Abstract: An optical unit includes a first holder with a radiation source, a second holder with a radiation-sensitive detector, a grating, and a mirror. The unit further includes a cylindrical mounting having a cylinder axis and a wall oriented transversely to the cylinder axis, the grating and the mirror being formed by optically transparent wall portions of the wall. The mounting has a first positioning surface to which the first holder with the radiation source is secured and a second positioning surface to which the second holder with the radiation-sensitive detector is secured.

Abstract: An apparatus having a frame (1) carrying a turntable (3) for supporting the information carrier, which turntable is rotatable about an axis of rotation (3A), a slide (9), which is movable between two end positions, with a scanning unit, guide spindles (5, 7) and a linear motor unit (17, 19) for the slide, and an electrically energizable clamping unit (21). In the non-energized condition the clamping unit clamps the slide in any arbitrary stationary position of the slide along its path and in the energized condition it does not clamp the slide. During operation of the device a control unit at least substantially simultaneously turns on a first energizing current to the motor drive unit and a second energizing current to the clamping unit at the beginning of a displacement of the slide and at least substantially simultaneously turns off the first energizing current and the second energizing current at the end of the displacement.

Abstract: In order to pivot a pivotal arm (60) carrying an optical scanner (5), use is made of at least one coil (13) and at least one permanent magnet (16, 17), the coil being arranged on the pivotal arm or on a frame supporting the arm and the permanent magnet being arranged on the frame or on the arm. The coil (13) has a substantially straight active coil section (14) which is arranged near the pivotal axis (8) about which the pivotal arm is pivotable and which extends transversely of the longitudinal axis of the pivotal arm. The ends of this coil section are interconnected by a further coil section (15) which is, for example, concentric with the pivotal spindle and which extends at that side of the pivotal axis which is remote from the scanning unit.