Zoom Lens System with Folded Optical Path for Compact Design
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Solution Overview
Problem
Current digital cameras face challenges in achieving a slim design due to the thickness of the optical system, particularly the zoom lens, which hinders further reduction in depth and overall compactness, especially when requiring a zoom ratio of at least 3 and a compact front lens barrel.
Innovation Solution
The electronic imaging apparatus incorporates a zoom optical system with a first lens unit having a single biconcave negative lens element and a positive lens component, where the lens components are configured to minimize thickness and diameter, and an image processing section corrects distortion, allowing for a more compact design while maintaining image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional zoom lens system is used to achieve a zoom ratio of at least 3, then the imaging function is improved, but the thickness and overall depth of the optical system increases
Solution Approach 1:
The patent introduces a mirror to bend the optical path, changing the light propagation from a straight linear path to a folded three-dimensional path. This allows the optical system to achieve a high zoom ratio while maintaining a compact thickness by utilizing the depth direction for optical path lengthening rather than increasing front-to-back thickness.
Solution Approach 2:
The optical system is arranged in a nested configuration where lens units are positioned at different depths and the mirror folds the light path within the available space. The first lens unit, mirror, and second lens unit are arranged to create a compact nested structure that achieves high zoom ratio without proportionally increasing overall thickness.
2Length of stationary object
If the optical path is bent using a mirror to reduce depth, then the compactness is improved, but the complexity of the optical system increases
Solution Approach 1:
The optical system is divided into distinct functional segments: a first lens unit with negative refracting power, a mirror for path bending, and a second lens unit with positive refracting power. This segmentation allows each component to perform its specific function efficiently while keeping the overall design manageable and not excessively complex.
3Area of stationary object
If the front lens diameter is reduced to make the lens barrel compact, then the overall compactness is improved, but the imaging quality and aberration correction becomes more difficult
Solution Approach 1:
The patent replaces traditional mechanical aberration correction methods (requiring larger diameters and complex lens arrangements) with an image processing approach. The image processing section electrically processes the image data to correct distortion and aberrations, allowing for a compact front lens diameter while maintaining imaging quality.
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 configuration effectively reduces the lens system's thickness and diameter, enabling a higher zoom ratio and improved compactness while effectively correcting off-axis chromatic aberration and coma, thereby enhancing the camera's overall performance and image quality.
Implementation Method 1
a first lens unit with negative refracting power and a second lens unit with positive refracting power
Implementation Method 2
an image processing section electrically processing image data obtained by the electronic image sensor to change the shape thereof
Data Source
AI summary
An electronic imaging apparatus includes a zoom optical system having, in order from the object side, a first lens unit with negative power and a second lens unit with positive power, in which lens components having refracting power in the first lens unit are only a single biconcave negative lens element located at the most object-side position and a positive lens component located at the most image-side position; an electronic image sensor placed on the image side of the zoom optical system; and an image processing section electrically processing image data obtained by the electronic image sensor to change the shape thereof. The zoom lens system satisfies the following conditions in focusing of a nearly infinite object point:0.85<|y07/(fw·tan ω07w)|<0.970.75<|y10/(fw·tan ω10w)|<0.93where fw is the focal length of the entire zoom optical system at a wide-angle position, y10 is a distance from the center of an effective imaging surface of the electronic image sensor to a point furthest from the center, y07 is an image height expressed by 0.7 y10, and ω07w is an angle made by a direction of an object point corresponding to an image point, connecting the center of the effective imaging surface of the electronic image sensor at the wide-angle position and the position of the image height y07, with the optical axis.