Compared to flat (2D) screens, 3D curved glass screens go through more complex manufacturing steps, including hot bending and lamination. During the hot bending process, problems like warped edges or distortion can occur due to issues in graphite mold design or temperature control.
These defects can lead to poor bonding during the lamination step, which may result in touch screen malfunctions. That’s why it’s important to measure the contour accuracy of the 3D glass and ensure it stays within tight tolerance limits.
Key Measurement Challenges
1. Strong Reflections
3D curved glass is smooth and shiny, causing strong reflections.
Problem: Traditional methods like laser triangulation or structured light struggle with reflective surfaces.
Solution: Chromatic confocal sensors (CFS) use reflections for measurement, making them ideal for shiny glass.
2. Large Curved Angles
These glass parts often have curves with radii (R) from 20° to 40°, formed by hot bending on two or four sides.
Challenge: Measuring large tilt angles while keeping high accuracy is not easy.
Solution: Hypersen’s sensors support tilt angles up to ±25°, with measuring ranges from 1400–4000 µm. For steep curves, a measurement module is usually built using multiple sensors.
3. Inline Measurement Speed
In production, these measurements must be fast and reliable.
A full inspection of a single glass piece (length, width, height, radius, and contour) needs to be done within 3–10 seconds.
The system also must be very stable to avoid downtime and keep production running smoothly.
Why Hypersen’s CFS is a Great Fit
Excellent at handling reflective materials like glass
Supports high-speed, inline measurements
Captures accurate 2D/3D shape data in real-time
Works on transparent, multi-layered, and dark-absorbing materials
The 3D Line Confocal Sensor can scan the full surface in one pass, boosting efficiency
