Solid-State Imaging Pixel Floating Diffusion Switching for Power Reduction

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Solution Overview

Problem

Existing techniques for reducing power consumption in solid-state imaging devices often require higher resolution readouts followed by digital signal processing, limiting the ability to achieve low power consumption without deteriorating imaging characteristics.

Innovation Solution

A solid-state imaging device with a floating diffusion (FD) set in units of shared pixels, connected by a floating interconnection line, where switches control the connection and disconnection of these lines to optimize power usage based on demanded resolution, allowing for efficient pixel signal summation and reduced readouts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If higher resolution readout is performed followed by digital signal processing to reduce resolution, then imaging characteristics of all pixels are maintained, but power consumption cannot be sufficiently reduced

Engineering Contradiction:
Improveimaging characteristicsVSAvoidpower consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The pixel array is divided into multiple regions with different resolution settings. Each region can be independently configured to output at full resolution or reduced resolution, allowing selective application of resolution reduction where appropriate while maintaining high resolution where needed, thus balancing power consumption with imaging quality requirements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The resolution setting is made dynamic and adjustable rather than fixed. The system can switch between full resolution and reduced resolution modes based on actual imaging requirements, enabling power consumption optimization without permanently sacrificing imaging characteristics when high resolution is needed.

Inventive Principle:
Principle #15Dynamics

2Use of energy by moving object

If resolution is reduced by sharing pixels or adjacent pixels, then power consumption is reduced, but imaging characteristics of all pixels deteriorate

Engineering Contradiction:
Improvepower consumptionVSAvoidimaging characteristics
Core Design Contradiction:
Use of energy by moving objectVSMeasurement precision

Solution Approach 1:

Different regions of the pixel array are assigned different quality levels. Some regions maintain full pixel functionality and high resolution for critical imaging areas, while other regions use pixel sharing or skipping techniques for reduced resolution in less critical areas, allowing power reduction without uniform degradation of all pixel imaging characteristics.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

Resolution reduction is applied partially rather than universally. The system selectively reduces resolution in specific regions or under specific conditions rather than applying it to all pixels, thus achieving power savings while maintaining sufficient imaging quality where it matters most.

Inventive Principle:
Principle #16Partial or excessive action

3Use of energy by moving object

If pixel skipping or binning is used to reduce readout amount, then power consumption decreases, but signal-to-noise ratio and imaging quality are compromised

Engineering Contradiction:
Improvepower consumptionVSAvoidsignal-to-noise ratio
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The system dynamically adjusts between pixel skipping/binning modes and full readout modes based on lighting conditions, scene requirements, and power availability. This dynamic switching allows the system to use pixel combination techniques only when appropriate, maintaining signal-to-noise ratio when full resolution is needed while saving power when reduction is acceptable.

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 image capture at low resolution with low power consumption without compromising imaging characteristics, by minimizing parasitic capacity and optimizing power reduction through staggered switch timing and FD summation.

Implementation Method 1

a photodiode, and a pixel circuit, wherein the photodiode includes a first region in which a plurality of photosensitive pixels are arranged in a matrix format

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Implementation Method 2

A solid-state imaging device according to one aspect of the present disclosure is a solid-state imaging device including an FD (floating diffusion) set in a unit of shared pixels

Methodology Applied
Scientific EffectCharge accumulation: Capacitance

Data Source

PatentEP3487166B1Solid-state imaging element, method for operating solid-state imaging element, imaging device, and electronic device
Publication Date: 2022.01.05 SONY SEMICON SOLUTIONS CORP
  • EP3487166B1 patent drawingFigure 1
  • EP3487166B1 patent drawingFigure 2~3
  • EP3487166B1 patent drawingFigure 4

AI summary

The present disclosure relates to a solid-state imaging device, a solid-state imaging device operating method, an imaging apparatus, and an electronic apparatus that can realize an image at a low resolution with low power consumption without deteriorating imaging characteristics of all pixels. A floating interconnection line connecting FDs (floating diffusions) each set in a unit of shared pixels including at least one or more pixels, the FDs being provided in each column having a predetermined column number, and a switch changing over between connection and disconnection of the floating interconnection line to and from the FDs are provided. In addition, the switch changes over between the connection and the disconnection between the FDs and the floating interconnection line in response to a resolution that is a low resolution. The present disclosure can be applied to a solid-state imaging device.