JP2008234788A5

JP2008234788A5 -

Info

Publication number: JP2008234788A5
Application number: JP2007075699A
Authority: JP
Filing date: 2007-03-23
Publication date: 2010-03-25
Anticipated expiration: 2027-03-23

Claims

A circular disc body, a first pit row provided on one side of the disc radial direction from the center of the track provided along the circumferential direction of the disc, and on the other side of the disc radial direction from the center of the track A reproduction signal detector for irradiating a light beam to an optical disc having a second pit row provided in a shifted manner and detecting information recorded on the optical disc as a reproduction signal;
A scanner for scanning the light beam along the track;
An RF signal detector for detecting an RF signal based on a reproduction signal from the optical disc;
Based on the RF signal, a signal amplitude of CAPA1 based on the first pit row and a signal amplitude of CAPA2 based on the second pit row are detected as a signal indicating a positional deviation between the light beam and the track. A CAPA signal detector,
An arbitrary first radial tilt is set in the scanner to detect the difference between the CAPA1 signal amplitude and the CAPA2 signal amplitude on the land track, and the CAPA1 signal amplitude and the CAPA2 signal amplitude on the groove track. The amount of difference between
A second radial tilt different from the first radial tilt is set in the scanner to detect the difference between the CAPA1 signal amplitude on the land track and the CAPA2 signal amplitude, and the CAPA1 on the groove track. Detect the difference between the signal amplitude and the CAPA2 signal amplitude,
The third radial tilt, which is different from the first radial tilt and the second radial tilt, are set in the scanner, and the CAPA1 signal amplitude and the CAPA2 signal amplitude on the land track are set. And detecting the difference between the signal amplitude of CAPA1 and the signal amplitude of CAPA2 on the groove track,
A linear function approximate expression obtained from the relationship between the signal amplitude difference amounts of CAPA1 and CAPA2 with respect to the radial tilt is obtained for each of the land track and the groove track, and the optimum radial tilt value is detected, and the radial tilt value is set. A tilt correction control device.

A memory for storing a radial tilt shift amount between the optical disc and the light beam;
And a microcomputer for instructing to limit a change amount of the radial tilt based on information from the memory with respect to a measured radial tilt deviation amount between the optical disc and the light beam. Item 2. A tilt correction control apparatus according to Item 1 .

A circular disc body, a first pit row provided on one side of the disc radial direction from the center of the track provided along the circumferential direction of the disc, and on the other side of the disc radial direction from the center of the track A reproduction signal detector for irradiating a light beam to an optical disc having a second pit row provided in a shifted manner and detecting information recorded on the optical disc as a reproduction signal;
A scanner for scanning the light beam along the track;
An RF signal detector for detecting an RF signal based on a reproduction signal from the optical disc;
A wobble signal detector for detecting a wobble signal based on a reproduction signal from the optical disc;
Based on the RF signal or the wobble signal, the CAPA1 signal amplitude based on the first pit string and the CAPA2 signal based on the second pit string are used as signals indicating the positional deviation between the light beam and the track. A CAPA signal detector for detecting the amplitude,
An arbitrary first radial tilt is set in the scanner to detect the difference between the CAPA1 signal amplitude and the CAPA2 signal amplitude on the land track, and the CAPA1 signal amplitude and the CAPA2 signal amplitude on the groove track. The amount of difference between
A second radial tilt different from the first radial tilt is set in the scanner to detect the difference between the CAPA1 signal amplitude on the land track and the CAPA2 signal amplitude, and the CAPA1 on the groove track. Detect the difference between the signal amplitude and the CAPA2 signal amplitude,
The third radial tilt, which is different from the first radial tilt and the second radial tilt, are set in the scanner, and the CAPA1 signal amplitude and the CAPA2 signal amplitude on the land track are set. And detecting the difference between the signal amplitude of CAPA1 and the signal amplitude of CAPA2 on the groove track,
A linear function approximate expression obtained from the relationship between the signal amplitude difference amounts of CAPA1 and CAPA2 with respect to the radial tilt is obtained for each of the land track and the groove track, and the optimum radial tilt value is detected, and the radial tilt value is set. ,
Based on the comparison between the signal amplitude of the CAPA1 and the signal amplitude of the CAPA2, the two output results of the RF signal and the wobble signal are used when measuring the radial tilt deviation between the optical disc and the light beam. And a tilt correction control device for detecting a tilt amount.

When measuring the amount of radial tilt deviation between the optical disc and the light beam, the RF output used to read the information on the optical disc is used as the RF signal to be detected, or the focus and tracking error signal is generated. The tilt correction control apparatus according to claim 1 or 3 , wherein an AS signal obtained by adding a signal output from the optical pickup can be selected.

A circular disc body, a first pit row provided on one side of the disc radial direction from the center of the track provided along the circumferential direction of the disc, and on the other side of the disc radial direction from the center of the track The optical disc having a second pit row provided in a shifted manner is irradiated while scanning a light beam along the track, and the optical disc is detected while detecting information recorded on the optical disc as a reproduction signal. A tilt correction control method for correcting a radial tilt shift between the light beam and the light beam,
CAPA2 based on the signal amplitude of CAPA1 based on the first pit string and the CAPA2 based on the second pit string, which is a signal indicating a positional deviation between the optical beam and the track. Detecting as a difference amount of the signal amplitude of and outputting the detection result;
A tilt control step of setting a target position of the light beam on the track based on the detection result of the radial tilt deviation, and controlling scanning of the light beam so that the light beam follows the target position. And a tilt correction control method.