JP2011046067A - Liquid ejector and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form a different degree of gloss on the surface of each recording medium even when each recording medium is neither heated at a different temperature nor contacted by a member having different smoothness. <P>SOLUTION: A transparent liquid 38A is added to liquid receptive particles 16 to increase the amount of liquid received by the liquid receptive particles 16 to thereby improve the gloss of the recording medium P. Then, even if each recording medium P is neither heated at the different temperature nor contacted by the member of different smoothness, the different degree of gloss can be formed on the surface of each recording medium P by changing the supply amount of the transparent liquid 38A to each recording medium P. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a liquid ejection apparatus and an image forming apparatus.

  As an image forming apparatus, an image forming apparatus disclosed in Patent Document 1 is known. The image forming apparatus disclosed in Patent Document 1 includes at least a particle layer forming step of forming a resin particle layer 8 with resin particles 2 on the surface of the intermediate transfer member 6 or the recording medium 6, and an ink jet recording head on the resin particle layer 8. From the surface of the intermediate transfer body 6 to the recording medium 6 ′, and a recording step of recording the image by discharging the ink 4 from the surface and holding the ink 4 in the voids of the resin particle layer 8. And a fixing step of fixing the recording medium 6 having the resin particle layer 8 holding the ink 4 to form an image.

Japanese Patent Laying-Open No. 2003-57967 (FIG. 1)

  The present invention is capable of forming glosses having different degrees on the surface of each recording medium even when the recording medium is not heated at different temperatures or contacted by members having different smoothness. Let it be an issue.

  The invention according to claim 1 is a liquid ejection unit that ejects liquid, a particle supply device that supplies liquid receptive particles that can receive the liquid, and the liquid supply unit that ejects the liquid from the liquid ejection unit. A transfer body for transferring the liquid receptive particles receiving the liquid to the surface of the recording medium, and a transparent liquid that can be received by the liquid receptive particles. A transparent liquid supply device that supplies the liquid according to the glossiness, and a heating unit that heats the liquid receptive particles on the recording medium, the liquid received by the liquid receptive particles, and the transparent liquid. A liquid ejection device;

  According to a second aspect of the present invention, the transparent liquid supply device supplies the transparent liquid to the transfer body, and the transfer body transfers the liquid receptive particles that have received the transparent liquid and the liquid to the surface of the recording medium. The heating unit heats the liquid receptive particles, the liquid received by the liquid receptive particles, and the transparent liquid when the liquid receptive particles are transferred from the transfer body to the recording medium. The liquid ejection device according to claim 1.

  A third aspect of the invention is the liquid ejection device according to the first aspect, wherein the transparent liquid supply device supplies the transparent liquid to the liquid receptive particles transferred from the transfer body to the recording medium.

  According to a fourth aspect of the present invention, there is provided a liquid ejection unit that ejects liquid onto the surface of the recording medium, a particle supply device that supplies liquid receptive particles capable of receiving the liquid to the surface of the recording medium, and the liquid receptivity. Transparent liquid supply device for supplying transparent liquid that can accept particles to the recording medium according to the target gloss of the surface of the recording medium, the liquid receptive particles supplied to the recording medium, and the liquid And a heating unit that heats the liquid received by the receptive particles and the transparent liquid.

  According to a fifth aspect of the present invention, in the transparent liquid supply device, the supply amount of the transparent liquid can be switched for each region desired to have the target gloss for one recording medium. The liquid discharge apparatus according to any one of the above.

  According to a sixth aspect of the present invention, in the region where the transparent liquid supply device is desired to have the target gloss, the transparent liquid is supplied to the portion where the liquid supply amount is smaller than the other portion than the other portion. The liquid ejection device according to claim 1, wherein a large amount is supplied.

  According to a seventh aspect of the present invention, in the region where the transparent liquid supply device is desired to have a gloss lower than the target gloss, the sum of the supply amounts of the liquid and the transparent liquid is a region where the target gloss is desired. The transparent liquid is supplied more than the other part to the part where the supply amount of the liquid is smaller than the other part in a range that is less than or equal to the sum of the supply amount of the liquid and the transparent liquid in the part. The liquid ejection device according to claim 6.

  According to an eighth aspect of the present invention, the transparent liquid supply device supplies the transparent liquid so that a sum of a supply amount of the liquid and a supply amount of the transparent liquid to each part is constant. Item 8. The liquid ejection device according to Item 7.

  According to a ninth aspect of the present invention, the liquid discharge unit discharges the liquid droplet, and the transparent liquid supply device performs the operation in one operation with respect to a range wider than a range where one of the droplets lands. The liquid discharging apparatus according to claim 1, wherein a transparent liquid can be supplied.

  According to a tenth aspect of the present invention, there is provided the liquid ejecting apparatus according to any one of the first to ninth aspects, wherein an image is formed by ejecting the liquid onto the recording medium, and the liquid ejecting apparatus. An image forming apparatus comprising: a conveying unit that conveys a medium.

  According to the configuration of the first aspect of the present invention, even if the recording medium is not heated at different temperatures or contacted by a member having different smoothness, the surface of each recording medium has a different degree of gloss. Can be formed.

  According to the configuration of the second aspect of the present invention, the liquid receptive particles can be heated with a simple configuration as compared with the case where heating is not performed when the liquid receptive particles are transferred from the intermediate transfer member to the recording medium. it can.

  According to the configuration of the third aspect of the present invention, it is possible to suppress the displacement of the transfer position when the liquid receptive particles are transferred to the recording medium, compared to the case where the transparent liquid is supplied to the intermediate transfer member.

  According to the configuration of the fourth aspect of the present invention, even when the recording medium is not heated at different temperatures or contacted by a member having different smoothness, the surface of each recording medium has a different degree of gloss. Can be formed.

  According to the configuration of the fifth aspect of the present invention, it is possible to form gloss having partially different degrees on the surface of one recording medium.

  According to the configuration of claim 6 of the present invention, compared to the case where the transparent liquid is not supplied more than the other part with respect to the part where the liquid supply amount is smaller than the other part in the region where the desired gloss is desired, The gloss can be made uniform in the region where the target gloss is desired.

  According to the configuration of the seventh aspect of the present invention, the transparent liquid is not supplied more than the other part to the part where the liquid supply amount is smaller than the other part in the region where the gloss is desired to be lower than the target gloss. Compared to the case, the gloss can be made uniform in a region where the gloss is desired to be lower than the target gloss.

  According to the structure of Claim 8 of this invention, gloss can be equalized compared with the case where a transparent liquid is not supplied so that the sum of the supply quantity of a liquid with respect to each site | part and the supply quantity of a transparent liquid may become fixed.

  According to the configuration of the ninth aspect of the present invention, it is possible to reduce the number of operations for supplying the transparent liquid, compared to a case where the transparent liquid cannot be supplied in one operation over a range wider than the range where one droplet lands.

  According to the configuration of the tenth aspect of the present invention, even if the recording medium is not heated at different temperatures or contacted by members having different smoothness, the surface of each recording medium has a different degree of gloss. Can be formed.

FIG. 1 is a schematic diagram illustrating a configuration of an image forming apparatus according to the present embodiment. FIG. 2 is a schematic view showing a modification in which the transfer member is constituted by a heating roll. FIG. 3 is a graph showing the relationship between the amount of liquid supplied to the liquid receptive particles and the gloss of the recording medium. FIG. 4 is an explanatory diagram for explaining processing for determining the amount of transparent liquid to be supplied in dot units. FIG. 5 is a schematic diagram showing a configuration in which a transparent liquid is supplied to the liquid receptive particles transferred from the intermediate transfer member to the recording medium. FIG. 6 is a schematic diagram showing a configuration in which an image is directly formed on a recording medium without an intermediate transfer member.

  Below, an example of an embodiment concerning the present invention is described based on a drawing.

(Whole structure of the image forming apparatus according to the present embodiment)
First, the overall configuration of the image forming apparatus according to the present embodiment will be described. FIG. 1 is a schematic diagram illustrating the overall configuration of the image forming apparatus according to the present embodiment.

  The image forming apparatus 10 according to the present embodiment transports a liquid ejection apparatus 11 that forms an image by ejecting ink as an example of a liquid onto the recording medium P, and a recording medium P on which an image is formed by the liquid ejection apparatus 11. Conveying means 40.

  The transport unit 40 includes, for example, a transport roll that transports the recording medium P in between, and a recording medium discharge unit (not shown) that stores the recording medium P from which the recording medium P is discharged (not shown). The recording medium P is transported toward (not shown).

  Further, as the recording medium P on which an image is formed, for example, a penetrating medium (for example, plain paper or inkjet coated paper) or a non-penetrating medium (for example, art paper, resin film, or the like) is used. Further, the recording medium P is not limited to these, and may be an industrial product such as a semiconductor substrate.

  As shown in FIG. 1, the liquid ejection apparatus 11 according to the present embodiment includes an intermediate transfer body 12 as an example of a transfer body that transfers liquid receptive particles 16 to be described later to the surface of a recording medium P. The intermediate transfer body 12 is formed in an annular shape and is configured to rotate (circulate and move) in one direction (counterclockwise in FIG. 1).

  A charging device 14 for charging the surface of the intermediate transfer body 12 is disposed on the outer peripheral side of the intermediate transfer body 12. A particle supply device 18 for supplying the liquid receptive particles 16 to the surface of the intermediate transfer member 12 is disposed on the outer peripheral side of the intermediate transfer member 12 on the downstream side in the rotation direction of the intermediate transfer member 12 when viewed from the charging device 14. .

  On the downstream side in the rotation direction of the intermediate transfer body 12 when viewed from the particle supply device 18, as an example of a liquid discharge unit that discharges liquid, ink droplets are discharged to the liquid receptive particles 16 supplied by the particle supply device 18. An ink jet recording head 20 that forms an image is disposed on the outer peripheral side of the intermediate transfer body 12.

  A transparent liquid supply device 38 for supplying a transparent liquid 38A to the intermediate transfer body 12 is disposed on the outer peripheral side of the intermediate transfer body 12 on the downstream side in the rotation direction of the intermediate transfer body 12 when viewed from the inkjet recording head 20.

  On the downstream side in the rotation direction of the intermediate transfer body 12 when viewed from the transparent liquid supply device 38, a transfer member 22 that transfers the liquid receptive particles 16 that have received the ink and the transparent liquid 38A from the intermediate transfer body 12 to the recording medium P, The intermediate transfer body 12 is disposed so as to be sandwiched from the inner peripheral side and the outer peripheral side.

  A removal device 24 for removing the liquid receptive particles 16 remaining on the surface of the intermediate transfer body 12 is disposed on the outer peripheral side of the intermediate transfer body 12 on the downstream side in the rotation direction of the intermediate transfer body 12 when viewed from the transfer member 22. Has been.

  On the downstream side in the rotation direction of the intermediate transfer body 12 as viewed from the removing device 24, a static eliminator 26 for removing charges remaining on the surface of the intermediate transfer body 12 is disposed on the outer peripheral side of the intermediate transfer body 12.

  As the static eliminator 26, for example, a conductive roll is used and sandwiched with a driven roll 34 (ground) around which the intermediate transfer body 12 is wound, and an AC voltage of about ± 3 kV and about 500 Hz is applied to the surface of the intermediate transfer body 12. When applied, the surface of the intermediate transfer body 12 is neutralized. In addition, the structure which does not provide the static elimination device 26 may be sufficient.

  The liquid ejection device 11 includes a fixing device 64 that fixes the liquid receptive particles 16 transferred to the recording medium P by the transfer member 22 to the recording medium P.

  A release layer forming device (not shown) for forming a release layer on the intermediate transfer body 12 is provided on the outer peripheral side of the intermediate transfer body 12 so that the liquid receptive particles 16 are easily released from the surface of the intermediate transfer body 12. The structure arrange | positioned may be sufficient.

(Configuration of intermediate transfer body 12)
Next, the configuration of the intermediate transfer body 12 will be described.

  The intermediate transfer body 12 is constituted by, for example, a seamless endless belt. The intermediate transfer body 12 functions as a contact member that comes into contact with the recording surface of the recording medium P, and the surface of the intermediate transfer body 12 needs to have smoothness for making the recording medium P glossy.

  A material with high smoothness is selected for the intermediate transfer body 12, and for example, ETFE (ethylene-tetrafluoroethylene copolymer) or Si film (silicon film) is used. The intermediate transfer body 12 is not limited to the above-described material, and may be made of any other material than the above as long as it has a surface smoothness that allows the recording medium P to exhibit the necessary gloss. May be used.

  Further, the intermediate transfer member is not limited to the intermediate transfer member 12 formed of a belt, and may be an intermediate transfer drum.

(Configuration of charging device 14)
Next, the configuration of the charging device 14 will be described.

  The charging device 14 is configured to charge the surface of the intermediate transfer body 12 to a positive charge by applying a charge opposite to the charge of the liquid receptive particles 16 to the surface of the intermediate transfer body 12.

  In the present embodiment, the charging device 14 applies a voltage between the charging device 14 and a driven roll 34 disposed with the intermediate transfer member 12 interposed therebetween, and charges the surface of the intermediate transfer member 12. Has been.

  The charging device 14 is connected to a high voltage power source, and the driven roll 34 is electrically connected to the ground. The charging device 14 is driven while sandwiching the intermediate transfer body 12 with the driven roll 34, and at the contact position, a potential difference is generated with the grounded driven roll 34, so that the surface of the intermediate transfer body 12 is charged. Is granted.

  Note that a potential at which the liquid receptive particles 16 can be adsorbed on the surface of the intermediate transfer body 12 may be formed by an electrostatic force generated by an electric field that can be formed between the supply roll 18 </ b> A of the particle supply device 18 and the surface of the intermediate transfer body 12. . Further, the charging device 14 may be configured by a non-contact charging device such as a corotron.

  In the present embodiment, the electrostatic method in which the liquid receptive particles 16 are attracted to the intermediate transfer body 12 by electrostatic force is used. However, the present invention is not limited to this, and other methods may be used. Any method can be used as long as it can adsorb 16 to the intermediate transfer body 12.

(Configuration of particle supply device 18)
Next, the configuration of the particle supply device 18 will be described.

  The particle supply device 18 is a device that supplies the liquid receptive particles 16 to the surface of the intermediate transfer member 12 and forms the liquid receptive particle layer 16 </ b> A on the surface of the intermediate transfer member 12.

  The particle supply device 18 is provided with a supply roll (conductive roll) 18A at a portion facing the intermediate transfer body 12, and further, a charging blade (conductive) that presses the liquid receptive particles 16 against the surface of the supply roll 18A. Blade) 18B. The charging blade 18B also has a function of regulating the layer thickness of the liquid receptive particles 16 supplied to the surface of the supply roll 18A.

  The charging blade 18B supplies the liquid receptive particles 16 to the supply roll 18A, regulates the thickness of the liquid receptive particle layer 16A, and is negatively liquid receptive particles having a polarity opposite to the charge on the surface of the intermediate transfer body 12. Layer 16A is charged.

  As a result, the liquid receptive particles 16 in the particle supply device 18 are supplied to the intermediate transfer body 12 by the electrostatic force charged by the charging blade 18B (that is, supplied in layers on the intermediate transfer body 12). Is adjusted).

  The supply roll 18A is a solid aluminum roll, and the charging blade 18B is a metal plate (stainless steel or the like) on which urethane rubber is attached in order to apply pressure.

  Further, a cleaning roll 18C for cleaning residual particles remaining on the surface of the supply roll 18A without moving to the surface of the recording medium P while being driven to rotate with the supply roll 18A is provided adjacent to the supply roll 18A.

(Liquid receptive particles)
Next, the liquid receptive particles 16 will be described.

  The liquid receptive particles 16 in the present embodiment receive the ink component and the clear liquid component when the ink and the clear liquid 38A come into contact with the liquid receptive particles 16. Here, acceptability means holding at least a part (at least a liquid component) of the ink component and the transparent liquid component.

  The liquid receptive particles 16 are required to have a hydrophilic polymer. Specifically, for example, a styrene / acrylic acid ester / acrylic acid copolymer is used as the liquid receptive particles 16. The particle has an acid value of 150 and a neutralization degree of 100.

(Configuration of inkjet recording head)
Next, the configuration of the inkjet recording head 20 will be described.

  The inkjet recording head 20 includes an inkjet recording head 20Y that ejects yellow ink droplets from the nozzles, an inkjet recording head 20M that ejects magenta ink droplets from the nozzles, and an inkjet recording head 20C that ejects cyan ink droplets from the nozzles. And an inkjet recording head 20K that discharges black ink droplets from the nozzles. These ink jet recording heads 20 are driven by piezoelectric (piezo), thermal, or the like.

  The ink jet recording head 20 has a recording width equal to or larger than a recording area, and is configured to record an image by ejecting ink droplets onto the liquid receptive particles 16 on the surface of the intermediate transfer body 12 that is relatively moved. .

  In addition, water-based ink is used as the ink ejected from the inkjet recording head 20. The water-based ink contains an ink solvent (for example, water, a water-soluble organic solvent) in addition to a recording material such as a color material. Moreover, the other additive may be included as needed.

(Configuration of transfer member 22)
Next, the configuration of the transfer member 22 will be described.

  The transfer member 22 is disposed opposite to the intermediate transfer body 12, and includes a transport roll 22 </ b> A that transports the recording medium P with the intermediate transfer body 12 sandwiching the recording medium P therebetween, and the transport roll 22 </ b> A side from the inner periphery of the intermediate transfer body 12. And a driven pressure roll 22B that pressurizes the pressure.

  The transport roll 22A and the driven pressure roll 22B include, for example, a roll in which the outer surface of an aluminum core is coated with silicone rubber and further coated with a PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer) tube. Is used.

  The transfer member 22 transports the recording medium P sandwiched between the intermediate transfer body 12 and the transport roll 22A in a state where the driven pressure roll 22B applies pressure to the transport roll 22A side, whereby the liquid receptive particle layer. 16A is attached to the recording medium P. As a result, the liquid receptive particle layer 16 </ b> A on the surface of the intermediate transfer body 12 is transferred to the recording medium P.

  In addition, 22 A of conveyance rolls may be comprised by the heating roll which incorporates the heating source as an example of a heating part, as shown in FIG. In this configuration, the transport roll 22A, which is a heating roll, applies heat to the liquid receptive particle layer 16A on the recording medium P (specifically, between the recording medium P and the intermediate transfer body 12) to thereby form a liquid. The viscosity of the receptive particle layer 16A is lowered (the viscosity is controlled so as to be easily transferred), and the liquid receptive particle layer 16A is adhered to the recording medium P.

  At this time, the heating temperature at which the transport roll 22A heats the liquid receptive particles 16 is, for example, 50 ° C. or higher and 100 ° C. or lower when a styrene / acrylic ester / acrylic acid copolymer is used as the liquid receptive particles 16. It is said. When the temperature is 100 ° C. or higher, the viscosity of the liquid receptive particle layer 16A is lowered, resulting in poor transfer to the recording medium P. When the temperature is 50 ° C. or lower, the interface of the liquid receptive particles 16 remains, the fixing strength is weak, and the image is broken. This is because it becomes easier.

  In the configuration using a heating roll containing a heating source as the transport roll 22A, as shown in FIG. 2, the fixing device 64 is not required. However, also in this configuration, the fixing device 64 may be provided.

(Configuration of the removal device 24)
Next, the configuration of the removing device 24 will be described.

  The removal device 24 includes a removal blade 24 </ b> A that scrapes off the liquid-receptive particles 16 remaining on the intermediate transfer body 12 as an example of a contact member that contacts the intermediate transfer body 12 and removes the liquid-receptive particles 16. On the inner peripheral side of the intermediate transfer body 12, an opposing roll 28 is disposed opposite the removal blade 24A with the intermediate transfer body 12 sandwiched between the removal blade 24A.

  The removal blade 24A is constituted by a plate-like blade made of a rubber material such as polyurethane, for example. The tip of the removal blade 24A comes into contact with the intermediate transfer body 12, and the intermediate transfer body 12 rotates, whereby the removal blade 24A is rubbed against the intermediate transfer body 12 and the liquid receptive particles 16 are scraped off. At this time, foreign matter (powder etc. of the recording medium P) other than the liquid receptive particles 16 attached to the surface of the intermediate transfer body 12 is also scraped and removed together with the liquid receptive particles 16.

  The removal blade 24 </ b> A is not limited to the configuration in which the removal blade 24 </ b> A is always in contact with the intermediate transfer body 12, and may be configured to be in contact with or separated from the intermediate transfer body 12. In this configuration, for example, the liquid-receptive particles 16 may be removed by periodically bringing the removal blade 24A into contact with the intermediate transfer body 12 in accordance with the number of recording media P on which images have been recorded.

  Further, the removing device 24 includes an accommodating portion 24B that accommodates the liquid receptive particles 16 scraped by the removing blade 24A. The accommodating portion 24B is configured by a box having an open top, and serves as a receiving portion that receives the liquid receptive particles 16 that have been scraped and dropped by the removal blade 24A.

(Configuration of Fixing Device 64)
Next, the configuration of the fixing device 64 will be described.

  As shown in FIG. 1, the fixing device 64 includes a heating roll 64A having a heating source and a pressure roll 64B provided to face the heating roll 64A as an example of a heating unit. The heating roll 64A is disposed on the recording surface side of the recording medium P, and the pressure roll 64B is disposed on the non-recording surface side of the recording medium P.

  The heating roll 64A and the pressure roll 64B are configured to rotate while sandwiching the recording medium P to heat and pressurize the liquid receptive particle layer 16A on the recording medium P. The heating roll 64A functions as a contact member that comes into contact with the recording surface of the recording medium P, and the surface of the heating roll 64A needs to have smoothness for making the recording medium P glossy.

  A material with high smoothness is selected for the heating roll 64A, and for example, a roll using ETFE (ethylene-tetrafluoroethylene copolymer) is applied. The heating roll 64A is not limited to the above-described material, and may be made of a material other than the above as long as it has surface smoothness to the extent that the recording medium P can exhibit the necessary gloss. A thing may be used.

  The heating temperature at which the heating roll 64A heats the liquid receptive particles 16 is, for example, 50 ° C. or higher and 100 ° C. or lower when a styrene / acrylic ester / acrylic acid copolymer is used as the liquid receptive particles 16. Is done. When the temperature is 100 ° C. or higher, the viscosity of the liquid receptive particle layer 16A is lowered, resulting in poor transfer to the recording medium P. When the temperature is 50 ° C. or lower, the interface of the liquid receptive particles 16 remains, the fixing strength is weak, and the image is broken. This is because it becomes easier.

(Configuration of transparent liquid supply device 38)
Next, the configuration of the transparent liquid supply device 38 will be described.

  As with the inkjet recording head 20, the transparent liquid supply device 38 is configured by an ejection head that ejects the transparent liquid 38 </ b> A toward the intermediate transfer body 12.

  These discharge heads are driven by a piezoelectric method, a thermal method, or the like. The discharge head has a supply width equal to or greater than the recording area, and supplies the liquid droplets of the transparent liquid 38A by discharging the transparent liquid 38A to the liquid receptive particles 16 on the surface of the intermediate transfer body 12 that moves relatively. It is configured as follows.

  In the present embodiment, the supply amount of the transparent liquid 38A can be switched with respect to each of a plurality of portions (specifically, each dot) of one recording medium P by using an ejection head. The supply amount to be switched includes a case where the supply amount is 0.

(Transparent liquid 38A)
Next, the transparent liquid 38A will be described.

For example, water (specifically, pure water) is used as the transparent liquid 38A. The transparent liquid 38A may be composed only of water, but if necessary, other than organic solvents, surfactants, polymers, preservatives, etc., for ejection stability and long-term storage. An additive may be included. The transparent liquid 38A is not limited to the above liquid, and other liquids may be used. The transparent liquid 38A refers to a liquid that is transparent to the extent that the color of the image by ink is not affected. Here, “a degree that does not affect the color” specifically refers to a case where the color difference ΔE in the CIEL ^* a ^* b ^* space is 10 or less.

FIG. 3 is a graph showing the relationship between the amount of liquid (ink amount + transparent liquid amount) supplied to the liquid receptive particles 16 and the gloss of the recording medium P. This graph has the configuration shown in FIG. 2 (configuration in which the transport roll 22A is a heating roll) in the image forming apparatus 10 according to the present embodiment, and the liquid receptive particle layer 16A is 0.7 mg / mg. The test results are shown in the case where the layer is formed to be cm ² ) and heated at 80 ° C. with the transport roll 22A. In this graph, 1.8 (mg / cm ² ) corresponds to 8 pl. The glossiness (%) is measured in accordance with JIS Z 8741 under conditions where the incident angle and the light receiving angle are 60 degrees.

As shown in the graph of FIG. 3, the recording medium P has a low gloss (20% or less) in the region of the ink discharge amount (0.75 (mg / cm ² ) or less) that has been mainly used so far. However, it has been found that a high gloss (70% or more) is obtained by supplying the liquid receptive particles 16 with a liquid of, for example, 1.5 (mg / cm ² ) or more. That is, conventionally, in order to adjust the gloss of the recording medium P, the heating temperature (transfer temperature or fixing temperature) for the recording medium P is changed, or members (belts or rolls) having different smoothness are brought into contact with the recording medium P. However, even if the transfer temperature, the fixing temperature, the smoothness of the intermediate transfer body 12 and the smoothness of the heating roll 64A are the same, the amount of liquid received by the liquid receptive particles 16 It was found that the gloss of the recording medium P can be adjusted by adjusting.

  This is because the liquid receptive particles 16 absorb a larger amount of water, so that the liquid receptive particles 16 can sufficiently follow the surface of the contact member (for example, the intermediate transfer body 12 or the heating roll 64A) that contacts the surface of the recording medium P.・ It is assumed that fluidity can be obtained. Further, even when the contact member does not come into contact with the surface of the recording medium P, the liquid receptive particles 16 are obtained by obtaining flexibility and fluidity so that the unevenness of the surface is eliminated by its own weight and becomes smooth. Inferred.

  Here, a supply process for supplying the transparent liquid 38A to the intermediate transfer body 12 will be described.

  First, processing for specifying an area in the recording medium P where gloss is desired to be improved is performed. For example, an area to be improved in glossiness is specified by performing extraction processing on an image formed by the inkjet recording head 20 by an application or a printer driver. Specific portions to be extracted are a character, a picture, both of the character and the picture, a person, a background, a bright part, a dark part, the entire image, and other areas.

  In addition to the image formed by the inkjet recording head 20, a region where gloss is desired to be improved may be specified. In this case, for example, it is specified by pattern information and image information generated separately from the image information of the image formed by the inkjet recording head 20.

  Specifically, it may be possible to insert a company logo or character in addition to the image formed by the ink jet recording head 20, or to describe a header or footer of a document.

  Further, in the configuration in which the transparent liquid 38A is supplied in units of dots by the ejection head as in the present embodiment, an area where gloss is desired to be improved is specified in units of dots.

  Next, processing for determining the supply amount of the transparent liquid 38A is performed according to the target gloss. Ink supply amount information in units of dots supplied from the inkjet recording head 20 to the recording medium P is acquired. From this ink supply amount information, the difference from the total liquid amount for one dot necessary for the target gloss is calculated, and the supply amount of the transparent liquid 38A is determined. The transparent liquid supply device 38 is configured to supply the transparent liquid 38A to the intermediate transfer body 12 based on the determined supply amount. The supply amount here includes a case where the supply amount is zero.

  For example, the shaded portion in FIG. 4A is a high-gloss region that is desired to have a higher gloss than the other portions, and the total liquid amount for one dot required for the target high gloss is 8 pl. In this case, the supply amount of the transparent liquid 38A is as follows. That is, when the ink supply amount in dot units of the inkjet recording head 20 is 4, 2, 4, 2, 4, 2, 0, 0, 2 pl as shown in FIG. As shown in (C), the supply amount of the transparent liquid 38A is 4, 6, 4, 6, 4, 6, 8, 8, 6 pl.

  In this way, in the high gloss region, the transparent liquid 38A is supplied more than the other part to the part where the amount of ink supplied is smaller than the other part. Specifically, in the high gloss region, the transparent liquid 38A is supplied so that the sum of the ink supply amount and the transparent liquid 38A supply amount to each part is constant. Here, “the sum of the supply amounts is constant” means that the difference in gloss between the parts is within 10%. Therefore, when the sum of the supply amount of a certain part is set to 100, the sum of the supply amount of another part exists in the range of 90 or more and 100 or less.

  Further, the region other than the high gloss region (shaded portion in FIG. 4A) that is desired to have a higher gloss than the other portion is made lower gloss than the high gloss region. In the case where the desired low gloss area is selected and the total liquid amount for one dot necessary for the target low gloss is 4 pl, the supply amount of the transparent liquid 38A is as follows. That is, as shown in FIG. 4B, for example, when the first row is 2, 4, 2, 4, 2, 2 pl as shown in FIG. As shown in (C), the supply amount of the transparent liquid 38A is 2, 0, 2, 0, 2, 2 pl. In this low gloss region, the amount of ink supplied is higher than that of the other portions in a range where the sum of the supply amounts of ink and transparent liquid 38A is less than or equal to the sum of the amounts of supply of ink and transparent liquid 38A in the high gloss region. A larger amount of the transparent liquid 38A is supplied to a portion having a smaller amount than the other portions. Specifically, in the low gloss region, the transparent liquid 38A is supplied so that the sum of the ink supply amount and the transparent liquid 38A supply amount to each part is constant. Here, “the sum of the supply amounts is constant” means that the difference in gloss between the respective parts is within 10%, as described above.

(Operation of the image forming apparatus according to the present embodiment)
Next, the operation of the image forming apparatus according to this embodiment will be described.

  In the image forming apparatus 10 according to the present embodiment, first, the intermediate transfer body 12 is rotated by the driving force of the drive roll 30, and the liquid receptive particles 16 are transferred from the supply roll 18 </ b> A of the particle supply apparatus 18 to the surface of the intermediate transfer body 12. Then, the liquid receptive particle layer 16A is formed.

  Next, the liquid receptive particle layer 16A is transported to a position facing the inkjet recording head 20 of each color, and ink droplets of each color based on image information are ejected from the inkjet recording heads 20Y, 20M, 20C, and 20K. As a result, the liquid receptive particle layer 16 </ b> A absorbs ink, and a color image is formed on the surface of the intermediate transfer body 12.

  Next, the transparent liquid 38 </ b> A is discharged from the transparent liquid supply device 38 to the position of the intermediate transfer body 12 to be transferred to the area where the surface gloss of the recording medium P is desired to be improved.

  Next, the liquid receptive particle layer 16 </ b> A is pressure-transferred to the recording medium P by the transfer member 22. At this time, the particles that have received the ink are deformed and adhere to the recording medium P.

  The liquid receptive particle layer 16 </ b> A transferred to the recording medium P is heated and pressurized and fixed to the recording medium P by the fixing device 64.

  In the present embodiment, the supply amount of the transparent liquid 38A is changed with respect to each recording medium P even when the recording medium P is heated at different temperatures and is not contacted with a member having different smoothness. Thus, different degrees of gloss are formed on the surface of each recording medium P.

  Further, by changing the supply amount of the transparent liquid 38A in units of dots, gloss having partially different degrees is formed on the surface of one recording medium P.

  The transparent liquid supply device 38 is arranged on the upstream side in the rotation direction of the intermediate transfer body 12 as viewed from the inkjet recording head 20 and on the downstream side in the rotation direction of the intermediate transfer body 12 as viewed from the particle supply device 18. It may be. Further, the transparent liquid supply device 38 is arranged on the upstream side in the rotation direction of the intermediate transfer body 12 as viewed from the particle supply device 18 and on the downstream side in the rotation direction of the intermediate transfer body 12 as viewed from the removal device 24. The transparent liquid 38 </ b> A may be supplied to the intermediate transfer body 12 before the liquid receptive particles 16 are supplied to the intermediate transfer body 12.

  Further, as shown in FIG. 5, the transparent liquid supply device 38 may be configured to face the recording medium P to which the liquid receptive particles 16 are transferred from the intermediate transfer body 12. That is, in the configuration shown in FIG. 5, the transparent liquid supply device 38 is configured to supply the transparent liquid 38A to the liquid receptive particles 16 transferred from the intermediate transfer body 12 to the recording medium P.

  Here, when the amount of liquid received by the liquid receptive particles 16 increases, the fluidity of the liquid receptive particles 16 increases. However, the transparent liquid 38A is supplied to the liquid receptive particles 16 transferred to the recording medium P. Then, since the fluidity of the liquid receptive particles 16 becomes higher after the transfer, the position of the transfer position when the liquid receptive particles 16 are transferred to the recording medium P as compared with the configuration in which the transparent liquid 38A is supplied before the transfer. Deviation is suppressed.

  Further, the transparent liquid supply device 38 is not limited to the ejection head, and any apparatus that can apply the transparent liquid 38A to the intermediate transfer body 12 may be used. Examples of the transparent liquid supply device 38 that are in contact with the intermediate transfer body 12 include a supply roll that supplies the transparent liquid 38A and a supply blade that supplies the transparent liquid 38A.

  In addition, the supply roll and the supply blade can supply the transparent liquid 38A in one operation over a range wider than at least one ink droplet ejected from the ink jet recording head 20 (range of one dot). It is considered as a configuration. Specifically, the supply roll and the supply blade have a width along the rotation axis direction of the intermediate transfer body 12 that is equal to or larger than the recording area, and with respect to the image recordable area along the rotation axis direction of the intermediate transfer body 12. The transparent liquid 38A is supplied in one operation. In addition, the transparent liquid 38A can be supplied to the entire surface of the recording medium P by one operation by relatively moving the supply roll and the supply blade along the transport direction of the intermediate transfer body 12. In this example, the glossiness of some of the plurality of recording media P to which the transparent liquid 38A is supplied differs from the recording medium P to which the transparent liquid 38A is not supplied.

  Further, examples of the non-contact type that does not contact the intermediate transfer body 12 include a spray device and an ultrasonic sprayer in addition to the ejection head. The spray device and the ultrasonic sprayer can supply the transparent liquid 38 </ b> A in one operation over at least a range wider than the range (one dot range) where one ink droplet ejected from the inkjet recording head 20 lands. Has been.

  In a configuration in which a transparent liquid 38A of a certain amount or more is supplied to a plurality of dots, such as a supply roll or spray, the supply amount is determined in accordance with the dots that require a large supply amount of the transparent liquid 38A. Is done.

  Further, as shown in FIG. 6, the liquid ejection device 11 may have a configuration in which an image is directly formed on the recording medium P without the intermediate transfer body 12. In the configuration shown in FIG. 6, the particle supply device 18, the inkjet recording head 20, the transparent liquid supply device 38, and the fixing device 64 are arranged in this order on the conveyance path of the recording medium P conveyed by the conveyance means 40. .

  The supply process for supplying the transparent liquid 38A to the recording medium P is the same as that for the intermediate transfer body 12.

  According to this configuration, the liquid receptive particles 16 are supplied from the supply roll 18A of the particle supply device 18 to the surface of the recording medium P, and the liquid receptive particle layer 16A is formed.

  Next, the liquid receptive particle layer 16A is transported to a position facing the inkjet recording head 20 of each color, and ink droplets of each color based on image information are ejected from the inkjet recording heads 20Y, 20M, 20C, and 20K. Thereby, the liquid receptive particle layer 16A absorbs the ink, and a color image is formed on the surface of the recording medium P.

  Next, the transparent liquid 38 </ b> A is discharged from the transparent liquid supply device 38 to an area where it is desired to improve the gloss of the surface of the recording medium P.

  The liquid receptive particle layer 16 </ b> A formed on the recording medium P is heat-pressed and fixed on the recording medium P by the fixing device 64.

  According to the configuration shown in FIG. 6, the transparent liquid 38 </ b> A is applied to each recording medium P even if the recording medium P is not heated and contacted by members having different smoothness. By changing the supply amount, gloss of different degrees is formed on the surface of each recording medium P.

  By changing the supply amount of the transparent liquid 38A in units of dots, gloss having partially different degrees is formed on the surface of one recording medium P.

  In the configuration shown in FIG. 6, the surface of the recording medium P becomes smooth by providing the heating roll 64 </ b> A that is a contact member that contacts the recording surface of the recording medium P. Thereby, compared with the case where it does not have a contact member, glossiness improves even if it is a low heating temperature. The contact member that contacts the recording surface of the recording medium P is not essential. Therefore, the heating roll 64A that contacts the non-recording surface of the recording medium P may be eliminated, and a heating roll may be used instead of the pressure roll 64B that contacts the non-recording surface of the recording medium P.

  Also in the configuration shown in FIG. 6, the transparent liquid supply device 38 is upstream in the conveyance direction of the recording medium P when viewed from the inkjet recording head 20 and is downstream in the conveyance direction of the recording medium P when viewed from the particle supply device 18. The structure arrange | positioned at the side may be sufficient. The transparent liquid supply device 38 may be arranged on the upstream side in the transport direction of the recording medium P as viewed from the particle supply device 18, and before the liquid receptive particles 16 are supplied to the recording medium P. The transparent liquid 38A may be supplied to the recording medium P.

  The present invention is not limited to the above-described embodiment, and various modifications, changes, and improvements can be made.

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 11 Liquid discharge apparatus 12 Intermediate transfer body (an example of a transfer body)
16 Liquid Receptive Particles 18 Particle Supply Device 20 Inkjet Recording Head (Example of Liquid Ejecting Unit)
22A Conveying roll (an example of a heating unit)
38A Transparent liquid 38 Transparent liquid supply apparatus 40 Conveying means 64A Heating roll (an example of a heating unit)
P Recording medium

Claims (10)

A liquid discharge section for discharging liquid;
A particle supply device for supplying liquid receptive particles capable of receiving the liquid;
A transfer body that discharges the liquid from the liquid discharge unit and is supplied with the particles from the particle supply device, and transfers the liquid receptive particles that have received the liquid to the surface of the recording medium;
A transparent liquid supply device for supplying a transparent liquid that can be received by the liquid receptive particles according to a target gloss of the recording medium surface;
A heating unit for heating the liquid receptive particles on the recording medium, the liquid received in the liquid receptive particles, and the transparent liquid;
A liquid ejection apparatus comprising: The transparent liquid supply device supplies the transparent liquid to the transfer body,
The transfer body transfers the liquid receptive particles that have received the transparent liquid and the liquid to the surface of the recording medium,
The heating unit heats the liquid receptive particles, the liquid received by the liquid receptive particles, and the transparent liquid when the liquid receptive particles are transferred from the transfer body to the recording medium. Item 2. The liquid ejection device according to Item 1.   The liquid ejection apparatus according to claim 1, wherein the transparent liquid supply apparatus supplies the transparent liquid to the liquid receptive particles transferred from the transfer body to the recording medium. A liquid ejection unit that ejects liquid onto the surface of the recording medium;
A particle supply device for supplying liquid receptive particles capable of receiving the liquid to the surface of the recording medium;
A transparent liquid supply device for supplying a transparent liquid that can be received by the liquid receptive particles to the recording medium according to a target gloss of the surface of the recording medium;
A heating unit for heating the liquid receptive particles supplied to the recording medium, the liquid received by the liquid receptive particles, and the transparent liquid;
A liquid ejection apparatus comprising:   The said transparent liquid supply apparatus can switch the supply amount of the said transparent liquid for every area | region which wants to make the target glossiness with respect to the said one recording medium. Liquid discharge device.   The said transparent liquid supply apparatus supplies the said transparent liquid more than the said other site | part with respect to the area | region where the supply amount of the said liquid is smaller than another site | part in the area | region which wants to make it the target glossiness. 6. The liquid ejection device according to any one of 5 above.   In the transparent liquid supply device, in the region where the gloss is desired to be lower than the target gloss, the sum of the supply amounts of the liquid and the transparent liquid is the liquid and the liquid in the region where the target gloss is desired. The liquid according to claim 6, wherein the transparent liquid is supplied more than the other part to a part where the supply amount of the liquid is smaller than the other part within a range that is less than or equal to the sum of the supply amount with the transparent liquid. Discharge device.   The liquid discharge according to claim 6 or 7, wherein the transparent liquid supply device supplies the transparent liquid so that a sum of a supply amount of the liquid and a supply amount of the transparent liquid to each part is constant. apparatus. The liquid ejection unit ejects liquid droplets,
The said transparent liquid supply apparatus can supply the said transparent liquid by one operation | movement with respect to the range wider than the range where the said one droplet lands. Liquid ejection device. The liquid ejecting apparatus according to claim 1, wherein the liquid is ejected onto the recording medium to form an image.
Conveying means for conveying a recording medium on which an image is formed by the liquid ejection device;
An image forming apparatus comprising:

Images