US 11,865,847 B2
Liquid discharge apparatus
Fumio Nakazawa, Okazaki (JP); Yoshinori Osakabe, Seto (JP); Taichi Shirono, Nagoya (JP); and Sosuke Kuroyanagi, Nishio (JP)
Filed by BROTHER KOGYO KABUSHIKI KAISHA, Nagoya (JP)
Filed on Mar. 9, 2022, as Appl. No. 17/690,350.
Claims priority of application No. 2021-060336 (JP), filed on Mar. 31, 2021.
Prior Publication US 2022/0314634 A1, Oct. 6, 2022
Int. Cl. B41J 2/175 (2006.01)
CPC B41J 2/17596 (2013.01) [B41J 2/17509 (2013.01); B41J 2/17556 (2013.01); B41J 2/17566 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A liquid discharge apparatus comprising:
a head having a nozzle;
a tank in which a height of a liquid surface, in a case that the tank stores a maximum amount of a liquid, is positioned above an opening of the nozzle;
a gas channel configured to communicate a gas layer of the tank with outside of the tank, via an atmosphere opening port which is opened to the outside;
a valve unit configured to open or close the atmosphere opening port or the gas channel;
a memory configured to store an opening threshold value ΔV; and
a controller connected to the memory and configured to control the valve unit,
wherein the controller is configured to execute:
counting of a count value indicating an amount of the liquid discharged from the nozzle in a case that the valve unit is in a close state in which the valve unit closes the atmosphere opening port or the gas channel; and
making of the valve unit to be in an open state in which the valve unit opens the atmosphere opening port or the gas channel, under a condition that the count value has reached the opening threshold value ΔV, and
wherein the opening threshold value ΔV is represented by
ΔV≤(Vtmax−VI)×Pm/(P−Pm),
wherein Vtmax represents a volume of the tank, Vi represents the maximum amount of the liquid storable in the tank, P represents an atmospheric pressure, and Pm represents a meniscus-withstanding pressure of the liquid formed in the nozzle.