JPH04187448A - Ink cartridge - Google Patents

Abstract

PURPOSE:To make print recovery operation simple and an ink cartridge compact in size and low in cost by providing a sub-tank for inducting ink into a print head, a non-return valve for preventing reverse flow of the ink, and a main tank for containing the ink attached slidably to the sub-tank. CONSTITUTION:An ink cartridge 102 is pushed to a frame 108 by the movement of a carriage 103. The pressure in the ink cartridge increases with decrease of the internal capacity of a sub-tank 5. The ink in the sub-tank 5 is sent to a print head 101 passing through an opened non-return valve 7 and a wall 10. At this time, the air pressure at the upper part of the ink in the main tank 1 also rises at the same time, so that an air opening valve 3 will not be opened because an upward force is loaded thereon. In this way, the ink is sent to the print head 101 and bubbles and dusts in the print head 101 are discharged to the outside together with the ink. Thus, the bubbles and the dusts in the print head are discharged together with the ink, so that ink drips can be ejected again.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application 1] The present invention relates to an ink cartridge for supplying ink to a print head of an inkjet printer.

[Prior Art] Conventionally, the following methods have been used to recover the print head by discharging dust, air bubbles, etc. inside the print head along with ink.

There have been methods in which ink is sucked from the print head using a separately provided pump, or ink is discharged by applying pressure to the ink from behind the print head.

Furthermore, even when a pressurizing means is provided in the ink cartridge as in JP-A-2-122938 shown in FIG. A pressing member 12 was required.

[Problems and Objectives to be Solved by the Invention] When a separate pump is provided for discharging ink, it is not only necessary to secure space for mounting the pump inside the printer, but also to control the pump. This also requires additional means, making it impossible to make the printer smaller and lower in price.

Also, if the ink cartridge is equipped with a pressurizing means,
As mentioned above, if the configuration of the pressurizing means is complicated, there are problems in that it not only has a large appearance but also is expensive and cannot be disposed of. Furthermore, 1
'If no means of exhausting the ink is provided, the print head may be exposed to air bubbles,
There was a problem in that once printing became impossible due to the influence of dust, etc., it was impossible to return to a state where two layers could be printed.

The present invention has been made in order to solve the above-mentioned problems, and its purpose is to easily perform printing recovery work, and to realize miniaturization and cost reduction of ink cartridges, thereby achieving ink cartridges. The goal is to make cartridges disposable.

Another purpose is to make the printer itself smaller and cheaper.

[Means for Solving the Problems] The ink cartridge/storage of the present invention includes a sub-tank for introducing ink into a print head, a check valve for preventing backflow of ink, and a sub-tank that accommodates ink and includes a sub-tank for introducing ink into a print head. It is characterized by a main tank that is slidably attached to the main tank.

[Function] According to the present invention, when the print head becomes unable to print, by moving the main tank, the internal volume of the ink cartridge is reduced and high pressure is generated in the ink, thereby reducing the pressure inside the print head. By discharging air bubbles, dust, etc. together with the ink, ink droplets can be ejected again.

[Example] Hereinafter, one embodiment of the present invention will be described based on the drawings.

The first leap is a perspective view of an inkjet printer equipped with an ink cartridge of the present invention. FIG. 2 is a sectional view of the ink cartridge of the present invention.

In FIG. 1, a print head 101 and an ink cartridge 102 are mounted on a carriage 103. A part of the main tank 1 of the ink cartridge 102 can be moved by a slight amount in the main scanning direction with respect to the carriage 103. Ink 2 is ink cartridge 10
2 directly to the print head 101. Carriage 1
03 moves in the main scanning direction along the guide shaft 104 by the power of a motor (not shown) transmitted by the belt 106. Recording is performed on recording paper 105 using ink ejected from print head 102 . 107 is recording paper 10
5 is a platen for feeding, and 108 is a frame of an inkjet printer.

In FIG. 2, a main tank 1 is formed above an ink cartridge 102, and contains ink 2.

The atmosphere release valve 3 is installed at the top of the ink cartridge 102 and is urged upward by a valve spring 4. Normally, the inside of an ink cartridge is isolated from the outside air.

The flow path portion 1a at the bottom of the main tank 1 has a cylindrical shape. Similarly, the inner diameter of the cylindrical sub-tank 5 is equal to that of the flow path portion 1a.
The flow path portion 1a is larger than the outer diameter of the tube, and the flow path portion 1a can fit inside and slide. 6 is a ring that prevents ink leakage. There is a check valve 7 inside the sub tank 5.
is provided, and is opened by a spring 8 during printing.

The main tank 1 is biased by a return spring 9, and the internal volume of the sub tank 5 is set to be maximum when the main tank 1 is not in operation.

Next, the operation of the embodiment with the above configuration will be explained in FIGS.
This will be explained with reference to FIG.

FIG. 3 shows the main tank 1 moving in the direction of arrow A due to an external force in the direction of arrow A.

The external force may be a human force or may be generated by moving the carriage 103 in FIG. 1 and pressing the ink cartridge 102 against the frame 108. As the internal volume of the sub-tank 5 decreases, the pressure inside the ink cartridge increases. The ink inside the sub-tank 5 flows through the open check valve 7 and the wall 1.
0 and is sent to the print head 101. At this time, as shown in FIG. 4, since the pressure of the air above the ink in the main tank 1 also rises at the same time, the atmospheric release valve 3 is subjected to an upward force and is not opened.

Through the above operations, ink is sent to the print head 101, and air bubbles and dust inside the print head 101 are discharged to the outside together with the ink. In this way, even if the print head once becomes unable to print, it will return and print will be possible again.

Next, Figure 5 shows what happens when main tank 1 returns.
This will be explained using FIG.

When the external force shown in FIG. 3 is removed, the main tank 1 moves in the direction of arrow B by the spring force of the return spring 9. As the volume inside the sub-tank 5 increases rapidly, the inside of the sub-tank 5 becomes a negative pressure. The spring 8, whose strength is set to be displaced by the negative pressure at this time, is pressed against the wall 10. The ink that tries to flow back from the print head 101 side due to the negative pressure is blocked in this way, and the ink is
The meniscus of the nozzle is not destroyed and there is no problem with printing.

Further, due to this negative pressure, the ink 2 in the main tank 1 flows into the sub tank 5, and the ink volume in the main tank 1 decreases. The air volume above the ink in the main tank 1 increases and becomes negative pressure. Then, as shown in FIG. 6, the atmosphere release valve 3 opens and the atmosphere flows in. The valve spring 4 is set to have a spring force such that it is displaced by the negative pressure generated at this time. When the pressure of the air above the ink becomes equal to the atmosphere, the atmosphere release valve 3 is closed by the valve spring 4. Here, the state returns to the state before the main tank 1 started operating.

Here, as an example, it is assumed that the main tank 1 operates in the main scanning direction, but as shown in Fig. 7, the main tank and the sub-tank are lined up in the vertical direction, and the main tank operates in the vertical direction. Alternatively, the same effect can be obtained even if the main tank is fixed and the sub tank is movable. Also, even if the ink cartridge is not on the carriage and is connected to the print head with a tube etc.
If the ink cartridge has the same configuration as this embodiment, the same effects as this embodiment can be obtained. Furthermore, as shown in FIG. 8, even if the size relationship of the outer diameters of the flow passage section 1a at the lower part of the main tank 1 and the sub-tank 5 is reversed so that the sub-tank 5 enters inside the flow passage section 1a, the above-mentioned Effects similar to those of the embodiment can be obtained.

[Effects of the Invention] As described above, according to the present invention, when the print head becomes unable to print, by moving the main tank, the internal volume of the ink cartridge is reduced and high pressure is generated in the ink. This operation has the effect that air bubbles, dust, etc. in the print head are discharged together with the ink, and ink droplets can be ejected again. Further, there is no need to separately provide an ink exhaust pressure means such as a pump, and there is also an effect that the printer can be made smaller and lower in price. Furthermore, since the ink cartridge itself has a simple structure, it can be disposable while still having an ink ejection function. Furthermore, if the ink cartridge of the present invention is mounted on a carriage as in this embodiment, and the movement of the carriage pushes it against the frame of the printer, the print head can be easily returned without getting one's hands dirty. It also has the effect of

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a printer equipped with an ink cartridge according to an embodiment of the present invention. FIG. 2 is a sectional view showing the structure of an ink cartridge according to an embodiment of the present invention. Figure 3 is a sectional view showing the ink pressurizing operation, Figure 4 is a sectional view showing the movement of the atmosphere release valve in Figure 2 during the ink pressurizing operation, and Figure 5 is the main tank in Figure 2. FIG. 6 is a cross-sectional view showing the movement of the atmosphere release valve during the main tank return operation. 7 and 8 are cross-sectional views showing an ink cartridge according to an embodiment of the present invention, and FIG. 9 is a cross-sectional view showing the structure of a conventional ink cartridge. 1...Main tank 3...Atmospheric release valve 5...Sub tank 7...Check valve 102...Ink cartridge or more ” 11 Figure 6 Figure 7 Figure 8

Claims (1)

[Claims] An ink cartridge for an inkjet printer that ejects ink droplets from a nozzle to record on a recording medium includes a sub-tank for introducing ink into a print head, a check valve for preventing backflow of ink, and a sub-tank for accommodating ink and for storing ink and for recording on a recording medium. An ink cartridge characterized by consisting of a main tank that is slidably attached to a sub-tank.