JP6893774B2 - Inkjet printer - Google Patents

Description

The present invention relates to an inkjet printer, and more particularly to an inkjet printer having an ink head provided with an inkjet nozzle that ejects ink by an inkjet method.

In the present specification, the term "media" refers to various recording media made of paper such as plain paper, as well as various materials such as resin materials such as PVC and polyester, and materials such as aluminum, iron, and wood. Shall be included.

Further, in the present specification, the "inkjet method" includes various conventionally known methods including various continuous methods such as a binary deflection method and a continuous deflection method, and various on-demand methods such as a thermal method and a piezoelectric element method. It shall mean a printing method using the inkjet technology according to the above method.

Conventionally, the entire operation is controlled by a microcomputer, and liquid ink is supplied to an ink head equipped with an inkjet nozzle that ejects ink by an inkjet method on the surface facing the recording paper, which is a medium, and the supplied ink is supplied. There is known an inkjet printer in which ink is ejected from an inkjet nozzle onto a recording paper to print on the recording paper.

In such an inkjet printer, when the ink head has not been used for a considerable period of time without printing for a considerable period of time, the ink head is cleaned before printing is started in order to avoid poor ink ejection in the ink head. A cleaning operation may be performed.

In addition, if air bubbles are mixed in the inkjet nozzle of the ink head or ink is aggregated in the inkjet nozzle, the inkjet nozzle is clogged and poor ink ejection occurs. Perform the cleaning operation described above.

This cleaning operation means an operation in which ink is sucked from the inkjet nozzle of the ink head by a suction pump and the ink in the ink path is forcibly discharged to the outside of the ink head. Specifically, the cleaning operation was performed by the following procedure. First, the surface on which the inkjet nozzle of the ink head is formed by the cap member of the cap device (in the present specification, the surface on which the inkjet nozzle of the ink head is formed is appropriately referred to as the “inkjet nozzle surface”). Capping (sealing). Next, the suction pump is operated in this state to bring the capped inkjet nozzle surface to a negative pressure. As a result, the ink in the ink head is forcibly sucked from the inkjet nozzle to the cap member side.

By the cleaning operation of forcibly sucking and discharging the ink from the inkjet nozzle to the cap member side, the ink that has not been used for a long time is discharged to the outside of the ink head, and the fresh ink is sent from the ink cartridge into the ink head. As a result, the inside of the ink head is filled with fresh ink up to the surface of the inkjet nozzle, and as a result, the ejection state of the ink in the ink head is improved.

The inside of the cap member after the above-mentioned cleaning operation is filled with the ink sucked by the suction pump, and it is necessary to discharge the ink accumulated in the cap member. However, since the cap member is in close contact with the inkjet nozzle surface and is sucked by the suction pump, it is in a negative pressure state. Therefore, if the suction pump is rotated in such a state to suck and discharge the ink in the cap member, the ink is further sucked from the inkjet nozzle side because the cap member is not open to the atmosphere.

In order to prevent this, when discharging the ink accumulated in the cap member, a minute gap is opened between the cap member and the inkjet nozzle, and then the suction pump is operated to collect the ink in the cap member. I was trying to eject the ink.

In this specification, the positional relationship between the cap member and the inkjet nozzle when discharging the ink accumulated in the cap member, that is, the positional relationship between the cap member and the inkjet nozzle with a minute gap is defined as "empty". It is appropriately referred to as "suction position".

However, if the gap between the minute gaps set at the air suction position is too wide, ink will leak from the inside of the cap member when the gap is opened, causing problems such as soiling the inside of the inkjet printer. It was very difficult to adjust.

For this reason, conventionally, the work of adjusting the distance between the cap member and the inkjet nozzle at this air suction position has been performed by a serviceman who maintains the inkjet printer. Specifically, the serviceman manually adjusts the positions of the cap member and the ink head, and the inkjet printer determines the appropriate positional relationship between the cap member and the ink head when the ink accumulated in the cap member is discharged. It was stored in the storage unit of the controlled microcomputer, and the positional relationship stored in this storage unit was set as the empty suction position and stored in the storage unit. When the ink jet printer discharges the ink accumulated in the cap member by the cleaning operation, the inkjet printer reads out the empty suction position stored in the storage unit, and the positional relationship between the cap member and the ink head becomes the empty suction position. As described above, the cap member and the ink head are relatively moved.

However, there is a problem that the adjustment work of the distance between the cap member and the inkjet nozzle at the conventional air suction position largely depends on the experience value of the serviceman, and the accuracy has to depend on the personality of the serviceman. It was.

Further, in the conventional inkjet printer, poor ink ejection from the ink head due to clogging of the inkjet nozzle is determined based on the printing state on the medium. For this reason, the media may be wasted, and it has been desired to propose a method for detecting clogging of the inkjet nozzle before printing on the media.

Since the prior art that the applicant of the present application knows at the time of filing the patent application is not an invention related to an invention known in the literature, there is no prior art document information to be described in the specification of the present application.

The present invention has been made in view of the above-mentioned problems and demands in the prior art, and an object of the present invention is to automatically adjust the distance between the cap member and the inkjet nozzle at the air suction position. It is intended to provide an inkjet printer capable of doing so.

Another object of the present invention is to provide an inkjet printer capable of detecting clogging of an inkjet nozzle in an ink head before printing on a medium.

In order to achieve the above object, the present invention adjusts the distance between the cap member and the inkjet nozzle at the air suction position based on the state of negative pressure in the ink storage chamber in the damper device that stores the ink supplied to the ink head. Is done automatically.

Further, in the present invention, clogging of the inkjet nozzle in the ink head is determined based on the state of negative pressure in the ink storage chamber in the damper device for storing the ink supplied to the ink head.

That is, according to the present invention, in an inkjet printer that ejects ink from an inkjet nozzle of an ink head by an inkjet method, the ink head provided with the inkjet nozzle for ejecting ink communicates with the ink head and temporarily stores the ink. A damper device having an ink storage chamber to be formed, a negative pressure indicating member that is displaced according to a negative pressure that fluctuates according to a change in the amount of ink stored in the ink storage chamber, and a negative pressure indicating member of the damper device. A detection means for detecting the displacement of the ink head, a cap member for sealing the opening of the inkjet nozzle of the ink head, and a suction pump for supplying negative pressure to the cap member to suck ink from the inkjet nozzle of the ink head. And a storage means for storing the relative position indicating the relative positional relationship between the inkjet nozzle surface of the ink head and the cap member, and the relative position of the inkjet nozzle surface of the ink head and the cap member. When the moving means for changing the relative position and the moving means are used to change the relative position and the ink is sucked by the suction pump, the detecting means detects the displacement of the negative pressure indicating member. It has a determination means for determining whether or not the ink jet is present, and a control means for storing the relative position changed by the moving means in the storage means as an empty suction position based on the determination result of the determination means. is there.

Further, in the above invention, in the above invention, the air suction position is preset from the relative position at the timing when the displacement is detected from the state where the detection means does not detect the displacement of the negative pressure indicating member. It is a position where the inkjet nozzle surface and the cap member are separated by a distance.

Further, in the above invention, in the above invention, the control means sets a position where the inkjet nozzle surface and the cap member are separated from each other by a preset distance from the air suction position as a flushing position in the cap. ..

Further, according to the present invention, in an inkjet printer that ejects ink from an inkjet nozzle of an ink head by an inkjet method, the ink head provided with the inkjet nozzle for ejecting ink communicates with the ink head and temporarily stores the ink. A damper device having an ink storage chamber to be formed, a negative pressure indicating member that is displaced according to a negative pressure that fluctuates according to a change in the amount of ink stored in the ink storage chamber, and the negative pressure indicating member of the damper device. A detection means for detecting the displacement of the ink head, a cap member for sealing the opening of the inkjet nozzle of the ink head, and a suction pump for supplying negative pressure to the cap member to suck ink from the inkjet nozzle of the ink head. At the capping position where the inkjet nozzle surface is sealed by the cap member, whether or not the detecting means detects the displacement of the negative pressure indicating member when the ink is sucked by the suction pump. It is designed to have a determination means for determining.

Further, in the above invention, in the above invention, the damper device is attached to the case body so as to cover the hollow case body in which the opening is formed and the opening of the case body, and the ink together with the case body. The storage chamber is partitioned, and a pressure-sensitive film that can be flexed and deformed inside and outside the ink storage chamber, an inflow port formed in the case body and communicating with the ink storage chamber, and an inflow port into which the ink flows, and the case. The pressure-sensitive discharge outlet, which is formed in the main body and communicates with the ink storage chamber, and the ink flows out toward the ink ejection portion, and the pressure-sensitive film so as to bend the pressure-sensitive film to the outside of the ink storage chamber. An elastic member connected to the film, a bonded portion interposed between the pressure-sensitive film and the elastic member, and a bonded portion bonded to the pressure-sensitive film and a non-bonded portion not bonded to the pressure-sensitive film. It is provided with a pressure receiving plate to have, and at least a part of the non-joint portion is located on the center side of the pressure receiving plate with respect to the joint portion so that the non-joint portion is not closed by the joint portion. It is the one that was done.

Further, in the above invention, in the above invention, the damper device includes, as the negative pressure indicating member, a detection lever that detects the amount of ink stored in the ink storage chamber based on the bending deformation of the pressure sensitive film. The detection lever is arranged so as to be connected to the central portion of the surface of the pressure receiving plate facing the pressure sensitive film via the pressure sensitive film.

Since the present invention is configured as described above, it has an excellent effect that the distance between the cap member and the inkjet nozzle at the air suction position can be automatically adjusted.

Further, the present invention has an excellent effect that clogging of an inkjet nozzle in an ink head can be detected before printing on a medium.

FIG. 1 is a schematic configuration perspective explanatory view showing an example of an embodiment of an inkjet printer according to the present invention. FIG. 2 is a configuration explanatory view schematically showing an ink path in the inkjet printer shown in FIG. FIG. 3 is a side view showing the configuration of a damper device in the inkjet printer shown in FIG. FIG. 4 is a vertical cross-sectional view of the damper device shown in FIG. 3 taken along line IV-IV. FIG. 5 is a block configuration explanatory diagram showing a functional configuration related to the implementation of the present invention of the microcomputer in the inkjet printer shown in FIG. FIG. 6 is a flowchart showing a processing routine of position storage processing executed by the inkjet printer shown in FIG. 7 (a), (b), and (c) are explanatory views schematically showing the positional relationship between the inkjet nozzle surface on which the inkjet nozzle of the ink head is formed and the cap member. FIG. 7A shows the positional relationship between the cap member and the ink head at the capping position, and FIG. 7B shows the positional relationship between the cap member and the ink head at the air suction position. , FIG. 7C shows the positional relationship between the cap member and the ink head at the flushing position in the cap.

Hereinafter, an example of the embodiment of the inkjet printer according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a schematic configuration perspective explanatory view showing an example of an embodiment of an inkjet printer according to the present invention.

The inkjet printer 10 includes a fixed base member 14 supported by a base member 12 and extended in the main scanning direction. Side members 16L and 16R are arranged on the left and right ends of the base member 14, and side units 18 are arranged on the side member 16R side.

The inkjet printer 10 includes a central wall 20 that connects two left and right side members 16L and 16R, and a guide rail 22 that extends in the main scanning direction is arranged on the wall surface of the central wall 20.

Reference numeral 24 is a wire movably arranged in the main scanning direction parallel to the wall surface of the central wall 20. The carriage 26 is fixedly arranged on the wire 24 and slidably mounted on the guide rail 22. The carriage 26 is equipped with an ink head 30 so as to face the recording paper 28, which is a medium located on the base member 24, and a damper device 32 device connected to the ink head 30.

The overall operation of the inkjet printer 10 is controlled by the microcomputer 34.

Further, in the inkjet printer 10, the recording paper 28 is used as the medium as described above. The recording paper 28 is supplied onto the base member 14 by a paper feeding device (not shown), has a predetermined length in the main scanning direction which is the width direction, and has a predetermined length and is orthogonal to the main scanning direction, that is, recording. It is conveyed in the longitudinal direction of the paper 28. The direction orthogonal to the main scanning direction, that is, the transport direction of the recording paper 28 and the longitudinal direction of the recording paper 28 is hereinafter referred to as a "sub-scanning direction".

Then, in the inkjet printer 10, printing is performed on the recording paper 28 under the control of the microcomputer 34.

That is, when the wire 24 is moved by winding the wire 24 under the control of the microcomputer 10, the carriage 26 reciprocates in the going direction (outward path) and the returning direction (return path) in the main scanning direction as the wire 24 moves. Moving. As a result, the damper device 32 and the ink head 30 mounted on the carriage 26 move on the recording paper 28 supplied on the base member 14 by the paper feeding device in the going direction (outward path) and the returning direction (return path) in the main scanning direction. It reciprocates integrally with the printing paper 28 and prints on the recording paper 28.

In the inkjet printer 10, a waste liquid tank 42 is arranged on the base member 14, and an ink path 100 from an ink cartridge 36 detachably arranged on the side unit 18 to the waste liquid tank ink 42 is formed. (See FIG. 2).

The inkjet printer 10 is provided with a cap device 38 for capping the inkjet nozzle provided on the inkjet nozzle surface 30a of the ink head 30.

Reference numeral 40 is an operation panel provided with an operator for the operator to control the operation of the inkjet printer 10, and a display unit 40a for displaying the operating state of the inkjet printer 10 is provided.

Here, FIG. 2 shows a configuration explanatory diagram schematically showing the ink path 100 in the inkjet printer 10 shown in FIG.

The ink path 100 shown in FIG. 2 is connected to one end 102a so as to communicate with the ink cartridge 36, and to the other end 102b so that one end 104a of the connector 104 communicates with the ink cartridge 36. A flexible ink supply tube 102 is provided. The end 102b of the ink supply tube 102 and the end 104a of the connector 104 are detachably connected to each other.

The ink cartridge 36 stores ink for supplying to the ink head 30, and is provided with a sensor (not shown) that detects the amount of ink stored in the ink cartridge 36.

The connector 104 has a hollow pipe shape with a bendable bellows-like portion, and a damper device 32 is connected to the other end 104b.

The damper device 32 is mounted on the carriage 26 together with the ink head 30, and includes an ink storage chamber 123 (see FIGS. 3 and 4) for temporarily storing ink that has passed through the connector 104. The damper device 32 absorbs pressure fluctuations of ink in the ink path 100 when the carriage 26 reciprocates with respect to the recording paper 28.

The damper device 32 includes a detection lever 127 (see FIGS. 3 and 4) which is a negative pressure indicating member that is displaced according to a negative pressure that fluctuates according to a change in the amount of ink stored in the ink storage chamber 123. There is. The damper device 32 provided with the detection lever 127 is, for example, a conventionally known technique as disclosed in Japanese Patent No. 5951091 (see the description of the damper device in Japanese Patent No. 5951091). The configuration of the damper device 32 will be described later with reference to FIGS. 3 and 4.

The inkjet printer 10 is provided with a sensor 118 that detects the displacement of the detection lever 127. As the sensor 118, various sensors such as an optical sensor that detects the displacement of the detection lever 127 by light and a contact sensor that detects the displacement of the detection lever 127 from the contact state of the detection lever 127 can be appropriately used. .. The detection result by the sensor 118 is output to the microcomputer 34.

An ink head 30 provided with an inkjet nozzle (not shown) communicating with the ink storage chamber of the damper device 32 is connected to the damper device 32, and the ink stored in the ink cartridge 36 can be used for the damper device 32. It is supplied to the ink head 30 via the ink head 30. The ink supplied to the ink head 30 is ejected from the ink head nozzle opened in the inkjet nozzle surface 30a.

Further, in the ink supply tube 102, a valve valve 106 is provided between one end 102a and the other 102b. The valve valve 106 is composed of, for example, a solenoid valve. The valve valve 106 opens the valve valve 106 to allow the ink to be supplied from the ink cartridge 36 to the ink head 30, or closes the valve valve 106 to stop the supply of ink from the ink cartridge 36 to the ink head 30. You can selectively control the ink.

Further, in the inkjet printer 10, as described above, a cap device 38 for capping around the inkjet nozzle formed on the inkjet nozzle surface 30a of the ink head 30 is provided.

The cap device 38 includes a cap member 112 that seals the opening of the inkjet nozzle formed on the inkjet nozzle surface 30a of the ink head 30, and a suction pump 114 that can suck ink in the ink path 100. ing. The suction pump 114 supplies a negative pressure to the cap member 112 that seals the opening of the inkjet nozzle formed on the inkjet nozzle surface 30a of the ink head 30, and sucks the ink in the ink supply path 100.

Reference numeral 116 is a waste liquid tube, and one end portion 116a is connected to the cap member 112 and the other end portion 116b is connected to the waste liquid tank 42. The suction pump 114 is provided between one end 116a and the other end 116b of the waste liquid tube 116.

As the suction pump 114, those having various conventionally known configurations can be used, and for example, a tube pump, a trochoid pump, or the like can be used. Tube pumps and trochoidal pumps generate suction force by rotating rollers and gears in the pump.

Reference numeral 101 is a liquid feeding pump for feeding the ink in the ink path 100 to the damper device 32.

The inkjet printer 10 moves the ink head 30 by the motor 111 so that the positional relationship between the cap member 112 and the ink head 30 can be relatively changed between the capping position, the air suction position, and the flushing position in the cap. .. The motor 111 is controlled by the microcomputer 34.

FIG. 7A shows the positional relationship between the cap member 112 and the ink head 30 at the capping position, and FIG. 7B shows the positional relationship between the cap member 112 and the ink head 30 at the air suction position. It is shown, and FIG. 7C shows the positional relationship between the cap member 112 and the ink head 30 at the flushing position in the cap.

Here, the capping position shown in FIG. 7A is a positional relationship in which the cap member 112 completely seals the opening of the inkjet nozzle formed on the inkjet nozzle surface 30a of the ink head 30.

As described above, the air suction position shown in FIG. 7B is an inkjet formed on the inkjet nozzle surface 30a of the cap member 112 and the ink head 30 when the ink accumulated in the cap member 112 is discharged. The positional relationship with the nozzle, that is, the positional relationship between the cap member 112 having a minute gap G1 and the inkjet nozzle surface 30a.

The flushing position in the cap shown in FIG. 7C is a position where ink is ejected from the inkjet nozzle of the ink head 30 toward the cap member 112 for cleaning the inkjet nozzle of the ink head 30, and is an empty suction position. This is the positional relationship between the cap member 112 having a larger gap G2 and the inkjet nozzle surface 30a.

3 and 4 show the configuration of the damper device 32. FIG. 3 is a side view of the damper device 32. FIG. 4 is a vertical cross-sectional view of the damper device 32 shown in FIG. 3 taken along the line IV-IV. As shown in FIG. 4, the damper device 32 has a hollow-structured case body 121 having one surface (the surface on the right side of FIG. 4) open, and a damper attached to the outer wall surface of the case body 121 so as to cover the opening. It includes a film 122. The case body 121 is typically made of resin. The area surrounded by the case body 121 and the damper film 122 is the ink storage chamber 123. A detection lever 127 is arranged on the surface of the damper film 122 opposite to the ink storage chamber 123. The damper device 32 does not have a so-called valve structure.
As shown in FIG. 3, an ink inflow port 120 into which ink flows is formed on the wall surface (upper surface of FIG. 3) of the case body 121. The ink inlet 120 is connected to the other end 102b of the ink supply tube 102 and communicates with the ink cartridge 36. On the other wall surface (lower surface of FIG. 3) of the case main body 121, a discharge ink outlet 129a through which ink flows out is formed. The ejection ink outlet 129a communicates with the ink head 30. The ink inlet 120 and the ejection ink outlet 129a communicate with the ink storage chamber 123, respectively. The ink storage chamber 123 is formed in a rectangular parallelepiped shape. A predetermined amount of ink is temporarily stored in the ink storage chamber 123.
The damper film 122 is attached to the edge of the case body 121 by heat welding, for example, with a tension sufficient to bend the inside and outside of the ink storage chamber 123, respectively. The damper film 122 is an example of a pressure-sensitive film, and is configured to be flexible and deformable according to the pressure in the ink storage chamber 123. The damper film 122 is typically a flexible resin film. The damper film 122 may have a single-layer structure, or may have a multi-layer structure in which films of different materials are laminated and integrated. The surface of the damper film 122 on the ink storage chamber 123 side may be coated, for example, for the purpose of improving ink corrosion resistance.
As shown in FIG. 4, one end of the taper spring 124 is attached to the surface 121a of the case body 121 facing the damper film 122 inside the ink storage chamber 123. The other end of the taper spring 124 is connected to the pressure receiving plate 125. The taper spring 124 is connected to the damper film 122. The taper spring 124 is an example of an elastic member that presses the damper film 122 to the outside of the ink storage chamber 123. The taper spring 124 is maintained in a compressed state. As a result, the damper film 122 is pressed toward the outside of the ink storage chamber 123 (on the right side in FIG. 4) and is in a bent state. When the amount of ink stored in the ink storage chamber 123 is reduced to a predetermined amount and the inside of the ink storage chamber 123 is depressurized to some extent, the damper film 122 resists the spring force (elastic force) of the taper spring 124 and the ink storage chamber 123. Bends inward.
The tapered spring 124 has a truncated cone shape when it is not compressed, and is configured so that the inner diameter gradually changes in the height direction of the truncated cone shape. The taper spring 124 contracts in the height direction as it is compressed, and becomes a substantially flat plate when fully compressed. The taper spring 124 is arranged so that the inner diameter becomes smaller as it approaches the damper film 122 from the wall surface 121a of the case body 121. The material of the taper spring 124 is not particularly limited. The taper spring 124 may be coated, for example, for the purpose of improving ink corrosion resistance.
Inside the ink storage chamber 123, a pressure receiving plate 125 is arranged between the damper film 122 and the taper spring 124. The pressure receiving plate 125 is arranged substantially in the center of the damper film 122 so as to uniformly press the damper film 122 toward the outside of the ink storage chamber 123. The pressure receiving plate 125 has a disk shape. The pressure receiving plate 125 may be made of a material harder than the damper film 122. The pressure receiving plate 125 is preferably relatively lightweight so as not to hinder the bending deformation of the damper film 122. The pressure receiving plate 25 is made of, for example, a polyacetal resin.

The surface of the pressure receiving plate 125 facing the damper film 122 has a surface area of approximately 10% or more, typically 10 to 30%, for example, about 15 to 20% of the entire surface of the pressure receiving plate 125. By increasing the area of the surface facing the damper film 122, the damper film 122 can be uniformly pressed toward the outside of the ink storage chamber 123. Further, the bending deformation of the damper film 122 is accurately transmitted to the pressure receiving plate 125. On the other hand, if a pressure receiving plate having a large area is attached to the pressure sensitive film, the range of motion of the pressure sensitive film may be extremely limited. Therefore, the pressure receiving plate 125 and the damper film 122 are joined intermittently instead of being completely joined. As a result, the pressure receiving area of the pressure receiving plate 125 can be widened while maintaining the range of motion of the damper film 122. As a result, the damper film 122 smoothly bends and deforms as the ink capacity changes. The term "intermittent bonding" as used herein means that the pressure receiving plate 125 and the damper film 122 are not completely bonded, and a portion that is not bonded to the damper film 122 is intentionally (actively) left on the pressure receiving plate 125. Say.
The intermittent joint portion 126 has a joint portion 126a joined to the damper film 122 and a non-joint portion 126b not joined to the damper film 122. At least a part of the non-joint portion 126b is located on the central side of the pressure receiving plate 125 as compared with the portion closest to the edge portion of the joint portion 126a. The non-joint 126b is not closed by the joint 126a. That is, the non-joint portion 126b is opened so that air bubbles are less likely to accumulate in the intermittent joint portion 126. The joint portion 126a occupies an area of approximately 90% or less, typically 80% or less, for example 70% or less, of the entire surface of the pressure receiving plate 125 on the side facing the damper film 122. The non-joint portion 126b occupies an area of approximately 10% or more, typically 20% or more, for example, 30% or more of the entire surface of the pressure receiving plate 125 on the side facing the damper film 122.
In the intermittent joint portion 126, for example, the arrangement of the joint portion 126a and the non-joint portion 126b may be determined in consideration of the shapes of the damper film 122 and the ink storage chamber 123. In one example, the joint 126a is arranged so that the distance from the edge of the damper film 122 and / or the ink storage chamber 123 to the center of the pressure receiving plate 125 is substantially equal. For example, as shown in FIG. 3, when the damper film 122 and / or the ink storage chamber 123 has a polygonal shape, the joints are joined so that the distances from the apex of the polygon to the center of the pressure receiving plate 125 are substantially equal. It is preferable to arrange the portion 126a.
When the shape of the damper film 122 and / or the ink storage chamber 123 has rotational symmetry, for example, when the damper film 122 and / or the ink storage chamber 123 has a polygonal shape as shown in FIG. The joint portion 126a may also have rotational symmetry with the center 125c of the pressure receiving plate 125 as the center point. For example, it is preferable that the joint portions 126a are arranged at equal intervals on the same circumference centered on the center 125c of the pressure receiving plate 125. Alternatively, the joint portion 126a may be arranged radially with the center 125c of the pressure receiving plate 125 as the center point. As a result, the bending deformation of the damper film 122 is uniformly transmitted to the pressure receiving plate 125, and the pressure receiving plate 125 is stably displaced. Therefore, the accuracy of detecting the amount of ink stored can be improved.
A detection lever 127 is arranged outside the ink storage chamber 123. The detection lever 127 is an ink storage amount detecting device that detects the ink storage amount from the degree of bending deformation (position change) of the damper film 122. As shown in FIG. 3, the detection lever 127 is fixed to the wall surface of the case body 121 by two fixing portions 127b. The detection lever 127 is connected to the center 125c of the pressure receiving plate 125 via the damper film 122. The detection lever 127 is arranged so as to be able to advance and retreat with respect to the damper film 122 by the spring member 127c, and is always in contact with the damper film 122. The detection lever 127 is displaced based on the deflection deformation of the damper film 122.
For example, when the amount of ink stored in the ink storage chamber 123 decreases, the damper film 122 bends inside the ink storage chamber 123 by a predetermined amount. Along with the bending deformation of the damper film 122, the detection lever 127 is also displaced by a predetermined amount toward the ink storage chamber 123. On the contrary, when the ink is supplied to the ink storage chamber 123 and the ink storage amount increases, the damper film 122 bends to the outside of the ink storage chamber 123 by a predetermined amount. Along with the bending deformation of the damper film 122, the detection lever 127 is also displaced by a predetermined amount toward the direction away from the ink storage chamber 123. Therefore, based on the displacement information of the detection lever 127, it is possible to determine whether or not the amount of ink stored in the ink storage chamber 123 is within a predetermined range. For example, it is possible to determine whether or not the ink storage amount in the ink storage chamber 123 has reached a predetermined lower limit value and / or whether or not the ink storage amount has reached a predetermined upper limit value (full tank). it can.
The displacement of the detection lever 127 is detected by the sensor 118, and the detection signal in the sensor 118 is sent to the microcomputer 34. The microcomputer 34 drives or stops the liquid feed pump 101 in response to the detection signal of the sensor 118. According to the above configuration, the liquid feed pump 101 can be operated according to the amount of ink stored in the damper device 32. As a result, a predetermined amount of ink can be maintained in the ink storage chamber 123, and the ink can be stably supplied to the ink head 30.

Further, in connection with the implementation of the present invention, the microcomputer 34 moves the ink head 30 by controlling the operation of the motor 111 in response to the detection signal of the sensor 118.
As shown in FIG. 4, the detection lever 127 is connected to the center 125c of the pressure receiving plate 125. A convex portion 127a is provided at a position where the detection lever 127 is connected to the pressure receiving plate 125. On the other hand, a concave portion 125a is formed in the center 125c of the pressure receiving plate 125 connected to the convex portion 127a. The recess 125a protrudes inside the ink storage chamber 123 so that the tip (convex portion 127a) of the detection lever 127 on the ink storage chamber 123 side can be inserted. As a result, the detection lever 127 and the pressure receiving plate 125 are stably connected. Therefore, the degree of bending deformation of the damper film 122 is accurately transmitted to the detection lever 127, and the detection lever 127 can move stably.
At times other than printing, that is, when ink is not ejected from the ink head 30, a predetermined amount or more of ink is stored in the ink storage chamber 123 of the damper device 32. At this time, the damper film 122 is bent to the outside of the ink storage chamber 123 by the spring force of the taper spring 124. As a result, the inside of the ink storage chamber 123 is maintained at a negative pressure, and the inkjet nozzle surface 30a of the ink head 30 communicating with the ink storage chamber 123 is also maintained at a negative pressure. Therefore, ink leakage from the inkjet nozzle of the ink head 30 is prevented.

At the time of printing on the inkjet printer 10, ink is ejected from the inkjet nozzle of the ink head 30 toward the recording paper 28. When the ink is ejected from the inkjet nozzle, the ink stored in the ink storage chamber 123 of the damper device 32 is sucked out and supplied to the ink head 30. As a result, the amount of ink stored in the ink storage chamber 123 decreases, and the pressure inside the ink storage chamber 123 becomes negative. As the pressure inside the ink storage chamber 123 becomes negative, the damper film 122 bends and deforms inside the ink storage chamber 123. The pressure receiving plate 125 intermittently joined to the damper film 122 is also displaced according to the bending deformation of the damper film 122. This displacement is transmitted with high accuracy to the detection lever 127 connected to the pressure receiving plate 125. When the detection lever 127 is displaced, this displacement is detected by the sensor 118, and the detection signal in the sensor 118 is sent to the microcomputer 34. Based on the detection signal of the sensor 118, the microcomputer 34 determines that the ink storage amount is the predetermined lower limit value when the displacement amount of the detection lever 127 reaches a predetermined value, and drives the liquid feed pump 101. .. As a result, ink is sent from the ink cartridge 36 toward the damper device 32.
As the ink flows into the ink storage chamber 123 of the damper device 32, the negative pressure in the ink storage chamber 123 is eliminated. At the same time, the deflection of the damper film 122 is relaxed, and the pressure receiving plate 125 intermittently joined to the damper film 122 is also displaced. This displacement is transmitted with high accuracy to the detection lever 127 connected to the pressure receiving plate 125. When the detection lever 127 is displaced, this displacement is detected by the sensor 118, and the detection signal in the sensor 118 is sent to the microcomputer 34. Based on the detection signal of the sensor 118, the microcomputer 34 determines that the ink storage amount is the predetermined upper limit value (full tank) when the displacement amount of the detection lever 127 reaches a predetermined value, and causes the liquid feed pump 101 to operate. Stop. By driving the liquid feed pump 101 based on the displacement of the detection lever 127 in this way, a predetermined amount of ink is maintained in the ink storage chamber 123. As a result, it is prevented that the pressure inside the ink storage chamber 123 becomes too negative, and the ink is stably supplied from the ink cartridge 36 to the ink head 30. Therefore, at the time of printing, the ink can be stably ejected from the ink head 30.

Next, FIG. 5 shows a block configuration explanatory diagram showing a functional configuration related to the implementation of the present invention of the microcomputer 34 in the inkjet printer 10.

The microcomputer 34 is constructed with a control unit 202, a storage unit 204, a detection lever determination unit 206, and a motor control unit 208.

In addition to the process of storing the position of the ink head 30 in the capping position, the air suction position, and the flushing position in the cap, which is executed by the inkjet printer 10, the control unit 202 stores the position of the ink head 30 in the storage unit 204, as well as the printing process. , Controls the entire process including various processes such as air suction process and flushing process.

The storage unit 204 stores information used for various processes such as a printing process, an air suction process, and a flushing process, in addition to storing the positions of the ink head 30 at the capping position, the air suction position, and the flushing position in the cap.

The detection lever determination unit 206 determines whether or not the detection lever 127 is displaced by the detection signal output from the sensor 118.

The motor control unit 208 controls the operation of the motor 111 based on the determination result of the detection lever determination unit 206.

In the above configuration, in the inkjet printer 10, under the control of the microcomputer 34, the valve valve 106 is opened to supply ink from the ink cartridge 36 to the ink supply tube 102, and the recording paper is supplied from the ink head jet nozzle of the ink head 30. Ink is ejected to 28 to print on the storage paper 28.

In the inkjet printer 10, the operator operates the operation panel 40 to store the positions of the ink head 30 at the capping position, the air suction position, and the flushing position in the cap at the time of factory shipment or at the time of periodic maintenance after shipment. When the execution of the process to be stored in 204 is instructed, the inkjet printer 10 executes the following process under the control of the microcomputer 34.

First, a process of storing the position of the ink head 30 at the capping position will be described. The inkjet printer 10 gradually brings the ink head 30 closer to the cap member 112 under the control of the microcomputer 34, and sets the position where the inkjet nozzle surface 30a abuts on the cap member 112 as the position of the ink head 30 in the capping position. It is stored in the storage unit 204. Since a conventionally known technique can be used for the process of storing the position of the ink head 30 at the capping position, detailed description thereof will be omitted.

Next, a position memory process for storing the position of the ink head 30 at the air suction position and the flushing position in the cap will be described. FIG. 6 shows a flowchart showing a processing routine of position storage processing executed by the inkjet printer 10.

When the ink head 30 is in the capping position (position shown in FIG. 7A) where the inkjet surface 30a is capped by the cap member 112 of the cap device 38, the position memory processing is processed by the operation of the operation panel 40 by the user. When the execution of the routine is instructed, the processing routine of the position storage process shown in FIG. 6 is started.

When the processing routine of the position memory processing is started, the valve valve 106 is closed and the operation of the liquid feed pump 101 is stopped (step S602).

When the process of step S602 is completed, the process proceeds to step S604, the operation of the motor 111 is controlled by the motor control unit 208, and the sealing by the cap member 112 is released from the capping position shown in FIG. 7A. The ink head 30 is moved so as to be separated from the cap member 112. This movement of the ink head 30 is a very minute operation, and it is sufficient that the contact between the inkjet nozzle surface 30a and the cap member 112 is released and a slight gap is opened. Regarding the movement of the ink head 30, the moving distance may be set in advance, for example, moving by 1 mm.

When the process of step S604 is completed, the process proceeds to step S606, and the ink head 30 is moved so as to be further separated from the cap member 112. In step S606, when the suction pump 114 is operated to suck ink from the cap member 112 side, there is no possibility that ink is sucked from the inkjet nozzle of the ink head 30 by design. The ink head 30 is moved so that the ink head 30 and the cap member 112 are separated from each other. The moving distance of the ink head 30 is, for example, 20 mm.

When the process of step S606 is completed, the process proceeds to step S608, and the suction pump 114 is operated to start sucking ink from the cap member 112 side.

When the process of step S608 is completed, the process proceeds to step S610, and the ink head 30 is moved so as to approach the cap member 112 while operating the suction pump 114 to suck ink from the cap member 112 side. The movement of the ink head 30 is a very minute movement, and the moving distance may be set in advance, for example, moving by 1 mm.

When the process of step S610 is completed, the process proceeds to step S612, and it is determined whether or not the detection lever determination unit 206 has detected the displacement of the detection lever.

If the determination result in step S612 determines that the detection lever determination unit 206 does not detect the displacement of the detection lever (No), the process returns to step S610, and the determination result in step S612 is determined by the detection lever determination unit 206. The processes of steps S610 to S612 are repeated until it is determined (Yes) that the displacement of the detection lever has been detected.

On the other hand, when it is determined (Yes) that the detection lever determination unit 206 has detected the displacement of the detection lever, the process proceeds to step S614, the operation of the suction pump 114 is stopped, and ink is sucked from the cap member 112 side. To stop.

When the process of step S614 is completed, the process proceeds to step S616, and a preset minute distance (for example, 0) is set from the position of the ink head 30 at the timing when the detection lever determination unit 206 determines that the displacement of the detection lever has been detected. The position where the ink head 30 is separated from the cap member 112 by 1 mm is stored in the storage unit 204 as an air suction position which is a positional relationship between the cap member 112 having a gap G1 and the inkjet nozzle surface 30a. The reason why the position of the ink head 30 is set to the air suction position is to improve the ink suction efficiency at the time of air suction, and the air suction is performed at the position of the ink head 30 in which the detection lever 127 is displaced. This is because there is a risk of sucking ink from the inkjet nozzle of the ink head 30 toward the cap member 112 side.

When the process of step S616 is completed, the process proceeds to step S618, and the position where the ink head 30 is separated from the cap member 112 from the position of the ink head 30 stored in the storage unit 204 as the air suction position is set from the air suction position. The processing routine is terminated by storing in the storage unit 204 as the flushing position in the cap, which is the positional relationship between the cap member 112 having a larger gap G2 and the inkjet nozzle surface 30a. Regarding the separation distance from the air suction position of the ink head 30 to the flushing position in the cap, the separation distance may be set in advance, for example, by moving by 3 mm.

If flushing is performed at a position close to the inkjet nozzle surface, the mixed color ink (waste liquid) inside the cap member 112 may bounce off the inkjet nozzle surface. Considering that the vicinity of the inkjet nozzle is in a negative pressure state, the waste liquid may enter the inside of the inkjet nozzle, so that the position of the inkjet nozzle surface 30a needs to be considerably separated from the position of the cap member 112. However, if the separation is too large, the flushed ink may jump out of the cap member 112. In order to avoid this, it is necessary to set the position not too close and not too far, but for this position, a distance further separated from the air suction position may be set in advance based on the conventional experience.

In the inkjet printer 10, when air suction or flushing in the cap is performed during operation, the position of the ink head 30 stored in the storage unit 202 is read out and the ink head 30 is moved.

As described above, in the inkjet printer 10, the position of the ink head 30 at the air suction position is set based on the detection result of the displacement of the detection lever 127, and the ink head 30 and the cap member 112 at the air suction position are set. It will be possible to automatically adjust the interval with and without manual operation.

Further, in the inkjet printer 10, if the displacement of the detection lever 127 is not detected when the ink is sucked by the suction pump 114 at the capping position, the inkjet nozzle of the ink head 30 may be clogged. is there. As a result, clogging of the inkjet nozzle of the ink head 30 can be detected.

It should be noted that the above-described embodiment is merely an example, and the present invention can be implemented in various other embodiments. That is, the present invention is not limited to the above-described embodiment, and various omissions, replacements, and changes can be made without departing from the gist of the present invention.

For example, the above-described embodiment may be modified as shown in (1) to (4) below.

(1) In the above-described embodiment, the ink head 30 is moved when the positional relationship between the inkjet nozzle surface 30a of the ink head 30 and the cap member 112 is relatively changed, but this is limited to this. Of course, it is not something that can be done. For example, by moving the cap member 112, the positional relationship between the inkjet nozzle surface 30a of the ink head 30 and the cap member 112 may be relatively changed. Alternatively, by moving both the ink head 30 and the cap member 112, the positional relationship between the inkjet nozzle surface 30a of the ink head 30 and the cap member 112 may be relatively changed.

(2) In the above-described embodiment, a specific numerical value (for example, a distance when moving the ink head 30) is shown. It goes without saying that these specific numerical values in the present specification are merely examples for facilitating the understanding of the present invention, and the present invention is not limited to these numerical values.

(3) In the above-described embodiment, the configuration of the damper device 32 has been described with reference to FIGS. 3 and 4, but the damper device 32 is not limited to this configuration. The damper device 32 may be provided with a negative pressure indicating member (corresponding to the detection lever 27 in the damper device 32) indicating a negative pressure state in the ink storage chamber for storing ink, and various known forms are used. You can.

(4) In the above-described embodiment, the above-described embodiment and the above-mentioned modifications (1) to (3) may be appropriately combined.

The present invention is suitable for use in an inkjet printer that ejects ink from an ink head by an inkjet method to perform predetermined printing.

10 Inkjet Printer, 30 Ink Head, 30a Inkjet Nozzle Surface, 32 Damper Device, 34 Microcomputer, 36 Ink Cartridge, 38 Cap Device, 40 Operation Panel, 40a Display, 42 Waste Liquid Tank, 100 Ink Path, 101 Liquid Feed Pump, 106 valve valve, 111 motor (moving means), 112 cap member, 114 suction pump, 118 sensor (detecting means), 120 ink inlet (inlet), 121 case body, 122 damper film (expandable member), 123 ink storage Chamber (liquid storage chamber), 124 taper spring (elastic member), 125 pressure receiving plate, 126 intermittent joint, 127 detection lever (negative pressure indicator), 129a ejection ink outlet (ejection outlet), 202 control Unit (control means), 204 storage unit (storage means), 206 detection lever determination unit (determination means), 208 motor control unit

Claims (4)

In an inkjet printer that ejects ink from the inkjet nozzle of the ink head by the inkjet method.
An ink head equipped with an inkjet nozzle that ejects ink,
An ink storage chamber that communicates with the ink head and temporarily stores the ink, and a negative pressure indicating member that displaces according to a negative pressure that fluctuates with a change in the amount of ink stored in the ink storage chamber. With the damper device
A detecting means for detecting the displacement of the negative pressure indicating member of the damper device, and
A cap member that seals the opening of the inkjet nozzle of the ink head, and
A suction pump that supplies negative pressure to the cap member and sucks ink from the inkjet nozzle of the ink head.
A storage means for storing a relative position indicating a relative positional relationship between the inkjet nozzle surface of the ink head and the cap member, and
A moving means for changing the relative position, which is a relative positional relationship between the inkjet nozzle surface of the ink head and the cap member,
A determining means for determining whether or not the detecting means has detected the displacement of the negative pressure indicating member when the relative position is changed by the moving means and the ink is sucked by the suction pump.
Based on the determination result of the determination means, the position where the inkjet nozzle surface and the cap member are separated from the relative position at the timing when the detection means detects the displacement by a preset distance is set as the air suction position. An inkjet printer characterized by having a control means for storing in a storage means. In the inkjet printer according to claim 1,
The control means is an inkjet printer, wherein a flushing position in the cap is a position where the inkjet nozzle surface and the cap member are separated from each other by a preset distance from the air suction position. In the inkjet printer according to any one of claims 1 or 2.
The damper device is
A hollow case body with an opening and
A pressure-sensitive film attached to the case body so as to cover the opening of the case body, partitioning the ink storage chamber together with the case body, and flexing and deforming inside and outside the ink storage chamber.
An inflow port formed in the case body, communicating with the ink storage chamber, and inflowing the ink,
A discharge outlet formed in the case body, communicating with the ink storage chamber, and discharging the ink toward the ink ejection portion.
An elastic member connected to the pressure-sensitive film so as to bend the pressure-sensitive film to the outside of the ink storage chamber.
A pressure receiving plate that is interposed between the pressure sensitive film and the elastic member and has a joint portion bonded to the pressure sensitive film and a non-joint portion not bonded to the pressure sensitive film is provided.
An inkjet printer characterized in that at least a part of the non-joint portion is located closer to the center of the pressure receiving plate than the joint portion, and the non-joint portion is not closed by the joint portion. In the inkjet printer according to claim 3,
The damper device includes, as the negative pressure indicating member, a detection lever that detects the amount of ink stored in the ink storage chamber based on the bending deformation of the pressure sensitive film.
An inkjet printer characterized in that the detection lever is arranged so as to be connected to a central portion of a surface of the pressure receiving plate facing the pressure sensitive film via the pressure sensitive film.

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