JPH03189163A - Ink jet recorder - Google Patents

Abstract

PURPOSE:To an assembly property of an apparatus by recovering ink discharge function certainly by a method wherein after rubbing a porous material in which a capillary phenomenon appears remarkably against a discharge surface of a head, said porous material is brought into contact with the porous material for specified time. CONSTITUTION:After confirming that a head is not located at HP position, a rotary material 32 is rotated counterclockwise by 90 deg. by driving a motor 23, and a porous material 33 is turned to a front. After the porous material 33 faces the front, a head 5 is so controlled as to return to the HP position by moving in the B' direction by driving a carriage driving motor 22. A front discharge part of the head comes in contact with the porous material to be rubbed at that time, paper powder, dust or ink reservoir or the like being causes for giving bad influences on discharge are removed. By keeping a state wherein the head 5 is pushed against the porous material 33 herein, ink is absorbed from the discharge mouth by a capillary phenomenon between the discharge part of the head and the porous material, and the thickened ink, bubbles, etc. are discharged outside from the discharge mouth in proportion with contact time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an inkjet recording device.

[Prior Art] In recent years, devices such as personal computers and word processors have become widespread, and there are various methods for printing out manually-generated information using these devices, such as the wire tod method, thermal transfer method, and inkjet method. A recording method has been developed. These recording methods perform predetermined recording on a conveyed recording sheet, and there are significant differences between the respective recording heads.

In inkjet recording devices, ejection failure occurs due to paper powder, dust, or additional ink adhering to the ejection part of the print head, or ink clogging in the ejection part on the front of the head. Conventionally, it has been practiced to provide a cleaning means for removing.

An example of such a conventional ink ejection function recovery device will be described below with reference to the drawings.

FIG. 2 is a perspective view of the ink ejection function recovery device;
FIG. 4 is a front view thereof, FIG. 4 is a side view thereof, and FIG. 5 is a schematic elevational view of the worm wheel portion shown in FIG.

2 to 5, a pump 9 is attached to a frame 15, and a worm wheel 12 is mounted on a piston 9A of the pump 9 as shown in FIG. Worm wheel shaft 1 integrated with
2^ is supported by the lid 16. When the worm 14A integrated with the worm wheel 14 is driven to rotate, the worm wheel 12 meshed with the worm 14A rotates. Here, a worm wheel cam 13 is formed on the worm wheel 12, and when the worm wheel 12 rotates, the worm wheel cam 13 hits a fixed cam 138, the worm wheel 12 is moved downward, and the pump 9 is rotated. Piston 9A is pushed down.

The pump 9 is driven by this pushing down on the piston 9, and a negative pressure suction force is generated to suck ink. Note that the return of the piston 9^ (stopping the operation of the pump 9) is performed by a spring (return spring) within the pump 9, etc.

The forward and backward movement of the cap means 7 is controlled by a worm wheel cam 13.
This is done by the interaction between an inner cam (not shown) and a cap means. A cap rubber 30 is provided on the front surface of the cap means for sealing and press-contacting the ejection surface of the recording head. Note that the capping operation and ink recovery operation described above are normally performed when the carriage is at the home position.

The blade IO moves forward by a certain amount when the cap means 7 is brought into the released state by the rotation of the cam 13. The movement of the blade IO is controlled by a combination of the forward and reverse rotation of the cam 13, the blade stop lever 35, and the movement of the carriage. Further, the scraping mechanism 11 removes ink films and the like on the front surface of the recording head that cannot be removed by the blade IO.

In this way, in conventional inkjet recording devices,
There are provided an ink ejection function recovery device that closes the ink ejection port surface of the print head with a cap to eject ink, and a device that scrapes the front surface (ejection portion) of the print head with a flexible blade or the like.

[Problems to be Solved by the Invention] However, although it is possible to prevent clogging of ink ejection orifices with conventional ink ejection function recovery devices for inkjet recording devices, the configuration, control, etc. are very complicated. However, compared to other recording devices, there were problems such as an increase in cost.

SUMMARY OF THE INVENTION An object of the present invention is to provide an inkjet recording apparatus that can reliably restore the ink ejection function with a simple configuration, improve the assembly efficiency of the apparatus, and reduce its price.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides an inkjet recording apparatus that performs recording by flying recording droplets from a recording head to a recording medium, in which eight movements of the recording head are performed. a recording liquid absorbing means comprising a porous body for absorbing recording liquid, and controlling the recording liquid absorbing means and/or the 8-movement means I to control the surface of the recording head having recording liquid ejection ports. The apparatus is characterized by comprising a control means for bringing the surface having the recording liquid ejection port into contact with the recording liquid absorbing means for a predetermined period of time after the recording liquid absorbing means moves the recording liquid while being rubbed by the recording liquid absorbing means.

[Function] After rubbing a porous material in which capillary phenomenon is noticeable against the ejection surface of the head, the porous material and the ejection surface are brought into contact for a predetermined period of time. The ejection surface of the head is cleaned by the porous body, and the amount of recording liquid necessary for ejection recovery can be sucked from the ejection opening of the head due to capillary action when the porous body comes into contact with the porous body.

[Example] Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a perspective view showing the configuration of an embodiment of the present invention.

First, the overall configuration of the recording device will be explained. Reference numeral 1 denotes a recording sheet made of paper or plastic sheet, and a plurality of sheets 1 stacked in a cassette or the like is fed by a paper feed roller (not shown).
The paper is supplied one by one. This recording sheet 1 is transported by a pair of first conveying rollers 3 and a second pair of conveying rollers arranged at a constant interval.
It is transported in the direction of arrow A by a pair of transport rollers 4. Reference numeral 5 denotes an inkjet recording head for recording on the recording sheet 1, and ink is discharged from its discharge ports in accordance with an image signal. This recording head 5 (is mounted on the carriage 2 and is connected to the gear 1 drive motor 22 via the gear 1 drive belt 8 and the pulley. Therefore, by driving the carriage drive motor 22, the carriage 2 It is configured to reciprocate along the two-force τ guide shaft 31. Note that IIP is the home position.

With this configuration, the recording head 5 records an ink image by ejecting ink onto the recording sheet l according to the image signal while moving in the direction of the arrow B, and when the recording is completed, the pair of conveying rollers 3.4 is driven to convey the recording sheet 1 by one line in the direction of arrow A. By repeating this operation, predetermined recording is performed on the recording sheet 1.

32 is a rotary body that includes a porous body 33 and is rotated by the drive motor 23. When the porous body 33 is not facing the front, it does not come into contact with the recording head 5 and the porous body 33 is facing the front. Sometimes, depending on its thickness, it is placed at a position where it comes into contact with the recording head 5.

FIG. 6 is a block diagram showing the configuration of the control section of this embodiment.

Here, the control device 24 includes CPII, ROM, RA
It is in the form of a micro combinator with M etc.
Each part of this embodiment, such as the carriage drive motor 6 and the rotating body drive motor 23, is controlled according to the processing procedure stored in the ROM.

Next, if paper powder, dust, or thickened ink adheres to the ejection part of the recording head 5, or ejection failure occurs due to ink clogging in the ejection part, etc., and an operation to recover the ink ejection function is necessary, perform this operation. An example operation will be explained.

FIG. 7 is a flowchart showing the processing procedure of this embodiment stored in the ROM of the control device 24. The operation of this embodiment will be explained below based on this flowchart.

When an ink ejection function recovery operation command is input to the control device 24 in step S1, it is first checked whether the head is waiting at the position HP in the figure (step 52).

If the head 5 is at the position IP in the figure, the carriage drive motor 22 moves the head 5 in the direction B in the figure to temporarily retreat (step 53).

After confirming that the head 5 is not in the HP position in this way, the motor 23 is driven to rotate the rotating body 32 counterclockwise by 90 degrees, so that the porous body 33 faces forward (step S4). .

After the porous body 33 faces forward, in step S5, the carriage drive motor 22 is driven to control the head 5 to move in the B° force direction and return to the HP position in the figure.

At this time, the ejection part on the front surface of the head comes into contact with the porous body and is rubbed, and paper powder, dust, ink pools, etc. that adversely affect ejection are removed.

Here, when the head 5 reaches the IIP position, the head 5 and the porous body 33 are kept in a pressed state as described above, but depending on how long this state is maintained, The amount of ink suction is determined.

In other words, ink is sucked from the ejection port by capillary action between the ejection portion of the head and the porous body, and thickened ink, air bubbles, etc. are discharged outside the ejection port in proportion to the contact time. Therefore, in order to manage the amount of suction, a timer is used to manage the suction time.

That is, in step S6, the timer is reset and the suction time (contact time) is counted (step 57). After a predetermined time has elapsed, the head 5 is temporarily retracted in the direction B in the figure (step Sa). Next, the rotating body 32 is rotated 90° clockwise to retract the porous body 33 (step S9), and the head 5 is returned to the position IP (in the figure) (step 510). In this way, the series of ink ejection function recovery operations is completed. By controlling as described above, it is possible to easily and reliably clean the surface of the head 5 where the ejection port is located, eliminate ink clogging, etc. in one series of operations.

Here, the experimental results of the ink suction ability of the porous body are shown in FIG. In FIG. 8, the horizontal axis shows the type of porous material, and the vertical axis shows the amount of ink suction.

The porous material used in the experiment was one type of blotting paper.

3 types of non-woven fabric, 1f dust-free paper! , 3 types of filter paper, 8 types in total. For these eight types, materials generally called porous bodies were randomly selected. Among these, nonwoven fabric A has the highest suction force, with an ink pulling force of 1.0 g or more, and even filter paper B, which has the lowest suction force, has an ink pulling force of 0.2 g.
It was found that the ink lifting force was 5 g.

As shown in Figure 9, this experimental result shows that the porous material is
Cut into pieces of 0m+nx 160mm and add 10mm to the ink.
This is the result of measuring the amount of ink sucked after 10 minutes of immersion.

In the conventional mechanical ink ejection function recovery operation that uses negative pressure to suction, the suction amount is about 0.05 g. This also proves that the ink suction ability of the porous body can be fully utilized for the ink ejection recovery operation.

Therefore, by rubbing a porous material in which capillarity occurs prominently against the discharge part of the head and then bringing it into contact,
Stable ink ejection can be easily and reliably obtained. 1 in the figure while the head 5 is in contact with the porous body 33.
When returning to the 1P position (step S5 mentioned above),
The porous body may be chamfered in order to make the return smooth.

Further, the type of porous body does not necessarily have to be special, but if a porous body whose fiber direction is aligned in the ink traveling direction is used, the suction force can be increased.

In this embodiment, if ejection failure occurs one after another and the ink ejection function recovery operation is performed frequently in a short period of time, there is a risk that the ink retention amount of the porous body will become saturated and the recovery ability will decrease. , as shown in FIG. 10, a polygonal prism rotating body 32
By arranging a plurality of porous bodies 33 on alternate sides and using the porous bodies 33 alternately, the frequency at which the amount of ink held by the porous bodies becomes saturated can be drastically reduced.

It should be noted that the present invention provides excellent effects particularly in bubble jet recording heads and recording apparatuses among ink jet recording systems.

This is because such a system can achieve higher recording density and higher definition.

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 the continuous type, but especially in the case of the on-demand type, it can be arranged in accordance with the sheet holding the liquid (ink) and the liquid path. The electrothermal converter that is
Generating thermal energy in the electrothermal transducer and producing film boiling on the thermally active surface of the recording head by applying at least one drive signal that corresponds to recorded information and provides a rapid temperature rise above nucleate boiling. As a result, bubbles in the liquid (ink) can be formed in a one-to-one correspondence with this drive signal, which is effective. The growth and contraction of the bubble causes liquid (ink) to be ejected through the ejection opening to form at least one drop. If this drive signal is in the form of a pulse, bubble growth and contraction will occur immediately and appropriately.
Particularly responsive liquid (ink) ejection can be achieved,
More preferred. This pulse-shaped drive signal is described in U.S. Pat. No. 446:1:159, U.S. Pat.
Suitable are those described in No. 62 specification. 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.

The configuration of the recording head includes, in addition to the combination configuration of ejection ports, wave paths, and electrothermal converters (straight liquid flow path or right-angled liquid flow path) as disclosed in the above-mentioned specifications, a heat acting part. The present invention also includes configurations using US Pat. No. 4,558,333 and US Pat. No. 4,459,800, which disclose configurations in which the bending area is disposed. In addition, Japanese Patent Application Laid-Open No. 1989-5 discloses a configuration in which a common slit is used as a discharge part of a plurality of electrothermal converters.
No. 9-123670 and Japanese Patent Application Laid-Open No. 59/1989 which discloses a configuration in which a discharge portion is made to correspond to an opening that absorbs pressure waves of thermal energy.
The effects of the present invention are also effective even if the structure is based on the publication No.-138461. In other words, regardless of the form of the recording head, recording 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 as a single recording head formed integrally. 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.

Further, it is preferable to add a preliminary auxiliary means for the recording head, which is provided as part of the configuration of the recording apparatus, to the present invention because the effects of the present invention can be further stabilized. Specifically, for example, preheating using an electrothermal converter, a separate heating element, or a combination thereof is effective for stable recording.

In addition, regarding the type and number of recording heads installed, for example, in addition to one type that corresponds to single-color ink, there is also a plurality of recording heads that correspond to multiple inks with different recording colors and densities. It may be something that can be done.

In addition, the inkjet recording apparatus of the present invention may take the form of an image output terminal for information processing equipment such as a computer, a copying apparatus combined with a reader, etc., or a facsimile apparatus having a transmitting/receiving function. It may be something.

[Effects of the Invention] As described above, the present invention can perform an ink ejection function recovery operation with a simple control and drive system that involves simply rubbing a porous body against the ejection part of the head and then bringing it into contact. Moreover, the ink ejection ability can be reliably restored, and the cost is lower and the ease of assembly is improved compared to conventional inkjet recording apparatuses.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a perspective view of an inkjet recording device according to an embodiment of the present invention, FIG. 2 is a perspective view of a conventional ink ejection recovery device, and FIG. 3 is a front view of the device shown in the second diagram. 4 is a side view of the second illustrated device, FIG. 5 is a partially enlarged elevational view of the worm wheel cam of the second illustrated device, and FIG. 6 shows the configuration of the control section of the embodiment illustrated in the first figure. Block diagram, Figure 7 is a flowchart showing the procedure to be processed by the control device, Figure 8 is an explanatory diagram showing the experimental results of the ink suction ability of the porous body, Figure 9 is an explanatory diagram of the experimental method, The figure is a configuration diagram of a porous body and a rotating body. DESCRIPTION OF SYMBOLS 1... Recording sheet, 2... Carriage, 3... First conveyance roller, 4... Second m-th feed roller, 5... Recording head, 7... Cap means, 8... Belt , 9... Pump, 10... Blade, 11... Scraping mechanism, 12... Worm wheel, 12^... Worm wheel shaft, 13... Worm wheel cam, 138... Fixed Cam, 14... Worm wheel, 14^... Worm, 15... Frame, 16... Lid, 22... Carriage drive motor, 23... Rotating body drive motor, 24... Control Apparatus, 30... Cap rubber, 31... Guide shaft, 32... Rotating body, 33... Porous body. Figure 4 15 Figure 3 Figure 5 Figure 7

Claims (1)

[Claims] 1) An inkjet recording device that performs recording by ejecting recording droplets from a recording head to a recording medium, comprising: means for moving the recording head; and a porous body for absorbing recording liquid. The recording liquid absorbing means, and the recording liquid absorbing means and/or the moving means are controlled to move the surface of the recording head having a recording liquid ejection port while being rubbed by the recording liquid absorbing means, and then the recording An inkjet recording apparatus comprising: a control means for bringing a surface having a liquid ejection port into contact with the recording liquid absorption means for a predetermined period of time. 2) The recording liquid absorbing means includes a plurality of members made of the porous body, and the control means selects one member from among the plurality of members and absorbs the recording liquid into the member. 2. The inkjet recording apparatus according to claim 1, wherein after the surface having the ejection ports is moved while being rubbed, the inkjet recording device is brought into contact with the surface for the predetermined period of time.