JP2008302501A - Waste liquid storage vessel and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that a fill-up state has been detected though a waste liquid can be absorbed by the growth of a deposit when absorbing the waste liquid which generates the deposit. <P>SOLUTION: The absorber 102 which absorbs a waste ink is set in a case body 101. A waste liquid absorption route 110 turned back by the absorber 102 is formed of a rib 107 as a partition wall prepared in the case body 101 from a dumping point of the waste liquid (point corresponding to a waste liquid dumping opening 104) to a detection point by a waste liquid fill-up state sensor 112 where the waste liquid is detected to be in the fill-up state. Moreover, a notch 108 is formed near the waste liquid dumping point in the rib 107, thus making the rib lower than a part near the detection point. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a waste liquid storage container and an image forming apparatus, and more particularly to a waste liquid storage container for storing a waste liquid of the recording liquid generated by a maintenance recovery operation for maintaining the performance of a recording head that discharges recording liquid droplets. The present invention relates to an image forming apparatus including a container.

  In general, a printer, a fax machine, a copier, a plotter, or an image forming apparatus that combines a plurality of these functions includes, for example, a recording head composed of a liquid ejection head that ejects liquid droplets of recording liquid (liquid). Using a liquid ejection apparatus, while conveying a medium (hereinafter also referred to as “paper”, the material is not limited, and a recording medium, a recording medium, a transfer material, recording paper, and the like are also used synonymously). In addition, there is an ink jet recording apparatus that performs image formation (recording, printing, printing, and printing are also used synonymously) by attaching a recording liquid (hereinafter also referred to as ink) as a liquid to a sheet.

  The “image forming apparatus” means an apparatus that forms an image by discharging liquid onto a medium such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, etc. “Formation” means not only giving an image having a meaning such as a character or a figure to a medium but also giving an image having no meaning such as a pattern to the medium. The “liquid” is not limited to the recording liquid and the ink, and is not particularly limited as long as it becomes a fluid when ejected (hereinafter referred to as “ink”). The “liquid ejecting apparatus” means an apparatus that ejects liquid from a liquid ejecting head, and is not limited to an apparatus that performs image formation.

  In addition, as an image forming apparatus including a liquid discharge head, a serial type image recording apparatus that performs recording by mounting the head on a carriage and moving the head in a main scanning direction orthogonal to the paper feeding direction, and a substantially full width of the recording area There is a line type image recording apparatus using a line type head in which a plurality of discharge ports (nozzles) for discharging droplets are arranged in a row.

  The recording head in the image forming apparatus using such a recording liquid has a recording liquid caused by evaporation of the solvent from the nozzle because the recording liquid pressurized in the pressure generating chamber is discharged from the nozzle onto the paper for recording. There is a problem in that a recording failure occurs due to a discharge failure due to an increase in viscosity, solidification of ink, adhesion of dust, and mixing of bubbles.

  Therefore, the liquid ejection type image forming apparatus is provided with a capping unit for sealing the nozzles of the recording head during non-recording and a wiping member for cleaning the nozzle forming surface as necessary, and does not contribute to recording. An empty discharge receptacle for empty discharge is provided. The capping unit not only functions as a lid for preventing the ink of the nozzle from drying, but also when the nozzle is clogged, the nozzle forming surface is sealed by the capping unit, and the negative pressure from the suction pump is used. Also, it has a function of eliminating nozzle clogging by sucking and discharging ink (head suction) from the nozzle.

  The forcible suction and discharge process of ink performed to eliminate clogging of the recording head is called a cleaning operation. For example, when recording is resumed after a long pause of the recording apparatus, or at predetermined intervals during recording. Or when the user recognizes a recording state failure and operates the cleaning switch, and after the ink is discharged from the recording head, the wiping member made of an elastic member such as rubber causes the nozzle surface (nozzle of the recording head) This is accompanied by a cleaning operation for wiping off the surface on which is formed. During recording, idle ejection is performed at a required timing.

  Then, the waste liquid from the recording head discharged into the capping means in accordance with the above-described cleaning operation can be disposed in a waste liquid storage container (hereinafter also referred to as “waste liquid tank”) by driving the suction pump. Has been. In this waste liquid tank, a waste liquid absorber (absorber) generally made of a porous material is accommodated, and the waste liquid is absorbed and held by the waste liquid absorber.

As a waste liquid tank containing such a waste liquid absorbing material, for example, as described in Patent Document 1, an ink absorbing material is provided in a casing constituting the ink containing portion, and the ink containing portion contains the ink containing material. Some walls are provided with walls that serve as weirs that prevent movement of the waste ink in one direction while maintaining communication of the entire section.
JP 2005-297495 A

Moreover, as described in Patent Document 2, the container body includes an absorber that absorbs the waste liquid, and the absorbent body has a portion whose compressibility is different from that of the other portions due to partial pressing. There is a structure in which a space is formed corresponding to a portion to be supplied, and a partition wall member that covers a part of the wall surface of the space of the absorber is provided.
JP 2006-150872 A

Patent Document 3 discloses an image forming apparatus that discharges recording liquid droplets to form an image on a recording medium, a waste liquid storage container having a space for storing waste liquid, and a waste liquid in the space of the waste liquid storage container. There is described an image forming apparatus comprising means for obtaining a correlation value correlating with the deposition state and means for determining whether or not the correlation value exceeds a predetermined reference value.
JP 2006-159465 A

  By the way, since the ink is required to have a quick drying property due to an increase in the recording speed of the image forming apparatus, a pigment-based ink having a high viscosity (5 cP or more is defined as a high viscosity) has come to be used. Yes. As described in Patent Documents 2 and 3, in a waste liquid tank that contains waste ink having a high ink viscosity such as a high-viscosity ink having a high pigment concentration, the waste ink introduced into the waste liquid tank is used. Has become a semi-solid and deposits as a deposit. The waste ink deposition rate in the waste liquid tank varies greatly depending on the frequency of use of the apparatus and the use environment.

  In addition, the waste liquid tank has a purpose of detecting the life of the waste liquid tank when the waste liquid absorber provided for absorbing and holding the input waste ink liquid has completely absorbed the waste ink. A tongue sensor is provided.

  This full tank sensor is extremely reliable because it can accurately detect the end of absorption of waste ink in the absorber. Therefore, if it can detect not only waste ink that has penetrated into the absorber but also full tank in the waste liquid tank due to accumulation of accumulated ink. Therefore, it is possible to avoid the overflow of the accumulated ink from the waste liquid tank and to detect the fullness of the accumulated ink with higher accuracy, so that the reliability can be improved and the waste liquid tank can be used. You will be able to use up to full.

  However, in conventional waste liquid tanks and image forming apparatuses, the waste ink that has been input to the waste liquid input portion is absorbed by the absorber, and the absorber portion corresponding to the detection portion by the full sensor passes through the waste liquid absorption path by the absorber. Before it becomes absorbed, waste ink flows directly from the deposit into the detection site of the full sensor and full tank is detected, or because it is a soft detection, there are unabsorbed parts in the absorber. However, the full tank is detected, but there is a problem that the absorber is not effectively used.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to prolong the life of a waste liquid storage container that stores waste liquid that causes deposition.

  In order to solve the above problems, a waste liquid storage container according to the present invention is a waste liquid storage container for storing a waste liquid of a recording liquid generated by a maintenance recovery operation for maintaining the performance of a recording head that discharges a recording liquid droplet. An absorber that absorbs the waste liquid is laid in the container body, and the partition wall provided in the container body wraps the absorbent from the waste liquid input part to the detection part where the waste liquid is detected to be full. The waste liquid absorption path is formed, and the partition wall is configured such that the height of the part beside the waste liquid input part is lower than the height of the part beside the detection part.

  Here, the partition wall has a configuration in which a notch is formed in the part beside the waste liquid input part, or the height of the partition wall is from the part beside the detection part toward the part beside the waste liquid input part. It can be set as the structure inclined so that it may become low.

  Moreover, it can be set as the structure whose height of an absorber is higher than the height of a partition wall. Moreover, an absorber can consist of a several layer, and it can be set as the structure where the density of each layer is so low that it becomes an upper layer. Further, the absorber can be configured such that the density of the part corresponding to the part of the partition wall beside the waste liquid input part is higher than the density of the other part. Moreover, it can be set as the structure by which the absorber is laid also in the waste liquid injection | throwing-in site | part.

  The image forming apparatus according to the present invention includes the waste liquid container according to the present invention.

  According to the waste liquid container according to the present invention, an absorber that absorbs the waste liquid is laid in the container main body, and the partition wall provided in the container main body detects that the waste liquid is full from the waste liquid input site. Since the waste liquid absorption path folded by the absorber is formed up to the detection site, the partition wall is formed so that the height of the part beside the waste liquid injection part is lower than the height of the part beside the detection part When the waste liquid deposit grows, absorption by the absorber starts from the middle of the waste liquid absorption path through a relatively low part of the partition wall at a position away from the detection site. By being suppressed, the use efficiency of the absorber until full tank detection is improved, and the life can be extended.

  According to the image forming apparatus of the present invention, since the waste liquid storage container according to the present invention is provided, the life of the waste liquid storage container is extended.

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a perspective explanatory view of an ink jet recording apparatus as an image forming apparatus according to the present invention including a device for discharging droplets according to the present invention as viewed from the front side.
The ink jet recording apparatus includes an apparatus main body 1, a paper feed tray 2 for loading paper loaded in the apparatus main body 1, and a sheet on which an image is recorded (formed) by being detachably mounted on the apparatus main body 1. A paper discharge tray 3 for stocking is provided. Furthermore, a cartridge loading for loading an ink cartridge that protrudes from the front surface to the front side of the apparatus main body 1 and is lower than the upper surface is provided at one end side of the front surface of the apparatus main body 1 (side of the paper supply / discharge tray section). The cartridge loading unit 4 has an operation / display unit 5 provided with operation buttons and a display.

  The cartridge loading unit 4 contains a plurality of recording liquids (inks) that are different color materials, such as black (K) ink, cyan (C) ink, magenta (M) ink, and yellow (Y) ink. Ink cartridges 10k, 10c, 10m, and 10y (which are referred to as “ink cartridge 10” when colors are not distinguished) are inserted from the front side of the apparatus main body 1 toward the rear side and can be loaded. A front cover (cartridge cover) 6 that is opened when the ink cartridge 10 is attached or detached is provided on the front side of the cartridge loading unit 4 so as to be openable and closable.

Next, the mechanism part of the ink jet recording apparatus will be described with reference to FIGS. 2 is a schematic side view illustrating the outline of the mechanism, and FIG. 3 is an explanatory plan view of the main part.
The carriage 33 is slidably held in the main scanning direction by main and slave guide rods 31 and 32 which are guide members horizontally mounted on the left and right side plates 21A and 21B. Move and scan in the direction indicated by the arrow (carriage main scanning direction).

  The carriage 33 is provided with recording heads 34a and 34b composed of liquid ejection heads for ejecting ink droplets of yellow (Y), cyan (C), magenta (M), and black (K). The “recording head 34” is arranged in a sub-scanning direction orthogonal to the main scanning direction, and the ink droplet ejection direction is directed downward.

  Each of the recording heads 34 has two nozzle rows. One nozzle row of the recording head 34a has black (K) droplets, the other nozzle row has cyan (C) droplets, and the recording head 34b has one nozzle row. One nozzle row ejects magenta (M) droplets, and the other nozzle row ejects yellow (Y) droplets.

  As an inkjet head constituting the recording head 34, a piezoelectric actuator such as a piezoelectric element, a thermal actuator that uses a phase change caused by film boiling of a liquid using an electrothermal transducer such as a heating resistor, and a metal phase change caused by a temperature change. It is possible to use a shape memory alloy actuator to be used, an electrostatic actuator using an electrostatic force, or the like provided as pressure generating means for generating a pressure for discharging a droplet.

  Further, the carriage 33 is equipped with head tanks 35a and 35b (referred to as “head tank 35” when not distinguished) for supplying ink of each color corresponding to the nozzle rows of the recording head 34. As described above, the sub tank 35 is supplied with ink of each color from the ink cartridge 10 of each color mounted in the cartridge loading unit 4 via the supply tube 36 of each color. The cartridge loading 4 is provided with a supply pump unit 24 for feeding ink in the ink cartridge 10.

  On the other hand, as a paper feeding unit for feeding the papers 42 stacked on the paper stacking unit (pressure plate) 41 of the paper feeding tray 2, a half-moon roller (feeding) that separates and feeds the papers 42 one by one from the paper stacking unit 41. A separation pad 44 made of a material having a large friction coefficient is provided facing the paper roller 43) and the paper feed roller 43, and the separation pad 44 is urged toward the paper feed roller 43 side.

  In order to feed the paper 42 fed from the paper feeding unit to the lower side of the recording head 34, a guide member 45 for guiding the paper 42, a counter roller 46, a transport guide member 47, and a tip pressure roller. And a holding belt 48 which is a conveying means for electrostatically attracting the fed paper 42 and conveying it at a position facing the recording head 34.

  The transport belt 51 is an endless belt, and is configured to wrap around the transport roller 52 and the tension roller 53 and circulate in the belt transport direction (sub-scanning direction). Further, a charging roller 56 that is a charging unit for charging the surface of the transport belt 51 is provided. The charging roller 56 is disposed so as to come into contact with the surface layer of the transport belt 51 and to rotate following the rotation of the transport belt 51. The transport belt 51 rotates in the belt transport direction when the transport roller 52 is rotationally driven through timing by a sub-scanning motor (not shown).

  Further, as a paper discharge unit for discharging the paper 42 recorded by the recording head 34, a separation claw 61 for separating the paper 42 from the conveying belt 51, a paper discharge roller 62, and a paper discharge roller 63 are provided. The paper discharge tray 3 is provided below the paper discharge roller 62.

  A duplex unit 71 is detachably mounted on the back surface of the apparatus body 1. The duplex unit 71 takes in the paper 42 returned by the reverse rotation of the conveyance belt 51, reverses it, and feeds it again between the counter roller 46 and the conveyance belt 51. The upper surface of the duplex unit 71 is a manual feed tray 72.

  Further, a maintenance / recovery mechanism 81, which is a head maintenance / recovery device according to the present invention, includes a recovery means for maintaining and recovering the state of the nozzles of the recording head 34 in the non-printing area on one side of the carriage 33 in the scanning direction. Is arranged.

  The maintenance / recovery mechanism 81 includes cap members (hereinafter referred to as “caps”) 82a and 82b (hereinafter referred to as “caps 82” when not distinguished from each other) for capping the nozzle surfaces of the recording head 34, and nozzle surfaces. A wiper blade 83 that is a blade member for wiping the ink, and an empty discharge receiver 84 that receives liquid droplets when performing empty discharge for discharging liquid droplets that do not contribute to recording in order to discharge the thickened recording liquid. ing. A waste liquid tank 100 for storing waste liquid generated by the maintenance recovery operation is mounted on the lower side of the head recovery mechanism 81 in a replaceable manner with respect to the apparatus main body.

  Further, in the non-printing area on the other side of the carriage 33 in the scanning direction, there is an empty space for receiving liquid droplets when performing empty discharge for discharging liquid droplets that do not contribute to recording in order to discharge the recording liquid thickened during recording or the like. A discharge receiver 88 is disposed, and the idle discharge receiver 88 includes an opening 89 along the nozzle row direction of the recording head 34.

  In this image forming apparatus configured as described above, the sheets 42 are separated and fed one by one from the sheet feed tray 2, and the sheet 42 fed substantially vertically upward is guided by the guide 45, and includes the transport belt 51 and the counter. It is sandwiched between the rollers 46 and conveyed, and the leading end is guided by the conveying guide 37 and pressed against the conveying belt 51 by the leading end pressing roller 49, and the conveying direction is changed by approximately 90 °.

  At this time, a positive output and a negative output are alternately repeated with respect to the charging roller 56, that is, an alternating voltage is applied, and a charging voltage pattern in which the conveying belt 51 alternates, that is, in a sub-scanning direction that is a circumferential direction. , Plus and minus are alternately charged in a band shape with a predetermined width. When the paper 42 is fed onto the conveyance belt 51 charged alternately with plus and minus, the paper 42 is attracted to the conveyance belt 51, and the paper 42 is conveyed in the sub-scanning direction by the circular movement of the conveyance belt 51.

  Therefore, by driving the recording head 34 according to the image signal while moving the carriage 33, ink droplets are ejected onto the stopped paper 42 to record one line, and after the paper 42 is conveyed by a predetermined amount, Record the next line. Upon receiving a recording end signal or a signal that the trailing edge of the paper 42 has reached the recording area, the recording operation is finished and the paper 42 is discharged onto the paper discharge tray 3.

  Further, during printing (recording) standby, the carriage 33 is moved to the maintenance / recovery mechanism 81 side, and the recording head 34 is capped by the cap 82 to keep the nozzles in a wet state, thereby preventing ejection failure due to ink drying. . Further, the recording liquid is sucked from the nozzle by a suction pump (not shown) with the recording head 34 capped by the cap 82 (referred to as “nozzle suction” or “head suction”), and the thickened recording liquid and bubbles are discharged. Perform recovery action. Also, before the start of recording, during recording, etc., an empty discharge operation is performed to discharge ink (liquid droplets) not related to recording toward the empty discharge receiver. As a result, the stable ejection performance of the recording head 34 is maintained.

  Next, an example of the waste liquid tank 100 that is a waste liquid storage container in the image forming apparatus will be described with reference to FIGS. 4 is a perspective explanatory view of the waste liquid tank, FIG. 5 is a perspective explanatory view of the waste liquid tank excluding the lid member, FIG. 6 is a schematic cross-sectional explanatory view taken along section A of FIG. 4, and FIG. FIG. 8 is a schematic side cross-sectional explanatory view of the waste liquid tank.

  The waste liquid tank 100 includes a tank case main body (container main body) 101, an absorbent member (absorber) 102 made of a laminate that absorbs liquid waste liquid stored in the case main body 101, and an upper portion of the case main body 101. A covering lid member 103 is provided.

  In the waste liquid tank 100, the waste liquid discharged from the above-described maintenance / recovery mechanism 81 is input (supplied) into the case main body 101 from the waste liquid input port 104 provided in the lid member 103. Then, a space 105 where the bottom surface of the case main body 101 is exposed is formed by forming a portion where the absorber 102 is not provided corresponding to the portion where the waste liquid is introduced through the waste liquid inlet 104. Yes.

  As a result, the waste liquid can be directly reached the bottom surface of the case body 101 through the space 105 without directly putting it into the absorber 102, and the waste liquid with low fluidity and high viscosity is deposited in the space 105 and accommodated. In addition, the liquid 102 having high fluidity in the waste liquid put into the space 105 can be absorbed by the absorber 102.

  The case main body 101 is formed with ribs 107 that are partition walls that partition the side wall surface of the space 105. As a result, a part 102a of the absorbing member 102 faces the space 105, and the liquid waste liquid penetrates into the absorbing member 102 only from the wall surface part of the part 102a.

  Further, a waste liquid full detection means for detecting that the waste liquid in the waste liquid tank 100 is full, which also serves as a waste liquid tank presence sensor for detecting whether or not the waste liquid tank 100 is mounted on the lid member 103. A waste liquid full sensor 112 composed of a reflective photosensor is disposed on the absorbing member 102 with the rib 107 of the waste liquid inlet 104 interposed therebetween (see FIG. 8).

  In this way, the waste liquid full sensor 112 that detects that the waste liquid has become full from the waste liquid input part (part corresponding to the waste liquid input port 104) by the rib 107 that is a partition wall provided in the case main body 101. A waste liquid absorption path (path indicated by a white arrow in FIG. 6) 110 is formed by the absorbent body 102 until the detection site is detected.

  Then, a notch 108 is formed on the side wall surface of the space 105 of the rib 107, and the height of the portion beside the waste liquid charging portion of the rib 107 is the height of the portion beside the detection portion (the detection portion by the waste liquid full sensor 112). It is formed lower than this. That is, the notch 108 serves as a bypass that bypasses the inlet portion 102 a of the absorber 102 and sends waste ink to the absorber 102.

  In the waste liquid tank 100 configured as described above, waste ink discharged from, for example, the empty discharge receptacle 84 of the maintenance / recovery mechanism 81 enters the space 105 of the waste ink inlet 104 of the waste liquid tank 100 as shown in FIG. It is thrown in. If the waste ink put into the space 105 is liquid waste ink, it is absorbed from the portion 102a of the absorbing member 102, and the other waste ink is deposited in the space 105 as shown in FIGS. As it accumulates.

  Then, when the deposit 121 grows and reaches the height of the cutout portion 108 of the rib 107, as shown in FIG. In addition, as indicated by an arrow 500, a part flows into the absorber 102 side from the middle of the waste liquid absorption path 100 through the notch 108 and is absorbed. As a result, the growth rate of the deposit 121 is suppressed, and the use efficiency of the absorber 102 is improved.

  In other words, the remaining waste ink is absorbed from one entrance portion (end portion 102a of the absorber 102) of the waste liquid absorption path 110 until the deposit 121 grows to some extent, but the deposit 121 grows to some extent. After that, another entrance portion is formed between the entrance portion and the end portion of the waste liquid absorption path 110 (detection portion by the waste liquid full sensor 112), and the remaining remaining fluid ink is absorbed from this entrance portion. As a result, the growth of the deposit is suppressed and the use efficiency of the absorber is improved.

  Accordingly, it is possible to prevent the waste liquid tank 100 from being detected as being full even though unused portions remain in the absorber due to the growth of the deposit.

This point will be described in comparison with Comparative Example 1 shown in FIGS. 11 and 12 and Comparative Example 2 shown in FIGS. 13 and 14.
The comparative example 1 is a case where the notch portion is not provided in the rib 107 which is the partition wall, unlike the above embodiment. The lifetime of the waste liquid tank 100 is when the waste liquid has completely penetrated into the absorber 102 and is detected by the full sensor 112 or when the deposit 121 has completely accumulated.

  In this configuration, since the growth of the deposit 121 cannot be detected by the full sensor 112, the accumulation degree of the deposit 121 is detected by software when a value calculated from the amount of waste liquid input or the frequency reaches a certain threshold value. Become. In this case, the threshold value should generally be a value calculated under the conditions of the fastest deposition rate among all printing conditions. For this reason, when printing is performed under the printing conditions premised on setting the threshold value, the waste liquid tank 100 may be detected as being full in software in a situation where the waste liquid tank 100 is not actually full (the tank is not used up). In addition, the detection accuracy of software is lower than the detection by the full sensor.

  Further, in the second comparative example, unlike the above-described embodiment, a notch portion 128 between the full tank sensor 112 and the space of the waste liquid charging site is provided on the rib 107 which is a partition wall with the waste liquid charging site beside the full tank sensor 112. By providing, when the deposit 121 grows, fluid waste ink flows to the detection site side through the notch 128, so that the full sensor 112 detects full tank.

  Although this configuration has an advantage that it is possible to detect that the deposit 121 has grown using the full sensor 112, the growth of the deposit 121 itself is not suppressed, so that the absorber 102 can absorb it. In spite of this, the waste liquid tank 100 reaches the end of its life due to the growth of the deposit 121.

  On the other hand, the growth of the deposit can be suppressed by forming a bypass (notch portion 108 in this example) for bypassing the entrance of the waste liquid absorption path beside the waste liquid inlet portion as described above. Even when the absorber 102 has an absorption margin, the case where the full tank is detected and the waste liquid tank 100 reaches the end of its life is reduced.

  In this way, the waste liquid absorption path folded by the absorber is formed from the waste liquid input part to the detection part where the waste liquid is detected to be full in the partition wall provided in the container body, and the partition wall is When the height of the part beside the waste liquid injection site is lower than the height of the part beside the detection part, when the waste liquid deposit grows, the partition wall is positioned at a position away from the detection part. The absorption into the absorber is started from the middle of the waste liquid absorption path through the part that is formed to be low, and the growth of the deposit is suppressed, improving the efficiency of use of the absorber until full tank detection and extending the service life. can do.

  In the above-described embodiment, the height of the absorber 102 is higher than the height of the partition wall (rib 107), so that when waste ink flows from the deposit 121 over the partition wall and flows into the absorber 102, absorption is performed. The waste ink can penetrate into the body 102.

  In addition, the absorber 102 is a laminated body composed of a plurality of layers, and the density of each layer is so low that the upper layer is higher, so that the waste ink that has overcome the partition wall more quickly than the waste ink accumulates in the space 105. Is penetrated into the absorber 102, the deposition rate of the deposit 121 can be suppressed.

  Further, the absorbent body 102 has a configuration in which the density of the portion corresponding to the side of the partition wall adjacent to the waste liquid input portion (the portion corresponding to the notch portion 108) is higher than the density of the other portions. When the waste ink flows over the partition wall and flows into the absorber 102, the waste ink can be permeated into the absorber 102.

  In addition, an absorber is also laid at the waste liquid input portion, that is, by configuring the absorber on the bottom surface of the space 105, the waste ink input to the waste liquid tank 100 is quickly transferred to the absorber. Since it penetrates, it is possible to avoid the increase in viscosity of the waste ink by avoiding the evaporation of water until it is charged and absorbed by the absorber.

Next, a waste liquid tank according to another embodiment of the present invention will be described with reference to FIGS. 9 is a schematic plan view of the waste liquid tank, and FIG. 10 is a schematic side sectional view of the waste liquid tank.
In the waste liquid tank 100, the rib 107 which is a partition wall is formed so as to be inclined so that the height decreases from a part near the part detected by the waste liquid full sensor 112 toward a part near the waste liquid input part.

  In such a configuration, the penetration into the absorber 102 can be controlled according to the height of the deposit 121.

  Ideally, it is preferable that the deposit 121 is full when the absorber 102 is used up. That is, 1/3 of the deposit 121 is accumulated when 1/3 ink penetrates into the absorber 102, and half of the deposit 121 is accumulated when half of the ink penetrates into the absorber 102. When filled with waste ink, the deposit 121 is preferably full.

  Therefore, by inclining the height of the rib 107 as described above, when the height of the deposit 121 is low, the ink flows from the deposit 121 into the absorber portion far from the detection portion of the absorber 102 by the full sensor 112. As the deposit 121 accumulates, it flows into the absorber part near the full sensor 112. Thus, finally, immediately before the deposit 121 overflows from the waste liquid tank 100, the waste liquid flows into the absorber 102 in the vicinity of the full tank sensor 112, and a full tank is detected.

1 is a perspective view illustrating an example of an image forming apparatus according to the present invention as viewed from the front side. 2 is a configuration diagram illustrating an outline of a mechanism unit of the image forming apparatus. FIG. It is principal part plane explanatory drawing of the mechanism part. FIG. 3 is a perspective explanatory view illustrating an example of a waste liquid tank of the image forming apparatus. It is an isometric view similarly shown except a cover member. It is typical plane explanatory drawing of the waste liquid tank. It is a typical sectional side view of the waste liquid tank. FIG. 5 is a schematic cross-sectional explanatory view taken along a cross section A in FIG. 4. It is typical plane explanatory drawing of the waste liquid tank which concerns on other embodiment of this invention. It is a typical sectional side view of the waste liquid tank. 6 is a schematic plan explanatory view of a waste liquid tank of Comparative Example 1. FIG. It is a typical sectional side view of the waste liquid tank. 10 is a schematic plan explanatory view of a waste liquid tank of Comparative Example 2. FIG. It is a typical sectional side view of the waste liquid tank.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Ink cartridge 33 ... Carriage 34a, 34b ... Recording head 81 ... Maintenance recovery mechanism 100 ... Waste liquid tank 101 ... Tank case main body 102 ... Absorbing member 103 ... Lid member 104 ... Waste liquid inlet part 105 ... Space 107 ... Rib 108 ... Cutting Notch 112 ... Waste liquid full sensor (full tank detection means)

Claims (8)

In a waste liquid storage container for storing the waste liquid of the recording liquid generated by the maintenance recovery operation for maintaining the performance of the recording head for discharging the recording liquid droplets,
An absorber that absorbs the waste liquid is laid in the container body,
From the waste liquid input site to the detection site where the waste liquid is detected to be full in the partition wall provided in the container body, a folded waste liquid absorption path by the absorber is formed,
The waste liquid container according to claim 1, wherein the partition wall is formed such that a height of a part beside the waste liquid input part is lower than a height of a part beside the detection part.   2. The waste liquid storage container according to claim 1, wherein a notch is formed in a part of the partition wall beside the waste liquid input part.   The waste liquid container according to claim 1, wherein the partition wall is inclined so that a height decreases from a part near the detection part toward a part near the waste liquid input part. Waste liquid container.   The waste liquid storage container according to any one of claims 1 to 3, wherein the height of the absorber is higher than the height of the partition wall.   The waste liquid storage container according to any one of claims 1 to 4, wherein the absorber includes a plurality of layers, and the density of each layer decreases as the upper layer increases.   The waste liquid storage container according to any one of claims 1 to 5, wherein the absorber has a density of a part corresponding to a part of the partition wall adjacent to the waste liquid input part higher than a density of other parts. Waste liquid container.   The waste liquid storage container according to any one of claims 1 to 6, wherein an absorber is also laid at the waste liquid injection site.   8. An image forming apparatus for forming an image on a recording medium by discharging recording liquid droplets from a recording head, comprising the waste liquid container according to claim 1. apparatus.

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