Imaging Element In-Layer Lens Layout for Wiring Reflection Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional imaging elements suffer from light reflection at the wiring layer, leading to image quality degradation due to fluctuating sensitivity caused by incident angle-dependent light reflection and color mixture.
Innovation Solution
Incorporation of on-chip lenses and in-layer lenses to collect and direct incident light to the photoelectric conversion unit, with in-layer lenses arranged in the same layer and optionally asymmetrically, and inclusion of color filters to manage specific wavelengths, reducing light reflection and enhancing image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a rear surface irradiation type imaging element is used to improve sensitivity, then sensitivity is improved, but light reflection from the wiring layer increases causing image quality degradation
Solution Approach 1:
An in-layer lens is introduced as an intermediary optical element between the on-chip lens and the photoelectric conversion unit. This in-layer lens specifically addresses the light reflection problem from the wiring layer by refracting and redirecting light paths, preventing reflected light from reaching adjacent pixels while maintaining the rear surface irradiation configuration for high sensitivity.
2Stability of the object's composition
If symmetric wiring configuration is used to reduce incident angle dependence, then sensitivity fluctuation is reduced, but light reflection from wiring layer cannot be prevented
Solution Approach 1:
The in-layer lens serves as a mediator that works in conjunction with the symmetric wiring configuration. While the symmetric wiring maintains sensitivity consistency across different incident angles, the in-layer lens additionally prevents light reflection from the wiring layer by optically managing light paths, thereby solving the reflection problem without compromising sensitivity stability.
3Ease of manufacture
If multiple in-layer lenses are arranged in the same layer to simplify manufacturing, then manufacturing complexity is reduced, but light collection efficiency may be compromised
Solution Approach 1:
The light collection function is segmented into multiple in-layer lenses arranged in the same layer as the on-chip lens. Each in-layer lens handles specific light paths from different incident angles, and their combined effect achieves comprehensive light collection efficiency while maintaining manufacturing simplicity through simultaneous formation in the same layer.
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 effectively reduces light reflection from the wiring layer, improving image quality by ensuring consistent light collection and minimizing sensitivity fluctuations, thereby enhancing the imaging performance.
Implementation Method 1
an on-chip lens configured to collect incident light from a subject
Implementation Method 2
a plurality of in-layer lenses that is arranged between the on-chip lens and the photoelectric conversion unit and that is configured to further collect the incident light that has passed through the on-chip lens
Implementation Method 3
a photoelectric conversion unit configured to perform photoelectric conversion on the collected incident light
Implementation Method 4
a color filter configured to allow light having a predetermined wavelength, out of the incident light that has passed through the on-chip lens, to transmit through the color filter
Data Source
AI summary
The deterioration of the image quality of an imaging element is to be prevented. The imaging element includes an on-chip lens, a photoelectric conversion unit, and a plurality of in-layer lenses. The on-chip lens collects incident light from a subject. The photoelectric conversion unit performs photoelectric conversion on the collected incident light. The plurality of in-layer lenses that is arranged between the on-chip lens and the photoelectric conversion unit and that is configured to further collect the incident light that has passed through the on-chip lens. Furthermore, the plurality of in-layer lenses allows the incident light that has passed through any one of the plurality of in-layer lenses to be incident on the photoelectric conversion unit.