advantage

Capacitive touch screens only need touch, not pressure to generate signals.

Capacitive touch screens require only one or no calibration after production, while resistive technology requires conventional calibration.

The life of the capacitive solution will be longer, because the components in the capacitive touch screen do not require any movement. In resistive touch screens, the upper ITO film needs to be thin enough to be flexible so that it can bend downward to contact the lower ITO film.

Capacitive technology is superior to resistive technology in terms of light loss and system power consumption.

The choice between capacitive technology or resistive technology mainly depends on the object that touches the screen. If it is touched by a finger, a capacitive touch screen is a better choice. If you need a stylus, whether it is plastic or metal, a resistive touch screen can do the job. The capacitive touch screen can also use a stylus, but it needs a special stylus to cooperate.

The surface capacitive type can be used for large-size touch screens, and the relative content is relatively low, but it cannot support gesture recognition nowadays: the inductive capacitive type is mainly used for small and medium-sized touch screens, and can support gesture recognition.

Capacitive technology is wear-resistant, has a long life, and has low maintenance costs when used by users. Therefore, the overall operating costs of manufacturers can be further reduced.

Capacitive touch screens can support multi-touch technology, and unlike resistive touch screens, the response is slow and not easy to wear.

shortcoming

The light transmittance and clarity of the capacitive touch screen are better than the four-wire resistive screen, and of course it cannot be compared with the surface acoustic wave screen and the five-wire resistive screen. Capacitive screens reflect serious light, and the four-layer composite touch screen of capacitive technology has uneven light transmittance to light of various wavelengths, and there is a problem of color distortion. Due to the reflection of light between layers, image characters are also blurred.

Current: In principle, the capacitive screen uses the human body as an electrode of a capacitor element. When a conductor is close to the working surface of the interlayer ITO and a capacitor of sufficient capacitance is coupled, the current flowing away is enough to cause the capacitive screen Misoperation.

Although the capacitance value is inversely proportional to the distance between the poles, it is directly proportional to the relative area and is also related to the insulation coefficient of the medium. Therefore, when a large area of the palm or a hand-held conductive object is close to the capacitive screen instead of touching, it can cause the capacitive screen to malfunction. In wet weather, this situation is especially serious. Hold the display with the palm close to the display 7 cm Within 15 cm of the body close to the display can cause the capacitive screen to malfunction. Another disadvantage of capacitive screens is that there is no response when touched with gloved hands or holding non-conductive objects. This is because a more insulating medium is added.

Drift: The main disadvantage of the capacitive screen is drift: when the ambient temperature and humidity change, and the environmental electric field changes, it will cause the capacitive screen to drift and cause inaccuracy. For example: The temperature of the display will rise after power-on, which will cause drift: when the user touches the screen, the other hand or one side of the body will drift close to the display; larger objects near the capacitive touch screen will drift after being moved. It can also cause drift; the reason for the drift of the capacitive screen is due to technical inadequacy. Although the environmental potential surface (including the user's body) is far away from the capacitive touch screen, it is much larger than the area of the finger. They directly affect the touch position. Determination.

Others: In addition, many relationships that should be linear in theory are actually nonlinear, such as: the total amount of current drawn by people with different weights or different degrees of finger wetness is different, and the change in total current and the four sub-currents The change is a non-linear relationship. The four-corner custom polar coordinate system adopted by the capacitive touch screen has no coordinate origin. After drifting, the controller cannot detect and recover. Moreover, after the 4 A/D is completed, the four The calculation process from the value of the sub-flow rate to the X and Y coordinate values of the touch point on the Cartesian coordinate system is complicated. Since there is no origin, the drift of the capacitive screen is accumulated, and calibration is often required at the work site. The outermost silica protective glass of the capacitive touch screen is very scratch-resistant, but it is afraid of nails or hard objects. If a small hole is knocked out, it will damage the interlayer ITO, whether it is damage to the interlayer ITO or during installation and transportation. With the ITO layer on the inner surface, the capacitive screen cannot work normally.