Thin Profile Lens for Flashlight Beam Control

Solution Overview

Problem

Conventional flashlight lenses struggle to combine maximum intensity for a spot beam with substantial uniformity for a wide beam, often requiring complex shapes and central convex surfaces for proper focusing, which can limit their efficiency and manufacturing simplicity.

Innovation Solution

A thin-profile lens system with a concave, flat, or convex rear surface, combined with an adjustable bezel, allows for independent curvature of central and annular ring portions, enabling efficient light transfer and beam adjustment from flood to spot without a rear void for the light source, using materials like glass or polymethyl methacrylate for the lens and bezel.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional lenses use central convex surfaces and additional convex surfaces for focusing, then proper light focusing is achieved, but device complexity and manufacturing complexity increase

Engineering Contradiction:

Improvelight focusing capabilityVSAvoidlens shape complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The lens is divided into two distinct functional zones: a central portion with a first curvature and an annular ring portion surrounding it with a second curvature. This segmentation allows each zone to independently optimize light focusing for different beam types, achieving both spot and flood beam capabilities without requiring complex additional surfaces.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different portions of the lens are assigned different optical properties: the central portion has a specific curvature optimized for spot beams, while the annular ring portion has a different curvature optimized for flood beams. This local differentiation enables the single lens surface to perform multiple focusing functions that previously required complex multi-surface designs.

Inventive Principle:

Principle #3Local quality

2Adaptability or versatility

If conventional lenses combine maximum intensity for spot beam with uniformity for wide beam, then beam versatility is improved, but manufacturing simplicity deteriorates

Engineering Contradiction:

Improvebeam type versatilityVSAvoidlens manufacturing simplicity

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The lens is divided into two distinct functional zones: a central portion with a first curvature and an annular ring portion surrounding it with a second curvature. This segmentation allows each zone to independently optimize light focusing for different beam types, achieving both spot and flood beam capabilities without requiring complex additional surfaces.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different portions of the lens are assigned different optical properties: the central portion has a specific curvature optimized for spot beams, while the annular ring portion has a different curvature optimized for flood beams. This local differentiation enables the single lens surface to perform multiple focusing functions that previously required complex multi-surface designs.

Inventive Principle:

Principle #3Local quality

3Adaptability or versatility

If conventional lenses include a rear void for light source adjustment, then beam focus adjustment is enabled, but lens profile thickness increases

Engineering Contradiction:

Improvebeam focus adjustabilityVSAvoidlens profile thickness

Core Design Contradiction:

Adaptability or versatilityVSLength of moving object

Solution Approach 1:

The patent incorporates an adjustable bezel mechanism that allows dynamic repositioning of the light source along the optical axis. This enables the user to adjust the beam focus between spot and flood modes by moving the light source closer to or farther from the lens, respectively, without requiring a fixed rear void that would increase lens thickness.

Inventive Principle:

Principle #15Dynamics

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 thin-profile lens system achieves efficient light transfer and beam adjustment, allowing a lower-powered light source to produce equivalent or greater brightness with improved beam control and reduced complexity in manufacturing.

Implementation Method 1

The lens may be configured to refract and/or reflect light from the light source

Methodology Applied

Scientific EffectRefraction: Refraction

Implementation Method 2

The lens may be configured to refract and/or reflect light from the light source

Methodology Applied

Scientific EffectReflection: Reflection

Data Source

PatentEP2861906B1Thin profile lens for flashlight

Publication Date: 2018.03.21 COAST CUTLERY CO

Figure 1A~1C
Figure 2A~2C
Figure 3A~3B

AI summary

The present disclosure relates to a thin-profile lens for shaping a beam of light from a light source, such as a light emitting diode (LED), for example in a flashlight or other lighting unit. In various embodiments, the lens may be combined with an adjustment mechanism for varying the focus of the beam of light, and may be housed in a structure supporting the lens, light source, and adjustment mechanism. In various embodiments, the structure also may include a power source, controls, interconnections, and electronics. In various embodiments, the thin profile of the lens may allow the lens to be used in any of a number of applications, ranging from narrow diameter flashlights to large diameter light sources.