DIY Video Projector

[jjasniew]

Myren,

Glad to hear you're going to seek patents on your ideas and hard work. It's worth it, for the investment you've made in all this, I'm sure.

I was wondering if you could at least share the specific model number of the Viewsonic panel you're working with? This would just save some of the others from wasting their time and money on an unknown, when you could just "get one of these" take it apart and go.

Thanks,

[Myren]

OHP:

cooling is an issue. for my original OHP based projection system, i replaced the normal fan with two ultra-quiet 120mm panaflos that put out way more CFM than stock (while still being quieter). and i have an ultra silent blower fan with jury rigged airflow device blowing a constant stream of air between the panel and the projectors surface. my panels way cooler than it needs to be (low 90's after being left on overnight in a "warm" basement), but my guess is most projectors will overheat the panels.

new projectors are probably better, using more efficient bulbs and whatnot. unfortunately the bulbs are more costly. i'm still willing to bet stock heating is insufficient.

but yeah, OHP's are a GREAT way to go. having optics where they need to be is almost sinfully nice.

btw: OHP's do have large lenses. the overheads may be only 3 inches or so, but the projection surface itself is typically a fresnel. something has to be bigger than the panel to point the light in the right direction.

myren

[Myren]

the prototype "if i put light through a panel will **** happen" system (which worked absolutely awsomely) was just a viewsonic vg150 monitor. 1024 x 768, 350:1 contrast. its what i'd be using now if the panel werent being replaced right now.

all it took was a small headed and a normal sized phillips head and two or three hours of forced patience. just go slow, dont ever use force and it'll all come apart nicely. its fairly solidly built (i wouldnt say its "tough", but i wouldnt expect it to be), decent contrast ratio. totally go for it. cant put out anything but recommendations for it. great 15" panel. if you've any questions in the disassembly thereof, please please please feel free to email me, im me, whatever. i'd love to help.

the one thing people might consider is 14 inch panels. if you can find 14 inch 1024 x 768 panels with decent contrast ratio & decent pixel ghosting, i'd go for that over the 15". some of the 15" wont be visible without a relatively costly and painfully annoying changing of the fresnel on the OHP. 14 inch would be just about perfect, i think.

by the way, before purchasing my viewsonic i called them up and talked with a technical engineer for a while, discussing how the whole thing was made. that way i had a fairly certain idea it would all work before i bought the panel itself. made sure there was no adhesive anywhere, made sure the ribon cables moved to the side, **** like that. i'd highly suggest similar phone calls if you find a panel taht interests you.

myren

[jjasniew]

I measured a 15" panel recently and got 12.125" X 9.125", it's the 12" measure that'll git ya, on an ordinary OHP.

For example, my Elmo OHP sports a 11.2 X 11.2" stage aperature. A 14" panel, as Myren suggests, will fit (provided it's the same proportions as the 15" measures above)

[Myren]

nail on the head with the 14 incher. better fit, same res. yup

really really great screen links btw. sadly there are still no substitutes for a damned good (see: costly) screen

[Fiat1]

I am sorry for holding on to this information for so long, I just could not be bothered posting it. The following link of for a theater supplier who sells all kinds of motion picture screen material cheap. It is hight gain and what not.
http://www.cinemadealer.com/cgi-bin/...y_Code=screens

I recomend the Hurley Screens, as the normal screen in only $3.40 per square foot.

[jjasniew]

Myren,

Care to share the number for Viewsonic that you got your chat about the VG150 going with?

I'm strongly considering a VP140. However, I notice they come in VP140, VP-140-3, etc and with my luck, the -3 version would be the one where you cant move the driver cards outta they way...

Need someome to talk to.

Thanks

[redryder]

I am new to the forum here and while I have read through most of this thread I have not read all 1000 posts so if I repeat something please forgive me.

I have started on my own projector using an nView Media Pro LCD (only 640x480, but its a start). For those interested you can get all sorts of things including some pretty cheap lenses at herbach.com and they are pretty high quality.

My question is has anyone taken the projector idea and tried to turn it into a projection tv, i.e. put the whole thing in a housing and use a rear projection screen instead of a front projection screen. Any info that someone has on this would be appreciated.

[dwalls32]

http://bstv.timlewellyn.com/

He is supposedly getting ready to post pics soon...

[jjasniew]

I wonder what type of screen timewellyn is using?

I posted a link (a few back) that showed the structure of a rear projection setup. Clearly, this could be adapted to an OHP situation.

I'm selling an XGA projection panel on ebay. Warning; it's pricey. Funds are needed to continue with my experimentation, which is approaching a financial runaway condition!

Check it out if you're interested. Check it out if you're not! Two things I forgot to explicitly mention, no bad pixels and yes, the images are actually from this panel.

http://cgi.ebay.com/ws/eBayISAPI.dll...ndexURL=0&rd=1