Optical Pickup Light Blocking Member for Adhesive Curing Control
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Solution Overview
Problem
In optical pickup devices using a blue-violet laser, the further curing of UV-curable adhesives leads to aberrations in plastic optical elements due to cure shrinkage and deformation, affecting the device's long-term quality and precision.
Innovation Solution
Incorporating first and second light blocking members that block blue-violet laser light from entering the adhesive, while allowing ultraviolet light for curing, thereby preventing further adhesive curing and reducing aberrations in optical elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a blue-violet laser is used as a light source for high-capacity optical discs, then the storage capacity increases, but the adhesive undergoes further curing reaction causing aberrations in plastic optical elements
Solution Approach 1:
The patent segments the optical path by introducing a light blocking member that divides the space into a light-transmitting region (for the laser beam) and a light-blocking region (for the adhesive). This segmentation prevents the blue-violet laser light from reaching the adhesive while maintaining the optical path integrity for signal transmission.
Solution Approach 2:
The light blocking member acts as an intermediary element between the blue-violet laser light source and the UV-curable adhesive. It selectively blocks harmful blue-violet wavelengths that cause further curing while allowing UV curing light to pass through during the bonding process, thus mediating between the conflicting requirements of high-capacity storage and optical element quality.
2Strength
If UV-curable adhesive is used to fix optical elements, then the bonding strength increases, but the adhesive shrinks and deforms during curing causing position and shape changes
Solution Approach 1:
The light blocking member is positioned in advance to prevent blue-violet laser light from reaching the adhesive during operation. This preliminary protective measure counteracts the harmful effect of further curing that would otherwise cause shrinkage, deformation, and position changes of the optical elements during device usage.
3Ease of manufacture
If plastic optical elements are used for cost reduction, then the manufacturing cost decreases, but the elements are more sensitive to adhesive curing effects and exhibit greater aberration
Solution Approach 1:
By segmenting the optical path with a light blocking member, the patent creates a protected environment for the adhesive that prevents blue-violet light exposure. This allows the use of cost-effective plastic optical elements without suffering from their higher sensitivity to adhesive curing effects, as the harmful light is blocked from reaching both the adhesive and the plastic elements.
4Volume of moving object
If adhesive is applied in the vicinity of the optical element for size reduction, then the device size decreases, but the adhesive is more easily irradiated by light causing further curing
Solution Approach 1:
The light blocking member serves as an intermediary that specifically targets and blocks blue-violet laser light from reaching the adhesive in the size-reduced configuration. This allows the adhesive to be placed close to the optical element for miniaturization while the light blocking member prevents harmful light exposure that would cause further curing.
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 effectively reduces aberrations in optical elements by preventing light from irradiating the adhesive, allowing for easier production and maintaining device quality over time.
Implementation Method 1
at least one of the first and second light blocking member blocks the light in the first wavelength range and transmits light in a second wavelength range included in an ultraviolet wavelength range of 10 to 400 nm
Implementation Method 2
The adhesive is a resin that can be cured by ultraviolet light (UV-curable resin). The UV-curable adhesive is cured when it is exposed to ultraviolet irradiation to fix the optical element
Data Source
AI summary
An optical pickup device includes: a light source for emitting light in a first wavelength range; an optical element for transmitting the light; a supporting member for supporting the optical element through an adhesive; a first light blocking member for blocking the light emitted from the light source from entering the adhesive when the optical element guides the emitted light to the optical disc; and a second light blocking member for blocking the light reflected from the optical disc from entering the adhesive when the optical element guides the reflected light to the detector unit. In this optical pickup device, at least one of the first and second light blocking member blocks the light in the first wavelength range and transmits light in a second wavelength range.