Microlens Array Layout for Image Sensors With Reduced Petal Flare
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current image sensors face challenges in achieving improved output quality due to issues with microlens arrangement and diffraction patterns, leading to petal flare and reduced signal-to-noise ratio.
Innovation Solution
The proposed image sensor incorporates a periodic structure of microlenses with varying sizes and offsets, arranged in an M×N array, which disperses diffracted light and reduces petal flare by increasing the arrangement period of the grid pattern.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If microlenses are arranged in a regular grid pattern, then manufacturing is simple, but diffraction patterns cause petal flare and reduced signal-to-noise ratio
Solution Approach 1:
The patent applies asymmetry by intentionally introducing irregularities in the microlens array configuration. Specifically, certain microlenses are removed or displaced from their expected positions in a regular grid, creating an asymmetric pattern that disrupts the formation of diffraction patterns and petal flare while maintaining overall periodic structure for manufacturability.
2Object-affected harmful factors
If microlens arrangement period is increased, then petal flare is reduced, but device complexity increases
Solution Approach 1:
The patent segments the microlens array into multiple periodic structures with different periods and orientations. Instead of using a single complex irregular pattern, the array is divided into repeating units of simpler periodic structures, which reduces manufacturing complexity while still achieving petal flare suppression through the combined effect of multiple periods.
Solution Approach 2:
The patent employs periodic action by creating multiple periodic structures with different periods (e.g., 2×2, 3×3, 4×4 microlens groups) arranged in a larger periodic pattern. This layered periodic approach systematically suppresses diffraction patterns at multiple spatial frequencies, reducing petal flare while maintaining manufacturability through repetition of standardized units.
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 effectively reduces petal flare visibility and enhances the signal-to-noise ratio by dispersing diffracted light, thereby improving image sensor output quality.
Implementation Method 1
a plurality of microlenses on the color filters
Implementation Method 2
The plurality of microlenses are arranged in an array of the microlenses with a periodic structure... disperses diffracted light and reduces petal flare
Implementation Method 3
Each of the pixels includes a photodiode. The photodiode serves to convert incident light into electrical signals
Data Source
AI summary
Disclosed is an image sensor comprising a first substrate including pixel sections each of which includes a photoelectric conversion region; a plurality of color filters on the pixel sections and on a first surface of the first substrate, and a plurality of microlenses on the color filters. An array of the microlenses includes a repetitive periodic structure. The periodic structure includes a first microlens, a second microlens, and a third microlens that are sequentially arranged adjacent to each other along a first direction. A first spacing in the first direction between the first and second microlenses is substantially the same as a second spacing in the first direction between the second and third microlenses. A first pitch in the first direction between the first and second microlenses is different from a second pitch in the first direction between the second and third microlenses.