Alternating Polarization Optical Filters for 3D Image Sensor Crosstalk
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Solution Overview
Problem
Conventional 3D imaging systems using a single camera with a single image sensor face challenges in separating left and right views due to pixel crosstalk when employing lenticular-lens or micro-lens arrays, which increases noise and reduces image quality.
Innovation Solution
The implementation of an image sensor with optical filters having alternating polarizations, arranged in a checkerboard pattern across the pixel units, allows for effective interleaving of left and right views, reducing pixel crosstalk and enhancing image separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a lenticular-lens or micro-lens array is used to interleave left and right images onto a single image sensor, then a single camera system can capture 3D images, but pixel crosstalk increases and image quality deteriorates
Solution Approach 1:
The image sensor is divided into multiple pixel units with alternating polarization orientations (horizontal and vertical). Each pixel unit captures light with a specific polarization, effectively segmenting the captured image data by polarization direction. This segmentation allows separation of left and right views without requiring complex lens arrays, thereby reducing pixel crosstalk while maintaining a single camera system structure.
Solution Approach 2:
Different regions of the image sensor (different pixel units) are assigned different local polarization properties (horizontal or vertical). This local quality variation enables each pixel unit to selectively capture light based on its polarization orientation, improving image separation quality while keeping the overall device structure simple.
2Reliability
If conventional optical methods are used for 3D imaging, then left and right views can be captured, but noise increases and image quality decreases due to pixel crosstalk
Solution Approach 1:
The invention converts the potentially harmful effect of light scattering and crosstalk into a beneficial separation mechanism by utilizing polarization properties. Since left and right views are encoded with orthogonal polarizations, the natural scattering that causes crosstalk in conventional systems actually helps differentiate between the two views when processed through polarization-sensitive pixel units, thereby improving view separation effectiveness while reducing noise.
Solution Approach 2:
The invention changes the parameter used for view separation from spatial positioning (in conventional lens-based systems) to polarization orientation. By encoding left and right views with different polarization states and using pixel units sensitive to specific polarization directions, the system achieves better view separation with reduced crosstalk noise.
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 solution enables improved separation of left and right views in 3D imaging, reducing noise and increasing image quality by utilizing alternating polarizations in the image sensor's optical filters, effectively addressing the limitations of existing systems.
Implementation Method 1
The left and right views may also be polarization-encoded. For example, the left view may horizontally polarized while the right view is vertically polarized. A pair of polarized goggles then may have a horizontal polarizer for the left eye and a vertical polarizer for the right eye.
Data Source
AI summary
An image sensor for three-dimensional (“3D”) imaging includes a first, a second, and a third pixel unit, where the second pixel unit is disposed between the first and third pixel units. Optical filters included in the pixel units are disposed on a light incident side of the image sensor to filter polarization-encoded light having a first polarization and a second polarization to photosensing regions of the pixel units. The first pixel unit includes a first optical filter having the first polarization, the second pixel unit includes a second optical filter having the second polarization, and the third pixel unit includes a third optical filter having the first polarization.