digital signage for raspberry pi

We will use some electronic devices in our life, LCD module is one of the electronic components. Everyone’s understanding of it must be relatively strange, and then we will talk about the knowledge in this respect.   The following is an introduction to the three basic components and features of LCD. Let’s take a look with the editor: Liquid Crystal Materials Liquid crystal material is the main body of liquid crystal display. Different devices use different liquid crystal materials. Most liquid crystal materials are composed of several or even more than ten kinds of single liquid crystal materials.   Polarizer The light sheet, also known as polarized light, is made of plastic film material, coated with a layer of optical pressure sensitive adhesive, which can be pasted on the surface of the liquid crystal cell. There is a protective film on the surface of the front polarizer, which should be removed when using. The polarizer is afraid of high temperature and high humidity, which will depolarize or blister under high temperature or high humidity conditions.   Glass Substrate A kind of float production thin glass sheet with extremely flat surface, the surface of which is evaporated with a layer of zn203 or sn02 transparent conductive layer, i.e. ITO film, is processed into transparent conductive pattern. If scratched, cut or corroded, the vacuum device will be scrapped.

[Fault Phenomenon] One LCD touch screen doesn’t work, and there is no response when touching any part.   [Fault Analysis and Treatment] First check whether the connection interface is loose, and then check whether there is conflict between serial ports and interrupt number. If there is conflict, adjust resources to avoid conflict. Then check whether there are cracks on the surface of the touch screen. If there are cracks, replace them in time, Also need to check whether there is dirt on the touch screen surface, if there is, use a soft cloth to remove it. Observe and check whether the indicator light on the control box works normally. When it works normally, the indicator light is green and flashes.   If the above parts are normal, the touch screen can be checked by replacement method, first replace the control box, then replace the touch screen, and finally replace the host.   If it is a resistive touch screen, it can be overhauled as follows: 1）Check whether the connection of the touch screen is right, and whether one of the connections (taking 5V touch screen working voltage from the keyboard port) is connected. Please check the connection. 2）Observe the light condition of the touch screen control box. If it doesn’t light up or the red light is on, the control box is broken. Please replace it. 3）If not, please delete the touch screen driver and restart the computer, re-install the driver, or replace the driver with a newer version. 4）If