JPS5814763A - Ink jet recorder - Google Patents

Abstract

PURPOSE:To simplify an ink system, and to improve maintenance capability by forming a platen means and a paper guide means detachably, an ink supply tank in a fixed injection type tank and an ink supply means in an integrally molded tube. CONSTITUTION:When starting record, a pump 12 is turned while the cover means 11 of a rotary cleaning means is left as it is fast stuck to a nozzle section, ink is circulated between the tank 5 and a head 2, bubbles in the tubes 15, 16 are also discharged into the tank 5 together with ink at that time, and ink is all refreshed. If bubbles remain in a pressure chamber 22 is the head or clogging is generated, bubbles are extruded from the nozzle 23 when a valve 14 is closed and the pump 12 is rotated. Since the tank 5 adopts a fixed injection type, it can freely be arranged, and there is no danger of the leakage of ink and the mixing of bubbles. Since the tubes 15, 16 adopt integral types, ones having low steam permeability can be used, and the problems of bubbles and the precipitation of dyestuffs and the like can be solved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inkjet recording device flK that performs recording by ejecting ink directly onto a recording medium Kfli.

Among the inkjet recording systems, there is an fK (Q) system, and among these, the on-demand system, which was shown in Japanese Patent Application Laid-Open No. 51-35231 Misaki, has a simple, compact, and low-cost recording snowmaking principle. It is expected that it will be possible. However, as described in the prior art, the ink supply means including the ink tank (ink cartridge) has a complicated structure, which is an obstacle to miniaturization and cost reduction of the device.

The present invention eliminates the above disadvantages in a financial sense, and in addition to simplifying the ink system, it also takes into consideration the need for maintenance, and realizes a small and low-cost inkjet recording device. The present invention will be explained based on the following.

FIG. 1 shows a plan view (a), a front view (b), a right side view (C), and a left side view (d) of an inkjet recording device according to the present invention.
). A carriage means that holds one recording head 2 and moves along the shaft 3, and flexible ink supply tube bodies 6a to 6e that guide ink from four ink tanks 5 to the recording head 2 are held on the shaft 6fK and convey the recording medium (paper )
It is a platen means for feeding the 7Fi recording paper in a direction perpendicular to the moving direction of the carriage means 1 by frictional force, and is a paper guide that serves as a guide for winding the 7Fi recording paper around the platen means 5a to 5θ.

(The plan view (a) is shown with the paper guide 7 removed.)
These are a DC motor for moving the 8-carriage means 1 via a belt, wire, etc. 9, and a stepping motor for driving the 10-carriage shaft 6f (platen means 6a to 6e). Reference numeral 11 denotes a lid means that comes into close contact with the nozzle portion of the recording head 2 while recording is stopped.

In order to explain the features of the present invention in more detail, the configuration of the main parts of the recording apparatus is shown in FIG. 2 and subsequent figures.

2(a) (d) are details of the recording head used in the recording apparatus of the present invention. As shown in FIG. 2(a), a plurality of pressure chambers 2 are formed on both sides of the glass substrate 210 by etching.
2. Ink is supplied from the pipes 15 and 16 through an ink reservoir portion 24 having a relatively large internal volume, which forms grooves such as nozzles 23 and guides ink to these pressure chambers 22 . As shown in the same figure (b) Vr, this head is made by juxtaposing glass pieces 25 having the same thickness as the glass substrate 21 with the grooves formed on both sides, and forming a relatively thin diaphragm (flexible wall) from both sides. The glass plates 26 and 27 are bonded together by a method such as fusion bonding.

At this time, the glass substrate 21, the glass piece 25, and the glass plate 2
The space created by 6.27 forms the reservoir 24.

Therefore, this space has a sufficiently large volume and low ink flow resistance compared to groove portions of the pressure chamber 22, nozzle 23, etc., which are made by etching and have a depth of 10 to several 100 μm. Further, by simultaneously forming a filter portion 29 by etching between the reservoir 24 and the pressure chamber 220, a filter in the middle of the ink supply path is not required, and the structure can be simplified. A piezoelectric element (not shown) is arranged above the glass plates 26 and 27 (a portion corresponding to the pressure chamber 22), and the piezoelectric element is bent in response to an electric pulse, and ink is ejected from the nozzle 23. Even more preferably, in order to improve the ink filling performance, island-shaped protrusions 28 can be provided before and after the circular pressure chamber 22 so as to direct the flow of ink along the wall surface as shown by the arrow.

The ink supply system of the recording apparatus of the present invention using the above recording head is constructed as shown in FIG. 3 below. In the figure, 5 is an ink tank, 12 pump means, 2 recording heads, 14
The valve means 15 and 16 are ink supply passages formed by tubes. Furthermore, a lid means 11 is provided on the curved surface of the head 2 so as to face the head 2 at a position offset from the recording range (range in the diagram gX1).

The operation of the recording apparatus of the present invention will be clarified according to FIG. The lid means 11 made of a member such as rubber is kept in close contact with the front surface of the nozzle while recording is stopped, and can also serve as a lid means for preventing clogging due to drying of ink in the nozzle portion. Although various structures of the lid means 11 can be considered,
A rotary cleaning means having a notch 18 is shown as an example that meets the objective 5- of the present invention. - When you are about to start recording (including when initially filling the head with ink or replenishing ink), make sure that the lid means 11 is brought into close contact with the nozzle part! Rotate the pump 12. By keeping 14 valves normally open (one normally open valve), the ink circulates from the ink tank 5 to the head 2 (reservoir) to the ink tank 5, and at this time, the ink circulates through the tube 15.1.
Air bubbles in the ink tank 6 are also discharged into the ink tank 5 together with the ink, and are removed to the outside through the air bubble vent hole 19 of the ink tank. In order to prevent foreign matter from entering the air, it is preferable that the degassing holes be a collection of sufficiently small holes, or that an air filter or the like be installed. In this state, air bubbles in the tubes 15, 16 and in the reservoir part 24 of the head 2 are completely removed without wasting any ink. Furthermore, this circulation 11 also has the effect of refreshing the entire ink.

Then, the nozzle is opened by rotating the lid means 11 to clean the front surface of the head and positioning the notch 18 at the front surface of the nozzle as shown by the dashed line in FIG. 36. By further rotating the pump 12 in this state, a portion of the ink is sent from the reservoir 24 to the pressure chamber 22 and the nozzle 23. Since this ink does not contain any air bubbles at the first operation, the inside of the head is completely filled with ink just by flowing out a very small amount of ink from the tip of the nozzle 23. Through the series of operations described above, the head becomes ready for recording and is moved by the carriage 1 to the recording position. The only function of the valve 14 here is that this normally open valve 14 remains open during normal recording and supplies ink during recording. If the nozzle remains nearby and cannot be printed, or if the nozzle tip becomes clogged due to long-term storage, etc.
When the valve 14 is closed and the pump 12 is rotated, ink is pushed out from the tip of the nozzle 23 at high speed by the high pressure of the pump, thereby eliminating all the troubles caused by air bubbles and clogging. It should be noted that while the lid means 11 is rotating, the front surface of the nozzle 25 is also cleaned at the same time. To ensure this, the pump 12 is operated while the lid means 11 is being rotated, so that the nozzle is filled with ink. Since the lid rotates under pressure, there is no need to worry about pushing dirt, debris, etc. into the fine nozzle. Generally speaking, in inkjet recording, especially on-demand printing, the nozzle is fine and the ink droplet ejection speed is relatively slow, and the effects of minute dust, residual ink, etc. on the front of the nozzle may disturb the direction of particle ejection and affect print quality. figure. Therefore, even when removing air bubbles or clearing clogging, if the ink is pushed out of the nozzle and then immediately starts printing, it will lead to unfavorable results.Especially in a multi-nozzle head like the present invention, the nozzles are close together. Therefore, the influence of residual ink is large. Therefore, the leaning action as in this embodiment brings about a great effect.

The above series of operations, i.e., ink circulation (bubble expulsion)
→ Nozzle open resistance ink leakage from some heads → Pulp closure (depending on conditions such as air bubbles, clogging, etc.) → Recordable state The cycle does not necessarily need to be performed every time a recording operation is performed, and the recording pause time If it is short, it is conceivable that printing will be possible without ink circulation or with only a small amount of ink circulation. In addition, if air bubbles are mixed in due to an unexpected impact during initial filling or ink replenishment, please circulate the ink and close the valve to prevent clogging due to long-term recording interruptions or air bubbles that may interfere with the flow inside the head. Since it is sufficient to eject ink from the ink, a more practical configuration can be achieved by setting the operation mode according to the situation at that time. For example, it is possible to consider a cape that automatically sets the operation mode using a built-in timer depending on the length of the recording pause time.

For example, when recording is finished, returning the head 2 to the original position and closing the lid 11 can stutter, but even during recording, if no data is received and recording is stopped for a long time, it will stutter. By returning the head 2 to the papermaking standby position (it may be possible to further perform the 7th step 11), it is possible to immediately respond to ink circulation, etc. before the start of recording.

9- In addition, when the lid means does not have the function of cleaning means as in this example, it is desirable to install the cleaning means separately, for example, on the left side of the lid means. Both air bubbles and clogging, which were weaknesses of inkjet recording devices, were solved at the same time.

Regarding the above-mentioned ink tank, the general method is to replace the ink cartridge each time. However, the connection point between the ink cartridge and the chain is constructed with a needle with a sharp tip, and the cartridge has a rubber member to connect with the needle, which causes problems with ink leakage and durability of K11. The shape is also limited due to the ease with which it can be handled. Furthermore, the cost of the cartridge itself is high. Also, as in the present invention, two ink tanks are provided.
The structure in which the book tube is connected further complicates the cartridge. In view of these points, in the present invention, the ink tank 5 is of a fixed type, and ink is replenished using a method in which ink packed in a very simple container is fed into the fixed tank from the injection port 5a.

Therefore, the ink tank can be freely placed without having to take a flat or other shape, and since it is a fixed tank, there are no limitations on the material, etc., and there are no problems with ink leakage or air bubbles caused by incomplete connections. It was also advantageous. In the present invention, taking advantage of the free shape, the recording device is rationally arranged in an empty base of the recording device, as shown in Figure 1 (c) K. This position is outside the movement range of the tube body 2 and is below the paper guide 7, so it is a completely dead space of the recording apparatus.

Next, in the present invention, as explained in FIG. 3, there are two ink supply tubes to the head. Therefore, the tube body is constructed as shown in the four-digit arrangement shown in FIG. As shown in FIG. 4, tubes 15 and 16 are embedded in silicone rubber 17 or the like to form an integral tube body 4. Such a tube body does not prevent the movement of the carriage, has sufficient flexibility, and can efficiently combine a plurality of tubes without taking up space. Furthermore, even if the inner tubes 15 and 16 are made of a material with somewhat lower elasticity, the outer rubber body 17 can sufficiently cover the elasticity. It is possible to adopt the one with the lowest rate).

According to the conventional example, these tubes had to have sufficient elasticity and be flexible, so ink evaporation from this tube part could not be ignored, and the problem was caused by air intrusion and dye precipitation. There were problems such as flow path blockage. This is because in order to ensure flexibility, it is necessary to use a tube made of a polymeric material, and the more flexible the material, the higher the water vapor permeability.

Materials with low water vapor permeability, including the aforementioned vinylidene chloride, could not be used until now because of their poor flexibility, but now they can be used by the method of the present invention. As shown in FIG.
This can be easily achieved by pouring more silicone rubber 17 and hardening it.

The following features of the present invention are shown in FIG. 1 (aL (b), (eL
(Dl) The platen means 6a to 6e shown in FIG. 1 are detached from the frames 30a and 30b together with the shaft 6f by the lever 20 shown in FIG. Since liquid ink is used, it is necessary to take into account the ease of cleaning and maintenance in the unlikely event that the ink spills.In the present invention, the platen and paper guide are removable, so that in case of an emergency The bottom of the recording device can be exposed, making maintenance easier.

Although the individual features of the present invention have been described above, the specific examples shown in the drawings do not limit the present invention, and the application is not limited to the on-demand system.

According to the present invention, all the drawbacks of conventional inkjet recording apparatuses have been eliminated, and a highly reliable recording apparatus can be constructed.

[Brief explanation of drawings]

FIG. 1 is a plan view (a), a front view (b), and a side view (c>, (d)) showing an example of the recording apparatus of the present invention. FIG. Fig. 3 shows an example of the ink supply system of the printing apparatus of the invention. Figs. 4 and 5 show an example of the tube body of the invention. 1. ... Carriage means 2 ... Recording head 3 ... Shaft 4 ... Ink supply tube body 5 ... Ink tank 6 ... Platen means 7... Paper guide 8... Motor 9... 1 11... Lid means 12... Pump means 14... ... Valve means 15 ... Tube 14- 16 ... Tube 17 ... Silicone rubber 18 ... Notch 19 ... Mold 21 ...Glass substrate 22 ...Pressure chamber 26 ...Nozzle 24 ...Reservoir part 25 ...Glass piece 26 ...・Thin glass plate 27 I 28 Protrusion or more Applicant Shinshu Seiki Co., Ltd. Suwa Seikosha 15-347- Unexamined Japanese Patent Publication No. 58-14763 (6) (C) (d) 5 Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (2)

[Claims] (1) A recording head, a carriage means for holding the print head and moving relative to the recording medium, a platen means and a paper guide means for holding the recording medium and transporting the recording medium in a direction perpendicular to the recording direction, and the recording An ink supply tank for supplying ink to the head and an ink supply means for connecting the recording head and the ink supply tank, the platen means and the paper guide means being removable, and the ink co-supply tank An inkjet recording device characterized in that it is a fixed injection type tank installed in an empty space of a main body of the recording device, and the ink supply means is an integrally formed tube made up of a plurality of flexible tubes. (2) The inkjet recording apparatus according to claim 1, wherein an injection type tank is attached to the empty space below the paper guide means.