METHOD FOR REGULATING OF ALIGHT BEAM PROJECTED ONTO A ROTATING DATA CARRIER FOR NOMINAL VALUE DURING READING DATA AND ARRANGEMENT FOR REALIZATION SAID METHOD

摘要

The present invention relates to a method for adjusting the light beam (L) directed to a data carrier (CD) to a nominal value when reading data on a rotating data carrier (CD), which light beam (L) is reflected from the data carrier (CD) to a photodetector whose output signal is the data signal (HF). L) by measuring the tangential angle and the radial angle, a control signal (UR, UT) is generated, the data signal (HF) is demodulated in an amplitude demodulator (DM), a control signal (UR, UT) is generated from the amplitude and phase position of the ademodulated data signal (M). The arrangement according to the invention according to the invention has an objective lens (O) focusing the light beam (L) of an optical scanner (AV) on the data carrier (CD), the data signal of the optical scanner (AV) being passed to an amplifier (V), the output of which is a data processor connected to the input of an amplitude demodulator (DM), the output of the amplitude demodulator (DM) is connected to the first input (E1) of a single control unit (MP) and the input of a first pulse former (I1), the output of the first pulse former (I1) to the second control unit (MP) connected to the input (E2), the measured value (IF) of the focus control circuit from the optical scanner (AV) is routed to a focus controller (FR) generating the focus error signal (FE), the focus error signal (FE) to the optical scanner (AV) and a low pass (TP) whose output is connected to the input of a second pulse former (I2), the output of the second pulse former (I2) is connected to the third input (E3) of the control unit (MP), the first output (A1) of the control unit (MP) emitting a first control signal (UR) and the second output (A2) of the control unit (MP) emitting a second control signal (UT) connected to a device (AV). ŕ