Image Sensor ACiM Architecture for In-Sensor Convolution

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Solution Overview

Problem

Current electronic devices face increased power and delay overhead in processing large-capacity data due to memory data access and transfer, particularly in AI applications like deep learning, where existing solutions do not effectively integrate analog computing-in-memory (ACiM) technology with image sensors.

Innovation Solution

An image sensor design incorporating analog computing-in-memory (ACiM) technology, featuring a pixel array and memory cell array on separate dies, with control signals generated to process pixel and convolution signals, allowing for efficient data processing by converting analog signals to digital and vice versa using analog-to-digital converters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If traditional digital signal processing is used in image sensors, then processing accuracy is maintained, but power consumption and delay increase significantly due to memory data access and transfer overhead

Engineering Contradiction:
Improvepower consumptionVSAvoiddata processing efficiency
Core Design Contradiction:
Use of energy by moving objectVSProductivity

Solution Approach 1:

The patent merges the pixel array and memory cell array into a single integrated circuit structure where pixels and memory cells share common readout circuits and column lines. This integration enables analog computing-in-memory operations directly within the sensor array, eliminating the need for separate memory access and transfer operations, thereby reducing power consumption and processing delay while maintaining computational accuracy.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent replaces traditional digital signal processing mechanisms with analog computing operations performed directly in the memory array. Instead of transferring data to external processors for digital computation, the system performs matrix multiplication and convolution operations analogously within the memory cells themselves, substituting the mechanical data transfer and digital processing sequence with a unified analog computation process that reduces overhead.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If separate pixel array and memory array are used, then data processing capability is improved, but occupied area and device complexity increase

Engineering Contradiction:
Improvedata processing capabilityVSAvoidoccupied area
Core Design Contradiction:
ProductivityVSArea of stationary object

Solution Approach 1:

The patent combines the pixel array and memory cell array into a single integrated structure where both functional elements coexist on the same substrate and share common readout circuits and column lines. This merging approach enables the system to maintain enhanced data processing capability through analog computing operations while significantly reducing the total occupied area compared to having separate arrays requiring independent readout paths and processing circuits.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent designs the integrated array where each element serves multiple functions: pixels perform both light detection and participate in analog computing operations, while memory cells store data and perform convolution operations. The shared readout circuits and column lines serve both pixel readout and memory cell access functions, enabling multi-functionality that reduces overall device complexity and occupied area while maintaining high data processing capability.

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

3Use of energy by moving object

If analog computing-in-memory is implemented, then power consumption is reduced, but manufacturing precision requirements increase

Engineering Contradiction:
Improvepower consumptionVSAvoidanalog signal precision
Core Design Contradiction:
Use of energy by moving objectVSManufacturing precision

Solution Approach 1:

The patent implements self-service mechanisms where the analog computing operations are performed automatically within the memory array without requiring external precision control systems. The shared readout circuits and column lines inherently provide the necessary signal conditioning and timing synchronization, allowing the system to maintain analog signal precision through its own internal mechanisms rather than requiring external precision manufacturing and control infrastructure.

Inventive Principle:
Principle #25Self-service

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 design improves the performance-to-power ratio for data processing in image sensors by enabling analog matrix multiplication, reducing occupied area and enhancing efficiency in deep learning operations.

Implementation Method 1

Image sensors are devices for capturing images using the property of a semiconductor which reacts to light

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentUS20240323567A1Image sensor and operating method thereof
Publication Date: 2024.09.26 SK HYNIX INC
  • US20240323567A1 patent drawing
  • US20240323567A1 patent drawing
  • US20240323567A1 patent drawing

AI summary

Disclosed is an image sensor including a plurality of column lines, a plurality of pixels coupled to the plurality of column lines, and configured to output a plurality of pixel signals to the plurality of column lines in response to first control signals, and a plurality of memory cells coupled to the plurality of column lines, and configured to output a plurality of convolution signals, in which a plurality of data signals are reflected in the plurality of pixel signals, to the plurality of column lines in response to second control signals.