Four-Lens Camera Assembly for Large Aperture Depth Measurement
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Solution Overview
Problem
Current three-dimensional depth measurement technologies, such as dual-camera, structured light, and TOF, face limitations in achieving a large aperture, high resolution, and high imaging quality, particularly in applications like VR/AR, robot vision, and autonomous driving.
Innovation Solution
A camera lens assembly comprising four lenses with specific refractive power distributions and configurations, including negative and positive refractive powers, concave and convex surfaces, and an infrared bandpass filter, optimized for a wide-angle, large aperture, and miniaturized design to enhance imaging quality and correct aberrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional camera lens design is used, then the structure is simple, but the aperture is small and imaging quality is insufficient for three-dimensional depth measurement
Solution Approach 1:
The lens assembly is divided into four distinct lens elements with different refractive powers and surface configurations. Each lens element serves specific optical functions, allowing the system to achieve high imaging quality through coordinated action of segmented components rather than a single complex lens
Solution Approach 2:
Different lens elements are designed with specific local characteristics: the first lens has negative refractive power with a concave image-side surface, the second lens has positive refractive power, the third lens has positive refractive power, and the fourth lens has negative refractive power with a convex object-side surface. Each lens element's local optical properties are optimized for its specific position and function in the optical path
2Reliability
If the aperture is increased to improve light gathering, then imaging quality improves, but aberrations increase and system sensitivity increases
Solution Approach 1:
The patent converts the harmful effect of aberrations introduced by large aperture into a benefit by using aspheric surfaces on the lens elements. The aspheric profiles are specifically designed to correct spherical aberration, coma, and other off-axis aberrations that would normally worsen with larger aperture, thereby allowing the system to maintain high imaging quality across the full field of view
Solution Approach 2:
The refractive indices and curvature radii of the lens elements are precisely optimized to balance aberrations. The first lens has negative refractive power, the second and third lenses have positive refractive power, and the fourth lens has negative refractive power. This parameter distribution optimizes the optical path to correct chromatic and monochromatic aberrations while maintaining large aperture performance
3Adaptability or versatility
If a wide field-of-view is achieved, then the application range expands, but distortion and aberration correction becomes more difficult
Solution Approach 1:
The patent employs aspheric surfaces on multiple lens elements, particularly on the object-side surface of the first lens and the image-side surface of the fourth lens. These curved surfaces are mathematically optimized to reduce distortion and correct off-axis aberrations across a wide field of view, enabling the system to achieve both wide angular coverage and high imaging precision at the edges of the field
Solution Approach 2:
The lens elements are designed with asymmetric surface profiles rather than simple spherical symmetry. The aspheric coefficients are specifically optimized to compensate for the asymmetric nature of off-axis light rays, thereby correcting coma and astigmatism that typically plague wide-angle lenses. This asymmetric design allows the system to maintain high image quality across the entire field of view
4Volume of moving object
If the lens assembly is miniaturized, then the structural size is reduced, but the aperture and imaging quality may be compromised
Solution Approach 1:
The four lens elements are arranged in a compact nested configuration along the optical axis, with each lens element positioned closely to the next. This nested arrangement minimizes the overall length and volume of the lens assembly while maintaining the necessary optical path length for high-quality imaging. The compact design allows the system to be miniaturized without sacrificing aperture or imaging performance
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 camera lens assembly achieves a large aperture, high resolution, and improved imaging quality, effectively addressing the limitations of existing technologies by balancing aberrations and reducing system sensitivity, making it suitable for diverse applications including three-dimensional depth measurement.
Implementation Method 1
The first lens has a negative refractive power, and an image-side surface of the first lens is a concave surface
Implementation Method 2
The second lens has a positive refractive power or a negative refractive power
Implementation Method 3
The third lens has a positive refractive power
Implementation Method 4
The fourth lens has a positive refractive power or a negative refractive power, and an image-side surface of the fourth lens is a convex surface
Implementation Method 5
optimized for a wide-angle, large aperture, and miniaturized design to enhance imaging quality and correct aberrations
Data Source
AI summary
The present disclosure discloses a camera lens assembly. The camera lens assembly has an effective focal length f and an entrance pupil diameter EPD, and includes a first lens, a second lens, a third lens, and a fourth lens in sequence from an object side to an image side along an optical axis. The first lens has a negative refractive power, and an image-side surface thereof is a concave surface. The second lens has a positive refractive power or a negative refractive power. The third lens has a positive refractive power. The fourth lens has a positive refractive power or a negative refractive power, and an image-side surface thereof is a convex surface. An effective radius DT11 of an object-side surface of the first lens and half of a diagonal length ImgH of an effective pixel area on an electronic photosensitive element of the camera lens assembly satisfy: 1.2<DT11/ImgH<2.6.