A projection lens and an imaging device
By designing a projection lens that incorporates a moving group and a Fresnel lens, the problems of cumbersome object distance adjustment and limited applicability in existing technologies are solved, enabling wide-range image reception and high-quality imaging at small object distances, while reducing the size and weight of the lens.
CN117008298BActive Publication Date: 2026-05-29JIAXING ZHONGRUN OPTICAL TECH
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- JIAXING ZHONGRUN OPTICAL TECH
- Filing Date
- 2023-07-31
- Publication Date
- 2026-05-29
Smart Images
Figure CN117008298B_ABST
Abstract
The present application relates to the field of optics, specifically to a projection lens and an imaging device. The projection lens is composed of a moving group and a Fresnel lens with positive focal length from the object plane side to the image plane side. The moving group is composed of a first lens with positive focal length, a second lens with negative focal length, and a third lens with positive focal length. The distance between the Fresnel lens and the moving group is controlled by the object distance of the projection lens. The moving group moves along the main optical axis of the projection lens. By setting a larger field of view, the projection lens can receive a larger range of images under smaller object distance conditions. The distance between the third lens and the Fresnel lens is adjustable, allowing the projection lens to receive images under different object distances at a fixed position, increasing the image receiving range of the projection lens and thus increasing the application range of the projection lens.
Need to check novelty before this filing date? Find Prior Art