Intrinsic safety is a requirement when creating a product that will be used in explosive environments. It is crucial to understand that today you can design LCD panels for use in hazardous environments by incorporating preventative measures into the product.
Objective of Intrinsic Safety
Flash fires and explosions are more common than people realize. In fact, many industries continue to be concerned about the increasing risk of explosions as more and more digital electronics are introduced into the workplace.
There is a collective risk that increases the concentration of dust, flammable gasses, and vapors that build up because of poor ventilation. For instance, for a fire to ignite, it needs fuel, excessive heat, or spark in concentrated settings. When you develop electronic items like LCDs, there is a chance of explosion measures need to be taken to prevent the risk of explosion. The trick is to make sure that the application process doesn’t contain anything that may lead to ignition.
Applicability of Intrinsic Safety
The fact of the matter is that intrinsic safety applies to high concentrations of dust, pure oxygen and other flammable vapors. When it comes to LCDs, the presence of these can lead to severe consequences. The good news is that LCDs can, in many cases, have a safe intrinsic design.
Sparks are Bad
The first goal in the intrinsic safety of LCD designs is to get rid of any spark potential in components and limit total stored energy in circuits. This can be more difficult than it seems. Even the low energy and voltage-powered battery of a smartphone can ignite a gas explosion.
Throughout the design process, LCDs should be designed per the customer’s specification and ensure safety compliance at the same time. The key factor is to determine the exposure to the environment for the LCD panel, create the specifications that will need to be met to meet IS standards within this environment and then begin designing the LCD to meet these specifications. As you may expect, this can create certain limitations.
Some common potential limitations include:
- Avoid capacitive touch screens
- Removal of inverters for backlights
- Removal of a booster circuit or bump circuit
- Ensure short spacing between components on the PCB
The focus of attention is to reduce ignition risk at all costs. For starters, the design of LCDs should reduce the temperature of internal components. Additionally, manufacturers should eliminate or reduce inductors and capacitors to minimize the overall power.
Considerations for LCD Design
There are many design characteristics the LCD manufacturer will have to take into account to ensure the intrinsic safety of the display panels.
First and foremost, LCD manufacturers have to choose the proper components during the design stage to ensure intrinsic safety. It involves extensive consideration of voltage, material, storage energy, size, surface temperature, failure attributes, and operating characteristics. The key is to ensure the suitability of each component of the LCD.
Voltage is a key consideration to ensure the intrinsic safety of LCDs. The goal of manufacturers is to minimize the voltage and reduce the likelihood of spark ignition. This consideration complements component selection that further complements stored energy.
Another design consideration that is critical to ensure intrinsic safety is traces. Exposure of circuit traces creates a high potential for spark ignition, so LCD manufacturers should minimize this risk.
Manufacturers also limit the number of interconnects during the design stage of LCDs. With a high number of interconnects, there is bound to be a complicated display. A low number of interconnects or simplified display design means a low chance for sparking.
Rise of Smartphones
With the popularity of smartphones, there is a high demand for small screen LCD touch panels with multi-touch functions across all industries. The truth is that many LCD panels are not compatible in a concentrated intrinsic environment without some extensive modifications to the design. If you plan to create a handheld, intrinsically safe product with a smartphone-like screen, it is recommended to first identify the IS restrictions that will need to be incorporated into the design and discuss these with an LCD manufacturer such as Focus LCDs.
Mechanics of Intrinsic Safety
Technically, a low-energy standard gets rid of shock hazards and allows you to calibrate and maintain the LCDs. It is important to remember this when exploring new LCD technologies for your product. Remember that intrinsic safety is essentially a compliance level. In some cases, it is difficult to achieve intrinsic safety for different types of displays, however, it may very well be possible.
In retrospect, intrinsic safety is the most common and safest way to protect electronic devices from potential fire hazards or explosions. With intrinsic safety, users don’t have to worry about compromised system integrity that may cause an explosion.
Manufacturers now have to adhere to intrinsic safety requirements while also incorporating modern LCD technology. Whether it’s TFT displays, monochrome LCDs, touch panels or other types of LCDs, intrinsic safety should be the dominant electronic design approach to ensure the protection of users in the field.
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