Folded Optical Path Meniscus Lens for Smartphone Portraiture
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Solution Overview
Problem
Smartphone cameras are optically limited due to space constraints, limiting their ability to achieve high image quality and versatility in portraiture photography, despite advancements in image resolution and autofocus features.
Innovation Solution
A lens configuration using first and second meniscus lenses with reflective surfaces and a negatively powered third lens, allowing for internal reflections and adjustable focusing over a wide range of object distances, enabling improved image quality and depth of field control within a compact form factor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a longer focal length is used to improve portraiture image quality, then image quality improves, but the device size increases beyond compact constraints
Solution Approach 1:
The patent implements a folded optical path where light reflects off a mirror to traverse the optical axis multiple times within a compact volume. This nesting of the optical path allows a longer effective focal length to be achieved within a shorter physical device length, resolving the contradiction between image quality and device size.
Solution Approach 2:
The patent transitions from a linear optical path to a folded three-dimensional path by introducing a mirror at an angle to the optical axis. This dimensional change allows light to travel a longer distance through the lens system without increasing the linear dimensions of the device, enabling improved image quality within compact constraints.
2Length of stationary object
If the optical path is folded to provide longer focal lengths, then focal length increases, but the device complexity increases
Solution Approach 1:
The patent employs a single mirror element that serves multiple functions: it folds the optical path to achieve longer focal length, defines the field of view through its angular positioning, and enables compact packaging. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in device complexity.
3Volume of moving object
If a compact lens system is used to maintain small form factor, then device size decreases, but image quality and depth of field control deteriorate
Solution Approach 1:
The folded optical path nested within the compact housing allows the lens system to achieve an effective focal length and optical performance comparable to larger systems. By nesting the light path through reflections, the system maintains small form factor while preserving image quality and depth of field control.
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 lens configuration enhances the image quality and depth of field control for portraiture photography, allowing focus adjustment from 500 mm to infinity, providing a suitable solution for the optical limitations of smartphone cameras while maintaining a compact design.
Implementation Method 1
The first lens includes an anterior concave surface having a reflective material extending over a portion thereof so that light received by the first meniscus lens from the object can be transmitted through the first lens. The reflective material is positioned along the anterior concave surface to receive light which has been transmitted through the first lens and reflected back from the second meniscus lens.
Implementation Method 2
The meniscus lenses are aligned along an optical axis for transmitting light from an object along a path toward a focal plane.
Implementation Method 3
The third lens may be a negatively powered lens or group of lenses serving to adjust focus of light or change image size along the focal plane.
Data Source
AI summary
A portrait lens configuration for meeting handheld device form factor constraints. First and second meniscus lenses each have a reflective surface to provide internal reflections for transmitting light toward a focal plane. A third lens is positioned between the meniscus lenses and the focal plane. The first lens includes an anterior concave surface having a reflective material extending over a portion thereof. Light received by the first meniscus lens can be transmitted therethrough. The reflective material is positioned along the anterior concave surface to receive light transmitted therethrough and reflected back from the second lens. In an associated method the first meniscus lens is positioned to receive light through a first of two opposing refractive surfaces. After each lens provides an internal reflection, reflected light is transmitted through the second of the two opposing surfaces and then through a bore positioned within the second lens to the third lens.