JPH0730366Y2 - Filter device in inkjet printer head - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to an ink jet printer that ejects solid ink melted from a jet mechanism installed on the outer periphery of a rotating printer head for printing. The present invention relates to a filter device provided at an end portion of a supply tube for supplying water.

[Conventional technology]

A so-called inkjet printer, which ejects ink from a nozzle to print on a recording paper surface, is widely used because high-speed printing is possible.

5 to 7 are views showing a conventional filter device in such an ink jet printer.

In FIG. 5, reference numeral 1 is an ink reservoir in which a plurality of ink tanks for accommodating the inks 1a of the respective colors are installed, and 2 is an ink reservoir cover installed above the ink reservoir 1. The ink reservoir cover 2 includes a plurality of inks. Through holes 2a are provided corresponding to the ink surfaces of the tanks. The reference numeral 3 designates a plurality of jet mechanisms for forming a predetermined print on the recording paper by supplying the ink 1a from the supply tube 4 which can be seen at the lower end of the filter device 4a to form a predetermined print on the recording paper. And a cylindrical vibrating body element 3b fitted through.

Reference numeral 5 is a head cover, 6 and 7 are heaters for keeping the temperature of the ink 1a, and 8 is a printer head composed of the above-mentioned elements.

Reference numeral 9 is a head motor for rotating the printer head 8, 9a is a rotary shaft, and 10 is a frame.

Then, the ink in the ink tank is filtered by the filter 4a, and then the jet mechanism 3 is passed through the supply tube 4.
It is designed to be jetted by a filter device
Since 4a is individually provided in each supply tube 4, the size of the filter 4a is small, so that the filtering area of the filter is small and clogging is likely to occur.

Therefore, conventionally, as shown in FIG. 6, the filter device is enlarged to simultaneously filter a plurality of supply tubes.

That is, in FIG. 6, 41 is a filter housing which is an arc-shaped housing in which a plurality of supply tubes 4 are fitted,
A filter 42 is stretched on the bottom surface thereof. A filter device 43 is constituted by the filter housing 41 and the filter 42. 41a is a suction port for fitting the supply tube 4 and sucking ink. The filter device 43 is always submerged in the ink, and the ink, which is filtered by the filter 42 and is present in the filter housing 41, is taken into the supply tube 4.

By the way, in the above-mentioned inkjet printer, in order to remove the clogging of the nozzle or the bubble (bubble) generated in the ink flow path from the supply tube to the nozzle, purging or discarding is performed before starting the printing operation. A so-called ink sweeping operation (hereinafter referred to as purging) is required.

Before this purging is performed, a preparatory work called head tending is performed. This head tending is performed in order to return the ink remaining in the nozzles to the ink tank by jetting a volatile ink solvent such as ethanol from the nozzle openings, and also to clean the nozzle surface.

If purging is performed with ink remaining in the nozzles, a large amount of bubbles will remain in the nozzles after purging, and even if the vibrating element of the jet mechanism is driven, the expansion and contraction of the nozzles will be absorbed by the bubbles. It becomes impossible to eject ink.

For these reasons, both the purging and head tending preparation operations are indispensable before starting the printing operation in order to obtain good printing.

[Problems to be solved by the invention]

However, in the above-mentioned conventional technique, the ink remaining in the nozzles cannot be properly removed by head tending, and the intended purpose of purging cannot be achieved.

That is, when ethanol as an ink solvent is jetted from the nozzle opening during head tending, the ink remaining in the nozzle breaks the surface tension of the nozzle orifice, flows back into the ink tank in the supply tube, and then again causes capillary phenomenon. It rises and reaches a predetermined position. On the other hand, ethanol absorbs heat in a supply tube in a short time and evaporates.

At this time, a minute pressure is generated in the supply tube due to evaporation, and pressure fluctuation occurs in the filter housing where the ends of the supply tubes communicate with each other. When the ink is blown from the nozzle and the ink remaining in the nozzle closes the orifice or the intermediate portion of the nozzle, bubbles are generated between the ink that has risen due to the purging that is subsequently performed and the residual ink, and perfect purging cannot be performed. Become.

[Means for solving problems]

In an inkjet printer that prints on a recording surface by ejecting the ink in an ink tank from a nozzle of a jet mechanism through a supply tube, it has a filter device that filters the ink, and this filter device is fitted to the end of the supply tube. A filter housing having a plurality of suction ports and a filter stretched over the filter housing, and a standing wall for interrupting pressure transmission between the supply tubes is provided between adjacent suction ports. It is intended to solve the conventional problems.

[Action]

In this invention, the pressure generated in the supply tube by evaporation of ethanol or the like used for head tending is transmitted to the inside of the filter housing through the suction port, but is blocked by the standing wall formed between the suction ports. As a result, the increase in pressure in one supply tube does not affect the other supply tube at all, and thus a phenomenon occurs in which ink is ejected from another supply tube adjacent to the head-tending supply tube. Therefore, proper purging can be performed.

[Example of device]

An embodiment of the present invention will be described with reference to the drawings. The same parts as those of the conventional technique are designated by the same reference numerals, and duplicate description will be omitted.

1 to 4 are views showing an embodiment of the present invention.

In the figure, 44 is the back surface 41b of the filter housing 41.
It is a standing wall that is installed in parallel. As shown in FIG. 3, the standing wall 44 is formed from the circumferential end of the fan-shaped filter housing,
It is radially formed so as to partition each suction port. A gap 44a is provided between the standing walls 44. If this gap 44a is not formed, each suction port becomes the same as in the prior art in which each suction port has its own filter, and the filter clogging phenomenon easily occurs.

In this way, the suction port 41a on the back surface 41b of the filter housing 41 is opened in the center direction, and the adjoining portion is opened to the standing wall 4a.
Since it is divided by 4, the pressure fluctuation of each supply tube 4 is transmitted to the filter housing 41, but the vertical wall 44
It is absorbed in the surrounding area by the and does not affect other supply tubes.

[Effect of device]

According to the above-described structure and operation, when purging the ink supply path from the ink tank to the nozzle in the inkjet printer, the ink in the ink tank is not discharged when the residual ink recirculation work (head tending) of the nozzle etc. prior to this purging. In particular, since the ink does not flow into the adjacent ink supply path, proper purging is possible and clear print formation is possible.

[Brief description of drawings]

FIG. 1 is a perspective view of an essential part of a filter device according to the present invention, FIG. 2 is a plan view of the same as above, FIG.
FIG. 5 is a sectional view taken along line IV in FIG. 3, FIG. 5 is a sectional view of an essential part of an ink jet printer including a conventional filter device, and FIG. 6 is a perspective view of another conventional filter device. The figure is a partially cutaway sectional view showing a usage state of the filter. In the figure, 1 ... Ink reservoir 3 ... Jet mechanism 3a ... Nozzle 3b ... Oscillator element 4 ... Supply tube 41 ... Filter housing 42 ... Filter 43 ... Filter device 44 ... Standing wall

Claims (1)

[Scope of utility model registration request] 1. An ink jet printer for ejecting ink in an ink tank from a nozzle of a jet mechanism through a supply tube to print on a recording surface, comprising a filter device for filtering ink, and this filter device is provided. It is composed of a filter housing having a plurality of suction ports fitted to the tube end and a filter stretched over the filter housing, and for interrupting pressure transmission between the supply tubes between adjacent suction ports. A filter device for an inkjet printer head, which is provided with a standing wall.