OPTICAL READER (DESIGN VERSIONS) Russian patent published in 1999 - IPC

FIELD: computer engineering. SUBSTANCE: reader has light source, beam splitter, lens for focusing light beam on disk, numerical aperture control, and photodetector. Numerical aperture control is made for controlling effective value of lens numerical aperture to focus beam on disks of different thickness. Second design version has, in addition, newly introduced repetition rate control unit, focus control unit, reproducing signal processing device, disk identifier, numerical aperture control drive, spindle motor, motor control unit, and microcomputer. Third design version incorporating mechanical system with motor and optical system with light source, photodetector, lens for focusing light on disk, and numerical aperture control has its optical system provided with prism and its light source and photodetector made in the form of assembly, and numerical aperture control made for controlling numerical aperture of lens to focus beam on disks of different thickness; its mechanical system motor is movable member built integral with optical system. EFFECT: provision for reading data off disks of different thickness. 51 cl, 39 dwg, 2 tbl