Camera Module Aperture Coating for Stray Light and Illuminance Balance
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Solution Overview
Problem
Conventional camera modules suffer from defects in the light-blocking layer, such as uneven coating, insufficient optical density, and stray light generation, which affect optical quality and relative illuminance, particularly in high-intensity lighting conditions.
Innovation Solution
A camera module with a light-blocking layer on a plastic optical element, featuring a specific shape and optical density distribution, including a main portion and a compensation portion, to control stray light and ensure uniform thickness and optical density, with a roughness of less than 1.2 um and defined angles and distances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If excessive shading is used in the light-blocking layer to achieve light-shielding effect, then light-shielding performance is improved, but optical quality of peripheral region is sacrificed and relative illuminance is reduced
Solution Approach 1:
The patent applies local quality by creating different regions within the light-blocking layer: a peripheral region with higher optical density for light-shielding and a central region with lower optical density for preserving illuminance. This spatial differentiation allows the light-blocking layer to simultaneously achieve effective light-shielding while maintaining adequate light transmission to the image sensor.
2Ease of manufacture
If conventional light-blocking layer is used, then manufacturing is simpler, but unable to form specific shape within micro-scale range and defects occur
Solution Approach 1:
The patent segments the light-blocking layer into distinct functional regions: a peripheral region with specific shape for light-shielding and a central region for light transmission. This segmentation allows each region to be optimized independently, with the peripheral region forming a specific micro-scale shape to block light while the central region maintains uniformity for adequate illuminance.
3Ease of manufacture
If light-blocking layer has insufficient optical density, then manufacturing is easier and uniformity is better, but light passes through and noise is formed in image sensor
Solution Approach 1:
The patent implements local quality by varying the optical density spatially: the peripheral region has higher optical density to prevent light leakage and noise, while the central region has lower optical density to maintain uniformity and adequate light transmission. This localized differentiation resolves the contradiction between manufacturing uniformity and noise prevention.
4Manufacturing precision
If light-blocking layer thickness is reduced, then manufacturing precision is improved and uniformity is better, but light-shielding capability is weakened and noise increases
Solution Approach 1:
The patent applies local quality by creating thickness differentiation: the peripheral region has greater thickness for enhanced light-shielding capability, while the central region has uniform, adequate thickness for maintaining precision. This spatial variation in thickness allows the light-blocking layer to achieve both manufacturing precision and reliable light-shielding performance.
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 improves optical quality by reducing stray light and enhancing uniformity, ensuring sufficient optical density and thickness, thereby improving imaging performance in various lighting conditions.
Implementation Method 1
a light-blocking layer 860 in the prior art is usually used to control a light path for eliminating light speckles and flares
Implementation Method 2
The imaging lens assembly includes a plastic optical element
Data Source
AI summary
A camera module includes an imaging lens assembly and an image sensor. The imaging lens assembly includes a plastic optical element with a light-blocking layer disposed on its transparent surface. The plastic optical element includes an optical effective area, and a peripheral region of the light-blocking layer forms a specific shape around the optical effective area so as to define an aperture region. The peripheral region includes a main portion and a compensation portion. The main portion is physically contacted with the transparent surface. The compensation portion is disposed on an edge of the main portion adjacent to the optical effective area, and an optical density of the compensation portion is lower than an optical density of the main portion. The image sensor is disposed on an image side of the imaging lens assembly for defining a maximum image height and further defining a relative illumination.