Feb 16 2010
Liquid Crystal Display (LCD) technology and display quality continues to evolve, while prices for LCDs have declined dramatically in the last few years. These two factors have helped to increase demand for LCDs in a variety of new and challenging applications, such as outdoor displays, where environmental conditions such as high ambient light and heat build-up can affect display quality. This has created a need for unique solutions to help extend the lifetime and display quality of LCDs in these conditions. One such solution is the use of UV blocking glass.
LCDs utilize organic components that are susceptible to ultraviolet degradation, which can manifest as a shift in color or a washed out look. Displays used in outdoor environments or in close proximity to Fluorescent black lights and other long wave UV emitters are at considerable risk of Ultraviolet degradation. Outdoor LCD devices are at high risk, but with more indoor UV emitter applications being developed it has become apparent that sunlight based ultraviolet radiation is not the only concern. Indoor UV emitter applications are being developed or are currently in use by medical and forensics groups for example.
The atmosphere itself blocks a significant portion of sunlight Ultraviolet radiation up to 280 nm, which is the top end of the UV C range. Oxygen is the primary element responsible for the atmospheres filtering effect on UV C. Indoor UV C emitters are in relative close proximity to the LCDs they would potentially affect and thus are not likely to benefit as much from the filtering effects of the atmosphere. UV C is also damaging to people and so high intensity emitters use protective barriers to contain the UV C radiation. For this reason, LCDs within the application would need a protective UV Blocking Glass.
UV B is less blocked by the atmosphere, but is still significantly blocked by ordinary glass (although this is not generally true for Silica or quartz glass). In situations where an application uses UV B radiation, it is recommended that the application be sealed to prevent excessive human exposure. Any application that needs an LCD to be exposed to UV B radiation regularly should utilize a UV Blocking Glass coating to ensure that the LCD does not degrade.
While ordinary glass blocks a significant portion of UV B this still leaves a significant portion of the UV A range that permeates the front of an LCD. It is this UV A range that has often eluded efforts to prevent ultraviolet degradation. Its effects are often not as obvious, but can be seen in many everyday situations where carpet, drapes or other natural and synthetic polymer objects are left in a window for long periods of time. They fade, crack or disintegrate due to the unblocked UV A radiation that passes through ordinary glass.
ZC&R’s UV Blocking Glass solutions act as a mirror to ultraviolet radiation. In combination with a hot mirror (IR Reflector), this coating helps preserve the performance of an LCD exposed to unfiltered broadband lighting while retaining the visibility and clarity of the display.