Q&A

Single side reading Read the front side of the OMR form
Dual Side Reading Read both sides of the OMR form


: Each sensor can recognize Marks and Timing Marks directly.
Every marks need to print on the same position of reading sensors.

Type of sensor Wave length Mark Implements Dropout color Readable color
Infrared sensor(IR) 940nm Pencil Colors other than readable color Black, Blue, Pigments
Visible sensor (VR) 660 nm Pencil + Pen Red , Orange , Pink Black, Blue
Read pencil marks only
Infrared light can not see by naked eye.


Infrared sensor(Pencil read sensor)



  • Image : Infrared light can not see by naked eye.

  • Image : Dropout mark frames

Red lights onto mark frames



  • Example: Red , Orange, and Pink are dropout by visible red light

  • Blue line can not drop out by the visible red light