Patent Description:
A known inkjet recording apparatus records images by ejecting ink onto desired positions of a recording medium. When ejected ink adheres to the nozzle surface of the inkjet head, the ink remaining on the nozzle surface may thicken and solidify while blocking part of ink outlets of nozzles. This may cause poor ink ejection.

To remove ink remaining on the nozzle surface, a known head maintenance apparatus rubs the nozzle surface by relatively sliding a cloth and the nozzle surface on each other at a predetermined speed (for example, see <CIT>). Such a head maintenance apparatus can remove the ink remaining on the nozzle surface. The documents <CIT> and <CIT> disclose further examples of the prior art.

According to the invention of <CIT>, the apparatus removes the remaining ink by uniformly rubbing the nozzle surface. The apparatus may therefore unnecessarily damage the water-repellent film formed on the nozzle surface, depending on the state of ink remaining on the nozzle surface. This may decrease the water-repellent property of the nozzle surface.

The present invention has been conceived in view of the above issue. Objects of the present invention include providing a head cleaning apparatus, an inkjet recording apparatus, a head cleaning method, and a program that can appropriately remove ink remaining on the nozzle surface.

To achieve at least one of the abovementioned objects, a head cleaning apparatus according to claim <NUM> as well as a head cleaning method and a computer program according to the other independent claims of the appended set of claims is provided. Preferred embodiments are described in the dependent claims. Disclosed is a head cleaning apparatus including: a cleaning unit that includes a cleaning member; and a determination unit, wherein the head cleaning apparatus is configured to perform a cleaning operation of cleaning a nozzle surface of an inkjet head with the cleaning member, the nozzle surface having a water-repellent film, wherein the cleaning operation is performed either in a rub mode or a stamp mode, wherein in the rub mode, the cleaning member and the nozzle surface are brought into contact and relatively slid on each other, wherein in the stamp mode, the cleaning member and the nozzle surface are brought into contact and kept still, wherein the determination unit determines which mode is performed, the rub mode or the stamp mode, in the cleaning operation based on a predetermined condition.

Also disclosed is a head cleaning method for a head cleaning apparatus that includes a cleaning unit including a cleaning member and that is configured to perform a cleaning operation of cleaning a nozzle surface of an inkjet head with the cleaning member, the nozzle surface having a water-repellent film, wherein the cleaning operation is performed either in a rub mode or a stamp mode, wherein in the rub mode, the cleaning member and the nozzle surface are brought into contact and relatively slid on each other, wherein in the stamp mode, the cleaning member and the nozzle surface are brought into contact and kept still, wherein the head cleaning method includes determining which mode is performed, the rub mode or the stamp mode, in the cleaning operation based on a predetermined condition.

Also disclosed is a program for a computer of a head cleaning apparatus that includes a cleaning unit including a cleaning member and that is configured to perform a cleaning operation of cleaning a nozzle surface of an inkjet head with the cleaning member, the nozzle surface having a water-repellent film, wherein the cleaning operation is performed either in a rub mode or a stamp mode, wherein in the rub mode, the cleaning member and the nozzle surface are brought into contact and relatively slid on each other, and wherein in the stamp mode, the cleaning member and the nozzle surface are brought into contact and kept still, wherein the program causes the computer to determine which mode is performed, the rub mode or the stamp mode, in the cleaning operation based on a predetermined condition.

The advantages and features provided by one or more embodiments of the invention will become more fully understood from the detailed description given hereinbelow and the appended drawings which are given by way of illustration only, wherein:.

Hereinafter, a preferred embodiment of the present invention is described with reference to the drawings. However, the scope of the invention is not limited to the illustrated examples. In the following description, components having the same function and configuration are marked with the same reference numeral, and the description thereof is omitted.

In the following description, the direction in which a cleaning member <NUM> of a cleaning unit <NUM> is conveyed is the X direction, the direction orthogonal to the X direction on the conveyance surface of the cleaning member <NUM> is the Y direction, and the direction that is orthogonal to the X and Y directions and in which ink is ejected by an inkjet head <NUM> is the Z direction, as shown in the figures.

As shown in <FIG>, an inkjet recording apparatus <NUM> includes an inkjet head <NUM> and a head cleaning apparatus <NUM>.

The inkjet head <NUM> ejects ink from nozzles to print letters or form images on recording media, such as paper or fabric. The nozzles of the inkjet head <NUM> have openings that are arranged in the Y direction on the nozzle surface 11a of the nozzle plate <NUM>.

The nozzle surface 11a is coated with a water-repellent film (ink-repellent film). As the water-repellent film, an organic film made of fluororesin may be mainly used. By coating the nozzle surface 11a with the water-repellent film, the ink is less adhesive to the nozzle surface 11a.

The head cleaning apparatus <NUM> includes a cleaning unit <NUM> that has a cleaning member <NUM> for cleaning (wiping) the nozzle surface 11a. The head cleaning apparatus <NUM> holds the cleaning surface 211a of the cleaning member <NUM> such that the cleaning surface 211a is parallel with the X-Y plane that is parallel with the nozzle surface.

In this embodiment, the cleaning member <NUM> is a long material rolled into a roll. For example, the cleaning member <NUM> may be woven/nonwoven fabric or paper. The cleaning member <NUM> is unwound by the unwinding roller <NUM> and stretched between the supporting rollers <NUM>, <NUM>, thereby forming a cleaning surface 211a at a predetermined position. After cleaning the nozzle surface 11a, the cleaning surface 211a to which ink adheres is wound up by the winding roller <NUM>. At the back surface of the cleaning surface 211a, a backup member <NUM> is disposed. The backup member <NUM> consists of rubber or sponge, for example, to stand against the pushing force of the nozzle surface 11a to the cleaning surface 211a.

<FIG> shows a block diagram showing main functional components of the inkjet recording apparatus <NUM>.

The inkjet recording apparatus <NUM> includes a controller <NUM> (hardware processor, determination unit), an inkjet head driver <NUM>, a cleaning unit driver <NUM>, a carriage driver <NUM>, and a recording medium conveyor <NUM>, as shown in <FIG>. The controller <NUM> sends signals to the respective drivers to control their driving.

The controller <NUM> is a processor that centrally controls the overall operation of the inkjet recording apparatus <NUM>. The controller <NUM> includes a central processing unit (CPU) <NUM>, a random access memory (RAM) <NUM>, a read only memory (ROM) <NUM>, and a storage <NUM>.

The CPU <NUM> reads out control programs and setting data stored in the ROM <NUM> or the storage <NUM>, causes the RAM <NUM> to store the read-out programs and data, and executes the programs to drive and control the inkjet recording apparatus <NUM> and to perform various arithmetic processes.

The RAM <NUM> provides the CPU <NUM>, which performs various control operations, with a working memory space and stores temporary data. The RAM <NUM> may include a non-volatile memory.

The ROM <NUM> stores various control programs to be executed by the CPU <NUM>, setting data, and so forth. Instead of the ROM <NUM>, a rewritable nonvolatile memory (e.g. flash memory) may be used.

The storage <NUM> consists of a hard disk drive (HDD). Along with the HDD, a dynamic random access memory (DRAM) may also be used. The storage <NUM> stores programs to be executed by the CPU <NUM>, print jobs (image recording instructions), image data of images to be recorded in accordance with the print jobs, an operating system (OS), and various kinds of print data related to determination conditions to be described later.

In accordance with the control signals sent from the controller <NUM>, the inkjet head driver <NUM> sends driving signals to the inkjet head <NUM> so that the nozzles appropriately eject ink.

In accordance with the control signals sent from the controller <NUM>, the cleaning unit driver <NUM> outputs driving signals to a motor or a brake of a moving mechanism that moves the cleaning unit <NUM> so that the cleaning unit <NUM> is moved to a position facing the inkjet head <NUM>, which is the target of the cleaning operation.

In accordance with the control signals sent from the controller <NUM>, the carriage driver <NUM> outputs driving signals to a motor or a brake of a moving mechanism that moves the inkjet head <NUM> so that the inkjet head <NUM> is moved to a position facing the recording medium or to a position facing the cleaning unit <NUM>.

In accordance with the control signals sent from the controller <NUM>, the recording medium conveyor <NUM> conveys the recording medium to the conveyance path that faces the inkjet head <NUM>.

The inkjet head <NUM> mounted on the carriage is movable in the Y direction. The controller <NUM> controls the inkjet head driver <NUM>, the carriage driver <NUM>, and the recording medium conveyor <NUM> to perform the recording operation on the recording medium.

On the other hand, when the cleaning operation is performed on the nozzle surface 11a, the controller <NUM> stops the recording operation. The controller <NUM> controls the carriage driver <NUM> and the cleaning unit driver <NUM> to dispose the inkjet head <NUM> at the cleaning position, as shown in <FIG>, and to bring the nozzle surface 11a and the cleaning surface 211a into contact. The contact between the nozzle surface 11a and the cleaning surface 211a is achieved by the lifting-lowering function of the carriage by the carriage driver <NUM> or by the lifting-lowering function of the cleaning unit <NUM> by the cleaning unit driver <NUM>.

The cleaning unit <NUM> of the inkjet recording apparatus <NUM> performs the cleaning operation on the nozzle surface 11a in a rub mode or a stamp mode. Hereinafter, these modes are described.

In <FIG>, <FIG>, <FIG> and <FIG>, the inkjet head <NUM> and the cleaning unit <NUM> are controlled to abut each other or separate from each other by lifting/lowering the cleaning unit <NUM>. However, the abutting and separating may be achieved by lifting/lowering the carriage, as described above.

The rub mode is a mode in which the nozzle surface 11a and the cleaning surface 211a are brought into contact and relatively slid on each other.

Specifically, as shown in <FIG>, in a state where the inkjet head <NUM> and the cleaning unit <NUM> are separate from each other, the controller <NUM> controls the carriage driver <NUM> or the cleaning unit driver <NUM> to bring the nozzle surface 11a and the cleaning surface 211a into contact, as shown in <FIG> and to perform the sliding motion. In the sliding motion, the inkjet head <NUM> or the cleaning unit <NUM> is reciprocated in the Y direction. By the sliding, the ink adhering to the nozzle surface 11a is removed. After the sliding motion, the controller <NUM> separates the nozzle surface 11a and the cleaning surface 211a as shown in <FIG>. The controller <NUM> then drives the unwinding roller <NUM> and the winding roller <NUM> as shown in <FIG> to wind up the ink-adhered cleaning surface 211a and set a new cleaning surface 211b.

By the rub mode, a thickened or further solidified ink that has adhered to the nozzle surface 11a for a certain period of time may be removed. Further, when the cleaning member <NUM> is a woven fabric, the cleaning member <NUM> can remove small ink droplets present in small spaces between warps and wefts.

On the other hand, the sliding motion may damage (scratch) the water-repellent film of the nozzle surface 11a and decrease the water-repellent property of the film.

The stamp mode is a mode where the nozzle surface 11a and the cleaning surface 211a are kept still while being in contact with each other. The stamp mode is different from the rub mode in that, after the controller <NUM> brings the nozzle surface 11a and the cleaning surface 211a into contact as shown in <FIG>, the controller <NUM> does not perform the sliding motion in the Y direction but keeps the nozzle surface 11a and the cleaning surface 211a still, and then separates the nozzle surface 11a and the cleaning surface 211a as shown in <FIG>.

Unlike the rub mode, the stamp mode does not relatively slide the nozzle surface 11a and the cleaning member <NUM> on each other. Therefore, a thickened or further solidified ink may not be sufficiently removed as compared with the rub mode. When the cleaning member <NUM> is a woven fabric, small ink droplets present in small spaces between warps and wefts may not be fully removed.

On the other hand, since the stamp mode does not perform the sliding motion, the stamp mode does not damage the water-repellent film that covers the nozzle surface 11a in removing the remaining ink as compared with the rub mode. When a large amount of ink adheres to the nozzle surface 11a and the rub mode is performed for removing the ink, the ink may return into the nozzles. The stamp mode, on the other hand, can appropriately remove the ink.

Therefore, it is preferable that the cleaning operation be performed in the rub mode when small ink droplets or thickened ink adhere to the nozzle surface 11a, for example.

On the other hand, it is preferable that the cleaning operation be performed in the stamp mode when large ink droplets or ink having a relatively low viscosity adhere to the nozzle surface 11a, for example.

In the inkjet recording apparatus <NUM> of this embodiment, the controller <NUM> functions as a determination unit that determines which mode is performed, the rub mode or the stamp mode, in the cleaning operation, on the basis of the determination condition(s) as described below. The head cleaning apparatus <NUM> therefore can appropriately remove the ink adhering to the nozzle surface 11a.

An example of the determination condition is the time elapsed since the time at which the last cleaning operation is performed, which is not specified in claim <NUM> and the other independent claims of the appended set of claims.

<FIG> is a graph showing the relation between the time elapsed since ink adhered to the nozzle surface 11a and the viscosity of the adhering ink. As shown in <FIG>, the viscosity of ink adhering to the nozzle surface 11a increases as time elapses. This is because discharge products adhere to the ink and the ink becomes dry as time elapses.

Therefore, if the time elapsed since the time at which the last cleaning operation is performed is three hours or longer, the controller <NUM> as the determination unit determines to perform the cleaning operation in the rub mode. If the elapsed time is shorter than three hours, the controller <NUM> determines to perform the cleaning operation in the stamp mode. Thus, the ink adhering to the nozzle surface 11a can be appropriately removed.

The determination condition may be related to the components of ink ejected from the nozzles, which is not specified in claim <NUM> and the other independent claims of the appended set of claims.

For example, the average diameter of titanium oxide (TiO<NUM>) as a pigment of white ink is <NUM> to <NUM> nanometers and is greater than the average diameter of pigments of YMCK inks that is <NUM> to <NUM> nanometers. Further, carbon black (CB) as a pigment of black ink is harder than the pigments of YMCK inks. When the ink containing such pigments adheres to the nozzle surface 11a, the rub mode is likely to damage the water-repellent film covering the nozzle surface 11a.

Therefore, when the ink ejected from the nozzle surface 11a contains titanium oxide or carbon black, for example, the controller <NUM> as the determination unit determines to perform the cleaning operation in the stamp mode. On the other hand, when the ink does not contain titanium oxide or carbon black, the controller <NUM> determines to perform the cleaning operation in the rub mode. Thus, the ink adhering to the nozzle surface 11a can be appropriately removed.

The determination condition may be related to whether the cleaning operation is performed within a predetermined period of time since purging, which is not specified in claim <NUM> and the other independent claims of the appended set of claims. Although the predetermined period of time may be determined as desired, it is preferable the predetermined period of time be short (right after purging).

Right after purging, a large amount of ink adheres to the nozzle surface 11a. When the rub mode is performed on such a nozzle surface 11a, the water-repellent film that covers the nozzle surface 11a may be damaged.

Therefore, if the cleaning operation is performed within a predetermined period of time since purging, the controller <NUM> as the determination unit determines to perform the cleaning operation in the stamp mode. If the cleaning operation is performed after the predetermined period of time since purging, the controller <NUM> determines to perform the cleaning operation in the rub mode. Thus, the ink adhering to the nozzle surface 11a can be appropriately removed.

The determination condition may be related to a statistic(s) of the coverage of the recording operation after the last cleaning operation, which is not specified in claim <NUM> and the other independent claims of the appended set of claims.

Specifically, assume two cases in which the total printing time of the recording operation after the last cleaning operation is the same but the average coverage is greater in one case than in the other case. In the case having the greater average coverage, a more amount of ink adheres to the nozzle surface 11a. Therefore, for a greater coverage, the stamp mode is performed for removing ink so as not to damage the nozzle surface 11a, as shown in the Table I and Table II.

That is, when the average coverage of the recording operation after the last cleaning operation is <NUM>% or greater, the controller <NUM> as the determination unit determines to perform the cleaning operation in the stamp mode. On the other hand, when the average coverage is less than <NUM>%, the controller <NUM> determines to perform the cleaning operation in the rub mode. Thus, the ink adhering to the nozzle surface 11a can be appropriately removed.

The statistic of the coverage of the recording operation after the last cleaning operation, which is referred to by the controller <NUM>, is not limited to the average but may be the mode, the median, or any known statistic.

The determination condition may be related to the total printing time of the recording operation since the last cleaning operation, which is not specified in claim <NUM> and the other independent claims of the appended set of claims.

Specifically, assume two cases where the statistic of the coverage of the printing operation after the cleaning operation is the same but the total printing time is longer in one case than in the other case. In the case having the longer total printing time, a more amount of ink adheres to the nozzle surface 11a. Therefore, for a longer total printing time, the ink is removed by the stamp mode so as not to damage the nozzle surface 11a, as shown in the Table I and Table II.

For example, when the total printing time of the recording operation since the last cleaning operation is five hours or longer, the controller <NUM> as the determination unit determines to perform the cleaning operation in the stamp mode. When the total printing time is shorter than five hours, the controller <NUM> determines to perform the cleaning operation in the rub mode. Thus, the ink adhering to the nozzle surface 11a can be appropriately removed.

The determination condition may be related to the period of time during which the inkjet head <NUM> is mounted, which is not specified in claim <NUM> and the other independent claims of the appended set of claims.

<FIG> is a graph showing the relation between the period of time during which the inkjet head <NUM> is mounted and the water-repellent property of the nozzle surface 11a. As shown in <FIG>, the longer the inkjet head <NUM> is mounted, the lower the water-repellent property of the nozzle surface 11a becomes. Therefore, the ink is more difficult to remove by the stamp mode when the inkjet head <NUM> has been mounted for a long time, even if the ink adheres to the nozzle surface 11a in the normal way. This is because the longer the inkjet head <NUM> is mounted, the more number of times of cleaning operation is performed in the rub mode and the water-repellent film receives more damage.

Therefore, for example, when the number of days elapsed since the date on which the inkjet head <NUM> is mounted is seven months or more, the controller <NUM> as the determination unit determines to perform the cleaning operation in the rub mode. When the number of days elapsed is less than seven months, the controller <NUM> determines to perform the cleaning operation in the stamp mode. Thus, the ink adhering to the nozzle surface 11a can be appropriately removed.

The determination condition according to the invention is the installation angle of the inkjet head with respect to the horizontal plane when the inkjet head <NUM> is installed.

Specifically, when the installation angle is steep, the ink adhering to the nozzle surface 11a after ink ejection or purging drops from the nozzle surface 11a toward the top plate by gravity. Accordingly, a less amount of ink remains on the nozzle surface 11a, and the water-repellent film is less likely to be damaged. Therefore, when the installation angle is steep, the ink I s removed by the rub mode.

For example, when the installation angle of the inkjet head <NUM> with respect to a horizontal plane at the time of installation is <NUM> degrees or greater, the controller <NUM> as the determination unit determines to perform the cleaning operation in the rub mode. When the installation angle is less than <NUM> degrees, the controller <NUM> determines to perform the cleaning operation in the stamp mode. Thus, the ink adhering to the nozzle surface 11a can be appropriately removed.

In the above embodiment, the controller <NUM> determines which mode is performed, the rub mode or the stamp mode, in the cleaning operation on the basis of one determination condition. The controller <NUM> may determine the mode on the basis of a combination of determination conditions.

The embodiment, in which the controller <NUM> determines the mode of the cleaning operation on the basis of a combination of conditions in accordance with the determination process, is illustrated with an example of a determination process described on the basis of the flowchart in <FIG> that is merely suitable for understanding this embodiment but not specified in claim <NUM> and the other independent claims.

In response to receiving an instruction to perform the cleaning operation, the controller <NUM> of the inkjet recording apparatus <NUM> resets a determination variable α to zero (Step S101). The determination variable α is for determining which mode is performed in the cleaning operation.

The controller <NUM> determines whether the components of ink ejected from the inkjet head <NUM> (cleaning target) include titanium oxide or carbon black (Step S102).

When determining that neither titanium oxide nor carbon black is included (Step S102: NO), the controller <NUM> adds <NUM> to the determination variable α and proceeds to step S104 (Step S103). When determining that ether titanium oxide or carbon black is included in the ink (Step S102: YES), the controller <NUM> proceeds to step S104.

The controller <NUM> determines whether the period of time during which the inkjet head <NUM> is mounted is seven months or longer (Step S104).

When determining that the period of time during which the inkjet head <NUM> is mounted is seven months or longer (Step S104: YES), the controller <NUM> adds <NUM> to the determination variable α and proceeds to step S106 (Step S105). When determining that the period of time during which the inkjet head <NUM> is mounted is shorter than seven months (Step S104: NO), the controller <NUM> proceeds to step S106.

The controller <NUM> then determines whether the time elapsed since the last cleaning operation is three hours or longer (Step S106).

When determining that the time elapsed since the last cleaning operation is three hours or longer (step S106: YES), the controller <NUM> substitutes <NUM> for the determination variable α and proceeds to step S108 (Step S107). When determining that the time elapsed since the last cleaning operation is shorter than three hours (Step S106: NO), the controller <NUM> proceeds to Step S108.

Lastly, the controller <NUM> determines whether the determination variable α is greater than <NUM> (Step S108). When determining that the determination variable α is greater than <NUM> (Step S108: YES), the controller <NUM> sends a signal to perform the cleaning operation on the inkjet head <NUM> in the rub mode (Step S109). When determining that the determination variable α is <NUM> or less (Step S108: NO), the controller <NUM> sends a signal to perform the cleaning operation on the inkjet head <NUM> in the stamp mode (Step S110).

As described above, in the present invention, the mode of the cleaning operation can be determined on the basis of a combination of determination conditions.

In the above description, the controller <NUM> determines the mode on the basis of the combination of the determination conditions <NUM>, <NUM>, <NUM> as an example. However, the combination of determination conditions from among the determination conditions <NUM> to <NUM> may be determined as desired. The value added to the determination variable α, the value to be substituted, and the value for determination in the respective steps may be increased or decreased as desired on the basis of the number of determination conditions included in the combination of determination conditions or on the basis of the weighting on the respective determination conditions included in the combination.

Next, the evaluation results of preferred configurations in the rub mode of the present invention are described with respect to the contact time and the relative sliding speed between the nozzle surface 11a and the cleaning surface 211a. Described in detail below are examples that do not limit the present invention.

Ink mists were intentionally adhered to the nozzle surfaces 11a of ten inkjet heads <NUM>. Each of the ten inkjet heads <NUM> was then subjected to the following examination.

The result of the examination is shown in Table IV and Table V.

The evaluation results of the cases where the sliding speed was <NUM>/s and the evaluation results of the cases where the sliding speed was <NUM>/s are compared to each other. The comparison shows that, when the sliding speed is the same, the shorter contact time between the nozzle surface 11a and the cleaning surface 211a results in the better ink cleaning capability.

This is because the cleaning surface 211a pulls out ink from the nozzles and stains the nozzle surface 11a when the cleaning member <NUM> is in contact with the nozzle surface 11a for a long time.

On the other hand, when the contact time is too short, the cleaning motion is not sufficiently performed. It is therefore preferable that the cleaning member <NUM> be in contact with the nozzle surface 11a at least for two seconds or longer.

When the sliding speed was <NUM>/s and the contact time was <NUM> seconds, the evaluation result was "AA". On the other hand, when the sliding speed was <NUM>/s and the contact time was <NUM> seconds, the evaluation result was "BB". This shows that, when the contact time is the same, the lower sliding speed between the nozzle surface 11a and the cleaning member <NUM> results in the better ink cleaning capability.

This is because the lower sliding speed allows the cleaning member <NUM> to sufficiently absorb the ink adhered to the nozzle surface 11a.

When the contact time is kept unchanged and the sliding speed is increased, the number of times of sliding increases and the water-repellent film is more likely to be damaged. It is therefore preferable that the sliding speed be slow.

When the cleaning member <NUM> is woven fabric, it is preferable that the yarn constituting the fabric be split yarn having a cross section as shown in <FIG>. As shown in <FIG>, the split yarn consists of a combination of two kinds of fibers S1, S2. The nylon fiber is used as the fiber S1, and the polyester fiber is used as the fiber S2. The split yarn consists of two kinds of fibers S1, S2 made of different materials and is subjected to the process of opening the fibers. As a result, the fibers are split into finer and distorted fibers.

The split yarn having a fine fiber structure enhances the liquid-absorbing capability of the cleaning member <NUM>. The split yarn having distorted fibers also enhances the ink scraping capability of the cleaning surface 211a in the rub mode.

As shown in <FIG>, it is preferable that the cleaning member <NUM> be configured such that the width W2 of the cleaning member <NUM> in the Y direction be wider than the width W1 of the nozzle plate <NUM> having the nozzle surface 11a in the Y direction. According to such a configuration, the motion of the cleaning member <NUM> can be simplified in both the rub and stamp modes. Specifically, in both modes, the nozzle surface 11a and the cleaning surface 211a are firstly brought into contact; in the rub mode, the sliding is performed from the contact position; in the stamp mode, the cleaning surface 211a and the nozzle surface 11a are kept still at the contact position.

Further, as shown in <FIG>, it is preferable that the cleaning member <NUM> be configured such that the width W2 of the cleaning member <NUM> in the Y direction be wider than the total of (i) the width W1 of the nozzle plate <NUM> having the nozzle surface 11a in the Y direction and (ii) the sliding distance T1 in the Y direction in the rub mode. According to such a configuration, the whole nozzle surface 11a is always in contact with the cleaning member <NUM> in the sliding motion in the rub mode. This increases the scraping capability of the cleaning member <NUM>.

When the cleaning member <NUM> is a woven fabric, it is preferable that a dry fabric be used for the cleaning operation. If the cleaning member <NUM> is wet, the adhesion between the nozzle surface 11a and the cleaning member <NUM> is likely to increase. Accordingly, the cleaning member <NUM> may pull out ink from the nozzles and may stain or damage the nozzle surface 11a.

Although the inkjet recording apparatus <NUM> includes the head cleaning apparatus <NUM> in the above description, this is not the limitation. The head cleaning apparatus <NUM> may be separate from the inkjet recording apparatus <NUM>.

In the above description, the ROM <NUM> is used as a computer-readable medium that stores the programs of the present invention. However, the computer readable medium is not limited to this example.

As other computer-readable storage media, a nonvolatile memory, such as a flash memory, and a portable storage medium, such as a CD-ROM, may also be used.

Further, a carrier wave may be used as a medium to provide data of the programs of the present invention via a communication line.

Claim 1:
A head cleaning apparatus (<NUM>) comprising:
a cleaning unit (<NUM>) that includes a cleaning member (<NUM>); and
a determination unit (<NUM>),
wherein the head cleaning apparatus is configured to perform a cleaning operation of cleaning a nozzle surface (11a) of an inkjet head (<NUM>) with the cleaning member, the nozzle surface having a water-repellent film,
wherein the cleaning operation is performed either in a rub mode or a stamp mode, wherein in the rub mode, the cleaning member and the nozzle surface are brought into contact and relatively slid on each other, wherein in the stamp mode, the cleaning member and the nozzle surface are brought into contact and kept still,
wherein the determination unit (<NUM>) is configured to determine which mode is performed, the rub mode or the stamp mode, in the cleaning operation based on a predetermined condition,
characterized in that it is
based on an amount of ink adhered to the nozzle surface (11a), wherein the determination unit (<NUM>) determines the stamp mode in response to that the amount of ink being greater than a predetermined amount, and determines the rub mode in response to that the amount of ink being equal to or less than the predetermined amount, wherein when the inkjet head (<NUM>) is installed with an angle of installation of the inkjet head (<NUM>) with respect to a horizontal plane and the predetermined condition being whether the installation angle of the inkjet head (<NUM>) exceeds a predetermined angle or not, below that angle, there is a condition of having a large amount of ink adhering to the nozzle surface (11a), and above that angle, there is not a condition of having a large amount of ink adhering to the nozzle surface (11a).