Regardless of the industry, precision matters. Glass scales are the optimal choice for optical encoders if you want unmatched precision and accuracy. With decades of experience fabricating these optoelectronics for our global clients, here’s why you should choose glass.

How Glass Scales Work With Optical Encoders 

If you’re familiar with using encoders in your applications, you know they have two main components: a sensor and a scale or disc. When you implement an encoder, you do so to determine absolute or relative positioning within a system. The components do this by either reflecting or transmitting light via photoelectric scanning. 

The addition of glass scales increases the encoder’s overall precision. With fine gratings along the scale, the component moves relative to the scanning reticle, where light is modulated. The grating periods on the scale vary in length from application to application but are critically important to the entire operation’s measurement. 

Depending on which type of encoder technology you choose, the position change is detected as coherent light creates an image of the scale pattern, light is transmitted through transparent lines, or light is reflected off the scale’s lines. 

Why Choose Glass Over Other Materials? 

We’ve discussed the benefits of different encoder disc materials, which carry over to encoder scales. Of course, all materials have pros and cons, but there’s a reason why glass is the optimal choice for encoder scales. With the material’s rigidity, we can produce higher-resolution pitches on the surface with our laser-cutting technology. 

Glass also has the benefit of a lower coefficient of thermal expansion, which means a lower margin of error due to extreme temperature swings. The heat friction produced by your application’s moving parts can have wide-ranging implications on overall precision measurement.    

Although glass has a slightly higher price point than metal, it is a long-term investment for the advanced precision it achieves. At Photo Solutions, we fabricate our glass scales using soda-lime, borosilicate, and quartz substrates.

Photo Solutions’ Glass Scales 

Photo Solutions’ glass scales are manufactured for industries and applications of all kinds. With our 40 years of experience, we can fabricate scales in lengths from 2mm to 800mm but can work with your particular needs for custom tooling. 

Glass Scales

Our most common glass encoder scales are chrome-on-glass. Not only do they offer the highest degree of accuracy, but their extreme flatness allows for customer-specified etched photo patterns. To achieve this, we use CAD data and then use laser filamentation cutting for chip-free parts with tolerances of +/-5um.   

Transmissive Mode Glass Scales

We recommend our transmissive mode glass scales if you have a high-performance application. These include standard scale configuration on soda-lime glass with additional LRC if needed. 

Reflective Mode Glass Scales

We can add HRC coating with more than 60% reflectivity and an ultra-low reflective chrome on the backside if necessary. These scales are also primarily used for high-performance applications and can include transmissive and reflective patterns when specified. 

Industries We Serve 

Like encoder discs, glass encoder scales are widely used across industries to achieve highly precise measurements. From industry control to measurements on micrographs, these scales are as pervasive as they are effective. 

Motion Control/Automation 

Our scales and discs are used across the motion control and automation industries for warehouse robotics, driverless vehicles, and precision instruments. 


As a scale moves with the sensor, the optical encoder can use photosensitive sensors to determine the position change. This degree of accuracy is especially crucial for medical field applications like robotic surgery tools, where precision can be life or death. 


Photo Solutions has worked with some of the most advanced robotic companies in the industry. Our scales are applied in everything from autonomous vehicles to grocery store bots. 


For aerospace applications, precision measurement can make or break a successful mission. The reliable components we provide for this vertical allow for greater overall innovation. 


When it comes to the scientific measurement of light and distance for manufacturing, Photo Solutions’ glass encoder scales have been incorporated in stationary and portable measuring devices across industries. 

For All Your Optoelectronic Needs, Trust Photo Solutions 

When used with optical encoders, glass scales can take your application’s precision measurements to the next level. Our decades of experience allow the Photo Solutions team to fabricate custom scales for your optimal engineering solutions. Contact us for a quote!