JP2004295726A - Portable information equipment and method for locking the equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the security of portable information equipment when lost by enabling the portable information equipment to be used only for a prescribed time after charging. <P>SOLUTION: This portable information equipment 1 is provided with a timer part 16 provided with a time-lapse changing part 31 and a time-lapse change confirming part 32 for measuring the time-lapse changing part 31, a timer managing part 17 for referring to the timer part 16 to determine whether or not the prescribed time has passed, and a locking part 18 for storing information for prohibiting the operation of the portable information equipment 1 and also inhibiting the operation of the self-equipment 1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a portable information device for preventing unauthorized use by a third party other than a specific user, and a method for locking the device.
[0002]
[Prior art]
BACKGROUND ART Portable terminals such as mobile phones and PDAs and frequent portable information devices such as mp3 players and digital cameras are increasing. Many of such portable information devices have become multifunctional, and accordingly, a lot of personal information has been accumulated (for example, see Patent Document 1).
[0003]
[Patent Document 1] Japanese Patent Application Laid-Open No. H11-298635
[Problems to be solved by the invention]
Recent portable information devices have accumulated a great deal of personal information, and when the portable information device is lost, damage caused by unauthorized use by a third party is increasing.
[0005]
To solve this problem, in the case of services whose use is managed by centers such as mobile phones, measures can be taken such as contacting the center when lost and disabling communication-related services on the system side. Various personal information in the terminal cannot be protected.
[0006]
Therefore, in many portable information devices, a method of locking the function of the portable information device with a password is used. However, there were problems such as the possibility of the password being released due to a brute force attack by a malicious third party who found the device, and the inability to release the lock if the user himself forgot the password. .
[0007]
As another measure, there is a mechanism to wear a transmitter separate from the main unit and lock it when the distance between the transmitter and the main unit exceeds a certain value, but if the separate transmitter itself is lost There were problems such as the inability to operate the main body.
[0008]
In addition, a portable information device driven by a built-in battery originally has the property that it cannot be operated when the battery runs out, but if a charger of the same model (or made by the same manufacturer) is used, it will be re-used. It can be charged and becomes usable.
[0009]
SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a portable electronic device that can be used only for a predetermined period after charging to improve safety in case of loss, and a method of locking the device. And
[0010]
[Means for Solving the Problems]
A portable information device according to the present invention includes a time-varying unit that changes with time without receiving power, and a time-varying confirmation unit that measures the time-varying unit to determine whether a predetermined period has elapsed and outputs the result. And timer management means for referring to the timer unit, and outputting, when the result of the determination output from the timer unit indicates that a predetermined period has elapsed, to that effect. And a lock unit for storing information for inhibiting the operation of the own device when the output from the timer management unit is obtained, and for inhibiting the operation of the own device in accordance with the stored information.
[0011]
In addition, the portable information device of the present invention includes a timer means capable of measuring a plurality of different periods by a plurality of time-varying units which change over time without obtaining power and exhibit different time-dependent changes, and a plurality of the timer means. Selecting means for selecting any of the time-varying portions, storing means for storing the selection result selected by the selecting means, and selecting the time-varying portion by referring to the contents of the storing means during period measurement. And timer management means for measuring the timer means.
[0012]
The present invention further includes a storage unit for storing information indicating operation or prohibition of the own device, and a lock unit for prohibiting operation of the own device when the stored information indicates prohibition, and obtaining power. The timer means capable of measuring a plurality of different periods by a plurality of time-varying parts that change with time and show different time-dependent changes, and when any one of the plurality of time-varying parts of the timer means is selected, the selection is made. A timer management means for storing a result, the locking method for a portable information device, comprising: When the measurement result indicates that the period has elapsed, information indicating prohibition is stored in the storage unit of the lock unit, and the lock unit prohibits the operation by this.
[0013]
In the present invention as described above, the operation of the portable information device is selectively prohibited by the timer that operates without supplying power, thereby restricting unauthorized use by a third party due to loss or the like. Now you can.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0015]
FIG. 1 shows a functional block diagram of a portable information device 1 and a charger 2 according to the present embodiment.
The portable information device 1 refers to, for example, an information device such as a notebook personal computer, a PDA, or a mobile phone that is carried by a user and can be used mainly by the user.
[0016]
The portable information device 1 includes a CPU 11, a main memory unit 12, an input unit 13, a display unit 14, and the like. In addition, the portable information device 1 includes a non-volatile storage unit 15 such as an HDD or an EEPROM, which stores various application software and secret information about an individual such as an address book, in addition to the main memory unit 12.
[0017]
The portable information device 1 changes states without constantly obtaining power, measures each state, and outputs a plurality of timer units 16-1 to 16-n capable of outputting measurement results. −1 to n, the start of measurement of the preselected timer 16-j is controlled, and the output of the timer 16-j checks whether or not a predetermined period has elapsed. Includes a timer management unit 17 that outputs a notification to that effect. Details of the timer units 16-1 to 16-n and the timer management unit 17 will be described later.
[0018]
Further, the portable information device 1 includes a lock control unit 18 that locks the portable information device so as not to operate when receiving an output indicating that a predetermined period has elapsed from the timer management unit 17.
[0019]
In addition, the portable information device 1 includes a battery unit 20 that supplies power for driving the device 1.
[0020]
Further, when the portable information device 1 is connected to the external charger 2 and charges the battery unit 20, the authentication between the authentication unit 19 in the portable information device 1 and the authentication unit 26 in the charger 2 is performed. The authentication is performed, and when the authentication is successful, the timer management unit 17 is notified. Note that any authentication method may be used as long as at least the portable information device 1 authenticates itself as a dedicated charger 2. Here, the charger 2 is dedicated to charging. However, when the user is in the office, the portable information device 1 is attached to a dedicated docking station for the device 1 and used while charging. It may be something like a dedicated docking station that is used alone.
[0021]
In addition, although not particularly shown, the portable information device 1 further includes, for example, a system that operates by constantly receiving power from the battery unit 20 and can be used by application software or the like, which is different from the timer units 16-1 to 16-n. Needless to say, it may have various functions for realizing a clock function and a function of communicating with the outside, for example.
[0022]
The CPU 11, the main memory unit 12, the input / output unit 13, the display unit 14, the storage unit 15, the timer management unit 17, and the authentication unit 19 are connected to each other via a system bus 21.
[0023]
Next, the timer units 16-1 to 16-n will be described in detail. In this description, description will be given focusing on one timer, and this timer is simply referred to as timer 16.
[0024]
FIG. 2 shows a basic configuration of the timer 16. The timer 16 includes a temporal change unit 31 and a temporal change confirmation unit 32. Here, the aging unit 31 changes its state with time without constantly supplying power, and this changed state can be used for measuring time. Upon receipt of the enable signal from the timer management unit 17, the aging check unit 32 measures the state of the aging unit 31 and outputs an elapse signal indicating whether or not a predetermined period has elapsed to the timer management unit 17. is there.
[0025]
FIG. 3 shows a time-varying unit 311 of a first specific example for realizing the time-varying unit 31.
[0026]
The time-varying portion 311 of the first specific example includes a first layer including a source region 51, a drain region 52, a channel region 53 between the source region 51 and the drain region 52, and an upper portion of the first layer. A second layer made of a tunnel insulating film 54 stacked on the third layer, a third layer made of a floating gate 55 stacked on the second layer, and an insulating film 56 stacked on the third layer. It is formed to include a fourth layer and a fifth layer including a control gate 57 stacked on the fourth layer. Further, a source electrode 58 and a drain electrode 59 are provided in the source region 51 and the drain region 52, respectively.
[0027]
FIG. 4 is a diagram showing a state change with the passage of time by the time-varying unit 311 in FIG. In the drawing, gray circles indicate electrons, white circles indicate holes, and (a) is a diagram illustrating an initial state. The aging portion 311 applies a high electric field from the control gate 57 to the floating gate 55 from the control gate 57 to the floating gate 55 through FN tunneling, and injects electrons from the channel into the floating gate 55 by FN tunneling. At this time, holes are concentrated on the substrate intervening surface of the channel region 53 and holes are concentrated, and a channel opens at the substrate interface of the channel region 53 between the source region 51 and the drain region 52.
[0028]
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 in the channel region 53 gradually decreases. (B) shows the state at time T ₁ of the after elapsed a certain time from the state of (a), (c), the time T _2, the state still is after the lapse of time from (b) shows a state, (d) shows the state at the time T ₃ after the lapse of more certain time from the state of (c). Note that the dotted line schematically shows that the electrons have moved by a direct tunnel by that time. The time T ₃ of (d) state, electrons are injected into the floating gate 55 is almost missing, the substrate interface of the channel region 53 is no longer a channel is formed, as a result, the output signal does not flow.
[0029]
FIG. 5 is a diagram showing the relationship between the time when a constant voltage is applied to such a time-varying section 311 and the current value. Time T _{a (=} 0) direct tunneling occurs between T _b from the end on the current value until the noise level channel is lost is reduced. Aging unit 311, between times T _{a (=} 0) from T _{b (=} noise level reaching time), because current corresponding to the state of the change with time flows, aging confirmation unit 32, the current It can be determined whether or not a predetermined period has elapsed based on the value. Note that T ₁ , T ₂ , and T ₃ on FIG. 5 indicate the states of (b), (c), and (d) of FIG. If the time-varying unit 311 is prepared to have different slopes of the relationship between the time and the current value, each indicates a different period. In order to make the shape different, it is only necessary to use one having a different charge amount in the initial state or a different amount per unit time of the direct tunnel.
[0030]
FIG. 6 shows a time-varying unit 312 of a second specific example that realizes the time-varying unit 31 of FIG. The time-varying portion 312 of the second specific example includes a first layer including a source region 61, a drain region 62, 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 composed of a tunnel insulating film 64 laminated on the third layer, a third layer composed of a gate 65 laminated on the second layer, and a PN junction 66 for controlling a leak current on the third layer. Formed. In the source region 61 and the drain region 62, a source electrode 68 and a drain electrode 69 are provided, respectively.
[0031]
The description of the state change of the time-varying unit 312 over time is the same as that of the first specific example by replacing the direct tunneling in the description of the time-varying unit 311 of the first specific example with the leakage current of the PN junction. Therefore, it is omitted.
[0032]
FIG. 7 shows a time-varying unit 313 of a third specific example that realizes the time-varying unit 31 of FIG. The time-varying portion 313 of the third specific example includes a first layer including a source region 71, a drain region 72, 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 composed of a tunnel insulating film 74 laminated on the second layer, a third layer composed of a gate 75 laminated on the second layer, and a Schottky junction 76 for controlling a leak current on the third layer. Are formed. Further, a source electrode 78 and a drain electrode 79 are provided in the source region 71 and the drain region 72, respectively.
[0033]
The description of the state change of the time-varying section 313 with the passage of time is the same as that of the first specific example by replacing the direct tunneling in the description of the time-varying section 311 of the first specific example with the leakage current of the PN junction. Therefore, it is omitted.
[0034]
The temporal change unit 31 (211/212/213) described in detail above is connected to the temporal change confirmation unit 32.
[0035]
Next, an example of a circuit configuration of the temporal change confirmation unit 32 will be described with reference to FIG.
[0036]
The temporal change confirming unit 32 can apply a constant voltage to both ends of the temporal change unit 31. The source electrode 58/68/78 of the aging part 31 is connected to the power supply end 81 side via the switch element 83, and the drain electrode 59 / of the aging part 31 is connected to the GND end 82 via the ammeter 84. 69/79 are connected.
[0037]
The switch element 83 is connected to the enable signal line from the timer management unit 17, and upon receiving the enable signal, the switch block 83 is turned on to conduct. The ammeter 84 measures a current value when a constant voltage is applied to the time-varying section 31, and the measured current value is input to the comparison circuit 85. On the other hand, a predetermined threshold value is input to another input of the comparison circuit 85. Note that this threshold value is the current value at the time of Tb described in FIG. The comparison circuit 85 compares the current value with the threshold value. When the current value is large, the elapsed / absence signal is Low, and when the current value is small, the elapsed / absence signal is High. The elapsed / absence signal of the comparison circuit 85 is supplied to the timer management unit 17.
[0038]
In such a circuit configuration of the aging check unit 32, when checking the state of the aging unit 31, the switch element 83 is turned on by an enable signal from the timer management unit 17, and the power supply terminal 81 and the GND terminal 82 are connected. , A current flowing through the time-varying section 31 is measured by an ammeter 84, and a progress signal indicating whether or not the measured current value exceeds a predetermined threshold is output. This makes it possible to determine whether or not a predetermined period has elapsed due to the aging of the aging unit 31.
[0039]
The basic configuration of the timer 16 shown in FIG. 2 may be realized by a modified example as shown in FIG. This modified configuration provides a timer 16 having m more time-varying portions 31 (m is a positive integer) having the same characteristics (the same predetermined period can be measured) and averaging them, thereby increasing the accuracy. The temporal change confirmation unit 33 is slightly different in configuration from the temporal change confirming unit 32 described above.
[0040]
FIG. 10 shows an example of a circuit of the temporal change checking unit 33 in this modification. In this example, the respective current values from the ammeters 84-1 to 84-m that measure the respective current values of the respective aging units 31-1 to 31-m are input to the averaging circuit 86, and the averaged current values Is compared with a threshold value by a comparison circuit 85, and a comparison result is output. With such a configuration, even if there is some variation in each of the time-dependent changes of the time-dependent changing units 31-1 to 21-m, the timer 16 can be provided as one timer 16 with higher accuracy by averaging.
[0041]
Next, the recharge unit 34 causes the time-varying unit 31 (31-1 to 31-m) to be in an initial state, in other words, causes the floating gate 55 / gate 65/75 to store electrons. That is, the recharge unit 34 applies a high electric field between the floating gate 55 / gate 65/75 and the substrate interposed surface as described above. The recharge unit 34 operates according to a signal from the timer management unit 17.
[0042]
In mounting the timer units 16-1 to 16-n of the timer 16 described above in the portable information device 1, for example, when it is desired to set each period as shown in FIG. What is necessary is just to arrange -1 to n.
[0043]
Next, the timer management unit 17 will be described with reference to FIG.
[0044]
The timer management unit 17 includes a selection timer storage unit 41 that stores information indicating the timer 16-j selected by the user via the input unit 13. Here, the description will be made assuming that a single timer 16-j is used, but different timers 16 may be selected for various functions, for example, a read function and a write function. For the sake of safety, it is desirable that the user can designate the timer 16-j only once, for example, at the time of purchase.
[0045]
In addition, the timer management unit 17 includes a timer table storage unit 42 that stores a timer table (see FIG. 13) in which the timers 16-1 to 16-n and their measurement times are associated with each other. The timer table stored in the timer table storage means 42 is read out and displayed on the display unit 14 when the user selects a timer.
[0046]
Upon receiving the authentication success signal from the authentication unit 19, the timer management unit 17 also instructs the timer units 16-1 to 16-n to restart the respective time-varying units 31 (31-1 to 31-m). Is provided. The restart instruction is notified to the recharge unit 34 in the timer 16 described above.
[0047]
In addition, the timer management unit 17 includes a timer confirmation unit 44 that confirms whether the timer 16-j has passed a predetermined period. When the power of the portable electronic device 1 is turned on, the timer checking unit 44 outputs an enable signal to the timer 16-j based on the information indicating the timer 16-j stored in the selected timer storage unit 41. , Timer 16-j. If the elapsed / presence signal from the timer 16-j indicates that a predetermined period has elapsed, the lock unit 18 is notified to that effect.
[0048]
Next, the lock section 18 will be described in detail.
[0049]
When receiving a notification from the timer management unit 17 that the predetermined period has elapsed, the lock unit 18 stores the notification in an internal storage unit (not shown) and locks the portable information device 1. Various locking methods are possible, but in this case, the operation of main devices in the portable information device 1, for example, portable information devices such as a CPU, a main memory, and a power supply unit is indispensable. A method is employed in which a disable signal is output to at least one of the devices, and the device that has received the disable signal cannot use the portable information device 1. Instead of directly supplying the disable signal to the device, a switch may be provided on a line for supplying power from the battery unit to the device, and the switch may be turned off.
[0050]
Next, each operation of the portable information device 1 according to the present embodiment described above will be described below.
[0051]
First, the selection of the timer 16-j to be used will be described with reference to FIG. This designation may be incorporated as part of the initial setting when the user purchases the portable information device 1 and turns on the power for the first time, or at any time after the purchase, but only once. You may make it possible to specify. Once specified, it is desirable that it cannot be changed.
[0052]
First, a mode setting screen of the timer section 16 is displayed (S11). Here, the user specifies the timer 16-j (S12). The screen display for designating the timer 16-j includes display contents for inquiring how many hours after the user removes the charger from the charger and a designated input area from the user. For example, a first method of displaying several selected times and selecting from them, a second method of directly inputting and specifying time, a third method of displaying a time axis and specifying an arbitrary point on the axis A method can be considered. In the case of the first method, the selected time may be acquired and used for screen display by referring to the timer table stored in the timer table storage unit 42 of the timer management unit 17, and the timer 16 corresponding to the selected time may be used. What is necessary is just to determine j as the selected timer. Further, in the case of the second method or the third method, since the contents of the timer table are not directly related to the display, the timer table may be referred to after obtaining the time designated by the user. Note that the second method and the third method do not always have a timer that matches the time specified by the user. In this case, the second method and the third method compare the measured time of each timer in the timer table and, for example, determine the closest time. It is desirable to select and present it to the user for confirmation.
[0053]
Next, information indicating the timer 16 determined by the designation is stored in the selected timer storage unit 41 of the timer management unit 17 (S13). The selection timer storage section 41 is an area that cannot be modified by the user thereafter.
[0054]
As described above, the timer 16-j used in the portable information device 1 is determined.
[0055]
Next, an operation of monitoring whether or not the portable information device 1 can be used based on the selected timer 16-j will be described. This operation may be performed when the timer management unit 17 starts the operation when the power of the portable information device 1 is turned on.
[0056]
When the operation relating to the timer monitoring is started, the timer management unit 17 reads information indicating the selected timer (= timer 16-j) stored in the selected timer storage unit 41 (S21). The timer management unit 17 outputs an enable signal to the timer 16-j based on the read information indicating the selected timer (S22).
[0057]
When the internal switch 83 is turned on by the enable signal, the aging check unit 32 (/ 33) measures the value of the current flowing through the aging unit 31 (/ 31-1 to m), compares it with the threshold value, and compares the current value with the threshold value. Is output (S23). The timer management unit 17 receives the elapsed / not present signal from the timer 16-j, and thereby obtains whether or not a predetermined period has elapsed (S24). If the predetermined period has not elapsed, the process ends without doing anything.
[0058]
On the other hand, when it is obtained that the predetermined period has elapsed, the timer management unit 18 notifies the lock unit 18 of the fact (S25). Then, the lock unit 18 stores the information and starts the lock function (S26).
[0059]
This makes it possible to disable the use of the information device after a certain period of time has passed. By using the time-varying portion here, it is possible to make the battery (battery) resistant to attacks such as resetting the timer section 16.
[0060]
Next, an operation related to the start of measurement by the timer unit 16 will be described with reference to FIG.
[0061]
When the portable information device 1 is connected to the charger 2, the battery unit 20 is charged, and at the same time, an authentication process is performed between the authentication unit 19 and the authentication unit 26 to check whether the correct charger 2 is connected. (S31). For this authentication process, any method may be used as long as at least the authentication unit 26 can authenticate the authentication unit 19 as the dedicated charger 2.
[0062]
If the authentication fails as a result of the authentication processing, the process ends without doing anything.
On the other hand, if the authentication is successful, an authentication success signal is output to the timer management unit 17 (S32).
When receiving the authentication success signal, the timer management unit 17 instructs the timer units 16-1 to 16-n to restart (S33).
As a result, the time-varying portions 31 (31-1 to 31-m) of the timers 16-1 to 16-n are set to the initial state and set as a lister (S34).
Further, the timer management unit 17 notifies the lock unit 18 to that effect (S35). As a result, if locked by the lock unit 18, the lock is released (S36, S37).
[0063]
In the present embodiment described in detail above, by limiting the time during which the device can be used, if it is lost, further use by a third party can be prevented. In addition, authentication is performed between the authentication device and the information device main body, and when the user is authenticated as a valid user, the timer unit 16 can be reset.
[0064]
【The invention's effect】
According to the present invention, since the operation of the portable information device is selectively prohibited by the timer that operates without supplying power, it is possible to restrict unauthorized use by a third party due to loss or the like. Became.
[Brief description of the drawings]
FIG. 1 is an exemplary view showing functional blocks of a portable information device 1 according to a first embodiment of the present invention.
FIG. 2 is a diagram showing a basic configuration of a timer 16;
FIG. 3 is a first specific example for realizing a time-varying unit 31;
FIG. 4 is a diagram showing a state change over time of a time-varying unit 311;
FIG. 5 is a diagram illustrating a relationship between a time and a current value when a constant voltage is applied to a time-varying unit 311.
FIG. 6 is a second specific example for realizing the basic concept of the temporal change unit 31.
FIG. 7 is a third specific example for realizing the basic concept of the aging unit 31;
FIG. 8 is a circuit configuration example of a temporal change confirmation unit 32;
FIG. 9 is a diagram showing a configuration of a timer 16 according to a modified example.
FIG. 10 is a circuit configuration example of a temporal change checking unit 23 in a modified example.
FIG. 11 shows an example of a measurement period of each of the timers 16-1 to 16-n.
FIG. 12 is a functional block diagram of a timer management unit 17;
FIG. 13 is an example of a table showing a correspondence relationship between each of timers 16-1 to 16-n, measurable elapsed time, and
FIG. 14 is a flowchart when a timer 16-j is selected from the timers 16-1 to 16-n.
FIG. 15 is a flowchart for monitoring whether or not the portable information device 1 can be used based on a selected timer 16-j.
FIG. 16 is a flowchart including an operation related to the start of measurement by the timer unit 16;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Portable information device, 2 ... Charger, 11 ... CPU
12 main memory unit, 13 input unit, 14 display unit, 15, storage unit 16, 16-1 to 16-n timer unit, 17 timer management unit 18. ··· Lock section, 19: authentication section, 20: battery section 21: system bus, 26: authentication section, 27: power supply section 31, 31-1 to 31-m, 311 , 312, 313 ... time-varying portions 32, 33 ... time-varying confirmation portions 51, 61, 71 ... source regions 52, 62, 72 ... drain regions 53, 63, 73 ... channel regions 54, 64, 74 tunnel insulating film 55 floating gate 56 insulating film 57 control gates 58, 68, 78 source electrodes 59, 69, 79 drain electrode 65 , 75 ... gate 66 ... PN junction 76 ... Power key connection 81, 81-1 to 81-m: power supply terminal 82, 82-1 to 82-m: GND terminal 83, 83-1 to 83-m: switch element 84, 84-1 to 84-m ··· ammeter 85 · · · comparison unit 86 · · · averaging circuit

Claims (5)

A time-varying part that changes with time without receiving power, and a timer means including a time-dependent change confirming unit that measures the time-varying part and determines whether or not a predetermined period has elapsed and outputs the result;
With reference to the timer unit, when the result of the determination output from the timer unit indicates that a predetermined period has elapsed, a timer management unit that outputs that fact,
When the output from the timer management unit is obtained, information for inhibiting the operation of the own device is stored, and a lock unit for inhibiting the operation of the own device according to the stored information is provided. Portable information equipment. A battery means for supplying power during operation;
Performs authentication with an external charger connected when charging the battery means, and outputs a signal indicating that the charger is compatible with the own device as a result of the authentication. Authentication means,
2. The portable information device according to claim 1, wherein said timer management means initializes a time-varying portion of said timer means when receiving a signal from said authentication means. A battery means for supplying power during operation;
Performs authentication with an external charger connected when charging the battery means, and outputs a signal indicating that the charger is compatible with the own device as a result of the authentication. Authentication means,
The timer management means, when receiving a signal from the authentication means, notifies the lock means to that effect,
The lock unit stores the stored information so as to change the stored information into information enabling the operation of the own device, and enables the operation of the own device according to the stored information. The portable information device according to claim 1. Timer means capable of measuring a plurality of different periods, respectively, by a plurality of aging units that change over time without obtaining power and indicate different aging changes,
Selecting means for selecting any of the plurality of aging units of the timer means,
Storage means for storing a selection result selected by the selection means,
A portable information device comprising: timer management means for selecting the time-varying part with reference to the contents of the storage means and measuring the timer means during period measurement. A storage unit for storing information indicating the operation or prohibition of the own device; when the stored information indicates the prohibition, the lock unit for prohibiting the operation of the own device changes with time without obtaining power, and changes with time; Timer means capable of measuring a plurality of different periods, respectively, by a plurality of time-varying portions indicating changes,
A lock method for a portable information device, comprising: when any one of the plurality of aging units of the timer means is selected, the timer management means storing a selection result thereof,
At the time of measuring the time period, the measurement result is obtained from the timer means which measures the time-varying portion according to the selection result stored in the timer management means, and when the measurement result indicates that the period has elapsed, the locking means A lock method for a portable information device, wherein information indicating prohibition is stored in a storage section of the portable information device, and the lock means prohibits the operation.

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