JPH0490358A - Ink jet recording device - Google Patents

Abstract

PURPOSE:To decrease the separating speed of a wiper member immediately before it moves away from ink discharge faces and prevent the ink from scattering from the wiper member to avoid the peripheral contamination by providing a control means to change the rotational speed of the wiper member and the driving speed of a recording head during wiping operation. CONSTITUTION:Upon input of instructions of wiping operation, CPU drive a cap unit 10 to separate a cap member 11 from the ink discharge surface 5A of a head unit 5 and move the head unit 5 to the wiping position of a wiper member 12 at a relatively high first speed set under the instruction and, at the same time, the cap unit 10 is driven to wipe the ink discharge face 5A with the wiper member 12 held in contact therewith. When it is confirmed that a row of ink discharge openings have been wiped clean, the CPU gives a driver the instructions to set a slow second speed and the wiping is continued while decreasing the rotational speed of the head unit 5. This method can prevent the spray of the ink from scattering due to an abrupt rebounding of the wiper member 12 taking place when the wiper member 12 moves away from the ink discharge faces 5A.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an inkjet recording apparatus that performs recording on a recording material by discharging ink from an ink discharge port.

[Prior Art] Conventionally, this type of inkjet recording device has a method for removing ink droplets and dust attached to the ejection surface of a recording head that ejects ink to obtain stable printing and image recording.
Many of them are equipped with a wiper member made of rubber or the like, and configured to wipe the ink ejection surface of the recording head as necessary, for example, before and after a recovery operation.

In particular, in serial printers that perform recording by scanning the recording head in a direction perpendicular to the sheet feeding direction, a wiper member placed near the end of the platen that holds the recording material is moved during wiping ( protrude toward the side of the head that is
A method in which the ink ejection surface of the head is wiped using the moving speed of the carriage has been widely used because it is inexpensive and highly reliable. For example, JP-A-58-
No. 94472 discloses a cleaning (wiper) member that moves forward and backward relative to the recording head, and also reduces the speed at which the recording head enters the cleaner position, thereby reducing the contact speed between the recording head and the cleaner. There is something. By sequentially slowing down the carriage movement speed during high-speed recording in this way, it is possible to ensure the contact state between the wiper member and the recording head.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional example, when the wiper member wipes the recording head, the contact state of both does not change, only the relative speed changes, so the cleaning operation is difficult. When the wiper member is removed from the ink ejection surface of the head in the final stage, the ink wiped from the tip of the wiper member becomes droplets and is splashed around, which may contaminate the recording sheet and the device. Ta.

An object of the present invention is to focus on the above-mentioned conventional problems, and in order to solve the problems, provide an inkjet recording device that can suppress the scattering of ink droplets when a wiper member wipes a head. It's about doing.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a recording head that performs recording by discharging ink from an ink discharge port toward a recording material, and a recording head that performs recording by discharging ink from an ink discharge port toward a recording material, and a recording head that performs recording by discharging ink from an ink discharge port toward a recording material. an elastic wiper member that wipes an ink ejection surface by bringing its tip into contact with an arrayed ink ejection surface, and a rotating means that individually rotates the recording head and/or the wiper member, In an inkjet recording apparatus, the wiper member is brought into sliding contact with the ink ejection surface by driving of a means for wiping, and the driving speed of the recording head or the wiper member by the rotation means is controlled to It is characterized in that it is provided with a control means that is variable during sweeping.

Another aspect of the present invention provides a recording head that performs recording by discharging ink from ink discharge ports toward a recording material, and a tip portion of the recording head on an ink discharge surface on which the ink discharge ports are arranged. It has a wiper member made of an elastic body that is brought into contact and wipes, and a rotating means that rotates the recording head and/or the wiper member individually, and when the rotating means is driven, the wiper member is moved to eject the ink. In an inkjet recording device in which wiping is performed by sliding contact with a surface, the angle between the wiper member and the ink ejection surface changes during the wiping, and becomes smaller as the wiping progresses. It is characterized by the following.

Furthermore, a third aspect of the present invention provides a recording head that performs recording by discharging ink from ink discharge ports toward a recording material, and a tip end on an ink discharge surface on which the ink discharge ports of the recording head are arranged. a wiper member made of an elastic body that wipes the recording head and/or the wiper member by contacting the wiper member; and a rotating means that individually rotates the recording head and/or the wiper member; In an inkjet recording device in which wiping is performed by sliding contact with an ink ejection surface, the angle between the wiper member and the ink ejection surface changes during the wiping, and as the wiping progresses, the angle becomes smaller. In addition, the present invention is characterized in that a control means is provided for making the drive speed of the rotating means variable during wiping.

[Function] According to the present invention, the recording head or the wiper member is rotated by the rotating means to slide the wiper member along the ink ejection surface to perform a wiping operation. Either the driving speed of the above-mentioned rotating means is changed so that the speed at which the wiper member leaves the ink ejection surface is set to the slowest speed, or the angle between the wiper member and the ink ejection surface is adjusted to the progress of wiping. By configuring the wiper member to become smaller as the wiper member moves away from the ink ejection surface, or by implementing both of the above, the resilience of the wiper member to return to its original position due to its elasticity is weakened, causing the ink to scatter. can be prevented.

[Example] Hereinafter, an example of the present invention will be described in detail and specifically based on the drawings.

FIG. 1 shows an example of a facsimile machine to which the present invention is applied. The facsimile apparatus according to this embodiment can be roughly divided into two parts in this figure: document transport system A, optical system B, power supply unit C1, electric circuit board, recording paper transport system E, and decal system, as shown surrounded by two-dot chain lines. F, supply system G and recovery system H
Consisted of. However, here, the document conveyance system A and the optical system B constitute a document reading section that reads the document image from the document 1, and as a basic operation of the facsimile machine,
When a document 1 is set on the document feed table 2 of the document conveyance system A during transmission or copying, the document 1 is moved by a row of rollers (rollers R1-R2, R3) driven by a drive means (not shown).
・R4) is carried in the direction of the arrow. Then, the document information is transferred from the document 1 to the optical system B (lamp L1, lamp L1,
The condenser lens Le
The signal is transmitted to line CCD3 by line CCD3, where it is converted into an electrical signal and read.

In the case of receiving or copying, in the sheet conveying system E, the recording sheet 4 wound into a roll shape is sequentially conveyed along the path shown by the thick line by a roller array driven by a drive means (not shown). Ink is ejected from the ejection ports of the head unit 5 based on the document information at a predetermined print line along the transport path, and printing is performed.

The ink is ejected from the head unit 5 by a so-called bubble jet method in which air bubbles are generated in the ink using heat generated by an electrothermal converter (not shown), and the ink is ejected by the pressure change of the air bubbles. It is something that is done.

In addition, the power supply section C receives input of AC power from the outside and supplies power to necessary locations. The electric circuit board has a microcomputer system as its center, as well as the circuits described below to control the functions and operations of each part of this device, as well as the connection and disconnection with the transmission line, as well as the control of image information signals. It is equipped with input/output circuits. Supply system G is head unit 5
The recovery system H includes a leaning means and a capping means necessary for making the head unit 5 perform stable ejection.

Next, the configuration of the parts related to the recovery operation of the recovery system H and decal system F according to the present invention will be explained with reference to FIGS. 1 and 2. Here, the head unit 5 has ink ejection ports arranged over the entire recording width of the recording sheet 4.
It is a so-called full-line head, and is elongated in the direction perpendicular to the plane of the paper, and the entire head is rotatably supported around the head shaft 5B. In addition, in FIG.
A stepping motor 8 is used to rotate the head unit 5 around the head unit 5, and 8 is a belt for driving the stepping motor.

In addition, with respect to the above-mentioned head unit 5, 10 is a recovery system H.
This is a cap unit that is provided in the head unit 5 and performs capping and wiping operations for the head unit 5. The cap unit 10 has an ink ejection surface 5A of the head unit 5.
A cap member 11 having a length sufficient to cover the
．． The wiper member 12 is provided at a position as shown in FIG. 2, and is swingably supported by a frame shaft 13 attached to one end of the cap unit 10.

Note that the swinging motion of the cap unit 10 is performed by the frame axis 1.
3, the stepping motor 7 for rotating the head unit 5 and the stepping motor for driving the cap unit IO are both controlled by the control means described later. Speed is controlled along with drive timing.

FIG. 3 shows a control system of an inkjet recording apparatus according to the present invention. 21 is its central processing unit (CPU), and the CPU 21 reads the original and performs the head unit 5.
At the same time, various operations by the recovery system H described above are controlled. That is, 22 is a ROM in which control procedures etc. for each mode of the apparatus are stored, and 23 is an RA used for reading from the original 1 and storing recorded data.
It is M. Therefore, the CPU 21 drives the document transport system A and the sheet transport system E, and causes the document reading section (optical system) B to read the document 1 according to instructions inputted from an operation panel (not shown). The head driver 24 is driven based on the information, and ink is ejected from the head unit 5 to perform recording.

In addition, when capping the head unit 5 after recording or performing a recovery operation on the head unit 5, the head shaft drive motor 7 is driven via the driver 25 in the procedure described later, and then the head shaft drive motor 7 is driven by the driver 25. A frame shaft drive motor 27 is driven and controlled via 26. The control operation at that time will be explained below along with the procedure in accordance with FIG. 4 with reference to FIG. 2.

First, the capping state of the head unit 5 during non-recording when it is not in use is not shown in these figures, but the head unit 5 is in the position shown in (A) in FIG. The ink ejection surface 5A of the head unit 5 is kept covered. For example, when an operation is performed to forcibly discharge ink together with air bubbles from an ink discharge port provided on the ink discharge surface 5A as a recovery operation, the ink remaining on the ink discharge surface 5A is then wiped off. As necessary, the wiping operation by the wiper member 12 is performed as follows.

FIG. 2(A) shows the retracting operation of the cap unit 10. The rotation in the direction of the arrow is caused by the frame shaft drive motor (
When a series of recovery operation or sweeping operation commands are input to the CPU 21, the CPU 21 follows the procedure shown in FIG.
First, in step Sl, the cap unit 10 is driven to attach the cap member 11 to the ink ejection surface 5 of the head unit 5.
Pull away from A.

Next, in step S2, the driver 25 is instructed to a relatively high first speed to drive the stepping motor 7, and the head unit 5 is guided to the wiping position by the wiper member 12 as shown in FIG. 2(B). (At the same time, in step S3, the cap unit IO is driven in the direction of the arrow, that is, in the direction from the cap member ll side position toward the recording area side, and in step S3
4, wait for the wiper member 12 to come into contact with the ink ejection surface 5A of the head unit 5. Then, in step S5, wiping is performed. For example, the state shown in (B) is confirmed by a timer held by the CPU 21, and the ink ejection port array is further wiped as shown in (C) in FIG. When this is confirmed, the CPU 21 instructs the driver 24 to operate at a second speed, which is a lower speed, and performs wiping while lowering the rotational speed of the head unit 50 (step S6).

That is, this suppresses the wiping speed of the wiper member 12, and prevents ink droplets from scattering around the wiper member 12 due to sudden bounce when the wiper member 12 separates from the ink ejection surface 5A. . In particular, in this embodiment, the wiper member 12 is located at a distance from the recording sheet 4, and in addition, the cleaning direction is such that the direction of bounce by the wiper member 12 is on the opposite side to the side on which the recording sheet 4 is held. Since the head is moved in the direction from the cap member side to the recording area side, there is no risk of the recording sheet 4 being soiled, and it is possible to eliminate the risk of contaminating surrounding members.

Next, when the cleaning is completed, the cap unit 10 is rotated to the retracted position (step S7) as shown in FIG. The first speed is returned to the first speed, and the recording position is set as quickly as possible. In this way, if it is confirmed in step S9 that the head unit 5 has been guided to the recording position by a sensor (not shown), the rotation of the head unit 5 is stopped in step SIO, and the series of wiping operations is completed. .

In addition, in the above explanation, we have described the wiping operation that is performed after the rotation operation that forcibly ejects ink from the ink ejection surface, but such wiping operation can also be used just before the start of recording or during the recording process to remove ink mist. This is also performed to remove wetting of the ink ejection surface due to adhesion and dust that accidentally adheres, and the operating procedure at that time is the same as described above, and its explanation will be omitted.

In addition, in the embodiments described above, the rotation speed was controlled when rotating the head unit, but in the first embodiment, the head unit was kept at a predetermined wiping position and It is also possible to perform a corresponding operation to regulate the relative wiping speed. Furthermore,
Application of the present invention is not limited to cases where a full-line type inkjet recording head is used, but can be applied to any type of inkjet recording head configured to perform a wiping operation by rotating the recording head or wiper. Needless to say, the present invention can be widely applied to serial type recording devices in which a head is mounted on a carriage and recording is performed by the movement of the head.

As described above, 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 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. 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 this bubble causes the liquid (ink) to be ejected through the ejection opening to form a small droplet (at least one droplet).If this drive signal is in the form of a pulse, the growth and contraction of the bubble will occur immediately and appropriately. Because it will be
Particularly responsive liquid (ink) ejection can be achieved,
More preferred. This pulse-shaped drive signal is described in U.S. Pat. Nos. 4,463,359 and 4,345,262.
Those described in the specification are 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.

The configuration of the recording head includes, in addition to the combination 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. The present invention also includes configurations using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose configurations in which the bending region is arranged. In addition, Japanese Patent Application Laid-Open No. 5-1999 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 when the configuration is based on Japanese Patent No. -138461. That is, regardless of the form of the recording head, according to the present invention, 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 with the serial type shown above, the recording head is fixed to the device body, or by being attached to the device body, electrical connection to the device body and ink supply from the device body are possible. The present invention is also effective when using a replaceable chip type recording head or a cartridge type recording head in which an ink tank is integrally provided in the recording head itself.

Further, it is preferable to add recovery means for the recording head, preliminary auxiliary means, etc., which are provided as a configuration of the recording apparatus, to the present invention, because the effects of the present invention can be further stabilized. Specifically, these include capping means for the recording head, cleaning means, pressure or suction means, preheating means using 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.

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. That is, for example, the recording mode of the recording apparatus is not limited to a recording mode for only a mainstream color such as black, but may also be a recording mode in which the recording head is configured integrally or in a combination of multiple colors, The present invention is also extremely effective for devices equipped with at least one full color by color mixture.

Additionally, in the embodiments of the present invention described above,
Although ink is described as a liquid, it is an ink that solidifies at room temperature or below, but softens or liquefies at room temperature, or in an inkjet method, the ink itself is
Generally, the temperature is adjusted within the range of 0°C or more and 70°C or less so that the viscosity of the ink is within the stable ejection range, so even if the ink is in a liquid state when the recording signal is applied. Bye. In addition, the temperature increase caused by thermal energy can be actively prevented by using the energy to change the state of the ink from a solid state to a liquid state, or ink that solidifies when left standing is used to prevent ink evaporation. In any case, the ink is liquefied by applying thermal energy in accordance with the recording signal, and the liquid ink is ejected, or the ink has already begun to solidify by the time it reaches the recording medium. The present invention is also applicable when using ink that is liquefied only by energy. The ink used in this case is
Publication No. 4-56847 or JP-A-60-71260
It may also be in a form where it is held as a liquid or solid in the recesses or through holes of a porous sheet and faces the electrothermal converter, as described in the above publication. In the present invention, the most effective method for each of the above-mentioned inks is to implement the above-mentioned film boiling method.

In addition, in addition to being used as an image output terminal for information processing equipment such as a computer, the inkjet recording apparatus of the present invention may also take the form of a copying machine combined with a league, etc., or a facsimile machine having a transmission/reception function. It may also be something.

[Effects of the Invention] As described above, according to the present invention, the wiper member is brought into sliding contact with the ink ejection surface of the head by the rotating means that rotates the recording head and/or the wiper member individually. In the inkjet recording apparatus, a control means is provided that changes the driving speed of the wiper member or the recording head by the rotating means during wiping, so that the wiper member is not tripped immediately before it leaves the ink ejection surface. By slowing down the speed, ink can be prevented from scattering from the wiper member and staining the surrounding area, and accidents such as interfering with the device's electrical wiring or reading optical system or staining the recording material can be prevented. Ru. In addition, at other times, the drive speed can be kept high, so there is no need to reduce the overall speed for wiping, and in particular, due to the standardization of communication methods such as in facsimile machines, the wiping operation can be This is suitable for applications where the time required for processing is limited.

According to another aspect of the present invention, the angle formed between the wiper member and the ink ejection surface changes during wiping, and becomes smaller as the wiping progresses. Further, by combining the above-mentioned embodiments of the present invention with the later-mentioned other embodiments, even more reliable effects can be expected.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an example of the configuration of a facsimile machine to which the present invention is applied, FIG. 2 is an explanatory diagram of a wiping operation according to the present invention, and FIG. 3 is a block diagram showing the configuration of a control circuit according to the present invention. FIG. 4 is a flowchart showing the procedure of control operation during wiping according to the present invention. 4... Recording sheet, 5... Head unit, 5A... Ink ejection surface, 5B... Head shaft, 7... (For head shaft drive) Stepping motor, 10... Cap unit, 11 ... Cap member, 12 ... Wiper member, 21 ... CPU. 22...ROM. 23...RAM 24-26...Driver 27... (For driving cap unit) Stepping motor. Figure 3 of the 70-tube prisoner of the Pi11 circuit in the first work of “The Cows in the e9F”

Claims (1)

[Scope of Claims] 1) A recording head that performs recording by discharging ink from ink discharge ports toward a recording material, and a tip portion of the recording head that is brought into contact with an ink discharge surface on which the ink discharge ports are arranged. a wiper member made of an elastic body, and a rotating means for individually rotating the recording head and/or the wiper member, and the wiper member is moved onto the ink ejection surface by driving the rotating means. In the inkjet recording apparatus in which wiping is performed by sliding contact, a control means is provided for varying the driving speed of the recording head or the wiper member by the rotating means while wiping the ejection surface. An inkjet recording device featuring: 2) The inkjet recording apparatus according to claim 1, wherein the control means controls the driving speed of the rotation means to be reduced in the latter half of the cleaning. 3) A recording head that performs recording by discharging ink from ink discharge ports toward a recording material, and an elastic body that wipes the recording head by bringing its tip into contact with the ink discharge surface on which the ink discharge ports are arranged. and a rotating means for individually rotating the recording head and/or the wiper member, and the wiper member is brought into sliding contact with the ink ejection surface by driving of the rotating means for wiping. In the inkjet recording apparatus, the angle between the wiper member and the ink ejection surface changes during the wiping, and becomes smaller as the wiping progresses. Recording device. 4) A recording head that performs recording by discharging ink from ink discharge ports toward a recording material, and an elastic body that wipes by bringing its tip into contact with the ink discharge surface on which the ink discharge ports of the recording head are arranged. and a rotating means for individually rotating the recording head and/or the wiper member, and the wiper member is brought into sliding contact with the ink ejection surface by driving of the rotating means for wiping. In the inkjet recording apparatus, the angle between the wiper member and the ink ejection surface changes during the wiping and becomes smaller as the wiping progresses, and the rotation means An inkjet recording apparatus characterized by comprising a control means for varying the driving speed of the inkjet recording apparatus during wiping. 5) The inkjet recording according to any one of claims 1 to 4, wherein the recording head is of a full line type in which the ink ejection ports are arranged in accordance with the recording width of the recording material. Device. 6) The recording head is equipped with an electrothermal converter as an energy conversion means for ejecting ink toward the recording material, and the heat converted by the electrothermal converter is used to generate bubbles in the ink. 6. The inkjet recording apparatus according to claim 1, wherein the inkjet recording apparatus generates a bubble and discharges the ink in accordance with a pressure change caused by the foaming. 7) The apparatus is configured such that the recording head comes into contact with the wiper member during a path in which the recording head moves from a position facing a cap member covering an ejection port surface of the head to a position facing the recording material. Claims 1 and 3 characterized in that
, 4. The inkjet recording device according to any one of 4.