Image Sensor Pixel Array Segmentation for Light Sensitivity

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Solution Overview

Problem

Existing electronic image sensors face challenges in achieving high light sensitivity and image quality, particularly when capturing color images, due to the use of color filters which reduce light sensitivity and require complex systems with multiple sensors and beam splitters, limiting their application in handheld devices and dynamic scenes.

Innovation Solution

A digital camera system employing a two-dimensional array of both color and panchromatic pixels, with specific filter patterns and image processing techniques that combine signals from these pixels to enhance sensitivity and image quality, allowing for improved light sensitivity and reduced noise across a wide range of lighting conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If color filters are applied to pixels to capture color images, then color information is obtained, but light sensitivity is reduced

Engineering Contradiction:
Improvecolor information accuracyVSAvoidlight sensitivity
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The image sensor array is segmented into multiple types of pixels including color-filtered pixels (for color information) and panchromatic pixels (for high-sensitivity luminance information). This segmentation allows each pixel type to specialize in capturing specific image data, resolving the contradiction between color accuracy and light sensitivity by distributing different functions across different pixel segments.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent merges the advantages of both color-filtered pixels and panchromatic pixels by combining their output signals through image processing. The color pixels provide accurate color information while the panchromatic pixels provide high-sensitivity luminance data, and merging these complementary data sources produces an image that achieves both color accuracy and high light sensitivity.

Inventive Principle:
Principle #5Merging (Combining)

2Productivity

If multiple sensors with beam splitters are used to improve light sensitivity, then photographic speed improves, but device complexity increases

Engineering Contradiction:
Improvephotographic speedVSAvoidsystem complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

Instead of using multiple separate sensors with beam splitters, the patent merges multiple pixel types (color-filtered and panchromatic) into a single two-dimensional sensor array. This integration achieves the light sensitivity benefits of multiple sensors while eliminating the mechanical complexity of beam splitters and multiple sensor assemblies, making the system suitable for handheld devices.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent replaces the mechanical beam splitter system with an electronic/image processing solution. Rather than physically splitting light paths with mechanical components, the system uses a single sensor array with different pixel types and processes the signals electronically, eliminating moving parts and mechanical complexity while maintaining improved photographic speed.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Use of energy by moving object

If unfiltered pixels are used to increase sensitivity, then light sensitivity improves, but color information is lost

Engineering Contradiction:
Improvelight sensitivityVSAvoidcolor information
Core Design Contradiction:
Use of energy by moving objectVSLoss of information

Solution Approach 1:

The sensor array is segmented into specialized pixel regions: color-filtered pixels that capture color information and unfiltered panchromatic pixels that capture high-sensitivity luminance information. This spatial segmentation allows color information to be preserved where needed while maximizing light sensitivity in other regions, resolving the contradiction between sensitivity and color information retention.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The panchromatic pixels act as intermediaries that capture high-sensitivity luminance data without color filtering. Their output is then integrated with the color information from filtered pixels through image processing, serving as a mediator that preserves color information while enhancing overall light sensitivity of the system.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 system achieves improved image quality and light sensitivity by effectively combining color and panchromatic pixel signals, enabling the capture of high-resolution images with reduced noise and increased sensitivity, suitable for various lighting conditions and applications.

Implementation Method 1

An electronic imaging system depends on an electronic image sensor to create an electronic representation of a visual image

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentEP2092757B1Processing images having color and panchromatic pixels
Publication Date: 2018.07.18 OMNIVISION TECHNOLOGIES INC
  • EP2092757B1 patent drawingFigure 1
  • EP2092757B1 patent drawingFigure 2~3
  • EP2092757B1 patent drawingFigure 4A~5

AI summary

A method of processing an array of pixels captured by an image capture device, having a first two-dimensional array of pixels from the image capture device, some of which are color pixels, and some of which are panchromatic pixels; determining in response to ambient lighting conditions, whether panchromatic pixels are to be combined with color pixels; combining pixels to produce a second two-dimensional array of pixels which has fewer pixels than the first two-dimensional array of pixels; and correcting the color pixels.