Views: 204 Author: Andy Publish Time: 2023-05-15 Origin: Site
Capacitive touch screen technology uses the current sensing of the human body to work. A capacitive touch screen is a four-layer composite glass screen. The inner surface and interlayer of the glass screen are coated with one layer of ITO; the outer layer is a thin layer of silicon earth glass protective layer; the interlayer ITO coating is the working face; four electrodes lead from four angles; and the inner ITO is the shielding layer to ensure a good working environment. When the finger is touched on the metal layer, the user and the touch screen surface form a coupled capacitor due to the human electric field. For the high-frequency current, the capacitor is the direct conductor, so the finger suckers a small current from the contact point. This current is separate from the touch. The electrodes in the four corners of the screen flow, 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 of the touch points by accurately calculating the proportion of the four currents.
A capacitive touch screen is a device display screen that relies on finger pressure for interaction. Capacitive touch-screen devices are typically handheld and connect to networks or computers via an architecture that supports various components, including satellite navigation devices, personal digital assistants, and mobile phones.
A capacitive touch screen is activated by human touch, which serves as an electrical conductor used to stimulate the electrostatic field of the touch screen. However, special gloves that produce static electricity or specialized stylus pens may be used.
Capacitive touch screens are built into input devices, including all-in-one computers, smartphones, and tablet PCs.
Techopedia Explains Capacitive Touch Screen
The capacitive touch screen is built with an insulator-like glass coating, which is covered with a see-through conductor such as indium tin oxide (ITO). The ITO is attached to glass plates that compress liquid crystals on the touch screen. User screen activation generates an electronic charge, which triggers liquid crystal rotation.
Capacitive touch screen types are as follows:
Surface Capacitance: Coated on one side with small voltage-conductive layers It has limited resolution and is often used in kiosks.
Projected Capacitive Touch (PCT): Uses etched conductive layers with electrode grid patterns. It has a robust architecture and is commonly used in point-of-sale transactions.
PCT Mutual Capacitance: A capacitor is at each grid intersection via applied voltage. It facilitates multitouch.
PCT Self Capacitance: Columns and rows operate individually via current meters. It has a stronger signal than PCT mutual capacitance and functions optimally with one finger.
Other touch screen technologies include resistive, surface acoustic wave (SAW), and infrared (IR).