In the field of optical manufacturing, lenses serve as core components whose precision in all parameters directly impacts imaging quality and equipment performance. Among these, measuring the center thickness of lenses is particularly critical yet challenging. Traditional measurement methods often prove inadequate when confronted with the complex structures and high-precision demands of lenses.

I. Center Thickness Measurement of Lenses: A Tough Nut to Crack

1. Lens shapes vary widely, ranging from simple plano-convex and plano-concave designs to complex aspheric configurations. Each shape demands extremely precise positioning of measurement points, as even slight deviations can distort results.

2. Lens materials vary significantly. Different materials like glass and plastic exhibit distinct optical properties, significantly affecting the reflection and refraction of measurement light, thereby increasing the complexity of signal processing.

3. Under high-precision requirements, even minute measurement errors can substantially impact lens optical performance. Traditional contact-based measurement methods risk damaging lens surfaces, while non-contact methods are susceptible to interference from ambient light, surface roughness, and other factors, resulting in poor stability.

II. Spectral Confocal Displacement Sensor: The “Jack-of-All-Trades” in Measurement

The core principle of spectral confocal displacement sensors is based on spectral encoding and confocal imaging technology. By measuring the spectral distribution of reflected light, it precisely determines the distance between the surface of the measured object and the sensor. This principle endows it with numerous significant advantages:

1. Ultra-high precision: Spectral confocal technology achieves sub-micron measurement accuracy, far surpassing traditional methods. For the critical parameter of lens center thickness, this exceptional precision ensures highly reliable results, providing robust assurance for lens quality control.

2. Non-contact Measurement: The sensor requires no physical contact with the lens, eliminating potential surface scratches and deformation associated with contact-based methods. This is particularly significant for high-precision, high-value lenses, effectively preserving their integrity and optical performance.

3. Strong Adaptability: Spectral confocal displacement sensors effortlessly handle lenses of any complexity or material composition. Its measurement points can be flexibly positioned to adapt to surfaces with varying curvatures and materials, ensuring accurate data acquisition across diverse measurement scenarios.

4. Strong Interference Resistance: Advanced signal processing algorithms and optical design enable the sensor to effectively suppress interference factors such as ambient light and lens surface roughness. It maintains measurement stability and consistency even in complex industrial environments.

5. Rapid Measurement: The spectral confocal displacement sensor features high-speed data acquisition and processing capabilities, enabling the scanning of numerous measurement points within a short timeframe and significantly boosting measurement efficiency. This is particularly significant for quality control in large-scale lens production, contributing to enhanced overall production efficiency.

In actual production, the optical confocal displacement sensor's opposing-beam configuration enables real-time online measurement of lens center thickness. This approach also enhances measurement accuracy to within 0.1 micrometers and boosts measurement efficiency by several times.