Abstract: A multimagazine disc player includes an array of magazines removably stored therein each for holding a plurality of discs, and a playback device movable and positionable in alignment with one of the magazines at a time for playing back a selected one of the discs contained in the magazine. The discs stored in the magazines can selectively be played back automatically, and can also easily be replaced with other discs not stored in the disc player. The magazines are arrayed horizontally to make the disc player highly stable. The discs are stored in vertically erected positions so that the magazines can be removed and loaded with ease.

Abstract: A multimagazine disc player includes an array of magazines removably stored therein each for holding a plurality of discs, and a playback means movable and positionable in alignment with one of the magazines at a time for playing back a selected one of the discs contained in the magazine. The discs stored in the magazines can selectively be played back automatically, and can also easily be replaced with other discs not stored in the disc player. The multimagazine disc player also has a magazine presence/absence detecting means for detecting whether each magazine is loaded or not, so that a wasteful time which would otherwise be consumed by moving the playback means to a position where no magazine is loaded can be eliminated.

Abstract: A multimagazine disc player includes an array of magazines removably stored therein each for holding a plurality of discs, and a playback device movable and positionable in alignment with one of the magazines at a time for playing back a selected one of the discs contained in the magazine. The discs stored in the magazines can selectively be played back automatically, and can also easily be replaced with other discs not stored in the disc player. The magazines are individually locked in their loaded positions by a plurality of respective locking devices so that the magazines can selectively be loaded and unloaded.

Abstract: A dental material having X-ray contrastability which is excellent in strength, aesthetic appearance, workability, marginal blocking and the like and possesses high value in use can be provided by using a methacrylate having an aromatic hydrocarbon substituted by bromine in the molecule as polymerizable monomer and, as occasion demands, combining a filler and/or hardener suitably selected with this compound.

Abstract: A centering apparatus for a disk having two circular recording substrates joined together with respective center holes which may be misaligned. A first and a second centering member center respectively the two disks and a mechanical actuating rod in a single motion moves the second centering member radially outward into engagement with center hole of the second substrate and presses the first centering member axially out of engagement with the center hole of the first substrate.

Abstract: A disc playing system for playing discs selected from a plurality of stored discs in succession, includes a disc storing part in which a plurality of disc storing slots are provided, a transportation means movable along a direction of arrangement of discs in the disc storing part, for transporting a selected disc from a disc storing slot to a playing position and vice versa, in which the disc storing part is provided is a plurality of guide members for guiding the disc transportation means into each of the disc storing slots, and a swingable member is provided to the transportation means, so that the selected disc is surely picked up from the storing slot and returned thereto. Due to this feature, the spaces between each disc stored in the disc storing part are reduced, and in turn the time required for changing the disc is reduced.

Abstract: An automatic disc loading and exchanging apparatus of a disc reproducing system including a disc drive unit, comprising a disc storage unit for storing a plurality of discs in conjunction with the disc drive means in a manner that the discs are arranged in an array, a disc retainer to have a disc retained in a position to be driven for rotation by the disc drive unit, and a disc transport assembly movable in parallel with the array of the discs independently of the disc retainer and including a disc carrier adapted to carry at least two discs. The disc transport assembly is movable between a first position operative to have a disc transferred between the array of the discs and the disc carrier and a second position operative to have a disc transferred between the disc carrier and the disc retainer. The first position is variable depending upon the disc to be transferred between the array of the discs and the disc carrier, while the second position is fixed with respect to the disc retainer.

Abstract: An automatic disc playing system for playing selected ones of a plurality of discs stored therein in succession, includes a disc storing part for holding the discs, having a plurality of slots juxtaposed in a predetermined direction, a detection means for detecting the presence or absence of a disc in each of the slot, and a memory means for memorizing the number of vacant slots in accordance with the output signal of the detection means. The detection means is made up of a plurality of members provided to each of the slots, to be shifted when a disc is put in the slot, and a sensor means to be moved along the direction of the arrangement of the slots for detecting the position of each of the members provided to the slots.

Abstract: A disc playing system for playing a plurality of discs in succession, having a disc storing part in which a plurality of disc are juxtaposed in a predetermined order, comprises a disc carrying means movable along the direction of the arrangement of the discs in the disc storing part, a transportation means for transporting a disc between the storing position and the disc carrying means, a memorizing means for memorizing an order of arrangement of each disc in the disc storing part, a detection means for detecting a frequency of playing of each disc, and a control means for operating the disc carrying means and transportation means for altering the order of arrangement of discs in the disc storing part in accordance with the detected result of the playing frequency of each disc, whereby the time required for changing the disc during a continuous playing is greatly reduced.