Touch Panel (TP), also known as "touch screen" or "touch panel", relies on touch sensor technology to input information. Depending on the principle of operation, touch panels can be classified into resistive, capacitive, optical, ultrasonic and electromagnetic induction.
Capacitive touch screen has become the current mainstream technology product because of its high sensitivity, good light transmission, strong stability and long service life. It supports multi-touch and is widely used in intelligent consumer electronics, industrial control medical equipment, smart home, office equipment and automotive electronics. Capacitive touch screen can be divided into two types, external and embedded, according to different technical routes.
The basic structure of external capacitive screen is that the touch panel and LCD panel are separated. It mainly consists of two types of film-type and glass-type programmes, including GFF (cover + ITO film + ITO film), GF (cover + ITO film), GG (cover + ITO glass) and OGS (integrated touch), respectively. Among them, the GF solution saves a layer of film compared to the GFF solution, while OGS is an upgraded solution of GG. The advantages of the external structure scheme are simple process, mature technology and low cost.
Different from the external type, the embedded capacitive screen integrates the touch panel and LCD panel, mainly including In-Cell and OnCell solutions. In-Cell capacitive screen has thin and light, high light transmission and other characteristics, but due to the high technical threshold, the need to integrate thin film transistor array circuit, and involves the development of photomask and process technology, which will increase production costs. Therefore, the main application areas of embedded capacitive screens are currently mostly focused on the smartphone market.
With the continuous progress of technology and the growth of market demand, touch screen technology will continue to be optimised to bring more convenience to people's daily life and work. At the same time, different types and structures of touch screens will also play their unique advantages according to the different needs of application areas.