View Full Version : RGB working again, strange halo around blue after dichro ?

10-17-2011, 11:09
Hi All,

With help of Edison and Badpip i got my projector running topnotch again, will do a powermeasurement in a few minutes, but saw one strange thing.

My selfbuilt blue module outputs a nice round dot around 3.5 to 4mm if i hold a piece of white paper in front of the module.
Then i hit the dichro (pass green/red and reflect blue) if i place the paper in the blue beam AFTER the Dichro, is see the small dot, but around it is a elleptical shape like a halo.
This ellips is really big, like 1.5cm tall and 1 cm width.

If i project text this halo is very present. for instance if i project the IBM logo there's a 4cm blue edge around the text. Much lighter, but not as we like to see it.

The only thing i can thing of is that i drilled a small hole in the front panel of the module to let the beam through, maybe the beam hits the sides of this square hole i filed and spreads the light ?

That's one thing i will try, since it is working, but if i can make it better, i like that ofcourse ;-)
If someone recognizes this , i am all ears.

EDIT: I will take the front of the module off AFTER the show i have friday. I put some coolingpaste (dealextreme) between the module and the nice anodized blue baseplate.
After removing the screws i could not get the module of the baseplate, stuck like a priests hand on a small boys arse ;-)
So that will have to wait.