Folded Optical Imaging System for Compact Telephoto Lenses
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Solution Overview
Problem
The challenge in developing optical imaging systems for portable terminals is the increase in thickness due to the diameters of multiple lenses, which is undesirable for miniaturization, especially when implementing telephoto properties without increasing the device's size.
Innovation Solution
An optical imaging system with a reflective member and two lens groups, where the first lens group has positive refractive power and is disposed on the front side of the reflective member, and the second lens group has a plurality of lenses, with specific optical configurations and rotational axes to maintain a compact size while achieving telephoto capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple lenses are used to implement telephoto properties, then telephoto capability is improved, but thickness of the portable terminal increases
Solution Approach 1:
The patent introduces a reflective member (prism) that redirects light at a 90-degree angle, changing the optical path from a linear arrangement to a folded configuration. This allows the optical axis to extend in a direction perpendicular to the thickness direction of the terminal, achieving telephoto capability without increasing the device's thickness dimension.
Solution Approach 2:
The reflective member is positioned within the housing of the portable terminal, and the optical path is folded back into the device's internal volume. The lens groups are arranged such that light reflects off the prism and returns through the same opening, effectively nesting the optical path within the device's thickness envelope.
2Measurement precision
If diameters of multiple lenses are increased to improve image quality, then image resolution is improved, but thickness of the portable terminal increases
Solution Approach 1:
By folding the optical path using the reflective member, the patent allows larger lens diameters to be used without proportionally increasing device thickness. The optical components are arranged in a compact folded configuration that maintains large aperture lenses while controlling the overall device thickness.
3Length of stationary object
If a reflective member is disposed on the front side of lenses to reduce thickness, then device thickness is reduced, but device complexity increases
Solution Approach 1:
The reflective member acts as an intermediary optical element that simplifies the overall system architecture by folding the optical path. While it adds one component, it eliminates the need for multiple separate lens groups arranged linearly, and the prism can be integrated into the housing structure, reducing mechanical complexity.
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 a reduced size and improved image brightness while maintaining telephoto performance, allowing for efficient use in portable devices without significantly increasing thickness.
Implementation Method 1
a reflective member having a reflective surface for changing a path of light
Implementation Method 2
a first lens group, disposed on a front side of the reflective member, comprising one or more lenses; and a second lens group, disposed on a rear side of the reflective member, comprising a plurality of lenses. Each of the first lens group and the second lens group has positive refractive power
Data Source
AI summary
An optical imaging system includes a reflective member having a reflective surface for changing a path of light; a first lens group, disposed on a front side of the reflective member, comprising one or more lenses; and a second lens group, disposed on a rear side of the reflective member, comprising a plurality of lenses. Each of the first lens group and the second lens group has positive refractive power. An object-side surface of a frontmost lens disposed closest to an object side, among the one or more lenses of the first lens group, is convex. 0.5<fG1/fG2<2.5 is satisfied, where fG1 is a focal length of the first lens group, and fG2 is a focal length of the second lens group.