Patent attributes
A pressure adjustment unit includes a flow passage including a first chamber, a second chamber, and a through hole. The apparatus further includes a partition wall that the through hole is formed, a first sealing portion having flexibility, a second sealing portion facing with the first sealing portion, a valve configured to close the flow passage by moving in a first direction, and to open the flow passage by moving in a second direction opposite to the first direction, a biasing member biasing the valve in the first direction, and a restricting portion restricting movement of the valve in the first direction by contact with a to-be-restricted portion of the valve, at a second portion different from a first portion where contact of the first sealing portion and the second sealing portion occurs.
