Magnescale Co., Ltd. || Magnescale(R), Laserscale(R), Digital Gauge

Oct. 20th, 2014

High-accuracy, exposed, absolute/incremental Magnetic linear encoder from Magnescale
High resolution magnetic encoder with stronger resistance to harsh environments

Magnescale Co., Ltd. has succeeded in the development of an exposed type magnetic linear encoder with the resolution in 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 as well as by improvement of magnetic medium, and the development of a new algorithm processing circuit (based upon internal investigation). The new encoder provides high reliability under compact size by an exposed type design which is consisted of less mechanical components such as protective cover, as compared to enclosed type linear encoders.

This high accuracy exposed type magnetic encoder enhances accuracy of linearity control as well as reliability of machine tools and industrial equipments.

The technical details will be announced during JIMTOF2014 at Tokyo Big Sight (Oct. 30 to Nov. 4, 2014)

Exposed absolute magnetic linear encoder, IP67 rating (Upper image)
Exposed incremental magnetic linear encoder, IP65 rating, with small head (Lower image)

High speed motion and accurate position control on machine tools and industrial equipments are everlasting things to be improved which require the 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 CNC machine tools. As a result, demands towards high resolution output from encoders for position control have increased further in these days.

On the other hand, major factor reducing its efficiency at the end user is machine downtime. Machine manufacturers employ various countermeasures, such as air purging for encoder contamination issues, which is one of the factors of the machine down. However, it is difficult to protect the encoder completely from large amount of coolant and metal chips due to the increase of machining speed. Magnescale’s absolute magnetic encoder had been already highly recognized by various customers on 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 provides high reliability with compact sized design even in the harshest environments.

Although magnetic encoder is highly resistant to harsh environment, high resolution performance was only realized with enclosed design that enables to keep constant clearance between scale and head as the distance is quite critical to gain the sufficient signal strength. 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 TMR element based on the Spin-Valve method, which is the most advanced magnetic sensors. This new encoder incorporates a low strain sensor enabling 10 times higher sensitivity compared to the current devices.

Optimization of the recording condition as well as improvement of magnetic medium consistency with two times or more the density of the material has doubled the output signal strength compared to 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 Co., Ltd. has succeeded in the development and launch of an exposed, absolute magnetic linear encoder achieving resolution in the nanometer range with following features;

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Main Specification

Absolute Type Incremental type
Effective length (mm) 20~4,000
Accuracy (μm) ±(1.5+1.5L/1000) ±5, ±10, ±15
Resolution (μm) 0.005/0.01/0.05/0.1/0.5 0.01/0.05/0.1/0.5
Max. response speed (m/min) 200
Vibration resistance (m/s2) 250 200
Protection grade   IP67 IP65
Output signal   Correspond to various serial protocol interface Correspond to various serial protocol interface
A/B quadrature output signal

For more information contact the President's Office at info-mgs@magnescale.com