Hanvon Electromagnetic Resonance Touch (ERT) module utilizes electromagnetic resonance technology to implement powerful non-contact handwriting input for digital devices, such as E-book readers, GPS navigation, MP4 players, MID, Tablet PCs, Net Books, Notebook Computers, Mobile Phones, etc.
  The electromagnetic pen is very convenient to use, requiring no batteries or cords to operate.  Compared to resistive and capacitive touch technology, the ERT module eliminates surface stains and reduces erroneous input, lengthening the operating life of the electronic device in which it’s embedded.  The module is designed such that it has no negative impact on the device’s display, making it perfect for devices like the e-book reader.
 
   The ERT module, in conjunction with Hanvon’s Handwriting Recognition software, provides support for multiple languages, multiple handwriting styles and Chinese-English-Arabic number and character recognition.
 
 
Structure:  
Hanwang ERT components consists of ERT pen, Sensor board, Shield plate and control unit. Its structure is showing below:  
 

 
Technical Principle:  
ERT pen draws tiny energy from electromagnetic field transmitted by sensor board. The control board read information of ERT pen such as position, movement and pressure through the resonance between ERT pen and sensor board. Magnetic field noise generated by mother board or user’s application board can be reduced by shield plate.

ERT unit do not require any cable or built-in battery-based power at all, which bother users a lot.
 
 
ERT unit employs synchronized exciting- receiving method, which avoid the frequently switch between exciting and receiving. Higher responding speed can be achieved with less power consumption. 电磁感应组件采用同步发射－接收方法,从而可
    Unique low duty cycle square wave exciting method is employed in ERT unit.
The induction circuit in ERT pen utilizes frequency selection to stir mutual inductance at higher order harmonics, sharper responding is achieved.