Abstract:
A method of controlling a computer managing user&#39;s schedule is disclosed. The method includes the steps of: setting a first time; determining whether present time is within the first time before a going-out time at which the user is to go out; and setting the computer at a going-out mode in response to the determination. The method may further include the steps of: setting a second time; determining whether the present time is within the second time before the going-out time; controlling a power supply of the computer; wherein after the computer is set in the going-out mode, the power supply is turned off in response to the determination. The method enables the computer to control the power supply based on the state of the user and the user&#39;s schedule managed thereby.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention generally relates to a method of controlling a computer, and more particularly, to a method of controlling a computer that manages user&#39;s schedule, the computer having a user detection unit for detecting the user.  
           [0003]    2. Description of the Related Art  
           [0004]    Computers are often used for managing personal schedules of users. The user&#39;s schedule is input into the computer and is stored therein. The computer may display a message or sound alarm at a certain time prior to an appointment, for example, for letting the user know that it is time to prepare for the appointment.  
           [0005]    As described above, the computer can perform a predetermined operation (displaying a message or sounding an alarm) in accordance with the input schedule. The computer can even turn itself on and off at a predetermined time designated by the user. The computer follows the schedule designated by the user in this case.  
           [0006]    The following documents disclose related art: Japanese Laid-Open Patent Applications No. 11-272920 and No. 57-36326.  
           [0007]    The computer according to the related art, however, merely follows the schedule designated by the user. Even if the user&#39;s actual schedule has been changed, the- computer follows the designated schedule until the user changes it.  
         SUMMARY OF THE INVENTION  
         [0008]    Accordingly, it is a general object of the present invention to provide a novel and useful method of controlling a computer in which one or more of the problems described above are eliminated.  
           [0009]    Another and more specific object of the present invention is to provide a method of controlling the power supply of a computer that manages user&#39;s schedule, the computer provided with a user detection device, to provide a computer that performs the method, and to provide a computer program that causes the computer to perform the method.  
           [0010]    To achieve one or more of the above objects, a method of controlling a computer that manages user&#39;s schedule, according to the present invention, includes the steps of:  
           [0011]    setting a first time;  
           [0012]    determining whether a present time is within the first time before a going-out time at which the user is to go out; and  
           [0013]    setting the computer in an going-out mode in response to a determination that the present time is within the first time before the going-out time.  
           [0014]    According to the present invention, the method as described above further includes the steps of:  
           [0015]    setting a second time;  
           [0016]    determining whether the present time is within the second time before the going-out time;  
           [0017]    controlling a power supply of the computer;  
           [0018]    after the computer is set at the going-out mode, turning the power supply off in response to the determination that the present time is within the second time before the going-out time.  
           [0019]    The method according to the present invention enables the computer to control the power supply thereof based on the state of the user and the user&#39;s schedule managed thereby. According to these arrangements, the computer becomes more useful.  
           [0020]    Other objects, features, and advantages of the present invention will be more apparent from the following detailed description when read in conjunction with the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]    [0021]FIG. 1 is a block diagram showing a computer to which a method according to a first embodiment of the present invention is applied;  
         [0022]    [0022]FIG. 2 is a chart showing the state transition of the method according to the first embodiment;  
         [0023]    [0023]FIG. 3 is a flowchart showing the operation of the method according to the first embodiment;  
         [0024]    [0024]FIG. 4 is a chart showing the state transition of a method according to a second embodiment;  
         [0025]    [0025]FIG. 5 is a flowchart showing the operation of the method according to the second embodiment;  
         [0026]    [0026]FIG. 6 is a schematic diagram showing a computer according to the second embodiment;  
         [0027]    [0027]FIG. 7 is an exemplary screen showing a schedule displayed by a schedule manager according to an embodiment;  
         [0028]    [0028]FIG. 8 is a flowchart showing the operation of the computer according to the second embodiment;  
         [0029]    [0029]FIG. 9 is a schematic diagram showing a computer according to a third embodiment;  
         [0030]    [0030]FIG. 10 is a flowchart showing the operation of the computer according to the third embodiment;  
         [0031]    [0031]FIG. 11 is a schematic diagram showing a computer according to a fourth embodiment; and  
         [0032]    [0032]FIG. 12 is a flowchart showing the operation of the computer according to the fourth embodiment. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0033]    A detailed description of the preferred embodiments according to the present invention is given below with reference to the drawings.  
         [0034]    [0034]FIGS. 1 through 3 show a first embodiment of the present invention. FIG. 1 is a block diagram showing a computer according to the first embodiment. FIG. 2 is a chart showing the state transition of the computer according to the first embodiment. FIG. 3 is a flowchart showing the operation of the computer according to the first embodiment.  
         [0035]    The computer (system)  100  shown in FIG. 1 includes a computer (processing unit)  101 , a user detection device  102 , a monitor  106 , and an input device  107  such as a keyboard. An operating system (OS)  103  is executed on the computer  101 , and a schedule manager (software)  104  is executed under the control of the operating system  103 . The computer  101  includes a power supply  105 . The operating system  103  can control the power supply  105 .  
         [0036]    The user detection device  102  determines whether the user is around the computer  101 . When the user leaves from the computer  101  (distant from the computer  101  by more than a predetermined distance), the user detection device  102  informs the computer  101  that the user is not around the computer  101 . When the user approaches the computer  101  (distant from the computer  101  by less than the predetermined distance), the user detection device  102  informs the computer  101  that the user is around the computer  101 .  
         [0037]    The schedule manager (software)  104  stores and manages the user&#39;s personal schedule. If the user needs to go out for an appointment, for example, the item of the schedule (the appointment) is identified by a flag.  
         [0038]    The following symbols are referred to in the description given below.  
         [0039]    “TA” denotes the time at which an appointment begins. “TX” denotes the time period after a message or an alarm is given and before the appointment begins. The message or alarm is given at time “TA-TX”. “TY” denotes the time period after the power supply of the computer is turned off and before an appointment begins. “TX” is longer than “TY” (TX&gt;TY). “t” denotes the present time.  
         [0040]    “Mwork” denotes a state in which the computer  101  operates normally. “Mout” denotes a state in which the computer  101  knows that the user has gone out, for example. “m” denotes the present state of the computer  101 . “Pon” denotes a state in which the power supply  105  is turned on. “Poff” denotes a state in which the power supply  105  is turned off. “p” denotes the present state of the power supply  105 . “Z” denotes an operation related to the time “t=TA-TX”. And, “z” is set to 0 if no operation is related by the user, and is set to Z if the operation “Z” is related by the user, for example.  
         [0041]    A state (m=Mout) in which the computer  101  knows (is informed) that the user has gone out is referred to as an going-out mode. The computer  101  performs predetermined operations described below.  
         [0042]    Referring to FIGS. 2 and 3, a first embodiment is described. FIGS. 2 and 3 show the operation in which the power supply  105  is controlled without the user detection device  102  being used.  
         [0043]    [0043]FIG. 2 shows a state transition chart of both the power supply  105  and the schedule manager  104 . The state transition chart includes five states  210 ,  220 ,  230 ,  240 , and  250 .  
         [0044]    In the state  210 , the power supply  105  is on, and the computer  101  operates normally.  
         [0045]    In the state  220 , the message is sent or the alarm is sounded prior to an item of schedule.  
         [0046]    In the state  230 , the operation “Z” related by the user is performed.  
         [0047]    In the state  240 , the power supply  105  is on, and the computer  101  knows that the user has gone out.  
         [0048]    In the state  250 , the power supply  105  is off, and the computer  101  knows that the user has gone out.  
         [0049]    Each transition from one state to another is indicated by an arrow  211 ,  212 ,  221 ,  222 ,  231 ,  241 , and  251 .  
         [0050]    [0050]FIG. 3 is a flowchart showing the operation of the computer  101 , the states of which transit as shown in FIG. 2. The operation according to the present embodiment is described below with reference to FIGS. 2 and 3.  
         [0051]    In step  301 , the power supply  105  is turned on. The process proceeds to step  302 . The flow from step  301  to step  302  shown in FIG. 3 corresponds to the transition  251  from the state  250  to the state  210  shown in FIG. 2.  
         [0052]    In step  302 , the power supply  105  is on, and the computer  101  operates normally. Step  302  shown in FIG. 3 corresponds to the state  210  shown in FIG. 2.  
         [0053]    In step  303 , a determination is made of whether “t” is equal to “TA-TX.” If the determination is made that “t” is equal to “TA-TX”, the process proceeds to step  310 . The flow from step  303  to step  310  shown in FIG. 3 corresponds to the transition  211  from the state  210  to the state  220  shown in FIG. 2.  
         [0054]    In step  310 , a determination of whether z=0 is made. If z=0, the process proceeds to step  302 . The flow from step  310  to step  302  shown in FIG. 3 corresponds to the transition  221  from the state  220  to the state  210  shown in FIG. 2. If z is not equal to 0, the process proceeds to step  311 .  
         [0055]    In step  311 , an alarm is sounded or a message is sent. Step  311  corresponds to the state  220  shown in FIG. 2. The process proceeds to step  312 . The flow from step  311  to step  312  corresponds to the transition  222  from the state  220  to the state  230  shown in FIG. 2. As described above, when the present time “t” becomes equal to “TA-TX”, and if z=0, the schedule manager (software)  104  displays a message or sounds an alarm to inform the user that the time (of the item of schedule) is coming.  
         [0056]    In step  312 , the operation Z related by the user is performed. That is, when the present time “t” is equal to “TA-TX”, if “z” is set at “z=Z”, the operation “Z” is performed. The process then proceeds to step  302 . The flow from step  312  to step  302  corresponds to the transition  231  from the state  230  to the state  210  shown in FIG. 2.  
         [0057]    If a determination is made that “t” is not equal to “TA-TX” in step  303 , the process proceeds to step  304 . In step  304 , a determination is made as to whether the present time “t” is greater (later) than “TA-TX”. If “t” is not greater than “TA-TX”, the process returns to step  302 , and the steps described above are repeated. If a determination is made that “t” is greater than “TA-TX”, the process proceeds to step  305 . The flow from step  304  to step  305  corresponds to the transition  212  from the state  210  to the state  240  shown in FIG. 2.  
         [0058]    In step  305 , the power supply  105  remains on, and the computer  101  learns (determines) that the user has gone out. As described above, if the computer determines that the present time “t” is greater than “TA-TX”, the state of the computer  101  transits from “m=Mwork” to “m=Mout” (corresponding to the state  240  shown in FIG. 2). The process proceeds to step  306 .  
         [0059]    In step  306 , a determination is made of whether “t” is greater (later) than “TA-TY”. If the determination is made that “t” is not greater than “TA-TY”, the process proceeds to step  305 , and repeats step  305  until the determination is made that “t” is greater than “TA-TY”. If the determination is made that “t” is greater than “TA-TY”, the process returns to step  307 . The flow from step  306  to step  307  corresponds to the transition  241  from the state  240  to the state  250  shown in FIG. 2.  
         [0060]    In step  307 , the power supply  105  is turned off, and the computer  101  knows that the user has gone out. Step  307  corresponds to the state  250  shown in FIG. 2. As described above, when the present time “t” becomes greater than “TA-TY”, the state of the power supply  105  of the computer  101  transits from a state of P=Pon to that of P=Poff.  
         [0061]    Finally, the process proceeds to step  308 . The power supply  105  of the computer  101  remains turned off.  
         [0062]    A second embodiment of the present invention is described with reference to FIGS. 1, 4, and  5 . As described above, FIG. 1 is the block diagram showing the computer (system)  100  according to the first embodiment. The structure of the computer system according to the second embodiment is basically the same as that of the first embodiment, and accordingly FIG. 1 is referred to. FIG. 4 is a chart showing the state transition of the computer  101  according to the second embodiment. FIG. 5 is a flowchart showing the operation of the computer  101  according to the second embodiment.  
         [0063]    The symbols used in FIGS. 4 and 5 are the same as those used in FIGS. 2 and 3.  
         [0064]    In addition to the above, the following symbols may be used in FIGS. 4 and 5. “Don” and “Doff” denote a state in which the user detection device  102  detects that there is a user and a state in which the user detection device  102  detects that there is not a user, respectively. “d” denotes information that the user detection device  102  provides to the computer  101 . “Min” denotes a state in which the schedule manager  104  understands that the user has stepped out but has not gone out. The state in which the schedule manager  104  understands that the user has stepped out (m=Min) is referred to as a stepping-out mode. The computer  101  performs a predetermined operation as described above in the stepping-out mode. “c=AutoOn” denotes a setting designated by the user in which the computer  101  is automatically turned off while the user has gone out. “c=AutoOff” denotes a setting designated by the user in which the computer  101  does not automatically turn off (that is, the computer does nothing) while the user has gone out.  
         [0065]    The operation of the computer  101  according to the second embodiment is described with reference to FIGS. 4 and 5. The computer  101  controls the power supply provided therein depending on the determination, using the user detection device  102 , of whether the user is around.  
         [0066]    [0066]FIG. 4 shows a state transition chart of both the power supply  105  and the schedule manager  104 . The state transition chart includes six states  410 ,  420 ,  430 ,  440 ,  450 , and  460 .  
         [0067]    In the state  410 , the power supply  105  is on, and the computer  101  operates normally.  
         [0068]    In the state  420 , the message is sent or the alarm is sounded prior to an item of schedule.  
         [0069]    In the state  430 , the operation “Z” related by the user is performed.  
         [0070]    In the state  440 , the power supply  105  is on, and the computer  101  knows that the user has gone out.  
         [0071]    In the state  450 , the power supply  105  is off, and the computer  101  knows that the user has gone out.  
         [0072]    In the state  460 , the power supply  105  is on, and the schedule manager  104  knows that the user has stepped out.  
         [0073]    Each transition from one state to another is indicated by an arrow  411 ,  412 ,  421 ,  422 ,  431 ,  441 ,  451 ,  461 , and  462 .  
         [0074]    [0074]FIG. 5 is a flowchart showing the operation of the computer  101 , the states of which transit as shown in FIG. 4. The operation according to the present embodiment is described below with reference to FIGS. 4 and 5.  
         [0075]    In step  501 , the power supply  105  is turned on. The process proceeds to step  502 . The flow from step  501  to step  502  shown in FIG. 5 corresponds to the transition  451  from the state  450  to the state  410  shown in FIG. 4.  
         [0076]    In step  502 , the power supply  105  is on, and the computer  101  operates normally. Step  502  shown in FIG. 5 corresponds to the state  410  shown in FIG. 4.  
         [0077]    In step  503 , a determination is made as to whether “t” is equal to “TA-TX.” If the determination is made that “t” is equal to “TA-TX”, the process proceeds to step  511 . The flow from step  503  to step  511  shown in FIG. 5 corresponds to the transition  411  from the state  410  to the state  420  shown in FIG. 4.  
         [0078]    In step  511 , a determination of whether z=0 is made. If z=0, the process proceeds to step  502 . The flow from step  511  to step  502  shown in FIG. 5 corresponds to the transition  421  from the state  420  to the state  410  shown in FIG. 4. If z is not equal to 0, the process proceeds to step  512 .  
         [0079]    In step  512 , the message is sent or the alarm is sounded. Step  512  corresponds to the state  420  shown in FIG. 4. The process proceeds to step  513 . The flow from step  512  to step  513  corresponds to the transition  422  from the state  420  to the state  430  shown in FIG. 4. In the case in which d=Don (a state in which the user detection device  102  detects the user), when the present time “t” becomes equal to “TA-TX”, and if z=0, the schedule manager (software)  104  displays a message or sounds the alarm to inform the user that the time (of the item of schedule) is coming.  
         [0080]    In step  513 , the operation Z related by the user is performed. That is, when the present time “t” is equal to “TA-TX”, if “z” is set at “z=Z”, the operation “Z” is performed. The process then proceeds to step  502 . The flow from step  513  to step  502  corresponds to the transition  431  from the state  430  to the state  410  shown in FIG. 4.  
         [0081]    If a determination is made that “t” is not equal to “TA-TX” in step  503 , the process proceeds to step  504 .  
         [0082]    In step  504 , a determination is made as to whether the user detection device  102  detects that there is a user. If the determination is made that the user detection device  102  detects a user (d=Don), the process returns to step  502 , and repeats the above steps. If the determination is made that the user detection device  102  detects that there is no user (d=Doff), the process proceeds to step  505 .  
         [0083]    In step  505 , a determination is made as to whether the present time “t” is greater (later) than “TA-TX”. If a determination is made that “t” is greater than “TA-TX”, the process proceeds to step  506 . The flow from step  505  to step  506  corresponds to the transition  412  from the state  410  to the state  440  shown in FIG. 4.  
         [0084]    In step  506 , the power supply  105  remains on, and the computer  101  learns (determines) that the user has gone out. If the user has gone out in response to the message or the alarm sounded in step  512 , for example, the user detection device  102  determines that the state of the user has changed. The user detection device  102  informs the computer  101  of the state d=Doff. If the computer determines that the present time “t” is greater than “TA-TX”, the state of the computer  101  transits from “m=Mwork” to “m=Mout” (corresponding to the state  440  shown in FIG. 4). The process proceeds to step  507 .  
         [0085]    In step  507 , a determination is made of whether the user detection device  102  detects that there is a user. If the determination is made that the user detection device  102  detects a user (d=Don) in step  507 , the process returns to step  502 , and repeats the above steps. The flow from step  507  to step  502  corresponds to the transition  442  from the state  440  to the state  410  in FIG. 4. If the determination is made in step  507  that the user detection device  102  detects that there is no user (d=Doff), the process proceeds to step  508 .  
         [0086]    In step  508 , a determination is made as to whether “t” is greater (later) than “TA-TY”. If the determination is made that “t” is not greater than “TA-TY”, the process returns to step  506 , and repeats steps  506  and  507  until the determination is made that “t” is greater than “TA-TY”. If the determination is made that “t” is greater than “TA-TY”, the process proceeds to step  509 . The flow from step  508  to step  509  corresponds to the transition  441  from the state  440  to the state  450  shown in FIG. 4.  
         [0087]    In step  509 , the power supply  105  is turned off, and the computer  101  knows that the user has gone out. Step  509  corresponds to the state  450  shown in FIG. 4. As described above, when the present time “t” becomes greater than “TA-TY”, the state of the power supply  105  of the computer  101  transits from a state of P=Pon to that of P=Poff.  
         [0088]    Finally, the process proceeds to step  510 . The power supply  105  of the computer  101  remains turned off.  
         [0089]    If a determination is made in step  505  that the present time “t” is not greater than “TA-TX”, the process proceeds to step  514 . The state of the schedule manager  104  is changed from m=Mwork to m=Min. The flow from step  505  to step  514  corresponds to the transition  413  from the state  410  to the state  460 .  
         [0090]    In step  514 , the power supply  105  is on and the schedule manager  104  knows that the user has stepped out, instead of having gone out. Step  514  corresponds to the state  460  shown in FIG. 4.  
         [0091]    In step  515 , a determination is made of whether the user detection device  102  has been detecting a user. If the determination is made that the user detection device  102  has been detecting a user (d=Don), the process returns to step  502  for repeating steps starting with step  502 . The flow from step  507  to step  502  corresponds to the transition  462  from the state  460  to the state  410  shown in FIG. 4. If the determination is made in step  515  that the user detection unit  102  has been detecting no user (d=Doff), the process proceeds to step  516 .  
         [0092]    In step  516 , a determination is made as to whether “t” is greater than “TA-TY”. If a determination is made that “t” is not greater than “TA-TY”, the process returns to step  514 , and steps  514  and  515  are repeated. If a determination is made that “t” is greater than “TA-TY”, the process proceeds to step  517 .  
         [0093]    In step  517 , a determination is made as to whether the user has set the computer  101  so that, when the user is not around the computer  101 , the computer  101  is automatically turned off (as described above, the setting is referred to as c=AutoOn if the computer  101  is to automatically turn off, and c=AutoOff if the computer  101  is not to automatically turn off). If the computer is not set to c=AutoOn (c=AutoOff), the process returns to step  514  without executing any step. That is, when m=Min, and the present time “t” is greater than “TA-TY”, the computer  101  remains in the state m=Min and p=Pon as set by the user. In other words, if c=AutoOn, then when the present time “t” becomes greater than “TA-TY” regardless of “m”, the state of the power supply  105  is turned to p=Poff. If c=AutoOff, the state at time “t” being less than “TA-TY” is maintained.  
         [0094]    On the other hand, if c=AutoOn, the process proceeds to step  509 . Steps  509  and  510  are executed.  
         [0095]    In step  509 , since d=Doff, and the present time “t” is greater than “TA-TY”, the state of the computer  101  transits from p=Pon to p=Poff. The flow from step  517  to step  509  corresponds to the transition  461  from the state  460  to the state  450  shown in FIG. 4.  
         [0096]    A third embodiment of the present invention is described with reference to FIGS. 6, 7, and  8 . FIG. 6 is a schematic diagram showing a computer system  600  according to the third embodiment. Elements identical to those shown in FIG. 1 are referred to by the same reference numerals, and their description is omitted. FIG. 8 is a flowchart showing the operation of the computer  101  according to the third embodiment.  
         [0097]    The computer system  600  shown in FIG. 6 includes a computer (processing unit)  101 , the operating system  103 , the schedule manager (software)  104 , a keyboard  601  connected to the computer  101 , and a monitor  602  connected to the computer  101 . A schedule window  603  is shown on the screen of the monitor  602  by the schedule manager  104  running on the computer  101 . FIG. 7 is a schematic diagram showing the schedule window  603 .  
         [0098]    The exemplary schedule  603  shown in FIG. 7 indicates that the next item of schedule starts at 14:00 (“TA” is 14:00), and the alarm is set at 30 minutes prior to “TA” (“TX” is 30 minutes). The power supply of the computer  101  is to be turned off at 5 minutes prior to “TA” (“TY” is 5 minutes). “t” indicates the present time. “Mwork” denotes a state in which the computer  101  operates normally. “Mout” denotes a state in which the computer  101  knows that the user has gone out, for example. “m” denotes the present state of the computer  101 . “Pon” denotes a state in which the power supply  105  is turned on. “Poff” denotes a state in which the power supply  105  is turned off. “p” denotes the present state of the power supply  105 . “Z” denotes an operation related to the time “t=TA-TX”. And, “z” denotes the state of a setting. In this case, “Z” is an operation in which a message “It&#39;s time to leave.” is displayed.  
         [0099]    In step  801  shown in FIG. 8, the computer  101  is turned on. The process proceeds to step  802 .  
         [0100]    In step  802 , the power supply  105  is on, and the computer  101  operates normally.  
         [0101]    In step  803 , a determination is made as to whether “t” is equal to 13:30. If a determination is made that “t” is equal to 13:30, the process proceeds to step  810 .  
         [0102]    In step  810 , a determination is made as to whether “z=0”. Since an operation is related to “Z”, “z” is not equal to 0. The process proceeds to step  811 .  
         [0103]    In step  811 , the alarm is sounded (or a message is sent), and the process proceeds to step  812 . According to these arrangements, when the present time “t” comes to 13:30, the schedule manager  104  can indicate the message or sound the alarm so as to inform the user that time is coming.  
         [0104]    In step  812 , the operation “Z” related by the user is performed. That is, the message “It&#39;s time to leave.” is displayed at “t=13:30”. The process then proceeds to step  802 .  
         [0105]    In step  803 , if a determination is made that “t” is not equal to  13 : 30 , the process proceeds to step  804 . In step  804 , a determination is made of whether the present time “t” is greater than 13:30. If the present time “t” is not greater than 13:30, the process returns to step  802 , and steps  802  and  803  are repeated. If a determination is made that “t” is greater than 13:30, the process proceeds to step  805 .  
         [0106]    In step  805 , the power supply  105  of the computer  101  is on, and the computer  101  knows that the user has gone out. The computer  101  moves from the state m=Mwork to the state m=Mout in response to determination that the present time “t” is greater than  13 : 30 . The process proceeds to step  806 .  
         [0107]    In step  806 , a determination is made of whether “t” is greater than 13:55. If a determination is made that “t” is not greater than 13:55, the process returns to step  805 , and repeats step  805 . If a determination is made that “t” is greater than 13:55, the process proceeds to step  807 .  
         [0108]    In step  807 , the computer knows that the power supply  105  is turned off, and the user has gone out. When the present time “t” becomes greater (later) than 13:55, the power supply  105  of the computer  101  transits from the state P=Pon to the state P=Poff.  
         [0109]    Finally, the process proceeds to step  808 , and the power supply  105  of the computer  101  remains turned off.  
         [0110]    A fourth embodiment of the present invention is described with reference to FIGS. 9 and 10. FIG. 9 is a schematic diagram showing a computer system  900  according to the fourth embodiment. Elements identical to those shown in the previous drawings are referred to by the same reference numerals, and their description is omitted. FIG. 10 is a flowchart showing the operation of the computer  101  according to the fourth embodiment.  
         [0111]    The computer system  900  shown in FIG. 9 includes the computer (processing unit)  101 , the operating system  103 , the schedule manager (software)  104 , the keyboard  601  connected to the computer  101 , the monitor  602  connected to the computer  101 , an IC card reader/writer  901 , an IC card  902 , and a personal data assistant (PDA)  903 . The IC card reader/writer  901  and the IC card constitute the user detection device  102  shown in FIG. 1. The IC card reader/writer  901  and the IC card  902 , that is, the user detection device  102 , determines that the user is around the computer  101  by determining whether the IC card  902  is set in the IC card reader/writer  901 .  
         [0112]    In the exemplary embodiment, the user is required to set (insert into and connect to) the IC card in the IC card reader/writer  901  while the user has stepped out. The IC card reader/writer  901  informs the computer  101  that the IC card is set therein (that is, the user has stepped out). The user uses the PDA  903  in addition to the computer system  900 . The PDA  903  can exchange data with the computer  101  via a wireless channel  904 .  
         [0113]    The schedule manager  104  running on the computer  101  displays the schedule window  603  on the monitor  602 . An operation “copying a file F to PDA  903 ” is set as “Z”.  
         [0114]    In step  1001  shown in FIG. 10, the power supply  105  is turned on. The process proceeds to step  1002 .  
         [0115]    In step  1002 , the power supply  105  is on, and the computer  101  operates normally.  
         [0116]    In step  1003 , a determination is made whether “t” is equal to 13:30. If the determination is made that “t” is equal to 13:30, the process proceeds to step  1011 .  
         [0117]    In step  1011 , a determination of whether z=0 is made. Since an operation is set at “Z”, and as a result, z is not equal to 0, the process proceeds to step  1012 .  
         [0118]    In step  1012 , the message is sent and/or the alarm is sounded, and the process proceeds to step  1013 . As described above, in the case in which d=Don (a state in which the user detection device  102  detects the user), when the present time “t” becomes equal to 13:30, and if z=0, the schedule manager (software)  104  displays a message or sounds the alarm to inform the user that the time (of the item of schedule) is coming.  
         [0119]    In step  1013 , the operation Z related by the user is performed. That is, when the present time “t” is equal to 13:30, since “z” is set at “z=Z”, the operation in which the file F is copied to the PDF  903  is performed. The process then proceeds to step  1002 .  
         [0120]    If a determination is made that “t” is not equal to 13:30 in step  1003 , the process proceeds to step  1004 .  
         [0121]    In step  1004 , a determination is made of whether the IC card  902  is set in the IC card reader/writer  901 . If the determination is made that the IC card  902  is set in the IC card reader/writer  901  (d=Don), the process returns to step  1002 , and repeats the above steps. If the determination is made that the IC card  902  is not set in the IC card reader/writer  901  (d=Doff), the process proceeds to step  1005 .  
         [0122]    In step  1005 , a determination is made whether the present time “t” is greater (later) than 13:30. If a determination is made that “t” is greater than 13:30, the process proceeds to step  1006 .  
         [0123]    In step  1006 , the power supply  105  is on, and the computer  101  learns (determines) that the user has gone out. If the user has gone out in response to the message or the alarm sounded in step  1012 , for example, the IC card reader/writer  901  determines that the state of the user has changed. The IC card reader/writer  901  informs the computer  101  of the state d=Doff. If the computer determines that the present time “t” is greater than 13:30, the computer  101  transits from the state “m=Mwork” to the state “m=Mout”. The process proceeds to step  1007 .  
         [0124]    In step  1007 , a determination is made of whether the IC card  902  is set in the IC card reader/writer  901 . If the determination is made that the IC card  902  is set in the IC card reader/writer  901  (d=Don) in step  1007 , the process returns to step  1002 , and repeats the above steps. If the determination is made in step  1007  that the IC card  902  is not set in the IC card reader/writer  901  (d=Doff), the process proceeds to step  1008 .  
         [0125]    In step  1008 , a determination is made of whether “t” is greater (later) than 13:55. If the determination is made that “t” is not greater than 13:55, the process returns to step  1006 , and repeats steps  1006  and  1007  until the determination is made that “t” is greater than 13:55. If the determination is made that “t” is greater than 13:55, the process proceeds to step  1009 .  
         [0126]    In step  1009 , the power supply  105  is turned off, and the computer  101  knows that the user has gone out. As described above, when the present time “t” becomes greater than 13:55, the state of the power supply  105  of the computer  101  transits from a state of P=Pon to that of P=Poff.  
         [0127]    Finally, the process proceeds to step  1010 . The power supply  105  of the computer  101  remains turned off.  
         [0128]    If a determination is made in step  1005  that the present time “t” is not greater than 13:30, the process proceeds to step  1014 . The state of the schedule manager  104  is changed from m=Mwork to m=Min.  
         [0129]    In step  1014 , the power supply  105  is on and the schedule manager  104  knows that the user has stepped out, instead of having gone out.  
         [0130]    In step  1015 , a determination is made of whether the IC card  902  is set in the IC card reader/writer  901 . If the determination is made that the IC card  902  is set in the IC card reader/writer  901  (d=Don), the process returns to step  1002  for repeating steps starting with step  1002 . If the determination is made in step  1015  that the IC card  902  is not set in the IC card reader/writer  901  (d=Doff), the process proceeds to step  1016 .  
         [0131]    In step  1016 , a determination is made of whether “t” is greater than 13:55. If a determination is made that “t” is not greater than 13:55, the process returns to step  1014 , and steps  1014  and  1015  are repeated. If a determination is made that “t” is greater than 13:55, the process proceeds to step  1017 .  
         [0132]    In step  1017 , a determination is made of whether the user has set the computer  101  so that, when the user is not around the computer  101 , the computer  101  is automatically turned off (c=AutoOn). If the computer is not set to c=AutoOn (c=AutoOff), the process returns to step  1014  without executing any step. That is, when m=Min, and the present time “t” is greater than 13:55, the computer  101  remains in the state m=Min and p=Pon as set by the user. In other words, if c=AutoOn, then when the present time “t” becomes greater than 13:55 regardless of “m”, the state of the power supply  105  is turned to p=Poff. If c=AutoOff, the state at time “t” being less than 13:55 is maintained.  
         [0133]    On the other hand, if c=AutoOn, the process proceeds to step  1009 . Steps  1009  and  1010  are executed.  
         [0134]    In step  1009 , since d=Doff, and the present time “t” is greater than 13:55, the state of the computer  101  transits from p=Pon to p=Poff.  
         [0135]    A fifth embodiment of the present invention is described with reference to FIGS. 11 and 12. FIG. 11 is a schematic diagram showing a computer system  1100  according to the fifth embodiment. Elements identical to those shown in the previous drawings are referred to by the same reference numerals, and their description is omitted. FIG. 12 is a flowchart showing the operation of the computer  101  according to the fifth embodiment.  
         [0136]    The computer system  1100  shown in FIG. 11 includes the computer (processing unit)  101 , the operating system  103 , the schedule manager (software)  104 , the keyboard  601  connected to the computer  101 , the monitor  602  connected to the computer  101 , a wireless receiver  1101 , a wireless card  1102 , and a printer  1103 . The wireless receiver  1101  and the wireless card  1102  constitute the user detection device  102  shown in FIG. 1. The wireless receiver  1101  and the wireless card  1102 , that is, the user detection device  102 , determines that the user is around the computer  101  by determining whether the wireless card  1102  is connected to the wireless receiver  1101  via a wireless communication channel  1104 .  
         [0137]    The user is required to have the wireless card  1102  to establish connection between the wireless card  1102  and the wireless receiver  1101  via the wireless communication channel  1104 . While the user is around the computer  101 , the wireless receiver  1101  receives a signal from the wireless card  1102 . The wireless receiver  1101  informs the computer  101  that the wireless card  1102  is connected thereto (that is, the user is around). The user may use the printer  1103  for printing data the user needs while going out.  
         [0138]    The schedule manager  104  running on the computer  101  displays the schedule window  603  on the monitor  602 . The schedule window  603  shown in FIG. 11 is the same as that shown in FIG. 7. An operation “when going out, printing a file F to PDA  903 ” is set as “Z”.  
         [0139]    In step  1201  shown in FIG. 10, the power supply  105  is turned on. The process proceeds to step  1202 .  
         [0140]    In step  1202 , the power supply  105  is on, and the computer  101  operates normally.  
         [0141]    In step  1203 , a determination is made as to whether “t” is equal to 13:30. If the determination is made that “t” is equal to 13:30, the process proceeds to step  1211 .  
         [0142]    In step  1211 , a determination of whether z=0 is made. Since an operation is set at “Z”, and as a result, z is not equal to 0, the process proceeds to step  1212 .  
         [0143]    In step  1212 , the message is sent and/or the alarm is sounded, and the process proceeds to step  1213 . As described above, in the case in which d=Don (a state in which the user detection device  102  detects the user), when the present time “t” becomes equal to 13:30, and if z=0, the schedule manager (software)  104  displays a message or sounds an alarm to inform the user that the time (of the item of schedule) is coming.  
         [0144]    In step  1213 , the operation Z related by the user is performed. That is, when the present time “t” is equal to 13:30, since “z” is set at “z=Z”, the operation “Z” in which the file F is printed by the printer  1103  is performed. The process then proceeds to step  1202 .  
         [0145]    If a determination is made that “t” is not equal to 13:30 in step  1203 , the process proceeds to step  1204 .  
         [0146]    In step  1204 , a determination is made as to whether the wireless receiver  1101  receives the signal from the wireless card  1102 . If a determination is made that the wireless receiver  1101  receives the signal from the wireless card  1102  (d=Don), the process returns to step  1202 , and repeats the above steps. If the determination is made that the wireless receiver  1101  does not receive the signal from the wireless card  1102  (d=Doff), the process proceeds to step  1205 .  
         [0147]    In step  1205 , a determination is made whether the present time “t” is greater (later) than 13:30. If a determination is made that “t” is greater than 13:30, the process proceeds to step  1206 .  
         [0148]    In step  1206 , the power supply  105  is on, and the computer  101  learns (determines) that the user has gone out. If the user has gone out in response to the message or the alarm sounded in step  1212 , for example, the wireless receiver  1101  determines that the state of the user has changed. The wireless receiver  1101  informs the computer  101  of the state d=Doff. If the computer determines that the present time “t” is greater than 13:30, the computer  101  transits from the state “m=Mwork” to the state “m=Mout”. The process proceeds to step  1207 .  
         [0149]    In step  1207 , a determination is made as to whether the wireless receiver  1101  receives the signal from the wireless card  1102 . If a determination is made that the wireless receiver  1101  receives the signal from the wireless card  1102  (d=Don) in step  1207 , the process returns to step  1202 , and repeats the above steps. If the determination is made in step  1207  that the wireless receiver  1101  does not receive the signal from the wireless card  1102  (d=Doff), the process proceeds to step  1208 .  
         [0150]    In step  1208 , a determination is made as to whether “t” is greater (later) than 13:55. If the determination is made that “t” is not greater than 13:55, the process returns to step  1206 , and repeats steps  1206  and  1207  until the determination is made that “t” is greater than 13:55. If the determination is made that “t” is greater than 13:55, the process proceeds to step  1209 .  
         [0151]    In step  1209 , the power supply  105  is turned off, and the computer  101  knows that the user has gone out. As described above, when the present time “t” becomes greater than 13:55, the state of the power supply  105  of the computer  101  transits from a state P=Pon to the state P=Poff.  
         [0152]    Finally, the process proceeds to step  1210 . The power supply  105  of the computer  101  remains turned off.  
         [0153]    If a determination is made in step  1205  that the present time “t” is not greater than 13:30, the process proceeds to step  1214 . The state of the schedule manager  104  is changed from m=Mwork to m=Min.  
         [0154]    In step  1214 , the power supply  105  is on and the schedule manager  104  knows that the user has stepped out, instead of having gone out.  
         [0155]    In step  1215 , a determination is made as to whether the wireless receiver  1101  receives the signal from the wireless card  1102 . If the determination is made that the wireless receiver  1101  receives the signal from the wireless card  1102  (d=Don), the process returns to step  1202  for repeating steps starting with step  1202 . If the determination is made in step  1215  that the wireless receiver  1101  does not receive the signal from the wireless card  1102  (d=Doff), the process proceeds to step  1216 .  
         [0156]    In step  1216 , a determination is made as to whether “t” is greater than 13:55. If a determination is made that “t” is not greater than 13:55, the process returns to step  1214 , and steps  1214  and  1215  are repeated. If a determination is made that “t” is greater than 13:55, the process proceeds to step  1217 .  
         [0157]    In step  1217 , a determination is made as to whether the user has set the computer  101  so that, when the user is not around the computer  101 , the computer  101  is automatically turned off (c=AutoOn). If the computer is not set to c=AutoOn (c=AutoOff), the process returns to step  1214  without executing any step. That is, when m=Min, and the present time “t” is greater than 13:55, the computer  101  remains in the state m=Min and p=Pon as set by the user. In other words, if c=AutoOn, then when the present time “t” becomes greater than 13:55 regardless of “m”, the state of the power supply  105  is turned to p=Poff. If c=AutoOff, the state at time “t” being less than 13:55 is maintained.  
         [0158]    On the other hand, if c=AutoOn, the process proceeds to step  1209 . Steps  1209  and  1210  are executed.  
         [0159]    In step  1209 , since d=Doff, and the present time “t” is greater than 13:55, the state of the computer  101  transits from p=Pon to p=Poff.  
         [0160]    As described above, it is possible to control the power supply of a computer based on both the state of a user that is determined by the computer and the user&#39;s schedule that is input by the user.  
         [0161]    The present invention is not limited to these embodiments, but various variations and modifications may be made without departing from the scope of the present invention.  
         [0162]    This patent application is based on Japanese priority patent application No. 2003-130561 filed on May 8, 2003, the entire contents of which are hereby incorporated by reference.