JP2015217592A - Ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet printer that discharges ink from an ink jet head periodically by providing an area to which thickened ink is discharged outside a recording area.SOLUTION: A roller is used as a reception part so that discharged ink is not layered. A tank which reserves a cleaning liquid is provided below the roller to dip a lower part of the roller, which can be cleaned with the cleaning liquid. A blade is applied and ink is forced to flow in a waste liquid tank so that the ink does not stick on the roller and flow into the tank reserving the cleaning liquid. The ink is discharged to a clean roller surface to be prevented from being layered on the roller.

Description

  The present invention relates to an inkjet printer that records an image by ejecting ink.

  2. Related Art Ink jet printers that record images by ejecting ink from an ink jet head onto a recording medium such as paper or resin film are known. Inkjet printers are required to improve performance such as high image quality, durability, and reliability. If foreign matter adheres to the nozzles of the ink-jet head, ejection failure such as ink not being ejected may occur due to the influence. Therefore, in a general ink jet printer, ink is periodically ejected from the nozzles of the ink jet head to prevent ejection failure. Moreover, the problem that the ink thickens in the nozzles by discharging the ink regularly is solved.

Ink is regularly ejected outside the recording area such as the edge of the recording medium, and an area for ejecting ink is provided outside the platen, and ink is ejected regularly there.
For example, JP 2012-56207 A is given as a conventional technique. In this technique, an area for ejecting ink is provided outside the platen, and ink is ejected there.

JP 2012-56207 A

  In the prior art, ink is ejected to a cylinder, and the ink is made to flow along a slope of the cylinder to prevent the ink volume. However, in the conventional technique, since there is no means for cleaning the cylinder, there is a problem that the ink does not flow down the inclined surface of the cylinder when the ink after thickening which is easy to dry adheres. Further, since the cylinders are arranged so that the axial directions of the cylinders coincide with the nozzle rows of the inkjet head, ink is ejected to the apex portion of the arranged cylinders. For this reason, since the ink does not land on the slope, the thickened ink may not flow down immediately, causing a problem of adhering as it is.

  With respect to such problems, the present invention can suitably perform spit, and can prevent contamination of the nozzle surface due to ink accumulation in the spit area. Thereby, a high-quality image can be recorded and a highly reliable ink jet printer is provided.

  An ink jet printer according to the present invention includes an ink jet head having a plurality of nozzles for ejecting ink onto a recording medium, a platen that supports the recording medium, and the ink jet head mounted on the recording medium supported by the platen. A carriage that reciprocally scans, a conveyance unit that conveys the recording medium, and a detection unit that detects the position of the carriage, and ejects the ink from the inkjet head to a desired position on the recording medium. In the ink jet printer for recording an image, a spit unit disposed outside the carriage in the carriage movement direction of the platen and receiving the ink ejected from the ink jet head, and mounted on the carriage, the cleaning liquid is applied to the spit unit. Dropping means for dropping; The spit unit is rotatably supported and includes a roller for receiving the ink discharged from the inkjet head, and a blade for wiping the surface of the roller. Cleaning is performed by wiping with a blade and bringing it into contact with the cleaning liquid.

  According to the present invention, spit can be suitably performed and contamination of the nozzle surface due to spit can be prevented. Thereby, a high-quality image can be recorded, and a highly reliable ink jet printer can be provided.

FIG. 1 is a schematic view of an ink jet printer. FIG. 2 is a diagram illustrating an example of ejection in which ink is performed on a roller. FIG. 3 is a diagram for explaining an example of filling with the cleaning liquid. FIG. 4 is a diagram illustrating an example of a roller. FIG. 5 is a block diagram of the ink jet printer. FIG. 6 is a flowchart for explaining the operation.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view of an ink jet printer. As shown in FIG. 1, the inkjet printer 1 according to the present embodiment arranges the recording medium 18 horizontally, conveys the recording medium 18 from the back of the drawing in FIG. 1, ejects ink from the inkjet head 3, and records the recording medium 18. Images, characters, etc. corresponding to the recording data are recorded on the surface of the. The recording medium 18 is paper, a resin film, or the like. This paper conveyance direction is called the sub-scanning direction.

  The ink jet printer 1 includes a transport unit that transports the recording medium 18. In addition, the inkjet head 3 and the cleaning liquid dropping means 4 are mounted, and the carriage 2 that reciprocates in the direction intersecting the conveyance direction of the recording medium 18, here the orthogonal direction, and the wipe unit 10 that wipes the inkjet head 3. A capping unit 8 that caps the inkjet head 3, and a spit unit 11 that receives ink discharged from the inkjet head 3. The moving direction of the reciprocating scanning is called a main scanning direction. The ink jet printer 1 includes control means for controlling the entire apparatus including reception of recording data and control of recording operation.

  The conveying means includes a plurality of conveying roller pairs 16 driven by a motor on a substantially flat platen 17 extended in the depth direction of the paper surface of FIG. The transport roller pair 16 includes a grid roller having a parallel rotation axis and a pinch roller that is energized by the grid roller. The recording medium 18 is conveyed while being sandwiched between the grid roller and the pinch roller. As the grid roller rotates, the recording medium 18 is conveyed from the depth direction to the near side.

  The carriage 2 is provided so as to be movable along a carriage rail 13 extending in a direction perpendicular to the conveyance direction of the recording medium 18 above the conveyance means, the wipe unit 10, the spit unit 11, and the capping unit 8. Yes. In addition, a motor 15 that reciprocates the carriage 2 on the carriage rail 13 so as to be capable of position control and speed control is provided. The motor 15 is connected to the endless belt 12 to which the carriage 2 is fixed, and drives the endless belt 12. A linear scale 14 is provided in parallel with the carriage rail 13. A linear sensor for detecting the scale of the linear scale 14 is provided in the carriage 2. The position of the carriage 2 can be detected, and the positions of the plurality of ink jet heads 3 and the dropping means 4 fixed to the carriage 2 can be calculated accordingly, and the control means can acquire them.

In the present embodiment, four inkjet heads 3 are provided corresponding to four color inks of black, yellow, magenta, and cyan for performing color recording.
Although details of the inkjet head 3 are not shown, a plurality of nozzles that eject ink are arranged in a row, and the supplied ink is ejected by an ejection mechanism such as a piezoelectric element. The ink jet printer 1 causes the spit unit 11 to eject ink from the nozzles outside the image forming range, and ejects thickened ink or ejects to adjust the meniscus.

  Position control and speed control of the motor 15 that drives the carriage 2 are performed in accordance with control signals from the control means. During the recording operation, the motor 15 is controlled so that the inkjet head 3 reciprocates over the recording medium 18 at a predetermined speed. Further, the motor 15 moves the inkjet head 3 to a predetermined wiping position of the wipe unit 10 during the cleaning operation. Further, when capping, it is moved onto the capping unit 8, and when spitting, it is moved onto the spit unit 11.

  The wipe unit 10 wipes and cleans the nozzle surface of the inkjet head 3 by moving the wipe blade relative to the nozzle surface of the inkjet head 3 with the inkjet head 3 moved above the wipe unit 10. To do. The capping unit 8 discharges foreign matter and thickened ink from the inkjet head 3 by sucking ink from the inkjet head 3 from the nozzles to the outside. Also, the ink is prevented from drying by capping when not in use. The schematic configuration of the capping unit 8 includes a cap, lifting means for moving the cap up and down, a suction unit for sucking the inside of the cap, and a waste ink bottle 9 for storing the sucked ink. A cap is provided for each inkjet head 3. The lifting / lowering means performs a vertical movement for selectively switching the position of the cap in the vertical direction, and includes, for example, appropriate mechanical / electromagnetic / fluid lifting / lowering means.

  The carriage 2 includes gripping means 5 for gripping a cleaning roller 6 that cleans the cap. The cleaning roller 6 that is not in use is placed on a table 7 having a recess in which the rotation shaft of the cleaning roller 6 can be placed.

  FIG. 2 is a diagram illustrating an example of ejection in which ink is performed on a roller. The carriage 2 is provided with four inkjet heads 3. The head is compatible with black, cyan, magenta, and yellow ink colors. Moreover, the dripping means 4 which discharges cleaning liquid is provided. The spit unit 11 is supported so that the spit roller 24 can rotate. The spit roller 24 rotates in the direction of the arrow by driving the rotary shaft 33 with a motor. A waste liquid tray 19 for storing waste ink is provided outside the cleaning liquid tray 20 for storing the cleaning liquid. The spit roller 24 is disposed inside the upper opening of the cleaning liquid tray 20.

  The carriage 2 is moved so that the nozzle row of the inkjet head 3 is at a position facing the spit roller 24, and ink 28 is ejected from the nozzles. For example, ink is ejected when the thickened ink is discharged, when foreign matter is clogged, or when a meniscus is prepared. The ink 29 attached to the spit roller 24 moves in the direction of the ink blade 25 as the spit roller 24 rotates, and is transferred to the waste liquid tray 27 by the ink blade 25 and stored in the waste liquid tray 19.

  The cleaning liquid tray 20 contains a cleaning liquid. The cleaning liquid tray 20 is provided with a discharge hole 21 at the position of the maximum draft 31 of the cleaning liquid. When the discharge hole 21 is exceeded, it is discharged to the waste liquid tray 19. The maximum draft 31 is a limit amount of position for the device to operate normally. The lower part of the spit roller 24 is immersed in the cleaning liquid in the cleaning liquid tray 20, and the surface is cleaned by rotating. The cleaning liquid 30 adhering to the surface of the spit roller 24 is scraped off by the cleaning liquid blade 23 and stored in the cleaning liquid tray 19. When the ink discharged toward the spit roller 24 flows in the direction of the cleaning liquid blade 23, the ink is stored in the waste liquid tray 19 through the waste liquid tank 26. The inclined portion 22 receives the cleaning liquid discharged by the dripping means 4 and guides the cleaning liquid into the cleaning liquid tray 19.

  Further, when waste ink, cleaning liquid or the like stored in the waste liquid tray 19 exceeds the draft 32, it is necessary to discard the waste liquid, and a notification is given. This is the limit for safe use of the spit unit.

  The ink blade 25 is a sheet made of a resin such as rubber or silicon, and the tip abuts on the surface of the spit roller 24 to wipe off the liquid adhering to the surface. The tip is disposed parallel to the rotation shaft 33 and is in close contact with the surface of the spit roller 24. Waste ink or the like is guided to the waste liquid tray 19 so as not to enter the cleaning liquid tray 20. That is, the ink blade 25 scrapes off the liquid adhering to the surface so that the cleaning liquid in the cleaning liquid tray is not soiled.

  The cleaning liquid blade 23 is a sheet made of a resin such as rubber or silicon, and the tip abuts on the surface of the spit roller 24 to wipe off the liquid adhering to the surface. The tip is disposed parallel to the rotation shaft 33 and is in close contact with the surface of the spit roller 24. The cleaning liquid or the like is guided to the cleaning liquid tray 20. That is, the liquid adhering to the surface is scraped by the cleaning liquid blade 23 to keep the surface of the spit roller 24 clean.

  Although ink is ejected to the spit roller 24, ink can be prevented from accumulating on the surface. If accumulated, the lump of ink deposited on the nozzle surface comes into contact, causing problems such as ejection failure.

  FIG. 3 is a diagram for explaining an example of filling with the cleaning liquid. The carriage 2 is moved to a position where the nozzle of the dropping unit 4 faces the inclined portion 22, and the cleaning liquid 34 is discharged from the dropping unit 4. The cleaning liquid tray 20 is provided with a liquid amount detecting means 35 for detecting the liquid amount of the cleaning liquid. The cleaning liquid is replenished from the dripping means 4 based on the liquid amount detected by the liquid amount detecting means 35. Replenish so that the cleaning liquid is maintained at a predetermined amount. For example, when the state of the draft 36 where the spit roller 24 is not immersed is detected, the dripping means 4 replenishes the cleaning liquid up to the maximum draft 31 amount.

  FIG. 4 is a diagram illustrating an example of a spit roller. The spit roller 24 is a roller made of cylindrical resin or metal. A rotation shaft 33 is provided at the center of the cylinder along the longitudinal direction. The rotating shaft 33 is rotatably supported by the bearing 42. The rotating shaft 33 is connected to a wheel train 37. The train wheel 37 is connected to a motor 38 and driven. The spit roller 24 is driven in conjunction with the train wheel 37 and rotates. With respect to the positional relationship between the inkjet head 3 and the nozzle row 39 and the spit roller 24 indicated by dotted lines, the axial direction 40 of the rotary shaft 33 and the row direction 41 of the nozzle row 39 are inclined by θ. Due to this inclination, the distance between the nozzle of the inkjet head 3 and the spit roller 24 varies depending on the position of the nozzle. The ink blade 25 is also arranged so that its tip is parallel to the rotation axis of the spit roller 24. Therefore, the ink adhering to the spit roller 24 can be gradually scraped from the end instead of being scraped simultaneously. Therefore, it is possible to prevent the path for guiding the waste ink to the waste liquid tray 19 from being clogged with the waste ink and overflowing. In addition, since the ink that has been ejected and adhered is gradually scratched, the blade is less likely to lift, so that the cleaning liquid is less likely to become dirty. The cleaning liquid blade 23 is also arranged so that the tip thereof is parallel to the rotation axis of the spit roller 24. Therefore, the cleaning liquid adhering to the spit roller 24 can be scraped gradually from the end instead of being scraped at the same time, so that the blade is difficult to float and can be suitably wiped off.

  FIG. 5 is a block diagram of the ink jet printer. The control unit 50 is a control unit including a CPU that executes processing operations such as calculation, control, determination, and setting. The control means 50 operates according to a control program stored in the ROM 48. The RAM 49 is used as a temporary storage area for data and a work area for processing by the control means 50. The carriage movement motor drive circuit 43 operates under the control of the control means 50 and drives the motor 15 that moves the carriage 2.

  The carriage position detection sensor 44 is a linear sensor that detects the scale of the linear scale 14. It is mounted on the carriage 2. Based on this sensor output, the position of the carriage 2 is calculated and acquired. The head drive circuit 45 is controlled by the control means 50. The inkjet head 3 is operated via the head drive circuit 45. When a plurality of inkjet heads 3 are mounted, the control unit 50 and the head driving circuit 45 can drive each inkjet head 3 individually. The head drive circuit 45 generates ink ejection timing or non-ejection timing for each inkjet head 3 based on information input from the control means 50 and drives the inkjet head 3. When ink ejection is performed, an ON waveform is generated. When ink ejection is not performed, an OFF waveform is generated and transferred to each inkjet head 3. The ejection timing is calculated according to the position of the carriage 2.

The roller drive circuit 46 operates under the control of the control means 50 and drives a motor that rotates the spit roller 24.
The cleaning droplet lower motor drive circuit 47 operates under the control of the control means 50. The dropping means 4 drives a motor for dropping the cleaning liquid. The dropping means 4 is provided with a tube pump and drives a motor that drives the tube pump. When the motor is rotated forward, the cleaning liquid is discharged, and when stopped, it stops.

  The liquid amount detection unit 35 operates under the control of the control unit 50. The amount of the cleaning liquid stored in the cleaning liquid tray 20 is detected. As for the amount to be detected, the minimum amount of cleaning liquid to be stored and a sufficient amount to be stored are detected. For example, the amount can be detected by floating a float and detecting its position with a sensor. The control means 50 can acquire information on the liquid amount. It is necessary to wet the surface of the spit roller 24 with the cleaning liquid and rinse the dirt. Therefore, it is preferable that about half of the lower end side of the spit roller 24 is immersed in the cleaning liquid. Since the cleaning liquid tray 20 has the discharge hole 21, the position of the lower end of the discharge hole 21 is the maximum amount that can be accommodated. For example, a sufficient amount to be stored is an amount equal to or less than the maximum amount, and is an amount that the spit roller 24 is immersed in the cleaning liquid by about one third. If the center of rotation is immersed, there is a risk that a problem will occur in the rotation mechanism.

FIG. 6 is a flowchart for explaining the operation. Each function of the inkjet printer 1 is controlled and operated by the control of the control means 50.
First, in step S1, the carriage 2 is moved. The position to be moved is a position where the nozzle row of the inkjet head 3 faces the spit roller 24. Next, in step S2, the spit roller 24 is rotated. Next, in step S3, ink is ejected while rotating. The plurality of inkjet heads 3 are sequentially repeated until all the inkjet heads 3 for spitting are completed (step S4).

  When all the operations are completed, in step S5, the carriage 2 is moved to a position where the dropping means 4 faces the spit roller 24. Next, in step S6, the cleaning liquid is dropped onto the spit roller 24. Waste ink paths such as the spit roller 24, the ink blade 25, and the waste liquid tank 27 are washed away with the cleaning liquid.

  Next, in step S7, it is detected by the liquid amount detecting means 35 whether or not the cleaning liquid is in a predetermined amount, and when there is no predetermined amount and the cleaning liquid is filled, the process proceeds to step S8. Stop and end the process.

  In step S <b> 8, the carriage 2 is moved to a position where the dropping unit 4 faces the inclined portion 22. In step S9, the cleaning liquid is supplied until a predetermined amount of cleaning liquid is accumulated in the cleaning liquid tray 20. After a predetermined amount of cleaning liquid has accumulated in the cleaning liquid tray 20, the driving of the spit roller 24 is stopped and the processing is completed.

  The present invention can be used for a printer having a cap for sealing an inkjet head.

DESCRIPTION OF SYMBOLS 1 Inkjet printer 2 Carriage 3 Inkjet head 4 Dripping means 5 Grip means 6 Cleaning roller 7 Unit 8 Capping unit 10 Wipe unit 11 Spit unit 12 Endless belt 13 Carriage rail 14 Linear scale 15 Motor 16 Carrying roller pair 17 Platen 18 Recording medium 19 Waste liquid Tray 20 Cleaning liquid tray 23 Cleaning liquid blade 24 Spit roller 25 Ink blade

Claims (6)

An inkjet head comprising a plurality of nozzles for ejecting ink onto a recording medium;
A platen that supports the recording medium;
A carriage mounted with the inkjet head and reciprocally scanning the recording medium supported by the platen;
Conveying means for conveying the recording medium;
Detecting means for detecting the position of the carriage;
In an inkjet printer that records an image by ejecting the ink from the inkjet head to a desired position on the recording medium,
A spit unit disposed outside the platen in the moving direction of the carriage and receiving the ink ejected from the inkjet head;
Dropping means mounted on the carriage and dropping a cleaning liquid onto the spit unit;
Have
The spit unit is rotatably supported and receives the ink ejected from the inkjet head;
A blade for wiping the surface of the roller,
The inkjet printer is cleaned by wiping the roller with the blade and bringing the dirt into contact with the cleaning liquid. The spit unit is
A waste ink tray for storing the ink ejected from the inkjet head;
A cleaning liquid tray that contains the cleaning liquid and removes dirt on the roller by immersing a part of the roller;
A waste ink path for guiding the ink collected by the ink blade to the waste ink tray;
A cleaning liquid blade that wipes the cleaning liquid adhering to the roller and returns the cleaning liquid to the cleaning liquid tray;
A motor for driving the roller;
The roller is driven by the motor, the ink ejected from the inkjet head, the ink adhering to the roller is wiped off by the ink blade, the ink is accommodated in the waste ink tray, and adhered to the roller The inkjet printer according to claim 1, wherein the cleaning liquid is wiped by the cleaning liquid blade and stored in the cleaning liquid tray.   The inkjet printer according to claim 1, wherein a row direction of the nozzles of the inkjet head intersects with a rotation axis direction of the roller. The spit uni has a sensor for detecting the amount of the cleaning liquid stored in the cleaning liquid tray,
4. The cleaning liquid tray is filled with the cleaning liquid by the dropping unit when the amount of the cleaning liquid in the cleaning liquid tray is equal to or less than a predetermined amount. Inkjet printer.   The cleaning liquid is dropped onto the roller from the dropping unit, the cleaning liquid adhering to the roller is wiped with the ink blade, the roller is cleaned, and the wiped cleaning liquid is stored in the waste ink tray. The inkjet printer according to claim 2, wherein the inkjet printer is a printer.   The inkjet printer according to claim 2, wherein the cleaning liquid tray has a discharge port for discharging the cleaning liquid to the waste ink tray.

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