Five-Element Telephoto Lens System Miniaturization

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Solution Overview

Problem

Conventional photographing lens systems struggle to achieve a balance between high specification and miniaturization, particularly in meeting the requirements for large apertures, telephoto features, and compact size, while also facing challenges with optical zoom and image quality.

Innovation Solution

A photographing optical lens system comprising five lens elements, each with specific refractive powers and surface curvatures, is designed to address the miniaturization and performance challenges. The system includes a first lens element with positive refractive power, a second lens element with negative refractive power, and a fifth lens element with negative refractive power, along with specific curvature radii and axial distances to optimize image quality and compactness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional photographing lens systems are designed with telephoto features and large apertures, then optical performance is improved, but total track length increases and device size becomes larger

Engineering Contradiction:
Improveoptical performanceVSAvoidtotal track length
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

The lens system is divided into five distinct lens elements with specific positive and negative refractive powers, allowing complex optical functions to be distributed across multiple components. This segmentation enables achieving telephoto optical performance while keeping each individual element compact, thereby reducing the total track length compared to conventional single-element or fewer-element designs.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The five lens elements are arranged in a nested configuration where elements with negative refractive power are positioned between elements with positive refractive power. This nesting strategy allows the optical path to be folded back on itself, effectively reducing the axial length (total track length) while maintaining the telephoto focal length and large aperture characteristics.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Length of stationary object

If photographing lens systems are miniaturized to reduce device size, then device compactness is improved, but achieving large apertures and telephoto features becomes difficult

Engineering Contradiction:
Improvedevice sizeVSAvoidoptical zoom capability
Core Design Contradiction:
Length of stationary objectVSAdaptability or versatility

Solution Approach 1:

The patent employs specific parameter relationships between the five lens elements, including precise control of curvature radii (R1-R10), axial distances (Td, BL, Dr7r10), and refractive powers. By optimizing these parameters, the system achieves a compact form factor while maintaining telephoto optical characteristics and large aperture capability, effectively decoupling device size from optical zoom performance.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If more lens elements are added to improve image quality and optical performance, then image quality is improved, but device complexity and size increase

Engineering Contradiction:
Improveimage qualityVSAvoidlens system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Each of the five lens elements is designed with specific local optical properties, including designated convex and concave surfaces with particular curvature radii. The first, third, and fifth elements have positive refractive power with specific surface configurations, while the second and fourth elements have negative refractive power. This localized optimization of quality in each element contributes to overall superior image quality while maintaining manageable system complexity through clear functional differentiation.

Inventive Principle:
Principle #3Local 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

The proposed lens system achieves improved image quality, miniaturization, and flexibility in design, enabling it to meet the demands for high specification and compact size while maintaining effective optical performance.

Implementation Method 1

The first lens element has positive refractive power, and the object-side surface of the first lens element is convex in a paraxial region thereof. The image-side surface of the first lens element is convex in a paraxial region thereof

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP4099073B1Photographing optical lens system, imaging apparatus and electronic device
Publication Date: 2025.06.11 LARGAN PRECISION
  • EP4099073B1 patent drawingFigure 1A
  • EP4099073B1 patent drawingFigure 1B
  • EP4099073B1 patent drawingFigure 2A

AI summary

A photographing optical lens system includes five lens elements being, in order from an object side to an image side along an optical path, a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element. Each lens element has an object-side surface facing the object side and an image-side surface facing the image side. The first lens element has positive refractive power and the object-side surface being convex in a paraxial region thereof. The image-side surface of the third lens element is convex in a paraxial region thereof. The object-side surface of the fourth lens element is convex in a paraxial region thereof. The fifth lens element has negative refractive power, the object-side surface being convex, and the image-side surface being concave in a paraxial region thereof.