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How long before the metal halide lamp in projectors

M

Minerva

Platinum Member
Lumileds and Nichia are making great progress and what was deemed impossible 100 lumen/watt barrier is literally right around the corner. Efficiacy ramp up will assume a hockey stick curve meaning these devices will replace ALL electrical powered light sources in the not so distant future.

Now that the key disadvantage of projection technology of today (lamp life) will be handled with aplomb with aforementioned technology, what about the color wheel? What is the practical MTBF of the color wheel motor? They're similar to a hard disk motor with FDB bearings right? Should be comparable to the MTBF of the LED source. Are these motors subject to contamination by indoor air particulates such as cigar and pipe smoke, pet dander, ash and heaven knows what else is people's houses? (incense smoke too! 😉 )
 
I can't really comprehend most of your post due to general ignorance on the subject - but I can't wait for the day when everything is LED 🙂
 
Originally posted by: djheater
It's intersting to think that my grandchildren will be confused about what to do when a light burns out...
Click to expand...

In my day we had these miniture rods that we superheated ....:evil:
 
leds aren't as efficient as you think. scroll down http://www.dansdata.com/danletters079.htm

theres the sony flat panel lit by a series of red/blue/green leds as backlight for better color range. don't need uber brightness of a projector bulb to do that. and projector bulbs are HID, led's not gonna touch that anytime soon. when other flat panel makers come out with the same tech it'll start to go down, for now its VERY expensiive
 
Flat panels and PJ's are completely different things and yes LED's will definitely replace other sources. It hasn't happened yet.

Just as blue ray hasn't replaced the DVD.

This is hardly what I would consider highly technical. We were discussing this at the dinner table! LOL

Now if we discussed how that would be another thing. 😉
 
Originally posted by: Minerva
Lumileds and Nichia are making great progress and what was deemed impossible 100 lumen/watt barrier is literally right around the corner. Efficiacy ramp up will assume a hockey stick curve meaning these devices will replace ALL electrical powered light sources in the not so distant future.
Click to expand...
Have the second-generation Luxeons (R2? I forgot what they're called) been released yet?

HID and CCFL still rule their respective applications. Their development will continue, holding LED off for longer than you seem to expect.

What's a color wheel?
 
Originally posted by: mchammer
HID>*
Click to expand...

As of now, agreed.

Originally posted by: mchammer
Originally posted by: Minerva
DLP Color Wheel Explained Here
Click to expand...

Not needed if you use three DLP chips like the $$$$ projectors do.
Click to expand...

Well that makes things more complicated discussion-wise because if you're using three chips you have a prism to refract the light from the MH lamp. Doing this with an LED would be silly. Since narrochromatic emitters are much higher in efficiacy NOW this may be used in the introductory devices. It's just a matter of how good the normalization between Red, Green, and Blue channels would be as the efficiacy declines from left to right respectively.

 
Originally posted by: Minerva
Originally posted by: mchammer
HID>*
Click to expand...

As of now, agreed.

Originally posted by: mchammer
Originally posted by: Minerva
DLP Color Wheel Explained Here
Click to expand...

Not needed if you use three DLP chips like the $$$$ projectors do.
Click to expand...

Well that makes things more complicated discussion-wise because if you're using three chips you have a prism to refract the light from the MH lamp. Doing this with an LED would be silly. Since narrochromatic emitters are much higher in efficiacy NOW this may be used in the introductory devices. It's just a matter of how good the normalization between Red, Green, and Blue channels would be as the efficiacy declines from left to right respectively.
Click to expand...

You mean like sodium lamps? IMO power consuption is not too big of a concern in this area and the arc in a HID lamp is smaller than in a sodium lamp which is better for focusing. It would also be possible to use three HID's, one for each color.
 
Sodium lamps have lines in all the wrong places and are too polychromatic so we're back to refraction and conversion losses.

RGB channels with a triple chip system would be provided with Red, Green, and Blue LED's. These are the narrowchromatic sources with a spread not as narrow as a stimulated source (laser) and not wide like other common sources whether discharge or resistance (incandescent - tungsten) based.

Sulfur (microwave-plasma) discharge can be efficient and have good spectra but that's another discussion altogether. 🙂


Originally posted by: Skiguy411
Uh....I have a metal Halide lamp in my home built projector?
Click to expand...

Huh? You built it so you should know! 🙂

 
Originally posted by: Minerva
Sodium lamps have lines in all the wrong places and are too polychromatic so we're back to refraction and conversion losses.

RGB channels with a triple chip system would be provided with Red, Green, and Blue LED's. These are the narrowchromatic sources with a spread not as narrow as a stimulated source (laser) and not wide like other common sources whether discharge or resistance (incandescent - tungsten) based.

Sulfur (microwave-plasma) discharge can be efficient and have good spectra but that's another discussion altogether. 🙂


Originally posted by: Skiguy411
Uh....I have a metal Halide lamp in my home built projector?
Click to expand...

Huh? You built it so you should know! 🙂
Click to expand...

I still think focussing them properly would be very hard and as it stands right now they are not nearly bright enough, cooling might also be a problem.
 
Originally posted by: Skiguy411
Uh....I have a metal Halide lamp in my home built projector?
Click to expand...

Yeah, and as I'm sure you've figured out, they get reallllly hot. And they're prone to exploding.

And need a huge ballast.

(built a projector aswell)

I personally can't wait till LEDs replace all light..replacing bulbs after years and years of use would be awesome.
 
Originally posted by: Goosemaster
Originally posted by: djheater
It's intersting to think that my grandchildren will be confused about what to do when a light burns out...
Click to expand...

In my day we had these miniture rods that we superheated ....:evil:
Click to expand...

Your penis IS an effective light source.

And yeah, I'd much prefer the blueish glow of LED streetlights to the orange crap we have now.
 
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