Patent ID: 6766110
Filing Date: 2004-07-20
Classification: G02B

Abstract:
A zoom lens to be used for digital still cameras comprising:a whole lens assembly including a first lens or a first lens group assembled and fixed at the headmost position of said whole lens assembly; a second lens or a second lens group assembled in a separate inner lens barrel, and in said whole lens assembly positioned next to said first lens or said first lens group as a movable lens or lens group in said whole lens assembly; and a third lens or a third lens group assembled and fixed at the rearmost position in said whole lens assembly; and a means of supporting and operating said second lens or said second lens group to move said second lens or said second lens group between said first and said third lenses or said first and said third lens groups so that the focal length of said zoom lens can be changed from the shortest focal length to the longest focal length and vice versa; wherein during the operation of said means of supporting and operating said second lens or second lens group, the movement of said means of supporting and operating said second lens or said second lens group is assisted by tension of a spring such as an omega-shaped spring so that the speed of the movement can be increased and the movement cannot be stopped at midpoints of traveling of said second lens or lens group.