JP4644742B2 - RFID tag antenna structure for optical recording media - Google Patents

Description

  The present invention relates to a wireless tag antenna structure for an optical recording medium, and more particularly to a technique suitable for use in a disk-shaped optical recording medium such as a DVD or a CD.

  A wireless tag that transmits high-frequency electromagnetic waves from a reader / writer, receives the electromagnetic waves with a wireless tag having an IC (Integrated Circuit) chip in which unique information is stored, and transmits unique information from the wireless tag to the reader / writer again. System development is thriving. The wireless tag is affixed to, for example, a book or a product, and can be read by a reader / writer to read unique information of the object to be attached. Alternatively, the unique information can be written in the wireless tag. A wireless tag is usually composed of an IC chip and an antenna. When a high-frequency signal is received by the antenna, it is converted into a direct current (DC) component of, for example, about 3 V (volts) by a rectifying part built in the IC chip. Signal processing and transmission processing can be performed with power. For example, the frequency used for the wireless tag has been increased to a high frequency such as the 13.56 MHz band and the UHF band (900 MHz band) and 2.45 GHz band recently.

  As a radio tag antenna, for example, as shown in FIG. 18, a planar circuit type dipole antenna 110 having a length of a half wavelength (λ / 2) with respect to a radio signal is often used. Reference numeral 60 denotes an IC chip provided with the antenna 110, where signal processing and transmission processing are performed. In general, a wireless tag has a communicable distance of about 1 m with a transmission signal from a reader / writer of about 1 W (watts), depending on the shape of the antenna and power consumption in the chip. In addition, when using the UHF band, it is known that the communicable distance can be expanded as compared with the 13.56 MHz band and the 2.45 GHz band.

Here, as a conventional technique using a wireless tag, there are other techniques proposed in Patent Documents 1 to 4 below.
The technology of Patent Document 1 aims to provide an article identification sign with an anti-theft function that can be attached to any article and an article management system using the article identification sign. By mounting the IC chip antenna around the rotation axis of the rotating disk in a circular arc shape, while preventing rotation imbalance (unevenness of rotation), theft prevention of goods such as CDs and DVDs and logistics management are realized. Yes.

  The technology of Patent Document 2 relates to an information recording medium and an information recording medium driving device. For example, as shown in FIG. 1 of Patent Document 2, a security chip storing password information and an antenna for the chip are connected to a CD-ROM. Is directly embedded along the periphery of the rotation axis in a part of the disc (CD-ROM inner non-recording area), and a device for writing and reading the CD-ROM (CD device) has a password authentication function. Only when the non-contact type RF reader / writer is equipped and the password is read out from the security chip of the CD-ROM set in the CD device by the non-contact type RF reader / writer, and the password authentication is correctly performed. The device can be operated by releasing the security lock of the device. This makes it possible to prevent illegal copying of music CDs and the like.

  The technique of Patent Document 3 relates to a non-contact IC tag and a method for manufacturing the same. Even if the optical tag is attached to a circular article such as an optical disk, the reader is not impaired without impairing stability during high-speed rotation of the optical disk or the like. The purpose of the present invention is to provide a non-contact type tag that is excellent in electrical efficiency and capable of stable communication even in communication with a non-contact type IC tag. , A donut shape covering the entire surface of the optical disk), which can be attached to the surface of the optical disk.

  The technology of Patent Document 4 relates to a product case with a resonance tag, and aims to make illegal removal of the resonance tag difficult for a product case with a resonance tag as a sensor. In this storage (product) case, a support plate having the same shape as the surface shape of the case and having a resonance tag fixed on one surface is stacked, and in this state, the storage case, the support plate, and the resonance tag are packaged. Yes.

JP 2003-141650 A JP 2000-57296 A JP 2003-85502 A Japanese Utility Model Publication No. 5-23292

  Here, the CD has a very thin protective layer (dielectric layer) on the side opposite to the information reading surface (laser light irradiation surface) (label surface). In general, the recording layer is easily damaged. Therefore, it is not preferable to attach the antenna directly to the label surface of the CD. Therefore, as disclosed in Patent Documents 1 to 3 above, a CD is generally attached to a wireless tag on an inner peripheral portion where no recording layer is formed.

  However, in the case of an optical recording medium in which a protective layer of the same level as the information reading surface side is formed on the label surface side like DVD, it is not always the best measure to attach it to the inner periphery. Moreover, since the attachment to an inner peripheral part has a restriction | limiting in an attachment area, since the bending process etc. of an antenna are needed, it is not necessarily easy. Furthermore, the impedance of the IC chip connected to the antenna is usually about 500Ω (ohms), but the impedance of a normal dipole antenna is about 72Ω. Therefore, even if the chip and the dipole antenna are connected as they are, impedance is not reduced. Problems such as large matching and degradation of communicable distance occur.

That is, although all of the above Patent Documents 1 to 3 disclose that a dipole antenna is formed inside a CD or DVD, as it is, even if it is connected to an IC chip for a wireless tag with a high impedance, The communication distance is extremely short, and in the worst case, there is a possibility that it cannot be read.
The present invention has been made in view of such a problem, and an object of the present invention is to provide a technique that is simple and small in size and that can ensure necessary reading characteristics.

The wireless tag antenna structure for an optical recording medium of the present invention is an antenna structure for a wireless tag attached to a disk-shaped optical recording medium having a dielectric layer and a metal layer, and the metal layer in the optical recording medium A part or all of the antenna is embedded in the dielectric layer portion where the disk is not formed, and the antenna is provided on the dielectric layer portion on the inner periphery of the disk-shaped optical recording medium, and the disk-shaped The optical recording medium is configured as a curved antenna having a curved shape along the inner periphery of the optical recording medium, and further includes an antenna metal portion and the dielectric of the optical recording medium formed on one or both surfaces of the antenna metal portion. And an antenna dielectric portion having a relative dielectric constant larger than that of the layer.
Here, the curved antenna may be configured as a monopole antenna in which an antenna line extends in one direction along the inner circumference of the disk-shaped optical recording medium.
The curved antenna may be configured as a dipole antenna in which an antenna line extends in both directions along the inner circumference of the disc-shaped optical recording medium.
Furthermore, the dipole antenna may be configured as a folded dipole antenna in which the antenna line is partially folded along the inner circumference of the disc-shaped optical recording medium.
Further, the antenna line width on the outer peripheral side of the folded dipole antenna may be configured to be thicker than the antenna line width on the inner peripheral side.
Further, the antenna line may be formed in a wave shape.

  In order to achieve the above object, a RFID tag antenna structure for an optical recording medium of a technique related to the present invention includes a dielectric, an antenna pattern formed on one surface of the dielectric, and the dielectric And a ground pattern attached to the laser light non-incident surface side of an optical recording medium formed symmetrically on the other surface of the body and having a metal layer that reflects laser light and a dielectric layer that protects the metal layer. It is characterized by that.

  Further, the RFID tag antenna structure for an optical recording medium according to the technology related to the present invention is formed on a dielectric, an antenna pattern formed on one surface of the dielectric, and the other surface of the dielectric. An antenna having a ground pattern is provided, and a part or all of the antenna has a metal layer that reflects the laser beam and a dielectric layer that protects the metal layer symmetrically, and the laser beam is not incident on the optical recording medium. It is embedded in the dielectric layer on the surface side.

  Further, the RFID tag antenna structure for an optical recording medium of the technology related to the present invention has an antenna structure by providing an antenna pattern on one surface of the dielectric and a ground pattern on the other surface of the dielectric. A wireless tag antenna structure for an optical recording medium configured to be attached to an optical recording medium having a dielectric layer and a metal layer on a laser light non-incident surface side, the metal layer of the optical recording medium being the ground pattern The antenna pattern is formed on the surface or inside of the dielectric layer of the optical recording medium in order to constitute the antenna structure.

Here, a planar antenna member having the antenna pattern formed on one surface of the dielectric is provided, and the other surface of the dielectric of the planar antenna member is in contact with the metal layer of the optical recording medium. As described above, the planar antenna member may be embedded in the dielectric layer of the optical recording medium.
A radio tag antenna structure for an optical recording medium according to a technique related to the present invention is an antenna structure for a radio tag attached to a disk-shaped optical recording medium having a dielectric layer and a metal layer, A part or all of the antenna is embedded in a dielectric layer portion where the metal layer is not formed on the recording medium.

Here, the disc-shaped optical recording medium is configured to have the dielectric layer and the metal layer symmetrically about the adhesive layer, and the adhesive layer in which the metal layer is not formed in the optical recording medium. The antenna may be embedded in the layer.
The antenna can be provided in the dielectric layer portion of the inner peripheral portion of the disc-shaped optical recording medium, or can be embedded in the adhesive layer of the inner peripheral portion of the disc-shaped optical recording medium. it can.

Further, the antenna may be configured as a curved antenna having a curved shape along the inner periphery of the disc-shaped optical recording medium.
In addition, a storage case for an optical recording medium with an RFID tag antenna according to a technique related to the present invention has a dielectric layer and a metal layer, and the antenna for the RFID tag is formed on the dielectric layer portion where the metal layer is not formed. A storage case for storing the optical recording medium to which the antenna is attached, wherein a dielectric is provided on the inner surface of the case corresponding to the portion where the antenna is provided when the optical recording medium is stored. .

According to the present invention described above, the following effects and advantages can be obtained.
(1) Since the RFID tag antenna is attached to the dielectric layer on the laser beam non-incident surface side of an optical recording medium having a metal layer and a dielectric layer symmetrical like a DVD, the metal layer of the optical recording medium (reflection The antenna can be easily attached to the optical recording medium safely without damaging the layer or the recording layer. Therefore, even when it is necessary to manage a large amount of optical recording media, it is possible to realize necessary management in a short period of time.

  (2) With a structure in which part or all of the antenna is embedded in the dielectric layer of the optical recording medium, each optical recording medium is managed (production management, anti-theft, etc.) one by one with a wireless tag reader. It becomes possible. In particular, a reading system that performs batch reading at a time in a state where several hundred to several thousand optical recording media are stacked, as compared with the case where it is attached to an exterior of a storage case or the like of an optical recording medium as in the past. It is possible to improve the security by detecting the situation where the optical recording medium itself is pulled out from the storage case or the like.

(3) The antenna pattern is formed on the surface or inside of the dielectric layer of the optical recording medium so that the planar antenna structure is configured using the metal layer of the optical recording medium as the ground pattern of the antenna. As a result, the antenna itself can be reduced in size (thinned) and the cost can be reduced while ensuring the electrical characteristics of the antenna.
(4) Due to the structure in which the antenna is embedded in the dielectric layer portion of the optical recording medium where the metal layer is not formed (for example, the inner periphery of the disk-shaped optical recording medium, etc.) Even when hundreds of media are stacked and read by a reader / writer at a time, no extra space is created between the optical recording media, so the total thickness of the stacked status is the original thickness of the optical recording media. Therefore, the reader / writer system can be prevented from being scaled up (a larger number of sheets can be read at the same time in the same system).

  (5) By providing a dielectric (for example, having a relative dielectric constant greater than 1) on the inner surface of the storage case corresponding to the portion where the antenna of the optical recording medium is provided when the optical recording medium is stored, Since the dielectric is in close contact with the antenna surface attached to the recording medium, the wavelength of the received signal can be shortened, and the antenna size can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure for demonstrating the RFID tag antenna structure for optical recording media as 1st Embodiment, (A) is a schematic plan view of DVD (Digital Versatile Disk) as a disk-shaped optical recording medium, (B). FIG. 2 is a schematic cross-sectional view of the DVD shown in FIG. 2A and 2B are diagrams showing a first modification of the RFID tag antenna structure of the first embodiment, wherein FIG. 1A is a schematic plan view of a DVD as a disk-shaped optical recording medium, and FIG. 1B is a schematic diagram of the DVD shown in FIG. FIG. 6A and 6B are diagrams showing a second modification of the RFID tag antenna structure according to the first embodiment, in which FIG. 5A is a schematic plan view of a DVD as a disk-shaped optical recording medium, and FIG. 5B is a schematic diagram of the DVD shown in FIG. A cross sectional view taken along arrow A 6A and 6B are diagrams showing a third modification of the RFID tag antenna structure according to the first embodiment, wherein FIG. 5A is a schematic plan view of a DVD as a disk-shaped optical recording medium, and FIG. 5B is a schematic diagram of the DVD shown in FIG. FIG. 6A and 6B are diagrams illustrating a fourth modification of the RFID tag antenna structure of the first embodiment, in which FIG. 5A is a schematic plan view of a DVD as a disk-shaped optical recording medium, and FIG. 5B is a schematic diagram of the DVD shown in FIG. FIG. It is a figure which shows the 5th modification of the RFID tag antenna structure of 1st Embodiment, (A) is a typical top view of DVD as a disk-shaped optical recording medium, (B) is a model of DVD shown to (A). FIG. It is a figure for demonstrating the RFID tag antenna structure for optical recording media as 2nd Embodiment, (A) is a typical top view of CD as a disk-shaped optical recording medium, (B) is (A). It is typical A arrow sectional drawing of CD shown. It is a figure for demonstrating the other RFID tag antenna structure for optical recording media as 2nd Embodiment, (A) is a schematic top view of DVD as a disk-shaped optical recording medium, (B) is (A). It is typical A arrow sectional drawing of CD shown to). FIGS. 8A and 8B are diagrams showing a case where a monopole antenna is applied on the assumption that the antenna mounting structure shown in FIG. 7 is used. FIG. 8A is a schematic plan view of a CD as a disk-shaped optical recording medium, and FIG. It is typical A arrow sectional drawing. FIGS. 8A and 8B are diagrams showing a case where a dipole antenna is applied on the assumption that the antenna mounting structure shown in FIG. 7 is used. FIG. 8A is a schematic plan view of a CD as a disk-shaped optical recording medium, and FIG. FIG. It is a typical top view which shows the modification of the antenna shown in FIG. FIG. 11 is a schematic plan view showing a structure in which a dummy chip (or another IC chip) is provided in the structure shown in FIG. 10. FIG. 11 is a schematic plan view showing a structure in which a weight balance adjusting hole is provided in a peripheral portion of a dielectric body in the vicinity of an IC chip in the structure shown in FIG. It is typical sectional drawing which shows the structure of the antenna itself provided in a dielectric body surrounding part in FIGS. It is a typical external view which shows the state which attached the dielectric material for the antenna provided in DVD or CD to the storage case of DVD or CD. It is a schematic diagram which shows the reader / writer antenna system which concerns on 1st and 2nd embodiment. (A)-(C) are all the schematic diagrams which show the shape of the slot (antenna) formed in the holder shown in FIG. It is a top view which shows the structure of the existing dipole antenna.

[A] Description of First Embodiment FIG. 1 is a diagram for explaining a radio tag antenna structure for an optical recording medium as a first embodiment of the present invention. FIG. 1 (A) shows a disk-shaped optical recording medium. FIG. 2B is a schematic plan view of a DVD (Digital Versatile Disk), and FIG. 3B is a schematic cross-sectional view of the DVD shown in FIG.
As shown in FIG. 1, the DVD 1 has the same configuration as a CD (compact disc) in appearance, and has dimensions according to standardized specifications [for example, an inner diameter of 1.5 cm, an outer diameter (diameter) of 12 cm, A structure in which two discs having a thickness of 0.6 mm] are bonded with an adhesive is common. That is, two discs formed by forming a reflection layer (metal layer) 12 (12A, 12B) functioning as a light reflection surface on one surface of a dielectric substrate (dielectric layer) 11 (11A, 11B), It has a structure in which the reflective layers 12 are bonded together with an adhesive (adhesive layer) 13 so as to face each other. In FIG. 1, a recording layer on which information such as characters, sounds, images, images, and data is recorded is not shown.

Here, the dielectric substrate 11 (11A, 11B) also functions as a protective layer for protecting the reflective layer 12 and the recording layer, respectively, and is generally formed of, for example, polycarbonate. However, the present invention is not limited to this, and it may be formed of another transparent resin material that transmits laser light such as acrylic resin.
The reflective layer 12 (12A, 12B) is a layer that reflects laser light for reading information, and is made of an alloy material such as silver or gold, and is formed on the dielectric substrate 11 by sputtering film formation or the like. The As the adhesive layer 13, an ultraviolet curable resin is generally used.

  In this embodiment, as shown in FIGS. 1A and 1B, the printing surface (label surface: opposite to the writing / reading surface of this DVD 1 (the lower side in FIG. 1B)). A wireless tag having a patch antenna (planar antenna) 2 and a small IC chip (1 mm or less square: not shown) in a partial region of the dielectric substrate 11 (11A) constituting the laser beam non-incident surface Is formed, and the patch antenna 2 is accommodated and fixed together with the IC chip (communication circuit chip) in the recess 111. In the following description, the term “patch antenna 2” may mean the entire wireless tag including the patch antenna 2 and the IC chip.

  The depth of the recess 111 depends on the size (thickness) of the patch antenna 2, but is the same depth as the thickness of the dielectric layer 11A (that is, the depth at which the reflective layer 12A is partially exposed) or less. It is formed at a depth that does not reach the reflective layer 12A. Therefore, the patch antenna 2 may be completely embedded in the dielectric substrate 11A, or may be embedded in a state where a part thereof is exposed on the label surface. However, it is preferable in view of appearance and collective reading by a reader / writer to be described later that it is completely embedded in the dielectric substrate 11A and the surface thereof is covered with a label.

  It is also possible to embed the patch antenna 2 in the same manner as described above for the CD. However, as described above, in the CD, the protective layer (dielectric material) on the side opposite to the information reading surface (laser light irradiation surface) (label surface) Layer) is very thin, which is not preferable. In other words, if the optical recording medium has a dielectric layer (protective layer) with a layer thickness on which the patch antenna 2 can be embedded without affecting the reading and writing of information on the laser light non-incident surface side, It can be applied in the same way.

  In addition, as shown in FIG. 1B, the patch antenna 2 itself includes a flat dielectric 21, an antenna pattern (antenna layer) 22 formed on one surface of the dielectric 21, and the other. A structure having a ground (GND) pattern (GND layer) 23 formed on the surface, for example, a wavelength (for example, a ½ wavelength) whose length and width correspond to a target communication frequency It is formed in a square shape.

  The length of the patch antenna 2 determines the resonance frequency, and the width determines the ratio band. The antenna pattern 22 and the GND pattern 23 are each formed of a conductive film such as a copper foil. Further, since the dielectric material 21 used for the patch antenna 2 can be reduced in size if the relative dielectric constant is 1 or more, the size of the specific dielectric constant is not specified, but the smaller the value, the smaller the dielectric constant. It is possible.

  As described above, the structure in which the wireless tag (patch antenna 2) is embedded in the dielectric layer 11 of the DVD 1 allows the DVD 1 to be managed one by one (production management or Anti-theft etc.). In particular, in this example, since the patch antenna 2 is embedded in the DVD 1 itself, as compared with the case where the patch antenna 2 is attached to the exterior of a DVD case or the like as in the prior art, from several hundred pieces as will be described later with reference to FIGS. Improve security by reducing the size of a reading system that reads in batches of thousands of DVDs 1 at a time, or by detecting situations where the DVD 1 itself is removed from a DVD case, etc. It is possible to plan.

  In the above-described example, only one patch antenna 2 is attached to the DVD 1, but a dummy antenna or another patch antenna may be provided symmetrically as indicated by a dotted line 2a in FIG. Good. In this way, the weight balance (rotation balance) of the DVD 1 can be achieved, and the occurrence of rotation unevenness can be minimized. Further, when another patch antenna is added instead of the dummy antenna, the communication capacity can be increased. The point that a dummy antenna for rotation balance or another patch antenna can be provided in this way is the same in the structures shown in FIGS.

(A1) Description of First Modification FIG. 2 is a diagram showing a first modification of the RFID tag antenna structure according to the first embodiment described above. Also in this example, (A) is a disc-shaped optical recording medium. FIG. 2B is a schematic plan view of the DVD, and FIG. 3B is a schematic cross-sectional view of the DVD shown in FIG.
As shown in FIG. 2, the DVD 1 of this modification also has the same configuration as the CD in appearance, and has an inner diameter of 1.5 cm, for example, an outer diameter (diameter) of 12 cm and a thickness of 0.6 mm. Reflective layer (metal layer) 12 (12A, 12B) that functions as a light reflecting surface on one surface of a dielectric substrate (dielectric layer) 11 (11A, 11B), that is, a structure in which two discs are bonded with an adhesive. ) Are bonded together by an adhesive (adhesive layer) 13 so that the light reflecting layers 12 face each other. In FIG. 2, the recording layer on which information such as characters, sounds, images, images and data is recorded is not shown.

  Further, the dielectric substrate 11 (11A, 11B) also functions as a protective layer for protecting the light reflecting layer 12 and the recording layer, respectively, as described above with reference to FIG. 1, for example, polycarbonate or acrylic resin. The reflective layer 12 (12A, 12B) that is formed of a transparent resin material that is transparent to the laser beam such as and reflects the laser beam for reading information is also composed of an alloy material such as silver or gold, for example. It is formed on the dielectric substrate 11 by a sputtering film forming method or the like. As for the adhesive layer 13, an ultraviolet curable resin is generally used.

  Also in this modified example, as shown in FIG. 2B, a printing surface (label surface) opposite to the writing / reading surface of this DVD 1 (the lower surface of the paper in FIG. 2B) is configured. A hollow portion (space) 111 for accommodating the patch antenna (planar antenna) 2 ′ is formed in a partial region of the dielectric substrate 11 (11 </ b> A). Here, the depth at which the reflective layer 12 </ b> A is exposed is formed. It is formed to reach up to.

  Unlike the patch antenna 2, the patch antenna 2 'has a structure (planar antenna) in which only the antenna pattern 22 is formed on one surface of the dielectric 21 and the GND pattern 23 is not formed on the other surface. The surface of the planar antenna member on which the GND pattern 23 is not formed is disposed in contact with the exposed surface of the reflective layer (metal layer) 12A. Thus, the reflective layer 12A of the DVD 1 can function as the GND pattern of the patch antenna 2 ′.

In other words, in this modification, the patch antenna 2 ′ (antenna) is configured so that the planar antenna structure as shown in FIG. 1B is configured with the metal layer 12A of the DVD 1 as the ground pattern of the patch antenna 2 ′. The pattern 22) is formed on the surface or inside of the dielectric layer 11A of the DVD 1.
Thus, the patch antenna 2 (see FIG. 1) having a structure in which the antenna pattern 22 and the GND pattern 23 are formed on both surfaces of the dielectric 21 and function as an antenna by itself (ensures electrical characteristics). Then, even if the thickness exceeds the thickness of the dielectric layer 11 of the DVD 1, the electrical characteristics of the patch antenna 2 ′ can be obtained by using the reflective layer 12 of the DVD 1 as the GND pattern of the patch antenna 2 ′. It is possible to embed in the dielectric layer 11 of the DVD 1 while ensuring the characteristics. Therefore, the patch antenna 2 ′ itself can be reduced in size (thinned), and the cost can be reduced.

  2B shows a state in which the depth of the recess 111 is deeper than the thickness of the patch antenna 2 ′, and the patch antenna 2 ′ is completely embedded in the dielectric layer 11A. The pattern 22 may be embedded so that the surface of the pattern 22 is located in the same plane as the surface of the dielectric layer 11A other than the recess 111 or is exposed on the surface. Further, as shown in FIG. 2B, when the patch antenna 2 'is completely embedded in the dielectric layer 11A, the resin is applied from above the patch antenna 2' so that the surface of the dielectric layer 11A becomes flat. It is preferable to perform planar processing by filling a material or the like.

(A2) Description of Second Modification FIG. 3 is a diagram showing a second modification of the RFID tag antenna structure according to the first embodiment of the present invention. Also in this example, (A) is a disc-shaped optical recording medium. 2B is a schematic plan view of the DVD shown in FIG. 1A, and in this example, the dielectric layer 11A of the DVD 1 is compared with the structure shown in FIG. The patch antenna 2 '(antenna pattern 22) in which the recess 111 is not formed and the GND pattern 23 is not formed is attached to the surface of the dielectric layer 11A of the DVD 1 via the dielectric 21 or directly. In addition, the dielectric layer 11A below the patch antenna 2 'provided with the IC chip 24 connected to the patch antenna 2' is provided with a through hole 112 communicating with the reflective layer 12A of the DVD 1. Mainly different.

  In FIG. 3, the parts denoted by the same reference numerals as those already described are the same as or similar to those already described unless otherwise specified. In FIG. 3, the dielectric 21 in parentheses means that the patch antenna 2 ′ is disposed directly on the surface of the dielectric layer 11 </ b> A of the DVD 1. 4 and FIG. 5 have the same meaning.

  That is, the structure of this example uses (also serves as) the dielectric layer 11 (11A) of the DVD 1 as a dielectric that is a constituent element of the patch antenna 2 ′, and also uses the reflective layer 12 (12A) of the DVD 1 in the first modification. Similar to the example, the electrical characteristics of the patch antenna 2 'can be ensured by using (also serving as) the GND pattern that is a constituent element of the patch antenna 2'.

  The through hole 112 plays a role of enabling the GND connection with the reflective layer 12A of the DVD 1 by connecting a GND terminal (not shown) of the IC chip 24 to one end thereof. That is, the reflective layer 12A of the DVD 1 in this modification example has both the function as the GND pattern of the patch antenna 2 'and the function as the GND terminal of the IC chip 24.

  With this structure, in this modification, the patch antenna component in which the antenna pattern 22 is formed on one surface of the dielectric 21 is placed on the dielectric layer 11 (11A of the DVD 1) with the other surface of the dielectric 21 facing down. Or the antenna pattern 22 only directly on the dielectric layer 11 (11A), the original antenna structure of the patch antenna is configured and the original electrical characteristics are secured. A wireless tag can be easily attached to such a thin disc-shaped optical recording medium.

  Further, since the dielectric layer 11 (11A) of the DVD 1 is provided with a through hole 112 for GND connection between the GND terminal of the IC chip 24 and the reflective layer (metal layer) 12 (12A) on the DVD 1 side, the IC chip. Therefore, it is not necessary to provide a dedicated GND pattern 24, greatly contributing to the downsizing of the patch antenna 2 '(wireless tag), and the mounting area on the DVD 1 can be reduced.

(A3) Description of Third Modification FIG. 4 is a diagram showing a third modification of the RFID tag antenna structure according to the first embodiment described above. Also in this example, (A) is a disc-shaped optical recording medium. FIG. 3B is a schematic plan view of the DVD, and FIG. 3B is a schematic cross-sectional view of the DVD shown in FIG. 1A. In this example, the structure described above with reference to FIG. The main difference is that the surface IC chip 24 is embedded in the dielectric layer 11A of the DVD 1 in a vertically placed state so as to be in direct contact with the antenna pattern 22 of the patch antenna 2 'and the reflective layer 12A of the DVD 1. ing.

  That is, in this example, the signal terminal (not shown) provided on the side surface of the IC chip 24 is directly connected to the antenna pattern 22 without using the through hole 112 as described above according to the second modification. In addition, the GND terminal provided on the side surface opposite to the side surface is directly connected to the reflective layer 12A of the DVD 1 directly. In this example as well, portions denoted by the same reference numerals as those already described are the same as or similar to those already described.

With this structure, the same effect as in the second modified example can be obtained in this modified example, and the through hole 112 described above need not be formed, so that the processing is simple.
(A4) Description of Fourth Modified Example FIG. 5 is a diagram showing a fourth modified example of the RFID tag antenna structure of the first embodiment described above. Also in this example, (A) is a disc-shaped optical recording medium. FIG. 4B is a schematic plan view of the DVD, and FIG. 4B is a schematic cross-sectional view of the DVD shown in FIG. 1A. In this example, the structure described above with reference to FIG. Basically, the antenna pattern 22 (or the antenna pattern 22 and the dielectric 21) of the patch antenna 2 'is a band-like portion along the circumference of the disk in part or all of the region where the reflective layer 12 (recording layer) of the DVD 1 is formed. It is mainly formed on the dielectric layer 11A of the DVD 1 so as to cover (annular), and a through hole 112 similar to that described above with reference to FIG. 3 is formed in the dielectric layer 11A of the DVD 1. Different.

That is, also in the structure of this example, the dielectric layer 11 (11A) of the DVD 1 is used as the dielectric of the patch antenna 2 ′, and the reflective layer 12 (12A) of the DVD 1 is used as the patch antenna as in the first modification. It is structured to ensure the electrical characteristics of the patch antenna 2 'by using (also serving as) a GND pattern that is a component of 2'.
In particular, in the case of this modification, since the antenna area can be increased, it is possible to expect improvement in communication sensitivity and communication distance. In addition, also in this modification, the GND terminal of the IC chip 24 connected to the patch antenna 2 ′ is reflected on the DVD 1 by the through hole 112 communicating with the reflective layer 12 A of the DVD 1, similarly to the structure described above with reference to FIG. By connecting to the layer 12A, the GND of the IC chip 24 can be shared by the reflective layer 12A of the DVD1. Therefore, in this case as well, there is no need to provide a dedicated GND pattern on the IC chip 24, which greatly contributes to the downsizing of the patch antenna 2 '(wireless tag), and the mounting area on the DVD 1 can be reduced. .

In this modification as well, as described above with reference to FIG. 4, it is possible to adopt a structure in which the IC chip 24 is embedded in the dielectric layer 11A of the DVD 1 in a vertically placed state.
(A5) Description of Fifth Modification FIG. 6 is a diagram showing a fifth modification of the RFID tag antenna structure of the first embodiment described above. Also in this example, (A) is a disc-shaped optical recording medium. A schematic plan view of a DVD, (B) is a schematic cross-sectional view of the DVD shown in FIG. (A), but in this modification, an antenna pattern 22 is formed on one surface of the dielectric 21 and an other surface is formed on the other surface. The patch antenna 2 on which the GND pattern 23 is formed is structured to be bonded and fixed with an adhesive or the like to the surface of the upper dielectric layer 11A of the reflective layer 12A, which becomes the label surface of the DVD 1. In FIG. 6 as well, the portions denoted by the above-described reference numerals are the same as or similar to the above-described reference numerals.

In this manner, the patch antenna 2 can be attached to the label surface side of the DVD 1 because the thickness of the dielectric layer 11A on the label surface side of the DVD 1 is the same as that of the dielectric layer 11B on the reading surface side of the DVD 1. This is because they have the same thickness and high resistance to scratches.
Therefore, it is possible to attach the patch antenna 2 to the DVD 1 safely and safely without damaging the reflective layer 12 and the recording layer of the DVD 1 as compared with the CD. Therefore, even when it is necessary to manage a large number of DVDs 1, it is possible to realize necessary management in a short period of time.

[B] Description of Second Embodiment FIG. 7 is a diagram for explaining a radio tag antenna structure for an optical recording medium according to a second embodiment of the present invention. FIG. 7 (A) shows a disk-shaped optical recording medium. FIG. 2B is a schematic plan view of the CD, and FIG. 3B is a schematic cross-sectional view of the CD shown in FIG.
As shown in FIG. 7, CD3 has an inner diameter of 1.5 cm, an outer diameter (diameter) of 12 cm, and a thickness of 0.6 mm. Generally, as shown in FIG. 7B, a dielectric substrate (dielectric material) A reflection layer (metal layer) 12 functioning as a light reflection surface is formed on one surface of the layer 11, and a protective layer 14 is further formed thereon. In FIG. 7, the recording layer on which information is recorded is not shown.

In this embodiment, the dielectric substrate 11 also functions as a protective layer that protects the reflective layer 12 and the recording layer, and is formed of a transparent resin material that transmits laser light, such as polycarbonate or acrylic resin. .
The reflection layer 12 is a layer that reflects laser light for reading information, and is made of, for example, an alloy material such as silver or gold, and is formed on the dielectric substrate 11 by sputtering film formation or the like.

The protective layer 14 is a printing surface on which a label or the like is printed, and is much thinner than the thickness of the dielectric substrate 11. Therefore, as described above, when the protective layer 14 is scratched, Generally, the reflective layer 12 and the recording layer are more easily damaged than the body substrate 11 side. Therefore, in the case of CD3, it is not preferable to form an antenna on the label surface.
Therefore, in this embodiment, as shown in FIG. 7B, the reflection layer 12 (recording layer) is not formed, the maximum diameter is within the inner diameter of the reflection layer 12, and the minimum diameter is the inner diameter of the dielectric substrate 11. The antenna 4 is formed on the inner periphery 15 of the dielectric body (see the hatched portion) as described above. That is, for example, as shown in FIG. 7B, a space (groove portion) for embedding part or all of the antenna 4 is provided in the dielectric inner peripheral portion (hereinafter simply referred to as “inner peripheral portion”) 15. The antenna 4 is attached to the space. Such a structure can be similarly applied to the DVD 1 described above. In the case of the DVD 1, for example, as shown in FIG. 8, a space for embedding the antenna 4 is provided between the two reflective layers 12A and 12B (that is, the adhesive layer 13), and the antenna 4 is embedded in the space. It can also be structured.

7 and 8, the size and shape of the antenna 4 are not specified. Therefore, the illustration of the antenna 4 is omitted in the schematic plan views shown in FIGS. 7A and 8A. [Only the example of the attachment location of the antenna 4 is specified in the schematic cross-sectional views of the arrow A shown in FIGS. 7B and 8B].
As described above, a part or all of the antenna 4 is embedded in the inner peripheral portion 15 where the reflective layer (metal layer) 12 of the DVD 1 or CD 3 is not formed, so that the reflective layer (metal layer) of the DVD 1 or CD 3 is obtained. ) Since the influence (performance deterioration due to the disturbance of the magnetic field) as when the antenna 4 is arranged on 12 can be suppressed to the minimum, deterioration of the antenna performance can be suppressed. Further, by providing the antenna 4 in the inner peripheral portion 15, it is possible to maintain the rotational stability of the DVD 1 and the CD 3.

  Furthermore, in the structure in which the antenna 4 is completely embedded in the inner peripheral portion 15 of the DVD 1 or CD 3, as will be described later, in the production management of the DVD 1 or CD 3, these are stacked with hundreds of sheets and read at once by a reader / writer or the like. Even when it is performed, no extra space is created between the disks, so the total thickness of the stacked state can be made the original thickness of DVD1 or CD3 x the number of sheets, and the reader / writer system is prevented from becoming large-scale (A larger number of readings can be made at the same time on the same system).

Hereinafter, the mounting structure of the antenna 4 including the specific shape of the antenna 4 will be described in more detail.
(B1) Case of Monopole Antenna FIG. 9 is a diagram showing a case where a monopole antenna is applied to the antenna 4 on the premise of the antenna mounting structure shown in FIG. 7, and (A) is a CD as a disc-shaped optical recording medium. (B) is typical A sectional view taken on the line shown to (A).

  As shown in FIG. 9, in this example, as the antenna 4, an antenna line is bent in an arc shape along the inner periphery of the CD 3 (the antenna line extends in one direction along the inner periphery). A pole antenna is applied, and the monopole antenna 4 is partially or entirely embedded in the space formed in the inner peripheral portion 15 as described above with reference to FIG. Specifically, in FIG. 9, the monopole antenna 4 and the IC chip 24 are bonded and fixed to the upper surface of the inner peripheral portion 15 of the dielectric substrate 11, and the GND terminal (not shown) of the IC chip 24 is used as the reflection layer of the CD3. The structure is connected to the (metal layer) 12. That is, in this case, the reflection layer (metal layer) 12 of the CD 3 also serves as the GND of the IC chip 24.

(B2) In the case of a dipole antenna FIG. 10 is a diagram showing a case where a dipole antenna is applied to the antenna 4 on the premise of the antenna mounting structure shown in FIG. 7, and (A) is a schematic diagram of a CD as a disk-shaped optical recording medium. (B) is a schematic cross-sectional view taken along arrow A shown in (A).
As shown in FIG. 10, in this example, as the antenna 4 embedded in the inner peripheral portion 15 of CD3 (or DVD1), the antenna line of a small dipole antenna is partially folded and the antenna line width on the outer peripheral side is increased. A folded dipole antenna formed thicker than the antenna line width on the circumference side is applied. In FIG. 10 as well, portions denoted by the same reference numerals as those already described are the same as or similar to those already described.

  Here, the reason why the folded dipole antenna is applied is mainly for impedance matching with the IC chip 24. That is, since the impedance of the IC chip 24 for a radio tag is usually higher than the impedance of the antenna line portion, the reception information can be converted into an IC chip simply by making the antenna line portion a simple arc as shown in FIG. Therefore, it is necessary to increase the impedance of the antenna line portion so as to be equal to the impedance of the IC chip 24.

  Therefore, in this example, as described above, the two antenna lines of the dipole antenna are folded back in a state where a part of the ring is cut to form a loop shape centering on the IC chip 24 ( At this time, the antenna lines are made not to overlap each other. By making the antenna line length and forming the outer antenna line width wider than the inner antenna line width, it is about 4 times that of a normal dipole antenna. The impedance is increased as described above.

As a result, the impedance of the antenna line portion can be increased to be approximately the same as the impedance of the IC chip, and impedance matching between the antenna line portion and the IC chip 24 can be achieved. Characteristic).
In the structure of this example, as will be described later with reference to FIGS. 16 and 17, when a large number of CDs 3 are stacked for batch reading in production management of CDs 3, the dielectric layers 11 are in close contact with both sides of each antenna 4. Therefore, the effective dielectric constant around the antenna line is higher than that of air, the wavelength of the received signal can be shortened, and the required antenna line length is read by a single CD3 (DVD1). It is also possible to shorten the length.

  Note that the number of turns of the antenna line may be two or more. Also, in order to ensure sufficient reading even with a single CD3 (or DVD1), when it is desired to ensure a longer antenna line length, for example, as shown in FIG. 11, the antenna line is bent into a wavy line. Even when the antenna 4 is attached to the antenna 4 (inner peripheral portion 15) as in this example, there is a restriction on the area, and the necessary antenna line length can be ensured. Also in this case, as in the case of FIG. 10, the impedance is gained by making the outer antenna line width wider than the inner antenna line width.

(B3) Description of Modified Example As described above with reference to FIG. 10 (FIG. 11), when the folded (wavy line) dipole antenna 4 is provided on the inner peripheral portion 15 of the CD3 or DVD1, it is symmetric with the location of the IC chip 24. In order to maintain the weight balance (rotation balance) of CD3 or DVD1, a dummy chip 25 (or another IC chip instead of a dummy) may be provided, for example, as shown in FIG. Further, as shown in FIG. 13, one or more holes (weight balance adjusting holes) 16 are formed in the substrate of the inner peripheral portion 15 near the portion where the antenna line portion or the IC chip 24 is provided and the weight increases. It is possible to keep the rotational balance of the DVD 1 or CD 3 by reducing the weight of the portion.

Further, the antenna 4 (antenna line) includes an antenna metal portion 41 and a dielectric portion (antenna) on both surfaces (or one surface) of the antenna metal portion 41 as shown in a schematic sectional view of FIG. A structure having a dielectric portion 42 may be used.
Thus, by forming the dielectric portion 42 on both surfaces or one surface of the antenna metal portion 41, the wavelength of the received signal can be shortened also in this case, and the required antenna line length can be shortened to reduce the size of the antenna. Can be realized. For example, the polycarbonate, which is a dielectric material of DVD1 or CD3, has a relative dielectric constant εr = 2.94. Therefore, a dielectric material having a larger relative dielectric constant is formed on both surfaces or one surface of the antenna metal portion 41. Thus, the size can be reduced as compared with the case where polycarbonate is used as the dielectric of the antenna 4.

Specifically, for example, when alumina (relative permittivity = 10) is formed on both surfaces of the antenna metal part 41 with a thickness of about 0.6 mm, polycarbonate (relative permittivity = 2.94) of DVD1 or CD3 is used as a dielectric. The antenna size can be reduced to about 0.7 times as compared with the case of doing so.
In addition, for example, as schematically shown in FIG. 15, the center of the lid 6 of the DVD1 or CD3 storage case (product case) 5 (the lid 6 that coincides with the inner peripheral portion 15 of the DVD1 or CD3 when the lid 6 is closed). By forming a dielectric 61 having a relative permittivity larger than the relative permittivity of air (εr = 1) on the inner surface of the DVD 1 or CD 3 in the storage case 5 and closing the lid 6, Since the dielectric 61 is in intimate contact with the upper surface of the antenna 4 provided in the portion 15, the antenna size can be reduced also in this case. In this case, if the relative dielectric constant of the dielectric 61 is greater than 1, the antenna size can be reduced. Therefore, the relative dielectric constant is not specified, but the larger the value, the smaller the dielectric can be achieved. It is. For example, when the alumina having a thickness of 2 mm (relative dielectric constant = 10) is formed on the inner surface of the lid 6 as the dielectric 61, the antenna size is reduced by about 0.63 times compared to the case where it is not formed (air). can do.

The dielectric 61 may be formed not on the lid 6 but on a portion (case bottom surface) that coincides with the inner peripheral portion 15 of the DVD 1 (CD 3) on the storage case 5 side, or on both the lid 6 and the storage case 5 side. You may form in. When both are formed, further reduction in antenna size can be expected.
Thus, there is an advantage that the degree of freedom of the antenna pattern (shape) provided on the inner peripheral portion 15 can be improved by reducing the antenna size. Further, by forming the antenna pattern small toward the center of the inner peripheral portion 15, the antenna pattern can be kept away from the reflective layer 12 and the recording layer (metal layer) of the DVD 1 and CD 3, so that the influence of the metal layer on the antenna 4 is minimized. There is also an advantage that it can be made smaller.

Of course, as the small antenna 4 provided on the inner peripheral portion 15 of the DVD 1 or the CD 3, for example, a fractal antenna, a spiral antenna, a log-peri antenna, or the like can be applied.
[C] Description of Collective Reading of DVD1 (CD3) with Radio Tag (Antenna) In recent years, the use of radio tags has been proposed as a part and inventory management system in production and distribution fields. In the case of managing the production and distribution of optical recording media, there is a demand that a large number of wireless tags attached to the DVD 1 or CD 3 can be collectively read as much as possible at once. However, if a large amount of DVD1 or CD3 is stacked, the configuration of the reading system may be complicated due to the influence of the metal layer such as the reflective layer 12 or the recording layer of DVD1 or CD3.

  Therefore, for example, a reader / writer antenna system 7 as schematically shown in FIG. 16 is prepared. This antenna system 7 includes a hollow cylindrical holder (waveguide) 71 having a diameter smaller than the diameter of a hole provided in the center of a disc-shaped optical recording medium such as DVD1 or CD3. A large number of DVDs 1 and CDs 3 can be stacked on 71 with their central axes aligned.

Here, the entire holder 71 or its outer surface or inner surface is a conductor, and the holder 71 is linear (see FIG. 17A) or obliquely (see FIG. 17B) or spiral [see FIG. The slot antenna 72 is configured by forming a thin notch (slot) of about λ / 2 in C).
A large number of DVDs 1 and CDs 3 are collectively read by communicating with the wireless tags (the antennas 2, 2 'or 4) of the DVD 1 and CD 3 stacked on the holder 71 through the slot antenna 72. Thus, a large amount of DVD1 and CD3 can be authenticated (production and distribution management) in a short time.

This antenna system 7 communicates with the wireless tag through the central hole of DVD1 or CD3, so the influence of the metal layer such as the reflective layer 12 or recording layer of DVD1 or CD3 can be reduced, and the reading performance is improved. Is possible.
Needless to say, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

[D] Appendix (Appendix 1)
A wireless tag antenna structure for an optical recording medium,
A dielectric,
An antenna pattern formed on one surface of the dielectric;
A ground pattern formed on the other surface of the dielectric and attached to the laser light non-incident surface side of the optical recording medium having a metal layer that reflects the laser light and a dielectric layer that protects the metal layer symmetrically; A wireless tag antenna structure for an optical recording medium, comprising:

(Appendix 2)
A wireless tag antenna structure for an optical recording medium,
An antenna comprising a dielectric, an antenna pattern formed on one surface of the dielectric, and a ground pattern formed on the other surface of the dielectric;
Part or all of the antenna is embedded in the dielectric layer on the laser beam non-incident surface side of the optical recording medium having a symmetrical metal layer that reflects the laser beam and a dielectric layer that protects the metal layer. A wireless tag antenna structure for an optical recording medium.

(Appendix 3)
Light having an antenna pattern on one surface of the dielectric and a ground pattern on the other surface of the dielectric to form an antenna structure, and having a dielectric layer and a metal layer on the laser light non-incident surface side A wireless tag antenna structure for an optical recording medium attached to a recording medium,
The antenna pattern is formed on the surface of or inside the dielectric layer of the optical recording medium so as to form the antenna structure using the metal layer of the optical recording medium as the ground pattern. RFID tag antenna structure for optical recording media.

(Appendix 4)
A planar antenna member having the antenna pattern formed on one surface of the dielectric;
The planar antenna member is embedded in the dielectric layer of the optical recording medium so that the other surface of the dielectric of the planar antenna member is in contact with the metal layer of the optical recording medium. The RFID tag antenna structure for an optical recording medium according to appendix 3.

(Appendix 5)
A communication circuit chip to be connected to the antenna has the ground terminal connected to the metal layer of the optical recording medium through a through hole provided in the dielectric layer of the optical recording medium. The RFID tag antenna structure for optical recording media according to appendix 3, wherein the RFID tag antenna structure is configured on a surface of a dielectric layer of the media.

(Appendix 6)
The communication circuit chip to be connected to the antenna is embedded in the dielectric layer of the optical recording medium such that the ground terminal is connected to the metal layer of the optical recording medium. A wireless tag antenna structure for an optical recording medium according to appendix 3.
(Appendix 7)
The antenna pattern has a concentric circle shape covering a part or all of the metal layer formed in a ring shape in the disk-shaped medium as the optical recording medium, and the dielectric pattern is directly or directly on the surface of the disk-shaped medium. The RFID tag antenna structure for an optical recording medium according to appendix 3, wherein

(Appendix 8)
The antenna pattern has a concentric shape covering a part or all of the metal layer formed in a ring shape in the disk-shaped medium as the optical recording medium, and is embedded in the dielectric layer of the disk-shaped medium. The RFID tag antenna structure for an optical recording medium according to appendix 3, wherein

(Appendix 9)
An antenna structure for a wireless tag attached to a disk-shaped optical recording medium having a dielectric layer and a metal layer,
A wireless tag antenna structure for an optical recording medium, wherein a part or all of the antenna is embedded in a dielectric layer portion of the optical recording medium where the metal layer is not formed.

(Appendix 10)
The disk-shaped optical recording medium is configured to have the dielectric layer and the metal layer symmetrically about the adhesive layer, and the optical recording medium in the adhesive layer where the metal layer is not formed. The wireless tag antenna structure for an optical recording medium according to appendix 9, wherein the antenna is embedded.
(Appendix 11)
The RFID tag antenna structure for an optical recording medium according to appendix 9, wherein the antenna is provided on the dielectric layer portion of the inner periphery of the disk-shaped optical recording medium.

(Appendix 12)
11. The RFID tag antenna structure for an optical recording medium according to appendix 10, wherein the antenna is embedded in the adhesive layer on the inner periphery of the disk-shaped optical recording medium.
(Appendix 13)
13. The RFID tag antenna structure for an optical recording medium according to appendix 11 or 12, wherein the antenna is configured as a curved antenna having a curved shape along the inner periphery of the disk-shaped optical recording medium. .

(Appendix 14)
The communication circuit chip to be connected to the curved antenna is provided on the inner periphery of the optical recording medium so that the ground is connected to the metal layer of the optical recording medium. RFID antenna structure for optical recording media.
(Appendix 15)
15. The optical recording according to appendix 13 or 14, wherein the curved antenna is configured as a monopole antenna in which an antenna line extends in one direction along the inner circumference of the disk-shaped optical recording medium. RFID tag antenna structure for medium.

(Appendix 16)
15. The optical recording medium according to appendix 13 or 14, wherein the curved antenna is configured as a dipole antenna in which an antenna line extends in both directions along the inner circumference of the disk-shaped optical recording medium. RFID tag antenna structure.
(Appendix 17)
18. The optical recording medium according to appendix 16, wherein the dipole antenna is configured as a folded dipole antenna in which the antenna line is partially folded along the inner circumference of the disk-shaped optical recording medium. Wireless tag antenna structure.

(Appendix 18)
18. The RFID tag antenna structure for an optical recording medium according to appendix 17, wherein an antenna line width on the outer peripheral side of the folded dipole antenna is configured to be thicker than an antenna line width on the inner peripheral side.
(Appendix 19)
19. The RFID tag antenna structure for optical recording media according to any one of appendices 16 to 18, wherein the antenna line is formed in a wave shape.

(Appendix 20)
Note that a dummy chip or another communication circuit chip for maintaining the rotational balance of the disk-shaped optical recording medium is provided at a position of the inner peripheral portion that is symmetrical to the arrangement position of the communication circuit chip. 14. A wireless tag antenna structure for an optical recording medium according to 14.
(Appendix 21)
15. The radio for an optical recording medium according to appendix 14, wherein a hole for maintaining a rotational balance of the disk-shaped optical recording medium is provided in the inner peripheral portion in the vicinity of the arrangement position of the communication circuit chip. Tag antenna structure.

(Appendix 22)
The antenna includes an antenna metal portion, and an antenna dielectric portion formed on one or both surfaces of the antenna metal portion and having a relative dielectric constant greater than that of the dielectric layer of the optical recording medium. The RFID tag antenna structure for an optical recording medium according to any one of appendices 9 to 21, wherein the RFID tag antenna structure according to any one of appendices 9 to 21 is configured.

(Appendix 23)
A storage case for storing an optical recording medium having a dielectric layer and a metal layer, wherein an antenna for a wireless tag is attached to a dielectric layer portion where the metal layer is not formed;
A storage case for an optical recording medium with an RFID tag antenna, wherein a dielectric is provided on an inner surface of the case corresponding to a portion provided with the antenna when the optical recording medium is stored.

  As described above in detail, according to the present invention, it is possible to provide a wireless tag antenna structure for an optical recording medium that is simple, simple, small, and capable of securing necessary reading characteristics. It is considered extremely useful for technical fields such as production management of optical recording media, product management, and theft prevention.

1 DVD (optical recording medium)
11, 11A, 11B Dielectric substrate (dielectric layer)
12, 12A, 12B Reflective layer (light reflecting surface)
13 Adhesive (adhesive layer)
14 Protective layer 15 Perimeter of dielectric body 16 Weight balance adjustment hole 2, 2 'Patch antenna (planar antenna)
21 Dielectric 22 Planar antenna pattern (antenna layer)
23 Planar ground (GND) pattern (GND layer)
24 IC chip 25 Dummy chip 3 CD
4 Antenna 5 Storage case (product case)
6 Lid 61 Dielectric 7 Reader / Writer Antenna System 7
71 Holder (waveguide)
72 slot antenna 112 through hole

Claims (6)

An antenna structure for a wireless tag attached to a disk-shaped optical recording medium having a dielectric layer and a metal layer,
A part or all of the antenna is embedded in the dielectric layer portion where the metal layer is not formed in the optical recording medium,
The antenna is configured as a curved antenna having a curved shape along the inner periphery of the disc-shaped optical recording medium, provided on the dielectric layer portion of the inner peripheral portion of the disc-shaped optical recording medium, Further, the antenna metal portion and an antenna dielectric portion formed on one or both surfaces of the antenna metal portion and having a relative dielectric constant larger than that of the dielectric layer of the optical recording medium are provided. A wireless tag antenna structure for an optical recording medium, characterized by being configured as described above.   2. The optical recording medium according to claim 1, wherein the curved antenna is configured as a monopole antenna in which an antenna line extends in one direction along the inner circumference of the disk-shaped optical recording medium. RFID tag antenna structure.   2. The optical recording medium according to claim 1, wherein the curved antenna is configured as a dipole antenna in which an antenna line extends in both directions along the inner circumference of the disk-shaped optical recording medium. Wireless tag antenna structure.   4. The optical recording medium according to claim 3, wherein the dipole antenna is configured as a folded dipole antenna in which the antenna line is partially folded along the inner circumference of the disk-shaped optical recording medium. RFID tag antenna structure.   4. The RFID tag antenna structure for an optical recording medium according to claim 3, wherein an antenna line width on the outer peripheral side of the folded dipole antenna is configured to be larger than an antenna line width on the inner peripheral side.   4. The RFID tag antenna structure for an optical recording medium according to claim 3, wherein the antenna line is formed in a wave shape.

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