Optical Drive Disk Type Determination via Blank Area Reflection
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Solution Overview
Problem
Conventional methods for determining the type of a disk in optical drives often misidentify the disk type due to errors caused by the depth differences of pits in the data area, leading to incorrect reading of data.
Innovation Solution
A method that moves the pickup head to a blank area of the disk where no data is stored, irradiates it with a laser beam, and measures the time intervals for reflection from the surface and reflective layer to determine the disk type, avoiding the interference of pits in the data area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the laser beam irradiates the data area of the disk to determine disk type, then the measurement process can be completed, but the pits cause scattering or diffraction of reflected light leading to measurement errors
Solution Approach 1:
The patent extracts the measurement area from the data area containing pits to a blank area without pits. By moving the pickup head to a blank area on the disk where no data is stored, the measurement of reflection time is performed without the interference of pit-induced scattering or diffraction, thereby eliminating the source of measurement errors while maintaining determination speed
Solution Approach 2:
The patent introduces a blank area as an intermediary measurement zone. This blank area serves as a mediator between the laser beam and the data area, allowing the determination system to obtain accurate reflection time measurements without directly interacting with the problematic pit structures in the data area
2Ease of operation
If the pickup head remains on the data area for measurement, then no additional movement is required, but the pits cause errors in reflection time measurement
Solution Approach 1:
The measurement function is extracted from the data area to a blank area. The pickup head is moved to a blank area where measurements can be performed without the complicating factor of pit interference, simplifying the measurement process by removing the source of errors rather than adding complex compensation mechanisms
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
This approach reduces misidentification of disk types, ensuring accurate determination and correct data reading by eliminating the impact of pits on the laser beam reflection.
Implementation Method 1
the laser beam irradiates the blank area, and a first time interval for the laser beam to reflect from a surface of the blank area to the pickup head, and a second time interval for the laser beam to reflect from a reflective layer of the blank area to the pickup head, are both measured
Data Source
AI summary
A method for determining a disk type is provided. In the invention, a pickup head of a DVD optical drive is moved to a blank area of the disk where no data is stored. After rotation of the disk is stopped, the blank area is irradiated with a laser beam, and reflective signals reflected from a surface layer and a reflective layer of the disk are measured respectively. According to a time difference between the two reflective signals, the type of the disk placed in the DVD optical drive is determined. Therefore misjudgment because of effects of pits in a data area of the disk on the reflective signals can be avoided, so that the disk type can be accurately determined.