Abstract:
An operation apparatus includes a communication section to communicate with an electronic apparatus capable of communicating, through a first transmission medium, with an accumulation apparatus capable of accumulating contents, the communication section communicating with the electronic apparatus through a second transmission medium, a content selection section to select a content to which a parental lock is to be set from among the contents accumulated in the accumulation apparatus, a release key setting section to set a key for releasing the parental lock for the content selected, a storage section to associate identification information of the content selected with the key set by the release key setting section and stores the identification information and the key associated with each other, and a parental lock notification section to notify the accumulation apparatus in which the content is accumulated of the identification information of the content to which the parental lock is set.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application is a continuation of U.S. patent application Ser. No. 12/653,040, filed on Dec. 8, 2009, which claims priority from Japanese Patent Application No. JP 2008-321873 filed in the Japanese Patent Office on Dec. 18, 2008, the entire contents of which are incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an operation apparatus capable of communicating, via a wireless medium, with an electronic apparatus capable of communicating, via a network, with an accumulation apparatus capable of accumulating contents, and to a content parental lock setting method by the operation apparatus. The present invention also relates to an electronic apparatus capable of communicating, via a network, with at least one accumulation apparatus capable of accumulating contents, and communicating with the operation apparatus via a wireless medium. 
     2. Description of the Related Art 
     In recent years, based on a DLNA (digital living network alliance), there has been structured a system that mutually connects, for example, digital AV (audiovisual) equipment or a PC (personal computer) with another in a home network environment as a local area network. With this structure, a content obtained through a broad band can be shared among family members and viewed in a home network environment, for example. That is, contents accumulated in various server apparatuses can be viewed by using various client apparatuses. As a result, for example, a situation in which a minor can easily view various contents beyond eyeshot of a parent or guardian may occur. 
     In view of this, there has been developed a technique in which a parental lock is set with respect to a content including an inappropriate image or audio that may give a bad influence to a minor (see, for example, Japanese Patent Application Laid-open No. 2008-236153 (paragraph 0026, FIG. 2) (hereinafter, referred to as Patent Document 1)). With the technique disclosed in Patent Document 1, restricted information for a content as a target of a parental lock setting is registered in a table for a parental lock, which is stored in a server apparatus. Upon reception of a content obtainment request from a client apparatus, the server apparatus judges whether restricted information is set for the content requested. When the restricted information is set for the content requested, the server apparatus does not transfer the content to the client apparatus. 
     SUMMARY OF THE INVENTION 
     With the technique disclosed in Patent document 1, a table for setting the parental lock for each server apparatus is created. Accordingly, in a case where there are a plurality of server apparatuses in a home network, it is necessary to set a parental lock with respect to a content for each server apparatus. This is a troublesome operation for a user. Further, for example, in a case where a minor has a PC in his/her own room, it may be substantially difficult for a parent or guardian to set a parental lock. 
     In view of the above-mentioned circumstances, it is desirable to provide an operation apparatus capable of communicating, via a wireless medium, with an electronic apparatus capable of communicating, via a network, with an accumulation apparatus capable of accumulating contents, and a parental lock setting method for contents by the operation apparatus. It is also desirable to provide an electronic apparatus capable of communicating, via a network, with at least one accumulation apparatus capable of accumulating contents and communicating, via a wireless medium, with the operation apparatus. 
     According to an embodiment of the present invention, there is provided an operation apparatus including a communication section, a content selection section, a release key setting section, a storage section, and a parental lock notification section. The communication section communicates with an electronic apparatus capable of communicating, through a first transmission medium, with an accumulation apparatus capable of accumulating contents, the communication section communicating with the electronic apparatus through a second transmission medium. The content selection section selects a content to which a parental lock is to be set from among the contents accumulated in the accumulation apparatus. The release key setting section sets a key for releasing the parental lock for the content selected. The storage section associates identification information of the content selected with the key set by the release key setting section and stores the identification information and the key associated with each other. The parental lock notification section notifies, through the electronic apparatus by using the communication section, the accumulation apparatus in which the content is accumulated of the identification information of the content to which the parental lock is set. 
     According to the embodiment of the present invention, the storage section of the operation apparatus associates the identification information of the content with the key for releasing the parental lock for the content and stores the identification information and the key associated with each other. As a result, it becomes possible for the operation apparatus to unify and manage the data related to the plurality of accumulation apparatuses. 
     In the embodiment, the operation apparatus further includes a name list obtainment section, an accumulation apparatus selection section, a content list obtainment section, and a list display section. The name list obtainment section requests to obtain a list of names of the accumulation apparatuses connected to the first transmission medium and obtains the list from the electronic apparatus by using the communication section. The accumulation apparatus selection section causes a user to select a name from the obtained list of the names of the accumulation apparatuses. The content list obtainment section requests the electronic apparatus by using the communication section to obtain a list of contents accumulated in the accumulation apparatus corresponding to the name selected and obtains the list of the contents. The list display section displays the obtained list of the contents to the user. The content selection section selects a content to which the parental lock is to be set from the displayed list of the contents. 
     According to the embodiment of the present invention, the user can obtain the list of the contents of each of the plurality of accumulation apparatuses connected to the network not from each of the plurality of accumulation apparatuses but from one operation apparatus. 
     In the embodiment, the parental lock notification section gives the electronic apparatus a notification including the identification information of the content and identification information of the accumulation apparatus that is a notification destination, to notify, through the electronic apparatus by using the communication section, the accumulation apparatus in which the content is accumulated of the identification information of the content to which the parental lock is set. 
     According to the embodiment of the present invention, it is possible to transmit the identification information of the content to any accumulation apparatus by using the one operation apparatus. 
     In the embodiment, the content list obtainment section transmits, to the electronic apparatus, a content list obtainment request including the identification information of the accumulation apparatus corresponding to the name selected, to request the electronic apparatus by using the communication section to obtain the list of the contents accumulated in the accumulation apparatus corresponding to the name selected and obtain the list of the contents. 
     According to the embodiment of the present invention, it is possible to obtain the list of the contents of any accumulation apparatus by using the one operation apparatus. 
     In the embodiment, the first transmission medium is a network, and the second transmission medium is a transmission medium independent of the network. 
     According to the embodiment of the present invention, the two-way communication is realized not between the operation apparatus and one accumulation apparatus but between the operation apparatus and the network. 
     In the embodiment, the operation apparatus further includes a parental lock release content selection section, a release key input section, and a parental lock release notification section. The parental lock release content selection section selects a content from which the parental lock is released. The release key input section causes the user to input a key for releasing the parental lock for the content selected. The parental lock release notification section notifies, when the key that is stored in the storage section with the key being associated with the content selected and the key that is input by the release key input section coincide, the accumulation apparatus in which the content is accumulated of a release of the parental lock for the content through the electronic apparatus by using the communication section. 
     According to the embodiment of the present invention, it is possible for the operation apparatus to unify and manage the release of the parental lock for the plurality of accumulation apparatuses. 
     In the embodiment, the operation apparatus further includes a backup processing section. The backup processing section transmits the identification information of the content and the key that are stored in the storage section with the identification information and the key being associated with each other to at least one of the accumulation apparatuses through the electronic apparatus by using the communication section and causes the accumulation apparatus to store, as a backup, the identification information and the key that are associated. 
     According to the embodiment of the present invention, even if the key for releasing the parental lock of the content which is stored in the operation apparatus is lost, the key is backed up by the accumulation apparatus, and therefore the safety is upgraded. 
     In the embodiment, the accumulation apparatus connected to the network includes a plurality of accumulation apparatuses. The operation apparatus further includes a move content selection section and a content move processing section. The move content selection section selects a content that is moved among the plurality of accumulation apparatuses. The content move processing section requests, when the key that is stored in the storage section with the key being associated with the content selected and the key that is input by the release key input section coincide, the plurality of accumulation apparatuses to cause the content to move, through the electronic apparatus by using the communication section. 
     According to the embodiment of the present invention, it is possible for the one operation apparatus to perform the move operation of the content from one accumulation apparatus to another accumulation apparatus. 
     In the embodiment, the operation apparatus further includes a parental lock resetting section. The parental lock resetting section sets whether the parental lock is set to the content accumulated in the accumulation apparatus to which the content is moved. 
     According to the embodiment of the present invention, it is possible for the one operation apparatus to perform the operation of setting whether the parental lock is set with respect to the content as the move destination. 
     According to another embodiment of the present invention, there is provided a content parental lock setting method of managing a parental lock with respect to contents by using an operation apparatus capable of communicating with at least one of electronic apparatuses capable of communicating with an accumulation apparatus capable of accumulating the contents through a first transmission medium, the operation apparatus capable of communicating with the at least one electronic apparatus through a second transmission medium. The content parental lock setting method includes selecting a content to which the parental lock is to be set from among the contents accumulated in the accumulation apparatus, setting a key for releasing the parental lock for the content selected, associating identification information of the content selected and the key set and storing the identification information and the key that are associated with each other, and notifying, through the electronic apparatus, the accumulation apparatus in which the content is accumulated of the identification information of the content to which the parental lock is set. 
     According to the embodiment of the present invention, the operation apparatus associates the identification information of the content and the key for releasing the parental lock for the content and stores the identification information and the key associated with each other. As a result, it is possible for the operation apparatus to unify and manage the information relating to the plurality of accumulation apparatuses. 
     According to another embodiment of the present invention, there is provided an electronic apparatus capable of communicating with one or more accumulation apparatuses capable of accumulating contents through a first transmission medium and capable of communicating with the operation apparatus through a second transmission medium. The electronic apparatus includes a name list relay section, a content list relay section, and a content identification information relay section. The name list relay section receives, from the operation apparatus through the second transmission medium, a request to obtain a list of names of the accumulation apparatuses connected to the first transmission medium, inquires of the accumulation apparatuses the names of the accumulation apparatuses based on the request, and transmits the list of the names of the accumulation apparatuses obtained from the accumulation apparatuses to the operation apparatus through the second medium. The content list relay section receives, from the operation apparatus through the second transmission medium, a request to obtain a list of contents accumulated in one of the accumulation apparatuses which corresponds to a name selected from the list of the names, receives the list of the contents from the accumulation apparatus based on the request, and transmits the list of the contents to the operation apparatus through the second transmission medium. The content identification information relay section receives, from the operation apparatus through the second transmission medium, a notification including identification information of the contents and identification information of the accumulation apparatus that is a notification destination and transmits identification information of a content to which a parental lock is set to the accumulation apparatus in which the contents are accumulated. 
     According to the embodiment of the present invention, the electronic apparatus includes the relay section between the operation apparatus and the accumulation apparatuses, and therefore the two-way communication is realized not between the operation apparatus and one accumulation apparatus but between the operation apparatus and the network. 
     As described above, according to the operation apparatus and the content parental lock setting method of the embodiments of the present invention, it is possible to communicate, through the wireless medium, with the electronic apparatus capable of communicating, through the network, with the accumulation apparatuses capable of accumulating the contents, with the result that the parental lock can be easily and reliably set. According to the electronic apparatus of the embodiment of the present invention, it is possible to communicate, through the network, with the one or more accumulation apparatuses capable of accumulating the contents, and it is possible to communicate with the operation apparatus through the wireless medium. As a result, the two-way communication is realized not between the operation apparatus and the one accumulation apparatus but between the operation apparatus and the network. 
     These and other objects, features and advantages of the present invention will become more apparent in light of the following detailed description of best mode embodiments thereof, as illustrated in the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a diagram showing an overall structure of a content management system according to an embodiment of the present invention; 
         FIG. 2  is a block diagram showing a hardware structure of a client apparatus; 
         FIG. 3  is a block diagram showing a hardware structure of a server apparatus; 
         FIG. 4  is a block diagram showing a hardware structure of a remote controller; 
         FIG. 5  is a diagram showing a software structure of the client apparatus; 
         FIG. 6  is a diagram showing a software structure of the server apparatus; 
         FIG. 7  is a diagram showing a software structure of the remote controller; 
         FIG. 8  is a flowchart showing an operation of setting a parental lock by the content management system; 
         FIG. 9  is a diagram showing sets of apparatus IDs and server names predetermined; 
         FIG. 10  is a diagram showing a server list table; 
         FIG. 11  is a diagram showing a server selection screen; 
         FIG. 12  is a diagram showing a content list table; 
         FIG. 13  is a diagram showing a content management table; 
         FIG. 14  is a diagram showing a content selection screen; 
         FIG. 15  is a diagram showing a menu screen; 
         FIG. 16  is a diagram showing a parental unlock code input screen; 
         FIG. 17  is another diagram showing the content management table; 
         FIG. 18  is another diagram showing the content list table; 
         FIG. 19  is a diagram showing a user interface that indicates completion of the setting of the parental lock; 
         FIG. 20  is another diagram showing the content list table; 
         FIG. 21  is a flowchart showing a setting release operation of the parental lock by the content management system; 
         FIG. 22  is a flowchart showing a move operation of a content by the content management system; 
         FIG. 23  is another diagram showing the content management table; 
         FIG. 24  is another diagram showing the content management table; 
         FIG. 25  is a diagram showing a dialog screen; and 
         FIG. 26  is a flowchart showing a reproduction operation of a content by the content management system. 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 
     (Structure of Content Management System  100 ) 
       FIG. 1  is a diagram showing an overall structure of a content management system  100  according to an embodiment of the present invention. 
     The content management system  100  includes at least one client apparatus  500  and a plurality of server apparatuses  600  ( 600   a ,  600   b ). The client apparatus  500  and each of the plurality of server apparatuses are connected with each other via a home network  200  serving as a local area network so as to communicate with each other. 
     It should be noted that in this embodiment, the plurality of server apparatuses are referred to as the server apparatus  600  when collectively treated with no distinction or referred to as the server apparatus  600   a  or  600   b  when individually treated. 
     A remote controller  400  can perform two-way communication with at least the client apparatus  500  out of the client apparatus  500  and the server apparatus  600 . 
     The server apparatus  600  of this embodiment can record and reproduce content data of programs momentarily broadcasted by broadcast stations, such as terrestrial digital broadcasting, CS digital broadcasting, and BS digital broadcasting. The server apparatus  600  can deliver content data to the client apparatus  500  via the home network  200 . 
     The client apparatus  500  includes a display screen and a speaker. Therefore, when receiving content data delivered from the server apparatus  600  via the home network  200 , the client apparatus  500  can display an image of the data on the display screen or output audio of the data from the speaker. 
     (Hardware Structure of Client Apparatus  500 ) 
     A description will be given on the client apparatus  500 .  FIG. 2  is a block diagram showing a hardware structure of the client apparatus  500 . 
     As shown in  FIG. 2 , to a CPU (central processing unit)  501 , a ROM (read only memory)  503 , a RAM (random access memory)  504 , an input operation section  505 , and a display section  506  are connected via a system bus  502 . Further, an audio output section  507 , a network connection section  508 , a decode section  509 , a broadcast reception section  510 , and an optical communication section  511  are connected to the CPU  501  via the system bus  502 . 
     The input operation section  505  includes various keys or the like. A user processes inputs of various commands or data with the input operation section  505 . The commands input by the user with the input operation section  505  are supplied to the CPU  501  via the system bus  502  with an input interface section (not shown). 
     The display section  506  is constituted of a display device including a display screen such as an LCD (liquid crystal display) and a display control circuit that drives the display device, for example. The audio output section  507  is constituted of a circuit that converts a digital audio signal to an analog audio signal, a speaker, and the like. 
     The network connection section  508  processes wire or wireless connection with the home network  200 . To the home network  200 , the server apparatus  600  is linked through wire or wireless connection. 
     The broadcast reception section  510  receives broadcast waves of the terrestrial digital broadcasting, CS digital broadcasting, BS digital broadcasting, or the like, which are delivered from each broadcast station  300 , and demodulates a video signal and an audio signal, for example. 
     The decode section  509  decodes content data read from a storage section  512  and recovers digital video data and digital audio data. The recovered digital video data is supplied to the display section  506  via the system bus  502  and displayed. The recovered digital audio data is supplied to the audio output section  507  via the system bus  502  and output as audio from the speaker. 
     The optical communication section  511  is an interface for processing the two-way communication with the remote controller  400 . Specifically, the optical communication section  511  communicates with an external apparatus by using light such as an infrared ray as a wireless medium. In addition to light, another wireless medium such as a radio wave, a sound wave, and an electromagnetic wave may be used. 
     The ROM  503  is a read-only memory that permanently stores programs or data for software processing to be executed by the client apparatus  500 . It is to be noted that the program may be stored in the storage section  512 . The ROM  504  is a writable volatile memory used for loading a program code executed by the CPU  501  or writing work data of the program. The CPU  501  performs overall control on the respective sections mentioned above and controls exchange of data between the sections. In addition, in order to execute the software processing to be executed by the client apparatus  500 , the CPU  501  loads the program from the storage section  512  or the ROM  503  to the RAM  504  and interprets and executes the program. 
     (Hardware Structure of Server Apparatus  600 ) 
     Next, a description will be given on the server apparatus  600 .  FIG. 3  is a block diagram showing a hardware structure of the server apparatus  600 . 
     As shown in  FIG. 3 , to a CPU  601 , a ROM  603 , a RAM  604 , an input operation section  605 , and a display section  607 , a network connection section  608 , and a decode section  609  are connected via a system bus  602 . Further, a broadcast reception section  611 , a storage section  613  formed of an HDD (hard disk drive) or the like, and a media interface section  614  are connected to the CPU  601  via the system bus  602 . 
     The input operation section  605  includes various keys or the like and processes inputs of various commands for record and reproduction from the user. The commands input with the input operation section  605  are transmitted to the CPU  601  via the system bus  602  with an input interface section (not shown). 
     The display section  607  is constituted of a display device including a display screen such as an LCD and a display control circuit that drives the display device, for example. The display section  607  displays confirmation of the commands or data input by the user or various statuses, for example. 
     The broadcast reception section  611  receives broadcast waves of the terrestrial digital broadcasting, CS digital broadcasting, BS digital broadcasting, or the like, which are delivered from each broadcast station  300  and demodulates a video signal and an audio signal, for example. 
     The network connection section  608  processes connection with the home network  200 . The network connection section  608  processes inputs or outputs of the video signal and the audio signal between the network connection section  608  and the client apparatus  500  connected to the server apparatuses  600  via the home network  200 . 
     The decode section  609  decodes content data read from the storage section  613  and recovers video data and audio data. The recovered digital video data is supplied to the network connection section  608  via the system bus  602  and output to the client apparatus  500  connected to the network connection section  608 . 
     The storage section  613  is formed of the HDD or the like. The content data of a broadcast program or the like that is encoded by an encode section  610 , a content management table (described below), and the like are recorded on the storage section  613 . 
     To the media interface section  614 , a removable medium  2  such as an optical disc can be loaded. The content data of the broadcast program or the like can be recorded on the removable medium  2 . Examples of the removable medium  2  include a recordable or rewritable DVD (digital versatile disc) and a Blu-ray. 
     In the ROM  603 , a program or the like for software processing to be executed by the server apparatus  600  is stored. The ROM  604  is a writable volatile memory used for loading a program code executed by the CPU  601  or for writing work data of the program. In addition, in order to execute the software processing to be executed by the server apparatus  600 , the CPU  601  loads the program from the ROM  603  to the RAM  604  and interprets and executes the program. 
     (Hardware Structure of Remote Controller  400 ) 
     Next, with reference to  FIG. 4 , a hardware structure of the remote controller  400  will be described.  FIG. 4  is a block diagram showing the hardware structure of the remote controller  400 . 
     As shown in  FIG. 4 , the remote controller  400  is constituted of a CPU  401 , an optical communication section  402 , a storage section  403 , a display section  404 , and an input operation section  405 . 
     The optical communication section  402  is an interface that selectively performs two-way optical communication with the client apparatus  500 . More specifically, in a case where there are a plurality of client apparatuses  500 , the optical communication section  402  selects a communication target from among the client apparatuses  500 , and the optical communication section  402  can input various operation signals for remote control to the selected client apparatus  500  and receive various data from the selected apparatus. In addition to light, another wireless medium such as a radio wave, a sound wave, and an electromagnetic wave may be used. 
     The display section  404  displays an operation method of the input operation section  405  for performing remote control on the client apparatus  500  and displays to the user a list of apparatuses  600  and a list of contents that can be obtained from the individual server apparatuses  600 . 
     The input operation section  405  has a plurality of keys, and serves as a user interface that receives an input of, for example, various operation signals and selection from the list by the user and notifies the CPU  401  of the input. It should be noted that the keys of the input operation section  405  may be touch-sensitive keys displayed on a screen of the display section  404 . 
     The storage section  403  stores various tables and the like created based on information obtained from the respective server apparatuses through the client apparatus  500 . 
     (Software Structure of Client Apparatus  500 ) 
     Next, a software structure of the client apparatus  500  will be described with reference to  FIG. 5 .  FIG. 5  is a diagram showing the software structure of the client apparatus  500 . 
     As shown in  FIG. 5 , the client apparatus  500  includes a content data obtainment section  524 , a content reproduction section  526 , a server list processing section  541 , and a list relay section  543 . 
     The content data obtainment section  524  selectively obtains content data sent from the server apparatus  600  via the home network  200  or content data such as the broadcast programs received at the broadcast reception section  510  of the client apparatus  500 , and supplies the obtained data to the content reproduction section  526 . 
     The content reproduction section  526  decodes the content data supplied from the content data obtainment section  524  by using the decode section  509  and recovers the digital video data and the digital audio data. The content reproduction section  526  outputs the recovered digital video data to the display section  506  to cause the display section  506  to display the digital video data, and outputs the digital audio data to the audio output section  507  to cause the audio output section  507  to output the digital audio data. 
     The server list processing section  541  transmits a request C1 of inquiring a server name to the server apparatuses  600  connected to the home network  200  via the home network  200 . Further, the server list processing section  541  receives a request R1 (described below) from the remote controller  400  and transmits, to the remote controller  400 , a response C5 including a server list in which apparatus IDs previously assigned to each server apparatus  600  and server names predetermined are put together. 
     The list relay section  543  receives a content list obtainment request R6 from the remote controller  400  and transmits, to the server apparatus  600 , a content list obtainment request C6 via the home network  200 . 
     It should be noted that in this embodiment, a television or a personal computer is considered as an example of the client apparatus  500 , but the client apparatus  500  of this embodiment of the present invention is not limited to those apparatuses and may have any form as long as it includes the elements shown in  FIGS. 2 and 5 . 
     (Software Structure of Server Apparatus  600 ) 
     Next, a software structure of the server apparatus  600  will be described with reference to  FIG. 6 .  FIG. 6  is a diagram showing the software structure of the server apparatus  600 . 
     As shown in  FIG. 6 , the server apparatus  600  includes a content data obtainment section  623 , a content data storage section  624 , a reproduction processing section  626 , a server name response section  630 , a content list processing section  631 , a content list storage section  632 , and a parental lock processing section  633 . The server apparatus  600  further includes a move processing section  634 . Here, the content data storage section  624  and the content list storage section  632  are set in the storage section  613  or the removable medium  2  or the like loaded to the media interface section  614 . 
     The content data obtainment section  623  selectively receives content data of a broadcast program or the like that is broadcasted from the broadcast station  300  and registers the received content data in the content data storage section. 
     The reproduction processing section  626  performs a processing so that corresponding content data is read from the content data storage section  624 , the content data is decoded by the decode section  609 , and the recovered digital video data and digital audio data are supplied to the network connection section  608 . 
     Upon reception on the request C1 from the client apparatus  500 , the server name response section  630  creates a set of an apparatus ID previously assigned to the server apparatus to which the server name response section  630  belongs (which will be referred to as the server apparatus itself) and a server name predetermined, and transmits a response S1 including the set to the client apparatus  500 . 
     The content list processing section  631  receives the content list obtainment request C6 from the client apparatus  500 , reads sets of content IDs and titles of programs from the content data storage section  624 , and creates a content list table including the sets. The content list processing section  631  transmits a response S2 including the content list including the sets of the content IDs and the titles of programs to the client apparatus  500  via the home network  200 . 
     The parental lock processing section  633  receives a parental lock setting request C8 including sets with content IDs and titles of programs from the client apparatus  500 , creates a parental lock list table, and stores the created parental lock list table in the content list storage section  632 . Further, the parental lock processing section  633  transmits a parental lock setting completion notification S3 to the client apparatus  500  via the home network  200 . 
     The move processing section  634  receives a move request C12 from the client apparatus  500  via the home network  200 . The move processing section  634  performs a predetermined operation for moving a content from the apparatus itself to another server apparatus  600 . When the move operation is over, the move processing operation  634  sends a move completion notification to the content list processing section  631  and sends the move completion notification to the server apparatus  600 . 
     (Software Structure of Remote Controller  400 ) 
     Next, a software structure of the remote controller  400  will be described with reference to  FIG. 7 .  FIG. 7  is a diagram showing the software structure of the remote controller  400 . 
     The remote controller  400  includes a server list processing section  410 , a server list storage section  411 , a UI (user interface) processing section  412 , a content list processing section  413 , a content list storage section  414 , a parental lock processing section  415 , and a move processing section  416 . Here, the server list storage section  411  and the content list storage section  414  are set to the storage section  403 . 
     The server list processing section  410  transmits, to the client apparatus  500 , the request R1 including a list of the apparatus IDs and the server names, and receives the response C5 including a server list of the apparatus IDs and the server names from the client apparatus  500 . 
     The UI processing section  412  supplies various display requests (described below) to the display section  404  and causes the display device to display various display screens corresponding to the display requests. 
     The content list processing section  413  transmits to the content list obtainment request R6 to the client apparatus  500  and receives a response C7 including a content list in which sets of content IDs and titles of programs are put together. Based on the content IDs and the titles of the programs that are included in the response C7 received, the content list processing section  413  registers them in the content management table stored in the content list storage section  414 . 
     The parental lock processing section  415  receives a parental lock setting completion notification C9 from the client apparatus  500  and outputs a parental lock setting completion notification R18 to the UI processing section  412 . In addition, the parental lock processing section  415  creates a set of a parental lock, a content ID, and an apparatus ID, with respect to which the parental lock is set, and transmits a parental lock setting notification R17 including the set created to the client apparatus  500 , for example. 
     The move processing section  416  is used when the content is moved between the server apparatuses  600 . The move processing section  416  receives a move destination notification R28 from the UI processing section  412  and transmits a move request R29 to the client apparatus  500 . 
     It should be noted that a remote controller for home electronics, which is capable of performing the two-way communication, is considered as an example of the remote controller  400  of this embodiment, but the remote controller  400  of this embodiment of the present invention is not limited to this example and may have any form as long as it includes the elements shown in  FIGS. 4 and 7 . For example, the remote controller  400  may be a cellular phone capable of performing two-way infrared communication. 
     (Setting Operation of Parental Lock by Content Management System  100 ) 
     Next, a description will be given on a setting operation of the parental lock by the content management system  100  with reference to  FIG. 8 .  FIG. 8  is a flowchart showing an operation of setting the parental lock by the content management system  100 . 
     As shown in  FIG. 8 , when the user performs an operation on the client apparatus  500  for starting up the client apparatus  500 , the client apparatus  500  is started up (Step S 101 ). Further, when the user performs an operation on the server apparatus  600  for starting up the server apparatus  600 , each of the server apparatus  600  is started up (Step S 102 ). 
     When started up, the client apparatus  500  causes the server list processing section  541  to start up. The server list processing section  541  transmits, via the home network  200 , the request C1 of inquiring a server name to each of the server apparatuses  600  connected to the home network  200  (Step S 103 ). 
     On the other hand, when started up, the server apparatuses  600  connected to the home network  200  cause the server name response sections  630  to start up, respectively. Upon reception of the request C1 from the server list processing section  541  of the client apparatus  500 , the server name response sections  630  of the respective server apparatuses  600  each create a set of an apparatus ID  701  previously assigned to each of the server apparatuses themselves and a server name  702  predetermined (shown in  FIG. 9 ). The server name response sections  630  of the server apparatuses  600  each transmit, to the client apparatus  500  via the home network  200 , the response S1 including the set of the apparatus ID  701  and the server name  702  that are created (Step S 104 ). 
     The server list processing section  541  of the client apparatus  500  receives the response S1 including the set of the apparatus ID  701  previously assigned to each of the apparatuses and the server name  702  predetermined from each of the server apparatuses  600  via the home network  200  (Step S 105 ). Next, the server list processing section  541  creates a server list of the sets included in each of the responses S1 received from the server apparatuses  600  (Step S 106 ). 
     On the other hand, the server list processing section  410  of the remote controller  400  transmits the request R1 including the sets of the apparatus IDs  701  and the server names  702  to the client apparatus  500  by using the optical communication section  402  (Step S 107 ). 
     The server list processing section  541  of the client apparatus  500  receives the request R1 including the sets of the apparatus IDs  701  and the server names  702  from the server list processing section  410  of the remote controller  400  by using the optical communication section  511 . The server list processing section  541  that has received the request R1 including the sets of the apparatus IDs  701  and the server names  702  transmits the response C5 including the server list in which the apparatus IDs  701  and the server names  702  are put together to the remote controller  400  by using the optical communication section  511  (Step S 108 ). 
     The server list processing section  410  of the remote controller  400  receives the response C5 including the server list of the apparatus IDs  701  and the server names  702  from the server list processing section  541  of the client apparatus  500  (Step S 109 ). Upon reception of the response C5 including the server list of the apparatus IDs  701  and the server names  702 , the server list processing section  410  creates a server list table  710  based on the obtained server list and stores the server list table  710  in the server list storage section  411  (Step S 110 ). 
     As shown in  FIG. 10 , the server list table  710  is a table having an apparatus ID field  711  and a server name field  712 . For each record of the server list table  710 , the apparatus ID  701  is registered in the apparatus ID field  711 , and the server name  702  is registered in the server name field  712 . The apparatus IDs  701  and the server names  702  are associated with each other. 
     On the other hand, the UI processing section  412  reads the server name  702  registered in the server list table  710  from the server list table  710  stored in the server list table storage section  411 . The UI processing section  412  creates a server selection screen  800  (shown in  FIG. 11 ) that indicates a list of the server names  702  based on the read server names  702 . The UI processing section  412  supplies, to the display section  404 , a display request R4 including display data of the server selection screen  800  that indicates the list of the server names  702  (Step S 111 ). 
     As shown in  FIG. 11 , the server selection screen  800  serves as a user interface for displaying the list of the server names  702  and causing the user to select any one from the server apparatuses  600 . In the example of  FIG. 11 , the list of the names of the server apparatuses  600  such as “Living Room 1”, “Network HDD”, and “Juke Box” is displayed on the server selection screen  800 . 
     The display section  404  receives the display request R4 including display data of the server selection screen  800  from the UI processing section  412  and displays the server selection screen  800  on the display screen thereof. The user references the server names of the server selection screen  800  displayed on the display section  404  and selects one (server apparatus  600   a ) from among the server apparatuses  600  by using the input operation section  405 . The input operation section  405  supplies, to the UI processing section  412 , a server selection request R5 including selection information of the server name selected by the user. Upon reception of the server selection request R5, the UI processing section  412  supplies the server selection request R5 to the content list processing section  413  (Step S 112 ). 
     Upon reception of the server selection request R5 from the UI processing section  412 , the content list processing section  413  reads an apparatus ID of the server apparatus  600   a  corresponding to the server name from the server list table  710  based on the selection information of the server name included in the server selection request R5. The content list processing section  413  transmits the content list obtainment request R6 including the read apparatus ID  701  to the client apparatus  500  by using the optical communication section  511  (Step S 113 ). 
     The list relay section  543  of the client apparatus  500  receives the content list obtainment request R6 from the content list processing section  413  of the remote controller  400  (Step S 114 ). The list relay section  543  transmits, via the home network  200 , the content list obtainment request C6 to the server apparatus  600   a  to which the apparatus ID included in the content list obtainment request R6 is previously assigned (Step S 115 ). 
     The content list processing section  631  of the server apparatus  600   a  receives the content list obtainment request C6 from the list relay section  543  of the client apparatus  500  via the home network  200 . Upon reception of the content list obtainment request C6, the content list processing section  631  sets a content list table to the content list storage section  632 . The content list processing section  631  extracts the content IDs and the titles of the programs of all the contents stored in the content data storage section  624  from SI (service information) information. The content list processing section  631  registers the extracted information in a content list table  720  provided for the content list storage section  632  (Step S 116 ). 
     As shown in  FIG. 12 , the content list table  720  is constituted of a content ID field  721 , a program title field  722 , and a parental lock flag field  733 . Information items registered in those fields  721 ,  722 , and  733  are information for each server apparatus and associated with each other. The parental lock flag refers to a flag for setting of whether parental lock is set for a content. An initial value of the parental lock flag is “without parental lock”. It should be noted that the SI information is information periodically distributed by a content distributor via a network, and the server apparatuses  600  each receive the SI information and always have latest SI information. The SI information includes various information items relating to the content, such as a content ID, a title of a program, a distribution time, and details of a program. 
     Next, the content list processing section  631  of the server apparatus  600   a  creates a content list including the content IDs and the titles of the programs of all the contents in the content list table  720 . The content list processing section  631  of the server apparatus  600   a  transmits the response S2 including the created content list to the client apparatus  500  via the home network  200  (Step S 117 ). 
     The list relay section  543  of the client apparatus  500  receives the response S2 including the content list from the server apparatus  600   a  via the home network  200  (Step S 118 ). The list relay section  543  transmits, to the remote controller  400  by using the optical communication section  511 , the response S2 including the content list received from the server apparatus  600   a  as the response C7 (Step S 119 ). 
     The content list processing section  413  of the remote controller  400  receives the response C7 including the content list from the list relay section  543  of the client apparatus by using the optical communication section  402  (Step S 120 ). The content list processing section  413  sets a content management table  730  to the content list storage section  414  and registers, in the content management table  730 , the content IDs and the titles of the programs in the content list included in the response C7 received from the client apparatus  500  (Step S 121 ). 
     As shown in  FIG. 13 , the content management table  730  is constituted of a content ID field  731 , a program title field  732 , a parental lock flag field  733 , a parental unlock code field  734 , and an apparatus ID filed  736 . 
     The UI processing section  412  of the remote controller  400  reads all the program titles registered in the content management table  730  from the content list storage section  414  (R8). The UI processing section  412  creates display data of a content selection screen  810  including the content list of all the program titles read and supplies a display request R9 including the display data of the content selection screen  810  to the display section  404  (Step S 122 ). As a result, the content selection screen  810  is displayed on the screen of the display section  404 . 
     As shown in  FIG. 14 , the content selection screen  810  serves as a user interface for displaying a list of the program titles of all the contents accumulated in the server apparatus selected by the user and causing the user to select any one from the contents. 
     The user uses the input operation section  405  to select a content with respect to which the user wants to perform reproduction or set the parental lock from among the program titles displayed on the content selection screen  810 . The input operation section  405  supplies selection information R10 of the program title to the UI processing section  412  (Step S 123 ). 
     It should be noted that in this embodiment, the content selection screen  810  or various screens (described below) are displayed on the display screen of the remote controller  400 , but where to display those screens is not limited to this case. Those screens may be displayed on the display device of the display section  506  of the client apparatus  500 . 
     Upon reception of the selection information R10 from the input operation section  405 , the UI processing section  412  creates display data of a menu screen  801  (shown in  FIG. 15 ) as a list of processings that can be performed on the content of the program title selected. Further, the UI processing section  412  supplies a display request R11 including the display data of the menu screen  801  to the display section  404  (Step S 124 ). As a result, the menu screen  801  is displayed on the screen of the display section  404 . 
     As shown in  FIG. 15 , the menu screen  801  serves as a user interface for displaying a list of processing commands that can be executed with respect to the selected content and causing the user to select a processing command that has to be executed with respect to the selected content. On the menu screen  801 , character strings that indicate the processing commands to be executed with respect to the content, such as “reproduction”, “parental lock”, and “move”, are displayed. The “reproduction” refers to a processing of reproducing data of the content held by the server apparatus  600  by the client apparatus  500 , and the “parental lock” refers to a processing of setting the parental lock with respect to the content. The “move” refers to a processing of moving the content from one server apparatus  600  to another. 
     A description will be given on a case where the execution of the processing of the “parental lock” is specified to the menu screen  801  by the user by using the input operation section  405 . In this case, the input operation section  405  supplies selection information R12 of the processing of the “parental lock” to the UI processing section  412  (Step S 125 ). 
     Upon reception of the selection information R12 of the processing of the “parental lock” from the input operation section  405 , the UI processing section  412  subsequently creates display data of a parental unlock code input screen  802  (shown in  FIG. 16 ) and supplies a display request R13 including the display data to the display section  404 . As a result, the parental unlock code input screen  802  is displayed on the screen of the display section  404 . 
     As shown in  FIG. 16 , the parental unlock code input screen  802  serves as a user interface for causing the user to input a code necessary for releasing the parental lock that is set to the content. On the parental unlock code input screen  802 , a message for guiding the user, e.g., “input parental unlock code”, input boxes of, e.g., a four-digit parental unlock code, and the like are displayed. 
     The user references the parental unlock code input screen  802  displayed on the display section  404  and inputs the parental unlock code by using the input operation section  405 . The input operation section  405  supplies a parental unlock code R14 input by the user to the UI processing section  412 . 
     Upon reception of the parental unlock code R14 from the input operation section  405 , the UI processing section  412  causes the parental unlock code to be displayed on the parental unlock code input screen  802  of the display section  404  (Step S 126 ). 
     Further, the UI processing section  412  supplies a parental lock setting request including the parental unlock code to the parental lock processing section  415 . Upon reception of the parental lock setting request from the UI processing section  412 , the parental lock processing section  415  performs registration in the content management table  730  stored in the content list storage section  414  as follows. 
     For example, as shown in  FIG. 17 , the parental lock processing section  415  sets a value corresponding to “with parental lock” as the parental lock flag to the parental lock flag field  733  that belongs to a record  735  in the content management table  730 , and registers a parental unlock code in the parental unlock code field  734  that also belongs to the record  735  (Step S 127 ). 
     When the registration in the content management table  730  is over, the parental lock processing section  415  transmits, to the client apparatus  500  by using the optical communication section  402 , the parental lock setting notification R17 including the set of the apparatus ID and the content ID to which the parental lock is set (Step S 128 ). 
     The list relay section  543  of the client apparatus  500  receives the parental lock setting notification R17 including the set of the apparatus ID and the content ID to which the parental lock is set from the remote controller  400  by using the optical communication section  511  (Step S 129 ). 
     Upon reception of the parental lock setting notification R17, the list relay section  543  transmits the parental lock setting request C8 including the content ID included in the parental lock setting notification R17 to the server apparatus  600   a  corresponding to the apparatus ID included in the parental lock setting notification R17 (Step S 130 ). 
     Upon reception of the parental lock setting request C8 from the client apparatus  500 , the parental lock processing section  633  of the server apparatus  600   a  updates the content list table  720  stored in the content list storage section  632  based on the parental lock setting request C8 (Step S 131 ). 
     Specifically, as shown in  FIG. 18 , into the parental lock flag field  733  corresponding to the content ID included in the parental lock setting request C8, a value corresponding to “with parental lock” is set as the parental lock flag. 
     After that, the parental lock processing section  633  transmits the parental lock setting completion notification S3 to the client apparatus  500  via the home network  200  (Step S 132 ). 
     Upon reception of the parental lock setting completion notification S3 from the server apparatus  600   a  (Step S 133 ), the list relay section  543  of the client apparatus  500  transmits the parental lock setting completion notification C9 to the remote controller  400  by using the optical communication section  511  (Step S 134 ). 
     Upon reception of the parental lock setting completion notification C9 from the client apparatus  500  (Step S 135 ), the parental lock processing section  415  of the remote controller  400  outputs the parental lock setting completion notification R18 to the UI processing section  412 . 
     The UI processing section  412  receives the parental lock setting completion notification R18 from the parental lock processing section  415 . The UI processing section  412  creates display data of the content corresponding to the content ID included in the parental lock setting completion notification R18 and supplies the display data to the display section  404  (Step S 136 ). It should be noted that in the display data, a graphic symbol indicating that the parental lock is already set is added to the column in which the program title is displayed on the content selection screen  810 . As a result, the content selection screen  810  displayed on the display section  404  is updated as shown in  FIG. 19 , for example. In this way, a graphic symbol  811  indicating that the parental lock is already set is added to the column of displaying the program titles corresponding to the content to which the parental lock is set. The above is the description on the parental lock setting with respect to the specific content. 
     In a case where the parental lock is subsequently set with respect to another server apparatus  600   b , the process of Steps S 112  to S 136  only has to be performed again. 
     That is, the user references the server selection screen  800  displayed on the display section  404  and selects the server apparatus  600   b  by using the input operation section  405 . For example, in a case where the user selects a server name “Living Room 1” by using the input operation section  405 , the input operation section  405  supplies the server selection request R5 including selection information of a processing for the server name “Living Room 1” selected by the user to the UI processing section  412 . Upon reception of the server selection request R5 from the input operation section  405 , the UI processing section  412  supplies the server selection request R5 to the content list processing section  413  (Step S 112 ). 
     Upon reception of the server selection request R5 from the UI processing section  412 , the content list processing section  413  reads an apparatus ID of the server apparatus  600   b  corresponding to the server name from the server list table  710  based on the selection information of the server name included in the server selection request R5. The content list processing section  413  transmits the content list obtainment request R6 including the read apparatus ID  701  to the client apparatus  500  by using the optical communication section  511  (Step S 113 ). 
     The list relay section  543  of the client apparatus  500  receives the content list obtainment request R6 from the content list processing section  413  of the remote controller  400  (Step S 114 ). The list relay section  543  transmits, via the home network  200 , the content list obtainment request C6 to the server apparatus  600   b  to which the apparatus ID included in the content list obtainment request R6 is previously assigned (Step S 115 ). 
     The content list processing section  631  of the server apparatus  600   b  receives the content list obtainment request C6 from the list relay section  543  of the client apparatus  500  via the home network  200 . Subsequent operations are the same as those of Steps S 116  to S 136  described above. 
     By the setting operation of the parental lock described above, the content list storage section  414  of the remote controller  400  holds the content management table  730  in which the information (such as the program titles) on the contents accumulated in each of the server apparatuses  600 , the parental lock flag indicating whether the parental lock is set, and the code for releasing the parental lock are registered. That is, it is possible to unify and manage the information relating to the parental lock setting with respect to the contents accumulated in the server apparatuses  600  by the remote controller  400 , with the result that convenience for the user is improved. In addition, in a case where a minor has the server apparatus  600  in his/her own room, it is also possible to remotely set the parental lock by a parent or guardian by using the remote controller  400 , for example. 
     It should be noted that in this embodiment, only the content list storage section  414  of the remote controller  400  holds the content management table  730  in which the parental unlock code is registered. On the other hand, in the content list table  720  stored in the content list storage section  632  of the server apparatus  600 , the parental unlock code is not registered, and a flag indicating whether the parental lock is set is only set. However, the present invention is not limited to this example. Another content list table  720  may be created, and the parental unlock code may be corresponded to a flag and registered in the content list table  720 . In this case, the user of the server apparatus  600  is not allowed to access the parental unlock code registered in the content list table  720  created. 
       FIG. 20  shows a structure of the content list table  720  used in this case. As shown in  FIG. 20 , the content list table  720  has a structure that includes the parental unlock field  734  in addition to the content ID field  721 , the program title field  722 , and the parental lock flag field  733 . 
     In Step S 128 , when the registration in the content management table  730  is over, the parental lock processing section  415  transmits the parental lock setting notification R17 including the set of the apparatus ID, the content ID, with/without the parental lock, and the parental unlock code, as the information newly registered in the content management table  730 . 
     In Step S 129 , the list relay section  543  of the client apparatus  500  receives the parental lock setting notification R17 including the set from the parental lock processing section  415  of the remote controller  400 . 
     In Step S 130 , the list relay section  543  transmits the parental lock setting request C8 including the set of the content ID, the parental lock, and the parental unlock code that are included in the parental lock setting notification R17 to the server apparatus  600   a  corresponding to the apparatus ID included in the parental lock setting notification R17 received. 
     As described above, by registering the parental unlock code in the content list table  720  stored in the content list storage section  632  of the server apparatus  600 , the server apparatus  600  can hold the parental unlock code for backup. Accordingly, it is possible not only to unify and manage the data relating to the parental lock setting or the like in the plurality of server apparatuses  600  by using the remote controller  400 , but also to prevent the parental unlock code from being lost because of losing the remote controller  400 . 
     The backup parental unlock code held in the server apparatus  600  is read from the content list table  720  by inputting a command and a password for referencing the parental unlock code to the server apparatus  600  or the client apparatus  500  by the user, for example. The parental unlock code read is displayed on the display section  506  of the client apparatus  500  or the display section  607  of the server apparatus  600 . By referencing the parental unlock code displayed, the user can reregister the parental unlock code to the remote controller  400 . 
     It should be noted that in this embodiment, the example in which one remote controller  400  is used is described, but the present invention is not limited to this. A plurality of remote controllers ( 400   a ,  400   b ) that respectively perform the two-way communication with a plurality of client apparatuses  500  connected to the home network  200  may be provided. In this case, the details of the update of the content management table  730  of the remote controller  400   a  may be transmitted to the remote controller  400   b  through the client apparatus  500  and reflected to the content management table  730  of the remote controller  400   b.    
     Thus, for example, when the parental lock setting operation is performed by using the remote controller  400   a  of the parent or guardian, the parental lock information can be promptly set to the remote controller  400   b  of the minor, which improves the convenience for the user. 
     In addition, one of the remote controllers ( 400   a  or  400   b ) holds a backup parental unlock code of the other remote controller ( 400   a  or  400   b ), which is useful as a prevention measure of losing the parental unlock code due to losing of one of the remote controllers ( 400   a  or  400   b ). 
     (Setting Release Operation with Respect to Content to which Parental Lock is Set) 
     Next, a setting release operation of the parental lock will be described with reference to  FIG. 21 .  FIG. 21  is a flowchart showing the setting release operation of the parental lock by the content management system  100 . 
     As shown in  FIG. 21 , the operations of Steps S 101  to S 124  are performed. Let us assume that in Step S 124 , the user selects the execution of the processing of the “parental lock” by using the input operation section  405  on the menu screen  801  displayed on the screen of the display section  404  of the remote controller  400 . The input operation section  405  supplies, to the UI processing section  412 , the selection information R12 of the processing of the “parental lock” selected by the user (Step S 201 ). 
     Upon reception of the selection information R12 of the “parental lock” processing from the input operation section  405 , the UI processing section  412  creates the display data of the parental unlock code input screen  802  (shown in  FIG. 16 ) based on the selection information R12 and supplies the display request R13 including the display data to the display section  404 . As a result, the parental unlock code input screen  802  is displayed on the screen of the display section  404 . 
     The user references the parental unlock code input screen  802  displayed on the display section  404  and inputs the parental unlock code by using the input operation section  405 . The input operation section  405  supplies the parental unlock code R14 input by the user to the UI processing section  412 . 
     Upon reception of the parental unlock code R14 from the input operation section  405 , the UI processing section  412  causes the input parental unlock code to be displayed for confirmation on the parental unlock code input screen  802  of the display section  404 . The user confirms whether the parental unlock code displayed is correct. When the parental unlock code is correct, the user presses a specific key of the input operation section  405  and inputs the fact that the parental unlock code to be input is decided (Step S 202 ). 
     The input operation section  405  notifies the UI processing section  412  of the decision. In response to this notification, the UI processing section  412  supplies, to the parental lock processing section  415 , a parental lock release request R15 including the input parental unlock code and the content ID corresponding to the content on which the release of the parental lock is decided to be performed by the user in Step S 123 . Upon reception of the parental lock release request R15, the parental lock processing section  415  reads the parental unlock code registered in the parental unlock code field  734  (see,  FIG. 17 ) in the corresponding record from the content management table  730  based on the content ID included in the parental lock release request R15. Then, the parental lock processing section  415  compares the parental unlock code included in the input parental lock release request R15 with the parental unlock code read from the parental unlock code field  734  of the content management table  730  (Step S 203 ). 
     When it is judged that both the parental unlock codes coincide (Yes in Step S 204 ), the parental lock processing section  415  updates the value of the parental lock flag set in the parental lock flag field  733  in the corresponding record from “with parental lock” to “without parental lock”. In addition, the parental lock processing section  415  deletes the parental unlock code corresponded to the parental lock flag (Step S 205 ). 
     When the setting of the parental lock is released as described above, the parental lock processing section  415  supplies, to the UI processing section  412 , a parental lock release completion notification R21 including the content ID of the content that has been subjected to the release of the parental lock. Upon reception of the parental lock release completion notification R21 from the parental lock processing section  415 , the UI processing section  412  supplies, to the display section  404 , a parental lock release display request R22 including the content ID that has been subjected to the release of the parental lock setting. Upon reception of the parental lock release display request R22 from the UI processing section  412 , the display section  404  deletes the graphic symbol  811  indicating that the parental lock is already set on the display list of the program title corresponding to the content that has been subjected to the release of the parental lock setting (Step S 206 ). 
     On the other hand, in Step S 204 , if it is judged that the parental unlock codes do not coincide (No in Step S 204 ), the parental lock processing section  415  supplies a code mismatch notification R23 to the UI processing section  412 . Upon reception of the code mismatch notification R23 from the parental lock processing section  415 , the UI processing section  412  performs an error processing so that the fact that an input error of the parental unlock code occurs is indicated for the user through the display section  404 . After that, the UI processing section  412  causes the menu screen  801  to be displayed again on the display section  404 , thereby urging the user to perform a subsequent operation (Step S 124 ). 
     The description will be return to the case where the parental lock setting is released. After the process of Step S 206 , the parental lock processing section  415  of the remote controller  400  performs the processing as follows. The parental lock processing section  415  transmits, to the client apparatus  500  by using the optical communication section  402 , a parental lock release notification R24 including the content ID of the content that has been subjected to the release of the parental lock and the apparatus ID of the server apparatus  600   a  in which the data of the content is accumulated (Step S 207 ). 
     The list relay section  543  of the client apparatus  500  receives the parental lock release notification R24 from the remote controller  400  by using the optical communication section  511  (Step S 208 ). The list relay section  543  transmits a parental lock release notification C10 including the content ID included in the parental lock release notification R24 to the server apparatus  600   a  corresponding to the apparatus ID included in the received parental lock release notification R24 via the home network  200  (Step S 209 ). 
     Upon reception of the parental lock release notification C10 from the client apparatus  500 , the parental lock processing section  633  of the server apparatus  600   a  performs the processing as follows. Based on the content ID included in the parental lock release notification C10, the parental lock processing section  633  updates the value of the parental lock flag set to the corresponding content in the content list table  720  from “with parental lock” to “without parental lock” (Step S 210 ). 
     Next, the parental lock processing section  633  transmits an update completion notification S3 including the apparatus ID and the content ID included in the parental lock release notification R24 to the client apparatus  500  via the home network  200  (Step S 211 ). 
     Upon reception of the update completion notification S3 (Step S 212 ), the list relay section  543  of the client apparatus  500  transmits an update completion notification C16 including the apparatus ID and the content ID included in the update completion notification S3 to the remote controller  400  by using the optical communication section  511  (Step S 213 ). 
     The parental lock processing section  415  of the remote controller  400  receives the update completion notification C16 from the client apparatus  500  (Step S 214 ). 
     Even in a case where the parental lock settings for the plurality of server apparatuses  600  are released, by performing the setting release operation of the parental lock as described above, the parental lock settings can be unified and managed by the remote controller  400 , with the result that the convenience for the user is improved. 
     (Reproduction Operation of Content to which Parental Lock is Set) 
     Next, a reproduction operation of the content to which the parental lock is set will be described with reference to  FIG. 26 .  FIG. 26  is a flowchart showing the reproduction operation of the content to which the parental lock is set by the content management system  100 . 
     As shown in  FIG. 26 , the operations of Steps S 101  to S 124  are performed. Let as assume that in Step S 124 , the execution of a “reproduction” processing is selected by the user by using the input operation section  405  on the menu screen  801  displayed on the screen of the display section  404  of the remote controller  400 . The input operation section  405  supplies the selection information R12 of the “reproduction” processing selected by the user to the UI processing section  412  (Step S 401 ). 
     Upon reception of the selection information R12 of the “reproduction” processing from the input operation section  405 , the UI processing section  412  creates display data of the parental unlock code input screen  802  (shown in  FIG. 16 ) based on the selection information R12 and supplies the display request R13 including the display data to the display section  404 . As a result, the parental unlock code input screen  802  is displayed on the screen of the display section  404 . 
     The user references the parental unlock code input screen  802  displayed on the display section  404  and inputs the parental unlock code by using the input operation section  405 . The input operation section  405  supplies the parental unlock code R14 input by the user to the UI processing section  412 . 
     Upon reception of the parental unlock code R14 from the input operation section  405 , the UI processing section  412  causes the input parental unlock code to be displayed for conformation on the parental unlock code input screen  802  of the display section  404 . The user confirms whether the parental unlock code displayed is correct. When the parental unlock code is correct, the user presses a specific key of the input operation section  405  and inputs the fact that the parental unlock code to be input is decided (Step S 402 ). 
     The input operation section  405  notifies the UI processing section  412  of the decision. In response to this notification, the UI processing section  412  supplies, to the parental lock processing section  415 , the parental lock release request R15 including the input parental unlock code and the content ID corresponding to the content that the user decides to reproduce in Step S 123 . Upon reception of the parental lock release request R15, the parental lock processing section  415  reads the parental unlock code registered in the parental unlock code field  734  (see,  FIG. 17 ) in the corresponding record from the content management table  730  based on the content ID included in the parental lock release request R15. Then, the parental lock processing section  415  compares the parental unlock code included in the input parental lock release request R15 with the parental unlock code that is read from the parental unlock code field  734  of the content management table  730  (Step S 403 ). 
     When it is judged that both the parental unlock codes coincide (Yes in Step S 404 ), the parental lock processing section  415  performs the following processing. That is, the parental lock processing section  415  transmits, to the client apparatus  500  by using the optical communication section  402 , a reproduction request R25 including the apparatus ID and the content ID corresponded to the content selected by the user (Step S 405 ). 
     The list relay section  543  of the client apparatus  500  receives the reproduction request R25 from the remote controller  400  by using the optical communication section  511  (Step S 406 ). The list relay section  543  transmits a content reproduction request C11 including the content ID included in the reproduction request R25 to the server apparatus  600   a  corresponding to the apparatus ID included in the received reproduction request R25 via the home network  200  (Step S 407 ). 
     The reproduction processing section  626  of the server apparatus  600   a  receives the content reproduction request C11 from the client apparatus  500  via the home network  200 . Upon reception of the content reproduction request C11, the reproduction processing section  626  performs a reproduction processing with respect to the content based on the content ID included in the content reproduction request C11 (Step S 408 ). 
     On the other hand, in Step S 404 , if it is judged that the parental unlock codes do not coincide (No in Step S 404 ), the parental lock processing section  415  supplies the code mismatch notification R23 to the UI processing section  412 . Upon reception of the code mismatch notification R23 from the parental lock processing section  415 , the UI processing section  412  performs an error processing so that the fact that the input error of the parental unlock code occurs is indicated for the user through the display section  404 . After that, the UI processing section  412  causes the menu screen  801  to be displayed again on the display section  404 , thereby urging the user to perform a subsequent operation (Step S 124 ). 
     (Move Operation of Content to which Parental Lock is Set) 
     Next, a move operation of the content to which the parental lock is set will be described with reference to  FIG. 22 .  FIG. 22  is a flowchart showing the move operation of the content to which the parental lock is set by the content management system  100 . 
     As shown in  FIG. 22 , the operations of Steps S 101  to S 124  are performed. In Step S 124 , the user selects the execution of a “move” processing by using the input operation section  405  on the menu screen  801  displayed on the screen of the display section  404  of the remote controller  400 . The input operation section  405  supplies, to the UI processing section  412 , the selection information R12 of the “move” processing selected by the user (Step S 301 ). 
     Upon reception of the selection information R12 of the “move” processing from the input operation section  405 , the UI processing section  412  creates the display data of the parental unlock code input screen  802  (shown in  FIG. 16 ) based on the selection information R12 and supplies the display request R13 including the display data to the display section  404 . As a result, the parental unlock code input screen  802  (shown in  FIG. 16 ) is displayed on the screen of the display section  404 . 
     The user references the parental unlock code input screen  802  displayed on the display section  404  and inputs the parental unlock code by using the input operation section  405 . The input operation section  405  supplies a parental unlock code R20 input by the user to the UI processing section  412 . 
     Upon reception of the parental unlock code R20 input from the input operation section  405 , the UI processing section  412  causes the input parental unlock code to be displayed for confirmation on the parental unlock code input screen  802  of the display section  404 . The user confirms whether the parental unlock code displayed is correct. When the parental unlock code is correct, the user presses a specific key of the input operation section  405  and inputs the fact that the parental unlock code to be input is decided (Step S 302 ). 
     The input operation section  405  notifies the UI processing section  412  of the decision. In response to this notification, the UI processing section  412  supplies, to the parental lock processing section  415 , a move authorization request R31 including the input parental unlock code and the content ID corresponding to the content that the user has decided to move in Step S 123 . Upon reception of the move authorization request R31, the parental lock processing section  415  reads the parental unlock code registered in the parental unlock code field  734  (shown in  FIG. 17 ) in the corresponding record from the content management table  730  based on the content ID included in the move authorization request R31. Then, the parental lock processing section  415  compares the parental unlock code included in the move authorization request R31 with the parental unlock code read from the parental unlock code field  734  of the content management table  730  (Step S 303 ). 
     In Step S 304 , if it is judged that the parental unlock codes do not coincide (No in Step S 304 ), the parental lock processing section  415  supplies the code mismatch notification R23 to the UI processing section  412 . Upon reception of the code mismatch notification R23 from the parental lock processing section  415 , the UI processing section  412  performs an error processing so that the fact that an input error of the parental unlock code occurs is indicated for the user through the display section  404 . After that, the UI processing section  412  causes the menu screen  801  to be displayed again on the display section  404 , thereby urging the user to perform a subsequent operation (Step S 124 ). 
     When it is judged that both the parental unlock codes coincide (Yes in Step S 304 ), the parental lock processing section  415  performs the operation as follows. The parental lock processing section  415  gives an instruction to the UI processing section  412  to perform a processing so that the user selects one from among the server apparatuses  600  as a move destination. 
     Upon reception of the instruction from the parental lock processing section  415 , the UI processing section  412  reads the server name  702  from the server list table  710 , creates display data of the server selection screen  800  (shown in  FIG. 11 ) including the list of the server names  702 , and supplies the display request R4 including the display data to the display section  404 . The user references the server selection screen  800  and selects the server apparatus  600  as the move destination of the content by using the input operation section  405 . Herein, let as assume that the server apparatus  600   b  is selected (Step S 305 ). 
     The input operation section  405  supplies, to the UI processing section  412 , the move destination notification R28 including the apparatus ID of the server apparatus  600   b  selected as the move destination by the user. Upon reception of the move destination notification R28, the UI processing section  412  supplies, to the move processing section  416 , the apparatus ID of the server apparatus  600   b  as the move destination, which is included in the move destination notification R28. Further, the UI processing section  412  supplies, to the move processing section  416 , the content ID included in the selection information R10 received in Step S 123  and the apparatus ID of the server apparatus  600   a  as a move source, which is included in the server selection request R5 received in Step S 112 . 
     Upon reception of those information items from the UI processing section  412 , the move processing section  416  transmits the move request R29 including those information items to the client apparatus  500  by using the optical communication section  402  (Step S 306 ). 
     The list relay section  543  of the client apparatus  500  receives the move request R29 from the remote controller  400  by using the optical communication section  511  (Step S 307 ). Based on the apparatus ID of the server apparatus as the move source included in the move request R29, the list relay section  543  transmits, to the corresponding server apparatus  600   a , the move request C12 including the apparatus ID of the server apparatus  600   b  as the move destination and the content ID included in the move request R29 (Step S 308 ). 
     The move processing section  634  of the server apparatus  600   a  as the move source receives the move request C12 from the client apparatus  500  via the home network  200 . The move processing section  634  reads data of the content corresponding to the content ID included in the move request C12 from the content data storage section  624 . Subsequently, the move processing section  634  transmits the read content data to the corresponding server apparatus  600   b  via the home network  200  based on the apparatus ID of the server apparatus as the move destination, which is included in the move request C12 (Step S 309 ). 
     Upon completion of the transmission of the content data, the move processing section  634  deletes the content data from the content data storage section  624  (Step S 310 ). The move processing section  634  supplies a record deletion request to the content list processing section  631  of the apparatus to which the move processing section  634  itself belongs. Upon reception of the record deletion request, the content list processing section  631  deletes the information (record) as to the content moved in Step S 310  from the content list table  720  stored in the content list storage section  632  (Step S 311 ). 
     On the other hand, the server apparatus  600   b  as the move destination performs the following processing. That is, the move processing section  634  of the server apparatus  600   b  receives, via the home network  200 , data of the content transmitted in Step S 310  from the server apparatus  600   a  as the move source (Step S 312 ). The move processing section  634  writes the data of the content received in the content data storage section  624  thereof (Step S 313 ). Further, the move processing section  634  registers as a new record, in the content list table  720  thereof, the content ID, the program title, and the value of the parental lock flag that are the information on the currently received content (Step S 314 ). 
     The description will be returned to the operation of the server apparatus  600   a  as the move source. Upon completion of the move as described above, the content list processing section  631  of the server apparatus  600   a  as the move source performs the following processing. The content list processing section  631  transmits, to the client apparatus  500  via the home network  200 , a move completion notification S4 including the information on the content that have been moved, the apparatus ID thereof as the move source, and the apparatus ID of the apparatus as the move destination (Step S 315 ). 
     Upon reception of the move completion notification S4 from the server apparatus  600   a  via the home network  200  (Step S 316 ), the list relay section  543  of the client apparatus  500  transmits a move completion notification C13 to the remote controller  400  by using the optical communication section  511  (Step S 317 ). The move completion notification C13 includes the information on the content, the apparatus ID thereof as the move source, and the apparatus ID of the apparatus as the move destination. 
     The parental lock processing section  415  of the remote controller  400  receives the move completion notification C13 from the client apparatus  500  (Step S 318 ). Upon reception of the move completion notification C13, the parental lock processing section  415  updates the content management table  730  stored in the content list storage section  414  based on the information included in the move completion notification C13 (Step S 319 ). That is, the parental lock processing section  415  deletes the information (record) as to the already moved content of the server apparatus  600   a  as the move source from the content management table  730  stored in the content list storage section  414 . In addition, the parental lock processing section  415  adds the information (record) as to the already moved content of the server apparatus  600   b  as the move destination to the content management table  730 .  FIG. 23  is a diagram showing an example of the update of the content management table  730  because of the move. In this example, described is a case where data of a content whose content ID is “Program 2” stored in a server apparatus whose apparatus ID is “Server 2” is moved to a server apparatus whose apparatus ID is “Server 1”. In the case of the move, when the parental unlock code is included in the record of the information on the content as the move source, the parental lock processing section  415  performs the following processing before the information on the content as the move source is deleted. That is, the parental lock processing section  415  moves the parental unlock code to the record of the information on the content as the move destination on the content management table  730 . 
     When the content management table  730  is updated, the parental lock processing section  415  supplies an update completion response R27 of the content management table  730  to the UI processing section  412 . Upon reception of the update completion response R27, the UI processing section  412  creates display data of a dialog screen  803  for causing the user to determine whether the parental lock is set with respect to the moved content as shown in  FIG. 25 , for example. Then, the UI processing section  412  supplies the display request R4 including the display data of the created dialog screen  803  to the display section  404 . 
     Based on the display request R4 supplied from the UI processing section  412 , the display section  404  displays the dialog screen  803  on the display screen thereof (Step S 320 ). The user references the dialog screen  803  displayed on the display section  404  and determines whether the parental lock is set or not by using the input operation section  405 . Herein, if the user performs the input operation so that the parental lock is set by using the input operation section  405  (Yes in Step S 321 ), the process of the flowchart is terminated with the parental lock being set with respect to the content moved to the server apparatus  600   b.    
     On the other hand, if the user performs the input operation so that the parental lock is not set by using the input operation section  405  (No in Step S 321 ), the UI processing section  412  supplies a parental lock release request R30 to the parental lock processing section  415 . Upon reception of the parental lock release request R30, the parental lock processing section  415  updates the content management table  730  stored in the content list storage section  414  (Step S 322 ). That is, as shown in  FIG. 24 , the parental lock processing section  415  updates the value of the parental lock flag corresponding to the already moved content of the server apparatus  600   b  as the move destination, which is added to the content management table  730  in Step S 319 , from “with parental lock” to “without parental lock”, for example. Further, the parental lock processing section  415  deletes the parental lock management code that is associated with the content and registered in the content management table  730 . 
     Upon completion of the update of the content management table  730 , the parental lock processing section  415  performs the following processing. That is, the parental lock processing section  415  transmits a parental lock release notification R32 including the content ID of the content and the apparatus ID of the server apparatus  600   b  as the move destination to the client apparatus  500  by using the optical communication section  402  (Step S 323 ). 
     The list relay section  543  of the client apparatus  500  receives the parental lock release notification R32 including the set of the content ID of the content that is desired to be subjected to the release of the parental lock and the apparatus ID of the server apparatus  600   b  from the remote controller  400  by using the optical communication section  511  (Step S 324 ). Upon reception of the parental lock release notification R32, the list relay section  543  transmits a parental lock release request C14 including the content ID included in the parental lock release notification R32 to the server apparatus  600   b  corresponding to the apparatus ID included in the parental lock release notification R32 (Step S 325 ). 
     The parental lock processing section  633  of the server apparatus  600   b  receives the parental lock release request C14 from the client apparatus  500  via the home network  200  (Step S 326 ). Upon reception of the parental lock release request C14, the parental lock processing section  633  of the server apparatus  600   b  updates the content list table  720  stored in the content list storage section  632  thereof based on the parental lock release request C14 (Step S 327 ). That is, based on the content ID included in the parental lock release request C14, the parental lock processing section  633  retrieves the corresponding record on the content list table  720  and updates the value of the parental lock flag in the record from “with parental lock” to “without parental lock”. 
     Upon completion of the update of the content list table  720 , the parental lock processing section  633  of the server apparatus  600   b  transmits a parental lock release completion notification S5 to the client apparatus  500  via the home network  200  (Step S 328 ). 
     The list relay section  543  of the client apparatus  500  receives the parental lock release completion notification S5 from the server apparatus  600   b  via the home network  200  (Step S 329 ). Upon reception of the parental lock release completion notification S5, the list relay section  543  transmits a parental lock release completion notification C15 to the remote controller  400  by using the optical communication section  511  (Step S 330 ). 
     The parental lock processing section  415  of the remote controller  400  receives the parental lock release completion notification C15 from the client apparatus  500  by using the optical communication section  402  (Step S 331 ). In this way, the parental lock is set with respect to the content that has been moved. 
     With the parental lock setting operation described above, even in a case where the minor wants to move the content with his/her own server apparatus  600 , the move operation without the use of the remote controller  400  is not allowed. As a result, the parent or guardian can remotely set the parental lock by using the remote controller  400 , which improves the convenience for the user. 
     The embodiment of the present invention is not limited to the above embodiment and can be variously modified without departing from the gist of the present invention.