Video Projector From An Old Single-slide Unit

Here’s a video projector that [Matt] hacked together. He needed a small and inexpensive solution to use with his R2D2 build. As you can see in the video after the break, it has no problem playing back the Princess’ distress call. But even if R2D2 is not one of the droids you’re looking for, we think this can be useful in other ways. One use that pops into mind is for projector-based Halloween displays.

As with past projector hacks, all you really need to pull this off is a light source, an LCD screen on which you can playback video, and a lens to focus the light onto a screen. Usually the LCD is the most expensive part of the project and building an enclosure to the correct dimensions can be a bit difficult. [Matt’s] solution was to use an MP4 knockoff media player. The rest of the setup is a ’50s era slide projector. The screen from the media player is about the same size as a single film slide, so he removed the screen from the case and put it where the slides go.


21 thoughts on “Video Projector From An Old Single-slide Unit

  1. Built a unit identical to this back in 1996; only problem is that the contrast of the LCD drops as the temperature increases. At operating temperature, the colors are so washed out as to be useless.

  2. I did a similar thing with an old slide projector and an lcd from a 1.5″ digital photo frame. The problem with these projectors are the bulbs get awfully hot. Some early projectors don’t even fans (like my old SVE Entertainer 300). I ended up replacing the 300w bulb with an LED. A lot safer (albeit dimmer), and still can be fanless, even fully battery operated.

  3. Its a nice hack,
    however to get it smaller you might consider a beagle board and a pico projector.
    Pico projectors clones goes for 100-150 Euros already.
    The beagle board could be used for other control purposes as well.

  4. Hah! A beagleboard and a picoprojector, really? At least $400 worth of kit to produce a single intentionally low-quality video? That’s not exactly in the spirit of keeping things cheap and simple. Besides, he says it’s just a proof of concept/test. The final version will use a custom case with and LED light source.

  5. “Help me Obi Wan Kenobi, I’m trapped in a slide porjector!” Nice, quick hack, but I agree about using an LCD instead of the bulb.

    @Alex – Good idea, I found an old LCD handheld TV at Goodwill, mabye I should make the world’s crappiest home theatre.

  6. how would one go about building a projector that could turn the moon into the hackaday logo, or some other logo.. pepsi.. How does one project darkness on an illuminated object?
    come on, hack reality. knock knock, Neo…

    what would be an awesome projector hack is if you were to shoot up a mist from the ground, in the dark, in a graveyard, for example.. project the Princess’ distress call there. mist shooting up from ground + wind + projector = the only time i saw a ghost, whether or not i was hallucinating, it was kind of like what would happen if you projected on a mist, only not 2d and there was no projection, because where there was no mist, there was no image, not on the walls or floor. i probably was hallucinating. chasing a puff of smoke rolling across the floor, that for some reason looked like an orange cat.

  7. Great hack. I’ve wanted to do this for years. I have a junk cellphone with cam, guess it’s up for the hack. I have plenty of lenses. There are critical optics with the light source. Save your old pentium heatsinks they will with their fans cool surface mounted leds in the high power range.

  8. I’d be interested in seeing how one of those ‘high power’ 20/30/50/100 watt LED arrays does in that setup, the prices of those LED arrays have dropped dramatically the past year or two to the point where they’re really worth investigating in regards to projector bulb replacements.

    I do remember seeing some pictures of projectors that had been modified to use powerful LEDs that cost a fraction of the price of the original £300 bulb and have significantly longer lifetimes, but don’t recall seeing any side-by-side pictures or video comparing it to a traditional bulb setup.

  9. Great Hack, I tried it also a few years back with a small photoframe (Sprite hack) and a dia projector. But after a few seconds the screen goes blank because of the heat.
    I should try a LED light source or cooling it down.

  10. I have a plastic Rear projection TV lens I need to do something with.

    For a video screen you can steal an Audiovox D1500A screen from an old DVD player. I had two, and one the CCFL inverter was on one end of the board and I could snap it off, the other was integrated with the LCD supply.

    Use a fan to keep the panel in the correct operating range. Just put it on the casing and cut some vent holes near the LCD, then the cold air will be drawn in over it.

    Another option would be a Palm Tungsten or Zire color with Core TCPMP. they accept 1GB SD cards and can play Xvid/Divx

  11. take this idea and the animation wheel from a few days ago, one of those cheap keychain lcd photo things (or a salvaged lcd with better resolution) and switch the projector to an old 8mm film projector and you’ve got yourself a digital/analog film projector which can display more than 50 frames. You don’t need video playback either, just be ale to switch the images on the lcd at the same rate as the shutter on the projector. It would be a great player for time lapse projects.

  12. @Alex
    Well I don’t know from which place on earth you buy your stuff, here in Japan the cheapest projector comes for $85 the beagle board for $125 (the older one) which sum up to be $210.
    Taking into account that you have totally overpowered platform, you could simply add much more capabilites over time (play and record audio, control servos, wifi/bluetooth, etc.). This might be not a bad deal.

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