Homebrew PCBs

Volkan Sahin wrote:
>  

> I added laser to the side of inkjet head and I'm using raster scanning 
> method to expose photoresist.
> I've the same idea to use polygon mirrors of a old laser printer. I've 
> one Brother printer which has an aluminum mirror (most of them have a 
> copper or gold plated mirror on  aluminum because of IR laser) and 
> plastic lenses it seems it is possible to use with blue laser. I did 
> some rough measurements and I saw that on optical path I'm loosing ~30% 
> of the power most of it is because of diagonal mirrors because of that I 
> left it for a future project.   
> 

The polygon mirror concept sounds more difficult to implement.
How about a large diameter disc with a laser diode mounted on the 
perimeter. The PCB moves linear to the disc. Software would compensate 
for uniform exposure energy.

Assume that:

Resolution	= 0.005cm (50um)
Disc diameter 	= 15cm
Energy 		= 60mj/cm^2
Laser power 	= 85mW

Then

maximum disc RPM
	= 60 * 1cm/0.005cm / (60/85 * 15*1)
	= 1133

1000 RPM sounds reasonable.