Patent Publication Number: US-2018041629-A1

Title: Information processing device and lock control method

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2016-152812, filed on Aug. 3, 2016, the entire contents of which are incorporated herein by reference. 
     FIELD 
     The embodiment discussed herein is related to an information processing device and a lock control method. 
     BACKGROUND 
     In late years, it is not uncommon to see a single user owning multiple terminal devices such a personal computer (PC), a tablet, a smartphone, and so forth. 
     These terminal devices are often equipped with a lock function for the purpose of security improvement. When a terminal device is not operated for a preset period, the lock function is designed to fixedly display an input screen for unlocking, for example, and to reject operations other than an unlocking operation. A preset specific input operation using password input, biometric authentication, or the like is to be performed in order to release a locked state. 
     Related techniques are disclosed in, for example, Japanese Laid-open Patent Publication No. 2006-102948, Japanese Laid-open Patent Publication No. 2008-226210, Japanese Laid-open Patent Publication No. 2008-193166, Japanese Laid-open Patent Publication No. 2009-15501, and Japanese Laid-open Patent Publication No. 2005-99515. 
     A possible example of allowing a single user to employ multiple terminal devices as described above is a case in which a first terminal device is used to display an electronic document such as a documented work instruction while a second terminal device is operated to conduct work and the like. In this method of use, the first terminal device displaying the documented work instruction is kept unoperated during the operation using the second terminal device. This may lead to a situation in which the first terminal device activates a lock function every time there is a lapse of a certain period, and a worker has to perform an input operation for unlocking in each case. As a consequence, this case may result in reduced work efficiency. 
     Here, a possible option for cutting out cumbersome input operations for unlocking is to set the terminal device displaying the electronic document not to make a transition to a locked state even when the terminal device is left unoperated for a long period. However, the setting not to make a transition to a locked state even when the terminal device is left unoperated for a long period as described above brings about a longer period for allowing anyone to operate the terminal device, and a security level thereof is decreased as a consequence. 
     SUMMARY 
     According to an aspect of the present invention, provided is an information processing device including a memory and a processor coupled to the memory. The processor is configured to establish a locked state of the information processing device. The processor is configured to search for a first device among information processing devices, the first device being located in a predetermined area from the information processing device. The first device is operated by a user operating the information processing device. The processor is configured to inhibit the establishment of the locked state of the information processing device when the first device is found. 
     The object and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the claims. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a diagram illustrating an exemplary configuration of a computer system according to an embodiment; 
         FIG. 2  is a diagram illustrating an exemplary functional configuration of a lock control unit in the computer system according to the embodiment; 
         FIG. 3  is a diagram illustrating device information in the computer system according to the embodiment; 
         FIG. 4  is a diagram illustrating connection state management information in the computer system according to the embodiment; 
         FIG. 5  is a diagram illustrating in-operation state management information in the computer system according to the embodiment; 
         FIG. 6  is a diagram illustrating processing by a lock inhibition control unit in the computer system according to the embodiment; 
         FIG. 7  is a diagram illustrating processing by lock inhibition control units in the computer system according to the embodiment; 
         FIG. 8  is a flowchart illustrating a method of searching for a nearby information processing device performed by a search unit in the computer system according to the embodiment; and 
         FIG. 9  is a flowchart illustrating a log-on control method at a start-up of an information processing device in the computer system according to the embodiment. 
     
    
    
     DESCRIPTION OF EMBODIMENT 
     An embodiment of an information processing device and a lock control method will be described below with reference to the drawings. 
       FIG. 1  is a diagram illustrating an exemplary configuration of a computer system  1  according to the embodiment. 
     The computer system  1  illustrated in  FIG. 1  includes multiple (five in the example illustrated in  FIG. 1 ) information processing devices  10 - 1  to  10 - 5 , and is installed in a home of a user, for instance. 
     The information processing devices  10 - 1  to  10 - 5  are communicably coupled to one another through a network  50 . 
     For example, the information processing devices  10 - 1  to  10 - 3  are wire-coupled to a not-illustrated router through local area network (LAN) cables, respectively. 
     The network  50  is provided with a wireless router  40  and the information processing devices  10 - 4  and  10 - 5  are wirelessly coupled to the network  50  through the wireless router  40  serving as a wireless access point (AP). 
     The information processing devices  10 - 1  to  10 - 5  have similar configurations. For the sake of convenience,  FIG. 1  depicts a hardware configuration of only the information processing device  10 - 1 , and illustration of hardware configurations of the information processing devices  10 - 2  to  10 - 5  is omitted therein. 
     Hereinafter, particular ones of the information processing devices may be referred to as the information processing devices  10 - 1  to  10 - 5 , and an arbitrary one of the information processing devices may be referred to as an information processing device  10 . In addition, an information processing device  10  may also be referred to as a terminal  10  in the following description. 
     As illustrated in  FIG. 1 , each information processing device  10  includes a central processing unit (CPU)  11 , a memory  12 , a storage device  13 , a display unit  14 , and a communication interface  15 . 
     The storage device  13  is a storage device configured to store various data, and is a hard disk drive (HDD), a solid state drive (SSD), a storage class memory (SCM), and the like. 
     The memory  12  is a storage memory including a read-only memory (ROM) and a random access memory (RAM). 
     A software program (a lock control program) for lock control, data used in association with the program, and the like are written in the ROM of the memory  12 . The software program stored in the memory  12  is appropriately read and executed by the CPU  11 . The RAM of the memory  12  is used as a temporary storage memory or as a working memory. 
     The communication interface  15  provides a communication function to perform communication with other information processing devices  10  and the like. The communication interface  15  is a LAN card or a wireless LAN communication module, for instance. The communication interface  15  also includes a wireless communication module that employs Bluetooth (registered trademark) and the like. 
     In the example illustrated in  FIG. 1 , each of the information processing devices  10 - 1  to  10 - 3  wire-coupled to the network  50  is provided with a LAN card as the communication interface  15 . Meanwhile, each of the information processing devices  10 - 4  and  10 - 5  wirelessly coupled to the wireless router  40  is provided with a wireless LAN module as the communication interface  15 . 
     The CPU  11  is a processing unit that performs various control and arithmetic operations. The CPU  11  executes an operating system (OS) and software stored in the memory  12  and the like, thereby realizing various functions. A multiprocessor may be constructed by using multiple CPUs  11 . Any one of a micro processing unit (MPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), and a field programmable gate array (FPGA) may be provided instead of the CPU. Two or more elements of the CPU, the MPU, the DSP, the ASIC, the PLD, and the FPGA may be used in combination. 
     The CPU  11  of the information processing device  10  executes the lock control program to function as a lock control unit  100  (see  FIG. 2 ) to be described later. 
     The program (the lock control program) for realizing the function as the lock control unit  100  is provided in the form recorded in any of computer-readable recording media including a flexible disc, a compact disc (CD) such as a CD-ROM, a CD-R, and a CD-RW, a digital versatile disc (DVD) such as a DVD-ROM, a DVD-RAM, a DVD-R, a DVD+R, a DVD-RW, a DVD+RW, and an HD DVD, a Blu-ray disc, a magnetic disc, an optical disc, a magneto-optical disc, and the like. The CPU  11  reads the program out of such a recording medium, and then transfers and stores the program into an internal storage device or an external storage device to use the program. Alternatively, the program may be recorded in a storage device (a recording medium) such as a magnetic disc, an optical disc, and a magneto-optical disc in advance, and may be provided from the storage device to a computer through a communication path. 
     To realize the function as the lock control unit  100 , the program stored in the internal storage device (which is the RAM or the ROM in the memory  12  in this embodiment) is executed by a microprocessor (which is the CPU  11  in this embodiment) of the computer. The computer may read and execute the program recorded in the recording medium. 
       FIG. 2  is a diagram illustrating a functional configuration of the lock control unit  100  in the computer system  1  according to the embodiment. 
     In the information processing device  10 , the lock control unit  100  controls the lock function of the information processing device  10 . 
     As illustrated in  FIG. 2 , the lock control unit  100  is equipped with functions as a lock processing unit  101 , a search unit  102 , a lock inhibition control unit  103 , and an in-operation state management unit  104 . 
     The search unit  102  searches for another information processing device  10  located near the own information processing device  10  which includes the search unit  102 . Here, a location near the own information processing device  10  is preferably a location at such a distance that renders the other information processing device  10  directly visible from the location of the own information processing device  10 , for example. 
     For instance, when the multiple information processing devices  10  are used at such distances that render the information processing devices  10  visible from one another at home or the like, then the information processing devices  10  are thought to be used by the same person. 
     In this case, if one (a first information processing device  10 ) of the information processing devices  10  is accepting an operation input (being operated) by a user and another one (a second information processing device  10 ) of the information processing devices  10  is also being operated by the same user, then these information processing devices  10  are thought to be used in parallel by the user. In other words, the second information processing device  10  is thought to have no security problem while the first information processing device  10  is being operated even if the second information processing device  10  is not locked. 
     Accordingly, in the computer system  1 , the search unit  102  of a certain one of the information processing device  10  searches for another information processing device  10  located in a predetermined area around the one of the information processing devices  10 . The one of the information processing devices  10 , which includes the search unit  102 , may be referred to as an own information processing device  10 . 
     For example, the search unit  102  determines the presence of another information processing device  10  through the network  50  by issuing (outputting) a network management command (an information collection command) of the OS or by using an application programming interface (API). Such check of presence of the information processing device  10  on the network  50  may be realized by using various known methods and detailed description thereof will be omitted. 
     The search unit  102  may collect device information  111  as illustrated in  FIG. 3  by checking the presence of the information processing device  10  on the network  50  as described above. 
       FIG. 3  is a diagram illustrating the device information  111  in the computer system  1  according to the embodiment. 
     The device information  111  is information on the respective information processing devices  10  included in the computer system  1 . The device information  111  illustrated in  FIG. 3  includes the following fields of terminal identification (ID), Internet protocol (IP) address, media access control (MAC) address, terminal name, and in-operation state management. 
     Note that the in-operation state management field indicates whether or not each information processing device  10  is equipped with a function as the in-operation state management unit  104  to be described later. When “equipped” is registered in the in-operation state management field for an information processing device  10 , it indicates that the information processing device  10  is equipped with the function as the in-operation state management unit  104 . On the other hand, when “not equipped” is registered in the in-operation state management field for an information processing device  10 , it indicates that the information processing device  10  is not equipped with the function as the in-operation state management unit  104 . 
     For example, the in-operation state management unit  104  to be described later exchanges in-operation state information with other information processing devices  10  through the network  50  at start-up of the own information processing device  10  or each time after a lapse of a predetermined period. Then, “equipped” is registered in the in-operation state management field of the information processing device  10  which successfully transmits and receives the in-operation state information. 
     The search unit  102  stores collected pieces of information on the respective information processing devices  10  in the storage device  13  and the like as the device information  111 . 
     Each information processing device  10  is equipped with functions to acquire connection state management information  112  for managing connection states of the respective information processing devices  10  included in the computer system  1 , and to store the acquired information in the storage device  13  and the like. 
       FIG. 4  is a diagram illustrating the connection state management information  112  in the computer system  1  according to the embodiment. 
     The connection state management information  112  illustrated in  FIG. 4  includes the following fields of MAC address, IP address, connection method type, and gateway. 
     In the example illustrated in  FIG. 4 , any one of “wired LAN”, “wireless LAN”, and “Bluetooth” is set to the connection method type field. The gateway field represents an address (a gateway address) of a gateway used for access to a device identified by the MAC address. 
     Collection of a variety of information to be registered in the connection state management information  112  may be realized by using various known methods and specific description thereof will be omitted. 
     Various pieces of information to be registered in the connection state management information  112  may be associated with one another by using a plug and play function of the OS or by using network management information. Alternatively, a database may be used for the information association. 
     The search unit  102  determines whether or not each of the information processing devices  10  registered in the device information  111  is located near the own information processing device  10 . In the following, each information processing device  10  subjected to the determination by the search unit  102  as to whether or not the relevant information processing device  10  is located near the own information processing device  10  may be referred to as a determination target information processing device  10 . 
     The search unit  102  selects each of the information processing devices  10  registered in the device information  111  as the determination target information processing device  10 , and determines whether or not the determination target information processing device  10  is located near the own information processing device  10 , based on a connection method between the determination target information processing device  10  and the own information processing device  10 . 
     A description will be given below of the method of determination by the search unit  102  as to whether or not the determination target information processing device  10  is located near the own information processing device  10 , that is, whether or not the determination target information processing device  10  is located in the predetermined area around the own information processing device  10 . 
     When the own information processing device  10  is wirelessly coupled to the determination target information processing device  10 , the search unit  102  determines that the determination target information processing device  10  is located near the own information processing device  10  if any one of the following conditions (a1) to (a3) is met. 
     (a1) If the determination target information processing device  10  and the own information processing device  10  are coupled to the same wireless AP, the search unit  102  determines that the determination target information processing device  10  is located near the own information processing device  10 . 
     The determination as to whether or not the access point is the same may be achieved by using the IP address, the MAC address, and the like of the gateway serving as the connection destination (see  FIG. 4 ). 
     (a2) If the determination target information processing device  10  and the own information processing device  10  are coupled to each other through Wi-Fi Direct (registered trademark), which is one of short-distance wireless connections, the search unit  102  determines that the determination target information processing device  10  is located near the own information processing device  10 . 
     Whether or not the information processing devices  10  are coupled through Wi-Fi Direct may be checked by using a network management function of the OS. 
     (a3) If the determination target information processing device  10  and the own information processing device  10  are coupled to each other through Bluetooth, which is one of short-distance wireless connections, the search unit  102  determines that the determination target information processing device  10  is located near the own information processing device  10 . 
     Whether or not the information processing devices  10  are coupled through Bluetooth may be checked by referring to the connection method type associated with the MAC address in the above-described connection state management information  112  (see  FIG. 4 ), for example. 
     Note that even when the determination target information processing device  10  is wirelessly coupled to the own information processing device  10 , the search unit  102  determines that the determination target information processing device  10  is not located near the own information processing device  10  if none of the above-described conditions (a1) to (a3) is met. 
     When the own information processing device  10  is wire-coupled to the determination target information processing device  10 , the search unit  102  determines that the determination target information processing device  10  is located near the own information processing device  10  if any one of the following conditions (b1) and (b2) is met. 
     (b1) If the determination target information processing device  10  is directly connected to the own information processing device  10  through a cross cable, the search unit  102  determines that the determination target information processing device  10  is located near the own information processing device  10 . 
     The direct connection between the determination target information processing device  10  and the own information processing device  10  may be determined by referring to the IP addresses of the determination target information processing device  10  and the own information processing device  10 , or time to live (TTL) values in network communication (IP packet) therebetween, for example. 
     (b2) If the determination target information processing device  10  and the own information processing device  10  are coupled to the same router (not illustrated), the search unit  102  determines that the determination target information processing device  10  is located near the own information processing device  10 . 
     The determination as to whether or not the information processing devices  10  are coupled to the same router may be achieved by referring to the IP address or the MAC address of the connection destination, the IP address or the MAC address of the gateway, or the like. 
     Note that even when the determination target information processing device  10  is wire-coupled to the own information processing device  10 , the search unit  102  determines that the determination target information processing device  10  is not located near the own information processing device  10  if none of the above-described conditions (b1) and (b2) is met. 
     As described above, the search unit  102  determines whether or not the determination target information processing device  10  is located near the own information processing device  10  by checking the connection state between the own information processing device  10  and the determination target information processing device  10 . Specifically, the search unit  102  reckons a distance between the own information processing device  10  and the determination target information processing device  10  by determining whether or not any of the above-described conditions (a1) to (a3), (b1), and (b2) is met with regard to the connection state between the own information processing device  10  and the determination target information processing device  10 . 
     In other words, the search unit  102  presumes that the determination target information processing device  10  is located in the predetermined area from the own information processing device  10 , and the determination target information processing device  10  is therefore located near the own information processing device  10  when any one of the above-described conditions (a1) to (a3), (b1), and (b2) is met. 
     By checking the connection state between the own information processing device  10  and the determination target information processing device  10 , the search unit  102  may determine whether or not the determination target information processing device  10  is located in the predetermined area from the own information processing device  10 , without being provided with a distance measurement device. 
     In the following, another information processing device  10  determined by the search unit  102  as being located in the predetermined area from the own information processing device  10  may be referred to as a neighboring information processing device  10 . 
     The in-operation state management unit  104  manages operations performed on the own information processing device  10 . The in-operation state management unit  104  manages information on the operations performed on the own information processing device  10  by using in-operation state management information  113 . 
       FIG. 5  is a diagram illustrating the in-operation state management information  113  in the computer system  1  according to the embodiment. 
     The in-operation state management information  113  illustrated in  FIG. 5  includes the following fields of user, in-operation state, last access date and time, and specific application. 
     Specifically, the in-operation state management information  113  manages the in-operation state, the last access date and time, and the specific application for each of users (log-on accounts) registered in the own information processing device  10 . The last access date and time indicates the date and time when the latest operation is detected. 
     The specific application field indicates whether or not a prescribed specific application program (a specific application) is executed. 
     In the computer system  1 , the user is determined to be performing an operation while the specific application program (the specific application) is being executed. In other words, even in the state where an input operation or the like by the user (a log-on user) does not take place, the log-on user is presumed to be performing an operation when the specific application is being executed. 
     The in-operation state field indicates whether or not the user is performing an operation. When the user is performing an operation, “in operation” is registered in the in-operation state field. When the user is not performing an operation, “not in operation” is registered in the in-operation state field. 
     The in-operation state management unit  104  determines that the own information processing device  10  is being operated if any one of the following conditions (c1) to (c3) is met. 
     (c1) The own information processing device  10  is determined to be being operated when the own information processing device  10  is not locked. 
     (c2) The own information processing device  10  is determined to be being operated during a predetermined period after an input operation with an input device (not illustrated) such as a keyboard, a mouse, and a touch panel. 
     (c3) The own information processing device  10  is determined to be being operated while the specific application program (the specific application) is being executed. 
     In answer to an inquiry about the in-operation state from the lock inhibition control unit  103  of another information processing device  10  to be described later, the in-operation state management unit  104  sends a response containing information on the in-operation state. 
     By managing the in-operation state management information  113  as described above, the in-operation state management unit  104  may grasp whether or not the user logging on the own information processing device  10  is operating the own information processing device  10 . 
     It may be determined that the user is in a state of logged-on only during a period when the user account is actually in the state of logged-on. When the user account had logged on and then logged off, it may be determined that the user is still in the state of logged-on until a predetermined period elapses. 
     Upon receipt of a request inquiring about the in-operation state, which is sent from the lock inhibition control unit  103  of another information processing device  10  to the own information processing device  10 , the in-operation state management unit  104  may send a response containing the in-operation state of the own information processing device  10 . 
     Here, in answer to the inquiry about the in-operation state from the lock inhibition control unit  103  of the other information processing device  10 , the in-operation state management unit  104  may send a response containing the in-operation states concerning all the users managed in the in-operation state management information  113 , or send a response containing only the in-operation state concerning the particular user involved in the inquiry. 
     Upon receipt of the request inquiring about the in-operation state, which is sent from the lock inhibition control unit  103  of the other information processing device  10 , the in-operation state management unit  104  sends a response containing the in-operation state management information  113  indicating the in-operation state of the own information processing device  10 . 
     The settings concerning the above-described conditions (c1) to (c3) are stored in the storage device  13  of the own information processing device  10 , for example. 
     When the own information processing device  10  satisfies a prescribed condition (a locking condition), the lock processing unit  101  establishes a locked state of the own information processing device  10 . In the locked state, the lock processing unit  101  fixedly displays an input screen used for inputting a password for unlocking, for example, and rejects operations other than an unlocking operation. 
     The locking condition is defined as absence of an input operation for a predetermined period (such as 1 minute), for example. Accordingly, the lock processing unit  101  does not establish the locked state when the own information processing device  10  is being operated. Since the own information processing device  10  is considered to be being operated if any one of the above-described conditions (c1) to (c3) is met, the lock processing unit  101  does not establish the locked state in this case. In other words, the locking condition remains unsatisfied as long as the own information processing device  10  is being operated. 
     Note that in the computer system  1 , information indicating the locking condition (such as information to define a non-operation period before transition to the locked state) is stored in the storage device  13  of each information processing device  10 . 
     The lock inhibition control unit  103  performs control such that the lock processing unit  101  is inhibited from causing the own information processing device  10  to make a transition to the locked state. 
     When another information processing device  10  is located in the predetermined area around the own information processing device  10 , the lock inhibition control unit  103  inhibits the lock processing unit  101  from causing the own information processing device  10  to make a transition to the locked state if the other information processing device  10  is being operated by the same user as the one operating the own information processing device  10 . 
     In this regard, when the own information processing device  10  satisfies the locking condition, the lock inhibition control unit  103  causes the search unit  102  to search for another information processing device  10  located in the predetermined area around the own information processing device  10 . 
     When the search unit  102  detects another information processing device  10  located in the predetermined area around the own information processing device  10 , the lock inhibition control unit  103  checks with the other information processing device  10  (the neighboring information processing device  10 ) whether or not the neighboring information processing device  10  is being operated by the same user as the one operating the own information processing device  10 . 
     The lock inhibition control unit  103  sends the neighboring information processing device  10  a user ID and the like on the user logging on the own information processing device  10 , for example, thereby inquiring whether or not the log-on user is operating the neighboring information processing device  10 . 
     The lock inhibition control unit  103  may inquire the neighboring information processing device  10  about a user who is operating the neighboring information processing device  10 . 
       FIG. 6  is a diagram illustrating processing by the lock inhibition control unit  103  in the computer system  1  according to the embodiment. 
       FIG. 6  illustrates an example in which the lock inhibition control unit  103  of a terminal #1 inquires with the in-operation state management unit  104  of a terminal #2 about the in-operation state of the terminal #2. For instance, the lock inhibition control unit  103  of the terminal #1 sends the user ID and the like on the user logging on the own information processing device  10  to the in-operation state management unit  104  of the terminal #2, for example, thereby inquiring whether or not the log-on user is operating the terminal #2. 
     The lock inhibition control unit  103  receives the in-operation state responded from the in-operation state management unit  104  of the neighboring information processing device  10 . Then, the lock inhibition control unit  103  inhibits the lock processing unit  101  from causing the own information processing device  10  to make a transition to the locked state when the responded in-operation state indicates that the user logging on the own information processing device  10  is operating the neighboring information processing device  10 . 
     As illustrated in  FIG. 6 , the lock inhibition control unit  103  may inquire about the in-operation state and receiving the response by using one-to-one communication with the neighboring information processing device  10 , for example. 
       FIG. 7  is a diagram illustrating processing by the lock inhibition control units  103  in the computer system  1  according to the embodiment.  FIG. 7  illustrates an example in which the respective lock inhibition control units  103  of multiple (two in the example illustrated in  FIG. 7 ) terminals #1 and #2 inquire with the respective in-operation state management units  104  of multiple (three in the example illustrated in  FIG. 7 ) terminals #3 to #5 about the in-operation states of the respective terminals  10 . 
     Each lock inhibition control unit  103  may also inquire with each information processing device  10  about in-operation information by conducting broadcast communication with the other information processing devices  10 , for instance. 
     A method of searching for a nearby information processing device  10  performed by the search unit  102  in the computer system  1  according to the embodiment of the above-described configuration will be described with reference to a flowchart illustrated in  FIG. 8 . 
     In A 1 , the search unit  102  starts searching for a terminal  10  coupled through the network  50 . 
     The search unit  102  searches for another terminal  10 , which is coupled to the own information processing device  10  through the network  50 , by issuing an information collection command for collecting information to other information processing devices  10  through the network  50 , for example. 
     The search unit  102  checks whether or not another terminal  10  is found as a consequence of the search (A 2 ), and proceeds to A 3  when another terminal  10  is found (YES in A 2 ). 
     In A 3 , the search unit  102  checks a connection method between the own information processing device  10  and the found terminal  10 , that is, the determination target information processing device  10 . 
     As a result of checking the connection method (A 4 ), the search unit  102  proceeds to A 5  when the own information processing device  10  is wirelessly coupled to the determination target information processing device  10  ([wireless connection] in A 4 ). 
     In A 5 , the search unit  102  checks the wireless connection state between the own information processing device  10  and the determination target information processing device  10  by referring to the connection state management information  112  (see  FIG. 4 ), for example. 
     As a result of the check, the search unit  102  proceeds to A 6  when the own information processing device  10  and the determination target information processing device  10  are coupled to each other by short-distance wireless connection ([short-distance radio] in A 5 ) or are coupled to the same wireless AP ([same wireless AP] in A 5 ). 
     In A 6 , the search unit  102  determines that the determination target information processing device  10  is located near the own information processing device  10 . 
     Thus, another terminal  10  located near the own information processing device  10  is found by the search unit  102 . Hence, the search unit  102  notifies the lock inhibition control unit  103  of the other terminal  10  as the neighboring information processing device  10  in A 7 . Thereafter, the processing is terminated. 
     As a result of the check in A 5 , the search unit  102  proceeds to A 8  when the own information processing device  10  and the determination target information processing device  10  are neither coupled to each other by short-distance wireless connection nor coupled to the same wireless AP ([otherwise] in A 5 ). 
     In A 8 , the search unit  102  determines that the determination target information processing device  10  is not located near the own information processing device  10 , and then proceeds to A 9 . 
     In A 9 , the search unit  102  determines that there is no other terminal  10  located near the own information processing device  10 , and terminates the processing. 
     As a result of the check in A 4 , the search unit  102  proceeds to A 10  when the own information processing device  10  is wire-coupled to the determination target information processing device  10  ([wired connection] in A 4 ). 
     In A 10 , the search unit  102  checks the wired connection state between the own information processing device  10  and the different terminal  10  by referring to the connection state management information  112 , for example. 
     As a result of the check, the search unit  102  proceeds to A 6  when the own information processing device  10  and the determination target information processing device  10  are directly connected to each other ([directly connected] in A 10 ) or are coupled to the same router ([same router] in A 10 ). 
     As a result of the check in A 10 , the search unit  102  proceeds to A 11  when the own information processing device  10  and the determination target information processing device  10  are neither directly connected to each other nor coupled to the same router ([otherwise] in A 10 ). 
     In A 11 , the search unit  102  determines that the determination target information processing device  10  is not located near the own information processing device  10 , and then proceeds to A 9 . 
     As a result of the check in A 2 , the search unit  102  also proceeds to A 9  when no other terminal  10  is found (NO in A 2 ). 
     As a result of the check in A 4 , the search unit  102  also proceeds to A 9  when the connection method between the own information processing device  10  and the determination target information processing device  10  is unclear ([unclear] in A 4 ). 
     Next, a log-on control method at a start-up of the information processing device  10  in the computer system  1  according to the embodiment will be described with reference to a flowchart illustrated in  FIG. 9 . 
       FIG. 9  illustrates a case in which the information processing device  10  (the terminal #1) is shared by multiple users and a user A among the multiple users is using the terminal #1. 
     In B 1 , the lock processing unit  101  of the terminal #1 checks whether or not the locking condition is met. Specifically, the lock processing unit  101  checks whether or not the terminal #1 is not being operated (left unoperated) continuously for a predetermined period (such as 1 minute). When the locking condition is not met, (NO in B 1 ), B 1  is repeated until the locking condition is met. 
     The lock processing unit  101  proceeds to B 2  when the unoperated period continues for the predetermined period or more and the locking condition is thus met (YES in B 1 ). 
     In B 2 , the search unit  102  of the terminal #1 searches for a terminal  10  located near the own information processing device  10  by issuing the information collection command. 
     Based on information sent from another information processing device  10  in response to the information collection command, the search unit  102  determines whether or not the other information processing device  10  is located in the predetermined area around the own information processing device  10  (B 3 ). 
     As a result of the determination, the search unit  102  proceeds to B 4  when the other information processing device  10  (the terminal #2 in the example illustrated in  FIG. 9 ) is located near the own information processing device  10  (YES in B 3 ). In other words, the terminal #2 is a neighboring information processing device  10 . 
     In B 4 , the lock inhibition control unit  103  of the terminal #1 sends an inquiry to the terminal #2 to check whether or not the user A is operating the terminal #2. 
     The in-operation state management unit  104  of the terminal #2 checks whether or not the user A is operating its own information processing device  10  (terminal #2) by referring to the in-operation state management information  113  of the terminal #2. The in-operation state management unit  104  of the terminal #2 sends a result to the terminal #1 as a response. 
     In B 5 , based on the response from the terminal #2, the lock inhibition control unit  103  checks whether or not the user A is operating the terminal #2. 
     As a result of the check, when the user A is operating the terminal #2 (YES in B 5 ), the lock inhibition control unit  103  inhibits the lock processing unit  101  from causing the own information processing device  10  to make a transition of the own information processing device  10  to the locked state (B 6 ). In other words, the terminal #1 is kept unlocked. Thereafter, the processing returns to B 1 . 
     As a result of the check in B 3 , when no other information processing device  10  is located near the own information processing device  10  (the terminal #1) (NO in B 3 ), the lock inhibition control unit  103  does not inhibit the locking by the lock processing unit  101  in B 7 . In other words, the lock processing unit  101  establishes the locked state of the own information processing device  10  (the terminal #1). 
     As a result of the check in B 5 , the lock inhibition control unit  103  also proceeds to B 7  when the user A is not operating the terminal #2 (NO in B 5 ). Here, the lock processing unit  101  establishes the locked state of the own information processing device  10  (the terminal #1). Thereafter, the processing is terminated. 
     As described above, in the computer system  1  according to the embodiment, when another information processing device  10  is located in the predetermined area around the own information processing device  10 , the lock inhibition control unit  103  inhibits the lock processing unit  101  from causing the own information processing device  10  to make a transition to the locked state if the other information processing device  10  is being operated by the same user as the one operating the own information processing device  10 . 
     Thus, regarding multiple information processing devices  10  to be operated by the same user, even when one of the information processing devices  10  satisfies the locking condition due to a lapse of a predetermined period, the one information processing device  10  is kept from being locked as long as the user is operating another information processing device  10 . Thus, the user may continuously use the one information processing device  10 . In this way, the user does not have to perform a cumbersome unlocking operation and operability is improved as a consequence. 
     For example, in a circumstance (such as at home) where the information processing devices  10  are free from risk of being used by someone else and when the user conducts work and the like by using one information processing device  10  while looking at an electronic document such as a documented work instruction displayed on another one information processing device  10 , it is possible to use the other one information processing device  10  for displaying the electronic document without being locked. In other words, the work or the like of the user is not interrupted by the other one information processing device  10  being locked, and work efficiency is thus improved. 
     In this way, it is possible to maintain device security without the request to relax the locking condition applied to the other one information processing device  10 , such as increasing a set value for the predetermined period defined as the locking condition. As a consequence, it is possible to achieve security and convenience at the same time. 
     Based on the connection method between the determination target information processing device  10  and the own information processing device  10 , the search unit  102  determines that the determination target information processing device  10  is located near the own information processing device  10  when any one of the above-described conditions (a1) to (a3), (b1), and (b2) is met. 
     Specifically, the search unit  102  determines that the determination target information processing device  10  is located in the predetermined area from the own information processing device  10  if any one of the following conditions is met, namely, if the determination target information processing device  10  and the own information processing device  10  are wirelessly coupled to the same AP, if the determination target information processing device  10  is wirelessly coupled to the own information processing device  10  by short-distance wireless connection, if the determination target information processing device  10  is directly wire-connected to the own information processing device  10 , and if the determination target information processing device  10  and the own information processing device  10  are wire-coupled to the same router. 
     Thus, it is possible to determine whether or not another information processing device  10  is located near the own information processing device  10  without providing the information processing device  10  with hardware or the like for measuring the distance from the other information processing device  10 . 
     In the above-described embodiment, the search unit  102  determines whether or not the determination target information processing device  10  is located near the own information processing device  10  by determining whether or not any one of the above-described conditions (a1) to (a3), (b1), and (b2) is met. However, the configuration of the search unit  102  is not limited to the foregoing. 
     For instance, a router that combines a function as a wireless AP, a function as a wired LAN hub, and a function as a router has been used in recent years. The use of such a router may allow coexistence of a wirelessly coupled information processing device  10  and a wire-coupled information processing device  10  in the same network. 
     In this regard, when one of the own information processing device  10  and the determination target information processing device  10  is wire-coupled while the other one of the own information processing device  10  and the determination target information processing device  10  is wirelessly coupled, the search unit  102  may determine that the determination target information processing device  10  is located near the own information processing device  10  if the following condition (d1) is met. 
     (d1) If a gateway to which the determination target information processing device  10  is coupled is the same as a gateway to which the own information processing device  10  is coupled, the search unit  102  determines that the determination target information processing device  10  is located near the own information processing device  10 . 
     The wirelessly coupled information processing device  10  checks the IP address, the MAC address, and the like of the gateway serving as the connection destination by using the method discussed in the condition (a1). The wire-coupled information processing device  10  checks the IP address or the MAC address of the connection destination, the IP address or the MAC address of the gateway, or the like by using the method discussed in the condition (b2). By using these methods, it is possible to determine whether or not the gateways serving as the connection destinations are the same based on the IP addresses, the MAC addresses, and the like. 
     As described above, the search unit  102  may presume that the determination target information processing device  10  is located in the predetermined area from the own information processing device  10  and thus the determination target information processing device  10  is located near the own information processing device  10  when any one of the above-described conditions (a1) to (a3), (b1), (b2), and (d1) is met. 
     In the above-described embodiment, the search unit  102  determines that the determination target information processing device  10  is located in the predetermined area from the own information processing device  10  if any one of the following conditions is met, namely, if the determination target information processing device  10  and the own information processing device  10  are wirelessly coupled to the same AP, if the determination target information processing device  10  is wirelessly coupled to the own information processing device  10  by short-distance wireless connection, if the determination target information processing device  10  is directly wire-connected to the own information processing device  10 , and if the determination target information processing device  10  and the own information processing device  10  are wire-coupled to the same router. However, the configuration of the search unit  102  is not limited to the foregoing. 
     For instance, the information processing device  10  may be provided with a not-illustrated distance measurement device, and may determine whether or not the determination target information processing device  10  is located in the predetermined area from the own information processing device  10  by measuring the distance to the determination target information processing device  10  using the distance measurement device. 
     In the above-described embodiment, the in-operation state management unit  104  determines whether or not the own information processing device  10  is being operated by the user by determining whether or not any of the above-described conditions (c1) to (c3) is met. However, the configuration of the in-operation state management unit  104  is not limited to the foregoing. 
     For instance, conditions other than the conditions (c1) to (c3) may be used for determining whether or not the own information processing device  10  is being operated by the user, or two or more of these conditions may be used in combination for the determination. Thus, the determination may be made by applying appropriate modifications. 
     The above-described embodiment depicts the example in which the information indicating the locking condition is stored in each information processing device  10 . However, the configuration of the information processing device  10  is not limited to the foregoing. 
     The information indicating the locking condition may be provided to the own information processing device  10  or to another information processing device  10 . Alternatively, the computer system  1  may include a not-illustrated management server, and the management server may manage the locking condition. Thus, the management of the information indicating the locking condition may be made by applying appropriate modifications. 
     By providing the locking condition into the own information processing device  10 , the locking condition is kept from being distributed on the network  50 . This configuration has an advantage that it is possible to reduce a traffic amount on the network  50 . In addition, the processing by the lock processing unit  101  is also kept from being adversely affected by a data transfer delay on the network  50 . 
     By providing the locking condition to the management server, it is possible to consolidate the locking condition, for example. 
     A person skilled in the art may perform the lock control method and manufacture the information processing device according to the embodiment based on this disclosure. 
     All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although the embodiment of the present invention has been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.