CN1926721A - Recording medium IC tag sticking sheet and recording medium - Google Patents

Abstract

There is provided an IC tag which can be stuck directly to a CD. The IC tag comprises a thin planar sheet (10) formed into a shape fitted to the CD, a loop-shaped antenna (101) provided along the circumference of the CD, and an IC chip (102) performing noncontact communication through the antenna. The antenna (10) is formed of a conductor and arranged on the recording region of the CD. Communication has been conventionally impossible when the antenna is arranged on the recording region of the CD, but communication is enabled when an antenna is formed of a conductor.

Description

IC label adhesive sheet for recording media and recording media

technical field

The present invention relates to a sheet for affixing an IC label to a disc-shaped recording medium such as a CD, DVD, and the recording medium affixed with an IC label, and particularly aims to provide a lending management system suitable for libraries system device.

Background technique

Recently, IC tags have attracted attention. An IC tag is a small device that combines an ultra-small IC (Integrated Circuit) chip and an antenna for wireless communication. It uses a wireless communication device called a reader to write data into the IC chip or read it. the data.

If unique ID information (identification information) is recorded on each IC chip and mounted on each product one by one, "single product management" can be performed as shown in the text, so its introduction is widely studied mainly in the field of distribution. In the prior art, barcodes are widely used in the field of circulation, but since IC tags can read and write data non-contact/remotely, and the amount of data that can be stored is also increased, compared with using barcodes, it is possible to for a wider range of uses.

As a management system using IC tags, lending management systems in libraries are gaining popularity. Conventionally, in order to rationalize book management, many libraries have introduced a barcode-type (optical code reading) and OCR (optical character recognition)-type book lending management system. The system that uses barcodes can greatly save energy and improve accuracy, but it is necessary to use a scanner to read books one by one, and it is impossible to read information on multiple books at a time, which is time-consuming.

In order to solve the above-mentioned problems, in recent years, with the goal of further rationalizing the management of books, IC tags with recorded/registered book information are attached to books, and information such as the registration number recorded in the IC chip is read by a reader/writer.

When the user borrows a book, he puts the reader/writer on the book, reads the information of the IC tag attached to the book, performs the lending process, and writes the lending information into the IC tag. When borrowing a plurality of books, it is necessary to process all the books. If the information of any one of the multiple books cannot be read during lending, it is necessary to manually check which book information cannot be read, which is very time-consuming. Therefore, in the lending management system of the library, it is required to be able to communicate reliably with the ICs of all books.

In addition to books, the lending of music CDs and movie DVDs is also increasing day by day in libraries. IC labels are attached to CDs and DVDs (hereinafter collectively referred to as "recording media") as management objects. However, in the prior art, the IC labels are basically attached to the casing of the recording medium, and the IC labels are not directly attached. onto the recording medium. Through the electromagnetic coupling between the antenna of the reader-writer and the antenna of the IC tag, power is supplied to the IC tag and communication is performed at the same time. ) makes the electromagnetic coupling not go on smoothly and communication is impossible.

However, when the IC label is attached to the case, if the middle of the case is empty, or if the case and the middle are inserted incorrectly, proper management cannot be performed. In view of this, it is necessary to compare the outer casing and the middle of the recording medium one by one during management, which is very time-consuming. As a result, the introduction of IC tags is meaningless. Therefore, it is required to directly paste the IC tag on the recording medium.

Patent Document 1: Japanese Unexamined Patent Application Publication No. H11-250494

Patent Document 1 discloses a technique of integrating a non-contact IC tag on a disc-shaped recording medium. Near the central hole of the CD-ROM as a recording medium, a non-contact IC chip of electromagnetic coupling is embedded or pasted, and an antenna is embedded or pasted in the CD-ROM in a manner surrounding the central hole, and on the IC chip Information for identifying each medium and information for confirming the authenticity of the recorded content of the CD-ROM are recorded in the CD-ROM.

Contents of the invention

The problem to be solved by the invention

IC tags pasted on the recording medium, in addition to transmitting and receiving power and signals through electromagnetic coupling, are read-only or writable and readable devices, do not protrude from the surface of the recording medium, and do not cause obstacles when rotating and driving. In addition, in order to apply to the lending management system of the library, the following conditions need to be met.

(1) In the lending management system of the library, the distance to the reader/writer may be several tens of centimeters, so communication must be possible even in this case. And, the interval of the general detection door that is used to detect and take out the article is 90cm, so the reading distance of about half 45cm is preferable (due to the influence of the recording surface of the recording medium, the communication distance of the IC tag is obviously shortened, at least in In the lending management system of the library, IC tags cannot be used by pasting them directly on recording media).

(2) There are cases where multiple books and CDs are borrowed at the same time, so when multiple books/CDs are stacked on the reader/writer, it must be able to communicate with the IC tags of all the books and CDs .

(3) Must be applicable to all recording media handled by the library. IC tags are pasted on recording media in libraries (not pasting in the manufacturing process of recording media, but pasting afterwards), so IC tags must be labels that can be used on arbitrary recording media, but the inventors found that the actual Due to the different types of recording media, the communication performance of IC tags also changes greatly. Although the size/material of the recording medium is limited in the specification, it is actually affected by the printing state (printing thickness, ink type, etc.) on the surface of the recording medium (especially ink containing iron components).

In the IC tag provided with an antenna around the center hole of the CD-ROM disclosed in Patent Document 1 (the recording surface of the aluminum film does not exist in this part, so it is not affected), the diameter of the antenna arranged around the center hole is small, and its communication capability is low. , so it is impossible to communicate a little away (only about 5cm). Therefore, the above conditions (1) and (2) cannot be satisfied. In addition, it is described in paragraph 0018 of the patent document that the antenna is arranged on the outermost periphery of the recording medium, but it is also described in the same paragraph that since the outer peripheral portion is frequently in contact with fingers and components of the CD-ROM drive , so the chance of damaging the IC tag increases, which is not preferable in practical use. This is because, in Patent Document 1, the antenna is limited to the portion other than the recording surface of the aluminum film, that is, the portion other than the information recording area, so the antenna can only be installed on the disk edge of a recording medium having a size of about 1 cm. In Patent Document 1, in order to avoid the influence of the recording surface of the aluminum thin film, it is a basic principle to install an antenna in a portion where the recording surface does not exist.

Furthermore, in the invention disclosed in Patent Document 1, the above-mentioned condition (3) cannot be satisfied. Referring to the whole of Patent Document 1, in this invention, an IC tag is installed in the manufacturing process of the recording medium, and the IC tag is not pasted afterwards after the product is shipped. The patent document is not applicable to various recording media, and ignores the influence of the printing surface of the recording medium, which is important when pasting the IC label afterwards, and cannot be used in the lending management system of the library.

The object of the present invention is to provide an IC label sticking sheet for a recording medium and a recording medium which satisfy the above conditions (1) to (3) and are particularly suitable for a library lending management system.

means of solving problems

The present invention is an IC label sticking sheet for a recording medium, which is used for sticking an IC label to a disk-shaped recording medium containing a recording area for recording information inside, and is characterized in that it has a thin plate-shaped base, which is covered by Formed into a shape suitable for the above-mentioned recording medium; a loop-shaped antenna, which is provided on the above-mentioned substrate; and an IC chip, which communicates in a non-contact manner through the above-mentioned antenna, wherein the cross-section is approximately circular, approximately regular polygonal, or approximately square The above-mentioned antenna is formed by a conductive wire, and the above-mentioned antenna is positioned on the recording area of the above-mentioned recording medium in a state of being pasted on the above-mentioned recording medium.

Preferably, the number of turns and intervals of the lead wires of the antenna are set such that the communication distance of the antenna has little fluctuation in a state of being attached to various types of recording media.

Preferred examples of the number of turns and intervals of the conductive wires of the above-mentioned antenna are as follows.

When the operating frequency is 13.56 MHz and a CD/DVD with a diameter of 12 cm is used as the recording medium, the number of turns of the above-mentioned wires is 4, and the interval between the above-mentioned wires is 0.35 mm or 0.45 mm. The above-mentioned antenna has a diameter of 110 mm, and the cross-sectional diameter φ of the above-mentioned wire is 0.11 mm.

Preferably, the resonant frequency of the antenna in the state before being attached to the recording medium is set to be higher than the usage frequency of the IC chip.

Preferably, the above-mentioned antenna has: a plurality of arc-shaped circumferential portions located on the circumference of the above-mentioned recording medium; The center of rotation is symmetrically arranged between the above-mentioned circumferential parts, and also symmetrically arranged between the above-mentioned non-circumferential parts.

The shape of the above-mentioned antenna is preferably different in shape so that the antennas of the respective recording media do not interfere with each other when a plurality of recording media to which IC tags are attached are stacked. If the antenna has a non-circumferential portion, the shape of the non-circumferential portion can be set arbitrarily, thereby realizing various shapes.

Furthermore, it is preferable to have a counterweight provided at a position symmetrical to the position of the IC chip with respect to the rotation center of the recording medium.

The recording medium according to the present invention is characterized in that it has: a disk-shaped recording medium containing a recording area for recording information inside; a loop-shaped antenna provided on the surface of the recording medium; In the IC chip for communication, the antenna is formed with a wire having a substantially circular or substantially square cross section, and the antenna is positioned on the recording area of the recording medium.

The effect of the invention

According to the present invention, since the antenna is formed with a conducting wire having a substantially circular or substantially square cross section, and the antenna is arranged along the circumference of the recording medium, the communication distance can be extended to a practical level. Furthermore, by appropriately selecting the number of turns and intervals of the conductive wire constituting the antenna, it can be pasted on various recording media and used.

Description of drawings

FIG. 1 is a diagram showing an IC label sticking sheet for recording media according to an embodiment of the present invention. Fig. 1(a) is a top view, and Fig. 1(b) is a cross-sectional view taken along line A-A of the top view.

Fig. 2(a) is a detailed cross-sectional view of the antenna part according to the embodiment of the present invention, Fig. 2(b) is a detailed cross-sectional view of the same IC chip part, and Fig. 2(c) is when the antenna part is formed by printing or etching As a detailed cross-sectional view, FIG. 2( d ) is an example of a top view of an IC chip.

Fig. 3 is a diagram showing a state where the IC label sticking sheet for recording medium according to the embodiment of the present invention is pasted on a recording medium. Fig. 1(a) is a top view, and Fig. 1(b) is a cross-sectional view taken along line A-A of the top view.

4 is actual measurement data of the resonance frequency and the communication distance of the antenna according to the embodiment of the present invention (same CD, number of coils = 4, spacing = 0.35 mm).

5 is actual measurement data of the resonance frequency and the communication distance of the antenna according to the embodiment of the present invention (different types of CD, number of coils=4, interval=0.35mm).

FIG. 6 is actual measurement data of the resonance frequency and the communication distance of the antenna according to the embodiment of the present invention (different types of CDs, number of coils=5, interval=0.35mm).

7 is actual measurement data of the resonance frequency and the communication distance of the antenna according to the embodiment of the present invention (different types of CD, number of coils=5, interval=1.35mm).

8 is actual measurement data of the resonance frequency and the communication distance of the antenna according to the embodiment of the present invention (different types of CDs, number of coils = 4, spacing = 0.45 mm).

FIG. 9 shows the characteristics of the antenna according to the embodiment of the present invention before it is attached to a recording medium.

10 is a plan view showing a non-circular antenna shape according to the embodiment of the present invention.

11 is a plan view showing another non-circular antenna shape according to the embodiment of the present invention.

Label description

1. IC label adhesive sheet for recording media

2. Recording medium

2a. The outer edge of the recording medium

2b. The edge of the inner hole of the recording medium

10. Sheet (substrate)

10a. The outer edge of the sheet

10b. The edge of the inner hole of the sheet

11. Double-sided tape

12. Diaphragm

21. Recording surface of recording medium (aluminum film)

101. Antenna

101a. Circumferential part of antenna

101b. The non-circumferential part of the antenna

102. IC chip

102a, IC chip main body

102b. IC chip mounting department

103. Connecting wire

104. Counterweight

Detailed ways

The IC label sticking sheet for recording media which concerns on embodiment of this invention, and the recording medium sticking this sheet are demonstrated with reference to drawings.

1 is a diagram showing an IC tag sticking sheet for recording media according to an embodiment of the present invention, FIG. 1( a ) is a plan view, and FIG. 1( b ) is a cross-sectional view taken along line A-A of the plan view. In addition, the cross-sectional view is a schematic diagram, and each thickness does not indicate the correct reduced size. In addition, a flat and straight state is shown on the premise that deformation and warpage do not occur. In FIG. 1, 1 is the IC label sticking sheet for recording media which concerns on embodiment of this invention. The IC label sticking sheet 1 for recording media has: a disk-shaped sheet (substrate) 10 having the same shape as a recording medium such as a CD, and slightly smaller than it; slightly inside (for example, about 2.5 mm inside) of the outer edge of the sheet 10 Antenna 101 arranged along the circumference; IC chip 102 for non-contact communication with the outside through antenna 101; connecting wire 103 for connecting antenna 101 to IC chip 102; The center of rotation of the recording medium is positioned symmetrically with the IC chip 102 to achieve rotation balance. Below the IC label sticking sheet 1 for recording media, there is provided: a double-sided tape 11 (for example, thick=about 0.05 mm) for sticking the sheet 1 on the recording medium; Diaphragm 12. The separator 12 is peeled off, and the recording medium IC label sticking sheet 1 is pasted on the recording medium.

The sheet 10 is a base on which the antenna 101 and the IC chip 102 are mounted, and its shape is suitable for a recording medium. Specifically, it is formed in a circular shape. If the diameter of the sheet 10 is the same as or larger than the recording medium, the sheet 10 will affect the rotational drive of the recording medium, so the diameter of the sheet 10 is slightly smaller than the recording medium (for example, the diameter of the recording medium = about 120 mm, the sheet 10 diameter = about 115mm). Inside the sheet 10 , an inner hole having a larger diameter than the inner hole is provided so as not to clog the inner hole for rotationally driving the recording medium. In FIG. 1 , 10 a denotes the outer edge of the sheet 10 , and 10 b denotes the edge of the inner hole of the sheet 10 .

Openings for accommodating the IC chip 102 and the counterweight 104 are provided in the sheet 10 . The surface of the sheet 10 is therefore flat. When the IC chip 102 is thin, the IC chip 102 does not protrude from the sheet 10, and even if it protrudes slightly, there is no problem in practical use (for example, the thickness of the resin (polycarbonate) sheet 10 = about 0.25 mm In the case of an IC chip with a main body height=0.15mm and a mounting portion thickness=0.08mm, it does not protrude onto the sheet 10, while in the case of an IC chip with a main body height=0.3mm and a mounting portion thickness=0.08mm, then will be slightly highlighted).

The antenna 101 (for example, antenna diameter=approximately 110 mm) is formed by winding a plurality of conducting wires having a substantially circular cross section (maybe substantially square or substantially regular polygon). Communication is not possible when the cross section is thin plate or foil like printed wiring, but communication is possible when using a wire with a circular cross section as follows. In addition, as the cross-sectional shape, a regular polygon or a square may be used instead of a circle. The resonant frequency of the antenna 101 is set higher than the usage frequency of the IC chip 102 . After setting in this way, when the IC label sticking sheet 1 for recording media is stuck to the recording medium, the resonant frequency becomes low, and it becomes equal to the use frequency. By configuring the antenna 101 in a circular shape along the outer edge of the sheet 10 as shown in FIG. 1( a ), maximizing the diameter of the antenna 101 improves its advantage. In particular, when at least a part of the antenna 101 has the shape shown in FIG. 1( a ) (for example, refer to FIGS. 10 and 11 ), desired advantages can be obtained.

FIG. 2( a ) shows a detailed cross-sectional view of a part of the antenna 101 . The antenna 101 is composed of four conducting wires 101-1 to 101-4 arranged substantially concentrically. The diameter of the wire is about 0.11. The four conducting wires 101-1 to 101-4 are arranged at a constant interval (pitch) P. It is very important to satisfy the above-mentioned conditions (1) to (3) that the antenna 101 is composed of thin wires. As shown by reference numerals 101'-1 and 101'-2 in FIG. 2(c), when the thickness is smaller than the width of the conductor (typically, when the conductor is formed by printing or etching), it cannot be pasted on the recording medium. Communicate with IC tags. This is because, when formed by etching or the like, it is difficult to increase the thickness of the conductor, and the cross-sectional area cannot be increased. Even if it is formed thicker forcibly, one surface (for example, a side surface) of the conductor becomes thin, and the cross-sectional area cannot be enlarged like a wire. Therefore, the resistance value becomes larger than that of the inductance, and the coil characteristics deteriorate.

On the other hand, when the antenna is constituted by wires as shown in FIG. 2(a), the antenna 101 and the IC chip 102 can be provided on the recording medium area having the recording surface. Patent Document 1 only discloses that the antenna 101 and the IC chip 102 are provided in an area where no recording surface exists, but according to the embodiment of the present invention, there is no need to be limited thereto.

FIG. 2( b ) shows a detailed cross-sectional view of a part of the IC chip 102 . Although it differs depending on the type of IC chip 102, IC chip 102 has a main body 102a and a mounting portion 102b as its base. The IC chip 102 is mounted on the sheet 10 through the mounting portion 102b. The main body 102a is housed in the opening provided in the above-mentioned sheet 10 . FIG. 2( d ) shows an example of a top view of the IC chip 102 . In this example, attachment portions 102b serving also as connection terminals are provided at both ends of the main body 102a. The antenna 101 is connected to these terminals. In addition, a part of the counterweight 104 is also the same as that of FIG. 2( b ).

3 is a diagram showing a state in which the recording medium IC label sticking sheet 1 is mounted on the recording medium, FIG. 3( a ) is a plan view, and FIG. 3( b ) is a cross-sectional view taken along line A-A of the plan view. As can be seen from FIG. 3( a ), the IC label sticking sheet 1 for recording media does not protrude from the recording medium. Therefore, if the thickness of the sheet 1 is set within the range allowed by the recording medium specification, the original function of the recording medium will not be damaged. The antenna 101 and the IC chip are provided on the recording surface (recording area) 21 of the recording medium as shown in FIG. 3( b ).

Next, specific examples of embodiments of the present invention will be described.

FIG. 4 to FIG. 8 are the actual measurement data of changing the number of coils of the antenna 101 and the spacing (pitch) to measure the resonant frequency and the communication distance. A dipmeter is used for the measurement of the resonance frequency. An oscillation circuit is included in the grid sink oscillator, and oscillation energy is displayed in the grid sink oscillator. Make the coil of the grid trap oscillator close to the coil of the resonant circuit to be measured, turn the dial of the measuring instrument, and gradually change the oscillation frequency. When it becomes the resonant frequency, the oscillation energy of the grid trap oscillator is absorbed into the resonant circuit of the measurement object, The pointer in the oscillator falls. From this the frequency of the resonant circuit is measured.

Fig. 4 shows the characteristics when the number of coils = 4 and the pitch = 0.35 mm. Fig. 4(a) is a graph showing resonance frequency and communication distance. The scale on the vertical axis on the right side of the graph represents frequency (unit: MHz), and the scale on the vertical axis on the left represents communication distance (unit: mm) (the same applies to the graphs in and after FIG. 5 ). The horizontal axis represents the number of the recording medium to which the IC tag to be measured is attached. Ten recording media were measured in FIG. 4 . All ten recording media in FIG. 4 are of the same type. On the other hand, the data shown in FIG. 5 and after are data obtained by measuring different types of recording media. Figure 4(b) shows the measured data. The graph of FIG. 4( a ) is a graph representing the data of FIG. 4( b ) in a graph (the same applies hereinafter).

It can be seen from Figure 4 that:

・Because all are the same type of recording medium, there is less fluctuation in the resonance frequency and communication distance of each recording medium;

·The resonant frequency is about 14.5MHz, and the communication distance is about 260mm.

FIG. 5 shows characteristics of different types of recording media with the number of coils = 4, pitch = 0.35 mm. It can be seen from Figure 5 that:

・Because of different types of recording media, the resonance frequency and communication distance of each recording medium fluctuate greatly;

·The resonant frequency is about 14.0MHz, and the communication distance is about 231-270mm.

FIG. 6 shows characteristics of different types of recording media with the number of coils = 5, pitch = 0.35 mm. It can be seen from Figure 6 that:

Due to different types of recording media, the resonance frequency and communication distance of each recording medium fluctuate greatly, especially the fluctuation of communication distance is very large;

·The resonant frequency is 15.00~15.70MHz, and the communication distance is about 222~310mm.

FIG. 7 shows characteristics of different types of recording media with the number of coils = 5, pitch = 1.35 mm. It can be seen from Figure 7 that:

Due to different types of recording media, the resonance frequency and communication distance of each recording medium fluctuate greatly, especially the fluctuation of communication distance is very large;

·The resonant frequency is 14.10~14.40MHz, and the communication distance is about 213~309mm.

FIG. 8 shows the characteristics of different types of recording media with the number of coils = 4, pitch = 0.45 mm. It can be seen from Figure 8 that:

・Because of different types of recording media, the resonance frequency and communication distance of each recording medium fluctuate greatly;

·The resonant frequency is 14.0~14.50MHz, and the communication distance is about 241~280mm.

Comparing Figure 5 and Figure 8, we can see that the fluctuation of the communication distance in Figure 8 is small, and the communication distance is longer. According to Figure 6 and Figure 7, it can be known that when the number of turns is greater than 4, or the pitch increases to 1.35mm, the fluctuation of the communication distance becomes very large. In order to satisfy the above condition (3), it is preferable not to increase the number of turns or to increase the pitch too much.

From the perspective of the lending management system used in the library, the number of turns and the spacing of the wires of the antenna 101 are preferably set to meet the above conditions (1) and (3), that is, it is preferably set to: The communication distance of the above-mentioned antenna is reduced and the fluctuation of the communication distance of the above-mentioned antenna is reduced in the state of pasting on various recording media. Based on the above data, it can be said that the example of Fig. 8 is most suitable for the above conditions (1) and (3).

In addition, when the antenna 101 is attached to a recording medium, it can be seen that its resonance frequency becomes lower. This is presumably caused by capacitive coupling between the antenna and the recording surface of the recording medium. Therefore, it is preferable to set the resonant frequency of the antenna 101 in the state before sticking to the recording medium to be higher than the operating frequency of the IC chip 102 (for example, 13.56 MHz). In this way, the best performance can be exhibited in the usage state of the IC tag. Fig. 9 shows the characteristics of the antenna before being attached to the recording medium (CD). Fig. 9 is an antenna under the same conditions as Fig. 8 . The resonant frequency of the antenna before pasting was 19.2MHz as measured by the grid oscillator, but after pasting on the recording medium, as shown in Fig. 8, it dropped to 14.00-14.50MHz, a drop of about 25%.

An embodiment of the present invention is characterized in that the antenna is not formed by printing or etching, but is formed using conductive wires. This is based on the inventor's knowledge that communication is basically impossible in the state pasted to the recording medium by printing or etching, but communication is possible with a wire. Antennas made of wires cost more than printing and etching, but in the lending management system of libraries, IC tags are attached to recording media after the fact, so they don't need to be used in large quantities, so there is no problem in terms of cost.

As described above, according to the embodiments of the present invention, since the antenna is formed with a conducting wire having a substantially circular cross-section, and the antenna is arranged along the circumference of the recording medium, the outer diameter of the coil antenna can be enlarged and the output can be increased. The distance is extended to a practically usable level. It can be pasted on various recording media and used by appropriately selecting the number of turns and intervals of the conductive wire constituting the antenna. And as a result of the increase in output, the antenna can be placed on the recording area of the recording medium in the state of sticking to the recording medium, so the reliability can be improved. In the conventional method that cannot be placed on the recording medium, the antenna has to be installed on the outer periphery, and the antenna and the IC chip will be damaged if a finger or a component of the driving device touches it, which is not practical.

In the above condition (2), even if multiple books and recording media are stacked and placed on the reader/writer, it must be able to communicate with the IC tags of all books and recording media, which can be satisfied by configuring the antenna as above. the condition. In order to reliably communicate with the IC tags, it is preferable that no interference occurs between the IC tags. One of the methods is to increase the size of the antenna as described above, and prepare antennas of various shapes so that adjacent antennas do not overlap when recording media are overlapped. In the antenna type shown in Figure 1, when the recording media are superimposed, the antennas are all very close to each other, and the antennas close to the reader/writer can communicate, but the antennas farther away are interfered by the closer antennas, making communication difficult.

Even when there are various antenna shapes, it is preferable to arrange at least a part of the antenna along the circumference of the recording medium in order to maximize the area of the antenna. The shape of the antenna can be circular or non-circular as shown in FIG. 1 . The non-circular here means that at least a part of it is a circular arc configured along the circumference of the recording medium, and a part is disposed on the inner side away from the circumference. What is shown in Fig. 10 and Fig. 11(a) is also the non-circular one described here A sort of. In order to ensure the balance of the rotation, it is preferable that the circular arcs arranged along the circumference are symmetrical with respect to the rotation center of the recording medium, and the parts arranged inside the circumference are also symmetrical.

Antenna 101 in FIG. 10 is composed of two circular arcs (circumferential portions) 101a of approximately 1/4 of the circumference and two portions (non-circumferential portions) 101b of a shape that curves approximately 1/4 of the circumference inward. The circumferential portions 101a are arranged symmetrically with respect to the rotation center of the recording medium. The same applies to the non-circumferential portion 101b. The antenna 101 in FIG. 10 has a so-called hammerhead shape.

The antenna 101 in FIG. 11(a) is composed of two circular arcs (circumferential portions) 101a of about 1/6 of the circumference, and a straight line portion (non-circular portion) 101b connecting the ends thereof. The symmetrical arrangement of the circumferential portion 101a and the non-circumferential portion 101b is the same as in FIG. 10 . The antenna shown in FIG. 10 has an approximately rectangular shape. In addition, in FIG. 11 , the sheet 10 does not have to be disc-shaped, for example, it may have a shape similar to the antenna 101 as shown by the dotted line in FIG. 11 . The sheet 10 has a shape suitable for a recording medium, including a shape similar to the antenna of FIG. 11 .

Furthermore, in the above description, an example in which at least a part of the antenna is arranged along the circumference of the recording medium and has an arc shape has been described. However, the same operation and effect can be achieved when the antenna does not have a part along the circumference. When at least a part of the antenna is arranged along the circumference of the recording medium, the area of the recording medium can be used most effectively. However, if the area of the antenna can be enlarged, it does not have to be arranged along the circumference. Fig. 11(b) shows an example of such an antenna. This figure shows the case where the antenna is a square.

By making the shape of the antenna into various shapes shown in FIGS. 1, 10, and 11, even when a plurality of recording media with IC tags attached thereto are stacked, it is possible to prevent the antennas of the respective recording media from interfering with each other. From the viewpoint of preventing interference, it is preferable that the shape of the antenna is different for each recording medium. In the circular antenna shown in FIG. 1, there is a risk of antenna interference even when the recording medium is rotated. However, in the shapes shown in FIG. 10 and FIG. That is, even if a non-circular antenna is used, since the recording medium is oriented in various directions during use, the antennas hardly overlap completely, and the possibility of interference is reduced.

In addition, the loan management system of a library has been described above as an example, but the present invention is not limited to this application. For example, it can be applied to any use that needs to satisfy some or all of the above-mentioned conditions (1) to (3).

The present invention is not limited to the above-described embodiments, and various changes can be made within the scope described in the claims, and of course such changes are also included in the scope of the present invention.

Claims (6)

1. An IC label sticking sheet for a recording medium, which is used to stick an IC label to a disk-shaped recording medium containing a recording area for recording information inside, characterized in that, It has: a thin plate-shaped substrate formed into a shape suitable for the above-mentioned recording medium; a loop-shaped antenna provided on the above-mentioned substrate; and an IC chip for non-contact communication through the above-mentioned antenna, Wherein, the above-mentioned antenna is formed by a conducting wire having a cross-section of substantially circular, substantially regular polygon or substantially square, and the above-mentioned antenna is positioned on the recording area of the above-mentioned recording medium in a state of being pasted on the above-mentioned recording medium. 2. The IC label sticking sheet for recording media according to claim 1, wherein The number of turns and intervals of the lead wires of the antenna are set so that the fluctuation of the communication distance of the antenna is small in a state of being pasted on various recording media. 3. The IC label sticking sheet for recording media according to claim 1, wherein The resonant frequency of the above-mentioned antenna in the state before being attached to the above-mentioned recording medium is set to be higher than the usage frequency of the above-mentioned IC chip. 4. The IC label sticking sheet for recording media according to claim 1, wherein The above-mentioned antenna has: a plurality of arc-shaped circumferential portions located on the circumference of the recording medium; and a plurality of non-circumferential portions located inwardly away from the circumference of the recording medium, The circumferential portions are symmetrically arranged with respect to the rotation center of the recording medium, and the non-circumferential portions are also symmetrically arranged. 5. The IC label sticking sheet for a recording medium according to claim 1, further comprising a counterweight provided at a position symmetrical to a position of the IC chip with respect to a rotation center of the recording medium. 6. A recording medium, characterized in that, It has: a disk-shaped recording medium containing a recording area for recording information therein; a loop-shaped antenna provided on the surface of the recording medium; and an IC chip for non-contact communication via the antenna, The above-mentioned antenna is formed with a wire having a substantially circular or substantially square cross-section, and the above-mentioned antenna is positioned on the recording area of the above-mentioned recording medium.

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