Home made projector!

[Chernobyl]

OHP Projector
I wish that was possible for the OHP project.
No part in itself is perfect as everything needs some work doing to allow it to be used for the projector.
Even though I have a very good result, there are still areas that can be improved.
ie
Image sticking - needs better cooling
Finding ways to lock everything in position - when using a split lense fresnel they must be aligned more accurately and you dont want anything to move once setup!
Ideal placement of the glass/fresnel split lenses - liberate the most light while not affecting the cooling.

The range of parts available is astounding too and the construction of each varies so much that its impossible to predict how much work will be required given the other parts you wish to use too.
I have had a good result from the parts I purchased but quite a few mods have been necessary. I dont have much clue if there are other parts more suited to the task.
I know for certain there are parts which are harder to work with than mine so am building the foundations of the guide on that, sticking to the fundamental points of what you need to achieve.

My plan is to finish the guide to building a OHP home made projector before Christmas which explains a lot of the pitfalls you are likely to encounter, what to look for in the parts you are purchasing and some good suggestions on how to get the best out of what you have.


HD Projector
I am choosing the parts for this with a tremendous amount of care so a recommended parts list will be possible.
Initially I will place the new LCD/controller on the same OHP I am using right now to verify it functions well, then will build a decent projector box for it to go in.
I feel this is what you are after but cannot advise yet as there is a way to go.

It has been more than difficult to find good spec parts and communicate with the suppliers/manufacturers. This is a real stumbling block and sometimes I need to spend time away from the project through exasperation.
I am hopeful that the UK supplier of the new controller will come through but I didnt get an email reply so am a little pessimistic.
However I wont give up until I have produced a good HD projector that can be built for a worthy price!
My hope is to have this completed by Christmas too but it could well take longer at the current rate of progress.

[Ominous]

Hi,
I sow that Tom’s Hardware video of LCD projector more than a half year ago.
Just a few days ago I have found a new halogen lamp: Philips - Plusline Pro 500W R7S 230v 9900lm Tungsten Halogen Lamp. Lamp life is 2000 hours, 117.6mm long, with UV block. It is typically used in Halogen floodlighting, outdoor billboards, car parks, security lighting and construction sites etc…

My question is will this lamp do the job? It’s not that much bright (9900lm), but I sow a post here that someone used a 2800lm bulb. Marks on box doesn’t says how hot this thing goes, but I think I’ll have some trouble cooling it

I’ll have money for LCD in few weeks and I was planning to buy some 15” with under 16ms response, but for now I was interested will that bulb do the job.

PS Gr8 job back there Chernobyl

[Chernobyl]

Cheers Ominous, welcome to the project

Sadly all tungsten lamps lack a lot of the blue colour spectrum.
You will get a nice picture but many blues will look grey and white will be yellowish. It will run very hot too as tungsten lamps arent very efficient.

9,900 lumens isnt a lot, the original 400W bulb I had was around 13,000 lumens.
The 250W metal halide bulb I'm now using is around 21,000 lumens.

You can get the same 250W or 400W Metal halide bulb kit with all the necessary parts delivered for less than £80 !
http://62.75.177.102/gadaffy-h5-Lich...52873903db57e9
He has the 250W kit in stock but not the 400W.
This guy sells out real fast so snap it up while you can.
I havent found anywhere in the UK that sells for near this price.

If you get a 400W, it may not have UV stop. You can check with the shop owner:
Roland Stange [roll@diy-community.de]

I now believe that the condensor lense and OHP glass are enough to stop the UV but this is an untested theory.
My issues with image sticking seem to be purely heat related not UV based as previously thought.

The condensor lense sits just above the bulb.
If you buy an OHP try to get one with a condensor lense. If not, you can get one here for less than 9 Euros, it helps keep uniform brightness especially in the corners and directs more light to the LCD.
http://62.75.177.102/gadaffy-s10h4-Kondensorlinse.html
He also has splittable fresnels etc etc if you need other bits.
Nearly forgot, he sells a good rear reflector for the 250/400W MH bulb
http://62.75.177.102/gadaffy-s12h4-R...nd_Spiege.html

When buying a faster LCD than 16ms, be sure that it supports 24 bit colour not 18 bit - 8 bit not 6 bit (for each colour).
Some LCDs trade the number of colours to allow for faster switching.

Try to get one that has already been used successfully in a projector as some LCDs have side ribbon cables that arent very long and dont allow the electronics to separate far enough from the display panel.
The ribbon(s) can be replaced but it may be difficult as the ribbons could be non standard sizes as one of our fellow Projector builders found.

Keep us up to date and good luck

ps the 2800 lumen bulb you referred to was the actual light output from his OHP. The bulb would have been somewhere around 8,000 lumens.
He mentioned that he wished it was brighter.
My 400W bulb made my OHP give out a little over 4,000 lumens.
4,000 lumens is widely regarded as the minimum you need for an acceptable result from an OHP.

[ibanBCN86]

hello! I'm Iban, maube you remember me from previous posts, the thing is that I've finished my OHP+TFT two days ago. I've used a 250W single lense OHP and a IIyama TFT, the results are quite good taking into account that the bulb has a color temperature a bit low for projecting color pictures, maybe I'll change to a hqi when possible ($$).

My question is: I have placed two fans that blow air ONLY between the TFT and the OHP, is it necessary also to cool the top surface of the TFT? or is it enought by blowing air between the OHP and the TFT as I'm doing now?

Can I place directly the TFT over the OHP or it would be too hot? I ask that because maybe achieve more focused images.

Thank u!!

Iban

[Chernobyl]

Hi Iban
The fan system you have used is a good method.
Whether its good enough is for you to decide.
If you get image sticking - an image that has been on the screen a long time appears to leave a ghost image - then you have a choice of what to do:

1) improve the cooling by removing more heat from the LCD or make sure the heat doesnt get to the LCD.
2) moderate your usage by making sure that static images arent displayed for too long. This is hard to do as it will limit your experience.

If you dont get image sticking its likely you have done enough.


The method I am using at the moment isnt bad but isnt perfect. Its simply for ease of setup but you might want to try it.
Its certainly good enough for my setup
Results will vary.

1) The OHP glass has been removed and placed inside the OHP in place of the fresnel lense. This is to maintain UV protection and stop heat gathered by the glass transferring to the LCD.
2) The fresnel has been split, the bottom half placed directly on top of the OHP over the hole where the glass was.
3) The LCD is placed directly on top of the bottom fresnel (ie both are sat on top of the OHP)
4) The top half of the fresnel is placed over the top of the LCD and can be angled to give keystone correction. This allows you to place the projector on or near the floor while having quite a tall or high screen.
It does blur the image a little as only one part of the image is in true focus but its certainly good enough for an XGA projector.

You dont need to split the fresnel, you could just sit the LCD on top of the complete fresnel. Splitting the fresnel gives a more focussed and brighter image, especially in the corners.
Sitting the LCD directly on the fresnel may introduce fresnel rings into the image. If its too bad, you cant use this method, I'm lucky its hardly noticable.
ideally you need some distance between the bottom fresnel and the LCD, try it and see.

I have tried placing the LCD directly on top of the OHP with the glass in place and it works great. The only side effect is excess heat which you may be able to remove.
By placing the glass inside the OHP, I have eliminated the heat transferring from the glass to the LCD and it has helped.

Seeing as you have a unit to blow air under the LCD, your setup might work really well with the fresnel placed directly on the OHP glass with your cooling and LCD on top. This will hopefully prevent any fresnel rings from appearing on your image.
The only issue is that the light source is now further away from the fresnel and may need moving closer. Hopefully your OHP allows you to adjust this.

[spanielgita]

hey chernobyl,

long time no speak, we still havent managed to get the internet in our new flat yet. tottaly sucks. anyways - i have all the new parts for the projector now but i cant seem to get enough light outta the bulb, i think its the fact that it isnt in the focal point of the reflector so all the light isnt being reflected back up. the bulb is huge and i will prob have to find a large reflector and cut into it to reach the focal point.

i was wondering if the ballast i have for this metal halide would be suitable for the bulb type you are using? i think that is the hqi-ts?
i dont really want to buy the new bulb and find out it wont work with my current ballast

hows your porjecting life going?

regards Dan

[Daniel ~]

Glad your getting settled in. Look forward to your further exploits!

[Chernobyl]

Heya Dan
Sorry to hear about your internet and lack of light power!
Can I ask what reflector you have used?

Just in case the problem isnt (largely) the rear reflector and is the distance of the fresnel from the bulb/condensor lense causing most of your light issues, try this:
Take the fresnel lense out of the OHP and stick it on top of the glass with the LCD on top of it.
You can then raise the whole LCD assembly with fresnel lense up and down to find the optimal distance.
Its very likely the fresnel is way too close to your larger bulb/condensor lense now which will definitely lose light.
If it seems to get brighter the lower you place the LCD, try raising the bulb/condensor lense a little to get the last few %
of light.


I tried the Ikea "Napkin ring" reflector for larger bulbs a while back which was pretty good, about 85% as bright as my reflector.
Because I can put my bulb closer to the reflector, the smaller reflector suits my setup better (and it is more reflective).
The Napkin ring may be worth a go for you as they cost only a few £


Using your Ballast on a HQI-TS bulb might work but its likely to change the colour output of the bulb at the very least.
When I first looked up your bulb, I found this snippet:
* Can be run on HPI-gear as well as on SON-gear ("Plus"-concept). The results in both light output and colour temperature are different"
They dont refer to the use of HQI gear but a ballast is a transformer, they vary in voltage out and max current flow so its possible your ballast could be used but I dont recommend it.

The danger is that if too high a voltage is fed to the bulb, it will shorten its life and can dramatically increase the chance of catastrophic failure (explosion!).
From what I have read, a 20% increase in voltage will give you only 10% of the rated bulb life and a large increase in UV output!!
Thats assuming it doesnt go bang
You will also need a new bulb, fittings and probably the starter too.
(if you didnt get a good smaller reflector you will want one of those)

Its not worth the risk of damaging your equipment and yourself by trying parts out so my advice is to get the complete light kit as its pretty cheap from your favourite supplier
Around £70 delivered I seem to remember.


My projector is wicked, thanks for asking, I'm still blown away by it!
It is unbelievable you can get something this good, this big for so little.

I downloaded the first 2 episodes of a new series called Heroes in 1080i mpeg2. The quality is stunning! It damn well should be though, the first episode was 5.3GB!!!
Playing it back looks better than any 720p I have seen, even on my limited XGA resolution so I'm looking forward to seeing it in full glory when I get all the HD kit together.

The move towards HD (1080p) is happening very slowly, I have no progress to report right now as not much has happened/progressed but I will post info as soon as I can.

Good luck with sorting the light and internet out

[gray_scoob_punk]

Thought you guys might be interested in this"

October 17, 2006

by: Jonathan Thornburg

Sanyo-Epson announce the worlds smallest 1080p LCD.

Starting tomorrow at the FPD International in Japan, Sanyo-Epson will be showcasing the worlds smallest 1080p LCD.

The unnamed set is a low temperature polysilicon (LTPS) TFT LCD. It has 1920*1080 resolution with a viewing area of 7.1”. The set also features a 180 degree viewing area with a ppi of 310.

While very little info has been released, Sanyo-Epson has stated that it is part of the companies “anytime and anywhere” strategy to become the worlds number one medium sized LCD manufacturer. Sanyo-Epson is promoting the panel for a multitude of mobile television uses such as in cars, planes, or even on your person.

We will have more information as it becomes available.

[gray_scoob_punk]

Ok, more information:

Sanyo Epson 7.1 inch polysilicon LCD display : Sanyo Epson announced the development of the world's smallest direct-view full high definition low-temperature polysilicon liquid-crystal display (LCD). Measuring just 7.1 inches, this display brings unparalleled resolution and definition to the market. The fusion of telecommunications and broadcasting through digitization and the seamless integration of cable and mobile communication in the network society have raised expectations for the next generation of mobile devices and for the improved convenience that these devices will bring. Moreover, consumers are increasingly demanding that small and medium-sized LCDs for mobile devices should have high resolution.

Sanyo Epson LCD monitor - High quality
To meet these demands, Sanyo Epson has developed products based on the concept of supplying clear, user-friendly displays that can be used anytime, anywhere. As part of its HCL-S strategy (High quality, Compact design, Low power consumption, System solutions), Sanyo Epson has developed a 7.1-inch LTPS LCD that allows full HD video and still images to be displayed on portable devices. This display is ideally placed to tap into the multimedia market as it expands further through high definition video content services, such as terrestrial digital television broadcasting and "One Seg," a new service in Japan enabling digital TV broadcasts to be viewed on mobile phones.

Sanyo Epson LTPS LCD monitor - High resolution
The 7.1-inch LTPS LCD boasts the world's smallest screen size for a full HD LCD. A resolution of 310 pixels per inch, the highest level for panels of this size, has been attained thanks to high-resolution technology and the color conversion algorithms of Sanyo Epson's Photo Fine Chromarich wide color gamut technology, which enables more than 100% coverage of the NTSC color gamut. In addition, this new display is ideal for visual expression thanks to Sanyo Epson's proprietary technologies, including Photo Fine Vistarich wide viewing angle technology, which enables the displays to produce clear images from any angle, and AME (Auto-Movie-Enhancement) image processing technology. Moreover, the display features a low-energy design, making it perfect for mobile devices.

FPD International 2006 - Sanyo Epson 7.1 inch LCD monitor
Sanyo Epson will exhibit the 7.1-inch LTPS LCD at FPD International 2006 organized by Nikkei Business Publications, which will be held from October 18 to 20 at Pacifico Yokohama. As a core company in achieving the i3 (developments in mobile displays) strategy of the Epson Group's SE07 medium-to-long-term corporate vision, Sanyo Epson will continue to develop clear, high-resolution displays that can be used anytime, anywhere, based on the concepts of the HCL-S strategy, as it strives to be the number one manufacturer of small and medium-sized LCDs.

Sanyo Epson 7.1 inch polysilicon LCD monitor - Specifications • Screen size: 18.0 cm / 7.1 inch
• Pixels: 1920 x 1080 (full high definition)
• Type: Low-temperature polysilicon TFT
• Viewing angle: 180 degrees (100:1)
• NTSC ratio: More than 100%
• Display mode: Photo Fine Vistarich, transmissive
• Pixel pitch: 310 ppi
• Other features: DualLink compatible

About Epson
Epson is a global leader in imaging products including printers, 3LCD projectors and small- and medium-sized LCDs. With an innovative and creative culture, Epson is dedicated to exceeding the vision and expectations of customers worldwide with products known for their superior quality, functionality, compactness and energy efficiency.

[ChurchSubgenius]

If they can go into full production on those and others follow suit, it will revolutionize the DIY projector scene....assuming they don't cost more than a kidney.

On a more primitive note I decided to build my SVGA OHP projector into a box, I couldn't stand the ugly ghetto look any more. I took an hour or so to completely dismantle the OHP last night and was pleasantly suprised to find out how many pieces I could re-use.
I plan on using the MKIII upright design from the now defunkt DIY Projector Co. (bought out by LumenLab, I tried posting the link but AOA won't let me)
I am running to Home Depot today at lunch and having them cut all the panels so I can do the finsh work tonight with my skil saw.

[gray_scoob_punk]

you could make a small projector that is no bigger than the projectors produced on the market.

I haven't actually make a projector yet, put it seems that if you remove the mirror on the top of the OHP and then lay the OHP on it's side it'd look more like a projector. You could then cut a hole in the bottom and mount a fan there. It'd look more like a Theatre project, but what do I know; I still haven't gotten ahold of the materials to make one yet.

[ChurchSubgenius]

You could do that as long as all your components were tied down securely but my biggest reasons for doing this are:

1. it is currently a really fragile, ugly setup with no "style"
2. I have no way of increasing my lumens (without a major lamp retro-fit)
3. I want to take the box camping with us (that's not camping!)

[gray_scoob_punk]

that would be nice; you could project it onto the side of the tent.

[ChurchSubgenius]

Originally Posted by gray_scoob_punk

that would be nice; you could project it onto the side of the tent.

lol, here is my tent.

[Chernobyl]

Hi everyone, thanks for keeping the thread going, sorry to be away so long.

Thanks lots for the information and links on the new panel
That looks just the ticket! I wonder what the street price will be?
I recently discovered another type of bulb that is lower power and runs cooler so might be ideal to partner with that panel!
I've just bought one of these bulbs which I'll go into after this...

1080p Projector
A quick mention on the progress of the 1080p Home made projector.
It has proved hard to work with the LCD controller company and LCD manufacturer between them. One wants specs for the panel and the other wont give them as the panel I want to use isnt mainstream now!
A bizarre situation as you should be able to get datasheets on any part?!

Things look good with the controller manufacturer though so not all the time was wasted.
I'm leaving getting the LCD for the 1080p projector this year and will resume early next year. Hopefully the choice of viable LCDs will improve by then <prays>


Apologies in advance for the lack of pictures, my camera isnt up to the job of capturing the projected image.
If you want to see the new bulb working inside the OHP, lemme know, its good enough for that.


New Bulb trial
Onto the new bulb!
Today a small, heavy parcel came with a new bulb (and its electronics) to try.
Its the Osram HCI-T NDL 150W bulb with single ended socket.
I got the full kit for £50 delivered! :
http://62.75.177.102/gadaffy-p75h5s2...150W_Set_.html
This bulb is a lower power smaller ceramic core which has a number of benefits which I'll go through

The ceramic core gives a very flat colour spectrum with very low peaks/higher average light power.
This means the measured light power doesnt centre around the power of the peaks and is closer to the average light power across the whole light spectrum.
From what I have read, it should look quite a bit brighter than a 150W metal halide and be about as good as a 250W metal halide!

For comparison the 250W metal halide bulbs are measured to give 21,000 lumens and the 150W ceramic gives only 12,000 lumens.
Reports have shown that this difference is made up for by its interesting characteristics.

Mounting
The bulb is single ended so only has one light socket which is easier to manage inside the OHP.
To mount it, I screwed a metal L bracket to the light chassis in the OHP and mounted the Bulb over the top of the reflector.
To get optimal distance from the reflector the reflection of the bulb was made exactly the same size as the bulb.

Quality
The bulb core is much smaller than the 250W metal halide. It gives more of a point light source which has increased sharpness.
As the LCD is sat on the lower fresnel, fresnel rings show up a little clearer. Its still fine for viewing 4 metres away though.
(The new projector will have the rear fresnel mounted further away to prevent this)
Noise shows up more so bad quality analogue TV signal does look noisier.
However nothing else has noise and simply looks higher definition

The bulbs colour is centred around 4200K (vs my MH 250W bulbs 5200K), more towards the red spectrum and away from blue.
In use, some reds really glow, blue seems to look much the same as it did.
Overall reds do look nicer, dark images are clearer, whites are a very tiny bit creamy and it looks a bit less bright.
Brightness tweaks are kept about the same despite less brightness, due to more low level detail showing.


Its a tiny step down from the 250W metal halide in brightness but is well worth the lower running costs, really cheap bulbs, 12,000 hr running life, higher definition, smoother colour spectrum (CRI=96) and much cooler running.
It also hardly varies the colour or brightness throughout its life.
What a bonus bulb!


Overclocking!
Even better, these bulbs can be overdriven.
they dont run very hot so overdriving them is fine as long as they are adequately cooled to preserve life.
Considering they have a life of 12,000 hours, even a quarter of that is still cheap.

The 150W bulb can be used with 250W metal halide kit as this is exactly the same kit it uses but with a 150W ballast normally.
The downside is overdriving shifts the colour more towards the red end the more it is overdriven.

To get round the colour shift problem, I have looked for bulbs with a higher colour temp and found mention of one at 6000 Kelvin.
It would be ideal to get a 150W version of this and overclock it
These bulbs havent reached European shores yet.

The 150W ceramic bulbs have a max current rating of 2.5A and overdriving to 250W will feed it over 3A!
This sounds bad but while traveling round the web I read other projector buffs managed to use them successfully overdriven to 250W so I'm ignoring that for now.
I'll get a 6000K 150W ceramic bulb to test as soon as they are available here.

[gatuus]

hello everyone!
After a long long time thinking about this project and after my wallet allowed me... I've decided to start my homemade projector! =)

I decided to make my own OHP piece by piece instead of buying a 3M one.
Firstable I need to tell you that I'm in America, Mexico to be exactly, and here is really difficult to find a cheap OHP, all of them are over $ 300!!(used) :S. That's why it's easier to make one from zero.
well..
I need to ask some technical issues..
I'm about on getting, from China, the triplet lenses, the condenser and the fresnels.. but I'm in doubt on what to get... ??
I can get in my city an HQI 400W lamp!! from osram for about $ 50 usd and that's what I'm planning to use.. but the doubts arrises when numbers are on the table, I have the posibility to get:

* A vary focus triplet lense from 220 to 360 mm or a
* fixed one between the same ranges?

which one is better? and which one should I need to pick?

Fresnel lens of 320x260x4mm is ok for a 17" LCD?? I'm thinking in 17" to get 1280x1024 resolutions... what do you think? one or two fresnel lenS?? :S

And a Cold mirror reflector(what's this?) 40mm focus is ok?

finally, what kind of condenser len should be better:
* 76.4mm diameter and 127.5mm focus or
* 88.8mm diameter and 260.0mm focus ??

They also have UV filters.. I think that I'll buy one... ,

Thanks for your advices!!

gatuus. =)

[danrok]

Is it still cost effective to build a video projector?

[booman]

Probably not...
This year I purchased a 1024x768 projector for $340.00 and it works pretty well for games and movies.
Its not high definition but its quite an upgrade from my old 27" CRT TV.

[Aedan]

Well, a Panasonic PT-DW90XE will set you back about ?14,000 and needs two UHM 355W bulbs. Does manage 9600 Lumens and a resolution of 1366x768, and 10000:1 contrast ratio... Although I suspect it'd be fairly difficult to build one at that spec and get anywhere near the same picture quality.