1. Field of the Invention
The present invention relates to a head for an ink-jet printer (hereinafter, “ink-jet printer head”), and an ink-jet printer
2. Description of the Related Art
An ink-jet printer which records images on a recording medium by jetting an ink, including a cavity unit which includes a plurality of nozzle holes jetting the ink, a plurality of pressure chambers communicating with the nozzle holes respectively, and a manifold which stores temporarily the ink to be supplied to the pressure chambers, and an energy imparting unit which imparts a jetting energy to the ink in the pressure chambers, has been hitherto known.
In a recording head used in such an ink-jet printer, in recent years, a high-speed printing and an improvement in an image quality have been sought. In view of this, a reduction in size of a head, and a reduction in weight have been carried out. Therefore, a length of the pressure chambers is shortened (reduced) and an amount of liquid droplets discharged at a time from the head is decreased, and the number of nozzles are increased. It makes possible to perform the high-speed printing.
In this case, even when the length of the pressure chambers is reduced, a resistance of (in) throttle portions which are communicating channels communicating between the pressure chambers and the manifold, is to be increased. When the resistance of the throttle portions is too small, there is a possibility that a pressure wave generated in the pressure chambers is propagated to adjacent pressure chambers through the manifold. Due to the propagation of the pressure wave to the adjacent pressure chambers, an amount of ink and/or a speed of a flow of ink which is supplied from the manifold to the pressure chambers after the jetting of ink becomes too high, and there is a possibility that a meniscus of the ink (an ink surface in the nozzle) cannot be maintained to be stable.
As a mechanism for adjusting the resistance of the throttle portions, adjusting the resistance of the throttles by providing thin and shallow grooves in a plate in a cavity unit has been known (refer to Japanese Patent Application Laid-open No. 2001-30483, for example).
Moreover, adjusting the resistance of the throttle portions by increasing a length of the throttle portions by making the throttle portions inclined (oblique) as it will be shown below, can be taken into consideration.
For example, a cavity unit 101 shown in FIG. 15 to FIG. 17 includes a stacked body 102 of a plurality of plates having a top plate arranged on an upper side of the stacked body 102, and a plate assembly 106 which is arranged on a lower side of the stacked body 102, and formed by attaching a nozzle plate 104 and a space plate 105, and these plates are attached integrally. The stacked body 102 includes a cavity plate 102A, a base plate 102B, an aperture plate 102C, two manifold plates 102D and 102E, and a damper plate 102F in this order from an upper side, and these plates are stacked (superimposed) and joined by a metal diffusion bonding. In such cavity unit 101, it can be taken into consideration to form communicating channels 201 (throttle portions) communicating with pressure chambers 102Aa of the cavity plate 102A, and manifolds 102Da and 102Ea of the manifold plates 102D and 102E as recesses which incline with respect to a longitudinal direction of the pressure chambers and which extend beyond the adjacent pressure chambers on an upper surface of the aperture plate 102 by a method such as half etching.