JP2003005563A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the satisfaction of both a user who is strict with image staining and a user who wants to obtain a print quickly rather than to be strict with some staining. SOLUTION: This image forming device has a fixing device 26 constituted of a pair of rollers 261 and 264 for holding and heating recording material P on which an unfixed toner image is carried, and a cleaning roller 277 abutting on the roller 264. A cleaning operation is performed in which, after finishing forming the image at the time of performing consecutive recording by the specified number of sheets or more, energizing of the heater 274 of the roller 261 is turned off in a state where the rollers are not rotated for a specified time t1 and energizing of the heater 274 is turned on in a state where the rollers are rotated for a specified time t2 after the specified time t1 elapses. Thereafter, the cleaning operation is additionally performed in response to user's designation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus provided with fixing means for fixing an unfixed toner image on a recording material carrying the unfixed toner image.

[0002]

2. Description of the Related Art In an image forming apparatus using an electrophotographic system such as a laser printer, a heater such as a halogen lamp and a plate-shaped resistor is used as a heating means, and a roller or a film containing the heating means is used as a pressure roller. A fixing method is generally used in which a recording material is nipped and pressed by a pressing means while being heated and fixed.

An image forming apparatus and a fixing device will be described with reference to FIGS. 2 and 3. 2 is a schematic sectional view of the image forming apparatus, and FIG. 3 is a schematic sectional view of the fixing device.

First, the operation of the image forming apparatus 1 will be described with reference to FIG. In FIG. 2, reference numeral 21 is a photosensitive drum made of OPC, which rotates in the R1 direction. A charging roller 22 uniformly charges the photoconductor drum 21. 23
Is a laser beam modulated by image information sent from a personal computer (PC) or the like and is emitted from the laser unit 32 through a mirror 35 to form a latent image according to the image on the photosensitive drum 21. 24 is the photoconductor drum 21
This is a developing device that visualizes the latent image above. 27 is a cleaner for cleaning the developer remaining after transfer. The above is integrated to form the process cartridge 33.

A transfer roller 25 is fed from a cassette 34, and a registration roller 28 transfers the visible image at a nip portion N to a recording material P synchronized with the visible image on the photosensitive drum 21.

The image on the recording material P is fixed as a permanent image by the fixing device 26 and is ejected outside the device by the paper ejection roller 31. In the figure, 29 and 30 are conveyance guides for assisting the conveyance of the recording material P.

Next, the fixing device 26 will be described with reference to FIG. The fixing roller 261 is a core metal 2 made of iron or aluminum.
A mold release layer 263 such as PFA / PTFE is coated on 62. The pressure roller 264 is composed of a core metal 265 made of iron, stainless steel or the like and an elastic layer 266 made of silicon sponge or the like.
Further, a release layer 267 made of fluororesin or the like in which conductive particles such as carbon are finely dispersed is further provided on the elastic layer 266, and is pressed against the fixing roller 261 by a pressing spring 272. The temperature of the heater 274 is controlled by the temperature detecting element 268,
The toner T on the recording material P is fixed. 273 is an inlet guide, 269 is a separation claw, 270 is a paper ejection guide, 271
Is a discharge roller.

Reference numeral 275 is a fixing bias power source, and a core metal 2
It is connected to 62. This prevents the offset phenomenon that causes the toner charge and the repulsive force, and the toner adheres to the surface of the fixing roller to cause a defect in the subsequent image.
Here, the toner has a negative polarity.

Reference numeral 276 denotes a diode element, which is connected between the pressure roller core metal and GND so that the pressure roller core metal side is the cathode and the main body GND side is the anode. As a result, the potential of the pressure roller core metal is prevented from becoming negative, a potential difference is created between the surface of the fixing roller and the pressure roller core metal, and the electric field prevents the offset phenomenon from the recording material to the fixing roller.

Further, the release layer 267 is, as described above,
It is adjusted so that it has a constant resistance value. This is because peeling discharge charges generated between the trailing edge of the recording material and the surface of the fixing roller are dropped to the main body GND through the surface of the pressure roller at the moment when the trailing edge of the recording material leaves the fixing roller.

A cleaning roller 277 is provided for the purpose of collecting the offset toner adhering to the fixing roller 261 via the pressure roller 264. The cleaning roller 277 is made of a metal such as aluminum or iron. The principle of toner recovery is that the cleaning roller is inferior in releasability as compared with the fixing roller and the pressure roller provided with the release layer.

[0012]

In the image forming apparatus having the above-described structure, although a certain effect is exerted in preventing the offset, as a result of the study by the present inventors, the image is formed under the following conditions. It has been found that when the forming operation is performed, the recording material is soiled although the frequency is low.

The condition is that one printing is repeated with a long interval and a short interval, and in addition, a paper containing a large amount of calcium carbonate as a filler is used as a recording material.

In addition, at the place where this stain occurs, the toner collected in the separation claw 269 drops on the recording material, and the toner collected by the cleaning roller 277 flows backward to the pressure roller and the fixing roller, and the recording material. I also found out that it was to move to.

Further, it was also found that the above-mentioned dirty toner is liable to be generated at the timing when the long print is temporarily stopped and then restarted.

In view of this point, the present inventor has shown the following measures. That is, after the image forming operation for continuous printing of a predetermined number of sheets or more, the heater is turned off in a non-rotating state for a predetermined time t1, and after the predetermined time t1 has passed, the heater is in a rotating state for a predetermined time t2. To turn on the power to the heater, and to extend the time to turn on the power to the heater in the rotating state before the image forming operation at the time of the next image forming operation after the continuous printing of a predetermined number or more is completed, Is. As a result, most of the above problems can be solved.

However, even if the above measures are taken, there are various recording materials in the world market, and the stain is not strictly zero depending on the paper type, and it may be better for the user to remove the stain a little more. Some people find it irritating. Therefore, it is desirable to have a configuration that can satisfy various users.

Therefore, an object of the present invention is to enhance the satisfaction of both users who are strict about image stains and users who want to print faster than some stains.

[0019]

A typical constitution of the present invention for achieving the above object is to provide at least a pair of rotating bodies for nipping and heating a recording material carrying an unfixed toner image, and at least one of the rotating bodies. In an image forming apparatus having a fixing unit composed of a rotating body for toner recovery that is in contact with one rotating body,
After the image formation in the continuous recording of a predetermined number of sheets or more, during a predetermined time t1, the rotating body is in the non-rotating state, and the power supply to the heating body of at least one of the rotating bodies is turned off for a predetermined time. After the lapse of t1, perform a cleaning operation for turning on the power supply to the heating body in a rotating state for a predetermined time t2, and then additionally perform the cleaning operation according to a user's designation. Is characterized by.

With the above-described structure, the dirt containing the toner as a main component, which has accumulated on the pair of rotating bodies, is collected on the toner collecting rotating body and from the toner collecting rotating body on the pair of rotating bodies. Contamination mainly containing the toner that has flowed back to the toner collecting body is enhanced by the toner collecting rotary member.

Since the cleaning operation can be additionally performed according to the user's designation, both the user who is strict about image stain and the user who wants to print sooner than a little stain are satisfied. be able to.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be illustratively described in detail below with reference to the drawings. However,
The dimensions, materials, shapes, relative arrangements, and the like of the component parts described in the following embodiments should be appropriately changed depending on the configuration and various conditions of the device to which the present invention is applied, and are particularly specific. Unless otherwise stated, the scope of the present invention is not intended to be limited thereto.

[First Embodiment] An image forming apparatus including a fixing device according to the first embodiment will be described in detail. Figure 1
3 is a flowchart illustrating a process of an engine controller that controls the operation of the image forming apparatus 1.

Although the image forming apparatus 1 has the structure shown in FIG. 2, its schematic structure has been described above, and a detailed description thereof will be omitted here. Here, the paper feed cassette 34 is 7
It is possible to mount 500 sheets of recording material of 5 to 80 g / m 2.

Further, the fixing device 26 as the fixing means has the structure shown in FIG. 3 described above, but specifically, the following is used.

In FIG. 3, the fixing device 26 is A3 (29
7 mm) is an example of a central reference in which a recording material having a maximum paper-passing width is conveyed with the paper-feed center of the apparatus as a reference, and the heater 274 as a heating body is one that has a rated output of 1 kW at 100 V input. The heater light distribution has a flat distribution with respect to the paper passing standard. The fixing roller 261 which is a rotating body has a core metal 262 of aluminum and a diameter of 40 m.
It is a roller having a thickness of 2.0 mm and a thickness of 2.0 mm, and has a surface layer covered with a release layer 263 of PFA. A pressure roller 264, which is a rotating body forming a pair with the fixing roller 261, has an elastic layer 266 of silicon sponge on a stainless steel core 265 and a release layer 267 of PFA on the surface layer, and has a diameter of 30 mm and a product hardness of 50 °. 2 is used by the pressure spring 272.
By applying a pressing force of 00N, a nip width of 5.0 mm can be created between the fixing roller 261 and the fixing roller 261. Separation claw 2
69 is a longitudinal direction (axial direction orthogonal to the recording material conveyance direction)
6 of them are arranged. The temperature detecting element 268 is installed outside the image area. With this configuration, it is possible to print 24 sheets / minute with A4 transverse feed.

A fixing bias power source 275 applies -600 V to the fixing roller core metal. 276 is a diode element having a reverse breakdown voltage of 2 kV. Numeral 277 is a cleaning roller which is a rotating body for toner recovery made of pure Al having a diameter of φ10.
4 is driven to rotate. The cleaning roller 277 is fixed between the shafts so as to bite into the pressure roller 264 by about 0.7 mm, and a nip width of 1.0 mm can be formed.

In the present embodiment, first, a non-recording heating rotation process (cleaning sequence) which is performed after continuous printing of a predetermined number or more is described. This will be explained with reference to the model diagram shown in FIG.

FIG. 4 is a schematic view showing the states of the four fixing devices (a), (b), (c) and (d).

FIG. 4A shows a state of the fixing device after performing long continuous printing. A mass of offset toner is generated in the vicinity of the contact portion of the separation claw 269 with the fixing roller 261. On the cleaning roller 277, the toner collected from the pressure roller 264 partially adheres in a solid state. When long continuous printing is performed, the pressure roller 264 and the cleaning roller 277 are used.
This is because the temperature does not rise until the toner is completely melted.

FIG. 4B shows the state immediately after the start of the cleaning rotation. The toner accumulated on the separation claw 269 is released from the separation claw 269 when the fixing device is activated. This is because the temperature of the contact interface between the toner accumulated in the separation claw 269 and the separation claw 269 becomes low after a lapse of a certain time after printing, so that the toner is easily released from the separation claw 269. Further, a part of the toner that has adhered to the cleaning roller 277 in a clumped state is released from the cleaning roller 277 and flows back onto the pressure roller 264.

FIG. 4C shows a state during the cleaning rotation. Since the heating rotation is performed without passing the paper, the toner released from the separation claw 269 on the fixing roller 261 is softened, and the toner moves to the pressure roller 264 due to the difference in releasing property and the temperature difference. To do. The heating roller warms the pressure roller 264 and the cleaning roller 277, so that the toner flowing back from the cleaning roller 277 is softened and collected on the cleaning roller 277. Further, the toner transferred from the fixing roller 261 to the pressure roller 264 is also collected by the cleaning roller 277. Then, the toner collected on the cleaning roller 277 becomes smooth so as to be leveled.

FIG. 4D shows a state where the cleaning rotation is stopped. The toner on the fixing roller 261 and the toner on the pressure roller 264 are collected on the cleaning roller 277 through the processes of FIGS. 4A to 4C, and the collected toner has a smooth surface.

In this process, after the continuous printing of a predetermined number of sheets or more, a predetermined time t1 from the end of printing,
This is realized by stopping rotation of the fixing device and stopping the fixing heater, and then rotating the fixing device while adjusting the print temperature for a predetermined time t2.

Then, next, the predetermined number of sheets and the predetermined time t1,
A method of setting t2 will be described. These are set by performing a test using the image forming apparatus 1.

First, in order to determine the predetermined number of sheets, the relationship between the number of continuous image sheets and the separation claw stain was examined (test 1).

Canon LESER 80 (A4 size, 80 g / m2) containing about 19% calcium carbonate as a filler in a low temperature and low humidity (15 ° C-10% RH) environment.
2) A predetermined number of recording materials are continuously passed with a text image with a print ratio of 4%, and one recording material is passed after the image forming operation is completed, so that stains and cleaning of the recording material due to separation claws occur. Staining due to backflow of toner from the roller was confirmed. The results of Test 1 are shown in Table 1. 1 in Table 1
Numerical values such as 6 indicate how many of the 6 separating claws have been soiled.

[0038]

[Table 1]

According to the results of Test 1, it is found that the image stains due to the separating claws occur on 70 pages or more, and the stains due to the backflow toner from the cleaning roller occur on 250 pages or more. Therefore, it is desirable to set the predetermined number of pages to 70 pages or less. Therefore, in the present embodiment, the predetermined number is 70.

Next, an experiment for determining the predetermined time t1 was conducted (test 2).

Canon LESER 80 (A4 size, 80 g / m2) containing about 19% of calcium carbonate as a filler in a low temperature and low humidity (15 ° C-10% RH) environment.
2) The recording material was continuously passed 500 times with a text image having a printing ratio of 4%. After passing the paper, the apparatus was left in a standby state for a predetermined time t1, then one recording material was passed, and the stains on the recording material were observed. The results of Test 2 are shown in Table 2. In Table 2, the numerical values such as 1/6 are
It shows how many of the six separating claws have been soiled.

[0042]

[Table 2]

From the results of Test 2, it was found that the release of the toner from the separation claw needs t1 of at least 10 seconds or more. Contamination due to backflow from the cleaning roller did not seem to correlate with t1. Therefore, in this embodiment, the margin is set using the result of toner release from the separation claw, and t1 = 15 seconds.

Next, an experiment for determining the predetermined time t2 was conducted (test 3).

The test method is low temperature and low humidity (15 ° C-10%).
RH) environment, about 19% calcium carbonate as a filler
Included Canon LESER80 (A4 size,
80 g / m 2) 500 sheets of recording material were continuously passed with a text image having a printing ratio of 4%. And 15 seconds (=
t1), after leaving the apparatus in the standby state, cleaning rotation (non-recording heating rotation process shown in FIG. 4) was performed at 190 ° C. for print temperature control for a predetermined time t2. After that, one sheet of recording material was passed and the stains on the recording material were observed. The results of Test 3 are shown in Table 3. In Table 3, the numerical values such as 1/6 indicate how many of the six separating claws have been soiled. In the above-mentioned Test 2, since the backflow toner from the cleaning roller did or did not stain, the test was conducted using only the stain that occurred this time.

[0046]

[Table 3]

From the results of Test 3, it was found that the release of the toner from the separation claw needs t2 of at least 8 seconds or more. It was found that the contamination due to the backflow from the cleaning roller requires t1 of at least 4 seconds or more. Therefore, in this embodiment, the margin is set by using the result of toner release from the separation claw, and t2 = 8 seconds.

From the above test results, the predetermined number of pages = 70 pages, time t1 = 15 seconds, time t2 = 8 seconds,
The automatic cleaning sequence after continuous printing is shown in the flowchart of FIG. Hereinafter, description will be made with reference to FIG.

In step S51, a print signal is received. In step S52, it is determined whether or not continuous printing of 70 pages or more. If YES, step S5
3, the process proceeds to step S58 if NO. In steps S53 and S58, a normal print operation is performed. That is, the main motor is rotating and the fixing heater controls the print temperature. In step S54, printing ends. In step S55, both the main motor and the fixing heater are turned off for 15 seconds (= t1). Step S56
, Both main motor and fixing heater for 8 seconds (= t
2) Turn on. In steps S57 and S59, the process returns to the standby state.

By carrying out the automatic cleaning sequence as described above, a certain cleaning effect can be obtained.

The purpose of the present embodiment is to presuppose the automatic cleaning sequence as described above, and to additionally perform the cleaning operation selectively according to the user's preference in order to further enhance the cleaning effect. .

In the present embodiment, an example will be shown in which after performing the cleaning sequence after continuous printing of a predetermined number of sheets or more, the cleaning operation is re-executed according to the user's designation.

In this embodiment, the image forming apparatus 1 sets an automatic cleaning completion flag indicating that the automatic cleaning has been executed when the above-described automatic cleaning is executed. When the automatic cleaning completion flag is set, the automatic cleaning is performed by the last print on the external control device (or the operation panel of the image forming device) such as a personal computer (PC) connected to the image forming device 1. The user is informed of information (for example, a print setting screen) indicating that the printing has been performed.

The user who is shown on the PC that the automatic cleaning has been performed can select whether or not to perform the cleaning operation again according to his / her preference.
This user has the option to re-execute the cleaning operation.
A personal computer (P
This is performed from an external control device such as C) (or an operation panel of the image forming apparatus). Then, the image forming apparatus 1 performs the cleaning operation again according to the user's designation and then shifts to the print operation, or directly shifts to the print operation.

The above is described with reference to the flow chart shown in FIG. Incidentally, step S11 above the dotted line in FIG.
~ Step S13 is the operation of the printer driver on the PC,
Steps S14 to S16 below the dotted line show the operation of the image forming apparatus 1.

Now, the user is inputting print information on the PC in order to execute printing. On the print condition setting screen, it is confirmed whether the automatic cleaning flag is set (step S11). If YES, the process proceeds to step S12. If NO, the process proceeds to step S14. In step S12, it is selected whether to instruct the recleaning operation. If YES, go to step S13,
A recleaning operation command is issued to the image forming apparatus. If NO, the process proceeds to step S14. The above is the operation on the PC.

Next, the image forming apparatus 1 checks whether or not a recleaning operation command is received from the PC (step S14). If YES, proceed to step S15,
Perform a cleaning sequence. Then, after execution of the cleaning sequence, the process proceeds to step S16, and a normal print operation is performed. If NO in step S14, the flow advances to step S16 to execute a normal print operation without executing the cleaning sequence.

The cleaning sequence of step S15 in FIG. 1 is shown in FIG. Since step S61 and step S62 in FIG. 6 are the same as step S55 and step S56 described above with reference to FIG. 5, description thereof will be omitted here.

By implementing the above, a cleaning sequence can be added according to the user's preference, so that it is possible to meet the demands of both users who are strict about image stains or who want to print faster than some stains. , Satisfaction of various users can be improved.

[Second Embodiment] An image forming apparatus having a fixing device according to the second embodiment will be described in detail. still,
The schematic configurations of the image forming apparatus 1 and the fixing device 26 are the same as the configurations described with reference to FIGS. 2 and 3, and thus the description thereof is omitted here.

In the present embodiment, an example is shown in which during the next printing operation after the cleaning sequence has been carried out after the continuous printing of a predetermined number of sheets or more, the printing operation is interrupted in accordance with the user's designation and the cleaning sequence is carried out. .

In the above-described first embodiment, the user can select whether or not to perform the additional cleaning sequence when setting the print conditions when making a print request to the image forming apparatus.

In this embodiment, when the user sees an actual print sample discharged from the image forming apparatus for the first time after printing with the image forming apparatus and finds an image stain, the image is reproduced again according to the user's preference. It is possible to select whether or not to carry out the cleaning sequence.

Regarding the specific operation of the image forming apparatus 1,
This will be described with reference to the flowchart of FIG. FIG. 7 shows the next in-printing operation of the image forming apparatus 1 after the cleaning sequence is performed after continuous printing of a predetermined number or more.

In step S71 and step S72, the image forming apparatus 1 monitors whether the recleaning operation is instructed or the printing is completed. Here, as a method for the user to instruct the re-cleaning operation, an operation panel (not shown) provided in the image forming apparatus 1 is used. Of course, it may be performed by remote control or the like on the PC screen connected to the image forming apparatus 1. If the re-cleaning operation is not instructed in step S71 (NO) and the predetermined printing is finished in step S72 (YES), the printing operation is finished.

If it is determined in step S71 that the recleaning operation has been instructed (YES), step S73.
And the printing operation is interrupted. For example, if this print is an instruction to continuously print 100 pages and a recleaning operation is instructed during the printing of the 5th page, the printing operation of the remaining 95 pages is performed after the printing of the 5th page. Is to suspend once.

Step S74 is the cleaning sequence shown in FIG. After the cleaning sequence is performed, the remaining printing before the interruption is restarted in step S75. In the case of the above example, the printing of the sixth page is started. This step S73, step S7
4, step S75 can be performed as many times as possible according to the user's instruction.

By doing so, it is possible to further enhance the degree of satisfaction for the user who attaches importance to the print quality.

In the present embodiment, the example in which the print being printed is interrupted and the re-cleaning sequence can be selectively executed has been described. However, the interruption is not interrupted and the printing may be restarted from the beginning. good.

Further, in the above-described first and second embodiments, there is no particular limitation on the state of the image forming apparatus 1 after the cleaning sequence is carried out after the continuous printing of the predetermined number or more. This is because the present invention can be applied not only to the states that the image forming apparatus 1 can take, that is, the standby state and the sleep state, but also to the state in which the power is shut down after the continuous printing of a predetermined number or more and then the power is turned on.

[Third Embodiment] An image forming apparatus including a fixing device according to a third embodiment will be described in detail. still,
The schematic configurations of the image forming apparatus 1 and the fixing device 26 are the same as the configurations described with reference to FIGS. 2 and 3, and thus the description thereof is omitted here.

In the present embodiment, after performing the cleaning sequence after the continuous printing of a predetermined number or more, during the additional cleaning operation and the next printing operation, the printing during printing is interrupted or interrupted according to the user's designation. An example in which the time of the cleaning operation to be stopped and carried out is set according to the user's request will be described.

Specific examples are shown in FIGS. 8 and 9. 8 and 9 are the same as those of the flowchart of FIG. 1 shown in the first embodiment and the flowchart of FIG. 7 shown in the second embodiment, respectively, where the step S numbers are the same. It is a thing. In FIG. 8, steps S83 and S85 are respectively steps S13 and S of FIG.
Different from 15. In FIG. 9, step S96 is added after step S73, and step S94 is different from step S74 of FIG.

In step S83 of FIG. 8, the re-cleaning operation is instructed, and the fixing device stop time and the fixing temperature adjusting time of the image forming apparatus 1 in the cleaning operation are set. Upon receiving this setting, the operation is actually performed in step S85.

Similarly, in step S96 of FIG. 9, the fixing device stop time and the fixing temperature adjustment time of the image forming apparatus 1 are set, and upon receiving these settings, the operation actually starts in step S94.

According to the result of examination by the present inventors, it has been found that the time of this re-cleaning operation is shorter than the basic cleaning operation time. This is because the cleaning is performed once, and the amount of stains is reduced. However, since the cleaning effect can be improved by lengthening the cleaning operation time, the setting time is not particularly limited here, and the user may appropriately set the setting time as necessary. .

[Other Embodiments] In the above-described embodiment,
An example of an image forming apparatus capable of forming a monochrome image has been described.
The present invention is not limited to this, and the same effect can be obtained by applying the present invention to an image forming apparatus capable of forming a color image, for example.

In the above-described embodiment, the process cartridge detachable from the image forming apparatus main body is used.
Although the process cartridge integrally including the photosensitive drum and the charging unit, the developing unit, and the cleaning unit as the process unit acting on the photosensitive drum has been illustrated, the present invention is not limited to this, and other than the photosensitive drum. The process cartridge may integrally include any one of the charging unit, the developing unit, and the cleaning unit.

Further, in the above-described embodiment, the process cartridge including the photosensitive drum is detachably attached to the main body of the image forming apparatus. However, the present invention is not limited to this, and each component is incorporated, for example. Alternatively, the image forming apparatus may be an image forming apparatus in which each component is detachable.

Further, in the above-described embodiment, the printer is exemplified as the image forming apparatus, but the present invention is not limited to this, and other image forming apparatuses such as a copying machine and a facsimile machine, and their functions. A composite type image forming apparatus in which the above are combined may be applied, and the same effect can be obtained by applying the present invention to the image forming apparatus.

[0081]

As described above, according to the present invention,
Since the cleaning operation can be additionally performed according to the user's designation, it is possible to enhance the satisfaction of both the user who is strict about image stains and the user who wants to print faster than some stains.

[Brief description of drawings]

FIG. 1 is a flowchart of a recleaning operation according to a first embodiment.

FIG. 2 is a schematic cross-sectional view of an image forming apparatus including a fixing device.

FIG. 3 is a schematic sectional view of a fixing device.

FIG. 4 is a schematic diagram showing a cleaning action.

FIG. 5 is a flowchart showing a cleaning sequence.

FIG. 6 is a flowchart showing an additional cleaning sequence.

FIG. 7 is a flowchart of a recleaning operation according to the second embodiment.

FIG. 8 is a flowchart relating to the setting content of the recleaning operation of the third embodiment.

FIG. 9 is a flowchart related to the setting content of the recleaning operation of the third embodiment.

[Explanation of symbols]

N ... Nip part P ... Recording material T ... Toner 1 ... Image forming apparatus 21 ... Photosensitive drum 22 ... Charging roller 23 ... Laser light 24 ... Developer 25 ... Transfer roller 26 ... Fixer 27 ... Cleaner 28 ... Registration roller 29, 30 ... Transport guide 31 ... Ejection roller 32 ... Laser unit 33 ... Process cartridge 34 ... Cassette 35… Mirror 261 ... Fusing roller 262 ... core metal 263 ... Release layer 264 ... Pressure roller 265 ... Core metal 266 ... Elastic layer 267 ... Release layer 268 ... Temperature sensing element 269 ... Separation claw 270 ... Paper ejection guide 271 ... Ejection roller 272 ... Pressure spring 273 ... Entrance guide 274 ... Heater 275 ... Fixing bias power supply 276 ... Diode element 277 ... Cleaning roller

Continued front page    F term (reference) 2H027 DA39 DA46 ED25 EE01 EE02                       EE04 EE07 EE08 EE09 EF09                       EF11 EJ15 FA10                 2H033 AA08 BA49 BB17 CA19 CA20                       CA40 CA45 CA48

Claims (4)

[Claims] 1. A fixing unit comprising a pair of rotating members for nipping and heating a recording material carrying an unfixed toner image, and a toner collecting rotating member in contact with at least one of the rotating members. In the image forming apparatus, the rotating body is in the non-rotating state for a predetermined time t1 after the image formation when the continuous recording of a predetermined number or more is completed, and the heating body of at least one of the rotating bodies is energized. Is turned off, and after the elapse of a predetermined time t1, a cleaning operation is performed for a predetermined time t2 in which the rotating body is in a rotating state and energization to the heating body is turned on, and then the cleaning operation is performed according to a user's instruction. An image forming apparatus characterized by performing an additional operation. 2. A fixing means comprising a pair of rotating members for nipping and heating a recording material carrying an unfixed toner image, and a toner collecting rotating member in contact with at least one of the rotating members. In the image forming apparatus, the rotating body is in a non-rotating state for at least a predetermined time t1 after the image formation at the time of continuous recording of a predetermined number of sheets or more, and the heating body of at least one of the rotating bodies is energized. Is turned off, and after a lapse of a predetermined time t1, a cleaning operation is performed for a predetermined time t2 in which the rotating body is in a rotating state and energization to the heating body is turned on. An image forming apparatus, which interrupts or cancels the recording operation and additionally executes the cleaning operation according to a designation. 3. A predetermined time t1 accompanying the cleaning operation,
The predetermined time t2 and the number of cleaning operations can be set according to the user's preference.
Alternatively, the image forming apparatus according to claim 2. 4. The user designation is performed from an external control device connected to the image forming apparatus or an operation panel provided in the image forming apparatus.
The image forming apparatus according to claim 3.