JPH0286522A - Sheet conveyance device - Google Patents

Abstract

PURPOSE:To facilitate a jam processing in a sheet carrying device for copying machines by providing a guide plate continuously to one of a pair of resist rollers, rotating the guide plate with a supporting point part as the center, and releasing the pressure between the rollers. CONSTITUTION:In a pair of rollers 1 in which a roller 1b is energized and elastically touched to a roller 1a, a guide plate 2 for leading sheets is disposed continuously to the roller 1b. Supporting point parts 1c, 5 having supporting point axial lines in the direction crossing at a right angle to the sheet carrying direction are formed in positions of the guide plate 2 closed to the roller pair 1, so that the roller 1b is separated from the roller 1a based on the rotation of the guide plate 2 with the supporting point parts 1c, 5 as the center. Thus, when a trouble as paper clogging is caused in the roller pair 1, the guide plate 2 is rotated with the supporting part 5 or 6 as the center to separate the roller 1b from the roller 1a, and the jam processing can be easily conducted.

Description

Detailed Description of the Invention 1゜3゜(a) Industrial Application Field The present invention is an image forming apparatus that forms an image on a sheet, such as a copying machine or a laser beam printer. The present invention relates to a sheet conveyance device that conveys a sheet, and more particularly to a sheet conveyance device that can release pressure between a pair of rollers.

(b) In addition to the conventional technology S, a sheet conveying device for a copying machine equipped with a sheet re-conveying path used when performing double-sided continuous copying and multiple copying, for example, is disclosed in Japanese Patent Laid-Open No. 5695264. As shown, a pair of discharge rollers for discharging sheets copied in an image forming section onto a bin tray are configured to be reversible in the forward and reverse directions.
Furthermore, an apparatus has been devised in which a sheet re-conveying path is formed in front of the upstream side of the discharge roller pair to convey the copied sheet again to the image forming section. In order to embody the sheet conveying device, a pair of registration rollers for correcting the tank position of the sheet 1- is disposed on the sheet re-conveying path so as to be movable in a direction perpendicular to the sheet conveying direction, and A sheet trailing edge detection sensor that detects the trailing edge of the sheet conveyed by the roller pair is provided near the discharge roller pair, and a flapper that guides the sheet conveyed from both image forming sections to the discharge roller pair or the sheet re-disposal path. need to be placed.

When the double-sided copying mode of the copying machine is selected, the sheet copied on the front side in the image forming unit is conveyed onto the bin tray by the forward rotation of a pair of ejection rollers, and the trailing edge of the sheet is detected. When detected by the sensor, the discharge roller pair is reversely rotated, and the sheet is guided by the flapper and conveyed to the sheet re-conveyance path. Furthermore, while the sheet is held between the pair of registration rollers on the re-conveying path, its lateral position is corrected by the movement of the pair of rollers, and the sheet is conveyed again to the image forming section by a signal from the copying machine main body, and the back side of the sheet is is copied and double-sided copying is completed.

Also, if the copier's multiple copy mode is selected,
The flapper is switched and the sheet copied on the front side in the image forming unit is conveyed to the rate re-conveying path without passing through the ejection roller pair, and the lateral position of the sheet is corrected by the registration roller pair, similar to the double-sided copy mode. The sheet is then conveyed again to the image forming section by a signal from the copying machine main body, and the front surface of the sheet is copied, completing multiple copying.

←→ Problems to be Solved by the Invention By the way, the Sea 1 re-conveyance path is formed below the image forming section due to the arrangement of each device inside the copying machine main body, and furthermore, the small size of the copying machine Due to the need to reduce the height of the copying machine body due to the increase in the number of copying machines, the distance between the image forming section and the sheet re-conveying path is configured to be as small as possible, and the space becomes extremely narrow.

Therefore, the pair of registration rollers in the sea) and re-sakaki feeding path are as follows:
Since the sheet is moved in a direction perpendicular to the sheet conveyance direction in order to correct the lateral position of the sheet, troubles such as paper jams often occur, and it becomes very difficult to clear the jams.

(b) Means for Solving the Problems The present invention aims to solve the above-mentioned problems, and as shown in FIG.
A guide plate 2 that guides the sheet to a four-roller pair (registration roller pair) 1 which is biased and n-contacted with the other four-roller 1b against a.
are disposed in connection with the other roller 1b, and fulcrum portions 1c, 5 are formed at positions close to the roller pair 1 of the guide plate 2, the fulcrum axes of which are perpendicular to the sheet conveyance direction. , based on the rotation of the guide plate 2 about the fulcrum parts 1c and 5, +? ? J. This is characterized in that the other roller 1b is separated from the one roller 1a.

(E) Operation Based on the above-mentioned configuration, the roller pair (registration roller pair)
11 If a problem such as a paper jam occurs, rotating the guide plate 2 around the fulcrum 5 or 6 will cause the roller pair 1 to
The other roller 1b is separated from the one roller 1a, the pressure between the rollers of the roller pair 1 is released, and the jam can be easily cleared.

(F) Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Copying machine U (as shown in Figure 4, document table 7, light R9
, lens system 10.2 cassettes 11 and 12? A cylindrical photoreceptor 13 is arranged in the main body of the copying machine. Further, near the periphery of the photoreceptor 13, there are two developing units 15 and 16 each containing toner of a different color.
Cleaner 17, primary charger 19, and conveyance device 20
A transfer charger 21 and a separation charger 22 are provided at the tip of the transfer charger 21 . In addition, paper feed rollers 23 and 25 are provided in the cassette 1-11.12 portion, and paths 26.2 and 25 are respectively provided.
7 to a pair of registration rollers 29. Further, a fixing device @30 is provided at the rear end portion of the conveyance device 20, and the fixing device ? ! There is a first flapper 3 on the downstream side of I30.
1 and 27 lappers 32 and a pair of rollers 3 on the downstream side thereof.
3 is arranged near the discharge roller pair 33.
A sheet trailing edge detection sensor 35 is installed to detect the trailing edge of the sheet discharged from the sheet. Also, the first flapper 3
1 is branched and selected to form a sheet re-conveyance path 36, and this re-conveyance path 36 includes a pair of conveyance rollers 37,
39 and a pair of lateral registration rollers 1 to be described later are arranged,
Furthermore, it is communicated with the registration roller 29.

As shown in FIG. 2, the lateral registration roller pair 1 is configured such that an upper roller 1b is biased and elastically contacted by a spring mechanism (not shown) to a lower roller 1a rotatably supported by a fixed member. A moving guide plate 2 having an upwardly inclined surface at its tip is rotatably connected and supported by the roller shaft IC of the upper roller 1b. Further, the movable guide plate 2 has protrusions 5, 5 arranged at both lower ends near the upstream side of the upper roller 1b, and the protrusions 5, 5 abut against the fixed guide plate 4, so that the movable guide plate 2 is positioned and supported. Further, by the rotation of the movement guide plate 2 in the direction of arrow A, the upper roller 1b is rotated in the direction of arrow B using the projections 5, 5 as fulcrums against a spring mechanism (not shown), and the upper roller 1b is moved downward. It is separated from the roller 1a. Further, cam portions 6, 6 are arranged at both front ends of the moving guide plate 2, facing the roller shaft 1d of the lower roller 1a, and when the moving guide plate 2 rotates in the direction of arrow C (Fig. 3), The cam portion 6°6 contacts the lower roller shaft 1d, the upper roller 1b is rotated in the direction of arrow B using the cam portions 6, 6 as fulcrums, and the upper roller 1b is separated from the lower roller 1a.

Further, as shown in FIG. 1, the conveying device 20 having a large number of rollers is configured to be rotatable around a downstream roller shaft 20a, and the lower roller 29a of the L-distroller 29 and its vicinity are rotated. The lower guide plate 40 is configured to be rotatable around a rotation center 41 on the upstream side, and furthermore, the upstream end of the lower guide plate 40 is placed on and connected to the upstream end of the conveyance device 20. Therefore, when the conveyance device 20 is rotated in the direction indicated by the arrow, the registration lower roller 29a and the lower guide plate 40 are rotated in conjunction with the rotation, and the conveyance device 20 is further brought into contact with the upper end of the moving guide plate 2 and moved. A rotation force is applied to the guide plate 2 in the direction of arrow A.

Since this embodiment has the above-described configuration, when the light source 9 moves, the document M placed on the original stacking table 7 is irradiated by the light source 9, and the reflected light passes through the lens system 10 and is
An electrostatic latent image is formed by forming an image on the uniformly charged surface of the photoreceptor 13 by the I-electrode 19, and then, as the photoreceptor 3 rotates in the direction of the arrow, the electrostatic latent image is developed! A toner image is formed at the 16th position. On the other hand, the sheet S loaded in the cassette 11 or 12 is sent to the paper feed roller 23 or 25, aligned with the toner image on the surface of the photoreceptor by the registration roller 29, and further transferred to the transfer charger 21. The toner image is transferred to the sheet surface. Further, the sheet S carrying the toner image is separated from the photoreceptor 13 by a separation charger 22, sent to a fixing device 30 by a conveyance device 20, and fixed there.

Then, if double-sided copy mode is selected, the fixing M
The sheet S fixed at 30 is guided by the first flapper 31, and is conveyed toward the outside of the main body of the copying machine U by the forward rotation of the discharge roller pair 33.

At this time, the second flapper 321 blocks the sheet transport path, but since the flapper 32 is made of a light member and is supported rotatably in the direction of arrow F, the sheet S can pass through. As a result, the tip of the sheet is pushed up and retracted from the sheet S, and the sheet 1-S
It will not be a hindrance to the passage of. Furthermore, the sheet I-5 is conveyed by the forward rotation of the discharge roller pair 33, and the sheet I-S
The rear end of is sea! - When detected by the trailing edge detection sensor 35, the pair of ejecting rollers 33 is rotated in the opposite direction, and the sheet S is guided by the second flapper 35 and the first flapper 31, and guided to the sheet re-transport path R136. It will be destroyed. Furthermore, the note S is conveyed forward by the stopped horizontal registration roller pair 1 by the rotation of the vagina feed roller pair 37 and 39, and after the tip of S abuts against the registration roller pair 1, the notebook S is transferred to the front of the stopped horizontal registration roller pair 1. 37 and 39 are stopped, and the sheet S is stopped in a state forming a loop in front of the pair of lateral registration rollers 1.

Then, when a copy signal for the other side is sent from the copying machine main body, the lateral registration roller pair 1 is rotated, and further, with the lateral registration roller pair 1 biting and rounding the sheet S, the rate is The sheets 1-IJ7 are moved in a direction perpendicular to the feeding direction until the side edges are detected by an optical sensor (not shown), and the lateral position of the sheet S with respect to the feeding direction is adjusted. Further, the sheet S is conveyed by a pair of registration rollers 29, and a toner image is transferred to the back side of the sheet (the side on which vK is not copied) by the photoconductor 13 and the transfer charge N21, etc., and then fixed. After being fixed in the device 30, the sheets copied on both sides are discharged by a pair of discharge rollers 33 to the outside of the copying machine main body.

Further, when the multiple copying mode is selected, the first flapper 31 is switched to the sheet re-conveying path 36 side, and the copied sheet S fixed by the fixing device 30 is guided to the first flapper 31. The sheet is then guided to the sheet re-conveying path 36. And that sea! -S, as in the case of double-sided copying described above, the lateral position is adjusted by the pair of lateral registration rollers 1, and the sheet S is further conveyed by the pair of registration rollers 29, and the side of the sheet S that has been copied once is The second image is duplicated. Furthermore, after the multiple copied sheet is fixed by the fixing device 30, it is guided by the first flapper 31 which has been switched to the ejection roller pair 33 side, and is ejected to the outside of the copying machine main body by the ejection roller pair 33. .

Next, jam handling when a trouble such as a paper jam occurs in the pair of lateral registration rollers 1 of the copying machine U will be described.

First, let's discuss how to clear a jam in a state where the lateral registration roller pair 1 is holding the leading edge of the sheet.

If a trouble such as a paper jam occurs in this state, the trouble is detected by a signal transmitted from a paper jam detection device or safety device (not shown), and the copying machine U is stopped.

Then, when the operator opens the front cover of the copying machine U and rotates the moving guide plate 2 in the direction of the arrow C about the axis IC as shown in FIG. The upper roller 1b is brought into contact with the shaft 1d, and as the guide plate 2 rotates, the upper roller 1b is raised in the direction of arrow B against a spring mechanism (not shown) using the contact portion of the cam portion 6.6 as a fulcrum. The sheet is separated from the lower roller 1a, and a gap h (h is larger than the thickness of the sheet) is generated between the upper roller 1b and the lower roller 1a. Due to the gap h, the leading edge of the sheet is easily removed from the pair of tank registration rollers 1, and jam processing is performed.

Next, jam processing will be described in a state where the front end of the sheet is held between the pair of registration rollers 29 and the rear end of the sheet is held between the pair of tank registration rollers 1.

If a trouble such as a paper jam occurs in this state, the trouble is detected and the copying machine U is stopped, as described above. Then, by rotating a lever (not shown) by the operator, the transport device 1120 is moved as shown in FIG.
When rotated in the direction indicated by the arrow, the lower registration roller 29a and the lower guide plate 40 are rotated with the rotation ξ, the upper registration roller 29b and the lower roller 29a are separated, and the leading edge of the sheet is easily removed from the pair of registration rollers 29. It will be removed. at the same time,
By rotating the conveying device 20 in the direction of the arrow, the conveying device 20 comes into contact with the upper end of the moving guide plate 2, and the moving guide plate 2 rotates in the direction of the arrow A using the protrusions 5, 5 as fulcrums. This rotation causes the upper roller 1 of the lateral registration roller pair 1 to
b is separated from the lower roller 1a, and a gap h is generated between the upper roller 1b and the lower roller 1a. And the corresponding gap h
As a result, the trailing edge of the sheet is easily removed from the pair of tank registration rollers 1, and the jam is cleared.

Although this embodiment has described the release of the pressure between the rollers in the pair of lateral registration rollers 1 in the sheet re-conveying path 36, the same effect can be obtained if the pair of rollers has pressure between the rollers that clamp the sheet. Of course.

(1.) As described in detail, according to the present invention, in a pair of rollers in which one roller is opposed to the other roller, a guide plate for guiding the rate is connected to the other roller 1b. and arranged,
Further, a fulcrum part having a fulcrum axis in a direction perpendicular to the sheet meat feeding direction is formed on the guide plate, and the other roller and one roller are separated from each other based on rotation of the guide plate about the fulcrum part. As a result, the pressure between the roller pairs can be easily released by simply rotating the guide plate, and troubles such as paper jams caused by the roller pairs can be easily cleared.

Furthermore, since the guide plate can be rotated in the opposite direction in conjunction with the rotation of the other guide means to release the pressure between the rollers, jams can be easily handled over a wide range. In other words, since the roller pair is configured to move around the fulcrum when the guide plate rotates in one direction, and also around the fulcrum when the guide plate rotates in the other direction, paper jams can be avoided. The method of releasing the pressure between the four roller pairs can be selected depending on the position, and efficient jam handling can be performed in response to many cases of paper jams.

[Brief explanation of drawings]

FIG. 1 is a side view showing a sheet conveying device according to the present invention, FIG. 2 is a side view showing its roller pair and guide plate portion, and FIG. 3 is a side view showing the state in which the guide plate is rotated in FIG. 4 are side views of a copying machine to which the present invention is applied. 5.6...Fully point (5U...copier protrusion,...cam part)

Claims (1)

[Claims] (1) A sheet conveying device that conveys the sheet based on the rotation of the roller pair by holding the sheet between a pair of rollers with one roller facing the other roller, and a guide that guides the rate to the roller pair. A plate is disposed in connection with the other roller, and a fulcrum portion having a fulcrum axis in a direction perpendicular to the sheet conveyance direction is formed on the guide plate, and the guide plate is disposed in a direction in which the guide plate is released and in the opposite direction. The other roller and the one roller can be rotated based on the rotation of the guide plate in the opening direction about the fulcrum part or the rotation in the opposite direction in conjunction with the opening movement of the other guide means. A sheet conveying device comprising a separating means for separating the sheets.