JP2000072276A - Sheet conveying device and sheet processing device - Google Patents

Abstract

(57) [Summary] [Problem] To prevent the balance of the contact pressure of both rollers from being affected by the gear in a pair of registration rollers transmitting the rotational force (drive) of the drive roller to a driven roller via a gear. To SOLUTION: A driving roller 112-1 has a side plate 114-.
1, 114-2 are rotatably supported via bearings 115. The driven roller 112-2 has side plates 114-1, 1
14-2 is rotatably supported via a bearing 117. The drive of the drive input gear 120 is transmitted to the drive roller 112-1 via the registration clutch 119. The drive roller 112-1 is driven by gears 121 and 122.
To the driven roller 112-2. Bearing 11
7 is slidably mounted on the slit 116.
The bias spring 11 for biasing the bearing 117 is provided in the slit 116.
8 is attached. The biasing spring 11 on the side plate 114-1 side
8 and the biasing spring 118 on the side plate 114-2 side are the same parts. The biasing spring 118 on the side plate 114-1 side is
It is set in the slit 116 in a state where the operation length is shorter than the urging spring 118 on the second side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet conveying apparatus provided in a sheet processing apparatus for performing a predetermined process on sheets fed one by one.

[0002] A typical example of the sheet processing apparatus referred to here is, for example, an image forming apparatus (printer,
(Copier, facsimile, etc.), and a document image reading device that reads an image of a document (sheet) fed one by one.

[0003]

2. Description of the Related Art In a sheet processing apparatus, a pair of registration rollers is used as one means for correcting a skew state of a moving sheet (during conveyance). In order to correct the skew state, the registration roller pair is kept in a rotation stop state, and the leading end of the moving sheet is abutted between the rollers (nip) to form a predetermined amount of loop. With this configuration, the entire leading end of the sheet abuts between the rollers, and the skew state of the sheet is corrected.

Each roller of the pair of registration rollers is rotatably supported near both ends by support. Drive from a drive source is transmitted to a drive roller (sheet conveyance drive roller) of the registration roller pair via a registration clutch. In addition, the driven roller (sheet conveyance driven roller) of the registration roller pair is brought into contact with the driving roller at a predetermined pressure.
It is urged by urging springs (pressure springs) installed near both ends. When the registration clutch is turned on, the drive roller rotates, and the driven roller is driven to rotate.

The pair of registration rollers includes one end of both rollers for the purpose of ensuring responsiveness when the registration clutch is turned on / off and preventing slippage of a driven roller during sheet conveyance. In some cases, a pair of gears meshing with each other is provided to transmit the rotational force of a driving roller to a driven roller.

[0006]

However, as described above,
In the case of a configuration in which the rotational force of the drive roller is transmitted to the driven roller via a gear, the reaction force due to the drive load of the gear acts against the spring pressure of the bias spring on the gear arrangement side. (I.e., the balance of the contact pressure between the driving roller and the driven roller) is disrupted, and the sheet after skew correction is skewed.

As a countermeasure for this, conventionally, the spring pressures of the two biasing springs are differentiated, and a biasing spring having a large spring pressure is used on the gear disposition side. It is necessary to manage two types of biasing springs having different pressures, and there is a risk of misuse.

Accordingly, the present invention has been made in view of the above-described circumstances. For example, even if the same component is used for two biasing springs, the balance of the contact pressure between the driving roller and the driven roller can be ensured. It is another object of the present invention to provide a sheet conveying apparatus that prevents skew of a sheet.

[0009]

Means for Solving the Problems (1) To achieve the above object, the present invention provides a sheet conveying drive roller rotatably supported near both ends by a first support and a second support, A sheet transport driven roller rotatably supported near both ends by the first support and the second support so as to form a pair with the sheet transport drive roller; First and second urging springs for urging the vicinity of both ends of the sheet conveying driven roller so as to abut against the driving roller at a predetermined pressure, and the rotational force of the sheet conveying driving roller to the sheet conveying driven roller. And a pair of gears meshing at one end of the sheet conveyance driving roller and the sheet conveyance driven roller, and use the same component for the first and second biasing springs. The present invention relates to a sheet conveying device.

(A) In order to achieve the above object, the present invention provides the first and second biasing springs so that a difference occurs in the spring force when setting the first and second biasing springs. Each set portion of the biasing spring is configured.

(B) In order to achieve the above object, the present invention provides at least a spring force changing means for changing a spring force when the biasing spring is set. It is characterized in that it is provided in one of them.

(2) The present invention for achieving the above object has the following features:
A sheet transport drive roller rotatably supported near both ends by a first support and a second support, and the first support and the second support so as to form a pair with the sheet transport drive roller. A sheet transport driven roller rotatably supported near both ends by a support, and urging portions near both ends of the sheet transport driven roller so that the sheet transport driven roller abuts the sheet transport driving roller at a predetermined pressure. The first and second urging means are engaged with one end of the sheet transport driving roller and one end of the sheet transport driven roller in order to transmit the rotational force of the sheet transport driving roller to the sheet transport driven roller. And a pair of gears, and uses the same component for the first and second urging means.

(A) In order to achieve the above object, the present invention is characterized in that an urging mechanism capable of adjusting an urging force is used as the first and second urging means.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

<First Embodiment> FIG. 1 shows the overall structure of a laser beam printer (sheet processing apparatus) to which the present invention is applied.

First, the overall configuration of the printer will be briefly described.

The printer comprises a separate upper body 200 and lower body 100.

This printer selectively feeds either sheets S stacked in a plurality of sheet cassettes 202 provided in the upper main body 200 or sheets S stacked in the lower main body 100. Can be sent. When a large number of sheets are used at one time, the sheet is fed from the lower body 100.

The sheets S stacked in the sheet feeding cassette 202 are fed by a sheet feeding roller 203 rotating counterclockwise.
Are fed out in order from the top sheet. The sheets S fed out from the sheet cassette 202 are separated one by one by a separation / feed roller pair 204 and sent to a registration roller pair 208 in a rotation stopped state.

The sheet S that has reached the registration roller pair 208 is transferred to a transfer portion between the photosensitive drum 209 rotating clockwise and the transfer roller 211 by the registration roller pair 208 which starts rotating at a predetermined timing. Is sent. The toner image on the photosensitive drum 209 is transferred to the sheet S passing through the transfer unit by the transfer roller 211.

A toner image is formed on the photosensitive drum 209 as follows. That is, the laser scanner 212 emits a laser beam L based on image information sent from a host computer (not shown) and irradiates the photosensitive drum 209 with the laser beam. Thereby, the photosensitive drum 20
An electrostatic latent image is formed on 9, and the electrostatic latent image is developed by a developing sleeve 210.

The sheet S to which the toner image has been transferred after passing through the transfer section is sent to the fixing device 213. Then, by heating and pressing while passing through the fixing nip of the identification attaching device 213, the toner image in the unfixed state is fixed on the sheet surface.

The sheet S, which has been subjected to the fixing process and has passed through the fixing device 213, passes through a discharge path 214,
Is discharged onto a paper discharge tray 216 outside the apparatus.

In the lower body 100, a sheet storage 10
2 are provided. The sheet storage 102 can be pulled out along the rail 103 toward the front of the drawing for replenishing the sheets S and the like.

In the sheet storage 102, there is provided a sheet stacking table 104 which can move up and down. The sheets S are stacked on the sheet stacking table 104.

The sheet loading table 104 is suspended horizontally by a plurality of wire ropes 105. Each wire rope 105 is wound around a pulley 106 and wound around a winding drum 107. When the winding drum 107 is rotated clockwise (in the direction of the arrow), the wire rope 1
05 is wound up, and the sheet stacking table 104 rises. The take-up drum 107 stops rotating when the sheet stacking table 104 is raised to a position where the uppermost surface of the stacked sheets S is detected by the sheet surface detection sensor 108 (a sheet-feedable position).

The sheet S stacked on the sheet stacking table 104 is fed by a sheet feeding roller 109 rotating counterclockwise.
Are fed out in order from the top sheet. The sheets fed from the sheet stacking table 104 are separated one by one by a separation / feed roller pair 110 and sent to a registration roller pair 112 in a rotation stopped state.

After a lapse of a predetermined time from the point when the registration sensor 111 detects the leading edge of the sheet, the registration roller pair 112 is turned on and a registration clutch 119 described later is turned on to start rotating. Within this predetermined time, a predetermined amount of loop is formed by the leading end of the sheet abutting the nip of the pair of registration rollers 112 in the rotation stopped state, and the formation of this loop causes the leading end of the sheet to abut the nip of the pair of registration rollers 112 The skew state of the sheet S is corrected.

The sheet S whose skew has been corrected is sent to a pair of conveying rollers 113 by a pair of registration rollers 112, and sent to a sheet feeding path 205 in the upper main body 200 via the entrance 206 by the pair of conveying rollers 113. Paper feed path 2
The sheet S sent to 05 is sent to the registration roller pair 208 in a rotation stopped state by the conveyance roller pair 207. After this, the flow of the sheet S is
Is the same as the sheet S fed from.

The registration sensor 111, the registration roller pair 112, and the conveyance roller pair 113 are connected to a relay conveyance unit 114.
It is installed in.

Next, the registration roller pair (sheet conveying device) 112 to which the present invention is applied will be described. FIG. 2 shows a detailed configuration of the registration roller pair 112.

The registration roller pair 112 includes the drive roller 11
2-1 and a driven roller 112-2. Near both ends of the drive roller 112-1 is a side plate (first and second support members).
Bearings 11 attached to 114-1 and 114-2
5 rotatably supported. The vicinity of both ends of the driven roller 112-2 is the side plates 114-1, 114-.
2 and is rotatably supported by a bearing 117 attached thereto.

Bearing 11 for supporting drive roller 112-1
5 is a hole 123 formed in the side plates 114-1 and 114-2.
(See FIG. 3). In addition, the driven roller 1
The bearing 117 for supporting 12-2 includes side plates 114-1, 11-1
It is slidably fitted in a slit 116 (see FIG. 3) formed in 4-2.

Bearing 1 fitted in slit 116
17 is urged in the direction of the bearing 115 by an urging spring (compression coil spring) 118 similarly mounted in the slit 116. The driven roller 112-2 is in contact with the drive roller 112-1 at a predetermined pressure by the urging force of the urging spring 118. The two urging springs 118 for urging the driven roller 112-2 are the same parts.

The drive of the drive input gear 120 is transmitted to the drive roller 112-1 via the registration clutch 119. The drive transmitted to the drive roller 112-1 is transmitted to the driven roller 112-2 via the idler gears 121 and 122.

In the configuration shown in FIG. 2, when the urging force of the urging spring 118 of the side plate 114-1 and the urging spring 118 of the side plate 114-2 is the same, the driven roller 112-2 is driven by the driving roller 1
The force urging 12-1 is the idler gears 121 and 122.
The side plate 114-1 is weaker, and skew is more likely to occur. For this reason, the operating length of the biasing spring 118 on the side plate 114-1 side is shorter than the operating length of the biasing spring 118 on the side plate 114-2 side, so that the driven roller 1
12-2 is a driving roller 112-1 with an even pressure as a whole.
So that it abuts. FIG. 3 shows a configuration in which the operating lengths of the two biasing springs 118 are changed.

On the side plate 114-2 side, the distance from the center of the hole 123 to the end 116a of the slit 116 is L2, and on the side plate 114-1 side, the distance is L1 smaller than L2. By doing so, the side plate 11
A biasing spring 118 mounted on the slit 116 on the side of the 4-1 side
Is shorter than the working length of the biasing spring 118 attached to the slit 116 on the side plate 114-2 side, and the spring force is larger.

<Second Embodiment> FIG. 4 shows another example of the structure of the urging means in the registration roller pair 112.

In the first embodiment, the driven roller 11
The urging spring 118 that directly urges the bearing 117 is used as a means for urging the drive roller 112-1 to the drive roller 112-1, but in the present embodiment, the driven roller 112-2 is attached to the drive roller 112-1. The urging lever 125 is used as the urging means.
And an urging mechanism including an urging spring 127.

The urging lever 125 has side plates 114-1 and 114-1 rotatable about a support shaft 126 in a vertical direction.
14-2. This urging lever 125
The principle of leverage is applied, and a short portion ahead of the support shaft 126 is applied to the bearing 117 from below, and a long portion behind the support shaft 126 is urged downward by an urging spring 127. One end of the biasing spring 127 is connected to the side plates 114-1 and 114-.
2, and the other end is provided with pins 125 a, 125 b, 1 provided on an urging lever 125.
25c.

Here, the side plate 114-1 and the side plate 1
The urging lever 125 and the urging spring 1 of the urging mechanism on the 14-2 side
27 uses the same parts.

In this configuration, the urging force with which the urging lever 125 urges the driven roller 112-2 changes depending on whether the urging spring 127 is applied to any of the pins 125a, 125b, and 125c. Here, the urging force of the urging lever 125 of the side plate 114-1 is applied to the urging lever 12 of the side plate 114-2.
Set greater than the biasing force of 5.

In the case of this configuration, it is possible to absorb the difference in the urging force due to the component variation of the two urging springs 127.

<Third Embodiment> FIG. 5 shows another example of the configuration of the biasing spring set portion in the registration roller pair 112.

Here, the working length of the biasing spring 118 mounted on the slit 116 can be freely adjusted.

The slit 116 is provided with a spring seat member 130 capable of sliding the slit 116 in the direction of the bearing 117. The urging spring 118 is connected to the spring seat member 13.
0 and the bearing 117.

The spring seat member 130 includes side plates 114-1 and 114-1.
14-2 is rotated by a cam member 131 rotatably mounted on a support shaft 132 as a center.
16 slides in the direction of the bearing 117.

Now, when the cam member 131 is rotated clockwise, the spring seat member 130 moves in the direction of the bearing 117, compresses the biasing spring 118, and shortens its working length. The operating length of the biasing spring 118 changes depending on the amount of movement of the spring seat member 130. When a predetermined action length is set, the screw 133
This fixes the position of the cam member 131.

When the urging force of the urging spring 118 on the side plate 114-1 side is set to be larger than the urging force of the urging spring 118 on the side plate 114-2 side, the spring seat member 130 on the side plate 114-1 side is set to the side plate. By moving more than the spring seat member 130 on the 114-2 side, the operation length of the biasing spring 118 is shortened.

In the case of this configuration, the operating length of the biasing spring 118 can be adjusted steplessly. Further, the difference in the urging force due to the variation of the parts of the two urging springs 118 can be absorbed.

The present invention is also applicable to a pair of conveying rollers for transmitting the rotational force of a sheet conveying driving roller to a sheet conveying driven roller via a gear.

[0052]

As described above, according to the present invention,
Since the urging force for urging the sheet conveyance driven roller near both ends can be set to be larger toward the side where the gear for transmitting the rotational force of the sheet conveyance driving roller to the sheet conveyance driven roller is arranged, Thus, the balance of the contact pressure between the two rollers can be maintained without the influence of the reaction force due to the driving load. Therefore, the sheet does not skew.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating the overall configuration of a laser beam printer (sheet processing apparatus) to which the present invention is applied.

FIG. 2 is a perspective view illustrating a detailed configuration of a registration roller pair (sheet conveying device) to which the present invention is applied.

FIG. 3 is a perspective view showing a configuration of an inventive part of the registration roller pair of FIG. 2;

FIG. 4 is a perspective view showing another configuration example of the urging means in the registration roller pair.

FIG. 5 is a side view showing another example of the configuration of the biasing spring set portion in the registration roller pair.

[Explanation of symbols]

 112 Registration roller pair (sheet conveyance device) 112-1 Drive roller (sheet conveyance drive roller) 112-2 Driven roller (sheet conveyance driven roller) 114-1 Side plate (first support) 114-2 Side plate (second) (Supporting body) 116 Slit (urging spring set part) 118 Urging spring 121, 122 Gear 125 Urging lever (urging mechanism) 127 Urging spring (urging mechanism) 131 Cam (spring force changing means)

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Takashi Kuwata 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Makoto Izumi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon F term (in reference) 2H072 CB05 3F049 AA02 DA19 LA02 LB03 3F102 AA06 AB02 BA02 BB02 DA08 FA02

Claims (8)

[Claims] 1. A sheet conveyance drive roller rotatably supported near both ends by a first support and a second support, and the first and second sheet conveyance drive rollers are paired with each other.
A sheet transport driven roller rotatably supported at both ends near the support by the support member and the second support member; and the sheet transport driven roller such that the sheet transport driven roller comes into contact with the sheet transport driving roller at a predetermined pressure. First and second urging springs for urging the vicinity of both ends of the roller, and the sheet conveyance driving roller and the sheet conveyance driven roller for transmitting the rotational force of the sheet conveyance driving roller to the sheet conveyance driven roller. And a pair of gears meshing at one end of the sheet conveying device, wherein the first and second urging springs use the same part. The sheet conveying device according to claim 1, wherein each of the first and second urging springs is set so that a difference occurs in a spring force when the urging spring is set. 2. The spring force when setting the first and second urging springs is set larger in the urging spring that urges the sheet conveyance driven roller on the side where the gear is arranged. The sheet conveying device according to claim 1, wherein: 3. A sheet conveying drive roller rotatably supported near both ends by a first support and a second support, and the first and second sheet conveying drive rollers forming a pair.
A sheet transport driven roller rotatably supported at both ends near the support by the support member and the second support member; and the sheet transport driven roller such that the sheet transport driven roller comes into contact with the sheet transport driving roller at a predetermined pressure. First and second urging springs for urging the vicinity of both ends of the roller; and transmitting the rotational force of the sheet conveyance driving roller to the sheet conveyance driven roller. A pair of gears meshing at one end side, and using the same component as the first and second biasing springs, wherein a spring force at the time of setting the biasing springs is provided. A sheet conveying device, characterized in that at least one of the first and second urging springs is provided with a spring force changing means for changing the spring force. 4. The spring force changing means is provided on an urging spring for urging the sheet conveyance driven roller on the side where the gear is arranged, and the spring force of the urging spring is applied to the other urging spring. The sheet conveying device according to claim 3, wherein the sheet conveying device is set to be larger than a spring force of the spring. 5. A sheet transport drive roller rotatably supported near both ends by a first support and a second support, and the first transport drive roller forming a pair with the sheet transport drive roller.
A sheet transport driven roller rotatably supported at both ends near the support by the support member and the second support member; and the sheet transport driven roller such that the sheet transport driven roller comes into contact with the sheet transport driving roller at a predetermined pressure. First and second urging means for urging the vicinity of both ends of the roller, and the sheet conveyance driving roller and the sheet conveyance driven roller for transmitting the rotational force of the sheet conveyance driving roller to the sheet conveyance driven roller. And a pair of gears meshing at one end of the sheet conveying device, wherein the first and second urging means use the same part. A sheet conveying device, wherein an urging mechanism capable of adjusting an urging force is used as the urging means. 6. The urging force of the urging means of the first and second urging means, which urges the sheet conveyance driven roller on the side where the gear is disposed, is applied by the other urging means. The sheet conveying apparatus according to claim 5, wherein the sheet conveying apparatus is set to be larger than the power. 7. A sheet processing apparatus according to claim 1, wherein said sheet processing apparatus performs predetermined processing on sheets fed one by one, as means for conveying a sheet to a predetermined position. A sheet processing apparatus comprising: 8. A sheet processing apparatus for performing a predetermined process on sheets fed one by one, as means for correcting a skew state of a moving sheet.
A sheet processing apparatus comprising the sheet conveying apparatus according to claim 1.