JP5365092B2 - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve such a problem that a configuration to initially fill a head with ink while surely discharging air bubbles becomes complicated. <P>SOLUTION: Respective heads 101 are initially filled with the ink by supplying the ink by a branching member 54 branching and supplying the ink to the heads 101 from an ink tank 81, a plurality of supply paths 53 connecting the heads 101 with the branching member 54 and second opening/closing valves 55 opening/closing the supply paths 53, and cap members 62 sealing nozzle surfaces of the heads 101 and suction pumps 63 connected to the cap members 62. At such a time, a collective mode for performing an operation to fill the head with the ink by opening the second opening/closing valve 55 after decompressing space between the second opening/closing valve 55 and the head 101 by the suction pump 63 in such a state that the second opening/closing valve 55 is closed to all the heads 101, and an individual mode for performing such operation to the individual head 101 are controlled, and then opening/closing control is performed to the second opening/closing valve 55 several times when initially filling the head 101 with the ink, and the second opening/closing valve 55 is controlled to be always open during printing. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an image forming apparatus, and more particularly to an ink supply apparatus in an image forming apparatus including a recording head that ejects droplets.

  As an image forming apparatus such as a printer, a facsimile machine, a copying apparatus, a plotter, and a complex machine of these, for example, an ink jet recording apparatus is known as an image forming apparatus of a liquid discharge recording method using a recording head for discharging ink droplets. . This liquid discharge recording type image forming apparatus means that ink droplets are transported from a recording head (not limited to paper, including OHP, and can be attached to ink droplets and other liquids). Yes, it is also ejected onto a recording medium or a recording medium, recording paper, recording paper, etc.) to form an image (recording, printing, printing, and printing are also used synonymously). And a serial type image forming apparatus that forms an image by ejecting liquid droplets while the recording head moves in the main scanning direction, and a line type head that forms images by ejecting liquid droplets without moving the recording head There are line type image forming apparatuses using

  In the present application, the “image forming apparatus” of the liquid ejection method is an apparatus that forms an image by ejecting liquid onto a medium such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, or the like. In addition, “image formation” means not only that an image having a meaning such as a character or a figure is imparted to the medium but also an image having no meaning such as a pattern is imparted to the medium (simply liquid. It also means that a droplet hits the medium). “Ink” is not limited to ink, but is used as a general term for all liquids capable of image formation, such as recording liquid, fixing processing liquid, and liquid. DNA samples, resists, pattern materials and the like are also included.

  In such an image forming apparatus (hereinafter, also simply referred to as “inkjet recording apparatus”), when initial filling is performed for supplying ink from an ink tank to a recording head for the first time, bubbles in the recording head and the ink supply path are removed. It is necessary to discharge reliably. In particular, if bubbles remain in the recording head, normal droplet discharge cannot be performed from the discharge port (nozzle), and image defects such as white streaks appear in the image.

  Conventionally, it is known that after the inside of an ink flow path between an ink cartridge (ink tank) and a recording head is formed at a negative pressure, the pressure is released to atmospheric pressure to create an instantaneous ink flow to discharge bubbles. . As a method of repeating this negative pressure formation and release to the atmosphere, a valve (electromagnetic valve, etc.) is provided in the middle of the ink flow path to create a state where the negative pressure in the ink flow path by the suction pump is accumulated and the valve is opened. By controlling the valve and discharging bubbles by the instantaneous ink flow generated by opening the valve, or by intermittently performing the suction operation (drive) of the suction pump to create an instantaneous ink flow A method of discharging bubbles is known.

  For example, as described in Patent Document 1, a valve unit is arranged in the ink flow path between the ink cartridge and the head, and the opening and closing of the valve unit can be controlled in conjunction with the head cleaning operation. Valve opening control is performed with the negative pressure accumulated by the pump, and the suction pump is continuously driven so that bubbles are discharged by the instantaneous fast flow of ink generated by opening the valve unit. Are known.

  Further, as described in Patent Document 2, an open / close valve that shuts off the path is provided in the ink supply path, and a print mode for performing printing and a circulation mode for collecting ink supplied to the recording head to the sub tank are provided. There is also known a configuration that has two modes and discharges bubbles by circulating ink.

JP 2007-98959 A JP 2006-168023 A

  By the way, in a line type image forming apparatus including a line type head in which nozzle rows corresponding to the full width of the conveyed paper are arranged, the line type recording head has, for example, a nozzle row in which nozzles for discharging droplets are arranged. A recording head (also referred to as a multi-array head or a multi-head unit) in which a plurality of short heads are arranged along the nozzle arrangement direction is used.

  When a recording head having a configuration in which a plurality of heads are arranged in this way is used, ink can be stably supplied to each head during normal printing, while air bubbles are reliably discharged from each head during initial filling. It is requested to be able to do it. In this case, the prior art is applied to provide an opening / closing means in the ink supply path. Since the number of heads increases, the ink supply path for each head must be opened and closed with a simpler configuration.

  The present invention has been made in view of the above problems, and an object of the present invention is to simplify a configuration for performing initial filling of a multi-array head with respect to a recording head.

In order to solve the above problems, an image forming apparatus according to the present invention provides:
A recording head in which a plurality of heads for discharging droplets are arranged side by side;
An ink tank for storing ink to be supplied to the recording head;
A branch member that branches and supplies ink from the ink tank to each head of the recording head;
A plurality of supply paths connecting each head of the recording head and the branch member; and a plurality of opening / closing means for opening and closing the supply paths;
A plurality of cap members that respectively seal the nozzle surfaces of the heads, and a plurality of suction members that are individually provided for the plurality of cap members and connected to the corresponding cap members. Supply means;
When initially filling the recording head with ink,
With all the plurality of opening / closing means closed, and with the cap member sealing the nozzle surface of each head, all the plurality of suction means are driven, and the opening / closing means and the head A batch mode in which the opening and closing means are opened to fill the head with ink after decompressing the gap;
The KiHiraki closing means before that corresponds to the required head to fill the ink in the closed Ji state, the nozzle surface of a required head for filling the ink in the cap member corresponding to the required head filling the ink in sealed state, wherein the suction means is driven corresponding to the required head filling the ink, and the required head filling said opening and closing means and the ink corresponding to the required head filling the ink after reducing the pressure between the individual mode you fill the ink said have closing means opens corresponding to the required head of filling the ink into the required head,
Control means for controlling
The control means includes
In the state of sucking the head with the corresponding cap member and the corresponding suction means at the time of the initial filling, the corresponding opening / closing means is controlled to open and close multiple times,
During the printing, the opening / closing means is always controlled to be open.

According to the onset bright, as well as the structure for performing the initial filling for the printhead of Ma Lucia ray head is simplified, be performed simultaneously initial fill for a plurality of heads may also be performed individually initial charge You will also be able to.

Embodiments of the present invention will be described below with reference to the accompanying drawings. First, a first embodiment of the present invention will be described with reference to FIG. 1 and FIG. FIG. 1 is a schematic configuration diagram illustrating the overall configuration of the image forming apparatus according to the embodiment, and FIG. 2 is a plan explanatory diagram of the apparatus.
This image forming apparatus is a line type image forming apparatus, and includes an apparatus main body 1, a paper feed tray 2 on which paper P is stacked and fed, a paper discharge tray 3 on which printed paper P is discharged and stacked, and paper P A transport unit 4 that transports the paper from the paper feed tray 2 to the paper discharge tray 3, an image forming unit 5 that performs printing by ejecting liquid droplets onto the paper P transported by the transport unit 4, and a required timing after completion of printing. A cleaning device 6 that is a maintenance and recovery mechanism for maintaining and recovering each head of the image forming unit 5, a conveyance guide portion 7 that opens and closes the cleaning device 6, and an ink tank unit that supplies ink to each head of the image forming unit 5. 8 and a main tank unit 9 for supplying ink to the ink tank unit 8.

  The apparatus main body 1 includes front and rear side plates and stays (not shown), and the sheets P stacked on the sheet feed tray 2 are fed one by one to the transport unit 4 by the separation roller 21 and the sheet feed roller 22. Is done.

  The transport unit 4 includes a transport drive roller 41a, a transport driven roller 41b, and an endless transport belt 43 wound around these rollers 41a and 41b. A plurality of holes (not shown) are formed on the surface of the transport belt 43, and a suction fan 44 that sucks the paper P is disposed below the transport belt 43. Further, conveyance guide rollers 42a and 42b are respectively held on guides (not shown) on the conveyance driving roller 41a and conveyance driven roller 41b and are in contact with the belt 43 by their own weight.

  The conveyance belt 43 rotates around when the conveyance driving roller 41 a is rotated by a motor (not shown), and the paper P is sucked onto the conveyance belt 43 by the suction fan 44 and is conveyed by the rotation movement of the conveyance belt 43. The transport driven roller 41 b and the transport guide rollers 42 a and 42 b rotate following the transport belt 43.

  An image forming unit 5 including a recording head unit 50 including a plurality of recording heads 51 that discharge droplets to be printed on the paper P is disposed above the transport unit 4 so as to be movable in the arrow A direction. The image forming unit 5 is moved to above the cleaning device 6 during the maintenance / recovery operation (cleaning).

  The recording head unit 50 of the image forming unit 5 includes a plurality of recording heads 51y, 51m, 51c, 51k (hereinafter referred to as “yellow” (Y), magenta (M), cyan (C), and black (K)). When the colors are not distinguished from each other, the symbols without the sub-codes y, m, c, and k are used (the same applies to the other members).

  As shown in FIG. 3, each recording head 51 has 10 heads 101 </ b> A to 101 </ b> J arranged in a staggered manner in two rows on a head support member 100. As shown in FIG. 4, each head 101 has a nozzle surface 104 in which nozzle rows 103 in which a plurality of nozzles 102 for discharging droplets are arranged side by side are arranged in a zigzag manner. The configuration of the recording head unit 50 is not limited to these examples.

  In the image forming unit 5, a branching member 52, which is a branching unit that supplies ink of a required color to each recording head 51, is disposed above the recording head unit 50, and the supply between the branching member 52 and the recording head 51 is provided. Connected by a tube 53. An ink tank 81 of the ink tank unit 8 (only one ink tank is provided with a reference numeral for convenience of illustration) is disposed on the upstream side of the branching member 52, and the distributor 52 of the recording head 51 is connected via a supply tube 82. And a negative pressure is formed in each head 101 due to a water head difference between the ink tank 81 and each head 101 of the recording head 51. Further, the main tank unit 9 is disposed on the upstream side of the ink tank 81, and ink is supplied from the main tank 91 through the supply tube 92 to the ink tank 81.

  On the downstream side of the transport unit 4, a transport guide portion 7 that discharges the paper P to the paper discharge tray 3 is provided. The paper P guided and conveyed by the conveyance guide unit 7 is discharged to the paper discharge tray 3. The paper discharge tray 3 includes a pair of side fences 31 that regulate the width direction of the paper P and an end fence 32 that regulates the front end of the paper P.

  The maintenance / recovery mechanism (cleaning device) 6 includes four rows of cleaning means 61 corresponding to each recording head 51 of the image forming unit 5, and one cleaning means 61 includes ten heads 101 of the recording head 51. 10 caps 62 corresponding to 1 and a wiper member (not shown). Note that the cap 62 can be moved up and down independently. Further, below the cleaning unit 61, a suction pump 63 is disposed as a suction unit for sucking ink from the nozzles 102 of the head 101 in a state where the nozzle surface 104 of the head unit 100 is capped (sealed) with the cap 62. Has been. The cap 62 and the suction pump 63 constitute supply means in the present invention.

  In this image forming apparatus, after the printing is completed, when the recording head 51 that discharges the droplets is capped by the cleaning unit 61 and ink is sucked from the nozzles 102, or the nozzle surface 104 of the head of the recording head 51 is used. When the ink adhering to the toner is cleaned by the wiper member of the cleaning means 61, as shown in FIG. 5, after the printing is stopped, the entire transport unit 4 rotates in the direction of arrow B with the transport driven roller 41b as a fulcrum. By making the space between the image forming unit 5 larger than that at the time of image formation, a space for moving the image forming unit 5 is secured. At this time, the conveyance guide plate 71 of the conveyance guide portion 7 disposed on the upper portion of the cleaning device 6 is also rotated upward in the direction of the arrow C at the fulcrum 72, and the upper portion of the cleaning device 6 is opened.

  Then, after the transport unit 4 and the transport guide portion 7 are released (released), the image forming unit 5 moves in the paper passing direction (in the direction of arrow A), stops above the cleaning device 6, and the cleaning unit 61. Rises and shifts to a head cleaning operation (maintenance recovery operation) of each recording head 51.

Next, an ink supply system and an ink discharge system for the recording head in this embodiment will be described with reference to FIG.
An ink tank (sub tank) 81 that stores ink to be supplied to each head 101 of the recording head 51 is arranged with a required water head difference from each head 101 of the recording head 51. In this case, the negative in the nozzle surface 104 of the recording head 51 (opening of the nozzle 102 to the nozzle surface 104) generated by the difference (water head difference) between the liquid level of the ink tank 81 and the height of each head 101 of the recording head 51. The pressure (water head pressure) varies with the consumption of the ink 200 in the sub tank 81. The ink tank 81 is provided with an air release path 83, and an air filter 86 is interposed in the air release path 83.

  In addition, a main tank 91 for supplying ink to the ink tank 81 is provided, and the liquid level is detected by a liquid level sensor 87 such as an electrode pin provided in the ink tank 81, and the main tank 91 receives the signal from the sensor 87 according to a signal from the sensor 87. By controlling the supply of ink to the ink tank 81, the amount of ink in the ink tank 81 is controlled within a certain range. An ink supply path (hereinafter referred to as a “second supply path 93”) formed by a supply tube 93 from the main tank 91 to the ink tank 81 has an opening / closing valve 93 (hereinafter referred to as an electromagnetic valve). The second on-off valve 93 is controlled to open and close based on a signal from the liquid level sensor 87 to control ink supply.

  On the other hand, a branching member 52 is disposed as a branching unit that branches the ink supply path (flow path) with respect to each head 101 of one recording head 51. In addition, as shown in FIG. 1, the branch member 52y, 52m, 52c, and 52k are arrange | positioned with respect to each recording head 51y, 51m, 51c, and 51k, respectively. A supply tube 82 is connected to one end of the branch member 52 between the ink tank 81 and ink is supplied from the ink tank 81 via the supply tube 82.

  Then, ink is supplied from the branch member 52 to each head 101 of the recording head 51 through an ink supply path (hereinafter referred to as “first supply path 53”) formed by the supply tube 53. The first supply path 53 is provided with an opening / closing valve 55 (hereinafter referred to as “first opening / closing valve 55”) as an opening / closing means.

  Further, in order to suck ink from the nozzles 102 of the head 101 of the recording head 51, the cleaning device 6 is formed by a cap member 62 that seals the nozzle surface 104 of the head 101, and an exhaust ink tube 64 on the cap member 62. A suction pump 63 as suction means connected via an ink discharge path (hereinafter referred to as “ink discharge path 64”), and suction with the nozzle surface 104 of the head 101 sealed with a cap 62. By driving the pump 63, the sealed space in the cap 62 becomes negative pressure, and ink is sucked and discharged from the nozzle 102, and ink is supplied from the ink tank 81 to the head 101.

Next, an outline of the control unit of the image forming apparatus will be described with reference to a block diagram of FIG.
The control unit includes a main control unit (system controller) 501 including a microcomputer that also serves as a control unit according to the present invention that controls the entire image forming apparatus, an image memory, a communication interface, and the like. The main control unit 501 sends print data to the print control unit 502 in order to form an image on a sheet based on image data transferred from an external information processing apparatus (host side) and various command information.

  Based on the print data signal received from the main control unit 501, the print control unit 502 generates data for driving the pressure generating means for ejecting the droplets from the recording head 51, and transfers the data. Various signals necessary for confirmation of transfer and the like are transferred to the head driver 503, and a storage unit as drive waveform data storage means, a D / A converter, a voltage amplifier and a current amplifier for D / A conversion of drive waveform data Drive waveform generation unit configured by the above and selection means for selecting a drive waveform to be given to the head driver 503, and generates a drive waveform configured by one drive pulse (drive signal) or a plurality of drive pulses (drive signal) Then, the output is output to the head driver 503 to drive and control the recording head 51.

  Further, the main control unit 501 drives and controls the sheet feed motor 505 that rotates the transport belt 43 and the suction pump 63 via the motor driver 504, and controls the first on-off valve 55 and the second on-off valve 93 switching means 114. The on / off driving of the on / off valves 112 and 113 is controlled.

  The main control unit 501 receives a detection signal from the sensor group 506 including the ink level sensor 87 described above, and inputs / outputs various information and exchanges display information with the operation unit 507. .

Next, the ink initial filling control in the batch mode by the control unit will be described with reference to the flowchart shown in FIG. 8 and the timing chart shown in FIG.
First, when the recording head 51 is initially filled with ink, the nozzle surface 104 of each head 101 of the recording head 51 is capped (sealed) by the cap 62 of the cleaning device 6.

  With reference to FIG. 8, it is determined whether or not the ink tank 81 is empty. If the ink tank 81 is empty, the second on-off valve 93 is opened and the main tank is filled until the ink tank 81 is full. Ink is supplied from 91 to the ink tank 81, and when the ink tank 81 becomes full, the second on-off valve 93 is closed to shut off the ink supply.

  Next, a time (closing time tc in FIG. 9) for closing (shutting down) the first on-off valve 55 is set. Then, after all the suction pumps 63 are driven (on), all the first on-off valves 55 are closed (off), and it is determined whether or not the closing time set for the first on-off valves 55 has elapsed. Until the closing time elapses, the state in which all the suction pumps 63 are driven with all the first on-off valves 55 closed is continued.

  And when the closing time which the 1st on-off valve 55 set passed, the time (opening time to of FIG. 9) which makes the 1st on-off valve 55 an open state is set. Then, all the first on-off valves 55 are opened (on), and it is determined whether or not the opening time set for the first on-off valves 55 has elapsed. Until the opening time elapses, the state in which all the suction pumps 63 are driven while all the first on-off valves 55 are open is continued.

  When the opening time set by the first on-off valve 55 has elapsed, the number of times of opening / closing the first on-off valve 55 (set number Nn in FIG. 9) is set. Then, the opening / closing (blocking / opening) of all the first opening / closing valves 55 is repeated until the number of opening / closing of the first opening / closing valves 55 reaches the set opening / closing frequency.

  In this way, after opening and closing the first on-off valve 55 is repeated a set number of times, all the suction pumps 63 are stopped (off), and the initial ink filling is completed.

  That is, as shown in FIG. 9, the opening / closing of the first on-off valve 55 is repeated while the suction pump 63 is operating. At this time, in a state where the first on-off valve 55 is closed, the inside of the first supply passage 53 between the first on-off valve 55 and the head 101 is depressurized, and then the first on-off valve 55 is opened. Ink is supplied to the head 101. By repeating the opening / closing operation of the first opening / closing valve 55, a rapid ink flow is intermittently generated, and the initial ink filling can be performed for all the heads 101 while the bubbles in the head 101 are surely discharged. .

  Here, the timing (closing time and opening time) for opening / closing the first opening / closing valve 55 and the number of opening / closing (number of intermittent supply) are set, and the ink supply is intermittently repeated by controlling the opening / closing of the first opening / closing valve 55 multiple times. As a result, the bubbles in the head can be discharged more reliably.

  Next, ink initial filling control in the individual mode will be described. The initial ink filling in the individual mode is only different from the collective mode in that the suction pump 63 to be driven and the first opening / closing valve 55 that performs the opening / closing control a plurality of times are performed on the required head 101.

  In other words, if there is some variation in the ink supply and bubble discharge characteristics among the plurality of heads 101 of the recording head 51, the wasteful ink consumption increases if the initial filling is repeated for all the heads 101. Therefore, in this case, wasteful ink consumption can be reduced by driving the suction pump 63 and controlling the first opening / closing valve 55 a plurality of times only for the required head 101.

Next, ink supply control to the ink tank in the print mode will be described with reference to the flowchart shown in FIG.
In the printing mode, the first on-off valve 55 is always open. After performing the printing operation, the ink level sensor 87 of the ink tank 81 determines whether or not the ink level has dropped below a predetermined height corresponding to the empty state (empty). When the tank 81 becomes empty, the second on-off valve 93 is opened to supply ink from the main tank 91 to the ink tank 81, and the ink level sensor 87 of the ink tank 81 corresponds to the ink level full. The second on-off valve 93 is closed to cut off the ink supply when the height rises to the height of (or becomes full). The ink level sensor 87 is composed of a plurality of electrode pins having different heights, and the ink level is below a predetermined height (empty) and above a predetermined height. It is possible to detect that it has become full.

  In this case, the ink tank 81 is always in communication with the atmosphere via the air filter 87, maintains atmospheric pressure, and the liquid level in the ink tank 81 and the print head 51 cause a meniscus of the nozzles of the print head 51 due to the water head difference. Is held and printing is always possible.

  In this way, a branch member that branches and supplies ink from the ink tank to each head of the recording head, a plurality of supply paths that connect each head of the recording head and the branch member, and an opening / closing means that opens and closes the supply path A plurality of supply means composed of a cap member for sealing the nozzle surface of each head and a suction means connected to the cap member, and a plurality of opening / closing means when the ink is initially filled in the recording head In a closed state, the pressure between the opening and closing means and the head is reduced by each supply means, then the opening and closing means are opened and the ink is filled in the head, and the plurality of opening and closing means are individually closed. After reducing the pressure between the opening / closing means closed by the supply means corresponding to the closed opening / closing means and the corresponding head, the closed opening / closing means is opened to open And a control means for controlling the individual mode for filling the head into the head, and the control means controls the opening and closing means a plurality of times during initial filling and controls the opening and closing means to be always open during printing. As a result, the configuration for performing the initial filling of the recording head of the multi-array head is simplified, and the initial filling can be performed simultaneously for a plurality of heads or individually. Become.

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 11 is a schematic explanatory view showing an ink supply system and an ink discharge system for the recording head in the embodiment.
In this embodiment, a pressure sensor 56 is provided between the first on-off valve 55 and the head 101 as pressure detecting means for detecting the pressure in the second supply path 53. Others are the same as in the first embodiment.

Next, the initial ink filling control by the control unit will be described with reference to the flowchart shown in FIG.
Here, instead of setting the closing time and opening time of the first on-off valve 55 in the first embodiment, the first time when the detected pressure of the pressure sensor 56 reaches a predetermined set pressure Pv (for example, −90 kpa). By performing control to open the on-off valve 55, the first on-off valve 56 is controlled to open and close a set number of times.

  By doing so, the supply path from the first on-off valve to the head can be more reliably reduced to a predetermined pressure to perform initial filling, and the reliability of bubble discharge performance is improved.

  In the above-described embodiment, an example in which the present invention is applied to a line type image forming apparatus has been described. However, the present invention can be similarly applied to a serial type image forming apparatus.

1 is a schematic front view illustrating an overall configuration of an example of an image forming apparatus according to a first embodiment of the present invention. Similarly it is principal part plane explanatory drawing. FIG. 2 is an explanatory plan view of a recording head. It is a plane explanatory view of a head. It is principal part explanatory drawing used for description at the time of cleaning operation | movement. FIG. 3 is a schematic explanatory diagram of an ink supply system and a discharge system. It is a functional block diagram explaining the outline | summary of a control part. It is a flowchart with which it uses for description of the ink initial filling control in the embodiment. It is also a timing chart. FIG. 6 is a flowchart for explaining the print mode. It is a typical explanatory view of the ink supply system and discharge system in a 2nd embodiment of the present invention. It is a flowchart with which it uses for description of the ink initial filling control in the embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Apparatus main body 4 ... Conveyance unit (conveyance part)
5. Image forming unit 6. Cleaning device (maintenance and recovery mechanism)
DESCRIPTION OF SYMBOLS 7 ... Conveyance guide part 8 ... Ink tank unit 9 ... Main tank unit 50 ... Recording head unit 51 ... Recording head 53 ... Supply tube (supply path)
54 ... Branching member 55 ... Second on-off valve (open / close means)
62 ... Cap 63 ... Suction pump 81 ... Ink tank 91 ... Main tank 101 ... Head

Claims (2)

A recording head in which a plurality of heads for discharging droplets are arranged side by side;
An ink tank for storing ink to be supplied to the recording head;
A branch member that branches and supplies ink from the ink tank to each head of the recording head;
A plurality of supply paths connecting each head of the recording head and the branch member; and a plurality of opening / closing means for opening and closing the supply paths;
A plurality of cap members that respectively seal the nozzle surfaces of the heads, and a plurality of suction members that are individually provided for the plurality of cap members and connected to the corresponding cap members. Supply means;
When initially filling the recording head with ink,
With all the plurality of opening / closing means closed, and with the cap member sealing the nozzle surface of each head, all the plurality of suction means are driven, and the opening / closing means and the head A batch mode in which the opening and closing means are opened to fill the head with ink after decompressing the gap;
The KiHiraki closing means before that corresponds to the required head to fill the ink in the closed Ji state, the nozzle surface of a required head for filling the ink in the cap member corresponding to the required head filling the ink in sealed state, wherein the suction means is driven corresponding to the required head filling the ink, and the required head filling said opening and closing means and the ink corresponding to the required head filling the ink after reducing the pressure between the individual mode you fill the ink said have closing means opens corresponding to the required head of filling the ink into the required head,
Control means for controlling
The control means includes
In the state of sucking the head with the corresponding cap member and the corresponding suction means at the time of the initial filling, the corresponding opening / closing means is controlled to open and close multiple times
An image forming apparatus, wherein the open / close means is always controlled to be open during printing.   Pressure detecting means for detecting the pressure of the supply path between the opening and closing means and the head, and the control means controls the opening and closing means based on the detection result of the pressure detecting means when performing the initial filling. 2. The image forming apparatus according to claim 1, wherein the image forming apparatus is opened.

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