Dimple Position Detection Device for Disk Drive Suspension
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing dimple position detection methods in hard disk drives face inaccuracies due to irregular dimple shapes and surfaces, leading to deviations in detected dimple top positions, especially when illumination light is intensified.
Innovation Solution
A dimple position detection device that adjusts the binarization level based on the intensity of reflected light to ensure the light spot region reaches a predetermined area, allowing for accurate detection of the dimple top position without intensifying the illumination light, thereby minimizing deviations from the actual position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If illumination light is intensified to obtain a light spot region above binarization level, then the light spot region can be obtained, but the detected position of dimple top deviates from actual position
Solution Approach 1:
The patent changes the binarization level parameter dynamically based on the intensity of reflected light from the dimple surface, rather than using a fixed binarization level. This allows the system to adapt to variations in illumination intensity and dimple surface conditions, obtaining accurate light spot regions without requiring intensified illumination that would cause position deviation.
Solution Approach 2:
The system implements feedback by measuring the intensity of reflected light from the dimple and using this information to adjust the binarization level accordingly. The light spot detection unit receives reflected light intensity information and determines the appropriate binarization level to ensure accurate light spot region extraction and dimple top position detection.
2Device complexity
If binarization level is fixed, then processing is simple, but light spot region cannot be obtained when reflected light is weak
Solution Approach 1:
The patent transforms the static binarization level into a dynamic parameter that adjusts based on reflected light intensity. The light spot detection unit dynamically determines the binarization level according to the actual lighting conditions and dimple surface reflectivity, ensuring reliable light spot region extraction across varying conditions without excessive complexity.
3Ease of manufacture
If dimple shape is distorted or surface is rough, then manufacturing is easier, but reflected light becomes weak and position detection becomes inaccurate
Solution Approach 1:
The system adapts to manufacturing variations by changing the binarization level parameter based on the actual reflected light intensity from the dimple surface. This allows accurate position detection even when the dimple shape is distorted or the surface is rough, as the binarization level adjusts to compensate for reduced reflected light.
Solution Approach 2:
The patent applies local quality by tailoring the binarization level to the specific local conditions of each dimple surface. Rather than using a universal fixed threshold, the system determines an appropriate binarization level for each dimple based on its unique reflected light characteristics, ensuring accurate detection despite manufacturing variations.
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 precise detection of the dimple top position even with irregular dimple shapes, preventing the light spot region from being displaced from the actual position, as seen with conventional dimmer control methods.
Implementation Method 1
irradiating the dimple with illumination light from behind it. Specifically, light reflected by the reverse surface of the dimple is imaged
Data Source
AI summary
A dimple position detection device for detecting a position of a dimple formed on a load beam is provided with an illumination device, imaging device, and image processing section. The illumination device directs illumination light toward the dimple. The imaging device receives reflected light from the dimple. The image processing section binarizes an image obtained by the imaging device. The image processing section maximizes a binarization level, binarizes the reflected light image, determines whether an area of a light spot region or on-region above the binarization level has a predetermined value, reduces the binarization level when the area of the light spot region is less than the predetermined value, and calculates the gravitational position of the light spot region with the predetermined value reached by the light spot region area.