JP2008064904A - Rotating body for electrophotographic system image forming apparatus, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotating body for an electrophotographic system image forming apparatus which can be cooled without using a cooling means requiring a large installation space and can suppress the temperature rising of an image forming section in an image forming apparatus without interfering the image forming apparatus from being compact and being small in occupancy space; and to provide an image forming apparatus which can suppress the temperature rising of the image forming section by having the rotating body. <P>SOLUTION: The rotating body (14) is a rotating body (for instance, a developing roller 14) for the image forming section (Y, M, C or K) and has a sleeve (SL) made of metal as a base material and a shaft (SF2) arranged in the sleeve. In addition, the rotating body (14) has a space section between the inwall surface of the sleeve and the shaft, and a cooling material (140) is enclosed in the space section. The image forming apparatus A has the rotating body. It is possible that the thermal conductivity of the shaft (SF2) is made higher than that of a metal base material constituting the sleeve (SL). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electrophotographic image forming apparatus such as a copying machine, a printer, a facsimile machine, or a combination machine combining two or more of these, and more particularly to a rotating member such as a developing roller and a photosensitive member.

  In an electrophotographic image forming apparatus, the surface of a photoreceptor is usually charged by a charging device, and an electrostatic latent image corresponding to an image to be formed by an image exposure device is formed in the charging area. The image is developed by a developing device to form a toner image, the toner image is finally transferred onto a recording medium, and the transferred toner image is fixed on the recording medium with heat and pressure by a fixing device.

Such image forming apparatuses can be roughly classified into a monochrome image forming apparatus and a color image forming apparatus (typically, a full color image forming apparatus) capable of forming an image using two or more colors of toner.
In a monochrome image forming apparatus, a toner image formed on a photoconductor is directly transferred onto a recording medium using a transfer device, or is primary-transferred to an intermediate transfer member by a primary transfer device. The image is transferred from the body onto a recording medium by a secondary transfer device and fixed by a fixing device. In some cases, the toner image formed on the photoconductor is transferred to a recording medium held on a transfer body and then fixed on the recording medium.

Known color image forming apparatuses include so-called four-cycle color image forming apparatuses and tandem color image forming apparatuses.
The four-cycle type color image forming apparatus charges the surface of a photoreceptor, exposes the charged area to form an electrostatic latent image, and develops the electrostatic latent image with a developing device to form a toner image. . In such toner image formation, a plurality of developing devices containing different color toners are sequentially used to sequentially form different color toner images on the photoreceptor. Further, the toner images formed on the photoconductor are sequentially superposed on the intermediate transfer body by using a primary transfer device, and are primarily transferred onto the intermediate transfer body, and the multiple toner images on the intermediate transfer body thus formed are subjected to secondary transfer. A color image can be obtained by secondary transfer to a recording medium with the apparatus and fixing with a fixing apparatus. It is also possible to form an image using only one developing device or a plurality of developing devices less than the total number of developing devices.

  In a tandem type color image forming apparatus, an image forming unit including a photosensitive member, a charging device for charging the surface of the photosensitive member, an image exposing device, a developing device for developing an electrostatic latent image on the photosensitive member, and the like is provided according to the color of the toner. A plurality of toner images are sequentially arranged along the intermediate transfer body, and a toner image formed on the image carrier in each image forming unit is primarily transferred onto the intermediate transfer body by the primary transfer device, and the intermediate transfer is performed. The multiple toner image on the body is secondarily transferred to the recording medium by the secondary transfer device and fixed by the fixing device. It is also possible to form an image using only one image forming unit or a plurality of image forming units smaller than the total number of image forming units.

  In any of the above color image forming apparatuses, the toner image formed on the photosensitive member may be transferred to a recording medium held on a transfer member and then fixed on the recording medium.

  By the way, whether it is a monochrome image forming apparatus or a color image forming apparatus, the image forming apparatus is provided with a fixing device for fixing a toner image to a recording medium under heating as described above. Is provided.

These fixing device, power supply base, and the like are heat generating portions. When image formation is continuously performed, the temperature inside the device rises due to heat generated from the heat generating portion, and if left untreated, the inside of the device becomes in a high temperature and low humidity state. It will become various troubles.
For example, a toner used for developing an electrostatic latent image has a high chargeability at high temperatures and low humidity, resulting in a decrease in developability, which may cause development failure.
When the photosensitive member becomes high temperature, the developing roller facing it and the developer held on the photosensitive member rise in temperature, and the same problem may occur.
In addition, when the temperature of the photoconductor increases, the charging characteristics thereof decrease, and the surface potential on the photoconductor may decrease, resulting in image defects. If the temperature rise causes local temperature unevenness on the photoconductor, There is a risk of uneven density in the image.

For this reason, it is necessary to suppress the temperature rise in the image forming apparatus, in particular, the temperature rise in the image forming unit including the photosensitive member and the developing device for forming the electrostatic latent image and developing the electrostatic latent image.
In this regard, it is known to suppress the temperature rise in the apparatus using a cooling fan.
Japanese Patent Application Laid-Open No. 2004-109868 describes that a developer regulating member in a developing device is formed in a hollow shape, and a cooling medium is brought into contact with the hollow portion, blown, or a cooling liquid is passed. ing.

Japanese Patent Application Laid-Open No. 2002-365888 describes that a part of a developer container of a developing device is composed of a heat conductive member, and the member is extended and cooled from its end.
Japanese Patent Application Laid-Open No. 10-26923 describes providing a cooling means for circulating a coolant as a method for cooling the exposure means.

Japanese Patent Application Laid-Open No. 10-282770 describes that a cooling means for circulating a cooling liquid is provided as a method for cooling an exposure optical system disposed inside a photoconductor.
Japanese Patent Application Laid-Open No. 9-44062 describes disposing a coolant reflux pipe in an image forming apparatus.

JP 2004-109868 A JP 2002-365888 A JP-A-10-26923 Japanese Patent Laid-Open No. 10-282770 Japanese Patent Laid-Open No. 9-44062

  On the other hand, along with the recent increase in demand for downsizing and space saving of image forming apparatuses, each part in the image forming apparatus tends to be arranged close to each other. For example, heat generation such as the fixing device and the power supply base There is a tendency that the image forming unit is close to the image forming unit including the developing device and the photosensitive member. As a result, the temperature of the image forming unit is more likely to increase.

  As described above, in the state where the respective parts are arranged close to each other for compactness and space saving, the flow of airflow is deteriorated in the fan, and the cooling effect cannot be sufficiently exhibited. In addition, use of a fan may increase toner scattering in the apparatus.

  Further, in the cooling means such as the developing device described in the above-mentioned publication, it is described in JP-A-2004-109868, JP-A-10-26923, JP-A-10-282770, and JP-A-9-44062. As described above, it is required to install a means for circulating or sending a cooling medium or the like to a predetermined portion, and a part of the developer container is made of a heat conductive member as described in JP-A-2002-365888. When it is configured and the member is extended and cooled from its end, an extension of the member and a cooling means for the extended member end are required. It cannot meet the demand for space saving.

  Therefore, the present invention can be cooled without using a cooling means that requires a large installation space for circulating the refrigerant, and the like, thereby preventing downsizing and space saving of the image forming apparatus. A first object of the present invention is to provide a rotating body for an electrophotographic image forming apparatus that can suppress an increase in temperature of an image forming unit including a photosensitive member and a developing device that form an electrostatic latent image and develop the electrostatic latent image. And

  The present invention also provides a photosensitive member that forms an electrostatic latent image in an image forming apparatus and develops the electrostatic latent image without using a cooling unit that requires a large installation space for circulating the refrigerant, and the like. A second object is to provide an electrophotographic image forming apparatus capable of suppressing a temperature rise in an image forming unit including the apparatus.

  In order to solve the first problem, the present invention is used in an image forming section including a photoconductor and a developing device for forming an electrostatic latent image in an electrophotographic image forming apparatus and developing the electrostatic latent image. A rotating body having a metal-based sleeve and a shaft for rotating the sleeve disposed in the sleeve, and having a space between the inner wall surface of the sleeve and the shaft, An electrophotographic image forming apparatus rotating body in which a cooling material is sealed in a space is provided.

  In order to solve the second problem, the present invention provides an electrophotographic image forming apparatus provided with such a rotating body.

  According to the rotating body according to the present invention, even if the rotating body is heated by heat generated from a heat generating part such as a fixing device or a power supply base, the inner surface of the sleeve of the rotating body and the sleeve are arranged in the sleeve. Further, a cooling material is sealed in a space between the shaft for rotating the sleeve, and the temperature rise of the rotating body is suppressed by the cooling effect of the cooling material, and as a result, an image including the photosensitive member and the developing device. The temperature rise of the forming part is suppressed, and a good image can be formed accordingly.

In the rotating body according to the present invention, the “shaft for rotating the sleeve disposed in the sleeve” may be a shaft that is driven to rotate by a motor or the like and that rotates with the sleeve. It may be a support shaft that supports the sleeve so that the sleeve does not rotate itself but the sleeve can rotate around it.
In any case, the heat conductivity of the shaft of the metal substrate constituting the sleeve is adjusted so that heat can be transferred from the sleeve to the shaft side via the cooling material and the heat can be released from the shaft. It may be larger than the thermal conductivity.

  The “rotary body for an electrophotographic image forming apparatus” according to the present invention is not particularly limited, but a specific example is a developing roller in which the sleeve is used as a developing sleeve. When the rotating body is a developing roller, the following can be said to be the subject of the present invention. In other words, the cooling can be performed without using a cooling unit that requires a large installation space for circulating the refrigerant, and the electrostatic latent image in the image forming apparatus is thereby prevented without hindering compactness and space saving of the image forming apparatus. It is possible to suppress the temperature rise of the image forming unit including the photosensitive member and the developing device that forms the image and develops the electrostatic latent image, and it is possible to ensure the suppression of the excessive temperature rise of the developer, so that the development of the electrostatic latent image is excellent. It is to provide a developing roller that can be used for the following.

Another specific example of the rotating body is a photoconductor in which the sleeve is formed as a photoconductor sleeve.
When the rotating body is a photoconductor, the following can be said to be the subject of the present invention. In other words, the cooling can be performed without using a cooling unit that requires a large installation space for circulating the refrigerant, and the electrostatic latent image in the image forming apparatus is thereby prevented without hindering compactness and space saving of the image forming apparatus. The temperature rise of the image forming unit including the photosensitive member and the developing device that forms an image and develops the electrostatic latent image can be suppressed, and the temperature rise of the developer and the like can also be suppressed by suppressing the temperature increase of itself. It is an object of the present invention to provide a photoreceptor that can suppress a decrease in charging characteristics of the photoreceptor that may occur when heated, and that can form a good image.

Examples of the cooling material include a hydrogel base material using a polymer material selected from natural water-soluble polymer materials and synthetic polymer materials.
Examples of the natural water-soluble polymer material include at least one natural water-soluble polymer material selected from tragacanth gum, karaya gum, gum arabic, sodium alginate, mannan, gelatin and pectin.
Examples of the synthetic polymer material include synthetic polymer materials prepared from polyvinyl alcohol (PVA), polyacrylic acid, a salt of polyacrylic acid, carboxyvinyl polymer (CVP), and the like.
The cooling material may be an antifreeze coolant (eg, ethylene glycol).

The rotating body according to the present invention may be a monochrome image forming apparatus or a color image forming apparatus such as the aforementioned 4-cycle type or tandem type.
Further, the image forming apparatus according to the present invention may be an image forming apparatus dedicated to monochrome, or may be a color image forming apparatus such as the aforementioned 4-cycle type or tandem type.

  As described above, according to the present invention, the image forming apparatus can be cooled without using a cooling unit that requires a large installation space for circulating the refrigerant, thereby preventing the compactness and space saving of the image forming apparatus. Provided is a photoreceptor for forming an electrostatic latent image in an image forming apparatus and developing the electrostatic latent image, and a rotating body for an electrophotographic image forming apparatus capable of suppressing a temperature rise in an image forming unit including the developing device. Can do.

  Further, according to the present invention, there is provided a photosensitive member that forms an electrostatic latent image in an image forming apparatus and develops the electrostatic latent image without using a cooling unit that requires a large installation space for circulating a refrigerant, etc. It is possible to provide an electrophotographic image forming apparatus capable of suppressing a temperature rise in an image forming unit including a developing device.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows an example of an image forming apparatus provided with a rotating body according to the present invention. An image forming apparatus A in FIG. 1 is a tandem color image forming apparatus.
The image forming apparatus A shown in FIG. 1 has an endless intermediate transfer belt 3 wound around a driving roller 21 and a roller 22 facing the driving roller 21. The transfer belt 3 can be rotated counterclockwise in the figure (arrow direction in the figure) by a driving roller 21 driven by a belt driving unit (not shown).

  A cleaning device 4 that cleans secondary transfer residual toner and the like on the transfer belt 3 faces the belt portion on the opposing roller 22, and a waste toner box 41 is connected to the cleaning device 4. The secondary transfer roller 5 faces the belt portion on the driving roller 21.

  The surface layer portion of the secondary transfer roller 5 is formed of an elastic material, and is pressed against the intermediate transfer belt 3 by a pressing unit (not shown) to form a nip portion between the intermediate transfer belt 3 and the intermediate transfer belt 3. , Or following the movement of the recording medium (recording paper S in this case) fed into the nip as will be described later. A secondary transfer bias can be applied to the secondary transfer roller 5 from a secondary transfer bias power supply device (not shown).

  A timing roller pair 7 is disposed below the secondary transfer roller 5, and a cassette 8 containing the recording paper S is disposed below the pair of timing rollers 7. The recording paper S in the cassette 8 is supplied to the timing roller pair 7 by a paper feed roller 81 at a predetermined timing. A fixing device 6 is disposed above the transfer roller 5, and a pair of paper discharge rollers 9 and a paper discharge tray T are provided further downstream thereof.

  Between the rollers 21 and 22 around which the intermediate transfer belt 3 is wound, the yellow image forming unit Y, the magenta image forming unit M, the cyan image forming unit C, and the rollers 22 to 21 along the transfer belt 3. Black image forming portions K are arranged in this order.

  Each of the image forming units Y, M, C, and K includes a drum-type photoconductor 11, and around the photoconductor, a charging device 12, an image exposure device 13, a developing device 14, a primary transfer roller 2, A cleaning device 15 and the like for removing and cleaning the primary transfer residual toner on the photosensitive member are arranged in this order.

  The primary transfer roller 2 faces the photoconductor 11 with the transfer belt 3 in between, and rotates as the belt travels. A primary transfer bias for primary transfer of a toner image formed on the photoreceptor 11 to the belt 3 can be applied to the primary transfer roller 2 from a primary transfer bias power supply device (not shown).

  The exposure device 13 can perform image exposure on the photoconductor 11 using a laser beam in accordance with image information provided from a personal computer (not shown) or the like.

The photoconductor 11 in each image forming unit can be driven to rotate clockwise in the drawing by a photoconductor drive motor (not shown). The photoreceptor 11 will be further described later.
A charging voltage can be applied to the charging device 12 in each image forming unit at a predetermined timing from a charging power supply device (not shown).

The developing device 14 in each image forming unit can develop the electrostatic latent image formed on the photoconductor 11 with a developing roller 141 to which a developing bias voltage is applied from a developing bias applying power supply device (not shown). The developing device 14 uses a so-called two-component developer mainly composed of toner and a magnetic carrier. Each developing device 14 can be replenished with toner from a toner cartridge TC disposed above the belt 3 so as to correspond to each developing device. The developing roller 141 will be further described later.
The developing device may employ a so-called one-component developer mainly composed of toner.

According to the image forming apparatus of FIG. 1, an image can be formed using one or more of the image forming units.
Taking a case where a full color image is formed using all of the image forming portions, for example, first, a yellow toner image is formed in the yellow image forming portion Y, and this is primarily transferred to the transfer belt 3.

  That is, in the yellow image forming unit Y, the photosensitive member 11 is rotationally driven in the clockwise direction in the drawing, and the image exposure device is applied to the charged area of the photosensitive member 11 whose surface is uniformly charged to a predetermined potential by the charging device 12. 13, yellow image exposure is performed, and a yellow electrostatic latent image is formed on the photoreceptor 11. This electrostatic latent image is developed by a developing roller 141 to which a developing bias of a developing device 14 having yellow toner is applied to become a visible yellow toner image, and the toner image is transferred onto the transfer belt 4 by the primary transfer roller 2. Primary transfer is performed. At this time, a primary transfer bias voltage is applied to the primary transfer roller 2 from a power supply device (not shown).

  Similarly, a magenta toner image is formed in the magenta image forming unit M and transferred to the transfer belt 3, a cyan toner image is formed in the cyan image forming unit C and transferred to the transfer belt 3, and in the black image forming unit K. A black toner image is formed and transferred to the transfer belt 3.

  Yellow, magenta, cyan, and black toner images are formed at a timing at which these toner images are transferred onto the intermediate transfer belt 3 in an overlapping manner. The multiple toner images formed on the transfer belt 3 move toward the secondary transfer roller 5 as the transfer belt 3 rotates.

  On the other hand, the recording paper S is pulled out from the cassette 8 by the paper feed roller 81 and supplied to the timing roller pair 9 and is on standby.

  The recording sheet S waiting at the timing roller pair 9 is supplied to the nip portion between the transfer belt 3 and the secondary transfer roller 5 in accordance with the multiple toner image sent by the intermediate transfer belt 3, and is not shown. The multiple toner images are secondarily transferred onto the recording paper S by the secondary transfer roller 5 to which a secondary transfer bias is applied from the power supply device.

  Thereafter, the recording medium paper S is passed through the fixing device 6 where the multiple toner images are fixed on the recording paper S under heat and pressure. The recording sheet S continues and is discharged to the discharge tray T by the discharge roller pair 9.

  The transfer residual toner and the like on the photosensitive member of each image forming unit are removed and cleaned by the cleaning device 15 and the transfer residual toner and the like on the intermediate transfer belt 3 are removed and cleaned by the cleaning device 4, respectively.

Next, the developing roller 14 and the photoreceptor 11 will be further described.
2A is a cross-sectional view of the developing roller 141 of each developing device 14, and FIG. 2B is a cross-sectional view taken along line XX in FIG. 2A.
As shown in the figure, the developing roller 141 has a cylindrical developing sleeve SL. One end of the sleeve SL is fitted to the flange portion F1, and the other end is fitted to the other flange portion F2. These flange parts are supported.

A drive shaft SF1 is integrally formed with the flange portion F1.
A support shaft SF2 is inserted through the flange portion F2 into the sleeve SL, and its insertion tip is rotatably supported by the bearing portion B1 on the inner surface side of the flange portion F1. Further, the support shaft SF2 is also rotatably supported by the bearing portion B2 in the flange portion F2.

  A magnet piece Mg is fixed to a portion in the sleeve SL of the support shaft SF2. Further, there is a space between the support shaft SF2 and the sleeve SL, and the cooling material 140 is sealed there.

The sleeve SL is made of a nonmagnetic metal material (aluminum in this example), and the support shaft SF2 is a gold having a thermal conductivity k higher than the thermal conductivity (236 W · m ⁻¹ · ° C. ⁻¹ ) of aluminum as the sleeve base material ( k = 319 W · m ⁻¹ · ° C. ⁻¹ ), silver (k = 428 W · m ⁻¹ · ° C. ⁻¹ ), copper (k = 403 W · m ⁻¹ · ° C. ⁻¹ ), etc. Etc.).

  The cooling material 140 may be a cooling agent generally used for medical use, versatile computer use, and the like, and is at least one natural water selected from tragacanth gum, karaya gum, gum arabic, sodium alginate, mannan, gelatin, pectin and the like. Water-containing gel base material using a synthetic polymer material prepared from a water-containing gel base material using a conductive polymer material or polyvinyl alcohol (PVA), polyacrylic acid or a salt thereof, carboxyvinyl polymer (CVP), etc. .

  In the developing roller 141, the support shaft SF2 is fixedly supported by a member (not shown), and the drive shaft SF1 is rotationally driven by a developing motor (not shown), so that the sleeve SL surrounds the support shaft SF2 and the magnet Mg provided thereon. , The magnetic carrier (and the toner adhering to it) is held on the sleeve SL by the magnetic force of the magnet piece Mg, and the toner is conveyed to the developing area facing the photoconductor 11, and the electrostatic latent image on the photoconductor 11 is transferred. It can be used for development.

For example, the coolant 140 is affixed to the inner wall surface of the developing sleeve SL to absorb the heat of the sleeve SL and the developer thereon, and can cool the developer by the action of the vaporization heat of the coolant. The cooling material is not particularly limited as long as it is not in a solid state.
Other cooling materials, for example, an antifreeze and rust preventive coolant such as ethylene glycol generally used in automobiles may be employed.

  As described above, the non-magnetic sleeve SL of the developing roller 141 is made of aluminum, which generally has high thermal conductivity among metals, and therefore the inner wall surface of the sleeve SL can be cooled to a uniform temperature. Thereby, the temperature rise of the developer on the sleeve can be suppressed. Even if the cooling material is sealed in the developing roller in this way, the temperature rise in the apparatus due to continuous operation of the image forming apparatus, in particular, the temperature rise in the image forming unit including the photoreceptor 11 and the developing apparatus 14 is temporarily. Can be suppressed.

  In the developing roller 14, as described above, the support shaft SF <b> 2 is formed of a metal material having a higher thermal conductivity than aluminum that is the base material of the sleeve SL, so that the heat of the developer is transferred from the inner wall surface of the sleeve to the cooling material 140. The heat can be absorbed and further moved to the support shaft SF2 and released from the shaft to the outside, and this can also suppress the temperature rise of the developing roller and the developer held thereon.

  Further, as can be seen from FIG. 2B, the contact area between the cooling material 140 and the support shaft SF2 is increased at the part where the magnet piece Mg is partially vacant, thereby further enhancing the cooling effect. It has been.

  When the image forming apparatus A is provided with a cooling fan, the developing roller 141 may be disposed close to the airflow generated by the fan, and the developing roller is further effectively cooled.

3A is a cross-sectional view of the photoconductor 11, and FIG. 3B is a cross-sectional view taken along line YY of FIG. 3A.
The photoreceptor 11 has a photoreceptor sleeve DR in which a photosensitive element is provided on a cylindrical base tube made of a nonmagnetic metal material. One end of the sleeve DR is fitted into the flange part f1, and the other end is already provided. It is fitted to one flange part f2 and supported by these flange parts.

  A drive shaft sf that passes through the flange portions f1 and f2 passes through the photoreceptor sleeve DR. The drive shaft sf is formed of a metal material whose thermal conductivity is higher than that of the base material of the sleeve DR.

There is a space between the drive shaft sf and the inner wall surface of the sleeve DR, and the cooling material 110 is sealed in the space.
The same cooling material as that used for the developing roller 14 is used.
According to this photoreceptor 11, the photoreceptor sleeve DR can be rotated by rotationally driving the drive shaft sf with a photoreceptor drive motor (not shown).

  With this structure, the photoconductor 11 is cooled in the same manner as the developing roller 141, and the temperature inside the apparatus increases due to continuous operation of the image forming apparatus, in particular, the photoconductor 11 itself and the image forming unit including the photoconductor 11 and the developing device 14. Temperature rise can be suppressed.

  Although the tandem color image forming apparatus has been described above as an example, the present invention can be applied to a four-cycle color image forming apparatus and a monochrome image forming apparatus.

  INDUSTRIAL APPLICABILITY The present invention can be used to provide an electrophotographic image forming apparatus such as a copying machine, a printer, a facsimile machine, or a multifunction machine combining two or more of these.

1 is a diagram illustrating a schematic configuration of an example of an image forming apparatus according to the present invention. 2A is a cross-sectional view of the developing roller of the developing device of the image forming unit in the image forming apparatus of FIG. 1, and FIG. 2B is a cross-sectional view taken along line XX of FIG. . 3A is a cross-sectional view of the photoconductor of the image forming unit in the image forming apparatus of FIG. 1, and FIG. 3B is a cross-sectional view taken along line YY of FIG. 3A.

Explanation of symbols

A Image forming apparatus Y Yellow image forming part M Magenta image forming part C Cyan image forming part K Black image forming part 11 Photoreceptor DR Photoreceptor sleeve f1, f2 Flange part sf Drive shaft 110 Cooling material 12 Charging apparatus 13 Image exposure apparatus 14 Developing device 141 Developing roller SL Developing sleeve F1, F2 Flange portion SF1 Drive shaft SF2 Support shaft B1, B2 Bearing portion Mg Magnet piece 140 Cooling material 15 Cleaning device 2 Primary transfer roller 21 Drive roller 22 Opposing roller 3 Intermediate transfer belt 4 Cleaning Device 5 Secondary transfer roller 6 Fixing device 7 Timing roller pair 8 Paper feed cassette 81 Paper feed roller 9 Paper discharge roller pair T Paper discharge tray S Recording paper

Claims (7)

A rotating member used in an image forming unit including a photosensitive member and a developing device for forming an electrostatic latent image in an electrophotographic image forming apparatus and developing the electrostatic latent image; The sleeve has a shaft for rotating the sleeve, and has a space portion between the inner wall surface of the sleeve and the shaft, and a cooling material is sealed in the space portion. A rotating body for an electrophotographic image forming apparatus. 2. The rotating body for an electrophotographic image forming apparatus according to claim 1, wherein the thermal conductivity of the shaft is larger than the thermal conductivity of the metal substrate constituting the sleeve. 3. The rotating body for an electrophotographic image forming apparatus according to claim 1, wherein the sleeve is a developing roller used as a developing sleeve. 3. The rotating body for an electrophotographic image forming apparatus according to claim 1, wherein the sleeve is a photosensitive body formed as a photosensitive sleeve. 5. The rotation for an electrophotographic image forming apparatus according to claim 1, wherein the cooling material is a hydrogel base material using a polymer material selected from a natural water-soluble polymer material and a synthetic polymer material. body. 5. The rotating body for an electrophotographic image forming apparatus according to claim 1, wherein the cooling material is an antifreeze coolant. An electrophotographic image forming apparatus comprising the rotating body according to claim 1.