Solid-State Imaging Pixel Timing for Moving-Edge Artifact Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing solid-state imaging devices using near-infrared sensors for driver monitoring systems face issues with artifacts at the edges of moving subjects due to large time differences between IR images, which are captured with and without a pulse wave, leading to background light interference.
Innovation Solution
A solid-state imaging device with pixels that include a photoelectric converter and operation processors to add and subtract photon signals during different periods of a frame, using pulsed light to minimize time differences and reduce background light influence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If two IR images are captured with a large time difference (one with pulse wave on, one with pulse wave off), then background light influence can be removed by subtraction, but artifacts occur at the edge of moving subjects
Solution Approach 1:
The patent applies periodic action by dividing the frame period into multiple sub-periods (first period, second period, third period) within which pulsed light is alternately turned on and off. This allows background light removal through subtraction while minimizing time differences within each sub-period, thereby preventing artifacts at moving subject edges.
2Object-affected harmful factors
If IR images are captured sequentially with pulse wave on and off, then background light can be removed, but the time difference causes misalignment when subjects move
Solution Approach 1:
The patent implements periodic action by alternately turning on and off the pulsed light during different periods within a single frame period. This enables background light removal while keeping the time interval between corresponding pixels minimal, thus preventing temporal misalignment artifacts when subjects move.
3Loss of time
If a single frame period is used for both pulsed light and external light capture, then processing time is reduced, but background light removal becomes more complex
Solution Approach 1:
The patent applies segmentation by dividing the frame period into multiple distinct periods (first period for pulsed light + external light, second period for external light only, third period for additional pulsed light + external light). This temporal segmentation simplifies the signal processing logic within each period while achieving comprehensive background light removal across the entire frame.
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 effectively suppresses artifacts and removes background light influence by processing photon signals within shorter time intervals, improving image quality and simplifying system configuration.
Implementation Method 1
a photoelectric converter configured to detect photons and to output a signal corresponding to a number of photons that are detected
Data Source
AI summary
A solid-state imaging device includes: a plurality of pixels, wherein each pixel of the plurality of pixels includes: a photoelectric converter configured to detect photons and to output a signal corresponding to a number of photons that are detected; and at least one operation processor configured to add an output signal of the photoelectric converter for pulsed light and external light which are received by the pixel in a first period in one frame period, and to subtract the output signal of the photoelectric converter for the external light received by the pixel in a second period in the one frame period.