An overview of Shuyu Optoelectronics transparent electromagnetic touch technology! EMR is the abbreviation of Electro Magnetic Resonance technology, and touch screens using this technology are also called electromagnetic touch screens. The principle is to transmit electromagnetic signals through an electromagnetic pen to interact with the electromagnetic induction board behind the display screen. When the electromagnetic pen is close to the touch screen, the induction board will sense the electromagnetic signal of the pen to make the induction line under the electromagnetic induction board. The change occurs, and the horizontal and vertical antenna arrays receive signals. The electromagnetic pen is the signal transmitter and the antenna array is the signal receiver. The X and Y coordinate positions of the pen are calculated through changes in magnetic flux.
1. Comparison of mainstream touch technology
Infrared: There are infrared emitting tubes and infrared receiving tubes on the four sides of the screen, corresponding to the formation of an infrared matrix that crosses vertically and horizontally. An infrared detection net is formed on the surface of the screen, and any touched object can change the infrared on the contact point to achieve touch operation.
Advantages: not interfered by current, voltage, static electricity, low price, convenient installation, excellent stability, long service life, high light transmittance (up to 95 percent ).
Disadvantages: The Red Sea market has grooves and is not beautiful, not dustproof or waterproof, and afraid of glare.
Capacitance: The four sides are plated with long and narrow electrodes, and a low-voltage AC field is formed inside. The screen is covered with a transparent film layer of metal conductive material. When the user touches the capacitive screen, the finger and the work surface will form a coupling capacitance, so the finger will suck a part of the current flowing out of the electrodes at the four corners of the screen. The controller can calculate the position of the contact point through the precise calculation of the proportions of the four currents.
Advantages: flat appearance, waterproof and dustproof, not afraid of glare interference; high commercial value.
Disadvantages: relatively high cost; relatively troublesome installation.
Electromagnetic: Relying on the magnetic field changes produced by the electromagnetic pen and the sensor during operation Define the location point.
Advantages: original handwriting, two pens and two colors, high light transmittance and resolution, Z-axis sensing capability, touch without touching. High precision.
Disadvantages: relatively high cost; need to cooperate with electromagnetic pen.
