Heat-Assisted Magnetic Recording Head Adjustment via Local Lubricant Curing

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Solution Overview

Problem

The generation of lubricant-cured material during heat-assisted magnetic recording degrades write performance due to fluctuations in flying height, affecting transmission efficiency and recording performance.

Innovation Solution

A method to maintain a recording current below a threshold value and apply a light source drive current to generate a lubricant-cured material locally, minimizing its impact on non-target areas and ensuring stable recording and reproducing performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the flying height is lowered to scrape off the lubricant-cured material, then the write performance is improved, but the head-media contact increases causing wear and potential damage

Engineering Contradiction:

Improvewrite performanceVSAvoidhead-media contact wear

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies a light source drive current to locally heat and cure the lubricant material at the head-media interface, transforming it from a harmful adhesive layer into a beneficial protective layer. This parameter change (from uncured to cured state) resolves the contradiction by eliminating the need for low flying height while maintaining write performance.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent converts the harmful lubricant material that adheres to the NFT into a beneficial cured layer that improves laser transmission efficiency. By applying light to cure the lubricant in place, the previously harmful substance becomes a functional component that enhances performance without requiring head contact.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Object-affected harmful factors

If the flying height is increased to reduce wear, then the head-media contact is reduced, but the lubricant fills the head-media interface again degrading write performance

Engineering Contradiction:

Improvehead-media contact wearVSAvoidwrite performance

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent performs preliminary curing of the lubricant material by applying a light source drive current before normal recording operations. This preliminary action ensures the lubricant remains in a cured, non-adhering state, allowing the head to fly at optimal height without performance degradation from lubricant filling.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

By changing the physical state of the lubricant from uncured to cured through light application, the patent enables the head to maintain optimal flying height. The cured lubricant does not fill the head-media interface, thus maintaining write performance while reducing wear.

Inventive Principle:

Principle #35Parameter changes

3Use of energy by moving object

If the light source drive current is increased to generate more lubricant-cured material, then the transmission efficiency is improved, but the heat generation increases affecting recording stability

Engineering Contradiction:

Improvelaser transmission efficiencyVSAvoidheat generation

Core Design Contradiction:

Use of energy by moving objectVSTemperature

Solution Approach 1:

The patent applies the light source drive current locally at the head-media interface to cure the lubricant material only where needed. This localized application improves laser transmission efficiency at the critical interface while minimizing overall heat generation in the recording system.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent applies the light source drive current periodically or intermittently to cure the lubricant material rather than continuously. This periodic action maintains transmission efficiency while allowing heat dissipation between applications, preventing excessive temperature rise that would affect recording stability.

Inventive Principle:

Principle #19Periodic action

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 allows for efficient data recording and pattern formation without degrading performance by pre-forming the lubricant-cured material, reducing the time required for lubricant filling and maintaining optimal head positioning.

Implementation Method 1

a light source supplying light to the waveguide

Methodology Applied

Scientific EffectLight heating: Light

Implementation Method 2

applying a light source drive current emitting light to a light source to generate a lubricant-cured material

Methodology Applied

Scientific EffectPhotopolymerization: Photopolymerisation

Implementation Method 3

a near-field transducer generating near-field light

Methodology Applied

Scientific EffectNear-field light generation:

Implementation Method 4

a waveguide transmitting light to the near-field transducer

Methodology Applied

Scientific EffectOptical waveguide transmission: Waveguide (optics)

Data Source

PatentUS12456488B2Heat assisted magnetic recording and reproducing device and adjustment method of the same

Publication Date: 2025.10.28 KK TOSHIBA

AI summary

According to one embodiment, a method of adjusting a heat assisted magnetic recording and reproducing device maintains a heat assisted magnetic recording head of the heat assisted magnetic recording and reproducing device in an on-track state, maintains a recording current for data recording below a threshold value, and applies a light source drive current emitting light to a light source.