Cyanine Dye Composition for Compact CMOS Near-Infrared Blocking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Complementary metal oxide semiconductor (CMOS) image sensors face challenges with near-infrared light sensitivity, leading to image distortion and noise due to large near-infrared light-blocking filters that hinder miniaturization and have variable blocking characteristics based on light incidence angle.
Innovation Solution
A near-infrared light-blocking filter composition using a mixture of cyanine dyes, specifically formulated to absorb near-infrared light across a wide spectrum, minimizing transmission while maximizing visible light transmission, with a layered structure including a substrate, anti-reflection layer, color filter, and microlens.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a near-infrared light-blocking filter is disposed under a module lens to absorb infrared light, then image distortion is reduced, but the filter size becomes relatively large which restricts miniaturization of the image sensor
Solution Approach 1:
The patent changes the chemical composition parameters of the filter by using a specific mixture of three cyanine dyes with defined absorption characteristics at different wavelengths. This compositional parameter change enables the filter to achieve effective near-infrared blocking with a reduced physical size compared to conventional single-dye or broad-spectrum filters.
Solution Approach 2:
The patent employs a composite material approach by combining three different cyanine dye compounds (first, second, and third cyanine dyes) into a multi-component filtering layer. Each dye component targets specific wavelength ranges, and their composite arrangement provides comprehensive near-infrared blocking while maintaining a compact form factor that allows filter size reduction.
2Object-affected harmful factors
If a conventional near-infrared light-blocking filter is used, then infrared light is blocked, but deviation in blocking characteristics depending on angle of incidence is relatively large causing noise due to light leakage
Solution Approach 1:
The patent applies local quality by assigning different functional characteristics to different dye components within the filter. Each cyanine dye is selected for its specific absorption spectrum and angular response characteristics, creating localized functional zones within the composite filter structure that collectively provide consistent blocking across varying angles of incidence.
Solution Approach 2:
The patent optimizes the absorption wavelength parameters and concentration ratios of the three cyanine dyes to achieve complementary angular response characteristics. By carefully selecting dyes with different spectral profiles and adjusting their mixing ratios, the filter maintains stable blocking performance across a range of incidence angles, reducing light leakage and noise.
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 cyanine dye mixture effectively blocks near-infrared light, reducing image distortion and noise, while maintaining high visible light transmission, thus enabling miniaturization and improved image quality in CMOS image sensors.
Implementation Method 1
A near-infrared light-blocking filter composition using a mixture of cyanine dyes, specifically formulated to absorb near-infrared light across a wide spectrum, minimizing transmission while maximizing visible light transmission
Data Source
AI summary
Provided is an image sensor including a substrate including a first surface and a second surface opposite to the first surface, and a near-infrared light-blocking filter disposed on the second surface of the substrate. The substrate includes a plurality of pixels, the plurality of pixels each includes a photoelectric conversion region, the near-infrared light-blocking filter includes a mixture of a first cyanine dye, a second cyanine dye, and a third cyanine dye, the first cyanine dye is represented by General Formula 1, the second cyanine dye is represented by General Formula 2, and the third cyanine dye is represented by General Formula 3 or General Formula 4.