A focusing and leveling device and method

Abstract

The application discloses a focusing and leveling device and method. The device comprises: a displacement table for carrying a target object to be measured; an optical imaging system located on the side of the target object to be measured away from the displacement table; a vertical displacement sensor for measuring the surface shape of the target object to be measured; a driving mechanism for moving the displacement table along a transverse axis and / or a longitudinal axis; a vertical axis for moving the optical imaging system along the vertical axis; and a controller connected with the optical imaging system, the vertical displacement sensor and the driving mechanism, respectively. Based on the image of the target object to be measured collected by the optical imaging system, the blur scale of the image of the target object to be measured is calculated, the actual mapping relationship between the blur scale and the defocus amount is combined, the feedback compensation defocus amount is calculated, and the expected position of the vertical axis is updated according to the feedback compensation defocus amount. The defocus amount is compensated online.

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