On-Chip Lens Infrared Absorption Layer Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image pickup devices face challenges in reducing the thickness of the imaging optical system while maintaining imaging capacity and durability, particularly due to the limitations of infrared absorption materials in terms of thickness, heat resistance, and thermal stability.
Innovation Solution
An image pickup device configuration that includes an on-chip lens, a low-refractive index layer, and an infrared absorption layer with a specific composition and lamination structure, using a high-refractive index material for the on-chip lens, a low-refractive index material for the layer, and an infrared absorption material with organic dyes and a binder resin having a glass transition temperature above 100°C, ensuring sufficient infrared absorption and thermal stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the thickness of the infrared cut filter is reduced to miniaturize the imaging apparatus, then the device size is reduced, but the infrared absorption capacity becomes insufficient
Solution Approach 1:
The patent uses a composite structure combining a resin layer containing infrared absorption particles with a separate infrared cut filter. The resin layer with particles provides preliminary infrared absorption, allowing the main filter to be thinner while maintaining overall absorption capacity. This composite approach enables miniaturization without sacrificing infrared rejection performance.
Solution Approach 2:
The infrared filtration function is segmented into two parts: a resin layer with dispersed infrared absorption particles for initial filtering, and a dedicated infrared cut filter for primary filtering. This segmentation allows each component to be optimized independently, enabling the overall system to be thinner while maintaining effective infrared absorption.
2Reliability
If the concentration of infrared absorption material is increased to improve infrared absorption, then the infrared absorption capacity is improved, but the visible light transmission is reduced and uniform film formation becomes difficult
Solution Approach 1:
The patent distributes infrared absorption particles locally within the resin layer at specific concentrations optimized for infrared absorption. This localized placement of absorption material allows the resin layer to provide infrared filtration without requiring high concentrations throughout the entire film, thereby maintaining visible light transmission and uniform film formation.
Solution Approach 2:
The patent optimizes the concentration of infrared absorption particles within a specific range (0.1-10 wt%) to balance infrared absorption capacity with visible light transmission. By carefully controlling this parameter, the resin layer achieves sufficient infrared filtration while maintaining good optical properties for visible light.
3Reliability
If the thickness of the on-chip lens or color filter is increased to achieve sufficient infrared absorption, then the infrared absorption capacity is improved, but the distance between the lens surface and photoelectric conversion device increases, deteriorating pixel resolution
Solution Approach 1:
The patent introduces a resin layer containing infrared absorption particles as an intermediary component between the on-chip lens and the infrared cut filter. This intermediary layer provides infrared absorption functionality without requiring increased thickness of the optical elements, thereby maintaining the precise distance between the lens surface and photoelectric conversion device for optimal pixel resolution.
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 allows for reduced thickness of the imaging optical system without compromising imaging capacity, while providing excellent durability by preventing thermal oxidation of the infrared absorption layer and maintaining infrared absorption capacity over time.
Implementation Method 1
an infrared absorption layer formed of an infrared absorption material including at least one kind of organic infrared absorption dye and binder resin
Implementation Method 2
an on-chip lens formed of a high-refractive index material
Data Source
AI summary
An image pickup device according to the present technology that includes an on-chip lens, a low-refractive index layer, and an infrared absorption layer. The on-chip lens is formed of a high-refractive index material. The low-refractive index layer is formed to be flat on the on-chip lens, the low-refractive index layer being formed of a low-refractive index material. The infrared absorption layer is formed of an infrared absorption material including at least one kind of organic infrared absorption dye and binder resin, a glass transition temperature of the binder resin being not less than 100° C., a concentration of the infrared absorption dye in the infrared absorption material being not less than 15 wt % and not more than 50 wt %, the infrared absorption layer being laminated above the low-refractive index layer.