Dual Green Filter Imaging Element for Brightness Adaptation

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Solution Overview

Problem

Existing imaging apparatuses, such as those disclosed in JP2000-196952A, are unable to sufficiently control the green component of an image based on brightness levels, unlike their control over blue and red components.

Innovation Solution

An imaging element comprising two types of green color filters with different spectral sensitivity peaks, along with a controller that adjusts image signals based on illumination levels, is used to generate image signals that effectively control the green component in accordance with brightness levels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a single green color filter is used, then the device complexity is reduced, but the ability to control green component according to brightness level is insufficient

Engineering Contradiction:

Improvebrightness level adaptationVSAvoidcolor filter configuration

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The green color filter layer is segmented into two distinct types: a first green color filter with higher spectral sensitivity peak and a second green color filter with lower spectral sensitivity peak. This segmentation enables different green-sensitive pixels to respond differently to various brightness levels, allowing the imaging apparatus to capture green component information across a wider brightness range while maintaining adaptability to luminosity conditions.

Inventive Principle:

Principle #1Segmentation

2Adaptability or versatility

If multiple green color filters with different spectral sensitivities are used, then the green component control according to brightness level is improved, but the manufacturing precision requirements increase

Engineering Contradiction:

Improvegreen component controlVSAvoidspectral sensitivity differentiation

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

Different regions of the imaging element are assigned different types of green color filters based on their spectral sensitivity characteristics. The first green color filters with higher spectral sensitivity peaks are positioned in regions optimized for brighter conditions, while second green color filters with lower spectral sensitivity peaks are positioned in regions optimized for darker conditions. This local quality differentiation enables precise control of green component according to brightness level while maintaining feasible manufacturing tolerances.

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

This configuration allows for precise control of the green component in captured images, ensuring that the image reflects the characteristics of human visual sensitivity in varying light conditions, preventing reduction in brightness signal resolution and avoiding moire patterns.

Implementation Method 1

The first green color filter has a spectral sensitivity peak in a wavelength region higher than the wavelength of a spectral sensitivity peak of the second green color filter

Methodology Applied

Scientific EffectSpectral sensitivity: Absorption (EM radiation)

Data Source

PatentUS8842194B2Imaging element and imaging apparatus

Publication Date: 2014.09.23 PANASONIC HOLDINGS CORP

AI summary

An imaging element includes a red color filter, a blue color filter, and two kinds of first and second green color filters. The first green color filter has a peak spectral sensitivity in a longer wavelength region than a wavelength of a peak spectral sensitivity of the second green color filter.