JP2012257081A - Optical disk medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical disk medium such as a CD and a DVD which does not deteriorate the communication distance even if an RFID function is included, which improves the information reading performance and achieves stable operations.SOLUTION: An optical disk medium is enclosed by a recording surface including a metal layer and has nonmetallic regions around a center hole. RFID modules, located on a front surface and a rear surface of the optical disk medium and having loop circuits at the nonmetallic regions, are provided so as to be offset from each other by an angle ranging from 30 degrees to 90 degrees. An IC mounting portion of each RFID module is provided at an area within a 8.5 mm to 11.0 mm radius from the center of the RFID module.

Description

  The present invention is, for example, a plate-like recording medium having an annular metal layer integrated with a recording surface, in particular, an optical disk medium such as a CD or a DVD, and improves operational stability and information reading performance. The present invention relates to an optical disc medium having an RFID (Radio Frequency IDentification) function capable of performing the above. Specifically, the present invention relates to an optical disc medium having a metal layer and having no problem with respect to stability of operation and information reading performance that occurs when an RFID module is provided.

  An RFID tag that can be attached to an optical disk medium such as a CD has been proposed. However, when the inner diameter of the metal layer connected to the recording surface is CD, it is φ38 mm. However, when mounting on a DVD is assumed, the inner diameter of the metal layer connected to the recording surface is φ25 mm, so the tag antenna can be designed. The area becomes very narrow.

  For this reason, it is very difficult to form a radiating element particularly matched to the wavelength of the UHF band (λ = 32 cm), and the radiating element is close to the metal surface integrated with the ground pattern or the recording surface of the medium. An IC chip having a very low radiation gain as an antenna and an input capacitance of about 1 pF is usually connected to the power supply unit. However, a matching circuit for canceling this capacitance and matching with the antenna cannot be formed.

  In the case of this method, the direction of the current induced in the metal layer of the medium is basically determined by the situation (angle) where the RFID module is attached to the medium, and the module is a dipole antenna in which the direction of the element is exactly aligned with that direction. And the media works as one. However, the dipole antenna has a null point with respect to the extending direction of the element, and in this system, it is difficult to read from the direction of the current induced in the metal layer of the media (Patent Document 1).

  Although not publicly known, an RFID module having an IC chip matching function using a winding by an electromagnetic coupling method (HF [13.56 MHz] or UHF [953 MHz]) as an antenna is mounted at the center of a CD / DVD as an optical disk medium. An application has been filed for a method of attaching to the hole (Patent Document 2).

  In the electromagnetic field coupling type RFID tag, the winding antenna is surrounded by a metal layer integrated with the recording surface over the entire circumference, and a current induced in the winding antenna is generated in the metal layer. Since the current is canceled by the reverse current, the reception sensitivity of the RFID tag is lowered. In particular, DVD has a lower conductor resistance of a metal layer integrated with a recording surface than CD, and therefore, when an RFID tag is attached to DVD, reception sensitivity is remarkably lowered.

  In particular, when the RFID tag is attached to a DVD having a small inner diameter of the metal layer, as described above, the area in which the antenna of the RFID tag can be formed is very narrow compared to the case of attaching to the CD. For this reason, when an HF band RFID tag is used, it is difficult to form an antenna (several turns of winding) in this region. In a DVD having a small inner diameter of a metal layer, an area where an RFID tag antenna can be formed is generally an annular area surrounded by a circle having an outer diameter of 25 mm and a circle having an inner diameter of 15 mm.

  Furthermore, although not publicly known, a method of attaching a strap carrying a matching circuit and an RFID chip so as to be electrically coupled to a recording surface including a metal layer has been filed (Patent Document 3).

  However, in the case of the strap method, since the strap is not attached to the outer peripheral portion of the recording medium, the strap is attached to the inner peripheral side. However, the matching loop circuit formed on the strap radiates as an antenna. The gain is very low, and an IC chip having an input capacitance of about 1 pF is usually connected to the power supply unit. However, a matching circuit for canceling this capacitance and matching with the antenna is not formed, resulting in a decrease in impedance. It is.

  Even if power is supplied to a metal surface that is electrically connected to the strap and integrated with the recording surface, the supplied power is short-circuited by a loop on the inner diameter side of the metal surface, and the entire metal surface However, the communication performance as a tag is lowered.

  Since the tag winding antenna is surrounded by a metal surface that is integrated with the recording surface, the current induced in the winding is canceled by the reverse current generated on the metal surface, resulting in a decrease in tag reception performance. Resulting in. In particular, in the case of DVD, since the conductor resistance of the metal surface integrated with the recording surface is lower than that of CD, the reception performance is remarkably deteriorated.

  On the other hand, when a UHF band RFID tag is used, it is advantageous in terms of communication to form an antenna (one-turn winding) so as to surround a central hole (diameter of about 15 mm) opened in the center of the DVD. However, when the antenna is formed so as to surround the central hole, the imaginary part of the impedance of the winding is compared with the absolute value of the imaginary part (for example, about 150 [jΩ]) of the impedance due to the general input capacitance of the RFID chip. Thus, the value is about twice as large.

  For this reason, when the antenna is formed so as to surround the central hole, the impedance mismatch loss increases, the communication sensitivity as the RFID tag decreases, and the information reading performance required for the RFID tag is sufficiently exhibited. This may cause a problem that it becomes difficult. Further, in the above-described strap-type RFID tag, there is no space in the outer peripheral portion of the optical disk medium in which the strap can be attached, so the strap is attached to the inner peripheral side of the optical disk medium.

  However, even in the case of a strap-type RFID tag, when the RFID tag is attached to a DVD whose metal layer has a small inner diameter, the input impedance of the RFID chip is canceled as in the RFID tag described in Patent Document 1. Since it is difficult to form a matching circuit for matching with the impedance of the antenna, the impedance is lowered.

  Even if power is supplied to the metal layer integrated with the recording surface electrically connected to the strap, the power supplied to the metal layer is short-circuited by a loop formed on the inner diameter side of the metal layer. Therefore, it does not spread over the entire metal layer, and almost no electric power is emitted.

  Therefore, even in the strap type RFID tag, similarly to the magnetic field coupling type RFID tag, the communication sensitivity as the RFID tag is lowered, and it is difficult to sufficiently display the information reading performance required for the RFID tag. The problem of becoming may occur.

  In particular, when considering attachment of a tag to a DVD, the range in which the tag antenna can be formed is very narrow (range of outer diameter φ25 mm, inner diameter 15 mm). It becomes difficult to form a winding of turns. Similarly, when a UHF band tag is applied, it is advantageous in terms of communication to form an antenna (one turn winding) so as to surround the central hole (φ15 mm).

  However, in that case, the imaginary part impedance of the winding becomes a value about twice as large as the absolute value of the imaginary part impedance (for example, 150 jΩ) due to the general input capacitance of the RFID chip, resulting in a large impedance mismatch loss. The communication performance as a tag is reduced.

JP 2007-166573 A Japanese Patent Application No. 2010-025182 Japanese Patent Application No. 2010-037116

  The present invention solves such a problem in the prior art, and even if it is an optical disc medium such as a CD or a DVD and has an RFID function, the communication distance does not drop and the information reading performance can be improved. It is an object of the present invention to provide an optical disc medium that can be operated and is stable.

  As means for solving the above-mentioned problems, the invention according to claim 1 is an optical disc medium surrounded by a recording surface including a metal layer and having a non-metal region around a central hole, and The optical disk medium is characterized in that RFID modules having a loop circuit in a non-metallic region are provided with the orientation being shifted between 30 ° and 90 ° between the front and back sides. Here, the direction of the RFID module means the direction of a line segment connecting the rotation center of the RFID module and the optical disk medium.

  According to a second aspect of the present invention, in the optical disk medium according to the first aspect, the IC mounting portion of the RFID module is provided within a radius of 8.5 mm to 11.0 mm from the center of the RFID module. It is.

  According to a third aspect of the present invention, an optical disc medium having a non-metallic region surrounded by a recording surface including the metal layer and an RFID module having the loop circuit is integrally molded. 3. The optical disk medium according to claim 1, wherein the optical disk medium is the optical disk medium.

  According to a fourth aspect of the present invention, the RFID module having the loop circuit is bilaterally symmetric, or a shape in which each region can be equally divided from the center thereof, and the target portion from the rotation center of the RFID chip mounting portion is formed. The optical disk medium according to any one of claims 1 to 3, wherein a dummy RFID chip or a metal foil pattern having a mass equivalent to that of the RFID chip is provided, and a center of rotation and a center of gravity are made to coincide with each other.

  The invention according to claim 5 is characterized in that a common recognition code is recorded in each data recording area of an RFID module having a loop circuit provided on the front and back of an optical disk medium. The optical disc medium according to any one of the above.

  According to the present invention, it is possible to provide an optical disc medium having an RFID function, such as an optical disc medium such as a CD and a DVD, which has an RFID function with stable operation and no problem in communication distance and information reading performance.

It is the plane and cross-sectional conceptual diagram which showed the structure of RFID module 1 of this invention. It is the conceptual diagram which showed the function of RFID module 1 of this invention. 1 is a conceptual diagram showing the appearance of a DVD that is an optical disk medium 9. FIG. It is the conceptual diagram which showed the function of RFID module 1 which has two loop circuits 6 of this invention. The loop circuit 6 of the present invention is a conceptual diagram showing the function of one RFID module 1. CD / DVD player also has a disk fixing part FIG. 3 is a conceptual diagram showing a place where an RFID chip 5 of an RFID module 1 attached with an optical disk medium 9 is mounted. The CD / DVD player is also a conceptual diagram showing a disk fixing situation. It is a conceptual diagram of the metal corresponding | compatible RFID tag which showed the state which provided the dummy RFID chip | tip 19 for center-of-gravity adjustment of this invention. It is a conceptual diagram of the metal corresponding | compatible RFID tag 1 which showed the state which provided the metal foil pattern 20 for center-of-gravity adjustment of this invention. It is a cross-sectional conceptual diagram of the optical disk medium 9 to which the RFID module 1 of the present invention is integrally molded with resin or the like.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. FIG. 1 shows a configuration of an RFID module 1 according to the present invention. A patterned metal foil 3 is provided on a substrate 2 and an adhesive material 4 is laminated thereon. The metal foil 3 is formed so as to form a loop circuit 6, and an RFID chip 5 is mounted thereon.

  FIG. 2 shows the function of the RFID module 1. The current is induced by being induced in the first current path 7 and the second current path 8.

  FIG. 3 shows the appearance of a DVD as an optical disk medium 9, which has a medium fixing hole 12 in the center of a donut shape, a metal layer non-containing portion 11 around it, and a reflective layer 24 on the outside thereof, which contains a metal layer. This is the configuration of the unit 10.

  In FIG. 4, the RFID module 1 having two loop circuits 6 is provided with a hole that is almost the same size as the hole in the center of the optical disk medium 9 near the center of the module. It is pasted so that the hole in the center is put together.

  The RFID module 1 is composed of a matching circuit composed of two or more loop circuits 6 having different current circulation directions and an RFID chip 5 electrically connected to the matching circuit, and at least one loop circuit of the RFID module. 6 is affixed in such a manner that it is electrically connected to the edge of the metal layer containing part 10 of the optical disk medium 9 to be affixed (particularly the edge of the hole provided in the metal body). It is united.

  Also, at this time, the direction of the line segment connecting the rotation center of the RFID module 1 and the optical disk medium 9 on the front and back sides (hereinafter referred to as the direction of the RFID module) is orthogonal to each other when viewed from directly above, or at least 30 ° or more Set to difference. As a result, the null point direction 13, which is the direction in which the RFID module 1 cannot be read, is different, and substantially functions without a null point.

In FIG. 5, the RFID module 1 with one loop circuit is attached to the recording surface (back) 22 side and the label surface (front) 23 of the metal layer non-containing part 11 in the center of the optical disc medium 9. At this time, the orientations of the RFID modules 1 on the front and back sides are set to be orthogonal to each other when viewed from directly above, or to an angle difference of at least 30 ° or more. As a result, the null point direction 13, which is the direction in which the RFID module 1 cannot be read, is different, and substantially functions without a null point.

  The two RFID modules can function independently without interfering with each other, and the metal-compatible RFID tag 1 combining the two RFID modules and the metal layer functions as an independent dipole antenna with different radiating elements. As a result, at least one of the RFID modules 1 can be recognized from any direction.

  The RFID module 1 attached to the back and front of the optical disk medium 9 respectively identifies the optical disk medium 9 by writing a common recognition code in the data recording portion (memory) and reading either one of the modules. Is possible.

  By keeping the total thickness of the metal foil 3, the adhesive material 4 and the base material 2 excluding the RFID chip 5 of the RFID module 1 to 0.1 mm or less, the existing module is attached to the CD / DVD as it is. If the module is pasted after applying a slight amount of polishing, the total thickness of the CD / DVD after the module is pasted may be kept within 1.2 mm + 0.3 mm and −0.1 mm as defined by the standard. It becomes easy.

  FIG. 6 shows a disc fixing portion 16 of a CD / DVD player, in which a media fixing hole 12 of an optical disc medium 9 is set and fixed on a ring-shaped rubber stopper 18 by a plunger 17.

  FIG. 7 shows a place where the RFID module 1 and the RFID chip 5 are mounted on the optical disk medium 9, and a region where the distance R from the center of the module is 8.5 mm or more and 11.0 mm or less is patterned. It is mounted on the loop circuit 6.

  FIG. 8 shows the situation of the CD / DVD player disk fixing portion 16. Since the optical disk medium 9 is set on the ring-shaped rubber stopper 18 and fixed by the plunge 17, the RFID chip 5 is connected to the optical disk medium 9 and the RFID. By mounting in a region where the distance R from the center of the module 1 is 8.5 mm or more and 11.0 mm or less, the ring-shaped rubber stopper 18 and the plunger 17 of the player interfere with the RFID chip 5, and the media is insufficiently fixed or poorly reproduced. Can be prevented.

  9 and 10 show the RFID module 1. The adhesive material 4 is applied to the surface of the RFID module 1 provided on the base 2 and is attached to the optical disc medium 9. When the optical disk medium 9 rotates at high speed on a CD / DVD player, a dummy IC chip for correcting the deviation of the center of gravity balance by attaching the RFID module 1 or a foil in a pattern shape when forming a metal foil pattern You can leave it. The RFID module 1 is symmetrical or has a shape that allows each region to be equally divided from its center, and in each divided region where no IC is mounted, a dummy RFID chip 19 is provided in a portion corresponding to the RFID chip 5 mounting portion. Alternatively, by providing a metal foil pattern having a mass equivalent to that of the RFID chip 5, it becomes possible to reduce reading / writing errors such as CD / DVD due to eccentricity.

  FIG. 11 shows a cross section of the optical disk medium 9 on which the RFID module 1 is integrally molded with resin or the like. The RFID module 1, the reflective layer 24, and the recording layer 25 are integrally molded to prevent tag tampering. By attaching the module, it is possible to prevent the thickness of the medium from increasing and deviating from the standard.

  In particular, in an optical disk medium 9 such as a CD / DVD, a matching circuit is arranged in a very narrow metal layer-free portion 11 around a central hole surrounded by a recording surface including a metal layer, and the recording surface including the metal layer is mainly emitted. By making it function as an element, the reading performance as a tag is improved, and the matching circuit is attached to the back and front of the metal layer at an angle of 30-90 ° to each other, so that the reading directivity of the tag is biased. It is possible to provide an optical disc medium that can be read from any direction.

DESCRIPTION OF SYMBOLS 1 ... RFID module 2 ... Base material 3 ... Metal foil 4 ... Adhesive material 5 ... RFID chip 6 ... Loop circuit 7 ... First current path 8 ... First 2 current path 9 ... optical disk medium 10 ... metal layer containing part 11 ... metal layer non-containing part 12 ... media fixing hole 13 ... null point direction (unreadable direction)
14 ... RFID chip mounting part 15 ... Current induced in the metal layer of the medium 16 ... CD / DVD player disk fixing part 17 ... Plunger 18 ... Ring rubber stopper 19 ... Dummy RFID chip 20 ... metal foil pattern 21 ... label (optical disc media table)
22 ... Recording surface (back of optical disk media)
23 ... Label surface 24 ... Reflective layer 25 ... Recording layer 26 ... Resin layer H ... Thickness R ... Distance X from center ... Cross-section line

Claims (5)

  An optical disc medium surrounded by a recording surface including a metal layer and having a non-metallic area around the central hole, and an RFID module having a loop circuit in the non-metallic area on both sides of the optical disk medium An optical disc medium characterized by being shifted by an angle of 30 ° to 90 °.   2. The optical disc medium according to claim 1, wherein an IC mounting portion of the RFID module is provided within a radius of 8.5 mm to 11.0 mm from the center of the RFID module.   3. The optical disk medium surrounded by a recording surface including the metal layer and having a non-metal region around a central hole and an RFID module having the loop circuit are integrally molded. Optical disc media.   The RFID module having the loop circuit is symmetric or has a shape that allows each region to be equally divided from the center, and the mass of the target portion from the rotation center of the RFID chip mounting portion is equal to that of the dummy RFID chip or RFID chip. 4. The optical disk medium according to claim 1, wherein a metal foil pattern is provided so that the center of rotation coincides with the center of gravity.   5. The optical disc medium according to claim 1, wherein a common recognition code is recorded in each data recording area of an RFID module having a loop circuit provided on both sides of the optical disc medium. 6.