JPH08314355A - Electrophotographic printing device - Google Patents

Abstract

PURPOSE: To provide an electrophotographic printing device without needing the opening of an upper unit in the case paper jamming occurs and without limiting the installing space thereof. CONSTITUTION: This device is provided with a center unit 11 equipped with an electrophotographic printing process unit 50, a paper feed unit 12 disposed to be freely attached to/detached from the center unit 11, and a paper ejection unit 13 disposed to be freely attached to/detached from the center unit 11. Then, a pair of paper feeding rollers is disposed between the center unit 11 and the paper feed unit 12, and a pair of fixing rollers 32 and 33, the pairs of paper ejecting rollers 38 and 61, and 39 and 62 are disposed between the center unit 11 and the paper ejection unit 13. Either roller of the respective pairs of rollers is energized to the other roller. The paper feed unit 12 and the paper ejection unit 13 are attached/detached in a direction perpendicular to the rotary shaft of each roller.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic printer.

[0002]

2. Description of the Related Art Conventionally, in an electrophotographic printer, an electrostatic latent image is formed on the surface of a photosensitive drum by exposing the photosensitive drum whose surface is uniformly and uniformly charged, The electrostatic latent image is developed into a toner image, and the toner image is transferred and fixed on a sheet.

FIG. 2 is a sectional view of a conventional electrophotographic printing apparatus,
FIG. 3 is an open state diagram of an upper unit in a conventional electrophotographic printing apparatus. In the figure, 41 is a printer main body,
Reference numeral 43 is a lower unit, and 44 is an upper unit which is arranged so as to face the lower unit 43 and forms a sheet conveying path therebetween. The upper unit 44 is rotatably arranged around a hinge 60, and is normally locked to the lower unit 43 by a locking member such as a lock lever (not shown) so that the sheet conveying path is not opened.

A plurality of sheets 46 accommodated in the sheet cassette 45 are fed one by one to the printing apparatus main body 41 from the uppermost portion by the sheet feeding roller 47, and the fed sheets 46 are a pair of sheet feed rollers 48. The sheet is fed to the sheet feeding roller 49 and is conveyed at a constant speed by the sheet feeding roller pair 48 and 49. Further, an electrophotographic printing process unit 50 is arranged on the downstream side of the pair of paper feed rollers 48 and 49 in the conveyance direction of the paper 46. In the electrophotographic printing process unit 50, a toner image is formed on the surface of the photoconductor drum 51, and the toner image is transferred by the transfer means 52 to the sheet 4.
6 is transferred. Then, the sheet 4 on which the toner image is transferred
6 is sent to the fixing roller pair 53, 54, and the toner image is fixed on the paper 46 by the fixing roller pair 53, 54. Further, the paper 46 on which the toner image is fixed is discharged to the outside of the printing apparatus main body 41 by the discharge rollers 55 and 56.

By the way, the paper feed roller pair 48, 4
9, fixing roller pairs 53, 54 and discharge roller pairs 55, 5
Each 6 is composed of a pair of rollers. At least one roller of each roller pair is connected to a drive source (not shown) together with the photosensitive drum 51, and is rotated at substantially the same peripheral speed. Further, the other roller of each roller pair is pressed against the one roller by an urging means such as a pressing spring (not shown) and brought into close contact with the other roller.

In the upper unit 44, one roller 49 of the paper feed roller pairs 48 and 49, the photosensitive drum 51, one roller 53 of the fixing roller pairs 53 and 54, and a discharge roller pair 55, One of the rollers 56 is rotatably arranged, and an upper guide of the sheet conveyance path is arranged on the lower surface of the upper unit 44. On the other hand, the lower unit 43 includes the other roller 4 of the pair of paper feed rollers 48 and 49.
8, the other roller 5 of the fixing roller pair 53, 54
4 and the other roller 55 of the pair of discharge rollers 55 and 56 are rotatably arranged, and the transfer means 52 is arranged. Is provided.

In the electrophotographic printing apparatus having the above-described structure, the paper 46 is caught in the paper feed roller pairs 48 and 49 during printing, and the rear end of the paper 46 is fixed to the fixing roller pairs 53 and 54 during paper discharge. When the paper is jammed by being caught in the paper, the upper unit 44 is rotated around the hinge 60 and opened as shown in FIG. 3, and the urging by the urging means is released to jam the paper. The paper 46 can be removed.

[0008]

However, in the above-mentioned conventional electrophotographic printing apparatus, when a paper jam occurs, the operator has to rotate and open the upper unit 44 around the hinge 60, and therefore the printing operation is performed. It is necessary to always keep a space above the apparatus main body 41, which restricts the installation place of the electrophotographic printing apparatus.

The present invention solves the problems of the conventional electrophotographic printing apparatus described above, and when the paper jam occurs, it is not necessary to open the upper unit and the installation place is not restricted. The purpose is to provide.

[0010]

Therefore, in the electrophotographic printing apparatus of the present invention, a center unit provided with an electrophotographic printing process unit, and a center unit detachably attached to the center unit are provided. A paper feeding path is formed between the paper feeding path and the paper feeding unit for feeding the paper of the paper cassette to the electrophotographic printing process unit via the paper feeding path; A paper transport path is formed between the center unit and the toner image on the paper after transfer by the electrophotographic printing process unit is fixed via the paper transport path, and after the fixing is performed. And a paper discharge unit for discharging the paper to the outside of the printing apparatus main body.

A pair of sheet feeding rollers is provided between the center unit and the sheet feeding unit, and a pair of fixing rollers and a pair of sheet discharging rollers are provided between the center unit and the sheet discharging unit. One roller of each roller pair is biased against the other roller. Further, the paper feeding unit and the paper discharging unit are attached and detached in a direction perpendicular to the rotation axis of each roller.

[0012]

According to the present invention, as described above, in the electrophotographic printing apparatus, the center unit provided with the electrophotographic printing process unit, and the center unit provided detachably from the center unit are provided. A paper feed path that forms a paper feed path in the paper cassette, and feeds paper from a paper cassette to the electrophotographic printing process unit via the paper feed path;
After a sheet conveyance path is formed between the center unit and the toner image is fixed on the sheet after the transfer by the electrophotographic printing process unit via the sheet conveyance path, and after the toner image is fixed And a paper discharge unit for discharging the paper to the outside of the main body of the printing apparatus.

A pair of sheet feeding rollers is provided between the center unit and the sheet feeding unit, and a pair of fixing rollers and a pair of sheet discharging rollers are provided between the center unit and the sheet discharging unit. One roller of each roller pair is biased against the other roller. In this case, the sheet fed from the sheet cassette is sent to the pair of sheet feeding rollers through the sheet conveying path between the center unit and the sheet feeding unit, and is conveyed by the pair of sheet feeding rollers. And is fed to the electrophotographic printing process unit.

Then, when the toner image on the photosensitive drum is transferred onto the paper in the electrophotographic printing process unit, the paper passes through the paper conveyance path between the center unit and the paper discharge unit and the fixing roller is used. Then, the toner image is fixed on the paper. Further, the sheet after fixing is sent to a pair of paper discharging rollers, and is discharged to the outside of the printing apparatus main body by the pair of paper discharging rollers.

Further, the paper feeding unit and the paper discharging unit are attached and detached in a direction perpendicular to the rotation axis of the roller of each roller pair. In this case, the paper feed unit and the paper discharge unit are attached and detached in a direction perpendicular to the rotation axis of each roller.

[0016]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a sectional view of an electrophotographic printing apparatus according to an embodiment of the present invention, FIG. 4 is a drawing of a sheet feeding unit of an electrophotographic printing apparatus according to an embodiment of the present invention, and FIG. FIG. 3 is a drawing showing a state where a paper discharge unit of the printing apparatus is taken out.

In the figure, 10 is a printer main body, 11 is a center unit, 12 is a paper feed unit which is detachably attached to the center unit 11, and 13 is detachable from the center unit 11. It is a paper discharge unit provided. The paper feeding unit 12 is the center unit 1
1 is provided on one side surface and has a shape projecting toward the center of the center unit 11;
Is disposed on the other side surface of the center unit 11 and has a shape projecting toward the center of the center unit 11. Therefore, the center unit 11 has a shape with a constricted center.

Below the center unit 11, a sheet cassette 21 is movably arranged in the direction of arrow A and is detachably attached to the printer main body 10. Paper 46 is accommodated in the paper cassette 21, and a plurality of papers 46 are stacked on a paper stacking plate 24 that is vertically movable in the paper cassette 21, and the paper 46 is arranged below the paper stacking plate 24. It is pressed against the paper feeding roller 26 by the action of the pressing spring 25 provided. Therefore, when the sheet feeding roller 26 is rotated by a drive source (not shown), the uppermost one sheet of the sheet 46 is fed, and the printing apparatus main body 10
Is fed to the sheet suction port 28.

Then, the paper 4 in the paper cassette 21
When all 6 are used, the paper cassette 21 can be pulled out from the printing apparatus main body 10 to supply the paper 46. The center unit 11 includes a paper cassette 2
1, a paper feed roller 26 that feeds the paper 46, a paper feed roller 31 that conveys the fed paper 46 into the printer body 10, and a photoconductor drum that carries a toner image formed by the electrophotographic printing process unit 50. 51,
A transfer unit 52 arranged to face the photoconductor drum 51 to form a transfer unit, which transfers the toner image on the surface of the photoconductor drum 51 to the paper 46, from the electrophotographic printing process unit 50 in the paper transport direction. It is arranged on the downstream side,
A fixing roller 32 that fixes the toner image on the paper 46, and discharge rollers 38 and 39 that discharge the paper 46 after the toner image is fixed onto the paper tray 36 are provided.

The paper feed roller 26, the paper feed roller 31, the photosensitive drum 51, the fixing roller 32, and the discharge rollers 38 and 39 are all in the printer body 10.
It is arranged rotatably around an axis fixed to the. Further, the paper feeding roller 3 is provided in the paper feeding unit 12.
1, a pinch roller 64 is disposed so as to face the sheet feeding roller 1.
The paper 46 can be pressed against the paper feed roller 31 by being urged toward. The paper feed roller 31 and the pinch roller 64 form a paper feed roller pair.

Further, in the paper discharge unit 13, a pressure roller 33 faces the fixing roller 32, and a discharge roller 6 faces the discharge rollers 38 and 39, respectively.
1, 62 are provided. The pressure roller 33 and the discharge rollers 61 and 62 have springs 33a and 61, respectively.
a and 62a, the fixing roller 32 and the discharge roller 3
The fixing roller 3 is urged toward 8 and 39, respectively.
The paper 46 can be pressed against the sheet 2 and the discharge rollers 38 and 39. The fixing roller 3
A heating element 32a is disposed in the inside of the unit 2. In addition, the fixing roller 3
2 and the pressure roller 33 form a fixing roller pair, and the discharge roller 38 and the discharge roller 61, and the discharge roller 39 and the discharge roller 62 form a paper discharge roller pair.

Then, the paper feed roller 31 and the pinch roller 64, a roller pair, the fixing roller 32 and a pressure roller 33, a discharge roller 38 and a discharge roller 61, and a discharge roller 39 and a discharge roller. At least one of the roller pair 62 and 62 is connected to a drive source (not shown) together with the photosensitive drum 51, and is rotated at substantially the same peripheral speed.

By the way, the paper feed unit 12 and the paper discharge unit 13 are usually placed in a state of being attached to the center unit 11. When the paper feeding unit 12 and the paper discharging unit 13 are attached to the center unit 11, the space between the lower surface of the paper feeding unit 12 and the upper surface of the center unit 11 and the upper surface of the paper discharging unit 13 are A paper transport path is formed between the center unit 11 and the lower surface of the center unit 11.

Therefore, the lower surface of the paper feeding unit 12 constitutes an upper guide of the paper conveying path to the transfer portion, while the upper surface of the center unit 11 facing the paper feeding unit 12 has a paper sheet. It constitutes the lower guide of the transport path. The upper surface of the paper discharge unit 13 constitutes a lower guide of the paper conveyance path from the transfer unit to the discharge rollers 39 and 62, while the lower surface of the center unit 11 facing the paper discharge unit 13 is a paper guide. It constitutes the upper guide of the transport path.

As shown in FIG. 4, a pair of slide bars 15 are fixed on the front and back of the paper feeding unit 12, and a pair of slide bars 15 are provided on the portion of the printer body 10 corresponding to the slide bars 15. Rail 16 is fixed, and the slide bar 15 is slidably supported on the rail 16. Therefore, the paper feed unit 12 can be pulled out from the printing apparatus main body 10 in the arrow direction by sliding the slide bar 15 with respect to the rail 16.

At this time, the urging force of the pinch roller 64 on the paper feed roller 31 can be released. In addition, as shown in FIG. 5, a pair of slide bars 17 are fixed to the front and back of the paper discharge unit 13 at the bottom thereof.
A pair of rails 18 is fixed to a portion of the printer body 10 corresponding to the slide bar 17, and the slide bar 17 is slidably supported on the rail 18. Therefore, the slide bar 17 can be slid with respect to the rail 18 and the paper discharge unit 13 can be pulled out from the printing apparatus main body 10 in the arrow direction.

At this time, the urging forces of the pressure roller 33 and the discharge rollers 61 and 62 on the fixing roller 32 and the discharge rollers 38 and 39 can be released. In order to maintain the state where the paper feeding unit 12 and the paper discharging unit 13 are attached to the center unit 11, a locking member (not shown) is usually provided, and unless the locking members are opened, the paper feeding unit 12 and the paper discharge unit 13 cannot be pulled out from the printer main body 10.

In this way, by pulling out the paper feeding unit 12 from the printing apparatus main body 10, the pinch roller 64
Since the urging force of the sheet feeding roller 31 can be released, when a sheet jam occurs between the sheet feeding roller 31 and the pinch roller 64, the sheet 4 can be easily fed.
6 can be removed. Further, by pulling out the paper discharge unit 13 from the printer main body 10, the biasing force of the pressure roller 33 against the fixing roller 32 and the biasing force of the discharge rollers 61 and 62 against the discharge rollers 38 and 39 can be released. Therefore, when a paper jam occurs between the fixing roller 32 and the pressure roller 33 and between the discharge rollers 38 and 39 and the discharge rollers 61 and 62, the paper 46 can be easily removed.

Further, the slide bars 15 and 17 are
Since the paper feed roller 31 and the pinch roller 64 can be extended in the direction perpendicular to the rotation axes, the paper feeding unit 1
2 can be attached to and detached from the printing apparatus main body 10 in the same direction, and the urging force of the pinch roller 64 on the paper feed roller 31 can be released in the same direction. Further, since the rails 16 and 18 are extended in the direction perpendicular to the rotation axes of the fixing roller 32, the pressure roller 33, and the discharge rollers 38, 39, 61, and 62, the paper discharge unit 13 is connected to the printer main body. It is possible to attach / detach to / from 10 in the same direction, and it is possible to release the urging force of the discharge rollers 61 and 62 against the discharge rollers 38 and 39 in the same direction.

Moreover, when pulling out the paper feeding unit 12 from the printer body 10, the paper feeding roller 31 is used.
In order to pull out the paper discharge unit 13 from the printing apparatus main body 10, a support mechanism (not shown) for the pinch roller 64 and a support mechanism (not shown) for the fixing roller 32, the pressure roller 33, and the discharge rollers 38, 39, 61, 62 are used. No need to operate.

Further, it is not necessary to rotate and open a part of the electrophotographic printer to remove the paper 46.
Therefore, it is not necessary to reserve a space above the printing apparatus main body 10, so that the installation location of the electrophotographic printing apparatus is not restricted. Further, it becomes easy to replace the paper feeding unit 12 and the paper discharging unit 13 or replace parts.

In this embodiment, the pinch roller 64 provided in the paper feeding unit 12 and the paper discharging unit 13
Pressure roller 33 and discharge rollers 61, 62 disposed in
Although the springs 64a, 33a, 61a, 62a are biased, the paper feed roller 31, the fixing roller 32, and the discharge rollers 38, 39 can be biased.

The present invention is not limited to the above-mentioned embodiments, but can be variously modified within the scope of the present invention, and these are not excluded from the scope of the present invention.

[0034]

As described in detail above, according to the present invention, in an electrophotographic printing apparatus, a center unit having an electrophotographic printing process unit and a detachable arrangement with respect to the center unit are provided. A paper feed unit that forms a paper feed path between the center unit and the paper feed path that feeds the paper of the paper cassette to the electrophotographic printing process unit via the paper feed path; A sheet conveying path is formed between the sheet and the center unit, and the toner image is fixed on the sheet after the transfer by the electrophotographic printing process unit via the sheet conveying path. And a paper discharge unit for discharging the fixed paper to the outside of the printing apparatus main body.

A pair of sheet feeding rollers is provided between the center unit and the sheet feeding unit, and a fixing roller pair and a sheet discharging roller pair are provided between the center unit and the sheet discharging unit. One roller of each roller pair is biased against the other roller. In this case, the paper is fed from the paper cassette to the electrophotographic printing process unit, the toner image on the photosensitive drum is transferred onto the paper in the electrophotographic printing process unit, and is fixed by the pair of fixing rollers. Then, the sheet after the fixing is sent to the pair of paper ejection rollers, and is ejected to the outside of the printing apparatus main body by the pair of paper ejection rollers.

Further, the paper feeding unit and the paper discharging unit are attached and detached in a direction perpendicular to the rotation axis of each roller. In this case, the paper feeding unit and the paper discharging unit are
It can be pulled out from the printing apparatus main body while moving in a direction perpendicular to the rotation axis of the roller of each roller pair. Therefore, when a paper jam occurs in the paper feed roller pair, the fixing roller pair, and the paper discharge roller pair, the paper can be easily removed.

Moreover, since the paper feeding unit and the paper discharging unit are attached and detached in the direction perpendicular to the rotation axis of the rollers of each roller pair, the paper feeding roller pair, the fixing roller pair, and the paper discharging unit. There is no need to operate any support mechanism for the roller pair for the. Furthermore, it is not necessary to rotate and open a portion of the electrophotographic printing device to remove the paper. Therefore, it is not necessary to make a space above the main body of the printing apparatus, so that the installation place of the electrophotographic printing apparatus is not restricted.

Further, it becomes easy to replace the paper feeding unit and the paper discharging unit, or replace parts.

[Brief description of drawings]

FIG. 1 is a sectional view of an electrophotographic printing apparatus according to an embodiment of the present invention.

FIG. 2 is a sectional view of a conventional electrophotographic printing apparatus.

FIG. 3 is an open state diagram of an upper unit in a conventional electrophotographic printing apparatus.

FIG. 4 is a drawing showing a state where the paper feeding unit of the electrophotographic printing apparatus according to the exemplary embodiment of the present invention is taken out.

FIG. 5 is a drawing showing a state in which a paper discharge unit of the electrophotographic printing apparatus according to the exemplary embodiment of the present invention is taken out.

[Explanation of symbols]

 10 Printer Main Unit 11 Center Unit 12 Paper Feed Unit 13 Paper Ejection Unit 21 Paper Cassette 31 Paper Feed Roller 32 Fixing Roller 33 Pressure Roller 38, 39, 61, 62 Ejection Roller 46 Paper 50 Electrophotographic Printing Process Unit 64 Pinch Roller

Claims (1)

[Claims] 1. A center unit equipped with (a) an electrophotographic printing process unit, and (b) a detachable unit with respect to the center unit to form a paper conveyance path between the center unit and the center unit. (C) A paper feeding unit that feeds paper from a paper cassette to the electrophotographic printing process unit via a paper feeding path, and A path is formed, a toner image is fixed on the paper after the transfer by the electrophotographic printing process unit via the paper conveyance path, and the paper on which the toner image is fixed is fixed to the outside of the printing apparatus main body. In addition to having a paper discharge unit for discharging paper to
(D) A roller pair for sheet feeding is arranged between the center unit and the sheet feeding unit, and a roller pair for fixing and a roller pair for sheet discharging are arranged between the center unit and the sheet discharging unit. (E) One roller of each roller pair is urged against the other roller, and (f) the paper feeding unit and the paper discharging unit are attached / detached in a direction perpendicular to the rotation axis of each roller. An electrophotographic printing device characterized by.