JP2001296755A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device where the rising of temperature in an intermediate transfer body can be controlled with a simple constitution, minimum energy and without enlargement of the image forming device due to restrictions such as relationship in positions or distance of a heat fixing means and the intermediate transfer body or complication of the device due to installment of a heat shielding means. SOLUTION: In the image forming device, a temperature detecting means is arranged in contact with the intermediate transfer body or in its proximity and at least one air ejecting means is provided in the proximity of the intermediate transfer body and the air ejecting means is operated according to the detected temperature of the temperature detecting means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copying machine, a printer, a facsimile, etc., in which a charging means, an image writing means, a developing means and the like are arranged around an image carrier to form a toner image on the image carrier. The present invention relates to an electrophotographic image forming apparatus for forming an image, retransferring the toner image onto an intermediate transfer member, and transferring and fixing the toner image on the intermediate transfer member onto a recording material to form an image.

[0002]

2. Description of the Related Art Conventionally, as one type of image forming apparatus, a toner image on an image carrier (for example, a photosensitive drum) is
After the first transfer unit (for example, a primary transfer roller using a roller-shaped member) electrostatically transfers the image from the image carrier to an intermediate transfer body (for example, an intermediate transfer belt using a belt-shaped member), After the toner image on the intermediate transfer belt is again transferred from the intermediate transfer belt to a recording material such as recording paper by the second transfer means (for example, a secondary transfer roller using a roller-shaped member), the heat fixing means transfers the toner image onto the recording paper. An image forming apparatus that fixes the toner image of the image forming apparatus is used.

However, in the image forming apparatus of the above-mentioned type, it is desirable to stabilize the temperature conditions at which the intermediate transfer member is placed in the image forming device as much as possible. In order to stabilize the temperature of the intermediate transfer body and to suppress the change of the physical properties of the intermediate transfer body and the fusion of the toner to the intermediate transfer body, In order to suppress changes in physical properties such as values and mechanical strength, it is necessary to suppress local temperature rise as much as possible.

For this reason, conventionally, the distance between the heat fixing means and the intermediate transfer member is set as long as possible,
As disclosed in JP-A-153914, a heat shield is provided between the heat fixing means and the intermediate transfer body, or the intermediate transfer body is prevented from facing the opening of the heat fixing means, so that the intermediate transfer is performed. A method of suppressing a rise in body temperature has been adopted. Also, in the intermediate transfer method that performs simultaneous transfer fixing,
Providing a cooling unit between the first transfer unit and the second transfer unit;
A method of always cooling and suppressing a rise in the temperature of the intermediate transfer member is disclosed in JP-A-8-44220 and JP-A-9-258570.
No., for example.

[0005]

However, in the configuration in which the distance between the thermal fixing means and the intermediate transfer member is set as far as possible, and in the configuration disclosed in Japanese Patent Application Laid-Open No. 11-153914, the thermal fixing means is not provided. However, there is a problem in that the image forming apparatus is increased in size due to restrictions on the positional relationship and the distance between the intermediate transfer members, and the apparatus is complicated due to the installation of the heat shielding means. In the methods disclosed in JP-A-8-44220 and JP-A-9-258570, the intermediate transfer body is always cooled, which is not desirable from the viewpoint of energy consumption.

The present invention solves the above-mentioned problems, and entails an increase in the size of the image forming apparatus due to restrictions on the positional relationship and the distance between the heat fixing means and the intermediate transfer member, and an increase in the complexity of the apparatus due to the installation of heat shielding means. It is an object of the present invention to provide an image forming apparatus capable of suppressing a rise in temperature of an intermediate transfer member with a simple configuration and with a minimum energy.

[0007]

The object of the present invention is to provide a charging means for charging the image carrier around the image carrier, an image writing means for writing an image on the image carrier to form a latent image, Developing means for developing the latent image on the image carrier is provided to form a toner image on the image carrier, and the toner image formed on the image carrier is transferred by a first transfer means. Transferring the toner image from the image carrier to the intermediate transfer member, and transferring the toner image on the intermediate transfer member from the intermediate transfer member to a recording material by a second transfer unit. In the image forming apparatus that is fixed by the fixing unit, a temperature detecting unit is provided in contact with or in proximity to the intermediate transfer body, and at least one air discharging unit is provided in proximity to the intermediate transfer body, and the temperature detecting unit detects the temperature. Operate the exhaust means according to temperature To be achieved by an image forming apparatus according to claim (first invention) that.

[0008] Further, the object is to provide a charging means for charging the image carrier around the image carrier, an image writing means for writing an image on the image carrier to form a latent image, and the image carrier. Developing means for developing the upper latent image is provided to form a toner image on the image carrier, and the toner image formed on the image carrier is transferred to the image carrier by a first transfer means. After the toner image on the intermediate transfer member is transferred from the intermediate transfer member to the recording material by the second transfer unit, the toner image on the recording material is fixed by the heat fixing unit. In the image forming apparatus, a temperature detecting unit is provided in contact with or close to the intermediate transfer body, and an intermediate transfer body cooling unit that blows air to the intermediate transfer body is provided, and the intermediate transfer body is detected by the temperature detected by the temperature detecting unit. Operate the cooling means. It is achieved by an image forming apparatus according to claim (second invention).

The above object is also achieved by a charging means for charging the image carrier around the image carrier, an image writing means for writing an image on the image carrier to form a latent image, and the image carrier. Developing means for developing the upper latent image is provided to form a toner image on the image carrier, and the toner image formed on the image carrier is transferred to the image carrier by a first transfer means. After the toner image on the intermediate transfer member is transferred from the intermediate transfer member to the recording material by the second transfer unit, the toner image on the recording material is fixed by the heat fixing unit. In the image forming apparatus, a control unit provided in the image forming apparatus causes the image forming apparatus to operate for a predetermined time t1.
The image forming apparatus (third invention) is characterized in that, when it is detected that the intermediate transfer member is in the stop state during the period, the intermediate transfer member is rotated for a predetermined time t2.

The above object is also achieved by a charging means for charging the image carrier around the image carrier, an image writing means for writing an image on the image carrier to form a latent image, and the image carrier. Developing means for developing the upper latent image is provided to form a toner image on the image carrier, and the toner image formed on the image carrier is transferred to the image carrier by a first transfer means. After the toner image on the intermediate transfer member is transferred from the intermediate transfer member to the recording material by the second transfer unit, the toner image on the recording material is fixed by the heat fixing unit. A temperature detecting means for detecting the temperature of the intermediate transfer member at a portion where the temperature to be heated by the heat fixing means rises most, in contact with or close to the intermediate transfer member; When the device is in a stopped state, When the temperature detected by the temperature detecting means is detected to be equal to or higher than a predetermined temperature T1, the intermediate transfer body is rotated for a predetermined time t3. Achieved.

The above object is also achieved by a charging means for charging the image carrier around the image carrier, an image writing means for writing an image on the image carrier to form a latent image, and the image carrier. Developing means for developing the upper latent image is provided to form a toner image on the image carrier, and the toner image formed on the image carrier is transferred to the image carrier by a first transfer means. After the toner image on the intermediate transfer member is transferred from the intermediate transfer member to the recording material by the second transfer unit, the toner image on the recording material is fixed by the heat fixing unit. A temperature detecting means for detecting the temperature of the intermediate transfer member at a portion where the temperature to be heated by the heat fixing means rises most, in contact with or close to the intermediate transfer member; While the device is stopped, the temperature detection When it is detected that the temperature detected by the step has become equal to or higher than the predetermined temperature T1, the rotation of the intermediate transfer body is started, and the maximum temperature detected by the temperature detecting means for one rotation of the intermediate transfer body is equal to or lower than the predetermined temperature T2. The rotation of the intermediate transfer member is stopped when the condition (1) is reached.

[0012]

Embodiments of the present invention will be described below. Note that the description in this column does not limit the technical scope of the claims and the meaning of terms. Further, the following assertive description in the embodiment of the present invention indicates the best mode, and does not limit the meaning or technical scope of the terms of the present invention.

An image forming process and each mechanism of an embodiment of an image forming apparatus common to the claims of the present invention will be described.
This will be described with reference to FIG. FIG. 1 is a cross-sectional view of a main part of a color image forming apparatus showing an embodiment of an image forming apparatus common to the claims of the present invention.

According to FIG. 1, 10 is a photosensitive drum as an image carrier for each color, 11 is a charging roller as charging means for each color, 12 is an exposure optical system as image writing means for each color, Reference numeral 13 denotes a developing device as a developing unit for each color, 14a an intermediate transfer belt as an intermediate transfer member, and 14c a first transfer unit for transferring a toner image on an image carrier for each color to the intermediate transfer member. A secondary transfer roller 14g, a secondary transfer roller as a second transfer unit for retransferring the toner image on the intermediate transfer member onto a recording material; a fixing device 17 as a thermal fixing unit;
Reference numeral 190 denotes a photoconductor cleaning device as an image carrier cleaning unit for each color, and reference numeral 190a denotes an intermediate transfer member cleaning device as an intermediate transfer member cleaning unit.

In this embodiment, a photosensitive drum 10 as an image carrier for each color, a charging roller 11 as a charging unit for each color, and an exposure optical system 1 as an image writing unit for each color.
2. Developing device 13 as a developing device for each color and photoconductor cleaning device 190 as an image carrier cleaning device
Are provided as a set, four image forming units 100 are provided for each color of yellow (Y), magenta (M), cyan (C), and black (K), and counterclockwise indicated by an arrow in FIG. Are arranged in the order of Y, M, C, and K on the upper side of the intermediate transfer belt 14a with respect to the rotation direction of the intermediate transfer belt 14a according to the color to be formed and the order.

Photoconductor drum 10 as an image carrier for each color
Is formed by forming an organic photoreceptor layer (OPC) having an overcoat layer (protective layer) on the outer periphery of a cylindrical metal substrate formed of, for example, an aluminum material on the outer periphery of the metal substrate. In the grounded state, the photosensitive drum 10 for each color is rotated in a clockwise direction indicated by an arrow in FIG. 1 by a photosensitive member drive motor (not shown).

A charging roller 11 as charging means for each color
Is formed by coating a conductive core metal (not shown) of stainless steel or the like with a semiconductive elastic rubber (not shown) having a volume resistance of about 10 ⁵ to 10 ⁷ Ω · cm on a peripheral surface thereof. Drum 1
At the time of electrification of 0, it has the same polarity (minus polarity in this embodiment) as the toner used (toner at the time of development), and performs a charging operation (minus charge in this embodiment) by applying a charging bias of a DC voltage. , A uniform potential is applied to the photosensitive drum 10. Other charging means include
It is also possible to use a charging brush, a charging blade or a non-contact corona discharger of a contact charging type.

Exposure optical system 1 as image writing means for each color
2 is arranged around the photosensitive drum 10 such that the exposure position on the photosensitive drum 10 is located on the downstream side in the rotation direction of the photosensitive drum 10 with respect to the charging roller 11 for each color described above. . The exposure optical system 12 rotationally scans a laser beam emitted from a laser light source (not shown) with a rotary polygon mirror (not shown), and comprises an fθ lens (not shown), a reflection mirror (not shown), and the like, and is separate. Exposure (image writing) of the photoreceptor layer of the photoreceptor drum 10 in accordance with the image data of each color read by the image reading device and stored in the memory.
Then, an electrostatic latent image is formed on the photosensitive drum 10 for each color.

The developing device 13, which is a developing means for each color,
One-component developer or toner (in this embodiment, negative polarity) and carrier using yellow (Y), magenta (M), cyan (C), and black (K) toners in this embodiment using negatively charged toner in this embodiment. , Each of which contains a two-component developer, and which rotates in the developing position in the forward direction with respect to the rotation direction of the photosensitive drum 10 in contact with or non-contact with the peripheral surface of the photosensitive drum 10, for example, aluminum, stainless steel, etc. It is made of non-magnetic material such as steel.
A developing roller 131, which is a developer carrier that is rotatably supported with a roughened surface of 0.5 to 5 μm as indicated by a 10-point average roughness (JIS-B0610),
By applying a developing bias of a DC voltage or a DC voltage superimposed on an AC voltage to the developing roller 131, contact or non-contact reversal development is performed, and the toner image is formed on a latent image portion on the photosensitive drum 10. To form

The intermediate transfer belt 14a, which is preferably an intermediate transfer member using a belt shape, has a volume resistance of 10 ⁶ to 1.
An endless belt of 0 ¹² Ω · cm, for example, polycarbonate (PC), polyimide (PI), polyamide imide (PAI), polyvinylidene fluoride (PVD)
F), tetrafluoroethylene-ethylene copolymer (E
A resin material such as TFE) or a rubber material such as EPDM, NBR, CR, or polyurethane in which a conductive filler such as carbon is dispersed or an ionic conductive material is contained is used. 50-20 for material
The setting is preferably about 0 μm, and in the case of a rubber material, about 300 to 700 μm. Intermediate transfer belt 14a
Are stretched in contact with roller members such as a driving roller 14d, a driven roller 14e, a cleaning opposing roller 14f, a secondary transfer opposing roller 14j, and a tension roller 14i which are grounded. The drive roller 14d is rotated by the drive from M1, and the intermediate transfer belt 14a is rotated in the counterclockwise direction indicated by the arrow in FIG. The drive roller 14d is, for example, a rubber or resin material such as polyurethane, EPDM, silicone, etc.
A material coated with a conductive or semiconductive elastic body (no symbol) in which a conductive filler such as carbon is dispersed is used. As the intermediate transfer member, it is also possible to use a drum-shaped one in which a cylindrical core is covered with the above-mentioned member. In that case, a primary transfer is performed by applying a voltage to the cylindrical core of the intermediate transfer member.

A primary transfer roller 14c, which is a first transfer means for each color, is formed on a peripheral surface of a conductive core (not shown) made of, for example, stainless steel having an outer diameter of 8 mm by using polyurethane, EPDM, or the like.
By dispersing a conductive filler such as carbon or containing an ionic conductive material in a rubber material such as silicone or the like, a solid state having a volume resistance of about 10 ⁵ to 10 ⁹ Ω · cm or a foamed sponge state is obtained. And a semi-conductive elastic rubber (not shown) having a thickness of 5 mm and a rubber hardness of about 20 to 70 ° (Asker-C). The primary transfer roller 14c for each color faces the photosensitive drum 10 for each color with the intermediate transfer belt 14a interposed therebetween.
a, the intermediate transfer belt 14a
A transfer area (no symbol) is formed for each color between the toner image and the photosensitive drum 10 for each color, and the opposite polarity (positive polarity in the present embodiment) to the toner when the toner image is transferred to the intermediate transfer belt 14a. Then, a toner image on the photosensitive drum 10 for each color is transferred onto the intermediate transfer belt 14a by applying a primary transfer bias of a DC voltage to the conductive core metal (no symbol). As the first transfer unit, the above-mentioned contact system is preferably used, but it is also possible to use a non-contact corona transfer unit.

A secondary transfer roller 14 as a second transfer means for retransferring the color toner image on the intermediate transfer member onto a recording material.
g is, for example, a conductive filler such as carbon dispersed in a rubber material such as polyurethane, EPDM, or silicone, or a conductive filler such as ionic conductive material on a peripheral surface of a conductive core (not shown) such as stainless steel having an outer diameter of 8 mm. Including materials,
In a solid state or foamed sponge state having a volume resistance of about 10 ⁵ to 10 ⁹ Ω · cm, a thickness of 5 mm and a rubber hardness of 2
It is formed by covering a semiconductive elastic rubber (not shown) of about 0 to 70 ° (Asker-C). Secondary transfer roller 14
Since g is different from the primary transfer roller 14c and is in contact with the toner, the surface may be covered with a material having good releasability such as semiconductive fluororesin or urethane resin. Secondary transfer roller 14
g is opposed to the secondary transfer opposing roller 14j, which is grounded across the intermediate transfer belt 14a, and is provided in contact with (contact with) the intermediate transfer belt 14a.
A transfer area (no sign) is formed between the transfer roller 14j and the next transfer opposing roller 14j. At the time of re-transfer of the color toner image, the toner has the opposite polarity (positive polarity in this embodiment) to DC voltage of 2
By applying the next transfer bias, the superimposed color toner images on the intermediate transfer belt 14a are collectively transferred onto the recording paper P. As the second transfer means, the above-mentioned contact method is preferably used, but it is also possible to use a non-contact corona transfer device.

The heat fixing device 17 as a heat fixing means includes a fixing roller 17a having a heat source such as a halogen heater and a pressure roller 17a inside at least one of the rollers.
b, and applies heat and pressure between the fixing roller 17a and the pressure roller 17b to fix the toner image on the recording material.

The photoconductor cleaning device 190, which is an image carrier cleaning unit for each color, provided on the downstream side in the rotation direction of the photoconductor drum 10 from the transfer area of the primary transfer roller 14c for each color, The transfer residual toner on the photoconductor drum 10 for each color is cleaned by a photoconductor cleaning blade 191 which is a provided photoconductor cleaning member.

An intermediate transfer member cleaning device 190a, which is an intermediate transfer member cleaning means provided downstream of the transfer area of the secondary transfer roller 14g in the traveling direction of the intermediate transfer belt 14a, is a cleaning device that is grounded across the intermediate transfer belt 14a. The transfer residual toner on the intermediate transfer belt 14a is cleaned by an intermediate transfer member cleaning blade 191a which is provided opposite to the opposing roller 14f and is an intermediate transfer member cleaning member provided in the intermediate transfer member cleaning device 190a.

Next, the image forming process (image forming step) will be described. By starting a photoconductor drive motor (not shown) at the start of image recording, the photoconductor drum 10 of the yellow (Y) image forming unit 100 is rotated clockwise as indicated by an arrow in FIG. The application of a potential to the Y photoconductor drum 10 is started by the charging action.

After the Y photoreceptor drum 10 is applied with a potential, the Y exposure optical system 12 starts image writing with a first color signal, that is, an electric signal corresponding to the Y image data, and the Y photoreceptor drum 10 starts writing. Y of the original image on the surface of the body drum 10
An electrostatic latent image corresponding to the image is formed.

The latent image is reversely developed in a contact or non-contact state by a developing roller 131 of a Y developing device 13, and yellow (Y) is formed on the photosensitive drum 10 in accordance with the rotation of the Y photosensitive drum 10. ) Is formed.

The Y toner image formed on the Y photoreceptor drum 10 as the image carrier by the above-described image forming process is transferred to the Y transfer area (no symbol) in the Y transfer area (no symbol). The image is transferred onto the intermediate transfer belt 14a by the primary transfer roller 14c.

Next, the intermediate transfer belt 14a is synchronized with the Y toner image, and is given a potential by the charging operation of the M charging roller 11 by the magenta (M) image forming unit 100. The image writing is performed by the second color signal, that is, the electric signal corresponding to the M image data, and the developing roller 131 of the M developing device 13 is used.
The contact or non-contact reversal development of M causes the M toner image on the M photoreceptor drum 10 to be transferred to the M transfer area (no symbol) by the M primary transfer roller 14c as the first transfer means. The M toner image is formed by being superimposed on the Y toner image of FIG.

By a similar process, the image is synchronized with the superposed toner images of Y and M, and is formed by the third color signal formed on the photosensitive drum 10 of C by the image forming unit 100 of cyan (C). The C toner image corresponding to the C image data is transferred from above the Y and M toner images by the C primary transfer roller 14c, which is the first transfer unit, in the C transfer area (no symbol). A toner image of C is formed on the photosensitive drum 10 of K by the black (K) image forming unit 100 in synchronism with the toner image of Y, M, and C. The K toner image corresponding to the K image data based on the fourth color signal is represented by K
In the transfer area (no symbol), the above-mentioned Y, M, and C are transferred by the K primary transfer roller 14c as the first transfer unit.
Are formed on top of each other, and a superposed color toner image of Y, M, C and K is formed on the intermediate transfer belt 14a.

The untransferred toner remaining on the peripheral surface of the photoconductor drum 10 for each color after the transfer is brought into contact with the photoconductor drum 10 of the photoconductor cleaning device 190 which is an image carrier cleaning means for each color. Contact) state, the photosensitive member cleaning blade 191 which is a photosensitive member cleaning member
Is mechanically cleaned.

In synchronization with the formation of the superimposed color toner image on the intermediate transfer belt 14a, the recording paper P is fed from a paper feed cassette (not shown) as a recording material storage means via a timing roller 15b as a recording material feeding means. The toner is conveyed to a transfer area (no symbol) of a secondary transfer roller 14g, which is a second transfer unit, and a secondary transfer roller 14g to which a DC voltage having a polarity opposite to that of the toner (positive polarity in this embodiment) is applied. Then, the superimposed color toner images on the intermediate transfer belt 14a are collectively re-transferred onto the recording paper P.

The recording paper P on which the color toner image has been transferred is
The charge is removed by a charge removing electrode 16b, which is a separating means formed of a sawtooth electrode plate, conveyed to a heat fixing device 17, and heat and pressure are applied between a fixing roller 17a and a pressure roller 17b, so that the recording paper P After the toner image is fixed, the toner image is discharged to a tray (not shown) outside the apparatus.

The untransferred toner remaining on the peripheral surface of the intermediate transfer belt 14a after the transfer is an intermediate transfer member cleaning means which is an intermediate transfer member cleaning means provided opposite to the cleaning opposing roller 14f with the intermediate transfer belt 14a interposed therebetween. The apparatus 190a is mechanically cleaned by an intermediate transfer member cleaning blade 191a, which is an intermediate transfer member cleaning member that is brought into contact (contact) with the intermediate transfer belt 14a.

In the above, a configuration may be adopted in which monochrome image formation is performed using only one image forming unit and the intermediate transfer member.

Embodiment 1 The prevention of the temperature rise of the intermediate transfer member according to claims 1 to 7 of the present invention will be described with reference to FIGS.
FIG. 2 is an explanatory view of a method for preventing a rise in the temperature of the intermediate transfer member according to claims 1 to 7 of the present invention, and FIG.
FIG. 4 is a block diagram showing a control method for preventing a temperature rise of the intermediate transfer member.

According to FIG. 2, as described above with reference to FIG.
A charging roller 1 as charging means for charging the photosensitive drum 10 is provided around the photosensitive drum 10 as an image carrier for each color.
1. Exposure optical system 12, which is an image writing unit for writing an image on photosensitive drum 10 uniformly charged by charging roller 11 to form a latent image, and developing unit for developing a latent image on photosensitive drum 10. And a toner image formed on the photosensitive drum 10 for each color as a first transfer unit for each color. The primary transfer roller 14c transfers the toner image from the photosensitive drum 10 to an intermediate transfer belt 14a, which is preferably a belt-shaped intermediate transfer member, and transfers the toner image on the intermediate transfer belt 14a to a secondary transfer unit that is a second transfer unit. After the transfer from the intermediate transfer belt 14a to the recording paper P as a recording material by the roller 14g, at least one of the fixing roller 17a and the fixing roller 17a in which a heat source such as a halogen heater is disposed is pressed. The thermal fixing device 17 is a heat fixing means having a roller 17b, the image formation is performed by fixing the toner image on the recording sheet P. The untransferred toner remaining on the peripheral surface of the photoconductor drum 10 for each color after the transfer is in contact (contact) with the photoconductor drum 10 of the photoconductor cleaning device 190 which is an image carrier cleaning unit for each color. The cleaning is performed by a photoconductor cleaning blade 191 which is a photoconductor cleaning member. The transfer residual toner remaining on the peripheral surface of the intermediate transfer belt 14a after the transfer is an intermediate transfer body cleaning device, which is an intermediate transfer body cleaning unit provided opposite to the cleaning opposing roller 14f with the intermediate transfer belt 14a interposed therebetween. 190a
The cleaning is performed by an intermediate transfer member cleaning blade 191a, which is an intermediate transfer member cleaning member that is brought into contact (contact) with the intermediate transfer belt 14a.

Further, as shown in FIG. 2, the intermediate transfer belt 14a is heated by the heat fixing device 17 having a heat source. A temperature sensor TS1 is provided as a temperature detecting means for detecting the temperature of the intermediate transfer belt 14a in contact with or close to the transfer belt 14a, and measures (detects) the temperature of the intermediate transfer belt 14a.

In the above, as shown in FIG. 2, air is exhausted from the inside of the apparatus (inside the image forming apparatus) to a position adjacent to the heat fixing device 17 and the intermediate transfer belt 14a to cool the intermediate transfer belt 14a. Exhaust fan F1 as an exhaust means for the air is provided.

In the above, as shown in FIG. 4, the exhaust fan F1, which is an exhaust means, is operated through the control unit according to the temperature detected by the temperature sensor TS1 as the temperature detecting means for detecting the temperature of the intermediate transfer belt 14a. . At this time, the set temperature of the plurality of stages and the rotation speed of the exhaust fan F1 corresponding to the set temperatures of the plurality of stages are stored in advance in the ROM of the storage unit as a pair (reference table). When the temperature of the intermediate transfer belt 14a detected by the temperature sensor TS1 reaches the set temperature,
The rotational speed of the exhaust fan F1 is switched to change the amount of exhaust air. The amount of exhaust air from the exhaust fan F1 is set and controlled such that the amount of exhaust air increases at a higher set temperature (so that the rotation speed of the exhaust fan F1 increases).

As described above, the air discharging means for performing the air discharging operation by detecting the temperature of the temperature detecting means of the intermediate transfer body increases the size of the apparatus due to restrictions on the positional relationship and the distance between the heat fixing means and the intermediate transfer body. It is possible to suppress a rise in the temperature of the intermediate transfer member with minimum energy without complicating the apparatus by the heat shielding means. Further, it is possible to more accurately control the temperature rise of the intermediate transfer body due to the exhaust means by a plurality of stepwise controls.

In the above, as shown in FIG. 2, an intermediate transfer member cooling means for blowing air to the intermediate transfer belt 14a at a position adjacent to the intermediate transfer belt 14a to cool the intermediate transfer belt 14a. An intermediate transfer member cooling fan F2 is provided.

In the above, as shown in FIG. 4, the intermediate transfer member cooling fan F2 serving as the intermediate transfer member cooling unit is controlled by the temperature detected by the temperature sensor TS1 serving as a temperature detecting unit for detecting the temperature of the intermediate transfer belt 14a. Operate through parts. At this time, a plurality of set temperatures and a rotational speed of the intermediate transfer body cooling fan F2 corresponding to the plurality of set temperatures are previously stored in the ROM of the storage unit as a pair (reference table). With reference to the reference table, when the temperature of the intermediate transfer belt 14a detected by the temperature sensor TS1 reaches the set temperature, the rotation speed of the intermediate transfer body cooling fan F2 is switched to change the air blowing amount. The amount of air blown by the intermediate transfer member cooling fan F2 is set such that the air amount is increased at a higher set temperature (intermediate transfer member cooling fan F2).
2 so as to increase the rotation speed).
In the example of FIG. 4, the cooling effect is higher when the intermediate transfer belt 14a is rotated when the intermediate transfer member cooling fan F2 is turned on.

As described above, the intermediate transfer member cooling means, which performs the air blowing operation by detecting the temperature of the intermediate transfer member temperature detecting means, can increase the size of the apparatus due to restrictions on the positional relationship and the distance between the heat fixing means and the intermediate transfer member. Further, it is possible to suppress an increase in the temperature of the intermediate transfer member with minimum energy without complicating the apparatus by the heat shielding means. Further, it is possible to more accurately suppress the temperature rise of the intermediate transfer body by the intermediate transfer body cooling unit by a plurality of stepwise controls.

In the above description, as shown in FIG. 2, at least one of the roller members which stretches the intermediate transfer belt 14a, for example, a driven member downstream of a portion most adjacent to the heat fixing device 17 in FIG. The heat pipe HP is provided on the roller 14e. Further, as shown in FIG. 3, at the end of the heat pipe HP, air is exhausted from the heat pipe HP or air is blown to the heat pipe HP shown by a dashed line in FIG. 3 to cool the heat pipe HP. Heat pipe roller cooling fan F3 which is a heat pipe roller cooling means
Is provided.

In the above, as shown in FIG. 4, the heat pipe roller cooling fan F3 as the heat pipe roller cooling means is controlled by the temperature detected by the temperature sensor TS1 as the temperature detecting means for detecting the temperature of the intermediate transfer belt 14a. Operate through parts. At this time, the RO
The set temperatures of a plurality of stages and the rotation speed of the heat pipe roller cooling fan F3 corresponding to the set temperatures of the plurality of stages are stored in M as a pair (reference table), and the reference table is referred to. When the temperature of the intermediate transfer belt 14a detected by the sensor TS1 has reached the set temperature, the rotation speed of the heat pipe roller cooling fan F3 is switched to change the amount of exhaust air or the amount of air blown. The amount of exhaust air or the amount of air blown from the heat pipe roller cooling fan F3 is set so that the air amount increases at a higher set temperature (so that the rotation speed of the heat pipe roller cooling fan F3 increases).
Set and controlled.

Embodiment 2 The prevention of the temperature rise of the intermediate transfer member according to claims 8 to 18 of the present invention will be described with reference to FIG. 5 or FIG. 6 and FIG. FIG. 5 is an explanatory view of a method for preventing a temperature rise of the intermediate transfer member according to claims 8 to 18 of the present invention, and FIG. 6 is a view showing a method of cooling the cooling roller member of FIG.

According to FIG. 5, as described above with reference to FIG.
A charging roller 1 as charging means for charging the photosensitive drum 10 is provided around the photosensitive drum 10 as an image carrier for each color.
1. Exposure optical system 12, which is an image writing unit for writing an image on photosensitive drum 10 uniformly charged by charging roller 11 to form a latent image, and developing unit for developing a latent image on photosensitive drum 10. And a toner image formed on the photosensitive drum 10 for each color as a first transfer unit for each color. The primary transfer roller 14c transfers the toner image on the intermediate transfer belt 14a from the photosensitive drum 10 to the intermediate transfer belt 14a, which is an intermediate transfer member driven by an intermediate transfer member drive motor M1, preferably in a belt shape. Secondary transfer roller 14 as a second transfer unit
g, the image is transferred from the intermediate transfer belt 14a to a recording sheet P as a recording material, and at least one of the fixing rollers 17 is provided with a heat source such as a halogen heater therein.
The toner image on the recording paper P is fixed by the heat fixing device 17 which is a heat fixing unit having the a and the pressure roller 17b to form an image. Photoconductor drum 10 for each color after transfer
The transfer residual toner remaining on the peripheral surface of the photoconductor cleaning device 190 serving as an image carrier cleaning unit for each color.
Is mechanically cleaned by a photoconductor cleaning blade 191 which is a photoconductor cleaning member brought into contact (contact) with the photoconductor drum 10. As a result, the adhering matter charged on both the forward and reverse sides of the intermediate transfer belt 14a, which remains adhering even after passing through the transfer area of the primary transfer roller 14c, is favorably cleaned. The transfer residual toner remaining on the peripheral surface of the intermediate transfer belt 14a after the transfer is an intermediate transfer body cleaning device, which is an intermediate transfer body cleaning unit provided opposite to the cleaning opposing roller 14f with the intermediate transfer belt 14a interposed therebetween. 1
The intermediate transfer member 90a is mechanically cleaned by an intermediate transfer member cleaning blade 191a, which is an intermediate transfer member cleaning member brought into contact (contact) with the intermediate transfer belt 14a. Thereby, the adhered matter on the intermediate transfer belt 14a, which is charged on both the forward and reverse sides, which remains on even after the secondary transfer roller 14g passes through the transfer area, is favorably cleaned.

In the above, as shown in FIG. 4, the image is formed by the image forming program stored in the ROM of the storage unit. The intermediate transfer belt 14a is heated by the heat fixing device 17 having a heat source. Intermediate transfer belt 1
Since the temperature of the image forming apparatus 4a is increased, when the timer TM connected to the control unit detects that the image forming apparatus is in the stop state for a predetermined time t1, for example, for 3 minutes, the driving of the intermediate transfer member is performed. By driving the motor M1, the intermediate transfer belt 14a is set to a predetermined time t2, for example, 20 s.
During ec, it is controlled to rotate. At this time, a predetermined time t1 during which the image forming apparatus is stopped and a predetermined time t1 corresponding to the intermediate transfer belt 14 are stored in the ROM of the storage unit in advance.
When the image forming apparatus is stopped for a predetermined time t1 by storing the predetermined time t2 for driving a as a plurality of pairs (reference tables) or functions (function tables) and referring to the reference table or the function table. , The predetermined time t
In accordance with 1, the intermediate transfer belt 14a is set and controlled so as to be driven for a predetermined time t2. That is, when the set temperature of the fixing roller 17a having the heat source of the heat fixing device 17 is X, the intermediate transfer belt 14 is kept for a predetermined time t1 (X).
When a is in a stopped state, rotation starts, and by rotating for t2 (X), local heat of the intermediate transfer belt 14a is stopped. As the value of X is larger, the value of t1 is smaller,
The value of t2 is set to be large. At this time, while the intermediate transfer belt 14a is rotating, the primary transfer roller 14c, the secondary transfer roller 14g, and the intermediate transfer member cleaning blade 191a release the pressure contact (release the contact and separate them), as described later. Do. As a result, the temperature of the intermediate transfer member can be increased with a simple configuration without increasing the size of the device due to restrictions on the positional relationship and the distance between the heat fixing unit and the intermediate transfer member, and without complicating the device due to the heat shielding unit. It becomes possible to suppress.

Further, as shown in FIG. 5, a portion of the intermediate transfer belt 14a close to the heat fixing device 17 where the temperature of the intermediate transfer belt 14a heated by the heat fixing device 17 having a heat source rises most is as follows. Intermediate transfer belt 14a
The temperature sensor TS1 is provided as a temperature detecting means for detecting the temperature of the intermediate transfer belt 14a by contacting or approaching the intermediate transfer belt 14a, and measures (detects) the temperature of the intermediate transfer belt 14a.

In the above, as shown in FIG. 4, the image is formed by the image forming program stored in the ROM of the storage section. However, the intermediate transfer belt 14a is warmed by the heat fixing device 17 having a heat source. Intermediate transfer belt 1
Since the temperature of the image forming apparatus 4a is increased, the control unit determines that the image forming apparatus is in the stopped state, and the temperature sensor TS
1 is about 10 ° C. lower than the glass transition temperature Tg of the toner used, for example, 4
When it is detected that the temperature has reached 5 ° C. or more, the intermediate transfer member driving motor M1 is driven to control the intermediate transfer belt 14a to rotate for a predetermined time t3, for example, for 30 seconds. At this time, the predetermined temperature T1 of the intermediate transfer belt 14a and the predetermined temperature T1 are stored in advance in the ROM of the storage unit.
And a predetermined time t3 for driving the intermediate transfer belt 14a is stored as a plurality of pairs (reference tables), and when the intermediate transfer belt 14a reaches a predetermined temperature T1, the predetermined time is referred to. According to the temperature T1,
The intermediate transfer belt 14a is set and controlled so as to be driven for a predetermined time t3. At this time, while the intermediate transfer belt 14a is rotating, as described later, the primary transfer roller 14c, the secondary transfer roller 14g, and the intermediate transfer body cleaning blade 1
Reference numeral 91a performs pressure release (release of contact and separation). Thereby, the portion of the intermediate transfer member whose temperature has risen is brought into contact with the drive roller 14d or the driven roller 14e of the intermediate transfer belt 14a having a low temperature to release the heat, so that the heat fixing means and the intermediate transfer member can be cooled. The temperature rise of the intermediate transfer body can be suppressed with a simple configuration without increasing the size of the apparatus due to restrictions on the positional relationship, distance, and the like, and without complicating the apparatus due to heat shielding means. In particular, it is possible to suppress a local temperature rise of the intermediate transfer member.

As shown in FIG. 5, the intermediate transfer belt 14a is heated by the heat fixing device 17 having a heat source. A temperature sensor TS1 is provided as a temperature detecting means for detecting the temperature of the intermediate transfer belt 14a in contact with or close to the transfer belt 14a, and measures (detects) the temperature of the intermediate transfer belt 14a.

In the above, as shown in FIG. 4, the image is formed by the image forming program stored in the ROM of the storage section. However, the intermediate transfer belt 14a is warmed by the heat fixing device 17 having a heat source. Intermediate transfer belt 1
Since the temperature of 4a is increased, the control unit determines that the image forming apparatus is in the stopped state, and the temperature detected by the temperature sensor TS1 is set to the predetermined temperature T1, which is about 10 ° C. lower than the glass transition temperature Tg of the toner to be used. Low, eg 45 ° C
When it is detected that the above has occurred, the intermediate transfer member drive motor M1 is driven to rotate the intermediate transfer belt 14a. Then, the maximum temperature detected by the temperature sensor TS1 of the intermediate transfer belt 14a when the intermediate transfer belt 14a makes one rotation is equal to or lower than the glass transition temperature Tg-15 ° C. (Tg-15 ° C.) of the used toner, for example, as the predetermined temperature T2. Control, the rotation of the intermediate transfer belt 14a is stopped. At this time, the predetermined temperature T1 of the intermediate transfer belt 14a and the intermediate transfer belt 1 are stored in the ROM of the storage unit in advance.
The predetermined temperature T2, which is the maximum detected temperature for one rotation of the intermediate transfer belt 4a, is stored as a plurality of pairs (reference tables), and when the intermediate transfer belt 14a reaches the predetermined temperature T1, the intermediate transfer belt is referred to. The rotation and rotation of the intermediate transfer belt 14a are set and controlled so that the rotation of the intermediate transfer belt 14a is stopped when the temperature of the intermediate transfer belt 14a falls below the predetermined temperature T2. At that time, the intermediate transfer belt 14
a, the primary transfer roller 14 is rotated as described later.
c, the secondary transfer roller 14g and the intermediate transfer member cleaning blade 191a release the pressure contact (release the contact and separate them). Thereby, the portion of the intermediate transfer member whose temperature has risen is brought into contact with the drive roller 14d or the driven roller 14e of the intermediate transfer belt 14a having a low temperature to release the heat, so that the heat fixing means and the intermediate transfer member can be cooled. It is possible to suppress the temperature rise of the intermediate transfer body with a simple configuration and with minimum energy without increasing the size of the device due to restrictions on the positional relationship, distance, etc., and without complicating the device due to heat shielding means. Becomes In particular, it is possible to suppress a local temperature rise of the intermediate transfer member.

In the above, as shown in FIG. 5, a belt-shaped intermediate transfer belt 14a is preferably used as the intermediate transfer member, and the intermediate transfer belt 14a is a driving roller 14d, a driven roller 14e, and a cleaning opposite roller which are respectively grounded. 14f, it is stretched in contact with roller members such as the secondary transfer opposing roller 14j and the tension roller 14i, and at the time of image formation, the drive roller 14d is rotated by the drive from the intermediate transfer member drive motor M1. At least one of the roller members that stretches the transfer belt 14a, for example, in FIG. 5, heat fixing is performed between a position where the intermediate transfer belt 14a is close to the heat fixing device 17 and a position where the intermediate transfer belt 14a is in contact with the photosensitive drum 10. The driven roller 14e, which is disposed closest to the apparatus 17 and is easily heated, is moved from the intermediate transfer belt 14a to the driven roller 14e. Conducting well (greater thermal conductivity),
It is also preferable to use a thick metal roller, such as an aluminum material, having a larger heat capacity than the intermediate transfer belt 14a to act as a cooling roller member. Thus, the temperature rise of the belt-shaped intermediate transfer body is released by contacting the heated portion of the intermediate transfer body with a low-temperature cooling roller member or an image carrier, thereby suppressing the temperature rise of the intermediate transfer body. In particular, it is possible to suppress a local temperature increase of the intermediate transfer member.

Further, as shown in FIG. 6, the end of the driven roller 14e used as a cooling roller member is subjected to exhaust air from the driven roller 14e or air blowing to the driven roller 14e shown by a dashed line in FIG. An air exhaust fan F11 is provided as a means for exhausting the driven roller 14e for cooling the driven roller 14e used as a cooling roller member, and the air is discharged from the driven roller 14e or blows to the driven roller 14e. An amount for cooling the driven roller 14e used as a cooling roller member is measured. This makes it possible to efficiently release the heat of the belt-shaped intermediate transfer member by the cooling roller member, and to cool the belt-shaped intermediate transfer member more effectively.

In the above, the intermediate transfer belt 14a
When the intermediate transfer belt 14a is rotated to cool the intermediate transfer belt 14a, as shown by a dotted line in FIG.
It is preferable to separate the primary transfer roller 14c, which is in contact with the photoconductor drum 10 with the “a” therebetween, from the photoconductor drum 10 (to release the contact between the photoconductor drum 10 and the intermediate transfer belt 14a). Also, the secondary transfer facing roller 14j
When the intermediate transfer belt 14a is rotated to cool the intermediate transfer belt 14a, the intermediate transfer belt 14a is separated from the intermediate transfer belt 14a as shown by a dotted line in FIG. 5 (the contact with the intermediate transfer belt 14a is released). Is preferred.
Further, on the downstream side in the rotation direction of the intermediate transfer belt 14a from the transfer area of the secondary transfer opposed roller 14j, the intermediate transfer belt 1
An intermediate transfer member cleaning blade 191a that is provided in contact with the intermediate transfer member 4a and is an intermediate transfer member cleaning member that removes untransferred toner and attached matter on the intermediate transfer belt 14a.
When the intermediate transfer belt 14a is rotated to cool the intermediate transfer belt 14a, the intermediate transfer belt 14a is separated from the intermediate transfer belt 14a as shown by a dotted line in FIG. 5 (the contact with the intermediate transfer belt 14a is released). Is preferred.
This makes it possible to suppress wear of the intermediate transfer body and the image carrier, and wear of the second transfer means and the intermediate transfer body cleaning member.

In the above description, as shown in FIG. 5, a temperature detecting means for detecting the temperature of the heat fixing device 17 by bringing the heat fixing device 17 into contact with or close to, for example, a fixing roller 17a provided with a heat source. Temperature sensor TS2
And measures (detects) the temperature of the heat fixing device 17. As shown in FIG. 4, an image is formed by an image forming program stored in a ROM of a storage unit. The intermediate transfer belt 14a is heated by a heat fixing device 17 having a heat source, and the temperature of the intermediate transfer belt 14a is increased. Is raised to cool the intermediate transfer belt 14a, and the temperature set by the temperature sensor TS2 of the heat fixing device 17 is set to, for example, 150.
In the same manner as described above, when the timer TM connected to the control unit detects that the image forming apparatus is in the stop state for the predetermined time t1, for example, for 4 minutes, the intermediate transfer is performed. The body drive motor M1 is driven to set the intermediate transfer belt 14a to a predetermined time t2, for example, 40
It is controlled to rotate during sec. At this time, a plurality of set temperatures and a predetermined time t corresponding to the plurality of set temperatures, at which the image forming apparatus is stopped, are previously stored in the ROM of the storage unit.
1 and a predetermined time t2 for driving the intermediate transfer belt 14a
Are stored as a plurality of values (a reference table of a predetermined time t1 and a predetermined time t2 corresponding to a plurality of set temperatures), and a reference is made to the reference table to correspond to the set temperatures of a plurality of stages. Then, when the image forming apparatus is stopped for the predetermined time t1, the setting and control are performed such that the intermediate transfer belt 14a is driven for the predetermined time t2. That is, the heat fixing device 1
Assuming that the set temperature of the fixing roller 17a having the heat source of No. 7 is X, the intermediate transfer belt 14a for a predetermined time t1 (X)
Is stopped, the rotation is started, and the rotation is performed for t2 (X) to stop the local heat of the intermediate transfer belt 14a. The larger the value of X, the smaller the value of t1
2 is set to be large. At this time, while the intermediate transfer belt 14a is rotating, as described above, the primary transfer roller 14c, the secondary transfer roller 14g, and the intermediate transfer member cleaning blade 191a are released from the pressure contact (the contact is released,
To separate). This makes it possible to suppress a rise in the temperature of the intermediate transfer body with a minimum necessary rotation according to the set temperature of the heat fixing unit.

As described above, when the image forming apparatus is stopped, the intermediate transfer member is rotated, and the heated portion of the intermediate transfer member is brought into contact with a low-temperature image carrier or the like, thereby releasing heat. A simple configuration and minimal energy can be used for the intermediate transfer body without increasing the size of the apparatus due to restrictions on the positional relationship and distance between the heat fixing means and the intermediate transfer body, and without complicating the apparatus due to the heat shielding means. Temperature rise can be suppressed. In particular, it is possible to suppress a local temperature rise of the intermediate transfer member.

[0060]

According to the first aspect of the present invention, the air discharging means for performing the air discharging operation by detecting the temperature of the temperature detecting means of the intermediate transfer body is restricted by the positional relationship and the distance between the heat fixing means and the intermediate transfer body. The increase in the temperature of the intermediate transfer member can be suppressed with minimum energy without increasing the size of the apparatus or complicating the apparatus due to the heat shielding means.

According to the second aspect, the rise in the temperature of the intermediate transfer body caused by the air discharging means is suppressed more accurately.

According to the third aspect, the intermediate transfer member cooling means, which performs the blowing operation by detecting the temperature of the intermediate transfer body temperature detecting means, uses the apparatus based on restrictions such as the positional relationship and the distance between the heat fixing means and the intermediate transfer body. Without the increase in size and the complexity of the device due to heat shielding means, and with minimum energy,
It is possible to suppress an increase in the temperature of the intermediate transfer member.

According to the fourth aspect, the temperature rise of the intermediate transfer member caused by the intermediate transfer member cooling means can be more accurately suppressed.

According to the fifth aspect, it is possible to suppress a temperature rise of the belt-shaped intermediate transfer member.

According to the sixth aspect, the belt-shaped intermediate transfer member can be effectively cooled by the heat pipe roller cooling means.

According to the seventh aspect, the temperature rise of the intermediate transfer body is suppressed more accurately by the heat pipe roller cooling means.

According to the present invention, when the image forming apparatus is stopped for a predetermined time t1, the intermediate transfer member is rotated for a predetermined time t2, so that the position of the heat fixing means and the position of the intermediate transfer member are determined. The temperature rise of the intermediate transfer body can be suppressed with a simple configuration without increasing the size of the device due to restrictions on the relationship or the distance, and without complicating the device due to the heat shielding means.

According to the ninth aspect, the temperature detecting means of the intermediate transfer member accurately detects a state where the temperature rise of the intermediate transfer member in the portion close to the heat generating portion such as the heat fixing means has become equal to or higher than the predetermined temperature T1. Then, by rotating the intermediate transfer member for a predetermined time t3, a portion where the temperature of the intermediate transfer member has risen is brought into contact with a low-temperature image carrier or the like to release heat, thereby allowing the intermediate transfer member and the heat fixing unit to rotate. The temperature rise of the intermediate transfer member can be suppressed with a simple configuration without increasing the size of the device due to restrictions on the positional relationship and distance of the transfer member, and without complicating the device due to heat shielding means. In particular, it is possible to suppress a local temperature rise of the intermediate transfer member.

According to the tenth aspect, the temperature detecting means accurately detects a state where the temperature rise of the intermediate transfer body in the portion close to the heat generating portion such as the heat fixing means has become equal to or higher than the predetermined temperature T1, and the intermediate transfer is performed. The rotation of the body and the maximum temperature detected by the temperature detecting means for one rotation of the intermediate transfer body is a predetermined temperature T
When the temperature becomes 2 or less, the rotation of the intermediate transfer member is stopped, thereby releasing the heat by contacting the heated portion of the intermediate transfer member with an image carrier having a low temperature. A simple configuration and minimal energy can be used for the intermediate transfer body without increasing the size of the apparatus due to restrictions on the positional relationship and distance between the heat fixing means and the intermediate transfer body, and without complicating the apparatus due to the heat shielding means. Temperature rise can be suppressed. In particular, it is possible to suppress a local temperature rise of the intermediate transfer member.

According to the eleventh or twelfth aspect, the cooling roller member is provided between the portion where the belt-shaped intermediate transfer member comes close to the heat fixing means and the portion where the belt-shaped intermediate transfer member comes into contact with the image carrier, so that the belt-shaped intermediate transfer member is provided. Heat is released by bringing the heated portion of the intermediate transfer member into contact with a low-temperature cooling roller member or image carrier, thereby limiting the positional relationship and distance between the heat fixing unit and the intermediate transfer member. The increase in the temperature of the intermediate transfer member can be suppressed with a simple configuration and with minimum energy without increasing the size of the apparatus or complicating the apparatus due to the heat shielding means. In particular, it is possible to suppress a local temperature rise of the intermediate transfer member.

According to the thirteenth aspect, the cooling roller member is made of a member having a higher heat conductivity and a larger heat capacity than the belt-shaped intermediate transfer member, so that the heat of the belt-shaped intermediate transfer member can be efficiently discharged. It is possible to escape.

According to the fourteenth aspect, the cooling of the belt-shaped intermediate transfer member by the cooling roller member is more effectively performed.

According to Claims 15 to 17, when rotating the intermediate transfer member, the intermediate transfer member and the image carrier are used, the intermediate transfer member and the second transfer means are used, and the intermediate transfer member and the intermediate transfer member are rotated. By separating the cleaning member from the cleaning member, it is possible to suppress abrasion of the intermediate transfer body and the image carrier, and abrasion of the second contact transfer unit and the intermediate transfer body cleaning member.

According to the eighteenth aspect, according to the set temperature of the heat fixing means, the predetermined time t is determined by the set temperature of the heat fixing means.
By changing the times of t1 and t2, it is possible to suppress the temperature rise of the intermediate transfer body with the minimum necessary rotation according to the set temperature of the heat fixing unit.

[Brief description of the drawings]

FIG. 1 is a cross-sectional configuration diagram of a main part of a color image forming apparatus showing an embodiment of an image forming apparatus common to the claims of the present invention.

FIG. 2 is an explanatory diagram of a method for preventing a temperature rise of an intermediate transfer member according to claims 1 to 7 of the present invention.

FIG. 3 is a diagram illustrating a method of cooling the heat pipe of FIG. 2;

FIG. 4 is a control block diagram of a temperature rise prevention control of the intermediate transfer member.

FIG. 5 is an explanatory diagram of a method for preventing a rise in temperature of an intermediate transfer member according to claims 8 to 18 of the present invention.

FIG. 6 is a diagram illustrating a method of cooling the cooling roller member of FIG. 5;

[Explanation of symbols]

 Reference Signs List 10 photosensitive drum 11 charging roller 12 exposure optical system 13 developing device 14a intermediate transfer belt 14c primary transfer roller 14e driven roller 14g secondary transfer roller 17 heat fixing device 131 developing roller 190 photosensitive member cleaning device 190a intermediate transfer member cleaning device 191 Photoconductor cleaning blade 191a Intermediate transfer member cleaning blade F1, F11 Ventilation fan F2 Intermediate transfer member cooling fan F3 Heat pipe roller cooling fan HP heat pipe M1 Intermediate transfer member drive motor P Recording paper TM Timer TS1, TS2 Temperature sensor

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H027 DA13 DE10 EC06 ED24 EF09 JB17 JB20 JB23 JB24 JC03 JC08 2H032 AA05 BA09 BA23 BA25 3J103 AA02 BA03 BA12 BA43 FA01 FA15 FA19 FA20 GA02 GA52 GA57 GA58 GA60 9A001 JJ06H

Claims (18)

[Claims] A charging unit configured to charge the image carrier around the image carrier, an image writing unit configured to write an image on the image carrier to form a latent image, and a latent image on the image carrier. Developing means for developing the toner image, forming a toner image on the image carrier, and intermediately transferring the toner image formed on the image carrier from the image carrier by a first transfer means. An image forming apparatus that transfers the toner image on the intermediate transfer member to a recording material by a second transfer unit from the intermediate transfer member to a recording material, and then fixes the toner image on the recording material by a heat fixing unit In the above, a temperature detecting unit is provided in contact with or in proximity to the intermediate transfer member, and at least one air discharging unit is provided in proximity to the intermediate transfer member, and the air discharging unit is operated based on a temperature detected by the temperature detecting unit. Image characterized by Forming equipment. 2. The air discharge amount of the air discharge means can be controlled in a plurality of stages, and the air discharge amount of the air discharge means increases as the temperature detected by the temperature detection means increases. Item 2. The image forming apparatus according to Item 1. 3. A charging unit for charging the image carrier around the image carrier, an image writing unit for writing an image on the image carrier to form a latent image, and a latent image on the image carrier. Developing means for developing the toner image, forming a toner image on the image carrier, and intermediately transferring the toner image formed on the image carrier from the image carrier by a first transfer means. An image forming apparatus that transfers the toner image on the intermediate transfer member to a recording material by a second transfer unit from the intermediate transfer member to a recording material, and then fixes the toner image on the recording material by a heat fixing unit In the above, a temperature detecting unit is provided in contact with or close to the intermediate transfer member, and an intermediate transfer member cooling unit that blows air to the intermediate transfer member is provided, and the intermediate transfer member cooling unit is operated according to a temperature detected by the temperature detecting unit. Image characterized by Image forming device. 4. The method according to claim 1, wherein the amount of air blown by the intermediate transfer body cooling unit is controllable in a plurality of stages, and the amount of air blown by the intermediate transfer body cooling unit is increased as the temperature detected by the temperature detection unit becomes higher. The image forming apparatus according to claim 3, wherein: 5. The image forming apparatus according to claim 1, wherein the intermediate transfer member has a belt shape. 6. At least one of the roller members that stretches the intermediate transfer member is formed of a heat pipe roller, and blows or exhausts air to an end of the heat pipe roller.
The image forming apparatus according to claim 5, further comprising a heat pipe roller cooling unit that cools an end of the heat pipe roller. 7. The air volume or air volume of the heat pipe roller cooling means can be controlled in a plurality of stages,
The image forming apparatus according to claim 6, wherein the higher the temperature detected by the temperature detector, the greater the amount of air blown by the heat pipe roller cooling unit or the amount of air blown. 8. A charging means for charging the image carrier around the image carrier, an image writing means for writing an image on the image carrier to form a latent image, and a latent image on the image carrier. Developing means for developing the toner image, forming a toner image on the image carrier, and intermediately transferring the toner image formed on the image carrier from the image carrier by a first transfer means. An image forming apparatus that transfers the toner image on the intermediate transfer member to a recording material by a second transfer unit from the intermediate transfer member to a recording material, and then fixes the toner image on the recording material by a heat fixing unit In the above, when the control unit provided in the image forming apparatus detects that the image forming apparatus is in a stop state for a predetermined time t1, the intermediate transfer body is rotated for a predetermined time t2. An image forming apparatus comprising: 9. A charging device for charging the image carrier around the image carrier, an image writing device for writing an image on the image carrier to form a latent image, and a latent image on the image carrier. Developing means for developing the toner image, forming a toner image on the image carrier, and intermediately transferring the toner image formed on the image carrier from the image carrier by a first transfer means. An image forming apparatus that transfers the toner image on the intermediate transfer member to a recording material by a second transfer unit from the intermediate transfer member to a recording material, and then fixes the toner image on the recording material by a heat fixing unit A temperature detecting unit that detects the temperature of the intermediate transfer member at a portion where the temperature heated by the heat fixing unit is the highest, which is brought into contact with or close to the intermediate transfer member, wherein the image forming apparatus is in a stopped state And the temperature detecting means When due detected temperature is detected that it is now more than a predetermined temperature T1, between the intermediate transfer member for a predetermined time t3, the image forming apparatus characterized by rotating. 10. A charging device for charging the image carrier around the image carrier, an image writing device for writing an image on the image carrier to form a latent image, and a latent image on the image carrier. Developing means for developing the toner image, forming a toner image on the image carrier, and intermediately transferring the toner image formed on the image carrier from the image carrier by a first transfer means. An image forming apparatus that transfers the toner image on the intermediate transfer member to a recording material by a second transfer unit from the intermediate transfer member to a recording material, and then fixes the toner image on the recording material by a heat fixing unit A temperature detecting unit that detects a temperature of the intermediate transfer body at a portion where a temperature heated by the thermal fixing unit is the highest, which is brought into contact with or close to the intermediate transfer body, while the image forming apparatus is stopped. The detection by the temperature detection means When it is detected that the temperature has become equal to or higher than the predetermined temperature T1, the rotation of the intermediate transfer body is started, and the maximum temperature detected by the temperature detection unit for one round of the intermediate transfer body has become equal to or lower than the predetermined temperature T2. An image forming apparatus, wherein the rotation of the intermediate transfer member is stopped sometimes. 11. The image forming apparatus according to claim 8, wherein the intermediate transfer member has a belt shape. 12. A cooling roller member, one of the roller members that stretches the intermediate transfer member, wherein the intermediate transfer member contacts the image carrier from a position close to the heat fixing unit. The image forming apparatus according to claim 11, wherein the image forming apparatus is disposed between the image forming apparatus and the image forming apparatus. 13. The image forming apparatus according to claim 12, wherein the cooling roller member has better heat conduction than the intermediate transfer member, and has a larger heat capacity than the intermediate transfer member. 14. The image forming apparatus according to claim 13, wherein the air discharging means of the image forming apparatus is disposed adjacent to an end of the cooling roller member. 15. When rotating the intermediate transfer body,
The image forming apparatus according to claim 8, wherein the contact between the image carrier and the intermediate transfer member is released. 16. The image forming apparatus according to claim 16, wherein the second transfer unit that transfers the toner image on the intermediate transfer member from the intermediate transfer member to the recording material is provided in contact with the intermediate transfer member, and rotates the intermediate transfer member. The image forming apparatus according to any one of claims 8 to 15, wherein, when performing the operation, the contact of the second transfer unit with the intermediate transfer body is released. 17. A method according to claim 17, wherein the intermediate transfer body is brought into contact with the intermediate transfer body at a position downstream of a transfer area of a second transfer unit in which a toner image is transferred from the intermediate transfer body to the recording material. An intermediate transfer member cleaning member is provided for removing transfer residual toner and attached matter on the intermediate transfer member. When the intermediate transfer member rotates, the contact of the intermediate transfer member cleaning member with the intermediate transfer member is released. The image forming apparatus according to any one of claims 8 to 16, wherein the image forming apparatus is configured to: 18. The image forming apparatus according to claim 1, wherein the predetermined times t1 and t2 are changed according to a set temperature of the heat fixing unit.