1. Technical Field
The present invention relates to a liquid ejecting apparatus such as an ink jet type recording apparatus and to a liquid ejecting apparatus in which a liquid stored in a liquid storage member is introduced into a pressure chamber and the liquid introduced into the pressure chamber is ejected from a nozzle as liquid droplets.
2. Related Art
A liquid ejecting apparatus is an apparatus that includes a liquid ejecting head and ejects various types of liquids from a liquid ejecting head. As the liquid ejecting apparatus, for example, there is an image recording apparatus such as an ink jet type printer (hereinafter, simply referred to as a printer) or an ink jet type plotter.
The liquid ejecting head has been developed which uses a cartridge type liquid storage member, because of ease of handling and distribution. For example, the printer has been widely prevalent which uses an ink cartridge in which a liquid-phase ink is sealed.
FIG. 5 is a schematic view illustrating an ink cartridge 3 as a liquid storage member in which a liquid-phase ink is sealed and a recording head 2 as a type of a liquid ejecting head.
When the ink cartridge 3 is provided in the recording head 2, the ink inside the ink cartridge 3 is introduced into the recording head 2 side via an ink introduction hole 32 opened to a front end side of an ink introduction needle 92 by inserting the ink introduction needle 92 of the recording head 2 into the ink cartridge 3.
The ink introduced into the recording head 2 is introduced into a common liquid chamber 96 (also referred to as a reservoir or a manifold) via an introduction path 95 inside the recording head 2. The ink introduced in the common liquid chamber 96 is supplied to each of a plurality of pressure chambers 98 communicating with the common liquid chamber 96. Then, the pressure inside the pressure chamber 98 is changed by driving a piezoelectric vibrator, a heating element or the like that is a type of a pressure generation unit and the ink is ejected from a nozzle 99 via the pressure chamber 98 by controlling the change in the pressure.
Here, when exchanging the ink cartridge 3 (when the ink cartridge is inserted into the ink introduction needle), there is a case where an excessive positive pressure or an excessive negative pressure may occur inside an ink flow path of the recording head 2 by button operation of an equipment user, change in a relative position occurred between the ink cartridge and the ink introduction needle, impact from the outside, or the like. Then, when the pressure occurred at this time is transmitted to the nozzle 99, a meniscus formed on the nozzle 99 is destroyed.
FIGS. 6A to 6C are enlarged views of the vicinity of the nozzle 99 illustrated in the dashed circle in FIG. 5 and schematic views describing states of a meniscus M in the nozzle 99 when the change in the pressure is transmitted.
A state illustrated in FIG. 6A is an appropriate state, however, there are cases that the meniscus M is excessively drawn into the pressure chamber 98 side from the inner peripheral surface of the nozzle 99 as illustrated in FIG. 6B and the meniscus M is inflated outwards from an opening surface of the ejection side of the nozzle 99 as illustrated in FIG. 6C. Then, when the pressure in the meniscus M exceeds a withstanding pressure, the meniscus M is not appropriately formed (a destroyed state), the ink may not be ejected, conversely, the ink may be leaked, and then dot failure may occur.
In order to solve such a problem, for example, a differential pressure valve structure has been known in the related art in which a valve is provided inside the ink flow path and the valve is open and closed according to the pressure inside the ink flow path, as disclosed in JP-A-2008-149646.
The structure disclosed in JP-A-2008-149646 is a valve that is configured such that an object of which is to stably supply the liquid to the downstream side by opening the valve in a case where the amount of the liquid at the downstream side is reduced by the liquid normally ejected from the nozzle and the downstream side has a negative pressure. However, there is a case where the valve does not respond to a sudden change in pressure from the impact outside. Thus, when the sudden change in the pressure occurs, the transmission of the change in the pressure to the nozzle may not be prevented and it is difficult to prevent the destruction of the meniscus.