JP2014024229A - Liquid circulation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid circulation device capable of circulating a liquid with a simple structure without passing the liquid through a pump.SOLUTION: A first accumulation part 4 may accumulate a white ink therein. A second accumulation part 11, in which the white ink is accumulated, is attached to an attachment part 10. A pump 7 discharges air in a sealed space 5 of the first accumulation part 4 to the exterior. A first passage 14 and a second passage 17 respectively connect with the first accumulation part 4 and the attachment part 10. A first valve 21 opens and closes the second passage 17. A second valve 22 opens and closes a communication passage 8 which allows a gas in the first accumulation part 4 to communicate with the atmosphere. A liquid circulation device 3 discharges a gas in the sealed space 5 to the exterior with the second passage 17 and the communication passage 8 closed when the white ink is sent from the attachment part 10 side to the first accumulation part 4 side. The liquid circulation device 3 opens the second passage 17 and the communication passage 8 when the white ink is sent from the first accumulation part 4 side to the attachment part 10 side.

Description

  The present invention relates to a liquid circulation device for circulating a liquid such as ink.

  Conventionally, an ink circulation device that circulates a liquid such as ink is known. By circulating the liquid, for example, sedimentation of a substance (for example, ink pigment) contained in the liquid can be suppressed, bubbles in the liquid can be removed, and the like. In the liquid ejection device disclosed in Patent Document 1, ink supplied from a main tank is circulated between a supply pump, a head, and a sub tank.

JP 2010-76301 A

  In the liquid ejection device disclosed in Patent Document 1, the liquid is circulated by a pump that delivers the liquid. For example, the pump may have a sliding portion that slides with respect to a tube that is a liquid flow path, and the liquid in the tube may be pushed out by crushing the tube with the sliding portion. In this pump, heat is generated by friction between the sliding portion and the tube. When liquid is passed through the pump, the liquid may be denatured by heat generated by the pump. Depending on the components of the liquid, the liquid may cause deterioration in the pump components. In the prior art, it was difficult to circulate the liquid with a simple configuration without passing the liquid through the pump.

  An object of this invention is to provide the liquid circulation apparatus which can circulate a liquid by a simple structure, without passing a liquid through a pump.

  The liquid circulation device according to the first aspect of the present invention includes a first storage section that can store a liquid and that can form a sealed space therein, a first storage section that stores the liquid and that communicates with the atmosphere inside. A mounting part for mounting two storage parts, a pump connected to the first storage part, for discharging the gas in the sealed space to the outside of the first storage part, and connected to the first storage part and the mounting part Connected to the first flow path, the first storage part and the mounting part, and one end connected to the first storage part is higher than the other end connected to the mounting part. A second flow path disposed; first opening / closing means for opening / closing the second flow path; a communication path for communicating the sealed space of the first storage section with the atmosphere; and a first for opening / closing the communication path. Two opening / closing means, driving of the pump, opening / closing of the first opening / closing means, and opening of the second opening / closing means. Control means for controlling, when the liquid is sent from the mounting portion side to the first storage portion side, the control means closes the second flow path by the first opening and closing means, and In a state where the communication path is closed by the second opening / closing means, the pump is driven to discharge the gas in the sealed space in the first storage part to the outside, and from the first storage part side to the mounting part side When the liquid is sent, the second flow path is opened by the first opening / closing means, and the communication path is opened by the second opening / closing means.

  In the liquid circulation device according to the first aspect of the present invention, the gas in the first reservoir is discharged outside from the second reservoir through the first channel while the second channel and the communication path are closed. Send liquid to one reservoir. By opening the second channel and the communication channel, the liquid is sent from the first reservoir to the second reservoir through the second channel. Therefore, the liquid circulation device can circulate the liquid without passing the liquid through the pump only by controlling the pump, the first opening / closing means, and the second opening / closing means.

  The liquid circulation device includes: a discharge section having a discharge port for discharging the liquid; a third flow path branched from the first flow path and connected to the discharge section; and the first flow path according to control by the control means And a third opening / closing means for opening and closing the circulation channel, which is a portion extending from the branch point with the third channel to the first reservoir, and for opening and closing the third channel. . The discharge port of the discharge unit may be arranged at a position higher than an end connected to the mounting unit in the first flow path. The control means, when sending the liquid from the mounting part side to the first storage part side, opens the circulation channel by the third opening / closing unit and closes the third channel. When the pump is driven to discharge the gas in the sealed space in the first reservoir to the outside, and the liquid is discharged from the discharge unit, the circulation channel is closed by the third opening / closing means. And the third channel may be opened. In this case, when the liquid is circulated from the second storage unit to the first storage unit, the liquid in the discharge unit is not affected. Therefore, the liquid circulation apparatus can suppress problems such as breakage of the meniscus formed in the discharge unit. Further, after the circulation channel is opened, gas is sucked by the pump. Therefore, the liquid circulation device can suppress the occurrence of problems due to a rapid pressure change, compared to the case where the circulation channel is opened after the pressure of the gas in the sealed space is reduced. For example, generation of bubbles in the liquid, deformation / deterioration of parts, and the like can be suppressed.

  The first reservoir may have an inclined surface that is inclined toward the bottom. The first reservoir side end of the second flow path may be connected to the inclined surface or the bottom. Compared with the case where the inclined surface is not provided, the height of the liquid surface of the liquid stored in the first storage portion is increased. Therefore, the liquid circulation device can smoothly send the liquid in the first storage part to the second storage part.

  The liquid circulation device according to the second aspect of the present invention includes a first storage section that can store a liquid and that can form a sealed space therein, a first storage section that stores the liquid and that communicates with the atmosphere inside. A mounting portion for mounting two storage portions; a pump connected to the first storage portion for discharging gas in the sealed space to the outside; and supplying gas to the sealed space; A first flow path and a second flow path connected to the storage section and the mounting section; a fourth opening / closing means for opening and closing the second flow path; a discharge section having a discharge port for discharging the liquid; A third flow path branched from one flow path and connected to the discharge section, and a circulation flow path that is a portion extending from the branch point of the first flow path to the first storage section from the branch point of the third flow path And a fifth opening / closing means for opening and closing the third flow path, and disposed in the circulation flow path, A sixth opening / closing mechanism that permits movement of fluid from the mounting portion side to the first storage portion side through the annular flow path and prohibits movement of fluid from the first storage portion side to the mounting portion side And a control means for controlling the driving of the pump, the opening and closing of the fourth opening and closing means, and the opening and closing of the fifth opening and closing means, and the discharge port of the discharge portion is mounted in the first flow path The control means is arranged at a position higher than the end connected to the part, and when the liquid is sent from the mounting part side to the first storage part side, the circulation channel is provided by the fifth opening / closing means. And closing the third flow path, driving the pump, and closing the second flow path by the fourth opening and closing means, the gas in the sealed space in the first storage portion The liquid is discharged to the outside, and the liquid is transferred from the first storage portion side to the mounting portion side. When the pump is driven, gas is supplied to the sealed space in the first storage section in a state where the second flow path is opened by the fourth opening / closing means, and the liquid is supplied from the discharge section. In the case of discharging, the fifth channel is closed by the fifth opening / closing means to open the third channel.

  In the liquid circulation device according to the second aspect of the present invention, the second flow path and the third flow path are closed and the circulation flow path is opened, and then the gas in the first storage section is discharged to the outside. Liquid is sent from the second reservoir to the first reservoir through the path. Therefore, it is possible to send the liquid from the second reservoir to the first reservoir while suppressing the generation of bubbles in the liquid due to a sudden pressure change. It is difficult for the liquid in the discharge part to be affected. The sixth opening / closing means prohibits the fluid from moving through the circulation channel from the first storage section side to the second storage section side. Therefore, the liquid circulation device can send the liquid from the first reservoir to the second reservoir only by supplying the gas to the first reservoir after opening the second flow path. The influence of a sudden pressure change is also suppressed. Therefore, the liquid circulation device can easily circulate the liquid without passing the liquid through the pump.

  2nd aspect WHEREIN: The said pump discharges | emits the gas of the said enclosed space in the said 1st storage part outside by rotating in a 1st direction, And 2nd direction opposite to said 1st direction A pump gear for supplying gas to the sealed space in the first storage part by rotating in the direction may be provided. The fourth opening / closing means meshes with the pump gear, and the pump gear rotates in the first direction to press and close the second flow path, so that the pump gear rotates in the second direction. The gear which opens said 2nd flow path may be sufficient. In this case, the liquid circulation device can switch between closing and opening the second flow path only by switching the discharge and supply of the gas by the pump. Therefore, the configuration is simplified and control is facilitated.

  The control means may close the circulation flow path and open the third flow path when the control of sending the liquid from the first storage section side to the mounting section side is completed. In this case, no liquid remains in the first reservoir. Therefore, the liquid circulation device can discharge the liquid without waste.

  The liquid circulation device includes: a data acquisition unit that acquires image data for controlling discharge of the liquid from the discharge port; and the liquid from the discharge port based on the image data acquired by the data acquisition unit. And a discharge control means for performing control to discharge the liquid. The liquid may be white ink containing titanium oxide. The discharge control unit includes a control for sending the liquid from the mounting unit side to the first storage unit side when the image data for discharging the white ink is acquired by the data acquisition unit, and the first storage unit After the control of feeding the liquid from the side to the mounting portion side is performed by the control means, control for discharging the liquid from the discharge port may be performed. In this case, the liquid circulation device can circulate the white ink before discharging the white ink. Therefore, since the printing operation is not started in a state where the titanium oxide is settled, the printing quality can be improved.

1 is a diagram illustrating an entire configuration of a printing device 1 and a liquid circulation device 3 in a first embodiment. It is a longitudinal cross-sectional view of the 1st storage part 4 in 1st embodiment. FIG. 2 is a block diagram illustrating an electrical configuration of the printing apparatus 1. It is a flowchart of the main process which the printing apparatus 1 of 1st embodiment performs. It is a figure which shows the whole structure of the printing apparatus 101 and the liquid circulation apparatus 103 in 2nd embodiment. FIG. 4 is a diagram showing the configuration of a pump gear 151 and a planetary gear 153 of the pump 107 and a second flow path 17. FIG. 4 is a diagram showing the configuration of a pump gear 151 and a planetary gear 153 of the pump 107 and a second flow path 17. 10 is a flowchart of main processing executed by the printing apparatus 101 according to the second embodiment. It is a longitudinal cross-sectional view of the 1st storage part 204 in a modification.

  Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. First, the overall configuration of the printing apparatus 1 according to the first embodiment and the liquid circulation device 3 included in the printing apparatus 1 will be described with reference to FIG. The printing apparatus 1 is an ink jet printer that mainly performs printing on a recording medium such as resin, cloth, or paper. The printing apparatus 1 can print on a recording medium by ejecting ink from the head 2 according to image data (printing data) while relatively scanning the plurality of heads 2 with respect to the recording medium. A known method may be used as the scanning method of the head 2, the ink ejection method, and the like. Therefore, specific descriptions of the scanning method and the ejection method are omitted.

  The printing apparatus 1 can perform color printing by ejecting a plurality of colors of ink from the head 2. Specifically, in the printing apparatus 1, C (cyan), M (magenta), Y (yellow), K (black), and W (white) inks are ejected from the head 2. The printing apparatus 1 includes a plurality of mounting units for mounting the respective storage units (ink tanks) of CMYKW and a plurality of heads connected to the storage units. The white ink used in this embodiment contains titanium oxide as a pigment. Titanium oxide tends to settle. Therefore, when printing of white ink is not performed for a long time, it is necessary to perform white printing after stirring the white ink.

  The printing apparatus 1 includes a liquid circulation device 3. The liquid circulation device 3 can circulate and stir the white ink stored in the second storage unit 11. The liquid circulation device 3 also has a configuration for circulating CMYK ink. However, the configuration for circulating each ink of CMYK is the same as the configuration for circulating white ink. Therefore, the configuration for circulating white ink will be described below. Needless to say, if it is not necessary to circulate ink other than CMYK, it is sufficient to provide a configuration for circulating only white ink.

  The liquid circulation device 3 mainly includes a first storage unit 4, a pump 7, a communication path 8, a mounting unit 10, a first flow path 14, a second flow path 17, and a third flow path 19. A first valve 21, a second valve 22, and a third valve 23 are provided.

  The 1st storage part 4 is demonstrated. The first storage unit 4 temporarily stores the ink sent from the second storage unit 11 mounted on the mounting unit 10 through the first flow path 14. Further, the first storage unit 4 returns the temporarily stored ink to the second storage unit 11 again through the second flow path 17. As a result, ink is circulated. The first storage unit 4 of the first embodiment includes a box-shaped housing having rigidity, and stores ink in the sealed space 5 inside the housing. The 1st storage part 4 connects the 1st flow path 14 to the upper end part vicinity of a side surface. Therefore, the ink sent from the first flow path 14 into the sealed space 5 flows down from the first flow path 14 to the bottom of the first reservoir 4. Moreover, the 1st storage part 4 connects the 2nd flow path 17 to a bottom part. Therefore, the ink stored in the bottom of the first storage unit 4 smoothly returns to the second storage unit 11 through the second flow path 17.

  The pump 7 and the communication path 8 will be described. A gas flow path 6 is connected to the upper part of the first reservoir 4. The gas flow path 6 connects the sealed space 5 in the first reservoir 4 and the pump 7. The pump 7 is an air pump that discharges the gas in the sealed space 5 to the outside through the gas flow path 6. A communication path 8 branches from the gas flow path 6. The sealed space 5 in the first reservoir 4 is communicated with the atmosphere by the communication path 8.

  The mounting unit 10 will be described. The mounting part 10 mounts | wears with the 2nd storage part 11 so that attachment or detachment is possible. The second storage unit 11 of the present embodiment stores white ink containing titanium oxide inside a rigid casing. However, the second reservoir 11 may be a deformable pack. A vent hole 12 is formed in the upper part of the second reservoir 11, and the interior of the second reservoir 11 is communicated with the atmosphere by the vent 12.

  The first flow path 14 will be described. The first flow path 14 extends from the second storage part 11 attached to the attachment part 10 to the first storage part 4. The first flow path 14 is provided with a third valve 23 described later. Hereinafter, in the first flow path 14, the end from the mounting portion 10 side to the third valve 23 is referred to as a common flow path 15. White ink flows through the common flow path 15 during circulation and printing. Of the first flow path 14, the section from the third valve 23 to the end on the first storage section 4 side is referred to as a circulation flow path 16. White ink flows through the circulation channel 16 during circulation. The end of the common channel 15 on the mounting portion 10 side extends to the vicinity of the bottom of the second storage portion 11 mounted on the mounting portion 10. Accordingly, the printing apparatus 1 can easily use the ink in the second storage unit 11.

  The second flow path 17 will be described. The second flow path 17 extends from the bottom of the first storage unit 4 to the second storage unit 11 mounted on the lower mounting unit 10. That is, the one end part connected to the 1st storage part 4 among the 2nd flow paths 17 is arrange | positioned in the position higher than the lower end part 18 by the side of the mounting part 10. FIG. Therefore, when the sealed space 5 of the first storage unit 4 communicates with the atmosphere, the white ink stored in the first storage unit 4 is sent to the second storage unit 11 through the second flow path 17. The lower end portion 18 of the second flow path 17 is in contact with the inner side surface of the second storage portion 11. Accordingly, the white ink sent from the first reservoir 4 through the second flow path 17 flows downward along the side surface of the second reservoir 11. Therefore, bubbles are less likely to be generated in the white ink as compared with the case where the liquid droplet directly falls on the liquid surface of the stored white ink. As a result, deterioration in print quality due to bubbles is suppressed.

  The third flow path 19 will be described. The third flow path 19 is branched from the first flow path 14 and connected to the head 2. The third valve 23 is connected to all ends of the common flow path 15, the circulation flow path 16, and the third flow path 19. The discharge port of the head 2 connected to the third flow path 19 is disposed at a position higher than the end of the common flow path 15 of the first flow path 14 on the mounting part 10 side (second storage part 11 side). . Accordingly, the white ink does not flow unnecessarily from the ejection port of the head 2 due to the water head difference, and the white ink droplet is ejected downward only when the piezoelectric element of the head 2 is driven.

  The first valve 21, the second valve 22, and the third valve 23 will be described. The first valve 21 opens and closes the second flow path 17. The second valve 22 is provided in the communication path 8. When the communication path 8 is opened by the second valve 22, the sealed space 5 in the first reservoir 4 is communicated with the atmosphere. In this state, when the second flow path 17 is opened by the first valve 21, the white ink in the first reservoir 4 moves to the second reservoir 11. The third valve 23 is provided at the branch point between the first flow path 14 and the third flow path 19. The third valve 23 opens and closes the circulation channel 16 of the first channel 14 and opens and closes the third channel 19. That is, when the third valve 23 opens the circulation channel 16, the white ink in the second reservoir 11 flows to the first reservoir 4 through the common channel 15 and the circulation channel 16. In this case, since the third flow path 19 is closed, the meniscus formed at the discharge port of the head 2 is not destroyed by the power of the pump 7. On the other hand, when the third valve 23 opens the third channel 19, the white ink in the second reservoir 11 flows to the head 2 through the common channel 15 and the third channel 19. In this case, since the circulation channel 16 is closed, the white ink is smoothly supplied to the head 2.

  With reference to FIG. 2, the structure of the 1st storage part 4 is demonstrated in detail. As described above, the first storage unit 4 includes the box-shaped housing 25 having rigidity. An inclined surface 27 that is inclined toward the bottom 26 is formed in the lower portion inside the housing 25. The second flow path 17 is connected to the bottom portion 26 of the housing 25. The white ink stored in the first storage unit 4 flows on the inclined surface 27 toward the bottom 26 and is sent to the second storage unit 11 through the second flow path 17. Therefore, the printing apparatus 1 can smoothly send the white ink in the first storage unit 4 to the second storage unit 11 as compared with the case where the inclined surface 27 is not provided.

  The first reservoir 4 includes a float 28 and a first reservoir sensor 30. The float 28 is a fan-shaped member. The base end portion of the float 28 is swingably supported on the side wall of the housing 25 by a swing shaft 29. The vicinity of the lower end of the tip of the float 28 is in contact with the liquid level of white ink stored in the housing 25. Since the interior of the float 28 is hollow, the float 28 floats on the ink. Accordingly, when the amount of white ink stored in the first storage unit 4 increases, the float 28 is pushed up by the white ink and swings upward about the swing shaft 29. When the amount of white ink stored decreases, the float 28 swings downward. The float 28 includes a magnet inside.

  The first reservoir sensor 30 is fixed in the vicinity of the upper end of the outer surface of the side wall of the housing 25 that supports the float 28. The first reservoir sensor 30 is a Hall element that detects a magnetic field using the Hall effect. When the amount of white ink stored in the first storage unit 4 increases and the float 28 swings upward to the height of the first storage unit sensor 30, the first storage unit sensor 30 detects the magnetic field of the magnet included in the float 28. To do. As a result, the first reservoir sensor 30 detects that the white ink in the first reservoir 4 is full. Therefore, the printing apparatus 1 can prevent the white ink from accidentally touching the pump 7.

  The electrical configuration of the printing apparatus 1 will be described with reference to FIG. The printing apparatus 1 includes a CPU 40 that controls the printing apparatus 1 and the liquid circulation device 3 (see FIG. 1). The CPU 40 includes a RAM 41, a ROM 42, a non-volatile memory 43, a pump 7, a first storage unit sensor 30, an operation panel 45, an external communication I / F 46, a head drive unit 47, a motor drive unit 48, and a valve drive unit 49. Connected via bus.

  The RAM 41 temporarily stores various data such as print data. The ROM 42 stores a control program for controlling the operation of the printing apparatus 1 and the liquid circulation apparatus 3, initial values, and the like. For example, a program for controlling main processing (see FIG. 4) described later is stored in the ROM 42. The nonvolatile memory 43 is a storage element (for example, a flash ROM) that can retain the stored contents even when the power of the printing apparatus 1 is shut off and can read and write data. The operation panel 45 includes a display for displaying various images, an operation unit operated by a user, and the like. The external communication I / F 46 connects the printing apparatus 1 to an external device such as a personal computer (hereinafter referred to as “PC”) 31.

  The head drive unit 47 is connected to the head 2 and drives a piezoelectric element provided in each ejection channel of the head 2. The motor driving unit 48 drives the main scanning motor 33 and the sub scanning motor 34. The main scanning motor 33 moves the head 2 relative to the recording medium in the main scanning direction. The sub scanning motor 34 moves the head 2 relative to the recording medium in the sub scanning direction. The valve drive unit 49 drives the first valve 21, the second valve 22, and the third valve 23.

  With reference to FIG. 4, the main process which the printing apparatus 1 (liquid circulation apparatus 3) of 1st embodiment performs is demonstrated. When the power of the printing apparatus 1 is turned on, the CPU 40 of the printing apparatus 1 executes the main process shown in FIG. 4 according to the program stored in the ROM 42. When the main process is started, it is first determined whether or not an instruction to end the main process (for example, an instruction to turn off the power) is input (S1). If an end instruction has not been input (S1: NO), it is determined whether a print instruction has been input (S2). If no print instruction is input from the operation panel 45 or the PC 31 (see FIG. 3) (S2: NO), the process returns to the determination of S1.

  When a print instruction is input (S2: YES), image data of an image to be printed (that is, image data referred to in the printing process) is acquired (S3). It is determined whether the acquired image data is image data including dots for printing white ink (S5). If the image data does not include dots for printing white ink (S5: NO), the process proceeds to S22 as it is, and printing is executed (S22, S23). Details of the printing operation will be described later.

  If the image data acquired in S3 is image data including dots for printing white ink (S5: YES), it is determined whether or not a predetermined time has elapsed since the previous processing of circulating white ink was performed. (S6). The CPU 40 measures the elapsed time after the white ink circulation process (S7 to S21) described below is completed last time. If the measured elapsed time is not longer than the predetermined time (S6: NO), the sedimentation amount of the substance contained in the white ink is small. Accordingly, the process proceeds to S22 as it is, and printing is executed (S22, S23).

  If the elapsed time is equal to or longer than the predetermined time (S6: YES), the value of the counter n for counting the number of executed white ink circulation processes is set to “1” (S7). Subsequently, the process which sends the white ink in the 2nd storage part 11 to the 1st storage part 4 is performed (S9-S13). First, the second flow path 17 is closed by the first valve 21, and the flow of white ink from the first reservoir 4 to the second reservoir 11 is blocked (S9). The communication path 8 is closed by the second valve 22 to ensure the airtightness of the sealed space 5 in the first reservoir 4 (S10). The circulation channel 16 is opened by the third valve, and the third channel 19 is closed (S11). Thereafter, the pump 7 is driven, and the gas in the sealed space 5 of the first reservoir 4 is discharged to the outside of the first reservoir 4 (S12). As a result, the white ink in the second storage section 11 is sent to the first storage section 4 through the first flow path 14 (the common flow path 15 and the circulation flow path 16).

  It is determined whether or not the white ink in the first storage unit 4 is full and whether or not a predetermined time has elapsed since the pump 7 was driven (S13). The CPU 40 determines whether the white ink in the first storage unit 4 is full based on the detection result of the first storage unit sensor 30. Further, the CPU 40 determines whether or not a predetermined time has elapsed since the drive of the pump 7 in order to prevent the pump 7 from continuing to be driven after the white ink in the first storage unit 4 becomes empty. When the white ink in the first reservoir 4 is not full and the predetermined time has not elapsed (S13: NO), the pump 7 is continuously driven.

  When the white ink in the first reservoir 4 is full or when a predetermined time has elapsed (S13: YES), the drive of the pump 7 is stopped (S15). The second flow path 17 is opened by the first valve 21 (S16), and the communication path 8 is opened by the second valve 22 (S17). As a result, the white ink temporarily stored in the first storage unit 4 is returned to the second storage unit 11 through the second flow path 17.

  It is determined whether the remaining amount of white ink in the first storage unit 4 has become “0” (S18). In the present embodiment, the remaining amount of white ink in the first reservoir 4 becomes “0” when a predetermined time has elapsed since the movement of the white ink to the second reservoir 11 was started in S15 to S17. Judge that it became. However, the determination method of the remaining amount of the first storage unit 4 can be changed as appropriate. For example, a sensor for detecting the remaining amount of white ink may be installed in the first storage unit 4 and the remaining amount may be determined based on the detection result of the installed sensor. Until the remaining amount of white ink in the first reservoir 4 reaches “0” (S18: NO), the standby state is maintained. When the remaining amount becomes “0” (S18: YES), it is determined whether or not the value of the counter n is N (N is a constant) (S20). The value of the constant N may be set as appropriate according to the properties of the white ink, the capacity of the first storage unit 4, the capacity of the second storage unit 11, and the like.

  If the value of the counter n is less than N (S20: NO), “1” is added to the value of n (S21), the process returns to S9, and the white ink circulation process is executed again (S9 to S9). S20). If the value of the counter n is N (S20: YES), the circulation channel 16 is closed by the third valve 23, and the third channel 19 is opened (S22). Thereafter, scanning of the head 2 and ink ejection control are performed, and printing is executed (S23). When printing is completed, the process returns to the determination in S1. When an end instruction is input (S1: YES), the main process ends.

  As described above, the printing apparatus 1 (liquid circulation apparatus 3) according to the first embodiment discharges the gas in the first reservoir 4 to the outside with the second flow path 17 and the communication path 8 closed. By doing so, the liquid (white ink) is sent from the second reservoir 11 to the first reservoir 4 through the first flow path 14. By opening the second flow path 17 and the communication path 8, white ink is sent from the first storage section 4 to the second storage section 11 through the second flow path 17. Therefore, the printing apparatus 1 can circulate white ink without passing white ink through the pump 7 only by controlling the pump 7, the first valve 21, and the second valve 22.

  In the printing apparatus 1, the end connected to the first storage unit 4 in the second flow path 17 is located at a position higher than the end on the mounting unit 10 side. Therefore, when the white ink is sent from the first reservoir 4 to the second reservoir 11, the printing apparatus 1 simply opens the second flow path 17 and the communication path 8 and does not drive the pump 7. Ink can be sent. Therefore, the white ink can be circulated efficiently and easily.

  The printing apparatus 1 includes a third valve 23 that opens and closes the circulation flow path 16 and opens and closes the third flow path 19. When the printing apparatus 1 sends white ink from the second storage unit 11 to the first storage unit 4, the circulation valve 16 is opened by the third valve 23, and the third flow path 19 is closed and the pump 7 is turned on. To drive. Therefore, the power of the pump 7 does not affect the liquid in the head 2. Therefore, the printing apparatus 1 can suppress the occurrence of problems such as breakage of the meniscus formed in the head 2.

  When the white ink is sent from the second reservoir 11 to the first reservoir 4, the printing apparatus 1 starts suction by the pump 7 after opening the circulation channel 16 by the third valve 23. Therefore, the printing apparatus 1 can suppress the occurrence of problems due to a rapid pressure change, compared to the case where the circulation channel 16 is opened after the pressure of the gas in the sealed space 5 is reduced. For example, it is possible to suppress the generation of bubbles in the ink and the deformation / deterioration of parts such as flow paths.

  The first reservoir 4 has an inclined surface 27 that is inclined downward toward the bottom 26. The second flow path 17 is connected to the bottom part 26 of the first storage part 4. Therefore, the printing apparatus 1 can smoothly flow the white ink in the first storage unit 4 through the second flow path 17. The amount of white ink remaining in the first reservoir 4 is also reduced.

  When the control for sending the white ink from the first reservoir 4 to the second reservoir 11 is completed, the printing apparatus 1 closes the circulation channel 16 and opens the third channel 19 to execute printing. . Therefore, the printing apparatus 1 can prevent white ink from remaining in the first storage unit 4. The printing apparatus 1 performs control to circulate white ink when image data for ejecting white ink is acquired at the start of printing, and then performs printing. Accordingly, it is possible to circulate the white ink at an appropriate timing before discharging the white ink. Since the printing operation is not performed in a state where the titanium oxide is settled, the printing quality is improved.

  In the first embodiment, the first valve 21 corresponds to the “first opening / closing means” of the present invention. The second valve 22 corresponds to the “second opening / closing means” of the present invention. The third valve 23 corresponds to the “third opening / closing means” of the present invention. The CPU 40 that executes the main process shown in FIG. 4 functions as the “control unit” of the present invention. The head 2 corresponds to the “ejection unit” of the present invention. The CPU 40 that acquires image data in S3 of FIG. 4 corresponds to the “data acquisition unit” of the present invention. The CPU 40 that controls the printing operation in S23 of FIG. 4 functions as an “ejection control unit”.

  A second embodiment of the present invention will be described with reference to FIGS. In the printing apparatus 101 and the liquid circulation apparatus 103 according to the second embodiment, the configuration of the pump 107, the presence / absence of the check valve 126, the control contents when circulating the white ink, and the like are only different from the printing apparatus 1 according to the first embodiment. It is. Accordingly, in the description of the second embodiment, the same configurations and processes as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and description thereof is omitted or simplified.

  With reference to FIG. 5, the structure of the printing apparatus 101 and the liquid circulation apparatus 103 of 2nd embodiment is demonstrated. The liquid circulation device 103 according to the second embodiment mainly includes the first storage unit 4, the pump 107, the mounting unit 10, the first flow channel 14, the second flow channel 17, and the third flow channel 19. A fifth valve 125 and a check valve 126 are provided.

  The pump 107 of the second embodiment can supply the gas into the sealed space 5 from the outside in addition to discharging the gas in the sealed space 5 of the first storage unit 4 to the outside. Further, the pump 107 is provided at a position adjacent to the second flow path 17, and can close the second flow path 17 while discharging the gas in the sealed space 5 to the outside. Details of this will be described later with reference to FIGS. The gas flow path 106 connected to the upper part of the first reservoir 4 is bent and extends to the pump 107. In 2nd embodiment, it is not necessary to provide the communicating path 8 (refer FIG. 1) for connecting the sealed space 5 to air | atmosphere.

  The mounting unit 10 mounts the second storage unit 11 in a detachable manner, as in the first embodiment. A vent 12 is formed in the upper part of the second reservoir 11 to allow the internal gas to communicate with the atmosphere. When the second storage unit 11 is mounted on the mounting unit 10, the lower end 18 of the second flow path 17 comes into contact with the inner side surface of the second storage unit 11. The first flow path 14 extends from the second storage part 11 attached to the attachment part 10 to the first storage part 4. The third flow path 19 is branched from the first flow path 14 and connected to the head 2. The fifth valve 125 is connected to the common flow path 15 and the circulation flow path 16 of the first flow path 14 and the third flow path. The discharge port of the head 2 connected to the third flow path 19 is disposed at a position higher than the end of the common flow path 15 of the first flow path 14 on the mounting part 10 side (second storage part 11 side). .

  The check valve 126 is provided in the circulation flow path 16 of the first flow path 14. The check valve 126 permits the movement of the fluid from the second reservoir 11 side to the first reservoir 4 side through the circulation channel 16 and from the first reservoir 4 side to the second reservoir 11 side. Prohibit fluid movement to Therefore, even if gas is supplied to the sealed space 5 of the first reservoir 4, the white ink and gas in the circulation channel 16 do not flow to the second reservoir 11 side.

  With reference to FIG. 6 and FIG. 7, the operation | movement which the pump 107 of 2nd embodiment opens and closes the 2nd flow path 17 is demonstrated in detail. As shown in FIGS. 6 and 7, the pump 107 includes a pump gear 151 that discharges (sucks) gas from the sealed space 5 and supplies gas to the sealed space 5. The pump 107 of the second embodiment supplies gas from the outside to the sealed space 5 by rotating the pump gear 151 in the clockwise direction of FIG. 6 (the “second direction” in the present invention). Further, the pump 107 rotates the pump gear 151 in the counterclockwise direction of FIG. 7 (the “first direction” in the present invention) to discharge the gas in the sealed space 5 to the outside.

  The pump 107 includes a planetary gear 153. The planetary gear 153 rotates in the direction opposite to the pump gear 151 around the rotation shaft 154 by meshing with the pump gear 151. The pump 107 also includes a guide 156 that guides the movement of the rotating shaft 154 of the planetary gear 153. As shown in FIG. 6, when the pump gear 151 rotates clockwise, the planetary gear 153 moves away from the second flow path 17 while rotating counterclockwise. As shown in FIG. 7, when the pump gear 151 rotates counterclockwise, the planetary gear 153 moves in a direction approaching the second flow path 17 while rotating clockwise.

  A cover 158 for protecting the second flow path 17 is provided between the second flow path 17 and the planetary gear 153. The cover 158 may be formed of, for example, a resin film. As shown in FIG. 6, when the pump gear 151 rotates clockwise, gas is supplied to the sealed space 5, the planetary gear 153 is separated from the second flow path 17, and the second flow path 17 is opened. As a result, the white ink in the first reservoir 4 is sent to the second reservoir 11 through the second flow path 17. On the other hand, as shown in FIG. 7, when the pump gear 151 rotates counterclockwise, the gas in the sealed space 5 is discharged to the outside, and the planetary gear 153 pushes the second flow path 17 to push the second flow path 17. Is closed. As a result, the white ink in the second reservoir 11 is sent to the first reservoir 4 through the first flow path 14. At this time, since the cover 158 is interposed between the second flow path 17 and the planetary gear 153, the possibility that the second flow path 17 is damaged or deteriorated by the planetary gear 153 is reduced.

  With reference to FIG. 8, the main process which the printing apparatus 101 (liquid circulation apparatus 103) of 2nd embodiment performs is demonstrated. When the power is turned on, the CPU 40 of the printing apparatus 101 executes main processing shown in FIG. 8 according to a program stored in the ROM 42. First, it is determined whether or not an instruction to end the main process is input (S1). If an end instruction has not been input (S1: NO), it is determined whether a print instruction has been input (S2). If no print instruction is input (S2: NO), the process returns to the determination of S1. When a print instruction is input (S2: YES), image data of an image to be printed is acquired (S3). It is determined whether the acquired image data is image data including dots for printing white ink (S5). If the white ink dot is not included (S5: NO), the process proceeds to S105 as it is, and printing is executed (S105, S23).

  If the image data includes white ink dots (S5: YES), it is determined whether or not a predetermined time has elapsed since the previous white ink circulation (S6). If it has not elapsed (S6: NO), the process proceeds to S105 as it is. If it has elapsed (S6: YES), the value of the counter n for counting the number of circulation processes is set to “1” (S7). The circulation channel 16 is opened by the fifth valve 125, and the third channel 19 is closed (S101). Thereafter, the pump 107 is driven, and the gas in the sealed space 5 of the first reservoir 4 is discharged (sucked) to the outside (S102). As described above, while the gas in the sealed space 5 is being exhausted by the pump 107, the second flow path 17 is closed by the planetary gear 153 of the pump 107. Therefore, the white ink in the second reservoir 11 is sent to the first reservoir 4 through the first flow path 14.

  It is determined whether or not the white ink in the first reservoir 4 is full and whether or not a predetermined time has elapsed since the suction by the pump 107 was started (S13). When the white ink in the first reservoir 4 is not full and the predetermined time has not elapsed (S13: NO), the suction by the pump 107 is continued. When the white ink in the first reservoir 4 is full or when a predetermined time has elapsed (S13: YES), the rotation of the pump gear 151 in the pump 107 is reversed, and the gas to the sealed space 5 is Supply is started (S104). As described above, the second flow path 17 is opened while the gas is supplied into the sealed space 5 by the pump 107. Further, since the check valve 126 is provided in the first flow path 14, white ink does not flow from the first reservoir 4 to the first flow path 14. Therefore, the white ink in the first reservoir 4 is pushed out to the second reservoir 11 through the second flow path 17.

  It is determined whether the remaining amount of white ink in the first storage unit 4 has become “0” (S18). In the second embodiment, whether or not the remaining amount of white ink in the first reservoir 4 has become “0” is determined based on the number of rotations of the pump gear 151 after the processing of S104 is performed. Therefore, the printing apparatus 101 can accurately and easily determine the remaining amount of white ink without using a sensor or the like. Until the remaining amount of white ink in the first reservoir 4 reaches “0” (S18: NO), the standby state is maintained. When the remaining amount becomes “0” (S18: YES), it is determined whether or not the value of the counter n is N (N is a constant) (S20). If the value of the counter n is less than N (S20: NO), “1” is added to the value of n (S21), and the process returns to S101.

  If the value of the counter n is N (S20: YES), the circulation channel 16 is closed by the fifth valve 125, and the third channel 19 is opened (S105). Thereafter, scanning of the head 2 and ink ejection control are performed, and printing is executed (S23). When printing is completed, the process returns to the determination in S1. When an end instruction is input (S1: YES), the main process ends.

  As described above, the printing apparatus 101 (liquid circulation apparatus 103) according to the second embodiment first closes the second flow path 17 and the third flow path 19 and opens the circulation flow path 16, and then By discharging the gas in the sealed space 5 of the storage unit 4, the white ink is sent from the second storage unit 11 to the first storage unit 4 through the first flow path 14. Therefore, it is possible to send white ink from the second storage unit 11 to the first storage unit 4 while suppressing generation of bubbles in the white ink due to a sudden pressure change. During this time, since the third flow path 19 is closed, it is difficult for the head 2 to affect the white ink. The check valve 126 prohibits the fluid from moving through the circulation channel 16 from the first reservoir 4 to the second reservoir 11 side. Therefore, the printing apparatus 101 can send white ink from the first reservoir 4 to the second reservoir 11 simply by supplying gas into the first reservoir 4. Therefore, the printing apparatus 101 can easily circulate the white ink without passing the white ink through the pump 107.

  The pump 107 of the printing apparatus 101 can close the second flow path while discharging the gas in the sealed space 5. Furthermore, the second flow path 17 can be opened while supplying gas to the sealed space 5. That is, the printing apparatus 1 can switch between the closing and opening of the second flow path 17 only by switching the discharge and supply of gas by the pump 107. Therefore, the configuration is simplified and control is easy.

  In the second embodiment, the planetary gear 153 corresponds to the “fourth opening / closing means” of the present invention. The fifth valve 125 corresponds to the “fifth opening / closing means” of the present invention. The check valve 126 corresponds to the “sixth opening / closing means” of the present invention.

  It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the configuration of the first storage unit 4 may be changed. With reference to FIG. 9, the 1st storage part 204 which concerns on a modification is demonstrated. The first storage unit 204 according to the modification mainly includes a pack 224, a pack storage body 225, a stepped part 226, a float 228, and a first storage unit sensor 230. The pack 224 can maintain internal airtightness, and contains white ink inside. The pack 224 is formed of a resin film and is flexible and deformable. The first channel 14 (circulation channel 16) is connected to the upper end of the pack 224. A second flow path 17 is connected to the lower end of the pack 224. The pack storage body 225 is a box-shaped member having a substantially rectangular parallelepiped shape, and is made of synthetic resin and has rigidity. The pack 224 is stored in the pack storage body 225. The pack storage body 225 can form the sealed space 5 therein. A gas flow path 206 extending from the pumps 7 and 107 (see FIGS. 1 and 5) is connected to the sealed space 5. The step portion 226 is formed in a portion of the lower part of the pack housing 225 where the second flow path 17 is not connected. A part of the pack 224 is placed on the step portion 226. Therefore, the white ink stored in the pack 224 flows smoothly into the second flow path 17.

  The float 228 is a fan-shaped member. The base end portion of the float 228 is swingably supported on the side wall of the pack storage body 225 by the swing shaft 229. The vicinity of the lower end portion of the float 228 is in contact with the pack 224. Therefore, when the white ink in the pack 224 increases, the float 228 is pushed up by the pack 224 and swings upward. When the white ink in the pack 224 occurs, the float 228 swings downward. The float 228 includes a magnet inside. The first reservoir sensor 230 is a Hall element, and is fixed in the vicinity of the upper end of the outer surface of the side wall of the pack housing 225. When the float 228 swings up to a predetermined position, the first reservoir sensor 230 detects the flow and the magnetic field of the magnet 228. As a result, it is detected that the white ink in the pack 224 is full. As described above, the first storage unit 204 including the pack 224 that stores white ink can be used instead of the first storage unit 4 of the above-described embodiment. In this case, since the frequency with which the white ink comes into contact with the gas decreases, drying of the white ink can be prevented.

  Other variations are possible for the above embodiment. For example, the printing apparatus 1 according to the first embodiment includes a liquid circulation device 3. However, in the printing apparatus 1, the mechanism for executing printing and the liquid circulation device 3 can be separated. In the first embodiment, one CPU 40 serves as both print control and white ink circulation control. However, a processor that controls printing and a processor that controls white ink circulation may be provided separately.

  The mounting unit 10 of the above embodiment mounts the second storage unit 11 in a detachable manner. However, the present invention can also be applied to a printing apparatus in which the second storage unit 11 cannot be replaced. In this case, the user may replenish ink in the second storage unit 11 by injecting ink into the second storage unit 11 or the like. That is, the “mounting part” of the present invention may be at least a part where the second storage part is attached at the time of manufacturing the liquid circulation device, and need not be a part where the second storage part is exchangeably attached.

  The printing apparatuses 1 and 101 of the above embodiment improve the print quality by circulating white ink containing titanium oxide. However, as described above, the present invention can also be applied to the case where other inks other than the white ink are circulated. The present invention can also be applied to the case of circulating a liquid other than ink (for example, a pretreatment agent for forming a base of ink).

  The printing apparatuses 1 and 101 of the embodiment detect whether the white ink in the first storage unit 4 is full or not by the float 28 and the first storage unit sensor 30. However, it may be detected using a photo sensor or the like whether or not the white ink in the first reservoir 4 is full. Moreover, you may detect whether the white ink in the 1st storage part 4 became empty using the float 28, a photo sensor, etc. FIG. Further, it may be detected whether or not the amount of white ink has reached a predetermined amount, such as near full, not full.

  The printing apparatus 1 of the first embodiment starts suction by the pump 7 after driving the first valve 21, the second valve 22, and the third valve 23. Therefore, it is possible to suppress the occurrence of problems due to a sudden pressure change. However, the printing apparatus 1 can also drive the valves 21 to 23 after the suction by the pump 7 is started. In this case, white ink can be sent vigorously.

  In the printing apparatuses 1 and 101 of the above embodiment, the second flow path 17 is connected to the bottom 26 of the first reservoir 4. Accordingly, the white ink in the first reservoir 4 flows smoothly into the second flow path 17. However, the second flow path 17 may be connected to the inclined surface 27. Even if the inclined surface 27 is not provided in the first storage part 4, the present invention can be realized.

  The third valve 23 in the first embodiment performs both opening and closing of the circulation channel 16 and opening and closing of the third channel 19. The same applies to the fifth valve 125 in the second embodiment. However, a valve for opening and closing the circulation channel 16 and a valve for opening and closing the third channel 19 may be provided separately. In this case, the two valves provided separately correspond to the “third opening / closing means” and the “fifth opening / closing means” of the present invention. Further, the pump 107 of the second embodiment can open and close the second flow path 17 in addition to the discharge and pressurization of the gas in the sealed space 5. However, an opening / closing means (for example, a valve) for opening and closing the second flow path 17 may be provided separately from the pump 107.

  The printing apparatuses 1 and 101 of the above embodiment circulate white ink before printing white ink. Therefore, the white ink can be circulated efficiently at an appropriate timing. However, it is also possible to change the timing for executing the white ink circulation. For example, the white ink may be circulated periodically at regular intervals.

  In the said embodiment, the capacity | capacitance of the 2nd storage part 11 is larger than the capacity | capacitance of the 1st storage part 4. FIG. However, the capacity of the first storage part 4 can be made larger than the capacity of the second storage part 11. In this case, the white ink in the first storage unit 4 does not become full. Therefore, the printing apparatuses 1 and 101 can omit the configuration and processing for detecting whether or not the first storage unit 4 is full.

DESCRIPTION OF SYMBOLS 1,101 Printing apparatus 2 Head 3,103 Liquid circulation apparatus 4 First storage part 5 Sealed space 7, 107 Pump 8 Communication path 10 Mounting part 11 Second storage part 14 First flow path 15 Common flow path 16 Circulation flow path 17 Second flow path 19 Third flow path 21 First valve 22 Second valve 23 Third valve 26 Bottom 27 Inclined surface 40 CPU
125 Fifth valve 126 Check valve 151 Pump gear 153 Planetary gear

Claims (7)

A first reservoir capable of storing liquid and forming a sealed space therein;
A mounting part for storing the liquid and mounting a second storage part whose inside communicates with the atmosphere;
A pump connected to the first reservoir, and discharging the gas in the sealed space to the outside of the first reservoir;
A first flow path connected to the first storage part and the mounting part;
A second flow path that is connected to the first storage part and the mounting part, and in which one end connected to the first storage part is positioned higher than the other end connected to the mounting part. When,
First opening and closing means for opening and closing the second flow path;
A communication path for communicating the sealed space of the first storage part with the atmosphere;
Second opening and closing means for opening and closing the communication path;
Control means for controlling driving of the pump, opening and closing of the first opening and closing means, and opening and closing of the second opening and closing means,
The control means includes
When sending the liquid from the mounting part side to the first storage part side, the second flow path is closed by the first opening and closing means, and the communication path is closed by the second opening and closing means, Drive the pump to discharge the gas in the sealed space in the first reservoir to the outside,
When the liquid is sent from the first storage section side to the mounting section side, the second flow path is opened by the first opening / closing means, and the communication path is opened by the second opening / closing means. A liquid circulation device. A discharge part having a discharge port for discharging the liquid;
A third flow path branched from the first flow path and connected to the discharge section;
According to control by the control means, the circulation channel, which is a portion extending from the branch point of the first channel with the third channel to the first storage part, and the third channel are opened and closed. A third opening / closing means;
The discharge port of the discharge unit is disposed at a position higher than an end connected to the mounting unit in the first flow path,
The control means includes
When the liquid is sent from the mounting part side to the first storage part side, the circulation channel is opened by the third opening / closing means, and the pump is driven after the third channel is closed. Letting the gas in the sealed space in the first storage part to the outside,
2. The liquid circulation device according to claim 1, wherein when the liquid is discharged from the discharge portion, the third flow path is closed by the third opening / closing means and the third flow path is opened. . The first reservoir has an inclined surface inclined toward the bottom,
3. The liquid circulation device according to claim 1, wherein the first storage portion side end portion of the second flow path is connected to the inclined surface or the bottom portion. A first reservoir capable of storing liquid and forming a sealed space therein;
A mounting part for storing the liquid and mounting a second storage part whose inside communicates with the atmosphere;
A pump that is connected to the first storage unit, discharges the gas in the sealed space to the outside, and supplies the gas into the sealed space;
A first flow path and a second flow path connected to the first storage section and the mounting section;
A fourth opening / closing means for opening and closing the second flow path;
A discharge part having a discharge port for discharging the liquid;
A third flow path branched from the first flow path and connected to the discharge section;
A fifth opening / closing means for opening and closing the circulation channel, which is a portion extending from the branch point to the third channel in the first channel to the first reservoir, and opening and closing the third channel;
It is arranged in the circulation channel, permits movement of the fluid from the mounting part side to the first storage part side through the circulation channel, and from the first storage part side to the mounting part side. Sixth opening and closing means for prohibiting movement of the fluid;
Control means for controlling driving of the pump, opening and closing of the fourth opening and closing means, and opening and closing of the fifth opening and closing means,
The discharge port of the discharge unit is disposed at a position higher than an end connected to the mounting unit in the first flow path,
The control means includes
When the liquid is sent from the mounting portion side to the first storage portion side, the pump is driven after the circulation channel is opened and the third channel is closed by the fifth opening / closing means. , Exhausting the gas in the sealed space in the first reservoir to the outside in a state where the second flow path is closed by the fourth opening and closing means,
When the liquid is sent from the first reservoir to the mounting portion, the pump is driven and the second flow path is opened by the fourth opening / closing means, and the sealing in the first reservoir is performed. Supplying gas to the space,
When the liquid is discharged from the discharge section, the liquid circulation device is characterized in that the fifth flow path closes the circulation flow path and opens the third flow path. The pump is
By rotating in the first direction, the gas in the sealed space in the first storage section is discharged to the outside, and by rotating in the second direction opposite to the first direction, the first storage A pump gear for supplying gas to the sealed space in the section;
The fourth opening / closing means includes
While meshing with the pump gear, the pump gear rotates in the first direction to press and close the second flow path, and the pump gear rotates in the second direction to 5. The liquid circulation device according to claim 4, wherein the liquid circulation device is a gear to be opened.   The control means closes the circulation flow path and opens the third flow path when the control of sending the liquid from the first storage section side to the mounting section side is completed. The liquid circulation device according to any one of claims 2 to 5. Data acquisition means for acquiring image data for controlling discharge of the liquid by the discharge port;
Discharge control means for performing control to discharge the liquid from the discharge port based on the image data acquired by the data acquisition means;
The liquid is a white ink containing titanium oxide,
The discharge control means includes
When the image data for ejecting the white ink is acquired by the data acquisition unit, control for sending the liquid from the mounting unit side to the first storage unit side, and from the first storage unit side to the mounting unit side 7. The liquid circulation device according to claim 2, wherein after the control to send the liquid to the control unit is performed by the control unit, the control is performed to discharge the liquid from the discharge port.

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