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Philips Develops Fluid Lenses
Lars T. writes "Digital Photography Review has a short report indicating: 'Philips Research at the CeBIT exhibition is demonstrating a unique variable-focus lens system that has no mechanical moving parts. Suited to a wide range of optical imaging applications, including digital cameras.' Here is Philips' press release and the Heise News article (in German) where I first heard about it. The latter also mentions that Philips has recently used the same electrowetting effect in an 'ePaper' display prototype."
"Suited to a wide range of optical imaging applications, including digital cameras." I take this to mean that it is not ready for precision applications and that it may not be. either way, this will take time to get any better
Choosing the lesser of two evils is a choice for evil.
Would it be possible to adapt this type of lens to eyewear by enlarging the size? Instead of using bifocals or trifocals, you might be able to have just one lens that changes shape according to a microcontroller, which is then hooked to either a button, or perhaps tapped into a nerve, which can then be trained to send the appropriate signals.
There was an article in New Scientist a few weeks ago about a lense that changed it's focus in response to an electric current, iirc.
It was made of some plastic and I think the current changed the density of the plastic at some point in the structure in order to change the focus.
Of course, the aim was the same: "Make a lense without moving parts" - these guys must have developed a better solution because the Lense was very poor in the NS article.
Simon.
Look at their demonstration photo and ask yourself. Lens the size of the tip of its developer's finger?
Or developer with a finger...the size of a camera's lens!
You be the judge.
This is the last time I fall for the grotesquely-oversized-finger demonstration trick. Fool me once, shame on you; fool me twice...
Philips' Fluid Lenses
Wednesday, 3 March 2004 21:40 GMT
Philips Research at the CeBIT exhibition is demonstrating a unique variable-focus lens system that has no mechanical moving parts. Suited to a wide range of optical imaging applications, including digital cameras. Philips' FluidFocus system mimics the action of the human eye using a fluid lens that alters its focal length by changing its shape. The new lens, which lends itself to high volume manufacturing, overcomes the fixed-focus disadvantages of many of today's low-cost imaging systems.
Press Release:
Philips' Fluid Lenses Bring Things into Focus
At this year's CeBIT Exhibition in Hannover Germany, Philips Research is demonstrating a unique variable-focus lens system that has no mechanical moving parts. Suited to a wide range of optical imaging applications, including such things as digital cameras, camera phones, endoscopes, home security systems and optical storage drives, Philips' FluidFocus system mimics the action of the human eye using a fluid lens that alters its focal length by changing its shape. The new lens, which lends itself to high volume manufacturing, overcomes the fixed-focus disadvantages of many of today's low-cost imaging systems.
The Philips FluidFocus lens consists of two immiscible (non-mixing) fluids of different refractive index (optical properties), one an electrically conducting aqueous solution and the other an electrically non-conducting oil, contained in a short tube with transparent end caps. The internal surfaces of the tube wall and one of its end caps are coated with a hydrophobic (water-repellent) coating that causes the aqueous solution to form itself into a hemispherical mass at the opposite end of the tube, where it acts as a spherically curved lens.
The shape of the lens is adjusted by applying an electric field across the hydrophobic coating such that it becomes less hydrophobic - a process called 'electrowetting' that results from an electrically induced change in surface-tension. As a result of this change in surface-tension the aqueous solution begins to wet the sidewalls of the tube, altering the radius of curvature of the meniscus between the two fluids and hence the focal length of the lens. By increasing the applied electric field the surface of the initially convex lens can be made completely flat (no lens effect) or even concave. As a result it is possible to implement lenses that transition smoothly from being convergent to divergent and back again.
In the FluidFocus technology demonstrator being exhibited by Philips Research at CeBIT 2004, the fluid lens measures a mere 3 mm in diameter by 2.2 mm in length, making it easy to incorporate into miniature optical pathways. The focal range provided by the demonstrator extends from 5 cm to infinity and it is extremely fast: switching over the full focal range is obtained in less than 10 ms. Controlled by a dc voltage and presenting a capacitive load, the lens consumes virtually zero power, which for battery powered portable applications gives it a real advantage. The durability of the lens is also very high, Philips having already tested the lens with over 1 million focusing operations without loss of optical performance. It also has the potential to be both shock resistant and capable of operating over a wide temperature range, suiting it for mobile applications. Its construction is regarded as compatible with high-volume manufacturing techniques.
(A) Schematic cross section of the FluidFocus lens principle. (B) When a voltage is applied, charges accumulate in the glass wall electrode and opposite charges collect near the solid/liquid interface in the conducting liquid. The resulting electrostatic force lowers the solid/liquid interfacial tension and with that the contact angle q and hence the focal distance of the lens. (C) to (E) Shapes of a 6-mm diameter lens taken at different applied voltages.
Prototype FluidFocus lenses
Photos courtesy of Philips
Just like the oil lenses in Dune
I dont know about scaling it up. The article is short on details which relate much to eyewear. Eyeglasses correct a huge range of flaws in eyes; by far not the least of which is astigmatism, (wildly popular) which is when your cornea is not curved the same in all axis. (For example, your eyeglasses correction may need to be different vertically than horizontally.)
Astigmatism isn't going to lend well to this, would be my guess, but who knows maybe those wizards can make assymetrical fluid shapes.
Secondly, the size.. why make it big? Make it small like contacts (your eyes dialate only to 5 or 6 mm as an adult.) And put it close. Bizarre tiny eyeglasses is the ticket.
Frank Herbert had a similar idea in Dune: he referred to a pair of binoculars having "oil lenses" that were shaped electrically.
Just another instance of science fiction authors' jobs getting harder, I guess.
ever mix a cup of oil and water? now - there is always a surface between the oil and water since they don't mix, but now, shake the darn thing up and a lot of "oil bubbles" will appear in the watery side, and vice versa. I am sure it will not be good for the optical qualities!
I also noticed that their prototype is extremely small - wouldn't a bigger one be subject to gravitational pull / buoyancy (in respect to eachother) of the liquids depending on lens orientation - and therefore causing a distortion to the optical surface?
My life in the land of the rising sun.
I remember that fluid lenses have been used by holographers for a long time, because they can be of quite high quality even with large diameter. Vari*lite also uses fluid lenses in some of their intelligent lighting fixtures.
The News here is that the Philips lens can be focused by an electric field with no part moving other then the lens. The size of their prototype is tiny; IMHO they need at least to triple the size of it to make it useful for digital cameras.
-- www.linux-laser.org - Open Source Laser Show Software for Linux
Could this be a step for manufacturing artificial eyes? Being able to actually zoom in with my eyes would be cool, and if it has NekkidVision(TM), it would be even better :)
Founder of Mirror Moon - Tsukihime Game Trans
To me it seems that using such a lense would be bad news in a nonstable environment. E.g. a bumpy car ride.. Any thoughts on this?
Depends on which fluid has the lower refraction index. I.e. either the upper-fluid in the diagram can be regarded as the lens, in which case the lines are drawn correctly, or the lower fluid, in which case you are right.
Depends on the properties of the liquids. On the left, the blue liquid is convex and the brown concanve, and on the right the blue is concave and the brow convex.
So, if light is faster in the blue liquid than in the brown one, the light-rays would move as described.
A lone researcher did it to make cheap bifocals a few years back. It is an extremely inexpensive way to provide a "one size fits all" pair of glasses for everyone who needs them. No custom lenswork needed - just pump liquid in or out :)
Is electrowetting wetting the bed with the Electric Blanket on?
Cheers
Stor
"Yeah well there's a lot of stuff that should be, but isn't"
For single lens cameras, no coatings are not that big a problem.
For multiple lens cameras, it can lead to a lot of chromatic aberations.
If these oil lenses can accept liquid optical layers, look out Karl Zeiss.
I guess you where sleeping your way through the optics lectures: These lenses could definitely work. If you look at the picture
you see that there are two fluids: brown one on top and a blue one on the bottom. If you remember Snell's law (ray bends towards the normal in the denser medium), you can conclude from the picture that the 'brown' fluid has a higher refractive index than the 'blue' fluid. The left picture thus resembles a hollow/concave/negative lens and the right picture resembles a convex/positive lens. Of these the positive (on the right) can be used to form a real image (one you can capture on a CCD or a retina), whereas the negative only forms a virtual image.
A colleague of mine did his internship at the group that invented these and my boss still works part-time at Philips.
karma police: arrest this man, he talks in maths; he buzzes like a fridge, he's like a detuned radio. [radiohead]
Everyone keeps saying this. I looked at the diagram, and at least one part of the lens moves. That's a moving part, folks. Stop saying it "has no moving parts".
Now, here are some predictions:
Please help metamoderate.
I claim prior art as I have had two of them since 1969. Seriously, one squashy lens (of only moderate performance) with a clever image processing system behind it - as in the eye/brain setup - is probably the way to go for digital applications. Computing power is a lot cheaper than Schott optical glass!
When I am king, you will be first against the wall.
It's "lens", plural "lenses". I don't care what your dictionary says.
Ydco co
Fluidic adaptive lenses have been around for several years. I recall many years ago I read about a tech Academy Award for someone developing a fluidic lens for 70mm movie cameras, it was rather primitive, just a blob of transparent gel sandwiched between two plates of optical glass that could be moved by motors, but he got there first. I can't find a citation since the AMPAS database doesn't search on tech awards.
This is nothing new. Run enough current through a person and you'll see 'electrowetting' in action! 'Electrosoiling', too.
You must think in Russian.
A neat and easy way to form a parabola is taking a liquid and spinning it. I've formed parabolic mirrors on my turn table just using ordinary epoxy and spray on silver paint. Not to say this isn't cool, but there seems to be an easier means to achieve a variable focus lens via spinning a clear liquid such as water, or perhaps even a reflective liquid like mercury.
There is no sanctuary. There is no sanctuary. SHUT UP! There is no shut up. There is no shut up.
I am a scuba diver and I always wanted to have a small camera when i dive. The ones you can buy now are quite expensive and fragile. Most models use a underwater housing for a standard digital camera that is quite fragile. There is a rubber O-ring around the enclosure to keep the thing water tight. But sometimes you get some dirt on the rubber and the camera leaks when you are 30m below the surface, spoiling your camera.
So I have always dreamt of a hermetically closed camera. You could fill it with a liquid (oil?) to reduce the pressure stress on the enclosing. (This is what current scuba computers do.) By using a digital camera, you don't have to open the camera to access the film. The problem so far has been how to construct a zoom lens since these vary in volume. This kind of lens seems to fix that problem!
)9TSS
this is probably the most boring sig in the world
A man designed some specs that used this technology in order to provide clear sight to the poor masses in Africa. All he did was have two syringes - one for each lens- and he adjusted the lens by pumping in/sucing out liquid as the person looked at some images, then he unplugged the syringes and a valve kept the liquid in and the glasses set to the same level. It's kind of a one-pair-fits-all system where the vast majority of people that needed glasses could use this one system. They sure weren't hot to look at, but no-one gave a crap because people aren't so vain over there! This certainly isn't a new technology.
http://www.frenchgeek.com/
How fast can you change focus? If you can change faster than the time it takes to take a picture, you could actually use different focus for the same picture. Each pixel could look on the values of a few neighbour pixels to find out when the picture is sharpest in this region and save only the pixel value from that time. Information about the actual focus used could be saved in the alpha channel. Imagine a picture of an object 10cm from you where both that object and the background is sharp.
Do you care about the security of your wireless mouse?
I can't comment on the technology in the article, but I can say this, Philips NL are the nicest company I have ever worked for. If you are ever considering a job
at this company and wonder about their corporate culture know this... Philips combine technical excellence with an easy going attitude that encourages invention and freethinking.
They pay good wages and have excellent facilities. I was at their Eindhoven unit in 1995
for about 6 months. Even though I was an outsider brought in on consultancy, younger than my work peers, and a foreigner from England, I was treated with respect from day 1 until I left. The Dutch are very friendly, but most importantly straight talking people. I never had to endure hidden agendas and bullshit that pervades US and some UK companies. They are very open and honest. After the first night out drinking beers, I knew how the much people I worked with earned, about their families, houses, lifestyles and ambitions. One of the family straight away. Work was intense but enjoyable, you had the feeling of working somewhere that makes a difference doing proper frontier research. I hope its still like that. I was sad to go. Philips invented the CD amongst other things. They also sponser the PSV Eindhoven football team.
Big up Philips.
This is way cool...
This makes a lot of things possible that would have been prohibitively expensive, mechanically improbable, or optically restrictive. A small lense with fast focusing, which is high quality, shock resistent (this would depend on oil viscosity and lenses size), and remarkably cheap to manufacture in large numbers would revolutionize;
* Robotic vision,
* Consumer electronics,
* Security and Research imaging,
* Medical Imaging, and Lense Replacement.
You could cover a robot with cheap eagle-eye imaging devices, create a central imaging system that sews all the images together to produce an ultra-highres 360 degree whole world views. This machine would literally have eyes in the back of it's head. Give the critter broad spectrum vision, and spectrospopic analysis, and this robot could be used for anything from public safety, to mineral evaluation for mining. If you're going to buy a robot, make sure it has "Phillip's whole world vision(tm)".
This makes disposable highres digital cameras and camcorders totally practical. It makes low end devices possible, products for tens of dollars or less, that have the optical features you would expect to find in products that now cost hundreds of dollars. This is especially true if you combine glass element(s) to the lens. You get the power and optical benefit of a glass front lense, a large optical aperture for light gathering, with simple focus and zooming capabilities provided by liquid lenses. A superior lense with a huge list of advantages. Sign me up!
Now that you have a high quality cameras selling for $10.00, you can put them anywhere and everywhere. Imaging for a whole host of purposes becomes ubiquitous (orders of magnitude more prevalent than today.)
Beside giving medical devices better vision, replacing the lense in the human eye, with one that is for all intents and purposes perfect, would be a godsend to millions of people with cataracts, degenerative lense desease, and missing or injured lenses. In the end, this might become so common place, that when you get to that age where folks noadays begin buying multifocal glasses, our descendents will simply get a super lense implant, and have bionic visual abilities that we can only imagine. Would you trade your eyes in for one's that gave you superwide angle and telescopic capabilities? Oh, and for those folks with astigmatic trouble, one could circle the inside of the lense barrel with panels, and apply differing voltages to the panels so as to create a lense shape consistent with any corneal asymetries. This would be the hot new product among the rich and graying!
Genda
Aberations aside, its always cool to se new technology emerge in the field of visual optics. The field of optical science is realy realy old and still there are many more things to be discovered.
This is my sig, show me yours
OIL LENS. Force-field-enclosed hufu oil, used principally in telescopes. Oil lenses -- so accurate that they have yet to be surpassed, eight millenia after their invention -- share with many other enduring pieces of technology an elegant simplicity. Each lens is made up of a layer of hufuf oil (varying in thickness from .5 mm to 1.0 mm) held in static tension by an enclosing forcefield, and is places within a viewing tube as part of a magnifying or other light-manipulating system. Because of the extremely responsive nature of the enclosing force field, the oil layer can be adusted within microns of a desired setting. No other type of lens element approaches such accuracy.
in 7687, Marcus Vander, an Ixian Field Technician (Class 3) was experminenting with the effects of various force fields on compressed fluids. He had chosen hufuf oil (a derivitave of the hufuf plant, a native growth of Ecaz noted chiefly for its oil-filled seed pods) because of its viscosity and near-perfect transparency.
Vander wished to develop some means of transporting liquids using a force field as a container, an invention which would undoubtedly have had a wide array of useful applications. What he actually created -- as he discovered when the suspended oil focused a beam of white light onto his lab counter and melted its finish -- was the first oil lens.
The new lenses completely replaced all older, less accurate types within fifteen years of their entry into the marketplace. Their supremacy was threatened only once, in 8176, when a poor harvest of hufuf pods created a shortage of oil. Fortunately, the season following was an exceptionally good one; it was discovered that the hufufu plant adapted very nicely to cultivation on Yorba. The double cultivation has prevented any further shortages.
-- SKYKING, SKYKING, DO NOT ANSWER.
You know the ones, a few lagers and you generally have a better appreciation of the fairer sex.
;-)
There are 10 kinds of people; those who know ternary, those who don't, and those now hunting for a dictionary.
After all, I invented a variant back in '83. NASA should still have copies of some of my drawings.
.
Of course I designed it for different uses (mostly diagnostic) and had a few added features that they didn't implement. Gonna have to look at their patents and take a gander at the claims.
I wonder if I should sue.
What's *really* funny is that from what I know, DoD may already have patented my beastie for use in SDI, with or without NASA permission.
Hmmmmm . . . . .
Rustin
Data is the lever, rigor the fulcrum, brains the force that drives it all.
I take this to mean that it is not ready for precision applications and that it may not be.
Well, duh. Think about the vibration concerns. Any movement not only jiggles the thing but it also takes time for it to settle back down.
Back when I designed a version of this w a a a a y back in the early eighties I was quite paranoid about the issue of how do ya keep the thing from accumulating stuff near the resonant frequencies. I'm not seeing anything in the brief English-language piece about this at all. My puppy allowed for the option of changing focal length by changing ring diameter which, oh btw, made things potentially even worse on that front. On the other hand, IIRC, I made a point of the importance of being willing to switch ring materials to optimize for stuff like ability to dampen vibration.
I wonder if they've figured out yet that when you've got a liquid lens that changes properties by changing electrical charge, you can add impurities to the liquid such that charging the liquid, the liquid will change color. Very precise, very neat, and entirely reversable, at least for as many cycles as they would need for a consumer product.
As I mentioned below, I really *am* gonna have to dig up my old drawings and writeup.
*sigh*
This because I have nothing else to do with my time.
Yeah, right.
Rustin
Data is the lever, rigor the fulcrum, brains the force that drives it all.
I think that's the point--they're targetting small camera applications: mobile phones, PDAs, keychain digital cameras, clandestine surveillance cameras and such.
Prolly not. The real issue is that the smaller the lenses, the more of a role surface tension takes towards creating a uniform surface. Boundary layers between fluids always have a tendency to bow out in one direction or the other. But that "skin" is just half the thickness of one molecule plus it's range of interaction with the surrounding ones. For water, remember your Van Der Waals forces, kids.
In a one centimeter wide tube filled with water, this phenomenon is obvious and dominates the behavior of the interface. In a one *meter* wide tube, everything from little wavelets from vibration (!) to any impurities to, oh, btw GRAVITY[1], will tend to randomize the shape of the interface.
In udda woids, the bigger the surface area, the more random, or at least nonuniform the shape of the "lens".
Getcherself a copy of good ol' Prandtl&Tietjens (Fundamentals of Hydro&Aerodynamics). Your life will never be the same.
[1] It blows my mind that *nobody* on this thread has yet commented on the tendency of gravity to deform such lenses. Gack! Have *any* of you done the thought experiment instead of just believing what you read?
The Phillips device has a second fluid. I would assume in part this is to address that. Betcha that the indices of refraction are very different but the densities are exactly the same.
Rustin
Data is the lever, rigor the fulcrum, brains the force that drives it all.
There are some uses for these that aren't necessarily obvious. For a long time the US Military has been researching ways to protect troops eyes from blinding lasers (Lasers that scan for relflective surfaces like eye-balls which they then pulse with enough energy to damage). One Idea that has repeatedly come up was to give the troop a sort of "blind cockpit" to operate from. This would be acheived by making a pair of goggles with high res screens on the inside and an exterior studded with an array of small, inexpensive cameras. By feeding the data from the cameras through a processor then to the troops veiw, you seperate his/her eyes from the danger. This would also allow the troop to have a sort of HUD overlay as well as easily integrated nightvision (IR receptive CCD's scattered amoung the visible light CCD's).
"Hand me the bullet-shooty-thing and a box of little hurts" -Overheard on a USMC Rifle range
Philips is the inventor of the CD, and plays an important role in the development of DVD and its successors. Now where could somebody use a tiny, focusable lens without moving parts? Multi-layer optical drives, both player and recorder is certainly a valid answer.
Lars T.
To the guy who modded me down from perfect to terrible Karma - Apple haters still suck
A French company called Varioptic has developed such a lens and is close to the mass production phase.
Plans are to make a Liquid Mirror Telescope (different tech: spinning Mercury) bigger than the Mt. Palomar. I think that the electronic wetting tech will probably show up in hihg-end consumer telescope eyepieces. Current variable eyepieces use mechanical components to vary the gap between multiple elements. This should be easier to manufacture. R.
Headlight beams are entirely too coarse; I'd love to be able to dial in a perfect throw, depending on road and conditions. Lenses like this would be one good component of the perfect headlight system. Other parts would be intelligent swiveling mechanisms (left and right as well as up and down) and colored gels (or a chemical layer with a variable color) to best match the day and the driver's vision ... but I digress :)
timothy
jrnl: http://tinyurl.com/c2l8yr / foes: http://tinyurl.com/ckjno5