Structured Light Imaging Device Beam Amplitude Modulation
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Solution Overview
Problem
Structured light scanning technologies face interference issues due to changes in brightness patterns, affecting depth calculation accuracy.
Innovation Solution
A structured light imaging device with a projector, image sensor, and processing circuit that includes a diffractive optical element and beam homogenizer, where the processing circuit controls the beam's amplitude during sensing to reduce interference, using a processor to alter the beam's amplitude in a random manner at a high frequency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a special light pattern is projected onto an object for depth calculation, then depth measurement capability is enabled, but the brightness pattern becomes disturbed by interference factors affecting measurement precision
Solution Approach 1:
The patent applies dynamics by modulating the amplitude of the projected light beam during the sensing period. The processing circuit alters the beam amplitude dynamically, causing the light pattern to change over time. This dynamic modulation allows the system to distinguish the projected pattern from static interference, thereby improving depth measurement precision despite the presence of interference factors.
Solution Approach 2:
The patent implements periodic action through amplitude modulation of the light beam at specific frequencies during the sensing period. By varying the beam amplitude periodically or randomly, the system creates time-varying signal characteristics that enable differentiation between the projected pattern and interference, thus enhancing measurement accuracy in noisy environments.
2Reliability
If the beam amplitude is altered during sensing period, then interference is reduced and signal-to-noise ratio is enhanced, but device complexity increases due to additional control requirements
Solution Approach 1:
The processing circuit performs multiple functions: it generates the special light pattern, modulates the beam amplitude, controls the projection timing, and processes the captured images for depth calculation. By making the processing circuit multi-functional, the patent avoids adding separate dedicated hardware for amplitude modulation, thereby enhancing signal-to-noise ratio without proportionally increasing device complexity.
Solution Approach 2:
The system uses its own processing circuit to generate and control the amplitude modulation of the projected beam, rather than requiring an external dedicated modulator. The processing circuit leverages its existing computational and control capabilities to perform amplitude modulation as part of its normal operation, thus improving reliability while minimizing additional 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
This approach enhances the signal-to-noise ratio, leading to improved depth calculation accuracy by minimizing interference effects and reducing standard variation in measured depths.
Implementation Method 1
a projector (110) including a diffractive optical element (230)
Implementation Method 2
a beam homogenizer (221), where the processing circuit (130) controls the beam (111) amplitude during sensing
Data Source
AI summary
The structured light imaging device includes a projector including a diffractive optical element, an image sensor, and a processing circuit. The processing circuit is configured to control the projector to emit a beam having a special pattern, and alter an amplitude of the beam during a sensing period. The image sensor is configured to capture an image corresponding to the beam during the sensing period, and transmits the image to the processing circuit. The processing circuit calculates a depth according to the image and a predetermined image having the special pattern. Therefore, the interference phenomenon is reduced.