JPS62244846A - Paper feeding device - Google Patents

Abstract

PURPOSE:To make a load applied to a resist roller uniform and stabilize paper feeding by rotating a relay roller in such a way that the deflection of a sheet of paper at the part between said resist roller and said relay roller may not be removed, when feeding said sheet of paper by means of said resist roller. CONSTITUTION:By operating a resist roller driving means and a relay roller driving means, a resist roller 2 and a relay roller 6a are rotated in the arrow directions, to feed a sheet of paper P toward and image forming device. In this case, the relay roller driving means rotates the relay roller 6a at a peripheral speed such that the deflection of a sheet of paper P at the part in between the relay roller 6a and the resist roller 2 may not be removed. Accordingly, since a deflection is always formed on the paper P at the part in between the resist roller 2 and the relay roller 6a, load which is applied to the resist roller 2 can be constant when feeding whichever sheet of paper P, stabilizing the feeding of the sheet of paper.

Description

TECHNICAL FIELD The present invention relates to a paper feeding device that fully feeds paper in an image recording apparatus such as an electronic copying machine or a printer.

PRIOR ART Conventionally, an image recording apparatus includes a pair of registration rollers for feeding a sheet IIi at a predetermined speed toward the image forming apparatus based on a paper refeeding signal from the image forming apparatus, and the image recording apparatus. A paper feed roller with power distributed to each of the paper feed ports for selectively feeding sheets of different sizes one by one through the plurality of paper feed ports formed on the exterior plate of the apparatus, and each of the paper feed ports described above. a guide plate for forming a paper feeding path for each of the above-mentioned sheets, which guides each of the sheets selectively fed through the opening toward the above-mentioned registration roller; A paper feeding device is known that has at least a pair of relay rollers disposed in a paper feeding path whose distance is longer than the length of the paper to be fed and for preventing the paper from stagnation in the middle of the paper feeding path. There is.

However, in the conventional paper feeding device, the paper feeding speeds of the paper feeding roller, relay roller, and registration roller are set to be the same, and after the registration roller starts refeeding the paper, The paper feed roller and relay roller were configured to cut off the driving of the paper feed roller and the relay roller, and rotate the paper feed roller and the relay roller together with the fed paper, so the load applied to the registration roller was increased depending on the number of relay rollers and the relay roller. There has been a drawback that irregular slips occur between the registration rollers and the paper being fed, depending on the presence or absence of the paper, making feeding of the paper by the registration rollers unstable.

OBJECTS An object of the present invention is to provide a paper feeding device that can stabilize the feeding of paper by equalizing the load applied to the registration rollers.

Structure The present invention provides a paper feed roller that feeds paper stored in a paper feed cassette, at least one pair of relay rollers that transports the paper fed by the paper feed roller, and these relay rollers. A pair of registration rollers are provided that stop the leading edge of the paper being conveyed, temporarily standby the paper in a bent state, and then feed the paper toward the image forming device of the image recording device. In this paper feeding device, the paper 1 is fed by rotating the relay roller so that the paper does not become deflected between the registration roller and the relay roller when the paper is fed by the registration roller.

Next, embodiments of the present invention will be described in detail based on the drawings.

In FIG. 1, a paper feed section 1aK of an electronic copying machine 1, which is one of the image recording devices, includes a pair of registration rollers 2, a paper feed roller 3, a guide plate 4, a paper sensor 5, and two pairs of relay rollers 6a and 6b. are placed respectively.

The registration roller 2 includes a photoconductor (not shown), a cleaning tube, a charging device, an exposure device, a display device, a transfer device, a paper separation device, a fixing device, etc. arranged around the photoconductor. Paper P toward the device
to be delivered. The registration rollers 2 are driven by the registration roller driving means 91C when the output of the paper refeeding signal output means 7 is applied to the registration roller control means 8. The paper refeeding signal output means 7 outputs a paper refeeding signal when the original image formed on the photoreceptor corresponds to a predetermined position on the paper P. The registration roller driving means 9 is configured using, for example, a stepping motor. and a transmission gear for transmitting the rotation of the stepping motor to the registration roller 2. Rotate in the direction of the arrow. Further, the registration roller control means 8 turns ON or OFF a registration roller clutch, which connects and disconnects the rotation transmission function of the stepping motor or the transmission gear, at a predetermined timing based on the image forming signal.

The operation of the registration roller driving means 9 is controlled.

The paper feed ports 23 are arranged in the vicinity of a plurality of paper feed ports 1c formed on the exterior plate 1b of the electronic copying machine 1 for each of the paper feed ports 1c. Each of these paper feed rollers 3 is in contact with a paper P in a paper feed cassette 10 that is detachably attached to each of the paper feed ports 1c. Further, each paper feed port 23 is driven by each paper feed roller drive means 13 by applying the output of the paper feed signal output means 11 to the paper feed roller control means 12. The paper feed signal output means 11 outputs a paper feed signal in response to a print signal from a print key 15 disposed on the operation panel 14 of the electronic copying machine 1, for example. Further, each of the above-mentioned paper feed roller drive means 13 drives the main motor and the rotation of this main motor to each of the paper feed rollers 3.
The paper feed rollers 3 are each rotated in the direction of the arrow at a circumferential speed faster than the circumferential speed of the registration rollers 2.

The paper feed roller control means 12 controls a paper feed roller clutch that connects and disconnects the rotation transmission function of the main motor or its transmission gear according to the size of each paper P based on the paper feed signal and the pawl detection signal. ON or 0FFJ at the same timing to selectively control the operation Tbb of each of the paper feed rollers [moving means 13]. Here, the paper feed roller control means 12 receives a cassette selection signal from a plurality of cassette selection keys 16 for selecting the paper feed cassette 10 arranged on the operation panel 14, Paper feed roller drive means 13 corresponding to the selected paper feed cassette 10 among the paper feed roller drive means 13 of
control to operate only.

The guide plate 4 forms a paper feed path 4a for each paper to guide the paper P1ft selectively fed by each of the paper feed rollers 3 toward the registration rollers 2.

The paper sensor 5 is disposed on the guide plate 4 just before the upstream side of the registration roller 2, and detects the paper P'lk selected and fed along the paper feed path to generate a paper detection signal. Output.

Each of the above-mentioned relay rollers 6a, 6b is connected to each of the above-mentioned paper feed paths 4.
The sheets are distributed to the sheet feeding path 4a, where the sheet feeding distance of a is longer than the length of the sheet P to be fed. The relay roller 6a includes the relay roller 6a, the registration roller 2, and the paper feed roller 3 at the third stage from the top in FIG.
and the other relay roller 6b are arranged so that the length of the paper feed path 4a is shorter than the length of the paper P fed from the third paper feed cassette 10 from the top in FIG. It's haha. Further, the relay roller 6b is the relay roller 6b.
The length of the paper feed path 4a between the paper feed roller 3 and the other relay rollers 6a at the lowest stage in FIG. It is arranged so that it is shorter than its length. In addition,
In the illustrated example, the length of the paper P in the third paper feed cassette 10 is set in advance to be shorter than the length of the paper P in the bottom paper feed cassette 10. Further, each paper feed path 4a in the upstream portion of the registration roller 2 and the upstream portion of the relay roller 6a has a
A deflection allowance section 4 for allowing the deflection of the paper P within the
b are respectively formed by the guide plate 4.

The relay roller 6a is driven by the relay roller drive means 18 by applying the output of the paper feed signal output means 11 to the relay roller control means 17. The relay roller driving means 18 is configured in substantially the same manner as the paper feeding roller driving means 13, and rotates the relay roller 6a in the direction of the arrow at a circumferential speed substantially equal to the circumferential speed of the paper feeding roller 3.

Further, the relay roller control means 17 performs control at a predetermined timing based on the relay roller drive means 18t, the paper feed signal, the paper detection signal, and the paper refeed signal.

On the other hand, the relay roller 6b is connected to the paper feed signal output means 1.
When the output of 1 is given to the relay roller control means 19, the relay roller driving means 20 is driven. The relay roller enrichment means 20 is configured in substantially the same manner as the other relay roller driving means 18, and rotates the relay roller 6be in the direction of the arrow at a circumferential speed that is substantially the same as the circumferential speed of the paper feed roller 3. . Further, the relay roller control means 19 controls the relay roller drive means 20 at a predetermined timing based on the paper feed signal and the paper detection signal.

The operation of the paper feeding device configured as described above will now be described.

In FIG. 1, when a main switch (not shown) of an electronic copying machine 1 is turned on, the image forming device is set to an operable state. Next, one of the cassette selection keys 16 is turned on by the operator to select the type of paper P to be fed. At this point, the cassette selection key 16 is turned on so as to feed the paper P in the top row in FIG.
If so, first, via the paper feed roller control means 12, only the paper feed roller drive means 13 that drives the paper feed roller 3 corresponding to the paper P in the uppermost stage is set to an operable state. When the print key 15 is turned on in this state, a print signal is given to the paper feed signal output means 11, and the paper feed signal output means 11 outputs a paper feed signal at a predetermined timing. By applying this paper feed signal to the paper feed roller control means 12, only the paper feed roller 3 corresponding to the paper P in the uppermost stage is moved through the paper feed roller drive means 13ft as shown in the arrow in FIG. The paper P is rotated in the direction shown in FIG. Note that when the cassette selection key 16 is turned on so as to feed the paper P in the uppermost stage as described above, the paper feed signal output means 1
A paper feed signal and a paper refeed signal to be described later are not given to each of the relay roller control means 17 and 19 from 1 to 19 described above.

Therefore, in this case, each of the above-mentioned relay rollers 6a.

6b is not driven, and even if another sheet P remains in another sheet feeding path 4a, this sheet will not be fed by mistake. By the way, when the leading edge of the paper P fed as described above is detected by the paper sensor 5, the paper detection signal is given to the paper feed roller control means 12, and this paper detection signal is output. After a period of time ta has elapsed from this point, the operation of the paper feed roller driving means 13 is stopped. Therefore, the paper P is further fed for a waiting time of ta with its leading edge in contact with the nip portion of the registration roller 2, and, for example, as shown in the 218th (l), the deflection permitting portion 4b of the paper feeding path 4a is A deflection is formed within.

The above-mentioned time ta is set in advance by a timer or the like at a time required for the paper P to be sufficiently bent and for the trailing edge of the paper P to reach a position immediately before coming off the paper feed roller 3. is set by.

Meanwhile, while the above-described operation is being executed, the image forming device is operated based on the print signal, and a document $rJ@ (not shown) is formed on the photoreceptor through a predetermined image forming process. When the position of this image on the photoreceptor corresponds to a predetermined position on the paper P, the paper refeed signal output means 7 outputs a paper refeed signal. As a result, the registration roller movement means 9 is operated via the registration roller control means 8t, and the registration roller 2
The paper P is rotated in the direction of the arrow as shown in the third column, and the paper P is fed toward the above-mentioned gapping device.

Next, when the cassette selection key 16 is turned on to feed the second stage paper Pft in FIG. 1, only the second stage paper feed roller driving means 13 becomes operable. Set. The above paper P is the top paper P.
The sheet is fed in substantially the same manner as described above, and the operation of the sheet feeding roller drive means 13 is stopped after a period of time tb has elapsed since the sheet detection signal was output. The above-mentioned time tb is set in advance in substantially the same manner as the above-mentioned time ta. The paper P on the second stage is fed toward the image forming device by the registration roller 2 at the same timing as the paper P on the top stage. The registration roller driving means 9 starts driving the registration rollers 2 after a time period te has elapsed since the trailing edge of the paper P is out of the detection area of the paper sensor 5 and the paper detection signal is cut off. is stopped by ceasing the operation of.

Next, when the cassette selection key 16 is turned on to feed the paper P in the third stage in FIG. is set to When the print key 15 is turned on in this state, the paper feed signal output means 11 gives a paper feed signal to the paper feed roller control means 12 and the relay roller control means 17. As a result, only the paper feed roller 3 and the relay roller 6a of the third stage are moved to the fourth stage via the paper feed roller ground movement means 13 and the relay roller drive means 18.
As shown in the figure, the paper P in the third stage is fed by rotating in the arrow directions at predetermined timings. When the leading edge of the paper P is detected by the paper sensor 5, the operation of the relay roller driving means 8 is stopped after a time td has elapsed since the paper detection signal was output from the paper sensor 5. Ru. As a result of kneading, the paper P in the third tier is deflected within the deflection allowing section 4b, similar to the case with the paper P in the top and second tiers of fmE. Note that the operation of the third-stage paper feed roller jIcyIh means 13 is stopped when the rear end of the paper P reaches a position immediately before it comes off the paper feed roller 3. This prevents the subsequent paper P from being fed. Next, when a paper refeed signal is output from the paper refeed signal output means 7, the registration roller drive means 9 and the relay roller drive means 18 are respectively activated, and the registration rollers 2 and relay rollers 6a are moved as shown in FIG. 8g5. As shown, the paper P is rotated in the direction of the arrow and fed toward the image forming device. At this time, the relay roller driving means 18 moves the paper P between the relay roller 6a and the registration roller 2.
The relay roller 6a is rotated at a circumferential speed that does not eliminate deflection.

Next, when the cassette selection key 16 is turned on to feed the paper P at the bottom of the first cause, only the paper feed roller driving means 13 at the bottom is set to an operable state. . When the print key 15 is turned on in this state, the paper feed signal output means 11 gives a paper feed signal to the paper feed roller control means 12 and each relay roller control means 17, 19, respectively. Due to this busy state, the lowermost paper feed roller 3 and each relay roller 6a, 5b are
As shown in FIG. 6, the paper P is fed by rotating in the arrow directions at predetermined timings via the paper feeding roller driving means 13, each relay roller, and the feeding means 18, 20. Incidentally, here, the operation start timing of each of the relay rollers 6a, 6b is set at a time of 11.5 seconds with respect to the operation start timing of the paper feed roller 3. By delaying the paper P by t2, the leading edge of the paper P fed by the paper feed roller 3 is first brought into contact with the nip portion of the stopped relay roller 6b to correct the skinny of the paper P, and then the paper P is The paper P is fed by the relay roller 6b, and its leading end is brought into contact with the nip portion of the stopped relay roller 6a.
skinny can be re-corrected.

On the other hand, when the leading edge of the paper P is detected by the paper sensor 5, the operation of the relay roller driving means 18 is stopped after a time period t has elapsed since the paper detection signal was output from the paper sensor 5. Further, after a time period t' has elapsed since the paper sensor 5 detected the paper P, the operation of the relay roller l mover stage 20 is stopped. As a result, the leading edge of the paper P is first brought into contact with the nip portion of the registration roller 2 as shown in the sixth factor, and the paper P is further fed by the relay rollers 6a and 6b for the time t. and the above registration roller 2.
The leading edge of the paper P is deflected within the upstream deflection allowing section 4b.

Next, with the relay roller 6a stopped driving, the paper P is further fed by the relay roller 6b for the time t/·-t·, and is fed within the deflection allowance section 4b on the upstream side of the relay roller 4a. The trailing edge of the paper P is also bent. Note that the operation of the lowermost paper feed roller driving means 13 is stopped when the rear end of the paper P reaches a position immediately before it comes off the paper feed roller 3.

Next, when a paper refeeding signal is output from the paper refeeding signal output means, the registration roller driving means 9 and the relay roller driving means 18 are respectively activated, and the registration roller 2 and the relay roller 6a are activated as the seventh cause. As shown, the paper P is rotated in the directions of the arrows and fed toward the image forming device.

Note that at this time, the relay roller driving means 18 drives the relay roller 6 as in the case of feeding the paper P in the third stage.
The relay roller 6at- is rotated at a circumferential speed such that the deflection of the paper P does not disappear between the registration roller 2 and the registration roller 2a.

Therefore, the registration roller 2 and the relay roller 6
Since a deflection is always formed on the paper P between a and a,
The load applied to the registration roller 2 is constant no matter which paper P is being fed, and the feeding of that paper is stable.

In addition, each of the above-mentioned paper feed rollers 3 and each relay roller 6a,
By setting the circumferential speed of each of the paper sheets 6b to an appropriate circumferential speed, the feeding time of each paper P to the registration roller 2 can be made uniform. Further, the relay roller 6a may be rotated intermittently when the registration roller 2 is feeding the paper P.

The paper feeding device of the present invention can uniformize the load applied to the registration rollers, thereby stabilizing the feeding of the paper.

[Brief explanation of drawings]

The first factor is a schematic diagram showing the paper feeding device of the present invention, and FIGS. 2 to 7 are schematic diagrams showing the paper feeding device expanded to explain the operation of the paper feeding device. . 2... Registration roller, 3... Paper feed roller. 5...Paper sensor, 6a, 6b...Relay roller, 8
. . . Registration roller control means, 9 . . . Registration roller drive means, 12 . . . Paper feed roller control means, 13 .
・Paper feed roller drive means, 17.19... Relay roller control means, 18.20... Relay roller drive means

Claims (1)

[Claims] A paper feed roller that feeds the paper stored inside the paper feed cassette, at least one pair of relay rollers that transport the paper fed by the paper feed roller, and the paper that is transported by these relay rollers. In a paper feeding device comprising a pair of registration rollers that temporarily stand by with the leading end of the paper stopped and bent, and then feed the paper toward an image forming device of an image recording device. . A paper feeding device, characterized in that when the paper is fed by the registration roller, the relay roller is rotated to convey the paper so that the paper does not become deflected between the registration roller and the relay roller.