How is the industrial touch screen used in wide temperature? What is the working principle of wide temperature?
Method 1: Use low temperature heating
There are two ways of low temperature heating: point-by-point heating and whole-surface heating. Such a display will increase the overall power consumption by 4-6 times. For example, the power consumption of a 15-inch liquid crystal display at room temperature (22°C) is 20ww, and the power consumption in a low temperature environment (-40°C) is: 90-120w. This heating method makes the machine use it for a long time. In the process, the phenomenon of liquid crystal flow out or restoration difficulty sometimes occurs.
Method 2: Increase the brightness of the LCD screen
Through the developed special high-voltage strip (which can generate a starting voltage of 2000v-3000v), the backlight tube is turned on in a low temperature environment (-40°C), and the liquid crystal is heated up due to the huge heat generated by the backlight tube. It not only solves the problem of low temperature operation of liquid crystal, but also solves the problem of visibility under sunlight. This method is referred to as the brightening method.
Disadvantages of method 1 and method 2: ① These two methods both add many accessories and reduce reliability. ②It is more troublesome to assemble and produce, and it is easy to cause defective products, and the defective product rate is high. ③ The ability of the device to resist shock and vibration is reduced. ④In the aging test, it was found that in the environment of 50°C, the aging speed is extremely fast, and the acceleration increases, especially the brightening method, the life is only 1/10 of the normal.
Mode 3: The new liquid crystal high and low temperature application technology, the product can work normally at low temperature without heating or brightening
The basic principle is as follows: the liquid crystal does not freeze or change its physical state at low temperature (-40°C), otherwise neither the heating method nor the brightening method can work, so we thought of using software to correct the drift of its electrical characteristics . Managed to trigger the work of the liquid crystal at low temperature. This requires adjusting the driving timing of the liquid crystal and so on. Through a large number of experimental studies and extensive applications, this technology has become very mature. No matter how the ambient temperature changes, the normal operation of the liquid crystal can be guaranteed by widening the trigger timing and matching the corresponding drive.
