Four-Lens Optical System for Wide-Angle Imaging Without IR Cut Filter
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional optical image capturing systems for portable electronic devices face challenges in balancing high pixel count, image quality, and miniaturization, particularly in achieving a wide angle of view and low distortion, while also effectively handling both visible and infrared light spectra without the need for bulky and expensive IR Cut filters.
Innovation Solution
The use of a four-piece optical lens system with convex and concave surfaces, optimized refractive powers, and specific material selection to minimize focal length differences between visible and infrared light, allowing for a compact design that captures high-quality images across a wide angle of view without requiring an IR Cut filter, by adjusting the angle of incidence and correcting optical distortions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a large aperture design is used to increase light admission, then the quantity of admitted light is improved, but aberration increases resulting in deterioration of image quality and manufacturing difficulties
Solution Approach 1:
The optical system is divided into four separate lens elements (first lens L1, second lens L2, third lens L3, fourth lens L4) with alternating positive and negative refractive powers. This segmentation allows each element to contribute differently to light gathering while correcting aberrations introduced by others, achieving large aperture without quality loss.
Solution Approach 2:
Different regions of the optical system are assigned different functional characteristics. The first lens has positive refractive power for light convergence, the second has negative for divergence and aberration correction, the third has positive for focusing, and the fourth has negative for final aberration correction. This local differentiation enables simultaneous optimization of light admission and image quality.
2Adaptability or versatility
If a wide angle of view design is used to increase viewing angle, then the angle of view is improved, but distortion rate increases resulting in deterioration of image quality
Solution Approach 1:
The wide angle of view requirement is achieved through segmentation into four lens elements with alternating refractive powers. The negative refractive power elements (L2, L4) specifically counteract the distortion introduced by positive elements (L1, L3) and the wide angle configuration, enabling distortion-free wide-angle imaging.
Solution Approach 2:
The optical system employs asymmetric configuration with alternating positive and negative refractive power elements rather than symmetric design. This asymmetric arrangement with specific focal length ratios enables correction of wide-angle distortion while maintaining the desired wide field of view.
3Manufacturing precision
If an IR Cut filter is added to filter infrared light, then image fidelity is improved, but device complexity and cost increase
Solution Approach 1:
The patent removes the IR Cut filter from the optical system entirely. Instead of adding a filtering component, the system relies on the inherent spectral characteristics of the image sensor and the optical properties of the four-lens system to achieve the desired visible light imaging performance without infrared interference.
Solution Approach 2:
The four-lens optical system serves multiple functions simultaneously: it provides wide-angle imaging, corrects aberrations, and inherently manages spectral characteristics without requiring separate IR filtering components. The alternating positive-negative refractive power configuration creates a multi-functional system that eliminates the need for additional specialized elements.
4Volume of moving object
If miniaturization is pursued to reduce device size, then device compactness is improved, but optical performance deteriorates
Solution Approach 1:
The patent employs dynamic optimization of the optical path by using alternating positive and negative refractive power elements that can effectively fold and compress the light path. This dynamic configuration allows the optical system to achieve long effective focal length and high optical performance within a compact physical footprint suitable for portable devices.
Solution Approach 2:
The optical system utilizes clever spatial arrangement in multiple dimensions, with lens elements positioned at specific distances from each other along the optical axis. The alternating refractive power configuration creates an efficient three-dimensional layout that maximizes optical performance while minimizing the overall device volume for portable application.
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 enhances image quality and pixel count, reduces system size, and eliminates the need for IR Cut filters, enabling efficient capture of both visible and infrared light spectra within a compact and cost-effective optical image capturing system.
Implementation Method 1
Optical image capturing system, in sequence from an object side to an image side, includes a first lens, a second lens, a third lens, and a fourth lens, each having a refractive power
Implementation Method 2
the convex or concave surface in the disclosure denotes the geometrical shape of an image-side surface or an object-side surface of each lens on an optical axis
Data Source
AI summary
The invention discloses a four-piece optical lens for capturing image and a four-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 refractive power; a second lens with refractive power; a third lens with refractive power; and a fourth lens with refractive power; and at least one of the image-side surface and object-side surface of each of the four lenses are aspheric. The optical lens may increase aperture value and improve the imagining quality for use in compact cameras.