JP2008279644A - Maintenance recovery method, maintenance recovery mechanism, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a maintenance / recovery method, a maintenance / recovery mechanism, and an image forming apparatus capable of preventing color mixing without increasing a useless amount of ink for a user and without newly adding parts.
According to a first aspect of the present invention, there is provided a first recovery step in which a nozzle surface of a droplet discharge head is covered with a cap, and suction means connected to the cap is operated to perform suction from the nozzle through the cap. A second step of separating the cap from the nozzle surface, and supplying a predetermined drive signal generated by the drive signal generating means to the droplet discharge head so that the droplet is not discharged, and the meniscus position in the nozzle is set outside the nozzle. And a third step of cleaning the periphery of the nozzle by the cleaning unit, and a fourth step of operating the suction unit to suck the ink in the cap.
[Selection] Figure 6

Description

  The present invention relates to a maintenance / recovery method, a maintenance / recovery mechanism, and an image forming apparatus, and more particularly to a method for minimizing ink consumption and preventing color mixing during a maintenance / recovery operation.

  In an image forming apparatus that supplies a recording liquid from each sub tank to a single droplet discharge head that discharges droplets of different colors, the nozzle surface of the droplet discharge head is capped with a single cap and nozzle suction is performed to recover. When the operation is performed, if the cap is removed after the nozzle is sucked, different color inks exist on the nozzle surface, so that different color inks may be sucked into the nozzles due to the negative pressure inside the sub tank, resulting in color mixing. In order to prevent such color mixture, several proposals have been made conventionally.

In Patent Document 1 as one of them, ink is supplied until the same amount is filled in the sub-tanks of different colors before suctioning the nozzles, the absolute value of the negative pressure in the sub-tank is lowered, and the color mixing is performed by making the values equal. It is preventing. Furthermore, after removing the cap, ink droplets are ejected from the nozzles to prevent color mixing. Further, in Patent Document 2, the ink remaining on the wiper after the wiping of the nozzle surface and dust are absorbed by the porous member, so that different color inks do not exist on the nozzle surface and color mixing is prevented. ing.
JP 2005-144939 A Japanese Patent Application Laid-Open No. 07-068791

  By the way, in the image forming apparatus, in order to increase the satisfaction of the user of the apparatus, it is necessary to reduce the amount of ink consumed other than printing as much as possible. Further, it is necessary to reduce the number of parts in order to reduce the cost of the apparatus. However, in Patent Document 1, color mixing is prevented by ejecting ink droplets from the nozzle after the nozzle is sucked and the cap is removed during the head recovery operation. That is, since the ink consumed here is not used for printing, it is a wasteful ink consumption for the user. If the user purchases ink that has not been used for printing and is discarded, the user's satisfaction is lowered. Further, if an extra amount of ink that is discarded by the device manufacturer is stored in the ink cartridge, the user satisfaction is not lowered, but the cost of the device manufacturer is increased. In Patent Document 2, a porous member is used to absorb the remaining ink and dust on the wiper into the porous member. However, since this is added as a part, the cost of the apparatus is increased. End up.

  The present invention is for solving these problems, and is a maintenance and recovery method, a maintenance and recovery mechanism, and an image that can prevent color mixing without increasing the amount of ink that is wasted for the user and without adding new parts. An object is to provide a forming apparatus.

  In order to solve the above problems, the maintenance and recovery method of the present invention covers the nozzle surface of the droplet discharge head with a cap, and operates the suction means connected to the cap to perform suction from the nozzle through the cap. A first step, a second step of separating the cap from the nozzle surface, and a predetermined drive signal generated by the drive signal generating means is supplied to the droplet discharge head so as not to discharge the droplet. A third step of moving the meniscus position to the outside of the nozzle, a third step of cleaning the periphery of the nozzle by the cleaning unit, and a fourth step of operating the suction unit to suck the ink in the cap. There are features. Therefore, since the nozzle is pressurized after the nozzle suction during the maintenance and recovery operation, it is possible to prevent inks of different colors on the nozzle surface from being drawn into the nozzle by the negative pressure in the sub tank and causing color mixing. The amount of wasted ink can be reduced.

  In addition, the maintenance and recovery mechanism as another invention includes a suction unit that performs suction from the nozzle side of the droplet discharge head in order to perform a recovery operation of the droplet discharge head, and a droplet after the suction is performed by the suction unit. Cleaning means for supplying the predetermined drive signal generated by the drive signal generating means for moving the meniscus position in the nozzle outside the nozzle without discharging to the droplet discharge head and cleaning the recording liquid moved to the outside of the nozzle It is characterized by comprising. Therefore, after the nozzle is sucked during the maintenance and recovery operation, the ink droplets are not ejected and cleaning is performed after the drive signal is input so that the meniscus moves to the outside of the nozzle. It is possible to prevent the occurrence of color mixing due to being drawn into the nozzle by the negative pressure, and it is possible to reduce the amount of wasted ink.

  Furthermore, an image forming apparatus according to another invention includes a plurality of nozzle rows that discharge droplets of different colors, a pressure chamber that communicates with the nozzle rows, and a droplet discharge device that includes a pressure generating unit that changes the volume of the pressure chamber. It is characterized in that it comprises a head, drive signal generating means for generating a drive signal, and a plurality of sub tanks for supplying recording liquids of the respective colors to the droplet discharge head, and further having the maintenance and recovery mechanism. Therefore, it is possible to provide an image forming apparatus capable of preventing color mixing at the time of maintenance and recovery, maintaining print quality and suppressing wasteful ink consumption.

  In addition, by having a pressurizing unit that contracts the pressure chamber so that the position of the meniscus is moved outside the nozzle without ejecting the droplet, the ink droplet is not ejected after the nozzle suction during the maintenance recovery operation. The pressure chamber is shrunk by the pressurizing means so that it moves to the outside of the nozzle, and the pressure chamber is pressurized, so that different color ink on the nozzle surface is drawn into the nozzle by the negative pressure in the sub tank, and color mixing occurs. Can be prevented.

  Furthermore, the pressure generating means is preferably a piezoelectric element such as a piezo.

  According to the maintenance and recovery method of the present invention, after performing suction from the nozzle side of the droplet discharge head to perform the recovery operation of the droplet discharge head, the meniscus position in the nozzle is set to the outside of the nozzle without discharging the droplet. A predetermined drive signal generated by the drive signal generation means for moving the recording liquid is supplied to the droplet discharge head, and the recording liquid moved to the outside of the nozzle is cleaned. Therefore, it is possible to prevent color mixing that occurs when inks of different colors on the nozzle surface are drawn into the nozzles by the negative pressure in the sub tank, and the amount of wasted ink can be reduced.

  FIG. 1 is a perspective view showing the configuration of the image forming apparatus of the present invention. An ink jet recording apparatus as an example of the image forming apparatus shown in FIG. 1 includes an apparatus main body 10, a paper feed tray 11 for loading paper mounted on the apparatus main body 10, and an image recorded on the apparatus main body 10. A paper discharge tray 12 for stocking paper is provided. An upper surface cover 13 is provided on the upper side of the apparatus main body 10 so as to be openable and closable. Further, one end of the front surface 14 of the apparatus main body 10 protrudes forward from the front surface 14 and has a cartridge loading portion 15 at a position lower than the upper surface cover 13. An operation unit 16 such as a display is arranged. The cartridge loading unit 15 includes a front cover 17 that can be opened and closed on the front surface thereof. By opening the front cover 17, the ink cartridge 18 that is a recording liquid cartridge as a liquid replenishing unit can be attached and detached. Yes.

  FIG. 2 is a schematic cross-sectional view showing the configuration of the mechanism portion in the image forming apparatus of the present invention. FIG. 3 is a plan view showing the main configuration of the mechanism in the image forming apparatus of the present invention. The mechanism of an ink jet recording apparatus, which is an example of the image forming apparatus shown in both figures, is capable of sliding the carriage 21 in the main scanning direction by a guide rod 19 and a stay 20 which are guide members horizontally mounted on left and right side plates (not shown). 3 and is moved and scanned in the carriage main scanning direction (arrow direction) in FIG. 3 by a main scanning motor (not shown). The carriage 21 has a recording head 22 composed of four ink jet heads for ejecting ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (Bk). They are arranged in a direction crossing the main scanning direction, and are mounted with the ink droplet ejection direction facing downward. As the ink-jet head constituting the recording head 22, a piezoelectric actuator such as a piezoelectric element, a thermal actuator that utilizes 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. A shape memory alloy actuator to be used, an electrostatic actuator using an electrostatic force, etc. can be used as energy generating means for ejecting ink. Here, a piezoelectric actuator (piezoelectric element) is used as the energy generating means. It is equipped with the head.

  Further, the carriage 21 is equipped with a sub tank 23 that is a liquid container of each color for supplying ink of each color to the recording head 22. Ink is replenished and supplied to the sub tank 23 from the ink cartridge 18 of FIG. Here, the ink cartridge 18 contains ink of each color of yellow (Y), cyan (C), magenta (M), and black (Bk) corresponding to each color. The sub tank 23 for supplying ink to the recording head 22 and the ink cartridge 18 for supplying ink to the sub tank 23 to replenish ink constitute an ink supply device as a recording liquid supply device.

  On the other hand, as a paper feeding unit for feeding the papers 26 stacked on the paper stacking unit (pressure plate) 25 of the paper feed tray 12, the feeding of the half-moon roller that separates and feeds the papers 26 from the paper stacking unit 25 one by one. A separation pad 28 made of a material having a large friction coefficient is provided opposite to the paper roller 27, and this separation pad 28 is urged toward the paper feed roller 27 side.

  Then, as a transport unit for transporting the paper 26 fed from the paper feed unit below the recording head 22, a transport belt 29 for electrostatically attracting and transporting the paper 26, and a paper feed unit The counter roller 31 for transporting the paper 26 fed through the guide 30 with the transport belt 29 sandwiched between the counter roller 31 and the paper 26 fed substantially vertically upward is changed by about 90 ° and copied onto the transport belt 29. A conveying guide 32 for adjusting the pressure and a tip pressure roller 34 urged toward the conveying belt 29 by a pressing member 33. In addition, a charging roller 35 that is a charging unit for charging the surface of the conveyance belt 29 is provided.

  Here, the conveyance belt 29 is an endless belt, and is configured to be looped around the conveyance roller 36 and the tension roller 37 and to circulate in the belt conveyance direction of FIG. The charging roller 35 is disposed so as to come into contact with the surface layer of the conveyor belt 29 and rotate following the rotation of the conveyor belt 29, and applies 2.5N to both ends of the shaft as a pressing force.

  Further, a guide member 38 is disposed on the back side of the conveyor belt 29 in correspondence with the printing area by the recording head 22. The upper surface of the guide member 38 protrudes closer to the recording head 22 than the tangent line between the conveying roller 36 and the tension roller 37, which are two rollers that support the conveying belt 29. As a result, the conveyance belt 29 is pushed up and guided by the upper surface of the guide member 38 in the printing region, so that high-precision flatness is maintained.

  Further, as a paper discharge unit for discharging the paper 26 recorded by the recording head 22, a separation claw 39 for separating the paper 26 from the conveyance belt 29, a paper discharge roller 40, and a paper discharge roller 41 are provided. A paper discharge tray 12 is provided below the paper discharge roller 40. Here, the height from the discharge roller 40 and the discharge roller 41 to the discharge tray 12 is increased to some extent in order to increase the amount that can be stored in the discharge tray 12.

  A double-sided paper feeding unit 42 is detachably attached to the back surface of the apparatus main body 10. The double-sided paper feeding unit 42 takes in the paper 26 returned by the reverse rotation of the transport belt 29, reverses it, and feeds it again between the counter roller 31 and the transport belt 29. A manual paper feed unit 43 is provided on the upper surface of the duplex paper feed unit 42.

  Further, as shown in FIG. 3, in one non-printing area of the carriage 21 in the scanning direction, a maintenance / recovery mechanism 44 that is a reliability maintaining means for maintaining and recovering the nozzle state of the recording head 22 is arranged. An empty discharge receiving member 45 is arranged in the other non-printing area. The maintenance / recovery mechanism 44 includes cap members 46a, 46b, 46c, and 46d that are capping means for capping the nozzle surface of the recording head 22, a wiper blade 47 that is a wiping means for wiping the nozzle surface, A discharge receiving member 48 and the like are provided.

  Next, the configuration of the maintenance and recovery mechanism in FIG. 3 will be described with reference to FIGS. 4 and 5. 4 is a plan view showing the configuration of the capping means of the maintenance / recovery mechanism, and FIG. 5 is a front view showing the configuration of the drive mechanism of the capping means of the maintenance / recovery mechanism. The frame 81 includes a cap holder 82 including two cap holders 82a, 82b, 82c, and 82d, an empty discharge receiving member 83, a wiper blade 84 that is a wiping member including an elastic body as a cleaning unit, and a carriage lock 85. Are held up and down. The cap holders 82a, 82b, 82c and 82d hold caps 86 including caps 86a, 86b, 86c and 86d for capping the nozzle surfaces of the respective recording heads. Here, the tube pump 88 which is a suction means is connected to the cap 86a held by the cap holder 82a closest to the printing area through the tube 87, and the tube pump 88 is not connected to the other cap 86b. That is, only the cap 86a is a recovery and moisture retention cap, and the other caps 86b, 86c, 86d are merely moisture retention caps. Therefore, when performing the recovery operation of the recording head or the ink supply operation to the sub tank, the recording head is selectively moved to a position where it can be capped by the cap 86a. Further, a cam shaft 89 is rotatably disposed below the cap holders 82a, 82b, 82c, and 82d, and a cap cam for raising and lowering the cap holders 86a, 86b, 86c, and 86d is disposed on the cam shaft 89. 90a, 90b, 90c, 90d, a wiper cam 91 for raising and lowering the wiper blade 84, and a carriage lock cam 93 for raising and lowering the carriage lock 85 via the carriage lock arm 92 are provided. Further, a wiper cleaner 94 for cleaning the wiper blade 84 can be swung in the direction indicated by an arrow on the print area side of the wiper blade 84 and is urged in a direction away from the wiper blade 84 by a spring (not shown). The camshaft 89 is provided with a wiper cleaner cam 95 for swinging the wiper cleaner 94. Here, the cap 86 is moved up and down by the cap cams 90a, 90b, 90c, and 90d. The wiper blade 84 is moved up and down by the wiper cam 91. When the wiper cleaner 94 is lowered, the wiper cleaner 94 is advanced, and the wiper blade 84 is lowered while being sandwiched between the wiper cleaner 94 and the empty discharge receiving member 83, whereby the ink attached to the wiper blade 84 is removed. The empty discharge receiving member 83 is scraped off. The carriage lock 85 is urged upward (in the lock direction) by a compression spring (not shown) and is raised and lowered by the carriage lock arm 92. In order to rotationally drive the tube pump 88 and the cam shaft 89, the rotation of the motor 96 is engaged with the motor gear 97 provided on the motor shaft 96a and the pump gear 98 provided on the pump shaft 88a of the tube pump 88 is meshed. An intermediate gear 102 having a one-way clutch 101 is engaged with an intermediate gear 99 integrated with 98 via an intermediate gear 100, and an intermediate gear 103 coaxial with the intermediate gear 102 is connected to a camshaft 105 via an intermediate gear 104. A fixed cam gear 106 is engaged. The cam shaft 89 is provided with a home position sensor cam 107 for detecting the home position. When the cap 86 is moved to the lowermost end by a home position sensor (not shown) provided in the maintenance / recovery mechanism. A home position lever (not shown) is operated, the sensor is opened, and the home position of the motor 96 (other than the tube pump 88) is detected. When the power is turned on, the position moves up and down (up and down) regardless of the position of the cap 86 (cap holder 82), the position is not detected until the movement starts, and the position is determined after detecting the home position of the cap 86 (in the middle of rising). To the bottom end. Thereafter, the carriage moves left and right, returns to the cap position after position detection, and the recording head is capped.

  In this maintenance and recovery mechanism, when the motor 96 rotates forward, the motor gear 97, the intermediate gear 98, the pump gear 99, and the intermediate gears 100 and 102 rotate, and the pump shaft 88a of the tube pump 88 rotates, so that the tube pump 88 is rotated. Operates to suck the inside of the recovery / moisturizing cap 86a. The other intermediate gears 103 and 104 and the cam gear 106 are not rotated (operated) because the rotation is blocked by the one-way clutch 101. Since the one-way clutch 101 is connected by the reverse rotation of the motor 96, the rotation of the motor 96 is transmitted to the cam gear 106 via the motor gear 97, the intermediate gear 98, the pump gear 99, and the intermediate gears 100, 102, 103, 104. The cam shaft 89 rotates. At this time, the tube pump 88 is structured not to rotate by the reverse rotation of the pump shaft 88a.

  Next, the maintenance / recovery operation in the image forming apparatus of the present invention will be described with reference to FIG. 6 showing the maintenance / recovery operation flow and FIG. 7 showing the operation time chart.

  When performing the recovery operation of the recording head, at time T0 in FIG. 7, the motor 96 in FIG. 5 is reversely rotated to rotate the cam shaft 89 to raise the cap 86a in FIG. 4 and FIG. In step S101, the nozzle surface of the recording head is capped, the motor 96 is rotated forward to operate the tube pump 88, and suction is performed from the nozzle of the recording head. Subsequent to this first step, at a time T2 in FIG. 7, the motor 96 is reversely rotated to further rotate the cam shaft 89, thereby separating the cap 86a from the nozzle surface of the recording head. Perform (step S102). Subsequent to the second step, a predetermined drive signal generated by a drive signal generation means (not shown) is used to move the meniscus to the outside of the nozzle without discharging ink droplets until time T3 in FIG. Is input to the recording head (step S103). At time T3, the wiper blade 84 shown in FIGS. 4 and 5 rises to the wiping position (position where it comes into contact with the nozzle surface). In this state, the carriage 21 shown in FIG. 3 is moved to move the nozzle surface of the recording head. After wiping and cleaning with the wiper blade 84, a third step of lowering the wiper blade 84 and separating from the nozzle surface is performed (step S104). Subsequent to the third step, a fourth step of operating the tube pump 88 to suck the ink in the cap 86a is performed at time T4 in FIG. 7 (step S105). The above process is repeated for all nozzles (step S106). As described above, since the meniscus is moved to the outside of the nozzle from the time of removing the cap from the nozzle surface in the second step to the time of wiping in the third step, different colors on the nozzle surface are caused by the negative pressure in the sub tank. Ink can be prevented from being sucked into the nozzle from the nozzle.

  Next, a predetermined drive signal input to the recording head during the above-described second step and third step will be described with reference to FIG. FIG. 8 is a diagram illustrating a change in voltage of a driving signal input to the recording head and a change in position of the meniscus. The falling time is set to be sufficiently longer than the natural vibration period of the pressure chamber so as not to eject the ink droplets, and a gentle pulsating pulse is used to raise the voltage at the end of the drive signal. If the drive frequency is 10 kHz, the drive signal set shown in FIG. 8A is input every 100 μs. FIG. 8B shows the meniscus position at this time. When the voltage falls slowly, it is slightly pulled inside the nozzle, but when the voltage rises, the meniscus position moves outside the nozzle. When the driving frequency is 10 kHz, the meniscus position is always located outside the nozzle after the driving signal input shown in FIG. 8A. Therefore, before wiping, different color inks on the nozzle surface are discharged by the negative pressure in the sub tank. It is possible to prevent the color mixture from being drawn inside.

  Here, the ink container that can be used in the present invention will be described. There are four types of ink accommodating portions, depending on the combination of the negative pressure generating portion and the negative pressure generating means, and any of them can be used. The negative pressure generation location is integrated with or separated from the ink tank, and the negative pressure generation means is whether the negative pressure generation means is an absorber or a bag attached with a spring or the like. Hereinafter, it demonstrates in order.

  First, as shown in FIG. 9, the A type ink storage unit is a type in which the negative pressure generating portion and the tank are separated, and the negative pressure generation is an absorber. The A type ink storage unit includes a negative pressure generation unit 110 that stores a capillary force generation member and a liquid supply unit 120 that stores ink 122. The liquid supply unit 120 is configured to be coupled to the negative pressure generation unit 110 through the gas-liquid exchange passages 130a and 130b. The negative pressure generation unit 110 includes a housing 112 having an ink supply port 111 that supplies ink (including liquid such as a processing liquid) to the outside of a recording head unit or the like that performs recording by ejecting liquid from an ejection port, and the housing 112. Is provided with a capillary force generating member 113 made of a blended fiber such as polypropylene and polyethylene. Further, the housing 112 is provided with an atmosphere communication port 114 for communicating the capillary force generating member 113 housed inside with the outside air, and a rib protruding from the inner surface of the housing 112 is formed in the vicinity of the air communication port 114. A buffer space 115 is provided. On the other hand, the liquid supply unit 120 stores the ink 122 directly in the housing 121, is connected to the negative pressure generation unit 110 via the gas-liquid exchange passages 130 a and 130 b, and supplies the ink 122 to the negative pressure generation unit 110. To do.

  Further, as shown in FIG. 10, the B type ink supply unit is a type in which a negative pressure generating portion and a tank are integrated, and negative pressure generation is a type using an absorber. That is, the B type ink supply unit has a configuration in which the A type negative pressure generating unit and the liquid supply unit are included in one casing. A negative pressure generation unit 110 that stores a capillary force generation member and a liquid supply unit 120 that stores ink 122, and the liquid supply unit 120 communicates with the negative pressure generation unit 110 via a gas-liquid exchange passage 131. It has become. The negative pressure generation unit 110 includes an ink supply port 111 that supplies ink (including liquid such as processing liquid) to the outside of a recording head unit that performs recording by discharging liquid from the discharge port. Is provided with a capillary force generating member 113 made of a blended fiber such as polypropylene and polyethylene. Further, the housing 112 is provided with an atmosphere communication port 114 for communicating the capillary force generating member 113 housed inside with the outside air, and a rib protruding from the inner surface of the housing 112 is formed in the vicinity of the air communication port 114. A buffer space 115 is provided. On the other hand, the liquid supply unit 120 directly stores the ink 122 and supplies the ink 122 to the negative pressure generation unit 110 via the gas-liquid exchange passage 131.

  Further, as shown in FIG. 11, the C type ink supply unit is a type in which a negative pressure generating portion and a tank are separated and a negative pressure is generated using a spring. The C-type ink supply unit includes a negative pressure generation unit 110 that stores a spring 116 and a liquid supply unit 120 that stores ink 122. The liquid supply unit 120 is coupled to the negative pressure generation unit 110 through the liquid supply path 132. The negative pressure generation unit 110 includes a housing 112 having an ink supply port 111 that supplies ink (including liquid such as a processing liquid) to the outside of a recording head unit or the like that performs recording by ejecting liquid from an ejection port, and the housing 112. A spring 116 that generates negative pressure and an inner bag 117 that stores ink 122 are provided. Further, the housing 112 is provided with an air communication port 114 for communicating the inside of the housing with the outside air. On the other hand, the liquid supply unit 120 stores the ink 122 directly in the housing 121 and supplies the ink 122 to the negative pressure generation unit 110 through the liquid supply path 132.

  Further, as shown in FIG. 12, the D type ink supply unit is a type in which the negative pressure generating portion and the tank are integrated, and the negative pressure is generated using a spring. The D-type ink supply unit 140 includes a housing 112, a spring 116 that generates negative pressure, and a liquid storage bag 118 that stores ink 122. The liquid storage bag 118 has flexibility and can be deformed as the ink stored therein is led out. When the ink is consumed, the liquid storage bag 118 is gradually crushed. At this time, the spring 116 prevents the crushing and the drag acts. Therefore, a negative pressure is generated in the liquid storage bag 118. The housing 112 is provided with an ink supply port 111 and an air communication port 114 for communicating the inside of the housing with the outside air. The liquid storage bag 118 has a triple structure in which a liquid contact layer having ink resistance, an elastic modulus dominating layer, and a gas barrier layer having excellent gas barrier properties are stacked in that order from the inside. In the present embodiment, polypropylene or polyethylene is used as the material of the innermost liquid contact layer constituting the liquid storage bag 118, cyclic olefin copolymer is used as the intermediate elastic modulus dominating layer, and EVOH ( EVA (saponified product of ethylene vinyl acetate copolymer resin) is used. Here, by including a functional adhesive resin material in the elastic modulus dominating layer, it is not necessary to specially provide an adhesive layer between the layers, so that the thickness of the liquid storage bag 118 can be reduced, which is preferable.

  In addition, this invention is not limited to the said embodiment, It cannot be overemphasized that various deformation | transformation and substitution are possible if it is description in a claim.

1 is a perspective view illustrating a configuration of an image forming apparatus of the present invention. It is a schematic sectional drawing which shows the structure of the mechanism part in the image forming apparatus of this invention. FIG. 3 is a plan view showing a main configuration of a mechanism unit in the image forming apparatus of the present invention. It is a top view which shows the structure of the capping means of a maintenance recovery mechanism. It is a front view which shows the structure of the drive mechanism of the capping means of a maintenance recovery mechanism. 3 is a flowchart showing a maintenance / recovery operation in the image forming apparatus of the present invention. 6 is a time chart showing a maintenance recovery operation in the image forming apparatus of the present invention. FIG. 6 is a diagram illustrating a change in voltage of a driving signal input to a recording head and a change in position of a meniscus. It is a schematic sectional drawing which shows the structure of an A type ink accommodating part. It is a schematic sectional drawing which shows the structure of a B type ink accommodating part. It is a schematic sectional drawing which shows the structure of a C type ink accommodating part. It is a schematic sectional drawing which shows the structure of a D type ink accommodating part.

Explanation of symbols

44; maintenance and recovery mechanism,
46a, 46b, 46c, 46d; cap member,
47, 84; wiper blade, 88; tube pump.

Claims (5)

A plurality of nozzle rows that discharge droplets of different colors, a pressure chamber that communicates with the nozzle rows, a droplet discharge head that has pressure generating means for changing the volume of the pressure chamber, and a drive signal that generates a drive signal An image forming apparatus comprising: a generating unit; and a plurality of sub tanks that supply recording liquid of each color to the droplet discharge head, wherein the recording liquid is supplied from a main tank to each sub tank. In the maintenance and recovery method to maintain and recover the performance of
A first step of covering the nozzle surface of the droplet discharge head with a cap, and operating the suction means connected to the cap to perform suction from the nozzle through the cap;
A second step of separating the cap from the nozzle surface;
A third step of supplying a predetermined drive signal generated by the drive signal generating means to the droplet discharge head to move the meniscus position in the nozzle to the outside of the nozzle without discharging the droplet;
A third step of cleaning the periphery of the nozzle by a cleaning means;
And a fourth step of activating the suction means to suck the ink in the cap. A plurality of nozzle rows that discharge droplets of different colors, a pressure chamber that communicates with the nozzle rows, a droplet discharge head that has pressure generating means for changing the volume of the pressure chamber, and a drive signal that generates a drive signal An image forming apparatus comprising: a generating unit; and a plurality of sub tanks that supply recording liquid of each color to the droplet discharge head, wherein the recording liquid is supplied from a main tank to each sub tank. In the maintenance and recovery mechanism that maintains and recovers the performance of
Suction means for performing suction from the nozzle side of the droplet discharge head to perform the recovery operation of the droplet discharge head;
After performing suction by the suction unit, a predetermined drive signal generated by the drive signal generation unit for moving the meniscus position in the nozzle to the outside of the nozzle without discharging the droplet is supplied to the droplet discharge head. A maintenance / recovery mechanism comprising: cleaning means for cleaning the recording liquid supplied and moved to the outside of the nozzle. A plurality of nozzle rows that discharge droplets of different colors, a pressure chamber that communicates with the nozzle rows, a droplet discharge head that has pressure generating means for changing the volume of the pressure chamber, and a drive signal that generates a drive signal In the image forming apparatus comprising a generating unit and a plurality of sub tanks that supply the recording liquid of each color to the droplet discharge head, and supplying the recording liquid from the main tank to each sub tank,
An image forming apparatus comprising the maintenance / recovery mechanism according to claim 2.   The image forming apparatus according to claim 3, further comprising a pressurizing unit that contracts the pressure chamber so that the position of the meniscus is moved to the outside of the nozzle without discharging the droplet.   4. The image forming apparatus according to claim 3, wherein the pressure generating means is a piezoelectric element.

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