A method for converting the existing mechanical zoom optical system to the focus tunable lens zoom optical system

The focus tunable lens (FTL), an emerging device, has brought a new development direction for the research of zoom optical systems, and the zoom lens designed with this lens has more advantages in response speed and mechanical vibration control than the conventional mechanical zoom system. However, there is a relative lack of design methods and computational theories for this type of system at present, and there is a lack of initial structure patents for reference. To solve this problem, this paper proposes a method that can convert the existing conventional mechanical zoom system into an FTL zoom system, and we first introduce the equivalent group element substitution theory for optical systems, then we design a computational screening algorithm for the equivalent FTL group element. We performed an example demonstration to illustrate the details of this method, and we finally obtain one FTL zoom optical system with an F/# of 4, a total length of 120 mm, and an 8 mm image plane. The whole design process is smooth, and the system structure is stable.