19. A scroll display control method comprising: displaying and reading text information corresponding to a picture in synchronism with reproduction of the picture in a scrolling manner, and performing scroll display of said text information in synchronism with the reproduction of the picture information by changing a scroll speed of a target text adaptable to the picture under reproduction, wherein a display area of said text information is fixed at a display reference position of a text display screen, a scroll speed calculation means which calculates said scroll speed of the target text on the basis of a time length of a picture information section being reproduced, a quantity of the target text belonging to a target text section corresponding to said picture information section, and text display setting information; and a user instruction input means for dynamically changing the text display setting information related to the display reference position of the text display screen and the scroll method comprising a method for starting a scroll after a lapse of a predetermined time from a starting time of the target text, wherein text of a preceding text section which precedes the target text section and text of a succeeding text section which succeeds the target text section are respectively displayed in two adjacent areas across the text section displayed at the display reference position of the text display screen, wherein changing a text display setting of the text to be synchronously displayed with reproduction of the picture, and wherein, when the text display setting of the target text is changed, said scroll speed is derived on the basis of the changed text display setting of the target text, wherein the scroll speed calculation means calculates said scroll speed of the target text on the basis of the display reference position changed by the user instruction input means.
19. A scroll display control method comprising: displaying and reading text information corresponding to a picture in synchronism with reproduction of the picture in a scrolling manner, and performing scroll display of said text information in synchronism with the reproduction of the picture information by changing a scroll speed of a target text adaptable to the picture under reproduction, wherein a display area of said text information is fixed at a display reference position of a text display screen, a scroll speed calculation means which calculates said scroll speed of the target text on the basis of a time length of a picture information section being reproduced, a quantity of the target text belonging to a target text section corresponding to said picture information section, and text display setting information; and a user instruction input means for dynamically changing the text display setting information related to the display reference position of the text display screen and the scroll method comprising a method for starting a scroll after a lapse of a predetermined time from a starting time of the target text, wherein text of a preceding text section which precedes the target text section and text of a succeeding text section which succeeds the target text section are respectively displayed in two adjacent areas across the text section displayed at the display reference position of the text display screen, wherein changing a text display setting of the text to be synchronously displayed with reproduction of the picture, and wherein, when the text display setting of the target text is changed, said scroll speed is derived on the basis of the changed text display setting of the target text, wherein the scroll speed calculation means calculates said scroll speed of the target text on the basis of the display reference position changed by the user instruction input means. 21. The scroll display control method according to claim 19 , wherein when the target text section corresponding to a picture reproduction position is changed, said scroll speed is derived on the basis of a time length of a picture section corresponding to the picture reproduction position and a text quantity of the target text section corresponding to the picture reproduction position.