JP2021088124A - Image forming device - Google Patents

Abstract

To provide an image forming device that can make both suppression of deterioration in image quality due to collapse of active light curing-type ink and suppression of deterioration in fixability due to excessive curing of the active light curing-type ink compatible with each other, when forming an image on various kinds of recording media.SOLUTION: The image forming device is provided, comprising: an ink impartment unit that imparts active light curing-type ink to a surface of an intermediate transfer body; a transfer unit that transfers the imparted ink to a recording medium; and an active light irradiation unit that irradiates the intermediate transfer body with active light transmitting through the intermediate transfer body, from a rear surface side different from the surface with the ink imparted thereto, in the transfer unit. The active light irradiation unit changes energy quantities of the irradiated active light in accordance with characteristics of the recording medium.SELECTED DRAWING: Figure 1

Description

The present invention relates to an image forming apparatus.

Since the inkjet method can produce an image easily and inexpensively, it is applied to various printing fields including special printing such as various printing, marking, fine line formation, and color filter. In particular, the inkjet method is particularly suitable for applications such as forming various images little by little because digital printing is possible without using a plate.

In an image forming apparatus by an inkjet method, an image forming apparatus is known in which an intermediate image is formed on the surface of an intermediate transfer body and then the intermediate image is transferred to a recording medium.

At this time, an intermediate image is formed using an active ray-curable ink that is cured by irradiation with active rays, and when the intermediate transfer body is transferred to a recording medium, the intermediate image is irradiated with active rays to cure the intermediate image. An image forming apparatus is known (Patent Document 1).

Further, at this time, in order to suppress the deterioration of the intermediate transfer body, the ultraviolet rays (activity) irradiated to each divided region at the time of the transfer according to the amount of the active ray-curable ink applied in each divided region in the intermediate image. An image forming apparatus for setting the irradiation energy of a line) is known (Patent Document 2). Further, in order to optimize the image quality that changes depending on the ink permeability of the recording medium, an image forming apparatus that changes the irradiation time of ultraviolet rays according to the ink absorbency of the recording medium is known (Patent Document 3). ).

In addition, in order to keep the quality of the transferred image constant, there is also an image forming apparatus that controls the irradiation amount of the active rays irradiated to cure the intermediate image before the transfer of the recording medium according to the type of the recording medium. It is known (Patent Document 4).

Japanese Unexamined Patent Publication No. 2010-143073 Japanese Unexamined Patent Publication No. 2011-201136 Japanese Unexamined Patent Publication No. 2004-9483 JP-A-2002-283545

The image forming apparatus using the intermediate transfer body has a problem that the active ray-curable ink is crushed by the pressure at the time of transfer and the image quality is deteriorated. On the other hand, if the irradiation amount (energy amount) of the active rays to be irradiated at the time of transfer is increased, the active ray-curable ink is cured and is less likely to be crushed. On the other hand, if the irradiation amount of the active ray is too large, the active ray-curable ink is cured too much, so that the active ray-curable ink cannot penetrate into the recording medium, and the fixability of the image on the recording medium is lowered. It ends up.

As described above, there is a suitable range for the amount of energy of the active ray irradiated at the time of transfer. However, according to the findings of the present inventors, even if the optimum amount of active ray energy is set according to a certain type of recording medium, when the type of recording medium is changed, the active ray curable ink is crushed. In some cases, the suppression of deterioration of image quality and the suppression of deterioration of fixability due to excessive curing of the active ray curable ink are incompatible.

The present invention has been made based on the above findings, and various functions include suppressing deterioration of image quality due to crushing of active ray-curable ink and suppressing deterioration of fixability due to excessive curing of active ray-curable ink. It is an object of the present invention to provide an image forming apparatus compatible with each other when forming an image on various types of recording media.

The above-mentioned problems are the intermediate transfer body, the ink applying section for applying the active ray-curable ink to the surface of the intermediate transfer body, the transfer section for transferring the applied ink to the recording medium, and the transfer section. It has an active ray irradiating portion that irradiates the active ray transmitted through the intermediate transfer member from a back surface side different from the front surface to which the ink is applied, and the active ray irradiating portion has characteristics of the recording medium. Correspondingly, it is solved by an image forming apparatus that changes the amount of energy of the activated line to be irradiated.

The present invention has been made based on the above findings, and according to the present invention, while suppressing deterioration of image quality due to crushing of active ray-curable ink, deterioration of fixability due to excessive curing of active ray-curable ink is also achieved. , An image forming apparatus that can be suppressed regardless of the type of recording medium is provided.

FIG. 1 is a schematic view schematically showing the overall configuration of the image forming apparatus according to the first embodiment. FIG. 2 is a block diagram showing a main functional configuration of the image forming apparatus according to the first embodiment. FIG. 3 is a schematic view showing how the active rays irradiated from the first active ray irradiation unit reach the ink during transfer. FIG. 4 is a flowchart showing an example of an operation example when executing image formation control in the image forming apparatus according to the first embodiment. FIG. 5 is a schematic view schematically showing the overall configuration of the image forming apparatus according to the second embodiment. FIG. 6 is a schematic view schematically showing the overall configuration of the image forming apparatus according to the third embodiment. FIG. 7 is a schematic view schematically showing the overall configuration of the image forming apparatus according to the fourth embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following forms.

[First Embodiment]
FIG. 1 is a schematic view schematically showing the overall configuration of the image forming apparatus 11 according to the first embodiment. Further, FIG. 2 is a block diagram showing a main functional configuration of the image forming apparatus 11.

The paper feed unit 100 includes a paper feed tray 110 for storing the recording medium M, and a medium supply unit 120 for transporting and supplying the recording medium M from the paper feed tray 110 to the image forming unit 200. The medium supply unit 120 includes a ring-shaped belt whose inside is supported by two rollers, and the recording medium M is moved from the paper feed tray 110 by rotating the rollers with the recording medium M placed on the belt. It is conveyed to the image forming unit 200.

Further, the paper feed unit 100 has the same wavelength as the active line irradiated by the first active ray irradiation unit 262 (described later) on the surface of the recording medium arranged on the paper feed tray 110 on which an image is formed. It has an irradiation unit 132 that irradiates the active line, and a measuring unit 134 that measures the amount of energy of the active line that is irradiated from the irradiation unit 132 and reflected on the surface of the recording medium M. In the present embodiment, the control unit 40 (described later) determines the ratio of the energy amount of the active line measured by the measuring unit 134 after being reflected by the surface of the recording medium M to the energy amount of the active line irradiated by the irradiation unit 132. Based on this, the reflectance of the surface of the recording medium M is measured. As described above, in the present embodiment, the irradiation unit 132, the measurement unit 134, and the control unit 40 measure the reflectance of the active line emitted from the first active ray irradiation unit 262 on the recording medium M, that is, the reflectance. Functions as a measuring unit.

The image forming unit 200 includes a transfer unit 210 that transfers the recording medium conveyed from the paper feeding unit 100 to the transfer drum 240, a head unit 220 on which the inkjet head 224 is mounted, and an intermediate transfer body 230 that is an endless belt. The driven rollers 232 and 234 that rotatably stretch the intermediate transfer body 230, the transfer roller 236 as the drive roller, the transfer drum 240 that conveys the recording medium M, and the recording medium M that is conveyed from the transfer drum 240. It includes a delivery unit 250 that sends out to the paper ejection unit 300, and a control unit 40 (see FIG. 2) that controls the entire device.

Further, the image forming apparatus 11 irradiates the ink droplets ejected to the intermediate transfer body 230 with active rays, and records the ink droplets with the first active ray irradiating unit 262 which cures the ink droplets to a predetermined viscosity. A second active ray irradiation unit 264 that irradiates the ink transferred to the medium M with active rays to cure the ink, a cleaning unit 270 that cleans the surface of the intermediate transfer body 230, a transfer roller 236, and a transfer drum 240. A transport drive unit 51 for driving the ink is provided.

The recording medium M includes paper such as plain paper and coated paper, as well as various media such as cloth or sheet-like resin capable of transferring ink droplets that have landed on the surface of the intermediate transfer body 230. Can be used.

The delivery unit 210 delivers the recording medium M conveyed by the medium supply unit 120 of the paper feed unit 100 to the transfer drum 240. The delivery unit 210 is provided at a position between the medium supply unit 120 and the transfer drum 240 of the paper feed unit 100, and one end of the recording medium M conveyed from the medium supply unit 120 is held by the swing arm unit 212 and picked up. , Delivery to the transfer drum 240 via the delivery drum 214.

The head unit 220 ejects ink droplets onto the intermediate transfer body 230 from a nozzle opening provided on the ink ejection surface facing the intermediate transfer body 230 to form an image on the intermediate transfer body 230. The transport drum 240 transports the recording medium M so that the image formed on the intermediate transfer body 230 is transferred to a predetermined position on the recording medium M by the transfer nip NP.

In the image forming apparatus 11 of the present embodiment, the four head units 220 corresponding to the four color inks of yellow (Y), magenta (M), cyan (C), and black (K) rotate the intermediate transfer body 230. They are arranged so as to be arranged at predetermined intervals in the order of Y, M, C, and K colors from the upstream side of the direction (movement direction).

Each head unit 220 includes an inkjet head 224. The inkjet head 224 is provided with a plurality of recording elements each having a pressure chamber for storing ink, a piezoelectric element provided on the wall surface of the pressure chamber, and a nozzle. When a drive signal that deforms the piezoelectric element is input to this recording element, the pressure chamber is deformed due to the deformation of the piezoelectric element, the pressure in the pressure chamber changes, and ink droplets are ejected from a nozzle communicating with the pressure chamber. To do. In this way, the head unit 220 functions as an ink applying portion that applies ink to the surface of the intermediate transfer body 230.

The arrangement range of the nozzles included in the inkjet head 224 in the orthogonal direction covers the width of the recording medium M conveyed by the transfer drum 240 in the orthogonal direction of the region where the image is formed. The head unit 220 is used with its position fixed with respect to the rotation axis of the transport drum 240 when forming an image. That is, the image forming apparatus 11 is a single-pass type inkjet image forming apparatus.

In the present embodiment, as the ink ejected from the inkjet head 224 to the intermediate transfer body 230, an ink having ultraviolet curability that is cured by being irradiated with ultraviolet rays, more specifically, an activity supplied to the intermediate transfer body 230. An ink whose viscosity changes according to the amount of rays (the amount of ultraviolet rays (UV: inkjet) output from the first active ray irradiation unit 262) is used. An ink having a property that the viscosity increases as the amount of light emitted from the first active ray irradiating unit 262 increases, is used. That is, the image forming portion of the image forming apparatus 11 adopts a UV curable inkjet method.

The intermediate transfer body 230 is bridged between the driven rollers 232 and 234 arranged above and the transfer rollers 236 (drive rollers) arranged below, and the transfer motor (not shown) of the transport drive unit 51 (not shown). Is transmitted to the transfer roller 236 to rotate (move) in the clockwise direction in FIG. 1 (in the direction of the arrow shown in the intermediate transfer body 230 in FIG. 1).

In the present embodiment, the intermediate transfer body 230 has transparency to the active rays irradiated by the first active ray irradiation unit 262, and has an elastic layer of silicon rubber and a polyimide (PI) on a polyimide (PI) base material. It is an endless belt in which the surface layer of) and is laminated. Further, as the transfer roller 236, for example, a rubber roller having a diameter of 100 mm and a rubber thickness of 10 mm on the surface layer is used. The material of the base material, the elastic layer and the surface layer is not limited to these, and for example, a stainless steel material may be used for the base material, or a resin other than the above may be used for the base material, the elastic layer and the surface layer. May be good.

In the image forming apparatus 11, the intermediate transfer body 230 is clocked by driving the transfer motor based on the control signal of the control unit 40 and rotating the transfer roller 236 (transfer unit) in the clockwise direction in FIG. It is driven to rotate in the circumferential direction.

The transport drum 240 is around a rotation axis extending in a direction perpendicular to the drawing of FIG. 1 (hereinafter, referred to as “orthogonal direction”) while holding the recording medium M on a cylindrical outer peripheral curved surface (convey surface). The recording medium M is transported in the transport direction along the transport surface (in the direction of the arrow shown in the transport drum 240 in FIG. 1). In the present embodiment, in the transport drum 240, when the slits are formed discontinuously and the recording medium M is not arranged on the transport drum 240, the active rays from the first active ray irradiation unit 262 make the slits. It is structured so that it can pass through.

Specifically, the transfer drum 240 includes a transfer drum motor (not shown), and the transfer drum motor is driven by the control of the control unit 40 to rotate in the counterclockwise direction in FIG. In the present embodiment, a large-sized (for example, triple cylinder for a printing machine) metal drum is used as the transport drum 240.

The transfer roller 236 is arranged inside the intermediate transfer body 230 at a position facing the transfer drum 240 across the belt, and pressurizes the transfer drum 240 via the intermediate transfer body 230. Further, the transfer drum 240 is pressed against the transfer roller 236 with the intermediate transfer body 230 interposed therebetween to form a transfer nip NP that transfers an image from the intermediate transfer body 230 to the recording medium M.

The first active ray irradiation unit 262 is arranged on the back surface side of the intermediate transfer body 230, and under the control of the control unit 40, the ink droplets ejected on the intermediate transfer body 230 are sandwiched and pressed (nip) in the transfer nip NP. At the same time, the ink droplets are irradiated with active rays to semi-cure the ink droplets. In the present specification, the front surface of the intermediate transfer body 230 means a surface to which ink is applied, transported and transferred, and the back surface of the intermediate transfer body 230 is a surface to which ink is applied. It means a different, opposite surface via the body of the intermediate transfer material 230.

In FIG. 1, the dotted arrow extending from the first active line irradiation unit 262 indicates an active line that is irradiated from the back surface side of the intermediate transfer body 230 with respect to the ink droplets ejected on the intermediate transfer body 230. As shown in FIG. 1, the first active ray irradiating unit 262 irradiates the ink with the active rays transmitted through the transfer roller 236 and the intermediate transfer body 230 in this order from the back surface side of the intermediate transfer body 230. Further, the first active ray irradiation unit 262 is irradiated from the downstream side in the traveling direction of the intermediate transfer body 230 with respect to the direction in which the irradiated active line is perpendicular to the surface of the intermediate transfer body 230 in the transfer roller 236. Placed in position.

The second active ray irradiation unit 264 is arranged so as to irradiate the recording medium M transported to the downstream side of the transfer nip NP with the active rays, and is transferred by the transfer nip NP under the control of the control unit 40. This cures the image (ink droplets).

The cleaning unit 270 is arranged to face the surface of the intermediate transfer body 230 between the driven roller 232 and the transfer roller 236 (drive roller) in the moving direction (rotation direction) of the intermediate transfer body 230, and the surface of the intermediate transfer body 230 is covered. Equipped with a dry web (web roller) for cleaning.

The dry web of the cleaning unit 270 is configured to be rotatable and rotatable with respect to the intermediate transfer body 230, and is rotated by contacting with the intermediate transfer body 230 under the control of the control unit 40. The surface of the intermediate transfer body 230 is cleaned to remove foreign substances (transfer residue and unnecessary ink and paper dust due to mist) adhering to the surface.

The delivery unit 250 has a belt loop 252 having a ring-shaped belt whose inside is supported by two rollers, and a cylindrical transfer drum 251 that transfers the recording medium M from the transfer drum 240 to the belt loop 252. The recording medium M delivered from the transport drum 240 onto the belt loop 252 by the delivery drum 251 is conveyed by the belt loop 252 and sent to the paper ejection unit 300.

The paper ejection unit 300 has a plate-shaped paper ejection tray 310 on which the recording medium M sent out from the image forming unit 200 by the delivery unit 250 is placed.

Next, other main functional configurations in the image forming apparatus 11 will be described mainly with reference to FIG. The image forming apparatus 11 includes a head drive unit 222 and an inkjet head 224 included in the head unit 220, a control unit 40, a transport drive unit 51, and an input / output interface 52.

The head drive unit 222 outputs a drive signal for deforming the piezoelectric element according to the image data to the recording element of the inkjet head 224 based on the control of the control unit 40, thereby causing the inkjet head 224 to perform a deforming operation. An amount of ink droplets corresponding to the pixel value of the image data is ejected from the nozzle.

The control unit 40 includes a CPU 41 (Central Processing Unit), a RAM 42 (Random Access Memory), a ROM 43 (Read Only Memory), and a storage unit 44.

The CPU 41 reads various control programs (for example, an image formation condition changing program) and setting data stored in the ROM 43 and stores them in the RAM 42, and executes the programs to perform various arithmetic processes. Further, the CPU 41 controls the overall operation of the image forming apparatus 11 in an integrated manner.

The RAM 42 provides the CPU 41 with a working memory space and stores temporary data. The RAM 42 may include a non-volatile memory.

The ROM 43 stores various control programs, setting data, and the like executed by the CPU 41. Instead of the ROM 43, a rewritable non-volatile memory such as an EEPROM (Electrically Erasable Programmable Read Only Memory) or a flash memory may be used.

A print job (specifically, an image formation instruction including various user setting information such as the number of prints) input from the external device 20 via the input / output interface 52 and an image related to the print job are stored in the storage unit 44. Data is stored. As the storage unit 44, for example, an HDD (Hard Disk Drive) may be used, or a DRAM (Dynamic Random Access Memory) or the like may be used in combination.

The transfer drive unit 51 supplies a drive signal to the transfer drum motor of the transfer drum 240 based on the control signal supplied from the control unit 40 to rotate the transfer drum 240 at a predetermined speed and timing. Further, the transport drive unit 51 supplies a drive signal to the motor of the transfer roller 23 based on the control signal supplied from the control unit 40, and rotates the intermediate transfer body 230 at a predetermined speed and timing.

The input / output interface 52 operates as an input receiving unit and an output unit, is connected to the input / output interface of the external device 20, and mediates the transmission and reception of data between the external device 20 and the control unit 40. The input / output interface 52 is composed of, for example, any of various serial interfaces, various parallel interfaces, or a combination thereof.

The external device 20 is, for example, a personal computer, and supplies print jobs, image data, and the like to the control unit 40 via the input / output interface 52.

By the way, in an image forming apparatus that semi-cures ink by irradiating active rays during transfer to a recording medium in this way, to what extent should the ink be cured (thickened) by irradiating the active rays during transfer? Is a problem. That is, if the ink is not sufficiently cured at the time of transfer, the ink is crushed and the dots are spread when passing through the transfer nip NP, and it is difficult to form an image having desired fineness. On the other hand, if the ink is excessively cured (thickened) during transfer, it becomes difficult for the ink to penetrate into the recording medium during transfer, and the fixability of the ink to the recording medium may be poor.

In view of the problems of the prior art, the present inventors have conducted diligent research and various experiments. As a result, by changing the amount of energy of the active rays to be irradiated at the time of transfer according to the characteristics of the recording medium, it is possible to suppress the crushing of the ink at the time of transfer and at the same time sufficiently secure the fixability to the recording medium. It was found that the ink can be semi-cured.

Therefore, in the present embodiment, the amount of energy of the active rays irradiated from the first active ray irradiation unit 262 is changed according to the reflectance of the surface of the recording medium to which the ink is transferred.

FIG. 3 is a schematic view showing how the active rays irradiated from the first active ray irradiation unit 262 reach the ink during transfer. When the irradiated active line reaches the back surface 230a of the intermediate transfer body 230 (active line R1), the irradiated active line advances inside the intermediate transfer body 230 while being attenuated according to the transmittance of the intermediate transfer body 230, and the intermediate transfer is performed. It reaches the ink layer 226 formed by applying ink to the surface 230b of the body (active line R2). The active line that has reached the ink layer 226 travels inside the ink layer 226 while being absorbed (attenuated) by the ink layer 226, and reaches the surface 226a of the recording medium M to which the ink layer 226 is transferred (while being attenuated). Active line R3). At this time, the ink is cured according to the amount of active rays absorbed by the ink layer 226. Further, the active line that has passed through the inside of the ink layer 226 and reached the surface 226a of the recording medium M is reflected by the surface 226a of the recording medium M and returned to the inside of the ink layer 226 (active line R4), and is returned to the inside of the ink layer 226 (active line R4). It travels inside the ink layer 226 while being absorbed (attenuated) by the 226.

In this way, the active line R3 that travels inside the intermediate transfer body 230 and reaches the ink layer 226 and is reflected by the surface 226a of the recording medium M after traveling inside the ink layer 226 on the ink layer 226. Both the active line R4 returned to the inside of the ink layer 226 and the ink layer 226 are applied, and the ink layer 226 is cured by these two active lines. Therefore, if the reflectance of the active line irradiated from the first active ray irradiation unit 262 on the surface 226a of the recording medium M is small, the amount of energy of the active line applied to the ink layer 226 becomes smaller, and the ink layer 226 becomes smaller. Is more difficult to cure (thicken), so the ink is likely to be crushed during transfer. On the other hand, if the reflectance of the active rays irradiated from the first active ray irradiation unit 262 on the surface 226a of the recording medium M is large, a larger amount of active rays will be imparted to the ink layer 226, and the ink layer 226 becomes harder and hardens (thickens), and the fixability to the recording medium M tends to decrease.

On the other hand, in the present embodiment, when the reflectance of the active line irradiated from the first active ray irradiation unit 262 on the surface 226a of the recording medium M is small, the active line irradiated from the first active ray irradiation unit 262. Increase the amount of energy in. Further, when the reflectance of the active line irradiated from the first active ray irradiation unit 262 on the surface 226a of the recording medium M is large, the amount of energy of the active line irradiated from the first active ray irradiation unit 262 is further reduced. .. As a result, the variation in the hardness (viscosity) of the semi-cured ink due to the magnitude of the reflectance on the surface 226a of the recording medium M is suppressed, and the image quality due to the crushing of the active ray-curable ink is suppressed regardless of the type of the recording medium. It is possible to achieve both suppression of deterioration and suppression of deterioration of fixability due to excessive curing of the active ray curable ink.

Table 1 shows the first active ray irradiation unit 262 when an image is formed on four types of recording media (recording media A to recording medium D) having different reflectances of the active rays emitted from the first active ray irradiation unit 262. It is a simulation result which shows how to change the energy amount of the active ray which irradiates from. In Table 1, the transmittance of the active line of the intermediate transfer member 230 is 99.5%, the transmittance of the active line in the ink layer 226 is 50%, and the recording medium A, the recording medium B, the recording medium C, and the recording medium are recorded. The transmittances of the active rays on the surface 226a of the medium D are 60.0%, 70.0%, 50.0%, and 40.0%, respectively. Further, Table 1 shows the energy amounts (units) of the active lines R1, R2, R3 and R4 when the energy amount of the active line R1 irradiated from the first active line irradiation unit 262 is changed according to the recording medium. : W / cm ² ) is shown. At this time, the energy amount of the active line R1 is adjusted so that the energy amount (R2 + R4) of the active line irradiated to the ink layer 226 is substantially the same.

As shown in Table 1, the energy of the active line R1 irradiated from the first active ray irradiation unit 262 according to the reflectance of the active line irradiated from the first active ray irradiation unit 262 on the surface 226a of the recording medium M. By changing the amount, the energy amount (R2 + R4) of the active line irradiated to the ink can be made substantially the same. As a result, regardless of the type of the recording medium M, the amount of energy of the active rays irradiated to the ink layer 226 is made substantially the same, and the hardness (viscosity) of the ink when passing through the transfer nip NP is made substantially the same. Regardless of which recording medium is used, the ink can be semi-cured to such an extent that crushing of the ink during transfer can be suppressed and at the same time sufficient fixability to the recording medium can be ensured.

Next, an operation example when executing the image formation control (image forming method) in the image forming apparatus 11 will be described. FIG. 4 is a flowchart showing an example of an operation example when the image formation control in the image forming apparatus 11 is executed. The process shown in FIG. 4 is appropriately executed when the control unit 40 receives the print job execution command.

First, a person (operator) who intends to form an image operates an external device to include image data indicating an image to be formed and recording medium data indicating selection or setting of a recording medium to form an image. The print job is transmitted to the image forming apparatus 11. The transmitted print job is received by the input / output interface 52 and stored in the storage unit 44.

After that, the reflectance measuring unit measures the reflectance of the surface to which the ink is applied of the recording medium designated by the print job (step S110). The measured reflectance data is stored in the storage unit 44.

Next, the control unit 40 determines the amount of energy of the active line irradiated from the first active ray irradiation unit 262 based on the reflectance data measured by the reflectance measuring unit and stored in the storage unit 44. .. At this time, in the control unit 40, the amount of energy of the active rays applied to the ink according to the reflectance of the recording medium suppresses the crushing of the ink during transfer, and at the same time, the fixing property to the recording medium is sufficiently sufficient. The amount of energy of the active rays irradiated from the first active ray irradiation unit 262 is determined so that the amount of energy for semi-curing the ink can be secured (see step S120, Table 1).

After that, the control unit 40 forms an image on the surface of the conveyed recording medium M (step S130).

Specifically, the control unit 40 operates the transport drive unit 51 to rotate the intermediate transfer body 230, and operates the head unit 220 to form an intermediate image on the surface of the intermediate transfer body 230. The shape of the intermediate image to be formed is determined based on the image data included in the print job.

Then, the control unit 40 operates the first active ray irradiation unit 262 to activate the intermediate image transferred from the paper feeding unit 100 to the recording medium M conveyed via the transfer unit 210 at the transfer nip NP. Irradiate the lines to semi-cure the ink that makes up the intermediate image. The energy amount of the active ray irradiated at this time is the energy amount determined by the control unit 40 in the step S120.

Further, the control unit 40 operates the second active ray irradiation unit 264 to irradiate the image transferred to the recording medium M with active rays, and mainly cures the ink constituting the transferred image. The recording medium M on which the image is formed in this way is sent to the paper ejection unit 300 via the delivery unit 250 and is ejected to the paper ejection tray 310.

According to the present embodiment configured in this way, the energy of the active rays irradiated from the first active ray irradiating unit 262 to the ink at the time of transfer according to the reflectance of the surface 226a on which the ink of the recording medium M is transferred. The amount is changed. At this time, the first active ray irradiation unit 262 adds the sum of the energy amount of the active ray transmitted through the intermediate transfer body 230 and the energy amount of the active ray reflected on the surface 226a on which the ink of the recording medium M is transferred. , The amount of energy of the activated line to be irradiated is changed so as to be constant regardless of the recording medium. As a result, the change in the hardness of the ink during transfer due to the magnitude of the energy amount of the active line reflected on the surface 226a of the recording medium M is suppressed, and the crushing of the ink during transfer is suppressed regardless of the recording medium. At the same time, the ink can be semi-cured to such an extent that the fixability to the recording medium can be sufficiently ensured.

In the present embodiment, the reflectance of the recording medium is measured by the paper feeding unit 100, but the reflectance of the recording medium may be measured while being conveyed from the paper feeding unit 100 to the transfer nip NP.

In this embodiment, the reflectance of the recording medium is measured by the paper feed unit 100, but as in the third embodiment described later, the transmission amount measuring unit arranged inside the transport drum 240 and the recording medium. The reflectance of the recording medium may be measured by a reflection amount measuring unit arranged at a position reaching the active line reflected (diffused) on the surface of M.

Further, in the present embodiment, the amount of energy of the active line irradiated from the first active ray irradiation unit 262 to the ink at the time of transfer is changed according to the reflectance of the recording medium measured by the paper feed unit 100. However, the amount of energy of the active rays emitted from the first active ray irradiation unit 262 according to the type of the recording medium M may be determined in advance and stored in the storage unit 44. At this time, the control unit 40 changes the energy amount of the active line emitted from the first active line irradiation unit 262 with reference to the storage unit 44 according to the recording medium data included in the print job, as described above. The operation of the image forming apparatus 11 may be controlled as in the embodiment.

[Second Embodiment]
FIG. 5 is a schematic view schematically showing the overall configuration of the image forming apparatus 12 according to the second embodiment.

The image forming apparatus 12 has the image forming apparatus 11 according to the first embodiment in that the conveying drum 240 has a temperature adjusting unit 510 for adjusting the temperature of the surface to which the ink of the recording medium M is applied. Is different. Since the other configurations of the present embodiment are the same as those of the image forming apparatus 11 according to the first embodiment, duplicate description will be omitted.

The temperature adjusting unit 510 can be a known heating source (heater). The temperature of the heating source is controlled by the control unit 40. The transport drum 240 is heated by the heating source, and the heat from the transport drum 240 is conducted to the recording medium M, whereby the surface of the recording medium M to which the ink is applied is adjusted to a predetermined temperature.

The permeability of ink to a recording medium also changes depending on the material and surface condition of the recording medium. In order to cope with this change in permeability, for example, in order to sufficiently fix the ink on a recording medium having low permeability, the amount of energy of the active ray irradiated from the first active ray irradiation portion is reduced to increase the viscosity of the ink at the time of transfer. If you try to lower it, the ink will easily collapse during transfer. On the other hand, if the amount of energy of the active rays is increased in order to suppress the crushing of the ink, the ink cannot be sufficiently fixed on the recording medium having low permeability.

On the other hand, in the present embodiment, in addition to adjusting the hardness (viscosity) of the ink at the time of transfer, the permeability of the ink is adjusted by changing the temperature of the recording medium, so that it depends on the type of recording medium. Changes in ink fixability can be suppressed.

In the present embodiment, the amount of heat for heating the recording medium M may be determined in advance from the temperature adjusting unit 510 according to the type of the recording medium M and stored in the storage unit 44. At this time, the control unit 40 changes the amount of heat for heating the recording medium M from the temperature adjusting unit 510 with reference to the storage unit 44 according to the recording medium data included in the print job. The operation of the image forming apparatus 12 may be controlled in the same manner as in the first embodiment.

In this embodiment, in order to directly or indirectly detect the surface temperature of the recording medium M, a temperature sensor (for example, a thermistor) (not shown) is provided in the vicinity of the transport drum 240, and is based on the temperature detected by the temperature sensor. The feedback control of the temperature adjusting unit 510 may be performed. That is, when the surface temperature of the recording medium M detected by the temperature sensor deviates from the target temperature, the control unit 40 increases or decreases the amount of heat from the temperature adjusting unit 510 so as to adjust the surface temperature of the recording medium M to the target temperature. You may.

According to the present embodiment configured as described above, by changing the surface temperature of the recording medium M, the permeability of the ink can be further adjusted depending on the type of the recording medium M, so that the ink is suppressed from being crushed during transfer. And ensuring the fixability on the recording medium can be more highly compatible.

[Third Embodiment]
FIG. 6 is a schematic view schematically showing the overall configuration of the image forming apparatus 13 according to the third embodiment.

The image forming apparatus 13 has a transmission amount measuring unit 610 for measuring the amount of energy of the active rays irradiated from the first active ray irradiating unit 262 after being transmitted through the intermediate transfer body 230, and a transmission amount measuring unit 610 after passing through the intermediate transfer body 230. The image forming apparatus 11 according to the first embodiment and the image forming apparatus 12 according to the second embodiment are provided with a reflection amount measuring unit 620 for measuring the energy amount of the active rays reflected by the recording medium. Is different. Since the other configurations of the present embodiment are the same as those of the image forming apparatus 11 according to the first embodiment or the image forming apparatus 12 according to the second embodiment, duplicate description will be omitted.

The permeation amount measuring unit 610 is arranged at a position where the active line irradiated from the first active line irradiation unit 262 passes through the intermediate transfer body 230 and reaches after passing through the slit of the transport drum 240. It can be a sensor that measures the amount of energy (such as a light receiving sensor). In the present embodiment, the control unit 40 is the ratio of the energy amount of the active line measured by the transmission amount measuring unit 610 after passing through the intermediate transfer body 230 to the energy amount of the active line irradiated by the first active ray irradiation unit 262. The transmittance of the intermediate transfer material 230 is measured based on the above. As described above, in the present embodiment, the transmittance measuring unit 610 and the control unit 40 measure the transmittance of the active rays emitted from the first active ray irradiation unit 262 of the intermediate transfer body 230. Functions as.

The reflection amount measuring unit 620 reflects (diffuses) the active rays emitted from the first active ray irradiation unit 262 on the surface of the recording medium M which is transmitted through the intermediate transfer body 230 and is arranged on the transport drum 240. ), It can be a sensor (light receiving sensor, etc.) that measures the amount of energy of the active ray, which is placed at a position to reach.

In the present embodiment, the control unit 40 refers to the amount of energy transmitted through the intermediate transfer body 230 according to the transmittance obtained by the transmittance measuring unit among the amount of energy of the active rays irradiated by the first active ray irradiation unit 262. , The reflectance of the recording medium M is measured based on the ratio of the energy amount of the active ray measured by the reflectance measuring unit 620. As described above, in the present embodiment, the reflection amount measuring unit 620 and the control unit 40 serve as the reflectance measuring unit that measures the reflectance of the active rays emitted from the first active ray irradiating unit 262 of the recording medium M. Function.

Here, as described above, the active rays irradiated from the first active ray irradiation unit 262 pass through the intermediate transfer body 230 and reach the ink. At this time, if the intermediate transfer body 230 deteriorates due to use or the surface of the intermediate transfer body 230 is scratched and the transmittance of the intermediate transfer body decreases, the amount of active rays reaching the ink also decreases. However, the desired amount of active rays described above may not reach the ink at the time of transfer.

On the other hand, in the present embodiment, the transmittance of the intermediate transfer member 230 is measured, and when the transmittance of the intermediate transfer member 230 is lower, the amount of energy of the active line irradiated from the first active ray irradiation unit 262 is increased. Do more. As a result, a desired amount of active rays can reach the ink at the time of transfer regardless of the change in the transmittance of the intermediate transfer body 230.

Tables 2 to 5 show the first active ray irradiation according to the transmittance of the intermediate transfer medium 230 when forming an image on the four types of recording media (recording media A to recording medium D) shown in Table 1. It is a simulation result which shows how to change the energy amount of the active ray which irradiates from a part 262. Tables 2 to 5 show that the transmittances of the active rays of the intermediate transfer medium 230 are 99.5% (same as Table 1), 95.0%, and 90.0 for each of the recording media A to D, respectively. The amount of energy of the active line R1 to be irradiated is shown in%. As in Table 1, the transmittance of the active rays in the ink layer 226 is 50%, and the reflectances of the active rays on the surfaces of the recording medium A, the recording medium B, the recording medium C, and the recording medium D are respectively. , 60.0%, 70.0%, 50.0%, 40.0%. Further, Tables 2 and 5 show the active lines R1, R2, and R3 when the amount of energy of the active line R1 irradiated from the first active line irradiation unit 262 is changed according to the recording medium, as in Table 1. And the respective energy amounts of R4 are shown. At this time, the energy amount of the active line R1 is adjusted so that the energy amount (R2 + R4) of the active line irradiated to the ink layer 226 is substantially the same.

As shown in Tables 2 to 5, of the active line R1 irradiated from the first active ray irradiation unit 262 according to the transmittance of the active line irradiated from the first active ray irradiation unit 262 of the intermediate transfer body 230. By further changing the amount of energy, the amount of energy (R2 + R4) of the active rays irradiated to the ink can be made substantially the same regardless of the state such as deterioration of the intermediate transfer body. As a result, regardless of the type of the recording medium M and the transmittance of the intermediate transfer medium, the amount of energy of the active rays irradiated to the ink layer 226 is substantially the same, and the hardness (viscosity) of the ink when passing through the transfer nip NP is made substantially the same. ) Are substantially the same, so that when any recording medium is used, the ink is semi-cured to the extent that the ink is suppressed from being crushed during transfer and at the same time the ink is sufficiently fixed to the recording medium. Can be done.

(Modified example of the third embodiment)
In the third embodiment, the image forming apparatus 13 includes a transmission amount measurement unit 610 and a reflection amount measurement unit 620, and the transmission of the intermediate transfer member 230 is based on the energy amount of the active ray measured by the transmission amount measurement unit 610. He was trying to find a rate.

By the way, the degree of deterioration of the intermediate transfer body 230 due to use and the degree of occurrence of scratches on the surface of the intermediate transfer body 230 are substantially proportional to the amount of use of the image forming apparatus 13 (mileage of the intermediate transfer body 230). Therefore, in the image forming apparatus 13, the control unit 40 may change the amount of energy of the active line irradiated from the first active line irradiation unit 262 according to the mileage data of the intermediate transfer body 230. At this time, the control unit 40 acquires the mileage of the intermediate transfer body and stores it in the storage unit 44, and when the storage unit 44 determines the amount of energy of the active line to be irradiated from the first active line irradiation unit 262, the storage unit 44 The amount of energy of the active line may be determined according to the mileage data with reference to the mileage data of the intermediate transfer body 230 stored.

According to the present embodiment configured as described above, the intermediate transfer body is further changed in the amount of energy of the active line irradiated from the first active line irradiation unit 262 according to the transmittance of the active line of the intermediate transfer body 230. Regardless of the state such as deterioration of 230, it is possible to achieve a higher degree of compatibility between suppressing ink crushing during transfer and ensuring fixability on a recording medium.

[Fourth Embodiment]
FIG. 7 is a schematic view schematically showing the overall configuration of the image forming apparatus 14 according to the fourth embodiment.

The image forming apparatus 14 captures an intermediate image formed on the surface of the intermediate transfer body 230 by applying ink from the head unit 220 between the head unit 220 and the transfer nip NP of the intermediate transfer body 230. It differs from the image forming apparatus 11 according to the first embodiment, the image forming apparatus 12 according to the second embodiment, and the image forming apparatus 13 according to the third embodiment in that it has an image pickup unit 710. Since the other configurations are the same as the image forming apparatus 11 according to the first embodiment, the image forming apparatus 12 according to the second embodiment, or the image forming apparatus 13 according to the third embodiment in the present embodiment. Duplicate explanations will be omitted.

The intermediate image imaging unit 710 can be a known image sensor or the like capable of capturing an intermediate image. Then, in the present embodiment, the control unit 40 obtains the hiding rate of the intermediate image with ink based on the image obtained by the intermediate image imaging unit 710 capturing the intermediate image. As described above, in the present embodiment, the intermediate image imaging unit 710 and the control unit 40 function as a concealment rate measuring unit that measures the concealment rate of the intermediate image formed on the intermediate transfer body 230 by the ink.

Here, as described above, the active rays irradiated from the first active ray irradiation unit 262 pass through the intermediate transfer body 230 and the ink layer, and then are reflected by the surface of the recording medium M and returned to the inside of the ink layer. Is done. At this time, the larger the hiding ratio of the intermediate image, the smaller the amount of active rays that are transmitted through the intermediate transfer body 230 and then reflected on the surface of the recording medium M and returned to the inside of the ink layer. Therefore, the amount of energy of the active line received by the ink at the time of transfer may change according to the concealment rate of the intermediate image, and the ink at the time of transfer may not receive the desired amount of the active line described above.

On the other hand, in the present embodiment, the hiding rate of the intermediate image is measured, and when the hiding rate of the intermediate image is higher, the energy amount of the active line irradiated from the first active line irradiation unit 262 is increased. When the concealment rate of the intermediate image is lower, the amount of energy of the active line irradiated from the first active line irradiation unit 262 is made smaller. As a result, a desired amount of active rays can be received by the ink at the time of transfer regardless of the change in the hiding ratio of the intermediate image.

In Tables 6 to 7, when an image is formed on the four types of recording media (recording media A to recording medium D) shown in Table 1, the first active ray irradiation is performed according to the hiding rate of the intermediate image by the ink. It is a simulation result which shows how to change the energy amount of the active ray which irradiates from a part 262. Tables 6 to 7 show that for each of the recording media A to D, the hiding rate of the intermediate image by the ink is a value such that the absorption rates of the active rays reaching the ink layer are 20% and 80%, respectively. The amount of energy of the active line R1 to be irradiated is shown. As in Table 1, the transmittance of the active line of the intermediate transfer member 230 is 99.5%, and the reflectance of the active line on the surfaces of the recording medium A, the recording medium B, the recording medium C, and the recording medium D. Are 60.0%, 70.0%, 50.0%, and 40.0%, respectively. Further, Tables 6 to 7 show the active lines R1, R2, and R3 when the amount of energy of the active line R1 irradiated from the first active line irradiation unit 262 is changed according to the recording medium, as in Table 1. And the respective energy amounts of R4 are shown. At this time, the energy amount of the active line R1 is adjusted so that the energy amount (R2 + R4) of the active line irradiated to the ink layer 226 is substantially the same.

As shown in Tables 6 to 7, intermediate transfer is performed by further changing the amount of energy of the active line R1 irradiated from the first active line irradiation unit 262 according to the hiding rate (absorption rate) of the intermediate image by the ink. The amount of energy (R2 + R4) of the active rays irradiated to the ink can be made substantially the same regardless of the state such as deterioration of the body. As a result, regardless of the type of the recording medium M and the reflectance of the intermediate image, the amount of energy of the active rays irradiated to the ink layer 226 is substantially the same, and the hardness (viscosity) of the ink when passing through the transfer nip NP is increased. By making them substantially the same, it is possible to semi-cure the ink to the extent that it is possible to suppress the crushing of the ink during transfer and at the same time sufficiently secure the fixability on the recording medium regardless of which recording medium is used. ..

According to the present embodiment configured as described above, the intermediate transfer member 230 is deteriorated by further changing the amount of energy of the active line irradiated from the first active line irradiation unit 262 according to the hiding rate of the intermediate image by the ink. Regardless of such conditions, it is possible to achieve a higher degree of compatibility between suppressing ink crushing during transfer and ensuring fixability on a recording medium.

At this time, the intermediate image imaging unit 710 may divide the surface of the intermediate transfer body 230 into a large number of small regions and obtain the hiding rate by ink for each of the small regions. Further, the first active ray irradiating unit 262 may be used as an LED array or the like, and the amount of energy of the active ray irradiating the small area may be changed according to the concealment rate measured for each small area.

In the above-described embodiment, the image forming apparatus 14 is provided with the intermediate image imaging unit 710, and the hiding rate of the intermediate image is obtained based on the image of the intermediate image captured by the intermediate image imaging unit 710. On the other hand, the control unit 40 as the concealment rate measuring unit may obtain the concealment rate of the intermediate image based on the image data included in the print job.

According to the present embodiment configured as described above, the intermediate transfer member 230 is deteriorated by further changing the amount of energy of the active line irradiated from the first active line irradiation unit 262 according to the hiding rate of the intermediate image by the ink. Regardless of such conditions, it is possible to achieve a higher degree of compatibility between suppressing ink crushing during transfer and ensuring fixability on a recording medium.

[Other Embodiments]
It should be noted that each of the above embodiments is merely an example of embodiment of the present invention, and the technical scope of the present invention should not be construed in a limited manner by the above embodiments. The present invention can be practiced in various forms without departing from its gist or its main features.

For example, in each of the above embodiments, an image forming apparatus for applying ink to an intermediate transfer body by an inkjet method has been described, but the method for applying ink is not limited to the inkjet method, and other methods using a roll coater, a bar coater, or the like are used. It may be a method.

1-1. Measurement of Transmittance of Intermediate Transfer A commercially available transparent polyimide film was used as the intermediate transfer. The transmittance of ultraviolet rays having a wavelength of 395 nm of this transparent polyimide film was measured using a spectrophotometer "UV-2550" (manufactured by Shimadzu Corporation) and found to be 99.5%.

1-2. Preparation of active ray-curable ink An active ray-curable ink was prepared by the following procedure.

(Preparation of pigment dispersion)
Pigment dispersant (Ajinomoto PB824, manufactured by Ajinomoto Fine-Techno Co., Ltd., "Ajinomoto" is a registered trademark of Ajinomoto Co., Inc.) 9.0 parts by mass and active ray-polymerizable compound (tripropylene glycol diacrylate) 70.0 parts by mass. , 0.02 parts by mass of a polymerization inhibitor (Irgastab UV10, manufactured by BASF, "Irgastab" is a registered trademark of the same company), was placed in a stainless beaker, and heated and stirred for 1 hour while heating on a hot plate at 65 ° C.

After cooling the above mixed solution to room temperature, 21.0 parts by mass of Pigment Red 122 (Chromofine Red 6112JC manufactured by Dainichiseika Kogyo Co., Ltd.) was added thereto. The mixed solution was placed in a glass bottle together with 200 g of zirconia beads having a diameter of 0.5 mm, sealed, and dispersed with a paint shaker for 8 hours. Then, the zirconia beads were removed to obtain a pigment dispersion liquid.

(Preparation of active ray curable ink)
Gelling agent "Lunac BA" (behenic acid, manufactured by Kao Co., Ltd., "Lunac" is a registered trademark of the company) 5.0% by mass and active ray-polymerizable compound (polyethylene glycol # 400 diacrylate) 29.9% by mass 6EO-modified trimethylolpropane triacrylate 23.0% by mass, 4EO-modified pentaerythritol tetraacrylate 15.0% by mass, and the first polymerization initiator "IRGACURE 819" (BASF, "IRGACURE" is BASF). (Registered trademark) 8.0% by mass, surfactant "KF-352" (manufactured by Shin-Etsu Chemical Industry Co., Ltd.) 0.1% by mass, and pigment dispersion 19.0% by mass were placed in a stainless steel beaker. The mixture was stirred for 1 hour while heating on a hot plate at 80 ° C. The obtained solution was filtered through a Teflon (registered trademark) 3 μm membrane filter manufactured by ADVATEC while heating to obtain an active ray-curable ink.

(Formation of solid image 1)
The active ray-curable ink was loaded into the image forming apparatus having the configuration shown in FIG. 1 to form a solid image 1 having 360 dpi and a concealing rate of 50%. The active rays emitted from the first active ray irradiation unit were ultraviolet rays having a wavelength of 395 nm, and the amount of energy was 1.000 W / cm ² . The active rays emitted from the second active ray irradiation unit were ultraviolet rays having a wavelength of 395 nm, and the amount of energy was adjusted to the amount at which the ink was completely cured. Coated paper A was used as the recording medium. The reflectance of ultraviolet rays having a wavelength of 395 nm of this recording medium measured by the reflectance measuring unit was 60%.

(Formation of solid image 2)
The solid image 2 was formed in the same manner as the solid image 1 except that the coated paper B was used as the recording medium and the hiding rate of the image was set to 20%. The reflectance of ultraviolet rays having a wavelength of 395 nm of this recording medium measured by the reflectance measuring unit was 70%. In order to make the amount of energy of the active line transmitted through the intermediate transfer body and the amount of energy of the active line reflected on the surface to which the ink of the recording medium is transferred match with the formation of the solid image 1, the first activity is performed. The amount of energy of the active ray to be irradiated from the ray irradiation unit is 0.8333 W / cm ² . At the time of forming the solid image 2, the energy amount of the active line irradiated from the first active line irradiation portion was 1.000 W / cm ² , and the energy amount of the active line was an excessive condition.

(Formation of solid image 3)
A solid image 3 was formed in the same manner as the solid image 1 except that the intermediate transfer material deteriorated by use was used, high-quality paper C was used as a recording medium, and the image hiding rate was set to 80%. The transmittance of ultraviolet rays having a wavelength of 395 nm of this deteriorated intermediate transfer material was 90.0%. The reflectance of ultraviolet rays having a wavelength of 395 nm of this recording medium measured by the reflectance measuring unit was 50%. In order to make the amount of energy of the active line transmitted through the intermediate transfer body and the amount of energy of the active line reflected on the surface to which the ink of the recording medium is transferred match with the formation of the solid image 1, the first activity is performed. The amount of energy of the active ray to be irradiated from the ray irradiation unit is 1.3066 W / cm ² . At the time of forming the solid image 3, the amount of energy of the active line irradiated from the first active line irradiation portion was 1.000 W / cm ² , which was a condition that the amount of energy of the active line was small.

(Evaluation of ink crushing)
The solid image 1 to the solid image 3 were magnified and observed, and the average value of the diameters of one dot was measured. When the dot diameter was 60 μm or less, it was determined that the ink crushing was within the permissible range.

(Evaluation of fixability)
The area ratio of the dots occupying the solid image 1 to the solid image 3 was measured. Then, the non-woven fabric was brought into contact with the surface of each solid image, and the recording medium on which the solid image was formed was reciprocated 15 times to the left and right while applying a load of about 300 Pa by a weight (rubbing test). The speed of the reciprocating motion was about 0.2 m / sec. The area ratio of the dots occupying the solid images 1 to 3 after the rubbing test was measured, and the maintenance rate of the area ratio with respect to the area ratio of the solid images before the rubbing test was determined. When the maintenance rate of the area ratio was 90% or more, the fixability of the ink was considered to be within the permissible range.

Table 8 shows the evaluation results of ink crushing and fixability of the solid image 1 to the solid image 3.

As shown in Table 8, when the amount of energy of the active rays irradiated by the first active ray irradiation unit was appropriate, both the crushing and the fixability of the ink were within the permissible range. On the other hand, if the amount of energy of the active rays irradiated by the first active ray irradiation unit is excessive, the fixability of the ink is lowered. Further, when the amount of energy of the active ray irradiated by the first active ray irradiation unit is insufficient, the ink is crushed.

The present invention is suitable as an image forming apparatus for forming an image with an active ray-curable ink using an intermediate transfer body.

11, 12, 13, 14 Image forming device 20 External device 40 Control unit 41 CPU
42 RAM
43 ROM
44 Storage unit 51 Transport drive unit 52 Input / output interface 100 Paper feed unit 110 Paper feed tray 120 Media supply unit 132 Irradiation unit 134 Measuring unit 200 Image forming unit 210 Delivery unit 212 Swing arm unit 214 Delivery drum 220 Head unit 222 Head drive unit 224 Inkjet head 226 Ink layer 226a Surface 230 Intermediate transfer 230a Back 230b Surface 232, 234 Driven roller 236 Transfer roller 240 Transfer drum 250 Delivery unit 251 Delivery drum 252 Belt loop 262 1st active ray irradiation unit 264 2nd active ray irradiation unit 270 Cleaning unit 300 Paper ejection unit 310 Paper ejection tray 510 Temperature adjustment unit 610 Transmission amount measurement unit 620 Reflection amount measurement unit 710 Intermediate image imaging unit

Claims (14)

With the intermediate transcript,
An ink-applying portion that applies an active ray-curable ink to the surface of the intermediate transfer body,
A transfer unit that transfers the applied ink to a recording medium, and
The transfer unit has an active line irradiation unit that irradiates the active line that has passed through the intermediate transfer body from a back surface side different from the front surface to which the ink is applied.
The active ray irradiation unit changes the amount of energy of the active ray to be irradiated according to the characteristics of the recording medium.
Image forming device. The active ray irradiation unit changes the amount of energy of the active ray to be irradiated according to the reflectance of the active ray on the surface on which the ink of the recording medium is transferred.
The image forming apparatus according to claim 1. The active ray irradiation unit reduces the amount of energy of the activated ray to be irradiated with respect to the recording medium having a higher reflectance.
The image forming apparatus according to claim 2. The active ray irradiation unit uses the sum of the energy amount of the active ray transmitted through the intermediate transfer body and the energy amount of the active ray reflected on the surface of the recording medium to which the ink is transferred as a recording medium. The amount of energy of the activated line to be irradiated is changed so as to keep it constant.
The image forming apparatus according to any one of claims 1 to 3. It has a reflectance measuring unit for measuring the reflectance of the active line on the surface of the recording medium to which the ink is transferred.
The active ray irradiating unit changes the amount of energy of the irradiating active ray according to the reflectance measured by the reflectance measuring unit.
The image forming apparatus according to any one of claims 2 to 4. It has an input reception unit that accepts the selection or setting of recording media.
The active ray irradiating unit changes the amount of energy of the irradiating active ray according to the selection or setting of the recording medium received by the input receiving unit.
The image forming apparatus according to any one of claims 1 to 4. It has a temperature adjusting unit for adjusting the temperature of the surface on which the ink of the recording medium is transferred.
The temperature adjusting unit changes the temperature of the surface of the recording medium according to the characteristics of the recording medium.
The image forming apparatus according to any one of claims 1 to 6. It has an input reception unit that accepts the selection or setting of recording media.
The temperature adjusting unit changes the temperature of the surface of the recording medium according to the selection or setting of the recording medium received by the input receiving unit.
The image forming apparatus according to claim 7. The active ray irradiation unit changes the amount of energy of the active ray to be irradiated according to the transmittance of the active ray of the intermediate transfer body that transmits the active ray.
The image forming apparatus according to any one of claims 1 to 8. It has a storage unit for storing the mileage data of the intermediate transfer body, and has a storage unit.
The active ray irradiation unit changes the amount of energy of the active ray to be irradiated according to the mileage data of the intermediate transfer body stored in the storage unit.
The image forming apparatus according to claim 9. It has a transmittance measuring unit for measuring the transmittance of the active line of the intermediate transcript.
The active ray irradiation unit changes the amount of energy of the active ray to be irradiated according to the transmittance of the active ray measured by the transmittance measuring unit.
The image forming apparatus according to claim 9. It has a concealment rate measuring unit for determining the concealment rate of the intermediate image formed on the surface of the intermediate transfer body by applying the ink with the ink.
The active ray irradiation unit changes the amount of energy of the active ray to be irradiated according to the concealment rate measured by the concealment rate measuring unit.
The image forming apparatus according to any one of claims 1 to 11. It has an input reception unit that accepts image data indicating the image to be formed.
The active ray irradiating unit determines the amount of energy of the activated ray to be irradiated according to the hiding rate of the intermediate image formed on the surface of the intermediate transfer body by the application of the ink, which is calculated from the image data. change,
The image forming apparatus according to any one of claims 1 to 11. The ink applying portion applies the ink by an inkjet method.
The image forming apparatus according to any one of claims 1 to 13.

Images