JPH0464514B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an ink supply method.

[Prior art]

Among the various recording methods currently known, there is a non-impact recording method that generates almost no noise during recording, is capable of high-speed recording, and can record on plain paper without the need for special fixing processing. The so-called inkjet recording method that allows printing is an extremely useful method for realizing printing devices such as various printers and word processors. Various methods have been proposed for this inkjet recording method, some have been improved and commercialized, and others are still being worked on to put them into practical use. .

The inkjet recording method uses small droplets of recording liquid (referred to as ink in the following explanation).
Recording is carried out by flying particles (plet) using various operating principles and attaching them to a recording material such as paper.
An ink droplet generating device used in such an inkjet recording system, that is, an inkjet recording device, generally consists of an inkjet head for forming ink droplets and an ink supply system for supplying the inkjet head.

As for this ink supply system, Japanese Patent Application Laid-Open No. 55-121074
There are two types: a type that constantly supplies ink in circulation, as described in Japanese Patent Laid-Open No. 128465/1980, and a type that constantly supplies ink from a single ink introduction tube, as described in Japanese Patent Application Laid-open No. 128465/1983. Ru.

〔Problems to be solved〕

By the way, the first form of the ink jet head is generally called a single type or semi-multi type, which has about 1 to 10 ink ejection ports. Since the supply system requires less ink discharge and consumes less ink, it can be constructed relatively easily using a cartridge type tank or a single ink supply pipe.

However, the ink supply system for another type of full-line inkjet head, generally called a full-line multi-type, which is used for printing one line of paper almost simultaneously, has an extremely large number of ink ejection ports, and The overall ink consumption will also be incomparably greater than in the above case, so many ink supply pipes and large capacity tanks will be required, making the structure complex and large. However, there were some disadvantages.

On the other hand, as mentioned above, conventional ink supply systems constantly supply ink in a specific direction, so the continuous circulation supply system provides a stable ink supply that responds to various changes in recording by liquid ejection. An inconvenience has arisen that makes it difficult. The problem is not with the type that performs recording by scanning the head, but with the so-called full-line long head, which has an extremely large number of ejection ports arranged in the line printing direction, and is practically capable of printing a full line during recording. This has become a significant problem when recording with a fixed head.

Therefore, focusing on the problem of stable supply during recording caused by constant circulation, the present invention provides an ink supply method for an inkjet recording device that can achieve an appropriate ink condition for recording without problems related to ink supply. The inventors recognized this as a technical problem.

[Purpose of the invention]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to solve the above-mentioned drawbacks of the prior art. In other words, an object of the present invention is to eliminate inconveniences caused by the configuration of the ink supply system in an inkjet recording device, and to almost completely form ink droplets faithful to the input from all ink ejection ports. An object of the present invention is to provide an ink supply method.

Another object of the present invention is to provide an ink supply method capable of stably supplying ink for a long period of time to a full-line type ink jet head.

[Summary of the invention]

The ink supply method of the present invention that achieves the above object includes: an ink supply source that receives ink from an ink replenishment tank; a first ink flow path from the ink supply source to an ink jet head; a second ink flow path that is independent of the flow path and extends from the ink supply source to the ink jet head; a valve provided in the second ink flow path; and a second ink flow path that connects the ink supply source to the first ink flow path. and a pump capable of forming a forced flow of ink to the ink jet head, the method of supplying ink in an inkjet device includes: a pump capable of forming a forced flow of ink to the ink jet head, the method comprising: opening the valve and driving the pump; a first mode in which a circulating flow of ink is formed through the first ink flow path, the ink jet head, and the second ink flow path to reach the ink supply source again; and driving the pump with the valve in a closed state. a second mode in which an ink flow is formed from the ink supply source through the first ink channel to the ink jet head to unclog the ink ejection opening of the ink jet head; and a second mode in which the valve is opened. a third mode in which the pump is stopped and an ink flow is formed using capillary force from both the first ink flow path and the second ink flow path toward the ink jet head, and each of these modes is characterized in that it is switched according to the state of the ink jet head.

The present invention provides two
A first ink flow path and a second independent ink flow path are formed, and these are operated with a simple configuration including a pump acting on the first ink flow path and a valve provided on the second ink flow path. This alone makes it possible to form the ink flow, discharge the ink from the ejection ports, and also achieve stable and reliable ink supply to both the independent first and second ink channels during recording. , excellent inkjet recording can be made stable over a long period of time.

In this way, the above-mentioned effect can be achieved despite the simple structure of independent first and second ink flow paths, so there is no need for a complicated flow path structure to obtain the above-mentioned effect. The device can be made more compact.

In particular, the present invention can exhibit particularly excellent effects when applied to a full-line type inkjet recording device.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a block diagram outlining an embodiment of the invention. In FIG. 1, 101 is a pressure pump, 102 and 107 are ink tanks constituting an ink supply source, 103 is an ink pipe as a first ink flow path, and 105 is an ink pipe as a second ink flow path. , 108, 110 are ink pipes, 1
04 is a multi-nozzle inkjet head, 10
6 and 109 are valves, and 111 is an ink replenishment tank. And the inkjet head 104
The initial supply of ink to the printer is performed as follows. In other words,
With the valve 106 open and the valve 109 closed, the first ink tank 102 constituting the ink supply source is pressurized by the pressure pump 101, so that ink is drawn from the first ink tank 102.
The ink is supplied to an ink jet head 104 through an ink pipe 103 serving as a first ink flow path. Pressurizing the ink tank 102 discharges the air in the ink jet head 104 and the ink pipe 105, and the ink pipe 103 as the first ink flow path, the ink jet head 104, and the second ink flow are discharged from the first ink tank 102. This process is performed until an ink path leading to a second ink tank 107 constituting an ink supply source is communicated with ink through an ink pipe 105 as a path. Pressure is stopped when the ink path is communicated with ink,
When the valve 109 is opened, the first ink tank 102 and the second ink tank 107 pass through the ink pipes 108 and 110 so that the ink levels in the first ink tank 102 and the second ink tank 107, that is, the ink supply source, are equalized. .

Ink is supplied as follows when the ink jet head 104 is discharging ink.
That is, by opening the valves 106 and 109, ink is supplied to the first ink supply source.
From the ink tank 102 through an ink pipe 103 as a first ink flow path, and from the second ink tank 107 through an ink pipe 105 as a second ink flow path, independent first and second ink are supplied by capillary force. A flow of ink is formed and supplied toward the ink jet head 104 from the two ink pipes forming the flow path.

The ink tanks 102 and 107 constituting the ink supply source can be refilled with ink by refilling the second ink tank 107 at a constant level from the ink replenishment tank 111 with the valve 109 open. tank 102 and a second
The ink tank 107 of the printer can be refilled with ink at the same level.

Note that if air bubbles are mixed in the ink jet head 104 and a stable ejection condition cannot be obtained, the valve 109 is closed, the first ink tank 102 is pressurized by the pressure pump 101, and the first ink flow path is ,
Air bubbles can be easily removed by forming an ink flow in the order of the ink jet head and the second ink channel.

In addition, if the tip of the inkjet nozzle, that is, the ink discharge port is clogged, the valves 106 and 109 are closed, and the pressure pump 101 is used to remove the first ink tank 10.
2 can be easily released by applying pressure. That is, this pressurization allows ink to be discharged from the ink discharge port.

FIG. 2 is an exploded view illustrating a preferred embodiment of the ink jet recording apparatus of the present invention.

In FIG. 2, reference numeral 201 denotes an ink tank body serving as an ink supply source, which is divided into two ink chambers 202 and 203 by a partition wall 238. The ink chambers 202 and 203 communicate with each other through a communication pipe 204 that has an opening at the bottom of the ink chamber.
04 is attached with a valve 205.

The ink tank body 201 also has ink passage holes 210 and 210', which have openings 208 and 208' at the bottom of the ink chamber 202, and ink passage holes 210 and 210', which have openings 209 and 209' at the bottom of the ink chamber 203. 211 and 211' are attached, and ink conducting holes 210, 210', 211,
211' includes valves 212, 212', and
213, 213' are attached. Ink chamber 2
02 has an opening 240 in the upper part, and the pressure pump 2 is connected through the pressure pump joint 206.
07 can be connected. 215 is a grooved plate with ink conduction grooves 218, 218', 219, 2
19' and an ink replenishment opening 237 are provided, and ink conduction grooves 218, 218', 219, 2
Through holes 216, 216', 217, and 19' are provided in the ink tank body 201 at positions corresponding to the ink passage holes 210, 210', 211, and 211'.
217' are provided respectively. 214 is a packing for making the ink tank body 201 and the grooved plate come into close contact with each other;
Through holes (not shown) are provided at positions corresponding to 1 and 211', respectively, and openings (not shown) are provided at positions corresponding to the ink replenishment openings 237 of the grooved plate 215.

221 is the upper lid of the ink tank main body 201 which is an ink supply source, and through holes are provided at positions corresponding to the ends on the left side of the figure of the ink conduction grooves 218, 218', 219, and 219' provided in the grooved plate 215. 22
2, 222', 223, 223' are provided, and an ink refill opening 236 is also provided. Reference numeral 220 denotes a packing for tightly fitting the grooved plate 215 and the upper cover 221, and this includes through holes 222, 222', 223, 2 provided in the upper cover 221.
23' and an opening (both not shown) corresponding to the ink replenishment opening 236 are provided.

224 is an ink relay device, and the ink relay chamber 22
7, 227', 228, 228', and through holes 222, 222' provided in the upper lid 221,
223, 223' and ink conducting holes 225, 22
5', 226, and 226', respectively.

Ink tank body 201, packing 214,
The grooved plate 215, the packing 220, the upper lid 221, and the ink relay device 224 are each crimped and integrated by screwing or the like. Further, the ink tank main body 201, the grooved plate 215, and the top cover 221 can be integrated by joining, and in that case, the packings 214 and 220 are not necessarily required. 233 and 233' are multi-nozzle ink jet heads, each with an ink pipe 23
1,232 and 231', 232', joints 229, 230 and 229', 230' ink relay chambers 227, 228 and 227', 2
28'.

234 is an ink replenishment tank, and the upper lid 22
1 and grooved plate 237, packing 214, 22
The ink chamber 203 is provided with an ink injection device 235 for replenishing ink at a constant level into the ink chamber 203 through ink replenishment holes 236 and 237 of 0.0. The replenishment tank 234 is detachable from the ink tank main body 201 and can be replaced as necessary.

When filling the multi-nozzle ink jet head 233 with ink, the valves 212 and 2
13 is opened and the ink chamber 202 constituting the ink supply source is pressurized by the pressure pump 207, the valve 205 attached to the communication pipe 204 is closed, and the ink flows through the ink passage hole as the first ink flow path. 210, through hole 216, ink conduction groove 21
8, the ink is filled into the multi-nozzle ink jet head 233 through a flow path consisting of a through hole 222, an ink passage hole 225, an ink relay chamber 227, a joint 229, and an ink pipe 231. After filling the multi-nozzle ink jet head 233,
An ink pipe 232 serving as a second ink flow path that is independent of the first ink flow path, a joint 230, an ink relay chamber 228, and an ink passage hole 2
26, the ink flows into the ink chamber 203 through a flow path composed of the through hole 223, the ink conduction groove 219, the through hole 217, and the ink conduction hole 211, and the ink chamber 202
Pressure is applied until the ink flow path from the ink chamber 203, which constitutes the ink supply source, is filled with ink via the multi-nozzle ink jet head 233.

When the pressurization of the ink chamber 202 is stopped, the communication pipe 20
When the valve 205 attached to the ink chamber 4 is opened and the ink chambers 202 and 203 communicate with each other, the ink levels of the ink chambers 202 and 203, that is, the ink supply source become equal. When ink is ejected from the multi-nozzle ink jet head 233 in this state, the ink flows from the ink chamber 202 to the ink conduction groove 218, the ink relay chamber 227, and the ink pipe 2.
31 and the ink chamber 203
From the ink passage hole 219, the ink relay chamber 228,
An ink flow is formed and supplied to the multi-nozzle ink jet head 233 by capillary force through two independent channels of the second ink channel passing through the ink pipe 232. Similarly, when filling the other multi-nozzle ink jet head 233' with ink, the valves 212' and 213' are opened and the ink chamber 202, which constitutes the ink supply source, is pressurized by the pressure pump 107. As a result, the valve 205 attached to the communication pipe 204 is closed, and the ink flows through the ink passage hole 210', the through hole 216', and the ink passage groove 21 as the first ink flow path.
The ink is filled into the multi-nozzle ink jet head 233' through a flow path consisting of a through hole 222, an ink passage hole 225', an ink relay chamber 227', a joint 229', and an ink pipe 231'.

After filling the multi-nozzle ink jet head 233', the ink flows through the ink pipe 232' as a second ink flow path, the joint 230', the ink relay chamber 228', the ink passage hole 226', and the through hole 22'.
The ink flows into the ink chamber 203 through a flow path consisting of an ink passage hole 219', an ink passage hole 219', a through hole 217', and an ink passage hole 211', and flows from the ink chamber 202 through the multi-nozzle ink jet head 233'. Pressure is applied until the ink flow path leading to 203 is filled with ink.

When the pressurization of the ink chamber 202 is stopped, the communication pipe 20
4 is opened, and the ink chambers 202 and 203 communicate with each other, so that the ink levels of the ink chambers 202 and 203, that is, the ink supply source, become equal. In this state, when ink is ejected from the multi-nozzle ink jet head 233', the ink flows from the ink chamber 202 to the first ink flow path via the ink conduction groove 218', the ink relay chamber 227', and the ink pipe 231'. The multi-nozzle ink jet head 233' is supplied to the multi-nozzle ink jet head 233' by capillary force through two independent flow paths from the ink chamber 203 to the ink passage hole 219', the ink relay chamber 228', and the second ink flow path via the ink pipe 232'.
An ink flow is formed and supplied towards the ink. In the embodiment described above, the ink chamber 202 is connected to the multi-nozzle ink jet head 233 or 23.
3' to the ink chamber 203.
Although an example in which two ink flow paths are provided in each case has been shown, in the present invention, the number of pipes that supply ink to the multi-nozzle ink jet head can be further increased (however, the number of pipes that supply ink to the multi-nozzle ink jet head can be increased to the extent that the device structure is not complicated. ), and it is also possible to simultaneously supply ink to multiple multi-nozzle ink jet heads in one operation.

Multi-nozzle inkjet head 233,2
If air bubbles are mixed in 33' and stable ejection cannot be obtained, the air bubbles can be easily removed by circulating the ink in the same manner as when filling the multi-nozzle ink jet head with the interlayer described above. I can do it. In addition, if the tip of the inkjet nozzle, that is, the ink discharge port is clogged, the valves 213 and 213' are closed and the ink chamber 202 is closed.
It is also possible to release the clogging by applying pressure with a pressure pump. That is, this pressurization allows ink to be discharged from the ink discharge port.

[Effects of the Invention] The present invention provides two
A first ink flow path and a second independent ink flow path are formed, and these are operated with a simple configuration including a pump acting on the first ink flow path and a valve provided on the second ink flow path. This alone makes it possible to form the above-mentioned ink flow, discharge the ink from the ejection port, and also achieve stable and reliable ink supply to both the independent first and second ink channels during recording. , excellent inkjet recording can be made stable over a long period of time. In this way, the above-mentioned effect can be achieved despite the simple structure of the independent first and second ink flow paths, so the device can be used without having to have a complicated flow path structure to obtain the above-mentioned effect. can be made more compact.

In particular, the present invention can exhibit particularly excellent effects when applied to a full-line type inkjet recording device.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the concept of an ink supply method for an inkjet recording apparatus according to the present invention, and FIG. 2 is an exploded view illustrating an inkjet recording apparatus embodying the present invention. In the figure, 101, 207...pressure pump,
102,107...Ink tank, 103,10
5,108,110,231,231',232,
232'...Ink pipe, 104,233,2
33'...Multi-nozzle ink jet head,
106, 109, 205, 212, 212', 2
13,213'... Valve, 111,234...
Ink replenishment tank, 201, 77... Ink tank body, 202, 203... Ink chamber, 204
...Communication hole, 206...Joint for pressure pump, 208, 208', 209, 209', 240
...opening, 210, 210', 211, 211',
225, 225', 226, 226'... Ink conduction hole, 214, 220... Packing, 215...
...Grooved plate, 216, 216', 217, 217',
222, 222', 223, 223'...through hole,
218, 218', 219, 219'... Ink conduction groove, 224... Ink repeater, 227, 22
7,'228,228'...Ink relay chamber, 22
9,229', 230,230'... joint,
235...Ink injection device.

Claims (1)

[Scope of Claims] 1. An ink supply source that receives ink from an ink replenishment tank, a first ink flow path from the ink supply source to the ink jet head, and an ink flow path that is independent of the first ink flow path. a second ink flow path from an ink supply source to the ink jet head;
An ink jet device comprising: a valve provided in the second ink flow path; and a pump capable of forming a forced flow of ink from the ink supply source to the ink jet head via the first ink flow path. In the ink supply method, the valve is opened and the pump is driven to supply the ink from the ink supply source through the first ink flow path, the ink jet head, and the second ink flow path, and then return to the ink supply source. a first mode in which a circulating flow of ink is formed to reach the ink jet head from the ink supply source through the first ink channel to the ink jet head by driving the pump with the valve in a closed state; a second mode in which an ink flow is formed to unclog the ink ejection port of the ink discharge port; and a second mode in which the valve is opened to stop the pump and the ink flow is discharged from both the first ink flow path and the second ink flow path. An ink supply method comprising: a third mode in which an ink flow is formed using capillary force toward an ink jet head, and each of these modes is switched according to the state of the ink jet head. 2. The ink supply method according to claim 1, wherein the ink jet head is a full line type head in which a plurality of ejection ports are arranged so as to print one line.