Optical Bonding Technology

1. Main Factors affecting Outdoor readability

Why you cannot see the display near the sunlight? We have listed some major factors that affect your display's readability near sunlight. And our corresponding solutions.

Reflection of light may be specular (that is, mirror-like) or diffuse (that is, not retaining the image, only the energy) depending on the nature of the interface.

Too dark!

Need Brightness enhancement

  • Transflective
  • High Brightness

Glare / Mirror image!

Need to reduce reflection

  • Optical bonding with AR glass

Color wash-out!

Need to reduce reflection

  • Optical bonding with AR glass

Optical bonding helps you to reduce the Reflection Problem


2. How does Reflection happen?

Optical bonding is mainly dealing with the Reflection. Now let's look more detail on how reflection happens and the law of reflection. Reflection is the change in direction of a wave front at an interface between two different media so that the wave front returns into the medium from which it originated. Common examples include the reflection of light, sound and water waves.

Reflection of light may be specular (that is, mirror-like) or diffuse (that is, not retaining the image, only the energy) depending on the nature of the interface.


Specular reflection, souce : Wiki

Diffuse reflection, source : Wiki

When light moves from a medium of a given refractive index n1 into a second medium with refractive index n2, both reflection and refraction of the light may occur.

Refraction of light waves in water. The dark rectangle represents the actual position of a pencil sitting in a bowl of water. The light rectangle represents the apparent position of the pencil. Notice that the end (X) looks like it is at (Y), a position that is considerably shallower than (X).


Variables used in the Fresnel equations

Law Reflection

It states that the direction of incoming light (the incident ray), and the direction of outgoing light reflected (the reflected ray) make the same angle with respect to the surface normal, thus the angle of incidence equals the angle of reflection; this is commonly stated as θi = θr.

Law of Refraction (Snell's Law)

Snell's law states that the ratio of the sines of the angles of incidence and refraction is equal to the ratio of velocities in the two media, or equivalently to the inverse ratio of the indices of refraction.


3. How much Reflection happens?

The reflection is caused by the difference between material’s refractive index. The larger the difference, the bigger the reflection happens.


Fresnel equations


  • When light moves from a medium of a given refractive index n1 into a second medium with refractive index n2, both reflection and refraction of the light may occur.
  • The fraction of the intensity of incident light that is reflected from the interface is given by reflection coefficient R.

Calculation of reflection

  • Refractive index
    1. Vacuum air - 1
    2. glass - 1.5
  • In this case, the reflection coefficient is about 4%.

4. How Optical bonding can help reduce Reflection?


Calculation of reflection:


  • Refractive index
    1. Vacuum air - 1
    2. glass - 1.5
    3. Adhesive - 1.474
  • he reflection between the glass and the adhesive is close to 0%.

By using the Adhesive whose refractive index is very close to Glass and Panel (Polarizer glass), it can help to reduce the reflection happen when light transmit through glass and panel.


5. Reduce Reflection help improve Contrast

Now you have known that our optical bonding can help to reduce the reflection. Furthermore, we will show you how the reduction of the reflection and help improve the "extrinsic" contrast ratio and therefore help the outdoor visibility.

  • "Brightness" lightens or darkens the image. "Contrast" changes the distinction between the light and dark areas.
  • The human eye eventually becomes saturated with brightness and becomes more responsive to contrast.
  • Contrast ratio is much more significant than brightness in high ambient illumination environments.



Reference data source:
https://en.wikipedia.org/wiki/Reflection_(physics)
https://en.wikipedia.org/wiki/Refraction
https://en.wikipedia.org/wiki/Refractive_index
https://en.wikipedia.org/wiki/Fresnel_equations


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