The Advantages And Disadvantages Of Capacitive Touch Panel
Capacitive Touch Panel transmittance and clarity is better than four-wire resistive screen, of course, can not and surface acoustic wave and five-wire resistance screen compared. Capacitive screen reflective serious, and, capacitive technology of the four-layer composite touch screen on the wavelength of light transmission is not uniform, there is the problem of color distortion, due to the reflection of the light between the layers, but also cause the image character blur.
Current: the 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 capacitive screen Wrong move.
Although the capacitance value is inversely proportional to the distance between the poles, it is proportional to the relative area and is also related to the insulation coefficient of the medium. 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, 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 capacitive screen malfunction. Another drawback of the capacitive screen is that it does not respond when wearing gloved hands or hand-held non-conductive objects, due to the addition of more insulating media.
Drift: Capacitive screen is the main drawback is drift: When the ambient temperature, humidity changes, the environment electric field changes, will cause the capacitive screen drift, resulting in inaccurate. For example, the display temperature rise will cause drift after the boot: the user touches the screen while the other hand or body side is close to the monitor drift; the Capacitive Touch Panel near the larger objects move will drift, the user touches if someone around to watch (Including the user's body), although the Capacitive Touch Panel away from the far, but much larger than the finger area, they directly affect the touch location of the location of the screen Determination.
Other: In addition, theoretically many should be linear relationship is actually 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 sub-current The change of the non-linear relationship, the Capacitive Touch Panel used in this four-angle custom polar coordinate system has no coordinates on the origin, after drift the controller can not detect and restore, and, after 4 A / D is completed by the four The value of the split flow to the touch point in the Cartesian coordinate system on the X, Y coordinate value of the calculation process is complex. Since there is no origin, the drift of the capacitive screen is cumulative, and calibration is often required at the job site. Capacitive Touch Panel The outermost siliceous glass protects the glass from scratches well, but fear of nails or hard objects percussion, knocking out a small hole will hurt the mezzanine ITO, whether it is hurt the mezzanine ITO or install the transport process injury The inner surface of the ITO layer, capacitive screen can not work properly.