Laser printing apparatus

A laser printing apparatus comprising:

• an excitation light generation section configured to generate excitation light;
• a laser light generation section including a nonlinear optical crystal and configured to generate UV laser light on a basis of the nonlinear optical crystal and the excitation light generated by the excitation light generation section;
• a laser light scanning section configured to two-dimensionally scan the UV laser light generated by the laser light generation section and irradiate a printing object with the UV laser light;
• a distance measurement light generation section configured to generate and emit distance measurement light for measuring a distance to a surface of the printing object;
• a merging mechanism disposed in a middle of a laser optical path of the UV laser light generated by the laser light generation section and reaching the laser light scanning section and configured to merge the distance measurement light generated by the distance measurement light generation section with the laser optical path;
• a distance measurement light receiving section configured to receive distance measurement light reflected on the surface of the printing object, returned, and separated from the laser optical path by the merging mechanism;
• a distance measurement section configured to measure a distance to the surface of the printing object on a basis of a light receiving position of the distance measurement light received by the distance measurement light receiving section;
• and
• a sealing section configured to hermetically seal the merging mechanism and in which a first transmission window through which the distance measurement light until merging with the laser optical path by the merging mechanism and the distance measurement light separated from the laser optical path by the merging mechanism are transmitted, and a second transmission window through which UV laser light and the distance measurement light merged by the merging mechanism are transmitted before the printing object is irradiated with the UV laser light and the distance measurement light are disposed.