|
|
|
|
|
01/02/2006
 Email to a friend
 Comment on this article
|
Infrared based night vision systems are likely to see rapid growth now that the technology has been tested and applied in a few high end vehicles. While the basic technology is now well understood, there are many less well-know technical issues that have to be resolved when designing a new system.
One of these is the need to separate infrared light from visible light and to ensure that only light in the desired wavelength range, between 780 and 1100nm, can pass through the headlight lens. Among other things, this prevents intense projected infrared light from causing eye damage to other road users.
Glass specialist Schott has developed optical interference filters to perform this task. These are composed of more that 50 thin dielectric metal oxide layers that are applied to the glass substrate using a high vacuum evaporation process.
Ion assisted deposition or reactive ion plating result in very hard and compact interference layers. As a result, these filters have excellent climatic resistance and the highly stable spectral characteristics required by headlamp developers.
The multi-layer system means the light has to pass through several layers. Incoming light is reflected at each interface between two layers.
The reflected rays of light then overlap as they leave the interference layer. This overlapping prevents the red impression of the headlamp while light within the permitted wavelengths can pass through without difficulty.
|
|
| |
Author
Roger Bishop
|
| |
| |
Copyright European Automotive Design.
See Terms and Conditions.
One-off usage is permitted but bulk copying is not.
For multiple copies contact the sales team.
|
| |
|
|
| |
To access the whitepaper section you need to complete our 60 second registration process. Once completed this then allows you to download any and all white papers, register for e-zines and access our detailed supplier directory for FREE.
If you are all ready a registered user then enter your e-mail address and login.
You will need to have logged in prior to entering your comments in the boxes provided.
|