Image forming apparatus and drying device

An image forming apparatus includes a drying section, a cooling section, and an exhaust section. The drying section dries a recording medium on which an image is formed. The cooling section cools the recording medium dried by the drying section. The exhaust section exhausts air from the drying section and the cooling section through an exhaust port. The exhaust section includes a plurality of flow path determiners disposed on opposing walls of the exhaust section, to form an air flow path from the drying section to the exhaust port. The plurality of flow path determiners alternately projects from the opposing walls.

CROSS-REFERENCE TO RELATED APPLICATION

This patent application is based on and claims priority pursuant to 35 U.S.C. §119(a) to Japanese Patent Application No. 2015-122020, filed on Jun. 17, 2015 in the Japan Patent Office, the entire disclosure of which is hereby incorporated by reference herein.

BACKGROUND

Technical Field

Aspects of the present disclosure relate to an image forming apparatus and a drying device.

Related Art

The temperature inside an image forming apparatus, such as a copier, a multifunction peripheral, a printer, and a facsimile machine, is controlled to be kept high for drying ink used for printing and a print sheet used for printing. From a viewpoint of management of the temperature relating to maintenance of performance in the printing process and prevention of melting of parts, for example, heat is exhausted to the outside of the image forming apparatus after completion of print output of a sheet to rapidly cool the inside of the image forming apparatus.

Moisture contained in a sheet and ink evaporates under high temperature during a print output. Therefore, if moisture in the vapor inside the image forming apparatus condenses by cooling, there is a concern of causing a short in an electric circuit or degrading printing quality.

SUMMARY

In an aspect of the present disclosure, there is provided an image forming apparatus that includes a drying section, a cooling section, and an exhaust section. The drying section dries a recording medium on which an image is formed. The cooling section cools the recording medium dried by the drying section. The exhaust section exhausts air from the drying section and the cooling section through an exhaust port. The exhaust section includes a plurality of flow path determiners disposed on opposing walls of the exhaust section, to form an air flow path from the drying section to the exhaust port. The plurality of flow path determiners alternately projects from the opposing walls.

In an aspect of the present disclosure, there is provided a drying device that includes a drying section, a cooling section, and an exhaust section. The drying section dries a recording medium on which an image is formed. The cooling section cools the recording medium dried by the drying section. The exhaust section exhausts air from the drying section and the cooling section through an exhaust port. The exhaust section includes a plurality of flow path determiners disposed on opposing walls of the exhaust section, to form an air flow path from the drying section to the exhaust port. The plurality of flow path determiners alternately projects from the opposing walls.

DETAILED DESCRIPTION

Hereinafter, embodiments of the present disclosure are described with reference to the drawings. A configuration of an image forming apparatus according to the present disclosure will now be described based on an image forming apparatus1illustrated inFIG. 1andFIG. 6.FIG. 1is a side view of the configuration of the image forming apparatus1viewed in a sub-scanning direction indicated by arrow SSD.FIG. 6is a sectional view of the image forming apparatus1taken along a broken line A-A inFIG. 1.

The image forming apparatus1illustrated inFIG. 1includes a print unit2, a drying section3, an opening4, a cooling section5, and a liquid collection unit6.

The print unit2discharges liquid droplets, such as ink droplets, from a print nozzle onto a recording medium P to perform printing. The ink discharged from the print nozzle but is not used for printing is introduced to the liquid collection unit6to be collected separately from the recording medium P.

The drying section3includes heating rollers31and conveyance rollers32. Each heating roller31includes a heater33inside and heats the recording medium P to fix the ink which has been discharged onto the recording medium P by drying. The drying section3thus acts as a sheet drying device. The heating method of the heater33in each heating roller31may be any suitable method. In this embodiment, for example, as illustrated inFIG. 1, the temperatures of the heaters33are measured by temperature detecting elements34, such as resistance temperature detectors or thermocouples, and controlled to a setting temperature by a temperature controller35. The conveyance rollers32are arranged to convey the recording medium P to a cooling section5via the heating rollers31. The conveyance rollers32include a drive roller that is driven by a drive source and driven rollers, e.g., idler rollers driven by the conveyed recording medium P. In some embodiments, the conveyance roller32may include, for example, the temperature detecting element34to detect the temperature in the drying section3.

In some embodiments, as illustrated inFIG. 2, an image forming apparatus1may include a sheet drying device130including the drying section3separately from a printing device120including the print unit2.

The opening4is provided to take air into the drying section3from the outside of the image forming apparatus1. When a front panel13, which will be described later, is closed, the inside of the image forming apparatus1cannot be viewed from outside.

The cooling section5cools the recording medium P conveyed from the drying section3and includes an internal fan and a conveyance roller. The internal fan is driven to cool the surface of the recording medium P. Similar to the conveyance rollers32in the drying section3, the conveyance rollers of the cooling section5include a rotation roller (drive roller) and idler rollers. The recording medium P cooled in the cooling section5is conveyed by the conveyance roller to the outside of the image forming apparatus1.

The liquid collection unit6is provided vertically below the fin9. The ink that is not used for printing and a liquid component in the image forming apparatus1are introduced to and collected in the liquid collection unit6and temporarily stored. The collected liquid component is discarded as required.

As illustrated inFIG. 6, the image forming apparatus1includes an exhaust duct7, an exhaust device8, fins9, a fan10, a drying-section partition11, and a cooling-section partition12.

The exhaust duct7is a path to exhaust air outside from the image forming apparatus1, and is disposed downstream from the drying section3in the path through which air in the image forming apparatus1is exhausted outside. Therefore, the exhaust duct7corresponds to an exhaust section in the image forming apparatus1. The cooling-section partition12separates the exhaust duct7from the cooling section5. By moving the cooling-section partition12, exhaust air in the cooling section5can be ejected through the exhaust duct7. Internal surfaces of the exhaust duct7other than where the fins9, which will be described later, are provided are waterproofed, and therefore do not catch water and solvent contained in exhaust air.

The exhaust device8suctions exhaust air from the exhaust duct7and exhausts the air to the outside of the image forming apparatus1. The exhaust device8is provided most downstream in the path along which exhaust air is transferred to eject the exhaust air to the outside of the image forming apparatus1. Therefore, the exhaust device8corresponds to an exhaust port of the image forming apparatus1.

A plurality of fins9each made of a steel plate or an aluminum plate is provided on opposing internal walls of the exhaust duct7to project alternately toward the opposing wall. The fins9are cooled by the cool air from the outside of the image forming apparatus1and a fan10, which will be described later. The angle of the plate surface of the fin9to the internal wall of the exhaust duct7is controlled by, for example, a solenoid or a motor, to change the projection height of the fin9from the internal wall of the exhaust duct7. The flow path of air in the exhaust duct7changes with the change in the projection height of the fin9, which means that the fin9acts as a flow path determiner.

The fan10is provided behind the fin9and outside the exhaust duct7to reduce the temperature around the fin9.

The drying-section partition11is provided to take in air from the outside of the image forming apparatus1through the opening4, and is movable to close the opening4. By closing the opening4with the drying-section partition11, the inside of the drying section3can be sealed to prevent a temperature drop in the drying section3during drying of the recording medium P.

The cooling-section partition12is provided to control the inflow of air from the cooling section5into the exhaust duct7, and is movable to separate or adjoin the cooling section5and the exhaust duct7. By using the cooling-section partition12, the inflow of air from the cooling section5into the exhaust duct7can be closed.

The image forming apparatus1according to the embodiment includes the front panel13as illustrated inFIG. 12. The front panel13is provided to cover the drying section3and the cooling section5. When the front panel13is closed, the inflow of air from the outside through the opening4is reduced. When the front panel13is opened, air can be taken from the outside into the drying section3through the opening4. The front panel13is opened, for example, for maintenance of the image forming apparatus1.

A configuration of hardware of the image forming apparatus1will be described below referring toFIG. 3.FIG. 3is a block diagram of a hardware configuration of the image forming apparatus1according to the present embodiment.

As illustrated inFIG. 3, the image forming apparatus1according to the present embodiment is similar in configuration to an information processing terminal, such as a general server or a personal computer (PC). That is, in the image forming apparatus1according to the present embodiment, a central processing unit (CPU)201, a random access memory (RAM)202, a read only memory (ROM)203, a hard disk drive (HDD)204, and an interface (I/F205are connected to each other via a bus209. The I/F205is connected with a liquid crystal display (LCD)206and an operation unit207. Signals are transmitted and received to/from an external device208connected to the image forming apparatus1via the I/F205.

The CPU201is an arithmetic unit and controls the operation of the entire image forming apparatus1. The RAM202is a volatile storage medium capable of reading and writing information at a high speed and is used as a working area during information processing of the CPU201. The ROM203is a read-only non-volatile storage medium and stores a program, such as firmware. The HDD204is a non-volatile storage medium capable of reading and writing information and stores operating system (OS), various control programs, application programs, for example.

The I/F205connects the bus209with various types of hardware and networks and performs control. The LCD206is a visual user interface for a user confirming the state of the image forming apparatus1. The operation unit207is a user interface, such as a keyboard or a mouse, for the user inputting information to the image forming apparatus1. The external device208is hardware for realizing a specific function of the image forming apparatus1, and is, for example, a print engine for executing an image forming operation on the recording medium.

In such a hardware configuration, the programs stored in the ROM203and the HDD204or a storage medium, such as an optical disk, are read by the RAM202, and an arithmetic operation is performed according to the programs loaded in RAM202by the CPU201to configure a software controller. The software controller configured in this way is combined with the hardware to configure a functional block for realizing functions of the image forming apparatus1according to the present embodiment.

Next, referring to a functional block diagram of the image forming apparatus1according to the present embodiment illustrated inFIG. 4, a functional configuration of the image forming apparatus1will be described. As illustrated inFIG. 4, the image forming apparatus1includes a controller300, a display panel301, a sheet feed device302, a print engine303, a sheet ejection device304, and an external-device connector interface (I/F)305.

The controller300includes a main controller310, an engine controller320, an image processor330, an operation display controller340, and an input-output controller350. InFIG. 4, electrical connections are indicated by solid arrows, and a flow of sheet of paper is indicated by a broken line.

The controller300is configured by a combination of software and hardware. For example, the controller300is constituted by the software controller constructed by computation of the CPU201as described above and hardware, such as integrated circuits. The controller300functions as a controller that controls the entire image forming apparatus1.

The main controller310plays a role of controlling each unit included in the controller300and gives commands to each unit of the controller300. The engine controller320serves as a driver that controls and drives the print engine303.

The input-output controller350inputs signals and commands input through the external-device connector interface (I/F)305to the main controller310. The main controller310controls the input-output controller350and accesses other devices through the external-device connector interface (I/F)350.

The image processor330generates drawing information based on print information included in a print job to be input according to the control of the main controller310. The drawing information is information that the print engine303as an image forming unit draws as an image to be formed in an image forming operation. The print information included in the print job is image information that is converted into a format recognizable by the image forming apparatus1by a printer driver installed in an information processing device, such as a PC. The operation display controller340displays information on the display panel301or notifies information input through the display panel301to the main controller310.

In the image forming apparatus1, first, the input-output controller350receives a print job through the external-device connector interface (I/F)305. The input-output controller350transfers the received print job to the main controller310. When receiving the print job, the main controller310controls the image processor330to generate drawing information based on print information included in the print job.

When the drawing information is generated by the image processor330, the engine controller320executes an image forming operation on the sheet fed from the sheet feed device302, based on the generated drawing information. That is, the print engine303functions as an image forming unit. A document subjected to the image forming operation by the print engine303is ejected to the outside of the apparatus by the sheet ejection device304.

In the image forming apparatus1, the printing unit2corresponding to the print engine303performs the image forming operation on the recording medium P fed in a sheet feed direction (indicated by arrow D1inFIG. 1) from the sheet feed device302, a drying section3, and a cooling section5. The recording medium P is discharged by the sheet ejection device304to the outside of the image forming apparatus1.

As described above, the image forming apparatus1controls the temperature in the drying section3to be kept high during image forming to dry ink adhering to the recording medium P. Meanwhile, from a viewpoint of management of the temperature relating to maintenance of performance in the printing process and prevention of melting of parts, the inside of the image forming apparatus1need to be cooled rapidly after completion of a print output. In such a case, if the exhaust air containing moisture evaporated from ink and the recording medium P under high temperature is rapidly cooled, the moisture may condense and remain in the image forming apparatus1to cause effects. To prevent remaining of condensed moisture, the exhaust air may be ejected to the outside of the apparatus through, for example, a moisture-absorption filter. Such a configuration however may fail to maintain the performance under the increased exhaust air volume during continuous printing, for example, and cause deterioration in the cooling efficiency of the image forming apparatus1.

The present disclosure is directed to efficiently performing cooling and drying by switching modes in the image forming apparatus1between a mode that prioritizes exhaustion of a large amount of air and a mode that prioritizes dehumidification inside the apparatus.

A functional structure of components inside the exhaust duct7according to the embodiment will now be described with reference to a control block diagram of the components inside the exhaust duct7illustrated inFIG. 5. As illustrated inFIG. 5, the engine controller320performs a drive control of components in the exhaust duct7with reference to the information for controlling the operation of the image forming apparatus1acquired from the main controller310.

A print output information unit321is included in the engine controller320and outputs to the duct controller323the information indicating that a print engine303is performing a print output.

A temperature detector322is included in the engine controller320and outputs to the duct controller323the information on temperatures detected by temperature detecting elements in the heating roller31and the drying section3.

A duct controller323is included in the engine controller320and outputs information for controlling components inside the exhaust duct7based on the information received by the duct controller323. These components are the fin9, the fan10, the drying-section partition11, and the cooling-section partition12. An aspect of the control will be described later.

A fin position controller324is included in the engine controller320and controls the fin9based on the control information transmitted from the duct controller323.

A fan drive controller325is included in the engine controller320and controls the fan10based on the control information transmitted from the duct controller323.

A partition position controller326is included in the engine controller320and controls the drying-section partition11and the cooling-section partition12based on the control information transmitted from the duct controller323.

A panel opening-closing detector311is included in the main controller310and detects whether the front panel13of the image forming apparatus1is opened or closed. The panel opening-closing detector311outputs the information indicating the detected result to the duct controller323.

FIGS. 6 to 8illustrate an example of the duct controller323controlling the components inside the exhaust duct7. The control of components inside the exhaust duct7and the object of the control will be described below with reference to the drawings.FIGS. 6 to 8are sectional views of the image forming apparatus1taken along the broken line A inFIG. 1.

FIG. 6is an illustration of a configuration of the exhaust duct7when an image is formed and output in the image forming apparatus1. During image formation and output, the moisture in ink and the recording medium P evaporates by the heat from the heating roller31, and humidity inside the image forming apparatus1rises. The object of the control illustrated inFIG. 6is to rapidly cool the exhaust air containing a large amount of moisture so that the moisture condenses into water and then the water is introduced to and collected in the liquid collection unit6.

When image formation and output are not performed as illustrated inFIG. 6, the duct controller323positions the fins9to project vertical to the wall of the exhaust duct7and moves the cooling-section partition12so that the exhaust air in the exhaust duct7mixes with the air in the cooling section5. Furthermore, the duct controller323moves the drying-section partition11to close the opening4, and thereby dropping of the internal temperature in the drying section3is prevented to promote drying of the recording medium P.

By controlling the components inside the exhaust duct7to increase the flow path length of exhaust air, the exhaust air containing a large amount of moisture is cooled by the fins9to condense into water and to be introduced to the liquid collection unit6. The ejection of the air, of which temperature has risen by cooling the recording medium P, in the cooling section5is promoted.

FIG. 7is an illustration of a configuration of the exhaust duct7after completion of image formation and output in the image forming apparatus1. After completion of image formation and output cooling of the image forming apparatus1is desirably prioritized from a viewpoint of preventing melting of parts and maintaining printing quality of the image forming apparatus1. The object of the control illustrated inFIG. 7is to switch modes to increase the amount of exhaust flow in the exhaust duct7to prioritize the cooling of the image forming apparatus1.

After completion of image formation and output of an image, the duct controller323positions the fins9to be parallel to the exhaust duct7as illustrated inFIG. 7. The duct controller323also moves the cooling-section partition12to prevent the exhaust air in the cooling section5from flowing into the exhaust duct7.

To prioritize cooling of the image forming apparatus1, the components inside the exhaust duct7are controlled to increase the amount of exhaust flow in the exhaust duct7. In the control illustrated inFIG. 7, the drying-section partition11is controlled to prevent the air in the outside of the image forming apparatus1from flowing in through the opening4. By operating the exhaust device8under such a control, the moisturized exhaust air in the drying section3can efficiently be suctioned into the exhaust duct7.

FIG. 8is an illustration of a configuration of the exhaust duct7when image formation and output are not performed in the image forming apparatus1. After completion of a print output, the drying section3need to be cooled rapidly. The object of the control illustrated inFIG. 8is to increase the inflow of exhaust air through the drying section3to promote cooling of the drying section3.

When image formation and output are not performed, the duct controller323positions the fins9to be parallel to the exhaust duct7as illustrated inFIG. 8. By this configuration, there is no obstacle in the exhaust path in the exhaust duct7, and the amount of exhaust flow from the drying section3can be increased. The duct controller323also moves the drying-section partition11to open the opening4, so that the air in the outside of the image forming apparatus1flows into the drying section3to further promote cooling of the image forming apparatus1.

By controlling the components inside the exhaust duct7, the amount of exhaust flow ejected to the outside of the image forming apparatus1through the drying section3can be increased to further promote the cooling of the image forming apparatus1.

FIGS. 9 and 10are illustrations explaining the fin position controller324controlling the positions of the fins9. The control of the positions of the fins9and an effect by the control will now be described.

FIG. 9is an illustration of the exhaust path where the fins9are placed to project vertical to the exhaust duct7by the fin position controller324. As described in the control of the components inside the exhaust duct7, the fins9projecting vertical to the exhaust duct7increase the length of the air flow path, which promotes cooling of exhaust air. The vertically placed fins9thus efficiently cool the exhaust air to condense moisture into water, which can be collected in the liquid collection unit6.

FIG. 10is an illustration of the exhaust air flow path where the fins9are placed parallel to the exhaust duct7by the fin position controller324. As described in the control of the components inside the exhaust duct7, when the fins9are placed parallel to the exhaust duct7, there is no obstacle in the air flow path, so that the amount of exhaust flow from the drying section3increases. By positioning the fins9to be parallel to the exhaust duct7, the ejection of exhaust air from the image forming apparatus1can be performed efficiently, thereby promoting the cooling of the image forming apparatus1.

FIG. 11is a flowchart of a process to control the positions of fins9based on information on a print output. The control of the positions of fins9will now be described in detail with reference toFIG. 11.

When image information is input to the image forming apparatus1, the engine controller320receives the drawing information for printing to start print preparation (S1001). The state of the print preparation may be determined at the timing when the engine controller320receives the drawing information. The print preparation may include various conditions, for example, whether the recording medium P is set in the image forming apparatus1, whether sufficient amount of ink required of print output is ready, or whether the image forming apparatus1has recovered from an energy save mode.

Then, the print output information unit321determines whether the print preparation has been completed (S1002). Completion of the print preparation is determined according to whether conditions in S1001have been satisfied. If the print preparation has not been completed (“NO” in S1002), the print output information unit321executes the processing of S1001again.

If the print preparation has been completed (“YES” in S1002), the print output information unit321transmits to the duct controller323the print output information for performing print output.

On receiving the print output information, the duct controller323transmits to the fin position controller324the control information for keeping the fins9vertical to the exhaust path. Instructed by the control information, the fin position controller324positions the fins9to be vertical to the exhaust path (“FIN ON” in S1003).

Based on the received drawing information, the engine controller320performs a print output on the recording medium P (S1004). The duct controller323determines whether the print output has been completed (S1005). Completion of the print output is determined considering whether the print output has been performed on a predetermined number of recording media P or whether a signal instructing forced termination of printing is input to the engine controller320.

If the print output has not been completed (“NO” in S1005), the duct controller323checks the print condition (S1006). If there is no abnormality, the process returns to S1005. The print condition to be checked is, for example, whether the recording medium P has been used up before completion of printing or whether the temperature in the image forming apparatus1has become abnormal. In other words, whether the state of the image forming apparatus1allows continuing of print output is checked.

If the print output is completed (“YES” in S1005), the duct controller323transmits to the fin position controller324the control information for positioning the fins9to be parallel to the exhaust duct7. Instructed by the control information, the fin position controller324positions the fins9to be parallel to the exhaust duct7(“FIN OFF” in S1007).

The partition position controller326controls the positions of the drying-section partition11and the cooling-section partition12based on the control information transmitted from the duct controller323When the fins9are set to the on-state, the drying-section partition11is controlled to be placed to close the opening4, and the cooling-section partition12is controlled to be placed so as the exhaust air in the cooling section5to be mixed with the exhaust air in the exhaust duct7and the mixed exhaust gas to be ejected to the outside of the image forming apparatus1(seeFIG. 6). When the fins9are set to the off-state, the cooling-section partition12is controlled to be placed so as the exhaust air in the cooling section5and the exhaust air in the exhaust duct7not to be mixed with each other. The drying-section partition11is still in a state of closing the opening4in this state (seeFIG. 7).

When the fins9are placed to be parallel to the exhaust duct7, the drying-section partition11is placed to open the opening4. The cooling-section partition12is placed to separate the cooling section5from the exhaust duct7so that the exhaust air in the cooling section5and the exhaust air in the exhaust duct7do not mix with each other (seeFIG. 8).

The rotation of the fan10can be controlled according to temperatures of the exhaust duct7and the fins9detected by the temperature detector322. The fan10is controlled to rotate when the temperature in the exhaust duct7or of the fins9exceeds a predetermined temperature (for example, 60° C.) so that the external face of the exhaust duct7and the fins9are cooled. The fan10can be controlled to always rotate when the fins9are set to the on-state. In such a case, the duct controller323transmits to the fan drive controller325the control information for rotating the fan10when the fins9are set to the on-state among the controls of the fins9illustrated inFIG. 11.

A control similar to the process illustrated inFIG. 8may be performed during the maintenance of the image forming apparatus1to promote cooling of the image forming apparatus1.FIG. 12is an illustration of a configuration of the exhaust duct7with the front panel13of the image forming apparatus1opened.

The front panel13is provided to close the opening4. When the front panel13is opened, the panel opening-closing detector311outputs to the duct controller323the information indicating that the front panel13is opened, and thereby the image forming apparatus1performs the control illustrated inFIG. 8. A further larger amount of air can then be taken into the inside of the image forming apparatus1through the opening4, so that the amount of exhaust flow is further increased, thereby raising the cooling efficiency of the image forming apparatus1.

As described above, the image forming apparatus1according to the embodiment controls, based on print output information, which modes to be selected between the mode that prioritizes removal of moisture in the exhaust air and the mode that prioritizes exhaustion of a large amount of air. Controlled in such a manner, either the mode that prioritizes the removal of moisture inside the image forming apparatus1and the mode that prioritizes the cooling inside the apparatus is selected. Consequently, the image forming apparatus to which the present disclosure is applied can remove liquid in exhaust air without reducing the amount of exhaust flow, thereby efficiently performing cooling and drying.

The embodiment described above merely presents an exemplary embodiment of the present disclosure, but does not limit the scope of the present disclosure. Various embodiments can be set forth without departing from the technical scope of the present disclosure. For example, the temperature in the drying section3may become very high during a large number of continuous print outputs. When such an abnormally high temperature in the drying section3is detected, the control illustrated inFIG. 8may be performed to cool the drying section3before the next print output is performed, instead of immediately performing the next print output. With such a control, a print output can be performed with stable quality.