Segmented Illumination Lens for Optical Code Readers

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Optical code readers of the imager type face challenges in achieving uniform illumination of optical codes due to non-uniformities caused by light source emission characteristics and sensor response variations, leading to inefficient reading results and poorly defined illumination lines.

Innovation Solution

The use of an illumination lens with a first main face featuring a plurality of elementary regions, each with individually calculated slopes to deviate light fractions and create a predetermined illumination pattern, ensuring uniform irradiance and reducing non-uniformities, while allowing for adjustable slopes and densities to optimize the irradiance profile.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If conventional illumination optics with local repetitions of microstructures are used, then uniformity of illumination line is improved, but overall efficiency of the reader is reduced

Engineering Contradiction:

Improveuniformity of illumination lineVSAvoidoverall efficiency of the reader

Core Design Contradiction:

Illumination intensityVSLoss of energy

Solution Approach 1:

The illumination lens is divided into multiple elementary regions, each with individually calculated slopes to deviate light fractions toward specific elementary regions of the illumination pattern. This segmentation allows precise control of light distribution to achieve uniform illumination while minimizing energy waste.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Each elementary region of the illumination lens has a locally optimized slope calculated to direct light to a specific target region. This local quality approach ensures that each part of the lens contributes efficiently to the overall uniform illumination pattern, avoiding over-illumination and energy loss.

Inventive Principle:

Principle #3Local quality

2Illumination intensity

If conventional illumination optics are used, then emission lobes of light sources can be overlapped to improve uniformity, but area illuminated is much larger than area actually framed by receiving optics

Engineering Contradiction:

Improveuniformity of illumination lineVSAvoidarea illuminated

Core Design Contradiction:

Illumination intensityVSArea of stationary object

Solution Approach 1:

The lens is segmented into elementary regions that map one-to-one with target regions in the illumination pattern. This ensures light is directed only where needed within the field of view, preventing illumination of areas outside the receiving optics' frame.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The slope parameter of each elementary lens region is individually calculated and optimized to control the angular distribution of deviated light. By adjusting these parameters, the illumination is precisely confined to the desired area while maintaining uniformity.

Inventive Principle:

Principle #35Parameter changes

3Shape

If conventional illumination optics are used, then illumination pattern can be generated, but side edges of illumination line are poorly defined

Engineering Contradiction:

Improveillumination patternVSAvoiddefinition of side edges

Core Design Contradiction:

ShapeVSManufacturing precision

Solution Approach 1:

The lens is divided into elementary regions including edge regions with specifically calculated slopes. This segmentation allows precise control of light direction at the boundaries, creating well-defined side edges in the illumination pattern.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Edge regions of the lens have locally optimized slope values that differ from central regions. This local quality optimization ensures that light is precisely directed at the boundaries of the illumination pattern, creating sharp, well-defined edges.

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

This solution enhances the uniformity of the illumination pattern, improves reading efficiency, and provides clear indication of the reading area boundaries, maximizing optical efficiency by illuminating only the field of view of the receiving optics.

Implementation Method 1

each of the elementary regions of the at least one illumination lens having a slope with respect to an optical axis of the reader that is individually calculated so that the elementary region deviates the light fraction coming from the at least one light source and incident thereon towards a specific elementary region of the illumination pattern

Methodology Applied

Scientific EffectRefraction: Refraction

Data Source

PatentUS8113430B2Illumination lens for optical code reader

Publication Date: 2012.02.14 DATALOGIC SCANNING GROUP

AI summary

An optical code reader of the imager type includes at least one light source and at least one illumination lens downstream of the at least one light source for projecting a predetermined illumination pattern. The at least one illumination lens comprises a first main face, wherein in a first direction, the first main face has a plurality of elementary regions, each of the elementary regions of the at least one illumination lens having a slope with respect to an optical axis of the reader that is individually calculated so that the elementary region deviates the light fraction coming from the at least one light source and incident thereon towards a specific elementary region of the illumination pattern.