JP2011042047A - Inkjet recording apparatus and spare ejection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To overcome the problem that a throughput decreases due to increase in a carriage scanning width by the spare ejection operation in consequence of the need of the operation during printing to a cap part or the like with a suction mechanism if there is an ink liable to be deposited. <P>SOLUTION: An ink nozzle liable to cause deposition is arranged at a position relatively near the cap, and spare ejection during the recording operation is carried out to a position relatively near an image forming region in the cap part. The carriage scanning width at the time of spare ejection of the ink liable to be deposited in the cap part is shortened, so that the throughput is improved while deposition is avoided. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an inkjet recording apparatus that records an image by ejecting ink droplets and a preliminary ejection method thereof, and more particularly, to an inkjet recording apparatus that includes a recording head and a means for capping the recording head and a method for preventing a decrease in ejection performance thereof.

  Inkjet recording devices have a mechanism of recording by ejecting liquid ink from minute nozzles, and maintenance technology for maintaining the proper ink ejection state in the recording head is important for recording high-quality images. Technology. For example, the viscosity rises due to the evaporation of ink moisture in the nozzles during non-operation, and the recording head ejection performance decreases when operation resumes (such as unstable ink ejection direction and ejection speed, non-ejection of ink, etc.) ).

  For this reason, the conventional ink jet recording apparatus performs a nozzle maintenance operation called preliminary ejection for the purpose of restoring or maintaining the ejection performance of the nozzle.

  The preliminary discharge is roughly divided into the following two operations.

  (A) When performing the recording operation from the non-recording operation state, the recording is performed after the preliminary ejection conditions corresponding to the non-operation time are selected and the predetermined number of preliminary ejections are performed to discharge the thickened ink in the nozzles. Control to start operation.

  (B) During the recording operation, not all the nozzles of the recording head are always used for image recording. Therefore, the ink in the nozzles gradually evaporates and thickens, particularly in the nozzles that do not eject ink frequently. , Ejection failure occurs. In order to prevent such a phenomenon, the nozzle discharge performance is recovered and maintained by performing preliminary discharge at a predetermined timing between scans of the recording head during image recording (hereinafter, this operation is performed to perform preliminary discharge). Called).

  In such a preliminary ejection operation, ink is ejected to a cap provided to seal the ejection port forming surface or a preliminary ejection ink receiving portion provided at a position facing the scanning path of the recording head.

  The cap plays a role of covering and protecting the surface of the recording head from the outside in order to prevent the peripheral portion of the nozzle on the surface of the recording head and the ink in the nozzle from adhering due to drying and causing ejection failure and dust and the like from adhering. At the same time, it is also used when performing a suction recovery operation in which the inside of the cap is decompressed and the ink in the nozzles is discharged while the recording head is sealed.

  On the other hand, the preliminary discharge ink receiving portion is generally configured to have a waste ink absorbing portion or the like below the receiving portion to hold the discharged ink accumulated in the ink receiving portion. Yes. The flow path that guides the ink discharged to the ink receiving portion to the waste ink absorbing portion is formed in a shape that does not prevent natural fall of the ink due to gravity.

  However, in the ink jet recording apparatus using an ink having lower solubility than that of the conventional ink, when preliminary ejection is continuously performed on the ink receiving portion, the ink accumulates on the ink receiving portion and the flow path, and the deposits pass through the flow path. May be blocked. In this case, problems such as deposits overflowing to the peripheral portion and the area around the ink receiving portion becoming dirty or coming into contact with the ejection port forming surface of the recording head may occur.

  For this reason, in an ink jet recording apparatus that uses ink having lower solubility than conventional ink, in order to prevent the above-described problem, the ink collected by the preliminary discharge is sucked rather than the ink receiving portion that is deposited by the preliminary discharge. Performing preliminary discharge only in the cap that can be discharged by the mechanism is an effective control method from the viewpoint that no new mechanism or control is required while avoiding deposition.

  However, limiting the position where the preliminary discharge operation is performed to the cap causes problems such as an increase in time required for the preliminary discharge operation. In particular, the preliminary flow discharge (b) is performed between recording scans of the recording head. Therefore, if it is necessary to perform preliminary discharge discharge, the preliminary discharge is performed after the recording head is moved from the recording area to the cap. Become.

  In the case of an ink jet recording apparatus that uses ink that does not have the risk of accumulation, for example, as disclosed in Patent Document 1, a preliminary dischargeable area is provided in the vicinity of the scanning direction outside the image forming area, and the preliminary discharge is performed in that area. By doing so, the scanning distance required for preliminary ejection can be reduced to a minimum.

JP 2003-291372 A

  However, in an ink jet recording apparatus that uses ink that easily accumulates, it is necessary to perform preliminary ejection in an area having a mechanism that can discharge stagnant ink such as a cap, and this is realized by the technique disclosed in Patent Document 1. However, the number of components increases and the mechanism and control of the recording apparatus become complicated. In particular, in a recording apparatus having a multi-colored ink structure or having a plurality of recording element plates, there is a problem that the influence is large and hinders downsizing and cost reduction.

  The present invention has been made to solve the above-described problems, and prevents accumulation of ink with an inexpensive configuration that does not require a complicated mechanism or control, and suppresses an increase in time required for the preliminary ejection operation. It is an object of the present invention to provide an ink jet recording apparatus capable of performing the above and a preliminary discharge method thereof.

  The present invention relates to an ink jet recording apparatus that records an image by ejecting ink onto a recording medium using a single or a plurality of recording heads in which a plurality of ink ejection openings are arranged in the scanning direction. Ejecting means for preliminarily ejecting the ink separately from image recording and capping means capable of sealing the nozzle array forming surface of the recording head with a single or a plurality of caps, and relatively dissolving among the inks A single or a plurality of inks having low properties are arranged at the ink discharge ports located relatively close to the cap with respect to the scanning direction, and the single or a plurality of inks having low properties are reserved during the recording operation. When discharging, preliminary discharge is performed on the in-cap region that is relatively close to the image forming region with respect to the scanning direction.

  According to the present invention, in an ink jet recording apparatus that uses ink that is easily deposited, ink nozzles that are likely to be deposited are disposed at positions relatively closer to the cap side, and preliminary ejection during the recording operation is relatively imaged within the cap portion. The position is close to the formation area. As a result, since the cap portion has an ink discharge mechanism, ink accumulation can be avoided, and the carriage scanning width when ink is preliminarily ejected to the cap portion can be shortened. That is, ink can be prevented from being deposited with an inexpensive configuration that does not require a complicated mechanism and control, and the throughput can be improved by suppressing the time required for the preliminary ejection operation.

It is the figure which looked at the recording apparatus from the upper right part for demonstrating the internal mechanism of a recording apparatus. FIG. 6 is a perspective view illustrating a cleaning unit of the recording apparatus. 1 is a block diagram schematically showing an overall configuration of an electrical circuit in an embodiment of the present invention. FIG. 5 is a perspective view illustrating a state where an ink tank is attached to the head cartridge. FIG. 2 is a schematic diagram of a recording head and ink discharge ports in a recording apparatus used in an embodiment of the present invention. FIG. 5 is a schematic diagram illustrating a preliminary flow discharge operation in the recording apparatus used in the embodiment of the present invention. FIG. 2 is a schematic diagram of a recording head and ink discharge ports in a recording apparatus used in an embodiment of the present invention. FIG. 2 is a schematic diagram of a recording head and ink discharge ports in a recording apparatus used in an embodiment of the present invention. FIG. 5 is a schematic diagram illustrating a preliminary flow discharge operation in the recording apparatus used in the embodiment of the present invention. FIG. 5 is a schematic diagram illustrating a preliminary flow discharge operation in the recording apparatus used in the embodiment of the present invention. FIG. 2 is a schematic diagram of a recording head and ink discharge ports in a recording apparatus used in an embodiment of the present invention. FIG. 5 is a schematic diagram illustrating a preliminary flow discharge operation in the recording apparatus used in the embodiment of the present invention. FIG. 5 is a schematic diagram illustrating a preliminary flow discharge operation in the recording apparatus used in the embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a configuration of each mechanism unit in a recording apparatus applied in the present embodiment. The recording apparatus main body in the present embodiment can be generally classified into a paper feed unit, a paper transport unit, a paper discharge unit, a carriage unit, a cleaning unit, and the like. Hereinafter, the configuration and operation of each unit will be described.

Mechanism Unit The sheet feeding unit has a mechanism for separating the recording media stacked on the pressure plate M2010 on which the recording media are stacked one by one and feeding them to the platen M3040 side. The paper transport unit includes a roller pair including a transport roller M3060 that sandwiches and transports the fed recording medium toward a recording area by the recording head, and a pinch roller M3070 provided opposite to the transport roller M3060, and a drive source for the transport roller M3060. A transfer motor E0002 and the like. The paper discharge unit includes a paper discharge roller M3110 for discharging the recording medium from the recording area, and a plurality of spur rollers cooperating therewith.

  The carriage unit includes a carriage M4000 for mounting a recording head, and the carriage M4000 is supported by a guide shaft M4020 and a guide rail M1011. The guide shaft M4020 guides and supports the carriage M4000 to reciprocate in a direction orthogonal to the recording medium conveyance direction. The carriage M4000 is driven via a timing belt M4041 by a carriage motor (not shown) attached to the chassis M1010.

  When an image is formed on the recording medium in the above configuration, the recording position in the row direction of the image is positioned by conveying a recording medium by a pair of rollers including a conveyance roller M3060 and a pinch roller M3070. For the position of the image in the column direction, the carriage M4000 is moved in a direction perpendicular to the transport direction by the carriage motor, and the recording head is arranged at the target image forming position. The positioned recording head ejects ink to the recording medium in accordance with a signal from the electric control board E0014. In the recording apparatus of the present embodiment, main scanning in which the carriage M4000 moves in the column direction while performing recording by the recording head and sub-scanning in which the recording medium is conveyed in the row direction by the conveyance roller M3060 are alternately repeated. As a result, an image is formed on the recording medium.

Cleaning Unit The cleaning unit shown in FIG. 2 is a mechanism for cleaning the recording head H1001. A pump M5000, a cap M5010 for suppressing the drying of the ink of the recording head, a blade M5020 for cleaning the nozzle forming surface of the recording head, and a cleaning motor E0003 for generating a driving force for driving them are also provided.

  The cleaning motor E0003 is provided with a one-way clutch (not shown). The pump M5000 is operated by rotation in one direction, and the blade M5020 is moved and the cap M5010 is moved up and down by rotation in the other direction. ing.

  For example, a tube pump is used as the suction pump M5000. This includes, for example, a curved surface forming member having a curved surface formed along at least a part of the flexible tube, a roller capable of pressing the flexible tube against the member, and a rotatable roller support for supporting the roller. Part. That is, by rotating the roller support portion in a predetermined direction, the roller rotates while crushing the flexible tube on the curved surface forming member. Along with this, a negative pressure is generated in the sealed space formed by the cap M5010, the ink is sucked from the discharge port, and is drawn from the cap M5010 into a tube or a suction pump. On the other hand, the drawn ink is further transferred toward a waste ink absorber provided in the lower case M7080.

  Note that an absorber M5011 is provided in an inner portion of the cap M5010 in order to reduce ink remaining on the nozzle formation surface of the recording head H1001 after suction. In addition, with the cap M5010 opened, the ink remaining in the cap M5010 or the absorber M5011 is sucked. By doing so, consideration is given to avoiding the adverse effects of the ink remaining on the nozzle forming surface sticking. Here, an air release valve (not shown) is provided in the middle of the ink suction path, and when the cap M5010 is released from the nozzle formation surface in advance, a sudden negative pressure is generated on the nozzle formation surface. It is preferable not to do so.

  The suction pump M5000 can be operated not only for suction recovery, but also for discharging ink received in the cap M5010 by a preliminary ejection operation performed in a state where the cap M5010 faces the nozzle formation surface. That is, by operating the suction pump M5000 when the pre-discharged ink held in the cap M5010 reaches a predetermined amount, the ink held in the cap M5010 is transferred to the waste ink absorber through the tube. Can send.

Next, the control system in the present embodiment will be described.

  FIG. 3 is a block diagram for schematically explaining the overall configuration of the control system in the present embodiment. The recording apparatus applied in the present embodiment is mainly configured by a carriage substrate E0013, a main substrate E0014, a power supply unit E0015, a front panel E0106, and the like. Here, the power supply unit E0015 is connected to the main board E0014 and supplies various driving power supplies.

  The carriage substrate E0013 is a printed circuit board unit mounted on the carriage M4000, and functions as an interface that exchanges signals with the recording head H1001 and supplies head drive power through the head connector E0101. Further, a change in the positional relationship between the encoder scale E0005 and the encoder sensor E0004 is detected based on a pulse signal output from the encoder sensor E0004 as the carriage M4000 moves. The output signal is output to the main board E0014 through the CRFFC E0012. An optical sensor and a thermistor for detecting the ambient temperature are connected to the carriage substrate E0013 (hereinafter, these sensors are referred to as a multi-sensor E3000). Information obtained by the multi-sensor E3000 is output to the main board E0014 through the CRFFC E0012.

  The main substrate E0014 is a printed circuit board unit that controls driving of each part of the ink jet recording apparatus according to the present embodiment, and has a host interface (host I / F) E0017 on the substrate. Then, the recording operation is controlled based on data received from a host computer (not shown). The main board E0014 controls driving of a carriage motor E0001 as a driving source for main-scanning the carriage M4000 and an LF motor E0002 as a driving source for transporting the recording medium. Furthermore, the drive of each function is controlled by being connected to various motors such as the AP motor E3005 serving as a drive source for the recovery operation of the recording head H1001 and the recording medium feeding operation, and the PR motor E3006 serving as a drive source for the flat path recording operation. is doing.

  The main board E0014 is a sensor signal for transmitting and receiving control signals and detection signals to various sensors that detect the operation state of each part of the printer, such as a PE sensor, CR lift sensor, LF encoder sensor, and PG sensor. Connected to line E0104. The main board E0014 is connected to each of the CRFFC E0012 and the power supply unit E0015, and further has an interface for exchanging information with the front panel E0106 via a panel signal E0107.

  The front panel E0106 is a unit provided on the front surface of the recording apparatus main body for the convenience of user operation, and includes a resume key E0019, an LED E0020, a power key E0018, and a flat pass key E3004. Furthermore, it has a device I / F E0100 used for connection with peripheral devices such as a digital camera.

Recording Head Configuration The head cartridge in this embodiment has means for mounting the recording head H1001 and the ink tank H1900 and means for supplying ink from the ink tank H1900 to the recording head, and is detachable from the carriage M4000. Installed.

  FIG. 4 is a diagram showing a state in which the ink tank H1900 is attached to the head cartridge applied in the present embodiment. The recording apparatus of the present embodiment forms an image with 10 color inks of C, Lc, M, Lm, Y, K1, K2, R, G, and Gray, and therefore the ink tank H1900 is also independently for 10 colors. It is prepared. As shown in the figure, each ink tank is detachable from the head cartridge. The ink tank H1900 can be attached and detached while the head cartridge is mounted on the carriage M4000.

(First embodiment)
FIG. 5 is a schematic diagram of the recording head and ink discharge ports of the printer of this embodiment. Ink discharge portions 1 to 5 and 6 to 10 are arranged on the two recording element plates A and B, respectively. The recording element plate A is the forward direction end side shown in FIG. 6, and the recording element plate B is the backward direction end side. Of the 10 types of inks corresponding to these ink ejection portions, ink A is an ink containing a color material that is less soluble than other inks, and it is difficult to re-disperse even when mixed with other inks. The nine inks of other inks B to J are very easy to deposit, and the solubility is not particularly low.

  Since the ink A has low solubility, the preliminary discharge is performed in the cap in order to avoid accumulation. On the other hand, since accumulation of other ink does not occur, preliminary ejection can be performed both in the cap and in the ink receiving portion. In order to shorten the scanning distance of the recording head by the preliminary discharging operation to the cap, the ejection port position of the ink A is arranged at the ejection port 10 which is the backward end in the recording element plate B.

  FIG. 6 schematically shows a preliminary flow discharge operation in a printer using the recording head of FIG. In the figure, the recording head is a side view to show the ejection state by the recording head, and the ink receiving portion and the cap portion are plan views to show a state where the ejected ink has landed.

  First, the carriage records an image on the recording medium while scanning in the backward direction, and then moves further in the backward direction (see FIG. 6A).

  Then, the ink A is preliminarily ejected into the cap A at a position where the ejection port 10 for the ink A of the recording head reaches near the cap. The landing position of this preliminary discharge is set to a position close to the forward end in the cap A (see FIG. 6B).

  Thereafter, the carriage moves in the forward direction, and ink is preliminarily discharged to the ink receiving portion at a position where the ink discharge port 1 of the recording head reaches near the ink receiving portion (see FIG. 6C).

  Further, ink is preliminarily discharged to the ink receiving portion at a position where the ink discharge port 2 of the recording head reaches near the ink receiving portion, and the ink corresponding to the other ink discharging ports 3 to 9 is similarly preliminarily discharged into the ink receiving portion. (See FIG. 6D).

  Through the above preliminary ejection operation, the ink A arranged in the recording element plate B is preliminarily ejected at a position near the forward end in the cap A, and the other inks are preliminarily ejected to the ink receiving portion. By disposing the ink A in the ejection port 10 at the backward end of the recording element plate B and making the landing position in the cap A close to the forward end, the distance for scanning the recording head to the cap can be shortened. it can.

  In this embodiment, the distance between the ejection port 1 and the ejection port 10 is about 23 mm, and the scanning distance is 23 mm different between the case where the ink A is arranged in the ejection unit 10 and the case where the ink A is arranged in the ejection unit 1. Will come out. If the scanning speed of the carriage is about 15 inches / sec, a difference of about 0.06 seconds per scanning is obtained. As the number of scans required for image formation increases, the difference per scan affects the throughput. In this embodiment, since there is image recording that requires about 700 scans, it can be seen that performing this Embodiment 1 causes a difference in throughput of about 42 seconds.

  In the present embodiment, an example of a printer having two recording element plates has been described. However, the present embodiment can be applied to a single recording element plate or two or more recording element plates (FIGS. 7A and 7B). . In addition, the cap for performing preliminary discharge is not limited to the cap positioned closest to the forward direction, and preliminary discharge may be performed in a region closer to the forward end than the center in any cap (FIG. 8 ( a), (b)). This is applicable when it is desired to avoid mixing ink existing in the cap.

  In addition, the preliminary ejection timing to the ink receiving portion is shown in FIG. 6D, but may be performed before FIG. 6B.

  Further, the preliminary ejection position of the ink that does not cause the problem of accumulation is not limited to the ink receiving portion in the figure, and may be another forward end of the printer main body, another ink receiving portion provided at the platen portion, or the like.

(Second Embodiment)
The ink discharge port to be set for each ink is designed in consideration of various image formation reasons such as ink physical properties, recording head characteristics, discharge reliability, and so on. In some cases, it cannot always be arranged at the most outlet side outlet. As shown in FIG. 9, an embodiment in the case where the position of the ejection port for ink A is the relative ejection side 2 is shown below.

  First, the carriage records an image on the recording medium while scanning in the backward direction, and then moves further in the backward direction (see FIG. 9A).

  Then, the ink discharge port 10 of the recording head reaches near the cap A. Further, the carriage moves in the backward direction, and the ink A is preliminarily ejected into the cap A at a position where the ejection opening 9 of the ink A reaches the vicinity of the cap A. The landing position of this preliminary discharge is set to a position close to the forward end in the cap A (see FIG. 9B).

  Thereafter, the carriage moves in the forward direction, and ink is preliminarily ejected into the cap A at a position where the ink ejection port 10 of the recording head reaches the vicinity of the cap A. The landing position of this preliminary discharge is set to a position close to or overlapping with the landing position of the ink A in (b) (see FIG. 9C).

  Thereafter, the carriage moves in the forward direction, and ink is preliminarily discharged to the ink receiving portion at a position where the ink discharge port 1 of the recording head reaches the vicinity of the ink receiving portion (see FIG. 9D).

  Further, ink corresponding to the ink discharge ports 2 to 8 is sequentially preliminarily discharged to the ink receiving portion at a position where the ink discharge ports 2 to 8 of the recording head reach the vicinity of the ink receiving portion.

  In this case, the preliminary ejection of ink from the ink ejection port 10 may be performed not on the cap A but on the ink receiving portion, and the scanning distance of the carriage does not change regardless of which is performed.

  Also in this embodiment, the position of the discharge port of the ink A is arranged at a position relatively close to the backward direction end, and the preliminary discharge position in the cap A is set to a position close to the forward direction end, so that the recording head can be moved to the cap. The scanning distance can be shortened.

  The discharge port position of the ink A may be the discharge port 7 or 8, and when there are a plurality of inks with low solubility, these inks are discharged to any one of the discharge ports 8 to 10, that is, the relative backward end. You may assign to the discharge part of the position near. In this embodiment, the preliminary ejection timing to the ink receiving portion is shown in FIG. 9D, but it may be performed before FIG. 9B.

  Further, the preliminary ejection position of the ink that does not cause the problem of accumulation is not limited to the ink receiving portion in the figure, and may be another forward end of the printer main body, another ink receiving portion provided at the platen portion, or the like.

  In this embodiment, an example of a printer having two recording element plates has been described. However, the present embodiment can be applied to a single recording element plate or two or more recording element plates. Further, the cap for performing preliminary discharge is not limited to the cap positioned at the most forward direction end, and preliminary discharge may be performed in a region closer to the forward direction end than the center in an arbitrary cap.

(Third embodiment)
As described above, the position of the ink discharge port is designed in consideration of various image forming reasons such as ink physical properties, recording head characteristics, and discharge reliability. In some cases, the recording element plate B cannot be arranged in the recording element plate B on the side, and must be arranged on the recording element plate A. An embodiment in which the position of the discharge port of the ink A is arranged in the discharge port 5 closest to the backward end in the recording element plate A as shown in FIG. 10 will be described below.

  First, the carriage records an image on the recording medium while scanning in the backward direction, and then moves further in the backward direction (see FIG. 10A).

  Then, the ink discharge port 10 of the recording head reaches near the cap A. Further, the carriage moves in the backward direction, and ink A is preliminarily ejected into the cap A at a position where the ink ejection port 5 reaches the vicinity of the cap A. The landing position of this preliminary discharge is set to a position close to the forward end in the cap A (see FIG. 10B).

  Thereafter, the carriage moves in the forward direction, and ink is preliminarily discharged to the ink receiving portion at a position where the ink discharge port 1 of the recording head has reached the vicinity of the ink receiving portion.

  Further, ink corresponding to the ink discharge ports 2 to 4 and 6 to 10 is sequentially preliminarily discharged to the ink receiving portion at a position where the ink discharge ports 2 to 4 and 6 to 10 of the recording head have reached the vicinity of the ink receiving portion (see FIG. 10 (c)).

  Since the ink discharge ports 6 to 10 are in the vicinity of the cap A or B in (b), preliminary discharge may be performed in the cap in this process, and the scanning distance of the carriage does not change regardless of which is performed.

  The discharge port position of the ink A may be either the discharge port 3 or 4, and when there are a plurality of inks having low solubility, these inks are discharged from any of the discharge ports 3 to 5, or the discharge ports. You may arrange | position in either of 3-5 and either of the discharge outlets 6-10. The latter is an embodiment in which a plurality of inks with low solubility exist and cannot be arranged in the same recording element plate (see FIG. 13).

  In this embodiment, the preliminary ejection timing to the ink receiving portion is shown in FIG. 10C, but may be performed before FIG. 10B.

  Further, the preliminary ejection position of the ink that does not cause the problem of accumulation is not limited to the ink receiving portion in the figure, and may be another forward end of the printer main body, another ink receiving portion provided at the platen portion, or the like.

  In this embodiment, an example of a printer having two recording element plates has been described. However, the present embodiment can be applied to two or more printers (FIGS. 11A and 11B). Further, the cap for performing preliminary discharge is not limited to the cap positioned at the most forward direction end, and preliminary discharge may be performed in a region closer to the forward direction end than the center in an arbitrary cap (FIG. 12). .

  FIG. 13 shows an embodiment in which three recording element plates are provided and inks A and B having low solubility are arranged on separate recording element plates.

  First, the carriage records an image on a recording medium while scanning in the backward direction, and then moves further in the backward direction (see FIG. 13A).

  Then, ink A is preliminarily ejected into the cap A and ink B is preliminarily ejected into the cap B at a position where the ink ejection port 11 of the recording head reaches near the cap B and the ink ejection port 7 reaches near the cap A. . The landing position of this preliminary discharge is set to a position close to the forward end in the cap (see FIG. 13B).

  Thereafter, the carriage moves in the forward direction, and ink is preliminarily discharged to the ink receiving portion at a position where the ink discharge port 1 of the recording head has reached the vicinity of the ink receiving portion.

  Further, ink corresponding to each ejection port is preliminarily ejected sequentially to the ink receiving portion at a position where the ink ejection ports 2 to 6, 8 to 10 and 12 of the recording head reach the vicinity of the ink receiving portion (FIG. 13C). reference).

  In this embodiment, the following combinations of preliminary ejection positions are conceivable, and the preliminary ejection positions are determined in consideration of design restrictions in consideration of ink mixing and the like and how much the scanning distance can be shortened. .

  (Preliminary ejection position of ink A, preliminary ejection position of ink B) = (Cap A, Cap A), (Cap A, Cap B), (Cap A, Cap C), (Cap B, Cap A), (Cap B, cap B), (cap B, cap C)

H1001 Recording head J0013 Recording device M4000 Carriage M5010 Cap M5011 Cap absorber

Claims (7)

An inkjet recording apparatus that records an image by ejecting ink onto a recording medium using a single or a plurality of recording heads in which a plurality of ink ejection openings are arranged in the scanning direction,
Discharge means for pre-discharging the ink from the recording head separately from image recording;
Capping means capable of sealing the ink discharge port forming surface of the recording head with a single or a plurality of caps;
Among the inks, a single or a plurality of inks having relatively low solubility are arranged at the ink discharge ports at a position relatively close to the cap in the scanning direction,
In the case where the single or plural inks having low solubility are preliminarily ejected during a recording operation, the pre-ejection is performed on the in-cap region that is relatively close to the image forming region in the scanning direction
An ink jet recording apparatus. An ink discharge port of the ink having the lowest solubility among the relatively low-solubility single or plural inks is disposed at a position closest to the cap in the scanning direction,
During the recording operation, the ink having the lowest solubility is preliminarily ejected to the area in the cap near the image forming area relative to the scanning direction,
The ink other than the least soluble ink is preliminarily ejected to an ink receiving portion region different from the region in the cap;
The ink jet recording apparatus according to claim 1. The relatively low-solubility single or plural ink discharge ports are disposed at a position relatively close to the cap in the scanning direction;
During the recording operation, the relatively low-solubility single or plural inks and the ink disposed in the ink ejection port closer to the cap than the ink in the scanning direction are moved in the scanning direction. On the other hand, preliminary ejection is performed in the cap area relatively close to the image forming area,
Ink other than the pre-discharged ink is pre-discharged to an ink receiving portion area different from the cap area;
The ink jet recording apparatus according to claim 2. The relatively low-solubility single or plural ink discharge ports are disposed at a position relatively close to the cap in the scanning direction;
During the recording operation, the relatively low-solubility single or plural inks, the ink disposed in the ink ejection port closer to the cap with respect to the scanning direction than the ink, and the scanning direction The ink, which is relatively low in solubility, disposed in the ink ejection port at a position relatively close to the cap, is preliminarily ejected in the cap inner area that is relatively close to the image forming area in the scanning direction. And
Ink other than the pre-discharged ink is pre-discharged to an ink receiving portion area different from the cap area;
The ink jet recording apparatus according to claim 3. The ink discharge port at a position relatively close to the cap is:
1. In a recording head having a single or multiple recording element plate configuration, an ink ejection port arranged in a position closer to the cap than the center in the recording element plate in an arbitrary recording element plate,
2. In a recording head having a plurality of recording element plates, ink discharge ports arranged in the recording element plate at a position closer to the cap than the average among the recording element plates;
3. Both 1 and 2,
The ink jet recording apparatus according to claim 1, wherein the ink jet recording apparatus is an ink jet recording apparatus. The in-cap region that is relatively close to the image forming region with respect to the scanning direction is
1. Of the plurality of cap configurations, an area in the cap that is closer to the image forming area than the average in the cap,
2. 2. An area closer to the image forming area than the center in any cap among single or multiple cap configurations. Both 1 and 2,
The ink jet recording apparatus according to claim 1, wherein the ink jet recording apparatus is an ink jet recording apparatus.   The low-solubility single or multiple inks are imaged relative to the scanning direction regardless of whether the cap in the area where preliminary ejection is performed can seal the ink ejection port. 7. The ink jet recording apparatus according to claim 1, wherein preliminary ejection is performed in an area in a cap close to a formation area or in a cap on the side relatively close to the image formation area.

Images