(VFD) Panel-filter

Remove the backlight from an LCD and use it as a selective-color-filter for various instruments and a VFD!

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Vacuum Fluorescent Displays are pretty awesome.. They lend themselves well to color-filtration, so why not add *selective* color-filtration using an old LCD panel as an overlay? And since there's so much extra space on the LCD maybe throw in some other groovy instruments, gauges, indicator-lights, and maybe even an oscilloscope.

VFD + LCD = (sectionally-) selectable color filtration

Yeah, Got this ancient VFD, 40x2. I do like the nice glow these things have, and the sharp contrast... And the ability to use color-filters...

I tried it out once, throwing an old laptop panel in front, with its backlight/back-panel removed... it seemed to do quite nicely. I kinda dug the 3D aspect of it, as well... the "display" being more of a window... the overall shape being somewhat more "square" and hiding the fact that the VFD is distinctly rectangualar... Could throw other things back there, too, LEDs, whatnot. Even stencilled lightbulb covers, and selectable color-filtration for those as well... even lighted circuitry... Who knows, maybe color-filtered Nixies... or those 7-segment incandescents... The list goes on. The depth... I kinda dig it. The irony(?) of the ancient and new technologies; the new being capable of *all that* the old is doing, yet being used for little more than could be done with a simple color-wheel. Awesome.

(And, I've already been using an ATtiny85 to drive laptop displays with nothing more than a couple TTL XORs, its limited memory and slow-refresh lends itself perfectly to a project like this. #my very first binary-clock)

Also, found some recent inspiration from #HD44780 LCD Graphics that *might* be implementable on this VFD. This cat... holy schmoly.

As far as *what* this UI will be for...? That remains to be determined.

(oh, and maybe something about a clear-capacitive-touch-overlay? Or a light-pen!)

Additional considerations:

Have been wondering what'd happen if an LCD is cut horizontally (e.g. with a glass-cutter), might lend itself well to better-fitting the VFD. I think some displays could handle it, depending on the design)

Possibly have a lit/"white" background (somewhere a little below the LCD for 3D/floating-effect) and use a *portion* of the display for text/graphics... not sure.

  • Color filtering B/W CRT

    Eric Hertz05/12/2021 at 03:24 0 comments

    Yes! Second time I've watched this in a couple years,  each time sorta-inspired, with no idea what to do with it... but 10fps isn't /horrible/, so a pi's composite-out and some sync logic could prb get similar going with e.g. a camcorder's tiny viewfinder CRT... throw that on the ol' artist's rendition control/display panel. Or maybe even an old portable B/W TV around 4-5in....

    Or maybe some hackery could bump up framerates, or maybe Black/OneColor is just as good, varying with the image... e.g. a simulated nimo tube with low values in green and high values in red....

    I still wanna do this display/filter someday...

    EDIT: LOL I already had a CRT in the artist's rendition... with an old oscilloscope, duh.

  • Oh no...

    Eric Hertz10/23/2015 at 15:03 0 comments

    200 tiny lightbulbs for $5... More ideas...

    These are the ones for "maglite" flashlights, I think... 1.5V, *really* bright... But if I put 'em behind this panel, I think I'd drive 'em pretty dim, get that nice "warm" glow, so the filaments are viewable...

    So, what...? Another "matrix" display, probably... I do seem to have a thing for using older technologies for newer things we see every day. But I guess I could be more creative... And it's not like scrolling incandescent text-ridden signs never existed, anyhow.

    Incandescents are/were used in old signs, of course. maybe something like a scrolling border... I dunno.

    I kinda dig *How* they were driven, they seem to imply a computer of sorts, but sometimes they simply use a spinning drum with a bunch of nibs sticking out that push microswitches, just like a music-box. Kinda cool, since you can *see* the pattern in the "Memory"...

    OTOH, again, "maglites" are pretty-durn-bright... and 200 of them would be a lot of light...

    I've been thinking, ever since I started messing around with really-simple LCD-driving circuits, that one potential use is as an easily-adjustable filter for e.g. stage-lights.... One of my LCD-driving circuits is nothing more than a shift-register, a crystal, and some DIP switches to select a solid color to fill the screen. (Could probably get rid of the shift-register altogether, if using a Parallel-interfaced display, rather'n an LVDS one).

    I don't need a stage-light, per se... but mood lighting might be cool... shine it on a wall... 200 flashlights should be bright enough, eh? And, again, with the "warmth" of incandescents... Hmm...

  • Various thoughts and blinky things

    Eric Hertz10/01/2015 at 16:45 0 comments

    Took apart an old green backlight for an ASCII LCD... I happen to have 7 of these, about 4 inches long, 1 wide. The backlight contains a shitton of bare green LED dies behind a filter that's easily removed. They're pretty when lit. I just happen to have 7, so might have to make a seven-segment display outta them. And, who knows, maybe throw it behind this LCD for fun.

    On that note, also have a "bubble display" which has a similarly-pretty aspect, being that the LED dies are visible. Something about these point-sources are drawing my attention.

    On *that* note, also have an old LED display from an old cell phone... it's seven digits of 5x7 (again bare-die) leds. The interface is undocumented, and it's controlled by two epoxy-blobs, but amazingly they put test-points for every row and every column. Driving the rows and columns directly apparently lends to feedback through the epoxy-blobs, as driving one dot ends up driving most of a column. So I might end up seeing if I can scrape the epoxy-blobs (and the silicon underneath) off the PCB entirely. Again, bare-die LEDs, pretty.

    And then, just came across this as a nice surprise... Wanted to see what was inside a TO-3 (can) transistor, but hadn't the patience to actually do-so...

    No kidding, the tiny thumbnails don't do it justice, look at it zoomed-in, it's quite cool looking, like a tiny neon sign.

    Maybe a magnifying glass under the LCD, who knows.

    As far as the LCD color-filter... Well, with LEDs, of course, there isn't likely to be much interesting filtration, but who knows. If nothing else, there's the aspect of turning it "black" when the displays behind it are off, to hide the details, or masking the circuitry, etc. I don't know yet. The VFD color-filter, on the other hand, well, that just makes complete sense. And, yeah, I've come across a few old VFDs from VCRs, etc. that would be quite groovy (again, I kinda dig the custom-shape stuff they're good at).

    Speaking of cool-shaped VFDs.... Did I show you this?

    d'aww... looks like I missed-out... They were really cheap, too. Not that I'm a car buff, but c'mon, probably the closest to a Corvette I'd ever own ;)

    Oh, and did I mention that I have a couple incandescent 7-segment displays? How cool is that concept? Those should be fun with color-filtration.

  • Woot! An award!

    Eric Hertz07/17/2015 at 06:10 0 comments

    The competition was fierce, I'm honored this was deemed a worthy Human-Interface :)

    $100 in free laser-cutting from!

    I've plenty of ideas of how to make use of it! An enclosure, of course, but I've no doubt more ideas will come in the not-too-distant future.

    Thanks HaD and ponoko!

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