JP3279440B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a printer and a facsimile.

[0002]

2. Description of the Related Art FIG. 6 shows an entire configuration of a conventional image forming apparatus (copier).

In the present image forming apparatus, an image of a document (not shown) set on a platen glass 2 of an image forming apparatus main body 1 is scanned by an optical system 3 on a photosensitive drum 4 rotating in the direction of an arrow. Projected to This allows
An electrostatic latent image is sequentially formed on the photosensitive drum 4.

[0004] The electrostatic latent image formed on the photosensitive drum 4 is visualized by toner supplied from a developing device 5, and the toner image on the photosensitive drum 4 is sequentially transferred to a transfer charger 6. To the transfer section.

On the other hand, a paper feed unit (paper feed cassette) 7 or 8
, The sheet material S is fed. When the fed sheet material S collides with the nip of the registration roller pair 9 which is not rotating, a predetermined loop is formed to correct the skew state.

Thereafter, the sheet material S which has reached the registration roller pair 9 is conveyed to the transfer section by the registration roller pair 9 which starts rotating at the timing of adjusting the position of the sheet material to the toner image on the photosensitive drum 4, and is transferred here. And the photosensitive drum 4
The upper toner image is sequentially transferred to the sheet surface by the transfer charger 6.

The sheet material S on which the transfer of the toner image has been completed in the transfer section is conveyed by a conveying belt 10 to a fixing device 11, where the toner image is fixed on the sheet surface.

The sheet material S that has been subjected to the toner image fixing process by the fixing device 11 is sent to a paper discharge path 13 by a pair of transport rollers 12 in a one-sided copying mode, and is sent by a pair of paper discharge rollers 15 to the image forming apparatus main body 1. The paper is discharged onto an external paper discharge tray (not shown). In this case, the flapper 14 has opened the discharge path 13.

The sheet material S which has been subjected to the fixing process of the toner image by the fixing device 11 is in a double-sided copy mode.
The sheet is conveyed to the reversing path 16 by the pair of conveying rollers 12, and is reversed on the reversing path 16 and discharged onto the intermediate tray 18 in the duplex unit 17. In this case, flapper 1
4 opens the reversing path 16.

The plurality of sheet materials S stacked on the intermediate tray 18 are sequentially fed out from the lowest sheet material by the paper feed roller 19 in order to transfer the toner image to the second surface, and the separation roller pair is used. The sheet is separated one by one by 20 and is again conveyed to the registration roller pair 9 whose rotation is stopped by the large-diameter conveying roller 21 and the roller 22.

The sheet material S which has reached the registration roller pair 9
After the transfer and fixing of the toner image are performed in the same manner as in the case of the first surface described above, the toner image is discharged onto a discharge tray outside the image forming apparatus main body 1 by the discharge roller pair 15.

In this image forming apparatus, as shown in FIG. 7, a conveying roller 21, a roller 22 and a registration roller pair 9 are provided.
Between the first and second registration guide members 23, 2
4 is provided, and a transfer guide path 28 including plate-shaped first and second transfer guide members 26 and 27 is provided between the registration roller pair 9 and the transfer unit.

Thus, the conveying roller 21 and the roller 22
Is transported to the nip of the registration roller pair 9 by the registration guide path 25. At this time, the first registration guide member 23 guides the upper surface side of the sheet material S, and the second registration guide member 24
Guide the lower side of the.

The sheet material S conveyed by the registration roller pair 9 is guided to a transfer section by a transfer guide path 28. At this time, the first transfer guide member 26 guides the upper surface side of the sheet material S, and the second transfer guide member 27 guides the lower surface side of the sheet material S.

In the present image forming apparatus, as a countermeasure for a jam (paper jam) occurring in the sheet material S moving in the registration guide path 25 and the transfer guide path 28, the registration guide path 25 and the transfer Each guide member 2 for guiding the lower surface of the sheet material in the guide path 28
The sheets 4 and 27 are opened downward so that the jammed sheet material can be removed from the paths 25 and 28.

For this purpose, the second transfer guide member 27 and the lower roller (driven roller) 9B of the registration roller pair 9 are attached to the second registration guide member 24, and the second registration guide member 27 is transported. The roller 21 is rotatably attached to a roller shaft 21A.
Generally, the second transfer guide member 27 and the second registration guide member 24 are integrally formed by a single metal plate or the like.

The guide members 23 and 26 for guiding the upper surface of the sheet material in the registration guide path 25 and the transfer guide path 28, and the upper roller (drive roller) 9A of the registration roller pair 9 are respectively connected to the image forming apparatus main body 1. The position is fixed.

The second registration guide member 24 and the second transfer guide member 27 are normally set at the positions indicated by imaginary lines in FIG. 7, and are respectively set by the first registration guide member 23 and the first transfer guide member 26. Guide path 25,
28 are formed.

The second registration guide member 24 and the second
The set position of the transfer guide member 27 is also a position where the lower roller 9B of the registration roller pair 9 contacts the upper roller 9A. The leading end (downstream end) 27A of the second transfer guide member 27 at the set position is separated from the outer peripheral surface 4A of the photosensitive drum 4 by a minute distance (C) that does not contact the toner image. are doing.

As described above, the second registration guide member 24 and the transfer guide member 27 set at the positions indicated by the imaginary lines are formed by the second registration guide member 24 and the roller shaft 2.
By pivoting about 1A, it is possible to open downward as shown by the solid line.

In the present image forming apparatus, when the double-sided unit (drawer member) 17 is pulled out to the front side of the image forming apparatus main body 1, the second registration guide member 24 and the second transfer guide member 27 are interlocked with this operation. It is designed to open downward.

That is, the double-sided unit 17 pushed and stored in the image forming apparatus main body 1 is rotatable up and down around the roller shaft 29A of the downstream roller 29 of the conveyor belt 10. Transport unit (equipped with transport belt 10, transfer charger 6, etc.)
30 is supported at a predetermined set position. In this case, the duplex unit 17 pushes the upstream side of the transport unit 30 to a predetermined position via the roller 31.

The transport unit 30 at the set position
Supports the second registration guide member 24 and the second transfer guide member 27 at a predetermined set position. in this case,
The lever 32 on the upstream side of the transport unit 17 is
The second registration guide member 24 is lifted up to a predetermined position via the.

FIG. 6 shows the double-sided unit 17, the transport unit 30, and the second registration guide member 24 as described above.
And a state where the second transfer guide member 27 is at the set position.

When the duplex unit 17 is pulled out to the front side of the image forming apparatus main body 1, the duplex unit 17 loses the function of supporting the transport unit 30. Therefore, the duplex unit 17
Transport unit 30 pushed up and supported by
Is rotated downward about the roller shaft 29A. As a result, the transport unit 30 also loses the function of supporting the registration guide member 23. Therefore, the transport unit 30
The second registration guide member 24 that has been lifted and supported by the rotation of the second registration guide member 24 rotates downward about the roller shaft 21A. As a result, the second registration guide member 24
And the second transfer guide member 27 opens downward.

FIG. 7 shows the lowering position of the transport unit 30 when the duplex unit 17 is pulled out to the maximum, and the lowering positions of the second registration guide member 24 and the second transfer guide member 27. The second registration guide member 24 rotates downward around the roller shaft 21 </ b> A to a position where the leading end 27 </ b> A of the second transfer guide member 27 contacts the upper surface of the transport unit 30 by its own weight including the second transfer guide member 27. .

As described above, when the second registration guide member 24 and the second transfer guide member 27 are opened downward, the sheet material JS that has been jammed in the registration guide path 25 or the transfer guide path 28 is removed. it can.

After the jam processing, when the duplex unit 17 is pushed into the image forming apparatus main body 1, the transport unit 30 is pushed up to the set position by the duplex unit 17, and the second registration guide member 24 is moved by the transport unit 30.
Can be lifted to the set position.

[0029]

However, as in the conventional image forming apparatus, the second registration guide member 24 and the second transfer guide member 27 are integrally formed by a single metal plate or the like. In the case where the second transfer guide member 27 is fixedly attached to the second registration guide member 24, the tip 2 of the second transfer guide member 27
Since the downward rotation of the second registration guide member 24 is restricted at the time the 7A comes into contact with the upper surface of the transport unit 30, the second registration guide member 24 and the second transfer guide member 27 may be widely opened. Therefore, it was necessary to perform the jam clearance in a narrow space with poor workability.

In the case where the second transfer guide member 27 corresponding to the outer peripheral surface 4A of the photosensitive drum 4 is used over the entire width as in the above-described conventional image forming apparatus, it is set at a predetermined position. Tip 27A of second transfer guide member 27
Must be located at a small distance (C) between the outer peripheral surface 4A of the photosensitive drum 4 and the outer peripheral surface 4A so as not to contact the toner image. A step of adjusting a minute distance (C) between the tip 27A of the guide member 27 and the outer peripheral surface 4A of the photosensitive drum 4 is required, which causes an increase in cost.

Therefore, the present invention has been made in view of the above circumstances, and (1) a jam generated in a resist guide path or a transfer guide path can be easily processed by forming a wide space. (2) It is an object of the present invention to provide an image forming apparatus in which it is not necessary to adjust a distance between a tip of a second transfer guide member and an outer peripheral surface of a photosensitive drum.

[0032]

According to the present invention, first and second registration guide members for guiding a fed sheet material to a pair of registration rollers by guiding the upper and lower surfaces thereof to a pair of registration rollers are conveyed by the pair of registration rollers. A first and a second transfer guide member for guiding the sheet material to the transfer section by guiding the upper and lower surfaces thereof, and a roller on the side of the registration roller pair that contacts the lower surface of the sheet material and the second transfer guide member. A transfer guide member is integrally attached to the second resist guide member, and
The present invention relates to an image forming apparatus in which the second registration guide member is rotatable about a support shaft in a direction in which the respective rollers of the pair of registration rollers contact and separate.

According to the present invention, in order to achieve the above objects (1) and (2), each roller of the pair of registration rollers is moved toward and away from the second transfer guide member with respect to the second registration guide member. It is mounted so that it can be bent in the direction in which it moves.

Further, the second transfer guide member guides the sheet material conveyed by the registration roller pair to a transfer portion between the photosensitive drum and the transfer charger.

Further, when the second registration guide member rotates about the support shaft and the respective rollers of the pair of registration rollers come into contact with each other, the downstream end of the second transfer guide member is connected to the drum of the photosensitive drum. It is characterized in that it comes into contact with the flange.

[0036]

According to the present invention having the above-described structure, when the second registration guide member rotates about the support shaft in the opening direction,
Even if the second transfer guide member is prevented from rotating, the second registration guide member bends the second transfer guide member to rotate further in the opening direction. Therefore, the rotation angle of the second registration guide member is greatly increased.

As a result, the space between the second registration guide member and the first registration guide member and the space between the second transfer guide member and the first transfer guide member are widened, and the jammed sheet material can be easily removed. You will be able to remove it.

When the second transfer guide member is at the set position, the tip of the second transfer guide member is in contact with the drum flange of the photosensitive drum. The distance is set so as not to contact the upper toner image.

Thus, the step of adjusting the minute distance between the end of the second transfer guide member and the outer peripheral surface of the photosensitive drum becomes unnecessary, and the cost can be reduced accordingly.

[0040]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration of a main part of an image forming apparatus (copier) according to an embodiment of the present invention.

In the present image forming apparatus, the configuration of a portion (not shown) is the same as that of the conventional image forming apparatus (FIG. 6).

Also, the members and the like in FIG. 1 which are the same as those in the above-described conventional image forming apparatus are denoted by the same reference numerals, and descriptions of those which do not change in structure and function are omitted. .

In the present image forming apparatus, the second transfer guide member 27 is attached to the second registration guide member 24 so that the second transfer guide member 27 can be bent in the vertical direction. That is, the second transfer guide member 27 has its base end (upstream end) 2
By rotatably fitting the roller 7B to the roller shaft 35 of the lower roller 9B, it is possible to bend up and down with respect to the second registration guide member 24.

As described above, the second registration guide member 24
The second transfer guide member 27, which is attached so as to be able to bend in the up and down directions, is urged upward by an urging spring (torsion spring) 36 mounted on a roller shaft 35.

FIG. 1 shows a state where the second registration guide member 24 and the second transfer guide member 27 are at the set position. In this state, the leading end 27A of the second transfer guide member 27 is urged by the urging spring 36 to contact the left and right drum flanges 4B and 4C of the photosensitive drum 4 with a predetermined pressure.

FIG. 2 shows the relationship between the photosensitive drum 4 and the second transfer guide member 27. The total width B1 of the second transfer guide member 27 and the total width B2 of the photosensitive drum 4 are the same. Therefore, the second transfer guide member 27 is connected to the left and right side edges 2.
The portions 7B and 27C come into contact with the left and right drum flanges 4B and 4C of the photosensitive drum 4 as described above.

As shown in FIG. 3, on the upper surface of the second transfer guide member 27, a plurality of ridges 37 for reducing friction are formed integrally at predetermined intervals. I have. Since the sheet material S moving on the second transfer guide member 27 moves while being in linear contact on each of the ridges 37, the sliding friction is significantly reduced.

In the present image forming apparatus, as shown in FIG. 4, when a jam occurs between the transfer guide path 28 and the registration guide path 25, similar to the conventional image forming apparatus described above, The duplex unit 17 is pulled out to the front side of the image forming apparatus main body 1, the transport unit 30 is rotated downward around the roller shaft 29A, and the second registration guide member 24 is rotated downward around the roller shaft 21A. .

FIG. 5 shows a state in which the double-sided unit 17 is pulled out from the image forming apparatus main body 1 to the maximum.

When the transport unit 30 rotates downward, the second registration guide member 24 also rotates downward by its own weight including the second transfer guide member 27 so as to follow the rotation. Then, the transport unit 30 is moved to a predetermined position (position shown).
When the first transfer guide member 27 is
7A abuts on the upper surface of the transport unit 30 and is prevented from rotating. However, the second registration guide member 24 rotates further downward by refracting the second transfer guide member 27 from the roller shaft 35 by its own weight. When the lower roller 9B abuts on the transport unit 30 as shown in the figure, the rotation is stopped.

As described above, the second registration guide member 24
Can bend the second transfer guide member 27 and continue rotating downward, so that a large space for jam processing is obtained as shown in the figure, and the jammed sheet material JS is easily removed. be able to.

[0052]

As described above, in the image forming apparatus of the present invention, the second transfer guide member is mounted so as to be refractible with respect to the second registration guide member. A wide space can be formed, and jam processing can be easily performed.

Further, since the tip of the second transfer guide member is brought into contact with the drum flange of the photosensitive drum,
There is no need to adjust the minute distance between the tip of the transfer guide member and the outer peripheral surface of the photosensitive drum, and the cost can be reduced accordingly.

[Brief description of the drawings]

FIG. 1 is an image forming apparatus (copier) according to an embodiment of the present invention.
FIG. 2 is a longitudinal sectional side view showing a configuration of a main part of FIG.

FIG. 2 is a perspective view illustrating a relationship between a photosensitive drum and a second transfer guide member provided in the image forming apparatus.

FIG. 3 is a perspective view showing a configuration of a second transfer guide member.

FIG. 4 is a vertical cross-sectional side view showing a state in which a jam occurs across a transfer guide path and a registration guide path of the image forming apparatus.

FIG. 5 is a longitudinal sectional side view showing a state in which a second registration guide member and a second transfer guide member are opened in order to treat a jam generated over the transfer guide path and the registration guide path.

FIG. 6 is a vertical sectional side view showing the entire configuration of a conventional image forming apparatus (copier).

FIG. 7 is a longitudinal sectional side view showing a state where a second registration guide member and a second transfer guide member in the image forming apparatus are opened for jam processing.

[Explanation of symbols]

 Reference Signs List 4 photosensitive drum 4B, 4C drum flange 6 transfer charger 9 registration roller pair 9A upper roller 9B lower roller 17 double-sided unit (drawing member) 21A roller shaft (support shaft) 23 first registration guide member 24 second registration guide member 26 First transfer guide member 27 Second transfer guide member 27A Tip (downstream end) 30 Transport unit (lifting member) 37 Friction reducing ridge (friction reducing means) S Sheet material

Claims (6)

(57) [Claims] 1. A first and a second registration guide member for guiding a fed sheet material on the upper and lower surfaces thereof to a registration roller pair, and a sheet material conveyed by the registration roller pair on the upper and lower surfaces thereof. First and second transfer guide members for guiding and leading to the transfer portion, and wherein the roller on the side of the registration roller pair that contacts the lower surface of the sheet material and the second transfer guide member are the second registration guide member. An image forming apparatus which is integrally attached to a guide member, and wherein the second registration guide member is rotatable about a support shaft in a direction in which the respective rollers of the pair of registration rollers contact and separate. An image forming method, wherein the second transfer guide member is attached to the second registration guide member such that the second transfer guide member can be bent in a direction in which each roller of the pair of registration rollers comes into contact with or separates from the second registration guide member. Location. 2. The image forming apparatus according to claim 1, wherein the second transfer guide member guides the sheet material conveyed by the pair of registration rollers to a transfer portion between a photosensitive drum and a transfer charger. 3. When the second registration guide member rotates about the support shaft and the rollers of the registration roller pair come into contact with each other, the downstream end of the second transfer guide member is connected to the drum of the photosensitive drum. 3. The image forming apparatus according to claim 2, wherein the image forming apparatus contacts the flange. 4. The second transfer guide member is urged in the direction of the photosensitive drum by an urging spring, and a downstream end of the second transfer guide member is biased by the urging force of the urging spring. The image forming apparatus according to claim 3, wherein the image forming apparatus contacts the drum flange at a predetermined pressure. 5. When the second registration guide member is lifted by a lifting member, the second registration guide member rotates about the support shaft in a direction in which the respective rollers of the pair of registration rollers come into contact with each other, and the second registration guide member is 2. The image forming apparatus according to claim 1, wherein when the lifting state by the lifting member is released, each roller of the pair of registration rollers rotates about the support shaft in a direction in which the rollers separate. 3. 6. The lifting member releases the lifting state of the second registration guide member in conjunction with the operation of pulling out the pull-out member from the inside of the image forming apparatus main body, and the lifting member removes the pull-out member from the image forming apparatus. 6. The image forming apparatus according to claim 5, wherein the second registration guide member is lifted in conjunction with an operation of pushing the second registration guide member into the apparatus main body.