Illuminance Acquiring Device Noise Modeling

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing methods for acquiring illuminance, such as those using CCD sensors, face challenges in precision due to noise influence and require recalculating conversion equations for high dynamic range images, leading to inaccuracies in brightness and color tone evaluation of display screens.

Innovation Solution

An illuminance acquiring device and method that calculates noise-model data to account for noise in CCD sensors, allowing for precise conversion of light energy into radiant illuminance by considering noise influence through a correspondence relation and exposure time, thereby improving the accuracy of image evaluation processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the intensity of light is acquired by using the output value of the CCD sensor without considering noise influence, then the calculation process is simple, but the calculated radiant illuminance is changed by the method of setting the exposure time and lacks precision

Engineering Contradiction:

Improveprecision of radiant illuminance calculationVSAvoidcomplexity of noise modeling process

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-calculating noise-model data for multiple exposure times before the actual measurement. The noise-model data calculating section computes the noise characteristics in advance, storing them for later use. This allows the illuminance calculating section to simply subtract the pre-computed noise from the actual sensor output, avoiding complex real-time noise analysis while maintaining high precision.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces noise-model data as an intermediary element between the raw sensor output and the final illuminance calculation. This intermediary data represents the expected noise characteristics for different exposure times and allows the system to compensate for noise influence without directly analyzing the complex noise sources. The noise-model data acts as a mediator that simplifies the relationship between exposure time, sensor output, and true illuminance.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If multiple image data with different exposure conditions are synthesized to generate high dynamic range image data, then the dynamic range is expanded, but the conversion equation must be recalculated whenever synthesizing image data, leading to considerable changes in image data values due to noise

Engineering Contradiction:

Improvedynamic range of image dataVSAvoidstability of image data values

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies parameter changes by systematically varying the exposure time parameter and pre-calculating the corresponding noise-model data for each exposure time. By establishing the relationship between exposure time and noise characteristics in advance, the system can reliably synthesize high dynamic range images by simply selecting and combining data from different exposure times using the pre-computed noise models, without needing to recalculate conversion equations.

Inventive Principle:

Principle #35Parameter changes

3Manufacturing precision

If the conversion equation is recalculated whenever synthesizing image data, then the image data with high dynamic range can be generated without exposure-excess or exposure-shortage areas, but the noise influence causes considerable changes in the value of image data

Engineering Contradiction:

Improveprecision of image data synthesisVSAvoidcomplexity of recalculation process

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent eliminates the need for recalculation by performing the noise-model data calculation in advance for all required exposure times. This preliminary computation stores the noise characteristics that would otherwise need to be calculated repeatedly during image synthesis. The result is a stable, reliable process that maintains high precision without the complexity of real-time equation recalculation.

Inventive Principle:

Principle #10Preliminary action

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 enables high-precision acquisition of light intensity, reducing noise-related errors and enhancing the reliability of image evaluation processes by accurately modeling and accounting for noise in the image pickup device's output values.

Implementation Method 1

an image pickup device for converting the intensity of light into electric energy

Methodology Applied

Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentUS8013891B2Illuminance acquiring device, illuminance acquiring method, and illuminance acquiring program

Publication Date: 2011.09.06 SEIKO EPSON CORP

AI summary

An illuminance acquiring device calculates the intensity of light sensed by the image pickup device acquired every different exposure time, and acquires the calculated intensity of light. The illuminance acquiring device including a noise-model data calculating section calculating noise-model data for modeling an influence of a noise generated in the image pickup device by using image pickup data obtained by means of the image pickup at different exposure time; and an illuminance calculating section calculating the output value of the image pickup device in consideration of the influence of the noise from the noise-model data and the output value of the image pickup device, acquiring the light energy by using the calculated output value, and calculating the intensity of the sensed light.