Magnescale introduced a high resolution magnetic encoder for harsh environments

Magnescale has succeeded in the development of an exposed type magnetic linear encoder with a resolution in the nanometer range, which is ready to release to the market. This product is the world’s first exposed type magnetic encoder achieving resolution in nanometer range based on the most advanced magnetic device technology, improved magnetic medium, and the development of a new algorithm processing circuit (based upon internal investigation). This high accuracy exposed type magnetic encoder enhances the accuracy of linearity control as well as the reliability of machine tools and industrial equipment.

High resolution/high speed processing

High-speed motion and accurate position control have been sought forever by machine tools and industrial equipment which require efficiency in operation. To achieve these requirements, machine tool has transformed to full closed-loop control, increased integration of linear motors, and enabled high resolution/high-speed processing by NC machine tools. As a result, demands for high-resolution output from encoders for position control have increased further in these days.

On the other hand, for end users, the major factor reducing the efficiency of the machine is machine downtime.  Machine manufacturers employ various countermeasures, such as air purging for encoder contamination issues, which is one of the factors of  machine down. However, it is difficult to protect the encoder completely from a large amount of coolant and metal chips due to the increase in machining speed. Magnescale’s absolute magnetic encoder had been already highly recognized by various customers for its high environmental durability compared to optical encoders. At the same time, customers have been requesting encoders that can be installed closer to machining surfaces and drives in order to improve machining accuracy.  As the leading pioneer of magnetic encoders, we have developed exposed type absolute/incremental magnetic linear encoders with high accuracy and resolution which enables high reliability with compact design even in the harshest environments.

Simplistic exposed encoder

Magnetic encoders used to require an enclosed design in order to keep head and scale distance mechanically constant as the signal strength is significantly weakened against the distance between detection head and scale grating. Magnescale has investigated the possibility to increase the sensitivity of detection elements to solve this problem and to develop a simplistic exposed encoder. Consequently, Magnescale did develop a magnetic detection device for the next generation encoder using a TMR element based on the Spin-Valve principle, which is the most advanced magnetic sensor. This new encoder incorporates a low strain sensor enabling 10 times more sensitive compared to the current devices.

Magnescale has also enhanced the homogeneity of the magnetic recording medium, and increased the density of magnetic elements by 2 times compared to the current model, while optimizing the recording condition.  As a result, the output of the magnetic signal strength was doubled compared to the current model.  Moreover, Magnescale developed a high-performance processing circuit with a new algorithm that calculates positions within a signal wavelength at high accuracy and resolution, achieving position signal output at 1/10,000 accuracy.

Through elemental technology developments described herein, Magnescale has succeeded in the development and commercialization of an exposed, absolute magnetic linear encoder achieving resolution in the nanometer range.