Optical Storage Direct Read After Write Single OPU Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional optical data storage devices require multiple Optical Pickup Units (OPUs) to achieve Direct Read After Write (DRAW) functionality, increasing complexity and cost.
Innovation Solution
An optical storage system using a single OPU with a first coherent light source for writing and a second coherent light source for continuous wave reading, where light from both sources is combined and focused to specific spots on the optical medium, allowing direct data verification during the write process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple independent OPUs are used to achieve DRAW functionality, then direct read after write capability is provided, but device complexity and cost increase
Solution Approach 1:
The patent merges the write and read functions into a single OPU by combining light from a write laser and a read laser through a beam combiner. The write laser operates at higher power for data writing, while the read laser operates at lower power for immediate verification. Both beams are combined and directed through the same optical path to the storage medium, eliminating the need for multiple separate OPUs while maintaining DRAW capability
Solution Approach 2:
The single OPU is designed to perform multiple functions: it can write data using the write laser, read data using the read laser, and verify written data immediately through direct read after write. The optical pickup unit serves as a multi-functional device that integrates both write and read operations, as well as immediate verification, into one unified system
2Reliability
If multiple independent OPUs are used to achieve DRAW functionality, then direct read after write capability is provided, but cost increases
Solution Approach 1:
The patent merges the write and read functions into a single OPU by combining light from a write laser and a read laser through a beam combiner. The write laser operates at higher power for data writing, while the read laser operates at lower power for immediate verification. Both beams are combined and directed through the same optical path to the storage medium, eliminating the need for multiple separate OPUs while maintaining DRAW capability
Solution Approach 2:
The single OPU is designed to perform multiple functions: it can write data using the write laser, read data using the read laser, and verify written data immediately through direct read after write. The optical pickup unit serves as a multi-functional device that integrates both write and read operations, as well as immediate verification, into one unified system
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 direct read after write functionality with reduced complexity and cost by using a single OPU, ensuring efficient data verification and storage without altering previously written data.
Implementation Method 1
an optical head having a first coherent light source modulated at higher power during writing of data to the optical medium and a second coherent light source operating in a continuous wave mode at lower power
Implementation Method 2
optics that combine light from the first and second light sources and focus light from the first coherent light source to a first spot of a selected track on the optical medium and focus light from the second coherent light source to a second spot on the selected track downstream from the first spot
Implementation Method 3
the optics directing reflected light from the optical medium to a photodetector
Data Source
AI summary
A system and method for providing direct read after write functionality in an optical data storage device include an optical head having a first coherent light source modulated at higher power during writing of data to the optical medium and a second coherent light source operating in a continuous wave mode at lower power while the first coherent light source is writing data. Optic components combine light from the first and second light sources and focus light from the first coherent light source to a first spot of a selected track on the optical medium and focus light from the second coherent light source to a second spot on the selected track downstream from the first spot relative to movement direction of the optical medium to read and verify the data directly after writing during the write process rather than in a separate verification process.