JP7292966B2 - image forming device - Google Patents

Description

The present invention relates to an image forming apparatus such as a printer or copier using an electrophotographic method.

2. Description of the Related Art Conventionally, image forming apparatuses such as printers and copiers using an electrophotographic method are known to have a configuration in which a cleaning device is provided to remove toner remaining on an intermediate transfer belt. In the cleaning device disclosed in Patent Document 1, the toner remaining on the intermediate transfer belt is scraped off with a cleaning blade, and the scraped toner is transported by the rotating operation of the transport screw.

In such electrophotographic image forming apparatuses, the melting point of toner is being lowered in order to increase the productivity of image printing. Therefore, when the temperature of the toner transport path inside the cleaning device reaches a high temperature, the waste toner removed by cleaning tends to cause troubles such as poor toner transport and toner adhesion in the transport path. Therefore, in Japanese Patent Application Laid-Open No. 2002-100001, a cooling airflow path is arranged near the toner transport path inside the cleaning device to suppress the temperature rise of the toner transport path and prevent the occurrence of transport failure.

As another solution, there is a configuration in which a temperature sensor is arranged in the toner conveying path inside the cleaning device so that the toner can be reliably conveyed.

JP 2014-167507 A

However, in the technique disclosed in Japanese Patent Application Laid-Open No. 2002-200013, the configuration in which the cooling airflow path is provided inside the image forming apparatus leads to an increase in the size of the apparatus.

Further, in the configuration in which the temperature sensor is arranged in the toner conveying path, it is difficult to stably detect the temperature of the toner conveying path due to the influence of changes in temperature distribution due to heat generation.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to reliably transport the removed toner after transfer without increasing the size of the apparatus.

A representative configuration of the present invention for achieving the above object is an image carrier, and transfer means provided opposite to the image carrier for transferring a toner image formed on the image carrier to a sheet. a cleaning means for removing toner remaining on the image carrier after the toner image formed on the image carrier is transferred onto a sheet; and a container for storing the toner removed from the image carrier by the cleaning means. and fixing means for fixing the toner image transferred onto the sheet onto the sheet, wherein the cleaning means is provided between the image carrier and the fixing means, wherein the cleaning means a cleaning member that removes toner from a carrier; a toner conveying member that conveys the toner removed by the cleaning member to the container ; and a frame that supports the cleaning member and the toner conveying member , A shielding member is provided between the frame and the fixing device, and a temperature sensor for detecting temperature is provided on the cleaning device side of the shielding member.

According to the present invention, it is possible to reliably transport the removed toner after transfer without increasing the size of the apparatus.

Cross-sectional view of an image forming apparatus Schematic perspective view of transfer belt unit Right side perspective view of transfer belt unit Cross-sectional view of transfer belt cleaning device Left perspective view of transfer belt cleaning device Cross-sectional view of transfer belt cleaning device Left perspective view of transfer belt cleaning device Right side perspective view of transfer belt cleaning device Cross-sectional view of the fixing unit, shielding plate, and transfer belt cleaning device Top view of shield plate and transfer belt cleaning device Bottom perspective view of shielding plate, transfer belt cleaning device, and temperature sensor substrate Cross-sectional view of the shield plate, transfer belt cleaning device, transfer belt unit, and temperature sensor substrate Left front view of the shield plate, transfer belt cleaning device, and temperature sensor board

Preferred embodiments of the present invention will be exemplarily described in detail below with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in the following embodiments should be appropriately changed according to the configuration of the device to which the present invention is applied and various conditions. They are not intended to limit the scope of the invention only to them.

(Description of schematic configuration of entire image forming apparatus)
A schematic configuration of the image forming apparatus will be described with reference to FIG. FIG. 1 is a sectional view of an electrophotographic color image forming apparatus of an intermediate transfer system.

As shown in FIG. 1, the image forming apparatus 10 includes drum-shaped electrophotographic photosensitive members (hereinafter referred to as photosensitive drums) 1a to 1d. The photosensitive drums 1a to 1d are rotationally driven at a predetermined peripheral speed.

The photosensitive drums 1a to 1d are uniformly charged to predetermined polarities and potentials by the charging rollers 2a to 2d during this rotation process, and then subjected to image exposure by the image exposure means 3. FIG. As a result, an electrostatic latent image corresponding to the color component image of the desired color image is formed on each of the photosensitive drums 1a to 1d. Next, the electrostatic latent images formed on the respective photosensitive drums 1a-1d are developed by developing units 4a-4d at respective developing positions, and visualized as toner images.

The intermediate transfer belt 5, which is an image bearing member, is an endless belt, stretched by a plurality of stretching members (a driving roller 6, a tension roller 7, and a driven roller 8), and extends in the direction of arrow X in FIG. ∼ 1d are rotationally driven at substantially the same peripheral speed. The toner images formed on the photosensitive drums 1a to 1d are transferred to the primary transfer rollers 9a to 9d in the process of passing through the contact portion (hereinafter referred to as primary transfer nip) between the photosensitive drums 1a to 1d and the intermediate transfer belt 5. It is transferred to the intermediate transfer belt 5 by the applied primary transfer voltage (primary transfer). The primary transfer residual toner remaining on the photosensitive drums 1a to 1d after the primary transfer is cleaned and removed by the cleaning devices 11a to 11d, and then subjected to the image forming process again.

In this manner, toner images of four colors are formed and sequentially superimposed and transferred onto the intermediate transfer belt 5 to obtain a composite color image corresponding to the desired color image.

The four-color toner image on the intermediate transfer belt 5 is transferred to the secondary transfer roller 12 in the process of passing through a transfer portion (secondary transfer nip) where the intermediate transfer belt 5 and the secondary transfer roller 12 serving as transfer means face each other. By the applied secondary transfer voltage, the image is collectively transferred onto the sheet S fed by the feeding means 13 (secondary transfer). After that, the sheet S bearing the four-color toner image is introduced into a fixing device 14 as fixing means, where the four-color toners are melted and mixed by being heated and pressurized to be fixed on the sheet S. FIG. A full-color print image is formed on the sheet S by the above operation.

Secondary transfer residual toner remaining on the intermediate transfer belt 5 after the secondary transfer is cleaned and removed by a transfer belt cleaning device 15 as cleaning means.

(Description of transfer belt unit)
Next, the transfer belt unit 17 will be described with reference to FIGS. 2 and 3. FIG. FIG. 2 is a perspective view showing an outline of the transfer belt unit 17. As shown in FIG. FIG. 3 is a partial perspective view of the transfer belt unit as viewed in the direction of arrows YY in FIG. Note that the right support plate 40 is not shown in FIG. 3 for the sake of explanation.

As shown in FIG. 2, the intermediate transfer belt 5 as an image carrier, the transfer belt cleaning device 15 as cleaning means, and the toner storage container 27 as a storage unit are a transfer belt detachable from the image forming apparatus 10. It is integrally provided as a unit 17 . The transfer belt unit 17 will be described in detail below.

In the following description, the direction of the arrow Y is the axial direction of the center of rotation of the intermediate transfer belt 5, which is an image carrier. It is the axial direction that is the center of rotation of the roller 6 . The arrow X direction is a direction orthogonal to the arrow Y direction, and is a direction orthogonal to the axial direction of the rotation center of the driving roller 6 . The arrow Z direction is a direction orthogonal to the arrow X direction and the arrow Y direction, and is the vertical direction here.

The transfer belt unit 17 stretches and supports the intermediate transfer belt 5 with three stretching rollers, a drive roller 6 , a tension roller 7 and a driven roller 8 .

The drive roller 6 is rotatably supported by the right support plate 40 and the left support plate 41 at both ends in the arrow Y direction, and receives a predetermined rotational driving force from the apparatus main body at the end on the right support plate 40 side. It is designed to rotate. Hereinafter, the right support plate 40 side on one side in the arrow Y direction is called the right side, and the left side support plate 41 side on the other side in the arrow Y direction is called the left side.

The tension roller 7 uses a metal rod made of aluminum, and is stretched in the direction of arrow X by compression springs (not shown) arranged at both ends of the roller so as to apply a predetermined tension to the intermediate transfer belt 5 . ing.

The driven roller 8 uses an aluminum metal rod like the tension roller 7, and is rotatably supported by the right support plate 40 and the left support plate 41 at both ends in the arrow Y direction.

The right support plate 40 and the left support plate 41 are made of sheet metal, and support the drive roller 6, the tension roller 7 and the driven roller 8 so as to be rotatable as described above. In addition, the right support plate 40 and the left support plate 41 position and support the transfer belt cleaning device 15 as cleaning means and the toner container 27 as a container. A primary transfer roller support (not shown) is arranged between the right support plate 40 and the left support plate 41 to support the primary transfer rollers 9a to 9d. A primary transfer roller support (not shown) is positioned and supported by the right support plate 40 and the left support plate 41 . In this way, the primary transfer roller support (not shown), the transfer belt cleaning device 15, and the toner storage container 27 are positioned and supported by the right support plate 40 and the left support plate 41, thereby forming the transfer belt unit 17. retains its rigidity.

The transfer belt cleaning device 15 is cleaning means for removing toner remaining on the intermediate transfer belt 5 which is the image bearing member after transfer, and stores and conveys secondary transfer residual toner remaining on the surface of the intermediate transfer belt 5 . It has mechanism. As described above, the transfer belt cleaning device 15 is positioned and supported by the right support plate 40 and the left support plate 41 . Details of the transfer belt cleaning device 15 will be described later.

The toner storage container 27 is a storage unit that stores toner removed from the intermediate transfer belt 5 by the transfer belt cleaning device 15 . The toner storage container 27 is made of a resin material, is arranged inside the intermediate transfer belt 5, and is positioned and supported by the right side support plate 40 and the left side support plate 41 at both ends in the arrow Y direction.

The toner removed from the intermediate transfer belt 5 by the transfer belt cleaning device 15 is accommodated in the transfer belt cleaning device 15 and transported to a toner discharge path 26c provided on the right side of the transfer belt cleaning device 15 as shown in FIG. be done. After that, the toner is finally stored in the toner storage container 27 through an inlet 27 a provided on the right side of the toner storage container 27 . The toner discharge path 26c of the transfer belt cleaning device 15 and the entrance 27a of the toner storage container 27 are sealed with a transport path cover 70 to prevent toner from leaking from the inside.

The toner storage container 27 has detection means (not shown) such as an optical sensor for detecting that the toner in the container is full. The image forming apparatus 10 has a control section (not shown) that controls the operation of the entire apparatus. When the detection means detects that the toner storage container 27 is full, the user is notified that the toner storage container 27 is full. It notifies that the container 27 needs to be replaced. The toner storage container 27 and the transfer belt cleaning device 15 are integrally replaced as the transfer belt unit 17 .

(Description of transfer belt cleaning device)
Next, the transfer belt cleaning device 15 will be described with reference to FIGS. 4 and 5. FIG. FIG. 4 is a sectional view of the transfer belt cleaning device 15. As shown in FIG. 5 is a left perspective view of the transfer belt cleaning device 15. FIG. FIG. 5 is an explanatory diagram of only the left side of the transfer belt cleaning device 15, but since the right side has the same configuration, the illustration is omitted.

As shown in FIG. 4, the transfer belt cleaning device 15 cleans the intermediate transfer belt 5 downstream in the rotation direction of the intermediate transfer belt 5 from the transfer portion where the intermediate transfer belt 5 and the secondary transfer roller 12 (see FIG. 1) face each other. 5 are provided opposite to each other. The transfer belt cleaning device 15 has a cleaning blade 20 as a cleaning member and a cleaning frame unit 26 as a frame unit. The cleaning blade 20 is a cleaning member that removes secondary transfer residual toner remaining on the intermediate transfer belt 5 after transfer from the intermediate transfer belt 5 . The cleaning frame unit 26 is a frame unit that forms a space for conveying the toner removed from the intermediate transfer belt 5 by the cleaning blade 20 to the toner storage container 27 .

The cleaning blade 20 is made of elastic urethane rubber and adhered to a blade holding metal plate 21 . The cleaning blade (urethane rubber) 20 has a width in the longitudinal direction equal to or greater than the maximum size of a sheet on which an image can be formed by the main body of the image forming apparatus. Remove.

In order to reliably remove residual toner remaining on the intermediate transfer belt 5 after the secondary transfer, it is necessary to press the cleaning blade 20 against the intermediate transfer belt 5 with a predetermined pressure. Therefore, a rigid member is provided at a position facing the cleaning blade 20 . In this embodiment, the rigid member is the drive roller 6 which is one stretching member for stretching the intermediate transfer belt 5 . The cleaning blade 20 is positioned downstream of a facing portion (secondary transfer portion) where the intermediate transfer belt 5 and the secondary transfer roller 12 face each other in the rotation direction of the intermediate transfer belt 5 , and is positioned above the drive roller 6 . is placed in contact with the

As shown in FIG. 5, at both ends of the blade holding sheet metal 21 in the direction of the arrow Y, there are holes 21a for rotatably supporting the cleaning blade 20 and pressurizing holes 21a for pressing the cleaning blade 20 against the intermediate transfer belt 5. A spring hooking portion 21b for hooking the spring 45 is provided. The cleaning blade 20 is rotatably engaged with metal blade support shafts 40a and 41a crimped to the right support plate 40 and the left support plate 41 through holes 21a at both ends of the blade holding plate 21. , are supported so as to be able to come into contact with and separate from the intermediate transfer belt 5 . A pressure spring (tension spring) 45 is stretched between the spring hooking portion 21b of the blade holding sheet metal 21 and the case spring hooking portion 26b arranged on the cleaning frame unit 26. As shown in FIG. The pressure spring 45 generates a rotational moment around the blade support shaft 40a (41a), and the cleaning blade 20 is pressed against the intermediate transfer belt 5 with a predetermined pressure.

(Description of toner transport)
Next, toner conveyance in the transfer belt cleaning device will be described with reference to FIGS. 6 to 8. FIG. FIG. 6 is a sectional view of the transfer belt cleaning device 15. As shown in FIG. FIG. 7 is a left perspective view of the transfer belt cleaning device 15. FIG. In FIG. 7, the cleaning frame unit 26 is not shown for explanation. 8 is a right perspective view of the transfer belt cleaning device 15. FIG. A part of the cleaning frame unit 26 is not shown in FIG. 8 for the sake of explanation.

As shown in FIG. 6, the transfer belt cleaning device 15 includes a cleaning blade 20 that removes toner from the intermediate transfer belt 5, and a cleaning frame that forms a space for conveying the toner removed by the cleaning blade 20 to a toner storage container 27. a body unit 26;

The cleaning frame unit 26 is made of a resin member and has a space inside. The space inside the cleaning frame unit 26 includes a toner storage section 26m that temporarily stores toner removed from the intermediate transfer belt 5 by the cleaning blade 20, and a toner storage section 26m that stores the stored toner in the longitudinal direction of the cleaning blade 20 (arrow Y direction) and a toner conveying portion 26n for conveying the toner.

As shown in FIG. 7, the toner containing portion 26m has a rotating shaft 25 on which a flexible agitating sheet member 24 having a thickness of about 80 μm is arranged over the entire longitudinal direction. A third gear 52 for driving is arranged. The rotating shaft 25 rotates clockwise in FIG. 4 by sequentially transmitting driving force from a first gear 50 arranged on the shaft of the drive roller 6 and a second gear 51 which is an idler gear. The toner removed from the intermediate transfer belt 5 by the cleaning blade 20 gradually begins to accumulate around the cleaning blade 20, and is supplied to the toner conveying portion 26n while being agitated by the agitating sheet member 24. The toner conveying portion 26n includes a toner conveying screw 23 that conveys the toner supplied by the stirring sheet member 24 in the longitudinal direction of the cleaning blade 20 (direction of arrow Y). The toner conveying screw 23 has a driving fourth gear 53 at its left end in the longitudinal direction, and rotates by meshing with a third gear 52 driving the rotating shaft 25 having the stirring sheet member 24 .

As shown in FIG. 8, the toner conveyed in the direction of arrow Y through the toner conveying portion 26n by the toner conveying screw 23 reaches the toner discharge path 26c. Here, the toner discharge path 26c is formed with a slope angle equal to or greater than the angle at which the toner falls by its own weight. Therefore, the toner transported to the toner discharge path 26c drops into the inlet 27a of the toner storage container 27 due to its own weight.

The toner entering the inlet 27a and contained in the toner container 27 is efficiently transferred to the inside of the toner container 27 by a toner diffusion member (not shown) such as a screw or paddle arranged inside the toner container 27. be filled.

(Description of the shield plate)
Next, the shield plate will be described with reference to FIGS. 9 and 10. FIG. FIG. 9 is a sectional view of the fixing device 14, shielding plate 35 and transfer belt cleaning device 15. As shown in FIG. 10 is a top view of the shielding plate 35 and the transfer belt cleaning device 15. FIG.

As described above, the transfer belt cleaning device 15 has an inner space surrounded by the cleaning frame unit 26 (a space divided into the toner storage portion 26m and the toner transport portion 26n). Hereinafter, the space inside the cleaning frame unit 26 in the transfer belt cleaning device 15 will be referred to as a toner storage/conveyance path. When the temperature of the toner containing and conveying path, which is the inner space surrounded by the cleaning frame unit 26, rises above a predetermined temperature due to the heat generated by the fixing device 14, the toner in the toner containing and conveying path melts. Further, when the heat generation of the fixing device 14 disappears and the temperature of the toner containing and conveying path falls below a predetermined temperature, the melted toner in the toner containing and conveying path solidifies.

When the solidified toner adheres to the cleaning blade 20, the secondary transfer residual toner on the intermediate transfer belt 5 cannot be sufficiently removed by the cleaning blade 20, resulting in image defects. Further, when the solidified toner adheres to the rotating shaft 25 and the sliding portion of the toner conveying screw 23 , the rotating shaft 25 and the toner conveying screw 23 do not rotate, and the toner in the toner containing conveying path cannot be conveyed to the toner containing container 27 . . Therefore, it is necessary to prevent the toner in the toner containing and conveying path from melting.

The transfer belt cleaning device 15 is arranged at a position facing the driving roller 6 and is arranged at a position close to the fixing device 14 . That is, the transfer belt cleaning device 15 faces the intermediate transfer belt 5 on the downstream side in the rotation direction of the intermediate transfer belt 5 from the transfer portion where the intermediate transfer belt 5 and the secondary transfer roller 12 (see FIG. 1) face each other. is provided. The fixing device 14 as fixing means is arranged so that the transfer belt cleaning device 15 is positioned between the intermediate transfer belt 5 and the fixing device 14 . Therefore, there is a concern that the temperature of the toner containing and conveying path may rise due to the heat of the fixing device 14 . In order to prevent this, as shown in FIG. 9, a shielding plate 35 as a shielding member is arranged between the fixing device 14 and the transfer belt cleaning device 15 so that the heat of the fixing device 14 is directly transmitted to the transfer belt cleaning device 15. prevent

As shown in FIG. 10 , the shielding plate 35 as a shielding member has the entire area in the direction of the arrow X and the direction of the arrow Y when the shielding plate 35 is viewed from above (the side of the fixing device 14 that is the side of the fixing means). It is arranged so as to cover the belt cleaning device 15 .

The shielding plate 35 is made of metal. Here, the shielding plate 35 is made of sheet metal, and both ends in the direction of the arrow Y are welded and fixed to the right side plate 60 and the left side plate 61, which are the body frame of the image forming apparatus. Thereby, the shielding plate 35 also plays a role of a rigid member as the body frame.

(Explanation of temperature sensor)
Next, the temperature sensor will be explained with reference to FIGS. 11 to 13. FIG. 11 is a bottom perspective view of the shielding plate 35, the transfer belt cleaning device 15 and the temperature sensor substrate 30. FIG. FIG. 12 is a cross-sectional view of the shielding plate 35, the transfer belt cleaning device 15, the transfer belt unit 17, and the temperature sensor substrate 30. FIG. 13 is a left front view of the shielding plate 35, the transfer belt cleaning device 15 and the temperature sensor substrate 30. FIG.

As described above, in this embodiment, the shielding plate 35 is arranged between the fixing device 14 and the transfer belt cleaning device 15 to prevent the heat of the fixing device 14 from being directly transmitted to the transfer belt cleaning device 15. there is

However, depending on the usage conditions, there is a concern that the temperature of the toner containing and conveying path, which is the space inside the transfer belt cleaning device 15, rises above a predetermined temperature and the toner melts. In order to prevent this, a temperature sensor 30a is arranged to monitor the ambient temperature in the vicinity of the toner containing and conveying path, and the temperature of the toner containing and conveying path is controlled so as not to exceed a predetermined temperature. Specifically, a control unit (not shown) that controls the operation of the image forming apparatus controls the operating state (for example, productivity) of the image forming apparatus so that the temperature detected by the temperature sensor 30a does not exceed a predetermined temperature. controlling.

As described above, in order to prevent the temperature of the toner storage path, which is the space inside the transfer belt cleaning device 15, from exceeding a predetermined temperature, it is necessary to measure the temperature closer to the temperature of the toner storage path. be. Therefore, the relationship among the temperatures of the fixing device 14, the temperature sensor 30a, and the toner containing/conveying path must be: fixing device 14>temperature sensor 30a≧remaining toner containing/conveying path.

As described above, the shielding plate 35 is arranged between the fixing device 14 and the transfer belt cleaning device 15 . As a result, in the initial operation state of the image forming apparatus, the temperature distribution inside the shielding plate 35 (on the side of the fixing device 14 ) becomes uneven due to the influence of the fixing device 14 , and the temperature of the shielding plate 35 on the side of the transfer belt cleaning device 15 increases. uneven distribution. However, when the image forming apparatus is operated to near the predetermined temperature at which the toner in the toner storage and conveyance path melts, the temperature distribution inside the shielding plate 35 becomes uniform, and the temperature distribution of the shielding plate 35 on the transfer belt cleaning device 15 side becomes uniform. has a nearly uniform temperature distribution.

Therefore, as shown in FIGS. 11 and 12, the temperature sensor 30a is arranged on the shielding plate 35 arranged between the fixing device 14 and the transfer belt cleaning device 15. FIG. In this example, the temperature sensor 30a is arranged on the transfer belt cleaning device 15 side, which is the cleaning means side of the shielding plate 35 . Thereby, the temperature can be stably detected by the temperature sensor 30a.

For example, when the temperature sensor 30a is arranged inside the toner containing and conveying path of the transfer belt cleaning device 15, it needs to be arranged at the highest temperature part in the toner containing and conveying path. However, the temperature distribution inside the toner containing and conveying path changes due to the amount of toner in the toner containing and conveying path, the toner distribution, and the temperature rise due to the sliding resistance of the rotating shaft 25 and the toner conveying screw 23 . Therefore, it is difficult to specify the hottest part in the toner containing and conveying path.

Further, when the temperature sensor 30a is attached to the transfer belt cleaning device 15, the transfer belt cleaning device 15 is integrated as the transfer belt unit 17 when the toner storage container 27 is full of toner as described above. be exchanged. Therefore, the temperature sensor 30a also needs to be replaced together with the transfer belt unit 17, which increases the cost of the transfer belt unit 17. FIG. Furthermore, since the temperature sensor 30a is connected to an electric board (not shown) provided on the main body of the image forming apparatus, it is troublesome to disconnect the electric board when the transfer belt unit 17 is replaced.

Further, even when the temperature sensor 30a is detachably attached to the transfer belt cleaning device 15, it takes time to detach the temperature sensor 30a from the transfer belt cleaning device 15 when the transfer belt unit 17 is replaced.

Therefore, it is desirable to install the temperature sensor 30a at a position that does not require attachment and detachment when the transfer belt unit 17 is replaced on the main body side.

In this example, as described above, the temperature sensor 30a is positioned between the fixing device 14 and the transfer belt cleaning device 15 by the shielding plate 35 fixed to the right side plate 60 and the left side plate 61, which are the body frame of the image forming apparatus. is provided in

Next, detailed arrangement of the temperature sensor 30a will be described. The location of the temperature sensor 30a in the direction of arrow Z, the location of location in the direction of arrow X, and the location of location in the direction of arrow Y will be described in order.

First, the location of the temperature sensor 30a in the direction of the arrow Z will be described.

In order to measure the temperature closer to the temperature of the toner storage path, which is the space inside the transfer belt cleaning device 15, the temperature sensor 30a needs to be arranged at a position where it is less susceptible to the heat of the fixing device 14. is.

Therefore, as shown in FIG. 11, the temperature sensor 30a is arranged on the transfer belt cleaning device 15 side, which is the cleaning means side of the shielding plate 35, in the arrow Z direction. Specifically, the temperature sensor substrate 30 on which the temperature sensor 30a is mounted is attached to the temperature sensor holder 32, and the temperature sensor holder 32 is attached to the shielding plate 35 on the transfer belt cleaning device 15 side. As a result, the temperature sensor 30a is arranged on the transfer belt cleaning device 15 side of the shielding plate 35 .

Next, the arrangement location of the temperature sensor 30a in the direction of the arrow X will be described.

As described above, in the initial operation state of the image forming apparatus, the temperature distribution inside the shielding plate 35 becomes uneven due to the influence of the fixing device 14, and the temperature distribution of the shielding plate 35 on the side of the transfer belt cleaning device 15 becomes uneven. become uniform. However, when the operation is performed to the vicinity of the predetermined temperature at which the toner in the toner storage and conveyance path melts, the temperature distribution inside the shielding plate 35 is uniformed, and the temperature distribution of the shielding plate 35 on the side of the transfer belt cleaning device 15 is almost the same. A uniform temperature distribution is obtained.

At this time, when the sheet passes through the facing portion (secondary transfer portion) where the intermediate transfer belt 5 and the secondary transfer roller 12 face each other, the temperature in the vicinity of the secondary transfer portion affects (the temperature of) the passed sheet. and the temperature drops momentarily. On the other hand, since the toner containing and conveying path, which is a space inside the transfer belt cleaning device 15, is surrounded by the cleaning frame unit 26 made of a resin member, it is hardly affected by the passed sheets. For example, as shown in FIG. 12, in the shielding plate 35 arranged between the fixing device 14 and the transfer belt cleaning device 15, the area near the facing portion where the intermediate transfer belt 5 and the secondary transfer roller 12 face each other is An area A is defined, and an area farther from the facing portion than the area A is defined as an area B. In this case, the area A in FIG. 12 is affected by the temperature of the sheet when one cold sheet passes through the secondary transfer portion, and the temperature drops. Since it is inside the frame unit 26, the temperature does not drop. On the other hand, since area B in FIG. 12 is farther from the secondary transfer portion than area A, it is not affected by the temperature of the sheet passing through the secondary transfer portion, and the temperature does not decrease.

Therefore, the temperature sensor 30a is located away from the secondary transfer portion (area B in FIG. 12), which is not affected by the temperature of the sheet passing through the secondary transfer portion, and has a higher ambient temperature than the toner storage/conveyance path. place in position. That is, the temperature sensor 30a is detected by the transfer belt cleaning device from the position where the secondary transfer roller 12 faces the intermediate transfer belt 5 in the direction of the arrow X perpendicular to the axial direction (the direction of the arrow Y) that is the center of rotation of the drive roller 6. 15 is arranged at a position away from the position facing the intermediate transfer belt 5 . At the position of this example, the temperature sensor 30a is less susceptible to disturbances due to the temperature distribution of the fixing device 14 and the passage of paper, etc., and can measure an ambient temperature higher than the highest temperature of the toner storage/conveyance path. Moreover, the temperature detected by the temperature sensor 30a is correlated with the highest temperature of the toner containing and conveying path.

Also, at this time, the temperature sensor substrate 30 is arranged so as not to cover the transfer belt cleaning device 15 in the direction of the arrow X. As shown in FIG. As a result, as shown in FIG. 13, part of the temperature sensor substrate 30 and temperature sensor holder 32 and part of the transfer belt cleaning device 15 can be overlapped in the direction of arrow Z, and the height of the main body can be suppressed.

Finally, the arrangement location of the temperature sensor 30a in the arrow Y direction will be described.

As described above, in the initial operation state of the image forming apparatus, the temperature distribution inside the shielding plate 35 becomes uneven due to the influence of the fixing device 14, and the temperature distribution of the shielding plate 35 on the side of the transfer belt cleaning device 15 becomes uneven. become uniform. However, when the operation is performed to the vicinity of the predetermined temperature at which the toner in the toner storage and conveyance path melts, the temperature distribution inside the shielding plate 35 is uniformed, and the temperature distribution of the shielding plate 35 on the side of the transfer belt cleaning device 15 is almost the same. A uniform temperature distribution is obtained.

Therefore, the temperature sensor substrate 30 on which the temperature sensor 30a is mounted may be arranged at any position in the direction of the arrow Y where the ambient temperature is higher than that of the toner storage/conveyance path. In this example, bundled wires coming out of the temperature sensor board 30 are connected to the left electric board (not shown). Therefore, in order to shorten the bundle length, the temperature sensor board 30 on which the temperature sensor 30a is mounted is arranged on the side where the electric board (not shown) provided in the image forming apparatus is arranged. At the position of this example, the temperature sensor 30a is less susceptible to disturbances due to the temperature distribution of the fixing device 14 and the passage of paper, and can measure an ambient temperature higher than the highest temperature of the toner storage and conveyance path. Moreover, the temperature detected by the temperature sensor 30a is correlated with the highest temperature of the residual toner storage and conveyance path.

As described above, the temperature sensor 30a is arranged on the transfer belt cleaning device 15 side of the shielding plate 35, in the vicinity of the toner containing and conveying path away from the secondary transfer portion, and in an atmosphere temperature higher than that of the toner containing and conveying path. Thereby, the temperature can be detected stably and reliably. Further, it is possible to control the operation of the image forming apparatus so that the temperature of the toner containing and conveying path does not exceed a predetermined temperature. Therefore, it is possible to suppress the occurrence of image defects and conveyance defects due to toner fusion in the toner storage and transportation path without providing an air passage or the like for suppressing temperature rise inside the toner storage and transportation path. That is, according to this embodiment, it is possible to reliably transport the removed toner after transfer without increasing the size of the apparatus.

It should be noted that the configuration of the embodiment described above is an example, and the present invention is not limited to this. The effect of the present invention is exhibited by arranging the temperature sensor 30a in an ambient temperature that is stable and higher than that of the toner storage conveying path in the shielding plate 35 arranged between the fixing device 14 and the transfer belt cleaning device 15. It is.

Further, in the above-described embodiments, a printer is used as an example of the image forming apparatus, but the present invention is not limited to this. For example, other image forming apparatuses such as copiers, facsimile machines, etc., or other image forming apparatuses such as multifunction machines combining these functions may be used. In addition, an image forming apparatus that uses an intermediate transfer member as an image carrier, sequentially superimposes and transfers toner images of respective colors onto the intermediate transfer member, and collectively transfers the toner images carried on the intermediate transfer member onto a sheet. was exemplified, but it is not limited to this. For example, a photosensitive drum on which a plurality of developing means face each other is used as an image carrier, toner images of respective colors are sequentially formed on the photosensitive drum, and the toner images formed on the photosensitive drum are collectively transferred onto a sheet. It may be an image forming apparatus. Similar effects can be obtained by applying the present invention to these image forming apparatuses.

5 ... intermediate transfer belt 6 ... drive roller 7 ... tension roller 8 ... driven roller 10 ... image forming device 12 ... secondary transfer roller 14 ... fixing device 15 ... transfer belt cleaning device 17 ... transfer belt unit 20 ... cleaning blade 26 ... cleaning Frame unit 26m Toner container 26n Toner conveying unit 27 Toner container 30 Temperature sensor substrate 30a Temperature sensor 32 Temperature sensor holder 35 Shield plate 40 Right support plate 41 Left support plate 60 Right plate 61 … left plate

Claims (9)

an image carrier;
a transfer unit provided opposite to the image carrier for transferring the toner image formed on the image carrier onto a sheet;
cleaning means for removing toner remaining on the image carrier after the toner image formed on the image carrier is transferred onto a sheet;
a storage unit that stores toner removed from the image carrier by the cleaning unit;
a fixing means for fixing the toner image transferred to the sheet onto the sheet;
and wherein the cleaning means is provided between the image carrier and the fixing means,
The cleaning means includes a cleaning member that removes toner from the image carrier, a toner conveying member that conveys the toner removed by the cleaning member to the container, and a frame that supports the cleaning member and the toner conveying member. including the body and
1. An image forming apparatus according to claim 1, wherein a shielding member is provided between said frame and said fixing means, and a temperature sensor for detecting temperature is provided on said shielding member on a side of said cleaning means. The temperature sensor moves from the position where the transfer means faces the image carrier to the position where the cleaning means faces the image carrier in a direction orthogonal to the axial direction that is the center of rotation of the image carrier. 2. The image forming apparatus according to claim 1, wherein the image forming apparatus is arranged at a separated position. The temperature sensor is arranged on a side of an electric board provided in the image forming apparatus, which is connected to the temperature sensor, in an axial direction of the rotation center of the image carrier. Item 3. The image forming apparatus according to Item 1 or 2. The shielding member is arranged so as to cover the cleaning means in an axial direction serving as a center of rotation of the image carrier and in a direction orthogonal to the axial direction when viewed in a vertical direction. The image forming apparatus according to any one of claims 1 to 3. 5. The image forming apparatus according to claim 1, wherein the shielding member is made of metal. The shielding member provided with the temperature sensor is fixed to a body frame of the image forming apparatus,
6. The image forming apparatus according to claim 1, wherein said cleaning means is provided detachably with respect to the image forming apparatus. 7. An image forming apparatus according to claim 6, wherein said cleaning means is provided integrally with said image carrier and said accommodating portion as a detachable unit with respect to the image forming apparatus. The image bearing member is an endless belt that is stretched and rotated by a plurality of stretching members,
The transfer means is provided facing one of the plurality of stretching members via the belt,
The cleaning unit is provided to face the one stretching member facing the transfer unit via the belt, and is provided downstream of a portion facing the transfer unit in the rotation direction of the belt. 8. The image forming apparatus according to any one of claims 1 to 7, characterized in that: 9. The image forming apparatus according to claim 1, wherein the operation of the image forming apparatus is controlled so that the temperature detected by the temperature sensor does not exceed a predetermined temperature. image forming device.

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