JP7009837B2 - Recording head and inkjet recording device equipped with it - Google Patents

Description

The present invention relates to a recording head having an ink ejection port for ejecting ink to a recording medium such as paper, and an inkjet recording apparatus provided with the recording head.

As a recording device such as a facsimile, a copying machine, and a printer, an inkjet recording device that ejects ink to form an image is widely used because it can form a high-definition image.

In such an inkjet recording device, minute ink droplets (hereinafter referred to as mist) ejected together with ink droplets for image recording and rebounding mist generated when the ink droplets adhere to a recording medium are recorded heads. Adheres to the ink ejection surface and solidifies. When the mist on the ink ejection surface gradually increases and overlaps with the ink ejection port, the straightness of the ink deteriorates (flying bend) and non-ejection occurs, and the printing performance of the recording head deteriorates.

Therefore, in order to clean the ink ejection surface of the recording head, the cleaning liquid supply port is located outside the ink ejection region (upstream in the wiper wiping direction) where a plurality of ink ejection ports are opened. There is known an inkjet recording device provided with a plurality of ink jet recording devices. In this inkjet recording device, after the cleaning liquid is supplied from the cleaning liquid supply port, the wiper is moved from the outside of the cleaning liquid supply port along the ink ejection surface, so that the ink ejection surface is held by the wiper. Can be wiped. In this way, the recovery process of the recording head can be performed.

An inkjet recording device provided with a plurality of cleaning liquid supply ports on the ink ejection surface of the recording head is disclosed in, for example, Patent Document 1.

Japanese Unexamined Patent Publication No. 2007-83496

By the way, when the recording head is new, the cleaning liquid chamber connected to the plurality of cleaning liquid supply ports is filled with air. Then, when the cleaning liquid is supplied from the cleaning liquid tank when the recovery process of the recording head is performed for the first time, the cleaning liquid passes through the cleaning liquid chamber, reaches the cleaning liquid supply port, and is supplied to the cleaning liquid supply surface. To. After the recovery process of the recording head is performed once, the cleaning liquid chamber is filled with the cleaning liquid, and the cleaning liquid supply port is filled with the meniscus of the cleaning liquid.

However, the conventional inkjet recording apparatus has a problem that air may remain in the cleaning liquid chamber when the cleaning liquid is first supplied from the cleaning liquid tank. If air remains in the cleaning liquid chamber, the amount of cleaning liquid supplied may be insufficient due to the air being discharged from the cleaning liquid supply port when the cleaning liquid is supplied from the cleaning liquid supply port, or the cleaning liquid supply port may be cleaned. The meniscus of the liquid may not be stretched normally.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to create an ink ejection surface while suppressing air from remaining in the cleaning liquid chamber at the time of initial filling of the cleaning liquid. It is an object of the present invention to provide a recording head capable of cleaning and an inkjet recording apparatus including the recording head.

In order to achieve the above object, the recording head according to the first aspect of the present invention includes an ink ejection surface on a recording medium through which a plurality of ink ejection ports are opened. The recording head is arranged upstream of the ink ejection port in the wiping direction in which the wiper wipes the ink ejection surface, and is provided at a plurality of cleaning liquid supply ports for supplying cleaning liquid and a plurality of cleaning liquid supply ports. It is equipped with a cleaning liquid chamber that is connected and filled with cleaning liquid. The height from the bottom surface to the top surface of the cleaning liquid chamber is smaller than the depth of the cleaning liquid supply port.

According to the recording head of the first aspect of the present invention, a plurality of cleaning liquid supply ports for supplying the cleaning liquid are provided on the upstream side in the wiping direction with respect to the ink ejection port. As a result, after the cleaning liquid is supplied from the cleaning liquid supply port, the wiper is moved along the ink ejection surface from the upstream side in the wiping direction from the cleaning liquid supply port, so that the ink ejection surface is held by the wiper. Can be wiped. Therefore, the ink ejection surface can be cleaned.

Further, the height from the bottom surface to the top surface of the cleaning liquid chamber is smaller than the depth of the cleaning liquid supply port. As a result, by supplying the cleaning liquid from the cleaning liquid tank when the recovery process of the recording head is performed for the first time, the air in the cleaning liquid chamber can be quickly discharged from the cleaning liquid supply port, so that the air in the cleaning liquid chamber can be quickly discharged. Can be suppressed from remaining. For this reason, when the cleaning liquid is supplied from the cleaning liquid supply port (during recovery processing), air is discharged from the cleaning liquid supply port and the supply amount of the cleaning liquid is insufficient, or the meniscus of the cleaning liquid is normal in the cleaning liquid supply port. It is possible to prevent the person from becoming unable to stretch.

The figure which shows the structure of the inkjet recording apparatus provided with the recording head of one Embodiment of this invention. A view of the first transport unit and the recording unit of the inkjet recording apparatus shown in FIG. 1 as viewed from above. Diagram of the recording head that constitutes the line head of the recording unit View of the recording head from the ink ejection surface side A view of the cleaning liquid supply port of the cleaning liquid supply member of the recording head as viewed from below. The figure which shows the structure around a recording head, a sub tank and a main tank The figure which shows the structure of the cleaning liquid supply member of a recording head. The figure which shows the structure around the cleaning liquid supply port of the cleaning liquid supply member of a recording head. The figure which shows the state which the maintenance unit is arranged under the recording part. It is a figure which shows the structure around the cleaning liquid supply port of the cleaning liquid supply member of a recording head, and is the figure which shows the state which the liquid level of a cleaning liquid is formed in the cleaning liquid supply port. The figure which shows the state which the wiper is arranged under the recording head. It is a figure which shows the structure around the cleaning liquid supply port of the cleaning liquid supply member of a recording head, and is the figure which shows the state which the cleaning liquid is supplied from the cleaning liquid supply port. The figure which shows the state which raised the wiper from the state of FIG. 11 and brought it into pressure contact with a cleaning liquid supply member. The figure which shows the state which moved in the direction of arrow A with the wiper being pressure-contacted with the cleaning liquid supply member from the state of FIG. It is a figure which shows the structure around the cleaning liquid supply port of the cleaning liquid supply member of a recording head, and is the figure which shows the state after wiping the cleaning liquid supply surface with a wiper. The figure which shows the state which moved the wiper further in the direction of arrow A from the state of FIG. FIG. 6 is a diagram showing a state in which the wiper is further moved in the direction of arrow A from the state of FIG. 16 and then the wiper is lowered and separated from the ink ejection surface. A view of the ink ejection port and the cleaning liquid supply port of the head portion of the recording head of the modified example of the present invention as viewed from below.

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

As shown in FIG. 1, a paper feed tray 2 for accommodating paper S (recording medium) is provided on the left side of the inkjet recording apparatus 100 according to the embodiment of the present invention, and one end of the paper feed tray 2 is provided. The paper S stored in the paper S is transferred and fed one by one to the first transport unit 5, which will be described later, in order from the top paper S, and the paper S is pressed against the paper feed roller 3 and driven to rotate. A driven roller 4 is provided.

The first transport unit 5 and the recording unit 9 are arranged on the downstream side (right side in FIG. 1) of the paper feed roller 3 and the driven roller 4 with respect to the paper transport direction (arrow X direction). The first transfer unit 5 has a configuration including a first drive roller 6, a first driven roller 7, and a first transfer belt 8 spanned by the first drive roller 6 and the first driven roller 7. The first drive roller 6 is rotationally driven in the clockwise direction by a control signal from the control unit 110 of the recording device 100, so that the paper S held by the first conveyor belt 8 is conveyed in the arrow X direction.

The recording unit 9 includes a head housing 10 and line heads 11C, 11M, 11Y, and 11K held in the head housing 10. These line heads 11C to 11K are supported at a height such that a predetermined distance (for example, 1 mm) is formed with respect to the transport surface of the first transport belt 8, and as shown in FIG. 2, the line heads 11C to 11K are supported in the paper transport direction. It is composed of one or more (here, one) recording heads extending along the orthogonal paper width direction (vertical direction in FIG. 2).

As shown in FIGS. 3 and 4, the ink ejection surface F1 of the head portion (ink ejection head portion) 18 of the recording head 17 has an ink ejection region R1 in which a large number of ink ejection ports 18a (see FIG. 2) are arranged. It is provided.

In the recording heads 17 constituting the line heads 11C to 11K, four colors (cyan, magenta, yellow, and black) of ink stored in the ink tanks (not shown) are used for each of the line heads 11C to 11K. Is supplied to.

Each recording head 17 heads toward the paper S which is sucked and held on the transport surface of the first transport belt 8 and transported according to the image data received from the external computer by the control signal from the control unit 110 (see FIG. 1). Ink is ejected from the ink ejection port 18a. As a result, a color image in which four color inks of cyan, magenta, yellow, and black are superimposed is formed on the paper S on the first transport belt 8.

Further, the recording head 17 is provided with a cleaning liquid supply member (cleaning liquid supply head portion) 60 for supplying the cleaning liquid. The cleaning liquid supply member 60 is arranged adjacent to the head portion 18 on the upstream side (right side in FIG. 3) of the wiper 35 described later in the wiping direction. The cleaning liquid supply member 60 has a cleaning liquid supply surface F2 including a cleaning liquid supply region R2 in which a large number of cleaning liquid supply ports 60a (see FIG. 5) for supplying the cleaning liquid are arranged. At least the ink ejection surface F1 of the head portion 18 is formed of, for example, SUS (stainless steel), and the cleaning liquid supply member 60 is formed of, for example, resin.

The cleaning liquid supply surface F2 is formed flush with the ink ejection surface F1. Further, an inclined surface 62 is formed on a portion of the cleaning liquid supply member 60 on the upstream side (right side in FIG. 3) in the wiping direction with respect to the cleaning liquid supply surface F2.

The cleaning liquid is preferably a solution composed of components similar to ink, and is a liquid composition mainly composed of water and a solvent component, to which a surfactant, an antiseptic and an antifungal agent, etc. are added as necessary.

As shown in FIG. 6, the cleaning liquid supply port 60a (see FIG. 5) of the cleaning liquid supply member 60 is connected to the downstream end of the cleaning liquid supply path 70 including a tube through which the cleaning liquid 23 passes. The upstream end of the cleaning liquid supply path 70 is connected to a sub tank 71 that houses the cleaning liquid 23 supplied to the cleaning liquid supply member 60. The upstream end of the cleaning liquid supply path 70 is immersed in the cleaning liquid 23. The cleaning liquid supply path 70 is provided with a supply pump 72 that pumps the cleaning liquid 23 from the sub tank 71 and sends it to the cleaning liquid supply member 60. In the figure, the cleaning liquid 23 is hatched for easy understanding.

Further, the sub tank 71 is connected to the downstream end of the cleaning liquid replenishment path 80, which is a tube through which the cleaning liquid 23 passes. The upstream end of the cleaning liquid replenishment path 80 is connected to the main tank 81 that houses the cleaning liquid 23 to be replenished to the sub tank 71. The upstream end of the cleaning liquid replenishment path 80 is immersed in the cleaning liquid 23. The cleaning liquid replenishment path 80 is provided with a replenishment pump 82 that pumps the cleaning liquid 23 from the main tank 81 and sends it to the sub tank 71. As the supply pump 72 and the supply pump 82, for example, a tube pump, a syringe pump, a diaphragm pump, or the like can be used. However, the supply pump 72 is configured to be able to switch between a state in which the inlet and the outlet of the supply pump 72 are cut off and a state in which the supply pump 72 is in communication with each other when the supply is stopped. The detailed structure around the cleaning liquid supply member 60, the sub tank 71, and the main tank 81 will be described later.

In the inkjet recording apparatus 100, in order to clean the ink ejection surface F1 of the recording head 17, ink is ink from all the ink ejection ports 18a of the recording head 17 at the start of printing after a long-term stop and between printing operations. Is forcibly discharged, and in parallel, the cleaning liquid 23 is supplied to the cleaning liquid supply region R2 from the cleaning liquid supply port 60a (see FIG. 5) of all the recording heads 17, and the ink ejection surface F1 is discharged by the wiper 35 described later. Wipe off and prepare for the next printing operation.

Returning to FIG. 1, the second transport unit 12 is arranged on the downstream side (right side of FIG. 1) of the first transport unit 5 with respect to the paper transport direction. The second transfer unit 12 has a configuration including a second drive roller 13, a second driven roller 14, and a second transfer belt 15 spanned by the second drive roller 13 and the second driven roller 14. By rotationally driving the two-drive roller 13 in the clockwise direction, the paper S held by the second transport belt 15 is conveyed in the direction of the arrow X.

The paper S on which the ink image is recorded by the recording unit 9 is sent to the second transport unit 12, and the ink discharged on the surface of the paper S is dried while passing through the second transport unit 12. Further, a maintenance unit 19 and a cap unit 90 are arranged below the second transport unit 12. When the wiping operation by the wiper 35 described above is executed, the first transport unit 5 is lowered, the maintenance unit 19 is moved below the recording unit 9, and the ink ejection port 18a of the recording head 17 is forcibly discharged. The cleaning liquid 23 supplied from the ink and cleaning liquid supply port 60a is wiped off, and the wiped ink and cleaning liquid 23 are collected. When capping the ink ejection surface F1 (see FIG. 3) of the recording head 17, the first transport unit 5 is lowered, and the cap unit 90 is horizontally moved below the recording unit 9 and further moved upward. It is mounted on the lower surface of the recording head 17.

Further, on the downstream side of the second transport unit 12 with respect to the paper transport direction, a discharge roller pair 16 for discharging the paper S on which the image is recorded to the outside of the main body of the apparatus is provided, and the downstream side of the discharge roller pair 16. Is provided with a discharge tray (not shown) on which the paper S discharged to the outside of the main body of the apparatus is loaded.

The maintenance unit 19 supports a plurality of wipers 35 (see FIG. 11) that can move along the ink ejection surface F1, a substantially rectangular carriage (not shown) to which the plurality of wipers 35 are fixed, and a carriage. It is composed of a support frame (not shown). The carriage (not shown) is slidably supported in the direction of arrow AA'with respect to the support frame (not shown).

The wiper 35 is an elastic member (for example, a rubber member made of EPDM) for wiping the cleaning liquid 23 supplied to the cleaning liquid supply surface F2 from the cleaning liquid supply port 60a (see FIG. 5) of each recording head 17. .. The wiper 35 is pressed against a portion (here, an inclined surface 62) on the upstream side in the wiping direction with respect to the cleaning liquid supply region R2 (see FIG. 4) of the cleaning liquid supply member 60, and is moved by the carriage (not shown). Wipe the cleaning liquid supply surface F2 and the ink ejection surface F1 in a predetermined direction (arrow A direction).

Next, the structures around the cleaning liquid supply member 60, the sub tank 71, and the main tank 81 will be described in detail.

As shown in FIG. 6, a first detection sensor 73 for detecting the cleaning liquid 23 is provided at a predetermined position of the sub tank 71. The first detection sensor 73 has an electrode pair (not shown) arranged in the sub tank 71 when a voltage is applied. The first detection sensor 73 can detect the presence / absence of the cleaning liquid 23 based on the presence / absence of energization between the electrodes. When the first detection sensor 73 detects that there is no liquid (without energization), the replenishment pump 82 replenishes the cleaning liquid 23 from the main tank 81 to the sub tank 71 until the presence of liquid (with energization) is detected. As a result, the liquid level (upper surface) of the cleaning liquid 23 in the sub tank 71 is maintained at a substantially constant height.

A second detection sensor 83 for detecting the cleaning liquid 23 is provided at the lower part of the main tank 81. The second detection sensor 83 has an electrode pair (not shown) arranged in the main tank 81 as the voltage is applied. The second detection sensor 83 can detect the presence / absence of the cleaning liquid 23 based on the presence / absence of energization between the electrodes. When the second detection sensor 83 detects that there is no liquid, the display panel (not shown) of the inkjet recording device 100 is notified that the main tank 81 is empty. As a result, the main tank 81 is replaced with a new one, or the main tank 81 is replenished with the cleaning liquid 23 by the user or the operator.

The sub tank 71 is arranged above the main tank 81 and below the cleaning liquid supply surface F2 of the recording head 17. Further, the sub tank 71 is provided with an atmospheric opening 71a for making the pressure in the internal space equal to the atmospheric pressure. Therefore, when the supply pump 72 is turned off and the inlet and outlet of the supply pump 72 are in a communicating state, a negative pressure is applied to the cleaning liquid 23 of the cleaning liquid supply port 60a.

As shown in FIG. 5, the plurality of cleaning liquid supply ports 60a are arranged at predetermined intervals in the wiping direction (arrow A direction) and the head width direction (arrow BB'direction, direction orthogonal to the wiping direction). ing.

Specifically, the supply port rows E1 are configured by arranging a plurality of cleaning liquid supply ports 60a along the head width direction. The supply port rows E1 are provided in a plurality of rows (two rows in FIG. 5) along the wiping direction. Further, the supply port rows E1 are arranged so as to be offset by a half pitch in the head width direction with respect to the adjacent supply port rows E1. Therefore, the cleaning liquid supply ports 60a are arranged in a staggered pattern. The supply port row E1 may be provided in one row or three or more rows. Further, the supply port row E1 may not be arranged so as to be displaced in the head width direction with respect to the adjacent supply port row E1.

As shown in FIG. 7, the cleaning liquid supply member 60 is composed of an upper member 64 and a lower member 65. The upper member 64 and the lower member 65 are made of resin. The upper member 64 and the lower member 65 form a cleaning liquid chamber Q filled with the cleaning liquid 23 supplied from the sub tank 71 (see FIG. 6). The cleaning liquid chamber Q is formed so as to spread substantially horizontally along the cleaning liquid supply surface F2. A plurality of cleaning liquid supply ports 60a are connected to one end of the cleaning liquid chamber Q (the end in the direction of arrow A).

The upper member 64 constitutes the upper surface and the side surface of the cleaning liquid chamber Q. The upper member 64 is provided with a connecting portion 64a to which the downstream end of the cleaning liquid supply path 70 (see FIG. 6) is connected. The connection portion 64a is connected to a portion on the other side (direction of arrow A') of the cleaning liquid chamber Q.

The lower member 65 constitutes the bottom surface and the side surface of the cleaning liquid chamber Q. The lower member 65 includes a bottom surface portion 65a that constitutes the bottom surface of the cleaning liquid chamber Q and has a cleaning liquid supply surface F2 formed therein, and an inclined portion 65b that is continuously provided on the bottom surface portion 65a and has an inclined surface 62 formed therein. , Includes.

A plurality of cleaning liquid supply ports 60a are provided on the bottom surface portion 65a. The cleaning liquid supply port 60a is formed in a circular shape in a plan view. The inner surface of the cleaning liquid supply port 60a is provided perpendicular to the cleaning liquid supply surface F2. That is, the cleaning liquid supply port 60a is formed to have a constant inner diameter from the lower end to the upper end.

As shown in FIG. 8, the height Hq from the bottom surface to the top surface of the cleaning liquid chamber Q is formed to be smaller than the depth H60a (thickness of the bottom surface portion 65a) of the cleaning liquid supply port 60a. Further, the depth H60a of the cleaning liquid supply port 60a is formed to be larger than the inner diameter D60a of the cleaning liquid supply port 60a. Specifically, the height Hq from the bottom surface to the top surface of the cleaning liquid chamber Q is formed to be about 1.0 mm, and the depth H60a of the cleaning liquid supply port 60a is formed to be about 1.5 mm. There is. Further, the inner diameter D60a of the cleaning liquid supply port 60a is formed to be about 1.0 mm. The height Hq from the bottom surface to the top surface of the cleaning liquid chamber Q is preferably formed to be about 1.5 mm or less, and more preferably about 1.0 mm or less.

In the inkjet recording apparatus 100, when the recording head 17 is new, the cleaning liquid chamber Q connected to the plurality of cleaning liquid supply ports 60a is filled with air. Then, when the recovery process of the recording head 17 is performed for the first time, the cleaning liquid 23 is supplied from the sub tank 71, so that the cleaning liquid 23 passes through the cleaning liquid chamber Q and reaches the cleaning liquid supply port 60a to supply the cleaning liquid. It is supplied to the surface F2. At this time, the air in the cleaning liquid chamber Q is pushed out from the cleaning liquid supply port 60a by the cleaning liquid 23.

Next, the recovery operation of the recording head 17 using the maintenance unit 19 in the inkjet recording apparatus 100 of the present embodiment will be described. The recovery operation of the recording head 17 described below is executed by controlling the operations of the recording head 17, the maintenance unit 19, the supply pump 72, etc. based on the control signal from the control unit 110 (see FIG. 1). To.

When performing the recovery operation of the recording head 17, first, as shown in FIG. 9, the control unit 110 (see FIG. 1) lowers the first transport unit 5 located below the recording unit 9. Then, the control unit 110 horizontally moves the maintenance unit 19 arranged below the second transfer unit 12 and arranges it between the recording unit 9 and the first transfer unit 5. In this state, the wiper 35 (see FIG. 11) of the maintenance unit 19 is arranged below the ink ejection surface F1 and the cleaning liquid supply surface F2 (see FIG. 3) of the recording head 17. At this time, the supply pump 72 is in the off state, and as shown in FIG. 10, the liquid level of the cleaning liquid 23 is formed in the cleaning liquid supply port 60a. That is, the meniscus of the cleaning liquid 23 is formed so as to be curved inward of the recording head 17 starting from the lower end edge of the cleaning liquid supply port 60a.

(Cleaning liquid supply operation)
Prior to the wiping operation (wiping operation described later), the supply pump 72 (see FIG. 6) is driven (on) by the control unit 110 (see FIG. 1), and the cleaning liquid 23 is sent to the recording head 17 as shown in FIG. After being supplied and a predetermined time has elapsed, the supply pump 72 is stopped (off), and the inlet and outlet of the supply pump 72 are cut off. At this time, the cleaning liquid 23 is in the state shown in FIG. That is, the cleaning liquid 23 is in a state of protruding from the cleaning liquid supply port 60a in a convex shape due to the surface tension of the cleaning liquid 23.

(Ink extrusion operation)
Further, prior to the wiping operation (wiping operation described later), the ink 22 is supplied to the recording head 17 by the control unit 110 (see FIG. 1) as shown in FIG. The supplied ink 22 is forcibly extruded (purged) from the ink ejection port 18a. By this purging operation, the thickened ink, foreign matter and air bubbles in the ink ejection port 18a are discharged from the ink ejection port 18a. At this time, the purge ink 22 is extruded to the ink ejection surface F1 along the shape of the ink ejection region R1 in which the ink ejection port 18a is present. In the figure, the ink (purge ink) 22 is hatched for easy understanding.

(Wipe operation)
As shown in FIG. 13, the control unit 110 raises the wiper 35 to bring the wiper 35 into contact with the inclined surface 62 of the cleaning liquid supply member 60 of the recording head 17 at a predetermined pressure. At this time, the wiper 35 is raised so that the upper surface of the wiper 35 is higher than the ink ejection surface F1 and the cleaning liquid supply surface F2 by about 1 mm. As a result, the amount of bite (overlap amount) of the wiper 35 with respect to the ink ejection surface F1 and the cleaning liquid supply surface F2 becomes about 1 mm. At the time when the wiper 35 is raised, the wiper 35 may not be in pressure contact with the inclined surface 62. That is, the wiper 35 may be raised at a position on the right side of FIG.

From the state where the tip of the wiper 35 is in pressure contact with the inclined surface 62 of the cleaning liquid supply member 60, the control unit 110 directs the wiper 35 in the direction of the ink ejection region R1 along the cleaning liquid supply surface F2 as shown in FIG. 14 (arrow A). Move in the direction). As a result, the wiper 35 moves in the direction of the ink ejection region R1 while holding the cleaning liquid 23 by scooping the cleaning liquid 23 in a state of protruding convexly from the cleaning liquid supply port 60a. At this time, the cleaning liquid 23 of the cleaning liquid supply member 60 is in the state shown in FIG.

When the tip of the wiper 35 passes through the cleaning liquid supply region R2, the communication state is switched between the inlet and outlet of the supply pump 72. As a result, a negative pressure is applied to the cleaning liquid 23 of the cleaning liquid supply port 60a, the cleaning liquid 23 is sucked into the cleaning liquid supply port 60a, and the state of FIG. 10 is restored.

Then, as shown in FIG. 16, the wiper 35 moves the ink ejection surface F1 to the left (direction of arrow A) while maintaining the state of holding the cleaning liquid 23. At this time, the cleaning liquid 23 and the ink (purge ink) 22 dissolve the ink droplets (waste ink) that have adhered to and solidified on the ink ejection surface F1 and are wiped off by the wiper 35. Then, the wiper 35 further moves to the left (direction of arrow A), and when it reaches a position opposite to the cleaning liquid supply area R2 with respect to the ink ejection area R1, the movement to the left is stopped. The cleaning liquid 23 and waste ink wiped off by the wiper 35 are collected in a cleaning liquid recovery tray (not shown) provided in the maintenance unit 19.

(Separation operation)
After executing the wiping operation, as shown in FIG. 17, the control unit 110 lowers the wiper 35 to separate it from the ink ejection surface F1.

Finally, the control unit 110 horizontally moves the maintenance unit 19 arranged between the recording unit 9 and the first transfer unit 5 and arranges it below the second transfer unit 12, and determines the first transfer unit 5. Raise to the position of. In this way, the recovery operation of the recording head 17 is terminated.

In the present embodiment, as described above, a plurality of cleaning liquid supply ports 60a for supplying the cleaning liquid 23 are provided on the upstream side in the wiping direction with respect to the ink ejection port 18a. As a result, after the cleaning liquid 23 is supplied from the cleaning liquid supply port 60a, the wiper 35 is moved along the ink ejection surface F1 from the upstream side in the wiping direction with respect to the cleaning liquid supply port 60a, whereby the cleaning liquid 23 is moved by the wiper 35. The ink ejection surface F1 can be wiped while holding the above. Therefore, the ink ejection surface F1 can be cleaned.

Further, the height Hq from the bottom surface to the top surface of the cleaning liquid chamber Q is smaller than the depth H60a of the cleaning liquid supply port 60a. As a result, by supplying the cleaning liquid 23 from the sub tank 71 when the recovery process of the recording head 17 is performed for the first time, the air in the cleaning liquid chamber Q can be quickly discharged from the cleaning liquid supply port 60a, so that the cleaning liquid can be quickly discharged. It is possible to suppress the residual air in the chamber Q. Therefore, when the cleaning liquid 23 is supplied from the cleaning liquid supply port 60a (during the recovery process), air is discharged from the cleaning liquid supply port 60a and the supply amount of the cleaning liquid 23 becomes insufficient, or the cleaning liquid supply port 60a is cleaned. It is possible to prevent the meniscus of the liquid 23 from being stretched normally.

Further, as described above, the depth H60a of the cleaning liquid supply port 60a is larger than the inner diameter D60a of the cleaning liquid supply port 60a. As a result, even when vibration or impact is applied to the recording head 17, it is possible to prevent the meniscus of the cleaning liquid 23 from being destroyed. Therefore, it is possible to prevent the cleaning liquid 23 from dripping from the cleaning liquid supply port 60a and contaminating the paper S, or preventing the cleaning liquid 23 from flowing back into the recording head 17. In order to prevent the meniscus of the cleaning liquid 23 from being destroyed, it is preferable that the inner diameter D60a of the cleaning liquid supply port 60a is small, and the depth H60a of the cleaning liquid supply port 60a is large.

Further, as described above, the height Hq from the bottom surface to the top surface of the cleaning liquid chamber Q is 1.5 mm or less, more preferably 1.0 mm or less. As a result, by supplying the cleaning liquid 23 from the sub tank 71 when the recovery process of the recording head 17 is performed for the first time, the air in the cleaning liquid chamber Q can be discharged more quickly from the cleaning liquid supply port 60a, so that cleaning can be performed. It is possible to further suppress the residual air in the liquid chamber Q.

Further, as described above, the plurality of cleaning liquid supply ports 60a are provided in the cleaning liquid supply region R2 arranged on the upstream side in the wiping direction with respect to the ink ejection region R1 in which the plurality of ink ejection ports 18a open. ing. As a result, the ink passage path and the cleaning liquid passage path in the recording head 17 can be formed separately (separately), so that it is possible to suppress the structure of the recording head 17 from becoming complicated.

Further, as described above, the recording head 17 is composed of a head portion 18 in which a plurality of ink ejection ports 18a are formed, and a cleaning liquid supply member 60 in which a plurality of cleaning liquid supply ports 60a are formed. .. As a result, the cleaning liquid supply port 60a can be easily formed as compared with the case where the cleaning liquid supply port 60a is formed in the head portion 18.

It should be noted that the embodiments disclosed this time are exemplary in all respects and are not considered to be restrictive. The scope of the present invention is shown by the scope of claims rather than the description of the embodiment described above, and further includes all modifications within the meaning and scope equivalent to the scope of claims.

For example, in the above embodiment, the cleaning liquid supply member 60 in which the cleaning liquid supply port 60a is formed is provided separately from the head portion 18, but the present invention is not limited to this. The cleaning liquid supply port 60a may be formed in the head portion 18 without providing the cleaning liquid supply member 60. At this time, for example, as in the recording head 17 of the modified example of the present invention shown in FIG. 18, the cleaning liquid supply port 60a is adjacent to the ink ejection port 18a (for example, the ink ejection port 18a and the supply port row E1 are arranged. It may be arranged alternately in the direction of the arrow AA'.

Further, in the above embodiment, an example in which the cleaning liquid supply port 60a is formed in a circular shape in a plan view is shown, but the present invention is not limited to this. The cleaning liquid supply port 60a may be formed in a rectangular shape, a polygonal shape, or the like in a plan view. In the present specification, the circular shape is a concept including not only a perfect circular shape but also an elliptical shape and an oval shape. Further, in the present specification and claims, the inner diameter means the maximum length between opposite side surfaces in an opening, for example, the diameter in a perfect circle shape, and the major diameter in an elliptical shape and an oval shape.

Further, in the above embodiment, the recovery operation of the recording head 17 is performed using the cleaning liquid 23 and the ink (purge ink) 22, but the recovery operation of the recording head 17 is performed using only the cleaning liquid 23. May be good. That is, it is not necessary to perform the ink extrusion operation.

Further, a configuration obtained by appropriately combining the configurations of the above-described embodiments and modifications is also included in the technical scope of the present invention.

17 Recording head 18 Head (ink ejection head)
18a Ink ejection port 22 Ink 23 Cleaning liquid 35 Wiper 60 Cleaning liquid supply member (cleaning liquid supply head)
60a Cleaning liquid supply port 100 Inkjet recording device D60a Inner diameter F1 Ink ejection surface F2 Cleaning liquid supply surface H60a Depth Hq Height Q Cleaning liquid chamber R1 Ink ejection area R2 Cleaning liquid supply area S Paper (recording medium)

Claims (8)

A recording head provided with an ink ejection surface in which a plurality of ink ejection ports for ejecting ink on a recording medium are opened.
A plurality of cleaning liquid supply ports arranged on the upstream side of the wiping direction, which is the direction in which the wiper wipes the ink ejection surface, with respect to the ink ejection port, and supply the cleaning liquid.
A cleaning liquid chamber in which the bottom surface is connected to the upper ends of the plurality of cleaning liquid supply ports and the cleaning liquid is filled,
Equipped with
A recording head characterized in that the height from the bottom surface of the cleaning liquid chamber to the top surface directly above the cleaning liquid supply port is smaller than the depth of the cleaning liquid supply port. The recording head according to claim 1, wherein the top surface directly above the cleaning liquid chamber is flat. The recording head according to claim 1 or 2, wherein the cleaning liquid chamber extends in a substantially horizontal direction, and the cleaning liquid flows in the cleaning liquid chamber in a substantially horizontal direction. The recording head according to any one of claims 1 to 3 , wherein the depth of the cleaning liquid supply port is larger than the inner diameter of the cleaning liquid supply port. The recording head according to any one of claims 1 to 4, wherein the height from the bottom surface to the top surface of the cleaning liquid chamber is 1.5 mm or less. The ink ejection surface includes an ink ejection region in which the plurality of ink ejection ports are opened.
Any one of claims 1 to 5 , wherein the plurality of cleaning liquid supply ports are provided in a cleaning liquid supply region arranged on the upstream side in the wiping direction with respect to the ink ejection region. The recording head described in the section. The recording head is characterized by being composed of an ink ejection head portion having the ink ejection surface and a cleaning liquid supply head portion having a cleaning liquid supply surface provided with the cleaning liquid supply area. Item 6. The recording head according to Item 6. The recording head according to any one of claims 1 to 7 .
A wiper that wipes the ink ejection surface of the recording head,
An inkjet recording device characterized by being equipped with.

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