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Sony Projector Gets Bright Images From Black Screen
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."
If it reflects _anything_, it isn't black.
It seems this is a surface that reflects only very selective frequencies, those used by their emitters. An interesting idea, but calling it black is deceptive.
I can see the use in business and public presentations. But other than the few home cinema zealots with giant rooms set up like theaters, how is this useful in the home? To me it seems like having a 24 inch penis. Sure, it'd be big and impressive, but not of much practical use to anyone.
...they could come up with a lamp that would actually last. I've gone through at least 6 InFocus projectors in the last 1.5 years due mainly to bulb failure.
...hey, what's that bright thing in the sky outside?
This technique sounds really cool though, perhaps I won't need to have all my windows boarded up anymore.
Absorbing everything except the wavelengths that the projector produces (and which the human visual system will still perceive as the full spectrum of colours) is *very* clever. If only the ambient light wasn't from massed banks of computer monitors...
"Little does he know, but there is no 'I' in 'Idiot'!"
We'll finally be able to see the Gettysburg Address Power Point presentation the way Lincoln intended it to be viewed.
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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?
does this mean i can throw out the black rugs and paint the walls a night light colour instead of dark red? i'd pay for that...
It would seem that the ultimate version of this would use RGB lasers as the light source and notch filters on the screen. The narrowness of the notches would determine the depths of the black. The biggest trick would be in tuning the notch filters to reflect the off-axis, angled laser light.
Two wrongs don't make a right, but three lefts do.
I just bought a Sony VLP-HS20 and now they come out with this, I could have painted the walls white and hung a black screen :-( Instead of painting them dark and hanging a white screen.
This isn't a new projector. It's a new type of screen that only reflects the projector light, absorbing the ambient light, so the image remains clear even in a bright room. It works with regular projectors. I'd at least expect the submitter to RTFA...
Igor Presnyakov stole my hat
``Sony Projector Gets Bright Images From Black Screen''
Main screen turn on!
Please correct me if I got my facts wrong.
As long as they don't sell that screen material for the same price as a plasma TV of the same size, of course.
Just installed a Sanyo Z2 16x9 projector at home, and despite the obvious dailight/sunlight issues, it's absolutely incredible to have a 3m x 2m high quality picture!
Unfortunately it only works with black light.
Philip
Signatures are broken
The author of the article doesn't know what he's talking about!
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.
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?
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What does any of this have to do with the topic at hand?
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the majority of companies that have projectors tend to use them for giving demonstrations outside of their own facilities.
this is going to mean that the place you are going to be using the projector is going to have a white screen instead of a black screen. not to mention, if someone else comes to your facility to do a demonstration, how well are other people's projectors going to work on your black screens?
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??
---
Is this the MPAA? Is this the RIAA? Is this the DMCA? I thought it was the USA!
...are highly sought after by women with 24 inch receptors.
"Species Filters"?
-USR1
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.
"Fundamentalism" isn't about divine morality. It's about human authority.
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.
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- Doug McKenzie
The article specifies that this is for use with digital projectors. I assume the reason for this is that single chip DLP projectors don't actually project white light onto the screen. The red, green and blue components of the image cycle so fast on the screen that your eye perceives this as different shades and combinations including white. All you need to do is have the screen absorb white light while reflecting red, green and blue and there you go. This is really an ingenious use of this effect, but I wonder if it is unusable with a 3 chip DLP projector that shows all components at the same time? You would at least need a more sophisticated screen in this situation.
Dewey, you fool! Your decimal system has played right into my hands!
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.
you insensitive clod!
I'm sure it will increase the contrast, but what about the actual brightness. The article doesn't mention the net reflectivity or gain of the screen. It also doesn't mention dispersion / white spot elimination and other important factors in screen design.
There are several other bits of screen technology that have been floating around the past few years. www.mocomtech.com has a line of 'dupic' clear screens comrised of essentially an array of lenses. These screens not only offer high contrast but can be viewed from both sides with equal brightness and clarity. There are also large flat and parabolic screens which deliver up to 20 gain, yet have reasonable viewing angles.
see www.projectorcentral.com to learn more about screens and projectors.
John Soward...University of Kentucky
The story is not about a projecter [sic], it's about a new type of screen material.
The way I read it, any projector works on the screen material, and gives increased brightness as compared to projecting on a regular (ambient-reflective) surface such as a wall...
main(O){10<putchar(4^--O?77-(15&5128 >>4*O):10)&&main(2+O);}
If the screen absorbs the color white, how well would it work when the image being projected has white colors in it ? - Am I missing something ?
"...as well as businesses adopting the pjojectors for presentations."
These new image creation devices are called pjojectors, similar to the original and well known 'projector', except with the added function of being able to project an image onto a black screen. Well done Sony, always innovating.I couldn't think of a sig.
Is the picture ofthe display seems a bit misleading, I would think that the narrow bands of the ambient light that matches the projector colors are also reflected, of course that might be much less than the bulk of the ambient light, explaining how this thing works.
If you combine RBG light you get a white ish looking light. So how does this work? Is it reflecting only the light frequencies the RBG projector is showing.
Each type of light bulb gives off multiple frequencies some of which must overlap. Unless they're also using the incoming angle to control reflectivity.
There seems to be more to this than the article is describing.
doubles as a mirror for smurfs and _some_ teletubbies....
A lot of time projectors are just pointed at a wall. This projecter won't have the versitility to do that.
Umm, yes it will. You just won't work properly in a lit room.
"Yes, what you thought was a black screen actually shows images of you whaling away in the Oval Office, Mr. President."
So, are you just going to meta-describe your shopping experience, or are you going to actually name the brand/model you bought that had such noticeably sharper contrast?
I, for one, would like to know.
Hollywood, Television, has become the dream machine. We need to take that back; each of us is a Dream Machine
If it reflects _anything_, it isn't black.
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).
The Future of Human Evolution: Autonomy
burn in? Does this screen still get it? I know that one of the problems with a lot of people is that they sometimes leave a projector on and get burn in on the screen. Example: I know a guy who had street fighter going on a projector, left it for a long time, and now has a permanent health bar on both sides of the screen.
Even with the best surround sound, there is still the issue of fan noise. If you enclose your projector in a cabinet, you shorten the bulb life due to heat. I've used various projectors over the years, and always end up back at my HD flat-tube system, because it has good contrast and is quiet. If they fix the contrast problem, I may give projectors another look, but the fan noise should become top priority.
-Patrick
"They never stop thinking about new ways to harm our country and our people, and neither do we."
Whats a pjojector?
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.
I would like to see the PDF specs and bugmenot has no log-in information
this sig intentionally left blank
Never mind about the projectors. I want to be able to use my laptop outdoors. There must be a reason I have wireless lan and a balcony. Since the root of all problems is that screens have luminosity instead of reflecting existing light selective reflection seems very interesting.
An LCD project emits red, green, and blue light at specific frequencies. The screen is tuned to reflect these and only these frequencies as much as possible. Ambient "white" light includes the whole visible spectrum, the vast majority of which isn't reflected by the screen. Only those frequencies close enough to the LCD frequencies would be reflected.
completely skirting around the fact that THERE IS NO SUCH THING AS WHITE LIGHT!
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).
http://blog.nexusuk.org
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.
I don't think it can be a narrow bandpass filter - if you have 3 lasers, red, green & blue, you will not be able to create a full range of images. You need a variety of incoming wavelengths to generate images. Therefore the screen must respond to many incoming wavelengths.
Also, they claim it works with any projector. I would guess it works by having a strong angle dependence to its reflectivity. Since incoming light from the projector is very close to 90 degrees from the plane of the screen, you could filter out incoming light at other angles.
Another possibility (but needs a custom projector) is having a polarizer on the projector, and a corresponding polarizer on the screen. Ambient light from the room will not have the correct polarization, and will be suppressed.
How much more black could it be? None, none more black.
YHBT HTH HAND.
Xeno.
I could see this as being a fairly inexpensive interim step for those theaters who want to increase quality but aren't ready to shell out the big bucks for a digital projector.
Don't you know EVERYTHING was invented in Amerika?
Mostly by <American Hero> Tomas Alba Edison </American Hero>.
I don't have a sig.
They are using this technology to make objects "Invisible", here's how.
They have a subject standing in front of an object, say a wall or even street traffic. Behind the person is a camera that records the scene behind the person.
The person is dressed up in the special black fabric that reflects the RGB light.
A projector in front of the person projects the image from the camera stationed behind the person, onto the person... this makes the person the movie screen and enables you to "see through" that person.
I've seen this done and it is very cool and could even be described as quite errie to see a truck drive 'through' a person, or more precicely being able to see through the person and see the truck passing by behind them.
Good security is based upon reality and common sense. Common sense is a function of having common knowledge.
Well just will be a boon for the drive-in movie crowd in Alaska during the Midnight sun
I make my face look like this and concerned words come out.
As others have pointed out, a truly black screen wouldn't reflect the projector's light. And, conversely, a screen that is able to reflect the red, green, and blue light from the projector will reflect some of the ambient light, which contains some light at the projector's R, G, and B wavelengths. It's too bad the article has to describe it as "Gee whiz! it's technological magic!"...
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.
"How to Do Nothing," kids activities, back in print!
The technology here is in the screen, not the projector. In particular, the screen absorbs most light, with the exception of the primary bands illuminated by the projector's bulb.
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 (by far the best place to go to discuss anything home theater) that it is getting a bit irritating.
Reading the article (although it is a little shy on detail) suggests it is bandpass filters in addition to what you suggest. I'm not sure why you think you need more than R, G, and B to produce all the colors present in RGB video. To reproduce the entire visible color gamut, you'd need more than RGB-- but RGB video has already reduced the color gamut significantly from what you can see. And, conveniently, consists of exactly three narrow wavelengths of light, and nothing else. Your suggestion that images require "many wavelengths of light" is completely incorrect. You'll have issues if your only source of ambient light is a bank of computer monitors, though, as they'll fall right into that nice RGB range.
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.
But I still dont understand how the screen works with current projectors. Current projectors use a broad band light bulb and separate the spectrum into three componenets. They cant be highly narrowing the bandwidth of the of these components or they would be throwing away most of the light.
ergo, current projectors must be emitting most of the visible spectrum not just narrow R,G and B. So how can the screen be selective. I dont get it.
I think this must require a special projector.
Some drink at the fountain of knowledge. Others just gargle.
I realise this is projector technology - but I wonder whether any of this can be put to use on laptop screens?
I've been frustrated over the last few weeks by not being able to read my laptop's screen when out in the garden on a sunny day. Any thoughts?
Q.
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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!
I came across this on the internet when I was looking for something on RGB lasers a while back, and this just now. Ever since I heard that blue lasers had been invented years ago, I've been waiting for them to be used for projection displays, because there already were green and red ones.
I think they could be better than projectors that used lamps because they could probably last longer. They shouldn't need to be focused either, because a laser can act like a scan line on a surface directly (like an electron gun in a CRT) and achieve greater resolution. However, I'm not sure if that's how these existing RGB laser projectors work.
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.
GNU Info is documentation optimized for machine readability
Black is the new white?
... Breaking news New Development...
XXXX have patented sunglasses that turn black at the first sign of danger.
Some hitchhiker said there eas prior art on this..
For problems, seek only the simplest solution, complexity brings with it more problems.
Why is it that half of the posted stories have grammatical or spelling errors? Not to mention the fact that the submitter didn't even RTFA, thinking that Sony invented a new projector!
Dumbass...
So it blocks out white incandescent or fluorescent bulbs but what about natural light?
This seems to be a common question in the comments here. To represent white, a TV (or projector or monitor or LCD) uses three colors to reproduce all of the colors. It works nicely because our eyes are sensitive to just three specific colors-- red, green, and blue. When you mix bright red, green, and blue light, it looks white. "Real" white, however, is light at ALL frequencies across the spectrum, including lots which we don't have receptors for.
"But if we can't SEE the other colors, why does it matter that the screen BLOCKS those colors?" you might ask... and it's a decent question. The color receptors are not perfectly isolated, but rather a sort of "bell curve" graph of sensitivity centered on a particular color, so there is some response outside the specific RGB wavelengths, although attenuated. Additionally, the rods (as opposed to the cones, which are there for the color) are sensitive to luminance only and used for low-light vision.
So essentially, although we can SEE the ambient light at non-RGB frequencies, we only NEED to see the RGB frequencies from the projector to get a good representation of all the colors, because we only have the three RGB-centered color detectors. And because of this, we can throw away all the excess light, which we can see but does us no good as it is unnecessary to represent the colors in the video.
To recap: Our eyes pick up three colors, but also some other wavelengths. Because our color vision is made of three colors, we only need those three to represent most of what we can see. (Hence RGB video) Because our eyes' "RGB filters" aren't perfect, but rather a gradual curve, we see other frequencies of light. However, we don't need those other frequencies to make an RGB video image, so all they do is make our projector screen too bright to see the pretty colors.
Even shorter: Three sensors in the eyes, three colors on the display. Everything else just gets in the way.
Extra credit: You may have noticed that if our eyes pick up more frequencies than are represented by RGB video, then RGB video must not be able to display all colors. This is absolutely correct-- the color gamut of RGB is smaller than that of the human eye. CMYK printing has a smaller (but slightly different) gamut than RGB, even. So no matter how fancy it is, your digital camera, TV, and even film camera cannot truly represent all the colors we can see. Which is odd to think about-- someday, I'd like somebody to publish a book of colors we can't see in video or print-- but it would have to be in print, so I'm not sure how they'd do it. Custom non-CMYK ink, I guess.
I'm hoping the red and green laser pointers will work on the screen, too. Otherwise it's back to the old fashioned cane!
No encryption can withstand the power of the Lucky Guess.
This patent from Sony gives some detail. To view the images, you need a tiff-viewer plugin.
"It's like, how much more black could this be? and the answer is none. None more black."
"Win treats sysadmins better than users. Mac treats users better than sysadmins. Linux treats everyone like sysadmins."
I use an In Focus projector at home for big events (SuperBowl, World Series), and DVD releases that need a big screen. I borrow it from work. The only thing preventing me from buying one for myself was the fact that it really needs to be dark for regular TV watching. If the prices are competitive, I'll definately buy one of these.
I actually *saw* the screen in question and saw their new 10M pixel projector at InfoComm.
The screen isn't anything new. Its a continuation of high-contrast gray screens that have been on the market for a while now from the likes of Stewart, DaLite, and Draper. For the money, the Stewart Grayhawk/Firehawk is still the best. The Sony image just looked like shit.
The projector is another matter. It was using the same technology as in the Qualia 004 (SXRD IIRC) and it looked ok. There were still problems with the image processor (there were some errors in the image displayed) and cooling. Its only a prototype and there is no final spec sheet, street date, or price set yet. It did look better than the DLP shown by Christie Digital or D-ILA by JVC, or any of the LCDs in the large projector shootout, but it also probably costs 10x as much and isn't in production, unlike the others.
This isn't really a news story folks. It's a PR ploy to try and get Sony's name back into the business AV market.
You're confusing intensity and wavelength. Projectors, monitors etc work by producing three narrow bands of colour (RGB) and varying the intensity of each of the three bands. For a simple example, just play with the RGB colour sliders in any paint program.
I suspect a narrow bandpass filter is exactly what this screen is.
It's like, how much more black could this be? and the answer is none. None more black.
with the exception of the primary bands illuminated by the projector's bulb.
Just to clarify what I meant here, I'm talking about the primary spectral bands. That is, the screen reflects those wavelengths that the projector bulb emits most strongly, and absorbs the rest.
This screen, then, depends on two key assumptions: 1) that the projector bulb's output is concentrated in narrow spectral bands; and 2) the ambient light is not concentrated in those same bands. If I remember correctly, Sony had trouble with one demo setup because assumption #2 failed: the lighting at one show was too close to the projector's bulb output. But for common incandescent lighting I doubt there's an issue.
As for the submitter...yeh, not a projector rather a screen, probably a brain fart while typing and left off "screen". But if you are going to flame, check your own posting and RTFA before lighting yourself on fire.
tm
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As someone previously pointed out, white light is a spread spectrum of wavelengths, but we can make light that appears white to us by only using R, G & B, to which our biological receptors are tuned.
However this raises the question.. if the screen is only reflecting RGB, to which we are sensitive.... why is it not reflecting back what appears to be ambient white light ? (the other side of the question is how can the projector appear to project white light if the screen somehow blocks the combination that would appear as ambient white light)
For outdoor use on a laptop screen, you want a transflective display. I'm quite sure I saw a transmeta laptop with a transflective (rather than backlit) display at one point...
Ah, here it is.
A screen with Nigritude!
Best Buy can have you arrested
Many DLP projectors, especially those targeted to the business sector, have a white section on their color wheel to increase brightness for slide presentations which tend to have a large amount of white. I imagine this screen would reduce the effectiveness of these projectors. Now the amount this reduction would be offset by the increased contrast of the screen, I wouldn't know.
as long as they have a way to draw on the screen like I can with a white board, it's really cool!
... Darkness is spreading!
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How about they project circular-polarized light onto these matched screens, polarized in only a single "random" degree in each frame? Generate the "random" sequence with AES encryption, sync the projector and glasses sets like OTP cards, and the viewer can view a giant "black" monitor in public, yet in secret. Mount retinal biometric scanners in the glasses, encode retinaprint hashes in the display data, and you can send video projections across the world, for public display, for only a specified private audience.
--
make install -not war
*giggle*... silly man...
For the sake of *your* sanity, we can tiptoe around the truth, pretending the world actually is as it merely apppears to our human perceptions. When the kids leave the room, though, the adults will continue to engage reality itself, regardless of how central humans might become to the situation. While you're enjoying your milk and cookies, chew on this: the Sun, not the Earth, is the center of our Solar System. And those Christmas presents come from the mall, not Santa, who's really an unemployed lifeguard.
--
make install -not war
Even given that we've already established that I likely don't know how long a meter actually is, wouldn't a 3m x ~1 2/3+m 'high quality picture' be significantly more incredible [?credibly incredible?]?
Oh wait, most rips/cams/telesyncs are in 3:2
My bad, .torrent on...
While this screen sounds very cool, people with very bright projectors have been projecting on "black" surfaces, even black velvet, for a long time. It results in amazing colors and high apparent contrast _if_ you have an extremely bright lamp to overcome the absorption.
I, on the other hand, took the opposite approach-- a $50 screen made of plain 300 count white bedsheet (king size) stretched tight over a thin wood frame. Better than any $500 screen I've seen, but I'd love to see this new one in action.
Everything material reflects some radiation, therefore "black" is only theoretical, or a manner of speaking: relative or perceived. When you call *anything* black, you're deceiving yourself. In this case, given the importance of the relative darkness of the screen in ambient versus projected light, it is more accurate to say the screen "appears black" in ambient light, but "appears colored" in projected light.
--
make install -not war
But seriously it would only seem like a 24" penis on a 160" screen if you've met too many men on the internet... :)
A 160" screen is probably about 6.5' tall, and you usually see about 4 verticle feet of bang-age, so it would only seem like maybe 12"...
No, no, I'm not a Karma whore...[16" if your watching genetic frea, erm, gifted 'actors'...]
This could be a huge boon for the movie industry, too. By replacing the incandescent light source with some lasers on those frequencies, they'd be able to project onto a similar high-contrast screen.
...a circuit to limit the current inrush when you turn it on. If you do that, then you can turn it on/off frequently and cause little damage to it.
Actually that would be idiotic.
Consider:
The relative inefficiency of the fluorescence process.
The ongoing dimming of the fluorescence due to bleaching of the fluorophores.
The extra cost of using optics that high UV transmission.
The fact that UV damages DNA and can cause cancer.
The expense of a system than can excite multiple fluorophores of different colors (or were you thinking of a monochrome system?)
Looks like you have really thought through this "fluorescence projector" project.
-w
"they can be generated by any number of combinations of different frequencies"
Indeed, and objects reflecting identical "coloured" light can appear different colours to an observer based on the other colours around them.
The colour perceived is determined by the wavelength of the light falling on an object, the nature of the reflecting surface, and often forgotten but most important of all, the human brain.
For example, sitting in bed reading a book at night. What colour is the paper it's printed on. White? You're probably shining an incandescent light onto it. That light is very very orange compared to daylight, yet the page appears white. The brain has picked the brightest object in the scene, regardless of hue, and called that white.
http://www.lusoscreen.com/eng/index.htm
Indeed "white color" consists of photons of various "colors". The idea here is that a color like, say yellow, is absorbed by the screen. Normally the green ambient photon which would excite your red and green receptors in your eye will be absorbed. However, the yellow pixel formed by the projector will consist of red and green photons which are not absorbed by the screen. So you see the yellow of the projector and not the yellow of the ambient light. The same holds for a cyan ambient photon versus a green-blue (=cyan) pixel of the projector. Of course you're not getting all the ambient light out with this system but the narrower the pass bands the better the effect. I think the system is ingenius.
If the screen is black when off, this technology isn't needed.
The black BMW I had the misfortune of following the other day positively glinted in the midday sun.
And I can see my multicoloured reflection in a red car on a sunny day, but that doesn't make the car any less red.
In fact, I'd say that the light that is being *reflected* off the surface says nothing about the colour at all, because it isn't interacting with the material. Hence your specular highlight on a shiny red ball, car, whatever.
I guess the car has the added complexity of different layers of paint, and I'm certainly not an expert in this area, but I'd guess the principle holds.
"Slashdot - News and Chat Sites Deviant". (Click "homepage" link above for details).
I RTFA, and followed the link, but didn't see the details mentioned.
I suspect that the screen will be required to match the bandpass of the dichroic filter which are placed in front of the projector lamp. (remember: bulbs are what you plant in the ground) If your projector does not use the same filter frequencies as the screen is designed to reflect, you will end up with color shifts in your output image (not enough red/green/blue, depending on your particular projecors setup).
The color of the screen in ambient light will depend on the color rendition of the lighting. Fluorescent lighting could really screw these things up, and you might see a red, green, or blue colored screen depending on the phosphor wavelengths. There might even be a whole new class of fl. lighting which is "black screen safe" and has dropoutsnear the frequencies of interest. The screens will also shift color depending on whether you have low color temperature incandescent or hogh color temperature incandescent lighting. One can hope that the bandpass of the screen is small enough that the brigtness of this background color is not apparent to the observer.
Is it just my observation, or are there way too many stupid people in the world?
I RTFA, and followed the link, but didn't see the details mentioned.
That's fair, my information comes from sources other than the article. There have been quite a few threads on this over at AVS Forum, including first-hand reports from people who saw it at Infocomm.
I suspect that the screen will be required to match the bandpass of the dichroic filter which are placed in front of the projector lamp.
Actually, no, the screen will have to be far more restrictive than the dichroics used in projectors, which have nice wide bandpass characteristics. The screen, in contrast, is tuned rather precisely to the spikes present in common projector bulb spectra.
If your projector does not use the same filter frequencies as the screen is designed to reflect, you will end up with color shifts in your output image (not enough red/green/blue, depending on your particular projecors setup).
You are absolutely correct! This screen must actually be designed for the specific type of bulb used. I could be wrong, but I believe the screen being demoed now is designed for a Xenon bulb. More common and less expensive are UHP bulbs; they would need to design a different screen material for this.
Also note that small color shifts induced by this technique can be corrected for by calibration. This can affect the projector's contrast ratio slightly (in either direction, actually) but it shouldn't be too severe.
Fluorescent lighting could really screw these things up, and you might see a red, green, or blue colored screen depending on the phosphor wavelengths.
Right. This may have been the problem that Sony was having with one of the demo sites.
How can the screen know which photons came from the projector and which came from the incandescent lamp? The lamp is spewing all wavelengths, including whatever frequencies the projector is spewing. So how does this help?
"A great democracy must be progressive or it will soon cease to be a great democracy." --Theodore Roosevelt
Please read more carefully. My original post said this several times, quite clearly:
"The color receptors are not perfectly isolated, but rather a sort of "bell curve" graph of sensitivity centered on a particular color, so there is some response outside the specific RGB wavelengths, although attenuated."
and here:
"So essentially, although we can SEE the ambient light at non-RGB frequencies, we only NEED to see the RGB frequencies from the projector to get a good representation of all the colors"
and here:
"Our eyes pick up three colors, but also some other wavelengths"
and here:
"Because our eyes' "RGB filters" aren't perfect, but rather a gradual curve, we see other frequencies of light."
and here:
"You may have noticed that if our eyes pick up more frequencies than are represented by RGB video, then RGB video must not be able to display all colors. This is absolutely correct-- the color gamut of RGB is smaller than that of the human eye."
I apologize if I didn't repeat it enough times for it to sink in for you, but I was quite clear that I was simplifying things in that example, and spent a whole paragraph using the fact you state (that our eyes see all frequencies rather than just RGB) to explain WHY it's necessary to reject the non-RGB light from the screen. It's like you didn't even read the post-- but I suppose this is slashdot.
FIVE TIMES, man. I said it FIVE TIMES.
What a good idea. In retrospect, it's obvious. I wish I had thought of it.
Except: fluorescent bulbs also emit RGB, in order to make white light. While it's likely not exactly the same R, G, and B as the projector pixels, I'll assume the bandwidth for reflection of the screen is fairly wide to accomodate as many different projectors as possible.
Most boardrooms and classrooms use fluorescent lighting, which should reflect.
It should still be better than what we have now, but something to consider.
Getting diabetes AND salmonella would be a bad weekend.
> I got a few more. :-)
> DAT, Mini-disc, betamax.
I'll give you Betamax. But since I have a Sharp Mini-disc I'd dispute the MD. And I know other companies make DAT, but nobody cares about it because of the copy restriction tech Congress forced on it.
Other companies make Memory Stick, but again, who cares? It was a dumb idea to try introducing yet another format, especially one with a 128MB memory limit!
So yes, they will almost certainly license this stuff.... assuming THEY aren't just licensing it themselves.
Democrat delenda est
"Emphasis added," indeed. Sorry if the wording was bad there-- I should have said "Our eyes have three types of color receptors" not "our eyes pick up three colors." Both are, however, true. Color does not equal frequency. We see millions of frequencies, but only three colors. Light falling into range for one of the receptor types, no matter what frequency, produces the same depolarization response from the receptor. End result? There are only three colors received by the brain from the eye. And "Some" was a poor choice, too. Sure, "millions" are "some," and the visible spectrum is a tiny part of the EM spectrum, but "infinitely many" is more descriptively accurate.
I know what misleading means. Are there three types of receptors in your eyes? Yes. Are they the reason we perceive color the way we do? Yes. Do they overlap significantly? Yes. I have looked at the graphs extensively. I have written colorspace conversion code.
I tried to be clear. It wasn't good enough for you, so I tender my humble apology.
Two of the peaks do overlap quite heavily. The third is significantly more isolated. If I simplified too much for you, I'm sorry. The whole point is that because there are three receptors, we can represent colors with just three colors chosen to fall into range for each of them, and that in addition to this-- because the receptors are not perfect single-frequency detectors, we also see the whole range of frequencies. This was my attempt to show 1. why RGB color works and 2. why it works imperfectly enough for ambient light to be an issue on a projector screen.
For the record, I don't think I was misleading. But I will try to be clear enough to appease even random nitpicking slashdotters in the future. While a few of my statements may seem misleading to you by themselves, I think that my post as a whole is quite clear.
Just in case you've misunderstood me... Definition: nitpicking
Sony is also developing ultra-flat screen TVs based on carbon nanotube technology that are supposed to be thinner (3/4 inch) and substantially cheaper than (3-inch thick) plasma flat screen TVs. These will be in the 50-inch range. I can't imagine wanting a bigger television in a house, let alone a projector hanging from the ceiling. But apparently Sony thinks there's a home market for humongous projector systems too.
For just a second, I thought, "Impossible!", but then I really started to think about it. If your projector uses narrow enough band pass filters for R, G, and B (and the narrower the better for color reproduction), then you could probably increase contrast pretty well by eliminating all ambient light outside of those bands.
A black body source (like an incandescent light bulb) puts out a continuous spectrum of light, and a lot of it would be outside of those three relatively narrow bands. Flourescent lights have a very different spectrum, but might work about as well.
Of course, if you use red, green, and blue LEDs to illuminate your room, the screen will reflect almost all of the ambient light. This is pretty uncommon, but there's a dance club here that uses such a system so that they can arbitrarily vary the color and brightness of the ambient light.
-podom
We're wanted men. I have the death sentence in 12 systems!