Disk Storage Head Flying Height Regulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional disk storage apparatuses face challenges in regulating head flying height during seek operations, leading to potential contact with protrusions on the disk surface, which degrades write and read element characteristics, and result in reduced format efficiency due to the need for extensive track skip areas.
Innovation Solution
A disk storage apparatus with a controller that measures and manages a wait time for the head to increase flying height by reducing heater power before a seek operation, allowing the head to safely traverse track skip areas without extending them, thereby avoiding contact with protrusions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the track skip area is extended to include extra space, then head contact with protrusions is avoided, but format efficiency of the disk is reduced
Solution Approach 1:
The heater element is turned off before the seek operation begins, allowing the head to gradually return to its original flying height before entering the track skip area. This preliminary action ensures the head is in a safe state before traversing the protrusion-containing area, eliminating the need to extend the track skip area and preserving format efficiency
2Reliability
If the heater element is turned off before seek operation, then head projecting state is released to avoid contact, but time is needed to completely release the projecting state
Solution Approach 1:
The heater element is turned off in advance before the seek operation starts, allowing the thermal deformation to gradually subside and the head to return to its original flying height. This preliminary thermal management ensures the head is in a safe non-contact state before entering the track skip area, balancing reliability with minimal time loss
3Quantity of substance
If the head flying height is reduced to increase recording density, then recording density is improved, but probability of head contact with protrusions increases
Solution Approach 1:
The flying height of the head is made dynamically adjustable through heater element control. During normal operation, the head maintains a reduced flying height for high recording density. During seek operations across track skip areas, the heater is turned off to increase the flying height, dynamically adapting to operational conditions to prevent contact while maintaining density benefits
Solution Approach 2:
The physical state of the head (flying height) is changed by controlling the thermal parameter through the heater element. By adjusting the heater power, the head's thermal deformation and consequently its flying height are controlled, allowing the system to switch between low-height (high density) and high-height (safe traversal) states as needed
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively avoids head contact with protrusions during seek operations while maintaining efficient disk formatting by ensuring the head reaches a sufficient flying height before initiating the seek, thus minimizing performance degradation.
Implementation Method 1
a heater element is provided in the head. When predetermined power (heater power) is supplied to the heater element, the heater element produces heat and thus thermally deforms (expands) the head
Data Source
AI summary
According to one embodiment, a first slider of a disk storage apparatus includes a first head and flies over a first recording surface of a first disk. A heater element in the first head projects the first head toward the first recording surface of the first disk depending on heater power. A controller of the apparatus reduces a value for the heater power from a first value to a second value before performing a seek operation of moving the first head such that the first head moves across a concentric circular area including a protrusion on the first recording surface. The controller measures a wait time needed for a flying height of the first head to increase to a first flying height in response to the reduction and starts the seek operation after the wait time elapses.