Quantum Dot Image Sensor Dummy Pixels Ambient Light

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Solution Overview

Problem

Conventional image sensors in digital photography are limited by their sensitivity to only the visible light range, leading to under-exposure or over-exposure and color artifacts due to variations in ambient light intensity and color temperature, as they do not accurately account for light outside this range.

Innovation Solution

Incorporating one or more quantum dot layers into the image sensor to extend its sensitivity beyond the visible range, allowing detection of infrared and ultraviolet light, which enables more accurate determination of ambient light characteristics for improved image processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional image sensors are used with sensitivity limited to visible light range, then device complexity is low, but measurement precision of ambient light characteristics deteriorates

Engineering Contradiction:
Improveaccuracy of ambient light characterizationVSAvoidsensor structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The image sensor is designed to perform multiple functions: capturing visible light for color information and detecting infrared/ultraviolet light for ambient light characterization. The quantum dot layers enable the sensor to detect multiple wavelengths simultaneously, making the device universal for both imaging and environmental sensing applications.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent incorporates quantum dot layers with specific bandgap energies into the sensor structure. These quantum dot materials have unique optoelectronic properties that enable detection of infrared and ultraviolet wavelengths, creating a composite material system that extends detection range beyond conventional silicon-based sensors.

Inventive Principle:
Principle #40Composite materials

2Measurement precision

If quantum dot layers are added to extend sensitivity range, then measurement precision of light characteristics improves, but device complexity increases

Engineering Contradiction:
Improveaccuracy of exposure and white balance calculationVSAvoidmulti-layer quantum dot structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Different quantum dot layers are positioned at specific locations within the sensor structure, with each layer having tailored bandgap energies for detecting specific wavelength ranges. This local differentiation allows precise measurement of different light characteristics while maintaining overall system integration.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent extends the sensor's detection capability from the traditional two-dimensional visible spectrum into additional wavelength dimensions (infrared and ultraviolet). This dimensional expansion allows the sensor to capture a more complete picture of ambient light characteristics across the entire electromagnetic spectrum.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Reliability

If sensitivity is limited to visible range, then manufacturing precision requirements are lower, but reliability of image exposure determination deteriorates

Engineering Contradiction:
Improveaccuracy of exposure determinationVSAvoidquantum dot layer fabrication
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent utilizes quantum dots with specifically engineered bandgap energies to detect infrared and ultraviolet light. By changing the material parameters (bandgap energy) rather than the fundamental sensor architecture, the system achieves enhanced reliability in exposure determination without requiring complete redesign of the manufacturing process.

Inventive Principle:
Principle #35Parameter changes

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 approach enables more accurate calculation of correction factors for exposure and white balance, resulting in improved image quality by considering the entire light spectrum, including visible, infrared, and ultraviolet ranges.

Implementation Method 1

one or more quantum dot layers (405) interspersed among the array of pixels (402) on the substrate. Each of the pixels (402) and the dummy pixels (405) is sensitive to light within a specified range of the electromagnetic spectrum

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentEP2498498B1Quantum dot image sensor with dummy pixels used for intensity calculations
Publication Date: 2016.07.20 BLACKBERRY LTD
  • EP2498498B1 patent drawingFigure 1
  • EP2498498B1 patent drawingFigure 2
  • EP2498498B1 patent drawingFigure 3

AI summary

An image sensor of a camera unit comprises raw image pixels for generating raw image color representing the exposed scene image. The sensor also comprises dummy pixels for supplemental data pertaining to characteristics of light exposing the scene image. A image sensor processor generates a processed digital image by adjusting component color values, obtained from raw image color data, by one or more adjustment factors calculated from supplemental image data. The adjustment factors are calculated according a selected mode of operation.