Compact Wide Angle Lens Design for Mobile Imaging
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Solution Overview
Problem
Conventional wide angle lenses for portable electronic devices, such as mobile phones, are too large and require additional flash due to a maximum aperture of f/8, limiting their compactness and functionality for capturing large areas, especially in self-portraits.
Innovation Solution
A compact wide angle lens design comprising a first positive convex lens element made of optical glass, a second concavo-convex negative lens element made of optical plastic, and a third high-aperture size convex aspheric lens element made of optical plastic, optimized to achieve an angle of view up to 70 degrees with a total length of less than 8 mm, and a maximum aperture of f/2.8.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional wide angle lens design is used to achieve an angle of view of 70 degrees or more, then the angle of view requirement is satisfied, but the lens length becomes longer than 21.8 mm making it too large for portable electronic devices
Solution Approach 1:
The lens is divided into three separate lens elements (first lens element, second lens element, and third lens element) with specific optical characteristics. This segmentation allows each element to contribute to different aspects of the optical performance, achieving a 70-degree angle of view while keeping the overall lens length compact at less than 8 mm.
Solution Approach 2:
The patent employs aspheric surfaces with specific conic constants (k values) for each lens element to optimize the optical path. By carefully selecting and adjusting these parameter values, the lens achieves wide angle of view while maintaining compact dimensions and proper focus characteristics.
2Device complexity
If a conventional wide angle lens with maximum aperture of f/8 is used, then the lens structure can be simplified, but additional flash is required to provide enough light, which would further augment the size of the portable electronic device
Solution Approach 1:
The patent achieves a maximum aperture of f/2.8 by optimizing the aperture stop position and size relative to the lens elements. This larger aperture allows sufficient light to reach the image sensor without requiring additional flash, while the aspheric surface designs maintain optical quality across the wide field of view.
3Length of moving object
If a compact lens design with total length of less than 8 mm is used, then the lens can be equipped in portable electronic devices, but achieving an angle of view of 70 degrees or more becomes more difficult
Solution Approach 1:
The patent utilizes aspheric surfaces that extend the optical path in multiple dimensions rather than simply increasing the axial length. The curved and waveshaped surfaces redirect light rays through optimized paths, achieving wide angle of view within a compact axial length of less than 8 mm.
Solution Approach 2:
The lens employs a combination of different optical materials with specific refractive indices and dispersion characteristics for each of the three lens elements. This composite material approach allows optimization of both the angle of view and compactness by selecting materials that provide the desired optical properties for each element's specific function.
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 compact wide angle lens design provides an effective angle of view of 70.35 degrees with improved image quality, suitable for high-resolution digital sensors, while maintaining a small form factor and reducing the need for additional lighting, thus enhancing the imaging capabilities of portable electronic devices.
Implementation Method 1
a first positive convex lens element, a second concavo-convex negative lens element, and a third high-aperture size convex aspheric lens element
Data Source
AI summary
A wide angle lens includes, in order from an object side, a first positive convex lens element, a second concavo-convex negative lens element, and a third lens element. The first lens element is made of an optical glass and defines a first convex aspheric surface on the object side and a second plane aspheric surface. The second lens element is made of an optical plastic and defines a third concave aspheric surface on the object side and a fourth convex aspheric surface. The third lens element is made of an optical plastic and defines a fifth high-aperture size convex aspheric surface on the object side and a sixth wave-shaped aspheric surface. Each of the lens elements is symmetrically disposed about an optical axis of the lens. The lens is compact and capable of covering total field angle of up to about 70 degrees.