JP2020008791A - Image formation apparatus - Google Patents

Abstract

To provide an image formation apparatus which can suppress the temperature rise of a first belt in a configuration of cooling a recording material after fixation of a toner image with the first belt cooled with a heat sink.SOLUTION: When the belt temperature of a first belt is higher than the third temperature (Yes in S11), a control unit extends an interval of recording materials S by a prescribed interval (Yes in S12, S13). Due to the extension of the interval of the recording materials inserted to a recording material cooling device, the heat quantity of the recording material causing the temperature rise of the first belt can be reduced before the insertion to the recording material cooling device. Thus, the heat quantity flowing to the recording material cooling device through the recording material from a fixation device can be restricted regardless of the cooling performance of a heat sink. Consequently, the first belt can be easily maintained at the temperature capable of cooling the recording material by suppressing the temperature rise of the first belt due to the accumulation of the heat of the recording material on the first belt.SELECTED DRAWING: Figure 6

Description

  The present invention relates to an image forming apparatus such as a printer, a copying machine, a facsimile, or a multifunction peripheral using an electrophotographic method.

  2. Description of the Related Art In an electrophotographic image forming apparatus, a toner image formed on a recording material such as paper is heated and pressed by a fixing device to fix the toner image on the recording material. The fixing of the toner image is performed by nipping and conveying the recording material by a fixing roller heated by a heater or the like and a pressing roller pressed against the fixing roller. Since the recording material is heated when fixing the toner image, the temperature of the recording material discharged from the fixing device is likely to be higher than before the fixing. If a large number of recording materials conveyed while maintaining the temperature equal to or higher than the predetermined temperature are stacked on the stacking portion after the toner image is fixed, the stacked recording materials may be stuck to each other by the toner. In order to reduce the temperature of the recording material after fixing the toner image below a predetermined temperature, a cooling device for cooling the recording material discharged from the fixing device is provided in order to suppress the sticking of the recording material during loading. (Patent Document 1). In the cooling device described in Patent Literature 1, a heat sink (cooling unit) is provided on one of a pair of belts (rotating members) that rotate while nipping and conveying a recording material, and transfers heat conducted from the recording material to the belt from the heat sink. This is a cooling type device that lowers the temperature of the recording material by releasing heat.

  In the cooling method described above, for example, when a plurality of recording materials are continuously cooled, the heat radiation by the heat sink cannot catch up, and the temperature of the belt may increase. When the temperature of the belt increases, it becomes difficult to lower the temperature of the recording material. Therefore, an apparatus has been proposed in which the temperature of the heat sink can be adjusted by controlling the output of a cooling fan for cooling the heat sink so that the belt temperature does not increase (Patent Document 2).

JP 2009-181555 A JP 2014-35529 A

  By the way, since the fixing temperature of the fixing device is set for each type of recording material, the temperature of the recording material after fixing the toner image may vary depending on the type of recording material. Further, since the fixing temperature affects the glossiness of the toner image, the user can adjust the fixing temperature to obtain a desired glossiness. As described above, recent fixing devices can change the fixing temperature, and accordingly, the temperature of the recording material after fixing the toner image tends to vary widely. As one of methods for coping with this, there is a method of adjusting the temperature of the heat sink by controlling the output of a cooling fan that cools the heat sink as in the device described in Patent Document 2. However, the configuration for controlling the output of the cooling fan to suppress the temperature rise of the heat sink and thus the belt (rotating body) is complicated, and the cooling device may be increased in size and increased in cost. Therefore, a device that can suppress a rise in the temperature of a belt (rotary body) that is brought into contact with a recording material by a simpler method has been desired, but such a device has not yet been proposed.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has a configuration in which a recording material after a toner image is fixed is cooled by a rotating body that is cooled by a cooling unit. The purpose is to provide the device.

  An image forming apparatus according to the present invention includes an image forming unit that forms a toner image on a recording material, and a fixing device that heats the recording material on which the toner image is formed by the image forming unit and fixes the toner image on the recording material. A cooling unit having a rotating body that conveys the recording material in contact with the recording material on which the toner image has been fixed by the fixing device; and a cooling unit that cools the rotating body. Control means capable of executing a continuous image forming job for forming an image by performing the continuous image forming job, wherein the control means controls the temperature of the rotating body based on information on the temperature of the rotating body during execution of the continuous image forming job. When the temperature of the rotating body is higher than a predetermined temperature, the space between the preceding recording material and the next recording material is made longer than when the temperature of the rotating body is equal to or lower than the predetermined temperature, and the rotating body is passed through the cooling device. .

  An image forming apparatus according to the present invention includes an image forming unit that forms a toner image on a recording material, and a fixing device that heats the recording material on which the toner image is formed by the image forming unit and fixes the toner image on the recording material. A cooling unit having: a rotating body that conveys the recording material by contacting the recording material on which the toner image is fixed by the fixing device; and a cooling unit that cools the rotating body; the fixing device; and the cooling device. And a blower that is capable of blowing air toward the recording material sent from the fixing device to the cooling device, and a control capable of executing a continuous image forming job for continuously forming images on a plurality of recording materials. Means for controlling the blower when the temperature of the rotating body is higher than a predetermined temperature based on information on the temperature of the rotating body during execution of the continuous image forming job. Specially To.

  An image forming apparatus according to the present invention includes an image forming unit that forms a toner image on a recording material, and a fixing device that heats the recording material on which the toner image is formed by the image forming unit and fixes the toner image on the recording material. A cooling unit having a rotating body that conveys the recording material in contact with the recording material on which the toner image has been fixed by the fixing device; and a cooling unit that cools the rotating body. Control means capable of executing a continuous image forming job for forming an image by performing the continuous image forming job, wherein the control means controls the temperature of the rotating body based on information on the temperature of the rotating body during execution of the continuous image forming job. When the temperature is higher than a predetermined temperature, the heating amount of the recording material by the fixing device is made lower than the heating amount when the temperature of the rotating body is equal to or lower than the predetermined temperature.

  According to the present invention, in a configuration in which a recording material after a toner image is fixed is cooled by a rotating body cooled by a cooling unit, it is possible to easily realize an increase in the temperature of the rotating body.

FIG. 1 is a schematic diagram illustrating a configuration of an image forming apparatus according to an embodiment. FIG. 2 is a schematic diagram illustrating an image forming unit. FIG. 2 is a perspective view illustrating a fixing device. FIG. 2 is a schematic diagram showing a recording material cooling device. FIG. 3 is a control block diagram for explaining a control unit. 5 is a flowchart illustrating a calorific value reduction process according to the first embodiment. 5 is a graph illustrating a relationship between a recording material interval and productivity in the image forming apparatus. 9 is a flowchart illustrating a calorific value reduction process according to the second embodiment. 9 is a flowchart illustrating a setting process of a heat quantity reduction method by a user. It is a figure which shows a screen display, (a) is an initial screen, (b) is a type selection screen, (c) is a setting screen.

[First embodiment]
<Image forming apparatus>
A schematic configuration of the image forming apparatus according to the present embodiment will be described with reference to FIGS. The image forming apparatus 100 shown in FIG. 1 is an electrophotographic tandem-type full-color printer. The image forming apparatus 100 includes image forming units PY, PM, PC, and PK that form yellow, magenta, cyan, and black images, respectively. The image forming apparatus 100 records a toner image in accordance with an image signal from an original reading device (not shown) connected to the apparatus main body 100A or an external device such as a personal computer communicably connected to the apparatus main body 100A. Formed on S. Examples of the recording material S include various types of sheet materials such as plain paper, thick paper, rough paper, irregular paper, paper such as coated paper, plastic film, and cloth. In the present embodiment, the image forming units PY, PM, PC, PK, the intermediate transfer belt 8, the roller 9, and the secondary transfer roller 10 constitute an image forming unit that forms a toner image on the recording material S.

  As shown in FIG. 1, the image forming units PY, PM, PC, and PK are arranged in the apparatus main body 100A (in the apparatus main body) along the moving direction of the intermediate transfer belt 8. The intermediate transfer belt 8 is stretched around a plurality of rollers, and is configured to run in the direction of arrow R2. Then, the intermediate transfer belt 8 carries and transports the primary-transferred toner image. A secondary transfer roller 10 is disposed at a position facing the roller 9 that stretches the intermediate transfer belt 8 with the intermediate transfer belt 8 interposed therebetween, and the secondary transfer roller 10 transfers the toner image on the intermediate transfer belt 8 to the recording material S. The transfer section T2 is configured. A fixing device 11 is disposed downstream of the secondary transfer section T2 in the recording material conveyance direction.

  A cassette 12 containing a recording material S is disposed below the image forming apparatus 100. The recording material S is conveyed from the cassette 12 to the registration roller 14 by the conveyance roller 13 along a conveyance path 600 that forms a path of the recording material S in the apparatus main body 100A. The transport roller 13 is driven to rotate by a second motor (see FIG. 5 described later). Thereafter, as the registration roller 14 starts rotating in synchronization with the toner image formed on the intermediate transfer belt 8 as described later, the recording material S is transported along the transport path 600 to the secondary transfer portion T2. You. Although only one cassette 12 is shown here, a plurality of cassettes 12 may be arranged so as to be able to accommodate recording materials S having different sizes and thicknesses. The recording material S is selectively conveyed to the conveyance path 600. In addition, not only the recording material S accommodated in the cassette 12 but also the recording material S placed on a manual feed unit (not shown) may be conveyed to the conveyance path 600.

<Image forming unit>
The four image forming units PY, PM, PC, and PK included in the image forming apparatus 100 have substantially the same configuration except that development colors are different. Therefore, here, the image forming unit PK will be described as a representative, and the description of the other image forming units PY, PM, and PC will be omitted.

  As shown in FIG. 2, the image forming unit PK includes a cylindrical photosensitive drum 1 as a photosensitive member. The photosensitive drum 1 is driven to rotate in the direction of arrow R1. Around the photosensitive drum 1, a charging device 2, an exposure device 3, a developing device 4, a primary transfer roller 5, and a cleaning device 6 are arranged.

  A process of forming, for example, a full-color image by the image forming apparatus 100 will be described. First, when the image forming operation is started, the surface of the rotating photosensitive drum 1 is uniformly charged by the charging device 2. The charging device 2 is, for example, a corona charger that irradiates charged particles accompanying corona discharge to charge the photosensitive drum 1 to a uniform negative dark potential. Next, the photosensitive drum 1 is scanned and exposed by a laser beam L corresponding to an image signal emitted from the exposure device 3. As a result, an electrostatic latent image corresponding to the image signal is formed on the surface of the photosensitive drum 1. The electrostatic latent image formed on the photosensitive drum 1 is visualized by a toner (developer) stored in the developing device 4 and becomes a visible image.

  The toner image formed on the photosensitive drum 1 is primarily transferred to the intermediate transfer belt 8 at a primary transfer section T1 formed between the photosensitive drum 1 and a primary transfer roller 5 disposed with the intermediate transfer belt 8 interposed therebetween. At this time, a primary transfer bias is applied to the primary transfer roller 5. The toner remaining on the surface of the photosensitive drum 1 after the primary transfer is removed by the cleaning device 6.

  Such operations are sequentially performed in the yellow, magenta, cyan, and black image forming units PY to PK, and the four color toner images are superimposed on the intermediate transfer belt 8. After that, the recording material S stored in the cassette 12 is transported to the secondary transfer portion T2 at the timing of forming the toner image. Then, by applying a secondary transfer bias to the secondary transfer roller 10, the full-color toner image formed on the intermediate transfer belt 8 is collectively and secondarily transferred onto the recording material S.

  Next, the recording material S is transported to the fixing device 11. As will be described later in detail (see FIG. 3), the fixing device 11 includes a rotatable fixing roller 11a and a pressure roller 11b that rotates while being pressed against the fixing roller 11a. The fixing roller 11a is rotated at a predetermined rotation speed (for example, 400 mm / sec) by a drive motor (not shown) in a state where the fixing roller 11a is pressed against the pressure roller 11b at, for example, a total pressure of about 784 N (about 80 kg). The fixing device 11 heats the conveyed recording material S by nipping and conveying the recording material S on which the toner image is formed in the fixing nip T3 formed by the rotating fixing roller 11a and the pressing roller 11b. Pressure is applied to fix the toner image on the recording material S. That is, the toner of the toner image formed on the recording material S is melted and mixed by heating and pressing, and is fixed on the recording material S as a full-color image. Thus, a series of image forming processes is completed. Then, the recording material S on which the toner image is fixed is conveyed to the recording material cooling device 20. The recording material cooling device 20 as a cooling device cools the recording material S. The recording material cooling device 20 will be described later (see FIG. 4).

  The image forming apparatus 100 of the present embodiment can perform double-sided printing. In the case of single-sided printing, the recording material S cooled by the recording material cooling device 20 is discharged out of the apparatus main body 100A (outside the apparatus main body) by the paper discharge roller 15, and is stacked on the stacking unit 60. On the other hand, in the case of double-sided printing, the recording material S cooled by the recording material cooling device 20 is reversed in the transport path 600, so that the front surface and the back surface of the recording material S are switched. The reversed recording material S is conveyed along the conveyance path 600 toward the registration roller 14, and is transferred to the secondary transfer unit T <b> 2 with the back side not printed by the registration roller 14 facing the intermediate transfer belt 8. Conveyed. In the secondary transfer section T2, the full-color toner image formed on the intermediate transfer belt 8 is collectively secondary-transferred onto the recording material S (back side). Thereafter, the recording material S is subjected to fixing of the toner image by the fixing device 11 and cooling by the recording material cooling device 20, and the cooled recording material S is discharged out of the apparatus main body 100A and loaded on the loading unit 60.

<Fixing device>
The fixing device 11 will be described with reference to FIG. As shown in FIG. 3, the fixing device 11 has a fixing roller 11a and a pressure roller 11b. The fixing roller 11a is formed to have a diameter of 60 mm by disposing an elastic layer having a thickness of 3 mm on an outer peripheral surface of a cored bar made of, for example, an aluminum cylinder. The lower layer of the elastic layer is an HTV (high temperature vulcanization type) silicone rubber layer, and an RTV (room temperature vulcanization type) silicone rubber layer as a heat resistant elastic layer to be brought into contact with the image surface is disposed on the outer peripheral surface of the HTV silicon rubber layer. Have been. A fluororesin layer is disposed on the outermost layer. On the other hand, the pressure roller 11b is formed to have the same diameter as the fixing roller 11a with a diameter of 60 mm by disposing an elastic layer having a thickness of 1 mm on the outer peripheral surface of, for example, an aluminum cylindrical core. The lower layer of the elastic layer is an HTV silicone rubber layer, and a fluororesin layer is arranged on the outer peripheral surface of the HTV silicone rubber layer.

A halogen heater 110 is disposed in the fixing roller 11a in a non-rotating manner, and the surface temperature of the fixing roller 11a is increased by the halogen heater 110. Thereby, the fixing device 11 can heat the recording material S. Temperature sensors 80a and 80b are arranged at the center and the end of the fixing roller 11a in the rotation axis direction, respectively. The temperature sensors 80a and 80b are, for example, thermistors or the like, and can detect the surface temperature of the fixing roller 11a. The surface temperature of the fixing roller 11a is adjusted to a fixing temperature (for example, about 150 to 200 ° C.) at which the toner can be fixed on the recording material by controlling the temperature of the halogen heater 110 based on the detection results of the temperature sensors 80a and 80b. . This fixing temperature differs depending on the type of the recording material S and the glossiness of the toner image after fixing. For example, in the case of a recording material S (for example, Great White recycled copy paper manufactured by HANMER MILL) having a small basis weight and a temperature that easily rises, the surface temperature of the fixing roller 11a is adjusted to about 155 ° C. On the other hand, in the case of a recording material S having a large basis weight and a surface coated with a resin and having a large heat capacity (for example, mirror coat platinum of Oji Paper Co., Ltd., basis weight of 256 g / m ² ), the surface temperature of the fixing roller 11a is 180 °. It is adjusted to about ° C. Further, when the user desires more glossiness by using, for example, the above-mentioned mirror coat platinum, the surface temperature of the fixing roller 11a is adjusted to about 190 ° C.

  When the recording material S is continuously passed through the fixing device 11, a difference occurs in the surface temperature between a passing portion of the fixing roller 11a where the recording material S passes and a non-passing portion where the recording material S does not pass. This is because the temperature control of the halogen heater 110 is determined based on the detection result of the temperature sensor 80a disposed at the center where the recording material S is likely to lose heat when passing through the recording material S. In this case, the temperature of the end portion side (non-passing portion) of the fixing roller 11a when heated by the halogen heater 110 becomes the central portion (passing portion) where the temperature is reduced by the heat taken by the recording material S. It is easy to get higher than that. However, if the temperature difference between the center and the end of the fixing roller 11a becomes large, a difference in the outer diameter of the roller occurs between the center and the end due to thermal expansion, so that the recording material S cannot be properly conveyed, and the fixing failure is caused. Can occur. In order to prevent this, it is necessary to detect the temperature of the fixing roller 11a also at the end portion other than the center portion. Therefore, in the present embodiment, in order to detect the temperature of the non-passing portion based on the recording material S (for example, A4 or LTR size paper), the temperature is set at a position of about 155 mm from the center of the fixing roller 11a toward the end. The sensor 80b is arranged.

  In the case of the present embodiment, the fixing device 11 has a hollow duct 81 and an end cooling fan 82 attached to the duct 81. The duct 81 is arranged along the rotation axis direction of the fixing roller 11a, and both ends thereof face the fixing roller 11a. The duct 81 formed in a substantially U-shape has openings 81a, 81b, 81c at both ends and a center thereof. An end cooling fan 82 is attached to the opening 81c. The end cooling fan 82 blows air into the duct 81 from the opening 81c in order to send air from the openings 81a and 81b toward the end of the fixing roller 11a. As the end cooling fan 82, for example, a sirocco fan, a cross flow fan, an axial fan, or the like is used. The end cooling fan 82 is controlled according to the temperature of the fixing roller 11a detected by the temperature sensor 80b.

<Recording material cooling device>
Next, the recording material cooling device 20 will be described with reference to FIG. In the case of the present embodiment, the recording material cooling device 20 is a device for cooling the recording material S by a belt cooling method. As shown in FIG. 4, the recording material cooling device 20 includes an endless first belt 21 and an endless second belt 25 that sandwiches and conveys the first belt 21 and the recording material S. For example, the first belt 21 and the second belt 25 are made of high-strength polyimide, and have a thickness of 100 μm and a circumference of 942 mm. Further, the recording material cooling device 20 has a heat sink 30 that cools at least one of the first belt 21 and the second belt 25 as a rotating body.

  As shown in FIG. 4, the first belt 21 is wound around a plurality of first belt stretching rollers 22a to 22d, and at least one of the first belt stretching rollers 22a to 22d is rotated by a belt driving motor 51. Let me do. On the other hand, the second belt 25 is wound around a plurality of second belt stretching rollers 26 a to 26 d and is in contact with the first belt 21. At least one of the second belt stretching rollers 26 a to 26 d is rotated by the belt drive motor 51. Here, the first belt stretching roller 22d and the second belt stretching roller 26d are driven by a belt drive motor 51 via a drive gear (not shown). Thereby, the first belt 21 rotates in the direction of arrow B in the figure, and the second belt 25 rotates in the direction of arrow C in the figure. The second belt tension roller 26d is pressed against the first belt tension roller 22d at about 49 N (about 5 kgf). By pressing the second belt 25 toward the first belt 21, the cooling nip T4 is formed, and the first belt 21 is securely connected to the heat sink 30 (specifically, a heat receiving unit 30a described later) via the second belt 25. Abutting.

  Here, the recording material S is nipped and conveyed by the first belt 21 and the second belt 25. However, the present invention is not limited to this, and the recording material S may be nipped and conveyed by a pair of metal rollers (rotary members). Good. In that case, at least one of the pair of metal rollers may be cooled by the heat sink 30. Further, the present invention is not limited to driving both the first belt 21 and the second belt 25. The first belt 21 may be driven to cause the second belt 25 to follow the first belt 21. The first belt 21 may be driven by the second belt 25 by driving the belt 25.

  The recording material S on which the toner image discharged from the image forming apparatus 100 is fixed is sandwiched between the first belt 21 and the second belt 25, and rotates in the transport direction (the direction of arrow C in the drawing) according to the rotation of the first belt 21 and the second belt 25. Conveyed. At that time, the recording material S passes through the cooling nip T4 formed by the contact between the first belt 21 and the second belt 25. In the case of the present embodiment, the first belt 21 is cooled by the heat sink 30. The heat sink 30 is disposed so as to abut the inner surface of the first belt 21 at a position where the cooling nip T4 is formed in order to efficiently cool the recording material S. The recording material S is cooled via the first belt 21 when passing through the cooling nip T4. As an example, when the temperature of the recording material S is about 90 ° C. before passing through the recording material cooling device 20, the recording material S is cooled so as to be approximately 70 ° C. after passing through the recording material cooling device 20. (For example, in the case of the above-mentioned Great White recycled copy paper).

The heat sink 30 as a cooling means is a radiator plate formed of a metal such as aluminum. The heat sink 30 contacts the first belt 21 and removes heat from the first belt 21 (absorbs heat), a heat dissipating heat dissipating portion 30b, and transfers heat from the heat receiving portion 30a to the heat dissipating portion 30b. And a fin base 30c. The heat dissipating portion 30b is formed by a large number of heat dissipating fins in order to increase the contact area with air and promote efficient heat dissipation. For example, the radiation fins are set to have a thickness of 1 mm, a height of 100 mm, and a pitch of 5 mm, and the fin base 30c has a thickness of 10 mm. In order to forcibly cool the heat sink 30 itself, a sink cooling fan 40 that blows air toward the heat sink 30 (specifically, the heat radiating portion 30b) is provided. The air volume of the sink cooling fan 40 is set to, for example, 2 m ³ / min.

  The heat sink 30 may be in contact with one of the first belt 21 and the second belt 25, and is not limited to contact with the first belt 21 to cool the first belt 21 as described above. The second belt 25 may be cooled by contacting the second belt 25. However, it is preferable that the heat sink 30 be in contact with either the first belt 21 or the second belt 25 that is in contact with the recording material S on the surface on which the toner image is formed by the fixing device 11.

  In the case of the present embodiment, the heat sink 30 is in contact with the first belt 21. Further, a belt temperature sensor 50 as a temperature detecting means is disposed downstream of the heat receiving portion 30a in contact with the first belt 21 in the rotation direction of the first belt 21 (the direction of arrow B in the drawing). The belt temperature sensor 50 is in contact with the first belt 21 to detect a belt temperature of the first belt 21 (information on the temperature of the rotating body). However, when the first belt 21 is brought into contact with the belt temperature sensor 50, there may be a difference in surface properties between the contact portion and the non-contact portion. If there is a difference in the surface properties of the first belt 21 on the side facing the recording material S, there is a possibility that an unintended gloss difference may occur in the toner image on the recording material S. Therefore, the belt temperature sensor 50 is in contact with the inner surface of the first belt 21 that does not face the recording material S (specifically, the polyimide layer that is the base layer of the first belt 21). Further, the first belt 21 is cooled by deprived of heat by the heat receiving unit 30a, and in order to correctly determine the cooling effect of the cooled first belt 21 on the recording material S, the belt temperature after passing through the heat receiving unit 30a is determined. Is desirably detected. Therefore, the belt temperature sensor 50 is in contact with the first belt 21 on the downstream side in the rotation direction of the first belt 21 from the heat receiving unit 30a.

  Further, as shown in FIG. 4, a blower fan 70 and a duct 71 as a blower may be arranged between the fixing device 11 and the recording material cooling device 20 on the conveyance path of the recording material S. The hollow duct 71 is arranged so that air generated by the blower fan 70 can be blown from below the conveyance path to the recording material S conveyed from the fixing device 11 to the recording material cooling device 20. By blowing air as quickly as possible on the recording material S discharged from the fixing device 11 after fixing the toner image, curling of the recording material S by heat is suppressed, or the recording material S is controlled by humidity. To prevent dew condensation from occurring. As the blower fan 70, for example, a sirocco fan, a cross flow fan, an axial fan, or the like is used.

<Control unit>
As shown in FIG. 1, the image forming apparatus 100 includes a control unit 300. The control unit 300 will be described with reference to FIGS. It should be noted that various devices such as a motor and a power supply for operating the image forming apparatus 100 are connected to the control unit 300 in addition to the illustrated ones. However, since these are not the gist of the present invention, their illustration and description are omitted. .

  The control unit 300 as a control unit performs various controls of the image forming apparatus 100 such as an image forming operation, and has a CPU 301 (Central Processing Unit) and a memory 302 such as a ROM, a RAM, or a hard disk device. The memory 302 stores, for example, various programs such as a continuous image forming job and a heat amount reduction process (see FIGS. 6, 8, and 9 described later), various data, and the like. The control unit 300 can execute various programs stored in the memory 302, and can operate the image forming apparatus 100 by executing the various programs. Note that the memory 302 can also temporarily store the results of arithmetic processing accompanying the execution of various programs.

  An operation unit 400 is connected to the control unit 300 via an input / output interface. The operation unit 400 is, for example, an external terminal such as a personal computer or a scanner, or an operation panel that accepts a user's instruction to start various programs such as a continuous image forming job and various data inputs.

  Here, the continuous image forming job is a period from the start of image formation to the completion of the image forming operation based on a print signal for continuously forming images on a plurality of recording materials. More specifically, it refers to a period from a pre-rotation (preparation operation before image formation) after receiving a print command signal (input of an image forming job) to a post-rotation (operation after image formation). , The period including the sheet interval. Note that, for example, when one job is followed by another job, these are collectively determined as one job.

  For example, when an instruction to start a continuous image forming job is issued from the operation unit 400, the control unit 300 executes an image forming process (program) stored in the memory 302. The control unit 300 controls the image forming apparatus 100 based on the execution of the image forming processing. A halogen heater 110 is connected to the control unit 300, and the control unit 300 sets the fixing temperature to a temperature according to the type of the recording material S input from the operation unit 400 when performing the image forming process, The halogen heater 110 is controlled to heat the fixing roller 11a. Temperature sensors 80a and 80b are connected to the control unit 300, and the control unit 300 starts image formation after waiting for detection of the fixing temperature by the temperature sensors 80a and 80b.

  Further, the belt temperature sensor 50, the first motor 410, the second motor 411, the third motor 412, and the fourth motor 413 are connected to the controller 300. In the case of the present embodiment, the control unit 300 executes the heat quantity reduction processing described later (see FIGS. 6 and 8) every predetermined time (for example, every time the five recording materials S pass through the recording material cooling device 20). 2), the belt temperature of the first belt 21 is acquired from the belt temperature sensor 50. The control unit 300 controls the first motor 410 to control the start and stop of the driving of the end cooling fan 82. The control unit 300 controls the second motor 411 to control the start and stop of the rotation of the transport roller 13. In the case of the present embodiment, the control unit 300 controls the start and stop of the rotation of the conveying roller 13 so that the interval between the recording materials conveyed from the fixing device 11 to the recording material cooling device 20 described later can be adjusted. ing. That is, in the present embodiment, the control unit 300 controls the conveyance interval of the recording material S to the recording material cooling device 20 by controlling the timing of sending the recording material from the cassette 12. The interval of the recording material S passing through the recording material cooling device 20 is defined as the interval between the rear end of the preceding recording material S (the n-th sheet) reaching the cooling nip T4 of the recording material cooling device 20 and the next recording material S. It means the time until the leading edge of the (n + 1) th sheet reaches the cooling nip T4 of the recording material cooling device 20. The control unit 300 controls the third motor 412 to control the start and stop of the driving of the sink cooling fan 40. The control unit 300 controls the fourth motor 413 to control the start and stop of the driving of the blower fan 70.

  By the way, when the recording material cooling device 20 is of the above-described belt cooling type, the temperature of the recording material S is lowered via the first belt 21 cooled by the heat sink 30. However, in the case of the belt cooling method, for example, when a continuous image forming job is executed, the heat radiation by the heat sink 30 cannot catch up, and the belt temperature of the first belt 21 (and the second belt 25) tends to increase. Then, it is difficult to lower the temperature of the recording material S. This is because the heat of the recording material S is conducted to the heat sink 30 via the first belt 21 and radiated, but when a plurality of recording materials S are conveyed continuously, the heat radiated by the heat sink 30 is dissipated. This is because heat cannot be caught up and the first belt 21 stores heat. As described above, if the temperature of the recording material S after fixing the toner image cannot be lowered below the predetermined temperature, the recording material S may be stuck during stacking. Therefore, in the present embodiment, even if a plurality of recording materials S are continuously conveyed, the belt temperature of the first belt 21 is not increased to a predetermined temperature (for example, 75 ° C.) at which toner is less likely to adhere. The heat of the recording material S is prevented from being stored in the first belt 21. This will be described below.

<Heat reduction processing>
First, the calorific value reduction processing of the first embodiment will be described with reference to FIGS. 1, 4, and 5 using FIG. The heat amount reduction process of the present embodiment is executed by the control unit 300, for example, at the start of a continuous image forming job, and determines the heat amount of the recording material S that causes the temperature of the first belt 21 to rise. It is to be reduced as much as possible before entering the 20. In FIG. 6 (and FIG. 8 to be described later), for convenience of illustration, a part of the judgment is described as “judgment” in the figure, but these are specific processes described below.

  As shown in FIG. 6, the control unit 300 determines that the central temperature (t1) of the central part of the fixing roller 11a detected by the temperature sensor 80a is a desired fixing temperature (A1, for example, 190 ° C.) ) Is determined (S1). When the central temperature (t1) of the fixing roller 11a is higher than the desired fixing temperature (A1) (Yes in S1), the controller 300 controls the halogen heater 110 to stop heating the fixing roller 11a (S2). When the central temperature (t1) of the fixing roller 11a is equal to or lower than the predetermined fixing temperature (A1) (No in S1), the controller 300 controls the halogen heater 110 to heat the fixing roller 11a (S3). At this time, the control unit 300 operates the sink cooling fan 40 of the recording material cooling device 20. After the processing in S2 or S3, the control section 300 proceeds to the processing in S4. The controller 300 determines that the central temperature (t1) of the fixing roller 11a detected by the temperature sensor 80a is higher than a predetermined threshold temperature (A2, for example, 210 ° C.) for determining an abnormal temperature state, as “determination 2” in the drawing. Is determined (S4).

  For example, when it is desired to set the surface temperature of the fixing roller 11a to 190 ° C. in order to form a high gloss image on the recording material S of the mirror-coated platinum, the fixing temperature (A1) is 190 ° C. and the threshold temperature (A2 ) Is set at 210 ° C. The threshold temperature (A2) may be any temperature at which an abnormal temperature rise of the fixing roller 11a can be determined.

  When the central temperature (t1) of the fixing roller 11a is higher than the threshold temperature (A2) (Yes in S4), if the halogen heater 110 is heating the fixing roller 11a, the control unit 300 performs heating by the halogen heater 110. Is stopped (S22). Then, the control unit 300 performs a stop process for stopping the conveyance of the recording material S from the fixing device 11 to the recording material cooling device 20 (S23). Here, when an abnormal temperature rise of the fixing roller 11a occurs due to overheating of the halogen heater 110, the control unit 300 stops the conveyance of the recording material S to the recording material cooling device 20. Specifically, the conveyance of the recording material S by the conveyance roller 13 is stopped, and the rotation of the fixing roller 11a and the pressure roller 11b is stopped.

  On the other hand, when the central temperature (t1) of the fixing roller 11a is equal to or lower than the threshold temperature (A2) (No in S4), the control unit 300 executes the processing in S5. The controller 300 determines that the difference between the end temperature (t2) on the end side of the fixing roller 11a detected by the temperature sensor 80b and the center temperature (t1) of the fixing roller 11a is a predetermined value, as "decision 3" in the drawing. It is determined whether it is larger than the first temperature difference (B1, for example, 30 ° C.) (S5). Alternatively, the controller 300 determines whether the end temperature (t2) of the fixing roller 11a is higher than a predetermined first temperature (B2, for example, 230 ° C.) (S5). When the difference between the end temperature (t2) and the center temperature (t1) is larger than the first temperature difference (B1), or the end temperature (t2) is higher than the first temperature (B2) (Yes in S5). , The control unit 300 proceeds to the process of S6. In cases other than the above (No in S5), the control unit 300 jumps to the processing in S11.

  The control unit 300 determines whether or not the end cooling fan 82 is operating as “determination 4” in the drawing (S6). When the end cooling fan 82 is not operating (No in S6), the control unit 300 operates the end cooling fan 82 (S9), and then jumps to the processing of S10. When the end cooling fan 82 is operating (Yes in S6), the control unit 300 determines, as “judgement 5” in the drawing, the interval (Ts, here, time, of the recording material S passing through the recording material cooling device 20). ) Is shorter than a predetermined longest interval (for example, 1200 ms) (S7). When the interval (Ts) between the recording materials S is shorter than the longest interval (Yes in S7), the control unit 300 increases the interval (Ts) between the recording materials S by a predetermined interval (for example, 90 ms) (S8), and then proceeds to S10. Proceed to processing. When the interval (Ts) of the recording materials S is equal to or longer than the longest interval (No in S7), the control unit 300 proceeds to the process of S10 without changing the interval (Ts) of the recording materials S.

  In the case of this embodiment, the conveyance speed of the recording material S in the fixing device 11 is set to 400 mm / sec, and the interval (Ts) of the recording material S is set to 120 ms (initial value). Next, it is determined whether or not the processing for reducing the temperature difference between the central portion and the end portion is performed. In order to reduce the temperature difference between the center and the end of the fixing roller 11a, the processing of operating the end cooling fan 82 and extending the interval (Ts) between the recording materials S as described above is executed. It is possible. When the interval (Ts) between the recording materials S is extended, the interval (Ts) between the recording materials S is extended by 90 ms until the interval (Ts) reaches the longest allowable value of 1200 ms. In this case, as the interval (Ts) of the recording material S passing through the fixing device 11 becomes longer (wider), the amount of heat taken by the recording material S from the fixing roller 11a can be reduced. The temperature difference between the (contact portion) and the end (non-contact portion) can be reduced.

  The controller 300 determines that the difference between the end temperature (t2) and the center temperature (t1) is larger than a predetermined second temperature difference (B3, for example, 45 ° C.) or determines the end temperature ( It is determined whether or not t2) is higher than a predetermined second temperature (B4, for example, 240 ° C.) (S10). When the difference between the end temperature (t2) and the center temperature (t1) is larger than the second temperature difference (B3), or when the end temperature (t2) is larger than the second temperature (B4) (Yes in S10). , The control unit 300 jumps to the processing of S22. In cases other than the above (No in S10), the control unit 300 proceeds to the processing in S11.

  For example, when fixing the recording material S of the LTR size of the above-mentioned mirror coat platinum at a fixing temperature (A1 ° C.) of 190 ° C., the first temperature difference (B1) is 30 ° C., the first temperature (B2) is 230 ° C., and the first temperature difference (B2) is 230 ° C. The two temperature difference (B3) is set to 45 ° C, and the second temperature (B4) is set to 240 ° C. The first temperature difference (B1) and the second temperature difference (B3) are set to temperatures at which no fixing failure occurs due to the passage of the recording material S. Further, the first temperature (B2) and the second temperature (B4) are set to temperatures according to the heat-resistant temperature of the fixing roller 11a.

  The controller 300 determines that the belt temperature (t3) of the first belt 21 detected by the belt temperature sensor 50 is lower than a predetermined third temperature (C1, for example, 75 ° C.) at which toner is unlikely to adhere as “decision 7” in the drawing. Is higher (S11). When the belt temperature (t3) of the first belt 21 is equal to or lower than the third temperature (not higher than the predetermined temperature) (No in S11), the control unit 300 jumps to the processing in S14.

  On the other hand, when the belt temperature (t3) of the first belt 21 is higher than the third temperature (C1) (Yes in S11), the control unit 300 performs the above-described "judgment 5" (S12). When the interval (Ts) between the recording materials S is shorter than the longest interval (Yes in S12), the control unit 300 increases the interval (Ts) between the recording materials S by a predetermined interval (for example, 90 ms) (S13). ), And proceeds to the process of S14. That is, when the belt temperature (t3) of the first belt 21 is higher than the third temperature (C1), the recording medium is continuously passed through the recording material cooling device 20 in order to lower the belt temperature (t3) of the first belt 21. The interval (Ts) between the recording materials S is increased. By making the interval (Ts) between the recording materials S longer than the case where the belt temperature of the first belt 21 is equal to or lower than the third temperature, the heat of the recording material S heated by the fixing causes the first belt 21 (and the second belt 21). 25) It becomes possible to reduce the amount of heat stored.

  When the interval (Ts) of the recording materials S is equal to or longer than the longest interval (No in S12), the control unit 300 proceeds to the process of S14 without changing the interval (Ts) of the recording materials S. This is because if the interval (Ts) between the recording materials S is longer than the longest interval, the productivity in the image forming apparatus 100 is significantly reduced. FIG. 7 shows a relationship between the interval between the recording materials S and the productivity in the image forming apparatus 100. As can be understood from FIG. 7, the greater the interval between the recording materials S, the lower the productivity related to image formation in the image forming apparatus 100. The interval between the recording materials S that can tolerate such a decrease in productivity is the above-described longest interval. In the present embodiment, the longest interval is set to 1200 ms.

  Returning to FIG. 6, the control unit 300 determines whether the belt temperature (t3) of the first belt 21 is higher than the fourth temperature (C2, for example, 80 ° C.) as “Decision 8” in the drawing (S14). When the belt temperature (t3) of the first belt 21 is higher than the fourth temperature (C2) (Yes in S14), the control unit 300 stops heating by the halogen heater 110 (S22) and performs a stop process (S23). . On the other hand, when the belt temperature (t3) of the first belt 21 is equal to or lower than the fourth temperature (C2) (No in S14), the controller 300 proceeds to the processing in S15.

  For example, when fixing the recording material S of the LTR size of the mirror-coated platinum at a fixing temperature (A1 ° C.) of 190 ° C., the third temperature (C1) is set to 75 ° C. and the fourth temperature (C2) is set to 80 ° C. You. The third temperature (C1) and the fourth temperature (C2) may be set based on the length of the transport path from the recording material cooling device 20 to the stacking unit 60, the number of stackable units of the stacking unit 60, the environmental temperature, and the like. The above-mentioned temperature is, for example, a temperature at which the image forming apparatus 100 is placed in an environment of a temperature of 25 ° C. and 1000 sheets of the recording materials S are stacked on the stacking unit 60 so that the recording materials S are not stuck at the time of stacking. is there.

  The control unit 300 determines that the difference between the end temperature (t2) and the center temperature (t1) is equal to or less than the first temperature difference (B1) or the end temperature (t2) It is determined whether the temperature is equal to or lower than the temperature (B2) (S15). When the difference between the end temperature (t2) and the center temperature (t1) is larger than the first temperature difference (B1), or when the end temperature (t2) is larger than the first temperature (B2) (No in S15). , The control unit 300 jumps to the processing of S18. The control unit 300 determines whether or not the belt temperature (t3) of the first belt 21 is equal to or lower than the third temperature (C1) as “decision 10” in the drawing (S18). When the belt temperature (t3) of the first belt 21 is equal to or lower than the third temperature (C1) (Yes in S18), the control unit 300 proceeds to the processing in S19. When the belt temperature (t3) of the first belt 21 is higher than the third temperature (C1) (No in S18), the control unit 300 jumps to the processing in S21.

  In S15, when the difference between the end temperature (t2) and the center temperature (t1) is equal to or less than the first temperature difference (B1), or the end temperature (t2) is equal to or less than the first temperature (B2) (Yes in S15). ), The control section 300 performs the above-mentioned "determination 4" process (S16). If the end cooling fan 82 is operating (Yes in S16), the control unit 300 stops the end cooling fan 82 (S17), and then jumps to the processing in S21. When the end cooling fan 82 is not operating (No in S16), the control unit 300 proceeds to the processing in S19.

  The control unit 300 determines whether the interval (Ts) between the recording materials S is longer than an initial value (for example, 120 ms) as “determination 11” in the drawing (S19). When the interval (Ts) of the recording materials S is longer than the initial value (Yes in S19), the control unit 300 shortens (narrows) the interval (Ts) of the recording materials S by a predetermined interval (for example, 90 ms) (S20), and proceeds to S21. Proceed to processing. When the interval (Ts) of the recording materials S is equal to or less than the initial value (No in S19), the control unit 300 proceeds to the process of S21 without changing the interval (Ts) of the recording materials S.

  The control unit 300 determines whether or not the continuous image forming job has been completed (S21). When the continuous image forming job is completed (Yes in S21), the control unit 300 stops heating by the halogen heater 110 (S22) and performs a stop process (S23). On the other hand, if the continuous image forming job has not been completed (No in S21), the control unit 300 returns to the processing in S1 without performing the stop processing and continues the processing.

  As described above, in the present embodiment, when a plurality of recording materials S are conveyed continuously, the interval Ts between the recording materials S is increased (widened) according to the temperature of the first belt 21. Was made possible. By increasing the interval Ts between the recording materials S that enter the recording material cooling device 20, the amount of heat of the recording material S that causes the temperature rise of the first belt 21 can be reduced before the recording material S enters the recording material cooling device 20. It can be reduced as much as possible. That is, the amount of heat flowing from the fixing device 11 to the recording material cooling device 20 via the recording material S can be limited regardless of the cooling capability of the heat sink 30. Therefore, in the present embodiment, the temperature rise of the first belt 21 due to the heat of the recording material S being stored in the first belt 21 is suppressed, and the first belt 21 is maintained at a temperature at which the recording material S can be cooled. Can be easily done.

[Second embodiment]
Next, a calorific value reduction process according to the second embodiment will be described with reference to FIGS. 1, 4, and 5, using FIG. However, in the calorie reduction process of the second embodiment shown in FIG. 8, the same processes as those of the calorie reduction process of the first embodiment (see FIG. 6) are denoted by the same reference numerals, and the description is simplified or omitted.

  As shown in FIG. 8, the controller 300 determines whether the central temperature (t1) at the center of the fixing roller 11a detected by the temperature sensor 80a is higher than a desired fixing temperature (A1) (decision 1). : S1). When the central temperature (t1) of the fixing roller 11a is higher than the desired fixing temperature (A1) (Yes in S1), the controller 300 controls the halogen heater 110 to stop heating the fixing roller 11a (S2). When the central temperature (t1) of the fixing roller 11a is equal to or lower than the predetermined fixing temperature (A1) (No in S1), the controller 300 controls the halogen heater 110 to heat the fixing roller 11a (S3). After the processing in S2 or S3, the control unit 300 determines that the central temperature (t1) of the fixing roller 11a detected by the temperature sensor 80a is a predetermined threshold temperature (A2, for example, 210 ° C.) for determining an abnormal temperature state. It is determined whether it is higher than the above (decision 2: S4). When the central temperature (t1) of the fixing roller 11a is higher than the threshold temperature (A2) (Yes in S4), the control unit 300 stops heating by the halogen heater 110 (S22) and performs a stop process (S23).

  On the other hand, when the central temperature (t1) of the fixing roller 11a is equal to or lower than the threshold temperature (A2) (No in S4), the control unit 300 executes the above-described process of S11 (judgment 7). When the belt temperature (t3) of the first belt 21 detected by the belt temperature sensor 50 is equal to or lower than the third temperature (C1) (No in S11), the control unit 300 jumps to the process in S18 (judgment 10). When the belt temperature (t3) of the first belt 21 is higher than the third temperature (C1) (Yes in S11), the controller 300 determines whether or not the blower fan 70 is operating as “decision 21” in the drawing. A determination is made (S31). When the blower fan 70 is not operating (No in S31), the controller 300 operates the blower fan 70 (S33), and proceeds to the processing of S14. When the blower fan 70 is operating (Yes in S31), the control unit 300 determines whether or not the fixing target temperature (A1) is the normal target temperature (D1) as “determination 22” in the drawing (S38). ). If the fixing target temperature (A1) is the normal target temperature (D1) (Yes in S38), the controller 300 changes the fixing target temperature (A1) to the avoidance target temperature (D2, for example, 180 ° C.) (S32). The process proceeds to S14. When the fixing target temperature (A1) is not the normal target temperature (D1) (No in S38), the control unit 300 proceeds to the processing in S14 without changing the fixing target temperature (A1).

  In the case of the present embodiment, the control unit 300 can change the heating amount of the recording material S by the fixing device 11 by changing the fixing target temperature (A1). The fixing target temperature (A1) of the fixing device 11 varies depending on the type of the recording material S and the like. However, if the belt temperature (t3) of the first belt 21 is higher than the third temperature (C1) even though the blower fan 70 has already been operated, the fixing target temperature (A1) is avoided as emergency processing. Change to target temperature (D2). For example, in the case of the recording material S of the LTR size of the above-mentioned mirror coat platinum, the normal target temperature (D1) is set to 190 ° C., and in this case, the avoidance target temperature (D2) is 180 ° C. By doing so, after operating the blower fan 70, the controller 300 can reduce the amount of heating of the recording material S by the fixing device 11 compared to before the blower fan 70 is operated. The controller 300 can make the heating amount of the recording material S by the fixing device 11 lower than the heating amount when the belt temperature of the first belt 21 is equal to or lower than the third temperature. When the fixing target temperature (A1) is changed, attention must be paid to the set temperature of the avoidance target temperature (D2) because the fixing property and glossiness of the toner on the recording material S change.

  The controller 300 determines whether the belt temperature (t3) of the first belt 21 is higher than the fourth temperature (C2) (decision 8: S14). When the belt temperature (t3) of the first belt 21 is higher than the fourth temperature (C2) (Yes in S14), the control unit 300 stops heating by the halogen heater 110 (S22) and performs a stop process (S23). . On the other hand, when the belt temperature (t3) of the first belt 21 is equal to or lower than the fourth temperature (C2) (No in S14), the controller 300 proceeds to the processing in S18.

  The controller 300 determines whether the belt temperature (t3) of the first belt 21 is equal to or lower than the third temperature (C1) (decision 10: S18). When the belt temperature (t3) of the first belt 21 is higher than the third temperature (C1) (No in S18), the control unit 300 jumps to the processing in S21. When the belt temperature (t3) of the first belt 21 is equal to or lower than the third temperature (C1) (Yes in S18), the control unit 300 proceeds to the process of S34. The control unit 300 determines whether or not the fixing target temperature (A1) is the avoidance target temperature (D2) as “decision 23” in the drawing (S34). When the fixing target temperature (A1) is the avoidance target temperature (D2) (Yes in S34), the control unit 300 changes the fixing target temperature (A1) to the normal target temperature (D1) (S35), and proceeds to the processing of S36. move on. When the fixing target temperature (A1) is not the avoidance target temperature (D2) (No in S34), the control unit 300 proceeds to the processing in S36 without changing the fixing target temperature (A1).

  The control unit 300 executes the above-described processing of S31 (determination 21) as the processing of S36 (S36). When the blower fan 70 is not operating (No in S36), the control unit 300 jumps to the processing in S21. When the blower fan 70 is operating (Yes in S36), the controller 300 stops the end cooling fan 82 (S37), and proceeds to the process of S21.

  The control unit 300 determines whether or not the continuous image forming job has been completed (S21). When the continuous image forming job is completed (Yes in S21), the control unit 300 stops heating by the halogen heater 110 (S22) and performs a stop process (S23). On the other hand, if the continuous image forming job has not been completed (No in S21), the control unit 300 returns to the processing in S1 without performing the stop processing and continues the processing.

  As described above, in the second embodiment, when a plurality of recording materials S are continuously conveyed, the blower fan 70 is operated, and before the recording materials S The amount of heat can be reduced. Further, by lowering the fixing target temperature (A1), the heating amount of the recording material S by the fixing device 11 is reduced, so that the heat amount of the recording material S before entering the recording material cooling device 20 can be reduced. Therefore, also in the second embodiment, the same effect as in the above-described first embodiment that the first belt 21 can be easily maintained at a temperature at which the recording material S can be cooled can be obtained.

[Other embodiments]
In the above-described first embodiment, only the interval between the recording materials S is changed according to the belt temperature of the first belt 21. However, the interval between the recording materials S is changed according to the belt temperature of the first belt 21. And the operation control of the halogen heater 110 may be performed simultaneously. Further, the operation control of the blower fan 70 may be combined.

  The belt temperature of the first belt 21 is not limited to being detected by the belt temperature sensor 50. For example, the number of recording materials S passing through the recording material cooling device 20 continuously from the start of the continuous image forming job is detected, and the belt temperature of the first belt 21 is predicted based on the detected number (information on the temperature of the rotating body). May be. In this case, the number of recording materials S conveyed from the cassette 12 to the conveyance path by the conveyance rollers 13 may be detected without necessarily detecting the number of recording materials S actually passing through the recording material cooling device 20.

  Further, in each of the above-described embodiments, the heat amount reducing process (see FIGS. 6 and 8) is executed in accordance with the execution of the continuous image forming job. However, the present invention is not limited to this. It may be settable. The setting process of the heat quantity reduction method by the user will be described with reference to FIGS. 9 and 10C with reference to FIGS.

  FIG. 9 is a flowchart showing the setting process. The setting process illustrated in FIG. 9 is started by the control unit 300 by operating the operation unit 400, for example, when the user confirms that the recording material S stacked on the stacking unit 60 has adhered to the toner or unevenness in the gloss of the toner image. Is done. As shown in FIG. 9, the control unit 300 displays the initial screen shown in FIG. 10A on the operation unit 400 (S41).

  The operation unit 400 has a display unit 400a that can display various information such as the status of the image forming apparatus 100. In the case of the present embodiment, the display unit 400a can appropriately display various screens such as an “initial screen”, a “type selection screen”, and a “setting screen” (FIGS. 10A to 10C). The display unit 400a is a liquid crystal screen of a touch panel type, and various virtual operators can be displayed on the screen. The display unit 400a is a so-called touch panel type liquid crystal screen that can receive a selection operation of various programs such as a continuous image forming job, an input operation of various data, and the like in accordance with a touch operation on a virtual operator by a user.

  FIG. 10A shows an “initial screen” displayed on the display unit 400a. On the “initial screen”, various information (for example, size) regarding the recording material S stored in the cassette 12 and user definition and various settings such as the conveying direction of the recording material S can be pressed by a user to enable the user to select them. Many virtual operators imitating a button-like switch are displayed. When one of the “setting buttons” 401 is operated, a “type selection screen” shown in FIG. 10B is displayed on the display unit 400a. In the “type selection screen”, the type (here, paper type) of the recording material S such as plain paper, thick paper, thin paper, coated paper, OHP (Over Head Projector) sheet, etc. A “type selection button” 402 is displayed. Further, a “detailed setting button” 403 is displayed. When the “detailed setting button” 403 is operated, a “setting screen” shown in FIG. 10C is displayed on the display unit 400a. On the “setting screen”, a “paper pasting setting” button 405 is displayed in addition to a button 404 displayed to enable the user to select the image density and glossiness.

  Returning to FIG. 9, the control unit 300 determines whether or not the user has operated the “paper pasting setting” button 405 (S42). If the “paper pasting setting” button 405 has not been operated (No in S42), the control unit 300 jumps to the processing in S44. On the other hand, when the “paper pasting setting” button 405 is operated (Yes in S42), the control unit 300 changes the interval (Ts) of the recording materials S to be longer by a predetermined interval (for example, 90 ms) (S43). ). The control unit 300 causes the recording material S to be transported at the changed interval of the recording material S when the continuous image forming job instructed by the user to be executed is executed.

  The controller 300 determines whether the continuous image forming job has been completed (S44). If the continuous image forming job has not been completed (No in S44), the control unit 300 returns to the processing in S42. In this case, the user can further increase the interval (Ts) between the recording materials S by operating the “paper pasting setting” button 405 during continuous image formation. On the other hand, when the continuous image forming job is completed (Yes in S44), the control unit 300 returns the interval (Ts) of the recording materials S to 120 ms (initial value) (S45), and ends the processing.

  In the above-described example, the interval between the recording materials S can be set in accordance with the operation of the “paper sticking setting” button 405. However, the present invention is not limited to this, and the operation control of the halogen heater 110 and the blowing fan 70 described above is performed. You may make it selectively possible. In other words, the user may be able to operate the “paper pasting setting” button 405 to set a different calorie reduction method.

  In each of the embodiments described above, the image forming apparatus 100 of the intermediate transfer system has been described as an example, but the present invention is not limited to this. The embodiments described above are also applicable to a direct transfer type image forming apparatus in which a toner image is directly transferred from the photosensitive drum 1 to a recording material carried and conveyed by a conveyance belt.

8 image forming unit (intermediate transfer belt), 9 image forming unit (roller), 10 image forming unit (secondary transfer roller), 11 fixing unit, 20 cooling unit (recording material cooling unit), 21 unit Rotating body (first belt), 25 rotating body (second belt), 30 cooling means (radiator plate, heat sink), 40 fan (sink cooling fan), 50 temperature detecting means (belt temperature sensor), 70 ... blower means (blower fan), 100 ... image forming apparatus, 300 ... control means (control section), PY (PM, PC, PK) ... image forming section (image forming unit), S ... recording material

Claims (7)

An image forming unit that forms a toner image on a recording material;
A fixing device that heats the recording material on which the toner image is formed by the image forming unit and fixes the toner image on the recording material;
A cooling device having a rotating body that transports the recording material in contact with the recording material on which the toner image has been fixed by the fixing device, and a cooling unit that cools the rotating body,
Control means capable of executing a continuous image forming job for continuously forming images on a plurality of recording materials,
The control unit may be configured to execute the continuous image forming job based on information about the temperature of the rotating body, when the temperature of the rotating body is higher than a predetermined temperature, and when the temperature of the rotating body is equal to or lower than the predetermined temperature. Making the space between the preceding recording material and the next recording material longer and passing through the cooling device,
An image forming apparatus comprising: An image forming unit that forms a toner image on a recording material;
A fixing device that heats the recording material on which the toner image is formed by the image forming unit and fixes the toner image on the recording material;
A cooling device having a rotating body that transports the recording material in contact with the recording material on which the toner image has been fixed by the fixing device, and a cooling unit that cools the rotating body,
Blowing means arranged between the fixing device and the cooling device, capable of blowing air toward the recording material sent from the fixing device to the cooling device,
Control means capable of executing a continuous image forming job for continuously forming images on a plurality of recording materials,
The controller, when executing the continuous image forming job, based on information on the temperature of the rotating body, when the temperature of the rotating body is higher than a predetermined temperature, operates the blowing means,
An image forming apparatus comprising: The control means, during the execution of the continuous image forming job, after operating the air blowing means, to reduce the amount of heating of the recording material by the fixing device than before operating the air blowing means,
The image forming apparatus according to claim 2, wherein: An image forming unit that forms a toner image on a recording material;
A fixing device that heats the recording material on which the toner image is formed by the image forming unit and fixes the toner image on the recording material;
A cooling device having a rotating body that transports the recording material in contact with the recording material on which the toner image has been fixed by the fixing device, and a cooling unit that cools the rotating body,
Control means capable of executing a continuous image forming job for continuously forming images on a plurality of recording materials,
The controller, when executing the continuous image forming job, based on information about the temperature of the rotating body, when the temperature of the rotating body is higher than a predetermined temperature, the heating amount of the recording material by the fixing device, Lower than the heating amount when the temperature of the rotating body is equal to or lower than the predetermined temperature,
An image forming apparatus comprising: Temperature detecting means for detecting the temperature of the rotating body,
The information on the temperature of the rotating body is a temperature detected by the temperature detecting unit.
The image forming apparatus according to claim 1, wherein: The cooling unit has a radiator plate that can radiate heat by contacting the rotating body, and a fan that blows air toward the radiator plate.
The image forming apparatus according to claim 1, wherein: The rotator includes an endless first belt, and an endless second belt that sandwiches and conveys the first belt and the recording material,
The cooling means cools at least one of the first belt and the second belt,
The image forming apparatus according to claim 1, wherein:

Images