JP2003076253A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus which has its apparatus main body made small-sized and is highly reliable by deterring foreign matter from entering the device main body and effectively cooling a cooled object unit without spoiling the outward appearance of the apparatus main body. SOLUTION: The apparatus is equipped with an air intake 18 which is formed in the flank of a front cover 24 and takes outside air in the device main body, an air outlet 19 which is bored in a left cover 28 and discharges the air in the apparatus main body 23 to outside the apparatus main body, and an axial flow fan 15 which is provided on the straight line connecting the air intake 18 and air outlet 19 and guides the air in the apparatus main body to the air outlet 19 to discharge it to outside the apparatus main body; and the cooled object unit is arranged almost on the straight line connecting the air intake 18 and air outlet 19 and a wind setting means which sets either the direction nor the amount of wind in the apparatus main body is provided between the air intake 18 and cooled object unit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus having a function of forming an image on a transfer material (recording medium) such as a sheet, such as a copying machine, a printer or a facsimile machine. is there.

[0002]

2. Description of the Related Art (Prior Art 1) As an example of a conventional image forming apparatus of this type, FIGS. 6 and 7 show a compact digital copying machine employing an electrophotographic recording system.

In the conventional image forming apparatus, a sheet path as shown in FIG. 6 is formed, and the sheet 5 is sent out from the sheet feeding cassette 6a or the multi sheet feeding tray 14. The sheets 5 stacked in the paper feed cassette 6a are separated one by one by the separating means 6b and are conveyed downstream in the sheet path by the feeding means 6c.

The image information formed on the sheet 5 is read by the document reading device 1 of a document placed on the document table 2, and the signal is sent to the laser scanner unit 13. The laser scanner unit 13 reflects the laser light corresponding to the transmitted signal on the polygon mirror 13a,
The photosensitive drum 11a is irradiated with light through the imaging lens 13b. A latent image is formed on the photosensitive drum 11a by the emitted laser light, and the toner 10c sent by the developing sleeve 10b adheres to form a toner image on the photosensitive drum 11a.

The conveyed sheet 5 is the photosensitive drum 1
The toner image that has been sent downwardly to the transfer roller 1a
Is transferred by. The sheet 5 is sent to the fixing device 8, passes between the fixing film 8c heated by the heater 8b and the pressure roller 8a, and after the image is fixed, the sheet discharge tray 9
Is discharged to.

The toner remaining on the photosensitive drum 11a is
It is scraped off by the cleaning blade 11b and collected in the waste toner container 11c.

During the printing operation, the temperature of the fixing device 8 for fixing due to high heat, the main motor 17, the power supply board 22 and the like rises, and the heat radiation from these causes the temperature of other units such as the cleaning unit 11 and the developing unit 10 to rise. The thermal deformation of the cleaning blade 11b in the cleaning unit 11 and the fusion of the waste toner accumulated in the waste toner container 11c may occur.

Further, since the unit itself which is generating heat is adversely affected by shortening the life of the electric elements incorporated therein,
It is necessary to cool the units that generate heat and those that dislike heat.

As the cooling means, a method of discharging the air inside the machine by a fan has been adopted. In particular, the heat generated by the fixing device 8 is large, and in order to uniformly and efficiently discharge the air around the fixing device heated by the fixing device 8 to the outside of the device, a cross flow fan 20 for cooling is provided above the fixing device.

(Conventional Example 2) As another example of the conventional image forming apparatus, FIG. 8 shows a small digital copying machine which employs an electrophotographic recording system and employs a small axial fan as an exhaust means.

An axial fan has a smaller area for blowing air than a cross flow fan, and an axial fan is provided to evenly blow air in a direction (longitudinal direction) perpendicular to a conveyance path of units to be cooled, such as the fixing unit 8 and the cleaning unit 11. The flow fan 15 is arranged on the front side of the main body and has a structure for sending air into the main body.

By adopting the axial flow fan, the size of the main body was suppressed to be smaller than that of the conventional example 1 using the cross flow fan, and proper cooling was performed.

[0013]

However, in the case of the above-mentioned prior art, the following problems have occurred.

In the image forming apparatus according to Conventional Example 1,
Since there is no specific intake port for taking in the outside air to the main body of the device and air is drawn from the gap between each unit, it is not possible to discharge air efficiently only from the necessary places, and there is a margin in specifications. It was necessary to exhaust a large amount of air with a large cross flow fan.

The cross-flow fan requires a large space for arrangement, which may be a factor in deteriorating the degree of freedom of unit arrangement and increasing the size of the main body, which is one factor that hinders downsizing of the main body. Was becoming.

Further, the cost of the cross flow fan itself is high, which is also a factor to prevent cost reduction.

In the image forming apparatus according to Conventional Example 2,
The intake port is located on the front of the device body that is most visible,
The appearance was spoiled and the fan operating noise was uncomfortable for the operator.

Further, since the intake side of the fan is close to the exterior,
The fan takes in foreign matter such as dust and dust in the air,
There is a possibility that the optical components such as the polygon mirror 13a and the optical lens 13b may be soiled and the image may be affected.

Further, even in the on-demand type heat fixing device, when a large amount of documents are continuously printed, a large amount of heat is generated during the printing operation, so that the heat remaining in the heat fixing device is fixed even after the printing is completed. It is a factor that raises the temperature around the container and raises the temperature of other units.Although the fan was rotated for a certain period of time after printing was completed, the warm air around the fixing device was exhausted. Since the exhaust is also performed from a location where the temperature does not rise, there is a possibility that the cooling efficiency may be reduced in the axial fan, which has less air volume than the cross flow fan.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and its purpose is to suppress the entry of foreign matter into the main body of the apparatus without impairing the appearance of the main body of the apparatus, An object of the present invention is to provide a highly reliable image forming apparatus that effectively cools a unit to be cooled and downsizes the apparatus body.

[0021]

In order to achieve the above object, according to the present invention, there is provided an intake port provided on the front side of one side surface of the apparatus main body for taking in outside air into the apparatus main body, and the other side of the apparatus main body. Is provided on the rear side of the device and is provided on an approximately straight line connecting the intake port and the exhaust port with an exhaust port for exhausting the air inside the device main body to the outside of the device main body. An image forming apparatus for forming an image on a sheet, comprising: an exhaust unit that guides to an exhaust port and exhausts to the outside of the apparatus main body, and is cooled on a substantially straight line connecting the intake port and the exhaust port. A unit to be cooled is provided, and a wind setting unit that sets at least one of a wind direction and an air volume in the apparatus body is provided between the intake port and the unit to be cooled. Characterize.

It is also preferable that the exhaust means includes an axial fan.

It is also preferable that the wind setting means sets at least one of the wind direction and the air volume in the main body of the apparatus by means of a ventilation hole provided in the wall surface of the main body of the apparatus.

It is also preferable that the wind setting means sets the wind direction in the apparatus main body by the position of the ventilation hole provided on the wall surface in the apparatus main body.

It is also preferable that the wind setting means includes an opening changing member that changes the size of the opening of the ventilation hole.

It is also preferable that a plurality of the ventilation holes are provided and the wind setting means includes an opening / closing member for opening and closing a predetermined number of the ventilation holes of the plurality of ventilation holes.

An exposure unit that forms an electrostatic latent image on the image carrier by exposing the image carrier, and a toner image obtained by developing the electrostatic latent image formed on the image carrier. And a fixing unit for fixing the unfixed toner image transferred to the transfer material after the transfer of the toner to the transfer material, and a cleaning unit for cleaning the toner remaining on the image bearing member. It is also preferable that at least one of the exposure unit, the cleaning unit, the fixing unit, and the power supply board is included.

It is also preferable that the fixing unit is provided closer to the exhaust port than the cleaning unit.

The exhaust means includes a branch duct having an air flow path leading to each of the plurality of units to be cooled,
It is also preferable to provide a duct having a shutoff means provided in at least one of the branch ducts to open and close the air flow path.

It is also preferable that the exhaust means closes air passages other than the air passage leading to the fixing unit by the shielding means and can suck air only from the air passage leading to the fixing unit.

It is also preferable to include control means for operating the shielding means in conjunction with driving of the apparatus body.

The control means transfers the toner image obtained by developing the electrostatic latent image formed on the image carrier to a transfer material, and transfers the unfixed toner image transferred to the transfer material. During the operation of the image forming means for fixing, all the air flow paths are opened by the shielding means, and after the operation of the image forming means,
It is also preferable to close the air flow paths other than the air flow path leading to the fixing unit by the shielding means so that air is sucked only from the air flow path leading to the fixing unit.

It is also preferable that the exhaust means includes a solenoid for operating the shielding means.

It is also preferable that the intake port is provided near a corner between the one side surface and the front surface of the apparatus main body.

It is also preferable that the intake port and the exhaust port are respectively provided in the vicinity of a diagonal line of the apparatus main body.

[0036]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be illustratively described in detail below with reference to the drawings. However, the dimensions of the components described in this embodiment,
The material, the shape, and the relative arrangement of them should be appropriately changed depending on the configuration of the device to which the invention is applied and various conditions, and the scope of the invention is not limited to the following embodiments.

(Embodiment 1) An electrophotographic image forming apparatus according to Embodiment 1 of the present invention will be described with reference to FIGS. 1, 2 and 3. The same components as those described in the section of the prior art are designated by the same reference numerals.

FIG. 1 is a schematic perspective view of the image forming apparatus according to the first embodiment of the present invention, FIG. 2 is a schematic top view of the image forming apparatus according to the present embodiment, and FIG. FIG. 3 is a schematic cross-sectional view of the image forming apparatus according to this embodiment.

A sheet path as shown in FIG. 3 is formed,
The sheet 5 as the transfer material is sent out from the paper feed cassette 6a or the multi-paper feed tray 14. Paper feed cassette 6a
The sheets 5 stacked on the sheet are separated one by one by the separating claw 6b, and are conveyed downstream in the sheet path by the feeding roller 6c.

The image information formed on the sheet 5 is read from the original 3 placed on the original table 2 and pressed against the original table 2 by the pressure plate 4, the original reading device 1 including a reading sensor 1a and a sensor moving device. And the signal is sent to the laser scanner unit 13 as an exposure unit.

Explaining the image forming operation by the image forming means, the laser scanner unit 13 reflects the laser beam corresponding to the sent signal to the polygon mirror 13a and the image forming lens 13b to the reflecting mirror 13c. The photosensitive drum 11a as an image carrier is irradiated with the light.

An electrostatic latent image is formed on the photosensitive drum 11a by the radiated laser beam, and the toner 10c provided in the developing container 10a of the developing unit 10 is sent by the developing sleeve 10b and adheres to the toner 10c. A toner image is formed on the photosensitive drum 11a.

The sheet 5 conveyed by the conveying means 6 including the conveying roller pair 6d is conveyed to below the photosensitive drum 11a,
The formed toner image is transferred by the transfer roller 7. The sheet 5 is sent to a fixing device 8 as a fixing unit, passes between a fixing film 8c heated by a heater 8b and a pressure roller 8a, and after an image is fixed, a discharge roller pair 6e discharges a sheet discharge tray 9 Is discharged to.

The toner remaining on the photosensitive drum 11a is
In the cleaning unit 11, it is scraped off by the cleaning blade 11b and collected in the waste toner container 11c.

During the printing operation by the image forming means, the temperature of the fixing device 8 for fixing by high heat, the main motor 17, the power supply board 22 and the like rises, and the heat radiation from these causes the cleaning unit 11, the developing unit 10 and other units. There is a possibility that the temperature may be increased and the cleaning blade 11b in the cleaning unit 11 may be thermally deformed or the waste toner accumulated in the waste toner container 11c may be fused.

Further, since the unit itself which is generating heat is adversely affected by shortening the life of the built-in electric elements,
It is necessary to cool the units that generate heat and those that dislike heat. Here, a unit requiring cooling in this way is referred to as a cooling target unit.

Therefore, in the present embodiment, as shown in FIGS. 1 and 2, the intake port 18 is provided near the corner of the front surface of one side surface of the apparatus (image forming apparatus) main body 23 (the front side of the one side surface). And the exhaust port 19 is disposed on the other side surface (rear side) which is the opposite side of the intake port 18 in the diagonal direction of the apparatus body,
By disposing one axial flow fan 15 as an exhaust means on a substantially straight line connecting the intake port 18 and the exhaust port 19, the basic air flow (air flow) can be obtained substantially on the diagonal line of the main body of the device (line X shown in FIG. 2). A road).

Here, the front surface of the apparatus main body 23 is a surface that faces forward when the image forming apparatus is installed, and a user (operator) who operates on the side where the operation panel is provided as shown in FIG. Is a surface facing. Further, in the present embodiment, the intake port 18 is provided on the side surface of the front cover 24 of the apparatus body 23. Further, the fixing device 8 is provided on the side of the exhaust port 19 which is the other side surface with respect to the photosensitive drum 11a and the cleaning unit 11.

When the axial fan 15 operates, the intake port 18
From the outside, the air (outside air) outside the machine is taken into the inside of the machine (inside the apparatus main body 23) and flows over the scanner support plate 12 where the laser scanner unit 13 is arranged as shown in FIG.
w A, fl that flows between the carriage support 32 on which the cleaning unit 11 and the fixing unit 8 are arranged and the scanner support plate 12
ow B, a power board 32 on which the power board 22 is arranged, and a flow C flowing between the carrier 32,
The cleaning unit 11, the fixing device 8, the laser scanner unit 13, and the power supply board 22, which are cooling target units, are cooled.

The air that has passed through each unit to be cooled passes through the axial fan 15 and is discharged from the exhaust port 19 provided in the left cover 28 which is the other side surface of the apparatus main body 23.

The units to be cooled are respectively arranged in the vicinity of the diagonal line of the main body of the apparatus, and are arranged so that the wind is evenly applied to the entire unit. Further, as a wind setting means, the front side plate 25 as a wall surface in the main body 23 of the apparatus is further provided. By changing the positions of the plurality of ventilation holes 27 provided in each flow, inside the front plate 25, flow A, flow B, flow can be changed.
Each direction of C can be adjusted.

Therefore, the wind can be sent to a position slightly away from the diagonal line of the main body of the apparatus, and the wind can be appropriately sent according to the arrangement of each unit.

Further, by increasing or decreasing the number of holes in each flow, it is possible to adjust the air flow distribution and the air flow direction of the flow A, flow B, flow C, etc., and a more efficient air flow is formed with a simple structure. it can. The number of ventilation holes may be set based on the specifications of the device, or an opening / closing member for opening and closing a predetermined number of ventilation holes may be provided among the plurality of ventilation holes. Further, an opening changing member capable of changing the size of the opening of the ventilation hole may be provided, and the amount of airflow or the direction of airflow may be adjusted by changing the size of the opening of the ventilation hole.

In this embodiment, the intake port 1
8 and the exhaust port 19 are diagonally arranged in the device main body 23, the intake port 18 may be disposed on the front side of the device main body 23 and the exhaust port 19 may be disposed on the rear side of the device main body 23. Good.

As described above, according to this embodiment,
The intake port 18 is disposed near a corner of the front surface of the device body 23, and the exhaust port 19 is disposed on a side face of the intake port 18 opposite to the device body diagonal direction, and one axial fan 15 is connected to the intake port 18. By arranging on the substantially straight line connecting the exhaust port 19, the airflow can be generated on the substantially diagonal line of the apparatus main body 23.

Further, the unit to be cooled is arranged near the diagonal line of the main body of the apparatus, and means for setting the wind direction and air volume in the main body 23 of the apparatus is provided between the intake port 18 and the unit to be cooled, whereby a small exhaust means is provided. Even in this case, the air volume can be appropriately distributed and the air can be evenly sent to the units to be cooled for cooling.

In addition, since the intake port 18 and the exhaust port 19 are respectively arranged on the side surfaces of the apparatus main body 23, the appearance of the front of the apparatus main body 23, which is most noticeable, is not spoiled, and the exhaust air is directed toward the operator. Never send.

Further, since the axial fan 15 is arranged away from the intake port 18 and is far from the position where the outside air is taken in, foreign matter such as dust and dust can be suppressed from entering.

Further, by using the airflow as described above, the exhaust means can be one small axial fan, so that the installation space required in the apparatus main body 23 can be made small, that is, the apparatus. It is possible to reduce the size of the main body 23 and reduce the cost.

(Second Embodiment) An image forming apparatus according to a second embodiment of the present invention will be described with reference to FIGS.
The same components as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

FIG. 4 is a schematic sectional view of an electrophotographic image forming apparatus according to the second embodiment of the present invention. FIG. 5 is a schematic sectional view of the fan holder according to the present embodiment,
(A) shows when the shielding plate is opened, and (b) shows when the shielding plate is closed.

As shown in FIGS. 5 (a) and 5 (b), the duct 16 which also serves as a fan holder and is attached to the axial fan 15 as exhaust means is provided for the axial fan 15 and each unit to be cooled. A branch duct having an air flow (air flow path) communicating with each other is provided, and the branch duct is a flow A from the laser scanner unit 13.
To the first duct 16a for taking in the air, the second duct 16b for taking in the flow B from the cleaning unit 11 and the fixing device 8, and the third duct 16c for taking in the flow C from the power supply board 22.

As shown in FIG. 5A, the first duct 16a and the third duct 16c in the duct 16 are provided with shield plates 35 and 36 rotatable by an arm 37.
The air flow is opened at the positions of 5a and 36a. The arm 37 and the shield plates 35 and 36 form a shield means.

Then, as shown in FIG. 5B, the arm 3
7 is slid in the direction of arrow D, and the shielding plates 35 and 36 are rotated in the directions of arrows E and F to turn 35b and 36b, respectively.
By setting the position to, the flow A passing through the laser scanner unit 13 and the flow C passing through the power supply board 22 are blocked, and the air can be concentratedly drawn to the air flow flow B passing through the fixing device 8 and the cleaning unit 11. Become.

Since the suction force of the axial fan 15 has a margin and the suction (intake) efficiency is improved, more wind can be sucked from the fixing device 8 and the cleaning unit 11. is there.

Further, there is provided a control means for operating the shielding means in conjunction with the driving of the apparatus main body 23, and when the printing by the image forming means is completed by the control means, the shielding plates 35, 36 are moved to the apparatus main body 23. The air flow is closed by being driven by the arm 37 which is interlocked with the driving of the.

Therefore, by exhausting all the airflow during printing and exhausting the hot air around the fixing device 8 after the printing is completed, it is possible to effectively exhaust the inside of the apparatus main body 23.

In the present embodiment, the air flow flow passing through the fixing device 8 and the cleaning unit 11 is made.
Although the amount of airflow is concentrated on B to increase the cooling effect, the airflow can be controlled by controlling the shielding means according to the operating status of the apparatus main body 23. It is possible to increase the air volume and enhance the cooling effect.

The control means for interlocking the shield plates 35 and 36 with the image forming means may be provided in the exhaust means or in the control section of the apparatus main body 23.

The arm 37 may be driven by a solenoid (not shown).

[0071]

As described above, according to the present invention,
Since it is possible to generate an air flow path on a substantially diagonal line of the apparatus main body and blow the air evenly over the entire unit to be cooled, it is possible to enhance the cooling effect.

Furthermore, a more efficient air flow path can be formed by adjusting the ventilation holes on the wall surface provided in the main body of the apparatus.

The intake port and the exhaust port are provided on the side surface of the main body of the apparatus and do not spoil the appearance of the front surface of the main body of the apparatus. Further, since the exhaust means and the intake port are separated from each other, dust and dust inside the main body of the apparatus It is possible to suppress the entry of foreign matter.

Further, since a small axial fan can be used, the main body of the apparatus can be downsized and the cost can be reduced.

Further, since the air flow passage can be controlled according to the operating condition of the main body of the apparatus, the cooling effect can be improved by increasing the air volume of the specific air flow passage.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic top view of the image forming apparatus according to the first embodiment of the present invention.

FIG. 3 is a schematic cross-sectional view of the image forming apparatus according to the first embodiment of the present invention.

FIG. 4 is a schematic sectional view of an image forming apparatus according to a second embodiment of the present invention.

FIG. 5 is a schematic cross-sectional view of a fan holder according to a second embodiment of the present invention, (a) shows a state where a shield plate is opened, and (b).
Indicates the time when the shield plate is closed.

FIG. 6 is a schematic cross-sectional view of an image forming apparatus according to Conventional Example 1.

FIG. 7 is a schematic top view of an image forming apparatus according to Conventional Example 1.

FIG. 8 is a schematic top view of an image forming apparatus according to Conventional Example 2.

[Explanation of symbols]

1 Document reader 1a Read sensor 1b Sensor moving device 2 Platen 3 manuscripts 4 Pressure plate 5 sheets 6 Transport means 6a paper feed cassette 6b Separation claw 6c Paper feed roller 6d Conveyor roller pair 6e Ejection roller pair 7 Transfer roller 8 fixing device 8a pressure roller 8b heater 8c fixing film 9 Output tray 10 Development unit 10a developing container 10b Development sleeve 10c toner 11 Cleaning unit 11a Photosensitive drum 11b cleaning blade 11c Waste toner container 12 Scanner support plate 13 Laser scanner unit 13a polygon mirror 13b Imaging lens 13c reflective mirror 14 Multi paper tray 15 Axial fan 16 ducts 16a First duct 16b Second duct 16c Third duct 17 Main motor 18 air intake 19 exhaust port 20 cross flow fan 21 Conveyor belt 22 Power board 23 Device body 24 Front cover 25 front plate 26 Rear plate 27 Vents 28 Left cover 29 drive gear 30 electric circuit board 31 Rear plate 32 carrier 33 power supply board stand 34 Operation panel 35 Shield 36 Shield 35a Shield plate (when opened) 35b Shield plate (when shielded) 36a Shield plate (when opened) 36b Shield plate (when shielded) 37 arms

Front page continued (51) Int.Cl. ⁷ Identification code FI theme code (reference) F04D 29/54 F04D 29/54 F 3H034 29/56 B 5C062 E 29/56 29/58 M G03G 15/00 550 29 / 58 15/20 102 G03G 15/00 550 H04N 1/00 D 15/20 102 G03G 21/00 534 H04N 1/00 B41J 29/00 P F Term (reference) 2C061 AP03 AP04 BB02 BB27 BB28 CN01 CN02 CN04 CN05 CN08 CN13 2H027 DA32 JA11 JB13 JB15 JB17 JB26 JB27 JC04 JC07 JC08 JC16 2H033 AA41 BA02 BA05 BA29 2H071 BA35 DA02 DA12 DA13 DA34 EA04 EA10 3H021 AA01 AA08 BA01 BA02 BA02 BA01 BA26 BA11 CA09 CA10 DA01 DA03 DA10 DA02 DA20 DA10 DA02 DA02 DA10 DA02 DA02 EE18 5C062 AA05 AB00 AD06 BA07

Claims (15)

[Claims] 1. A front side of one side surface of an apparatus main body,
An intake port that takes in outside air into the device body, an exhaust port that is provided on the rear side of the other side surface of the device body and that exhausts the air inside the device body to the outside of the device body, and connects the intake port and the exhaust port. An image forming apparatus for forming an image on a sheet, which is provided on a substantially straight line and includes an exhaust unit that guides air inside the apparatus main body to the exhaust port and exhausts the air to the outside of the apparatus main body. And a cooling target unit to be cooled is arranged on a substantially straight line connecting the exhaust port and the exhaust port, and between the intake port and the cooling target unit, the direction and volume of wind in the apparatus main body. An image forming apparatus comprising: a wind setting unit that sets at least one of the two. 2. The image forming apparatus according to claim 1, wherein the exhaust unit includes an axial fan. 3. The wind setting means sets at least one of a wind direction and an air volume in the apparatus body by means of a ventilation hole provided in a wall surface in the apparatus body. 2. The image forming apparatus according to item 2. 4. The wind setting means sets the wind direction in the main body of the apparatus according to the position of a ventilation hole provided on a wall surface of the main body of the apparatus. Image forming apparatus. 5. The image forming apparatus according to claim 3, wherein the wind setting unit includes an opening changing member that changes the size of the opening of the ventilation hole. 6. A plurality of the vent holes are provided, and the wind setting means includes an opening / closing member for opening and closing a predetermined number of the vent holes of the plurality of vent holes. Alternatively, the image forming apparatus according to item 5. 7. An exposure unit for exposing an image bearing member to form an electrostatic latent image on the image bearing member, and an electrostatic latent image formed on the image bearing member. A cooling unit for cleaning the toner remaining on the image carrier after the toner image is transferred onto the transfer material; and a fixing unit for fixing the unfixed toner image transferred on the transfer material. The image forming apparatus according to claim 1, wherein the unit includes at least one of the exposure unit, the cleaning unit, the fixing unit, and a power supply board. 8. The image forming apparatus according to claim 7, wherein the fixing unit is provided closer to the exhaust port than the cleaning unit. 9. The exhaust means includes a branch duct having an air flow path that communicates with each of the plurality of units to be cooled, and a blocking means that is provided in at least one of the branch ducts to open and close the air flow path. 9. The image forming apparatus according to claim 1, further comprising a duct having a. 10. The exhaust means closes air passages other than the air passage leading to the fixing unit by the shielding means, and can suck air only from the air passage leading to the fixing unit. The image forming apparatus according to claim 9. 11. The image forming apparatus according to claim 9, further comprising control means for operating the shielding means in conjunction with driving of the apparatus body. 12. The control means transfers a toner image obtained by developing an electrostatic latent image formed on the image carrier to a transfer material, and the unfixed toner transferred to the transfer material. During the operation of the image forming means for fixing the image, all the air passages are opened by the shielding means, and after the operation of the image forming means, the air passages other than the air passages communicating with the fixing unit by the shielding means. The image forming apparatus according to claim 11, wherein the image forming apparatus is closed, and the air is sucked only from an air flow path communicating with the fixing unit. 13. The image forming apparatus according to claim 9, wherein the exhaust means includes a solenoid that operates the shielding means. 14. The image forming apparatus according to claim 1, wherein the air inlet is provided near a corner between the one side surface and the front surface of the apparatus main body. 15. The image forming apparatus according to claim 1, wherein the intake port and the exhaust port are provided near a diagonal line of the apparatus main body.