Liquid ejection device

Abstract

To eliminate drying of liquid in a nozzle by ejecting an appropriate amount of the liquid from the nozzle before entering a standby state waiting for reception of a next ejection instruction signal in a capped state in which the nozzle is covered with a cap, after completion of ejection of the liquid to a medium to which the liquid is to be ejected.SOLUTION: When receiving a recording command, a cap is lowered to enter an uncapped state (S101), and recording on a recording paper is performed (S102). When a prescribed time has elapsed (S104) without reception of a next recording command (S103 :NO), pre-standby flushing is performed (S105), and thereafter, a capped state in which a plurality of nozzles is covered with caps is created, thereby entering a standby state waiting for reception of a next recording command in the capped state (S106). In the pre-standby flushing, ink is discharged in an amount according to pre-standby parameters related to a degree of drying of the ink in the nozzle immediately before ejection of the ink from the nozzle.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a liquid ejection device that ejects a liquid from a nozzle.

Background Art

[0002] As an example of a liquid ejection device that ejects a liquid from a nozzle, Patent Document 1 describes an inkjet printer that ejects ink from a nozzle. In the printer of Patent Document 1, a cap parameter corresponding to a cap evaporation rate, which is the evaporation rate of ink in a cap covering a plurality of nozzles of an inkjet head, is calculated. Then, based on the calculated cap parameter, the discharge amount of ink from the nozzle in pre-printing flushing or suction purge before printing is determined, whether to perform flushing and suction purge in regular maintenance is judged, and the discharge amount of ink is determined.

[0003] Further, in the printer of Patent Document 1, the cap evaporation rate and a nozzle evaporation rate, which is the evaporation rate of ink in the nozzle due to evaporation of moisture in the ink in the nozzle, are calculated. Then, when the cap evaporation rate and the nozzle evaporation rate satisfy predetermined conditions in a capping state where the nozzle is covered with a cap, flushing is performed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Here, in Patent Document 1, flushing and suction purge are performed before printing or during regular maintenance, or flushing is performed when the cap evaporation rate and the nozzle evaporation rate satisfy predetermined conditions after printing is completed and the capping state is achieved. However, in Patent Document 1, after printing is completed, until the standby state of waiting for the reception of the next printing command in the capped state is reached, the drying of the ink in the nozzle is not eliminated.

[0006] An object of the present invention is to discharge an appropriate amount of liquid from the nozzle to eliminate the drying of the liquid in the nozzle until the standby state of waiting for the reception of the next discharge instruction signal in the capped state where the nozzle is covered with a cap after the discharge of the liquid to the discharged medium is completed. It is to provide a liquid discharge device capable of doing so.

Means for Solving the Problems

[0007] The liquid discharge device of the present invention includes a liquid discharge head having nozzles, a cap covering the nozzles, a capped state in which the nozzles are covered with the cap, and an uncapped state in which the cap is separated from the liquid discharge head and the nozzles are exposed compared to the capped state. switching means for switching, and a control unit, wherein the liquid discharge head includes a nozzle row formed by arranging a plurality of the nozzles in one direction, a common flow path extending in the one direction and communicating with the plurality of nozzles forming the nozzle row, and a supply port for supplying liquid to the common flow path, and the control unit, when receiving a discharge instruction signal for instructing the discharge of liquid to the discharged medium, in the uncapped state, causes the liquid discharge head to perform a discharge operation of discharging liquid from the nozzles to the discharged medium, and after the completion of the discharge operation, controls the switching means to switch from the uncapped state to the capped state, thereby setting the standby state of waiting for the reception of the discharge instruction signal in the capped state, and after the completion of the discharge operation, until the standby state is reached, controls the liquid discharge head to perform pre-standby flushing for discharging liquid from the nozzles. In the pre-standby flushing, among the plurality of nozzles forming the nozzle row, the end nozzle farthest from the supply portLeu, Alternatively, from some of the nozzles that include the end nozzle and are arranged continuously in the one direction, an amount of liquid corresponding to a pre-wait parameter related to the degree of drying of the liquid in the nozzle immediately before the pre-wait flushing is discharged. After completion of the discharging operation, before the pre-wait flushing, pre-flushing is performed to discharge liquid from the nozzles among the plurality of nozzles forming the nozzle row that are closer to the supply port than the nozzle from which liquid is discharged in the pre-wait flushing. Further, the liquid ejection device of the present invention includes a liquid ejection head having nozzles, a cap that covers the nozzles, a cap state in which the nozzles are covered with the cap, and a switching means for switching between the cap state and an uncapped state in which the cap is separated from the liquid ejection head and the nozzles are exposed, and a control unit. , frontThe recording control unit selectively performs recording on the medium to be ejected in either a first recording mode or a second recording mode that performs recording with higher image quality than the first recording mode. When receiving a discharge instruction signal for instructing the discharge of liquid onto the medium to be ejected, in the uncapped state, it causes the liquid discharge head to perform a discharge operation of discharging liquid from the nozzle onto the medium to be ejected. After completion of the discharge operation, by controlling the switching means to switch from the uncapped state to the capped state, it enters a standby state of waiting for reception of the discharge instruction signal in the capped state. After completion of the discharge operation, until entering the standby state, it controls the liquid discharge head to perform pre-standby flushing of discharging liquid from the nozzle. In the pre-standby flushing, an amount of liquid corresponding to a pre-standby parameter related to the degree of drying of the liquid in the nozzle immediately before the pre-standby flushing is discharged from the nozzle. When, in the standby state, upon receiving the discharge instruction signal, recording on the medium to be ejected is to be performed in the second recording mode, the liquid discharge head is caused to perform another flushing of discharging an amount of liquid corresponding to a drying progress parameter related to the degree of progress of drying of the liquid in the nozzle in the capped state from the nozzle, and then the discharge operation is performed. When a predetermined pre-discharge skip condition for performing recording on the medium to be ejected in the first recording mode is satisfied, the liquid discharge head is caused to perform the discharge operation without performing the another flushing. Further, the liquid ejection device of the present invention includes a liquid ejection head having nozzles, a cap that covers the nozzles, a cap state in which the nozzles are covered by the cap, and a switching means that switches between the cap state and an uncapped state in which the cap is separated from the liquid ejection head and the nozzles are exposed, a temperature sensor that detects temperature, and a control unit. The control unit causes the liquid ejection head to perform a ejection operation of ejecting liquid from the nozzles to the medium to be ejected in the uncapped state when receiving an ejection instruction signal for instructing ejection of liquid to the medium to be ejected. After completion of the ejection operation, the control unit controls the switching means to switch from the uncapped state to the cap state, thereby setting a standby state in which reception of the ejection instruction signal is awaited in the cap state. After completion of the ejection operation and until the standby state is reached, the control unit controls the liquid ejection head to perform pre-standby flushing for discharging liquid from the nozzles. In the pre-standby flushing, an amount of liquid corresponding to a pre-standby parameter related to the degree of drying of the liquid in the nozzles immediately before the pre-standby flushing is discharged from the nozzles. When the ejection instruction signal is received in the standby state and the pre-ejection temperature condition related to the temperature detected by the temperature sensor immediately before the ejection operation is not satisfied, another flushing is performed in which an amount of liquid corresponding to a drying progress parameter related to the degree of progress of drying of the liquid in the nozzles in the cap state is discharged from the nozzles, and then the ejection operation is performed. When a predetermined pre-ejection skip condition including the pre-ejection temperature condition is satisfied, the liquid ejection head is caused to perform the ejection operation without performing the another flushing. Further, the liquid ejection device of the present invention includes a liquid ejection head having nozzles, a cap that covers the nozzles, a capped state in which the nozzles are covered by the cap, and an uncapped state in which the cap is separated from the liquid ejection head and the nozzles are exposed, which is more than the capped state, a switching means for switching between the two states, a humidity sensor for detecting humidity, and a control unit. When the control unit receives a discharge instruction signal for instructing the discharge of liquid onto a medium to be discharged, it causes the liquid ejection head to perform a discharge operation of discharging liquid from the nozzles onto the medium to be discharged in the uncapped state. After completion of the discharge operation, the control unit controls the switching means to switch from the uncapped state to the capped state, thereby putting the device in a standby state of waiting for the reception of the discharge instruction signal in the capped state. After completion of the discharge operation and until the standby state is reached, the control unit controls the liquid ejection head to perform pre-standby flushing for discharging liquid from the nozzles. In the pre-standby flushing, an amount of liquid corresponding to a pre-standby parameter related to the degree of drying of the liquid in the nozzles immediately before the pre-standby flushing is discharged from the nozzles. When the discharge instruction signal is received in the standby state and the pre-discharge humidity condition related to the humidity detected by the humidity sensor immediately before the discharge operation is not satisfied, the liquid ejection head is caused to perform another flushing for discharging an amount of liquid corresponding to a drying progress parameter related to the degree of progress of drying of the liquid in the nozzles in the capped state from the nozzles, and then the discharge operation is performed. When a predetermined pre-discharge skip condition including the pre-discharge humidity condition is satisfied, the liquid ejection head is caused to perform the discharge operation without performing the another flushing. Further, the liquid ejection device of the present invention includes a liquid ejection head having a plurality of nozzles, a cap that covers the nozzles, a capped state in which the nozzles are covered by the cap, and an uncapped state in which the cap is separated from the liquid ejection head and the nozzles are exposed, which is more than the capped state, a switching means for switching between the two states, and a control unit. , frontThe recording control unit selectively performs recording on the ejected medium in either a first recording mode or a second recording mode that performs recording with higher image quality than the first recording mode. When performing recording on the ejected medium in the second recording mode, compared to when performing recording on the ejected medium in the first recording mode, causing the liquid ejection head to eject liquid from the nozzle to the ejection target medium the number of nozzles used for the ejection operation is smaller. When receiving an ejection instruction signal for instructing ejection of liquid onto the ejected medium, in the uncapped state, vomiting the ejection operation is performed. After completion of the ejection operation, by controlling the switching means to switch from the uncapped state to the capped state, a standby state is set to wait for reception of the ejection instruction signal in the capped state. After completion of the ejection operation and until the standby state is reached, the liquid ejection head is controlled to perform pre-standby flushing to discharge liquid from the nozzles. In the pre-standby flushing, an amount of liquid corresponding to a pre-standby parameter related to the degree of drying of the liquid in the nozzle immediately before the pre-standby flushing is discharged from the nozzle. When performing recording on the ejected medium in the second recording mode, after completion of the ejection operation and until the standby state is reached, the liquid ejection head is made to perform the pre-standby flushing and another flushing to discharge an amount of liquid corresponding to a drying progress parameter related to the degree of progress of drying of the liquid in the nozzle in the capped state from the nozzle. When a predetermined post-ejection skip condition for performing recording on the ejected medium in the first recording mode is satisfied, after completion of the ejection operation and until the standby state is reached, the liquid ejection head is made to perform the pre-standby flushing and not perform the other flushing. Further, the liquid ejection device of the present invention includes a liquid ejection head having a nozzle, a cap that covers the nozzle, a cap state in which the nozzle is covered by the cap, and a switching unit that switches between the cap state and an uncapped state in which the cap is separated from the liquid ejection head and the nozzle is exposed, a temperature sensor that detects temperature, and a control unit. When the control unit receives a discharge instruction signal for instructing discharge of liquid onto a medium to be discharged, it causes the liquid ejection head to perform a discharge operation of discharging liquid from the nozzle onto the medium to be discharged in the uncapped state. After completion of the discharge operation, the control unit controls the switching unit to switch from the uncapped state to the cap state, thereby setting a standby state in which reception of the discharge instruction signal is awaited in the cap state. After completion of the discharge operation and until the standby state is reached, the liquid ejection head is controlled to perform pre-standby flushing for discharging liquid from the nozzle. In the pre-standby flushing, an amount of liquid corresponding to a pre-standby parameter related to the degree of drying of the liquid in the nozzle immediately before the pre-standby flushing is discharged from the nozzle. If the temperature condition during discharge, which is related to the temperature detected by the temperature sensor during the discharge operation, is not satisfied, then after completion of the discharge operation and until the standby state is reached, the liquid ejection head is caused to perform the pre-standby flushing and another flushing for discharging an amount of liquid corresponding to a drying progress parameter related to the degree of progress of drying of the liquid in the nozzle in the cap state from the nozzle. If a predetermined post-discharge skip condition including the temperature condition during discharge is satisfied, then after completion of the discharge operation and until the standby state is reached, the liquid ejection head is caused to perform the pre-standby flushing and not to perform the another flushing In addition, the liquid ejection device of the present invention includes a liquid ejection head having nozzles, a cap covering the nozzles, a cap state in which the nozzles are covered by the cap, and a switching means for switching between the cap state and an uncapped state in which the cap is separated from the liquid ejection head and the nozzles are exposed, a humidity sensor for detecting humidity, and a control unit. The control unit, when receiving a discharge instruction signal for instructing the discharge of liquid onto a medium to be discharged, causes the liquid ejection head to perform a discharge operation of discharging liquid from the nozzles onto the medium to be discharged in the uncapped state. After completion of the discharge operation, the control unit controls the switching means to switch from the uncapped state to the cap state, thereby setting a standby state in which reception of the discharge instruction signal is awaited in the cap state. After completion of the discharge operation and until the standby state is reached, the control unit controls the liquid ejection head to perform pre-standby flushing for discharging liquid from the nozzles. In the pre-standby flushing, an amount of liquid corresponding to a pre-standby parameter related to the degree of drying of the liquid in the nozzles immediately before the pre-standby flushing is discharged from the nozzles. If the humidity conditions during discharge, which are related to the humidity detected by the humidity sensor during the discharge operation, are not satisfied, after completion of the discharge operation and until the standby state is reached, the liquid ejection head is caused to perform the pre-standby flushing and another flushing for discharging an amount of liquid corresponding to a drying progress parameter related to the degree of progress of drying of the liquid in the nozzles in the cap state. If a predetermined post-discharge skip condition including the humidity conditions during discharge is satisfied, after completion of the discharge operation and until the standby state is reached, the liquid ejection head is caused to perform the pre-standby flushing and not to perform the other flushing Further, the liquid ejection device of the present invention includes a liquid ejection head having a nozzle, a cap that covers the nozzle, a cap state in which the nozzle is covered by the cap, and a switching unit that switches between the cap state and an uncapped state in which the cap is separated from the liquid ejection head and the nozzle is exposed, and a control unit. When the control unit receives a discharge instruction signal for instructing the discharge of liquid onto a medium to be discharged, it causes the liquid ejection head to perform a discharge operation of discharging liquid from the nozzle onto the medium to be discharged in the uncapped state. After completion of the discharge operation, by controlling the switching unit to switch from the uncapped state to the cap state, it is put into a standby state of waiting for reception of the discharge instruction signal in the cap state. After completion of the discharge operation, before reaching the standby state, the liquid ejection head is controlled to perform pre-standby flushing for discharging liquid from the nozzle. In the pre-standby flushing, an amount of liquid corresponding to a pre-standby parameter related to the degree of drying of the liquid in the nozzle immediately before the pre-standby flushing is discharged from the nozzle. After completion of the discharge operation, before reaching the standby state, the liquid ejection head is controlled to perform pre-standby flushing for discharging liquid from the nozzle. During the standby state, the liquid ejection head is not controlled to discharge liquid from the nozzle. When the discharge instruction signal is received in the standby state and a predetermined condition is satisfied, another flushing different from the pre-standby flushing is performed and then the discharge operation is performed. When the predetermined condition is not satisfied, the discharge operation is performed without performing the other flushing.

Advantages of the Invention

[0008] According to the present invention, by performing pre-standby flushing, it is possible to eliminate the drying of the nozzle before reaching the standby state after completion of the discharge operation. Further, in the pre-standby flushing, since an amount of liquid corresponding to the value of the pre-standby parameter related to the degree of drying of the nozzle immediately before the pre-standby flushing is discharged from the nozzle, it is possible to eliminate the drying of the nozzle and prevent unnecessary discharge of liquid.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0010] Hereinafter, preferred embodiments of the present invention will be described.

[0011] <Overall Configuration of Printer> As shown in FIG. 1, a printer 1 (the "liquid ejection device" of the present invention) according to this embodiment includes a carriage 2, an inkjet head 3 (the "liquid ejection head" of the present invention), a platen 4, transport rollers 5 and 6, a maintenance unit 7, and the like.

[0012] The carriage 2 is supported by two guide rails 11 and 12 extending in the horizontal scanning direction. The carriage 2 is connected to a carriage motor 86 (see FIG. 5) via a belt or the like not shown. When the carriage motor 86 is driven, the carriage 2 moves in the scanning direction along the guide rails 11 and 12. Hereinafter, as shown in FIG. 1, the right side and the left side in the scanning direction are defined for explanation.

[0013] The inkjet head 3 is mounted on the carriage 2. The inkjet head 3 ejects ink (the "liquid" of the present invention) from a plurality of nozzles 10 formed on the nozzle surface 3a which is the lower surface thereof. The plurality of nozzles 10 form four nozzle groups 8 arranged in the scanning direction. From the plurality of nozzles 10, black, yellow, cyan, and magenta inks are ejected in order from those forming the nozzle group 8 on the right side in the scanning direction. Further, the inkjet head 3 is connected to four ink cartridges (not shown) via tubes or the like not shown. And the four-color ink is supplied from these four ink cartridges to the inkjet head 3. The inkjet head 3 will be described in detail later.

[0014] The platen 4 is disposed below the inkjet head 3 and faces a plurality of nozzles 10. The platen 4 extends over the entire length of the recording paper P (the "medium to be ejected" of the present invention) in the scanning direction and supports the recording paper P from below. The transport rollers 5 and 6 are for transporting the recording paper P in a transport direction (the "one direction" of the present invention) that is horizontal and orthogonal to the scanning direction. The transport roller 5 is disposed upstream of the inkjet head 3 and the platen 4 in the transport direction. The transport roller 6 is disposed downstream of the inkjet head 3 and the platen 4 in the transport direction. The transport rollers 5 and 6 are connected to a transport motor 87 (see FIG. 5) via gears (not shown). When the transport motor 87 is driven, the transport rollers 5 and 6 rotate, and the recording paper P is transported in the transport direction.

[0015] The maintenance unit 7 includes a cap 71, a suction pump 72, and a waste liquid tank 73. The cap 71 is disposed on the right side of the platen 4 in the scanning direction. When the carriage 2 is positioned at a maintenance position on the right side of the platen 4 in the scanning direction, the plurality of nozzles 10 face the cap 71.

[0016] Further, the cap 71 can be moved up and down by a cap lifting mechanism 88 (see FIG. 5). The cap lifting mechanism 88 has a motor or the like and can move the cap 71 up and down independently of the movement of the carriage 2. When the carriage 2 is positioned at the maintenance position so that the plurality of nozzles 10 face the cap 71 and the cap 71 is lifted by the cap lifting mechanism 88, the upper end portion of the cap 71 comes into close contact with the nozzle surface 3a, and the plurality of nozzles 10 are covered by the cap 71 to be in a capped state. Also, when the cap 71 is lowered by the cap lifting mechanism 88 while in the capped state, the cap 71 moves away from the inkjet head 3 more than in the capped state, and the plurality of nozzles 10 of the inkjet head 3 are exposed to be in an uncapped state.

[0017] In this embodiment, the combination of the carriage 2 and the cap lifting mechanism 88 corresponds to the "switching means" of the present invention. Further, the cap 71 is not limited to covering the plurality of nozzles 10 by closely adhering to the nozzle surface 3a. The cap 71 may cover the plurality of nozzles 10, for example, by closely adhering to a frame (not shown) or the like arranged around the nozzle surface 3a of the inkjet head 3.

[0018] The suction pump 72 is a tube pump or the like, and is connected to the cap 71 and the waste liquid tank 73. In the maintenance unit 7, when the suction pump 72 is driven in the above cap state, so-called suction purge can be performed to discharge the ink in the inkjet head 3 from the plurality of nozzles 10. The ink discharged by the suction purge is stored in the waste liquid tank 73.

[0019] Here, for the sake of convenience, it has been described that the cap 71 collectively covers all the nozzles 10 and discharges the ink in the inkjet head 3 from all the nozzles 10 in the suction purge, but this is not limiting. For example, the cap 71 may separately include a portion covering the plurality of nozzles 10 forming the rightmost nozzle group 8 that discharges black ink and a portion covering the plurality of nozzles 10 forming the three leftmost nozzle groups 8 that discharge color ink (yellow, cyan, magenta inks), and in the suction purge, either the black ink or the color ink in the inkjet head 3 may be selectively discharged. Alternatively, for example, the cap 71 may be provided individually for each nozzle group 8, and in the suction purge, ink may be discharged from the nozzles 10 individually for each nozzle group 8.

[0020] <inkjet head> Next, the inkjet head 3 will be described. As shown in FIGS. 2 to 4, the inkjet head 3 includes a flow path unit 21 and a piezoelectric actuator 22.

[0021] <flow path unit> The flow path unit 21 is formed by vertically stacking plates 31 to 35 in this order from below. The flow path unit 21 also has a plurality of nozzles 10, a plurality of pressure chambers 51, a plurality of descender flow paths 52, and a plurality of throttle flow paths 53.

[0022] The plurality of nozzles 10 are formed on the plate 31. The plurality of nozzles 10 form a nozzle row 9 by being arranged at a constant interval R in the conveyance direction. Further, four nozzle rows 9 are arranged in the scanning direction to form a nozzle group 8. Also, four nozzle groups 8 are lined up in the scanning direction.

[0023] In each nozzle group 8, among the four nozzle rows 9, the nozzle 10 forming the rightmost nozzle row 9 is displaced downstream in the conveyance direction by a length (R / 4) with respect to the nozzle 10 forming the second nozzle row 9 from the left in the scanning direction. Also, the nozzle 10 forming the third nozzle row 9 from the left in the scanning direction is displaced downstream in the conveyance direction by a length (R / 4) with respect to the nozzle 10 forming the rightmost nozzle row 9. Further, the nozzle 10 forming the leftmost nozzle row 9 is displaced downstream in the conveyance direction by a length (R / 4) with respect to the nozzle 10 forming the third nozzle row 9 from the left. As a result, in the nozzle group 8, in the conveyance direction, the nozzles 10 are arranged at an interval of (R / 4).

[0024] The plurality of pressure chambers 51 are formed on the plate 35. The plurality of pressure chambers 51 are provided individually for the plurality of nozzles 10. The nozzles 10 forming the first and third nozzle rows 9 from the left in each nozzle group 8 vertically overlap the right end portions of the corresponding pressure chambers 51. The nozzles 10 forming the second and fourth nozzle rows 9 from the left in each nozzle group 8 vertically overlap the left end portions of the corresponding pressure chambers 51.

[0025] The plurality of descender channels 52 are provided individually for the plurality of nozzles 10. The descender channels 52 extend vertically across the plates 32 to 34 and connect the nozzles 10 that overlap vertically with the end portions in the scanning direction of the pressure chambers 51.

[0026] The plurality of throttle channels 53 are provided individually for the plurality of pressure chambers 51. The throttle channels 53 are formed in the upper portion of the plate 33 and extend in the scanning direction.

[0027] In addition, the throttle channels 53 provided for the pressure chambers 51 corresponding to the 1st and 3rd nozzle rows 9 from the left in each nozzle group 8 extend vertically across the upper portion of the plate 33 and the plate 34 at the right end portion in the scanning direction and are connected to the left end portion in the scanning direction of the corresponding pressure chambers 51. Further, the throttle channels 53 provided for the pressure chambers 51 corresponding to the 1st and 3rd nozzle rows 9 from the left in each nozzle group 8 extend over the entire vertical length of the plate 33 at the left end portion in the scanning direction and open to the lower surface of the plate 33.

[0028] In addition, the throttle channels 53 provided for the pressure chambers 51 corresponding to the 2nd and 4th nozzle rows 9 from the left in each nozzle group 8 extend vertically across the upper portion of the plate 34 and the plate 34 at the left end portion in the scanning direction and are connected to the right end portion of the corresponding pressure chambers 51. Further, the throttle channels 53 provided for the pressure chambers 51 corresponding to the 2nd and 4th nozzle rows 9 from the left in each nozzle group 8 extend over the entire vertical length of the plate 33 at the right end portion in the scanning direction and open to the lower surface of the plate 33.

[0029] And in the flow path unit 21, individual flow paths 41 are formed by the corresponding nozzles 10, pressure chambers 51, descender channels 52, and throttle channels 53.

[0030] The flow path unit 21 also has 12 common flow paths 42. The 12 common flow paths 42 are formed in the plate 32, each extending in the conveyance direction and arranged in the scanning direction. Among the 12 common flow paths 42, every three adjacent ones correspond to one nozzle group 8.

[0031] Among the three common flow paths 42 corresponding to each nozzle group 8, the common flow path 42a at the left end in the scanning direction is connected to a plurality of throttle flow paths 53 corresponding to the leftmost nozzle row 9 among the four nozzle rows 9 forming the nozzle group 8, thereby communicating with the nozzles 10 forming the nozzle row 9.

[0032] Among the three common flow paths 42 corresponding to each nozzle group 8, the common flow path 42b at the center in the scanning direction is connected to a plurality of throttle flow paths 53 corresponding to the second and third nozzle rows 9 from the left among the four nozzle rows 9 forming the nozzle group 8, thereby communicating with the nozzles 10 forming the nozzle row 9.

[0033] Among the three common flow paths 42 corresponding to each nozzle group 8, the common flow path 42c at the right end in the scanning direction is connected to a plurality of throttle flow paths 53 corresponding to the rightmost nozzle row 9 among the four nozzle rows 9 forming the nozzle group 8, thereby communicating with the nozzles 10 forming the nozzle row 9.

[0034] Also, the three common flow paths 42a to 42c corresponding to each nozzle group 8 are connected to each other at the upstream end in the conveyance direction. A supply port 43 is provided at the connected portion of the three common flow paths 42a to 42c, and ink is supplied from the supply port 43 to the three common flow paths 42a to 42c.

[0035] <Piezoelectric actuator> The piezoelectric actuator 22 has a diaphragm 61, a piezoelectric layer 62, a common electrode 63, and a plurality of individual electrodes 64.

[0036] The diaphragm 61 and the piezoelectric layer 62 are made of a piezoelectric material mainly composed of lead zirconate titanate, which is a solid solution of lead titanate and lead zirconate. However, the diaphragm 61 may be made of an insulating material other than the piezoelectric material, such as a synthetic resin, for example.

[0037] The diaphragm 61 is disposed on the upper surface (the upper surface of the plate 35) of the flow path unit 21 and extends continuously over the entire area thereof. The piezoelectric layer 62 is disposed on the upper surface of the diaphragm 61 and extends continuously over the plurality of pressure chambers 51.

[0038] The common electrode 63 is disposed between the diaphragm 61 and the piezoelectric layer 62 and extends over the entire area thereof. The common electrode 63 is connected to a power source (not shown) via a wiring member or the like (not shown) and is held at the ground potential.

[0039] The plurality of individual electrodes 64 are disposed on the upper surface of the piezoelectric layer 62. The plurality of individual electrodes 64 are provided individually in the plurality of pressure chambers 51 and vertically overlap the central portions of the corresponding pressure chambers 51. The plurality of individual electrodes 64 are connected to a driver IC 89 (see FIG. 5) via a wiring member or the like (not shown). The driver IC 89 individually switches the potentials of the plurality of individual electrodes 64 between the ground potential and a predetermined driving potential (for example, about 20 to 30 V). Here, the portions of the piezoelectric layer 62 sandwiched between the common electrode 63 and each individual electrode 64 are polarized in the thickness direction. In the piezoelectric actuator 22, when the potential of the individual electrode 64 is switched between the ground potential and the driving potential as described above, the portions of the diaphragm 61 and the piezoelectric layer 62 that vertically overlap the pressure chambers 51 are deformed and the volumes of the pressure chambers 51 change. As a result, the pressure of the ink in the pressure chambers 51 changes, and the ink can be ejected from the nozzles 10 communicating with the pressure chambers 51.

[0040] <Electrical Configuration of the Printer> Next, the electrical configuration of the printer 1 will be described. As shown in FIG. 5, the printer 1 includes a control unit 80. The control unit 80 includes a CPU (Central Processing Unit) 81, a ROM (Read Only Memory) 82, a RAM (Random Access Memory) 83, a flash memory 84, an ASIC (Application Specific Integrated Circuit) 85, and the like. The control unit 80 controls the operations of a carriage motor 86, a driver IC 89, a conveyance motor 87, a cap lifting mechanism 88, a suction pump 72, and the like. In this embodiment, the control unit 80 controls the inkjet head 3 by controlling the driver IC 89.

[0041] In addition to the configuration described above, the printer 1 has a temperature sensor 91, a humidity sensor 92, and a timer 93. The temperature sensor 91 is mounted on, for example, the carriage 2. The temperature sensor 91 detects the temperature and outputs a signal corresponding to the detected temperature. The control unit 80 acquires temperature information by receiving the signal from the temperature sensor 91.

[0042] The humidity sensor 92 is mounted on, for example, the carriage 2. The humidity sensor 92 detects the humidity and outputs a signal corresponding to the detected humidity. The control unit 80 acquires humidity information by receiving the signal from the humidity sensor 92.

[0043] The timer 93 measures the uncapping time U (the "uncapping parameter" of the present invention) during which the uncapped state continues, and outputs a signal corresponding to the uncapping time U. The control unit 80 acquires the information of the uncapping time U by receiving the signal from the timer 93.

[0044] Note that the control unit 80 may be configured such that only the CPU 81 performs various processes, or only the ASIC 85 performs various processes, or the CPU 81 and the ASIC 85 cooperate to perform various processes. Also, the control unit 80 may be configured such that one CPU 81 performs processing alone, or a plurality of CPUs 81 perform processing in a shared manner. Further, the control unit 80 may be configured such that one ASIC 85 performs processing alone, or a plurality of ASICs 85 perform processing in a shared manner.

[0045] <Control during recording> Next, the control by the control unit 80 when recording is performed in the printer 1 will be described. In the printer 1, when recording or the above-described suction purge or the like is not being performed, it is in a standby state waiting to receive a recording command (the "discharge instruction signal" of the present invention) that instructs recording on the recording paper P in the cap state. Then, when a recording command is received in the standby state, the control unit 80 performs processing in accordance with the flow of FIG. 6.

[0046] More specifically, the control unit 80 first executes an uncapping process (S101). In the uncapping process, the control unit 80 controls the cap lifting mechanism 88 to lower the cap 71, thereby switching from the cap state to the uncapped state.

[0047] Subsequently, the control unit 80 executes a recording process (S102). In the recording process, the control unit 80 controls the carriage motor 86 to move the carriage 2 in the scanning direction, controls the driver IC 89 (inkjet head 3), and repeats a recording operation (the "discharge operation" of the present invention) that includes a recording path of discharging ink from a plurality of nozzles 10 toward the recording paper P and a conveyance operation of controlling the conveyance motor 87 to convey the recording paper P a predetermined distance by the conveyance rollers 5 and 6. Thereby, recording on the recording paper P is performed.

[0048] Subsequently, when the control unit 80 has received the next recording command (S103: YES), it returns to S102. When the next recording command has not been received (S103: NO), if the predetermined time has not elapsed (S104: NO), it returns to S103. Also, when the predetermined time has elapsed (S104: YES) without receiving the next recording command (S103: NO), the control unit 80 executes pre-wait flushing processing (S105).

[0049] In the pre-wait flushing processing, the control unit 80 controls the carriage motor 86 to move the carriage 2, thereby positioning the carriage 2 at the maintenance position. In this state, pre-wait flushing is performed to discharge ink from some of the nozzles 10 arranged continuously in the conveyance direction, including the end nozzle 10a on the most downstream side in the conveyance direction, among the plurality of nozzles 10 forming each nozzle row 9 in the inkjet head 3.

[0050] Here, in the present embodiment, a table associating the uncapping time U and temperature T, as shown in FIG. 7(a), with the basic discharge times N (N11 to N33) is stored in the flash memory 84. For U1 and U2 in the table of FIG. 7(a), and T1 and T2, there are the magnitude relationships of U1 < U2 and T1 < T2, respectively. For example, U1 is about 1 minute and U2 is about 5 minutes. Also, for example, T1 is about 18°C and T2 is about 33°C.

[0051] N11 to N33 in the table of FIG. 7(a) are in the magnitude relationships of N11 < N12 < N13, N21 < N22 < N23, N31 < N32 < N33, N11 < N21 < N31, N12 < N22 < N32, and N13 < N23 < 33.

[0052] Also, a table associating the temperature T and humidity H, as shown in FIG. 7(b), with the first coefficient K is stored in the flash memory 84. K11 to K33 in the table of FIG. 7(b) are in the magnitude relationships of K11 > K12 > K13, K21 > K22 > K23, K31 > K32 > K33, K11 > K21 > K31, K12 > K22 > K32, and K13 > K23 > 33.

[0053] Further, in the flash memory 84, a table associating the second coefficient J with whether the nozzle 10 communicates with the central common flow path 42b or the common flow paths 42a and 42c at both ends among the three common flow paths 42a to 42c as shown in FIG. 7(c) is stored. J1 and J2 in the table of FIG. 7(c) are in the magnitude relationship of J1 < J2.

[0054] Then, in the pre-wait flushing, the control unit 80 determines the basic discharge frequency N based on the uncapping time U, the temperature T detected by the temperature sensor 91 during the recording process, and the table of FIG. 7(a). Also, the first coefficient K is determined based on the temperature T detected by the temperature sensor 91 during the recording on the recording paper P and the humidity H detected by the humidity sensor 92 during the recording on the recording paper P, and the table of FIG. 7(b). Further, the second coefficient J is determined based on which common flow path 42 the nozzle 10 communicates with and the table of FIG. 7(c). Then, ink is discharged from the above-mentioned partial nozzles 10 (N×K×J) times, which is the number obtained by multiplying the basic discharge frequency N by the first coefficient K and the second coefficient J. In the present embodiment, the uncapping time U, the temperature T detected by the temperature sensor 91 during the recording on the recording paper P, the humidity H detected by the humidity sensor 92 during the recording on the recording paper P, and which common flow path 42 the nozzle 10 communicates with correspond to the "parameters before standby" of the present invention.

[0055] Subsequently, the control unit 80 executes the cap process (S106). In the cap process, the control unit 80 controls the cap elevating mechanism 88 to raise the carriage 2 to switch from the uncapped state to the capped state. As a result, the printer 1 enters a standby state waiting for the reception of the next recording command in the capped state.

[0056] <Effect> In this embodiment, by performing pre-wait flushing, after the completion of recording on the recording paper P, the drying of the ink in the nozzles 10 can be eliminated before entering the standby state. Further, in the pre-wait flushing, in order to discharge an amount of ink corresponding to a pre-wait parameter related to the degree of drying of the nozzles 10 immediately before the pre-wait flushing from the nozzles 10, the drying of the nozzles 10 can be eliminated, and the ink can be prevented from being discharged more than necessary.

[0057] Also, immediately after recording on the recording paper P, due to the difference in the usage frequency among the plurality of nozzles 10 of the inkjet head 3 during recording, a difference may occur in the degree of progress of ink drying among the plurality of nozzles 10 of the inkjet head 3. For the nozzles 10 with a low usage frequency, it is conceivable to perform flushing during recording to eliminate the ink drying. However, even in this case, the difference in the degree of progress of ink drying among the plurality of nozzles 10 of the inkjet head 3 may not be sufficiently reduced. Further, when entering the standby state and then receiving the next recording command, depending on the degree of progress of ink drying in the plurality of nozzles 10 of the inkjet head 3 at that time, it may be necessary to perform, for example, suction purge to discharge ink from the plurality of nozzles 10 before recording on the recording paper P.

[0058] At this time, different from this embodiment, if pre-wait flushing is not performed, when the next recording command is received, a difference in the degree of progress of ink drying occurs among the plurality of nozzles 10 of the inkjet head 3. Therefore, it is necessary to set the ink discharge amount in the suction purge to the amount corresponding to the nozzle 10 with the largest degree of progress of ink drying. In this case, for the nozzles 10 with a small degree of progress of ink drying, excessive ink will be discharged.

[0059] In this embodiment, after the recording on the recording paper P is completed, pre-wait flushing is performed until the standby state is reached. Therefore, immediately before entering the standby state, the degree of ink drying can be made uniform among the plurality of nozzles 10 of the inkjet head 3. After that, until the next recording command is received, the drying of the ink in each nozzle 10 proceeds in the capped state. However, even when the next recording command is received, the degree of ink drying becomes uniform among the plurality of nozzles 10 of the inkjet head 3. Therefore, before performing the recording based on the next recording command, the discharge amount of the ink in the suction purge can be made appropriate according to the degree of progress of the drying of the ink in the plurality of nozzles 10.

[0060] Also, in this embodiment, in the common flow path 42, the ink is more likely to stagnate in the downstream portion in the conveyance direction farther from the supply port 43. Further, since the stagnant ink in the common flow path 42 is supplied to the nozzles 10 on the downstream side in the conveyance direction farther from the supply port 43, the degree of drying is large. Therefore, in this embodiment, in the pre-wait flushing, the ink is discharged from at least the end nozzle 10a. Thereby, after the recording on the recording paper P is completed, until the standby state is reached, the drying in the nozzles 10 with a large degree of drying is eliminated, and the variation in the degree of ink drying among the plurality of nozzles 10 forming the nozzle row 9 can be suppressed. Also, the stagnant ink in the portion of the common flow path 42 farther from the supply port 43 can be efficiently discharged.

[0061] Also, when the usage frequency of the printer 1 is high, after switching from the capped state to the uncapped state, until switching back to the capped state again, recordings based on a plurality of recording commands are often continuously performed. And in this case, the uncapping time becomes long, and the drying of the ink in the nozzles 10 tends to proceed. On the other hand, when the usage frequency of the printer 1 is low, after switching from the capped state to the uncapped state, until switching back to the capped state again, only the recording based on one recording command is often performed. And in this case, the uncapping time becomes short, and the drying of the ink in the nozzles 10 hardly proceeds.

[0062] Therefore, in the present embodiment, the uncapping time U is included in the pre-waiting parameters for determining the ink discharge amount (discharge frequency) in the pre-waiting flushing. The longer the uncapping time U is, the larger the ink discharge amount (basic discharge frequency N) in the pre-waiting flushing is made. As a result, in the pre-waiting flushing, an appropriate amount of ink corresponding to the degree of drying of the ink in the nozzle 10 that progresses in the uncapped state can be discharged. Also, in this case, when the usage frequency of the printer 1 is low, the ink discharge amount in the pre-waiting flushing is less than when the usage frequency of the printer 1 is high. As a result, regardless of the usage frequency of the printer 1, it is possible to prevent the ratio of the amount of ink discharged by the pre-waiting flushing to the amount of ink used for recording on the recording paper P from becoming too large.

[0063] Further, depending on the temperature at the time of recording on the recording paper P, the degree of progress of drying of the ink in the nozzle 10 and the ink in the cap 71 when recording is being performed on the recording paper P (when in the uncapped state) changes. Therefore, in the present embodiment, the temperature T detected by the temperature sensor 91 at the time of recording on the recording paper P is included in the pre-waiting parameters. Thereby, in the pre-waiting flushing, an appropriate amount of ink can be discharged according to the temperature at the time of recording on the recording paper P.

[0064] Also, depending on the humidity at the time of recording on the recording paper P, the degree of progress of drying of the ink in the nozzle 10 and the ink in the cap 71 when recording is being performed on the recording paper P (when in the uncapped state) changes. Therefore, in the present embodiment, the humidity detected by the humidity sensor 92 at the time of recording on the recording paper P is included in the pre-waiting parameters. Thereby, in the pre-waiting flushing, an appropriate amount of ink can be discharged according to the humidity at the time of recording on the recording paper P.

[0065] <Modification Example> As described above, the preferred embodiments of the present invention have been described. However, the present invention is not limited to the above-described embodiments, and various modifications are possible within the scope described in the claims.

[0066] In the above-described embodiment, in the pre-wait flushing, ink was discharged only from some of the nozzles 10 arranged continuously in the conveyance direction including the end nozzle 10a in each nozzle row 9, but the present invention is not limited to this. For example, in the pre-wait flushing, ink may be discharged only from the end nozzle 10a among the plurality of nozzles 10 forming each nozzle row 9. Alternatively, in the pre-wait flushing, ink may be discharged only from the nozzles 10 other than the end nozzle 10a among the plurality of nozzles 10 forming each nozzle row 9. Alternatively, in the pre-wait flushing, ink may be discharged from all of the nozzles 10 forming each nozzle row 9.

[0067] Also, in the pre-wait flushing, when ink is discharged only from only the end nozzle 10a of each nozzle row 9 or only from some of the nozzles 10 arranged continuously in the conveyance direction including the end nozzle 10a in each nozzle row 9, after the completion of the recording on the recording paper P, it is not limited to performing only the pre-wait flushing until the standby state is reached.

[0068] In Modification 1, when the control unit 80 receives a recording command in the standby state, it performs processing along the flow of FIG. 8. More specifically, the control unit 80 executes processing of S201 to S204 similar to S101 to S104 of the above-described embodiment. Then, after the completion of the recording process of S202, when a predetermined time has elapsed (S204: YES) without receiving the next recording command (S203: NO), the control unit 80 executes the preceding flushing process (S205), and then, after executing the pre-wait flushing process similar to S105 of the above-described embodiment (S206), executes the cap process similar to S106 of the above-described embodiment (S207).

[0069] In the pre-wait flushing process of S205, the control unit 80 causes pre-flushing to be performed to discharge ink from nozzles 10 that are upstream in the conveyance direction (closer to the supply port 43) than the nozzles 10 from which ink is discharged during pre-wait flushing among the plurality of nozzles 10 forming each nozzle row 9. Further, the ink discharge amount (discharge frequency) from each nozzle 10 during pre-flushing is made smaller than the ink discharge amount (discharge frequency) from each nozzle 10 during pre-wait flushing.

[0070] In Modification 1, during pre-wait flushing, ink is discharged from some of the continuously arranged nozzles 10 including the end nozzle 10a among the plurality of nozzles 10 forming each nozzle row 9. Further, pre-flushing is caused to be performed before pre-wait flushing, and during pre-flushing, ink is discharged from nozzles 10 that are closer to the supply port 43 than the nozzles 10 from which ink is discharged during pre-wait flushing. Thereby, appropriate amounts of ink can be discharged for the nozzles 10 far from the supply port 43 and the nozzles 10 close to it, respectively, according to the degree of ink drying.

[0071] Further, when pre-wait flushing is performed, ink in a portion of the common flow path 42 far from the supply port 43 is discharged, and ink flows into this portion of the common flow path 42 from a portion closer to the supply port 43 of the common flow path 42. In Modification 1, pre-flushing is performed before pre-wait flushing. As a result, pre-wait flushing is performed after the ink in the portion of the common flow path 42 close to the supply port 43 is discharged by pre-flushing. As a result, when performing pre-wait flushing, the ink flowing into the portion of the common flow path 42 far from the supply port 43 can be made into ink in which drying has not progressed as much. Further, thereby, the drying of the ink in the nozzles 10 from which ink is discharged during pre-wait flushing can be efficiently eliminated.

[0072] Also, in Modification 1, in the preliminary flushing, among the plurality of nozzles 10 forming each nozzle row 9, ink was discharged from the nozzles 10 on the upstream side in the conveyance direction (closer to the supply port 43) than the nozzles 10 from which ink was discharged in the pre-waiting flushing, but this is not limiting. For example, in the preliminary flushing, ink may be discharged from all the nozzles 10 forming each nozzle row 9. In this case, for example, for the nozzles 10 from which ink is discharged in the pre-waiting flushing, the total of the amount of ink discharged in the preliminary flushing and the amount of ink discharged in the pre-waiting flushing may be made the same as the amount of ink discharged in the pre-waiting flushing in Modification 1.

[0073] Also, in the above-described embodiment, the supply port 43 is provided at the upstream end in the conveyance direction of the common flow path 42, and among the plurality of nozzles 10 communicating with each common flow path 42, the nozzle 10 at the most downstream in the conveyance direction was the terminal nozzle 10a, but this is not limiting. For example, the supply port may be provided at the central portion in the conveyance direction of the common flow path 42. And, among the plurality of nozzles 10 communicating with each common flow path 42 and located upstream in the conveyance direction from the supply port, the nozzle 10 at the most upstream in the conveyance direction, and among the plurality of nozzles 10 communicating with each common flow path 42 and located downstream in the conveyance direction from the supply port, at least one of the nozzles 10 at the most downstream in the conveyance direction may be used as the terminal nozzle.

[0074] Also, in the above-described embodiment, the uncapping time U, the temperature T detected by the temperature sensor 91 during recording, the humidity H detected by the humidity sensor 92 during recording, and which common flow path 42 the nozzle 10 communicates with were used as pre-waiting parameters to determine the ink discharge amount in the pre-waiting flushing, but this is not limiting. Some of these may be used as pre-waiting parameters to determine the ink discharge amount in the pre-waiting flushing.

[0075] Further, for example, as a pre-wait parameter, instead of the uncapping time U, another uncapping parameter related to the uncapping time U and having a larger value as the uncapping time U is longer may be used. Also, for example, as a pre-wait parameter, instead of the temperature T detected by the temperature sensor 91 during recording, another parameter related to the temperature T may be used. Also, for example, as a pre-wait parameter, instead of the humidity H detected by the humidity sensor 92 during recording, another parameter related to the humidity may be used.

[0076] Furthermore, the pre-wait parameter may include another parameter different from the above-described one, which is related to the degree of drying of the ink in the nozzle 10 immediately before the pre-wait flushing.

[0077] Also, in the above-described embodiment, the discharge amount of ink from each nozzle 10 during the pre-wait flushing is the discharge amount necessary to eliminate the drying of the ink in the nozzle 10 mainly when recording is performed on the recording paper P in the uncapped state. However, even in the capped state, the drying of the ink in the nozzle 10 proceeds due to the evaporation of moisture in the ink from the nozzle 10 into the space in the cap 71, the evaporation of moisture from the ink in the nozzle 10 to the ink in the cap 71, and the like. In Modification 2, as described below, flushing is performed in further consideration of the progress of drying of the ink in the nozzle 10 in the capped state.

[0078] More specifically, in Modification 2, when the control unit 80 receives a recording command in the standby state, it performs processing along the flow of FIG. 9. In the flow of FIG. 9, the control unit 80 executes an uncapping process similar to S101 of the above-described embodiment (S301), and then executes a condition determination process (S302).

[0079] In the condition determination process, as shown in Fig. 10(a), first, the control unit 80 determines whether it is recording in the normal recording mode (the "first recording mode" of the present invention) (S401). In Modification 2, in the printer 1, selective recording can be performed in either the normal recording mode or a high-quality recording mode (the "second recording mode" of the present invention) that records with higher image quality than the normal recording mode.

[0080] Here, due to the influence of factors such as the inclination during the movement of the carriage 2 and the error during the attachment of the inkjet head 3 to the carriage 2, the arrangement direction of the plurality of nozzles 10 forming the nozzle row 9 may be slightly inclined with respect to the conveyance direction. On the other hand, the farther the nozzles 10 are from each other in the conveyance direction, the greater the deviation in the scanning direction between the nozzles 10 with respect to the inclination of the arrangement direction of the plurality of nozzles 10 forming the nozzle row 9 with respect to the conveyance direction.

[0081] Therefore, in Modification 2, as shown in Fig. 10(b), in the normal recording mode, recording is performed using all of the plurality of nozzles 10 forming each nozzle row 9. On the other hand, in the high-quality recording mode, recording is performed using only a part of the plurality of nozzles 10 that are arranged continuously in the conveyance direction among the plurality of nozzles 10 forming each nozzle row 9. The above-mentioned part of the nozzles 10 used in the high-quality recording mode is, for example, the upstream half or the downstream half of the plurality of nozzles 10 forming the nozzle row 9 in the conveyance direction. That is, when recording on the recording paper P in the high-quality recording mode, the number of nozzles 10 used for recording is smaller than when recording on the recording paper P in the normal recording mode. And thereby, in the normal recording mode, recording can be performed at a higher speed than in the high-quality recording mode, and in the high-quality recording mode, recording can be performed with higher image quality than in the normal recording mode.

[0082] Returning to Fig. 10(a), if it is not recording in the normal recording mode, that is, if it is recording in the high-quality recording mode (S401: NO), return to the flow of Fig. 9. If it is recording in the normal recording mode (S401: YES), the control unit 80 then determines whether the current temperature T (the temperature immediately before recording) detected by the temperature sensor 91 is equal to or higher than the temperature Ta (for example, about 18°C) and equal to or lower than the temperature Tb (for example, about 33°C) (S402).

[0083] If the temperature T is lower than the temperature Ta or higher than the temperature Tb (S402: NO), return to the flow of Fig. 9. If the temperature T is equal to or higher than the temperature Ta and equal to or lower than the temperature Tb (S402: YES), the control unit 80 then determines whether the current humidity H (the humidity immediately before recording) detected by the humidity sensor 92 is equal to or higher than the humidity Ha (for example, about 30%) and equal to or lower than the humidity Hb (for example, about 50%) (S403).

[0084] If the humidity H is lower than the humidity Ha or higher than the humidity Hb (S403: NO), return to the flow of Fig. 9. If the humidity H is equal to or higher than the humidity Ha and equal to or lower than the humidity Hb (S403: YES), the control unit 80 stores the skip flag information in the flash memory 84 (S404) and returns to the flow of Fig. 9. Here, in the condition determination process of S302, the skip flag information stored in the flash memory 84 in S404 indicates that the first flushing described later is not to be performed.

[0085] Note that, in Modification 2, the condition that the temperature T in S402 is equal to or higher than the temperature Ta and equal to or lower than the temperature Tb in the condition determination process of S302 corresponds to the "temperature condition before ejection" of the present invention. Further, in Modification 2, the condition that the humidity H in S403 is equal to or higher than the humidity Ha and equal to or lower than the humidity Hb in the condition determination process of S302 corresponds to the "humidity condition before ejection" of the present invention. Further, in Modification 2, the condition that recording is performed in the normal recording mode, the temperature T is equal to or higher than the temperature Ta and equal to or lower than the temperature Tb, and the humidity H is equal to or higher than the humidity Ha and equal to or lower than the humidity Hb in the condition determination process of S302 corresponds to the "skip condition before ejection" of the present invention. Then, in Modification 2, when the above skip condition before ejection is satisfied in the condition determination process of S302, skip flag information is stored in the flash memory 84.

[0086] Returning to FIG. 9, after the condition determination process of S302, the control unit 80 determines whether skip flag information is stored in the flash memory 84 (S303). If the skip flag information is not stored in the flash memory 84 (S303: NO), the control unit 80 executes a first flushing process (S304).

[0087] In the first flushing process, the control unit 80 causes the inkjet head 3 to perform a first flushing (the "another flushing" of the present invention) in which ink is ejected from all the nozzles 10 forming each nozzle row 9.

[0088] Here, in Modification 2, a table associating the cap time V (a parameter related to the elapsed time since the last flushing in the present invention), the temperature T, and the basic discharge times M (M11 to M33) as shown in FIG. 11 is stored in the flash memory 84. The cap time V is the time during which the cap state continues. Further, in Modification 2, the timer 93 measures the cap time V in addition to the uncapping time U.

[0089] For V1 and V2 in the table of FIG. 11, there is a magnitude relationship of V1 < V2. For example, V1 is about 1 minute and V2 is about 3 minutes. T1 and T2 in Table 11 are the same as T1 and T2 in Table 7(a). For M11 to M33 in FIG. 11, there are magnitude relationships of M11 < M12 < M13, M21 < M22 < M23, M31 < M32 < M33, M11 < M21 < M31, M12 < M22 < M32, and M13 < M23 < M33.

[0090] In the first flushing process, the control unit 80 determines the basic discharge count M based on the cap time V, the current temperature T (immediately before the recording process) detected by the temperature sensor 91, and the table of FIG. 11. Also, the control unit 80 determines the first coefficient K based on the current temperature T detected by the temperature sensor 91 (immediately before the recording process) and the current humidity H detected by the humidity sensor 92 (immediately before the recording process), and the table of FIG. 7(b). Also, the control unit 80 determines the second coefficient J based on which common flow path 42 the nozzle 10 communicates with and the table of FIG. 7(c). Then, the control unit 80 discharges ink from each nozzle 10 (M × K × J) times, which is the number obtained by multiplying the basic discharge count M by the first coefficient K and the second coefficient J.

[0091] Note that in Modification 2, the cap time V, the temperature detected by the temperature sensor 91 immediately before recording, the humidity detected by the humidity sensor 92 immediately before recording, and which common flow path 42 the nozzle 10 communicates with correspond to the "drying progress parameters" of the present invention.

[0092] After the completion of the first flushing, the control unit 80 executes processes S305 to S307 similar to S102 to S104 of the above-described embodiment.

[0093] On the other hand, when skip flag information is stored in the flash memory 84 (S303: YES), the control unit 80 erases the skip flag information stored in the flash memory 84 (S308), and then executes the processes of S305 to S307. That is, when skip flag information is stored in the flash memory 84, the first flushing is not performed before recording on the recording paper P.

[0094] After the recording process of S305, when a predetermined time has elapsed without receiving the next recording command (S306: NO) (S307: YES), the control unit 80 executes condition determination processing (S309). Similar to S302, in the condition determination processing of S309, the control unit 80 executes the processing along the flowchart of FIG. 10(a). However, in the condition determination processing of S309, in S402, it is determined whether or not the temperature T detected by the temperature sensor 91 during recording on the recording paper P is equal to or higher than the temperature Ta and equal to or lower than the temperature Tb. Further, in S403, it is determined whether or not the humidity H detected by the humidity sensor 92 during recording on the recording paper P is equal to or higher than the humidity Ha and equal to or lower than the humidity Hb. Also, in the condition determination processing of S309, at least a part of the temperature Ta, Tb in S402 and the humidity Ha, Hb in S403 may be different from the condition determination processing of S302.

[0095] Note that in Modification 2, the condition that the temperature T in S402 is equal to or higher than the temperature Ta and equal to or lower than the temperature Tb in the condition determination processing of S309 corresponds to the "temperature condition during ejection" of the present invention. Also, in Modification 2, the condition that the humidity H in S403 is equal to or higher than the humidity Ha and equal to or lower than the humidity Hb in the condition determination processing of S309 corresponds to the "pre-humidity condition during ejection" of the present invention. Further, in Modification 2, the condition of performing recording in the normal recording mode, and the temperature T being equal to or higher than the temperature Ta and equal to or lower than the temperature Tb, and the humidity H being equal to or higher than the humidity Ha and equal to or lower than the humidity Hb in the condition determination processing of S309 corresponds to the "skip condition after ejection" of the present invention.

[0096] And in Modification 2, in the condition determination process of S309, when the post - discharge skip condition is satisfied, skip flag information is stored in the flash memory 84. Here, in the condition determination process of S309, the skip flag information to be stored in the flash memory 84 in S404 indicates that the second flushing described later is not to be performed.

[0097] After the condition determination process of S309, the control unit 80 then determines whether skip flag information is stored in the flash memory 84 (S310). If the skip flag information is not stored in the flash memory 84 (S310: NO), the control unit 80 executes the second flushing process (S311).

[0098] In the second flushing process, the control unit 80 causes the inkjet head 3 to perform a second flushing (the "another flushing" of the present invention) in which ink is discharged from all the nozzles 10 forming each nozzle row 9.

[0099] Also, in the second flushing process, the control unit 80 determines the basic discharge times M based on the cap time V, the temperature T detected by the temperature sensor 91 during recording on the recording paper P, and the table in FIG. 11. Also, based on the temperature T detected by the temperature sensor 91 during recording on the recording paper P and the humidity H detected by the humidity sensor 92 during recording on the recording paper P, and the table in FIG. 7(b), the first coefficient K is determined. Also, based on which common flow path 42 the nozzle 10 communicates with and the table in FIG. 7(c), the second coefficient J is determined. Then, the control unit 80 discharges ink from each nozzle 10 for (M×K×J) times, which is the number obtained by multiplying the basic discharge times M by the first coefficient K and the second coefficient J.

[0100] And after the completion of the second flushing, a pre - standby flushing process similar to S105 of the above - described embodiment is executed (S312), and subsequently, a capping process similar to S106 of the above - described embodiment is executed (S313).

[0101] On the other hand, when skip flag information is stored in the flash memory 84 (S310: YES), the control unit 80 erases the skip information stored in the flash memory 84 (S314), and then executes the pre-wait flushing process in S313 and the capping process in S314. That is, when skip flag information is stored in the flash memory 84, after the completion of recording on the recording paper P, pre-wait flushing is performed before entering the standby state, and the second flushing is not performed.

[0102] In Modification 2, separately from the pre-wait flushing, first and second flushing are performed to discharge an amount of ink from the nozzles according to the value of a drying progress parameter related to the degree of progress of drying of the ink in the nozzles 10 in the capped state. Thereby, it is possible to eliminate the drying of the ink in the nozzles 10 that has progressed in the capped state. Also, it is possible to prevent the amount of ink discharged by the first and second flushing from becoming excessive.

[0103] In the normal recording mode, it is required to perform recording as fast as possible because high image quality is not required. On the other hand, high image quality is required in the high image quality recording mode. Therefore, in Modification 2, when recording on the recording paper P is performed in the high image quality recording mode, the inkjet head 3 is made to perform the first flushing and then the recording operation on the recording paper P is performed. Thereby, since recording is performed after the drying of the ink in the nozzles 10 is eliminated, high-quality recording becomes possible.

[0104] On the other hand, when the recording pre-skip conditions for recording on the recording paper P in the normal recording mode are satisfied, the inkjet head 3 is made to perform recording on the recording paper P without performing the first flushing. Thereby, it is possible to suppress the discharge of unnecessary ink and to accelerate the start of the ejection operation.

[0105] Also, the influence of the progress of drying of the ink in the nozzles 10 in the capped state on the ejection of ink from the nozzles 10 during recording on the recording paper P varies depending on the temperature during recording on the recording paper P.

[0106] Therefore, in Modification 2, when the temperature T detected by the temperature sensor 91 immediately before recording on the recording paper P is lower than the temperature Ta or higher than the temperature Tb (not satisfying the pre-ejection temperature condition), the inkjet head 3 is made to perform the first flushing and then recording on the recording paper P is performed. Thereby, ink can be normally ejected from the nozzles 10 when recording on the recording paper P.

[0107] On the other hand, when the temperature T detected by the temperature sensor 91 immediately before recording on the recording paper P satisfies the pre-ejection skip condition including the pre-ejection temperature condition that the temperature T is equal to or higher than the temperature Ta and equal to or lower than the temperature Tb, the inkjet head 3 is made to perform recording on the recording paper P without performing the first flushing. Thereby, wasteful ink discharge can be suppressed, and the time from receiving the recording command to starting the ejection operation onto the recording paper P can be shortened.

[0108] Also, depending on the humidity during recording on the recording paper P, the degree to which the progress of drying of the ink in the nozzles 10 in the cap state affects the ejection of the ink from the nozzles 10 during recording on the recording paper P changes.

[0109] Therefore, in Modification 2, when the humidity H detected by the humidity sensor 92 immediately before recording on the recording paper P is lower than the humidity Ha or higher than the humidity Hb (not satisfying the pre-ejection humidity condition), the inkjet head 3 is made to perform the first flushing and then recording on the recording paper P is performed. Thereby, ink can be normally ejected from the nozzles 10 when recording on the recording paper P.

[0110] When the pre-discharge skip condition including the pre-discharge humidity condition that the humidity H detected by the humidity sensor 92 immediately before recording on the recording paper P is equal to or higher than the humidity Ha and equal to or lower than the humidity Hb is satisfied, the inkjet head 3 is caused to perform recording on the recording paper P without performing the first flushing. As a result, it is possible to suppress the discharge of waste ink and shorten the time from receiving the recording command to starting the discharge operation onto the recording paper P.

[0111] Further, when performing recording on the recording paper P in the high-quality recording mode, for the nozzles 10 used for recording, when ink is discharged during recording on the recording paper P, the drying of the ink that has advanced in the cap state is eliminated. However, for the nozzles 10 not used for recording, the drying of the ink that has advanced in the cap state is not eliminated during recording on the recording paper P.

[0112] Therefore, in the second modification, when performing recording in the high-quality recording mode, after the completion of recording on the recording paper P and before entering the standby state, the inkjet head 3 is caused to perform pre-standby flushing and second flushing. As a result, it is possible to eliminate the drying of the ink that has advanced in the cap state in the nozzles 10 not used for recording on the recording paper P.

[0113] On the other hand, when the post-discharge skip condition for performing recording in the normal recording mode is satisfied, after recording on the recording paper P and before entering the standby state, the inkjet head 3 is caused to perform pre-standby flushing and not perform second flushing. As a result, it is possible to suppress the discharge of waste ink.

[0114] In addition, depending on the temperature during recording on the recording paper P, the degree to which the drying of the ink in the nozzles that have advanced in the cap state affects the drying of the ink in the nozzles 10 at the completion of recording on the recording paper P changes.

[0115] Therefore, in Modification 2, when the temperature T detected by the temperature sensor 91 during recording on the recording paper P is less than the temperature Ta or higher than the temperature Tb (the ejection temperature condition is not satisfied), after the recording on the recording paper P is completed, before entering the standby state, the inkjet head 3 is made to perform pre-standby flushing and second flushing. Thereby, for example, for nozzles 10 with low usage frequency during recording on the recording paper P, it is possible to eliminate the drying of the ink that has progressed in the capped state.

[0116] On the other hand, when the temperature T detected by the temperature sensor 91 during recording on the recording paper P satisfies the ejection post-skip condition including the ejection temperature condition that the temperature T is equal to or higher than the temperature Ta and equal to or lower than the temperature Tb, after the recording on the recording paper P is completed, before entering the standby state, the inkjet head 3 is made to perform pre-standby flushing and not perform second flushing. Thereby, it is possible to suppress the discharge of unnecessary liquid.

[0117] Also, depending on the humidity during recording on the recording paper P, the degree to which the drying of the ink in the nozzles 10 that has progressed in the capped state affects the drying of the ink in the nozzles 10 at the completion of recording on the recording paper P changes.

[0118] Therefore, in Modification 2, when the humidity H detected by the humidity sensor 92 during recording on the recording paper P is less than the humidity Ha or higher than the humidity Hb (the ejection humidity condition is not satisfied), after the recording on the recording paper P is completed, before entering the standby state, the inkjet head 3 is made to perform pre-standby flushing and second flushing. Thereby, for example, for nozzles 10 with low usage frequency during recording on the recording paper P, it is possible to eliminate the drying of the ink that has progressed in the capped state.

[0119] On the other hand, when the humidity H detected by the humidity sensor 92 during recording on the recording paper P satisfies the ejection post-skip condition including the ejection humidity condition that the humidity H is equal to or higher than the humidity Ha and equal to or lower than the humidity Hb, after the recording on the recording paper P is completed, before entering the standby state, the inkjet head 3 is made to perform pre-standby flushing and not perform second flushing. Thereby, it is possible to suppress the discharge of unnecessary ink.

[0120] Also, the longer the cap time V is, the more the drying of the ink in the nozzle 10 progresses in the cap state. Therefore, in Modification 2, the cap time V is included in the drying progress parameter for determining the discharge amount (discharge frequency) of the ink in the first and second flushing. Thereby, based on the drying progress parameter, the discharge amount of the ink in the first and second flushing can be appropriately determined.

[0121] Also, the degree of progress of the drying of the ink in the nozzle 10 in the cap state varies depending on the temperature in the standby state (cap state). Therefore, in Modification 2, the temperature detected by the temperature sensor in the standby state is included in the drying progress parameter. Thereby, based on the drying progress parameter, the discharge amount of the ink in the first and second flushing can be appropriately determined.

[0122] Also, the degree of progress of the drying of the ink in the nozzle 10 in the cap state varies depending on the humidity in the standby state (cap state). Therefore, in Modification 2, the humidity detected by the humidity sensor in the standby state is included in the drying progress parameter for determining the discharge amount (discharge frequency) of the ink in the first and second flushing. Thereby, based on the drying progress parameter, the discharge amount of the ink in the first and second flushing can be appropriately determined.

[0123] Also, the pre-recording skip conditions are not limited to those of Modification 2. For example, the "pre-recording temperature condition" included in the pre-recording skip conditions may be another condition related to the temperature T detected by the temperature sensor 91 immediately before recording on the recording paper P. Also, for example, the "pre-recording humidity condition" included in the pre-recording skip conditions may be another condition related to the humidity H detected by the humidity sensor 92 immediately before recording on the recording paper P.

[0124] Further, the pre-recording skip conditions may include only some of the conditions among the condition of being in the normal recording mode, the pre-recording temperature condition, and the pre-recording humidity condition. Further, the pre-recording skip conditions may include conditions other than the condition of being in the normal recording mode, the pre-recording temperature condition, and the pre-recording humidity condition.

[0125] Further, the post-recording skip conditions are not limited to those of Modification 2. For example, the "recording temperature condition" included in the post-recording skip conditions may be another condition related to the temperature T detected by the temperature sensor 91 during recording on the recording paper P. Further, for example, the "recording humidity condition" included in the post-recording skip conditions may be another condition related to the humidity H detected by the humidity sensor 92 during recording on the recording paper P.

[0126] Further, the post-recording skip conditions may include only some of the conditions among the condition of being in the normal recording mode, the recording temperature condition, and the recording humidity condition. Further, the post-recording skip conditions may include conditions other than the condition of being in the normal recording mode, the recording temperature condition, and the recording humidity condition.

[0127] Further, in Modification 2, a condition determination process is executed before recording on the recording paper P (S302), and based on the result, it is determined whether or not to perform the first flushing. Also, a condition determination process is executed after recording on the recording paper P (S309), and based on the result, it is determined whether or not to perform the second flushing. However, it is not limited to this. For example, based on the result of the condition determination process before recording on the recording paper P, it may be determined whether or not to perform the first flushing and whether or not to perform the second flushing. That is, in Modification 2, the condition determination process of S302 may be executed, and the condition determination process of S309 may not be executed.

[0128] In this case, whether to perform the second flushing is determined based on the temperature T detected by the temperature sensor 91 immediately before recording on the recording paper P and the humidity H detected by the humidity sensor 92 immediately before recording on the recording paper P. However, the changes in temperature and humidity are slight between immediately before recording on the recording paper P and during recording on the recording paper P. Therefore, even in this case, substantially, whether to perform the second flushing is determined based on the temperature T detected by the temperature sensor 91 during recording on the recording paper P and the humidity H detected by the humidity sensor 92 during recording on the recording paper P. Also, in this case, when skip flag information is stored in the flash memory 84 in S303, the recording process of S305 is advanced without erasing the skip flag information, and the skip flag information is erased only in S314.

[0129] Also, in Modification 2, when the pre-recording skip condition is not satisfied, the first flushing is performed before recording on the recording paper P, and when the post-recording skip condition is not satisfied, the second flushing is performed after the completion of recording on the recording paper P until the standby state is reached. However, this is not limiting.

[0130] For example, before recording on the recording paper P, the first flushing may not always be performed, and when the post-recording skip condition is not satisfied, the second flushing may be performed after the completion of recording on the recording paper P until the standby state is reached.

[0131] Alternatively, before recording on the recording paper P, if the pre-recording skip condition is not satisfied, the first flushing may be performed. After the completion of recording on the recording paper P, the second flushing may not always be performed until the standby state is reached. Also, in this case, all the nozzles 10 forming the nozzle row 9 may be used when recording in either the normal recording mode or the high-quality recording mode. In this case, for example, in the high-quality recording mode, the amount of ink ejected from the nozzles 10 during recording is made less than that in the normal-quality mode. Thereby, in the high-quality mode, the dot size forming the recorded image can be made smaller than that in the normal-quality mode, and the image quality of the recorded image can be improved.

[0132] Also, in Modification 2, the first flushing is performed before recording on the recording paper P only when the pre-recording skip condition is not satisfied, but this is not restrictive. For example, the first flushing may always be performed before recording on the recording paper P.

[0133] Also, in Modification 2, the second flushing is performed after the completion of recording on the recording paper P until the standby state is reached only when the post-recording skip condition is not satisfied, but this is not restrictive. For example, the second flushing may always be performed after the completion of recording on the recording paper P.

[0134] Also, in Modification 2, the number of ink discharges from each nozzle 10 in the first and second flushing is determined based on the cap time, the temperature detected by the temperature sensor 91, the humidity detected by the humidity sensor 92, and which common flow path the nozzle 10 communicates with, but this is not restrictive. For example, instead of the cap time, another parameter related to the elapsed time since the last flushing was performed may be used. Also, another parameter related to the temperature detected by the temperature sensor 91 may be used. Also, another parameter related to the humidity detected by the humidity sensor 92 may be used.

[0135] In addition, the drying progress parameters for determining the number of discharges of ink from each nozzle 10 in the first and second flushing are not limited to including parameters related to the capping time, parameters related to the temperature detected by the temperature sensor 91, parameters related to the humidity detected by the humidity sensor 92, and parameters related to which common flow path the nozzle 10 communicates with.

[0136] The drying progress parameters may include only some of these parameters. Further, the drying progress parameters may include parameters related to the degree of progress of drying of the ink in the nozzle 10 in the capped state, which are different from these parameters.

[0137] In addition, in the second modification, ink was discharged from all the nozzles 10 forming the nozzle row 9 in the first and second flushing, but it is not limited to this.

[0138] For example, in the capped state, drying of the ink progresses more easily in the downstream portion (the portion far from the supply port 43) in the conveyance direction of the common flow path 42. Therefore, for example, in the first and second flushing, among the plurality of nozzles 10 constituting the nozzle row 9, ink may be discharged from the end nozzle or a continuous part of the nozzles 10 including the end nozzle 10a, and ink may not be discharged from the other nozzles 10.

[0139] In addition, when recording is performed in the high-quality recording mode, among the plurality of nozzles 10 forming the nozzle row 9, nozzles other than a continuous part of the nozzles 10 are not used. And the nozzles 10 that were not used at the time of recording on the recording paper P have more ink drying progress at the completion of recording on the recording paper P than the used nozzles 10. Therefore, for example, in the second flushing, among the plurality of nozzles 10 constituting the nozzle row 9, ink may be discharged from the nozzles 10 that were not used at the time of recording on the recording paper P, and ink may not be discharged from the nozzles 10 that were used at the time of recording on the recording paper P.

[0140] In the above examples, after performing pre-wait flushing, the state was switched from the uncapped state to the capped state. However, this is not restrictive. For example, after switching from the uncapped state to the capped state, pre-wait flushing may be performed in the capped state, and after completion of the pre-wait flushing, it may be set to a standby state where reception of the next recording command is awaited in the capped state. Also, with regard to the pre-flushing of Modification Example 1 and the second flushing of Modification Example 2, they may be performed after switching from the uncapped state to the capped state.

[0141] In the above examples, in flushing, liquid was discharged from nozzle 10 toward cap 71. However, this is not restrictive. For example, an ink receiver may be provided at a position to the left of platen 4 in the scanning direction, and in flushing, after moving carriage 2 to a position where a plurality of nozzles 10 face the ink receiver, ink may be discharged from nozzle 10 toward the ink receiver. Alternatively, for example, platen 4 may be made longer in the scanning direction than the area where recording paper P is conveyed, and in flushing, ink may be discharged from nozzle 10 toward a portion outside the portion of platen 4 that faces the conveyance area of recording paper P.

[0142] In the above examples, the cap lifting mechanism 88 had a motor or the like not shown in the figure and lifted and lowered cap 71 independently of the movement of carriage 2. However, this is not restrictive. The cap lifting mechanism may be configured, for example, such that a force is applied from carriage 2 that moves in the scanning direction in the vicinity of the maintenance position, and may be a mechanism that lifts and lowers cap 71 using the force applied from carriage 2.

[0143] In the above, an example in which the present invention is applied to a printer equipped with a so-called serial head that discharges ink from a plurality of nozzles while moving in the scanning direction together with a carriage has been described. However, this is not restrictive. For example, it is also possible to apply the present invention to a printer equipped with a so-called line head that extends over the entire length of the recording paper in the scanning direction.

[0144] Also, in the above description, an example of applying the present invention to a printer that ejects ink from a nozzle to perform recording on a recording paper P has been described, but the present invention is not limited thereto. The present invention can also be applied to printers that record images on recording media other than recording paper, such as T-shirts, sheets for outdoor advertisements, cases of mobile terminals such as smartphones, cardboard, and resin members. Further, the present invention can also be applied to liquid ejection devices that eject liquids other than ink, for example, resins or metals in a liquid state.

Explanation of Reference Numerals

[0145] 1 Printer 2 Carriage 3 Inkjet Head 9 Nozzle Row 10 Nozzle 10a End Nozzle 42 Common Flow Path 43 Supply Port 71 Cap 80 Control Unit 88 Cap Lifting Mechanism 91 Temperature Sensor 92 Humidity Sensor

Claims

1. A liquid ejection head having nozzles, a cap covering the nozzles, switching means for switching between a capped state in which the nozzles are covered by the cap and an uncapped state in which the cap is separated from the liquid ejection head and the nozzles are exposed relative to the capped state, a control unit, and comprising, wherein the liquid ejection head, a nozzle row formed by arranging a plurality of the nozzles in one direction, a common flow path extending in the one direction and communicating with the plurality of nozzles forming the nozzle row, and a supply port for supplying liquid to the common flow path, wherein the control unit, when receiving a discharge instruction signal instructing the discharge of liquid onto a medium to be discharged, in the uncapped state, causes the liquid ejection head to perform a discharge operation of discharging liquid from the nozzles onto the medium to be discharged, after completion of the discharge operation, controls the switching means to switch from the uncapped state to the capped state, thereby setting a standby state in which reception of the discharge instruction signal is awaited in the capped state, after completion of the discharge operation, before reaching the standby state, controls the liquid ejection head to perform pre-standby flushing for discharging liquid from the nozzles, in the pre-standby flushing, from among the plurality of nozzles forming the nozzle row, a terminal nozzle farthest from the supply port or a part of the nozzles including the terminal nozzle and continuously arranged in the one direction, discharges an amount of liquid corresponding to a pre-standby parameter related to the degree of drying of the liquid in the nozzles immediately before the pre-standby flushing, after completion of the discharge operation, before the pre-standby flushing, causes the liquid ejection head to perform pre-flushing for discharging liquid from the nozzles closer to the supply port than the nozzles from which liquid is discharged in the pre-standby flushing among the plurality of nozzles forming the nozzle row. A liquid ejection device characterized by this.

2. A liquid ejection head having nozzles, a cap covering the nozzles, switching means for switching between a capped state in which the nozzles are covered by the cap and an uncapped state in which the cap is separated from the liquid ejection head and the nozzles are exposed relative to the capped state, a control unit, and comprising, wherein the control unit, controls the liquid ejection head so as to discharge liquid toward the medium to be discharged from the nozzles, thereby causing a discharge operation for recording on a recording medium to be performed. Selectively perform recording on the medium to be ejected in either the first recording mode or the second recording mode that performs recording with higher image quality than the first recording mode. When receiving a discharge instruction signal for instructing the discharge of liquid onto the medium to be ejected, In the uncapped state, cause the ejection operation to be performed. After completion of the ejection operation, control the switching means to switch from the uncapped state to the capped state, thereby setting it to a standby state of waiting for reception of the discharge instruction signal in the capped state. After completion of the ejection operation and before reaching the standby state, control the liquid ejection head to perform pre-standby flushing for discharging liquid from the nozzles. In the pre-standby flushing, discharge an amount of liquid from the nozzles according to a pre-standby parameter related to the degree of drying of the liquid in the nozzles immediately before the pre-standby flushing. When receiving the discharge instruction signal in the standby state, When performing recording on the medium to be ejected in the second recording mode, cause the liquid ejection head to perform another flushing for discharging an amount of liquid from the nozzles according to a drying progress parameter related to the degree of progress of drying of the liquid in the nozzles in the capped state, and then perform the ejection operation. A liquid ejection apparatus characterized in that when a predetermined pre-discharge skip condition for performing recording on the medium to be ejected in the first recording mode is satisfied, the ejection operation is performed on the liquid ejection head without performing the other flushing.

3. A liquid ejection head having nozzles, A cap covering the nozzles, Switching means for switching between a capped state in which the nozzles are covered by the cap and an uncapped state in which the cap is separated from the liquid ejection head and the nozzles are exposed, A temperature sensor for detecting temperature, A control unit, comprising: The control unit: When receiving a discharge instruction signal for instructing the discharge of liquid onto the medium to be ejected, In the uncapped state, cause the liquid ejection head to perform an ejection operation of discharging liquid from the nozzles onto the medium to be ejected. After completion of the ejection operation, control the switching means to switch from the uncapped state to the capped state, thereby setting it to a standby state of waiting for reception of the discharge instruction signal in the capped state. After completion of the ejection operation, before entering the standby state, the liquid ejection head is controlled to perform pre-standby flushing to discharge liquid from the nozzles. In the pre-standby flushing, an amount of liquid corresponding to a pre-standby parameter related to the degree of drying of the liquid in the nozzle immediately before the pre-standby flushing is discharged from the nozzle. When the ejection instruction signal is received in the standby state If the pre-ejection temperature condition related to the temperature detected by the temperature sensor immediately before the ejection operation is not satisfied, another flushing is performed to discharge an amount of liquid corresponding to a drying progress parameter related to the degree of progress of drying of the liquid in the nozzle in the capped state from the nozzle, and then the ejection operation is performed. When a predetermined pre-ejection skip condition including the pre-ejection temperature condition is satisfied, the liquid ejection head is caused to perform the ejection operation without performing the other flushing. A liquid ejection device characterized by this.

4. A liquid ejection head having nozzles, A cap that covers the nozzles, Switching means for switching between a capped state in which the nozzles are covered with the cap and an uncapped state in which the cap is separated from the liquid ejection head and the nozzles are exposed, compared to the capped state, A humidity sensor for detecting humidity, A control unit, comprising: The control unit When receiving an ejection instruction signal for instructing ejection of liquid onto a medium to be ejected, In the uncapped state, causes the liquid ejection head to perform an ejection operation of ejecting liquid from the nozzles onto the medium to be ejected, After completion of the ejection operation, by controlling the switching means to switch from the uncapped state to the capped state, a standby state is set in which reception of the ejection instruction signal is awaited in the capped state. After completion of the ejection operation, before entering the standby state, the liquid ejection head is controlled to perform pre-standby flushing to discharge liquid from the nozzles. In the pre-standby flushing, an amount of liquid corresponding to a pre-standby parameter related to the degree of drying of the liquid in the nozzle immediately before the pre-standby flushing is discharged from the nozzle. When the ejection instruction signal is received in the standby state If the pre-discharge humidity condition related to the humidity detected by the humidity sensor immediately before the discharge operation is not satisfied, the liquid discharge head is caused to perform another flushing to discharge from the nozzle an amount of liquid corresponding to a drying progress parameter related to the degree of progress of drying of the liquid in the nozzle in the capped state, and then the discharge operation is performed. When a predetermined pre-discharge skip condition including the pre-discharge humidity condition is satisfied, the liquid discharge head is caused to perform the discharge operation without performing the other flushing. A liquid discharge apparatus characterized by this. **Claim 5** A liquid discharge head having a plurality of nozzles; A cap that covers the nozzles; Switching means for switching between a capped state in which the nozzles are covered by the cap and an uncapped state in which the cap is separated from the liquid discharge head and the nozzles are exposed, relative to the capped state; A control unit, comprising: The control unit: By controlling the liquid discharge head so as to discharge liquid from the nozzles toward the medium to be discharged, a discharge operation for recording on a recording medium is performed. Selectively recording on the medium to be discharged in either a first recording mode or a second recording mode in which recording is performed with higher image quality than the first recording mode. When recording on the medium to be discharged is performed in the second recording mode, the number of nozzles used for the discharge operation is smaller than when recording on the medium to be discharged is performed in the first recording mode. When a discharge instruction signal for instructing discharge of liquid onto the medium to be discharged is received, The discharge operation is performed in the uncapped state. After completion of the discharge operation, by controlling the switching means to switch from the uncapped state to the capped state, a standby state is set in which reception of the discharge instruction signal is awaited in the capped state. After completion of the discharge operation, before reaching the standby state, the liquid discharge head is controlled to perform pre-standby flushing to discharge liquid from the nozzles. In the pre-standby flushing, an amount of liquid corresponding to a pre-standby parameter related to the degree of drying of the liquid in the nozzles immediately before the pre-standby flushing is discharged from the nozzles. When performing recording on the ejected medium in the second recording mode, after completion of the ejection operation, before entering the standby state, the liquid ejection head is made to perform pre-standby flushing and another flushing for discharging from the nozzles an amount of liquid corresponding to a drying progress parameter related to the degree of progress of drying of the liquid in the nozzles in the capped state. When a predetermined post-ejection skip condition for performing recording on the ejected medium in the first recording mode is satisfied, after completion of the ejection operation, before entering the standby state, the liquid ejection head is made to perform pre-standby flushing and not to perform the other flushing. A liquid ejection apparatus characterized by this. A liquid ejection head having nozzles; A cap covering the nozzles; Switching means for switching between a capped state in which the nozzles are covered by the cap and an uncapped state in which the cap is separated from the liquid ejection head and the nozzles are exposed, relative to the capped state; A temperature sensor for detecting temperature; A control unit, provided with: The control unit: When receiving an ejection instruction signal for instructing ejection of liquid onto an ejected medium, In the uncapped state, causes the liquid ejection head to perform an ejection operation of ejecting liquid from the nozzles onto the ejected medium; After completion of the ejection operation, by controlling the switching means to switch from the uncapped state to the capped state, sets it to a standby state of waiting for reception of the ejection instruction signal in the capped state; After completion of the ejection operation, before entering the standby state, controls the liquid ejection head to perform pre-standby flushing for discharging liquid from the nozzles; In the pre-standby flushing, discharges from the nozzles an amount of liquid corresponding to a pre-standby parameter related to the degree of drying of the liquid in the nozzles immediately before the pre-standby flushing; When the ejection temperature condition related to the temperature detected by the temperature sensor during the ejection operation is not satisfied, after completion of the ejection operation, before entering the standby state, the liquid ejection head is made to perform pre-standby flushing and another flushing for discharging from the nozzles an amount of liquid corresponding to a drying progress parameter related to the degree of progress of drying of the liquid in the nozzles in the capped state. ​ When a predetermined post-discharge skip condition including the discharge temperature condition is satisfied, after completion of the discharge operation, before reaching the standby state, the liquid discharge head is caused to perform the pre-standby flushing and not to perform the other flushing. A liquid discharge apparatus characterized by this.

7. A liquid discharge head having nozzles, A cap covering the nozzles, Switching means for switching between a cap state in which the nozzles are covered by the cap and an uncapped state in which the cap is separated from the liquid discharge head and the nozzles are exposed from the cap state, A humidity sensor for detecting humidity, A control unit, comprising: The control unit, When receiving a discharge instruction signal for instructing discharge of liquid onto a medium to be discharged, In the uncapped state, causes the liquid discharge head to perform a discharge operation of discharging liquid from the nozzles onto the medium to be discharged, After completion of the discharge operation, by controlling the switching means to switch from the uncapped state to the cap state, it is set to a standby state of waiting for reception of the discharge instruction signal in the cap state, After completion of the discharge operation, before reaching the standby state, controls the liquid discharge head to perform pre-standby flushing for discharging liquid from the nozzles, In the pre-standby flushing, an amount of liquid corresponding to a pre-standby parameter related to the degree of drying of the liquid in the nozzles immediately before the pre-standby flushing is discharged from the nozzles, When the discharge humidity condition related to the humidity detected by the humidity sensor during the discharge operation is not satisfied, after completion of the discharge operation, before reaching the standby state, the liquid discharge head is caused to perform the pre-standby flushing and another flushing for discharging an amount of liquid corresponding to a drying progress parameter related to the degree of progress of drying of the liquid in the nozzles in the cap state from the nozzles, When a predetermined post-discharge skip condition including the discharge humidity condition is satisfied, after completion of the discharge operation, before reaching the standby state, the liquid discharge head is caused to perform the pre-standby flushing and not to perform the other flushing. A liquid discharge apparatus characterized by this.

8. The pre-standby parameter includes an uncapped parameter that is a value corresponding to the length of the uncapped time, which is the time for which the uncapped state continues, The control unit, The liquid ejection apparatus according to any one of claims 1 to 7, wherein in the pre-wait flushing, the longer the uncapping time indicated by the value of the uncapping parameter, the greater the amount of liquid discharged from the nozzle.

9. comprising a temperature sensor for detecting temperature, The liquid ejection apparatus according to any one of claims 1 to 8, wherein the pre-wait parameter includes a parameter related to the temperature detected by the temperature sensor during the ejection operation.

10. comprising a humidity sensor for detecting humidity, The liquid ejection apparatus according to any one of claims 1 to 9, wherein the pre-wait parameter includes a parameter related to the humidity detected by the humidity sensor during the ejection operation.

11. The liquid ejection apparatus according to any one of claims 2 to 7, wherein the drying progress parameter includes a parameter related to the elapsed time since the last flushing was performed.

12. comprising a temperature sensor for detecting temperature, The liquid ejection apparatus according to any one of claims 2 to 7, 11, wherein the drying progress parameter includes a parameter related to the temperature detected by the temperature sensor in the standby state.

13. comprising a humidity sensor for detecting humidity, The liquid ejection apparatus according to any one of claims 2 to 7, 11, wherein the drying progress parameter includes a parameter related to the humidity detected by the humidity sensor in the standby state.

14. a liquid ejection head having a nozzle, a cap covering the nozzle, switching means for switching between a capped state in which the nozzle is covered by the cap and an uncapped state in which the cap is separated from the liquid ejection head and the nozzle is exposed, a control unit, and comprising, The control unit, when receiving a discharge instruction signal for instructing the discharge of liquid onto the medium to be discharged, in the uncapped state, causing the liquid ejection head to perform a discharge operation of discharging liquid from the nozzle onto the medium to be discharged, after completion of the discharge operation, by controlling the switching means to switch from the uncapped state to the capped state, putting it in a standby state of waiting for reception of the discharge instruction signal in the capped state, after completion of the discharge operation, before reaching the standby state, controlling the liquid ejection head to perform pre-wait flushing of discharging liquid from the nozzle. In the pre-wait flushing, an amount of liquid corresponding to a pre-wait parameter related to the degree of drying of the liquid in the nozzle immediately before the pre-wait flushing is discharged from the nozzle. After completion of the discharging operation, before entering the standby state, the liquid discharge head is controlled to perform pre-wait flushing for discharging liquid from the nozzle. During the standby state, the liquid discharge head is not controlled to discharge liquid from the nozzle. When the discharge instruction signal is received in the standby state, if a predetermined condition is satisfied, another flushing different from the pre-wait flushing is performed, and then the discharging operation is performed. If the predetermined condition is not satisfied, the discharging operation is performed without performing the another flushing. A liquid discharge apparatus characterized by this.

15. The control unit When performing the another flushing, the liquid discharge head discharges an amount of liquid corresponding to a drying progress parameter related to the degree of progress of drying of the liquid in the nozzle in the cap state from the nozzle. The liquid discharge apparatus according to claim 14, characterized by this.

Images