procedure for the rules of the focus and the leadership of a light path

摘要

A method is proposed which serves to control the focusing of a light beam, aimed at a rotating recording medium (25) for reading data, of a scanner (15, 20) onto the recording medium (25) and the guidance of the light beam along the data tracks of the recording medium (25), each by means of a respective control circuit. The scanner (15, 20) and the recording medium (25) are mounted on a fundamental substrate (10) in at least one housing (1), and the at least one housing (1), together with the fundamental substrate (10), the scanner (15, 20) and the recording medium (25), forms a coupled mechanical oscillator, which is vibrated as a function of a vibration spectrum (75); the scanner (15, 20) is accelerated by the vibration and a relative motion of the recording medium (25) with respect to the scanner (15, 20) is effected, and the amplitudes of the relative motion and the accelerations have a frequency response. The masses, spring constants and damping values of the scanner (15, 20), the recording medium (25), the fundamental substrate (10), and the at least one housing (1) are selected such that the frequencies at which the amplitudes of the relative motion of the recording medium (25) relative to the scanner (15, 20) and the accelerations acting on the scanner (15, 20) are maximal are located in a frequency band of the respective control circuit in which an amplification is performed, and the maximum values of the amplitudes in that frequency band do not exceed a predetermined value.