JP2003140504A - Fixing device, and control method for fixing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an economical control method for a cleaning device and the cleaning device, by which offset toner is prevented from passing through, while the consumption of a cleaning web is reduced. SOLUTION: The cleaning device is equipped with a supply part 81 feeding the cleaning web 56 to a fixing roller 30, a pressing part 71 pressing the web 56 to the roller 30, a temperature detection sensor 82 detecting the temperature of the roller 30, an integration counter 64 integrating the driving time of the roller 30, and a web controller 60 controlling the driving of the supply part 81. When the sensor 82 consecutively detects temperature showing a specified value or under for a fixed time in the midst of driving the fixing device 32, the controller 60 feeds the cleaning web from the supply part 81 in a reset time shorter than a reference set time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device control method and a fixing device.

[0002]

2. Description of the Related Art In an electrophotographic image forming apparatus,
First, an electrostatic latent image is formed by irradiating optical image information such as reflected light of an original on a photoconductor that has been uniformly charged in advance so as to eliminate charges corresponding to the amount of exposure light. continue,
A toner image formed by attaching toner to the electrostatic latent image is transferred onto a transfer paper, and then the transfer paper is conveyed to a fixing device and heated and pressed to transfer the toner image onto the transfer paper. Establish. The heat roller fixing device includes a fixing roller having a heater therein, and a pressure roller that rotates while being in pressure contact with the peripheral surface of the fixing roller,
The toner image is thermally fixed by passing a transfer paper (transfer material) holding the unfixed toner image through the nip portion of both rollers.

By the way, since the peripheral surface of the fixing roller is a portion which comes into contact with the toner image on the transfer paper, it is covered with a fluororesin layer or the like having a good releasability so that foreign matters such as toner and paper dust are attached. Although it is considered to prevent it, in reality, it is not possible to completely prevent the adhesion of toner and the like. In particular, when the set temperature of the fixing roller is too high, an offset phenomenon occurs in which the toner once attached to the transfer paper is peeled off and attached to the fixing roller side. If the toner or the like adheres to and accumulates on the peripheral surface of the fixing roller, the fixing performance may be deteriorated and further toner adhesion may be accumulated, which may cause deterioration of image quality.

For this reason, various methods for appropriately cleaning the peripheral surface of the fixing roller have been conventionally proposed.
For example, as this type of cleaning means, generally, a roller system in which a cleaning member composed of a roller is brought into contact with the peripheral surface of the fixing roller, a felt system in which a cleaning member composed of a felt is brought into sliding contact with the fixing roller, and further, is wound around a delivery roller. There is known a web system or the like in which the peripheral surface of the fixing roller is cleaned by the web while the web is wound by the winding roller. Among these methods, the web method is superior in performance to other methods, and thus has been widely used in recent years.

As a web type cleaning device for feeding the web toward the peripheral surface of the fixing roller, a new portion of the web is applied to the peripheral surface of the fixing roller each time the fixing device completes a series of fixing jobs. Conventionally, a cleaning device for a fixing device has been proposed that performs a web winding operation (web feeding operation) for feeding and cleaning a web (for example, JP-A-11-24484).

In such a conventional web type cleaning apparatus, the fixing roller is stopped after the end of the previous job, and the tension applied when the web which is in sliding contact with the fixing roller is rotated is released. Therefore, a slight deviation occurs between the web and the fixing roller. Due to this misalignment, the toner may slip through the next rotation of the fixing roller. Also, if there is considerable time until the next job, the fixing roller temperature will drop to around the standby temperature,
A part of the adhered toner existing between the web and the fixing roller may be solidified to some extent. Therefore, there is a possibility that the solidified toner, which rotates the fixing roller again in the next job, may slip between the web and the fixing roller.

Further, even when the temperature of the fixing roller becomes lower than a predetermined value due to continuous paper passing or environmental conditions, the toner is easily solidified, and the offset toner on the fixing roller increases. In this case, the amount of toner blocked by the web will exceed the expected amount,
The web may not be able to hold the toner, and the toner may slip through.

That is, the offset toner wiped off the web does not slip through the toner if the fixing roller is continuously rotating, but as described above, the fixing roller is stopped,
If the temperature drops or the like, the toner slippage cannot be sufficiently suppressed.

Further, when a jam of the transfer material occurs, unfixed toner is likely to adhere to the fixing roller, and when the jam transfer material is forcibly removed, the web is loosened, which also passes through the toner. Cause to occur.

As an ideal control of the cleaning device for dealing with such a problem, it is desirable to remove the offset toner wiped by the web before the temperature of the web is cooled down. It is preferable to control to wind each time.

[0011]

However, if the cleaning device is controlled so as to constantly supply a new web, the consumption of the web will be increased unnecessarily, resulting in waste. There is also a maintenance problem of frequently changing the web.

The present invention has been made in view of the above-mentioned problems and requirements in the prior art. It is possible to prevent the offset toner from slipping through, and to provide an economical fixing device that consumes less web. An object is to provide a control method and a fixing device.

[0013]

According to a first aspect of the present invention, there is provided a web supply means for performing at least one of cleaning the peripheral surface of the fixing roller and applying oil, and directing the web toward the peripheral surface of the fixing roller. A pressing unit that presses, a temperature detecting unit that detects the temperature of the fixing roller, a counting unit that integrates the driving time of the fixing roller, and a control unit that controls the driving of the supplying unit are provided. A method of controlling a fixing device that feeds a web from a supply unit each time a set reference set time is reached, in which the temperature detection unit continuously detects a temperature equal to or lower than a predetermined value for a certain period while the fixing device is being driven. In addition, the control means is characterized in that the web is fed from the supply means in a reset time shorter than the reference set time.

According to the first aspect of the invention, when the count value of the counting means reaches the reference set time, the feeding means feeds the unused web toward the peripheral surface of the fixing roller under the control of the control means. The pressing means presses the web toward the peripheral surface of the fixing roller to clean the peripheral surface of the fixing roller.

When the temperature control means continuously detects a temperature equal to or lower than a predetermined value for a certain time during driving of the fixing device, that is, when the temperature of the fixing roller continues to decrease, the toner is solidified and fixed. The offset toner on the roller is often increased, and the web cannot stop the offset toner and the toner easily slips through.

In such a case, the control means feeds the web from the feeding means in a shortened set time shorter than the reference set time, that is, earlier than the reference set time, so that the offset toner blocked by the web. Can be prevented, and toner can be prevented from slipping through. Therefore, it is possible to prevent the transfer material from being contaminated due to the toner slipping through. Further, since the unused web is not always supplied, the consumption of the web can be reduced, which is economical.

According to a second aspect of the invention, in the first aspect of the invention, when the temperature detecting means continuously detects a temperature equal to or lower than a predetermined value for a predetermined time during driving of the fixing device, When the driving is completed, and the count value of the counting means is equal to or longer than the reset time, the feeding means feeds the web.

In the invention described in claim 2, claim 1
When the fixing roller stops due to the end of the driving of the fixing device, the same tension and tension as the rotation of the web that was in sliding contact with the fixing roller are released, and the web and the fixing roller are released. Since a slight deviation easily occurs between the web and the fixing roller, if the amount of toner between the web and the fixing roller is large, the toner may slip through when the fixing roller is rotated next time. Since the web is sent out earlier than the reference set time after the fixing device is driven, the transfer material can be prevented from being contaminated due to the toner slipping through.

The invention described in claim 3 is the invention according to claim 1 or 2.
In the invention described in (1), when the temperature detection unit continuously detects a temperature equal to or lower than a predetermined value during driving of the fixing device for a certain period of time, when a jam occurs, the count value of the counting unit is equal to or longer than the reset time. When there is, the web is sent out from the supply means.

According to the invention of claim 3, claim 1
Or, the same effect as the invention described in 2 is obtained, and when a jam occurs, the unfixed toner often adheres to the fixing roller. In such a case, the control means is earlier than the reference set time. Since the unfixed toner on the fixing roller can be removed by the web by feeding the web to the sheet, it is possible to prevent the transfer material from being soiled by the unfixed toner attached to the fixing roller.

The invention according to claim 4 is the invention according to claim 1 or 2.
In the invention described in (1), when the temperature detecting unit continuously detects a temperature equal to or lower than a predetermined value for a predetermined time during driving of the fixing device, the count value of the counting unit is equal to or more than the reset time at the end of the print job. At this time, the web is sent out from the supply means.

In the invention described in claim 4, claim 1
Alternatively, the same effect as that of the invention described in 2 is obtained, and at the end of the print job, unfixed toner often adheres to the fixing roller. In such a case, the control means is earlier than the reference set time. By feeding the web, the unfixed toner on the fixing roller can be removed by the web, so that the transfer material can be prevented from being soiled by the unfixed toner attached to the fixing roller.

According to a fifth aspect of the invention, in the invention according to the third aspect, the web is sent out from the supply means after the fixing roller has rotated once during the returning operation of the fixing device after removing the jammed paper. It is characterized by

According to the invention of claim 5, claim 3
While exhibiting the same effects as the invention described in (1), when the jammed paper is removed, the jammed paper and the fixing roller rub against each other, which may cause unfixed toner on the jammed paper to adhere to the fixing roller. The unfixed toner is removed after being blocked by the web while the fixing roller makes one rotation during the returning operation, and thus the transfer material is prevented from being soiled by the unfixed toner attached to the fixing roller during the jam processing.

The invention described in claim 6 is the invention according to claims 1 to 4.
In the invention described in any one of (1) to (5), the reset time can be set for each paper type.

In the invention described in claim 6, claim 1
The same effect as the invention described in any one of 4 to 4 can be obtained, and the resetting time can be set for each paper type.
When a jam occurs or when a print job ends, the web can be effectively driven according to the paper type, and therefore the consumption of the web can be reduced.

The invention according to claim 7 is the same as claims 1 to 6.
In any one of the inventions, when the temperature detecting means continuously detects a temperature below a predetermined value for a certain period of time before a print job or a jam occurs, a shortened set time that is equal to or longer than the reset time and equal to or shorter than the reference set time. It is characterized in that the web is sent out from the supply means.

In the invention described in claim 7, claim 1
If the temperature detecting means continuously detects a temperature equal to or lower than a predetermined value for a certain period of time while the fixing device is being driven, the same effect as that of the invention described in any one of 1 to 6 can be obtained. Offset toner is often increasing due to the decrease in temperature. In such cases,
Since the web is sent out earlier than the reference set time, it is possible to prevent the offset toner attached to the fixing roller from attaching to the transfer material being fed.

According to an eighth aspect of the present invention, in the invention according to the sixth aspect, the normal temperature and the lower limit temperature of the fixing temperature can be set for each paper type, and the standard setting for sending the web from the feeding means based on these settings. The feature is that the time and the shortened set time can be set.

According to the invention described in claim 8,
The same effect as that of the invention described above can be obtained, and the normal temperature and the lower limit temperature of the fixing temperature can be set in advance for each paper type, and the standard setting time and the shortening setting time are set based on these settings. In this way, the standard setting time and the shortening setting time for sending out the web can be set according to the type of paper used, so that the consumption of the web can be reduced and it is economical.

According to a ninth aspect of the present invention, a web supply means for performing at least one of cleaning the peripheral surface of the fixing roller and oil application, and pressing means for pressing the web toward the peripheral surface of the fixing roller. The temperature sensor is configured to detect the temperature of the fixing roller, the counting unit that integrates the driving time of the fixing roller, and the control unit that controls the driving of the supply unit. Is a control method of the fixing device that feeds the web from the feeding means every time, the normal temperature and the lower limit temperature of the fixing temperature can be set for each paper type, and the standard setting that feeds the web from the feeding means based on these settings. The feature is that the time and the shortened set time can be set.

According to the ninth aspect of the invention, the normal temperature and the lower limit temperature of the fixing temperature can be set in advance for each paper type,
The standard setting time and the shortening setting time are set based on this setting. In this way, you can set the standard setting time and shortening setting time to send the web according to the paper type used,
The web consumption can be reduced and it is economical.

A tenth aspect of the present invention is a fixing device which executes the control method according to any one of the first to ninth aspects.

According to the tenth aspect of the invention, it is possible to provide a fixing device having the same effects as those of the invention according to any one of the first to ninth aspects.

[0035]

DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a configuration diagram schematically showing a fixing device using a cleaning device according to the present invention. FIG. 2 is a block diagram showing the configuration of the control system of the cleaning device. FIG. 3 is a schematic view of a copying machine using the fixing device of FIG.

The copying machine 1 then feeds a reading section 3 for reading a document image, an image forming section 5 for forming an image, and a transfer material (recording material) P in order from above the copying machine 1. It has a paper feed section 7.

The reading section 3 is provided on the top surface of the cover 9 that covers the surroundings, a contact glass 11 for setting an original image (copy original), and a contact glass 11 that can be opened and closed. A document holder 13 for holding the set copy original, and a photoconductor 17 for reading the copy original set on the contact glass 11
And an optical device (exposure means) 15 for forming an electrostatic latent image.

The image forming section 5 has a photoconductor (image carrier) 17 which rotates in the clockwise direction (see the arrow) in the figure. A charging device (charging means) 19 that uniformly charges the surface of the body 17, a developing device (developing means) 22 that visualizes the electrostatic latent image of the photoconductor 17 as a toner image by the developing sleeve 20, and the photoconductor 1.
Transfer device (transfer means) 24 for transferring the toner image (visible image) of No. 7 onto the transfer material P which is a recording material, and the photoconductor 17 after transfer.
And a photoconductor cleaning device 28 for cleaning the photoconductor 17 by removing the toner remaining on the photoconductor.

Further, at the lower left of the photoconductor cleaning device 28 in the figure, a fixing roller 30 which applies heat and a pressure roller 34 which presses (presses) the transfer material P toward the fixing roller 30, and a fixing roller. A cleaning device 80 for cleaning 30 is provided, and a fixing device 32 for thermally fixing the toner image transferred to the transfer material P is arranged. The transfer material P on which the toner image is fixed by the fixing device 32 is ejected to the ejection tray 45 and stacked.

The paper feeding unit 7 is located at the lower part of the copying machine 1, and has a paper feeding cassette 33 for accommodating the transfer material P and one end side of the paper feeding cassette 33 in the paper feeding direction (upper right side in FIG. 1). ) For feeding the transfer material P in the paper feed cassette 33, and the transfer material P fed by the paper feed roller 35 is conveyed between the photoconductor 17 and the transfer device 24. And a transfer paper transport device 37.

The transfer sheet conveying device 37 includes the sheet feeding roller 3
A transfer paper transport path 40 that is folded back in a substantially U-shape from the right side of FIG. 5 between the photoconductor 17 and the transfer device 24 is formed by a plurality of guide plates 39. In the transfer paper transport path 40,
First intermediate roller pair 41a and second intermediate roller pair 41b
And a registration roller pair 43 are arranged.

As shown in FIG. 1, the fixing device 32 includes a fixing (heating) roller 30 having a heat source inside and a fixing roller 30.
The toner image 53 is fixed to form a fixed image 55 by passing the transfer material P holding the unfixed image (toner image) 53 in the nip portion with the pressure roller 34 that is in pressure contact with.

Further, the cleaning device 8 for the fixing device 32
0 is a web 56 for contacting the fixing roller 30 and cleaning the deposits on the surface of the fixing roller 30 and applying oil for offset prevention (usually, the web 56 is previously impregnated with oil such as silicone oil as an offset prevention measure). And a pressing portion 71 for pressing the web 56 against the fixing roller 30, a winding roller 58 for winding the used web, and a web driving portion such as a motor for driving the winding roller 58. 59, a web control device (control means) 60 for controlling the web drive part 59, a supply roller 61 for holding and feeding the unused web 56, and a temperature detection sensor (temperature detection means) for detecting the temperature of the fixing roller 30. ) 82 and. In the present embodiment, the take-up roller 58, the supply roller 61, and the web drive unit 59 configure a supply unit (supply unit) 81 that sends the web 56 toward the fixing roller 30.

Although there are various control methods for winding the cleaning web 56, basically, the web is intermittently wound little by little at regular intervals, which will be described later. The relationship between the winding direction of the web 56 and the rotation direction of the fixing roller may be either forward or reverse, and in the present embodiment, the web 56 is wound in the reverse direction (counterclockwise direction).

The pressing portion 71 connects the web 56 to the fixing roller 3
It has a pressing roller 71 which is actually pressed against 0 and creates a necessary nip width at its contact portion. The pressing roller 71 has a heat resistant low hardness rubber or a rubber layer surface made of urethane foam or silicon. The pressing portion 71 has a pressing spring 72 that acts on the pressing roller 71 and applies a constant pressing force in the direction of the fixing roller 34.

The reason for using the pressing roller 71 is as follows.
This is to form a nip to some extent as compared with blades, to reduce the service life and the winding load at the time of winding a used web, reduce the load on the fixing roller 30 side due to the contact of the web with the fixing roller 30, and reduce the load. Since the selection of the pressing roller 57 and the pressing spring 72 is an important factor that determines the performance of the cleaning device 81, the diameter of the pressing roller 57, the rubber hardness, the pressing force of the pressing spring 72, etc. are set from the viewpoint of cleaning performance and life. Will be done. Further, other important factors related to the cleaning performance include the surface material of the web 56, the amount of oil, the web feed amount, and the web feed interval.

The web control device 60 has a recording device main body control unit 63, is connected to the jam detection unit 65 via the integration counter (counter means) 64, the web drive unit 59, and the main body control unit 63, and further, The temperature control device 83 for controlling the temperature of the fixing roller 30 and the discharge sensor 62 are connected.

The paper discharge sensor 62 detects the transfer material P discharged from the fixing device 32 toward the paper discharge tray 45, and the integrating counter 64 detects the ON time of the paper discharge sensor 62 (detects the transfer material P). Time). That is, the integration counter 64 integrates the drive time of the fixing roller 30. The integration counter 64 integrates the drive time of the drive unit that drives the fixing roller 30 so that the fixing roller 3
The drive time of 0 may be integrated. The driving time of the fixing roller 30 may be integrated. Further, the jam detection unit 65 determines that the paper is jammed when the paper discharge sensor 62 is ON for a predetermined time or longer.

The temperature control device 83 includes a temperature detection sensor 82.
The temperature of the fixing roller 30 is controlled in accordance with the detection signal from the control roller, and the temperature of the fixing roller 30 is controlled to a predetermined fixing temperature (180 ° C. in the present embodiment) during fixing. Further, the temperature control device 83 is set to a lower limit temperature during fixing (160 ° C. in the present embodiment), and in the present embodiment, the temperature of the fixing roller 30 is equal to or lower than the lower limit temperature. When the temperature detection sensor 82 continuously detects the temperature for a fixed time (5 seconds in the present embodiment) (hereinafter, simply referred to as “lower limit detection”), the cleaning device 80 performs various operations described below. In this embodiment, the fixing temperature is set to 180 ° C. and the lower limit temperature is set to 160 ° C. However, the present invention is not limited to this, and can be appropriately changed according to the specifications of the fixing device 32, the usage environment and the like.

The web controller 60 has a standard set time a.
(60 seconds in this embodiment) is input in advance,
Each time the count value of the integration counter 64 reaches the reference set time a, the web drive unit 59 is driven, whereby the winding roller 58 winds the web 56, and the unused web 5
6 is supplied to the fixing roller 30.

Further, in the present embodiment, when the lower limit is detected, the web drive unit 5 is shorter than the reference set time a.
9 is driven. That is, the web control device 60 has a first reset time b when the web drive unit 59 is driven after the job is finished at the time of lower limit detection (after the driving of the fixing device 32 is finished), and a jam is determined at the time of lower limit detection. Second reset time c for driving the web driving unit 59
And have been entered in advance.

In this embodiment, the first reset time b is 6
0 seconds (reference setting time a) × 0.7 (correction coefficient) = 42 seconds, and the second resetting time c is 60 seconds (reference setting time a) ×
0.5 (correction coefficient) = 30 seconds.

Here, the reference setting time a is corrected by the correction coefficient because the reference setting time a is tested from at least one element selected from the type of the transfer material P, the image type and the use environment. However, even if this reference setting time a is set, the generation of offset toner may differ from the initial estimation due to the difference in the paper quality of the transfer material P, and the required image type, operating environment,
This is because, for example, the initial estimate may differ depending on temperature, humidity, continuous jobs, intermittent jobs, and the like. In such a case, such information is input to the control device 60 in advance and the standard set time a is set based on the information. It's fixed.

The reference set time a and each coefficient are set by empirically or experimentally estimating the relationship between the integrated value and the limit of the stain state during the job operation of the fixing device 32, and the fixing used. It is determined by the specifications and performance of the device 32. Further, each of the above-mentioned coefficients may be a fixed value based on the result of the experiment, but may be appropriately changed as a parameter in order to meet the user's paper type, image type, and usage environment.

Next, the operation of this embodiment will be described based on the above-mentioned configuration. When the copy start button is pressed, image formation by the copying machine 1 starts, and an unfixed toner image 53 is formed on the transfer material P from the paper feeding unit 7. The transfer material P is fixed by the fixing roller 30 and the pressure roller. It is conveyed to and from 34. The fixing device 32 nips and conveys the transfer material P between the fixing roller 30 and the pressure roller 34 (passes the transfer material P between the rollers 30 and 34),
The heat and pressure fix the unfixed toner image 53 on the transfer material P.

Here, when the temperature detecting sensor 82 detects that the temperature of the fixing roller 30 is below the lower limit temperature for 5 seconds, the cleaning device 80 performs the following various operations. First, based on the flowchart of FIG.
Cleaning device 8 after driving of fixing device 32 is completed
The operation of 0 will be described.

When the fixing device 32 is driven, for example,
When the temperature of the fixing roller 30 decreases due to continuous sheet feeding, and the temperature detection sensor 82 detects the lower limit temperature (160 ° C.) for 5 seconds and then the print job ends (steps S1 and S2), the web controller 60. Is the count value of the integration counter 64 and the first set value b (4 in the present embodiment).
2 seconds), and if the count value is less than 42 seconds (step S3), the web drive unit 59 is not controlled.

When the count value is 42 seconds or more (step S4), the web drive unit 59 is instructed to wind the web and the take-up roller 58 promptly takes up the web 56. As a result, the unused web 56 is supplied from the supply roller 61 to the fixing roller 30 (step S
4), the count value of the integration counter 64 is reset to 0 (step S5).

When the temperature of the fixing roller continues to drop while the fixing device 32 is being driven, a large amount of offset toner is likely to be generated, and after the driving of the fixing device 32 is finished,
Although the toner easily slips through, in such a case, the web drive unit 59 is controlled for the first resetting time b which is shorter than the reference setting time a which is a normal control interval.

That is, when a large amount of offset toner is likely to be generated, the web 5 is moved earlier than the standard set time a.
By sending out 6, the offset toner on the fixing roller 30 can be removed, so that the toner can be prevented from passing through the web 56, and the transfer material P due to the toner passing through can be prevented.
It can prevent the stains. Further, since the unused web 56 is not always supplied, the consumption amount of the web 56 can be reduced, which is economical.

Next, based on FIG. 5, the temperature detection sensor 8
2 describes the operation of the cleaning device 80 when a jam occurs in the case where the temperature of the fixing roller 30 is below the lower limit temperature for 5 seconds. In FIGS. 5 and 6, the same parts as those in FIG. 4 are designated by the same reference numerals.

After the temperature detection sensor 82 detects the lower limit temperature for 5 seconds (step S1) and the jam detection unit 65 detects the occurrence of a jam in the fixing device 32 (steps S11 and S12), the web controller 60 is
The count value of the integration counter 64 and the second set value b (30 seconds in the present embodiment) are compared, and when the count value is 30 seconds or more (step S13), steps S4 and S4 in FIG. The same operation as S5 is performed.

When a jam occurs after the temperature of the fixing roller 30 continues to drop while the fixing device 32 is driven, unfixed toner on the transfer material P often adheres to the fixing roller 30. In such a case, the unfixed toner adhering to the fixing roller 30 can be removed by sending out the web 56 earlier than the reference set time a, so that the transfer material P is soiled by the unfixed toner adhering to the fixing roller 30. Can be prevented. In addition, the fixing device 3
Jam where transfer material P has not reached 2 (eg, paper feed failure jam)
In the case of, the operation shown in FIG.
You can save six.

Next, with reference to FIG. 6, the operation of the cleaning device 80 at the time of the returning operation after the jam occurs will be described. After the temperature detection sensor 82 detects the lower limit temperature for 5 seconds (step S1) and the jam detection unit 65 detects the occurrence of a jam in the fixing device 32 (steps S11 and S12), the web control device 60 Integrating counter 6
4 and the second set value b (30 in the present embodiment).
Second) and when the count value is 30 seconds or more (step S13), the same operation as step S4 and step S5 of FIG. 4 is performed.

Then, after the jammed paper is removed by the user, the fixing device 32 performs the returning operation, and the fixing roller 3
When 0 rotates once (step S20), the web drive unit 5
By sending a winding instruction to the sheet 9, the unused web 56 is sent from the supply roller 61 to the fixing roller 30 (step S21).

When removing the jammed paper, the fixing roller 30 is used.
The unfixed image on the jammed paper may be attached to the fixing roller 30, and the unfixed image attached to the fixing roller 30 is dammed by the web 56 while the fixing roller 30 rotates once during the returning operation, and then the take-up roller 30. It is removed from the fixing roller 30 by the winding operation of 58. In this way, since the unfixed image attached to the fixing roller 30 can be removed when removing the jammed paper, it is possible to prevent the transfer material from being soiled by the unfixed image attached to the fixing roller 30 during the jam processing.

Next, another embodiment will be described. In the description, the same parts as those described above are designated by the same reference numerals, and the description thereof will be omitted.

In the second embodiment, the temperature detecting sensor 82 indicates that the temperature of the fixing roller 30 is equal to or lower than the lower limit temperature.
In the case of detecting for one second, it is the first that the control interval for the web driving unit 59 is changed while the fixing device 32 is being driven.
Different from the embodiment. In the second embodiment, the control device 6
A third set time d for driving the web driving unit 59 when the fixing roller 30 is driven when the lower limit is detected is input in advance to 0. In the present embodiment, the third set time d
Is 60 seconds (reference setting time a) × 0.8 (correction coefficient) = 4
8 seconds.

As shown in FIG. 7, when the temperature detection sensor 82 detects the lower limit temperature for 5 seconds (step S1), the web controller 60 sets the interval for driving the web drive unit 59 to the third from the reference set time a. Time d (4 in this embodiment)
8 seconds) and the count value of the integration counter 64 becomes the third
Every time the set time d is reached, the web drive unit 59 is controlled to wind the web 56 (step S30).

When the print job is completed, the control device 60 integrates the count value of the integration counter 64 and the above-mentioned coefficient in the third set time d (48 seconds × 0.7 = 3).
3.6 seconds), and if the count value is 33.6 seconds or more, steps S4 and S5 in FIG.
After performing the control similar to the above, the control interval during driving is returned to the reference set time a (step S33).

If the temperature of the fixing roller continues to decrease while the fixing device 32 is being driven, the offset toner often increases on the fixing roller 30 due to the decrease in the temperature of the fixing roller. , In such cases,
By performing the delivery control earlier than the reference set time a during driving, the offset toner on the fixing roller 30 can be removed before the web can completely process the offset toner. Therefore, the offset toner attached to the fixing roller 30 can be removed. However, it can be prevented from adhering to the transfer material P which is being passed.

Next, a third embodiment will be described with reference to FIG. In this embodiment, the temperature control device 83 is adapted to preset the normal fixing temperature of the fixing roller 30 (for example, 180 ° C. for paper A and 190 ° C. for thick paper J) depending on the type of paper used. Further, the lower limit temperature at the time of fixing (for example, 160 ° C. for the sheet A, 170 ° C. for the thick sheet J) can be set depending on the type of paper used, and the state where the temperature of the fixing roller 30 is below the lower limit temperature is detected. When the sensor 82 continuously detects for a fixed time (5 seconds in the present embodiment) (lower limit detection), the cleaning device 80 performs the following operations.

The web controller 60 has a reference set time a (for example, 60 seconds for paper A,
(Thickness J is 30 seconds) is input in advance, and the web drive unit 59 is driven each time the count value of the integration counter 64 reaches the reference set time a, whereby the winding roller 58 winds the web 56. The unused web 56 is supplied to the fixing roller 30. In addition, the shortened set time when the temperature lower than the lower limit temperature during fixing is detected for a certain period of time can be set in advance for each paper type used. (For example, 30 seconds for the paper A and 15 seconds for the thick paper J) When the web controller 60 drives the web drive unit 59 after the job is completed, the normal fixing temperature or the lower limit is detected. And a fifth resetting time for driving the web drive unit 59 when the paper jam is determined. In this setting, a correction coefficient is provided for each type of paper used. For example, in the case of paper A,
The correction coefficient at the end of the job is 0.7, and the correction coefficient at the time of jam processing is 0.5. At the normal fixing temperature, the fourth reset time at the end of the job is 60 seconds × 0.7 = 42 seconds, and the fifth reset time at the time of jam processing is 60 seconds × 0.5 = 30 seconds. On the other hand, when the lower limit is detected, the fourth
The resetting time is 30 seconds × 0.7 = 21 seconds, and the fifth resetting time during jam processing is 30 seconds × 0.5 = 15 seconds.

Next, based on the flowchart of FIG.
The operation control at the end of the print job when the paper A is set will be described. First, when the sheet A is set and the copy start button is pressed (steps S41 and S42), image formation is started and the transfer material P is conveyed to the fixing device 32. In the fixing device 32, the integration counter 6
The count value of 4 is the reference set time a (6 in this embodiment).
The unused web 56 is supplied to the fixing roller 30 by driving the web drive unit 59 every 0 seconds) (step S43).

When the fixing device 32 is driven, the temperature of the fixing roller 30 is lowered due to, for example, continuous sheet passing, and the temperature detection sensor 82 causes the lower limit temperature (160 ° C. in this embodiment).
Is detected for 5 seconds or more (step S4
4). When the lower limit temperature is detected for 5 seconds or more, the drive interval is shortened, and the web 56 is driven every shortened set time (30 seconds in the present embodiment).

When the lower limit temperature is not detected for 5 seconds or more,
Returning to step S43, the print job ends in step S46 with the reference set time a remaining unchanged. After finishing the print job,
The web control device 60 compares the count value of the integration counter 64 with the fourth reset time (21 seconds in the present embodiment), and if the count value is less than 21 seconds, controls the web drive unit 59. Not performed (step S47).

When the count value is 21 seconds or more, the web drive unit 59 is instructed to wind the web.
By causing the take-up roller 58 to take up the web 56 promptly, the unused web 56 is supplied from the supply roller 61 to the fixing roller 30 (step S48), and the count value of the integration counter 64 is reset to count. The value is set to 0 (step S49).

Next, with reference to the flowchart of FIG. 10, the operation control at the time of jam determination in the case where the sheet A is set will be described. Note that steps S51 to S5
The operation flow up to 5 is the same as steps S41 to S4 in FIG.
Since it is the same as that up to 5, description thereof will be omitted, and step S56
The flow from the time when the jam is determined will be described.

When the jam detector 65 detects the occurrence of a jam in the fixing device 32 (step S56) and the jam detector 65 detects the occurrence of a jam in the fixing device 32 (step S57), the web The control device 60 compares the count value of the integration counter 64 with the fifth resetting time (15 seconds in the present embodiment) (step S58), and when the count value is 15 seconds or more, FIG. The same operation as that of steps S48 and S49 is performed (steps S59 and S60). Also, step S5
7, the transfer material P has not reached the fixing device 32.
In the case of (eg, paper feeding failure jam, etc.), step S59
And the operation shown in step S60 is not performed.

As described above, since the operation interval of the web 56 can be set for each type of paper that the user or the like uses everyday, the wasteful consumption of the web 56 can be prevented. Further, only when the temperature of the fixing roller 30 is lower than or equal to the lower limit temperature corresponding to the paper for a certain period of time, the operation of the web 56 is performed at the end of the print job or when the paper jam is determined. Since the interval is set differently for each sheet, wasteful consumption of the web 56 and toner slippage can be effectively prevented.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the invention.

For example, in the first embodiment, the fixing device 32
After the end of the driving of the fixing device 32, the control interval for the web driving portion 59 of the fixing device 32 is set, but the invention is not limited to this. For example, the control interval may be changed only after the end of the driving of the fixing device 32. Alternatively, the winding time of the web 56 may be determined according to the consumption amount of the web 56, the offset state, and the like. Further, in the third embodiment, the normal temperature and the lower limit temperature of the fixing temperature can be set in advance for each paper type, and the standard set time a and the shortened set time can be set based on these settings. The operation is not limited to that described above.

Although the present invention is applied to the fixing device 32 of the copying machine 1, the present invention is not limited to this, and in addition to the copying machine, a printer,
Similar effects can be obtained even when applied to a fixing device of an image forming apparatus such as a facsimile or a complex machine of these.

[0084]

According to the first aspect of the present invention, when the temperature of the fixing roller continues to decrease and the offset toner tends to increase, the control means causes the web to be sent out earlier than the reference set time. This prevents the increase of offset toner that the web is damming, and
Since the toner can be prevented from slipping through, the transfer material can be prevented from being contaminated due to the toner slipping through. Moreover, since the unused web is not always sent out, the consumption of the web can be reduced, which is economical.

According to the second aspect of the present invention, the same effect as that of the first aspect of the present invention is obtained, and the reference setting is performed after the end of driving the fixing device in which a slight deviation easily occurs between the web and the fixing roller. Since the web is sent out earlier than the time, it is possible to further prevent the transfer material from being contaminated due to the toner slipping through.

According to the third aspect of the present invention, the same effect as that of the first or second aspect of the present invention can be obtained, and the control means sets a reference when a jam occurs in which unfixed toner often adheres to the fixing roller. By feeding the web earlier than the set time, the unfixed toner on the fixing roller can be removed by the web, so that the transfer material can be prevented from being soiled by the unfixed toner adhering to the fixing roller.

According to the invention described in claim 4, the same effect as the invention described in claim 1 or 2 is obtained, and unfixed toner often adheres to the fixing roller at the end of the print job. In this case, the control unit can remove the unfixed toner on the fixing roller by the web by feeding the web earlier than the reference set time, so that the transfer material is prevented from being soiled by the unfixed toner adhering to the fixing roller. it can.

According to the fifth aspect of the invention, the same effect as that of the third aspect of the invention is obtained, and the unfixed toner attached to the fixing roller when removing the jammed paper is removed by the web. It is possible to prevent the transfer material from being soiled by the unfixed toner attached to the fixing roller during the jam processing.

The invention according to claim 6 has the same effect as the invention according to any one of claims 1 to 4, and since the resetting time can be set for each paper type, when a jam occurs or a print job is performed. At the end, the web can be effectively driven according to the paper type, and thus the consumption of the web can be reduced.

In the invention described in claim 7, the same effect as the invention described in any one of claims 1 to 6 is obtained, and the temperature detecting means keeps the temperature below a predetermined value during the driving of the fixing device. If it is detected continuously over time, the offset toner is often increasing due to the temperature drop on the fixing roller.In such a case, the web is sent earlier than the standard set time, so It is possible to prevent the adhered offset toner from adhering to the transfer material being passed.

According to the invention described in claim 8, the same effect as that of the invention described in claim 6 is obtained, and the normal temperature and the lower limit temperature of the fixing temperature can be set in advance for each paper type, and the standard is set based on this setting. Set the set time and shortened set time. In this way, the standard setting time and the shortening setting time for sending out the web can be set according to the type of paper used, so that the consumption of the web can be reduced and it is economical.

According to the ninth aspect of the invention, since the standard setting time and the shortening setting time for sending the web can be set according to the type of paper used, the consumption of the web can be reduced and it is economical.

According to the tenth aspect of the invention, it is possible to provide a fixing device having the same effects as those of the invention according to any one of the first to ninth aspects.

[Brief description of drawings]

FIG. 1 is a configuration diagram schematically showing a fixing device in which a cleaning device according to the present invention is used.

FIG. 2 is a configuration diagram schematically showing a copying machine using the fixing device shown in FIG.

FIG. 3 is a diagram showing a configuration of a control system in the fixing device.

FIG. 4 is a flowchart showing an operation of the fixing device according to the first exemplary embodiment.

FIG. 5 is a flowchart showing the operation of the fixing device according to the first embodiment.

FIG. 6 is a flowchart showing an operation of the fixing device according to the first exemplary embodiment.

FIG. 7 is a flowchart showing an operation of the fixing device according to the second embodiment.

FIG. 8 is a diagram showing a set time for each sheet according to the third embodiment.

FIG. 9 is a flowchart showing an operation of the fixing device according to the third embodiment.

FIG. 10 is a flowchart showing an operation of the fixing device according to the third embodiment.

[Explanation of symbols]

30 fixing roller 32 fixing device 34 Pressure roller 53 Unfixed toner image 56 web 57 Pressing part (pressing means) 58 winding roller 59 Drive means 60 Web control device (control means) 64 integrating counter (counting means) 80 cleaning device 81 Supply Unit (Supply Means)

Claims (10)

[Claims] 1. A web supply means for performing at least one of cleaning the peripheral surface of a fixing roller and applying oil, and
A pressing unit that presses the web toward the peripheral surface of the fixing roller, a temperature detecting unit that detects the temperature of the fixing roller, a counting unit that integrates the driving time of the fixing roller, and a control unit that controls the driving of the supply unit. A method of controlling a fixing device that feeds a web from a supply device each time the integrated value of the counting device reaches a preset reference set time, wherein the temperature detection device is below a predetermined value while the fixing device is being driven. A method for controlling a fixing device, wherein when the temperature is continuously detected for a certain period of time, the control unit feeds the web from the supply unit in a resetting time shorter than the reference setting time. 2. When the temperature detecting means continuously detects a temperature equal to or lower than a predetermined value for a certain time during driving of the fixing device, and when the driving of the fixing device is finished, the count value of the counting means is reset time. The control method of the fixing device according to claim 1, wherein when the above is the case, the control means sends out the web from the supply means. 3. The count value of the counting means is equal to or longer than the reset time when a jam occurs when the temperature detecting means continuously detects a temperature equal to or lower than a predetermined value for a predetermined time during driving of the fixing device. The control method for the fixing device according to claim 1 or 2, wherein the web is sent out from the supply means. 4. When the temperature detecting means continuously detects a temperature equal to or lower than a predetermined value for a fixed time during driving of the fixing device, and when the count value of the counting means is equal to or more than the reset time at the end of the print job. The method for controlling the fixing device according to claim 1 or 2, wherein the web is sent from the supply means. 5. The method of controlling the fixing device according to claim 3, wherein the web is fed from the supply means after the fixing roller has rotated once during the returning operation of the fixing device after removing the jammed paper. . 6. The method of controlling a fixing device according to claim 1, wherein the resetting time can be set for each paper type. 7. When the temperature detecting means continuously detects a temperature below a predetermined value for a certain period of time before a print job or a jam occurs, the supplying means outputs the shortened set time which is equal to or longer than the reset time and equal to or shorter than the reference set time. 7. The fixing device control method according to claim 1, wherein the web is sent out. 8. The normal temperature and the lower limit temperature of the fixing temperature can be set for each paper type, and the standard setting time and the shortening setting time for feeding the web from the supply means can be set based on these settings. The method for controlling the fixing device according to item 1. 9. A web supply means for performing at least one of cleaning the peripheral surface of the fixing roller and applying oil,
A pressing unit that presses the web toward the peripheral surface of the fixing roller, a temperature detecting unit that detects the temperature of the fixing roller, a counting unit that integrates the driving time of the fixing roller, and a control unit that controls the driving of the supply unit. And a control method of the fixing device that feeds the web from the feeding means each time the integrated value of the counting means reaches a preset reference set time,
A fixing device control method, wherein a normal temperature and a lower limit temperature of a fixing temperature can be set for each paper type, and a standard setting time and a shortening setting time for feeding a web from a supply unit can be set based on these settings. 10. A fixing device which executes the control method according to claim 1. Description: