Patent Publication Number: US-2010110843-A1

Title: Reproducing apparatus and program

Description:
TECHNICAL FIELD 
     The present invention relates to a reproducing apparatus having two operation mechanisms for performing reproduction control for two contents and a program therefor. 
     BACKGROUND ART 
     There has been known a reproducing apparatus having two operation mechanisms as equipment dealt by DJs who give music performance in a club or the like (for example, Non-Patent Document 1). 
     Further, there has been known a reproducing apparatus which is connected to two mobile music players and which is capable of reproduction control of contents read from respective music players with two operation mechanisms (for example, Non-Patent document 2). The reproducing apparatus uses displays mounted on the music players as display unit displaying content names so as to make the apparatus smaller. 
     [Non-Patent Document 1] Numark, DVD01, http://www.numark.com/index.html? http://www.numark.com/products/product_view.php?v=over view&amp;n=154
 
[Non-Patent Document 2] Numark, iDJ, http://www.numark.jp/index.html? http://www.numark.jp/products/product_view_overview 132.html
 
     DISCLOSURE OF THE INVENTION 
     Problems to be Solved 
     However, this kind of twin-type reproducing apparatus has specification such that two reproducing apparatuses are merely combined, in which a display unit for selecting a content to be a reproduced object (an operated object for reproduction control) is provided independently, leading to a poor usability. 
     An object of the invention is, in view of the above problem, to provide a twin-type reproducing apparatus with high usability and a program therefor. 
     Means to Solve the Problems 
     A reproducing apparatus of the invention has: a reading unit that reads an information recording medium recorded with a plurality of contents therein; a reproduction unit that can reproduce two of the contents simultaneously; an operation unit that is capable of reproduction control of the two contents reproduced by the reproduction unit; a content list generation unit that generates a content list of a plurality of the contents; a content list display unit that displays the generated content list on a display screen; a content selection unit that selects contents to be operated objects by the two operation mechanisms from the displayed content list; a content sort unit that sorts the contents read by the reading unit to the two operation mechanisms based on a selection result of the content selection unit; and a sort result display unit that displays the sort result by the content sort unit on the display screen. 
     With this structure, as the content list for selecting the two contents reproduced by the reproduction unit is displayed on the display screen, a user can perform a selection operation and a sort operation by seeing only the display screen, thereby operation error is avoided and operability will be enhanced. Also, the sort result of the contents to the two operation mechanisms is displayed on the same display screen, the user can acknowledge which operation mechanism can be operated, leading to high usability. Further, as the two operation mechanisms for reproduction control to the reproduced contents are provided per content, independent reproduction control can be performed. Therefore, various music and video expressions can be achieved. 
     In the reproducing apparatus described above, it is preferable that the reading unit include a plurality of reading mechanisms, the content list generation unit generate the content list per a plurality of information recording media read by a plurality of the reading mechanisms, the content selection unit designate the information recording medium, display the content list for the information recording medium on the content list display unit, and select contents to be operated objects for the two operation mechanisms from the displayed content list. 
     With this structure, as a plurality of reading mechanisms are provided, it is possible to select contents to be operated objects from a number of contents. Further, as the content list is generated per information recording medium, it is easy to retrieve the content in a case that each information recording medium is separated by category or by use. 
     In the reproducing apparatus described above, it is preferable that it further have an operation mechanism index unit that indexes the operation mechanism sortable by the content sort unit based on a data type of the content read by each reading mechanism. 
     With this structure, there are instances that two contents from a same information recording medium can not be reproduced simultaneously depending on data type of the contents. Even in such a case, as a sortable operation mechanism is indexed, it is possible to sort according to the index. Therefore, the user does not need to worry about the data type of the contents. 
     In the reproducing apparatus described above, it is preferable that a plurality of the reading mechanisms have one or more reading mechanisms that read the information recording medium recorded with the content which can be controlled in reproduction by either one of the two operation mechanisms. 
     With this structure, as the contents read by one or more reading mechanisms can be controlled in reproduction by both operation mechanisms, the user can use without worrying whether sort can be performed or not. 
     In the reproducing apparatus described above, it is preferable that the sort result display unit show the sorted operation mechanism in the content list displayed by the content list display unit. 
     With this structure, it is possible to acknowledge a sort destination and a sorted content at the same time because the sorted operation mechanism is displayed in the content list. Further, the display screen can be used for displaying the content list effectively because a display area for displaying the sort result is not needed. 
     In the reproducing apparatus described above, it is preferable that the sort result display unit show the operation mechanism sorted by additional information to each content title or a display mode of each content title. 
     With this structure, it is possible to display the sort destination of each content comprehensively. 
     In the reproducing apparatus described above, it is preferable that it further have a display type selection unit that selects either one of a folder display type displaying the content list according to a hierarchy structure of the contents stored in the information recording medium and a category display type displaying the content list by category based on the additional information added to each content, and that the content list display unit selectively display the content list generated by the content list generation unit according to a selection result by the display type selection unit. 
     With this structure, it is possible to select either one of the folder display type and the category display type according to user&#39;s preference. In a case that contents are stored in the information recording medium in consideration of use application in advance, if the folder display type is selected, the type is convenient for the user. In a case that contents are stored in the information recording medium at random, if the category display type is selected, the contents are sorted by category, thereby the type is convenient for the user. 
     Content lists may be preliminary generated before content lists of both of the display types are selected by the display type selection unit, or either one of the content lists may be generated based on a selection result after selecting display type. 
     In the reproducing apparatus described above, it is preferable that the operation unit include a jog dial that adjusts a reproduction state according to rotation amount of a rotating body thereof as operation mechanism. 
     With this structure, as the jog dial is provided, various effects can be achieved. 
     In the reproducing apparatus described above, it is preferable that the content list display unit be disposed between the two operation mechanisms. 
     With this structure, as the content list is displayed at a center, the list can easily be seen and the two operation mechanisms are easy to operate. 
     A program of the invention allows a computer to function as each unit in the reproducing apparatus described above. 
     By implementing the program, it is possible to provide a twin-type reproducing apparatus having high usability. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a plan view of a reproducing apparatus according to one embodiment of the invention and  FIG. 1B  is an elevation view thereof. 
         FIG. 2  is a block diagram of the reproducing apparatus. 
         FIG. 3  is an exemplary diagram of a display at the time of file browse. 
         FIG. 4  is an exemplary diagram of the display at the time of ID3 browse. 
         FIG. 5  is a screen transition diagram from  FIG. 4 . 
         FIG. 6  is a screen transition diagram from  FIG. 5 . 
         FIG. 7  is a screen transition diagram from  FIG. 6 . 
         FIG. 8  is a screen transition diagram from  FIG. 7 . 
         FIG. 9  is a screen transition diagram from  FIG. 8 . 
         FIG. 10  is a screen transition diagram from  FIG. 9 . 
     
    
    
     REFERENCE NUMERALS 
     
         
         
           
               1  reproducing apparatus 
               10  central operation area 
               20 A A-side operation area 
               20 B B-side operation area 
               21  jog dial 
               22  fader 
               31  browse switching button 
               41  device selection button 
               42  encoder 
               43  left button 
               44  right button 
               45  A-side load button 
               46  B-side load button 
               51  A-side disc insertion section 
               52  B-side disc insertion section 
               55  USB slot 
             D liquid crystal display 
           
         
       
    
     BEST MODES FOR CARRYING OUT THE INVENTION 
     A reproducing apparatus and a program therefor according to one embodiment of the invention will be explained in detail hereinbelow with reference to accompanying drawings. In the embodiment, the reproducing apparatus of the invention adapted to DJ equipment used for music performance by DJs is exemplified. 
       FIG. 1A  is a plan view of a reproducing apparatus  1  of the invention and  FIG. 1B  is an elevation view thereof. As shown in  FIG. 1A , a top surface of the reproducing apparatus  1  is divided into a central operation area  10  and a side operation area  20 . The central operation area  10  has a liquid crystal display unit  11 , a device selection unit  12 , a selection/sort unit  13 . Selection and sort of tracks (contents) for reproduction control at both side operation areas  20 A and  20 B is performed with operations of these respective units. 
     The liquid crystal display unit  11  is made up of a liquid crystal display D. Also, the device selection unit  12  has a plurality of device selection buttons  41  which is used for selecting a device (see an information recording medium  60 ,  FIG. 2 ) to be a generated object of a content list (see a second area E 2  in  FIG. 3 ) displayed on the liquid crystal display D. Further, the selection/sort operation unit  13  has an encoder  42 , a left button  43 , a right button  44 , an A-side load button  45  and a B-side load button  46 . 
     The encoder  42  is used to instruct a cursor to move in the content list or move to a lower hierarchy. The left button  43  is used to instruct to move to an upper hierarchy in the content list and the right button  44  is used to instruct to move to a lower hierarchy of the content list. The A-side load button  45  is used to sort a track selected from the content list to an A-side reproduction mechanism  191  and an A-side operation mechanism  201 , and the B-side load button  46  is used to sort a track selected from the content list to a B-side reproduction mechanism  192  and a B-side operation mechanism  202  (see  FIG. 2 ). 
     The side operation area  20  has the A-side operation area  20 A located at the left area and the B-side operation area  20 B located at the right area in the figure. The A-side operation area  20 A has a jog dial  21 A, a fader  22 A, an auxiliary display  23 A, a cue button  24 A and a play/pause button  25 A. The jog dial  21 A is so configured that it can adjust a reproduction state (such as reproduction volume) based on a user&#39;s operation or apply an effect (generation of scratch sound or the like) by detecting the user&#39;s operation (press and rotation). The fader  22 A is used to perform volume control (gain control of a power amplifier). The auxiliary display  23 A displays a title, reproduction time, BPM and the like of a track being reproduced. 
     A description of the B-side operation area  20 B is omitted because a structure thereof is identical to that of the A-side operation area  20 A, except that a browse switching button  31  is provided in a part of the B-side operation area  20 B (at a position adjacent to the central operation area  10 ). The browse switching button  31  is used to switch display types of the content list to a “file browse (folder display type)” or an “ID3 browse (category display type)” (see  FIGS. 3 and 4 ). Details thereof will be explained later. 
     Further, as shown in  FIG. 1B , the reproducing apparatus  1  has a power button  32  for switching ON/OFF of a power, an A-side disc insertion section  51 , a B-side disc insertion section  52 , an A-side eject button  53 , a B-side eject button  54  and a USB slot  55  (a first USB slot) at the front side thereof. 
     The A-side disc insertion section  51  and the B-side disc insertion section  52  are provided at the left side and the right side of the reproducing apparatus  1 , corresponding to positions of the A-side operation area  20 A and the B-side operation area  20 B, and each of which is inserted with an optical disc  61  (see  FIG. 2 ) such as a DVD or a CD. The A-side eject button  53  and the B-side eject button  54  are respectively used to eject optical discs from the A-side disc insertion section  51  and the B-side disc insertion section  52 . A USB memory  62  (see  FIG. 2 ) such as a USB flash memory or a USB hard disc is inserted in the USB slot  55 . 
     Though not especially shown, a USB slot (a second USB slot) having the same specification of the USB slot  55  and a USB slot (a PC slot) dedicated for connecting a personal computer  63  (refereed to a “PC  63 ”, hereinafter) are provided on a back side of the reproducing apparatus  1 . The above A-side disc insertion section  51 , the B-side disc insertion section  52 , the USB slot  55 , the two USB slots on the back side correspond to five buttons of the six device selection buttons  41 , and one of the devices to be a generated object of the content list is selected from devices respectively inserted therein. The remaining one device selection button  41  corresponds to a play list preliminary made up by a user (details thereof will be explained later). 
     Referring to  FIG. 2 , a control structure of the reproducing apparatus  1  will be explained. As shown in  FIG. 2 , the reproducing apparatus  1  has a reading unit  110 , a content list generation unit  120 , a content list display unit  130 , a reproduction/operation mechanism index unit  140 , a display type selection unit  150 , a content selection unit  160 , a content sort unit  170 , a sort result display unit  180 , a reproduction unit  190 , an operation unit  200  and an output unit  210 . 
     The reading unit  110  is used to read the information recording medium  60 , and has reading mechanisms such as an A-side disc drive  111 , a B-side disc drive  112  and a USB drive  113 . The optical disc  61  or the USB memory  62  are used as the information recording medium  60 , as described above. The reading unit  110  is also connected to the PC  63  via a cable having a USB terminal and is capable of reading contents stored in a hard disc of the PC  63 . The A-side disc drive  111  and the B-side disc drive  112  read the optical discs  61  inserted in the A-side disc insertion section  51  and the B-side disc insertion section  52 , respectively. The USB drive  113  physically has three drives and reads input data from the USB memory  62  inserted in each of the USB slots described above or from the PC  63 . 
     The content list generation unit  120  is used to generate the content list of tracks read from the information recording medium  60 , and has a CPU  121  to control the reproducing apparatus  1  integrally and a display control device  122  to perform display control for the liquid crystal display D as main devices. The content list generation unit  120  generates the content list per information recording medium  60  read by a plurality of reading mechanisms. 
     The content list display unit  130  is used to display the content list of the information recording medium  60  selected by the content selection unit  160  among content lists generated by the content list generation unit  120  on the liquid crystal display D (a display screen). In other words, a content list is displayed on the liquid crystal display D regardless whichever the reading mechanism reads the information recording medium  60 . 
     The reproduction/operation mechanism index unit  140  is used to index the reproduction mechanisms  191 ,  192  and the operation mechanisms  201 ,  202  which can be sorted by the content sort unit  170  based on a data type of the contents read by each reading mechanism. In the reproducing apparatus  1  of the embodiment, the contents can be reproduced only by corresponding reproduction mechanisms  191  and  192  in a case that the data type of the contents stored in the information recording medium  60  is other than MP3. Accordingly, whether the data type is MP3 or not is determined for the optical discs  61  read by the A-side disc drive  111  and the B-side disc drive  112 . When the data type is MP3, both of the reproduction mechanisms and the operation mechanisms are indexed as sortable reproduction mechanisms  191 ,  192  and operation mechanisms  201 ,  202 . In other words, when the data type is MP3, the contents read by the A-side disc drive  111  can be reproduced/operated by the B-side reproduction mechanism  192  and the B-side operation mechanism  202 . When the data type is not MP3, only the reproduction/operation mechanisms corresponding to the read drive are indexed as sortable reproduction/operation mechanisms. The index is performed by lighting up the A-side load button  45  and/or the B-side load button  46  (see  FIG. 1 ). More specifically, it means that the load buttons  45  and  46  which are not lit up at the time of operation for content selection can not be designated as sort destination. It is supposed that the information recording medium  60  read by reading mechanisms other than the A-side disc drive  111  and the B-side disc drive  112  has MP3 data type. Therefore, the contents read from the information recording medium  60  indexes both reproduction/operation mechanisms as sortable reproduction/operation mechanisms, without determining the data type. 
     The display type selection unit  150  is used to select either one of the “file browse (the folder display type)” and the “ID3 browse (the category display type)” as display type of the content list, and has the browse switching button  31  as a main device thereof. When the “file browse” is selected, the content list is displayed according to a hierarchy structure of the contents stored in the information recording medium  60 . When the “ID3 browse” is selected, the content list is displayed by category based on additional information (ID3 tag) added to each content. 
     The content selection unit  160  is used to select contents to be reproduced objects by the two reproduction mechanisms  191 ,  192  and to be an operated object by the two operation mechanisms  201 ,  202  from the content list displayed on the content list display unit  130 . More specifically, the content list for the information recording medium  60  is displayed on the content list display unit  130  by assigning the information recording medium  60 , and the contents to be reproduced objects of the two reproduction mechanisms  191 ,  192  and to be operated objects of the two operation mechanisms  201 ,  202  from the displayed content list. A selection operation is performed with the device selection buttons  41 , the encoder  42 , the left button  43  and the right button  44 . Details thereof will be explained later with reference to display examples ( FIGS. 3-10 ) of the liquid crystal display D. 
     The content sort unit  170  is used to sort the contents read by the reading unit  110  to the two reproduction mechanisms  191 ,  192  and the two operation mechanisms  201 ,  202  according to a selection result of the content selection unit  160 , and has the A-side load button  45  and the B-side load button  46  as main devices thereof. As described above, it is possible to sort to the reproduction mechanisms  191 ,  192  and the two operation mechanisms  201 ,  202  (reproduction/operation mechanisms corresponding to the load buttons  45  and  46  being lit) indexed by the reproduction operation mechanism index unit  140  as sort destination. 
     The sort result display unit  180  is used to display the sort result by the content sort unit  170  on the liquid crystal display D (a display screen). More specifically, the sort result is displayed by adding a symbol (“A” or “B”) showing the sorted reproduction/operation mechanisms in the content list displayed on the content list display unit  130  (see numeral  81  in  FIG. 10 ). 
     The reproduction unit  190  is used to reproduce contents and has two reproduction mechanisms (the A-side reproduction mechanism  191  and the B-side reproduction mechanism  192 ) which can reproduce simultaneously. More specifically, the reproduction unit  190  includes an audio signal reproduction processor (not shown) having a decoder, converter and the like. 
     The operation unit  200  is used to perform reproduction control to each content reproduced by each of the reproduction mechanisms  191 ,  192 , and has the two operation mechanisms  201 ,  202  corresponding to the two reproduction mechanisms  191 ,  192 . In this embodiment, the A-side operation mechanism  201  has the A-side jog dial  21 A, the A-side fader  22 A, the A-side CUE button  24 A and the A-side play/pause button  25 A. The B-side operation mechanism  202  has the B-side jog dial  21 B, the B-side fader  22 B, a B-side CUE button  24 B and a B-side play/pause button  25 B. 
     The output unit  210  is used to output audio signals reflected with the reproduction control result of the operation unit  200  to the reproduced tracks by the reproduction unit  190  to an output speaker  90  and the like, and has an audio output interface  211  (an analog output terminal or a digital output terminal) as a main device thereof. 
     Referring to  FIGS. 3 to 10 , display examples of the liquid crystal display D and an operation method of the central operation area  10  will be explained.  FIG. 3  shows a display example of the “file browse”. A summary structure of a GUI and a physical interface of the liquid crystal display D in common in both browses will be explained. Firstly, the GUI of the liquid crystal display D provided in an upper area of the central operation area  10 . The liquid crystal display D is divided into a first area E 1  to a third area E 3  in a row direction. 
     The first area E 1  is a reproduction mechanism display area, and titles and artist names of tracks loaded in the A-side reproduction mechanism  191  and the B-side reproduction mechanism  192  are displayed in the A-side display area E 11  and the B-side display area E 12  thereof. 
     The second area E 2  is a content list display area and has a hierarchy name display area E 21 , a left window area (a main display area) E 22  and a right window area (a sub-display area) E 23 . A hierarchy name of a hierarchy being currently displayed on the left window area E 22  is displayed in the hierarchy name display area E 21 , items of available hierarchies on which a cursor can move are displayed in the left window area E 22 , and contents of the item or the ID3 information of the track being selected in the left window area E 22  is displayed in the right window area E 23 . 
     The third area E 3  is a device tab display area, in which six device tabs  71  to  76  are displayed and one of the device tabs selected exclusively is highlighted. In the second area E 2  described above, the contents of the device selected here are expanded. 
     The device tabs are: a “DISC  1 ” tab  71 , a “DISC  2 ” tab  72 , a “USB  1 ” tab  73 , a “USB  2 ” tab  74 , a “PC” tab  75  and a “PLAYLIST” tab  76 . The “DISC  1 ” tab  71  and the “DISC  2 ” tab  72  correspond to the A-side disc drive  111  and the B-side disc drive  112 , respectively. Further, the “USB  1 ” tab  73  corresponds to a USB drive connected to the USB slot  55 , the “USB  2 ” tab  74  corresponds to a USB drive connected to the USB slot (not shown) on the back side of the reproducing apparatus  1 , and the “PC” tab  75  corresponds to the USB drive (for PC) connected to a USB slot (not shown) on the back side of the reproducing apparatus  1 , respectively. Further, the “PLAYLIST” tab  76  is adapted to correspond to a non-volatile memory (not shown) storing a play list prepared by the user in the reproducing apparatus  1 . The contents read out from the non-volatile memory can be displayed in the second area E 2  as content list. This play list can include tracks selected from a content list of the other devices by a predetermined operation. 
     Next, the physical interface provided in a lower area of the central operation area  10  will be explained. The numeral  41  indicates device selection buttons. Six device selection buttons  41  are provided to correspond to the device tabs  71 - 76  displayed on the liquid crystal display D. 
     The numeral  42  indicates the encoder having a push function. The encoder  42  can move a selection cursor in the second area E 2  in a vertical direction when the user rotates it. Further, when the user pushes the encoder  42 , the selection cursor  42  can be moved to a lower hierarchy of a selected item. 
     The numeral  43  indicates the left button. When the left button  43  is pushed, the selection cursor can be moved to an upper hierarchy of the selected item. The numeral  44  indicates the right button. When the right button  44  is pushed, the selection cursor can be moved to a lower hierarchy of the selected item. 
     The numeral  45  indicates the A-side load button. When the A-side load button  45  is pushed, a selected track can be set in the A-side reproduction mechanism  191  and the A-side operation mechanism  201 . The numeral  46  indicates the B-side load button. When the B-side load button  46  is pushed, the selected track can be set in the B-side reproduction mechanism  192  and the B-side operation mechanism  202 . The A-side load button  45  and the B-side load button  46  are lighted on/off. The selection by the above push operations can be available (the track can be set in each reproduction mechanism  191 ,  192 ) only when the buttons  45  and  46  are lit on. 
     It may be possible to have a structure in which a plurality of tracks are sorted (spooled) to each of the reproduction/operation mechanisms by repeating the selection operation with the above buttons  41 - 44  and the sort operation with the load buttons  45  and  46 . In this case, each of the reproduction mechanisms  191  and  192  can reproduce tracks in an order of being spooled once (or selected from the spooled tracks). 
     The above explanation is in common for both browses. Referring to  FIG. 3 , a GUI of the “file browse” will be explained. As display contents of the liquid crystal display D depending on browses are varied only in the second area E 2 , only the second area E 2  will be explained. A folder name currently being displayed in the left window area E 22  is displayed in the hierarchy name display area E 21  of the second area E 2  at the “file browse”. The contents of the folder are displayed in the left window area E 22 , and the contents of the selected folder are displayed in the right window area E 23 . In a case that a final hierarchy is displayed in the left window area E 22 , ID3 information of the track is displayed in the right window area E 23  (see  FIG. 8 ). Thus, the content list at the “file browse” includes folders of a plurality of hierarchies and the ID3 information. 
     Referring to screen transitions of  FIGS. 4-10 , an operation method at the “ID3 browse” will be explained. First of all, referring to  FIG. 4 , a GUI of the “ID3 browse” will be explained. A device name selected by one of the device selection buttons  41  is displayed in the hierarchy name display area E 21  of the second area E 2  at the “ID3 browse” in an initial screen (a category selection screen) thereof. A category list is displayed in the left window area E 22  and the selection candidates of the selected category are displayed in the right window area E 23 . 
     As a category, either one of a “genre”, an “artist”, an “album”, a “title” and a “play list” can be selected. When the “genre” is selected at first, the “artist”, the “album”, and the “title” are selected sequentially. When the “artist” is initially selected, the “album” and the “title” are selected in sequence. When the “album” is selected, then the “title” is selected. When the “title” is selected, the title is directly selected. Further, the “play list” is firstly selected, selection is performed within the play list recorded in the “DISC  1 ”. 
     A state of the screen after transition will be explained with reference to  FIG. 5 , where the right button  44  is pushed in the state shown in  FIG. 4  (in the state that the “genre” is designated by the cursor (highlighted). It may be possible to move to the lower hierarchy by pushing the encoder  42 . Further, as the left button  43  is pushed, it is possible to move to one upper hierarchy (the category selection screen). When the “genre” is selected as category, the screen transits to a genre selection screen as shown in  FIG. 5 . A category name (“genre”) is displayed in the hierarchy name display area E 21 . Selection candidates of the genre are displayed in the left window area E 22 . Selection candidates for the genre are displayed in the right window area E 23 . 
     In this case, a screen state after transition will be explained with reference to  FIG. 6 , where the right button  44  is pushed in the state shown in  FIG. 5  (in the state that the “techno” is designated with the cursor). When the “techno” is selected as a genre, as shown in  FIG. 6 , the screen transits to an artist selection screen. A genre name (“techno”) is displayed in the hierarchy name display area E 21 . Selection candidates of artists associated with techno are displayed in the left window area E 22 . Album names of the artist are displayed in the right window area E 23  as selection candidates. 
     A state of the screen after transition will be explained with reference to  FIG. 7 , where the right button  44  is pushed in the state shown in  FIG. 6  (in the state that an “artist  1 ” is designated with the cursor). When the “artist  1 ” is selected as an artist, as shown in  FIG. 7 , the screen transits to an album selection screen. An artist name (“artist  1 ”) is displayed in the hierarchy name display area E 21 . Album names of the “artist  1 ” are displayed in the left window area E 22  as selection candidates. Title names recorded in the album are displayed in the right window area E 23  as selection candidates. 
     A state of the screen after transition will be explained with reference to  FIG. 8 , where the right button  44  is pushed in the state shown in  FIG. 7  (in the state that the “album  1 ” is designated with the cursor). When the “album  1 ” is selected as an album, as shown in  FIG. 8 , the screen transits to a title selection screen. An album name (“album  1 ”) is displayed in the hierarchy name display area E 21 . Title names recorded in the “album  1 ” are displayed as selection candidates in the left window area E 22 . ID3 information of the title is displayed in the right window area E 23 . 
     In the title selection screen, the title name, the artist name, the album name and the genre name are displayed as ID3 information, but it may be also possible to display a comment input by the user per title or artist. The comment information can be stored in the non-volatile memory (not shown) in the reproducing apparatus  1  or in a predetermined area of the information recording medium  60 . It may be also possible to record usage history of each content at selecting, sorting, or stopping reproduction of the content, and to display it as usage history information of each content. Further, it may be possible to display information such as BPM or key information which can be detected automatically from content data of the track, together with the ID3 information. 
     A state of the screen after transition will be explained with reference to  FIG. 9 , where the cursor is moved to two downward position from the state shown in  FIG. 8  (where the “track  1 ” is designated by the cursor) by rotating the encoder  42  in a clockwise direction. When the selection candidates are changed by the movement of the cursor, ID3 information in the right window area E 23  are changed according to the movement so as to display ID3 information of the selected candidate. Thus, a content to be a selected object is determined by the rotation of the encoder  42 . 
     A state of the screen after transition will be explained with reference to  FIG. 10 , where the A-side load button  45  is pushed so as to set the content to be the selected object in the A-side reproduction mechanism  191  and the A-side operation mechanism  201  in the state shown in  FIG. 9  (in the state that the “track  3 ” is designated by the cursor). Note that the contents of the “DISC  1 ” are recorded in MP3 data type, and the A-side load button  45  and the B-side load button  46  both are in a sortable state (lighting-on state). 
     When the content is sorted to either one of the A-side or the B-side reproduction/operation mechanisms, a symbol  81  showing the sort result (“(A)” in  FIG. 10 ) is displayed (as a head mark) at a head of the track name. The content of the A-side display area E 11  is changed to the title name and the artist name of the selected content. Therefore, the A-side display area E 11  and the B-side display area E 12  also function as display for showing the sort result. 
     In a case that a plurality of tracks can be spooled, the above example is applied in that the head mark is displayed when the load buttons  45  and  46  are pushed. On the other hand, in terms of the change of the A-side display area E 11  or the B-side display area E 12 , timings for the change vary according to whether the contents reproduced by the corresponding reproduction mechanisms  191  and  192  or the contents being spooled exist or not. In other words, in a case that the contents being reproduced or spooled do not exist, the A-side display area E 11  is changed when the load button  45  or  46  is pushed. On the other hand, when such contents exist, the A-side display area E 11  is changed at the beginning of reproducing the content. 
     As described above, according to the reproducing apparatus  1  of the embodiment, the user can perform the selection operation and the sort operation for the contents only seeing the liquid crystal display D, because the content list for selecting the contents to be the reproduced objects of the two reproduction mechanisms  191 ,  192  and to be the operated objects of the two operation mechanisms  201 ,  202  is displayed on the same liquid crystal display D. This prevents erroneous operations and can enhance operability. Further, as the sort result of the contents is displayed on the same liquid crystal display D, the user can acknowledge that the content is reproduced by which reproduction mechanism  191  or  192  and can be operated by which operation mechanism  201  or  202 , leading to high usability. Further, as the operation mechanisms (the jog dials  21 A,  21 B, and the faders  22 A,  22 B) for controlling reproduction of the content to be reproduced are provided separately in correspondence to each of the reproduction mechanisms  191 ,  192 , independent reproduction control can be performed, thereby various music expressions can be achieved. 
     As the reproducing apparatus  1  has a plurality of reading mechanisms, it is possible to select contents to be the reproduced objects and the operated objects (objects for reproduction control) from a number of contents. Further, as the content list is generated per information recording medium  60 , a great number of contents can be sorted per information recording medium  60 , which makes it possible to retrieve the contents easily. 
     As reproduction/operation mechanisms which are sortable are indexed by a state of each of the load buttons  45 ,  46 , the sort can be performed based on the index. Therefore, the user does not need to determine whether the mechanisms can be sorted or not with checking a data type of the content. 
     In the above embodiment, the operation method at the “ID3 browse” is explained mainly, but in the case of the “file browse”, the ID3 information display and the sort destination display are the same. 
     Further, in the embodiment above, the reproducing apparatus  1  having the two reproduction mechanisms  191  and  192  is exemplified, but three or more reproduction mechanisms may be provided. Though only reproduction of audio signals is mentioned, it is also possible to adapt to reproduce video signals. Accordingly, it is possible to adapt the invention to DVJ equipment (equipment including DJ equipment used for acoustic performance by DJs and VJ equipment used for video performance by visual jockeys or video jockeys (VJs)). 
     The sort result is displayed as a head mark of each content in the content list and as character information on the A-side display area All and the B-side display area A 12 , but it may be possible, even in a case that a plurality of tracks can be spooled, to display the sort result to the A-side reproduction mechanism  191  and the A-side operation mechanism  201  (reproduction order  1 : track  1 , reproduction order  2 : track  2 , . . . ) and the sort result to the B-side reproduction result  192  and the B-side operation mechanism  202  as character information on a predetermined area of the liquid crystal display D. Also, in the case that a plurality of tracks can be spooled, a reproduction order (“1”, “2” . . . or “NEXT”) may be displayed with the symbol (“A” or “B”) showing a sort destination as a head mark of each content. 
     In the embodiment above, the reproduction unit  190  has the two reproduction mechanisms  191 ,  192 , but one memory for internally storing the reproduced data may be provided, meaning that those may not necessarily be separated physically. In other words, only if two (a plurality of) contents can be reproduced simultaneously, only one reproduction mechanism may be necessary. 
     In the embodiment above, the switching method of the folder display type and the category display type with the browse switching button  31  is explained, but it may be possible to switch them selectively by displaying the folder and the category in a same line. 
     In the embodiment above, contents having MP3 type are explained, but other types such as AAC, WMA, WAV, MPX (X=2, 4 etc), OGG, VQF may be used. 
     In terms of the sort result, the symbol (“A” or “B”) showing the sort destination is displayed in the content list, but it may be possible to add other symbols (such as “1” or “2”, or “←” or “→”, “&lt;” or “&gt;”). Also, it may possible to add text information such as “A-side” or “B-side” in place of the symbol. Thus, any type of added information may be used. 
     In a case that the liquid crystal display D is a color display, it may be possible to show the sort destination by color-coding the title name of the selected content. In this case, in terms of the reproduction mechanism display area E 1 , it is preferable that the sort destination be displayed by changing display colors of the A-side display area E 11  and the B-side display area E 12  so that the user can definitely acknowledge the sort destination. In this case, it is also preferable that the sort destination of the content be displayed as easily recognizable by setting the A-side with red and the B-side with blue in advance (or, to be recognized intuitively, each operation area  20 A,  20 B or jog dial  21 A,  21 B of the apparatus is colored with red and blue, or colors of characters and background of the A-side display area E 11  and the B-side display area E 12  are changed to red/blue by electric spectaculars of each color). Moreover, in terms of the sort result, it may be possible to display the sort destination by changing display modes such that the content title is displayed in blinking, a font thereof is changed. 
     Also, each unit and function of the reproducing apparatus  1  shown in the example above can be provided as a program. The program can also be stored and provided in a recording medium (not shown). Examples of such recording medium include: a CD-ROM, a flash ROM, a memory card (a compact flash (trade mark), a smart media, a memory stick, an SD card and the like), a compact disc, a magneto-optical disc, a digital versatile disk, a flexible disc, and a hard disc. Those can be used as the information recording medium  60  storing contents. 
     The configuration, the processing steps, functions and the like of the reproducing apparatus  1  may not be limited to the above embodiment, but may be modified suitably within the spirit and scope of the invention.