Smartphones have evolved dramatically since the first commercial mobile phone in 1973. From simple monochrome LCDs to today’s curved, foldable AMOLED screens, display technologies have advanced to offer better user experience, sleeker designs, and increased functionality.
With this evolution, quality control of smartphone components — especially curved cover glass — has become increasingly demanding.
One of the most challenging materials to inspect visually is black rubber.
The Challenge: Inspecting Curved Glass
Modern smartphone cover glass typically includes:
Cover glass layer
Optical adhesive
Sensor glass
LCD or AMOLED display
The production process involves several precise steps: cutting, CNC machining, polishing, ultrasonic cleaning, vacuum forming, tempering, and printing. Any defects during these steps can affect the flatness, curvature, or thickness of the screen, leading to issues like:
Touch response inaccuracies
Visible surface irregularities
Screen assembly misalignment
With the shift from flat 2D screens to 2.5D and fully 3D curved glass, inspection gets even trickier — especially when the materials are transparent or reflective.
The Solution: High-Precision Non-Contact Optical Measurement
To address these challenges, we used the HPS-CFL094 Chromatic Confocal Sensor from Hypersen to measure a sample curved glass screen.
Why Chromatic Confocal?
This technology is ideal for inspecting:
Transparent materials (glass, films)
High-reflective surfaces (mirrors, polished metals)
Curved or complex geometries
The HPS-CFL094 offers:
±62° large measuring angle
High resolution & stability
Non-contact measurement, protecting delicate surfaces
Sub-micron precision even on curved or reflective objects
Measurement Overview
Sample:
Curved smartphone cover glass
Inspection Areas:
Flat surface
Curved edge
Corner radius (R-angle)
Measured Parameters:
Flatness
Height
Curvature profile
Glass thickness
Width of the flat section
Results
Using the HPS-CFL094 sensor, we successfully captured high-resolution data of the curved glass, including:
Surface profile
Curved edge geometry
Fine variations in height and thickness
These precise results help manufacturers:
Ensure consistent touch performance
Avoid assembly issues
Maintain high visual quality standards
Product Highlights: HPS-CF Series
The HPS-CF Series is built for high-end inspection tasks requiring precision on challenging materials. It solves common inspection problems across:
Transparent objects (glass, films)
Mirror-like surfaces
Colored rubber or adhesive
Micro-defects on reflective parts
