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Sony Projector Gets Bright Images From Black Screen
Posted by
timothy
on Wed Jun 23, 2004 07:43 AM
from the paradoxically dept.
from the paradoxically dept.
da_foz writes "Sony has developed a new projector that can give a bright, unfaded picture without the need to eliminate ambient light. The secret is that they project onto a black screen instead of a white one. Their screen uses species filters so that white ambient light is absorbed, but the red, green, and blue light from the projector is reflected. Sony sees a possible use in home entertainment systems because of the ability to have a much bigger picture than conventional TVs as well as businesses adopting the projectors for presentations."
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100.. 160 inches? (Score:3, Funny)
Re:100.. 160 inches? (Score:3, Informative)
Re:100.. 160 inches? (Score:5, Funny)
Parent
Re:100.. 160 inches? (Score:3, Interesting)
Huge picture
You can roll the screen up when it's not in use
This is pretty much perfect for someone like me who lives in a small London flat, but would like to see a decent sized image when watching their DVD collection.
Now if only... (Score:4, Interesting)
This technique sounds really cool though, perhaps I won't need to have all my windows boarded up anymore.
It needs less power... (Score:5, Insightful)
When your screen doesn't reflect so much of the ambient light anymore, you can use a projector that outputs less power. For one, this can lead to less hot projector lamps, thus a longer life for them.
It might also enable the use of lower-power technologies (LED-lasers anyone?), that might in turn make the projectors much cheaper.
Nice work by Sony
Now, is there a physicist in da house who knows how wide the reflection-band (in wavelength-terms) for R, G and B is?
Parent
Re:It needs less power... (Score:3, Interesting)
Re:Now if only... (Score:3, Interesting)
Re:Now if only... (Score:5, Informative)
while I have the same bulb from 2 years ago still burning bright.
it's your use of your bulb and projector.
first off, buy a UPS for your projector and put it on there... only the projector goes on this ups. you want to be sure that your voltages are rock solid and no brownouts get to the bulb. Finally you are making sure that the projector is cool and is allowed a proper warm up and cool down before and after use?
proper care and operation of your projector lengthens bulb life significantly. if you are leaving the house for an hour then LEAVE THE PROJECTOR ON.. I would not shut off the projector unless I was going to have it off for more than 2 hours.
Parent
Re:Now if only... (Score:3, Interesting)
If so, my wife will love you - I tell her to turn off the TV if she's away from it for more than 30 minutes.
Re:Now if only... (Score:4, Interesting)
turning that bulb on and off does more to it's life than leaving it on... now leaving it on 24/7 will get you to the diminished light output and dead point far faster, but you can easily triple your bulb's typical life by leaving it on when you are not going to be watching it for short peroids of time.
also don't even be tempted to enclose the projector. it must have free air flow from all sides and NOT be located near a AC/heat vent.
Parent
Woah, neat! (Score:3, Funny)
Finally (Score:5, Funny)
Are three colors protected by patents? (Score:5, Interesting)
I assume the three frequencies that are reflected are fairly well tuned. I wonder if this means I will be stuck purchasing a Sony projector to match these? I also wonder if Sony may be able to stop others from making matching projectors since they probably own some Patents around this technology?
Re:Are three colors protected by patents? (Score:3, Interesting)
Sony is no Redmond company. they will most likely license the technology to competitors, or Sony's competitors will come up with something similar or better. I don't know if Sony has any type of deal with this "Stewart Filmscreen" company, but Sony knows how risky it is to play "exclusive" in the market and make things incomatible from rest of the world. Sony wil
Re:Are three colors protected by patents? (Score:5, Insightful)
Err, one word, Memory Stick, well, two words then.
Parent
Re:Are three colors protected by patents? (Score:3, Informative)
DAT, Mini-disc, betamax.
Will they never learn?
Re:Are three colors protected by patents? (Score:3, Insightful)
Lasers and Notch Filters (Score:5, Insightful)
Re:Lasers and Notch Filters (Score:4, Informative)
(*since reflected laser light will blind you and/or permanently burn the image into your retinas.)"
There is nothing special about laser light in itself that causes blindness, it's just that most lasers are very directed and focused putting a lot of energy into a small spot.
The military (and others I would guess) is working on a head mounted display that rasters the image directly on your retina with a low power laser.
So a "low" power laser would be fine.
Parent
NOT a new projector... (Score:5, Informative)
Who wrote this? (Score:4, Informative)
In a bright room, the image on the screen is brighter
No, it isn't. It's clearer, it might _appear_ brighter because of that, but there's no way it could actually _be_ brighter. Unless the technology does something not described.
Since Thomas Edison introduced motion-picture projectors more than 100 years ago
I could have sworn the motion picture projector was introduced by Lumiere.
Bright: luminance versus saturation (Score:4, Informative)
The common vernacular "bright" can either refer to luminance (close the shades, the light's too bright), or it can refer to color saturation (Can you tone down that bright green to a mere pastel?). A projector screen that reflects ambient light is going to reduce color saturation; and one that absorbs ambient light will increase color saturation, i.e. make it brighter.
Parent
submitter is an idiot... (Score:4, Informative)
fourth sentence of the article:
In apparent defiance of color theory -- that dark surfaces absorb light and white surfaces reflect it -- Sony Corp. has unveiled a black screen that allows a regular digital projector to vividly display TV images and business presentations in a brightly lit room
jesus christ, is it too much to ask to have someone read the fscking thing first??
It's bound to catch buyers with that contrast (Score:5, Insightful)
I bought some high-end binoculars a while back. When you're looking through all the Nikons and Swarovskis and Leicas side by side, you start to realize when your eyes feel the little zing. It isn't pure resolution that does it, and your eyes compensate rapidly enough to changes in brightness (due to objective size or quality) that you don't often perceive differences except at dusk and dawn. (The only exceptions for me were old-style tank commander Zeiss binocs. Very bright.)
But when you hit a binoc that felt right for contrast, ahhh -- those were my handful of last choices. It's like seeing the world with the slanting light at around 6:30 on a summer night -- everything just pops out, so clear, and the slight 3-D exaggeration of the binocular view brings it out just that little bit more. The optics store people said that was a pretty common reaction -- a slight edge in contrast was a huge advantage.
Sounds like this screen has that going for it. Big selling point, next to potential competitors, if they can get it around the right price point.
Methinks we aren't getting the whole scoop here. (Score:3, Insightful)
Sony engineers worked from the basic principle that projectors, like all TVs and monitors, form colors by blending three primary hues: red, green and blue. They came up with a filter that allows the screen to reflect only red, green and blue light. The other light in a room, such as white incandescent or fluorescent bulbs, isn't reflected.
Man I hate it when the newspapers print stupid things. Whaddaya wanna bet they are using something like polaroid or narrow bandpass quarter wave plate filters with a similarly filtered projector? What would be cool is a fluorescent screen and a projector that uses light (UV?) outside the visible spectrum. Then the screen really could be visibly black but it would still glow when stimulated by the projector.
Re:Methinks we aren't getting the whole scoop here (Score:5, Informative)
Sure there is, there's no such thing as white monochromatic light, but white light exists. The term "white" (whether it be talking about light, sound, etc.) simply means that the energy is distributed evenly across all frequencies (technically between 0Hz and infinity, but in practice we're talking about more or less evenly over a given band of frequencies). Since the energy is distributed over such a wide frequency band, the energy of the white light in the very fine bands used by projectors will be very small, so by absorbing everything else you will almost be eliminating the white light's energy.
Trueth be told, unless you're talking about monochromatic light, the simplistic names of colours only describe what we see - they can be generated by any number of combinations of different frequencies. I.e. monochromatic orange light has a wavelength of 590nm, but that would look the same to us as a mixture of red (650nm) and yellow (570nm) light (or any number of combinations of different wavelengths).
Parent
Re:Methinks we aren't getting the whole scoop here (Score:5, Informative)
I'm not sure they'd put too much dependence on angle, either-- most projectors these days are designed with an enormous optical offset (The popular Sanyo Z2 can be offset by 1/2 screen width and 1.5 screen height) and digital keystone correction (Allowing for projector placement even farther outside the offset range by correcting the shape of a picture projected at an angle). Lots of people use projectors but don't have a room situated so that the unit can hang conveniently from the ceiling dead center.
Parent
DLP or similar (Score:3, Insightful)
Screens that Heterodyne Infrared Light (Score:3, Interesting)
These crystals can be ground up and painted onto a screen or even the side of a building. Then all you need is an infrared laser to scan the the sreen and you have an extremely bright and cheap full color display.
I haven't heard much lately about their progress so I assume they are having some technical or financial delays.
Re:Screens that Heterodyne Infrared Light (Score:3, Informative)
Percentage reflectivity, please... (Score:3, Insightful)
What we need to know is: a) what percentage of white, ambient room light does the screen reflect? It's not zero, and the screen probably looks like a dark grey. b) When the projector is projecting "white" light, what fraction of that light is reflected? Not only is it less than 100%, it's probably less than a white screen would reflect.
Other things one would like to know are whether the filters that do this magic cause any visible graininess, and over what angle the reflected light is reflected.
It's the SCREEN that is special, not the projector (Score:5, Informative)
Any projector with the same type of bulb---and in home theater nowadays, there are only two main types (Xenon and UHP), will work with this setup. And Sony could conceivably make a similar screen for the other bulb type too.
There have been so many dupe threads over at AVS Forum [avsforum.com] (by far the best place to go to discuss anything home theater) that it is getting a bit irritating.
TRATEOTU (Score:3, Funny)
I always wondered how Hotblack Desiato's ship was detailed so, well, black. Now we know. It's still a shame about the tax thing.
NOTE: If you don't understand this post, don't moderate it! Yes, I mean you. I'm not being funny here! Stop it!
Could we have a notebook screen instead? (Score:5, Insightful)
It seems like a feasible variation, at least to me -- keep the mostly-black coating to absorb nuisance ambient light, but allow transmission at narrow RGB wavelengths. Then backlight it with an LED screen, with the diodes tuned to the three transmission frequency ranges.
Don't know whether it's technically possible, but if it is, I bet it's in the works already.
Patent 20040061935 reveals some details (Score:3, Informative)
Obligatory Quote... (Score:3, Funny)
Re:Black? (Score:5, Insightful)
Parent
Re:Black? (Score:3, Interesting)
If it looks black to the naked eye, isn't it then... black?
I wonder if it works with any projector, or just some specific kind. I always liked the picture quality of LCD projectors, but the fact that they require a very dark room to get any kind of reasonable contrast has kept me from buying one. Now this might change that.
Re:Black? (Score:3, Informative)
Re:Black? (Score:3, Informative)
It continues a trend that began two years ago when Stewart Filmscreen Corp., a leading U.S. maker of screens, began selling a light-gray screen that enhanced the images from projectors using digital chips.
I'm just guessing, but since they said "digital chips" rather than LCDs, maybe it has to do more with DLP Projectors [about.com] rather than LCD Projectors [about.com]. Although LCD projectors can be brighter than DLP projectors, the pixels aren't as obvious on DLPs. Perhaps since brightness is a problem, this screen may be b
Re:Black? (Score:5, Funny)
Parent
Re:Black? (Score:5, Insightful)
Actually, if it only reflect three specific wavelengths
then it's probably the _blackest_ thing you've ever seen.
Parent
Re:Black? (Score:5, Interesting)
But still I suspect that their filters probably filter out some of the visible light coming out of the projectors, making this black screen not quite as bright as a comparable white reflective screen. After all it has to be easier to make a material with close to 100% diffuse reflectance [analytikoptics.co.uk] across the whole spectrum than to create something that's near 0% everywhere except for three narrow notches which are near 100%. But I'm no expert on light
So I'm thinking it's highly unlikely that the the filters come anywhere near 100% black in the non-reflected parts of the spectrum. No doubt this is the blackest projection screen you've ever seen, but I really doubt it will be the blackest thing you've ever seen. Especially if you've seen Undercover Brother [undercover-brother.com]
Still it's a pretty neat trick. Anyone know how they make passive filters with such sharp tuning to specific frequencies. Is it some kind of diffraction thing?
Parent
black != "black body" (Score:5, Insightful)
Of course it is. Every black object in the world reflects some light.
You are confusing black bodies, an abstract notion defined by physiscists which does not exist in the real, physical world, and the color black, which our eyes percieve just fine whether or not it is a shiny surface with a lot of reflection, or a matted surface with minimal (but still greater than zero) reflection. The black BMW I had the misfortune of following the other day positively glinted in the midday sun.
With light, black is defined as the abscence of color. With pigment, black is the presenece of all color (analogous to white light).
Parent
Re:black != "black body" (Score:4, Informative)
Cyan is the abscence of red. It absorbs red light.
Magenta is the abscence of green. It absorbs green light.
Yellow is the abscence of blue. It absorbs blue light.
And the fourth color found in this group is black, a mixture of all 3 pigment colors. Black pigment is not the presence of all color. It's the presence of all light absorbtion.
The way that black BMW glinted in the sun is a result of the finish. A nice clearcoat tends to intercept and reflect some full-spectrum sunlight before it gets absorbed by the black paint. A matte finish just diffuses more, yet still reflects that light (just not all in the same direction).
So... black stuff doesn't reflect any light. At all. It's just the nearby non-black stuff that reflects light, making the entire object appear just almost black.
Parent
Re:black != "black body" (Score:3, Informative)
A black pigment contains pigments of all colors, which are defined on the inverse of the light they produce.
Overly simplified example:
Red paint looks red because it contains blue absorbing pigments and yellow absorbing pigments and reflects red light.
Black paint looks black because it contains red, blue, and yellow absorbing pigments and reflects much less light.
Re:black != "black body" (Score:3, Interesting)
This is all about the difference between the additive and subtractive colour models:
http://en.wikipedia.org/wiki/Color_space#Commonly_ used_color_models [wikipedia.org]
Re:isn't white light made up of RBG? (Score:4, Informative)
Parent
Re:isn't white light made up of RBG? (Score:3, Informative)
Red+Green+Blue light _looks_ white to us, because our eyes cannot distinguish it, as they have only 3 receptor types that are tuned to those wavelengths of light.
White light contains all frequencies of visible light. We can see all frequencies of visible light, it is simply that we cannot distinguish them from an appropriate combination of the two nearest frequencies our eyes are tuned to.
This screen filters out the frequencies other than narrow bands around those used by the projector, which are (ap