embodiments of the disk device according to the present invention will be described with reference to the attached drawings . fig1 is a block circuit diagram showing an embodiment of an electrical construction of the disk device according to the present invention . the disk device according to this embodiment is applied to a dvd recorder and constructed such that information recorded on a dvd 1 is reproduced and is recorded with externally inputted information is recorded on the dvd 1 by operating a push key of a remote controller 22 . incidentally , in this description , a reproducing function of the disk device will be described mainly . in fig1 , a reference numeral 2 depicts a disk tray on which the dvd 1 is mounted . the disk tray 2 is driven by a disk motor 3 . further , a reference numeral 4 depicts a photodetector , which outputs reproducing information optically read out from a track of the dvd 1 to an rf amplifier 5 . the rf amplifier 5 supplies the reproducing information to a dsp ( digital signal processor ) 6 and a servo control unit 7 . an output of a servo control unit 7 is supplied to the dsp 6 . the rf amplifier 5 , the dsp 6 and the servo control unit 7 , etc ., are controlled by a micro computer 9 ( referred to as “ front end micro computer ” hereinafter ) for reproducing the information from the dvd 1 . a track buffer ram 8 is connected to the dsp 6 and temporarily stores data , which is amplified by the rf amplifier 5 and decoded according to dvd standards ( in this embodiment , compressed according to mpeg ( moving picture coding experts group )). further , the dsp 6 is connected to a video encoder 13 and a d / a converter 14 through an a / v ( audio / video ) decoder 12 . the servo control unit 7 controls a focus servo and a tracking servo with respect to the photodetector 4 according to commands and control data transmitted / received from the front end micro computer 9 through the dsp 6 . the servo control unit 7 further controls a sled motor 10 for moving the photodetector 4 in a radial direction of the dvd 1 and a tray motor 11 for driving the disk tray 2 . the a / v decoder 12 is connected to a micro computer ( referred to as “ back end micro computer ”, hereinafter ) 16 for controlling an output operation of various information reproduced by the dvd 1 . the a / v decoder 12 functions to expand the compressed data compressed according to mpeg and read out from the track buffer ram 8 . incidentally , an a / v decoding ram 15 is connected to the a / v decoder 12 and stores data , which corresponds to several screens , among the digital data expanded as mentioned above . the video encoder 13 encodes the video data from the a / v decoder 12 and supplies the encoded video data to a monitor 23 shown in fig3 through an output terminal 13 a . further , a d / a converter 14 converts the audio data from the a / v decoder 12 into an analog signal and supplies the analog signal to a loud speaker ( not shown ) through an output terminal 14 a . incidentally , an output of an osd ( on screen display ) circuit ( not shown ) is supplied to the video encoder 13 . the osd circuit outputs an osd signal to the video encoder 13 on the basis of a display control of the back end micro computer 16 to display various setting items on a screen 23 a of the monitor 23 as menu . the setting items include a setting of genre information in addition to basic setting items such as video image regulation and audio balance , etc ., as shown in fig3 . the setting of the genre information is performed by an operation of a remote controller 22 or a key input unit 20 . incidentally , the osd circuit further performs a display of items such as view restriction , warning and password input related to reproduction in view restriction time as shown in fig4 to fig6 . a reference numeral 16 depicts a back end micro computer connected to a work ram 17 for storing various data . the work ram 17 stores genre information from the remote controller 22 as genre data in predetermined areas thereof . the genre information includes variety , animation , adult , drama , movie and news , etc ., corresponding to kinds preliminarily recorded in the dvd 1 . a front panel controller 18 is connected to the back end micro computer 16 . the front panel controller 18 performs a control of a front panel 19 constructed with an lcd , etc ., and is supplied with an output of a key input unit 20 and an output of a receiving unit 21 , which receives an infrared transmission signal from the remote controller 22 . the remote controller 22 includes function keys in addition to the various operation keys similar to those of a popular dvd recorder . that is , the remote controller 22 includes a menu key for displaying menu on the screen 23 a of the monitor 23 , a cursor key for reproduction function and selection of a menu item and a decision key for setting a selection contents , etc . when the menu key is operated , menu items shown in fig3 are displayed on the screen 23 a of the monitor 23 . when the cursor key is operated , any of the items is selected and , when the decision key is operated , the selected menu item is decided . when genre among the menu items is selected , genres and check boxes are displayed on the screen 23 a as shown in fig4 . when the cursor key is operated , a pointer is moved to any of the check boxes and , when the decision key is operated , the selected check box is checked to selectively decide a particular genre . the remote controller 22 makes an input of the password possible while viewing the screen 23 a of the monitor 23 . further , the remote controller 22 includes a view restriction key though it is not shown . by pushing the view restriction key , an instruction signal indicative of the genre information , view of which is restricted during reproducing of the av information , is generated . the view restriction key may be provided separately or any other function key may be used as the view restriction key concurrently . when any key of the remote controller 22 constructed as mentioned above is pushed , a signal corresponding thereto is transmitted to the dvd player through infrared ray . incidentally , the back - end micro computer 16 is bi - directionally connected to the front - end micro computer 9 in such a way that the operation of the whole disk device is controlled by the micro computers 9 and 16 . that is , upon the instruction signal from the key input unit 20 or the remote controller 22 , the servo control unit 7 performs a control correspondingly to the content of the instruction to record the information in the read - in area , the user data area and the read - out area of the dvd 1 or reproduce information recorded therein . further , when the genre information related to the view restriction is inputted during the reproduction of information , the back - end micro computer 16 compares the genre information with the genre data in the work ram 17 and , when they are coincident , the back - end micro computer 16 performs a control for blocking reproduction of the av information of the same genre . further , it performs a control for storing and registering the password data from the remote controller 22 in the work ram 17 and , when password data is sent during reproduction of information , performs a next operation control by authenticating the registered password . fig2 shows a data recording structure of the dvd 1 . the dvd 1 includes the read - in area , the user data area and the read - out area and audiovisual information ( av information ) of such as movie program is recorded in the user data area . addresses indicating fine points ( positions ) of a spiral recording track of the dvd 1 , which are necessary to write the av information in the user data area as digital data , are preliminarily provided in the dvd 1 . the addresses correspond to a time elapsed from an initial recording position to a last recording position . further , in a toc region of the read - in area , recording positions of chapters and titles are recorded as address data correspondingly to lapse time information from a recording start position ( chapter no . 1 of title no . 1 ). therefore , when the data in the toc region is read out , it is possible to display , on the screen 23 a of the monitor 23 , title number , chapter number of such as a movie , recording start and end positions and a detailed recording time , etc ., which are recorded in the user data area of the recording track . further , a test data is recorded in this read - in area of the disk . the genre information for view restriction can be recorded as a sub code of the text data . the sub code is a control display signal recorded together with the digital data and is composed of 8 channels p , q , r , s , t , u , v and w . the channels p and q are used for control and display in usual reproduction and the text data is recorded in the 6 channels r . s , t , u , v and w . during reproduction of the dvd 1 , the information read out from the read - in area thereof is decoded and then the text data in the 6 channels is converted into 8 - bit character information . therefore , it becomes possible to display the kind information of genre on the screen 23 a of the monitor 23 . incidentally , the text data are put together as a text data pack of 18 bytes and a text data block is constructed with a plurality of the packs , the maximum number of which is 256 . a text group is constructed with a plurality of text data blocks , the maximum number of which is 8 , and recorded in the read - in area repeatedly . therefore , it is possible to record , in each block , the kind of genre information in addition to the kind of language . in this embodiment , the kinds variety , animation , adult , drama and news are recorded as the genre information . incidentally , a data indicating an end of recording of the av information is written in the read - out area . now , an operation of the dvd player will be described with reference to the drawings . here , a case where the dvd 1 recorded with a movie is reproduced will be described . a movie is preliminarily recorded in the user data area of the dvd 1 as the av information . further , the genre information of adlut indicating movie for adult is recorded in the read - in area of the dvd 1 . a user who decides that a content of the movie is not suitable for a child preliminarily sets the view restriction . first , when the user operates the menu key of the remote controller 22 , the back - end micro computer 16 controls the osd circuit according to the menu display instruction signal to display a menu of various setting items of menu on the screen 23 a of the monitor 23 as shown in fig3 . then , when the user selects the view restriction among the various setting items by operating the cursor key and the decision key , the back - end micro computer 16 performs the control for displaying variety , animation , adult , drama and news , etc ., together with the check boxes on the screen 23 a of the monitor 23 as shown in fig4 . when the user checks the check box for adult , adult is decided as the genre , view of which is to be restricted . upon this determination , the back - end micro computer 16 controls to store the genre data of adult in a predetermined area of the work ram 17 . when the dvd 1 is reproduced thereafter , a play key mounted on the tray of the dvd recorder is operated . the back - end micro computer 16 is checking whether or not the disk is mounted ( step s 11 ) and , when the dvd 1 is mounted in the predetermined position and there is the reproduction instruction , starts reading of the information in the recording track ( step s 12 ). first , when the text data in the read - in area is read out , it is sent to the back - end micro computer 16 through the dsp 6 . the back - end micro computer 16 determines , from the input information , whether or not the genre information is recorded in the sub code of the text data ( step s 13 ). when the genre information is not inputted , the reproduction of the av information is started by the servo control portion 7 under control of the front - end micro computer 9 ( step s 19 ). since the genre information is preliminarily recorded in the dvd 1 , the genre information is compared with the genre data in the work ram 17 ( step s 14 ). thereafter , the back - end micro computer 16 determines whether or not the viewing of the genre information is to be restricted ( step s 15 ). since , in this case , the genre data of adult is stored in the work ram 17 , the back - end micro computer 16 decides that these information are coincident . incidentally , when the genre data of adult is not stored in the work ram 17 , the reproduction of the av information is started ( step s 19 ). on the other hand , when the genre information from the dvd 1 is one to be restricted , the back - end micro computer 16 controls the osd circuit to display “ warning ” shown in fig5 on the screen 23 a of the monitor 23 . thus , when a child tries to view the dvd 1 , the child can be notified the view restriction . thereafter , the back - end micro computer 16 displays characters for urging the child to input the password and an input box therefor such as shown in fig6 on the screen 23 a of the monitor 23 ( step s 17 ). when the password is input according to this display , the back - end micro computer 16 compares it with data of the preliminarily registered password to decide whether or not it matches up to the data ( step s 18 ). when the passwords are not coincident , the reproduction of the av information is not started and the series of operations of the disk device is ended . on the other hand , when the password is authenticated , the reproduction of the av information is started ( step s 19 ). then , it is decided whether or not the reproduction is to be ended ( step s 20 ) and the series of operations of the display device is ended at a time when the reproduction is ended . therefore , only the user who knows the password can reproduce the dvd 1 and watch it . a child who does not know the password can not watch the movie due to the view restriction except when he is permitted to watch it by the user . incidentally , when the instruction signal is sent from the view restriction key while reproducing the information of the dvd 1 , the back - end micro computer 16 controls the system to display the kind of genre of the reproduced information on the screen 23 a of the monitor 23 . in such case , after the characters urging a user to input the password are displayed and then the input password is authenticated as shown in fig6 , the kind information of genre displayed is stored in the work ram 17 . therefore , it is possible for the user to restrict the viewing easily by deciding whether or not the program can be watched by the child while watching the reproduced image . incidentally , the disk device of the present invention is not limited to the described embodiments and can be variously modified within the scope of the present invention .