Optical disk device
AssigneeFunai Electric Co., Ltd.
InventorTakao Mizuno
Life of this patent
Estimating the term…
Abstract
This optical disk device includes a pickup head, a spindle motor, a signal generation unit, a runout amount calculation unit, and an out of balance disk detection unit. The signal generation unit generates a tracking error signal. The runout amount calculation unit controls the rotational speed of the spindle motor to first and second disk rotational speeds, and obtains, at these rotational speeds, runout amounts TE1 and TE2 of a tracking error signal, and runout amounts FE1 and FE2 of a focus error signal. And an out of balance disk detection unit detects that this optical disk is an out of balance disk, if the absolute value of (TE2×FE2)/(TE1×FE1) is greater than or equal to a threshold value.
Claims3
An optical disk device, comprising:
- a pickup head which irradiates laser light upon a disk which is loaded into a main body of said device, and detects light reflected from said disk;
- a spindle motor which rotates said disk;
- a signal generation unit which generates, from the reflected light from the disk which has been detected by said pickup head, a focus error signal which indicates the amount of deviation between the recording surface of said disk and the position of condensation of the laser light irradiated from said pickup head, and a tracking error signal which indicates the amount of deviation between the center of a track upon said disk and the irradiation position of the laser light irradiated from said pickup head;
- a runout amount calculation means which, along with controlling the rotational speed of said spindle motor to a first disk rotational speed and obtaining a runout amount TE1 of said tracking error signal and a runout amount FE1 of said focus error signal, also controls the rotational speed of said spindle motor to a second disk rotational speed which is higher than said first disk rotational speed and obtains a runout amount TE2 of said tracking error signal and a runout amount FE2 of said focus error signal;
- and
- an out of balance disk detection means which detects that said disk which is loaded is an out of balance disk, if an absolute value V2/V1 obtained by dividing a second servo runout amount V2 obtained by multiplying TE2 by FE2 by a first servo runout amount V1 obtained by multiplying TE1 by FE1 is greater than or equal to a first threshold value.
Dependencies are inferred from the claim text.