I've been noticing for a while now that commercial lcd projector lamps look something like what is below ( If anyone could confirm this that would be great because i haven't looked at one personally just pictures on the web) ...It's quite different than what us DIYers have been doing (i personally haven't done anything yet)....I think the actual bulb is placed lengthwise in the reflector with a wire attached to end that sticks out instead of that end being inserted into a holder. I guess this is so less light comes directly from the bulb and most or all of the light comes bounced off the reflector and, i guess, parallel.
So I was wondering since the commercial lamp makers do it like this (pretty much all of them) then why aren't we trying a similar design, since it seems to be optimal...Obviously ALL the design is in the reflector which i guess is mathematically designed to reflect the light optimally (and filter out UV).
Any thoughts?
So I was wondering since the commercial lamp makers do it like this (pretty much all of them) then why aren't we trying a similar design, since it seems to be optimal...Obviously ALL the design is in the reflector which i guess is mathematically designed to reflect the light optimally (and filter out UV).
Any thoughts?
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Where do you suppose we could find that kind of reflector? What might the cost be? Does that design overcome the point light source problem in some way, letting them use a larger arc lamp?
My guess is that they (projector makers) will have some kind of legal control of the sales of them and that will be a tough one to deal with. Just a guess though.
CB.
My guess is that they (projector makers) will have some kind of legal control of the sales of them and that will be a tough one to deal with. Just a guess though.
CB.
if we had one reflector off a burned out lamp module then we could produce as many copies as we'd like by casting them with RockHard.
Um well that depends, you couldnt cast the inside only the outside( they are pressureized) however once My lamp burns out we can try it. Still remains a prob that we dont have a source for lamps that fit that small of a space, HQI lamps are still much bigger then the actual projector bulbs.
The actual arc isn't too much larger though right?
What do you mean we couldn't cast the inside because it's pressurized? You mean there is no way to seperate the reflector from the rest of the assembly without something exploding or cracking??? I didn't see anything to indicate that....
So if we could seperate the reflector, then we could fill it with RockHard so that we get the shape of the inside of the reflector, then use that negative as a form to cast the reflector itself...It would be extremely easy.
But please explain the pressurized part...
What do you mean we couldn't cast the inside because it's pressurized? You mean there is no way to seperate the reflector from the rest of the assembly without something exploding or cracking??? I didn't see anything to indicate that....
So if we could seperate the reflector, then we could fill it with RockHard so that we get the shape of the inside of the reflector, then use that negative as a form to cast the reflector itself...It would be extremely easy.
But please explain the pressurized part...
OK yea Guess I should clarify, OK the lamps your referring to are UHP Ultra high pressure, But I honestly dont know if that is the bulb casing or if there is a pressurized " core" thats inside, I cant tell from my lamp, However the bulb has a glass cover over the " front" part. So I honstly dont know if thats the pressurized part, I know reg light bulbs are. am I gonna risk it by taking a hammer to it heck no LOL. So to the spark gap, Im thinking a HQI bulb still has a longer spark gap. However that said lets just assume its the same...........the hqi bulb still wouldnt fit inside the reflector or at least you would have to cut the sides down( im gonna draw a pic) so the ends would stick out........drawing pic...........wow that sucked here it is, I cheated by coping the other pic and adding my master art skills. as to the spark gap even on the commercial projector its smaller then the HQI bulb. does that make any more sence, dunno if the reflector itself is a better Idea then any others we have thought of( making) hope I didnt make the confusion more prevalent
Maybe a person could collect a number of commercial bulb reflectors from old discarded units. Then maybe they could be modified to our needs.
I would pay 20 bucks or so for a reflector if enough people were reporting success in using them with other bulbs.
CB.
I would pay 20 bucks or so for a reflector if enough people were reporting success in using them with other bulbs.
CB.
Ok, but what i'm saying is that from looking at all these newer commercial lamp assemblies, it seems like none of them use light that eminates directly from the bulb itself. I say this because the "end" of the bulb is what points out from the assembly and there is a wire attached to this end (the end that sticks out toward the direction the light is traveling in --- see my pic again...i include it again below).
It seems that these lamps use ONLY light that is reflected off the reflector....and don't use any light directly from the bulb. This means that the design of the reflector is very precise and mathematically derived to yield a light beam suited to the projector. And since all these "newer" lamp assemblies that i'm talking about basically use the same design (pic below), i gather that these reflector designs are mathematically designed to optimally reflect as much of the bulb light as possible into a more or less spotlight type "straight" beam.
So what i'm thinking is since so much money and thought has been put into the design and shape of these reflectors, then maybe THAT is the best configuration for projector lamp design....
So what i'm saying is that maybe we could stick a HQI into a copy of one of these reflectors, in the same position as the usual bulb would have been placed (or maybe we can find a commercial bulb/reflector assembly where the bulb is pretty similar to a HQI--not exactly similar but maybe we can find a best match), And stick the HQI in like i'm saying; instead of holding the HQI in a double ended assembly, we could attach a wire to one end and stick it in lenghtwise like the commercial lamps are doing.
FREAK, could you maybe take a picture of the commercial lamp you have?
It seems that these lamps use ONLY light that is reflected off the reflector....and don't use any light directly from the bulb. This means that the design of the reflector is very precise and mathematically derived to yield a light beam suited to the projector. And since all these "newer" lamp assemblies that i'm talking about basically use the same design (pic below), i gather that these reflector designs are mathematically designed to optimally reflect as much of the bulb light as possible into a more or less spotlight type "straight" beam.
So what i'm thinking is since so much money and thought has been put into the design and shape of these reflectors, then maybe THAT is the best configuration for projector lamp design....
So what i'm saying is that maybe we could stick a HQI into a copy of one of these reflectors, in the same position as the usual bulb would have been placed (or maybe we can find a commercial bulb/reflector assembly where the bulb is pretty similar to a HQI--not exactly similar but maybe we can find a best match), And stick the HQI in like i'm saying; instead of holding the HQI in a double ended assembly, we could attach a wire to one end and stick it in lenghtwise like the commercial lamps are doing.
FREAK, could you maybe take a picture of the commercial lamp you have?
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Ok property I see what your saying now. I attached a pic with 2 diff views and the white lines show the bulb position and the wire position. However I can confirm that the light emitting portion isnt at the end of the bulb (like in your pic) its twards the middle( HQI like) and this new thought on lights is highly interesting because it means that the light is emitted to the side of the lamp not directly forward( well it does go forward but only via the reflector) hope that helps some more or ignites more thoughts.
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Yeah that is what i'm finding interesting...The light is not emitted forward from the bulb but comes, all of it, bounced off the reflector.
Yea I wish I could say I had a almost dead bulb But the pic is of a brand new bulb and My current bulb has like 1600 hrs still on it. However that said, Even if we are able to make a mold, how Smooth would the surface be? and what kind of paint would we use to make the reflector? this thing is madddddddddd reflective.
Smoothness is easy and paint is easy...RockHard cures extremely smooth (and it can be sanded)...And we can paint it with
high-heat-resistant Chrome or Silver paint (I've already done searches for this type of paint and found many places that sell it).
The only downside i can see is that these commercial reflectors (as JBELL said) are probably designed to filter certain lightwaves in order to alter the CRI of the light and filter out things like UV and IR....That's why some of these reflectors appear semi-translucent (not yours though VF, yours seems to be purely reflective. EDIT: actually yours also seems to be a tiny bit translucent..espescially in the violet range)...But these things could be handled by us with things like UV filter glass as we've been doing (or not doing)... The main purpose of copying the reflector would be to make use of a reflector that has surely been mathematically designed over thousands of autocad hours (not to mention the hundreds of thousands of dollars spent on engineers to do the designing) for the sole purpose of directing the light optimally.
EDIT: Then again we could also look for a source of burnt out lamp assemblies and rip out the reflectors...If we can find a lamp with a bulb with arc that matches an HQI arc closely enough.
high-heat-resistant Chrome or Silver paint (I've already done searches for this type of paint and found many places that sell it).
The only downside i can see is that these commercial reflectors (as JBELL said) are probably designed to filter certain lightwaves in order to alter the CRI of the light and filter out things like UV and IR....That's why some of these reflectors appear semi-translucent (not yours though VF, yours seems to be purely reflective. EDIT: actually yours also seems to be a tiny bit translucent..espescially in the violet range)...But these things could be handled by us with things like UV filter glass as we've been doing (or not doing)... The main purpose of copying the reflector would be to make use of a reflector that has surely been mathematically designed over thousands of autocad hours (not to mention the hundreds of thousands of dollars spent on engineers to do the designing) for the sole purpose of directing the light optimally.
EDIT: Then again we could also look for a source of burnt out lamp assemblies and rip out the reflectors...If we can find a lamp with a bulb with arc that matches an HQI arc closely enough.
New thought to continue your thought, I do bet the commercial bulbs do filter diff types of light but if we use a HQI bulb it already has the filters in place and " is what it is" so one would think that it would work fine retrofitted into the " mold" However I thought of the new problem. These bulbs are supposed to go through > 1 inch lcd's in projectors so how would this say transferr to using in a OHP or even just using a custom case and 15" lcd? On the OHP I would think you would still need a old school " deep/tall" one to get enough room for the light to spread out. Though I will see once I take a look at the OHP I have coming that has the seperate reflector and see how big that is in relation to the commercial bulb. and with that " IM SPENT"
I have open up my lp720 before just for the heck of it to see the optic system. I think you are right videofreak those lamps or reflectors I think were engineer to gather all of the light and send it right into a mini fresnel lens about 3 inches square, there are a couple of them I recall. So unless you are using a condenser lens or something else to spread the light out for a bigger fresnel for your lcd panel you will see a very bright spot right in the middle of the lcd. This way might be more efficient since you are using all the light from the bulb.
The lamp in the picture was from a 3m projector. As you can see it is not enclosed, I think some are enclosed is just for safety incase it blew up. It sticks out about 1/2 inch. So I think if you can retro fit anything in there the reflector will do the job.
Some ideas....
The lamp in the picture was from a 3m projector. As you can see it is not enclosed, I think some are enclosed is just for safety incase it blew up. It sticks out about 1/2 inch. So I think if you can retro fit anything in there the reflector will do the job.
Some ideas....
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Video Freak said:
Yeah, i was avoiding that point....This would probably work best with smaller LCDs...but somebody just posted a thread saying that the PSone LCDs can get VGA resolution...And that's REAL BIG news (don't know about number of colors and response times etc.. though)
Or like PIZZI is saying, maybe we could put a condensor lens ( PCX lens?) between the lamp and LCD to expand the light...
The main benefit we are looking for anyway is to Use as much of the light off the bulb as possible, And to use it as well as possible. And these commercial reflectors seem like they are designed to do just that.
yea I dunno it seems as though it will be a try and see deal, cant do that here( me) untill my lamp burns out and believe me I dont rush that LOL. So Hopefully someone here will have a dead lamp sometime.
This is actually exactly what i planned on doing soon. The only difference is i planned on putting it horizontal to the reflector rather than actually in it. Maybe I will try to squeeze it inside and let ya know what happens. The bulb in mine should be easy to pull out because the plaster stuff on back is already unattached. And the transmissivity of the reflector depends on the heat. I took it out when it was still hot (i know i shouldnt have blah blah) it was way colorfull and more see through. When it cooled down it was more of a dense silver color.
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