Home made projector!

[Chernobyl]

Originally Posted by gizmo

You can blow air directly on the bulb to help cool it and extend the bulb life, but you have to be very, VERY careful. Reason being, as hot as that glass envelope gets, you can create enough of a temperature differential to shatter the bulb. This means that great care must be taken in ensuring that you have even airflow across all of the bulb. As this is very hard to ensure, most of the less expensive designs don't even try.

Great stuff!
At some point I'll put a slow little fan inside the OHP in the vain hope of moving more heat from the bulb, extending bulb life.

My first bulb died after about 2 weeks of (ab)use! I did expect this, but at least we can gauge a little, how much powering up/down the bulb can affect its life. It was switched on/off 10+ times a day with many changes between low/high power. I cant say how many hours it was used, maybe 1/2 its rated life for high power?
In theory on the low power setting it will last up to 270 hrs.

For a real one shot innacurate measurement of switching vs lamp life, it will last 270hrs or around 140 switches.
This equates to around 2 hours per switch on. If you use it for less than 2 hours each time you power it up, you will lose lamp life.

Thats real rough and shoddy but I have to start somewhere

[Gizmo]

In the bad old days of computers before we had soft-start power supplies and such, I used to figure, rough and tough, that a complete cold power cycle was worth 24 hours of device life.

[Chernobyl]

haha baaad old days!

I tried the OHP screen again and wow, what a difference.
Not sure what was going on earlier, but this is so much brighter.
Cant wait to get a new big screen as this is only 5.5ft
I'm off for the new year and will be Demoing it.
I'll let you know the opinions.

Happy New Year.

[Chernobyl]

Hi guys
I've had a good break and so has the camera!
The USB lead is broken so have ordered a 20 in 1 card reader.
I'll put up a load of new piccys when it arrives

For the past week, I have demo'd and used the projector nearly 100% of the time, my monitor is off. The OHP screen (rather than the sheet) has made all the difference, it is quite an amazing display. Currently its about 5ft diagonal.
Everything is crystal clear, very bright and is much better to use than my 22" Iiyama monitor!
I was previously worried about dark movies and games, no more!! Everything is very good. A tiny amount of tweaking is done, just the same as I always did when using my CRT monitor/TV. Basically, I turn Digital Vibrance up a tad to improve colours and increase the gamma slightly on movies. Thats it.
The OHP is sat on the floor in front of the sofa, projecting the image which is central to my eye height onto the OHP screen about 6ft away from me. Absolutely perfect.


Its taken some time to work out why I had poorer results to start with. It seems that since I changed the bulb, I've only had good results. Bad bulb?
Now it runs on OHP low power mode, produces a vivid colourful picture.
Its useable in daylight for Windows use and with the curtains closed is perfect for games and movies. Its fine for Windows use with the lights on!
About 1/15th of the right of the screen is lost as the OHP isnt quite as wide as the 15" display. The only problems this gives is not being able to see your Ammo in some FPS games and the X button to close a Window isnt in view. Double clicking on the top of the window shrinks it into view, or right click, close

I cant recommend this project enough.
The demo reports are glowing, it has surprised many people including myself. The projector provided winamp visuals and music all night at the New Years party.
I'm doing another demo tomorrow.

Yet to be built:
LCD screen solid mount
Dark OHP/LCD cover with fans blowing onto the top and underneath the LCD
Extra fan inside OHP

For now I'm enjoying it. The rest of the project will be completed in the next few weeks as I decide on the best materials to use.

Go for it

PS if you havent tried the Winamp plugin 'R4' give it a go. Very impressive, especially at 5ft

[Samuknow]

About 1/15th of the right of the screen is lost as the OHP isnt quite as wide as the 15" display. The only problems this gives is not being able to see your Ammo in some FPS games and the X button to close a Window isnt in view. Double clicking on the top of the window shrinks it into view, or right click, close

Have you tried to adjust the display manually on the LCD to position it over the OHP area?

Just thought I'd try....

[Chernobyl]

The LCD is slightly wider than the OHP lit area, adjusting left or right changes which bit you dont see.
(edit: I see what you were saying. I like to keep the left side of Windows on screen as I use a left side toolbar, hence I chop the right side off)

The only ways to improve this are:
Shrinking the display so it uses less screen area. This wouldnt look good on an LCD though (Edit: not true, fixed in later post).
Get a bigger OHP
Get a 14" LCD.

I dont know if bigger OHP's exist, 14" LCD's are expensive gold dust at XGA res.
Its a tiny sacrifice for the screen you get

[Cesium]

hey, i also saw that toms hardware guide and am going to attempt it. I have a 3m 9100 projector and a cmv 15" 16ms lcd on its way (coming either tomorrow or monday)

the thing about my overhead is that it has as 10.5" x 10.5 plastic opening with rounded corners, glass panel on top of that, fresnel beneath the plastic. both fresnel and glass = about 12" so im thinking, why not just cut away the part that is blocking the extra width of the fresnel lense? im fairly certain that i could get the full width needed to see the 15" completely.
i bet that you could solve that blockage problem too if you did this

[Chernobyl]

Originally Posted by Cesium

hey, i also saw that toms hardware guide and am going to attempt it. I have a 3m 9100 projector and a cmv 15" 16ms lcd on its way (coming either tomorrow or monday)

the thing about my overhead is that it has as 10.5" x 10.5 plastic opening with rounded corners, glass panel on top of that, fresnel beneath the plastic. both fresnel and glass = about 12" so im thinking, why not just cut away the part that is blocking the extra width of the fresnel lense? im fairly certain that i could get the full width needed to see the 15" completely.
i bet that you could solve that blockage problem too if you did this

Thats an excellent idea.
I checked my OHP and the plastic edge between the Glass and the fresnel lense is shaped to stop light in/out. This would need replacing once the plastic is cut to the new shape.
Oh and voiding my warranty!
I'll see if it bugs me now

sorry I cant post pics, might be 2 weeks, ordered part from Hong Kong. Doh!

Late edit:
Real good luck with the project
Tell us how you get on. Please get a good screen, if not its like driving a porsche with bicycle wheels!

[DiabloAbogado]

Hey Cesium! Just jumping right into the forums and hoping to get front page? Good luck with the project and welcome! Also, if you're not folding, you should start. If you're not folding for AOA, you should be!

[Chernobyl]

It got the better of me!

Quick note:
The plastic shielding between the fresnel lense and OHP glass is designed to route cold air in across it into the OHP. It may have a secondary function of preventing light bleeding. One end is open to the light though.

I found an old very thin tip soldering iron. Tracing the edge of the 'light stopping plastic', I cut out the offending material. The end result was fairly straight with a large amount of melted plastic left stuck to the OHP lid.
I chiselled it off carefully with a screwdriver and filed the edges flat.
The plastic could have been cut a bit further back but I decided to keep the air routers in place rather than chopping them out. Maybe the full screen width is available if I cut further. I might find out later

If you do this, please make sure you have a convenient gale blowing to get rid of the real bad smoke which seems to know just where your nose is!
The cutting process was very slow so be prepared to be in the smoky environment for some time. Fresh airflow is essential.

The result is magic!
I get nearly all the desktop. Everything from left to right is there up to the clock on the taskbar which I cannot see. Moving it slightly for games brings the missing Ammo into view


Many thanks Cesium

Photos to come of the massacre, may take a few weeks though.
Cant get them out of my camera!

[Cesium]

alright, im glad that worked out

my lcd came today (newegg rocks) and since my friend has the dremel, i wont be cutting till tomorrow morning, but i set everything up anyways with the ohp plastic at standard. I threw everything for the ohp back together real quick and i think i may have inverted the fresnel lense since im getting a strange blur that leads to the right only (not visable when looking directly at the lcd)

yeah, as i was dismantling my lcd, i was really smart and assumed that the tft panel would be slightly stuck onto the backlight, so i kinda dropped in 5 feet in the air, hitting halfway down the corner of my desk and then onto the nice carpeting. I thought for sure i had screwed it, but i quick tested it and miraculously it survived! sure saved me a lot of potential hassle

I have to find some sort of backdrop other than my yellow paint to project onto...would a white bed sheet work?

heres some shaky digicam pics of what i have thus far

[danrok]

Maybe just paint a white rectangle on the wall with matt emulsion. That would work better than a bed sheet.

[Cesium]

theres not a chance that my parents would let me paint my wall, so i was thinking maybe a large sheet of paper would work

on a side note, heres a quick video of css my brother took of my playing
http://enward327.frozencrystal.com/i...rojectorcs.wmv

[danrok]

You could buy a sheet of 4mm thick MDF or ply wood and paint that white.

[Chernobyl]

Originally Posted by Cesium

alright, im glad that worked out

my lcd came today (newegg rocks) and since my friend has the dremel, i wont be cutting till tomorrow morning, but i set everything up anyways with the ohp plastic at standard. I threw everything for the ohp back together real quick and i think i may have inverted the fresnel lense since im getting a strange blur that leads to the right only (not visable when looking directly at the lcd)

yeah, as i was dismantling my lcd, i was really smart and assumed that the tft panel would be slightly stuck onto the backlight, so i kinda dropped in 5 feet in the air, hitting halfway down the corner of my desk and then onto the nice carpeting. I thought for sure i had screwed it, but i quick tested it and miraculously it survived! sure saved me a lot of potential hassle

I have to find some sort of backdrop other than my yellow paint to project onto...would a white bed sheet work?

heres some shaky digicam pics of what i have thus far

Hi Cesium
Making your own projector deserves its own thread!
If you can start a new thread it will help us both

I tried a bedsheet, it wasnt pretty. I spent most of my time trying to compensate for how bad it was! (and whinging - read previous posts).
If you can get a big sheet of bright white paper, it may do fine for testing. Get a decent screen as quick as you can though, it makes yer smile that much bigger If you can possibly borrow an OHP screen just to see the difference you can gauge how long you can do without one!

I read that handling the fresnel lense with fingers is a no no. Maybe as its hard/impossible to clean the ridged side? Thought you might need to know that. I used fingers very carefully to hold mine by the edge and wiped it clean after.

I'm glad your panel survived the fall. Dont they seem delicate?
Nice Video

Get Winamp and the R4 Visual plugin. I sat for hours last night, beer in hand playing tunes quite loudly and was rivetted to my seat. Awesome. It looks like you can touch the visuals, the picture is real solid.

[Cesium]

Originally Posted by Chernobyl

Hi Cesium
Making your own projector deserves its own thread!
If you can start a new thread it will help us both

well, i dont think that i'll be having too many more updates, so if i could tag along here it might make more sense than my own thread that will be dead in a few days

[Chernobyl]

Originally Posted by Cesium

well, i dont think that i'll be having too many more updates, so if i could tag along here it might make more sense than my own thread that will be dead in a few days

OK, do hang around
I note that your OHP has a cooling layer and you arent using any fans on the LCD. Have you found any overly dark spots on the image or is it fine to not have a fan blowing on the LCD?
I (and many others) would like your opinion on how bright your projector is on a good screen, please do report if you try.

While investigating resizing of the screen to fit, I came across the NVKeystone utility, provided nice and free with NVidias drivers! (part of NView)
This does a rather good job of resizing the screen with minimum reduction in quality. I managed to get the whole 1024x768 on the screen (it squashes it to the shape you make). It can also correct a screen being projected from the wrong angle/height (you do lose a bit of resolution, to be expected).
The result is very good, slightly blurry in places, not as bad as I thought.

There is one problem which I hope will be fixed: The mouse jerks like a mad thing. In gaming it ruins the experience. Movies jerk too, this suggests it isnt a direct mouse problem. CPU usage while playing the film was 17 - 24%.
Its no trouble though as most of the LCD is now on the screen, games and movies dont suffer without resizing.
The drivers in use are the Tech Connect 71.24 optimised which are beta. If you (or I) find drivers that do work better, please post

NVKeystone is fantastic for Windows use though.
I've assigned a hotkey ALT-K to switch it on and off. Immediately see the whole desktop on the screen, niiiiice. The mouse hops a little but is useable.
I checked the mouse USB refresh rate to see if it was affected and it wasnt.
Hopefully another GFX driver will work better.

Edit: your blurring problem on one side may be the screen isnt quite level with the glass. I have the same when using foam to support the display as it squashes the heavy end more.

[Cesium]

yep, the blur was fixed when i noticed that one of the top lenses wasnt quite centered.

i looked around and couldnt find anything to use that is big enough to work as a screen that wouldnt cost much... im cheap but i'll eventually get there

i used an option in the menu of the lcd which shrunk the horizontal just enough so that it fits perfect after my cutting

note that i have my ceiling fan blowing full blast until i get some more permanent type

about your mouse lag, be sure that your projector is your main monitor, that fixed it for me

http://enward327.frozencrystal.com/i...yprojector.wmv

[Gizmo]

Originally Posted by Chernobyl

OK, do hang around
While investigating resizing of the screen to fit, I came across the NVKeystone utility, provided nice and free with NVidias drivers! (part of NView)

That should also allow you to correct the geometry for the distortion caused by projecting the picture at an angle on the screen (e.g. if your projector isn't exactly centered in the screen)

[Chernobyl]

Originally Posted by Cesium

yep, the blur was fixed when i noticed that one of the top lenses wasnt quite centered.

i looked around and couldnt find anything to use that is big enough to work as a screen that wouldnt cost much... im cheap but i'll eventually get there

i used an option in the menu of the lcd which shrunk the horizontal just enough so that it fits perfect after my cutting

note that i have my ceiling fan blowing full blast until i get some more permanent type

about your mouse lag, be sure that your projector is your main monitor, that fixed it for me

http://enward327.frozencrystal.com/i...yprojector.wmv

haha, nice vid!
Have to say the result looks real good.
Search on US Ebay for words: screen material Pretty good prices!

To test the NVKeystone correction properly I installed 66.93 WHQL and then made the projector the main display and the only display. Using Keystone correction, the mouse is always laggy. Without Keystone its nice and smooth. Oh well.
Nice feature your LCD has to shrink the screen!

I've been reading about UV and IR light filters.
It appears if your light produces enough UV light, it will fade the screen colours over time to a browner shade. Not good, I need to find what the different OHP bulb characteristics are and see how bad my bulb is.
IR filters to stop heat do apparently damp the light a little too. If you can tell from looking, what is the cooling layer made from in your OHP?

Cheers