JP2008194981A - Head maintenance method - Google Patents

Abstract

A head maintenance method capable of high-quality printing while maintaining good throughput without incurring waste of cost.
A cleaning process in which a head cap 63 is brought into close contact with a nozzle forming surface 21a of a print head 21 to suck the ink from the ink nozzles, and thereafter the nozzle forming surface 21a of the print head 21 is wiped with a wiper 51. In this head maintenance method, a wiping process for wiping the nozzle forming surface 21a with the wiper 51 is performed separately from the cleaning process.
[Selection] Figure 7

Description

  The present invention relates to a head maintenance method for cleaning a nozzle forming surface of a print head of an ink jet printer using a wiper.

In general, an ink jet printer is configured such that a print head mounted on a carriage that can reciprocate ejects ink droplets from a plurality of nozzles to desired positions to perform printing.
By the way, foreign matter such as ink and dust may adhere to the nozzle forming surface of the print head during printing, and therefore it is necessary to clean the print head outside the print area for appropriate maintenance.

Therefore, in an inkjet printer, a head maintenance mechanism that performs a maintenance operation of the print head is disposed in a maintenance area that is out of the print area by the print head, and the print head is cleaned by the head maintenance mechanism. ing.
The maintenance mechanism includes a wiper for wiping the nozzle formation surface of the print head, a head cap that closely contacts the nozzle formation surface of the print head and receives ink discharged from the ink nozzles, and a suction pump that sucks the inside of the head cap. Yes.
In this cleaning by the maintenance mechanism, a head cap is brought into close contact with the nozzle formation surface of the print head, and the inside is sucked to suck ink in a thickened state from the ink nozzle, and dirt on the nozzle formation surface of the print head is wiped off. A wiping process for wiping is performed.
In addition, in the ink jet printer having the maintenance mechanism, a flushing process is performed in which a predetermined amount of ink is ejected from the ink nozzle into the head cap before the start of printing in order to form an ink meniscus at the ink nozzle of the print head. In order to prevent clogging of the ink nozzles, a capping process for protecting the head cap by closely contacting the nozzle forming surface of the print head is also performed after the printing is stopped.
JP-A-5-169668

By the way, when the capping process after printing is repeated in a state where the ink is adhered to the nozzle formation surface, when the nozzle formation surface and the head cap are separated from each other, the ink scatters at these contact points. There is a problem in that the scattered ink makes the periphery dirty or the ink scattered on the nozzle forming surface adheres to the ink nozzles, resulting in ink ejection failure and deterioration of printing quality.
In this case, it is only necessary to wipe the ink adhering to the nozzle forming surface by the wiping process in this cleaning by frequently performing the above-described cleaning, but the cleaning is also performed by other processes such as an ink suction process. It will affect the throughput. In addition, if cleaning is frequently performed, ink is sucked more than necessary by the ink suction process and discharged, leading to waste of ink cost.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a head maintenance method that enables high-quality printing while maintaining good throughput without incurring waste of cost.

  In order to achieve the above object, the head maintenance method of the present invention sucks ink from the ink nozzle by sucking the head cap closely attached to the nozzle forming surface of the print head, and then the nozzle of the print head. A head maintenance method for performing a cleaning process for wiping the formation surface with a wiper, wherein a wiping process for wiping the nozzle formation surface with the wiper is performed separately from the cleaning process.

  According to this head maintenance method, since the wiping process for wiping the nozzle forming surface with a wiper is performed separately from the cleaning process, the nozzle forming surface can be wiped without performing ink suction. Accordingly, it is possible to perform high-quality printing by wiping off ink adhering to the nozzle formation surface while maintaining good throughput without incurring waste of ink cost due to discharging ink more than necessary.

  In addition, it is preferable that the wiping process is performed during a draining process in which the waste ink stored in the head cap is removed from the head cap by a flushing process in which ink is ejected from the ink nozzles of the print head into the head cap.

  According to this head maintenance method, since the wiping process is performed when the waste ink accumulated by the flushing process is drained, high quality printing performance can be obtained while maintaining a good throughput.

  Further, it is preferable that the wiping process is performed during the draining process that is performed during a pause operation in which the head cap is brought into close contact with the nozzle formation surface of the print head.

  According to this head maintenance method, since the wiping process is performed during the draining process performed in the pause operation, high quality printing performance can be obtained while maintaining a good throughput.

  Further, it is preferable that the draining process accompanied by the wiping process is performed when the amount of discharged ink in the head cap is a predetermined amount or more.

  According to this head maintenance method, since the wiping process is performed when the amount of discharged ink is equal to or greater than the predetermined amount, it is possible to minimize the liquid discharge process accompanied by the wiping process and maintain the throughput even better. In addition, high-quality printing performance can be obtained.

Hereinafter, a head maintenance method according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.
1 is an external perspective view of an ink jet printer to which a head maintenance method according to an embodiment of the present invention is applied, FIG. 2 is a perspective view of a state in which a printer case is removed from the ink jet printer shown in FIG. 1, and FIG. FIG. 4 is an exploded perspective view of the head maintenance mechanism shown in FIG. 2, and FIGS. 5 and 6 are perspective views of main parts of the head maintenance mechanism shown in FIG.

  The ink jet printer 1 according to the present embodiment performs color printing on roll paper using a plurality of types of color ink liquids. As shown in FIG. 1, a roll paper is placed on the front surface of a printer case 2 that covers the printer body. A cover 5 and an ink cartridge cover 7 are provided to be freely opened and closed. Further, on the front surface of the printer case 2, a power switch 3 and a feed switch, an indicator, and the like are also arranged.

When the roll paper cover 5 is opened, the paper storage unit 13 that stores the roll paper 11 that is printing paper is opened, and the paper can be replaced.
When the ink cartridge cover 7 is opened, the cartridge mounting portion 15 is opened, and the ink cartridge 17 can be attached to and detached from the cartridge mounting portion 15.

  The ink cartridge 17 is a cartridge case containing a plurality of color ink packs. In the case of the ink jet printer 1 of the present embodiment, the ink cartridge 17 is pulled out by a predetermined distance in front of the cartridge mounting portion 15 in conjunction with the operation of opening the ink cartridge cover 7.

Each ink pack in the ink cartridge 17 is inserted and connected to the ink supply port of the ink pack when the ink cartridge 17 is mounted on the cartridge mounting portion 15. An ink flow path 31 fixed in the printer case 2 is connected to the ink supply needle of the cartridge mounting portion 15, and one end of a flexible ink supply tube 33 is connected to the ink flow path 31. .
The other end of the ink supply tube 33 is connected to a damper unit 34 provided on the carriage 23. The damper unit 34 is connected to a back pressure adjustment unit 35 connected to the inkjet print head 21.

  As shown in FIG. 2, a carriage 23 on which a print head 21 is mounted is provided above the paper storage unit 13 in the printer case 2. The carriage 23 is supported by a guide member 25 extending along the width direction of the roll paper 11 so as to be movable in the paper width direction, and an endless belt 26 a extending in the width direction of the roll paper 11 and the endless belt 26 a. The carriage motor 26b that drives the printer 11 is capable of reciprocating in the width direction of the roll paper 11 above the platen 28, which is a printing area.

  As shown in the drawing, the upper position of the cartridge mounting portion 15 that is out of the printing area is a standby position (maintenance area) of the carriage 23 that reciprocates. A head maintenance mechanism 40 that performs a maintenance operation of the print head 21 exposed on the lower surface of the carriage 23 is disposed below the standby position.

  As shown in FIGS. 3 to 6, the head maintenance mechanism 40 of the present embodiment includes a head cap mechanism 60 for sealing the nozzle formation surface 21 a of the print head 21 and a wiping for the nozzle formation surface 21 a. A wiper mechanism 50, an absorbing member 100 that absorbs adhering matter adhering to the capturing member 24 described later, and an ink suction mechanism 70 for sucking residual ink from the head cap mechanism 60 are provided.

  As shown in FIG. 6, the absorbing member 100 is provided on the side of the head cap 63 in the head cap mechanism 60, and moves to the capping position together with the head cap mechanism 60 so that the upper end edge 101 a contacts the capturing member 24. The first absorbing member 101 having a substantially rectangular plate shape and the first absorbing member 101 provided below the head cap mechanism 60 and moved to the retracted position with the head cap mechanism 60 retracted from the capping position. And a second absorbing member 102 that can come into contact with the contact portion 101b.

  The head cap mechanism 60, the wiper mechanism 50, the first absorption member 101, and the ink suction mechanism 70 are driven by a pump motor 81 via a power transmission mechanism 80. These parts are attached to a housing 41 that can be attached to and detached from the printer body.

As shown in FIG. 4, the wiper mechanism 50, the head cap mechanism 60, and the first absorbing member 101 are provided side by side in the reciprocating direction of the carriage 23 (the left-right direction in FIG. 4). The cap mechanism 60 is provided on the rear side of the printer (the front side in FIG. 4).
A power transmission mechanism 80 is disposed so that the head cap mechanism 60, the wiper mechanism 50, the first absorbing member 101, and the ink suction mechanism 70 can be interlocked.

  That is, the power transmission mechanism 80 is constituted by a gear train composed of a plurality of gears, and the head cap mechanism 60, the first absorbing member 101, and the wiper mechanism 50 are moved in the reciprocating direction of the print head 21 by the driving force from the pump motor 81. The ink suction mechanism 70 is operated while moving forward and backward in a direction orthogonal to the vertical direction (vertical direction in FIG. 4).

  The ink suction mechanism 70 is a tube pump in which one end of the tube 72 is connected to the head cap mechanism 60 and the other end is connected to the waste ink introducing portion of the ink cartridge 17. When the ink suction mechanism 70 is driven, Ink is sucked from the nozzles of the print head 21 via the head cap mechanism 60 and discharged to the waste ink storage chamber of the ink cartridge 17.

A cylindrical cam 82 is connected to the final stage (the wiper 51 and the head cap 63 side) of the gear train constituting the power transmission mechanism 80.
The cylindrical cam 82 is configured by fitting a lower cam wheel 83 and an upper cam wheel 84, an intermittent gear 85, and a friction gear 86 on a support shaft 43 that is suspended from the housing 41.

The lower cam wheel 83 and the upper cam wheel 84 have a cam groove for sliding the wiper mechanism 50 and a cam groove for sliding the head cap mechanism 60 shifted on the outer peripheral surfaces formed by combination. Is formed.
On the bottom surface of the lower cam wheel 83, an engagement protrusion is provided to engage with an arc groove having a predetermined length formed on the bottom surface of the housing 41. The lower cam wheel 83 is finitely rotated.
On the upper surface of the upper cam wheel 84, an engaging protrusion is provided to engage with an arc groove of a predetermined length formed on the intermittent gear 85, and the upper cam wheel 84 is rotated following the intermittent gear 85.
A friction gear 86 that frictionally engages with the upper surface of the intermittent gear 85 is disposed above the intermittent gear 85, and the friction gear 86 is pressed and biased toward the intermittent gear 85 by a coil spring 88.

The slider 64 of the head cap mechanism 60 is provided with a cam follower 66 that engages with the cam groove of the cylindrical cam 82, and the slider 52 of the wiper mechanism 50 is provided with a cam follower 54 that engages with the cam groove of the cylindrical cam 82. ing.
Thus, as the cylindrical cam 82 rotates, the slider 64 of the head cap mechanism 60 and the slider 52 of the wiper mechanism 50 slide according to the corresponding cam grooves.

  The head cap mechanism 60 includes a slider 64 and a head cap 63 fixed to the cap holder 62, as shown in FIGS. The slider 64 is formed in a case shape, and the insertion portion 65 is slid so as to slide in a direction orthogonal to the guide member 25, that is, in a direction approaching or separating from the nozzle forming surface 21 a of the print head 21. It is supported by a guide shaft 42 that is suspended from the housing 41.

  A cap holder 62 having a head cap 63 fixed to the tip portion is held in the upper end recess of the slider 64 so as to move forward and backward with respect to the slider 64. The head cap 63 is formed of a box-shaped rubber having an opening large enough to seal the nozzle forming surface 21a of the print head 21, and a multi-layer absorbent material is attached to the opening. It has been.

  The wiper mechanism 50 includes a slider 52 and a wiper 51 as shown in FIGS. The slider 52 is formed in a box shape, and a slide portion 53 is supported and guided by a guide portion 44 provided in the housing 41 so as to slide in the same direction as the slider 64 of the head cap mechanism 60. A wiper 51 made of a rubber plate material, which is an elastic material, is embedded in the tip portion of the slider 52.

  The slider 52 can move between a position where the wiper 51 is most retracted inside the maintenance mechanism 40 (a retreat position) and a wiping position where the wiper 51 performs a process of wiping off dirt on the nozzle forming surface 21a. It is like that. As shown in FIG. 7, the wiping position is a position where the tip of the wiper 51 has moved to the print head 21 side by an amount s that protrudes from the nozzle forming surface 21 a and rubs against the nozzle forming surface 21 a of the print head 21. It is like that. Thereby, the wiper 51 can wipe off foreign matters such as ink adhering to the nozzle forming surface 21a. Depending on the type of ink, the wiper 51 may be formed of soft plastic or the like.

  Further, as shown in FIG. 8, on the maintenance area side (right side in FIG. 8) with respect to the nozzle formation surface 21 a of the print head 21, the wiper 51 of the wiper mechanism 50 moves to the wiper mechanism 50 when the print head 21 moves to the print area side. A capturing member 24 that contacts and wipes off the adhered matter that adheres to the wiper 51 is provided.

  The capturing member 24 is formed in a thin plate shape, and a scraping portion 24a capable of abutting on the side surface of the wiper 51 on the head cap mechanism 60 side protrudes from the tip portion. Further, the tip of the capturing member 24 is disposed at a position slightly retracted from the nozzle forming surface 21 a of the print head 21. As a result, the capture member 24 does not come into contact with the roll paper 11 on the platen 28 when the carriage 23 moves in the print area.

  In the inkjet printer 1, the print head 21 is cleaned by the maintenance mechanism 40. This cleaning is performed at a predetermined timing or at the time of a user's operation. The head cap 63 is brought into close contact with the nozzle forming surface 21a of the print head 21, and the inside is sucked by the ink suction mechanism 70 for printing. An ink suction process for sucking thickened ink from the ink nozzles of the head 21 and a wiping process for wiping the dirt on the nozzle forming surface 21a of the print head 21 with the wiper 51 are performed.

  Further, in the ink jet printer 1 having the maintenance mechanism 40, a predetermined amount of ink is applied from the ink nozzles of the print head 21 before the start of printing or periodically in order to form an ink meniscus at the ink nozzles of the print head 21. A flushing process for discharging the ink into the head cap 63 and a capping process for protecting the head cap 63 by closely contacting the nozzle forming surface 21a of the print head 21 are performed after the printing is stopped to prevent clogging of the ink nozzles.

  In the maintenance mechanism 40, an empty suction process (drainage process) for sucking and discharging the waste ink accumulated in the head cap 63 by the above-described flushing process by the ink suction mechanism 70 is performed. This idle suction process is performed when the inkjet printer 1 is started, during a regular flushing process that is periodically performed, or during a pause operation in which printing by the print head 21 is suspended.

Next, the printing pause operation of the print head 21 in the inkjet printer 1 will be described with reference to the flowchart shown in FIG.
After a print head 21 finishes printing or after an automatic cutting mechanism (not shown) that automatically cuts the roll paper 11 is activated, a pause operation is started when a predetermined time has elapsed.

  When the pause operation is started, it is determined whether or not the flushing amount in the head cap, which is the amount of discharged ink stored in the head cap 63 by the flushing process, is equal to or greater than a predetermined value (step S01). . The flushing amount is calculated from the amount of ink discharged by one flushing process and the number of flushing processes. Further, the predetermined value is determined from an allowable storage amount of discharged ink in the head cap 63.

  When it is determined that the flushing amount in the head cap is equal to or greater than a predetermined value, an idle suction process is performed (step S02).

After the idle suction process, a flushing process is performed (step S03), and then a capping is performed to protect the nozzle forming surface 21a by sealing the nozzle forming surface 21a by bringing the head cap 63 into close contact with the nozzle forming surface 21a of the print head 21 (step S04). ).
If it is determined that the flushing amount in the head cap is less than the predetermined value, capping is performed to protect the nozzle formation surface 21a by sealing the nozzle formation surface 21a by bringing the head cap 63 into close contact with the nozzle formation surface 21a of the print head 21 (step). S04).

Next, the idle suction processing will be described along the flowchart shown in FIG.
The idle suction process is started at the time of initialization when the power of the ink jet printer 1 is turned on, at the time of the flushing process that is periodically performed, or at the time of the pause operation.
When the idle suction process is started, it is determined whether or not the idle suction process is started by the aforementioned pause operation (step S11).

When it is determined that the idle suction process has been started by the pause operation, a wiping process (steps S12 to S16) is performed.
If it is determined that the idle suction process has been started by other than the pause operation, the process proceeds to the idle suction operation (steps S17 and S18).

In the wiping process, first, the carriage 23 on which the print head 21 is mounted is moved to the home position (step S12).
Next, the wiper 51 at the retracted position is raised and moved to the wiping position moved to the print head 21 side by the amount of protrusion s from the nozzle forming surface 21a of the print head 21, as shown in FIG. 7 (step S13).

Next, the print head 21 is moved toward the print area side (left side in FIG. 7), and the print head 21 is disposed at the wiping start position where the wiper 51 contacts the front end portion in the movement direction (step S14).
After the print head 21 is temporarily stopped at the wiping start position, the print head 21 is moved toward the print area to the wiping end position where the moving rear side end of the print head 21 passes through the wiper 51 (step S15). .

In this way, as shown in FIG. 8, the wiper 51 slides on the nozzle formation surface 21a of the print head 21 with a deflection amount corresponding to the protrusion amount s, and wipes the ink adhering to the nozzle formation surface 21a. Wipe by transferring to 51 itself.
When the print head 21 is moved to the wiping end position, the wiper 51 at the wiping position is lowered to the retracted position (step S16).

Thereafter, when the print head 21 is further moved to the print area side, the idle suction operation is started (step S17).
Specifically, the ink suction mechanism 70 is driven, the waste ink stored in the head cap 63 is sucked, discharged into the waste ink storage chamber of the ink cartridge 17, and the head cap 63 is emptied (step S18). .

  As described above, according to the head maintenance method according to the above embodiment, the wiping process for wiping the nozzle forming surface 21a with the wiper 51 is performed separately from the cleaning process, and thus the nozzle forming surface 21a is wiped without performing ink suction. can do. As a result, it is possible to perform high-quality printing by wiping off ink adhering to the nozzle forming surface 21a while maintaining good throughput without incurring waste of ink cost due to discharging ink more than necessary. .

In particular, the wiping process is performed during the idle suction process that is performed when the amount of discharged ink accumulated by the flushing process is greater than or equal to a predetermined amount during the pause operation, so that high-quality printing performance can be obtained while maintaining good throughput. Can do.
Moreover, in the idle suction operation (step S18) during the idle suction process, the print head 21 is moved to the print area in order to avoid interference with the head cap 63 that sucks and discharges the stored ink. Since the wiping process is performed at the time of the movement, it is not necessary to add another operation for moving the print head 21 for the wiping process.

In the above embodiment, the wiping is performed by moving the wiper 51 in the proximity / separation direction with respect to the print head 21. However, the print head 21 may be moved in the proximity / separation direction with respect to the wiper 51.
Further, the configuration of the wiper, the capturing member, the absorbing member, the head cap and the like related to the head maintenance mechanism 40 is not limited to the configuration of the above embodiment, and various forms can be taken based on the gist of the present invention. Of course.

1 is an external perspective view of an ink jet printer to which a head maintenance method according to an embodiment of the present invention is applied. It is a perspective view of the state where the printer case was removed from the ink jet printer. It is a whole perspective view of a head maintenance mechanism. It is a disassembled perspective view of a head maintenance mechanism. It is a principal part perspective view of a head maintenance mechanism. It is a principal part perspective view of a head maintenance mechanism. It is a principal part front view explaining operation | movement of a head maintenance mechanism. It is a principal part front view explaining operation | movement of a head maintenance mechanism. It is a flowchart explaining a pause operation. It is a flowchart explaining an empty suction process.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Inkjet printer, 21 ... Print head, 21a ... Nozzle formation surface, 51 ... Wiper, 63 ... Head cap.

Claims (4)

A head maintenance method in which a cleaning process is performed in which ink is sucked from the ink nozzles by adhering and sucking a head cap to the nozzle formation surface of the print head, and then the nozzle formation surface of the print head is wiped with a wiper. And
In addition to the cleaning process, a wiping process for wiping the nozzle forming surface with the wiper is performed.   The wiping process is performed during a draining process in which the waste ink stored in the head cap is removed from the head cap by a flushing process in which ink is ejected from the ink nozzles of the print head into the head cap. Item 2. The head maintenance method according to Item 1.   3. The head maintenance method according to claim 2, wherein the wiping process is performed during the draining process performed during a pause operation in which the head cap is brought into close contact with the nozzle formation surface of the print head.   4. The head maintenance method according to claim 2, wherein when the amount of discharged ink in the head cap is greater than or equal to a predetermined amount, the draining process accompanied by the wiping process is performed. 5.

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