Patent ID: 11940610
Assignee: NATIONAL CHENG KUNG UNIVERSITY
Field: Audio-visual technology (Electrical engineering)
Classification: CPC G  H | IPC G  H

Claim 4:
5. An autofocus method comprising:
controlling a focus light source to emit a focus light beam, so that a minimum light point of the focus light beam passing through an objective lens deviates from a focus of the objective lens, wherein the focus light beam sequentially passes through a defocus lens and the objective lens and then irradiates a sample;
receiving a focus reflected light beam generated after the focus light beam is reflected by the sample;
according to a center change of gravity, a position change, or an energy change of a light spot formed by the focus reflected light beam on an image plane of a first image sensor, driving the objective lens or the sample to move, so that the focus of the objective lens falls on the sample,
wherein a second image sensor is configured to receive an image beam generated after an illumination light beam irradiates the sample, wherein after the controller enables the focus of the objective lens to fall on the sample, a minimum light point of a parallel image beam, after passing through the objective lens, is back traced from an image plane of the second image sensor and falls on the sample.