Although the scanning tip of an intraoral scanner is only the size of a finger, it houses a complex optical lens system. The design and manufacturing precision of this system directly determine imaging quality.
Composition of the Lens System
Projection lens group: Projects the light source (pattern on a DMD chip or laser) onto the tooth surface. Typically composed of 4–6 lenses, including aspheric elements to correct distortion.
Imaging lens group: Collects light reflected from the tooth surface and focuses it onto the CMOS sensor. A large aperture (F/2.0–F/2.8) is required to ensure sufficient light intake.
Beam-splitting elements: Polarizers, prisms, dichroic mirrors, and similar components that separate light of different wavelengths or polarization directions.
Mirrors and prisms: Fold the optical path within the confined space of the scanning tip, enabling the device to maintain a slender form factor.
Protective window: The front-most window lens of the scanning tip, which faces the oral environment directly. It must withstand high-temperature, high-pressure sterilization, resist scratches, and prevent fogging.
Miniaturization Engineering Challenges
The entrance height of the scanning tip is only 15–20 mm, yet it must accommodate the projection optical path, imaging optical path, illumination LEDs, and sometimes dual cameras-resulting in extremely tight spatial constraints.
Lenses have small apertures but demand high precision, with surface form accuracy typically at the nanometer level.
The lens assembly must endure 134 °C autoclave sterilization and repeated thermal cycling without optical axis shift.
Scanning tip weight must be controlled within 200 g, placing strict requirements on lens materials (lightweight optical plastics or glass) and structural design.
Lens assembly requires active alignment processes that adjust and fix lens positions at micron-level precision.
Impact of the Lens System on Scanning Quality
Distortion: Lens distortion introduces geometric measurement errors that require precise calibration and software correction.
Depth of field: The designed depth of field determines the working distance range of the scanning tip.
Resolution: The modulation transfer function (MTF) of the lens affects fine-detail discrimination capability.
Stray light: Internal reflections within the lens can produce glare and ghost images; these are suppressed through coatings and aperture design.
The scanning tip is one of the most expensive consumables of an intraoral scanner (priced between approximately USD 197–1,487). The primary reason is the high manufacturing cost of this precision optical system.
At Aident Technology, the AI-30 intraoral scanner series is engineered with a highly optimized optical system that balances miniaturization, performance, and durability. With an ultra-lightweight body of 156–198 g, ≥30 frames per second, ≤10 μm accuracy, powder-free true-color scanning, and intelligent anti-fog heating, the AI-30 delivers reliable clinical imaging while maintaining a compact, ergonomic scanning tip.
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Contact Aident for OEM/ODM collaboration, wholesale pricing, or a live demonstration and experience how advanced optical engineering translates into accurate, efficient digital impressions.
