SIG: Application of Laser Vision Measuring Machine in Glass Panel Coordinate Measurement

In the 3C electronics, optoelectronics display, and semiconductor industries, Geometric Dimension Measurement of glass panels, optical lenses, and coated glass is critical for quality control. These materials are transparent, highly reflective, fragile, and require micron-level accuracy. Traditional contact measurement methods are not only inefficient but also risk scratching the workpiece surface.

As a specialist in high-precision non-contact measurement, SIG (Sinowon) has developed an advanced laser vision measuring machine combined with a high-precision telecentric optical system. This provides a complete solution for glass panel coordinate point measurement, flatness control, and profile analysis. This article explains how SIG addresses the measurement challenges of thin, transparent parts.

Industry Pain Points: Why Transparent Glass Requires a Dedicated Solution?

Conventional profile projectors and basic OMM systems face three major technical barriers when measuring glass panels:

• Transparency Interference: Traditional light sources pass through transparent materials, blurring edge contours. Standard Vision Measuring Machines struggle to capture precise boundaries, causing Geometric Dimension Measurement data drift.
• Reflection Error: For coated or unpolished optical components, the mirror-like surface directly interferes with feature extraction by the Video Measuring System.
• Deformation and Stress: Glass is elastic. Contact probes easily deform the workpiece, distorting flatness and thickness data.

SIG solves these problems through a combination of laser-assisted autofocus, intelligent image algorithms, and polarized light modules.

SIG Solution: Core Capabilities of Laser Vision Measuring Machine

The SIG series Vision Measuring Machine is designed for high-precision optical dimension measurement, handling both 2D geometric elements and 3D spatial evaluation.

1. Coordinate Point Measurement and Accurate Positioning (Core Function)

Accurate coordinate points are essential for circuit layout and drilling positioning on glass panels. Traditional equipment often "sees through" the glass due to refraction, shifting the coordinate origin.

• Technical Breakthrough: The system integrates an intelligent laser positioning system with sub-pixel edge recognition algorithms. The laser beam actively identifies the top glass surface, and the high-resolution CCD camera accurately locks the geometric center coordinates of printed patterns, ITO circuits, or coated layers. Repeatability reaches the micron level.
• Value Delivered: Ensures precise positioning for drilling, cutting, and printing processes, effectively eliminating visual errors.

2. Geometric Dimension and 2D Profile Measurement

For outer dimensions, corner radii (R-angles), and holes in glass panels, SIG's OMM delivers powerful Geometric Dimension Measurement.

• Measurable Items: Length, width, circle diameter, slot holes, line width, arc radius, angles, and more.
• Technical Advantage: Motorized zoom lens allows fast switching from macro (overall shape) to micro (fine circuits) without lens changes. Even 0.3mm thick glass edges are clearly imaged, enabling high-precision profile comparison to quickly detect edge chipping or bumps.

3. Flatness and Height Difference Measurement (Laser / Spectral Confocal)

Flatness is often overlooked but critical for glass inspection. Poor flatness in phone cover glass or LCD substrates directly causes bonding bubbles or assembly stress.

• Non-Contact Laser Measurement: Z-axis laser scanning creates a 3D point cloud model. SIG quickly scans multiple coordinate points on the glass surface, and the software automatically fits a reference plane to calculate flatness error, achieving accuracy within ±1.2μm.
• Height Difference / Step Measurement: Also measures step heights of ink layers or bonded gaps on glass panels, outputting accurate form and position tolerances.

4. Dedicated Optimization for Coated and Transparent Glass

SIG's solution fully considers optical characteristics. We use LED ring lights, parallel profile illumination, and polarized light modules to effectively suppress reflections from coated glass surfaces, improving edge feature clarity by over 40%. Whether for high-transparency glass or AR-coated glass, measurement stability is guaranteed.

Case Study: Enabling Precision Manufacturing of Lens Modules and Displays

In smartphone camera lens module inspection, SIG's Video Measuring System plays a key role.

• Measured Object: Optical coated glass lenses.
• Challenge: Extremely small lens diameter, coated and transparent surfaces.

Results:

• Lens outer diameter and center thickness: Achieved high-resolution, non-contact, non-destructive measurement.
• Assembly concentricity: Coordinate point measurement precisely calculates gaps in multi-lens assemblies, ensuring optical axis alignment.

Summary: Why Choose SIG?

SIG's Vision Measuring Machine does more than just "see" glass — it fully supports the Geometric Dimension Measurement logic required for glass manufacturing.

• Solves Pain Points: Resolves issues of inaccurate measurement, deformation, and low efficiency on transparent glass.
• High Precision & Efficiency: Integrates optical dimension measurement with geometric dimension measurement. The software supports batch programming and SPC data analysis, enabling one-click automated inspection report generation.

If you face measurement challenges with glass panels, optical lenses, or other transparent workpieces, SIG's high-precision laser vision measuring machine is one of your ideal solutions.