Patent Grant
9364847
The present application claims priority pursuant to 35 U.S.C. ยง119(a) from Japanese patent application number 2014-120742, filed on Jun. 11, 2014, the entire disclosure of which is incorporated by reference herein.
1. Technical Field
Exemplary embodiments of the present invention relate to a liquid coating device, a liquid coating device control method, and an image forming system including the liquid coating device, and in particular, to a method of preventing deterioration of a coating liquid.
2. Related Art
With advancing digitization of information, electronic information needs to be output via a printer or a facsimile machine, making image processing devices such as scanners indispensable. Such image processing devices include, for example, imaging, image forming, and communication functions, and therefore can be used as a printer, a facsimile machine, and a copier.
Among these image processing devices, the image forming apparatus used for outputting electronic documents should avoid adversely affecting image quality, such as bleeding, density fluctuation, color tone fluctuation, and bleed-through. For improved image quality, a technology to coat print media with a treatment liquid to concentrate color material of the ink is known. In such a technology, a squeeze roller is disposed in a container and rotates while being soaked in the treatment liquid, so that the treatment liquid is applied to the coating roller and a target object such as a paper roll is coated.
In addition, to ease maintenance when using only some of the functions that the image processing apparatus employs, when a command to disable either printing or reading is received from an external device, the process moves to a function disabling mode to disable the subject function. In this function disabling mode, even if an error is detected related to the disabled function, and the image processing apparatus does not report the error to the external device.
In a liquid coating applicator to apply the treatment liquid in the image forming apparatus, the treatment liquid is contained in a container so that applying the treatment liquid is smoothly performed. As a result, in the image forming process, even though the liquid coating applicator is disabled, because the container is filled with the treatment liquid, the treatment liquid remaining in the container without being consumed is exposed to air and deteriorates.
Such a problem is not limited to the treatment liquid in the image forming apparatus, but may occur as long as the apparatus includes a liquid coating applicator to apply a liquid that may deteriorate upon contact with air.
In one embodiment of the disclosure, there is provided an optimal liquid coating device including a container to store a liquid; a liquid reservoir having a greater air-tightness than that of the container; a liquid coating applicator to apply the liquid stored in the container to a target object; a liquid conveyer to convey the liquid stored in the container to the liquid reservoir; and a controller to control operation of the liquid coating device. When the liquid coating applicator is disabled, the controller conveys the liquid stored in the container to the liquid reservoir.
In one embodiment of the disclosure, there is provided an optimal image forming system including an image forming device to form an image by discharging color material to a target object; and a liquid coating device to apply a liquid to the target object before outputting the formed image. The liquid coating device includes a container to store the liquid; a liquid reservoir; a liquid coating applicator to apply the liquid stored in the container to the target object; a liquid conveyer to convey the liquid stored in the container to the liquid reservoir having a higher air-tightness than that of the container; and a controller to control operation of the liquid coating device. When the liquid coating applicator is disabled, the controller conveys the liquid stored in the container to the liquid reservoir.
In one embodiment of the disclosure, there is provided an optimal method of controlling a liquid coating device including applying a liquid stored in a container to a target object, by a liquid coating applicator; conveying the liquid stored in the container to a liquid reservoir having a higher air-tightness than that of the container, by a liquid conveyer; and conveying the liquid stored in the container to the liquid reservoir when the liquid coating applicator is disabled.
These and other objects, features, and advantages of the present invention will become apparent upon consideration of the following description of the preferred embodiments of the present invention when taken in conjunction with the accompanying drawings.
Referring now to drawings, preferred embodiments of the present invention will be described in detail. In the present embodiment, an image forming system including an inkjet-type image forming apparatus employing a paper roll or a rolled sheet includes a liquid coating device to coat a liquid onto a sheet surface before outputting image by the image forming apparatus.
In the structure illustrated in
With this, ink bleed discharged on the paper roll S, density fluctuation, color tone fluctuation, and bleed-through are prevented, thereby improving printing quality and shortening the time required for drying, so that printing productively is improved. That is, the treatment liquid functions as a fixing agent. In the present embodiment, the pretreatment liquid coating device 2 coats a treatment liquid on the paper roll. However, the coating target is not limited to paper but may be film, plastic sheet, etc.
A feed-in roller 202 is a roller driven to rotate by a drive source such as a motor. The feed-in roller 202 is pressed by a feed-in nip roller 203 with pressure via an elastic force of the elastic member such as a spring. When the feed-in roller 202 is driven to rotate, the paper roll S nipped by the feed-in nip roller 203 and the feed-in roller 202 is pulled in from the pretreatment device 1 disposed upstream of the pretreatment liquid coating device 2. The paper roll S fed and conveyed downstream by the feed-in roller 202 and the feed-in nip roller 203 is tension-released and is bending, so that an air loop 204 is formed.
The paper roll S that has passed through the air loop 204 passes between a pass shaft 205 and an edge guide 206. As illustrated in
A pair of edge guides 206 is supported by the pass shaft 205 and includes two guide plates 206a, 206b, that are so disposed as to have each surface thereof substantially parallel to each other, and a distance between the guide plates 206a, 206b is substantially the same as the width of the paper roll S in the main scanning direction. As a result, travelling position of the paper roll S in the main scanning direction corresponds to a position of the edge guide 206, so that a stable conveyance is possible.
A fixedly mounted tension shaft 207 maintains tension on the paper roll S that has passed through a position between the pass shaft 205 and the edge guide 206 sufficient to secure stability in the conveyance. The paper roll S that has passed through the tension shaft 207 further passes through a position between an in-feed roller 208 and a feed nip roller 209.
A plurality of feed nip rollers 209 is provided along a shaft direction of the in-feed roller 208 and presses against the in-feed roller 208 via an elastic force such as a spring.
The paper roll S that has passed through a portion between the in-feed roller 208 and the feed nip roller 209 is wound around a rotatable dancer roller 210 from a bottom side thereof. The dancer roller 210 is rotatably disposed on a movable frame 211 via a shaft bearing disposed at an end of the roller. The dancer roller 210 and the frame 211 form a dancer roller unit 212.
Specifically, the dancer roller unit 212 is hung from the paper roll S. The dancer roller unit 212 is movable along a vertical direction as indicated by an arrow A in
The paper roll S that has passed through the dancer roller 210, further passes through a front surface coating applicator 213f, where a treatment liquid is coated on a front surface of the paper roll S, and further passes through a rear surface coating applicator 213r, where a treatment liquid is applied on a rear surface of the paper roll S reversed by a guide roller 201, so that both surfaces of the paper roll S are coated with a treatment liquid. Details of the coating applicators will be described later below.
The paper roll S that has passed through the coating applicators, further passes through a position between an out-feed roller 214 and another feed nip roller 209. A plurality of feed nip rollers 209 is disposed along a shaft direction of the out-feed roller 214, and is pressed against the out-feed roller 214 via an elastic force of a spring, for example. When the out-feed roller 214 is driven to rotate by the drive source such as a motor, the paper roll S is conveyed while being nipped between the out-feed roller 214 and the feed nip roller 209.
Rotatable dancer rollers 215a, 215b are disposed downstream of the out-feed roller 214 and the feed nip roller 209, and the guide rollers 201 are alternately disposed together with two dancer rollers, so that a W-shaped conveyance path of the paper roll S is constructed as illustrated in
The dancer rollers 215a, 215b are rotatably disposed on a movable frame 216 via a shaft bearing disposed at lateral ends of the roller. The dancer rollers 215a, 215b and the movable frame 216 form a dancer roller unit 217. Specifically, the dancer roller unit 217 is hung from the paper roll S. The dancer roller unit 217 is movable along a vertical direction as indicated by an arrow A in
In addition, another dancer roller sensor is disposed in a range where the dancer roller unit 217 moves. The drive source of the out-feed roller 214 is controlled to move the roller faster or slower based on a detection signal from the dancer roller sensor, so that a position of the dancer roller unit 217 is adjusted.
After having passed through an inside of the pretreatment liquid coating device 2, the paper roll S is fed into the inkjet printer 3 disposed downstream of the pretreatment liquid coating device 2.
Next, a schematic configuration of the pretreatment liquid coating device 2 will be described from a view of the supply path of the treatment liquid to the front surface coating applicator 213f and the rear surface coating applicator 213r.
As illustrated in
The rear surface coating applicator 213r is configured similarly to the front surface coating applicator 213f illustrated in
The supply pan 224 is configured to cover the coating roller 221, so that evaporation of the treatment liquid inside the supply pan 224 is restricted. However, a pressed portion between the coating roller 221 and the pressure roller 223 needs to be kept open, so that the supply pan 224 is not completely closed.
Thus, as illustrated in
The electromagnetic valve 229 is open when the pretreatment liquid coating device 2 is not powered on, when the printing process is suspended for more than the one hour required for replacement of the paper roll S, change of the printing pattern, and the like. With this structure, even when the printing process is suspended, filling the treatment liquid into the supply pan 224 won't take much waiting time.
In addition, viscosity of the treatment liquid in the reserve tank 228 increases when the treatment liquid is not used for a long time period (for example, more than several weeks). When the treatment liquid in the reserve tank 228 is not used for more than a predetermined time period, an electromagnetic valve 234 disposed on a path 302 that communicates the reserve tank 228 with a waste liquid tank 233 is released to open. With this structure, the treatment liquid inside the reserve tank 228 is collected into the waste liquid tank 233, so that the treatment liquid is kept fresh.
In addition, a circulation path 303f (303r) from the evacuation path 301f (301r) communicating with a filter 230 is branched. In the circulation path 303f (303r), an electromagnetic valve 231f (231r) is disposed upstream of the filter 230 and a tridirectional valve 235 is disposed downstream of the filter 230. The filter 230 removes paper dust accumulating inside the supply pan 224 and prevents the treatment liquid from becoming a paste-like solution. The paper dust accumulating inside the supply pan 224 is produced due to slidable movement of the paper roll S sliding on the coating roller 221 and the pressure roller 223.
When the electromagnetic valve 231f (231r) is opened while the treatment liquid is being coated, part of the treatment liquid inside the supply pan 224 passes through the filter 230 via the evacuation path 301f (301r) and the circulation path 303f (303r), so that the paper dust and the like included in the treatment liquid is removed. As a result, the tridirectional valve 235 is brought to a state in which the filter 230 and a supply pump 225 communicate, and an electromagnetic valve 227 disposed on a supply path 305f (305r) that communicates the supply pump 225 with the supply pan 224 is released. With this structure, when a filter pump 237 and the supply pump 225 are driven, the treatment liquid from which paper dust is removed by the filter 230 is supplied to the supply pan 224 by the supply pump 225 via paths 304, 305f (305r).
The liquid level sensor that detects a liquid level inside the supply pan 224 detects that the liquid level inside the supply pan 224 is below a predetermined amount, that is, a low level, the treatment liquid is replenished from the reserve tank 228 or from a cartridge 226 to the supply pan 224.
When the treatment liquid is supplied from the reserve tank 228 to the supply pan 224, the electromagnetic valve 232 is open and the treatment liquid stored in the reserve tank 228 is fed from a circulation supply path 306 that communicates the reserve tank 228 with the filter 230 to the filter 230. As a result, the tridirectional valve 235 is brought to a state in which the filter 230 and the supply pump 225 are communicated, and the electromagnetic valve 227 disposed on the supply path 305f (305r) that communicates the supply pump 225 with the supply pan 224 is released. With this structure, when the supply pump 225 is driven, the treatment liquid that has passed through the filter 230 is supplied by the supply pump 225 via the paths 304, 305f (305r), and is supplied to the supply pan 224.
On the other hand, when the treatment liquid is supplied from the cartridge 226 to the supply pan 224, the electromagnetic valve 236 is released and the tridirectional valve 235 is brought to a state in which the cartridge 226 and the supply pump 225 are communicated and the electromagnetic valve 227 disposed on the supply path 305f (305r) that communicates the supply pump 225 with the supply pan 224 is released. With this structure, when the supply pump 225 is driven, the treatment liquid that is stored in a cartridge 226 is supplied by the supply pump 225 via the paths 307, 305f (305r), and is supplied to the supply pan 224 by the supply pump 225.
Whether the treatment liquid is supplied from the reserve tank 228 or the cartridge 226 to the supply pan 224 is determined based on a predetermined priority. For example, when the reserve tank 228 has a higher priority order, if the liquid level of the treatment liquid inside the reserve tank 228 is more than the predetermined level, the treatment liquid is supplied from the reserve tank 228 to the supply pan 224. When the liquid level of the treatment liquid inside the reserve tank 228 is below the predetermined level, the treatment liquid is switched to be supplied from the cartridge 226 to the supply pan 224.
When the liquid level sensor of the supply pan 224 detects that the liquid level inside the supply pan 224 is below a low level, the treatment liquid is started to be supplied, and when the liquid level sensor detects that the liquid level inside the supply pan 224 is more than a predetermined amount, that is, a high level, a supply of the treatment liquid to the supply pan 224 is stopped.
In the present embodiment, a case in which the liquid level sensor detects whether the liquid level inside the supply pan 224 is a low level or high level has been described. However, the above is one example, and the liquid level sensor may be configured to detect a liquid level to supply the treatment liquid to the supply pan 224, a liquid level to start coating operation of the treatment liquid, and a liquid level to stop supply of the treatment liquid to the supply pan 224, each as a different level.
The control unit 240 is configured as a combination of software and hardware. Specifically, the control unit 240 is formed of a software controller including a central processing unit (CPU) computing in accordance with a control program such as firmware stored in a read only memory (ROM), non-volatile memory, non-volatile random access memory (NV-RAM), optical disk, and the like, and hardware such as ICs.
As illustrated in
The sensor controller 243 obtains a detection signal output from the liquid level sensor 251 and inputs the signal data to the main controller 241. The valve controller 244 controls opening and closing of the electromagnetic valves 227f, 227r (hereinafter, treatment liquid supply valves 227f, 227r) in accordance with the main controller 241, and controls supplying treatment liquid to the supply pan 224. The valve controller 244 controls opening and closing of the electromagnetic valves 229f, 229r (hereinafter, treatment liquid retreat valves 229f, 229r) in accordance with the main controller 241, and controls retreating the treatment liquid from the supply pan 224 to the reserve tank 228.
The coating controller 245 controls rotation of the squeeze roller 222 and the coating roller 221 in accordance with the main controller 241, and controls supplying the treatment liquid from the squeeze roller 222 to the coating roller 221 and coating the treatment liquid by the coating roller 221. The input controller 246 obtains input signals from a user interface (UI) 252 such as a touch panel or a keyboard, and inputs those signals to the main controller 241. The input signals include commands to disable or enable usage of the front surface coating applicator 213f and the rear surface coating applicator 213r.
The error controller 247 detects an error such as a failure that takes place in each section such as the coating roller 221, the squeeze roller 222, and the liquid level sensor 251 that construct the front surface coating applicator 213f and the rear surface coating applicator 213r, and inputs the error result to the main controller 241. In addition, the error controller 247 controls error detection and negates an error of a designated section in the pretreatment liquid coating device 2 in accordance with the control of the main controller 241, so that the error, if detected, is not input to the main controller 241.
In such a structure, one of the optimal controls performed in the present embodiment includes retreating control of the treatment liquid by the valve controller 244 when usage of the front surface coating applicator 213f and the rear surface coating applicator 213r is disabled. Hereinafter, among operation by the main controller 241, retreating control of the treatment liquid according to the present embodiment will be described.
As illustrated in
When use of the front surface coating applicator 213f is enabled (NO in S501), the main controller 241 waits (No in S502) until timing to supply treatment liquid to the supply pan 224f (Yes in S502) is determined. For example, the main controller 241 determines that the treatment liquid should be supplied to the supply pan 224f when power to the pretreatment liquid coating device 2 is on, or when the liquid coating process of the front surface coating applicator 213f starts after the treatment liquid of the supply pan 224f is retreated in the reserve tank 228.
When the main controller 241 determines that the treatment liquid should be supplied to the supply pan 224f (Yes in S502), the main controller 241 causes the valve controller 244 to control the treatment liquid supply valve 227f, so that the treatment liquid is supplied from the reserve tank 228 or from the cartridge 226 to the supply pan 224f (S503). The valve controller 244 controls the tridirectional valve 235, the electromagnetic valve 232 (when supplying the treatment liquid from the reserve tank 228), and the electromagnetic valve 236 (when supplying the treatment liquid from the cartridge 226), in addition to the treatment liquid supply valve 227f.
The main controller 241 that has controlled supplying the treatment liquid to the supply pan 224f, determines whether the front surface coating applicator 213f is disabled or not (S504). When the front surface coating applicator 213f is enabled (NO in S504), the main controller 241 waits (No in S505) until timing to start coating the treatment liquid to the supply pan 224f (Yes in S505) is determined. For example, the main controller 241 determines that the coating of the treatment liquid should be started when a command to perform coating is received from an upper device of the pretreatment liquid coating device 2 such as an inkjet printer 3.
When the main controller 241 determines that the liquid coating process should be started (Yes in S505), the main controller 241 causes the coating controller 245 to start rotating the squeeze roller 222f so that the front surface coating applicator 213f starts to perform the liquid coating process (S506). Then, the main controller 241 returns to the step S501 to perform the subject process repeatedly.
On the other hand, when the front surface coating applicator 213f is disabled (Yes in S501 or Yes in S504), the main controller 241 causes the valve controller 244 to control the treatment liquid retreating valve 229f, so that the treatment liquid stored in the supply pan 224f is retreated to the reserve tank 228 (S507).
In addition, when the liquid level sensor 251 detects that the treatment liquid inside the supply pan 224f is below the low level, the main controller 241 controls such that the treatment liquid is not supplied from the reserve tank 228 or from the cartridge 226 to the supply pan 224f (S508). In addition, the main controller 241 controls the coating controller 245 not to perform the liquid coating process (S508). Steps S507 and S508 are not limited to this order, these may be performed in reverse order, and may be done in parallel.
After the treatment liquid is retreated in the reserve tank 228 and the supply of the treatment liquid is disabled, the main controller 241 maintains a state when the front surface coating applicator 213f is disabled (No in S509) until the front surface coating applicator 213f is enabled (Yes in S509). When the front surface coating applicator 213f is changed from the disabled setting to the enabled setting (Yes in S509), the main controller 241 enables the supply of the treatment liquid and the liquid coating process (S510), so that processes from S502 are repeated.
In the present embodiment, in step S510, the main controller 241 enables the supply of the treatment liquid and the liquid coating process, and the processes from S502 are repeated. However, after S510, the process may proceed to S501 and determination whether the use is disabled or not may be done again.
As illustrated in
On the other hand, for example, when the front surface coating applicator 213f employing the supply pan 224f is disabled, there is no need of storing the treatment liquid in the supply pan 224f for the start of liquid coating process. Therefore, when the front surface coating applicator 213f is disabled, the treatment liquid stored in the supply pan 224f is preferably retreated in the reserve tank 228 swiftly. Due to this, the period during which the treatment liquid stays in the supply pan 224f is shortened, thereby preventing the deterioration of the treatment liquid.
Next, among operation of the main controller 241, operation of error detection control relative to the front surface coating applicator 213f and the rear surface coating applicator 213r serving as liquid coating applicators by the main controller 241 will be described.
As illustrated in
If the front surface coating applicator 213f is enabled (No in S702), the main controller 241 causes the error controller 247 to perform error checking of each component of the front surface coating applicator 213f. If an error such as failure occurrence is detected (Yes in S703), an error process is performed (S704). The error process includes, for example, a process in which an output controller has the UI 252 report that the error is detected, or alternatively, report the error to an upper device. On the other hand, when the error is not detected (No in S703), the main controller 241 returns to the step S702 to perform the subject process repeatedly.
On the other hand, if the front surface coating applicator 213f is disabled (Yes in S702), the main controller 241 causes the error controller 247 not to perform error checking of each component of the front surface coating applicator 213f. If the main controller 241 causes the error controller 247 not to perform error checking, the main controller 241 maintains a control state when the use is disabled (No in S707) until the front surface coating applicator 213f is enabled (Yes in S707). When the front surface coating applicator 213f is changed from the disabled setting to the enabled setting (Yes in S707), the main controller 241 enables the error checking (S708) so that processes from S701 are repeated.
In the above configuration, when the front surface coating applicator 213f is disabled, the main controller 241 causes the error controller 247 not to perform error checking of each component of the front surface coating applicator 213f. However, this kind of process is simply an example. The main controller 241 may control the error controller 247 not to input an error detection result to the main controller 241 even though an error has been detected, instead of the control not to perform error checking. In brief, any disabling control against the failure that has occurred to each component of the use-disabled front surface coating applicator 213f may only be possible.
As described above, in the image forming system including the pretreatment liquid coating device 2 according to the present embodiment, if the coating applicators 213f, 213r is disabled, the controller to control operation of the pretreatment liquid coating device 2 conveys the treatment liquid stored in the supply pan 224 to the reserve tank 228 that has more air-tightness than that of the supply pan 224. With this structure, deterioration of the treatment liquid stored in the supply pan 224 of the coating applicator of which use is disabled can be prevented.
In addition, the structure as described in the present embodiment is not limited to the treatment liquid in the image forming apparatus may be applied similarly to the system including a liquid coating device to apply a liquid that is apt to deteriorate up contact with air. Accordingly, the structure related to the present embodiment may prevent a liquid stored in a container from deteriorating even though the coating applicator is disabled.
In the image forming system including the pretreatment liquid coating device 2 according to the present embodiment, if the liquid coating device, that is, the coating applicators 213f, 213r is disabled, the controller to control operation of the pretreatment liquid coating device 2 disables a process related to the failure occurred to the liquid coating device of which usage is disabled. Conventionally, when the error was detected in any device by error checking, an entire operation of the pretreatment liquid coating device 2 stops. Accordingly, even though a failure occurs to the liquid coating applicator that is disabled, the pretreatment liquid coating device 2 itself was not useable and was therefore inconvenient.
With such a structure, when the liquid coating applicator is disabled, the error controller 247 does not perform error checking of the liquid coating applicator, neglects even an error that has been found, or disables the error checking, so that an event in which the whole apparatus cannot be used due to an error of the unused liquid coating applicator can be avoided.
In the above embodiment, a case in which the pretreatment liquid coating device 2 includes two liquid coating applicators, that is, the front surface coating applicator 213f and the rear surface coating applicator 213r, has been described. The above configuration is an example, and similar operation can be possible even in a case in which the pretreatment liquid coating device 2 includes one only liquid coating applicator. In this case, when the liquid coating applicator is disabled, the paper roll is conveyed to the inkjet printer 3 without the treatment liquid being applied thereto in the pretreatment liquid coating device 2.
In the above embodiment, a case in which the coating applicator 213 is disabled in response to the input signal from the UI 252 has been described. Alternatively, when the error controller 247 detects an error in the coating applicator 213, the malfunctioning coating applicator 213 is disabled.
Additional modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2014-120742 | Jun 2014 | JP | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 20130106946 | Sunaoshi | May 2013 | A1 |
| Number | Date | Country |
|---|---|---|
| 2013-073440 | Apr 2013 | JP |
| 2014-019028 | Feb 2014 | JP |
| Number | Date | Country | |
|---|---|---|---|
| 20150360254 A1 | Dec 2015 | US |
