Thought that would get your attention.
25 year old laser printer turned into a pumpkin, so true to form before I trash/recycle any equipment -
I eviscerate it for the education/parts.
This was special, because there is a laser in it… and I would have it.
The laser is at the top, and passes through a small lens before striking a rotating “mirror” that directs the beam to the left. It spreads the beam to paper width passing through two more lenses and hitting a mirror that directs the beam down to fuse the toner to the paper.
Those are are cool. I have never been able to resist gutting them, and have yet to figure out what to do with all the parts. The aluminum mirrors are awful purty though.
The laser does not actually fuse the toner directly. Instead it is used to discharge areas of an electrostatically charged drum. The toner sticks wherever the laser does not hit, and then the drum transfers the toner to the paper. The fusing is done in a most prosaic manner by a little electric heater.
Just to save folks from doing a search, here is a good post to let you know that lasers used in laser printers for making images on paper are very low power diodes that really don’t have enough in them to do the engraving cutting thing. DVD diodes can be coaxed into that kind of service, but it’s tricky. and yes, @jkopel, it IS still a laser and I’ve taken them apart for them just to look and say, here’s a laser on my desk.
Also back from the good old days, I have Apple LaserWriter II Service training. I still recall when the first LaserWriter came out, and the magic that was no longer dot-matrix printing of documents. Also much scratching of the head trying to learn Postscript, back when esoteric computer languages were a thing I was into.
Thanks for the explanation. Digging further I discovered the “fuser” is a tube with a quartz bulb inside to provide the heat.
Amazing to me that the spinning reflective surface accurately casts the image of text that fast. A bit more complicated than I imagined.
@nunzioc, Nice one there! I know the green have some specific applications, astronomy is one. A favorite thing for the hand held is to shine them into the distance in a snowstorm at night.
Another is lighting up the stop sign down the corner from my house when traffic approaches. The traffic control signs have a layer of very fine flint shot (sometimes called glass beads) that diffuse the laser quite effectively. Looks like the sign is back-lit.
Thanks for the link @marmak3261! Saved me some digging.
@dan, they just dont build 'em like they used to. So you have been playing with lasers for a long time!
I’m sure that power supply was a fun education. What did you guys do with your creation?
It would be neat to see a picture of that, next to your latest - greatest!
Yes @dan_berry! At the time, I was bucks-up so I splurged on a laser printer. It was space-age next to dot matrix!
Man those things were loud!
My father worked for Xerox in the '70s and I remember going on a tour of their facilities and hearing them talk about copiers printers that used LASERS!
It was a very exciting thing at the time, I guess it still is.
Here’s a fascinating story of the early days of digital typesetting. In this case Bell labs reverse engineering a CRT typesetter. What amazes me is that in the history of printing a new technology could so quickly disrupt the marketplace.
Very resourceful. Made you a popular guy I’ll wager. Probably put a further bind on time available to sleep… kinda like now.
I notice you’re active around the forum in the wee hours. The days are long and the years are short.
