JP2006263972A - Inkjet recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recovering means which discharges air bubbles, foreign substances, etc. in a nozzle, and also, on the discharging port surface of which an ink residue is not generated in the recovering means which recovers a non-discharged nozzle of a printing head, and also, to provide an inkjet recording device equipped with the recovering means. <P>SOLUTION: The recovery of the non-discharged nozzle is made possible by discharging an ink from the ink discharging port of the printing head H by pressurizing the fed ink. After the discharge of the ink, the absorbing section of an ink absorber 11 is brought into contact with the discharging port surface of the printing head, and the discharging port surface is rubbed by the absorbing section which has been brought into contact with the discharging port surface. Thus, the ink residue is removed, and the injection deflection of the ink by the ink adhered to the edge of the nozzle is reduced. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ink jet recording apparatus. Specifically, there is provided means for discharging ink from an ejection port of a print head (hereinafter also referred to as an inkjet head) of an inkjet recording apparatus, absorbing the ink with an absorber, and rubbing the ejection port surface with the absorber. The present invention relates to an inkjet recording apparatus.

  In an ink jet recording apparatus, if the ink is not used for a long period of time, the viscosity of the ink increases due to the evaporation of water from the ink outlet of the ink jet head, resulting in clogging. This causes troubles such as the occurrence of bubbles and the occurrence of bubbles from the nozzles, resulting in a pressure loss in the internal pressure and the inability to eject ink. In addition, if unnecessary ink adheres to the edge of the nozzle of the head, it may cause ink ejection bending or ejection failure.

  When printing is performed in such a state, the output image deteriorates, such as missing or dark portions in the output image. For this reason, it is necessary to perform maintenance for recovering the clogged or pressure loss state and removing unnecessary ink attached to the head.

  In the maintenance, in order to remove ink adhering to the head, it is generally performed that the head is rubbed with an elastic member. However, when the elastic member is rubbed, the blade of the elastic member and the head Ink may leak from the gap and ink may remain on the ejection port surface. For this reason, if the rigidity of the elastic member is further increased, the head is damaged, and the life of the head is reduced.

In relation to the above problem, it is disclosed that the ink absorber is pressed against the discharge port of the nozzle, and the discharge port is rubbed to recover the discharge port. (For example, see Patent Document 1)
Further, an ink absorber that can be brought into contact with and separated from the ink discharge port, a holding member that contacts the outer surface of the ink absorber and holds the ink absorber, and an outer surface different from the outer surface of the ink absorber And a squeezing member for squeezing the ink absorber. (For example, see Patent Document 2)
Japanese Patent Publication No. 1-30624 Japanese Patent No. 2521423

  With regard to the above-described maintenance, in the method in which the ink absorber is pressed against the discharge port of the nozzle, and the discharge port is rubbed to recover the discharge port as in Patent Document 1, the ink absorber is allowed to remove the ink to the vicinity of the absorption limit. When absorbed, there is a problem that no more ink can be absorbed and ink remains on the ejection surface.

  In addition to the method described in Patent Document 1 as described in Patent Document 2, the ink absorber includes a squeezing member that squeezes the ink outlet and then squeezes the ink absorber to absorb the ink absorbed by the ink absorber. In the method of discharging from the absorber, the absorbing power of the absorber can be recovered after rubbing the discharge port. However, if the ink absorber absorbs ink to the vicinity of the absorption limit during rubbing, it is not more than that. The problem that ink cannot be absorbed and ink remains on the ejection surface remains.

  The present invention has been made in view of the above situation. In the means for recovering a nozzle where non-ejection has occurred, the supply ink is pressurized and the ink is discharged from the ink ejection port of the print head to recover the non-ejection nozzle. After the ink is discharged, the absorbing portion of the ink absorber is brought into contact with the discharge port surface of the print head, and the absorbing portion sucks and discharges the ink absorbed by the absorbing portion with the absorbing portion. An object of the present invention is to provide an ink jet recording apparatus capable of removing ink remaining by removing the ink residue by rubbing the discharge port surface and reducing the ink emission bending due to the ink adhering to the edge of the nozzle.

The above object is achieved by the following configuration.
(Claim 1)
In an inkjet recording apparatus having a print head in which a plurality of ink ejection openings for ejecting ink to form an image is ejected onto a recording member conveyed in a predetermined direction.
Pressurize the supplied ink, discharge the ink from the ink discharge port of the print head, and after discharging the ink, the absorbent body formed of an open-cell type sponge member on the discharge port surface of the print head An ink jet recording apparatus, comprising: an absorptive part being brought into contact; and the ink absorbed by the absorbent part is sucked and discharged by a suction unit, and the ejection port surface is rubbed with the absorbent part.
(Claim 2)
2. The ink jet recording apparatus according to claim 1, wherein a pore size of an open-cell type sponge member forming the absorbing portion of the absorber is smaller than a diameter of the discharge port.
(Claim 3)
The ink jet recording apparatus according to claim 1, wherein the absorbing portion of the absorber has a length of the plurality of ink ejection port arrays.

  According to the first aspect of the invention, by pressurizing the supply ink and discharging the ink from the nozzle, bubbles and foreign matter can be discharged from the nozzle along with the discharge of the ink, and after the discharge of the ink, absorption of the absorber The ink adhering to the discharge port surface can be removed by bringing the discharge portion into contact with the discharge port surface and rubbing the discharge port surface with the abutted absorbing portion. Further, the absorbing power of the absorbing portion can be maintained by sucking and discharging the ink absorbed by the absorbing portion while performing the rubbing.

  According to the second aspect of the present invention, the pore size of the open-cell type sponge member forming the absorption part of the absorber is made smaller than the diameter of the discharge port, thereby improving the efficiency of the absorption part by capillary action. The ink can be absorbed well, and can be absorbed by the absorbing portion without leaving the ink adhering to the discharge port surface.

  According to a third aspect of the present invention, since the absorbing portion of the absorber has the length of the plurality of ink discharge port arrays, the absorbing portion collectively applies the plurality of ink discharge ports at once. The ink remaining on the discharge port surface can be easily removed in a short time.

    Embodiments relating to the recovery means and the ink jet recording apparatus of the present invention will be described below with reference to the drawings.

  FIG. 1 is a conceptual diagram of an ink jet recording apparatus A according to the present invention. The ink jet recording apparatus of the present invention is not limited to the following form.

  The print head H is mounted on the carriage 30. The carriage 30 reciprocates along the main scanning direction, reciprocates the print head H along the main scanning direction, and performs image recording by discharging ink in the process. Close contact and separation.

  Ink is supplied to the print head H from the ink cartridges A 1 and A 2 through the ink supply path 20. In this embodiment, in addition to the ink cartridge A1, an ink cartridge A2 having a lower density ink than the ink cartridge A1 is provided in order to express the gradation of the image more precisely.

  Between the ink cartridges A1 and A2 and the print head H, an ink supply valve A3, an intermediate tank A4, a pressurization stop valve A5, and a damper A6 are arranged from the upstream side.

  The intermediate tank A4 is provided with a back pressure detection sensor A41 and a pressure solenoid A42 (see FIG. 2).

  The ink supply valve A3 is a valve configured to be electrically opened and closed, such as an electromagnetic valve, and adjusts the amount of ink supplied from the ink cartridges A1 and A2 to the intermediate tank A4.

  In the present embodiment, the back pressure of the head H is controlled by the intermediate tank A4. The ink supply valve is controlled so that the amount of ink in the intermediate tank becomes constant by the back pressure detection sensor A41 provided in the intermediate tank A4.

  A pressurization stop valve A5 and a damper A6 are arranged between the intermediate tank A4 and the print head H. The pressurization stop valve A5 blocks unnecessary ink flowing from the intermediate tank A4 when the intermediate tank A4 is pressurized. The damper A6 prevents ink pressure fluctuations caused by movement of the ink supply tube due to head scanning.

  The ink is pressurized and discharged by pressing the intermediate tank A4 with a pressure solenoid A42 provided in the intermediate tank A4, so that the ink is pressurized to a positive pressure and discharged from the print head. By discharging the ink, bubbles, foreign matter, etc. in the print head are simultaneously discharged.

  The absorbing and rubbing means 1 includes an absorber 11, a rack and pinion 12 that moves the absorber 11 up and down to contact and separate the absorber 11 from the discharge port surface, and moves the absorber and the rack and pinion in the nozzle row direction. It comprises an absorber moving means (not shown) that moves in the direction, a suction pipe 13 that is a suction means, a suction pump 14, and a waste liquid tank 15 that discharges the waste liquid sucked by the suction pump 14.

  As shown in FIG. 2, the absorption rubbing means 1 moves the absorber 11 in the nozzle row direction of the print head by an absorber moving means (not shown), and the print head H is perpendicular to the nozzle row, that is, in the main scanning direction. Scanning is performed in the carriage direction, and a portion requiring absorption and rubbing is controlled to an appropriate position. When the portion requiring absorption and rubbing is in an appropriate position, the absorber 11 is moved up and down by the rack and pinion 12 so that the absorber and the outlet surface come into contact with and separate from each other. The moving means performs rubbing in the nozzle row direction to remove ink adhering to the ejection port surface.

  The ink absorbed by the absorption unit is discharged by the suction pump and maintains the absorption power of the absorption unit.

  Next, the structure of the absorber according to the present invention will be described.

  FIG. 3 is a configuration diagram of an absorber according to the present invention. The absorbent body 11 includes an absorbent section 110 formed of an open-cell type sponge, a support body 112 having a hollow structure that supports the absorbent section 110, and a shape that covers a part of the side surface and the bottom surface of the absorbent section and the support body. The base body 111 is configured. The hollow portion of the support is connected to the suction tube 13.

  The open-cell type sponge forming the absorption part 110 has a pore diameter smaller than the diameter of the discharge port. For this reason, the ink can be efficiently absorbed by the capillary phenomenon of the absorbing portion, and can be absorbed by the absorbing portion without leaving the ink adhering to the discharge port surface.

  The open-cell type sponge that forms the absorbing portion is not limited, but, for example, a polyurethane material such as a ruby cell manufactured by Toyo Polymer Co., Ltd., PVA (polyvinyl alcohol), or the like is possible.

  A functional configuration of the ink jet recording apparatus according to the present invention will be described with reference to FIG. FIG. 4 is a block diagram showing a functional configuration of the inkjet recording apparatus A according to the present invention. The same constituent elements as those shown in FIGS. 1 to 3 are denoted by the same reference numerals.

  The control means 18 includes an MPU 18A composed of a microprocessor for executing various control procedures, a ROM 18B for storing control procedures and data, a RAM 18C for temporarily storing various data, a contact rubbing timer 18D having a timer function, and a standby time. And a standby timer 18H for measuring

  Further, the control means 18 has an interface 18F that receives image data transferred from the host computer HC of the host computer, and an interface 18G that sends control signals to the print head driver 183 that drives the print head H.

  The carriage motor driver 182, discharge driving means (print head driver) 183, transport motor driver 184, absorber moving motor driver 185, pressure solenoid driver 186 and pressure stop valve driver 187 are controlled by various control signals from the control means 18. The carriage motor 3, the print head H, the transport motor 11, the absorber moving motor 121, the pressurization solenoid A42, and the pressurization stop valve A5 are driven.

  Further, the detection signals of the home position sensor 22 and the absorber sensor 142 are taken into the control means 18 via the interface 18G.

  Reference numeral 23 denotes a main power switch, which is a switch for supplying external power (AC 100 V in the present embodiment) to the ink jet recording apparatus A so as to be in an operating state.

  Reference numeral 24 denotes a sub power switch. When the main power switch 23 is turned on, the operator repeatedly presses the sub power switch 24, so that the sub power control means 25 provided in the control means 18 outputs the sub power supply 30. Is configured to repeat ON and OFF.

  Reference numeral 30 denotes a sub power supply device that receives power from an external power source via the main power switch 23, is turned on / off by a control signal from the sub power control means 25, and is directly supplied with power from the main power supply device 29. Contact rubbing means excluding (member) and other controlled means, that is, carriage motor driver 182, transport motor driver 184, absorber moving motor driver 185, pressure solenoid driver 186, pressure stop valve driver 187, capping motor 121, pressurization solenoid A42, pressurization stop valve A5 or print data, abnormality data, etc. for contacting and releasing the home position sensor 22 and the absorber 11 with respect to the discharge port surface Electric power is supplied to display means such as a liquid crystal panel for display.

  In the configuration described above, when the main power switch 23 is turned on, power is supplied from the external power source to the main power supply device 29 and the sub power supply device 30, and the ink jet recording apparatus A enters a print standby state.

  In this state, when image data from the host computer HC is captured by the control means 18 through the interface 18F, the captured image data is subjected to image processing and then converted into a control signal according to a control procedure stored on the ROM 18B. The converted control signal executes various operations such as driving the print head driver 182 via the interface 18G and performing a printing operation.

The operation of the ink jet recording apparatus according to the present invention will be described. FIG. 5 is a flowchart showing a sequence of ink pressurization, discharge, and absorber abutment rubbing operations performed in the ink jet recording apparatus.
(Operation sequence)
Step S1. The pressure solenoid A42 is actuated on the head to be recovered, and the intermediate tank A4 is pressed.
Step S2. The ink is discharged from the nozzle, and bubbles, foreign matter, etc. are discharged.
Step S3. The pressurization stop valve A5 is operated to stop the outflow of ink, and the operation of the pressurization solenoid is released.
Step S4. Wait until the ink pressure in the head is near atmospheric pressure.
Step S5. The absorber 11 adjusted to the position of the head to be recovered is moved upward by the rack and pinion 12, and the absorber 110 of the absorber 11 and the discharge port surface are brought into contact with each other.
Step S6. The abutting absorber is slid in the nozzle row direction of the head by the absorber moving means, and the suction pump 14 is operated simultaneously.
Step S7. Rub to a predetermined position on the discharge port surface with the absorber.
Step S8. The absorber is moved away from the discharge port surface and moved to the absorber standby position.

  In the present embodiment, the shape of the absorber is a shape in which a part of the nozzle row of the head abuts, but may be a shape that abuts on the entire nozzle row.

  FIG. 6 shows an example of an absorbent body shaped so as to be in contact with the entire nozzle array. In FIG. 6, the absorption part 110 of the absorber 11 has such a length that it can abut on the entire nozzle on the discharge port surface. The rubbing of the discharge port surface rubs in a direction orthogonal to the nozzle row direction shown in FIG. The movement for rubbing can be performed by moving the head in the main scanning direction by the carriage 30 while the absorber is stopped. Alternatively, it is also possible to use a moving means that moves the absorber in a direction orthogonal to the nozzle row direction while the head is stopped. The ink absorbed in the absorption unit is discharged to the waste liquid tank 15 by the suction pump 14 through the support 112 and the suction pipe 13.

  FIG. 7 shows an example in which the number of support bodies 112 is increased to three so that the ink absorbed in the absorbing section 110 shown in FIG. 6 can be sucked and discharged quickly and substantially uniformly throughout the absorbing section. The number of supports to be added is not limited to this.

  In this embodiment, the print head of the shuttle type ink jet recording apparatus is used, but the present invention can also be applied to a line head, a multi head, and the like of the line type ink jet recording apparatus.

  FIG. 8 is a schematic view when the recovery means according to the present invention is applied to a line head and a multi head of a line type ink jet recording apparatus. Both the line head type and multi-head type absorber can be moved in the recording material transport direction and nozzle row direction by a moving means (not shown). After the supply ink is pressurized and discharged, the absorber moves to the nozzle position. The contact rubbing recovery operation is performed.

  As described above, the supply ink pressurizing / discharging operation, the contact rubbing operation by the absorber, the suction unit and the recovery operation sequence, discharge bubbles, foreign matters, and the like in the nozzle in the recovery of the non-ejection nozzle. And a recovery method capable of reducing the bending of the ejection of ink due to the remaining ink on the ejection port surface adhering to the edge of the nozzle.

1 is a conceptual diagram of an ink jet recording apparatus according to the present invention. It is a block diagram of an ink supply path and absorption rubbing means. It is a block diagram of the absorber which concerns on this invention. It is a control block diagram of the ink jet recording apparatus according to the present invention. It is a flowchart showing the sequence of recovery operation | movement. It is a figure showing another form of the absorber concerning the present invention. It is a figure showing another form of the absorber concerning the present invention. It is a schematic diagram when the recovery means according to the present invention is applied to a line type ink jet recording apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Absorption rubbing means 11 Absorber 110 Absorbing part 111 Base body 112 Support body 12 Rack and pinion 13 Suction pipe 14 Suction pump 15 Waste liquid tank 20 Ink supply path 30 Carriage 40 Moisturizing cap A1, A2 Ink cartridge A3 Ink supply valve A4 Intermediate tank A41 Back pressure detection sensor A42 Pressure solenoid A5 Pressure stop valve A6 Damper H Print head

Claims (3)

In an inkjet recording apparatus having a print head in which a plurality of ink ejection openings for ejecting ink to form an image is ejected onto a recording member conveyed in a predetermined direction.
Pressurize the supplied ink, discharge the ink from the ink discharge port of the print head, and after discharging the ink, the absorbent body formed of an open-cell type sponge member on the discharge port surface of the print head An ink jet recording apparatus, comprising: an absorptive part being brought into contact; and the ink absorbed by the absorbent part is sucked and discharged by a suction unit, and the ejection port surface is rubbed with the absorbent part. 2. The ink jet recording apparatus according to claim 1, wherein a pore size of an open-cell type sponge member forming the absorbing portion of the absorber is smaller than a diameter of the discharge port. The ink jet recording apparatus according to claim 1, wherein the absorbing portion of the absorber has a length of the plurality of ink ejection port arrays.

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