Folded Macro-Tele Lens Layout for Close-Range Smartphone Imaging

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing smartphone cameras struggle with capturing high-quality macro images from short object-lens distances due to limited object-to-image magnification and poor optical Bokeh effects, especially when focusing on objects close to the camera.

Innovation Solution

A folded digital camera design with a lens system comprising N≥6 lens elements, featuring a focusing range from infinity to a minimal object distance (MIOD) with a magnification ratio of 1:1-15:1 and a high degree of optical Bokeh, achieved through a lens system with specific optical properties and a focusing mechanism.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a conventional lens system is used in smartphone cameras, then the device structure remains simple, but the object-to-image magnification is limited and optical Bokeh effects are poor when focusing on close objects

Engineering Contradiction:

Improveobject-to-image magnificationVSAvoidlens system structure

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The lens system is divided into multiple lens elements (at least six elements) with specific refractive power configurations (++-+−+ or +−++−+). This segmentation allows each element to contribute to different aspects of optical performance, achieving high magnification and Bokeh effects while managing the overall complexity through modular design

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent employs a folded optical path design where the optical trajectory is folded back within the device, enabling a compact lens system that achieves macro magnification capabilities in a space-constrained smartphone environment. The optical elements are nested within a folded configuration that maximizes the optical path length while minimizing the physical footprint

Inventive Principle:

Principle #7Nested doll (Nesting)

2Adaptability or versatility

If the camera focuses on objects at short distances (5-15 cm), then macro imaging capability is achieved, but field curvature increases and image quality deteriorates

Engineering Contradiction:

Improveminimal object distance focusingVSAvoidfield curvature control

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

Different lens elements are assigned specific refractive powers and positions to address local optical issues. The configuration ++-+−+ or +−++−+ ensures that each element contributes to correcting field curvature at close focusing distances, with elements positioned and powered to optimize performance at the minimal object distance while maintaining overall image quality

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The lens system utilizes precise control of refractive indices, curvatures, and spacing between elements to dynamically adjust optical parameters for close-distance focusing. The design allows the system to maintain low field curvature when focusing at 5-15 cm by optimizing the combination of positive and negative power elements

Inventive Principle:

Principle #35Parameter changes

3Volume of moving object

If the optical path is folded to reduce device size, then the camera becomes more compact, but the optical path length and complexity increase

Engineering Contradiction:

Improvedevice sizeVSAvoidoptical path length

Core Design Contradiction:

Volume of moving objectVSLength of stationary object

Solution Approach 1:

The optical path is folded in multiple dimensions within the device, creating a compact configuration where light travels through a longer optical path while the physical device dimensions remain small. This dimensional folding allows macro magnification capability in a space-constrained smartphone environment by maximizing the optical path length without increasing the device footprint

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 camera system enables high-quality macro imaging with improved object-to-image magnification and optical Bokeh, allowing for clear and well-focused images from 5-15 cm object-lens distances with minimal field curvature and low light loss.

Implementation Method 1

a lens system with N≥6 lens elements Li, having an EFL and a TTL, wherein each lens element has a respective focal length fi

Methodology Applied

Scientific EffectRefraction: Refraction

Data Source

PatentUS12399351B2Folded macro-tele camera lens designs including six lenses of ++−+−+ or +−++−+, seven lenses of ++−++−+, or eight lenses of ++−++−++ refractive powers

Publication Date: 2025.08.26 COREPHOTONICS

AI summary

Folded digital cameras comprising a lens system with a lens and an image sensor, the lens having N≥6 lens elements Li, an effective focal length (EFL) and a total track length (TTL), wherein each lens element has a respective focal length fi and wherein a first lens element L1 faces an object side, and an optical path folding element (OPFE) for providing a folded optical path between an object and the lens. In some embodiments, the lens system has a focusing range that covers object-lens distances from infinity to a minimal object distance (MIOD), wherein MIOD/EFL is smaller than 20 or even 7. In some embodiments, the ratio of a maximal chief ray angle to a field of view of the folded camera Max CRA/FOV is smaller than 0.25 or even 0.15 when the camera is focused at infinity.