JP2891558B2 - 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 sheet conveying device provided in an image forming apparatus such as a copying machine, a printer, a laser beam printer, and a facsimile.

[0002]

2. Description of the Related Art FIG. 10 shows an example of the configuration of a conventional laser beam printer as an image forming apparatus. In FIG. 1, reference numeral 101 denotes a paper storage cassette, which is a loading table 1 that is stored in a cassette body 102 and loads paper P thereon.
03, and a pressure spring 106 for urging the loaded paper P against the feed roller 105. Reference numeral 107 denotes a separating unit, which includes a friction member 109 and the feeding roller 1.
And a pressurizing spring 110 for pressurizing the pressurized portion 05.

A feed roller 105 is supported by a drive shaft 105a, and a driven gear 1 is attached to an end of the drive shaft 105a.
11 and an electromagnetic clutch 112 are pivotally supported. Sign 1
Reference numeral 13 denotes a pair of registration rollers, which includes a conveying roller 115 made of a friction member, a driven roller 116, and the driven roller 1.
The elastic member 117 urges the conveying roller 115 against the conveying roller 115. Reference numeral 119 denotes detection means for detecting the leading end of the conveyed sheet P. A sheet transport path 121 composed of guide plates 121a and 121b is provided between the feeding means 120 including the feeding roller 105 and the registration roller pair 113, and a guide sheet 122a and 122b is provided between the registration roller pair 113 and the detection means 119. Paper transport path 122 is formed.

A gear 123 is supported by a drive shaft 115a of the transport roller 115, and is connected to a drive source M via a gear train (not shown). The gear 123 is connected to the driven gear 111 via idle gears 125 and 126.

Now, when power is supplied to the electromagnetic clutch 112,
The drive of the driven gear 111 is connected to the drive shaft 105a, and the feed roller 105 starts rotating in the direction of the arrow. Thereby, the upper paper P in the paper storage cassette 101 is fed,
After the sheets are separated one by one by the separating action of the separating unit 107, they reach the registration roller pair 113 along the transport path 121. When the detection unit 119 detects the leading end of the sheet P conveyed by the registration roller pair 113, the driving from the driving source M is stopped, and the sheet P is stopped.
Stops moving.

After a certain period of time, the driving source M is restarted, and the paper P is further transported. The electromagnetic clutch 112 is restarted, and the paper P is further transported. Electromagnetic clutch 11
2 is that the leading edge of the sheet is at least
Until it reaches the next sheet P at the latest.
Electric power is supplied until 5 contacts.

[0007]

However, in the above-described conventional apparatus, the distance from the pair of registration rollers 113 to the feeding means 120 is long, and the driving from the pair of registration rollers 113 to the feeding roller 105 is performed. There is a problem that the number of gears for transmitting the gear increases. Further, there is a problem that the paper storage cassette 101 extends from the apparatus main body and the installation space of the apparatus is large.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a paper transport apparatus in which the number of gears for driving a feed roller and a transport roller is reduced and a paper storage cassette can be stored in the apparatus main body. It is.

[0009]

SUMMARY OF THE INVENTION According to the present invention, there is provided a feed roller having a feed roller for feeding sheets stacked and stored in a sheet storage cassette one by one, and a drive control mechanism for controlling the rotation of the feed roller. Feeding means, a feeding means comprising a pair of feeding rollers sequentially arranged downstream of the feeding roller in the direction of feeding the sheet and feeding the sheet fed by the feeding roller; and U-turn conveyance path for paper guide constituted by means and the conveyance means, a driven gear rotatably supported by a drive shaft of a feeding roller of the feeding means, and a drive shaft of a conveyance roller pair of the conveyance means The driven gear, which is rotatably supported by the feed roller, is always meshed with the driven gear of the feed roller and the driven gear of the transport roller pair, and the rotational drive transmitted by the drive source is driven by the driven gear of the feed roller and the transport roller pair. I will transmit it to the driven gear and rotate it. It is characterized in that it has a main gear provided, to.

According to the present invention, the rotation and stop of the feed roller are controlled by connecting and disconnecting a driven gear of the feed roller and a drive shaft of the feed roller by the drive control mechanism. It is characterized by the following.
Further, the invention is characterized in that the transport roller pair is a pair of skew feeding rollers including a driving roller formed of a friction member and a skew feeding roller pressed by an elastic member against the driving roller.

Further, the present invention is characterized in that it has a conveyance port through which the paper conveyed by another feeding means can join in the U-turn conveyance path. Also, the present invention provides a sheet detecting means which is disposed at the most downstream side of the U-turn conveyance path and detects the leading edge of the sheet, and stops driving of the drive source by a detection signal from the sheet detecting means, and Registration control means for restarting the drive source after a time,
It is characterized by having.

[0012]

According to the above construction, the main gear is always meshed with the driven gear supported by the drive shaft of the feed roller and the driven gear supported by the drive shaft of the pair of transfer rollers of the transfer means, and transmitted by the drive source. The rotation drive is transmitted to the driven gear of the feed roller and the driven gear of the conveying roller pair via the main gear to rotate. Further, while a U-turn conveyance path for paper guide is constituted by the feeding means and the conveying means, the rotation of the feeding roller is controlled by a drive control mechanism of the feeding means, and the feeding roller and the conveying roller pair are used. The paper is transported along the U-turn transport path.

[0013]

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS.

[First Embodiment] In FIG. 1, a paper loading device 6 provided in an apparatus main body 8 includes a loading table (paper storage cassette) 2 on which paper P is loaded.
And an elastic member 5 for urging the sheet P against a feeding roller described later. The feeding means 1 is supported by the drive shaft 3a and rotates in the direction of the arrow to feed the paper P on the loading table 2, and separates the fed paper P one by one. And separating means 10. This separation means 1
0 denotes a friction member 7 for separating the paper P, and the friction member 7
And an elastic member 9 for urging the feed roller 3 against the feed roller 3.

A driven gear 1 is provided at one end of the drive shaft 3a.
1 and an electromagnetic clutch 12 are provided. When the electromagnetic clutch 12 is turned on / off, the driven gear 11
The drive can be connected to and released from a.

Downstream of the feeding means 1, a first conveying means 13 is provided. The first transporting means 13 is composed of a roller 15 and a driven gear 16 formed of a friction member supported by a support shaft 15a, and a driven roller 19 urged against the roller 15 by an elastic member 17. I have. On the downstream side of the first transporting means 13, the second transporting means 2
0 is provided. The second conveying means 20 is composed of a roller 21 composed of a friction member supported by a support shaft 21a, a driven gear 22, and a driven roller 25 urged against the roller 21 by an elastic member 23. ing.

On the downstream side of the second transport means 20, a paper transport path 30 composed of guide plates 30a and 30b is formed. In the vicinity of the second transport means 20 in the paper transport path 30, a transport path is provided. A sheet detecting means 26 comprising a photo interrupter for detecting the leading end of the sheet P to be printed is provided.

Between the feeding means 1 and the first conveying means 13,
A sheet transport path 27 is formed by guide plates 27a and 27b for guiding the sheet P, and the first transport unit 13
And a guide plate 29a provided between the
The paper transport path 29 is formed by 29b. Guide plates 27a, 27b, 29a, 29b, 30a, 30b formed over the feeding means 1 and the second conveying means 20
Thus, U-shaped paper transport paths 27, 29, and 30 are formed.

A main gear 31 is connected to the drive source M via a gear train (not shown), and the driven gears 11, 16, and 22 are respectively disposed so as to mesh with the main gear 31. Have been. The rotation of the main gear 31 in the direction of the arrow causes the gears 11, 16, and 22 to rotate in the same direction indicated by the arrow. Also, the feeding roller 3
The number of teeth of the gears 11, 16 and 22 is determined so that the peripheral speed of the gears 11 and 16 and the peripheral speed of the two rollers 15 and 21 are equal.

Next, the operation of the above-mentioned paper conveying apparatus will be described with reference to FIGS. In FIG. 2, it is assumed that the electromagnetic clutch 12 is not energized, and the driven gear 11 can freely rotate with respect to the drive shaft 3a.
When the drive source M is driven, the drive is transmitted to the main gear 31 and the drive is further transmitted to the driven gears 11, 16, and 22. At this time, even if the driven gear 11 rotates, the driving force is not transmitted to the drive shaft 3a, so that the feeding roller 3 does not rotate. Since the drive is transmitted to the two support shafts 15a and 21a, the rollers 15 and 21 are respectively rotating.

Here, when the electromagnetic clutch 12 is energized,
The drive of the driven gear 11 is transmitted to the drive shaft 3a, and the feed roller 3 rotates in the direction of the arrow. Then, the upper sheets loaded on the sheet loading device 6 are fed, and only the uppermost sheet P1 is separated by the separating means 10 and enters the sheet transport path 27 (see FIG. 3). Further, the sheet P1 advances to the sheet conveying paths 29 and 30 by the conveying force of the feeding roller 3, the first conveying unit 13 and the second conveying unit 20, but the electromagnetic clutch 12 moves the sheet P1. Electricity is supplied until the leading edge of the sheet P passes through the first conveying means 13 even if it is fast, or until the feed roller 3 comes into contact with the next sheet P even if it is late.

When the leading end of the sheet P1 is detected by the sheet detecting means 26, the driving source M is stopped, the rotation of each roller is stopped, and the sheet P1 temporarily waits (see FIG. 4). After a certain time from the stop, the driving source M is restarted under the control of the registration control means 4, and the sheet P1 is further conveyed.
In this way, the paper P is fed one by one at a time.

[Embodiment 2] FIG. 5 shows a second embodiment of the present invention. In the first embodiment, the paper P is loaded on the loading table 2 in the apparatus main body 8. However, the paper P may be loaded on the cassette 33 that is detachable from the apparatus main body 8 as shown in FIG. Good. Here, reference numeral 35 denotes a cassette main body, and the loading table 37 housed in the cassette body is urged by a pressure spring 36 to urge the sheet P to the feed roller 3.

[Embodiment 3] The feeding means of the first embodiment includes:
Although the paper feeding method uses the friction separation method, the separation of the sheet P may be a nail separation method as shown in FIG. Separating claws 40 come into contact with both corners of the sheet P to separate the uppermost sheet P1 when the sheet P is fed. The cross section of the feeding roller 41 is a half-moon shape. Further, the driven roller 19 of the first transport unit 42 and the driven roller 25 of the second transport unit 43
May be a skew feeding roller arranged such that its rotation axis is oblique to the driving side rollers 15 and 21. One rotation of the feed roller 41 is controlled by the drive control means 12 provided on the drive shaft 41a. At this time, the arc length of the feeding roller 41 is set to be sufficiently longer than the distance from the leading end of the sheet P to the first conveying means 42.

Embodiment 4 FIG. 7 shows a fourth embodiment of the present invention. In the figure, a sheet transport path 27 between a feed roller 3 and a first transport unit 13 and a first transport unit 13 and a second transport unit 20
A sheet feeding path 27 through which sheets P2 and P3 fed from another feeding means (not shown) can be merged.
c and 29c are provided so as to be merged. Thus, paper can be fed from a plurality of paper stacking units.

[Embodiment 5] In the first embodiment, the drive control mechanism of the feed roller 3 is performed by the electromagnetic clutch 12, but this is performed by using a solenoid 50 and a spring clutch 51 as shown in FIG. Configuration may be used. In the figure, since the actuator 50a of the solenoid 50 locks the claw 52a of the control ring 52 constituting the spring clutch 51,
The feed roller 3 is idle. Solenoid 5
0 for a moment, the actuator 50a
The drive shaft 3a is rotated by deviating from the position a, and the feed roller 3 starts rotating. Feed roller 3
When just one rotation is made, the actuator 50a
By locking a, the feed roller 3 stops.

Also, as shown in FIG.
The feed roller 3 may be controlled by providing a notch 11a in a part of the driven gear 11 using a spring 59 having one end locked to a pin 57 of the control ring 56. The driven gear 11 is integrally formed with a claw portion 56a and a pin 57, and the solenoid 50
Actuator 50a locks the claw portion 56a. One end of the spring 59 is engaged with the pin 57 and the other end of the spring 59 is urged to rotate the feed roller 3 in the direction of the arrow.

The driven gear 11 has some teeth cut out, and maintains a state in which the driven gear 11 does not mesh with the main gear 31 as shown in the figure. Then, when the solenoid 50 is momentarily energized, the actuator 50a separates from the claw portion 56a, and the driven gear 11 is slightly rotated in the direction of the arrow by the urging force of the spring 59. This rotation causes the notch 11a of the driven gear 11 to move, so that the driven gear 11 meshes with the main gear 31 and the drive of the main gear 31 is transmitted. Driven gear 11
Is rotated once, the claw 56a is stopped by the actuator 50a.

[0030]

As described above, according to the present invention,
The feed roller for feeding the stacked sheets and the rollers of a plurality of conveying means on the downstream side can be rotated by one main gear connected to the driving source. Since the number of gears for transmitting the driving force to the means is reduced, the cost can be reduced and the device can be made compact.

Further, by providing the U-turn conveyance path with a feed port that joins from another feeding means, it is easy to connect a paper path from another feeding means (circumscribing, manual feeding, etc.). Further, since a plurality of transport means can be arranged in the U-turn transport path, the paper storage cassette can be stored in the apparatus main body, and the installation area of the apparatus main body can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view showing a first embodiment of the present invention.

FIG. 2 is an operation diagram.

FIG. 3 is an operation diagram.

FIG. 4 is an operation diagram.

FIG. 5 is a longitudinal sectional side view of a sheet conveying device according to a second embodiment of the present invention.

FIG. 6 is a vertical sectional side view of a sheet conveying device according to a third embodiment of the present invention.

FIG. 7 is a vertical sectional side view of a sheet conveying device according to a fourth embodiment of the present invention.

FIG. 8 is a vertical sectional side view of a sheet conveying device according to a fifth embodiment of the present invention.

FIG. 9 is a vertical sectional side view showing a modification of the apparatus shown in FIG. 8;

FIG. 10 is a vertical sectional side view of a sheet conveying device showing an example of a conventional sheet conveying device.

[Explanation of symbols]

 P, P1, P2 Paper 1 Feeding means 2 Loading table 3 Feeding roller 3a Drive shaft 4 Registration control means 8 Apparatus main body 11 Drive gear 12 Drive control mechanism (electromagnetic clutch) 13 First transport means 15 Drive roller 16 Drive gear Reference Signs List 19 driven roller (or skew feeding roller) 20 second conveying means 21 drive roller 22 driven gear 25 driven roller (or skew feeding roller) 27, 29, 30 U-turn conveyance path 31 main gear

Claims (5)

(57) [Claims] A feed roller having a feed roller for feeding sheets stored in a sheet storage cassette one by one, and a drive control mechanism for controlling rotation of the feed roller; and the feed roller. configuration and conveying means having a conveying roller pair on the downstream side are sequentially arranged for conveying the fed sheet by the feeding roller by said transfer means and said feeding means the direction for feeding the paper a U-turn conveying path for the paper guide which is a driven gear which is rotatably supported by the drive shaft of the feed roller of the feeding means, and a driven gear which is rotatably supported by the drive shaft of the conveying roller pair of the conveying means , The driven gear of the feed roller and the driven roller pair
The gear is always meshed with the gear, and the rotational drive transmitted by the drive source is
The driven gear of the feed roller and the driven gear of the conveying roller pair
And a main gear provided so as to be transmitted to and rotated by the sheet feeding device. 2. The method according to claim 1 , wherein the rotation and stop of the feed roller are performed by
A driven gear of the feed roller and the feed roller are driven by a drive control mechanism.
By connecting and disconnecting the feed roller drive shaft
2. The paper transport device according to claim 1, wherein the paper transport device is controlled.
Place. 3. The conveyance roller pair according to claim 1, wherein the conveyance roller pair is a skew feeding roller pair including a driving roller formed of a friction member and a skew feeding roller pressed by an elastic member against the driving roller. Paper transport device. 4. The sheet conveying apparatus according to claim 1, further comprising a conveying port through which the sheets conveyed by another feeding unit can join in the U-turn conveying path. 5. A sheet detecting means disposed at the most downstream side of the U-turn conveyance path for detecting the leading edge of a sheet, and the drive of the driving source is stopped by a detection signal from the sheet detecting means, 2. The sheet conveying device according to claim 1, further comprising: a registration control unit that restarts the driving source after a lapse of time.