Resonant channel for head-to-disc contact vibrations
View Patent ↗A channel senses head-to-disc contact vibrations in a vibrational noise spectrum produced in a mass storage device. The channel includes a suspension system with a suspension modal resonance. The channel includes a vibration sensor that senses head-to-disc contact vibrations through the suspension system. The vibration sensor has a sensor modal resonance that overlaps the suspension modal resonance.
1. A channel that senses head-to-disc contact vibrations for use in a mass storage device producing a vibrational noise spectrum characterized by first and second local maxima, the channel comprising:
a suspension system to suspend a head in relation to a disc, the suspension system having a suspension modal resonance spaced apart in frequency from the first and second local maxima; and
a vibration sensor coupled to sense head-to-disc contact vibrations through the suspension system, the vibration sensor having a sensor modal resonance spaced apart in frequency from the first and second local maxima and overlapping with the suspension modal resonance.
2. The channel of claim 1 , further comprising:
a pivotal mount that couples the head-to-disc contact vibrations from the suspension system to the vibration sensor.
3. The channel of claim 2 , further comprising:
a heater disposed on the head; and
a circuit disposed on the pivotal mount that receives a sensor output from the vibration sensor and that provides a heater current to the heater.
4. The channel of claim 3 wherein the circuit comprises a filter/amplifier with a pass band that is aligned with the suspension modal resonance and the sensor modal resonance.
5. The channel of claim 1 , further comprising a switch that interrupts a write current to the head when the vibration sensor senses head-to-disc contact vibrations that exceed a threshold.
6. The channel of claim 1 wherein the vibration sensor comprises a sensor modal resonance adjustment that is adjusted so that the sensor modal resonance overlaps the suspension modal resonance.
7. The channel of claim 1 , further comprising:
an electric pulse motor drive that drives the disc, and the electric pulse motor drive generates the first and second local maxima.
8. The channel of claim 1 , further comprising:
a head/gimbal assembly that includes the head, the head/gimbal assembly having a head/gimbal assembly modal resonance that overlaps the suspension modal resonance.
9. The channel of claim 8 , wherein the head/gimbal assembly modal resonance overlaps the sensor modal resonance.
10. A channel that senses head-to-disc contact vibrations for use in a mass storage device producing a vibrational noise spectrum characterized by first and second local maxima, the channel comprising:
a suspension system that couples between a head and a pivotal mount;
a vibration sensor that senses the head-to-disc contact vibrations coupled through the suspension system and that senses the vibrational noise spectrum; and
the vibration sensor having a sensor modal resonance, the suspension system having a suspension modal resonance; and the sensor and suspension modal resonances that overlap one another and that are spaced apart in frequency from the first and second local maxima to define a limited channel bandwidth for sensing the head-to-disc contact vibrations.
11. The channel of claim 10 , further comprising:
a circuit disposed on the pivotal mount and comprising a switch that interrupts a write current to the head when the vibration sensor senses head-to-disc contact vibrations that exceed a threshold.
12. The channel of claim 11 , further comprising:
a heater disposed on the head; and
the circuit receives a sensor output from the vibration sensor and provides a current to the heater that controls a head to disc spacing.
13. The channel of claim 10 , further comprising:
an electric pulse motor drive that drives a disc, and the electric pulse motor drive generates the first and second local maxima.
14. The channel of claim 10 , further comprising:
a head/gimbal assembly that includes the head, the head/gimbal assembly having a head/gimbal assembly modal resonance that overlaps the suspension modal resonance.
15. The channel of claim 14 , wherein the head/gimbal assembly modal resonance overlaps the sensor modal resonance.
16. A channel that senses head-to-disc contact vibrations for use in a mass storage device producing a vibrational noise spectrum characterized by first and second local maxima, the channel comprising:
a head, a pivotal mount, and a suspension system that couples between the head and the pivotal mount;
a vibration sensor on the pivotal mount that senses the head-to-disc contact vibrations and the vibration noise spectrum and that provides a sensor output;
the vibration sensor and suspension system having a mechanical modal resonance that defines a limited channel bandwidth spaced apart in frequency from the first and second local noise maxima; and
a circuit disposed on the pivotal mount that receives the sensor output and that comprises a switch that interrupts a write current to the head when the vibration sensor senses head-to-disc contact vibrations that exceed a threshold.
17. The channel of claim 16 , wherein the circuit provides a current to a heater that controls a head-to-disc spacing.
18. The channel of claim 16 wherein the circuit comprises a filter/amplifier with an electrical pass band that is aligned with the limited channel bandwidth.
19. The channel of claim 16 , further comprising:
an electric pulse motor drive that drives the disc, and the electric pulse motor drive generates the first and second local maxima.
20. The channel of claim 16 , further comprising:
a head/gimbal assembly that includes the head, the head/gimbal assembly having a head/gimbal assembly modal resonance that overlaps the suspension modal resonance.