JP2019142183A - Ink jet recording device, control method therefor, and program - Google Patents

Abstract

To prevent an ink from overflowing from a sub-tank by stopping ink flow from a main tank to the sub-tank when a power source is cut.SOLUTION: An ink jet recording device comprises: a recording head discharging an ink to record on a recording medium; a sub-tank storing the ink to be supplied to the recording head; a main tank reserving the ink to be replenished to the sub-tank; an ink flow path connecting the main tank to the sub-tank; a first valve capable of opening or closing the ink flow path; an air flow path communicating with an air layer in the sub-tank and opened in an ambient air; a second valve capable of opening or closing the air flow path; and negative pressure generating means for making the pressure in the sub-tank negative. In the device, the second valve opens when the power source is cut during the pressure in the sub-tank is made negative by the negative pressure generating means and the ink is replenished from the main tank into the sub-tank in such a state that the first valve opens.SELECTED DRAWING: Figure 6

Description

  The present invention relates to an ink jet recording apparatus, a control method thereof, and a program.

  In Patent Document 1, ink is supplied from the main tank to the sub tank by making the pressure in the sub tank negative while the drive valve arranged in the ink flow path connecting the main tank and the sub tank is opened. An ink jet recording apparatus is disclosed.

JP-A-2005-001286

  In Patent Document 1, when the power of the inkjet recording apparatus is cut off due to a power failure or the like while ink is being supplied from the main tank to the sub tank, the pressure in the sub tank remains negative and the ink flow path The state where the arranged drive valve is open continues. Accordingly, ink supply from the main tank to the sub tank continues to be executed. As a result, the ink may overflow from the sub tank.

  Accordingly, an object of the present invention is to stop the replenishment of ink from a main tank to a sub tank when the power is turned off in view of the above-described problems.

  The present invention relates to a recording head for discharging ink onto a recording medium, a sub tank for storing ink supplied to the recording head, a main tank for storing ink to be replenished to the sub tank, and the main tank. An ink flow path connecting the sub tank, a first valve capable of opening and closing the ink flow path, an air flow path communicating with an air layer in the sub tank and being open to the atmosphere, and opening and closing the air flow path An ink jet recording apparatus comprising: a second valve that is capable of generating a negative pressure in the sub tank; and a negative pressure generating unit that generates a negative pressure in the sub tank, wherein the negative pressure is generated in the sub tank by the negative pressure generating unit. An ink jet recording apparatus, wherein the second valve opens when the power of the apparatus is turned off while ink is being supplied from the main tank to the sub tank in the open state. It is.

  According to the present invention, when the power supply is cut off, the ink supply from the main tank to the sub tank can be stopped.

FIG. 3 is a diagram when the recording apparatus is in a standby state according to the first embodiment. FIG. 3 is a block diagram illustrating a control configuration of the recording apparatus in the first embodiment. FIG. 3 is a diagram when the recording apparatus is in a recording state in the first embodiment. It is a figure which shows the ink supply unit in 1st Embodiment. 6 is a flowchart of ink supply processing in the first embodiment. FIG. 3 is a diagram illustrating an ink supply unit when the power is turned off during ink supply in the first embodiment. It is a figure which shows an ink supply unit when the power supply is turned off during ink replenishment in a form without a solenoid valve. It is the schematic of the ink supply system in 2nd Embodiment. It is a figure which shows the ink supply unit in 3rd Embodiment. It is a flowchart of the sticking elimination process in 3rd Embodiment.

  Hereinafter, a liquid discharge head and a liquid discharge apparatus according to an embodiment of the present invention will be described with reference to the drawings. In the following embodiments, an ink jet recording head and an ink jet recording apparatus that discharge ink will be described with specific configurations, but the present invention is not limited to this. The liquid discharge head, the liquid discharge device, and the liquid supply method of the present invention are a combination of a printer, a copier, a facsimile having a communication system, a word processor having a printer unit, and various processing devices. It can be applied to a recording apparatus. For example, it can be used for applications such as biochip fabrication and electronic circuit printing. Further, the embodiments described below are specific examples of the present invention, and thus various technically preferable limitations are attached. However, the embodiments are not limited to those described below and other specific methods as long as they are in accordance with the idea of the present invention.

[First Embodiment]
<Internal configuration of recording device>
FIG. 1 is an internal configuration diagram of an ink jet recording apparatus 1 (hereinafter, recording apparatus 1). In the figure, the x direction indicates the horizontal direction, the y direction (perpendicular to the paper surface) indicates the direction in which the ejection openings are arranged in the recording head 8 described later, and the z direction indicates the vertical direction.

  The recording apparatus 1 is a multifunction machine including a printing unit 2 and a scanner unit 3, and can perform various processes relating to a recording operation and a reading operation individually or in conjunction with the printing unit 2 and the scanner unit 3. The scanner unit 3 includes an ADF (automatic document feeder) and an FBS (flatbed scanner), and reads a document automatically fed by the ADF and reads a document placed on a document table of the FBS by a user (scanning). )It can be performed. Although a multi-function machine having both the print unit 2 and the scanner unit 3 is shown here, a configuration without the scanner unit 3 may be used. FIG. 1 shows a state in which the recording apparatus 1 is in a standby state in which neither a recording operation nor a reading operation is performed.

  In the print unit 2, a first cassette 5 </ b> A and a second cassette 5 </ b> B for accommodating a recording medium (cut sheet) S are detachably installed on the bottom of the casing 4 in the vertical direction. A relatively small recording medium up to A4 size is accommodated in the first cassette 5A, and a relatively large recording medium up to A3 size is accommodated in the second cassette 5B. Near the first cassette 5A, a first feeding unit 6A for separating and feeding the stored recording media one by one is provided. Similarly, a second feeding unit 6B is provided in the vicinity of the second cassette 5B. When a recording operation is performed, the recording medium S is selectively fed from one of the cassettes.

  The conveyance roller 7, the discharge roller 12, the pinch roller 7a, the spur 7b, the guide 18, the inner guide 19, and the flapper 11 are conveyance mechanisms for guiding the recording medium S in a predetermined direction. The conveyance roller 7 is a driving roller that is arranged on the upstream side and the downstream side of the recording head 8 and is driven by a conveyance motor (not shown). The pinch roller 7 a is a driven roller that rotates while nipping the recording medium S together with the conveying roller 7. The discharge roller 12 is a drive roller that is disposed on the downstream side of the transport roller 7 and is driven by a transport motor (not shown). The spur 7 b sandwiches and transports the recording medium S together with the transport roller 7 and the discharge roller 12 disposed on the downstream side of the recording head 8.

  The guide 18 is provided in the conveyance path of the recording medium S and guides the recording medium S in a predetermined direction. The inner guide 19 has a side surface curved by a member extending in the y direction, and guides the recording medium S along the side surface. The flapper 11 is a member for switching the direction in which the recording medium S is conveyed during the double-side recording operation. The discharge tray 13 is a tray for stacking and holding the recording medium S that has completed the recording operation and is discharged by the discharge roller 12.

  The recording head 8 is a full-line type color inkjet recording head, and a plurality of ejection openings for ejecting ink according to the recording data are arranged along the y direction in FIG. 1 corresponding to the width of the recording medium S. . When the recording head 8 is in the standby position, the ejection port surface 8a of the recording head 8 is capped by a cap unit (also referred to as a cap mechanism) 10 as shown in FIG. When performing the recording operation, the orientation of the recording head 8 is changed by the print controller 202 described later so that the ejection port surface 8 a faces the platen 9. The platen 9 is constituted by a flat plate extending in the y direction, and supports the recording medium S on which the recording operation is performed by the recording head 8 from the back side. The movement of the recording head 8 from the standby position to the recording position will be described in detail later.

  The ink tank unit 14 stores the four colors of ink supplied to the recording head 8. Here, the four color inks indicate cyan (C), magenta (M), yellow (Y), and black (K) inks. The ink supply unit 15 is provided in the middle of the flow path connecting the ink tank unit 14 and the recording head 8, and adjusts the pressure and flow rate of the ink in the recording head 8 to an appropriate range. The recording apparatus 1 has a circulation type ink supply system, and the ink supply unit 15 adjusts the pressure of ink supplied to the recording head 8 and the flow rate of ink collected from the recording head 8 to an appropriate range.

  The maintenance unit 16 includes a cap unit 10 and a wiping unit 17 and operates them at a predetermined timing to perform a maintenance operation on the recording head 8.

<Regarding the control configuration of the recording apparatus>
FIG. 2 is a block diagram showing a control configuration in the recording apparatus 1. The recording apparatus 1 mainly includes a print engine unit 200 that controls the printing unit 2, a scanner engine unit 300 that controls the scanner unit 3, and a controller unit 100 that controls the entire recording apparatus 1. The print controller 202 controls various mechanisms of the print engine unit 200 in accordance with instructions from the main controller 101 of the controller unit 100. Various mechanisms of the scanner engine unit 300 are controlled by the main controller 101 of the controller unit 100. Details of the control configuration will be described below.

  In the controller unit 100, a main controller 101 constituted by a CPU controls the entire recording apparatus 1 according to a program and various parameters stored in the ROM 107 while using the RAM 106 as a work area. For example, when a print job is input from the host apparatus 400 via the host I / F 102 or the wireless I / F 103, predetermined image processing is performed on the image data received by the image processing unit 108 in accordance with an instruction from the main controller 101. Apply. Then, the main controller 101 transmits the image data subjected to image processing to the print engine unit 200 via the print engine I / F 105.

  The recording device 1 may acquire image data from the host device 400 via wireless communication or wired communication, or may acquire image data from an external storage device (such as a USB memory) connected to the recording device 1. Also good. A communication method used for wireless communication or wired communication is not limited. For example, Wi-Fi (Wireless Fidelity) (registered trademark) or Bluetooth (registered trademark) is applicable as a communication method used for wireless communication. As a communication method used for wired communication, USB (Universal Serial Bus) or the like can be applied. For example, when a reading command is input from the host device 400, the main controller 101 transmits this command to the scanner engine unit 300 via the scanner engine I / F 109.

  The operation panel 104 is a mechanism for the user to input and output to the recording apparatus 1. The user can instruct operations such as copying and scanning, set a print mode, and recognize information of the recording apparatus 1 via the operation panel 104.

  In the print engine unit 200, a print controller 202 constituted by a CPU controls various mechanisms provided in the printing unit 2 while using the RAM 204 as a work area according to programs and various parameters stored in the ROM 203. When various commands and image data are received via the controller I / F 201, the print controller 202 temporarily stores them in the RAM 204. The print controller 202 causes the image processing controller 205 to convert the stored image data into recording data so that the recording head 8 can be used for the recording operation. When the recording data is generated, the print controller 202 causes the recording head 8 to execute a recording operation based on the recording data via the head I / F 206. At this time, the print controller 202 drives the feeding units 6A and 6B, the conveyance roller 7, the discharge roller 12, and the flapper 11 shown in FIG. In accordance with an instruction from the print controller 202, the recording operation by the recording head 8 is executed in conjunction with the conveying operation of the recording medium S, and printing processing is performed.

  The head carriage control unit 208 changes the orientation and position of the recording head 8 in accordance with an operation state such as a maintenance state or a recording state of the recording apparatus 1. The ink supply control unit 209 controls the ink supply unit 15 so that the pressure of the ink supplied to the recording head 8 falls within an appropriate range. The maintenance control unit 210 controls the operation of the cleaning mechanism such as the cap unit 10 and the wiping unit 17 in the maintenance unit 16 when performing a maintenance operation on the recording head 8.

  In the scanner engine unit 300, the main controller 101 controls hardware resources of the scanner controller 302 while using the RAM 106 as a work area according to programs and various parameters stored in the ROM 107. Thereby, various mechanisms provided in the scanner unit 3 are controlled. For example, when the main controller 101 controls hardware resources in the scanner controller 302 via the controller I / F 301, a document loaded on the ADF by the user is conveyed via the conveyance control unit 304 and is read by the sensor 305. . Then, the scanner controller 302 stores the read image data in the RAM 303. Note that the print controller 202 can cause the recording head 8 to execute a recording operation based on the image data read by the scanner controller 302 by converting the image data acquired as described above into recording data. .

<Operation of the recording apparatus in the recording state>
FIG. 3 shows the recording apparatus 1 in the recording state. Compared with the standby state shown in FIG. 1, the cap unit 10 is separated from the ejection port surface 8 a of the recording head 8, and the ejection port surface 8 a faces the platen 9. The plane of the platen 9 is inclined by about 45 degrees with respect to the horizontal direction, and the discharge port surface 8a of the recording head 8 at the recording position is also about 45 with respect to the horizontal direction so that the distance from the platen 9 is maintained constant. Tilted.

  When the recording head 8 is moved from the standby position shown in FIG. 1 to the recording position shown in FIG. 3, the print controller 202 uses the maintenance control unit 210 to lower the cap unit 10 to the retracted position shown in FIG. Thereby, the discharge port surface 8a of the recording head 8 is separated from the cap member 10a. Thereafter, the print controller 202 rotates the recording head 8 by 45 degrees while adjusting the vertical height of the recording head 8 using the head carriage control unit 208, so that the ejection port surface 8 a faces the platen 9. When the recording operation is completed and the recording head 8 moves from the recording position to the standby position, the reverse process is performed by the print controller 202.

  Next, the conveyance path of the recording medium S in the print unit 2 will be described. When a recording command is input, the print controller 202 first moves the recording head 8 to the recording position shown in FIG. 3 using the maintenance control unit 210 and the head carriage control unit 208. Thereafter, the print controller 202 uses the transport control unit 207 to drive either the first feeding unit 6A or the second feeding unit 6B according to the recording command, and feeds the recording medium S.

<Ink supply unit>
FIG. 4 is a diagram including an ink supply unit 15 employed in the inkjet recording apparatus 1 of the present embodiment. The flow path configuration of the ink circulation system of the present embodiment will be described with reference to FIG. The ink supply unit 15 is configured to supply ink from the ink tank unit 14 to the recording head 8. Here, the configuration for one color ink is shown, but in reality such a configuration is used for each ink color (for example, cyan (C), magenta (M), yellow (Y), black (Bk)). For each color). The ink supply unit 15 is basically controlled by the ink supply control unit 209 shown in FIG. Hereinafter, each configuration of the unit will be described.

  Ink mainly circulates between the sub tank 151 and the recording head 8 (head unit in FIG. 4). In the head unit 8, an ink ejection operation is performed based on the image data, and the ink that has not been ejected is again collected in the sub tank 151.

  The sub tank 151 that stores a predetermined amount of ink is connected to a supply flow path C <b> 2 for supplying ink to the head unit 8 and a recovery flow path C <b> 4 for recovering ink from the head unit 8. That is, a circulation path through which ink circulates is configured by the sub tank 151, the supply flow path C2, the head unit 8, and the recovery flow path C4.

  The sub tank 151 is provided with a liquid level detecting means 151a composed of a plurality of pins, and the ink supply control unit 209 detects the presence or absence of a conduction current between the plurality of pins, so that the height of the ink liquid level, The remaining amount of ink in the sub tank 151 can be grasped. The decompression pump P0 is a negative pressure generation source for decompressing the inside of the sub tank 151. The solenoid valve (solenoid valve) V6 is an electrically driven valve that can be opened and closed electrically. The solenoid valve (electromagnetic valve) V6 is connected to the upper side of the sub tank 151 and communicates with a flow path C6 that communicates with an internal air layer (a portion not containing ink). It is a valve for switching whether to communicate with the atmosphere. The channel C6 is an air channel through which air flows. The solenoid valve V6 is closed when the recording apparatus 1 is turned on (CLOSE state), and is opened when the power is turned off due to a user operation or a power failure (OPEN state). The pressure reducing valve V7 is provided in the middle of the flow path C6, and is a valve for switching opening and closing of the flow path C6. The atmosphere release valve V0 is a valve for switching whether or not to communicate the interior of the sub tank 151 with the atmosphere.

  The main tank 141 is a tank that stores the ink supplied to the sub tank 151. The main tank 141 is composed of a flexible member, and the sub tank 151 is filled with ink by changing the volume of the flexible member. The main tank 141 is detachable from the recording apparatus main body. A tank supply valve V1 for switching the connection between the sub tank 151 and the main tank 141 is disposed in the middle of the tank connection channel C1 that connects the sub tank 151 and the main tank 141. The tank supply valve V1 is an electrically driven valve that can be electrically opened and closed.

  With the above configuration, when the ink supply control unit 209 detects that the ink in the sub tank 151 is less than a predetermined amount by the liquid level detection unit 151a, the air release valve V0, the supply valve V2, the recovery valve V4, And the head exchange valve V5 is closed. Further, the ink supply control unit 209 opens the tank supply valve V1 and the pressure reducing valve V7. In this state, the ink supply control unit 209 operates the decompression pump P0. Then, the inside of the sub tank 151 becomes negative pressure, and ink is supplied from the main tank 141 to the sub tank 151. When the liquid level detection means 151a detects that the amount of ink in the sub tank 151 exceeds a predetermined amount, the ink supply control unit 209 closes the tank supply valve V1 and stops the decompression pump P0.

  The supply flow path C2 is a flow path for supplying ink from the sub tank 151 to the head unit 8, and a supply pump P1 and a supply valve V2 are arranged in the middle thereof. During the recording operation, the ink can be circulated in the circulation path while supplying the ink to the head unit 8 by driving the supply pump P1 with the supply valve V2 opened. The amount of ink ejected per unit time by the head unit 8 varies depending on the image data. The flow rate of the supply pump P1 is determined so as to be able to cope with the case where the head unit 8 performs an ejection operation that maximizes the ink ejection amount per unit time.

  The relief flow path C3 is a flow path that connects the upstream side and the downstream side of the supply pump P1 on the upstream side of the supply valve V2. A relief valve V3, which is a differential pressure valve, is arranged in the middle of the relief flow path C3. When the ink supply amount per unit time from the supply pump P1 is larger than the total value of the discharge amount per unit time of the head unit 8 and the flow rate per unit time (amount of ink drawn) in the recovery pump P2, the relief valve V3 is released according to the pressure acting on itself. As a result, a circulating flow path constituted by a part of the supply flow path C2 and the relief flow path C3 is formed. By providing the relief channel C3, the amount of ink supplied to the head unit 8 is adjusted according to the amount of ink discharged from the head unit 8, and the flow pressure in the circulation path can be stabilized regardless of image data. it can.

  The recovery channel C4 is a channel for recovering ink from the head unit 8 to the sub tank 151, and a recovery pump P2 and a recovery valve V4 are arranged in the middle thereof. The recovery pump P2 sucks ink from the head unit 8 as a negative pressure generation source when the ink is circulated in the circulation path. By driving the recovery pump P2, an appropriate pressure difference is generated between the IN channel 80b and the OUT channel 80c in the head unit 8, and ink can be circulated between the IN channel 80b and the OUT channel 80c. . The flow path configuration in the head unit 8 will be described in detail later.

  The recovery valve V4 is a valve for preventing backflow when the recording operation is not performed, that is, when ink is not circulated in the circulation path. In the circulation path of the present embodiment, the sub tank 151 is disposed above the head unit 8 in the vertical direction (see FIG. 1). For this reason, when the supply pump P <b> 1 and the recovery pump P <b> 2 are not driven, the ink may flow backward from the sub tank 151 to the head unit 8 due to a water head difference between the sub tank 151 and the head unit 8. In order to prevent such backflow, a recovery valve V4 is provided in the recovery flow path C4 in this embodiment.

  Similarly, the supply valve V2 functions as a valve for preventing the supply of ink from the sub tank 151 to the head unit 8 when the recording operation is not performed, that is, when the ink is not circulated in the circulation path.

  The head exchange flow path C5 is a flow path that connects the supply flow path C2 and the air layer of the sub tank 151, and a head exchange valve V5 is disposed in the middle thereof. One end of the head exchange channel C5 is connected to the upstream side of the head unit 8 in the supply channel C2, and the other end is connected to the upper side of the sub tank 151 to communicate with the internal air layer. The head exchange channel C5 is used when collecting ink from the head unit 8 in use, such as when the head unit 8 is exchanged or when the recording apparatus 1 is transported. The head replacement valve V5 is controlled by the ink supply control unit 209 so as to be closed except when the recording apparatus 1 is initially filled with ink and when the ink is recovered from the head unit 8. Further, the supply valve V2 described above is provided in the supply flow path C2 between the connection portion with the head replacement flow path C5 and the connection portion with the relief flow path C3.

  Next, the flow path configuration in the head unit 8 will be described. The ink supplied to the head unit 8 from the supply channel C <b> 2 passes through the filter 83 and is then supplied to the first negative pressure control unit 81 and the second negative pressure control unit 82. In the first negative pressure control unit 81, the control pressure is set to a weak negative pressure. In the second negative pressure control unit 82, the control pressure is set to a strong negative pressure. The pressures in the first negative pressure control unit 81 and the second negative pressure control unit 82 are generated in an appropriate range by driving the recovery pump P2.

  In the ink discharge unit 80, a plurality of recording element substrates 80a on which a plurality of discharge ports are arranged are arranged, and a long discharge port array is formed. A common supply flow path 80b (IN flow path) for guiding ink supplied from the first negative pressure control unit 81 and a common recovery flow path for guiding ink supplied from the second negative pressure control unit 82 80c (OUT flow path) also extends in the arrangement direction of the recording element substrates 80a. Further, individual recording element substrates 80a are formed with individual supply channels connected to the common supply channel 80b and individual recovery channels connected to the common recovery channel 80c. For this reason, in each recording element substrate 80a, there is an ink flow that flows in from the common supply channel 80b having a relatively low negative pressure and flows out to the common recovery channel 80c having a relatively low negative pressure. Generated. A pressure chamber that is connected to each ejection port and is filled with ink is provided in the path of the individual supply channel and the individual recovery channel, so that the ink flows even in the ejection port and pressure chamber that are not recording. Arise. When a discharge operation is performed on the recording element substrate 80a, a part of the ink moving from the common supply channel 80b to the common recovery channel 80c is discharged by being discharged from the discharge port, but the ink that has not been discharged is discharged. It moves to the recovery channel C4 via the common recovery channel 80c.

  With the above configuration, when performing a recording operation, the ink supply control unit 209 closes the tank supply valve V1, the head replacement valve V5, and the pressure reducing valve V7, and opens the atmosphere release valve V0, the supply valve V2, and the recovery valve V4. And the supply pump P1 and the recovery pump P2 are driven. Thereby, a circulation path of the sub tank 151 → the supply flow path C2 → the head unit 8 → the recovery flow path C4 → the sub tank 151 is established. When the ink supply amount per unit time from the supply pump P1 is larger than the total value of the discharge amount per unit time of the head unit 8 and the flow rate per unit time in the recovery pump P2, the supply channel C2 to the relief channel Ink flows into C3. Thereby, the flow rate of the ink flowing into the head unit 8 from the supply channel C2 is adjusted.

  When the recording operation is not performed, the ink supply control unit 209 stops the supply pump P1 and the recovery pump P2, and closes the atmosphere release valve V0, the supply valve V2, and the recovery valve V4. Thereby, the flow of ink in the head unit 8 stops, and the backflow due to the water head difference between the sub tank 151 and the head unit 8 is also suppressed. Further, by closing the atmosphere release valve V0, ink leakage from the sub tank 151 and ink evaporation are suppressed.

  When collecting ink from the head unit 8, the ink supply control unit 209 closes the atmosphere release valve V0, the tank supply valve V1, the supply valve V2, the recovery valve V4, and the solenoid valve V6, the head replacement valve V5, and the pressure reducing valve. V7 is opened and the decompression pump P0 is driven. Thereby, the inside of the sub tank 151 is in a negative pressure state, and the ink in the head unit 8 is collected into the sub tank 151 via the head replacement flow path C5. Thus, the head replacement valve V5 is closed during normal recording operation or standby, and is opened when ink is collected from the head unit 8. However, the head exchange valve V5 is also opened when the head exchange channel C5 is filled with ink in the initial filling of the head unit 8.

<Ink replenishment process with solenoid valve opening when power is turned off>
Hereinafter, ink replenishment processing that involves opening the solenoid valve when the power is turned off in the present embodiment will be described with reference to FIG. The ink replenishment process described below starts when ink circulation is stopped in the circulation path described above. Specifically, the state where the circulation of ink is stopped is that the decompression pump P0, the supply pump P1, and the recovery pump P2 are stopped, and the air release valve V0, the tank supply valve V1, the supply valve V2, the recovery valve V4, The head exchange valve V5, the solenoid valve V6, and the pressure reducing valve V7 are closed.

  In step S501, the print controller 202 controls the ink supply control unit 209 to open the pressure reducing valve V7.

  In step S502, the print controller 202 controls the ink supply control unit 209 to open the tank supply valve V1.

  In step S503, the print controller 202 controls the ink supply control unit 209 to drive the decompression pump P0. In this step, since the pressure in the sub tank 151 becomes negative, ink is drawn from the main tank 141 to the sub tank 151.

  In step S504, when the power of the recording apparatus 1 is cut off due to an on / off operation or a power failure by the user (the recording apparatus 1 is in a power off state), the process proceeds to step S505, but the power of the recording apparatus 1 is not cut off. The process proceeds to step S506.

  First, a case where the power of the recording apparatus 1 is turned off (YES in step S504) will be described. In this case, in step S505, the solenoid valve V6 is opened. By this step, the circulation system of the recording apparatus 1 transitions to the state shown in FIG. As shown in the figure, as a result of the solenoid valve V6 being opened and the sub tank 151 being opened to the atmosphere, the negative pressure in the sub tank 151 is eliminated. Accordingly, even if the tank supply valve V1 is continuously open, the ink flow from the main tank 141 to the sub tank 151 (ink flow) can be stopped, and the ink supply from the main tank 141 to the sub tank 151 can be stopped. . Therefore, it is possible to prevent the ink from overflowing from the sub tank 151. After this step, the series of processing ends (halfway of ink supply processing).

  Next, a case where the recording apparatus 1 is not turned off (NO in step S504) will be described. In this case, when the print controller 202 detects that the sub tank 151 is filled using the liquid level detection means 151a, in step S506, the print controller 202 controls the ink supply control unit 209 to stop the decompression pump P0.

  In step S507, the print controller 202 controls the ink supply control unit 209 to open the atmosphere release valve V0. By this step, the inside of the sub tank 151 is opened to the atmosphere.

  In step S508, the print controller 202 controls the ink supply control unit 209 to close the atmosphere release valve V0. The ink flow from the main tank 141 to the sub tank 151 is stopped by executing the processing of step S506 to step S508. The above is the content of the ink supply process in the present embodiment.

<About the effect of this embodiment>
In the present embodiment, when the power of the recording apparatus 1 is cut off while ink is supplied from the main tank 141 to the sub tank 151, the solenoid valve disposed in the flow path C6 that communicates the outside air with the air layer in the sub tank 151. V6 changes from the closed state to the open state. As a result, the pressure in the sub tank 151 is not negative but equal to atmospheric pressure. Accordingly, ink is not drawn from the main tank 141 to the sub tank 151 thereafter. Therefore, it is possible to prevent the ink from overflowing from the sub tank 151.

  For comparison, an ink supply unit without the solenoid valve V6 is shown in FIG. In the ink supply unit 15 shown in FIG. 7, when the power of the recording apparatus is turned off while ink is supplied from the main tank 141 to the sub tank 151, the pressure in the sub tank 151 continues to be negative. Therefore, even after the recording apparatus is turned off, the ink is continuously drawn from the main tank 141 to the sub tank 151, and as a result, the ink may overflow from the sub tank 151.

[Second Embodiment]
In the first embodiment, a configuration related to ink of one color is shown (see FIG. 4). The present embodiment relates to a configuration of an ink supply unit for a plurality of colors of ink. In the following, differences from the above-described embodiment will be mainly described, and description of the same contents as in the above-described embodiment will be omitted as appropriate.

<Ink supply unit>
The ink supply unit of the recording apparatus 1 in the present embodiment is configured with an ink supply unit for each color. Specifically, the ink supply unit for each color includes a C ink supply unit, an M ink supply unit, a Y ink supply unit, and a Bk ink supply unit.

  Each of these ink supply units has the same configuration as the ink supply unit 15 shown in FIG. That is, each color ink supply unit includes a main tank, a sub tank, a tank supply valve for switching the opening and closing of the flow path between the main tank and the sub tank, and a pressure reducing valve for switching the opening and closing of the flow path between the pressure reducing pump and the sub tank. have. However, the decompression pump and the solenoid valve are not provided for each color, and one color is shared by all colors.

FIG. 8 is a schematic diagram of the ink supply unit in the above-described embodiment, and shows a form in which Bk ink is supplied from the main tank 141 _Bk to the sub tank 151 _Bk . For example, when focusing on Bk, ink supply unit Bk, the main tank _{141 Bk,} the sub tank _{151 Bk,} passage _{C1 Bk} connecting the main tank _{141 Bk} and the sub-tank _{151 Bk,} a tank feed valve disposed in the flow path _{C1 Bk} V1 _Bk and a pressure reducing valve V7 _Bk are provided. The other color ink supply units have the same configuration as the Bk ink supply unit. The air flow paths of the ink supply units of the respective colors are integrated into one flow path C6, and a solenoid valve V6 and a pressure reducing pump P0 are arranged in the integrated flow path C6.

  Under such a configuration, as in the first embodiment, when the power supply of the recording apparatus 1 is turned off while ink is being supplied to the sub tank, the flow path C6 communicates the outside air with the air layer in the sub tank. Solenoid valve V6 arranged at is opened. Then, the ink flow from the main tank to the sub tank is stopped, and the ink supply from the main tank to the sub tank is stopped. Therefore, it is possible to prevent the ink from overflowing from the sub tank.

<Effects and Modifications of the Present Embodiment>
According to this embodiment, in the configuration in which the recording apparatus includes an ink supply unit for each color, it is sufficient to arrange one decompression pump and solenoid valve in the flow path upstream of the decompression valve for each color. There is no need to do it. Therefore, the number of these parts can be reduced.

  In the present embodiment, the recording apparatus 1 has been described with respect to the four color inks, that is, the ink supply units corresponding to the respective colors of C, M, Y, and Bk. However, the number of ink colors to be used is not limited to four. . The present embodiment can be applied to a recording apparatus having an ink supply unit corresponding to each color of a plurality of colors of ink.

[Third Embodiment]
<Ink supply unit>
FIG. 9 is a diagram including the ink supply unit 90 in the present embodiment. As shown in the figure, the ink supply unit 90 in the present embodiment has substantially the same configuration as the ink supply unit 15 in the first embodiment, but a check valve is provided in the flow path between the solenoid valve V6 and the pressure reducing valve V7. The difference is that V8 is arranged. In addition, the solenoid valve V6 is closed when the power is turned on, while being opened when the power is turned off, as in the first embodiment. In this embodiment, the ink supply control unit is at an arbitrary timing when the recording apparatus 1 is turned on. 209 can control the opening and closing of the solenoid valve V6.

The check valve V8 is a valve provided to limit the direction of air flow in the flow path to one direction, and is configured by a seal member or the like. The check valve V8 opens and closes according to the relationship between the downstream pressure and the upstream pressure. Specifically, (the pressure of the solenoid valve side and _{P V6)} pressure solenoid valve V6 side relationship between the sub-tank 151 side pressure (the pressure of the sub tank side to _{P 151)} is _P V6 _{-P 151} ≧ When C is satisfied, it is in an open state. That is, the check valve V8 restricts the direction in which air is supplied toward the sub tank 151. On the other hand, when P _V6 −P ₁₅₁ <C is satisfied, the closed state is established. Here, the predetermined value C is a pressure difference threshold and is a value unique to the check valve V8.

  The reason why the check valve V8 is arranged is as follows. In the first embodiment, when the power of the recording apparatus 1 is cut off while ink is supplied to the sub tank 151, the solenoid valve V6 disposed in the flow path C6 that communicates the outside air with the air layer in the sub tank 151 is provided. From the closed state to the open state. As a result, the pressure in the sub tank 151 is not negative but equal to atmospheric pressure. Therefore, thereafter, ink is not drawn from the main tank 141 to the sub tank 151 due to the negative pressure. However, in the configuration in which the main tank 141 is positioned above the sub tank 151 in the gravity direction, the ink flow from the main tank 141 to the sub tank 151 does not stop due to the water head difference, and there is a possibility that the ink overflows from the sub tank 151. In order to prevent this, a check valve V8 is provided in the present embodiment. As a result, after the power supply of the recording apparatus 1 is turned off while ink is being supplied to the sub tank 151, when the pressure in the sub tank 151 becomes equal to the atmospheric pressure, the check valve V8 is further closed so that the sub tank 151 is closed. Is sealed. Therefore, the ink flow from the main tank 141 to the sub tank 151 can be stopped reliably.

<About sticking cancellation processing>
The check valve V8 has a configuration that opens only when a differential pressure is generated. Therefore, if the check valve V8 is kept closed for a long time, the seal member inside the check valve V8 sticks to the wall surface, and it is assumed that the check valve V8 does not open even if a differential pressure occurs. . That is, it is assumed that the check valve V8 does not open even when the seal member inside the check valve V8 adheres to the wall surface and P _V6 −P ₁₅₁ ≧ C is satisfied. In order to prevent such sticking of the sealing member, a process of peeling the sealing member attached to the wall surface is performed before the ink supply operation is performed. Such processing is called sticking elimination processing. By the sticking elimination processing, sticking of the seal member inside the check valve V8 is eliminated, and the check valve V8 can be opened and closed.

  Hereinafter, the sticking elimination processing in the present embodiment will be described with reference to FIG. The sticking elimination process is executed after the recording device 1 is left in a place where the temperature change is large and the check valve V8 is not operated for a long time. Specifically, when the recording device arrives at the purchaser and performs the initial setting, or when the user requests repair of the recording device and the repaired recording device arrives at the user's hand, the initial setting is performed again. The timing to perform is assumed. In the sticking elimination process, the decompression pump P0, the supply pump P1, and the recovery pump P2 are stopped, and the air release valve V0, the tank supply valve V1, the supply valve V2, the recovery valve V4, the head replacement valve V5, and the solenoid valve V6. And with the pressure reducing valve V7 closed.

  In step S1001, the print controller 202 controls the ink supply control unit 209 to open the pressure reducing valve V7.

  In step S1002, the print controller 202 controls the ink supply control unit 209 to drive the decompression pump P0.

  In step S1003, the print controller 202 controls the ink supply control unit 209 to stop the decompression pump P0. After this step, the pressure in the sub tank 151 is negative.

In step S1004, the print controller 202 controls the ink supply control unit 209 to open the solenoid valve V6. By this step, the relationship between the pressure _{P 151} of the pressure _{P V6} and the sub-tank 151 side of the solenoid valve V6 side is to meet the _P V6 _{-P 151} ≧ D (where D >> C). Due to the force corresponding to the pressure difference, the seal member attached to the wall surface inside the check valve V8 is peeled off, and the check valve V8 is opened.

  In step S1005, the print controller 202 controls the ink supply control unit 209 to close the solenoid valve V6.

  In step S1006, the print controller 202 controls the ink supply control unit 209 to open the atmosphere release valve V0. By this step, the pressure in the sub tank 151 becomes equal to the atmospheric pressure.

  In step S1007, the print controller 202 controls the ink supply control unit 209 to close the atmosphere release valve V0. The above is the content of the sticking elimination process in the present embodiment.

<About the effect of this embodiment>
In the present embodiment, when the power of the recording apparatus 1 is turned off while ink is supplied to the sub tank 151, the solenoid valve V6 is opened, the pressure in the sub tank 151 becomes equal to the atmospheric pressure, and the check valve V8 is By closing, the sub tank 151 is sealed. Thereby, even if the main tank 141 is positioned above the sub tank 151 in the gravity direction, the ink flow from the main tank 141 to the sub tank 151 can be stopped.

[Other Embodiments]
The present invention supplies a program that realizes one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and one or more processors in a computer of the system or apparatus read and execute the program This process can be realized. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

1 Recording device 8 Recording head (head unit)
141 Main tank 151 Sub tank C1 Tank connection flow path C6 Flow path V1 Tank supply valve V6 Solenoid valve P0 Pressure reducing pump

Claims (11)

A recording head for recording on a recording medium by discharging ink;
A sub tank for storing ink to be supplied to the recording head;
A main tank for storing ink to be supplied to the sub tank;
An ink flow path connecting the main tank and the sub tank;
A first valve capable of opening and closing the ink flow path;
An air flow path communicating with the air layer in the sub-tank and opened to the atmosphere;
A second valve capable of opening and closing the air flow path;
An ink jet recording apparatus having a negative pressure generating means for generating a negative pressure in the sub-tank,
When the power supply of the apparatus is cut off while supplying ink from the main tank to the sub tank in a state where the negative pressure is generated in the sub tank by the negative pressure generating means and the first valve is opened, 2. An ink jet recording apparatus, wherein two valves are opened.   2. The ink jet recording apparatus according to claim 1, wherein the second valve is a solenoid valve that closes when the apparatus is turned on and opens when the apparatus is turned off.   The inkjet recording apparatus according to claim 1, wherein the first valve is an electrically driven valve. The main tank, the sub tank, the ink flow path, the first valve, and the air flow path are provided for each color of ink,
The air flow path for each color is integrated, and the second valve and the negative pressure generating means are arranged in the integrated air flow path. The ink jet recording apparatus described. A third valve disposed in the air flow path;
5. The third valve is disposed between the second valve and the sub-tank and at a position not between the negative pressure generating unit and the sub-tank. The ink jet recording apparatus according to any one of the above.   6. The ink jet recording apparatus according to claim 5, wherein the third valve is a check valve for restricting a direction in which air is supplied to the sub tank in the air flow path.   The said 2nd valve opens when the said power supply is cut | disconnected while supplying ink from the said main tank to the said sub tank, The said 3rd valve is closed after that, The 6th characterized by the above-mentioned. 2. An ink jet recording apparatus according to 1. The third valve is an ink jet recording apparatus according to claim 7, characterized in that open when the pressure P ₁₅₁ of the pressure P _V6 and the sub-tank side of the second valve side satisfies the following expression.

  9. The ink jet recording apparatus according to claim 8, further comprising control means for controlling opening and closing of the first valve, the second valve, and the third valve. A method for controlling an ink jet recording apparatus according to claim 9,
The negative pressure generating means creates a negative pressure in the sub-tank;
And a step of opening the second valve when the control means satisfies the following expression.

  A program for causing a computer to execute the method according to claim 10.

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