JP3050376B2 - Electrophotographic equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small-sized electrophotographic apparatus used as a facsimile, a printer, and a copying machine, and more particularly to an electrophotographic apparatus for facilitating jam processing of a recording material on which a toner image is transferred. .

[0002]

2. Description of the Related Art Conventionally, an electrophotographic apparatus which is smaller than a conventional one is generally constructed so that an upper body and a lower body can be divided and opened along a recording paper conveyance path in order to facilitate jam clearance. However, when the main body divided open type structure is adopted, not only the accuracy and rigidity required to withstand the opening operation on each main body side, but also a spring or the like for reducing the opening operation is required, and the device configuration is This leads to complication and an increase in the weight burden.

In the above-described apparatus, the developing device is generally disposed on the upper main body side. With such a configuration, the developing sleeve in the developing device is subjected to an impact force applied when the upper main body is opened. The toner carried on
The inside of the apparatus and the recording paper transport path are easily contaminated. Further, in an apparatus using a fixing roller pair including a heating roller and a pressure roller as a fixing unit for an unfixed toner image, the space between the fixing roller pair is also exposed when the transport path is opened, and there is a problem in safety. For this reason, in the device, the heating roller is configured to be capable of being cut off in conjunction with the main body dividing operation. However, even with such a configuration, the heating roller is sufficiently heated immediately after the cutoff, and In addition to the safety problem, once the power is turned off, the return time to the fixing temperature at which printing can be performed becomes long even when the power is turned on again after the jam has been cleared.

In order to solve such a drawback, a transport unit is integrally formed with a paper feed roller, a registration roller, a transfer roller, a transport guide, and a fixing roller pair mounted on the transport path, and the transport unit is mounted on a drum. There has been proposed an apparatus which can be taken out along the axial direction. (Japanese Patent Application Laid-Open No. Sho 64-20564)

However, the configuration in which the unit can be pulled out along the direction perpendicular to the recording paper transport direction as described above is apt to cause the jammed paper to be easily caught on the photosensitive drum or the like.
The drum may be damaged. For this reason 2-35
As shown in Japanese Patent No. 314, the unit is divided into a unit including a fixing roller pair and a unit on the upstream side thereof, and each unit is attached so as to be able to be pulled out in a direction away from each other and parallel to the recording material conveyance path. Is disclosed.

[0006]

However, in the above-described apparatus, the unit is drawn out to each side wall (or front and rear walls) of the apparatus body in accordance with the jam position, so that the operation space for jam processing is unnecessary. And the processing operation becomes complicated. In addition, as described above, when the unit including the fixing roller is configured to be able to be pulled out of the apparatus main body, the heating roller must be turned off at the time of the pulling out, which not only has a problem in safety but also has a problem. It is necessary to wait for a time until the fixing temperature rises due to re-energization after the jam processing.

Further, there has been proposed an apparatus in which the fixing roller pair is fixed to the apparatus main body side without being formed into a unit, and only the conveying unit located on the upstream side thereof can be pulled out to the sheet feeding side along the conveying direction. (Japanese Unexamined Patent Publication No. 60-63563)
However, taking the transport unit out of the apparatus every time the jam is cleared not only increases the weight burden on the operator, but also causes the transport unit to extend in the tangential direction of the photosensitive drum. The amount is also increased, which leads to a substantial increase in the work load.

[0008] Further, without forming the transfer path substantially linearly in the tangential direction of the drum, all transfer processing means arranged on the transfer path while forming a transfer path reversibly in a U-shape at the transfer position are integrated. There is also a technology in which the unit body is formed into a unit and the unit body can be taken out in parallel with the transport direction. However, forming the transport path in a U-shape is not preferable because the entire apparatus becomes thick.

In view of the above-mentioned drawbacks of the prior art, the present invention provides an electrophotographic apparatus capable of performing jam processing safely and easily without causing tearing of the recording material even when the fixing roller pair is left on the apparatus main body side. It is intended to provide a device. It is a further object of the present invention to provide an electrophotographic apparatus capable of easily performing jam processing without increasing the burden on an operator.

[0010]

According to the present invention, there is provided a recording material conveying path extending from a recording material feeding end to an entrance end of a thermal fixing means having a pair of fixing rollers, at least one side of which is a heating roller, in a recording material conveying direction. Claim 1 is the same as the prior art in that a transfer unit is provided in which at least a part of the transfer unit is unitized, and the transfer unit can be drawn out along a direction substantially orthogonal to the axis of the photosensitive drum. The invention described above is particularly preferable in the recording material conveying direction from the recording material feeding end.
Has a fusing roller pair, at least one side of which is a heating roller
At least in the recording material conveyance path to the entrance end of the heat fixing means.
A transport unit that is partly unitized,
Move the unit along a direction substantially perpendicular to the photosensitive drum axis.
Drawable to configure Te, when mounting of the transport unit
Releasing the pressure contact of said fixing roller pair in a state to maintain the energized state and the pressed state of the fixing roller pair of the heating roller, to draw the transport unit to a predetermined amount than the mounting position is maintained the energized condition of said heating roller It is allowed, characterized in that has a structure which Setsuden the heating roller pressure while releasing of the fixing roller pair when pulled out the <br/> transport unit the predetermined amount or more.

[0011] invention stages drawer to locked temporary engagement at its intermediate position when the drawer along a direction substantially perpendicular to the photosensitive drum axis the conveying unit further embodying the prior SL onset light according to claim 2, wherein the mechanism is provided, the conveying unit
During the drawer, the middle position to the locking phase of the to release the pressure of the fixing roller pair while maintaining the energized state of the <br/> heating roller, locking position of the transport unit at said intermediate position An electrophotographic apparatus characterized in that when a further pull-out operation is performed beyond the above , the heating roller is turned off in a state where the pressure contact of the fixing roller pair is released.

In any of the above-mentioned inventions, the transport unit and the paper feed cassette may be integrally formed, or they may be configured so that they can be taken out separately from the paper feed cassette. It is a problem. Moreover, the way the stepwise drawer mechanism to locked temporary locking in position, it is possible to use mechanical locking means such as engagement recesses and the engagement projections as the example Examples below.

[0013]

According to the present invention, the recording material transport path of the transport unit can be drawn out to a predetermined amount in the first aspect.
The transport unit for the predetermined amount according to the jam position.
It is only necessary to pull out the knit, and in the second aspect, since it is configured to be able to be pulled out stepwise, it is sufficient to pull out the transport unit in accordance with the jam position, thereby reducing the work load on the operator. Particularly, in the present invention, since the energized state of the heating roller is maintained during the jam processing, the fixing operation can be quickly restarted after the jam processing.

Therefore, according to the present invention, it is not necessary to uniformly turn off the heating roller at the time of jam processing, so that the warm-up time after the jam processing can be greatly reduced, and the printing operation can be promptly shifted. When the transfer unit is completely removed from the apparatus, the heating roller is turned off.
By performing F, in other words, when the fixing roller is exposed, it is possible to cut off the electric power, so that it is easy to ensure safety.

Further, in the first aspect, the transfer unit
Until the cartridge is pulled out of the mounting position to a predetermined amount, the heating
While the energized state of the roller is maintained, the fixing roller pair
The pressure contact is released, and in the second aspect, the transfer is performed.
When pulling out the unit, up to the locking stage at the halfway position
Is the fixing while the energized state of the heating roller is maintained.
Since the pressure contact of the roller pair is released, one end of the recording material
When a jam occurs while being pinched by the fixing roller pair
Also in this case, the jammed recording material is
Can be easily removed
There is also fixing because the thermal contact of the jam paper is released
Fire even if the heating roller of the roller pair is energized
No danger of toner and prevents toner sticking to the opposite side of the fixing roller
come.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be illustratively described in detail below with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, and are merely illustrative examples. Only. FIG. 1 shows an internal configuration of a page printer according to an embodiment of the present invention. In detail, the apparatus has a substantially rectangular shape with the operation surface on the right side of the figure, and the photosensitive drum 1 is disposed substantially at the center thereof, and the rotation direction of the photosensitive drum 1 The exposure optical system 2 is arranged at an upper position, the developing device 3 is arranged at a right position, the transfer device 4 is arranged below, and a cleaning means 5, an eraser 6 and a charger 61 are arranged at a left position. Is configured to perform a known electrophotographic process while rotating in the direction of an arrow.

A transfer unit 10 in which the transfer unit 4 and the paper feed cassette 7 are integrally incorporated is disposed under the photosensitive drum 1 over substantially the entire area of the apparatus. Opening 21 provided on the operation surface on the right side in the figure
The paper feed cassette 7 and the paper cassette 7 can be integrally pulled out. That is, the transport unit 10 has a paper feed cassette storage portion 11 formed over almost the entire bottom area of the apparatus, and a transport path formed on the upper surface of the storage portion 11 along a direction substantially tangential to the transfer position of the drum 1. The main body 12 includes a paper feed roller 8, a registration roller pair 9, a transfer unit 4, and an entrance of the fixing unit 30 along the transport path from the paper feed end side of the cassette 7 on the right side in the figure. A transport guide 13 extending to the end is formed, and the transport guide 1
After the end of 3 is bent downward in a stepped manner, it is connected to the storage section upper wall 111.

The upper wall 111 of the storage section extends horizontally from the continuous position to the paper discharge side, and the discharge side surface 111a of the step 112 is provided at a position facing the fixing unit 30 through an inclined step 112. It extends horizontally with its position slightly lowered. On the other hand, an engagement protrusion 113 engageable with an engagement recess 22 provided on the front wall side of the apparatus is provided on the lower surface side of the storage unit 11.
Are locked at an intermediate position.

A paper cassette 7 is removably mounted in the storage section 11. The paper feed cassette 7 is mounted on the apparatus main body side, or
2, the sheet cassette 7 can be taken out of the transport unit 10 as shown in FIG. 2, thereby facilitating sheet feeding or cassette replacement.

On the other hand, the fixing unit 30 comprises a pair of fixing rollers 31 and a pair of paper discharge rollers 32 arranged on the exit side thereof, as will be described later in detail, and a switching operation of a switching lever 23 arranged downstream of the fixing unit 30. Thus, the recording material after fixing the image can be selectively discharged to the upper surface of the apparatus via the reversing guide 24 and discharged to the discharge tray 25 provided on the left side wall of the apparatus. .

The apparatus main body includes a housing portion 26 on the sheet discharge side, which includes a housing section 26 extending from the left side wall including the reversing guide 24 to the apparatus upper wall on the upper surface of the developing device 3 through the sheet discharge section on the apparatus upper surface. , So that toner exchange in the developing device 3 and jam clearance in the reversing guide 24 are facilitated. In this case, the developing device 3
Since the photoconductor drum 1 and the fixing unit 30 are both left on the apparatus main body side, there is no weight burden on the housing part 26 which is divided and opened, and the toner scatter and the heat roller part 31a of the fixing roller are not provided. There is no exposure.

Next, the fixing unit 3 which is a main component of the present invention.
A description will be given of a fitting / removing structure between the transfer unit 10 and the transfer unit 10. First, as shown in FIG.
The width of the cassette 7 housing section 11 in the width direction is set slightly larger than the width of the unit body 12, and
Of the fixing unit 30 is formed so as to be able to face the lower ends of the axial end walls 33 of the fixing unit 30. On the other hand, the fixing unit 30
As shown in FIG. 2A, a heat roller 31a is supported between the end walls 33 and a pressure roller 31b that rotates synchronously with the roller. The pressure roller 31b has a swing mechanism 34 on the shaft end side. It is configured to be able to swing in a direction to be separated from and brought into contact with the heat roller 31a.

That is, the swing mechanism 34 includes a lever member 35 that engages with the shaft of the pressure contact roller 31b and swings about the fulcrum 351 in a direction of separating from and coming into contact with the heat roller 31a.
One pressure contact spring 36 disposed between the roller outlet side lower surface of the lever member 35 and the unit bottom surface to urge the lever member 35 upwardly with elastic force, and along the lower surface side of the lever member 35 An operating lever 37 that extends and swings around a fulcrum 371 provided at the lower end of the fixing unit at the entrance side, is engaged between the right end side of the operating lever 37 and the end wall 33, and moves the operating lever 37 counterclockwise. By swinging the lever member 3
And a separation spring 38 for biasing the pressing roller 31b away from the heat roller 31a through the separation roller 38. The other end of the operating lever 37 is connected to the fixing unit 30.
It extends beyond the lower surface to the projecting position 112 of the storage section upper wall 111, and a roller 39 is supported at its free end to support the storage section upper wall 1.
11 is configured to be relatively movable. Operating lever 37
A switch means 40 is provided on the end wall 33 of the fixing unit 30 at the rotation position of the above, and when the operation lever 37 is rotated by a predetermined angle or more, in other words, when the operation roller 37 is completely free, the heat roller 31a is energized. It is configured to be able to be turned off.

Next, the operation of the embodiment will be described. First, when a predetermined electrophotographic operation is performed, the feeding unit 8 uses the feed roller 8 to reversely feed the recording material from the feed storage unit 11 to the start end of the feeding path.
At the entrance end of On the other hand, on the photosensitive drum 1 side, after the latent image written by the exposure optical system 2 is visualized by the developing device 3 by the rotation thereof, the latent image is formed at the entrance end of the registration roller 9 in synchronization with the start of the toner image. After the waiting recording material is guided to the transfer position and the unfixed toner image is transferred, the recording material is inserted into the fixing roller pair 31 via the transport guide 13 to fix the image, and then the paper discharge roller It is led to 32. When performing page alignment, the switching lever 23 is used.
Is switched to the lower side, and the paper is discharged to the upper surface side of the apparatus via the reverse discharge guide 24. By switching the switching lever 23 to the upper side, the toner image is discharged onto the paper discharge tray 25 while facing upward.

When the recording material is to be replaced, only the paper feed cassette 7 needs to be taken out as shown in FIG. 2, and if a jam occurs during the recording operation, the transport unit 10 is pulled out. First, the engagement protrusion 113 on the lower surface side of the unit is engaged with the engagement recess 22 provided on the front wall side of the apparatus, and the conveyance surface up to the transfer position is pulled out, so that the jam occurring at that portion can be removed. If the jam further occurs on the back side, the whole unit 10 can be taken out by further pulling out the unit 10 while slightly lifting it up. In this case, even when a part of the recording material is engaged in the fixing roller pair 31, the pressure contact between the roller pair 31 is released in conjunction with the unit pull-out operation.

That is, the control operation of the fixing unit will be described in detail with reference to FIG. 3. First, when the transport unit 10 is mounted, the fixing unit 3
Since the operating lever 37 on the 0 side is maintained in the direction of pulling the spring 38 against the elastic force of the separation spring 38 by the surface of the upper wall 111 of the storage portion, the lever member 35 is connected to the heat roller 3.
The pressing roller 31b can be pressed against the heat roller 31a using the pressing spring 36 on the outlet side. (See (a))

On the other hand, when the unit 10 is pulled out in this state, the free end of the operating lever 37 falls down to the paper discharge side surface 111a side of the upper wall of the storage section via the inclined step 112 in conjunction with the pulling-out operation. The lever member 35 is rotated counterclockwise by the urging force of the separation spring 38, and
When the jamming occurs in a state where one end of the recording material is nipped by the fixing roller 31 side, the jammed recording material becomes free with respect to the fixing roller 31 because The fixing roller 31 can be easily removed, and there is no danger of fire even when the fixing roller 31 is energized because the thermal contact of the jammed paper is released, and the toner is prevented from sticking to the fixing roller 31 side. I can do it. In this state, since the operation lever 37 has not been rotated to the position where the switch means 40 is turned off, the energization of the heat roller 31a is continued.

Therefore, by re-attaching the transport unit 10 after the jam clearance in this state, the pressing roller 31b is pressed against the heat roller 31a in the opposite direction to the above operation, and the heat roller 31a maintains the energized state. Therefore, the fixing operation can be promptly restarted.

Further, the operation lever 37 of the fixing unit 30 is in a free state as shown in FIG. 3B when the transport unit 10 is completely detached, and can be further rotated. By operating the switch means 40 at the rotation position, the heat roller 31 is moved.
By turning off the energization of a, the energization of the roller is prevented during actual maintenance, and safety is easily ensured.

[0030]

As described above, according to the present invention, it is possible to safely and reliably pull out the transport unit along the recording material transport direction even while the energized state of the fixing roller is maintained. Can be quickly resumed, and even when the fixing roller pair is left on the apparatus main body side, without increasing the burden on the operator,
It has various remarkable effects such as the ability to perform jam processing safely and easily.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an electrophotographic apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a relationship between a transport unit and a paper feed cassette incorporated in the apparatus.

FIGS. 3A and 3B are enlarged views showing the operation of a fixing unit and a transport unit, where FIG.
(B) shows a state in which the transport unit is being taken out.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Conveying unit 22 Engaging recess 30 Fixing unit 31 Fixing roller pair 34 Swinging mechanism 40 Switch means 113 Engagement projection

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-2-152836 (JP, A) JP-A-63-264771 (JP, A) JP-A-2-161473 (JP, A) JP-A-56 132352 (JP, A) Fully open 58-6757 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 21/16-21/18 G03G 15/00 550 G03G 15/00 510-534 G03G 15/20-15/20 302 G03G 21/00 370-520 G03G 21/14

Claims (2)

(57) [Claims] 1. A unit for forming at least a part of a recording material conveying path from a recording material feeding end to an entrance end of a thermal fixing unit having a pair of fixing rollers whose at least one side is a heating roller along a recording material conveying direction. comprising a conveying unit comprising, substantially perpendicular withdrawable constructed along the direction the photosensitive drum axis the conveying unit, energized and said fixing roller for instrumentation <br/> Chakuji is the heating roller of the transport unit to maintain the pressure contact state of pairs, said conveying unit to draw to a predetermined amount from the mounting position to release the pressure of the fixing roller pair while maintaining the energized state of the heating roller, the conveyance unit and the predetermined amount or more When pulled out
Electrophotographic apparatus, characterized in that has a structure which Setsuden the heating roller while releasing the pressure contact of the pair of fixing rollers. 2. A unit for at least a part of a recording material conveyance path extending from a recording material feeding end to an entrance end of a thermal fixing unit having a pair of fixing rollers whose at least one side is a heating roller along a recording material conveyance direction. comprising a conveying unit comprising,該搬a feeding unit provided stepwise drawer mechanism to locked temporary engagement at its intermediate position when the drawer along a direction substantially perpendicular to the photosensitive drum axis, when the transport unit drawer, the intermediate position state until the locking step of maintaining the energized state of the heating roller in
The fixing roller is released the pressure contact of the pair, Setsuden the heating roller while releasing the pressure contact of the pair of fixing rollers when further performing pulled out beyond the locking position of the transport unit at said intermediate position An electrophotographic apparatus, characterized in that the electrophotographic apparatus is configured to be operated.