Abstract: The CPU includes: a data transmission instruction output processor; a failure detection signal input processor to which a failure detection signal is input from a failure detection processor for detecting a failure of an input unit; a data storage memory for, each time an input data update processor of the input unit updates data, storing the updated data; and a CPU operation processor for obtaining input data from the data storage memory and obtaining a detection signal from the failure detection signal input processor to perform operation processing. The CPU operation processor obtains periodic data as of an amount of time given by the following expression ago: {ROUNDUP(T22/T1)}×T1 where T22 is the failure detection processing time of the failure detection processor, T1 is the data transmission instruction output period of the data transmission instruction output processor, and ROUNDUP is a function of rounding up to the nearest integer.

Abstract: The CPU includes: a data transmission instruction output processor; a failure detection signal input processor to which a failure detection signal is input from a failure detection processor for detecting a failure of an input unit; a data storage memory for, each time an input data update processor of the input unit updates data, storing the updated data; and a CPU operation processor for obtaining input data from the data storage memory and obtaining a detection signal from the failure detection signal input processor to perform operation processing. The CPU operation processor obtains periodic data as of an amount of time given by the following expression ago: {ROUNDUP(T22/T1)}×T1 where T22 is the failure detection processing time of the failure detection processor, T1 is the data transmission instruction output period of the data transmission instruction output processor, and ROUNDUP is a function of rounding up to the nearest integer.

Abstract: A optical pickup includes: a laser diode; a driver including a first output end of a laser diode drive current; a first line electrically connected to the first output end of the driver and a first port of the laser diode; a second line provided adjacent to the signal line at at least one location or more and electrically connected to a second port of the laser diode; a printed circuit board including the first and second lines; and a metal heat dissipation cover for the driver. The first and second lines form a two layer structure in which the first and second lines are vertically disposed. The line width of the line provided close to the heat dissipation cover is wider than the line width of the other line between the first and second lines in the two layer structure.

Abstract: Due to the axial runout of an optical disc, a frequency of a high-frequency current to be superimposed onto a DC current could not be maintained. In order to solve the problem described above, a drive signal is generated by superimposing a high-frequency signal onto a DC current, the drive signal is applied to a laser beam light source, thereby the light source is driven; and a servo signal at a signal level corresponding to a defocus amount of the laser beam relative to the surface of the optical disc is generated based on a reflected light of the laser beam from the recording surface of the optical disc, and a low-frequency component of the servo signal is extracted, and thereby the frequency of the high-frequency signal to be superimposed onto the DC current in the light source driver is controlled based on the low-frequency component of the servo signal.

Abstract: Due to the axial runout of an optical disc, a frequency of a high-frequency current to be superimposed onto a DC current could not be maintained. In order to solve the problem described above, a drive signal is generated by superimposing a high-frequency signal onto a DC current, the drive signal is applied to a laser beam light source, thereby the light source is driven; and a servo signal at a signal level corresponding to a defocus amount of the laser beam relative to the surface of the optical disc is generated based on a reflected light of the laser beam from the recording surface of the optical disc, and a low-frequency component of the servo signal is extracted, and thereby the frequency of the high-frequency signal to be superimposed onto the DC current in the light source driver is controlled based on the low-frequency component of the servo signal.

Abstract: Provided is an optical disc device and a control method for the same that are capable of shortening processing time for spherical aberration correction amount adjustment. The optical disc device includes: a spherical aberration corrector that corrects spherical aberration of a light beam on an optical disc; and a tracking controller that performs tracking control based on a tracking error signal. In the spherical aberration correction amount adjustment by the spherical aberration corrector, the spherical aberration corrector is arranged so that: it holds a tracking error signal immediately before an spherical aberration correction amount is changed, and performs the tracking control based on the held tracking error signal while the spherical aberration corrector is changing the spherical aberration correction amount; or it moves a light beam scanning position on the optical disc to a predetermined track while the spherical aberration corrector is changing the spherical aberration correction amount.