The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 31, 2021
Filed:
Jun. 26, 2018
Shanghai Micro Electronics Equipment (Group) Co., Ltd., Shanghai, CN;
Shurong Li, Shanghai, CN;
Hailin Cheng, Shanghai, CN;
SHANGHAI MICRO ELECTRONICS EQUIPMENT (GROUP) CO., LTD., Shanghai, CN;
Abstract
An optical path compensation apparatus includes a wedge assembly, a driving mechanism and a preload unit. The wedge assembly includes a movable wedge and a fixed wedge. The movable wedge and the fixed wedge having equal wedge angles and respective wedge surfaces inclined in opposite directions. The preload unit is configured to elastically press the movable wedge on the fixed wedge, and the driving mechanism is configured to cause relative movement between the wedge surface of the movable wedge and the wedge surface of the fixed wedge. This optical path compensation apparatus is capable of achieving effective position correction of a focal plane of a measurement system for focusing and leveling in a smooth, convenient and precise way while not causing any error in other directions.