Abstract: A disc drive employing components including a recording disc, a read/write head, a head positioner, and an arm are mounted on a carriage member for recording data on the recording disc and reproducing recorded data from the recording disc. A cover member is secured to the carriage member to define a closed space in which the components are located by means of a resilient sealing member which provides resilient engagement with the carriage member and resilient engagement with the cover member without physically distorting the carriage member.

Abstract: The present invention provides a disc drive apparatus having an improved tracking control and seek time adjustment. The head tracking error distribution along the disc radius is determined with reference to the phases of a plurality of position sensors and is calculated based on the tracking error of a reference track in first and second reference regions with respect to the signal from one of the position sensors. This information is used to determine the tracking error distribution along the disc radius with respect to that one of the position sensors. The tracking error distribution is used to determine the tracking error of a reference track in a third reference region with respect to the signal from the same position sensor. This tracking error is used to determine the tracking error of other reference tracks in the third reference region with respect to the signals from other of the position sensors.

Abstract: A disk recording and/or reproducing apparatus performs recording information on and/or reproducing information from a disk-like recording medium within a sealed receptacle by the use of a head. In the apparatus, an optical encoder for detecting positions of the head with respect to the disk-like recording medium has such a scale plate as to be swingable on the arm shaft of a head arm together with the head arm, as to have scale marks engraved in the radius direction of the arm shaft, and as to consist of a single member in whole, so that a trouble such as the head is off the track due to a thermal influence and so forth, never occurs.

Abstract: A loudspeaker comprises a diaphragm including first and second layers and a core member sandwiched between the layers, in which the core member has an edge or peripheral surface aslant relative to the direction of thickness thereof; and a drive assembly, which includes a voice coil wound around a voice coil bobbin and which is connected to a node portion of the diaphragm when vibrated in its divided vibration mode. A support structure supports the diaphragm and the drive assembly, and includes a frame and an edge member secured to the frame, the edge member having a first portion corresponding to the slant of the edge surface of the diaphragm and which is adhesively connected thereto.