Stacked CMOS Image Sensor With Adaptive On-Sensor DNN Switching

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Solution Overview

Problem

Implementing deep neural networks (DNNs) on image sensors for advanced processing and privacy protection in devices like digital cameras is challenging due to the need for efficient integration and diversification of image processing functions.

Innovation Solution

A solid-state image capturing device with a laminated structure integrating a CMOS image sensor and a DSP, featuring a DNN processing unit, storage, evaluation, and control units, allowing dynamic DNN model changes based on environmental conditions and performance requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If deep neural network functions are integrated on the image sensor, then advanced image processing capability and privacy protection are improved, but device complexity and power consumption increase

Engineering Contradiction:
Improveadvanced image processing capabilityVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The image sensor is divided into multiple functional layers including a first substrate with pixel array and readout circuits, and a second substrate with DNN processing units. This segmentation allows advanced processing capabilities to be added without significantly complicating the overall device structure, as each layer performs specific functions independently.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from traditional planar integration to three-dimensional stacked architecture. By stacking the first substrate (pixel array) and second substrate (DNN processing) vertically, the system achieves advanced image processing capabilities while maintaining a compact form factor and managing device complexity through spatial separation of functions.

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

2Adaptability or versatility

If deep neural network functions are integrated on the image sensor, then advanced image processing capability is improved, but power consumption increases

Engineering Contradiction:
Improveadvanced image processing capabilityVSAvoidpower consumption
Core Design Contradiction:
Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The system dynamically switches between different operating modes: capturing only raw image data when advanced processing is not needed, and activating DNN processing only when required. This dynamic operation reduces overall power consumption while maintaining advanced image processing capability when needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The DNN processing units continuously receive and process image data from the pixel array without requiring data transfer to external devices. This continuous local processing eliminates transmission overhead and enables real-time advanced image processing while optimizing power usage through efficient on-sensor computation.

Inventive Principle:
Principle #20Continuity of useful action

3Adaptability or versatility

If multiple DNN models are stored for different environments, then adaptability to different conditions is improved, but storage requirements and device complexity increase

Engineering Contradiction:
Improveadaptability to different conditionsVSAvoidstorage requirements
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The DNN processing units are designed with universal architecture capable of executing multiple different DNN models. Instead of dedicating separate hardware to each model, the same processing units can load and execute different models (e.g., first DNN model for indoor environments, second DNN model for outdoor environments) as needed, reducing storage requirements while maintaining adaptability.

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

4Speed

If DNN processing is performed on the image sensor, then processing speed is improved, but device complexity increases

Engineering Contradiction:
Improveprocessing speedVSAvoiddevice complexity
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The patent merges the image capture function and DNN processing function into a single integrated device. The DNN processing units are directly coupled to the pixel array through the substrate structure, enabling immediate processing of captured images without external device communication. This merging achieves fast processing speed while managing complexity through unified design.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3846448B1Solid-state image capture device, information processing device, information processing system, information processing method, and program
Publication Date: 2026.03.18 SONY SEMICON SOLUTIONS CORP
  • EP3846448B1 patent drawingFigure 1
  • EP3846448B1 patent drawingFigure 2
  • EP3846448B1 patent drawingFigure 3

AI summary

A solid-state image capturing device (100) includes: a DNN processing unit (130) configured to execute a DNN for an input image based on a DNN model; and a DNN control unit (160) configured to receive control information generated based on evaluation information of a result of the execution of the DNN and change the DNN model based on the control information.