Imaging Device Charge Synchronization for Flicker Reduction
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Solution Overview
Problem
Imaging devices struggle to capture images effectively under light sources with blinking frequencies, leading to phenomena like screen flicker and line flicker, which result in distorted or irregularly lit images due to asynchronous charge accumulation across pixels.
Innovation Solution
The imaging device employs a control unit that synchronizes the start and end of charge accumulation across all pixels using control signals, ensuring synchronicity and averaging light source variations through multiple exposure sampling, thereby reducing the influence of flickers and improving image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If exposure time is shortened to capture fast-moving subjects, then productivity is improved, but the influence of blinking light sources increases causing screen flicker and line flicker
Solution Approach 1:
The patent applies periodic action by synchronizing the exposure timing with the blinking cycle of light sources. The control unit identifies the blinking frequency and sets the exposure period to match integer multiples of this cycle, causing the sensor to capture light at consistent phases of the blinking cycle. This periodic synchronization eliminates flicker effects while maintaining short exposure times for fast-moving subject capture.
Solution Approach 2:
The patent changes the exposure timing parameters dynamically based on detected light source blinking characteristics. By adjusting the exposure start time, exposure duration, and readout timing to align with the identified blinking cycle, the system adapts to different light source conditions. This parameter optimization allows short exposure times while avoiding the harmful flicker phases.
2Manufacturing precision
If global electronic shutter is used to synchronize charge accumulation across all pixels, then manufacturing precision is improved, but the ability to capture images under blinking light sources deteriorates due to fixed exposure timing
Solution Approach 1:
The patent transforms the static, fixed exposure timing of conventional global electronic shutters into a dynamic system. The control unit continuously detects light source blinking characteristics and adjusts exposure timing parameters in real-time. This dynamic adaptation maintains charge accumulation synchronicity across pixels while simultaneously optimizing exposure phases to match blinking cycles, eliminating flicker effects that plague fixed-timing systems.
Solution Approach 2:
The patent implements feedback by using the detected blinking characteristics of light sources to continuously adjust exposure timing. The system monitors the light source behavior, identifies the blinking cycle, and feeds this information back to modify the exposure start time and duration. This closed-loop control ensures that charge accumulation remains synchronized while adapting to varying light source conditions to prevent flicker.
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 approach allows for high-quality image capture with reduced flicker effects and expanded dynamic range, ensuring synchronicity of charge accumulation and accurate representation of images even under blinking light sources.
Implementation Method 1
a plurality of pixels each including a photoelectric conversion means for accumulating electric charges generated by incident light
Data Source
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AI summary
There is provided an imaging device configured to acquire an image with the restrained influence of the blinking state of a light source while ensuring synchronicity of charge accumulation. For a plurality of pixels arranged in a plurality of rows, the imaging device intermittently turns on a first transfer switch at a same timing a plurality of times to transfer electric charges from a photoelectric conversion unit to a holding unit a plurality of times. The imaging device row-sequentially turns on a second transfer switch of the plurality of pixels to transfer the electric charges transferred a plurality of times to and held by the holding unit, to an amplifying unit on a row basis.