Patent Publication Number: US-2012030022-A1

Title: Electronic book system and content server

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is entitled to the benefit of and incorporates by reference essential subject matter disclosed in International Patent Application No. PCT/JP2010/58736 filed on May 24, 2010. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a technology for providing an electronic book service, more particularly, the present invention relates to a technology effectively applied to an electronic book system and a content server which enable playing music relating to a browsing electronic book at the same time. 
     BACKGROUND ART 
     In recent years, release and use of publications by means of electronic books have been rapidly spreading. The factors of this include the widespread use of a mobile terminal such as a mobile phone capable of browsing the content of the electronic book in addition to the PC (Personal Computer) and others. Furthermore, the use of dedicated terminals for browsing the electronic book using the technology of electronic paper and others has also been spreading recently. Meanwhile, distribution services of music content to PCs and mobile terminals are widely provided, and mobile terminals are often used as music players. 
     Some of electronic book contents include text data and/or image data accompanied with sound data such as sound effects and BGM, so that a sense of presence is improved as a viewer suitably plays the sound data in accordance with a browsing state of the electronic book. Further, a technology of distributing and playing music relating to an electronic book online as needed instead of BGM previously set in the electronic book has been proposed. 
     For example, Japanese Patent Application Laid-Open Publication No. 2010-68044 describes an electronic book display system including: a track distributing device including a music data distribution unit which distributes music data relating to bibliographic information of an electronic book; and an information processing device including a music data receiving unit which receives music data, a related information receiving unit which obtains related information relating to the music data, a purchase reception unit which accepts purchasing of product related to the track data, and a purchase information transfer unit which transfers purchase information related to the accepted product to an external payment device, the electronic book display system enabling browsing of electronic books with a sense of presence by playing track data corresponding to electronic book data, and further enabling a display of the related information on a display device and transfer of the related information to a mobile terminal device, and creation of opportunities of purchasing products. 
     DISCLOSURE OF THE INVENTION 
     When a user is browsing an electronic book, the presence and conformity during browsing can be improved by making the user able to browse with listening to BGM suitable with the content of the electronic book. In this situation, when the user can listen to not only fixed BGM previously accompanied with the electronic book but also BGM suitable with the user&#39;s likings and the current trend in the music market, the conformity would be improved more. 
     By the electronic book display system as described in Patent Document 1, distribution of music suitable with the content of the electronic book online, and playing that in accordance with browsing of the electronic book on the terminal side are possible. However, the electronic book display system of Patent Document 1 searches for music related to the bibliographic information of the electronic book and distributes the same, and it does not flexibly select recommended music in consideration of the user&#39;s attribution and/or preference to distribute the same nor distribute what they call “targeted advertising.” 
     In addition, by the electronic book display system in Patent Document 1, to compensate for content playability of a mobile terminal, acquisition of electronic book data from the mobile terminal and reception of music from the music distributing device are performed by the information processing device such as PC, and playback and output of the electronic book and music are performed to a display device such as TV. Thus, it is impossible to recommend music including music already purchased by the user and downloaded to the mobile terminal (i.e., music matching the user&#39;s preference). 
     Also, in recent years, along with spread of international roaming services by mobile phone communications carriers and spread of smartphones on globally common platforms represented by iPhone™, BlackBerry™, and Android™ terminal, distribution of content is being expanded across borders. In such a situation, for example, when browsing an electronic book purchased in Japan in foreign countries or vice versa, music, which should not normally be distributed against restrictions of copyright protection by a music copyright group in each country or region regarding the music, may be distributed and cause a copyright infringement. Meanwhile, the technology described in Patent Document 1 assumes a fixed terminal such as PC, and thus it does not consider such a content distribution and globalization of browsing environment. 
     Accordingly, a preferred aim of the present invention is to provide an electronic book system and a content server which selects music and/or advertisement etc. suitable with content of an electronic book and/or user&#39;s attribution, preference and so forth and distributes or instruct the same to a mobile terminal; the electronic book system and the content server enabling simultaneously playing selected music etc. when the user is browsing the electronic book on the mobile terminal; and the electronic book system and the content server enabling control of availability of distribution of music etc. after determining whether the mobile terminal exists in a distributable area or not. The above and other preferred aims and novel characteristics of the present invention will be apparent from the description of the present specification and the accompanying drawings. 
     The typical ones of the inventions disclosed in the present application will be briefly described as follows. 
     An electronic book system according to a typical embodiment of the present invention includes: a content server which retains and manages content containing an electronic book and music for providing services relating to browsing of electronic books and distribution of music via a network; and one or more terminals including a viewer having a function of browsing electronic books as being connected to the content server via the network and a function of playing music, the electronic book system having the following features. 
     More specifically, in the electronic book system, the viewer has an electronic book playback portion which plays and displays an electronic book specified by a user, and a music playback portion which plays music specified by the user or music selected by the content server. 
     Also, the content server has a feature in including: an information storage unit which retains attribution information of electronic books; a music information storage unit which retains attribution information of music; an electronic book distribution portion which refers to the electronic book information storage unit and distributes a specified electronic book to the electronic book playback portion to play the electronic book; a music distribution portion which distributes specified music to the music playback portion to play the music; and a music selection portion which obtains first attribution information of the electronic book being currently browsed on the viewer by the user from the electronic book information storage unit, selects music having second attribution information matching the obtained first attribution information from the music information storage unit to designate the selected music to the music distribution portion to distribute the same. 
     Moreover, the present invention can be also used in a content server used in the electronic book system described above. 
     The effects obtained by typical aspects of the present invention will be briefly described below. 
     According to the typical embodiment of the present invention, by selecting music, advertising, etc. matching contents of the electronic book, the user&#39;s attribution, preference, etc., and distributing or instructing the music, advertising, etc., it is possible to play the selected music etc. at the same time when the user is browsing the electronic book on the mobile terminal. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram illustrating a summary of a configuration example of an electronic book system which is an embodiment of the present invention; 
         FIG. 2  is a diagram illustrating an example of a data configuration of a member DB in the embodiment of the present invention; 
         FIG. 3  is a diagram illustrating an example of a data configuration of a store DB in the embodiment of the present invention; 
         FIG. 4  is a diagram illustrating an example of a data configuration of a purchase history DB in the embodiment of the present invention; 
         FIG. 5  is a diagram illustrating an example of a data configuration of an electronic book information DB in the embodiment of the present invention; 
         FIG. 6  is a diagram illustrating an example of a data configuration of a music information DB in the embodiment of the present invention; 
         FIG. 7  is a diagram illustrating an example of a data configuration of an advertisement information DB in the embodiment of the present invention; 
         FIG. 8  is a diagram illustrating an example of a data configuration of a distributable area DB in the embodiment of the present invention; 
         FIG. 9  is a diagram illustrating an example of a flow of processings upon playing music etc. as BGM at the same time when browsing an electronic book in the embodiment of the present invention; 
         FIG. 10  is a diagram illustrating an example of a flow of processings upon performing various operations related to the music during browsing of the electronic book in the embodiment of the present invention; 
         FIGS. 11A-11D  are diagrams illustrating screen examples upon playing music at the same time when browsing an electronic book in the embodiment of the present invention; 
         FIGS. 12A-12B  are diagrams illustrating screen examples upon performing display of a playlist in the embodiment of the present invention; 
         FIGS. 13A-13B  are diagrams illustrating screen examples upon performing search of music in the embodiment of the present invention. 
     
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted. 
     An electronic book system, which is an embodiment of the present invention, is a system in which music, advertisement, etc. matching contents of an electronic book, a user&#39;s attribution, preference, etc. are selected and the music, advertisement, etc. are distributed or instructed to a mobile terminal after determining whether the mobile terminal exists in a distributable area or not in a content server which distributes electronic books and music, the electronic book system providing content distribution services capable of playing the music etc. selected by the content server as BGM at the same time when the user is browsing the electronic book by a viewer on the mobile terminal. 
     &lt;System Configuration&gt; 
       FIG. 1  is a diagram illustrating a summary of a configuration example of an electronic book system which is an embodiment of the present invention. An electronic book system  1  has a configuration in which various terminals  20  owned by users are connected to a content server  100  which distributes and manages contents containing electronic books and music via a network  10  such as the Internet etc. In addition, the content server  100  and the terminals  20  can be connected to another company&#39;s music distribution system  30  which provides a distribution service of music by another company via the network  10 . 
     Here, “electronic book” means publication of contents of books like novels and comics, and publications of news, articles, etc. as contents of digital information, and it denotes those which can be browsed by a display as being distributed to an information processing device by streaming and/or browsing etc. Files of the electronic books are retained in the content server  100  as electronic books  104 . In the present embodiment, users browse the electronic books by using a viewer which is software program for browsing electronic books on the terminals  20 . 
     Also, “music” means distributed music etc. as digital information, and denotes music which can be played as being distributed to an information processing device by streaming and/or downloading. Music includes music in a track unit or an album unit, and further includes sample data of music as advertisement. Files of the music are retained in the content server  100  as music  106 . In addition, music already obtained by downloading etc. from the content server  100  or the another company&#39;s music distribution system  30  by the users are retained in the terminals  20  as music  201 . 
     The terminal  20  which is an information processing device for a user to browse an electronic book (electronic book  104 ) or play content such as music (music  106  or music  201 ) can be various types, for example, a smartphone (terminal  20   a ), a playback-only terminal of electronic books (terminal  20   b ), a general mobile phone etc. (terminal  20   c ) as long as the terminal can execute a viewer  200  compatible to the content. The viewer  200  is software program for browsing and playing contents and has each portion of an electronic book playback portion  210  which enables browsing of the electronic book  104  by playing it by streaming or browsing etc., and a music playback portion  220  which plays music (music  201  or music  106 ) directly or by streaming etc. 
     The content server  100  is formed of a computer system, and the content server  100  is a server system which manages content of the electronic books  104  and music  106  and provides browsing and playback services of the content by the viewer  200 . The content server  100  has, for example, each portion mounted by software program of an authentication portion  110 , a purchase processing portion  120 , an electronic book distribution portion  130 , and a music distribution portion  140 . Also, the content server  100  has each data base or a table of a member DB  101 , a store DB  102 , a purchase history DB  103 , an electronic book information DB  105 , a music information DB  107 , an advertisement information DB  108 , and distributable area DB  109 . 
     The authentication portion  110  performs a user authentication for determining whether the user is a member of the electronic book service provided by the electronic book system  1  or not by referring to the member DB  101  when the user of the terminal  20  carries out browsing of the electronic book  104  or playback of the music  106 . Also, the authentication portion  110  may have a function of performing a user authentication to the another company&#39;s music distribution system  30  cooperating with the content server  100 . 
     The purchase processing portion  120  performs processing upon purchase of the electronic book  104  or the music  106  by the user of the terminal  20 . For example, the purchase processing portion  120  performs display of a Web site for purchasing content based on information of the store DB  102 , addition of license information to the member DB  101  and/or the terminal  20  based on purchasing of content, download of content, payment processing relating to the purchase, etc. Contents of the purchase processing are stored in the purchase history DB  103 . Upon displaying the Web site for purchasing content, a way of cooperation such as mutually directing to a purchasing Web site provided by the another company&#39;s music distribution system  30  may be carried out. 
     The electronic book distribution portion  130  has an interface which receives requests relating to browsing of the electronic book  104  from the terminal  20  through the viewer  200 , and the electronic book distribution portion  130  enables browsing (playback) of the electronic book  104  by the electronic book playback portion  210  on the viewer  200 . Note that, various attribution information pieces regarding the electronic book  104  used for specifying and playing the electronic book  104  are stored and managed by the electronic book information DB  105 . 
     The electronic book distribution portion  130  further has a music selection portion  131  and performs processing for selecting the music  106  (or music  201  inside the terminal  20 ) matching the content of the browsing (playing) electronic book  104  or attribution and/or preference etc. of the user. The content of the electronic book  104  can be obtained from the electronic book information DB  105 . Also, information regarding attribution of the user and/or preference to the content can be obtained from, for example, attribution information or history information retained in the member DB  101  and/or purchase history DB  103 . Moreover, the advertisement information DB  108  may be referred to for selecting and playing music advertisement or sample music contained in the music  106  and/or the distributable area DB  109  may be referred to for determining a distributable area under copyright. 
     The music distribution portion  140  has an interface which receives request relating to playback of the music  106  from the terminal  20  through the viewer  200 , and enables playback of the music  106  at the music playback portion  220  on the viewer  200  by a technology of distribution by, for example, general streaming etc. Note that, various attribution information pieces relating to the music  106  used for specifying and playing the music  106  are stored and managed in the music information DB  107 . 
     Note that, while the music distributing portion  140 , the music  106 , and the music information DB  107  relating to music distribution are mounted on the content server  100  same as the electronic book distribution portion  130 , the electronic book  104  and the electronic book information DB  105  in the present embodiment, portions relating to music distribution may be mounted on another content server when another music distribution service is already provided and so forth. 
     &lt;Data Configuration&gt; 
       FIG. 2  is a diagram illustrating an example of a data configuration of the member DB  101 . The member DB  101  is a table for managing account information of users who are members of the electronic book service provided by the electronic book system  1 , and, for example, the member DB  101  contains each item of member ID, authentication information, age, gender, registration date, tags  1  to  3 , etc. 
     The item of member ID retains ID information for uniquely identifying each user who is a member. That is, information of a user ID for the user to log in by accessing the content server  100  from the terminal  20  is retained. The item of authentication information retains information (for example, password etc.) for carrying out a user authentication for the target member (user) to log in to the content server  100 . The items of age and gender retain information of age and gender as attribution information of the target user, respectively. Other information such as address or occupation may be retained in addition to these pieces of attribution information. 
     The item of registration date retains information of time and date of information of a target user registered to the member DB  101 . The items of tags  1  to  3  retain information to be keywords for a search upon performing a criteria search for the music selection portion  131  of the electronic book distribution portion  130  to select the music  106 . For example, a genre the target user is interested in and/or attribution information relating to preference such as favorite artists can be set as keywords as being specified by the user. 
       FIG. 3  is a diagram illustrating an example of a data configuration of the store DB  102 . The store DB  102  is a table for managing information relating to the Web site for purchasing the music  106 , and has each item of, for example, content ID, store URL, registration date, etc. The item of content ID retains ID information for uniquely identifying each content of the electronic book  104  and music  106 . 
     The item of store URL retains information of a URL (Uniform Resource Locator) of the Web site (store) for purchasing target content. The item is not limited to a Web site for purchasing provided by the content server  100 , and it may be a Web site provided by the another company&#39;s music distribution system  30 . The another company&#39;s music distribution system  30  provides (places an ad), for example, the music  106  as a music sample for advertisement so that users who are interested in that are directed to own Web site for purchasing. The item of registration date retains information of time and date of registration of the target information to the store DB  102 . 
       FIG. 4  is a diagram illustrating an example of a data configuration of the purchase history DB  103 . The purchase history DB  103  is a table of managing information relating to a history of purchasing contents such as the electronic book  104  and/or music  106  by the user, that is, information relating to contents already purchased by the user, and the purchase history DB  103  has each item of, for example, member ID, purchase date, purchased content ID, number of purchased items, tags  1  to  3 , etc. 
     The item of member ID retains information of member ID for specifying a user who purchased target content. The item of purchase date retains information about time and date when the user purchased the target content. The item of purchased content ID retains information of ID which specifies content such as the electronic book  104  or music  106  which the user has purchased. The item of number of purchase retains information of a number of contents the user has purchased. The items of tags  1  to  3  retain attribution information to be keywords for search upon performing a criteria search for the music selection portion  131  to select the music  106 . For example, information of genre and/or category of the target content can be set as a keyword. 
     According to the purchase history DB  103  described above, tendency (preference) of purchase of the user can be grasped. From this point of view, other than the purchase history DB  103 , a processing history DB, which retains information related to histories of various processings such as browsing and playback of contents of the electronic book  104  and music  106  carried out by accessing to the content server  100  by the target user in chronological order, may be provided. 
       FIG. 5  is a diagram illustrating an example of a data configuration of the electronic book information DB  105 . The electronic book information DB  105  is a table for managing various attribution information pieces related to the electronic book  104 , and has, for example, each item of content ID, content name, author name, publication date, publisher, introduction, billing information, advertisement flag, registration date, tags  1  to  3 , etc. 
     The item of content ID retains ID information for uniquely authenticating the electronic book  104 . For example, a file name (“A0001.tar” or the like) of the electronic book  104  can be used as a content ID. The item of content name retains information of a title of the electronic book  104 . The items of author name, publication date, and publisher retain information of an author, a publication date, and a publisher of the target electronic book  104 , respectively. The item of introduction retains information of an introduction added by the publisher or an operator of a distribution site about the target electronic book  104 . The item of billing information retains information of a billing method or price for browsing the target electronic book  104 . 
     The item of advertisement flag retains information of a flag indicating whether playback of music as an advertisement is allowed or not during browsing of the target electronic book  104 . The item of registration date retains information of time and date of registration of the information of the target electronic book  104  to the electronic book information DB  105 . The items of the tags  1  to  3  retain information to be a keyword for search upon performing a criteria search for the music selection portion  131  to select the music  106 . For example, attribution information such as a genre and/or a category of the target electronic book  104  can be set as a keyword. 
       FIG. 6  is a diagram illustrating an example of a data configuration of the music information DB  107 . The music information DB  107  is a table for managing various attribution information related to the music  106 , and has, for example, each content of content ID, content name, artist name, album name, release date, label, introduction, rating, billing information, area ID, registration date, tags  1  to  3 , etc. 
     The item of content ID retains, in the same manner as the content ID of the electronic book information DB  105 , ID information for uniquely identifying the music  106 . It is preferable that the ID information is also unique to the electronic book  104 . The item of content name retains information of a title of the music  106 . The items of artist name, album name, release date, and label retain information of a performance artist of the target music  106 , a title of a recording album, a release date, and a producer/distributor label, respectively. The item of introduction retains information of an introduction added by a record company or an operator of a distribution site etc. about the target music  106 . The item of rating retains information of a rating of each user about the target music  106 . For example, the rating can be calculated by an average value of values rated by points or stages with respect to the target music  106  by each user. 
     The item of billing information retains information of a billing method and/or price for playback of the target music  106 . The item of area ID retains, when a distributable area of the target music  106  is limited with regards to copyright etc., ID information for identifying the area (for example, “Japan”). The item of registration date retains information of time and date of registration of the target music  106  to the music information DB  107 . The items of tags  1  to  3  retain information to be a keyword for search upon performing a criteria search for the music selection portion  131  to select the music  106 . For example, attribution information such as a genre and/or category of the target music  106  can be set as a keyword. 
       FIG. 7  is a diagram illustrating an example of a data configuration of the advertisement information DB  108 . The advertisement information DB  108  is a table for managing information regarding target ads about music (music  106  and/or music distributed by the another company&#39;s distribution system  30 ), and has each item of, for example, advertising ID, advertizing site URL, target generation, target gender, book content ID, music content ID, tags  1  to  3 , etc. 
     The item of advertisement ID retains information of an ID for uniquely identifying each advertisement information piece. The item of advertising site URL retains information of a URL of a Web site presenting advertisement information to the user. This is not limited to an advertising Web site provided by the content server  100  but maybe an advertising Web site provided (placed) by the another company&#39;s music distribution system  30 . The items of target generation and target gender retain information of a generation and a gender of the target user for whom a target advertisement is presented, respectively. 
     The book content ID retains information of a content ID for specifying the electronic book  104  for which a target advertisement is presented. A plurality of the electronic books  104  can be specified, and the electronic book  104  can be specified by a matching of the tags  1  to  3  described later and the tags  1  to  3  of the electronic book information DB  105  instead of specifying the electronic book  104  by the content ID. The item of the music content ID retains information of a content ID for specifying music (for example, sample music data, advertising short omnibus etc.) corresponding to the target advertisement. A plurality of music pieces may be specified. The items of tags  1  to  3  retain information to be a keyword for selecting an advertisement to be presented to the browsing electronic book  104 . For example, attribution information of a genre and/or a category of the music to be a target of an advertisement can be set as a keyword. 
       FIG. 8  is a diagram illustrating an example of a data configuration of a distributable area DB  109 . The distributable area DB  109  is a table for managing information about each area when a distributable area (region) is limited in accordance with copyright etc., and has each item of, for example, area ID, area name, start IP address, end IP address, etc. 
     The item of area ID retains ID information for uniquely identifying each distributable area. The item of area name retains information about a name (country name, region name, etc.) of a target area. The items of start IP address and end IP address retain information relating to ranges of IP address of the terminal  20  predicted to exist in the target area. 
     In each table described above in the present embodiment, while there are tables specifying three tags of the tags  1  to  3 , the number of specified tags is not limited to this, and it can be an arbitrary number. Also, the numbers of items and types of each of the tables described above are just examples, and it is needless to say that information managed by each of the tables described above may be retained by other data configurations. 
     &lt;Processing Contents&gt; 
     In the following, contents of processings in the electronic book system  1  of the present embodiment will be described.  FIG. 9  is a diagram illustrating an example of a flow of processings upon playing the music  106  etc. at the same time of browsing the electronic book  104 . 
     First, when the viewer  200  is launched on the terminal  20  by the user, the viewer displays a login screen (S 101 ). When the user sends a login request by inputting his/her member ID and authentication information (S 102 ), the viewer  200  transfers a login request to the content server  100  (S 103 ). In the content server  100 , the member DB  101  is referred by the authentication portion  110  to perform an authentication (user authentication) whether the user is a member of the electronic book service provided by the content server  100  or not (S 104 ). 
     When the user authentication is valid, in the present embodiment, the viewer  200  asks the user whether he/she wishes to play the music  106  or the music  201  on the terminal  20  as BGM during browsing of the electronic book  104  or not (S 105 ). When the user selects to play or not to play the music (S 106 ), the viewer  200  requests a list of the electronic books  104  which the user can browse to the content server  100  (S 107 ). 
     In the content server  100 , information of the electronic book  104 , which has been already purchased by the target user, is obtained from the purchase history DB  103  by the electronic book distribution portion  130 , and a list of the electronic books  104  available to browse is created referring to the electronic book information DB  105 , and the list is transferred to the viewer  200  (S 108 ). In the situation, for example, the advertisement information DB  108  may be referred, and information may be added to the list as a target ad of the book, the information of a book content ID corresponding to an advertisement about a target generation, a target gender, and a genre (tags  1  to  3 ) matching the target user&#39;s age, gender, and/or interested genre (for example, the tags  1  to  3  in the member DB  101 ). 
     By displaying the list (and advertising) of the electronic books  104  on the viewer  200  based on transferred contents (S 109 ), the user can refer to the list (or advertisement) of the electronic books  104  he/she can browse (S 110 ). Note that, for example, when the user selects to play the music in the step S 106 , the viewer  200  may previously activate a function of the music playback portion  220  as a music player function upon displaying the list in the step S 109 . 
     Thereafter, when the user selects a desired electronic book  104  and requests browsing of the electronic book  104  (S 111 ), the viewer  200  transfers a browsing request of the target electronic book  104  to the content server  100  (S 112 ). In the content server  100 , contents of the electronic book  104  which is the browsing target is obtained referring to the electronic book information DB  105  by the electronic book distribution portion  130 , and the contents are transferred to the viewer  200  (S 113 ). By displaying the contents of the electronic book  104  which is the browsing target by the electronic book playback portion  210  on the viewer  200  based on the transferred contents (S 114 ), the user can browse the electronic book  104  which is the browsing target (S 117 ). 
     Also, in the content server  100 , for example, as a parallel processing to the step S 113 , the music  106  (or the music  106  as an advertisement), which matches the contents of the electronic book  104  which is the browsing target, an attribution and preference of the user, is selected by the music selection portion  131 , and the music  106  is distributed to the viewer  200  by streaming etc. by the music distribution portion  140  (S 115 ). By playing the music  106  on the viewer  200  by the music playback portion  220  based on the distributed contents (S 116 ), during browsing of the electronic book  104 , the music  106 , which the content server  100  recommends as music which matches the electronic book  104 , can be played as BGM. 
     In the step S 115 , the music selection portion  131  of the content server  100  refers to the electronic book information DB  105  to confirm a value of an advertisement flag of the target electronic book  104 . When the advertisement flag is OFF, attribution information (tags  1  to  3 ) about the target electronic book  104  is obtained from the electronic book information DB  105  and the music information DB  107  is referred so that information about the music  106  matching attribution information (tags  1  to  3 ) is obtained referring to the music information DB  107 . In this situation, when information of a store URL corresponding to the target music  106  is registered to the store DB  102 , the information is also obtained together as associated information of the music  106 . 
     When the advertisement flag of the electronic book  104  which is the browsing target is ON, for example, a content ID and/or attribution information (tags  1  to  3 ) about the target electronic book  104  are/is obtained from the electronic book DB  105 , and further, attribution information (information of genres and/or artists purchased at the highest frequency in the past for the target user or other users of the same gender and same generation) is obtained from the member DB  101  and/or purchase history DB  103 . By performing matching of these information pieces and book content IDs of the advertisement information DB  108  and/or attribution information (target generation, target gender, and/or tags  1  to  3 ), for example, when there is advertisement information hit regarding one or more items, information about the music  106  (for example, sample music data and/or a short omnibus for advertisement etc.) determined by the specified music content ID is obtained. In this situation, information of an advertising site URL is also obtained together as associated information of the music  106 . 
     After obtaining the information of the music  106 , information of an IP address of the terminal  20  of an access source is further obtained from a request message and/or information of network session etc. and together with the information of the distributable area DB  109 , and whether the obtained music  106  is distributable or not is determined. Not distributable ones of music  106  are eliminated. When a plurality of music pieces  106  are obtained from a result of the processings described above, these pieces may be played in sequence, or, for example, a predetermined number of music pieces  106  may be selected randomly and played or a predetermined number of music pieces  106  selected in descending order of matched attribution information pieces may be selected and played. 
       FIGS. 11A to 11D  are diagrams illustrating screen examples upon performing playback of the music  106  at the same time of browsing the electronic book  104  by the viewer  200 .  FIG. 11A  is a diagram illustrating a screen example upon asking the user whether he/she wishes to play music as BGM during browsing of the electronic book  104  or not in the step S 105  in  FIG. 9  when activating the viewer  200  of the terminal  20 . Here, when the user selects Yes or No (“Yes” in the example of  FIGS. 11A and 11B ) of playback of the music  106  in the step S 106 , and then the sequence of processings of the steps S 107  to S 117  are performed, the screen as illustrated in  FIG. 11B  is displayed, and playback of the music  106  recommended by the content server  100  is performed at the same time of browsing the electronic book  104 . 
     Here, in the present embodiment, an example of displaying the electronic book  104  on a mobile terminal having a touch panel such as a smartphone is described. On the screen illustrated in  FIG. 11B , for example, at an upper portion of the screen on which content of the electronic book  104  is displayed, a menu area  201  in which various menus and buttons etc. for performing operation to the viewer  200  by the user is included. Also, at a lower portion of the screen, in an aspect not to be a barrier of browsing the electronic book  104 , a music information display area  202  in which simple information of a title, artist name, etc. about the music  106  being played is displayed is included. 
     In this state, the user can carry out processings such as various operations regarding playback of the music  106  and purchasing of the music etc. at the same time of browsing the electronic book  104 .  FIG. 10  is a diagram illustrating an example of a flow of processings upon carrying out various operations relating to the music  106  (or the music  201 ) during browsing of the electronic book  104 . 
     The user can switch music player functions (music playback portion  220 ) for controlling playback of the music (or the music  201 ) by calling and closing the functions as needed during browsing of the electronic book  104  on the viewer  200  (S 201 ). Every time the viewer  200  receives instructions from the user, the viewer  200  alternately switches display/no-display of the music player function (S 202 ). 
     In the screen of  FIG. 11B  described above, for example, when the user taps an arrow button at a right portion of the music information display area  202 , as illustrated in  FIG. 11C , a music player area  203  for controlling playback of the music  106  is displayed at a lower portion of the screen. Here, when the arrow button at the right portion of the music information display area  202  is tapped again, the music player area  203  is closed, and the screen is back to the screen of  FIG. 11B . In this manner, the user can alternately switch display/no-display of the music player area  203  as needed. 
     In the music player area  203 , in addition to operations such as play, stop, etc. of the music by the music playback portion  220 , for example, when the user wishes to purchase the music  106  being played, by tapping a cart button at a right portion of the music player area  203 , a Web site (not illustrated) for purchasing the music  106  being played can be displayed as described later. When the music  106  being played is an advertisement, a Web site (not illustrated) for advertising may be displayed. 
     Also, in the screen of  FIG. 11C , for example, to know detailed information of the music  106  being played, by tapping a musical note button at a left portion of the music player area  203 , a music detail information screen as illustrated in  FIG. 11D  is displayed. Here, generally contained functions as a music player such as instructions of volume control, repeat playback, and random playback etc.; and display of an album jacket image, rating, playback status, etc. are provided by the music playback portion  220 . 
     To get back to  FIG. 10 , during browsing of the electronic book  104  on the viewer  200 , the user can request display of a playlist about the music to be played (S 211 ). The viewer  200  transfers an acquisition request of the playlist to the content server  100  upon receiving the request from the user (S 212 ). In the music selection portion  131  of the content server  100 , in the same process as obtaining information of the music  106  played in the step S 115  in  FIG. 9 , information of the music  106  to play, that is, a playlist is created (updated) and transferred to the viewer  200  (S 213 ). On the viewer  200 , by displaying contents of the playlist based on the transferred contents (S 214 ), the user can refer to the playlist (S 215 ). 
     Here, when the viewer  200  requests a playlist in the step S 212 , the user may transfer information of the music  201  (title, artist name, etc.) already retained by the terminal  20  by download etc. together. In this manner, in the music selection portion  131  of the content server  100 , the user can select recommended music including the music  201  retained in the terminal  20  by the user. In this situation, the music  201  retained by the terminal  20  may be included in the playlist by necessity, and also the music  201  may be integrally handled with the music  106  by raising/lowering priority to the music  106  on the content server in a matching with the attribution information of the electronic book  104 . 
       FIGS. 12A and 12B  are diagrams illustrating screen examples upon performing a display of a playlist by the viewer  200 .  FIG. 12A  illustrates a state in which music is played during browsing of the electronic book  104  and the music player area  203  is displayed in the same manner as  FIG. 11C . Here, when the user taps a playlist button in the music player area  203 , acquisition of the playlist is carried out by the music selection portion  131  in the content server  100 , and, as illustrated in  FIG. 12B , a playlist is displayed with a list of the music  201  already retained by the terminal  20 . 
     Here, the playlist created by the music selection portion  131  of the content server  100  is displayed as “Recommendation For This Book” in the example of  FIG. 12B , and when the user selects this, music (the music  106  or music  201 ) matching the electronic book  104  which the user is browsing can be played. Note that the user can use the terminal  20  as a general music player by selecting the music  201  already retained in the terminal  20 . 
     To get back to  FIG. 10 , as described above, the user selects to play the desired music  201  or recommended music (the music  106  or music  201  specified in the playlist transferred from the content server  100 ) matching the browsing electronic book  104  from the playlist as illustrated in  FIG. 12B  (S 216 ). The viewer  200  plays the music by the music playback portion  220  when the selected music is the music  201  retained in the terminal  20  (S 217 , S 219 ). 
     Meanwhile, when the selected one is recommended music, music specified in the playlist transferred from the content server  100  is sequentially played. In this situation, when the music is the music  201  retained in the terminal  20 , the music is directly played by the music playback portion  220  in the same manner as described above (S 217 , S 219 ). On the other hand, when the music is the music  106  retained in the content server  100 , a play request of the music  106  is sent to the content server  100  (S 217 ). In the content server  100 , the music information DB  107  is referred by the music distribution portion  140 , and the music  106  is distributed (S 218 ), and, in the viewer  200 , the music  106  is played by the music playback portion  220  based on the distributed contents (S 219 ). 
     In this manner, the music  201  already retained in the terminal  20  and the music  106  retained in the content server  100  are integrally handled and music matching the electronic book  104  can be played. Note that, upon creating the playlist in the content server  100  in the step S 213 , the music  201  retained in the terminal is used as an object in the playlist only when the music  201  is identical to the music  106  retained in the content server  100 , and the playback may be standardized such that all playback is performed by distribution of the music  106  on the content sever  100 . 
     When the user wishes to purchase the music  106  being played by distribution from the content server  100  during browsing of the electronic book  104 , the user can send a request of purchasing the music  106  on the viewer  200  (S 221 ). For example, in the screen of  FIG. 11C , a cart button at a right portion of the music player area  203  is tapped. The viewer  200  transfers the purchase request together with information of the playing music  106  to the content server  100  (S 222 ). 
     In the content server  100 , by the purchase processing portion  120 , whether the target music  106  has been already purchased or not is confirmed by referring to the purchase history DB  103 , and a store link process of displaying a purchasing Web site of the target music  106  or an advertising Web site is performed when the music  106  has not been purchased yet (S 223 ). Information of URLs of these Web sites can be obtained by referring to information which has been obtained as additional information upon obtaining information of the music  106  by the music selection portion  131  of the content server  100  in the step S 115  in  FIG. 9 . 
     When the target music  106  is music distributed by the another company&#39;s distribution system  30 , a Web site provided by the another company&#39;s distribution system  30  is displayed to guide. On the viewer  200 , by displaying the purchasing Web site (or the advertizing Web site) instructed from the content server  100  (S 224 ), the user can purchase the target music  106  as browsing the Web site (S 225 ). 
     Also, the user can send a request for searching for the music  106  for playing it as BGM or purchasing it during browsing of the electronic book  104  (S 231 ). The viewer  200  transfers a search request to the content server  100  (S 232 ). At the content server  100 , a search screen is displayed by, for example, the music distribution portion  140  (S 233 ). In this situation, the search screen may be displayed after carrying out various settings for a later search. On the viewer  200 , the search screen is displayed based on instructions from the content server  100  (S 234 ). 
       FIG. 13  is a diagram illustrating a screen example upon performing a search of the music  106  on the viewer  200 . For example, in the music detail information screen (in the same manner as  FIG. 11D ) as illustrated in  FIG. 13A , as a search button in the menu area  204  at a lower portion of the screen is tapped by the user, a search screen as illustrated in  FIG. 13B  is displayed by the content server  100 . 
     To get back to  FIG. 10 , the user inputs keywords such as a title of the music  106 , an album name, an artist name etc. as search criteria, and a search request of the music  106  can be sent by tapping the search button at the lower portion of the screen (S 235 ). The viewer  200  transfers the search request containing the specified keywords to the content server  100  (S 236 ). In the content server  100 , for example, the music information DB  107  etc. is referred by the music distribution portion  140 , and a list of music hitting the search criteria is created from the music  106  distributed by the content server  100  or the another company&#39;s music distribution system  30  and the list is transferred to the viewer  200  (S 237 ). 
     In the viewer  200 , by displaying a search result of the music  106  based on the transferred contents (S 238 ), the user can refer to the result (S 239 ). The music  106  contained in the search result may be played or purchased as the user selects it. 
     As described in the foregoing, according to the electronic book system  1  which is an embodiment of the present invention, in the content server  100  which distributes the electronic book  104  and the music  106 , the music  106  distributed by the content server  100  and/or the another company&#39;s music distribution system  30  and the music  201  retained in the terminal  20  are handled as a unit, and thus music and/or advertisement matching contents of the electronic book  104  , an attribution and/or preference of the user can be selected and distributed or instructed. Also, after determining whether the terminal  20  is in a distributable area or not, availability of distribution of the music  106  can be controlled. 
     In this manner, it is possible to provide a content distribution service capable of playing the music  106  etc. selected by the content server  100  as BGM at the same time when the user browses the electronic book  104  by the viewer  200  on the terminal  20 , and it is possible to promote purchasing of music as well as to improve a sense of presence and the comfort level during browsing of the electronic book  104 . Also, with addressing globalization of content distribution and browsing environment, it is possible to carry out a distribution of music while avoiding a copyright infringement. 
     In the foregoing, the invention made by the inventor of the present invention has been concretely described based on the embodiments. However, it is needless to say that the present invention is not limited to the foregoing embodiments and various modifications and alterations can be made within the scope of the present invention. 
     The present invention can be used in an electronic book system and a content server which enable playback of music etc. related to a browsing electronic book at the same time. 
     While the present invention has been illustrated and described with respect to a particular embodiment thereof, it should be appreciated by those of ordinary skill in the art that various modifications to this invention may be made without departing from the spirit and scope of the present.