Solid-State Imaging Pixel Layout for Oblique Light Noise Separation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing solid-state imaging devices face challenges in accurately eliminating the influence of obliquely incident light on charge accumulation sections while maintaining resolution and conversion efficiency, as previous methods either reduce resolution or fail to accurately correct for parasitic light sensitivity.
Innovation Solution
A solid-state imaging device with a configuration that includes a first charge holding section and a second charge holding section with no electrical continuity, where the second charge holding section overlaps the first in a planar layout, and utilizes specific transfer transistors to read charges from each section, allowing for accurate estimation and reduction of parasitic light sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a light shielding structure is provided to prevent light leakage into the charge accumulation section, then parasitic light sensitivity is reduced, but light leakage cannot be sufficiently prevented
Solution Approach 1:
The charge holding function is segmented into two independent sections: a first charge holding section for holding signal charges and a second charge holding section for holding noise charges. Both sections are electrically isolated from each other, allowing independent readout and processing to eliminate parasitic light sensitivity effects.
Solution Approach 2:
A second charge holding section is introduced as an intermediary to hold noise charges that result from parasitic light sensitivity. This intermediary structure allows the noise component to be separately captured and subtracted from the signal, effectively eliminating the harmful effect of oblique light leakage.
2Object-affected harmful factors
If existing correction methods are used to eliminate oblique light influence, then parasitic light sensitivity is reduced, but resolution is greatly reduced
Solution Approach 1:
Different regions of the pixel structure are assigned different functions: the first charge holding section processes signal charges for high-resolution imaging, while the second charge holding section processes noise charges for parasitic light sensitivity correction. This local differentiation allows simultaneous maintenance of resolution and correction effectiveness.
Solution Approach 2:
The correction approach transitions from spatial dimension (reducing pixel size) to functional dimension (adding a second charge holding section with overlapping planar layout). This dimensional shift allows noise correction without compromising the resolution-determining pixel dimensions.
3Object-affected harmful factors
If existing correction methods are used to eliminate oblique light influence, then parasitic light sensitivity is reduced, but conversion efficiency becomes low
Solution Approach 1:
The readout process uses periodic switching between the first and second charge holding sections. Transfer transistors alternately transfer charges from each section to floating diffusion nodes, enabling efficient sequential readout without requiring continuous switching operations that would reduce conversion efficiency.
Solution Approach 2:
The second charge holding section creates a copy of the noise component that can be separately processed. By copying the noise charges to a dedicated holding section, the system enables efficient noise subtraction without requiring complex continuous switching, thereby maintaining high conversion efficiency.
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 eliminates the influence of obliquely incident light while preserving resolution and conversion efficiency, providing a more accurate correction of parasitic light sensitivity components.
Implementation Method 1
a photoelectric conversion section that performs photoelectric conversion on light entering via the light receiving surface
Data Source
AI summary
A solid-state imaging device according to an embodiment of the present disclosure includes a light receiving surface, and two or more pixels opposed to the light receiving surface. Each of the pixels includes a photoelectric conversion section that performs photoelectric conversion on light entering via the light receiving surface, a first charge holding section that holds a charge transferred from the photoelectric conversion section, and a second charge holding section disposed at a position where all or a portion thereof overlaps the first charge holding section in a planar layout, and formed to have no electrical continuity to the first charge holding section. Each of the pixels further includes a first transfer transistor that transfers the charge held by the first charge holding section to a floating diffusion, and a second transfer transistor that transfers a charge held by the second charge holding section to the floating diffusion.