JP2009149019A - Image forming device and method for cleaning intermediate transfer body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming device capable of excellently maintaining cleaning performance of a cleaning member, hardly affecting the image quality of a recorded image caused by performance deterioration of a cleaning means of an intermediate transfer body and a method of cleaning the intermediate transfer body. <P>SOLUTION: The method of cleaning the intermediate transfer body includes a step of judging whether the next region to be cleaned through the use of a cleaning-process means 16 is an image region with a first image to be formed or a non-image region other than the image region, in an inkjet recording apparatus 10 which transfers and records the first image on a recording medium 14 in a transfer recording part 24 after the first image is formed on an intermediate transfer belt 12. The method includes a step of reducing the supply amount of a cleaning liquid to be supplied from a cleaning liquid supply part 16C by 9-16% in comparison with the cleaning of the non-image region. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus and an intermediate transfer member cleaning method, and more particularly to an intermediate transfer member cleaning technique in an image forming apparatus to which a transfer recording method for transferring and recording a primary image formed on an intermediate transfer member onto a recording medium is applied. About.

  Currently, inkjet recording apparatuses are widely used as general-purpose image forming apparatuses. 2. Description of the Related Art Inkjet recording apparatuses are widely used as output devices that form high-definition images on a recording medium by ejecting ink droplets from an inkjet head. In recent years, for the purpose of further improving the reliability in image formation, an image (primary image) is formed by ejecting or applying ink and a color material aggregation reaction liquid on an intermediate transfer member, and the image is contacted with a recording medium. A transfer method is proposed. In an ink jet recording apparatus to which the transfer recording method is applied, it is necessary to remove dirt (mainly ink and color material aggregation reaction liquid) remaining on the intermediate transfer body after transfer recording. If the removal of the dirt is incomplete, there arises a problem that the dirt is transferred to the recording medium during the next transfer recording. Therefore, as a method of removing the stain on the intermediate transfer member after transfer recording, a method of removing the stain with a cleaning means such as a blade is used.

  Patent Document 1 discloses a cleaning device including a cleaning medium (roller) that removes ink on a transfer medium. The cleaning medium described in Patent Document 1 is made of a material having at least a surface with higher wettability than the transfer medium. When the cleaning medium is brought into contact with the transfer medium, the residual ink on the transfer medium is transferred to the cleaning medium. And configured to be removed.

Further, Patent Document 2 has a cleaning member stretched between two rollers in a transfer type ink jet recording apparatus, and after the liquid is applied to the intermediate transfer member layer or impregnated in the cleaning member, the cleaning member A transfer type inkjet recording apparatus configured to contact the intermediate transfer member layer, move the cleaning member continuously or intermittently, and wind up with the two rollers to wipe off the residual ink on the intermediate transfer member. Are listed.
JP 7-164624 A JP 2000-127356 A

  However, foreign matters such as ink or paper removed by the cleaning means fall mainly due to gravity, but a part of them adheres to the cleaning means. When ink or foreign matter adheres to the cleaning means, problems such as deterioration in cleaning performance, damage to the intermediate transfer member, and image defects due to reattachment of ink or foreign matter to the intermediate transfer member occur.

  In the invention described in Patent Document 1, ink attached to the surface of the cleaning medium is removed by scraping with a blade, but there is a problem that the ink attached to the blade is reattached to the cleaning medium. Further, since the cleaning performance of the transfer medium is improved by making the wettability of the cleaning medium higher than that of the transfer medium, it can be said that the ink adhering to the blade easily adheres to the cleaning medium. Therefore, the cleaning performance of the cleaning medium is impaired, and as a result, the cleaning performance of the transfer medium is deteriorated.

  Further, in the invention described in Patent Document 2, after wiping the intermediate transfer member using a cleaning member such as felt or nonwoven fabric impregnated with a cleaning liquid, the cleaning member is wound up by a roller, so that wiping residue or dirt can be removed. Prevents reattachment. In this method, when the cleaning member is continuously moved, the consumption of the cleaning member becomes enormous and the cost becomes high. Also, when the cleaning member is moved intermittently, the amount of cleaning liquid contained in the cleaning member varies when the intermediate transfer member is wiped due to the difference between the cleaning liquid impregnation time and the leaving time after the cleaning liquid impregnation. Will occur. In such a state, if the amount of the cleaning liquid is large, the cleaning liquid remains on the intermediate transfer member, and problems such as ink bleeding and transfer failure occur. On the other hand, if the amount of the cleaning liquid is small, the performance of removing dirt on the intermediate transfer member is lowered, and problems such as poor transfer and dirt on the recording medium occur. Therefore, it is necessary to adjust the cleaning liquid to an appropriate amount. is there.

  The present invention has been made in view of such circumstances, and can maintain good cleaning performance of the cleaning member, and can affect the image quality of the recorded image due to performance deterioration of the cleaning means of the intermediate transfer member. An object of the present invention is to provide an image forming apparatus and an intermediate transfer member cleaning method for preventing the above.

  In order to achieve the above object, an image forming apparatus according to the present invention forms an intermediate transfer member, a conveying unit that conveys the intermediate transfer member in a predetermined conveying direction, and a primary image on the intermediate transfer member. An image forming means, a transfer recording means for transferring and recording a primary image formed on the intermediate transfer body onto a recording medium, a cleaning liquid supply means for supplying a cleaning liquid to a region to be cleaned of the intermediate transfer body, A wiping means for wiping the intermediate transfer body supplied with the cleaning liquid from the cleaning liquid supply means to the cleaning target area; and an image area including an area where the cleaning target area of the intermediate transfer body forms a primary image. A cleaning target region determination unit that determines whether the target region is a non-image region other than the image region, and a cleaning target region determination unit. When it is determined that the area to be cleaned is an image area, the supply amount of the cleaning liquid supplied from the cleaning liquid supply unit is set so as to reduce the supply amount of the cleaning liquid with respect to the cleaning process of the non-image area. And a cleaning liquid supply control means for controlling.

  According to the present invention, the cleaning of the image forming area (the area where the amount of adhered matter such as ink is relatively small) is performed with a small amount of cleaning liquid, and the cleaning liquid is disposed downstream of the wiping means in the conveyance direction of the intermediate transfer member. The remaining state can be avoided. On the other hand, in the cleaning of non-image areas (areas where the amount of adhering matter such as ink is relatively large), the adhering matter adhering to the wiping means (adhering matter removed from the intermediate transfer member) is removed by supplying a large amount of cleaning liquid. It can be removed from the wiping member.

  In addition, since the supply amount of the cleaning liquid is changed according to the image area and the non-image area, the cleaning liquid supplied to the area to be cleaned becomes a necessary minimum amount, the consumption of the cleaning liquid is suppressed, and the waste liquid Can be minimized. Further, since the wiping means can be cleaned while the wiping means is in contact with the intermediate transfer member, the wiping means can be cleaned even during the recording operation, and the wiping means can be removed from the intermediate transfer member. It is possible to prevent the liquid residue from being generated on the intermediate transfer member during the separation.

  The image area is an area where a large amount of ink adheres when a primary image is formed by the image forming means, and the non-image area is an area excluding the image area.

  For the intermediate transfer member, a rotary member such as an endless belt or a drum shape is preferably used. When the rotary member is rotated once, the cleaning, primary image formation, and transfer recording steps are executed, and desired image recording is performed.

  As an example of the image forming unit, an aspect including a head for ejecting an image forming liquid for forming a primary image can be given. The image forming liquid is a concept including color inks. For example, when a primary image is formed with each color ink of yellow (Y), magenta (M), cyan (C), and black (K), each color of YMCK is changed to each color. An embodiment with a corresponding head is preferred.

  A mode in which a cleaning liquid supply unit and a wiping unit are disposed so as to clean the intermediate transfer member after transfer recording (before primary image formation) is preferable. In other words, each step is performed while the intermediate transfer member is conveyed in one direction, and the transfer recording unit is provided on the downstream side in the intermediate transfer member conveyance direction of the image forming unit, and the transfer recording unit is disposed on the downstream side in the intermediate transfer direction. A mode in which a cleaning liquid supply means is provided, a wiping means is provided downstream of the cleaning liquid supply means in the intermediate transfer member conveyance direction, and an image forming means is further provided downstream of the wiping means in the intermediate transfer member conveyance direction.

  As the wiping means, a wiping member such as a blade is preferably used. When a wiping member having a length corresponding to the width in the direction orthogonal to the conveyance direction of the intermediate transfer member is provided, the intermediate transfer member and the wiping member are moved to the intermediate transfer member without moving the wiping member in the width direction of the intermediate transfer member. It is possible to perform the wiping process over the entire width of the intermediate transfer member by moving it relatively in the transport direction.

  According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the cleaning target area determination unit determines an amount of deposits attached to the cleaning target area and supplies the cleaning liquid. When the cleaning unit determination unit determines that the amount of deposits attached to the cleaning target region is relatively large, the control unit relatively determines the supply amount of the cleaning liquid supplied from the cleaning liquid supply unit. On the other hand, when it is determined that the amount of deposits adhering to the area to be cleaned is relatively small, the supply amount of the cleaning liquid supplied from the cleaning liquid supply means is relatively reduced, According to the amount of deposits in the cleaning target area determined by the cleaning target area determination means, And controlling the supply amount of the cleaning liquid supplied from the cleaning liquid supply means.

  According to the second aspect of the invention, since the supply amount of the cleaning liquid supplied to the cleaning target area is switched according to the amount of the deposit on the cleaning target area, a small amount is obtained when the amount of the deposit on the cleaning target area is small. Cleaning is performed with the cleaning liquid, and it is possible to avoid a state in which the cleaning liquid remains on the downstream side of the wiping unit in the conveyance direction of the intermediate transfer body. On the other hand, when the amount of deposits in the area to be cleaned is large, a large amount of cleaning liquid is supplied. In this way, the deposits adhering to the wiping means (the deposits removed from the intermediate transfer member) can be removed from the wiping member.

  Since the primary image formed in the image area is transferred to the recording medium, the image area can be determined to be an area with little attached matter. On the other hand, the adhering matter adhering to the non-image area other than the image area remains without moving to other members or the like, so that the non-image area can be determined to be an area with more adhering matter than the image area.

  In the invention according to claim 2, a mode in which the amount of deposits on the intermediate transfer member is indirectly grasped from the use state of the intermediate transfer member is suitably applied.

  A third aspect of the present invention relates to an aspect of the image forming apparatus according to the first or second aspect, wherein the recording medium detecting unit detects the leading end and the trailing end of the recording medium after the transfer recording by the transfer recording unit. And the cleaning target area determination means determines that the cleaning target area is an image area when the recording medium detection means detects the leading edge of the recording medium, and the recording medium detection means determines the recording medium. When the rear end portion is detected, it is determined that the area to be cleaned is a non-image area.

  According to the third aspect of the present invention, it is possible to accurately determine the image area and the non-image area with a simple configuration.

  That is, the intermediate transfer member reaches the entrance of the cleaning processing area at the timing when the recording medium detection means detects the leading edge of the recording medium, and the intermediate transfer member is detected at the timing when the recording medium detection means detects the trailing edge of the recording medium. The position of the recording medium detection means on the recording medium conveyance path, the conveyance speed of the recording medium, and the conveyance speed of the intermediate transfer member are determined so as to reach the exit of the cleaning processing area.

  According to a fourth aspect of the present invention, there is provided the image forming apparatus according to the first or second aspect, further comprising a position detection unit that detects a position of the intermediate transfer member on a conveyance path, and the cleaning target region determination unit includes: The image area and the non-image area on the conveyance path of the intermediate transfer member are determined based on the image data, and the cleaning target area is an image area by comparing with the detection result of the position detection unit, or the non-image area It is characterized by determining whether it is.

  According to the invention of claim 4, by detecting the position of the intermediate transfer member on the conveyance path, and further grasping the image region and the non-image region on the intermediate transfer member by the image data, It is possible to accurately grasp the positions of the image area and the non-image area on the conveyance path of the intermediate transfer member.

  It is preferable that the position detection unit includes a detection pattern provided on the intermediate transfer member, a reading element that reads the detection pattern, and a counting unit that counts a reading signal obtained from the reading element. Also preferred is an aspect in which an origin detection element for detecting the origin (home position pattern) provided on the intermediate transfer member is provided, and the position of the intermediate transfer member on the conveyance path is grasped based on the distance from the origin of the intermediate transfer member. .

  A fifth aspect of the present invention relates to an aspect of the image forming apparatus according to any one of the first to fourth aspects, wherein the cleaning liquid supply unit applies the first cleaning liquid to the intermediate transfer member. A first cleaning liquid supply section for supplying, and a second cleaning liquid supply section for supplying a second cleaning liquid having a surfactant content smaller than that of the first cleaning liquid to the intermediate transfer member, The cleaning liquid supply control means supplies the first cleaning liquid from the first cleaning liquid supply unit during the cleaning process of the non-image area, and the second cleaning liquid supply unit during the cleaning process of the image area. And controlling the first cleaning liquid supply unit and the second cleaning liquid supply unit so as to supply the second cleaning liquid from the first cleaning liquid supply unit. .

  According to the fifth aspect of the present invention, when the image area is cleaned, the first cleaning liquid containing a large amount of the surfactant is used to move the adhered matter adhering to the intermediate transfer member to the wiping member. It becomes easy. Further, when cleaning the non-image area, the second cleaning liquid having a low concentration of the surfactant is used to reduce the concentration of the surfactant in the cleaning liquid attached to the wiping member, thereby generating bubbles in the wiping member. Is prevented.

  A liquid that does not contain a surfactant may be applied as the second cleaning liquid, and a mode in which pure water is used as the second cleaning liquid is preferable.

  A sixth aspect of the present invention relates to an aspect of the image forming apparatus according to any one of the first to fourth aspects, wherein the cleaning liquid supply unit applies the first cleaning liquid to the intermediate transfer member. A cleaning liquid supply control unit including a first cleaning liquid supply unit to be supplied and a second cleaning liquid supply unit to supply a second cleaning liquid having a viscosity lower than that of the first cleaning liquid to the intermediate transfer member; The means supplies the first cleaning liquid from the first cleaning liquid supply part during the cleaning process of the non-image area, and the second cleaning liquid from the second cleaning liquid supply part during the cleaning process of the image area. The first cleaning liquid supply unit and the second cleaning liquid supply unit are controlled to supply liquid.

  According to the sixth aspect of the present invention, when the image area is cleaned, the first cleaning liquid having a higher viscosity is used, so that the cleaning liquid is easily attached to the intermediate transfer body and is easily held by the wiping member. As a result, convection of the cleaning liquid occurs, and it becomes easy to move the deposit (dirt) adhering to the intermediate transfer member to the wiping member. Further, even when the supply liquid amount varies, the deposits can be reliably removed.

  On the other hand, when cleaning the non-image area, the second cleaning liquid having a lower viscosity is used, so that the second cleaning liquid can easily slide (flow easily) from the wiping member, and the deposits on the wiping member are removed. It becomes easy to do.

  A mode in which the viscosity of the second cleaning liquid having a viscosity lower than that of the first cleaning liquid is equal to or lower than the viscosity of the image forming liquid used for primary image formation is preferable.

  A seventh aspect of the invention relates to an aspect of the image forming apparatus according to the sixth aspect, wherein the cleaning liquid supply means includes a first cleaning liquid supply path that communicates with the first cleaning liquid supply section; A second cleaning liquid supply path that communicates with the second cleaning liquid supply section; a first cleaning liquid supply path that communicates with the first cleaning liquid supply path; and the second cleaning liquid supply path; Cleaning liquid storage means for storing a common cleaning liquid supplied to the second cleaning liquid supply section; heating means for heating the cleaning liquid in the first cleaning liquid supply path; and the second cleaning liquid. Cooling means for cooling the liquid in the liquid supply path, and the common cleaning liquid whose viscosity has been lowered by the heating means is used as the first cleaning liquid. Supplies from the sheet portion to the intermediate transfer body, and supplying said common cleaning solution viscosity increased by the cooling means from the second cleaning liquid supply section to the intermediate transfer member.

  According to the seventh aspect of the present invention, two types of cleaning liquids having different viscosities can be generated from a common cleaning liquid with a simple configuration.

  The invention according to an eighth aspect relates to an aspect of the image forming apparatus according to at least one of the first to seventh aspects, and further includes a measuring unit that measures an elapsed time from the end of image recording, When the elapsed time measured by the measuring unit exceeds a predetermined time, the intermediate transfer member is transported in a predetermined transport direction without operating the image forming unit, and from the cleaning liquid supply unit. The cleaning process for the intermediate transfer member is performed by supplying a cleaning liquid to the intermediate transfer member under the same conditions as in the cleaning process for the non-image area.

  According to the eighth aspect of the present invention, even when the deposit is left on the intermediate transfer member and the wiping means at the time of quiet recording or interruption processing, the deposit cannot be removed. In addition, since the adhering matter is removed, poor cleaning is prevented, and a preferable state of the intermediate transfer member and the wiping means is maintained.

  A ninth aspect of the invention relates to an aspect of the image forming apparatus according to at least one of the first to eighth aspects of the invention, and cleaning of an area determined as a non-image area by the cleaning target area determining unit. In the processing, cleaning liquid is supplied from the cleaning liquid supply means to a contact position between the intermediate transfer member and the wiping means, and in the cleaning processing of the area determined as the image area by the cleaning target area determination means, the intermediate A moving means is provided for moving the cleaning liquid supply means so as to supply the cleaning liquid from the cleaning liquid supply means to a position separated from the contact position between the transfer body and the wiping means by a predetermined distance. And

  According to the ninth aspect of the present invention, in the cleaning of the image area, the cleaning liquid is supplied to a position away from the contact position of the intermediate transfer member and the wiping means (positioning position of the wiping means). Is ensured to dissolve (disperse) in the cleaning liquid. Further, in cleaning the non-image area, the cleaning liquid is supplied to the contact position between the intermediate transfer body and the wiping unit, so that the cleaning liquid supplied to the intermediate transfer body moves to the position of the wiping unit. Is prevented from slipping off, and the pressure when supplying the cleaning liquid is applied to the wiping means, so that the deposits attached to the wiping means can be easily removed.

  It is preferable that the moving unit moves the cleaning liquid supply unit in a direction parallel to the conveyance direction of the intermediate transfer member.

  A tenth aspect of the present invention relates to an aspect of the image forming apparatus according to at least one of the first to eighth aspects of the present invention, and cleaning an area determined as a non-image area by the cleaning target area determining unit. In the processing, cleaning liquid is supplied from the cleaning liquid supply means to a contact position between the intermediate transfer member and the wiping means, and in the cleaning processing of the area determined as the image area by the cleaning target area determination means, the intermediate More than 0 ° and 90 ° with respect to the transport direction of the intermediate transfer body so that the cleaning liquid is supplied from the cleaning liquid supply means to a position separated from the contact position between the transfer body and the wiping means by a predetermined distance. The cleaning liquid supply means is rotated about a rotation axis in the direction of the following angle to change the cleaning liquid ejection direction, Rotating means for changing the supply position of the cleaning liquid in the intermediate transfer member is provided.

  By changing the ejection direction (supply direction) of the cleaning liquid, it is possible to change the supply position of the cleaning liquid without moving the cleaning liquid supply means.

  An eleventh aspect of the present invention relates to an aspect of the image forming apparatus according to any one of the first to tenth aspects, wherein the image forming unit reacts with ink forming a primary image and A treatment liquid applying means for applying a treatment liquid that thickens, aggregates or insolubilizes the ink to the intermediate transfer body; a drying means for drying the treatment liquid applied to the intermediate transfer body by the treatment liquid application means; and the ink. And a head for ejecting droplets onto the intermediate transfer member.

  According to the eleventh aspect of the invention, since the dried processing liquid remains in the non-image forming area, the cleaning liquid supply amount is larger than the cleaning of the image area in cleaning the non-image forming area. The processing liquid adhering to the non-image area can be reliably removed.

  In addition to the structure described in claim 11, an aspect provided with a solvent removing means for removing excess solvent on the intermediate transfer member after primary image formation is preferable.

  The intermediate transfer member cleaning method according to the twelfth aspect of the invention forms a primary image while conveying the intermediate transfer member in a predetermined conveyance direction, and the primary image formed on the intermediate transfer member. A method for cleaning an intermediate transfer member in an image forming apparatus for transferring and recording a recording medium, wherein the region to be cleaned of the intermediate transfer member is an image region including a region for forming a primary image, or other than the image region If the cleaning target area is determined to be an image area, the supply of the cleaning liquid is reduced so that the supply amount of the cleaning liquid is less than that during the cleaning process of the non-image area. The amount is controlled, and the intermediate transfer member supplied with the cleaning liquid to the area to be cleaned is wiped off.

  Since the supply amount of the cleaning liquid is changed according to the amount of deposits in the area to be cleaned, a preferable cleaning process is performed.

  According to the present invention, the cleaning of the image forming area (the area where the amount of adhered matter such as ink is relatively small) is performed with a small amount of cleaning liquid, and the cleaning liquid is disposed downstream of the wiping means in the conveyance direction of the intermediate transfer member. The remaining state can be avoided. On the other hand, in the cleaning of non-image areas (areas where the amount of adhering matter such as ink is relatively large), the adhering matter adhering to the wiping means (adhering matter removed from the intermediate transfer member) is removed by supplying a large amount of cleaning liquid. It can be removed from the wiping member.

  In addition, since the supply amount of the cleaning liquid is changed according to the image area and the non-image area, the cleaning liquid supplied to the area to be cleaned becomes a necessary minimum amount, the consumption of the cleaning liquid is suppressed, and the waste liquid Can be minimized. Further, since the wiping means can be cleaned while the wiping means is in contact with the intermediate transfer member, the wiping means can be cleaned even during the recording operation, and the wiping means can be removed from the intermediate transfer member. It is possible to prevent the liquid residue from being generated on the intermediate transfer member during the separation.

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

[First Embodiment]
<Device configuration>
FIG. 1 is a schematic configuration diagram of an ink jet recording apparatus according to the first embodiment of the present invention. The ink jet recording apparatus 10 shown in the figure forms a primary image that becomes a mirror image of a recorded image in an image area (not shown in FIG. 1, indicated by reference numeral 100 in FIG. 10) of the intermediate transfer belt 12, and then the primary image This is an image forming apparatus to which a transfer recording method for transferring and recording an image on a recording medium 14 is applied.

  As shown in FIG. 1, the ink jet recording apparatus 10 includes an intermediate transfer belt 12 on which a primary image is formed, and a cleaning for removing deposits such as ink adhering to the intermediate transfer belt 12 before forming the primary image. A cleaning processing unit 16 including a cleaning liquid supply unit 16C that supplies the cleaning liquid 16B to the blade 16A and the intermediate transfer belt 12 during the cleaning process, and an intermediate transfer belt conveyance direction of the cleaning processing unit 16 (indicated by reference numeral A in FIG. 1) A processing liquid application unit 18 that is provided on the downstream side and applies a processing liquid that reacts with the ink and thickens or aggregates (insolubilizes) the ink in the image area of the intermediate transfer belt 12, and the intermediate transfer belt of the processing liquid application unit 18. A drying processing unit 20 provided on the downstream side in the transport direction and drying the processing liquid applied to the intermediate transfer belt 12, and a drying processing unit 2 Ink jet heads 22Y corresponding to Y (yellow), M (magenta), C (cyan), and K (black) inks, which are provided on the downstream side of the intermediate transfer belt in the conveying direction and are ejected according to image data. An intermediate transfer belt provided between a printing unit 22 including 22M, 22C, and 22K, and a counter roller (heating roller) 24B and a transfer roller 24C provided downstream of the printing unit 22 in the conveyance direction of the intermediate transfer belt. 12 and the recording medium 14 are pressed, and the intermediate transfer belt 12 (primary image) and the recording medium 14 are heated to a predetermined transfer temperature by a heater 24A built in the opposing roller 24B. And a transfer recording unit 24 that transfers and records the next image onto the recording medium 14.

  Although not shown, a solvent removal unit that removes the solvent on the intermediate transfer belt 12 after the primary image is formed between the printing unit 22 and the transfer recording unit 24, and an intermediate after the solvent removal. A preheating unit that preheats the transfer belt 12 (primary image), and further includes a cooling unit that cools the recording medium 14 after the transfer recording and the intermediate transfer belt 12 at the subsequent stage of the transfer recording unit 24, A separation unit that separates the recording medium 14 after transfer recording from the intermediate transfer belt 12 on the rear side of the part, a fixing unit that fixes the image transferred and recorded on the recording medium 14 on the rear side of the separation unit, and image fixing A discharge unit that discharges the processed recording medium 14 to the outside of the inkjet recording apparatus 10.

  Furthermore, a supply tray (not shown) for storing the recording medium 14, a paper feeding unit for supplying the recording medium 14 from the supply tray to the transfer recording unit 24 (a conveyance direction of the recording medium 14 is indicated by a symbol B), I have. When a long recording medium is cut into a predetermined size and used, a cutter for cutting the recording medium into a predetermined size is provided.

  The cleaning processing unit 16 includes a cleaning blade 16A for wiping and removing ink droplets and processing liquid remaining on the intermediate transfer belt 12 before printing (after transfer recording), and a cleaning liquid 16B for the intermediate transfer belt 12 during the cleaning process. A cleaning liquid supply part 16C for supplying the liquid, a recovery part 16D for recovering deposits such as ink removed by the cleaning blade 16A, and a recovery tank 16F communicated via the recovery part 16D and the recovery tube 16E. It consists of

  As shown in FIG. 1, in the processing area of the cleaning processing unit 16, the image surface of the intermediate transfer belt 12 faces obliquely downward, and the intermediate transfer belt 12 after transfer recording is conveyed obliquely upward. The present invention can also be applied to the cleaning of the surface facing the lower side of the intermediate transfer belt 12 conveyed in the horizontal direction.

  The cleaning blade 16A is in contact with the intermediate transfer belt 12 from the lower side of the intermediate transfer belt 12, and has a length exceeding the entire width of the intermediate transfer belt 12 (the length in the direction orthogonal to the intermediate transfer belt conveyance direction A). By moving the intermediate transfer belt 12 in one direction while bringing the cleaning blade 16 </ b> A into contact with the intermediate transfer belt 12, the entire width of the intermediate transfer belt 12 can be cleaned at once.

  The cleaning liquid supply unit 16 </ b> C shown in FIG. 1 employs an injection method in which the cleaning liquid 16 </ b> B is sprayed from the lower side of the intermediate transfer belt 12. Although not shown, the cleaning liquid supply unit 16C has a structure capable of supplying the cleaning liquid to the entire width of the intermediate transfer belt 12 at a time. In other words, the cleaning liquid supply unit 16C is configured to supply the cleaning liquid to the entire width of the intermediate transfer belt 12 without moving the cleaning liquid supply unit 16C in the width direction of the intermediate transfer belt 12. The cleaning liquid supply unit 16C has a structure that communicates with the cleaning liquid tank 36 via the pump 32 and the cleaning liquid supply path 34. When the pressure of the pump 32 is increased, the supply amount (injection amount) of the cleaning liquid increases. It is comprised so that it may become.

  Although details of control of the flow rate (supply amount) of the cleaning liquid will be described later, a recording medium that detects the leading end and the trailing end of the recording medium 14 on the downstream side of the recording medium 14 in the recording medium conveyance direction (shown by an arrow line B) When the detection sensor 38 is provided and the detection signal of the recording medium detection sensor 38 is sent to the image region determination unit 40, the image region determination unit 40 determines that the cleaning process target region of the cleaning processing unit 16 is an image region based on the detection signal. Or a non-image area (denoted by reference numeral 102 in FIG. 10), and if the cleaning process target area is determined to be an image area, the cleaning liquid flow rate control unit 42 applies to the non-image area. Compared with the case where the cleaning process is performed, the pressure of the pump 32 is lowered, and the ejection of the cleaning liquid supply unit 16C is controlled so as to decrease the supply amount of the cleaning liquid.

  That is, when the leading end of the recording medium 14 is detected by the recording medium detection sensor 38, the arrangement of the recording medium detection sensor 38 or the like so that the leading end of the image area of the intermediate transfer belt 12 reaches the processing area of the cleaning processing unit 16. The arrangement of the cleaning processing unit 16, the conveyance speed of the intermediate transfer belt 12, and the like are determined. When the leading end of the recording medium 14 is detected by the recording medium detection sensor 38, the pressure of the pump 32 shown in FIG. When the supply amount of the liquid is decreased and the rear end portion of the recording medium 14 is detected by the recording medium detection sensor 38, the pressure of the pump 32 is increased (returned back) to increase the supply amount of the cleaning liquid (original) Back to).

  A platen 26 that supports the back side of the intermediate transfer belt 12 (opposite the image surface including the image area) is provided in the processing area of the cleaning processing unit 16 to ensure the rigidity of the intermediate transfer belt 12 during the cleaning process. Note that various types of wiping members such as a roller-shaped wiping member and a brush-shaped wiping member may be applied instead of the cleaning blade 16A.

  An endless belt is applied to the intermediate transfer belt 12 shown in FIG. 1, and the intermediate transfer belt 12 has a structure wound around a plurality of rollers (stretching rollers 28A and 28B and a counter roller 24B). The power of a motor (not shown in FIG. 1, not shown in FIG. 7 and indicated by reference numeral 88) is transmitted to at least one of 28A and 28B, so that the intermediate transfer belt 12 is conveyed in a predetermined direction counterclockwise in FIG. Driven at speed. In this example, the conveyance speed (maximum value) of the intermediate transfer belt 12 is 500 mm / s.

  For the surface layer including the image surface of the intermediate transfer belt 12, a non-permeable material such as a polyimide resin is preferably used. In addition, it is also possible to apply a medium having a low permeation rate with respect to the treatment liquid instead of or in combination with a non-permeable material (medium). The “medium having a low permeation speed” means that the decrease in the amount (thickness) of the processing liquid is more than 1% and not more than 10% from the time when the processing liquid is applied to the time when it moves directly below the printing unit 22. A medium or a medium having a slow permeability of 1% or less in decrease in the amount (thickness) of the processing liquid from the time when the processing liquid is applied to the time it moves directly below the printing unit 22.

  As a preferable material used for the surface layer including the image surface of the intermediate transfer belt 12, in addition to the polyimide resin, a silicon resin, a polyurethane resin, a polyester resin, a polystyrene resin, a polyolefin resin, a polybutadiene resin, Known materials such as polyamide-based resins, polyvinyl chloride-based resins, polyethylene-based resins, and fluorine-based resins can be used.

  Further, it is preferable that the surface tension of the surface layer of the intermediate transfer belt 12 is 10 mN / m or more and 40 mN / m or less. When the surface tension of the surface layer of the intermediate transfer belt 12 exceeds 40 mN / m, the surface tension difference from the recording medium 14 on which the primary image is transferred and recorded is eliminated (or extremely small), and the primary image ( Transferability of the ink aggregates is deteriorated.

  Further, when the surface tension of the surface layer of the intermediate transfer belt 12 is less than 10 mN / m, the surface tension of the processing liquid is less than the surface tension of the surface layer of the intermediate transfer belt 12 in consideration of the wettability of the processing liquid. However, it is difficult to make the surface tension of the treatment liquid less than 10 mN / m in terms of the composition of the treatment liquid. Therefore, when the surface tension of the surface layer of the intermediate transfer belt 12 is less than 10 mN / m, the design freedom (selection range) of the intermediate transfer belt 12 and the processing liquid is narrowed.

  In addition, it is more preferable that the surface layer of the intermediate transfer belt 12 has irregularities with a surface roughness Ra of about 0.3 μm because the movement of ink droplets and ink aggregates is suppressed.

  The treatment liquid application unit 18 applies a treatment liquid uniformly over the entire image area of the intermediate transfer belt 12 using an application roller (actually, an area wider than the image area), or a liquid from an inkjet head. An ink jet system for ejecting droplets of the treated treatment liquid is preferably used.

  In the coating method, a coating roller using a porous material or a material having irregularities on the surface is preferable. For example, a gravure roll-shaped one can be used. The application roller may have a length corresponding to the entire width of the intermediate transfer belt 12, or a plurality of application rollers having a length shorter than the entire width of the intermediate transfer belt 12 are arranged in the width direction of the intermediate transfer belt 12. It may correspond to the full width of the intermediate transfer belt 12 (for example, arranged in a staggered manner).

  In order to control the application amount of the treatment liquid by the treatment liquid application unit 18, it is preferable to control the contact time between the application roller and the intermediate transfer belt 12. When the contact time between the application roller and the intermediate transfer belt 12 is relatively long, the amount of the treatment liquid applied becomes relatively large. When the contact time between the application roller and the intermediate transfer belt 12 is relatively short, the treatment liquid is applied. The amount is relatively small. In addition, it is more preferable that the application roller pressing control with respect to the intermediate transfer belt 12 is used in combination.

  The treatment liquid applied by the treatment liquid application unit 18 has a function of thickening or aggregating (insolubilizing) ink droplets applied from the printing unit 22 (heads 22Y, 22M, 22C, 22K).

  Examples of the treatment liquid applicable to this example include a treatment liquid containing polyethylene fine particles or paraffin fine particles, a surfactant such as phosphoric acid and orphine, and pure water. A preferable range of the coating thickness of the treatment liquid in this example is 3 μm or more and 10 μm or less.

  An infrared heater is preferably used for the drying processing unit 20, and the intermediate transfer belt 12 after application of the treatment liquid is heated to evaporate water (solvent component) on the intermediate transfer belt 12. In this example, the heating temperature is in the range of 70 to 120 ° C., and the heating time is 0.5 to 5.0 seconds (the heating time is determined by the conveyance speed of the intermediate transfer belt 12). The setting of the heating temperature and the heating time is appropriately changed according to the environmental temperature, the physical properties of the treatment liquid used and the physical properties of the ink.

  Each head 22Y, 22M, 22C, 22K of the printing unit 22 has a length corresponding to the maximum width of the image area on the intermediate transfer belt 12 (see FIG. 2), and the ink discharge surface covers the entire width of the image area. This is a full line type head in which a plurality of nozzles (not shown in FIG. 1, indicated by reference numeral 51 in FIG. 3A) are arranged.

  The heads 22Y, 22M, 22C, and 22K are arranged in the order of black (K), yellow (Y), magenta (M), and cyan (C) from the upstream side along the conveyance direction of the intermediate transfer belt 12, and each of them. The heads 22Y, 22M, 22C, and 22K are fixedly installed so as to extend in a direction orthogonal to the conveyance direction of the intermediate transfer belt 12.

  According to the configuration in which the full-line type head having the nozzle row covering the entire width of the intermediate transfer belt 12 is provided for each color ink and the processing liquid, the conveyance direction of the intermediate transfer belt 12 (sub-scanning direction, FIG. 3). 1), the primary image is formed in the image area of the intermediate transfer belt 12 only by performing the operation of relatively moving the intermediate transfer belt 12 and the printing unit 22 once (that is, by one sub-scan). Can do. As a result, the heads 22Y, 22M, 22C, and 22K can perform high-speed printing as compared with a serial (shuttle) type head that reciprocates in the main scanning direction (see FIG. 3A) orthogonal to the conveyance direction of the intermediate transfer belt 12. Thus, print productivity can be improved.

  A water-based pigment ink is preferably used in the inkjet recording apparatus 10 shown in this example. In addition to the pigment, the ink contains a high boiling point solvent such as glycerin and diethylene glycol, a surfactant, a pH adjusting agent, pure water, and the like. All the above components remain on the intermediate transfer belt 12 after transfer recording, and in particular, most of the polyethylene fine particles or paraffin fine particles remain on the intermediate transfer belt 12.

  In this example, the configuration of the standard colors (four colors) of KYMC is exemplified, but the combination of ink colors and the number of colors is not limited to this embodiment, and light ink, dark ink, and special color ink are used as necessary. May be added. For example, it is possible to add an ink head that discharges light-colored ink such as light cyan and light magenta, and the arrangement order of the color heads is not particularly limited.

  As shown in FIG. 1, a platen 30 that supports the intermediate transfer belt 12 from the back side surface is provided in an area from the processing liquid application unit 18 to the printing unit 22 to ensure the rigidity of the intermediate transfer belt 12 in the area. is doing.

  Ink storage / loading units (not shown) for storing the inks of the respective colors supplied to the heads 22Y, 22M, 22C, and 22K shown in FIG. 1 are inks of the colors corresponding to the heads 22Y, 22M, 22C, and 22K. The ink tanks for each color are communicated with the heads 22Y, 22M, 22C, and 22K for each color through a required flow path. The ink storage / loading unit includes notifying means (display means, warning sound generating means) for notifying when the ink remaining amount is low, and has a mechanism for preventing erroneous loading between colors. Yes. The processing liquid head also includes a processing liquid storage / loading unit having the same configuration as the ink storage / loading unit.

  The preheating unit is provided with a flat plate heater (not shown in FIG. 1 and representative of a plurality of types of heaters in FIG. 7 by reference numeral 89) on the back side of the image surface of the intermediate transfer belt 12. The intermediate transfer belt 12 on which an image is formed is configured to be able to be heated in the range of 50 ° C. or higher and 70 ° C. or lower. An embodiment in which a flat plate heater is built in the intermediate transfer belt 12 is also preferable.

  Further, the temperature of the intermediate transfer belt 12 in the preheating is preferably set lower than the heating temperature at the time of transfer. Furthermore, it is preferable that the preheating temperature is set according to the melting temperature of the fine particles (resin fine particles) contained in the treatment liquid or ink and the glass transition temperature, since transferability at the time of transfer recording can be improved.

  As described above, by preheating the image area of the intermediate transfer belt 12, it is possible to shorten the time required for the transfer recording unit 24 to reach a predetermined transfer temperature as compared with the case where the preheating is not performed. The time required for the entire transfer process in the transfer recording unit 24 can be shortened.

  Specific examples of the recording medium 14 applied to this example include permeable media such as plain paper and inkjet exclusive paper, non-permeable or low permeable media such as coated paper, and adhesive and release labels on the back surface. There are various media such as sticker paper, resin films such as OHP sheets, metal sheets, cloth, and wood.

  The transfer recording unit 24 includes a counter roller (back roller) 24B having a built-in heater 24A, and a transfer roller 24C provided to face the counter roller 24B. The transfer roller 24C and the transfer roller 24C connect the intermediate transfer belt 12 to the intermediate transfer belt 12. The intermediate transfer belt 12 is sandwiched between the recording medium 14 and heated to a predetermined transfer temperature (for example, a temperature equal to or higher than the softening point of the resin fine particles contained in the ink) and pressurized with a predetermined transfer pressure (nip pressure). The primary image formed above is transferred to the recording medium 14.

  The heating temperature during transfer by the transfer recording unit 24 is preferably 70 ° C. or higher and 90 ° C. or lower. When the heating temperature at the time of transfer by the transfer recording unit 24 is 90 ° C. or higher, there is a problem such as deformation of the intermediate transfer belt 12, and when it is 70 ° C. or lower, the transfer property is deteriorated.

  It is preferable that the nip pressure in the transfer recording portion 24 is 0.5 MPa or more and 3.0 MPa or less. Examples of means for adjusting the nip pressure during transfer include a mechanism (drive means) that moves the transfer roller 24C in the vertical direction in FIG.

  A cooling unit (not shown) cools the intermediate transfer belt 12 and the recording medium 14 that are past each other through the transfer recording unit 24. In the cooling unit, a mode in which cool air is blown by a cooling fan or the like is applied, and it is preferable that the cooling temperature or the like can be adjusted. The cooling unit of this example has a configuration in which a moving time (cooling time) of the intermediate transfer belt 12 for cooling the intermediate transfer belt 12 and the recording medium 14 to a desired temperature is secured. When the intermediate transfer belt 12 and the recording medium 14 are peeled off after cooling to a desired temperature, transfer defects due to temperature unevenness can be prevented, and stable image transfer (peeling) becomes possible.

  The peeling unit (not shown) is configured to peel the recording medium 14 from the intermediate transfer belt 12 with the rigidity (waist strength) of the recording medium 14 itself by the winding curvature of a peeling roller (not shown) of the intermediate transfer belt 12. Has been. A means for promoting peeling such as a peeling nail may be used in combination with the peeling portion.

  The fixing unit (not shown) includes a heating roller pair whose temperature can be adjusted in the range of 50 ° C. or more and 200 ° C. or less, and applies a pressure of 0.5 MPa or more and 3.0 MPa or less at a predetermined fixing temperature for recording. The main image is fixed on the medium 14.

  In this example, since at least one of the treatment liquid and the ink contains polymer fine particles, the polymer fine particles are formed (by forming a thin film in which the polymer fine particles are dissolved on the outermost surface of the image), Fixability and scratch resistance can be improved. If the transfer recording unit 24 can achieve both transferability and film formation, a mode in which the fixing unit is omitted is also possible.

<Head structure>
Next, the structure of the heads 22Y, 22M, 22C, and 22K shown in FIGS. 1 and 2 will be described in detail. Since the structures of the ink heads 22Y, 22M, 22C, and 22K are the same, the head is represented by the reference numeral 50 in the following.

  FIG. 3A is a plan perspective view showing an example of the structure of the head 50, and FIG. 3B is an enlarged view of a part thereof. 3C is a perspective plan view showing another example of the structure of the head 50, and FIG. 4 is a sectional view showing the three-dimensional configuration of the ink chamber unit (4-4 in FIGS. 3A and 3B). It is sectional drawing which follows a line.

  In order to increase the dot pitch formed on the intermediate transfer belt 12, it is necessary to increase the nozzle pitch in the head 50. As shown in FIGS. 3A and 3B, the head 50 of this example includes a plurality of ink chamber units 53 including nozzles 51 that are ink droplet ejection holes and pressure chambers 52 corresponding to the nozzles 51. Nozzles that are arranged in a staggered matrix (two-dimensionally), and are thus projected in a row along the head longitudinal direction (sub-scanning direction perpendicular to the paper feed direction). High density of the interval (projection nozzle pitch) is achieved.

  The configuration in which one or more nozzle rows are configured over a length corresponding to the entire width of the intermediate transfer belt 12 in a direction substantially orthogonal to the conveyance direction of the intermediate transfer belt 12 is not limited to this example. For example, instead of the configuration of FIG. 3A, as shown in FIG. 3C, short head blocks 50 ′ in which a plurality of nozzles 51 are two-dimensionally arranged are arranged in a staggered manner and joined together. A line head having a nozzle row having a length corresponding to the entire width of the intermediate transfer belt 12 may be configured. Although not shown, a line head may be configured by arranging short heads in a line.

  The pressure chamber 52 provided corresponding to each nozzle 51 has a substantially square planar shape, and the nozzle 51 and the supply port 54 are provided at both corners on the diagonal line. Each pressure chamber 52 communicates with a common flow channel 55 through a supply port 54. The common channel 55 communicates with an ink supply tank (not shown in FIG. 4, not shown in FIG. 6 and indicated by reference numeral 60) as an ink supply source, and the ink supplied from the ink supply tank is the common channel 55 shown in FIG. Is distributed and supplied to each pressure chamber 52.

  A piezoelectric element 58 having an individual electrode 57 is joined to a diaphragm 56 that constitutes the top surface of the pressure chamber 52 and also serves as a common electrode. By applying a driving voltage to the individual electrode 57, the piezoelectric element 58 is Deformation causes ink to be ejected from the nozzle 51. When ink is ejected, new ink is supplied from the common channel 55 to the pressure chamber 52 through the supply port 54.

  As shown in FIG. 5, the ink chamber unit 53 having such a structure is latticed in a fixed arrangement pattern along a row direction along the main scanning direction and an oblique column direction having a constant angle θ not orthogonal to the main scanning direction. The high-density nozzle head of this example is realized by arranging a large number in the shape.

  That is, with a structure in which a plurality of ink chamber units 53 are arranged at a constant pitch d along the direction of an angle θ with respect to the main scanning direction, the pitch P of the nozzles projected in the main scanning direction is d × cos θ. Thus, in the main scanning direction, each nozzle 51 can be handled equivalently as a linear arrangement with a constant pitch P. With such a configuration, it is possible to realize a high-density nozzle configuration in which 2400 nozzle rows are projected per inch (2400 nozzles / inch) so as to be aligned in the main scanning direction.

  When the nozzles are driven by a full line head having a nozzle row having a length corresponding to the entire printable width, (1) all the nozzles are driven simultaneously, (2) the nozzles are sequentially moved from one side to the other. (3) The nozzle is divided into blocks, each block is sequentially driven from one side to the other, and the like, and the width direction of the intermediate transfer belt 12 (direction perpendicular to the conveyance direction of the intermediate transfer belt 12) ) Is defined as main scanning to drive one line (a line composed of a single row of dots or a line composed of a plurality of rows of dots).

  In particular, when driving the nozzles 51 arranged in a matrix as shown in FIGS. 3A and 3B, the main scanning as described in the above (3) is preferable. That is, nozzles 51-11, 51-12, 51-13, 51-14, 51-15, 51-16 are made into one block (other nozzles 51-21,..., 51-26 are made into one block, Nozzles 51-31,..., 51-36 as one block,...), And the nozzles 51-11, 51-12,. One line is printed in the width direction of the transfer belt 12.

  On the other hand, by moving the full line head and the intermediate transfer belt 12 relative to each other, printing of one line (a line formed by one line of dots or a line composed of a plurality of lines) formed by the main scanning described above is repeated. What is done is defined as sub-scanning.

  The direction indicated by one line (or the longitudinal direction of the belt-like region) recorded by the main scanning is referred to as a main scanning direction, and the direction in which the sub scanning is performed is referred to as a sub scanning direction. That is, in the present embodiment, the conveyance direction of the intermediate transfer belt 12 is the sub-scanning direction, and the width direction of the intermediate transfer belt 12 perpendicular to the conveyance direction is the main scanning direction. In the implementation of the present invention, the nozzle arrangement structure is not limited to the illustrated example.

  In this embodiment, a method of ejecting ink droplets by deformation of the piezoelectric element 58 typified by a piezo element (piezoelectric element) is employed. However, in the practice of the present invention, the method of ejecting ink is particularly limited. Instead of the piezo jet method, various methods such as a thermal jet method in which ink is heated by a heating element such as a heater to generate bubbles and ink droplets are ejected by the pressure can be applied.

  The scope of application of the present invention is not limited to a printing method using a line type head, and a short head that is less than the length in the width direction of the intermediate transfer belt 12 is scanned in the width direction of the intermediate transfer belt 12 to print in the width direction. When the printing in the width direction is completed once, the intermediate transfer belt 12 is moved by a predetermined amount in the direction orthogonal to the width direction, and printing in the width direction of the intermediate transfer belt 12 in the next printing area is performed. A serial system that performs printing over the entire printing area of the intermediate transfer belt 12 by repeating the operation may be applied.

<Supply system configuration>
FIG. 6 is a schematic diagram showing the configuration of the ink supply system in the inkjet recording apparatus 10.

  The ink supply tank 60 is a base tank that supplies ink to the head 50 and is included in the ink storage / loading unit described above. The ink supply tank 60 includes a system that replenishes ink from a replenishment port (not shown) and a cartridge system that replaces the entire tank when the remaining amount of ink is low. A cartridge system is suitable for changing the ink type according to the intended use. In this case, it is preferable that the ink type information is identified by a barcode or the like, and ejection control is performed according to the ink type.

  As shown in FIG. 6, a filter 62 is provided between the ink supply tank 60 and the head 50 in order to remove foreign substances and bubbles. The filter mesh size is preferably equal to or smaller than the nozzle diameter (generally about 20 μm).

  Although not shown in FIG. 6, a configuration in which a sub tank is provided in the vicinity of the head 50 or integrally with the head 50 is also preferable. The sub-tank has a function of improving a damper effect and refill that prevents fluctuations in the internal pressure of the head.

  Further, the inkjet recording apparatus 10 is provided with a cap 64 as a means for preventing the nozzle 51 from drying or preventing an increase in ink viscosity near the nozzle, and a maintenance blade 66 as a means for cleaning the ink discharge surface of the head 50. Yes.

  The maintenance unit including the cap 64 and the maintenance blade 66 can be moved relative to the head 50 by a moving mechanism (not shown), and is moved from a predetermined retracted position to a maintenance position below the head 50 as necessary.

  The cap 64 is displaced up and down relatively with respect to the head 50 by an elevator mechanism (not shown). The cap 64 is raised to a predetermined raised position when the power is turned off or during printing standby, and is brought into close contact with the head 50, thereby covering the nozzle surface with the cap 64.

  During printing or standby, if the frequency of use of a specific nozzle 51 is reduced and ink is not ejected for a certain period of time, the ink solvent near the nozzle evaporates and the ink viscosity increases. In such a state, ink cannot be ejected from the nozzle 51 even if the piezoelectric element 58 operates.

  Before such a state is reached (within the range of viscosity that can be discharged by the operation of the piezoelectric element 58), the piezoelectric element 58 is operated, and a cap is formed to discharge the deteriorated ink (ink in the vicinity of the nozzle whose viscosity has increased). Preliminary ejection (purge, idle ejection, collar ejection, dummy ejection) is performed toward 64 (ink receiver).

  A mode in which preliminary ejection is performed by ejecting ink toward the intermediate transfer belt 12 is also possible. For example, when a plurality of images are continuously formed, preliminary ejection can be performed between images. In particular, when a plurality of identical images are formed, the frequency of ink (treatment liquid) ejection at a specific nozzle is low, and the possibility of abnormal ejection increases. Preliminary ejection between images for the specific nozzle It is preferable to carry out.

  When preliminary discharge is performed on the intermediate transfer belt 12, the member is separated from the image surface of the intermediate transfer belt 12 so that ink by preliminary discharge does not adhere to a member disposed on the image surface side such as the transfer roller 24C. A predetermined clearance (for example, about 10 mm) may be provided between the solvent removal roller or transfer roller 24C and the intermediate transfer belt 12.

  Further, when air bubbles are mixed into the ink in the head 50 (in the pressure chamber 52), the ink cannot be ejected from the nozzle even if the piezoelectric element 58 is operated. In such a case, the cap 64 is applied to the head 50, the ink in the pressure chamber 52 (ink mixed with bubbles) is removed by suction with the suction pump 67, and the suctioned and removed ink is sent to the recovery tank 68.

  In this suction operation, the deteriorated ink with increased viscosity (solidified) is sucked out when the ink is initially loaded into the head or when the ink is used after being stopped for a long time. Since the suction operation is performed on the entire ink in the pressure chamber 52, the amount of ink consumption increases. Therefore, it is preferable to perform preliminary ejection when the increase in ink viscosity is small.

  The maintenance blade 66 is made of an elastic member such as rubber, and can slide on the ink discharge surface of the head 50 by a blade moving mechanism (not shown). When ink droplets or foreign matter adhere to the ink discharge surface, the maintenance blade 66 is slid on the ink discharge surface to wipe the ink discharge surface and clean the ink discharge surface.

<Description of control system>
FIG. 7 is a principal block diagram showing the system configuration of the inkjet recording apparatus 10. The inkjet recording apparatus 10 includes a communication interface 70, a system controller 72, a memory 74, a motor driver 76, a heater driver 78, a transfer recording control unit 79, a print control unit 80, a treatment liquid application control unit 81, an image buffer memory 82, and a head driver. 84 and the like.

  The communication interface 70 is an interface unit that receives image data sent from the host computer 86. As the communication interface 70, a serial interface such as USB (Universal Serial Bus), IEEE 1394, Ethernet (registered trademark), a wireless network, or a parallel interface such as Centronics can be applied. In this part, a buffer memory (not shown) for speeding up communication may be mounted. The image data sent from the host computer 86 is taken into the inkjet recording apparatus 10 via the communication interface 70 and temporarily stored in the memory 74.

  The memory 74 is a storage unit that temporarily stores an image input via the communication interface 70, and data is read and written through the system controller 72. The memory 74 is not limited to a memory made of a semiconductor element, and a magnetic medium such as a hard disk may be used.

  The system controller 72 includes a central processing unit (CPU) and its peripheral circuits, and functions as a control device that controls the entire inkjet recording apparatus 10 according to a predetermined program, and also functions as an arithmetic device that performs various calculations. . That is, the system controller 72 controls each part such as the communication interface 70, the memory 74, the motor driver 76, the heater driver 78, etc., performs communication control with the host computer 86, read / write control of the memory 74, etc. A control signal for controlling the motor 88 and the heater 89 is generated.

  The memory 74 stores programs executed by the CPU of the system controller 72 and various data necessary for control. Note that the memory 74 may be a non-rewritable storage means or a rewritable storage means such as an EEPROM. The memory 74 is used as a temporary storage area for image data, and is also used as a program development area and a calculation work area for the CPU.

  The motor driver 76 is a driver that drives the motor 88 in accordance with instructions from the system controller 72. In FIG. 7, the motor (actuator) arranged in each part in the apparatus is represented by reference numeral 88. For example, the motor 88 shown in FIG. 7 includes a motor for driving the drive roller of the rollers 28A and 28B in FIG. 1, a motor for the solvent removal roller moving mechanism, a motor for the transfer roller 24C moving mechanism, and a maintenance blade 66. The motor of the moving mechanism, the motor of the moving mechanism of the cleaning liquid supply unit 16C, and the like are included.

  The heater driver 78 is a driver that drives the heater 89 in accordance with an instruction from the system controller 72. In FIG. 7, a plurality of heaters provided in the ink jet recording apparatus 10 are represented by reference numeral 89. For example, the heater 89 shown in FIG. 7 includes the infrared heater of the drying processing unit 20 shown in FIG. 1, the heater of the preheating unit, the heater of the fixing unit, the heater of the heating device 232 shown in FIG. Yes.

  The transfer recording control unit 79 performs pressure control of the transfer roller 24C of the transfer recording unit 24 and temperature control of the heater 24A. For each type of recording medium 14 and each type of ink, the optimum pressing value of the transfer roller 24C and the optimum temperature value of the heater 24A are obtained in advance, stored in a predetermined memory (for example, the memory 74) and recorded in a data table. When the information on the medium 14 and the information on the ink used are acquired, the pressure of the transfer roller 24C and the heating temperature of the heater 24A are controlled with reference to the memory.

  The print control unit 80 has a signal processing function for performing various processes and corrections for generating a print control signal from the image data in the memory 74 in accordance with the control of the system controller 72. The generated print data This is a control unit that supplies (dot data) to the head driver 84. Necessary signal processing is performed in the print controller 80, and the ejection amount and ejection timing of the ink droplets of the head 50 are controlled via the head driver 84 based on the image data. Thereby, a desired dot size and dot arrangement are realized.

  The print control unit 80 includes an image buffer memory 82, and image data, parameters, and other data are temporarily stored in the image buffer memory 82 when image data is processed in the print control unit 80. Also possible is an aspect in which the print controller 80 and the system controller 72 are integrated and configured with one processor.

  The treatment liquid application control unit 81 controls the application amount and application region of the treatment liquid in the treatment liquid application unit 18 shown in FIG. For example, in the aspect in which the processing liquid is applied to the intermediate transfer belt 12 using the application roller, the image processing apparatus includes a unit that detects the position of the image area in the conveyance path of the intermediate transfer belt 12. The application of the treatment liquid is started at the timing of entering, and the application of the treatment liquid is finished at the timing of the image area leaving the treatment area of the treatment liquid application unit 18. When the total amount of ink used for the image is determined according to the image data, and the total amount of ink is relatively large, the treatment liquid application amount is relatively increased, and the total amount of ink is relatively small The amount of treatment liquid applied is controlled so as to relatively reduce the amount of treatment liquid application.

  The head driver 84 generates a drive signal to be applied to the piezoelectric element 58 of the head 50 based on the image data given from the print control unit 80, and drives the piezoelectric element 58 by applying the drive signal to the piezoelectric element 58. Including a driving circuit. Note that the head driver 84 shown in FIG. 7 may include a feedback control system for keeping the driving condition of the head 50 constant.

  Data of an image to be printed is input from the outside via the communication interface 70 and stored in the memory 74. At this stage, RGB image data is stored in the memory 74.

  The image data stored in the memory 74 is sent to the print controller 80 via the system controller 72, and is converted into dot data for each ink color by the print controller 80. That is, the print control unit 80 performs processing for converting the input RGB image data into dot data of four colors of KCMY. The dot data generated by the print controller 80 is stored in the image buffer memory 82.

  Note that the primary image formed on the intermediate transfer belt 12 must be a mirror image of the main image finally formed on the recording medium 14 in consideration of inversion at the time of transfer. That is, the drive signal supplied to the ink heads 22Y, 22M, 22C, and 22K is a drive signal corresponding to the mirror image, and the print control unit 80 needs to invert the input image.

  Various control programs are stored in the program storage unit 90, and the control programs are read and executed in accordance with instructions from the system controller 72. The program storage unit 90 may use a semiconductor memory such as a ROM or an EEPROM, or may use a magnetic disk or the like. An external interface may be provided and a memory card or PC card may be used. Of course, you may provide several recording media among these recording media. The program storage unit 90 may also be used as a storage unit (not shown) for operating parameters and the like.

  In FIG. 7, a plurality of sensors provided in the inkjet recording apparatus 10 are represented by reference numeral 92 as a representative. The sensor 92 includes a recording medium detection sensor 38 that detects the recording medium 14 shown in FIG. 1, a sensor that detects the position of the intermediate transfer belt 12 on the conveyance path (shown by reference numerals 402 and 404 in FIG. 22), and the recording medium 14. A sensor for detecting the type of the recording medium, a sensor used for aligning the recording medium 14 and the primary image in the transfer recording unit 24 (a sensor for detecting the position of the recording medium 14, the position of the intermediate transfer belt 12 (primary image)) Sensor), drying processing unit 20, transfer recording unit 24, temperature sensor of preheating unit, and the like.

  In addition, it is also preferable to provide an embodiment in which a remaining amount sensor for the cleaning liquid tank 36 shown in FIG.

  The system controller 72 includes the image area determination unit 40 shown in FIG. 1 as a functional block. When the detection signal of the recording medium 14 is sent from the recording medium detection sensor 38 in FIG. 1 (the sensor 92 in FIG. 7) to the image area determination unit 40, the image area determination unit 40 determines the cleaning process target area based on the detection signal. It is determined whether the area is an image area or a non-image area, and a command signal corresponding to the determination result is sent to the cleaning liquid flow rate controller 42. The cleaning liquid flow rate control unit 42 controls the supply amount of the cleaning liquid supplied from the cleaning liquid supply unit 16C based on the command signal.

  Note that, among the functional blocks illustrated in FIG. 7, a plurality of functional blocks may be configured by a common device (processor). It is also possible to configure a part of a certain functional block and a part of another functional block with a common device. For example, the system controller 72 and the print controller 80 may be configured by a common processor, or the memory 74 associated with the system controller 72 and the image buffer memory 82 associated with the print controller 80 may be shared by a common memory device. You may comprise.

<Description of Cleaning Processing Unit>
Next, the configuration of the cleaning processing unit 16 shown in FIG. 1 and the cleaning processing of the intermediate transfer belt 12 will be described in detail.

  As described above, in the cleaning process of the intermediate transfer belt 12 shown in this example, when the image area (the area where the remaining amount of ink is smaller than the non-image area) is cleaned, the non-image area is cleaned. Also, the supply amount of the cleaning liquid is controlled so as to reduce the supply amount of the cleaning liquid.

  Here, the “image area” includes an area where a primary image is formed, and includes an area where the recording medium 14 contacts and a margin in the width direction of the intermediate transfer belt 12 in the area. That is, most of the ink adhering to the image area is transferred to the recording medium, so that almost no ink remains in the image area after transfer recording. On the other hand, the “non-image area” is an area that does not come into contact with the recording medium 14 except for the image area. In the non-image area after transfer recording, dried processing liquid (that does not react with ink) or agglomerated ink (spattering). Or a droplet ejected near the outer edge of the recording medium) remains as it is. The “image area” and “non-image area” are illustrated in FIG.

FIG. 8 schematically illustrates a state when the image area is cleaned, and FIG. 9 schematically illustrates a state when the non-image area is cleaned. For example, when the intermediate transfer belt 12 having a width of 300 mm is used, the supply amount of the cleaning liquid at the time of cleaning the image area shown in FIG. 8 is 6 to 16 (cc / m ² ), and the non-image area shown in FIG. An example in which the supply amount of the cleaning liquid at the time of cleaning is 65 to 100 (cc / m ² ) is given. That is, the supply amount of the cleaning liquid at the time of cleaning the image area is preferably 9% to 16% of the supply amount of the cleaning liquid at the time of cleaning the non-image area.

  The cleaning liquid supply time is set based on the length of the recording medium 14 in the direction corresponding to the intermediate transfer belt conveyance direction and the conveyance speed of the intermediate transfer belt 12. In the above example, the conveyance speed of the intermediate transfer belt 12 is 500 (mm / s), and in the case of printing in the A4 vertical direction, the cleaning liquid supply time is approximately 0.6 (sec). However, it is preferable to set 0.7 to 0.8 (sec) in consideration of the margin.

  FIG. 10 illustrates a configuration example of the image area 100 and the non-image area 102. The intermediate transfer belt 12 applied to this example is provided with a plurality of image areas 100 on which primary images are formed at predetermined arrangement intervals. In the intermediate transfer belt 12 shown in FIG. 10, a non-image area 102-1 is provided between the first image area 100-1 and the second image area 100-2. In this manner, the image area 100 and the non-image area are alternately arranged on the image surface of the intermediate transfer belt 12 such as the image area 100, the non-image area 102, the image area 100,. As shown in FIG. 10, the length of the image area 100 in the intermediate transfer belt conveyance direction is 100A, and the length of the non-image area 102 in the intermediate transfer belt conveyance direction is 102A.

  In this example, the size of the non-image area 102 is constant (the length 102A of the non-image area 102 in the intermediate transfer belt conveyance direction and the length in the width direction are constant), and the length of the image area 100 in the intermediate transfer belt conveyance direction. Is appropriately determined according to the size of the recording medium 14 to be used, and the length in the width direction of the intermediate transfer belt 12 in the image area 100 is constant regardless of the size of the recording medium 14 (the intermediate transfer belt 12 in the image area 100). The length in the width direction is the width of the drawing area of the head 50 (the width corresponding to borderless printing) and the width of the recording medium 14 whichever is greater).

  That is, as shown in FIG. 10, the intermediate transfer belt 12 is provided with non-image areas 102 at both ends in the width direction. By applying such a configuration, problems due to the meandering of the belt and the backside of the cleaning liquid are prevented.

  Note that the length 100A of the image area 100 in the intermediate transfer belt conveyance direction is a length in a direction corresponding to the intermediate transfer belt conveyance direction of the recording medium 14 in consideration of a positional deviation between the intermediate transfer belt 12 and the recording medium 14 and the like. It is better to increase it by about 5% to 10%. Further, the image area 100 may be set corresponding to the maximum size recording medium 14 that can be used, and the size 100A of the image area 100 may be a fixed value, or the length of the non-image area 102 in the intermediate transfer belt conveyance direction may be set. It may be changed as appropriate according to the size of the recording medium 14 (when the size of the recording medium 14 is relatively small, the interval between the image areas 100 is shortened).

  Next, a specific example of changing the supply amount of the cleaning liquid supplied from the cleaning liquid supply unit 16C will be described.

In the apparatus configuration of FIG. 1, a rotary pump is applied to the pump 32, and the supply amount of the cleaning liquid can be controlled by the number of rotations of the pump 32 that supplies the cleaning liquid to the cleaning liquid supply unit 16C. As described above, when the intermediate transfer belt 12 having a width of 300 mm is used as a cleaning liquid control example, the cleaning liquid supply amount when cleaning the image area 100 (see FIG. 8) is 6 to 16 (cc). / ^{m 2)} and then, examples of the supply amount of the cleaning liquid during cleaning of the non-image area (see FIG. 9) and 65 to 100 (cc / ^{m 2)} and the like.

  Further, since the supply amount of the cleaning liquid is proportional to the pressure applied to the cleaning liquid supply unit 16C, the pressure of the pump 32 provided in the cleaning liquid supply path 34 communicating with the cleaning liquid supply unit 16C is changed. By doing so, the supply amount of the cleaning liquid can be changed.

  As shown in FIG. 11, a pressure sensor 110 that detects the pressure in the cleaning liquid tank 36 that communicates with the cleaning liquid supply unit 16C, and a pressure control unit that controls the pump 32 based on a pressure detection signal obtained from the pressure sensor 110. 112, and calculating a difference between a detected pressure value in the cleaning liquid tank 36 and a known pressure value, and changing a flow rate of a pump that sends air into the cleaning liquid tank 36, thereby providing a cleaning liquid supply unit. The pressure applied to 16C is changed.

  That is, in this example, the pressure control unit 112 is configured to perform feedback control based on the detection value of the pressure sensor 110. For example, the relationship between the pressure detection value and the supply amount of the cleaning liquid is obtained in advance by an experiment or the like, and the difference between the pressure detection value with respect to the target cleaning liquid supply amount and the actual pressure detection value is used as a pressure adjustment value. Can be mentioned.

  More specifically, the relationship between the pressure detection value and the supply amount of the cleaning liquid is stored in a database, and when the image area 100 is cleaned, the image area 100 (or non-image area 102) is stored from the database. The pressure value corresponding to the cleaning is read, a difference (pressure adjustment value) from the detection value of the pressure sensor 110 is obtained, and the flow rate (rotation speed) of the pump 32 is appropriately changed.

  Note that the pressure control unit 112 illustrated in FIG. 11 is a functional block included in the control system illustrated in FIG. 7. The mode shown in FIG. 11 is characterized in that the response of the pressure change to the control signal is good and the error in the supply amount is small, which is a preferable configuration when the supply amount of the cleaning liquid is finely changed.

  As shown in FIG. 12, it is also preferable to change the quantity of the cleaning liquid supply unit 16C. In the embodiment shown in the figure, when a plurality of (three) cleaning liquid supply units 16C are provided, the cleaning liquid supply amount of each cleaning liquid supply unit 16C is constant, and the cleaning liquid supply amount is increased, the cleaning liquid is supplied. The number of cleaning liquid supply units 16C to be supplied may be increased.

  In the embodiment shown in FIG. 12, the cleaning liquid supply passage 34 communicating with each cleaning liquid supply unit 16 </ b> C includes the electromagnetic valve 120, and each cleaning liquid supply unit 16 </ b> C can be turned on and off by opening and closing the electromagnetic valve 120. In this example, the electromagnetic valve is exemplified as the selection unit for the plurality of cleaning liquid supply units 16C. However, the cleaning liquid supply path 34 that communicates with each cleaning liquid supply unit 16C can be selectively opened and closed. Other configurations are applicable. The embodiment shown in FIG. 12 is a more preferable embodiment when the variation in the cleaning liquid injection amount is large.

  In addition, the configuration example shown in FIG. 12 is suitable when a plurality of types of cleaning liquids are used by switching the cleaning liquid supply units 16C with different cleaning liquids, or when a plurality of types of cleaning liquids are used in combination. It is a configuration.

  Here, an example of the composition of the cleaning liquid applied to this example will be shown.

Glycerin 20w%
Diethylene glycol 10w%
Olfin 1w%
The remaining amount of pure water The cleaning processing unit 16 needs to remove the components of the processing liquid and ink described above and return the intermediate transfer belt 12 to the initial state. Is preferred. The above-described cleaning liquid can be appropriately changed according to the type of ink and processing liquid.

According to the inkjet recording apparatus 10 configured as described above, cleaning of the image area 100 with a relatively small amount of ink or the like is supplied with a small amount of cleaning liquid, and a non-image with a relatively large amount of ink or the like is deposited. Since the cleaning of the region 102 is configured to supply a large amount of cleaning liquid, foreign matters such as ink adhering to the cleaning blade 16A can be easily slid (removed) from the cleaning blade 16A, and the image region 100 is cleaned. In this case, the amount of the cleaning liquid is minimized, the consumption of the cleaning liquid can be suppressed, and the waste liquid can be minimized. Further, since the cleaning blade 16A can be cleaned while the cleaning blade 16A is in contact with the intermediate transfer belt 12, the cleaning blade 16A can be cleaned even during the recording operation, and the cleaning blade 16A can be removed from the intermediate transfer belt 12. It is possible to prevent liquid remaining on the intermediate transfer belt 12 that occurs when the spacers are separated.
[Second Embodiment]
Next, a second embodiment according to the present invention will be described. FIG. 13 illustrates a schematic configuration of the cleaning processing unit 216 of the inkjet recording apparatus 200 according to the second embodiment. Note that, in the second embodiment, the same or similar parts as those of the first embodiment described above are denoted by the same reference numerals, and the description thereof is omitted.

  The cleaning processing unit 216 shown in FIG. 13 includes a first cleaning liquid supply unit 202 and a second cleaning liquid supply unit 204, and the first cleaning liquid supply unit 202 and the second cleaning liquid supply unit 204. The cleaning liquids having different properties are ejected from each.

  That is, the first cleaning liquid supply unit 202 communicates with the first cleaning liquid tank 212 in which the first cleaning liquid 210 is accommodated via the first cleaning liquid supply path 206 and the first pump 208. The second cleaning liquid supply unit 204 communicates with the second cleaning liquid tank 222 in which the second cleaning liquid 220 is accommodated via the second cleaning liquid supply path 217 and the second pump 218.

  In the cleaning process of this example, only the first cleaning liquid 210 is used for cleaning the image area (shown by reference numeral 100 in FIG. 10), and the first cleaning liquid 210 is used for cleaning the non-image area (shown by reference numeral 102 in FIG. 10). Two cleaning liquids 220 are used. As in the first embodiment, the supply amount of the second cleaning liquid 220 is about 5 to about 10 times the supply amount of the first cleaning liquid 210 (the first cleaning liquid with respect to the second cleaning liquid supply amount). The liquid supply amount is preferably 9% to 16%. In the cleaning of the non-image area, the first cleaning liquid 210 and the second cleaning liquid 220 may be used in combination.

  In this example, a surfactant aqueous solution such as olfine is applied as the first cleaning liquid 210, and examples thereof include an olphine aqueous solution. For the second cleaning liquid 220, an aqueous solution having a lower surfactant concentration than the first cleaning liquid 210 or an aqueous solution not containing a surfactant is used.

  Specific examples of the aqueous solution having a low surfactant concentration include an aqueous solution having a surfactant concentration of 0.1 wt% or less when the surfactant concentration of the first cleaning liquid is 1 to 5 wt%. Moreover, a pure water is mentioned as a specific example of the aqueous solution which does not contain surfactant.

  In the cleaning of the image area, the main purpose is to move dirt such as ink and foreign matters attached to the intermediate transfer belt 12 to the cleaning blade 16A. Therefore, an aqueous liquid containing a surfactant is preferable. However, the surfactant easily adheres to the cleaning blade 16A, and the concentration of the surfactant on the cleaning blade 16A increases by performing cleaning for a long time, and the intermediate portion of the cleaning blade 16A on the downstream side in the conveyance direction of the intermediate transfer belt. Surfactant bubbles are generated on the transfer belt 12. If the bubbles of the surfactant pass through the cleaning blade 16A without disappearing and reach the processing area of the process after the processing liquid coating unit 18, there is a possibility that an image defect due to the bubbles may occur.

  In the cleaning process shown in this example, the interface on the cleaning blade 16A is supplied by supplying the second cleaning liquid 220 having a low surfactant concentration (or no surfactant) to the non-image area. There is an effect of reducing the concentration of the active agent and suppressing the generation of bubbles.

  On the other hand, it is preferable that the first cleaning liquid 210 easily adheres to the surface of the intermediate transfer belt 12 and does not slide down immediately after adhering to the cleaning blade 16A, and maintains a constant liquid amount on the cleaning blade 16A. . Further, by holding the first cleaning liquid 210 on the cleaning blade 16A, convection of the first cleaning liquid 210 occurs on the cleaning blade 16A, and it becomes possible to reliably remove dirt.

  It should be noted that by holding the first cleaning liquid 210 on the cleaning blade 16A, the intermediate transfer belt 12 is uniformly cleaned even when the amount of spray liquid (supply amount) of the first cleaning liquid 210 varies. be able to.

  However, when removing dirt adhering to the cleaning blade 16A, the first cleaning liquid 210 and the second cleaning liquid 220 adhering to the cleaning blade 16A should be easily slid, and the liquid has a low viscosity. It is preferable. Therefore, in the cleaning of the image area, the first cleaning liquid 210 containing a high-viscosity liquid component such as glycerin is used to facilitate the holding of the first cleaning liquid 210 on the cleaning blade 16A, and in the cleaning of the non-image area. Using the second cleaning liquid 220 containing more low-viscosity liquid components such as pure water, the first cleaning liquid 210 and the second cleaning liquid 220 adhering to the cleaning blade 16A are slid down from the cleaning blade 16A. It is preferable to make it easy.

  In this example, it is preferable that the “low viscosity liquid component” of the second cleaning liquid 220 has a viscosity equal to or lower than the viscosity of the ink used for recording. For example, when the viscosity of the recording ink is 5 cP, the viscosity of the low-viscosity liquid component is preferably 1 cP or more and 5 cP or less.

  On the other hand, the first cleaning liquid 210 “high-viscosity liquid component” is also affected by the material of the intermediate transfer belt 12 and the shape of the surface. Therefore, it is preferable to determine the viscosity range by a sample test or the like. If the viscosity of the high-viscosity liquid component is too large, the high-viscosity liquid component does not slide off the cleaning blade 16A even if the low-viscosity liquid component is jetted, and the high-viscosity liquid component remains on the intermediate transfer belt 12 or the cleaning blade 16A. For this reason, it varies depending on the material of the low viscosity liquid component. That is, the viscosity of the high viscosity liquid component may be determined according to the low viscosity liquid component. For example, when fluorine rubber is applied to the cleaning blade 16A and silicon rubber is applied to the surface of the intermediate transfer belt 12, and pure water is used as the low-viscosity liquid component (second cleaning liquid 220), the high-viscosity liquid component (first The viscosity of the cleaning liquid 210) is preferably 5 cP or more and 20 cP or less.

  Further, since the viscosity of the first cleaning liquid 210 and the second cleaning liquid 220 also changes depending on the temperature, it is possible to adjust the viscosity range by decreasing the viscosity by heating and increasing the viscosity by cooling.

  FIG. 14 illustrates an example of a configuration for changing the viscosity of the first cleaning liquid 210 and the second cleaning liquid 220. 14 includes a cooling device 230 in the first cleaning liquid supply path 206 that communicates with the first cleaning liquid supply section 202 and a second cleaning liquid supply section 204 that communicates with the second cleaning liquid supply section 204. A heating device 232 is provided in the second cleaning liquid supply path 217.

  In the configuration shown in FIG. 14, the same liquid can be used for the first cleaning liquid 210 and the second cleaning liquid 220. For example, as shown in FIG. 14, the first cleaning liquid tank 212 and the second cleaning liquid tank 222 are made common, and the cleaning liquid supply flow path is branched into two from the common cleaning liquid tank 212 ′. It is possible to make liquids having different viscosities by heating or cooling in the middle of the flow path.

  According to the second embodiment configured as described above, two kinds of cleaning liquids (the first cleaning liquid 210 and the second cleaning liquid 220) are provided, and the viscosity of the image area cleaning process is relatively high. The first cleaning liquid 210 is applied to move the adhering portion attached to the intermediate transfer belt 12 to the cleaning blade 16A, and the second cleaning liquid 220 having a relatively low viscosity is used for the cleaning process of the non-image area. Further, since the amount of the second cleaning liquid 220 supplied is larger than the amount of the first cleaning liquid 210 supplied, the adhering matter adhering to the cleaning blade 16A is removed, and therefore the adhering matter on the intermediate transfer belt 12 is removed. Is suitably removed, and the deposits on the cleaning blade 16A can also be suitably removed.

  When the first cleaning liquid 210 contains a surfactant, the second cleaning liquid is used to reduce the concentration of the surfactant on the cleaning blade 16A and suppress the generation of bubbles. be able to. Furthermore, by using the first cleaning liquid 210 and the second cleaning liquid 220 in common, the configuration of the apparatus (cleaning processing unit 216 ′) can be reduced in size, and the cost can be reduced.

  In this example, a configuration example using two types of cleaning liquids is shown, but three or more types of cleaning liquids can be selectively used selectively.

[Third Embodiment]
Next, a third embodiment according to the present invention will be described. In addition, the same code | symbol is attached | subjected to the part which is the same as that of 1st, 2nd embodiment demonstrated previously in 3rd Embodiment, or similar, and the description is abbreviate | omitted.

  In the third embodiment, the elapsed time after the recording operation (a series of processes from primary image formation to transfer recording) is measured, and if the next recording operation is not started even after a specified time has elapsed. Then, a cleaning operation with a large amount of liquid (cleaning process applied to a non-image area) is performed while the intermediate transfer belt 12 is conveyed in a predetermined conveyance direction. The “cleaning with a large amount of liquid” may be performed during a part of the entire cleaning operation. For example, when the specified time is 10 minutes and the entire cleaning operation time is 1 minute, the cleaning time with a large amount of liquid is 10 seconds.

  For example, when a print job is executed continuously, the same condition as the non-image area cleaning process is executed when the next print job is executed when a predetermined time has elapsed since the end of the previous print job. Then, the intermediate transfer belt 12 is cleaned, and then the next print job is started.

  In the same print job, if an interrupt of processing other than printing occurs after the previous recording operation and the print job is paused, when the print job is resumed, an intermediate is performed under the same conditions as the non-image area cleaning processing. The transfer belt 12 is cleaned, and then the next recording operation is started.

  If the cleaning blade 16A is left with foreign matter such as ink attached, the water on the cleaning blade 16A evaporates and the ink and foreign matter thicken or solidify, and even if the amount of cleaning liquid increases, it adheres to the cleaning blade 16A. It becomes difficult to remove the adhered matter. Therefore, the deposits are removed from the cleaning blade 16A before it becomes difficult to remove the deposits on the cleaning blade 16A, and the cleaning failure of the intermediate transfer belt 12 due to the deposits on the cleaning blade 16A is prevented.

  Further, when the time interval between the printing operation and the next printing operation is long as in the quiet processing, the intermediate transfer belt 12 with relatively little dirt can be obtained by performing the cleaning processing of the intermediate transfer belt 12 every time the recording operation is completed. The belt 12 is cleaned under the same conditions as when there is a lot of dirt, and an excessive amount of cleaning liquid is consumed.

  FIG. 15 shows a flowchart of an image recording process and a cleaning process applied to the third embodiment. As shown in FIG. 15, the recording process is started (step S10), a series of recording operation processes from primary image formation to transfer recording are executed (step S11), and the image recording process is ended (step S12). ). Thereafter, the process proceeds to step S14, and the elapsed time from the end of the image recording process is measured. The means for measuring the elapsed time includes a sensor for detecting that the recording medium 14 (see FIG. 1) has left the transfer recording unit 24, a timer (counter) for measuring the elapsed time from the detection timing of the sensor, A configuration including the above can be applied.

  Specifically, the rear end portion of the recording medium 14 is detected by the recording medium detection sensor 38 in FIG. 1, and the control system shown in FIG. 7 is performed using the rear end detection signal of the recording medium 14 by the recording medium detection sensor 38 as a trigger signal. The aspect which measures elapsed time with the counter with which is equipped with is mentioned.

  In step S16, the elapsed time from the end of the recording operation (count value of the counter) is a predetermined time (the evaporation of moisture on the cleaning blade 16A is small, and deposits on the cleaning blade 16A can be removed by the cleaning operation). If the elapsed time does not exceed the specified time (NO determination), whether there is an instruction to start the next recording operation or not Is determined (step S18). If the next recording operation start command is acquired in step S18 (YES determination), the recording operation based on the next image data is executed, and then the process proceeds to step S11. On the other hand, in step S18, when the next recording operation start command has not been acquired (when an interval of a quiet process or an interruption of another process occurs) (NO determination), the elapsed time is measured. Continue (step S16).

In step S16, when the elapsed time exceeds the specified time (YES determination), the cleaning process of the intermediate transfer belt 12 is executed based on the condition that the amount of the cleaning liquid is large (cleaning condition for the non-image area). (Step S20). When the cleaning process of the intermediate transfer belt 12 is started, the elapsed time from the start of cleaning is measured and it is determined whether or not the elapsed time exceeds a predetermined cleaning time (step S22). That is, the cleaning process is managed by the elapsed time from the start.
In step S22, when the elapsed time does not exceed the predetermined cleaning time (NO determination), the process proceeds to step S24, and it is determined whether or not the next recording operation start command is acquired. In step S24, when the next recording operation start command is acquired (YES determination), the cleaning operation is stopped (step S25), and the process proceeds to step S11.

  On the other hand, if the elapsed time exceeds the predetermined cleaning time in step S22 (YES determination), the cleaning operation (process) is terminated and parameters related to the cleaning operation are reset (step S26). The recording operation start command acquisition standby state is entered (step S28).

  According to the third embodiment configured as described above, when the image recording process is continuously performed, the cleaning process condition of the intermediate transfer belt 12 is changed based on the elapsed time from the end of the previous recording operation. Therefore, an appropriate cleaning process is always executed, and the intermediate transfer belt 12 before the image recording process is maintained in a preferable state.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described. In the fourth embodiment, the same or similar parts as those in the first to third embodiments are denoted by the same reference numerals, and the description thereof is omitted.

  In the fourth embodiment of the present invention, when the cleaning process target area is determined to be an image area, the cleaning liquid is supplied to the surface of the intermediate transfer belt 12 in an area where the cleaning blade 16A and the intermediate transfer belt 12 are not in contact with each other. Thereafter, the cleaning liquid is supplied to an area where the cleaning blade 16A and the intermediate transfer belt 12 are in contact with each other by the relative movement of the intermediate transfer belt 12 and the cleaning blade 16A, and the cleaning target area is an image area. If not, the cleaning liquid is supplied to at least the area where the intermediate transfer belt 12 and the cleaning blade 16A are in contact with each other. A plurality of cleaning liquid supply units 16C may be provided.

  That is, a moving mechanism for moving the cleaning liquid supply unit 16C corresponding to (in parallel with) the conveyance direction of the intermediate transfer belt is provided, and when the image area is to be cleaned, the cleaning liquid supply position by the cleaning liquid supply unit 16C is set to the intermediate position. A predetermined position (hereinafter referred to as “image area supply position”) that is separated from the contact position between the transfer belt 12 and the cleaning blade 16A (hereinafter referred to as “blade position”) on the upstream side in the conveyance direction of the intermediate transfer belt. When the non-image area is to be cleaned, the cleaning liquid supply position by the cleaning liquid supply unit 16C is moved from the image area supply position to the blade position, and at least the cleaning liquid is supplied to the blade position. It is configured.

  FIG. 16 illustrates a state in which the cleaning process is performed on the image area (indicated by reference numeral 100 in FIG. 10). As shown in the figure, when it is determined that the next area to be cleaned is an image area, the cleaning liquid 16 </ b> B is supplied to the image area supply position 302. The distance between the image area supply position 302 and the blade position 300 is appropriately set according to the conveyance speed of the intermediate transfer belt 12 and the time until the deposit on the intermediate transfer belt 12 is dissolved (dispersed) in the cleaning liquid.

  When removing ink or the like remaining on the intermediate transfer belt 12, it may not be completely removed if it is wiped within a short time after applying the cleaning liquid. For example, when a resin polymer is contained in the ink, the resin polymer dissolves (disperses) in the cleaning liquid at a slow rate. Therefore, if the ink is wiped within a short time after the cleaning liquid is applied, the ink is transferred to the intermediate transfer belt. As shown in FIG. 16, the cleaning liquid is supplied to an area away from the blade position 300, and the intermediate transfer belt 12 is conveyed from the image area supply position 302 to the blade position 300. In the meantime, the resin polymer is dissolved (dispersed) in the cleaning liquid, and then the intermediate transfer belt 12 is wiped by the cleaning blade 16A, so that the deposits attached to the intermediate transfer belt 12 can be reliably removed.

  Further, there is an advantage that mist generated at the time of ejection in the image area can be prevented from moving to the downstream side of the cleaning blade 16A and adhering to the intermediate transfer belt 12. In other words, in the cleaning of the image area, a small amount of cleaning liquid is supplied to the image area supply position 302 that is away from the blade position 300, so that the cleaning liquid is prevented from flowing around the blade position 300 downstream in the intermediate transfer belt conveyance direction. The

  On the other hand, when it is determined that the next area to be cleaned is a non-image area (indicated by reference numeral 102 in FIG. 10), as shown in FIG. The cleaning liquid supply unit 16 </ b> C is moved directly below) to supply at least the blade position 300 with the cleaning liquid.

  As shown in FIG. 16, when a large amount of cleaning liquid (with a cleaning liquid amount in the non-image area) is supplied at a position away from the cleaning blade 16A, the surface tension of the cleaning blade 16A does not work and droplets are removed from the intermediate transfer belt 12. Since the problem of easy sliding or dripping occurs, in the non-image-shaped region cleaning process using a large amount of cleaning liquid, at least the blade position 300 is supplied with the cleaning liquid, and in the non-image region, from the intermediate transfer belt 12. It is possible to remove ink and foreign matter adhering to the cleaning blade 16A without causing the cleaning liquid to slide off.

  Further, in the cleaning process of the non-image area, the jetting pressure is applied by directly spraying the cleaning liquid onto the cleaning blade 16A, and it becomes possible to more reliably remove the ink and foreign matters attached to the cleaning blade 16A. It should be noted that the cleaning liquid may be continuously supplied from the image area supply position 302 to the blade position 300 when switching from the image area cleaning process to the non-image area cleaning process.

  Here, as an example of the moving mechanism of the cleaning liquid supply unit 16C in the embodiment shown in FIGS. 16 and 17, a support member that supports the cleaning liquid supply unit 16C and a ball that moves the support member in a predetermined moving direction. Examples include a configuration including a linear motion mechanism such as a screw and a motor that is a drive source of the linear motion mechanism.

  In this example, the mode in which the cleaning liquid supply unit 16C is moved in the direction parallel to the intermediate transfer belt conveyance direction is illustrated, but a mode in which the cleaning liquid supply unit 16C is moved in the horizontal direction is also possible. In such an aspect, the cleaning liquid injection distance changes with the movement of the cleaning liquid supply unit 16C, so the supply pressure may be changed according to the cleaning liquid supply distance. For example, the supply pressure is decreased when the supply distance is short, and the supply pressure is increased when the supply distance is long.

  FIG. 18 shows another aspect of the moving mechanism of the cleaning liquid supply unit 16C. In the aspect shown in FIG. 18, the cleaning liquid supply unit 16 </ b> C is configured to be capable of swinging with respect to the surface including the image area of the intermediate transfer belt 12. That is, the cleaning liquid supply unit 16C shown in FIG. 18 is orthogonal to the conveyance direction of the intermediate transfer belt and parallel to a plane including the image area (non-image area) of the intermediate transfer belt 12 (in FIG. 18, a direction perpendicular to the paper surface). The cleaning liquid supply position can be changed by performing a swinging motion.

  A state indicated by a one-dot broken line in FIG. 18 is a state in which the cleaning process of the image region is executed, and the cleaning liquid is supplied to the image region supply position 302 that is away from the blade position 300 as in the state illustrated in FIG. On the other hand, the state indicated by the solid line in FIG. 18 is a state in which the non-image region cleaning process is executed, and the cleaning liquid supply unit 16C (clockwise in FIG. 18 is rotated by a predetermined angle from the state indicated by the dashed line in FIG. The cleaning liquid is supplied to the blade position 300 in the same manner as shown in FIG.

  The embodiment shown in FIG. 18 can be realized with a single device even when the dissolution rate or dispersion rate of the components contained in the ink with respect to the cleaning liquid is low, and is simple without increasing the size of the device. A reliable cleaning process is possible with an inexpensive configuration. In other words, compared with the mode in which the cleaning liquid supply unit 16C is moved along the intermediate transfer belt conveyance direction, the moving mechanism of the cleaning liquid supply unit 16C can be configured more compactly, which contributes to the suppression of the overall size of the apparatus. To do.

  In the embodiment shown in FIG. 18, the cleaning liquid supply distance varies between the blade position 300 and the image area supply position 302. Therefore, as in the embodiments shown in FIGS. 16 and 17, the supply pressure is changed according to the supply distance. Good.

  Next, a specific cleaning liquid supply position switching control in the embodiment shown in FIG. 18 will be described. FIG. 19 is a view of the intermediate transfer belt 12 as viewed obliquely from the lower right in FIG. 18 (a view of the surface including the image area as viewed from the opposite side).

  In FIG. 19, reference numeral 300 denotes a blade position, reference numeral 302 denotes an image area supply position to which cleaning liquid is supplied during the cleaning process of the image area 100 (100-1, 100-2,...), And supply of the blade position 300 and the image area. Let L be the distance of the position 302 in the intermediate transfer member conveyance path.

  Further, the rear end position (the front end position of the non-image area) of the previous non-image area 102-1 in the intermediate transfer belt conveyance direction is denoted by reference numeral 304, and the front end of the image area 100-2 next to the previous image area 100-1 is indicated. The position (the rear end position of the non-image area 102-1) is 306, and the interval between the rear end position 304 of the image area 100-1 and the front end position 306 of the image area 100-2 (the middle of the non-image area 102-1). Let d be the distance in the transfer member conveyance path.

  When the distance L between the blade position 300 and the image area supply position 302 is less than the length d of the non-image area 102-1, that is, when the relationship d> L is established, the cleaning liquid supply direction described in FIG. It is preferable to make changes. On the other hand, when the relationship d ≦ L holds, the cleaning liquid supply direction is not changed, and the cleaning process is performed on the non-image area 102 in the same manner as the image area 100. In other words, when d ≦ L, the supply position of the cleaning liquid during the cleaning process of the non-image area 102 is set to the same image area supply position 302 as that during the cleaning process of the image area 100, and the supply amount of the cleaning liquid is changed. Then, the non-image area 102 is cleaned.

  By controlling the change in the supply position (direction) of the cleaning liquid and the change in the supply amount of the cleaning liquid in this manner, the dirt attached to the cleaning blade 16A can be removed without impairing the cleaning of the image area 100. .

  “When the relationship of d> L is satisfied” means, for example, an unsteady operation such as an ejection failure recovery operation of the head 50 or when the printing timing is shifted to avoid printing on the joint portion of the intermediate transfer belt 12. Time is given.

  On the other hand, “when the relationship of d ≦ L is satisfied” includes, for example, a case where the interval d between the image regions 100 is set to the shortest as in normal printing. During normal printing, the interval d between the image regions 100 is set as short as possible in order to shorten the printing processing time and reduce the consumption of the cleaning liquid.

  The distance d may be intentionally changed. In the aspect in which the distance d is variable, the dirt on the cleaning blade 16A is detected by an optical sensor or the like, and when the detected dirt amount exceeds a predetermined dirt standard, the relationship of d> L is satisfied. When the distance d is set to be longer than the normal setting (the shortest setting at the time of normal printing) so as to hold, and the cleaning liquid supply unit 16C is swung as shown in FIG. 18, the intermediate transfer belt 12 is cleaned. Thus, reliable cleaning can be performed while minimizing the print processing time.

  When the relationship d> L is satisfied (when the cleaning liquid supply direction is changed), the cleaning liquid is supplied in accordance with the timing at which the rear end position 304 of the image region 100-1 moves to the blade position 300. A change of direction is made.

  FIG. 20 illustrates a state in which the rear end position 304 of the image area 100-1 has moved to the blade position 300. In the state shown in FIG. 20, the blade position 300 and the rear end position 304 of the image area 100-1 coincide with each other, the cleaning liquid supply direction is changed in accordance with this timing, and the cleaning liquid 16B is indicated by a broken line. The cleaning liquid 16B is changed from the image area supply position 302 to the blade position 300 indicated by a solid line. In FIG. 20, the changing direction of the cleaning liquid supply position is indicated by an arrow line K.

  Further, it is preferable to change the supply amount of the cleaning liquid simultaneously with the change of the supply direction of the cleaning liquid.

  Thereafter, as shown in FIG. 21, the cleaning liquid is supplied in accordance with the timing at which the rear end portion (front end portion of the next image region 100-2) 306 of the non-image region 102-1 moves to the image region supply position 302. The supply direction of the cleaning liquid is changed so that the supply position is returned from the blade position 300 (the cleaning liquid 16B is indicated by a broken line) to the image area supply position 302 (the cleaning liquid 16B is indicated by a solid line). In FIG. 21, the change direction of the cleaning liquid supply position is indicated by an arrow line K ′. Further, the supply amount of the cleaning liquid is changed simultaneously with the change of the supply direction of the cleaning liquid.

  In this way, the states shown in FIGS. 19, 20, and 21 are repeated, and the cleaning liquid supply direction and the cleaning liquid supply amount according to the movement of the intermediate transfer belt 12 (the image area 100 and the non-image area 102). Is appropriately changed, and a preferable cleaning process of the intermediate transfer belt 12 can be performed.

  19 to 21 exemplify the aspect in which the cleaning process is started from the cleaning process of the non-image area 102, it is also possible to start the cleaning process from the cleaning process of the image area 100. Further, when the apparatus is started up or at the end of the apparatus, the intermediate transfer belt 12 may be conveyed without performing image formation. In this case, it is also preferable to change the cleaning liquid supply position to the blade position 300 and directly supply the cleaning liquid 16B to the cleaning blade 16A to remove the dirt on the cleaning blade 16A. Furthermore, by directly supplying the cleaning liquid 16B to the cleaning blade 16A, the cleaning blade 16A is moistened with the cleaning liquid 16B, so that the slidability of the cleaning blade 16A is improved. As a result, the transport load of the intermediate transfer belt 12 is improved. Effects such as reduction and improvement in durability of the intermediate transfer belt 12 and the cleaning blade 16A are expected. The change in the cleaning liquid supply direction and the change in the supply amount of the cleaning liquid described above can also be applied to the parallel movement described with reference to FIGS.

  In this example, the image area 100 and the non-image area 102 are determined based on the detection result of the recording medium 14, but the image area 100 and the non-image area 102 in the cleaning process are formed (set) after the cleaning process. The image area may be determined based on the image area.

  When the image area 100 on the intermediate transfer belt 12 changes every round (for example, when the size of the recording medium 14 changes every one sheet or every several sheets), the image area set after cleaning is set. If the image area 100 is determined based on the above, there is no wiping residue of the cleaning liquid in the image area set on the intermediate transfer belt 12 after the cleaning process, and good image formation is possible. Further, the non-image area 102 at the time of the cleaning process is determined based on information on both the image area 100 formed before the cleaning and the image area formed after the cleaning, and further, as shown in FIGS. When the condition of d> L is satisfied, the cleaning liquid supply direction (supply position) may be changed. With this configuration, the intermediate transfer belt 12 before the printing operation (after transfer recording) can be reliably cleaned, and the intermediate transfer belt 12 can be cleaned without affecting the image formed after the cleaning process. Is possible.

  Further, as a method for determining the image area and the non-image area, the moving distance of the intermediate transfer belt 12 is detected by an encoder, the image length is determined from the image data, and the interval between the images is set in advance. It is also possible to determine the image area and the non-image area by reading out from.

  FIG. 22 illustrates an inkjet recording apparatus 400 having a configuration for determining an image area and a non-image area based on the moving distance of the intermediate transfer belt 12 and image data. 22 that are the same as or similar to those in FIG. 1 are given the same reference numerals, and descriptions thereof are omitted.

  An ink jet recording apparatus 400 shown in FIG. 22 includes an encoder sensor 402 and a home position sensor 404 on the back surface side (the surface opposite to the image surface) of the intermediate transfer belt 12, and the moving distance and home position of the intermediate transfer belt 12 are included. It is configured to be able to grasp (origin position).

  As shown in FIG. 23, an encoder pattern 410 and a home position pattern 412 are provided on the back side surface of the intermediate transfer belt 12. The encoder pattern 410 is provided at one end in the width direction of the intermediate transfer belt 12 and has a structure arranged along the intermediate transfer belt conveyance direction A at an arrangement pitch corresponding to the conveyance resolution of the intermediate transfer belt 12. Have.

  One home position pattern 412 is provided at the opposite end of the encoder pattern 410, and the position (state) where the home position sensor 404 detects the home position pattern 412 is determined as the home position of the intermediate transfer belt 12. ing.

  The encoder pattern 410 and the home position pattern 412 may be provided on the surface side (surface including the image area and the non-image area) of the intermediate transfer belt 12. Also, the encoder pattern 410 and the home position pattern 412 may be those having a hole shape, patterns having different densities (patterns arranged as dark, light, dark, light,...), Patterns having different reflectivities, and the like. It is.

  When the encoder pattern 410 shown in FIG. 23 is used, a reflective optical sensor is used for the encoder sensor 402, and the amount of light incident on the encoder sensor 402 exceeds a predetermined threshold value, the on-state is detected. In the following cases, it is set to OFF, and the movement distance of the intermediate transfer belt 12 is obtained from the count value by counting the ON / OFF patterns.

  Also, when the home position pattern 412 is detected by the home position sensor 404, the encoder count (counter that counts the encoder pattern 410) is reset to zero. This reset process is performed only once immediately after the start of normal printing. In this way, it is possible to determine the moving distance of the intermediate transfer belt 12 based on the home position based on the count value described above.

  Further, the length of the image (the size of the image in the intermediate transfer belt conveyance direction A) can be calculated based on the image data, and the length of the image is converted into a count value. Similarly, the interval between images (the length of the non-image area in the intermediate transfer belt conveyance direction A) is also known and converted into a count value. Further, the circumference of the intermediate transfer belt 12 is converted into a count value, and the distance from the home position sensor to the cleaning blade 16A is converted into a count value.

  First, when the recording operation is started, the start position and the end position of the image area in the first image are calculated as count values from the home position and stored in a storage device (predetermined memory). This process may be executed for all the number of recordings in the recording operation. For example, the image area for two rotations of the intermediate transfer belt 12 is calculated, and when the intermediate transfer belt 12 makes one rotation, the first one rotation is calculated. The data may be appropriately calculated in accordance with the progress of the recording operation, such as deleting data and calculating and storing data for the next one rotation. The method of appropriately calculating the positions of the image area and the non-image area in accordance with the progress of the recording operation is advantageous in that the memory capacity of the memory may be small, the storage device can be processed at high speed, and the cost can be reduced.

  FIG. 24A shows an example of image area start position information and image area end position information stored in the memory.

  Next, when determining the image area (non-image area) of the intermediate transfer belt 12 on the blade position 300 shown in FIG. 19 and the like, information on the image area start position and the end of the image area shown in FIG. The distance from the home position sensor 404 to the blade position 300 is added to the position information. FIG. 24B illustrates an example in which the count value from the home position to the blade position 300 is 20000 counts.

  That is, the image area determination unit 40 shown in FIG. 22 collates the count value with the information of the image area and the non-image area stored in the memory, and immediately below the blade position 300 when the count value is 20000 to 25000. The first (first image) image area is located, and the non-image area between the first image area and the second image area is located immediately below the blade position 300 when the count value is between 25000 and 25050. Thus, it is possible to grasp the image area and the non-image area immediately below the blade position 300 based on the count value. The second and subsequent image regions and the non-image regions after the non-image region between the second and third image regions are also grasped in the same manner.

  When determining the image area and the non-image area immediately below the image area supply position 302 shown in FIG. 19 and the like, the distance between the blade position 300 and the image area supply position 302 is the distance from the home position to the blade position 300. It can be obtained by subtracting from.

  When the image area after cleaning is taken into consideration, the count for one rotation of the intermediate transfer belt 12 is further subtracted. However, the cleaning operation is not necessary until the first image area 100 moves to the blade position 300, and the cleaning operation is not performed. FIG. 24C illustrates an example in which the count value from the home position to the blade position 300 is 20000 counts and one rotation of the intermediate transfer belt 12 is 300000 counts. In addition to FIG. 24C, the count value (20000 counts) until the first image area 100 moves to the blade position 300 is stored in the memory.

  That is, the cleaning operation is not performed until the count value is 20000, and when the count value is 20000 to 25300, the fifth image region 100 (−5) is located immediately below the blade position 300, and the count value 20250 to 20350 is displayed. During this period, it is possible to grasp the non-image area 102 of the fifth image area 100 (−5) and the sixth image area 100 (−6) immediately below the blade position 300. The seventh and subsequent image regions 100 (−7, 8, 9,...) And the non-image region 102 are grasped in the same manner.

  It is also possible to grasp the moving distance of the intermediate transfer belt 12 by counting the output signal of the encoder attached to the drive motor of the intermediate transfer belt 12.

  In the first to fourth embodiments described above, an example in which the cleaning process region of the intermediate transfer belt 12 is set in a region where the intermediate transfer belt 12 is conveyed in an oblique direction that forms a predetermined angle with the horizontal (vertical) direction is illustrated. However, a mode in which the cleaning process region of the intermediate transfer belt 12 is set in a region where the intermediate transfer belt 12 is conveyed in the horizontal direction is also applicable.

In the first to fourth embodiments described above, the two-liquid aggregation type ink jet recording apparatus using the processing liquid that reacts with the ink to thicken or aggregate the ink is exemplified, but the primary image is transferred to the intermediate transfer belt 12. The temporary fixing method is not limited to the two-liquid aggregation method, and various methods such as a method using phase change such as heating and cooling and a method of applying energy such as ultraviolet rays can be applied.
Furthermore, in the first to fourth embodiments described above, the belt-shaped intermediate transfer member is exemplified, but the present invention can also be applied to an ink jet recording apparatus including a drum-shaped or flat plate-shaped intermediate transfer member.

1 is a schematic configuration diagram of an ink jet recording apparatus according to a first embodiment of the present invention. FIG. 1 is a plan view of a main part around a printing unit of the ink jet recording apparatus shown in FIG. Plane perspective view showing a configuration example of the head shown in FIG. Sectional view along line 7-7 in FIG. FIG. 3 is an enlarged view showing the nozzle arrangement of the head shown in FIG. Schematic diagram showing the configuration of the ink supply system of the ink jet recording apparatus shown in FIG. Schematic diagram showing the configuration of the control system of the ink jet recording apparatus shown in FIG. Conceptual diagram explaining the image area cleaning process Conceptual diagram for explaining the non-image area cleaning process Illustration of image area and non-image area Explanatory drawing of injection pressure control Schematic configuration diagram of a modification of the cleaning processing unit shown in FIG. Schematic configuration diagram of a cleaning processing unit of an ink jet recording apparatus according to a second embodiment of the present invention. Explanatory drawing of the cleaning process part shown in FIG. The flowchart which shows the flow of control of the cleaning process which concerns on 3rd Embodiment of this invention. The figure explaining the cleaning process of the image area | region in the cleaning process which concerns on 4th Embodiment of this invention. The figure explaining the cleaning process of the non-image area | region in the cleaning process which concerns on 4th Embodiment of this invention. The figure explaining the other aspect of the cleaning process which concerns on 4th Embodiment of this invention. The figure explaining the cleaning liquid supply position in the other aspect shown in FIG. The figure explaining the example of a change of the cleaning liquid supply position in the other aspect shown in FIG. The figure explaining the example of a return of the cleaning liquid supply position in the other aspect shown in FIG. Schematic configuration diagram of another aspect of the ink jet recording apparatus shown in FIG. FIG. 1 is a schematic plan view showing a configuration example of an intermediate transfer belt of the ink jet recording apparatus shown in FIG. The figure explaining the information in the memory of the inkjet recording device shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10,200,400 ... Inkjet recording device, 12 ... Intermediate transfer belt, 14 ... Recording medium, 16,216 ... Cleaning processing part, 16A ... Blade, 16C, 202, 204 ... Cleaning liquid supply part, 22 ... Printing part, 24 DESCRIPTION OF SYMBOLS Transfer recording part 34 ... Cleaning liquid supply path 38 ... Sensor 40 ... Image area judgment part 42 ... Cleaning liquid flow rate control part 100 ... Image area 102 ... Non-image area 120 ... Solenoid valve

Claims (12)

An intermediate transfer member;
Conveying means for conveying the intermediate transfer member in a predetermined conveying direction;
Image forming means for forming a primary image on the intermediate transfer member;
Transfer recording means for transferring and recording a primary image formed on the intermediate transfer member on a recording medium;
Cleaning liquid supply means for supplying a cleaning liquid to the cleaning target area of the intermediate transfer member;
Wiping means for wiping the intermediate transfer body supplied with cleaning liquid from the cleaning liquid supply means to the area to be cleaned;
A cleaning target region determining means for determining whether the cleaning target region of the intermediate transfer member is an image region including a region for forming a primary image or a non-image region other than the image region;
When the cleaning target area is determined to be an image area by the cleaning target area determination unit, the cleaning liquid supply unit supplies the cleaning liquid so as to reduce the amount of cleaning liquid supplied during the cleaning process of the non-image area. The cleaning liquid supply control means for controlling the supply amount of the cleaning liquid.
An image forming apparatus comprising: The cleaning target area determination means determines the amount of deposits attached to the cleaning target area,
The cleaning liquid supply control means supplies the cleaning liquid supplied from the cleaning liquid supply means when the cleaning target area determination means determines that the amount of deposits adhering to the cleaning target area is relatively large. When it is determined that the amount of deposits adhering to the area to be cleaned is relatively small while the amount of the cleaning liquid supplied is relatively small, the amount of cleaning liquid supplied from the cleaning liquid supply unit is relatively small. As described above, the supply amount of the cleaning liquid supplied from the cleaning liquid supply unit is controlled in accordance with the amount of deposits in the cleaning target region determined by the cleaning target region determination unit. Item 2. The image forming apparatus according to Item 1. A recording medium detecting means for detecting the leading end and the trailing end of the recording medium after the transfer recording by the transfer recording means;
The cleaning target area determination means determines that the cleaning target area is an image area when the recording medium detection means detects the leading edge of the recording medium, and the recording medium detection means determines the trailing edge of the recording medium. 3. The image forming apparatus according to claim 1, wherein when the portion is detected, the area to be cleaned is determined to be a non-image area. A position detecting means for detecting the position of the intermediate transfer member on the conveyance path;
The cleaning target area determination unit determines an image area and a non-image area on the conveyance path of the intermediate transfer member based on image data, and compares the detection target area with the detection result of the position detection unit. The image forming apparatus according to claim 1, wherein the image forming apparatus determines whether the area is a non-image area. The cleaning liquid supply means includes a first cleaning liquid supply unit that supplies a first cleaning liquid to the intermediate transfer member;
A second cleaning liquid supply unit configured to supply a second cleaning liquid having a smaller surfactant content than the first cleaning liquid to the intermediate transfer member;
The cleaning liquid supply control means supplies the first cleaning liquid from the first cleaning liquid supply unit during the cleaning process of the non-image area, and the second cleaning liquid supply unit during the cleaning process of the image area. 5. The control device according to claim 1, wherein the first cleaning liquid supply unit and the second cleaning liquid supply unit are controlled so as to supply a second cleaning liquid from the first cleaning liquid supply unit. Image forming apparatus. The cleaning liquid supply means includes a first cleaning liquid supply unit that supplies a first cleaning liquid to the intermediate transfer member;
A second cleaning liquid supply unit that supplies a second cleaning liquid having a viscosity lower than that of the first cleaning liquid to the intermediate transfer member;
The cleaning liquid supply control means supplies the first cleaning liquid from the first cleaning liquid supply unit during the cleaning process of the non-image area, and the second cleaning liquid supply unit during the cleaning process of the image area. 5. The control device according to claim 1, wherein the first cleaning liquid supply unit and the second cleaning liquid supply unit are controlled so as to supply a second cleaning liquid from the first cleaning liquid supply unit. Image forming apparatus. The cleaning liquid supply means includes a first cleaning liquid supply path communicating with the first cleaning liquid supply section;
A second cleaning liquid supply path communicating with the second cleaning liquid supply section;
The first cleaning liquid supply path and the second cleaning liquid supply path communicate with the first cleaning liquid supply section and a common cleaning liquid supplied to the second cleaning liquid supply section is accommodated. Cleaning liquid storage means;
Heating means for heating the cleaning liquid in the first cleaning liquid supply path;
Cooling means for cooling the liquid in the second cleaning liquid supply path;
With
The common cleaning liquid whose viscosity has been reduced by the heating means is supplied from the first cleaning liquid supply section to the intermediate transfer body, and the common cleaning liquid whose viscosity has been increased by the cooling means is supplied to the second cleaning liquid. The image forming apparatus according to claim 6, wherein the image forming apparatus supplies the intermediate transfer member from a cleaning liquid supply unit. With measuring means for measuring the elapsed time from the end of image recording,
When the elapsed time measured by the measuring unit exceeds a predetermined time, the intermediate transfer member is transported in a predetermined transport direction without operating the image forming unit, and the cleaning liquid supply unit The cleaning process for the intermediate transfer member is performed by supplying a cleaning liquid to the intermediate transfer member under the same conditions as in the non-image region cleaning process. 2. The image forming apparatus according to item 1.   In the cleaning process of the area determined as the non-image area by the cleaning target area determination unit, the cleaning liquid is supplied from the cleaning liquid supply unit to the contact position between the intermediate transfer member and the wiping unit, and the cleaning target area In the cleaning process of the area determined as the image area by the determination unit, the cleaning liquid is supplied from the cleaning liquid supply unit to a position separated from the contact position between the intermediate transfer member and the wiping unit by a predetermined distance. The image forming apparatus according to claim 1, further comprising a moving unit that moves the cleaning liquid supply unit.   In the cleaning process of the area determined as the non-image area by the cleaning target area determination unit, the cleaning liquid is supplied from the cleaning liquid supply unit to the contact position between the intermediate transfer member and the wiping unit, and the cleaning target area In the cleaning process of the area determined as the image area by the determination unit, the cleaning liquid is supplied from the cleaning liquid supply unit to a position separated from the contact position between the intermediate transfer member and the wiping unit by a predetermined distance. The cleaning liquid supply unit is rotated about a rotation axis in a direction that is greater than 0 ° and not greater than 90 ° with respect to the conveyance direction of the intermediate transfer body to change the ejection direction of the cleaning liquid. 9. A rotating means for changing a supply position of the cleaning liquid is provided. The image forming apparatus according to claim 1. The image forming unit includes a processing liquid application unit that applies a processing liquid that reacts with the ink forming the primary image to thicken, aggregate, or insolubilize the ink, to the intermediate transfer member;
Drying means for drying the treatment liquid applied to the intermediate transfer member by the treatment liquid application means;
A head for ejecting the ink onto the intermediate transfer member;
The image forming apparatus according to claim 1, further comprising: A method of cleaning an intermediate transfer body in an image forming apparatus that forms a primary image while transporting the intermediate transfer body in a predetermined transport direction, and transfers and records the primary image formed on the intermediate transfer body onto a recording medium. And
It is determined whether the cleaning target area of the intermediate transfer body is an image area including an area for forming a primary image or a non-image area other than the image area, and the cleaning target area is determined as an image area. In this case, the supply amount of the cleaning liquid is controlled so as to reduce the supply amount of the cleaning liquid with respect to the cleaning process of the non-image area, and the intermediate transfer body having the cleaning liquid supplied to the area to be cleaned is removed. A method for cleaning an intermediate transfer member, characterized by wiping.

Images