Abstract:
A reproduction device including a reproduction unit configured to reproduce content data including at least one of audio, video, and text for which attribute data is assigned for each of a different plurality of attributes; a display unit; and a control unit configured to make the display unit display a playback screen containing at least one attribute data among the plurality of attribute data assigned to the content data when reproducing the content data and, when one attribute data among the attribute data composing the playback screen is selected, switch the display content of the content from the playback screen to the list relating to the selected attribute data.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     The present invention contains subject matter related to Japanese Patent Application No. 2005-309796 filed in the Japan Patent Office on Oct. 25, 2005, the entire contents of which being incorporated herein by reference.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of Invention  
         [0003]     The present invention relates to a reproduction device and display control method enabling a playback screen to be switched to a list screen corresponding to different attributes.  
         [0004]     2. Description of the Art  
         [0005]     In recent years, the increasingly greater capacity of recording media and advances made in technology for compression of music, movies, still images, etc. have made it possible to store an enormous amount of content data in the recording medium of a portable player. The increase in the amount of the content data which can be stored in recording media in this way has made it necessary to develop a system for efficiently searching for and displaying the content data desired by the user on the screen. As one such method, there can be explained the method of searching for track names, album names, and artist names of the content data by their initials. For example, when searching by the artist name, the user finds the desired artist name from an alphabetical list of artist names.  
         [0006]     In such a portable player, the list of attribute data is hierarchically structured. The user searches for content data desired to be played by for example selecting attributes of tracks to be played one by one from lists of attribute data such as “GENRE”, “ARTIST NAME”, “ALBUM NAME”, and “TRACK NAME”. Many such portable players of the art have been designed to display information concerning the content data being played, for example, the artist name, album name, track name, and other attribute data, while playing the content data retrieved by the above procedure.  
         [0007]     In such a portable player, however, where it is desired to find and play other content data while playing certain content data, that is, for example, where it is desired to play content data of another album of the same artist as the content data being played, it is necessary to return once to the uppermost menu screen and then again retrieve the content data or redo the retrieval by going back over the lists used for reaching the content data being played (namely in the above case, select another album by going back over the lists in the sequence of “TRACK NAME” and “ALBUM NAME”). Namely, in portable players of the art, there has been no system enabling selection on the playback screen. It was only possible to return to the uppermost menu screen or return to the immediately preceding list screen.  
         [0008]     As an example of the art, see Japanese Patent Publication (A) No. 2001-76415.  
       SUMMARY OF THE INVENTION  
       [0009]     In the present invention, it is therefore desirable to provide a reproduction device and display control method enabling a playback screen to be switched to a list screen corresponding to different attributes.  
         [0010]     According to a first embodiment of the present invention, there is provided a reproduction device including a reproduction unit configured to reproduce content data including at least one of audio, video, and text for which attribute data is assigned for each of a different plurality of attributes; a display unit; a control unit configured to make the display unit display a playback screen containing at least one attribute data among the plurality of attribute data assigned to the content data when reproducing the content data and, when one attribute data among the attribute data composing the playback screen is selected, switch the display content of the content from the playback screen to the list relating to the selected attribute data.  
         [0011]     Preferably, the device further includes an input part for receiving as input an operation content, and the control unit makes the display unit display a playback screen containing at least one attribute data among the plurality of attribute data assigned to the content data when reproducing the content data and switches the display content of the display unit from the playback screen to the list relating to the selected attribute data when one attribute data among the attribute data composing the playback screen is selected based on the operation content input from the input part.  
         [0012]     More preferably, the display unit displays a cursor on the playback screen, and the control unit moves the cursor based on the operation content input from the input part and makes the display unit display the list relating to the attribute data selected by the cursor.  
         [0013]     Still more preferably, the control unit displays the attribute data by scrolling when the attribute data at which the cursor is arranged, contains a predetermined number or more of letters.  
         [0014]     Preferably, the control unit controls the reproduction unit embodiment continue the reproduction of the content data being reproduced even after the display content of the display unit is switched to a list corresponding to the specific attribute during reproduction of the content data.  
         [0015]     More preferably, after switching the display content of the display unit to the list corresponding to the specific attribute during reproduction of the content data, the control unit continues the reproduction of the content data being reproduced until reproduction of other content data is instructed.  
         [0016]     Preferably, when switching the display content of the display unit from the playback screen to the list relating to the selected attribute data, the control unit places a cursor at attribute data of certain selected content data in the list.  
         [0017]     Preferably, when any item of the list being displayed on the display unit is selected, the control unit makes the reproduction unit start the reproduction of the content data corresponding to the selected item, and switches the display content of the display unit from the list to the playback screen containing a plurality of attribute data assigned to the content data.  
         [0018]     Preferably, the control unit manages the content data by classifying it into a plurality of hierarchical levels based on the plurality of attributes, makes the display unit display any list of the plurality of lists composed responsive to the attributes, and, when any item is selected from among the displayed lists, makes the reproduction unit reproduce the content data corresponding to the selected item and switches the display content from the list to the playback screen containing the plurality of attribute data assigned to the content data, and, when one attribute data is selected from among the plurality of attribute data on the playback screen, switches the playback screen to the selected attribute data.  
         [0019]     More preferably, the plurality of attributes are at least genres, artists, and track names of the content data, and the control unit manages the content data by classifying the same to lists of a genre list, an artist list, and a track name list based on the attribute information, makes the display unit display any list of the lists, and, when any item is selected from among the displayed lists, makes the reproduction unit reproduce the content data corresponding to the selected item and switches the display content from the list to the playback screen containing the genre, artist name, and track name assigned to the content data, and, when the artist name is selected from among the genre, artist name, and track name on the playback screen, switches the playback screen to the artist list having the selected artist name as one of items.  
         [0020]     More preferably, when one attribute data is selected from among the plurality of attribute data on the playback screen, the control unit makes the display unit display a list other than the list displayed immediately before the switching to the playback screen.  
         [0021]     According to a second embodiment of the invention, there is provided a display control method when reproducing content data to which the attribute data concerning different plurality of attributes are assigned, including the steps of making a display unit display a playback screen containing at least one attribute data among the plurality of attribute data assigned to the content data to be reproduced and switching the display content of the display unit from the playback screen to a list relating to selected attribute data when one attribute data is selected from among the attribute data composing the playback screen.  
         [0022]     Preferably, the method further includes the steps of detecting operation content input from an input unit, selecting one attribute data among attribute data composing the playback screen based on the operation content, and switching the display content of the display unit from the playback screen to a list relating to the selected attribute data.  
         [0023]     Preferably, the method further includes the steps of, displaying a cursor on the playback screen, moving the cursor based on the operation content input from the input unit, and when one attribute data among the attribute data composing the playback screen is selected by the cursor, switching the display content of the display unit from the playback screen to the list relating to the selected attribute data.  
         [0024]     More preferably, the method further includes a step of displaying attribute data by scrolling when attribute data at which the cursor is arranged, contains a predetermined number or more of letters.  
         [0025]     Preferably, the method further includes a step of starting reproduction of selected content when one attribute data among the attribute data composing the playback screen is selected and continuing the reproduction of the content data being reproduced even after switching the display content of the display to the list corresponding to the specific attribute during reproduction of the content data.  
         [0026]     More preferably, the method further includes a step of continuing the reproduction of the content data being reproduced after switching the display content of the display to the list corresponding to the specific attribute during reproduction of the content data until the reproduction of other content data is instructed.  
         [0027]     Preferably, the method further includes a step of arranging the cursor at attribute data of selected content data as one item of the list when switching the display content of the display from the playback screen to the list relating to the selected attribute data.  
         [0028]     Preferably, the method further includes a step of starting reproduction of content data corresponding to a selected item when any item of the list displayed on the display unit is selected, and switching the display content of the display from the list to the playback screen containing the plurality of attribute data assigned to the content data.  
         [0029]     Preferably, the method further includes the steps of managing the content data classifying the same into a plurality of hierarchical levels based on the plurality of attributes, making the display unit display any list of the plurality of lists composed responsive to the attributes, and when any item is selected from among the displayed lists, reproducing content data corresponding to the selected item, switching the display content from the list to the playback screen containing the plurality of attribute data assigned to the content data, and when one among the plurality of attribute data in the playback screen is selected, switching the playback screen to the list relating to the selected attribute data.  
         [0030]     More preferably, the plurality of attributes are at least genres, artists, and track names of content data, and the method further includes the steps of managing the content data classifying the same into lists of a genre list, an artist list, and a track name list based on the attribute information, making the display unit display any list of the lists, reproducing content data corresponding to a selected item when any item is selected from among displayed lists, switching the display content from the list to the playback screen containing the genre, artist name, and track name assigned to the content data, and when the artist name among the genre, artist name, and track name on the playback screen is selected, and switching the playback screen to the artist list having the selected artist name as one item.  
         [0031]     More preferably, the method further includes, when one among the plurality of attribute data on the playback screen is selected, a step of making the display unit display a list other than the list displayed immediately before the switching to the playback screen.  
         [0032]     According to the present invention, a reproduction device and display control method enabling a playback screen to be switched to a list screen corresponding to different attributes can be provided.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0033]     These and other objects and features of the present invention will become clearer from the following description of the preferred embodiments given with reference to the attached drawings, wherein:  
         [0034]      FIG. 1  is a view of the configuration of a portable audio player according to an embodiment of the present invention;  
         [0035]      FIGS. 2A  to  2 C are views of an example of side surfaces and a front surface of a case of a portable audio player;  
         [0036]      FIG. 3  is a table for explaining attributes of track data and attribute data;  
         [0037]      FIG. 4  is a diagram showing the correlation and transition of screens displayed on a liquid crystal display (LCD) panel of the portable audio player;  
         [0038]      FIG. 5  is a view showing an example of a main menu screen;  
         [0039]      FIG. 6  is a view showing an example of a music library screen;  
         [0040]      FIG. 7  is a view showing the transition of a screen when searching through all tracks;  
         [0041]     FIGS.  8 A and  8 AB are views showing the transition of a screen when searching in units of albums;  
         [0042]      FIGS. 9A  to  9 C are views showing the transition of a screen when searching based on artists;  
         [0043]      FIGS. 10A  to  10 D are views showing the transition of a screen when searching from genres;  
         [0044]      FIGS. 11A and 11B  are views showing the transition of a screen when searching based on ratings assigned by the user in the past;  
         [0045]      FIGS. 12A  to  12 C are views showing the transition of a screen when searching according to the year of release of the track or album etc.;  
         [0046]      FIGS. 13A and 13B  are views showing the transition of a screen when selecting from among albums or tracks recently added to a hard disk drive (HDD);  
         [0047]      FIGS. 14A  to  14 F are views showing a playback screen and the transition of the screen according to an operation of the user;  
         [0048]      FIGS. 15A  to  15 E are views for explaining a scroll display of attribute data on the playback screen;  
         [0049]      FIG. 16  is a view for explaining a scroll display;  
         [0050]      FIG. 17  is a flow chart showing an example of operation of the portable audio player; and  
         [0051]      FIG. 18  is a diagram showing an example of the front surface of the case of a remote controller. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0052]     Below, a portable audio player according to an embodiment of the present invention will be explained.  
         [0053]      FIG. 1  is a view of the overall configuration of a portable audio player  1  according to an embodiment of the present invention. As shown in  FIG. 1 , the portable audio player  1  has for example a headphone terminal  11 , audio reproduction unit  12 , LCD panel  13 , central processing unit (CPU)  14 , input device  15 , synchronous dynamic random access memory (SDRAM)  16 , flash memory  17 , HDD  18 , and universal serial bus (USB) interface  19  all connected via for example a data line  10 .  
         [0054]     The audio reproduction unit  12  outputs track data decoded by the CPU  14  in the form of an audio signal and plays back the track via the headphone terminal  11 . Note that the track data of the present embodiment is an example of the content data of the present invention. The LCD panel  13  is provided on for example the front surface of a case of the portable audio player  1  and displays a variety of screens under the control of the CPU  14 . The main screens displayed on the LCD panel  13  include for example a menu screen, initial search screen, setting screen, playback screen, and history screen. These screens are switched by the operation of the user via the input device  15 . Further, the LCD panel  13  has for example a touch panel. A location on the screen touched by the user by his or her finger etc. is detected, and a detected location signal indicating the location is output to the CPU  14 .  
         [0055]     The input device  15  is, as shown in  FIGS. 2A  to  2 C, configured as various keys provided on the case of the portable audio player  1  and operated by the user.  FIGS. 2A  to  2 C are views showing example of the side surfaces and the front surface of the case of the portable audio player  1 . That is,  FIG. 2A  and  FIG. 2C  are views showing examples of the side surfaces of the portable audio player  1 , while  FIG. 2B  is a view showing an example of the front surface of the portable audio player  1 .  
         [0056]     As shown in  FIG. 2A , one side surface of the portable audio player  1  is provided with the headphone terminal  11  and a HOLD key  22 . As shown in  FIG. 2B , the front surface of the portable audio player  1  is provided with the LCD panel  13 , a cross key  27 , a BACK key  28 , a VIEW key  29 , and a MENU key  30 . The cross key  27  is configured by an up key  27   a,  a left key  27   b,  a down key  27   c,  a right key  27   d,  and an ENTER key  27   e.  As shown in  FIG. 2C , the other side surface of the portable audio player  1  is provided with a rewind key  24 , a play pause key  25 , a forwarding key  26 , and a volume adjustment dial  23 . The SDRAM  16  temporarily stores the data etc. relating to the processing of the CPU  14 . The flash memory  17  stores for example a program PRG for defining the operation of the CPU  14 .  
         [0057]     The HDD  18  has a storage capacity of for example several gigabytes to several tens of gigabytes and stores content data compressed by various compression methods or uncompressed track data etc. Further, the HDD  18  stores various play lists prepared by the CPU  14 . The USB interface  19  is connected with the personal computer  3  and inputs/outputs data between the device and the personal computer  3 . The data to be input and output here is for example track data, content data other than track data, list data, etc.  
         [0058]     The CPU  14  centrally controls the operation of the portable audio player  1  of the present embodiment based on the program PRG read out from the flash memory  17 . Further, the CPU  14  decodes the track data selected by the user and outputs it to the audio reproduction unit  12 .  
         [0059]     Note that the input device  15  and the touch panel of the LCD panel  13  of the present embodiment are examples of the input unit of the present invention, the LCD panel  13  of the present embodiment is an example of the display unit of the present invention, the audio reproduction unit  12  of the present embodiment is an example of the reproduction unit of the present invention, and the CPU  14  of the present embodiment is an example of the control unit of the present invention.  
         [0060]     Below, the list data corresponding to the different attributes and the list screens will be explained.  FIG. 3  is a table for explaining the attributes of the track data and the attribute data. As shown in  FIG. 3 , each track data has attribute data relating to different attributes. Here, “attribute” means for example the artist name, album name, genre name, and track name, while “attribute data” means data relating to the attribute.  
         [0061]      FIG. 4  is a diagram showing the correlation of the list screens and the operation method. In  FIG. 4 , “ENTER” means operation of the ENTER key  27   e,  “BACK” means operation of the BACK key  28 , “DOWN” means operation of the down key  27   c,  and “UP” means operation of the up key  27   a.  Further, in each square indicating a screen, the number of the corresponding drawing and the title of each screen are described.  
         [0062]     As shown in  FIG. 4 , the portable audio player  1  has a list having a hierarchical structure. Each list corresponds to an attribute.  
         [0063]     Below, the procedures from the main menu screen until the track to be played is reached will be explained.  
         [0064]     The CPU  14  displays for example the main menu screen shown in  FIG. 5  on the LCD panel  13 . The main menu screen shown in  FIG. 5  has for example a play button, favorite button, shuffle button, initial search button, music library button, history button, equalizer button, and setting button. The CPU  14  switches the main menu screen to the screen corresponding to each button by input by the user via the input device  15  or the touch panel of the LCD panel  13 .  
         [0065]     The inverted black/white button in  FIG. 5  means the button selected by the input device  15  at present and moves corresponding to the input of the cross keys  27   a  to  27   d.  The inverted black/white button is selected by the ENTER key  27   e.  Further, the button may also be selected by directly depressing the button by a finger etc. via the touch panel of the LCD panel  13 . The same operation method may also be used for the following screens. Below, the case where the music library button is selected on the menu screen will be explained.  
         [0066]     When the music library button is selected, the CPU  14  switches the screen of the LCD panel  13  to the music library screen shown in  FIG. 6  for display.  FIG. 6  is a view showing an example of the music library screen. The music library screen shown in  FIG. 6  has for example an all songs button for displaying all track data as one list, an albums button for displaying a list of albums, an artists button for displaying a list of artists, a genres button for displaying a list of genres, a rating button for selection by rating (scoring), a year of release button for displaying a list classified according to the year of release, and a new tracks button for displaying a list of the track data stored in the HDD  18  recently.  
         [0067]     The CPU  14  allows the user to select and determine options by moving the inverted white/black button of the music library screen shown in  FIG. 6  by input via the input device  15  or the touch panel of the LCD panel  13  and displays a screen corresponding to the determination of the user.  
         [0068]     When the all songs button is selected on the music library screen shown in  FIG. 6 , the CPU  14  displays the all music list screen shown in  FIG. 7  on the LCD panel  13 .  FIG. 7  is a view showing the transition of the screen when searching through all songs. The all music list screen shown in  FIG. 7  is a screen displaying an alphabetical list of the names of all tracks stored in the HDD  18 . Here, it is also possible to display not the tracks stored in the HDD  18 , but the names of tracks stored in an external server etc. When a track is selected on the all music list screen shown in  FIG. 7 , the playback screen of  FIG. 14A  is displayed, the CPU  14  decodes the selected track and sends it to the portable audio player  12 , and the portable audio player  12  plays the selected track and outputs it from the headphone terminal  11 .  
         [0069]     When the album button is selected on the music library screen shown in  FIG. 6 , the CPU  14  displays the album list screen as shown in  FIGS. 8A  on the LCD panel  13 .  FIG. 8A  and  FIG. 8B  are views showing the transition of the screen when searching in units of albums. The album list screen shown in  FIG. 8A  is a screen displaying an alphabetical list of all album names stored in the HDD  18 , while the track list screen shown in  FIG. 8B  is a screen for displaying a list of tracks recorded in the album selected on the album list screen shown in  FIG. 8A . When an album is selected on the album list screen shown in  FIG. 8A , the CPU  14  displays a list of the tracks recorded in the selected album, that is, the track list screen shown in  FIG. 8B , on the screen of the LCD panel  13 . When a track is selected on the track list screen shown in  FIG. 8B , the playback screen of  FIG. 14A  is displayed, the CPU  14  decodes the selected track and sends it to the portable audio player  12 , and the portable audio player  12  plays and outputs the same from the headphone terminal  11 .  
         [0070]     When the artists button is selected on the music library screen shown in  FIG. 6 , the CPU  14  displays the artist list screen as shown in  FIGS. 9A  on the LCD panel  13 .  FIG. 9A ,  FIG. 9B , and  FIG. 9C  are views showing the transition of a screen when searching based on the artist. The artist list screen shown in  FIG. 9A  is a screen displaying an alphabetical list of artists of all tracks stored in the HDD  18 . The album list screen shown in  FIG. 9B  is a screen for displaying an alphabetical list of albums of the artist selected on the artist list screen of  FIG. 9A , while the track list screen shown in  FIG. 9C  is a screen for displaying a list of tracks recorded in the album selected on the album list screen shown in  FIG. 9B . When an artist is selected on the artist list screen shown in  FIG. 9A , the CPU  14  displays the album list screen of that artist shown in  FIG. 9B  on the LCD panel  13 . When an album is selected on the album list screen shown in  FIG. 9B , the CPU  14  displays the track list screen shown in  FIG. 9C  on the LCD panel  13 . When a track is selected on the track list screen shown in  FIG. 9C , the playback screen of  FIG. 14A  is displayed, the CPU  14  decodes the selected track and sends it to the portable audio player  12 , and the portable audio player  12  plays and outputs the same from the headphone terminal  11 .  
         [0071]     When the genres button is selected on the music library screen shown in  FIG. 6 , the CPU  14  displays the genre list screen shown in  FIG. 10A  on the LCD panel  13 .  FIG. 10A ,  FIG. 10B ,  FIG. 10C , and  FIG. 10D  are views showing the transition of the screen when searching from the genres. The genres selection screen shown in  FIG. 10A  is the screen displaying the names of different genres in alphabetical order. The artist list screen shown in  FIG. 10B  is a screen displaying an alphabetical list of artists of the genre selected on the genre selection screen. The album list screen shown in  FIG. 10C  is a screen displaying an alphabetical list of albums of the artist selected on the artist list screen of  FIG. 10B , while the track list screen shown in  FIG. 10D  is a screen displaying a list of tracks recorded in the album selected on the album list screen shown in  FIG. 10C . When a genre is selected on the genre list screen shown in  FIG. 10A , the CPU  14  displays the artist list screen of that genre shown in  FIG. 10B  on the LCD panel  13 . When an artist is selected on the artist list screen shown in  FIG. 10B , the CPU  14  displays the album list screen shown in  FIG. 10C  on the LCD panel  13 . When an album is selected on the album list screen shown in  FIG. 10C , the CPU  14  displays the track list screen shown in  FIG. 10D  on the LCD panel  13 . When a track is selected on the track list screen shown in  FIG. 10D , the playback screen of  FIG. 14A  is displayed, the CPU  14  decodes the selected track and sends it to the portable audio player  12 , and the portable audio player  12  plays and outputs it from the headphone terminal  11 .  
         [0072]     When the rating button is selected on the music library screen shown in  FIG. 6 , the CPU  14  displays the rating screen as shown in  FIG. 11A  on the LCD panel  13 .  FIG. 11A  and  FIG. 11B  are views showing the transition of the screen when searching based on ratings assigned by the user in the past. The rating screen shown in  FIG. 11A  is a screen for displaying the score (rating). This rating is previously assigned to each track by the user by for example a five-step evaluation and indicates the degree by which the user favors each track. The music list screen shown in  FIG. 11B  is a screen displaying an alphabetical list of tracks having the rating selected on the rating screen shown in  FIG. 11A . When the rating (represented by the number of ★ in  FIG. 11A ) is selected on the rating screen shown in  FIG. 11A , the CPU  14  displays the music list screen shown in  FIG. 11B  for the corresponding rating on the LCD panel  13 . Here, the rating is previously assigned by the user. When a track is selected on the music list screen shown in  FIG. 11B , the playback screen shown in  FIG. 14A  is displayed, the CPU  14  decodes the selected track and sends it to the portable audio player  12 , and the portable audio player  12  plays and outputs the same from the headphone terminal  11 .  
         [0073]     When the year of release button is selected on the music library screen shown in  FIG. 6 , the CPU  14  displays the year of release selection screen as shown in  FIG. 12A  on the LCD panel  13 .  FIG. 12A ,  FIG. 12B , and  FIG. 12C  are views showing the transition of the screen when searching according to the year in which a track or album etc. was released. The year of release selection screen shown in  FIG. 12A  is a screen for selecting the year. The artist list screen shown in  FIG. 12B  is a screen displaying an alphabetical list of artists having tracks released in the year selected on the year of release selection screen of  FIG. 12A . The music list screen shown in  FIG. 12C  is a screen displaying a list of tracks released by the artist selected on the artist list screen shown in  FIG. 12B  in the year selected in  FIG. 12A . When a year is selected on the year of release selection screen shown in  FIG. 12A , the CPU  14  displays a list of artists releasing tracks in that year, that is, the artist list screen shown in  FIG. 12B , on the LCD panel  13 . When an artist is selected on the artist list screen shown in  FIG. 12B , the CPU  14  displays the music list screen shown in  FIG. 12C  on the LCD panel  13 . When a track is selected on the music list screen shown in  FIG. 12C , the playback screen of  FIG. 14A  is displayed, the CPU  14  decodes the selected track and sends it to the portable audio player  12 , and the portable audio player  12  plays and outputs the same from the headphone terminal  11 .  
         [0074]     When the new tracks button is selected on the music library screen shown in  FIG. 6 , the CPU  14  displays a list of the recently added albums, that is, the album list screen shown in  FIG. 13A , on the LCD panel  13 .  FIG. 13A  and  FIG. 13B  are views showing the transition of the screen when selecting from among albums or tracks recently added to the HDD  18 . The album list screen shown in  FIG. 13A  is a screen displaying an alphabetical list of albums recently added to the HDD  18 . The track list screen shown in  FIG. 9B  is a screen displaying an alphabetical list of the tracks recorded in the album selected on the album list screen of  FIG. 13B . When an album is selected on the album list screen shown in  FIG. 13A , the CPU  14  displays the track list screen shown in  FIG. 13B  on the LCD panel  13 . When a track is selected on the track list screen shown in  FIG. 13B , the playback screen of  FIG. 14A  is displayed, the CPU  14  decodes the selected track and sends it to the portable audio player  12 , and the portable audio player  12  plays and outputs the same from the headphone terminal  11 .  
         [0075]     The operation screen displayed on the LCD panel  13  therefore changes as explained above. The screens change on the basis of input by the ENTER key  27   e  or the touch panel as mentioned above, but this operation is a reversible operation. It is possible to return to the screen immediately before the present screen by input by the BACK key  28 .  
         [0076]     Note that, as explained above, the screens display various lists, for example, the artist list, album list, track list, and music list. As these lists, when transferring for example track data from the personal computer  3  to the HDD  18  via the USB interface  19 , a list previously prepared on the personal computer  3  may be simultaneously transferred and stored in the HDD  18  and called up from the HDD  18  and used when necessary, or the CPU  14  may prepare a list and display it based on the attribute data of each track data when the list becomes necessary.  
         [0077]     Next, the playback screen will be explained.  FIGS. 14A  to  14 F are views showing the playback screen and the transition of the screen according to an operation of the user.  
         [0078]      FIG. 14A  shows the initial screen during playback of a certain track. As shown in  FIG. 14A , the playback screen displays the different attribute data of the track being played back. “Track_X” in  FIG. 14A  indicates the name of the track being played back, “E****_ 3 ” indicates the album name, “H****_ 15 ” indicates the artist name, “Rock” indicates the genre name, “★★★” indicates the rating, and “2004” indicates the year of release. Note that the attribute data displayed in  FIGS. 14A  to  14 F is an example. In the portable audio player  1  of the present invention, when any of the cross keys  27   a  to  27   d  is depressed in the state shown in  FIG. 14A , the cursor appears at a position of “E****_ 3 ” indicating the album name as shown in  FIG. 14B , and selection by the ENTER key  27   e  becomes possible. Here, as shown in  FIG. 4  and  FIGS. 14A  to  14 F, the cursor moves up and down along the attribute data of the playback screen by depression of the top/bottom keys  27   a  and  27   c,  whereupon selection by the ENTER key  27   e  becomes possible.  
         [0079]     Here, for example, when the ENTER key  27   e  is depressed in  FIG. 14B , that is, in a state where the cursor is placed over the album name of the track being played back at present, as shown in  FIG. 4 , the CPU  14  switches the display of the LCD panel  13  to the track list screen for that album shown in  FIG. 8B . In the same way, when the ENTER key  27   e  is depressed in  FIG. 14C , that is, in the state where the cursor is placed over the artist name of the track being played back, as shown in  FIG. 4 , the CPU  14  switches the display of the LCD panel  13  to the album list screen for that artist shown in  FIG. 9B .  
         [0080]     In the same way, when the ENTER key  27   e  is depressed in  FIG. 14D , that is, in the state where the cursor is placed over the genre name of the track being played back, as shown in  FIG. 4 , the CPU  14  switches the display of the LCD panel  13  to the artist list screen for that genre shown in  FIG. 10B . In the same way, when the ENTER key  27   e  is depressed in  FIG. 14E , that is, in the state where the cursor is placed over the rating of the track being played back, as shown in  FIG. 4 , the CPU  14  switches the display of the LCD panel  13  to the rating screen shown in  FIG. 11 A .  
         [0081]     In the same way, when the ENTER key  27   e  is depressed in  FIG. 14F , that is, in the state where the cursor is placed over the year of release of the track being played back, as shown in  FIG. 4 , the CPU  14  switches the display of the LCD panel  13  to the artist list screen for tracks released in that year shown in  FIG. 12B .  
         [0082]     Namely, according to the portable audio player  1  of the present embodiment, regardless of the list screens going back until the track to be played is determined, the display of the LCD panel  13  is immediately switched to the list screen relating to the attribute of the attribute data selected on the playback screen. That is, for example, even in the case where the track to be played is determined through the menu screen of  FIG. 5 , the artist list screen of  FIG. 9A , the album list screen of  FIG. 9B , and the track list screen of  FIG. 9C , when the rating is selected by the cursor on the playback screen of that track as in  FIG. 14E , the display of the LCD panel  13  is immediately switched to the rating screen of  FIG. 11A .  
         [0083]     As another embodiment, when an album name is selected by the cursor on the playback screen as in  FIG. 14B , control for switching the playback screen to the album list screen of  FIG. 8A  can be considered. That is, the screen is switched to a list including the item selected on the playback screen. In the same way, when an artist name is selected, the display content is switched from  FIG. 14C  to  FIG. 9A , while when a genre is selected, switching of the display content from  FIG. 14D  to  FIG. 10A  may be considered.  
         [0084]     Further, in the playback screens of  FIGS. 14A  to  14 D, where the number of letters of the attribute data over which the cursor is placed is larger than a predetermined number and the letters cannot all be displayed on the screen, the letters of that attribute data are displayed by scrolling. Specifically, for example as shown in  FIG. 1  SA, when displaying attribute data having a number of letters too large to be displayed on the playback screen, for example the track name “Track_abcdefghijklmnopqrstu”, album name “Album_abcdefghijklmnopqrstu”, and artist name “Artist_abcdefghijklmnopqrstu”, first, as shown in  FIG. 15B , the letters within the displayable range are displayed from the first letter of the attribute data.  
         [0085]     Next, in order to display the letters of the attribute data over which the cursor is placed within the nondisplayable range in  FIG. 15A , scroll display is carried out. Namely, for example, as shown in  FIG. 15C , the processing of displaying a portion “mnopqrstu” of the attribute data over which the cursor is placed, i.e., the album name “Album_abcdefghijklmnopqrstu”, which was not displayed in  FIG. 15B , one letter by one letter along with the elapse of time, and deleting the displayed portion “Album_abcdefghijkl” one letter by one letter from the first letter and shifting the remaining letters leftward one letter by one letter is carried out. In  FIG. 15C , the letters which newly appear by scrolling are underlined.  
         [0086]     Further, when the attribute data over which the cursor is placed changes, as shown in  FIG. 15D , the scroll display of the attribute data over which the cursor had been placed is stopped, and the scroll display of the attribute data over which the cursor is newly placed is started. In  FIG. 15D  as well, the letters which newly appear by scrolling are underlined.  
         [0087]     Note that when the number of letters of the attribute data over which the cursor is placed is not more than the predetermined number and can be displayed on the playback screen, the scroll display is not carried out as in  FIG. 15E . Of course, in this case, even if there is other attribute data having a number of letters larger than the predetermined number on the playback screen, the scroll display is not carried out so far as the cursor is not placed over it.  
         [0088]     A concrete example of the scroll display is shown in  FIG. 16 . As shown in (a) to (d), in the scroll display, the letters on the left end of the screen disappear one by one while the letters which could not be displayed appear one by one on the right end along with the elapse of time. Further, when time further passes and the end of the attribute data is scrolled to, letters may be prevented from appearing from the right end again until all letters disappear once from the left end as shown in  FIG. 16D  or scroll display may be again carried out from the first letter of the attribute data with exactly a predetermined number of spaces from the last letter of the attribute data as shown in  FIG. 16E .  
         [0089]     Next, an example of operation of the portable audio player  1  will be explained.  FIG. 17  is a flow chart showing an example of operation of the portable audio player  1 .  
         [0000]     Step ST 1   
         [0090]     The CPU  14  displays a predetermined list on the LCD panel  13 . The predetermined list is for example the music library screen shown in  FIG. 6 .  
         [0000]     Step ST 2   
         [0091]     The CPU  14  judges whether an item on the list displayed at step ST 1 , for example, an artist, was selected. It proceeds to step ST 3  when it was, while re-does step ST 2  when it was not.  
         [0000]     Step ST 3   
         [0092]     The CPU  14  displays the list of the item selected at step ST 2  on the LCD panel  13 . For example, when an artist is selected, the artist selection screen shown in  FIG. 9A  is displayed.  
         [0000]     Step ST 4   
         [0093]     The CPU  14  judges whether there is a command to play the content selected on the list displayed at step ST 3 . When there is no play command, the routine returns to step ST 2 , while when there is a play command, the routine proceeds to step ST 5 . Note that, specifically, the play command is given by selecting a track by for example the all songs selection screen of  FIG. 7 , the track list screens of  FIG. 8B ,  FIG. 9C ,  FIG. 10D ,  FIG. 11B , and  FIG. 13B , and the music selection screen of  FIG. 12C  and depressing the ENTER key  27   e.    
         [0000]     Step ST 5   
         [0094]     The CPU  14  plays the track for which the play command was issued at step ST 4 . Specifically, for example, it plays the track for which the play command was issued on the track list screen of  FIG. 9C .  
         [0000]     Step ST 6   
         [0095]     The CPU  14  displays the attribute data of the content started to be played at step ST 5  on the LCD panel  13 . Namely, for example, as in  FIG. 14A , the track name, album name, artist name, genre name, rating, year of release, etc. of the track started to be played are displayed.  
         [0000]     Step ST 7   
         [0096]     The CPU  14  proceeds to step ST 8  when there is an operation for displaying the cursor on the playback screen displayed on the LCD panel  13  (input by up key  27   a  or down key  27   c ) at step ST 6 , while returns to step ST 6  and waits for input when there was no operation.  
         [0000]     Step ST 8   
         [0097]     The CPU  14  judges whether or not the number of letters of the attribute data over which the cursor was placed at step ST 7  is larger than a predetermined number (number of letters which can be displayed on the playback screen), proceeds to step ST 9  when the number of letters is larger, while proceeds to step ST 10  when not.  
         [0000]     Step ST 9   
         [0098]     The CPU  14  displays the attribute data by scrolling.  
         [0000]     Step ST 10   
         [0099]     The CPU  14  returns to step ST 8  when there was an operation for moving the cursor (input of the up key  27   a  or the down key  27   c ), while proceeds to step ST 11  where there was no operation.  
         [0000]     Step ST 11   
         [0100]     The CPU  14  judges whether the attribute data over which the cursor is placed at present was selected by operation by the input device  15  or the touch panel on the playback screen, proceeds to step ST 12  when the attribute data was selected, while proceeds to step ST 13  when it was not.  
         [0000]     Step ST 12   
         [0101]     The CPU  14  displays a list corresponding to the attribute data selected at step ST 11  on the LCD panel  13 . Namely, as shown in  FIG. 4 , on the LCD panel  13 , the CPU  14  displays the track list of the album shown in  FIG. 8B  when the album name of the track being played back shown in  FIG. 14B  is selected, displays the album list of the artist shown in  FIG. 9B  when the artist name shown in  FIG. 14C  is selected, displays the artist list of the genre shown in  FIG. 10B  when the genre shown in  FIG. 14D  is selected, displays the rating selection screen shown in  FIG. 11A  when the rating shown in  FIG. 14E  is selected, and displays the artist list of tracks released in the year shown in  FIG. 12B  when the year of release shown in  FIG. 14F  is selected.  
         [0102]     Note that the CPU  14  continues to play back the track being played even after switching the screen until a play command of the next track is given.  
         [0000]     Step ST 13   
         [0103]     The CPU  14  judges whether or not the playback of the track being played ends, returns to step ST 11  when it does not, while proceeds to step ST 14  when it does.  
         [0000]     Step ST 14   
         [0104]     The CPU  14  plays the next track of the list including the track finished being played at step ST 13  irrespective of the screen displayed on the LCD panel  13 , then returns to step ST 6 . The list to which the track belongs is for example the track list shown in  FIG. 8B  when the cursor is advanced from the music library screen shown in  FIG. 6  to the album list screen shown in  FIG. 8A  and the track list screen shown in  FIG. 8B  in this sequence and the present track is selected. Namely, it means any list among the screens shown in  FIG. 7 ,  FIG. 8B ,  FIG. 9C ,  FIG. 10D ,  FIG. 11B ,  FIG. 12C , and  FIG. 13B  displayed for reaching the track finished being played. Namely, for example, the artist list screen is displayed on the LCD panel  13  at present. Even in the selection waiting state, irrespective of that screen, the CPU  14  starts to play the next track of the list to which the above track belongs.  
         [0105]     Note that, in the above example of operation, the explanation was given of the case where the lists were followed as shown in  FIG. 4  from the music library screen shown in  FIG. 6 , but the portable audio player  1  of the present embodiment may play back tracks according to a play list etc. previously prepared and stored in the HDD  18 . In this case, the “next track of the list” played back at step ST 14  becomes the next track of that play list. This play list may be prepared on the portable audio player  1  or a list prepared on a PC may be stored in the HDD  18  as it is when transferring the tracks from the PC.  
         [0106]     As explained above, when the user wants to play a track related to a truck currently being played, according to the portable audio player  1  of the present embodiment, it is possible to select the attribute data displayed during playback of the current track embodiment display a list corresponding to that attribute, therefore it is possible to display a list of the tracks desired by a simple operation and in a relatively short time in comparison with the conventional case. Further, according to the portable audio player  1  of the present embodiment, regardless of the list screens followed until the track to be played is determined, the display of the LCD panel  13  is immediately switched to the list screen concerning the attribute of the attribute data selected on the playback screen, therefore the screen display of the LCD panel  13  can be switched to the desired list screen without forcing troublesome operation on the user.  
         [0107]     Note that, in the present embodiment, various keys included in the input device  15  and the touch panel of the LCD panel  13  provided on the case of the portable audio player  1  were exemplified as the inputting means of the present invention, and the LCD panel  13  was exemplified as the display, but for example, an input device  41  including various buttons disposed on the case of a remote controller  4  shown in  FIG. 18  may be used as the inputting means, and an LCD panel  42  may be used as the display.  FIG. 18  is a diagram showing an example of the front surface of the case of the remote controller  4 .  
         [0108]     As shown in  FIG. 18 , the remote controller  4  has the input device  41 , an LCD panel  42 , a cable  43 , and a headphone terminal  44 . The input device  41  is containing various keys disposed on the front surface, side surfaces, and the back surface of the remote controller  41  and receives input by operation of the user in the same way as the input device  15  of the portable audio player  1 .  
         [0109]     The LCD panel  42  performs for example the same display as that of the LCD panel  13  of the portable audio player  1  via the cable  43  mentioned later by the CPU  14  of the portable audio player  1 . The cable  43  is a bi-directional (two way) communication device connected with for example the headphone terminal  11  of the portable audio player  1 , transferring the input by the operation of the user received by the input device  41  to the CPU  14  of the portable audio player  1 , transferring the signal issued by the CPU  14  of the portable audio player  1  for displaying the screen on the LCD panel  42  to the remote controller  4  side, or transferring the audio signal of the track played back by the audio reproduction unit  12  of the portable audio player  1  to the headphone terminal  44  on the remote controller  4  side.  
         [0110]     The headphone terminal  44  connects a headphone or other output device and outputs the audio signal of the track played by the audio reproduction unit  12  of the portable audio player  1  transferred via the cable  43  to the output apparatus.  
         [0111]     The present invention is not limited to the above embodiments. Namely, those skilled in the art can perform a variety of modifications, combinations, sub-combinations, and substitutions concerning the components of the embodiments mentioned above within the technical range of the present invention or equivalent range to that.  
         [0112]     In the above embodiments according to the present invention, an LCD panel  13  was used as the display, but as the display device, use may also be made of for example an organic EL (electroluminescence) panel.  
         [0113]     Note that, in the above embodiments according to the present invention, the data was communicated via the personal computer  3  and the USB interface  19 , but the present invention is not limited to this. For example, the data can be communicated via the server etc. distributing the track data and wireless communications such as infrared communication and a wireless LAN.  
         [0114]     Further, in the above embodiments according to the present invention, the track data was explained as an example of the content data, but the present invention is not limited to this. The content data may be for example movies, still images, and text data. Further, the information displayed on the playback screen may include, other than that explained in the above embodiments, the title, main cast, director, genre, country, year of release, production company, distribution company, and so on in for example the case where the content data is moving picture data such as a movie. Further, when the content data is still image data such as photos, the information may include the date taken, size, type of photo (scene, picture etc.), and photographer. Further, when the content data is text data such as with electronic publishing, the information may include the title, author, genre, publishing company, and so on.  
         [0115]     Further, in the above embodiments, the track data, that is, the content data, was stored in the HDD  18 , but the present invention is not limited to this. Namely, the content data may also be stored in a flash memory etc.  
         [0116]     Further, the above embodiments were explained with reference to a portable audio player as an example, but the present invention is not limited to this. It may be any reproduction device storing content data, performing playback, and having a display function. For example, it may be an HDD recorder, electronic book terminal, DVD player, digital camera, or personal computer.