hacking an old laptop into a 3d projector
TRANSCRIPT
http://www.instructables.com/id/Hacking-an-old-laptop-into-a-3D-projector/
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Hacking an old laptop into a 3D projectorby naimo on September 19, 2013
Table of Contents
Hacking an old laptop into a 3D projector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Intro: Hacking an old laptop into a 3D projector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Step 1: The trick . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Step 2: Material needed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Step 3: Building the box, mounting the lenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Step 4: LCD stripping & mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Step 5: Fabricating the lightbox . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Step 6: Testing the projection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Step 7: Adding polarizing filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Step 8: Finishing the box, mounting the electronics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Step 9: Taking it all apart, staining the wood, adding details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Step 10: Putting it back together ! . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Related Instructables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Advertisements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
http://www.instructables.com/id/Hacking-an-old-laptop-into-a-3D-projector/
Intro: Hacking an old laptop into a 3D projectorIf you have an old laptop lying around, and are looking for a DIY adventure, this might be the place for you. I'm going to describe how you can go about building your veryown 3D projector !It's not for the faint of heart, and I can't possibly get into every bit of detail, but I'll try to link all the resources you will need.
It all starts on DIY projector forums, such as Lumenlab (which is now only accessible via the Wayback Machine), DIYaudio , or if you understand French, Allinbox . Thefolks on these forums pioneered the idea of reusing an LCD screen into a high quality, affordable, videoprojector, by using a very bright lamp as light source and findingthe proper optics to make the magic happen !There are already a few instructables (here , here , and here ) based on these designs, and other external resources (here and here ), so I'm not going to spend toomuch time on the technical aspects of building a regular 2D DIY projector. Some companies are even selling kits based on those ideas.A DIY projector is a challenge in itself, but if you're really motivated, you can go one step beyond, and make it 3D !
A first idea is to use two projectors, commercial or DIY ones, place some polarizing filters in front of their objectives, and align the images on the screen so that theyoverlap. This has also been proposed in previous instructables , in some forums and other blogs .
However if you have only one LCD screen, you can still pull it off, with a little trick.
Step 1: The trickThe trick is to consider the two halves of your LCD screen as two separate screens, that you need to project using separate optics. In my case, I decided to rotate my15.4" LCD screen so that the height is the longest dimension, and consider the top and bottom halves as separate screens.
It is then possible to cut the Fresnel lenses and place the objective lenses such that the projected images are superimposed on the projection screen.It's relatively basic geometry and linear optics : first calculate the throw of your projector and the size of your projected image using the same equations as for any 2D DIYprojector, then determine the position of the center of the objective lenses (triplet lenses) that will offset the two projected images so that they overlap as in the pictures Iuploaded.
The values shown in the images correspond to my 15.4" LCD screen, my 330mm focal fresnel lenses and 327mm focal objective lenses. However, the dimensions of thebox and relative position of the different optics depend on the dimensions and specifications of the elements you have, so don't just reuse those values, you'll have torecalculate them.I have a little script on my website (it needs the Mathematica plugin, sorry), which allows you to play with different parameters and see how it changes the dimensions ofthe box and the relative positions of the optics.
Image Notes1. Overlap of the two images on the projection screen2. Inside of the projector box Image Notes
1. Second fresnels lenses F22. LCD screen3. First fresnel lens F14. Condenser lens5. Lamp6. Objective lenses
http://www.instructables.com/id/Hacking-an-old-laptop-into-a-3D-projector/
Step 2: Material neededHere's what you'll need for this project
Your old laptop, with a decent quality (color!) LCD screen, its power supplyWood panels (plywood, MDF)Lamp and its power supply (metal halide, LED, your call) : good color and intensity are the main requirementsFresnel lenses, one on the lamp side, two on the projection side : make sure to get them in the right size and with the right focal lengthTwo triplet (projection) lenses : get the right focal length depending on you projection throw and image sizeReflector and condenser lens : to increase the light intensity and homogeneityLexan sheet to protect the optics from the heat of the lampCables, switches, connectorsTwo or more copmputer fans and a matching power supplyFilters : half wave plates and linear polarizing filmsAluminum and wood scraps, fasteners for mounting the different elementsWood finish (oil, varnish...)A projection screen compatible with passive 3D (like a Dalite Silverlight)
Step 3: Building the box, mounting the lensesAfter selecting your optics (fresnel lenses, triplets), based on the size of your LCD screen, your projection length and screen size, you should have a good idea of thedimensions of your box. I built mine in 1/2" plywood for the side panels, and 3/4" MDF for the front and back.
Cut and mount your Fresnel lenses inside the box at the right position. I cut mine at the same width of the box, to be able to just slide them in with proper guides made ofwood scraps.
Open apertures in the front panel of your box, and mount your projection lenses. It's good to leave some room to adjust their position at the end, to correct formiscalculations and inaccuracies in the fabrication. For that purpose, I allowed the small panels that hold my triplets to move up and down thanks to knobs that I cantighten manually.
Image Notes1. Plywood2. MDF
Image Notes1. Lexan sheet and lamp-side fresnel (F1)2. Future position of the LCD3. Guides for the projection side fresnels (F2)
http://www.instructables.com/id/Hacking-an-old-laptop-into-a-3D-projector/
Image Notes1. Sliding mechanisms to align the objective lenses
Step 4: LCD stripping & mountingTake the LCD screen out of the laptop. Very carefully, strip the LCD screen so that you are left with only the PCB and the LCD sandwich itself. Check this Lifehacker link ,or this engadget link for more information on how to strip a LCD screen.
Mount your LCD screen in between the fresnel lenses. There are many great ways to do this in the 2D projector resources I mentioned. I once again used some woodscraps, cut in the right shape, to maintain my LCD screen.
With the fresnel lenses and LCD in place, you know have two separated compartments in your box. The lamp is in the back compartment, so I suggest you place all yourelectronics (laptop, power supplies) in the front one so that they don't suffer from the heat of the lamp. However, make sure that the electronics are not in the way of thelight !
Image Notes1. These ribbons are very fragile2. These ribbons are even more fragile !
http://www.instructables.com/id/Hacking-an-old-laptop-into-a-3D-projector/Image Notes
http://www.instructables.com/id/Hacking-an-old-laptop-into-a-3D-projector/
1. LVDS cable between the laptop and LCD screen
Step 5: Fabricating the lightboxThe lightbox is one of the crucial elements of any DIY projector. Once again the resources I mentioned on 2D projectors will help you design it based on the type of lamp,the reflector and the condenser lens.
After making a quick 3D model of it, I built mine in 1/4" aluminum sheet, cut using a waterjet. It holds the lamp socket, the IKEA bowl that I use as reflector and my 9mmdiameter condenser lens.
At this point, a good sanity check is to verify that you obtain two images of your lamp by your set of lenses, which are roughly focused at the location of your triplet lenses.This will tell you if your fresnel lenses are well cut and positioned.
You can see that I mounted two fans at the back of the box, which extract the heat produced by the lamp. The air enters through an aperture on the side of the box, flowsin between the LCD screen and the fresnel F1 to cool these elements first, before entering the back compartment of the box.Cooling is a crucial part of any DIY projector using anything else than an LED lamp.
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Image Notes1. Notice the presence of fans to extract the heat from the back compartment ofthe box.2. Light box in operation
Image Notes
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1. Apertures where the objective lenses are mounted. The light if well focused atthe center.
Step 6: Testing the projectionOnce the lamp, lenses, LCD and laptop are in place, it's time to test the projection.
First, determine the throw by obtaining the best focus of your image on the screen. You should be able to see the pixels of your LCD screen since they are nowmagnified.
On the software side, regular 3D video streams have to be edited so that the images corresponding to the right and left eyes are displayed on the two halves of the LCDscreen (consider it as two screens). AVIsynth is a great utility to do video editing, and in particular to take two video streams and stack them vertically or horizontally intoone combined video.You can start by making a static test image to be displayed fullscreen on your LCD. I made one with a few rectangles and a letter A or B in the center, to verify myalignment.
If you calculated correctly the position of your lenses, you should be able to obtain, on the screen, a good superposition of the images formed by the top and bottomhalves of your LCD.If this works, congratulations, the hardest part is done !
Image Notes1. Good overlap of the two images
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Image Notes1. The two images of a 3D stream mainly differ in the background.
Step 7: Adding polarizing filtersSo that the image can be watched with regular 3D cinema glasses (like IMAX 3D), the light passing through the two objectives has to be polarized in perpendiculardirections.
The good news is that the light coming out of our good old LCD screens is already polarized, so we just need to rotate the polarization in two different directions to obtaintwo images polarized perpendicularly. The next good news is that this is exactly what a half wave plate does !Just stick two pieces of half wave film before or after your objective lenses, and rotate them around until the light is correctly filtered by your 3D glasses. Since these halfwave films are usually slightly chromatic (they rotate the light differently depending on the color of the light), it is probably good to add a linear polarizer after the waveplate to filter out any light that is not properly polarized. I hope that the uploaded picture makes things clearer.
And there you go, all you need is a projection screen compatible with "Passive 3D projection" (ie based on polarization of the light), and you'll soon be able to watch yourfavorite 3D movies at home.
Image Notes1. Incoming light2. Rotated light
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Step 8: Finishing the box, mounting the electronicsWhen everything is in working condition, it's time to finalize the box.
Properly mount the electronics in the front compartment, where it's cold, secure the cables along the walls so that they don't move in the path of the light. Add someswitches and electrical connectors to be able to operate the projector without having to open the box, and cut out some apertures to have access to the USB and VGAports of the laptop, to make it possible/easier to copy files, start videos, etc
Image Notes1. Ballast for the lamp2. Laptop power supply3. Power supply for the fans
Image Notes1. Computer power supply switch2. Computer power button3. Fan switch4. Lamp switch
http://www.instructables.com/id/Hacking-an-old-laptop-into-a-3D-projector/
Image Notes1. General power connector
Image Notes1. Access to USB and VGA ports of the laptop
Step 9: Taking it all apart, staining the wood, adding detailsAfter putting so much efforts in building a kickass 3D projector, it would be too bad to leave it unfinished.Take it all apart ! Use some nice wood varnish, or your favorite wood finish and make it pretty.
To decorate the air intake apertures, I cut some small wood pieces and glued them to the panel to make a nice looking ventilation grille which prevents light from comingout.I also added some hinges to be able to open the top panel more easily.
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Step 10: Putting it back together !Here you go ! A functioning 3D projector built from a hacked laptop.I know that I am missing a lot of details. However most of them are not specific to my 3D version of a DIY projector, and can be found elsewhere in the links that Iprovided.
For the 3D-related details, I'll try to add some over time and keep updating this instructable, and I'll be glad to answer any questions in the comments. In the meantime, Iwanted to put this project out there, hoping that it will be of interest to some DIYers in quest of a challenge !
Image Notes1. Some pretty hinges2. Ventilation grilles, made of small wood pieces
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Image Notes1. A fair amount of light comes out of these fan openings, luckily it's at the back ofthe box so the projected image doesn't suffer
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