| 摘要 |
PROBLEM TO BE SOLVED: To smoothly execute a focusing action or a variable power adjustment action without moving the lens of an image forming optical system by providing the image forming optical system with a liquid-like or gel-like optical member constituted so that the thickness thereof can be varied in an optical axis direction, thereby making an image forming state variable. SOLUTION: The liquid-like or gel-like optical member 300 is constituted so that a liquid-like or gel-like optical element 300a in a lens holder 31 is moved to the inside of a cylinder 38 through a pipe 36 when the piston 39 of a bank part 40 is moved in a direction X. In accordance with it, a lower seal glass 33 is moved in a direction Y and the optical thickness of the optical member 300 is reduced. At this time, the relation between the moving amount in the direction X and that in the direction Y becomes Y=X×D1/D2 because of the relation between the diameter D1 of the lower part of the holder 31 and the diameter D2 of the piston 39. Thus, the respective adjustment actions can be executed by obtaining a correlation value between the moving amount in the direction X and that in the direction Y by a control part by using the values of D1 and D2 and controlling the position of the piston 39 based on the correlation value.
|
