JP2021004969A - Image forming apparatus, method for controlling image forming apparatus, and fixing device - Google Patents

Abstract

To provide an image forming apparatus that can appropriately fix a developer image to a medium and satisfactorily hold the developer image fixed to the medium.SOLUTION: The image forming apparatus has an image forming unit that can form a developer image on a medium, a fixing unit that has a heat source generating heat and can fix the developer image formed on the medium to the medium by using the heat, a first vent duct that is adjacent to the fixing unit, and a second vent duct that is provided on the opposite side of the fixing unit when viewed from the first vent duct.SELECTED DRAWING: Figure 1

Description

The present invention relates to an image forming apparatus for forming an image using an electrophotographic method, a control method thereof, and a fixing device used for the image forming apparatus.

The applicant has already provided an electrophotographic image forming apparatus equipped with a cooling fan for cooling the fuser and controlling the on / off control of the cooling fan and the rotation speed of the cooling fan according to the temperature of the fuser. It has been proposed (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2006-171237

By the way, in such an image forming apparatus, it is desirable to keep the fixing device at an appropriate temperature in order to fix the developer image on the medium. On the other hand, we want to suppress the rise in the temperature around the fuser as much as possible.

Therefore, it is desired to provide an image forming apparatus capable of appropriately fixing the developer image on the medium and satisfactorily holding the developer image fixed on the medium.

An image forming apparatus according to an embodiment of the present invention uses heat to form an image forming unit capable of forming a developing agent image on a medium and a developing agent image formed on the medium having a heat source for generating heat. It has a fixing portion that can be fixed, a first ventilation passage adjacent to the fixing portion, and a second ventilation passage provided on the side opposite to the fixing portion when viewed from the first ventilation passage.

The control method of the image forming apparatus according to the embodiment of the present invention is the above-mentioned control method of the image forming apparatus, in which the printing command signal is received from the outside and the condition (1) is to the heat source of the fixing portion. The elapsed time from the interruption of energization is less than the first time, and the condition (2) is that the fixing portion is requested to fix the developer image on both sides of the medium by the print command signal. As (3), the cumulative number of fixed pages in the fixed portion during the second time exceeds the number of the first pages, and as the condition (4), the number of fixed pages in the fixed portion instructed by one print command signal. It includes determining at least one of the fact that the number of pages exceeds the second page, and controlling the operation of the second blower based on the determination.

The fixing device as an embodiment of the present invention includes a heat source that generates heat, and has a fixing portion capable of fixing a developer image formed on the medium to the medium by using heat, and the fixing portion adjacent to the fixing portion. It has a first ventilation path and a second ventilation path provided on the side opposite to the fixing portion when viewed from the first ventilation path.

According to the image forming apparatus and its control method as one embodiment of the present invention, and the fixing apparatus, a first air passage adjacent to a fixing portion including a heat source and a fixing portion sandwiching the first ventilation passage. It has a second vent provided on the opposite side. Therefore, the temperature around the fixing portion can be lowered while keeping the fixing portion at an appropriate temperature. Therefore, the developer image can be appropriately fixed on the medium, and the developer image fixed on the medium can be well maintained.
The effect of the present invention is not limited to this, and any of the effects described below may be used.

It is a schematic diagram which shows the internal structure example of the image forming apparatus which concerns on 1st Embodiment of this invention. It is a perspective view which shows the appearance of the image forming apparatus shown in FIG. It is a side view which shows the appearance of the image forming apparatus shown in FIG. It is a perspective view which shows the inside of the image forming apparatus shown in FIG. It is a side view which shows the inside of the image forming apparatus shown in FIG. It is sectional drawing which shows the fixing apparatus shown in FIG. It is a top view which shows the fixing device shown in FIG. It is a perspective view which shows the fixing device shown in FIG. It is a side view which shows the fixing device shown in FIG. It is a block diagram which shows the control mechanism of the image forming apparatus shown in FIG. It is a flow chart which shows the operation of the image forming apparatus which concerns on 2nd Embodiment of this invention. It is a flow chart which shows the operation of the 1st modification of the 2nd Embodiment of this invention. It is a flow chart which shows the operation of the 2nd modification of the 2nd Embodiment of this invention. It is a flow chart which shows the operation of the 3rd modification of the 2nd Embodiment of this invention. It is a flow chart which shows the operation of the 4th modification of the 2nd Embodiment of this invention. It is a flow chart which shows the operation of the 3rd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following description is a specific example of the present invention, and the present invention is not limited to the following aspects. Further, the present invention is not limited to the arrangement, dimensions, dimensional ratio, etc. of each component shown in each figure. The explanation will be given in the following order.
1. 1. First Embodiment (Aspect in which the first fan and the second fan are always operated)
1.1 Configuration of image forming device 1.2 Control mechanism of image forming device 1.3 Operation of image forming device (A) Basic operation (B) Cooling operation for fixing device 1.4 Effect of image forming device 2. Second embodiment (a mode in which the second fan is selectively operated)
3. 3. First modification of the second embodiment 4. A second modification of the second embodiment 5. A third modification of the second embodiment 6. Fourth modified example of the second embodiment 7. Third Embodiment (Aspect in which the air volume of the second fan is adjusted)
8. Other variants

<1. First Embodiment>
[1.1 Configuration of Image Forming Device 100]
FIG. 1 is a schematic view showing an example of the internal configuration of the image forming apparatus 100 according to the embodiment of the present invention. Further, FIG. 2A is a perspective view showing the appearance of a part of the image forming apparatus 100. Further, FIG. 2B is a side view of the image forming apparatus 100 as viewed from the side. The image forming apparatus 100 corresponds to a specific example of the "image forming apparatus" of the present invention, and corresponds to, for example, a color image and monochrome with respect to a medium (also referred to as a printing medium or transfer material) PM described later, such as paper. It is an electrophotographic printer that can selectively form images. As shown in FIG. 1, this image forming apparatus includes a main body portion 1 and a top cover portion 2 attached to the upper portion of the main body portion 1 so as to be openable and closable. A vent 3 for taking in outside air is provided on the side surface of the main body 1.

As shown in FIG. 1, inside the main body 1, the paper feed unit 10, the medium transfer unit 20, the image forming unit 30, and the transfer unit 40 are arranged in this order from the upstream along the transfer direction of the medium PM. , A fixing device 50, a discharge unit 60, and a control unit 70 are provided. Inside the main body 1, a first fan 81 provided above the image forming unit 30 and a first introduction path 82 for guiding the air from the first fan 81 to the fixing device 50 are further provided. .. Here, the first fan 81 is a specific example corresponding to the "first blower" of the present invention, and the first introduction path 82 is a specific example corresponding to the "first introduction path" of the present invention. is there.

(Paper feeding unit 10)
The paper feed unit 10 includes, for example, a medium tray 11 that stores a plurality of media PMs in a stacked state, a pickup roller 12, a feed roller 13, and a retard roller 14. The medium tray 11 is detachably attached to, for example, the lower part of the main body 1. The pickup roller 12 picks up the medium PMs stacked on the medium tray 11 one by one from the top, and then supplies the picked up medium PMs one by one to the downstream. The feed roller 13 and the retard roller 14 are arranged to face each other, and operate so as to sandwich the medium PM from the pickup roller 12 and supply the medium PM to the downstream medium transport unit 20.

(Media transfer unit 20)
The medium transport unit 20 has, for example, a transport roller pair 21. The medium transport unit 20 is adapted to transport the media PM supplied from the paper feed unit 10 one by one to the image forming unit 30 by the rotation of the transport roller pair 21.

(Image forming unit 30)
The image forming unit 30 has, for example, four image forming units 31 (31K, 31Y, 31M, 31C).

The image forming units 31K, 31Y, 31M, and 31C are mechanisms for forming a toner image to be transferred to the medium PM transported from the medium transport unit 20, respectively. That is, the image forming unit 31K forms a black toner image, the image forming unit 31Y forms a yellow toner image, the image forming unit 31M forms a magenta toner image, and the image forming unit 31C forms a cyan toner image. Is designed to form.

The image forming units 31K, 31Y, 31M, and 31C each have, for example, a photosensitive drum 32, a charging roller 33, a developing roller 34, an exposure device 35, a toner accommodating portion 36, and a supply roller 37, respectively.

The photosensitive drum 32 is a columnar member capable of supporting an electrostatic latent image on a surface (surface layer portion), and is configured by using a photoconductor (for example, an organic photoconductor). Specifically, the photosensitive drum 32 has a conductive support and a photoconducting layer that covers the outer periphery (surface) thereof. The conductive support is made of, for example, a metal pipe made of aluminum. The photoconducting layer has, for example, a structure in which a charge generating layer and a charge transporting layer are laminated in this order. The photosensitive drum 32 is controlled by the control unit 70 and rotates at a predetermined rotation speed in the direction in which the medium PM is conveyed in the conveying direction. Toners of each color are developed on the electrostatic latent image supported on the surface of the photosensitive drum 32.

The charging roller 33 is a charging member that charges the surface of the photosensitive drum 32, and is arranged so as to be in contact with the surface of the photosensitive drum 32.

The developing roller 34 is a member that supports the toner for developing the electrostatic latent image on the surface, and is arranged so as to be in contact with the surface of the photosensitive drum 32.

The exposure device 35 is a device that is arranged so as to face the photosensitive drum 32 and forms an electrostatic latent image on the surface of the photosensitive drum 32 by exposing the surface of the facing photosensitive drum 32. The exposure device 35 has a plurality of light emitting units arranged in the width direction (X-axis direction) orthogonal to the transport direction of the medium PM with respect to the corresponding photosensitive drum 32. Each light emitting unit includes, for example, a light source such as an LED (Light Emitting Diode) that emits irradiation light, and a lens array that forms an image of the irradiation light on the surface of the photosensitive drum 32.

The toner accommodating unit 36 has a container for accommodating toner of each color. Black toner is contained in the toner accommodating portion 36 of the image forming unit 31K, yellow toner is accommodated in the toner accommodating portion 36 of the image forming unit 31Y, and magenta toner is accommodated in the toner accommodating portion 36 of the image forming unit 31M. , Cyan toner is contained in the toner accommodating portion 36 of the image forming unit 31C. The toner is composed of a non-magnetic material containing, for example, a binder resin such as a polyester resin, a charge control agent as an internal additive, a mold release agent and a colorant, and an external additive such as silica or titanium oxide. It is a thing. Of these, the color of the toner image formed by the image forming unit 31 (31K, 31Y, 31M, 31C) can be changed by appropriately selecting the color of the colorant.

The supply roller 37 is a supply member for supplying toner to the developing roller 34, and is arranged so as to be in contact with the surface of the developing roller 34.

(Transfer unit 40)
The transfer unit 40 conveys the medium PM conveyed from the medium transfer unit 20 in the transfer direction (here, the + Z direction), and transfers the toner images formed in the image forming units 31K, 31Y, 31M, and 31C to the medium PM. It is a mechanism that sequentially transfers to the surface of. The transfer unit 40 includes a transport belt 41, a drive roller 42 that rotationally drives the transport belt 41, an idle roller 43 that rotates in response to the drive roller 42, and a plurality of photosensitive drums 32 that sandwich the transport belt 41. It has a plurality of transfer rollers 44 arranged so as to face each other. The drive roller 42 and the idle roller 43 are substantially columnar members that can rotate about a rotation shaft portion extending in the width direction (X-axis direction), respectively.

The transport belt 41 is an endless elastic belt made of a resin material such as a polyimide resin. The transport belt 41 is stretched (stretched) by the drive roller 42 and the idle roller 43. The drive roller 42 is rotationally driven in the direction in which the medium PM is conveyed by the rotational force transmitted from the belt motor based on the control of the control unit 70, and circulates and rotates the transfer belt 41. The idle roller 43 adjusts the tension applied to the transport belt 41 by the urging force of the urging member. The idle roller 43 rotates in the same direction as the drive roller 42.

The plurality of transfer rollers 44 convey the medium PM by rotating in the opposite direction to the image forming units 31K, 31Y, 31M, 31C, and transmit the toner image formed by the image forming units 31K, 31Y, 31M, 31C as a medium. It is a member for electrostatically transferring onto PM. The transfer roller 44 is made of, for example, a foamable semi-conductive elastic rubber material.

(Fixing device 50)
FIG. 3A is a perspective view showing the inside of the image forming apparatus 100, and FIG. 3B is a side view of the inside of the image forming apparatus 100 as viewed from the side. Further, FIG. 4A is a cross-sectional view showing a configuration example of the fixing device 50, and FIG. 4B is a top view showing a state in which the fixing device 50 is viewed from above. Further, FIG. 5A is a perspective view showing the appearance of the fixing device 50, and FIG. 5B is a side view showing the appearance of the fixing device 50. Note that FIG. 4A corresponds to a cross section in the direction of the arrow along the IVA-IVA cutting line shown in FIG. 4B. As shown in FIGS. 1, 2A, 3A, 4A, etc., the uppermost portion 50S of the fixing device 50 constitutes a part of the stacker 100K.

Here, the fixing device 50 is a specific example corresponding to the "fixing device" of the present invention, so that the image forming unit 30 performs a fixing operation of fixing the toner image formed on the medium PM to the medium PM. It has become.

The fixing device 50 has a fixing portion 51. The fixing unit 51 applies heat and pressure to the toner image transferred on the medium PM by the image forming unit 30 and the transfer unit 40, so that the toner image is fixed on the medium PM. As shown in FIG. 4A, the fixing portion 51 includes a fixing roller 52 and a pressurizing roller 53 facing each other across the medium transport path. The fixing roller 52 is controlled by the fixing control unit 890 (described later), and is rotated in the direction in which the medium PM is conveyed in the conveying direction by the rotational force transmitted from the main motor. The pressurizing roller 53 is arranged to face the fixing roller 52 so that a nip portion (pressure contact portion) NP is formed between the pressing roller 53 and the fixing roller 52. The pressurizing roller 53 applies pressure to the toner image on the medium PM passing through the nip portion NP. The pressure roller 53 may have a surface layer made of an elastic material. Further, the fixing roller 52 is configured to include a heater 52H such as a halogen lamp or a nichrome wire inside, and is configured to apply heat to the toner image on the medium PM as a heating member. Further, a temperature sensor 52S such as a thermistor thermometer is provided inside the fixing roller 52 so that the temperature of the fixing roller 52 can be measured. The temperature sensor 52S transmits the temperature information of the fixing roller 52 to the fixing control unit 890 in the control unit 70. The heater 52H is supplied with a bias voltage under the control of the fixing control unit 890, and controls the temperature of the fixing roller 52.

Further, as shown in FIGS. 1 and 4A, the fixing device 50 further has a first ventilation passage AP1 and a second ventilation passage AP2 provided above the fixing portion 51. The first ventilation passage AP1 is provided so as to be adjacent to, for example, the fixing portion 51, and the second ventilation passage AP2 is provided on the side opposite to the fixing portion 51, for example, when viewed from the first ventilation passage AP1. That is, the first ventilation passage AP1 is provided between the fixing portion 51 and the second ventilation passage AP2. Here, the first air passage AP1 and the second air passage AP2 are specific examples corresponding to the "first air passage" and the "second air passage" of the present invention, respectively.

The first air passage AP1 is separated from the fixing portion 51 by a partition wall 54. Further, the second ventilation passage AP2 is separated from the first ventilation passage AP1 by the partition wall 55. Here, the partition wall 54 and the partition wall 55 are specific examples corresponding to the "first wall portion" and the "second wall portion" of the present invention, respectively. The second air passage AP2 is separated from the outside by the uppermost portion 50S having a surface exposed to the outside of the image forming apparatus 100. The uppermost portion 50S constitutes, for example, a part of the stacker 100K of the top cover portion 2. The uppermost portion 50S is, for example, a part of a housing for accommodating the fixing portion 51.

The fixing device 50 is further provided with a first intake port 56 (see FIGS. 1, 3A and 4A) communicating with the first ventilation passage AP1 at a position facing the first fan 81, for example. The first fan 81 is a cooling device that generates air for cooling the fixing device 50. For example, the first fan 81 is driven and controlled by the fan motor control unit 900 (described later) based on a command of the print control unit 800 (described later). , The air inside the main body 1 is taken in and discharged toward the first intake port 56. The air flow F1 generated by the first fan 81 flows into the first ventilation passage AP1 from the first intake port 56 via the first introduction passage 82 inside the main body 1. The air flow F1 flowing from the first intake port 56 into the first air passage AP1 spreads over the entire fixing device 50 in the XZ plane, for example, as shown by the solid arrow in FIG. 4B, in the width direction (X). It spreads in the axial direction) and goes from upstream to downstream along the medium transport direction (Z-axis direction).

Inside the main body 1, a second fan 91 and a second introduction path 92 are further provided on the side of the fixing device 50. Here, the second fan 91 is a specific example corresponding to the "second blower" of the present invention, and the second introduction path 92 is a specific example corresponding to the "second introduction path" of the present invention. is there. The second fan 91 is a cooling device that generates wind for cooling the fixing device 50, and is arranged at a position facing the vent 3 provided in the main body 1. The second fan 91 is driven and controlled by the fan motor control unit 900, for example, based on a command from the print control unit 800, and takes in air taken from the intake port 91A (see FIG. 3A) facing the ventilation port 3 in the second introduction path 92. It is designed to be discharged to. The second introduction path 92 guides the air flow generated by the second fan 91 to the second ventilation path AP2 of the fixing device 50. A second intake port 57 (see FIGS. 5A and 5B) communicating with the second ventilation path AP2 is further provided on the side surface of the fixing device 50, for example, at a position facing the exhaust port of the second introduction path 92. ing. Therefore, the air flow F2 generated by the second fan 91 flows into the second ventilation passage AP2 from the second intake port 57 via the second introduction passage 92. The air flow F2 flowing from the second intake port 57 into the second air passage AP2 spreads throughout the fixing device 50 in the XZ plane, for example, as shown by the broken line arrow in FIG. 4B, in the width direction (X). It spreads in the axial direction) and goes from upstream to downstream along the medium transport direction (Z-axis direction).

Here, the temperature of the air forming the air flow F1 is higher than the temperature of the air forming the air flow F2. The air flow F1 is generated by taking in the air inside the image forming apparatus 100 by the first fan 81, whereas the air flow F2 is generated by taking in air from the outside of the image forming apparatus 100. Because it is a thing. That is, the air inside the image forming apparatus 100 is usually warmer than the outside air due to the heat generated in the image forming unit 30. Further, the air flow F1 reaches the fixing device 50 via the four image forming units 31K, 31Y, 31M, and 31C in sequence after being discharged from the first fan 81, so that the four image forming units 31K, 31Y , 31M, 31C have the function of cooling.

Further, in the image forming apparatus 100, it is desirable that the first length L1 (FIG. 3A) of the first introduction path 82 is longer than the second length L2 (FIG. 3B) of the second introduction path 92. This is to shorten the time that the air flow F2 stays inside the image forming apparatus 100 and prevent the temperature of the air flow F2 from rising. When the first length L1 is, for example, 200 mm, the second length L2 is, for example, 80 mm.

The first fan 81 and the second fan 91 are always operated by the fan motor control unit 900, for example, when the image forming apparatus 100 performs a printing operation.

(Discharge unit 60)
The discharge unit 60 provided downstream of the fixing device 50 has, for example, two sets of transport roller pairs 61 and 62. Further, a stacker 100K is provided on the outside of the top cover portion 2. Each of the transport roller pairs 61 and 62 is adapted to start rotational drive when the medium PM discharged from the fixing device 50 is detected. Therefore, the medium PM on which the toner image is fixed by the fixing device 50 is discharged from the main body 1 to the outside of the top cover 2 by the discharging unit 60, and is sequentially accumulated in the stacker 100K.

[1.2 Control mechanism of image forming apparatus 100]
Next, the control mechanism of the image forming apparatus 100 of the present embodiment will be described with reference to FIG. FIG. 6 is a block diagram showing an example of a control mechanism in the image forming apparatus 100.

As shown in FIG. 6, the image forming apparatus 100 includes a print control unit 800, an I / F control unit 810, a reception memory 820, and an image data editing memory 830 as components of the control unit 70. The image forming apparatus 100 further includes a charging voltage control unit 840, a head drive control unit 850, a developing voltage control unit 860, a transfer voltage control unit 870, a main motor control unit 880, and a fixing control unit that receive commands from the print control unit 800, respectively. A unit 890 and a fan motor control unit 900 are provided.

The print control unit 800 includes, for example, a storage unit 801 including a ROM and RAM, a calculation unit 802 including a microprocessor and the like, and a determination unit 803. For example, an image is obtained by executing a predetermined program. It controls the entire processing operation in the forming apparatus 100. Specifically, the print control unit 800 receives print data and control commands from the I / F control unit 810, and receives a charge voltage control unit 840, a head drive control unit 850, a development voltage control unit 860, and a transfer voltage control unit. The printing operation is performed by supervising the control of the 870, the main motor control unit 880, the fixing control unit 890, and the fan motor control unit 900. The storage unit 801 stores the cumulative number of prints printed in the past. Further, the calculation unit 802 counts the number of prints when the print job is received and the print operation based on the print job is executed. Further, the discriminating unit 803 is adapted to determine the necessity of on / off control of the second fan 91 in consideration of various printing conditions.

The I / F control unit 810 receives print data and control commands from an external device such as a personal computer (PC), or transmits a signal relating to the state of the image forming device 100.

The reception memory 820 temporarily stores print data from an external device such as a PC via the I / F control unit 810.

The image data editing memory 830 receives the print data stored in the reception memory 820, and stores the image data in which the print data is edited.

The charging voltage control unit 840 applies a charging voltage to each charging roller 33 according to the instruction of the printing control unit 800, and controls the surface of each photosensitive drum 32 to be charged.

The head drive control unit 850 controls the exposure operation by each exposure device 35 according to the image data stored in the image data editing memory 830.

The development voltage control unit 860 applies a development voltage to each development roller 34 according to the instruction of the print control unit 800, and controls the toner to be developed on the electrostatic latent image formed on the surface of each photosensitive drum 32. It is something to do.

The transfer voltage control unit 870 applies a transfer voltage to each transfer roller 44 according to the instruction of the print control unit 800, and controls the toner image to be transferred to the recording medium PM.

The main motor control unit 880 controls the drive of the drive motors 881-884 according to the instruction of the print control unit 800. The drive motors 888 to 884 are adapted to rotate and drive the four photosensitive drums 32, the four charging rollers 33, and the four developing rollers 34, respectively.

The fixing control unit 890 controls the fixing operation of the fixing device 50 according to the instruction of the printing control unit 800. Specifically, the voltage applied to the heater 52H is controlled. The fixing control unit 890 controls on / off of the voltage applied to the heater 52H based on the temperature of the fixing roller 52 measured by the temperature sensor 52S. The fixing control unit 890 also controls the operation of the fixing motor 891 that drives the rotation of the fixing roller 52, for example.

The fan motor control unit 900 controls the operation of the first fan 81 and the second fan 91 provided in the image forming apparatus 100 according to the instruction of the print control unit 800.

[1.3 Operation of image forming apparatus 100]
(A. Basic operation)
In the image forming apparatus 100, the toner image is transferred to the medium PM as follows.

When print image data, a print command, or the like is input to the print control unit 800 from an external device such as a PC to the activated image forming device 100 via the I / F control unit 810, the print control unit 800 performs the print image data The print operation of the print image data according to the print command is started.

Specifically, for example, based on the print processing program stored in the storage unit 801, the calculation unit 802 instructs the print operation, and the drive motors 883 to 884 are driven. As a result, for example, the media PM placed on the medium tray 11 of the paper feed unit 10 is picked up one by one from the top by a pickup roller 12 or the like and supplied to the medium transport unit 20. In the medium transport unit 20, the transport roller pair 21 starts rotational drive. As a result, the medium PM is conveyed toward the image forming unit 30 downstream while the skew of the medium PM is corrected by the transfer roller pair 21. In the image forming unit 30, a toner image is formed as follows, and the toner image is transferred onto the medium PM.

In the image forming unit 30, the toner image of each color is formed by the following electrophotographic process according to the printing command of the printing control unit 800. Specifically, the print control unit 800 rotates the drive motors 888 to 884 to rotate the photosensitive drum 32 in each image forming unit 31 in a predetermined direction at a constant speed. Along with this, the charging roller 33, the developing roller 34, and the supply roller 37 in each image forming unit 31 (31K, 31Y, 31M, 31C) also start rotating in a predetermined direction.

On the other hand, the print control unit 800 applies a predetermined charging voltage to the charging rollers 33 of each image forming unit 31 (31K, 31Y, 31M, 31C) to uniformly charge the surfaces of the corresponding photosensitive drums 32. .. Next, the print control unit 800 activates each exposure device 35 to irradiate each photosensitive drum 32 with light corresponding to the color component of the printed image based on the image signal. As a result, an electrostatic latent image is formed on the surface of each photosensitive drum 32.

The print control unit 800 further commands the fixing control unit 890 to energize the fixing device 50 and activates the heater 52H and the temperature sensor 52S. At the same time, the print control unit 800 commands the fan motor control unit 900 to start the blowing operation of the first fan 81 and the second fan 91. The blowing operation of the first fan 81 and the second fan 91 continues until, for example, the power of the image forming apparatus 100 is turned off.

In the image forming unit 31 (31K, 31Y, 31M, 31C), a predetermined developing voltage is applied to the developing rollers 34 of each color under the control of the print control unit 800. Further, a predetermined supply voltage is applied to each supply roller 37 based on the control of the print control unit 800. As a result, each color toner is supplied to each developing roller 34 via each supply roller 37, and is supported on the surface of each developing roller 34. Each developing roller 34 adheres toner to the electrostatic latent image formed on each photosensitive drum 32, and forms a visualized toner image of each color.

Further, based on the control of the print control unit 800, a predetermined voltage is applied to each transfer roller 44 in the transfer unit 40, and an electric field is generated between each photosensitive drum 32 and each transfer roller 44. When the medium PM runs between the photosensitive drum 32 and the transfer roller 44 in that state, the visualized toner images of each color formed on the photosensitive drum 32 are sequentially transferred onto the medium PM.

After that, the toner image transferred onto the medium PM is fixed to the medium PM by applying heat and pressure to the nip portion NP of the fixing unit 51 under the control of the print control unit 800. At that time, as described above, for example, the temperature of the fixing roller 52 is detected by the temperature sensor 52S, and the temperature of the heater 52H based on the print control unit 800 is adjusted so that the nip unit NP comes into contact with the medium PM at an appropriate temperature. Will be done.

The medium PM on which the toner image is fixed is discharged from the fixing device 50 to the outside of the main body 1 and the top cover 2 via the discharge unit 60, and is accumulated in the stacker 100K.

(B. Cooling operation for fixing device 50)
Next, the cooling operation for the fixing device 50 in the image forming device 100 of the present embodiment will be described.

As described above, the first fan 81 and the second fan 91 start the blowing operation based on the control of the fan motor control unit 900 commanded by the print control unit 800. Due to the blowing operation of the first fan 81, the air flow F1 passes through the first ventilation passage AP1 inside the fixing device 50 via the first introduction passage 82. Further, due to the blowing operation of the second fan 91, the air flow F2 passes through the second ventilation passage AP2 inside the fixing device 50 via the second introduction passage 92. Here, the temperature of the air flow F1 generated by the air inside the image forming apparatus 100 is higher than the temperature of the air flow F2 generated by the outside air. Therefore, the uppermost portion 50S is sufficiently cooled by the air flow F2 passing in the vicinity thereof, while the fixing portion 51 is appropriately cooled by the air flow F1 passing in the vicinity thereof. The first fan 81 is driven so as to generate, for example, an air flow F1 having a wind pressure (static pressure) of 50 Pa and an air volume of 0.1 m ³ / min. On the other hand, the second fan 91 is driven to generate an air flow F2 having a wind pressure (static pressure) of 100 Pa and an air volume of 0.2 m ³ / min., Which is larger than the energy of the air flow F1 generated by the first fan 81. To do. This is to avoid warming the air taken into the image forming apparatus 100 from the outside of the image forming apparatus 100 by the second fan 91 as much as possible.

[1.4 Effect of image forming apparatus 100]
As described above, in the image forming apparatus 100 of the first embodiment, the first ventilation passage AP1 adjacent to the fixing portion 51 having the heater 52H and the fixing portion 51 as viewed from the first ventilation passage AP1 are opposite to each other. It has a second air passage AP2 provided on the side. Therefore, by appropriately adjusting the temperature, air volume, wind pressure, etc. of the air flow F1 passing through the first ventilation path AP1 and the temperature, air volume, wind pressure, etc. of the air flow F2 passing through the second ventilation path AP2. The temperature around the fixing portion 51 can be lowered while keeping the fixing roller 52, the pressure roller 53, and the like in the fixing portion 51 at appropriate temperatures. If heat is transferred from the fixing portion 51 to the surrounding area, for example, the stacker 100K, the developer images fixed on the plurality of media PMs laminated on the stacker 100K may be remelted by the heat. I am concerned. In that respect, according to the image forming apparatus 100 of the first embodiment, the toner image is appropriately fixed to the medium PM, and the toner image fixed to the medium PM accumulated in the stacker 100K is not remelted. Can be held in.

In particular, in the first embodiment, since the first length L1 of the first introduction path 82 is made longer than the second length L2 of the second introduction path 92, it passes through the first air passage AP1. The temperature difference between the temperature of the air flow F1 and the temperature of the air flow F2 passing through the second air passage AP2 can be increased. Therefore, the temperature of the uppermost portion 50S of the fixing device 50 can be further lowered while keeping the fixing roller 52 and the pressure roller 53 in the fixing portion 51 at appropriate temperatures.

<2. Second Embodiment>
In the first embodiment, both the first fan 81 and the second fan 91 are always operated until the image forming apparatus 100 is turned off after the fixing device 50 is energized. On the other hand, in the second embodiment, when the fixing operation is performed, the first fan 81 is always operated, while the second fan 91 is selectively operated according to the printing condition (fixing condition). ..

In the second embodiment, the print control unit 800 starts and stops the second fan 91 according to the elapsed time T after the energization of the heater 52H of the fixing unit 51 is cut off. There is. The elapsed time T can be, for example, about 30 minutes.

Specifically, in the second embodiment, the fan motor control unit 900 executes and stops the second fan 91 according to the procedure shown in FIG. 7. FIG. 7 is a flow chart showing a procedure such as operation of the second fan 91 in the second embodiment.

In the activated state of the image forming apparatus 100, the fan motor control unit 900 first determines whether or not the print control unit 800 has received a print command from the I / F control unit 810 (step S101). If the print command has not been received (step S101N), step S101 is repeated until it is received.

When the print control unit 800 receives the print command (step S101Y), the fan motor control unit 900 activates the first fan 81 (step S102).

Next, the fan motor control unit 900 determines whether or not a predetermined elapsed time T has elapsed since the previous printing operation was completed and, more specifically, the energization of the fixing device 50 was cut off (). Step S103). Here, when the fan motor control unit 900 determines that the predetermined elapsed time T has not elapsed (step S103N), the fan motor control unit 900 activates the second fan 91 (step S104) and proceeds to step S105. On the other hand, when it is determined that the predetermined elapsed time T has elapsed (step S103Y), the second fan 91 is not activated, and the printing operation is started as it is according to the printing command (step S105).

After the start of the print operation, the print control unit 800 determines whether or not all the print operations corresponding to the print jobs have been completed (step S106). If all the printing operations have not been completed (step S105N), step S105 is repeated until the printing operation is completed.

When it is determined that all the printing operations have been completed (step S106Y), the print control unit 800 commands the fixing control unit 890 to cut off the energization of the fixing device 50 (step S107).

After that, the print control unit 800 commands the fan motor control unit 900 to stop the blowing operation of the first fan 81 and the second fan 91 (step S108), and ends (end).

As described above, according to the second embodiment, it is determined whether or not a predetermined elapsed time T has elapsed since the energization of the fixing device 50 was cut off (step S103) until the elapsed time T elapses. Since the blowing operation of both the first fan 81 and the second fan 91 is continued, it is possible to suppress the transfer of the heat of the heater 52H and its surroundings accompanying the fixing operation to the uppermost portion 50S. On the other hand, when the elapsed time T has elapsed in step S103, the blowing operation of the second fan 91 is not performed, so that it is possible to avoid excessive cooling of the fixing device 50 and reduce the power consumption. it can. That is, in the second embodiment, when the fixing operation is performed, the first fan 81 is always operated, while the second fan 91 is selectively operated according to the printing condition (fixing condition). The fixing device 50 can be cooled efficiently.

<3. First variant of the second embodiment>
In the second embodiment described above, the second fan 91 is turned on and off depending on whether or not the elapsed time T has elapsed. On the other hand, in the first modification of the second embodiment, the second fan 91 is turned on and off depending on whether or not double-sided printing is performed.

In the first modification of the second embodiment, the print control unit 800 operates the second fan 91 when forming and fixing the toner images on both sides of the medium PM.

Specifically, in the first modification of the second embodiment, the fan motor control unit 900 executes and stops the second fan 91 according to the procedure shown in FIG. FIG. 8 is a flow chart showing a procedure such as the operation of the second fan 91 in the first modification of the second embodiment.

In the first modification of the second embodiment, the second fan follows the same procedure as in the second embodiment, except that step S110 is performed instead of step S103 shown in FIG. The operation of 91 and the like are executed. That is, after starting the first fan 81 in step S102, the print control unit 800 determines whether the printing operation based on the print job is double-sided printing (step S110). When the printing operation is double-sided printing (step S110Y), the second fan 91 is started (step S104). On the other hand, when the printing operation is single-sided printing (step S110N), the second fan 91 is not activated and the process proceeds to step S105 as it is. The procedure other than that is the same as in FIG.

In the first modification of the second embodiment, when performing double-sided printing in which heat tends to be trapped inside the fixing device 50, the second fan 91 is operated to supply the air flow F2 to the second ventilation path AP2. I try to do it. Therefore, it is possible to suppress the transfer of heat of the heater 52H and its surroundings accompanying the fixing operation to the uppermost portion 50S. On the other hand, since the blowing operation of the second fan 91 is stopped during single-sided printing, it is possible to avoid excessive cooling of the fixing device 50 and reduce power consumption.

<4. Second variant of the second embodiment>
In the second embodiment described above, the second fan 91 is turned on and off depending on whether or not the elapsed time T has elapsed. On the other hand, in the second modification of the second embodiment, the cumulative number of printed pages (that is, the number of fixed pages N) within the predetermined time immediately before the printing operation, for example, 60 minutes immediately before, is a predetermined number, for example, 200. The second fan 91 is turned on and off depending on whether or not the page is exceeded.

In the second modification of the second embodiment, the print control unit 800 sets the cumulative number of printed pages N within the predetermined time to 200 according to the cumulative number of fixed pages N within the predetermined time in the fixing unit 51. When it exceeds, the second fan 91 is operated.

Specifically, in the second modification of the second embodiment, the fan motor control unit 900 executes and stops the second fan 91 according to the procedure shown in FIG. FIG. 9 is a flow chart showing a procedure such as operation of the second fan 91 in the second modification of the second embodiment.

In the second modification of the second embodiment, the second fan follows the same procedure as in the second embodiment, except that step S111 is performed instead of step S103 shown in FIG. The operation of 91 and the like are executed. That is, after starting the first fan 81 in step S102, the print control unit 800 determines whether or not the cumulative number of fixed pages N in the fixing unit 51 within a predetermined time exceeds 200 (step S111). When the cumulative number of fixed pages N exceeds 200 (step S111Y), the second fan 91 is started (step S104). On the other hand, when the cumulative number of fixed pages N is 200 or less (step S111N), the second fan 91 is not activated, and the process proceeds to step S105 as it is. The procedure other than that is the same as in FIG.

In the second modification of the second embodiment, for example, the cumulative number of printed pages N exceeds a predetermined value (for example, 200) in the immediately preceding 60 minutes, and a considerable amount of heat is already stored inside the fixing device 50. When the printing operation is further executed in the state, the second fan 91 is operated to supply the air flow F2 to the second air passage AP2. Therefore, it is possible to suppress the transfer of heat of the heater 52H and its surroundings accompanying the fixing operation to the uppermost portion 50S. On the other hand, when the cumulative number of printed pages N is equal to or less than a predetermined value (for example, 200) in the immediately preceding 60 minutes, the blowing operation of the second fan 91 is stopped, so that the fixing device 50 is not excessively cooled. Not only can it be avoided, but power consumption can be reduced.

<5. Third variant of the second embodiment>
In the second embodiment described above, the second fan 91 is turned on and off depending on whether or not the elapsed time T has elapsed. On the other hand, in the third modification of the second embodiment, the second fan 91 is turned on and off depending on whether or not the number of print pages based on one print instruction exceeds a predetermined number.

In the third modification of the second embodiment, the number of fixed pages P in the fixing unit 51 instructed by one printing command (print command signal) received by the print control unit 800 from the I / F control unit 810. The second fan 91 is operated, for example, when the number of fixed pages P exceeds 100 pages.

Specifically, in the third modification of the second embodiment, the fan motor control unit 900 executes and stops the second fan 91 according to the procedure shown in FIG. FIG. 10 is a flow chart showing a procedure such as operation of the second fan 91 in the third modification of the second embodiment.

In the third modification of the second embodiment, the second fan follows the same procedure as in the second embodiment, except that step S112 is performed instead of step S103 shown in FIG. The operation of 91 and the like are executed. That is, after starting the first fan 81 in step S102, the print control unit 800 determines whether or not the number of fixed pages P in the fixing unit 51 instructed by one print command (print command signal) exceeds 100. (Step S112). When the number of fixed pages P exceeds 100 (step S112Y), the second fan 91 is started (step S104). On the other hand, when the number of fixed pages P is 100 or less (step S112N), the second fan 91 is not activated, and the process proceeds to step S105 as it is. The procedure other than that is the same as in FIG.

In the third modification of the second embodiment, the number of fixed pages P in the fixing unit 51 instructed by one printing command (print command signal) exceeds a predetermined value, for example, 100, and the fixing device 50 When the printing operation is further executed in a state where a considerable amount of heat is already stored inside, the second fan 91 is operated to supply the air flow F2 to the second ventilation passage AP2. Therefore, it is possible to suppress the transfer of heat of the heater 52H and its surroundings accompanying the fixing operation to the uppermost portion 50S. On the other hand, when the number of fixed pages P in the fixing unit 51 instructed by one printing command (print command signal) is equal to or less than a predetermined value (for example, 100), the blowing operation of the second fan 91 is stopped. Therefore, it is possible to avoid excessive cooling of the fixing device 50 and reduce power consumption.

<6. Fourth variant of the second embodiment>
In the first to third modifications of the second embodiment and the second embodiment, the second fan 91 is operated according to different judgment criteria at the stage when the first fan 81 is started after receiving the print command. I try to decide whether or not to let it. However, it is determined whether or not to operate the second fan 91 by arbitrarily combining the determination criteria of steps S103 and steps S110 to 112 shown in the first to third modifications of the second embodiment. May be good. That is, for example, the elapsed time T after the energization of the fixing unit 51 to the heater 52H is cut off is less than a predetermined time (for example, 30 minutes) as the condition (1), and the fixing unit 51 is subjected to the condition (2). On the other hand, the request for fixing the toner image on both sides of the medium PM is made by the print command signal, and as the condition (3), the cumulative number of fixed pages N in the second time (for example, 60 minutes) in the fixing unit 51 is a predetermined page. The number (for example, 200 pages) is exceeded, and the number of fixed pages P in the fixing unit 51 indicated by one print command signal as the condition (4) exceeds a predetermined number of pages (for example, 100 pages). , The blowing operation of the second fan 91 may be turned on when at least one of the conditions is satisfied.

Specifically, in the fourth modification of the second embodiment, the fan motor control unit 900 executes and stops the second fan 91 according to the procedure shown in FIG. FIG. 11 is a flow chart showing a procedure such as the operation of the second fan 91 in the fourth modification of the second embodiment.

In the activated state of the image forming apparatus 100, first, the fan motor control unit 900 determines whether or not the print control unit 800 has received the print command from the I / F control unit 810 (step S101). If the print command has not been received (step S101N), step S101 is repeated until it is received.

When the print control unit 800 receives the print command (step S101Y), the fan motor control unit 900 activates the first fan 81 (step S102).

Next, the fan motor control unit 900 determines whether or not one or more of the above conditions (1) to (4) is satisfied (step S201). Here, when the fan motor control unit 900 determines that none of the above conditions (1) to (4) is satisfied (step S201N), the fan motor control unit 900 starts the printing operation as it is according to the printing command (step S105). ..

On the other hand, when it is determined that one or more of the above conditions (1) to (4) are satisfied (step S201Y), the second fan 91 is started (step S203), and then the printing operation is started according to the printing command. (Step S105).

After the start of the print operation, the print control unit 800 determines whether or not all the print operations corresponding to the print jobs have been completed (step S106). When all the printing operations have not been completed (step S106N), steps S201 to S106 are repeated until the printing operations are completed.

When it is determined that all the printing operations have been completed (step S106Y), the print control unit 800 commands the fixing control unit 890 to cut off the energization of the fixing device 50 (step S107).

After that, the print control unit 800 commands the fan motor control unit 900 to stop the blowing operation of the first fan 81 and the second fan 91 (step S108), and ends (end).

As described above, according to the fourth modification of the second embodiment, the blowing operation of the second fan 91 is selectively performed according to the printing conditions. Therefore, it is possible to suppress the transfer of heat of the heater 52H and its surroundings accompanying the fixing operation to the uppermost portion 50S. Further, since the blowing operation of the second fan 91 is appropriately and selectively performed according to the printing conditions, it is possible to avoid excessive cooling of the fixing device 50 and reduce the power consumption.

<7. Third Embodiment>
In the third embodiment, under the control of the fan motor control unit 900, the second fan 91 is operated at the first rotation speed R1 for generating the first air flow amount Q1 and from the first air flow amount Q1. The operation at the second rotation speed R2 (> R1) that generates the second air flow amount Q2 (> Q1), which is also large, is selectively executed.

Further, in the third embodiment, the fan motor control unit 900 has a condition (1) in which the elapsed time T after the energization of the fixing unit 51 to the heater 52H is cut off is less than a predetermined time (for example, 30 minutes). The condition (2) is that the fixing unit 51 is requested to fix the toner image on both sides of the medium PM by the print command signal, and the condition (3) is the second time (for example, for example) in the fixing unit 51. The cumulative number of fixed pages N within (60 minutes) exceeds a predetermined number of pages (for example, 200 pages), and as a condition (4), the number of fixed pages P in the fixed portion 51 instructed by one print command signal is predetermined. It is determined that the number of pages (for example, 100 pages) is exceeded. Then, when only one of the conditions (1) to (4) is satisfied, the second fan 91 is operated at the first rotation speed R1 to satisfy two or more of the conditions (1) to (4). Occasionally, the second fan 91 is operated at the second rotation speed R2, and the operation of the second fan 91 is stopped when all of the conditions (1) to (4) are not satisfied.

Specifically, in the third embodiment, the fan motor control unit 900 executes and stops the second fan 91 according to the procedure shown in FIG. FIG. 12 is a flow chart showing a procedure such as the operation of the second fan 91 in the third embodiment.

In the activated state of the image forming apparatus 100, the fan motor control unit 900 first determines whether or not the print control unit 800 has received a print command from the I / F control unit 810 (step S101). If the print command has not been received (step S101N), step S101 is repeated until it is received.

When the print control unit 800 receives the print command (step S101Y), the fan motor control unit 900 activates the first fan 81 (step S102).

Next, the fan motor control unit 900 determines whether or not one or more of the above conditions (1) to (4) is satisfied (step S201). Here, when the fan motor control unit 900 determines that none of the above conditions (1) to (4) is satisfied (step S201N), the fan motor control unit 900 starts the printing operation as it is according to the printing command (step S105). ..

On the other hand, when it is determined that one or more of the above conditions (1) to (4) are satisfied (step S201Y), whether or not two or more of the above conditions (1) to (4) are satisfied is satisfied. Determine (step S203). Here, when the fan motor control unit 900 determines that two or more of the above conditions (1) to (4) are satisfied (step S203Y), the fan motor control unit 900 operates the second fan 91 at the second rotation speed R2. , The air flow F2 of the second air flow rate Q2 is generated (step S204). On the other hand, when the fan motor control unit 900 determines that two or more of the above conditions (1) to (4) are not satisfied (step S203N), that is, the above conditions (1) to (4). When it is determined that only one of the above is satisfied, the second fan 91 is operated at the first rotation speed R1 to generate the air flow F2 having the first air flow rate Q1 (step S205).

After the start of the print operation, the print control unit 800 determines whether or not all the print operations corresponding to the print jobs have been completed (step S106). When all the printing operations have not been completed (step S106N), steps S201 to S106 are repeated until the printing operations are completed.

When it is determined that all the printing operations have been completed (step S106Y), the print control unit 800 commands the fixing control unit 890 to cut off the energization of the fixing device 50 (step S107).

After that, the print control unit 800 commands the fan motor control unit 900 to stop the blowing operation of the first fan 81 and the second fan 91 (step S108), and ends (end).

As described above, according to the third embodiment, the rotation speed of the second fan 91 is selected according to the printing conditions, and the amount of air blown is adjusted. Therefore, it is possible to suppress the transfer of heat of the heater 52H and its surroundings accompanying the fixing operation to the uppermost portion 50S. Further, by appropriately adjusting the rotation speed of the second fan 91 according to the printing conditions, it is possible to avoid excessive cooling of the fixing device 50 and reduce power consumption.

<8. Other variants>
Although the present invention has been described above with reference to some embodiments and modifications, the present invention is not limited to the above embodiments and can be modified in various ways. For example, in the above-described embodiment and the like, an image forming apparatus capable of forming a color image using four colors of toner has been described, but the present invention is not limited to this, and for example, a color image of five or more colors is formed. It may be an image forming apparatus.

Further, in the above-described embodiment and the like, two ventilation paths are provided in the vicinity of the fixing portion, but three or more ventilation paths may be provided. In that case, the farther away from the fixing portion, the lower the temperature of the air flow may pass. Further, although one blower (fan) is provided for one air passage, the present invention is not limited to this, and for example, a plurality of blowers (fans) are provided for one air passage. You may.

Further, in the above embodiment, the LED head using the light emitting diode as the light source is used as the exposure device, but for example, an exposure device using a laser element or the like as the light source may be used.

Further, in the above-described embodiment, a printer having a printing function has been described as a specific example of the "image forming apparatus" in the present invention, but the present invention is not limited to this. That is, in addition to such a printing function, the present invention can be applied to, for example, an image forming apparatus that functions as a multifunction device having a scanning function and a fax function.

100 ... image forming device, 100K ... stacker, 1 ... main body, 2 ... top cover, 3 ... vent, 10 ... paper feed, 11 ... medium tray, 12 ... pickup roller, 13 ... feed roller, 14 ... retard Roller, 20 ... Medium transport section, 21 ... Transport roller pair, 30 ... Image forming section, 31 (31K, 31Y, 31M, 31C) ... Image forming unit, 32 ... Photosensitive drum, 33 ... Charging roller, 34 ... Developing roller, 35 ... Exposure device, 36 ... Toner storage section, 37 ... Supply roller, 40 ... Transfer section, 41 ... Conveying belt, 42 ... Drive roller, 43 ... Idle roller, 44 ... Transfer roller, 50 ... Fixing device, 51 ... Fixing section , 52 ... Fixing roller, 52H ... Heater, 52S ... Temperature sensor, 53 ... Pressurizing roller, 54, 55 ... Partition, 56 ... First intake port, 57 ... Second intake port, 60 ... Discharge unit, 70 ... Control unit , 81 ... 1st fan, 82 ... 1st introduction path, 91 ... 2nd fan, 92 ... 2nd introduction path, 800 ... print control unit, 801 ... storage unit, 802 ... arithmetic unit, 803 ... discrimination unit, 810 ... I / F control unit, 820 ... Receive memory, 830 ... Image data editing memory, 840 ... Charge voltage control unit, 850 ... Head drive control unit, 860 ... Development voltage control unit, 870 ... Transfer voltage control unit, 880 ... Main motor Control unit, 890 ... Fixing control unit, 900 ... Fan motor control unit, AP1 ... 1st air passage, AP2 ... 2nd air passage, NP ... Nip part.

Claims (19)

An image forming part capable of forming a developer image on a medium,
A fixing portion having a heat source that generates heat and capable of fixing the developer image formed on the medium to the medium by using the heat.
The first air passage adjacent to the fixing portion and
An image forming apparatus having a second air passage provided on the side opposite to the fixing portion when viewed from the first air passage. A first blower that sends first air to the first ventilation path,
The image forming apparatus according to claim 1, further comprising a second blower for sending a second air to the second ventilation path. The image forming apparatus according to claim 2, wherein the temperature of the first air passing through the first ventilation passage is higher than the temperature of the second air passing through the second ventilation passage. Further provided with a control unit for controlling the operation of the heat source, the first blower and the second blower.
The control unit
The image forming according to claim 2 or 3, wherein the second blower is started and stopped according to the elapsed time from the interruption of the energization of the fixing portion to the heat source. apparatus. Further provided with a control unit for controlling the operation of the heat source, the first blower and the second blower.
The image forming according to claim 2 or 3, wherein the control unit operates the second blower when the fixing unit fixes the developer image on both surfaces of the medium. apparatus. Further provided with a control unit for controlling the operation of the heat source, the first blower and the second blower.
The image forming apparatus according to claim 2 or 3, wherein the control unit operates the second blower device according to the cumulative number of fixed pages in the fixing unit within a predetermined time. A control unit that receives a print command signal from the outside and controls the operation of the heat source, the first blower, and the second blower is further provided.
The second or third aspect of the present invention, wherein the control unit operates the second blower according to the number of fixed pages in the fixing unit instructed by one printing command signal. Image forming device. The second blower is operated at a first rotation speed that generates a first blower amount and at a second rotation speed that generates a second blower amount larger than the first blower amount. The image forming apparatus according to any one of claims 2 to 7, wherein operation can be selectively performed. A control unit that receives a print command signal from the outside and controls the operation of the heat source, the first blower, and the second blower is further provided.
The control unit determines each of a plurality of conditions related to the printing operation, and determines each of the plurality of conditions.
When only one of the plurality of conditions is satisfied, the second blower is operated at the first rotation speed.
When two or more of the plurality of conditions are satisfied, the second blower is operated at the second rotation speed.
The image forming apparatus according to claim 8, wherein the operation of the second blower device is stopped when all of the plurality of conditions are not satisfied. A control unit that receives a print command signal from the outside and controls the operation of the heat source, the first blower, and the second blower is further provided.
The control unit
The condition (1) is that the elapsed time from the interruption of the energization of the fixing portion to the heat source is less than the first time, and the condition (2) is that the developing agent is applied to both sides of the medium with respect to the fixing portion. The request for fixing the image is made by the print command signal, and as the condition (3), the cumulative number of fixed pages in the fixing portion within the second time exceeds the number of the first pages, and the condition (4). ), It is determined that the number of fixed pages in the fixed portion indicated by one printing command signal exceeds the number of second pages.
When only one of the conditions (1) to (4) is satisfied, the second blower is operated at the first rotation speed.
When two or more of the conditions (1) to (4) are satisfied, the second blower is operated at the second rotation speed.
The image forming apparatus according to claim 8, wherein the operation of the second blower device is stopped when all of the conditions (1) to (4) are not satisfied. A fixing device having the fixing portion, the first ventilation path, and the second ventilation path,
The image according to any one of claims 2 to 10, further comprising a first introduction path provided in the image forming unit and connecting the first blower device and the first ventilation path. Forming device. The image forming apparatus according to claim 11, further comprising a second introduction path connecting the second blower device and the second ventilation path. The image forming apparatus according to claim 12, wherein the first length of the first introduction path is longer than the second length of the second introduction path. Further equipped with a housing having an exposed surface,
The image forming apparatus according to any one of claims 1 to 13, wherein the second ventilation path is separated from the outside by a part of the housing. The image forming apparatus according to claim 14, wherein the surface of the housing constitutes a part of a stacker in which the medium is stored. A fixing device having the fixing portion, the first ventilation path, and the second ventilation path is further provided.
The fixing device is
A first wall portion that separates the fixing portion and the second ventilation path,
The image forming apparatus according to any one of claims 1 to 15, further comprising a second wall portion separating the second air passage and the first air passage. An image forming portion capable of forming a developing agent image on a medium, and a fixing portion having a heat source for generating heat and capable of fixing the developing agent image formed on the medium to the medium using the heat. , A first air passage adjacent to the fixing portion, a second air passage provided on the side opposite to the fixing portion when viewed from the first air passage, and a first air passage in the first air passage. A control method for an image forming apparatus including a first blower that sends air and a second blower that sends second air to the second air passage.
Receiving a print command signal from the outside
The condition (1) is that the elapsed time from the interruption of the energization of the fixing portion to the heat source is less than the first time, and the condition (2) is that the developing agent is applied to both sides of the medium with respect to the fixing portion. The request for fixing the image is made by the print command signal, and as the condition (3), the cumulative number of fixed pages in the fixing portion within the second time exceeds the number of the first pages, and the condition (4). ), At least one of the fact that the number of fixed pages in the fixing portion indicated by one printing command signal exceeds the number of second pages is determined, and based on the determination, the second How to control an image forming device, including controlling the operation of the blower. All of the conditions (1) to (4) are judged, and when only one of the conditions (1) to (4) is satisfied, the second blower is operated at the first rotation speed. When two or more of the conditions (1) to (4) are satisfied, the second blower is operated at a second rotation speed higher than the first rotation speed, and the conditions (1) to (4) The control method of the image forming apparatus according to claim 17, wherein the operation of the second blower is stopped when all of 4) are not satisfied. A fixing portion having a heat source that generates heat and capable of fixing a developer image formed on the medium to the medium by using the heat.
The first air passage adjacent to the fixing portion and
A fixing device having a second ventilation path provided on the side opposite to the fixing portion when viewed from the first ventilation path.

Images