Optical bonding is the process of laminating touchscreens, glass or plastic cover lenses, EMI filters, and other display enhancements to an LCD. A layer of adhesive is integrated between the cover layer and display to fill the air gap left behind in a typical perimeter or gasket bond. Once the adhesive is cured, the final product has better optical and ruggedization properties. Types of optical bonding vary, from UV curable liquid optically clear adhesives or resins (LOCA/OCR) to dry film adhesive (DFA/OCA). At Touch International, we choose the most effective bonding method and type of adhesive for the substrates and LCD to meet the application requirements and effectively improve the performance of the final product.
Touch International offers optical bonding solutions to optimize display functionality and performance. Bonding improves sunlight readability by up to 400%, durability by up to 800%, and boosts resistance to physical impact, vibrations, moisture, heat, and humidity. Environmental testing is done at our facilities and qualified per MIL-STD-810F.
Military applications can be designed and manufactured in our ITAR Registered Headquarters in Austin, TX.
Better Optical Performance
Reduced Reflections – Surface reflections can be a minor nuisance to a safety hazard depending on the application. When operating any vehicle, watercraft, or aircraft instrument panels and navigation displays must be glare free and easy to read. Environments with high ambient lighting can cause internal and external reflections that impair the visual quality of the screen. External light reflections decrease with anti-glare and anti-reflective top surface enhancements without additional power consumption. Air gaps cause internal reflections between the display and touch panel. Optical bonding fills the gap and eliminates the inner light reflection.
Dust, Moisture, and Condensation – Air gaps are also susceptible to contaminants such as dirt, dust, moisture, and condensation. Chances of environmental contamination increase in rugged-use instrumentation such as agricultural equipment or military devices. Presence of contaminants increases the risk of failure in the adhesive tape or other material used in the perimeter bond. Optical bonding eliminates the potential of contamination and condensation, protecting and extending product life.
Parallax – Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight. It is measured by the angle or semi-angle of inclination between those two lines. Displays with an air gap have a noticeable amount of parallax that increases with variations of mounting tape thickness or cover lens specifications. In an optical bond, light passes through a single index of refraction, eliminating parallax. Total stack height is reduced compared to using foam mounting tapes, an additional benefit to a touch display product.
Impact Resistance – An optically bonded cover lens increases impact resistance on most LCD modules and helps protect it from physical damage. The touchscreen or any component on the front of the display can flex under pressure with a gasket or perimeter bond. Optical bonding reinforces these components and decreases the chances of field failures from use and abuse.
Adding custom cover glass, touchscreens, optical filters, optical coatings, and other enhancements with optical bonding creates a durable and complete rugged solution.
Deflection Protection – The added strength of an optical bond decreases deflection of the LCD. For example, when a person is using a stylus on a digitizer unit, they may notice the effects of the point hampering display performance. Using an optical bond and a thin cover glass drastically reduces the risk of a poor performing LCD.
Vibration Resistance – Vibrations encountered in aerospace, military, transportation, and other industrial environments and applications weaken the integrity of a touch display product. Vibrations can rattle the LCD and its internal components causing premature failure.
Optical bonding locks the cover glass any other optical filters in place along with the LCD bezel and lens.
Integrated Touch Display Solutions with Optical Bonding
Optically bonding touchscreens and other enhancements is a key component of our total touch display solutions and can be combined with any of our touchscreen technologies, optical filters, transparent heaters, specialty coatings, and the display of your choice. For more information on our turnkey integration options, please visit our Touch Display Solutions Design & Manufacturing page.