LCD Overhead Projector

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Introduction: LCD Overhead Projector

About: I'm working on my Master's of Science in Mechanical Engineering, specializing in Engine Research at the University of Wisconsin - Madison. ***All Instructables Projects moved to my personal site, I didn't li...

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      user

      We have a be nice policy.
      Please be positive and constructive.

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      84 Comments

      Would the Liesegang trainer portable T work?It shines from above and replaces the clunky frame with a slim mirror.

      Hey, I've got a slim ohp here that shines the bulb down and mirrors it back up. Would it work the same? I got the ohp for £20 and it would be great as it is slim. It is this projector: http://www.vega.si/eng/?template=product&art=9 I hope this works as it would be the cheapest projector ever...
      Luke

      would it be possible to do a similar thing but use a high power garden lamp and mirrors because i don't have a ohp

      1 reply

      The overhead projector does a few things the garden lamp doesn't. The mirror at 45* angle in the overhead projector base the bounces the light through the LCD actually passes the infrared light through it (making the other instructable having you add a IR Filter not necessary). The optics on the "head" of the ohp actually project the image, if you passed it through the garden lamp you'll be much more dependent on the distance and geometry from the screen you're projecting on. The reason that ohp bulbs are special is that they give off light in a broader "flatter" spectrum, meaning the light coming out of them is balanced and won't discolor the images, if you're a huge movie/display buff you'll likely hate the results, if you're just looking for a big screen to watch movies on and don't really care the difference in spectrum isn't the end of the world.

      That said, there isn't any reason you can't do this, you can add an IR filter (or just have more cooling capability), and you can place it an appropriate distance from whatever you're projecting to.

      would it be possible to do a similar thing but use a high power garden lamp and mirrors because i don't have a ohp

      hey waterppk my name is adin and im attempting to build one of these projectors from your guide. I have gotten to the step that requires me to extend the LVDS cable. Thanks to your comment to ongissim i was able to find the extension cable on digikey. Now i have the cables but am wondering where to go from here... What type of wire do i need to use to connect the parts, and how exactly do i do this, hey thanks a lot in advance -Adin PS please respond here or email me at adin99@gmail.com Thanks!

      I have the same problem with the FPC cable being in the way of the screen. However, when I search Digikey, I can find the connectors, but not the 16 pin cable. What was the model number of your cable? Also, was your pin pitch .5mm?

      2 replies

      My pitch was .5mm, I was only able to get a 20 pin cable, which i trimmed the 4 pins off the side and carefully align it whenever I need to unplug/plug it back in. It's been working well.

      You can find them in the DigiKey PDF catalog, but I wasn't able to find them online through their search. Download the catalog section A and scroll to page 85, on the left hand column you should find .5mm pitch cables in fixed lengths (max 8 inches).

      If you have to search the cables are called -
      0.5mm Pitch Standard Length Jumper Unshielded Flat Flex Cable

      PM me if you need any more help with anything.

      hey waterppk my name is adin and im attempting to build one of these projectors from your guide. I have gotten to the step that requires me to extend the LVDS cable. Thanks to your comment to ongissim i was able to find the extension cable on digikey. Now i have the cables but am wondering where to go from here... What type of wire do i need to use to connect the parts, and how exactly do i do this, hey thanks a lot in advance -Adin PS please respond here or email me at adin99@gmail.com Thanks!

      i tried to make one, but the lcd screen wont stay on. it flickers on and off, anyone know how to fix this problem?

      I made one and it works perfectly, apart from a white line of dead pixels down the screen because one of the screen address cables got damaged :( Nice instructable!

      user

      cant you just replace the bulb in the projector with a worklamp light bulb, it would get much brighter, right

      4 replies

      You can replace the bulb in the projector with something else, but it probably wouldn't be any brighter.

      The reason for using projector bulbs is that they are typically quite bright but most importantly color balanced and focused. If you were to stick a work light halogen bulb or something in the projector you'd be dumping half of the light in the wrong direction, would get bright/dark spots on the screen and the color balance would be wrong because the light spectrum would be shifted. (That's a comparison between LED's and CCFL's but you get the idea). Another potentially dangerous problem is improper cooling, halogen bulbs typically have more IR output than projector bulbs and may not adequately be cooled by the normal fan.

      user

      ohhh, ok i uderstand what your saying, i was asking cause im gonna use my lcdprojector for a multi touch computer screen,

      https://www.instructables.com/id/Back-projection-56-inch-multitouch-television./

      i dont want to use a worklamp bulb if it has more IR output then a projector bulb, because it would mess with what the multi touch input, is their a brigther bulb i can get because i want a really crisp picture....

      You could take a shot with Metal Halide, they will put out around 20,000 lumens and will be close to white light which is 5000K. Either way you need to take a IR filter and put on the front of them. Because if you use a Worklight you are putting yourself at risk with the amount of IR that comes of them. Worklight will put you at risk of getting sun burn without the IR glass filter. I think the same is for the Metal Halide.

      Just to clarify . . . There is no real exposure risk from the infra red (IR) from the lamps. The real hazard is ultra violet (UV). Metal halide and halogen both have integrated UV filters. The real problem with these high-output lamps is the IR can damage the LCD. Overhead projectors have a filter in them and they use a dichroic mirror that allows the IR to pass through the back and reflects the rest. If you've been to the dentist you've seen a dichroic mirror.

      can i use 3m the five "o" eighty eight to build a LCD video projector thank's

      1 reply

      I don't see why not, looks like a smaller/more portable version of a typical projector. Good Luck!

      Just a random thought but would a portable DVD Player LCD be able to do this as well? That would be cheaper and nice for a stand alone unit without the computer.

      a. i bought a RCA to VGA adapter cable thinking i could run it from the cable box to the monitor but now i see (a little lower on the comments) that probably won't work...what would you suggest to run my cable rca output to the monitor? b. i cannot figure out what to do about the ffc cable...what do you suggest? it seems like i could solder directly to the board on one side but the other one has a connecter the cable used to slide into. any thoughts?