Write Head Yoke Windings for Servo Pattern Accuracy

The patent applies local quality by varying the winding density in specific regions of the coil to compensate for the proximity effect. Windings are arranged more densely near gaps that would otherwise receive excessive magnetic field strength, and less densely near gaps that would receive insufficient field strength. This localized adjustment ensures uniform magnetic field strength across all gaps despite the inherent proximity effect variations.

The patent changes the spatial distribution parameter of the windings to counteract the proximity effect. By carefully designing the winding pitch and density as a function of position relative to each gap, the effective magnetic field strength at each gap can be equalized. This involves adjusting winding parameters (density, spacing) to compensate for the non-uniform magnetic coupling between different gaps and the coil.

The patent makes different regions of the coil have different winding densities tailored to their specific relationship with each gap. This localized optimization allows the proximity effect to be harnessed constructively, where the naturally stronger coupling near certain gaps is compensated by reduced winding density, while regions with weaker coupling have increased density, achieving uniform field strength across all gaps.

The patent replaces traditional mechanical field uniformization methods (such as physical shims or adjustable components) with an electromagnetic field-based solution. By using the proximity effect itself and controlling winding distribution, the magnetic field uniformity is achieved through electromagnetic design rather than mechanical adjustment, simplifying the overall device structure despite the complex winding pattern.

The patent applies local quality by assigning different winding density characteristics to different regions of the coil corresponding to different gaps. Each gap region is optimized locally to receive the appropriate magnetic field strength, compensating for variations in proximity effect. This allows multiple gaps to operate reliably and uniformly, maintaining both high productivity through parallel servo track writing and reliability through consistent field strength across all gaps.

The patent segments the coil winding structure into distinct regions, each optimized for its associated gap. This segmentation allows independent optimization of winding density for each gap, ensuring that each servo write head receives the correct magnetic field strength. The segmented approach enables multiple gaps to function simultaneously with uniform performance, achieving both high productivity and reliability.