| 摘要 |
An inspection unit of a drawing apparatus comprises: a light quantity sensor which receives light from a projection optical system of a drawing head when being located in a measuring point of light quantity for drawing; a lighting head which is inserted onto an optical path of the drawing head and receives at least part of light directed towards a spatial optical modulation device from the light source; and a bundle fiber and an inspection head which guide light received from the lighting head to the light quantity sensor located in an intermediate light quantity measuring point. As described above, the drawing apparatus acquires and compares the quantity of light from the projection optical system of the drawing head and the quantity of light collected from between the light source of the drawing head and the spatial optical modulation device. Therefore, even when the optical properties of the light quantity sensor have changed, it is possible to detect what caused the deterioration in the drawing head. |
