JPH0416356A - Ink jet recorder - Google Patents

Abstract

PURPOSE:To record stably all the time by providing a rubbing member supported being able to contact with a discharging surface of a record head to which an ink droplet is to be discharged for rubbing the discharging surface with the rubbing member. CONSTITUTION:A record head 101 is released from a capping unit and conveyed to a record head rubbing position. Thereafter, a record head rubbing unit 138 is moved to a position where the unit contacts with a discharging surface 309 of the record head 101, and a motor 346 is rotated so as to clean the record head discharging surface 309 by a record head rubbing member 340. When the cleaning of the discharging surface 309 of the record head 101 is completed, the rubbing unit 138 is released from the discharging surface 309 of the record head 101. After the record head 101 is conveyed to a position where capping is to be performed, the record head 101 is again capped by the capping unit so as to make a stand-by.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an inkjet recording device, and more particularly to an inkjet recording device equipped with means for stably ejecting ink liquid.

[Conventional technology]

In an inkjet recording apparatus, in order to stably perform recording by ejecting ink from a jet, as shown in FIG. Recording head 801
By joining the recording head 801 with the capping means 810, the recording head 801 is sealed from the surrounding atmosphere by putting a lid on the recording head 801, and the air layer at the joining part is removed from the vapor of the ink 807 stored in the ink tank 804. By filling the nozzle with water to bring it to saturated vapor pressure, the ink liquid in the nozzle is prevented from drying and from increasing in viscosity.

However, in such devices, in a low humidity environment or when recording is stopped for a long period of time, an increase in the viscosity of the ink cannot be avoided even if the above-mentioned capping is performed to prevent drying. It is difficult to prevent ink from being ejected from the ink.

In order to eliminate such inconvenience, a pump 805 is provided as a pressurizing means for the ink supply system including the print head 801 as a means for preventing ejection failure of the print head, and the pump 805 is driven by a signal from a control unit 808. By doing so, the ink in the ink circulation vibrators 806a and 806b is pressurized and circulated, and the ink is discharged from all nozzles of the recording head.

Further, an air pump 824 and an air blowing hole 822 are provided as air blowing means. In order to clean the ejection surface 809 from dirt caused by ink discharged from the nozzles of the print head 801, the control unit 808 moves the ink absorber 821 provided in the charring means 810 to the position where it comes into contact with the lower end of the print head 801. After moving the conveying part 825 of the capping means 810 in response to a signal from the air pump 824, the air blower provided in the capping means 810 blows compressed air from the air pump 824 toward the recording head 801 from the hole 822. The ink adhering to the ejection surface 809 of the recording head 809 is blown off and absorbed by the ink absorber 821, or the recording head 8
The problem of the ejection surface 809 of the print head 801 being contaminated by ink adhesion etc. is solved by not spraying the cleaning liquid onto the ejection surface 809 of the print head 801.
The stability of ink ejection in 01 is maintained.

[Problem that the invention is trying to solve]

However, even with such an inkjet recording apparatus, it may not be possible to completely eliminate the effects of contamination caused by ink adhesion to the ejection surface of the recording head.

FIG. 9(a) is a side view showing the configuration of the recording head 801, and FIG. 9(b) is a plan view showing the state of the ejection surface 809. As shown in FIGS. 9(a) and 9(b), minute ink mist is generated when ink droplets 926 are ejected from each nozzle 936 in the recording head 801 configured by a substrate 930 and a top plate 932. Ink droplets 926 ejected from each nozzle of the print head 801 as a result of deposits 927 or deposits 928 caused by foreign matter such as paper dust adhering to and sticking to the ejection surface 809 of the print head.
The ejection characteristics such as the amount, ejection direction, or ejection speed may change, and the diameter of the recording dots on the recording paper may be disturbed.
A problem has arisen in that the recording density varies depending on each nozzle of the recording head.

The present invention has been made in view of the above points, and an object of the present invention is to provide an inkjet recording device that eliminates contamination of the ejection surface of the recording head and allows the recording head to always perform stable recording. .

[Means to solve the problem]

The inkjet recording device of the present invention performs recording by ejecting ink droplets from a recording head, and the inkjet recording device includes a sliding member that can come into contact with an ejection surface of the recording head from which ink droplets are ejected. It has a recording head sliding means that supports the recording head and also slides the ejection surface with the sliding member.

In this case, a cleaning liquid supply means for supplying cleaning liquid to the recording head rubbing means may be provided, and an air blowing means for blowing air against the ejection surface of the recording head may also be provided.

[Effect]

Since the ejection surface of the recording head is rubbed by the rubbing member by the recording head rubbing means, the deposits adhering to and fixed on the ejection surface are removed. In addition to this, when a cleaning liquid supply means and an air blowing means are provided, a cleaning effect and a blowing off effect are added, so that deposits can be efficiently removed.

〔Example〕

Hereinafter, the present invention will be specifically described with reference to the drawings.

FIG. 1 is a perspective view showing an outline of an embodiment of an inkjet recording apparatus of the present invention. Here, 112 is a platen roller driven by a motor (not shown) to convey a recording material (not shown) such as paper, and to form and hold a recording surface.

The recording material in the form of continuous paper or cut paper is stored in the recording head 1.
01 and the platen roller 112 without being pressed against the platen roller 112 by a pinch roller (not shown). The recording head 101 is mounted on a carriage 102, and is moved back and forth in the S direction in the figure along two guide rails 113a and 113b, during which recording is performed on a recording material. The carriage 102 is connected to a shaft 117 of a motor 116 via a heald 119 provided between a pulley 118a and a pulley 118b and a pulley 118a, and reciprocates in the S direction in accordance with the rotation of the motor 116. be exposed.

The recording head 101 has four recording units corresponding to four colors, for example, yellow (Y), magenta (M), cyan (C), and black (B). Those Y, M
, C, and B are provided with supply tubes (pipes) 106aY, 1106a, respectively, in which pumps 105Y, 105M, 105C, and 105B are disposed as means for transporting the ink in the vibrator.

Ink tank 1 via 106aC and 106aB
Ink is supplied from 04Y, 104M, 104C and 104B. Further, each of the recording units is also connected to the corresponding ink tank via a pipe that does not have a gear pump in the middle. Note that, in FIG. 1, only the pipe 106bY for supplying yellow ink is shown for the sake of simplicity.

Reference numeral 110 denotes a capping unit that faces the ejection section of the head 101 at the home position HP of the recording head 115 and can be moved in the f direction and joined to the head 101;
It is constructed similarly to the conventional capping means 810 shown in the figure. 138 is a rubbing unit of the recording head of the present invention.

FIG. 2 is a schematic diagram of an example of the recording head 101 shown in FIG. 1. Hereinafter, embodiments of the present invention will be described as applied to the recording head 101 shown in FIG.

First, the recording head 101 shown in FIG.
5, an electrode 234, a nozzle wall 229, and a top plate 232. Recording ink is supplied into the common liquid chamber 231 of the recording head 101 from an ink tank (not shown) through a pipe 206.

The ink supplied into the common liquid chamber 231 is supplied into the nozzle 236 by capillary action, and is stably held by forming a meniscus at the tip of the nozzle. By energizing the electric/thermal converter 235, the liquid on the surface of the electric/thermal converter is heated, a bubbling phenomenon occurs, and the energy of the bubbling causes droplets to be ejected from the nozzle 229. With the configuration described above, it is possible to manufacture a multi-nozzle inkjet recording head with 128 nozzles or 256 nozzles with a nozzle density as high as 400 dpi.

FIG. 3 is a schematic diagram showing a specific example of the rubbing unit 138 in FIG. 1.

The sliding unit 138 includes a recording head sliding member 340 made of a sponge-like porous resin, a sliding member presser 341, and a housing 342.

A recording head rubbing member 340 that comes into contact with the ejection surface 309 of the recording head 101 is formed integrally with a rubbing member presser 341, and is attached to the housing 342 by a mounting member (not shown). This housing 342 is
It is provided on a moving stage 347 that can move in the f direction perpendicular to 09, and moves in the f direction as the moving stage 347 moves. Further, the housing 342 is slidably attached to a guide rail (not shown) provided vertically on the moving stage 347, so that the housing 342 can move in the V direction parallel to the discharge surface 309.

Further, a slide pin 343 is provided at its lower end. On the moving stage 347, in addition to the housing 342, there are a motor 346 and two gears 344 that mesh with each other.
345° is provided. The gear 345 is attached to a rotating shaft of a motor 346 parallel to the V direction, and the gear 344 is supported by a shaft parallel to the rotating shaft of the motor 346. Since the slide pin 343 contacts the −F surface portion of the gear 344, or the upper surface portion is inclined with respect to the f direction, the sliding unit 138 moves up and down in the V direction in conjunction with the rotation of the motor 346. Make a move. The rotation control of these motors 346 and the movement control of the moving stage 347 are performed by the control section 308.

When performing a rubbing operation on the ejection surface 309 of the recording head 101, the control unit 308 moves the moving stage 347 in the direction of arrow f to move the recording head rubbing member 340 onto the ejection surface 309 of the recording spatula 101. After making contact, motor 3
46. As a result, the gear 344 is rotated via the gear 345, the sliding unit 339 is moved up and down (in the direction of arrow V) via the slide pin 343, and the ejection surface 309 of the recording head 101 is rubbed by the sliding member 340. death,
to clean up.

In other words, as in the present embodiment, the recording head rubbing member 340 made of a sponge-like porous resin or the like is brought into direct contact with the ejection surface 309 of the recording head 101 and mechanically rubbed. Ink mist attached to the ejection surface 309 is also removed. Further, since the change in the ejection surface 309 is restored to the initial state, the ejection surface 309 of the recording head 101
The solvent or dye contained in the ink mist adhering to the recording head 10 sticks to the ejection surface 309, causing the recording head 10
By changing the contact angle between the ejection surface 309 of No. 1 and the ink, the ejected ink droplets are no longer destabilized.

Here, according to the experimental results of the present inventors, the nozzle 400
The recording head 101 shown in FIG. 2 has 256 nozzles per dpi and water 70% diethylene glycol
) 30%, and as the recording head rubbing member 340, porous urethane (trade name: Rubicerclin; manufactured by Toyo Eizai Co., Ltd.) was used. When rubbed 3 to 4 times in the V direction, as shown in Figure 4, when the ejection surface of the recording head was contaminated, the maximum recording density change was approximately 0 compared to before contamination.
．． 1, but due to the cleaning effect of the ejection surface of the print head, the print density change was able to be recovered by about 0102.

FIG. 5 is a flowchart showing an example of control of the inkjet recording apparatus by the control unit 308.

After the recording apparatus is powered on and the recording head 101 is capped by the capping unit 110 (step S1), it is determined whether or not to perform a rubbing operation on the recording head 101 based on an external input signal, etc. (Step S2). If an instruction to perform a sliding operation of the recording head 101 is input,
The recording head 101 is released from the capping unit 110 (step S3), and the recording head 101 is transported to the recording head rubbing position in front of the rubbing unit 138 (step S4). Thereafter, the recording head sliding unit 138 is moved to a position where it comes into contact with the ejection surface 309 of the recording head 101 (step S5), and the motor 346 is rotated to perform the sliding cleaning of the recording head ejection surface 309 by the recording head sliding member 340. (Step S6).

Thereafter, when the rubbing cleaning of the ejection surface 309 of the recording head 101 is completed, the rubbing unit 138 is released from the ejection surface 309 of the recording head 101 (step S7), and after the recording head 101 is conveyed to the capping position where capping is performed. (Step S8), the recording head 101 is capped again by the capping unit 110, and placed in a standby state (Step S9).

If it is determined in step S2 that the recording head is not to be rubbed, it is placed in a standby state, and it is determined whether or not to start recording based on an external signal (step 510).
). When recording, the ink pump is driven (step 511), and after pressurizing the ink in the vibrator 106aY, the air pump is driven (step 512), and air is blown onto the recording head by means (shown at the bottom of FIG. 3). After cleaning the ink remaining on the ejection surface and releasing the capping (step 513), recording is started (step 514). Then, it is checked whether the recording is completed (step 515), and if the recording is completed, the recording head 101 is capped again and placed in a standby state (step 516).

Here, in step S2, a signal instructing whether or not to perform the rubbing operation of the recording head is generated so that the operator can issue the command to the control unit 308 from a console provided with a display member, etc. In a further embodiment, a counter is provided to count and store the number of recording operations performed by the recording head, and the sliding operation of the recording head is performed based on this counter value.
It is also possible to perform control such that the recording head is rubbed once every 00 times.

FIG. 6 is a schematic diagram for explaining the main structure of a second embodiment of the present invention.

In this embodiment, an ink absorber 648 is provided vertically below the rubbing member 340 of the recording head rubbing unit 138, and the ink absorbed by the rubbing member 340 is soaked into the ink absorber 648 to waste ink. The waste ink is collected into a waste ink tank 650 via a hose 649.

Then, by collecting the ink that has soaked into the sliding member 340 of the recording head sliding unit 138 and dissolved the deposits on the ejection surface 309 of the recording head from the sliding member 340, this ink can be used for recording again. This prevents it from re-adhering to the discharge surface 309 of the spatula 101. Since the other configurations are the same as those shown in FIG. 3, the same numbers as in FIG. 3 are given and explanations are omitted.

In this embodiment, the recording head cleaning operation involves moving the recording head to a position facing the rubbing unit 138,
The ejection surface 309 of the recording head by the rubbing unit 138
This is to drive the ink pump 105Y (see FIG. 1) when performing the rubbing cleaning.

In other words, as in this embodiment, the recording head rubbing member 340 made of a sponge-like porous resin or the like is attached to the recording head 101.
When the ink pump 105Y is brought into contact with the ejection surface of the
The ink in 6bY is circulated under pressure in the direction of arrow P to discharge the ink from all nozzles of the recording head 101, and the discharged ink is immersed in a sponge-like recording head rubbing member 340 as a cleaning liquid for cleaning the recording head. It is meant to be absorbed. This has the effect that the solvent or dye in the ink mist that has adhered to and stuck to the ejection surface 309 of the print head can be easily dissolved or removed from the ejection surface 309 of the print head.

In addition, in this embodiment, the recording head sliding member 340
In this embodiment, the ink is supplied as the cleaning liquid by driving the ink pump 105Y, but in another embodiment, for example, the cleaning liquid is supplied by ejecting ink droplets from the recording head onto the recording head rubbing member 340. Alternatively, a cleaning liquid supplying means may be provided separately on the rubbing unit 138, and this cleaning liquid supplying means may supply cleaning liquid other than ink to the recording head sliding member 340. .

FIG. 7 is a flowchart showing an example of control by the control unit 308 in the third embodiment of the present invention.

The apparatus configuration in this embodiment is similar to that shown in FIG. 1, and controls including the air blowing means provided in the capping unit 110. In this embodiment, in order to clean the ejection surface 309 of the print head,
The present invention is characterized in that it operates by combining a non-contact cleaning method and a contact cleaning method for the ejection surface 309 of the print head.

After the power of the recording apparatus is turned on, the recording head 101 is capped by the capping unit 110 (step 571), and whether or not to perform a rubbing operation on the recording head 101 is determined based on an external manual signal or the like (step 572). ). Subsequently, if an instruction to perform a rubbing operation of the print head is input, the ink pump 105Y is driven to push out ink from all nozzles of the print head 101 (step 573), and then the air pump (inactive) is driven. (shown) is driven, and air blowing means (not shown)
After cleaning the ejection surface 309 of the recording head 101 in a non-contact manner (step 574), the recording head is released from the capping unit 110 in step 5.
75), the recording head 101 is transported to the recording head rubbing position in step S76.
Cleaning by contact and rubbing in step 9 is performed (step 578).
. Thereafter, the recording head 101 is released from the rubbing position (step 579), and capping is performed after moving to the capping position (step S80.5).
81).

Note that each step operation S82 to S88 when it is determined in step S2 that the recording head sliding operation is not performed is the fifth step.
Since each step operation SIO to S16 in the figure is the same, the explanation will be omitted.

As described above, in this embodiment, since the print head is first cleaned in a non-contact manner using an air pump, solid deposits such as paper powder that have adhered to the ejection surface 309 of the print head are removed. is removed from the ejection surface 309 in advance, and then rubbing cleaning is performed in which the recording head rubbing unit 138 is brought into contact with the ejection surface 309 of the recording head. As a result, when the recording head rubbing unit 138 cleans the ejection surface 309 of the recording head, the ejection surface 309 may be damaged by solid deposits, or the solid deposits may be packed into the nozzles of the recording head. It is possible to prevent such problems from occurring.

The present invention provides excellent effects particularly in bubble jet recording heads and recording apparatuses among ink jet recording systems.

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 difficult to handle the sheet or liquid path where the liquid (ink) is not held. By applying at least one drive signal that corresponds to recorded information and causes a rapid temperature rise exceeding nucleate boiling to the disposed electrothermal transducer, the electrothermal transducer is caused to generate thermal energy, and the recording is performed. This is effective because it causes film boiling on the heat acting surface of the head, resulting in the formation of bubbles in the liquid (ink) in one-to-one correspondence with this drive signal. The growth of this bubble causes liquid (ink) to be ejected from the contraction nail through the ejection opening to form at least three droplets. When this drive signal is in the form of a pulse, the growth and contraction of the bubbles is carried out immediately and appropriately, so that ejection of liquid (ink) with particularly excellent responsiveness can be achieved, which is more preferable. As this pulse-shaped drive signal, those described in US Pat. No. 4,463,359 and US Pat. No. 4,345,262 are suitable. Incidentally, U.S. Patent No. 431 for the invention regarding the temperature increase rate of the heat acting surface
If the conditions described in specification No. 3124 are adopted,
Even better recording can be performed.

The configuration of the recording head includes, in addition to the combined configuration of ejection ports, liquid paths, and electrothermal converters (straight liquid flow path or right-angled liquid flow path) as disclosed in the above-mentioned specifications, a heat acting section. US Pat. No. 4,558,333 and US Pat. No. 4,459,600 disclose a configuration in which the
The structure described in the specification may be used. In addition, Japanese Patent Application Laid-Open No. 1983 discloses a configuration in which a common slit is used as a discharge part of a plurality of electrothermal converters.
No. 23670 and Japanese Unexamined Patent Publication No. 1, 1982, which discloses a configuration in which a discharge portion is provided with an opening that absorbs pressure waves of thermal energy.
The present invention is also effective with a configuration based on Publication No. 38461.

Furthermore, as a full-line type recording head having a length corresponding to the width of the maximum recording medium that can be recorded by the recording apparatus, the length can be increased by combining multiple recording heads as disclosed in the above-mentioned specification. Either a configuration that satisfies the above requirements or a configuration as a single recording head formed integrally may be used, but the present invention can more effectively exhibit the above-mentioned effects.

In addition, a replaceable chip-type recording head that is attached to the device body enables electrical connection to the device body and ink supply from the device body, or a chip-type recording head that is installed integrally with the recording head itself. The present invention is also effective when a cartridge type recording head is used.

Further, it is preferable to add recovery means, preliminary auxiliary means, etc. for the recording head, which are provided as a configuration of the recording apparatus of the present invention, because the effects of the present invention can be further stabilized. Specifically, these include preheating means for the recording head using a caving means, a cleaning means, a pressurizing or suction means, an electrothermal transducer or another heating element, or a combination thereof. It is also effective to perform a preliminary ejection mode in which ejection is performed separately from printing in order to perform stable printing.

Furthermore, the recording mode of the recording device is not limited to a recording mode in which only the mainstream color such as black is used; the recording head may be configured integrally or in combination with a plurality of recording heads; The present invention is also extremely effective for devices equipped with at least one full color image.

In the embodiments of the present invention described above, the ink is explained as a liquid, but it is an ink that solidifies at room temperature or lower, and is softened or liquid at room temperature, or in the above-mentioned inkjet, the ink itself is heated at 30°C or higher and 70°C. Generally, the temperature is controlled within a range of 0.degree. C. or less so that the viscosity of the ink is within a stable ejection range, so it is sufficient that the ink is in a liquid state when the recording signal is applied. In addition, 8F can be used to prevent the temperature rise caused by thermal energy by using it as energy to adversely change the ink from a solid state to a liquid state, or to prevent ink from evaporating when the ink solidifies when left unused. In any case, the ink is liquefied by applying thermal energy in response to the recording signal and is ejected as a liquid ink, or the ink has already begun to solidify by the time it reaches the recording medium. It is also applicable to the present invention to use ink that is liquefied only by the following steps. In such a case, the ink may be ink as described in Japanese Patent Application Laid-Open No. 54-56847 or Japanese Patent Application Laid-Open No. 60-71260.
The porous sheet may be held as a liquid or solid in the recesses or through-holes of the porous sheet, and may face the electrothermal converter. In the present invention, the most effective method for each of the above-mentioned inks is to implement the above-mentioned film boiling method.

〔Effect of the invention〕

Since the present invention is configured as described above, it produces the effects as described below.

According to the first aspect of the present invention, by rubbing the ejection surface of the recording head with the rubbing member, the contaminated ejection surface of the recording head can be restored by cleaning, so that the ejection surface of the recording head is always stable. This has the advantage that recording can be performed in a stable state.

In the second aspect of the present invention, the rubbing action containing the cleaning liquid is performed, and the solvent and dye attached to the ejection surface are dissolved by the cleaning liquid, so that the above-mentioned effects are further improved.

In the third aspect, since the rubbing cleaning is performed after solid deposits are removed from the discharge surface in advance, in addition to the above-mentioned effects, the solid deposits are removed from the discharge surface during the rubbing cleaning. This has the effect of preventing the surface from being damaged and the inside of the nozzle from becoming clogged.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an outline of an embodiment of the present invention, FIG. 2 is a schematic configuration diagram of the recording head 101 in FIG. 1, and FIG. 3 is a specific example of the rubbing unit 138 in FIG. 1. A schematic diagram showing the
FIG. 4 is a diagram showing the change in maximum recording density before and after performing the sliding operation, FIG. 5 is a flowchart diagram showing the control operation of the first embodiment of the present invention, and FIG. FIG. 7 is a schematic diagram for explaining the main structure of the embodiment, a side view showing a flowchart showing the control operation of the third embodiment of the present invention, and FIG. 9(b) is a plan view. 101... Recording head, 104Y, 104M, 1 tank, 105Y, 105M. B, B. 102-... Carriage, 6aY, 1106a, 106aC. 106bY-... Pipe, 0... Capping unit, 2... Platen roller, 3a, 113b... Guide rail, 6... Motor, 117-... Shaft, 8a, 11
8b=pulley, 9...belt, 138-...sliding unit,
0...Substrate, 231-...Common liquid chamber, 2.
233--Supply port, 4-Electrode, 235--Electrothermal converter, 6-Nozzle, 237--Discharge port, 8-Control unit,
309--Discharge surface. 105C, 105B--Bon 04C, 104B--In indicates the condition of the ejection surface 106a 340--Recording head sliding member, 341--Sliding member presser, 342--Housing,
343-0. Slide pin, 344, 345--Gear, 346--Motor, S1 to S16. S71-S88...Step, 648
---Ink absorber, 649--Waste ink hose, 650--Waste ink tank. Patent applicant Canon Co., Ltd.

Claims (1)

[Claims] 1. In an inkjet recording device that performs recording by ejecting ink droplets from a recording head, a rubbing member can be brought into contact with an ejection surface of the recording head from which ink droplets are ejected. 1. An inkjet recording apparatus comprising: a recording head sliding means for supporting the recording head and for slidingly rubbing the ejection surface with the sliding member. 2. The inkjet recording apparatus according to claim 1, further comprising a cleaning liquid supply means for supplying cleaning liquid to the recording head rubbing means. 3. The inkjet recording apparatus according to claim 1 or 2, further comprising air blowing means for blowing air onto the ejection surface of the recording head. 4. The inkjet recording apparatus according to claim 1, 2 or 3, wherein the recording head is a full line type in which ejection ports are formed over the entire width of the recording area of the recording sheet. 5. The inkjet recording apparatus according to claim 1, 2, 3 or 4, wherein the recording head ejects ink using thermal energy, and includes an electrothermal converter for generating the thermal energy. An inkjet recording device characterized by comprising: