JP2013052533A - Liquid ejection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the deviation a nozzle in a predetermined direction between liquid ejection heads when a mounting member to which a nozzle head with a plurality of nozzle arrays is mounted is expanded due to the rise in temperature.SOLUTION: Four inkjet heads 12 each of which includes a plurality of nozzles 31 forming a nozzle array 32 by being arranged in a paper width direction are arranged in line in the paper width direction on an upper surface of a head holding plate 11. The head holding plate 11 is mounted on a fixing part 21 fixed to a printer body 1a through a hinge 22, and can be rotated around a rotation shaft 22a of the hinge 22. The end surface at one side in the paper width direction of the head holding plate 11 is substantially circular in plan view, and a curved surface 11a in contact with a guide member 23 of a substantial cylindrical brain. When the head holding plate 11 is extended in the paper width direction due to the rise in temperature, the guide surface 11a is pressed by the guide member 23, and thus, the head holding plate 11 is rotated around the rotation shaft 22a.

Description

  The present invention relates to a liquid ejecting apparatus that ejects liquid from a nozzle.

  In the printer described in Patent Document 1, a head unit as a liquid ejection head having a plurality of nozzles arranged in the paper width direction is arranged as a holding member in a state of being arranged along the paper width direction as the first direction. One line head unit is formed by being attached to the base frame. Then, ink is ejected from a plurality of nozzles of the plurality of head units onto a sheet conveyed in a conveyance direction orthogonal to the sheet width direction, thereby printing on the sheet.

JP 2008-114411 A

  In the printer described in Patent Document 1, when the temperature of the base frame rises due to an increase in environmental temperature or the like, the base frame expands and extends in the paper width direction or the like. When the base frame extends in the paper width direction, the position of the nozzles shifts in the paper width direction between the head units. When printing is performed in this state, the landing position of the ink on the paper also shifts in the paper width direction, and ink is printed on the printed image. The print quality is deteriorated, for example, by forming a streak-like region extending in the transport direction in which the ink does not land. In addition, since the printer described in Patent Document 1 performs printing by ejecting ink from a plurality of nozzles of a fixed head unit onto paper that is transported in the transport direction, the ink is ejected from the nozzles. Even if the timing is adjusted, the ink landing position in the paper width direction cannot be corrected.

  An object of the present invention is to provide a liquid ejection apparatus capable of reducing the displacement of the nozzle position in a predetermined direction between liquid ejection heads even when the temperature rises.

  The liquid ejection device according to the first invention has a plurality of nozzles arranged in a first direction which is a predetermined one direction, and the nozzle surfaces on which the plurality of nozzles are formed are on the same surface. A plurality of liquid ejection heads arranged along the first direction; and a plurality of liquid ejection heads attached thereto, and attachment members rotatably supported on a rotation axis that intersects the nozzle surface; Rotating means for rotating the attachment member expanded / contracted due to temperature change about the rotation shaft by an angle corresponding to the expansion / contraction amount in the first direction, and the attachment member being rotated by the rotation means. A landing position correcting means for correcting a landing position of the liquid discharged from the plurality of nozzles on a discharge target with respect to a direction intersecting with the first direction when viewed from a direction orthogonal to the nozzle surface. Preparation And said that you are.

  When the attachment member expands and contracts in the first direction due to a temperature change, the position of the nozzle is shifted with respect to the first direction between the plurality of liquid ejection heads. However, according to the present invention, when the mounting member expands and contracts due to a temperature change, the mounting member rotates about a rotation axis orthogonal to the nozzle surface, so that the displacement of the nozzle in the first direction between the liquid ejection heads is reduced. The

  At this time, the nozzle is also displaced in the direction intersecting the first direction by the rotation of the mounting member. However, by adjusting the liquid discharge timing from the nozzle by the landing position adjusting means, it is possible to correct the shift of the liquid landing position on the discharge target due to the shift of the nozzle.

  The liquid ejection device according to a second aspect is the liquid ejection device according to the first aspect, wherein the rotation shaft is located at a central portion of a region of the attachment member where the plurality of liquid ejection heads are attached. It is provided.

  According to the present invention, since the rotation center of the mounting member is close to the nozzle, the movement amount of the nozzle due to the rotation of the mounting member is small, and the correction amount of the landing position can be small. Therefore, the landing position of the liquid can be corrected with high accuracy.

  A liquid ejection apparatus according to a third aspect is the liquid ejection apparatus according to the first aspect, wherein the plurality of liquid ejection heads eject ink for high-quality printing from the plurality of nozzles in the first direction. A plurality of high-quality print heads arranged along the first direction, and a plurality of low-quality print heads that discharge low-quality print ink from the plurality of nozzles and are arranged along the first direction. The rotating shaft is provided in a region of the mounting member where the high-quality printing head is disposed.

  According to the present invention, since the rotation center of the mounting member is located near the nozzle that ejects the high-quality printing ink, the amount of movement of the nozzle that ejects the high-quality printing ink by the rotation of the mounting member is small. The correction amount of the landing position with respect to the nozzle for discharging the high-quality printing ink can be small. Therefore, it is possible to accurately correct the landing position of the high-quality printing ink that requires higher landing position accuracy than the low-quality printing ink.

  A liquid ejection apparatus according to a fourth invention is the liquid ejection apparatus according to the third invention, wherein the plurality of low-quality printing heads eject black ink as the low-quality printing ink from the plurality of nozzles. The plurality of high-quality print heads discharge color ink as the high-quality print ink from the plurality of nozzles.

  According to the present invention, since the rotation center of the attachment member is close to the nozzle that discharges the color ink, the amount of movement of the nozzle that discharges the color ink by the rotation of the attachment member is small, and the color ink is discharged. The correction amount of the landing position with respect to the nozzle to be discharged is small. Therefore, it is possible to accurately correct the landing position of the color ink that requires higher landing position accuracy than the black ink.

  The liquid ejection device according to a fifth aspect of the present invention is the liquid ejection device according to any one of the first to fourth aspects of the invention, in which the rotating means extends the mounting member in the first direction due to a temperature rise. Conversion means for converting the turning force of the mounting member into a second direction around the rotation axis, and biasing means for biasing the mounting member in a direction opposite to the second direction. It is characterized by being.

  According to the present invention, when the temperature of the attachment member rises, the extension of the attachment member in the first direction due to the temperature rise is converted into the rotational force of the attachment member in the second direction, so that the attachment member rotates. It rotates in the second direction around the axis. On the other hand, when the temperature of the attachment member decreases, the attachment member is rotated in the direction opposite to the second direction by the biasing means. Therefore, without providing a drive source such as a motor, the attachment member that expands and contracts due to a temperature change can be rotated by an angle corresponding to the expansion and contraction amount.

  A liquid ejection device according to a sixth aspect of the invention is the liquid ejection device according to any one of the first to fourth aspects, further comprising temperature detection means for detecting the temperature of the attachment member, wherein the rotation means is the The mounting member is rotated by an angle corresponding to the temperature detected by the temperature detecting means.

  According to the present invention, since the mounting member is rotated according to the temperature of the mounting member, the mounting member that expands and contracts due to a temperature change can be rotated by an angle corresponding to the expansion / contraction amount.

  According to a seventh aspect of the present invention, there is provided the liquid ejection device according to any one of the first to sixth aspects, wherein the plurality of liquid ejection heads are arranged before and after the attachment member is rotated by the rotation means. The apparatus further comprises holding means for holding the plurality of liquid discharge heads so that the direction does not change.

  According to the present invention, since the orientation of the liquid discharge head does not change before and after the mounting member is rotated, the nozzle interval in the paper width direction in each liquid discharge head does not vary.

  A liquid ejection apparatus according to an eighth invention is the liquid ejection apparatus according to any one of the first to seventh inventions, wherein the plurality of liquid ejection heads are at a temperature within a predetermined guaranteed operating temperature range. The liquid is normally discharged from the plurality of nozzles, and the attachment member is rotated by the rotation means at least in a state where the temperature is within a predetermined guaranteed operating temperature range. It is possible.

  According to the present invention, in a state where the mounting member is at least at a temperature within the guaranteed operating temperature range, it can be rotated by the rotating means, so that the liquid can be normally discharged from the nozzle of the liquid discharge head. As long as the mounting member can be rotated by an angle corresponding to its temperature.

  According to the present invention, when the mounting member expands and contracts due to a temperature change, the mounting member rotates about the rotation axis orthogonal to the nozzle surface, so that the displacement of the nozzle in the first direction between the liquid ejection heads is reduced. .

1 is a schematic configuration diagram of a printer according to an embodiment of the present invention. 2A and 2B are plan views of the head unit of FIG. 1, in which FIG. 1A shows a state before the head holding plate is rotated, and FIG. 1B shows a state after the head holding plate is rotated. It is the III-III sectional view taken on the line of FIG. It is a functional block diagram of the control apparatus of FIG. It is a figure explaining the space | interval of the nozzle between inkjet heads. FIG. 10 is a view corresponding to FIG. FIG. 10 is a view corresponding to FIG. FIG. 10 is a block diagram corresponding to FIG. FIG. 10 is a diagram corresponding to FIG. FIG. 10 is a diagram corresponding to FIG.

  Hereinafter, preferred embodiments of the present invention will be described.

  As shown in FIG. 1, the printer 1 according to the present embodiment includes a head unit 2, a paper transport roller 3, a temperature sensor 4 as temperature detecting means, and the like. The operation of the printer 1 is controlled by the control device 50.

  The head unit 2 is provided as a so-called line head, and ejects ink as a liquid from a plurality of nozzles 31 formed on the lower surface thereof. The paper conveyance rollers 3 are respectively arranged on the upper side and the lower side in FIG. 1 of the head unit 2 and convey the recording paper P in the paper feeding direction. The temperature sensor 4 is disposed in the vicinity of the head unit 2 and detects the temperature of the head unit 2. Specifically, the temperature sensor 4 detects a temperature of a head holding plate 11 described later or an environmental temperature in the vicinity of the head unit 2.

  In the printer 1, printing is performed on the recording paper P by ejecting ink from the nozzles 31 of the head unit 2 onto the recording paper P conveyed in the paper feeding direction by the paper conveying roller 3.

  Next, the head unit 2 will be described in detail. As shown in FIGS. 1 to 3, the head unit 2 includes a head holding plate 11 as an attachment member and four inkjet heads 12 as liquid ejection heads.

  The head holding plate 11 is a substantially rectangular plate-like body made of a metal material, a synthetic resin material, or the like and having a paper width direction as a first direction orthogonal to the paper feed direction as a longitudinal direction. Further, a fixing portion 21 fixed to the printer main body 1 a is provided on the left side of the head holding plate 11 in FIG. 1, and the upper left corner of the head holding plate 11 in FIG. Are attached to the fixed portion 21. Thereby, it can rotate centering on the rotating shaft 22a of the hinge 22 extended in the perpendicular direction which is a perpendicular | vertical direction of the paper surface of FIG. Further, when the head holding plate 11 becomes a predetermined temperature or less, the end surface on the hinge 22 side in the longitudinal direction comes into contact with the fixing portion 21 so that the head holding plate 11 does not rotate in the clockwise direction from the position shown in FIG. It has become. Here, the predetermined temperature is a temperature lower than the lower limit of the guaranteed operating temperature range that is a temperature range in which ink can be normally ejected in the inkjet head 12 that ejects ink from the nozzles 31 as will be described later. Therefore, the head holding plate 11 can rotate around the rotation shaft 22a at least in a state where the temperature is within the guaranteed operating temperature range.

  Further, the end surface of the head holding plate 11 on the side opposite to the fixing portion 21 is a guide surface 11a having a substantially arc shape in plan view, which is curved so that the upper portion in FIG. Yes. The guide surface 11a is disposed on the right side of the head holding plate 11 in FIG. 1 and is in contact with the outer peripheral surface of a substantially cylindrical guide member 23 extending in the vertical direction. Further, the head holding plate 11 is urged in the paper feed direction at the end opposite to the fixed portion 21 by a spring 24 as urging means, as indicated by an arrow A. Thereby, the head holding plate 11 supported by the rotating shaft 22a is urged in the clockwise direction of FIG.

  Further, four through holes 25 are formed in the head holding plate 11. Each of the four through holes 25 is a substantially rectangular hole whose longitudinal direction is the paper width direction, and is arranged in a line along the paper width direction.

  Each of the four inkjet heads 12 includes a plurality of nozzles 31 on a nozzle surface 12 a that is the lower surface thereof, and ejects ink from the plurality of nozzles 31. A plurality of nozzles 31 of each inkjet head 12 form a nozzle row 32 by being arranged in the paper width direction. In addition, at least a portion where the nozzle 31 is formed in the inkjet head 12 is made of a material having a smaller linear expansion coefficient than the head holding plate 11 such as silicon. Specifically, for example, when the inkjet head 12 is formed by laminating a plurality of plates, the nozzle plate forming the nozzle is made of a material having a smaller linear expansion coefficient than the head holding plate 11. Has been. The four inkjet heads 12 having such a configuration are arranged so that the nozzle surfaces 12a of the four inkjet heads 12 are exposed from the four through holes 25 and are positioned on the same horizontal plane. Attached to the upper surface in a line along the paper width direction.

  Each of the four inkjet heads 12 is connected to an ink cartridge 35 via a tube 34, and ink for discharging from a plurality of nozzles 31 is supplied from the ink cartridge 35 to the inkjet head 12.

  Next, the control device 50 that controls the operation of the printer 1 will be described. The control device 50 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, and as shown in FIG. 4, these are a correction amount storage unit 51, a print control unit 52, and the like. Works as.

  The correction amount storage unit 51 stores the relationship between the temperature of the head holding plate 11 or the ambient temperature in the vicinity of the head holding plate 11 and the correction amount of the discharge timings of the plurality of nozzles 31. The print control unit 52 controls the operation of the inkjet head 12 when printing is performed in the printer 1. Specifically, the print control unit 52 reads the correction amount of the discharge timing corresponding to the temperature detected by the temperature sensor 4 from the correction amount storage unit 51, and reads the discharge timing when the correction is not performed. Ink is ejected from the nozzles 31 by shifting the ejection timing by the correction amount. The print control unit 52 also controls the operation of the paper transport roller 3. In the present embodiment, the combination of the temperature sensor 4, the correction amount storage unit 51, and the print control unit 52 corresponds to the landing position correction unit according to the present invention.

  Here, when the temperature of the head holding plate 11 rises due to a change in environmental temperature or the like, the head holding plate 11 expands, and the expanded head holding plate 11 also extends in the paper width direction. At this time, if there is no guide surface 11a or guide member 23, the inkjet heads 12 are separated in the paper width direction. As shown in FIG. 5B, the interval W2 between the nozzles 31 in the paper width direction between the plurality of inkjet heads 12 is the interval between the nozzles 31 before the head holding plate expands as shown in FIG. It becomes larger than W1. That is, the nozzles 31 are displaced in the paper width direction between the inkjet heads 12, and the interval between the nozzles 31 in the paper width direction is increased. If the interval between the nozzles 31 in the paper width direction increases between the ink jet heads 12, when the printer 1 performs printing, the ink that extends linearly in the paper feed direction does not land on the recording paper P. An area is created, leading to a decrease in print quality. Further, the deviation of the nozzle 31 in the paper width direction as described above cannot be corrected by adjusting the timing of ink ejection from the nozzle 31.

  On the other hand, in the present embodiment, the guide surface 11 a of the head holding plate 11 is in contact with the guide member 23. Therefore, when the head holding plate 11 expands due to a temperature rise and extends in the paper width direction, the guide surface 11a of the head holding plate 11 is pressed radially inward by the guide member 23, and by the pressing force, The guide surface 11 a slides with the outer peripheral surface of the guide member 23. As a result, the head holding plate 11 rotates counterclockwise in FIG. 2 as the second direction around the rotation shaft 22a of the hinge 22 against the urging force of the spring 24, and FIG. As shown in FIG. 4, the posture is inclined with respect to the paper width direction. That is, in the present embodiment, the head holding plate 11 is rotated by converting the extension of the head holding plate 11 in the paper width direction into the rotational force of the head holding plate 11 in the second direction. In the present embodiment, the combination of the guide surface 11a and the guide member 23 corresponds to the conversion means according to the present invention. Further, since the rotation angle of the head holding plate 11 is determined by the temperature of the head holding plate 11 and the curvature of the outer peripheral surface of the guide surface 11a and the guide member 23, the curvature of the outer peripheral surface of the guide surface 11a and the guide member 23 is appropriately set. If so, the head holding plate 11 can be rotated by an appropriate angle corresponding to the temperature.

  Then, as the head holding plate 11 is rotated, as shown in FIG. 5C, the interval W3 of the nozzles 31 in the paper width direction between the inkjet heads 12 is the head holding plate shown in FIG. 5B. This is smaller than the interval W2 of the nozzles 31 in the paper width direction between the inkjet heads 12 when 11 is not rotated. Thereby, the shift | offset | difference of the nozzle 31 regarding the paper width direction between the inkjet heads 12 when the head holding | maintenance board 11 expand | swells can be reduced.

  Here, as described above, when the head holding plate 11 expanded by the temperature rise rotates, as can be understood from a comparison between FIG. 5A and FIG. The position is shifted in the paper feed direction. Therefore, in this embodiment, the correction amount of the ejection timing is read from the correction amount storage unit 51 according to the temperature detected by the temperature sensor 4, and the ejection timing of the ink from each nozzle 31 is shifted by the read correction amount. ing. Thereby, it is possible to correct the deviation of the landing position in the paper feeding direction.

  On the other hand, when the expanded head holding plate 11 contracts to its original size due to a temperature drop, the head holding plate 11 also contracts in the longitudinal direction. Thereby, the head holding plate 11 is rotated in the clockwise direction of FIG. 2, that is, in the direction opposite to the second direction by the pressing force of the spring 24, and returns to the original posture.

  In the present embodiment, as described above, the extension of the head holding plate 11 in the paper width direction is converted into the rotational force of the head holding plate 11 in the counterclockwise direction in FIG. 11 rotates in this direction. On the other hand, when the head holding plate 11 contracts in the paper width direction, the head holding plate 11 is rotated in the clockwise direction of FIG. Therefore, the head holding plate 11 can be rotated by an angle corresponding to the amount of expansion and contraction without providing a drive source such as a motor, and the configuration of the printer 1 can be simplified.

  Further, in the present embodiment, the head holding plate 11 can be rotated in a state where the temperature is within the guaranteed temperature range of the inkjet head 12, so that ink can be normally ejected from the nozzles 31 in the inkjet head 12. The head holding plate 11 can be rotated by an angle corresponding to the temperature.

  Next, modified examples in which various changes are made to the present embodiment will be described. However, description of components having the same configuration as in this embodiment will be omitted as appropriate.

  In the above-described embodiment, the head holding plate 11 can be rotated around its corners, but is not limited thereto. The head holding plate 11 may be rotatable about any part thereof.

  For example, in one modification (Modification 1), as shown in FIG. 6, the head holding plate 61 is in the direction perpendicular to the paper surface of FIG. 6 in the approximate center of the region where the plurality of inkjet heads 12 are arranged. A pivot shaft 62 extending in the vertical direction is rotatably supported. Further, a fixing portion 63 fixed to the printer main body 1 a is provided above the rotating shaft 62, and the rotating shaft 62 is attached to the fixing portion 63.

  Further, the head holding plate 61 has a right end face in the drawing as a guide face 61a similar to the guide face 11a (see FIG. 1), and a left end face in the drawing has a lower end in FIG. The portion is a substantially arcuate guide surface 61b that is curved so as to be on the outer side in the paper width direction in plan view. The guide surfaces 61a and 61b are in contact with the individual guide members 23, respectively.

  In this case, when the head holding plate 61 expands due to a temperature rise and extends in the paper width direction, the spring 24 is attached by the force with which the guide member 23 presses the guide surfaces 61a and 61b, as in the above-described embodiment. It rotates counterclockwise in FIG. 6 as the second direction around the rotation shaft 62 against the force. When the head holding plate 61 that has expanded contracts due to a decrease in temperature and contracts in the paper width direction, the head holding plate 61 is pressed by the spring 24, and the timepiece of FIG. It rotates in the turning direction. Thus, as in the above-described embodiment, when the head holding plate 61 rises in temperature, the displacement of the nozzles 31 in the paper width direction between the inkjet heads 12 can be reduced.

  Here, as in the above-described embodiment, the head holding plate 11 (see FIG. 1) can rotate around the rotation shaft 22a (see FIG. 1) of the hinge 22 attached to the corner thereof. In this case, the nozzle 31 arranged at a position farther from the corner of the head holding plate 11 is far away from the rotation shaft 22a. The nozzle 31 that is far away from the rotation shaft 22a is greatly displaced in the paper feeding direction when the head holding plate 11 is rotated. For this reason, if there is an error between the proper ejection timing and the actual ejection timing after correction, the ink landing position is greatly deviated. As a result, there is a possibility that the ink landing position cannot be accurately corrected.

  On the other hand, in the case of the first modification, the rotation shaft 62 that is the center of rotation of the head holding plate 61 is a substantially central portion of the region where the plurality of inkjet heads 12 of the head holding plate 61 are arranged. Is provided. Therefore, the distance between the nozzle 31 and the rotation shaft 62 of each inkjet head 12 is small, and the deviation of the nozzle 31 in the paper feeding direction when the head holding plate 61 rotates is small. Therefore, the correction amount of the ejection timing is small, and the ink landing position on the recording paper P can be accurately corrected.

  In the first modification, both end surfaces of the head holding plate 61 in the paper width direction are the guide surfaces 61a and 61b. However, only one end surface of the head holding plate 61 in the paper width direction may be the guide surface. .

  In another modification (Modification 2), as shown in FIG. 7, four black heads 72 as low-quality print heads and high-quality prints are provided on a head holding plate 71 as a plurality of inkjet heads. There are four color heads 73 as the heads for use.

  The four black heads 72 are provided with a plurality of nozzles 31 that form a nozzle row 32 by being arranged in the paper width direction, similarly to the inkjet head 12 (see FIG. 1). They are arranged in a line along the paper width direction.

  Each of the four black heads 72 is connected to a black cartridge 75B filled with black ink via a tube 74B, and black ink is supplied from the black cartridge 75B. In the modified example 2, four black heads 72 are individually connected to the black cartridge 75B via the tube 74B. However, in FIG. 7, a tube corresponding to one black head 72 is shown for easy viewing. Only 74B is shown.

  The four color heads 73 include a plurality of nozzles 31 that form three nozzle rows 32 by being arranged along the paper width direction, and the bottom of the four black heads 72 of the head holding plate 71 in FIG. In the side portion, they are arranged in a line along the paper width direction.

  The four color heads 73 are connected to three color cartridges 75Y, 75C, and 75M filled with yellow, cyan, and magenta inks through three tubes 74Y, 74C, and 74M, respectively. The three color inks are supplied from the three color cartridges 75Y, 75C, and 75M. In the modified example 2, the four color heads 73 are individually connected to the color cartridges 75Y, 75C, and 75M via the tubes 74Y, 74C, and 74M. However, in FIG. Only tubes 74Y, 74C, and 74M corresponding to one color head 73 are shown.

  In the printer 1 according to the second modification, black ink as low-quality printing ink is ejected from the plurality of nozzles 31 of the black head 72 onto the recording paper P conveyed in the paper feeding direction by the paper conveyance roller 3. Then, monochrome printing as low image quality printing is performed on the recording paper P. In addition, by ejecting three color inks as high-quality printing ink from the plurality of nozzles 31 of the color head 73 onto the recording paper P conveyed in the paper feeding direction by the paper conveying roller 3, Perform color printing as high-quality printing. More specifically, among a plurality of nozzles 31 of the color head 73, color printing is performed by discharging yellow, cyan, and magenta inks in order from the nozzles 31 that form the upper nozzle row 32 in FIG.

  Further, the head holding plate 71 is rotatably supported by a rotating shaft 76 extending in a vertical direction, which is a direction perpendicular to the paper surface of FIG. 7, in a substantially central portion of an area where the four color heads 73 are arranged. Yes. A fixed portion 77 fixed to the printer main body 1 a is provided above the rotation shaft 76, and the rotation shaft 76 is attached to the fixed portion 77. Further, the end surface of the lower right end portion in FIG. 7 of the head holding plate 71 is a guide surface 71a that contacts the guide member 23 and is similar to the guide surface 11a (see FIG. 1).

  Also in this case, when the head holding plate 71 expands due to a temperature rise and extends in the paper width direction, the head holding plate 71 rotates counterclockwise in FIG. Further, when the expanded head holding plate 61 contracts due to a decrease in temperature and contracts in the paper width direction, the head holding plate 61 is pressed by the spring 24 and rotates in the clockwise direction of FIG. Thus, as in the above-described embodiment, when the head holding plate 61 rises in temperature, the displacement of the nozzles 31 in the paper width direction between the inkjet heads 12 can be reduced.

  Furthermore, in the case of the second modification, the rotation shaft 76 that is the center of rotation of the head holding plate 71 is provided at the substantially central portion of the area where the plurality of color heads 73 of the head holding plate 71 are arranged. ing. Therefore, the distance between the nozzle 31 of each color head 73 and the rotation shaft 76 is small, and the deviation of the color head 73 nozzle 31 in the paper feeding direction when the head holding plate 71 rotates is small. Therefore, the correction amount of the ejection timing at the nozzle 31 of the color head 73 can be small, and the landing position of the color ink on the recording paper P can be accurately corrected at the time of color printing that requires high landing position accuracy. .

  In this case, the distance between the rotation shaft 76 and the nozzle 31 of the black head 72 is increased. For this reason, when the head holding plate 71 rotates, the displacement of the nozzle 31 of the black head 72 in the paper feeding direction becomes large. As a result, the ejection timing correction amount at the nozzle 31 of the black head 72 becomes large. However, since monochrome printing does not require as high landing position accuracy as color printing, the correction amount of the ejection timing is large, and even if there is a slight shift in the landing position, the influence on the image quality is small.

  In the second modification, the example in which the low-quality print head is a black head and the high-quality print head is a color head has been described. However, the combination of the low-quality print head and the high-quality print head is black. It is not limited to a combination of a head and a color head. For example, the low image quality print head may be a black head with a large nozzle interval, and the high image quality print head may be a black head with a small nozzle interval.

  In the above-described embodiment, the guide surface 11a and the guide member 23 convert the extension of the head holding plate 11 in the paper width direction into the rotational force of the head holding plate 11 so that the head holding plate 11 is moved to the second position. However, the extension of the head holding plate 11 in the paper width direction may be converted into the rotational force of the head holding plate 11 by another configuration. In the above-described embodiment, the head holding plate 11 is rotated in the direction opposite to the second direction by the urging force of the spring 24, but the head holding plate 11 is urged by the urging force of the urging mechanism other than the spring 24. You may rotate in the direction opposite to a 2nd direction.

  Furthermore, the converting means for converting the extension of the head holding plate 11 in the paper width direction into the rotational force of the head holding plate 11 in the second direction, or the head holding plate 11 is rotated in the direction opposite to the second direction. The head holding plate 11 is not limited to be rotated by the urging means for urging the head. In another modification (Modification 3), instead of providing the guide surface 11a, the guide member 23, and the spring 24 (see FIG. 1), a gear (not shown) is provided on the rotation shaft 22a of the hinge 22 as shown in FIG. A motor 81 is connected to the head holding plate 11 by driving the motor 81.

  The control device 50 further includes a rotation control unit 82. The rotation control unit 82 controls the rotation angle of the head holding plate 11 by controlling the operation of the motor 81 based on the temperature detected by the temperature sensor 4. In Modification 3, the combination of the motor 81 and the rotation control unit 82 corresponds to the rotation means according to the present invention.

  In this case, when the head holding plate 11 expanded by the temperature rise extends in the paper width direction, the head holding plate 11 rotates by an angle corresponding to the temperature or the ambient environmental temperature. Similar to the embodiment, the displacement of the nozzles 31 in the paper width direction between the inkjet heads 12 can be reduced.

  In the above-described embodiment, the inkjet head 12 is fixed to the head holding plate 11 so that the inkjet head 12 and the head holding plate 11 do not move relative to each other. I can't. In another modification (Modification 4), as shown in FIG. 9A, the left end of the inkjet head 12 in the drawing extends in the vertical direction that is the vertical direction of the paper of FIG. 91 is attached. The rotating shaft 91 is connected to a motor 92 as a holding unit via a gear (not shown), and the inkjet head 12 is rotated about the rotating shaft 91 by driving the motor 92. Can be done. The head holding plate 11 is formed with a through hole 93 continuously extending over the four ink jet heads 12, and the nozzle surface 12 a extends from the through hole 93 even when the ink jet head 12 rotates. It can be exposed downward.

  In this case, when the head holding plate 11 is rotated about the rotation shaft 22a, the motor 92 is driven as shown in FIG. 11 is rotated by the same angle as the head holding plate 11 in the direction opposite to the rotation direction of 11, that is, in the clockwise direction of FIG. At this time, since the rotation angle of the head holding plate 11 is an angle corresponding to the temperature detected by the temperature sensor 4, for example, the rotation angle of the inkjet head 12 is set according to the temperature detected by the temperature sensor 4. By setting the angle, the inkjet head 12 can be rotated in the opposite direction to the head holding plate 11 by the same angle as the head holding plate 11.

  Thereby, the displacement of the nozzle 31 in the paper width direction between the inkjet heads 12 due to the rotation of the head holding plate 11 can be reduced, and in addition, before and after the rotation of the head holding plate 11, the inkjet heads. Since the orientation of 12 is maintained, the interval between the nozzles 31 in the paper width direction can be maintained in each inkjet head 12.

  In the fourth modification, the direction of the inkjet head 12 is held before and after the rotation of the head holding plate 11 by rotating the inkjet head 12 in the direction opposite to the head holding plate 11 by the motor 92. The orientation of the inkjet head 12 may be maintained by other configurations.

  In the above-described embodiment, the four inkjet heads 12 are arranged so that the right side of FIG. 1 is on the upper side in FIG. 1, and the head holding plate 11 extends in the paper width direction due to the temperature rise. 1 was rotated in the counterclockwise direction of FIG. 1, but on the contrary, the four inkjet heads 12 are located on the lower side in FIG. 1 as the right side of FIG. 1. The head holding plate 11 may be rotated in the clockwise direction in FIG. 1 when the head holding plate 11 extends in the paper width direction due to a temperature rise. Even in this case, similarly to the above-described embodiment, it is possible to reduce the displacement of the nozzles 31 between the inkjet heads 12 when the head holding plate 11 extends in the paper width direction due to a temperature rise.

  In the above example, an example in which the present invention is applied to a printer having a so-called line head and the paper width direction and the paper feed direction are orthogonal to each other has been described. However, the present invention is not limited to this.

  Another modification (Modification 5) is an example in which the present invention is applied to a printer equipped with a so-called serial head, and as shown in FIG. 10, along a guide rail 100 in a scanning direction parallel to the paper width direction. A head holding plate 102, two black heads 103, two color heads 104, and the like are provided on a carriage 101 that reciprocates.

  The head holding plate 102 extends long in the paper feeding direction, and is supported at the lower left end in FIG. 10 by a rotary shaft 109 extending in the vertical direction, which is the vertical direction of the paper in FIG. Yes. Further, the end surface on the upper right end side in FIG. 10 of the head holding plate 102 becomes a substantially arc-shaped guide surface 102a in a plan view, which is curved so that the left side portion in FIG. ing. The guide surface 102a is in contact with the outer peripheral surface of the guide member 23 similar to the above-described embodiment. Further, the head holding plate 102 is urged in the paper width direction at the upper left end in FIG. 10 by the same spring 24 as in the above-described embodiment, as indicated by the arrow B. As a result, the head holding plate 102 supported by the rotation shaft 109 is urged clockwise in FIG.

  The two black heads 103 are arranged along the paper feeding direction as the first direction, and a plurality of nozzles 31 are arranged in the paper feeding direction to form a nozzle row 105. . The two color heads 104 are arranged along the paper feeding direction, and the plurality of nozzles 31 are arranged along the paper feeding direction to form three nozzle rows 108. The two black heads 103 are each connected to a black cartridge 107B via a tube 106B, and black ink is supplied from the black cartridge 107B. Then, the black head 103 ejects black ink supplied from the plurality of nozzles 31.

  The two color heads 104 are arranged along the paper feeding direction, and the plurality of nozzles 31 are arranged along the paper feeding direction to form three nozzle rows 108. The two color heads 104 are connected to three color cartridges 107Y, 107C, and 107M filled with yellow, cyan, and magenta inks, respectively, through three tubes 106Y, 106C, and 106M. These three color inks are supplied from the color cartridges 107Y, 107C, and 107M. The color head 104 ejects three color inks supplied from the plurality of nozzles 31. More specifically, yellow, cyan, and magenta inks are ejected from the plurality of nozzles 31 in order from the nozzle array 108 on the left side of FIG.

  In the printer of the fifth modification, any one of the two black heads 103 and the two color heads 104 that reciprocate in the scanning direction together with the carriage 101 on the recording sheet P conveyed in the sheet feeding direction by the sheet conveying roller 3. By ejecting ink from the ink, either monochrome printing or color printing is selectively performed on the recording paper P.

  In this case, when the head holding plate 102 expands due to a temperature rise and extends in the paper feeding direction, the guide surface 102a of the head holding plate 102 is pressed radially inward by the guide member 23, The guide surface 102 a slides with the outer peripheral surface of the guide member 23 by the pressing force. As a result, the head holding plate 102 rotates counterclockwise in FIG. 10 as the second direction around the rotation shaft 109 against the urging force of the spring 24 and is inclined with respect to the paper width direction. It becomes. On the other hand, when the head holding plate 102 that has expanded contracts due to a temperature drop, the head 24 rotates about the rotation shaft 109 in the clockwise direction in FIG. Return to the original posture.

  As a result, when the head holding plate 102 extends in the paper feeding direction due to a temperature rise, the nozzles 31 in the paper feeding direction are respectively between the two black heads 103 and the two color heads 104. Deviation can be reduced.

  Further, by shifting the ejection timing of the ink from the nozzle 31, the ink landing position of the ink ejected from the nozzle 31 shifted in the paper width direction by the rotation of the head holding plate 102 is corrected on the recording paper P. Can do.

  In the fifth modification, the rotation shaft 109 is provided at the corner of the head holding plate 102. However, as in the first and second modifications, the rotation shaft 109 is connected to the two black heads 103 of the head holding plate 102. In addition, it may be provided at a substantially central portion of a region where the two color heads 104 are disposed, a substantially central portion of a region where the two color heads 104 are disposed, or the like.

  In the above-described embodiment, the head holding plate 11 is rotatable at least in a state where the temperature is within the guaranteed operating temperature range of the inkjet head 12, but is not limited thereto. The head holding plate 11 may be rotatable only in a state where the temperature is within a part of the temperature range within the guaranteed operating temperature range. Even in this case, as compared with the case where the head holding plate 11 is not rotated, the deviation of the interval of the nozzles 31 in the paper width direction between the inkjet heads 12 can be reduced.

  In the above example, the rotation axis that is the rotation center of the head holding plate extends in the vertical direction orthogonal to the nozzle surface 12a. However, the rotation axis intersects the nozzle surface 12a and is vertical. You may extend in the direction inclined with respect to the direction.

  In the above-described embodiment, since the plurality of nozzles 31 are arranged in the paper width direction, the recording paper P is conveyed in the paper feeding direction orthogonal to the arrangement direction of the nozzles 31. In Example 5, the plurality of nozzles 31 are arranged in the paper feeding direction and the carriage 101 is moved in the paper width direction perpendicular to the arrangement direction of the nozzles 31, but this is not restrictive. In the above-described embodiment, the plurality of nozzles 31 may be arranged in a direction other than the paper width direction that intersects the paper feeding direction. In the fifth modification, the arrangement direction of the plurality of nozzles 31 and the carriage 101 are arranged. The moving direction may intersect at an angle other than 90 °.

  Further, the example in which the present invention is applied to an ink jet printer that performs printing by discharging ink from nozzles has been described above. However, the present invention is not limited to this, and a liquid discharge device other than an ink jet printer that discharges liquid other than ink. The present invention can also be applied to.

DESCRIPTION OF SYMBOLS 1 Printer 4 Temperature sensor 11 Head holding plate 11a Guide surface 12 Inkjet head 12a Nozzle surface 22a Rotating shaft 23 Guide member 24 Spring 31 Nozzle 32 Nozzle row 51 Correction amount memory | storage part 52 Print control part 61 Head holding plate 61a, 61b Guide surface 62 Rotating shaft 72 Black head 73 Color head 76 Rotating shaft 81 Motor 82 Rotation control unit 92 Motor 102 Head holding plate 103 Black head 104 Color head 109 Rotating shaft

Claims (8)

A plurality of nozzles arranged in a first direction which is a predetermined direction, and a plurality of nozzles arranged along the first direction so that nozzle surfaces on which the plurality of nozzles are formed are on the same surface A liquid ejection head,
The plurality of liquid ejection heads are attached, and an attachment member rotatably supported by a rotation shaft that intersects the nozzle surface;
Rotation means for rotating the attachment member expanded and contracted by temperature change about the rotation axis by an angle corresponding to the expansion and contraction amount in the first direction;
When the attachment member is rotated by the rotation means, the liquid discharged from the plurality of nozzles to the discharge target is related to a direction intersecting the first direction as viewed from the direction orthogonal to the nozzle surface. A liquid ejection apparatus comprising: a landing position correction unit that corrects a landing position.   The liquid ejecting apparatus according to claim 1, wherein the rotation shaft is provided in a central portion of an area of the attachment member where the plurality of liquid ejection heads are attached. The plurality of liquid discharge heads are
A plurality of high-quality printing heads that eject high-quality printing ink from the plurality of nozzles and are arranged along the first direction;
A plurality of low-quality printing heads that eject low-quality printing ink from the plurality of nozzles and are arranged along the first direction; and
The liquid ejecting apparatus according to claim 1, wherein the rotation shaft is provided in a region of the mounting member where the high-quality printing head is disposed. The plurality of low-quality print heads eject black ink as the low-quality print ink from the plurality of nozzles,
The liquid ejecting apparatus according to claim 3, wherein the plurality of high quality printing heads eject color ink as the high quality printing ink from the plurality of nozzles. The rotating means is
Conversion means for converting the extension of the attachment member in the first direction due to a temperature rise into a rotational force in a second direction around the rotation axis of the attachment member;
The liquid ejecting apparatus according to claim 1, further comprising: an urging unit that urges the attachment member in a direction opposite to the second direction. A temperature detecting means for detecting the temperature of the mounting member;
The liquid ejecting apparatus according to claim 1, wherein the rotating unit rotates the attachment member by an angle corresponding to a temperature detected by the temperature detecting unit.   And a holding unit configured to hold the plurality of liquid ejection heads so that the orientation of the plurality of liquid ejection heads does not change before and after the mounting member is rotated by the rotation unit. Item 7. The liquid ejection device according to any one of Items 1 to 6. The plurality of liquid ejection heads are configured to normally eject liquid from the plurality of nozzles in a state where the temperature is within a predetermined guaranteed operating temperature range.
The liquid according to any one of claims 1 to 7, wherein the attachment member can be rotated by the rotation means at least in a state where the temperature is within the guaranteed operating temperature range. Discharge device.

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