Patent ID: 7278718

Claim:
A liquid injection apparatus having a liquid reservoir for containing liquid, a recording head for injecting the liquid, and a liquid supply passage for supplying the liquid in the liquid reservoir to the recording head, the apparatus comprising: a valve unit including a pressure chamber and a valve mechanism, wherein the pressure chamber temporarily retains the liquid at the liquid supply passage, wherein the liquid in the pressure chamber is consumed as the liquid is injected from the recording head, wherein in response to a negative pressure generated by the consumption of the liquid in the pressure chamber, a part of a wall of the pressure chamber is displaced and the valve mechanism selectively establishes a supply state where the liquid is supplied from the liquid supply passage to the pressure chamber and a non-supply state where the liquid is not supplied from the liquid supply passage to the pressure chamber; and a flow rate adjuster for forcibly changing a flow rate of the liquid that flows through the liquid supply passage.