Drying device, drying system, and image forming apparatus

Abstract

To appropriately manage humidity inside a housing.SOLUTION: A drying device includes: an airflow fan 44 to move air inside a housing 41 to generate an airflow passing a connection terminal 43a; an exhaust fan 45 to discharge air inside the housing 41 to an outside of the housing 41 through an exhaust opening 41a; a duct fan 46 to discharge air inside the housing 41 through an exhaust duct DC connected to a connection opening 41b; and a control unit (control means) to control operations of the airflow fan 44, the exhaust fan 45, and the duct fan 46 on the basis of a detected humidity by a humidity sensor 43c.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a drying device, a drying system, and an image forming apparatus.

Background Art

[0002] For example, in an image forming apparatus using an inkjet method or an electrophotographic method, excessive humidity in the housing causes condensation, which is not preferable. Therefore, in order to suppress the occurrence of condensation, an air flow is generated at a location where condensation is likely to occur, or excessive moisture in the housing is discharged outside the housing. For example, the image forming apparatus described in Patent Document 1 includes a cartridge fan for preventing condensation on the emission surface (dust-proof glass) of the laser light provided in the scanner unit, and an exhaust path fan for discharging the vapor generated in the fixing device outside the housing.

[0003] The image forming apparatus described in Patent Document 1 is a so-called consumer image forming apparatus. A consumer image forming apparatus is, for example, a copying machine, a printer, a facsimile machine, which are widely spread in offices and homes and used by general consumers, and a multifunction machine having a plurality of these functions. In a consumer image forming apparatus, since the amount of image formation per unit time is not large and the amount of moisture evaporated from the recording medium is not large, the inside of the housing can be maintained at an appropriate humidity by operating the cartridge fan and the exhaust path fan.

Summary of the Invention

Problems to be Solved by the Invention

[0004] In addition to consumer image forming apparatuses, there are industrial image forming apparatuses for image forming apparatuses. An industrial image forming apparatus is, for example, an image forming apparatus used for manufacturing as a printing business. Generally, in an industrial image forming apparatus, the amount of image formation per unit time is larger than that of a consumer image forming apparatus, and the amount of liquid evaporated from the recording medium is also larger than that of a consumer image forming apparatus. Industrial image forming apparatuses are more likely to have increased humidity inside the housing compared to consumer image forming apparatuses. To manage the humidity inside the housing of an industrial image forming apparatus, it is effective to enhance the air discharge capacity inside the housing. However, simply increasing the number of fans or using a large fan with high exhaust capacity alone is not preferable because it increases the noise generated during operation and the power consumption. The present invention has been made in view of such circumstances, and an object thereof is to appropriately manage the humidity inside the housing.

Means for Solving the Problems

[0005] To solve the above problems, a drying apparatus according to the present invention includes a housing provided with an exhaust opening and a connection opening, a transport mechanism housed in the housing for transporting a recording medium along a transport path, a heater housed in the housing for heating the recording medium on the transport path, a connection terminal for connecting wiring routed from outside the housing inside the housing, a humidity detection means for detecting the humidity inside the housing, a flow fan for flowing the air inside the housing so that a flow of air passes through the connection terminal, an exhaust fan for discharging the air inside the housing to the outside of the housing through the exhaust opening, a duct fan for discharging the air inside the housing through an exhaust duct connected to the connection opening, and a control means for controlling the operations of the flow fan, the exhaust fan, and the duct fan based on the detected humidity of the humidity detection means.

Effects of the Invention

[0006] According to the present invention, the humidity inside the housing can be appropriately managed.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Mode for Carrying Out the Invention

[0008] <Outline of Image Forming Apparatus 1> FIG. 1 is a schematic diagram showing the overall configuration of an image forming apparatus 1 according to an embodiment of the present invention. First, the outline of the image forming apparatus 1 will be described with reference to FIG. 1. In the following description, an industrial image forming apparatus 1 (drying apparatus) that forms an image on a continuous paper LP (recording medium) such as continuous forms will be taken as an example, but the present invention can also be applied to other types of image forming apparatuses. For example, even in a consumer image forming apparatus, if the amount of liquid evaporated from the recording medium is large compared to image forming apparatuses that are widely used, and the apparatus discharges air inside the housing 41 (see FIG. 2) through the duct DC, the present invention can be applied. Also, the components, types, combinations, shapes, relative arrangements, etc. described in the following embodiments are merely illustrative examples and not intended to limit the scope of the present invention only thereto, unless otherwise specifically described.

[0009] The image forming apparatus 1 illustrated in FIG. 1 includes a loading unit 2 into which a continuous paper LP before image formation wound in a roll is loaded and which sequentially feeds out the loaded continuous paper LP, a preprocessing unit 3 that performs preprocessing on the continuous paper LP fed out from the loading unit 2, a preprocessing drying unit 4F that dries the preprocessed continuous paper LP, a guiding unit 5 that guides the continuous paper LP discharged from the preprocessing drying unit 4F downstream along the conveyance direction, an image forming unit 6 that forms an image on the continuous paper LP discharged from the guiding unit 5, a postprocessing unit 7 that performs postprocessing on the continuous paper LP after image formation, a postprocessing drying unit 4R that dries the postprocessed continuous paper LP, a discharging unit 8 that winds up the continuous paper LP discharged from the postprocessing drying unit 4R in a roll and discharges the rolled continuous paper LP, and a control unit 9 (control means) that controls each unit. In the image forming apparatus 1 of FIG. 1, the combination of the preprocessing drying unit 4F and the control unit 9, and the combination of the postprocessing drying unit 4R and the control unit 9 correspond to the drying apparatus according to the present invention.

[0010] In the present embodiment, since the preprocessing drying unit 4F and the postprocessing drying unit 4R have the same configuration, they will be described together as the drying unit 4. FIG. 2 is a schematic diagram showing the configuration of the drying unit 4. As shown in FIG. 2, the drying unit 4 includes a housing 41 provided with an exhaust opening 41a and a connection opening 41b, a transport mechanism 42b housed in the housing 41 for transporting the continuous paper LP along the transport path CR, a heat roller 42c (heater) housed in the housing 41 for heating the continuous paper LP on the transport path CR, a connection terminal 43a for connecting the wiring PL for the heat roller 42c routed from outside the housing 41 inside the housing 41, a humidity sensor 43c (humidity detection means) for detecting the humidity inside the housing 41, and a plurality of types of fans 44, 45, 46 provided inside the housing 41.

[0011] The plurality of types of fans 44, 45, 46 included in the drying unit 4 include a flow fan 44 that flows the air inside the housing 41 so that, for example, a flow of air passing through the connection terminal 43a is generated, an exhaust fan 45 that discharges the air inside the housing 41 to the outside of the housing 41 through the exhaust opening 41a, and a duct fan 46 that discharges the air inside the housing 41 to the outside of the room RM (see FIG. 1) or the outside of the building through an exhaust duct DC connected to the connection opening 41b, but may include other fans. The control unit 9 (see FIG. 1) controls the operations of the flow fan 44, the exhaust fan 45, and the duct fan 46 based on the detected humidity of the humidity sensor 43c. Thereby, it is possible to generate a flow of air passing through the connection terminal 43a inside the housing 41, and to select the discharge destination of the air inside the housing 41 between the outside of the housing 41 (room RM) and the exhaust duct DC (outside the room RM). As a result, the humidity inside the housing 41 can be appropriately managed.

[0012] <Details of the image forming apparatus 1> Hereinafter, with reference to FIGS. 1 to 4, the configuration of the image forming apparatus 1 will be described. FIG. 3 is a block diagram showing the configuration of the image forming apparatus 1, and FIG. 4 is a flowchart showing each process performed by the image forming apparatus 1. As shown in FIG. 3, the control unit 9 includes a CPU (Central Processing Unit) 9a as a central control device, a memory 9b that stores the operation program of the CPU 9a and various types of information, and an I / F (interface) 9c for communication, and is configured to be able to control each part included in the loading unit 2, the pre-processing drying unit 4F, the image forming unit 6, the post-processing unit 7, the post-processing drying unit 4R, and the unloading unit 8.

[0013] The loading unit 2 shown in FIG. 1 includes a feeding unit 2a that holds the continuous paper LP wound in a roll shape so as to be feedable, and a guide roller 2b that guides the continuous paper LP fed from the roll-shaped portion. The feeding unit 2a is, for example, a cylindrical member into which the central cavity of the continuous paper LP wound in a roll shape is inserted, and is rotationally driven by a feeding motor 2c shown in FIG. 3. The operation of the feeding motor 2c is controlled by the control unit 9. A plurality of guide rollers 2b are provided on the conveyance path CR of the continuous paper LP, and guide the continuous paper LP along the conveyance path CR while controlling the slack of the continuous paper LP so that wrinkles do not occur. The continuous paper LP is a type of recording medium, and in this embodiment, it is, for example, a long paper with perforations that can be cut formed at predetermined intervals, but is not limited thereto.

[0014] The pre-processing unit 3 receives the continuous paper LP fed from the loading unit 2 and performs pre-processing of applying the pre-processing liquid PS to the surface of the continuous paper LP. The pre-processing unit 3 of this embodiment includes, for example, a storage container 31 that stores the pre-processing liquid PS, a thinning roller 32 disposed in the storage container 31, an application roller 33 that abuts on the thinning roller 32 from above, a platen roller 34 that abuts on the application roller 33 from above, and a plurality of guide rollers 35 that guide the continuous paper LP in the pre-processing unit 3. The continuous paper LP is guided along the conveyance path CR by a plurality of guide rollers 35, and is nipped (held in a conveyable manner) by an application roller 33 and a platen roller 34 that are rotatable about the axis center in the middle of the conveyance path CR. The pretreatment liquid PS is applied to the surface of the continuous paper LP by the application roller 33. For example, the pretreatment liquid PS is transferred from the surface of the thinning roller 32 to the surface of the application roller 33, and then applied from the surface of the application roller 33 to the surface of the continuous paper LP. The applied pretreatment liquid PS is held on the surface of the continuous paper LP. In the present embodiment, the application amount of the pretreatment liquid PS to the continuous paper LP is determined according to, for example, the pressing force between the platen roller 34 and the application roller 33.

[0015] The drying section 4F for pretreatment is a part that dries the pretreatment liquid PS applied to the surface of the continuous paper LP. The details of the drying section 4F for pretreatment will be described later. The guide section 5 is provided between the drying section 4F for pretreatment and the image forming section 6, and guides the continuous paper LP discharged from the drying section 4F for pretreatment toward the image forming section 6 on the downstream side in the conveyance direction while controlling the slack of the continuous paper LP. For this reason, the guide section 5 includes a plurality of guide rollers 51. The continuous paper LP dissipates heat while passing through the guide section 5 and is adjusted to, for example, the ambient temperature (the temperature of the room RM where the image forming apparatus 1 is installed).

[0016] The image forming section 6 is a part that forms an image on the surface of the continuous paper LP discharged by the guide section 5. The image forming section 6 of the present embodiment adopts an inkjet method. For example, as shown in FIGS. 1 and 3, the image forming section 6 includes a head 6K that discharges black ink, a head 6C that discharges cyan ink, a head 6M that discharges magenta ink, and a head 6Y that discharges yellow ink. Each of the heads 6K, 6C, 6M, and 6Y includes a large number of nozzles formed at predetermined intervals, for example, along the width direction (the direction orthogonal to the conveyance direction) of the continuous paper LP, and ink droplets can be freely discharged from each nozzle. In the present embodiment, for example, the head 6K, the head 6C, the head 6M, and the head 6Y are arranged in order from the upstream side in the conveyance direction of the continuous paper LP.

[0017] The post-processing unit 7 performs post-processing of applying a post-processing liquid to the surface of the continuous paper LP discharged from the image forming unit 6. The post-processing unit 7 of the present embodiment includes, for example, a post-processing head 71 that discharges the post-processing liquid. The post-processing head 71 includes, for example, a large number of nozzles formed at predetermined intervals along the width direction of the continuous paper LP, and discharges the post-processing liquid in a droplet form from each nozzle. For example, the post-processing head 71 selectively discharges the post-processing liquid to the portion where the image is formed on the surface of the continuous paper LP, or discharges the post-processing liquid to the entire surface of the continuous paper LP. The post-processing liquid adhering to the surface of the continuous paper LP is fixed to the surface of the continuous paper LP by drying (evaporation of the solvent), and a post-processing layer is formed. The surface of the continuous paper LP is improved in abrasion resistance, glossiness, and storage stability (such as water resistance, light resistance, and gas resistance) by the formation of the post-processing layer.

[0018] The post-processing drying unit 4R is a portion that dries the post-processing liquid applied to the surface of the continuous paper LP. Details of the post-processing drying unit 4R will be described later. The discharging unit 8 includes a guide roller 8a that guides the continuous paper LP discharged from the post-processing drying unit 4R, and a winding unit 8b that winds the continuous paper LP guided by the guide roller 8a in a roll shape. A plurality of guide rollers 8a are provided on the conveyance path CR of the continuous paper LP, and guide the continuous paper LP so that it can move along the conveyance path CR while controlling the slack of the continuous paper LP. The continuous paper LP discharged from the post-processing drying unit 4R is radiated while moving along the conveyance path CR and adjusted to, for example, the ambient temperature. The winding unit 8b is, for example, a cylindrical member around which the continuous paper LP is wound, and is rotationally driven by a winding motor 8c shown in FIG. 3. The operation of the winding motor 8c is controlled by the control unit 9.

[0019] The roll-shaped continuous paper LP wound around the winding unit 8b is cut from the continuous paper LP at a position upstream of the roll-shaped continuous paper LP and then extracted from the winding unit 8b and carried out from the carrying-out unit 8. Thereafter, the cut end (downstream end) of the continuous paper LP is wound around the winding unit 8b, and image formation on the continuous paper LP is continued.

[0020] In the image forming apparatus 1 having the above configuration, as shown in FIG. 4, a feeding step S1 of the continuous paper LP by the feeding unit 2, a preprocessing step S2 by the preprocessing unit 3, a post-preprocessing drying step S3 by the preprocessing drying unit 4F, an image forming step S4 by the image forming unit 6, a post-processing step S5 by the post-processing unit 7, a post-post-processing drying step S6 by the post-processing drying unit 4R, and a winding step S7 of the continuous paper LP by the carrying-out unit 8 are sequentially performed to form an image on the surface of the continuous paper LP.

[0021] <Details of the drying unit 4> Next, the drying unit 4 (preprocessing drying unit 4F, post-processing drying unit 4R) will be described in detail. As shown in FIG. 2, the housing 41 of the drying unit 4 is provided with an exhaust opening 41a having an exhaust fan 45 for discharging the air inside the housing 41 to the outside of the housing 41, and an upstream end of an exhaust duct DC for discharging the air inside the housing 41 to the outside of the building where the image forming apparatus 1 is installed is connected, and a connection opening 41b provided with a duct fan 46 for discharging the air inside the housing 41 toward the exhaust duct DC.

[0022] The heating unit 42 accommodated in the housing 41 includes a transport mechanism 42b composed of a plurality of guide rollers 42a. The plurality of guide rollers 42a are members for guiding the continuous paper LP along a predetermined transport path CR, and are constituted by, for example, cylindrical members made of metal. A heat roller 42c is provided in the middle of the conveyance path CR. The heat roller 42c includes, for example, a cylindrical member 42d made of metal and a built-in heater 42e provided inside the cylindrical member 42d. The outer peripheral surface of the cylindrical member 42d is contacted by the continuous paper LP conveyed along the conveyance path CR. As shown in FIG. 3, the energization state of the heat roller 42c (built-in heater 42e) is controlled by the control unit 9. When the built-in heater 42e generates heat with energization, the heat of the built-in heater 42e is transmitted to the outer peripheral surface of the cylindrical member 42d and the temperature of the outer peripheral surface rises. The continuous paper LP is heated by contacting the outer peripheral surface of the cylindrical member 42d while being conveyed along the conveyance path CR. When the continuous paper LP is heated, the liquid (for example, the solvent of the pretreatment liquid PS or the solvent of the post-treatment liquid) held by the continuous paper LP evaporates. The humidity inside the housing 41 rises with the evaporation of the liquid.

[0023] An electrical component unit 43 is provided inside the housing 41. The electrical component unit 43 includes a terminal block 43b provided with a plurality of connection terminals 43a, a humidity sensor 43c for detecting the humidity inside the housing 41 (for example, the humidity near the connection terminals 43a), and a flow fan 44 for flowing the air inside the housing 41 so that a flow of air passing through the connection terminals 43a is generated. By generating a flow of air passing through the connection terminals 43a, the inconvenience of water droplets adhering to the connection terminals 43a due to condensation is suppressed. Wiring PL for the heat roller 42c routed from a switchboard or the like outside the housing 41 is connected to the plurality of connection terminals 43a. As the wiring PL for the heat roller 42c, one that can pass an electric current necessary for the operation of the built-in heater 42e is used. Note that the connection terminals 43a are not limited to those to which the wiring PL for the heat roller 42c is connected, and any wiring routed from the outside of the housing 41 may be connected. As shown in FIG. 3, the humidity sensor 43c is electrically connected to the control unit 9, and a detection signal from the humidity sensor 43c is input to the control unit 9. The control unit 9 can detect the humidity inside the housing 41, for example, the humidity near the electrical component unit 43, based on the detection signal from the humidity sensor 43c.

[0024] <Regarding each of the fans 44, 45, 46 provided in the drying unit 4> As described above, the drying unit 4 is provided with a flow fan 44, an exhaust fan 45, and a duct fan 46. The blowing capabilities of the respective fans 44, 45, 46 differ due to differences in their uses. For example, since the flow fan 44 only needs to generate an air flow through the connection terminal 43a, the fan with the lowest blowing capacity is used. Therefore, for the flow fan 44, a fan with less power consumption and a lower operating volume compared to the exhaust fan 45 and the duct fan 46 can be used. Since the exhaust fan 45 discharges the air inside the housing 41 to the outside of the housing 41 through the exhaust opening 41a, for example, into the room RM where the image forming apparatus 1 is installed, a fan with a medium blowing capacity is used. Therefore, for the exhaust fan 45, a fan with less power consumption and a lower operating volume compared to the duct fan 46 can be used. Since the duct fan 46 discharges the air inside the housing 41 to the outside of the housing 41 (for example, outside the building having the room RM) through the exhaust duct DC, the fan with the highest blowing capacity is used. Therefore, for the duct fan 46, a fan with more power consumption and a higher operating volume compared to the flow fan 44 and the exhaust fan 45 is used.

[0025] Specifically, one flow fan 44 is provided in the drying unit 4, its power consumption is 13.4W, and the sound pressure level is 40dB. Thirty-two exhaust fans 45 are provided in the drying unit 4, the total power consumption is 430.1W, and the sound pressure level is 55dB. One hundred and twenty-eight duct fans 46 are provided in the drying unit 4, the total power consumption is 1720W, and the sound pressure level is 61dB. Therefore, from the perspective of suppressing the power consumption and the operating volume of each of the fans 44, 45, 46, it is desirable to make the operating ratio of the flow fan 44 as high as possible and the operating ratio of the duct fan 46 as low as possible.

[0026] <Specific example of the operation of the drying unit 4> Hereinafter, a specific example of the operation of the drying unit 4 will be described. FIG. 5 is a schematic diagram showing a state in which all the fans 44, 45, and 46 provided in the drying unit 4 are stopped. FIG. 6 is a schematic diagram showing a state in which the flow fan 44 provided in the drying unit 4 is operating and the other fans 45 and 46 are stopped. FIG. 7 is a schematic diagram showing a state in which the flow fan 44 and the exhaust fan 45 provided in the drying unit 4 are operating and the duct fan 46 is stopped. FIG. 8 is a schematic diagram showing a state in which all the fans 44, 45, and 46 provided in the drying unit 4 are operating.

[0027] The drying process (the pre-treatment post-drying process S3 and the post-treatment post-drying process S6 in FIG. 4) is performed during the conveyance period of the continuous paper LP and is not performed during the period when the conveyance of the continuous paper LP is stopped. In the drying process, the control unit 9 periodically acquires the detection signal from the humidity sensor 43c and determines whether or not the detected humidity based on the detection signal exceeds the humidity threshold value. The humidity threshold value is determined to be, for example, the humidity at which condensation can occur inside the housing 41. As shown in FIG. 5, when the detected humidity does not exceed the humidity threshold value, the control unit 9 stops the flow fan 44, the exhaust fan 45, and the duct fan 46.

[0028] As shown in FIG. 6, when the detected humidity exceeds the humidity threshold value in the stopped state of the flow fan 44, the exhaust fan 45, and the duct fan 46, the control unit 9 operates only the flow fan 44. Since the operation of the flow fan 44 generates an air flow through the connection terminal 43a, the inconvenience of water droplets adhering to the connection terminal 43a due to condensation is suppressed. After starting the operation of the flow fan 44, the control unit 9 periodically acquires the detection signal from the humidity sensor 43c and determines whether or not the detected humidity based on the detection signal exceeds the humidity threshold value.

[0029] As shown in FIG. 7, when the detected humidity still exceeds the humidity threshold value after the elapse of a specified time (the first specified time) from the start of the operation of the flow fan 44, the control unit 9 operates the exhaust fan 45 in addition to the flow fan 44. The first specified time is determined as appropriate. Due to the operation of the exhaust fan 45, the air inside the housing 41 is discharged outside the housing 41 (into the room RM) through the exhaust opening 41a. Since the air inside the housing 41 contains moisture, discharging it outside the housing 41 can reduce the humidity inside the housing 41. Thereby, the occurrence of condensation inside the housing 41 can be suppressed. After starting the operation of the exhaust fan 45, the control unit 9 periodically acquires the detection signal from the humidity sensor 43c and determines whether the detected humidity based on the detection signal exceeds the humidity threshold value.

[0030] As shown in FIG. 8, when the detected humidity still exceeds the humidity threshold value even after the elapse of a specified time (the second specified time) from the start of the operation of the exhaust fan 45, the control unit 9 operates the duct fan 46 in addition to the flow fan 44 and the exhaust fan 45. The second specified time is determined as appropriate. Due to the operation of the duct fan 46, the air inside the housing 41 is also discharged outside the housing 41 (outside the room RM, for example, outside the building where the image forming apparatus 1 is installed) through the exhaust duct DC. That is, a part of the air inside the housing 41 is discharged into the room RM through the exhaust opening 41a, and another part is discharged outside the building through the exhaust duct DC. Note that the amount of air discharged is larger through the exhaust duct DC than through the exhaust opening 41a. Since the duct fan 46 and the exhaust fan 45 are operating to discharge the air inside the housing 41, the humidity inside the housing 41 can be quickly reduced.

[0031] After starting the operation of the duct fan 46, the control unit 9 periodically acquires the detection signal from the humidity sensor 43c and determines whether the detected humidity based on the detection signal exceeds the humidity threshold value. Then, the flow fan 44, the exhaust fan 45, and the duct fan 46 are operated until the detected humidity becomes equal to or lower than the humidity threshold value, and when the detected humidity becomes equal to or lower than the humidity threshold value, all the fans 44, 45, 46 are stopped. When all the fans 44, 45, 46 are stopped, it returns to the state of FIG. 5.

[0032] As described above, in the image forming apparatus 1 of the present embodiment, in the drying steps S3 and S6, the operating ratio of the flow fan 44 can be increased, and the operating ratio of the duct fan 46 can be decreased. Since the flow fan 44 has lower power consumption and a smaller operating volume than the exhaust fan 45 and the duct fan 46, by operating the flow fan 44 and stopping the other fans 45 and 46, it is possible to suppress the power consumption and the operating volume while suppressing the adhesion of water droplets to the connection terminal 43a. The exhaust fan 45 has lower power consumption and a smaller operating volume than the duct fan 46. Therefore, by operating the exhaust fan 45 and stopping the duct fan 46, it is possible to lower the humidity inside the housing 41 while suppressing the power consumption and the operating volume as compared with the case where the duct fan 46 is operated. Since the duct fan 46 has a higher exhaust capacity than the exhaust fan 45, the humidity inside the housing 41 can be quickly lowered. Further, since the exhaust duct DC exhausts air outside the building, an increase in the humidity of the room RM can be suppressed.

[0033] <Specific Example of Control> Next, the control by the control unit 9 in the drying steps S3 and S6 will be described. FIG. 9 is a flowchart for explaining the control by the control unit 9 in the drying step. Before the drying step is started, the control unit 9 energizes the heat roller 42c (built-in heater 42e) and adjusts the temperature of the outer peripheral surface of the heat roller 42c to a specified temperature. The drying step is started after the outer peripheral surface of the heat roller 42c is adjusted to the specified temperature. When the drying step is started, the control unit 9 acquires the detected humidity based on the detection signal from the humidity sensor 43c, and determines whether or not the detected temperature exceeds the humidity threshold value (S11). If the detected temperature exceeds the humidity threshold value (S11, Yes), the control unit 9 determines whether or not the flow fan 44 is operating (S12). If the flow fan 44 is not operating (S12, No), the control unit 9 operates the flow fan 44 (S13), and then proceeds to the process of step S22.

[0034] When the flow fan 44 is in operation (S12, Yes), the control unit 9 determines whether the operating time of the flow fan 44 exceeds a specified time (the first specified time) (S14). If the operating time of the flow fan 44 does not exceed the specified time (S14, No), the control unit 9 proceeds to the process of step S22. On the other hand, if the operating time of the flow fan 44 exceeds the specified time (S14, Yes), the control unit 9 determines whether the exhaust fan 45 is in operation (S15). If the exhaust fan 45 is not in operation (S15, No), the control unit 9 operates the exhaust fan 45 (S16), and then proceeds to the process of step S22.

[0035] If the exhaust fan 45 is in operation (S15, Yes), the control unit 9 determines whether the operating time of the exhaust fan 45 exceeds a specified time (the second specified time) (S17). If the operating time of the exhaust fan 45 does not exceed the specified time (S17, No), the control unit 9 proceeds to the process of step S22. On the other hand, if the operating time of the exhaust fan 45 exceeds the specified time (S17, Yes), the control unit 9 determines whether the duct fan 46 is in operation (S18). If the duct fan 46 is not in operation (S18, No), the control unit 9 operates the duct fan 46 (S19), and then proceeds to the process of step S22. On the other hand, if the duct fan 46 is in operation (S18, Yes), the control unit 9 proceeds to the process of step S22.

[0036] Also, when the detected temperature does not exceed the humidity threshold value (S11, No), the control unit 9 determines whether there is a fan in operation (S20). If there is no fan in operation (S20, No), the control unit 9 proceeds to the process of step S22. If there is a fan in operation (S20, Yes), the control unit 9 stops the fan in operation (S21), and then proceeds to the process of step S22. The control unit 9 determines whether or not the conveyance of the continuous paper LP has stopped in the process of step S22. If the conveyance has stopped (S22, Yes), the series of drying processes are terminated. If the conveyance has not stopped (S22, No), the process proceeds to step S11 and the above-described series of processes are repeated.

[0037] <Modification Example of the First Embodiment> As described with reference to FIG. 8, in the image forming apparatus 1 described above, when the detected humidity exceeded the humidity threshold even when the exhaust fan 45 was operated for a prescribed time, all of the flow fan 44, the exhaust fan 45, and the duct fan 46 were operated. Here, since the exhaust fan 45 discharges the air in the housing 41 into the room RM from the exhaust opening 41a, if the room RM is narrow and the humidity in the housing 41 is high, there is a possibility that the humidity in the room RM may increase.

[0038] FIG. 10 shows a modification example of the first embodiment, and is a schematic diagram showing a state in which the flow fan 44 and the duct fan 46 provided in the drying unit 4 are operating and the exhaust fan 45 is stopped. In the modification example shown in FIG. 10, when the detected humidity exceeds the humidity threshold even when the exhaust fan 45 is operated for a prescribed time (second prescribed time), the flow fan 44 and the duct fan 46 are operated and the exhaust fan 45 is stopped. By this control, when the duct fan 46 is operated, the amount of air discharged from the housing 41 into the room RM decreases, so that the inconvenience of the humidity in the room RM increasing is suppressed.

[0039] <Specific Example of Control> FIG. 11 is a flowchart for explaining the control of the control unit 9 in the modification example, that is, other control of the control unit 9 in the drying steps S3 and S6. Hereinafter, the control of the control unit 9 will be described with reference to the flowchart of FIG. 11. Regarding the control of the modification example, the description of the same processes as the above-described control will be omitted as appropriate. The control unit 9 determines whether the detected temperature exceeds the humidity threshold (S31). If the detected temperature exceeds the humidity threshold (S31, Yes), it determines whether the flow fan 44 is operating (S32). If it is not operating (S32, No), it operates the flow fan 44 (S33).

[0040] When the flow fan 44 is operating (S32, Yes), the control unit 9 determines whether the operating time of the flow fan 44 exceeds the specified time (the first specified time) (S34). If it exceeds the specified time (S34, Yes), it determines whether the exhaust fan 45 is operating (S35). When the exhaust fan 45 is not operating (S35, No), the control unit 9 determines whether the duct fan 46 is operating (S36). If it is not operating (S36, No), it operates the exhaust fan 45 (S37). That is, in the modified example, if the duct fan 46 is operating (S36, Yes), the exhaust fan 45 is not operated, which is different from the above control. When the exhaust fan 45 is operating (S35, Yes), the control unit 9 determines whether the operating time of the exhaust fan 45 exceeds the specified time (the second specified time) (S38). If it exceeds the specified time (S38, Yes), it stops the exhaust fan 45 (S39) and operates the duct fan 46 (S40).

[0041] When the detected temperature does not exceed the humidity threshold (S31, No), the control unit 9 determines whether there is an operating fan (S41). If there is an operating fan (S41, Yes), it stops the operating fan (S42). The control unit 9 determines whether the conveyance of the continuous paper LP has stopped in step S43. If the conveyance has stopped (S43, Yes), it ends the series of drying processes. If the conveyance has not stopped (S43, No), it proceeds to the process of step S31 and repeats the above-described series of processes.

[0042] <Second Embodiment> In the above-described first embodiment, one electrical component unit 43 was provided in the drying unit 4 (the pre-treatment drying unit 4F and the post-treatment drying unit 4R), but a plurality of electrical component units 43 may be provided. FIG. 12 is a schematic diagram showing the configuration of the second embodiment. The drying unit 4' shown in FIG. 12 is characterized in that it includes a first electrical component unit 43A and a second electrical component unit 43B. Since the other configurations are the same as those described with reference to FIG. 1, the description thereof will be omitted.

[0043] The first electrical component unit 43A and the second electrical component unit 43B have the same configuration, and include a terminal block 43b provided with a plurality of connection terminals 43a, a humidity sensor 43c for detecting the humidity inside the housing 41, and a flow fan 44 for flowing the air inside the housing 41 so that a flow of air passes through the connection terminals 43a. That is, the drying unit 4' of the image forming apparatus 1 according to the second embodiment includes a plurality of terminal blocks 43b each having a plurality of connection terminals 43a. The flow fans 44 and the humidity sensors 43c are provided in plurality corresponding to each of the plurality of terminal blocks 43b, and wiring PL for the heat roller 42c routed from outside the housing 41 is connected to the plurality of connection terminals 43a provided in each terminal block 43b. Detection signals from the humidity sensors 43c included in the first electrical component unit 43A and detection signals from the humidity sensors 43c included in the second electrical component unit 43B are input to the control unit 9, and each flow fan 44 is controlled based on the respective detection signals (detected humidity). Even in the second embodiment having the above configuration, the same operational effects as those of the first embodiment are achieved.

[0044] <Third Embodiment> In the above-described first embodiment, the exhaust ducts DC are individually connected to the pre-treatment drying unit 4F and the post-treatment drying unit 4R, and the duct fans 46 are provided at the connection openings 41b of the housings 41 included in the respective drying units 4F and 4R, but the present invention is not limited to this configuration. FIG. 13 is a schematic diagram showing the configuration of the third embodiment in which the duct fan 46 is provided in the common exhaust duct DC-C. For the parts described in the first embodiment, the same reference numerals are given and the description thereof is omitted. The image forming apparatus 1A shown in FIG. 13 corresponds to the drying system according to the present invention. The downstream end of an exhaust duct DC-F (first exhaust duct) whose upstream end is connected to the connection opening 41b of a pre-treatment drying unit 4F (first drying device) and the downstream end of an exhaust duct DC-R (second exhaust duct) whose upstream end is connected to the connection opening 41b of a post-treatment drying unit 4R (second drying device) are communicated with the upstream end of a common exhaust duct DC-C. And a duct fan 46 is provided in the common exhaust duct DC-C.

[0045] In the image forming apparatus 1A of the third embodiment, since the duct fan 46 is provided in the common exhaust duct DC-C, the number of duct fans 46 can be made smaller as compared with the image forming apparatus 1 of the first embodiment, and the configuration can be simplified. Furthermore, when the duct fan 46 is operated when the detected humidity in the housing 41 exceeds the humidity threshold value for either the pre-treatment drying unit 4F or the post-treatment drying unit 4R, the air in the housing 41 is also discharged for the other of the pre-treatment drying unit 4F and the post-treatment drying unit 4R, so that the humidity in the housing 41 can be lowered.

[0046] <Fourth Embodiment> In the third embodiment described above, the image forming apparatus 1A in which the exhaust duct DC-F of the pre-treatment drying unit 4F and the exhaust duct DC-R of the post-treatment drying unit 4R are connected to the common exhaust duct DC-C and the duct fan 46 is provided in the common exhaust duct DC-C is illustrated, but the present invention is not limited to this configuration. FIG. 14 is a schematic diagram showing the configuration of a fourth embodiment in which a duct fan 46 is provided in a third common exhaust duct DC-C. Note that the parts described in the first embodiment are denoted by the same reference numerals and the description thereof is omitted. The image forming system 100 shown in FIG. 14 includes a first image forming apparatus 1A installed in a first room RM1 and a second image forming apparatus 1A' installed in a second room RM2.

[0047] In the illustrated image forming system 100, the downstream ends of the exhaust ducts DC-F1 of the pre-processing drying unit 4F and the exhaust ducts DC-R1 of the post-processing drying unit 4R provided in the first image forming apparatus 1A are connected to the upstream end of the first common exhaust duct DC-C1, and the downstream ends of the exhaust ducts DC-F2 of the pre-processing drying unit 4F and the exhaust ducts DC-R2 of the post-processing drying unit 4R provided in the second image forming apparatus 1A' are connected to the upstream end of the second common exhaust duct DC-C2. Furthermore, the downstream end of the first common exhaust duct DC-C1 and the downstream end of the second common exhaust duct DC-C2 are connected to the upstream end of the third common exhaust duct DC-C3, and a duct fan 46 is provided in the third common exhaust duct DC-C3. The duct fan 46 is controlled by the control units 9 provided in the first image forming apparatus 1A and the second image forming apparatus 1A' respectively.

[0048] In the image forming system 100 of the fourth embodiment, since the duct fan 46 is provided in the third common exhaust duct DC-C3, the configuration can be simplified as compared with a configuration in which a duct fan 46 is provided at each of the connection openings 41b of the four drying units 4 (the pre-processing drying unit 4F and the post-processing drying unit 4R provided in the first image forming apparatus 1A, and the pre-processing drying unit 4F and the post-processing drying unit 4R provided in the second image forming apparatus 1A'). Furthermore, when the duct fan 46 is operated when the detected humidity in the housing 41 exceeds the humidity threshold for any one of the four drying units 4, the air in the housing 41 can be discharged for the remaining three drying units 4 as well to reduce the humidity.

[0049] <Other Modification Examples> In each of the foregoing embodiments, when the detected humidity exceeds the humidity threshold in the stopped state of the three types of fans (the flow fan 44, the exhaust fan 45, and the duct fan 46), only the flow fan 44 is operated. If the detected humidity still exceeds the humidity threshold even when the flow fan 44 is operated for a first specified time, the exhaust fan 45 is operated. If the detected humidity still exceeds the humidity threshold even when the exhaust fan 45 is operated for a second specified time, the duct fan 46 is operated. However, the present invention is not limited to this configuration. For example, any configuration may be used as long as it controls the operations (operation and stop) of the flow fan 44, the exhaust fan 45, and the duct fan 46 according to the detected humidity.

[0050] In each of the foregoing embodiments, the drying device according to the present invention is included in the image forming apparatuses 1, 1A, and 1A'. However, the present invention is not limited to this configuration. For example, the drying device may be separated from the image forming apparatuses 1, 1A, and 1A' and configured to be independently operable. FIG. 15 is a block diagram showing the configuration of an independently operable drying device 200. The drying device 200 shown in FIG. 15 is characterized in that a control unit 9 (CPU 9a, memory 9b, I / F 9c) shown in FIG. 15 is provided for the drying unit 4 described in FIG. 2. The drying device 200 can operate in cooperation with the image forming apparatus 1 or independently of the image forming apparatus 1.

[0051] In each of the foregoing embodiments, the image forming apparatuses 1, 1A, and 1A' provided with both the pre-processing drying unit 4F and the post-processing drying unit 4R are exemplified. However, the present invention can also be applied to an image forming apparatus provided with only one of the pre-processing drying unit 4F and the post-processing drying unit 4R. In each of the foregoing embodiments, the inkjet type image forming apparatuses 1, 1A, and 1A' are exemplified. However, the present invention is not limited thereto. For example, the present invention can also be applied to an image forming apparatus of another image forming method such as an electrophotographic method. Regarding the control unit 9, part or all of the control unit 9 may be configured by hardware logic. Regarding the humidity sensor 43c, as long as it can detect the humidity inside the housing 41, it may be provided at a location other than the electrical component unit 43. Regarding the plurality of connection terminals 43a, although an example where the wiring PL for the heat roller 42c is connected has been illustrated, those for connecting wiring for other applications may also be used.

[0052] In each of the above-described embodiments, the image forming apparatuses 1, 1A, 1A' for forming an image on the continuous paper LP (recording medium) have been illustrated, but the present invention is not limited thereto. For example, the present invention can also be applied to an image forming apparatus for forming an image on a sheet of paper (recording medium). The recording medium may be any medium that holds a liquid (e.g., various solvents including water) and releases the held liquid when heated from the outside. For example, the recording medium may be a postcard, an envelope, a coated paper (such as coated paper or art paper), or tracing paper, or an OHP sheet, an OHP film, or a prepreg.

[0053] [Summary of Embodiment Examples, Operations, and Effects of the Present Invention] <First Embodiment> The drying apparatus (a combination of the drying units 4, 4' and the control unit 9, drying apparatus 200) according to this embodiment includes a housing 41 provided with an exhaust opening 41a and a connection opening 41b, a transport mechanism 42b housed in the housing 41 for transporting the continuous paper LP (recording medium) along the transport path CR, a heat roller 42c (heater) housed in the housing 41 for heating the continuous paper LP on the transport path CR, a connection terminal 43a for connecting the wiring PL routed from outside the housing 41 inside the housing 41, a humidity sensor 43c (humidity detection means) for detecting the humidity inside the housing 41, a flow fan 44 for flowing the air inside the housing 41 so that a flow of air passes through the connection terminal 43a, an exhaust fan 45 for discharging the air inside the housing 41 to the outside of the housing 41 through the exhaust opening 41a, a duct fan 46 for discharging the air inside the housing 41 through an exhaust duct DC connected to the connection opening 41b, and a control unit 9 (control means) for controlling the operations of the flow fan 44, the exhaust fan 45, and the duct fan 46 based on the detected humidity of the humidity sensor 43c.

[0054] According to the drying device according to this aspect, since the control unit 9 controls the operations of the flow fan 44, the exhaust fan 45, and the duct fan 46 based on the detected humidity of the humidity sensor 43c, it is possible to generate an air flow passing through the connection terminal 43a in the housing 41, or to select the discharge destination of the air in the housing 41 between outside the housing 41 and the exhaust duct DC. As a result, the humidity in the housing 41 can be appropriately managed.

[0055] <Second Embodiment> In the drying device (the combination of the drying units 4, 4' and the control unit 9, drying device 200) according to this aspect, the humidity sensor 43c is provided in the electrical component unit 43 so as to detect the humidity near the connection terminal 43a. When the detected humidity exceeds the humidity threshold value in the stopped state of the flow fan 44, the exhaust fan 45, and the duct fan 46, the control unit 9 operates only the flow fan 44. When the detected humidity still exceeds the humidity threshold value even after operating the flow fan 44 for a first specified time, the exhaust fan 45 is operated. When the detected humidity still exceeds the humidity threshold value even after operating the exhaust fan 45 for a second specified time, the duct fan 46 is operated.

[0056] According to the drying device according to this aspect, since the control unit 9 operates the flow fan 44, the exhaust fan 45, and the duct fan 46 step by step in this order based on the detected humidity of the humidity sensor 43c, the operating ratio of the flow fan 44 can be increased and the operating ratio of the duct fan 46 can be decreased. As a result, the power consumption and the operating noise can be suppressed.

[0057] <Third Embodiment> In the drying device (the combination of the drying units 4, 4' and the control unit 9, drying device 200) according to this aspect, when the detected humidity still exceeds the humidity threshold value even after operating the exhaust fan 45 for a second specified time, the control unit 9 stops the exhaust fan 45 and operates the duct fan 46. According to the drying device according to this aspect, since the exhaust fan 45 is stopped while the duct fan 46 is operating, it is possible to suppress the inconvenience that the humidity in the room RM increases.

[0058] <Fourth Embodiment> In the drying device (a combination of the drying unit 4' and the control unit 9, drying device 200) according to this aspect, a plurality of terminal blocks 43b having a plurality of connection terminals 43a are provided, and a plurality of fluid fans 44 and humidity sensors 43c are provided in plurality corresponding to each of the plurality of terminal blocks 43b, and the control unit 9 controls the plurality of fluid fans 44 based on detection signals from the plurality of humidity sensors 43c. According to the drying device according to this aspect, the humidity inside the housing 41 can be appropriately managed.

[0059] <Fifth Embodiment> This aspect is a drying system (image forming apparatus 1A) including a first drying device (a combination of a pre-treatment drying unit 4F and a control unit 9) and a second drying device (a combination of a post-treatment drying unit 4R and a control unit 9), wherein the combination of the pre-treatment drying unit 4F and the control unit 9, and the combination of the post-treatment drying unit 4R and the control unit 9 are configured as described in the above respective aspects, and the downstream end of an exhaust duct DC-F (first exhaust duct) whose upstream end is connected to the connection opening 41b of the pre-treatment drying unit 4F, and the downstream end of an exhaust duct DC-R (second exhaust duct) whose upstream end is connected to the connection opening 41b of the post-treatment drying unit 4R (second drying device) are respectively communicated with the upstream end of a common exhaust duct DC-C, and a duct fan 46 is provided in the common exhaust duct DC-C. According to the drying system according to this aspect, the number of duct fans 46 can be reduced, so that the configuration can be simplified. Further, when the duct fan 46 is operated when the detected humidity inside the housing 41 exceeds the humidity threshold value for one of the pre-treatment drying unit 4F and the post-treatment drying unit 4R, accordingly, the air inside the housing 41 can also be discharged for the other of the pre-treatment drying unit 4F and the post-treatment drying unit 4R to reduce the humidity.

[0060] <Sixth Embodiment> The image forming apparatus (image forming apparatuses 1 and 1A) according to this aspect is characterized by including an image forming unit 6 that forms an image on continuous paper LP (recording medium), and a set of a drying unit 4, 4' and a control unit 9 (drying device) of each of the above-described aspects. According to the image forming apparatus of this aspect, the humidity inside the housing 41 can be appropriately managed.

Explanation of Signs

[0061] 1, 1A, 1A’... image forming apparatus; 2... loading unit, 2a... feeding unit; 2b... guide roller; 2c... feeding motor; 3... pretreatment unit; 31... storage container; 32... thinning roller; 33... coating roller; 34... platen roller; 4, 4’... drying unit; 4F... pretreatment drying unit; 4R... post-treatment drying unit; 41... housing; 41a... exhaust opening; 41b... connection opening; 42... heating unit; 42a... guide roller; 42b... conveying mechanism; 42c... heat roller; 42d... cylindrical member; 42e... built-in heater; 43... electrical component unit; 43A... first electrical component unit; 43B... second electrical component unit; 43a... connection terminal; 43b... terminal block; 43c... humidity sensor; 44... flow fan; 45... exhaust fan; 46... duct fan; 5... guiding unit; 51... guide roller; 6... image forming unit; 6K... head for black ink; 6C... head for cyan ink; 6M... head for magenta ink; 6Y... head for yellow ink; 7... post-treatment unit; 71... post-treatment head; 8... unloading unit; 8a... guide roller; 8b... winding unit; 8c... winding motor; 9... control unit; 9a... CPU; 9b... memory; 9c... I / F; 100... image forming system; 200... drying device; LP... continuous paper; CR... conveying path; DC, DC-F, DC-F1, DC-F2, DC-R, DC-R1, DC-R2... exhaust duct, DC-C, DC-C1, DC-C2, DC-C3... common exhaust duct, PS... pretreatment liquid

Prior Art Documents

Patent Documents

[0062]

Patent Document 1

Claims

1. A housing provided with an exhaust opening and a connection opening, a transport mechanism accommodated in the housing for transporting a recording medium along a transport path, a heater accommodated in the housing for heating the recording medium on the transport path, a connection terminal for connecting wiring routed from outside the housing inside the housing, humidity detection means for detecting the humidity inside the housing, a flow fan for flowing air inside the housing so that a flow of air passing through the connection terminal occurs, an exhaust fan for discharging air inside the housing to the outside of the housing through the exhaust opening, a duct fan for discharging air inside the housing through an exhaust duct connected to the connection opening, a drying device comprising control means for controlling the operations of the flow fan, the exhaust fan, and the duct fan based on the detected humidity of the humidity detection means.

2. The humidity detection means is configured to detect the humidity near the connection terminal, The control means, when the detected humidity exceeds a threshold value in a stopped state of the flow fan, the exhaust fan, and the duct fan, operates only the flow fan, when the detected humidity still exceeds the threshold value even after operating the flow fan for a first specified time, operates the exhaust fan, The drying device according to claim 1, wherein when the detected humidity still exceeds the threshold value even after operating the exhaust fan for a second specified time, the duct fan is operated.

3. The drying device according to claim 2, wherein the control means stops the exhaust fan and operates the duct fan when the detected humidity still exceeds the threshold value even after operating the exhaust fan for the second specified time.

4. A plurality of terminal blocks having a plurality of the connection terminals are provided, a plurality of the flow fans and the humidity detection means are provided corresponding to each of the plurality of the terminal blocks, The drying device according to claim 1, wherein the control means controls the plurality of the flow fans based on detection signals from the plurality of the humidity detection means.

5. A drying system comprising a first drying device and a second drying device, each of the first drying device and the second drying device is constituted by the drying device according to any one of claims 1 to 4, The downstream end of a first exhaust duct having an upstream end connected to the connection opening of the first drying device, and the downstream end of a second exhaust duct having an upstream end connected to the connection opening of the second drying device are each communicated with the upstream end of a common exhaust duct. A drying system characterized in that the duct fan is provided in the common exhaust duct. **Claim 6** An image forming apparatus comprising: an image forming unit that forms an image on a recording medium; and the drying device according to any one of claims 1 to 4.

Images