| 摘要 |
PURPOSE:To prevent ink from dropping due to expansion of gas while increasing the volume of a cavity by absorbing change of volume generated in the gas sealed in the cavity by variation in the shape of a cap member. CONSTITUTION:A cap member 20 has sides (a), (b) and (c), is formed in a rectangular parallelepiped shape opened at the side in contact with an ink discharge face all in thickness (t). It is formed of a thermal expansion material having thermal expansion coefficient alpha. The member 20 is fitted on an ink discharge face 1C of a recording head 1. A thermal expansion material (thermal expansion coefficient alpha) such as rubber is so employed as the forming material of the member 20 that the volume expansion of gas coincides with the expansion of volume of a cavity of the cap, and the shape of the member 20 is formed to vary in its inner volume proportionally to the a before and after the change of an environmental temperature. |
