Abstract: An adaptor for setting a disc which is of a smaller diameter than a standard type disc, such as an 8-cm Compact Disc, in a disc playback device such as a standard type Compact Disc player is detachably mounted in a disc housing space of a disc cartridge case, which disc housing space receives a disc in such a manner that it can be replaced and played back therein. The adaptor includes a central opening for receiving a disc of a small diameter therein in such a manner that this disc is roughly positioned and held in the central portion of the disc housing space so as to enable this disc to be set on a turntable of the disc playback device when the adaptor is mounted in the disc housing space of the disc cartridge case. The adaptor also includes a self positioning device for positioning the adaptor with respect to the disc cartridge case so that the adaptor will be held in a position in which the adaptor is not in contact with the disc when the disc is set on the turntable.

Abstract: The disc playback device is capable of playing back a disc such as a Compact Disc housed in its disc case without handling the disc with hands.

Abstract: In a disc playback device in which a disc cartridge case housing a disc is loaded in a disc cartridge case holder of a main body of the device and this holder is moved from a disc non-playback position to a disc playback position for playing back of the disc, a loading system for a disc cartridge case comprises a curved surface portion formed in a corner portion on the side of the disc cartridge case from which the case is inserted into the holder and an uncurved surface portion formed in a corner portion on the side opposite to the side from which the case is inserted into the holder. A case erroneous insertion blocking member having an engaging portion is provided on the holder. If the case in its correct insertion posture is inserted into the holder, the engaging portion of the blocking member cooperates with the curved surface portion of the case to permit the case to be inserted into the holder.

Abstract: In a disc playback device of a type in which a disc or a disc cartridge case housing a disc is loaded in a holder and the disc is played back upon moving of this holder from a disc loading position to a disc playback position, magnetic attraction generating means is provided for attracting the holder and a chassis carrying a turntable to each other. The magnetic attraction generating means may be constructed by securing a magnet to either the chassis or the holder and forming the other with magnetic substance, or may be constructed by securing magnets to both the chassis and the holder. The holder is securely clamped in position when it has been moved to the disc playback position and anti-vibration characteristics of the holder are thereby improved.

Abstract: A disc loading device in a disc playback device comprises a turntable for rotating a disc thereon, a holder which is provided above this turntable for holding a disc or a case housing a disc and is capable of moving upwardly or downwardly with respect to the turntable and a carrier which is capable of moving horizontally with respect to the holder for loading the disc or the case into the holder or ejecting it from the holder. A cam is provided in the holder which cooperates with a hole formed in the carrier to move the holder upwardly or downwardly in loading and ejection of the disc or the case. A clamper may be provided on the holder for fixing the disc to the turntable.

Abstract: In a disc playback device of a type in which a turntable is connected to a disc motor shaft, a device for preventing vibration of the disc motor shaft comprises magnetic biasing means for generating a magnetic force biasing the disc motor shaft in an axial or radial direction of the shaft. The magnetic biasing means is constructed by securing one of magnetic substance and a magnet to the turntable and disposing the other below the turntable or securing one of two magnets to the turntable and disposing the other magnet below the turntable. For preventing vibration of the disc motor shaft in the radial direction, a yoke plate is fixed to the magnet in such a manner that a part of the yoke plate is positioned on the lateral side of the magnetic substance or the other magnet.

Abstract: In a disc playback device of a type in which a turntable is connected to a disc motor shaft, a disc centering device comprises at least three disc centering members provided in the turntable substantially concentrically with the disc motor shaft and separately moveably in the radial direction of the turntable, the centering members being capable of engaging a central opening of a disc, and urging means provided in the turntable for urging the centering members radially outwardly of the turntable. The centering members engaged in the central opening of the disc work in association with the urging means to position the disc concentrically with the disc motor shaft.

Abstract: A mode switching device in a disc playback device comprises a loading device for transferring a disc or a case housing a disc between an eject position in which the disc or the disc case is inserted and ejected and a playback position in which the disc is played, a feed device for feeding a pickup head reading data recorded on the disc set in a playback position and a mode switching device for switching the mode between loading, eject and playback modes. The feed device can move across an overstroke region extending radially outwardly of a read-out position of the pickup head and the mode switching device performs switching of the mode when the feed device has reached a predetermined position in the overstroke region.

Abstract: A disc playback device comprises a loading device for transferring a disc or a case housing a disc between an eject position in which the disc or the disc case is inserted and ejected and a playback position in which the disc can be played, thereby performing loading and eject modes, a feed device for feeding a pickup head which reads data recorded on the disc in a playback mode in a radial direction of the disc set in the playback position, and a single drive source for driving both the loading device and feed device. The single drive source drives the feed device and the loading device is driven through the feed device. A carrier having a carrier rack moved by the drive source and a carrier pinion meshing with the carrier rack are provided in a drive system for a loading pinion meshing with a disc case rack and the loading pinion is connected to the carrier pinion through clutch means.

Abstract: A shutter plate control device in a disc playback device energizes a shutter plate in a disc magazine case with opening and closing members provided in a main body of the disc playback device. The opening member engages with a shutter lever provided on the shutter plate in loading of the disc magazine case to move the shutter plate in a direction for opening an aperture formed in the disc magazine case for exposing the disc to a pickup head to enable the pickup head to read date recorded on the disc. The closing member engages with the shutter lever in loading of the disc magazine case to be displaced by the shutter lever and thereby permit the shutter lever to pass by without moving the shutter plate while it engages with the shutter lever in ejecting of the disc magazine case to move the shutter plate in a direction for closing the aperture.