Image Sensor Pixel Array for Auto Focusing
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Solution Overview
Problem
Current image capturing apparatuses require complex structures to perform accurate and fast image capturing operations, which complicates their design and functionality.
Innovation Solution
An image sensor with a simple structure incorporating a pixel array of sensing pixels and adjacent focusing pixels, each comprising a semiconductor layer, wiring layer, planarization layer, shielding layer, color filter layer, and micro lens layer, which allows for accurate and quick image capturing by selectively transmitting and focusing light based on wavelength and intensity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If additional sensors are added to achieve accurate auto focusing, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent makes the pixel array perform multiple functions: both image sensing and auto focusing. The same pixel array that captures images is also used to detect phase differences for auto focusing, eliminating the need for separate auto focusing sensors and reducing overall device complexity while maintaining measurement precision
Solution Approach 2:
The patent combines the auto focusing function with the image sensing function by integrating phase difference detection capability into the existing pixel array structure. Adjacent pixels are used to detect phase differences, merging two separate functions into one unified system
2Productivity
If complex structures are used to perform accurate and fast image capturing, then productivity is improved, but device complexity increases
Solution Approach 1:
The pixel array is designed to simultaneously perform image sensing and auto focusing operations, allowing the system to execute multiple functions with a single structure, thereby improving productivity without requiring additional complex components
Solution Approach 2:
The patent divides the pixel array into different functional regions: sensing pixels for image capture and focusing pixels for phase difference detection. This segmentation allows each region to be optimized for its specific function while working together within the same array structure
3Measurement precision
If multiple layers are added to the pixel structure to improve light control, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent applies different optical properties to different regions of the pixel array: color filters are selectively applied to sensing pixels while focusing pixels have different optical characteristics. This local differentiation optimizes each region for its specific function without requiring complex structures throughout the entire array
Solution Approach 2:
The patent uses a shielding layer that blocks only a portion of incident light rather than all light, allowing sufficient light to reach the photodetecting device while still providing the necessary phase difference detection capability. This partial blocking achieves the required measurement precision without excessive light interference
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 enables efficient and accurate auto focusing without the need for additional sensors, simplifying the image capturing apparatus structure while maintaining high performance, allowing for rapid image capture and reduced complexity.
Implementation Method 1
a semiconductor layer including a photodetecting device accumulating electric charges generated according to absorbed light from among the incident light
Implementation Method 2
the color filter layer selectively transmits the incident light according to a wavelength of the incident light
Implementation Method 3
the micro lens layer selectively focuses the incident light onto the photodetecting device
Implementation Method 4
a shielding layer formed in the planarization layer to block some of incident light to be incident to the photodetecting device
Data Source
AI summary
Provided are an image sensor and an image capturing apparatus including the image sensor. The image sensor includes a pixel array including: multiple sensing pixels outputting image signals respectively corresponding to intensities of incident light; and at least one pair of focusing pixels that are adjacent each other, and each outputting a phase difference of the incident light as a focusing signal; wherein each focusing pixel includes: a semiconductor layer including a photodetecting device accumulating electric charges generated according to absorbed light from among the incident light; a wiring layer formed on a first surface of the semiconductor layer and including wirings; a planarization layer having a first surface on a second surface of the semiconductor layer; a shielding layer formed in the planarization layer to block some of the incident light to be incident to the photodetecting device; and a color filter layer and a micro lens layer.