JP2007112067A - Liquid droplet discharge apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a liquid droplet discharge apparatus at a low cost which can prevent deterioration in the accuracy of liquid droplet landing positions caused by the deformation of a long member by an environmental temperature change. <P>SOLUTION: The upper face and the lower face of both ends of the long member 168 are fixed to support pieces 180, 182 with face each other and are in face-contact to the support pieces, making the support position of the long member 168 in face-symmetrical relative to the neutral plane H of the long member 168. This enables the displacement amount of the long member 168 in the thickness direction caused by thermal expansion to be made substantially the same, in the longitudinal direction of the long member 168 and a head unit 178. Practically, the bending of the long member 168 caused by an environmental temperature change can be prevented, enhancing the accuracy of the ink droplet landing position for a high quality image, with the improved reliability of an inkjet recording head. Furthermore, the upper face and the lower face of both the ends of the long member 168 are only fixed to a frame body 156 at a low cost. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a droplet discharge device that discharges droplets such as ink.

  In paper width printing by a long head having a paper width, a plurality of head units are arranged side by side in the paper width direction, and driving these head units enables high-speed printing. Here, the head unit is fixed in a longitudinal direction on a long support member (hereinafter referred to as a “long member”) and attached to the main body frame of the inkjet recording apparatus. The head unit, the long member, The support frame is often composed of different materials, and each has a different coefficient of thermal expansion.

  Therefore, when used in a temperature environment different from that at the time of manufacture, or when the temperature in the ink jet recording apparatus is not uniform, the amount of thermal deformation differs depending on the material, thereby causing constriction or bending. Due to such deformation, the ink ejection direction is changed, the landing position is shifted, and the image quality is deteriorated. In addition, a change in the distance between the nozzle surface and the paper (TD = Throw Distance) may cause problems such as the paper contacting the nozzle surface.

  For this reason, in Patent Document 1, the support member (long member) is composed of a plurality of layers made of different materials so as to be substantially the same as the thermal expansion coefficient of the base material of the recording head to avoid bending of the support member. However, this increases the number of manufacturing steps for the support member and increases the cost.

On the other hand, in Patent Document 2, one end portion of a long head is fixed so as to be rotatable, and the other end portion is fixed so as to be movable in a paper feeding direction within a plane parallel to the paper. The fixing position of the recording head can be changed according to the change in the recording head, but the warping of the recording head is not taken into consideration.
Special table 2003-53744 gazette JP 2000-964 A

  In view of the above facts, an object of the present invention is to obtain, at a low cost, a droplet discharge device capable of preventing a drop in accuracy of a droplet landing position due to deformation of a long member due to environmental temperature change.

  According to the first aspect of the present invention, at least one droplet discharge head that discharges droplets from a nozzle, a long member to which the droplet discharge head is attached, both ends of the long member are attached, and a main body And a support frame attached to the frame, wherein the upper and lower surfaces of both ends of the long member are fixed to the support frame.

  When either one of the upper surface side and the lower surface side of the long member has a larger amount of thermal expansion than the other, curved deformation is seen in the long member, but in the invention according to claim 1, the long member By fixing the upper and lower surfaces of both ends of the long member to the support frame, the thermal expansion of the upper and lower surfaces of both ends of the long member is suppressed, and the long member is prevented from being deformed due to environmental temperature changes in the droplet discharge device. Can do.

  Thereby, the droplet landing position accuracy is improved and a high-quality image is obtained. In addition, since the required TD is ensured, the reliability of the droplet discharge head is also improved. Furthermore, since the upper surface and lower surface of both ends of a long member are only fixed to a support frame, it can respond at low cost.

  For example, in a configuration in which droplet discharge heads corresponding to different colors are arranged side by side in the paper feed direction, so-called color misregistration occurs if the amount of misalignment in the paper width direction differs for each ink droplet of each color. In the invention, since the amount of deviation in the paper width direction is small, the color misregistration is also reduced. That is, it is particularly preferable when performing image recording in a plurality of colors such as full color.

  According to a second aspect of the present invention, in the droplet discharge device according to the first aspect, the support frame is plane-symmetric with respect to a neutral surface of the long member.

  In the second aspect of the invention, the support frame is plane-symmetrical with respect to the neutral surface of the long member. For example, when deformation due to a change in environmental temperature of the support frame must be taken into account, the support frame is supported. The curved deformation of the frame can be prevented.

  According to a third aspect of the present invention, at least one droplet discharge head that discharges droplets from a nozzle, a long member to which the droplet discharge head is attached, both ends of the long member are attached, and a main body And a support frame attached to the frame, wherein one end of the elongated member has a lower surface fixed to the support frame, and the other end has an upper surface fixed to the support frame. To do.

  In the invention according to claim 3, one end of the long member fixes the lower surface to the support frame, and the other end fixes the upper surface to the support frame. When used in a higher temperature environment than at the time of manufacture, the upper surface side of the long member thermally expands at one end of the long member, so that the bending direction of the long member is warped upward. On the other hand, at the other end of the long member, the lower surface side of the long member is thermally expanded, so that the bending direction of the long member is bent downward.

  In this way, since the bending direction is opposite between the one end and the other end of the long member, the amount of bending deformation cancels each other, and the bending deformation of the long member due to the environmental temperature change can be reduced.

  According to a fourth aspect of the present invention, at least one droplet discharge head that discharges droplets from a nozzle, a long member to which the droplet discharge head is attached, both ends of the long member are attached, and a main body And a support frame attached to the frame, wherein one end of the elongate member is fixed to the support frame at the upper surface and the lower surface, and the upper or lower surface is fixed to the support frame at the other end. Features.

  In the invention according to claim 4, one end of the long member fixes the upper surface and the lower surface to the support frame, and the other end fixes the upper surface or the lower surface to the support frame. At the other end of the long member, curved deformation occurs. However, at one end of the long member, the upper surface and the lower surface are fixed to the support frame, so that no curved deformation occurs. For this reason, compared with the case where the upper surface or lower surface of the both ends of a long member is fixed to a support frame, the curved deformation of a long member can be reduced.

  According to a fifth aspect of the present invention, in the droplet discharge device according to any one of the first to fourth aspects, a support member is disposed between the elongate member and the support frame, and the support member is interposed therebetween. The elongate member is fixed to the support frame.

  According to the fifth aspect of the present invention, a support member is disposed between the long member and the support frame, and a space corresponding to the length of the support member is secured by fixing the long member to the support frame via the support member. In addition, it is possible to avoid interference between the droplet discharge head attached to the long member and other components disposed in the vicinity of the long member.

  According to a sixth aspect of the present invention, in the droplet discharge device according to the fifth aspect, the support member is plane-symmetric with respect to a neutral plane of the long member.

  In the invention according to claim 6, the support member is made plane-symmetric with respect to the neutral surface of the long member, so that the long member fixed to the support frame via the support member is bent due to a change in environmental temperature. Deformation can be prevented.

  Since the present invention is configured as described above, in the first, third, fourth, and sixth aspects of the invention, the environmental temperature change in the droplet discharge device is suppressed by suppressing the thermal expansion of the upper and lower surfaces at both ends of the long member. Can reduce the bending deformation of the long member, the droplet landing position accuracy is improved, and a high-quality image can be obtained. Also, the reliability of the droplet discharge head is improved. According to the second aspect of the present invention, it is possible to prevent the support frame from being bent due to a change in environmental temperature.

  In the invention according to claim 5, the support member is disposed between the long member and the support frame, and the long member is fixed to the support frame via the support member, thereby fixing the long member. Interference with components disposed in the droplet discharge device can be avoided.

  FIG. 1 shows an ink jet recording apparatus 112 according to an embodiment of the present invention. A paper feed tray 116 is provided in the lower part of the casing 114 of the ink jet recording apparatus 112, and the sheets P stacked in the paper feed tray 116 can be taken out one by one by a pickup roll 118. The taken paper P is transported by a plurality of transport roller pairs 120 constituting a predetermined transport path 122.

  Hereinafter, the “conveying direction” simply refers to the conveying direction of the paper P that is a recording medium, and the “upstream” and “downstream” refer to upstream and downstream in the conveying direction, respectively.

  Above the paper feed tray 116, an endless transport belt 128 stretched between a drive roll 124 and a driven roll 126 is disposed. A recording head array 130 is disposed above the conveyor belt 128 and faces the flat portion 128F of the conveyor belt 128.

  This opposed area is an ejection area SE where ink droplets are ejected from the recording head array 130. The sheet P transported along the transport path 122 is held by the transport belt 128 and reaches the discharge area SE, and ink droplets corresponding to image information are attached from the recording head array 130 while facing the recording head array 130. The

  Then, by rotating the paper P while being held by the transport belt 128, it is possible to perform image recording by so-called multi-pass by allowing the paper P to pass through the ejection region SE a plurality of times. Of course, the sheet P may be passed through the ejection region SE only once, and image recording may be performed in a so-called one pass.

  In this embodiment, the recording head array 130 has a long shape in which the effective recording area is equal to or larger than the width of the paper P (the length in the direction orthogonal to the transport direction), and is a so-called FWA (Full Width Array). Yes. In the recording head array 130, four inkjet recording heads 132 corresponding to four colors of yellow (Y), magenta (M), cyan (C), and black (K) are arranged along the transport direction. Therefore, a full color image can be recorded.

  The method for ejecting ink droplets in each inkjet recording head 132 is not particularly limited, and a known method such as a so-called thermal method or piezoelectric method can be applied.

  Each inkjet recording head 132 is controlled by recording head control means (not shown). The recording head control means, for example, determines the ink droplet ejection timing and the ink ejection port (nozzle) to be used according to the image information, and sends a drive signal to the inkjet recording head 132.

  The recording head array 130 may be stationary in a direction orthogonal to the transport direction. However, if the recording head array 130 is configured to move as necessary, an image with higher resolution can be obtained by multipass image recording. Can be recorded, or troubles of the ink jet recording head 132 can be prevented from being reflected in the recording result.

  On the upstream side of the recording head array 130, a charging roll 136 connected to a power source (not shown) is disposed. The charging roll 136 is driven between the driven roll 126 while sandwiching the conveyance belt 128 and the paper P, and moves between a pressing position for pressing the paper P against the conveyance belt 128 and a separation position separated from the conveyance belt 128. It is possible. At the pressing position, a predetermined potential difference is generated between the driven roll 126 and the ground, so that the sheet P can be charged and electrostatically attracted to the transport belt 128.

  The power source may be a DC power source or an AC power source as long as the paper P can be charged to a predetermined potential.

  Note that a registration roll (not shown) is provided further upstream than the charging roll 136, and the paper P is aligned before reaching between the conveyance belt 128 and the charging roll 136.

  A peeling plate 140 is disposed on the downstream side of the recording head array 130, and the paper P can be peeled from the transport belt 128.

  The peeled paper P is conveyed by a plurality of discharge roller pairs 142 constituting a discharge path 144 on the downstream side of the peeling plate 140, and is discharged to a paper discharge tray 146 provided on the top of the housing 114.

  Below the peeling plate 140, a cleaning roll 148 capable of sandwiching the conveying belt 128 with the driving roll 124 is disposed, and the surface of the conveying belt 128 is cleaned.

  A reversing path 152 composed of a plurality of reversing roller pairs 150 is provided between the paper feed tray 116 and the conveying belt 128, and the sheet P on which an image is recorded on one side is reversed and held on the conveying belt 128. By doing so, it is possible to easily record images on both sides of the paper P.

  Between the transport belt 128 and the paper discharge tray 146, an ink tank 154 is provided for storing each of the four color inks. The ink in the ink tank 154 is supplied to the recording head array 130 through an ink supply pipe (not shown). As the ink, various known inks such as water-based ink, oil-based ink, and solvent-based ink can be used.

As shown in FIG. 2, the ink jet recording head 132 has a rectangular frame (support frame) 156. The frame 156 is arranged so that the direction orthogonal to the transport direction of the paper P is the long side 158 and is disposed so as to face the flat portion 128F of the transport belt 128 shown in FIG. A side plate 160A hangs down from a pair of short sides 160 of the frame body 156 attached to the casing 114, and a pair of upper and lower support pieces 180 and 182 face each other from the inner wall of the side plate 160A. A plurality of sets are extended along the short side 160 and formed integrally with the side plate 160A. A gap is provided between the support piece 180 and the support piece 182, and the long member 168 is slid along the short side 160 direction between the side plate 160 </ b> A and the side plate 160 </ b> A, and the long member 168 is inserted into the gap. The end can be inserted.

  Bolt holes 180A and 182A are formed in the support pieces 180 and 182, respectively. Bolt holes 168A into which the bolts 170 can be screwed are formed at both ends of the long member 168. As shown in FIG. 8B, the bolt 170 is screwed in the order of the bolt hole 180A of the support piece 180, the bolt hole 168A of the long member 168, the bolt hole 182A of the support piece 182, and the nut (not shown). In addition, the upper surface and the lower surface of both ends of the long member 168 are fixed to the support pieces 180 and 182 while being in surface contact with each other. That is, the support position of the long member 168 is symmetrical with respect to the neutral plane including the neutral axis P of the long member 168, or is symmetrical with respect to the neutral axis P of the long member 168. Yes.

  As shown in FIG. 2, the long member 168 is formed with a plurality of head mounting portions 176 along the longitudinal direction, and a head unit 178 is mounted on each of the head mounting portions 176. . Accordingly, each of the head units 178 does not have the paper width of the paper P alone, but by arranging a plurality of head units 178 side by side in the paper width direction, an image recording area larger than the paper width can be obtained. Yes. That is, even if the ink jet recording head 132 does not move along the width direction of the paper P, an image can be formed on the entire surface of the paper P only by the movement of the paper P, so that high productivity can be obtained.

  In the ink jet recording apparatus 112 of the present embodiment configured as described above, the paper P taken out from the paper feed tray 116 shown in FIG. 1 is transported and reaches the transport belt 128 as described above. Then, it is pressed against the conveyance belt 128 by the charging roll 136 and is held by adhering (adhering) to the conveyance belt 128 by the voltage applied from the charging roll 136. In this state, while the paper P passes through the ejection area SE by circulation of the transport belt, ink droplets are ejected from the recording head array 130 and an image is recorded on the paper P.

  When recording an image in only one pass, the paper P is peeled from the transport belt 128 by the peeling plate 140, transported by the discharge roller pair 142, and discharged to the paper discharge tray 146. On the other hand, when performing image recording by multi-pass, after the paper P is circulated and passed through the ejection region SE until the required number of times is reached, the paper P is peeled from the transport belt 128 by the peeling plate 140, The paper is conveyed by the discharge roller pair 142 and discharged to the paper discharge tray 146.

  Next, the operation of the ink jet recording head according to the embodiment of the present invention will be described.

  As shown in FIG. 2, in the inkjet recording head 132 of the present embodiment, the long member 168 and the frame body 156 are each made of a preferable material in consideration of physical properties and cost required for each.

  Specifically, the frame body 156 has a smaller thermal expansion coefficient than the long member 168, and the rigidity of the head unit 178 is sufficiently lower than that of the long member 168. In general, the rigidity of the member to be used can be adjusted depending on the shape, and the rigidity of the member to be used is reduced by providing the member to be used with a thin portion, a hole, or a hollow portion. Moreover, adjustment of rigidity or a thermal expansion coefficient can be aimed at by changing the material of a member to be used.

  When the inkjet recording apparatus 112 is used in a temperature environment different from that at the time of manufacture, the long member 168 is curved and deformed due to the difference in thermal expansion coefficient between the long member 168 and the frame body 156.

  3A and 3B schematically show the deformation state of the long member 168 when the use environment of the ink jet recording head 132 is higher than that at the time of manufacture (note that Here, illustration of the head unit 178 is omitted).

  FIG. 3A shows a case where only the upper surface side of both ends of the long member 168 is fixed by the support piece 180. In this case, since the lower surface side of the long member 168 is in a free state, the amount of thermal expansion increases on the lower side of the long member 168, and the central portion of the long member 168 is bent toward the lower portion. Become.

  FIG. 4 shows the measurement of the displacement of the long member 168 in the Z direction (thickness direction of the long member 168) due to environmental temperature changes in the long member 168 and the head unit 178 in the state of FIG. The results are shown exaggerating the amount of displacement.

  According to this, it can be seen that the amount of displacement in the Z direction at both ends of the long member 168 and the head unit 178 is the smallest due to temperature change, and gradually increases toward the center. This indicates that the long member 168 is curved and deformed in the longitudinal direction of the long member 168.

  FIG. 3B shows a case where only the lower surface side of both end portions of the long member 168 is fixed by the support piece 182. In this case, since the upper surface side of the long member 168 is in a free state, the amount of thermal expansion increases on the upper surface side of the long member 168, and the central portion of the long member 168 is warped upward.

  Thus, when the thermal expansion amount of one of the upper surface side or the lower surface side of the long member 168 is larger than the other, the thermal expansion amount differs in the longitudinal direction of the long member 168, and the long member The member 168 is curved and deformed.

  Here, since the rigidity of the head unit 178 is sufficiently lower than that of the long member 168, the bending deformation of the long member 168 becomes the bending deformation of the head unit 178 as it is. When the head unit 178 is curved and deformed, as shown in FIG. 4, when the ink droplets are landed on the paper P, the arrow indicating the ink droplet ejection direction is inclined obliquely. ), The landing position deviation hardly occurs in the central portion in the paper width direction, but the landing position deviation gradually increases toward both ends.

  As described above, the difference in landing position deviation occurs between the central portion and the end portion of the paper P in the paper width direction, so that the landing pitch gradually increases toward both ends of the long member 168, as shown in FIG. As shown, on the paper P, the dots gradually become rougher toward the end in the width direction.

  Further, in the paper feed direction, as shown by the line --- in FIG. 5 (B), the landing position deviation at the center is large, and the landing position deviation decreases as it goes to both ends, and FIG. ), A curved line is drawn on the paper P.

  From the above, when the long member 168 is curved and deformed, the image quality of the image recorded on the paper P is significantly lowered. Further, in the central portion of the long member 168, the head unit 178 approaches the paper P, and the distance TD between the nozzle surface and the paper P becomes small, which causes inconveniences such as the paper P contacting the nozzle surface. There is also. For this reason, it becomes a subject how the bending deformation of the elongate member 168 can be prevented.

  Therefore, in this embodiment, as shown in FIG. 2 and FIG. 8B, the upper and lower surfaces of both ends of the long member 168 are fixed to the support pieces 180 and 182 in surface contact with each other. The support position of the member 168 is made to be plane symmetric with respect to the neutral plane H including the neutral axis P of the long member 168.

  Here, in this embodiment, the frame body 156 has a smaller thermal expansion coefficient than that of the long member 168 and has a sufficiently large rigidity. Therefore, there is no need to consider deformation of the frame body 156 due to environmental temperature changes.

  Therefore, in FIG. 2 and FIG. 8B, the frame body 156 does not need to be plane-symmetric with respect to the neutral surface H including the neutral axis P of the long member 168, but the frame body due to a change in environmental temperature. When the deformation of 156 must be taken into consideration, the support position of the elongate member 168 including the frame body 156 includes the frame body 156 with respect to the neutral surface H including the neutral axis P of the elongate member 168. Need to be plane-symmetric.

  In this case, for example, as shown in FIG. 9, the side plate 160 </ b> A (see FIG. 2) of the frame body 156 becomes unnecessary, and the support pieces 180 and 182 can be fixed to the upper surface and the lower surface of the frame body 156, respectively. The end of the elongated member 168 is supported between the support member 108 and the support piece 182. Thereby, the support position of the elongate member 168 including the frame body 156 can be made plane-symmetric with respect to the neutral plane H including the neutral axis P of the elongate member 168.

  FIG. 10 shows the amount of displacement of the long member 168 and the head unit 178 in the state of FIG. 8B in the Z direction (thickness direction of the long member 168) due to environmental temperature changes. The measurement results are shown with the displacement amount exaggerated.

  According to this, in the longitudinal direction of the long member 168 and the head unit 178, the displacement amount of the long member 168 in the Z direction due to temperature change is substantially the same. That is, it can be seen that the long member 168 and the head unit 178 hardly undergo any bending deformation.

  Accordingly, as shown in FIG. 7A (FIGS. 7A to 7C show the state of bending deformation of the long member 168 due to environmental temperature changes, and the head unit 178 is not shown. The upper and lower surfaces of both ends of the long member 168 are fixed by the support pieces 180 and 182 to suppress the thermal expansion of the upper and lower surfaces of the both ends of the long member 168, and the length due to environmental temperature changes. The curved deformation of the scale member 168 can be prevented.

  For this reason, as indicated by the □-□ lines in FIGS. 5A and 5B, the ink droplet landing position accuracy is improved, and a high-quality image is obtained. Also, the reliability of the ink jet recording head is improved. Furthermore, since the upper surface and the lower surface of both ends of the long member 168 are only fixed to the frame body 156, it can be handled at low cost.

  Furthermore, in the configuration in which the inkjet recording heads 132 corresponding to different colors are arranged in the paper feed direction, if the amount of misalignment in the paper width direction differs for each color ink droplet, a so-called color shift occurs. In the embodiment, since the amount of deviation in the paper width direction is small, the color misregistration is also reduced. That is, it is particularly preferable when performing image recording in a plurality of colors such as full color.

  Here, both end portions of the long member 168 are supported by the support pieces 180 so as to be symmetrical with respect to the neutral surface H of the long member 168 or line-symmetric with respect to the neutral axis P of the long member 168. , 182, but it is sufficient that at least the upper surface and the lower surface of both ends of the long member 168 can be fixed by the support pieces 180, 182, so the support pieces 180, 182 are not necessarily in the long member 168. There is no need for plane symmetry with respect to the vertical plane H or line symmetry with respect to the neutral axis P of the long member 168.

  In addition, as shown in FIG. 8C, the upper surface of one end of the long member 168 may be fixed with a support piece 180 and the lower surface of the other end may be fixed with a support piece 182. Here, the support position of the long member 168 is point-symmetric with respect to the intersection O between the neutral axis P of the long member 168 and the longitudinal center line of the long member 168. The support position of the long member 168 is not necessarily point-symmetric with respect to the intersection point O.

  In this case, as shown in FIG. 7B, at the one end of the long member 168, the lower surface side of the long member 168 is thermally expanded, so that the bending direction of the long member 168 is bent downward. However, at the other end of the long member 168, since the upper surface side of the long member 168 is thermally expanded, the bending direction of the long member 168 is warped upward.

  Thus, since the bending direction is opposite between the one end and the other end of the long member 168, the deformation amount is canceled out, and as shown by the ◇-◇ lines in FIGS. 5 (A) and 5 (B), The bending deformation of the long member 168 due to environmental temperature change can be reduced.

  Further, as shown in FIG. 7C, the lower surface of one end of the long member 168 is fixed with a support piece 182, and the upper and lower surfaces of the other end are fixed with a support piece 180 and a support piece 182, respectively. The support position of the scale member 168 may be two or more points.

  In this case, bending deformation occurs at one end portion of the long member 168, but bending deformation does not occur at the other end portion of the long member 168 because the upper and lower surfaces are fixed by the support piece 180 and the support piece 182, respectively. Therefore, as shown in FIGS. 3A and 3B, the long member is longer than the case where only the upper surface or the lower surface of both ends of the long member 168 is fixed by the support piece 180 or the support piece 182. The curved deformation of 168 can be reduced.

  Here, the case where the use environment of the ink jet recording head 132 is higher than that at the time of manufacture has been described. However, even if the use environment of the ink jet recording head 132 is lower than that at the time of manufacture, Similar effects can be obtained.

  Incidentally, in order to avoid interference between the frame 156 and other components disposed in the vicinity of the long member 168 in the ink jet recording apparatus 112, as shown in FIG. Support members 184 and 186 may be disposed between 180 and 182, respectively.

  In this case, the support members 184 and 186 are fixed to the upper surface and the lower surface of the long member 168, respectively, and the upper surface of the support member 184 and the lower surface of the support member 186 are fixed to the support pieces 180 and 182, respectively. The supporting position of the elongate member 168 is made symmetrical with respect to the neutral plane H of the long member 168.

  Accordingly, as shown in FIG. 11A, when the support member 184 is disposed between the support piece 180 that fixes the upper surface of the long member 168 (see FIGS. 12A and 12B). Compared with the line reference), as shown by the □-□ lines in FIGS. 12A and 12B, the ink droplet landing position accuracy is improved, and a high-quality image is obtained. In addition, a sufficient TD can be ensured, and the reliability of the inkjet recording head 132 is improved.

  Here, since it is sufficient that at least the upper surface and the lower surface of the long member 168 can be fixed, the support position of the long member 168 is not necessarily symmetrical with respect to the neutral surface H of the long member 168. There is no need.

  Further, as shown in FIG. 11C, a support member 184 is fixed to the upper surface of one end of the long member 168, and the support member 184 is fixed by a support piece 180. Further, the support member 186 is fixed to the lower surface of the other end portion of the long member 168, the support member 186 is fixed by the support piece 182, and the support position of the long member 168 is the central axis P of the long member 168. It may be point symmetric with respect to the intersection O between the longitudinal member 168 and the longitudinal center line of the elongated member 168.

  Thereby, as shown by the ◇-◇ lines in FIGS. 12A and 12B, the support member 184 is disposed between the long member 168 and the support piece 180 at both ends of the long member 168. In comparison, the bending deformation of the long member 168 can be reduced. Of course, the support position of the elongate member 168 is also point-symmetric with respect to the intersection point O, but it is not necessarily required to be point-symmetric with respect to the intersection point O.

  In the above embodiment, the frame body 156 and the support pieces 180 and 182 have the shape shown in FIG. 2 or FIG. 9, but it is sufficient that the upper surface or the lower surface of the end of the long member 168 can be fixed. It is not limited. For example, as shown in FIG. 13, the long member 168 may be supported directly on the frame 156. Further, the support piece 160 may be formed integrally with the frame body 156.

  Further, in the above embodiment, the elongate member 168 is attached to the frame body 156, and the frame body 156 is given as an example of being attached to the housing 114 of the inkjet recording apparatus 112 (see FIG. 1). The body 156 may be omitted, and the elongate member 168 may be directly attached to the housing 114 via the support pieces 180 and 182.

  Further, the head unit 178 may be any unit as long as it can be attached to at least one long member 168, and may be a single unit having a long shape. Of course, as in this embodiment, a plurality of head units 178 are attached to the elongate member 168 so that the overall shape is elongated.

  In each of the above embodiments, the ink jet recording apparatus provided with the ink jet recording head for ejecting ink droplets of each color of black, yellow, magenta, and cyan is exemplified as the liquid droplet ejecting apparatus of the present invention. The head and the droplet discharge device are not limited to those that record images (including characters) on the recording paper P. That is, the recording medium is not limited to paper, and the liquid to be ejected is not limited to ink. For example, ink treatment liquid can be used together, ink can be ejected onto a polymer film or glass to create a color filter for display, or welded solder can be ejected onto a substrate to form bumps for component mounting. In general, a wide range of droplet ejection devices used for industrial purposes are included.

  In these droplet discharge devices, the present invention may be applied not only to the FWA but also to a partial width array (PWA) having a main scanning mechanism and a sub-scanning mechanism. Furthermore, instead of the multipath type, a single path type may be used.

1 is a schematic diagram illustrating an overall configuration of an ink jet recording apparatus according to an embodiment of the present invention. 1 is a perspective view showing a recording head array of an ink jet recording apparatus according to an embodiment of the present invention. (A), (B) is a schematic diagram which shows the deformation | transformation state by the environmental temperature change of the elongate member to which a head unit is attached. It is a perspective view which shows the displacement amount of the Z direction of the elongate member by a thermal expansion in a prior art. The result of having measured the landing position deviation | shift amount according to each support method shown in FIG. 8 is shown, (A) is a paper width direction, (B) is a graph of a paper feed direction. FIG. 5 is a plan view of a sheet showing a landing position by the head unit of FIG. 4, where (A) is a sheet width direction and (B) is a sheet feeding direction. (A)-(C) are the schematic diagrams which show the deformation | transformation state by the environmental temperature change of the elongate member to which the head unit of the inkjet recording device which concerns on embodiment of this invention is attached. (A)-(C) are the schematic diagrams which show the support method of the elongate member to which the head unit which comprises the inkjet recording device of embodiment of this invention is attached. It is a perspective view corresponding to Drawing 2 showing other support methods of a long member. FIG. 6 is a perspective view showing the amount of displacement in the Z direction of the long member due to thermal expansion in the head unit of the ink jet recording apparatus according to the embodiment of the present invention. (A)-(C) are the schematic diagrams which show the other support method of the elongate member to which the head unit of the inkjet recording device which concerns on embodiment of this invention is attached. 11A and 11B show the results of measuring the amount of landing position deviation for each support method shown in FIG. 11, where FIG. 11A is a graph in the paper width direction and FIG. 11B is a graph in the paper feed direction. It is a schematic diagram which shows the other support method of the elongate member to which the head unit which comprises the inkjet recording device of embodiment of this invention is attached.

Explanation of symbols

112 Inkjet recording device (droplet ejection device)
130 Recording Head Array 132 Inkjet Recording Head (Droplet Discharge Head)
156 Frame (support frame)
168 Long member 178 Head unit (Liquid droplet ejection head)
180 Support piece (support frame)
182 Support piece (support frame)
184 Support member 186 Support member

Claims (6)

At least one droplet discharge head for discharging droplets from the nozzle;
A long member to which the droplet discharge head is attached;
Both ends of the elongate member are attached and a support frame attached to the main body frame;
A droplet discharge device comprising:
A droplet discharge device, wherein upper and lower surfaces at both ends of the long member are fixed to the support frame.   The droplet discharge device according to claim 1, wherein the support frame is plane-symmetric with respect to a neutral surface of the long member. At least one droplet discharge head for discharging droplets from the nozzle;
A long member to which the droplet discharge head is attached;
Both ends of the elongate member are attached and a support frame attached to the main body frame;
A droplet discharge device comprising:
One end of the elongate member has a lower surface fixed to the support frame, and the other end has an upper surface fixed to the support frame. At least one droplet discharge head for discharging droplets from the nozzle;
A long member to which the droplet discharge head is attached;
Both ends of the elongate member are attached and a support frame attached to the main body frame;
A droplet discharge device comprising:
One end of the elongated member has an upper surface and a lower surface fixed to the support frame, and the other end has an upper surface or a lower surface fixed to the support frame.   The support member is disposed between the elongate member and the support frame, and the elongate member is fixed to the support frame via the support member. The droplet discharge device according to 1.   6. The droplet discharge device according to claim 5, wherein the support member is plane-symmetric with respect to a neutral surface of the long member.

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