JPH03248850A - Ink jet recorder - Google Patents

Abstract

PURPOSE:To prevent mixing of printing colors at discharge port and perform cleaning at the discharge port positively by a method wherein an ink reservoir is installed at a point adjacent to a wiper member, which is brought into contact with the ink discharge port surface, and inks from various recording heads are discharged to the ink reservoir. CONSTITUTION:While recording heads 1 are moving towards a recovery device 4 by the action of the force of a carriage 3, by the force of the wiper member 5 located at a position possible to be in touch with the discharge surface of the recording head 1, dust and the like attached to the discharge port surface are wiped off, and further when the wiper reaches the point of capping means 6, the discharge port surface is tightly sealed by the action of the capping means 6. Then the pressure difference generated within the recovery device 4 due to the working of the pump and the like, is transferred to the inside capping means 6, the ink flow is formed in the liquid channel in the discharge port of the recording head 1, thereby the air bubbles, dust and the like existing in the liquid channel are removed. While the recording head 1 is moving toward the recording region and when each of the recording head 1 passes in front of each wiper member, 5 each discharge port surface is wiped by a recording head, and the ink of each color is discharged from each recording head toward the inside of the ink reservoir 12.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to an inkjet recording apparatus that is configured to perform recording with a plurality of recording heads and has a wiper member that can come into contact with the ejection port surface of each recording head. Regarding.

[Conventional technology]

2. Description of the Related Art Recording devices such as printers, copiers, and facsimile machines are configured to record images consisting of dot patterns on recording materials such as paper and thin plastic plates based on transferred image information.

The recording device may be an ink diode type,
It can be divided into wire dot type, dot type, laser beam type, etc. Among these, inkjet type (inkjet recording device) uses recording liquid (
The printer is configured to fly small droplets of ink (ink) into the air and attach them to a recording material for recording.

Since this inkjet recording device is a non-impact type, it is suitable for color recording and high-speed recording.

2. Description of the Related Art In a full-color type ink jet recording apparatus that uses inks of a plurality of colors having different hues or an inkjet recording apparatus that uses a plurality of inks of different densities, recording is performed using a plurality of recording heads for each different ink.

The fourth issue is a schematic perspective view showing a conventional example of an inkjet printing apparatus equipped with a plurality of printing heads.

In Fig. 4, 1 indicates different recording liquids (inks).
Discharge and record? ! 2 is a plurality of ink tanks containing recording liquids (inks) of different hues or different concentrations; 3 is a carriage carrying the recording head 1 and reciprocating in the main scanning direction; 4; 5 is a recovery device for restoring and maintaining the ink ejection performance of the recording head 1 to a normal state; 5 is a wiper member made of a flexible elastic material provided on the side of the recovery device 4; 6 is a wiper member provided on the side of the recovery device 4;
is a capping means provided as a part of the recovery device 4; 7 is a conveyor roller that conveys the recording material such as paper or a thin plate of Plus Deck in the sub-scanning direction; and 8 is a conveyor roller that follows the conveyor roller 7 to convey the recording material. 1 is an auxiliary roller for general feeding; 9 is a pressing member (spring) for properly guiding the recording material in close contact with a guide member such as a platen; 10 is a guide shaft for movably guiding and supporting the carriage 3; 11 is a guide shaft for movably guiding and supporting the carriage 3; Recording materials made of recording paper, plastic thin plates, etc. are shown respectively.

The wiper member 5 is made of an elastic material such as a plate-shaped silicone rubber, and is arranged so that it can move forward and come into contact with the ejection port surface (the face surface on which the ejection portion is formed) of the recording head 1. There is.

The capping means 6 is disposed so as to be in close contact with the ejection port surface of the recording head 1, and in addition to capping the ejection port surface in close contact, the capping means 6 utilizes the pressure difference generated inside the recovery device 4 when the capping means 6 is in close contact with the ejection port surface. The recording head 1 is configured to generate an ink flow inside the ejection opening (liquid path) of the recording head l.

When the inkjet recording device is powered on and a recording signal is sent from a post computer, etc., the recorded +
, (After '11 is conveyed to a predetermined position by conveyance-7, the carriage 3 is driven and the recording head 1 scans the recording head) to eject ink onto the recording material 11. Recording is performed by

In this case, due to air bubbles in the ink or dust attached to the ejection port surface, ink may not be ejected from the print head 1 even though a print signal is applied, or the ink ejection direction may be misaligned. Poor ejection, such as
Therefore, recording defects may occur.

When such a discharge failure occurs, a recovery operation command is issued based on the user's judgment or automatically by a sensor or the like.

When a recovery operation command is issued, the recording head 1 is first conveyed to the recovery device 4 by the carriage 3.

At this time, before the recording head 1 reaches the capping means 6, the wiper member 5, which has been moved to a position where it can come into contact with the ejection orifice surface of the recording head 1, wipes off dust etc. attached to the ejection orifice surface. It will be done.

Thereafter, the recording head 1 moves to a position facing the capping means 6, and the ejection port surface thereof is sealed by the capping means 6.

Therefore, the pressure difference generated inside the recovery device 4 by a pump (not shown) is transmitted to the capping means 6 to generate an ink flow in the liquid path in the ejection port of the recording head 1, and the ink flow causes air bubbles in the liquid path. and dust are removed (cleaned).

Thereafter, the wiper member 5 returns to the recording area and performs the recording operation, but at this time the wiper member 5 has retreated to a position where it does not come into contact with the recording belly button 11, and the wiper member 5 does not come into contact with the ejection port surface.

[Technical Problems to be Solved by the Invention] However, in the conventional inkjet recording apparatus described above, when a recording failure occurs due to air bubbles in the ink or dust adhering to the ejection port surface, the recovery device 4 performs a recovery operation. Since the recovery operation was completed when the camping means 6 discharged (suctioned, etc.) the ink from the ejection port, ink that was not sucked up to the capping device often remained on the ejection port surface, and this remaining ink This poses a technical problem in that it acts on the ejected ink droplets (such as surface tension) and causes recording defects such as bending the ejection direction.

In order to improve this problem, consideration was given to adding a mechanism to the recovery device 4 to remove only the ink remaining on the ejection port surface, but this would make the recording device complicated and prone to failure. In addition, there was a technical problem of increasing costs.

Furthermore, a method of adding an operation of wiping the ejection port surface with the wiper member 5 after the ink suction from the ejection port by the capping means 6 was also considered, but adding this operation alone is not enough to reduce the In the case of the recording apparatus, there is a problem in that ink adhering to the wiper member 5 enters the liquid path from the ejection opening of another recording head, resulting in color mixing.

In order to solve this problem, it has been considered to use individual wiper members for each recording head, but this would make the structure of the recording device complex and large, and would also increase costs. there were.

The present invention has been made in view of the above-mentioned technical problem, and even when printing using multiple print heads, the ejection port surface of each print head is ensured without causing color mixing of ink at the ejection section. An object of the present invention is to provide an inkjet recording device that can be cleaned frequently.

(Means for Solving the Problem) The invention according to claim 1 is configured to perform recording with a plurality of recording heads that discharge recording liquid of different colors or different concentrations, and that is in contact with the discharge port surface of the recording head. In an inkjet recording device having a wiper member capable of
An ink reservoir is provided at a position adjacent to the wiper member,
During a predetermined operation, after the wiper member is brought into contact with the ejection port surface, ink is ejected from each print head into the ink reservoir, even when printing using a plurality of print heads. An object of the present invention is to provide an ink jet recording apparatus that can reliably clean the ejection port surface of each print head without causing color mixing of ink at the ejection portion.

In addition to the above-mentioned configuration, the present invention is characterized in that the wiper member and the ejection port surface come into contact with each other in the order of the recording head having the highest brightness of the recording liquid during a predetermined operation. An object of the present invention is to provide an inkjet recording device that can reliably prevent color mixing and deterioration of image quality due to the color mixing.

〔Example〕

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

The first part is a schematic perspective view of an embodiment of an inkjet recording apparatus according to the present invention.

In Figure 1, 1 indicates different recording liquids (inks).
A plurality of recording heads (inkjet heads) that eject and perform recording; 2 a plurality of ink tanks each storing recording liquid (ink) of a different hue or concentration, and supplying ink to the corresponding recording head 1; ,3
Reference numeral 4 denotes a carriage carrying the recording head 1 and reciprocating in the main scanning direction; 4 a recovery device for restoring and maintaining the ink ejection performance of the recording head 1 to a normal state; and 5 a recovery device provided on the side of the recovery device 4. a wiper member of flexible elastic phase, 6 and capping means provided as part of the recovery device 4;
8 is a conveyance roller that conveys the recording material such as paper or a thin plastic plate in the sub-scanning direction, 8 is an auxiliary roller that follows the conveyance roller 7 and generally feeds the recording material, and 9 is a guide for the recording material such as a platen. A holding member (spring) that guides the carriage 3 properly by closely contacting the member; 0 is a guide that guides and supports the carriage 3 in a movable manner; Reference numerals 12 and 12 respectively indicate ink reservoirs that are disposed next to the wiper member 5 and have openings that can face the ejection port surface of the recording head 1.

Each recording head 1 is an inkjet recording head that discharges ink using thermal energy, and is equipped with an electrothermal converter for generating thermal energy.

Further, the inkjet recording head 1 performs recording by ejecting ink from the ejection ports by the growth of bubbles due to film boiling caused by thermal energy applied by the electrothermal converter.

The wiper member 5 is made of, for example, a plate-shaped silicon rubber,
It is made of an elastic material such as, and is disposed so that it can move forward and come into contact with the ejection port surface (the face surface on which the ejection portion is formed) of the recording head 1.

The capping means 6 is disposed so as to come into close contact with the ejection port surface of the recording head 1, and in addition to camping in close contact with the ejection port surface, the capping means 6 utilizes the pressure difference generated inside the recovery device 4 when the capping means 6 is in close contact with the ejection port surface. The recording head 1 is configured to generate an ink flow inside the ejection opening (liquid path) of the head 1.

When the recording device is powered on, when a recording signal is sent from a host computer, etc., the recording material 11 is conveyed to a predetermined position by the conveyor 1 and the carriage 3 is driven. Recording is performed by ejecting ink from the recording head onto the recording material 11 while scanning with the recording head 1.

In this case, because there are air bubbles in the ink and dust attached to the ejection port surface, ink may not be ejected from the print head 1 even though a print signal is applied, or the ink may not be ejected in the direction in which the ink is ejected. Ejection failure (and therefore recording failure) may occur, such as smearing, but if such ejection failure occurs or is likely to occur, it may be determined by the user or automatically by a sensor, etc. Then, a recovery operation command is issued.

When a recovery operation command is issued, the following series of recovery operations are performed.

2 FIG. 2 is a flowchart showing the sequence of this recovery operation.

In FIG. 2, when a recovery operation command is issued, the recording gutter 1 is moved by the carriage 3 toward the recovery device 4.

During this movement, in step S1, before each recording head 1 reaches the camping means 6, the wiper member 5, which has been moved to a position where it can contact the ejection port surface of the recording head 1, Dust etc. adhering to the discharge port surface are wiped off.

In this case, the wiper member 5 may be a fixed type installed at a position where it always contacts the discharge port surface, or it is normally in a retracted position where it does not contact the discharge port surface, but it can be driven forward when necessary. It may also be a movable type that moves to a position where it contacts the discharge port surface.

When the recording head 1 moves further and reaches a position facing the capping means 6, the ejection port surface thereof is sealed by the capping means 6 in step S2.

Next, in step S3, the pressure difference generated inside the recovery device 4 is transmitted to the inside of the capping means 6 by a pump (not shown), etc., to generate an ink flow in the liquid path in the ejection port of the recording head 1, and to remove the ink. Air bubbles, dust, etc. in the liquid path are removed (cleaned) by the flow.

This cleaning operation of the ejection port can be performed by either a suction method in which the ink is sucked out from the ejection port using negative pressure suction force, or a pressurization method in which the ink in the ink supply system is pressurized and the ink is pushed out from the ejection port. .

After the above recovery operation (cleaning) of the discharge port is completed,
In step S4, the camping means 6 is separated from the recording head 1, and the recording head 1 is moved toward the recording area.

When moving to the recording area, the recording gutter 1 is moved by the wiper member 5.
and passes in front of the ink reservoir 12.

Therefore, in step S5, the adhered ink is removed by wiping the respective ejection port surfaces by utilizing the relative movement when each recording head 1 passes in front of the wiper member 5.

Next, in step S6, ink is ejected from each recording head 1 into the ink reservoir 12 a preset number of times.

After completing the above sequence, the recording head 1 returns to the recording area and recording is resumed.

In the recovery operation described above, in the wiping in step S5, one wiper member 5 sequentially wipes the ejection opening surface of the gutter 1 for recording multiple (for example, four) recording heads, so that some ink is left at the ejection opening of a certain recording head l. Although color mixture occurs, in step S7 immediately after that, ink is ejected from each recording head 1 to the ink reservoir 12 a predetermined number of times, so that the mixed color ink is also discharged at the same time.

Therefore, even if color mixing occurs at the discharge port during wiping,
The recording material 11 is not recorded with mixed color ink.

Note that the above sequence includes the operation of suctioning ink from the ejection ports 5 with the ejection port surface of each recording head 1 sealed with the capping means 6, but the present invention does not require such camping and suction. It is also possible to implement a sequence that does not include the following operations.

That is, during the recording operation, the paper 1'η generated from the paper etc. as the recording material 11 may adhere to the exit surface of the recording head. It can also be omitted.

FIG. 3 is a flowchart showing a sequence in which the capping operation is omitted.

In FIG. 3, when a wiping operation command for the ejection orifice surface of the recording head 1 is issued, the recording spatula 1'1 is moved toward the recovery device 4, and in step Sll, the front of the wiper member 5 on the way is moved. Wipe the ejection port surface of each recording head 1 using the relative movement as it passes, removing paper dust and other (
flJ kimono removed.

Next, when the recording head 1 reaches a position facing the capping means 6 of the recovery device 4, it is stopped there, and in step S12, the recording head 1 is driven to remove the canopy 6 from the ejection opening of each recording head 1. The ink is ejected a predetermined number of times toward the inside of the printing means 6.

After ink ejection is stopped, the print head is moved toward the print area, and in step 313, the wiper member 5 wipes the ejection port surface of each print head l using this return movement. .

Subsequently, in step S4, ink is ejected from the ejection ports of each recording head 1 toward the ink reservoir 12 a predetermined number of times, and the series of operations ends.

The sequence described in Part 3 can be performed periodically during the recording operation.

In the second series of recovery operations, the operations of wiping the ejection opening surface of each of the recording holes 1-1 with the - number of wiper members 5 and ejecting ink from each recording head l to the - number of ink reservoirs 12. When performing this for each of a plurality of recording heads having inks of different hues or different densities, it is more effective to perform the ink in descending order of brightness in order to prevent ink color mixing at the ejection section.

According to the embodiment described above, there are a plurality of recording heads 1 that use ink of a plurality of different hues or different densities.
In an inkjet recording apparatus having a flexible wiper section A5 that contacts the ejection port surface of each recording head 1 during a predetermined operation, an ink reservoir 12 is provided at a position adjacent to the wiper member 5, and the ink reservoir 12 is provided at a position adjacent to the wiper member 5, and The wiper member 5 is brought into contact with each ejection port surface during a predetermined operation, and then ink is ejected from each recording head 1 into the ink reservoir 12 a predetermined number of times, so when using multiple colors of ink. However, it is possible to obtain an inkjet recording device that can reliably perform the nozzle recovery operation and wiping operation for each recording without causing ink color mixing at the ejection port, and can form stable and high-quality recorded images. Ta.

In addition, an inkjet recording apparatus was obtained that can realize the excellent functions described in ``2'' at a low cost and with a highly reliable configuration.

In each of the above embodiments, the present invention will be explained by taking as an example a case in which the present invention is applied to a serial type inkjet recording apparatus in which a recording gutter 1 is mounted on a carriage 3 and moves over a recording material 1. However, the present invention can be implemented in the same manner in an ink side recording apparatus using a full multi-type recording head, and similar effects can be obtained.

INDUSTRIAL APPLICATION This invention brings about an excellent effect especially in the recording apparatus of the Hubble Jet recording method among the inkjet recording methods.

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 in the case of the men-demand type, it is especially applicable to the sheet or liquid path where the liquid (ink) is held. Is it arranged? ) to the electrothermal converter,
By applying at least nine driving signals corresponding to the recording information and providing rapid temperature rise exceeding nucleate boiling point, thermal energy is generated in the electrothermal transducer and the thermal active surface of the recording throat is generated. This is effective because it can form bubbles in the liquid (ink) in one-to-one correspondence with this driving signal by causing film boiling.

Due to the growth and contraction of these bubbles, liquid (
ink) to form at least -. droplets.

If this drive signal is in the form of a pulse, bubble growth and contraction will occur immediately and appropriately, so liquids with particularly excellent responsiveness (
Ink) can be ejected, 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.

Further, 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.

In addition to the configuration of the combination of ejection ports, liquid paths, and electrothermal converters (straight liquid flow path or right-angled liquid flow path) as disclosed in each specification mentioned above, the configuration of the recording head is as follows. U.S. Pat. No. 4,558,333 discloses a configuration in which a heat acting portion is disposed in a bending region, U.S. Pat. No. 44
A configuration using the specification of No. 59600 is also included in the present invention.

In addition, a configuration is disclosed in which a common sliding slit is used as a discharge portion of the electrothermal converters for a plurality of electrothermal converters. The present invention is also effective with a structure based on JP-A No. 123670 of 1980 or JP-A No. 138461 of 1981, which discloses a structure in which apertures for absorbing pressure waves of thermal energy correspond to the discharge part. be.

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

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 camping means, cleaning means, pressurizing or suction means, electrothermal transducer or separate heating element, or these 8. It is also effective for stable recording to perform a preliminary ejection mode in which the main ejection is performed for both the thermal means and recording by combining the inkjet ink with one layer.

Furthermore, the recording mode of the recording device is not limited to a recording mode for mainstream colors such as black, but may also be configured by integrally configuring the recording head or by combining a plurality of recording heads; The present invention is also extremely effective for devices equipped with at least one full color by color mixture.

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. Since the temperature is generally controlled within a range of 70° C. or less so that the viscosity of the ink is within the stable ejection range, it is sufficient that the ink is in a liquid state when the recording signal is applied.

In addition, it is possible to proactively prevent temperature rise caused by thermal energy by using it as energy to transform the ink from a solid state to a liquid state, or to prevent ink from evaporating by preventing ink from solidifying when left unused. In any case, the ink may be liquefied by applying thermal energy in accordance with the recording signal and ejected as liquid ink, or the ink may already begin to solidify by the time it reaches the recording material. Note that the use of ink that is liquefied only by thermal energy is also applicable to the present invention.

In such a case, as in JP-A-54-56841, the ink is held as a liquid or solid in the recesses or through-holes of the porous sheet and is placed facing the electrothermal transducer. It is also possible to take the following form.

In the present invention, the most effective method for the above-mentioned ink is the one that implements the above-mentioned film boiling method.

[Effects of the Invention] As is clear from the above description, according to the invention of claim 1, the recording head is configured to perform recording using a plurality of recording heads that eject recording liquids of different colors or different concentrations, and the recording head In an inkjet recording apparatus having a wiper member that can come into contact with the ejection port surface, an ink reservoir is provided at a position adjacent to the wiper member, and after the wiper member is brought into contact with the ejection port surface during a predetermined operation, Since the structure is such that ink is ejected from each print head to the above-mentioned reservoir, the simple and inexpensive structure prevents color mixing of ink at the ejection part even when printing is performed using a plurality of print heads. Therefore, an inkjet recording apparatus is provided that can reliably clean the ejection port surface of each recording head.

According to the second aspect of the present invention, in addition to the above configuration, the wiper member and the ejection port surface are brought into contact with each other in the order of the brightness of the recording liquid during a predetermined operation. In addition to the above effects, an inkjet recording apparatus is provided that can reliably prevent color mixing of inks and deterioration of image quality due to the color mixing.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view showing an embodiment of an inkjet recording apparatus according to the present invention, FIG. 2 is a flowchart showing a recovery operation sequence of the recording apparatus of FIG. 1, and FIG. 3 is a schematic perspective view of the recording apparatus of FIG. 1. FIG. 4 is a schematic perspective view showing the configuration of a conventional inkjet recording apparatus. Below, symbols representing main components in the drawings are listed. 1-1--Recording head, 2-1--Ink tank, 3-Carriage, 4---Recovery device, 5--Wiper member, 6--Gearing means, 11-1 1---Recording material, 12---Ink reservoir.

Claims (4)

[Claims] (1) In an inkjet recording apparatus that is configured to perform recording using a plurality of recording heads that discharge recording liquids of different colors or different concentrations, and that includes a wiper member that can come into contact with the discharge port surface of the recording head, the wiper member An ink jet recording characterized in that an ink reservoir is provided at a position adjacent to the member, and during a predetermined operation, after the wiper member is brought into contact with the ejection port surface, ink is ejected from each recording head to the ink reservoir. Device. (2) The inkjet recording apparatus according to claim 1, wherein the wiper member and the ejection port surface come into contact with each other in the order of the recording head having the brightness of the recording liquid during a predetermined operation. (3) The recording head is an inkjet recording head that discharges ink using thermal energy, and includes an electrothermal converter for generating thermal energy. inkjet recording device. (4) The inkjet recording apparatus according to claim 3, wherein the ink is ejected from the ejection port by the growth of bubbles due to film boiling caused by the thermal energy applied by the electrothermal converter.