JP6308779B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus that forms an image on a sheet.

  In recent years, image forming apparatuses such as copiers, printers, and facsimiles using an electrophotographic system have become widespread. These image forming apparatuses are required to be able to output a plurality of types of sheets such as thin paper, thick paper, and coated paper while maintaining high productivity (the number of images formed per unit time). Furthermore, high durability that does not change the quality even after long-term use is required.

  Some image forming apparatuses have a suction hole for conveying a sheet on which unfixed toner is placed from the transfer unit to the fixing unit, and include a conveyance belt that sucks and conveys the sheet. (See Patent Documents 1 and 2).

JP 2008-203767 A JP 2011-123417 A

  Here, the conveyance belt may approach the sheet width direction that intersects the sheet conveyance direction. In order to prevent inconvenience caused by the approach of the conveyor belt, it is conceivable to provide a regulation wall (regulator) that regulates the deviation of the conveyor belt by contacting the end of the conveyor belt.

  When the regulation wall is provided, if the driving is continued in a state where the end of the conveyance belt is in contact with the regulation wall, the regulation wall is heated by frictional heat generated by friction between the conveyance belt and the regulation wall. On the other hand, since the toner is scattered in the vicinity of the transfer portion, the toner adhering to the conveyance belt accumulates on the regulation wall. When the rotation of the conveying belt is stopped, the toner adheres to the regulation wall due to the temperature rise of the regulation wall. If the toner adheres, the conveyor belt may stick to the regulation wall due to the toner, and if the conveyor belt adheres to the regulation wall, there is a risk of causing a malfunction when the rotation of the conveyor belt is resumed. Further, the dirt of the toner adhering to the regulation wall may be scattered when rubbing against the conveying belt, and may adhere to the sheet and cause an image defect.

  An object of the present invention is to prevent the temperature rise of the restricting portion while restricting the belt shift by the restricting portion.

The image forming apparatus of the present invention can suck air so as to flow through an image forming unit that forms an image on a sheet, a belt that conveys a sheet on which an image is formed by the image forming unit, and a suction hole of the belt , a first fan for causing adsorb the sheet to the belt, a sheet conveying device that includes a restricting portion for restricting a lateral shift of the belt in contact with the end of the belt, the regulating portion is provided It has a heat radiating member and the 2nd fan which generates the air flow blown toward the sheet conveyance device, and the heat radiating member is cooled by the air flow generated by the 2nd fan.

  According to the present invention, it is possible to prevent a malfunction caused by the temperature rise by preventing the temperature rise of the regulating portion that regulates the deviation of the belt.

1 is a diagram illustrating a schematic configuration of a high-speed monochrome printer that is an example of an image forming apparatus according to an embodiment of the present invention. Sectional drawing explaining the structure of a sheet conveying apparatus. The top view of a sheet conveying apparatus. The figure explaining the relationship of the force concerning the belt stretched around the crown-shaped part of the drive roller provided in the sheet conveying apparatus. 1 is a cross-sectional view of a sheet conveying apparatus according to a first embodiment of the present invention. EE sectional drawing of FIG. The schematic perspective view of the sheet conveying apparatus of the 1st Embodiment of this invention of a heat radiating member removal state. (A) is sectional drawing of the sheet conveying apparatus of the 2nd Embodiment of this invention. (B) is sectional drawing seen from the upper direction of the suction fan of the sheet conveying apparatus of the 2nd Embodiment of this invention. Sectional drawing of the sheet conveying apparatus of the 3rd Embodiment of this invention.

(First embodiment)
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram illustrating a schematic configuration of a high-speed monochrome printer that is an example of an image forming apparatus including a sheet conveying device according to an embodiment of the present invention. In FIG. 1, reference numeral 100 denotes a high-speed monochrome printer main body (hereinafter referred to as a printer main body).

  The printer main body 100 includes an image forming unit 106 (image forming unit) that forms an image on the sheet S, and a paper feeding unit 103 that feeds the sheet S to the image forming unit 106.

  The image forming unit 106 includes a photosensitive drum 1, a laser scanner unit 15 that forms a latent image on the photosensitive drum 1, a corona charger 2, a developing device 3 that stores toner and develops the latent image, and a primary transfer roller 6. In addition, a toner recovery device 5 and the like are provided. The photosensitive drum 1 is composed of a metal cylinder having a negatively charged photosensitive layer formed on the surface thereof, and rotates in the direction of the arrow R1.

  The image forming unit 106 includes an intermediate transfer belt 4 on which the toner image formed on the photosensitive drum 1 is primarily transferred, and a secondary transfer roller 7 for secondary transfer of the toner image on the intermediate transfer belt 4 to the sheet S. And are provided.

  The sheet feeding unit 103 includes a sheet storage unit 9 that stores sheets S, and a feeding member 10 a and a conveyance member 9 a that feed the sheets S stored in the sheet storage unit 9.

  Next, the operation of the printer main body 100 will be described.

  First, a laser beam corresponding to an image formed on the sheet S is irradiated from the laser scanner unit 15 onto the photosensitive drum 1 that has been charged in advance by the corona charger 2. Thereby, an electrostatic latent image is formed on the photosensitive drum. Next, the electrostatic latent image is developed by the developing device 3 to form a toner image on the photosensitive drum 1. The toner image formed on the photosensitive drum 1 is primarily transferred to the intermediate transfer belt 4 by the primary transfer roller 6 in the primary transfer portion T1.

  On the other hand, when a paper feed signal is output from the controller (not shown) to the paper feed unit 103, the sheet S is fed from the sheet storage unit 9 by the feeding member 10a. Thereafter, the fed sheet S is conveyed to the registration roller 16, and then the registration roller 16 matches the timing of the toner image on the intermediate transfer belt 4 with the intermediate transfer belt 4 and the secondary transfer roller 7. Are transported to a secondary transfer portion T2.

  Next, the toner image that has been primarily transferred onto the intermediate transfer belt 4 is transferred onto the sheet S sent to the secondary transfer portion T2. Thereafter, the sheet S is delivered from the secondary transfer portion T2 to the fixing device 17 as a fixing portion by the sheet conveying device 18 that adsorbs and conveys the sheet with an endless belt. The sheet S is heated and pressed by a fixing nip portion F1 including a pressure roller 19 and a fixing roller 20 in the fixing device 17 to fix the toner image on the surface, and then is discharged from the printer main body 100 by a discharge roller 105. The

  FIG. 2 is a cross-sectional view illustrating the configuration of the sheet conveying device 18 and its peripheral part. FIG. 3 is a plan view of the sheet conveying device 18.

  2 and 3, the sheet conveying device 18 includes four conveying belts 181 to 184 having innumerable holes (suction holes), a driving roller 18a on which the conveying belts 181 to 184 are stretched, and a driven Rollers 18b, 18c and 18d are provided. The four rollers 18a to 18d are rotatably supported by the front side plate 132 and the rear side plate 131. The conveyor belts 181 to 184 are elastic bodies, and by being pressed against the four rollers 18a to 18d by the tension, the drive transmission of the driving roller 18a is surely performed, and around the four rollers 18a to 18d. Rotate.

  Reference numeral 108 denotes a conveyance frame installed inside the conveyance belts 181 to 184. The conveyance frame 108 is made of a material having good thermal conductivity (for example, iron or aluminum). The front plate 132 and the rear plate 131 are supported by the transport frame 108. A suction fan 115 is installed inside the transport frame 108. The suction fan 115 generates an airflow that flows downward from above the conveyor belts 181 to 184 through the suction holes of the conveyor belts 181 to 184. When the sheet S is passed, the sheet S is adsorbed to the conveying belts 181 to 184 by air sucked by the suction fan 115 in the direction of arrow B in the drawing through the holes of the conveying belts 181 to 184. The suction fan 115 exhausts the sucked air to the back side of the image forming apparatus.

  A sheet detection sensor flag 190 as a rotation member is rotatably supported on the conveyance frame 108. As shown in FIG. 3, the sheet detection sensor flag 190 is disposed at the center in the sheet width direction intersecting the sheet conveyance direction. When the sheet detection sensor flag 190 is rotated by being pushed by a sheet conveyed in the sheet conveyance direction D, the sheet detection sensor 191 provided in the conveyance frame 108 outputs a signal indicating that the sheet has arrived. Based on a signal from the sheet detection sensor 191, a controller (not shown) of the image forming apparatus makes a JAM determination.

  In FIG. 2, a transfer outlet guide 101 is provided between the secondary transfer portion T2 and the sheet transport device 18 for stabilizing the sheet transport behavior of the sheet S that has passed through the secondary transfer portion T2. A fixing entrance guide 102 for stabilizing the behavior of the sheet S entering the fixing nip F1 of the pressure roller 19 and the fixing roller 20 rotating in the direction of arrow E between the sheet conveying device 18 and the fixing nip F1. Is provided.

  Drive from a drive motor (not shown) is transmitted to the drive roller 18a via the transmission belt 124, whereby the drive roller 18a rotates, and thereby the conveyor belts 181 to 184 move in the direction of arrow A in the figure. The sheet S is conveyed to the fixing device 17 by the conveying belts 181 to 184 while being sucked onto the conveying belts 181 to 184 by the air suction by the suction fan 115 and the movement of the conveying belts 181 to 184.

  The sheet conveying apparatus 18 including the conveying frame 108, the conveying belts 181 to 184, the suction fan 115, the driving roller 18a, and the driven rollers 18b, 18c, and 18d is unitized as a belt conveying unit. The unitized sheet conveying device 18 is removed (or pulled out) from the main body of the image forming apparatus, and maintenance (replacement of the sheet detection sensor 191 and the conveying belts 181 to 184) is performed.

  By the way, as shown in FIG. 4, the region where the conveyor belts 181 to 184 of the four rollers 18a to 18d are stretched has a crown shape. When the transport belt 181 and the rollers 18a to 18d are rotated, for example, as shown in FIG. 4, if the transport belt 181 is shifted to the left side from the central portion C of the crown shape, a force is applied to the transport belt as follows. That is, Fl> Fr, where Fl is the force that moves the region at the left end of the conveyor belt 181 inward, and Fr is the force that moves the region at the right end of the conveyor belt 181 inward. Fl> Fr is due to the fact that the tension of the conveyor belt works along the roller slope, and therefore a force that moves inwardly acts in a region where the amount applied to the slope is large. The force Fl (or Fr) is expressed as the product of the friction coefficient μ and the tension N between the conveying belt 181 and the rollers 18a to 18d. The force difference Fl-Fr becomes a force for moving the conveying belt 181 to the right side (center side), and the conveying belt 181 moves to the right side by this force difference Fl-Fr. Thereafter, when the conveyor belt 181 moves to the right side, the force difference Fl-Fr decreases and eventually becomes zero.

  Thus, when the force difference Fl-Fr becomes 0, that is, when the transport belt 181 moves to a position where Fl = Fr, the transport belt 181 stops moving in the width direction and becomes stable. This force Fl (= μN) for automatically aligning the conveyor belt to the center of the roller is referred to as automatic alignment force.

  As described above, by providing the rollers 18a to 18d with a crown shape, the conveyor belts 181 to 184 can be moved to the crown-shaped central portion C of the rollers 18a to 18d. Finally, when the axes of the driving roller 18a and the driven rollers 18b, 18c, and 18d are parallel, the conveyor belts 181 to 184 are stabilized at the center C of the crown shape of the four rollers 18a to 18d.

  However, there are cases where the axes of the rollers 18a to 18d are low due to variations in processing of the transport frame 108, variations in assembly of the transport frame 108 with the front side plate 132 and the rear side plate 131, and the like. In this case, individual differences occur at the alignment positions where the conveyor belt 181 is stable. In addition, due to variations in heat in the manufacturing process of the conveyor belt 181 and variations in the dimensions of the mold, variations in the circumference and tension of the conveyor belt 181 occur, and individual differences occur in the alignment position due to these causes. . Further, the conveyor belt 181 is stretched around the four rollers 18a to 18d and repeats the rotation around the four rollers, so that plastic elongation occurs, and the circumferential length and tension change. Further, since the scattered toner and paper powder are sucked by the suction fan 115, the scattered toner and paper powder adhere between the conveying belts 181 to 184 and the rollers 18a to 18d. When scattered toner or paper powder adheres between the conveyor belts 181 to 184 and the rollers 18a to 18d, the friction coefficient μ between the conveyor belts 181 to 184 and the rollers 18a to 18d decreases. Since the friction coefficient μ between the conveyor belts 181 to 184 and the rollers 18a to 18d decreases and the automatic alignment force Fl decreases, the alignment position of the conveyor belt is difficult to stabilize.

  As a result, the conveyance belt approaches either direction in the sheet width direction. For example, if the end of the conveyance belts 182 and 183 contacts the sheet detection sensor flag 190 and rotates the sheet detection sensor flag 190, an erroneous JAM is performed. In the present embodiment, the belt is stretched by four rollers, but the same phenomenon can occur in a sheet conveying device stretched by two or more rollers.

  In order to prevent the deviation of the conveyor belts 181 to 184, it is conceivable to provide a regulating wall that contacts the conveyor belts 181 to 184 and regulates the deviation of the belt. When the restriction wall is provided, the temperature of the restriction wall rises due to friction with the conveyor belt when the belt shift occurs. When the temperature of the regulation wall rises, for example, the following problems may occur.

  That is, the toner scattered in the machine adheres to the regulation wall, and the adhered toner acts like an adhesive, and the conveying belt sticks to the regulation wall. When the conveyance belt sticks to the regulation wall, the rotation operation of the conveyance belt is defective. In addition, the frictional resistance increases due to the adhesion of the toner, the conveying belt is scraped, and scraped powder is generated. The shaving powder adheres to the sheet and contaminates the image. Further, the generation of scraping powder causes the conveyance belt to wave, causing the sheet behavior to become unstable, adversely affecting toner transfer, and possibly causing JAM. In addition, if scraping occurs, the life of the transport belt is shortened, and the transport belt is torn and cannot be transported.

  Therefore, in order to prevent the temperature rise of the regulation wall while regulating the shift of the conveyor belt by the regulation wall, the present embodiment has the following configuration.

  FIG. 5 is a schematic cross-sectional view of the sheet conveying apparatus 18 and its peripheral portion showing the first embodiment of the present invention. 6 is a cross-sectional view taken along the line EE in FIG. FIG. 7 is a perspective view of the sheet conveying device 18 as viewed from below.

  The regulation wall 300a shown in FIGS. 5 to 7 is in contact with the ends of the conveyance belts 182 and 183, thereby restricting the conveyance belts 182 and 183 from moving in the sheet width direction.

  As shown in FIG. 5, below the sheet conveying device 18, a cooling fan (as an external fan) 116 is disposed as a blowing unit that sends the wind W toward the sheet conveying device 18. A heat radiating member 300 is disposed in the air flow generated by the cooling fan 116 so that the wind W from the cooling fan 116 is applied to the transport frame 108.

  And the regulation wall (regulation part) 300a is provided in the heat radiating member 300 ventilated by the cooling fan 116. The material of the heat dissipating member 300 is preferably a metal having good thermal conductivity (for example, iron or aluminum having a thermal conductivity of 10 [W / mK] or more).

  As shown in FIGS. 6 and 7, the regulation wall 300 a is arranged to regulate the central two conveyor belts 182 and 183 in the sheet width direction from approaching the center side. As shown in detail in FIG. 6, the position of the regulation wall 300a in the sheet width direction is the initial state, the belt end position in a state where the conveying belts 182 and 183 are balanced by the above-described automatic alignment force, and the sheet detection. It arrange | positions between the width direction end surfaces of the sensor flag 190 (F in the figure). With this arrangement, it is possible to prevent the conveyance belts 182 and 183 from moving to the area of the sheet detection sensor flag 190 and the conveyance belts 182 and 183 rotating the sheet detection sensor flag 190. Therefore, erroneous JAM determination due to the conveyance belts 182 and 183 rotating the sheet detection sensor flag 190 is prevented.

  As shown in FIG. 7, the heat dissipating member 300 provided with the regulation wall 300 a is detachable from the transport frame 108 of the sheet transport device 18, and is fixed to the transport frame 108 with screws 309. The heat dissipating member 300 is detachably disposed on the transport frame 108 without removing the transport belts 181, 182, 183, and 184 from the sheet transport apparatus 18.

As shown in FIG. 6, the heat dissipation member 300 includes a guide portion 300 b that guides the wind so that the suction fan 115 in the sheet conveying device 18 can be cooled by the wind from the cooling fan 116 as an external fan. ing. That is, the guide unit 300 b guides the wind from the cooling fan 116 to the inside of the sheet conveying device 18.
The operation and effect of the above configuration will be described below.

  By using a metal having good thermal conductivity as the heat radiating member 300, the thermal conductivity from the location (guide part 300b) where the wind from the cooling fan 116 is applied to the regulating wall 300a where frictional heat is generated is improved. The heat generated in 300a can be easily dissipated. As a result, even if the conveyor belts 182 and 183 rub against the regulation wall 300a, it is possible to prevent toner or belt shaving powder from adhering to the regulation wall due to a temperature rise due to frictional heat. As a result, it is possible to prevent malfunction of the transport belts 182 and 183 due to the adhered toner and belt scraping powder.

  The wind W from the cooling fan 116 is guided into the sheet conveying device 18 by the guide unit 300b. Therefore, the cooling fan 116 cools the components inside the sheet conveying device 18 that sucks air in the vicinity of the fixing device 17 that generates heat. Since the inside of the sheet conveying device 18 is cooled, it is possible to prevent the electrical component (suction fan 115) arranged in the sheet conveying device 18 from malfunctioning due to excessive temperature rise. Since the wind W from the cooling fan 116 is guided into the sheet conveying device 18 by the guide portion 300b of the heat radiating member 300, the cooling fan 115 cools the suction fan 115 of the sheet conveying device 18 and promotes the heat radiation of the heat radiating member 300. 116 also serves.

  Here, the suction fan 115 is illustrated as an electrical component to be cooled by the cooling fan 116, but wind may be guided to the sheet detection sensor 191 in order to cool the sheet detection sensor 191, for example.

  Further, as described with reference to FIG. 7, the heat dissipating member 300 is detachably disposed on the sheet conveying device 18 without removing the conveying belts 181, 182, 183, 184 of the sheet conveying device 18 from the sheet conveying device 18. Yes. Since the heat radiating member 300 can be removed without removing it from the sheet conveying device 18, it is easy to replace an electrical component (for example, the sheet detection sensor 191) disposed in the sheet conveying device 18. That is, by removing the heat radiating member 300 from the sheet conveying device 18, the sheet detection sensor 191 can be replaced without removing the conveying belt.

  In the present embodiment, the regulation wall 300a is provided between the conveyor belts 182, 183, but may be disposed at any position between the conveyor belts 181, 182, 183, 184. At this time, a duct for the cooling fan 116 may be formed so that the wind from the cooling fan 116 strikes the heat radiating member 300.

  In order to suppress the generation of frictional heat between the heat dissipating member 300 and the conveyor belts 182 and 183, the following configuration may be used. The heat dissipating member 300 is thin (for example, 0. 2 mm thick) A resin sheet material is disposed. In other words, a sheet material having a lower friction coefficient with the conveyor belts 182 and 183 than the heat radiating member 300 is attached to the regulation wall 300a, and the regulation wall 300 and the sheet material constitute a regulation unit. Alternatively, the contact surface of the regulation wall 300a with the ends of the conveyor belts 182 and 183 is plated so that the friction coefficient is lowered. Thus, the frictional resistance between the ends of the conveyor belts 182 and 183 and the regulation wall 300a is lowered. As a result, the frictional heat generated without reducing the thermal conductivity can also be suppressed, so that the output of the fan for cooling can be suppressed and a power-saving image forming apparatus can be provided.

(Second Embodiment)
FIG. 8A is a cross-sectional view of the sheet conveying apparatus showing the second embodiment. FIG. 8B is a cross-section viewed from above the suction fan of the sheet conveying apparatus of the second embodiment.

  The metal heat dissipating member 300 provided with the regulating wall 300a is disposed in the air flow generated by the suction fan 115 as the air blowing means so that the wind W from the suction fan 115 disposed in the sheet conveying device 18 is hit. Has been. Specifically, the heat dissipating member 300 is arranged so that the heat sucking member 300 hits the wind W (exhaust flow) when the air sucked from above the conveying belts 181 to 184 by the suction fan 115 is discharged from the suction fan 115. Yes.

  In the image forming apparatus in which the temperature of the wind W sucked by the suction fan 115 is low (for example, 40 ° C. or less), by using the wind W generated by the suction fan 115 for heat radiation, it is possible to prevent the temperature rise of the regulation wall 300a. it can. As a result, it is not necessary to provide a cooling fan outside the sheet conveying apparatus 18 as in the first embodiment, which leads to a reduction in the number of parts, and image formation that not only suppresses the conveyor belt but also reduces costs. Equipment can be provided.

  In the first and second embodiments described above, the heat dissipation member 300 is attached to the conveyance frame 108 that supports the conveyance belts 182 and 183 via rollers. Therefore, the positional accuracy in the width direction of the heat radiating member 300 having the regulating wall 300a is increased, and the heat generated in the regulating wall 300a is radiated while accurately regulating the position of the end of the conveyor belt when the belt is offset. It becomes possible.

  In addition, although the fan (what generate | occur | produces an airflow when a wing | blade rotates) was illustrated as a ventilation means, if it sends a wind to a heat radiating member, it will not be restricted to the thing provided with the wing | blade.

(Third embodiment)
FIG. 9 is a diagram illustrating a third embodiment. A regulation wall 301a for regulating the deviation of the conveyance belts 182 and 183 in the sheet width direction is provided in a metal duct 301 for regulating the air path of the cooling fan 116 outside the sheet conveyance device 18. A metal duct (heat radiating member) 301 provided with a regulating wall 301a is provided in the main body of the image forming apparatus provided with the sheet conveying device 18 in a detachable manner.

  By doing so, it is possible to save the trouble of removing the member provided with the restriction wall at the time of maintenance (replacement of the suction fan due to accidental failure or replacement of the conveyor belts 181, 182, 183, 184 due to deterioration of the service life). That is, when the unitized sheet conveying device 18 is removed from the main body of the image forming apparatus, the sheet is separated from the metal duct 301 provided with the regulating wall 301a. Therefore, the maintenance work can be saved compared with the first and second embodiments in which the heat radiating member 300 is removed from the sheet conveying device 18 and the maintenance is performed.

  In the present embodiment, the anti-scattering wall 302 is provided on the lower side of the regulating wall 301a in the direction of gravity. The scattering prevention wall 302 prevents scattering toner that accumulates and falls on the regulation wall 301a from scattering. Due to the scattering prevention wall 302, it is possible to prevent dirt such as in-machine scattering toner that has accumulated on the regulation wall 301a without adhering to the sheet from being scattered in the sheet conveyance path and attached to the medium, resulting in an image defect. Since toner scattering is prevented, the number of cleaning parts can be reduced. As a result, not only the deviation of the conveying belt can be suppressed, but also the cleaning time can be shortened, and a highly durable sheet conveying apparatus 18 can be realized.

1, 3, 4, 6, 15 Image forming unit 18 Sheet conveying device 108 Conveying frame 108a, 108b Suction hole 115 Suction fan 116 Cooling fan 181, 182, 183, 184 Conveying belt 190 Sheet detection sensor flag 191 Sheet detection sensor S Sheet T2 transfer section (secondary transfer section)
300, 301 Heat-dissipating member 300a, 301a Restriction wall 300b Air passage guide part 302 Anti-scattering wall D Sheet conveyance direction

Claims (10)

Image forming means for forming an image on a sheet;
And includes a belt for conveying the sheet on which an image is to be formed, can suck the air to flow suction holes of said belt, first a fan for causing adsorb the sheet to the belt, the by said image forming means A sheet conveying device;
A restricting portion for restricting the deviation of the belt by contacting the end of the belt;
A heat dissipating member provided with the restricting portion;
A second fan that generates an airflow blown toward the sheet conveying device,
The image forming apparatus, wherein the heat radiating member is cooled by an air flow generated by the second fan.   The image forming apparatus according to claim 1, wherein the heat radiating member includes a guide portion that guides wind from the second fan to the first fan. The sheet conveying device has a sensor to detect a sheet conveyed by the belt,
3. The image forming apparatus according to claim 1, wherein the heat radiating member includes a guide portion that guides air from the second fan to the sensor. 4. Image forming means for forming an image on a sheet;
A sheet conveying device that includes a belt having suction holes and conveys a sheet on which an image is formed by the image forming unit;
A fan for generating an air flow toward the sheet conveying device;
A restricting portion for restricting the deviation of the belt by contacting the end of the belt;
A heat radiating member provided with the restricting portion and blown by the fan;
A sensor provided in the sheet conveying device for detecting a sheet conveyed by the belt ;
The image forming apparatus according to claim 1, wherein the heat radiating member includes a guide unit that guides air from the fan to the sensor.   5. The image forming apparatus according to claim 1, wherein the heat radiating member is detachably disposed on the sheet conveying apparatus without removing the belt from the sheet conveying apparatus. 6. apparatus.   The sheet conveying apparatus includes a frame that is disposed inside the belt, supports the belt via a roller on which the belt is stretched, and the heat dissipation member is attached to the frame. Item 6. The image forming apparatus according to any one of Items 1 to 5.   The image forming apparatus according to claim 1, wherein the heat radiating member is attached to a main body of an image forming apparatus that supports the sheet conveying apparatus.   The sheet conveying device has a rotating member that is pushed and rotated to detect a sheet conveyed by the belt, and the restricting unit is configured to prevent the belt from contacting the rotating member. The image forming apparatus according to claim 1, wherein the shift is regulated.   The image forming apparatus according to claim 1, wherein the heat radiating member is a metal. The image forming unit includes a transfer unit that transfers toner to a sheet, and a fixing unit that fixes the toner transferred to the sheet by the transfer unit to the sheet,
The image forming apparatus according to claim 1, wherein the sheet conveying device conveys a sheet from the transfer unit to the fixing unit.

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