JP3261869B2 - 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 having a curved sheet conveying path, and more particularly to an image forming apparatus in which a sheet is strongly pressed against a guide plate outside a curved portion of the sheet conveying path. The present invention relates to an image forming apparatus provided with a mechanism that can perform a guiding operation favorably.

[0002]

2. Description of the Related Art In an image forming apparatus such as an electrophotographic copying machine, a plurality of paper storage means such as a plurality of paper feed trays are arranged in a paper feed unit, and sheets having different sizes and paper qualities are placed in the paper feed trays. It is configured so that it can be stored and any paper can be sent out according to the size of the document. As a device to which a plurality of paper feed trays can be mounted as described above, for example, a device as disclosed in Japanese Patent Application Laid-Open No. 5-323719 is known. It is configured as shown in FIG. FIG. 7
The electronic copying machine as the image forming apparatus 1 shown in FIG. 1 is provided with a mechanism for writing an image using a digital system, and is configured as an automatic duplex copying machine.

In an image forming section disposed above the main body of the image forming apparatus, image information output from an image signal output device 6 is output from a writing device 7 to a photosensitive drum 2 as an image carrier. And a mechanism for forming a toner image using an electrophotographic method by scanning with a laser beam. Around the photosensitive drum 2, a charger, a developing device 3,
A transfer / peeling corotron 4, a cleaning device 5, and the like are arranged. Then, after the photosensitive drum is charged, an image is written to form an electrostatic latent image, and toner is supplied from a developing device to visualize the electrostatic latent image and transfer it to paper. And means for cleaning the toner and the like remaining on the surface of the photosensitive drum after the image is transferred by the cleaning device.

[0004] At an upstream portion of a transfer portion of the toner image from the photosensitive drum 2, an aligning portion 30 is provided at an end of the paper transport path 20.
And a plurality of paper feed trays 10 to 13 and a double-sided tray member 1 are arranged in the paper transport path 20 upstream of the alignment section.
4 are connected. Paper feeders 15 to 19 are arranged on each of the paper feed trays and the double-sided tray members, and the paper stored in each tray is sent out using the respective paper feeders, and the paper is fed into the paper transport path 20. In the embodiment, the conveying operation is performed in a state where the sheet is nipped by a plurality of conveying roller devices. Then, the paper conveyed in the paper conveyance path 20 is temporarily stopped by the aligning unit 30, sent to the image transfer unit in time with the toner image formed on the photosensitive drum, and sent to the photosensitive drum. Transfer of the formed toner image is performed.

The sheet on which the toner image has been transferred from the photosensitive drum 2 is introduced into the fixing device 9 via the conveying device 21 and is fixed there.
Discharge to 4. In the image forming apparatus, a return path 25 is connected via the switching gate 22 in the middle of the discharge path, and a mechanism for feeding the single-sided copy paper toward the double-sided tray member 14 via the return path 25 is provided. When the copy mode set in the image forming apparatus is set to the multiple copy creation mode, single-sided copy paper is guided from the return path 25 to the double-sided tray member 14 via the switching gate 26. Then, the single-sided copy sheet is accommodated in a double-sided tray member with the image side facing down, and another image is superimposed and transferred onto the image side of the single-sided copy sheet during the next copying operation.

In the return path 25, the double-sided tray member 14
A switching gate 26 and a reversing path 27 below the switching gate 26 are disposed at a position corresponding to the above. When the electronic copying machine is set to the double-sided copy mode, the paper as a one-sided copy is removed from the return path 25. It is sent to the reversing path 27. Then, the forward / reverse driving roller device 28 provided in the reversing path 27 is driven to rotate in the reverse direction, and the one-sided copy sheet is sent to the double-sided tray member 14 below the switching gate 26,
The paper is stored in an inverted state. Therefore, the inverted single-sided copy paper is in a state where the image side faces upward in the double-sided tray member 14, and the toner image is transferred to the back side of the single-sided copy paper sent from the double-sided tray member. , Can make double-sided copies.

On the side of the apparatus main body corresponding to the return path and the reversing path on the side of the discharge tray, an openable and closable side door member 35 is provided via a hinge 36 so as to be openable and closable. If a jam occurs in the conveyance path for conveying the single-sided copy paper, the jammed paper can be easily processed by opening the side door member. further,
An openable and closable cover member (not shown) is also provided on the other side of the apparatus main body so as to correspond to the paper transport path from the paper feed tray to perform operations such as paper jam processing in the paper transport path. It is easy to do.

[0008]

In the image forming apparatus having the above-described configuration, the paper transport speed between the paper transport paths is often different, and the paper is transported between transport roller devices having different transport speeds. When the paper is conveyed, the paper may be slackened or extra tension may be applied. For example, as shown in FIG.
7 guides the paper toward the conveyance path 40 of the double-sided tray member, while the speed of the forward / reverse drive roller device 28 disposed in the reversing path 27 is high, In the delivery roller device 43 arranged at
Set to a relatively low speed. In addition, the conventional example shown below,
In the embodiment of the present invention, a sheet feeding section from each device such as a sheet feeding tray and a double-sided tray member, and a sheet conveying path 2
An example in which a paper path is directly connected without disposing a sheet feeding unit at a connection portion with 0 will be described.

In the conventional example, the transport roller device 55 provided in the paper feed path 40 is compared with the transport speed of the feed roller device 43 disposed in the feed section of the transport path 40.
In, the transport speed is set relatively low. Therefore, the transport path 40 of the double-sided tray member 14 as described above is used.
On the other hand, in the curved path 50 in the portion where the sheet is fed and the portion where the sheet is sent out toward the transport path, the sheet is slackened. Then, there is a problem that the slack portion of the sheet slides strongly on the guide plate forming the curved path, and there is a problem that the sheet hits the guide plate to generate noise.

The curved path 50 shown in FIG. 8 has, for example, a configuration as shown in FIG. 9, and is provided at a delivery roller device 4 disposed downstream of the conveying path 40 of the double-sided tray member.
3 is configured as shown in FIG. In the example shown in FIG. 9, the curved path 50 disposed between the conveyance path 40 of the double-sided tray member and the paper conveyance path 20 of the apparatus main body is constituted by guide plates 51 and 52 for guiding the front and back of the paper. And
The paper can be guided toward the paper transport path 20.
Further, as shown in FIG. 10, a feed roller device 43 for feeding a sheet from the transport path 40 toward the curved path 50 includes a drive roller member and a pinch roller member 48, and a drive shaft 45 of the drive roller member. Are mounted at predetermined intervals, and rollers 48a, 48b of a pinch roller member are provided corresponding to the rollers 45a, 45b.

A pulley 46 is arranged at an end of a drive shaft 45 of the drive roller member, and a drive belt 47 transmits a drive force. Further, the roller of the pinch roller member is mounted via means for supporting and urging such as a leaf spring so that a pressing action can be performed on the driving roller member. In the feed roller device 43 configured as described above, the paper P is set to have a corrugation state (corrugation) in the width direction between the rollers, and the paper P is directed toward the downstream transport roller device 55 in a state of strengthening the stiffness of the paper. By feeding the paper, the paper does not buckle inside the curved path 50.

However, as shown in FIGS. 9 and 10, even when using a method of forming corrugations on paper conveyed in a curved path, if the curved path is formed with a very small radius, There is a problem that the corrugations in the width direction of the paper are crushed and abnormal noise is generated. The paper fed by the feed roller device 43 from the conveyance path of the double-sided tray member slides strongly on a guide plate below the curved path when a loop is formed on the curved path, or the paper is There remains a problem that the guide plate is strongly hit. Therefore, in order to solve the above-described problem, for example, as shown in Japanese Utility Model Application Laid-Open No. 61-181046, a guide plate arranged in a curved sheet conveyance path is swung according to a sheet loop. It is also conceivable to make it possible. However, as shown in FIG. 7, it is not possible to dispose a mechanism that swings the guide plate largely in a narrow place, such as a connection portion between a paper feed path such as a paper feed tray and a paper transport path of the main body. At present, it is very difficult to develop a device that can guide a sheet on a curved road satisfactorily and can prevent generation of abnormal noise and the like.

[0013]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the conventional paper transport apparatus.
It is an object of the present invention to provide an apparatus capable of preventing a paper sheet from hitting a guide plate strongly and generating noise.

[0014]

SUMMARY OF THE INVENTION The present invention relates to an image forming apparatus having a curved sheet conveying path for conveying a sheet.
The invention according to claim 1 of the present invention comprises a movable chute member that can swing outside the curved portion of the paper transport path, and a sheet-like guide member is disposed on the movable chute member so as to protrude from the tip thereof. It is characterized by having done. Therefore, when a loop is formed on the sheet conveyed in the curved path, the sheet slides along the sheet member while pressing and swinging the swing guide plate, so that the sheet strongly strikes the guide plate. Is prevented. Further, the swing guide plate for guiding the sheet automatically returns to the original position when the pressing action of the sheet is released, so that the sheet can be guided in a satisfactory state.

According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, a first transport roller device for transporting a sheet provided upstream of the curved sheet transport path, and the curved sheet A second transport roller device configured to transport a sheet provided downstream of the transport path; and a sheet detection unit configured to detect a sheet provided downstream of the second transport roller device; It is characterized in that the transport roller device is configured to be capable of separating from and approaching the sheet, and the first transport roller device is separated from the sheet based on the detection information of the sheet detection unit. Therefore, noise can be prevented from occurring when the paper is transported between the two transport paths.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of an image forming apparatus according to the present invention will be described with reference to the illustrated example. The example shown in FIG. 1 shows a case where, as shown in FIG. 7, for example, means for sending out the sheet sent from the double-sided tray member toward the sheet conveying path of the apparatus main body is configured. For example, the double-sided tray member 1
The curved guide part 60 is arranged at the connection part with the fourth. The arrangement of the upper guide plate 51 on the curved guide portion 60 is the same as that of the conventional device, but is provided with a combination of two swing guide plates 62 and 65 instead of the lower guide plate. Further, the transport roller device disposed in the upstream and downstream portions of the curved path is configured such that the feed roller device 43 on the transport path 40 side transports the sheet at high speed, and the transport roller device 55 disposed in the sheet transport path 20 has a relatively low speed. To perform a sheet transport operation. Then, on the curved path, when the sheet is conveyed by the conveying roller devices at the upstream and downstream portions, a loop is automatically formed on the sheet.

As shown in FIG. 2, the two swing guide plates are provided with a comb-like portion 63 at the distal end of a plate member body supported by a support shaft 64, and are provided so as to be swingable. The spring 68 urges the swing guide plate 62 clockwise. The swing guide plate 65 combined with the swing guide plate 62 is provided with a comb-like portion at an end of the plate member, and is swingably supported via a support shaft 67. To be urged counterclockwise. Then, the two swing guide plates 62,
Numeral 65 is configured to be slidable with each other by combining the concave and convex portions arranged at the leading end thereof, and to be capable of guiding the curving of the sheet.

As described above, the two rocking guide plates 62 and 65 are combined via the comb-shaped portion to form a sheet guide surface on the plastic sheet 61.
The tip of the upstream portion of the sheet 61 is attached to the surface of the swing guide plate 65 via an adhesive portion 61a. Then, when the paper passes through the curved guide section,
When the sheet 61 slides on the sheet, it acts as a guide,
When a loop is formed on the paper, set the pressing force of the loop to 2
One rocking guide plate is received. Therefore, as shown in FIG. 1, as the sheet loop becomes larger, the swing guide plates 62 and 65 are swung through the respective support shafts, so that the swing guide plates 62 and 65 can exert the action of releasing the pressure of the sheet. To Further, when a paper loop is formed in the curved guide portion, the loop becomes gradually larger as the paper transport action is performed, so that the swing guide plate is swung by the pressure of the loop. The movement prevents the loop portion of the sheet from suddenly hitting the swing guide plate.

In the example shown in FIG. 1, the transport path 40 is configured to be connected to the end of the paper transport path 20 of the apparatus main body. It is also possible to configure means for connecting the transport path and guiding the paper. In the example shown in FIG. 3, a curved guide path from the transport path 40 is connected to a part of the paper transport path 20, and one upper guide plate 5 of the paper transport path 20 is connected.
1 is connected to the upper guide plate of the transport path 40, and the curved guide portion 60 is provided with a guide means combining two swing guide plates 62 and 65 and a sheet 61. The curved guide section 60 allows paper conveyed from the lower portion of the paper conveyance path to pass at the junction of the curved path,
A unit that guides the sheet to the sheet conveyance path via the curved guide section 60 of the curved path also for the sheet sent out from the conveyance path 40 is configured.

When a loop occurs in the sheet due to a difference in the sheet conveying speed between the feed roller unit 43 disposed in the conveying path 40 and the conveying roller unit 55 in the sheet conveying path, the sheet is turned into a sheet. By pressing the swing guide plates 62 and 65 via the 61 and the respective swing guide plates are swung via the support shafts, the pressing force of the paper loop can be released. Further, as shown in FIG. 2, a biasing means using a spring is disposed on the two swing guide plates to prevent the paper loop from being strongly hit against the curved guide portion. Therefore, it is possible to prevent the generation of abnormal noise during the sheet conveying operation. Also, in the apparatus shown in FIG. 3, the leading end of the paper is prevented from being caught on the comb-like portion of the swing guide plate by the paper sliding on the sheet.

[0021]

Embodiment 2 In addition to forming the above-described paper guide means, in the present invention, a transport roller device disposed on a curved path causes the transport roller device in the downstream portion to bear the transport operation of the paper. Accordingly, it is possible to configure a transporting unit that does not form an extra loop. In the example shown in FIG. 4, as in the example shown in FIG. 3, a curved path 50 from the conveyance path of the double-sided tray member is connected to the paper conveyance path 20 of the apparatus main body. Curved road 5
Feed roller device 70 with a high conveying speed upstream of
The transport roller device 55 in the downstream portion is configured as a roller having a low speed. Further, sensors S and S1 for detecting a sheet are disposed at an end of the conveyance path and a position near the conveyance roller device of the paper conveyance path, and information of the sheet obtained by the sensor is used. A means for controlling the nip of the sheet in the feed roller device 70 is provided. Further, a swing guide plate 65 is disposed at a portion corresponding to the lower guide plate of the curved path 50 via a support shaft 67, and a sheet 61 is disposed on the surface of the swing guide plate, and It constitutes means for providing guidance. In the present invention, the swing guide plate 65 and the sheet 61 may be provided, and the lower guide plate may be arranged in a fixed state.

In the example shown in FIG. 4, the delivery roller device 70 disposed at the end of the transport path 40 is configured by combining a drive roller member 71 and a pinch roller member 75, and nips the paper between the two rollers. In such a state, the transfer operation is performed. The pinch roller member 75
The roller is supported by a member such as a leaf spring 76. The leaf spring 76 is provided on a support shaft 77, and the support shaft 77 is swung to separate the pinch roller member 75 from the drive roller member. Perform the action of contact. Further, when the rear arm 78 is disposed with respect to the support shaft 77 and a stopper 79 is provided corresponding to the rear arm, the support shaft 77 is swung to separate the pinch roller member 75 from the drive roller member 71. Furthermore, means for restricting the swing range of the support shaft is configured.

In order to swing the pinch roller member of the delivery roller device 70, for example, a device as shown in FIG. 5 can be constructed. In the example shown in FIG. 5, the drive transmission device 80 is disposed with respect to the drive shaft 72 of the drive roller member, and the drive unit (not shown) drives the drive pulley provided on the drive shaft via the drive belt 81. A force is transmitted to drive the drive roller member. Further, a gear device 83 is arranged between the drive shaft 72 and the support shaft 77 of the pinch roller member, and constitutes means for transmitting the rotation of the drive shaft 72 for driving the drive roller member to the support shaft 77. . Further, the support shaft 77 is provided with an electromagnetic clutch 85 and a torque control means 86 such as a torque limiter, and only when the electromagnetic clutch 85 is connected, the support shaft 77 is rotated counterclockwise in FIG. Means. The spindle 77 has a torque control unit 86
In the state where the rear arm 78 is locked by the stopper 79, the torque control means 86 slides, so that the pinch roller member is separated from the drive roller member without rotating the support shaft any more. Be able to hold in state.

When the nip release means shown in FIG. 5 is provided for the delivery roller device 70 as shown in FIG. 4, the leading end of the paper passes through the delivery roller device,
When the detection is performed by the sensor S provided in the transport roller device on the paper transport path, the electromagnetic clutch is connected and the support shaft 77 of the pinch roller member rotates according to the detection information of the sensor S. When the rear arm 78 is swung until it comes into contact with the stopper 79, the torque control means 86 slips, so that the rotation of the support shaft 77 is stopped and the state in which the nip of the feed roller device 70 is released is maintained. The operation of conveying the sheet is performed only by the conveying roller device 55 in the downstream portion.

The transport operation for the sheet is performed as shown in the timing chart of FIG.
When the sensor S disposed on the paper transport path detects the leading end of the paper after the sensor S1 disposed on the transport path detects the paper, the control device outputs a command to energize the electromagnetic clutch, and the electromagnetic clutch is connected. Thereby, the support shaft is rotated. When the sensor S1 at the upstream portion outputs information indicating the detection of the trailing end of the sheet, the power supply to the electromagnetic clutch is stopped, the swing operation on the support shaft is interrupted, and the pinch roller member of the feed roller device is stopped. Is returned to a state of being pressed against the drive roller member.

Therefore, by disposing the transport roller device and the feed roller device as shown in FIG. 4, the state in which the sheet is transported at different speeds by the two transport roller devices on the curved path is eliminated. Control can be performed such that a large loop is not formed on the sheet. Therefore, when means for controlling the nip of the transport roller device is provided, it is possible to prevent the paper loop from hitting the lower guide plate and generating noise. In addition, as a sheet | seat arrange | positioned in a curved path | route of this invention, a thin film, such as a polyethylene terephthalate, or another plastic film-shaped member can be used. When the film member is used, the sheet conveyed in the ascending direction in the sheet conveyance path with the leading end protruding into the sheet conveyance path can pass in a state in which the film member is pushed away, so that the sheet There is no obstacle to the paper conveyed in the conveyance path.

Furthermore, the swing guide plate disposed on the curved path can be made of a relatively lightweight plastic material. If a swing guide plate that easily swings while being pressed by paper is used, The swing guide plate can be easily swung by the pressing force of the sheet loop. In the embodiment of the present invention, the swing guide plate is disposed on the curved path that guides the sheet from the double-sided tray member toward the sheet transport path, and the nip of the transport roller device is released. Although the case has been described, as a curved path of the present invention,
It can be arranged at an arbitrary position of a curved portion of a sheet transport path of the image forming apparatus, or at an arbitrary position of a right-angled connection portion, and can be provided with a sheet feeding path from an arbitrary sheet feeding tray of a sheet feeding section, a double-sided tray member, The present invention can be applied to a connection portion of a return path and the like.

[0028]

Since the apparatus of the present invention is constructed as described above, the paper slides along the sheet while pressing and swinging the swing guide plate. Strong hitting is prevented, and generation of abnormal noise and the like can be prevented. Further, the swing guide plate for guiding the sheet automatically returns to the original position when the pressing action of the sheet is released, so that the sheet can be guided in a satisfactory state.

Further, in the transport roller device disposed on the curved path, a nip release mechanism is disposed with respect to the transport roller device in the upstream portion, so that the sheet is nipped by the transport roller device in the paper transport path of the apparatus body. In the state of being transported, the nip of the upstream feed roller device can be released,
When the paper is transported between the two transport roller devices, the paper does not hit the guide plate strongly, and the generation of noise can be prevented.

[Brief description of the drawings]

FIG. 1 is a side view illustrating a configuration of a sheet conveying device of the present invention.

FIG. 2 is a perspective view of a swing guide plate disposed on a curved guide portion.

FIG. 3 is an explanatory view of another embodiment of the present invention.

FIG. 4 is an explanatory diagram of another embodiment of the present invention.

FIG. 5 is an explanatory view of a nip releasing means provided in the apparatus of FIG. 4;

FIG. 6 is a timing chart showing a nip release operation in the apparatus shown in FIG. 4;

FIG. 7 is an explanatory diagram illustrating a configuration of a general image forming apparatus.

FIG. 8 is an explanatory diagram illustrating a configuration of a conveyance path of a double-sided tray member.

FIG. 9 is an explanatory diagram of a curved path of a conventional paper transport path.

FIG. 10 is an explanatory diagram showing a configuration of a conventional delivery roller device.

[Explanation of symbols]

1 image forming apparatus, 14 double-sided tray member, 2
0 paper transport path, 40 transport path, 43 feed roller device, 48 pinch roller member, 50
Curved path, 55 transport roller device, 60 curved guide portion, 61 sheets, 62, 65 swing guide plate, 70 feed roller device, 80 drive transmission device, 85 electromagnetic clutch, 86 torque control means.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B65H 5/36 G03G 15/00 510

Claims (2)

(57) [Claims] 1. An image forming apparatus having a curved sheet conveying path for conveying a sheet, comprising: a movable chute member swingable outside a curved portion of the sheet conveying path; An image forming apparatus, wherein a sheet-like guide member is disposed so as to protrude from the leading end. 2. The image forming apparatus according to claim 1, wherein: a first transport roller device configured to transport a sheet provided upstream of the curved sheet transport path; and a downstream section of the curved sheet transport path. A second transport roller device for transporting the paper provided in the first transport roller device; and a paper detection unit configured to detect the paper provided downstream of the second transport roller device. An image forming apparatus, wherein the first transport roller device is separated from a sheet based on detection information of the sheet detecting means.