Abstract: The light pressure rotator (1) is the light pressure rotator being light pressure trapped by irradiation with light and light pressure rotating about the central axis O of rotation, characterized in that a reverse torque generating section generating a torque for rotating the rotator in the direction reverse to the predetermined direction is removed from a section arranged with three blades (2) each having a first side face (3) extending in the radial direction from the central axis O of rotation, a second side face (4) facing the central axis O of rotation, a third side face (5) facing the first side face (3), a lower surface (6) intersecting the central axis O of the rotation, and an upper surface (7) facing the lower surface (6). The light pressure rotating device comprises the light pressure rotator (1), a light source (C), and an objective (condenser) lens D.

Abstract: The light pressure rotator (1) is the light pressure rotator being light pressure trapped by irradiation with light and light pressure rotating about the central axis O of rotation, characterized in that a reverse torque generating section generating a torque for rotating the rotator in the direction reverse to the predetermined direction is removed from a section arranged with three blades (2) each having a first side face (3) extending in the radial direction from the central axis O of rotation, a second side face (4) facing the central axis O of rotation, a third side face (5) facing the first side face (3), a lower surface (6) intersecting the central axis O of the rotation, and an upper surface (7) facing the lower surface (6). The light pressure rotating device comprises the light pressure rotator (1), a light source (C), and an objective (condenser) lens D.

Abstract: A micro optical head, for optically reading and/or writing digital data on a recording medium in which digital data 1 and 0, corresponding to a high reflection factor and a low reflection factor, is composed of a self-coupled semiconductor laser located close to the recording medium. A bias current of the laser is determined so that it is smaller than a first threshold current, in which the medium has a low reflection factor, and is higher than a second threshold current, in which the medium has a high reflection factor. Output light of the laser is either strong stimulated emission light, corresponding to the high reflection factor, or weak spontaneous emission light, corresponding to the low reflection factor. The present head is carried on a flying slider with a spacing length less than several .mu.m which provides a small beam spot of about 1 .mu.m, and has an excellent signal to noise ratio.

Abstract: An optical head for use with an optical disk has a unit packaging an optical path conversion device for converting a light beam path from substantially in parallel to the surface of a rotating optical disk into a direction substantially perpendicular to the surface of the optical disk, a lens system for focusing the light beam onto the recording surface of the optical disk, and a focus controlling mechanism for adjusting the focus of the lens system. A head outer shell supports the unit by one or more diaphragms for movement of the unit in the parallel direction of the optical path. A track control mechanism which includes an electromagnetic actuator adjusts the positional relation of the unit relative to outer shell in that parallel direction without causing unit movement in the perpendicular direction.