JP4904897B2 - Image forming apparatus - Google Patents

Description

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

In an image forming apparatus such as a copying machine or a printer to which an electrophotographic system is applied, for example, an electrostatic latent image formed on a photosensitive drum is developed by a developing device (developing device) using a developer, and a photosensitive member is developed. A toner image is formed on the drum, and the toner image formed on the photosensitive drum is transferred and fixed onto a recording medium conveyed from the paper feeding unit to form an image. .
In such an image forming apparatus, air is caused to flow through the hollow portion of the hollow cylindrical guide that guides the recording paper, and the recording paper is adsorbed on the guide surface by sucking air from the slit formed on the guide surface, A configuration for stably transporting recording paper has been proposed (see, for example, Patent Document 1).
In order to prevent dew condensation on the guide plate that guides the recording paper, a configuration in which a through hole is formed in the movable branch member that branches the conveyance path in the double-sided printing mechanism and the air is ventilated has been proposed (for example, see Patent Document 2). ).

Japanese Patent Laid-Open No. 06-24071 Japanese Patent Laid-Open No. 2001-316018

  The image forming apparatus includes a member (for example, a fixing device) that generates various kinds of heat. In some cases, an electronic component (for example, a sensor) that requires countermeasures against heat must be disposed in the vicinity of such a heat generating member. In such a case, in order to suppress an increase in the size of the device, It is necessary to efficiently cool electronic components with the simplest possible configuration. Such cooling is preferably performed with air. However, effective solutions in such a case are not disclosed in Patent Documents 1 and 2 described above. More specifically, Patent Document 2 discloses a configuration for cooling the entire conveyance path of the recording paper, and it cannot cool by blowing air only on an arbitrary member to be cooled.

  The present invention has been made in order to solve the technical problems as described above, and an object of the present invention is to regulate the flow of air inside the apparatus and supply the air to a place that needs to be cooled. It is an object of the present invention to provide an image forming apparatus capable of performing the above.

The above object, an image forming apparatus to which the present invention is applied, is arranged close to the fixing device, and an electronic component cooling required in order to reduce the effect of heat received from the fixing device, a fixing device, and an electronic Air flow that increases the flow velocity of the air flow by increasing the flow velocity of the air flow by the air guiding means that guides the air flow toward the parts and the rib structure arranged so that a part of the air flow guided by the air guiding means is restricted divided by the flow rate change means you cool the electronic components, with direct a portion of the air flow velocity is increased to the fixing device by the flow rate changing means, an air flow toward the fixing device, in the course guided by the air guide means a flow rate equalizing means is combined with the air flow without flow rate is increased by the flow rate changing means to substantially equalize the flow rate Te, a is including ones.

The air guide means guides a part of the air flow to the fixing device without passing through the flow speed changing means, and thereby, a part of the flow speed equalizing means is configured. .

When regarded from another point of view, the image forming apparatus to which the present invention is applied includes a forming portion for forming an air flow in the apparatus incorporating the apparatus external air, in order to reduce the effect of heat received from the fixing unit cooling and necessary parts, components and positioned between the forming section, forming predetermined in the overall air formed by the forming unit together with the direct flow of air is formed in the component and the fixing device by the unit one It includes a guide portion for directing the increase the flow rate of the air part article by disposed ribs structure as part is squeezed, the formation unit is disposed upstream of the guide portion, taken into the apparatus air a wall that prevents the flow, disposed adjacent to the forming or wall portion to wall portion, and a ventilation part for guiding the air to the guide portion, the wall portion of the forming section, the air taken into the apparatus The air is guided to the ventilation section and the air is not guided to the ventilation section. The are those classified into the air toward the fixing device without flow rate is increased, the turn to the fixing device part of the air flow rate is increased by the guide portion, the air towards the fixing device, the wall portion of the forming section The flow rate is made substantially uniform by merging with the air whose flow rate cannot be increased by the guide portions divided by .

Here, the ventilation part is located in a direction deviating from the direction in which air flows by the forming part, and the guide part seems to circulate a part of the air guided to the guide part by the ventilation part in a direction opposite to the deviating direction. It is possible to provide a partition rib formed so as to be guided. In addition, the partition rib is composed of a pair separated from each other, and the guide portion further includes a destination rib arranged so that a flow path area is narrowed between the pair of partition ribs, and the destination rib is downstream in the air flow direction. It can be characterized by being located closer.

  Further, the pair of partition ribs can be characterized in that they are arranged in a direction opposite to the forming portion with respect to the ventilation portion. The guide portion further includes a notch formed in the partition rib located on the side farther from the forming portion of the pair of partition ribs, and the notch is positioned upstream of the air flow direction. Can be a feature. In addition, a recording material conveyance path is located between the component and the guide portion.

  According to the present invention, it is possible to supply air to a place where cooling is necessary.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a schematic configuration diagram showing an image forming apparatus according to the present embodiment.
The image forming apparatus 10 shown in FIG. 1 is a so-called tandem type in which four color process cartridges (image forming units, drum cartridges) 11a, 11b, 11c, and 11d are sequentially arranged in a vertical direction in a main body 10a. In addition, a conveyance path 12 through which a sheet (recording material) P is conveyed from a substantially vertical lower side to an upper side is disposed at a corresponding position in each of the process cartridges 11a to 11d. Further, a paper feed cassette 13 for storing the paper P that is transported through the transport path 12 and to which the toner images are sequentially transferred is disposed further below (upstream) of the lowermost (uppermost) process cartridge 11a. Has been. In addition, due to the size of the paper P stored in the paper feed cassette 13, a part of the paper feed cassette 13 protrudes to the back side (rear side, in side) of the main body 10a. If it is a small size, it does not protrude from the main body 10a. The main body 10a includes a housing frame 41 (see FIG. 5) and a cover 42 (see FIG. 5) as an exterior body of the housing frame 41.

  The process cartridges 11 a to 11 d form toner images for yellow (Y), magenta (M), cyan (C), and black (K) in order from the upstream side of the conveyance path 12. Each of the process cartridges 11a to 11d is a cartridge in which a photosensitive drum (image carrier) 14 and various electrophotographic devices sequentially arranged around the photosensitive drum 14 are integrally formed into a cartridge. It is. The device includes a charging roller that precharges the photosensitive drum 14 and a developing device 27 that develops the electrostatic latent image formed on the photosensitive drum 14 charged by the charging roller with each corresponding toner. And a cleaning device that removes waste toner on the photosensitive drum 14.

  An exposure device (ROS) 15 common to the process cartridges 11a to 11d is disposed on the opposite side of the transport path 12 of the process cartridges 11a to 11d. The exposure device 15 drives and drives four semiconductor lasers (not shown) based on image data corresponding to each color. The light from the four semiconductor lasers is deflected and scanned by a polygon mirror (not shown) and guided to an exposure point on the photosensitive drum 14 through an fθ lens (not shown) and a plurality of reflection mirrors, thereby the photosensitive drum 14. It is configured to draw a light image on top.

  A conveyance belt 16 that circulates along the conveyance path 12 is disposed at a location corresponding to each photosensitive drum 14 of the process cartridges 11a to 11d. The transport belt 16 is made of a belt material that can electrostatically attract the paper P, and is stretched around a pair of driving roller 17A and driven roller 17B. Further, an adsorption roller 18 for electrostatically adsorbing the paper P to the conveyance belt 16 is disposed in the conveyance path 12.

  A transfer roller 19 is disposed on the back side of the conveyance belt 16 corresponding to each photosensitive drum 14 of the process cartridges 11a to 11d. The transfer roller 19 is for transferring the toner image formed on the photosensitive drum 14 onto the paper P by bringing the photosensitive drum 14 and the paper P on the transport belt 16 into close contact with each other.

  A fixing device (heating element) 20 is provided in the conveyance path 12 further above (downstream side) of the uppermost (most downstream) process cartridge 11d. On the upper part of the main body 10a, a conveyance guide 28 (see FIG. 5) for guiding the sheet on which the toner image has been fixed by the fixing device 20, and a sheet discharge roll 29A for discharging the sheet guided by the conveyance guide 28. , 29B and a paper discharge unit 21 that is formed integrally with the main body 10a and accommodates paper discharged by the paper discharge rolls 29A, 29B. The main body 10 a is provided with a reversing conveyance path 22 for reversing the paper P, one side of which has been fixed by the fixing device 20, and sending it again to the conveyance path 12.

  Here, an ADC sensor (electronic component, component) 31 for adjusting toner density, which includes a reflection type photosensor for detecting the patch mark density of toner formed on the conveyor belt 16, and an ADC are provided above the conveyor belt 16. A cleaner 32 that contacts the surface of the conveyor belt 16 on the downstream side of the conveyor belt 16 of the sensor 31 to clean the surface of the conveyor belt 16, and a toner that is removed from the surface of the conveyor belt 16 by the cleaner 32 is collected. A collection unit (not shown) is provided.

  The ADC sensor 31 is used for a process control operation for controlling the density of each color toner image to be equal to a predetermined density. This process control operation is performed, for example, when the image forming apparatus 10 is turned on, when a predetermined number of prints are performed, when the rotational speed of the photosensitive drum 14 reaches a predetermined value, or when the main body 10a is operated. It is executed at a predetermined timing such as when the internal temperature or humidity changes by a predetermined value or more.

  Briefly explaining the process control operation, patch marks made of toner images of yellow (Y), magenta (M), cyan (C), and black (K) are formed on the photosensitive drum 14 by 100%, 50%, or the like. And is transferred to the conveyor belt 16. The toner patch marks of each color on the transport belt 16 are read by the ADC sensor 31 and the toner density in the developing device 27 of each color is adjusted, so that a predetermined image density is obtained.

  The ADC sensor 31 is disposed close to the driven roller 17B disposed on the upper side of the transport belt 16. The reason for this arrangement is as follows. Since the toner patch mark is placed on the conveyance belt 16, the separation distance between the conveyance belt and the ADC sensor 31 is required to be constant. For this reason, it is preferable to make it adjoin to a pair of roller 17A, 17B. The toner patch marks on the conveyor belt 16 are removed by the cleaner 32 and collected by a collecting unit (not shown). In order to secure the capacity of the collection unit, it is more preferable that the collection unit be close to the driven roller 17B located on the upper side of the pair of rollers 17A and 17B. Therefore, as in the present embodiment, the ADC sensor 31 is disposed close to the upper driven roller 17B.

  An intake fan (air guiding means, forming unit) 43 is disposed on the back side of the image forming apparatus 10. The intake fan 43 is not located at the center of the main body 10a when viewed from above (see FIG. 5). That is, the intake fan 43 is located at the upper left portion of the main body 10a when viewed from the front. The intake fan 43 is for taking in air from outside the apparatus and supplying air into the apparatus. The air (air flow) by the intake fan 43 is used to cool each part inside the apparatus.

FIG. 2 is a diagram for explaining the manual feed tray 23.
As shown in FIG. 2, the main body 10a of the image forming apparatus 10 is provided with a manual feed tray 23 that is rotatable about a rotation fulcrum J provided at the lower end. That is, the manual feed tray 23 is configured to be openable and closable on the front side (front side and out side). When the manual feed tray 23 is rotated in the opening direction, a desired paper P can be set in a not-shown insertion window (paper feed port). As described above, the image forming apparatus 10 is configured to feed paper P other than the paper P stored in the paper feed cassette 13 from the manual feed tray 23.

  Here, in a state where the paper P on which the toner image is to be transferred is set, either one of the paper P in the paper feed cassette 13 and the paper P in the manual feed tray 23 is instructed by a user to a control device (not shown). Are sent at a predetermined timing. The sent paper P is transported to the transport path 12 via a plurality of transport rollers 24 and sent to the transfer positions of the process cartridges 11 a to 11 d via the transport belt 16.

FIG. 3 is a view for explaining the front cover 25.
As shown in FIG. 3, the main body 10a of the image forming apparatus 10 is provided with a front cover 25 that is rotatable about a rotation fulcrum J provided at the lower end. The front cover 25 functions as an external cover together with the main body 10a in the closed state. That is, the front cover 25 constitutes a side wall portion on the upper side of the paper feed cassette 13 and on the front side of the image forming apparatus 10.

  The front cover 25 is provided with a conveyance belt 16, a driving roller 17A, a driven roller 17B, an adsorption roller 18, a transfer roller 19, and a reverse conveyance path 22. Therefore, when the front cover 25 is opened, these components are accompanied and separated from the main body 10a side. Therefore, the process cartridges 11a to 11d are exposed by opening the front cover 25, and the user can easily access the transport path 12.

  Here, each of the process cartridges 11a to 11d is detachably attached to the main body 10a in a substantially horizontal direction. Therefore, the process cartridges 11a to 11d can be attached and detached by opening the front cover 25 of the main body 10a. A set detection sensor (not shown) detects the set state of each of the process cartridges 11a to 11d and outputs the detection result to a control device (not shown).

  Thus, by opening the front cover 25, the process cartridges 11a to 11d can be exposed and replaced. Further, it is possible to deal with a paper jam (jam clear) with the photosensitive drum 14 exposed. Thus, the maintainability of the image forming apparatus 10 is improved.

FIG. 4 is a view for explaining a pulled-out state of the paper feed cassette 13.
The paper feed cassette 13 is accommodated in a cassette accommodating portion 26 provided in the main body 10a, and is configured to be drawable from the front side of the main body 10a. More specifically, the paper feed cassette 13 can be pulled out and inserted into the cassette housing portion 26 with the manual feed tray 23 and the front cover 25 closed.
The paper feed cassette 13 is provided with an insertion window (not shown) on which the paper P for the manual feed tray 23 is set. Further, the paper feed cassette 13 is provided with a part of a plurality of transport rollers 24 for transporting the paper P on the manual feed tray 23. In this way, the paper feed cassette 13 is formed with a delivery path through which the paper P set in the insertion window (not shown) is delivered to the transport path 12.

FIG. 5 is a perspective view showing the inside of the image forming apparatus 10 as viewed from the back side.
As shown in FIG. 5, the air k sucked by the intake fan 43 is guided to a ventilation path 44 formed in the housing frame 41 or the like. The air k1 guided to the ventilation path 44 passes through a gap (first air path) between a left side cover (not shown) and the housing frame 41 and is sent to the front side of the apparatus.

  Here, the air k1 guided to the air passage 44 is also sent to the developing devices 27 of the process cartridges 11a to 11d. The necessity of cooling the developing device 27 will be described. The developing device 27 (see FIG. 1) is affected by heat from, for example, an exposure lamp or a charging lamp disposed in the vicinity thereof. Furthermore, the developing device 27 stirs the developer inside the developing device 27, and the housing of the developing device 27 and the internal developer are heated by heat generated by the friction of the carrier. When the developing device 27 is heated more than necessary, there is a problem that a charging failure of the developer occurs or the toner is solidified under the influence of heat. There is also a problem that the toner image forming action is hindered due to a decrease in fluidity of the toner. For this reason, in this embodiment, the air k1 is also sent to the developing device 27 for cooling.

  The flow of the air k sucked by the intake fan 43 will be further described. A shielding plate (wall portion) 47 is arranged in front of the air k in the traveling direction formed by the intake fan 43. The shielding plate 47 is disposed so as to block the flow path of the air k. It can also be said that such a shielding plate 47 assists the formation of the flow of the air k1 to the air passage 44.

  In such a shielding plate 47, an opening (ventilation portion) 46 is formed. Part of the air k from the intake fan 43 passes through the opening 46. The air k2 (see FIG. 6) that has passed through the opening 46 flows to the front side of the apparatus, that is, to the fixing device 20 (second air path). The opening 46 is located at the center of the main body 10a. In other words, the opening 46 is located in a direction deviating from the air k flow path by the intake fan 43. In the present embodiment, the opening 46 is formed in the shielding plate 47, but it is also conceivable that the gap between the components functions as the opening.

FIG. 6 is a schematic plan view for explaining the flow of air k2 passing through the opening 46 of the shielding plate 47. FIG.
As shown in FIG. 6, the intake fan 43 is disposed closer to the left side of the main body 10a, and the ADC sensor 31 is disposed at the center of the main body 10a. In other words, the ADC sensor 31 is disposed at the center in the width direction of the paper P being conveyed. More specifically, the ADC sensor 31 is disposed close to the high-temperature fixing device 20 (see FIG. 1). The fixing device 20 in an operating state is, for example, about 200 degrees, and the ADC sensor 31 is arranged with respect to such a fixing device 20 so as to be separated by, for example, about 3 cm. As described above, since the ADC sensor 31 is always exposed to the heat from the fixing device 20, the ADC sensor 31 is provided with a countermeasure against heat as described later.

  The shielding plate 47 is erected on the plate-like frame 45. The frame 45 is to which the fixing device 20 is attached and for positioning the fixing device 20. Since the frame 45 is a member that requires strength for mounting the fixing device 20, a shielding plate 47 is erected on the frame 45.

  The frame 45 is formed with a rib structure (flow velocity changing means, flow velocity equalizing means, guide portion) 50 for supplying the air k2 that has passed through the opening 46 to a place that needs to be cooled. The rib structure 50 forms an air flow for cooling the ADC sensor 31. The rib structure 50 will be described in detail.

  The rib structure 50 includes two partition ribs (a pair of partition ribs) 51 and 52 and a destination rib 53. The partition ribs 51 and 52 are arranged such that the distance between them is substantially the same in the flow direction of the air k2.

  Each of the partition ribs 51 and 52 is formed in a curved shape when viewed from a plane. More specifically, each of the partition ribs 51 and 52 extends linearly in the front-rear direction of the main body 10a on the upstream side in the air k2 flow direction (the left side in the figure). On the other hand, the downstream side of the air k2 flow direction (the right side in the figure) has a shape that curves to the right when viewed from the flow direction of the air k2. In other words, each of the partition ribs 51 and 52 is formed to guide the air k2 to the left side of the apparatus as viewed from the front. Thus, each of the partition ribs 51 and 52 has a straight part and a curved part continuous to the straight part.

  The destination rib 53 is disposed between the partition rib 51 and the partition rib 52. The destination rib 53 is formed so that the length of the air k2 in the flow direction is shorter than that of the partition ribs 51 and 52. The destination rib 53 is located downstream of the partition ribs 51 and 52 in the air k2 flow direction.

  A notch 54 is formed on the upstream side of the partition rib 51. This notch 54 is located on the upstream side in the flow direction of the air k2. The notch 54 is formed so that a part of the air k 2 that has passed through the opening 46 proceeds without being guided by the partition rib 51.

  Since the rib structure 50 is formed in this way, it has the following action. First, a part k 2 of the air k advances in a direction deviating from the direction in which the air k flows by the intake fan 43 and passes through the opening 46. Then, k2 that has passed through the opening 46 is guided by the partition ribs 51 and 52 so as to wrap around in a direction opposite to the direction of deviation.

  Then, most of the air k 2 guided by the partition ribs 51 and 52 travels in one of the two flow paths divided by the destination rib 53. Although the separation distance between the partition ribs 51 and 52 does not change, the flow path area is narrowed by the destination rib 53. In other words, the flow path on the downstream side of the partition ribs 51 and 52 is narrower than the flow path on the upstream side of the partition ribs 51 and 52 by the destination rib 53. For this reason, the air k2 guided by the partition ribs 51 and 52 is throttled. The air k2 passing through the restricted flow path has a higher flow rate. In this way, the rib structure 50 is configured so that the air flow can be greatly received, bent and throttled to increase the flow velocity. As an example of the flow velocity value, when the flow velocity before being throttled is 0.5 m / sec, the flow velocity after being throttled is 0.8 m / sec.

  The air k2 whose flow velocity has been increased in this way is blown to the ADC sensor 31, and the effect of cooling the ADC sensor 31 can be enhanced. In the case where the conveyance path 12 is positioned between the frame 45 and the ADC sensor 31 as in the present embodiment, the frame 45 and the ADC sensor 31 are intermittently blocked by the paper P. The Therefore, the ADC sensor 31 can be cooled by the air k2 only when the paper P is not being conveyed on the conveyance path 12. That is, the air k2 cannot always be blown to the ADC sensor 31. For this reason, it can be said that it is desirable to spray the ADC sensor 31 with as high a speed as possible.

  More specifically, when viewed from above, the opening 46 and the rib structure are disposed away from each other. In other words, the air k 2 that has passed through the opening 46 is received by the partition rib 51 and is also received by the partition rib 52. In other words, not only the partition rib 51 but also the partition rib 52 receives the air k2 that has passed through the opening 46 and guides it downstream.

  The air k2 received by the partition rib 52 is guided and travels in a direction different from the direction of the ADC sensor 31. Further, the air k <b> 2 exceeding the partition rib 51 due to the notch 54 of the partition rib 51 also advances in a direction different from the direction of the ADC sensor 31. A part of the air k1 that has passed through the ventilation path 44 (see FIG. 5) merges with the air k2 that has passed through the opening 46. Due to the flow of the air k1, k2, the flow velocity of the air not directed to the ADC sensor 31 becomes uniform.

FIG. 7 is a plan view showing the inside of the image forming apparatus 10. In addition, the arrow which shows the flow of air is shown by the length relevant to the speed of the flow velocity. Therefore, the longer the arrow, the faster the flow rate.
As shown in FIG. 7, the air between the partition rib 51 and the destination rib 53 is blown against the ADC sensor 31 with the flow velocity increased. For this reason, as described above, it is possible to minimize the influence of the heat received by the ADC sensor 31 from the fixing device 20.

  Further, the other air is blown to the fixing device 20 with a uniform flow velocity. As described above, in the present embodiment, by making the flow velocity uniform, it is possible to cool the fixing device 20 as a whole, and it is possible to prevent the air flow from being unevenly stagnated. The air blown to the ADC sensor 31 and the fixing device 20 goes out of the apparatus via the conveyance path 12.

  As described above, in the present embodiment, as shown in FIGS. 1 to 4, the air from the intake fan 43 provided immediately below the paper discharge unit 21 flows along the inside of the paper discharge unit 21 and is fixed. It is configured so as to reach the ADC sensor 31 disposed to face the conveyor belt 16 via the lower side of the apparatus 20. A frame 45 shown in FIGS. 5 and 6 is provided below the fixing device 20. On the frame 45, a rib structure 50 for distributing air is formed. Heat generation of the ADC sensor 31 is prevented by locally increasing the air flow rate.

  The air k blown from the intake fan 43 flows from the opening 46 of the shielding plate 47 erected on the frame 45, flows through the upper surface of the frame 45, and is sent to the conveying belt 16 side. The frame 45 is provided with curved partition ribs 51 and 52 to send air as a whole, and a notch 54 of an appropriate size is provided in the partition rib 51 to secure the air beyond the partition rib 51. By doing so, air can be sent almost evenly. If the notch 54 is opened too much, the air from the intake fan 43 flows upward, and the upper flow rate increases too much. Therefore, an optimum size is obtained through experiments and the like.

  In addition, a short destination rib 53 is provided between the partition ribs 51 and 52 to direct air toward the ADC sensor 31. If this destination rib 53 is provided with the same length as that of the partition ribs 51 and 52, air is divided at the inlet, so that sufficient air cannot be blown to the sensor. It is preferable to do this.

  In addition, this invention is not limited to said embodiment. For example, in the above-described embodiment, the present invention is applied to the image forming apparatus 10 using a known electrophotographic method, but the present invention is not limited to this. For example, the present invention can be applied to various image forming apparatuses using an inkjet method, a thermal transfer method, or the like. Further, the conveyed sheet is not limited to the paper P. For example, the present invention can be applied to all recording sheets such as an OHP sheet.

1 is a schematic configuration diagram illustrating an image forming apparatus according to an exemplary embodiment. It is a figure for demonstrating a manual feed tray. It is a figure for demonstrating a front cover. FIG. 6 is a diagram for explaining a drawer state of a paper feed cassette. FIG. 2 is a perspective view showing the inside of the image forming apparatus viewed from the back side. It is a schematic plan view for demonstrating the flow of the air which passes along the opening part of a shielding board. 2 is a plan view showing the inside of the image forming apparatus. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Image forming apparatus, 10a ... Main body, 12 ... Conveyance path, 16 ... Conveyance belt, 20 ... Fixing device, 27 ... Developing device, 31 ... ADC sensor, 43 ... Intake fan, 44 ... Air passage, 45 ... Frame, 46 ... Opening part, 47 ... Shielding plate, 50 ... Rib structure, 51,52 ... Partition rib, 53 ... Destination rib, 54 ... Notch, k, k1, k2 ... Air

Claims (8)

An image forming apparatus having a built-in fixing device and forming an image on a recording material using an electrophotographic method ,
An electronic component that is disposed in the vicinity of the fixing device and needs to be cooled to reduce the influence of heat received from the fixing device ;
An air guide means for guiding an air flow toward the fixing device and the electronic component;
Increasing the flow velocity of the air stream by disposed ribs structure such that a portion of the air flow is throttled guided by said baffle means, a flow rate changing means you cool the electronic component by the air stream in which the flow velocity is increased When,
A part of the air flow whose flow velocity is increased by the flow velocity changing means is directed to the fixing device, and the air flow toward the fixing device is divided while being guided by the air guiding device, and the flow velocity is changed by the flow velocity changing device. A flow velocity equalizing means for making the flow velocity substantially uniform by merging with an air flow that cannot be increased;
The including image forming apparatus. The air guide means guides a part of the air flow to the fixing device without passing through the flow speed changing means, and thereby constitutes a part of the flow speed equalizing means. The image forming apparatus according to claim 1 . An image forming apparatus having a built-in fixing device and forming an image on a recording material using an electrophotographic method ,
A forming section for taking in air outside the apparatus and forming a flow of air inside the apparatus;
And parts requiring cooling in order to reduce the effect of heat received from the fixing device,
Position, and a predetermined part of the overall air formed by the forming unit together with a stream of air formed by the forming unit directed to the part and the fixing device between the component and the forming unit a guide portion for directing the portion products to increase the flow rate of the air by disposed ribs structure as squeezed is,
Including
The forming part is
A wall portion disposed on the upstream side of the guide portion and hindering a flow of air taken into the apparatus ;
A ventilation part formed on the wall part or arranged adjacent to the wall part for guiding air to the guide part;
Equipped with a,
The wall portion of the forming portion is configured to convert air taken into the apparatus into air that is guided to the ventilation portion and air that is not guided to the ventilation portion and that is directed to the fixing device without being increased in flow velocity by the guide portion. And is divided into
A part of the air whose flow velocity is increased by the guide portion is directed to the fixing device, and the air flowing toward the fixing device is not increased by the guide portion divided by the wall portion of the forming portion. The image forming apparatus is characterized in that the flow velocity is made uniform to make the flow velocity substantially uniform. The ventilation portion is located in a direction deviating from the direction in which air flows by the forming portion,
The guide section includes a partition rib formed to guide a part of the air guided to the guide section by the ventilation section so as to go around in a direction opposite to the direction of deviation. The image forming apparatus according to claim 3 . The partition rib of the guide part is composed of a pair spaced apart from each other,
The guide portion further includes a destination rib arranged so that a flow path area is narrowed between the pair of partition ribs, and the destination rib is located closer to the downstream in the air flow direction. The image forming apparatus according to claim 4 . The image forming apparatus according to claim 5 , wherein the pair of partition ribs of the guide portion are arranged in a direction opposite to the forming portion with respect to the ventilation portion. The guide portion further includes a notch formed in the partition rib located on a side farther from the forming portion of the pair of partition ribs, and the notch is located upstream of the air flow direction. The image forming apparatus according to claim 5 , wherein: The image forming apparatus according to claim 3 , wherein a recording material conveyance path is located between the component and the guide portion.

Images