Imaging System Modulating Light Frequency to Reduce Ambient Interference
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Solution Overview
Problem
Traditional optical cameras face challenges in imaging surfaces with weak light, reflective, transparent, or dark surfaces due to interference from external factors and limited signal-to-noise ratio, leading to suboptimal imaging quality.
Innovation Solution
An imaging system that includes a light source modulator, objective lens, sensor array, and sensor read-write module, which modulates the light source to a preset frequency, converts optical signals into analog alternating current electrical signals, amplifies and digitizes these signals, and displays images, thereby reducing the influence of external ambient light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional optical cameras measure direct current signal from sensor array, then imaging process is simple, but signal-to-noise ratio is limited and imaging quality deteriorates in weak light field
Solution Approach 1:
The patent applies periodic action by modulating the light source at a specific frequency and using synchronous detection to extract the modulated signal from noise. The light source is switched between on and off states periodically, and the sensor array captures signals synchronized with this modulation, enabling differentiation between target signal and ambient noise through frequency-based separation.
Solution Approach 2:
The patent introduces an intermediary AC coupling mechanism between the sensor array and signal processing stage. The direct current signal from the sensor is converted to AC signal through coupling with the modulated light source frequency, allowing noise filtering through AC-coupled amplification and synchronous detection circuits that reject DC components and low-frequency noise.
2Object-affected harmful factors
If traditional optical cameras capture images in weak light field, then imaging process is straightforward, but external environmental factors cause interference and imaging quality deteriorates
Solution Approach 1:
The system uses periodic modulation of the light source at a frequency distinct from ambient light sources. By synchronizing the sensor readout with this modulation frequency and using AC coupling, the system selectively amplifies only the modulated signal while rejecting unmodulated ambient light interference, thereby improving reliability in electrically noisy environments.
Solution Approach 2:
The patent implements feedback through synchronous detection where the modulated light source signal serves as a reference for the detection circuit. The system continuously compares the sensor output with the reference modulation signal, using phase-sensitive detection to extract the target signal while rejecting signals that are not synchronized with the reference, thereby providing active suppression of external interference.
3Illumination intensity
If camera sensor array directly measures reflected optical signal, then imaging process is simple, but reflective surfaces cause specular reflection and supersaturation
Solution Approach 1:
The patent uses periodic modulation of the light source intensity to encode the illumination pattern. By modulating at high frequency and using AC coupling in the detection circuit, the system can distinguish between specular reflection (which maintains the modulation pattern) and diffuse reflection or ambient light (which does not), enabling selective processing to avoid supersaturation from strong specular highlights.
4Measurement precision
If traditional optical cameras image transparent or translucent surfaces, then imaging process is direct, but optical penetration causes weak signal and poor imaging quality
Solution Approach 1:
The system applies periodic modulation to the light source and uses synchronous detection to extract weak signals from transparent surfaces. The AC coupling mechanism amplifies only the modulated signal component, enabling detection of weak reflections from transparent materials while rejecting the overwhelming majority of transmitted light and ambient noise, thereby improving signal strength without proportionally increasing processing complexity.
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 system improves imaging quality by enhancing the signal-to-noise ratio and reducing external light interference, enabling clearer image capture of target objects with improved resolution and reduced specular reflection and light absorption issues.
Implementation Method 1
a light source modulator configured for modulating the light source to a preset frequency
Implementation Method 2
a sensor array configured for converting the received optical signal into an analog electrical signal
Data Source
AI summary
Disclosed are an imaging system and an imaging method thereof. The system includes a light source, a light source modulator, an objective lens, a sensor array, a sensor read-write module and an imaging display module connected with the sensor read-write module. The light source modulator is configured for modulating the light source to a preset frequency; the objective lens is configured for imaging an optical signal reflected by a surface of a target object on the sensor array; the sensor array is configured for converting the received optical signal into an analog alternating current electrical signal; the sensor read-write module is configured for amplifying the analog alternating current electrical signal and extracting a target signal, converting the target signal into a digital signal and storing the digital signal; and the imaging display module is configured for restoring and displaying an image of the target object according to the digital signal.