Three-Lens Optical System for Compact Cameras
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Solution Overview
Problem
Conventional optical systems for portable electronic devices face challenges in achieving high imaging quality due to aberrations and distortion, especially in low-light conditions and wide view angles, while also requiring miniaturization and compatibility with both visible and infrared light spectra without the use of expensive IR cut filters.
Innovation Solution
The optical image capturing system employs a combination of refractive powers and convex/concave surfaces in three or four lenses, optimized lens parameters, and material selection to achieve a near-confocal effect between visible and infrared light focal lengths, reducing the need for IR cut filters and enhancing imaging quality across various light conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the aperture is increased to allow more light entering the lens, then the amount of light entering the lens is improved, but aberrations are generated causing poor imaging quality at peripheral portions
Solution Approach 1:
The optical system is divided into multiple lenses (first lens, second lens, third lens, and optionally fourth lens) with different refractive powers and surface curvatures. Each lens segment handles specific portions of the light path, with the first lens having positive refractive power for light gathering, the second lens with negative refractive power for aberration correction, and subsequent lenses for fine-tuning image quality across the entire field of view.
Solution Approach 2:
Different lenses are designed with specific local properties: the first lens has a convex object-side surface for light gathering, the second lens has concave surfaces for aberration correction, and the third and fourth lenses have optimized curvatures for peripheral image quality. Each lens element is tailored to address specific optical challenges in its local region of the optical path.
2Adaptability or versatility
If the view angle is widened to provide wide view for selfies, then the view angle is improved, but distortion is increased causing poor imaging quality
Solution Approach 1:
The optical system uses multiple lens elements (four lenses in the preferred embodiment) where each lens contributes to different aspects of the wide-angle performance. The first lens establishes the wide field of view, while the second, third, and fourth lenses progressively correct distortion and maintain image quality across the expanded angular range.
Solution Approach 2:
The patent optimizes specific parameter ranges including the focal lengths of individual lenses (f1, f2, f3, f4), the ratios of focal lengths to entrance pupil diameter (f/HEP), and the distances between lens elements (IN12, IN23, IN34). These parameter optimizations enable wide view angle while controlling distortion through precise mathematical relationships between lens properties.
3Volume of moving object
If the optical system is miniaturized to fit portable electronic devices, then the system size is reduced, but the ability to capture high-quality images in low-light conditions deteriorates
Solution Approach 1:
The optical system packs multiple lens elements (first, second, third, and fourth lenses) into a compact arrangement where each lens is positioned closely to the others along the optical axis. The total optical path length is minimized while maintaining functional separation between lenses, achieving a miniaturized design that fits within portable device constraints.
Solution Approach 2:
The patent optimizes the ratio of total optical path length to focal length (HOS/f) to be within 1.0 to 3.0, and the ratio of image height to optical path length (HOI/HOS) to be within 0.2 to 0.5. These parameter constraints enable miniaturization while preserving light-gathering capability through efficient optical path design.
4Manufacturing precision
If IR cut filters are used to filter infrared light for visible light imaging, then color fidelity is improved, but system cost and complexity increase
Solution Approach 1:
The patent removes the IR cut filter from the optical system entirely. Instead of using a filter to block infrared light, the system relies on the natural properties of the lens materials and the image sensor to handle both visible and infrared wavelengths, eliminating the need for additional filtering components.
Solution Approach 2:
The optical lens system is designed to universally handle both visible light (400-700nm) and infrared light (700nm-1μm) wavelengths without requiring wavelength-specific filtering. The lens materials and surface curvatures are optimized to provide acceptable imaging performance across this broad spectral range, making the system multi-functional for different lighting conditions.
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 improves light intake, widens the view angle, increases pixel density, and maintains high image quality, while minimizing system size and eliminating the need for expensive IR cut filters, thus addressing the limitations of conventional systems.
Implementation Method 1
The optical image capturing system includes a first lens, a second lens, and a third lens from an object side to an image side... combination of refractive powers, convex and concave surfaces of three-piece optical lenses
Data Source
AI summary
The invention discloses a three-piece optical lens for capturing image and a three-piece optical module for capturing image. In order from an object side to an image side, the optical lens along the optical axis comprises a first lens with positive refractive power; a second lens with refractive power; and a third lens with refractive power; and at least one of the image-side surface and object-side surface of each of the three lenses are aspheric. The optical lens can increase aperture value and improve the imagining quality for use in compact cameras.