Development and verification of a snapshot dental intraoral three-dimensional scanner based on chromatic confocal imaging

Abstract

We describe the development and verification of an optical, powder-free, intraoral scanner based on a chromatic confocal imaging system, which has been realized in a single-shot multifocal approach. The system is based on a combination of micro-optical and dispersion optical elements. The methodology of recording and analyzing the acquired data are discussed in detail. A proof of concept with the application in intraoral scanning is provided. According to the current findings, the measurement uncertainty, scan speed, and overall performance of the device can well compete with the state-of-the-art of commercially available intraoral scanners.

Spectral optimization and influence of noise for spectrometer free areal chromatic confocal metrology

“…Finally, a optical spectral analysis unit (OSAU) will be utilized to simultaneously analyse the spectral irradiance distribution of the reflected light for each of the measurement channels, without the need for an additional spatial dimension on the imaging sensor. [2][3][4] [5] The diverging light of a poly-chromatic broadband light source (LS), ideally a point source, is being collimated by a achromatic collimation optic (L1) and passes through a spectral and polarization filter (F1). After the collimation, the light passes through a polarizing beam-splitter (PBS) and gets separated into multiple converging beams by the micro-lens array (MLA) therefore generating the point grid pattern in its focal plane.…”

Advantages and limits of spectrometer free areal chromatic confocal metrology

“…In contrast to areal CCM sensors, point and line CCM sensors are used in different medical, research and industry applications. [3][4][5][6] The ChromaCAM system uses a single-shot technique based on the intensity measurement of two CMOS sensors and a simple image processing algorithm. These two characteristics combined enables this sensor to measure the surfaces of various materials at high frame rates.…”

Enhancing precision of chromatic confocal measurement through linear interpolation based centroid algorithm

“…This greatly improves measurement efficiency while maintaining high resolution [1]. Therefore, CCM has a promising application in realtime scanning [2], industrial rapid inspection [3,4], noncontact measurement [5][6][7] and other scenarios with high requirements for measurement efficiency and precision.…”