Selection of the TFT LCD Touch Screen

In the information age of rapid development, LCD screens have been widely used in various fields, with TFT LCD touch screens with touch functionality being particularly prominent.

Touch screens are used in commercial, household, medical, and industrial fields. When we enter a shopping mall, there is usually a large touch screen at the stairway where we can click to access the brand guide distribution on each floor.

When we use smart home appliances at home, we can control them by clicking on the intelligent panel. We can also use handheld devices with touch functionality for outdoor measurement work by directly clicking on the content. The touch screen breaks away from the traditional control mode of buttons and can be clicked and slid directly on the screen, making human-machine interaction more direct and convenient.

There are many types and specifications of TFT LCD touch screens. How can we choose the touch screen that suits our project when developing a project? Below, we will introduce the selection of TFT LCD touch screens from different dimensions.

Touch types of touch screens

From the perspective of touch types, TFT LCD touch screens are divided into resistive touch screens and capacitive touch screens. The principle of the resistive touch screen is to control it by pressure induction, making the various layers of the screen in contact, and touch can be made with fingers or touchpens. The capacitive touch screen works by using the body's current induction and only supports finger operation.

Both types of touch have their advantages. The resistive touch screen has high surface hardness, good durability, simple manufacturing process, low cost, and is suitable for small-scale products with low touch requirements. The capacitive touch screen has high touch accuracy, fast response, supports multi-touch, but the manufacturing cost is relatively high, and it is more suitable for harsh industrial and outdoor environments, as well as electronic products with higher touch precision requirements.

Touch accuracy of touch screens

TFT LCD touch screens may be affected by surrounding electromagnetic interference, so they need to provide reliable touch accuracy functions for the display device. Users can click on the corresponding interface according to their intentions without mis-clicking or misoperation.

In comparison, capacitive touch screens are products with relatively high touch accuracy. When users touch the capacitive screen, a coupled capacitance is formed between the user's finger and the working surface because of the body's electric field. Since the working surface is connected to a high-frequency signal and the finger absorbs a small current, this small current flows out of the electrodes at the four corners of the screen respectively. The controller calculates the position based on the precise calculation of the proportion of the four current ratios. Therefore, capacitive touch screens can achieve up to 99% accuracy.

Touch resolution of touch screens

The resolution of TFT LCD touch screens refers to the number of touch points and parallel touch points of TFT touch screens. The high or low touch resolution of touch screens will affect accuracy and click-through rate. High-resolution touch screens can provide more touch points and better pointing accuracy, thereby achieving more precise clicks and better user experience. Generally, high-resolution touch screens have resolutions such as 800*480, 1024*600, and 1280*800.

Response time of touch screens

The touch response time of TFT LCD touch screens refers to the time from when the user touches the screen panel to when the screen responds to the operation. The shorter the touch response time, the better the user experience. Experiments have shown that a response time of less than 10 milliseconds will make people feel comfortable. The response time of capacitive touch screens is very good, about 3 milliseconds, while that of resistive touch screens is relatively worse, about 10 milliseconds.

Working environment of touch screens

The working environment of TFT LCD touch screens is divided into indoor and outdoor. The indoor environment is relatively superior, so the specification requirements for touch screens are not so high.

For touch screens working in relatively harsh outdoor environments, many environmental factors affecting the screen must be considered, such as dustproof, high temperature, and high humidity.

Usually, touch screens are customized based on the environment. For example, if the touch screen works in a high-temperature and sunny environment, it needs to have outdoor high-brightness and ultra-wide working temperature functions. In a dusty working environment, dustproof function needs to be added, and the glass panel needs to be improved.

Through the above introduction, everyone should have a preliminary understanding of the selection of TFT LCD touch screens. Customizing the LCD touch screen that suits your product from cost and actual needs is the most correct display solution.