Thermally Assisted Magnetic Head Bit Inversion Positioning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Thermally assisted magnetic heads face challenges in achieving well-balanced performance among their three major elements: optical waveguide, surface plasmon generating element, and magnetic pole, as optimizing one element often deteriorates the performance of the others, making it difficult to maximize recording density and magnetic field efficiency.
Innovation Solution
A thermally assisted magnetic head design where the bit inversion starting region is located within one-half of the heating spot's diameter from its center, with the near-field light generating element positioned on the leading side of the main pole, allowing for efficient heating and magnetic field generation, thereby optimizing the relationship between the recording element and the near-field light generating element to enhance recording density and magnetic field gradients.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the main pole and magnetic shield are brought close together to increase recording magnetic field, then recording magnetic field strength is improved, but it becomes difficult to satisfy the requirement of not having metallic bodies around the optical waveguide
Solution Approach 1:
The magnetic shield is segmented into a leading shield and a trailing shield, with the leading shield positioned closer to the main pole to enhance the recording magnetic field in the recording region, while the trailing shield is positioned farther away to minimize its impact on optical waveguide performance. This segmentation allows different portions of the magnetic shield to serve different functions at different distances from the optical waveguide.
Solution Approach 2:
The magnetic shield structure is designed with non-uniform distribution, concentrating magnetic shielding functionality where most needed (near the main pole in the recording region) while reducing metallic body presence in regions critical for optical performance. This creates local optimization where magnetic field strength is maximized in the recording region without compromising optical waveguide performance elsewhere.
2Manufacturing precision
If the surface plasmon generating element is disposed as close as possible to the maximum point of recording magnetic field to maximize effective magnetic field gradient, then linear recording density is improved, but it complicates the design and reduces ease of manufacture
Solution Approach 1:
The surface plasmon generating element is extracted and positioned at a simplified location relative to the main pole, rather than requiring complex positioning at the exact maximum magnetic field point. This extraction allows the element to be placed in a more manufacturable position while still achieving effective thermal assistance for recording.
Solution Approach 2:
The design accepts a slight shift in the positioning parameters of the surface plasmon generating element from the theoretical optimal point, trading a small reduction in magnetic field gradient for significant simplification in manufacturing. This parameter adjustment makes the overall head structure more manufacturable while maintaining adequate recording performance.
3Force
If the bit inversion starting region is positioned at the leading edge of the main pole to maximize recording magnetic field, then recording magnetic field efficiency is improved, but it may fall outside the heating spot reducing thermal assistance effectiveness
Solution Approach 1:
The positions of the bit inversion starting region and the heating spot are merged or overlapped in the longitudinal direction, with the bit inversion starting region positioned within the heating spot boundaries. This spatial merging ensures that both the maximum recording magnetic field and the thermal assistance occur at the same location, maximizing recording efficiency.
Solution Approach 2:
The heating spot is positioned to precede or coincide with the bit inversion starting region in the recording direction, ensuring that the magnetic recording medium is pre-heated before the recording magnetic field is applied. This preliminary thermal action reduces coercivity in advance, enabling more efficient magnetization switching when the recording field arrives.
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 configuration ensures consistent and high-performance data writing by heating the magnetic recording medium close to its Curie point, increasing temperature and magnetic field gradients, which results in improved recording density and efficiency.
Implementation Method 1
a near-field light is generated from a near-field light generating element by using a laser beam and the magnetic recording medium is heated by heat of the near-field light
Implementation Method 2
a near-field light is generated from a near-field light generating element by using a laser beam
Implementation Method 3
a magnetic pole for generating a recording magnetic field
Data Source
AI summary
The present invention provides a thermally assisted magnetic head with improved recording performance. The thermally assisted magnetic head includes a recording element and a near-field light generating element. The recording element includes a main pole appearing on a medium-facing surface, and a bit inversion starting region intended to be a maximum recording magnetic field generating position is formed at a leading edge of the main pole. The near-field light generating element is located on a leading side of the main pole and capable of creating a heating spot due to a near-field light on a near-field light generating end face appearing on the medium-facing surface. The bit inversion starting region is located within one-half of a diameter of the heating spot from a center of the heating spot.