Pressure regulating unit, liquid supplying apparatus, and liquid ejecting apparatus

A liquid supplying apparatus comprising:

• a liquid container for containing liquid;
• and
• a pressure regulating unit provided on a liquid supply path communicating between the liquid container and a liquid ejection head for ejecting liquid;
• wherein the pressure regulating unit comprises:
• a first pressure chamber capable of introducing liquid;
• a second pressure chamber capable of leading out the liquid;
• a communication path that allows the first pressure chamber and the second pressure chamber to communicate with each other;
• a valve capable of adjusting an opening degree of the communication path;
• and
• an urging unit configured to apply an urging force to the valve, the urging force acting in a direction in which the communication path is closed and increasing according to a decrease in pressure in the first pressure chamber,
• the liquid supplying apparatus further comprising, at a position of the liquid supply path between the liquid container and the first pressure chamber in the pressure regulating unit, a pressurizing pump configured to pressurize the liquid contained in the liquid container so as to feed the liquid to the first pressure chamber.

A pressure regulating unit provided on a supply path communicating between a liquid container for containing liquid and a liquid ejection head for ejecting liquid, the unit comprising:

• a first pressure chamber capable of introducing liquid;
• a second pressure chamber capable of leading out the liquid;
• a communication path that allows the first pressure chamber and the second pressure chamber to communicate with each other;
• a valve capable of adjusting an opening degree of the communication path;
• and
• an urging unit configured to apply an urging force to the valve, the urging force acting in a direction in which the communication path is closed and increasing according to a decrease in pressure in the first pressure chamber,
• wherein the urging unit includes:
• a first urging member configured to apply a predetermined first urging force that acts in the direction in which the communication path is closed and increases according to a decrease in pressure in the first pressure chamber;
• and
• a second urging member configured to apply a second urging force to the valve, the second urging force acting in the direction in which the communication path is closed,
• wherein at least a part of the first pressure chamber is formed of a first flexible member that is displaced according to the pressure in the first pressure chamber, and
• the first flexible member functions as the first urging member by applying, to the valve, an urging force as the first urging force that changes according to displacement of the first flexible member.