Industrial LCD features, usage and storage considerations
Date:2019-07-11
We all know that liquid crystal screen is made of liquid crystal material as the basic component, glass and other crystal materials, which is fragile. Any drop, knock and strong vibration may cause the glass of industrial LCD to break; The stability and raw materials of industrial LCD screen are much better. Similarly, the market price of industrial LCD screen will be more expensive. We usually use industrial LCD screen and pay attention to it according to its characteristics, which will definitely delay the service life of industrial LCD screen. For specific industrial LCD screens, we will list them one by one
Protective film for industrial LCD
A layer of protective film is pasted on the finished product surface of the installed industrial LCD module to prevent the display surface from being contaminated during the assembly of the industrial LCD. The protective film of the industrial LCD shall not be removed before the assembly of the whole machine, so as to avoid soiling or damaging the display surface.
2. Industrial LCD screen with gasket
It is better to install a pad of about 0.1mm between the industrial LCD module and the front panel. The panel of industrial LCD should also be absolutely flat to ensure that there is no twisting force after assembly and improve the anti vibration performance.
1、 Prevent static electricity for industrial LCD screen
The control and drive circuit of industrial LCD module is a low-voltage, low-power CMOS circuit, which is easy to be electrostatic breakdown. Electrostatic breakdown is an irreparable damage, and the human body sometimes produces high-voltage static electricity as high as tens of volts or hundreds of volts. Therefore, in the operation, assembly and use, we should be extremely careful to prevent static electricity.
1. Don't touch the external lead, the circuit on the circuit board and the metal frame by hand;
2. If direct contact is necessary, keep the human body and the module at the same potential, or ground the human body well;
3. Soldering iron used for welding and electric tools used for operation must be well grounded without static electricity;
4. Do not use vacuum cleaner for cleaning, because it will produce strong static electricity;
5. Air drying also produces static electricity, so the humidity of the workshop should be above 60%;
6. Care should also be taken when taking out or putting back the package or moving position to prevent static electricity. Do not change the package or abandon the original package at will.
7. Electrostatic breakdown is a kind of irreparable damage. Pay attention not to be careless
4、 Matters needing attention in assembling operation of industrial LCD screen
1. After careful design and assembly, please do not process or repair it by yourself;
2. The metal frame claw shall not be twisted or disassembled at will;
3. Don't modify PCB shape, assembly hole, circuit and parts at will;
4. The conductive adhesive strip shall not be modified; Do not modify any internal supports;
5. Do not touch, fall, twist or twist the module.
5、 When welding the external lead and interface circuit of industrial LCD module, the following procedures shall be followed.
1. The temperature is less than 280 ℃; The welding time is less than 3 ~ 4S;
2. Welding material: eutectic, low melting point; Do not use acid flux;
3. Repeat welding not more than 3 times, and each time interval of 5 minutes.
6、 Use and maintenance of industrial LCD module
1. The external lead of industrial LCD module is not allowed to be wrongly connected. When you want to debug the LCD module, please pay attention to the correct wiring, especially the wiring of positive and negative power supply. Otherwise, it may cause over-current, over-voltage, burning chips on the circuit and other damage to the LCD module components;
2. When the industrial LCD module is in use, the input signal level can only be input after the positive power is stably connected. If the input signal level is input before or after the power supply is stable, the IC and circuit in the module may be damaged;
3. When using, the sequence of connecting logic power supply and driving power supply should be logic power supply first and driving power supply second; In case of power failure, drive power supply first, then logic power supply. This will help to maintain the good display effect of the screen and avoid the voltage impact damage when power on or power off. Therefore, DC-DC power supply with control is recommended as the driving power supply of the module.
4. Therefore, if Vee is adjusted too high, it will not only affect the display, but also shorten the service life of the module;
5. Because of the physical properties of liquid crystal materials, the contrast of liquid crystal will change with the change of temperature. Therefore, the negative voltage value you add should be adjusted with the temperature, which is about 10 ℃ and 1 v. To meet this requirement, you can use a temperature compensation circuit or a potentiometer to adjust the negative voltage value with the temperature; 6. It should not be used outside the specified working temperature range, and should not be stored beyond the storage limit temperature range. If the temperature is lower than the crystallization temperature, the liquid crystal will crystallize. If the temperature is too high, the liquid crystal will become isotropic liquid, destroy the molecular orientation, and make the device scrapped;
7. Pressing the display part hard will produce abnormal display. At this time, cut off the power supply, wait for a moment, power on again, that is, return to normal;
8. When there is fog on the surface of LCD or module, do not work with power on, because it will cause chemical reaction of electrode and lead to disconnection;
9. When used in sunlight and strong light for a long time, the covered part will produce residual image.
7、 Storage of modules
For long-term storage, we recommend the following methods:
1. Put it into a polyethylene bag (preferably with antistatic coating) and seal the mouth;
2. It is stored between - 10 ℃ and + 35 ℃; In the dark, avoid strong light;
3. Never press anything on the surface; Strictly avoid storage under extreme temperature / humidity conditions;
According to the above introduction of industrial LCD use and storage precautions to do a good job, the service life of industrial LCD will certainly increase a lot.
