Capacitive touch screen and resistive touch screen are mainly different in touch sensitivity, precision, cost, multi touch feasibility, anti-damage, cleaning and visual effect in sunlight.
Touch Sensitivity
- Resistive touch screen: it needs pressure to make all layers of the screen contact. It can be operated with fingers (even with gloves), nails, stylus, etc. Support for stylus is very important in Asian market, gesture and character recognition are valued everywhere.
- Capacitive touch screen: the slightest touch from the surface of a charged finger can also activate the capacitive sensing system below the screen. Non-living objects, nails and gloves are invalid. Handwriting recognition is difficult.
Accuracy
- Resistive touch screen: the accuracy is at least a single display pixel, which can be seen when using the stylus. It is easy to recognize handwriting and is helpful to operate in the interface using small control elements.
- Capacitive touch screen: the theoretical accuracy can reach several pixels, but it is actually limited by the finger contact area. So that it is difficult for users to accurately click the target less than 1cm2.
Cost
- Resistive touch screen: very cheap.
- Capacitive touch screen: the price of capacitive screen from different manufacturers is 10% to 50% higher than that of resistive screen. This extra cost doesn’t matter for flagship products, but it may deter mid-priced phones.
The feasibility of multi touch
- Resistive touch screen: not possible unless the resistive screen is reconstituted and connected to the circuit of the machine.
- Capacitive touch screen: depending on the implementation method and software, it has been implemented in G1 technology demonstration and iPhone. The 1.7t version of G1 can realize the multi touch feature of browser.
Damage resistance
- Resistive touch screen: the basic characteristics of resistive screen determine that its top is soft and needs to be able to be pressed down. This makes the screen very scratch prone. Resistive screens require a protective film and relatively more frequent calibration. The advantage is that the resistive touch screen device with plastic layer is less vulnerable and less likely to be broken.
- Capacitive touch screen: the outer layer can use glass. In this way, although the glass is not indestructible and may break under severe impact, it is better to deal with daily rubbing and stains.
Clean
- Resistive touch screen: it is not easy to leave fingerprints, oil stains and bacteria on the screen because it can be operated with a stylus or nail.
- Capacitive touch screen: touch with the whole finger, but the outer layer of glass is easier to clean.
Environmental adaptability
- Resistive touch screen: the specific value is unknown. However, there is evidence that the Nokia 5800 with a resistive screen can work well at temperatures ranging from – 15 ° C to + 45 ° C, and has no requirement for humidity.
- Capacitive touch screen: the typical operating temperature is between 0 ° and 35 ° and requires at least 5% humidity (limited by working principle).
Visual effects in the sun
- Resistive touch screens: usually bad, extra screen layers reflect a lot of sunlight.
- The capacitive touch screen uses the current induction of human body to work. Capacitive touch screen is a four layer composite glass screen, the inner surface and interlayer of the glass screen are coated with a layer of ITO (coated conductive glass), the outermost layer is a thin layer of silica glass protective layer, the ITO coating is used as the working surface, four electrodes are led out from the four corners, and the inner layer of ITO is used as the shielding layer to ensure a good working environment.
When the finger touches on the metal layer, the human electric field, the user and the touch screen surface form a coupling capacitance. For high-frequency current, the capacitance is a direct conductor, so the finger absorbs a small current from the contact point. The current flows out from the electrodes on the four corners of the touch screen, and the current flowing through the four electrodes is proportional to the distance from the finger to the four corners. The controller obtains the position information of the touch point through the accurate calculation of the four current proportions.
Now, the use of capacitive screen is a little more, because it has the advantages of precise point position, easier to support multi touch and so on. But at the same time, it is also more delicate, so we need to take good care of it and take good care of it.
