First, the basic structure of curved screen
A curved screen usually consists of three parts: a curved LCD module, a touch module, and a curved glass.
1. Curved screen LCD module
LCD module is the main part of curved panel, which is composed of controller, driver, backlight and LCD panel. Together, these components manage the pixels on the screen, resulting in high definition and display.
2. Touch module
Touch module is added to the LCD module accessories, including induction capacitance sensor, FPC (flexible circuit board) and drive circuit, etc. Through these parts, the contacts can properly track finger movements and send a touch signal to the phone's processor. In curved screen, special attention is paid to the adaptation and application of induction capacitance sensor.
3. Curved glass
Curved glass is a transparent material used to cover LCD modules and touch modules. Through the use of tempered glass, curved glass and a wide range of radian design, make the whole phone body appearance highly exquisite.
Second, the principle of capacitive touch
Most touch screens on the market today use capacitive touch technology. This technique is divided into resistive touch and capacitive touch. Here, we will focus on capacitive touch.
Capacitive touch technology is a way to achieve touch control through changes in the electric field on the screen. When we approach the touch screen with our fingers or a capacitive object, it changes the charge distribution and potential difference, causing a change in the electric field. An inductive capacitance sensor at the bottom of the screen senses this change and converts it into a digital signal. The processor then analyzes and calculates the charge change according to the coordinates of the contacts and displays the corresponding content. Therefore, in the design of curved screen, it is necessary to design a suitable sensor array of induction capacitance, in order to accurately sense the change of finger electric field.
3. Realization of capacitive touch on curved screen
From the above explanation, we can know that the capacitive touch technology of curved screen needs to complete two key steps: the adaptation of inductive capacitance sensor and the design of curved glass.
1. Adaptation of induction capacitance sensor
The adaptation of inductive capacitance sensor is the first step of capacitive touch on curved screen. In contrast to conventional capacitive touch technology, inductive capacitance sensors on curved screens should be designed according to curvature. Most manufacturers use two different capacitive sensors on the necessary curved parts for better sensing. These two sensors are mounted on the edge part of the screen, usually on the left and right sides, one above the screen panel and one below the screen. The two sensors combine to accurately sense the touch signal of the curved screen.
2. Design of curved glass
The design of the curved glass is the second step in the capacitive touch of the curved screen, which aims to ensure that the surface of the screen is flat and provide accurate information to the sensor. The design of curved screen consists of many complicated processes, including the calculation of glass texture and curvature, and the production of tempered glass.
When choosing glass material, it is necessary to consider its thickness, hardness and bending. The glass should be thin enough to ensure that the screen is light and that the bending radius of the screen is smaller than the size of the screen, thus reducing the effects of glass stress. In addition, the treatment of tempered glass does not have the traditional glass strengthening treatment scheme, and a specialized bending glass process must be used to treat glass fragments.
Capacitive touch technology for curved screens is now quite mature. The capacitive touch of the curved screen makes it easier to feel the touch of a finger while keeping it beautiful.
