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Mobile Phone Projectors "Will Launch This Year"
An anonymous reader writes "Mobile phones with built-in mini projectors will launch later this year, according to 3M, which gave PC Pro a hands-on demonstration of the technology at CES 2008. The projector has a brightness of around 8-10 lumens, and is capable of displaying an image of up to 50 in., although 3M's spokesperson Greg Roberts told us that, with perfect lighting conditions, it's possible to squeeze a 60-in. screen out of the projector."
WTF? 50inch screen with only 10 lumin is going to be SHITTY.
If you mod me down, I will become more powerful than you can imagine....
This is only going to lead to millions of college students slipping a 50" cock into the professor's lecture while he isn't looking.
... but this is not the same as this one http://hardware.slashdot.org/article.pl?sid=08/01/03/0418221. This one is led based and seems to be smaller but the PicoP one is laser based and images seems to be better. That is the one I want on a mobile phone. OTOH I don't want these on my mobile phone...
"A real computer in a pocket."
Are you sure you're not just happy to see me?
Being in the film industry, I work in footcandles usually and not lumens, but If I recall correctly the correlation between them is close (I'm not a cinematographer, so lighting is secondary to my normal job function). A 'birthday cake candle' in a pitch black room, will produce 1 foot candle of light at-- wait for it.. 1 foot. If you put a 1-foot-square surface (like a 12" x 12" piece of paper) 1 foot away from that candle, it will be hit with "1 lumen"
;). If they can increase the light output significantly, it might be useful for something other than showing someone really low brightness web pages shined onto a piece of whitepaper 10" away while in a darkened room.
A 'normal' candle produces about 15 lumens. Incandescent bulbs (normal lightbulbs) produce about 15-18 lumens *PER WATT*. So this projector is roughly equivalent to
Now, there are claims of a 50" projection (diagonal, I assume) from this-- no specification as to how far from the projection source the 'screen' is, but light works on the inverse square law-- basically, as you double the distance from a given light source, you get a square root of intensity. So if this sucker threw 10FC at 1 foot, at 2 feet that intensity has dropped to 3.2. At 4 feet, 1.8. So if that 50" screen requires you to be 8 feet back.. forget about it.
Overall, this sounds like a cool little geek gadget, but as other posters have said, probably just another example of cellphones trying to do too much (too poorly
Apologies if I screwed up any of my tutorial, as I said, I don't paint directly with light, I just admire the guys who do.
I am Jack's complete lack of surprise.
Why a cellphone? so that everyone can see who's calling me?
Wait, you mean, you mainly use your cellphone to give/receive phone calls? lol! 1998 just called, they want you back.
You just got troll'd!
This is about selling phones, not about producing quality images (that might come in five years or so).
Remember polyphonic ringtones? Were they "quality" music? Nope, but we all secretly wanted them.
The gadget power of having a phone-projector is orders of magnitude more than a polyphonic ringtone. This thing will sell millions no matter how bad the image quality is.
No sig today...
Now imagine in a few years where your display surface might just be a cheap light screen with a simple support to hold it at different angles. The computer can be almost any shape that suits, perhaps with a fold out keyboard. You can have a big screen on your desk, a small clip on screen that you use on the train. Perhaps the computer has a wireless dongle that includes the display driver, perhaps it's built in, perhaps both.
Using a curved screen might involve no more than an adjustable object in the optical path to deal with the pincushion distortion - use of lasers means focus at virtually any distance.
Microsoft has built up a huge business based solely on the mouse, monitor,keyboard model. Apple has started to move away from it. This is a little gadget which could reshape the desktop computer industry. It shouldn't be underestimated.
From scarped cliff or quarried stone she cries "A thousand types are gone, I care for nothing, no not one."
What counts in a projector is contrast (e.g. how much brighter is a "white" projected spot as opposed to a "black" projected spot).
Obviously this depends on ambient light, since the darkest part of the screen (i.e. the "black spot") is illuminated only by ambient light (assuming that 'black' in the projector means 'no light passes').
Illuminance is measured in Lux (lx). Lux is defined as follows.
Lux = Lumen / m^2.
Now, a "good" contrast is 10-15, i.e. a white spot will be illuminated with 10-15 times the lx a black spot is.
Normal ambient light is highly variable; a typical table in a lecture room should be illuminated with about 500-1000 lx; the ambient light on your typical screen in an illuminated room (i.e. not a theatre) will be illuminated with maybe 100-500 lx.
So in order to obtain a proper picture a projector should be able to do at least 1000 lx. Comparison: a typical home cinema beamer has about 2000 lumen and projects an area of about 2x1.12m; this means 2000 lumen / 2.24 m^2 = ~900 lx. And guess what, the picture is just fine when the room is "quite dark" and pretty washed out when it is illuminated.
With the claimed 8-10 lumen - let's assume 10 - you can thus illuminate
10 lumen / 1000 lx = 0.01 m^2
Assuming a picture format of 16:9, that's a picture size of
sqrt(0.01 m^2 / (16 * 9)) * 16 = 0.13 m width
sqrt(0.01 m^2 / (16 * 9)) * 9 = 0.075 m height
An incredible 13 cm x 7.5 cm! (5" x 3" for Americans).
That's a diagonal of 5.8". Makes sense since a 2000 lumen projector is 200 times more powerful and accordingly projects an image with sqrt(200) = ~14 times the diagonal.
Except in the darkest of situations, you will *never* have an usable 50 inch image with a lousy 10 lumen.