JP2009132014A - Recording head protecting mechanism, inkjet recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To carry out the maintenance of a recording head while securing a feeding capacity of sheets of an inkjet recorder. <P>SOLUTION: A recording head protecting mechanism has: caps 41a to 44d covering the ink discharging ports of the recording heads 31a to 31d for carrying out the recording with ink on the sheets; a maintenance unit 40 for carrying out the maintenance of the recording heads; and a maintenance unit moving mechanism 50 for moving the maintenance unit 40 parallel to the conveying path of the sheets between the position facing the recording heads and the standby position in the outside from the arranged position of a conveying mechanism 20 having a conveying belt 24 for conveying the sheets and a driving roller 21 for driving the conveying belt 24, wherein the standby position of the maintenance unit 40 is above the sheet feeding deck 10 where the sheets conveyed by the conveying belt 24 are held. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a recording head protection mechanism used for protection or maintenance of a recording head in an inkjet recording apparatus and an inkjet recording apparatus using the same.

  FIG. 10 shows a conventional ink jet recording apparatus 100. The inkjet recording apparatus 100 includes a sheet separation roller pair 103 that guides the sheets 102 placed on the tray 101 to the inside of the apparatus one by one, a conveyance mechanism 110 that conveys the sheet guided by the sheet separation roller pair 103, and a conveyance An image forming unit 120 that forms an image by ejecting ink onto a sheet 102 conveyed on the mechanism 110, a discharge roller 104 for discharging the sheet 102 after image formation to the outside of the apparatus, and the like are provided.

  The transport mechanism 110 includes a drive roller 111, a driven roller 112, an annular transport belt 113 stretched around these rollers, a registration roller 114, and the like, and drives the transport belt 113 by the rotation of the drive roller 111. The driven roller 112 rotates according to the driving of the conveyor belt 113.

  The image forming unit 120 is a so-called line head type provided with line head type recording heads 121 a to 121 d, and is arranged in a row in a direction perpendicular to the conveyance direction of the paper 102.

  In such an ink jet recording apparatus 100, when the paper 102 moves along the transport belt 113, a color image is received by receiving the discharge of each color ink from the recording heads 121 a to 121 d of the image forming unit 120. It is formed. The sheet 102 on which the color image is formed is discharged from the discharge roller 104 to the outside of the apparatus and is accumulated on the tray 105.

  Incidentally, in an ink jet recording apparatus, maintenance of a recording head has been a problem from the past. In the case of the ink jet recording apparatus 100, when the recording heads 121a to 121d do not operate for a long time, the ink meniscus surfaces formed at the ink ejection ports of the recording heads 121a to 121d are dried, and appropriate ink ejection is performed. Will not be able to.

  Therefore, in the ink jet recording apparatus, maintenance of the recording head is performed. That is, when the recording operation is not performed on the paper, the recording heads 121a to 121d are forcibly operated to discharge the ink from the ink discharge ports, thereby removing the ink whose viscosity has been increased by drying.

  At this time, if the recording head is a serial ink jet type apparatus that reciprocates in a direction orthogonal to the paper transport direction, the maintenance operation should be performed after the recording head is moved to a position off the paper transport path. Can do.

  On the other hand, in the case of the line head type inkjet recording apparatus 100 in which the recording heads 121a to 121d are fixedly arranged on the conveying belt 113, a maintenance-specific unit is separately prepared and moved to the recording heads 121a to 121d to perform maintenance. To do.

That is, as shown in FIG. 10, in the inkjet recording apparatus 100, a maintenance unit having four caps 131a to 131d corresponding to the respective recording heads 121a to 121d and a main body portion 132 for collecting waste ink dropped from the caps 131a to 131d. 130 is provided. At the time of maintenance, as shown by an arrow A in the figure, the conveying mechanism 110 is separated immediately below the image forming unit 120 by a lifting mechanism (not shown) (shown by a dotted line in the figure), and then an image is formed as shown by an arrow B in the figure. The maintenance unit 130 is moved between the section 120 and the transport mechanism 110 (indicated by a dotted line in the figure), the recording heads 121a to 121d and the caps 131a to 131d are brought into contact with each other, and the ink in the maintenance unit 130 is discharged. Forced discharge is executed. During a normal printing operation, the reverse operation is performed, and the maintenance unit 130 is stored immediately below the tray 101 (see, for example, Patent Document 1).
JP 2006-102945 A

  However, the conventional ink jet recording apparatus 100 has the following problems.

  That is, in the above configuration, the maintenance unit 130 is housed in a space provided below the tray 101 during normal use. In this case, in a general-purpose image forming apparatus, the maintenance unit 130 is connected to an external paper feeding deck. The space used for connection is occupied by the maintenance unit 130, and the place where paper can be fed is limited to the tray 101. When the tray 101 has a small load, depending on the processing contents, it is necessary to frequently add sheets.

  In order to secure the space below the tray 101, it is conceivable to provide an independent maintenance unit for each head between the recording heads 121a to 121d. In this case, the interval between the recording heads 121a to 121d is increased. The length of the conveyor belt 113 becomes long. At this time, the gap between the head and the belt needs to be maintained at a size of about 1 mm. On the other hand, when the interval in the sheet conveyance direction from the recording heads 121a to 121d increases, it becomes difficult to ensure the dimensions.

  That is, in the conventional ink jet recording apparatus, it has been difficult to achieve a structure for performing maintenance while ensuring the sheet feeding capacity.

  The present invention has been made in view of such problems, and a recording head protection mechanism capable of performing maintenance of a recording head while securing a sheet feeding capacity of an ink jet recording apparatus, and the same are used. An object is to provide an ink jet recording apparatus.

In order to achieve the above object, a first aspect of the present invention includes a cap unit having a cap that covers an ink discharge port of a recording head that performs recording with ink on a recording medium;
In conjunction with the relative movement of the recording head and the recording medium conveying unit having a conveying belt for conveying the recording medium to the recording head side and a driving roller for driving the conveying belt, the cap unit moves the recording medium to the recording head. A cap unit moving unit that moves between a position facing the head and a standby position on the upstream side of the conveyor belt;
The standby position of the cap unit is a recording head protection mechanism above a storage space in which the recording medium to be transported by the transport belt is stored.

According to a second aspect of the present invention, when the recording head is raised, the recording head is ready for recording on the recording medium, and when the recording head is lowered, the cap unit is sandwiched between the recording medium transport unit and the recording head. A recording medium conveyance unit elevating unit that elevates and lowers the recording medium conveyance unit in a direction facing the recording head,
The recording head and the cap unit are brought into contact so that the cap covers the ink discharge port of the recording head when the cap is raised, and the recording head and the cap unit are separated from each other when the cap is lowered. The recording head protection mechanism according to the first aspect of the present invention includes a cap unit elevating unit that elevates and lowers the cap unit.

  According to a third aspect of the present invention, there is provided a recording head protection mechanism according to the first or second aspect of the present invention, comprising a unit cover provided at the standby position and covering the cap unit.

According to a fourth aspect of the present invention, there is provided a recording medium conveying unit having a conveying belt for conveying a recording medium and a driving roller for driving the conveying belt;
A recording head for recording with ink on the recording medium;
A storage unit for storing the recording medium;
An inkjet recording apparatus including the recording head protection mechanism according to any one of the first to third aspects of the present invention, which cooperates with the recording medium conveyance unit and the recording head.

  According to the present invention as described above, it is possible to provide a recording head protection mechanism that enables maintenance of a recording head while securing a sheet feeding capacity, and an ink jet recording apparatus using the same.

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

  1 is a front view of an essential part of an ink jet recording apparatus equipped with a recording head protection mechanism according to an embodiment of the present invention. FIG. 2A is a left side view of the essential part of FIG. (B) and FIG. 3 are top views of the same. However, in FIGS. 2A and 2B and FIG. 3, some of the configurations shown in FIG.

  As shown in FIG. 1, an ink jet recording apparatus 1 includes a paper feed deck 10 that stores paper that is a recording medium to be recorded, a pickup roller 10b that picks up paper 10a in the paper feed deck 10 one by one, a pickup A sheet separation roller pair 10c for separating the sheets 10a picked up by the rollers 10b one by one, a conveyance mechanism 20 for conveying the sheet guided from the sheet separation roller pair 10c, and a sheet conveyed on the conveyance mechanism 20 And an image forming unit 30 that forms an image by discharging ink.

  The conveyance mechanism 20 includes a registration roller 11, a driving roller 21, a driven roller 22, a tension roller 23, and an annular conveyance belt 24 that is stretched around these rollers. The conveyor belt 24 on which the sheet guided from 10c is placed is driven. The driven roller 22 rotates according to the driving of the conveyor belt 24, and the tension roller 23 applies a constant tension to the conveyor belt 24. Further, the drive mechanism 21, the driven roller 22, the tension roller 23, and the transport belt 24 are accommodated in the casing 25, so that the transport mechanism 20 is unitized.

  Also, as shown in FIGS. 2A and 2B, the image forming unit 30 is a line head type including line head type recording heads 31a to 31d, each along a direction orthogonal to the paper transport direction. Arranged in tandem.

  The ink jet recording apparatus 1 according to the present embodiment includes a maintenance unit 40, a maintenance unit moving mechanism 50, and a transport mechanism elevator 60 in addition to the above-described components.

  The maintenance unit 40 is provided in the main body portion 42 and the main body portion 42 having four caps 41a to 41d corresponding to the respective recording heads 31a to 31d and a waste ink tank (not shown) for collecting waste ink dropped from the caps 41a to 41d. A moving roller 43 is provided.

  As shown in FIGS. 1 and 3, the maintenance unit moving mechanism 50 includes pulleys 51 and 52 that can rotate, a wire 53 that spans the pulleys 51 and 52, a rail 54, and a maintenance unit elevator 55. . The wire 53 is disposed adjacent to both sides of the transport mechanism 20, and the rail 54 is further disposed adjacent to the outside of the wire 53.

  The wire 53 passes through and is coupled to the main body 42 of the maintenance unit 40. When the wire 53 is moved by driving the pulleys 51 and 52, the maintenance unit 40 moves on the rail 54 according to the behavior of the wire 53. Is moved by the moving roller 43. The maintenance unit elevator 55 is a circular cam having an eccentric rotation shaft 55a that is rotated by an external driving force (not shown). Arranged in the gap between the image forming unit 30 and the rail 54, the maintenance unit 40 is moved up and down as will be described later.

  Similarly to the maintenance unit elevator 55, the transport mechanism elevator 60 is a circular cam having an eccentric rotation shaft 60a that is rotated by an external driving force (not shown). The edge of the cam is in contact with the casing 25 and raises and lowers the transport mechanism 20 as will be described later.

  In the above configuration, the maintenance unit 40 corresponds to the cap unit of the present invention, the configuration of the maintenance unit moving mechanism 50 corresponds to the cap unit moving portion of the present invention, and the maintenance unit elevator 55 is the cap of the present invention. Corresponds to the unit lift. The transport mechanism lift 60 corresponds to the recording medium transport unit lifting / lowering portion of the present invention. The caps 41a to 41d correspond to the caps of the present invention.

  The maintenance unit 40, the maintenance unit moving mechanism 50, and the transport mechanism elevator 60 constitute a recording head protection mechanism of the present invention.

  The transport mechanism 20 corresponds to the recording medium transport unit of the present invention, the transport belt 24 corresponds to the transport belt of the present invention, and the drive roller 21 corresponds to the drive roller of the present invention. The recording heads 31a to 31d correspond to the recording head of the present invention, and the paper feed deck 10 corresponds to the storage unit of the present invention.

  The operation of the recording head protection mechanism according to the embodiment of the present invention having the above configuration will be described with reference to FIGS.

  First, the state shown in FIG. 1 is a normal operation state in which the recording heads 31a to 31d of the image forming unit 30 are opposed to the conveyance belt 24 of the conveyance mechanism 20 and are capable of recording on paper. At this time, the paper picked up from the paper feed deck 10 moves on the transport belt 24 and is ejected by the recording heads 31a to 31d. When an image is formed, the paper is further transported to an external discharge mechanism (not shown). Is done. The maintenance unit 40 is housed in a unit cover 70 provided directly above the paper feed deck 10. The unit cover 70 corresponds to the unit cover of the present invention, and the standby position of the maintenance unit 40 on the paper feed deck 10 corresponds to the standby position of the present invention. The unit cover 70 prevents dust and the like from adhering to the cap 41. That is, by keeping the cap 41 clean, dust or the like enters between the cap 41 and the recording head when the cap is brought into contact with the recording head 31, and the close contact between the recording head 31 and the cap 41 becomes incomplete. Occurrence of the phenomenon that the ink in the nozzles of the recording head dries can be prevented.

  Next, the operation when the maintenance operation is performed will be described with reference to FIGS.

  As shown in FIG. 4, the circular cam of the transport mechanism elevator 60 rotates about the rotation shaft 60 a so that the transport mechanism 20 moves from the image forming position to the retracted position. The transport mechanism elevator 60 in the normal operation state of FIG. 1 has the side where the distance between the rotation shaft 60a and the edge of the cam is large facing the transport mechanism 20, but after the rotation shown in FIG. Since the side where the distance between the moving shaft 60a and the edge of the cam is small faces the transport mechanism 20, the transport mechanism 20 descends toward the contrast position indicated by the arrow in the drawing with respect to the recording heads 31a to 31d at the fixed position. , Greatly separated from the conveyor belt 24.

  Next, as shown in FIG. 5, the pulleys 51 and 52 are rotationally driven to pull the wire 53 in the direction of arrow A in the figure. The maintenance unit 40 connected to the wire 53 is pulled from the unit cover 70 and moves on the rail 54, and as shown in FIG. 6, the recording heads 31a to 31d and the caps 41a to 41d of the image forming unit 30 face each other. Stop at.

  Next, as shown in FIG. 7, at the position where the image forming unit 30 and the maintenance unit 40 face each other, the circular cam of the maintenance unit elevator 55 is centered on the rotation shaft 55a, and the maintenance unit 40 is moved to the image forming unit 30. It turns so that it may move toward. In the normal operation state of FIG. 1 and the state of moving on the rail 54 shown in FIGS. 4 to 6, the maintenance unit elevator 55 is located on the side where the distance between the rotating shaft 55 a and the edge of the cam is small. The edge of the cam is located on the lower side with respect to the rail 54.

  On the other hand, after rotation, the side where the distance between the rotation shaft 55a and the edge of the cam of the maintenance unit elevator 55 is large faces the image forming unit 30 side. At this time, the edge portion is positioned on the upper side with respect to the rail 54, and the maintenance unit 40 placed on the rail 54 comes into contact with the edge portion of the cam as the maintenance unit elevator 55 rotates. Lifted from.

  The lifted maintenance unit 40 is coupled to the image forming unit 30 so that the caps 41a to 41d cover the recording heads 31a to 31d. Since the caps 41a to 41d cover the entire bottom surface of the recording heads 31a to 31d, the respective ink discharge ports are sealed, and maintenance such as forced ink discharge can be performed as in the conventional example. The cap unit of the present invention may be configured to simply seal the recording heads 31a to 31d by omitting the function of the main body portion 42. The recording head can be prevented from drying when the ink jet recording apparatus is not used.

  As described above, the recording head protection mechanism according to the present embodiment includes the maintenance unit moving mechanism 50 for moving to contact the image forming unit 30 during maintenance, and during normal operation, the tray 101 as in the prior art. Since the maintenance unit 130 is disposed below the maintenance deck 130, in this embodiment, the maintenance of the large capacity sheet feeding deck cannot be performed on the right side in FIG. By providing a place for storing the unit 40, a large sheet stacking amount can be secured as the sheet feeding deck 10 as in the case of a general-purpose image forming apparatus. In addition, since the maintenance unit 40 can be one in which the respective heads are integrated as in the conventional example, the dimensions of each part of the transport mechanism 20 can be suppressed as in the conventional example.

  Therefore, it is possible to obtain an effect that it is possible to configure an ink jet recording apparatus that can perform maintenance on the recording head while securing a paper feed space without increasing the size of the entire apparatus.

  In the above description, when the maintenance unit moving mechanism 50 moves the maintenance unit 40 directly below the image forming unit 30, the conveyance mechanism elevator 60 is used to fix the maintenance unit moving mechanism 50 fixedly arranged. Although the transport mechanism 20 is configured to move up and down, the transport mechanism 20 is not moved up and down, and the image forming unit 30 and the maintenance unit 40 are moved up and down to create a space in which the maintenance unit 40 can move directly below the image forming unit 30. It is good. In short, it is only necessary to create a space in which the cap unit can be moved directly under the recording head, and the present invention is not limited by a specific procedure for that purpose.

  Further, in order to connect the maintenance unit 40 and the image forming unit 30, the maintenance unit elevator 55 is used and the maintenance unit 40 is moved up and down with respect to the image forming unit 30 fixedly arranged. The image forming unit 30 may be moved up and down without being raised or lowered. In short, it is sufficient that the recording head and each cap of the cap unit can come into contact with each other, and the present invention is not limited by a specific procedure for that purpose.

  In the above configuration, the transport mechanism elevator 60 has been described as a circular cam having an eccentric rotation shaft 60a. However, the paper transport unit lifting unit of the present invention is not limited to this. Absent.

  FIG. 8 is a configuration diagram of a transport mechanism elevator 80 as another embodiment of the paper transport unit lifting unit. As shown in the figure, the transport mechanism elevator 80 includes a rotating shaft 81, five bearings 82a, 82b, 82c, 82d and 82e whose distance from the rotating shaft 81 gradually changes in alphabetical order. The two plate members 83a and 83b sandwich the bearings.

  The operation of the transport mechanism elevator 80 is basically the same as that of the transport mechanism elevator 60 using a circular cam. By rotating around the rotation shaft 81, the edge of the plate member moves to the housing of the transport mechanism 20. The body 25 is lifted, and as shown in FIGS. 9A and 9B, the housing portion 25 has bearings 82e, 82d, 82c, 82b, and 82a as the rotation shaft 81 rotates. Will contact step by step in this order. According to such a transport mechanism elevator 80, friction with the casing 25 can be reduced, and a load applied to a drive unit such as a rotation shaft 81 or a motor (not shown) that drives the rotation shaft 81 can be reduced. It becomes possible to smooth the change. The configuration of the transport mechanism elevator 80 may be implemented in the maintenance unit elevator 55.

  In addition, the configuration of the paper transport unit elevating unit or the cap unit elevating unit of the present invention may not be a configuration using a cam. A combination of a gear and a rack rail, a combination of a pulley and a wire, or a linear motor may be used. In short, as long as the paper transport unit or the cap unit can be raised and lowered, it is not limited by its specific configuration.

  Similarly, the cap unit moving portion of the present invention is configured to move the maintenance unit 40 as a cap unit by the pulleys 51 and 52, the wire 53, and the rail 54, but may be a combination of a gear and a rack rail. . In short, the specific configuration is not limited as long as the cap unit can be moved in parallel with the sheet conveyance path.

  Further, the ink jet recording apparatus shown in FIGS. 1 and 10 which includes the recording head protection mechanism of the present invention is also included in the present invention. As the image forming unit for forming an image on paper, the line head type ink jet recording head shown in FIG. 1 is suitable, but it may be applied to a serial type ink jet recording apparatus. In the above configuration, the recording heads 31a to 31d are provided. However, each recording head may be for forming a color image using different color inks, or the same color. A monochrome image using ink may be formed. Further, the number of recording heads may be one or five or more, and the present invention is not limited by the number.

  The recording medium of the present invention is not limited to the composition as long as it is an image forming target of the ink jet recording apparatus, and includes any material such as paper, cloth, disc, resin film and the like.

  INDUSTRIAL APPLICABILITY The present invention has an effect of enabling maintenance of a recording head while ensuring sheet feeding efficiency, and is useful in a recording head protection mechanism and an ink jet recording apparatus using the same.

FIG. 2 is a front view of a main part of an ink jet recording apparatus equipped with a recording head protection mechanism according to an embodiment of the present invention. (A) It is a principal part left side view of the inkjet recording device carrying the recording head protection mechanism of embodiment of this invention. (B) It is a principal part top view of the inkjet recording device carrying the recording head protection mechanism of embodiment of this invention. 1 is a plan view of a main part of an ink jet recording apparatus equipped with a recording head protection mechanism according to an embodiment of the present invention. FIG. 6 is a diagram for explaining the operation of the ink jet recording apparatus equipped with the recording head protection mechanism according to the embodiment of the present invention. FIG. 6 is a diagram for explaining the operation of the ink jet recording apparatus equipped with the recording head protection mechanism according to the embodiment of the present invention. FIG. 6 is a diagram for explaining the operation of the ink jet recording apparatus equipped with the recording head protection mechanism according to the embodiment of the present invention. FIG. 6 is a diagram for explaining the operation of the ink jet recording apparatus equipped with the recording head protection mechanism according to the embodiment of the present invention. It is a block diagram of the conveyance mechanism elevator 80. (A) It is a figure for demonstrating operation | movement of the conveyance mechanism elevator 80. FIG. (B) It is a figure for demonstrating operation | movement of the conveyance mechanism elevator 80. FIG. It is a figure which shows typically the structure of the inkjet recording device 100 by a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet recording device 10 Paper feed deck 10a Paper 10b Pickup roller 10c Paper separation roller pair 11 Registration roller 20 Conveyance mechanism 21 Drive roller 22 Driven roller 23 Tension roller 24 Conveyance belt 25 Housing part 30 Image forming part 31a-31d Recording head 40 Maintenance unit 41a-41d Cap 42 Main body 43 Moving roller 50 Maintenance unit moving mechanism 51, 52 Pulley 53 Wire 54 Rail 55 Maintenance unit elevator 55a Rotating shaft 60 Conveying mechanism elevator 60a Rotating shaft

Claims (4)

A cap unit having a cap that covers an ink discharge port of a recording head that performs recording with ink on a recording medium;
In conjunction with the relative movement of the recording head and the recording medium conveying unit having a conveying belt for conveying the recording medium to the recording head side and a driving roller for driving the conveying belt, the cap unit moves the recording medium to the recording head. A cap unit moving unit that moves between a position facing the head and a standby position on the upstream side of the conveyor belt;
The recording head protection mechanism, wherein the standby position of the cap unit is above a storage space in which the recording medium to be transported by the transport belt is stored. The recording medium is configured such that when the recording head is raised, the recording head is ready for recording on the recording medium, and when the recording head is lowered, the cap unit can move to a position sandwiched between the recording medium conveyance unit and the recording head. A recording medium conveyance unit elevating unit for elevating the conveyance unit in a direction facing the recording head;
The recording head and the cap unit are brought into contact so that the cap covers the ink discharge port of the recording head when the cap is raised, and the recording head and the cap unit are separated from each other when the cap is lowered. The recording head protection mechanism according to claim 1, further comprising a cap unit elevating unit that elevates and lowers the cap unit.   The recording head protection mechanism according to claim 1, further comprising a unit cover provided at the standby position and covering the cap unit. A recording medium conveying unit having a conveying belt for conveying the recording medium, and a driving roller for driving the conveying belt;
A recording head for recording with ink on the recording medium;
A storage unit for storing the recording medium;
An ink jet recording apparatus comprising: the recording head protection mechanism according to claim 1 that cooperates with the recording medium conveyance unit and the recording head.

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