A compact zoom lens design for cell phone is presented. A three groups lens system with five lens element is designed
for cell phone camera with 3M pixels and 2.5~3X optical zoom. The first lens is a negative lens with a concave surface
facing the object so that, when used for a long focal length, the rear principle plane is moved forwards to shorten the total
length of the lens. A positive lens group composed of three lens elements is arranged at the second lens group. By
control the optical power of the second lens group, the distortion can be reduced and also shortens the moving distance
of the second lens group while zooming. The fifth lens in the third lens group is a positive lens to control the incident
angle entering the photosensitive element. It is used for focusing when the object distance has changed.
As a portable device, such as PDA and cell phone, a small size build in virtual input device is more convenient for complex input demand. A few years ago, a creative idea called 'virtual keyboard' is announced, but up to now there's still no mass production method for this idea. In this paper we'll show the whole procedure of making a virtual keyboard. First of all is the HOE (Holographic Optical Element) design of keyboard image which yields a fan angle about 30 degrees, and then use the electron forming method to copy this pattern in high precision. And finally we can product this element by inject molding. With an adaptive lens design we can get a well correct keyboard image in distortion and a wilder fan angle about 70 degrees. With a batter alignment of HOE pattern lithography, we’re sure to get higher diffraction efficiency.
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