Non-contact communication medium and recording medium cartridge

Abstract

To provide a non-contact communication medium capable of improving the power that can be extracted from an antenna and a recording medium cartridge including the medium.SOLUTION: A cartridge memory CM is a non-contact communication medium for a recording medium cartridge and comprises a circuit component 33, a support substrate 31, and an antenna coil 32. The circuit component incorporates a memory unit capable of storing management information associated with the recording medium cartridge. The support substrate supports the circuit component. The antenna coil has a coil unit electrically connected to the circuit component and formed on the support substrate, and the inductance value of the coil unit is 0.3 μH or more and 2.0 μH or less.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present technology relates to a non-contact communication medium for a recording medium cartridge and a recording medium cartridge including the same. [Background technology]

[0002] In recent years, magnetic recording media have come into wide use for purposes such as backing up electronic data. One type of magnetic recording media, for example, magnetic tape cartridges, is capable of large capacity and long-term storage, and is therefore attracting increasing attention as a storage medium for big data, etc.

[0003] For example, magnetic tape cartridges conforming to the LTO (Linear Tape Open) standard are equipped with an RFID (Radio Frequency Identification) tag called a cartridge memory (see, for example, Patent Document 1). The cartridge memory includes an antenna and an IC chip for communication and recording, and is configured to be able to read and write production management information for the magnetic tape and an overview of the recorded contents. The cartridge memory generates power by receiving a signal magnetic field transmitted from a tape drive (reader / writer), so it operates without a power source. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2009-211743 A Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, the memory size of cartridge memories has been increasing in proportion to the increase in the size of recorded data on magnetic tapes. As the memory size of cartridge memories increases, the power consumption of the cartridge memories also increases. On the other hand, this type of cartridge memory is required to operate at a certain magnetic field strength, so there is a limit to the power that can be extracted from the antenna. Therefore, there is a demand for technology that can drive the cartridge memory with the power that can be extracted from the antenna, regardless of the memory size, and ensure stable communication with the reader / writer.

[0006] In view of the above circumstances, an object of the present technology is to provide a non-contact communication medium capable of increasing the power that can be extracted from an antenna, and a recording medium cartridge including the same. [Means for solving the problem]

[0007] A non-contact communication medium according to an embodiment of the present technology is a non-contact communication medium for a recording medium cartridge, and includes a circuit component, a support substrate, and an antenna coil. The circuit component includes a built-in memory section capable of storing management information relating to the recording medium cartridge. The support substrate supports the circuit components. The antenna coil has a coil portion electrically connected to the circuit component and formed on the supporting substrate, and an inductance value of the coil portion is not less than 0.3 μH and not more than 2.0 μH.

[0008] According to the above non-contact communication medium, since the antenna coil has a coil portion with an inductance value of 0.3 μH or more and 2.0 μH or less, it is possible to increase the power that can be extracted from the antenna coil.

[0009] The coil portion may have a maximum outer diameter in the major axis direction of 20 mm or less, and a maximum outer diameter in the minor axis direction of 10 mm or less.

[0010] The inductance value of the coil portion may be not less than 0.8 μH and not more than 1.6 μH.

[0011] The antenna coil may have a Q value of 30 or greater.

[0012] The antenna coil may be made of copper foil having an average thickness of 16 μm or more.

[0013] The memory unit may include a non-volatile memory element having a memory capacity of 16 kilobytes or more.

[0014] The circuit component may further include a built-in resonant capacitance section having a variable capacitance value, electrically connected to the antenna coil.

[0015] A recording medium cartridge according to an embodiment of the present technology includes an information recording medium, a cartridge case, and a non-contact communication medium. The cartridge case accommodates the information recording medium. The non-contact communication medium includes a circuit component, a supporting substrate, and an antenna coil. The circuit component includes a built-in memory section capable of storing management information relating to the information recording medium. The support substrate supports the circuit components. The antenna coil has a coil portion electrically connected to the circuit component and formed on the supporting substrate, and an inductance value of the coil portion is not less than 0.3 μH and not more than 2.0 μH.

[0016] The information recording medium may be a magnetic tape.

[0017] The information recording medium may be a magnetic tape cartridge conforming to the LTO (Linear Tape Open) standard. Effect of the Invention

[0018] As described above, according to the present technology, it is possible to increase the power that can be extracted from the antenna. Note that the effects described herein are not necessarily limited to those described herein, and may be any of the effects described in this disclosure. [Brief description of the drawings]

[0019] [Figure 1] 1 is an exploded perspective view showing a magnetic tape cartridge according to an embodiment of the present technology; [Diagram 2] FIG. 1 is a schematic perspective view of a tape drive device. [Diagram 3] 1 is a schematic plan view showing a non-contact communication medium according to an embodiment of the present technology; [Figure 4] 11 is an experimental result showing an example of a relationship between a resonant capacitance value and an acquired current value in the non-contact communication medium. [Diagram 5] 4 is a simulation model of a resonant circuit described in an experimental example. [Figure 6] 13 is a simulation result showing the relationship between the L value of the antenna coil and the load current. [Figure 7] 11 is a simulation result showing the relationship between the L value of the coil section and the load current value when the resistance value of the load resistor is changed. [Figure 8] 11 is a simulation result showing the relationship between the L value of the coil section and the load current when the resonant capacitance value varies. [Figure 9] FIG. 9 is a graph showing the normalized results of FIG. 8. [Figure 10] FIG. 13 is a diagram showing normalized integrated power values ​​when the variation in resonant capacitance value is 0% and 17%. [Figure 11] FIG. 2 is a schematic plan view of an antenna produced in an experimental example. [Figure 12] 13 is an experimental result showing the characteristics of the above antenna together with a comparative example. [Figure 13] 13 is a simulation result showing the Q-factor dependency in the relationship between the L-factor of the antenna coil and the load current. [Figure 14] FIG. 13 is a diagram showing the relationship between the Q value and the load current value in an antenna coil with L=1.6 μH. [Figure 15]Electromagnetic simulation results showing the relationship between the thickness of the copper foil that makes up the antenna coil and the Q value. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, embodiments of the present technology will be described with reference to the drawings.

[0021] Fig. 1 is an exploded perspective view showing a magnetic tape cartridge according to an embodiment of the present technology, and Fig. 2 is a schematic perspective view of a tape drive device. In this embodiment, an LTO-standard magnetic tape cartridge (hereinafter referred to as a tape cartridge 100) shown in Fig. 1 will be described as an example of a recording medium cartridge. Below, the configurations of the tape cartridge 100 and the tape drive device 200 shown in Fig. 2 will be generally described.

[0022] [Tape cartridge] 1, the tape cartridge 100 has a cartridge case 11 that is configured by connecting an upper shell 11a and a lower shell 11b with a plurality of screw members. Inside the cartridge case 11, a single tape reel 13 around which a magnetic tape 12 is wound as an information recording medium is rotatably housed.

[0023] A chucking gear (not shown) is formed in an annular shape at the center of the bottom of the tape reel 13, and engages with a spindle 201 (see FIG. 2) of the tape drive device 200. The chucking gear is exposed to the outside through an opening 14 formed in the center of the lower shell 11b. An annular metal plate 15 that is magnetically attracted to the spindle 201 is fixed to the inner periphery of the chucking gear.

[0024] A reel spring 16, a reel lock member 17, and a spider 18 are disposed between the inner surface of the upper shell 11a and the tape reel 13. These constitute a reel lock mechanism that prevents the tape reel 13 from rotating when the tape cartridge 100 is not in use.

[0025] A tape pull-out opening 19 for pulling out one end of the magnetic tape 12 to the outside is provided on one side wall of the cartridge case 11. A slide door 20 for opening and closing the tape pull-out opening 19 is disposed inside the side wall. The slide door 20 is configured to slide in a direction to open the tape pull-out opening 19 against the biasing force of a torsion spring 21 by engaging with a tape loading mechanism (not shown) of the tape drive device 200.

[0026] A leader pin 22 is fixed to one end of the magnetic tape 12. The leader pin 22 is configured to be detachable from a pin holding portion 23 provided on the inside side of the tape pull-out opening 19. The pin holding portion 23 is equipped with elastic holders 24 that elastically hold the upper and lower ends of the leader pin 22 on the inner surface of the top wall (the inner surface of the upper shell 11a) and the inner surface of the bottom wall (the inner surface of the lower shell 11b) of the cartridge case 11, respectively.

[0027] On the inside of the other side wall of the cartridge case 21, there are disposed a safety tab 25 for preventing accidental erasure of information recorded on the magnetic tape 12, as well as a cartridge memory CM capable of contactlessly reading and writing contents related to the information recorded on the magnetic tape 12. The cartridge memory CM is constituted by a contactless communication medium having an antenna coil, an IC chip, etc. mounted on a substrate.

[0028] [Tape drive device] 2, the tape drive device 200 is configured to be capable of being loaded with a tape cartridge 100. The tape drive device 200 is configured to be capable of being loaded with one tape cartridge 100, but may be configured to be capable of being loaded with multiple tape cartridges 100 simultaneously.

[0029] The tape drive device 200 includes a spindle 201, a take-up reel 202, a spindle drive device 203, a reel drive device 204, a plurality of guide rollers 205, a head unit 206, a reader / writer 207, a control device 208, and the like.

[0030] The spindle 201 has a head portion that engages with a chucking gear of the tape reel 13 through an opening 14 formed in the lower shell 11b of the tape cartridge 100. The spindle 201 lifts the tape reel 13 a predetermined distance against the biasing force of the reel spring 16, and releases the reel lock function of the reel lock member 17. As a result, the tape reel 13 is rotatably supported inside the cartridge case 11 by the spindle 201.

[0031] The spindle drive device 203 rotates the spindle 201 in response to a command from the control device 208. The take-up reel 202 is configured to be able to fix the leading end (leader pin 22) of the magnetic tape 12 pulled out from the tape cartridge 100 via a tape loading mechanism (not shown). A plurality of guide rollers 205 guide the running of the magnetic tape 12 so that the tape path formed between the tape cartridge 100 and the take-up reel 202 has a predetermined relative positional relationship with the head unit 206. The reel drive device 204 rotates the take-up reel 202 in response to a command from the control device 208. When a data signal is recorded / reproduced on the magnetic tape 12, the spindle drive device 203 and the reel drive device 204 rotate the spindle 201 and the take-up reel 202, and the magnetic tape 12 runs.

[0032] The head unit 206 is configured to be able to record a data signal onto the magnetic tape 12 or to reproduce a data signal written onto the magnetic tape 12 in response to a command from a control device 208 .

[0033] The reader / writer 207 is configured to be able to read predetermined management information from the cartridge memory CM mounted on the tape cartridge 100 or to record predetermined management information in the cartridge memory CM in response to a command from the control device 208. As a communication method between the reader / writer 207 and the cartridge memory CM, for example, the ISO14443 method is adopted.

[0034] The control device 208 is configured by a computer including, for example, a CPU (Central Processing Unit), a storage unit, a communication unit, and the like, and performs overall control of each unit of the tape drive device 200.

[0035] [Cartridge memory] Next, the cartridge memory CM will be described in detail.

[0036] (Basic configuration) 3 is a schematic plan view showing the cartridge memory CM. The cartridge memory CM is composed of an RFID tag including a support substrate 31, an antenna coil 32, and an IC chip 33.

[0037] The support substrate 31 is made of a relatively rigid wiring substrate such as a glass epoxy substrate. The antenna coil 32 is a planar loop coil formed on the support substrate 31, and is made of copper foil, aluminum foil, or the like having a predetermined thickness. The IC chip 33 is a circuit component mounted on the support substrate 31, and is electrically connected to the antenna coil 32.

[0038] The IC chip 33 incorporates a voltage generating section which generates an activation voltage based on a signal magnetic field from the reader / writer 207 received via the antenna coil 32, a memory section which stores predetermined management information relating to the tape cartridge 100 or the magnetic tape 12, a control section which reads out information from the memory section, etc. The predetermined management information is information relating to the tape cartridge 100 in which the cartridge memory CM is mounted, such as identification information (ID) of the tape cartridge 100 or the cartridge memory CM, management information of the data recorded on the magnetic tape 12, etc.

[0039] The cartridge memory CM operates without a power source because it generates power by receiving a signal magnetic field transmitted from the reader / writer 207 with the antenna coil 32. The power supply and communication frequency from the reader / writer 207 is 13.56 MHz, the same as NFC (Near Field Communication). A non-volatile memory (NVM) is used as the memory built into the IC chip 33. The memory size is, for example, 4 kilobytes, 8 kilobytes, or 16 kilobytes, but may be larger, such as 32 kilobytes.

[0040] The memory size of the cartridge memory of the LTO standard has been increasing in proportion to the increase in the data size recorded on the magnetic tape. For example, it was 4kB in LTO-1 to LTO-3, but it is now 8kB in LTO-4 and LTO-5, and 16kB in LTO-6 and LTO-7. As the increase in the magnetic recording data size of LTO continues, it is expected that the memory size of the cartridge memory will also increase further to 16kB or more.

[0041] On the other hand, as the memory size of cartridge memory increases, the power consumption of ICs also tends to increase. In addition, power increases are expected to accompany the increase in memory size, such as an increase in the idle current of the power supply block due to the need to increase the stability of the power supply voltage supplied to the memory, and an increase in digital power due to more complex processing. Since the standard requires that the device must operate at a certain magnetic field strength, there will likely be further demands for ICs (reducing power consumption) and antennas (increasing the power drawn from the reader / writer) that can handle the increased power that accompanies increased memory size.

[0042] Furthermore, from the viewpoints of cost and reliability, the resonant frequency of this type of cartridge memory is adjusted by a capacitor built into the IC. However, the capacitance value of the IC's capacitive element varies from product to product due to variations during manufacturing. If the resonant frequency is shifted due to such individual variations, the power that can be extracted from the antenna will be reduced.

[0043] FIG. 4 shows an example of the experimental result showing the relationship between the resonant capacitance value and the obtained current value. The horizontal axis is the rate of change of the resonant capacitance value, and the resonant capacitance is set to 1.0 as the expected value (the capacitance value when the obtained current value is the highest). Therefore, when the resonant capacitance value is 1.1, it means that the resonant capacitance is 10% larger than the expected value, and when the resonant capacitance value is 0.9, it means that the resonant capacitance is 10% smaller than the expected value. The vertical axis is the current value flowing through a constant load, which corresponds to power. As shown in the figure, when the resonant capacitance value deviates from the expected value, the obtainable current (power) decreases rapidly. For example, when the resonant capacitance value varies by about 15%, the obtainable current drops to 3 / 4 of the expected value.

[0044] Note that the peak current value (1.6 mA) when the resonant capacitance is at the expected value is merely an example, and is an arbitrary value that can vary depending on the strength of the signal magnetic field transmitted from the reader / writer, as well as the inductance value of the antenna coil and the load resistance value connected to the antenna coil, as described below.

[0045] There are several possible methods for adjusting the resonance capacitance inside an IC, but in the LTO cartridge memory, a part of the non-volatile memory is used as an area for storing parameters for adjusting the resonance capacitance, making it possible to adjust the resonance capacitance without requiring additional hardware. In this case, the IC chip 33 incorporates a resonance capacitance section with a variable capacitance value that is electrically connected to the antenna coil 32. The initial capacitance value of the resonance capacitance section is measured in advance, and a set value (hereinafter referred to as a resonance capacitance set value) related to a capacitance value (expected value) that is a correct value or a difference between the measured value and the correct value is stored in the memory. Then, the resonance capacitance set value is read out at the time of startup, and the resonance capacitance value is adjusted using it as a correction parameter.

[0046] However, the power that can be obtained when the capacitance value is deviated is lower than when the resonance capacitance is at the correct value (expected value), and the power required to drive the memory tends to increase as the memory size increases. Therefore, depending on the amount of deviation in the capacitance value before adjusting the resonance capacitance and the memory size, the process of reading the resonance capacitance setting value may stop due to insufficient power, which may cause communication failure with the reader / writer.

[0047] Therefore, in the cartridge memory CM of this embodiment, in order to extract a large amount of power from a signal magnetic field of limited strength, the characteristics of the antenna coil 32 are optimized as follows, as will be described in detail below.

[0048] (Regarding inductance value) The relationship between the inductance value (hereinafter also referred to as L value) of the antenna coil and the load current was evaluated using the simulation model shown in Figure 5. The results are shown in Figure 6. In Figure 5, the resonant circuit RC is composed of a coil section 1 and a resonant capacitance 3 and a load resistance 4 connected in parallel to both ends of the coil section 1 via wiring 2. The frequency of the signal magnetic field transmitted from the reader / writer (R / W) is 13.56 MHz, the strength is 2.5 A / m, the resonant frequency of the resonant circuit RC is 13.56 MHz, and the resistance value of the load resistance 4 is 1 kΩ. In Figure 6, the horizontal axis is the L value, and the vertical axis is the load current. It can be seen from Figure 6 that the L value at which the maximum power can be obtained is approximately 0.35 μH.

[0049] Next, the relationship between the L value of the coil section 1 and the load current value when the resistance value of the load resistor 4 in the resonant circuit RC is changed is shown in FIG. 7. In the figure, the dashed line indicates the load current value when the load resistance value is 500Ω, the solid line indicates the load resistance value is 1000Ω, and the dashed line indicates the load current value when the load resistance value is 2000Ω. The increase in power due to the increase in memory size corresponds to a decrease in the load resistance value. In other words, it can be seen that the sensitivity of the L value will increase as the power increases in the future. Although it depends on the load, it can be seen that the L value that can obtain the most power is approximately 0.3μH to 0.7μH when the resonant frequency matches the signal frequency.

[0050] Next, we will consider the variation in the resonance capacitance of cartridge memory. Generally, LTO cartridge memory does not have an external capacitance due to cost and reliability considerations, and the resonance frequency is adjusted by the internal capacitance. Therefore, it is necessary to consider the characteristics when the resonance capacitance varies. Note that the resonance capacitance inside the IC depends on the process, but the variation in the resonance capacitance value is generally assumed to be about 5% to 15%, and even when considering the variation of other circuit components such as the antenna, it is assumed that there will be a maximum variation of about 17% (4.1% in terms of resonance frequency).

[0051] Figure 8 shows the relationship between the L value of the coil section 1 and the load current when the resonant capacitance value in the resonant circuit RC varies. In the figure, the solid line shows the load current value when the resonant capacitance value variation is 0% (CV=1.0), the dashed line shows the load current value when the resonant capacitance value variation is 5% (CV=1.05), the two-dot chain line shows the load current value when the resonant capacitance value variation is 10% (CV=1.10), and the dashed line shows the load current value when the resonant capacitance value variation is 17% (CV=1.17). It can be seen from the figure that if the L value is too low, the larger the variation in the resonant capacitance value, the more severe the deterioration in the obtained power tends to be. Figure 9 shows the normalized values ​​with the maximum power value when the resonant capacitance value variation is 0% and 17%, respectively.

[0052] 9, if the resonant capacitance value varies by a maximum of 17% (CV=1.17), the power is maximum when the L value is approximately 2.0 μH. From the results of FIGS. 6 to 9, in the cartridge memory CM, it is preferable that the L value of the coil portion of the antenna coil 32 is 0.3 μH or more and 2.0 μH or less.

[0053] By setting the L value to 0.3 μH or more, it is possible to maximize the obtained current when the variation in the resonant capacitance value is 0%, making it possible to obtain power very efficiently from the signal magnetic field. Also, by setting the L value to 2.0 μH or less, it is possible to extract a relatively large amount of power even when the resonant capacitance value varies. This will eliminate power shortages that may occur as memory sizes increase in the future.

[0054] Furthermore, when the normalized values ​​when the capacitance variation was 0% and 17% were integrated as an index of power efficiency from Fig. 9, the results shown in Fig. 10 were obtained. Here, the integrated value was the product of the normalized power value when the capacitance variation was 0% and the normalized power value when the capacitance variation was 17%, divided by 100. From Fig. 10, the inductance value for which the integrated value is 80% or more (rounded off to the nearest whole number) is 0.8 μH or more and 1.6 μH or less. In other words, this range is the optimal L value range when taking into account both the presence or absence of variation in the resonant capacitance value.

[0055] Based on the above-mentioned simulation results, the inventors actually fabricated an antenna and performed power evaluation. FIG. 11 shows a schematic diagram of the fabricated antenna CM1. The antenna CM1 was formed by patterning a 25 μm thick copper foil on a glass epoxy support substrate 310 having a long side of 19.9 mm and a short side of 9.95 mm to form a coil section 320 with a line width of 150 μm, a line space width of 75 μm, and a number of turns of 7. The maximum outer diameter L1 of the coil section 320 in the long axis direction was 19.0 mm, the maximum outer diameter L2 in the short axis direction was 9.0 mm, and the L value (inductance value), R value (resistance value), and Q value at 13.56 MHz were 1.255 μH, 2.575 Ω, and 41.5, respectively.

[0056] The wiring width and thickness of the coil section 320 were determined by measuring the width and thickness of 14 wirings (7 turns x 2) on the support substrate 310 when the antenna CM1 was cut in the short side direction, and taking the average value. As a measuring device, for example, a digital microscope "VHX200" manufactured by Keyence Corporation, a wide range zoom lens "VH-Z100R", etc. can be used.

[0057] The L value, R value, and Q value of the coil part 320 were measured using a network analyzer "E5071C" manufactured by Agilent Technologies. First, a calibration process was performed using an E-Cal kit (N4431-60006) manufactured by Agilent Technologies so that the physical quantity of the measurement jig (machined SMA connector and 2-pin socket) would not be reflected in the measured value. Next, the antenna CM1 was attached to the measurement jig, and the L value, R value, and Q value were measured. The average value of multiple measurements made with the network analyzer was used for each measurement.

[0058] As a comparative example, a coil part was formed on a substrate having the same shape as the support substrate 310 by patterning a 30 μm thick copper foil so that the line width was 125 μm, the line space width was 75 μm, and the number of windings (number of turns) was 12. The maximum outer diameter of the coil part in the major axis direction was 18.8 mm, the maximum outer diameter in the minor axis direction was 9.0 mm, and the L value (inductance value), R value (resistance value), and Q value at 13.56 MHz were 2.718 μH, 6.803 Ω, and 34, respectively.

[0059] The received power of the antenna samples according to the experimental example and the comparative example was evaluated. The results are shown in Figure 12. Here, a uniform magnetic field generator defined in ISO10373-6 was used to generate a constant magnetic field, and the voltage and current, i.e., the power obtained from the antenna, were measured when the load of the receiving antenna was changed. The resonant frequency was 13.56 MHz, and the magnetic field strength was 2.5 A / m.

[0060] In FIG. 12, the horizontal axis indicates the antenna end voltage (Vrms), and the vertical axis indicates the current value (mA) flowing through the load. Since the product of voltage and current is power, the measurement results located at the top right of the figure indicate greater power. Therefore, the antenna CM1 according to this experimental example can obtain greater power than the comparative example. This confirmed that the obtainable power can be increased by reducing the inductance value of the coil section 320.

[0061] (About Q value) Next, the Q value of the antenna coil will be described.

[0062] The relationship between the L value and the load current for the antenna coil's Q value is shown in Figure 13. In the figure, the solid line shows the load current value when Q is 50, the dashed line shows the load current value when Q is 40, the double-dashed line shows the load current value when Q is 30, and the dashed line shows the load current value when Q is 20. The variation in the resonant capacitance value was set to 0% for all cases. It can be seen from the figure that the higher the Q value, the greater the power that can be obtained.

[0063] Figure 14 shows the relationship between the Q factor and the load current when the L value is 1.6μH. In the figure, the horizontal axis shows the Q factor, and the vertical axis shows the load current. The current increases steeply up to a Q factor of about 30, but after that the slope becomes more gentle. From these results, it can be said that a Q factor of 30 or more is preferable because it allows a relatively large amount of power to be stably secured.

[0064] Here, the Q value of the antenna can be expressed by the following equation, where ω is the angular frequency. Q=ωL / R Since ω is constant and does not change with frequency, it is necessary to increase the L value or decrease the R value in order to increase the Q value. However, as mentioned above, the L value cannot be increased because there is an optimal value (0.3 μH or more and 1.6 μH). Therefore, it is preferable that the R value is as low as possible. Specifically, it is preferable to widen the line width of the coil part and increase the thickness. On the other hand, the antenna coil 32 of the cartridge memory CM in the LTO standard is required to have a maximum outer diameter in the major axis direction of 20 mm or less and a maximum outer diameter in the minor axis direction of 10 mm or less from the viewpoint of miniaturization, so it is difficult to widen the line width. For this reason, it is more realistic to increase the thickness of the coil part in order to improve the Q value.

[0065] Fig. 15 shows the results of an electromagnetic simulation (HFSS) of the relationship between the thickness of the coil section 320 and the Q value using the antenna CM1 produced in the above-mentioned experimental example. In the figure, the horizontal axis indicates the thickness of the coil section 320 (thickness of the copper foil), and the vertical axis indicates the Q value of the antenna CM1. It can be seen from the figure that the thickness of the copper foil and the Q value are almost proportional to each other. It was confirmed that in order to achieve the above-mentioned Q value of 30 or more, the copper foil thickness needs to be approximately 16 μm or more.

[0066] As described above, in the cartridge memory CM of this embodiment, by setting the L value of the coil part of the antenna coil to 0.3 μH or more and 1.6 μH or less, a relatively large amount of power can be extracted. In addition, it is less susceptible to the influence of variations in the resonant capacitance value, and stable power can be secured. As a result, it is possible to stably obtain power even under a limited signal magnetic field, so that it is possible to stably secure communication operations with a reader / writer, and it is also possible to fully respond to the increase in power consumption that will accompany future increases in memory size.

[0067] Although the embodiments of the present technology have been described above, the present technology is not limited to the above-described embodiments, and various modifications can be made, as a matter of course.

[0068] For example, in the above embodiment, a cartridge memory mounted on an LTO standard magnetic tape cartridge was used as an example, but this is not limited to this and the invention can also be applied to cartridge memory for magnetic tape cartridges of standards other than LTO.

[0069] The present technology can also be applied to information recording media other than magnetic tapes, such as optical disks, magneto-optical disks, semiconductor memories, and cartridge memories for portable hard disk drives.

[0070] Furthermore, this technology is not limited to cartridge memory mounted on information recording cartridges, but can also be applied to ID tags attached to electronic devices, vehicles, robots, logistics products, library collections, etc., as well as transportation commuter passes and entrance / exit management cards for highways and buildings, etc.

[0071] The present technology can also be configured as follows. (1) A non-contact communication medium for a recording medium cartridge, a circuit component having a built-in memory section capable of storing management information related to the recording medium cartridge; A support substrate for supporting the circuit components; an antenna coil having a coil portion electrically connected to the circuit component and formed on the support substrate, the coil portion having an inductance value of 0.3 μH or more and 2.0 μH or less; A non-contact communication medium comprising: (2) The non-contact communication medium according to (1), The maximum outer diameter of the coil portion in the long axis direction is 20 mm or less, and the maximum outer diameter of the coil portion in the short axis direction is 10 mm or less. Contactless communication medium. (3) The non-contact communication medium according to (1) or (2) above, The inductance value of the coil portion is 0.8 μH or more and 1.6 μH or less. Contactless communication medium. (4) The non-contact communication medium according to any one of (1) to (3) above, The Q value of the antenna coil is 30 or more. Contactless communication medium. (5) The non-contact communication medium according to any one of (1) to (4) above, The antenna coil is made of copper foil having an average thickness of 16 μm or more. Contactless communication medium. (6) The non-contact communication medium according to any one of (1) to (5) above, The memory unit includes a non-volatile memory element having a memory capacity of 16 kilobytes or more. Contactless communication medium. (7) The non-contact communication medium according to any one of (1) to (6) above, The circuit component further includes a resonant capacitance section having a variable capacitance value electrically connected to the antenna coil. Contactless communication medium. (8) an information recording medium; a cartridge case that accommodates the information recording medium; a circuit component having a built-in memory section capable of storing management information related to the information recording medium; A support substrate for supporting the circuit components; an antenna coil having a coil portion electrically connected to the circuit component and formed on the support substrate, the coil portion having an inductance value of 0.3 μH or more and 2.0 μH or less; A non-contact communication medium having A recording medium cartridge comprising: (9) The recording medium cartridge according to (8), The information recording medium is a magnetic tape. Recording medium cartridge. (10) The recording medium cartridge according to (9) above, The information recording medium is a magnetic tape cartridge conforming to the LTO (Linear Tape Open) standard. Recording medium cartridge. [Explanation of symbols]

[0072] 11...Cartridge case 12...Magnetic tape 31...Support substrate 32…Antenna coil 33...IC chip 100...Tape cartridge 200...Tape drive device CM: Cartridge memory CM1…Antenna

Claims

1. A non-contact communication medium for a recording medium cartridge, comprising: a circuit component having a built-in memory section capable of storing management information related to the recording medium cartridge; A support substrate for supporting the circuit components; a planar loop-shaped antenna coil having a coil portion electrically connected to the circuit component and formed on the support substrate, the coil portion having an inductance value of 0.8 μH or more and 1.6 μH or less; Equipped with the circuit component further includes a resonant capacitance unit having a variable capacitance value electrically connected to the antenna coil; When a power value normalized by a maximum power value obtainable by the antenna coil is defined as a normalized power value, the inductance value of the coil section is an inductance value such that the product of the normalized power value when the variation from the expected value of the resonant capacitance, which is the capacitance value with the highest obtainable current value, is 0% and the normalized power value when the variation from the expected value is 17%, divided by 100, is 80% or more, The memory unit includes a non-volatile memory element having a memory capacity of 16 kilobytes or more. Contactless communication medium.

2. The non-contact communication medium according to claim 1 , The maximum outer diameter of the coil portion in the long axis direction is 20 mm or less, and the maximum outer diameter of the coil portion in the short axis direction is 10 mm or less. Contactless communication medium.

3. The non-contact communication medium according to claim 1 or 2, The Q value of the antenna coil is 30 or more. Contactless communication medium.

4. A non-contact communication medium according to any one of claims 1 to 3, The antenna coil is made of copper foil having an average thickness of 16 μm or more. Contactless communication medium.

5. A non-contact communication medium according to any one of claims 1 to 4, The support substrate includes glass epoxy, and the antenna coil has seven turns. Contactless communication medium.

6. An information recording medium; a cartridge case that accommodates the information recording medium; A non-contact communication medium according to any one of claims 1 to 5. A recording medium cartridge comprising:

7. 7. The recording medium cartridge according to claim 6, The information recording medium is a magnetic tape. Recording medium cartridge.

8. 8. The recording medium cartridge according to claim 7, The information recording medium is a magnetic tape cartridge conforming to the LTO (Linear Tape Open) standard. Recording medium cartridge.

9. A recording medium cartridge according to any one of claims 6 to 8, The management information related to the recording medium cartridge is identification information of the non-contact communication medium. Recording medium cartridge.

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