JP5150073B2 - Inkjet recording device - Google Patents

Description

  The present invention relates to an ink jet recording apparatus.

  As a method of an ink jet recording apparatus that records information such as images by ejecting ink onto a recording sheet such as copy paper (hereinafter referred to as “recording paper”), a plurality of nozzles that eject ink are recorded. There is a line head method using a recording head (hereinafter referred to as “line head”) arranged at a length corresponding to the width of the paper. On the other hand, in the ink jet recording apparatus, a method of performing printing corresponding to the width of the recording paper by reciprocating a recording head having a width smaller than that of the recording paper in the width direction of the recording paper is called a serial method.

  A conventional line head type inkjet recording apparatus is used for the purpose of preventing ink drying and clogging in the nozzle when ink is not ejected from the nozzle during non-recording operation or when the power is turned off. An operation of covering the ink ejection side of the line head with a cap for covering the nozzle portion of the head is performed (hereinafter simply referred to as “capping”) (see, for example, Patent Document 1, FIG. 2 and FIG. 9).

  Hereinafter, capping of a conventional line head type ink jet recording apparatus will be described. FIG. 8 is a schematic cross-sectional view of a conventional line head type ink jet recording apparatus cut in a plane perpendicular to the width direction.

  The line head type inkjet recording apparatus 90 shown in FIG. 8 includes a line head unit 91 including four line heads 91a to 91d that respectively eject four color inks, and line heads 91a to 91a. It has a cap unit 92 for capping 91d and a transport belt portion 93 for transporting the recording paper.

  In the inkjet recording apparatus 90 shown in FIG. 8, the conveyance belt unit 93 conveys the recording paper placed on the upper side of the conveyance belt unit 93 in the drawing from the right side to the left side in the drawing. The line head unit 91 discharges ink onto the conveyed recording paper and records information such as an image on the recording paper.

  The cap unit 92 is formed so as to correspond to the outer shape of the line head unit 91, and in the standby space 94 that is secured in advance on the right side of the line head unit 91 in FIG. It is stored.

  Next, the operation at the time of capping of the conventional line head recording apparatus will be described. FIG. 9 is a diagram for explaining the operations of the line head unit 91 and the cap unit 92 during the capping operation. In FIG. 9, the display of the conveyance belt portion 93 is omitted.

  First, the line head unit 91 moves from the position shown in FIG. 8 to the upper side in FIG. Next, as shown in FIG. 9B, the cap unit 92 moves from the standby space 94 to the position of the line head unit 91 shown in FIG. Then, the line head unit 91 is capped by the cap unit 92 as the line head unit 91 moves downward in FIG. 9B.

  As described above, in the conventional line head type ink jet recording apparatus, capping is performed by moving the line head unit and the cap unit.

Incidentally, in a conventional line head type ink jet recording apparatus for double-sided printing, there is one in which a line head is formed using a recording head divided into three, which is smaller than the width of the recording paper (for example, patents) Reference 2). This line head type inkjet recording apparatus is intended to reduce the occurrence of clogging of nozzles of unused recording heads by switching the number of recording heads used according to the width of the recording paper. is there.
JP-A-4-284257 JP 7-314701 A

  However, the line head type inkjet recording apparatus 90 shown in FIG. 8 has the following problems.

  As described above, the cap unit 92 has substantially the same size as the line head unit 91 in order to cap the line heads 91a to 91d. Therefore, the standby space 94 in which the cap unit 92 waits during the recording operation needs to secure a space of almost the same size as the line head unit 91. As described above, the conventional line head type inkjet recording apparatus 90 has the cap unit 92 and the standby space 94 that are substantially the same size as the line head unit 91, and thus has a problem that the apparatus becomes large.

  Accordingly, an object of the present invention is to provide a line head type ink jet recording apparatus that can be reduced in size as compared with the conventional line head type ink jet recording apparatus.

In order to solve the above problems, the first aspect of the present invention provides:
A transport unit for transporting a recording sheet;
A plurality arranged line head unit nozzles line head having a plurality of recording heads arranged in a predetermined direction, along the front Symbol conveyance direction of the recording sheet for ejecting ink,
A plurality of caps corresponding to the plurality of recording heads for covering the nozzles;
A moving unit that changes a relative position between the recording head and the cap corresponding to the recording head in accordance with an ink discharging state in which the nozzle discharges ink and a cap state in which the nozzle is covered with the cap. and,
A support member for supporting the plurality of recording heads,
The plurality of recording heads of each of the line heads are divided and arranged along the width direction of the recording sheet, and all or some of the plurality of divided recording heads are arranged. Can be relatively translated in a state shifted from each other in the transport direction,
In the ink ejection state, the plurality of recording heads included in the line head are arranged so that the nozzles for each recording head do not overlap when viewed from the transport direction due to a change in the relative position by the moving unit.
In the cap state, the plurality of recording heads of the line head are arranged such that at least a part of the nozzles for each recording head overlap when viewed from the transport direction due to the change in the relative position by the moving unit. Covered by the plurality of caps in an arrayed state ,
The support member includes a plurality of the recording heads arranged at positions corresponding to each other among the plurality of divided recording heads constituting the plurality of line heads in the ink ejection state. The inkjet recording apparatus is fixed and supported while maintaining the relative positional relationship in the width direction .

The second aspect of the present invention
Wherein the plurality of caps is a position outside the conveying area of the recording sheet, it is movable only in a direction perpendicular to the transport surface of the recording sheet,
The moving unit moves each recording head in the width direction of the recording sheet to the position of the corresponding cap when changing from the ink ejection state to the cap state. Inkjet recording apparatus.

The third aspect of the present invention
The width of the recording head based on the width direction of the recording sheet is the same for all recording heads,
In the cap state, in the ink jet recording apparatus according to the second aspect of the present invention, all the recording heads are arranged in a state where both ends of the recording heads in the width direction are aligned.

The fourth aspect of the present invention is
The line head is an ink jet recording apparatus according to a third aspect of the present invention, having two recording heads.

The fifth aspect of the present invention provides
The line head unit is the ink jet recording apparatus according to any one of the first to fourth aspects of the present invention, which includes four line heads that discharge black, cyan, magenta, and yellow colors.

  According to the present invention, it is possible to provide a line head type ink jet recording apparatus that can be made smaller than before.

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

(Embodiment 1)
FIG. 1 is a schematic diagram of a cross section perpendicular to a recording paper conveyance direction (hereinafter simply referred to as a conveyance direction) of an inkjet recording apparatus capable of full-color printing in an embodiment of the present invention. The ink jet recording apparatus 1 shown in FIG. 1 includes a line head 11 that ejects black ink onto a recording sheet, a line head 12 that ejects cyan ink, a line head 13 that ejects magenta ink, and yellow ink. A line head 14 that discharges, a support member 15 that supports the line heads 11 to 14, drive shafts 21 and 22 that extend along the width direction of the recording paper (hereinafter simply referred to as the “width direction”), A bearing portion 23 that forms a ball screw, a bearing portion 24 that forms a drive shaft 22 and a ball screw, a slider shaft 25 and a slider bearing 26 for holding the support member 15 at a predetermined height, and line heads 11 to 11. 14 is provided facing the ink ejection surface, and transports the recording paper in the transport direction (from the right side to the left side in FIG. 1) while maintaining the flatness of the recording paper. And a conveyor belt unit 30 that.

  The line heads 11 to 14 constitute a line head unit. When the line heads 11 to 14 eject ink of each color, the inkjet recording apparatus 1 can perform full color printing. The line head 11 includes two recording heads 11a and 11b. Similarly, the line head 12 includes two recording heads 12a and 12b. The line head 13 is composed of two recording heads 13a and 13b. The line head 14 includes two recording heads 14a and 14b. In the following description, it is assumed that the recording heads 11a to 14a and 11b to 14b have the same shape.

  The support member 15, the drive shafts 21 and 22, the bearing portions 23 and 24, the slider shaft 25, and the slider bearing 26 will be described later.

  The conveyor belt unit 30 has a structure in which an endless conveyor belt 33 is wound between rollers 31 and 32. The conveyance belt unit 30 conveys the recording sheet inserted from the right side of FIG. 1 to the left side, and maintains the planar state of the recording sheet to be conveyed. In addition, illustration of a suction device etc. is abbreviate | omitted in the conveyance belt part 30 shown in FIG.

  Hereinafter, the configuration of the inkjet recording apparatus 1 in a recording state in which ink is ejected onto the recording paper will be described.

FIG. 2 is a schematic top view of the ink jet recording apparatus 1 in a recording state. In FIG. 2, the conveyance direction is the direction from the bottom to the top of FIG. Hereinafter, in the schematic top view of the ink jet recording apparatus, the transport direction is the bottom to top direction.
In addition to the configuration shown in FIG. 1, the inkjet recording apparatus 1 shown in FIG. 2 includes a support member 16 that supports the line heads 11 to 14, drive motors 27 and 28 that rotate the drive shafts 21 and 22, and a drive. A control unit 29 for controlling the motors 27 and 28 and a cap unit 41 for capping the recording heads 11a to 14a and 11b to 14b are provided.

  First, the recording heads constituting the line heads 11 to 14 will be described.

  First, the arrangement interval of the recording heads will be described. As shown in FIG. 1, the recording heads 11 a to 14 a and 11 b to 14 b are arranged with a predetermined gap from adjacent recording heads. This is to suppress contact between the adjacent recording heads during the recording operation and to prevent the recording heads from colliding with each other when the recording heads 11a to 14a and 11b to 14b described later move in the width direction. It is.

  Next, the arrangement of the recording heads constituting the line heads 11 to 14 will be described using the line head 11 as an example. As shown in FIG. 2, the recording heads 11a and 11b constituting the line head 11 are arranged along the width direction. Specifically, the recording head 11a is arranged on the left side of the line head 11 in FIG. 2, and the recording head 11b is arranged on the right side of the line head 11 in FIG.

  At this time, the recording heads 11a and 11b are arranged in a state shifted from each other in the transport direction, but as shown in FIG. 2, the right end 11aR of the recording head 11a and the left end 11bL of the recording head 11b Are overlapped when viewed from the transport direction.

  Since the arrangement of the recording heads constituting the line heads 12 to 14 is the same as the arrangement of the recording heads 11a and 11b constituting the line head 11, the description thereof is omitted.

  Next, support members 15 and 16 that support the line heads 11 to 14 will be described.

  First, the support member 15 will be described. The support member 15 is provided with a bearing portion 23 and a slider bearing 26. The support member 15 is supported by a drive shaft 21 that penetrates the bearing portion 23 and a slider shaft 25 that penetrates the slider bearing 26. Further, as shown in FIG. 2, the support member 15 holds the right side of the recording heads 11b to 14b.

  The drive shaft 21 is a male screw and is rotated by a drive motor 27. On the other hand, the bearing portion 23 is formed with a through hole penetrating in the width direction, and the through hole is a female screw. The drive shaft 21 and the bearing portion 23 constitute a ball screw. As a result, the support member 15 can move in the width direction. That is, the recording heads 11b to 14b can move in the width direction. In addition, about a ball screw, since a well-known technique is used, the detailed description is abbreviate | omitted.

  The slider bearing 26 provided in the support member 15 has a through hole penetrating in the width direction. The slider shaft 25 passes through the through hole. Since the diameter of the through hole of the slider bearing 26 is larger than the diameter of the slider shaft 25, the slider bearing 26 can freely move with respect to the slider shaft 25.

  Next, the support member 16 will be described. The support member 16 is provided with a bearing portion 24 and a slider bearing 26. The support member 15 is supported by a drive shaft 22 that penetrates the bearing portion 24 and a slider shaft 25 that penetrates the slider bearing 26. Further, as shown in FIG. 2, the support member 16 holds the left side of the recording heads 11a to 14a.

  The drive shaft 22 is a male screw and is rotated by a drive motor 28. On the other hand, the bearing portion 24 is formed with a through hole penetrating in the width direction, and the through hole is a female screw. The drive shaft 22 and the bearing portion 24 constitute a ball screw. As a result, the support member 16 can move in the width direction. That is, the recording heads 11a to 14a can move in the width direction.

  Next, the cap unit 41 will be described. The cap unit 41 is disposed on the right side of the transport belt 33 in FIG. 2 and is composed of eight caps 41a to 41h. The caps 41a to 41h correspond to the outer shapes of the recording heads 11a to 14a and 11b to 14b. That is, the caps 41a to 41h have the same shape. Further, the caps 41a to 41h are arranged in a line along the transport direction with both ends thereof aligned. For this reason, the width of the cap unit 41 is substantially half the width of the line heads 11 to 14 during the recording operation.

  The caps 41a to 41h have a one-to-one correspondence with the recording heads 11a to 14a and 11b to 14b, and are arranged on the right side in the width direction of the corresponding recording heads as shown in FIG. That is, the caps 41a and 41b are caps corresponding to the recording heads 11a and 11b, respectively. The caps 41c and 41d are caps corresponding to the recording heads 12a and 12b, respectively. The caps 41e and 41f are caps corresponding to the recording heads 13a and 13b, respectively. The caps 41g and 41h are caps corresponding to the recording heads 14a and 14b, respectively.

  The cap unit 41 is fixed with respect to the width direction and the conveyance direction, but is movable only in a direction perpendicular to the paper surface of FIG. FIG. 3 is a cross-sectional view taken along the line AA of the ink jet recording apparatus 1 shown in FIG. As shown in FIG. 3, the cap 41b is moved in the vertical direction in FIG. 3 by a drive unit (not shown) in accordance with the recording state and the capping state for capping the recording head. The cap 41b stands by at the position indicated by the solid line in the recording state, and moves to the cap position indicated by the dotted line in the cap state to perform capping on the recording head 11b. Note that the caps 41a and 41c to 41h are also movable in the vertical direction in FIG. 3, similarly to the cap 41b shown in FIG.

  In addition, the line head unit comprised by the line heads 11-14 is an example of the line head unit of this invention, and the recording heads 11a-14a and 11b-14b are examples of the some recording head of this invention, The transport belt unit 30 is an example of the transport unit of the present invention, the cap unit 41 is an example of the cap unit of the present invention, the drive shafts 21 and 22, the bearing units 23 and 24, the drive motors 27 and 28, The moving unit configured by the control unit 29 is an example of the moving unit of the present invention, the recording state is an example of the ink ejection state of the present invention, and the cap state is an example of the cap state of the present invention.

  Below, the operation | movement at the time of capping of the inkjet recording device 1 is demonstrated.

  FIG. 4 is a schematic top view of the inkjet recording apparatus 1 in the cap state. Hereinafter, the change in the arrangement of the recording head when the inkjet recording apparatus 1 changes from the recording state to the cap state will be described with reference to FIG.

  In the inkjet recording apparatus 1 shown in FIG. 4, the arrangement of the line heads 11 to 14 and the support members 15 and 16 in the recording state is indicated by dotted lines. The arrangement of the line heads 11 to 14 indicated by dotted lines and the support members 15 and 16 is the same as the arrangement shown in FIG. Further, the arrangement of the line heads 11 to 14 and the support members 15 and 16 in the cap state is indicated by a solid line. Further, the caps 41a to 41h (not shown in FIG. 4) are actually arranged at the back of the paper surface of the recording heads 11a to 14a and 11b to 14b.

  First, in the recording state, the recording heads 11a to 14a and 11b to 14b are arranged at positions indicated by dotted lines in FIG. 4 (state shown in FIG. 2).

  Next, in order to change from the recording state to the cap state, the control unit 29 drives only the drive motor 27 to rotate the drive shaft 21. As the drive shaft 21 rotates, the support member 15 moves to the right in the width direction of FIG. Then, when both ends of the recording heads 11b to 14b coincide with both ends of the caps 41b, 41d, 41f, and 41h, the control unit 29 stops the drive motor 27. As a result, the recording heads 11b to 14b move the distance d1 to the right in the width direction of FIG. 4 as shown in FIG.

  Next, the control unit 29 drives only the drive motor 28 to rotate the drive shaft 22. As the drive shaft 22 rotates, the support member 16 moves to the right in the width direction of FIG. Then, when both ends of the recording heads 11a to 14a coincide with both ends of the caps 41a, 41c, 41e, and 41g, the control unit 29 stops the drive motor 28. As a result, as shown in FIG. 4, the recording heads 11a to 14a move a distance d2 different from the distance d1 to the right in the width direction of FIG. The relationship between d1 and d2 is d1 <d2.

  Next, the drive unit (not shown) moves the cap unit 41 from the standby position to the cap position and capping the recording heads 11a to 14a and 11b to 14b, thereby completing the state change from the recording state to the cap state. To do.

  As a result of the ink jet recording apparatus 1 changing from the recording state to the cap state, the line heads 11 to 14 and the supporting members 15 and 16 change from the arrangement shown by the dotted line in FIG. 4 to the arrangement shown by the solid line. In the recording state, the right end portion 11aR of the recording head 11a and the left end portion 11bL (see FIG. 2) of the recording head 11b overlap each other when viewed from the transport direction, whereas in the cap state, as shown in FIG. The recording head 11a and the recording head 11b are completely overlapped when viewed from the transport direction. That is, the relative positions of the recording heads 11a and 11b change with the change from the recording state to the cap state. Further, when the caps 41a to 41h move from the standby position to the cap position, the relative positions of the recording heads 11a and 11b and the caps 41a and 41b also change. The description of the recording heads 11a and 11b constituting the line head 11 can be similarly applied to the line heads 12 to 14.

  When the inkjet recording apparatus 1 changes from the cap state to the recording state, an operation in the reverse order to the above-described operation is performed.

  In this way, the plurality of divided recording heads constituting one line head move at different distances to change the relative positions of the plurality of recording heads, thereby arranging the caps 41a to 41 arranged in a line. Capping by 41h is possible. That is, unlike the conventional cap unit, the cap unit 41 is approximately half the width of the line head unit. Further, the standby space of the cap unit and the cap unit 41 are about half the width of the line head unit. Therefore, the ink jet recording apparatus of the present embodiment can reduce the cap unit and the standby space, and can be downsized.

  Finally, changes in the state of the nozzles formed on the line head between the recording state and the cap state will be described. FIG. 5 is a diagram illustrating the state of the nozzles in the recording state and the cap state of the inkjet recording apparatus 1.

  In FIG. 5, for convenience of explanation, both the line heads 11 to 14 in the recording state and the line heads 11 to 14 in the cap state are shown side by side. FIG. 5 shows that the line heads 11 to 14 in the recording state are above the conveyance belt 33 (left side in FIG. 5). The line heads 11 to 14 in the cap state are illustrated at the position of the cap unit 41 (see FIG. 2) (the right side in FIG. 5). Further, in each recording head shown in FIG. 5, it is assumed that a plurality of nozzles for ejecting ink are arranged in a line along the width direction and formed in the shaded portion of each recording head. Further, in FIG. 5, the support members 15 and 16 are not shown.

  First, the arrangement state of the nozzles of the line head 11 in the recording state will be described. When the line head 11 in the recording state shown on the left side in FIG. 5 is viewed from the transport direction, the right end 11aR of the recording head 11a and the left end 11bL of the recording head 11b overlap. However, the nozzle array 51a formed on the recording head 11a and the nozzle array 51b formed on the recording head 11b do not overlap when viewed from the transport direction. As a result, in the recording state, the nozzle row 51a and the nozzle row 51b can eject ink in accordance with the width of the recording paper, and the plurality of nozzles constituting one line head are the same on the recording paper. Ink is not ejected to the dots.

  At this time, if the width of the nozzle rows 51a and 51b is w1, the width of the nozzle row of the line head 11 in the recording state is 2 × w1. The nozzle rows 51a and 51b overlap with the nozzle rows of the recording heads of the other line heads as viewed from the transport direction, but the nozzles of the recording heads of the other line heads discharge different color inks. There is no problem.

  Next, the arrangement state of the nozzles of the cap-shaped line head 11 will be described. When the cap-shaped line head 11 shown on the right side of FIG. 5 is viewed from the carrying direction, the both ends of the recording head 11a and the both ends of the recording head 11b coincide. That is, the nozzle row 51a and the nozzle row 51b are completely overlapped when viewed from the transport direction. At this time, the width of the nozzle of the capped line head 11 is w1, which matches the width of the nozzle rows 51a and 51b.

  The above description regarding the change in the state of the nozzles in the line head 11 can be similarly applied to the line heads 12 to 14.

(Embodiment 2)
FIG. 6 is a schematic top view of the ink jet recording apparatus 2 in a recording state according to an embodiment of the present invention. In the description of the ink jet recording apparatus 2 of the present embodiment, the same reference numerals are assigned to the same components as those of the ink jet recording apparatus 1 of the first embodiment.

  First, main differences between the inkjet recording apparatus 1 and the inkjet recording apparatus 2 will be described. In the inkjet recording apparatus 1, the line heads 11 to 14 are each composed of two recording heads, whereas in the inkjet recording apparatus 2, the line heads 11 to 14 are each composed of four recording heads. The point is different.

  Hereinafter, the ink jet recording apparatus 2 will be described focusing on the above differences.

  In the ink jet recording apparatus 2 shown in FIG. 6, the line head 11 is divided into four recording heads 11a to 11d. The recording heads 11a to 11d are arranged in the order of the recording heads 11a, 11b, 11c, and 11d from the left side to the right side in FIG. The recording heads 11a to 11d are arranged in two rows along the width direction. Specifically, the recording heads 11a and 11c are arranged in the upper row in FIG. 6, and the recording heads 11b and 11d are arranged in the lower row in FIG.

  The line head 12 is divided into four recording heads 12a to 12d. The line head 13 is divided into four recording heads 13a to 13d. The line head 14 is divided into four recording heads 14a to 14d. Note that the arrangement of the recording heads constituting the line heads 12 to 14 in the recording state is the same as that of the recording heads 11a to 11d constituting the line head 11, and the description thereof is omitted.

  Next, the support members 15 to 18 will be described. The support member 15 supports the right side of the recording heads 11c to 14c in FIG. 6 and is held by a drive shaft 21a rotated by a drive motor 27a and a slider shaft 25. The support member 16 supports the left side of the recording heads 11 b to 14 b and is held by a drive shaft 21 b that is rotated by a drive motor 27 b and a slider shaft 25. The support member 17 supports the right side of the recording heads 11 d to 14 d and is held by a drive shaft 21 c that is rotated by a drive motor 27 c and a slider shaft 25. The support member 18 supports the left side of the recording heads 11a to 14a and is held by a drive shaft 21d rotated by a drive motor 27d and a slider shaft 25. The control unit 29 individually controls the drive motors 27a to 27d. For this reason, the support members 15 to 18 can move independently in the width direction.

  Next, the cap units 41 to 44 will be described. In FIG. 6, a description will be given assuming that a cap unit is provided for each line head. The cap units 41 to 44 are provided on the right side of the conveyor belt 33 in FIG. 6 corresponding to the line heads 11 to 14. The cap unit 41 is a cap unit corresponding to the line head 11 and includes caps 41a to 41d that perform capping corresponding to the recording heads 11a to 11d, respectively. The cap unit 42 includes caps 42a to 42d for capping corresponding to the recording heads 12a to 12d, respectively. The cap unit 43 is composed of caps 43a to 43d for capping corresponding to the recording heads 13a to 13d, respectively. The cap unit 44 is composed of caps 44a to 44d for capping corresponding to the recording heads 14a to 14d, respectively. As shown in FIG. 6, the caps constituting the cap units 41 to 44 are arranged in a state where two sets of caps arranged along the width direction are arranged in eight sets along the conveyance direction.

  The operation of the inkjet recording apparatus 2 in FIG. 6 having the above-described configuration changing from the recording state to the cap state will be described.

  First, in the recording state, the recording heads constituting the line heads 11 to 14 are arranged in the state shown in FIG. At this time, the state of the nozzle arrays of the recording heads constituting the line heads 11 to 14 is the same as that in the first embodiment, and is omitted.

  Next, when the control unit 29 drives the drive motor 27a, the support member 15 moves to the right side in FIG. As the support member 15 moves, the recording heads 11c to 14c move the distance d1 to the right in the width direction and move right above the caps 41c to 44c (front side in FIG. 6). Next, when the control unit 29 drives the drive motor 27b, the support member 16 moves to the right side of FIG. As the support member 16 moves, the recording heads 11b to 14b move a distance d2 to the right in the width direction, and move right above the caps 41b to 44b (front side in FIG. 6).

  Next, when the control unit 29 drives the drive motor 27c, the support member 17 moves to the right side in FIG. As the support member 16 moves, the recording heads 11d to 14d move a distance d3 to the right in the width direction, and move right above the caps 41d to 44d (front side in FIG. 6). Next, when the control unit 29 drives the drive motor 27d, the support member 18 moves to the right side in FIG. As the support member 16 moves, the recording heads 11a to 14a move the distance d4 to the right in the width direction and move right above the caps 41a to 41a (front side in FIG. 6).

  After each recording head moves, the cap units 41 to 44 move from the standby position to the cap position. Thereby, each recording head is capped, and the inkjet recording apparatus 2 is in a cap state. Since the state of the nozzle rows formed in each recording head in the cap state is the same as that in the first embodiment, the description thereof is omitted.

  In the above-described embodiment, the caps 41a to 41h constituting the cap unit 41 have been described as being arranged in a line in a state in which both end portions thereof coincide with each other. However, the present invention is not limited thereto, and for example, the cap 41a -41h may be arranged in a state where both ends do not match.

  FIG. 7 is a diagram illustrating another example of the arrangement of the caps 41 a to 41 h in the inkjet recording apparatus 1. As illustrated in FIG. 7, the caps 41 a to 41 h are arranged along the transport direction, but both end portions of the caps 41 a to 41 h do not match when viewed from the transport direction. As a result, both ends of the recording heads 11a and 11b in the cap state and both ends of the nozzle rows 51a and 51b do not match.

  However, the nozzle rows 51a and 51b in the cap state shown in FIG. 7 are in a state where a part thereof overlaps when viewed from the transport direction. As shown in FIG. 7, the width of the portion where the nozzle rows 51a and 51b overlap is w3 (where w3 <w1), and the width of the nozzle row of the line head 11 in the cap state is w2 (where w2 < 2 × w1). Thus, in the cap state, as long as the nozzle rows 51a and 51b overlap each other when viewed from the transport direction, the both ends of the caps 41a to 41h do not have to coincide with each other. That is, it is only necessary that the caps 41a to 41h be arranged so that the width of the line heads 11 to 14 in the cap state is smaller than the width of the line heads 11 to 14 in the recording state.

  In the above embodiment, one line head is divided into two or four recording heads. However, the present invention is not limited to this. For example, one line head is divided into three or five or more recording heads. May be.

  Moreover, in the said embodiment, although the example where the cap unit which comprises a cap unit was arranged in two rows was demonstrated, it is not restricted to this, For example, two caps arranged in two rows are made into one It may be formed as a cap. Specifically, the caps 41a and 41b shown in FIG. 6 may be formed as one cap.

  In the second embodiment, the description has been given of the configuration in which a part of the plurality of recording heads constituting the line head is moved in parallel in a state shifted in the transport direction. A configuration may be adopted in which all of the recording heads are translated in a state shifted in the transport direction. For example, in the inkjet recording apparatus 2 illustrated in FIG. 6, all the recording heads 11 a to 11 d configuring the line head 11 may be configured to move in parallel while being shifted from each other in the transport direction. In this case, the caps of the cap units 41 to 44 shown in FIG. 6 are arranged in a line along the transport direction. Therefore, the width of the cap unit can be further reduced.

  Moreover, in the said embodiment, although the control part 29 demonstrated as what drives the drive shafts 21 and 22 separately, not only this but the control part 29, for example, the drive shafts 21 and 22 are changed. You may rotate simultaneously.

  In the above embodiment, the nozzle row formed in the recording head has been described as the nozzles arranged in a row along the width direction. However, the present invention is not limited to this, and for example, the recording head is arranged in the width direction. It may have a plurality of nozzle rows arranged in a line along the line, or a predetermined nozzle arrangement pattern may be repeated.

  In the above embodiment, the nozzle rows formed in each recording head in the recording state are described as not overlapping when viewed from the transport direction. However, a part of the nozzle rows formed in each recording head in the recording state However, they may overlap when viewed from the transport direction.

  For example, in the line head 11 shown in FIG. 5, the right end portion of the nozzle row 51a of the recording head 11a and the left end portion of the nozzle row 51b of the recording head 11b may overlap each other when viewed from the transport direction. In this case, the ink jet recording apparatus according to the above embodiment controls the recording head 11b to stop the discharge of ink from the overlapping portion of the nozzle row 51b, thereby uniformizing the resolution of the line head in the recording state. It may be. That is, in the line head in the recording state, the nozzles that actually eject ink overlap when viewed from the transport direction even though some of the nozzle arrays formed on the plurality of print heads overlap when viewed from the transport direction. If you don't,

  In addition, even if some of the nozzle arrays formed on the plurality of recording heads overlap each other when viewed from the transport direction, the ink jet recording apparatus according to the above embodiment does not discharge ink from the overlapping nozzle arrays. By controlling the above, the resolution of the line head in the recording state may be made uniform.

  In this way, when a part of the nozzle rows formed in the two recording heads overlaps when viewed from the transport direction, a plurality of adjacent recording heads are made uniform by making the resolution of the line heads uniform in the recording state. As a result, it is not necessary to strictly align the position of the line head, so that the assembly of the line head can be facilitated.

  In the above embodiment, the cap unit is described as being fixed in the transport direction and the width direction. However, the cap unit 41 is not limited to this, and the cap unit 41 changes from the recording state to the cap state. You may move also in a conveyance direction and / or a width direction.

  In the above embodiment, the ink jet recording apparatus is described as being capable of full color printing. However, the present invention is not limited to this, and for example, an ink jet recording apparatus configured with one line head and capable of printing only in a single color. It may be an ink jet recording apparatus having a line head unit composed of two, three, or five or more line heads.

  In the above embodiment, the recording heads constituting the line head have been described as having the same shape. However, the present invention is not limited to this, and the widths of the recording heads constituting the line head may be different. .

  The ink jet recording apparatus according to the present invention can provide a line head type ink jet recording apparatus that can be reduced in size as compared with the prior art, and is useful as an ink jet recording apparatus or the like.

FIG. 4 is a schematic cross-sectional view taken along a plane parallel to the recording paper conveyance direction in the inkjet recording apparatus according to the first embodiment. Schematic top view of the ink jet recording apparatus 1 in a recording state AA sectional view of the ink jet recording apparatus 1 shown in FIG. Schematic top view of the inkjet recording apparatus 1 in a cap state The figure which shows the state of the nozzle in the recording state of the inkjet recording device 1, and a cap state. Schematic top view of the ink jet recording apparatus 2 of the second embodiment The figure which shows the other example of the arrangement | sequence of the caps 41a-41h Schematic diagram of a cross-section of a conventional inkjet recording device cut in a clear perpendicular to the width direction (A) The figure explaining the movement state of the line head unit 91, (b) The figure explaining the movement state of the cap unit 92

Explanation of symbols

11, 12, 13, 14 Line heads 11a-11d, 12a-12d, 13a-13d, 14a-14d Recording head 11aR Right end 11bL of recording head 11a Left end 15-15 of recording head 11b Support members 21, 21a ˜21d, 22 Drive shaft 23, 24 Bearing portion 25 Slider shaft 26 Slider bearing portion 27, 27a-27d, 28 Drive motor 29 Control portion 30 Conveying belt portion 31, 32 Roller 33 Conveying belt 41-44 Cap units 41a-41h, 42a-42d, 43a-43d, 44a-44d Cap 51a-51b Nozzle row

Claims (5)

A transport unit for transporting a recording sheet;
A plurality arranged line head unit nozzles line head having a plurality of recording heads arranged in a predetermined direction, along the front Symbol conveyance direction of the recording sheet for ejecting ink,
A plurality of caps corresponding to the plurality of recording heads for covering the nozzles;
A moving unit that changes a relative position between the recording head and the cap corresponding to the recording head in accordance with an ink discharging state in which the nozzle discharges ink and a cap state in which the nozzle is covered with the cap. and,
A support member for supporting the plurality of recording heads,
The plurality of recording heads of each of the line heads are divided and arranged along the width direction of the recording sheet, and all or some of the plurality of divided recording heads are arranged. Can be relatively translated in a state shifted from each other in the transport direction,
In the ink ejection state, the plurality of recording heads included in the line head are arranged so that the nozzles for each recording head do not overlap when viewed from the transport direction due to a change in the relative position by the moving unit.
In the cap state, the plurality of recording heads of the line head are arranged such that at least a part of the nozzles for each recording head overlap when viewed from the transport direction due to the change in the relative position by the moving unit. Covered by the plurality of caps in an arrayed state ,
The support member includes a plurality of the recording heads arranged at positions corresponding to each other among the plurality of divided recording heads constituting the plurality of line heads in the ink ejection state. An ink jet recording apparatus that is fixedly supported while maintaining the relative positional relationship in the width direction . Wherein the plurality of caps is a position outside the conveying area of the recording sheet, it is movable only in a direction perpendicular to the transport surface of the recording sheet,
The said moving unit moves each said recording head to the position of the said corresponding cap in the width direction of the said recording sheet, when changing from the said ink discharge state to the said cap state. Inkjet recording device. The width of the recording head based on the width direction of the recording sheet is the same for all recording heads,
3. The ink jet recording apparatus according to claim 2, wherein in the cap state, all the recording heads are arranged in a state in which both end portions of the recording heads in the width direction are aligned.   The inkjet recording apparatus according to claim 3, wherein the line head includes two recording heads.   5. The ink jet recording apparatus according to claim 1, wherein the line head unit includes four line heads that discharge black, cyan, magenta, and yellow colors. 6.

Images