JP2005224990A - Discharge defect detection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a discharge defect detection method whereby discharge defects of a transparent ink can be detected simply and correctly. <P>SOLUTION: In the discharge defect detection method for detecting the discharge defects of the transparent ink at the time of carrying out image recording by discharging both a fundamental color ink and the transparent ink from a plurality of recording heads for fundamental color 5 and a recording head for transparent 7 to a recording medium P, an infrared absorbing agent which absorbs infrared rays and colors is mixed into the transparent ink. The transparent ink with the infrared absorbing agent mixed is discharged from the recording head for transparent 7. A striking state of the transparent ink is visually detected by irradiating infrared rays to the transparent ink struck on a surface of the recording medium P. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a discharge failure detection method, and more particularly to a discharge failure detection method for detecting a discharge failure of transparent ink.

  In recent years, an image recording method using an inkjet image recording apparatus has been performed as an image recording method capable of recording an image simply and inexpensively. In an image recording method using an inkjet method, for example, a piezo element or a heater is used to eject ink from a nozzle of a recording head as a fine droplet toward a recording medium such as paper, and the ink penetrates the recording medium. An image is recorded on the recording medium by moving the recording head on the recording medium while fixing.

  In addition, recently, in order to give a glossy image to a recorded image to obtain a high-definition image of photographic quality, and further to protect the image recording surface and obtain a recorded image with excellent scratch resistance, each colored color A technique for ejecting transparent ink in addition to the basic color ink is known.

  However, in an inkjet image recording apparatus, when the recording operation is continuously performed, the ink that is ejected from the nozzles of the recording head and deposited in the vicinity of the nozzles may adhere to and accumulate on the nozzles, causing clogging. is there. When the image recording operation is continued in such a state, even if the nozzle performs an ejection operation by the action of a piezo element or the like, a so-called nozzle lack in which no ink droplet is ejected or an ink droplet is not ejected in the correct direction. A discharge failure such as so-called discharge bending occurs, and high-definition image recording cannot be performed.

  Therefore, in order to always perform high-definition image recording, it is necessary to accurately detect whether or not ejection defects such as missing nozzles or ejection bending have occurred before image recording is performed. By ejecting ink onto a test pattern for confirmation, ejection failure is visually detected.

However, when the ink is transparent, it is not possible to visually confirm the portion where the ink is ejected by simply printing on the test pattern, and it is not possible to detect ejection failure. In this regard, conventionally, it is possible to visually confirm the ejection failure by applying a test liquid that exhibits a color reaction to the transparent ink on the image recording surface of a normal recording medium and then ejecting the transparent ink thereon. A detection method is known (for example, see Patent Document 1).
JP 2003-326828 A

  However, in the case of transparent ink, even if the test liquid is used, it is difficult to visually check the landing state of the ink if it is printed on a normal recording medium like other basic color inks. There is a problem that it is not possible to accurately detect whether the nozzle is a missing nozzle that does not discharge ink or which nozzle has a discharge bend. As described above, when the ejection failure cannot be accurately detected, the image recording operation may be started without being discovered although the ejection failure has occurred. In this case, there is a problem that defective printing occurs such that the transparent ink is not uniformly ejected, high-definition image recording cannot be performed, and the image quality of the recorded image is deteriorated.

  Further, in the case of a method for detecting defective discharge of a transparent ink by applying a test liquid to the image recording surface of a normal recording medium, first, the liquid is first applied to the image recording surface of the normal recording medium before discharging the transparent ink. There is a problem that it is necessary to go through a pretreatment process of applying a test solution, which requires time and effort for detection work.

  Therefore, the present invention has been made to solve the above-described problems, and an object of the present invention is to provide a discharge failure detection method that can detect discharge failure of transparent ink simply and accurately. .

In order to solve such problems, the invention described in claim 1 is directed to ejecting the transparent ink when performing image recording by ejecting basic color ink and transparent ink from a recording head onto a recording medium. In the ejection defect detection method for detecting defects,
The transparent ink is mixed with an infrared absorber that develops color by absorbing infrared rays, the transparent ink mixed with the infrared absorber is ejected from the recording head, and the transparent ink landed on the surface of the recording medium is irradiated with infrared rays. By doing so, the landing state of the transparent ink is visually detected.

  The invention according to claim 1 having such a configuration is transparent by visually observing the landing status of the transparent ink by ejecting the transparent ink mixed with the infrared absorbent onto the recording medium and irradiating the recording medium with infrared rays. It is possible to detect whether there is no ejection failure such as nozzle missing or ejection bending or deviation of the ink landing position in the recording head that ejects ink.

  According to a second aspect of the present invention, in the ejection failure detection method according to the first aspect of the invention, the recording head uses a heating unit to apply ink that is a liquid having a viscosity of 10 to 500 mPa · s at 30 ° C. to 30 to 150. It is characterized by being heated so as to discharge so that one dot becomes a small droplet of 2 to 20 pl.

  The invention according to claim 2 having such a configuration uses a high-viscosity ink having a viscosity of 10 to 500 mPa · s at 30 ° C., so even on a recording medium having no ink absorbability, However, even when such high-viscosity ink is used, it is possible to appropriately detect defective ejection of the transparent ink.

  According to a third aspect of the present invention, in the ejection failure detection method according to the first or second aspect, the ink is a photocurable ink that is cured by irradiating light, and the ink is more than the recording head. A light irradiation device for irradiating light onto the ink landed on the recording medium is provided on the downstream side in the conveyance direction of the recording medium.

  The invention according to claim 3 having such a configuration can appropriately detect defective ejection of transparent ink even when the ink ejected from the recording head is cured by being irradiated with light and fixed on the recording medium. It is like that.

  Further, according to a fourth aspect of the present invention, in the ejection failure detection method according to the third aspect, the ink is an ultraviolet curable ink that is cured by irradiating ultraviolet rays, and is irradiated from the light irradiation device. It is characterized in that at least a part of the light is ultraviolet rays.

  As described above, the invention according to claim 4 can appropriately detect the ejection failure of the transparent ink even when the ink ejected from the recording head is cured by being irradiated with ultraviolet rays and fixed on the recording medium. It has become.

  Next, according to a fifth aspect of the present invention, in the ejection failure detection method according to any one of the first to fourth aspects, the ink is a high-viscosity ink, and is a cationic polymerization ultraviolet curable ink. It is characterized by being.

  Therefore, in the invention described in claim 5, it is possible to appropriately detect the ejection failure of the transparent ink even when the ink has a high viscosity and, in particular, the cationic polymerization type ultraviolet curable ink mainly composed of the monomer is used. It is like that.

  Next, an invention according to claim 6 is the ejection failure detection method according to any one of claims 1 to 5, wherein the recording medium has no ink absorbability.

  Therefore, when an image is recorded on a recording medium such as a resin that does not absorb ink, high-viscosity ink is used to prevent the ink from flowing on the recording medium. According to the invention, even in such a case, it is possible to appropriately detect the defective ejection of the transparent ink.

  According to the first aspect of the present invention, since image recording is performed using transparent ink in addition to basic color ink, high-definition image recording with photographic image quality can be performed, and the image recording surface of the recording medium Can be obtained, and a recorded image having excellent scratch resistance can be obtained. In order to uniformly discharge the transparent ink, it is necessary that the nozzle that discharges the transparent ink does not have a discharge failure. However, in the invention described in claim 1, the transparent ink mixed with the infrared absorbent is used. Ink is ejected onto the recording medium. For this reason, the infrared absorber mixed in the transparent ink is colored by irradiating the spot where the transparent ink has landed with infrared rays, and the landing state of the transparent ink can be visually observed. As a result, it is possible to easily and accurately detect whether or not the recording head that discharges the transparent ink has any ejection defects such as missing nozzles or bending of the discharge, and the recording head that discharges the transparent ink has a high-quality and high-definition image. There is an effect that it can be confirmed whether or not it is in a state suitable for recording.

  In addition, by visually confirming the landing status of the transparent ink that has landed on the recording medium, it is possible to accurately grasp whether or not there is a deviation in the landing position of the transparent ink with respect to the transparent recording head. By irradiating the medium with infrared rays and confirming the landing status of the transparent ink, the recording head position on the carriage and the carriage drive adjustment in the main scanning direction and the conveyance direction can be easily and appropriately performed. .

  According to the second aspect of the present invention, since the high-viscosity ink having a viscosity of 10 to 500 mPa · s at 30 ° C. is used, the ink on the recording medium can be used for a recording medium having no ink absorption. It is possible to perform high-quality image recording without causing flow, etc., and even when using such high-viscosity ink, it is possible to accurately and efficiently detect defective discharge of transparent ink, and discharge transparent ink. There is an effect that it can be confirmed whether or not the recording head is in a state suitable for high-quality and high-definition image recording.

  Further, since the ink is heated to 30 to 150 ° C. and discharged from the recording head, it is possible to perform image recording while maintaining good ink discharge from the nozzle, and further, the ink is 2 to 20 pl per dot. Since the liquid droplets are ejected in small droplets, a high-quality image can be obtained even with high viscosity ink. Even in such a case, it is possible to accurately and efficiently detect defective ejection of the transparent ink, and whether the recording head that ejects the transparent ink is in a state suitable for performing high-quality and high-definition image recording. There is an effect that it is possible to confirm.

  Next, according to the invention described in claim 3, since the ink is cured by irradiating the ink with ultraviolet rays, an image is formed even on a recording medium having poor ink absorbability such as a resin film. However, even in such a case, it is possible to accurately and efficiently detect defective discharge of the transparent ink, and the recording head that discharges the transparent ink is in a state suitable for performing high-quality and high-definition image recording. There is an effect that it can be confirmed whether or not it is.

  According to the invention described in claim 4, since the ink is cured by irradiating the ink with ultraviolet rays, it is possible to form an image even on a recording medium having poor ink absorbability such as a resin film. However, even in such a case, it is possible to accurately and efficiently detect defective ejection of the transparent ink, and whether the recording head that ejects the transparent ink is in a state suitable for performing high-quality and high-definition image recording. There is an effect that it can be confirmed whether or not.

  According to the invention described in claim 5, even when a high-viscosity ink, particularly a cationic ultraviolet curable ink mainly composed of a monomer, is used, defective ejection of the transparent ink accurately and efficiently. It is possible to detect whether or not the recording head that discharges the transparent ink is in a state suitable for performing high-quality and high-definition image recording.

  Furthermore, according to the invention described in claim 6, high-viscosity ink is used in order to prevent ink from flowing on the recording medium even when an image is recorded on a recording medium such as resin that does not absorb ink. However, even in such a case, the defective ejection of the transparent ink can be detected accurately and efficiently, and the recording head that ejects the transparent ink is in a state suitable for performing high-quality and high-definition image recording. There is an effect that it can be confirmed whether or not there is.

  Hereinafter, embodiments of a discharge failure detection method according to the present invention will be described with reference to the accompanying drawings.

  FIG. 1 shows one embodiment of an image recording apparatus to which the ejection failure detection method according to the present invention is applied. As shown in FIG. 1, the image recording apparatus 1 according to the present embodiment is serial. The printing type image recording apparatus 1 includes a platen 2 that is formed in a flat plate shape and supports a recording medium P from a non-recording surface.

  In addition, the image recording apparatus 1 conveys the recording medium P in the conveyance direction of the recording medium P orthogonal to the arrow A direction (hereinafter referred to as “main scanning direction A”) shown in FIG. It is like that.

  A bar-shaped carriage rail 3 is disposed above the platen 2 so as to extend in the main scanning direction A perpendicular to the transport direction. A carriage 4 is supported on the carriage rail 3 so as to reciprocate along the carriage rail 3, and the carriage 4 is reciprocated along the main scanning direction A by a drive source (not shown). Yes. Note that an area where the platen 2 is arranged, which is substantially in the center of the movable range of the carriage 4, is a recording area Y where image recording is performed.

  The carriage 4 includes four basic color recording heads 5 corresponding to the respective colors (black (K), cyan (C), magenta (M), and yellow (Y)) used in the image recording apparatus 1 according to the present embodiment. , 5... Are mounted as a group. A plurality of nozzles 6, 6... Are formed on the surface of each of the basic color recording heads 5, 5... Facing the recording medium P, and each ejects ink. Note that the color of the ink used in the image recording apparatus 1 is not limited to this, and for example, colors such as light yellow (LY), light magenta (LM), and light cyan (LC) can be used. In this case, a recording head corresponding to each color is mounted on the carriage 4.

  Further, on the carriage 4, a transparent recording head 7 for discharging transparent ink (transparent ink (T)) is mounted adjacent to the basic color recording heads 5, 5. A plurality of nozzles 8 are formed on the surface of the transparent recording head 7 facing the recording medium P.

  Further, inside the carriage 4, between the one end side wall of the carriage 4 and the transparent recording head 7, and between the other end side wall of the carriage 4 and the basic color recording heads 5, 5. The ultraviolet irradiation devices 9 and 9 having a length dimension substantially equal to the length of the recording heads 5, 5, 7 are arranged substantially parallel to the longitudinal direction of the recording heads 5, 7. The ultraviolet irradiation devices 9 and 9 are provided with an ultraviolet light source (not shown). As the ultraviolet light source, for example, a high pressure mercury lamp, a low pressure mercury lamp, a metal halide lamp, a semiconductor laser, a cold cathode tube, an excimer lamp, or an LED (Light Emitting Diode) can be applied. The positions where the ultraviolet irradiation devices 9 and 9 are provided are not limited to this, and for example, they may be provided between the recording heads 5, 7.

  An infrared irradiation device 19 that irradiates infrared rays is provided at one end of the carriage 4.

  The outer end of the recording area Y in which the carriage 4 is movable and the platen 2 is provided is a maintenance area Z. The maintenance area Z includes nozzles 6 and 6 of the recording heads 5, 5. ..., a maintenance unit 10 for performing maintenance of 8 is provided. In the maintenance unit 10, suction caps 11, 11... For sucking ink from the nozzles 6, 6. Correspondingly, five are provided.

  On the bottom surface of the suction caps 11, 11,... Are provided with ink communication pipes 12, 12,. In the middle of the ink communication pipes 12, 12..., Suction pumps 13, 13... That are suction devices are provided, and a waste ink tank 14 that receives the sucked ink is provided at the lower ends of the ink communication pipes 12, 12. Is provided.

  Further, near the one end of the suction caps 11, 11..., There is provided an empty discharge tray 15 for receiving ink discharged when ink is discharged from the nozzles 6, 8. A blade 16 is provided adjacent to 15 for wiping off ink remaining in the nozzles 6, 6, 8.

  In addition, a position opposite to the maintenance area Z across the platen 2 at the other end of the movement range of the carriage 4 is a home position area X. In the home position area X, a protection unit 17 is provided. It has been. The protective unit 17 is provided with a number of protective caps 18, 18,... Corresponding to the recording heads 5, 5,..., And the nozzles 6 of the recording heads 5, 5,. , 6... 8 are brought into contact with the protective caps 18, 18... To protect the nozzles 6, 6.

  Next, the transparent ink used in the ejection failure detection method in this embodiment will be described.

  In the present embodiment, the transparent ink is mixed with an infrared absorbent that absorbs infrared rays and develops color, and after the transparent ink is ejected onto the recording medium P, the infrared rays are irradiated to absorb the infrared rays contained in the transparent ink. The agent is colored. For this reason, as shown in FIG. 2, it can be visually confirmed to which part of the recording medium P the transparent ink has landed.

  As a result, it is possible to easily detect and identify a nozzle missing portion or a discharge bending portion where ink is not normally ejected. Further, by confirming the landing position of the ink that has landed on the surface of the recording medium P, the position of the transparent recording head 7 on the carriage 4 is appropriate, or the carriage 4 is driven in the main scanning direction A and the conveying direction appropriately. Can be judged. Thus, when the position of the transparent recording head 7 on the carriage 4 is deviated from the proper position, the position of the transparent recording head 7 is adjusted by a head position adjusting mechanism (not shown). If the carriage 4 is not properly driven in the main scanning direction A and the conveyance direction, the carriage 4 is adjusted so that the carriage 4 is driven properly by adjusting the attachment position and angle of the carriage 4. It has become.

  This infrared absorber preferably has a maximum infrared absorption wavelength of 750 to 1100 nm, more preferably 800 to 1100 nm. Examples of infrared absorbers applicable in this embodiment include those shown in JP-A-2002-99111 and JP-A-2003-76055. Specifically, for example, cyanine compound type, diimonium compound type, aminium compound type, Ni complex compound type, phthalocyanine compound type, anthraquinone compound type, and naphthalocyanine compound type, thiopyrylium squarylium dye, thiopyrylium croconium dye , Pyrylium squarylium dye or pyrylium croconium dye, serenapyrylium squarylium dye, serenapyrylium croconium dye, telluropyrylium squarylium dye, telluropyrylium croconium dye, and the like. In addition, what can be applied as an infrared absorber is not limited to what was illustrated here.

  The addition amount of the infrared absorber to the transparent ink is 0.01% by mass to 3% by mass, preferably 0.01% by mass to 2% by mass, based on the total mass of the transparent ink composition. That is, when the amount of the infrared absorbent added to the transparent ink is less than 0.01% by mass, sufficient color is not generated even when irradiated with infrared rays, and the landing state of the transparent ink is easily and accurately detected visually. Is likely to be difficult. On the other hand, if the addition amount exceeds 3% by mass, not only will it be economically disadvantageous, but the color of the transparent ink may be garbled or the curability of the transparent ink may be adversely affected. This is because Therefore, the detection of whether or not the discharge of the transparent ink is properly performed, for example, using SIR130 (infrared absorbing dye made by Mitsui Chemicals) as an infrared absorber, adding 0.1% of the transparent ink to the transparent ink This is performed by irradiating the recording medium P with transparent ink mixed in an amount and then irradiating the recording medium P with infrared light.

  The ink used in the present embodiment is a photocurable ink having a property of being cured by being irradiated with ultraviolet rays as light, and contains at least a polymerizable compound (including a known polymerizable compound) as a main component. ), A photoinitiator, and a coloring material. The photocurable ink is roughly classified into a radical polymerization ink containing a radical polymerizable compound as a polymerizable compound and a cationic polymerization ink containing a cationic polymerizable compound. Both inks are included in this embodiment. Each can be applied as an ink to be used. Further, a hybrid ink in which radical polymerization ink and cation polymerization ink are combined may be applied as the ink used in this embodiment. However, since cationic polymerization inks that have little or no inhibitory action on polymerization reaction due to oxygen are superior in functionality and versatility, it is particularly preferable to use cationic polymerization inks. The cationic polymerization ink is a mixture containing at least a cationic polymerizable compound such as an oxetane compound, an epoxy compound, and a vinyl ether compound, a photocationic initiator, and a coloring material.

  The recording medium P is made of various materials such as various papers such as plain paper, recycled paper, glossy paper, various fabrics, various non-woven fabrics, etc., and non-ink-absorbing materials such as resin, metal, and glass. The recording medium P is applicable. In addition, as the form of the recording medium P, various forms such as a roll form, a cut sheet form, and a plate form are applicable.

  Next, the operation of this embodiment will be described.

  First, in this embodiment, the carriage 4 on which the recording heads 5, 5,..., 7 are mounted waits on the protection unit 17 disposed in the home position area X at times other than image recording and head maintenance operation. The protective caps 18, 18... Provided on the protection unit 17 cover the surfaces of the recording heads 5, 7. .., 7 nozzles 6, 6, 8 are protected.

  When an image recording operation is performed, the carriage 4 moves to the recording area Y. Further, when the recording medium P is conveyed to a predetermined position on the platen 2, first, only the transparent ink is ejected from the transparent recording head 7. Thereafter, the ultraviolet irradiation devices 9 and 9 and the infrared irradiation device 19 are turned on to irradiate the recording medium P with ultraviolet rays and infrared rays while moving the carriage 4. As a result, the infrared absorber mixed in the transparent ink is cured and fixed on the recording medium P in a colored state. The user takes out the recording medium P on which the transparent ink has landed from the image recording apparatus 1 and visually confirms that there is no ejection abnormality in the nozzle 8 of the transparent recording head 7 and on the carriage 4 of the transparent recording head 7. In the main scanning direction A and the conveyance direction of the carriage 4 is properly determined. If there is no ejection abnormality and no abnormality is found in the position of the transparent recording head 7 and the drive of the carriage 4, the image recording operation is started, and the recording medium P is conveyed in the conveying direction X by the conveying mechanism. When the recording medium P reaches a predetermined position on the platen 2, the carriage 4 reciprocates along the carriage rail 3 and predetermined image data from the basic color recording heads 5, 5... And the transparent recording head 7 nozzle 8. The required ink is ejected based on the above. At the same time, the light sources of the ultraviolet irradiation devices 9 and 9 are turned on, and ultraviolet rays are irradiated to the ink ejected on the recording medium P, whereby the ink is cured and fixed, and an image is formed on the recording surface of the recording medium P. Is recorded.

  Further, when there is a discharge abnormality, the carriage 4 is moved to the maintenance area Z, and the maintenance operation of the nozzles 6, 6,. When the carriage 4 moves to a predetermined position, the maintenance unit 10 rises and the nozzles 6, 6,... 8 of the recording heads 5, 5,. And sealed. In this state, the suction pumps 13, 13,... Are operated to apply a negative pressure to the inside of the suction caps 11, 11,. The ink sucked from the recording heads 5, 5,..., 7 is sent to the waste ink tank 14 through the ink communication pipes 12, 12,. When the suction operation is completed, the maintenance unit 10 is lowered, whereby the suction caps 11, 11,... Are separated from the recording heads 5, 5,. Thereafter, the maintenance unit 10 is moved forward and upward, and the blade 16 is slidably contacted with the nozzles 6, 6,. Thereby, the ink, dust, etc. adhering to the nozzles 6, 6,..., 8 are wiped off. Next, the recording heads 5, 5,..., 7 are moved above the empty discharge tray 15 provided in the maintenance unit 17, and the recording heads 5, 5,. As a result, the maintenance operation of the recording heads 5, 5,..., 7 is completed, and the recording heads 5, 5,.

  Further, when the position of the transparent recording head 7 on the carriage 4 is deviated from an appropriate position, fine adjustment is appropriately performed by a head position adjusting mechanism so as to come to an appropriate position. Furthermore, when the carriage 4 is not properly driven in the main scanning direction A and the conveyance direction, the mounting position and angle of the carriage 4 are adjusted, and the carriage 4 is properly adjusted in the main scanning direction A and the conveyance direction. The image recording operation is started after the adjustment to drive.

  Therefore, according to the present embodiment, since image recording is performed using transparent ink in addition to basic color ink, it is possible to perform high-definition image recording with photographic image quality and protect the image recording surface of the recording medium P. In addition, a recorded image having excellent scratch resistance can be obtained.

  Further, since such transparent ink is transparent, it is difficult to visually check the landing position of the ink even if it is simply ejected onto the surface of the recording medium P. In this embodiment, an infrared absorber is used. The mixed transparent ink is ejected onto the recording medium P. For this reason, the infrared absorber mixed in the transparent ink is colored by irradiating the portion where the transparent ink has landed with infrared rays, and the landing state of the transparent ink can be visually observed. As a result, it is possible to easily and accurately detect whether or not the transparent recording head 7 that discharges the transparent ink has a discharge failure such as a missing nozzle or a bent discharge, and the transparent recording head 7 that discharges the transparent ink has a high level. It is possible to confirm whether or not the image quality is suitable for high-definition image recording.

  Further, since the ink landing position of the transparent recording head 7 can be accurately grasped visually, the position of the transparent recording head 7 on the carriage 4 can be adjusted by checking the recording medium P on which the transparent ink is test printed. The drive adjustment of the carriage 4 in the scanning direction A and the conveyance direction can also be appropriately performed.

  In the present embodiment, the infrared irradiation device 19 is provided at one end on the outer side of the carriage 4 of the image recording apparatus 1, but the position where the infrared irradiation device 19 is provided is not limited to this. In addition, the image recording apparatus 1 is not provided with the infrared irradiation device 19, and after the recording medium P printed with the transparent ink is taken out from the image recording apparatus 1, the user emits infrared rays to the recording medium P using an external infrared light source. Irradiation and the landing position of the transparent ink colored by this may be confirmed visually.

  Further, in the image recording apparatus 1 applied in the present embodiment, one transparent recording head 7 is provided on the carriage 4, but the number of the transparent recording heads 7 is not limited to this, and a plurality of transparent recording heads 7 are provided. The transparent recording heads 7 may be arranged side by side. Further, the transparent recording heads 7 may be provided on both sides of the basic color recording heads 5, 5,.

  The image recording apparatus 1 to which the ejection failure detection method according to the present invention can be applied may use either the on-demand system or the continuous system recording heads 5, 5,... In addition, as a discharge method, for example, an electro-mechanical conversion method (for example, a single cavity type, a double cavity type, a bender type, a piston type, a shear mode type, a shared wall type, etc.), an electro-thermal conversion method (for example, , Thermal ink jet type, bubble jet (registered trademark) type), electrostatic suction type (for example, electric field control type, slit jet type, etc.) and discharge type (for example, spark jet type, etc.) The recording heads 5, 5,..., 7 may be used.

  In this embodiment, image recording is performed using ink that is cured by irradiation with ultraviolet rays. However, the ink is not necessarily limited to this, and for example, ultraviolet rays, electron beams, X-rays, and visible rays. The ink may be cured by irradiating light other than ultraviolet rays such as electromagnetic waves such as infrared rays. In this case, a polymerizable compound that is polymerized and cured with light other than ultraviolet light and a photoinitiator that initiates a polymerization reaction between the polymerizable compounds with light other than ultraviolet light are applied to the ink. In the case of using a photocurable ink that is cured by light other than ultraviolet light, a light source that emits the light is applied instead of the ultraviolet light source. Further, an ink that is cured and fixed without irradiating light may be used.

  Further, in the present embodiment, the image recording apparatus 1 performs recording while moving the recording heads 5, 5,..., 7 mounted on the carriage 4 back and forth in the main scanning direction Y and transporting the recording medium P in the transport direction X. The serial head type image recording apparatus 1 for forming an image by ejecting ink from the heads 5, 5,... 7 is an example of an image recording apparatus to which the ejection failure detection method according to the present invention can be applied. A line head type image recording apparatus that forms an image by ejecting ink from a recording head fixed to the recording head and transporting the recording medium P may be used.

  In addition, it is needless to say that the present invention is not limited to the above embodiment and can be modified as appropriate.

1 is a front view schematically showing a main part of an embodiment of an image recording apparatus to which an ejection failure detection method according to the present invention is applied. FIG. 6 is a diagram illustrating a state in which transparent ink used in the ejection failure detection method according to the present invention is ejected to a recording medium.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image recording device 5 Basic color recording head 6 Transparent recording head 9 Ultraviolet irradiation device 19 Infrared irradiation device A Main scanning direction Y Recording area

Claims (6)

  In the ejection failure detection method for detecting ejection failure of the transparent ink when image recording is performed by ejecting basic color ink and transparent ink from a recording head to a recording medium, the transparent ink absorbs infrared rays. The transparent ink is mixed by mixing the infrared absorbent that develops color, ejecting the transparent ink mixed with the infrared absorbent from the recording head, and irradiating the transparent ink landed on the surface of the recording medium with infrared rays. An ejection failure detection method characterized by visually detecting the situation.   The recording head heats ink, which is a liquid having a viscosity of 10 to 500 mPa · s at 30 ° C., to 30 to 150 ° C. by a heating unit, and discharges the ink so that one dot becomes a small droplet of 2 to 20 pl. The ejection failure detection method according to claim 1.   The ink is a photocurable ink that is cured by irradiating light, and irradiates the ink that has landed on the recording medium downstream of the recording head in the transport direction of the recording medium. The ejection failure detection method according to claim 1, further comprising an apparatus.   4. The ejection failure according to claim 3, wherein the ink is ultraviolet curable ink that is cured by irradiating ultraviolet rays, and at least a part of the light emitted from the light irradiation device is ultraviolet rays. 5. Detection method.   5. The ejection failure detection method according to claim 1, wherein the ink is a high-viscosity ink, and is a cationic polymerization ultraviolet curable ink.   The ejection failure detection method according to claim 1, wherein the ink has no ink absorptivity.

Images