JPH07125882A - Paper carrying device - Google Patents

Abstract

PURPOSE:To eliminate the installation of a pair of auxiliary carrying rollers between a resist stopper and a photoreceptor by enlarging an oscillation stroke of a resist stopper with a moving member to. make the resist stopper go ahead and back into/from the paper carrying passage. CONSTITUTION:When a lower roller 51b of a pair of carrying rollers 51 is separated from an upper roller 51a, a moving member 56 makes a resist stopper 51 go ahead into the paper carrying passage A, and when the lower roller 51b pressure-contacts with the upper roller 51b, the moving member 56 makes the resist stopper 56 go back from the paper carrying passage A. Since the lower roller 51b of the pair of carrying rollers 51 can be therefor separated from the upper roller 51a under the condition that the resist stopper 52 goes ahead into the paper carrying direction A, a danger that a paper is curved large is eliminated. Furthermore, papers can be pinched by the lower roller 51b and the upper roller 51a and securely carried under the condition that the resist stopper 52 goes back from the paper carrying passage A. Consequently, installation of a pair of auxiliary carrying rollers in the downstream of the pair of carrying rollers 51 is eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet conveying device installed in an electrophotographic copying machine, a printer or the like.

[0002]

2. Description of the Related Art Conventionally, as an image forming apparatus such as an electrophotographic copying machine or a printer for transferring an electrostatic latent image formed on a photosensitive drum to a sheet after developing it into a toner image, it is extremely small in size. A so-called portable type is provided (see, for example, Japanese Patent Publication No. 2-17453).

In this type of image forming apparatus, an electrostatic latent image corresponding to an original image formed on a photosensitive member is visualized as a toner image and then transferred to a sheet, and an image forming apparatus and a sheet are formed inside the apparatus body. In addition to being introduced into the image forming apparatus, it is equipped with a sheet conveying device that discharges the image forming apparatus body from the image forming apparatus main body, a drive system that drives these, and a control circuit and other functional parts such as electrical components. The transport device is a pair of transport rollers that sandwich and transport the paper, and advances into the paper transport path to temporarily hold the paper introduced into the main body of the device before the photoconductor and transport the paper at a predetermined timing. Evacuate from the road,
It is provided with a resist stopper for supplying the paper to the photoconductor and a fixing unit for fixing the toner image transferred on the paper.

[0004]

In order to popularize the image forming apparatus having the above structure for home use and personal use,
It is desirable to reduce the size and weight as much as possible and to reduce the manufacturing cost and the selling price. However, since the sheet conveying device configured in the image forming apparatus needs to slip the sheet and the conveying roller pair to stop the sheet conveyance when the sheet hits the resist stopper, the conveying roller is The pressure contact force between the pair of rollers cannot be kept strong. For this reason, the grip of the sheet by the pair of conveying rollers becomes unstable, and the sheet may be fed obliquely with respect to the photoconductor, so that defective conveyance is likely to occur.
Therefore, it is necessary to further provide a pair of auxiliary conveying rollers having a stronger pressure contact force between the rollers between the resist stopper and the photoconductor, which causes a problem that the manufacturing cost becomes high and the apparatus becomes large. It was

The present invention has been made in view of the above problems, and does not require a pair of auxiliary conveying rollers between the resist stopper and the photosensitive member, so that the manufacturing cost can be reduced and the size can be reduced. An object is to provide a paper transport device.

[0006]

A sheet conveying device according to a first aspect of the present invention for achieving the above object is a pair of conveying rollers for sandwiching a sheet to convey it to a predetermined portion, and a retractable pair of sheets for a sheet conveying path. In the state where it is provided and has advanced to the paper transport path, the front end of the paper transported by the transport roller pair is abutted to temporarily stop the paper, and the paper is retreated from the paper transport path at a predetermined timing to And a registration stopper for canceling the temporary stop of the conveyance roller, which is provided so as to be swingable around the first support shaft, so that one roller of the pair of conveyance rollers can be brought into contact with and separated from the other roller. A first swinging member that supports and a second swinging member that is swingably provided around a second support shaft that is parallel to the first support shaft and that supports the resist stopper so that the resist stopper can advance and retreat with respect to the sheet conveyance path. Rocking member of With the drive means for swinging the first swinging member and one roller of the transport roller pair separated from the other roller, the resist stopper is advanced to the sheet transport path, and the one roller is moved to the other. With the roller pressed, the resist stopper is retracted from the paper conveyance path, and the swinging stroke of the resist stopper is
It is characterized by comprising an interlocking member for interlocking the second oscillating member with the first oscillating member so as to be larger than the oscillating stroke of the one roller.

Further, in the sheet conveying apparatus according to the second aspect of the invention, the advance stroke of the resist stopper to the sheet conveying path is restricted by the first support shaft.

[0008]

According to the sheet conveying apparatus of the first aspect, when the first rocking member is rocked by the drive means, the second rocking member is moved through the interlocking member. It is possible to move the resist stopper forward and backward with respect to the paper transport path, and to move one roller of the transport roller pair to and from the other roller. Moreover, the interlocking member allows one roller of the pair of transport rollers to be separated from the other roller when the resist stopper advances into the paper transport path, and when the resist stopper retracts from the paper transport path,
The sheet can be sandwiched between the one roller and the other roller and conveyed to a predetermined portion.

Further, the interlocking member allows the second swinging member to swing so that the swinging stroke of the resist stopper is larger than the swinging stroke of the one roller, so that the space is limited. Even when the swing stroke of the one roller cannot be secured, the swing stroke of the resist stopper can be secured sufficiently. Therefore, the resist stopper can be sufficiently advanced to the paper conveyance path to reliably stop the paper.

Further, according to the sheet conveying apparatus of the second aspect, since the advance stroke of the resist stopper to the sheet conveying path is regulated by the first support shaft, a member for regulating the stroke. Need not be provided separately.

[0011]

Embodiments will be described in detail below with reference to the accompanying drawings showing embodiments. FIG. 2 is a schematic diagram showing the internal structure of a copying machine as an image forming apparatus equipped with the sheet conveying device of the present invention. The copying machine is a document table 1 made of a transparent glass plate.
2 is a so-called table moving type in which a document placed on the document table 1 is illuminated and scanned by moving the document in the left-right direction in FIG. After visualizing the electrostatic latent image formed on the optical system 3 for scanning and the photoconductor drum 41,
The image forming apparatus 4 for transferring the sheet, the sheet conveying apparatus 5 for conveying the sheet along the sheet conveying path A of the copying machine, and the like are provided.

As the image forming device 4, the photosensitive drum 4 is used.
1, a charging charger 42, a developing device 43, a transfer charger 44, and a cleaner 45 are arranged in this order, and an original image is formed on the outer peripheral surface of the photosensitive drum 41 uniformly charged by the charging charger 42. After forming the image to form the electrostatic latent image, the electrostatic latent image is developed.
The toner image is visualized by the transfer charger 44, the toner image is transferred to the sheet by the transfer charger 44, and the residual toner is removed by the cleaner 4.
This is a conventionally known configuration in which it is collected by means of 5.

Referring also to FIG. 1, the paper transport device 5 is
A pair of conveying rollers 51 that sandwiches the sheet and introduces the sheet into the copying machine, a pair of resist stoppers 52 that abut the leading edge of the sheet conveyed by the pair of conveying rollers 51 to temporarily stop the sheet, and the pair of conveying rollers 51. Lower roller 51
drive means 53 for bringing b into contact with and separating from the upper roller 51a
An interlocking member 56 for advancing / retreating the resist stopper 52 with respect to the sheet conveying path A in association with the contact / separation operation of the lower roller 51b, a fixing unit 57 for fixing the toner image transferred onto the sheet, and the like. There is.

The upper roller 51a of the conveying roller pair 51 is supported by a drive shaft 51c which is rotationally driven by the drive system of the copying machine. The drive shaft 51c is rotatably supported by an upper guide 43b projecting from the developing housing 43a to guide the upper conveyance of the paper.
The lower roller 51b of the conveying roller pair 51 is the first support shaft S1.
It is rotatably supported by the tip end portion of a first swinging member 54 that can swing around, and by the swinging operation of the first swinging member 54, it is pressed against the upper roller 51a or the upper roller 51a. Can be separated from. The first support shaft S1 and the first swinging member 54 are provided in a recess 71 formed in the lower casing 7 of the copying machine, and the lower roller 51b is separated from the upper roller 51a.
It is designed to sink into the recess 71. The recess 71 is covered with a cover 72 that also serves as a lower conveyance guide for the sheet (see FIG. 3), and the lower roller 51b contacts the upper roller 51a through a window 72a formed in the cover 72. It can be separated. Further, the resist stopper 52 is provided with a notch 72 formed in the cover 72.
It is possible to move back and forth to the paper transport path A through b. The first support shaft S1 is used for the lower casing 7 of the copying machine.
It is rotatably supported by.

The resist stoppers 52 are arranged on both sides of the first swinging member 54, and are provided at the tip of a second swinging member 55 which is swingable around the second support shaft S2. ing. The resist stopper 52 is provided so as to project upward from the tip of the second swing member 55.
By the swing operation of the second swing member 55, the paper transport path A
It is possible to move the sheet to the sheet feeding path or to withdraw from the sheet transport path A. Paper transport path A of the resist stopper 52
With the advance of the sheet, the leading end of the sheet conveyed by the pair of conveying rollers 51 can be brought into contact with the registration stopper 52 to temporarily stop the sheet. Further, the temporary stop can be released as the resist stopper 52 is retracted from the sheet conveyance path A.

The first support shaft S1 supporting the first swinging member 54 extends above one of the second swinging members 55 and extends to near the side end of the recess 71 of the lower casing 7. The driving means 53 provided in the vicinity of the side end is capable of rotating by a predetermined angle. As shown in FIG. 4, the drive means 53 includes a rotating lever 53a fitted to one end of the first support shaft S1 so as to be integrally rotatable, and the rotating lever 53a to pull the first supporting shaft 53a. A coil spring 53b that urges the shaft S1 to rotate clockwise in the figure, and the first support shaft S1 against the tensile force of the coil spring 53b.
And a solenoid 53c that rotates the counterclockwise. According to the driving means 53, the first support shaft S1 is excited by exciting the solenoid 53c.
Can be rotated counterclockwise to bring the lower roller 51b into pressure contact with the upper roller 51a. In addition, by releasing the above-mentioned excitation, the tensile force of the coil spring 53b
The lower roller 51b can be separated from the upper roller 51a by rotating and returning the first support shaft S1 clockwise.

The interlocking member 56, as shown in FIG.
A hook type one end of which is rotatably fitted into the swing tip 54a of the first swing member 54 and the other end of which is integrally rotatably fixed to the second support shaft S2. When the first rocking member 54 rocks clockwise in FIG. 2, the second rocking member 55 rocks clockwise, and the first rocking member 54 moves.
When it is swung counterclockwise in the figure, the second swing member 55 is swung counterclockwise. That is, when the lower roller 51b of the conveying roller pair 51 is separated from the upper roller 51a, the interlocking member 56 causes the resist stopper 52 to advance to the sheet conveying path A, and causes the lower roller 5 to move.
When the 1b is brought into pressure contact with the upper roller 51a, the second swing member 55 is interlocked with the first swing member 54 so that the resist stopper is retracted from the sheet conveyance path A.

The second support shaft S2, the second swing member 55, and the interlocking member 56 are integrally formed of synthetic resin. FIG. 5 shows the pair of transport rollers 51,
FIG. 7 is a schematic side view showing an arrangement state of a resist stopper 52, a first swing member 54, a second swing member 55, and an interlocking member 56. As shown in the figure, the first support shaft S1 is arranged above the second swinging member 55 on one side. Further, the distance L between the resist stopper 52 and the second support shaft S2
1 is longer than the distance L2 between the second support shaft S2 and the swing tip 54a of the first swing member 54 to which the interlocking member 56 is connected, that is, the swing of the lower roller 51b. The swing stroke Δt of the registration stopper 52 is set to be larger than the dynamic stroke ΔT. Further, when one of the resist stoppers 52 advances to the paper transport path A, it comes into contact with the first support shaft S1 to restrict the advance stroke thereof. Therefore, it is not necessary to separately configure a member for restricting the stroke, and the cost can be reduced accordingly.

In the case of the sheet conveying device 5 having the above-mentioned structure, the resist stopper 52 is advanced to the sheet conveying path A,
Since the lower roller 51b of the conveying roller pair 51 can be separated from the upper roller 51a, the registration stopper 52
There is no fear that the sheet that hits against will be greatly curved or will be separated from the resist stopper 52. Further, with the resist stopper 52 retracted from the sheet conveying path A, the sheet can be sandwiched by the lower roller 51b and the upper roller 51a and reliably conveyed to the photosensitive drum 42.
For this reason, it is not necessary to provide the auxiliary transport roller pair on the downstream side of the transport roller pair 51, and the structure of the device can be simplified and the device can be downsized accordingly.

Moreover, since the swing stroke Δt of the resist stopper 52 is set to be larger than the swing stroke ΔT of the lower roller 51b, the swing stroke of the lower roller 51b should be secured in terms of space. Even if it is not possible, the swing stroke of the resist stopper 52 can be sufficiently secured. Therefore, the resist stopper 52 is sufficiently advanced to the sheet conveyance path A,
It is possible to prevent the sheet from passing over the resist stopper 52.

The drive means 53 may be constituted by a link mechanism that rotates the first support shaft S1 in association with the movement of the document table 1, instead of the solenoid 53c. In addition to the above copying machine, the present invention can be implemented by being applied to various kinds of devices that need to be temporarily stopped during conveyance of paper.

[0022]

As described above, according to the sheet conveying apparatus of the present invention, when the sheet is temporarily stopped by the resist stopper, one roller of the pair of conveying rollers is separated from the other roller and the temporary stop is performed. At the time of releasing, the sheet can be sandwiched between the one roller and the other roller and reliably transported to the predetermined portion, so that the conventional auxiliary transport roller pair becomes unnecessary, and the manufacturing cost of the apparatus is reduced accordingly. The cost can be reduced and the device can be downsized.

Moreover, since the swing stroke of the resist stopper is set to be larger than the swing stroke of the one roller, the swing stroke of the one roller cannot be secured in terms of space. Even in such a case, the swing stroke of the resist stopper can be ensured, and as a result, the resist stopper can be sufficiently advanced into the paper conveyance path to reliably stop the paper.

Further, according to the sheet conveying apparatus of the second aspect, since the advance stroke of the resist stopper to the sheet conveying path is regulated by the first support shaft, a member for regulating the stroke. It is not necessary to separately provide the device, and a unique effect that the manufacturing cost can be further reduced is achieved.

[Brief description of drawings]

FIG. 1 is a perspective view of an essential part showing an embodiment of a sheet conveying device of the present invention.

FIG. 2 is a schematic view showing the internal structure of a copying machine equipped with the sheet conveying device of the present invention.

FIG. 3 is a perspective view of a main part of a paper transport path.

FIG. 4 is a side view of a main part of a driving unit.

FIG. 5 is a schematic side view of a sheet conveying device.

[Explanation of symbols]

 5 Paper Conveying Device 51 Conveying Roller Pair 52 Registration Stopper 53 Driving Means 54 First Oscillating Member 55 Second Oscillating Member 56 Interlocking Member S1 First Spindle S2 Second Spindle A Paper Transport Path

Claims (2)

[Claims] 1. A pair of conveying rollers for sandwiching a sheet and conveying the sheet to a predetermined portion, and a pair of conveying rollers provided so as to be able to move forward and backward with respect to the sheet conveying path and being advanced to the sheet conveying path. Abut the tip to temporarily stop the paper, and withdraw from the paper transport path at a predetermined timing,
In a sheet conveying device including a registration stopper that releases a temporary stop of a sheet, it is swingably provided around a first support shaft, and one roller of the pair of conveying rollers can be brought into contact with and separated from the other roller. A first swinging member that supports the first stopper and a second swinging member that swings around a second spindle that is parallel to the first spindle, and that supports the resist stopper so that the resist stopper can advance and retreat with respect to the sheet conveyance path. No. 2 swing member, drive means for swinging the first swing member, and one of the pair of transport rollers separated from the other roller, the resist stopper is advanced to the sheet transport path. , With the one roller in pressure contact with the other roller, the resist stopper is retracted from the sheet conveying path, and the swing stroke of the resist stopper is larger than the swing stroke of the one roller. And a link member that links the second swing member to the first swing member. 2. The sheet conveying apparatus according to claim 1, wherein the resist stopper is restricted in its stroke of advance into the sheet conveying path by the first support shaft.