JP2011136466A - Maintenance device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a maintenance device which efficiently removes quantitatively variable liquid droplets attached even to a blade or a cap by a simple and compact structure, and also to provide an image forming device using the maintenance device. <P>SOLUTION: The maintenance device 5 has: a movable capping means 8 for covering a nozzle surface 2 of a recording head 1; a movable blade means 11 for wiping the nozzle surface 2; a cleaning means 33 coming into contact with the capping means 8 and the blade means 11, and removing liquid droplets 13 attached to the capping means 8 and the blade means 11; and a maintenance mode selecting means for selecting one of a plurality of maintenance modes in which the number of discharge times and the discharge amounts of liquid droplets 13 from the recording head 1 are varied, respectively. The device is also equipped with a controller 71 for controlling a contact state between the capping means 8 and the blade means 11, and the cleaning means 33 corresponding to the maintenance mode selected by the maintenance mode selecting means. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a developing device and a process cartridge that can be used in an electrophotographic image forming apparatus.

  As a maintenance device for maintaining the nozzle surface of the recording head that discharges droplets, a device that wipes the nozzle surface of the recording head with a blade is known. However, in this apparatus, when the nozzle surface is wiped with a blade, the wiped liquid droplets adhere to the blade and become dirty, and when the next wiping is performed in this state, the liquid droplet retransfers to the nozzle surface and discharge failure occurs. There is a fear. In order to prevent this problem, a technique is already known in which blade cleaning means is provided to scrape droplets adhering to the blade. However, the above-described blade cleaning means has a problem that droplets cannot be sufficiently scraped when the contact between the blade and the scraping means provided in the blade cleaning means is uneven. In addition, the droplets scraped by the scraping means accumulate on the scraping means, and there is a problem that the means for removing this is required, the configuration becomes complicated, and the working efficiency deteriorates due to the operation of the removing means. .

  In addition, other maintenance devices for the nozzle surface perform regular preliminary ejection to prevent ink thickening in the recording head, and recovery operation by discharging the ink in the recording head from the nozzle by the pressurizing means For example, there is known a type in which a cap is brought into contact with a nozzle surface of a recording head and a recovery operation is performed by sucking ink in the recording head by a suction unit. All of the ink sucked by the cap flows into the cap and is discharged to the waste liquid tank portion by the action of the suction means. This cap also functions to prevent the ink in the recording head from drying, and keeps the nozzle surface moist by contacting the nozzle surface. At this time, if capping is performed with the ink adhering to the cap surface that contacts the nozzle surface, the ink adheres to the nozzle surface as a cap mark, and this ink thickens or dries so that the cap mark is removed during the next wiping. There is a possibility that an improper wiping cannot be performed by dragging, resulting in ejection failure.

  In order to solve the above-described problems, a technique for cleaning a cap with a cap wiper and removing ink adhering to the cap wiper with a cleaning member is disclosed in, for example, “Patent Document 1”.

  The droplets ejected from the recording head vary in viscosity depending on the environment, and are low in a high temperature environment and high in a low temperature environment. For this reason, the amount and quality of the droplets adhering to the blades and caps of the maintenance device vary depending on the environmental conditions, and depending on the environmental conditions, the droplets of the recording head cannot be completely removed by the maintenance device. There is a problem that it occurs.

  In addition, as a maintenance mode in the maintenance device, a normal mode that is performed when a specific color is not output or faint, a refresh mode that is performed when the normal mode is repeated and the problem is not recovered, and a refresh mode are performed. There is also known a maintenance device having a plurality of modes such as an emergency mode which is performed when a problem does not recover. Even in such a maintenance device, there is a problem in that the amount of droplets adhering to the blade and the cap varies in each mode, so that the droplets cannot be sufficiently removed in all modes, causing problems.

  The present invention solves the above-described problems, and a maintenance device capable of efficiently removing even a blade and a cap to which droplets with quantitative variations are attached with a simple and compact mechanism, An object is to provide an image forming apparatus used.

  The invention according to claim 1 is a recording head maintenance apparatus for discharging droplets onto a recording medium, and a movable cap means for covering the nozzle surface of the recording head and a movable blade for wiping the nozzle surface. And a cleaning means that removes droplets attached to the cap means and the blade means in contact with the cap means and the blade means, and the number of discharges and the discharge amount of the droplets from the recording head are different. A maintenance mode selection means for selecting any one of a plurality of maintenance modes, wherein the cap means, the blade means and the cleaning means are contacted according to the maintenance mode selected by the maintenance mode selection means. Characterized by having control means for controlling the situation To.

  According to a second aspect of the present invention, in the maintenance apparatus according to the first aspect, the cap means and the blade means are capable of reciprocating in a direction contacting and separating from the cleaning means, and the control means includes the cap means and the cap means. The contact time between the blade means and the cleaning means is controlled.

  According to a third aspect of the present invention, in the maintenance apparatus according to the first aspect, the cap means and the blade means are capable of reciprocating in a direction contacting and separating from the cleaning means, and the control means includes the cap means and the cap means. The number of contacts between the blade means and the cleaning means is controlled.

  According to a fourth aspect of the present invention, in the maintenance apparatus according to the first aspect, the cap means and the blade means are reciprocally moved in a contact / separation direction in which the cap means and the blade means are in contact with and away from the cleaning means The control means may control the number of movements in the orthogonal direction in a state where the cap means and the blade means are in contact with the cleaning means.

  According to a fifth aspect of the present invention, in the maintenance apparatus according to any one of the first to fourth aspects, the control means further contacts the cap means, the blade means, and the cleaning means in accordance with environmental conditions. It is characterized by controlling.

  According to a sixth aspect of the present invention, in the maintenance apparatus according to any one of the first to fifth aspects, the cleaning unit contacts the cap unit and the blade unit and adheres to the cap unit and the blade unit. A cleaning member that removes the droplets, and the cleaning member is configured to be able to update a portion in contact with the cap unit and the blade unit.

  A seventh aspect of the invention is an image forming apparatus having the maintenance device according to any one of the first to sixth aspects.

  The invention according to claim 8 is the image forming apparatus according to claim 7, wherein a plurality of the recording heads are arranged in the width direction of the recording medium.

  According to the present invention, when the cap unit and the blade unit soiled with droplets are cleaned by the cleaning unit, the contact state (contact time, number of contacts, reciprocation) of the cap unit, the blade unit and the cleaning unit according to the maintenance mode. Since the number of movements and the number of reciprocating movements of the housing are controlled, the droplets adhering to the cap unit and the blade unit can be reliably cleaned, and a good recording operation can be performed after the cleaning.

1 is a schematic diagram of a recording head applicable to an embodiment of the present invention. 1 is a schematic view of a recording head and a maintenance device used in an embodiment of the present invention. It is the schematic explaining the maintenance operation | movement of the maintenance apparatus used for one Embodiment of this invention. It is the schematic explaining the maintenance operation | movement of the maintenance apparatus used for one Embodiment of this invention. It is the schematic explaining the maintenance operation | movement of the maintenance apparatus used for one Embodiment of this invention. It is the schematic explaining the moving mechanism of the maintenance apparatus used for one Embodiment of this invention. It is the schematic explaining the moving mechanism of the maintenance apparatus used for one Embodiment of this invention. It is the schematic explaining the moving mechanism of the maintenance apparatus used for one Embodiment of this invention. It is the schematic explaining the moving mechanism of the maintenance apparatus used for one Embodiment of this invention. It is the schematic explaining the maintenance apparatus which has the cleaning means used for one Embodiment of this invention. It is the schematic explaining the maintenance apparatus which has the cleaning means used for one Embodiment of this invention. It is the schematic explaining the cleaning operation | movement of the maintenance apparatus used for one Embodiment of this invention. It is the schematic explaining the cleaning operation | movement of the maintenance apparatus used for one Embodiment of this invention. It is the schematic explaining the cleaning operation | movement of the maintenance apparatus used for one Embodiment of this invention. It is the schematic explaining the cleaning operation | movement of the maintenance apparatus used for one Embodiment of this invention. It is a flowchart explaining the cleaning operation | movement of the maintenance apparatus used for one Embodiment of this invention. It is a graph which shows the relationship between the maintenance mode and environmental conditions, and cleaning operation | movement in one Embodiment of this invention. It is the schematic explaining the maintenance apparatus which has the cleaning means used for the modification of one Embodiment of this invention. It is a flowchart explaining the cleaning operation | movement of the maintenance apparatus used for the modification of one Embodiment of this invention. It is a schematic diagram which shows the condition of the cleaning member in the cleaning operation | movement of the maintenance apparatus used for the modification of one Embodiment of this invention. It is the schematic explaining the maintenance apparatus which has the cleaning means used for the modification of one Embodiment of this invention. 1 is a schematic view of an image forming apparatus equipped with a maintenance device having cleaning means used in an embodiment of the present invention. 1 is a schematic view showing a recording head used in an embodiment of the present invention. It is a schematic plan view explaining the maintenance apparatus used for one Embodiment of this invention. It is a schematic front view explaining the maintenance apparatus used for one Embodiment of this invention. FIG. 2 is a control block diagram of an image forming apparatus equipped with a maintenance device having a cleaning unit used in an embodiment of the present invention. It is a flowchart of the cleaning operation at the time of each maintenance mode and each idle discharge implementation in one embodiment of the present invention.

  FIG. 1 shows a recording head 1 used in an image forming apparatus that forms an image by ejecting droplets onto a recording medium. A droplet is ejected onto a nozzle surface 2 that is a droplet ejection surface of the recording head 1. A plurality of nozzles 3 for discharging water are arranged in parallel. The recording head 1 is supported by a recording head holder 4 as shown in FIG. 2, and the recording head holder 4 is configured to be movable in the horizontal direction and the vertical direction in FIG.

  In FIG. 2, a maintenance device 5 that performs maintenance of the recording head 1 is disposed near the lower portion of the recording head holder 4. The maintenance device 5 includes a cap 6 having a cap 6 covering the nozzle surface 2 of the recording head 1 and a cap holder 7 for supporting the cap 6, a blade 9 for wiping the nozzle surface 2, and a blade means having a blade holder 10 for supporting the blade 9. 11, the cap means 8 and the blade means 11 are supported by the housing 12 of the maintenance device 5 so as to be movable in the vertical direction in FIG. A suction unit (not shown) that sucks the droplets discharged from the recording head 1 is provided below the cap 6.

  Next, the maintenance operation of the recording head 1 using the maintenance device 5 will be described. First, as shown in FIG. 3, the recording head holder 4 approaches the maintenance device 5, and the cap unit 8 approaches the recording head 1 by the operation of the cap moving unit described later, and the nozzle 6 of the recording head 1 is moved by the cap 6. cover. Then, when a suction unit (not shown) is operated, droplets, bubbles, and the like in the recording head 1 are discharged and maintenance is performed. In the present embodiment, a method of performing maintenance by suction using a suction unit has been described. However, a pressure unit (not shown) is used without using the suction unit, and droplets, bubbles, and the like in the recording head 1 are discharged. It may be configured. The discharged waste liquid is discharged into the cap 6 and sucked by the suction means. The cap 6 also has a moisturizing function for preventing the droplets in the recording head 1 from drying, and the liquid in the recording head 1 is capped by contacting the nozzle surface 2 so as to cover the nozzle 3 of the recording head 1. Drop drying can be prevented. Furthermore, by performing preliminary discharge (idle discharge) in the capped state, drying in the recording head 1 is further prevented. The preliminarily discharged liquid droplets are discharged into the cap 6 and sucked by the suction means. The preliminary discharge may be performed with the cap 6 in contact with the nozzle surface 2 or may be performed in a separated state.

  FIG. 4 shows a state in which the droplets 13 are attached to the nozzle surface 2 of the recording head 1 after the suction (pressure) operation is completed. In this state, the wiping of the nozzle surface 2 is performed by the blade means 11. Here, since a certain amount of biting is required between the nozzle surface 2 and the blade 9, a height difference h is provided between the upper surface of the cap 6 and the upper surface 9 a of the blade 9. FIG. 5 shows a state after wiping. The housing 12 of the maintenance device 5 is moved in the wiping direction indicated by an arrow A in the drawing by a mechanism described later, and the droplets 13 adhering to the nozzle surface 2 are wiped off by the blade 9. At this time, the liquid droplet 13 is attached to both the upper surface 9a and the wiping surface 9b of the blade 9, and when the next wiping is performed in this state, the liquid droplet 13 attached to the blade 9 becomes the nozzle surface 2. There is a risk of poor transfer and maintenance. Further, the droplet 13 discharged from the recording head 1 is also attached to the upper surface of the cap 6 that is in contact with the nozzle surface 2. When the next capping is performed in this state, a cap mark is attached to the nozzle surface 2. There is a possibility that the droplets of the cap marks are thickened and dried, and the cap marks are dragged by wiping at the time of the next maintenance. Therefore, it is necessary to remove the droplet 13 attached to the blade 9 and the cap 6 by the cleaning means.

  6, 7 and 8 are diagrams for explaining a moving mechanism for moving the cap means 8 and the blade means 11 in the vertical direction. A cam pin 14 is attached to the cap holder 7 of the cap means 8, and a cam pin 15 is attached to the blade holder 10 of the blade means 11, and each holder 7, 10 is illustrated by a slide rail (not shown) provided on the housing 12. Are supported so as to be movable in the vertical direction, and are biased downward by a spring 18. A cam 16 that contacts the cam pin 14 is rotatably supported by the housing 12 around the support shaft 16a below the cap holder 7, and a cam 17 that contacts the cam pin 15 is supported below the blade holder 10 by the support shaft 17a. Is supported by the housing 12 so as to be rotatable. A pulley 19 is attached to one end of the support shaft 16a, and a pulley 20 is attached to one end of the support shaft 17a. A timing belt 21 is attached to the pulley 19, and a timing belt 22 is attached to the pulley 20. Each of the timing belts 21 and 22 is respectively hung on a double pulley 23 coaxially having two pulleys and rotatably supported by the housing 12, and a worm wheel (not shown) is provided on a support shaft of the double pulley 23. A worm 25 attached to the output shaft of the motor 24 capable of forward and reverse rotation is engaged with the worm wheel. A one-way clutch is interposed inside the double pulley 23. For example, when the motor 24 rotates in the forward direction, the cam 16 rotates and the cap means 8 moves up and down, and when the motor 24 rotates in the reverse direction, the cam 17 rotates. Thus, the blade means 11 is configured to move up and down. The motor 24 is a stepping motor supported by the housing 12 and is rotationally controlled by pulse control.

  FIG. 9 is a diagram illustrating a moving mechanism for moving the housing 12 in the wiping direction indicated by the arrow B in FIG. In the figure, two sliders 26 are fixed to the housing 12, and a timing belt 27 is fixed to each slider 26. One end of the timing belt 27 is hung on a pulley 28, and the other end is hung on one side of a double pulley 29 having two pulleys on the same axis. One end of a timing belt 30 is hung on the other side of the double pulley 29, and the other end of the timing belt 30 is hung on a pulley 32 fixed to an output shaft of a motor 31 capable of forward and reverse rotation. The motor 31 is a stepping motor, and is rotationally controlled by pulse control. When the motor 31 rotates forward and backward, the housing 12 is reciprocated in the arrow B direction.

  FIG. 10 shows a cleaning unit that performs the maintenance operation and cleans the cap 6 and the blade 9 that are contaminated by the droplets 13 as shown in FIG. In the figure, the cleaning means 33 has a guide portion 34 and an absorber 35. An absorbent body 35 made of a non-woven fabric capable of absorbing the droplets 13 such as polyethylene terephthalate is disposed along the guide portion 34. The absorbent body 35 has a horizontal surface 35a for cleaning the upper surface 9a of the blade 9 and the cap 6. And a vertical surface 35b for cleaning the wiping surface 9b of the blade 9 is formed. The length L1 of the absorbent body 35 in the depth direction in FIG. 10 is formed to be longer than the length L2 of the cap 6 and the blade 9, so that the entire length of the cap 6 and the blade 9 can be cleaned at a time. It is configured.

The basic cleaning operation of the maintenance device 5 after the maintenance operation by the cleaning means 33 will be described with reference to the operation diagrams shown in FIGS. 12 to 15 and the flowchart shown in FIG.
When a signal indicating that the maintenance of the recording head 1 has been completed is input to a control unit (not shown) (ST01), the process proceeds to cleaning of the cap 6 and the blade 9 to which the droplets 13 are attached. After completion of the maintenance operation, the cap 6 and the blade 9 are kept at substantially the same height as shown in FIG. First, in order to clean the wiping surface 9b of the blade 9, the motor 24 reverses and the blade 9 moves up as indicated by an arrow C in FIG. 12 (ST02). Next, the motor 31 is actuated to move the housing 12 in the direction indicated by the arrow D in FIG. 12 (ST03), and the wiping surface 9b contacts the vertical surface 35b of the absorber 35 and adheres to the wiping surface 9b. The droplet 13 is removed by the absorber 35. In the state in which the wiping surface 9b and the vertical surface 35b are in contact with each other, in this embodiment, this state is maintained for a predetermined time, and the droplet 13 is absorbed by the absorber 35 during this time (ST04). This predetermined time will be described later.

  Next, after the motor 24 is rotated in the reverse direction and the blade 9 is returned to the position shown in FIG. 10 (ST05), the motor 31 is operated and the housing 12 is further moved in the direction of arrow D (ST06). When 9 is positioned below the horizontal surface 35a of the absorber 35, the operation of the motor 31 is stopped. After the motor 31 is stopped, the motor 24 reverses, and the blade 9 rises as shown by the arrow E in FIG. 13 (ST07), and the upper surface 9a of the blade 9 contacts the horizontal surface 35a. Even in a state where the upper surface 9a and the horizontal surface 35a are in contact with each other, in this embodiment, this state is maintained for a predetermined time, and the droplet 13 is absorbed by the absorber 35 during this time (ST08). Here, the rising amount of the blade 9 is an intermediate point that is lower than that of the previous wiping surface 9 b and higher than the upper surface of the cap 6. When the predetermined time has elapsed, the cleaning of the droplets 13 attached to the upper surface 9a and the wiping surface 9b of the blade 9 is completed.

  When the cleaning of the blade 9 is completed, the motor 24 rotates reversely and the blade 9 is returned to the position shown in FIG. 10 (ST09), and then the motor 24 rotates forward and the cap 6 is moved as shown by the arrow F in FIG. Ascending (ST10), the upper surface of the cap 6 contacts the horizontal surface 35a. Even in a state where the upper surface and the horizontal surface 35a are in contact with each other, in this embodiment, this state is maintained for a predetermined time, and during this time, the droplets 13 are absorbed by the absorber 35 (ST11). After a predetermined time has elapsed, the droplet 13 is absorbed by the absorber 35 and the cleaning of the cap 6 is completed. When the cleaning of the cap 6 is completed, the motor 24 rotates forward and the cap 6 descends as shown by an arrow G in FIG. 15 (ST12), and the cap 6 is returned to the position shown in FIG. Is completed. In the above description, the cap 6 is cleaned after the blade 9 is cleaned. However, the cap 6 is not limited to this order, and both may be cleaned simultaneously.

  In the configuration described above, the housing 12 of the maintenance device 5 is moved in the wiping direction by the motor 31 and the cleaning means 33 is fixed. However, the cleaning means 33 is equipped with a moving means in the wiping direction, and the cap 6 and the blade 9 are mounted. The cleaning unit 33 may be moved in a state where the cleaning member 33 is in contact with the absorber 35 to perform cleaning.

  Next, a series of operations up to the cleaning operation by the cleaning unit 33 will be described. The cleaning operation of the cap 6 and the blade 9 is basically performed after the maintenance operation. As described above, the maintenance operation includes a wiping operation in which the droplet 13 in the recording head 1 is sucked (or pressurized) and discharged, and the droplet 13 adhering to the nozzle surface 2 is wiped by the blade 9. There is a preliminary discharge (empty discharge) that is periodically performed to prevent drying of the droplets 13 in the head 1. When the liquid droplet 13 is discharged from the recording head 1 by suction, the liquid droplet 13 adheres to the cap 6 and becomes dirty. After that, when the nozzle surface 2 is wiped with the blade 9, the upper surface 9a and the wiping surface 9b of the blade 9 become dirty. Preliminary ejection is performed in the cap 6. However, since the amount of the droplets 13 ejected from the recording head 1 by the preliminary ejection is very small, the cap 6 is not violently soiled. In the configuration of this embodiment, the cleaning operation is performed. However, the cleaning operation of the cap 6 may be performed after the preliminary discharge in order to improve the cleaning property of the cap 6. In this embodiment, the order is maintenance operation → cleaning operation → maintenance operation. After the maintenance operation is completed, droplets can be ejected onto the recording medium. The recording operation may be performed immediately after the maintenance operation is completed, and the cleaning operation may be performed during the maintenance operation, or the recording operation may be performed after the cleaning operation is completed.

  In the present embodiment, two types of modes can be selected as a maintenance mode for performing a maintenance operation. This mode is selected by maintenance mode selection means (not shown) provided in the maintenance device 5. One is a normal maintenance mode, and a normal mode in which a suction operation is performed for a fixed time in order to obtain a certain amount (for example, 0.2 cc) of ink suction from the recording head 1, and the other is a mode from the normal mode. Is a refresh mode that increases the amount of suction (for example, 1 cc). At this time, since the amount of the droplets 13 discharged from the recording head 1 is different, the amount of the droplets 13 attached to the cap 6 and the blade 9 is also different due to the maintenance operation. Moreover, since the viscosity of the droplet 13 also changes according to the change in environmental conditions, the amount of the droplet 13 attached to the cap 6 and the blade 9 changes. In order to cope with such a quantitative change of the droplet 13, in this embodiment, in the above-described cleaning operation, the contact time between the absorber 35, the cap 6 and the blade 9 is changed in steps ST04, ST08 and ST11 of FIG. The cap 6 and the blade 9 are more reliably cleaned. When the amount of the droplet 13 is large, the contact time (predetermined time) is set to be long, and the amount of the droplet 13 absorbed into the absorber 35 is increased. Furthermore, a configuration in which the number of contacts with the absorber 35 is changed by reciprocating the cap 6 and the blade 9 in the vertical direction, or a configuration in which the contact time and the number of contacts are used together may be employed. Further, as indicated by an arrow H in FIG. 13, a configuration in which the motor 31 is rotated in the forward and reverse directions while the blade 9 (or the cap 6) is in contact with the absorber 35 and the housing 12 is reciprocated may be adopted. Good.

  A specific example of the above-described cleaning operation will be described. In the normal mode, the contact time of the cap 6 and the blade 9 with the absorber 35 is 1 second, and the cap 6 and the blade 9 are not reciprocated. In the refresh mode, the amount of the droplets 13 adhering to the cap 6 and the blade 9 is large. Therefore, in order to perform reliable cleaning, the contact time with the absorber 35 is set to 2 seconds longer than the normal mode, and the cap 6 and the blade 9 are reciprocated to contact the absorber 35 a plurality of times, and the droplet 35 is reliably absorbed by the absorber 35 to perform cleaning.

  FIG. 17 shows the contact state between the cap 6 and the blade 9 and the absorber 35 during the cleaning operation according to the maintenance mode and environmental conditions. In this embodiment, when the environmental condition is normal temperature or high temperature in the normal mode, the contact time between the cap 6 and the blade 9 and the absorber 35 is set to 1 second, and reciprocation is not performed. When the environmental condition is a low temperature, the viscosity of the droplet 13 increases, so the contact time is set to 2 seconds in order to improve the absorbability to the absorber 35. When the environmental condition is normal temperature or high temperature in the refresh mode, the amount of droplets 13 ejected from the recording head 1 increases in the refresh mode, so that the contact time is 2 seconds and no reciprocation is performed. When the environmental condition is low temperature, reciprocation is performed to perform more reliable cleaning. In addition, the numerical value quoted here is an example, and can be appropriately changed according to the property of the droplet 13, the environmental condition, and the like. Further, the combination of the cap 6 and the blade 9 or the reciprocating movement of the housing 12 can be changed as appropriate. In this example, the housing 12 is reciprocated, but a mechanism for reciprocating the cleaning means 33 may be provided, and the cleaning means 33 may be reciprocated by fixing the housing 12.

  According to the above configuration, when the cap unit 8 and the blade unit 11 soiled with the droplet 13 are cleaned by the cleaning unit 33, the cap unit 8, the blade unit 11, the cleaning unit 33, and the like according to the maintenance mode and environmental conditions. Since the contact state (contact time, number of contacts, number of reciprocating movements, number of reciprocating housing movements) is controlled, the droplets 13 adhering to the cap 6 and the blade 9 can be reliably cleaned, and good recording operation can be performed after cleaning. It can be performed.

  FIG. 18 shows a modification of the cleaning means 33 shown in the embodiment of the present invention. The cleaning means 36 is arranged with a nonwoven fabric 37 as a long cleaning member of several meters or several tens of meters so as to cover the guide portion 34, and one end side of the nonwoven fabric 37 is wound around a supply roller 38 and the other end side is wound. Is fixed to the take-up roller 39, and the take-up roller 39 is rotated by a motor 40.

  In the absorber 35 of the cleaning means 33, when the liquid droplets 13 adhering to the cap 6 and the blade 9 are repeatedly absorbed, the permissible amount is eventually exceeded, and problems such as defective cleaning and defective wiping occur. In order to prevent this, it is necessary to update the absorber 35 in the area to be cleaned, and the cleaning means 36 absorbs the droplets 13 by a rollable nonwoven fabric 37. When it is determined that the cleaning means 36 has performed a predetermined number of times of preset cleaning and the liquid droplet absorption allowable amount of the nonwoven fabric 37 is full, the motor 40 is activated and the winding roller 39 is moved to the arrow shown in FIG. Rotate in the direction indicated by I, a certain amount of nonwoven fabric 37 is wound up, and a new nonwoven fabric is placed in the cleaning area. With this configuration, cleaning can be performed with the updated nonwoven fabric 37 at the next cleaning, and the cleaning performance of the cap 6 and the blade 9 can always be maintained.

The cleaning operation of the cleaning means 36 described above will be described based on the flowchart shown in FIG.
When a signal indicating that the maintenance of the recording head 1 has been completed is input to a control means (not shown) (ST21), the process proceeds to cleaning of the cap 6 and the blade 9 to which the droplets 13 are attached. After the maintenance operation is completed, the motor 24 reverses and the blade 9 rises to clean the wiping surface 9b of the blade 9 (ST22). Next, the motor 31 is actuated to move the housing 12 to the right in FIG. 18 (ST23), and the wiping surface 9b comes into contact with the vertical surface of the non-woven fabric 37 and the droplets 13 attached to the wiping surface 9b are removed. Removed by. The state in which the wiping surface 9b and the vertical surface are in contact with each other is maintained for a predetermined time, and the liquid droplet 13 is absorbed by the nonwoven fabric 37 during this time (ST24).

  Next, after the motor 24 rotates in the reverse direction and the blade 9 is lowered (ST25), the motor 31 operates to move the housing 12 further to the right (ST26), and the cap 6 and the blade 9 are in the horizontal plane of the absorber 35. When positioned below 35a, the operation of the motor 31 is stopped. After the motor 31 stops, the motor 24 reverses and the blade 9 rises (ST27), so that the upper surface 9a of the blade 9 contacts the horizontal surface of the nonwoven fabric 37. The state in which the upper surface 9a and the horizontal surface are in contact with each other is maintained for a predetermined time, and the liquid droplet 13 is absorbed by the nonwoven fabric 37 during this time (ST28). When the predetermined time has elapsed, the cleaning of the droplets 13 attached to the upper surface 9a and the wiping surface 9b of the blade 9 is completed.

  When the cleaning of the blade 9 is completed, the motor 24 rotates reversely and the blade 9 is lowered (ST29), then the motor 24 rotates forward and the cap 6 is raised (ST30), and the upper surface of the cap 6 is the horizontal surface of the nonwoven fabric 37. To touch. The state in which the upper surface and the horizontal surface of the nonwoven fabric 37 are in contact with each other is maintained for a predetermined time, and the droplet 13 is absorbed by the nonwoven fabric 37 during this time (ST31). When the predetermined time has elapsed and the droplet 13 is absorbed by the nonwoven fabric 37, the cleaning of the cap 6 is completed. When the cleaning of the cap 6 is completed, the motor 24 rotates forward and the cap 6 descends (ST32), the cap 6 is returned to the initial position, and the cleaning of the maintenance device 5 is completed. After the cleaning is completed, the motor 40 operates to rotate the winding roller 39 in the direction indicated by the arrow I in FIG. 18 (ST33), and the nonwoven fabric 37 is wound around the winding roller 39 to update the nonwoven fabric 37 in the cleaning area. Is done. In the above description, the cap 6 is cleaned after the blade 9 is cleaned. However, the cap 6 is not limited to this order, and both may be cleaned simultaneously.

  In the above-described configuration, the motor 40 operates and the winding roller 39 rotates in the direction indicated by the arrow I in FIG. 18 so that the nonwoven fabric 37 is wound around the winding roller 39 by a predetermined amount. A configuration may be adopted in which the motor 40 is operated in a state in which the non-woven fabric 37 is in contact with the cap 6 and the blade 9 to be rubbed against the non-woven fabric for cleaning.

  In the above embodiment, the housing 12 is reciprocated. However, a mechanism for reciprocating the cleaning unit 36 may be provided, and the cleaning unit 36 may be reciprocated by fixing the housing 12. Further, instead of reciprocating the cleaning means 36, the motor 40 may be moved forward and backward so that only the nonwoven fabric 37 is reciprocated. As a result, even if the refresh mode is selected and the amount of ink discharged from the recording head 1 increases and a large amount of droplets 13 adhere to the cap 6 and the blade 9, the nonwoven fabric 37 is renewed to ensure cleaning. It can be performed. A schematic diagram when the nonwoven fabric 37 is reciprocated is shown in FIG.

  FIG. 21 is a schematic view of the cleaning means when a plurality of maintenance devices are arranged. In this embodiment, two maintenance devices 5-1 and 5-2 are cleaned. The cleaning unit 41 is configured in substantially the same manner as the cleaning unit 36, and the area is set so that all the caps 6-1 and 6-2 and the blades 9-1 and 9-2 can be cleaned instead of the guide unit 34. It differs from the cleaning means 36 only in that the non-woven fabric 37 is disposed along the guide portion 42 using the enlarged guide portion 42.

  The cleaning operation by the cleaning means 41 is the same as described above, and the maintenance devices 5-1 and 5-2 are sequentially cleaned. First, cleaning is performed in the order of the wiping surface, upper surface, and cap 6-1 of the blade 9-1 of the maintenance device 5-1, and then the wiping surface, upper surface, and cap 6 of the blade 9-2 of the maintenance device 5-2. -2 cleaning is performed. The order of the cleaning operation is not limited to this. First, the wiping surfaces of the blades 9-1 and 9-2 are respectively cleaned, and then the maintenance devices 5-1 and 5-2 are moved to the guide portion 42. The upper surfaces of the blades 9-1 and 9-2 and the caps 6-1 and 6-2 may be cleaned after being positioned below. Further, the nonwoven fabric 37 may be wound after all the cleaning operations are completed or after the cleaning of one maintenance device is completed. If the absorbent capacity of the nonwoven fabric 37 does not decrease, a plurality of cleaning operations may be performed in the same region.

  FIG. 22 shows an image forming apparatus equipped with the maintenance device 55 having the cleaning means 33 described above. In FIG. 23, the image forming apparatus 43 has a line configuration in which a plurality of recording heads 1 are arranged over almost the entire width of the recording medium 44 as shown in FIG. A paper feed tray 46 on which the recording medium 44 is stacked is disposed on the right side of the apparatus main body 45 constituted by front and rear side plates and stays (not shown). The recording medium 44 is operated by the operation of the separation roller 47 and the paper feeding roller 48. Separately fed.

  A transport unit 49 that transports the recording medium 44 is disposed on the left side of the paper feed tray 46. The transport unit 49 includes a transport driving roller 50, a transport driven roller 51, an endless belt 52 spanned between the rollers 50 and 51, and the endless belt 52 has a plurality of holes. A suction fan 53 that sucks the recording medium 44 is disposed below the endless belt 52, and the left side in a state where the recording medium 44 on the endless belt 52 is attracted to the endless belt 52 by the suction force of the suction fan 53. It is conveyed to. A conveyance guide roller 54 is disposed above each of the rollers 50 and 51, and each guide roller 54 is supported by a guide member (not shown) and abuts on each of the rollers 50 and 51 by its own weight. When the conveyance driving roller 50 is rotationally driven by the operation of a driving unit (not shown), the endless belt 52 travels and the recording medium 44 is conveyed. As the endless belt 52, a belt that does not have a hole and that adsorbs the recording medium 44 by electrostatic adsorption may be used.

  Above the transport unit 49, a head unit 56 that ejects liquid droplets onto the recording medium 44 is disposed. The head unit 56 is movable in the vertical direction in the figure orthogonal to the conveyance direction of the recording medium 44, and ensures a space where the maintenance device 55 can enter below the head unit 56 during maintenance of the nozzle surface 2 of the recording head 1. It rises as much as possible.

  In the head portion 56, as shown in FIG. 23, the recording head 1 that discharges droplets is disposed so as to cover almost the entire width of the recording medium 44. The recording heads 1 are arranged in four rows (1a, 1b, 1c, 1d) in a staggered manner, and five rows (1a1 to 1a5, 1b1 to 1b5, 1c1 to 1c5, 1d1 to 1d5) are arranged. . In this embodiment, yellow (Y) and magenta (M) are assigned to the recording head 1a and the recording head 1b, and cyan (C) and black (K) are assigned to the recording head 1c and the recording head 1d, respectively. By arranging, one image line of 150 dpi is formed. The line configuration of each color is not limited to this, and the arrangement of each color is not limited to this. The configuration of the recording head 1 is not limited to this, and two recording heads may be arranged in parallel so that one color of ink is put in each recording head to improve the image resolution. In the head portion 56, branch pipes for supplying ink to the respective recording heads 1a1 to 1d5 are arranged for each color, and a sub tank is disposed above the branch pipe. Due to the water head difference between the sub tank and the head, an appropriate negative pressure is formed to hold the meniscus of the nozzle 3 of the recording head 1. An ink tank for storing ink is disposed on the upstream side of the sub tank.

  A conveyance guide unit 57 for discharging the recording medium 44 is disposed on the left side of the conveyance unit 49, and the recording medium conveyed by the conveyance guide unit 57 is a sheet discharge tray disposed on the left side thereof. 58 is discharged. The paper discharge tray 58 is provided with a pair of side fences 59 that align the recording medium 44 in the width direction and one end fence 60 that aligns the recording medium 44 in the transport direction.

  A maintenance device 55 configured substantially the same as the maintenance device 5 for maintaining the nozzle surface 2 of the recording head 1 is disposed above the transport unit 49 and to the right of the head unit 56. As shown in FIGS. 24 and 25, the maintenance device 55 has cap means 8a1 to 8d5 similar to the cap means 8 corresponding to the recording heads 1a1 to 1d5, and each cap means 8a1 to 8d5 has each recording means. Like the heads 1a1 to 1d5, five rows and four rows are arranged in a staggered pattern. Each cap unit 8a1 to 8d5 has a cap 6 that covers the nozzle surface 2 of each recording head 1a1 to 1d5. Blade means 11a1 to 11b5 similar to the blade means 11 are disposed. Each of the cap units 8a1 to 8d5 recovers the ejection performance of the recording head 1 by sucking the droplets by a suction unit (not shown) with the nozzle surface 2 sealed by the cap 6. Below the cap means 8a1 to 8a5 and 8b1 to 8b5, a flow path, a suction means, a pressure chamber, and the like (not shown) are arranged. However, these arrangements are not limited to this, and the housing 12 is designed to be compact. You may employ | adopt the structure etc. which are arrange | positioned on the outer side of a rear side board, and connect via paths, such as a tube.

  The maintenance device 55 is provided with an elevating mechanism portion 72 similar to the mechanism for moving the cap means 8 and the blade means 11 up and down in the maintenance device 5, and by operating the elevating mechanism portion 72, the cap means 8 a 1 to 8 d 5, Each blade means 11a1-11b5 is moved up and down. Similarly to the maintenance device 5, the maintenance device 55 can slide the housing 12 along the paper conveyance direction, and the housing 12 is positioned below the head portion 56 during maintenance of the recording head 1, and the housing 12 during recording operation. Retracts to the position shown in FIG.

  A cleaning means 36 is disposed above the housing 12 when it occupies the retracted position. In a state where the maintenance operation of the recording head 1 is completed and the housing 12 is located at the retracted position, the lifting mechanism 72 that moves the cap means 8a1 to 8d5 and the blade means 11a1 to 11b5 similar to the maintenance device 5 is operated. Cleaning is performed by moving the cap means 8a1 to 8d5 and the blade means 11a1 to 11b5 up and down. The cleaning means 36 is provided with a nonwoven fabric 37 for removing droplets. The nonwoven fabric 37 includes a plurality of cap means 8a1 to 8d5 and a plurality of blade means 11a1 to 11b5 of the maintenance device 55 in the main scanning direction which is the paper width direction. Corresponding to being arranged, it is configured to have a length equal to or greater than the entire area.

  In the above-described maintenance device 55, the cap means 8a1 to 8d5 are arranged corresponding to the recording heads 1a1 to 1d5, and the nozzle surface 2 is capped and moisturized. Further, during the maintenance operation, first, in order to maintain the recording heads 1a1 to 1a5, 1b1 to 1b5, the cap unit 8a1 to 8a5, 8b1 to 8b5 moves the housing 12 to a position corresponding to the recording heads 1a1 to 1a5, 1b1 to 1b5. Next, the elevating mechanism 72 is actuated to raise the cap means 8a1 to 8b5 to perform capping, and the suction operation is started. Thereafter, after the blade means 11a1 to 11b5 are raised, the housing 12 is moved in the wiping direction, and the nozzle surface 2 is wiped. Thereafter, the housing 12 moves to the cleaning means 36 side, and a cleaning operation is performed as described above. After the cleaning operation, the cap unit 8a1 to 8a5, 8b1 to 8b5 moves to a position corresponding to the recording heads 1c1 to 1c5, 1d1 to 1d5 to perform the maintenance operation of the recording heads 1c1 to 1c5, 1d1 to 1d5. The cleaning operation is performed after the maintenance operation is performed in the same manner as in FIG.

  FIG. 26 is a block diagram illustrating a control unit of the image forming apparatus 43. The control unit 61 is configured to cut off the power of the CPU 62 that controls the entire image forming apparatus, the ROM 63 that stores programs executed by the CPU 62 and other fixed data, the RAM 64 that temporarily stores image data, and the image forming apparatus 43. A non-volatile memory (NVRAM) 65 for holding data while it is being performed, an ASIC 66 for processing input / output for controlling the entire apparatus, and a host I / O for receiving data and signals with the host side F67, a head drive control unit and a head driver for driving and controlling each head, a head array unit moving drive unit for driving the head array unit, a transport belt drive unit for driving the transport belt drive motor, and a suction fan motor For driving the maintenance device moving motor 31 Maintenance device moving drive unit 68, blade / cap lifting / lowering driving unit 69 for driving the blade unit and cap unit lifting / lowering moving motor 24, cleaning device winding drive unit 70 for driving the cleaning device winding motor 40, An I / O for inputting a detection signal from an environmental sensor that detects environmental temperature and humidity is provided. Among these, the maintenance device movement drive unit 68, the blade / cap up / down movement drive unit 69, the cleaning device take-up drive unit 70, and the like constitute a control means 71.

  In the above-described embodiment, as the maintenance mode for performing the maintenance operation, the normal mode for performing normal maintenance and the refresh mode for increasing the suction amount compared to the normal mode performed in the case of not recovering in the normal mode are shown. There is also an emergency mode for emergency maintenance that is performed when the recovery is not performed even in the refresh mode and the suction amount is further increased. This emergency mode is the last means mode and cannot be performed by user operation.

  In addition to the above modes, the print head maintenance operation includes a preliminary discharge (empty discharge) mode in which ink is periodically discharged from the print head. There are several types of this preliminary discharge, a pre-printing idle discharge mode that discharges thickened ink before recording on a recording medium, a print hollow discharge mode that discharges between recording media during printing, and after printing Post-printing idle discharge mode that discharges from the decap state (the recording head is not capped by the cap) to capping, post-leaving empty discharge mode that performs discharge for printing again after recording is completed and left There is. These idle discharge modes differ depending on various conditions such as environmental conditions and standing time, and each discharges into the cap of the maintenance device. However, since the printing hollow discharge mode is printing on the recording medium, idle discharge is performed between the mediums during conveyance of the recording medium without interrupting the printing operation. That is, the ink is discharged to the belt hole opened in the conveying means and is discharged to the empty discharge receptacle provided inside the conveying means. When empty discharge is performed in the cap, the empty discharge is performed with the cap as close to the nozzle surface as possible. Further, simultaneously with the empty discharge, the ink accumulated in the cap may be sucked by the suction means disposed under the cap. it can. Therefore, since the ink hardly adheres to the cap surface covering the nozzle surface of the recording head, the cap cleaning operation is not performed in all the idle ejection modes. However, a mode in which the setting conditions can be varied may be installed so that cap cleaning can be performed even during idle ejection. Further, when the apparatus is not used for a long period of time, the idle cleaning is performed in addition to the normal mode as the uncleaning mode. In this case, since the normal mode is performed, the cap and blade cleaning operations are performed. In addition, when printing is performed continuously, the nozzle surface is contaminated by charged mist, recording medium powder, and the like, and therefore, a maintenance operation is periodically performed. At this time, it is performed in the normal mode, and the cap and the blade are cleaned. FIG. 27 shows a flowchart of the cleaning operation when each maintenance mode and each idle discharge described above are performed.

DESCRIPTION OF SYMBOLS 1 Recording head 2 Nozzle surface 5,55 Maintenance apparatus 8 Cap means 11 Blade means 13 Droplets 33, 36, 41 Cleaning means 37 Cleaning member (nonwoven fabric)
43 Image forming apparatus 44 Recording medium 71 Control means

Japanese Patent No. 3276493

Claims (8)

A recording head maintenance apparatus for discharging droplets onto a recording medium, the movable cap means covering the nozzle surface of the recording head, the movable blade means wiping the nozzle surface, the cap means, One of a plurality of maintenance modes in which the number of droplets discharged from the recording head and the amount of discharge are different from each other, and a cleaning unit that removes droplets attached to the cap unit and the blade unit in contact with the blade unit In a maintenance device having maintenance mode selection means for selecting
A maintenance apparatus comprising: a control unit that controls a contact state of the cap unit, the blade unit, and the cleaning unit according to a maintenance mode selected by the maintenance mode selection unit. The maintenance device according to claim 1,
The cap means and the blade means are capable of reciprocating in a direction contacting and separating from the cleaning means, and the control means controls a contact time between the cap means, the blade means and the cleaning means. Maintenance device. The maintenance device according to claim 1,
The cap means and the blade means are capable of reciprocating in a direction contacting and separating from the cleaning means, and the control means controls the number of times of contact between the cap means, the blade means and the cleaning means. Maintenance device. The maintenance device according to claim 1,
The cap means and the blade means are capable of reciprocating in an approaching / separating direction in which the cap means and the blade means are in contact with and away from the cleaning means, and an orthogonal direction perpendicular to the approaching / separating direction. A maintenance device for controlling the number of movements in the orthogonal direction in contact with the means. In the maintenance apparatus as described in any one of Claim 1 thru | or 4,
The maintenance device according to claim 1, wherein the control unit controls a contact state of the cap unit, the blade unit, and the cleaning unit in accordance with an environmental condition. In the maintenance apparatus as described in any one of Claim 1 thru | or 5,
The cleaning means includes a cleaning member that contacts the cap means and the blade means to remove droplets adhering to the cap means and the blade means, and the cleaning member contacts the cap means and the blade means. A maintenance device characterized in that the part can be updated.   An image forming apparatus comprising the maintenance device according to claim 1. The image forming apparatus according to claim 7.
An image forming apparatus, wherein a plurality of the recording heads are arranged in the width direction of the recording medium.

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