JP2011051317A - Ink-jet recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink supply device carrying out purging operation with low-cost constitution, and an ink-jet recording device including the ink supply device. <P>SOLUTION: The ink supply device includes an ink tank chamber of casing structure in which an ink tank filled with ink is stored; a pump directly or indirectly pressurizing the inside of the ink tank chamber; a pressure sensor detecting the internal pressure of the ink tank chamber; a sub-tank supplied with ink from the ink tank stored in the ink tank chamber, and communicating with an ejection head for ejecting ink; a sub-tank chamber of casing structure for storing the sub-tank inside; a first on-off valve allowing the sub-tank to communicate with the ink tank stored in the ink tank chamber or intercepting the communication; a second on-off valve allowing the ink tank chamber to communicate with the sub-tank chamber or intercepting the communication; and a control means for controlling the pump and the first and second on-off valves using the detection values of the pressure sensor. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an ink jet recording apparatus that forms an image or prints a text by dropping ink from a nozzle of an ejection head and adhering it to a sheet, and in particular, it is detachable installed in a sealed case attached to the main body side. The present invention relates to an ink jet recording apparatus that applies pressure to a main tank and sends ink to a sub tank side.

  Conventionally, an ink jet recording apparatus (printer) is known. This ink jet recording apparatus performs image formation and text printing by applying ink droplets from the nozzles of an ejection head and attaching them to paper.

  As an ink jet recording apparatus, a container in which an ink storage container and a cartridge including a case are removable is widely used. However, an object of application of the present invention is an airtight case attached to the main body ( In the ink jet recording apparatus, pressure is applied to a removable main tank (formed of a flexible material) installed in an ink tank chamber), and ink is delivered to the sub tank side.

  FIG. 1 is a view showing a conventional ink jet recording apparatus 100 having such an embodiment. In the ink jet recording apparatus 100 shown in the figure, the inside of the ink tank chamber is pressurized by the pump 111, and when the amount of ink in the sub tank falls below a predetermined amount, the on-off valve 101 is opened to supply ink from the ink tank to the sub tank. Then, ink is supplied from the sub tank to the nozzles, and ink is dropped at the nozzles.

  In addition, the following purge operation is performed in order to recover the discharge performance of the nozzle. First, by closing the sub tank chamber containing the sub tank and the on-off valves 101, 103, 104, the sub tank is sealed, the sub tank is pressurized by the pump, the pressure in the sub tank chamber is increased to a predetermined pressure, and then the on-off valve 104 By opening the, a rapid pressure fluctuation is applied to the ink in the head, and the thickened ink and bubbles in the vicinity of the nozzles in the head are discharged to restore the ejection performance.

  Moreover, the invention about the inkjet recording device of the similar aspect is disclosed (for example, refer patent document 1). This ink jet recording apparatus has a configuration in which a pump is connected only to a sub tank and an air tank communicated with the sub tank. During the purge operation, the sub tank is pressurized with the air sucked from the sub tank and stored in the air tank so that the ink flows out from the head.

  However, the configuration shown in FIG. 1 requires at least two pumps, which increases the size and cost of the apparatus.

  In the configuration described in Patent Document 1, although a single pump is sufficient, it is necessary to provide a plurality of on-off valves for shutting off the liquid (in the case of color printing, a plurality of colors for each color). Cost increases. An on-off valve for blocking or allowing liquid to pass through is generally more expensive than an on-off valve for blocking or passing gas.

  SUMMARY An advantage of some aspects of the invention is to provide an ink supply apparatus capable of performing a purge operation with an inexpensive configuration, and an ink jet recording apparatus including the ink supply apparatus. .

In order to achieve the above object, the first aspect of the present invention provides:
An ink tank chamber having a housing structure in which an ink tank filled with ink is stored;
A pump capable of directly or indirectly pressurizing the inside of the ink tank chamber;
A pressure sensor capable of detecting the pressure inside the ink tank chamber;
A sub-tank that is supplied with ink from an ink tank housed in the ink tank chamber and communicates with a discharge head that discharges the ink;
A sub-tank chamber having a housing structure for accommodating the sub-tank inside;
A first on-off valve for communicating or blocking the sub tank and the ink tank stored in the ink tank chamber;
A second on-off valve for communicating or blocking the ink tank chamber and the sub tank chamber;
Control means for controlling the pump and the first and second on-off valves using the detection value of the pressure sensor;
An ink supply device.

  According to the first aspect of the present invention, the purge operation can be performed with an inexpensive configuration.

In the first aspect of the present invention,
The control means is, for example,
At the time of ink supply control for performing normal ink supply, the first on-off valve and the second on-off valve are closed, and the pump is driven to pressurize the inside of the ink tank chamber. The first on-off valve is changed from a closed state to an open state, and ink is supplied from the ink tank to the sub tank.
At the time of purge control for recovering the ejection performance of the ejection head, the first on-off valve and the second on-off valve are closed and the pump is driven to pressurize the interior of the ink tank chamber. And means for controlling the pump and the first and second on-off valves so that the second on-off valve is changed from a closed state to an open state and ink is supplied from the sub tank to the head portion.

In the first aspect of the present invention,
The target pressure value inside the ink tank chamber during the ink supply control may be lower than the target pressure value inside the ink tank chamber during the purge control.

The second aspect of the present invention is:
1 is an inkjet recording apparatus including the ink supply apparatus according to the first aspect of the present invention.

  According to the second aspect of the present invention, the purge operation can be performed with an inexpensive configuration.

  According to the present invention, it is possible to provide an ink supply apparatus capable of performing a purge operation with an inexpensive configuration, and an ink jet recording apparatus including the ink supply apparatus.

1 is a diagram illustrating a conventional inkjet recording apparatus 100. FIG. 1 is a diagram schematically illustrating the configuration of an inkjet recording apparatus 1 according to a first embodiment of the present invention. It is a flowchart which shows the flow of the process in the ink supply control performed by the controller 60 which concerns on 1st Example. It is a flowchart which shows the flow of the process in the purge control performed by the controller 60 which concerns on 1st Example. It is a figure which shows typically the structure of the inkjet recording device 2 which concerns on 2nd Example of this invention. It is a flowchart which shows the flow of the process in the ink supply control performed by the controller 60 which concerns on 2nd Example. It is a flowchart which shows the flow of the process in the purge control performed by the controller 60 which concerns on 2nd Example. It is the figure which showed focusing on parts other than the ink supply structure in the inkjet recording device 2 of a present Example.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings.

  Hereinafter, an ink jet recording apparatus according to an embodiment of the present invention will be described with reference to the drawings. The following ink jet recording apparatus performs image formation and text printing by dropping ink from nozzles of an ejection head and adhering them to paper.

<First embodiment>
FIG. 2 is a diagram schematically showing the configuration of the inkjet recording apparatus 1 according to the first embodiment of the present invention. The inkjet recording apparatus 1 shown in this figure performs monochromatic printing. However, as will be described later, the present invention can also be applied to an inkjet recording apparatus that performs color printing.

  The ink jet recording apparatus 1 includes an ink tank chamber 10, a sub tank chamber 20, a distributor 30, a discharge head 40, a wiper 50, and a controller 60 as main components. The ink jet recording apparatus 1 includes an on-off valve 71 for blocking or allowing ink to pass therethrough and a plurality of on-off valves 72 to 74 for blocking or passing gas. Note that the configuration in which the distributor 30, the ejection head 40, and the wiper 50 are removed from the inkjet recording apparatus 1 corresponds to an “ink supply apparatus” in the claims.

  The ink tank chamber 10 is an airtight casing formed of metal or the like, and a removable ink tank 12 is accommodated therein. The ink tank 12 is made of a flexible material and contains ink.

  The ink tank chamber 10 is provided with a pump 14, a pressure sensor 16, and an on-off valve 72. The pump 14 can pressurize the inside of the ink tank chamber 10 by pumping air into the ink tank chamber 10. The pressure sensor 16 measures the atmospheric pressure inside the ink tank chamber 10 and outputs it to the controller 60. The on-off valve 72 is for blocking or communicating the inside of the ink tank chamber 10 with the atmosphere, and is a controller that is closed when the pump 14 is operated to pressurize the inside of the ink tank chamber 10. 60.

  Similar to the ink tank chamber 10, the sub tank chamber 20 is an airtight housing. The sub tank chamber 20 has a sub tank 22 assembled therein. Similar to the ink tank 12, the sub tank 22 is formed of a flexible material, and stores the ink supplied from the ink tank 16.

  The sub tank chamber 20 is provided with a sub tank upper surface position detection sensor 24 for detecting the upper surface position of the sub tank 22 and an on-off valve 73. The sub tank upper surface position detection sensor 24 includes, for example, a lever that can rotate around a predetermined axis, and a sensor such as a resolver that can detect the rotation angle. When the filling amount of the sub tank 22 increases, the upper surface of the sub tank 22 presses the lever upward to rotate the lever, so that the filling amount of the sub tank 22 is detected as a rotation angle by the sensor. The on-off valve 73 is for shutting off or communicating the inside of the sub tank chamber 20 with the atmosphere. As will be described later, the on / off valve 73 is closed when the inside of the sub tank chamber 20 is pressurized by the operation of the pump 14. Controlled by the controller 60.

  The ink tank 12 and the sub tank 22 communicate with each other via an ink supply path A, and an opening / closing valve 71 for blocking or passing ink is attached in the middle of the ink supply path A. Further, the ink tank chamber 10 and the sub tank chamber 20 communicate with each other via a gas passage C, and an open / close valve 74 for blocking or passing the gas is attached in the middle of the gas passage C.

  The distributor 30 distributes and supplies ink to a plurality of heads included in the ejection head 40. The plurality of heads of the ejection head 40 eject ink from the nozzles by driving the internal piezo elements by a head controller (not shown).

  The sub tank 22, the distributor 30, and the ejection head 40 communicate with each other through the ink supply path B. A negative pressure is generated in the ink inside the head due to a water head difference between the upper surface position of the sub tank 22 and the upper surface positions of the plurality of heads of the discharge head 40.

  The wiper 50 operates to wipe out ink that has flowed out of the plurality of heads and adhered to the nozzle surface when the inkjet recording apparatus 1 performs a purge operation. For example, when the ejection head 40 moves to a predetermined position during the purge operation, the wiper 50 is attached to a position facing the wiper 50. In addition, a removable tray for collecting the ink ejected by the purge operation is attached to the predetermined position.

  The controller 60 is a microcomputer, for example, and monitors the outputs of the pressure sensor 16 and the sub tank upper surface position detection sensor 24. Then, the ink supply control and the purge control are performed by controlling the opening / closing of the on-off valves 71 to 74 and the driving / stopping of the pump 14.

  Hereinafter, ink supply control and purge control executed by the controller 60 will be described.

  FIG. 3 is a flowchart showing a process flow in the ink supply control executed by the controller 60. This flow is started when the ink jet recording apparatus 1 is turned on, for example.

  First, the controller 60 closes the on-off valves 71, 72, and 74 (S100).

  And the output value of the pressure sensor 16 is read (S102), and it is determined whether the output value of the pressure sensor 16 is below the lower limit of the target range (S104).

  When the output value of the pressure sensor 16 is below the lower limit of the target range, the pump 14 is driven to pressurize the inside of the ink tank chamber 10 until the output value of the pressure sensor 16 reaches the upper limit of the target range (S106). ~ S110).

  Subsequently, the controller 60 reads the detection value of the sub tank upper surface position detection sensor 24 (S112), and determines whether or not the detection value of the sub tank upper surface position detection sensor 24 is equal to or lower than the lower limit of the target range (S114). When the detection value of the sub tank upper surface position detection sensor 24 is less than or equal to the lower limit of the target range, the on-off valve 71 is opened until the detection value of the sub tank upper surface position detection sensor 24 reaches the upper limit of the target range. Ink is supplied to the sub tank 22 (S116 to S120).

  Then, for example, the processes of S102 to S120 are repeatedly executed until the power of the inkjet recording apparatus 1 is turned off by the user.

  FIG. 4 is a flowchart showing a process flow in the purge control executed by the controller 60. This flow is started at a predetermined timing (for example, when the power is turned on or the ink tank 12 is replaced, every predetermined time, when a predetermined operation is performed by the user, etc.).

  First, the controller 60 closes the on-off valves 71, 72, and 74 (S200).

  Then, the pump 14 is driven to pressurize the ink tank chamber 10 until the output value of the pressure sensor 16 reaches a predetermined value (S202 to S206). This predetermined value is preferably higher than the upper limit of the target range in the ink supply control.

  Next, the controller 60 closes the on-off valve 73 (S208), and then opens the on-off valve 74 (S210). Then, after a predetermined time has elapsed (S212), the on-off valve 74 is closed and the on-off valve 73 is opened (S214). As a result, the pressurized air inside the ink tank chamber 10 is supplied to the sub tank chamber 20, and as a result, ink is rapidly supplied from the sub tank chamber 20 to the ejection head 40. Viscous ink and bubbles can be discharged.

  Further, the controller 60 waits for a certain time (which may be different from the certain time in S210) to pass (S216), and then operates the wiper 50 to wipe off ink remaining on the nozzle surface (S218).

  According to the ink jet recording apparatus 1 and the ink supply apparatus of the present embodiment described above, it is sufficient to provide a single pump for pumping gas and a single on-off valve for blocking or allowing liquid to pass. The purge operation can be performed with a simple configuration.

<Second embodiment>
FIG. 5 is a diagram schematically showing the configuration of the inkjet recording apparatus 2 according to the second embodiment of the present invention. The ink jet recording apparatus 2 shown in the figure is configured as an ink jet recording apparatus that performs color printing. In addition, the same code | symbol is attached | subjected about the component which is common in 1st Example.

  The ink jet recording apparatus 2 mainly includes an ink tank unit having ink tank chambers 10a to 10d, a sub tank unit having sub tank chambers 20a to 20d, a head unit having discharge heads 40a to 40d, and a controller 60. Is provided. Although a distributor and a wiper are not shown, they may have the same configuration as that of the first embodiment. Further, the ink jet recording apparatus 2 includes open / close valves 71a to 71d for blocking or passing ink, and a plurality of open / close valves 72 to 74 and 75a to 75d for blocking or passing gas. . A configuration in which the distributor, the ejection heads 40a to 40d, and the wiper are removed from the inkjet recording apparatus 2 corresponds to an “ink supply apparatus” in the claims.

  The ink tank chambers 10a to 10d are airtight casings formed of metal or the like, and detachable ink tanks 12a to 12d are accommodated therein. Each of the ink tanks 12a to 12d is formed of a flexible material, and is filled with inks of different colors such as black (Bk), magenta (M), cyan (C), and yellow (Y). .

  Each ink tank chamber communicates with a gas passage D to which a pump 14, a pressure sensor 16, and on-off valves 72 and 73 are attached. The pump 14 pumps air into the gas passage D, thereby pumping air into each ink tank chamber and pressurizing the inside of each ink tank chamber. The pressure sensor 16 measures the atmospheric pressure inside the gas passage D communicating with each ink tank chamber and outputs it to the controller 60. The on-off valve 72 is for blocking or communicating the inside of the gas passage D with the atmosphere, and the controller 60 is in a closed state when the pump 14 is operated to pressurize the inside of the ink tank chamber 10. Controlled by

  The sub tank chambers 20a to 20d are air-tight housings similar to the ink tank chambers 10a to 10d. The sub tank chambers 20a to 20d have sub tanks 22a to 22d assembled therein. Similar to the ink tanks 12a to 12d, the sub tanks 22a to 22d are made of a flexible material and store ink supplied from the ink tanks 12a to 12d.

  The sub tank chambers 20a to 20d are attached with sub tank upper surface position detection sensors 24a to 24d for detecting the upper surface positions of the sub tanks 22a to 22d, respectively.

  The sub tank chambers 20a to 20d communicate with the gas passage E to which the on / off valve 73 is attached via the on / off valves 75a to 75d. Further, the gas passage D and the gas passage E communicate with each other via an on-off valve 74 (for convenience, the gas passage D and the gas passage E are integrally formed, and the on-off valve 74 is attached in the middle. May be) The on-off valve 73 is for shutting off or communicating the inside of each sub tank chamber with the atmosphere. As will be described later, the on / off valve 73 is closed when the inside of each sub tank chamber is pressurized by the operation of the pump 14. Controlled by the controller 60.

  The ink tanks 12a to 12d and the sub tanks 22a to 22d communicate with each other via the ink supply paths Aa to Ad. On the way of the ink supply paths Aa to Ad, the open / close valves 71a to 71a for blocking or allowing the ink to pass are provided. 71d is attached.

  Each sub tank and each ejection head communicate with each other through ink supply paths Ba to Bd. A negative pressure is generated in the ink inside the head due to a water head difference between the upper surface position of each sub-tank and the upper surface positions of a plurality of heads included in each ejection head.

  The controller 60 is a microcomputer, for example, and monitors the outputs of the pressure sensor 16 and the sub tank upper surface position detection sensors 24a to 24d. Then, ink supply control and purge control are performed by controlling opening / closing of each on-off valve and driving / stopping of the pump 14.

  Hereinafter, ink supply control and purge control executed by the controller 60 will be described.

  FIG. 6 is a flowchart showing the flow of processing in the ink supply control executed by the controller 60. This flow is started, for example, when the inkjet recording apparatus 2 is turned on.

  First, the controller 60 closes the on-off valves 71a to 71d, 72, and 74 (S300).

  And the output value of the pressure sensor 16 is read (S302), and it is determined whether the output value of the pressure sensor 16 is below the lower limit of the target range (S304).

  If the output value of the pressure sensor 16 is below the lower limit of the target range, the pump 14 is driven to pressurize the inside of each ink tank chamber until the output value of the pressure sensor 16 reaches the upper limit of the target range (S306). To S310).

  Subsequently, the controller 60 reads the detection values of the sub-tank upper surface position detection sensors 24a to 24d (S312), and the detection values of the sub-tank upper surface position detection sensors 24a to 24d are not more than the lower limit of the target range. Is determined (S314). When there are detection values of the sub tank upper surface position detection sensors 24a to 24d that are below the lower limit of the target range, the on-off valve 71a is used until the detection value of the sub tank upper surface position detection sensor reaches the upper limit of the target range. The corresponding one of -71d (connected to the sub-tank whose detected value is below the lower limit of the target range) is opened, and ink is supplied from the corresponding ink tank to the sub-tank (S316-S320).

  Then, for example, the processes of S302 to S320 are repeatedly executed until the power of the inkjet recording apparatus 2 is turned off by the user.

  FIG. 7 is a flowchart showing a flow of processing in purge control executed by the controller 60. This flow is started at a predetermined timing (for example, when the power is turned on or the ink tank 12 is replaced, every predetermined time, when a predetermined operation is performed by the user, etc.).

  First, the controller 60 closes the on-off valves 71a to 71d, 72, and 74 (S400).

  Then, the pump 14 is driven to pressurize the inside of each ink tank chamber until the output value of the pressure sensor 16 reaches a predetermined value (S402 to S406). This predetermined value is preferably higher than the upper limit of the target range in the ink supply control.

  Next, the controller 60 closes the open / close valve 73 (S408), and then opens the open / close valves 74 and 75a to 75d (S410). Then, after a lapse of a certain time (S412), the on-off valves 74 and 75a to 75d are closed and the on-off valve 73 is opened (S414). As a result, the pressurized air inside the ink tank chambers 10a to 10d is supplied to the sub tank chambers 20a to 20d, and as a result, the ink is rapidly supplied from the sub tank chamber 20 to the ejection heads 40a to 40d. It is possible to discharge thickened ink and bubbles in the vicinity of the inner nozzle.

  Further, the controller 60 waits for a certain time (which may be different from the certain time in S510) to pass (S416), and then operates the wiper to wipe off the ink remaining on the nozzle surface (S418).

  According to the inkjet recording apparatus 2 and the ink supply apparatus of the present embodiment described above, it is sufficient to provide a single pump for pumping gas and a single on / off valve for blocking or passing liquid for each color. The purge operation can be performed with an inexpensive configuration.

<Application example>
FIG. 8 is a diagram mainly showing a portion other than the ink supply structure in the inkjet recording apparatus 2 of the present embodiment.

  The ink jet recording apparatus 2 includes an automatic paper feeding device, and includes a paper feeding unit 202, a paper feeding unit 203 (belt conveying device), a paper discharging unit 204, an ink jet head unit 201, and a sub tank and an ink cartridge (not shown). Tank). Therefore, these are divided into items and will be described in order as (A) paper feed unit, (B) paper feed unit, (C) recording head unit, and (D) paper discharge unit.

(A) Paper feed unit
The paper feeding unit 202 is configured such that a pressure plate 221 on which recording paper P as a sheet material is stacked and a feeding rotating body 222 that feeds the recording paper P are attached to the base 220. The pressure plate 221 can rotate around a rotation shaft 221 a coupled to the base 220 and is urged by the pressure plate spring 224 to the feeding rotating body 22.

  A separation pad 225 made of a material having a large coefficient of friction such as a working skin for preventing double feeding of the recording paper P is provided at a portion of the pressure plate 221 facing the feeding rotating body 222. Further, the base 220 covers a corner in one direction of the recording paper P as a sheet material, and a separation claw 226 for separating the recording paper P one by one, the pressure plate 221 and the feeding rotating body 222 abut. A release cam (not shown) for releasing is provided.

  In the above configuration, the release cam pushes the pressure plate 221 down to a predetermined position in the standby state. Thereby, the contact between the pressure plate 221 and the feeding rotating body 222 is released. In this state, when the driving force of the conveying roller 232 is transmitted to the feeding rotary body 222 and the release cam by a gear or the like, the release cam moves away from the pressure plate 221 and the pressure plate 221 rises, and the feeding rotary body 222 is moved. And the recording paper P come into contact with each other, and the recording paper P is picked up and started to be fed with the rotation of the feeding rotating body 222, separated one by one by the separation claw 226, and sent to the paper feeding unit 203.

  The feeding rotary member 222 rotates until the recording paper P is fed into the paper feeding unit 203, enters a standby state in which the contact between the recording paper P and the feeding rotary member 222 is released again, and the driving force from the transport roller 232 is applied. Cut off.

  Reference numeral 290 denotes a feeding rotating body for manual sheet feeding. The recording paper P placed on the manual feed tray 291 is fed by the feeding rotating body 290 according to the recording command signal of the computer, and conveyed to the conveying roller 232 section.

(B) Paper Feed Unit The paper feed unit 203 has a transport belt 231 provided with a carrying surface that sucks and transports the recording paper P and a PE sensor (paper edge sensor (photocoder or the like)) (not shown).

  The conveyor belt 231 is driven by a driving roller 234 and is wound around a conveyor roller 232 and a pressure roller 235 that are driven rollers.

  The transport roller 232 and the drive roller 234 are rotatably attached to the platen 230, and the pressure roller 235 is rotatably attached to the other end of the arm 250 that is swingably attached to the platen 230. The arm 250 is pressed by the spring 251 to apply tension to the conveyor belt 231. The platen 230 is positioned below the conveyor belt 231 and serves to hold the conveyor belt 231.

  A conveying belt 231 and a driven pinch roller 233 are in contact with each other at a position facing the conveying roller 232. The pinch roller 233 is pressed against the transport belt 231 by a spring (not shown) to guide the recording paper P to the recording unit.

  Further, an upper guide 227 and a lower guide 228 for guiding the recording paper P are disposed at the entrance of the paper feeding unit 203 to which the recording paper P is conveyed. Further, the upper guide 227 is provided with a PE sensor lever 229 that transmits detection of the leading edge and the trailing edge of the recording paper P to a PE sensor (not shown). Further, an inkjet head unit 201 as an image forming unit that forms an image based on image information is provided on the downstream side of the conveyance roller 232 in the recording sheet conveyance direction.

  In the above configuration, the recording paper P sent to the paper feeding unit 203 is guided by the upper guide 227 and the lower guide 228 and sent to the roller pair of the transport roller 232 and the pinch roller 233. At this time, the leading end of the conveyed recording paper P is detected by the PE sensor lever 229 to obtain the printing position of the recording paper P. In addition, the recording paper P is conveyed by the conveyance belt 231 being rotated via a conveyance roller 232 by a paper feed motor described later.

(C) Recording Head Unit The inkjet head unit 201 of the present embodiment is a full in which nozzles that are a plurality of ejection openings are arranged across the entire width of the recording area in a direction (conveying width direction) orthogonal to the conveying direction of the recording paper P. A line type ink jet recording head is used. The inkjet head unit 201 is attached to the head holder 201A, and is arranged at predetermined intervals in the order of 201K (black), 201C (cyan), 201M (magenta), and 201Y (yellow) from the upstream side in the conveyance direction of the recording paper P.

  The ink jet head unit 201 includes a nozzle that ejects ink droplets, a pressurized liquid chamber that communicates with the nozzle, and a pressure generating unit that generates pressure to pressurize ink in the pressurized liquid chamber. By pressurizing the ink in the pressurized liquid chamber with the generated pressure, ink droplets are ejected from the nozzles, and an image is formed on the recording paper P. As the pressure generating means, an electromechanical transducer element using a piezoelectric element is used. The flow dew forming section including the fluid resistance for supplying ink from the pressurized liquid chamber and the common liquid chamber is a full-line type ink jet recording head in which a plurality of nozzles as ejection openings are arranged over the entire width of the recording area in which the present invention is implemented. Yes.

  One end of the inkjet head unit 201 is rotatably fixed by a shaft 271, the protrusion of the head holder 201 </ b> A formed at the other end and the rail 272 are engaged, and the distance between the nozzle surface and the recording paper P (paper) ) Is now specified.

  In this embodiment, an electromechanical conversion element using a piezoelectric element is used. However, the present invention can be applied to any recording head made of a flow path forming member as in the present invention, and an electromechanical conversion element using an electrostatic actuator. Alternatively, a thermal type electrothermal conversion element that discharges liquid with bubbles generated by heating a heater can also be used.

(D) Paper Discharge Unit The paper discharge unit 204 includes a paper discharge roller 241 and a spur 242, and the recording paper P on which an image has been formed by the recording unit is sandwiched and conveyed between the paper discharge roller 241 and the spur 242. The paper is discharged to a paper discharge tray 243.

  The best mode for carrying out the present invention has been described above by using the embodiments. However, the present invention is not limited to these embodiments, and various modifications can be made without departing from the gist of the present invention. And substitutions can be added.

  The present invention can be used in the manufacturing industry of ink jet recording apparatuses.

1, 2 Inkjet recording apparatus 10, 10a, 10b, 10c, 10d Ink tank chamber 12, 12a, 12b, 12c, 12d Ink tank 14 Pump 16 Pressure sensor 20, 20a, 20b, 20c, 20d Sub tank chamber 22, 22a, 22b 22c, 22d Sub tank 24, 24a, 24b, 24c, 24d Sub tank upper surface position detection sensor 30 Distributor 40, 40a, 40b, 40c, 40d Discharge head 50 Wiper 60 Controller 71, 72, 73, 74 On-off valve A, B Ink Supply path C Gas path

Registered Utility Model No. 312757 Publication

Claims (4)

An ink tank chamber having a housing structure in which an ink tank filled with ink is stored;
A pump capable of directly or indirectly pressurizing the inside of the ink tank chamber;
A pressure sensor capable of detecting the pressure inside the ink tank chamber;
A sub-tank that is supplied with ink from an ink tank housed in the ink tank chamber and communicates with a discharge head that discharges the ink;
A sub-tank chamber having a housing structure for accommodating the sub-tank inside;
A first on-off valve for communicating or blocking the sub tank and the ink tank stored in the ink tank chamber;
A second on-off valve for communicating or blocking the ink tank chamber and the sub tank chamber;
Control means for controlling the pump and the first and second on-off valves using the detection value of the pressure sensor;
An ink supply device comprising: The control means includes
At the time of ink supply control for performing normal ink supply, the first on-off valve and the second on-off valve are closed, and the pump is driven to pressurize the inside of the ink tank chamber. The first on-off valve is changed from a closed state to an open state, and ink is supplied from the ink tank to the sub tank.
At the time of purge control for recovering the ejection performance of the ejection head, the first on-off valve and the second on-off valve are closed and the pump is driven to pressurize the interior of the ink tank chamber. And means for controlling the pump and the first and second on-off valves such that the second on-off valve is changed from a closed state to an open state and ink is supplied from the sub tank to the head portion.
The ink supply device according to claim 1. The pressure target value inside the ink tank chamber during the ink supply control is a lower value than the pressure target value inside the ink tank chamber during the purge control.
The ink supply device according to claim 2.   An ink jet recording apparatus comprising the ink supply device according to claim 1.

Images