Optical design of digital camera zoom lenses employing plastic lens elements

Abstract

There is a great demand today for ever-smaller low-cost zoom lenses for digital cameras. To meet this demand, we have been realizing some compact zoom lenses by using plastic lens elements. Nowadays, plastic lens elements produced by injection molding are widely used in zoom lenses for digital cameras because of their suitability for volume production and ease of forming aspherical surfaces. Although using plastic lens elements in digital camera zoom lenses has its advantages mentioned above, there are some difficulties to be overcome for using plastic lens elements, such as an elevated sensitivity to the temperature change and the non existence of high-refraction materials. In this paper, we show some examples of commercialized digital camera zoom lens optical designs employing plastic lens elements such as a) retractable 3x zoom lens for digital still cameras and, b) 3x zoom lens using a right angle prism for digital still cameras and c) 25x zoom lens for digital camcorders in which benefits of plastic lens elements are effectively exploited and drawbacks of the material are well overcome.