Oblique LED Matrix for Paper Machine Web Imaging

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Solution Overview

Problem

In paper machine environments, existing lighting systems, such as halogen and metal halide lights, face issues with high power consumption, heat generation, and glare, which can lead to inefficient imaging and increased fire risks, especially when used for monitoring moving webs with oblique illumination angles.

Innovation Solution

A camera unit integrated with a customizable LED light matrix that uses high-efficiency LEDs with pulsing technology and varied beam optics to achieve optimal intensity distribution, reducing power consumption and heat while minimizing glare, with the ability to emit specific monochromatic light for improved imaging conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If halogen or metal halide lights are used for illuminating the web, then high illumination intensity is achieved, but power consumption and heat generation increase significantly

Engineering Contradiction:
Improveillumination intensityVSAvoidpower consumption
Core Design Contradiction:
Illumination intensityVSUse of energy by stationary object

Solution Approach 1:

The patent transitions from continuous illumination sources (halogen, metal halide) to pulsed LED illumination, fundamentally changing the operational parameters. LEDs are driven with current pulses synchronized to the camera shutter, providing sufficient illumination during the exposure period while consuming minimal power during non-pulse periods. This parameter change resolves the contradiction between achieving high illumination intensity and reducing power consumption.

Inventive Principle:
Principle #35Parameter changes

2Illumination intensity

If halogen or metal halide lights are used for illuminating the web, then high illumination intensity is achieved, but heat generation increases causing fire risks

Engineering Contradiction:
Improveillumination intensityVSAvoidfire risk
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The patent converts the inherent limitation of LEDs (lower continuous output compared to halogen) into an advantage by using pulsed operation. The brief pulses provide sufficient illumination for the camera exposure while the duty cycle remains low enough to prevent heat accumulation and fire risks. This transforms what could be seen as a limitation into a safety feature that eliminates fire hazards while maintaining imaging capability.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Ease of operation

If oblique illumination is used for imaging the web, then imaging equipment can be positioned outside the web, but light distribution becomes uneven with glare at close range and insufficient light at distance

Engineering Contradiction:
Improveimaging equipment positioningVSAvoidlight distribution uniformity
Core Design Contradiction:
Ease of operationVSIllumination intensity

Solution Approach 1:

The patent employs multiple LED modules positioned at different locations and angles relative to the web. Each LED module is configured to illuminate specific zones of the web, creating locally optimized illumination. The combined effect of multiple modules with different beam angles and positions achieves uniform light distribution across the entire imaging area, eliminating both glare at close range and insufficient light at distance while maintaining oblique imaging geometry.

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 LED light matrix provides efficient and focused illumination with reduced power consumption and heat, eliminating fire risks and enhancing imaging capabilities by optimizing light distribution and reducing glare, allowing for improved monitoring of moving webs within paper machines.

Implementation Method 1

a LED light matrix (14) comprising a numerous amount of LED components (15, 16)

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Implementation Method 2

at least two types, as for the radiation beam, of LED components with respective optics are used, i.e. separate lenses of two or more types are generally used with similar LEDs to create different beams

Methodology Applied
Scientific EffectRefraction and Focusing: Lens

Data Source

PatentEP2124041B1A unit having a camera and led light matrix equipped with impulse means
Publication Date: 2020.05.06 VALMET AUTOMATION OY
  • EP2124041B1 patent drawingFigure 1~3c
  • EP2124041B1 patent drawingFigure 4~5
  • EP2124041B1 patent drawingFigure 6~8

AI summary

The invention relates to a LED light matrix (14) equipped with impulse means for illuminating a moving object (10) in a selected area (11) from an oblique direction for video imaging, said LED light matrix (14) including a group of LEDs (15, 16) each equipped with optics for focusing the light produced by the LED, and with the group being located substantially obliquely relative to the object to be illuminated. Separate LEDs (15, 16) of the LED light matrix (14) are so oriented that the intensity distribution of illumination in the selected area (11) is weighted proportionally to the distance.