WO2004022347A1

WO2004022347A1 - A device used for continuously supplying ink to an ink-jet printer

Info

Publication number: WO2004022347A1
Application number: PCT/CN2003/000682
Authority: WO
Inventors: Qingguo Xiao
Original assignee: Print-Rite.Unicorn Image Products Co.Ltd., Of Zhuhai
Priority date: 2002-09-06
Filing date: 2003-08-14
Publication date: 2004-03-18
Also published as: CN1480334A; AU2003255119A1; CN1208197C

Abstract

The invention relates to a device used for continuously supplying ink to an ink-jet printer, more specially, relates to a device used for supplying ink to an ink-jet printer both continuously and in large amounts. The device is comprised of an ink reservoir, a conduct pipe and a one-way pressure valve. By selecting a suitable value at which the valve opens or closes, the level height of the ink reservoir may be ensured to be within a predetermined range. According to the different requirement, the ink reservoir designed may be disposed at any height above the printing head. Furthermore, the device of this type has the advantages that, the structure is simple and the cost of manufacture is low, more specially, it may apply to an ink-jet printer that has a large size and a wide breadth.

Description

TECHNICAL FIELD

The present invention relates to an ink supply device used in conjunction with an inkjet printer, and more particularly to an ink supply device that continuously supplies a large amount of ink. Background technique

Existing inkjet printers often have a print head with a cartridge, and a limited-capacity ink cartridge is detachably installed in the cartridge to supply ink to the print head. Since the ink capacity of each ink cartridge can usually only print 50-100 standard pages, the ink cartridge needs to be replaced frequently, which brings great inconvenience to printer users.

Therefore, people use the device shown in FIG. 1 to place a large-capacity ink tank 3 outside the printer 1, and use a hose 2 to connect the ink tank 3 and the ink cartridge 4, and close the air holes originally on the ink cartridge for ink supply. The ink capacity of one ink tank is equivalent to the ink capacity of several ink cartridges. At the same time, the ink can be easily added to the ink tank at any time in any state, so as to achieve the purpose of continuous ink supply in large batch printing or wide-line printing. Summary of the Invention

The above continuous ink supply device found a problem in use. The maximum liquid level of the ink tank can only be equal to or slightly less than the position of the nozzle of the print head. When the maximum liquid level of the ink tank is higher than the nozzle of the print head, it cannot print normally. Increased pressure at the print head will cause ink leakage from the print head to contaminate the printer and the print media shield. When the minimum liquid level in the ink tank is lower than the print head too much, it will not be able to suck ink due to insufficient print head suction. print. Therefore, this ink supply device is subject to the following restrictions: the height at the nozzle of the print head is relatively zero and is positive upwards and negative downwards, that is, the following conditions must be met at the same time in Figure 1:

HK 0;

I H2-H1 I <S;

Among them, H is the height of the water column and S is the maximum suction value of the print head.

This places great restrictions on the placement of the ink reservoir outside the printer, and specifically, places strict requirements on the placement of the ink reservoir on the workbench, which is extremely inconvenient for users.

An existing solution to the above problem is to lower the ink storage tank. As shown in FIG. 8, the continuous ink supply operation principle of a wide-line inkjet printer includes a pump 5 and a sensing device. When the ink in 4 drops to a certain position, the pump 5 starts to supply ink from the ink storage tank 3 to the relay container 4. When a certain liquid level is reached, the pump 5 stops working and cuts off the channel between the ink storage tank and the relay container 4, so that it works repeatedly. However, this ink supply device is relatively complicated and the manufacturing cost is too high.

The purpose of the present invention is to design a continuous ink supply device, which can be designed according to different needs so that the ink tank can be placed at any height position above the print head.

Another object of the present invention is to design a continuous ink supply device with a simple structure and low cost. In order to achieve the above object, the present invention still uses an ink tank, which has a large ink tank and is away from the container of the print head. Here, the term “distance” means that the ink tank does not move with the print head during the printing process. Instead, the ink tank is stationary relative to the workbench or printer housing. For example, the ink tank can be placed on the workbench or designed as a container integrated with the printer housing. A support for the ink tank can also be designed inside or outside the printer housing. The ink tank rests on a support. The device also has an air channel that communicates with the atmosphere. This air channel is a hole in the bottle-shaped ink reservoir, or the opening of an open container-like ink reservoir. The device includes a conduit, which is a flexible ink delivery channel that connects the ink reservoir and the print head. There is also a one-way pressure on-off valve in the ink channel from the ink reservoir to the print head. This valve is selectively opened and closed to make the ink in the ink reservoir flow to the print head unidirectionally, that is, it can be set at the outlet of the ink reservoir. It can also be set in the duct or near the print head, and it will open only when the pressure of the valve near the print head is lower than the pressure near the ink tank.

In this way, we can design the opening threshold of the one-way pressure on-off valve according to different requirements. The opening pressure threshold is a pressure value that can be selected as the height difference between the highest point of the ink reservoir and the print head. Obviously, when the sensitivity of the valve is low, That is, when the threshold tolerance is large, the height tolerance value of the ink tank can be increased accordingly. As long as the sum of the tolerance and the height of the ink tank is within the maximum suction value of the print head, normal ink supply can be ensured.

In order to prevent the moment when the conduit is connected to the print head, the pressure on the print head side of the one-way pressure on-off valve is too large to damage the print head. A one-way pressure protection valve can also be set in the device, which is connected in parallel with the one-way pressure on-off valve. When the pressure on the side of the print head is too high, it can be turned on, so that the ink near the print head can return to the ink tank, and the pressure is closed and closed when it is lower than the side of the ink tank. This can effectively prevent the print head from being damaged under high pressure, especially transient high pressure.

In order to be matched with the existing inkjet printer, the conduit can also be communicated with the printhead through an ink cartridge matched with the printhead cartridge compartment, and the valve is installed in the ink supply port of the ink cartridge.

For color printers, three or more sets of ink tanks, ducts, ink cartridges, and valves can be used. The sets are independent and contain different colors of ink. Brief description of the drawings

FIG. 1 is a working principle diagram of a continuous ink supply device of a conventional desktop inkjet printer;

2 is a working principle diagram of a continuous ink supply device of an inkjet printer according to the inventive concept; FIG. 3 is a structural diagram of an ink cartridge in which a one-way pressure on-off valve is installed in the ink cartridge;

FIG. 4 is a structural diagram of an ink cartridge in which a parallel one-way pressure on-off valve and a one-way pressure protection valve are installed in an ink cartridge; FIG. 6 is a schematic diagram of an ink supply state of a valve assembly;

Figure 7 is a schematic diagram of the backflow protection state of the valve assembly;

8 is a working principle diagram of a continuous ink supply device of a conventional wide-line inkjet printer;

FIG. 9 is a working principle diagram of a continuous ink supply device of a wide-line inkjet printer according to the inventive concept; FIG. 10 is a partially enlarged structural diagram of FIG. 9. detailed description .

The present invention will be described in further detail below with reference to several embodiments and drawings.

First embodiment

In order to explain the technical solution of the present invention, this embodiment takes a monochrome continuous ink supply device as an example. Referring to FIG. 2, for a structure related to the present invention but not belonging to the present invention, it is indicated by a two-dot chain line in the figure. The printer 1 has a slide bar 11 fixed by a bracket, and a print head with a cassette 10 can be driven by a motor. Slidingly mounted on the slide bar 11, the printing medium 8 is located under the print head, the ink tank 3 having a larger volume according to the present invention is fixed on the printer 1 housing through a bracket 7, and there is an air channel 6 on the top, The ink cartridge 4 with a smaller volume cooperates with the cartridge compartment 10, that is, the ink supply port 9 of the ink cartridge 4 is tightly connected with the ink supply needle of the print head. The duct 2 communicates with the ink reservoir 3 and the ink supply needle through the ink cartridge 4. The one-way pressure on-off valve or valve assembly can be installed at the connection portion 5 of the ink reservoir 3 and the duct 2 or in the ink supply port 9 of the ink cartridge 4. This example is installed in the ink supply port 9 of the ink cartridge 4.

Referring to FIG. 3, the ink cartridge 4 has a sealed ink cavity, the cavity has a conduit connection hole 12, an ink supply port has a built-in seal ring 13 which can be closely fitted with the ink supply needle, and a ink ring is provided near the ink supply port. The gland 15 and the valve core 14 made of elastic rubber have a through hole 16 in the gland 15. Unidirectional pressure opening and closing by gland I ^{5 is} composed of the valve core 14 and its working principle is as follows. The head of the valve core 14 is pressed against the lower surface of the gland 15 by the elastic force of the material itself. This pressure value is the threshold value of the valve. When it is used up for printing, the pressure is negative relative to its upper part. The head will leave the lower surface of the gland 15 under the pressure of the pressure difference. The ink from the ink reservoir can be replenished. When the pressure balance on both sides of the valve core is reached, the pressure difference Disappears, the one-way pressure on-off valve returns to the closed state.

As long as the shape and size of the spool 14 and the elasticity of the material are comprehensively designed, the pressure difference force K at which it is opened and the relative sizes H3, H4 of the ink reservoir and the print head in FIG. 2 and the maximum suction force S of the print head satisfy the following relationship :

K = H4;

S> H4-H3 ₀

The device will work normally. Therefore, the installation size of the ink tank can be determined for different models of inkjet printers, and the threshold of the spool can be designed accordingly.

Second embodiment

This example is different from the first example in that it takes into account the instantaneous impact pressure generated when the ink cartridge is installed in the cartridge compartment, which can cause permanent damage to the print head. To this end, a unidirectional pressure protection is added, and the process is also considered The two valves are made into components to improve the yield of the product. The configuration of the continuous ink supply device is the same as that in Figure 2.The structure of the ink cartridge is as follows:

Referring to FIG. 4, the same part numbers in FIG. 3 have the same meanings, and will not be described again. One-way pressure on-off valves and one-way pressure protection valves are used as valve components. In this example, the pressure cover 15 and the valve seat 17 are used. , Valve core 14 and tubular valve 18. The valve assembly can be installed at the connection between the ink tank and the duct, or in the middle of the duct. It can also be installed at the ink supply port of the ink cartridge as in this example. Its structure is shown in Figure 5. The valve seat 17 and the gland 15 are fixed to each other. And the skirt of the valve core 14 is pressed once, and the head of the valve core 14 is tightly pressed on the lower plane of the gland 15 by the elastic force of the material itself. There is a socket 19 with a hole in the plane area, and the socket 19 A blind tube 18 made of an elastic material is fixed, and the tube wall of the blind tube 18 has a slit-like hole 20 penetrating the tube wall. When the pressure at the upper and lower sides of the valve core 14 is the same, the head is pressed against the bottom plane of the gland and is closed. The slit hole 20 is tightly closed when the pressure inside and outside the pipe is the same, and it is also closed.

Referring to FIG. 6, when the ink is partially used by the printer, the pressure in the B area relative to the A area becomes larger, the blind tube 18 is squeezed due to the large external pressure, and the slit hole 20 is tightly closed. When the pressure exceeds the explained value, the valve The head of the core 14 is separated from the bottom plane of the gland 15 to form an ink supply channel indicated by an arrow in the figure.

Referring to Figure 7, the moment the ink cartridge is installed in the cartridge compartment, the The pressure increases sharply. At this time, the head of the valve core 14 will only be pressed tighter on the bottom plane of the gland 15, and the pressure will be transmitted to the inner cavity of the blind tube 18 through the socket 19. Under the action of higher internal pressure, The blind tube 18 expands, thereby opening the slit-shaped hole 20, forming a return channel indicated by an arrow in the figure.

Third embodiment

Referring to FIG. 9, this example is an example of the present invention applied to a wide-line inkjet printer. This is a four-color color wide-line inkjet printer. Since the wide-line inkjet printer has a larger frame 1, it is more suitable. The ink tank 4 is placed on the rack 1. Each ink tank 4 communicates with the print head 9 through its own duct 1. In order to prevent the permanent damage to the print head caused by the instantaneous impact pressure of the duct and the print head when it is connected, this example also uses The valve assembly with a one-way pressure protection valve, the valve assembly 21 is connected in series in the conduit 2, the structure of the valve assembly 21 can be seen in FIG. 10, and FIG. 10 is a partial enlarged view of FIG. 9, and is a sectional view of the main components of the valve assembly 21. function has been described in the second embodiment, the present embodiment is designed only fittings ²² and ^23, wherein the pipe joint 22 communicating with the print head, the pipe joint 23 in communication with the ink reservoir. Industrial applicability

Compared with the prior art, the present invention can freely adjust the height of the ink tank within a certain range. According to different printer types, the position where the ink tank can be fixed can be determined, and it is easy to obtain the ink tank full and almost empty limit states to the print head. Two height differences, as long as the threshold value of the one-way pressure on-off valve is properly selected. At the same time, the structure of the continuous ink supply device of this inkjet printer is relatively simple.

Claims

Claim

1. Continuous ink supply device for inkjet printer, including

Ink tank, a container with a large ink chamber and away from the print head, and an air channel communicating with the atmosphere; a duct, a flexible ink delivery channel connecting the ink tank and the print head;

It is characterized by:

A one-way pressure on-off valve is set in the ink passage from the ink reservoir to the print head, which selectively opens and closes, so that the ink in the ink reservoir flows unidirectionally to the print head.

2. The continuous ink supply device of the inkjet printer according to claim 1,

It is characterized by:

There is also a one-way pressure protection valve in the ink channel from the ink reservoir to the print head, which is connected in parallel with the one-way pressure on-off valve to selectively open and close, so that the ink near the print head can return to the ink reservoir.

3. The continuous ink supply device for an inkjet printer according to claim 1 or 2,

It is characterized by:

The duct communicates with the print head through an ink cartridge matched with the print head cartridge compartment, and the valve is located in the ink supply port of the ink cartridge.

4. The continuous ink supply device for an inkjet printer according to claim 1 or 2,

It is characterized by:

The valve is located at the connection between the ink reservoir and the conduit.

5. The continuous ink supply device for an inkjet printer according to claim 3,

It is characterized by:

There are three or more sets of the ink reservoir, the duct, the ink cartridge, and the valve, and each set is independent and contains different colors of ink.

6. The continuous ink supply device for an inkjet printer according to claim 4,

It is characterized by:

There are three or more sets of the ink reservoir, the conduit, and the valve, and each set is independent and contains inks of different colors.