LIQUID EJECTION HEAD ANGLE ADJUSTMENT MECHANISM, LIQUID EJECTION MODULE, AND LIQUID EJECTION APPARATUS

Abstract

To provide a liquid discharge head angle adjustment mechanism that can improve accuracy in adjusting an angle of a liquid discharge head, a liquid discharge module and a liquid discharge device.SOLUTION: A liquid discharge head angle adjustment mechanism comprises a plurality of array members which hold a liquid discharge head and an array support member that supports the array members, where the array support member is provided with a first support member, arranged at one side surface in a direction in which the liquid discharge head turns when adjusting an inclination angle, which supports rotation fulcrums of the array members, a second support member, arranged at the opposite side surface of the one side surface of the first support member and supporting the array members, and a pressing member that presses the rotation fulcrums against the first support member.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a liquid ejection head angle adjustment mechanism, a liquid ejection module, and a liquid ejection apparatus. [Background technology]

[0002] 2. Description of the Related Art A liquid ejection device that ejects liquid onto a medium includes a plurality of liquid ejection heads that eject different types of liquid, such as liquid inks that emit different colors.

[0003] A device is known that arranges multiple liquid ejection heads along the medium transport direction on top of a drum-shaped member that transports the medium, and is equipped with an angle adjustment mechanism that adjusts the angle of each liquid ejection head relative to the drum-shaped member (see, for example, Patent Document 1). Summary of the Invention [Problem to be solved by the invention]

[0004] When a liquid ejection head array is arranged radially along the outer circumference of a drum-shaped member as in the device disclosed in Patent Document 1, the position of the center of gravity of the liquid ejection head array is important in order to precisely adjust the liquid ejection heads so that they face at a predetermined angle. The liquid ejection head array is a long member in a direction parallel to the rotation axis direction of the drum-shaped member. Therefore, to adjust the angle of the liquid ejection head array with respect to the drum-shaped member, it is necessary to adjust it so that the angle is the same throughout the entire long length direction.

[0005] However, the member for controlling the operation of the liquid ejection head is fixed at a position opposite to the fixed position of the liquid ejection head in the longitudinal direction of the long member of the liquid ejection head array. In this case, the center of gravity of the liquid ejection head array is outside the dimension of the rotation axis of the drum-shaped member, that is, outside the support parts provided at the front and rear of the sliding direction of the liquid ejection head. If the center of gravity is biased to one side of the long member, the support parts will no longer function as a fulcrum when adjusting the angle, which reduces the accuracy of the adjustment.

[0006] An object of the present invention is to provide a liquid ejection head angle adjustment mechanism, a liquid ejection module, and a liquid ejection apparatus that can improve the accuracy of angle adjustment of a liquid ejection head. [Means for solving the problem]

[0007] In order to solve the above technical problems, one aspect of the present invention is a liquid ejection head angle adjustment mechanism that individually adjusts the inclination angles of multiple liquid ejection heads, and is characterized in that it has a multiple array members that hold the liquid ejection heads, and an array support member that supports the array members, and is equipped with a first support member that is arranged on one side of the array support member in the direction in which the liquid ejection heads rotate when adjusting the inclination angle and supports the rotation fulcrum of the array member, a second support member that is arranged on the opposite side from the first support member and supports the array member, and a pressing member that presses the rotation fulcrum against the first support member. Effect of the Invention

[0008] According to the present invention, the accuracy of the angle adjustment of the liquid ejection head can be improved. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic diagram showing an overall configuration of a liquid ejection apparatus according to an embodiment of the present invention; [Diagram 2] 1 is a configuration diagram showing an embodiment of a liquid ejection head according to the present invention. [Diagram 3] 1 is a configuration diagram showing an embodiment of a liquid ejection head angle adjustment mechanism according to the present invention. [Figure 4] FIG. [Diagram 5] 1A and 1B are diagrams illustrating a conventional liquid ejection head angle adjustment mechanism. [Figure 6] 1A to 1C are diagrams illustrating problems with a conventional liquid ejection head angle adjustment mechanism. [Figure 7] 5A to 5C are diagrams showing an example of an adjustment operation of the liquid ejection head angle adjustment mechanism according to the present invention. [Figure 8] 3A to 3C are diagrams illustrating a detailed example of an angle adjustment mechanism in the liquid ejection head angle adjustment mechanism. [Figure 9] 10A and 10B are diagrams showing another detailed example of the angle adjustment mechanism in the liquid ejection head angle adjustment mechanism. [Figure 10] 5A to 5C are diagrams for explaining problems with the liquid ejection head angle adjustment mechanism. [Figure 11] 5A to 5C are diagrams for explaining problems with the liquid ejection head angle adjustment mechanism. [Figure 12] 6A and 6B are diagrams for explaining a configuration for solving the problems in the liquid ejection head angle adjustment mechanism. [Figure 13] 6A and 6B are diagrams for explaining a configuration for solving the problems in the liquid ejection head angle adjustment mechanism. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the drawings. First, the configuration of an inkjet printer 1000 will be described as an embodiment of a liquid ejection apparatus according to the present invention.

[0011] [Overall configuration of the inkjet printer 1000] 1 is a diagram showing the overall configuration of an inkjet printer 1000. The inkjet printer 1000 is, for example, an on-demand line-scan type image forming apparatus, and includes an image forming section 210, a paper feed section 220, a registration adjustment section 230, a drying section 240, a recording medium reversing section 250, and a paper discharge section 290. Next, an example of the flow of an image formation output operation (printing operation) in the inkjet printer 1000 having this configuration will be described. The image forming section 210 corresponds to an embodiment of a liquid ejection device.

[0012] First, paper W1 as a recording medium stacked in paper feed stack 221 of paper feed unit 220 is picked up one by one by air separation unit 222 and transported in the direction of image forming unit 210. When paper W1 transported from paper feed unit 220 reaches registration adjustment unit 230, a registration roller pair 231 provided inside registration adjustment unit 230 corrects the inclination of paper W1 with respect to the transport direction.

[0013] The paper W1 that has been corrected (register adjusted) by the registration roller pair 231 is sent to the image forming unit 210. Then, it is sent to the surface of a cylindrical drum 211 by a transport roller pair 214. The drum 211 is provided with a plurality of recording medium grippers 212. The forward end of the sent paper W1 is gripped by one of the recording medium grippers 212, and is transported by the rotation of the drum 211 to a position facing the plurality of head arrays 100 (100K to 100P).

[0014] In the image forming unit 210, a plurality of head arrays 100 that eject liquid ink by an inkjet method, filled with a predetermined ink color, are arranged along the surface in the rotation direction of a cylindrical drum 211. Each head array 100 is arranged at a predetermined radial position in accordance with the curvature of the outer circumferential surface of the drum 211. The angle of each head array 100 is adjusted so that the liquid ejection direction is perpendicular to the surface of the drum 211. In other words, each head array 100 is arranged at a different angle in the radial direction from the rotation axis of the drum 211.

[0015] In other words, the multiple head arrays 100 serving as liquid ejection modules have their respective opposing angles to the drum 211 adjusted so that ink (liquid) is ejected toward the center of rotation of the drum 211 toward the outer peripheral surface of the paper W1 held on the surface of the drum 211.

[0016] In addition, an idle discharge receiver 213 is provided on the outer circumferential surface of the drum 211 to receive idle discharged ink when the head array 100 is not discharging ink onto the paper W1. After an image is formed on the paper W1, the paper W1 is transported to the drying unit 240.

[0017] The drying section 240 is provided with a drying unit 241, and the moisture in the paper W1 evaporates as the paper W1 passes below the drying unit 241. The drying section 240 is also provided with a recording medium inverting section 250 including a recording medium inverting mechanism 251. During double-sided printing, the paper W1 is inverted by the recording medium inverting section 250 and conveyed again toward the image forming section 210 by the inverting conveying section 252. Note that the inclination of the paper W1 is corrected by a registration roller 253 provided inside the image forming section 210 before the paper W1 reaches the drum 211. After drying by the drying section 240, the paper W1 is conveyed to the paper discharge section 290 and is stacked with the edge of the paper W1 aligned.

[0018] Part of the control of the droplet ejection operation in the image forming unit 210 is performed by an image formation control unit 215 provided in the image forming unit 210. The image formation control unit 215 may control the overall operation of the inkjet printer 1000. Also, the paper feed unit 220, the registration adjustment unit 230, and the drying unit 240 may each be provided with an individual control unit, and configured to control the overall operation of the inkjet printer 1000 by cooperating with the image formation control unit 215.

[0019] 1, the transport direction of the paper W1 is the X direction. The rotation direction of the drum 211 that transports the paper W1 when performing the image forming process is the CCW direction (counterclockwise direction) on the XZ plane.

[0020] [Embodiment of Liquid Ejection Head Angle Adjustment Mechanism] Next, an embodiment of the liquid ejection head angle adjustment mechanism according to the present invention will be described. FIG. 2 is an enlarged view of the head array 100. As shown in FIG. 2, the head array 100 includes a plurality of array members 120 for fixing the ejection heads 101 and flanges 110 as array support members for supporting the array members 120. As shown in FIG. 2, the head array 100 supports the plurality of ejection heads 101 at different angles. The inclination angle of each ejection head 101 is adjusted so that it is in a radial direction passing through the rotation axis of the drum 211. That is, the inclination angle of each array member 120 is supported so that the ejection direction is a direction perpendicular to the tangent of the position where the liquid ink ejected from each ejection head 101 lands on the drum 211.

[0021] The head array 100 supports the ejection heads 101 in a state of being sequentially arranged in a direction along the outer peripheral surface at a position facing the outer peripheral surface (the surface along which the paper W1 is gripped and transported) of the drum 211. Therefore, the flanges 110 and the array members 120 are also sequentially arranged in a direction along the outer peripheral surface.

[0022] The ejection heads 101 are configured to eject black (K), cyan (C), magenta (M), and yellow (Y) liquid inks for color printing. Some ejection heads 101 also eject coating liquid (P) for coating the paper W1 to which the special color inks and liquids adhere. In the following explanation, only the ejection heads 101 corresponding to the four colors of liquid inks (K, C, M, Y) will be illustrated.

[0023] The head array 100 includes a flange 110 and an array member 120 as a liquid ejection head angle adjustment mechanism that adjusts the liquid ejection direction of each ejection head 101. The angle adjustment mechanism is configured to support the array member 120 at a predetermined angle by the flange 110. This angle adjustment is performed so that the ejection direction of the ejection head 101 is on a virtual axis perpendicular to the outer circumferential surface of the drum 211 from the center of rotation of the drum 211. In other words, the angle is adjusted so that the axis in the vertical direction of the array member 120 (the virtual radial direction passing through the center of rotation of the drum 211) passes through the center of rotation of the drum 211.

[0024] The flange 110 as an array support member has a front and a rear surface in the rotation direction of the drum 211 (the conveying direction of the paper W1), and on one surface thereof, a V-shaped roller 111 as a first support member, a pressing flat roller 114 as a pressing member, and an adjustment roller 113. The V-shaped roller 111, the adjustment roller 113, and the pressing flat roller 114 are provided on the same surface of the flange 110. On the other surface thereof, a support flat roller 112 as a second support member is provided.

[0025] The V roller 111 supports the V rail 121, which will be described later. The vertical cross-section shape of both the V roller 111 and the V rail 121 in the direction of the rotation axis of the drum 211 is shaped like the letter "V" in Roman letters. Therefore, the V roller 111 has two inclined surfaces facing each other, with the intersection of the inclined surfaces forming the tip. Similarly, the V rail 121 has two inclined surfaces facing each other, with the intersection of the inclined surfaces forming the bottom. The tip of the V roller 111 comes into contact with the bottom part of the V rail 121, thereby functioning as a fulcrum of rotation when adjusting the angle of the array member 120, which will be described later.

[0026] The pressing flat roller 114 as a pressing portion is configured to apply a biasing force to the V roller 111 to press the tip of the V roller 111 against the bottom of the V rail 121. The biasing force of the pressing flat roller 114 can suppress the phenomenon in which the fulcrum of the V rail 121 and the V roller 111 rises up due to the difference in the position of the center of gravity.

[0027] The adjustment rollers 113 function as angle adjustment sections that adjust the inclination angle of the array member 120 by pushing an adjustment flat rail 122 provided on the array member 120 , which will be described later.

[0028] The support flat rollers 112 prevent the array member 120 from rotating due to its own weight around the V rollers 111 as the first fulcrum as the center of rotation, and support the array member 120 so that it is held at a predetermined inclination angle.

[0029] The flange 110 is fixed to a wall surface (for example, a side plate) of a housing that houses a structure including the head array 100. The flange 110 is fixed at a predetermined position at a predetermined interval in the rotation direction (main scanning direction) of the drum 211, as shown in Fig. 2. The array member 120 is suspended from the flange 110 fixed at this predetermined position, so that the array member 120 maintains a predetermined inclination angle with respect to the radial direction of the drum 211.

[0030] The array member 120 serving as the angle-adjustable mechanism is a long member whose longitudinal direction is the rotation axis direction of the drum 211, and whose surface facing the drum 211 has the ejection head 101 fixed thereto. The array member 120 has a front surface and a rear surface in the rotation direction of the drum 211 (the transport direction of the paper W1), and is provided with a V rail 121 and an adjustable flat rail 122 as a first supported portion on one surface. Also, it is provided with a supported flat rail 123 as a second supported portion on the other surface.

[0031] The V rail 121 of the array member 120 is suspended from the V rollers 111 of the flange 110. A supported flat rail 123, which is disposed on the opposite side to the V rail 121, is suspended from the supporting flat rollers 112. An adjustment flat rail 122, which is disposed on the same surface as the V rail 121, is disposed in a position where it is pushed by the adjustment rollers 113.

[0032] The adjustment roller 113 has a structure that allows the amount of protrusion from the side surface of the flange 110 to be variable. When the amount of protrusion of the adjustment roller 113 increases, the amount by which the adjustment roller 113 presses the adjustment flat rail 122 increases. At this time, the position where the tip of the V rail 121 contacts the V roller 111 becomes the rotation fulcrum, and the lower end side of the array member 120 to which the ejection head 101 is fixed rotates in the same direction as the rotation direction of the drum 211. As a result, the position of the ejection head 101 moves in the rotation direction of the drum 211, and the ejection direction of the liquid ink can be adjusted to an angle toward the rotation axis of the drum 211.

[0033] 2, the head array 100 has opposite inclination directions on the upstream side and downstream side in the transport direction, with the boundary being the position of the vertical diameter of the drum 211. For example, the head array arranged on the upstream side in the transport direction is "right inclined," and the head array arranged on the downstream side in the transport direction is "left inclined."

[0034] The right-inclined flange 110 is configured so that the V rail 121 on the lower side of the incline and the adjusting flat rail 122 are received by the V rollers 111 and adjusting rollers 113 provided on the flange 110 arranged on the downstream side in the conveying direction. Also, the supported flat rail 123 on the opposite side is received and stopped by the supporting flat rollers 112 provided on the flange 110 arranged on the upstream side in the conveying direction. Meanwhile, the left-inclined flange 110 is symmetrical to the right-inclined flange 110.

[0035] [Angle adjustment method] Next, a method for adjusting the angle of the ejection head 101 will be described using as an example a method for adjusting the axis of the array member 120. Fig. 3 is a front view showing only a portion of the head array 100. Fig. 4 is a perspective view showing only a portion of the head array 100.

[0036] 3, when one ejection head 101 of the head array 100 is focused on, a V rail 121 and an adjustable flat rail 122 are formed on one of the sides in the transport direction, and only a supported flat rail 123 is arranged on the other side. Note that the ejection array 130 used in the following explanation is inclined to the right.

[0037] When the ejection array 130 is inserted between the flanges 110 and mounted on the liquid ejection module 10, that is, when the ejection array 130 is slid in the Y direction and positioned, its own weight causes its vertical axis to shift with respect to the center of rotation of the drum 211, as illustrated in FIG. 3. If the ejection array 130 is operated in this state, the distance (ejection gap) between the ejection head 101 and the paper W1 being transported by the drum 211 will differ for each ejection head 101. In this case, the position where the liquid ejected from the ejection head 101 adheres to the paper W1 (the landing position) will shift from the intended position. This will adversely affect the quality of the image formed by the liquid ink.

[0038] 3, the end of the array member 120 on the drum 211 side is moved by adjusting the protruding amount of the adjustment roller 113. At this time, the tip of the V rail 121 provided on the array member 120 is in contact with the V roller 111 and functions as a fulcrum of rotation. This rotation allows the tilt angle to be adjusted so that the vertical axis of the array member 120 faces the center of rotation of the drum 211 (drum center 202).

[0039] More specifically, the gap between the side of vibration suppression pin 129 installed on the underside of array member 120 and jig 201 installed on the surface of drum 211 is adjusted to a predetermined value. Note that the predetermined value is, for example, 0.05 mm or less.

[0040] Furthermore, as shown in Figure 4, when the vertical axis of the array member 120 is adjusted to face the drum center 202 of the drum 211, an imaginary line connecting the vibration suppression pins 129 arranged in multiple locations at the front and back (Y-axis direction) of the array member 120 becomes parallel to the rotation axis of the drum 211.

[0041] At this time, the head array 100 is configured so that the gap between each of the vibration suppression pins 129 and the jig 201 is the predetermined value exemplified above.

[0042] [Structure of array member 120] Next, the configuration of the array member 120 will be described in more detail. Fig. 5 is a side view of the array member 120. When facing Fig. 5, the left side is the front side of the head array 100, and the right side is the rear side. Fig. 5 omits the illustration of the entire flange 110, and illustrates only the configuration that functions as a support portion that supports the array member 120.

[0043] 5, the array member 120 is a long member in the width direction of the drum 211 (a direction perpendicular to the transport direction, also called the main scanning direction), and the ejection head 101 is disposed on the underside of one end (front direction) of the array member 120. In addition, a control board 2151 that controls the operation of the ejection head 101, a power supply circuit, etc. are disposed on the upper surface of the end (rear side) opposite the position of the ejection head 101.

[0044] The array member 120 is supported at a predetermined position by the V-shaped rollers 111 and the support flat rollers 112 of the flanges 110 arranged in the width direction of the drum 211. A plurality of the V-shaped rollers 111 and the support flat rollers 112 are arranged at positions in the width direction of the drum 211. The position at which the flanges 110 are arranged is within the range of the dimension of the drum 211 in the width direction.

[0045] Therefore, as illustrated in Figure 5 (a), when the array member 120 is inserted between the flanges 110 so that it is supported by the flanges 110 for operation, the front and central sides of the V-rail 121 are supported by the V-rollers 111.

[0046] 5(b), when the array member 120 is pulled out to the front side of the drum 211, the center and rear sides of the V-rail 121 of the array member 120 are supported by the V-rollers 111.

[0047] In addition, a gap of 1 mm or less is provided between the supporting flat roller 112 and the supported flat rail 123.

[0048] For example, when the state of Fig. 5(b) is shifted to the state of Fig. 5(a), the position of the center of gravity of the array member 120 moves out of between the two V-shaped rollers 111 supporting the V-rail 121 in the longitudinal direction of the array member 120 and moves further back than the rear V-shaped roller 111. Then, as shown in Fig. 6, a rotational moment is generated such that the front end of the array member 120 is lifted and the rear end is lowered.

[0049] In other words, when viewed from the right side of the array member 120 in Fig. 5, a clockwise (CW) rotation moment is generated in the array member 120, causing the array member 120 to tilt in the width direction of the drum 211. As a result, when the adjustment roller 113 presses the side of the array member 120 to adjust the angle, the tip of the V roller 111 does not function as a fulcrum. That is, the accuracy of the angle adjustment of the head array 100 decreases.

[0050] [Structure for preventing the array member 120 from floating up] As explained with reference to Fig. 6, when a rotational moment occurs due to a misalignment of the center of gravity, the function of the first support member formed by the V-shaped rollers 111 arranged at two locations in the longitudinal direction of the array member 120 is reduced. To suppress this, the head array 100 according to this embodiment has a structure in which the pressing flat rollers 114 urge the adjustment flat rails 122 downward, as shown in Fig. 7. The urging structure of the pressing flat rollers 114 will be explained below.

[0051] Fig. 7 is a diagram for explaining the biasing structure of the flange 110. Fig. 7(a) is a right side view showing a part of the head array 100 from the same direction as Fig. 6. As shown in Fig. 7(b), the biasing structure is provided on the left side surface of the flange 110, and therefore will be described below mainly with reference to Fig. 7(b).

[0052] As shown in Fig. 7(b), the pressing flat roller 114 is provided on a swinging arm 1141. The pressing flat roller 114 is rotatable relative to the swinging arm 1141. The swinging arm 1141 rotates about a rotation center 1142 serving as a support shaft fixed to the flange 110. The swinging arm 1141 is biased by an elastic member 1143 in the CCW direction in Fig. 7(b) relative to the flange 110 arranged on the front side of the array member 120.

[0053] The elastic member 1143 is, for example, a tension spring, one end of which is fixed to the end of the swing arm 1141 and the other end of which is fixed to a fixing portion 1144 provided on a part of the flange 110.

[0054] The biasing force of the elastic member 1143 as a biasing member may be set according to the magnitude of the inclination angle of the array member 120 with respect to the radial direction of the drum 211. For example, when multiple array members 120 have different inclinations, an elastic member 1143 that exerts a necessary biasing force on an array member 120 having a larger inclination angle may be used.

[0055] As already explained, when the center of gravity is located at the rear of the array member 120, a rotational moment is generated that causes the front (front side) of the array member 120 to rotate in the CW direction in Fig. 7(a). The force of the elastic member 1143 is in the opposite direction to this rotational moment, so that the pressing flat roller 114 attached to the swing arm 1141 is pressed against the adjustment flat rail 122.

[0056] As a result, the adjustment flat rail 122 is pressed downward, and the V-rail 121 is pressed against the V-roller 111 of the flange 110.

[0057] The above-mentioned action ensures reliable contact between the V rollers 111 and the V rail 121, so that the contact position of the V rail 121 with the V rollers 111 functions as the rotation fulcrum of the array member 120. As a result, when the adjustment rollers 113 are used to push the lower part of the array member 120 sideways, the accuracy of the rotation of the array member 120 can be improved, and the accuracy of the adjustment of the rotation angle of the array member 120 can be improved. This allows the axial center adjustment of the array member 120 to be performed with high precision.

[0058] The position of the center of gravity of array member 120 changes depending on the configuration of control board 2151, power supply circuit, wiring, etc. Therefore, the biasing force can be adjusted to an appropriate value by changing elastic member 1143 in accordance with the movement of the position of the center of gravity, or by changing the position of fixing part 1144, etc.

[0059] The larger the inclination angle of the array member 120, the greater the amount of lift of the V rail 121 relative to the V roller 111. In this regard, it is necessary to increase the urging force (pressing force) of the elastic member 1143. In this regard, if the urging force is set to a value required for an array member 120 with a larger inclination angle, the functional effect of the pressing portion can be obtained for all array members 120, regardless of the inclination angle.

[0060] [Details of Adjustment Roller 113] Next, a detailed structure of the adjustment roller 113 will be described with reference to Fig. 8. Fig. 8(a) is a diagram showing a cross section of the right side surface of the adjustment roller 113. Fig. 8(b) is a horizontal cross-sectional view of the adjustment roller 113.

[0061] 8, the adjustment roller 113 is provided slidably in the front and depth directions in an adjustment roller mechanism groove 1101 formed inside the flange 110. The adjustment roller 113 is configured so that the amount of protrusion from the side surface of the flange 110 toward the adjustment flat rail 122 of the array member 120 changes according to the amount of movement from the front side in the depth direction.

[0062] As shown in Fig. 8(a), the adjustment roller 113 has a moving roller 1131 that is rotatably provided with respect to a roller moving wedge 1132 provided inside the adjustment roller mechanism groove 1101. A wedge pressing screw 1133 is pressed against the wall surface of the roller moving wedge 1132. In addition, a wedge return screw 1134 is screwed into the roller moving wedge 1132.

[0063] As shown in Fig. 8(b), when the wedge pressing screw 1133 is screwed in, the roller moving wedge 1132 is pressed and moves in the depth direction in the groove 1101 for the adjustment roller mechanism. The roller moving wedge 1132 is tapered from the front side toward the depth direction, and the support shaft of the roller moving wedge 1132 contacts the inclined surface. Therefore, when the roller moving wedge 1132 moves in the depth direction, the inclined surface of the roller moving wedge 1132 pushes the support shaft (rotation shaft) of the moving roller 1131 toward the adjustment flat rail 122.

[0064] That is, the amount of protrusion of the movable roller 1131 changes according to the amount of screwing in of the wedge pressing screw 1133. Note that, when reducing the amount of protrusion of the movable roller 1131 to move the movable roller 1131 away from the adjustable flat rail 122, the amount of screwing in of the wedge return screw 1134 may be adjusted.

[0065] As described above, the amount of pressure applied to the adjustable flat rail 122 can be adjusted with precision by the adjustment rollers 113, so that the rotation angle of the array member 120 can be adjusted with precision.

[0066] As a mechanism for adjusting the amount of protrusion of the adjustment roller 113, as shown in FIG. 9, a movable roller 1131a may be provided on an eccentric shaft 1135 provided vertically on the flange 110, and the amount of protrusion of the movable roller 1131 may be adjusted by adjusting the rotation angle of the eccentric shaft 1135.

[0067] [Details of V Coro 111] Next, the features of the V-shaped rollers 111 as an angle adjustment mechanism included in the head array 100 according to this embodiment will be further described.

[0068] As described above, the array member 120 constituting the head array 100 is inserted between the flanges 110 arranged in a state inclined at a predetermined angle with respect to the horizontal plane. Therefore, as illustrated in Fig. 10(a), the array member 120 is inclined at an angle according to the insertion position, and the load is supported while maintaining the inclined state by the V rollers 111 and the support flat rollers 112. At this time, the adjustment rollers 113 are separated from the adjustment flat rails 122 provided on the array member 120.

[0069] Immediately after insertion, the load on the supporting flat rollers 112 of the supported flat rails 123 supported by the supporting flat rollers 112 is a planar component force Fh acting as a component of the array load F due to the weight of the array member 120, as shown in FIG. 10(a).

[0070] Similarly, as shown in FIG. 10(c), a diagonal component force Fv is applied to the V-roller 111 due to the array load F.

[0071] 11(a), a resultant force Fz of the surface direction component force Fh and the slope direction component force Fv acts on the slope of the V roller 111 to the outside of the V roller 111, as indicated by the dashed arrow. This slope component force Fzv acts to slide the V rail 121 outward from the V roller 111, as shown in FIG. 11(b).

[0072] Therefore, it is necessary to regulate the angle of the slope of the V roller 111 so that the V rail 121 does not come off the V roller 111 due to the slope component force Fzv.

[0073] It is necessary to specify the angle of one of the slopes of the V-shaped rollers 111. Therefore, the inclination angle of the array member 120 with respect to the horizontal plane is defined as "θ", and half the slope angle of the V-shaped rollers 111 is defined as "α". In this case, the angle "β" when calculating the slope direction component force Fv of the V-shaped rollers 111 due to the load of the array member 120 is calculated by the following formula (1).

[0074] β = θ + α Equation (1)

[0075] Using formula 1, the V roller slope limit angle "λ", which is the threshold angle at which the V rail 121 does not come off the V roller 111, is calculated by the following formula (2).

[0076] λ=90 degrees - θ (array inclination 33 degrees) - α (V roller angle 75 degrees / 2)...Equation (2)

[0077] According to the above formula (2), the lower limit of the threshold angle is "19.5 degrees."

[0078] If the angle of the tip of V-shaped roller 111 is set to 10 degrees to 15 degrees, the upper limit of the slope angle of V-shaped roller 111 is assumed to be 30 degrees. In this case, when the upper limit of the threshold angle is calculated using the above formula (2), it becomes as shown in the following formula (3).

[0079] λ=90 degrees - θ (array inclination 33 degrees) - α (V roller angle 30 degrees / 2)...Equation (3)

[0080] According to formula (3), the upper limit of the threshold angle is "49.5 degrees," so the upper limit is approximately 50 degrees.

[0081] Therefore, the value of the V roller slope angle "λ", which is the range of angles within which the V rail 121 does not come off the V roller 111, is preferably within the range of 19.5 degrees to 50 degrees.

[0082] As in the head array 100 of this embodiment, if the inclination angle of the slope of the V-shaped roller 111 as the first support member is 19.5 degrees or more with respect to the water surface, the V-rail 121 will not come off the V-shaped roller 111 even if the array member 120 is inclined by 33 degrees or more.

[0083] Furthermore, it is preferable that the angle of the V-roller 111 is wider than the angle formed by the two inclined surfaces of the V-rail 121, so that the tip of the V-rail 121 that enters the groove of the V-roller 111 serves as a fulcrum of rotation, suitable for rocking the array member 120.

[0084] Next, further features of the V roller 111 included in the head array 100 according to this embodiment will be described with reference to Fig. 12. As already explained, the value of the V roller slope angle "λ" should be set in the range of 19.5 degrees to 50 degrees. This "λ" is adjusted and set by the amount of movement of the adjustment roller 113, as already explained.

[0085] To adjust the axis of the array member 120, the adjustment roller 113 is moved in the direction of arrow A as shown in Figure 12(b). This applies a force to the V-rail 121 in the direction of arrow B against the V-rail roller 111. As a result, as shown by arrow C, a force is applied to the V-rail 111 as a rotating member in a direction that moves it away from the rotation axis. In other words, when the axis of the array member 120 is adjusted using the adjustment roller 113, the array member 120 rotates, and a force is applied to the V-rail 121 supported by the V-rail roller 111 in a direction that moves it away from the flange 110.

[0086] After the axis adjustment using the adjustment rollers 113 is completed, the array member 120 is supported by the V rollers 111 and the adjustment rollers 113, and the load of the array member 120 is hardly applied to the supporting flat rollers 112. Therefore, the supporting flat rollers 112 and the supported flat rails 123 are either in contact or separated by a few millimeters.

[0087] In this state, if a force is applied to the V roller 111 in the direction of the rotation axis of the V roller 111, this will cause the rotation of the V roller 111 to be hindered. This will result in what is known as a "stiff rotation." Since a force is applied in the direction pressing the V rail 121 against the V roller 111 in order to adjust the angle of the array member 120, it is desirable to make the rotation of the V roller 111 smooth.

[0088] 12(a), the V-shaped roller 111 according to this embodiment is provided with a retaining flange 1111 at the end of the rotating shaft as a movement restricting member that restricts the movement of the V-shaped roller 111 in the direction of the rotating shaft. Also, to prevent friction with the retaining flange 1111 from impeding smooth rotation, a sliding member 1112 is disposed between the retaining flange 1111 and the side surface of the V-shaped roller 111, the sliding member having a friction coefficient smaller than the friction coefficient between iron.

[0089] A thrust bearing or a sliding bearing can be used for the sliding member 1112. By using the sliding member 1112, it is possible to suppress an increase in frictional resistance caused by an external force (force in the direction of the rotation axis) applied to the V-roller 111 by adjusting the angle of the array member 120.

[0090] As described above, in the discharge array 130 according to this embodiment, a force is applied to the V-shaped roller 111 as the first support member in a direction to pull out from the rotation shaft due to the axial center adjustment of the array member 120, so the V-shaped roller 111 is provided with a retaining flange 1111 and a sliding member 1112. This makes it possible to prevent the V-shaped roller 111 from coming out while suppressing an increase in frictional resistance, making it easier to pull out the array member 120.

[0091] Up to this point, the contact state between the V rail 121 and the V roller 111 has been explained under the assumption that the tip of the V rail 121 makes point contact with the valley portion surrounded by the two slopes of the V roller 111, but the contact state between the V rail 121 and the V roller 111 is not limited to this.

[0092] For example, as shown in Fig. 13, in the vertical cross section of the V-shaped roller 111, the two slopes and the valley portion surrounded by these slopes may be flat. In this case, the shape of the tip of the V-shaped rail 121 may be changed from a pointed state to a rounded curved shape.

[0093] In this case, V rail 121 comes into point contact at two points, the slope and the flat surface of the valley of V roller 111. As a result, even if a force is generated pressing V rail 121 against V roller 111, the load on V roller 111 can be reduced.

[0094] In addition, since the flat portion of the V-shaped roller 111 supports the V-shaped rail 121, it is also possible to position the V-shaped rail 121 in the height direction.

[0095] As described above, the head array 100 according to this embodiment can increase the contact area by making the tip of the V rail 121 that comes into contact with the groove of the V roller 111 rounded. As a result, the load on the bottom surface of the V roller 111 can be reduced.

[0096] In addition, by supporting the V rail 121 on the flat surface of the V roller 111, the position of the V rail 121 in the height direction (arrow D in FIG. 13) can be determined, and the position of the V rail 121 in the height direction can be determined. Furthermore, by supporting it on an inclined surface, the force can be dispersed. As a result, the load on the V roller 111 can be reduced.

[0097] The present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the technical gist of the present invention. The present invention covers all technical matters included in the technical ideas described in the claims. The above-described embodiments are preferred examples, but a person skilled in the art can realize various modifications from the disclosed contents. Such modifications are also included in the technical scope described in the claims. [Explanation of symbols]

[0098] 10: Liquid ejection module 100: Head array 101: Discharge head 110: Flange 111: V Coro 112: Support flat roller 113: Adjustment roller 114: Press flat roller 120: Array member 121: V-rail 122: Adjustable flat rail 123: Supported flat rail 129: Vibration suppression pin 130: Discharge array 201: Jig 202: Drum-centric 210: Image forming section 211: Drums 1000: Inkjet printer 1101: Groove for adjustment roller mechanism 1111: Anti-slip brim 1112: Sliding member 1131, 1131a: moving roller 1132: Roller moving wedge 1133: Wedge press screw 1134: Wedge return screw 1135: Eccentric shaft 1141: Swing arm 1142: Center of rotation 1143: Elastic members 1144:Fixed part 2151: Control board [Prior art documents] [Patent documents]

[0099] [Patent Document 1] JP 2019-142030 A

Claims

1. A liquid ejection head angle adjustment mechanism that individually adjusts the tilt angles of a plurality of liquid ejection heads, A plurality of array members for holding liquid ejection heads; an array support member supporting the array member; The array support member includes: a first support member that is disposed on one side surface in a direction in which the liquid ejection head rotates when the tilt angle is adjusted, and that supports a rotation fulcrum of the array member; A second support member is disposed on the opposite side of the first support member and supports the array member; A pressing member that presses the rotation fulcrum against the first support member; A liquid ejection head angle adjustment mechanism comprising:

2. The pressing member is disposed at an end of the array support member that is far from the center of gravity of the array member in the longitudinal direction of the array member. The liquid ejection head angle adjustment mechanism according to claim 1 .

3. The pressing member includes a biasing member that biases the rotation fulcrum in a direction in which the rotation fulcrum is pressed against the first support member, The biasing force of the biasing member is set according to the magnitude of the inclination angle of each array member. The liquid ejection head angle adjustment mechanism according to claim 1 .

4. The first support member has two inclined surfaces, The angle of the inclined surface on the side that comes into contact when the array member is supported by the first support member is 19.5 degrees or more with respect to the horizontal plane. The liquid ejection head angle adjustment mechanism according to claim 1 .

5. The angle formed by the inclined surface of the first support member is wider than the angle of the rotation fulcrum. The liquid ejection head angle adjustment mechanism according to claim 4 .

6. The tip of the rotation fulcrum is a curved surface. The liquid ejection head angle adjustment mechanism according to claim 1 .

7. the first support member is a rotation member rotatably provided with respect to the array support member, A movement restricting member that restricts movement in a direction of a rotation axis, The coefficient of friction between the rotating member and the movement restricting member is smaller than the coefficient of friction between iron and iron. The liquid ejection head angle adjustment mechanism according to claim 1 .

8. The first support member has two inclined surfaces and a bottom surface between the inclined surfaces, The rotation fulcrum abuts against the first support member at the inclined surface and the bottom surface located on the opposite side of the installation side of the array member that abuts against the first support member, The liquid ejection head angle adjustment mechanism according to claim 1 .

9. A plurality of liquid ejection heads that eject liquid onto a medium; A plurality of array members for holding the liquid ejection heads; a plurality of array support members supporting the array members; A liquid ejection module comprising the liquid ejection head angle adjustment mechanism according to claim 1 .

10. A plurality of liquid ejection heads are disposed on an outer peripheral surface of a drum that transports a medium and eject liquid onto the medium; A plurality of array members for holding the liquid ejection heads; a plurality of array support members supporting the array members; A liquid ejection apparatus comprising the liquid ejection head angle adjustment mechanism according to claim 1 .

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