Camera lenses

Abstract

The disclosed camera lenses are applicable to digital image product. The lens set includes following parts from object space to image space: crescent-shaped first lens, second lens in crescent-shape symmetrical to the first lens, third lens adjacent to the image space, a aperture located between first lens and second lens. The first and second lenses are made from plastic. The third lens is made from glass. Convex of the first lens faces to the object space. The convex of the second lens faces to the image space. Curvature radius of surface faced to image space of the third lens is larger than curvature radius of surface faced to object space.

Description

【Technical field】 [0001] The invention relates to a lens group, in particular to a miniature lens group suitable for digital image products such as mobile phones. 【Background technique】 [0002] The lens design of the early lens is a spherical design, which means that any cut surface is a part of a circular arc. The reason for using a spherical surface is that processing is easier and a higher yield can be achieved. But the spherical surface is not the most suitable lens shape for optical imaging, because the spherical mirror will produce many optical defects such as spherical aberration and axial dispersion, resulting in blurred and out-of-focus images. In order to overcome the above-mentioned aberrations, lens designers must use many lenses in the lens to compensate. Therefore, while the imaging quality is improved, the length, outer diameter, weight and cost of the lens are correspondingly increased, so that the lens becomes large and heavy. However, in recent years, v...

AI Technical Summary

Problems solved by technology

However, the second and third lenses 93 and 94 used to correct aberrations are asymmetrical, and this asymmetrical lens will make it difficult to correct the assembly position. This structure can be found in US Pat. No. 4,212,517. content

In addition, because the main refractive power of the optical system of the lens group 90 is provided by the first lens 92, the curvature of the glass lens 92 will inevitably be very large, and in the case of a small aperture, it is extremely unfavorable for its processing, thus lead to lower productivity

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