And some more......

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And one with the lights off.

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I'm looking forward to starting my 15 inch LCD projector after finishing this one.
I think that this PSOne projector is probably going to end up with my niece and nephew.

I'm going to do a couple of things with this one first. The bottom of the image looks a little dark. I'm going to have to give some thought to getting the brightness even. Having four identical bulbs in it may help. I'm going to have to go to Walmart and pick up another couple of those compact fluorescent "sunlight" bulbs. I'm going to rebuild the lightbox, too, out of a sturdier material than cardboard.

I love projector building!


Tgreenwood

Cool this is really amazing, superb, high class, congrats!!!
muuuuuaahh!! u did it tawny.
Cant believe this is using CFL and a PJ lens.
So one question i have though for you is how big is the size of the projection, i know u had mentioned it in one of the posts somewhere, but i was just being lazy. The bigger question is with the size of image that u project, do you see any pixelation at all? Reason i wonder is because with my dvd player build over OHP that i attempted to project a 48" - 70" image, i could clearly see pixelation, and i thoght it was a little higher res than the PSOne screen.

Anyways, I went to a local hardware shop here and they were carrying a 32 watt CFL for $9.00 so i bought two of those, although now with the pixelation problem i am seriously thinking of going with a higer res panel. That probably means i have to go with a 15" or higher, to be in a low price range.
Dont want to spend more than $200 in total on my build and still manage to get a decent picture.
I have to pack up the DVD player and either sell it back on ebay, or maybe i will just give it as a gift to my 6 year old. I might have botched something while stripping it though, cause it keeps making a high pitched sound whenever i power it on now. Wonder what it is though, ould it be something on the controller board making a contact somewhere it shouldnt be making?

The wifey keeps asking me wh i bother with tinkering around so much with all this stuff and why i dont just go out and buy a commercial PJ if i need one so bad, and i try to convince her that going the DIY route is much more fun.
Anyways, too long a post, good luck on your 15" inch build, i will try and build that one of these days, i just hate the size of it though, small is better for me, i am asian u see.
Cheers
-Sachin

It's a 65 inch diagonal image, and yes, it is pretty pixelated. But when I am kicked back on the sofa with my eyes about eleven feet from the screen I don't see any pixels at all. At eight feet it looks good, too. Any closer and you start to really see pixels.

The pixelation is the main reason it is going to be given to my sisters kids. I bought a 15 inch LCD TV that also has VGA input to make my main projector out of. It was good to build to prove to myself that CFLs would work in a projector.

Tgreenwood

Good to see some experimental work, nice results.
<Naysayer boots on>
I’m not sure if you are aware of this or not but I don’t think using the small form fluorescent lamps for a larger LCD will have the same performance that you have witnessed using the small LCD. Unless you can find a triplet that has the same LCD to Lens diameter ratio as your smaller projector. By all means try it, just don’t put all your eggs in the one basket.
<Naysayer boots off>

Just ignore my last comment if you already know this.

DJ

Edit:
I can elaborate a bit more if you would like.

I would be fascinated to see the attempt at a 15" version.

I would also be curious to see an up close picture of the grid from pgen.exe, so the effect of a non-point light source can be seen.

I wouldn't worry too much about any screen door effect your getting. Seems like there are a lot of ways around that if it bugs you. (translucent screen, distance to lens adjustment, some kind of filter prior to the projections lens, etc).

Have you had any success with adjusting your digital camera to better represent the color and brightness of your image?

Good luck!

Nice to see the new bulb work OK.

Do you have any way to adjust the colors, the green level looks a litle high.

How far away is the PJ from the screen?

How do you rate the brightness. Can you see the screen with any light in the room?

I'm willing to give it a shot.

The bulbs I'm going to be using in the 15 inch will be 55 watt and/or 65 watt CFLs with good CRI and color temp. The 15 incher lightbox will also have between two to three times the number of lumens as the PSOne lightbox, hopefully to make up for the inherent inefficiencies of more diffuse light coming from the LCD to the projection lens.

Wish me luck!

"pgen.exe" ?



I'm using the "fireworks" setting on my camera, so it is a "reasonable" representation of the color and brightness, but brighter would be closer to real life.

No color adjustments available on the PSOne LCD that I know of. The image colors are a function of the Fluorescent lamps used, they output light in three or four pretty narrow bands, usually. Looks like the green band is a little stronger than the rest.

68 inches. The image is 65 inch diagonal, so it is about a 1:1 ratio.



Definitely. Here are a couple of pictures. (It is a bit@h taking pictures with this camera. I'm still on a learning curve.)


This one is with the brightness turned all the way down on the LCD using the LCD buttons.(Color is better)
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This one is with the brightness turned all the way up on the LCD using the LCD buttons. Colors washed out some, but you can definitely see it.
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Tgreenwood

Ey mate, looks really good. I am considering an array of 16 or 25 of these on a 17" screen, and I was wondering about how even the brightness is.

Would you mind posting up a picture of a black white screen (if possible, or at least a solid colour) to show the evenness.

Any thoughts to taking your 4 bulb sockets and tying them all into one plug? Is there any reason for the fan, does the LCD get that hot with the lightbox sitting on it for a period of time?

You guys need to keep in mind that the only reason this setup works is that the triplet is the same size as the LCD. If the triplet is smaller than the LCD the lamp will need to be smaler too.

The pro lens or standard triplet is 5x smaller than the LCD.

So two questions,
If the LCD size is bigger than the triplet, then what can be done ?
arizonavideo you mentioned the lamp will need to be smaller, does that mean we would need a fresnel between the lamp and the LCD to cover the whole lcd?
Would it be possible to explain why and how this would or would not work with a picture of some sort?
Also a quick question to tgreenwood, how hot does it get near the lcd with ur current setup, i guess someone asked a question a fwe posts above, but nonetheless i am asking it again, meaning is there really a need for a fan?
Thx in advance

I might tie all four bulb sockets into one plug, but I haven't bothered yet.

I figure with the bulbs enclosed, some heat will build up. It would probably take 20 or 30 minutes for enough heat to build up to make the LCD develop a black spot, so I used a fan. Fluorescents are cooler, but they do produce some heat.

Thanks, I was trying to figure out how to shrink down all the power needs down to one cord, especially since there are 2 DC units, and 4 light sources. I guess if you could get all 4 spliced into one AC cord, you could get one of the mini-strips and mount inside the unit, then only have the mini-powerstrip cord coming out of the final box. I am just trying to figure out how to create a clean setup if I try this, especially safe considering it would be for my kids, and don't need to come home one afternoon to find my kids hauled off in an ambulance or my house a pile of carbon.

Update:

I tried my PSOne projector with a smaller lens (2 1/2 inch diameter) and the lighting in the projection was very uneven. It was darker in a "+" shape with the four corners brighter and the entire image a lot dimmer overall. You could definitely tell that there were four light bulbs in the box and what positions they were in. I fixed it by putting one of the light diffusion sheets from the original backlight assembly on the LCD (I'm glad I kept everything). It diffused the light beautifully, but it cut down on projector brightness by about 20% to my eyes. Possibly leaving the anti-glare on would do the same to make the lighting more even. With the smaller lens it ended up not being watchable.

Another thing that I will definitely be doing on my 15 inch projector is aligning the bulbs parallel to the LCD and covering as much of the surface as possible to make the light even without having to use a diffuser. I hope it works. This is uncharted territory.

I think that a lot of the problem has to do with the efficiency of the lens; the amount of light that it will let through, called an F-number of F-stop. The TV Projection lens is a "fast" lens - F1.3 . The small diameter lens I used is about an F2.8. The smaller the F number of a lens, the brighter the image it projects. Since an F2.8 lens only lets through 1/4 of the light that a F1.4 lets through, the uneveness of the light is much more visible. Only the strongest light gets through. What a PITA.

I'll let you know of any more developments.


Tgreenwood

TGreenwood,
Does it mean you would have to use a bigger lens for the 15 inch build?
or are you planning to go with a std 15 inch lumenlab build and just use the CFL instead of the HID bulbs?
Just want to know what you plan on doing, one of these days when i get some time, i am gonna get those CFL lamps and try it on my 7 inch DVD player, unfortunately work is too consuming right now and I cant get anything else done.
Cheers
-Sachin

I'm still definitely going with the large CFL bulbs with a reflective lightbox on my 15 inch build. The heat produced by the HID bulbs is just too much for me.

I bought a LL varifocal projection lens for my 15 incher. I don't know yet what the F-number is on that lens, so I am going to put a bunch of 55 and/or 65 watt CFLs in the lightbox.

Tgreenwood

how is the heat with the cfls? low med high?

Very low. The lightbox doesn't even get warm (with the fan running of course).

Tgreenwood

Great job

With a da-lite screen or some good paint and I think you wont ned to do anything else.
Maybe a new box? just for looks of course but again great job just like those that said led's wouldn't work well you just proved that fluorescent's can aswell. keep it up!

have you thought of setting the bulb up in a more standard set up(paralel to the lcd) with a "bowl" reflector like in most larger pj's?

It might be something for me to try in another build.

Tgreenwood

What would be the difference between mylar and aluminum foil? I would think that mylar is more reflective, but how much?

The mylar I got is 98% reflective according to the manufacturer. That's as good as a first surface mirror. I can't imagine that aluminum foil could be anywhere close.

Tgreenwood

So, a big difference in screen brightness in other words. I'll just use the aluminum foil to make a mock-up while waiting for my mylar to come in (grrr...I've been wanting to see an image out of this thing for quite some time now....)

so what are the final or current settings for the lamps you have in the pictures? wattage/light output?

-edit- i just went to walmart, kmart, and target. Seems popular lights are (100w) that use 24-27 actual watts and put out between 1600-1800 lumens, spectrums were usable around 5k, and 3 packs were about $7.50ish. I was just price shopping for now but it got me thinking, doesnt ikea also have cfls?

I hereby declare this to be the last revision of the PSOne/fluorescent bulb/TV lens projector.

I wanted to make it really easy to get parts to build this (as much as I could) so I decided to get widely available bulbs. I got these at Walmart.
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These are GE daylight 100 compact fluorescent bulbs.
8000 hour life
6500K color temp
26 watts
1600 lumens (about 60 lumens per watt, not bad)

Durned if I can remember how much they cost, I think between $5 to $7 for the two-pack. I bought three two-packs.

Since these bulbs are a lot shorter than the other ones, I built a new lightbox with the bulb mounting area curved to automatically keep the bulbs from touching the inside of the lightbox. Five bulbs fit about right.
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Here are the five bulbs in the lightbox. This lightbox is approx 2 1/2 inches shorter than the previous one. I got really sloppy building this lightbox, so the opening is quite a bit bigger than the LCD dimensions. I didn't bother measuring anything, and it shows.


In an attempt to recycle some of the light that was hitting around the LCD, I slapped some mylar around the LCD to reflect it back into the lightbox.
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I left the diffusing sheet on the LCD thinking it would help to even out the light. I think it did help, but getting my weirdly shaped lightbox lined up evenly with the LCD was a bit of a challenge, especially since I went for mounting the fan on the side. I ended up not getting even lighting, but that would be fixed if I built the lightbox right.

Here's my monstrosity all put back together.
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The only thing I really like about this new arrangement is the PowerSquid power strip. I like not having to shuffle plugs around to make room for the wall-warts, and the built in on-off switch works smoothly. The PowerSquid has five receptacles, so I wired three of the bulbs together on one plug, and the two other bulbs onto another plug.

Here's a better view of the projector. Its dimensions are 8 inches high, 8 inches wide and 18 inches long.
The five lightbox bulbs produce a total of 8000 lumens using 130 watts.
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Here are the results of these bulbs. The color reproduction looks really good. I think with getting a half-decent screen (this was projected on a textured wall) and turning dowm the brightness on the LCD a little bit would give a really nice result.

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Incredibles

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"Cars" preview

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Mommas house preview


Tgreenwood

If you want to make larger pictures you can resize them to 640x480 and then adjust this jpeg compression to make the pictures about 30k so you can post three per post.

It looks like the new lamps are working OK. You now have blue. How is the brightness? Can you do a shot in the dark?

Here are some screenshots taken in the dark.
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A couple more..
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There is one thing I noticed with this last revision build.
With the lightbulbs this close to the LCD, slight hotspotting is more noticable. Also, the lightbulbs being closer appears to cause the image to be more washed out. I can see the difference. There aren't any more or less lumens in the lightbox really, and I think that the projected image had better contrast and was the same brightness with the bulbs further away.

Turning off the two bottom bulbs in the lightbox improves the appearance ot the top "black bar" in the image, looks a lot more black instead of the gray in the photos posted, but the rest of the image looks almost as bright.

Tgreenwood

Here are a couple of pictures to describe what I am talking about.

First is with the bottom bulbs on. Second is with bottom bulbs off.
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Another reason this may be happening is the curvature of the rear of the lightbox. It may be directing the light in unexpected ways.

Tgreenwood

It's hard to say from a photo..but it seems brightness is OK

I guess are you happy with it is the biggest test

Why mylar?


When I was figuring out how to use CFLs in a projector I discovered that when using a recommended LL MH lamp that produces 40,000 lumens only about 8% of the light from the lamp actually made it to the LCD even when using a kick-a$$ reflector. I thought that was ridiculously inefficient. Bigger reflectors produced a problem with concentrating too much heat on the LCD along with the light, and good big reflectors were expensive and difficult to find.

In a standard build MH lamp, 8% of 40,000 lumens is 3200 lumens at the LCD. I started with four compact fluorescent bulbs that totaled 8800 lumens altogether. If I could get half of that light to the LCD, I had a good chance of making it work. To get most of the light to the LCD, I couldn't let any of that light escape, so total internal reflection was it.

So, my goal was to get as close to 100% of the light from CFLs to the LCD as I could manage. I thought about using a reflector box made out of first-surface mirrors, but that got too expensive real quick. Then I went to home depot and bought a box of mirror tiles. Since they are made of glass mirror they were difficult to work with and I managed to get plenty of small cuts on my fingers. Definitely a no-go. My next try was acrylic mirror. Nice and light, relatively easy to cut and cheap. It worked really well, but I just didn't have the patience at the time to work with it. I personally don't have the upper body strength to do the score and snap method of cutting the acrylic mirrors to the size I wanted. I tried using my little battery powered saw but couldn't get a straight cut to save my life. I am the worst carpenter I have ever seen. So, acrylic mirror went into reserve for a later time. I still have a couple of sheets of it and may end up using it later after I develop a knack for cutting the stuff.

OK, I needed super reflectivity that was easy to work with. I stumbled across the idea of using aluminized mylar while looking for full-spectrum compact fluorescent lamps on Ebay. One of the Ebay sellers of the CFLs I thought might work had an Ebay store that also had listed aluminized mylar. Well hey, I thought, this looks really good. This mylar is 98% reflective; about as good as any first-surface mirror that I could find. Easy to handle, cuts with scissors, YES!

Since CFLs produce relatively few lumens compared with standard build MH lamps, I think that a reflective lightbox is absolutely necessary to get enough lumens to the LCD. What kind of reflective material is up to you.

Tgreenwood

That's really informative! I might have to try acrylic mirror. Where did you say you got that?

By the way, if you're having trouble snapping plastic/acrylic/Plexiglas, you didn't score the sheet enough. You have to apply a LOT of pressure with a sharp Xacto blade or new utility knife for the scoring and snapping to be effective. Otherwise, the stuff's practically bulletproof (with many variations that are). Metal rulers are a must as you will just slice off pieces of wood or plastic rulers. Clamping down the metal ruler and sheet of plastic/acrylic/Plexiglas helps quite a bit.

Acrylic Mirror Sheeting at US Plastic link. I bought the 1/8th inch thick sheet.


Like I said, upper body strength. I scored that stuff like crazy, but apparently couldn't put enough pressure onto it to do it right. Maybe I can rig some kind of handle for the scoring tool so I can put some leverage into it. Thank goodness the mylar works well.

Tgreenwood

Well, you could try using a glass cutter. They're only a few dollars at a hardware store, and I would think that since it can score glass, it should have no trouble scoring acrylic. The diamond-wheel blade is REALLY sharp. Or you could try a hacksaw. A little bit rougher, but it's easier.

You've inspired me, tgreenwood.

I am just finishing up my 15" PJ, so it's about time for the next project - so I am going to try a small PJ similar to yours.

I ordered the ADVX D1420 4.2" portable dvd player, and the same lens you used. I'll have to start a plog once I get started....

Anyway - thanks for all the interesting info in this thread, keep up the experimenting !

Why do these fluorescents seem to work so well?

I was reading through this post Rgb Leds As A Light Source? A Spectrum Advantage?!? and it occurred to me that the reason that the fluorescent lamps were working so well is because the phosphors used in the fluorescent bulb were producing light in fairly narrow bands that match up to the RGB filters in the LCD.

I went in search of some spectrum graphs to see if this was true.

For a starting point, I found this metal halide spectrum on this thread : 4000k or 5200k?, Which to choose?

Here's another one
I don't know which one is more typical of the Metal Halide lamps usually used in LL projectors.

Then I found a graph of the wavelengths that pixel filters let through in this thread : Why Colour Matters, Temperature and spectrum response


Looking at these two graphs, it strikes me that a lot of light is blocked by the pixel filters when a metal halide lamp is used. The light that doesn't pass through the filters gets converted to heat at the LCD.

Here's the spectrum of a 5000k fluorescent bulb:

Spectrometer plot of a Philips 5000°K 13W CFL

The spectrum of light emitted from this fluorescent bulb matches up pretty nicely with the pixel filters. It looks like an almost ideal light source for use with LCD RGB pixel filters.

Fluorescent bulbs do produce diffuse light, true, but apparently enough of the correct wavelength light makes it through the 7 degree aperture of the pixels to produce a good projected image.

Tgreenwood

I’m not sure I understand where you got the 7° pixel aperture from.

DJ

From......
from Same idea, New Approach Post 5

and

from Multiple Light Source Theory Post 24

Come to think of it, I don't know if it is true or not. Maybe the 7 degrees is an "ideal".
Considering the wide viewing angles of LCDs now, I bet light from fairly extreme angles make it through the pixels.

It makes me question a lot of things.

Tgreenwood

The 7° light angle is probably the most misunderstood concept on the forum. It actually refers to the maximum angle away from perpendicular in a standard 15" split projector that light can exit the LCD and still be directed to the projection lens by the field fresnel. This is only an approximate and will change with focus distance.

The first example you quoted is a classic example of how this is being misunderstood. Polarizers can pass light at almost any angle. The second example is someone pointing out that the brightness enhancing film in question needs to produce light collimated within a much tighter angle to allow the field fresnel to direct it toward the triplet.

Your projector does not suffer from this limitation because your lens is large relative to your panel size and much closer to the panel. Light can leave the LCD at a rather extreme angle and still be projected. This is why your diffuse light engine works at all. With a diffuse light source on a standard build, most of the light just hits the front wall of the enclosure because the lens is small and distant. If we could find a nice cheap 15" diameter color-corrected projection lens, everyone could use flourescents and it would work great. Too bad that lens would be horribly expensive.

Thanks for clearing this up for me. It has been a point of confusion, and I made some incorrect assumptions.

Tgreenwood

What do you guys think about this screen?

http://www.amazon.com/Axion-AXN-6050-Porta...t/dp/B000H94EW4

Some guy is selling this locally, and I'm thinking about making a small PJ with screen.

I'm also planning to use the same lens that tgreenwood is using with his psone design. and with this design would it be necessary to use fresnels as collector/collimators?

That DVD player has about the same resolution as a PSOne screen, and it will accept AV input, so it looks pretty good.

If you are going to make your projector with the lightbox/fluorescent bulb/TV projection lens design, you won't need any fresnels.

Tgreenwood

I just bought this one on ebay


Descriptions LG Phillips 6.4" TFT LCD Car Monitor display LP064V1
NEW in Bulk Box I had 20 pieces New in a bulk box
click this link for more info: http://epu.ref.nstu.ru/files/downloads/sof...LP064V1.asp.htm
Manufacturer LG Philips
Part Number LP064V1-300P
Screen Size 6.40
Panel Type TFT
Resolution 640X480
Brightness 300

Components LP064V1 6,4" TFT Display

Inverter CXA-L0505
ISA bus controller Vampower 5
AGP bus controller Vampower 8
PCI bus controller Vampower 8
VGA / RGB Rainbow II
Single board computer Advantech/Aaeon
Video interface controller set EPAP-200
Interface LVDS IF151
Interface FFC digital IF107
LVDS transmitter on Advantech/Aaeon IF166
Digital transmitter on Advantech/Aaeon IF144





All good condition new sealed plastic still on screen came new in box

I'm not sure it will work but at this price I could not pass it up $35.00

here is the link http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...p;rd=1&rd=1



I am going to try to make one of these ccfl PJ I ordered a delta from ss.

wow that looks like a steal !