JPH0467083A - image forming device - Google Patents

Abstract

PURPOSE:To prevent soiling when an image is formed after the processing of jamming from occurring and to prolong the life of a cleaning means or a fixing roller with respect to the soiling by rotating the fixing roller as long as a prescribed time and making the cleaning means abut on the fixing roller when abnormality is removed when a power source is turned on again after it is shut off because of the detection of the abnormality. CONSTITUTION:When the jamming of a paper occurs by some cause and it is detected, the power source is interrupted to be supplied to respective equipments. When the power source is turned on again after the abnormality is removed, the upper roller 16A of a fixing device 16 is rotated and a solenoid is driven after the roller 16A is started to be rotated. Besides, a cleaning pad 17 abuts on the roller 16A. Then, the rotation of the roller 16A is stopped after the lapse of prescribed time and the solenoid is driven again at the same time. Besides, the pad 17 is detached from the roller 16A. Thus, unfixed developer attached on the fixing roller is eliminated by the cleaning means and contamination by the unfixed developer after the processing of the jamming is surely prevented from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an image forming apparatus that employs electrostatic transfer in one image forming process.

(Prior Art) In such an image forming apparatus, if an abnormality such as a paper jam occurs during the execution of the image forming process, if the image forming process is continued, the photosensitive tram, which is the image carrier, and other parts may be damaged. There are cases where it is damaged or damaged.

Therefore, in conventional image forming apparatuses, an abnormality detection means such as a jam sensor is provided in each part of the paper conveyance path, and when this abnormality detection means detects an abnormality, the power supply to each device is cut off, thereby preventing the problem. was prevented from occurring.

(Problem to be Solved by the Invention) However, in the above-mentioned conventional image forming apparatus, if the abnormality detection means detects an abnormality and the power supply to each device is cut off, the unfixed paper or the fuser At this time, if you pull the paper out to the paper ejection section and clear the jam, unfixed toner on the paper or attached to the fixing roller may be removed, and when you restart the device, the toner attached to the fixing roller This may cause problems such as it getting on the paper that is sent next and staining it.

Therefore, is it possible to consider installing a cleaner member in the fuser that always comes into contact with the fixing roller? According to this, since the cleaner member is always in contact with the fixing roller, the cleaner member gets dirty in a short time. A problem arises. or,
If dust including paper powder accumulates between the cleaner member and the fixing roller, a problem arises in that the dust may damage the surface of the fixing roller.

The present invention has been made in view of the above problems, and its purpose is to prevent stains during image formation after jam removal, and to extend the lifespan of cleaning means and fixing rollers against stains. An object of the present invention is to provide a forming device.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides abnormality detection means in each part of the paper conveyance path, and cuts off the power supply to each device when the abnormality detection means detects an abnormality. In an image forming apparatus having a control means, after an abnormality is detected and the power supply to each device is cut off, when the power is turned on again and it is detected that the abnormality has been cleared, the fixing roller is operated for a predetermined period of time. The fixing roller is rotated by the fixing roller, and the cleaning means is brought into contact with the fixing roller.

(Function) According to the present invention, the power supply to each device is cut off when the paper is caught between the fixing rollers, and the unfixed developer on the paper is removed from the fixing roller because the paper is pulled out to the paper ejection side. Even if the unfixed developer adheres to the fixing roller, when the abnormality is cleared and the power is turned on again, the fixing roller is rotated for a predetermined time and the cleaning means comes into contact with the fixing roller, so the unfixed developer attached to the fixing roller is removed. It is removed by the cleaning means, and contamination caused by unfixed developer after jam processing is reliably prevented.

Further, since the cleaning means is brought into contact with the fixing roller for a predetermined period of time and is separated from the fixing roller for the rest of the time, the life of the cleaning means and the fixing roller against dirt is extended.

(Example) Embodiments of the present invention will be described below based on the accompanying drawings.

FIG. 1 is a sectional view of an image forming apparatus according to the present invention, and FIG. 2 is a detailed view of a fixing device.

First, the general structure of the image forming apparatus according to the present invention will be explained based on FIG. 1.A document is placed on the top surface of the main body 1 of the image forming apparatus. 1 document table 3 is provided, and the same body l
A photosensitive tram 3, which is an image carrier, is disposed approximately in the middle of the frame and is driven to rotate in the direction of the arrow in the figure. Further, above the photosensitive tram 3 in the main body 1, there are mirrors 4, 5, 6, 7 for forming an electrostatic latent image by focusing the original image on the photosensitive tram 3.
and an imaging lens 8 are arranged around the photosensitive tram 3.
A primary charger 9 for uniformly charging the photosensitive tram 3 before image formation, a developer 10 for visualizing the electrostatic latent image formed on the photosensitive tram 3 as a toner image, and a toner image formed on the photosensitive tram 3. A transfer charger 11 that transfers the toner onto the paper, and a cleaner 12 that collects and removes the toner remaining on the photosensitive drum 3 after the transfer are disposed.

Further, a cassette 13 containing a plurality of sheets P is inserted into the lower part of the main body 1, and the cassette 1 in the main body l is inserted.
On the back side of 3 (on the waterworks extension line) is the paper feed roller 14. A registration roller 15 and a fixing device 16 are provided, and a cleaning pad 17 impregnated with silicone oil is provided near the fixing device 16.

The details of the fixing device 16 are shown in FIG. 2. The fixing device 16 is composed of an upper roller 16A and a lower roller 16B that touch each other and rotate in the direction of the arrow in the figure. The toner image is thermally fixed by passing between the -L roller 16A and the lower roller 16B.

Incidentally, the cleaning bat 17 is moved in the direction of the arrow in FIG. 2 by a solenoid (SQL) not shown, and comes into contact with and leaves the upper roller 16A.

If a paper jam occurs for some reason during the image forming process and is detected by a jam sensor (not shown), the power supply to each device is cut off. In this state, jam clearance is performed, the jammed paper P is removed, and when the power is turned on again after the abnormality is cleared, the upper roller 16A of the fixing device 16 is rotated, and after the upper roller 16A starts rotating, the solenoid is activated. The cleaning bat 17 is driven to come into contact with the upper roller 16A as shown by the broken line in FIG. Then, after a predetermined period of time has elapsed, the rotation of the seventh roller 16A is stopped, and at the same time the solenoid is driven again to move the cleaning vat 17 to the upper roller 16A as shown by the solid line in FIG.
move away from

With the above configuration, the paper P is stopped while being sandwiched between the upper and lower rollers 16A and 16B of the fixing device 16, and the paper P is pulled out to the paper ejection side when clearing a jam. Even if the unfixed toner on the top is attached to the upper roller 16A, the attached unfixed toner is removed from the upper roller 16A.
Since the toner is removed by the cleaning bat 17 that comes into contact with A, unfixed toner does not adhere to the paper P that is next sent to the fixing device 16, and the paper P is reliably prevented from becoming dirty.

Further, since the cleaning vat 17 is brought into contact with the upper roller 16A for a predetermined period of time after the jam is cleared, the life of the cleaning vat 17 and the upper and lower rollers 16A and 16B against dirt can be extended.

However, in the embodiments described above, the cleaning bat 17 is configured to come into contact with the upper roller 16A after the upper roller 16A starts rotating, or the cleaning bat 17 is brought into contact with the upper roller 16A by a release signal from the jam sensor when the power is turned on after clearing the jam. may be brought into contact with the upper roller 16A, and then the rotation of the upper roller 16A is started to remove unfixed toner adhering to the upper roller 16A.

Also, the rotation time of the -E roller 16A after an abnormality is detected by the jam sensor is the same as that of the upper roller 1 when the power is normally turned on.
Of course, if the pre-rotation time is set longer than the pre-rotation time of 6A, a higher effect can be obtained than whether the unfixed roller is removed or not.

Incidentally, as a cleaning means for the upper roller 16A, a cleaning roller 18 shown in FIG. 3 may be used instead of the cleaning bat 17.

This cleaning roller 18 is operated by a solenoid (not shown).
OL) in the direction of the arrow in Fig. 3, and the upper roller 1
The cleaning roller 18 comes into contact with and leaves the upper roller 16A, and the types of cleaning roller 18 include one that follows the upper roller 16A, one that rotates in the opposite direction to the rotation direction of the upper roller 16A upon receiving driving force, and one that rotates in the opposite direction to the rotation direction of the upper roller 16A. It is conceivable that a peripheral speed difference is given between the roller 16A and the roller 16A to rotate in the forward direction.

(Effects of the Invention) As is clear from the above description, according to the present invention, an abnormality detection means is provided at each part of the paper conveyance path, and when the abnormality detection means detects an abnormality, control is performed to cut off the power supply to each device. In an image forming apparatus having a method, when an abnormality is detected and the power supply to each device is cut off, when the power is turned on again and it is detected that the abnormality has been cleared, the fixing roller is turned on for a predetermined period of time. Since it is configured so that the cleaning means is brought into contact with the three-stop fixing roller while rotating, it is possible to obtain the effect of prolonging the life of the cleaning means and the fixing roller against stains during image formation after jam removal. .

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the image forming bag according to the present invention, FIG. 2 is a detailed view of the fixing device, and FIG. 3 is a detailed view of the fixing device showing a modified embodiment of the present invention. 16...Fixing device, 16A, 16B-...Upper and lower rollers (fixing roller), 17...Cleaning pad (cleaning means), 18...Cleaning roller (cleaning means). Patent applicant Canon Co., Ltd.

Claims (4)

[Claims] (1) In an image forming apparatus that includes an abnormality detection means in each part of the paper conveyance path and a control means that cuts off the power supply to each device when the abnormality detection means detects an abnormality, each device After the power supply is cut off, when the power is turned on again and it is detected that the abnormality has been resolved,
An image forming apparatus characterized in that the fixing roller is rotated for a predetermined period of time and a cleaning means is brought into contact with the fixing roller. (2) The fixing roller starts rotating after the cleaning means comes into contact with the fixing roller, and the cleaning means is separated from the fixing roller after the rotation of the fixing roller is stopped. image forming device. (3) The cleaning device is configured such that the cleaning device is brought into contact with the fixing roller after the fixing roller starts rotating, and the cleaning device is separated from the fixing roller after the fixing roller stops rotating. Image forming device. (4) The image forming apparatus according to claim 1, wherein the rotation time of the fixing roller after the abnormality is detected is set longer than the previous rotation time of the fixing roller when the power is normally turned on.