Charge Multiplying Solid-State Imaging Device Feed-Forward Control

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Solution Overview

Problem

Solid-state imaging devices, such as EM-CCDs, face challenges in accurately controlling the multiplication factor of their multiplication register units to match the dynamic range with the intensity distribution of incident light, particularly in applications like spectrometers, due to reliance on feedback control based on previous read-out positions.

Innovation Solution

Implementing feed-forward control of the multiplication factor in real-time using a detection unit and control unit to adjust the charge transfer, allowing for appropriate control of the multiplication factor at the present read-out position, potentially with the aid of a delay register unit to manage charge transfer timing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If feedback control is used to control the multiplication factor based on previous read-out position output, then the device can operate with existing control mechanisms, but the multiplication factor cannot be appropriately controlled for present read-out position light intensity

Engineering Contradiction:
Improvecontrol accuracyVSAvoidcontrol timing delay
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by detecting the charge amount at the present read-out position in advance (before multiplication) and using this information to control the multiplication factor. The detection unit measures the incident light intensity currently, and this detection result is fed forward to control the multiplication register unit, ensuring the multiplication factor is set appropriately before the actual multiplication occurs, thus eliminating the timing delay inherent in feedback control.

Inventive Principle:
Principle #10Preliminary action

2Device complexity

If feedback control is implemented, then the system can maintain operational simplicity, but the dynamic range cannot be appropriately matched to the intensity distribution of incident light

Engineering Contradiction:
Improvecontrol system complexityVSAvoiddynamic range matching
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent implements preliminary action by detecting the charge amount at the present read-out position before multiplication and using this advance information to control the multiplication factor. This feed-forward approach allows the system to adapt the multiplication factor to the actual incident light intensity distribution, properly matching the dynamic range without requiring complex feedback control mechanisms.

Inventive Principle:
Principle #10Preliminary action

3Stability of the object's composition

If the multiplication factor is controlled based on previous timing output, then the existing feedback control structure can be maintained, but appropriate control for present timing light intensity cannot be achieved

Engineering Contradiction:
Improvecontrol structure stabilityVSAvoidlight intensity measurement accuracy
Core Design Contradiction:
Stability of the object's compositionVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by detecting the charge amount at the present read-out position in advance and using this detection result to control the multiplication factor before multiplication occurs. This eliminates the timing mismatch between light intensity measurement and multiplication factor application, achieving precise control without destabilizing the overall control structure.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feed-forward control by detecting the charge amount at the present read-out position and using this information to control the multiplication factor in advance. This approach provides accurate real-time control of the multiplication factor based on actual incident light intensity, improving measurement precision while maintaining control structure stability through a deterministic control flow.

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

This approach enables precise matching of the dynamic range of the solid-state imaging device to the intensity distribution of incident light, improving the device's ability to handle varying light intensities effectively.

Implementation Method 1

an imaging area that includes a plurality of photodiodes or the like and generates charges according to the amount of incident light

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Implementation Method 2

a multiplication register unit that multiplies the read-out charges, and enables taking an image of weak light by using a charge multiplication effect of the multiplication register unit

Methodology Applied
Scientific EffectImpact ionization: Avalanche Breakdown

Data Source

PatentEP2385696B1Solid-state imaging device
Publication Date: 2018.11.28 HAMAMATSU PHOTONICS KK
  • EP2385696B1 patent drawingFigure 1
  • EP2385696B1 patent drawingFigure 2(a)~2(b)
  • EP2385696B1 patent drawingFigure 3

AI summary

A solid-state imaging device 1 according to one embodiment of the present invention is a charge multiplying solid-state imaging device, and includes an imaging area 10 that generates a charge according to the amount of incident light, an output register unit 20 that receives the charge from the imaging area 10, and a multiplication register unit 28 that multiplies the charge from the output register 20, and performs feed-forward control of the multiplication factor of the multiplication register unit 28 according to the charge amount from the imaging area 10.