| 摘要 |
<p>This invention relates to the detection in digital form of position error signals (PES) by employing a digital integrator (36) which comprises a register (48) and adder (46). A composite servo data is amplified by variable gain amplifier (22) and then undergoes low pass filtering (26) before being digitized by an analog to digital converter (ADC) (34). The digital integration is performed by accumulating a constant number of ADC samples in the register (48). Before being accumulated in the register (48), the sampled servo data is alternately multiplied by plus one or minus one for synchronous rectification, using an exclusive-OR gate (44) cascade interposed between the ADC output and adder input. Upon completion of accumulation of a prescribed number of ADC samples, the contents of the register (48) are transferred to a temporary buffer (30) pending interrogation by a servo controlled digital signal processor (DSP).</p> |
