Performance enhancing glass bonding technology

Paul Boughton
Hitachi Display Products Group (DPG) has announced the introduction of value added LCD display solutions featuring performance enhancing glass bonding technology.

Optical glass bonding technology can provide notable improvements in optical performance in high brightness environments. By using an optical adhesive and a cost effective lamination process a glass substrate is bonded directly to the front of the TFT LCD module.

The bonding process ensures that there is no air gap between the glass substrate and the display. Removing the air gap ensures parallax effects and internal reflections are prevented and this will result in enhanced optical performance in bright ambient light conditions. Mechanical durability is also improved by enhancing the ruggedness of the display.
TFT LCD display modules have become widely and extensively used in many electronics products and systems that require a high quality graphical user interface. Certain environmental conditions such as bright ambient light and outdoor conditions can present challenges for conventional TFT displays. When a display is used in a high ambient light environment, if the amount of ambient light reflected by the display is close to or exceeds the amount of light emitted by the display, the display image can become unreadable and ‘washed out’.

In this situation contrast loss can be close to 100 per cent as the luminance of the display is exceeded. A TFT display featuring an optically bonded glass substrate and surface treatment techniques can reduce reflections to less than 0.2 per cent by scattering and absorbing ambient light. These additional features will ensure that display readability can be notably improved.
Mark Stephenson, Product Marketing Manager, commented, “Many TFT displays are used in bright ambient light or outdoor conditions which present difficulties when trying to ensure that the display provides optimum readability. The use of glass optical bonding technology coupled with an enhanced anti-reflection or anti-glare surface finishes can significantly improve the optical performance of the display. Further benefits include making the display module more rugged and able to provide enhanced shock and vibration performance. Display durability is also improved with increased impact and scratch resistance and reduced fluid and foreign particle ingress.”
Developments in optical glass bonding techniques has now enabled Hitachi TFT LCD display modules to offer excellent readability in demanding ambient light conditions. This enhances the provision of TFT display solutions across a wider range of environments and applications. Optical bonding technology has been successfully implemented on TFT displays used in challenging environments such as aerospace, marine, automotive, medical and industrial. It is also being viewed as a key display enhancement technology for facilitating the development of emerging products and designs.
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