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Our innovation in angle sensor development

POLDI is a groundbreaking, patented, miniaturizable, optical, high-precision angle sensor that is used to reshuffle the cards for numerous industries. At this point you can find out more about our angle sensor of the future.

How does POLDI work?

In its simplest form, the POLDI sensor consists of four photodiodes, each with its own polarizing filter. Each of these filters is rotated 45 degrees compared to the previous one. When polarized light falls on the sensor, it can detect the angle of polarization using Malus' law. In a typical setup, the light from an LED is sent through a polarizing filter attached to a rotating part (such as a wheel or cogwheel) onto the sensor. As the gear rotates, the angle of the polarized light also rotates.

Moving the light source or the polarization filter does not change the polarization angle of the light. As long as the polarized light hits the sensor with sufficient intensity, the sensor works. The homogeneous polarization filter can be of any size without affecting the measurement results.

Today's optical and magnetic (Hall effect) rotation angle sensors require precise adjustment (often down to a few µm). POLDI does not need this precision; a sensor that has been set up by hand and adjusted by eye often works without any problems.

There are no costs for precise assembly, no precision bearings or housings are required. POLDI is also insensitive to vibrations or shocks and can be operated in many different positions and configurations. Despite its small size and insensitivity to adjustment errors, POLDI is highly precise and outshines many more expensive systems on the market. Since POLDI is purely optical, magnetic fields and EM interference do not interfere with the measurement. Redundancy is part of the concept. Therefore dust does not pose a problem up to a certain limit.

The patented polarizing filter integrated on the chip is aligned with the highest precision during the manufacturing process and the sensor can compensate for sources of error such as ambient light and inhomogeneous lighting.


Further advantages of POLDI:

  • Works without contact - there is no friction and no wear and tear
  • Other functions can be integrated into the angle sensor (e.g. for servos, radio, etc.)
  • Flexible structure: on or next to the axis of rotation, reflective or transmissive measurement
  • Polarizing filter is “cut to fit”: no individual encoder disks are required
  • No use of rare earths

Because of the small size and the flexible configuration of POLDI and the fact that almost all movements of modern machines can be reduced to rotations along one or more axes, POLDI can be used almost everywhere where movements are monitored.

Areas of application for angle sensors: Here you will find some examples!

  • Automotive and e-bikes (BLDC commutation, steering, seats, convertible roofs, throttle valves, crankshafts)
  • Industry (machine control and monitoring, counters, encoders, servos, telemetry)
  • Smart home systems (doors, windows, shutters)
  • Entertainment (remote control, game consoles)
  • Tools (drills, chainsaws)
  • Human-machine interfaces (selection wheels, joysticks, printer)

POLDI has broad patent protection in Germany and the rest of the EU as well as in the USA, China and Japan. POLDI has aroused great interest in the industry. This gives us a large database with many customers from different industries.

We have partner agreements with customers from various industrial and automotive branches.
There is also a purchase agreement with a large Korean distributor.

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