Autofocus Pixel Microlens Layout for Non-Circular Camera Lenses
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing camera devices face challenges in achieving accurate autofocusing due to differences in numerical apertures caused by lenses with non-circular shapes, which can result in errors in autofocus functionality.
Innovation Solution
The camera device incorporates a pixel array with first and second autofocus pixels, each having photodiodes arranged in different directions, and microlenses with varying heights and radii of curvature to compensate for the differences in numerical apertures, ensuring accurate autofocusing regardless of lens shape.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If lenses with non-circular shapes (edges extending in specific directions) are used in the optical module, then the device can achieve compact design and specific optical characteristics, but the numerical aperture and field of view vary in different directions, causing inaccurate autofocusing
Solution Approach 1:
The patent applies local quality by configuring different microlenses with different radii of curvature corresponding to different regions of the pixel array. Specifically, microlenses are assigned first radii of curvature for pixels in a first direction and second radii of curvature for pixels in a second direction, matching the directional characteristics of the non-circular lenses. This local adaptation compensates for the directional variation in numerical aperture caused by the non-circular lens shapes, thereby maintaining autofocusing accuracy across different regions.
Solution Approach 2:
The patent employs asymmetry by intentionally creating asymmetric microlens configurations that mirror the asymmetric nature of the non-circular lenses. The microlenses are designed with different radii of curvature in different directions, and the pixel array is configured with asymmetric arrangements of photodiodes. This asymmetric design directly addresses the asymmetric optical characteristics introduced by the non-circular lenses, enabling accurate autofocusing despite the lens shape variations.
2Adaptability or versatility
If photodiodes in autofocus pixels are arranged in different directions, then the pixel array can accommodate non-circular lens shapes, but the device complexity increases due to varied microlens configurations
Solution Approach 1:
The patent implements local quality by assigning specific microlens parameters (radii of curvature) to specific regions and directions within the pixel array. Each microlens is customized according to its position and the directional requirements of the corresponding non-circular lens, rather than using a uniform configuration. This localized customization enables the system to adapt to various lens shapes while maintaining a systematic and manageable design approach.
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 enhances the autofocusing function by accommodating variations in numerical apertures, leading to improved focusing accuracy and performance even with lenses having edges or non-circular shapes.
Implementation Method 1
each of the plurality of pixels includes a pixel circuit, at least one photodiode, a light transmission layer, and a microlens that are sequentially stacked
Implementation Method 2
an optical module including a plurality of lenses arranged to be in a path of travel of light incident on the image sensor
Data Source
AI summary
A camera device includes an image sensor including a pixel array and a logic circuit, with the camera device further comprising an optical module that includes a plurality of lenses arranged in a path of travel of light incident on the image sensor. The pixel array includes a plurality of pixels having a general pixel, a first autofocus pixel and a second autofocus pixel, and at least one of the plurality of lenses has an edge that extends in a first direction. A height of an upper surface of the microlens, included in the first autofocus pixel, is different from a height of an upper surface of the microlens included in the second autofocus pixel.