Image Sensor Timing for PWM Light Banding Reduction
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Solution Overview
Problem
Electronic image sensors in medical environments, such as surgical booms, experience visual artifacts due to the lack of synchronization with the varying frequencies of pulse-width modulated light sources, leading to issues like banding in captured images.
Innovation Solution
The image capture device employs a controller to adjust gain, crop and resize images, and utilize tunable components to compensate for brightness changes and synchronize with pulse-width modulated light sources, reducing visual artifacts through methods like frame rate adjustment, per-line gain or offset adjustments, and binocular overlap.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If electronic image sensors operate under pulse-width modulated light sources with varying frequencies, then the imaging system can adapt to different lighting conditions, but visual artifacts such as banding appear in captured images
Solution Approach 1:
The patent applies dynamics by making the image sensor's integration time adjustable and synchronizing it with the pulse-width modulated light source frequency. The system dynamically adapts the sensor timing parameters to match the lighting conditions, allowing the imaging system to work effectively under varying PWM frequencies while eliminating banding artifacts through proper synchronization.
2Device complexity
If image sensors use fixed integration time, then the device complexity is reduced, but the ability to synchronize with varying light source frequencies is lost
Solution Approach 1:
The patent applies preliminary action by detecting the pulse-width modulated light source frequency before capturing images and pre-adjusting the image sensor's integration time and other timing parameters to match the detected frequency. This preliminary synchronization ensures that when imaging begins, the sensor is already properly configured to work with the specific light source, eliminating banding artifacts without requiring complex real-time adjustment mechanisms during image capture.
3Object-affected harmful factors
If the image sensor integration time is adjusted to synchronize with PWM light sources, then visual artifacts are reduced, but the device complexity increases
Solution Approach 1:
The patent applies feedback by implementing a system that continuously detects the pulse-width modulated light source frequency and automatically adjusts the image sensor's integration time and timing parameters in response. The feedback loop monitors the lighting conditions and dynamically configures the sensor to maintain optimal synchronization, thereby reducing visual artifacts while automating the complexity management through intelligent control algorithms.
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 provides consistent, high-quality images by minimizing visual artifacts, enabling effective digital magnification and 3D visualization under pulse-width modulated illumination.
Implementation Method 1
Each pixel in the image sensor integrates light for a specified integration time to produce image data
Data Source
AI summary
A system for reducing artifacts when imaging under pulse-width modulated illumination. A controller captures, with an image sensor, images as frames of a video of a target in an environment in which the target is illuminated by a pulse-width modulated light source. In doing so, the controller sets a first parameter for the image sensor as a function of a light pulsation period of the pulse-width modulated light source to reduce artifacts in the images associated with the pulse-width modulation of the light source. Further, the controller determines whether residual banding artifacts resulting from the pulse-width modulation of the light source are unacceptable in the images captured with the image sensor. Additionally, the controller performs, in response to a determination that residual banding artifacts are present in the images, image processing to correct the residual banding. The system outputs the resulting images with reduced artifacts for viewing by a user.