JP2009190302A - Waste liquid housing container for image forming apparatus and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a waste liquid housing container that can house a waste liquid without overflowing, even in a waste liquid housing container for housing a waste liquid of a high viscosity recording liquid, and to provide an image forming apparatus equipped with the above waste liquid housing container. <P>SOLUTION: When a waste liquid tank 100 is to be detached from a main apparatus according to an instruction of attaching or detaching a waste liquid tank because deposition of ink in a discharged ink dropping section X in a waste liquid housing container (waste liquid tank 100) exceeds a threshold, a compressed elastic spring member 112 recovers by detaching the waste liquid tank 100, which activates a scraping member 110 to scrape the deposited waste ink 105 in the waste liquid tank 100. That is, each time when a user detaches the detachable waste liquid tank 100 from the main apparatus, the scraping member 110 is operated upon attaching or detaching the waste liquid tank 100, and columns of waste ink locally depositing in the waste liquid dropping section are collapsed and the depositing ink can be prevented from jumping out from an upper end face of the waste liquid tank, and a user can easily handle the apparatus. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a waste liquid container and an image forming apparatus.

  In various image forming apparatuses such as printers, facsimiles, copiers, plotters, printer / facsimile / copier multifunction machines, etc. equipped with a liquid droplet ejection head for ejecting the recording liquid, A mechanism for maintaining and recovering the performance of the recording head to be ejected is indispensable. The main functions of this head performance maintenance and recovery mechanism are a cap function that covers with a highly-sealing cap member to prevent thickening and sticking of the recording liquid near the nozzle hole due to natural evaporation of ink, and a nozzle function. This is because the ejection failure due to the bubbles is recovered by discharging the recording liquid, or the ejection recovery function that sucks the recording liquid from the nozzle of the head through the cap function, and the cause that changes the flying state of the droplets attached to the nozzle surface And a wiping function for wiping off the remaining recording liquid.

  By performing such a performance maintaining and recovering operation of the head, a recording liquid that is not used for recording is discharged, and a waste liquid storage container (also referred to as a waste liquid tank) for storing the waste liquid of the recording liquid. ).

  If the waste liquid tank is full and overflows, the inside of the device will be adversely affected, so it has been reported that a waste tank full tank detection device is provided to detect that the waste liquid tank is full. (For example, refer to Patent Documents 1 to 3).

  In addition, as a means to improve the ink storage capacity of the waste liquid tank as much as possible, the liquid waste liquid is absorbed and stored by the absorbing member, and the waste liquid other than the liquid state is accumulated in the space and stored. A method of accommodating the two separately has been reported (see, for example, Patent Document 4).

JP 2007-160868 A JP 2000-203059 A JP 2006-224358 A JP 2006-137079 A

  By the way, in recent image forming apparatuses using ink, the use of pigment-based inks using organic pigments, carbon black or the like as colorants has been studied or put into practical use in order to enable high-quality printing on plain paper. However, unlike dyes, pigments are not soluble in water, and are usually used as water-based inks in a state where pigments are mixed with a dispersant, dispersed, and stably dispersed in water.

  Such a pigment-based ink generally has a higher viscosity than a dye-based ink, causing a problem due to the high viscosity. That is, the waste liquid (waste ink) of high-viscosity ink is easy to thicken, and when the thickened waste liquid is dropped directly onto the absorbing member, the waste liquid is likely to accumulate on that portion, and the waste liquid is not absorbed by the absorbing member.

  Therefore, in the conventional waste liquid storage container, the waste ink may overflow from the inlet before the absorbing member is used up. In addition, when full tank detection is performed because the waste ink does not rotate around the entire absorbing member, if the full tank detection part and the waste ink input part are separated, the waste ink overflows without being able to detect the full tank. There is a problem that there are things.

  The present invention has been made in view of the above problems, and a waste liquid storage container that can store waste liquid without overflowing even in a waste liquid storage container that stores waste liquid of high-viscosity recording liquid, and an image including the waste liquid storage container An object is to provide a forming apparatus.

  According to a first aspect of the present invention, there is provided a liquid droplet discharge head for discharging liquid droplets, a means for discharging ink from the liquid droplet discharge head, and the discharged ink. In the image forming apparatus including the detachable waste liquid tank means for storing the ink, the image forming apparatus has a scraping member for scraping off the accumulation portion of the ink discharged to the waste liquid tank, and the ink scraping member is attached to and detached from the waste liquid tank. It is characterized by being operable during operation.

  According to a second aspect of the present invention, in the waste liquid container for the image forming apparatus according to the first aspect, the scraping member can be operated in conjunction with an attaching / detaching operation of the waste liquid tank.

  According to a third aspect of the present invention, in the waste liquid storage container for the image forming apparatus according to the first or second aspect, an ink height unit that detects a height of ink accumulated in the waste liquid tank, and the ink height And determining means for determining that the scraping operation is to be performed when the accumulated ink height detected by the means is greater than or less than a threshold value.

  According to a fourth aspect of the present invention, in the waste liquid storage container for the image forming apparatus according to the first or second aspect, analogy means for inferring an amount of the waste liquid discharged into the waste liquid tank from an operation related to the discharge; Further, the present invention is characterized in that it has a determining means for determining that the scraping operation is activated when the waste liquid amount count value of the analogizing means is equal to or greater than or less than a threshold value.

  According to a fifth aspect of the present invention, in the waste liquid container for the image forming apparatus according to the third or fourth aspect, the waste liquid tank when the scraping operation is determined to be necessary in the determination of the threshold value by the determination unit. And a notification means for instructing the attaching / detaching operation.

  According to a sixth aspect of the present invention, in the waste liquid container for an image forming apparatus according to any one of the first to fifth aspects, the scraping member contains a water repellent material.

  An image forming apparatus according to a seventh aspect is an image forming apparatus that forms an image on a recording medium by ejecting liquid droplets of a recording liquid, and the waste liquid tank according to any one of the first to sixth aspects. It is characterized by comprising.

  According to the present invention, the ink scraping member is activated during the operation of attaching / detaching the waste liquid tank, so that when the user removes the attachable / detachable waste liquid tank from the main body, the waste ink column is locally accumulated below the waste liquid droplets. Therefore, the accumulated ink can be prevented from jumping out from the upper end surface of the waste liquid tank, so that the user can easily handle it. Further, the ink column is prevented from reaching the upper end surface of the waste liquid tank, and the life of the waste liquid tank can be suppressed.

  The best mode for carrying out the present invention will be described below with reference to the embodiments shown in the drawings.

  FIG. 1 is a perspective view of a printer, which is an example of an image forming apparatus according to the present invention, including a waste liquid tank that is a waste liquid storage container according to the present invention as viewed from the front side. The image forming apparatus includes an apparatus main body 1, a paper feed tray 2 for loading paper loaded in the apparatus main body 1, and a discharge for stocking paper on which an image is recorded (formed) mounted on the apparatus main body 1. The apparatus main body 1 further includes a cartridge loading portion 6 that protrudes forward from the front surface 4 and is lower than the upper surface 5 on one end side of the front surface 4 of the apparatus main body 1. An operation unit 7 such as operation keys and a display is arranged on the upper surface of the display. An ink cartridge 10 is replaceably attached to the cartridge loading unit 6 and has a front cover 8 that can be opened and closed.

  Next, the mechanism of this image forming apparatus will be described with reference to FIGS. FIG. 2 is a schematic configuration diagram for explaining the overall configuration of the mechanism unit, and FIG. 3 is a plan view for explaining a main part of the mechanism unit. A carriage 33 is slidably held in the main scanning direction by a guide rod 31 which is a guide member horizontally mounted on the left and right side plates 21A and 21B constituting the frame 21, and a stay 32. Move and scan in the direction indicated by the arrow (carriage scanning direction: main scanning direction).

  In the carriage 33, a plurality of recording heads 34 including ink jet heads that are droplet discharge heads for discharging recording liquid droplets (ink droplets) are arranged in a direction crossing a plurality of nozzles in the main scanning direction. The ink droplet ejection direction is directed downward. The recording head 34 includes, for example, a recording head 34y that discharges yellow (Y) droplets, a recording head 34m that discharges magenta (M) droplets, a recording head 34c that discharges cyan (C) droplets, and a black And a recording head 34b for discharging (Bk) droplets. The “recording head 34” does not distinguish between colors. The head configuration is not limited to these examples, and it may be configured using one or a plurality of recording heads having one or a plurality of nozzle rows that eject droplets of one or a plurality of colors. In this image forming apparatus, a high-viscosity recording liquid of 8 mPa · s to 20 mP · s is used as ink.

  The droplet discharge head constituting the recording head 34 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 caused by a temperature change. A shape memory alloy actuator using a change, an electrostatic actuator using an electrostatic force, or the like provided as energy generating means for discharging droplets can be used.

  In addition, the carriage 33 is equipped with sub tanks 35y, 35m, 35c, and 35k for each color for supplying the recording liquid of each color to each recording head 34 (referred to as “sub tank 35” when colors are not distinguished). Yes. Recording liquid is supplied to the sub tank 35 from the ink cartridges 10 of the respective colors (referred to as “ink cartridges 10y, 10m, 10c, and 10k” when different colors are distinguished) through the recording liquid supply tubes 37 of the respective colors. Like to do.

  Here, as shown in FIG. 3, the ink cartridge 10 is stored in the cartridge loading unit 6, and the cartridge loading unit 6 is provided with a supply pump unit 23 for feeding the recording liquid in the ink cartridge 10. It has been. The recording liquid supply tube 37 from the ink cartridge loading unit 6 to the sub tank 35 is fixed and held by the main body side holder 25 on the rear plate 21 </ b> C constituting the frame 21 in the middle of turning. Further, it is fixed on the carriage 33 by the fixing rib 26.

  On the other hand, as a paper feeding unit for feeding the papers 42 stacked on the paper stacking unit (bottom plate) 41 of the paper feed 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.

  As a transport unit for transporting the paper 42 fed from the paper feed unit on the lower side of the recording head 34, a transport belt 51 for transporting the paper 42 by electrostatic adsorption, and a paper feed unit The counter roller 52 for transporting the paper 42 fed through the guide 45 while sandwiching it between the transport belt 51 and the paper 42 fed substantially vertically upward are changed by approximately 90 ° and copied onto the transport belt 51. A conveyance guide 53 for adjusting the pressure and a tip pressure roller 55 urged toward the conveyance belt 51 by a pressing member 54. In addition, a charging roller 56 that is a charging unit for charging the surface of the conveyance belt 51 is provided.

  Here, the conveyance belt 51 is an endless belt, and is configured to be looped around the conveyance roller 57 and the tension roller 58 in the belt conveyance direction of FIG. The charging roller 56 is disposed so as to come into contact with the surface layer of the conveyor belt 51 and to be rotated by the rotation of the conveyor belt 51, and 2.5N is applied to both ends of the shaft as a pressing force.

  In addition, a guide member 61 is disposed on the back side of the conveyor belt 51 so as to correspond to a printing area by the recording head 54. The upper surface of the guide member 61 protrudes closer to the recording head 34 than the tangent line of the two rollers (the conveyance roller 57 and the tension roller 58) that support the conveyance belt 51. As a result, the conveyance belt 51 is pushed up and guided by the upper surface of the guide member 61 in the printing region, so that highly accurate flatness is maintained.

  Further, as a paper discharge unit for discharging the paper 42 recorded by the recording head 34, a separation claw 71 for separating the paper 42 from the transport belt 51, a paper discharge roller 72, and a paper discharge roller 73 are provided. A paper discharge tray 3 is provided below the paper discharge roller 72. Here, the height from between the paper discharge roller 72 and the paper discharge roller 73 to the paper discharge tray 3 is increased to some extent in order to increase the amount that can be stored in the paper discharge tray 3.

  A double-sided paper feeding unit 81 is detachably attached to the back surface of the apparatus body 1. The double-sided paper feed unit 81 takes in the paper 42 returned by the reverse rotation of the transport belt 51, reverses it, and feeds it again between the counter roller 52 and the transport belt 51. A manual paper feed unit 82 is provided on the upper surface of the duplex paper feed unit 81.

  Further, as shown in FIG. 3, a maintenance / recovery mechanism 91 for maintaining and recovering the state of the nozzles of the recording head 34 is disposed in the non-printing area on one side of the carriage 33 in the scanning direction.

  The maintenance and recovery mechanism 91 includes cap members (hereinafter referred to as “caps”) 92a to 92d (hereinafter referred to as “caps 92” when not distinguished from each other) for capping each nozzle surface of the recording head 34, and nozzle surfaces. A wiper blade 93 that is a blade member for wiping the ink, an empty discharge receiver 94 that receives a droplet when performing an empty discharge for discharging a droplet that does not contribute to recording in order to discharge the thickened recording liquid, and the empty discharge receiver 94 A wiper cleaner 95 that is integrally formed with the discharge receiver 94 and is a cleaning member for removing the recording liquid adhering to the wiper blade 93, and cleaner means that presses the wiper blade 93 against the wiper cleaner 95 side when the wiper blade 93 is cleaned. A cleaner roller 96 is provided.

  Then, the waste liquid of the recording liquid generated by the maintenance / recovery operation by the maintenance / recovery mechanism 91, the ink discharged to the cap 92, the ink attached to the wiper blade 93 and removed by the wiper cleaner 95, and the idle ejection to the idle ejection receiver 94 The discharged ink is discharged and stored in a waste liquid tank 100 which is a waste liquid storage container according to the present invention indicated by a virtual line in FIG.

  Further, as shown in FIG. 3, in the non-printing area on the other side in the scanning direction of the carriage 33, 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 98 for receiving the droplets is disposed, and the empty discharge receiver 98 is provided with an opening 99 and the like along the nozzle row direction of the recording head 34.

  Next, an outline of the control unit of the image forming apparatus will be described with reference to FIG. This figure is an overall block diagram of the control unit. The control unit 280 includes a CPU 281 that controls the entire apparatus, a ROM 282 that stores programs executed by the CPU 281 and other fixed data, a RAM 283 that temporarily stores image data, and the like, while the apparatus is powered off. And a non-volatile memory (NVRAM) 284 for holding data, an image processing for performing various signal processing and rearrangement on image data, and an ASIC 285 for processing input / output signals for controlling the entire apparatus. Yes.

  The control unit 280 also includes an I / F 286 for transmitting and receiving data and signals to and from the host, a head drive control unit 287 and a head driver 288 for controlling the drive of the recording head 34, and a main scanning motor 290. A main scanning motor driving unit 291 for driving the motor, a sub-scanning motor driving unit 293 for driving the sub-scanning motor 292, a maintenance / recovery mechanism driving unit 295 for driving the motor 294 of the maintenance / recovery mechanism 91, and waste liquid A detection signal from a full tank sensor 300 that detects the full tank 100, an I / O 296 for inputting detection signals from various sensors (not shown), and the like are provided. The control unit 280 is connected to an operation panel 297 (operation unit 7) for inputting and displaying information necessary for the apparatus.

  The control unit 280 receives print data and the like from the host side such as an information processing apparatus such as a personal computer, an image reading apparatus such as an image scanner, and an imaging apparatus such as a digital camera, via the cable or the network by the I / F 286.

  The CPU 281 reads and analyzes the print data in the reception buffer included in the I / F 286, performs necessary image processing, data rearrangement processing, and the like in the ASIC 285, and transfers the image data to the head drive control unit 287. To do. The generation of dot pattern data for image output may be performed by storing font data in the ROM 282, for example, or image data is developed into bitmap data by a host-side printer driver and transferred to this apparatus. You may do it.

  When the head drive control unit 287 receives image data (dot pattern data) corresponding to one row of the recording head 34, the dot pattern data for one row is serialized to the head driver 288 in synchronization with the clock signal. Data is transmitted, and a latch signal is transmitted to the head driver 288 at a predetermined timing.

  The head drive control unit 287 includes a ROM (which can also be configured by a ROM 282) storing pattern data of a drive waveform (drive signal), and a D / A converter for D / A conversion of drive waveform data read from the ROM. A waveform generation circuit including an A converter and a drive waveform generation circuit including an amplifier and the like are included.

  The head driver 288 also receives a clock signal from the head drive controller 287 and serial data as image data, and a latch circuit that latches the register value of the shift register with a latch signal from the head drive controller 287. A level conversion circuit (level shifter) that changes the output value of the latch circuit, an analog switch array (switch means) that is controlled to be turned on / off by the level shifter, and the like, and controls on / off of the analog switch array. In this way, a required drive waveform included in the drive waveform is selectively applied to the actuator means of the recording head 34 to drive the head.

  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 52 and conveyed, and further, the leading end is guided by the conveying guide 53 and pressed against the conveying belt 51 by the leading end pressing roller 55, and the conveying direction is changed by approximately 90 °.

  At this time, a positive output and a negative output are alternately repeated from the high-voltage power supply to the charging roller 56 by a control circuit (not shown), that is, an alternating voltage is applied, and a charging voltage pattern in which the conveying belt 51 alternates, that is, In the sub-scanning direction, which is the circumferential direction, plus and minus are alternately charged in a band shape with a predetermined width. When the sheet 42 is fed onto the conveyance belt 51 charged alternately with plus and minus, the sheet 42 is electrostatically attracted to the conveyance belt 51, and the sheet 42 is moved in the sub-scanning direction by the circular movement of the conveyance belt 51. Be transported.

  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.

  During printing (recording) standby, the carriage 33 is moved to the maintenance / recovery mechanism 91 side, the recording head 34 is capped by the cap member 92, and the nozzles are kept in a wet state to prevent ejection failure due to ink drying. To do. Further, the recording liquid is sucked from the nozzle by a suction pump (not shown) with the recording head 34 capped by the cap member 92 (referred to as “nozzle suction” or “head suction”), and the thickened recording liquid and bubbles are discharged. Perform recovery action. In addition, an idle ejection operation for ejecting ink not related to recording is performed before the start of recording or during recording. As a result, the stable ejection performance of the recording head 34 is maintained.

  At this time, the liquid waste liquid generated by the suction and the like of the maintenance and recovery mechanism 91 is discharged from a waste liquid tube connected to a suction pump (not shown) to the waste liquid tank 100. Further, the ink that adheres to the wiper blade 93 and is removed by the wiper cleaner 95 is scraped off by the idle discharge receiver 94 to increase the viscosity, and similarly, the ink that has been idlely discharged to the idle discharge receiver 94 also increases in viscosity. The liquid is discharged from the lower part of the discharge receiver 94 to the waste liquid tank 100.

  An embodiment of the waste liquid tank according to the present invention will be described with reference to FIGS.

  First, a conventional waste liquid tank 100 will be described with reference to FIGS. 5 to 7 for comparison. FIG. 5 is a sectional side view of the conventional waste liquid tank 100 (initial stage), FIG. 6 is a sectional side view of the conventional waste liquid tank 100 (when used under general conditions), and FIG. FIG. 2 is a cross-sectional side view (showing a point to be solved by the present invention when used under conditions where deposition is easy).

  As shown in FIG. 5, the ink 103 discharged from the ink discharge head 101 by the suction means 102 is dropped into the waste liquid tank 100 that stores the waste ink 105 through the ink discharge tube 104. In the figure, A indicates a discharged ink dropping portion.

  When used under general conditions, the ink 105 discharged as shown in FIG. 6 is partly absorbed by the waste ink absorber 106 while spreading in the waste liquid tank 100, and partly in the waste liquid tank 100. It accumulates uniformly on the bottom surface and does not deposit locally on the discharged ink dropping portion B.

  On the other hand, FIG. 7 shows a state during use under conditions where deposition is easy. Conditions that are likely to deposit refer to a use environment where high temperature and low humidity are used, or the waste ink 105 is not periodically discharged. In such a case, the droplets of the discharged ink 103 easily accumulate locally at the discharged ink dropping portion C, and if left untreated, the accumulated waste ink 105 progresses until it jumps out from the upper part of the waste liquid tank 100. Resulting in. If so, the amount of waste ink sucked by the waste ink absorber 106 is small, and the waste ink absorber 106 cannot be effectively used, and the life of the waste liquid tank 100 is reached.

  A schematic explanatory diagram of one embodiment of the present invention is shown in FIG. FIG. 8 shows a state before the waste liquid tank 100 is attached to an image printing apparatus (for example, a printer as shown in FIG. 1) which is the main body of the apparatus, (a) is a top view and (b) is a side sectional view. In the waste liquid tank 100, a waste ink absorber 106, a scraped ink scraping member 110 for scraping off the deposited ink, a stick 111 having a stretchable structure supporting the scraping member 110, and scraping. An elastic (spring) member 112 that urges the member 110, a rib pressing portion 113 that presses the scraping portion against the elastic spring member 112 when the waste liquid tank 100 is mounted on the main body, and a scraping member that is pressed by the rib pressing portion 113 110 rib portions 114 are provided. The rib portions 114 are provided at both ends of the scraping member 110. The scraping member 110 can be made to contain a water repellent material, or the surface can be coated with a water repellent material, and it is preferable to eliminate or reduce ink adhesion.

  FIG. 9 shows a state immediately after the waste liquid tank 100 is mounted on the apparatus main body (not shown) (at the start of use). When the waste liquid tank 100 is inserted in the direction of the arrow shown in FIG. 8, the rib portions 114 provided at both ends of the scraping portion 110 come into contact with the rib pressing portions 113 in the apparatus main body, and the scraping member 110 is an elastic spring member. It is urged to 112 side, and it will be in the state of use start.

  FIG. 10 shows a state immediately before the waste ink 105 is accumulated in the ink dropping part X in the waste liquid tank 100 and exceeds the threshold value (a scraping operation instruction is issued), and FIG. The ink accumulation in part X exceeds the threshold value, and the waste liquid tank 100 is removed from the main unit according to the waste liquid attachment / detachment instruction. The compressed elastic spring member 112 is restored by removing the waste liquid tank 100, and the scraping part 110 scrapes the waste ink 105 accumulated in the waste liquid tank 100 by the action.

  FIG. 12 shows a state in which the waste liquid tank 100 is remounted in the apparatus main body after the waste liquid tank 100 is removed. As the accumulated waste ink 105 is agitated, the ink accumulation height can be lowered, so that the waste ink can still be discharged into the waste liquid tank 100 and the waste liquid tank 100 can be used effectively. It becomes.

  FIG. 13 is a schematic configuration diagram including a detection sensor 115 such as a transmission type optical sensor that detects the height of the waste ink 105 accumulated in the waste liquid tank 100. FIG. 14 shows an operation flow when the apparatus having the configuration is operated.

  As shown in the flowchart of FIG. 14, first, it is confirmed whether the waste liquid tank 100 is mounted in the apparatus main body (step 1). If the waste liquid tank 100 is not attached (NO in step 1) in step 1, an error is displayed (step 1a). If it is attached to the main body of the apparatus (YES in step 1), whether the detection value of the detection sensor 115 that detects the height of the waste ink 105 accumulated in the waste liquid tank 100 is greater than or less than a threshold value. Is confirmed using the detection sensor 115 (step 2). If the height of the waste ink 105 accumulated in step 2 is “less than the threshold value”, the ink discharge operation from the ink ejection head 101 that generates the waste ink 105 is OK, and the discharge operation is performed. If the height of the waste ink 105 deposited in step 2 is “threshold or more”, notification (display) is made using, for example, a notification means so as to remove the waste liquid tank 100 from the apparatus main body (step 3). In accordance with the instruction, it is confirmed whether or not the waste liquid tank 100 has been removed, and then it is confirmed that it will be remounted (steps 4 and 5). If the waste tank 100 is attached (YES in step 5), the ink discharge operation is performed from the ink discharge head 101. At this time, as a method for detecting that the waste liquid tank is attached or detached, it may be detected by ON / OFF of a mechanical switch, detection by a non-contact sensor, presence / absence of electrical connection by contact, or the like.

Further, instead of using the above-described determination whether the height of the accumulated waste ink is equal to or higher than the threshold value, a means for analogizing the amount of waste liquid discharged into the waste liquid tank 100 from the operation related to the discharge is provided. It is also possible to make a determination to activate the scraping operation as a condition for determining whether a detection value (for example, a count value using a counter) is greater than or less than a threshold value. That is, if the waste ink amount in the A operation accompanied by the ink discharging operation is Ha, the waste ink amount in the B operation accompanied by the ink discharging operation is Hb, and the threshold for the determination is Hs, the ink discharging operation A is a If the total amount of waste ink when the ink discharge operation B is performed b times is Ht, the following relational expression is established.
Ht = Ha × a + Hb × b
If the value of Ht is less than the threshold value when Ht <Hs with respect to the determination threshold value Hs, the ink discharge operation from the ink ejection head 101 is determined to be OK, and if Ht ≧ Hs, the value is equal to or greater than the threshold value. It can be determined and notified to remove the waste liquid tank 100 from the apparatus main body.

Furthermore, when the discharging operation is performed with respect to the relational expression under the condition that the deposition is likely to proceed, it may be calculated by multiplying by a coefficient. That is, correction is performed by multiplying by a coefficient. For example, when the discharge operation is performed in an environment with low humidity, the coefficient is 1.2, and the ink discharge operation A is performed a times (with the internal humidity being low). The total amount of waste ink when the ink discharge operation B is performed b times (the number of times the ink discharge operation is performed in a state where the humidity is low is b ′ times) is Ht ′.
Ht ′ = Ha × ((a−a ′) + 1.2 × a ′) + Hb × ((b−b ′) + 1.2 × b ′)
Thus, this value can be used to determine whether the threshold value Hs is large or small.

  The coefficient at this time may be multiplied by a coefficient larger than 1 not only when the humidity is low but also when the temperature is high or when the frequency of use is low. Conversely, a coefficient smaller than 1 may be applied when the humidity is high and the usage frequency is high.

  Further, for example, when used in an image forming apparatus, the panel portion may be provided with a liquid crystal screen or the like, and may be configured to display when the waste liquid tank needs to be replaced. Further, a display for instructing replacement of the waste liquid tank may be displayed on the screen of a computer connected to the image forming apparatus main body. Alternatively, the image may be displayed by blinking a light emitting element such as an LED provided in the image forming apparatus.

  As described above, the present invention provides an image forming apparatus that includes a droplet discharge head that discharges droplets, a unit that discharges ink from the discharge head, and a detachable waste liquid tank unit that stores the discharged ink. In the apparatus, there is proposed a waste liquid tank having a scraping member for scraping off the ink accumulation portion discharged to the waste liquid tank, and the ink scraping member is activated when the waste liquid tank is attached or detached. As a result, when the user removes the detachable waste liquid tank from the main body, the waste ink column that locally accumulates below the waste droplets is scraped (defeated), thus preventing the accumulated ink from jumping out from the upper end surface of the waste liquid tank. This makes it easier for the user to handle. Further, the ink column is prevented from reaching the upper end surface of the waste liquid tank, and the life of the waste liquid tank can be suppressed.

  According to the present invention, in the waste liquid tank having a scraping member for scraping off the ink accumulation portion discharged to the waste liquid tank, the ink scraping member operates in conjunction with the attaching / detaching operation of the waste liquid tank. Suggest a tank. As a result, the scraping operation can be performed without providing a drive source for driving the accumulated ink portion scraping member.

  According to another aspect of the present invention, there is provided a means for detecting the height of ink accumulated in the waste liquid tank, and the waste liquid tank is characterized in that the scraping operation is performed when the accumulated ink height is equal to or higher than a threshold value. Propose. As a result, it is possible to detect that the waste ink column that locally accumulates below the waste droplets has reached a set height, and to determine the timing for performing the scraping operation of the deposited ink.

  The present invention further includes means for analogizing the amount of waste liquid discharged into the waste liquid tank from the operation related to the discharge, and performing the determination to activate the scraping operation when the count value is greater than or less than a threshold value. A waste liquid tank is proposed. As a result, since the amount of waste ink can be estimated from the ink discharge operation, it is possible to determine the timing at which the accumulated ink scraping operation is performed without providing a new sensor or the like.

  In addition, the present invention proposes a waste liquid tank characterized by comprising a notification means for instructing a detachment operation of the waste liquid tank when it is determined that the scraping operation is necessary in the threshold value determination. Accordingly, the user can perform the operation of attaching and detaching the waste liquid tank in accordance with the notification, and perform the operation of scraping the accumulated ink from the waste liquid tank.

  Furthermore, the present invention proposes a waste liquid tank characterized in that a water repellent material is contained in a scraping member for scraping off the ink accumulation portion discharged to the waste liquid tank. Thereby, the ink adhesion to the scraping member can be suppressed, and the function deterioration of the scraping member can be suppressed.

1 is a perspective view showing a printer as an example of an image forming apparatus according to the present invention when viewed from the front side. Schematic configuration diagram explaining the overall configuration of the mechanism of the image forming apparatus Plan view of the main part Block diagram of the entire control unit of the image forming apparatus Cross-sectional side view of a conventional waste liquid tank (initial) Cross-sectional side view of a conventional waste liquid tank (when used under general conditions) Cross-sectional side view of a conventional waste liquid tank (when used under conditions that tend to accumulate) BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic explanatory drawing of one Example of this invention, (a) is a top view, (b) is side sectional drawing. The figure which shows the state immediately after mounting the waste liquid tank to the main body of the equipment (at the start of use) The figure which shows the state just before waste ink accumulates in an ink dripping part in a waste liquid tank, and exceeds a threshold value (a scraping operation instruction | indication comes out) The figure which shows the state which removed the waste liquid tank from the main body apparatus according to the waste liquid attachment / detachment instruction | indication, when the ink accumulation of an ink dripping part exceeded a threshold value within a waste liquid tank The figure which shows the state where the waste liquid tank was remounted in the device body again after removing the waste liquid tank Schematic configuration diagram equipped with a detection sensor that detects the height of waste ink accumulated in the waste liquid tank The flowchart figure which shows operation | movement of the apparatus of the structure of FIG.

Explanation of symbols

1: Device main body 2: Paper feed tray 3: Paper discharge tray 6: Cartridge loading unit 7: Operation unit 8: Front cover 10: Ink cartridge 23: Supply pump unit 33: Carriage 34: Recording head 35: Sub tank 41: Paper stacking Unit 42: Paper 43: Paper feeding roller 51: Conveying belt 56: Charging roller 81: Double-sided paper feeding unit 82: Manual paper feeding unit 91: Maintenance recovery mechanism 100: Waste liquid tank 101: Ink ejection head 102: Suction means 103: Ink 104: Ink discharging tube 105: Waste ink 106: Waste ink absorber 110: Deposited ink scraping member 111: Bar portion 112: Elastic spring member 113: Rib pushing portion 114: Rib portion 115: Detection sensor 280: Control portion 281: CPU
287: Head drive control unit A, B, C, X: Discharged ink dropping unit

Claims (7)

A droplet discharge head for discharging droplets;
Means for discharging ink from the droplet discharge head;
In the image forming apparatus provided with a detachable waste liquid tank means for storing the discharged ink,
A scraping member for scraping off the accumulated portion of the ink discharged to the waste liquid tank;
A waste liquid storage container for an image forming apparatus, wherein the ink scraping member is operable during an operation of attaching and detaching the waste liquid tank. The waste liquid container for the image forming apparatus according to claim 1,
A waste liquid storage container for an image forming apparatus, wherein the scraping member can be operated in conjunction with an attachment / detachment operation of the waste liquid tank. The waste liquid container for an image forming apparatus according to claim 1 or 2,
Ink height means for detecting the height of ink deposited in the waste liquid tank;
A waste liquid container for an image forming apparatus, comprising: a determination unit configured to determine that the scraping operation is activated when a height of accumulated ink detected by the ink height unit is equal to or greater than a threshold value. The waste liquid container for an image forming apparatus according to claim 1 or 2,
Analogy means for inferring the amount of waste liquid discharged into the waste liquid tank from the operation related to discharge;
A waste liquid container for an image forming apparatus, comprising: determination means for performing a determination to activate the scraping operation when the waste liquid amount count value of the analogizing means is equal to or greater than a threshold value. In the waste liquid container for the image forming apparatus according to claim 3 or 4,
A waste liquid storage container for an image forming apparatus, comprising: a notification means for instructing an attachment / detachment operation of the waste liquid tank when it is determined that a scraping operation is necessary in the determination of the threshold value by the determination means. The waste liquid container for an image forming apparatus according to any one of claims 1 to 5,
A waste liquid container for an image forming apparatus, wherein the scraping member contains a water repellent material. 7. An image forming apparatus for forming an image on a recording medium by discharging recording liquid droplets, comprising the waste liquid tank according to any one of claims 1 to 6. Forming equipment.