Photometric Apparatus Light Attenuation Linearity Correction

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Solution Overview

Problem

The existing photometric apparatuses face challenges in maintaining linear continuity of measured values when a light attenuation member is inserted or removed, due to differences in surface reflectance characteristics between objects being measured, leading to errors in luminance and chromaticity measurements.

Innovation Solution

A photometric apparatus and method that include a light receiver, a controller, a light attenuation member, and a corrector to adjust for differences in measured values based on the object's characteristics, using a reflective member with a reflectance matching the internal optical member's return rate to prevent linearity errors when the light attenuation member is inserted or removed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a light attenuation member is inserted or removed to widen the dynamic range, then the measurement capability across different luminance levels is improved, but linear continuity of measured values deteriorates due to insertion and removal errors

Engineering Contradiction:

Improvemeasurement capability across luminance levelsVSAvoidlinear continuity of measured values

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

A reflective member is introduced as an intermediary component between the light attenuation member and the object to be measured. This reflective member has a reflectance that matches the return rate of the internal optical member, serving as a mediator to maintain consistent light path characteristics whether the light attenuation member is inserted or removed, thereby preventing discontinuities in measured values

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The reflectance parameter of the reflective member is specifically designed to match the return rate parameter of the internal optical member. By adjusting and matching these optical parameters, the system maintains consistent photometric characteristics across different operational states (with or without light attenuation member inserted), resolving the linearity issue

Inventive Principle:

Principle #35Parameter changes

2Use of energy by moving object

If the reflectance of the light attenuation member surface differs from the internal reflectance, then the light attenuation function is achieved, but measurement accuracy deteriorates due to reflection differences

Engineering Contradiction:

Improvelight attenuation functionVSAvoidmeasurement accuracy

Core Design Contradiction:

Use of energy by moving objectVSMeasurement precision

Solution Approach 1:

The reflective member acts as an intermediary that compensates for the reflectance difference. By positioning the reflective member with a specific reflectance matching the internal optical member's return rate, it mediates the optical path to ensure that the measurement system experiences consistent reflection characteristics regardless of the light attenuation member's surface reflectance

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The light attenuation member's surface reflectance difference, which initially causes measurement errors, is converted into a beneficial configuration by introducing a reflective member with matched reflectance. This transforms the potential harmful effect of reflectance mismatch into a controlled optical configuration that maintains measurement accuracy while achieving light attenuation

Inventive Principle:

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

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 solution ensures consistent and accurate luminance and chromaticity measurements across varying object reflectance levels by correcting for linearity errors caused by the light attenuation member's insertion and removal, regardless of the object's surface characteristics, thereby maintaining measurement continuity and precision.

Implementation Method 1

Light received by the light receiving sensors is converted into electrical signals

Methodology Applied

Scientific EffectPhotoelectric conversion: Photoelectric Effect

Implementation Method 2

a light attenuation member that is disposed so as to be insertable in and removable from a light path of the light to be measured and attenuates the light to be incident on the light receiver

Methodology Applied

Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 3

using a reflective member with a reflectance matching the internal optical member's return rate

Methodology Applied

Scientific EffectLight reflection: Reflection

Data Source

PatentUS20250020578A1Photometric apparatus, photometric method, and calibration system

Publication Date: 2025.01.16 KONICA MINOLTA INC

AI summary

The photometric apparatus includes a light receiver having one or a plurality of light receiving sensors that receive light to be measured from an object to be measured; a controller that calculates a measured value based on an output from the one or plurality of light receiving sensors; a light attenuation member that is disposed so as to be insertable in and removable from a light path of the light to be measured and attenuates the light to be incident on the light receiver; and a corrector that corrects a difference between a measured value calculated by the controller in a state in which the light attenuation member is inserted in the light path and a measured value calculated by the controller in a state in which the light attenuation member is not inserted in the light path, the measured values varying depending on a characteristic of the object.