JPH03227647A - Liquid jet recorder and wipeoff device user for the former - Google Patents

Abstract

PURPOSE:To prevent an ink jet surface from becoming wetted or fouled by ink or prevent the ink jet failure due to the solidification of ink by employing an elastic ink absorber as a member to wipe the ink jet surface of a recording head and at the same time, making the surface to be wiped water-repellent. CONSTITUTION:A wipeoff device 6 is composed of an ink corrosion-resistant, highly absorptive almost square ink absorber 7 and an absorber holder 8 which holds the ink absorber 7. The device 6 heaves up, only when a wipeoff action is required, in an arrow Y' direction, and descends in the arrow Y' direction and is kept in a standby position, if a sequence of wipeoff actions for recording heads 1A to 1D is completed. At the time of starting the recording, a cap member 4 becomes separated from the discharge surface 2 of the recording head 1 and a carriage moves in an arrow X direction. Consequently, the recording heads 1 come in contact with the ink absorber 7 of the wipe-off device 6 which has heaved up from a standby position. After that, an ink mark left on the part with which the peripheral part 4A of the cap member 4 comes in contact is wiped off by the water repellent layer 9 of the ink absorber 7.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a liquid jet recording device having a wiping device.
More specifically, the present invention relates to a liquid jet recording apparatus that wipes and removes recording liquid droplets and dust adhering to the vicinity of the ejection openings of a recording head that ejects recording liquid, and a wiping device used therein.

[Conventional technology]

In conventional liquid jet recording devices of this type, ejection energy is applied to the recording liquid (hereinafter referred to as ink) in the liquid path by an ejection energy generating means provided in the liquid path, and ink droplets are ejected from the ejection opening. Recording is performed on the recording material using the inks, but when recording is not performed, the water in the ink evaporates from the ejection ports, so to prevent this,
It is known that a cap member is provided to cover the ink ejection surface of the print head outside the print area.

In addition, when ink is ejected, ink droplets are formed on the ink ejection surface due to small droplets that bounce off the recording material or other causes, so in order to wipe away the wetness caused by such ink, wiping is necessary. There are devices that are provided with an elastic plate, devices that are provided with an ink absorber, and devices that are provided with both an ink absorber and an elastic plate separately.

[Problem to be solved by the invention]

However, if only the cap member is provided as described above, the ink adhering to the ejection surface during the recording operation may accumulate around the ejection port, blocking the ejection port and causing ejection failure, or correct ejection may not be obtained. This causes the flight direction to be bent and the landing position of the droplet to shift. Therefore, as mentioned above, a cleaning device is installed, but
If you wipe with a rubber plate, etc. every time you finish recording a sheet, a stable wiping function cannot be achieved due to tolerances related to the size of the rubber plate and environmental fluctuations, and ink may accumulate due to unwiped parts. However, the same non-discharge or incorrect discharge as in the conventional case still occurs.

Star - 2 LJ To the word 2 To the trowel, Sodo's synonym No. 0 In the case of recording a color image using ink of a different color, the ink was transferred onto the rubber plate during the first wiping. There is a possibility that color mixing may occur between the ink and the ink of the next head when the next head is wiped. Therefore, there are devices that wipe with an absorbent material that absorbs the ink, but this method lacks durability, and during long-term use, the ink ejection surface becomes stained by the absorbent material.

Furthermore, although it is sufficient to include both the above-mentioned absorbent body and the rubber plate, this complicates the cleaning procedure and increases the size and cost of the device.

The purpose of the present invention is to focus on and solve the above-mentioned conventional problems (and to prevent color mixing from occurring on multiple recording heads with a single wiping member). An object of the present invention is to provide a liquid jet recording device that is as compact as possible and can be obtained at low cost, and a wiping member used therein.

[Means to solve the problem]

In order to achieve such an object, the present invention provides a liquid ejection recording apparatus that includes a wiping member that wipes a liquid ejection surface of a recording head that ejects liquid and has an ejection energy generating element. Composed of an elastic liquid absorber,
It is characterized in that at least a portion of the surface of the liquid absorber involved in cleaning the recording head is made water repellent.

Further, the wiping member acts on the liquid ejection surface of a recording head used in a liquid jet recording device, and has a liquid water-repellent section at least in a portion that first comes into contact with the ejection surface. It is characterized by being a liquid absorber.

[Function] According to the present invention, the member for wiping the ink ejection surface of the recording head is made of an elastic ink absorber, and at least a portion of the surface involved in the wiping is made water repellent. In addition to being able to have both the wiping and ink absorbing functions in one member, the synergistic effect improves the duration of the wiping effect and prevents the wiping that is left behind as in the conventional method. In addition, by using the present invention in conjunction with a multi-color recording head,
It is also possible to prevent color mixing.

Further effects of the present invention are particularly preferred in the embodiments represented in FIGS. 2 and 5, the details of which will be understood from the following description.

〔Example〕

Embodiments of the present invention will be described in detail and specifically below based on the drawings.

FIG. 1 shows an embodiment of the invention. Here, LA, I
B, 1c and ID are cyan, magenta, and
These print heads 1 perform printing by ejecting yellow and black ink, and these print heads 1 are mounted on a carriage (not shown) and move, for example, in the direction of arrow X, and during the movement, the respective ejection surfaces The ink of the above-mentioned color is ejected from the ink ejection opening 3 provided in the recording medium 2 onto a recording material (not shown). The ejection surfaces of these recording heads have been previously treated to be water repellent. In other words, the surface to be cleaned is a water-repellent surface. 4 is a cap member attached to the cap holder 5 with the same spacing as the recording heads IA to ID, and when the carriage returns to the home position and no recording is performed, the cap holder 5
is moved upward to bring the corresponding cap member 4 into contact with the ejection surface 2 of each recording head 1, keeping the area around each ink ejection port 3 in a sealed state, and if necessary performs a recovery operation by suctioning ink. It can be performed.

Reference numeral 6 designates a wiping device according to the present invention, which includes an ink absorber 7 having a substantially rectangular shape that is corrosion resistant and highly absorbent to ink, and an absorber holder 8 that holds this ink absorber 7. It is moved in the Y and Y' directions shown by arrows by a vertical drive mechanism (not shown). The wiping device 6 is installed upright at a position outside the recording area, a little away from the cap member 4, and rises when the carriage moves in the X direction, thereby cleaning the absorbent body 7 as shown in FIG. It is maintained in contact with the ink ejection surface 2 of each recording head 1 as shown in FIG. 9 is a water-repellent layer formed in advance on one surface of the ink absorber 7, that is, the surface on the recording head 1 side, by water-repellent treatment, etc.;
When wiping is performed by the wiping device 6 as shown in FIG. It functions like a rubber wiping plate and acts to wipe away ink droplets.

By the way, in the recording head 1, as described above, a so-called wetting state occurs on the ejection surface due to minute ink droplets 10. FIG. 3A shows the state of the ejection surface 2 immediately after being released from capping by the cap member 4. In this case, an ink mark 10A is attached corresponding to the shape of the peripheral portion 4A of the cap member 4. Further, FIG. 3B shows the wet state of the ejection surface 2 that occurs during recording. In this case, the size of the ink droplet 10 also varies, and the higher the proportion of the solid area occupied by the recording, the easier it is to wet the ink droplet, but in general, a small droplet is several μm, and a large droplet is several hundreds μm. Furthermore, the height of the ink droplets 1O also differs depending on the type of ink and the condition of the orifice plate portion 2A of the ejection surface 2, but if water-repellent treatment has been applied, the height of the ink droplet 10 is about 1 μm at a small size, and about 10-odd μm at a large size. It is.

Next, the wiping operation by the wiping device 6 configured as described above will be explained with reference to FIGS. 1 and 2.

As mentioned earlier, the wiping device 6 rises in the direction of the arrow Y only when a wiping operation is necessary, and moves the recording head IA-
After completing a series of wiping operations for the ID, it descends in the direction of arrow Y' and remains in a standby state. Therefore, first, at the start of recording, the cap member 4 is separated from the ejection surface 2 of the recording head 1, and the carriage (not shown) moves from the home position to the arrow
When the recording head 1 moves in this direction, the recording head 1 comes into contact with the absorber 7 of the wiping device 6 that has risen from the standby state one after another. Then, as shown in FIG. 3A, the ink marks 10A attached to the area where the peripheral portion 4A of the cap member 4 comes into contact are wiped off with the water-repellent layer 9 of the absorber 7, as shown in FIG. In this way, recording is performed by ejecting ink one after another from the individual recording heads IA to In in the wiped state shown in FIG. 3C.

Further, ink droplets 1o as shown in FIG. 3B attached to the periphery of the ink ejection opening 3 during the arrangement operation may be removed once the recording head 1 has printed a predetermined amount or for a predetermined period, for example. After returning to the home position, a sequence for moving in the X direction again can be incorporated into the control section of the host device (thereby, wiping can be performed in the same manner as described above).

In this way, according to this embodiment, the water-repellent layer provided on one side of the absorber 7 functions well as a conventional rubber wiping plate, so that not only the ink droplets 10 but also the attached Even dirt can be wiped away, and furthermore, the absorber 7 absorbs a trace amount of unwiped ink layer that could not be wiped off with a conventional rubber wiping plate, thereby performing effective wiping without leaving any ink residue. I was able to do that. In addition, since the amount of ink absorbed by the absorber 7 itself is small, it is no longer possible to absorb the ink completely and cause the ink to be smeared onto the ejection surface, which is the case with conventional methods, and the durability of the absorber 7 can be reduced. I was able to extend my life.

In this embodiment, since the sliding surface of the recording head has been subjected to water-repellent treatment in advance, the frictional resistance during wiping is reduced, and there is also the advantage that the durability of the other side can be improved. In this case, the partner water repellent is preferably of the same kind or made of the same material.

In addition, in this example, the presence of a water repellent agent on the entire surface prevents ink leakage on the surface of the liquid absorber and a decrease in ink retention, and the capillary action area created by the water repellent surface at the boundary with the absorber. This has the additive effect of increasing the ink absorption capacity.

The various conditions under which this example was carried out are shown below.

Absorber: Thickness 5. Omm±0.1 Width 15. Omm tO, 1 free length
8. Omm±0.1 Penetration amount 2. Omm±0.3 Water repellent treatment...Only one side, water repellent layer thickness 20μm Contact angle: 90° Wiping freeze a: ln11mm/cap + 91
1 recording head used: 400 dpi 12g nozzle wiping sequence = every 8 lines recorded (4 times for 1 A4 sheet) Although silicone-based water repellent was used, this is not limited to hydrophobic materials such as fluorine thread. It is sufficient as long as it has the following effect. However, when forming the material, it is preferable that it be difficult to penetrate into the absorbent body.

Regarding the wiping speed, it was confirmed that as the speed increases, the wiping effect tends to decrease especially due to slip-through, but there is no problem if the wiping speed is 300 mm/sec or less.

As a result of an durability test conducted on 30,000 A4 size sheets under the above conditions with solid black recording at a recording ratio of 100% and maximum wetting amount, some small ink residue was observed on the ejection surface in the latter stage. However, there was no significant effect on ejection, such as twisting or non-ejection at -time. In addition, although an environmental test was conducted under the same conditions, high temperature/high humidity (32
, 5℃ 790%) to low temperature/low humidity (15, 0℃ 710%)
), satisfactory results were obtained.

Next, a second example will be explained.

In this example, water-repellent layers 9 are formed on both sides of the absorbent body 7, as shown in FIG. That is, according to this example, it is possible to sweep in both directions when the carriage moves back and forth,
In the first embodiment, it was possible to wipe the ink only when moving from the home position in the X direction, but in this embodiment, the ink trace 10A due to capping is wiped out when moving in the X direction, and a predetermined amount of recording is When the absorbent body 7 returns to its home position after performing a cleaning operation, the water repellent layer formed on the other side of the absorbent body 7 can perform a wiping operation.

Therefore, the dry ejection operation that has conventionally been performed as a recovery operation can also be performed at this time.
There is no need to perform a wiping operation (this not only increases the overall recording speed, but also enables double wiping due to the reciprocating movement of the carriage, further increasing the wiping effect. .

FIG. 5 shows a third embodiment of the present invention. In this example, absorber 7
A water-repellent layer 9 is formed on a part of the surface to be wiped by a water-repellent treatment or the like, and the part indicated by a dot in this figure is the part where the water-repellent layer 9 is formed. Furthermore, here, ψ indicates the angle that this water-repellent layer forming portion (2) makes with the ejection surface 2 of the recording head 1 when the recording head 1 moves in the X direction. Further, in this example, as a preferred example, the ejection surface 2 is subjected to water repellent treatment to form the water repellent surface 2B, but it is also possible to use a recording head in which such a water repellent surface 2B is not formed. Of course.

The wiping device configured in this way can be effective even when the amount of ink is large due to wetting of the ejection surface 2. For example, as in this example, the ejection surface 2 is treated with water repellent treatment. If so, it is relatively difficult for ink droplets 10 to accumulate on that surface. However, this example is effective even when there is a lot of wetness.
In this example, when the accumulated ink exceeds the water-repellent layer forming part I as shown by the arrow A, it will be absorbed by the part (hereinafter referred to as the ink-absorbing part) where the water-repellent layer is not formed. It's Nishide. Of course, if there is a lot of wetting, the remaining ink can be absorbed from the bottom surface of the absorber 7 as shown by arrow B.

In order to further improve this effect, the height of the water-repellent layer must be increased by 5 μm.
m to 100 μm, and in practical terms, it may be designed within the range of 30 μm to 5000 μm.

According to this embodiment, since two absorption paths can be obtained, ink can be sufficiently absorbed and wiped even if, for example, a plurality of recording heads are provided to eject different colors. That is, when the first recording head IA is wiped and then wiped one after another, the amount of ink that accumulates in the water-repellent layer forming portion 1 is small, so color mixing does not occur. In addition, in this example, the water-repellent layer forming part (2) was provided on one surface of the absorbent body 7, but in accordance with the second embodiment, water-repellent layer forming parts were provided near the edges of both surfaces. You can also do it like this.

In addition, when forming a water-repellent layer on the absorbent body mentioned above, it is necessary to form a water-repellent layer on the block of the absorbent body by water-repellent treatment, etc., and then cut it into multiple layers. In addition, the water-repellent layer may also be formed by pasting an elastic hydrophobic film instead of applying a water-repellent agent, etc. The ink can be squeezed out from the absorbent body according to the present invention by suction means or suppressing means as necessary, or a heater can be provided inside the absorbent body to dry the ink. The cleaning method may also be performed obliquely to the direction of movement of the head.

The present invention provides excellent effects particularly in bubble jet type recording heads and recording apparatuses among liquid jet recording types. This is because such a system can achieve higher recording density and higher definition. The reason for this is that the ejection characteristics due to bubble generation are greatly impaired due to poor cleaning, and there are cases where adhered substances occur on the ejection surface due to thermal effects, but the cleaning effect of the present invention specifically solves these problems. Because you can.

As for typical configurations and principles thereof, it is preferable to use the basic principles disclosed in, for example, US Pat. No. 4,723,129 and US Pat. No. 4,740,796. This method can be applied to both the so-called on-demand type and continuous type, but especially in the case of the on-demand type, it is necessary to arrange the liquid (ink) in accordance with the sheet and liquid path that hold it. By applying at least one drive signal that corresponds to recorded information and causes a rapid temperature rise exceeding nucleate boiling to the electrothermal transducer, the electrothermal transducer generates thermal energy, and the recording head This is effective because it causes film boiling on the heat acting surface of the drive signal, resulting in the formation of bubbles in the liquid (ink) that correspond one-to-one to this drive signal. The growth and contraction of the bubble causes liquid (ink) to be ejected through the ejection opening to form at least one droplet. It is more preferable to use this drive signal in a pulse form, since the growth and contraction of bubbles can be carried out immediately and appropriately, making it possible to eject liquid (ink) with particularly excellent responsiveness. This pulse-shaped drive signal is;
"U.S. Pat. No. 4,463,359-, U.S. Pat. No. 4,345
262 is suitable. Furthermore, if the conditions described in US Pat. No. 4,313,124 concerning the invention regarding the temperature increase rate of the heat acting surface are adopted, even more excellent recording can be performed.

As for the configuration of the recording head, in addition to the configuration described above (straight liquid flow path or right angle liquid flow path), US Pat.
The present invention also includes configurations using the specifications of No. 333 and US Pat. No. 4,459,600. In addition, JP-A-59-123670 discloses a configuration in which a common slit is used as a discharge part of a plurality of discharge energy generation means, and a hole that absorbs pressure waves of thermal energy is disclosed. The effects of the present invention are also effective even with a configuration based on Japanese Patent Application Laid-open No. 138461/1985 which discloses a configuration corresponding to the discharge section. In other words, regardless of the form of the printhead, printing can be performed reliably and efficiently.

Furthermore, the present invention can be effectively applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium that can be recorded by a recording apparatus.

Such a recording head may have either a configuration in which the length is satisfied by a combination of a plurality of recording heads, or a configuration in which a single recording head is formed in one direction. In addition, even the serial type shown above can be installed on the main body of the device, allowing for electrical connection to the main body of the device and supply of ink from the main body of the device.Replaceable chip type recording heads. Alternatively, the present invention is also effective when using a cartridge type recording head that is integrally provided with the recording head itself.

〔Effect of the invention〕

As described above, according to the present invention, the member for wiping the ink ejection surface of the recording head is composed of an elastic ink absorber, and at least a part of the surface of the ink absorber that is involved in wiping is Since it is made water repellent, it is possible to combine the wiping function of a blade with the ink absorption function in one member, which was not possible with conventional wiping devices composed of only ink absorbers. It is possible to effectively prevent non-discharge or skewed recording due to ink wetting or staining, or non-discharge due to solidification of ink. Furthermore, in the case of a color recording apparatus using a plurality of liquid jet recording heads, it is possible to prevent color mixing of ink, and it is also possible to contribute to the simplification, miniaturization, and cost reduction of the wiping device itself.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing the configuration of the first embodiment of the present invention, Fig. 2 is an explanatory diagram of the wiping operation by the wiping member shown in Fig. 1, and Figs. 3A, 3B, and 3C are records. A front view showing the state of ink stains on the head ejection surface and the state after cleaning. FIG. 4 is a configuration diagram of an absorber according to a second embodiment of the present invention. FIG. 5 is a third embodiment of the present invention. FIG. 6 is an explanatory diagram of a wiping operation according to an example. 1, LA, IB, IC, ID...recording spatula 2
...Discharge surface, 3...Ink discharge port, 4...Cap member, 4A...Surrounding part, 5...Cap holder, 6...Sweeping device, 7...Absorber, 8... Absorbent holder, 9... Water repellent layer, 10... Ink drop, 10A... Ink trace, ■... Water repellent layer forming part, ■... Ink absorbing part. Do, the first evil god J-shiki sound M-sai and you sweep I-shiki! Figure 2

Claims (1)

[Scope of Claims] 1) A liquid ejection recording device including a wiping member for wiping a liquid ejection surface of a recording head that ejects liquid and has an ejection energy generating element, wherein the wiping member is an elastic liquid absorbing member. 1. A liquid jet recording apparatus, characterized in that at least a part of the surface of the liquid absorber involved in wiping the recording head is made water repellent. 2) The liquid jet recording device has a plurality of recording heads,
The liquid jet recording apparatus according to claim 1, wherein the wiping member wipes the plurality of recording heads. 3) The liquid jet recording apparatus according to claim 1 or 2, wherein at least a part of the surface of the liquid absorber that is involved in wiping is made water repellent by coating with a water repellent agent. 4) The liquid jet recording apparatus includes a thermal recording head as the recording head, the ejection surface of which has been previously treated to be water repellent, and which has an electrothermal transducer that applies thermal energy to liquid or solid ink to cause film boiling. Claims 1 to 3
The liquid jet recording device according to any one of the above. 5) A wiping member that acts on the liquid ejection surface of a recording head used in a liquid jet recording device, the wiping member main body having a liquid water-repellent section at least at the part that first comes into contact with the ejection surface. A wiping member characterized by being a liquid absorber. 6) The wiping member according to claim 5, wherein the water-repellent portion is the entire one side of the wiping member body. 7) The wiping member is a thermal recording head whose ejection surface has been treated to be water repellent in advance and has an electrothermal transducer that applies thermal energy to liquid or solid ink to cause film boiling. 6. The cleaning member according to 5 or 6.