| 摘要 |
PROBLEM TO BE SOLVED: To provide a more compact projection optical system.SOLUTION: A projection optical system comprises: a first optical system 013 for forming a second image conjugate to a first image 011; and a second optical system 015 comprising a reflection optical element for reflecting light from the second image and for projecting a third image conjugate to the second image on a face 016 to be projected. In the projection optical system, the first optical system comprises: a diaphragm 012; and at least one optical element having positive refractive power and the at least one optical element having negative refractive power arranged between the diaphragm and the second image. In the projection optical system, the optical element having the strongest positive refractive power in the at least one optical element having the positive refractive power is provided between the diaphragm and the optical element having the strongest negative refractive power in the at least one optical element having the negative refractive power. |
