DEVICE FOR OPTICAL DISK Russian patent published in 2009 - IPC G11B7/09 G11B7/05 

FIELD: physics, computer engineering.

SUBSTANCE: according to the present invention device for optical disk is arranged with the possibility to read data from optical disk having multiple layers of information record, including the first layer of information record, distance of which from disk surface is relatively small, and the second layer of information record, distance of which from disk surface is relatively large. This device on optical disk comprises the following: section of focus adjustment that stipulates for location of light beam convergence point on randomly selected layer of information record of optical disk; section of tracking that stipulates for location of light beam convergence point on previously specified path of information record layer; and section for specification of amplification ratio arranged with the possibility to modify amplitude-frequency characteristic of at least one from focus adjustment section and tracking section. Section of amplification ratio switching sets cutoff frequency value in advance (frequency, at which amplification ratio is equal to 0 dB), when reading data from the first layer of information record by less than value of cutoff frequency in process of data reading from the second layer of information record.

EFFECT: provision of possibility to read data from optical disk having multiple layers of information record, including the first layer of information record, distance of which from disk surface is relatively small, and the second layer of information record, distance of which from disk surface is relatively large.

10 cl, 9 dwg