Image Sensor White Filter Units Low Light Noise Reduction
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Solution Overview
Problem
Imaging sensors in low light conditions suffer from larger noise and lower resolution due to insufficient light intake and inefficient signal processing.
Innovation Solution
The integration of white filter areas into some filter units of the image sensor, allowing increased light entry and using a Bayer Color Filter Array structure to process image signals, which enhances signal-to-noise ratio, brightness, and sharpness by merging pixel outputs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a microlens array is formed by a single-step spin coating process, then manufacturing simplicity is improved, but manufacturing precision deteriorates due to poor adhesion and lens shape control
Solution Approach 1:
The spin coating process is divided into multiple sequential steps (first spin coating step and second spin coating step) rather than a single step. This segmentation allows independent optimization of each step's parameters, enabling better control over the microlens shape and adhesion while maintaining manufacturing simplicity through automated sequential processing.
Solution Approach 2:
The first spin coating step performs preliminary action by forming an initial microlens structure with base adhesion properties. This preliminary layer prepares the surface for the second spin coating step, ensuring that the final microlens structure achieves the desired shape control and adhesion strength that would be difficult to obtain in a single step.
2Ease of manufacture
If conventional spin coating is used to form microlenses, then ease of manufacture is improved, but manufacturing precision deteriorates due to inability to control adhesion and shape
Solution Approach 1:
The coating process is segmented into multiple spin coating steps, each optimized for specific objectives. The first step focuses on establishing adhesion, while the second step refines the microlens shape. This segmentation enables independent control of adhesion and shape parameters without complicating the overall manufacturing process.
Solution Approach 2:
Different parameters are changed between the first and second spin coating steps, including coating solution composition, spin speed, and coating thickness. These parameter changes allow precise control over adhesion properties in the first step and lens shape in the second step, maintaining ease of manufacture through automated parameter adjustment.
3Manufacturing precision
If a two-step spin coating process is used, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
Multiple functional objectives (adhesion formation, microlens shaping, surface smoothing) are merged into a single integrated two-step spin coating process. This merging eliminates the need for separate manufacturing steps for each function, reducing overall device complexity while achieving high manufacturing precision through coordinated process parameters.
Solution Approach 2:
The spin coating process is designed with multi-functionality, where each coating step serves multiple purposes: the first step provides adhesion and initial shape, while the second step refines shape and surface quality. This universality reduces the need for specialized equipment or processes, maintaining simplicity while improving precision.
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 approach results in images with higher brightness, sharper details, and reduced noise in low light conditions, while maintaining or improving resolution through effective light management and signal processing.
Implementation Method 1
a photosensitive resin composition is applied to a substrate, and then the photosensitive resin composition is exposed to actinic radiation to form a microlens array
Data Source
Figure 1~2a
Figure 2b~2d
Figure 3~4a
AI summary
The present disclosure discloses an image sensor, an imaging device, a mobile terminal and an imaging method. The image sensor comprises a photosensitive pixel array and a filter arranged on the photosensitive pixel array. The filter comprises a filter unit array comprised a plurality of filter units, wherein each filter unit covers N photosensitive pixels, and some of the filter units comprise white filter areas. The white filter areas cover at least one of the N photosensitive pixels of the N photosensitive pixels, wherein a merged pixel is formed by the N photosensitive pixels covered by the same filter unit, wherein N is a positive integer.