In order to make sure that the space camera has an extensive application and positioning accuracy of ground targets the focusing control systems should be designed to compensate the defocusing of the CCD plane in the space camera. First

in the interest of the low weight and miniaturization which are requested by the collectivity of the camera

we choose the scheme of screw to collectivity the link which changes the screw's running to the line movement of the glass. Then

the error analysis is done for the focusing mechanism and the source of the error is discussed. Finally

the vibration test and accuracy test are implemented on the mechanism. The optimized focusing mechanism has a weight of only 2.5Kg and a shape size of 186mm×144mm×60mm. The results of vibration test and accuracy test show that the first frequency of the focusing mechanism is 505Hz

the positioning accuracy of this focusing mechanism is 0.008mm

and the repeatability positioning accuracy is 0.0025mm

which satisfy the requirement of the optical system very well. This implies that our focusing mechanism has the characteristics of the compact structure

high stiffness and accuracy

which greatly meet the needs of the space camera.