Abstract: A disc drive for use with a disc-shaped recording medium, includes a disc driving mechanism for driving the recording medium mounted on a disc mounting surface thereof and a clamping mechanism for clamping the recording medium on the disc mounting surface of the disc drive mechanism. A further driving mechanism is provided for moving the clamping mechanism into a clamping position in which it clamps the recording medium on the disc mounting surface and maintains the clamping mechanism in the clamping position. A motor drives the further driving mechanism. A manually operated mechanism releases transmission between the further driving mechanism and the motor, and manually operates the further driving mechanism to eject the recording medium out of the disc drive.

Abstract: A disc driver comprises a locking plate for locking an operation button depending upon the presence or absence of an inserted magnetic disc, and a spring bridged between a tabular leg portion of the operation button and a slide lever for absorbing a shock given to the operation button locked by the locking plate and disallowing the shock to transmit to the locking plate. In place of the locking plate, a change-over lever can be employed for enabling or disabling a function of the operation button depending or the presence of absence of an inserted disc into the disc driver.

Abstract: A magnetic disc unit comprising motor means having a spindle rotatably mounted on a base for rotating a magnetic recording medium, a loading arm having one end swingably attached to the base and a center cone rotatably attached to the other end of the loading arm. The magnetic recording medium is interposed between the spindle and the center cone. A button lever having a control button projecting from one end is attached to the base and is movable with respect thereto. A clamping lever is also mounted to the base and linkage means interlocks the control button and the clamping lever. Depression of the control button translates the button lever so as to rotate the clamping lever to a first position in which the center cone engages the spindle with the magnetic recording medium interposed therebetween.

Abstract: A head position control device capable of controlling the position of mutually cooperating plural heads with a circuit provided in a drive thereby reducing the burden of the attached system and enabling independent seeking operations of the heads on a magnetic disk. The head position control device of the present invention performs track seeking operation within a minimum time regardless of the access time of the attached system thereby reducing the head switching time, and also allows reduction in the dimension and weight of the entire system.