Image Sensor Temperature Detection via Pixel Array Dark Images

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Solution Overview

Problem

Conventional image sensors are not suitable for a wide temperature range and introduce signal/noise issues when operated outside their default settings, requiring additional circuitry like temperature sensors, which increases costs.

Innovation Solution

An image sensor device with a pixel array and processing circuit that generates dark images to compute pixel statistics, determining the temperature range without a temperature sensor, and dynamically adjusts LED and biasing currents to optimize performance across various temperatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a conventional image sensor uses default current settings for LED current and biasing currents, then it operates correctly at normal temperature, but it introduces significant signal/image noises when operated at wider temperature ranges

Engineering Contradiction:

Improvetemperature range adaptabilityVSAvoidsignal/image noise

Core Design Contradiction:

Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies dynamics by making the current settings adjustable based on detected temperature ranges. The processing circuit dynamically modifies LED current and biasing current levels according to the determined temperature range, transforming a static system into an adaptive one that optimizes performance across varying temperatures without introducing noise

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes electrical parameters (current levels) based on temperature conditions. By detecting temperature range and subsequently adjusting LED current and biasing current parameters, the system adapts to different thermal environments, preventing signal degradation and noise generation that would occur with fixed default settings

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If a conventional method employs a temperature sensor to detect accurate temperature value, then it can adjust current settings for different temperatures, but it increases circuit costs

Engineering Contradiction:

Improvetemperature range adaptabilityVSAvoidcircuit cost

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent makes the pixel array multi-functional by using it for both its primary imaging function and temperature detection function. The same pixel array that captures images also generates dark images for temperature range determination, eliminating the need for separate temperature sensor circuits and reducing overall device complexity and cost

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the temperature detection function with the existing imaging functionality. By combining dark image generation (already part of the imaging pipeline) with temperature detection, the system integrates multiple functions into a unified approach, avoiding additional circuitry and reducing costs

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS10542220B2Image sensor device and method capable of detecting actual temperature range in which the image sensor device is being operated without using accurate temperature sensor

Publication Date: 2020.01.21 PIXART IMAGING INC

AI summary

A method of an image sensor device includes: using a pixel array of the image sensor device to sense and generate at least one dark image; computing pixel statistics according to the at least one dark image; and, determining which one of a plurality of temperature ranges a temperature of the image sensor device falls within according to the pixel statistics.