CMOS Image Sensor Microlens and Slit Grating Stray Light Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing solid-state imaging devices suffer from insufficient suppression of flare and ghost effects caused by stray light, which degrade image quality.
Innovation Solution
The implementation of a solid-state imaging element with a valid pixel region and a valid pixel peripheral region, where a plurality of microlenses are formed in the former and slit-type light diffraction gratings are formed in the latter, with the longitudinal direction of the gratings extending orthogonally to the side direction of the valid pixel region.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a convex body similar to an on-chip lens is provided on the surface of the valid pixel peripheral region to suppress stray light, then the generation of flare and ghost is reduced, but the suppression effect is not sufficient and image quality is still degraded
Solution Approach 1:
The patent changes the geometric parameters of the light diffraction grating, specifically using a slit type grating with longitudinal direction extending orthogonally to the side direction of the valid pixel region. This parameter change optimizes the diffraction pattern to more effectively redirect stray light away from the valid pixel region, achieving superior suppression compared to conventional convex bodies.
Solution Approach 2:
The patent combines microlenses in the valid pixel region with slit type light diffraction gratings in the valid pixel peripheral region. This composite structure integrates two different optical mechanisms - lens-based light condensation and grating-based light diffraction - to achieve comprehensive control over light paths and maximize stray light suppression while maintaining image quality.
2Reliability
If conventional stray light suppression measures are implemented, then some reduction in flare and ghost is achieved, but image quality remains degraded due to insufficient suppression
Solution Approach 1:
The patent converts the harmful stray light that would normally cause flare and ghost into beneficial diffraction patterns. The slit type light diffraction grating takes the stray light and diffracts it in controlled directions away from the valid pixel region, effectively transforming a harmful optical phenomenon into a useful mechanism for stray light management.
Solution Approach 2:
The patent introduces a new dimensional approach by using slit type gratings with specific longitudinal orientations orthogonal to the valid pixel region sides. This orthogonal arrangement creates a two-dimensional diffraction pattern that more comprehensively blocks stray light paths compared to conventional single-direction suppression methods, enhancing image quality.
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 suppresses stray light reflections, allowing for the capture of images with higher quality by reducing flare and ghost effects.
Implementation Method 1
a plurality of microlenses for condensing light is formed in a corresponding relation with the pixels
Implementation Method 2
a plurality of slit type light diffraction gratings is formed such that a longitudinal direction thereof extends in a direction orthogonal to a side direction of the valid pixel region
Data Source
AI summary
The present disclosure relates to an imaging element, a manufacturing method, and an electronic apparatus which enable an image having higher image quality to be captured. In a valid pixel region in which a plurality of pixels is arranged in a matrix, a plurality of microlenses for condensing light is formed in a corresponding relation with the pixels, and in a valid pixel peripheral region which is provided so as to surround an outside of the valid pixel region, a plurality of slit type light diffraction gratings is formed such that a longitudinal direction thereof extends in a direction orthogonal to a side direction of the valid pixel region. Then, an anti-reflection film is deposited on the microlenses and the slit type light diffraction gratings. The present technology, for example, can be applied to a CMOS image sensor.