Abstract: A head for writing data into and/or reading data out of a recording medium such as a magnetic disc is displaced along a path by a motor such as a voice coil motor. The moving member of the motor is disposed on one side of the path, and another moving member of a speed sensor for detecting the head displacement speed is disposed on the opposite side. As a result, an unbalanced mass arrangement with respect to the path along which the head is displaced will not occur. The signal from the speed sensor can be used, for example, to interrupt a write operation if a mechanical impact occurs. Furthermore, even in an embodiment in which a coil is wound around the moving member of the speed sensor so that the head displacement speed is detected as a voltage induced across the coil as the head is displaced, the motor and the speed sensor are disposed in spaced-apart-relationship with each other and the speed sensor is less susceptible to adverse effects caused by the leakage flux from the motor.

Abstract: A variable compression ratio apparatus is provided for use in an internal combustion engine. The apparatus has an eccentric sleeve rotatably arranged in one of pivot portions at opposite ends of a connecting rod so as to make a bearing hole of the connecting rod and a pin, which extends through the bearing hole, eccentric relative to each other. The apparatus also has an eccentric sleeve lock device capable of fixing rotation of the eccentric sleeve at a desired position. The lock device includes a pin member engageable with one of engagement portions formed in the eccentric sleeve and a piston-type fluid pressure drive system. The drive system is adapted to produce a pressure difference between fluid pressure chambers formed at opposite sides of a piston portion, which is connected to the pin member, in a state that the fluid pressure chambers are applied with a prescribed fluid pressure, whereby the piston portion is moved to drive the pin member.

Abstract: In a disc storage unit capable of writing a servo signal for positioning a recording head at each track defined on a disc-shaped recording medium, data in a region between adjacent tracks are erased prior to the writing of the servo signal. The data stored on the recording medium are completely erased and then the servo signal can be written in the recording medium.

Abstract: This specification discloses a card processing apparatus which is constructed such that a card having information recorded thereon and a paper leaf are superposedly placed on card tray movably disposed in an opening formed within the housing of the apparatus and the following card processing is carried out by pushing the card tray into the interior of the housing: first, the card and the paper leaf are separated from each other and the card alone is transported so that first information recorded on the card is read by reader means, whereafter the card is transported back to the card tray to restore its initial position; next, information extraneously entered is compared with the first information read from the card and only when the two types of information are identical, urge means is operated to urge the superposed card and paper leaf, whereby second information recorded on the card is recorded onto the paper leaf.

Abstract: A planetarium moon projector of the direct casting type includes two alternatively interchangeable occulting elements which rotate at twice the period of moon phasing to intercept the projected light beam and effect the waxing and waning of the moon, and which are conically shaped with the same convergent angle as the projected convergent light and with an occulting relief angle. Two intermittent gears revolve integrally with the occulting elements and there is provided a fixed cylindrical rail with a rack, which keeps contact with the intermittent gears, and which interchanges the occulting elements when the intermittent gears are engaged with the rack. An eccentric drive coupling is provided to correct the dislocation of the moon phase caused by the occulting relief angle.