[bitluni]’s laser-based display pretending to be a an old-school vector CRT.Phosphor-based displays like CRTs rely on the phosphor to emit light for a set amount of time after being activated, allowing them to display a seemingly persistent image with one drawing beam per color. Translated to UV-sensitive PLA filament, this means that you can totally use a printed sheet of this material in combination with a 405 nm laser diode to create a display that doesn’t look dissimilar to an early CRT. This is exactly what [bitluni] did in a recent video, meshing together said laser diode, UV-sensitive PLA, stepper motors and two mirrors with an Arduino-based controller to create a rather interesting vector display.
In the video, [bitluni] goes over the development steps, including a range of improvements like being able to turn off the laser when moving between the end of a line and the beginning of a new one. While the Arduino Nano board does the driving of the stepper motor controllers, an ESP32 provides the drawing instructions. The STL and other project files including Nano & ESP32 firmware can be found on the GitHub project page.
While far from being a practical display with a single-digit Hz refresh rate, it does provide an interesting demonstration of these types of persistence of vision based displays, and without the use of exotic MEMS mirror modules or the like.
6 thoughts on “A Laser With Mirrors Makes A CRT-like Display”
Ooh. Now I want to make a SSTV display like this, mimicking the olde P7 phosphor CRTs.
If they had high-quality full color lasers and galvos back then, they probably would have never bothered with the whole vacuum thing. But it sure is a lot easier to quickly steer a charged particle
Thing is, they used vacuum tubes to figure out what electrons and atoms were, so one kinda follows the other – can’t get a laser diode before you build a cathode ray tube.
This is a delightful project. I loved the successes and missteps. When I was a kid I remember going to a laser light show at the local planetarium. I believe the solution they use there is to spin one mirror at very high speed, and turning the laser on and off as Bitluni does here at the end. I think a high-speed spinning mirror overcomes the issue with trying to manage the stepping at a very high rate.
Ooh. Now I want to make a SSTV display like this, mimicking the olde P7 phosphor CRTs.
If you play carelessly with the intensity, bye bye Alderaan.
Milimeter by milimeter.
If they had high-quality full color lasers and galvos back then, they probably would have never bothered with the whole vacuum thing. But it sure is a lot easier to quickly steer a charged particle
Thing is, they used vacuum tubes to figure out what electrons and atoms were, so one kinda follows the other – can’t get a laser diode before you build a cathode ray tube.
this is basically ldp, and this company manufactures them and i thinks has the patents https://www.prysmsystems.com/displays/lpd-6k-series/features/
This is a delightful project. I loved the successes and missteps. When I was a kid I remember going to a laser light show at the local planetarium. I believe the solution they use there is to spin one mirror at very high speed, and turning the laser on and off as Bitluni does here at the end. I think a high-speed spinning mirror overcomes the issue with trying to manage the stepping at a very high rate.