JPH07168408A - Electrophotographic printer - Google Patents

Abstract

PURPOSE:To easily remove a paper sheet jammed inside a device main body without soiling a hand by providing a pressurization releasing mechanism separating a pinch roller from a feeding roller and a pressure roller from a fixing roller respectively. CONSTITUTION:When a photoreceptor drum unit 8 is removed, a head member 22 fitted into a guiding hole 20 is moved to the right by the repulsive force of a spring member 21 and the tip of the head member 22 is projected from the guiding hole 20 by the movement. At this time, an arm member 19 is rotated clockwise centering a supporting shaft 18 and simultaneously the pinch roller 7 is separated from the feeding roller 6 in accordance with the rotational action of the arm member 19, to release the pressurizing state of the pinch roller 7 with respect to the feeding roller 6. Similarly. a sliding member 26 is moved to the left and the pressure roller 13 is separated from the fixing roller, to release the pressurizing state of the pressure roller 13 with respect to the fixing roller. Thus, a printing medium jammed in the device main body can be easily removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic printing apparatus for printing an image on a printing medium, and is particularly suitable for use when removing a printing medium jammed inside the apparatus body.

[0002]

2. Description of the Related Art FIG. 5 is a schematic side view showing the structure of a conventional electrophotographic printing apparatus. In the figure, reference numeral 51 denotes an apparatus main body, and a medium storage container (hereinafter referred to as a paper cassette) 52 is arranged at the bottom of the apparatus main body 51. Inside the paper cassette 52, a vertically movable paper stacking plate 53 is provided, and a print medium (hereinafter, referred to as paper) 54 stacked on the paper stacking plate 53 is pressed against a feeding roller 56 by an elastic force of a push-up spring 55. ing. Further, reference numeral 57 in the figure denotes a feed roller pair, which comprises a feed roller 58 and a pinch roller 59. Of these, the feed roller 5
7 is connected to a power source (not shown), and the pinch roller 5
9 is pressed against the feed roller 58 by a pressing mechanism (not shown).

On the other hand, reference numeral 60 in the figure denotes a photosensitive drum unit, which is detachably incorporated in the apparatus main body 51. The photosensitive drum unit 60 has a photosensitive drum 61 on the surface of which a toner image is formed, and a transfer roller 62 is in pressure contact with the photosensitive drum 61. Further, reference numeral 63 in the drawing denotes an image fixing roller pair, which is the fixing roller 6
4 and a pressure roller 65. this house,
The fixing roller 64 is connected to a power source (not shown), and the pressure roller 65 is a pressing mechanism (not shown).
Pressed to No. 4.

In the conventional electrophotographic printer having the above structure, the paper 54 stored in the paper cassette 52 is
However, by the rotation of the feeding roller 56, the sheets are fed one by one from the top. Also, the paper 5 thus fed out
4 is fed to the feed roller pair 57 via the paper feed roller pair 66. In the feed roller pair 57, the paper 54 is sandwiched between the feed roller 58 and the pinch roller 59, and the feed roller 58 is rotated by the driving of a power source (not shown) to feed the paper 54 onto the photosensitive drum 61. To do.

Paper 54 fed on the photosensitive drum 61
Is conveyed by the rotation of the transfer roller 62 while being pressed against the photosensitive drum 61 side by the transfer roller 62. At that time, the paper 54 pressed against the photosensitive drum 61
The toner image formed on the drum surface is transferred to. Then, the sheet 54 on which the toner image is transferred is sent to the image fixing roller pair 63. Image fixing roller pair 6
3, the sheet 54 is nipped between the fixing roller 64 and the pressure roller 65, and the sheet 54 is rotated by the rotation of the fixing roller 64.
To transport. At this time, the toner image is fixed on the sheet 54 by the heating action of the fixing roller 64 and the pressure action of the pressure roller 65. Finally, the paper 54 is sent to the discharge roller pair 68 via the paper discharge roller pair 67, and is discharged from there to a discharged paper storage container (hereinafter referred to as a stacker) 69.

By the way, in this type of electrophotographic printing apparatus, when the paper 54 is jammed inside the apparatus main body 51, the drive of the apparatus is stopped so that the paper 54 can be prevented in order to prevent the failure of the apparatus. A panel or the like indicates which part of the sheet 51 is jammed so that the operator can easily find the jammed sheet (jam sheet) 54 to prompt the removal of the jammed sheet. Then, when removing the jammed paper, first, the cover lid 7 provided on the upper portion of the apparatus main body 51.
0 to open the photosensitive drum unit 60 from the apparatus main body 51.
Is removed to open the inside of the apparatus main body 51. Then
The paper 54 jammed during the transportation is removed from the apparatus body 51, the photosensitive drum unit 60 is attached to the apparatus body 51 again, and the cover lid 70 is closed.

[0007]

However, the above-mentioned conventional electrophotographic printing apparatus has the following problems. That is, the paper 54 jammed in the apparatus main body 51
Is firmly sandwiched by the feed roller pair 57 or the image fixing roller pair 63, the jammed paper 54 cannot be easily pulled out even if the photosensitive drum unit 60 is removed to open the inside of the apparatus main body 51. It was
Also, if you pull it out forcibly, the paper 54 will be torn,
A part of the paper sheet 54 remains on the apparatus main body 51, and in some cases, a service person must be called.

Further, since the toner image transferred onto the jammed paper 54 is in the unfixed state before passing through the image fixing roller pair 63, the toner image is transferred from the apparatus main body 51 to the paper 5.
When pulling out No. 4, there was a concern that the hand would get dirty with the toner (colored synthetic resin).

The present invention has been made to solve the above problems, and provides an electrophotographic printing apparatus capable of easily removing paper (printing medium) jammed inside the apparatus body without soiling hands. The purpose is to do.

[0010]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and has a photosensitive drum on the surface of which a toner image is formed, and a photosensitive drum unit detachably incorporated in the main body of the apparatus. And a feed roller and a pinch roller in pressure contact with the feed roller, and a feed roller pair for feeding the print medium fed from the medium storage container onto the photosensitive drum, and a print medium fed by the feed roller pair. The transfer roller is sandwiched between the photosensitive drum and transfers the toner image formed on the surface of the photosensitive drum to the print medium, a fixing roller and a pressure roller in pressure contact with the fixing roller. And a pair of image fixing rollers for fixing the toner image to the print medium, a state in which the photosensitive drum unit is removed from the apparatus main body. And a second pressure releasing mechanism for separating the pinch roller from the feeding roller and a second pressure releasing mechanism for separating the pressure roller from the fixing roller when the photosensitive drum unit is removed from the apparatus main body. is there.

Further, the above-mentioned photosensitive drum unit is arranged so as to face the apparatus main body, and a medium guide side that forms a medium traveling path between the apparatus main body and the apparatus main body side in a state where the photosensitive drum unit is removed from the apparatus main body. To the medium guide side via the medium running path.

[0012]

In the electrophotographic printing apparatus of the present invention, when the photosensitive drum unit is removed from the main body of the apparatus, the pinch roller is separated from the feed roller by the first pressure release mechanism, and at the same time, the pinch roller is applied by the second pressure release mechanism. Since the pressure roller separates from the fixing roller, it is possible to easily pull out and remove the print medium jammed in the apparatus main body from the feed roller pair or the image fixing roller pair.

Further, in the present invention, when the photosensitive drum unit is removed from the apparatus main body, the medium holding member is pressed against the medium guide side from the apparatus main body side through the medium running path, whereby the printing medium jammed in the apparatus main body. Is held between the medium guide side and the medium holding member, it is possible to take out the print medium from the apparatus main body integrally with the photosensitive drum unit.

[0014]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a schematic side view showing a first embodiment of an electrophotographic printing apparatus according to the present invention. In the figure, reference numeral 1 denotes an apparatus main body, and a paper cassette (medium storage container) 2 is arranged at the bottom of the apparatus main body 1. A sheet stacking plate (not shown) is provided inside the sheet cassette 2, and sheets (print media) 3 stacked on the sheet stacking plate 3 are pressed against the feeding roller 4 by a push-up member (not shown). Further, reference numeral 5 in the drawing denotes a feed roller pair, which is composed of a feed roller 6 and a pinch roller 7. Of these, the feed roller 6 is connected to a power source such as a motor, and the pinch roller 7 is in pressure contact with the feed roller 6.

On the other hand, reference numeral 8 in the drawing denotes a photosensitive drum unit, and the photosensitive drum unit 8 integrally comprises a developing device, a charging device and the like, and is detachably incorporated in the apparatus main body 1. The photosensitive drum unit 8 carries a photosensitive drum 9, and a toner image is formed on the surface of the photosensitive drum 9 by an electrophotographic printing process. Further, a transfer roller 10 is pressed against the photosensitive drum 9 of the photosensitive drum unit 8 with a predetermined pressing force, and the transfer roller 10 is connected to a power source (not shown) such as a motor.

Reference numeral 11 in the figure denotes an image fixing roller pair, which is composed of a fixing roller 12 and a pressure roller 13. Of these, the fixing roller 12 is connected to a power source (not shown) such as a motor, and the pressure roller 13 is connected.
Are in pressure contact with the fixing roller 12. Also, the fixing roller 1
A heating element 14 such as a heater lamp is incorporated in the inside of the unit 2.

In the electrophotographic printing apparatus of the first embodiment having the above-mentioned structure, the sheets 3 stored in the sheet feeding cassette 2 are moved from the uppermost position by the rotation of the feeding roller 4 driven by a power source (not shown). It is delivered one by one. Also,
The sheet 3 thus fed out is fed to the pair of feed rollers 5, where it is nipped between the feed roller 6 and the pinch roller 7. Then, the feed roller 6 is rotated by driving a power source (not shown), so that the sheet 3 is fed onto the photosensitive drum 9.

Next, the sheet 3 fed onto the photosensitive drum 9 is conveyed by rotation of the transfer roller 10 driven by a power source (not shown) while being pressed against the photosensitive drum 9 side by the transfer roller 10. At that time, the photosensitive drum 9
The toner image formed on the drum surface is transferred to the sheet 3 pressed against. Then, the sheet 3 to which the toner image is transferred is sent to the image fixing roller pair 11.
In the image fixing roller pair 11, the sheet 3 is sandwiched between the fixing roller 12 and the pressure roller 13, and the sheet 3 is conveyed by rotation of the fixing roller 12 driven by a power source (not shown). At that time, the toner image is fixed on the sheet 3 by the heating action of the fixing roller 12 and the pressure action of the pressure roller 13. Here, the surface of the fixing roller 12 is maintained at a temperature for melting the toner adhering to the paper 3 by the power supply control means connected to the heating element 14.
Finally, the sheet 3 that has passed through the image fixing roller pair 11 is sent to the discharge roller pair 16 via the discharge roller pair 15.
The sheet is discharged from the pair of discharging rollers 16 to the stacker 17.

Here, in the electrophotographic printing apparatus of the first embodiment, in addition to the above-described configuration, the pinch roller 7 is provided with the photosensitive drum unit 8 removed from the apparatus main body 1.
A first pressure release mechanism for separating the roller from the feed roller 6,
Similarly, a second pressure releasing mechanism for separating the pressure roller 13 from the fixing roller 12 when the photosensitive drum unit 8 is removed from the apparatus main body 1 is provided.

First, the first pressure release mechanism is formed in the apparatus body 1, for example, a support shaft 18 provided in the apparatus body 1, an arm member 19 rotatably supported by the support shaft 18. The guide member 20 includes a spring member 21 inserted into the guide hole 20 and a head member 22 movably fitted into the guide hole 20.

More specifically, the arm member 19 has an L-shaped structure as a whole, the pinch roller 7 is rotatably attached to one end side thereof, and the one end side of the spring member 21 is in contact with the other end side thereof. ing. The spring member 21 is interposed between the arm member 19 and the head member 22 in the guide hole 20 of the apparatus body 1. Head member 22
Has a structure in which the tip end side projects from and retracts in the guide hole 20 by moving along the guide hole 20, and the other end side of the spring member 21 is in contact with the rear end portion. Then, as shown in FIG. 1, when the photosensitive drum unit 8 is attached to the apparatus main body 1, the head member 22 is pushed into the guide hole 20 by the photosensitive drum unit 8. In this state, the elastic force of the spring member 22 acts to urge the other end of the arm member 19 in the direction of arrow A in the figure, and the pinch roller 7 is urged by this urging force.
Is pressed against.

On the other hand, the second pressure releasing mechanism is formed in the apparatus main body 1, for example, a support shaft 23 provided in the apparatus main body 1, a support arm 24 rotatably supported by the support shaft 23. The slide member 26 is movably engaged with the formed guide groove 25, and the spring member 27 is interposed between the support arm 24 and the slide member 26.

More specifically, the support arm 24 has an L-shaped structure like the arm member 19, the pressure roller 13 is rotatably attached to one end side thereof, and the spring member 27 is attached to the other end side thereof. Is in contact with one end side of. As the slide member 26 moves along the guide groove 25, the tip end side of the slide member 26 projects from the guide groove 25, and the other end side of the spring member 27 is in contact with the rear end portion. Then, as shown in FIG. 1, when the photosensitive drum unit 8 is attached to the apparatus main body 1, the front end side of the slide member 26 is pushed into the guide groove 25 by the photosensitive drum unit 8. In this state, the elastic force of the spring member 27 acts to urge the other end of the support arm 24 in the direction of arrow B in the drawing, and the pressure roller 13 is pressed against the fixing roller 12 by this urging force. .

Next, the procedure for removing the paper 3 jammed inside the main body 1 of the electrophotographic printing apparatus of the first embodiment will be described. First, when it is confirmed by the panel display or the like that the sheet 3 is jammed in the apparatus body 1, the cover lid 28 provided on the upper portion of the apparatus body 1 is opened. As a result, the upper portion of the apparatus body 1 is opened, and the photosensitive drum unit 8 is removed from the apparatus body 1 through the opening.

When the photosensitive drum unit 8 is removed from the apparatus main body 1 in this way, as shown in FIG.
The head member 22 fitted in 0 moves to the right in the figure by the elastic force of the spring member 21.
The leading end of the head member 22 is projected from. At that time, the arm member 19 rotates clockwise around the support shaft 18, and the pinch roller 7 separates from the feed roller 6 as the arm member 19 rotates.
The pressed state of the pinch roller 7 with respect to is released.

When the photosensitive drum unit 8 is removed from the apparatus main body 1 in the same manner as described above, as shown in FIG.
The slide member 26 engaged with the guide groove 25 moves leftward in the drawing by the elastic force of the spring member 27, whereby the tip end side of the slide member 26 projects from the guide groove 25. At that time, the slide member 26 rotates counterclockwise around the support shaft 23, and
The pressure roller 13 is separated from the fixing roller 12 in accordance with the rotation operation of 1. and the pressure state of the pressure roller 13 against the fixing roller 12 is released.

As described above, in the electrophotographic printing apparatus of the first embodiment, by removing the photosensitive drum unit 8 from the apparatus main body 1, the pinch roller 7 is pressed against the feed roller 6 and the fixing roller 12 is pressed. The pressed state of the roller 13 is released at the same time. Therefore, when the paper 3 is jammed while passing through the pair of feed rollers 5 or the pair of image fixing rollers 11, the photosensitive drum unit 8 is removed from the apparatus main body 1 to feed the pinch roller 7 by the first pressure release mechanism. The roller 6 is separated from the roller 6, and at the same time, the pressure roller 13 is pressed by the second pressure releasing mechanism.
Is separated from the fixing roller 12, the paper 3 jammed in the apparatus main body 1 can be easily pulled out and removed.

When the photosensitive drum unit 8 is again attached to the apparatus main body 1 after removing the jammed paper 3 in this way, the head member 22 is guided along the guide hole 20 by contact with the photosensitive drum unit 8. The slide member 26 is pushed back to the left, and at the same time, the slide member 26 is guided by the guide groove 25.
Is pushed back in the right direction in the figure. As a result, the elastic force of the spring member 21 acts again to rotate the arm member 19 counterclockwise, and the pinch roller 7 returns to the state of being pressed against the feed roller 6 as the arm member 19 rotates. At the same time, the elastic force of the spring member 27 acts to rotate the support arm 24 in the clockwise direction, and the rotation of the support arm 24 causes the pressure roller 13 to return to the state of being pressed against the fixing roller 12. .

Next, a second embodiment of the electrophotographic printing apparatus according to the present invention will be described with reference to FIG. The electrophotographic printing apparatus of the second embodiment has a main characteristic part in the construction of the photosensitive drum unit 8 in the first embodiment. That is, the photosensitive drum unit 8 includes the support shaft 2
9, a swing arm 30 that is rotatably supported by a shaft 9, and a support shaft 29.
A spring member (torsion coil spring) 31 attached to the medium, and a medium holding member 32 attached to the tip of the swing arm 30.
And are provided. Among them, the spring member 31 is hooked on the rotary shaft 33 of the photosensitive drum 9 and the tip end side of the swing arm 30, and thereby the swing arm 30 is biased in the clockwise direction. Further, the rear end portion of the swing arm 30 is abutted against the projection 34 formed on the apparatus main body 1 side, whereby the swing arm 30 resists the biasing force of the spring member 31 and moves slightly counterclockwise. It has been pushed back.

Here, the photosensitive drum unit 8 has a medium guide side 35 which is disposed below the photosensitive drum unit 8 so as to face the apparatus main body 1. Between the medium guide side 35 and the apparatus main body 1 which faces the medium guide side 35. The medium running path 36 is formed by. Further, a concave portion 37 is provided on the side of the apparatus body 1 facing the medium guide side 35. Then, as shown in FIG. 3, in the state where the photosensitive drum unit 8 is attached to the apparatus main body 1, the rear end portion of the swing arm 30 has the protrusion 3
When the medium holding member 32 hits the concave portion 3,
It is arranged in a state of being retracted in 7.

On the other hand, when the photosensitive drum unit 8 is removed from the apparatus body 1 due to the paper 3 jammed inside the apparatus body 1, the rear end of the swing arm 30 separates from the protrusion 34 of the apparatus body 1. The swing arm 30 rotates clockwise according to the biasing force of the spring member 31. As a result, as shown in FIG. 4, the medium holding member 32 at the tip of the swing arm 30 moves from the recess 37 on the side of the apparatus main body 1 to the medium running path 3.
6 via the medium guide side 35 of the photosensitive drum unit 8 side
It will be in a state of being pressed against. At this time, the sheet 3 jammed inside the apparatus main body 1 is pinched between the medium guide side 35 and the medium pinching member 32 by the urging force of the spring member 31, so that it is integrated with the photosensitive drum unit 8 in the apparatus main body. Taken out from 1.

By the way, when separating the paper 3 from the photosensitive drum unit 8, the rear end of the swing arm 30 is pushed by a finger or the like to resist the biasing force of the spring member 31 and the swing arm 30.
Rotate clockwise. Then, the medium guide side 3
Since the medium holding member 32 separates from the sheet 5, the sheet 3 can be easily separated from the photosensitive drum unit 8.

[0033]

As described above, according to the electrophotographic printing apparatus of the present invention, by removing the photosensitive drum unit from the apparatus main body, the pressure state of the feed roller pair and the pressure state of the image fixing roller pair can be changed. Since they are released at the same time, it is possible to easily remove the print medium jammed in the apparatus main body, and it is possible to recover the apparatus in a short time from the occurrence of a jam of the print medium. Also, when the device is not used for a long period of time, or when the device is transported, by removing the photosensitive drum unit from the device body and releasing the pressure applied by each roller pair, the It is possible to prevent deformation of the parts, and further damage of parts due to vibration or shock during transportation.

Further, according to the present invention, when the photosensitive drum unit is removed from the apparatus main body, the printing medium jammed in the apparatus main body is held between the medium guide side and the medium holding member, and the photosensitive drum unit is held. Since it is taken out from the main body of the device integrally with the operator, it is not necessary for the operator to insert the hand into the main body of the device to pull out the print medium, which may cause the unfixed toner image to be touched and soil the hand. Will be resolved.

[Brief description of drawings]

FIG. 1 is a schematic side view showing a first embodiment of an electrophotographic printing apparatus according to the present invention.

FIG. 2 is a schematic side view illustrating an operation function in the first embodiment.

FIG. 3 is a side view of essential parts showing a second embodiment of the electrophotographic printing apparatus according to the present invention.

FIG. 4 is a side view of a main part for explaining an operation function in the second embodiment.

FIG. 5 is a schematic side view showing a configuration of a conventional electrophotographic printing apparatus.

[Explanation of symbols]

1 Device Main Body 2 Paper Cassette (Media Storage Container) 3 Paper (Print Medium) 5 Feed Roller Pair 6 Feed Roller 7 Pinch Roller 8 Photosensitive Drum Unit 9 Photosensitive Drum 10 Transfer Roller 11 Image Fixing Roller Pair 12 Fixing Roller 13 Pressure Roller 18 Support Shaft 19 Arm Member 20 Guide Hole 21 Spring Member 22 Head Member 23 Support Shaft 24 Support Arm 25 Guide Groove 26 Slide Member 27 Spring Member 32 Medium Clamping Member 35 Medium Guide Side 36 Medium Travel Path

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location G03G 15/20 107

Claims (2)

[Claims] 1. A medium storage container comprising a photosensitive drum unit having a photosensitive drum on the surface of which a toner image is formed and detachably incorporated in the apparatus main body, a feed roller and a pinch roller in pressure contact with the feed roller. Formed on the surface of the photosensitive drum by sandwiching the print medium fed by the feed roller pair with the feed roller pair that feeds the print medium fed out from the photosensitive drum onto the photosensitive drum. An image fixing roller that includes a transfer roller that transfers the formed toner image to the print medium, a fixing roller, and a pressure roller that is in pressure contact with the fixing roller, and that fixes the toner image transferred by the transfer roller to the print medium. In an electrophotographic printing apparatus including a pair, the pinch low in a state where the photosensitive drum unit is removed from the apparatus main body. A first pressure releasing mechanism for separating the pressure roller from the fixing roller, and a second pressure releasing mechanism for separating the pressure roller from the fixing roller in a state where the photosensitive drum unit is removed from the apparatus main body. An electrophotographic printing device characterized by the above. 2. The photosensitive drum unit is arranged so as to face the apparatus main body and forms a medium running path between the apparatus main body and a medium guide side, and the photosensitive drum unit is removed from the apparatus main body. The electrophotographic printing apparatus according to claim 1, further comprising: a medium sandwiching member that comes into pressure contact with the medium guide side from the apparatus body side via the medium traveling path.