Detecting device for tracing error

• Main Author: HIRATSUKA, TAKASHIGE
• Format: Patent
• Language: English
• Published: 21.12.2006
• Subjects: INFORMATION STORAGE; INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER; PHYSICS

This invention relates to a detecting device for tracking error to reduce the influence of error detecting during the detecting of the phase error, and improve the accuracy of tracking error signal. This invention comprises an error detecting device which has: a zero-crossing point for detecting the two series of digital signals generated and outputted from a light detecting means in response to the light-acceptance amount absorbed by each acceptance element, and detects the digital signal and the zero-crossing point of an intersection point of the central voltage level of the digital signal; a phase difference detecting circuit, for comparison of the phases by the distance between the zero-crossing points of the two series of digital signals; and a low-pass filter, for limiting the frequency band of the output signal of the said phase difference detecting circuit to obtain a tracking error signal. When the phase difference of the two series of the digital signals detected by the said phase difference detecting circuit is bigger than the maximum tracking error signal in theory, the outputs outputted by the phase difference detecting circuit will be limited.