crwdns2933803:017crwdne2933803:0
crwdns2933797:0Miroslav Djuriccrwdnd2933797:0crwdne2933797:0
- crwdns2933769:0crwdne2933769:0
- crwdns2933771:0crwdne2933771:0
- crwdns2933801:0crwdne2933801:0
crwdns2933807:0crwdne2933807:0
| - | [* black] The glass over the E-ink screen takes the light from the eight LEDs at the top and evenly distributes it across the screen. |
|---|---|
| - | [* black] How you ask? |
| - | [* black] The glass is specially designed using a core principle of optics: [http://en.wikipedia.org/wiki/Diffraction|diffraction]. |
| [* black] Light coming from the LEDs goes into the glass, which contains a [http://en.wikipedia.org/wiki/Diffraction_grating|diffraction grating] -- an optical component that has slits or grooves as part of its structure. Usually a diffraction grating is a separate piece of an assembly, but B&N's engineers integrated it into the glass. | |
| [* black] This diffraction grating bends and disperses the light throughout the screen. Barnes and Noble really did their homework on this one, because instead of a simple linear diffraction grating (think of a bunch of parallel slits), the diffraction grating appears to change throughout the glass to evenly disperse the light. | |
| [* black] How do we know its a diffraction grating? | |
| [* black] [http://shaktronics.com/files/2010/02/big-scary-laser.gif|Lasers]. We took a laser and beamed it through the glass panel onto a wall. Unlike the light of the white LEDs found on the Nook, you can see the diffraction pattern in the picture projected onto the wall (diffraction grating acts like a prism). If no diffraction grating was present in the screen, the laser would still be projected as a singular dot on the wall. |