JP2017209865A - Liquid discharge device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate thickening of liquid in a nozzle by appropriately vibrating the liquid according to time during which a carriage is stopped between one scan printing and subsequent scan printing.SOLUTION: In scan printing, ink is discharged to an inkjet head through a plurality of nozzles while moving a carriage at constant speed, in a discharge zone K0. In an acceleration zone adjacent to an upstream side of the discharge zone K0 in a moving direction of the carriage in the scan printing, the inkjet head is driven so that ink is not discharged through the nozzles to vibrate ink in the nozzles while accelerating the carriage 2. In a deceleration zone adjacent to the upstream side of the discharge zone K0 in the moving direction of the carriage in the scan printing, the carriage is decelerated and then stopped. Time Tw during which the carriage is stopped between one scan printing and subsequent scan printing is calculated, and as the calculated time Tw is longer, a stopping position of the carriage in the one scan printing is set at a position closer to outside in a scanning direction.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a liquid ejecting apparatus that ejects liquid from a nozzle.

  In the ink jet printer device described in Patent Document 1, the recording head has a plurality of nozzles and is mounted on a carriage that can reciprocate in the scanning direction. When the carriage moves in one direction at a constant speed, ink is ejected from a plurality of nozzles in synchronization with this. The carriage movement operation with the ink ejection operation is repeated, and printing on the recording medium is performed. With respect to the scanning direction, both sides of the area (printing area) where the ink ejection operation is performed are non-printing areas, and the carriage is accelerated or decelerated. The recording head in this area is driven, but only the meniscus is oscillated and no ink is ejected.

JP 2007-160819

  In the ink jet printer device described in Patent Document 1, there is a case where the carriage stop time from the completion of the carriage movement operation to the start of the next carriage movement operation may be different. In particular, as an example in which the stop time becomes long, there are a case where the transfer speed of print data is low, a size of print data is large, a duty of an image to be printed is high, and the like. When the resolution and gradation of the image to be printed are high, the size of the print data increases, and it takes time to transfer the data. If the printing duty of the image is high, the pressure fluctuation in the ink becomes large, and it takes time to wait until it is attenuated to some extent.

  The longer the stop time, the more the ink thickens in the vicinity of the nozzle. In order to suppress this, the above-described vibration of ink in the nozzle (meniscus vibration) is effective, but if this is performed uniformly, a problem may occur. For example, when the stop time is longer than expected, the ink is not sufficiently stirred only by a predetermined meniscus vibration, and the ink thickening cannot be sufficiently eliminated. On the other hand, when the stop time is short, the ink in the nozzle is vibrated more than necessary, and power is wasted.

  An object of the present invention is to provide a liquid ejecting apparatus that can appropriately vibrate the liquid in the nozzle in accordance with the length of the stop time and eliminate the thickening of the liquid in the nozzle.

  According to a first aspect of the present invention, there is provided a liquid ejection apparatus that moves the carriage in a carriage movement section defined by stop positions on both sides with respect to the scanning direction, a liquid ejection head having a nozzle, a carriage on which the liquid ejection head is mounted, and the scanning direction. A carriage movement mechanism, an encoder that detects the position of the carriage in the scanning direction, and a control device that controls the liquid ejection head and the carriage movement mechanism, wherein the control device is on one side of the carriage movement section. An acceleration section for accelerating the carriage from the stop position on one side with respect to a carriage movement for moving the carriage from the stop position on the other side to a discharge section for discharging liquid from the nozzle, and Position of the deceleration section that decelerates the carriage to the stop position on the other side Set and vibrate so as not to discharge the liquid in the nozzle by driving the liquid discharge head every time the encoder count increases in the acceleration section, and the positions of the acceleration section and the deceleration section Is set, the stop time of the carriage from the completion of a certain carriage movement to the start of the next carriage movement is calculated. The longer the stop time, the more the one of the next carriage movements The stop position on the side is set to a position outside the scanning direction.

  In the present invention, the longer the stop time of the carriage, the one stop position in the next carriage movement is set to the outer position in the scanning direction. Thereby, the acceleration section in the next carriage movement becomes longer. As a result, at the time of the next carriage movement, the number of times the liquid in the nozzle is vibrated in the acceleration section can be increased to reliably eliminate the thickening of the liquid in the nozzle. On the other hand, when the stop time is short, the stop position on one side is positioned more inside in the scanning direction in the next carriage movement. Thereby, at the time of the next carriage movement, the acceleration section is shortened, and unnecessary vibration of the liquid does not have to be performed.

  The liquid ejection apparatus according to a second aspect is the liquid ejection apparatus according to the first aspect, wherein the control unit drives the liquid ejection head each time the count number of the encoder increases, thereby causing the deceleration zone And vibrate so as not to discharge the liquid in the nozzle.

  In the present invention, since the liquid in the nozzle is vibrated even when the carriage is decelerated, the thickening of the liquid in the nozzle can be more efficiently eliminated.

  A liquid ejection device according to a third aspect of the invention is the liquid ejection device according to the first or second aspect, further comprising a humidity sensor for detecting the humidity around the device, wherein the control device includes the acceleration section and the acceleration section. When the position of the deceleration section is set, the stop position on the one side in the next carriage movement is set closer to the outer side in the scanning direction as the signal from the humidity sensor indicates that the humidity is lower. Set to position.

  The lower the humidity around the device, the easier the liquid in the nozzle thickens. In the present invention, the lower the humidity around the apparatus is, the more the carriage stop position is set to the outer position in the scanning direction in the acceleration period of the next carriage movement. Thereby, since the length of the acceleration section of the next carriage movement becomes longer, the number of times that the liquid in the nozzle is vibrated can be increased accordingly. As a result, when the liquid in the nozzle tends to thicken, the thickening of the liquid in the nozzle can be reliably eliminated.

  According to a fourth aspect of the present invention, there is provided the liquid ejection device according to any one of the first to third aspects, wherein the control device moves the carriage in the acceleration section according to the stop time. After accelerating to a speed faster than the speed in the discharge section, the speed is decelerated to the speed in the discharge section.

  In the present invention, the carriage is accelerated to a speed faster than the speed in the discharge section in the acceleration section according to the stop time, and then decelerated to the speed in the discharge section. As a result, when the stop time is long, the period in which the liquid in the nozzle is vibrated in the acceleration section (the liquid discharge head drive period in the acceleration section) is shortened, and the thickening of the liquid in the nozzle is reliably eliminated. be able to. On the other hand, when the stop time is short, the period in which the liquid in the nozzle is vibrated in the acceleration section (the liquid ejection head drive period in the acceleration section) is lengthened so that the liquid in the nozzle is not vibrated more than necessary. can do.

  A liquid ejection apparatus according to a fifth aspect of the present invention includes a liquid ejection head having a nozzle, a carriage on which the liquid ejection head is mounted, a carriage moving mechanism that moves the carriage in the scanning direction, and a position of the carriage in the scanning direction. And a control device that controls the liquid ejection head and the carriage movement mechanism, and the control device moves the carriage in one carriage movement that moves the carriage in the scanning direction. The carriage is accelerated in an acceleration section located upstream from a discharge section for discharging liquid from the nozzle, and the carriage is decelerated in a deceleration section located downstream from the discharge section. Each time the encoder count increases, the liquid ejection head is driven. By virtue of this, the liquid in the nozzle is vibrated so as not to be discharged, and in the next carriage movement according to the carriage stop time from the completion of a certain carriage movement to the start of the next carriage movement. In the acceleration section, the carriage is accelerated to a speed faster than the speed in the discharge section, and then decelerated to the speed in the discharge section.

  In the present invention, the carriage is accelerated to a speed faster than the speed in the discharge section in the acceleration section according to the stop time, and then decelerated to the speed in the discharge section. As a result, when the stop time is long, the period in which the liquid in the nozzle is vibrated in the acceleration section (the liquid discharge head drive period in the acceleration section) is shortened, and the thickening of the liquid in the nozzle is reliably eliminated. be able to. On the other hand, when the stop time is short, the period in which the liquid in the nozzle is vibrated in the acceleration section (the liquid ejection head drive period in the acceleration section) is lengthened so that the liquid in the nozzle is not vibrated more than necessary. can do.

  The liquid ejection device according to a sixth aspect of the present invention is the liquid ejection device according to the fourth or fifth aspect of the present invention, wherein the control device is configured so that the longer the stop time, the longer the stop period, The peak value of the carriage speed is set high.

  In the present invention, the longer the stop time, the higher the peak value of the carriage speed in the acceleration section. Thereby, the period which vibrates the liquid in a nozzle becomes short, so that stop time is long. As a result, when the stop time is long, the period in which the liquid in the nozzle is vibrated in the acceleration section can be shortened, and the thickening of the liquid in the nozzle can be reliably eliminated. On the other hand, when the stop time is short, the period in which the liquid in the nozzle is vibrated in the acceleration section can be lengthened so that the liquid in the nozzle is not vibrated more than necessary.

  A liquid ejection apparatus according to a seventh aspect is the liquid ejection apparatus according to any one of the fourth to sixth aspects, wherein the control device is faster than the speed of the carriage in the ejection section in the acceleration section. The magnitude of the acceleration of the carriage when accelerating to the speed is made larger than the magnitude of the acceleration of the carriage when the carriage is subsequently decelerated to the speed in the discharge section.

  In the present invention, the change in the moving speed of the carriage at a position close to the discharge section can be moderated. Thereby, it is possible to suppress the shaking of the liquid in the liquid discharge head when the discharge of ink from the nozzle is started.

  The liquid ejection apparatus according to an eighth aspect of the present invention is the liquid ejection apparatus according to any one of the fourth to sixth aspects, wherein the control device is faster than the speed of the carriage in the ejection section in the acceleration section. The magnitude of the acceleration of the carriage when accelerating to a speed is made smaller than the magnitude of the acceleration of the carriage when the carriage is subsequently decelerated to the speed in the ejection section.

  In the present invention, when the liquid in the nozzle is vibrated in the acceleration section, the carriage moving speed can be increased as much as possible near the discharge section. Thereby, the period which vibrates the liquid in a nozzle in the position close | similar to a discharge area becomes short. When the vibration period is short, the effect of eliminating thickening is high. As a result, for example, when the liquid is easy to thicken, the liquid in the nozzle is vibrated in a short period immediately before the ink discharge from the nozzle is started, thereby increasing the viscosity of the liquid in the nozzle. It can be eliminated.

  A liquid ejection apparatus according to a ninth aspect is the liquid ejection apparatus according to any one of the fourth to eighth aspects, wherein the drive frequency of the liquid ejection head is equal to the resonance frequency of the liquid flow path in the liquid ejection head. The resonance speed that is the speed of the carriage is faster than the speed of the carriage in the ejection section, and the control device accelerates the carriage to a speed equal to or higher than the resonance speed in the acceleration section. To decelerate to the speed in the discharge section.

  In the present invention, while the carriage is accelerated in the acceleration section, the drive frequency of the liquid discharge head changes in a range including the resonance frequency of the liquid flow path of the liquid discharge head. Thereby, the liquid in a nozzle can be vibrated efficiently.

A liquid ejection apparatus according to a tenth aspect of the invention is the liquid ejection apparatus according to any one of the fourth to ninth aspects, wherein the control device sets the stop time when the stop time is longer than a predetermined time. Accordingly, in the next carriage movement, in the acceleration section, the carriage is accelerated to a speed faster than the speed in the discharge section and then decelerated to the speed in the discharge section.
When the stop time is equal to or shorter than the predetermined time, in the next carriage movement, in the acceleration section, the speed in the discharge section is not accelerated to a speed higher than the speed in the discharge section. To speed up.

  According to the present invention, it is possible to prevent the liquid in the nozzle from vibrating more than necessary when the stop time is short.

  According to an eleventh aspect of the present invention, in the liquid discharge apparatus according to any one of the fourth to tenth aspects, the control device moves the carriage in the deceleration section faster than the speed in the discharge section. After accelerating to a high speed and decelerating, the liquid in the nozzle is vibrated without being discharged.

  According to the present invention, in the deceleration section, the liquid in the nozzle is increased by accelerating the carriage to a speed higher than the speed in the discharge section and then decelerating to the speed in the discharge section and vibrating the liquid in the nozzle. Viscosity can be eliminated efficiently.

  A liquid discharge apparatus according to a twelfth aspect of the present invention is the liquid discharge apparatus according to any one of the fourth to eleventh aspects of the present invention, further comprising a humidity sensor for detecting the humidity around the apparatus, As the signal from the humidity sensor indicates that the humidity is lower, the peak speed value of the carriage in the acceleration section is set higher.

  The lower the humidity around the device, the easier the liquid in the nozzle thickens. In the present invention, the lower the humidity around the apparatus, the higher the peak value of the carriage speed in the acceleration section in the next carriage movement. Thereby, when the liquid in a nozzle tends to thicken, the thickening of the liquid in a nozzle can be eliminated reliably.

  A liquid ejection apparatus according to a thirteenth aspect of the present invention is a liquid ejection head having a nozzle, a carriage on which the liquid ejection head is mounted, a carriage moving mechanism that moves the carriage in the scanning direction, and a position of the carriage in the scanning direction. And a control device that controls the liquid ejection head and the carriage movement mechanism, and the control device moves the carriage in one carriage movement that moves the carriage in the scanning direction. The carriage is accelerated in an acceleration section located upstream from a discharge section for discharging liquid from the nozzle, and the carriage is decelerated in a deceleration section located downstream from the discharge section. Each time the encoder count increases, the liquid discharge head is By oscillating, the liquid in the nozzle is vibrated so as not to be discharged, and in the acceleration section, the carriage is accelerated to a speed faster than the speed in the discharge section, and then to the speed in the discharge section. Decelerate.

  In the present invention, in the acceleration section, the carriage is accelerated to a speed faster than the speed in the discharge section, and then decelerated to the speed in the discharge section. Accordingly, when the liquid in the nozzle is vibrated in the acceleration section, the period for vibrating the liquid in the nozzle is shortened. Thereby, the thickening of the liquid in a nozzle can be eliminated efficiently.

  According to the present invention, the liquid in the nozzle can be appropriately vibrated according to the carriage stop time during the carriage movement, and the thickening of the liquid in the nozzle can be eliminated.

1 is a schematic configuration diagram of a printer according to a first embodiment. FIG. 2 is a block diagram illustrating an electrical configuration of the printer of the first embodiment. 4 is a flowchart illustrating a flow of processing when printing is performed in the printer of the first embodiment. (A) is a diagram showing the position of each section when the stop time Tw is Tw1, and (b) shows the position of each section when the stop time Tw is Tw2 when the carriage moves to the right side. FIG. (A) is a figure which shows the time change of the carriage moving speed when the stop time Tw is Tw1, and (b) is the figure which shows the time change of the carriage moving speed when the stop time Tw is Tw2. is there. It is a flowchart which shows the flow of control of the inkjet head in scan printing. It is a flowchart equivalent to FIG. 3 of 2nd Embodiment. It is a figure which shows the relationship between the position of a scanning direction when a carriage moves to the right side in 2nd Embodiment, and the moving speed of a carriage, (a) is (b) when stop time Tw is Tw1. The case where the stop time Tw is Tw2 is shown. FIG. 8A is a diagram corresponding to FIG. 8A of the first modification, and FIG. 8B is a diagram corresponding to FIG. 8B of the first modification. FIG. 8A is a diagram corresponding to FIG. 8A of the second modification, and FIG. 8B is a diagram corresponding to FIG. 8B of the second modification.

[First Embodiment]
Hereinafter, a preferred first embodiment of the present invention will be described.

(Entire printer configuration)
As shown in FIG. 1, the printer 1 according to the first embodiment (“liquid ejection device” of the present invention) includes a carriage 2, an inkjet head 3 (“liquid ejection head” of the present invention), transport rollers 4, 5, A platen 6 is provided.

  The ink jet head 3 is mounted on the carriage 2. The carriage 2 is supported by a carriage moving mechanism and reciprocates in the scanning direction together with the inkjet head 3. As shown in FIG. 1, the carriage moving mechanism includes two guide rails 11 and 12, two pulleys 13 and 14, an endless belt 15, and a carriage motor 16. Opposite to. The two guide rails 11 and 12 extend along the main scanning direction and support the carriage 2 so as to be movable. The guide rail 12 is provided with pulleys 13 and 14 at both ends, and a belt 15 is wound around the two pulleys 13 and 14. Since the carriage 2 is attached to the belt 15 and the pulley 13 is connected to the carriage motor 16, when the carriage motor 16 is driven, the belt 15 travels and the carriage 2 moves along the guide rails 11 and 12. To do.

  The printer 1 also includes a linear encoder 17 for detecting the position of the carriage 2 in the scanning direction. The linear encoder 17 includes an encoder belt 21 and an encoder sensor 22. The flat plate member encoder belt 21 is erected on the upper surface of the guide rail 12 and extends in the scanning direction. The encoder belt 21 has slits formed at equal intervals. The encoder sensor 22 is attached to the carriage 2 and faces the slit forming surface of the encoder belt 21 with a predetermined interval. As the carriage 2 moves, the encoder sensor 22 counts the number of slits that cross the front. Thereby, the position of the carriage 2 in the scanning direction is detected. In addition, since the linear encoder 17 is a well-known thing, the detailed description beyond this is abbreviate | omitted here. In the following description, the right side and the left side in the scanning direction are defined as shown in FIG.

  The lower surface of the inkjet head 3 is located between the two guide rails 11 and 12 and faces the recording paper P being conveyed. The lower surface is an ejection surface on which a plurality of nozzles 10 are formed. The plurality of nozzles 10 includes four nozzle groups. A predetermined number of nozzles 10 are arranged in the scanning direction of the carriage 2, forming a nozzle row 9 side by side in the conveyance direction of the recording paper P. In FIG. 1, black, yellow, cyan, and magenta inks are ejected in order from the right nozzle row 9.

  The transport rollers 4 and 5 are arranged with the carriage 2 and the platen 6 sandwiched in the transport direction. The transport rollers 4 and 5 are driven by a transport motor 18 (see FIG. 2) to transport the recording paper P in the transport direction. The platen 6 is a flat plate member and has a quadrangular planar shape. With respect to the scanning direction, the width of the platen 6 is slightly wider than the moving range of the carriage 2 for printing characters. The platen 6 faces the lower surface of the inkjet head 3 and supports the recording paper P being conveyed from below.

(Control device)
As shown in FIG. 2, the printer 1 includes a humidity sensor 19, a control device 50, and the like in addition to the above configuration. The humidity sensor 19 is for detecting the humidity around the printer 1. The control device 50 includes a CPU (Central Processing Unit) 51, a ROM (Read Only Memory) 52, a RAM (Random Access Memory) 53, an EEPROM (Electrically Erasable Programmable Read Only Memory) 54, an ASIC (Application Specific Integrated Circuit) 55, and the like. These control the operations of the carriage motor 16, the ink jet head 3, the transport motor 18, and the like. Further, signals are input from the encoder sensor 22 and the humidity sensor 19 to the control device 50.

  Here, as shown in FIG. 2, one CPU 51 and one ASIC 55 collectively perform corresponding processes. However, the configuration of the control device 50 is not limited to this, and may be a configuration in which processing is shared by a plurality of CPCs 51. In addition, the control device 50 may be configured to share processing with a plurality of ASICs 55.

(Control during printing)
Next, an operation for printing on the recording paper P by the printer 1 will be described. In the printer 1, color printing is performed on the recording paper P by alternately repeating scan printing (“carriage movement” in the present invention) and conveying operation. In scan printing, the carriage 2 is moved in the scanning direction while ejecting ink. Ink ejection is performed in a constant speed movement section (a later-described ejection section K0) of the carriage 2, and is synchronized with the output of the encoder 17. One strip image is formed by one scan printing. In the transport operation, the transport rollers 4 and 5 are driven, and the recording paper P is fed by the width of the image (for example, the length of the nozzle row 9). During this time, the carriage 2 does not move.

  Control of the control device 50 will be described. In the first embodiment, the input print data is processed along the flow of FIG.

  Specifically, the control device 50 first calculates a stop time Tw of the carriage 2 from the completion of the scan printing to the start of the next scan printing (S101). The stop time Tw is an estimated value calculated based on the transfer speed of print data to the printer 1, the amount of print data, the duty in scan printing, and the like.

  For example, if the print data transfer speed is low, it takes a longer time to complete the transfer of necessary data. Even if the data transfer speed is not slow, the same applies if the print data size is large. Further, the previous ink ejection operation itself may prolong the stop time Tw. When the printing duty is high, pressure fluctuations remain in the ink. This may cause the image quality to change. This pressure fluctuation is attenuated to some extent over time. In addition, since high duty printing supplies a large amount of moisture to the recording paper P, it is necessary to increase the drying time. Both are events after scan printing, and the meniscus is dried while being open to the atmosphere.

  Next, the control device 50 sets a stop position for decelerating and stopping the carriage 2 in scan printing (S102). At this time, the control device 50 moves the stop position after the deceleration of the carriage 2 away from the end of the discharge section K0 as the stop time Tw calculated in S101 is longer. The stop position is more outside in the scanning direction than when the stop time Tw is short.

  By the way, the scan printing starts from the stop position of the carriage 2 on one side and ends at the stop position on the opposite side in the scanning direction. The range defined by the stop positions on both sides is the “carriage movement section” of the present invention. As shown in FIG. 4, the carriage movement section includes three sections, ie, an acceleration section on one side (upstream side) and a deceleration section on the opposite side (downstream side) with the discharge section K0 in the center portion interposed therebetween. In the discharge section K0, the carriage 2 is moved at a constant speed Vt at a constant speed. The inkjet head 3 is driven and ink is ejected. In the acceleration section, the carriage 2 is accelerated from the stop state to the speed Vt. The speed of the carriage 2 increases monotonously up to the speed Vt. The ink jet head 3 is driven in a non-ejection manner (the meniscus vibrates). In the deceleration zone, the carriage monotonously decreases from the speed Vt and stops at the end of the zone.

  In the present embodiment, a bidirectional printing method is adopted. Scan printing is performed in a reciprocating manner in the scanning direction. Therefore, the carriage 2 moves in the reverse direction in two consecutive scan printings. A deceleration section of a certain scan printing is an acceleration section of the next scan printing.

  FIG. 4 shows the relationship between the carriage position and the carriage speed. In scan printing in which the carriage 2 moves to the right side, a section K2 adjacent to the left side is an acceleration section with respect to the central discharge section K0 shown in FIG. The right section K1 is a deceleration section. At this time, the left end of the section K2 is the “stop position on one side” of the present invention, and the right end of the section K1 is the “stop position on the other side” of the present invention. On the other hand, in the scan printing in which the carriage 2 moves to the left side, the positional relationship such as the section related to the discharge section K0 is reversed. The section K2 is a deceleration section, and the left end thereof is the “stop position on the other side” of the present invention. The section K1 is an acceleration section, and its right end is the “stop position on one side” of the present invention.

FIG. 5 shows the relationship between the elapsed time and the carriage speed. As shown in FIG. 5, the stop time Tw is Tw1. In the case of scan printing in which the carriage 2 moves to the right, as shown in FIG. 4A, the deceleration section (the corresponding section is K1) has the section width W11 and the stop position is the position U11. At this time, in the next scan printing that starts with the stop time Tw1 interposed therebetween, the position U11 becomes the acceleration start position of the carriage 2. The carriage 2 is accelerated to the speed Vt using the section K1 having the section width W11.
On the other hand, when the stop time Tw is calculated as Tw2 (> Tw1), as shown in FIG. 4B, the deceleration width of a certain scan printing (the corresponding section is K1) has a section width of W12 ( > W11), the stop position is set as position U12. With respect to the scanning direction, the position U12 is on the right side of the position U11. Therefore, in some scan printing, the deceleration section becomes long. As shown in FIG.5 (b), the time until a stop also becomes long. In the next scan printing, the meniscus vibration frequency increases because it has a long acceleration interval.

  Even in scan printing in which the carriage 2 moves to the left side, the left-right positional relationship is reversed, but the explanation can be made in the same manner as described above.

  In S <b> 102, the control device 50 adjusts the stop position of the carriage 2 based on the humidity-related signal from the humidity sensor 19. The stop position is set to the outside in the scanning direction as the signal indicates lower humidity.

  Next, the control device 50 controls the carriage motor 16 to drive the inkjet head 3 while moving the carriage 2 in the scanning direction, and executes a scan printing process for performing the scan printing (S103).

  In scan printing, the carriage 2 starts moving from the starting point (stop position on one side). When the carriage 2 moves, the encoder 17 outputs a detection signal for each slit that crosses. The control device 50 counts this signal to know the position of the carriage 2. Based on this position information, the control device 50 controls the carriage 2 and the inkjet head 3.

  The operation in one scan printing (scan printing process; corresponding to S103 in FIG. 3) will be described with reference to the flowchart in FIG. In the present embodiment, when print data is input, the recording paper P is fed out from the paper feed tray. The conveyance is a center cash register method. The center of the carriage movement section overlaps the center of the recording paper P in the scanning direction. When the leading edge of the recording paper P is detected at a predetermined position, the conveyance is temporarily stopped after a predetermined time. One piece of data for scan printing is prepared so far. At this time, the stop position of the deceleration zone and the stop time Tw after the stop are also set.

  Simultaneously with the conveyance stop, the carriage 2 starts to move (S201). It is the start of some scan printing. The control device 50 controls the carriage motor 16 to accelerate the carriage 2 at a predetermined acceleration (S202), and controls the inkjet head 3 to drive it in a non-ejection (S203). At this time, the meniscus of the nozzle 10 vibrates in synchronization with the encoder output. In this acceleration section, the vibration period decreases monotonously. The acceleration of the carriage 2 and the non-ejection driving of the inkjet head 3 continue until the control device 50 counts N1 as the slit count (S204: N).

  When the count number = N1 is counted (S204: Y), the control device 50 controls the carriage motor 16 to stop acceleration. It is the end of the acceleration interval and the beginning of the subsequent discharge interval. From here, the carriage 2 is moved at a constant speed (predetermined speed Vt) at the time of acceleration stop (S205). A detection signal is periodically output from the encoder 17. In synchronization with this, the inkjet head 3 is driven. The ink ejection timing is based on the print data (one scan print data) (S206). The carriage 2 is moved at a constant speed and the inkjet head 3 is driven for ejection until the control device 50 counts N2 as the slit count (S207: N).

  When the count number = N2 is counted (S207: Y), the control device 50 controls the carriage motor 16 to start deceleration. It is the end of the discharge section and the start of the subsequent deceleration section. The control device 50 decelerates the carriage 2 at a constant acceleration (S208). The deceleration continues until the control device 50 counts N3 as the slit count (S210: N). During this time, the inkjet head 3 is kept in a standby state (S209).

  When the count number = N3 is counted (S210: Y), the carriage 2 is at the end point of the deceleration zone (the stop position on the other side), and the control device 50 stops the carriage motor 16 (S211). At this time, the control device 50 determines whether or not the next scan printing is performed (S212; corresponding to S104 in FIG. 3). If there is no next scan printing, the control device 50 determines that printing on one recording sheet P (all scan printing) is completed (S212: N; equivalent to S104: N in FIG. 3), and the next recording Wait for paper P to arrive. When there is the next scan printing (S212: Y; equivalent to S104: Y in FIG. 3), the control device 50 moves the recording paper P by a predetermined distance (for example, a distance corresponding to the nozzle row length) (S213; FIG. 3). In step S105) to prepare for the next scan printing. While waiting for the completion of the movement of the recording paper P, the next scan print data, the next stop position, and the next stop time Tw are set.

  The control device 50 measures the staying time of the carriage 2 at the stop position together with the start of conveyance in S213. If the stay time is less than the stop time Tw (S214: N), the carriage 2 continues to stay. When the stay time reaches the stop time Tw (S214: Y), if the recording paper P is being conveyed, the completion is waited (S215: N).

  On the other hand, when the conveyance of the recording paper P is completed (S215: Y), the control device 50 instructs to reverse the moving direction of the carriage 2 (S216). As a result, the carriage motor 16 rotates in the reverse direction to the previous scan printing (S201). This is the start of the next scan print following a scan print.

  When printing on one recording paper P is completed (S212: N; equivalent to S104: Y in FIG. 3), the recording paper P is conveyed toward a paper discharge tray (not shown) (FIG. 3). Equivalent to S106). At this time, if all the printings instructed by the print data are completed, the entire printer 1 is set in a standby state and waits for the next print data to be input. The conveying operation of the recording paper P is stopped, and the inkjet head 3 is sealed with a cap.

  In general, if the ink jet head 3 does not eject ink, the ink viscosity increases in the nozzle 10 over time. Sometimes, the ink ejection characteristics deteriorate, and the resulting image quality decreases.

  Therefore, in the present embodiment, the ink in the nozzles 10 is vibrated without ejecting ink from the nozzles 10 in the scan printing acceleration section. Thereby, it is possible to eliminate the thickening of the ink before the ejection driving based on the print data.

  In the present embodiment, the encoder 17 detects slits arranged at equal intervals. In the acceleration section, non-ejection driving is performed in synchronization with the encoder output. When the acceleration section length is fixed, the non-ejection driving is insufficient for eliminating the thickening when the humidity is low or the stop time Tw is prolonged. On the other hand, if the humidity is high or the stop time Tw is short, the non-ejection drive becomes excessive. Wasteful power is consumed.

  Therefore, in the first embodiment, the length of the deceleration section (acceleration section of the next scan printing) is adjusted in a certain scan printing. The longer the stop time Tw and the lower the humidity, the longer the section length. In the next scan printing, the number of counts in the acceleration section increases and the number of meniscus vibrations increases. The shorter the stop time Tw and the higher the humidity, the shorter the section length. In the next scan printing, the number of counts in the acceleration section decreases, and the number of meniscus vibrations also decreases. In either case, the increase in the viscosity of the ink is eliminated without excess or deficiency.

[Second Embodiment]
Next, a preferred second embodiment of the present invention will be described. However, in the second embodiment, control at the time of printing is only different from that in the first embodiment. In the first embodiment, the acceleration section length of a certain scan printing is adjusted according to the stop time Tw and the humidity. In the second embodiment, each section length is fixed. The acceleration section is characterized in that the carriage 2 has a peak speed Vp (> Vt: speed in the discharge section).

  Control during printing will be described with reference to FIGS. Until the recording paper P is temporarily stopped at a predetermined position, scan printing data is prepared, and the peak speed Vp in the acceleration section is also set in advance (S301). For example, Vp = Vp1. At this time, the peak speed Vp may be adjusted based on the humidity.

  When the recording paper P arrives at a predetermined position, the first scan printing starts (S302). The operations of the carriage 2 and the inkjet head 3 in the discharge section and the deceleration section are as described above. In the acceleration section, the speed has a maximum point (in this case, Vp1 (> Vt)). When the count number = N3 is counted, the control device 50 stops the carriage motor 16 and determines the presence or absence of the next scan printing (S303).

  If there is a next scan printing (S303: Y), the control device 50 starts to move the recording paper P, measure the elapsed time from the completion of the previous scan printing, and prepare the next scan print data. (S304 and S305). While waiting for the completion of movement of the recording paper P, data for the next scan printing is prepared, and a stop time Tw (≧ movement time of the recording paper P) until the next scan printing is set. The scan printing data includes the peak speed Vp in the next scan printing. The stop time Tw is set by adding the adjustment amount due to the print duty and humidity at the time of the previous scan printing to the movement time of the predetermined distance of the recording paper P.

  Further, it waits for the elapsed time to become the stop time Tw (S306: N). When the elapsed time reaches the stop time Tw (S306: Y), the process is returned to S302, and the next scan printing is started.

  If there is no next scan printing (S303: N), the control device 50 waits for the arrival of the next recording sheet P. When all the printings instructed by the print data are completed, the entire printer 1 is put into a standby state, and the next print data is input. In either case, the printed recording paper P is conveyed toward a paper discharge tray (not shown) (S307).

  FIG. 8 shows a velocity profile with respect to the position of the carriage 2. In the middle of the acceleration section, the carriage 2 shifts from acceleration to deceleration. The acceleration α (+) during acceleration up to the maximum point of velocity is larger than the acceleration α (−) during deceleration from the maximum point. FIG. 8A corresponds to the case of staying at the stop position for the stop time Tw1. For example, there is a case where there is no influence due to the print duty and humidity during the first scan printing. FIG. 8B corresponds to the case of staying for the stop time Tw2 (> Tw1). For example, there is a case where there is an influence due to printing duty and humidity. When adjustment is made to the stop time Tw, the speed of the maximum point is set to the corresponding peak speed Vp = Vp2 (> Vp1).

  Here, with respect to the acceleration in the acceleration section, at a position where α (+) = α (−), θ1 = θ2 holds for the angle θ (see FIG. 8) formed by the velocity profile and the horizontal axis. In the present embodiment, the position of the local maximum point is set so that θ1> θ2 is always satisfied. At least compared with the case of θ1 = θ2, the acceleration section can be switched to the discharge section with a small speed change. Therefore, the pressure fluctuation accompanying the speed change is suppressed at the ink discharge start time in the discharge section.

  When the adjustment is made to the stop time Tw, the position of the maximum point is preferably set to the starting point side of the acceleration section from the case of no adjustment from the viewpoint of suppressing the ink pressure fluctuation. Furthermore, regarding the profile on the deceleration side, setting the angle to θ2 ′ (<θ2) is also effective in suppressing pressure fluctuation.

  FIG. 9 shows a modification (Modification 1). In this modification, the position of the maximum point is set so that θ1 <θ2 is always satisfied. At least the area where the speed of the carriage 2 is equal to or higher than the predetermined speed Vt is closer to the discharge section than when θ1 = θ2. This area has a shorter encoder output period than the remaining area. The ink in the nozzle 10 is vibrated at a shorter cycle. The shorter the vibration period, the higher the effect of eliminating ink thickening, and the ink thickening is reliably eliminated at the start of ink ejection in the ejection section. Note that the relationship between FIG. 9A and FIG. 9B corresponds to the relationship between FIG. 8A and FIG. 8B. FIG. 9B shows the influence of printing duty and humidity.

  In the second embodiment, the ink is vibrated at a short cycle and the effect of eliminating the thickening is high, at least as compared with the case where the peak speed Vp is not provided. In particular, in the embodiment of FIG. 8, there is a relationship of α (+)> α (−) and θ1> θ2, and immediately before switching to the ejection section, the ink oscillation period is short, but the drive period in the ejection section is the same. A close state continues. When the section is switched, the speed change to the predetermined speed Vt is small. That is, the section is smoothly switched and the image quality at the start of printing is not disturbed. In the form of FIG. 9, there is a relationship of α (+) <α (−) and θ1 <θ2, and the effect of eliminating ink thickening is enhanced immediately before the section is switched. This form is effective when an ink that is easy to dry (for example, pigment-based ink) is used.

  Next, modified examples in which various changes are made to the first and second embodiments will be described.

  In the second embodiment, the peak speed Vp in the scan printing is set to a higher speed as the stop time Tw is longer without changing the length of the acceleration section and the deceleration section for each scan printing. However, the present invention is not limited to this. . In the second embodiment, as the stop time Tw is longer, in addition to setting the peak speed Vp in scan printing to a higher speed, as in the first embodiment, the carriage is decelerated and stopped in scan printing. The position may be set to a position outside the scanning direction.

  In the second embodiment, the peak speed Vp is preferably set such that the driving frequency corresponding to the peak speed Vp is equal to or higher than the resonance frequency of the ink flow path. When the drive frequency is the resonance frequency (including frequencies before and after this), the vibration efficiency of the ink is higher. Here, the predetermined speed Vt has a driving frequency corresponding to the predetermined speed Vt lower than the resonance frequency of the flow path. When the moving speed of the carriage 2 corresponding to the resonance frequency is a resonance speed Vs, Vs> Vt. At this time, there is a relationship of Vp> Vs, but it is not limited to this. For example, if the stop time Tw is longer than the predetermined time T0, Vp> Vs. In the case of Tw ≦ T0, Vs ≧ Vp> Vt may be satisfied. When the stop time Tw is short, it is not necessary to vibrate ink more than necessary.

  In the second embodiment, the magnitude of acceleration of the carriage 2 when the carriage 2 is accelerated to the peak speed Vp may be the same as the magnitude of acceleration of the carriage 2 when the carriage 2 is decelerated to the predetermined speed Vt. .

  Furthermore, the peak speed Vp may be set to a speed higher than the predetermined speed Vt and lower than the resonance speed Vs regardless of the stop time Tw.

  In the second embodiment, the carriage 2 is accelerated to the peak speed Vp faster than the predetermined speed Vt and decelerated to the predetermined speed Vt regardless of the stop time Tw of the carriage 2. However, the present invention is not limited to this. . For example, only when the stop time Tw is longer than a predetermined time, the carriage 2 is accelerated to the peak speed Vp faster than the predetermined speed Vt and then decelerated to the predetermined speed Vt. When the stop time Tw is equal to or shorter than the predetermined time, the carriage 2 may be monotonously accelerated to the predetermined speed Vt without having the peak speed Vp. In this case, it is possible to prevent the ink in the nozzle 10 from vibrating more than necessary when the stop time Tw is shorter than in the second embodiment.

  In the second embodiment, the peak speed Vp is set to a higher speed as the stop time Tw is longer. However, the present invention is not limited to this. For example, the peak speed Vp may be a constant speed regardless of the stop time Tw, and the position of the carriage 2 when the carriage 2 reaches the peak speed Vp in the scanning direction may be varied according to the stop time Tw. . That is, the peak speed Vp is set to a constant speed regardless of the stop time Tw, and the acceleration when the carriage 2 is accelerated to the peak speed Vp and the carriage 2 is decelerated to the predetermined speed Vt according to the stop time Tw. The acceleration may be varied. When the stop time Tw is long, the ink viscosity increases further. On the other hand, the high frequency vibration time of the ink may be lengthened. That is, the maximum point of speed is set closer to the starting point of the acceleration section as the stop time Tw is longer.

  In the second embodiment, the carriage 2 is accelerated to the peak speed Vp and then immediately decelerated. However, the present invention is not limited to this. For example, after the carriage 2 is accelerated to the peak speed Vp, the speed of the carriage 2 may be maintained at the peak speed Vp and then decelerated to the predetermined speed Vt. At this time, regardless of the length of the stop time Tw, the peak speed Vp may be maintained for a predetermined time, or the longer the stop time Tw, the longer the time for maintaining the peak speed Vp. Furthermore, the state where the peak speed Vp is maintained may be limited to the case where the stop time Tw exceeds a predetermined threshold.

  In the first and second embodiments, when the carriage 2 is accelerated, the ink jet head 3 is driven to vibrate the ink in the nozzle 10 and the carriage 2 is decelerated so that the ink is not ejected from the nozzle 10. The inkjet head 3 is not driven, but is not limited to this. In the first and second embodiments, even when the carriage 2 is decelerated, the ink in the nozzle 10 may be vibrated by driving the inkjet head 3 so that the ink is not ejected from the nozzle 10.

  In the first embodiment, the longer the stop time Tw from the completion of a certain scan printing to the start of the next scan printing, the longer the length of the deceleration section in a certain scan printing. However, the number of times the ink in the nozzle 10 is vibrated increases, and the thickening of the ink in the nozzle 10 can be effectively eliminated.

  In the second embodiment, when the ink in the nozzle 10 is vibrated even when the carriage 2 is decelerated, as shown in FIGS. 10A and 10B, the carriage 2 is decelerated in the decelerating section. Alternatively, the carriage 2 may be accelerated to a speed faster than the predetermined speed Vt, and then the carriage 2 may be decelerated and stopped (Modification 2). In this case, in the deceleration zone, the drive frequency of the inkjet head 3 is temporarily increased, and the period for vibrating the ink in the nozzle 10 can be shortened. In FIGS. 10A and 10B, the peak speed of the carriage 2 in the deceleration section is the same speed as the peak speed Vp (Vp1, Vp2) of the carriage 2 in the acceleration section. The peak speed of the carriage 2 may be different from the peak speed Vp of the carriage 2 in the acceleration section.

  In the first embodiment, as the humidity detected by the humidity sensor 19 is lower, the carriage stop position is set to the outside in the scanning direction in the deceleration section, so that the length of the deceleration section in the certain scan printing (next) The length of the acceleration section in the scan printing is increased, but the present invention is not limited to this. The stop position in the deceleration zone may not change depending on the humidity around the printer 1. Similarly, in the second embodiment, the peak speed Vp of the carriage 2, the acceleration when accelerating to the peak speed Vp, and the acceleration when decelerating from the peak speed Vp to the predetermined speed Vt depend on the humidity around the printer 1. May not change. In these cases, the humidity sensor 19 may not be provided in the printer 1.

  In the first embodiment, as the stop time Tw is longer, the stop position in the deceleration section in the certain scan printing is set to a position outside the scanning direction, whereby the length of the deceleration section in the certain scan printing ( Although the length of the acceleration section in the next scan printing is increased, this is not restrictive. For example, regardless of the stop time Tw, the stop position in the deceleration section in the certain scan printing is set to the same position, and the longer the stop time Tw, the larger the carriage 2 on the opposite side to the discharge section K0 in the next scan printing. The carriage 2 may be moved toward the ejection section K0 while accelerating after being moved (the stop position on one side in the next scan printing is set to the outside position). Even in this case, the longer the stop time Tw, the longer the length of the acceleration section in the next scan printing.

  That is, for the carriage movement for moving the carriage from the stop position on one side of the carriage movement section to the stop position on the other side, the control device sandwiches the discharge section that discharges the liquid from the nozzle and moves the carriage from the stop position on one side. The position of the acceleration section that accelerates and the position of the deceleration section that decelerates the carriage to the stop position on the other side is set, and the count number from the encoder is set to at least one of the acceleration section and the deceleration section. When the position of the acceleration section and the deceleration section is set by driving the inkjet head every time it is increased to vibrate so as not to discharge the liquid in the nozzle, the next carriage movement is performed after the completion of a certain carriage movement. Calculate the carriage stop time until it starts, and the longer the stop time, One side of the stop position in the movement, it is characterized in that setting the position outside the scanning direction.

  In the first and second embodiments, the carriage 2 is moved at a constant speed at a predetermined speed Vt in the discharge section K0. However, the carriage 2 is not limited to be moved at a constant speed in the discharge section K0. For example, the carriage 2 may be accelerated in a part of the acceleration section and the discharge section K0. Alternatively, for example, the carriage 2 may be decelerated in a part of the deceleration section and the discharge section K0.

  In the second embodiment, the carriage 2 is accelerated to the peak speed Vp faster than the predetermined speed Vt in the acceleration section and then decelerated to the predetermined speed Vt. Further, according to the stop time Tw, the carriage 2 in the acceleration section is accelerated. Although the method of acceleration is different, this is not a limitation. Regardless of the stop time, the carriage 2 may be uniformly accelerated in the acceleration section to the same peak speed Vp and then decelerated to the predetermined speed Vt. Even in this case, the driving frequency of the ink jet head 3 in the acceleration section can be increased as compared with the case where the carriage 2 is accelerated to the predetermined speed Vt without accelerating to the speed higher than the predetermined speed Vt in the acceleration section. . Thereby, the period which vibrates the ink in the nozzle 10 in an acceleration area can be shortened.

  In the above example, each time the encoder sensor 22 counts the slits, the inkjet head 3 is driven to eject ink from the plurality of nozzles 10 and to vibrate ink in the plurality of nozzles 10. However, it is not limited to this. The driving of the inkjet head 3 for discharging ink from the plurality of nozzles 10 may be performed by a signal different from the signal from the encoder sensor 22.

  In the first embodiment, when setting a stop position in a certain deceleration period of scan printing by the stop time Tw of the carriage 2, a threshold value Tws for the stop time Tw may be provided. In the case of Tw <Tws, the stop position is not newly set and is set to a predetermined position. If Tw ≧ Tws, a stop position corresponding to the length of the stop time Tw is set. This simplifies the process of setting the stop position and does not cause unnecessary delay in starting the printing process. Note that Tws may be set to a time when image quality deterioration can be identified when the stop time Tw is longer than this.

  In the first embodiment, when the stop time Tw is set to be long, the deceleration section length in one scan printing is long, and the acceleration section length in the next scan printing is also long. At the same time, α (-) and α (+) were lowered. However, from the viewpoint of overall high throughput, the deceleration and acceleration may be constant regardless of the length of the stop time Tw. In this case, in a deceleration section of a certain scan printing, the carriage 2 is moved to the stop position at the speed Vt, leaving a section necessary for stopping at the stop position set from the predetermined speed Vt at a constant deceleration rate α (−). Move towards. On the other hand, in the acceleration section of the next scan printing, the carriage 2 moves toward the discharge section at the speed Vt, leaving the section necessary for acceleration from the stop position set at a constant acceleration α (+) to the speed Vt. Moving.

  In the above description, an example in which the present invention is applied to a printer that prints on recording paper by ejecting ink from nozzles has been described. However, the present invention is not limited thereto. The present invention can also be applied to a liquid ejection apparatus other than a printer that ejects liquid other than ink from nozzles.

DESCRIPTION OF SYMBOLS 1 Printer 2 Carriage 3 Inkjet head 10 Nozzle 13, 14 Pulley 15 Belt 16 Carriage motor 17 Encoder 19 Humidity sensor 50 Control apparatus

Claims (13)

A liquid discharge head having a nozzle;
A carriage on which the liquid discharge head is mounted;
A carriage movement mechanism for moving the carriage in a carriage movement section defined by stop positions on both sides with respect to the scanning direction;
An encoder for detecting the position of the carriage in the scanning direction;
A control device for controlling the liquid ejection head and the carriage moving mechanism,
The controller is
With respect to carriage movement for moving the carriage from a stop position on one side of the carriage movement section to a stop position on the other side, the carriage is moved from the stop position on the one side with a discharge section for discharging liquid from the nozzle interposed therebetween. Set the acceleration section to accelerate and the position of the deceleration section to decelerate the carriage to the stop position on the other side,
By driving the liquid discharge head every time the encoder count number increases in the acceleration section, the liquid is vibrated so as not to discharge the liquid in the nozzle,
When setting the position of the acceleration section and the deceleration section,
The stop time of the carriage from the completion of a certain carriage movement to the start of the next carriage movement is calculated, and the longer the stop time, the more the stop position on the one side in the next carriage movement, A liquid ejection apparatus, wherein the liquid ejection apparatus is set at a position outside the scanning direction. The controller is
2. The liquid ejecting apparatus according to claim 1, wherein the liquid ejecting head is driven so as not to eject the liquid in the nozzle in the deceleration section by driving the liquid ejecting head each time the count number of the encoder increases. . A humidity sensor for detecting the humidity around the device;
The controller is
When setting the position of the acceleration section and the deceleration section,
The stop position on the one side in the next carriage movement is set to an outer position in the scanning direction as the signal from the humidity sensor indicates that the humidity is lower. The liquid ejection device according to 1 or 2. The controller is
2. The vehicle according to claim 1, wherein the carriage is accelerated in the acceleration section to a speed faster than the speed in the discharge section and then decelerated to the speed in the discharge section in accordance with the stop time. 4. The liquid ejection device according to any one of 3. A liquid discharge head having a nozzle;
A carriage on which the liquid discharge head is mounted;
A carriage moving mechanism for moving the carriage in the scanning direction;
An encoder for detecting the position of the carriage in the scanning direction;
A control device for controlling the liquid ejection head and the carriage moving mechanism,
The controller is
In one carriage movement for moving the carriage in the scanning direction, the carriage is accelerated in an acceleration section located upstream of a discharge section for discharging liquid from the nozzle in the carriage movement direction, and the discharge section Decelerate the carriage in a deceleration section located downstream of the
By driving the liquid discharge head every time the encoder count number increases in the acceleration section, the liquid is vibrated so as not to discharge the liquid in the nozzle,
According to the stop time of the carriage from the completion of a certain carriage movement to the start of the next carriage movement, in the next carriage movement, in the acceleration section, the carriage is moved from the speed in the discharge section. A liquid ejection apparatus characterized by accelerating to a faster speed and then decelerating to a speed in the ejection section. The controller is
6. The liquid ejecting apparatus according to claim 4, wherein the longer the stop time is, the higher the peak value of the speed of the carriage in the acceleration section is set in the next carriage movement. The controller is
In the acceleration section, the magnitude of acceleration of the carriage when accelerating the carriage to a speed faster than the speed in the discharge section, and then the carriage when decelerating the carriage to the speed in the discharge section. The liquid ejection apparatus according to claim 4, wherein the liquid ejection apparatus is larger than the magnitude of acceleration. The controller is
In the acceleration section, the magnitude of acceleration of the carriage when accelerating the carriage to a speed faster than the speed in the discharge section, and then the carriage when decelerating the carriage to the speed in the discharge section. The liquid ejection apparatus according to claim 4, wherein the liquid ejection apparatus is smaller than the magnitude of acceleration. When the drive frequency of the liquid discharge head is equal to the resonance frequency of the liquid flow path in the liquid discharge head, the resonance speed that is the speed of the carriage is faster than the speed of the carriage in the discharge section,
The controller is
The liquid ejecting apparatus according to claim 4, wherein in the acceleration section, the carriage is accelerated to a speed equal to or higher than the resonance speed and then decelerated to a speed in the ejection section. The controller is
When the stop time is longer than a predetermined time, in the next carriage movement, the carriage is accelerated in the acceleration section to a speed faster than the speed in the discharge section according to the stop time. Decelerate to the speed in the discharge section,
When the stop time is equal to or shorter than the predetermined time, in the next carriage movement, in the acceleration section, the speed in the discharge section is not accelerated to a speed higher than the speed in the discharge section. The liquid ejecting apparatus according to claim 4, wherein the liquid ejecting apparatus is accelerated to a predetermined speed. The controller is
11. The carriage according to claim 4, wherein in the deceleration section, the carriage is accelerated to a speed faster than the speed in the discharge section and then decelerated, and the liquid is vibrated without discharging the liquid in the nozzle. The liquid ejection device according to any one of the above. A humidity sensor for detecting the humidity around the device;
The controller is
The peak value of the speed in the acceleration section of the carriage is set to be higher as the signal from the humidity sensor indicates that the humidity is lower. The liquid discharge apparatus as described. A liquid discharge head having a nozzle;
A carriage on which the liquid discharge head is mounted;
A carriage moving mechanism for moving the carriage in the scanning direction;
An encoder for detecting the position of the carriage in the scanning direction;
A control device for controlling the liquid ejection head and the carriage moving mechanism,
The controller is
In one carriage movement for moving the carriage in the scanning direction, the carriage is accelerated in an acceleration section located upstream of a discharge section for discharging liquid from the nozzle in the carriage movement direction, and the discharge section Decelerate the carriage in a deceleration section located downstream of the
By driving the liquid discharge head every time the encoder count number increases in the acceleration section, the liquid is vibrated so as not to discharge the liquid in the nozzle,
In the acceleration section, the carriage is accelerated to a speed faster than the speed in the discharge section, and then decelerated to the speed in the discharge section.

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