Ultra-small, low-cost, and simple-to-control PSP projector based on SLCD technology

Area of Science:

• Optics and Photonics
• Metrology and Measurement Science
• Materials Science

Background:

• Growing demand for compact, affordable, high-accuracy 3D shape measurement devices in industry and consumer electronics.
• Phase shifting profilometry (PSP) offers high accuracy and resolution but requires specialized projectors.
• Existing projector technologies struggle to meet simultaneous requirements for ultra-small size, low cost, and simple control.

Purpose of the Study:

• To present a novel technique for fabricating ultra-small, low-cost, and easily controllable PSP projectors.
• To address the limitations of current projection methods in phase shifting profilometry.
• To enable widespread adoption of advanced 3D shape measurement in various sectors.

Main Methods:

• Utilized segmented liquid crystal display (SLCD) technology for pattern generation.
• Employed a cylindrical lens as the projection lens.
• Developed four specific filled binary patterns on the SLCD to generate phase-shifted sinusoidal fringes.

Main Results:

• The SLCD device successfully displayed four sets of binary patterns, each producing a sinusoidal fringe.
• All generated sinusoidal fringes satisfied the required four-step phase shift relation.
• 3D shape measurement experiments validated the performance and accuracy of the fabricated projector.

Conclusions:

• The proposed technique effectively produces ultra-small, low-cost, and simple-to-control PSP projectors.
• The use of SLCD technology is a viable solution for next-generation 3D shape measurement systems.
• This advancement facilitates the integration of high-performance 3D measurement into compact electronic devices.