Plastic Optical Element Non-Transfer Portions Resin Shrinkage
Solution Overview
Problem
The existing optical scanners for color image forming apparatuses face challenges in reducing size due to the need for multiple imaging optical elements, which leads to increased size and complexity, and the molding process results in resin shrinkage issues causing sinks on non-optical surfaces, affecting imaging quality by degrading beam waist diameter.
Innovation Solution
A plastic optical element comprising a first and second lens with non-transfer portions on their non-optical surfaces, formed through a molding process where internal pressure is reduced to prevent resin shrinkage, and the non-transfer portions are intentionally created to avoid sink formation on optical surfaces, using amorphous resin and a mold assembly with movable inserts to shape the lenses accurately.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple imaging optical elements are used for each light beam, then imaging quality is maintained, but the size of the optical scanner increases
Solution Approach 1:
The patent combines multiple imaging optical elements into a single integrated optical element with multiple optical surfaces. Each optical surface is designed to focus a specific light beam, replacing the need for separate optical elements for each light beam while maintaining imaging quality and reducing the overall size of the optical scanner.
Solution Approach 2:
The integrated optical element serves multiple functions by having multiple optical surfaces, each capable of focusing a different light beam. This multi-functional design allows a single optical element to perform the work of multiple separate elements, reducing the number of components needed in the optical scanner.
2Manufacturing precision
If internal pressure of resin is reduced during molding to prevent deformation, then shape accuracy is improved, but resin shrinkage occurs causing sinks on optical surfaces
Solution Approach 1:
The patent applies local quality by creating a non-transfer portion specifically in the non-optical surface area, allowing the mold surface to be intentionally separated in this non-critical region. This localized approach enables the resin to shrink into the non-transfer portion without affecting the optical surfaces, maintaining both shape accuracy and surface integrity where needed.
Solution Approach 2:
The patent converts the harmful effect of resin shrinkage into a beneficial outcome by directing the shrinkage to occur in the non-optical surface region. The non-transfer portion acts as a sink for the shrinking resin, preventing sinks from forming on the optical surfaces while still accommodating the natural shrinkage behavior of the resin during cooling.
3Shape
If non-transfer portion is formed in non-optical surface to prevent sink on optical surface, then surface integrity is improved, but birefringence and wavefront fluctuations increase degrading beam waist diameter
Solution Approach 1:
The patent applies parameter changes by carefully controlling the depth, size, and position of the non-transfer portion within the non-optical surface. By optimizing these parameters, the design minimizes the impact on beam waist diameter while still providing enough space for resin shrinkage. The non-transfer portion is designed with specific dimensional parameters that balance surface integrity requirements with optical performance requirements.
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 configuration reduces the size of optical scanners, minimizes deformation, and maintains high imaging quality by controlling birefringence and wavefront fluctuations, preventing degradation of the beam waist diameter and enhancing the overall imaging performance.
Implementation Method 1
Forming an optical element using a resin injection molding process involves cooling the molten resin in the cavity inside the mold to harden the resin
Implementation Method 2
In order to reduce deformation of the molten resin in the cavity, the internal pressure of the resin in the cavity is reduced intentionally
Implementation Method 3
when the pressure of the molten resin in the cavity is reduced, the resin shrinks undesirably in the subsequent cooling and hardening process
Implementation Method 4
a plastic optical element for focusing light to a target
Implementation Method 5
controlling birefringence and wavefront fluctuations, preventing degradation of the beam waist diameter
Data Source
AI summary
A plastic optical element for focusing light to a target includes a first lens and a second lens. The first lens includes an incident surface, a projection surface opposite the incident surface, and a non-optical surface through which light does not pass and that includes a non-transfer portion. At least one light beam passes from the incident surface to the projection surface. The second lens includes an incident surface, a projection surface opposite the incident surface, and a non-optical surface through which light does not pass and that includes a non-transfer portion disposed opposite the non-optical surface of the first lens. At least one light beam passes from the incident surface to the projection surface. The non-transfer portions of the first lens and the second lens are portions on which no surface is transferred from a surface of a mold used to form the plastic optical element.