Sharp Kabushiki Kaisha Corporation

Masaaki Hanano

Masaru Nomura

Takeshi Yamaguchi

Shigeo Terashima

An address information detecting apparatus in accordance with the present invention is arranged such that a first interpolation address generating section generates a first interpolation address according to a consistent signal supplied from an address comparison section, and a second interpolation address generating section generates a second interpolation address according to an error detection signal supplied from a CRC error detecting section. When a detected address is consistent with at least either of the first and second interpolation addresses and also no error is discovered according to the error detection signal, the detected address is adopted as absolute location information, whereas in situations other than the above, the first interpolation address is adopted as the absolute location information. On this account, even if an address error is mis-detected, the malfunction of the apparatus is prevented and proper recording/reproduction can be carried out.

Address information detecting apparatus and address information detecting method

The present invention is provided with a disturbance observer which outputs a compensating signal for compensating a driving signal of a linear motor in accordance with (1) an output signal of an acceleration sensor unit which mechanically detects an acceleration of the linear motor, the acceleration moving the optical pickup, and (2) the driving signal of the linear motor. A high pass filter which has a low frequency band cutoff frequency substantially same as that of the acceleration sensor unit is also provided on the path which is formed by connecting the input of the driving signal to the generated compensating signal in the disturbance observer. With the high pass filter, it is possible to prevent the linear motor from being driven too sensitively or too greatly by the disturbance observer due to the driving signal, vibrations, or shocks applied from outside, or noises from the acceleration sensor unit or the circuits, thereby avoiding the danger that the linear motor or the optical pickup is damaged.

Device for controlling the motor of a recording and reproducing apparatus

An offset compensation apparatus for a tracking error signal in an optical recording reproduction apparatus adds or subtracts a signal, which is proportional to the intensity of a read head laser beam, to or from a tracking error signal (which indicates the difference between a track of an optical disk and a a read head laser beam spot on the optical disk) so as to cancel offsets occur in the tracking error signal that are in proportion to the intensity of the read head laser beam and, thus, compensates for the offset in the tracking error signal. Since the offset compensation signal is also indicative of the amount of laser light irradiated to the optical disk, the offset can be compensated easily and accurately with a small scale simple circuit arrangement rather than using the larger-scale and more conventional divider attenuator combination of the prior art.

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Tenri, Japan

Masaaki Hanano