Solid State Imaging Device Analog-to-Digital Conversion Circuit

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Solution Overview

Problem

Existing solid state imaging devices require large circuit sizes and are not optimized for high-speed operation and low power consumption due to the need for time division and multiple line memories in analog-to-digital conversion techniques.

Innovation Solution

A solid state imaging device with two analog-to-digital converting units that compare analog pixel signals with reference signals of different inclinations, allowing simultaneous conversion and composition of digital pixel signals without the need for line memories, reducing circuit size and enabling high-speed operation and low power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If time division is employed to generate multiple analog reference signals, then dynamic range can be enlarged, but circuit size increases and operation speed decreases

Engineering Contradiction:

Improvedynamic rangeVSAvoidcircuit size

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the dynamic range into multiple regions by using multiple analog reference signals with different inclinations. Each reference signal covers a specific dynamic range region, allowing the system to handle both dark and bright portions effectively without requiring large circuit size or time division.

Inventive Principle:

Principle #1Segmentation

2Adaptability or versatility

If time division is employed for analog-to-digital conversion, then dynamic range can be enlarged, but operation speed decreases and power consumption increases

Engineering Contradiction:

Improvedynamic rangeVSAvoidoperation speed

Core Design Contradiction:

Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent generates multiple analog reference signals with different inclinations in advance, before the actual analog-to-digital conversion. This preliminary preparation allows the conversion to proceed in parallel without time division, significantly improving operation speed and reducing power consumption while maintaining enlarged dynamic range.

Inventive Principle:

Principle #10Preliminary action

3Adaptability or versatility

If multiple line memories are used to store digital pixel signals, then dynamic range can be enlarged, but circuit size increases

Engineering Contradiction:

Improvedynamic rangeVSAvoidcircuit size

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges the functionality of multiple line memories into a single memory structure by using multiple analog reference signals with different inclinations simultaneously. This allows the system to store and process digital pixel signals for different dynamic range regions without requiring separate line memories, thereby reducing circuit size.

Inventive Principle:

Principle #5Merging (Combining)

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

The solution reduces circuit size, enhances operational speed, and decreases power consumption by eliminating the need for time division and line memories, while maintaining a large dynamic range and low noise in digital pixel signals.

Implementation Method 1

a first analog-to-digital converting unit that compares a level of an analog reference signal with a first inclination with a level of an analog pixel signal output from a pixel array unit, and converts the analog pixel signal into a first digital pixel signal

Methodology Applied

Scientific EffectAnalog-to-digital conversion:

Implementation Method 2

a second analog-to-digital converting unit that compares a level of an analog reference signal with a second inclination that is different in inclination from the analog reference signal with the first inclination with a level of the analog pixel signal, and converts the analog pixel signal into a second digital pixel signal

Methodology Applied

Scientific EffectAnalog-to-digital conversion:

Implementation Method 3

a digital compositing unit that composites the first digital pixel signal with the second digital pixel signal, and outputs a composite result

Methodology Applied

Scientific EffectSignal compositing:

Data Source

PatentUS9973720B2Solid state imaging device, method of outputting imaging signal and electronic device

Publication Date: 2018.05.15 SONY GROUP CORP

AI summary

There is provided a solid state imaging device including a first analog-to-digital converting unit that compares a level of an analog reference signal with a first inclination with a level of an analog pixel signal output from a pixel array unit, and converts the analog pixel signal into a first digital pixel signal, a second analog-to-digital converting unit that compares a level of an analog reference signal with a second inclination that is different in inclination from the analog reference signal with the first inclination with a level of the analog pixel signal, and converts the analog pixel signal into a second digital pixel signal, and a digital compositing unit that composites the first digital pixel signal with the second digital pixel signal, and outputs a composite result.