Dual LED Image Capture for Motion Blur Reduction
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Solution Overview
Problem
Conventional digital cameras struggle to capture sharp images of moving objects in dim or poorly-lit conditions due to limitations in the power and duration of light pulses from visible-spectrum LEDs, which results in blurred and unsatisfactory images.
Innovation Solution
The method involves generating a first visible-spectrum light pulse for a longer duration to capture a full-color image, and a second high-intensity infrared light pulse lasting at most 10% of the first pulse's duration to capture a monochrome 'motion-freeze' image. These images are then processed to combine color information with motion-freeze data, reducing or eliminating motion blur.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the LED current is increased to generate higher power burst for shorter time, then the flash intensity is improved, but the light output decreases due to the Auger effect
Solution Approach 1:
The patent divides the illumination task into two separate light sources: a visible-spectrum LED for color illumination and an infrared LED for motion-freeze illumination. This segmentation allows each LED to operate in its optimal performance range without the Auger effect limiting the overall system capability.
Solution Approach 2:
The patent changes the wavelength parameter of the light source by introducing an infrared LED that operates at a different spectral range than the visible LED. This parameter change allows the infrared LED to deliver high power bursts without being constrained by the Auger effect that limits visible-spectrum LEDs.
2Loss of information
If the visible light pulse duration is extended to capture color information, then the color image quality is improved, but motion blur increases
Solution Approach 1:
The patent segments the imaging process into two parallel paths: one capturing color information with extended duration and another capturing sharp monochrome information with short duration. The final image combines both, eliminating motion blur while preserving color.
Solution Approach 2:
The patent merges the results from two separate imaging processes: the color image from the visible LED and the sharp monochrome image from the infrared LED. This combination produces a final image that has both color information and sharp edges without motion blur.
3Device complexity
If a single light source is used for both color and motion-freeze imaging, then the device complexity is reduced, but the image quality in low-light conditions deteriorates
Solution Approach 1:
The patent implements multi-functionality by using two LEDs that can operate independently or together. The visible LED provides color illumination, the infrared LED provides motion-freeze capability, and both can be used simultaneously to achieve superior image quality in various lighting conditions.
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 enables the capture of high-quality, sharp images of moving subjects in low-light conditions by effectively freezing motion and combining it with color information, resulting in reduced or eliminated motion blur.
Implementation Method 1
A visible-spectrum LED of a flash module is generally based on an (Al)InGaN die in which the optical power is converted into broad-spectrum visible light by stacking appropriate phosphors on top of the die
Implementation Method 2
driving a second light source to generate a second light pulse during the first light pulse to illuminate the scene
Implementation Method 3
operating an image sensor to record a visible-spectrum image of the scene illuminated by the first light pulse
Implementation Method 4
operating an image sensor to record a monochrome image of the scene illuminated by the second light pulse
Data Source
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AI summary
The invention describes a method of obtaining a digital image (Mopt) of a scene (D), which method comprises the steps of driving a first light source (11) to generate a first light pulse (FRGB) to illuminate the scene (D), which first light pulse (FRGB) is a visible-spectrum light pulse extending over a first duration (tRGB); arranging an image sensor (S, S1) to record a visible-spectrum image (MRGB) of the scene (D) illuminated by the first light pulse (FRGB); driving a second light source (12) to generate a second light pulse (Fmono) during the first light pulse (FRGB) to illuminate the scene (D), such that the duration (tmono) of the second light pulse (Fmono) is at most 10% of the duration (tRGB) of the first light pulse (FRGB), and such that the intensity (Nmono) of the second light pulse (Fmono) exceeds the intensity (NRGB) of the first light pulse (FRGB) by at least 100%; arranging an image sensor (S, S2, SIR) to record a monochrome image (Mmono) of the scene (D) illuminated by the second light pulse (Fmono); and performing image processing steps on a visible-spectrum image (MRGB) and a monochrome image (Mmono) to obtain the digital image (Mopt) of the scene (D).