JP3261224B2 - Paper transport device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper transport device provided in an electrophotographic copying machine or printer.

[0002]

2. Description of the Related Art Conventionally, an electrostatic latent image formed on a photosensitive drum is visualized into a toner image and then transferred to paper. A so-called portable type is provided (for example, see Japanese Patent Publication No. 2-17453).

An image forming apparatus of this type is an image forming apparatus for developing an electrostatic latent image corresponding to an original image formed on a photoreceptor into a toner image, and then transferring the image onto a sheet, and a sheet inside the apparatus main body. And a functional part such as a paper transport device for driving the components, a driving system, and a control circuit and other electrical components, which are supplied to the image forming apparatus and then discharged from the image forming apparatus main body. The transport device includes a pair of transport rollers for nipping and transporting the paper, advancing to a paper transport path, and temporarily suspending the paper introduced into the apparatus main body in front of the photoconductor, and transporting the paper at a predetermined timing. Evacuate from the road,
The image forming apparatus includes a resist stopper that supplies the sheet to the photoconductor, a fixing unit that fixes the toner image transferred to the sheet, and the like.

[0004]

In order to spread 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 selling price. However, the paper transport device provided in the image forming apparatus needs to slip the paper and the transport roller pair to stop the transport of the paper when the paper hits the registration stopper. The pressing force between the pair of rollers cannot be increased. For this reason, the grip of the sheet by the pair of conveying rollers becomes unstable, and the sheet is easily supplied to the photoconductor obliquely.
Therefore, it is necessary to further provide a pair of auxiliary transport rollers between the resist stopper and the photoreceptor in which the pressing force between the rollers is increased, which increases the manufacturing cost and increases the size of the apparatus. Was.

The present invention has been made in view of the above problems, and does not require an auxiliary transport roller pair between a registration stopper and a photoreceptor, so that the manufacturing cost can be reduced and the size can be reduced. It is an object to provide a paper transport device.

[0006]

According to a first aspect of the present invention, there is provided a sheet transporting apparatus which includes a pair of transporting rollers for sandwiching a sheet and transporting the sheet to a predetermined portion, and a retractable and retractable sheet with respect to a sheet transporting path. In the state in which the sheet is advanced to the sheet conveyance path, the front end of the sheet conveyed by the conveyance roller pair is abutted to temporarily stop the sheet, and is retracted from the sheet conveyance path at a predetermined timing. And a registration stopper for releasing the temporary stop of the pair of transport rollers, wherein one of the pair of transport rollers can be moved toward and away from the other roller. A first swinging member to be supported, and a second swinging member which is swingably provided around a second support shaft parallel to the first support shaft, and supports the registration stopper so as to be able to advance and retreat with respect to the sheet transport path. Swinging member and A drive unit for swinging the first swing member, and a registration stopper is advanced to a sheet conveyance path in a state where one roller of the conveyance roller pair is separated from the other roller, and the one roller is moved to the other side. With the roller pressed against the roller, the resist stopper is retracted from the paper transport path, and the swing stroke of the resist stopper is
An interlocking member for interlocking the second rocking member with the first rocking member so as to be longer than the rocking stroke of the one roller ;
The advance stroke to the paper transport path is regulated by the support shaft.
Tei is Rukoto characterized in.

[0007]

[0008]

SUMMARY OF] According to the above SL for paper transportation device and swings the first swinging member by the drive means, first through the interlocking member 2
Can be linked with the swing of the first swing member, whereby the registration stopper can be moved forward and backward with respect to the paper transport path, or one roller of the transport roller pair can be moved to the other roller. And can be separated from each other. In addition, the interlocking member allows one of the pair of conveyance rollers to be separated from the other roller when the registration stopper advances to the paper conveyance path, and the one roller when the registration stopper retreats from the paper conveyance path. The sheet can be conveyed to a predetermined portion by sandwiching the sheet between the roller and the other roller.

Further, the second swinging member can be swung by the interlocking member such that the swinging stroke of the registration stopper is larger than the swinging stroke of the one roller, so that space is reduced. Even when the swing stroke of the one roller cannot be secured, the swing stroke of the registration stopper can be sufficiently secured. For this reason, the registration stopper can be sufficiently advanced into the paper transport path, and the paper can be stopped temporarily.

[0010] les resist stopper, since the first support shaft is advancing stroke of the sheet conveying path is regulated, there is no need to separately provide a member for regulating the stroke.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 2 is a schematic diagram showing the internal configuration of a copying machine as an image forming apparatus equipped with the paper transport device of the present invention. The copying machine includes a platen 1 made of a transparent glass plate.
2 is moved in the left-right direction in FIG. 2 to illuminate and scan the original placed on the original platen 1. In this case, the original moved by the original plate 1 is illuminated. After visualizing the electrostatic latent image formed on the optical system 3 and the photosensitive drum 41 for scanning,
The image forming apparatus includes an image forming device 4 for transferring the image on a sheet, a sheet conveying device 5 for conveying the sheet along a sheet conveying path A of the copying machine, and the like.

The image forming apparatus 4 includes a photosensitive drum 4
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 an electrostatic latent image by forming an image, the electrostatic latent image is
The transfer charger 44 transfers the toner image to paper, and the residual toner is
5 is a conventionally known configuration in which collection is performed by using a conventional method.

Referring also to FIG. 1, the paper transport device 5 includes:
A pair of transport rollers 51 for sandwiching the paper and introducing it into the copying machine, a pair of resist stoppers 52 for abutting the leading end of the paper transported by the pair of transport rollers 51 to temporarily stop the paper, and a pair of transport rollers 51 Lower roller 51
drive means 53 for moving b toward and away from upper roller 51a
And an interlocking member 56 for moving the registration stopper 52 forward and backward with respect to the paper transport path A in conjunction with the contact and separation operation of the lower roller 51b, and a fixing unit 57 for fixing the toner image transferred to the paper. I have.

The upper roller 51a of the transport roller pair 51 is supported by a drive shaft 51c which is driven to rotate by a drive system of the copying machine. The drive shaft 51c is rotatably supported by an upper guide 43b protruding from the developing housing 43a to guide the upper transport of the sheet.
The lower roller 51b of the transport roller pair 51 is connected to the first support shaft S1.
The first swinging member 54 is rotatably supported by the tip of a first swinging member 54 that can swing around. The swinging operation of the first swinging member 54 allows the first swinging member 54 to come into pressure contact with the upper roller 51a, And can be separated from it. The first support shaft S1 and the first swing member 54 are provided in a concave portion 71 formed in the lower casing 7 of the copying machine, and the lower roller 51b is separated from the upper roller 51a.
It sinks into the concave portion 71. The concave portion 71 is covered by a cover 72 also serving as a transport guide on the lower side of 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 is detachable. The resist stopper 52 is provided with a notch 72 formed in the cover 72.
b can be advanced to and retracted from the paper transport path A. The first support shaft S1 is connected to 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 distal end of a second swinging member 55 which can swing around the second support shaft S2. ing. The resist stopper 52 is provided so as to protrude upward from the distal end of the second swinging member 55.
By the swing operation of the second swing member 55, the sheet transport path A
Or withdraw from the paper transport path A. The paper transport path A of the resist stopper 52
As the paper advances, the leading end of the paper conveyed by the conveyance roller pair 51 abuts against the resist stopper 52 to temporarily stop the paper. In addition, the temporary stop can be released with the retreat of the registration stopper 52 from the paper transport path A.

A first support shaft S1 for supporting the first swing member 54 extends above one of the second swing members 55 and extends to near the side end of the concave portion 71 of the lower casing 7. In addition, the drive means 53 provided near the side end portion can be turned by a predetermined angle. As shown in FIG. 4, the driving means 53 includes a rotating lever 53a fitted to one end of the first support shaft S1 so as to be integrally rotatable, and a first support by pulling the rotating lever 53a. A coil spring 53b for urging the shaft S1 to rotate clockwise in the figure, and a first support shaft S1 against the tensile force of the coil spring 53b.
And a solenoid 53c for rotating 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 press the lower roller 51b against the upper roller 51a. In addition, by canceling the excitation, the tensile force of the coil spring 53b causes
By rotating the first support shaft S1 clockwise and returning, the lower roller 51b can be separated from the upper roller 51a.

The interlocking member 56, as shown in FIG.
One end is rotatably fitted to the swinging end portion 54a of the first swinging member 54, and the other end portion is a hook type fixed to the second support shaft S2 so as to be integrally rotatable, When the first swinging member 54 swings clockwise in FIG. 2, the second swinging member 55 swings clockwise, and the first swinging member 54
Swings counterclockwise in the same figure, the second swinging member 55 swings counterclockwise. That is, when the lower roller 51b of the transport roller pair 51 is separated from the upper roller 51a, the interlocking member 56 causes the registration stopper 52 to advance into the paper transport path A, and
When the first roller 1b is pressed against the upper roller 51a, the second rocking member 55 is moved in conjunction with the first rocking member 54 so that the registration stopper is retracted from the sheet transport path A.

The second support shaft S2, the second swinging member 55, and the interlocking member 56 are integrally formed of synthetic resin. FIG. 5 shows the pair of transport rollers 51,
FIG. 9 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 disposed above the second swinging member 55 on one side. Further, the distance L between the resist stopper 52 and the second support shaft S2 is determined.
1 is longer than the distance L2 between the second support shaft S2 and the swinging tip 54a of the first swinging member 54 to which the interlocking member 56 is connected, that is, the swinging of the lower roller 51b. The swing stroke Δt of the resist stopper 52 is set to be larger than the dynamic stroke ΔT. Further, when the one resist stopper 52 advances into the paper transport path A, its advance stroke is regulated by abutting on the first support shaft S1. Therefore, there is no need to separately configure a member for regulating the stroke, and the cost can be reduced accordingly.

In the case of the paper transport device 5 having the above-described configuration, in a state where the registration stopper 52 has advanced to the paper transport path A,
Since the lower roller 51b of the transport roller pair 51 can be separated from the upper roller 51a, the registration stopper 52
There is no danger that the paper hitting the sheet will be greatly curved or separated from the registration stopper 52. Further, with the resist stopper 52 retracted from the sheet transport path A, the sheet can be sandwiched between the lower roller 51b and the upper roller 51a and transported to the photosensitive drum 42 reliably.
For this reason, there is no need to provide an auxiliary transport roller pair downstream of the transport roller pair 51, so that the structure of the apparatus can be simplified and the apparatus can be downsized.

In addition, since the swing stroke .DELTA.t of the registration stopper 52 is set to be larger than the swing stroke .DELTA.T of the lower roller 51b, the swing stroke of the lower roller 51b can be ensured in terms of space. However, the swing stroke of the resist stopper 52 can be sufficiently ensured even when the rotation cannot be performed. For this reason, the resist stopper 52 is made to sufficiently advance into the paper transport path A,
It is possible to prevent the paper from going over the resist stopper 52.

The driving means 53 may be constituted by a link mechanism for rotating the first support shaft S1 in conjunction with the movement of the document table 1, instead of the solenoid 53c. Further, the present invention can be applied to various apparatuses which need to temporarily stop a sheet during conveyance in addition to the above-mentioned copying machine.

[0022]

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

Further, since the swing stroke of the registration 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 space. Even in this case, the swing stroke of the registration stopper can be ensured, and as a result, the registration stopper can be sufficiently advanced into the sheet conveyance path, and the sheet can be stopped temporarily.

Further, Les resist stopper, since advancing stroke of the sheet conveying path by the first support shaft is restricted, there is no need to separately provide a member for regulating the stroke, further cheaper production costs It has a specific effect that it can be performed.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part showing an embodiment of a sheet conveying apparatus according to the present invention.

FIG. 2 is a schematic diagram showing an internal structure of a copier equipped with the paper transport 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 the driving means.

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

[Explanation of symbols]

 Reference Signs List 5 paper transport device 51 transport roller pair 52 registration stopper 53 drive means 54 first swing member 55 second swing member 56 interlocking member S1 first support shaft S2 second support shaft A paper transfer path

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B65H 9/06 G03G 15/00 518

Claims (1)

(57) [Claims] A pair of transport rollers for nipping and transporting a sheet to a predetermined portion; and a pair of transport rollers provided so as to be able to advance and retreat with respect to the sheet transport path. Abutting the leading end, the paper is temporarily stopped, and withdrawn at a predetermined timing from the paper transport path,
In a paper transport device having a registration stopper for releasing a temporary stop of a paper, the paper transport device is provided so as to be swingable around a first support shaft, and one of the transport roller pairs can be moved toward and away from the other roller. A first swing member that is supported on the first support shaft and a second support shaft that is swingable around a second support shaft that is parallel to the first support shaft, and that supports the registration stopper so as to be able to advance and retreat with respect to the sheet transport path. 2, a driving unit for oscillating the first oscillating member, and a resist stopper is advanced to the sheet conveying path in a state where one roller of the conveying roller pair is separated from the other roller. When the one roller is pressed against the other roller, the registration stopper is retracted from the sheet conveying path, and the swing stroke of the registration stopper is larger than the swing stroke of the one roller. In, and a coupling member for interlocking the second swing member to the first oscillating member, the resist stopper sheet conveyed by the first support shaft
Sheet conveying apparatus advancing stroke of the road is characterized that you have been restricted.