Abstract: The idle operation is performed before time t1. The supply amount of the ink from the main tank 95 to the collection sub-tank 92 can be increased with the passage of time while the supply of the ink from the main tank 95 to the collection sub-tank 92 is continued before and after a transition to the print starting operation from the idle operation. Therefore, it is possible to deal with the start of ink discharge from the discharge head H. That is, the ink is already supplied to the collection sub-tank 92 by the supply pump 962 before the start of printing, and the start of ink discharge can be dealt with by increasing the ink supply amount. Therefore, the ink can be stably discharged by suppressing an output variation of the circulation pump 93 at the start of printing.

Abstract: The area of the openings Ow that discharges the white ink is larger than the area of the openings Ot that discharges the color inks. Since the openings Ow are secured to be large in this way, more white ink can be discharged to one pixel while the number of ink droplets discharged by the multi-drop method is suppressed or without depending on the multi-drop method. As a result, a generation amount of an ink mist can be suppressed while the discharge amount of the white ink is secured.

Abstract: The ink I is circulated along the circulation channel We at the low-speed flow rate Vl lower than that during the execution of the print mode when the print mode is stopped (Steps S107, S110). By circulatingly supplying the ink I to the discharge heads H in this way, the deterioration of the ink I can be also suppressed while the drying of the ink I is suppressed.

Abstract: The liquid L flowed into the bypass communication pipe 93 from the feed reservoir 91f can be returned to the feed reservoir 91f by way of the return reservoir 91r by carrying out the bypass circulation of circulating the liquid L along the bypass circulation channel Cb. Since this bypass communication pipe 93 bypasses the discharge heads H, the liquid L does not pass through the discharge heads H in the bypass circulation. As a result, the liquid L can be circulated between the feed reservoir 91f and the return reservoir 91r while the mixing of foreign substances into the discharge heads H from the respective reservoirs 91f, 91r is suppressed.

Abstract: The liquid L flowed into the bypass communication pipe 93 from the feed reservoir 91f can be returned to the feed reservoir 91f by way of the return reservoir 91r by carrying out the bypass circulation of circulating the liquid L along the bypass circulation channel Cb. Since this bypass communication pipe 93 bypasses the discharge heads H, the liquid L does not pass through the discharge heads H in the bypass circulation. As a result, the liquid L can be circulated between the feed reservoir 91f and the return reservoir 91r while the mixing of foreign substances into the discharge heads H from the respective reservoirs 91f, 91r is suppressed.

Abstract: The ink I is circulated along the circulation channel We at the low-speed flow rate Vl lower than that during the execution of the print mode when the print mode is stopped (Steps S107, S110). By circulatingly supplying the ink I to the discharge heads H in this way, the deterioration of the ink I can be also suppressed while the drying of the ink I is suppressed.

Abstract: The area of the openings Ow that discharges the white ink is larger than the area of the openings Ot that discharges the color inks. Since the openings Ow are secured to be large in this way, more white ink can be discharged to one pixel while the number of ink droplets discharged by the multi-drop method is suppressed or without depending on the multi-drop method. As a result, a generation amount of an ink mist can be suppressed while the discharge amount of the white ink is secured.