Image forming apparatus

An image forming apparatus includes a recording head configured to jet droplets of recording liquid; a maintenance device configured to maintain/restore a condition of the recording head, whereby the maintenance device is detachably attached to a body of the image forming apparatus; and a waste liquid tank configured to hold waste liquid collected by the maintenance device, whereby the waste liquid tank is disposed adjacent to the maintenance device. The maintenance device has a jetting tube configured to discharge the waste liquid into the waste liquid tank. The waste liquid tank includes an induction opening surrounding the jetting tube, whereby the induction opening has a notch through which the jetting tube passes when the maintenance device is detached from the body. The image forming apparatus further includes a wall member configured to block at least part of the notch when the maintenance device is attached in the body.

BACKGROUND

1. Technical Field

The disclosure relates to an image forming apparatus, and more particularly to an image forming apparatus including a recording head for jetting liquid droplets of recording liquid; a maintenance device that is detachably attached to the apparatus, which is for maintaining/restoring the condition of the recording head; and a waste liquid tank for holding waste liquid that has been collected by the maintenance device, whereby the waste liquid tank is disposed adjacent to the maintenance device.

2. Description of the Related Art

There is known an inkjet recording apparatus which is an image forming apparatus such as a printer, a fax machine, a copier, and a multifunction peripheral including printer/fax/copier functions. In the inkjet recording apparatus, a recording head, which is (image forming unit) constituted by a liquid droplet jetting head for jetting liquid droplets of recording liquid, is used for forming images (recording and printing are also used as synonyms) by causing liquid droplets (hereinafter, also referred to as ink droplets) of recording ink to adhere onto a sheet while conveying the sheet.

There are various types of liquid droplet jetting heads, such as a piezo type, a thermal type, and an electrostatic type. The piezo type uses an electromagnetic transducer element such as a piezoelectric element. The thermal type uses an electrothermal element such as a heat element provided in the jetting head for jetting ink droplets by generating bubbles due to film boiling. The electrostatic type uses an electrostatic force to deform oscillating plates which form walls of a jetting chamber for jetting ink droplets.

In an inkjet recording apparatus, ink droplets are jetted from fine jetting outlets. Therefore, the jetting outlets may become clogged when the ink dries and the viscosity of the ink increases or the ink solidifies, or when bubbles are generated in the ink. As a result, jetting failures may occur. In order to prevent such jetting failures, there is provided a maintenance device for maintaining the ink jetting function in a normal state and restoring the ink jetting function.

For example, such a maintenance device includes the following mechanisms. One mechanism is for restoring the jetting outlet by filling the recording head with ink with the use of a pressurizing unit, in the event that a jetting failure occurs due to bubbles that have been generated in the jetting outlet during a recording operation. Another mechanism is for performing preliminary jetting (idle jetting) in preparation for when the viscosity of the ink increases or the ink solidifies due to natural evaporation of the ink in the jetting outlets. Yet another mechanism is for wiping off ink droplets and dust that have adhered to the surface of the jetting outlets. Two or more of these mechanisms may be combined.

Patent document 1 describes an apparatus in which an outer cover is detachably attached to the backside of the apparatus main body. On the inside of the outer cover, a waste liquid tank for holding waste liquid received from a maintenance/recovery mechanism, is detachably attached to the apparatus main body. The outer cover can be removed to retrieve the waste liquid tank, and provide a new waste liquid tank or reuse the same waste liquid tank. In conjunction with the waste liquid tank and the maintenance device being retrieved from the apparatus main body, the waste liquid tube part is blocked with a shutter mechanism.

Patent document 2 describes a liquid ejecting device including a liquid ejecting head for ejecting liquid; a cleaning unit for cleaning the liquid ejecting head by ejecting liquid from the liquid ejecting head through a liquid path; and a detachably attached liquid storing unit for storing the liquid ejected by the cleaning unit, whereby the liquid storing unit is disposed on the outlet side of the liquid path. The liquid storing unit includes an absorbing unit for absorbing the liquid, and a forced dropping unit for forcibly dropping the liquid remaining in the liquid path to a liquid receiving position of the absorbing unit when the liquid storing unit is detached from the liquid ejecting device.

However, in the apparatus described in patent document 1, the ink cannot be prevented from scattering while the image forming apparatus is operating.

In the device described in patent document 2, the ink cannot be prevented from scattering while the image forming apparatus is operating, and moreover, when the maintenance unit is retrieved from the image forming apparatus, ink cannot be prevented from spilling out of the maintenance device.

BRIEF SUMMARY

In a aspect of this disclosure, there is provided an image forming apparatus including a simple mechanism with which waste liquid is prevented from scattering out of a waste liquid jetting tube part of a maintenance device, and ink is prevented from spilling out of a maintenance device when the maintenance device is retrieved.

According to another aspect, there is provided an image forming apparatus including a recording head configured to jet liquid droplets of recording liquid; a maintenance device configured to maintain/restore a condition of the recording head, whereby the maintenance device is detachably attached to an apparatus main body of the image forming apparatus; and a waste liquid tank configured to hold waste liquid collected by the maintenance device, whereby the waste liquid tank is disposed adjacent to the maintenance device, wherein the maintenance device includes a waste liquid jetting tube configured to discharge the waste liquid into the waste liquid tank; the waste liquid tank includes an induction opening substantially surrounding the waste liquid jetting tube, whereby the induction opening includes a notch part through which the waste liquid jetting tube passes when the maintenance device is detached from the apparatus main body; and the image forming apparatus further includes a wall member configured to block at least part of the notch part when the maintenance device is attached in the apparatus main body.

According to another aspect, there is provided an image forming apparatus including a recording head configured to jet liquid droplets of recording liquid; a maintenance device configured to maintain/restore a condition of the recording head, whereby the maintenance device is detachably attached to an apparatus main body of the image forming apparatus; and a waste liquid tank configured to hold waste liquid collected by the maintenance device, Whereby the waste liquid tank is disposed adjacent to the maintenance device, wherein the maintenance device includes a waste liquid jetting tube configured to discharge the waste liquid into the waste liquid tank; the waste liquid tank includes an induction opening substantially surrounding the waste liquid jetting tube; and at least part of the induction opening is formed with an elastic member configured to deform as the waste liquid jetting tube of the maintenance device contacts the elastic member, so that the waste liquid jetting tube can pass through the induction opening.

According to an exemplary embodiment, an image forming apparatus is provided, which includes a wall member that blocks at least part of a notch part of an induction opening of a waste liquid tank when a maintenance device is attached to the main body of the image forming apparatus, so that waste liquid scattered from a waste liquid jetting tube part of the maintenance device is blocked by the wall member of the induction opening, thereby preventing waste liquid from scattering with a simple mechanism.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A description is given, with reference to the accompanying drawings, of embodiments of the present invention.

A description is given of an inkjet recording apparatus which is an image forming apparatus according to an embodiment of the present invention.FIG. 1is a schematic side view of an inkjet recording apparatus according to an embodiment of the present invention. An inkjet recording apparatus100includes a recording device engine120for forming images, whereby the recording device engine120is provided inside an apparatus main body110. A carriage160provided with recording heads150is provided in the recording device engine120. The recording heads150are moved in a main scanning direction along a rod190.

The inkjet recording apparatus100includes a sheet feeding unit130where recording media P is placed, whereby the sheet feeding unit130is located at the bottom of the apparatus main body110. A recording medium that is fed out of the sheet feeding unit130is conveyed in a sub scanning direction by a belt140which is a sub scanning conveying unit.

The recording medium is then moved in a main scanning direction by the belt140while ink is jetted from the recording heads150of the carriage160that is driven in a main scanning direction, so that an image is formed on the recording medium.

The recording device engine120includes an ink cartridge170, an ink collecting container180, and a maintenance device200. When the ink cannot be normally jetted from the recording heads150, the maintenance device200performs a function recovery process on the recording heads150by suctioning the ink from the recording heads150through a auctioning cap240with the use of a pump210. The auctioned waste liquid is provided through a waste liquid jetting tube part220that extends down from the bottom of a main unit270of a maintenance device200, and into a waste liquid tank300having an induction opening310. The maintenance device200includes moisture caps230for preventing the recording heads150from drying, a wiper blade250for cleaning the jetting outlets of the recording heads150, and an ink collecting opening260for collecting the ink that has been removed by the wiper blade250.

Next, a description is given of the location of the maintenance device200in the inkjet recording apparatus100.FIG. 2is a perspective view of a state where the maintenance device200is detached from the main unit of the image forming apparatus. The maintenance device200is for receiving ink that is suctioned from the recording heads150, and ink that is not used for printing but jetted for the purpose of maintaining the conditions of the recording heads150(idle jetting). This ink solidifies and deposits in the maintenance device200. Accordingly, the operating life of the maintenance device200is typically set to be shorter than that of the apparatus main body110. Thus, the maintenance device200is configured to be easily retrieved (detached) from the apparatus main body110. Specifically, the maintenance device200can be retrieved by sliding out the maintenance device200through an opening part112provided on a side surface part111of the apparatus main body110.

FIGS. 3A and 3Billustrate the maintenance device200and the waste liquid tank300.FIG. 3Ais a schematic front view of the maintenance device200and the waste liquid tank300.FIG. 3Bis a perspective view of a duct part of the waste liquid tank300.

In the present embodiment, the maintenance device200is detachably attached to the apparatus main body110of the image forming apparatus, so that the maintenance device200can be retrieved by sliding it out. The waste liquid jetting tube part220extends down from the bottom of the maintenance device200. The waste liquid tank300is positioned beneath the maintenance device200of the apparatus main body110, and the induction opening310is positioned at the top part of the waste liquid tank300so as to surround the waste liquid jetting tube part220. The waste liquid from the waste liquid jetting tube part220of the maintenance device200is discharged through the induction opening310and transferred into the waste liquid tank300. The induction opening310has a peripheral wall part320substantially surrounding the waste liquid jetting tube part220. In the present embodiment, in one side of the peripheral wall part320, there is formed a notch part330through which the waste liquid jetting tube part220can pass when sliding the waste liquid jetting tube part220along a direction indicated by an arrow A (seeFIGS. 2 and 3B) to retrieve the maintenance device200from the apparatus main body110.

Merely forming the notch part330in the image forming apparatus may not be sufficient for preventing the following failure.FIGS. 4A through 4Cschematically illustrate a failure of the image forming apparatus.FIG. 4Cis a perspective magnified view of the circled part inFIG. 4B. When there is no ink adhering to the end of the waste liquid jetting tube part220, as shown inFIG. 4A, ink280that is discharged from the waste liquid jetting tube part220drops straight down and enters the waste liquid tank300through the induction opening310. However, when there is solid ink290adhering to the end of the waste liquid jetting tube part220(FIG. 4C), an end opening221of the waste liquid jetting tube part220is blocked by the solid ink290. Accordingly, the end opening221of the waste liquid jetting tube part220may become very small, and may be directed sideways. When the end opening221reaches the notch part330that is cut out in the peripheral wall part320shown inFIGS. 3A and 3B, the ink280may scatter out from the notch part330and soil the inside of the image forming apparatus.

Furthermore, the waste liquid may not be completely removed, and may still be remaining in the waste liquid jetting tube part220of the maintenance device200. Due to the impact when the maintenance device200is retrieved from the image forming apparatus in such a condition, the ink remaining in the waste liquid jetting tube part220may drop. Thus, the inside or the image forming apparatus or the floor on which the image forming apparatus is placed may be soiled.

Accordingly, in the present embodiment, a wall member covering the notch part330of the waste liquid tank300is provided in the maintenance device200. The wall member may have various configurations. First, a description is given of a liquid droplet jetting device according to a first embodiment.FIGS. 5A and 5Billustrate a liquid droplet jetting device according to the first embodiment.FIG. 5Aschematically illustrates the state where the maintenance device200is detached from the inkjet recording apparatus100,FIG. 5Bschematically illustrates the state where the maintenance device200is attached to the inkjet recording apparatus100, andFIG. 6is a perspective view of the liquid droplet jetting device according to the present embodiment. In the present embodiment, as shown inFIG. 5A, a wall member400is provided in the maintenance device200. The wall member400has a plate410made of Mylar (registered trademark) extending down from the main unit270of the maintenance device200. In the present embodiment, when the maintenance device200is set into the apparatus main body110of the inkjet recording apparatus100, the plate410of the wall member400contacts the periphery of the notch part330formed in the peripheral wall part320of the waste liquid tank300so as to cover the notch part330, as shown inFIG. 5BandFIG. 6. Accordingly, in the liquid droplet jetting device according to the present embodiment, when the maintenance device200is attached to the inkjet recording apparatus100, the plate410covers the notch part330of the peripheral wall part320, so that waste liquid (ink) scattering from the waste liquid jetting tube part220is prevented from scattering outside from the waste liquid tank300.

Next, a description is given of a modification of the liquid droplet jetting device according to a second embodiment.FIGS. 7A and 7Billustrate the liquid droplet jetting device according to the second embodiment.FIG. 7Aschematically illustrates the state where the maintenance device200is detached from the inkjet recording apparatus100, andFIG. 7Bschematically illustrates the state where the maintenance device200is attached to the inkjet recording apparatus100. In a wall member500, a plate510is provided in such a manner as to pivot on a shaft520. In between the plate510and the main unit270of the maintenance device200, an extension coil spring530is provided so that the plate510is urged against the main unit270. In such a configuration, when the maintenance device200is not attached to the apparatus main body110, as shown inFIG. 7A, the plate510is positioned beneath the waste liquid jetting tube part220due to the extension coil spring530, so as to block waste liquid dropping from the waste liquid jetting tube part220. Meanwhile, when the maintenance device200is attached to the inkjet recording apparatus100, as shown inFIG. 7B, the plate510contacts the induction opening310of the waste liquid tank300and pivots, so as to cover the notch part330of the peripheral wall part320. Accordingly, the waste liquid (ink) scattering from the waste liquid jetting tube part220is prevented from scattering out from the notch part330.

According to the present embodiment, the maintenance device200is provided with the wall member500. Therefore, while the maintenance device200is attached to the inkjet recording apparatus100, it is possible to prevent soiling caused by the waste liquid scattering from the waste liquid jetting tube part220. Meanwhile, when the maintenance device200is detached from the inkjet recording apparatus100, the ink dropping from the moisture caps230of the maintenance device200can be blocked, so that the image forming apparatus is prevented from being soiled due to dropping ink.

Next, a description is given of a modification of the second embodiment.FIG. 8schematically illustrates a liquid droplet jetting device according to the modification of the second embodiment. In the present embodiment, the main unit270of the maintenance device200is provided with a damper device540for absorbing the impact caused when the plate510contacts the main unit270of the maintenance device200. The damper device540is, for example, a rubber member, which is disposed on the bottom side of the main unit270. Specifically, the damper device540is located on the bottom side of the main unit270, where the plate510contacts the main unit270upon pivoting along a trajectory by being urged by the extension coil spring530. According to the present embodiment, when the maintenance device200is retrieved from the apparatus main body110of the inkjet recording apparatus100, the waste liquid adhering to the plate510is prevented from scattering around when the plate510impacts the maintenance device200.

Next, a description is given of another modification of the second embodiment.FIG. 9schematically illustrates a liquid droplet jetting device according to the other modification of the second embodiment. In the present embodiment, the plate510and the shaft520of the wall member500are combined as a single unit, which is detachably attached to a hole part271formed in the main unit270of the maintenance device200. The main unit270of the maintenance device200is made of synthetic resin that is elastically deformable. The hole part271is made by forming an opening on the bottom side of the main unit270.

Next, a description is given of a third embodiment.FIGS. 10A and 10Billustrate a liquid droplet jetting device according to the third embodiment.FIG. 10Aschematically illustrates the state of the maintenance device200detached from the inkjet recording apparatus100, andFIG. 10Bschematically illustrates the state of the maintenance device200attached to the inkjet recording apparatus100. In the present embodiment, a wall member600is provided in the waste liquid tank300disposed in the apparatus main body110of the inkjet recording apparatus100.

In the wall member600according to the present embodiment, a plate610is rotatably provided on a shaft620that is disposed in the waste liquid tank300, and the plate610has a coil spring630and a contact plate640. The coil spring630urges the plate610in the direction toward the outside of the notch part330, and the contact plate640is fixed to the plate610such that a substantial right angle is formed between the contact plate640and the plate610. When the waste liquid jetting tube part220of the maintenance device200contacts the contact plate640, the plate610rotates to a position where it seals the notch part330.

In the present embodiment, when the maintenance device200is attached to the apparatus main body110of the inkjet recording apparatus100, as shown inFIG. 10B, the contact plate640is pressed by the pump210, so that the plate610rises and covers the notch part330of the peripheral wall part320.

According to the present embodiment, the maintenance device200is provided with the wall member600. Therefore, while the maintenance device200is attached to the inkjet recording apparatus100, it is possible to prevent soiling caused by the waste liquid scattering from the waste liquid jetting tube part220.

Next, a description is given of a fourth embodiment.FIGS. 11A and 11Billustrate a liquid droplet jetting device according to the fourth embodiment.FIG. 11Aschematically illustrates the state of the maintenance device200set inside the inkjet recording apparatus100, andFIG. 11Bschematically illustrates the state of the maintenance device200being attached into the inkjet recording apparatus100.

In the present embodiment, at a position corresponding to the notch part330, the peripheral wall part320of the waste liquid tank300is provided with an elastic rubber plate member710, in such a manner as to cover the notch part330. In the present embodiment, when the maintenance device200is attached into the inkjet recording apparatus100, as shown inFIG. 11B, the waste liquid jetting tube part220of the maintenance device200contacts the plate member710, so that the plate member710elastically deforms. Accordingly, the maintenance device200can be easily attached in the inkjet recording apparatus100. When the maintenance device200is set inside the inkjet recording apparatus100, as shown inFIG. 11A, the plate member710returns to its original shape, so that the waste liquid scattering from the waste liquid jetting tube part220is prevented from scattering outside of the peripheral wall part320.

Furthermore, when the maintenance device200is retrieved from the apparatus main body110, the plate member710deforms in the direction opposite to that when the maintenance device200is attached, so that the maintenance device200can be easily retrieved from the inkjet recording apparatus100.

Thus, according to the present embodiment, with a simple structure of providing a plate member to the waste liquid tank, the maintenance device can be easily attached/detached, and soiling caused by scattering waste liquid can be prevented.

The present application is based on Japanese Priority Patent Application No. 2008-193088, filed on Jul. 28, 2008, the entire contents of which are hereby incorporated herein by reference.