초록 ▼

Apparatus suppresses seek-induced vibration in a disc drive. The apparatus is responsive to a selected bang-bang command to provide an operating signal to the actuator, such as a voice coil motor, representing the selected bang-bang command with damped amplitudes of dominant vibration mode frequenci

Apparatus suppresses seek-induced vibration in a disc drive. The apparatus is responsive to a selected bang-bang command to provide an operating signal to the actuator, such as a voice coil motor, representing the selected bang-bang command with damped amplitudes of dominant vibration mode frequencies of the selected bang-bang command. One example of the apparatus is a finite impulse response filter having a discrete transfer function of C(1+al1z-l+al2z-l·2+ . . . +alrz-l·r), where C is a constant, al1,al2,. . . alrrepresent impulse amplitudes at spaced positions within a sample period and z-l·1,z-l·2,. . . z-l·rrepresent delay components at the respective spaced positions. In a preferred embodiment, the finite impulse response filter employs a pole-zero cancellation technique to damp amplitudes of selected frequencies. The discrete transfer function is derived based on a conjugate pair of poles in an s-domain for each of a plurality of vibration frequencies of where ζiis the damping ratio and ωniis the natural frequency for the i-th mode.

대표청구항 ▼

Apparatus suppresses seek-induced vibration in a disc drive. The apparatus is responsive to a selected bang-bang command to provide an operating signal to the actuator, such as a voice coil motor, representing the selected bang-bang command with damped amplitudes of dominant vibration mode frequenci

Apparatus suppresses seek-induced vibration in a disc drive. The apparatus is responsive to a selected bang-bang command to provide an operating signal to the actuator, such as a voice coil motor, representing the selected bang-bang command with damped amplitudes of dominant vibration mode frequencies of the selected bang-bang command. One example of the apparatus is a finite impulse response filter having a discrete transfer function of C(1+al1z-l+al2z-l·2+ . . . +alrz-l·r), where C is a constant, al1,al2,. . . alrrepresent impulse amplitudes at spaced positions within a sample period and z-l·1,z-l·2,. . . z-l·rrepresent delay components at the respective spaced positions. In a preferred embodiment, the finite impulse response filter employs a pole-zero cancellation technique to damp amplitudes of selected frequencies. The discrete transfer function is derived based on a conjugate pair of poles in an s-domain for each of a plurality of vibration frequencies of where ζiis the damping ratio and ωniis the natural frequency for the i-th mode. a plane parallel plate disposed at an object side location which is to be brought into contact with the immersion liquid. 6. The liquid immersion objective lens system according to claim 3 comprising a plane parallel plate disposed at an object side location which is to be brought into contact with the immersion liquid.