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The camera phone is one of the hottest-selling items in all of consumer electronics. The little gadgets have become so ubiquitous that hardly anyone finds it odd anymore to see tourists squinting with one eye while pointing their cell phones at a Buddhist temple, a Greek statue, or a New York City skyscraper.
It's easy to see why analysts expect that camera phones will outsell conventional digital cameras and traditional film cameras combined.
But as anyone who has ever seen them can attest, the images that come out of camera phones leave plenty to be desired. Part of the problem is their CMOS imaging chips, which typically have a sensor array of only about one mega pixel?a half or less of the number in a low-end digital camera.
When they are, however, the only thing we may see more clearly is the other weakness of these cameras: their tiny, fixed-focus lenses, which have poor light-gathering and resolving power.
Here is a solution. It's modeled on the human eye, with its remarkable optical capabilities. It is called the FluidFocus lens. Like the lens of the eye, this lens, which we built at Philips Research Laboratories, in Eindhoven, the Netherlands, varies its focus by changing shape rather than by changing the relative positions of multiple lenses, as high-quality camera lenses do.
The tests of a prototype FluidFocus lens showed that it can be made nearly as small as a fixed-focus lens. Fixed-focus lenses use a small aperture and short focal length to keep most things in focus, but at the sacrifice of light-gathering power and therefore of picture quality.
At the same time, the prototype lens delivered sharpness that is easily on a par with that of variable-focus lenses. In fact, the optical quality of a liquid lens combined with a good imaging chip could soon give cell phone snapshots quality that rivals images from conventional- and much bulkier- digital cameras.
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26-06-2010, 01:16 PM
Please send the full seminar report and ppt on Fluid Focus Lens.
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fluid focus Lenses
This is a a unique variable-focus lens system that has no mechanical moving parts. This can come into application in areas such as digital cameras, camera phones, endoscopes, home security system, optical storage devices etc. It may consist of two immiscible fluids of different refractive indices: one a electrically conducting aqueous solution and the other an electrically non-conducting oil. They are housed in a short tube with end caps which are coated with a hydrophobic coating that makes this solution to form the shape of a hemispherical mass at the opposite end of the tube. Thuis it acts as a spherically curved lens.
When an an electric field across the hydrophobic coating, electrowetting happens ,ie, it becomes less hydrophobic.Due to this surface-tension the aqueous solution begins to wet the sidewalls of the tube. this causes the radius of curvature of the meniscus between the two fluids to alter and hance altering the focal length of the lens. The lens can be made completely flat (no lens effect) or even concave. be changing the magnitude of the electric field applied. Thus the lens acn be convex to flat to concave by just varying the elctric field strength.
This works on the principle of mimics the action of the human eye using a fluid lens that alters its focal length by changing its shape.This also overcomes the fixed-focus disadvantages of present lenses.
For more details, refer these links:
http://physorgnews308.html
http://photonicsArticle.aspx?AID=24918
http://freepatentsonlineEP1966635.html
http://imre.a-star.edu.sg/Upload/Fluid_Lens.pdf
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send me ppt and documentation of fluid focus lens
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to get information about the topuc"Fluid Focus Lens" refer the page link bellow
http://studentbank.in/report-fluid-focus...2#pid61112
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