Autofocus Read Head for Multi-Layer Optical Storage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current multi-layered optical data storage technologies face inefficiencies in reading data due to the need for precise focusing and the limitations of existing imaging systems, which result in high energy consumption and hardware requirements, as well as issues with data degradation and read disturb effects in other storage media.
Innovation Solution
A read head system equipped with an autofocus system and a wide-field imaging system that can capture images of voxels at variable depths, allowing for efficient data retrieval by identifying depth positions of voxels and focusing the imaging system accordingly, thereby improving data recovery rates and reducing hardware demands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If images are captured at many predetermined depths to ensure data recovery, then data recovery completeness is improved, but the majority of images are unusable due to being out of focus, limiting retrieval speed
Solution Approach 1:
The autofocus system performs preliminary scanning to identify the actual depth positions of voxels before the imaging system captures data images. This preliminary action prevents capturing useless out-of-focus images by pre-determining where voxels are actually located, thus improving retrieval speed while maintaining complete data recovery.
Solution Approach 2:
The autofocus system provides feedback about voxel depth positions to control the imaging system's focus. This feedback mechanism ensures that images are captured only at depths where voxels actually exist, eliminating wasted captures at empty depths and maximizing both reliability and productivity.
2Measurement precision
If high positional repeatability is required for reading and writing, then data accuracy is improved, but this is only practical on a laboratory scale, increasing device complexity
Solution Approach 1:
The autofocus system enables the imaging system to automatically determine and adjust to the correct focal depth without requiring external intervention or complex positioning mechanisms. The system self-adjusts based on real-time detection of voxel positions, achieving high positional accuracy while simplifying the overall device architecture.
Solution Approach 2:
The patent replaces complex mechanical positioning systems with an optical autofocus detection system. Instead of relying on precise mechanical repeatability for focusing, the system uses optical feedback to dynamically determine voxel positions, thereby achieving high measurement precision without proportionally increasing mechanical complexity.
3Productivity
If the imaging system is brought into focus on variable depths, then data retrieval efficiency is improved, but the system requires sophisticated focusing control, increasing device complexity
Solution Approach 1:
The patent merges the autofocus detection function with the imaging system into a single integrated unit. The same optical path and detector are used for both focusing control and data capture, eliminating the need for separate complex focusing mechanisms and reducing overall device complexity while maintaining high retrieval efficiency.
Solution Approach 2:
The imaging system is designed to serve multiple functions: it acts as both the data capture device and the autofocus detection device. This multi-functionality reduces the number of separate components needed and simplifies the focusing control system while still enabling efficient variable-depth data retrieval.
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
The solution enables more efficient data reading from multi-layered optical data storage media by optimizing focus positioning and image capture, enhancing data recovery rates while minimizing energy and hardware requirements.
Implementation Method 1
a light source for illuminating the area; and a detector for detecting light from the light source transmitted through the multi-layered optical data storage medium
Implementation Method 2
an imaging system for capturing images of groups of voxels, wherein the read head is configured to bring the imaging system into focus on variable depths in a multi-layered optical data storage medium
Implementation Method 3
voxels may be birefringent. In other words, voxels may display different refractive indices depending upon the polarisation and/or direction of incident light
Data Source
AI summary
Provided are a read head and methods for reading a multi-layered optical data storage medium comprising a transparent substrate having layers of voxels embedded therein. The read head comprises an imaging system for capturing images of groups of voxels, wherein the read head is configured to bring the imaging system into focus on variable depths in a multi-layered optical data storage medium; and an autofocus system for identifying depth positions of voxels in the multi-layered optical data storage medium by sampling an area in the optical data storage medium. The autofocus system comprises a light source for illuminating the area; and a detector for detecting light from the light source transmitted through the multi-layered optical data storage medium. A method of reading data from a multi-layered optical storage medium comprises capturing, using an imaging system, images of sectors in a first track. The multi-layered optical data storage medium and imaging system are held at fixed lateral positions during the capture of the images.