JP2020055112A - Image forming apparatus and image forming system - Google Patents

Abstract

To provide an image forming apparatus and an image forming system which are capable of varying application of processing liquid according to a recording medium without lowering productivity in image forming processing.SOLUTION: An image forming system 1000 comprises: an image forming part 310 for forming an image by discharging droplets while conveying a recording medium; a processing liquid application part 210 for applying a processing liquid onto the recording medium while conveying the recording medium before the image is formed thereon; and a control part which controls an image forming conveyance speed, which is the speed at which the recording medium is conveyed in the image forming part 310, and a liquid application conveyance speed, which is the speed at which the recording medium is conveyed in the processing liquid application part 210. The control part performs control in such a manner that the liquid application speed is not less than the image forming conveyance speed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an image forming apparatus and an image forming system.

  In an image forming apparatus that forms an image by discharging droplets onto a recording medium, a treatment liquid having an effect of making the state of droplets attached to the recording medium a preferable state for image formation is applied to the recording medium before image formation. What has the processing liquid application function to perform is known. There is also known an image forming system configured by combining a processing liquid application device specialized in a function of applying a processing liquid and an image forming device having an image forming function.

  The optimal amount of the treatment liquid used in the above-described image forming apparatus and image forming system varies depending on the type of recording medium. Therefore, in order to enhance the quality of image formation, it is desirable to adjust the amount of the processing liquid based on the recording medium. The treatment liquid is applied to a recording medium via an application roller. Therefore, the application amount of the processing liquid is correlated with the rotation speed of the application roller on the recording medium.

  In order to vary the amount of treatment liquid applied by the application roller, a technology that varies the pressing force of the roller that presses the recording medium against the application roller, and multiple coating devices are arranged in series to perform multiple application of the processing liquid (For example, see Patent Document 1).

  Further, since the application roller also has a role of transporting the processing liquid while applying it, the application amount of the processing liquid to the recording medium is also related to the transport speed of the application roller. As a technique for adjusting the application amount of the processing liquid by adjusting the transport speed by the application roller, a technique of controlling the application speed to vary the application amount of the processing liquid is also disclosed (for example, see Japanese Patent Application Laid-Open No. H10-163873). reference).

  Further, a technique has been disclosed in which the application speed of a treatment liquid is made variable by changing the rotation speed of an application roller (for example, see Patent Document 3).

  SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus capable of changing the application of a processing liquid without reducing productivity in image forming processing.

  In order to achieve the above object, the present invention relates to an image forming apparatus, and includes an image forming unit that forms an image by discharging droplets while conveying a recording medium, and an image forming unit that forms the image. A processing liquid application unit that applies a processing liquid to the recording medium while conveying the recording medium, an image forming conveyance speed that is a speed at which the recording medium is conveyed in the image forming unit, and the processing liquid application unit A control unit that controls a liquid application conveyance speed, which is a speed at which the recording medium is conveyed, and the control unit controls the liquid application speed to be equal to or higher than the image forming conveyance speed. Features.

  According to the present invention, the application of the processing liquid can be changed according to the recording medium without lowering the productivity in the image forming processing.

FIG. 1 is a system configuration diagram of a printing system which is an embodiment of an image forming system according to the present invention. FIG. 1 is a configuration diagram illustrating an embodiment of an internal structure of a processing liquid application device that forms an image forming system according to the present invention. FIG. 2 is a diagram illustrating a conveyance path of a recording medium in the processing liquid application device according to the embodiment. FIG. 1 is a configuration diagram illustrating an embodiment of an internal structure of an image forming apparatus included in an image forming system according to the present invention. FIG. 3 is a diagram illustrating an example of a structure of a processing liquid application unit included in the processing liquid application apparatus according to the embodiment. 4 is a graph illustrating a relationship between an operation in a processing liquid application unit and a processing liquid application amount according to the embodiment. FIG. 4 is a diagram illustrating an example of a data table that defines an operation in a processing liquid application unit according to the embodiment. FIG. 5 is a diagram illustrating an example of a data table for correcting an operation in the processing liquid application unit according to the embodiment.

[Summary of the present invention]
The present invention provides a processing liquid application unit that applies a processing liquid acting on an image forming material (ink) to an image forming surface of a recording medium, an image forming unit that forms an image on the image forming surface coated with the processing liquid, The present invention relates to an image forming apparatus including: The present invention also relates to an image forming system configured to link an image forming apparatus for forming an image on an image forming surface and a processing liquid applying apparatus for applying a processing liquid to the image forming surface.

  The processing liquid used in the image forming apparatus and the image forming system according to the present invention changes the state of the image forming surface of the recording medium on which an image is formed with the image forming material (liquid ink or the like) into a state suitable for image formation. It is a liquid that has the effect of making it so. Here, the “preferred state” refers to, for example, a state in which the image forming material (ink droplet) attached to the image forming surface is aggregated to prevent ink bleeding, or a state in which show-through is prevented.

  Therefore, the application amount of the processing liquid has an important effect on the image quality. Therefore, it is desirable that the amount of the treatment liquid applied to the recording medium be an optimum amount. Since the optimum amount of coating varies depending on the type of recording medium (including the type and brand, the same applies hereinafter), the amount of coating can be changed according to the type of recording medium, and the image forming speed is not affected. It is desirable.

  In this regard, in order to vary the application amount by changing the pressing load as in the technique disclosed in Patent Document 1 described above, the variable range is narrowed, and only fine adjustment is possible. There were challenges. When a plurality of coating apparatuses are arranged in series to perform multiple coatings in order to widen the variable range of the coating amount, there has been a problem that the coating apparatus becomes large and the apparatus cost becomes high.

  Further, according to the technique disclosed in Patent Literature 2, an application roller used to apply a processing liquid to a recording medium and a transport roller used to transport the recording medium are linked. Therefore, if the rotation speed of the coating roller is reduced to increase the application amount of the processing liquid and the transport speed of the coating roller is reduced, the rotation speed of the transport roller is also reduced and the transport speed is reduced. When the transport speed by the transport rollers decreases, the speed of image formation decreases. That is, when the amount of the processing liquid applied is adjusted using the technique of Patent Document 1, there is a problem that the image forming speed (printing speed) is sacrificed and the productivity in the image forming process is reduced.

  In addition, as in the technique disclosed in Patent Document 2, by providing an adhesion amount regulating member to the application roller, when the application amount is changed according to the pressure contact state of the regulation member, the contact between the regulation member and the application roller is reduced. Therefore, high-precision parts are required to make the uniformity. In addition, there is a problem that the range in which the coating amount can be varied is narrow, and only fine adjustment is possible.

  Further, since the technique disclosed in Patent Document 3 relates to coating on a roll-shaped medium (recording medium) connected from paper feeding to paper discharging, the printing speed by the head and the paper in the coating unit are determined. The speed is the same speed. In this configuration, changing the rotation speed changes the rotation speed of the application roller. Therefore, the technique disclosed in Patent Literature 3 is a technique for varying the amount of application by slipping between the application roller and the sheet. According to this technique, the recording medium and the applying roller are positively slipped. Therefore, there is a problem that the contact between the edge of the recording medium and the coating roller accelerates the wear of the coating roller and shortens the life.

  Note that the technology disclosed in Patent Document 3 can use a roll-shaped medium that is continuously applied with tension from paper feeding to paper discharging as a recording medium. There is also a problem that the application roller of a different speed comes into contact with the recording medium when the tension is released, causing a jam, which may cause a conveyance failure because the tension cannot be continuously applied by transferring the paper with the roller. there were.

  An image forming apparatus and an image forming system according to the present invention can solve the problems related to the related art as described above. The conveyance speed of the storage medium by the application roller that applies the processing liquid to the recording medium, the conveyance speed by the conveyance roller that conveys the recording medium during the image forming process, is controlled to maintain a constant relationship, This is one of the points. Here, "making the transfer speed by the application roller a constant relationship with the transfer speed by the transfer roller" means "control the transfer speed by the coating roller to be equal to or higher than the transfer speed by the transfer roller." That means.

  Therefore, the image forming apparatus and the image forming system according to the present invention can set the adjustment range of the application amount of the processing liquid broadly, and can finely adjust the adjustment width. To be able to suppress enlargement. Further, the image forming apparatus and the image forming system according to the present invention provide an optimum amount according to the type of the recording medium even if the transport speed (printing speed) in the image forming process is constant regardless of the type of the recording medium. It is possible to apply the processing liquid and not to affect the printing speed. Therefore, as the recording medium, “cut paper” cut into a predetermined size can be used, and the variable range of the application amount of the processing liquid can be expanded, so that a wide variety of recording media (media) can be used. Thus, an optimal amount of the processing liquid can be applied, and the productivity of image formation can be maintained.

  Further, according to the image forming apparatus and the image forming system of the present invention, it is possible to prevent wasteful consumption of the processing liquid due to an excessive amount of application. Also, it is possible to prevent "jam" caused by the processing liquid adhering to the transport roller due to excessive application of the processing liquid. Further, it is possible to prevent the image quality from being lowered due to the insufficient amount of coating. Furthermore, the image forming apparatus and the image forming system according to the present invention can adopt a configuration that can fit in a small space, can reduce the manufacturing cost, and can reduce the quality of the application roller due to abrasion, as compared with the related art. It can also be prevented.

[Embodiment of Image Forming System]
First, an embodiment of an image forming system according to the present invention will be described. FIG. 1 is a schematic configuration diagram illustrating an outline of a printing system 1000 which is an embodiment of an image forming system. As shown in FIG. 1, the printing system 1000 includes a feeding device 100, a processing liquid application device 200, a printer 300 as an image forming device, and a medium discharging device 400. Note that an image forming apparatus configured by combining the processing liquid coating apparatus 200 and the printer 300 is an embodiment of the image forming apparatus according to the present invention.

  The feeding device 100 is a recording medium supply device that supplies a sheet-shaped recording medium having an image forming surface on which an image is formed in an image forming process to a treatment liquid coating device 200 provided on a downstream side of a sheet conveyance path. is there. The recording medium supplied from the feeding device 100 is, for example, “cut paper” cut to a predetermined size. Hereinafter, the description of the present embodiment is based on the premise that the recording medium is cut paper, and is described as “sheet 8”.

  The treatment liquid application device 200 includes a treatment liquid application unit 210 that applies a treatment liquid having an operation effect of coagulating ink and preventing show-through onto the image forming surface of the sheet 8.

  The printer 300 includes an image forming unit 310 that forms an image by ejecting ink droplets onto the sheet 8 to which the processing liquid is applied by the processing liquid application device 200, and a drying unit that dries the processing liquid and the ink droplets attached to the sheet 8. A unit 320. Note that the printer 300 also includes a transport path for turning the sheet 8 from the drying unit 320 back to the image forming unit 310 when printing on the front and back of the sheet 8. In this way, an image is formed by ejecting ink droplets on the back side of the image forming surface on which the image has been formed first, and then the surface on which the new image has been formed is dried in the drying unit 320. It can be discharged to the discharge device 400.

  The medium discharge device 400 is a device that stores the sheet 8 on which the image forming process has been performed in the printer 300.

[Configuration of treatment liquid coating device 200]
Next, the treatment liquid application device 200 according to the present embodiment will be described with reference to the drawings. FIG. 2 is a configuration diagram illustrating a configuration of the processing liquid application device 200. As shown in FIG. 2, the treatment liquid application device 200 includes a treatment liquid application unit 210, a control unit 220, a treatment liquid supply unit 230, a carry-in unit 240, and a carry-out unit 250.

  Further, the processing liquid application device 200 has a transport path 260 including a plurality of transport rollers and a plurality of paper guides. Further, the transport path 260 of the unloading section 250 has a first branch gate for switching the transport direction of the sheet 8. 251 and a second branch gate 252 are arranged.

  Further, the processing liquid application device 200 has a control unit 220 that controls the entire operation. The control unit 220 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and an NVRAM (Non-volatile Memory) that is a rewritable nonvolatile memory for holding data even when power is shut off. The information processing unit includes a non-volatility random access memory (Non-Voltage Random Access Memory), and realizes a processing function by executing a computer program.

  The control unit 220 controls the operation of the operation mechanism included in the processing liquid application device 200 by causing the CPU to execute a control program recorded in the ROM. The RAM provided in the control unit 220 is used as a work area when the control program is executed. The NVRAM of the control unit 220 stores various data used in a processing liquid application control process described later. That is, the control unit 220 causes the CPU to read the control program stored in the ROM and expand the control program in the storage area of the RAM, and execute the control program while the CPU reads various data stored in the NVRAM. The NVRAM constitutes a storage unit that stores a coating amount data table and a coating amount correction data table described later.

  The control unit 220 controls the conveyance speed of the sheet 8 (liquid application conveyance speed) by the operation of the application roller included in the processing liquid application unit 210 based on the conveyance speed of the sheet 8 in the printer 300 (image formation conveyance speed). I do. In this case, the control unit 220 controls the liquid application conveyance speed to be higher than the image formation conveyance speed. Specifically, the rotation speed of the drive source for rotating the coating roller is controlled so as to be higher than the rotation speed of the drive source that regulates the image forming / conveying speed, and the control changes the rotation speed of the coating roller. Then, the application amount of the processing liquid is changed. Therefore, the control unit 220 controls the liquid application conveyance speed to be arbitrarily changeable while keeping the image formation conveyance speed constant. That is, by using the image forming and conveying speed as a reference and controlling the amount of change in the liquid applying and conveying speed relative to this reference, the liquid applying and conveying speed is arbitrarily changed to change the amount of the processing liquid applied.

  The control unit 220 also controls the operation of conveying the sheet 8 in the conveyance path 260 and the operation of switching between the first branch gate 251 and the second branch gate 252.

  The sheet 8 as a single-sheet medium discharged from the feeding device 100 is carried into the treatment liquid application device 200 via the carry-in part 240, is conveyed by the conveyance path 260, reaches the treatment liquid application part 210, and Is applied. Thereafter, the sheet is conveyed to the unloading section 250 by the transfer path 260 and is unloaded to the printer 300. Note that the bold arrows in FIG. 2 illustrate the transport direction of the sheet 8 in the transport path 260.

[Conveying Mode in Treatment Liquid Coating Apparatus 200]
FIG. 3 is a diagram exemplifying a state of conveyance of the sheet 8 when the processing liquid is applied to both surfaces of the sheet 8 in the processing liquid application device 200. In the case where image forming processing is performed on both sides of the sheet 8, that is, in the case of double-sided printing, it is necessary to apply the processing liquid to both sides of the sheet 8 in the processing liquid application device 200. Thus, the control unit 220 controls the sheet 8 to be conveyed as shown in FIG. In FIG. 3, the conveying order of the sheet 8 is indicated by bold arrows (A to J).

  First, when the sheet 8 is carried in from the feeding device 100 to the treatment liquid application device 200 through the carrying-in section 240, the sheet 8 is conveyed in the order of the conveyance paths A, B, and C. As a result, the sheet 8 is conveyed to the treatment liquid application unit 210. In the processing liquid application unit 210, first, the processing liquid is applied to one surface (front surface) of the sheet 8. Thereafter, the sheet 8 passes through the conveyance paths D to E. Here, when the control unit 330 switches the first branch gate 251, the sheet 8 is transported to the transport path F. Then, the sheet 8 reaches the transport path G through the second branch gate 252.

  Here, the control unit 220 switches the second branch gate 252 to reverse the conveying direction of the sheet 8. Thereafter, the sheet 8 travels in the opposite direction as before, as in the transport path H, passes through the switched second branch gate 252, passes through the transport path I through the transport path C, and again applies the processing liquid. Conveyed to the unit 210. At this time, the processing liquid is applied to the back surface of the sheet 8. The sheet 8 to which the processing liquid has been applied on both sides thereafter passes through the transport path E from the transport path D. Then, when the control unit 220 switches the first branch gate 251 again, the sheet 8 passes through the transport path J and is discharged from the discharge unit 250. By the above operation, the sheet 8 on which the processing liquid is applied to both sides is delivered to the printer 300.

[Configuration of Printer 300]
Next, the printer 300 according to the present embodiment will be described with reference to the drawings. FIG. 4 is a configuration diagram illustrating a configuration of the printer 300. As shown in FIG. 4, the printer 300 includes an image forming unit 310 and a drying unit 320. The printer 300 has a transport path 340 including a plurality of transport rollers and a plurality of paper guides. The transport path 340 further includes a third branch gate 341 for switching the transport direction of the sheet 8 and a fourth branch gate 341. 342.

  Further, the printer 300 has a control unit 330 for controlling the entire operation. The control unit 330 has the same configuration as the control unit 220 described above, and includes a CPU, a ROM, a RAM, an NVRAM, and the like. The control unit 330 is an information processing unit that realizes a processing function for controlling the printer 300 by causing the CPU to execute a control program recorded in the ROM.

  The control unit 330 controls the rotation speed of the conveyance roller 313 by controlling the rotation speed of the conveyance motor 313 included in the image forming unit 310. The transport roller 312 and the transport motor 313 are a transport mechanism that transports the sheet 8 to the image forming unit 310. Therefore, the control of the rotation speed of the conveyance motor 313 by the control unit 330 controls the conveyance speed of the sheet 8 to the image forming unit 310. The conveyance speed of the sheet 8 in the image forming unit 310 is referred to as “image formation conveyance speed”.

  In addition, the control unit 330 also performs the operation of transporting the sheet 8 in the transport path 340 and the operation of switching between the third branch gate 341 and the fourth branch gate 342.

  The control unit 330 operates in cooperation with the control unit 220 of the processing liquid application device 200. That is, the control unit 330 notifies the control unit 220 of data defining the image forming and conveying speed of the sheet 8, such as the rotation speed of the conveying roller 312. The control unit 220 of the treatment liquid application device 200 adjusts the rotation speed of the drive source that rotates the application roller included in the treatment liquid application unit 210 based on the image formation conveyance speed notified from the control unit 330, as described above. Control. The transport speed of the sheet 8 in the processing liquid application unit 210 controlled by the control unit 220 is referred to as “liquid application transport speed”.

  In the case of an image forming apparatus in which the processing liquid application device 200 and the printer 300 are integrated, it is sufficient to provide a control unit integrated with the functions realized by the control unit 220 and the control unit 330.

[Conveying Mode in Printer 300]
The sheet 8 as a single-sheet medium discharged from the processing liquid application device 200 is transported by the transport path 340 to reach the image forming unit 310, and the ink liquid is discharged as droplets from the recording head 311 as the liquid discharge head. An image is formed. Thereafter, the sheet 8 passes through the drying unit 320 by the transport path 340, and passes through the drying unit 320 while drying the image forming surface to which the droplets and the processing liquid that have landed in the image forming process adhere. Note that the thick arrow in FIG. 4 illustrates the transport direction of the sheet 8 in the transport path 340.

  When the image forming process is performed on only one side of the sheet 8 discharged from the processing liquid application device 200, the sheet 8 passes through the conveying route L from the conveying route K, and passes through the third branch gate 341 from the conveying route M after the image forming process. The paper passes through the transport path O and is discharged to the medium discharge device 400.

  When the sheet 8 having the processing liquid applied to both sides of the sheet 8 is conveyed and the image forming process is performed on both sides, when the sheet 8 is carried in from the processing liquid application device 200, the conveyance paths K, L, M After the sheet 8 is conveyed in this order, the control unit 330 switches the third branch gate 341. As a result, the sheet 8 is transported to the transport path P instead of the transport path 0, and then passes through the fourth branch gate 342 to reach the transport path Q.

  Here, the control unit 330 switches the fourth branch gate 342 to reverse the conveying direction of the sheet 8. As a result, the sheet 8 travels in the opposite direction as before, as in the transport path R, passes through the switched fourth branch gate 342, and is transported again from the transport path S via the transport path T. The sheet is conveyed to the image forming unit 310 through the paths K and L. Thus, the image forming process is performed on the back surface of the sheet 8.

  Then, the sheet 8 having the image formed on both sides is dried on the image forming surface while passing through the transport path M, and the control unit 330 switches the third branch gate 341 again, so that the transport path M It passes through O and is discharged. By the above operation, the sheet 8 on which the predetermined image is formed is discharged to the medium discharge device 400.

[Configuration of Processing Liquid Application Unit 210]
Next, the configuration of the processing liquid application unit 210 will be described. FIG. 5 is a diagram illustrating a detailed configuration of the processing liquid application unit 210 and the processing liquid supply unit 230. As shown in FIG. 5, the processing liquid application unit 210 includes a plurality of roller members. The processing liquid application section 210 includes a transfer roller 2201, an application roller 2204, and a pumping roller 2208 as a plurality of roller members.

  The transfer roller 2201 is rotatably supported by one end of a TR arm 2202 whose intermediate position is supported by a swing fulcrum 2205. The TR arm 2202 has one end and the other end swinging to the opposite side in the vertical direction with the swing fulcrum 2205 as a boundary. A TR spring 2203 is connected to the other end of the TR arm 2202. Therefore, the other end of the TR arm 2202 is pulled in the direction opposite to the direction of gravity, and as a result, the transfer roller 2201 is supported while being urged in the direction of gravity. As a result, the transfer roller 2201 is brought into a state of being elastically pressed against the application roller 2204 disposed on the gravity direction side.

  When the sheet 8 passes through the nip formed between the transfer roller 2201 and the application roller 2204, the processing liquid attached to the outer peripheral surface of the application roller 2204 is applied to the sheet 8.

  Further, a TR cam 2206 is disposed above the other end of the TR arm 2202 (the end to which the TR spring 2203 is connected), and the upper surface of the TR arm 2202 contacts the TR cam 2206. It is in a state. When the TR cam 2206 rotates, the position of the outer peripheral surface of the TR cam 2206 is displaced, and the TR cam 2206 operates so as to push down the contact surface of the TR cam 2206 in the direction of gravity. Then, a pressing force in the direction of gravity is applied to the other end of the TR arm 2202 against the pulling force of the TR spring 2203. By the force applied to the other end of the TR arm 2202 by the rotation of the TR cam 2206, the transfer roller 2201 supported on one end of the TR arm 2202 is moved in the direction opposite to the direction of gravity. Thus, an operation of separating the transfer roller 2201 from the application roller 2204 can be performed. The rotation of the TR cam 2206 is performed by a cam motor 2207. That is, the nip of the transfer roller 2201 with the application roller 2204 is controlled based on the rotation of the cam motor 2207.

  The transfer roller 2201 is rotated by contact with the application roller 2204 by elastic pressure contact. Note that the transfer roller 2201 and the application roller 2204 can be connected by a gear.

  The application roller 2204 is rotatably supported by a casing side plate of the processing liquid application unit 210, and rotates using a driving force of a first motor 2225 as a first driving unit as a driving source. In other words, the first motor 2225 drives the application roller 2204 to rotate. That is, the rotation speed of the application roller 2204 is determined according to the rotation speed of the first motor 2225. The support position of the application roller 2204 is vertically movable when the transfer roller 2201 side is set to the upper direction and the pumping roller 2208 side is set to the lower direction. The application roller 2204 is configured to elastically contact the pumping roller 2208 by elastic contact from the transfer roller 2201.

  The pumping roller 2208 is rotatably supported by a side plate of the supply liquid chamber 2209, and rotates using a driving force of a second motor 2226 as a second driving unit as a driving source. In other words, the second motor 2226 drives the pumping roller 2208 to rotate. That is, the rotation speed of the pumping roller 2208 is determined according to the rotation speed of the second motor 2226.

  The supply liquid chamber 2209 serving as a liquid supply pan is swingably fixed to the casing of the processing liquid application unit 210 by a liquid chamber swing fulcrum 2213 provided on one surface of the outer surface. In addition, an arm 2210 is provided on the outer surface of the supply liquid chamber 2209 and opposite to the above-mentioned protrusion. The arm 2210 urges the supply liquid chamber 2209 upward (toward the transfer roller 2201) by a compression spring 2212 via a pin 2211. Therefore, the supply liquid chamber 2209 is urged upward by the compression spring 2212. By the urging of the compression spring 2212, the pumping roller 2208 fixed to the supply liquid chamber 2209 can be elastically pressed against the application roller 2204.

  A cam 2214 is in contact with the pin 2211, and is configured to vary the pressing force of the compression spring 2212 by rotation of the cam 2214. Therefore, the nip load between the application roller 2204 and the pumping-up roller 2208 can be changed by the rotation of the cam 2214. In addition, the rotation of the cam 2214 changes the pressing force of the compression spring 2212, and changes the position of the supply liquid chamber 2209. The rotation of the cam 2214 is performed by using the third motor 2215 as a drive source. Therefore, the control unit 220 (see FIG. 2) controls the driving of the third motor 2215, so that the contact and the separation between the application roller 2204 and the pumping roller 2208 can be controlled.

  In the supply liquid chamber 2209, a processing liquid 2216, which is a processing liquid, is stored. The pumping roller 2208 is partially immersed in the processing solution 2216. Since the pumping roller 2208 is in pressure contact with the application roller 2204 by elastic force, when the pumping roller 2208 rotates and rotates while adhering the processing agent liquid 2216 in the supply liquid chamber 2209 to the outer peripheral surface, the pumping roller 2208 passes through the nip. The treatment liquid 2216 is delivered from the pumping roller 2208 to the application roller 2204. The application roller 2204 moves the sheet 8 on the transport path 260 while applying the processing agent liquid 2216 received from the pumping roller 2208 to the sheet 8 at the nip with the transfer roller 2201.

  The supply liquid chamber 2209 is provided with a liquid level sensor 2218 for detecting the liquid level of the processing agent liquid 2216. The liquid level sensor 2218 is attached at a position corresponding to the liquid level at which the processing agent liquid 2216 becomes an appropriate amount. By monitoring the output of the liquid level sensor 2218, it is possible to monitor whether or not the processing agent liquid 2216 is in an appropriate amount. Note that the appropriate amount of the processing solution 2216 means a state in which the liquid level of the processing solution 2216 is about the rotation center of the pumping roller 2208.

  Further, inside the supply liquid chamber 2209, a temperature sensor 2227 for detecting the temperature of the treatment liquid 2216 is provided. The temperature sensor 2227 may be installed at a position soaked in the processing agent liquid 2216, or may be installed at a position where the temperature of the processing agent liquid 2216 can be calculated by measuring the environmental temperature of the supply liquid chamber 2209. . The temperature measured by temperature sensor 2227 is notified to control unit 220.

[Replenishment operation of treatment agent liquid 2216]
When the treatment liquid 2216 is applied to the sheet 8, the treatment liquid 2216 stored in the supply liquid chamber 2209 is consumed, and the liquid level is lowered. When the liquid level sensor 2218 stops detecting the liquid level of the processing agent liquid 2216, the supply valve 2219 is opened and the supply pump 2220 is driven. By driving the supply pump 2220, the processing agent liquid 2216 held in the supply tank 2221 is sent into the supply liquid chamber 2209.

  When the liquid level reaches a predetermined level, the supply valve 2219 is closed and the supply pump 2220 is stopped. By the above operation, the processing liquid application section 210 is configured so that the level of the processing liquid 2216 stored in the supply liquid chamber 2209 is kept constant.

  Further, the properties of the treatment agent liquid 2216 may change with time. For example, it is necessary to consider that the treatment liquid 2216 stored in the supply liquid chamber 2209 increases in viscosity after a certain period of time. Therefore, a drain valve 2222, a drain pump 2223, and a drain tank 2224 are provided as a mechanism for discharging the processing agent liquid 2216 after a certain period of time. By opening the drain valve 2222 and driving the drain pump 2223, the deteriorated treatment agent liquid 2216 in the supply liquid chamber 2209 can be discharged to the drain tank 2224.

[Application process of treatment agent liquid 2216]
Next, a coating process according to the present embodiment will be described. In the configuration of the processing liquid application section 210 described above, when the second motor 2226 rotates the pumping roller 2208, the processing liquid 2216 stored in the supply liquid chamber 2209 is pumped by the pumping roller 2208. The pumped processing agent liquid 2216 is carried to a contact position (nip) with the application roller 2204.

  The treatment agent liquid 2216 moves to the application roller 2204 with a predetermined liquid amount by passing through the contact position between the pumping roller 2208 and the application roller 2204. At this time, the moved processing agent liquid 2216 adheres to the outer peripheral surface of the application roller 2204 and becomes thin. As a result, the amount of the treatment liquid 2216 becomes a predetermined amount. Therefore, at the nip between the pumping roller 2208 and the application roller 2204, the amount of the processing agent liquid 2216 to be applied to the sheet 8 is measured.

  The measured thinning agent liquid 2216 that has become thinner is carried to the contact position (nip) with the transfer roller 2201 by the rotation of the application roller 2204. When the sheet 8 passes through the contact position between the application roller 2204 and the transfer roller 2201, the trace liquid layer on the surface of the application roller 2204 is transferred to the sheet 8. The application process is performed as described above, and the processing agent liquid 2216 stored in the supply liquid chamber 2209 is applied to the sheet 8.

  In the above configuration, the thickness (passing film thickness) of the liquid film of the processing agent liquid 2216 passing between the elastically pressed rollers depends on the speed of each roller. In general, the higher the rotation speed of the pumping roller 2208, the greater the amount of the treatment liquid 2216 carried to the application roller 2204. That is, the thickness of the liquid film formed on the surface of the application roller 2204 increases.

  Therefore, when it is desired to increase the amount of the processing agent liquid 2216 applied to the sheet 8, the rotation speed of the pumping roller 2208 by the second motor 2226 is increased to increase the amount of the processing agent liquid 2216 supplied to the coating roller 2204. When the application roller 2204 applies the treatment liquid 2216 to the sheet 8, the rotation speed of the application roller 2204 may be reduced.

[Relationship Between Application Amount of Treatment Agent Liquid 2216 and Rotation Speed of Application Roller 2204]
Next, the relationship between the amount of the treatment liquid 2216 applied to the sheet 8 and the rotation speed of the application roller 2204 in the treatment liquid application unit 210 according to the present embodiment will be described with reference to the graph of FIG. In the graph shown in FIG. 6, the vertical axis indicates the amount of the processing agent liquid 2216 applied to the sheet 8, and the horizontal axis indicates the “rotation speed ratio (peripheral speed ratio)” between the application roller 2204 and the pumping roller 2208.

  FIG. 6 shows three graphs. The graph G1, the graph G2, and the graph G3 each distinguish the case where the rotation speed of the pumping roller 2208 is constant and the rotation speed of the application roller 2204 is different. The graph G1 represents a case where the rotation speed of the application roller 2204 is “speed S1”. The graph G2 represents a case where the rotation speed of the application roller 2204 is “speed S2”. The graph G3 represents a case where the rotation speed of the application roller 2204 is “speed S3”.

  Each speed has a relationship of “speed S1 <speed S2 <speed S3”. When the rotation speed of the application roller 2204 is the speed S1, the conveyance speed of the conveyance roller 312 is the same as the conveyance speed of the application roller 2204. That is, the graph of the speed S1 shows the relationship between the peripheral speed ratio and the application amount when the liquid application transport speed and the image forming transport speed are the same.

  When the rotation speed of the first motor 2225 is set to the speed S2, the rotation speed of the application roller 2204 becomes faster than the rotation speed of the transport roller 312. That is, the graph of the speed S2 shows the relationship between the peripheral speed ratio and the application amount when the liquid application transport speed is higher than the image forming transport speed.

  When the rotation speed of the first motor 2225 is set to the speed S3, the rotation speed of the application roller 2204 is higher than the rotation speed of the transport roller 312. That is, the graph of the speed S3 shows the relationship between the peripheral speed ratio and the application amount when the liquid application transport speed is higher than the image forming transport speed.

  As shown in the graph of FIG. 6, by varying the rotation speed of the application roller 2204 between the speed S1 and the speed S3, for example, in the case where the peripheral speed ratio is “peripheral speed ratio: C”, the processing agent liquid 2216 The application amount can be changed between “range A”.

  The control unit 220 varies the rotation speed of the application roller 2204 based on the rotation speed of the conveyance roller 312, and controls the rotation speed of the application roller 2204 so that “image formation conveyance speed ≦ liquid application conveyance speed”. . Therefore, the control unit 220 has a function of receiving a notification of the rotation speed of the transport motor 313 from the control unit 330, and controls the rotation speed of the first motor 2225 in response to the notification. As a result, the conveying speed of the sheet 8 to which the processing agent liquid 2216 is applied by the applying roller 2204 is set to be equal to or higher than the conveying speed at which the image forming process is performed, and an optimal amount of application to the sheet 8 is realized. The transport speed of the sheet 8 to which the processing liquid 2216 has been applied in the processing liquid application section 210 is reduced before reaching the image forming section 310. Therefore, the application amount of the processing liquid 2216 to the sheet 8 can be changed while the image forming process speed (printing speed) is kept constant, and the sheet forming process is not affected and the sheet forming process is not affected. 8 can be applied with an appropriate amount of the processing agent liquid 2216.

  Further, in the processing liquid application unit 210 according to the present embodiment, when the rotation speed of the application roller 2204 is constant (when the liquid application conveyance speed is constant), the peripheral speed ratio is changed to obtain an example of the graph G1. In, the application amount of the treatment agent liquid 2216 can be changed between “range B”.

  Here, the position at which the peripheral speed ratio is determined is between the application roller 2204 and the pumping-up roller 2208. In other words, there is no contact with the edge of the sheet 8 as the recording medium, and there is a difference in the peripheral speed between the rollers where the processing liquid 2216 is present. There is no influence of wear or the like on the 2204 and the pumping roller 2208, and high durability can be secured.

  Furthermore, according to the processing liquid application unit 210 according to the present embodiment, by applying the application speed and the peripheral speed ratio, the application amount of the processing agent liquid 2216 can be reduced within the range of “range A” and “range B”. Can be variable. It is possible to increase the range in which the application amount of the treatment liquid 2216 is changed while maintaining the productivity of the image forming process. By expanding the variable range of the application amount of the processing agent liquid 2216, it is possible to realize the application processing of the processing agent liquid 2216 having the optimum application amount for various recording media of various types. Can be.

[Example of application amount data table]
The processing liquid application apparatus 200 according to the present embodiment is referred to when the control 220 controls the rotation speed of the application roller 2204 in order to apply the optimum processing agent liquid 2216 according to the type of the sheet 8 as a recording medium. The application amount data table to be used is stored in the storage unit of the control unit 220.

  FIG. 7 is a control table T1 which is an embodiment of the application amount data table. The control table T1 has a structure in which the rotation speed and the peripheral speed ratio of the first motor 2225 corresponding to the type of the sheet 8 are linked. The data stored in the control table T1 is data for defining the liquid application transport speed so that the application amount of the processing agent liquid 2216 according to the type of the sheet 8 becomes an optimum amount.

  The processing liquid application device 200 may be configured to include a sensor that detects the type of the sheet 8 in the loading unit 240, or receives an input of the type of the sheet 8 or the like via the operation panel included in the processing liquid application device 200 or the printer 300. A configuration may be used.

  When the control unit 220 executes the control program to execute the processing of applying the treatment liquid 2216 to the sheet 8, the control table T1 is read based on the detected type of the sheet 8 or the type of the sheet 8 input in advance. To select the rotation speed of the first motor 2225 and the peripheral speed ratio. For example, if the type of the sheet 8 is “P”, the rotation speed of the first motor 2225 is “P1” and the peripheral speed ratio is “P2”.

  The control unit 220 also determines the rotation speed of the pumping roller 2208 (the rotation speed of the second motor 2226) based on the read P1 and P2.

  Then, the control unit 220 controls the first motor 2225 to rotate at the rotation speed “P1”, and controls the second motor 2226 to rotate at the rotation speed calculated from the peripheral speed ratio “P2”. Accordingly, the processing agent liquid 2216 can be applied with an application amount corresponding to the processing agent liquid 2216 and the sheet 8 to be applied.

  The control data corresponding to the type of the sheet 8 which is not stored in the control table T1 in advance is arbitrarily input using an operation panel provided in the processing liquid application device 200 or an operation panel provided in the printer 300, and is input to the control unit 220. It can also be stored.

  In addition, each time the processing is performed, the application amount that is not based on the type of the sheet 8 can be designated via the operation panel. This makes it possible to reduce the application amount of the processing liquid 2216 and to suppress the consumption of the processing liquid 2216 without giving importance to the quality in the image forming processing.

  As described above, the processing liquid coating apparatus 200 according to the present embodiment stores the basic setting of the coating amount for each type of the sheet 8 as the control table T1, and arbitrarily sets the coating amount via the operation panel. Can also. This makes it possible to change the appropriate application amount of the treatment agent liquid 2216 in accordance with a wide range of types of the paper 9.

  The setting of the amount of application of the type of the sheet 8 is as shown in a graph G1 (see FIG. 6) in the case of the sheet 8 having the property that the processing agent liquid 2216 easily penetrates, for example, in the case of plain paper or recycled paper. The speed may be the same as the image forming and conveying speed. On the other hand, in the case of the sheet 8 having the property that the treatment agent liquid 2216 does not easily penetrate, for example, in the case of gloss coated paper, cast coated paper, film, or the like, an image is formed as shown in a graph G2 or G3 (see FIG. 6). What is necessary is just to make the liquid application conveyance speed higher than the formation conveyance speed. This is because the permeability of the treatment liquid 2216 into the sheet 8 affects the amount of application and the type of the agent that easily penetrates the sheet 8 has a larger amount of application. Therefore, for the sheet 8 of the type in which the application amount is large, the application amount is controlled by the liquid application conveyance speed, so that the variation in the application amount according to the type of the sheet 8 can be suppressed.

[Example of application amount correction data table]
As described above, the processing liquid application unit 210 according to this embodiment includes the temperature sensor 2227 that measures the temperature of the processing liquid 2216 in the supply liquid chamber 2209. The optimum amount of application to the sheet 8 is affected by the temperature of the treatment liquid 2216 in addition to the influence of the difference in the type of the sheet 8. This is because the viscosity of the processing agent liquid 2216 changes depending on the temperature. The higher the temperature is, the lower the viscosity of the treatment liquid 2216 is, so that the amount of application tends to decrease. Therefore, the temperature of the processing solution 2216 is appropriately measured by the temperature sensor 2227, and the value read from the control table T1 is corrected based on the measured result.

  The control unit 220 stores, in the storage unit, an application amount correction data table for correcting control data for applying the optimum processing agent liquid 2216 according to the processing agent liquid 2216. The application amount correction data table exemplified here stores correction coefficients as a temperature correction table.

  FIG. 8 is an example of a correction table T2 which is an embodiment of the temperature correction table. The correction table T2 has a structure in which a coefficient for correcting the rotation speed of the first motor 2225 and a coefficient for correcting the peripheral speed ratio are linked to the temperature range of the processing liquid 2216.

  The control unit 220 detects the type of the sheet 8 using a sensor included in the carry-in unit 240, or receives an input such as the type of the sheet 8 via the operation panel included in the processing liquid application device 200 or the printer 300, thereby controlling the control. The control value in the table T1 is specified. Then, based on the temperature of the processing solution 2216 measured by the temperature sensor 2227, the correction coefficient is specified with reference to the correction table T2.

  For example, when the type of the sheet 8 is “P” and the measured temperature is “12 ° C.”, the value obtained by multiplying the rotation speed “P1” of the first motor 2225 by the coefficient “X1” is The rotation speed is controlled as 2225. Further, the rotation speed of the second motor 2226 is controlled based on a value obtained by multiplying the peripheral speed ratio “P2” by the coefficient “Y1”. As a result, as the temperature of the treatment liquid 2216 increases, the coating speed can be increased and the peripheral speed ratio can be increased.

  Although the processing liquid application unit 210 measures the temperature of the processing agent liquid 2216 in the liquid in the supply liquid chamber 2209, the same control can be performed by measuring the environmental temperature near the liquid. . Accordingly, it is possible to follow the fluctuation of the optimum application amount due to the temperature change of the processing agent liquid 2216.

  According to the printing system 1000 including the processing liquid application device 200 and the printer 300 in the above-described embodiment, the range in which the application amount of the processing liquid 2216 can be varied according to the state of the image forming processing can be expanded. . Further, it is possible to cope with various types of sheets 8 with a small space and at low cost. Further, since the amount of the treatment agent liquid 2216 to be applied can be controlled to an appropriate amount, it is possible to prevent wasteful consumption of the liquid due to an excessive amount of application, and to prevent a jam due to excessive application.

  According to the printing system 1000 including the processing liquid application device 200 and the printer 300 in the present embodiment described above, it is possible to prevent a decrease in image quality due to an insufficient amount of the processing liquid 2216 applied.

  As described above, the invention made by the inventor has been specifically described based on the preferred embodiments. However, the present invention is not limited to the embodiments described above, and various modifications may be made without departing from the gist of the invention. It goes without saying that it is possible.

100: feeding device 200: processing liquid coating device 210: carry-in unit 220: processing liquid coating unit 230: processing liquid supply unit 240: unloading unit 250: transport path 300: printer 310: image forming unit 320: drying unit 400: medium Discharge device 1000: printing system 2201: transfer roller treatment liquid application section 2201: transfer roller 2202: TR arm 2203: TR spring 2204: application roller 2205: swing fulcrum 2206: TR cam 2207: cam motor 2208: pumping roller 2209: supply liquid Chamber 2210: Arm 2211: Pin 2212: Compression spring 2213: Fluid chamber swing fulcrum 2214: Cam 2215: Third motor 2216: Processing agent liquid 2217: First measuring roller 2218: Liquid level sensor 2225: First motor 2226: First Two motors 2227: medium sensor 2228: Second measuring roller 2319: Supply valve 2320: Supply pump 2321: Supply tank 2322: Drain pump 2323: Drain valve 2324: Drain tank

JP 2012-196955 A JP 2006-346924 A JP 2014-34167 A

Claims (9)

An image forming unit that forms an image by discharging droplets while conveying a recording medium,
A processing liquid application unit that applies a processing liquid to the recording medium while conveying the recording medium before the image is formed,
A control unit that controls an image forming transport speed that is a speed at which the recording medium is transported in the image forming unit, and a liquid coating transport speed that is a speed at which the recording medium is transported in the processing liquid coating unit;
With
The control unit controls the liquid application transport speed to be equal to or higher than the image forming transport speed,
An image forming apparatus comprising: The control unit can arbitrarily change the liquid application transport speed while keeping the image forming transport speed constant,
The image forming apparatus according to claim 1, wherein: The treatment liquid application unit,
A pump roller that rotates in a state of being immersed in the processing liquid stored in the liquid supply pan and pumps up the processing liquid;
An application roller that receives the processing liquid from the pumping roller with a nip formed between the pumping roller and
A transfer roller that forms a nip between the coating roller and the recording medium via the recording medium, and transfers the processing liquid from the coating roller to the recording medium,
And a first drive unit that rotationally drives the application roller,
The control unit controls the first drive unit, and applies the treatment liquid to the recording medium by applying the treatment liquid to the recording medium by rotating the application roller based on a driving force from the first drive unit. Transport at the coating transport speed,
The image forming apparatus according to claim 1. A second drive unit that rotationally drives the pumping roller,
The control unit controls the rotation speed of the pumping roller by the second drive unit according to the rotation speed of the application roller by the first drive unit,
The image forming apparatus according to claim 3. A storage unit that stores an application amount data table that holds application amount data that is data for defining the liquid application conveyance speed at which the application amount of the processing liquid for each type of the recording medium is an optimal amount; With
The control unit controls the liquid application transport speed based on the application amount data and the image forming transport speed read from the application amount data table,
The image forming apparatus according to claim 1. The control unit controls the liquid application conveyance speed to be slower as the type of the recording medium is more likely to permeate the processing liquid, and the liquid application conveyance speed is lower as the type of the recording medium is less likely to permeate the processing liquid. Control to increase the speed,
The image forming apparatus according to claim 5. A temperature sensor for measuring a temperature of the processing liquid,
The control unit controls the liquid application transfer speed based on the temperature,
The image forming apparatus according to claim 1. The control unit controls the liquid application conveyance speed to increase as the temperature of the processing liquid increases,
The image forming apparatus according to claim 7. An image forming apparatus including an image forming unit that forms an image by discharging droplets while conveying a recording medium,
A processing liquid application unit that includes a processing liquid application unit that applies the processing liquid to the recording medium and a control unit that controls the operation of the processing liquid application unit;
An image forming system having
The processing liquid application unit and the control unit are the processing liquid application unit and the control unit according to any one of claims 1 to 8,
An image forming system, characterized in that: