ABOUT OPTICAL BONDING
Originally developed for avionics and military displays, optical
bonding is now moving into industrial and consumer applications
such as touch screens, TVs, smartphones, digital signage and
Optical bonding (LCD bonding, direct bonding) refers to a
protective glass or touchscreen that is glued in front of a display
to enhance its readability in high humidity outdoor environments.
When a normal display is used in an outdoor environment, there are
some factors that affect its readability. The most common one is
“fog”, or condensation, which forms on the inner surface of
display's vandal shield. Another factor is the reflection of
sunlight, which causes a mirror-image on the display. Both
phenomena can be solved by using optical bonding.
Optical bonding is the use of an optical-grade silicon-based
adhesive to glue a glass or touchscreen to the top surface of a
display. The assembly is cured in a process that affixes the
display together while solidifying the adhesive. The main goal of
optical bonding is to improve the display performance under outdoor
environments. This method eliminates the air gap between the cover
glass and the display. Moreover, anti-reflective coating is often
used in optical bonding glass. The real problem for display
readability in outdoor environments is not the display's brightness
but its contrast. Contrast means the ratio of the white level to
the black level; in other words, the contrast ratio of display
means the difference of light intensity between the brightest white
pixel and the darkest black pixel. The main purpose of optical
bonding is to increase the display's contrast ratio by reducing the
amount of reflected ambient light.
· Increased Ruggedness (up to 300%): Bonding a sheet of glass on top of the display increases the
ruggedness of the display.
· Improved Durability: A bonded display is better able to resist scratches, fluids,
stains and dirt.
· Condensation: The elimination of an air gap between the cover glass and the
display means that moisture cannot Penetrate and cause fogging on
· Increased Sunlight Readability (up to 400%): By reducing the amount of reflection, the contrast of the bonded
display is enhanced. The higher the contrast, the easier it is to
read to display screen.
· Extended Temperature Range and EMI Filtering: The temperature range of the display can be extended by
incorporating ITO heaters on the cover glass; EMI filters can be
added via the same mechanism.
Transportation, Navigation, Outdoor Kiosk, Avionics Application,
Rugged Tablet PC, Marine etc.
Configuration and Process: