US 12,083,793 B2
Inkjet printing apparatus
Tomoyasu Okushima, Kyoto (JP); Tomonori Yasuda, Kyoto (JP); and Akihiro Ogawa, Kyoto (JP)
Assigned to SCREEN HOLDINGS CO., LTD., Kyoto (JP)
Appl. No. 17/796,457
Filed by SCREEN HOLDINGS CO., LTD., Kyoto (JP)
PCT Filed Mar. 16, 2021, PCT No. PCT/JP2021/010608
§ 371(c)(1), (2) Date Jul. 29, 2022,
PCT Pub. No. WO2021/200117, PCT Pub. Date Oct. 7, 2021.
Claims priority of application No. 2020-062877 (JP), filed on Mar. 31, 2020.
Prior Publication US 2023/0048119 A1, Feb. 16, 2023
Int. Cl. B41J 2/045 (2006.01)
CPC B41J 2/04573 (2013.01) [B41J 2/04505 (2013.01); B41J 2/04586 (2013.01)] 5 Claims
OG exemplary drawing
 
1. An inkjet printing apparatus for executing printing by dispensing ink droplets to a printing medium in transportation, comprising:
drive rollers arranged along a transport path of the printing medium for transporting the printing medium;
an encoder for measuring transporting distances of the printing medium by the drive rollers;
a printing unit having an upstream nozzle located upstream in the transport path, and a downstream nozzle located downstream of the upstream nozzle in the transport path;
a printing unit controller for controlling the printing unit based on an output of the encoder, after the upstream nozzle dispenses an ink droplet toward a specific position on the printing medium, to cause the downstream nozzle to dispense an ink droplet at a point of time the specific position has been transported just a predetermined distance; and
a drive roller controller for controlling speed change of the drive rollers in order to control a transporting speed of the printing medium,
wherein the drive roller controller is configured to control the drive rollers to make constant at each point of time during the speed change of the drive rollers, a speed difference which is a difference between a first speed which is a transporting speed of the printing medium when the upstream nozzle dispenses the ink droplet and a second speed which is a transporting speed of the printing medium when the downstream nozzle dispenses the ink droplet, and, thereby printing in a constant relationship between a landing position on the printing medium of the ink droplet relating to the upstream nozzle and a landing position on the printing medium of the ink droplet relating to the downstream nozzle during the speed change of the drive rollers.