What is a capacitive touch screen? Analysis of its working principle and advantages

In modern smart devices, capacitive touch screens have become one of the mainstream technologies. From smartphones to industrial control panels, its sensitivity and durability are highly favored by the market and users. So, what exactly is a capacitive touch screen? How does it work? Shenzhen Xinlilai Optoelectronics Technology Co., Ltd. will provide you with a detailed analysis in this article.
 

1. Basic principle of capacitive touch screens
Capacitive touch screen, also known as capacitive touch sensor, is a display control interface that utilizes the conductivity of human fingers or specific input devices for input and control. It is usually composed of four layers of composite glass, including various coatings and electrodes.
 

The core of capacitive touch screens lies in capacitive sensing technology. Its surface is coated with a transparent conductive material (such as ITO, also known as indium tin oxide), which changes the electric field distribution on the screen surface when a finger (or other conductive object) approaches it, allowing the sensor to detect the touch position.
 

Its main features and working principle are as follows:
The outermost layer of the touch screen is a transparent conductive film layer, which is covered with a protective glass layer.
 

The inner surface and intermediate layer of the glass are coated with indium tin oxide (ITO), a transparent conductive material. The outermost layer is a thin protective layer of silicon glass. When touched, the human electric field forms a coupling capacitance with the surface of the touch screen, causing a small current to flow towards the contact point, which is then measured to determine the touch position. The electrodes in each corner of the touch screen calculate the charge and transmit the information to the controller for processing, thereby accurately determining the touch position.
 

Unlike resistive touch screens (which require pressure), capacitive screens only require a light touch to respond, making operation smoother and supporting multi touch.
 

2. The main types of capacitive touch screens
There are currently two main types of capacitive touch screens on the market:
Surface Capacitive: Only electrodes are arranged at the four corners of the screen, suitable for large-sized screens, but only supports single touch.
Projected Capacitive (PCAP): Using a fine electrode grid, it can accurately recognize multi touch and is widely used in devices such as smartphones and tablets.
 

3. Advantages of capacitive touch screens
High sensitivity: No need to press hard, respond with a light touch.
Support multi touch: capable of performing gesture operations such as zooming and rotating.
Strong durability: The surface is usually made of tempered glass, which is scratch resistant and wear-resistant.
High transmittance: clearer display effect, suitable for high-definition screens.
 

4. Applicable scenarios
capacitive touch screens are widely used in:
Smartphones&Tablets
Car display screen
Industrial control panel
Self service terminals (such as ATMs, vending machines)
Smart home control screen
 

As a professional touch screen manufacturer, Shenzhen Xinlilai Touch Technology Co.,Ltd provides a variety of specifications of capacitive touch screens to support customized needs. If you have any related needs, please feel free to consult at any time!