Angled Reflective Surfaces in Rotatable Disc Photometric Detection

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Solution Overview

Problem

Existing analytical devices face challenges in optimizing the production process for photometric detection, including light beam deflection issues due to polymer melt flow around inserts and gas bubble interference during liquid analysis, which affects the accuracy of optical measurements.

Innovation Solution

The device features a rotatable disc with cuvettes and optical means arranged such that the light beam is deflected at an angle different from 90° to the radial direction, using separate micro channels for liquid inlet and gas removal to minimize mixing and polarisation, and the reflective surfaces are angled to prevent polymer melt irregularities during injection moulding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the light beam is deflected at 90° to the radial direction using inserts in the mould, then the reflective surface can be produced, but the polymer melt flows around the insert causing partial polarisation and mixing zones that affect optical accuracy

Engineering Contradiction:
Improvereflective surface qualityVSAvoidoptical measurement accuracy
Core Design Contradiction:
Manufacturing precisionVSMeasurement precision

Solution Approach 1:

The patent applies asymmetry by positioning the reflective surface at an angle different from 90° relative to the radial direction. This asymmetric arrangement prevents the polymer melt from flowing symmetrically around the insert, thereby eliminating the mixing zone and partial polarisation effects that would otherwise occur at the backside of the insert, while still achieving the required light deflection function.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent applies local quality by creating a specific angular arrangement of the reflective surface relative to the radial direction. This local geometric configuration is designed to specifically address the polymer melt flow issue at the critical location where the light beam interacts with the surface, while maintaining the overall structural integrity of the device.

Inventive Principle:
Principle #3Local quality

2Measurement precision

If separate micro channels are used for liquid inlet and gas removal, then gas bubble interference is minimized, but the device complexity increases

Engineering Contradiction:
Improveoptical analysis accuracyVSAvoidchannel arrangement complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the fluid transport function into separate micro channels: one dedicated to liquid inlet and another to gas removal. This segmentation prevents mixing between liquid and gas flows, ensuring that gas bubbles are removed without interfering with the liquid sample being analyzed, thereby maintaining optical measurement accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses the separate micro channels as intermediary pathways that facilitate the independent transport of liquid and gas. These channels act as mediators between the sample introduction and gas removal functions, preventing direct interaction between the liquid sample and gas bubbles while still achieving the dual function of sample loading and degassing.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If the reflective surface is arranged at an angle different from 90° to the radial direction, then polymer melt flow issues are avoided, but the optical path length through the cuvette changes

Engineering Contradiction:
Improvesurface production qualityVSAvoidoptical path length
Core Design Contradiction:
Manufacturing precisionVSLength of moving object

Solution Approach 1:

The patent applies parameter changes by adjusting the angular parameter of the reflective surface relative to the radial direction. This parameter modification optimizes the manufacturing process by avoiding polymer melt flow problems, while the resulting change in optical path length is compensated for during the calibration and analysis phases, maintaining measurement accuracy.

Inventive Principle:
Principle #35Parameter changes

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 arrangement enhances the reflective properties of the surfaces, reduces the influence of gas bubbles, and simplifies the production process, ensuring accurate and reliable optical analysis by preventing light beam interference from gas bubbles and polymer melt irregularities.

Implementation Method 1

reflection means are arranged within the disc like device to direct a light beam through the cuvettes, the reflective means being arranged such, that at least part of the light beam is first deflected or guided through the respective cuvette in a direction in an angle to the respective radially outward direction on the disc

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 2

The liquid polymer-melt is introduced into the mould at the centre of the disc, which means at the rotation axis of the disc like device, the flow of the liquid polymer is directed radially outward

Methodology Applied
Scientific EffectFluid flow:

Implementation Method 3

the respective light beam being absorbed partially for the analysis of the sample or its chemistry respectively photometric determination of fluid chemistry

Methodology Applied
Scientific EffectLight absorption: Absorption (EM radiation)

Data Source

PatentEP1752759B1Photometric in plane detection using a rotatable disc
Publication Date: 2012.05.02 F HOFFMANN LA ROCHE & CO AG
  • EP1752759B1 patent drawingFigure 1~3
  • EP1752759B1 patent drawingFigure 4~5
  • EP1752759B1 patent drawingFigure 6a~6b

AI summary

On an analytical device for photometric detection of chemistry and/or fluid samples comprising a rotatable disc like body (1) a plurality of receptables (7) for fluid samples and optical means (9) for guiding light beams through the receptables are arranged. At least part of the optical means (9) are designed and/or arranged such, that at least part of the light beams is deflected and guided through the receptables in an angle to the radially outward direction on the disc like body (1) which means in an angle to the radius, connecting the respective optical means with the rotation axis (9) of the disc like body (1).