Abstract: A disc drive may provide data communications to a host using a universal serial bus (“USB”) interface. Activation of the USB interface may be triggered upon insertion of a disc into the disc drive. A connection unit may activate the USB interface by providing power to the USB interface when a disc switch detects that the disc has been inserted into the disc drive. The connection unit may deactivate the USB interface by no longer providing power to the USB interface when the disc switch detects that the disc has been ejected or no longer is in the disc drive.

Abstract: An optical frequency division multiplexing transmission system for sending a large volume of information by a single optical fiber is disclosed. Each of an optical frequency division multiplexing transmitter equipment and an optical frequency division multiplexing receiver equipment has an optical filter having a periodic optical transmission characteristic therein. Each optical filter is stabilized with an absolutely-stabilized standard optical frequency. Each optical signal frequency is stabilized to a periodic transmission characteristic of the optical filter arranged in the optical frequency division multiplexing transmitter equipment, and each local frequency to a periodic transmission characteristic of the optical filter arranged in the optical frequency division multiplexing receiver equipment.

Abstract: A disk playback device includes a magazine for several disks and trays for supporting the disks, a magazine housing for the magazine, a disk playback section for playing back data recorded on a disk and a tray transport section for transporting a tray, supporting a selected disk, between the magazine and the playback section. In one embodiment, the playback device includes a disk guide for securely placing a played back disk onto its associated tray. In another embodiment, the playback device includes a disk guide for guiding disks of various diameters. In another embodiment, the playback device includes an optical detecting element for detecting whether a tray contains a disk. In another embodiment, the playback device includes a switch for detecting whether a magazine has been inserted and locked in the magazine housing. In another embodiment, the playback device includes a guide mechanism for securely guiding a disk clamper to a selected disk for playback.

Abstract: A disc loading structure capable of safely and effectively carrying out a disc loading operation free from mistake. The disc loading structure includes a sensor group consisting of a plurality of disc detecting sensors each selectively exhibiting a detection mode and non-detection mode. The sensor group is arranged so as to permit the disc loading structure to properly accomplish the disc loading operation such as detection and ejection of any foreign article inserted therein, discrimination and loading of each of discs different in size and the like, depending upon a pattern of combination of the detection and/or non-detection modes of the sensors.

Abstract: A disc ejecting structure capable of positively detecting the position of a disc during a disc ejecting operation to eject the disc from a disc player with safety and high reliability. The disc ejecting structure includes a plurality of disc detecting sensors which are so arranged that a disc which is in the course of ejection or at an ejection completing position is detected depending upon patterns of combination of detection and non-detection modes of the sensors.

Abstract: A front-loading type disk player, such as a video or compact disk player, having an improved front loading mechanism which absorbs any play or backlash that occurs during the movement of the carriage so that the carriage is accurately controlled in position as it moves in and out of the housing of the player. Support members for the chassis have a stopper with which the carriage comes into contact when the disk reaches a predetermined playing or recording position. An energizing force is applied during the time an accelerating mechanism drives the carriage in the direction of the accommodation position inside the housing, continuing for a short time after the carriage contacts the stopper. The excess force is absorbed by urging the carriage against the stopper.

Abstract: An electronic timepiece having an A.M. and P.M. display function. The characters A or P are displayed during time setting or correction by one discretionary display element of a plurality of display elements normally used for displaying time.