Wednesday, 6 June 2012
I had a bit more of a play with the laser scanning unit, this time with the laser from a Blu-ray player. These units kick out something around the 100mW range. I rather stupidly bought a new blu-ray player just to get the laser, the idea was to have something to play with over this epic 4 day weekend. Turns out I did not have the components to build a proper drive for it anyway. I decided to try it on a normal current limited PSU, a bit sketchy as I know it produces current pulses when you turn it on but I was careful. The laser did not come on! But later I found that my laser has an unusual pin out and also that it needs over 4v to get it to turn on, quite a surprise. It turned on and seems quite compatible with the scanning unit, but it was pretty bright even at 20mA so I decided to give it a rest until I get some proper goggles, better safe than sorry. Similar diodes on ebay are £7 a pop so now I am not in a rush it will be a cheaper affair all together. Also looking for a high speed driver circuit, if A4 is 210mm wide and we consider an aim of around 1200dpi then we are talking over ten thousand pulses per scan and the scanner can probably do up to 10000rpm and has 6 facets, the pulse rates are pretty high (around 10Mhz). Not sure of the best approach electrically, there are some dedicated driver chips but that might be overkill.
Yep, I've started collecting animated gifs when I see them on imgur, this one seemed to fit nicely!