JP2014014951A - Liquid droplet discharge device and image formation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid droplet discharge device and an image formation device which prevent ink leakage when a liquid droplet discharge head is replaced.SOLUTION: A protection cover 10 can switch a position between a first position in which a portion of the protection cover is in a non-contact state to a nozzle hole and a second position in which the portion of the protection cover is in a contact state to the nozzle hole, and has a switching mechanism 52 which switches a position of the portion of the protection cover between the first position and the second position. A liquid droplet discharge head 20 is attached to a liquid droplet discharge device while mounting the protection cover which is in the first position. When the liquid droplet discharge head is attached to the liquid droplet discharge device, the protection cover is detached by attaching/detaching means. In detaching of the liquid droplet discharge head, the protection cover which the position is switched to the second position by the switching mechanism is attached to the liquid droplet discharge head by the attaching/detaching means, and the liquid droplet discharge head is detached from the liquid droplet discharge device.

Description

  The present invention relates to an ink jet image forming apparatus or recording apparatus such as a copying machine, a facsimile machine, a printer, a plotter, or a multifunction machine having the functions thereof, and an ink jet head mounted on such an image forming apparatus or recording apparatus. Alternatively, the present invention relates to a droplet discharge device.

  In recent years, ink jet recording apparatuses have been used for various purposes. For example, on-demand type ink jet printers have become popular in ordinary households due to lower prices and higher image quality. In a head used for an on-demand type ink jet recording apparatus or the like, a vibration plate is provided on a part of a wall of a liquid chamber filled with ink, and the vibration plate is vibrated by a piezoelectric actuator or the like to be filled with ink. There is known a method of discharging ink by increasing the pressure in the liquid chamber. There is also known a system in which a heating element that generates heat when energized is provided in a liquid chamber filled with ink, and ink is ejected by increasing the pressure in the liquid chamber by bubbles generated by the heat generated by the heating element.

  In recent years, inkjet printing apparatuses have been improved in printing speed, and a head array in which a plurality of rows of heads are arranged in a line (line type inkjet printing apparatus) is known in order to cope with the increased printing speed. It has been. In such an ink jet recording apparatus, there is known an apparatus in which each head can be replaced separately when a problem occurs in the head. In this case, in the ink jet recording apparatus, the operator can remove the pipes and joints of the head and replace the single head.

  Conventionally, for example, a protective cover that is attached after manufacturing the head is known as a part that protects a nozzle hole, a nozzle surface, a nozzle plate, and the like provided in the head. And an operator attaches this head to an apparatus main body, after removing the protective cover with which the head was equipped manually. Therefore, it is possible to protect the nozzle surface and the like provided in the head from the manufacture of the head to just before starting the use.

  However, since the removed protective cover is discarded as a waste product, it causes a problem of wasteful use of resources. Further, since the protective cover is removed immediately before the head is attached to the apparatus main body, the nozzle surface and the like are exposed when the operator attaches the head to the apparatus main body. As a result, the nozzle surface or the like may be damaged due to external factors or human error.

  On the other hand, it is known that the size of the protective cover is made as small as possible or the thickness is made thin in order to reduce the problem of waste of resources of the protective cover. However, when the size of the protective cover is reduced or the thickness is reduced, there is a problem that the nozzle surface or the like is not properly protected.

  In addition, when the head is replaced, ink may remain in the head or the head tank removed from the apparatus main body, which makes it difficult to handle the remaining ink.

  Specifically, the replacement of the head is generally performed at the place where the apparatus is installed. For this reason, when the head is replaced, there is a problem that ink remaining in the head or the head tank leaks and contaminates the apparatus and its surroundings. In the ink jet recording apparatus that employs a head array, the above-described problem becomes particularly significant.

  Therefore, the ink remaining in the head and the head tank is discharged to the waste liquid tank by a device operation such as a suction operation, and the head is replaced while the ink in the head and the head tank is almost empty. It is known to prevent ink leakage during this replacement.

  However, the limited capacity of the waste liquid tank is excessively used by the remaining ink. Therefore, it is necessary to secure the capacity of the waste liquid tank for this amount. As a result, there arises a problem that the apparatus becomes large.

  Next, a conventional protective cover (head cover) will be described in detail below with reference to FIGS. 8 (a) and 8 (b). The head Md (Md is an abbreviation of “module”, and the head Md is also referred to as a head unit) 40 in which the head 20 and the tank 30 are replaced as a unit, as shown in FIG. After manufacture, the head cover 210 is attached to the tip of the head portion. By mounting the head cover 210, the nozzle surface 22, nozzle holes (not shown), and the like are protected from damage due to external force, contact with other articles, and the like.

  A plurality of heads Md40 are arranged in parallel to the base unit 50 or the carriage as shown in FIG. When the head Md40 is mounted on the base unit 50 or the carriage, the head cover 210 is removed in advance, and the nozzle surface 22 and the nozzle holes are exposed. Further, the removed head cover 210 is discarded without being reused.

  Further, when a problem occurs in the head Md40 attached to the base unit 50 or the carriage, the head Md40 is replaced. In particular, in a line-type head in which a large number of heads Md40 are arranged on the base portion 50, it is difficult to replace the heads in units of the line-type heads. Therefore, generally, the head Md40 to be exchanged can be exchanged in a minimum unit by removing a joint with an ink supply path (not shown) on the apparatus.

  Here, when the head Md40 is replaced, in order to prevent the ink remaining in the head and the head tank from leaking, this ink removal or leakage preventing means is required. As this ink removal or leakage prevention means, for example, it is known that the waste liquid treatment is performed by suction of the apparatus, and the head Md40 is replaced after the ink in the head Md becomes almost empty.

  However, even in such a means, there is a possibility that ink that has not been completely removed remains in the head Md40 due to adhesion in the vicinity of the nozzle. Therefore, when the head Md40 is replaced in an apparatus having such means, there is a risk of ink leaking or dripping from the nozzle hole, and sufficient attention must be paid to contamination of the inside and outside of the apparatus by this ink. . Further, since the residual ink is discharged to the waste liquid tank in the apparatus by the suction of the apparatus, it is necessary to secure a sufficient capacity of the waste liquid tank for the residual ink.

  Therefore, an apparatus that employs a head protection member that solves the above-described problems is known (see, for example, Patent Documents 1 to 4).

  The line-type head described in Patent Document 1 includes a main body, an ink head, and a cap, and the line-type head can be attached to and detached from the main body while the cap is attached to the line-type ink head. As a result, it is possible to keep the cap on the line type head at all times except during normal operation, the above-mentioned problem of scratching, the problem of wasteful use of resources, and the problem that the nozzle surface is not properly protected, It is possible to solve the problem of contamination of the apparatus and its surroundings due to ink leakage and the problem of the apparatus becoming larger.

  However, if the cap is to have a specific function such as suction as a maintenance function of the main body, it is necessary to provide the cap with a part that exhibits a sealing function against suction pressure, for example. For this reason, the cap becomes very expensive, and the cost cannot be reduced.

The ink jet recording apparatus described in Patent Document 2 includes a protective cap unit and a cap opening / closing mechanism, and performs an opening / closing operation of the protective cap unit using a droplet discharge head attaching / detaching operation to expose and cover the nozzle surface. . As a result, it is possible to solve the above-mentioned problem of wasteful use of resources, the problem that the nozzle surface or the like is not properly protected, and the problem that the apparatus is enlarged.

  However, this cap opening / closing mechanism is a rotating mechanism via an arm, and the protective cap means opens and closes while rubbing the nozzle surface. In this ink jet recording apparatus, the protective cap means is removed before the droplet discharge head is attached to the carriage. Therefore, after all, the above-mentioned problem of scratching and the problem of contaminating the device and its surroundings due to ink leakage are not solved.

  The head mechanism described in Patent Document 3 includes a fitting mechanism in a protective cap portion, and a droplet discharge head to which the protective cap portion is attached is attached to the apparatus main body. Therefore, it is possible to solve the above-mentioned problem of scratches, the problem of wasteful use of resources, the problem that the nozzle surface is not properly protected, the problem of contaminating the device and its surroundings due to ink leakage, and the problem of increasing the size of the device. .

  However, if the cap is to have a specific function such as suction as a maintenance function of the main body, it is necessary to provide the cap with a part that exhibits a sealing function against suction pressure, for example. For this reason, the cap becomes very expensive, and the cost cannot be reduced.

  The ink jet recording apparatus described in Patent Document 4 includes a guide rail, a carriage that horizontally moves on the guide rail, an ink cartridge that is detachably attached to the carriage, a protective cover, and a protective cover lock mechanism. In this case, the nozzle of the ink cartridge can be protected. Therefore, it is possible to solve the above-mentioned problem of wasteful use of resources, the problem that the nozzle surface or the like is not properly protected, and the problem that the apparatus is enlarged.

  However, since the ink cover having the nozzle is slid to attach the protective cover to the nozzle, friction occurs between the nozzle surface and the protective cover. Therefore, after all, the above-mentioned problem of scratching and the problem of contaminating the device and its surroundings due to ink leakage are not solved.

  SUMMARY An advantage of some aspects of the invention is to provide a droplet discharge device and an image forming apparatus that solve the above-described problems and prevent ink leakage when the droplet discharge head is replaced.

In order to solve the above-described problem, a droplet discharge device according to a first aspect of the present invention includes:
A droplet discharge device having a detachable droplet discharge head,
The droplet discharge head comprising at least one nozzle hole for discharging a liquid;
A droplet discharge device having a protective cover covering the nozzle hole,
An attachment / detachment means capable of attaching / detaching the protective cover from the droplet discharge head;
The protective cover can be repositioned between a first position where a part of the protective cover is not in contact with the nozzle hole and a second position where the protective cover is in contact.
A switching mechanism for switching the position of the part of the protective cover between the first position and the second position;
The droplet discharge head is attached to a droplet discharge device with the protective cover in the first position attached.
When the droplet discharge head is attached to the droplet discharge device, the protective cover is removed by the attaching / detaching means,
When removing the droplet discharge head, the protective cover switched to the second position by the switching mechanism is attached to the droplet discharge head by the attaching / detaching means, and the liquid discharge head is removed from the droplet discharge device. It is characterized by that.

  According to the present invention, it is possible to provide a droplet discharge device and an image forming apparatus that prevent ink leakage when replacing a droplet discharge head.

1 is a perspective view showing an ink jet recording apparatus which is an example of an image forming apparatus according to the present invention. FIG. 2 is a schematic side view showing an outline of the image forming apparatus shown in FIG. 1. FIG. 2 is a schematic plan view illustrating an overview of the image forming apparatus illustrated in FIG. 1. FIG. 4A is a cross-sectional view showing a head cover of the head Md of the image forming apparatus shown in FIG. 1, FIG. 4A is a cross-sectional view showing a state where the concave portion is not deformed, and FIG. It is sectional drawing which shows the state which is carrying out. FIG. 5 is a cross-sectional view illustrating a state in which the head cover of the head Md of the image forming apparatus illustrated in FIG. 1 is mounted on the head Md, and FIG. 5A is a cross-sectional view illustrating a state in which the concave portion is not deformed. b) is a cross-sectional view showing a state in which the concave portion is deformed. FIG. 2 is a cross-sectional view illustrating a mounting operation of the head Md of the image forming apparatus illustrated in FIG. 1, and a cross-sectional view illustrating a state before the head Md is attached. FIG. 2 is a cross-sectional view illustrating the mounting operation of the head Md of the image forming apparatus illustrated in FIG. 1, and is a cross-sectional view illustrating a state in which the head cover is not removed after the head Md is mounted. FIG. 2 is a cross-sectional view illustrating the mounting operation of the head Md of the image forming apparatus illustrated in FIG. 1, and is a cross-sectional view illustrating a state in which the head cover is removed after the head Md is mounted. FIG. 7 is a cross-sectional view for explaining the operation of removing the head Md of the image forming apparatus shown in FIG. 1, and FIG. 7A is a cross-sectional view showing a state in which the head cover is removed before the head Md is removed. 7B is a cross-sectional view showing a state in which the head cover is mounted before the head Md is removed, and FIG. 7C is a cross-sectional view showing a state after the head Md is removed. FIG. 8A is a cross-sectional view illustrating a conventional head cover, FIG. 8A is a cross-sectional view illustrating a state in which the head cover is attached to the head Md, and FIG. 8B is a cross-sectional view illustrating an attaching operation of the head Md. . FIGS. 9A and 9B are cross-sectional views for explaining the engaging / disengaging operation of the head cover when the head Md is attached, FIG. 9A is a cross-sectional view showing a state in which the head cover is attached to the head Md, and FIG. It is sectional drawing which shows the state removed from the head Md. FIG. 10A is a cross-sectional view for explaining the operation of mounting the head cover when the head Md is removed, FIG. 10A is a cross-sectional view showing a state in which the head cover is removed from the head Md, and FIG. FIG. 10C is a cross-sectional view showing a state after being mounted on the head Md, and FIG. 10C is a cross-sectional view showing a state after the head Md is removed.

  Hereinafter, an embodiment according to the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing an ink jet recording apparatus which is an example of an image forming apparatus according to the present invention.

  As shown in FIG. 1, the inkjet recording apparatus 100 according to the present embodiment is detachably mounted on the apparatus main body 101, a paper feed tray 102 for loading paper loaded on the apparatus main body 101, and the apparatus main body 101. And a paper discharge tray 103 for stocking the paper on which the image is formed. Further, a cartridge loading unit 104 for loading an ink cartridge is provided on one side of the front surface of the apparatus main body 101 so as to be adjacent to the paper supply / discharge tray unit. On the upper surface of the cartridge loading unit 104, an operation / display unit 105 in which operation buttons, a display, and the like are arranged is provided.

  Four ink cartridges 110 are set in the cartridge loading unit 104. Each ink cartridge 110 contains recording liquid (ink), which is a color material having a different color, such as black (K), cyan (C), magenta (M), and yellow (Y) color inks. These ink cartridges 110 can be inserted and loaded from the front side to the rear side of the apparatus main body 101. The ink cartridges 110 are configured to be loaded side by side in the vertical direction. A front cover (cartridge cover) 106 that is opened when the ink cartridge 110 is attached or detached is provided on the front side of the cartridge loading unit 104 so as to be openable and closable.

  The operation / display unit 105 displays four remaining amounts for displaying that the remaining amount of each color ink cartridge is near-end and end at an arrangement position corresponding to the attachment position (arrangement position) of each color ink cartridge 110. A display unit 111 is arranged. Further, the operation / display unit 105 includes a power button 112, a paper feed / print restart button 113, and a cancel button 114.

  Next, the mechanism part of the ink jet recording apparatus will be described with reference to FIGS. 2 is a schematic side view showing an outline of the image forming apparatus shown in FIG. 1, and FIG. 3 is a schematic plan view showing an outline of the image forming apparatus shown in FIG.

  In the mechanism part of the ink jet recording apparatus, the carriage (base part) 50 is slidable in the main scanning direction by a guide rod 131 and a stay 132 which are guide members horizontally mounted on the left and right side plates 121A and 121B constituting the frame 121. 3 is moved and scanned in the direction indicated by the arrow (carriage main scanning direction) in FIG. 3 via a timing belt by a main scanning motor (not shown). The ink jet recording apparatus 100 according to this embodiment is a serial type image forming apparatus that includes a droplet discharge device 60 that discharges ink while moving to the droplet discharge head 20 and forms an image.

  As described above, the carriage 50 includes a plurality of heads that are four droplet ejection heads 20 that eject ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (Bk). The ink discharge ports are arranged in a direction crossing the main scanning direction, and are mounted with the ink droplet discharge direction facing downward.

  The head constituting the droplet discharge head 20 includes a piezoelectric actuator such as a piezoelectric element, a thermal actuator that uses a phase change caused by liquid film boiling using an electrothermal transducer such as a heating resistor, and a metal phase change caused by a temperature change. A shape memory alloy actuator using an electrostatic force, an electrostatic actuator using an electrostatic force, and the like provided as pressure generating means for generating a pressure for discharging a droplet can be used.

  A driver IC is mounted on the droplet discharge head 20 and is connected to a control unit (not shown) via a harness (flexible print cable) 122. The carriage 50 is mounted with a head tank (tank) 30 for each color for supplying ink of each color to the droplet discharge head 20. As described above, each color tank 30 is replenished and supplied to each color tank 30 from each color ink cartridge 110 mounted in the cartridge loading unit 104 via each color ink supply path 32. The cartridge loading unit 104 is provided with a supply pump unit 124 for feeding the ink in the ink cartridge 110, and the ink supply path 32 is connected to the rear plate 121C constituting the frame 121 in the middle of turning. It is held by a stop member 125.

  On the other hand, as a paper feeding unit for feeding the paper 142 stacked on the paper stacking unit (pressure plate) 141 of the paper feeding tray 102, a half-moon roller (feeding) that separates and feeds the paper 142 from the paper stacking unit 141 one by one. A separation pad 144 made of a material having a large friction coefficient is provided opposite to the sheet roller 143 and the sheet feeding roller 143, and the separation pad 144 is biased toward the sheet feeding roller 143 side.

  In order to feed the sheet 142 fed from the sheet feeding unit to the lower side of the droplet discharge head 20, a guide member 145 for guiding the sheet 142, a counter roller 146, a transport guide member 147, and a tip addition A pressing member 148 having a pressure roller 149, and a conveying belt 151 that is a conveying means for electrostatically attracting the fed paper 142 and conveying it at a position facing the droplet discharge head 20. .

  The conveyor belt 151 is an endless belt, and is configured to wrap around the conveyor roller 152 and the tension roller 153 and circulate in the belt conveyance direction (sub-scanning direction). Further, a charging roller 156 that is a charging unit for charging the surface of the transport belt 151 is provided. The charging roller 156 is disposed so as to come into contact with the surface layer of the conveyor belt 151 and to rotate following the rotation of the conveyor belt 151. Further, a guide member 157 is disposed on the back side of the conveyor belt 151 so as to correspond to a printing region by the droplet discharge head 20.

  The conveyance belt 151 rotates in the belt conveyance direction of FIG. 3 when the conveyance roller 152 is rotationally driven via a timing belt by a sub-scanning motor (not shown). Further, as a paper discharge unit for discharging the paper 142 recorded by the droplet discharge head 20, a separation claw 161 for separating the paper 142 from the transport belt 151, a paper discharge roller 162 and a paper discharge roller 163, And a paper discharge tray 103 below the paper discharge roller 162.

  A double-sided unit 171 is detachably attached to the back surface of the apparatus main body 101. The duplex unit 171 takes in the paper 142 returned by the reverse rotation of the transport belt 151, reverses it, and feeds it again between the counter roller 146 and the transport belt 151. The upper surface of the duplex unit 171 is a manual feed tray 172.

  Further, as shown in FIG. 3, a maintenance / recovery mechanism 181 including a recovery means for maintaining and recovering the state of the nozzles of the droplet discharge head 20 is disposed in the non-printing area on one side of the carriage 50 in the scanning direction. doing.

  The maintenance / recovery mechanism 181 includes an eccentric cam mechanism (not shown) 52, a cover delivery guide 51, and a wiper blade 183 that is a blade member for wiping the nozzle surface.

  Then, the waste liquid of the recording liquid generated by the maintenance / recovery operation by the maintenance / recovery mechanism 181, the ink removed by the wiper blade 183, and the ink ejected to the idle ejection receptacle 184 are discharged and stored in a waste liquid tank (not shown).

  Further, as shown in FIG. 3, in the non-printing area opposite to the maintenance / recovery mechanism 181, idle discharge is performed to discharge liquid droplets that do not contribute to recording in order to discharge the recording liquid thickened during recording or the like. An empty discharge receiver 188 for receiving the droplets at the time is disposed, and the empty discharge receiver 188 is provided with an opening 189 along the nozzle row direction of the droplet discharge head 20.

  In the ink jet recording apparatus 100 of this embodiment configured as described above, the paper 142 is separated and fed one by one from the paper feed tray 102, and the paper 142 fed substantially vertically upward is guided by the guide 145 and conveyed. The belt 151 and the counter roller 146 are sandwiched and conveyed, and the leading end is guided by the conveying guide 137 and pressed against the conveying belt 151 by the leading end pressure roller 149, and the conveying direction is changed by approximately 90 °.

  Then, the sheet 142 is attracted to the conveyance belt 151, and the sheet 142 is conveyed in the sub-scanning direction by the circular movement of the conveyance belt 151. Then, the droplet ejection head 20 is driven in accordance with the image signal while moving the carriage 50 in the main scanning direction based on main scanning position information by a linear encoder (not shown), whereby the stopped paper 142 is applied. Ink droplets are ejected to record one line, and after a predetermined amount of paper 142 is conveyed, the next line is recorded. Upon receiving a recording end signal or a signal that the trailing edge of the sheet 142 has reached the recording area, the recording operation is terminated and the sheet 142 is discharged onto the discharge tray 103.

  Next, a protective cover (head cover) which is a characteristic configuration of the present invention will be described below with reference to FIGS. 4 (a) and 4 (b).

  As shown in FIG. 4A, the head cover 10 includes a side wall 11 and a concave portion 12 having a concave shape, and an absorbent material 15 is provided on the bottom of the concave portion 12. A minute communication hole 13 that communicates the inside and outside of the head cover 10 is formed in the bottom surface of the recess 12.

  As shown in FIG. 4B, the recess 12 has a folded portion 14 over the entire periphery of the recess 12 near the side wall 11. The folding portion 14 is folded by applying a predetermined external force to the bottom surface of the recess 12. And the bottom of the recessed part 12 raises by folding. Note that it is desirable to use an elastic body such as silicon for the recess 12. Moreover, it is good also as a structure which replaces with the folding part 14 and arrange | positions the elastic body which has a stretching property to the perimeter of the side wall 11 of the recessed part 12, and the stopper which can hold | maintain the position of the recessed part 12 is provided.

  Next, a state in which the head cover is attached to the droplet discharge head will be described below with reference to FIGS. 5 (a) and 5 (b).

  FIG. 5A is a cross-sectional view showing a state in which the head cover 10 is mounted on the replacement (new) head Md40. The head cover 10 is attached to a head Md (head unit) 40 including a tank 30 and a head (droplet discharge head) 20 in a first position where the folding portion 14 is not folded. In this state, the nozzle surface 22 of the head 20 and the nozzle hole thereof do not contact the side wall 11 and the absorbent material 15 of the head cover 10. Here, it is necessary to pay close attention to the nozzle surface 22 on the surface of the nozzle plate 21 provided in the head Md40 in order to prevent the ink discharge function to the maximum extent to prevent scratches and adhesion of foreign substances. Further, in recent years when the density of nozzle holes is increasing, since the diameter of the nozzle holes is small, the nozzle surface 22 and the nozzle holes are particularly affected by scratches and foreign matter adhering to them. For this reason, by mounting the head cover 10 of the present embodiment, the influence of external factors can be prevented, and the state where the nozzle surface is not in contact with any member in the cover can be maintained, and the influence of internal factors can also be prevented. it can.

  FIG. 5B is a cross-sectional view showing a state in which the head cover 10 is attached to the used head Md40. The head cover 10 is attached to the head Md40 including the tank 30 and the head 20 in a state where the folding portion 14 is folded. Specifically, an external force is applied to the concave portion 12 by an eccentric cam mechanism (switching mechanism) 52, which will be described later, so that the folding portion 14 is folded and the bottom of the concave portion 12 is raised to the head Md40 in the second position. Has been. The absorbent 15 provided inside the recess 12 is in close contact with the nozzle surface 22 and its nozzle hole.

  In addition, the used head Md40 is in an open state in which the joint portion (opening / closing portion) 31 above the tank 30 is separated from the ink jet recording apparatus. Further, when absorbing ink, the air trapped in the head cover 10 is released to the outside through the communication hole 13 provided in the bottom surface of the recess 12 to promote the movement of the residual ink 35, and the ink is removed. The absorbent 15 can be absorbed quickly. Further, since the communication hole 13 is provided on the bottom surface of the recess 12 via the absorbent material 15, the ink is absorbed by the absorbent material 15 and the ink does not leak from the communication hole.

  Further, due to the surface tension of the ink remaining in the contour portion of the nozzle hole, the residual ink 35 remaining without dripping from the nozzle hole comes into contact with the surface of the ink remaining in the contour portion of the nozzle hole. As a result, the surface tension is broken and absorbed by the absorbent 15. That is, a so-called meniscus formed in the nozzle hole is broken, and the residual ink 35 can be actively absorbed by the absorbent material 15. Here, a sponge is used as the absorbent material 15, but instead of this sponge, for example, a highly permeable member may be used.

  Further, the absorbent material 15 has a volume capable of absorbing the remaining ink 35, and all of the ink flowing out from each nozzle hole and ink path is absorbed by the absorbent material 15. Therefore, the ink does not remain in the nozzle holes and the ink path 25, no ink leakage occurs, and the apparatus and its surroundings are not contaminated. As a result, the operator can easily perform the replacement work of the head Md40 without worrying about ink leakage.

  The absorbent material 15 may be in close contact with the nozzle hole, and the folded convex portion 14a formed in a convex shape by folding the concave portion 12 may be in close contact with the nozzle surface 22 over the entire circumference. As a result, the sealing property between the head cover 10 and the head 20 is improved, and ink leakage can be more reliably prevented.

  Further, instead of the communication hole 15 at the bottom of the concave portion 12 of the head cover, an air release valve may be employed to expand communication with the atmosphere. When absorbing ink, the movement of the remaining ink 35 is promoted by opening the air release valve, and the ink can be absorbed quickly by the absorbent material 15. In addition, after the residual ink 35 has moved to the absorbent material 15, it is possible to reliably prevent ink leakage by closing the air release valve.

  Hereinafter, the mounting operation of the head Md in the image forming apparatus according to the present embodiment will be described with reference to FIG.

  As shown in FIG. 3, a base portion (carriage) that is slidably held in a main scanning direction by a guide rod 131 and a stay 132, which are guide members horizontally mounted on left and right side plates 121A and 121B constituting the frame 121. As shown in FIG. 6A, the shape of the head 50 is adjusted so that the head Md40 can be attached with the head cover 10 still attached. The head Md40 to which the head cover 10 is attached is attached to the base unit 50 and mounted on the ink jet recording apparatus 100 (not shown) with the absorbent material 15 remaining in the first position where it does not contact the nozzle surface 22. The

  The cover delivery guide 51 is installed on the ink jet recording apparatus side below the head Md40 attached to the ink jet recording apparatus 100. The cover delivery guide 51 is raised relative to the head Md40 by known lifting means (not shown). And as shown in FIG.6 (b), when the cover delivery guide 51 raises, the cover cover 51 hold | maintains the head cover 10 by the attachment / detachment means mentioned later.

  Then, as shown in FIG. 6C, the cover delivery guide 51 is lowered while holding the head cover 10. In this way, the head cover 10 is removed from the new head Md40.

  Therefore, the head cover 10 is not removed immediately before the head Md40 is attached to the ink jet recording apparatus 100, and the operator can easily perform the replacement operation of the head Md40 without worrying about damage to the nozzle surface or the like. it can.

  As shown in FIG. 6A, the eccentric cam mechanism 52 is installed on the ink jet recording apparatus side below the head Md40 with the head Md40 attached to the ink jet recording apparatus 100.

  The eccentric cam mechanism 52 can rotate 180 ° at the same time as the cover delivery guide 51 rises, and can accommodate the head Md40 in the cover delivery guide 51 in the first position where the recess 12 of the head cover 10 is not deformed.

  6 (b), the cover delivery guide 51 holds the head cover 10, the shape of the recess 12 does not change, and the absorbent material 15 does not contact the nozzle surface 22 or its nozzle hole. It is like that.

  Here, the eccentric cam mechanism 52 rotates 180 ° with the cover delivery guide 51 holding the head cover 10, thereby applying an external force to the recess 12 to closely contact the absorbent material 15 with the nozzle surface 22 and its nozzle hole. It can be pushed up to the second position. And the shape of the recessed part 12 changes and the absorber 15 closely_contact | adheres to the nozzle surface 22. FIG.

  Then, the cover delivery guide 51 is lowered while holding the head cover 10 as shown in FIG. At that time, the eccentric cam mechanism 52 rotates 180 ° and pushes up the bottom of the recess 12. In addition, the recessed part 12 formed with elastic bodies, such as a silicon | silicone, deform | transforms in the folding part 14, and can maintain the deformed state. Further, the concave portion 12 may be entirely an elastic body or a part thereof may be an elastic body.

  Further, the head cover 10 removed by the cover delivery guide 51 is retracted as it is to the maintenance / recovery mechanism 181 (not shown) in the ink jet recording apparatus until the next replacement of the head Md40. Therefore, the head cover 10 is not discarded, and the head cover 10 when the head Md40 is attached to the inkjet recording apparatus 100 can be used again when the head Md40 is replaced.

  Next, in the image forming apparatus according to the present embodiment, the operation of removing the head Md will be described below with reference to FIG. As shown in FIG. 7A, the head cover 10 maintains a deformed state in the ink jet recording apparatus. The tank 30 and the head 20 have residual ink 35.

  Then, as shown in FIG. 7B, the cover delivery guide 51 moves in a direction approaching the head Md40 by the raising operation of the cover delivery guide 51. At this time, since the concave portion 12 of the head cover 10 is pushed up, the absorbent material 15 comes into close contact with the nozzle hole or the like at the same time when the head cover 10 is mounted on the head Md40. In this state, the ink supply path 32 in the ink jet recording apparatus is removed from the joint portion 31, and the upper portion of the tank 30 is opened, so that the residual ink 35 moves to the absorbent material 15.

  After the remaining ink 35 is absorbed by the absorbent material 15, the cover delivery guide 51 releases the holding of the head cover 10 by an attaching / detaching means described later, and descends as shown in FIG. The head Md40 is in a state where the head cover 10 is attached. Then, the used head Md40 is taken out from the ink jet recording apparatus. The eccentric cam mechanism 52 does not rotate during the removal operation of the head Md. However, the eccentric cam mechanism 52 does not rotate during the attachment operation of the head Md40, and the eccentric cam mechanism does not rotate during the removal operation of the head Md40. It is good also as a structure which 52 rotates. Specifically, the eccentric cam mechanism 52 does not rotate when the cover delivery guide 51 of FIG. 6C is lowered, and the head cover 10 is in the ink jet recording apparatus 100 in the first position where the recess 12 is not deformed. During the operation of removing the head Md, the head cover 10 shown in FIG. 7B is attached to the head Md even before the head cover 10 shown in FIG. 7A is attached to the head Md. Alternatively, the eccentric cam mechanism 52 may be rotated by 180 °, and the concave portion may be pressed against the head Md in the second position.

  6 and 7 show only the head Md40 to be replaced, but the cover delivery guide 51 may be raised and lowered only for the head Md40 to be replaced, or a plurality of heads A mechanism that simultaneously performs Md may be used. In general, the latter is preferable because the raising mechanism can be simply formed. In this case, the control of holding the head cover 10 of the cover delivery guide 51 is performed for each cover delivery guide 51.

  Then, the replacement of the head Md40 is completed by attaching a new head Md40 to the ink jet recording apparatus. Thus, the remaining ink 35 can be moved to the absorbent material 15 with the head Md40 attached to the ink jet recording apparatus, and the replacement work is facilitated.

  Next, the attaching / detaching means that enables the head cover 10 to be attached to and detached from the head 20 will be described in detail below with reference to FIGS. The illustration of the recess 12 is omitted for convenience of explanation.

  As shown in FIG. 9A, the head 20 has a first engagement groove 20 a and a second engagement groove 20 b formed in order on the side surface near the tip of the head 20. And between the 1st engagement groove | channel 20a and the 2nd engagement groove | channel 20b, it has the inclination part inclined in the direction which the diameter of the head 20 spreads from the front-end | tip of the head 20. As shown in FIG.

  The side wall 11 of the head cover 10 has a side wall claw 11 a that protrudes inside the opening side of the head cover 10. Further, the side wall 11 has a third engagement groove 11 b on the outside of the head cover 10. Further, the delivery guide 51 has a guide claw 51a that protrudes inward near the tip end on the head 20 side.

  And the side wall nail | claw 11a and the 1st engagement groove | channel 20a are engaged, and let the allowance of the nail | claw be A. Further, the guide claw 51a and the third engagement groove 11b are engaged with each other. Further, as shown in FIG. 10B, the side wall claw 11a and the second engagement groove 20b are engaged with each other, and the cost of the claw is C. At this time, the relationship of cost A is less than cost B and cost C For this reason, the catching force of each nail increases in accordance with the catching amount of the nail.

  Next, the engagement / disengagement operation of the head cover when the head Md is attached will be described below with reference to FIG. The head cover 10 is mounted on a new head Md40 with the side wall claws 11a engaged with the first engagement grooves 20a. Then, when the head Md40 is attached to the base portion 50, the delivery guide 51 moves up. And the guide nail | claw 51a with which the delivery guide 51 is equipped engages with the 3rd engagement groove | channel 11b. Then, as shown in FIG. 9B, the delivery guide 51 performs a lowering operation.

  At this time, as shown in FIG. 9 (a), since the relationship of the allowance A <the allowance B is satisfied, the catching force of the guide claw 51a is larger than the catching force of the side wall claw 11a. Therefore, as shown in FIG. 9B, the delivery guide 51 moves downward while holding the head cover 10 with the guide claws 51a.

  Next, the mounting operation of the head cover when the head Md is removed will be described below with reference to FIG. As shown in FIG. 10A, the head cover 10 is held by guide claws 51 a provided in the delivery guide 51. Then, when the head Md40 is removed, the delivery guide 51 moves upward together with the head cover 10 held by the guide claws 51a as shown in FIG. 10B, and the side wall claws 11a are in the second engagement. It rises until it engages with the mating groove 20b.

  At this time, the side wall claw 11a is easily engaged with the second engagement groove 20b because the inclined portion between the first engagement groove 20a and the second engagement groove 20b exhibits a guide function. It has become. Then, the head Md40 is removed from the base portion 50 as shown in FIG. At this time, as shown in FIG. 10 (b), since the relationship of the allowance B <the allowance C is satisfied, the catching force of the side wall claws 11a is larger than the catching force of the guide claws 51a. Therefore, the head Md40 is removed while the side wall claw 11a of the head cover 10 holds the head 20, as shown in FIG.

  Next, the operation of the image forming apparatus according to this embodiment will be described. In the image forming apparatus according to the present embodiment, the head cover 10 is attached to the ink jet recording apparatus 100 in the first position in which the head cover 10 is mounted in a non-contact manner on the nozzle holes or the like. The head cover 10 has the head Md40 attached to the ink jet recording apparatus 100. When attached, it is removed via the attaching / detaching means. The head Md40 is detached from the ink jet recording apparatus 100 via the attaching / detaching means in the second position in which the head cover 10 is attached in contact with the nozzle hole by the cam mechanism 52.

  Therefore, the head cover 10 is not removed when the head Md 40 is attached to the inkjet recording apparatus 100 and is not discarded as a waste product. The head cover 10 removed from the head Md40 in the ink jet recording apparatus can be used again as the head cover 10 of the head Md40 when the used head Md40 is removed from the ink jet recording apparatus 100. The head cover 10 can also be expected to be used as recycled parts or recycled resources. This solves the problem of wasted resources.

  Further, the head cover 10 is not removed immediately before the head Md40 is attached to the ink jet recording apparatus 100. Therefore, the problem of the occurrence of scratches on the nozzle surface due to external factors or human error is also solved.

  Further, since the head cover 10 does not cause a problem of wasteful use of resources, there is no problem that the size of the head cover 10 is reduced and the nozzle surface is not properly protected.

  Further, when the head Md40 is removed from the ink jet recording apparatus 100, the head cover 10 is attached to the head Md40, so that ink leakage does not occur when the head Md40 is replaced, and the apparatus and its surroundings are contaminated. Is also resolved. This problem can be solved even in an apparatus that employs a head array in which a plurality of heads are arranged in a line.

  Further, the head cover 10 can be maintained at the first position in a non-contact state and the second position in a contact state with respect to the nozzle holes. Therefore, when the unused head Md40 is attached to the ink jet recording apparatus 100, the head cover 10 maintains the state of the first position that is not in contact with the nozzle hole, and the nozzle hole maintains a state of not contacting any member or the like. it can. As a result, the head cover 10 can reliably prevent the nozzle surface and the like from being damaged not only in a static state but also in a dynamic state in which vibration occurs due to an external factor or the like.

  Further, when the used head Md40 is removed from the ink jet recording apparatus 100, the head cover 10 maintains the second position in contact with the nozzle holes, and the nozzle holes are directly closed by the head cover 10. Can be maintained. As a result, the head cover 10 can prevent ink leakage not only in the case where the head Md40 is in a static state but also in a dynamic state in which vibration occurs due to external factors such as carrying and movement.

  Further, the eccentric cam mechanism 52 can press the concave portion 12 of the head cover 10 when the head cover 10 is attached to the head Md 40 in the ink jet recording apparatus, and can bring the concave portion 12 into close contact with the nozzle hole. Therefore, when the used head Md40 is removed from the ink jet recording apparatus 100, ink leakage does not occur from the used head Md40 to which the head cover 10 is attached. As a result, the inkjet recording apparatus 100 and the periphery of the inkjet recording apparatus 100 are not contaminated with ink, and the operator can remove the used head Md40 from the inkjet recording apparatus 100 without worrying about ink leakage. .

  Moreover, the recessed part 12 is an elastic body, and the head cover 10 is urged | biased with respect to a nozzle hole with the elastic force of an elastic body. Therefore, when the used head Md40 is removed from the inkjet recording apparatus 100, the head cover 10 can maintain a pressure contact state with respect to the nozzle holes. As a result, the head Md 40 to which the head cover 10 is attached can reliably prevent ink leakage not only in a static state but also in a dynamic state in which vibration is generated due to an external factor or the like. In addition, the recessed part 12 is not limited to this aspect, For example, one part may be an elastic body.

  Since the head cover 10 includes the absorbent material 15, the absorbent material 15 can be in close contact with the nozzle surface 22 and the nozzle hole. Therefore, a so-called meniscus formed by the interaction between the nozzle hole and ink path 25 and the ink is destroyed, and the remaining ink can be actively absorbed by the absorbent material 15. As a result, when the head Md40 is removed from the ink jet recording apparatus 100, ink leakage does not occur, and the ink jet recording apparatus 100 and the periphery of the ink jet recording apparatus 100 are not contaminated with ink. Further, the operator can remove the used head Md40 from the ink jet recording apparatus 100 without worrying about ink leakage.

  Further, the absorbing material 15 can absorb the residual ink remaining in the head Md40 including the head tank. For this reason, the waste liquid tank can be reduced in size without using the waste liquid tank for the treatment of the residual ink. As a result, the size of the device itself can be reduced.

  Further, since the head cover 10 has the absorbent material 15, the head cover does not have a specific function such as suction. Therefore, the head cover 10 does not require a sealing function and is not very expensive, so that the cost can be reduced.

  Further, the head cover 10 has a communication hole 13 that allows communication between the inside and the outside of the head cover 10, and the joint portion 31 provided above the tank 30 can be opened. Therefore, when ink is absorbed, the movement of the remaining ink 35 can be promoted through the communication hole 13 provided on the bottom surface of the recess 12, and the ink can be absorbed quickly by the absorber 15. Further, since the communication hole 13 is provided on the bottom surface of the recess 12 via the absorbent material 15, the ink is absorbed by the absorbent material 15 and the ink does not leak from the communication hole.

  Further, instead of the communication hole 15 at the bottom of the concave portion 12 of the head cover, an air release valve may be employed to expand communication with the atmosphere. When absorbing ink, the movement of the remaining ink 35 is promoted by opening the air release valve, and the ink can be absorbed quickly by the absorbent material 15. In addition, after the residual ink 35 has moved to the absorbent material 15, it is possible to reliably prevent ink leakage by closing the air release valve.

  In addition, since the head cover 10 is attached to the head Md40 when the head Md40 is manufactured, the nozzle can be protected from the time when the head Md40 is manufactured until the user attaches the head Md40 to the inkjet recording apparatus 100.

  When the image forming apparatus includes the droplet discharge device according to any one of claims 1 to 6, it is possible to provide an image forming apparatus that prevents ink leakage and protects the nozzle holes when the head Md40 is replaced. .

  In addition, after the head cover 10 is attached to the head Md40, the head Md40 may be removed from the ink jet apparatus 100 before the ink is moved to the absorbent material 15 in the ink jet apparatus. Even with such a configuration, the same effects as described above can be exhibited. Specifically, before the head Md40 is removed from the ink jet apparatus 100, the head cover 10 is attached, thereby preventing ink dripping and contamination inside and outside the ink jet apparatus. Further, the relative movement of the cover delivery guide 51 for attaching and detaching the head cover 10 may utilize the operation of the maintenance mechanism in the ink jet apparatus.

  In this embodiment, the cover delivery guide 51 and the eccentric cam mechanism 52 are provided in the maintenance / recovery mechanism 181, but it goes without saying that the present invention is not limited to this form. In this embodiment, the image forming apparatus is a type that supplies ink to the head Md. However, the present invention is not limited to this mode, and is a cartridge-integrated type that does not supply ink to the head Md or a type in which the head and the tank are separated. Needless to say, the present invention can be applied to an image forming apparatus.

  In the present embodiment, the ink jet recording apparatus has been described. However, the present invention is not limited to this, and an ink jet image forming apparatus or recording apparatus such as a copying machine, a facsimile, a printer, a plotter, or a multifunction machine having these functions, Needless to say, the present invention can be applied to an ink jet head or a droplet discharge device mounted in such an image forming apparatus or recording apparatus.

  Further, in the present invention, the “paper” is not limited to paper, but it means that a liquid that can be penetrated by an aqueous liquid can be attached. A recording medium, a recording medium, a recording paper, a recording paper And so on. In addition, image formation, recording, printing, printing, and printing are all synonymous.

  “Image forming apparatus” means an apparatus that forms an image by ejecting liquid onto paper. “Image forming” only applies an image having a meaning such as a character or a figure to a medium. It also means that an image having no meaning such as a pattern is imparted to a sheet (simply causing a droplet to land on a medium).

  In addition, the “ink” is not limited to what is called an ink unless specifically limited, and is used as a general term for all liquids that can perform image formation, such as a recording liquid and a liquid. For example, DNA samples, resists, pattern materials, resins and the like are also included.

  In addition, the “image” is not limited to a planar image, and includes an image given to a three-dimensionally formed image and an image formed by three-dimensionally modeling a solid itself.

In addition, the materials and dimensions of each component introduced in the above-described embodiment are merely examples, and it is needless to say that various materials and dimensions can be selected within a range in which the effects of the present invention can be exhibited.

10 Head cover (an example of a protective cover)
DESCRIPTION OF SYMBOLS 11 Side wall 11a Side wall nail | claw 11b 3rd engagement groove 12 Concave part 13 Communication hole 14 Folding part 14a Folding convex part 15 Absorbent 20 Head (an example of a droplet discharge head)
20a First engagement groove 20b Second engagement groove 21 Nozzle plate 22 Nozzle surface 25 Ink path 30 Tank 31 Joint portion 32 Ink supply path 35 Residual ink 40 Head Md (head unit)
50 Base part 51 Cover delivery guide 52 Cam mechanism (an example of a switching mechanism)
60 Liquid droplet ejection apparatus 100 Inkjet recording apparatus (an example of an image forming apparatus)
181 Maintenance and recovery mechanism A, B, C Cost

JP 2009-66909 A JP 2003-127402 A JP 2002-321377 A JP-A-5-345412

Claims (7)

A droplet discharge device having a detachable droplet discharge head,
The droplet discharge head comprising at least one nozzle hole for discharging a liquid;
A droplet discharge device having a protective cover covering the nozzle hole,
An attachment / detachment means capable of attaching / detaching the protective cover from the droplet discharge head;
The protective cover can be repositioned between a first position where a part of the protective cover is not in contact with the nozzle hole and a second position where the protective cover is in contact.
A switching mechanism for switching the position of the part of the protective cover between the first position and the second position;
The droplet discharge head is attached to a droplet discharge device with the protective cover in the first position attached.
When the droplet discharge head is attached to the droplet discharge device, the protective cover is removed by the attaching / detaching means,
When removing the droplet discharge head, the protective cover switched to the second position by the switching mechanism is attached to the droplet discharge head by the attaching / detaching means, and the liquid discharge head is removed from the droplet discharge device. A droplet discharge device characterized by that.   The droplet discharge device according to claim 1, wherein the switching mechanism is a cam mechanism that applies an external load to the protective cover.   The first position and the second position are generated by deforming at least a part of the protective cover, and maintain the positions unless an external load is applied to the protective cover. The droplet discharge device according to claim 1 or 2.   The droplet discharge device according to claim 3, wherein at least a part of the protective cover is an elastic body, and is urged against the nozzle hole by an elastic force of the elastic body.   The droplet discharge apparatus according to claim 1, wherein the protective cover includes an absorbent material. A droplet discharge apparatus having a tank for storing liquid discharged from the droplet discharge head,
The tank has an openable / closable portion at the top thereof,
The droplet discharge device according to claim 5, wherein the protective cover has a communication hole that allows communication between the inside and the outside.   An image forming apparatus comprising the droplet discharge device according to claim 1.

Images