Abstract: An on-track and off-track state detecting apparatus in a compatible disk player capable of playing different types of disks, each carrying thereon at least one of a FM audio signal and an EFM signal. The apparatus detects an on-track state and off-track state by comparing the level of the FM audio signal component with a predetermined level, when the disk being played back does not carry the EFM signal, and by comparing the level of the EFM signal component with a predetermined level, when the disk being played back carries the EFM signal thereon. This apparatus commonly uses a level comparator circuit and performs a reliable detection of the respective on-track and off-track states.

Abstract: A magazine-housed disk reproducing apparatus is disclosed which enables the user to easily determine the contents of the various disks contained in the magazine. The names of tunes and the like provided on the various available disks are stored in a memory. An identifying device detects which magazines containing which disks have been loaded. A display device is activated to indicate to the user the desired content information.

Abstract: An apparatus for playing a composite disk containing separate audio-only and video-plus-audio portions, as well as an ordinary compact disk. It is first detected whether the disk being played is a compact disk or a composite disk, and if the disk is a composite disk, whether the portion presently being played is a region containing only audio data or a region containing a frequency modulated video signal recorded in multiplex form with a digital signal. A reference signal for driving a spindle servo circuit is produced as a fixed frequency signal when the disk is a composite disk or the region of a composite disk being played contains only audio data, and as a variable frequency signal of frequency determined in accordance with the frame sync signal contained in the reproduced signal when a region of a composite disk containing a multiplex-type signal is being reproduced.

Abstract: A method and device for playing a composite disk containing separate audio-only and video-plus-audio portions in which the time until the commencement of the playing of the video-plus-audio portion is reduced. When playing of only the video-plus-audio portion is designated, a data detection point of the pickup is immediately moved toward the lead-in area of that portion, whereupon reproduction is started immediately. In another embodiment, index data is directly read from the lead-in area of the video-plus-audio portion without reading similar data for the audio-only portion. When the playing of the video-plus-audio portion is completed, the pickup is stopped at a rest position corresponding to the lead-in area of the second region.