1. Field of the Invention
The present invention relates to a liquid droplet jetting apparatus which jets a liquid droplet and an ink-jet printer which jets an ink.
2. Description of the Related Art
An ink-jet head which includes a plurality of pressure chambers communicating with a plurality of nozzles respectively, and a common liquid chamber supplying an ink to these pressure chambers, and which jets a droplet of the ink from a nozzle has hitherto been known. Such an ink-jet head selectively applies a pressure to the ink in the pressure chambers, and jets a droplet of the ink on to a recording paper from a nozzle communicating with the pressure chamber which is selected. For example, a serial ink-jet head described in Japanese Patent Application Laid-open No. H10-291311 includes a plurality of pressure chamber rows (three pressure chamber rows), and each pressure chamber row includes a plurality of pressure chambers (ink cavities) arranged in a longitudinal direction (paper feeding direction) of the serial ink-jet head. Furthermore, a common liquid chamber (ink supply chamber) which supplies the ink to each of the pressure chambers is extended along the longitudinal direction of the serial ink-jet head, in an area on an outer side of the pressure chamber rows and an area on an inner side (between the adjacent pressure chamber rows) of the pressure chamber rows.
The common liquid chamber which is arranged at the inner side of the two adjacent pressure chamber rows supplies ink to each of the pressure chambers belonging to the two pressure chamber rows positioned at both sides thereof. Therefore, in a case in which it is necessary to jet the ink simultaneously from a multiple number of pressure chambers, since an amount of ink supplied to the pressure chambers from the common liquid chamber at the inner side is increased temporarily, there is a possibility that the sufficient amount of ink is not supplied to each pressure chamber. Therefore, in the ink-jet head described in Japanese Patent Application Laid-open No. H10-291311, an ink communicating channel which communicates the common liquid chamber at the inner side with the common liquid chamber at the outer side, is provided in a partition wall (a column) which partitions the pressure chambers belonging to the each pressure chamber row. Moreover, when the amount of ink which is supplied from the common liquid chamber at the inner side, to the pressure chamber is increased temporarily, the ink is replenished from the common liquid chamber at the outer side to the common liquid chamber at the inner side via the ink communicating channel. Therefore, an insufficiency of the ink in the common liquid chamber at the inner side is prevented to a possible extent.