A flow path opening/closing apparatus includes a lid member and a receptacle member fixed to the lid member. The receptacle member includes a first wall that defines an outflow opening that is open to the lid member and a second wall provided around the first wall. The lid member closes the outflow opening by contacting the first wall due to relative movement of the lid member with respect to the receptacle member. A surface that is one of surfaces of the first wall and that faces the lid member and a surface that is one of surfaces of the second wall and that faces the lid member are separate by a stepped portion.

A liquid supply device includes a first conduit, a second conduit, one or more pumps, a heater, a filter, and a bypass conduit. The first conduit is connected to an upstream side of a liquid discharge head. The second conduit is connected to a downstream side of the liquid discharge head. The liquid is supplied through the first conduit to the liquid discharge head and recovered from the liquid discharge head through the second conduit. The heater is provided along the first conduit. The filter is provided in the first conduit on a downstream side of the heater. The bypass conduit is connected between a portion of the first conduit upstream with respect to the filter and a portion of the second conduit.

A liquid supply device includes a first conduit, a second conduit, one or more pumps, a heater, a filter, and a bypass conduit. The first conduit is connected to an upstream side of a liquid discharge head. The second conduit is connected to a downstream side of the liquid discharge head. The liquid is supplied through the first conduit to the liquid discharge head and recovered from the liquid discharge head through the second conduit. The heater is provided along the first conduit. The filter is provided in the first conduit on a downstream side of the heater. The bypass conduit is connected between a portion of the first conduit upstream with respect to the filter and a portion of the second conduit.

A liquid circulation device includes a housing having an outlet and an inlet, a circulation unit configured to convey liquid out of the housing through the outlet and recover liquid into the housing through the inlet, a liquid supplying unit configured to supply liquid into the housing, an air conveying unit configured to convey air into and out of the housing, a level detecting unit configured to detect a level of the liquid in the housing, a pressure sensing unit configured to detect a pressure of the air in the housing, and a control unit configured to control a pressure of the liquid in the housing by controlling the liquid supplying unit or the air conveying unit, based on the level and the pressure of the air.

A flow passage member includes: a supply flow passage through which liquid flows; a filter provided on a path of the supply flow passage, the liquid being configured to pass through the filter; a fixing member which constitutes a part of the supply flow passage and to which the filter is fixed; and a first member which constitutes a part of the supply flow passage and to which the fixing member is fixed; wherein the fixing member is made of thermoplastic resin, and the first member is made of any of thermosetting resin, metal, and ceramic.

A liquid ejecting head includes: a nozzle face; a filter; a downstream chamber that includes a first outlet and a second outlet for discharging the liquid, the downstream chamber being located downstream of the filter; a first flow passage that is in communication with the downstream chamber through the first outlet; a second flow passage that is in communication with the downstream chamber through the second outlet; and a common flow passage that is in communication with the first flow passage and the second flow passage, wherein, as viewed perpendicularly to the nozzle face, the first outlet is located at a position that is shifted from a center of the downstream chamber in a first direction, and the second outlet is located at a position that is shifted from the center of the downstream chamber in a second direction that is opposite of the first direction.

In a case where air bubbles exist in ink at the time of circulating the ink within a liquid ejection module, the amount circulating ink runs short and stability of ejection is blocked. The liquid ejection module has: a pressure chamber that communicates with an ejection port and which stores a liquid; an energy generation element that produces energy for causing a liquid to be ejected from the ejection port; a supply flow path that supplies a liquid to the pressure chamber; a collecting channel that collects a liquid from the pressure chamber; a liquid sending chamber that connects to the collecting channel; a connection flow path that connects the liquid sending chamber and the supply flow path; and a liquid sending unit configured to circulate a liquid, and the liquid sending chamber has a continuously inclined structure.

Provided is an inkjet printing apparatus comprising: a print head that ejects ink; a tank that contains ink to be supplied to the print head; a floating body that floats on the liquid surface of the ink inside the tank; and an electrode pin that detects the level of the liquid surface inside the tank. The floating body includes an opening portion in which to insert the electrode pin, and a perimeter of the opening portion protrudes from a top surface side of the floating body.

Provided is an inkjet printing apparatus comprising: a print head that ejects ink; a tank that contains ink to be supplied to the print head; a floating body that floats on the liquid surface of the ink inside the tank; and an electrode pin that detects the level of the liquid surface inside the tank. The floating body includes an opening portion in which to insert the electrode pin, and a perimeter of the opening portion protrudes from a top surface side of the floating body.

A liquid circulating device has: a supply flow path through which a liquid is supplied from a liquid supply source that stores the liquid to a liquid ejecting head that ejects the liquid; a collection flow path through which the liquid collected from the liquid ejecting head is returned to the supply flow path; and a liquid flowing portion that causes the liquid to flow in a circulation flow path including the supply flow path, the liquid ejecting head, and the collection flow path. An air capturing portion can capture bubbles and is provided in at least one of the supply flow path and collection flow path. The air capturing portion is disposed at a position higher than the position of the liquid ejecting head.