JP7004243B2 - Liquid discharge unit and device that discharges liquid - Google Patents

Description

The present invention relates to a liquid discharge unit and a device for discharging a liquid.

A liquid discharge unit including a liquid discharge head for discharging liquid, a liquid storage unit for storing liquid, and a liquid level height detecting means for detecting the liquid level in the liquid storage unit is known.

In Patent Document 1, the liquid discharge unit has a plurality of detection electrodes having different lengths, and detects the height of the liquid level in the sub tank, which is a liquid storage unit, based on the output results of the plurality of detection electrodes. Are listed. A plurality of detection electrodes are attached to the upper surface of the sub tank side by side in order of length from one end side. When the liquid level in the sub tank is full, all the detection electrodes come into contact with the liquid in the sub tank, and all the detection electrodes detect the liquid. This makes it possible to detect that the liquid in the sub tank is full. When only the longest detection electrode detects liquid, it can detect that the liquid is in a small amount, and when all the detection electrodes do not detect liquid, it detects that there is no liquid in the sub tank. Can be done.

However, when the liquid discharge unit described in Patent Document 1 is used in a device for discharging liquids in which a plurality of liquid discharge units are arranged at different inclination angles, there is a possibility that the cost of the device may be increased.

In order to solve the above problems, the present invention comprises a liquid discharge head for discharging a liquid, a liquid storage unit for storing the liquid, and a liquid level height detecting means for detecting the liquid level height in the liquid storage unit. The liquid discharge unit including the liquid storage unit includes a posture adjusting means for adjusting the posture of the liquid storage unit with respect to a mounting member to which the liquid storage unit is attached , and the posture adjusting means includes a holding member for holding the liquid storage unit. A fulcrum portion provided on the mounting member that rotatably supports the holding member, and a mounting member that extends along the rotation trajectory of the holding member and allows the fastening member to fasten the liquid storage portion to slide and move. It is characterized by having a fixing groove portion provided in the above.

According to the present invention, the cost of the device can be reduced.

The schematic block diagram which shows an example of the image forming apparatus system which concerns on this embodiment. (A) is a top view showing an example of a line engine type liquid discharge unit. (B) is a front view showing a schematic configuration of a line engine type liquid discharge unit and a cylindrical drum. The figure which shows an example of the ink supply system of a liquid ejection unit 2. The schematic which shows the sub tank 64. It is a figure which shows the example which formed the sub-tank 64 so that the liquid level detection sensor 71 is parallel in the vertical direction. The figure explaining the attitude adjustment of the sub tank 64. The figure which shows the sub tank 64 attached in the upright posture by the holding member 90, and the liquid discharge unit arranged in an inclined posture. The figure which shows the modification of the posture adjustment of a sub tank 64.

Hereinafter, embodiments of the present invention are applied to an image forming apparatus system including a printer for ejecting ink, which is a liquid for image forming, to form an image by an inkjet method, which is an image forming apparatus as an image forming apparatus for ejecting a liquid. explain.

FIG. 1 is a schematic configuration diagram showing an example of an image forming apparatus system according to the present embodiment.
The image forming apparatus system according to the present embodiment has a liquid ejection unit 2 provided with a liquid ejection head for ejecting ink by an inkjet method, and a cylindrical drum using a method of holding and transporting paper as a recording medium on the surface. It is provided with an image forming unit 1 having the three. Further, the image forming apparatus system includes a feeding unit 10 for feeding the loaded paper and a resist adjusting unit 20 for correcting the resist of the paper on the upstream side of the image forming unit 1 in the paper transport direction. Further, the image forming apparatus system includes a drying unit 30 for drying the paper on which the image is formed by an inkjet method and a paper discharging unit 40 for discharging the dried paper on the downstream side of the image forming unit 1 in the paper transport direction. A paper reversing transport unit 50 for further forming an image is provided on the back surface of the paper.

Next, a series of image forming operations for forming an image on paper in the image forming apparatus system according to the present embodiment will be described.
In FIG. 1, first, the paper 11 loaded on the paper feed unit 10 is separated and picked up one by one by the air separation unit 12 using air. The paper 11 picked up by the air separation unit 12 is conveyed to the resist adjusting unit 20 on the downstream side in the transfer direction toward the image forming unit 1.

The paper 11 conveyed from the paper feed unit 10 reaches the resist adjusting unit 20. Then, in the resist adjusting unit 20, the resist correction of the paper 11 is performed by the resist roller 21 provided inside. The resist-corrected paper 11 by the resist adjusting unit 20 is conveyed to the image forming unit 1 at a predetermined timing.

The paper 11 that has been resist-corrected and conveyed to the image forming unit 1 is positioned on the surface of the cylindrical drum 3 with its tip sandwiched by the paper gripper 4 provided on the surface of the cylindrical drum 3. Further, the cylindrical drum 3 is formed with innumerable air suction holes on the front surface thereof, and the entire paper 11 can be sucked by air from the back surface and held in close contact with the front surface of the cylindrical drum 3. Then, the paper 11 positioned on the surface of the cylindrical drum 3 by the paper gripper 4 and held in close contact with air suction is conveyed in the direction of the liquid discharge unit 2 by rotating the cylindrical drum 3 in the direction of the arrow in the drawing. Will be done.

The liquid ejection unit 2 is sequentially arranged in the image forming portion 1 along the surface of the circumference of the cylindrical drum 3 in a state of being filled with a predetermined ink color. Paper 11 held on the surface of the cylindrical drum 3 is conveyed to the lower portion of the liquid ejection unit 2 of each color, and ink of each color is printed from the nozzle of the liquid ejection head of the liquid ejection unit 2 at a predetermined timing. As a result, an image is formed on the surface of the paper 11.

The cylindrical drum 3 is provided with paper grippers 4 that hold the tip of the paper 11 at three locations on the surface of the circumference. As a result, the image can be formed on the three sheets of paper 11 while the cylindrical drum 3 makes one rotation.

The paper 11 on which the image is formed by the image forming unit 1 is conveyed to the drying unit 30. The drying unit 30 is provided with a drying unit 31, and the paper 11 passes under the drying unit 31 to evaporate the moisture in the ink and prevent the paper 11 from curling.

The paper 11 that has passed through the drying unit 30 is conveyed to the paper ejection unit 40, and is loaded on the paper ejection unit 40 in an orderly aligned state.

Further, the drying unit 30 is provided with a paper reversing unit 51 and a paper reversing transport unit 50, and at the time of double-sided printing, the paper 11 is inverted here and transported to the image forming unit 1 again. After the paper reversing unit 51 switches the transport direction of the paper 11, the paper reversing transport unit 50 transports the paper 11 in the direction of the image forming unit 1. Before the paper 11 reaches the cylindrical drum 3, the resist roller 52 corrects the resist. The resist-corrected paper 11 is conveyed to the cylindrical drum 3, sandwiched between the paper grippers 4, and held on the front surface of the cylindrical drum 3 with the back surface on which the image is not formed facing up. Then, in the image forming unit 1, the liquid discharging head of the liquid discharging unit 2 forms an image on the back surface where the image of the paper 11 held on the front surface of the cylindrical drum 3 is not formed in the same manner as described above. ..

The double-sided printed paper 11 that has passed through the drying unit 30 is conveyed to the paper ejection unit 40 in the same manner as in single-sided printing, and is loaded on the paper ejection unit 40 in an orderly aligned state.

Further, as shown in FIG. 2A, the liquid discharge unit 2 according to the present embodiment is a line engine type in which a plurality of liquid discharge heads 60 are arranged in the main scanning direction of the cylindrical drum 3. In the line engine type, a plurality of liquid discharge heads 60 are arranged in a staggered manner in the longitudinal direction, which is the main scanning direction, and are provided side by side in the depth direction of the cylindrical drum 3 shown in FIG. 2 (b).

FIG. 3 is a diagram showing an example of an ink supply system of the liquid ejection unit 2.
As shown in FIG. 3, in the liquid discharge unit 2, the liquid ink I is supplied from the main tank 65 by the feed pump 66, and the sub tank 64, which is a liquid storage unit for storing the ink I, and a plurality of liquid discharge heads 60 are supplied. It has a manifold 63, a plurality of head tanks 61 provided corresponding to the liquid discharge head 60, and the like. A solenoid valve 62 for opening and closing the flow path is provided in the flow path between the manifold 63 and each head tank 61.

The sub-tank 64 is provided with a liquid level detection sensor 71, which is a liquid level height detecting means, and an atmospheric release valve 72 that opens the inside to the atmosphere. The liquid level height is the length in the vertical direction from the bottom surface of the sub tank 64 to the liquid level. The liquid level detection sensor 71 uses a float sensor, a method of detecting the presence or absence of ink based on the number of electrode pins that have detected ink, a liquid level detection method using a laser, and others. Method can be used.

When the liquid level detection sensor 71 detects the ink shortage in the sub tank, ink is supplied from the main tank 65 to the sub tank 64 by the signal from the control unit 80 using the feed pump 66. Then, when the liquid level detection sensor 71 detects that the tank is full, the feeding pump 66 is stopped to stop the ink supply to the sub tank 64.

Further, the operation of discharging the bubbles accumulated in the ink supply path from the main tank 65 to the sub tank 64 is performed at a predetermined timing. Specifically, the air release valve is opened, and ink is supplied to the sub tank 64 by the feed pump 66 until the liquid level detection sensor 71 detects that the liquid level has reached a predetermined position. As a result, air bubbles accumulated in the ink supply path can be discharged through the atmospheric release valve of the sub tank 64.

The sub tank 64 has the following roles.
1. 1. The role of temporarily storing ink and using it as a buffer when ink is consumed by the ejection operation of the liquid ejection head 60.
2. 2. The role of opening the atmospheric release valve 72 and discharging the air bubbles accumulated in the ink supply path at an appropriate timing.
3. 3. The role of reducing the pulsation generated by the pump driven during ink supply.
4. The role of forming the pressure between the liquid discharge head 60 and the liquid discharge head 60.

In order for the sub-tank 64 to function well as described above, it is preferable to arrange the sub-tank 64 as close to the liquid discharge head 60 as possible.

FIG. 4 is a schematic view showing the sub tank 64.
In the present embodiment, since each liquid discharge unit 2 is arranged along the surface of the cylindrical drum 3, each liquid discharge unit 2 is arranged so as to be inclined with respect to the vertical direction. Further, the tilt angle of the liquid discharge unit arranged near the top of the cylindrical drum 3 with respect to the vertical direction and the tilt angle of the liquid discharge unit 2 away from the vicinity of the top of the cylindrical drum 3 with respect to the vertical direction are different.
The amount of ink in the sub tank of each liquid ejection unit is the same.

Since the liquid discharge unit 2 is arranged so as to be inclined in this way, the sub tank 64 is also inclined. Since the sub tank 64 is tilted in this way, the liquid level of the ink I of the sub tank 64 is not parallel to the bottom surface of the sub tank 64, and the liquid level height differs in the horizontal direction. As a result, the liquid level detection sensor 71 cannot accurately detect the liquid level. For example, when a float sensor is used as the liquid level detection sensor 71, the float does not receive buoyancy on the entire surface, so that the position is not stable and high-precision detection cannot be performed.

Further, as shown in FIG. 4, although the amount of ink in the sub tank of each liquid ejection unit is the same, the detection result of the liquid level detection sensor 71 is different in each liquid ejection unit. Specifically, the liquid level height detected by the liquid level detection sensor of the liquid discharge unit on the right side in the figure having a large inclination angle is higher than the liquid level height detected by the liquid level detection sensor of the liquid discharge unit on the left side in the figure. It will be detected high. As a result, in the liquid ejection unit on the right side of the figure where the inclination angle is large, although the amount of ink in the sub tank is small, the detection result based on the liquid level height detected by the liquid level detection sensor is sufficient for ink. If a large amount of ink is ejected by the liquid ejection head in the liquid ejection unit on the right side of the figure, the ink may not be supplied to the liquid ejection head in time and the ink in the liquid ejection head may run short. There is.

Further, if the sub tank 64 is also tilted, the liquid feeding accuracy may be lowered. Specifically, for example, if there is an inlet for ink to flow in on the lower side in the inclined direction and an outlet for ink to flow out on the upper side in the inclined direction, the ink may flow back and the liquid feeding accuracy is lowered. There is a risk.

FIG. 5 is a diagram showing an example in which the sub tank 64 is formed so that the liquid level detection sensor 71 is parallel to the vertical direction. In the example shown in FIG. 5, the amount of ink in the sub tank of each liquid ejection unit is the same.
As shown in FIG. 5, by configuring the sub tank 64, the liquid level detection sensor 71 can satisfactorily detect the liquid level height in the sub tank 64. Further, even if the inclination angles of the liquid ejection units are different from each other, the relationship between the amount of ink in the sub tank and the detection result of the liquid level detection sensor 71 can be the same, and the sub tank can be accurately related to each liquid ejection unit. The amount of ink inside can be detected.

However, in the present embodiment, since the tilt angles of the liquid discharge units 2 with respect to the vertical direction are different from each other, it is necessary to prepare different sub tanks 64 according to the tilt angles, which increases the management cost of parts and increases the cost. Connect. Further, the problem that the liquid feeding accuracy is lowered cannot be solved. Further, depending on the inclination angle, the sub tank 64 is greatly bent, which takes a lot of space and may lead to an increase in the size of the device.

Therefore, in the present embodiment, a posture adjusting means for adjusting the posture of the sub tank 64 is provided.

FIG. 6 is a diagram illustrating the posture adjusting means of the sub tank 64.
As shown in FIG. 6, the posture adjusting means has a frame-shaped holding member 90 for holding the sub tank 64, and a mounting base member 93 as a mounting member to which the holding member 90 is mounted. The four corners of the holding member 90 are provided with screw through holes 92a, 92b, 92c, 92d through which a screw as a fastening member penetrates. The sub tank 64 is installed in the frame of the holding member 90 and fixed to the holding member 90.

The mounting base member 93, which is a mounting member to which the sub tank 64 of the liquid discharge unit 2 is mounted, is formed with a screw hole to which the holding member 90 is screwed. The mounting base member 93 is provided with one screw hole 104 having a screw groove formed on the inner peripheral surface to which a screw penetrating the first screw through hole 92a, which is a fulcrum of rotation of the holding member 90, is fixed. The screw hole through which the screw penetrating the second screw through hole 92b is stopped is on the movement locus of the second screw through hole 92b when the holding member 90 is rotated with the screw penetrating the first screw through hole 92a as a fulcrum. It is provided at three locations (101a, 101b, 101c in the figure). Similarly, three screw holes 102a, 102b, 102c for fixing the screw penetrating the third screw through hole 92c are provided on the movement locus of the third screw through hole 92c and penetrate the fourth screw through hole 92d. Three screw holes 103a, 103b, 103c for fixing the screw to be screwed are provided on the movement locus of the fourth screw through hole 92d.

As shown in FIG. 6, the holding member 90 of the liquid discharge unit 2 on the left side in the drawing, which is arranged without being tilted, is screwed into the screw holes 101a, 102a, 103a and 104 of the mounting base member 93. As a result, the sub tank 64 held by the holding member 90 is attached to the liquid discharge unit 2 without tilting.

Further, of the three liquid discharge units 2 in the figure, the holding member 90 of the liquid discharge unit 2 having a small inclination angle in the middle is screwed into the screw holes 101b, 102b, 103b and 104 of the mounting base member 93. As a result, the sub tank 64 held by the holding member 90 is attached to the liquid discharge unit 2 in an upright posture.

The holding member 90 of the liquid discharge unit 2 having the largest inclination angle on the right side in the figure is screwed into the screw holes 101c, 102c, 103c and 104 of the mounting base member 93. The sub tank 64 held by the holding member 90 is attached to the liquid discharge unit 2 without tilting.

In this way, the sub tank 64 can be mounted in an upright posture for each of the plurality of liquid discharge units 2 having different inclination angles, and the printer, which is a device for discharging liquid, is mounted on the mounting surface. Both can be in the same posture.

FIG. 7 is a diagram showing a sub tank 64 attached in an upright posture by a holding member 90 and a liquid discharge unit arranged in an inclined posture.
As shown in FIG. 7, even if the liquid discharge unit is arranged in an inclined posture, since the sub tank 64 is mounted in an upright posture, the liquid level can be set to the same height in the horizontal direction, and the liquid level can be set to the same level. The detection sensor 71 can satisfactorily detect the liquid level in the sub tank 64. Further, the relationship between the liquid level height and the amount of ink in the sub tank can be made the same in each liquid ejection unit without preparing different sub tanks 64 or the like according to the inclination angle, and the liquid is discharged in all the liquid ejection units. Based on the detection result of the surface detection sensor 71, the amount of ink in the sub tank can be accurately detected. As a result, it is possible to suppress the occurrence of ink shortage in the sub tank, suppress the management cost of parts, and reduce the cost. In addition, it is possible to suppress a decrease in liquid feeding accuracy.

FIG. 8 is a diagram showing a modified example of the posture adjusting means.
In this modification, the mounting base member 193 has a first groove portion 193a extending along the movement locus of the second screw through hole 92b when the holding member 90 is rotated, and a movement locus of the third screw through hole 92c. It has a second groove portion 193b extending along the same, and a third groove portion 193c extending along the movement locus of the fourth screw through hole 92d.
Bolts are passed through the second screw through hole 92b and the first groove portion 193a, the third screw through hole 92c and the second groove portion 193b, and the fourth screw through hole 92d and the third groove portion 193c, respectively, to form the mounting base member 93. A nut is screwed into the bolt from the surface opposite to the surface on which the holding member 90 is mounted, and the holding member 90 on which the sub tank 64 is held is fastened to the mounting base member 93.

To adjust the posture of the sub tank 64, first, the tightening of the holding member 90 with respect to the mounting base member 93 is weakened, and the holding member 90 is made rotatable with the first screw through hole 92a as a fulcrum. Next, the holding member 90 is rotated. Then, the bolts penetrating the groove portions 193a, 193b, and 193c move in the grooves, and the posture of the sub tank 64 held by the holding member 90 is adjusted. Then, when the sub tank 64 is in the upright posture, the bolts are tightened to attach the holding member 90 to the attachment base member 93.

The sub tank 64 may be attached to the holding member 90 after adjusting the posture of the holding member 90 and fastening the holding member 90 to the attachment base member 93 so that the holding member 90 has a straight posture.

In the modified example shown in FIG. 8, even if the liquid discharge unit is arranged in an inclined posture, the sub tank 64 can be mounted in an upright posture so that the liquid level height can be the same in the horizontal direction. As a result, the liquid level detection sensor 71 can satisfactorily detect the liquid level in the sub tank 64. Further, each liquid ejection unit can accurately detect the amount of ink in the sub tank without preparing different sub tanks 64 or the like according to the inclination angle. As a result, the management cost of parts can be suppressed, and the cost can be reduced. In addition, it is possible to suppress a decrease in liquid feeding accuracy.

Further, according to this modification, the posture of the sub tank 64 can be adjusted without removing the bolt which is the fastening member, and there is no problem that the fastening member is lost during the posture adjustment of the sub tank 64.

Further, in the above modification, the groove portions 193a, 193b, and 193c have a through-hole shape through which the bolt penetrates, and the bolt as a fastening member can be slidably moved, but the present invention is not limited to this. For example, each groove portion 193a, 193b, 193c may have a non-through hole shape in which a nut as a fastening member is held so as to be slidable. Specific examples of the groove in which the nut is held so that it can be slidably moved are the first groove whose groove width is slightly wider than the outer diameter of the nut and the groove width which is wider than the diameter of the screw hole of the nut and is outside the nut. Examples thereof include those having a second groove narrower than the diameter and provided so as to block a part of the first groove.

Further, in the above description, the sub tank 64 is attached to the mounting base member 93 via the holding member 90, but the sub tank 64 may be directly attached to the mounting base member 93. Specifically, the parts constituting the sub tank 64 are provided with screw through holes through which screws and bolts pass, and the posture is formed by attaching the screws and bolts to the mounting base member 93 shown in FIGS. 7 and 8 above. The sub-tank 64 can be directly mounted to the mounting base member 93 in an adjustable manner.

Further, although the sub tank 64 is attached to the attachment base member 93 in the above description, the sub tank 64 may be attached to the liquid discharge head. In the case of a configuration in which the sub tank 64 is attached to the liquid discharge head, the posture of the sub tank 64 can be adjusted by providing the screw holes and grooves described with reference to FIGS. 7 and 8 above in the parts constituting the liquid discharge head. can do. In such a configuration, the liquid discharge head also functions as a mounting member.

The "adjustment" of the posture adjustment has almost the same meaning as the words such as setting, changing, adjusting, etc., and does not strictly define the meaning. Further, the "posture" is, for example, an angle with respect to the mounting base member 93, which is the mounting member of the sub tank 64, which is the liquid storage unit.

The "device for discharging the liquid" is not limited to the inkjet recording device, and may be any device provided with a liquid discharge unit and driving the liquid discharge head to discharge the liquid. The "device for discharging a liquid" includes not only a device capable of discharging a liquid to a device to which the liquid can adhere, but also a device for discharging the liquid into the air or into the liquid.

The "device for discharging the liquid" may include means for feeding, transporting, and discharging paper to which the liquid can adhere, as well as a pretreatment device, a posttreatment device, and the like. For example, as a "device for ejecting a liquid", an image forming device such as an inkjet recording device for ejecting ink to form an image on paper, and a powder for modeling a three-dimensional model (three-dimensional model). Examples thereof include a three-dimensional modeling device (three-dimensional modeling device) that discharges a modeling liquid into a powder layer formed in layers.
In addition, as a "device for ejecting liquid", a treatment liquid coating device for ejecting a treatment liquid to the paper in order to apply the treatment liquid to the surface of the paper for the purpose of modifying the surface of the paper, raw materials. There is also an injection granulation device that granulates fine particles of raw materials by injecting a composition liquid in which the above-mentioned material is dispersed in a solution through a nozzle.

Further, as the "device for discharging the liquid", a device for relatively moving the liquid discharge head and the device to which the liquid can adhere can be mentioned. Specific examples include a serial type device that moves the liquid discharge head, a line type device that does not move the liquid discharge head, and the like. Further, the "device for discharging a liquid" is not limited to a device in which the liquid discharge head and the device to which the liquid can adhere move relatively.

Further, the "device for discharging a liquid" is not limited to a device in which a significant image such as characters and figures is visualized by the discharged liquid. For example, those that form patterns that have no meaning in themselves and those that form a three-dimensional image are also included.

The above-mentioned "thing to which a liquid can adhere" means a material to which a liquid can adhere at least temporarily, such as a material to which the liquid adheres and adheres, and a material to which the liquid adheres and permeates. Specific examples include paper, recording paper, recording paper, film, cloth and other recording media, electronic substrates, piezoelectric elements and other electronic components, powder layers (powder layers), organ models, inspection cells and other liquid objects. It is a discharge medium and includes all substances to which a liquid adheres, unless otherwise specified.

The material of the above-mentioned "material to which a liquid can adhere" may be paper, thread, fiber, cloth, leather, metal, plastic, glass, wood, ceramics or the like as long as the liquid can adhere even temporarily.

The "liquid" may have a viscosity and surface tension that can be discharged from the head, and is not particularly limited, but has a viscosity of 30 mPa · s or less at room temperature, under normal pressure, or by heating or cooling. It is preferable to have. More specifically, solvents such as water and organic solvents, colorants such as dyes and pigments, polymerizable compounds, resins, functionalizing materials such as surfactants, biocompatible materials such as DNA, amino acids and proteins, and calcium. , Solvents, suspensions, emulsions, etc. containing edible materials such as natural pigments, such as inks for inkjets, surface treatment liquids, components of electronic and light emitting elements, and formation of electronic circuit resist patterns. It can be used in applications such as liquids and material liquids for three-dimensional modeling.

Further, the "liquid discharge head" is a functional component that discharges and ejects liquid from a nozzle. Piezoelectric actuators (laminated piezoelectric elements and thin-film piezoelectric elements), thermal actuators that use electric heat conversion elements such as heat-generating resistors, and electrostatic actuators that consist of a vibrating plate and counter electrodes are used as energy sources for discharging liquid. Includes what to do.

Further, in the terms of the present application, image formation, recording, printing, printing, printing, modeling, etc. are all synonymous.

The above description is an example, and the effect peculiar to each of the following aspects is exhibited.
(Aspect 1)
The liquid level height of a liquid discharge head 60 that discharges a liquid such as ink I, a liquid storage unit such as a sub tank 64 that stores the liquid, and a liquid level detection sensor 71 that detects the liquid level height in the liquid storage unit. In the liquid discharge unit provided with the detection means, the liquid discharge unit has a posture adjusting means such as an attitude adjusting mechanism for adjusting the posture of the liquid storage unit with respect to the mounting member such as the mounting base member 193 to which the liquid storage unit is mounted.
When the liquid discharge unit 2 is tilted and arranged on the device that discharges the liquid, the liquid level of the liquid in the liquid storage portion such as the sub tank 64 is tilted with respect to the liquid storage portion. When a plurality of liquid discharge units 2 are arranged in a device that discharges liquids at different inclination angles, the inclination angles of the liquid level in the liquid storage unit with respect to the liquid storage unit are different from each other in the plurality of liquid discharge units. As a result, when the liquid discharge unit described in Patent Document 1 is used as each liquid discharge unit, even if the amount of liquid in the liquid storage unit is the same, the detection results of the liquid level height detecting means are mutual. It will be different. Therefore, in order to obtain the same result for each liquid discharge unit as the detection result of the liquid level height detecting means, the length of the detection electrode is changed for each liquid discharge unit, and the configuration is set for each liquid discharge unit. It will be necessary to make it different. As a result, the parts management cost increases, which may lead to an increase in the cost of the device.
On the other hand, in the first aspect, since the posture adjusting means is provided, even if the plurality of liquid discharging units are arranged in the devices for discharging the liquid at different inclination angles, the posture adjusting means causes the liquid storage unit to have the liquid storage unit. By adjusting the posture respectively, the liquid level of the liquid in the liquid storage part of each liquid discharge unit does not tilt with respect to the liquid storage part, and in all the liquid discharge units, the amount of liquid in the liquid storage part and the liquid The relationship with the detection result of the surface height detecting means can be made the same. As a result, the amount of liquid in the liquid storage unit can be accurately detected based on the detection result of the liquid level height detecting means without changing the configuration for each liquid discharge head, and the parts management cost can be reduced. It is possible to reduce the cost of the device.

(Aspect 2)
In the first aspect, the posture adjusting means includes a holding member 90 that holds a liquid storage portion such as a sub tank 64, and a screw hole 104 provided in a mounting member such as a mounting base member 193 that rotatably supports the holding member 90. A plurality of fixing portions (screw holes 101a to 101c, screw holes 102a to 102c, screw holes) provided at different positions on the rotation trajectory of the holding member in the fulcrum portion and the mounting member to fix the holding member. 103a to 103c).
According to this, as described with reference to FIG. 6, by changing the fixing portion for fixing the holding member 90, the liquid level of the liquid such as ink I in the liquid storage portion such as the sub tank 64 becomes liquid storage. The posture of the liquid storage unit can be adjusted so that it is parallel to the bottom surface of the unit.

(Aspect 3)
In the first aspect, the posture adjusting means includes a holding member such as a holding member 90 that holds a liquid storage portion such as a sub tank 64, and a fulcrum portion such as a screw hole 104 provided in a mounting member that rotatably supports the holding member. , A fixing groove portion provided in the mounting member which extends along the rotation trajectory of the holding member and in which a fastening member such as a bolt for fastening the liquid storage portion can be slidably moved (first to third in the present embodiment). It has a groove portion 193a to 193c).
According to this, as described with reference to FIG. 8, by loosening the fastening of the holding member 90 to the mounting member such as the mounting base member 193 and rotating the holding member with the fulcrum as the fulcrum, a bolt or the like can be used. The fastening member of the above slides and moves in the fixing groove portion, and the posture of the liquid storage portion such as the sub tank 64 can be adjusted. Then, when the liquid level of the liquid such as ink I in the liquid storage unit is in the posture of the liquid storage unit so as to be parallel to the bottom surface of the liquid storage unit, the holding member is fastened to the mounting member with the fastening member. The liquid reservoir can be held in a posture in which the liquid level of the liquid in the liquid reservoir is parallel to the bottom surface of the liquid reservoir.

(Aspect 4)
The liquid discharge unit according to any one of aspects 1 to 3 includes a plurality of liquid discharge heads 60, and the liquid storage unit is a sub tank 64 connected to each of the plurality of liquid discharge heads.
According to this, even if the liquid discharge head consumes a large amount of liquid, it is possible to prevent the liquid in the liquid discharge head from being exhausted. Further, the pulsation generated by the pump when supplying the liquid from the main tank 65 can be reduced, and the influence of the pulsation on the liquid discharge head can be reduced.

(Aspect 5)
In the device for discharging the liquid provided with the liquid discharge unit 2, the liquid discharge unit according to any one of the first to fourth aspects is used as the liquid discharge unit 2.
According to this, the liquid can be discharged satisfactorily.

(Aspect 6)
In aspect 5, a cylindrical transport member such as a cylindrical drum 3 for transporting a liquid discharge medium such as paper 11 is provided, a plurality of liquid discharge units 2 are provided, and the plurality of liquid discharge units 2 rotate the transport member. They are arranged radially around the axis in the transport direction of the liquid discharge medium.
According to this, since each liquid discharge unit is provided with posture adjusting means, the liquids are arranged radially around the rotation axis of the transport member, and even if the inclination angles of the liquid discharge units are different from each other, each liquid is discharged. The posture of the liquid storage unit such as the sub tank of the unit can be set so that the liquid level of the liquid in the liquid storage unit is parallel to the bottom surface of the liquid storage unit.
As a result, a common liquid discharge unit can be used, the parts management cost can be reduced, and the cost cost of the device can be reduced.

(Aspect 7)
In the sixth aspect, the liquid storage portions such as the plurality of sub tanks 64 are all mounted members such as the mounting base member 193 so as to have the same posture with respect to the mounting surface on which the device for discharging the liquid such as a printer is mounted. It is attached to.
According to this, even if each liquid ejection unit is arranged at different inclination angles, the relationship between the detection result of the liquid level height detecting means such as the liquid level detection sensor 71 and the amount of ink in the liquid storage portion such as the sub tank 64. Can be the same.

1: Image forming unit 2: Liquid discharge unit 3: Cylindrical drum 11: Paper 60: Liquid discharge head 61: Head tank 62: Electromagnetic valve 63: Manifold 64: Sub tank 65: Main tank 66: Feed pump 71: Liquid level Detection sensor 72: Atmospheric release valve 80: Control unit 90: Holding member 92a: First screw through hole 92b: Second screw through hole 92c: Third screw through hole 92d: Fourth screw through hole 93: Mounting base member 101a: Screw hole 101b: Screw hole 101c: Screw hole 102a: Screw hole 102b: Screw hole 102c: Screw hole 103a: Screw hole 103b: Screw hole 103c: Screw hole 104: Screw hole (fulcrum)
193: Mounting base member 193a: First groove portion 193b: Second groove portion 193b: Third groove portion I: Ink

Japanese Unexamined Patent Publication No. 2010-005845

Claims (5)

A liquid discharge head that discharges liquid and
The liquid storage unit that stores the liquid and
In a liquid discharge unit provided with a liquid level height detecting means for detecting the liquid level in the liquid storage unit.
It has a posture adjusting means for adjusting the posture of the liquid storage portion with respect to the mounting member to which the liquid storage portion is attached.
The posture adjusting means is
A holding member that holds the liquid reservoir and
A fulcrum portion provided on the mounting member that rotatably supports the holding member, and
A liquid discharge unit characterized in that a fastening member extending along a rotation locus of the holding member and fastening the liquid storage portion has a fixing groove portion provided in the mounting member that can be slidably moved . In the liquid discharge unit according to claim 1 ,
A plurality of the liquid discharge heads are provided.
The liquid storage unit is a liquid discharge unit characterized by being a sub tank connected to each of the plurality of liquid discharge heads. In a device that discharges liquid equipped with a liquid discharge unit,
A device for discharging a liquid, which comprises using the liquid discharge unit according to claim 1 or 2 as the liquid discharge unit. In the device for discharging the liquid according to claim 3 ,
It is equipped with a cylindrical transport member that transports the liquid discharge medium.
A plurality of the liquid discharge units are provided.
A device for discharging a plurality of liquids, characterized in that the plurality of liquid discharge units are arranged in a radial pattern about the rotation axis of the transport member in the transport direction of the liquid discharge medium. In the device for discharging the liquid according to claim 4 ,
The plurality of liquid storage units discharge the liquid, characterized in that they are all attached to the mounting member so as to have the same posture with respect to the mounting surface on which the liquid discharging device is mounted. Device.

Images