JP2005165473A - Radio tag reading device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To lengthen a response distance for the radio tag and to read the data of all of a plurality of radio tags. <P>SOLUTION: In this radio tag reading device, a reader antenna 6 installed in a reader 7 is moved vertically by an elevating mechanism 8 so that the reading distance of the reader antenna 6 for a plurality of radio tags 2 in a storage box 3 placed on the reader 7 can be made variable, thereby securing the optimal reading distance all the time. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a wireless tag reader that stores a plurality of articles with a wireless tag (RFID) attached to a storage box and reads data from a wireless tag of each article stored in the storage box.

There is a wireless tag reader that stores a plurality of articles attached with wireless tags, such as registered mail, in a storage box, and reads data stored in the wireless tags of each registered mail with a reader disposed outside the storage box. . As such a wireless tag reader, there is known a device that attaches a delivery certificate in which a wireless tag is embedded to a predetermined position such as a registered mail and reads data stored in the wireless tag. (For example, refer to Patent Document 1).
JP 2002-337827 A

  However, in the technique shown in the above publication, since the response distance between the reader antenna provided in the reader and the wireless tag is as short as several millimeters, it is necessary to attach the wireless tag to a predetermined position of the article with high accuracy. Furthermore, there is a restriction that the distance between the wireless tag and the reader antenna must be close. In addition, data of all wireless tags may not be read for a plurality of wireless tags.

  The present invention has been made to solve such a problem, and it is possible to increase the response distance with respect to a wireless tag and to read data of all wireless tags with respect to a plurality of wireless tags. A tag reader is provided.

  The present invention includes a reader antenna connected to an interrogator and a storage box for storing a plurality of articles having wireless tags, and the reader antenna is provided with adjusting means capable of changing a distance from the wireless tag.

  According to the present invention, the distance between the wireless tag and the reader antenna can be optimized, and the data of all the wireless tags can be read with respect to a plurality of wireless tags.

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

  FIG. 1 shows an external configuration of a wireless tag reader according to the present invention. That is, the RFID tag reader is composed of an interrogator 4 and a reader 7 having a reader antenna 6. A personal computer (PC) 10 is connected to the interrogator 4 and the reader 7.

  In FIG. 1, reference numeral 1 denotes an envelope in which a wireless tag (RFID) 2 is attached to the front or back lower end. Each wireless tag 2 attached to a plurality of envelopes 1 stores different ID information. The wireless tag 2 includes an IC chip and an antenna, and information such as ID information is stored in the IC chip. Further, the wireless tag 2 is activated by an electromagnetic wave input from the reader antenna 6, and outputs information in the IC chip from its own antenna.

  Reference numeral 3 denotes a storage box for storing the envelopes 1 side by side, and the storage box 3 is used when the envelope 1 is transferred from the station to the station. Here, the storage box 3 is indicated by a dotted line so that the envelope 1 stored in the storage box 3 can be seen. Reference numeral 4 denotes an interrogator, to which a reader antenna 6 composed of, for example, a planar antenna is connected via a coaxial cable 5. The reader antenna 6 is provided in a reader (mounting table) 7 on which the storage box 3 is mounted. Note that the reader 7 is indicated by a one-dot chain line so that the reader antenna 6 can be seen. The reader antenna 6 is supported by an elevating mechanism 8 and is moved up and down in the direction of arrow a.

  The shape of the reader antenna is not flat but may be a rod or other shapes. The maximum gain direction of the reader antenna 6 is substantially perpendicular to the antenna surface of the reader antenna 6 and faces the bottom surface of the storage box 1. Then, a plurality of envelopes 1 are placed in the storage box 3 in a vertical orientation. As a result, the plurality of wireless tags 2 are arranged on a surface that is substantially perpendicular to the maximum gain direction of the antenna 2.

  Furthermore, a personal computer (PC) 10 is connected to the interrogator 4 via a USB (Universal Serial Bus) or the like.

  FIG. 2 shows a schematic configuration of a control system of the wireless tag reader.

  The PC 10 is an interface connected to a CPU 11 that performs overall control, a ROM 12 that stores a control program, a RAM 13 that temporarily stores data, an input unit 14 such as a keyboard, a display unit 15 that displays various information, and an interrogator 4. (I / F) 16 and an interface (I / F) 17 connected to the reader 7.

  The reader 7 includes a driver 21 controlled by the CPU 11 of the PC 10, a linear motor 22 driven by the driver 21, a lifting mechanism 8 that moves up and down by the linear motor 22, and a reader antenna 6 that moves up and down by the lifting mechanism 8. It is configured.

  Here, distances between the plurality of wireless tags 2 and the reader antenna 6 as shown in FIG. 1 (hereinafter referred to as reading distance) will be described.

  FIG. 3 shows an example of a measurement result when 40 wireless tags 2 arranged at intervals of about 3 mm are read by the reader antenna 6. The wireless tag 2 is arranged so that the arrangement direction of the wireless tags is substantially orthogonal to the maximum gain direction of the reader antenna 6. Here, the wireless tag 2 uses the one corresponding to the 2.4 GHz band. The 2.4 GHz band has an advantage that the reading distance can be made longer than that using the 13.56 MHz band electromagnetic induction system. In the figure, the horizontal axis represents the reading distance between the wireless tag 2 and the reader antenna 6, and the vertical axis represents the number of wireless tags 2 that can be read.

  As shown in the figure, the reading distance is 25 mm to 30 mm and the number of reading sheets is minimal, and the reading distance is 60 to 70 mm and the maximum 40 sheets can be read.

  The reason why the number of images that can be read varies depending on the reading distance is due to the radiation characteristics of the reader antenna or the influence of standing waves caused by the radio waves radiated from the reader antenna being reflected by the wireless tag.

  From this result, it can be seen that the reading distance is desirably about 65 mm.

  However, the optimum distance for reading is not always 65 mm due to variations in the output of the interrogator 4 and variations in the characteristics of the reader antenna 6.

  Therefore, by adopting a configuration in which the reader antenna 6 can be moved up and down by the elevating mechanism 8, the reading distance from the wireless tag 2 can be varied, and the optimum reading distance can always be ensured.

  That is, the CPU 11 of the PC 10 controls the driver 21 to move the reader antenna 6 up and down using the elevating mechanism 8 to change the reading distance between the reader antenna 6 and the wireless tag 2.

  In addition, at the same time as reading is started, the reader antenna may be moved up and down to constantly change the reading distance so as to reliably read all the wireless tags.

  In addition, when a wireless tag is read at a fixed reading distance and the presence of a wireless tag that cannot be read is confirmed, the wireless tag that cannot be read first is read by performing the reading process again while moving the reader antenna up and down. You may make it read by changing distance.

  With the above-described configuration, it is not always necessary to attach the wireless tag to the end portion of the envelope with high accuracy, and even if there is a slight shift in the attaching position, it can be read by moving the reader antenna up and down.

  In this embodiment, an example in which a 2.4 GHz band wireless tag is used to secure a reading distance of several centimeters has been described. However, a similar reading distance can be ensured even in the 900 MHz band.

  Further, in this embodiment, the reader antenna is moved up and down. However, as a method of changing the distance between the wireless tag and the reader antenna, the placing surface of the placing table (illustrated by a one-dot chain line) on which the storage box 3 is placed is moved up and down. You may make it move.

1 is a diagram showing an external configuration of a wireless tag reader according to the present invention. The block diagram which shows schematic structure of a wireless tag reader. The figure which shows the reading result of the wireless tag in the wireless tag reader of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Envelope, 2 ... Wireless tag, 3 ... Storage box, 4 ... Interrogator, 5 ... Coaxial cable, 6 ... Reader antenna, 7 ... Reader, 8 ... Lifting mechanism, 10 ... Personal computer, 11 ... CPU, 12 ... ROM, 13 ... RAM, 14 ... input unit, 15 ... display unit, 16, 17 ... interface, 21 ... driver, 22 ... linear motor.

Claims (2)

A reader antenna connected to the interrogator and a storage box for storing a plurality of articles having wireless tags;
The wireless tag reader according to claim 1, wherein the reader antenna is provided with adjusting means capable of changing a distance from the wireless tag.   The wireless tag reader according to claim 1, wherein the plurality of wireless tags included in the plurality of articles maintain a distance from the reader antenna in a state where the wireless tags are arranged in one or a plurality of rows.

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