Partitioned Image Sensor Lens Array with Variable Focal Lengths
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
There is a need for image capture units with lower profiles to reduce the overall size of electronic systems while maintaining image quality, as existing technologies often compromise on resolution and sharpness when minimizing the profile of image capture units.
Innovation Solution
A low profile image capture unit is achieved by using a low profile imaging lens and a partitioned image sensor with multiple focal lengths, where each partitioned area is covered by a respective lens, allowing for individual focus adjustment based on color, thereby maintaining image resolution and improving sharpness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a conventional single-lens design is used, then the profile can be reduced, but image resolution and sharpness deteriorate
Solution Approach 1:
The image sensor is divided into multiple partitioned areas (e.g., four quadrants), with each area covered by a dedicated microlens. This segmentation allows each lens to be optimized for specific color channels (RGB) with appropriate focal lengths, maintaining image quality while reducing the overall profile of the image capture unit.
Solution Approach 2:
Different microlenses are assigned different focal lengths based on their position and the color channel they serve. For example, red, green, and blue microlenses have different focal lengths optimized for their respective wavelengths. This local optimization maintains sharpness and resolution for each color channel while keeping the overall device profile compact.
2Measurement precision
If multiple lenses with different focal lengths are used for each color channel, then image sharpness and resolution are maintained, but device complexity increases
Solution Approach 1:
Multiple microlenses with different focal lengths are integrated into a single lens array structure that sits directly over the partitioned image sensor. This merging approach maintains the benefits of multiple focal lengths while reducing overall device complexity compared to using separate lens assemblies for each color channel.
Solution Approach 2:
The lens array serves multiple functions simultaneously: it focuses different color wavelengths onto their respective sensor partitions, enables color separation, and maintains a compact profile. This multi-functionality reduces the need for separate optical components for each function, simplifying the overall device design.
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 a compact image capture unit with preserved resolution and enhanced image sharpness by using a 2x2 lens array with different focal lengths for each color channel, improving modulation transfer function and overall image quality.
Implementation Method 1
Each microlens has a different focal length corresponding to a different color. The red microlens focuses red light onto the red image sensor area, the green microlens focuses green light onto the green image sensor area, and the blue microlens focuses blue light onto the blue image sensor area.
Data Source
Figure 1A~1B
Figure 2~3
Figure 4~5
AI summary
An apparatus includes an image sensor having N image sensor regions (222, 224) arranged thereon. A lens array having a including N lens structures (302, 304) is disposed proximate to the image sensor. Each one of the N lens structures is arranged to focus a single image onto a respective one of the N image sensor regions. The N lens structures include a first lens structure (302) having a first focal length (f1) and positioned the first focal length away from the respective one of the N image sensor regions (222). A second lens structure (304) having a second focal length (f2) is positioned the second focal length away from the respective one of the N image sensor regions (224). A third lens structure having a third focal length is positioned the third focal length away from the respective one of the N image sensor regions. The first, second and third focal lengths are different.