JP4071658B2 - Recording medium, reading device, and writing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a recording medium that can be read or written (including reading and writing) only during a predetermined period, a reading device that reads data from the recording medium, and a writing device that writes data to individual recording media.
[0002]
[Prior art]
Some conventional recording media have a write protection function for prohibiting unnecessary writing or erroneous deletion of data. For example, a 3.5-inch floppy (R) disk implements a write protection function by switching the notch at the end of the disk. Moreover, in the cassette tape, the write protection function is realized by folding the tab of the tape. The protection function by such a physical change is intended for writing, and can be freely set by the user himself, and protects against erroneous writing and erroneous deletion of data. there were.
[0003]
On the other hand, for example, there is one that records protection data in a recording area such as a CD or a DVD (see, for example, Patent Document 1). If anything, it can be set not on the user side but on the writing side that writes data to the medium, and protects the copyright of the data.
[0004]
[Patent Document 1]
Japanese Patent Application No. 2000-40298
[0005]
[Problems to be solved by the invention]
However, since protection methods such as CD and DVD are optically read and handled in the same way as normal data, there is a problem that the protection data read out by a malicious user can be modified relatively easily. there were. Moreover, settings that can be used only for a predetermined period are not possible. Note that there are known technologies that allow the content to be used only for a predetermined period. However, they record data indicating the predetermined period in the same optically treated area as the content, and the system clock on the reading device side. This is due to the comparison, and there is also a problem that if the system clock is changed by a malicious user, it can be easily used.
[0006]
Therefore, the present invention has been made in view of the above problems, and an object thereof is to provide a recording medium that is safer and can be used only for a predetermined period set by the provider. It is another object of the present invention to provide a reading device that reads data from the recording medium and a writing device that writes data to the recording medium.
[0007]
[Means for Solving the Problems]
The recording medium of the present invention includes at least a recording area where data is optically read while rotating, and a non-recording area which is different from the recording area and where data to be optically read is not recorded. The non-recording area includes an electric circuit portion and a contact portion that is exposed so as to be electrically connected to an external device and connected to the electric circuit portion.
[0008]
More preferably, the electric circuit section includes a time-varying means capable of changing with time without receiving electric power and electrically measuring the time-changed state from the outside through the contact section. desirable.
[0009]
Furthermore, it is more preferable that the electric circuit unit includes a recording unit that records unique identification information readable from the outside through the contact unit.
[0010]
The recording medium of the present invention configured as described above can set the usage period of the user with the intention of the recording medium provider side while maintaining safety.
[0011]
The present invention also provides a recording area in which optically readable data is recorded while rotating, and a non-recording area that is different from the recording area and in which optically readable data is not recorded. The non-recording area has a contact part that is exposed so as to be electrically connectable, and is connected to the contact part in order to measure the time-changed state without receiving electric power. A reading device for reading data from the recording area of the recording medium comprising a time-varying portion, and a reading means for optically reading data from the recording area of the recording medium, and a contact portion of the recording medium Measuring means for measuring the state of the time-varying portion; and determining whether or not a predetermined period has passed based on the state of the time-varying portion measured by the measuring means. And a reading device for selectively reading data in a recording area of the recording medium by the reading device according to a determination result of the determining device, wherein the electric circuit unit receives electric power. There is provided a reading device characterized by comprising time-varying means capable of being measured with time and without being able to be electrically measured from the outside via the contact portion.
[0012]
The present invention also provides a recording area in which data can be optically written while rotating, and a non-recording area that is different from the recording area and in which data cannot be optically written. The non-recording area has a contact part that is exposed so as to be electrically connectable, and is connected to the contact part in order to measure the time-changed state without receiving electric power. A writing device for writing data to the recording area of the recording medium, the writing means for optically writing the writing data to the recording area of the recording medium, and a contact portion of the recording medium Measuring means for measuring the state of the time-varying portion; and determining means for determining whether a predetermined period has passed based on the state of the time-varying portion measured by the measuring means. With the door, according to the judgment result of the judging means, to provide a writing apparatus that writes write data into the recording area of the recording medium by said writing means.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0014]
FIG. 1 shows a recording medium 1 of the present embodiment. This recording medium 1 is a partially improved CD or DVD that is an existing medium. Note that, in the case of explaining that there is no particular difference between the read medium and the read / write in the recording medium of the present embodiment, hereinafter, it is referred to as “read / write” including both read only and read / write. explain. In other words, just because “read / write” is described does not mean that read-only is excluded, or write / read is excluded.
[0015]
The recording medium 1 is generally formed in a circular shape, and a mounting hole 11 of a predetermined size for mounting on a reading / writing device 2 (described later) of the recording medium 1 is formed at the center of the mounting hole 11. A non-recording area 12 that is positioned on the outer periphery and cannot be optically read / written has a recording area 13 that is positioned on the outer periphery of the non-recording area 12 and can be optically read / written. Recently, for example, there is a rectangle that is not necessarily formed in a circular shape, but in consideration of design, this narrows the area of the recording area 13 (for example, a single size), and further optically reads the outer periphery thereof. / Only the non-recording area 12 that cannot be written is provided, and this embodiment does not exclude such a case.
[0016]
The recording area 13 is an area where data can be optically read / written, and can be read / written on the spiral from the inner circumference to the outer circumference. The recording area 13 is an area that can be used by the user, where content such as video, music, and files, attribute information, control information, and the like can be read / written. Depending on the format type of the recording medium 1, copyright information that cannot be used directly by the user on the innermost periphery of the recording area 13 but can be used by the reading / writing device 2 of the recording medium 1, Some records a unique identification number for the media. Reading of such information is also performed optically. Note that the recording medium 1 according to the present embodiment may or may not include such information.
[0017]
The non-recording area 12 is an area that cannot be optically read. Furthermore, an IC unit 14 is provided in a partial area of the non-recording area 12 of the present embodiment. FIG. 2 shows an example of the shape of the IC unit 14, and FIG. 3 shows functional blocks of the IC unit 14.
[0018]
The IC unit 14 includes an IC body 22, a sealing material 23 that seals the IC body 22, and an IC interface 21 that is electrically connected to the IC body 22 and exposed to the outside. The IC unit 14 can be formed very thin as can be seen from an IC chip or the like attached to an existing IC card. As will be described later, the IC unit 14 does not include a complicated control circuit such as a processor, and thus can be made smaller.
[0019]
The sealing material 23 including the IC main body 22 is preferably formed in such a manner that a concave portion is formed and embedded in the recording medium 1 as shown in FIG. 2 and only the IC interface 21 is exposed to the outside. It may be formed on the outer surface of the medium 1.
[0020]
The IC body 22 includes a non-volatile memory unit 26 and a time-varying unit 27, which are electrically connected to the IC interface 21, respectively. The nonvolatile memory unit 26 includes, for example, an identifier unique to the recording medium 1 and can be read from the reading / writing device 2.
[0021]
On the other hand, the time-varying unit 27 changes its state without receiving a constant power supply, and can indicate whether or not a predetermined period has elapsed. The time change unit 27 changes its state with time. The changed state is measured by the reading / writing device 2 via the IC interface 21 and used for time detection.
[0022]
A first specific example of the temporal change unit 27 will be described with reference to FIG.
[0023]
The time-varying portion 271 of the first specific example includes a source layer 51, a drain region 52, a first layer including a channel region 53 between the source region 51 and the drain region 52, and an upper portion of the first layer. The second layer is formed of a tunnel insulating film 54 stacked on the second layer, the third layer is formed of a floating gate 55 stacked on the second layer, and the insulating film 56 is stacked on the third layer. A fourth layer and a fifth layer including a control gate 57 stacked on top of the fourth layer are formed. A source electrode 58 and a drain electrode 59 are provided in the source region 51 and the drain region 52, respectively.
[0024]
FIG. 5 is a diagram showing a state change with time by the time-varying unit 271 of FIG. In the figure, gray circles indicate electrons, and white circles indicate holes.
[0025]
(A) is a figure which shows an initial state. As the pre-processing, the time-varying portion 271 performs the substrate of the channel region 53 from the control gate 57 World A high electric field is applied between the surface and the floating gate 55, and electrons are injected from the channel into the floating gate 55 by FN tunneling. At this time, the substrate of the channel region 53 World The surface is inverted to concentrate holes, and a channel opens at the substrate interface of the channel region 53 between the source region 51 and the drain region 52.
[0026]
From this state (a), as time passes, electrons in the floating gate 55 directly tunnel to the substrate interface, and the electric field at the substrate interface of the channel region 53 gradually decreases. (B) is a time T after a certain time has elapsed from the state of (a). ₁ (C) shows a time T after a certain time has elapsed from the state (b). ₂ (D) shows a time T after a certain period of time has elapsed from the state of (c). _Three Shows the state. The dotted line schematically shows that the electrons have directly moved through the tunnel by that time. Time T _Three In the state (d), most of the electrons injected into the floating gate 55 are lost, and a channel is not formed at the substrate interface of the channel region 53. As a result, no output signal flows.
[0027]
FIG. 6 is a diagram showing the relationship between the current value and time when a constant voltage is applied between the source electrode 58 and the drain electrode 59 of such a time-varying portion 271. Time T _a (= 0) to T _b Direct tunneling occurs between the two, and finally the channel disappears and the current value decreases to the noise level. The time change unit 271 displays the time T _a (= 0) to T _b (= Noise level arrival time) Since this time-dependent change is used to supply a changed current value, the side receiving this current value can determine, for example, whether or not a predetermined period has passed, When the relationship between the state of the changing unit 271 and the current value is clarified every time, the relative time from the initial state can be known. Note that T on FIG. ₁ , T ₂ , T _Three Shows the states of (b), (c), and (d) of FIG.
[0028]
FIG. 7 is a second specific example for realizing the basic concept of the time-varying unit 27 of FIG. The time-varying portion 272 of the second specific example includes a source layer 61, a drain region 62, a first layer including a channel region 63 between the source region 61 and the drain region 62, and an upper portion of the first layer. A second layer comprising a tunnel insulating film 64 laminated on the second layer, a third layer comprising a gate 65 laminated above the second layer, and a PN junction 66 for controlling a leakage current above the third layer; Formed with. A source electrode 68 and a drain electrode 69 are provided in the source region 61 and the drain region 62, respectively.
[0029]
The description of the state change with the passage of time of the time-varying unit 272 is the same as that of the first specific example if the direct tunneling in the description of the time-varying unit 271 of the first specific example is replaced with the leakage current of the PN junction. So it is omitted.
[0030]
FIG. 8 is a third specific example for realizing the basic concept of the time-varying unit 27 in FIG. The time-varying portion 273 of the third specific example includes a source layer 71, a drain region 72, a first layer including a channel region 73 between the source region 71 and the drain region 72, and an upper portion of the first layer. A second layer made of a tunnel insulating film 74 laminated on the third layer, a third layer made of a gate 75 laminated on the second layer, and a Schottky junction 76 for controlling a leakage current on the third layer. And formed with. A source electrode 78 and a drain electrode 79 are provided in the source region 71 and the drain region 72, respectively.
[0031]
The description of the state change with the passage of time of the time-varying unit 273 is the same as that of the first specific example if the direct tunneling in the description of the time-varying unit 271 of the first specific example is replaced with the leakage current of the PN junction. So it is omitted.
[0032]
The recording medium 1 includes the temporal change unit 27 as described above.
[0033]
Next, the reading / writing device 2 that uses the recording medium 1 will be described.
[0034]
FIG. 9 is a side view of the main part when the recording medium 1 is mounted on the reading / writing device 2, and FIG. 10 is an operation of the reading / writing device 2 when reading / writing the recording medium 1. It is the figure which showed the functional block of the part which concerns on.
[0035]
The rotating unit 31 is a portion to which the recording medium 1 is mounted. When reading / writing to the recording area of the recording medium 1, the recording medium 1 mounted by rotating under the control of the rotation control unit 32. Is to rotate.
[0036]
The optical pickup unit 33 optically reads / writes the recording area 13 of the recording medium 1, and is controlled by the movement control unit 34, along the slide unit 41. Data is read / written under the control of the data control unit 35 by linearly moving between them and positioned in a desired recording area. Needless to say, at least when the recording medium 1 is read / written, the optical pickup unit 33 is disposed so as to be in a good optically reading / writing distance without contacting the recording medium 1.
[0037]
The IC connection unit 36 expands under the connection control unit 37 and contacts the IC interface 21 when the recording medium 1 is loaded, and does not contact the recording medium 1 as well as the IC interface 21 otherwise. Controlled. When the IC connection unit 36 is connected to the IC interface unit 21 of the recording medium 1, the memory reading unit 38 can read the contents of the nonvolatile memory unit 26 of the IC body 22. The read (/ write) of the nonvolatile memory 26 may be read by an existing technique, and is not particularly described here.
[0038]
In addition, the IC connection unit 36 can detect the state of the temporal change unit 27 of the IC body 22 by the temporal change measurement unit 39 when the recording medium 1 is connected to the IC interface unit 21.
[0039]
The convex detection unit 40 detects a convex part provided on the recording medium 1.
[0040]
Here, a configuration example of the temporal change measurement unit 39 will be described below.
[0041]
In the example of FIG. 11, a voltage can be applied to both ends (source and drain) of the time change unit 27, and the time change unit 27 is connected to the power supply terminal 81 side via the switch element 83. Source electrode 58/68/78 is connected, and the GND end 82 side is connected to a drain electrode 59/69/79 via an ammeter 84. The switch element 83 is connected to the enable signal line and is enabled at the time of measurement, and the switch is turned on to conduct. The ammeter 84 is connected to output a current value to the comparator 85. The comparator 85 compares whether or not the input current value is greater than or equal to a predetermined threshold value.
[0042]
In such a configuration, when checking the state of the time-varying unit 27, the switch element 83 is turned on, a predetermined voltage is applied between the power supply terminal 81 and the GND terminal 82, and the current flowing through the time-varying unit 27 Is measured by the ammeter 84 and the measured current value is compared with the threshold value by the comparing unit 85, so that the time-varying measuring unit 39 can know the state of the time-varying unit 27.
[0043]
Although the above-described temporal change measuring unit 39 has been described as an example in which the recording medium 1 is provided with one temporal change unit 27, the recording medium 1 may be provided with a plurality of temporal change units 27. The time-dependent changes of the plurality of time-change parts 27 may be the same or different depending on the application. Here, a configuration example of the temporal change measuring unit 39 in the case where they are the same will be described with reference to FIG.
[0044]
In this example, a plurality of time-varying units 27 are arranged in parallel, the current values output from each are input to the averaging circuit 86, and the averaged current values are compared with a predetermined range to obtain a comparison result. It is a thing. The enable signal lines are also connected to the respective switch elements 83 and can be controlled in common. In this example, even if there is some variation in the change over time of the time change unit 27, a more stable time measurement result can be provided by averaging.
[0045]
Although a configuration example of the temporal change measuring unit 39 is not particularly illustrated here, there are advantages that various temporal information can be acquired if the temporal changes of the multiple temporal change units 27 are different. For example, as shown in FIG. 13, it can be divided into four sections, section 1, section 2, section 3, and section 4, by combinations of times t1, t2, and t3 that can be indicated by each time-varying unit 27. Various controls can be performed by allocating each section to one of the readable, writable, readable / writable, and non-readable / writable states of the recording medium. Various controls include, for example, “permit reading for a certain period of time and then allow writing for a certain period of time”, “permit reading for a certain period of time, prohibit reading for a certain period of time, and allow reading for a certain period of time”, etc. It is.
[0046]
Of course, the configuration and operation of the time-change confirming unit 39 described above may be performed by software having control equivalent to this, for example.
[0047]
Next, an example of an operation when the reading / writing device 2 reads / writes data to / from the recording medium 1 includes a mechanical operation up to connection (FIG. 14) and a reading / writing operation after connection (FIG. 15). This will be explained separately. In this example, a physical convex part is provided on one side of the IC part 14 on the non-recording area 12 of the recording medium 1, and the IC interface 21 is electrically connected with this convex part as a reference.
[0048]
First, when a read / write execution instruction is received for the recording medium 1 (S11), the connection control unit 37 controls the IC connection unit 36 to approach the medium by a predetermined distance (first stage) (S12). .
[0049]
Next, the rotation control unit 32 instructs the rotating unit 31 to perform one maximum rotation at a low speed (S13). If the convex detection part 40 added to the IC connection part 36 detects the convex part of the IC part 14 of the recording medium 1, it notifies the rotation control part 32 (S14).
[0050]
Next, the rotation control unit 32 stops the rotation unit 31 and notifies the connection control unit 37 (S15). The connection control unit 37 further extends the IC connection unit 36 (second stage). As a result, the IC connection unit 36 comes into contact with the IC interface unit 21 and is electrically connected (S16). Up to here is the mechanical operation.
[0051]
Next, the read / write operation after connection will be described with reference to FIG.
The temporal change measuring unit 39 measures the temporal change of the temporal change unit 27 of the recording medium 1 (S21), and confirms whether or not a predetermined period has passed (S22). If the result of this measurement indicates that the predetermined period has elapsed, the recording medium 1 cannot be used, so that the connection control unit 37 is notified (S23), and the connection control unit 37 sets the IC connection unit 36 to the initial state. Return to the position and finish (S24).
[0052]
If this measurement result indicates that the predetermined period has not elapsed, next, the memory reading unit 38 is notified (S25). The memory reading unit 38 reads an identifier unique to the medium recorded in the nonvolatile memory unit of the IC unit (S26). When the reading is finished, the connection control unit 37 is notified to that effect, and the connection control unit 37 returns the IC connection unit 36 to the initial position (S27).
[0053]
In the case of data reading after returning to the initial position, the data recorded in the recording area 13 is read out using the identifier read from the nonvolatile memory unit 26 as a key, and decryption processing is performed, or in the case of data writing Encrypts the data to be written using the identifier as a key and writes it to the recording area 13 (S28).
[0054]
In the above example, the recording medium 1 is newly provided with a convex portion, but the connection control to the IC interface 21 is performed using the embossed pits constituting the address signal of the recording track of the recording medium 1 in the existing DVD or the like. You may do it. In this case, the IC connection part 36 does not need to have the first stage and can be a simpler mechanism. The embossed pits of existing DVDs are described in detail in, for example, Japanese Patent Application Laid-Open No. 2002-279649.
[0055]
If the positional relationship between the emboss bit and the IC interface 21 is determined in advance, the IC connection unit 36 and the IC interface 21 are made to face each other by rotating the rotation unit 31 by an angle determined from the emboss bit. The IC interface 21 can be connected.
[0056]
Further, by providing the IC interface 21 in the mounting hole of the recording medium 1 and providing the IC connecting part 36 in the rotating part 31, the IC interface 21 and the IC connecting part when the recording medium 1 is attached to the reading / writing device 2. Since 36 is connected, a configuration in which a series of operations as shown in FIG.
[0057]
Further, in FIG. 15, the reading / writing device 2 determines whether or not to read the identifier in S <b> 22, but a configuration is also possible in which the IC unit 14 of the recording medium 1 controls whether or not the identifier can be read. That is, in the IC unit 14, when an identifier read access is made from the reading / writing device 2, the identifier can be read if the predetermined period has not elapsed, and the identifier cannot be read if the predetermined period has elapsed. To. The reading / writing device 2 can determine whether or not a predetermined period has elapsed since the identifier can be read. The subsequent operation is the same as that after S22 in FIG.
[0058]
As described above, since the recording medium 1 according to the present embodiment is provided with the IC unit 14 in the non-recording area 12, the use of the recording medium 1 can be controlled in a manner different from the reading / writing of the data in the recording area 13. Became. The IC unit 14 is provided with a time-varying unit 27 so that the usage period can be controlled in accordance with the intention of the provider of the recording medium 1. Further, the IC unit 14 also records a unique identifier. Based on the usage period control, the data is encrypted using the unique identifier as a key and recorded in the recording area 13. There is also an advantage that the data in the recording area 13 cannot be used even if a known reading / writing device different from the writing / writing device is used.
[0059]
In addition, since the reading / writing apparatus of the present embodiment can measure the time-varying portion 27 of the recording medium 1 in order to use the recording medium 1, the recording medium 1 can be used during the usable period of the recording medium 1. 1 can now be used legally.
[0060]
【The invention's effect】
As described above, according to the present invention, a recording medium that can be used only for a predetermined period set by the provider side can be provided more safely. In addition, it has become possible to provide a reading device that reads data from the recording medium and a writing device that writes data to the recording medium.
[Brief description of the drawings]
FIG. 1 is a diagram showing a recording medium 1 according to an embodiment.
FIG. 2 is a view showing an example of the shape of an IC section 14;
FIG. 3 is a diagram showing functional blocks of an IC unit 14;
FIG. 4 is a first specific example for realizing a time change unit 27;
FIG. 5 is a diagram showing a change in state with the passage of time by a temporal change unit 271;
FIG. 6 is a diagram showing the relationship between time and current value when a constant voltage is applied by the time-varying unit 271;
FIG. 7 shows a second specific example for realizing the time change unit 27;
FIG. 8 shows a third specific example for realizing the temporal change unit 27;
FIG. 9 is a side view of the main part of the reading / writing device 2 when the recording medium 1 is mounted.
FIG. 10 is a diagram showing functional blocks of a portion related to reading / writing on the recording medium 1;
FIG. 11 is a circuit configuration example of a time-change measuring unit 39;
FIG. 12 is a circuit configuration example of a time variation measuring unit 39 when a plurality of time varying units 27 are handled.
FIG. 13 is a diagram showing period segments that can be used by three time-varying units 27;
FIG. 14 is a flowchart showing mechanical operations up to connection when reading / writing to the recording medium 1 of the reading / writing device 2;
FIG. 15 is a flowchart showing a read / write operation after connection when reading / writing to the recording medium 1 of the read / write device 2;
[Explanation of symbols]
1. Recording media
2. Reading / writing device
11 ... Mounting hole
12: Non-recording area
13 ... Recording area
14 ... IC part
21 ... IC interface
22 ... IC body
23 ... Sealing material
26: Non-volatile memory unit
27 ... Time-varying part
31 ... Rotating part
32 ... Rotation control unit
33 ... Optical pickup section
34 ... Movement control unit
35 ... Data control unit
36 ... IC connection part
37 ... Connection control unit
38 ... Memory reading section
39 ... Time-change measuring part
40: Convex detector
41 ... slide part
51, 61, 71 ... source region
52, 62, 72... Drain region
53, 63, 73 ... channel region
54, 64, 74 ... Tunnel insulating film
55 ... Floating gate
56 ... Insulating film 57 ... Control gate
58, 68, 78 ... Source electrode
59, 69, 79 ... Drain electrode
65, 75 ... Gate 66 ... PN junction
76 ... Schottky junction
81 ... Power supply end
82 ... GND end
83 ... Switch element
84 ... Ammeter
85: Comparison unit
86 ... Averaging circuit

Claims (7)

At least a recording area in which data is optically read while rotating;
The recording area is different from the recording area and has a non-recording area in which data to be optically read is not recorded,
The non-recording area includes an electrical circuit portion and a contact portion that is exposed so as to be electrically connected to an external device and connected to the electrical circuit portion.
The electrical circuit section includes time-varying means capable of changing with time without receiving electric power and electrically measuring the time-changed state from the outside via the contact section. Medium.   The recording medium according to claim 1, wherein the electric circuit unit includes a recording unit that records unique identification information readable from the outside through the contact unit.   3. The recording medium according to claim 1, wherein a physical deformation is made to a position having a predetermined arrangement relationship with the contact portion in order to indicate the position of the contact portion to the external device. A non-recording area having a recording area in which optically readable data is recorded while rotating, and a non-recording area that is different from the recording area and in which optically readable data is not recorded A contact portion that is exposed so as to be electrically connectable, and a time-change portion that changes with time without receiving electric power and is connected to the contact portion to measure the time-changed state. A reading device for reading data from the recording area of a recording medium comprising:
Reading means for optically reading data from the recording area of the recording medium;
Measuring means for measuring the state of the time-varying portion via the contact portion of the recording medium;
Determining means for determining whether or not a predetermined period of time has passed based on the state of the time-varying portion measured by the measuring means;
A reading apparatus, wherein data in a recording area of the recording medium is read out by the reading unit according to a determination result of the determining unit. A non-recording area having a recording area in which optically readable data is recorded while rotating, and a non-recording area that is different from the recording area and in which optically readable data is not recorded A contact portion that is exposed so as to be electrically connectable, a time-varying portion that changes with time without receiving power, and that is connected to the contact portion to measure the time-changed state, A reading device that records unique identification information and reads data from the recording area of a recording medium including a recording unit connected to the contact unit for reading the identification information,
First reading means for optically reading data from a recording area of the recording medium;
Measuring means for measuring the state of the time-varying portion via the contact portion of the recording medium;
Second reading means for reading out the unique identification information via a contact portion of the recording medium;
Determining means for determining whether or not a predetermined period of time has passed based on the state of the time-varying portion measured by the measuring means;
According to a determination result of the determination unit, the data in the recording area read by the first reading unit is decoded with the identification information read by the second reading unit. A non-recording area having a recording area in which data can be optically written while rotating and a non-recording area that is different from the recording area and incapable of optically writing data; A contact portion that is exposed so as to be electrically connectable, and a time-change portion that changes with time without receiving electric power and is connected to the contact portion to measure the time-changed state. A writing device for writing data to the recording area of a recording medium comprising:
Writing means for optically writing write data to the recording area of the recording medium; and measuring means for measuring the state of the time-varying portion via the contact portion of the recording medium;
Determining means for determining whether or not a predetermined period of time has passed based on the state of the time-varying portion measured by the measuring means;
A writing apparatus, wherein write data is written into a recording area of the recording medium by the writing means in accordance with a judgment result of the judging means. A recording area in which data can be optically written while rotating, and a non-recording area that is different from the recording area and incapable of optically writing data; The region includes a contact portion that is exposed so as to be electrically connectable, a time-varying portion that changes with time without receiving power, and that is connected to the contact portion to measure the time-changed state. A writing device for recording unique identification information and writing data to the recording area of a recording medium comprising a recording unit connected to the contact unit for reading the identification information,
Writing means for optically writing write data to the recording area of the recording medium; and measuring means for measuring the state of the time-varying portion via the contact portion of the recording medium;
Read means for reading out the unique identification information via the contact portion of the recording medium;
Determining means for determining whether or not a predetermined period of time has passed based on the state of the time-varying portion measured by the measuring means;
A writing apparatus, wherein data is encrypted with the identification information read by the reading means, and the encrypted data is written to the recording area by the writing means in accordance with a determination result of the determining means.

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