Zoom Lens Design for Compact Digital Cameras
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Solution Overview
Problem
Existing zoom lenses for compact digital cameras face challenges in achieving high zoom ratios and wide-angle arrangements while maintaining image quality and compact size, as they often require longer lens systems and insufficient optical performance.
Innovation Solution
A zoom lens design with specific refracting power and lens group arrangements, including a positive lens on the imaging device side, an aperture stop, and additional lens groups, optimized to balance light incidence angles and pixel pitch, ensuring high zoom ratios and minimized field curvature and size, using conditions such as |αt−αw|>8, 1.0×10−3<P<4.0×10−3, and 4<ft/fw<50.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a zoom lens system is designed to achieve high zoom ratios and wide-angle arrangements, then the taking range is widened, but the lens system length increases and compact size is lost
Solution Approach 1:
The zoom lens is divided into multiple lens groups (first lens group with positive refracting power, second lens group with negative refracting power, third lens group with positive refracting power, and fourth lens group with positive refracting power) that can move independently relative to each other. This segmentation allows the lens system to achieve high zoom ratios and wide-angle arrangements while maintaining a compact overall length by optimizing the arrangement and movement of each segment.
2Adaptability or versatility
If the lens system is made more powerful to achieve high zoom ratios, then the taking range is widened, but the optical performance deteriorates due to production errors and assembly sensitivity
Solution Approach 1:
Each lens group is designed with specific refracting powers and optical characteristics tailored to its function in the zoom range. The first lens group provides wide-angle coverage, the second group enables zooming, the third group maintains optical performance, and the fourth group optimizes image quality. This local optimization of quality in each segment reduces sensitivity to production errors and assembly variations while achieving high zoom ratios.
3Reliability
If the angle of incidence of rays on the imaging device is kept small across all zoom ranges, then imaging capability is maintained, but the tradeoff between imaging quality and size reduction is lost
Solution Approach 1:
The lens groups are designed to move dynamically relative to each other during zooming operations, allowing the optical system to adapt the angle of incidence of rays on the imaging device according to the zoom ratio. This dynamic adjustment maintains imaging capability across all zoom ranges while enabling compact camera size by optimizing the optical path at each zoom position.
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 design achieves a balance between high zoom ratios, wide-angle capabilities, and compact size, maintaining image quality and reducing fluctuations in field curvature, allowing for smaller camera designs without compromising image quality.
Implementation Method 1
a first lens group having positive refracting power, a second lens group having negative refracting power, an aperture stop, a third lens group having positive refracting power and a fourth lens group having positive refracting power
Data Source
AI summary
An electronic imaging apparatus comprises a zoom lens including at least two lens groups and adapted to implement zooming by changing the spacing between the respective lens groups, and an electronic imaging device. The zoom lens includes at least one positive lens on an imaging device side with respect to an aperture stop, and satisfies the following conditions (1), (2) and (3).|αt−αw|>8 (1)1.0×10−3<P<4.0×10−3 (2)4<ft/fw<50 (3).