Capacitive touch screen indicators and main performance

Pubdate : 2021-04-29        View:5

 Capacitive touch screen indicators and main performance

For capacitive touch screen system, the performance index can be divided into operating temperature range, power consumption, signal to noise ratio, scanning speed, waterproof, anti-aging, ESD, anti-interference ability, RF and so on.

Signal to noise ratio is the core index. Most of the performance on the use experience depends on the signal to noise ratio. For example, the standard degree of touch, the size of the touch coordinate, the size of the dither, and the linearity of the line, all depend entirely on the signal to noise ratio. According to the relationship between touch screen and display screen, the touch coordinate accuracy should be accurate to each pixel of the display screen. It can be calculated that the signal-to-noise ratio of capacitive touch screen system is 50 (34dB). Depending on the system in different environments, the signal-to-noise ratio may decrease

There is no quantitative index for the ability to resist RF interference. Only qualitatively, in normal use environments, GSM signals, CDMA signals, WIFI signals, microwave signals, and such civilian wireless communications devices are not allowed to interfere with the normal operation of the touch screen.

The scan speed is defined as the speed at which the touch-screen controller scans the touch screen. According to the characteristics of touch buttons, a button will exceed 20mS. As long as the scan within 20mS, must be able to scan the touch occurred.

Your fingers sweat when you touch them. Devices with capacitive touch screens enter a hotter place from a cooler location, and a layer of fog appears on the surface of the capacitive touch screen. Capacitive touch screens are required to be used in all two cases.

Using capacitive touch screen device, the working environment varies greatly, the temperature range must be wide, otherwise it may cause constant change to the user. General capacitive touch screen, the operating temperature range of -20 degrees - 70 degrees.

Capacitive touch screens are aging during use. The touchscreen performance will decrease after aging. Capacitive touch screen system must be able to correct the general aging, so that it can be used properly, and extend the system life.Portable devices, power consumption is often very critical. Capacitive touch screen systems require that they do not significantly affect battery life.

The design of portable equipment is becoming thinner and more integrated. The requirements for components are usually as small as possible. The requirements for the packaging industry of the capacitive touch screen controller IC are put forward.