Device for focusing a microscope objective on a sample

Abstract

A device for focusing a microscope objective on a sample accurately with a high spatial resolution. The device has a positioning unit having a main body, an objective holder movably supported on the main body and adapted to hold the microscope objective, and an actuator for moving the objective holder along the optical axis of the microscope objective. The objective holder holds the microscope objective only at a front portion of the microscope objective facing the sample. The positioning unit includes one or more lever arms, each of which coupled at its one end via a first flexure bearing to the main body and at its other end via a second flexure bearing to the objective holder. The main body of the positioning unit is attached to a stage that carries the sample.

1 . A device for focusing a microscope objective on a sample, comprising:
 a positioning unit having a main body, an objective holder movably supported on the main body and adapted to hold the microscope objective, and an actuator for moving the objective holder along the optical axis of the microscope objective; wherein   the objective holder holds the microscope objective only at a front portion of the microscope objective facing the sample;   the positioning unit includes one or more lever arms, each of which coupled at its one end via a first flexure bearing to the main body and at its other end via a second flexure bearing to the objective holder; and   the main body of the positioning unit is attached to a stage that carries the sample.   
     
     
         2 . The device as recited in  claim 1 , further comprising two lever arms that are arranged in parallel to one another and form together with the main body and the objective holder a parallelogram configuration. 
     
     
         3 . The device as recited in  claim 1 , wherein the actuator is a piezoceramic element that is integrated into the main body of the positioning unit. 
     
     
         4 . The device as recited in  claim 1 , wherein
 the objective holder includes a ring having an internal thread; and   the microscope objective has at its front portion facing the sample an external thread on that the internal thread of the ring is screwed.   
     
     
         5 . The device as recited in  claim 1 , wherein
 the total length of the microscope objective along the optical axis is in a range from 1.7 Inch to 2.6 Inch;   the front portion at which the microscope objective is held and that faces the sample has a length in a range from 0.1 to 0.4 Inch along the optical axis; and   the focal length of the microscope objective is in a range from 0.1 to 0.2 Inch.   
     
     
         6 . A microscope having a device according to  claim 1 .