Overview of optoelectronic transparent electromagnetic touch technology! EMR is the abbreviation of Electro Magnetic Resonance technology, and the touch screen using this technology is also known as the electromagnetic touch screen. The principle is to transmit electromagnetic signals through an electromagnetic pen and interact with the electromagnetic induction board behind the display screen. When the electromagnetic pen is near the touch screen, the induction board will sense the electromagnetic signal of the pen, so that the induction line under the electromagnetic induction board changes, and receives signals according to the horizontal and vertical antenna arrays. The electromagnetic pen is a signal transmitter (transceiver), and the antenna array is a signal receiver. The X and Y coordinate position of the pen is obtained by calculating the change of magnetic flux.
Transparent electromagnetic antenna board
1. Comparison of mainstream touch technology
Infrared: The four sides of the screen have infrared transmitting tubes and infrared receiving tubes, corresponding to the formation of horizontal and vertical cross infrared matrix. An infrared detection network is formed on the surface of the screen, and any touching object can change the infrared on the contact point to achieve touch operation.
Advantages: free from current, voltage, static interference, low price, easy installation, excellent stability, long service life, high transmittance (up to 95%).
Disadvantages: The Red Sea market, with grooves is not beautiful, not dustproof and waterproof, afraid of strong light.
Capacitor: The four sides are plated with narrow electrodes, forming a low-voltage AC field inside. The screen is covered with a transparent film of metallic conductive material. When the user touches the capacitive screen, a coupling capacitor is formed between the finger and the working surface, and the finger absorbs some of the current flowing from the electrodes at the four corners of the screen. The controller can calculate the position of the contact point by precise calculation of the ratio of the four currents.
Advantages: smooth appearance, waterproof and dustproof, not afraid of strong light interference; High commercial value.
Disadvantages: relatively high cost; Installation is relatively cumbersome.
Electromagnetic: rely on the magnetic field changes generated by the electromagnetic pen and the sensor in the operation process to distinguish, the electromagnetic pen is the signal transmitter (transceiver), the antenna board is the signal receiver (receiver), when the magnetic flux changes when the induction is close, and then the calculation defines the position point.
Advantages: Original handwriting, double pen, double color, high light transmittance and resolution, with Z-axis sensing ability, can be touched without touching. High precision.
Disadvantages: relatively high cost; Need to work with the electromagnetic pen.
Second, core competitiveness
Electromagnetic core technology
Third, electromagnetic classification
01 Electromagnetic Pen
According to the electromagnetic pen, it can be divided into active pen and activated pen.
(1) Active pen - active electromagnetic pen
The active pen emits electromagnetic signals through the built-in battery, whether the electromagnetic pen is near the electromagnetic screen is sustainable when used, the electromagnetic signal is strong, the response speed is faster, the size can be larger, the power consumption is low, and the anti-interference ability is stronger, but the electromagnetic pen cost is high, and the battery needs to be installed or charged. Large sizes can only be used with active pens. Pen size is limited by battery size, weight.
(2) Activated pen - passive electromagnetic pen
Passive electromagnetic relative active power consumption is high, can only do small size, the maximum can be 22 inches, corner signal is weak, can only single stroke control, the advantage is that the electromagnetic pen does not need power, portable device stylus can do very small. Passive pens have higher requirements on the antenna plate than active pens, and active pens are more expensive than passive pens in the case of the same small size. Passive electromagnetic pen is not close to the electromagnetic screen, can not receive electromagnetic energy, with the distance, the signal is weaker, but because no battery, light, no requirements for the pen, for 20 inches below, more advantages. There are too many small sizes on the market. Such as e-commerce signature board, pos machine, e-reader and so on.
According to the material, can be divided into transparent and non-transparent, the former can be applied to the straight down backlight and side into the backlight; The latter can only be applied to side-entry light sources.
(1) Side entry backlight
Side light type LED backlight, is the LED grain configuration in the liquid crystal screen around the edge, and then with the light guide plate, so that the LED backlight module light, the light emitted from the edge of the screen through the light guide plate to the central area of the screen to go, so that the overall backlight amount, can make the liquid crystal screen display picture.
Advantages: Less LED crystal can be used to save LED crystal cost; Thin body
Disadvantages: uneven brightness, need to add DBEF; Large size has certain security risks; The stability is poor, the comprehensive cost is high; Assembly trouble.
(2) Straight down backlight
The following formula is to evenly configure the LED grains at the back of the LCD panel as a light source, so that the backlight can be evenly transmitted to the entire screen, and the details of the picture are more delicate and realistic.
1, the picture by light, heat evenly, color picture more delicate;
2, strong stability, no security risks;
3, low comprehensive cost;
4, the assembly is simple and fast;
Disadvantages: The body is thick.
To sum up, the medium and large size interactive tablet using straight down is the best choice! Transparent electromagnetic antenna board is the best choice for straight down interactive plate!
Fourth, the advantages and disadvantages of transparent and non-transparent electromagnetic
1, the new product transparent electromagnetic on the one hand can achieve electromagnetic excellent writing experience, on the other hand, the transmittance of more than 90%, no impact on the brightness, so it can be used in the straight down backlight structure, can also be used in the side of the backlight structure;
2, printed transparent electromagnetic antenna plate than the traditional brush silver paste, stable quality, not easy to break; At the same time, the key parts of the laser welding process, solid and reliable, high stability;
3. The printing transparent electromagnetic antenna plate has lower mold opening cost, better compatibility and lower comprehensive cost.
5. Application fields
Automatic teaching, original pen, trace drawing, natural writing
Paperless recording, original handwriting, interactive discussion, two-pen writing
Fine original handwriting drawing, support, encryption system, interactive discussion
Financial communication Approval - Electromagnetic applications
Authentic original handwriting signature, support, encryption system, industry handwriting authentication