What Are the Benefits of Optical Bonding for Aviation Displays?

Aviation displays operate in some of the most demanding environments for electronic equipment. Bright sunlight, changing viewing angles, vibration, temperature fluctuations, and continuous operation can all affect display performance and readability.

For aircraft manufacturers, avionics suppliers, and aerospace system integrators, improving display visibility and reliability is therefore an important part of display design.

One technology commonly used to improve display performance is optical bonding.

But what is optical bonding, and what benefits does it provide for aviation displays?

What Is Optical Bonding?

Optical bonding is a display enhancement process in which the air gap between a display panel and its protective cover glass or touch panel is filled with a transparent optical adhesive.

In a conventional display assembly, the air gap between these layers can create additional internal reflections. When strong ambient light reaches the display, those reflections can reduce contrast and make the screen more difficult to read.

Optical bonding removes this air gap, creating a more unified optical structure between the display and cover surface.

For aviation applications, this can provide several important benefits.

1. Improved Sunlight Readability

One of the biggest challenges for aviation displays is maintaining readability in high ambient light.

Cockpit displays, cabin control systems, ground equipment, and other aviation interfaces may be exposed to direct or indirect sunlight.

Optical bonding helps reduce internal reflections between the LCD, touch panel, and cover glass. The result can be improved perceived contrast and better readability under bright lighting conditions.

When combined with a high-brightness LCD and appropriate anti-reflective surface treatments, optical bonding can be an important part of a sunlight-readable display solution.

2. Reduced Glare and Internal Reflections

Every optical interface within a display assembly can contribute to reflections.

A traditional air-gapped display introduces additional interfaces where light can reflect back toward the viewer.

By replacing the air gap with an optically matched bonding material, optical bonding can reduce these internal reflections.

This is particularly valuable in aviation environments where operators need to quickly interpret information without excessive glare interfering with visibility.

3. Improved Display Contrast

Increasing brightness is not the only way to improve display readability.

Contrast is equally important.

By reducing reflected ambient light, optical bonding can improve the perceived contrast between displayed information and the surrounding screen.

Text, graphics, instrumentation, maps, alerts, and other interface elements can therefore remain easier to distinguish in challenging lighting environments.

For many aviation applications, improving contrast can be more effective than simply increasing backlight brightness.

4. Increased Mechanical Durability

Optical bonding can also improve the mechanical integrity of a display assembly.

Bonding the display, touch panel, and protective glass together creates a more integrated structure compared with an air-gapped assembly.

This can provide additional resistance to vibration, shock, and mechanical stress depending on the display construction and bonding materials used.

For aircraft and aviation equipment that may experience continuous vibration or repeated mechanical loading, this added structural support can be valuable.

5. Reduced Risk of Condensation

An air gap creates an enclosed space where moisture can potentially accumulate under certain environmental conditions.

Changes in temperature, pressure, and humidity can make moisture management especially important in transportation and aviation applications.

Because optical bonding removes the internal air gap, it can reduce the opportunity for condensation to form between the display and cover glass.

This helps maintain optical clarity and can contribute to a more robust display assembly.

6. Better Touchscreen Performance

Many modern aviation interfaces incorporate capacitive touchscreens.

With an air-gapped design, the physical distance between the user's finger and the display image can create a noticeable visual separation.

Optical bonding reduces this separation and can make the display appear closer to the touch surface.

The result is a more integrated visual and touch experience, which can be valuable for cockpit controls, cabin management systems, portable aviation equipment, and other interactive interfaces.

7. Potential for Improved Power Efficiency

A common approach to improving sunlight readability is increasing backlight brightness.

However, higher brightness typically requires additional power and can generate more heat.

Because optical bonding improves readability by reducing reflections and increasing perceived contrast, manufacturers may be able to achieve the required visual performance without relying solely on higher backlight output.

Actual power requirements depend on the complete display design, but optical performance should be considered alongside brightness when optimizing an aviation display.

Where Is Optical Bonding Used in Aviation?

Optically bonded displays can be considered for a wide range of aviation and aerospace equipment, including:

• Cockpit displays

• Avionics systems

• Flight control interfaces

• Navigation displays

• Cabin management systems

• In-flight entertainment systems

• Aircraft monitoring equipment

• Portable aviation displays

• Ground support equipment

• Aerospace test and measurement systems

  
  

The appropriate display configuration depends on factors such as brightness, viewing angle, operating temperature, touch requirements, mechanical environment, optical performance, and applicable qualification requirements.

Optical Bonding vs. Air-Gap Displays

Air-gap construction can still be appropriate for applications where cost is the primary concern and environmental conditions are relatively controlled.

For demanding aviation applications, however, optical bonding can provide significant advantages.

Feature	Air-Gap Display	Optically Bonded Display
Internal Reflections	Higher	Lower
Sunlight Readability	Standard	Improved
Perceived Contrast	Standard	Improved
Condensation Risk Between Layers	Higher	Reduced
Mechanical Integration	Standard	Improved
Touch/Display Visual Integration	Standard	Improved
Cost	Lower	Higher

The best approach ultimately depends on the application's performance requirements and operating environment.

Choosing the Right Display for an Aviation Application

Optical bonding is only one part of designing a reliable aviation display.

Manufacturers should also consider:

• Display brightness

• IPS or other LCD technology

• Viewing angles

• Anti-reflective and anti-glare treatments

• Cover glass specifications

• Touchscreen technology

• Operating temperature

• Backlight lifetime

• Mechanical construction

• Vibration and shock requirements

• Long-term component availability

  
  

Evaluating these factors early in product development can help OEMs avoid costly redesigns and select a display configuration appropriate for the final operating environment.

Custom Optical Bonding Solutions for Aviation Displays

Interactive Display Solutions (IDS) works with OEM manufacturers and system integrators to develop display solutions for demanding applications.

Depending on project requirements, display solutions can incorporate technologies such as high-brightness LCDs, touchscreens, custom cover glass, optical enhancements, and optical bonding.

Rather than selecting a display based only on size and resolution, manufacturers can evaluate the complete optical, mechanical, electrical, and environmental requirements of their application.

Looking for an Optically Bonded Display?

If you're developing an avionics system, aircraft interface, portable aviation device, or other aerospace equipment, optical bonding can help improve display readability, optical performance, and environmental robustness.

Contact Interactive Display Solutions to discuss optical bonding and custom display options for your next aviation display project.

Published by IDS Display - Interactive Display Solutions, Inc.