JP2007130979A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming device capable of accurately controlling a replenishment amount to a head tank. <P>SOLUTION: A negative pressure detection lever 106, which is displaced according to negative pressure, is provided displaceably in the head tank 35. When an ink filling (replenishment supply) operation is executed to the head tank 35, ink supply is executed until an opening amount of the negative pressure detection lever 106 becomes a decided opening amount after deciding the opening amount of the negative pressure detection lever 106 on the basis of opening amount data of the negative pressure detection lever 106 in the head tank 35. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus including a head tank.

  In general, as an image forming apparatus that combines a printer / fax / copier or a combination of these functions, an image forming unit that employs an electrophotographic method is known. For example, liquid discharge that discharges liquid droplets of recording liquid is known. Recording is performed while a recording medium (hereinafter also referred to as “paper” is not limited to a material, and the recording medium, a transfer material, and the like are also used synonymously) using a recording head constituted by a head. Some are equipped with an image forming unit of an ink jet system that performs image formation (recording, printing, printing, and printing are also used synonymously) by attaching liquid droplets (hereinafter also referred to as ink droplets) to paper. is there.

  In such an ink jet recording type image forming apparatus, a head tank (also referred to as a sub-tank), which is a small-capacity recording liquid container for supplying a recording liquid to a recording head, is mounted on a carriage. 2. Description of the Related Art There is known an apparatus in which a cartridge (main tank) is installed on the apparatus main body side, and recording liquid (ink) is replenished and supplied to the head tank from the main cartridge on the apparatus main body side.

As such a head tank, as described in Patent Document 1, an opening of a case for forming a recording liquid storage portion is covered with a film-like member, and the film-like member is moved outwardly from the inside. An elastic member that presses and urges toward the recording liquid is provided so that a negative pressure is generated by the urging force of the elastic member by reducing the recording liquid in the recording liquid storage unit, and the amount of the stored material stored in the recording liquid storage unit There has been known one provided with a negative pressure lever which is a displacement member which is displaced according to the above.
JP 2003-231275 A JP-A-2005-169664 JP 2005-059274 A

As other head tanks or sub tanks and recording apparatuses including these, for example, those described in Patent Documents 4 to 7 are known.
That is, in Patent Document 4, a pressure sensor is mounted between an ink cartridge and a recording head, and a pressure sensor is installed at a location away from the tank, and a negative pressure state inside the recording head is sensed. A configuration for maintaining a desired negative pressure by moving up and down is described.
Japanese Patent Laid-Open No. 2003-341028

Patent Document 5 discloses a first ink tank that is open to the atmosphere through an air opening and stores printing ink, and a second ink that stores ink while maintaining a deaerated state. A tank, a switching valve for selectively connecting the first and second ink tanks to the recording head, and a control means for controlling the switching valve, and applying a negative pressure to the recording head by the capping means when the recording head is cleaned. It is described that the ink in the first ink tank or the second ink tank is discharged from the recording head.
Japanese Patent No. 3402351

Patent Document 6 discloses a first chamber including an ink supply port for containing a negative pressure generating member and supplying liquid to the outside and an air communication port for communicating with the outside, and the first chamber, An ink injection method for replenishing ink using a replenishing container with respect to an ink tank having a second chamber that forms a sealed space excluding the communicating portion through the communicating portion, wherein the gas in the second chamber is A first hollow needle communicated with an existing portion, and a portion below the first needle in the second chamber provided at the tip of the path for moving the ink in the replenishing container to the second chamber The second hollow needle communicated with the second chamber and a conduction step of connecting the second chamber and the replenishing container with the second chamber, and after the conduction step, the gas in the second chamber is opened to the atmosphere Ink filling work for moving the ink in the replenishing container from the second hollow needle to the second chamber via the path Then, after the ink injection step, the first hollow needle is removed from the second chamber, the portion where the gas in the second chamber is present is hermetically sealed, and the second hollow needle and the second passage are connected to the second chamber. And a gas introduction step for discharging the ink from the chamber to the refill container and introducing the air introduced through the atmosphere communication port of the first chamber into the second chamber through the communication portion. Yes.
Japanese Patent No. 3437491

Patent Document 7 discloses a main ink tank including a first ink chamber that holds ink supplied to a recording head in a state having a free surface, a sub ink tank including a sub ink chamber that holds ink, and a first ink tank. And connecting means having at least one communication path for communicating between the ink chamber and the sub ink chamber, and supplying ink from the sub ink tank to the main ink tank.
JP 2001-187459 A

  In the head tank including a displacement member that is displaced according to the amount of the contents described in Patent Document 1 and the like described above, when the recording liquid in the head tank decreases and the recording liquid is replenished and supplied from the main tank, Although the replenishment amount is controlled based on the displacement amount of the displacement member, the displacement amount of the displacement member varies depending on the head tank.

  For this reason, the replenishment amount of the recording liquid to the head tank may deviate from the target amount, resulting in overfilling or insufficient filling. As a result, the negative pressure control in the head tank is not aimed, and there is a possibility that image quality deterioration, recording liquid leakage from the head tank, and the like may occur.

  SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus in which a replenishment amount for a head tank can be accurately controlled.

  In order to solve the above-described problem, an image forming apparatus according to the present invention is based on a displacement amount of a displacement member with respect to a predetermined content suction amount and a displacement amount of the displacement member accompanying replenishment of the recording solution. It was set as the structure provided with the means to control replenishment.

  Here, the displacement amount with respect to the predetermined content suction amount of the displacement member is the displacement amount when the predetermined amount of recording liquid is sucked, and the displacement amount with respect to the predetermined content suction amount of the displacement member is a predetermined amount of air. It can be set as the structure which is the displacement amount when attracting | sucking.

  Further, the displacement amount of the displacement member with respect to the predetermined content suction amount may be a displacement amount with respect to the recording liquid suction amount when the operation of forming the negative pressure of the head tank is performed. In this case, it is preferable to update the displacement amount of the displacement member with respect to the predetermined content suction amount every time the operation of forming the negative pressure of the head tank is performed.

  Further, the displacement amount of the displacement member with respect to the predetermined content suction amount may be a fixed value determined in advance for the head tank.

  In addition, when performing the operation of forming the negative pressure of the head tank, when the displacement amount of the displacement member is abnormal, the structure of repeatedly performing the negative pressure until the displacement amount becomes normal, forming the negative pressure of the head tank When the displacement of the displacement member is abnormal, when the displacement of the displacement member is abnormal, the recording liquid is repeatedly sucked until the displacement can be regarded as normal. When the operation of forming the negative pressure of the head tank is performed, the displacement of the displacement member When the air pressure is abnormal, the air suction can be repeated until the displacement amount can be regarded as normal.

  Further, the displacement amount of the displacement member when performing the operation of forming the negative pressure of the head tank is accumulated, and the negative displacement is referred to by referring to the past displacement amount accumulated when performing the operation of forming the negative pressure of the head tank. It can be set as the structure which discriminate | determines normal / abnormal of the pressure formation result.

  According to the image forming apparatus of the present invention, there is provided means for controlling the replenishment of the recording liquid to the head tank based on the displacement amount of the displacement member with respect to the predetermined content suction amount and the displacement amount of the displacement member accompanying the replenishment of the recording liquid. Therefore, the replenishment control according to the displacement amount of the displacement member of the head tank can be performed, and the influence due to the variation of the displacement amount of the displacement member can be reduced and replenishment can be performed with an accurate replenishment amount.

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

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

  Further, the operation / display unit 5 has the remaining amounts of the ink cartridges 10k, 10c, 10m, and 10y of each color at the arrangement positions corresponding to the mounting positions (arrangement positions) of the ink cartridges 10k, 10c, 10m, and 10y of the respective colors. The remaining amount display portions 11k, 11c, 11m, and 11y for each color for displaying the near end and the end are arranged. Further, the operation / display unit 5 is also provided with a power button 12, a paper feed / print resume button 13, and a cancel button 14.

Next, the mechanism part of the ink jet recording apparatus will be described with reference to FIGS. FIG. 3 is a schematic side view illustrating the outline of the mechanism, and FIG.
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, and a timing belt is held by a main scanning motor (not shown). 3 is moved and scanned in the direction indicated by the arrow (carriage main scanning direction) in FIG.

  As described above, the carriage 33 includes a recording head 34 including four droplet discharge heads that discharge ink droplets of yellow (Y), cyan (C), magenta (M), and black (Bk). A plurality of ink ejection openings are arranged in a direction crossing the main scanning direction, and are mounted with the ink droplet ejection direction facing downward.

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

  A driver IC is mounted on the recording head 34 and is connected to a control unit (not shown) via a harness (flexible print cable) 22.

  Further, the carriage 33 is equipped with a head tank 35 of each color for supplying ink of each color to the recording head 34. As described above, each color head tank 35 is replenished and supplied with ink of each color from the ink cartridge 10 of each color mounted in the cartridge loading unit 4 via the ink supply tube 36 of each color. The cartridge loading 4 is provided with a supply pump unit 24 for feeding ink in the ink cartridge 10, and the ink supply tube 36 is engaged with the rear plate 21 </ b> C constituting the frame 21 in the middle of turning. It is held by a stop member 25.

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

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

  The transport belt 51 is an endless belt, and is configured to wrap around the transport roller 52 and the tension roller 53 and circulate in the belt transport direction (sub-scanning direction). Further, a charging roller 56 that is a charging unit for charging the surface of the transport belt 51 is provided. The charging roller 56 is disposed so as to come into contact with the surface layer of the transport belt 51 and to rotate following the rotation of the transport belt 51. Further, a guide member 57 is disposed on the back side of the conveyor belt 51 in correspondence with a printing area by the recording head 34.

  The transport belt 51 rotates in the belt transport direction of FIG. 3 when the transport roller 52 is rotationally driven through timing by a sub-scanning motor (not shown).

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

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

  Further, as shown in FIG. 3, a maintenance / recovery mechanism 81 including a recovery means for maintaining and recovering the state of the nozzles of the recording head 34 is arranged in the non-printing area on one side of the carriage 33 in the scanning direction. Yes.

  The maintenance / recovery mechanism 81 includes cap members (hereinafter referred to as “caps”) 82a to 82d (hereinafter referred to as “caps 82” when not distinguished from each other) for capping the nozzle surfaces of the recording head 34, and nozzle surfaces. A wiper blade 83 that is a blade member for wiping the ink, and an empty discharge receiver 84 that receives liquid droplets when performing empty discharge for discharging liquid droplets that do not contribute to recording in order to discharge the thickened recording liquid. ing. Here, the cap 82a is a suction and moisture retention cap, and the other caps 82b to 82d are moisture retention caps.

  Then, the waste liquid of the recording liquid generated by the maintenance / recovery operation by the maintenance / recovery mechanism 81, the ink discharged to the cap 82, the ink attached to the wiper blade 83 and removed by the wiper cleaner 85, and the idle ejection to the idle ejection receiver 94. The discharged ink is discharged and stored in a waste liquid tank (not shown).

  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 88 for receiving the droplets at the time is disposed, and the empty discharge receiver 88 is provided with an opening 89 along the nozzle row direction of the recording head 34.

  In the ink jet recording apparatus configured as described above, the sheets 42 are separated and fed one by one from the sheet feeding tray 2, and the sheet 42 fed substantially vertically upward is guided by the guide 45, and the transport belt 51 and the counter roller 46, and the leading end is guided by the conveying guide 37 and pressed against the conveying belt 51 by the tip pressing roller 49, and the conveying direction is changed by approximately 90 °.

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

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

  Further, during printing (recording) standby, the carriage 33 is moved to the maintenance / recovery mechanism 81 side, and the recording head 34 is capped by the cap 82 to keep the nozzles in a wet state, thereby preventing ejection failure due to ink drying. . Further, the recording liquid is sucked from the nozzle by a suction pump (not shown) with the recording head 34 capped by the cap 82 (referred to as “nozzle suction” or “head suction”), and the thickened recording liquid and bubbles are discharged. Perform recovery action. 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.

  Next, an example of the head tank 35 in this image forming apparatus will be described with reference to FIGS. 4 is an external perspective view of the head tank, FIG. 5 is an exploded perspective view of the head tank, FIG. 6 is a schematic side view of the head tank, and FIG. 7 is taken along line AA in FIG. It is a schematic sectional explanatory drawing which follows.

  The head tank 35 is flexible enough to seal the opening (one surface of the head tank 15) of the ink storage unit 100 to the container main body (case main body) 101 that forms the ink storage unit 100 that stores ink as recording liquid. A film-like member (flexible film-like member) 102 is attached by adhesion or welding, and the film-like member 102 is disposed outwardly between the case main body 101 and the film-like member 102 inside the ink containing portion 100. A spring 103, which is an elastic member for biasing, is provided.

  Here, the film-like member 102 may have a single-layer configuration, but may have a two-layer configuration in which different types of first and second layers are laminated, for example, a configuration in which polyethylene and nylon film-like members are laminated, It can be set as the structure which formed the silica vapor deposition layer in the layer. By configuring the film-like member 102 to have two or more different types of layers, it is possible to improve the liquid resistance against the ink to be stored. In this case, by adopting a laminated structure of polyethylene and nylon, it is possible to reliably ensure liquid resistance against ink. Moreover, the liquid resistance with respect to the ink accommodated can also be improved by including a silica vapor deposition layer in the film-like member 102.

  Furthermore, a bulging portion 102a having a convex shape corresponding to the spring 103 is formed on the film-like member 102, and a reinforcing member 104 is attached to the outer surface thereof. In this manner, by providing the flexible film-like member 102 with the convex portion, the elastic member (here, the spring) 103 can be stably held. In this case, the flexible film-like member 102 can be easily formed with a convex portion by forming a sheet-like film member into a convex shape.

  A negative pressure detection lever 106 that is a displacement member that is displaced according to the displacement of the film-like member 102 is swingably attached to support portions 107 and 107 provided on the side of the case 101. The negative pressure detection lever 106 is pressed against the film-like member 102 side by a spring 108.

  In addition, the case 101 is provided with an ink introduction path 111 for replenishing ink in the ink containing part 100, and a connecting means for connecting the ink introduction path 111 and the supply tube 36 connected to the ink cartridge 10. 112 can be detachably mounted.

  Further, a connecting member 113 for supplying ink from the ink storage unit 100 to the recording head 34 is attached to the lower part of the case 101, and an ink supply path 114 of the recording head 34 is formed in the connecting member 113, so A filter 115 is interposed between the two.

  An air flow path 121 is formed in the upper part of the case 101 for taking out air from the ink containing portion 100. The air flow path 121 includes an inlet flow path portion 122 whose opening faces the ink containing portion 100 and a flow path portion 123 following the inlet flow path portion 122, and an air opening hole 131 provided in the case 101 on the downstream side. In addition, an accumulation portion 126 is continuously formed in a portion that is lower than the atmosphere opening hole 131 in the use state.

  The atmosphere release hole 131 is provided with an atmosphere release valve mechanism 132 which is an atmosphere release means for switching between the sealed state and the atmosphere release state in the head tank 35. The atmosphere release valve mechanism 132 is configured by accommodating a valve seat 134, a ball 135 as a valve body, and a spring 136 for urging the ball 135 toward the valve seat 134 in a holder 133.

  In addition, two detections for detecting that the amount of gas (air) in the head tank 35 has become a predetermined amount or more (or that the remaining amount of ink has become a predetermined amount or less) are provided above the case 101. Electrodes 141 and 142 are attached. The amount of gas (or the amount of ink) is changed by changing the conduction state between the detection electrodes 141 and 142 in a state where both the detection electrodes 141 and 142 are immersed in ink and in a state where at least one of the detection electrodes 141 and 142 is not immersed in ink. ) Can be detected.

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 300 includes a main control unit 301 configured by a microcomputer that also serves as a negative pressure maintenance control unit that controls the entire image forming apparatus, and a print control unit 302 configured by a microcomputer that controls print control. Yes.

  The main control unit 301 then forms a main scanning motor in order to form an image on the paper 42 based on information such as print data input from the communication circuit 101 from a host 400 such as a personal computer equipped with the printer driver 401. Drive 201 and sub-scanning motor 205 are controlled via main scanning motor drive circuit 303 and sub-scanning motor 304, and control such as sending print data to print control unit 302 is performed.

  The main control unit 301 receives a detection signal from a carriage position detection circuit 305 that detects the position of the carriage 33, and the main control unit 301 controls the movement position and movement speed of the carriage 33 based on the detection signal. To do. The carriage position detection circuit 305 detects the position of the carriage 33 by, for example, reading and counting the number of slits of an encoder sheet arranged in the scanning direction of the carriage 33 with a photosensor mounted on the carriage 33. The main scanning motor drive circuit 303 rotates the main scanning motor 201 according to the carriage movement amount input from the main control unit 301 to move the carriage 33 to a predetermined position at a predetermined speed.

  Further, the main control unit 301 receives a detection signal from a conveyance amount detection circuit 306 that detects the movement amount of the conveyance belt 51, and the main control unit 301 moves the movement amount and movement speed of the conveyance belt 51 based on the detection signal. To control. The conveyance amount detection circuit 306 detects the conveyance amount by, for example, reading and counting the number of slits of the rotary encoder sheet attached to the rotation shaft of the conveyance roller 52 with a photo sensor. The sub-scanning motor driving circuit 304 rotates the sub-scanning motor 205 in accordance with the conveyance amount input from the main control unit 301 and rotationally drives the conveyance roller 52 to move the conveyance belt 51 to a predetermined position at a predetermined speed. Move with.

  The main control unit 301 rotates the sheet feeding roller 43 once by giving a sheet feeding roller driving command to the sheet feeding roller driving circuit 307. The main control unit 301 drives the motor 191 through the maintenance / recovery mechanism driving motor drive circuit 308 to move the cap 82 up and down and the wiper blade 83 up and down.

  The main control unit 301 drives and controls the ink supply motor for driving the pump of the supply unit 24 via the ink supply motor drive circuit 311, and the ink cartridge 10 loaded in the cartridge loading unit 4 controls the head tank 35. Supply ink.

  When the main controller 301 supplies ink to the head tank 35 with the carriage 33 at the position of the maintenance / recovery mechanism 81, the negative pressure detection lever 106 of the head tank 35 has been displaced to a predetermined position. A detection signal from the full tank detection sensor 312 for detecting the detection, a detection signal from the cartridge cover sensor 312 for detecting opening and closing of the front cover 6 of the cartridge loading unit 4 and the like are input.

  In addition, the main control unit 301 stores, through the cartridge communication circuit 314, non-volatile memories 115k, 115c, 115m, and 115y that are storage units provided in the respective ink cartridges 10 attached to the cartridge loading unit 4 (“nonvolatile” if not distinguished) The information stored in the volatile memory 115 ") is taken in, required processing is performed, and the information is stored and held in a non-volatile memory (for example, EEPROM) 315 as a main body storage means.

  Here, the remaining amount of the ink cartridge 10 is detected by reading out the remaining amount information stored in the non-volatile memory 115 of the ink cartridge 10 and temporarily storing it in the non-volatile memory 315 on the main body side. The number of ejected droplets from the ink is counted, the amount of ink used is calculated based on this count value, and a new ink remaining amount obtained based on the ink remaining amount and the ink amount used is transferred from the ink cartridge 10 to the head for each printing. Each time ink is supplied to the tank 35, the data is written in the nonvolatile memory 115 of the ink cartridge 10. Then, the remaining amount of ink stored in the nonvolatile memory 115 of the ink cartridge 10 is read to detect the absence of ink (ink end or ink near end).

  The print control unit 302 ejects droplets of the recording head 34 (recording head 134) based on the signal from the main control unit 301 and the carriage position and conveyance amount from the carriage position detection circuit 305 and the conveyance amount detection circuit 306. Data for driving the pressure generating means is generated and applied to the head drive circuit 310.

  The head drive circuit 310 drives the pressure generating means (piezoelectric element in the case of a piezo head) of the recording head 34 based on the print data from the print control unit 302, and discharges droplets from a required nozzle.

  Further, the main control unit 301 stores and holds the usage amount of the color material (ink) and the number of printed sheets in the non-volatile memory (for example, EEPROM) 315 as statistical information (statistical data), and based on the remaining amount of ink and the number of printed sheets. When a request for the number of printable sheets is made through the printer driver 401 of the host 400, a process for responding to the host 400 side with information on the number of printable sheets relating to the number of sheets that can be printed with the current ink remaining amount and information on the remaining amount of ink is performed. In response to the response from the image forming apparatus, the printer driver 401 displays the number of printable sheets and the like through the print properties of the host 400.

Therefore, a first embodiment in which the present invention is applied to such an image forming apparatus will be described with reference to FIG.
In this embodiment, as described above, ink is replenished and supplied from the ink cartridge 10 to the head tank 35 via the supply tube 26 by the supply pump 241 of the supply unit 24.

  Further, the surface (nozzle surface) on which the nozzles of the recording head 34 are formed is capped by the suction cap 82a of the maintenance / recovery mechanism 81, and the suction pump 811 of the maintenance / recovery mechanism 81 is driven so that the nozzle can be removed from the nozzle via the suction tube 812. The ink in the head tank 35 can be sucked by sucking the ink. The sucked waste ink is discharged to a waste liquid tank 813.

  Further, the negative pressure is formed in the head tank 35 by operating the suction pump 811 and sucking the recording liquid from the nozzles of the recording head 34 with the recording head 34 capped by the suction cap 82a as described above. I have to. That is, by sucking the recording liquid in the head tank 35, the film-like member 102 tries to restore with the restoring force of the elastic member 103, thereby generating a negative pressure. At this time, the negative pressure detection lever 106 of the head tank 35 is displaced in a direction toward the case main body 101 side as the recording liquid in the head tank 35 is sucked and discharged. The negative pressure detection lever 106 is also displaced in the direction away from the case main body 101 side even when the recording liquid is supplied into the head tank 35.

  Therefore, the opening amount of the negative pressure detection lever 106 can be defined as the relative positional relationship of the carriage 33 with respect to the full tank detection sensor 312. That is, as shown in FIG. 10A, the recording liquid in the head tank 35 is supplied by supplying ink to the head tank 35 in a state where the carriage 33 is at a required position with respect to the full tank detection sensor 312. As the amount increases, the negative pressure detection lever 106 is displaced, and the full tank detection sensor 312 detects the negative pressure detection lever 106. At this time, if a predetermined amount of recording liquid is supplied, the opening amount L1 of the negative pressure detection lever 106 should be reached, but if the negative pressure detection lever 106 is not detected by the full tank detection sensor 312, the supply amount Will be lacking.

  Further, as shown in FIG. 10B, the recording liquid as the contained material is sucked from the head tank 35 while the negative pressure detection lever 106 of the head tank 35 is detected by the full tank detection sensor 312. As the amount of recording liquid in the head tank 35 decreases, the negative pressure detection lever 106 is displaced and is not detected by the full tank detection sensor 312. At this time, if a predetermined amount of recording liquid is sucked from the head tank 35, the negative pressure detection lever 106 becomes the closing amount L2 and is not detected by the full tank detection sensor 312, but is detected by the full tank detection sensor 312. If the state is maintained, the suction amount is insufficient (the negative pressure is not sufficient).

  However, the amount of displacement of the negative pressure detection lever 106 is not always constant depending on the individual head tanks 35 and varies. Therefore, when the negative pressure detection lever 106 having a relatively large displacement when a predetermined amount of recording liquid is sucked from the head tank 35 is provided, the negative pressure is also detected when the recording liquid is supplied to the head tank 35. Although the detection lever 106 has not completed the supply of the predetermined amount, it is detected by the full tank detection sensor 312 and the filling is insufficient (supply amount is insufficient). On the other hand, when the negative pressure detection lever 106 having a relatively small displacement when a predetermined amount of recording liquid is sucked from the head tank 35 is provided, the recording liquid is supplied to the head tank 35. However, since the negative pressure detection lever 106 is not detected by the full tank detection sensor 312 even though the supply of the predetermined amount is completed, it is overfilled.

  Therefore, in this embodiment, the displacement amount (close amount) of the negative pressure detection lever 106 when a predetermined amount of recording liquid is sucked from the head tank 35 is stored, and the stored negative pressure detection lever 106 is stored. Based on the displacement amount and the displacement amount of the negative pressure detection lever 106 that is displaced by supplying the recording liquid to the head tank 35, the supply amount of the recording liquid to the head tank 35 is controlled.

That is, the replenishing and supplying operation of the ink that is the recording liquid to the sub tank 35 in the first embodiment will be described with reference to FIG.
In this embodiment, the displacement amount of the negative pressure detection lever 106 with respect to the ink suction amount when the operation of forming the negative pressure in the head tank 35 is performed is stored in the nonvolatile memory (EEPROM) 315 as lever closing amount data. Yes. The amount of lever closing when the negative pressure is generated is that the negative pressure detecting lever 106 is displaced (closed) by sucking ink as a contained amount from the head tank 35 by a predetermined suction amount. Therefore, the displacement amount (close amount) of the negative pressure detection lever 106 at this time is stored as the movement amount (or position) of the carriage 33.

  Therefore, when a predetermined amount of ink replenishment operation for the head tank 35 is started, the opening amount of the negative pressure detection lever 106 with respect to the predetermined amount to be supplied is confirmed. Then, the opening amount of the negative pressure detection lever 106 with respect to a predetermined amount is determined with reference to the lever closing amount data when the negative pressure is formed. The relative positional relationship between the carriage 33 and the full tank detection sensor 312 is determined by an amount corresponding to the determined opening amount (the carriage 33 is moved relative to the full tank detection sensor 312 to a position corresponding to the determined opening amount). ).

  Thereafter, ink is supplied from the main tank 10 to the head tank 35 and ink supply is continued until the full tank detection sensor 312 detects the negative pressure detection lever 106. Then, when the full tank detection sensor 312 detects the negative pressure detection lever 106, the ink supply is stopped, and a predetermined amount of ink replenishment operation is stopped.

  That is, when a predetermined amount of ink is supplied to the head tank 35, a predetermined amount of ink is stored from a storage unit (memory) that stores the amount of displacement of the negative pressure detection lever 106 with respect to the ink suction amount when the negative pressure is formed. The amount of displacement of the negative pressure detection lever 106 when ink is supplied is calculated, and control is performed so that ink is supplied to aim at the amount of displacement.

  Therefore, even if there is a variation in the amount of displacement of the negative pressure detection lever 106, the amount of displacement of the negative pressure detection lever 106 with respect to a specific predetermined amount of ink supply is defined for each head tank 35, so a highly accurate replenishment amount Ink replenishment can be performed. As a result, an accurate negative pressure can be formed by the negative pressure forming operation, and image quality deterioration and ink leakage due to insufficient negative pressure can be prevented.

  As described above, each head tank is provided with means for controlling the replenishment of the recording liquid to the head tank based on the displacement amount of the displacement member with respect to the predetermined content suction amount and the displacement amount of the displacement member accompanying the replenishment of the recording liquid. The variation in the displacement amount of the displacement member is canceled, and a very precise recording liquid can be supplied for each head tank.

  In this case, by storing the displacement amount of the displacement member with respect to the predetermined content suction amount as a fixed value in advance, it is possible to supply a very precise recording liquid for each head tank without requiring complicated processing. .

  In addition, by using the amount of displacement when the recording liquid in the head tank is sucked by a predetermined amount as the amount of displacement with respect to the predetermined content suction amount of the displacement member, it is possible to supply a very precise recording liquid with a very simple configuration. It can be carried out. Further, as described above, by using the displacement amount of the displacement member at the time of forming the negative pressure, the displacement amount of the displacement member with respect to the replenishment amount is defined within a range in which the image forming apparatus is normally used as a negative pressure forming operation. Therefore, it is possible to supply recording liquid very efficiently and accurately.

Next, the replenishing and supplying operation of the ink that is the recording liquid to the sub tank 35 in the second embodiment of the present invention will be described with reference to FIG.
Here, the lever closing amount data at the time of negative pressure formation stored in the storage means in the first embodiment is used to draw a predetermined amount of ink from the head tank 35 and apply a negative pressure to the head tank 35. A process of updating is performed every time the operation of forming (negative pressure forming operation) is performed. Then, referring to the updated lever closing amount data, the amount of displacement of the negative pressure detection lever 106 that can be expected when supplying a predetermined amount of ink is calculated, and ink is supplied aiming at the amount of displacement. To control.

  Thus, by updating the displacement amount of the negative pressure detection lever (displacement means) with respect to the predetermined recording liquid suction amount for each negative pressure forming operation, it is possible to cope with variations in the displacement amount of the displacement means due to the environment. Thus, more accurate supply can be performed.

Next, the negative pressure forming operation in the third embodiment of the present invention will be described with reference to FIG.
When ink is replenished and supplied to the head tank 35, a negative pressure forming operation is started in order to form a negative pressure in the head tank 35, and the target amount of displacement of the negative pressure detection lever 106 is set at the time of negative pressure formation. This is determined with reference to the lever closing amount data.

  Then, ink suction from the nozzles of the recording head 34 is started and ink suction is performed until the amount of displacement of the negative pressure detection lever reaches the target value. When the target value is reached, ink suction is stopped and the negative pressure forming operation is terminated. To do.

  By performing such control, for example, even when the performance of the suction pump is deteriorated for some reason, negative pressure can be formed with very high accuracy by repeatedly performing ink suction. In the above-described processing, if the target value is not satisfied when the displacement amount of the negative pressure detection lever is determined, the displacement amount of the negative pressure lever and the target displacement amount (target value) are insufficient. It is also possible to calculate the amount of displacement being performed and control the ink suction amount in accordance with the calculated amount of displacement, and in this case as well, negative pressure can be formed with very high accuracy.

Next, the negative pressure forming operation in the fourth embodiment of the present invention will be described with reference to FIG.
When ink is replenished and supplied to the head tank 35, a negative pressure forming operation is started in order to form a negative pressure in the head tank 35, and the target amount of displacement of the negative pressure detection lever 106 is set at the time of negative pressure formation. This is determined with reference to the lever closing amount data.

  Then, a predetermined amount of ink is sucked from the nozzles of the recording head 34 to determine whether or not the negative pressure detection lever displacement amount has reached the target value. Even if the predetermined amount of ink suction is performed, the negative pressure detection lever displacement is When the amount has not reached the target value, the negative pressure forming operation is started again from the beginning. When the predetermined amount of ink suction is performed and the negative pressure detection lever displacement amount reaches the target value, the ink suction is stopped and the negative pressure is reduced. The pressure forming operation is terminated.

  By performing such control, for example, even when the performance of the suction pump is deteriorated for some reason, it is possible to form an accurate negative pressure by repeating the negative pressure forming operation. Ink leakage and image quality degradation can be prevented.

Next, a fifth embodiment of the present invention will be described with reference to FIGS. 15 and 16.
In this embodiment, as shown in FIG. 15, an air suction pump 502 that sucks air in the head tank 35 is provided, and the air suction pump 502 is driven and controlled from the control unit 300.
In the negative pressure forming operation in this embodiment, as shown in FIG. 16, when ink is replenished and supplied to the head tank 35, the negative pressure forming operation is started to form a negative pressure in the head tank 35. Then, the target amount of displacement of the negative pressure detecting lever 106 is determined with reference to the lever closing amount data when the negative pressure is generated.

  Then, a predetermined amount of ink is sucked from the nozzles of the recording head 34 to determine whether or not the negative pressure detection lever displacement amount has reached the target value. Even if the predetermined amount of ink suction is performed, the negative pressure detection lever displacement is When the amount does not reach the target value, the air suction pump 502 is driven to suck a predetermined amount of air in the head tank 35, and then a predetermined amount of ink is sucked to set the negative pressure detection lever displacement amount to the target value. When the pressure reaches the negative pressure, the negative pressure forming operation is terminated.

  By performing such control, for example, even if the performance of the suction pump is degraded for some reason, it is possible to create a negative pressure in the sub tank using an air suction pump as an alternative, and recording It is possible to prevent the recording liquid from leaking or the image quality from being deteriorated due to the negative pressure abnormality due to the performance deterioration of the liquid suction pump.

  In each of the above embodiments, since the recording liquid is sucked from the head tank to form a negative pressure, the control is performed based on the displacement amount of the displacement member when a predetermined amount of the recording liquid is sucked from the head tank. However, in the case where negative pressure is formed by sucking air from the head tank, it can be configured to control based on the displacement amount of the displacement member when sucking a predetermined amount of air from the head tank, Even in this way, precise recording liquid supply amount control can be performed with a simple configuration.

  The configuration of the head tank is not limited to that of the above embodiment, and any head tank that can perform a negative pressure recovery operation may be used. The image forming apparatus according to the present invention is not limited to a printer having a single function configuration, and may be an image forming apparatus having a composite function such as a printer / facsimile / copying.

FIG. 3 is a perspective explanatory view seen from the front side of the ink jet recording apparatus as the image forming apparatus according to the present invention. It is a side schematic block diagram explaining the whole structure of the mechanism part of the apparatus. It is principal part plane explanatory drawing of the mechanism part. It is a perspective explanatory view showing an example of a head tank of the device. It is a disassembled perspective explanatory view of the head tank. It is typical side surface explanatory drawing of the head tank. It is typical cross-sectional explanatory drawing which follows the AA line of FIG. It is block explanatory drawing which shows the outline | summary of the control part of the apparatus. It is typical explanatory drawing with which it uses for description of 1st Embodiment of this invention. FIG. 6 is a schematic explanatory view for explaining the detection of the opening amount of the negative pressure detection lever. It is a flowchart with which it uses for description of an effect | action of the embodiment. It is a flowchart with which it uses for description of 2nd Embodiment of this invention. It is a flowchart with which it uses for description of 3rd Embodiment of this invention. It is a flowchart with which it uses for description of 4th Embodiment of this invention. It is typical explanatory drawing with which it uses for description of 5th Embodiment of this invention. It is a flowchart with which it uses for description of the embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Main body 2 ... Paper feed tray 3 ... Paper discharge tray 4 ... Cartridge loading part 10k, 10c, 10m, 10y ... Ink cartridge 33 ... Carriage 34 ... Recording head 35 ... Head tank 36 ... Ink supply tube 51 ... Conveying belt 30 ... Control unit 100 ... Ink container 102 ... Film-like member 103 ... Elastic member 106 ... Negative pressure detection lever 312 ... Full tank detection sensor

Claims (10)

  A head tank having a displacement member that supplies the recording liquid to a recording head that discharges recording liquid droplets from a nozzle, and is replenished and supplied from the main tank on the apparatus main body side, and is displaced according to the amount of contained material. And means for controlling replenishment of the recording liquid to the head tank based on a displacement amount of the displacement member with respect to a predetermined content suction amount and a displacement amount of the displacement member accompanying the replenishment of the recording liquid. An image forming apparatus comprising the image forming apparatus.   2. The image forming apparatus according to claim 1, wherein a displacement amount of the displacement member with respect to a predetermined content suction amount is a displacement amount when a predetermined amount of recording liquid is sucked.   2. The image forming apparatus according to claim 1, wherein a displacement amount of the displacement member with respect to a predetermined content suction amount is a displacement amount when a predetermined amount of air is sucked.   2. The image forming apparatus according to claim 1, wherein the displacement amount of the displacement member with respect to a predetermined content suction amount is when the recording liquid is sucked from the head tank to form a negative pressure of the head tank. An image forming apparatus characterized in that the amount of displacement with respect to the recording liquid suction amount.   5. The image forming apparatus according to claim 4, wherein a displacement amount of the displacement member with respect to a predetermined content suction amount is updated each time an operation for forming a negative pressure of the head tank is performed. .   2. The image forming apparatus according to claim 1, wherein a displacement amount of the displacement member with respect to a predetermined content suction amount is a fixed value determined in advance for the head tank.   7. The image forming apparatus according to claim 4, wherein when the recording liquid is sucked from the head tank to perform a negative pressure of the head tank, the displacement amount of the displacement member is abnormal. An image forming apparatus characterized in that the operation of forming a negative pressure is repeatedly performed until the displacement amount becomes normal.   7. The image forming apparatus according to claim 4, wherein when the recording liquid is sucked from the head tank and the negative pressure of the head tank is formed, the displacement amount of the displacement member is abnormal. An image forming apparatus characterized in that recording liquid suction is repeatedly performed until a displacement amount can be regarded as normal.   7. The image forming apparatus according to claim 4, wherein when the recording liquid is sucked from the head tank to perform a negative pressure of the head tank, the displacement amount of the displacement member is abnormal. An image forming apparatus characterized in that air suction is repeatedly performed until a displacement amount can be regarded as normal. 5. The image forming apparatus according to claim 4, wherein the displacement amount of the displacement member when accumulating the negative pressure of the head tank is accumulated and accumulated when performing the negative pressure of the head tank. An image forming apparatus characterized by determining normal / abnormal of the negative pressure formation result of the head tank with reference to the past displacement amount.

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