| 摘要 |
PROBLEM TO BE SOLVED: To correctly detect a liquid discharge failure due to bending as well as non discharge etc. SOLUTION: A light beam LB from a light emitting element 13 such as a semiconductor laser or an LED is hit from a direction in which a light axis L intersects at right angles to a liquid droplet discharge direction of an ink droplet (liquid droplet) 12 discharged from a head nozzle surface (liquid droplet discharge surface) 11. A scattering light S generated when the light beam collides against the ink droplet is received by a light receiving element 15 such as a photo diode. The liquid discharge failure is detected from the photo detection data. In the liquid discharge failure detecting apparatus 16 as above, a distance changing means 20 is equipped which changes a distance h from the liquid droplet discharge surface to the light axis of the laser light on the basis of a diameter size of the discharged liquid droplet and a discharge speed. COPYRIGHT: (C)2009,JPO&INPIT |
