Seven-Lens Cemented Optics for Slim High-Resolution Imaging
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Solution Overview
Problem
The challenge is to develop an optical imaging system for mobile devices that maintains high resolution while ensuring a slim size, as larger image sensors increase the total optical length, leading to performance degradation.
Innovation Solution
An optical imaging system comprising seven lenses, including cemented lenses with specific refractive powers and surface configurations, satisfies conditional expressions for focal lengths and Abbe numbers to minimize chromatic aberration and achieve high resolution within a compact form factor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the image sensor size is increased to improve resolution, then the total optical length is increased, but the device size increases leading to performance degradation
Solution Approach 1:
The optical system is divided into multiple lens elements (first lens through seventh lens) with different refractive powers arranged in sequence. Each lens segment contributes to correcting specific aberrations, allowing the system to achieve high resolution with a compact total optical length by distributing the optical function across multiple smaller elements rather than requiring a single large lens or longer optical path.
Solution Approach 2:
The patent employs conditional expressions to precisely control the refractive powers and Abbe numbers of the lens elements. By optimizing parameters such as the ratio of refractive powers (fa/Va - fb/Vb) and selecting specific Abbe number ranges, the system achieves effective chromatic aberration correction within a compact form factor, resolving the contradiction between resolution and device size.
2Volume of moving object
If the total optical length is reduced to achieve slim size, then the device becomes more compact, but chromatic aberration increases degrading image quality
Solution Approach 1:
Different lens elements are assigned specific local functions with optimized properties. The first lens has positive refractive power with specific Abbe number range, the second lens has negative refractive power with complementary properties, and subsequent lenses are designed with specific curvature and refractive index characteristics. This local optimization of optical properties allows each element to contribute to chromatic aberration correction in its specific position within the compact optical path.
Solution Approach 2:
The optical system uses a composite lens structure combining multiple lens materials with different refractive indices and Abbe numbers. The cemented lens combining first and second lenses with opposite refractive powers creates a composite optical element that effectively corrects chromatic aberration. This material composition allows the system to achieve high-resolution imaging with reduced optical length by leveraging the complementary optical properties of different materials.
3Measurement precision
If cemented lenses with opposite refractive powers are used to correct chromatic aberration, then image quality improves, but manufacturing complexity increases
Solution Approach 1:
The first and second lenses with opposite refractive powers are cemented together to form a single optical unit. This merging of two lens elements with complementary properties (positive and negative refractive powers) into one cemented lens structure simplifies the overall optical path while maintaining the chromatic aberration correction benefits. The cemented lens acts as a unified optical element that can be manufactured and assembled more efficiently than separate air-spaced lenses would require.
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 system achieves high-resolution imaging with reduced size and improved brightness performance, minimizing chromatic aberration and maintaining optical performance in a slim form factor.
Implementation Method 1
a first lens having positive refractive power, a second lens having negative refractive power, a third lens having positive refractive power, a fourth lens having negative refractive power, a fifth lens having refractive power, a sixth lens having positive refractive power, and a seventh lens having negative refractive power
Implementation Method 2
satisfies conditional expressions for focal lengths and Abbe numbers to minimize chromatic aberration
Data Source
AI summary
An optical imaging system is provided. The optical imaging system includes a first lens having positive refractive power, a second lens having negative refractive power, a third lens having positive refractive power, a fourth lens having negative refractive power, a fifth lens having refractive power, a sixth lens having positive refractive power and a seventh lens having negative refractive power, wherein the first lens to the seventh lens are disposed in order from an object side, wherein the first lens to the seventh lens include a cemented lens that is formed by bonding adjacent surfaces of two lenses, disposed adjacently, to each other, and wherein the two lenses that form the cemented lens have opposite refractive powers.