Color Sensor Saturation Detection Using Reference Pixels

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Solution Overview

Problem

Conventional solid-state imaging devices and color sensors face challenges in accurately acquiring spectrum information due to saturation issues when a fixed quantity or more of light is irradiated, leading to false spectrum data and inability to distinguish between reference voltage output and zero changes caused by insufficient light or saturation.

Innovation Solution

A method and device that include a reference pixel and measurement pixels, where charges are accumulated for a prescribed measurement time, with a saturation determination unit to identify and manage saturated outputs, adjusting sensitivity as needed to prevent false readings and ensure accurate spectrum information acquisition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a fixed quantity or more of light is irradiated onto the color sensor, then the measurement pixels accumulate sufficient charges for detection, but saturation occurs leading to false spectrum data

Engineering Contradiction:

Improvespectrum information accuracyVSAvoidmeasurement reliability under high light exposure

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The pixel array is divided into reference pixels (without color filters) and measurement pixels (with color filters). The reference pixels accumulate total light charges while measurement pixels accumulate wavelength-specific charges. By comparing reference signal with measurement signals, the system can identify saturation conditions and correct measurement data, preventing false spectrum information.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system uses feedback by comparing measurement signals with reference signals to detect saturation conditions. When saturation is detected, the system adjusts sensitivity or discards affected measurements, ensuring reliable spectrum information acquisition under varying light conditions.

Inventive Principle:

Principle #23Feedback

2Measurement precision

If the integration time is extended to improve sensitivity, then more charges are accumulated for better detection, but saturation occurs more easily under high light exposure

Engineering Contradiction:

Improvedetection sensitivityVSAvoidsaturation effect under high light exposure

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary saturation detection by comparing reference pixel outputs with measurement pixel outputs before final spectrum analysis. This preliminary action identifies saturation conditions early, allowing the system to adjust sensitivity or discard affected measurements before they corrupt the spectrum data.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts sensitivity parameters based on detected saturation conditions. When saturation is detected, the system changes sensitivity settings or integration time for subsequent measurements, optimizing detection capability while avoiding saturation under high light exposure.

Inventive Principle:

Principle #35Parameter changes

3Measurement precision

If the sensitivity is increased to detect weaker light signals, then detection capability improves, but false saturation readings may occur

Engineering Contradiction:

Improveweak light signal detection capabilityVSAvoidfalse saturation data

Core Design Contradiction:

Measurement precisionVSLoss of information

Solution Approach 1:

The system uses feedback comparison between reference and measurement signals to verify detection validity. When high sensitivity detection is performed, the reference signal provides a feedback mechanism to identify false saturation readings, allowing the system to distinguish between genuine saturation and detection artifacts.

Inventive Principle:

Principle #23Feedback

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

Enables accurate acquisition of spectrum information by differentiating between saturated and valid outputs, preventing false data and ensuring reliable measurements even under conditions of high light exposure.

Implementation Method 1

an anode of a photodiode 10 that is used to receive light and generate photoelectric current

Methodology Applied

Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentUS8884210B2Spectrum information measurement method, color sensor and virtual slide device

Publication Date: 2014.11.11 OLYMPUS CORPORATION(JP)

AI summary

A spectrum information measurement method may include steps of; controlling a reference pixel accumulating charges based on an amount of light irradiated from a test specimen; controlling a plurality of measurement pixels accumulating the charge based on an amount of light that is irradiated from the test specimen and has a prescribed wavelength; generating and outputting a reference signal based on an amount of change in the charge that is accumulated in the reference pixel over the prescribed measurement time; generating and outputting a plurality of measurement signals based on an amount of change in the charge that is accumulated in each of the plurality of measurement pixels over the prescribed measurement time; determining whether or not any one or more of the plurality of measurement signals is greater than the reference signal, and determining that the measurement signal that is greater than the reference signal includes saturated output.