Magnetic Recording Testing Apparatus Synchronous Servo Read
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Solution Overview
Problem
Current methods for certify testing of magnetic recording media in hard disk drives are time-consuming and reduce productivity, as they require writing servo signals into the media, which takes 30 minutes to 2 hours per disk, and there is a need for high-precision testing that mimics actual usage in a shorter time frame.
Innovation Solution
A testing apparatus and method involving synchronous coaxial rotation of a discoid master medium and subject medium, with a first magnetic head reading servo information from the master medium and a second magnetic head conducting playback on the subject medium, allowing for high-precision testing without pre-writing servo information onto the subject medium, using a head stack assembly and signal processing mechanism to synchronize and test magnetic recording playback signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If servo information is written into the subject medium before certify testing, then high-precision testing close to actual usage can be conducted, but testing time increases to 30 minutes to 2 hours per disk, reducing productivity
Solution Approach 1:
The invention uses a master medium that contains pre-recorded servo information as a template. Instead of writing servo information onto each subject medium individually, the system reads servo information from the master medium and uses it to guide the testing of multiple subject media. This copying approach eliminates the time-consuming servo writing step while maintaining testing precision, thereby resolving the contradiction between measurement precision and productivity
Solution Approach 2:
The master medium is prepared in advance with all necessary servo information pre-recorded. This preliminary action of creating the master medium with servo patterns allows subsequent testing operations to proceed without the need to write servo information onto each subject medium, significantly reducing testing time while preserving the ability to conduct high-precision certify testing
2Productivity
If multiple subject media are tested sequentially with a single master medium, then productivity improves, but the master medium must be repeatedly accessed, potentially reducing reliability
Solution Approach 1:
The system incorporates verification mechanisms that continuously monitor the integrity of servo information read from the master medium during testing operations. By implementing feedback loops that detect and correct potential read errors, the system maintains high reliability even when the master medium is accessed repeatedly for testing multiple subject media, thus resolving the contradiction between improved productivity through sequential testing and potential reliability degradation from repeated access
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
Enables high-precision certify testing close to actual hard disk drive methods in a shorter time, improving productivity by eliminating the need for pre-writing servo information and allowing for continuous testing of multiple media without removing the master medium, thereby increasing throughput.
Implementation Method 1
a first magnetic head that reads servo information from the master medium
Implementation Method 2
a second magnetic head that conducts playback of the magnetic recording of the subject medium
Data Source
AI summary
A testing apparatus for magnetic recording medium and a testing method for magnetic recording medium is provided. Such a testing apparatus for magnetic recording medium, including: a rotary mechanism which causes synchronous, coaxial rotation of a master medium and a subject medium; a first support arm; a second support arm; a head stack assembly which causes synchronous movement of a first magnetic head and a second magnetic head by causing synchronous, coaxial rotation of the first support arm and second support arm, and which determines the position of the second magnetic head relative to the subject medium based on servo information signals obtained by loading servo information from the master medium into the first magnetic head; and a signal processing mechanism which synchronizes the servo information signals and magnetic recording playback signals, and which tests the magnetic recording playback signals of the subject medium.