| 摘要 |
A deflecting mirror which deflects a laser beam emitted from a laser oscillator, a transfer lens, a cylindrical lens array which divides the laser beam having passed through the transfer lens into a plurality of laser beams, and a condensing lens which superposes the laser beams formed in the cylindrical lens array are included. The following formula is satisfied: 1/f=1/(a+b)+1/c, when: “a” is a distance between an emission opening of the laser oscillator and the deflecting mirror; “b” is a distance between the deflecting mirror and the transfer lens; “c” is a distance between the transfer lens and an incidence plane of the cylindrical lens array; and “f” is a focal length of the transfer lens. |
