Optical disk drive and method for controlling sled motor within optical disk drive

1. An optical disk drive comprising:

a tracking actuator;

a sled motor;

a sled filter developing an output corresponding to low frequency components of displacement of said tracking actuator;

a pulse generating unit responsive to said output of said sled filter to develop drive pulses for driving said sled motor; and

a pulse waveform adjusting unit designed to adjust waveforms of said drive pulses,

wherein said pulse waveform adjusting unit adjusts a waveform of a relevant one of said drive pulses in response to said output of said sled filter and polarities of previous ones of said drive pulses.

2. The optical disk drive according to claim 1 , wherein said pulse generator develops said drive pulses in response to said output of said sled filter being out of a predetermined dead zone.

3. The optical disk drive according to claim 2 , wherein said pulse generator develops said previous drive pulses after a certain time when said output of said sled filter goes off said predetermined dead zone so that said previous drive pulses have a same polarity, and

wherein said pulse waveform adjusting unit counts a number of said previous drive pulses developed with polarities thereof being same, and increases at least one of a pulse width and a pulse height of said relevant one of said drive pulses when said number of said previous drive pulses developed reaches a predetermined number before said output of said sled filter comes within a predetermined range.

4. The optical disk drive according to claim 2 , wherein said pulse generating unit develops a latest one of said previous drive pulses to have a certain polarity, and

wherein said pulse waveform adjusting unit reduces at least one of a pulse width and a pulse height of said relevant one of said drive pulses when said output of said sled filter crosses a predetermined range to reach a value having a sign corresponding to a polarity opposite to said certain polarity of said latest drive pulse.

5. The optical disk drive according to claim 2 , wherein said drive pulses are each developed so that at least one of edges thereof is slanted.

6. An optical disk drive comprising:

an optical pickup including a tracking actuator driving an objective lens positioned opposed to an optical disk;

a sled motor designed to move said optical pickup across said optical disk; and

a control system controlling said sled motor including:

an RF circuitry developing a tracking error signal in response to an output of said optical pickup;

a tracking filter developing a tracking drive data corresponding to a displacement of said tracking actuator from said tracking error signal;

a sled filter developing an output corresponding to low frequency components of said displacement of said tracking actuator;

a pulse generating unit generating drive pulses for driving said sled motor in response to said output of said sled filter being out of a predetermined dead zone; and

a pulse waveform adjusting unit designed to adjust waveforms of said drive pulses,

wherein said pulse waveform adjusting unit adjusts a waveform of a relevant one of said drive pulses in response to said output of said sled filter and polarity of previous ones of said drive pulses.

7. A method for controlling a sled motor comprising:

developing an output data corresponding to low frequency components of displacement of a tracking actuator; and

generating drive pulses for driving a sled motor in response to an output of a sled filter being out of a predetermined dead zone,

wherein a waveform of a relevant one of said drive pulses is adjusted in response to said output of said sled filter and polarity of previous ones of said drive pulses.