Compact zoom lens

Abstract

Abstract PURPOSE:To obtain the compact zoom lens by providing >=3 aspherical faces in a front system. CONSTITUTION:The zoom lens which consists of the front group having a negative refracting power and a rear group having a positive refracting power, successively from an object side and changes the focal length of the entire system by changing the air spacing between the front group and the rear group has >=3 aspherical faces in the entire system. There is an effect of correcting spherical aberrations when the aspherical face is used for the lens on the extreme object side in the rear group. There is an effect of correcting comatic aberrations in the peripheral part of the image plane when the aspherical face is desired to be formed on the lens of the extreme image side. On the other hand, there is an effect of correcting the distortion aberrations and curvature of field near the wide angle and when the aspherical face is used for the lens on the extreme object side in the front group. The refracting power of the respective group and respective lenses in intensified while the performance is maintained by effectively using the multiple aspherical faces in such a manner. Consequently, the number of lens element is decreased and the overall length and moving quantity are shortened.

Inventors

• 👤 Tetsuo Kono
• 👤 哲生 河野
• 👤 Naoshi Okada
• 👤 尚士 岡田

Bibliographic Details