Slashdot Mirror
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."
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
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.
I have a 92 inch screen in a 13'x12' room at first people thought it would look riduclious but when you put the screen up the room looks a lot bigger and cleaner espcially since there isn't a big (32 inch) TV taking up space like there used to be. Plus I can move the projector and screen by myself the 32 incher is worlds heavier.
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!
This is kind of like someone patenting a table with 4 legs. Then you patent a table with 4 legs made from maple. You still need access to the first patent, but you can prevent anyone else from making one from maple.
IANAL
The article says that it works with normal projectors.
mbbac
They don't go into the physics. If, as you say, it only reflects certain frequencise, it can approach black - it just depends upon what you define as the cutoff albedo for black: 10%? 2%? 0.1%?
On the other hand, it might be an angle thing. It absorbs light coming from all angles except a special one, and reflects spherically light coming from that angle. In which case, from all other angles it is black. You could do that by having a set of angled tubes with black exteriors pointing at the projector.
Consciousness is an illusion caused by an excess of self consciousness.
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've gone through at least 6 InFocus projectors in the last 1.5 years due mainly to bulb failure.
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.
Do not look at laser with remaining good eye.
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 rather than LCD Projectors. 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 better suited to enhance a DLP projection. DLPs are supposed to be popular for home theaters.
"The newest and latest technology results in the most beautiful image you will ever see*!
(*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.
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
True white light (like what you get from the sun) consists of an equal spread of energy across all frequencies. You can make light that _appears_ white (to our eyes) by mixing a small number of different colours (for example, red, green and blue). See my other post.
http://blog.nexusuk.org
No.
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 (approximately) the same frequencies that our eyes are tuned to. This means that something like 90% of all the other frequencies that are in the white ambient light are absorbed, while almost all of the light from the projector is reflected.
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.
No, this will only work with a digital projector. The screen only reflects pure blue, pure green, and pure red. Any other color gets absorbed. A digital projector will work fine - any analog projector will look just like someone projected it on to a black screen, unless someone comes up with a film that only projects the same three wavelengths.
W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
Pigments are based on light. Cyan, magenta, and yellow are the three primary pigment colors only because they represent the abscence of one of the primary light colors.
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.
Well, sorta. The clip you provided doesn't contradict the correct description given in the grandparent post, at least the part you quote.
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.
Never confuse volume with power.
I got a few more.
:-)
DAT, Mini-disc, betamax.
Will they never learn?
That's probably part of the technology they used, mentioned in a previous story about "Invisible Cloaks, Translucent Walls". Otherwise, I don't see how they would be able to project an image on a material without the projection appearing around it.
yes, that's why they turn the lights off in a cinema.
/brain system makes colors and shades from the whole of what it's looking at. really, the frequency/intensity of the light from a particular region is only a very rough predictor of what color/brightness you will see.
if you've ever seen projectors in rooms with significant ambient light, they look fuzzy and have no deep blacks. it is however remarkable how the eye
and of course, if it looks black it is black.
This patent from Sony gives some detail. To view the images, you need a tiff-viewer plugin.
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.
http://www.mvis.com/
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.
Okay, so what you're saying is that you have never used the word black to describe a color before, hmm? Because the grandparent's point was that there are no substances that absorb all light in the real world. Yes, hypothetically black is the absence of light, and yes, his example with the car was inaccurate, but we call things black that reflect loads of color, whether they're matte or shiny.
Therefore, the screen will appear to humans to be black, just like the other black objects in the world.
An expression or utterance marked by a deliberate contrast between apparent and intended meaning.
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.
The bulbs on all of these projectors have an estimated lifespan of 1500-2500 hours. That's many, many years the way I watch TV. Unfortunately, the bulbs are expensive and not covered by the warranty-- even if the problem is bulb destruction!
In other words, you got a dud. Just like I did. You need to get it repaired, which will probably cost less than a single bulb, even if they gut it and replace it.
Human visual acuity is about 1 minute of angle, meaning you need a screen to subtend 32x18 degrees to visually resolve 1080 line HD.
To maintain a sense of immersion, THX suggests a 36 degree subtended field of vision for the farthest seat in the theater. Home theater enthusiasts find that in the absence of projection artifacts, the best seating is at about 1.5 screen widths (about 37 degrees)
This translates into a diagonal screen measure 2/3 to 3/4 your seating distance. At modest sized living room dimensions and beyond (10' to screen) this is impossible to achieve without a 2 piece projection setup (79 - 90" diagonal required).
A 32" TV a few feet away on your coffee table would work but have a bigger impact on the decor than a wall mounted or retractable screen.
We're talking about the some of the same mechanisms that cause you to be temporarily blinded when you walk from a light room to a dark one. Your eyes have to adjust to the new light intensities; and, until then, everything appears "black".
You're correct in saying that if an object really is black in color, it's not reflecting or producing any light. Something may appear black from one angle, because the surface is selective about what angles it will reflect light. Some automotive paints take advantage of this concept to cause the color to shift depending on what angle you're looking at the surface. (I use this example, because you may have seen it IRL). They do this by mixing small reflective flakes into the paint, and when they spray the paint on, they electrostatically charge the car body. This causes the flakes to stand on edge. When you look at the surface straight on, you see the base-coat color. When you look at the surface from an angle, you see the flake color. I suspect the manufacture of the projector is doing something similar.