Pixel Readout Circuit for Multi-Mode Infrared Detection

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Solution Overview

Problem

Existing multi-mode imaging devices, such as missile seekers, are costly and complex due to the need for disparate sensor systems for infra-red and semi-active laser detection, limiting their use in compact, low-power applications.

Innovation Solution

A pixel readout integrated circuit (ROIC) with advanced on-chip processing that integrates multiple detection modes, including thermal imaging, laser pulse detection, and range finding, allowing simultaneous operation in various imaging and detection modes within a single pixel array.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple disparate sensor systems are used for infra-red and semi-active laser detection, then detection capability is improved, but device complexity and cost increase

Engineering Contradiction:
Improvedetection capabilityVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines infra-red detection and semi-active laser detection into a single integrated detector device. The detector uses a single photodiode that can operate in multiple modes: thermal imaging mode for general IR detection and pulsed mode for laser detection. This merging eliminates the need for separate sensor systems while maintaining both detection capabilities, thereby reducing device complexity and cost.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The detector is designed with universal functionality to perform both thermal imaging and laser detection using the same photodiode element. The readout circuit can selectively operate in different modes (thermal imaging mode or pulsed laser detection mode) based on the detection requirements, making the device multi-functional without requiring separate specialized sensors for each function.

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

2Adaptability or versatility

If multiple disparate sensor systems are used for infra-red and semi-active laser detection, then detection capability is improved, but cost increases

Engineering Contradiction:
Improvedetection capabilityVSAvoidcost
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent merges multiple detection functions into a single detector device with one photodiode, eliminating the need to manufacture and assemble multiple separate sensor systems. This integration reduces manufacturing complexity, assembly requirements, and overall cost while maintaining both thermal imaging and laser detection capabilities.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The universal detector design allows a single device to perform both thermal imaging and semi-active laser detection, reducing the total number of components that need to be manufactured and integrated. This multi-functionality approach lowers material costs, manufacturing overhead, and system integration expenses compared to using separate specialized sensors.

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

3Productivity

If image frame rate is increased, then imaging speed is improved, but image resolution or image size decreases

Engineering Contradiction:
Improveimage frame rateVSAvoidimage resolution
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The readout circuit is designed with dynamic switching capability that allows it to adapt between different operating modes. The circuit can selectively switch between thermal imaging mode (for higher resolution) and pulsed laser detection mode (for faster frame rates), enabling the system to optimize performance based on detection requirements without being constrained by a fixed trade-off.

Inventive Principle:
Principle #15Dynamics

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 compact, low-power, and cost-effective multi-function infrared detectors with enhanced detection capabilities, including precise range finding and laser spot detection, improving target acquisition and tracking accuracy.

Implementation Method 1

Photonic detector devices respond to received photons by creating an electric effect which can be quantified and hence provide information as regards the flux of the received photons

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Implementation Method 2

a time of flight pixel which is also able to provide time integrated signal

Methodology Applied
Scientific EffectTime of flight: Time of Flight

Data Source

PatentEP2512125B1A detector pixel signal readout circuit and an imaging method thereof
Publication Date: 2018.07.04 SEMICON DEVICES AN ELBIT SYSTEMSRAFAEL PARTNERSHIP IL
  • EP2512125B1 patent drawingFigure 1A~1B
  • EP2512125B1 patent drawingFigure 2
  • EP2512125B1 patent drawingFigure 3

AI summary

A pixel readout circuit for use with an imaging pixel array, said pixel readout circuit comprising: an input channel for receiving an image signal corresponding to electrical output of a photosensitive element of the pixel; and an electronic circuit interconnected between said input channel and an output readout utility. The electronic circuit comprises a capacitive unit, and a single analyzer. The capacitive unit is controllably linked to said input channel for accumulating a charge corresponding to received intensity generated by said pixel during a single frame period, and is connected to said output readout utility for transmitting image data thereto. The signal analyzer unit is controllably linked to said input channel for receiving and analyzing at least a part of said image signal, and is connected to said output readout utility, and is configured and operable for analyzing said at least a part of said image signal by determining an amount of accumulated charge corresponding to said received intensity, and upon detecting that said amount of the accumulated charge satisfies a predetermined condition generating data indicative of a detected event and transmitting said data to said output readout utility.