JP2017202659A - Liquid supply device and liquid discharge device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain occurrence of caking caused by precipitation and solidification of the solid component in a discharging liquid in the liquid flow channel of a liquid discharge head even if a discharging liquid storage part comes short of the discharging liquid.SOLUTION: A liquid supply device 100 is a device for supplying a discharging liquid I including a solid component from a discharging liquid storage part 110 to a liquid flow channel in the liquid discharge heads 4a, 4b passing through a supply passage 102. The device is characterized by having a non-discharge liquid supply means 121 supplying a non-discharge liquid S which is lower in solid component content than the discharging liquid or does not contain the solid component from a non-discharge liquid storage part 120 to the liquid flow channel in the liquid discharge head when the residual quantity of the discharging liquid in the discharging liquid storage part is a regulation value or less.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a liquid supply device and a device for discharging a liquid.

  2. Description of the Related Art Conventionally, a liquid supply device that supplies ink from an ink cartridge to a liquid flow path in a liquid discharge head through a supply passage is known.

  For example, Patent Document 1 discloses a mechanism for supplying pigment ink from an ink cartridge connected to a cartridge holder to a liquid flow path in a print head fixed to the lower surface of the cartridge holder via an ink passage. Yes. The ink cartridge is composed of an ink storage part that holds an ink absorbing material inside and stores pigment ink, and an ink supply part that has a communication path connected to the lower part of the ink storage part. The pigment ink absorbed by the ink absorbing material in the ink storage unit is sucked out to the ink supply unit by the suction force from the communication path, and the pigment ink is discharged from the ink cartridge to the ink path. According to Patent Document 1, the pigment ink in the ink reservoir is held in a state of being absorbed by the ink absorbing material, so that the precipitation of the pigment particles in the pigment ink is unlikely to occur.

  In the ink cartridge described in Patent Document 1, the second ink absorbing material is embedded in the opening of the communication path located inside the ink reservoir. Thereby, according to the said patent document 1, it can suppress that the pigment ink which exudes from the ink absorption material in an ink storage part is supplied in a communicating path at the time of leaving, and pigment particle density | concentration becomes high in a communicating path. It is said that it is possible to suppress the occurrence of ink portions (sedimented ink).

  In general, solid components in the discharge liquid such as pigment ink, when precipitated in the liquid flow path of the liquid discharge head, solidify and become difficult to re-disperse, which may hinder the discharge operation due to the solidification (caking). There is. In addition, the caking of solid components in the discharge liquid may adhere to the diaphragm filter section (filter section installed near the diaphragm) of the liquid discharge head, etc., causing ink clogging and hindering the discharge operation. is there. Such caking can be prevented in advance by appropriately performing various maintenance and recovery operations.

  Various maintenance and recovery operations are usually performed during the non-image forming operation period by discharging the discharge liquid in the liquid discharge head (empty discharge) or by circulating the discharge liquid through a predetermined circulation path. By causing the liquid to flow, the discharge liquid is agitated to suppress caking. However, since such a maintenance and recovery operation requires the supply of the discharge liquid from the discharge liquid storage section such as an ink cartridge, it can be appropriately performed when the discharge liquid in the discharge liquid storage section is insufficient. become unable. For this reason, if the discharge liquid in the discharge liquid storage part is left for a long period with a shortage, the maintenance and recovery operation cannot be performed for a long period of time, and caking occurs.

  In order to solve the above-described problem, the present invention includes a discharge liquid supply unit that supplies a discharge liquid containing a solid component from a discharge liquid storage unit to a liquid channel in a liquid discharge head through a supply passage. In the liquid supply device, when the remaining amount of the discharge liquid in the discharge liquid storage unit is equal to or less than a specified amount, the non-discharge liquid that has a lower solid component content than the discharge liquid or does not contain a solid component A non-discharge liquid supply means for supplying the liquid from the non-discharge liquid storage section to the liquid flow path in the liquid discharge head.

  According to the present invention, even when the discharge liquid in the discharge liquid reservoir is insufficient, the occurrence of caking that solidifies in the discharge liquid and settles in the liquid flow path of the liquid discharge head is suppressed. The excellent effect that it can be performed is produced.

It is a perspective view which shows an example of the inkjet recording device in embodiment. It is the top view which showed typically the mechanism part of the inkjet recording device. FIG. 3 is an explanatory diagram when the liquid discharge head in the ink jet recording apparatus is viewed from the nozzle surface side. It is a block diagram which shows the outline | summary of the control part of the inkjet recording device. (A) is explanatory drawing which shows the distribution state of the pigment component in the ink immediately after stirring. (B) is an explanatory view showing the distribution state of the pigment component in the ink after being allowed to stand after stirring. It is a schematic diagram which shows the structure of the ink supply mechanism in the same inkjet recording device. It is a schematic diagram which shows the other example of the ink supply mechanism. It is a schematic diagram which shows the further another example of the ink supply mechanism. It is a schematic diagram which shows the further another example of the ink supply mechanism. 5 is a timing chart illustrating an example of a maintenance / recovery operation during a non-image forming operation period in the embodiment. It is explanatory drawing which shows distribution of the ink and alternative liquid immediately after the supply start of the alternative liquid from an alternative liquid cartridge. FIG. 6 is an explanatory diagram showing the distribution of ink and alternative liquid after a predetermined time has elapsed since the supply of alternative liquid from the alternative liquid cartridge was started. FIG. 10 is a schematic diagram showing a configuration of an ink supply mechanism in Modification 1. (A) is explanatory drawing which shows distribution of the ink and alternative liquid immediately after the supply start of the alternative liquid from an alternative liquid tank in the ink supply mechanism. (B) is an explanatory view showing the distribution of ink and alternative liquid after a predetermined time has elapsed since the supply of the alternative liquid from the alternative liquid tank was started in the ink supply mechanism. (C) is an explanatory view showing the distribution of ink and alternative liquid after a further time has elapsed since the supply of the alternative liquid from the alternative liquid tank was started in the ink supply mechanism. 10 is a flowchart showing a control flow when the timing for performing an idle discharge operation in Modification 2 has arrived. It is principal part top explanatory drawing which shows an example of a liquid discharge unit. It is front explanatory drawing which shows the other example of a liquid discharge unit.

Hereinafter, an embodiment in which the present invention is applied to a liquid supply apparatus that supplies an ejection liquid to a liquid ejection head of an ink jet recording apparatus that is an apparatus for ejecting liquid will be described.
FIG. 1 is a perspective view illustrating an example of an ink jet recording apparatus according to the present embodiment.
FIG. 2 is a plan view schematically showing a mechanism part of the ink jet recording apparatus according to the present embodiment.
The ink jet recording apparatus 1 according to the present embodiment is of a serial type, and a carriage 3 is movably held by a main guide member 2 and a sub guide member that are horizontally mounted on a side plate of the apparatus main body. When the timing belt 8 spanned between the driving pulley 6 and the driven pulley 7 is moved by the driving force of the main scanning motor 5, the carriage 3 attached to the timing belt 8 is moved to the main guide member 2 and the driven guide member. Along the main scanning direction (left-right direction in FIG. 2).

  Two liquid discharge heads 4 a and 4 b are mounted on the carriage 3. The liquid discharge heads 4a and 4b are provided with a nozzle row in which a plurality of nozzles (discharge ports) are arranged in the sub-scanning direction orthogonal to the main scanning direction on the nozzle surface, and the carriage 3 so that the nozzle surface faces downward. It is attached to. The liquid discharge heads 4a and 4b in the present embodiment discharge yellow (Y), cyan (C), magenta (M), and black (K) inks (discharge liquid).

FIG. 3 is an explanatory diagram when the liquid discharge heads 4a and 4b are viewed from the nozzle surface side.
As shown in FIG. 3, the liquid ejection heads 4a and 4b have two nozzle rows Na and Nb in which a plurality of nozzles 4n are arranged, respectively. In one liquid discharge head 4a, one nozzle row Na discharges black (K) droplets, and the other nozzle row Nb discharges cyan (C) droplets. In the other liquid discharge head 4b, one nozzle row Na discharges magenta (M) droplets, and the other nozzle row Nb discharges yellow (Y) droplets. The liquid discharge heads 4a and 4b are discharged using, for example, a method using a piezoelectric actuator such as a piezoelectric element, or a method using a thermal actuator that uses a phase change caused by liquid film boiling using an electrothermal transducer such as a heating resistor. A method using an electrostatic actuator composed of a diaphragm and a counter electrode can be used and is not particularly limited.

  The ink jet recording apparatus 1 of the present embodiment is provided with a transport mechanism 51 that transports the paper 10 to a recording area facing the liquid ejection heads 4a and 4b. The transport mechanism 51 includes an endless transport belt 12 that is stretched between the transport roller 13 and the tension roller 14. When the timing belt 17 and the timing pulley 18 are driven by the driving force of the sub-scanning motor 16, the conveyance roller 13 is driven to rotate, and the conveyance belt 12 rotates in the sub-scanning direction. The conveyor belt 12 is charged by the charging roller while rotating around, electrostatically attracts the sheet 10 to the surface of the conveyor belt 12, and conveys the sheet 10 as the conveyor belt 12 moves.

  Further, as shown in FIG. 2, on both sides of the carriage 3 in the main scanning direction, on the sides of the conveyance belt 12, maintenance and recovery as a maintenance and recovery operation executing means for executing the maintenance and recovery operation of the liquid ejection heads 4 a and 4 b. Mechanisms 20 and 21 are arranged. The first maintenance / recovery mechanism 20 disposed on one side of the carriage 3 in the main scanning direction is, for example, a cap member 20a for capping the nozzle surfaces of the liquid ejection heads 4a and 4b, a wiper member 20b for wiping the nozzle surfaces, and the like. It is configured. The second maintenance / recovery mechanism 21 disposed on the other side of the carriage 3 in the main scanning direction includes an empty discharge receiving portion that receives empty discharge from the liquid discharge heads 4a and 4b.

  An encoder scale 23 having a predetermined pattern is disposed between both side plates along the main scanning direction of the carriage 3. The carriage 3 is provided with an encoder sensor 24 composed of a transmissive photosensor that reads the pattern of the encoder scale 23. The encoder scale 23 and encoder sensor 24 constitute a linear encoder (main scanning encoder) that detects the movement amount and position (main scanning direction position) of the carriage 3.

  A code wheel 25 is attached to the rotation shaft of the transport roller 13, and an encoder sensor 26 including a transmission type photo sensor that detects a pattern formed on the code wheel 25 is provided on the apparatus main body side. ing. The code wheel 25 and the encoder sensor 26 constitute a rotary encoder (sub-scanning encoder) that detects the movement amount and position (sub-scanning direction position) of the conveyor belt 12.

  In the ink jet recording apparatus according to the present embodiment, the paper 10 from the paper feed tray is fed onto the charged transport belt 12 and sucked, and transported in the sub-scanning direction as the transport belt 12 rotates, It is sent to a recording area facing the liquid discharge heads 4a and 4b. Then, while moving the carriage 3 in the main scanning direction, the liquid ejection heads 4a and 4b are driven in accordance with the image signals (image information), and ink is ejected onto the stopped paper 10, and an image for one line is formed. Record. Thereafter, after the transport belt 12 is moved by a predetermined amount, the liquid ejection heads 4a and 4b are driven while the carriage 3 is moved again in the main scanning direction to eject ink, and an image in the next row is recorded. This process is repeated, and upon receiving a recording end signal or a signal that the trailing edge of the paper 10 has reached the recording area, the image forming operation is terminated, and the paper 10 is discharged onto the paper discharge tray.

FIG. 4 is a block diagram illustrating an overview of the control unit 500 of the inkjet recording apparatus 1 according to the present embodiment.
The control unit 500 of the inkjet recording apparatus 1 of the present embodiment includes a CPU 501 that controls the entire apparatus, a program executed by the CPU 501, a ROM 502 that stores other fixed data, and a RAM 503 that temporarily stores image data and the like. A main controller 500A is provided. The control unit 500 also controls the host interface (I / F) 506 that controls data transfer with a host (information processing apparatus) 600 such as a personal computer, and an image output control unit that drives and controls the liquid ejection heads 4a and 4b. 511, an encoder analysis unit 512, and the like. The encoder analysis unit 512 inputs and analyzes detection signals from the main scanning encoder sensor 24 and the sub-scanning encoder sensor 26. The control unit 500 also includes a main scanning motor driving unit 513 that drives the main scanning motor 5, a sub scanning motor driving unit 514 that drives the sub scanning motor 16, and an input / output unit (I / O) between various sensors and actuators 517. O) 516 and the like are also provided.

  The image output control unit 511 is a data generation unit that generates print data, a drive waveform generation unit that generates a drive waveform for driving and controlling the liquid ejection heads 4a and 4b, and a required drive signal from the drive waveform. Data transfer means for transferring a head control signal and print data are included. Then, a drive waveform, a head control signal, print data, and the like are output to a head driver 510 which is a head drive circuit for driving the liquid discharge heads 4a and 4b mounted on the carriage 3, and the liquid discharge head 4a. , 4b, the ink is ejected according to the print data.

  The encoder analysis unit 512 includes a direction detection unit 520 that detects the movement direction from the detection signal, and a counter unit 521 that detects the movement amount. The control unit 500 controls the movement of the carriage 3 by controlling the driving of the main scanning motor 5 via the main scanning motor driving unit 513 based on the analysis result from the encoder analyzing unit 512. Further, the feeding control of the paper 10 is performed by controlling the driving of the sub-scanning motor 16 via the sub-scanning motor driving unit 514.

Next, caking that occurs due to precipitation of solid components in the ink will be described.
5 (a) is an explanatory view showing the distribution of the pigment component (solid component) I _G in the ink I immediately after stirring. 5 (b) is an explanatory view showing the distribution of the pigment component I _G in the ink I after leaving after stirring.
Pigment component in the ink, right after stirring it in a state of being uniformly distributed in the ink as shown in FIG. 5 (a), with time, larger pigment component I _G of gravity is gradually settled, As shown in FIG.5 (b), it settles and accumulates on the bottom of a container gradually, it hardens | cures, and caking is generated. In particular, caking is likely to occur when using an ink containing a pigment component having a large specific gravity, such as white ink or silver ink. If caking and pigment component I _G once solidified in the ink occurs, it is difficult to disperse in the ink of the packed pigment component I _G again I.

When such caking occurs in the liquid flow path in the liquid discharge heads 4a and 4b, the solid pigment component _IG is again removed even if the above-described maintenance and recovery operation such as idle discharge by the maintenance and recovery mechanisms 20 and 21 is performed. It cannot be dispersed in ink I. As a result, the proper ejection operation is hindered and cannot be eliminated, so that it is necessary to replace the liquid ejection heads 4a and 4b. Even if the ejection operation can be maintained, the content ratio of the pigment component of the ejected ink is uneven, resulting in unevenness of the formed image.

FIG. 6 is a schematic diagram showing a configuration of an ink supply mechanism 100 as a liquid supply apparatus of the present embodiment that supplies ink to the liquid discharge heads 4a and 4b.
The ink supply mechanism 100 according to the present embodiment is detachably attached with an ink cartridge 110 serving as an ejection liquid storage unit that stores the ink I. The ink I in the ink cartridge 110 is supplied to the liquid ejection heads 4 a and 4 b by the supply pump 101 through the supply passage 102. The ink I supplied to the liquid discharge heads 4a and 4b passes through the liquid flow paths in the liquid discharge heads 4a and 4b and is discharged from each nozzle.

  In the ink supply mechanism 100 of the present embodiment, a filter 103 for trapping foreign matter is provided in the supply passage 102. Accordingly, for example, caking occurs in the supply passage 102 upstream of the filter 103 in the ink conveyance direction, and even if the caking flows, the caking is trapped by the filter 103 and enters the liquid ejection heads 4a and 4b. There is nothing. Therefore, it is possible to prevent foreign matters such as caking from entering the liquid discharge heads 4a and 4b and causing discharge failure and head damage.

  In the ink supply mechanism 100 of this embodiment, a sub tank 105 is disposed in the supply passage 102 between the filter 103 and the liquid ejection heads 4a and 4b. The sub tank 105 temporarily stores the ink I supplied from the ink cartridge 110 through the supply passage 102, thereby realizing stable supply of the ink I to the liquid ejection heads 4a and 4b.

The control unit 500 of the present embodiment periodically performs an idle ejection operation (maintenance recovery operation) using the maintenance recovery mechanism 21 even during the non-image forming operation period. Thereby, the ink I in the liquid flow paths of the liquid discharge heads 4a and 4b is periodically discharged, and the ink I is supplied from the sub tank 105 to the liquid flow paths of the liquid discharge heads 4a and 4b through the supply passage 102. The As a result, the sub-tank 105, the supply passage 102, the liquid discharge head 4a, 4b ink I in the liquid flow path to flow in, thereby the pigment component I _G of the ink I is stirred in the ink I is dispersed, the pigment component occurrence of caking due to I _G settle is suppressed.

  Further, the ink supply mechanism 100 of the present embodiment is provided with a circulation passage 104 for circulating the ink I. A circulation electromagnetic valve 106 is provided upstream of the circulation passage 104 in the ink conveyance direction. In the example shown in FIG. 6, the ink I in the sub tank 105 returns to the supply passage 102 via the circulation passage 104. However, as shown in FIG. 7, the liquid discharge heads 4a and 4b are used. An example of a circulation path in which the ink I in the liquid flow path returns to the supply path 102 via the circulation path 104 ′ may be employed.

The control unit 500 according to the present embodiment opens the circulation electromagnetic valve 106 periodically (for example, every two hours) by the ink supply control unit 518 during the non-image forming operation period, thereby driving the supply pump 101 (see FIG. Maintenance and recovery operation) is executed. Thus, the ink I is supplied from the supply passage 102 to the sub tank 105, and the ink I in the sub tank 105 is returned to the supply passage 102 through the circulation passage 104, and the ink I circulates. Accordingly, the ink I flowing in the supply passage 102 and the sub tank 105, thereby the ink I is a pigment component I _G in the ink I is dispersed is stirred, the occurrence of caking due to pigment component I _G settle It is suppressed.

  Here, the above-described idle ejection operation and ink circulation operation cannot be appropriately executed in a state where the ink I in the ink cartridge 110 is out of the specified amount or less. Therefore, when the control unit 500 acquires through the I / O 516 that the ink remaining amount sensor has detected that the ink I of the ink cartridge 110 is less than the specified amount, the ink cartridge 110 is replaced and the ink in the ink cartridge 110 is replaced. Until I exceeds the specified amount, the idle ejection operation and the ink circulation operation are prohibited.

Accordingly, if the ink cartridge 110 is left out of ink after being out of ink, the time elapses without performing the idle ejection operation or the ink circulation operation. Thus, the supply passage 102, the sub tank 105, the liquid discharge head 4a, the liquid flow path of 4b, etc., precipitation of the pigment component I _G in the ink I is in progress, precipitate caking occurs solidified. In particular, when caking occurs in the liquid passages of the supply passage 102, the sub tank 105, and the liquid discharge heads 4a and 4b on the downstream side in the ink transport direction from the filter 103, the filter 103 cannot trap this and the caking does not occur in the liquid discharge head. It enters into 4a and 4b and causes ejection failure and head damage.

  If the user replaces the ink cartridge 110 with a new ink cartridge at an early stage after the ink cartridge 110 has run out of ink, caking does not occur. However, during a long holiday that the user cannot replace even if the ink runs out, the ink cartridge 110 may be left as it is after the ink runs out, causing caking.

  Therefore, in the present embodiment, apart from the ink I (ejection liquid) used for ejection, the alternative liquid S as a non-ejection liquid that has a lower solid component content than the ink I or does not contain a solid component. By supplying this instead of the ink I, it is possible to execute the idle ejection operation and the ink circulation operation even after the ink cartridge 110 is out of ink. The alternative liquid S may be any liquid that has a lower solid component content than the ink I or does not contain a solid component. For example, a liquid obtained by removing a solid component such as a pigment component from the ink I can be used.

  More specifically, the ink supply mechanism 100 of the present embodiment is detachably mounted with a replacement liquid cartridge 120 as a non-ejection liquid storage section that stores the replacement liquid S described above. The supply passage 102 of the ink supply mechanism 100 has a flow path switching valve 121 as a path switching means for switching between a first path 102A connected to the ink cartridge 110 and a second path 102B connected to the alternative liquid cartridge 120. Is provided. The alternative liquid S in the alternative liquid cartridge 120 is switched to the second passage 102 </ b> B by the flow path switching valve 121, and is supplied by the supply pump 101 to the sub tank 105 and the liquid discharge heads 4 a and 4 b through the supply passage 102.

  In this embodiment, the alternative liquid cartridge 120 is connected to the supply passage 102. However, the alternative liquid cartridge 120 is connected to the sub tank 105 without passing through the supply passage 102, or the alternative liquid cartridge 120 is connected to the supply passage 102. For example, a configuration in which the liquid ejection heads 4a and 4b are connected without using the sub-tank 105 or the sub tank 105 may be employed.

  In the present embodiment, when the ink remaining amount sensor detects that the remaining amount of the ink I in the ink cartridge 110 is equal to or less than the specified amount, the ink cartridge 110 is replaced and the ink I in the ink cartridge 110 is specified. Until the amount is exceeded, the flow path switching valve 121 switches to the second passage 102B. As a result, the alternative liquid S in the alternative liquid cartridge 120 can be supplied to the sub tank 105 and the liquid discharge heads 4 a and 4 b through the supply passage 102. As a result, it is possible to appropriately execute the idle ejection operation and the ink circulation operation even if the ink I from the ink cartridge 110 is not supplied.

  As the ink remaining amount sensor for detecting that the remaining amount of the ink I in the ink cartridge 110 is equal to or less than the specified amount, a well-known sensor can be widely used. For example, as in this embodiment, an ink remaining amount sensor that detects the ink remaining amount in the ink cartridge 110 from the result of detecting the amount of liquid in the sub tank 105 as shown in FIGS. 6 and 7 may be used. The ink remaining amount sensor of the present embodiment employs a filler detection method in which the photosensor 108 detects the filler 107 that is displaced according to the amount of liquid in the sub tank 105. Further, for example, a soft count type ink remaining amount sensor that detects the ink remaining amount in the ink cartridge 110 from the result of counting the ink consumption operation amount such as the image forming operation and the idle ejection operation may be used.

  Further, in the present embodiment, as the path switching means for switching between the first path 102A connected to the ink cartridge 110 and the second path 102B connected to the alternative liquid cartridge 120, a flow path as shown in FIGS. Although the switching valve 121 is adopted, it is not limited to this. For example, as shown in FIG. 8, an electromagnetic valve 122 arranged in the second passage 102B may be employed.

  In this embodiment, a removable cartridge type replacement liquid cartridge 120 is used as the non-ejection liquid storage section. For example, a fixed type replacement liquid tank 125 as shown in FIG. Also good. In this case, as shown in FIG. 9, the alternative liquid tank 125 is a replenishment type tank that can be supplemented with the alternative liquid S by providing an alternative liquid replenishment port 124 so that the alternative liquid S can be replenished therein. Is preferred. Further, in the case of a replenishing tank, foreign matter may be mixed in when the replacement liquid S is replenished, so that the foreign matter is prevented from flowing into the supply passage 102 and clogging the liquid discharge heads 4a and 4b. In addition, it is preferable to provide a filter 123 as shown in FIG.

FIG. 10 is a timing chart showing an example of the maintenance / recovery operation (idle ejection operation or circulation operation) during the non-image forming operation period in the present embodiment.
In the present embodiment, when the idle ejection operation is performed, the control unit 500 is in a state where the remaining amount of ink in the ink cartridge 110 exceeds the specified amount (there is a remaining amount) based on the detection result from the remaining ink sensor. When the determination is made, as shown in FIG. 10, the supply pump 101 is driven (time A) while the flow path switching valve 121 is switched to the ink side (first passage 102A). At this time, the controller 500 closes the circulation electromagnetic valve 106 of the circulation passage 104 (CLOSE) so that the ink I in the sub tank 105 does not flow out to the circulation passage 104. By such control, the ink I is supplied from the ink cartridge 110 to the liquid discharge heads 4a and 4b via the sub tank 105, and the idle discharge operation is appropriately performed.

  Further, when the circulation operation is performed in the present embodiment, the control unit 500 is in a state where the ink remaining amount in the ink cartridge 110 exceeds the specified amount (there is a remaining amount) based on the detection result from the ink remaining amount sensor. 10, the supply pump 101 is driven (time B) while the flow path switching valve 121 is switched to the ink side (first passage 102A) as shown in FIG. At this time, the controller 500 sets the circulation electromagnetic valve 106 of the circulation passage 104 to an open state (OPEN). By such control, the ink I is supplied from the ink cartridge 110 to the sub tank 105, and the ink I flows from the sub tank 105 to the circulation passage 104, so that the ink I is appropriately circulated.

  On the other hand, when it is determined from the detection result from the ink remaining amount sensor that the remaining amount of ink in the ink cartridge 110 has become equal to or less than the specified amount (no remaining amount), the control unit 500 performs FIG. As shown, the flow path switching valve 121 is switched to the alternative liquid side (second passage 102B), the circulation electromagnetic valve 106 of the circulation passage 104 is closed (CLOSE), and the supply pump 101 is driven. If it is determined that the remaining ink amount is equal to or less than the specified amount (no remaining amount) during the idle ejection operation as indicated by time C, the flow path switching valve 121 is operated while the supply pump 101 is driven. Switch to the alternative liquid side (second passage 102B). In addition, as shown at time E, when the idle discharge operation is performed with the flow path switching valve 121 switched to the alternative liquid side (second passage 102B), it is only necessary to drive the supply pump 101. . When the alternative liquid S is supplied from the alternative liquid cartridge 120 by such control, the ink I, the alternative liquid S, or a mixed liquid in which these are mixed is supplied to the liquid ejection heads 4a and 4b. The discharge operation is appropriately performed.

  Moreover, when the alternative liquid S is supplied from the alternative liquid cartridge 120 by such control, the alternative liquid S in the alternative liquid cartridge 120 gradually decreases as shown in FIGS. The ink I in the liquid discharge heads 4a and 4b is gradually replaced with the alternative liquid S, and the amount of the ink I is relatively reduced. As a result, the content ratio of the solid components in the sub tank 105 and the liquid discharge heads 4a and 4b is reduced, so that caking is unlikely to occur.

  Accordingly, after the idle discharge operation is performed while supplying the alternative liquid S from the alternative liquid cartridge 120, that is, after the flow path switching valve 121 is switched to the alternative liquid side (second passage 102B), Even if the time interval for performing the idle discharge operation is extended, the occurrence of defects due to caking can be suppressed. Therefore, after the flow path switching valve 121 is switched to the alternative liquid side (second passage 102B), the time interval for performing the idle discharge operation may be increased. However, if the configuration is such that the idle ejection operation is performed simultaneously for all color inks, even if the idle ejection operation in which the alternative liquid S is supplied for any one of the inks is performed, In some cases, an empty ejection operation in which normal ink I is supplied may be performed. In such a case, it should be noted that if the time interval for performing the idle ejection operation is widened, caking may occur for the other ink.

  Further, when it is determined from the detection result from the ink remaining amount sensor that the remaining amount of ink in the ink cartridge 110 has become equal to or less than the specified amount (no remaining amount), the control unit 500 determines the execution timing (time D) of the circulation operation. Even if it arrives, the circulation operation is not performed in this embodiment. That is, the control unit 500 closes the circulation electromagnetic valve 106 in the circulation passage 104 (CLOSE) and does not drive the supply pump 101. The reason is as follows.

  When the replacement liquid S is supplied from the replacement liquid cartridge 120 as in the present embodiment and then the ink cartridge 110 is replaced and the ink I in the ink cartridge 110 recovers to a state exceeding the specified amount, the ink I and the replacement liquid It is necessary to prevent the mixed liquid containing S from being discharged during the subsequent image forming operation and contributing to image formation. Therefore, after the ink I in the ink cartridge 110 recovers to a state exceeding the specified amount, an ink replacement operation is required to replace all the liquid in the portion where the mixed liquid may exist with the ink I in the ink cartridge 110. Become. Therefore, when the circulation operation is performed using the alternative liquid S from the alternative liquid cartridge 120 during the non-image forming operation period, mixed liquid exists in the circulation path 104, and the liquid in the circulation path 104 is also present in the ink replacement operation. It is necessary to replace with the ink I in the ink cartridge 110, resulting in a long ink replacement operation and an increase in ink consumption.

On the other hand, if not performed circulation operation in the non-image forming operation period, caking but pigment component I _G of the ink I in the circulation passage 104 there is a possibility that caking and settling occurs, generated in the circulation path 104 Since it is trapped by the filter 103 on the upstream side in the ink transport direction of the sub tank 105, it does not enter the liquid ejection heads 4a and 4b, and does not cause ejection failure or head damage.

  Of course, in order to suppress the occurrence of caking in the circulation passage 104, even if it is determined from the detection result from the ink remaining amount sensor that the ink remaining amount in the ink cartridge 110 is equal to or less than the specified amount (no remaining amount), the circulation An operation may be performed. In this case, the controller 500 switches the flow path switching valve 121 to the alternative liquid side (second passage 102B) and drives the supply pump 101 with the circulation electromagnetic valve 106 of the circulation passage 104 opened (OPEN). Let By such control, the alternative liquid S is supplied from the alternative liquid cartridge 120, whereby the ink I, the alternative liquid S, or a mixed liquid thereof is supplied to the sub tank 105 and the ink I and the alternative liquid S are supplied from the sub tank 105 to the circulation passage 104. The alternative liquid S or the mixed liquid flows, and the circulation operation of the ink I, the alternative liquid S, or the mixed liquid is appropriately performed.

  It is more important that the above-described idle ejection operation is performed during the non-image forming operation period than the circulation operation. If the idle ejection operation is not performed during the non-image forming operation period, the time elapses without the ink I flowing in the liquid ejection heads 4a and 4b and the sub tank 105, and the liquid ejection heads 4a and 4b and the sub tank 105 Caking occurs. The caking generated in this way enters the liquid discharge heads 4a and 4b, clogs the diaphragm filter section and the like, and may hinder the discharge operation. Since it is difficult to remove and restore the caking that has entered the liquid discharge heads 4a and 4b, the head needs to be replaced.

  After the replacement liquid S is supplied from the replacement liquid cartridge 120, when the ink cartridge 110 is replaced and the ink I in the ink cartridge 110 is restored to a state exceeding the specified amount (time F), the ink I and the replacement liquid S An ink replacement operation is performed to replace all the liquids at the places where the mixed liquid may exist with the ink I in the ink cartridge 110. Specifically, as shown in FIG. 10, the controller 500 switches the flow path switching valve 121 to the ink side (first path 102A), and closes the circulation electromagnetic valve 106 of the circulation path 104 (CLOSE). Then, the supply pump 101 is driven to perform the idle discharge operation, and the mixed liquid is discharged from the sub tank 105 and the liquid discharge heads 4a and 4b and replaced with the ink I.

[Modification 1]
Next, a modification of the ink supply mechanism 100 in the present embodiment (hereinafter, this modification is referred to as “modification 1”) will be described.
As described above, when the ink cartridge 110 is replaced after the replacement liquid S is supplied and the ink I in the ink cartridge 110 recovers to a state exceeding the specified amount, a mixed liquid in which the ink I and the replacement liquid S are mixed is obtained. An ink replacement operation is required to replace all the liquids that may be present with the ink I in the ink cartridge 110. For this reason, since it is desired to reduce the number of locations where the mixed liquid may be present as much as possible, the alternative liquid cartridge 120 is preferably connected to a location closer to the liquid ejection heads 4a and 4b.

FIG. 13 is a schematic diagram illustrating a configuration of the ink supply mechanism 100 according to the first modification.
In the first modification, as shown in FIG. 13, the alternative liquid tank 125 is also mounted on the carriage 3 on which the liquid discharge heads 4a and 4b are mounted. In the first modification, not the detachable substitute liquid cartridge 120 but the fixed substitute liquid tank 125 is an example, but the detachable substitute liquid cartridge 120 may be employed. According to the first modification, compared to the configuration in which the alternative liquid tank 125 is installed outside the carriage 3, it is easy to connect to a location closer to the liquid ejection heads 4 a and 4 b. In particular, the first modification employs a configuration in which the alternative liquid tank 125 is directly connected to the sub tank 105 without passing through the supply passage 102. Therefore, the alternative liquid S does not enter the supply passage 102, and only the sub tank 105 needs to be replaced with the ink I during the ink replacement operation.

  Even when the alternative liquid tank 125 is installed outside the carriage 3, the liquid discharge head 4 a, the supply path 102 for supplying the alternative liquid S from the alternative liquid tank 125 is provided separately from the supply path 102. It is possible to connect to a location closer to 4b. However, in this case, it is necessary to provide a supply path for the alternative liquid S in addition to the supply path 102, and a supply pump for conveying the alternative liquid S in the supply path may be separately prepared. Necessary and cost increases.

  Further, in the first modification, as shown in FIG. 13, the alternative liquid tank 125 is installed above the sub tank 105, and the alternative liquid passage in which the alternative liquid S in the alternative liquid tank 125 can be supplied to the sub tank 105 by the water head difference. 126 is provided. Thus, by controlling the electromagnetic valve 122 installed in the middle of the alternative liquid passage 126, the alternative liquid S in the alternative liquid tank 125 can be supplied to the sub tank 105 without using a driving means such as a pump. it can

14A to 14C are explanatory diagrams for explaining the capacity of the alternative liquid tank 125. FIG.
Immediately after the supply of the alternative liquid S from the alternative liquid tank 125 is started, as shown in FIG. 14A, the alternative liquid S in the alternative liquid tank 125 starts to decrease. As the alternative liquid S is supplied from the alternative liquid tank 125, the alternative liquid S in the alternative liquid tank 125 is decreased as shown in FIGS. The alternative liquid S increases, and eventually the alternative liquid remaining in the alternative liquid tank 125 disappears. When the alternative liquid remaining amount in the alternative liquid tank 125 is exhausted, the idle ejection operation cannot be performed as in the case where the ink remaining amount in the ink cartridge 110 is exhausted.

At this time, if the capacity of the alternative liquid tank 125 is less than the amount required to fill the liquid flow path in the liquid discharge heads 4a and 4b from the alternative liquid tank 125 through the sub tank 105 with the alternative liquid S, the alternative liquid tank 125 When the alternative liquid remaining in the liquid tank 125 is exhausted, the liquid flow paths in the sub tank 105 and the liquid ejection heads 4a and 4b cannot be completely filled with the alternative liquid S, and the ink I remains. In this case, alternative solutions idle discharge operation after the alternate solution remaining is exhausted the tank 125 that has passed without the time not implemented, the pigment component (solid component) in the ink I remaining generating caking and I _G is precipitated There is a risk of causing.

  Therefore, in the first modification, the capacity of the alternative liquid tank 125 is an amount required for filling the liquid flow path in the liquid discharge heads 4a and 4b from the alternative liquid tank 125 through the sub tank 105 with the alternative liquid S. It is comprised so that it may become the above. Thereby, before the alternative liquid remaining in the alternative liquid tank 125 runs out, it is possible to completely fill the liquid flow paths in the sub tank 105 and the liquid discharge heads 4a and 4b with the alternative liquid S and eliminate the remaining ink I. Become. Therefore, it is possible to suppress the occurrence of caking even if time passes without the idle discharge operation being performed after the alternative liquid remaining in the alternative liquid tank 125 is exhausted.

[Modification 2]
Next, a modified example of the control of the ink supply mechanism 100 in the present embodiment (hereinafter, this modified example is referred to as “modified example 2”) will be described.
In the above-described embodiment, when the remaining amount sensor of the ink cartridge 110 detects that the remaining amount of the ink I in the ink cartridge 110 is equal to or less than the predetermined amount, the flow path switching is performed at the timing of performing the first empty ejection operation thereafter. The valve 121 is switched to the second passage 102B, and the idle discharge operation is performed while supplying the alternative liquid S in the alternative liquid cartridge 120. However, caking does not occur immediately without performing the idle discharge operation, and there is some time before the caking occurs. Further, once the idle discharge operation is performed while supplying the alternative liquid S in the alternative liquid cartridge 120, it is necessary to perform the ink replacement operation after replacing the ink cartridge 110 as described above. Therefore, from the viewpoint of ink consumption due to the ink replacement operation and the occurrence of downtime, during the period when there is time before caking occurs, even if the execution timing of the idle ejection operation arrives, It is preferable not to supply the alternative liquid S.

FIG. 15 is a flowchart showing the flow of control when the execution timing of the idle ejection operation in Modification 2 has arrived.
The control unit 500 first determines the remaining amount of ink I in the ink cartridge 110 from the detection result of the remaining ink amount sensor every time the execution timing of the regular idle ejection operation arrives during the non-image forming operation period. It is determined whether or not the amount is exceeded (there is a remaining amount) (S1). If it is determined that there is a remaining amount in this determination (Yes in S1), the control unit 500 performs the idle ejection operation while supplying the ink I in the ink cartridge 110 as usual (S2).

  On the other hand, when it is determined that there is no remaining amount (No in S1), the controller 500 next determines whether or not the flow path switching valve 121 is on the ink side (whether or not it is switched to the first passage 102A). 'S3). When it is determined that the ink side is determined in this determination (Yes in S3), the control unit 500 does not perform the idle ejection operation. Then, the controller 500 reads the number n of idle ejection operation errors stored in the RAM 503 or the like (S4), counts up the number n of idle ejection operation errors (n = n + 1), and stores it (S5).

  Further, the control unit 500 determines whether or not the number of idle ejection operation errors n after the count-up exceeds the specified number a (S6), and until the number of idle ejection operation errors n exceeds the specified number of times a, the idle ejection is performed. No action is taken. If it is determined that the number of idle ejection operation errors n has exceeded the specified number of times a (Yes in S6), the control unit 500 switches the flow path switching valve 121 from the ink side to the alternative liquid side (second passage 102B) (S7). Then, the number n of idle ejection operation errors is reset to zero (S8). Thereby, when the execution timing of the idle discharge operation comes next time, the controller 500 determines that the flow path switching valve 121 is on the alternative liquid side (No in S3). As a result, the controller 500 performs the idle discharge operation while supplying the alternative liquid S in the alternative liquid cartridge 120 (S2).

Next, an example of the liquid discharge unit in the present embodiment will be described.
FIG. 16 is an explanatory plan view of an essential part showing an example of a liquid discharge unit.
The liquid ejection unit includes a casing portion composed of side plates 491A and 491B and a back plate 491C among members constituting a device for ejecting liquid such as an inkjet recording apparatus, a main scanning movement mechanism 493, and a carriage. 403 and a liquid discharge head 404. A liquid discharge unit in which at least a part of the ink supply mechanism 100 described above is further attached to, for example, the side plate 491B of the liquid discharge unit can be configured.

Next, another example of the liquid discharge unit in the present embodiment will be described.
FIG. 17 is an explanatory front view showing another example of the liquid discharge unit.
This liquid discharge unit includes a liquid discharge head 404 to which a flow path component 444 is attached, and a tube 456 connected to the flow path component 444. The flow path component 444 is disposed inside the cover 442. In addition, a connector 443 that is electrically connected to the liquid ejection head 404 is provided above the flow path component 444. This liquid ejection unit can also be configured as a liquid ejection unit to which at least a part of the ink supply mechanism 100 described above is further attached.

  In this specification, “an apparatus that discharges liquid” is an apparatus that includes a liquid discharge head or a liquid discharge unit and drives the liquid discharge head to discharge liquid. The apparatus for ejecting liquid includes not only an apparatus capable of ejecting liquid to an object to which liquid can adhere, but also an apparatus for ejecting liquid toward the air or liquid.

  This “apparatus for discharging liquid” may include means for feeding, transporting, and discharging a liquid to which liquid can adhere, as well as a pre-processing apparatus and a post-processing apparatus.

  For example, as a “liquid ejecting device”, an image forming device that forms an image on paper by ejecting ink, a powder is formed in layers to form a three-dimensional model (three-dimensional model) There is a three-dimensional modeling apparatus (three-dimensional modeling apparatus) that discharges a modeling liquid onto the powder layer.

  Further, the “apparatus for ejecting liquid” is not limited to an apparatus in which significant images such as characters and figures are visualized by the ejected liquid. For example, what forms a pattern etc. which does not have a meaning in itself, and what forms a three-dimensional image are also included.

  The above-mentioned “thing to which liquid can adhere” means that liquid can adhere at least temporarily, and adheres and adheres, or adheres and penetrates. Specific examples include recording media such as paper, recording paper, recording paper, film, and cloth, electronic parts such as electronic substrates and piezoelectric elements, powder layers (powder layers), organ models, and test cells. Yes, unless specifically limited, includes everything that the liquid adheres to.

  As the material of the above-mentioned “material to which liquid can adhere”, liquid such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, building materials such as wallpaper and flooring, textiles for clothing, etc. However, it only needs to be attached.

  In addition, “liquid” includes ink, processing liquid, DNA sample, resist, pattern material, binder, modeling liquid, or a solution and dispersion containing amino acid, protein, calcium, and the like.

  In addition, the “device for ejecting liquid” includes a device in which the liquid ejection head and the device to which the liquid can adhere move relatively, but is not limited thereto. Specific examples include a serial type apparatus that moves the liquid discharge head, a line type apparatus that does not move the liquid discharge head, and the like.

  In addition to the “device for discharging liquid”, a processing liquid coating apparatus for discharging a processing liquid onto a sheet for applying a processing liquid to the surface of the sheet for the purpose of modifying the surface of the sheet, or a raw material There is an injection granulator for granulating raw material fine particles by spraying a composition liquid dispersed in a solution through a nozzle.

  A “liquid ejection unit” is a unit in which functional parts and mechanisms are integrated with a liquid ejection head, and is an assembly of parts related to liquid ejection. For example, the “liquid discharge unit” includes a combination of at least one of a head tank, a carriage, a supply mechanism, a maintenance / recovery mechanism, and a main scanning movement mechanism with a liquid discharge head.

  Here, the term “integrated” refers to, for example, a liquid discharge head, a functional component, and a mechanism that are fixed to each other by fastening, adhesion, engagement, etc., and one that is held movably with respect to the other. Including. Further, the liquid discharge head, the functional component, and the mechanism may be configured to be detachable from each other.

  For example, there is a liquid discharge unit in which a liquid discharge head and a head tank are integrated. Also, there are some in which the liquid discharge head and the head tank are integrated by being connected to each other by a tube or the like. Here, a unit including a filter may be added between the head tank and the liquid discharge head of these liquid discharge units.

  In addition, there is a liquid discharge unit in which a liquid discharge head and a carriage are integrated.

  In addition, there is a liquid discharge unit in which the liquid discharge head and the scanning movement mechanism are integrated by holding the liquid discharge head movably on a guide member that constitutes a part of the scanning movement mechanism. Also, as shown in FIG. 16, there is a liquid discharge unit in which a liquid discharge head, a carriage, and a main scanning movement mechanism are integrated.

  Also, there is a liquid discharge unit in which a cap member that is a part of the maintenance / recovery mechanism is fixed to a carriage to which the liquid discharge head is attached, and the liquid discharge head, the carriage, and the maintenance / recovery mechanism are integrated. .

In addition, as shown in FIG. 17, as a liquid discharge unit, a tube is connected to a liquid discharge head to which a head tank or a flow path component is attached, and the liquid discharge head and a supply mechanism are integrated. .

  The main scanning movement mechanism includes a guide member alone. The supply mechanism includes a single tube and a single loading unit.

  In addition, the terms “image formation”, “recording”, “printing”, “printing”, “printing”, “modeling” and the like in the terms of the present application are all synonymous.

What was demonstrated above is an example, and there exists an effect peculiar for every following aspect.
(Aspect A)
Pigment component I _G such liquid discharge head 4a the ejection liquid ink I like containing solid component from the ejection liquid storage portion such as an ink cartridge 110 through the supply passage 102 of the feed pump for supplying the liquid flow path in 4b In the liquid supply apparatus such as the ink supply mechanism 100 including the discharge liquid supply unit 101 or the like, when the remaining amount of the discharge liquid in the discharge liquid storage unit is equal to or less than a predetermined amount, the liquid supply device is more than the discharge liquid. The liquid flow in the liquid discharge head from the non-discharge liquid storage portion such as the alternative liquid cartridge 120 or the alternative liquid tank 125 from the non-discharge liquid such as the alternative liquid S having a low solid component content or no solid component. It has a non-ejection liquid supply means such as a flow path switching valve 121 and an electromagnetic valve 122 for supplying to the path.
According to this aspect, when the remaining amount of the discharge liquid in the discharge liquid storage part is equal to or less than the specified amount, the non-discharge liquid from the non-discharge liquid storage part is supplied to the liquid discharge head by the non-discharge liquid supply unit. It is supplied to the liquid flow path inside. As a result, even when the discharge liquid in the discharge liquid storage section is insufficient, the discharge liquid in the liquid discharge head is caused to flow by supplying the non-discharge liquid to the liquid flow path in the liquid discharge head. Is possible. Therefore, it is possible to suppress the occurrence of caking due to the precipitation of solid components in the discharge liquid in the liquid discharge head.
Further, the non-ejection liquid supplied to the liquid flow path in the liquid ejection head has a lower solid component content than the ejection liquid or does not contain a solid component. The solid component content in can be reduced. As a result, the subsequent precipitation of the solid component is reduced, the increase in the amount of precipitation in the liquid discharge head can be delayed, and the occurrence of caking in the liquid discharge head is suppressed.
Note that the “non-ejection liquid” here means another liquid that is not the “ejection liquid” and is a liquid that has a lower solid component content than the ejection liquid or does not contain a solid component. , Including liquid that may be discharged.

(Aspect B)
In the aspect A, the non-ejection liquid supply means supplies the non-ejection liquid to the liquid channel in the liquid ejection head through the supply passage 102.
According to this, since the non-discharge liquid is also supplied into the supply passage, the discharge liquid in the supply passage can be made to flow, and the solid component in the discharge liquid is precipitated in the supply passage. It is possible to suppress the occurrence of caking.

(Aspect C)
In the aspect B, the supply passage 102 includes a flow path switching valve 121 that switches between a first passage 102A connected to the discharge liquid storage portion and a second passage 102B connected to the non-discharge liquid storage portion. The non-ejection liquid supply unit is configured to switch the non-ejection liquid in the liquid ejection head by switching the first passage to the second passage by the passage switching unit. It supplies to the said liquid flow path.
According to this, the non-ejection liquid in the non-ejection liquid reservoir can be supplied from the supply passage to the liquid passage in the liquid ejection head with a simple configuration.

(Aspect D)
In any one of the aspects A to C, the liquid discharge head includes a circulation passage 104 that enables circulation of the liquid in the liquid flow path of the liquid discharge head or the liquid in the supply passage.
According to this, the liquid in the liquid flow path and the supply path of the liquid discharge head can be flowed without consuming the discharge liquid, so that the precipitation of solid components can be suppressed and the occurrence of caking can be suppressed.

(Aspect E)
In the aspect D, there is an inflow prohibiting means such as a circulation electromagnetic valve 106 that prohibits the inflow of liquid into the circulation passage 104, and the non-ejection liquid supply means is in a state prohibited by the inflow prohibiting means, A discharge liquid is supplied to the liquid flow path in the liquid discharge head.
After the non-ejection liquid is supplied from the non-ejection liquid reservoir, the ejection liquid reservoir is replaced and the ejection liquid in the non-ejection liquid reservoir is restored to a state exceeding the specified amount. It is necessary to perform a replacement operation in which all the liquids in the place where there is a possibility that the mixed liquid in which the liquid and the non-discharge liquid are mixed are replaced with the discharge liquid in the discharge liquid storage unit. Therefore, when the non-ejection liquid is supplied from the non-ejection liquid reservoir, the mixed liquid is also present in the circulation passage 104 if the non-ejection liquid flows into the circulation passage 104. Therefore, in the replacement operation, it is necessary to replace the liquid in the circulation passage 104 with the discharge liquid in the discharge liquid storage unit, resulting in a long ink replacement operation and an increase in ink consumption.
According to this aspect, even if the non-ejection liquid is supplied from the non-ejection liquid reservoir, the non-ejection liquid does not flow into the circulation passage 104, so that the circulation passage 104 is in the ejection liquid reservoir during the replacement operation. Thus, it is not necessary to replace the liquid with a discharge liquid, and it is possible to reduce the time for the ink replacement operation and to suppress the ink consumption.

(Aspect F)
In any one of the aspects A to E, the non-ejection liquid supply unit may be configured to perform a liquid flow of the liquid ejection head after the remaining amount of the ejection liquid in the ejection liquid storage unit becomes a predetermined amount or less. The non-ejection liquid is supplied to a liquid channel in the liquid ejection head when an execution error of a maintenance recovery operation such as an idle ejection operation for causing the ejection liquid in the passage to flow has reached a predetermined number of times. And
Even if the maintenance recovery operation cannot be performed after the remaining amount of the discharge liquid in the discharge liquid storage section has fallen below the specified amount, caking does not occur immediately, and some time is required until caking occurs. There is time to spare. Further, once the maintenance and recovery operation is performed while supplying the non-ejection liquid in the non-ejection liquid reservoir, the replacement operation needs to be performed after the ejection liquid reservoir is replaced as described above. Therefore, in consideration of consumption of discharge liquid due to replacement operation and occurrence of downtime, even if there is a time allowance before caking occurs, even if the timing for performing the maintenance recovery operation arrives, It is preferable not to supply the non-ejection liquid in the liquid reservoir.
According to this aspect, after the remaining amount of the discharge liquid in the discharge liquid storage unit becomes equal to or less than the specified amount, the non-discharge in the non-discharge liquid storage unit is continued until the execution error of the maintenance recovery operation reaches the specified number of times. The working liquid is not supplied. Therefore, by appropriately setting the specified number of times, if the discharge liquid reservoir is replaced during the period until the specified number of times is reached, the consumption of the discharging liquid and the downtime due to the replacement operation are avoided without causing caking. Can be prevented.

(Aspect G)
In any of the above aspects A to F, the capacity of the non-ejection liquid reservoir is required to fill at least the non-ejection liquid reservoir to the liquid flow path of the liquid ejection head with the non-ejection liquid. It is more than quantity.
If the capacity of the non-ejection liquid reservoir is less than the amount required to fill the non-ejection liquid reservoir to the liquid flow path of the liquid ejection head with the non-ejection liquid, the non-ejection liquid reservoir When the discharge liquid is exhausted, the non-discharge liquid storage part to the liquid flow path of the liquid discharge head cannot be completely filled with the non-discharge liquid, and the discharge liquid remains. In this case, there is a possibility that the solid component in the remaining discharge liquid may precipitate and cause caking by the passage of time without performing the maintenance recovery operation after the non-discharge liquid in the non-discharge liquid storage portion is exhausted. is there.
According to this aspect, before the non-ejection liquid in the non-ejection liquid reservoir disappears, the non-ejection liquid reservoir to the liquid flow path of the liquid ejection head is filled with the non-ejection liquid, and the ejection liquid remains. Can be eliminated. Therefore, even if the maintenance recovery operation is not performed after the non-ejection liquid in the non-ejection liquid storage portion is exhausted, the occurrence of caking is suppressed.

(Aspect H)
A liquid discharge head 4a for discharging the discharge liquid ink I like containing solid components such as a pigment component I _G from the discharge port of the nozzle or the like connected to the liquid flow path received in the liquid flow path, and 4b, An ink supply mechanism 100 including discharge liquid supply means such as a supply pump 101 that supplies the discharge liquid from a discharge liquid storage section such as the ink cartridge 110 to the liquid flow path in the liquid discharge head through the supply passage 102. In an apparatus for ejecting liquid, such as an ink jet recording apparatus having a liquid supply apparatus such as the liquid supply apparatus, the liquid supply apparatus according to any one of the aspects A to G is used as the liquid supply apparatus.
According to this aspect, it is possible to suppress the occurrence of caking due to precipitation of solid components in the liquid for discharge in the liquid discharge head, and it is possible to suppress a situation in which discharge failure or head breakage due to caking is caused.

(Aspect I)
In the aspect H, the liquid discharge head is mounted, and has a moving unit such as a carriage 3 that moves in a direction orthogonal to the liquid discharge direction of the liquid discharge head. It is mounted on the moving means.
According to this aspect, it is easier to connect the non-ejection liquid reservoir to a location closer to the liquid ejection head, compared to a configuration in which the non-ejection liquid reservoir is installed outside the moving means. As described above, once the maintenance and recovery operation is performed while supplying the non-ejection liquid in the non-ejection liquid reservoir, the replacement operation needs to be performed after the ejection liquid reservoir is replaced. Consumption of discharge liquid due to operation, occurrence of downtime, and the like become problems. By connecting the non-ejection liquid reservoir to a location closer to the liquid ejection head, the number of locations where replacement is required can be reduced, and the consumption of ejection liquid and the occurrence of downtime due to the replacement operation can be suppressed.
Even when the non-ejection liquid reservoir is installed outside the moving means, a location closer to the liquid ejection head is provided by providing a channel for supplying the non-ejection liquid reservoir separately from the supply channel 102. It is possible to connect a non-ejection liquid storage part to. However, in this case, in addition to the necessity of providing a passage different from the supply passage 102, it is also necessary to separately prepare driving means such as a supply pump for conveying the non-ejection liquid in the passage. The cost is likely to rise.

(Aspect J)
In the aspect H or I, the maintenance / recovery operation of the maintenance / recovery mechanisms 20, 21, etc. that performs the maintenance / recovery operation such as the idle ejection operation for causing the ejection liquid in the liquid flow path of the liquid ejection head to flow A non-ejection liquid supply means that supplies the non-ejection liquid from the non-ejection liquid reservoir to the liquid flow path in the liquid ejection head, and maintains the maintenance within a predetermined period. The time interval for the recovery operation executing means to execute the maintenance recovery operation is wide.
When the non-ejection liquid is supplied from the non-ejection liquid reservoir, the ejection liquid in the liquid ejection heads 4a and 4b is gradually replaced with the non-ejection liquid, and the amount of the ejection liquid is relatively reduced. Since the solid component content in the discharge heads 4a and 4b is reduced, caking is unlikely to occur. Therefore, after the maintenance / recovery operation is performed while supplying the non-ejection liquid from the non-ejection liquid reservoir, the occurrence of defects due to caking is suppressed even if the time interval for performing the maintenance / recovery operation is extended. it can.

DESCRIPTION OF SYMBOLS 1 Inkjet recording device 3 Carriage 4a, 4b Liquid discharge head 10 Paper 20, 21 Maintenance recovery mechanism 51 Conveyance mechanism 100 Ink supply mechanism 101 Supply pump 102 Supply path 102A First path 102B Second path 103 Filter 104 Circulation path 105 Sub tank 106 Circulation Solenoid valve 107 Filler 108 Photo sensor 110 Ink cartridge 120 Alternative liquid cartridge 121 Flow path switching valve 122 Electromagnetic valve 123 Filter 124 Alternative liquid replenishment port 125 Alternative liquid tank 126 Alternative liquid path

Japanese Patent No. 3384380

Claims (10)

In a liquid supply apparatus comprising a discharge liquid supply means for supplying a discharge liquid containing a solid component from a discharge liquid reservoir to a liquid flow path in a liquid discharge head through a supply passage,
When the remaining amount of the discharge liquid in the discharge liquid reservoir is equal to or less than a specified amount, the non-discharge liquid is a non-discharge liquid that has a lower solid component content than the discharge liquid or does not contain a solid component. A liquid supply apparatus comprising: a non-discharge liquid supply means for supplying the liquid flow path in the liquid discharge head from a reservoir. The liquid supply apparatus according to claim 1,
The non-ejection liquid supply means supplies the non-ejection liquid to the liquid flow path in the liquid ejection head through the supply passage. The liquid supply apparatus according to claim 2, wherein
The supply passage is provided with passage switching means for switching between a first passage connected to the discharge liquid storage section and a second passage connected to the non-discharge liquid storage section,
The non-ejection liquid supply means supplies the non-ejection liquid to the liquid flow path in the liquid ejection head by switching from the first path to the second path by the path switching means. Liquid supply device. The liquid supply apparatus according to any one of claims 1 to 3,
A liquid supply apparatus comprising a circulation passage that enables circulation of the liquid in the liquid flow path of the liquid discharge head or the liquid in the supply passage. The liquid supply apparatus according to claim 4, wherein
An inflow prohibiting means for prohibiting the inflow of liquid into the circulation passage;
The non-ejection liquid supply means supplies the non-ejection liquid to the liquid channel in the liquid ejection head in a prohibited state by the inflow prohibition means. The liquid supply apparatus according to any one of claims 1 to 5,
The non-ejection liquid supply means maintains and recovers the ejection liquid in the liquid flow path of the liquid ejection head after the remaining amount of the ejection liquid in the ejection liquid storage section becomes a predetermined amount or less. A liquid supply apparatus that supplies the non-ejection liquid to a liquid flow path in the liquid ejection head when the execution error of the number of times reaches a predetermined number of times. The liquid supply apparatus according to any one of claims 1 to 6,
The capacity of the non-ejection liquid reservoir is equal to or greater than the amount required to fill at least the non-ejection liquid reservoir to the liquid flow path of the liquid ejection head with the non-ejection liquid. . A liquid discharge head for receiving a discharge liquid containing a solid component into the liquid flow path and discharging the liquid from a discharge port connected to the liquid flow path;
An apparatus for discharging a liquid, comprising: a liquid supply device provided with a discharge liquid supply means for supplying the discharge liquid from the discharge liquid reservoir to the liquid flow path in the liquid discharge head through a supply passage;
An apparatus for ejecting liquid, wherein the liquid supply apparatus according to claim 1 is used as the liquid supply apparatus. The apparatus for discharging a liquid according to claim 8,
The liquid discharge head is mounted, and has a moving means for moving in a direction orthogonal to the liquid discharge direction of the liquid discharge head,
The non-discharge liquid storage section is mounted on the moving means, and discharges liquid. The apparatus for discharging a liquid according to claim 8 or 9,
A maintenance / recovery operation executing means for executing a maintenance / recovery operation for causing the discharge liquid in the liquid flow path of the liquid discharge head to flow at a predetermined execution timing;
Within a predetermined period after the non-ejection liquid supply means supplies the non-ejection liquid from the non-ejection liquid reservoir to the liquid flow path in the liquid ejection head, the maintenance / recovery operation execution means An apparatus for ejecting liquid, characterized in that the time interval for performing the maintenance and recovery operation is wide.

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