Working with a polarization filter: Essential in modern production processes

What is a polarization filter?

A polarization filter is an optical tool used to minimize reflections and glare. The filter controls how light is reflected and captured by a camera system. This is especially useful in situations where products have reflective surfaces, such as glossy packaging, plastic, or metal labels.

When scanning labels or other visual data in a production environment, lighting can often reflect off the product’s surface. This leads to white spots or distortions in the image, making data difficult to read. A polarization filter solves this problem by:

• Directing the light from the illumination at a specific angle.
• Capturing only the reflected light at a different angle through the lens.

The result? 

Stable, reflection-free images that are consistently and accurately read.

How does a polarization filter work?

The concept behind a polarization filter sounds more complex than it is. Here’s how it works in a production environment: 

• Directed light emission: The system’s lighting is adjusted with a polarization filter that emits light at a specific angle. This prevents light from reflecting straight off the surface and back into the lens.
• Filtered light capture: The cameras in the system are equipped with a polarization filter that only captures light entering at a specific angle. This filters out reflections and glare from the image.
• Accurate reading: With less distortion in the image, the camera software can effortlessly and accurately read labels, barcodes, and other visual data.

Real-world example: A customer producing soft drink bottles frequently faced reflections on glossy labels under bright production line lighting. As a result, barcodes were not always read correctly, causing delays. By adding a polarization filter, reflections were completely eliminated, and the line ran smoothly without errors.

Benefits of a polarization filter

Using a polarization filter offers a wide range of advantages for companies with a production department:

• Improved reading accuracy: Labels and barcodes are read much more accurately, even on glossy surfaces.
• Stable performance at high speeds: In fast production lines, stability is crucial. Polarization filters minimize disruptions, preventing delays.
• Cost savings: Fewer errors mean less rework and waste. Additionally, a polarization filter extends the lifespan of your camera system by ensuring consistent performance.
• Flexibility: Whether working with plastic, glass, metal, or another reflective material, a polarization filter adapts and delivers reliable results.
• Professional end result: A reflection-free image not only looks better but also conveys professionalism to customers and partners.

Practical applications

Polarization filters are widely applicable and can make a difference in various sectors:

• Packaging industry: Reading barcodes on glossy packaging, such as candy wrappers or beverage bottles.
• Food industry: Quality control on labels or detecting defective packaging.
• Pharmaceutical sector: Reading serial numbers and batch codes on medications, where accuracy is crucial.
• Logistics: Scanning labels on boxes or pallets in a warehouse environment.

Polarization filters and vision systems from Promation

At Promation, we understand the importance of optimizing vision systems. That’s why we use Cognex cameras combined with high-quality polarization filters. These systems are specifically designed to tackle the challenges of modern production environments.

Why choose Promation?

• Customized solutions: Every system is tailored to your specific needs.
• Efficiency: Our vision systems are optimized for speed and accuracy.
• Expertise: As specialists in automation, we have years of experience in implementing smart solutions.

Practical example: A customer in the cosmetics industry struggled with reading codes on glossy perfume bottles. Thanks to our vision systems with polarization filters, reading accuracy improved from 80% to 99.9%, leading to significant improvements in their logistics processes.