Capacitive touch screen structure is mainly in the glass screen with a layer of transparent film layer, and then in the conductor layer outside a protective glass, double glass design can completely protect the conductor layer and the sensor.
In addition, in the additional four sides of the touch screen are coated with long and narrow electrodes in the conductor to form a low voltage AC electric field. When the user touches the screen, Capacitive Touch Screen due to the human body electric field, between the fingers and the conductor layer will form a coupling capacitor, the four sides of the electrode current will flow to the contacts, and its strength and the distance between the fingers and electrodes is proportional to the touch screen after the controller Will calculate the proportion of current and strength, accurate calculation of the location of the touch point. Capacitive touch screen double glass can not only protect the conductor and sensor, more effectively prevent the external environment factors to the impact of the touch screen, even if the screen stained with dirt, dust or grease, capacitive touch screen can still accurately calculate the touch position.
Capacitive touch screen transmittance and clarity is better than four-wire resistive screen, of course, can not and surface acoustic wave and five-wire resistors compared. Capacitive screen reflective serious, and the capacitive technology of the four-layer composite touch screen on the wavelength of light transmission is not uniform, Capacitive Touch Screen there is the problem of color distortion, due to the reflection of the light between the layers, but also cause the image character blur. Capacitive screen in principle to the human body as a capacitor element of an electrode used, when there is a conductor near the junction with the ITO working surface coupling a sufficient amount of capacitance, the current flow is enough to cause the capacitor screen malfunction The We know that although the capacitance value is inversely proportional to the distance between the poles, but with the relative area is proportional to, and also with the dielectric insulation coefficient. Therefore, when the larger area of the palm or hand-held conductor close to the capacitive screen rather than touch can cause capacitive screen malfunction, in wet weather, Capacitive Touch Screen this situation is particularly serious, holding the monitor, palm close to the monitor 7 cm Or within the body close to the monitor within 15 cm can cause the capacitor screen malfunction. Another drawback of the capacitive screen is that it does not respond when wearing a gloved hand or a hand-held non-conductive object, Capacitive Touch Screen because it adds a more insulating medium. In addition, theoretically many of the linear relationships should be in fact non-linear, such as: different weight or different levels of finger wetting the total amount of current is different, and the total current changes and four changes in the amount of current Is a non-linear relationship, the capacitive touch screen used by the four corners of the custom polar coordinate system has no coordinates on the origin, drift after the controller can not detect and restore, and, 4 A / D completed by four The value of the shunt value to the touch point in the Cartesian coordinate system on the X, Y coordinate value of the calculation process is complex. Because there is no origin, the capacitive screen drift is cumulative, often need to be calibrated at the job site. Capacitive touch screen the outermost silicant protection glass scratch resistance is very good, but afraid of nails or hard objects percussion, knock out a small hole will hurt the mezzanine ITO, whether it is injured ITO or installation of transport process injury And the inner surface of the ITO layer, capacitive screen can not work properly.
Capacitive touch screen and the traditional resistive touch screen is very different. Resistive touch screen at work can only determine a touch point, if the touch point in more than two, Capacitive Touch Screen can not make the right judgments, so the resistive touch screen is only applicable to click, drag and some simple Action judgment. The capacitive touch screen multi-touch, you can split the user's touch for the acquisition of multi-point signal and determine the meaning of the two signals to complete the complex action to determine.
Use two fingers of the stretch, transposition can be completed on the screen, such as zoom, rotate this fun operation, which in the capacitive touch screen before it is almost unthinkable. Capacitive Touch Screen Apple iPhone after the listing, and soon caused a wave of touch; soon after, Apple and win, launched the same support for multi-touch iPodtouch (in fact, it is equivalent to a simplified version of the iPhone), the same users and media Sought after.