Patent Number: 6,298,024

Title: Device for identifying optical disc type based on density of radialinformation tracks thereon

Abstract: A controller instructs a spindle motor to start rotating, and instructs aservo control section to start a focus servo control. When a light beamcrosses information tracks on an optical disc with a rotation of theoptical disc, an amplitude indicating signal generating section detectschanges in the amplitude of a readout signal output from an opticalpickup. A disc type identifying section identifies types of optical discshaving different track pitches of the information tracks in starting therotation of each optical disc based on the peak value and bottom value orthe amplitude of the readout signal. Consequently, the types of opticaldiscs having different information recording densities, particularlydifferent track pitches, can be identified at an early stage withoutwaiting for reproduction of information recorded on each optical disc. Itis therefore possible to shorten the time for starting an optical discdevice, or prevent an increase in the starting time.

Inventors: Nomura; Masaru (Tenri, JP)


International Classification:

Expiration Date: 10/02/2013