Patent ID: 7345964

Claim:
A tracking error signal generator comprising: four signal processing ports for respectively providing a first analog detection signal, a second analog detection signal, a third analog detection signal, and a fourth analog detection signal; four high-pass filters for filtering out low-frequency noise from the first analog detection signal, the second analog detection signal, the third analog detection signal, and the fourth analog detection signal; four digitizers respectively electrically connected to the four signal processing ports for respectively transforming the first, the second, the third, and the fourth analog detection signals into a first digital detection signal, a second digital detection signal, a third digital detection signal, and a fourth digital detection signal; two relays for respectively delaying and then digitizing the first analog detection signal and the third analog detection signal to obtain a first digital delay detection signal and a third digital delay detection signal; and four comparators for respectively comparing the first digital delay detection signal with the first digital detection signal to generate a first digital comparing signal, comparing the first digital delay detection signal with the second digital detection signal to generate a second digital comparing signal, comparing the third digital delay detection signal with the third digital detection signal to generate a third digital comparing signal, and comparing the third digital delay detection signal with the fourth digital detection signal to generate a fourth digital comparing signal.