Magnetic Storage Clock Control for Frequency Displacement
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Solution Overview
Problem
Conventional magnetic storage systems face inefficiencies due to frequency displacement caused by decentering, leading to tracking errors and the necessity of extra data buffers, which reduces format efficiency.
Innovation Solution
A magnetic storage control apparatus and method that measures the time for a head to scan data areas on a recording medium with reference signals, calculates a setting value for the recording clock frequency, and generates a recording clock based on these measurements to reduce errors and maintain consistent bit length.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a fixed recording clock frequency is used for data recording, then the recording process is simple, but frequency displacement occurs due to decentering causing non-constant recording bit length and requiring extra data buffers
Solution Approach 1:
The patent dynamically changes the recording clock frequency based on the measured linear velocity of the head. Instead of using a fixed frequency, the system adjusts the clock frequency to match the actual head movement speed, ensuring constant recording bit length while accommodating decentering variations without requiring complex buffer management
Solution Approach 2:
The system measures the head scanning time across multiple data areas to determine linear velocity, then uses this measurement feedback to generate an optimized recording clock frequency. This closed-loop approach ensures the recording clock adapts to actual physical conditions, eliminating frequency displacement errors while maintaining recording simplicity
2Manufacturing precision
If error correction based on servo information is applied, then frequency displacement is corrected, but tracking errors occur due to group delay
Solution Approach 1:
The patent extracts the head scanning time measurement from the traditional servo-based frequency correction method. By measuring the actual time taken to scan data areas directly, the system obtains pure velocity information without the tracking errors and group delays introduced by servo sector-based correction methods
Solution Approach 2:
The system introduces head scanning time as an intermediary measurement parameter between the physical head movement and the recording clock generation. This intermediary measurement provides accurate velocity information that can be used to generate the optimal recording clock frequency without introducing tracking errors
3Reliability
If extra data buffers are ensured to accommodate frequency displacement, then recording reliability is maintained, but format efficiency decreases
Solution Approach 1:
The system performs preliminary measurement of head scanning time across multiple data areas before generating the recording clock. By determining the optimal clock frequency in advance based on actual velocity measurements, the system eliminates the need for extra data buffers while ensuring reliable recording from the start
Data Source
AI summary
A magnetic storage control apparatus for controlling a magnetic storage apparatus that uses a recording medium having a plurality of reference signals on its track and having a data area between the reference signals. The apparatus includes: a measurement section that reproduces the reference signal in a predetermined track of the recording medium and measures, for each data area, the time for a head to scan the data area to obtain a measurement value; a calculation section that calculates a setting value concerning the frequency of a recording clock used in data recording based on the measurement values of a plurality of data areas obtained by the measurement section; and a generation section that generates the recording clock based on the measurement values obtained by the measurement section and setting value calculated by the calculation section.