JPH1020593A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an unfixed toner image formed on a paper from being offset to a resist roller and to prevent the following paper from being damaged or defectively carried when the jamming of the paper simultaneously caught by the resist roller and a fixing roller is eliminated. SOLUTION: A slit 32 is formed on the upper guide 26b of a guide unit 26 guiding the paper P to a transfer charger 17a from the resist roller pair 24. Then, the paper P is cut by a cutter slid along the slit 32 when the paper jamming is caused. Besides, the part of the paper P caught by the roller pair 24 is pulled out to the paper supply side of the roller pair 24. On the ther hand, the part of the paper P which is caught by the fixing roller 27a and on which the unfixed toner image is formed is pulled out to the side of a carrying path 28 opened by turning the upper unit of a device main body 10. Then, toner is prevented from being attached to the roller pair 24.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an image forming apparatus for easily removing a paper jam of a sheet having an unfixed toner image.

[0002]

2. Description of the Related Art When a paper jam occurs in a paper transporting path in an electrophotographic apparatus or the like, conventionally, an upper unit supporting a photosensitive drum, a developing device, a cleaning device, and the like is placed above the paper transporting path. Rotate to open the transport path and remove the paper on the opened transport path, pull it out to the discharge side of the fixing roller, or pull out the paper to the paper feed side of the registration roller to remove it And so on. If the paper is bitten by the registration roller and also by the fixing roller, it is difficult to pull out the fixing roller with strong pressing force to the paper discharge side. The paper was pulled out to remove the paper jam.

[0003]

However, when the paper bitten by both the registration roller and the fixing roller is pulled out to the paper supply side, an unfixed toner image is formed on the paper, and the toner is transferred to the registration roller when the paper is pulled out. Adheres, the registration rollers become dirty, and during subsequent paper transport,
There has been a problem that the paper is soiled or a new paper jam occurs due to the attached toner.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above-mentioned problem, and in the case where a paper jam occurs in a state in which a sheet is engaged with a registration roller and a fixing roller during image formation, the paper jam is removed without soiling the registration roller. It is an object of the present invention to provide an image forming apparatus capable of preventing a subsequent sheet from being soiled or poorly transported, and capable of obtaining a high-quality image without impairing operability.

[0005]

According to the present invention, as a means for solving the above-mentioned problems, a registration roller means for temporarily stopping a sheet, aligning the leading edges thereof, and then nipping and conveying the sheet in a predetermined direction, and a sheet conveyed by the registration roller means. Image forming means for forming a developer image on the sheet, fixing means for pressing and holding the sheet on which the developer image has been formed by the image forming means, and the image forming means reaching the image forming means from the registration roller means. And a cutting means for cutting the sheet simultaneously held between the registration roller means and the fixing means.

According to another aspect of the present invention, there is provided a registration roller for temporarily stopping a sheet, aligning the leading edge thereof, and nipping and conveying the sheet in a predetermined direction; an image carrier on which a developer image is formed; Transfer means for transferring the developer image formed on the image carrier to the paper conveyed by the registration roller means; guide means for guiding the paper from the registration roller means to the transfer means; and the transfer means Fixing means for pressing and holding the sheet onto which the developer image has been transferred, a slit formed in the guide means so as to be perpendicular to the predetermined direction, and simultaneously holding the resist roller means and the fixing means. And a cutter that slides in the slit and cuts the sheet when the sheet is jammed in the pressed state.

According to another aspect of the present invention, there is provided an apparatus main body having image forming means for forming a developer image on a sheet, the apparatus main body being capable of opening and closing the sheet conveying path at the position of the image forming means. Resist roller means for temporarily stopping the paper in the apparatus main body, aligning the leading edge thereof, and nipping and conveying the paper in the direction of the image forming means; and guide means for guiding the paper from the resist roller means to the image forming means. ,
Fixing means for pressing and holding the sheet on which the developer image has been formed by the image forming means, and a slit formed in the guide means so as to be perpendicular to the direction of the image forming means;
When a paper jam occurs in a state in which a cutter fitted to the slit is attached to the end of a shaft having a length substantially equal to the maximum width of the paper, and the cutter is simultaneously held by the registration roller means and the fixing means. Cutting means for opening the front cover of the apparatus main body, pulling the shaft out of the apparatus main body, sliding the cutter in the slit and cutting the paper, and after the separation, The sheet that has been opened and cut is taken out in the direction of the registration roller unit and in the direction of the fixing unit.

With the above arrangement, the present invention cuts an unfixed toner image forming portion and removes an unfixed toner image even when a paper jam occurs while both the registration roller means and the fixing means are engaged. By pulling out only those parts that do not have to the paper feed side of the registration roller, the toner does not adhere to the unfixed registration roller, preventing the contamination of the paper or the conveyance failure caused by the contamination of the registration roller,
The purpose is to improve image quality and operability.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments shown in FIGS. FIG. 1 is a schematic explanatory view of the entire apparatus. Around a photosensitive drum 12 provided substantially at the center of the apparatus main body 10, an exposure position by a charging device 13, an LED erasing array 15, and an exposure device 14 constituting the image forming means 2 14a, developing device 16, transfer charger 17
a, a peeling charger 17b, a cleaning device 18, and a static elimination lamp 20 are provided. A manual guide 21a is provided on the right side of the apparatus main body 10, and first and second sheet cassette apparatuses 21b and 21c for storing sheet paper P are provided below the apparatus main body 10.

A manual guide 21a is provided in the apparatus body 10.
Or is taken out of the first or second paper feed cassette device 21b, 21c by the first or second pickup roller 22b, 22c and separated by the first or second separation roller 23b, 23c. The pair of registration rollers 24
The sheet P, which has been stopped once and the leading edge thereof has been aligned, is fed again, is guided to the photosensitive drum 12 by the guide unit 26, and is further guided to the fixing unit 27 on the left side of the apparatus main body 10. A passage 28 is formed. This transport path 2
8, a fixing unit 27 having a pair of fixing rollers 27a for nipping, heating and pressing and fixing the sheet P having a toner image, and conveying the sheet P having a toner image, and a pair of sheet discharge rollers 30.
And a paper discharge tray 31.

The apparatus main body 10 is configured so as to be separable into an upper unit 10a and a lower unit 10b with a transport path 28 as a boundary, and the upper unit 10a includes a charging device 13, an exposure device 14, Developing device 16,
It has a cleaning device 18 and a static elimination lamp 20, and the front side can be opened and closed with the rear side of the apparatus main body 10 as a fulcrum. 10c is a front cover.

Next, the guide unit 26 will be described in detail. The guide unit 26 supports the paper P, pre-charges the paper before the transfer by the transfer charger 17a, and regulates the upper part of the paper P supported and transported by the transfer guide 26a, and moves the lower part of the developing device 16 downward. The developing device 1
6 is composed of an upper guide 26b for reducing the airflow below and preventing toner scattering. The upper guide 26b is provided with a slit 32 formed in a direction perpendicular to the direction in which the paper P is conveyed, and a slider 3 slidably fitted in the slit 32.
A cutter 33 as cutting means supported by 3a and a cutting means 36 comprising a shaft 34 for sliding the slider 33a are provided.

The slit 32 is provided so that the cutter 33 is always located outside the transport path 28 which does not hinder the transport of the paper P.
The sheet P is formed to be longer than the maximum width of the sheet P by the length of the slider 33a toward the rear side. Shaft 34 is cutter 3
In a state where 3 is stored on the rear side of the slit 32,
The tab end 34a is formed to be slightly longer than the maximum width of the sheet so that the tab end 34a extends to the front side of the apparatus main body 10.

Reference numeral 37 denotes a first switch for detecting the passage of the sheet P through the pair of registration rollers 26; 38, a second switch for detecting the passage of the sheet through the pair of fixing rollers 28a; 40, a document table; It is a cover.

Next, the operation will be described. At the start of copying, the operator places the document D on the document table 40, sets image forming conditions such as paper size, copy magnification, and number of copies from an operation panel (not shown), and turns on the copy key. Then, the copy operation is started.

As a result, a copy operation is started in the apparatus main body 10, and the photosensitive drum 12 forms a toner image via the charging device 13, the exposure position 14a and the developing device 16 according to the rotation thereof, and the transfer charger 17a Reach
On the other hand, in synchronization with this, the manual feed guide 21a or the first
Alternatively, the paper P is fed from the second paper feed cassette devices 21b and 21c, and sent to the transfer charger 17a via the registration roller pair 26 at the timing when the leading edge of the paper P is aligned with the toner image on the photosensitive drum 12. After the toner image is transferred, the sheet P separated from the photosensitive drum 12 by the separation charger 17b is fixed by the pair of fixing rollers 27a, and is discharged onto the discharge tray 31 by the pair of discharge rollers 30. The copy ends.

On the other hand, after the transfer is completed, the photosensitive drum 12
The residual toner is removed by the cleaning device 18 and the next copy-enabled state is established via the neutralizing lamp 20, and the necessary number of copy operations are repeated.

If a paper jam occurs in the conveyance path 28 during the copying operation, the operator opens the front cover 10c of the apparatus main body 10, and then moves the upper unit 10a to the arrow s. In this direction, the transport path 28 is opened from the front side, and the paper P is removed. At this time, the first switch 37 and the second switch 38 are turned on,
The paper P is a pair of registration rollers 26 and a pair of fixing rollers 27a.
Is detected, the cutting of the paper P is displayed on a control panel (not shown) on the upper surface of the apparatus main body 10.

Therefore, the operator recognizes the display, first opens the front cover 10c, pulls the knob end 34a of the shaft 34 to the front side, slides the cutter 33 along the slit 32 in the direction of arrow t, and moves the registration roller pair. The sheet P is cut between the transfer sheet 26 and the transfer charger 17a. Then, the portion of the sheet P caught by the pair of registration rollers 26 is pulled out toward the sheet feeding side, and the upper unit 10 a
Is rotated in the direction of the arrow s, and the portion caught by the fixing roller pair 27a is pulled out from the opened conveyance path 28 side to remove a paper jam.

Thereafter, the upper unit 10a is closed, the shaft 34 is returned to the inside of the apparatus main body 10, the cutter 33 is placed in the rear side of the slit 32, and then the front cover 10c is closed to complete the operation for removing the paper jam. Make it copyable.

With this configuration, even if a sheet jams while the sheet is engaged with the registration roller pair 26 and the fixing roller pair 27a during image formation, the transfer charger 17
a, the sheet P is cut off before a, and only the portion having no unfixed toner image is pulled out and removed to the sheet feeding side of the registration roller pair 26, while the portion having the unfixed toner image bitten by the fixing roller 27a is opened. Since it is pulled out and removed to the conveyance path 28 side, even if the portion caught by the registration roller pair 26 is pulled out to the paper supply side, the registration roller pair 26 is not likely to be stained by unfixed toner. This can prevent the paper from being stained or jammed due to the contamination of the paper, improve the image quality, improve the reliability at the time of transporting the paper, and improve the operability by reducing the paper jam removing operation.

The present invention is not limited to the above-described embodiment, and can be changed without departing from the spirit of the present invention. For example, the upper unit may be opened from the side instead of the front side. The means may be of any structure as long as it does not hinder the conveyance of the sheet during image formation. For example, a rail may be provided on the guide means, and the cutter may be slid along the rail.

[0023]

As described above, according to the present invention, even if a paper jam occurs while being engaged with the registration roller means and the fixing roller means, the paper is cut off in front of the image forming means. It is possible to prevent the unfixed toner from adhering to the registration roller means at the time of removal, and it is possible to improve image quality and operability without causing image contamination due to offset of the toner from the registration roller means or conveyance failure by the registration roller means. .

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing an apparatus main body according to an embodiment of the present invention.

FIG. 2 is a schematic explanatory view showing a transfer guide unit according to the embodiment of the present invention.

FIG. 3 is a schematic perspective view showing a cutting means according to the embodiment of the present invention.

FIG. 4 is a schematic perspective view showing a cutter and a shaft according to the embodiment of the present invention.

FIG. 5 is a schematic perspective view of the apparatus main body according to the embodiment of the present invention when the conveyance path is opened, as viewed from the side.

FIG. 6 is a schematic perspective view of the apparatus body according to the embodiment of the present invention when the apparatus body is transported and opened, as viewed from the front side.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Device main body 10a ... Upper unit 10b ... Lower unit 10c ... Front cover 12 ... Photoconductor drum 17a ... Transfer charger 24 ... Registration roller pair 26 ... Guide unit 26b ... Upper guide 27a ... Fixing roller 32 ... Slit 33 ... Cutter 33a ... Slider 34 Shaft 36 Cutting means 37 First switch 38 Second switch

Claims (9)

[Claims] An image forming means for forming a developer image on the sheet conveyed by the resist roller means; Fixing means for pressing and holding the sheet on which the developer image is formed by the image forming means,
An image forming apparatus provided with a cutting unit provided between the registration roller unit and the image forming unit to cut the sheet simultaneously held by the registration roller unit and the fixing unit; . 2. A registration roller means for temporarily stopping a sheet, aligning the leading edge thereof, and nipping and conveying the sheet in a predetermined direction; an image carrier on which a developer image is formed; Transfer means for transferring the developer image formed on the image carrier, fixing means for pressing and holding the paper on which the developer image has been transferred by the transfer means, and transfer means from the registration roller means to the transfer means An image forming apparatus, comprising: a cutting unit that is provided until the sheet reaches the cutting unit and cuts the sheet that is simultaneously held by the registration roller unit and the fixing unit. 3. A registration roller means for temporarily stopping the paper, aligning the leading edge thereof, and nipping and transporting the paper in a predetermined direction; an image carrier on which a developer image is formed; Transfer means for transferring the developer image formed on the image carrier, fixing means for pressing and holding the paper on which the developer image has been transferred by the transfer means, and transfer means from the registration roller means to the transfer means An image forming apparatus comprising: a cutter provided until the image forming apparatus reaches the position. 4. The image forming apparatus according to claim 3, wherein the cutter slides at a right angle to a predetermined direction, and cuts the sheet held at the same time by the registration roller means and the fixing means. 5. A registration roller means for temporarily stopping the sheet, aligning the leading edge thereof, and nipping and conveying the sheet in a predetermined direction; an image carrier on which a developer image is formed; Transfer means for transferring the developer image formed on the image carrier, guide means for guiding the sheet from the registration roller means to the transfer means,
Fixing means for pressing and holding the sheet on which the developer image has been transferred by the transfer means, a slit formed in the guide means so as to be perpendicular to the predetermined direction, the registration roller means and the fixing means; An image forming apparatus comprising: a cutter that slides in the slit and cuts the sheet when a sheet jam occurs in the state where the sheet is simultaneously clamped. 6. An apparatus main body having an image carrier on which a developer image is formed, and a registration roller means for temporarily stopping the paper in the apparatus main body, aligning the leading ends thereof, and nipping and conveying the sheet in the image carrier direction. Transfer means for transferring the developer image formed on the image carrier to the sheet provided by the registration roller means and opposed to the image carrier;
Guide means for guiding the sheet from the registration roller means to the transfer means; fixing means for pressing and holding the sheet on which the developer image has been transferred by the transfer means; and A slit formed to be a right angle, and a cutter fitted to the slit is attached to a tip of a shaft having substantially the same length as the maximum width of the paper,
When the paper jam occurs in the state where the paper is held by the registration roller means and the fixing means at the same time, the front cover of the apparatus main body is opened, the shaft is pulled out of the apparatus main body, and the cutter is pulled out. Means for sliding in the slit to cut the sheet. 7. An apparatus body having an image forming means for forming a developer image on a sheet and capable of opening and closing the sheet transport path at the position of the image forming means, and temporarily stopping the sheet in the apparatus body. After the leading edge is aligned, a registration roller means for nipping and transporting in the direction of the image forming means, a guide means for guiding the sheet from the registration roller means to the image forming means, and a developer image is formed by the image forming means. A fixing means for pressing and holding the sheet, a slit formed in the guide means so as to be perpendicular to the direction of the image forming means, and a slit fitted to the tip of a shaft having a length substantially equal to the maximum width of the sheet. When a paper jam occurs in a state in which a cutter is attached and the paper is caught by the registration roller means and the fixing means at the same time, the front cover of the apparatus body is opened. Means for pulling the shaft out of the apparatus main body, sliding the cutter in the slit and cutting the sheet, opening the transport path after separation, and cutting the cut sheet, An image forming apparatus which takes out the toner in a direction before the registration roller means and in a direction before the fixing means. 8. An apparatus body for supporting an image carrier on which a developer image is formed by an openable and closable upper unit, and the image carrier after temporarily stopping the paper and aligning the leading edge in the apparatus body. Registration roller means for nipping and transporting the developer in a direction, transfer means for transferring the developer image formed on the image carrier to the sheet provided opposite to the image carrier and transported by the registration roller means, Guide means for guiding the sheet from the registration roller means to the transfer means, fixing means for pressing and holding the sheet on which the developer image has been transferred by the transfer means, and perpendicular to the image carrier direction to the guide means And a cutter that fits into the slit is attached to a tip of a shaft having a length substantially equal to the maximum width of the paper, and the registration roller unit and the fixing unit When the paper jam occurs in the state where the paper is clamped at the same time, the front cover of the apparatus main body is opened, the shaft is pulled out of the apparatus main body, and the cutter is slid in the slit to slide the paper. An image forming apparatus comprising: a cutting unit that cuts the sheet; and after cutting, the upper unit is opened, and the cut sheet is taken out toward the registration roller unit and the fixing unit. 9. An apparatus main body for supporting an image carrier on which a developer image is formed by an openable and closable upper unit, and the image carrier after temporarily stopping the paper in the apparatus main body and aligning the leading ends thereof. Registration roller means for nipping and conveying in the direction, first detection means provided near the registration roller means for detecting the presence or absence of the sheet, and said registration roller means provided opposite to the image carrier and conveyed by the registration roller means. Transfer means for transferring the developer image formed on the image carrier to paper, guide means for guiding the paper from the registration roller means to the transfer means, and the developer image transferred by the transfer means Fixing means for pressing and holding the sheet; second detecting means provided near the fixing means for detecting the presence or absence of the sheet; A warning unit that is activated when any of the second detection units detects the paper, a slit formed in the guide unit so as to be perpendicular to the image carrier direction, and substantially the same as the maximum width of the paper A cutter fitted to the slit is attached to the end of the shaft having a length, and when the warning means is operated, the front cover of the apparatus main body is opened, the shaft is pulled out of the apparatus main body, and the cutter is moved. Cutting means for sliding the sheet in the slit to cut the sheet, opening the upper unit after cutting, and taking out the cut sheet in the direction of the registration roller means and the direction of the fixing means. An image forming apparatus comprising: