIG. explain.

  In the flowchart of FIG. 6A, first, the control unit 211 accepts designation of a search target tag (step S600). The search target tag is designated by, for example, operating the operation unit 213 of the reader 110 and inputting the search target file name in order for the user to search for the file 101.

  The control unit 211 controls the wireless tag communication control unit 212 based on the information input by the operation unit 213 to search for the wireless tag T attached to the search target file 101 via the reader antenna AT. A command is transmitted (step S601), the timer 216 is controlled, and the response time t is counted (step S602).

  When the control unit 211 of the reader 110 starts counting the response time t in step S602, it determines whether or not a command is received from the wireless tag T by the reader antenna AT (step S606). That is, the control unit 211 waits for reception of a response command transmitted from the wireless tag T in response to the search command transmitted in step S601, and if received (step S606: Yes), in step S602. The counting of the started response time t is ended (step S607).

  Although detailed explanation is omitted, in step S606, when waiting for reception of the response command from the wireless tag T, if the response command cannot be received even after waiting for a predetermined time, the processing of the reader 110 is terminated as it is as a timeout. Alternatively, the search command may be transmitted again after returning to step S601.

  The control unit 211 determines a light emission current value I for causing the light emitting unit 309 of the wireless tag T to emit light based on the response time t counted in step S602 and step S607 (step S608). Specifically, when the response time t is long, the control unit 211 sets the light emission current value I so that the light emission intensity (luminous intensity) becomes strong because the wireless tag T exists at a position far from the reader 110. When the response time t is short, the light emission current value I is determined so that the light emission intensity is weakened because the wireless tag T is located near the reader 110.

  Here, the determination of the light emission current value I according to the first embodiment of the present invention will be described with reference to FIG. FIG. 7 is an explanatory diagram showing an example of determination of the light emission current value according to the first embodiment of the present invention. In FIG. 7, data 700 for determining the light emission current value I is stored in a ROM or memory (not shown) in the control unit 211. The response time t between the reader 110 and the wireless tag T, the light emission current value I, and the like. Shows the relationship.

  The response time t changes according to the communication distance between the wireless tag T and the reader 110. That is, if the light speed c (m / sec), which is the speed of radio waves such as a search command and a response command, and the communication distance d between the wireless tag T and the reader 110, the response time t is a round trip between the wireless tag T and the reader 110. Therefore, the relational expression 2d = c × t is established. The maximum response time tmax may indicate the response time t when the wireless tag T is located at the boundary of the communicable range of the reader 110, for example.

  The light emission current value I is determined according to a desired light emission intensity for the light emitting unit 309. That is, as shown in FIG. 7, the light emission current value I decreases as the communication distance between the wireless tag T and the reader 110 is shorter and the response time t is shorter, and the communication distance between the wireless tag T and the reader 110 is longer. The longer t is, the higher it is determined. In addition, the light emission current value I is determined in the range from the minimum rated current value Imin, which is a current value rated according to the type of the light emitting unit 309, to the maximum rated current value Imax.

  Although the determination data 700 has been described as being stored in the ROM or memory as the initial setting of the reader 110, it may be generated according to the output of the reader 110 or the type of the light emitting unit 309.

  Returning to FIG. 6A, the control unit 211 controls the wireless tag communication control unit 212 based on the light emission current value I determined in step S608, and sends a light emission command to the wireless tag T via the reader antenna AT. Is transmitted (step S609), and it is determined whether the search is completed (step S610). The search is completed, for example, an input indicating that the file 101 with the RFID tag T to be searched is found or an input indicating that the search is stopped by the operation of the operation unit 213 by the user. It is good also as a structure which receives the input of the signal which shows this.

  In step S610, when the search is finished (step S610: Yes), a series of processing of the reader 110 is finished as it is. If the search is not completed (step S610: No), the process returns to step S601 and the process is repeated.

  In the flowchart of FIG. 6B, first, the control unit 307 determines whether or not the tag antenna 301 has received a command from the reader 110 (step S603). That is, the control unit 307 waits for reception of the search command transmitted from the reader 110 in step S601, and if received (step S603: Yes), performs response processing (step S604).

  In the response process, for example, the rectification unit 302 rectifies the search command transmitted from the reader 110. The power source unit 303 accumulates the rectified energy and uses it as a drive power source, and the modem unit 306 demodulates the search command. Then, the control unit 307 determines whether or not the tag ID in the demodulated search command matches its own tag ID.

  The control unit 307 generates a response command for the reader 110 and transmits the generated response command via the tag antenna 301 when the tag ID matches the tag ID of the search command by the response processing in step S604. (Step S605). Although a detailed description is omitted, if the tag ID in the search command does not match the tag ID of the search command, it is not a search target, and the processing may be terminated as it is.

  When the response command is transmitted in step S605, the control unit 307 determines whether the tag antenna 301 has received a command from the reader 110 (step S611). That is, the control unit 307 waits for reception of the light emission command transmitted from the reader 110 in step S609, and when it receives (step S611: Yes), performs response processing (step S612).

  When performing the response process of the light emission command in step S612, the control unit 307 switches the energy supply source for operating the wireless tag T to the internal battery 308 (step S613). Thus, energy can be stably supplied with respect to the light emission of the light emitting unit 309 by setting the energy supply source to the internal battery 308 before the light emitting unit 309 described later emits light.

  Based on the light emission command received in step S611, the control unit 307 issues a light emission command based on the light emission current value I to the light emission unit 309 (step S614), and ends a series of processing of the wireless tag T. Specifically, for example, when the wireless tag T causes the light emitting unit 309 to emit light in response to the light emission command, the light emission is continued without receiving a new search command for a certain time, and the light emission is stopped after a certain time has elapsed and a new light is emitted. A search command is awaited (for example, the state in step S603).

  The processing in each component of the present invention will be described in association with each processing or function in the first embodiment of the present invention. The processing of the light emission control unit according to the present invention is performed by the processing of the control unit 307 in step S614. Is executed. The processing of the power control unit according to the present invention is executed by the processing of the control unit 307 in step S613. By the processing of the control unit 211 and the timer 216 in step S602 and step S607, the processing of the time measuring unit according to the present invention is executed. The process of the determination unit according to the present invention is executed by the process of the control unit 211 in step S608. By the processing of the control unit 211 and the wireless tag communication control unit 212 in step S609, the processing of the light emission signal transmission unit according to the present invention is executed.

  As described above, according to the wireless tag and file search system according to the first embodiment of the present invention, the light emitting unit is caused to emit light in the light emission mode determined according to the response time in the wireless communication between the wireless tag and the reader. be able to. In other words, the wireless tag located at a long distance from the reader has a light emitting mode that is easy for the user to check even from a long distance, and the wireless tag located at a short distance from the reader is sufficient for the user to check at a short distance. It can be set as a light emission mode. Therefore, efficient light emission can be achieved while enabling an appropriate file search.

  In addition, since the wireless tag can be switched to the internal battery before causing the light emitting unit to emit light, the light emitting unit can be caused to emit light stably, and the ease of file search can be improved.

(Other variations)
In the first embodiment of the present invention, in particular, the description has been given of switching the energy supply source in step S612 shown in FIG. 6, but any stage after wireless communication with the reader 110 in step S604 is performed. It is good also as switching by. If the configuration is switched to the internal battery 308 at an early stage, the RFID tag T can be stably operated. If the configuration is switched to the internal battery 308 at a later stage (immediately before light emission), the energy consumption of the internal battery 308 can be reduced. Can be suppressed. Such timing for switching to the internal battery 308 may be appropriately set based on the remaining amount of the internal battery 308 or the like.

  Further, in steps S602 and S607 shown in FIG. 6, the time from when the search command is transmitted by the reader 110 to when the response command from the wireless tag T is received is counted as the response time. However, it is not limited to this. Specifically, the time required for response processing in the wireless tag T may be considered.

  For example, a predetermined time may be set as the time required for the response processing, or the wireless tag T may be provided with a timer, and an actually measured value may be included in the response command and transmitted to the reader 110. That is, by setting the response time as (time from when the search command is transmitted by the reader 110 to when the response command from the wireless tag T is received) − (time required for response processing), more accurate response Time can be adopted.

  Moreover, although it demonstrated as determining the light emission current value I for making the light emission part 309 light-emit in step S608 shown in FIG. 6, it does not restrict to this. Specifically, for example, a blinking interval that is a light emission pattern may be determined. That is, if the communication distance between the reader 110 and the wireless tag T is long, the blinking interval may be determined to be short for the user to confirm even from a long distance, and if the communication distance is short, the blinking interval may be determined to be long.

  Further, if the light emitting unit 309 is configured to emit light of a plurality of colors, the light emission color may be determined. For example, if the communication distance between the reader 110 and the wireless tag T is long, the light emission color is determined to be a conspicuous color (for example, a color that can be confirmed from a distance such as red), and if it is a short distance, an inconspicuous color (for example, It may be determined to be an eye-friendly color such as green. Of course, in step S608, it is only necessary to determine at least one of the light emission current value I, the light emission pattern, and the light emission color, and the versatility of the file search system 100 can be improved.

  In addition, although it has been described that the light emission current value I for causing the light emitting unit 309 to emit light is determined by the reader 110 in step S608 illustrated in FIG. 6, the present invention is not limited thereto. That is, the light emission current value I may be determined by the wireless tag T without determining the light emission current value I by the reader 110.

  Specifically, in step S602 to step S607, when the response time t is measured by the timer 216 of the reader 110, the control unit 211 controls the wireless tag communication control unit 212 without determining the light emission current value I. The response time is transmitted to the wireless tag T. That is, the function of the response time transmission unit according to the present invention is realized by the control unit 211 and the wireless tag communication control unit 212.

  In this case, the wireless tag T stores the determination data 700 in the ROM or the memory unit 305 of the control unit 307, and determines the light emission current value I based on the response time transmitted from the reader 110.

  Further, in step S608, to simplify the configuration, even if the characteristics of the light emitting elements such as LEDs and organic EL are not stored, the response time t and the light emission current value I are directly proportional to each other within a predetermined range. However, the light emission current value I may be determined after determining the luminous intensity and the luminance. That is, the light intensity and the luminance are determined by the control unit 211 of the reader 110 according to the response time t. The reader 110 determines the light emission current value I from the light emission characteristics of the light emitting unit 309 according to the determined light intensity and luminance.

  Here, the light emission mode of the light emitting unit 309 when the light intensity is determined by the reader 110 according to the modification of the first embodiment of the present invention will be described with reference to FIGS. 8 and 9. In the description of FIGS. 8 and 9, a case will be described in which an LED is used as the light emitting unit 309 and the luminous intensity is determined according to the response time t in step S608 shown in FIG.

  FIG. 8 is an explanatory diagram illustrating an example of determining the luminous intensity according to the modification of the first embodiment of the present invention. In FIG. 8, the luminous intensity determination table 800 is stored in a ROM or memory (not shown) in the control unit 211, and constitutes the response time t between the reader 110 and the wireless tag T and the light emitting unit 309 of the wireless tag T. The relationship with the luminous intensity of LED is shown.

  Specifically, the luminous intensity is high when the communication time between the reader 110 and the wireless tag T is long, and is low when the distance is short, and the luminous intensity is high when the response time t is long, and the response time t is short. In other words, the light intensities L1, L2, and L3 (L1 <L2 <L3) are determined for the response times t1, t2, and t3 (t1 <t2 <t3), respectively. More specifically, for example, the relationship between the response time t and the luminous intensity may be a directly proportional relationship such that when the communication distance is doubled, the luminous intensity is also doubled.

  FIG. 9 is an explanatory diagram illustrating an example of determination of the light emission current value according to the modification of the first embodiment of the present invention. In FIG. 9, the determination data 900 for determining the light emission current value I from the light intensity is stored in a ROM or a memory (not shown) in the control unit 211, and the LED relationship between the light intensity and the light emission current value I is stored. The light emission characteristics are shown.

  In the determination data 900, the light emission current values I1, I2, and I3 can be determined according to the light intensity L1, L2, and L3 determined by the control unit 211 based on the light intensity determination table 800, respectively. As shown in FIGS. 8 and 9, if the desired luminous intensity is determined from the response time t and the luminous current value I is determined, the luminous current value I in which the communication distance and luminous intensity have a direct proportional relationship. Can be determined.

  8 and 9, the light emission current value I may be determined by the wireless tag T without determining the light emission current value I by the reader 110. That is, the light intensity is determined by the control unit 211 of the reader 110 according to the response time t. The reader 110 transmits a light emission command to the wireless tag T based on the determined light intensity.

  The control unit 307 of the wireless tag T sets the light emission current value I that is the light intensity in the received light emission command from the light emission characteristics of the light emission unit 309 stored in a ROM or memory (not shown), and causes the light emission unit 309 to emit light. . Alternatively, if the light intensity determination table 800 and the determination data 900 are stored in the ROM or memory of the wireless tag T, the light intensity and the light emission current value I can be determined by the wireless tag T. In this way, the configuration of the reader 110 can be simplified.

  8 and 9, the case where the organic EL is used as the light emitting unit 309 and the luminance is determined according to the response time t is substantially the same as the relationship between the LED and the luminous intensity. Is omitted.

(Embodiment 2)
Next, Embodiment 2 of the present invention will be described. Embodiment 2 of the present invention describes a case where the light emission current value is determined according to the reception intensity of the response command from the wireless tag in the reader and file search system described in Embodiment 1. Note that the outline of the file search system according to the second embodiment, the functional configuration of the reader, the functional configuration of the wireless tag, and the light emission characteristics of the light emitting unit are substantially the same as those of the first embodiment, and thus description thereof is omitted.

(Contents of file search system processing)
The processing contents of the file search system 100 according to the second embodiment of the present invention will be described with reference to FIGS. 10 and 11. FIG. 10 is a flowchart showing the processing contents of the reader and the wireless tag according to the second embodiment of the present invention. The processing contents of the reader according to the second embodiment of the present invention will be described with reference to the flowchart of FIG. 10A, and the processing contents of the wireless tag according to the second embodiment of the present invention will be described with reference to the flowchart of FIG. explain.

  In the flowchart of FIG. 10A, first, the control unit 211 accepts designation of a search target tag (step S1000). The search target tag is designated by, for example, operating the operation unit 213 of the reader 110 and inputting the search target file name in order for the user to search for the file 101.

  The control unit 211 controls the wireless tag communication control unit 212 based on the information input by the operation unit 213 to search for the wireless tag T attached to the search target file 101 via the reader antenna AT. A command is transmitted (step S1001).

  In response to the search command transmitted in step S1001, the control unit 211 waits for the response command transmitted from the wireless tag T to be received by the reader antenna AT, and receives the response command (step S1005: Yes). The received strength V of the response command is detected (step S1006). The reception strength V is detected by, for example, reception signal strength detection (RSSI: Receive Signal Strength Indication) corresponding to the output from the RFID tag communication control unit 212. In addition, since RSSI is a well-known technique, description is abbreviate | omitted here.

  Although detailed explanation is omitted, in step S1005, when waiting for reception of a response command from the wireless tag T, if the response command cannot be received even after waiting for a predetermined time, the processing of the reader 110 is terminated as it is as a timeout. Alternatively, the search command may be transmitted again after returning to step S1001.

  The control unit 211 determines a light emission current value I for causing the light emitting unit 309 of the wireless tag T to emit light based on the reception intensity V detected in step S1006 (step S1007). Specifically, when the reception intensity V is weak, the control unit 211 sets the light emission current value I so that the light emission intensity (luminous intensity) becomes strong because the wireless tag T exists at a position far from the reader 110. If the reception intensity V is strong, the light emission current value I is determined so that the light emission intensity is weak because the wireless tag T is located near the reader 110.

  Here, the determination of the light emission current value I according to the second embodiment of the present invention will be described with reference to FIG. FIG. 11 is an explanatory diagram showing an example of determination of the light emission current value according to the second embodiment of the present invention. In FIG. 11, the data 1100 for determining the light emission current value I is stored in a ROM or memory (not shown) in the control unit 211 and received from the wireless tag T via the reader antenna AT (response command). ) Received intensity V and the light emission current value I.

  The reception intensity V changes according to the communication distance between the wireless tag T and the reader 110. The reception strength V decreases within the communicable range of the reader 110 and the wireless tag T within the range from the minimum reception strength Vmin to the maximum reception strength Vmax, and becomes weaker as the communication distance between the wireless tag T and the reader 110 increases. And becomes stronger as the communication distance between the reader 110 and the reader 110 becomes shorter.

  Specifically, for example, the maximum reception strength Vmax indicates the reception strength V when the wireless tag T and the reader 110 are in contact with each other, and the minimum reception strength Vmin is a range within which the wireless tag T can communicate with the reader 110. It is good also as showing the receiving strength V in the case of being located in a boundary.

  The light emission current value I is determined according to a desired light emission intensity for the light emitting unit 309. That is, as shown in FIG. 11, the light emission current value I is lower as the communication distance between the wireless tag T and the reader 110 is shorter and the reception intensity V is higher, and the communication distance between the wireless tag T and the reader 110 is longer. It is determined to be higher as V is weaker. In addition, the light emission current value I is determined in the range from the minimum rated current value Imin, which is a current value rated according to the type of the light emitting unit 309, to the maximum rated current value Imax.

  Returning to FIG. 10A, the control unit 211 controls the wireless tag communication control unit 212 based on the light emission current value I determined in step S1007, and sends a light emission command to the wireless tag T via the reader antenna AT. (Step S1008), and based on the operation of the operation unit 213 by the user or the like, it is determined whether or not the search for the file 101 has ended (step S1009).

  In step S1009, when the search is finished (step S1009: Yes), the series of processing of the reader 110 is finished as it is. If the search does not end (step S1009: No), the process returns to step S1001 and the process is repeated.

  Next, the contents of processing of the wireless tag according to the second embodiment of the present invention will be described with reference to FIG. In the flowchart of FIG. 10B, first, the control unit 307 waits for the tag antenna 301 to receive the search command transmitted from the reader 110 in step S1001, and if received (step S1002: Yes) Response processing is performed (step S1003).

  The control unit 307 generates a response command for the reader 110 and transmits the generated response command via the tag antenna 301 when the tag ID matches the tag ID of the search command by the response processing in step S1003. (Step S1004).

  When the response command is transmitted in step S1004, the control unit 307 waits for the tag antenna 301 to receive the light emission command transmitted from the reader 110 in step S1008, and if received (step S1010: Yes), the response Processing is performed (step S1011).

  When performing the response process of the light emission command in step S1011, the control unit 307 switches the energy supply source for operating the wireless tag T to the internal battery 308 (step S1012).

  Based on the light emission command received in step S1010, the control unit 307 issues a light emission command based on the light emission current value I to the light emission unit 309 (step S1013), and ends a series of processing of the wireless tag T. Specifically, for example, when the wireless tag T causes the light emitting unit 309 to emit light in response to the light emission command, the light emission is continued without receiving a new search command for a certain time, and the light emission is stopped after a certain time has elapsed and a new light is emitted. The search command is awaited (for example, the state in step S1002).

  In addition, if the process in each component of the present invention is described in association with each process or each function in the second embodiment of the present invention, the process of the light emission control unit according to the present invention is performed by the process of the control unit 307 in step S1013. Is executed. By the process of the control unit 307 in step S1012, the process of the power control unit according to the present invention is executed.

  As described above, according to the wireless tag and file search system according to the second embodiment of the present invention, the light emitting unit is configured to emit light that is determined according to the reception intensity of the received signal (response command) from the wireless tag. Can emit light. In other words, the wireless tag located at a long distance from the reader has a light emitting mode that is easy for the user to check even from a long distance, and the wireless tag located at a short distance from the reader is sufficient for the user to check at a short distance. It can be set as a light emission mode. Therefore, efficient light emission can be achieved while enabling an appropriate file search.

  In addition, since the wireless tag can be switched to the internal battery before causing the light emitting unit to emit light, the light emitting unit can be caused to emit light stably, and the ease of file search can be improved.

(Other variations)
In the second embodiment of the present invention, the issue current value I is determined using the reception intensity V instead of the response time t used in the first embodiment. Equivalent modifications can be applied. Specifically, for example, the procedure for switching the energy supply source in step S1012 illustrated in FIG. 10 may be performed at any stage before the light emitting unit 309 emits light. In step S1007, instead of (or in combination with) the light emission current value I, a blinking interval, a light emission color, or the like of the light emitting unit 309 may be determined.

  Further, in step S1007 shown in FIG. 10, similarly to step S608 shown in FIG. 6, the reception intensity V and the light emission current value I are set to predetermined values without storing the characteristics of the light emitting elements such as LEDs and organic EL. Although the light emission current value I is determined to be directly proportional to the range, the light emission current value I may be determined after the light intensity and the luminance are determined. That is, the light intensity and the luminance are determined according to the reception intensity V by the control unit 211 of the reader 110. The reader 110 determines the light emission current value I from the light emission characteristics of the light emitting unit 309 according to the determined light intensity and luminance.

  Here, the light emission aspect of the light emission part 309 when a light intensity is determined by the reader | leader 110 concerning the modification of Embodiment 2 of this invention is demonstrated using FIG. In the description of FIG. 12, a case will be described in which an LED is used as the light emitting unit 309, and the luminous intensity is determined according to the reception intensity V in step S1007 shown in FIG.

  FIG. 12 is an explanatory diagram illustrating an example of determination of luminous intensity according to a modification of the second embodiment of the present invention. In FIG. 12, the luminous intensity determination table 1200 is stored in a ROM or memory (not shown) in the control unit 211, and constitutes the reception intensity V between the reader 110 and the wireless tag T and the light emitting unit 309 of the wireless tag T. The relationship with the luminous intensity of LED is shown.

  Specifically, the light intensity is high when the communication distance between the reader 110 and the wireless tag T is long, and is low when the communication distance is short. Intensities L6, L5, and L4 (V4> V5> V6) are determined for reception intensities V4, V5, and V6 (V4 <V5 <V6), respectively. More specifically, for example, the relationship between the reception intensity V and the luminous intensity may be a directly proportional relationship such that when the communication distance is doubled, the luminous intensity is also doubled. And the control part 211 determines the light emission current value I on the characteristic view 400 shown in FIG. 4 about the light intensity determined by the light intensity determination table 1200.

  In the modification shown in FIG. 12 as well, the light emission current value I may be determined by the wireless tag T in the same manner as the modifications shown in FIGS. 8 and 9 in the first embodiment. Further, the case where an organic EL is used as the light emitting unit 309 is substantially the same, and thus the description thereof is omitted.

(Embodiment 3)
Next, a third embodiment of the present invention will be described. In the third embodiment of the present invention, a case where the response time measured by the reader in the first embodiment is measured by a wireless tag will be described. The outline of the file search system according to the third embodiment and the light emission characteristics of the light emitting unit are substantially the same as those in the first embodiment, and thus the description thereof is omitted.

  The functional configuration of the reader according to the third embodiment is the same as that of the reader 110 shown in FIG. 2 except for the timer 216, and the other functional units are almost the same. That is, since the reader 110 does not measure the response time t, the light emission command transmitted to the wireless tag T does not include an instruction regarding the light emission current value I.

  A functional configuration of the wireless tag T in the file search system 100 according to the third embodiment of the present invention will be described with reference to FIG. FIG. 13 is an explanatory diagram illustrating an example of a functional configuration of a wireless tag in the file search system according to the third embodiment of the present invention. In addition, about the functional structure of the wireless tag T, about the structure similar to Embodiment 1, the same code | symbol as FIG. 3 is attached | subjected and only a different part is demonstrated.

  In FIG. 13, the wireless tag T is configured to include a timer 1301 in addition to the configuration illustrated in FIG. 3. That is, the timer 1301 measures various times according to the control of the control unit 307. Although details will be described with reference to FIG. 14, the control unit 307 performs a response process when a search command transmitted from the reader 110 is received via the tag antenna 301. The control unit 307 controls the timer 1301 to transmit a response command to the reader 110 via the tag antenna 301, and then to a response time t from when the light emission command transmitted according to the response command is received from the reader 110. Time.

  Then, the control unit 307 determines a light emission current value I for causing the light emitting unit 309 to emit light based on the light emission command received via the tag antenna 301 and the response time t measured by the timer 1301. The control unit 307 controls the light emission of the light emitting unit 309 based on the determined light emission current value I.

(Contents of file search system processing)
The contents of the process of the file search system 100 according to the third embodiment of the present invention will be described with reference to FIG. FIG. 14 is a flowchart showing the processing contents of the reader and the wireless tag according to the third embodiment of the present invention. The processing contents of the reader according to the third embodiment of the present invention will be described with reference to the flowchart of FIG. 14A, and the processing contents of the wireless tag according to the third embodiment of the present invention will be described with reference to the flowchart of FIG. explain.

  In the flowchart of FIG. 14A, first, the control unit 211 accepts designation of a search target tag (step S1400). The search target tag is designated by, for example, operating the operation unit 213 of the reader 110 and inputting the search target file name in order for the user to search for the file 101.

  The control unit 211 controls the wireless tag communication control unit 212 based on the information input by the operation unit 213 to search for the wireless tag T attached to the search target file 101 via the reader antenna AT. A command is transmitted (step S1401).

  When the control unit 211 of the reader 110 transmits a search command in step S1401, the control unit 211 waits to receive a response command transmitted from the wireless tag T by the reader antenna AT (step S1406: Yes). A light emission command for instructing the wireless tag T to emit light is transmitted via the reader antenna AT (step S1407).

  Although detailed explanation is omitted, in step S1406, when waiting for reception of a response command from the wireless tag T, if the response command cannot be received even after waiting for a predetermined time, the processing of the reader 110 is terminated as it is as a timeout. Alternatively, the search command may be transmitted again after returning to step S1401.

  When transmitting the light emission command in step S1407, the control unit 211 determines whether or not the search for the file 101 has ended based on the operation of the operation unit 213 by the user (step S1408).

  In step S1407, when the search is completed (step S1407: Yes), the processing of the series of readers 110 is terminated as it is. If the search does not end (step S1407: No), the process returns to step S1401 to repeat the process.

  Next, the contents of processing of the wireless tag according to the third embodiment of the present invention will be described with reference to FIG. In the flowchart of FIG. 14B, first, the control unit 307 waits for the tag antenna 301 to receive the search command transmitted from the reader 110 in step S1401, and if received (step S1402: Yes). Then, response processing is performed (step S1403).

  The control unit 307 generates a response command for the reader 110 and transmits the generated response command via the tag antenna 301 when the tag ID matches the tag ID of the search command by the response processing in step S1403. (Step S1404), the timer 1301 is controlled to start counting the response time t (Step S1405).

  When the counting of the response time t is started in step S1405, the control unit 307 waits for reception of the light emission command transmitted from the reader 110 in step S1407 by the tag antenna 301 (step S1409: Yes). Ends the counting of the response time t started in step S1405 (step S1410).

  When the control unit 307 finishes counting the response time in step S1410, the control unit 307 switches the energy supply source for operating the wireless tag T to the internal battery 308 (step S1411).

  The control unit 307 determines a light emission current value I for causing the light emitting unit 309 of the wireless tag T to emit light based on the response time t counted in steps S1405 and S1410 (step S1412). Specifically, when the response time t is long, the control unit 307 sets the light emission current value I so that the light emission intensity (luminous intensity) becomes strong because the wireless tag T exists at a position far from the reader 110. When the response time t is short, the light emission current value I is determined so that the light emission intensity is weakened because the wireless tag T is located near the reader 110.

  More specifically, the control unit 307 is the same as the control unit 211 in the first embodiment from various data shown in FIG. 7 and FIG. 8 in the first embodiment, which are stored in a ROM or memory (not shown). The light emission current value I is determined by the processing.

  Based on the light emission current value I determined in step S1412 and the light emission command received in step S1409, the control unit 307 issues a light emission command based on the light emission current value I to the light emission unit 309 (step S1413). The processing of the wireless tag T is finished. Specifically, for example, when the wireless tag T causes the light emitting unit 309 to emit light in response to the light emission command, the light emission is continued without receiving a new search command for a certain time, and the light emission is stopped after a certain time has elapsed and a new light is emitted. The search command is awaited (for example, the state in step S1402).

  Note that the processing in each component of the present invention will be described in association with each processing or each function in the third embodiment of the present invention. Is executed. The process of the power control unit according to the present invention is executed by the process of the control unit 307 in step S1411.

  As described above, according to the wireless tag and file search system according to the third embodiment of the present invention, since the response time is measured on the wireless tag side, the configuration of the reader is simplified while the configuration of the reader is simplified. The effect equivalent to 1 can be realized.

(Other variations)
In the third embodiment of the present invention, since the response time t used in the first embodiment is measured by the wireless tag T to determine the issue current value I, it is equivalent to each modification shown in the first embodiment. The modified example can be applied. Specifically, for example, the procedure for switching the energy supply source in step S1411 shown in FIG. 14 may be at any stage before the light emitting unit 309 emits light. Further, in step S1412, instead of (or in combination with) the light emission current value I, a configuration in which the blinking interval, the light emission color, or the like of the light emitting unit 309 may be determined.

  Further, in steps S1405 and S1410 shown in FIG. 14, it has been described that the time from when the response command is transmitted by the wireless tag T until the light emission command is received from the reader 110 is counted as the response time. However, it is within this limit. Specifically, the time required for the process of transmitting the light emission command in the reader 110 may be considered.

  The time required for the process of transmitting the light emission command may be set to a predetermined time, for example, or the reader 110 is provided with a timer (for example, the timer 216 shown in FIG. 2), and the command is received in step S1406. In step S1407, a value obtained by actually measuring the time until the light emission command is transmitted may be included in the light emission command and transmitted to the wireless tag T.

  That is, by setting the response time to (the time from when the response command is transmitted by the wireless tag T until the light emission command is received from the reader 110) − (the time required for the process of transmitting the light emission command), A more accurate response time can be employed.

(Embodiment 4)
Next, a fourth embodiment of the present invention will be described. Embodiment 4 of the present invention describes a case where the light emission current value is determined according to the reception intensity of the search command from the reader in the reader and file search system described in Embodiment 3. That is, this is a configuration in which the reception intensity described in the second embodiment is detected by the wireless tag. Note that the outline of the file search system according to the fourth embodiment, the functional configuration of the reader, the functional configuration of the wireless tag, and the light emission characteristics of the light emitting unit are substantially the same as those of the third embodiment, and thus description thereof is omitted.

(Contents of file search system processing)
The contents of the process of the file search system 100 according to the fourth embodiment of the present invention will be described with reference to FIG. FIG. 15 is a flowchart showing the processing contents of the reader and the wireless tag according to the fourth embodiment of the present invention. The content of the processing of the reader according to the fourth embodiment of the present invention will be described with reference to the flowchart of FIG. 15A, and the content of the processing of the wireless tag according to the fourth embodiment of the present invention will be described with reference to the flowchart of FIG. explain.

  In the flowchart of FIG. 15A, first, the control unit 211 accepts designation of a search target tag (step S1500). The search target tag is designated by, for example, operating the operation unit 213 of the reader 110 and inputting the search target file name in order for the user to search for the file 101.

  The control unit 211 controls the wireless tag communication control unit 212 based on the information input by the operation unit 213 to search for the wireless tag T attached to the search target file 101 via the reader antenna AT. A command is transmitted (step S1501).

  When the control unit 211 transmits a search command in step S1501, the control unit 211 waits for the reader antenna AT to receive a response command transmitted from the wireless tag T, and if received (step S1510: Yes), Based on the operation of the operation unit 213 or the like, it is determined whether or not the search for the file 101 has ended (step S1511).

  Although detailed explanation is omitted, in step S1510, when waiting for reception of a response command from the wireless tag T, if the response command cannot be received even after waiting for a predetermined time, the processing of the reader 110 is terminated as a timeout. Alternatively, the search command may be transmitted again after returning to step S1501.

  In step S1511, when the search is finished (step S1511: Yes), the series of processing of the reader 110 is finished as it is. If the search does not end (step S1511: NO), the process returns to step S1501 and the process is repeated.

  Next, the contents of the processing of the wireless tag according to the fourth embodiment of the present invention will be described with reference to FIG. In the flowchart of FIG. 15B, first, the control unit 307 waits for the tag antenna 301 to receive the search command transmitted from the reader 110 in step S1501, and receives the search command (step S1502: Yes). Then, response processing is performed (step S1503).

  When the tag ID of the search command matches the tag ID of the search command in response to the response process in step S1503, the control unit 307 receives the received intensity V according to the output from the modem unit 306 for the search command received in step S1501. Is detected (step S1504), and the energy supply source for operating the wireless tag T is switched to the internal battery 308 (step S1505).

  The control unit 307 generates a response command for the reader 110 and transmits the generated response command via the tag antenna 301 when the tag ID matches the tag ID of the search command by the response processing in step S1503. (Step S1506).

  When the control unit 307 transmits a response command in step S1506, the control unit 307 determines a light emission current value I for causing the light emitting unit 309 to emit light based on the reception intensity V detected in step S1504 (step S1507). Specifically, when the reception intensity V is weak, the control unit 307 sets the light emission current value I so that the light emission intensity (luminous intensity) becomes strong because the wireless tag T exists at a position far from the reader 110. If the reception intensity V is strong, the light emission current value I is determined so that the light emission intensity is weak because the wireless tag T is located near the reader 110.

  More specifically, the control unit 307 is the same as the control unit 211 in the second embodiment from various data shown in FIG. 11 and FIG. 12 in the first embodiment stored in a ROM or memory (not shown). The light emission current value I is determined by the processing.

  Based on the light emission current value I determined in step S1507, the control unit 307 issues a light emission command based on the light emission current value I to the light emission unit 309 (step S1508), and ends a series of processing of the wireless tag T. Specifically, for example, when the wireless tag T causes the light emitting unit 309 to emit light in response to the light emission command, the light emission is continued without receiving a new search command for a certain time, and the light emission is stopped after a certain time has elapsed and a new light is emitted. A search command is awaited (for example, the state in step S1502).

  Note that the processing in each component of the present invention will be described in association with each processing or each function of the third embodiment of the present invention. Is executed. The process of the power control unit according to the present invention is executed by the process of the control unit 307 in step S1505.

  As described above, according to the wireless tag and file search system according to the fourth embodiment of the present invention, the configuration is such that the reception intensity is detected on the wireless tag side and the light emission current value is determined. The effect equivalent to that of the second embodiment can be realized while achieving the above.

(Other variations)
In the fourth embodiment of the present invention, the issue current value I is determined using the reception intensity V instead of the response time t used in the third embodiment, and therefore, the third embodiment (that is, the first embodiment). A modification equivalent to each modification shown in FIG. Specifically, for example, the procedure for switching the energy supply source in step S1505 shown in FIG. 15 may be at any stage before the light emitting unit 309 emits light. In step S1507, instead of (or in combination with) the light emission current value I, a blinking interval or a light emission color of the light emitting unit 309 may be determined.

  In the fourth embodiment of the present invention, in particular, in step S1506 and step S1510 shown in FIG. 15, a response command is transmitted from the wireless tag T and the response command is received by the reader 110. A configuration in which transmission / reception processing is omitted may be used.

  Specifically, the wireless tag T causes the light emitting unit 309 to emit light without transmitting a response command. Since the reader 110 does not receive the response command, the reader 110 cannot confirm whether or not the wireless tag T searched for by the search command exists. However, when the user confirms the light emission of the light emitting unit 309 of the wireless tag T, the reader 110 The wireless tag T (file 101) can be found.

  That is, since the user can easily find the target file 110 without receiving a response command by the reader 110, signal processing in wireless communication between the reader 110 and the wireless tag T can be simplified. . At this time, the user may operate the operation unit 213 to input that the wireless tag T has been found (instead of the response command).

  In the above description, the first embodiment, the second embodiment, the third embodiment, and the fourth embodiment are different examples, but the present invention is not limited to this. That is, as a configuration in which the respective functions are combined, two or more methods according to the above-described first to fourth embodiments and modifications thereof may be used as appropriate.

  Specifically, the first and third embodiments may be combined, the response time may be measured by both the reader and the wireless tag, and the average value of both may be employed. Further, an average value may be adopted for the light emission current value determined from each of the response time and the reception intensity by combining the first and second embodiments. In other words, the light emission mode can be optimized by appropriately combining the response time and reception intensity measured or detected by the reader and the wireless tag, and selecting the average and the optimum value.

T wireless tag 100 file search system 101 file 110 reader AT reader antenna 210 bus 211 control unit 212 wireless tag communication control unit 213 operation unit 214 display unit 215 communication I / F
216, 1301 Timer 301 Tag antenna 302 Rectifying unit 303 Power supply unit 304 Clock extraction unit 305 Memory unit 306 Modulation / demodulation unit 307 Control unit 308 Internal battery 309 Light emitting unit 350 IC circuit unit 700, 1100 Determination data 800, 1200 Light intensity determination table

Claims (5)

A wireless tag including a light emitting unit capable of emitting light when wireless communication is performed with a wireless tag communication device,
The wireless tag against the interrogating wave transmitted from the communication device, wherein acquires the response time information about the response time of the wireless tag communication apparatus in a radio communication from the radio tag communication apparatus, the light emission based on the response time information A wireless tag comprising: a light emission control means for controlling a light emission mode of the unit. The wireless tag according to claim 1 , further comprising: a power supply control unit capable of switching power supply to the wireless tag to an internal power supply when wireless communication is performed with the wireless tag communication device. A wireless tag communication system comprising: a wireless tag communication device; and a wireless tag including a light emitting unit capable of emitting light when wireless communication is performed with the wireless tag communication device,
The wireless tag communication device includes a time measuring unit that measures a response time until the response wave is received from the wireless tag according to the interrogation wave when the interrogation wave is transmitted to the radio tag,
The wireless tag communication system, wherein the wireless tag includes light emission control means for controlling a light emission mode of the light emitting unit based on the response time measured by the time measuring means. The wireless tag communication device further comprises response time transmitting means for transmitting the response time measured by the time measuring means,
The light emission control unit of the wireless tag determines a current value for controlling a light emission mode of the light emitting unit from the response time transmitted by the response time transmitting unit, and based on the determined current value, the light emitting unit The wireless tag communication system according to claim 3 , wherein the light emission mode is controlled. The wireless tag communication device is configured to determine a current value for controlling a light emission mode of the wireless tag based on the response time measured by the time measuring unit;
A light emission instruction signal transmitting means for transmitting a light emission instruction signal based on the current value determined by the determining means to the wireless tag, wherein the light emission control means of the wireless tag is transmitted by the light emission instruction signal transmitting means. 4. The wireless tag communication system according to claim 3 , wherein a light emission mode of the light emitting unit is controlled based on a light emission instruction signal.