JP2889351B2 - Double-sided paper feeder - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double-sided paper feeding apparatus for supplying paper to a double-sided copying apparatus that performs double-sided copying on copy paper (hereinafter, referred to as paper).

[Conventional technology]

FIG. 12 is a configuration diagram of a conventionally known copying machine to which the present invention is applied, and FIG. 13 is a configuration diagram of the same double-sided paper feeding device. The single-sided copied paper switched to the apparatus 3 passes through the transport path and is sent to the intermediate tray 17 by the paper feed roller 22. The sheet stored in the intermediate tray 17 is positioned by the push plate 35 and the side plate 36.

When refeeding the paper, the bottom plate 33 is raised, the paper is pressed against the paper feed roller 22, and the separation roller 23
This is done by being separated and sent out one by one.

FIG. 14 is a configuration diagram centering on the paper feed roller portion,
When the paper is stored in the intermediate tray 17, the paper feed roller 22 rotates clockwise (in the direction of the white arrow), moves the paper in the direction of the arrow a indicated by the solid line, and discharges the paper onto the bottom plate 33. At this time, the separation roller 23 rotates together with the paper feed roller 22 (in the direction of the white arrow).

On the other hand, at the time of re-feeding, the bottom plate 33 rises to the position indicated by the broken line, and presses the uppermost sheet of the sheet bundle against the sheet feeding roller 22. Thereafter, the paper feed roller 22 rotates in the counterclockwise direction (the direction indicated by the black arrow), and feeds the sheet in the direction of the arrow b indicated by the broken line. Here, the separation roller 23 has a one-way clutch, and is kept stopped when the sheet feeding roller 22 rotates in the counterclockwise direction, so that the sheets are separated one by one. In addition, paper feed roller
The guide plate 32 and the upper guide piece 21 provided so as to face the sheet 22 form a sheet re-feeding conveyance path.

As mentioned above, when copying on both sides of the paper,
The single-sided copied paper is 1) fed into the intermediate tray 17 by the paper feed roller 22 and the separation roller 23 (the bottom plate 33 is lower), and 2) positioned by the push plate 35 and the side plate 36 (the bottom plate 33 is 3) The bottom plate 33 is raised and abutted against the paper feed roller 22, and 4) the paper is fed out by the paper feed roller 22 and the separation roller 23.

By the way, curled paper is liable to be generated by fixing on one-sided copied paper. When the curled paper is stored in the intermediate tray 17, the trailing edge of the paper floats, and the leading edge of the paper to be stored next is caught in this part, causing jam. Cause a misfeed when re-feeding.

Therefore, a paper pressing member rotatably attached to a paper feed roller shaft or a support shaft provided in the vicinity thereof has conventionally been provided. FIG. 15 is a view showing the paper pressing member 2, in which the paper pressing member 2 is rotatably provided on the shaft of the paper feed roller 22, and the tip portion is curved. Further, in the conventional double-sided copying apparatus, the trailing edge of the single-sided copied paper is stuck on the guide plate without being removed even when it is released from the paper feed roller pair during stacking, and the next sheet hits the trailing edge of the sheet to cause a stack failure. I also did things.

Therefore, a technique described in Japanese Patent Application Laid-Open No. 63-154541 has been proposed and is shown in FIG.

FIG. 16 is a longitudinal sectional view showing a schematic configuration of a sheet feeding roller portion, FIG. 17 is a longitudinal sectional view showing a schematic configuration of an auxiliary roller portion, and FIG. FIG. 19 is an explanatory view showing a state of the leading end of the sheet fed from the roller, and FIG. 19 is an explanatory view showing a state of the sheet being fed from the intermediate tray.

In these figures, A is a paper feed roller shaft, and a paper feed roller 22 is integrally provided substantially at the center. Reference numeral 23 denotes a separation roller, which is attached to an arm (not shown) and
Is pressed against the paper feed roller 22. A line connecting both axes of the roller pair including the paper feed roller 22 and the separation roller 23 is inclined. The separation roller 23 is provided with a drive system (not shown).
Numeral 23 is driven by the feed roller 22 in the direction of the arrow in FIG. 16, but rotates in the direction opposite to the direction of the arrow when feeding. Reference numeral 4 denotes an auxiliary roller.
The auxiliary roller 4 is provided symmetrically with respect to the paper feed roller 22, and the diameter of the auxiliary roller 4 is set equal to or slightly smaller than the diameter of the paper feed roller 22. Reference numeral 32 denotes a guide plate, on which the elastic pieces 6 are integrally fixed. Reference numeral 17 denotes an intermediate tray, and reference numeral 33 denotes a bottom plate. The bottom plate 33 moves up and down, and presses against the feed roller 22 to generate a feed pressure.

The operation of the two-sided copying apparatus proposed in Japanese Patent Application Laid-Open No. 63-154541 will be described. A sheet is fed along the conveyance path 9 toward the paper feed roller 22. Next, the paper is fed
22, is fed into the intermediate tray 17 by the rotation of the separation roller 23. Here, the separation roller 23 is disposed on the wall surface 7a of the intermediate tray 17.
Paper feed roller 22 and separation roller
The transfer force by 23 is up to the contact point of these two rollers,
The position is outside the wall surface 7a.

Next, the paper is fed to the paper feed roller 22 and the elastic piece 6 in contact with the paper feed roller 22.
And is conveyed by being pressed against the paper feed roller 22 by the elasticity of the elastic piece 6. At this time, the front end 6a of the elastic piece 6 is located inside the wall surface 7a of the intermediate tray 17, and the sheet is reliably fed into the intermediate tray 17 to the rear end. The above is the storing operation in the intermediate tray at the time of double-sided copy and composite copy. The sheet stored in the intermediate tray 17 has the copied side facing upward.

Next, a paper feeding operation from the intermediate tray 17 will be described.
First, the sheet feeding operation in the case of double-sided copying will be described with reference to FIGS. The paper in the intermediate tray 17 is pressed against the paper feed roller 22 by the bottom plate 33. At the same time, the motor rotates in the opposite direction to that during storage, and the paper feed roller 22 rotates counterclockwise. Further, the separation roller 23 is rotated in a direction in which the paper fed by the paper feed roller 22 is blocked by the sliding torque of the clutch spring, that is, counterclockwise in FIG. 16 (a). By the above operation, the sheet in the intermediate tray 17 is always separated by one sheet so that a plurality of sheets are not sent simultaneously by the separation roller 23 which is sent out with one end pressed against the sheet feeding roller 22. Will be sent out.

At this time, as shown in FIG. 16 (b), the tip 6a of the elastic piece 6 is
And does not hinder the advance of the paper.

[Problems to be solved by the invention]

First, in the conventional apparatus, even if the two-sided copy mode is continuously executed, the push plate 35 described in the above 2) is used.
And the moving time of the side plate 36 (moved and aligned for each sheet)
And 3) there is a problem that the time required for raising the bottom plate 33 takes time that is not directly related to the original copying operation.

Next, in the above-mentioned conventional apparatus, there is a case where a trouble of refeeding error due to jamming or locking of the bottom plate may occur.

FIG. 20 and FIG. 21 are explanatory views showing the problems of the conventional apparatus when the intermediate tray for storing paper is stored and when paper is re-fed.
When the paper P shown in the drawing is stored in the intermediate tray 17, the paper conveyance direction is reversed by the diameter of the paper feed roller. P
Tries to spread outward. For this reason, the leading end of the sheet P hits the separation roller 23 exposed from the guide member 29 and the sheet P
Slips.

In the case of continuous copying of a plurality of sheets, if the sheet P slips, the sheet interval becomes irregular, and in some cases, the sheets may be in a continuous state.

For this reason, there has been a problem that a jam occurs or a bad influence is exerted when a control for detecting a sheet length and a sheet interval is used.

Also, at the time of refeeding as shown in FIG. 21, if the leading end of the sheet P sent out by the sheet feeding roller 22 has a large floating amount, the sheet end does not enter the conveyance path leading to the copier main body, as shown in the figure. There was a problem that it ran into the guide piece 21 and caused a jam.

FIG. 22 and FIG. 23 are explanatory views showing a defect of the paper holding member according to the conventional example, and when the bottom plate 33 is going to rise,
A component force is generated in the paper holding member 2. In this case,
When the component force F ₁ as 22 Figure is small, the friction coefficient of the paper pressing member 2 and the sheet P can not be raised bottom plate 33 is large, a problem has been made that would be lock.

The technique proposed in Japanese Patent Application Laid-Open No. 63-154541 in order to prevent a stack defect in the above-described conventional apparatus corresponds to the central portion of the single-sided copied paper, that is, the paper feed roller 22 and the separation roller 23. Since the elastic piece 6 is provided, the central portion of the leading end of the one-sided copied paper at the time of stacking is 16th.
As shown in FIG. 18 and FIG. 18, the vehicle enters the intermediate tray 17 in a state of being lifted high. However, both side edges of the single-sided copied paper enter in a state of being lowered as shown in FIG. 17 and FIG. In addition, the copied paper may be curled. Depending on the direction of the curl, both sides of the paper with the back (back curl) are further lowered,
The sheets stacked on the intermediate tray 17 as shown in FIG.
Paper b enters as pushing the a _1, the paper a ₁ is pushed in as shown by the broken line causing Sutatsuku failure.

Such a stacking defect prevents the leading edge of the discharged paper from hitting the trailing edge of the stacked paper if the height from the bottom plate 33 position of the intermediate tray 17 to the paper discharging position is sufficient. Increasing the height increases the overall height of the copying machine, causing a problem in operability, and also makes it impossible to make use of the space saving property of the forward / reverse rotating paper feed roller system.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described state of duplex copying, and a first object of the present invention is to provide a duplex feeder capable of shortening the time in duplex copying mode.
A second object of the present invention is to provide a double-sided paper feeding apparatus capable of preventing a refeeding error due to a jam or a bottom plate from being locked and a trouble such as an error. Further, a third object of the present invention is to enable a stable stack without increasing the height of the apparatus, and to retreat the guide member at the time of re-feeding so that skew can be prevented and stable feeding can be performed. Also, since the retracting operation of the guide member is linked to the vertical movement of the bottom plate, there is no need to separately prepare a driving means for the guide member, and a double-sided paper feeder that can automatically perform timing control with a simple configuration is provided. Is to do.

[Means for solving the problem]

The first object is to provide an intermediate tray for storing single-sided copied paper, a paper feed roller rotatable in a direction of feeding the intermediate tray, and a direction of sending out the intermediate tray for duplex copying, and a paper feed roller. In the case of performing double-sided copying of a large number of sheets in a double-sided sheet feeding device having a separating roller that comes into contact with the sheet, the last sheet of the single-sided copied sheet sent to the intermediate tray is detected, and the sheet feeding roller and the separating roller are finally moved. This is achieved by the first means including a sensor for generating a detection signal for stopping the driving while holding the trailing edge of the paper.

The second object is a double-sided paper feeder having an intermediate tray for storing single-sided copied paper, and a paper feed roller rotatable in a direction to be fed into the intermediate tray and a direction to be sent out for duplex copying from the intermediate tray, A guide plate disposed near the paper feed roller for guiding the single-sided copied paper to the intermediate tray; and a guide plate having a center on the intermediate tray side with respect to a position perpendicular to the guide plate from the paper feed roller center. This is achieved by a second means provided with a separation roller provided in contact with a paper roller.

The second object is to form an angle between the perpendicular of the second means and a line connecting the paper feed roller and the center of the separation roller by two.
This can also be achieved by a third means of 4 to 4 degrees.

A second object of the present invention is to provide a double-sided paper feeder similar to the second means, wherein a liftable bottom plate disposed in the intermediate tray and a rotatable upper plate are provided above the intermediate tray. The fourth means includes a paper holding member having a pressing portion that rotates while pressing the rear end of the paper sent to the intermediate tray by raising the bottom plate.

The third object is to provide an intermediate tray for storing single-sided copied paper, a forward and reverse rotation in a direction for feeding the single-sided copied paper to the intermediate tray, and a direction for sending out double-sided copying from the intermediate tray. A paper feed roller, a separation roller pressed against the paper feed roller, and an auxiliary roller that rotates forward / reverse in conjunction with the paper feed roller in a target arrangement around the paper feed roller. The line connecting the axis of the roller and the separation roller is arranged at an angle, so that the paper is fed downward during the storage, and the paper feed roller is pressed against the upper part of the paper when re-feeding to separate the paper. In the double-sided copying apparatus, a guide member is provided so as to face the auxiliary rollers at both ends, and when the single-side copied paper is fed into the intermediate tray, the guide member removes the single-side copied paper. It is achieved by the fifth means to direct the distal end portion of the opposite ends upwards.

Similarly, the third object is achieved by a sixth means in which the guide member of the fifth means is constituted by a flexible member.

Similarly, the third object is to provide a guide member of the sixth means so as to be able to move forward and backward with respect to the conveyance path of the single-sided copied paper, and to press the forward and backward movement against the paper feed roller to generate a paper feed pressure. This is also achieved by a seventh means interlocked with the vertical movement of the bottom plate.

[Action]

According to the first means, the passage of the last sheet of a large number of sheets is detected by a sensor, and a sheet feed roller is used before the sheet is completely discharged onto the bottom plate in the intermediate tray by a detection signal from this sensor. Stops. Therefore, the trailing edge of the paper remains sandwiched between the paper feed roller and the separation roller, and the positioning operation by the push plate and the side plate and the operation of raising the bottom plate and abutting against the paper feed roller become unnecessary for the paper. Re-feeding is performed in a short time.

According to the second and third means, when sheets are stored in the intermediate tray by arranging the separation roller on the intermediate tray side from a perpendicular position passing through the center of the paper feed roller with respect to the guide plate facing the paper feed roller. This allows room for slipping paper. That is, when the position of the separation roller is shifted toward the intermediate tray, the position where the leading end of the sheet abuts on the separation roller is also shifted toward the intermediate tray. Then, the paper transport path becomes closer to a straight line from the curve along the diameter of the paper feed roller, the spread of the paper due to the repulsive force of the "hip" becomes smaller, and even if the paper abuts, it becomes difficult to slip. In addition, the inconvenience that the leading edge of the sheet abuts against the surface of the separation roller (high friction coefficient) is also eliminated.

Further, at the time of re-feeding, the leading end of the sheet is transported along the lower guide plate without the end of the sheet abutting on the upper re-feeding guide piece.

Further, according to the fourth means, since the pressing portion of the paper pressing member is rotatable, the bottom plate can be raised without rocking due to friction between the pressing portion and the paper when the bottom plate of the re-feeding is raised, This can prevent refeed errors.

According to the fifth means, when feeding the single-sided copied paper to the intermediate tray, the leading end of the single-sided copied paper discharged downward by the paper feed roller is moved upward along the guide member. The paper is discharged to the tray, and the leading edge of the single-sided copied paper does not hit the trailing edge of the stacked paper.

According to the sixth means, the guide member is a mylar sheet, and the leading end of the mylar sheet is pressed against the paper feed roller and the auxiliary roller during stacking to apply a conveying force to the paper, and the rear end of the paper is reliably placed in the middle. Can be sent into the tray.

According to the seventh means, the operation of the guide member is interlocked with the operation of the bottom plate, so that the guide member is automatically retracted from the transport path at the time of sheet refeeding without providing a separate drive means for the guide member. And the configuration can be simplified.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the same reference numerals are given to portions which are the same as or can be regarded as the same as those in the conventional example, and redundant description will be omitted.

FIG. 1 is a schematic diagram showing a main part of a first embodiment of a double-sided paper feeding apparatus according to the present invention, in which a paper P is passed above a paper feeding roller 22 (passage when the paper P is fed to an intermediate tray 17). A sensor 5 for detecting is provided. In the case where only one sheet of paper P is subjected to duplex copying, the sensor 5 detects the trailing end of the sheet P, and in the case where multiple sheets of duplex copying are performed, the trailing edge of the final sheet P is detected by the sensor 5.

The sensor 5 outputs a detection signal of the sheet P, and a control unit (not shown) issues a command to stop driving the sheet feeding roller 22 at a predetermined timing based on the detection signal. In this case, the predetermined timing refers to the rotation of the paper feed roller 22 such that the rear end of the paper P is sandwiched between the paper feed roller 22 and the separation roller 23, and is separated from the upper guide piece 21. Is the timing to stop. FIG. 1 shows this state. In this case, the pinched paper P is always pinched by the pair of rollers during the conveyance, so that new positioning by the side plate or the like is not necessary. Then, at the time of re-feeding, the sheet P is fed into the main body 1 from this state.

In this manner, according to the first embodiment, the positioning operation of the sheet P by the push plate 35 and the side plate 36 (see FIG. 13) and the pushing of the bottom plate 33 to the paper feed roller 22 are performed. Since the contact operation is unnecessary, the copying operation time in which the sheet is re-supplied in a short time is reduced.

2 and 3 are views for explaining a second embodiment of the double-sided paper feeder according to the present invention. FIG. 2 is an explanatory view showing a configuration of a main part, and FIG. 3 is a characteristic view showing operation. is there.

In FIG. 2, the center position of the separation roller 23 is a guide plate.
From the perpendicular line l ₁ from the paper feed roller 22 center for 32, it is provided on the intermediate tray 17 side.

This deviation example, in the range of linear l ₂ and the perpendicular lines angle of l ₁ alpha 2 to 4 degrees connecting the center line of the paper feed roller 22 and the separation roller 23.

In FIG. 2, L is a perpendicular line l ₁ when the leading end of the paper P is gripped by the nip between the paper feed roller 22 and the separation roller 23.
Is the distance from the guide plate 32 to the rear end of the sheet P, and H is the height (lift) from the guide plate 32 in that case. The smaller the height H is, the more smoothly the paper P is gripped by the nip portion between the paper feed roller 22 and the separation roller 23, thereby preventing the paper P from slipping.

In FIG. 3, α (degree) is plotted on the horizontal axis and H (mm) is plotted on the vertical axis. As described above, the effect becomes remarkable when α is set to 2 degrees or more.

FIG. 4 shows a third embodiment, in which the paper holding member 2 is improved.

That is, the paper pressing member 2 includes a guide portion 2a for guiding the leading end of the paper P and a pressing portion 2b for pressing the rear end of the paper P sent to the intermediate tray 17. Here, the pressing portion 2b is used. 2b is rotatable by, for example, a roller.

Accordingly, the bottom plate 33 can be raised without being locked by the rotation of the pressing portion 2b.

FIG. 5 shows a modified example thereof. The roller constituting the pressing portion 2b shown in FIG. 4 has a large diameter and is always in contact with the bottom plate 33. The pressing portion 2b is constituted by a roller. In this case, the bottom plate 33
The roller contacts the bottom plate 33 only when the component force for the initial rotation of the ascending is small, but this configuration can sufficiently prevent the bottom plate 33 from locking.

In this manner, according to the second embodiment, a margin can be provided for the slip of the paper when the paper is stored in the intermediate tray, and the paper can be fed without the paper edge hitting the guide piece at the time of re-feeding. Will be Further, according to the third embodiment, since the pressing portion 2b is rotatable, the bottom plate 33 does not lock due to friction between the pressing portion 2b and the sheet when the bottom plate 33 rises during refeeding.

Next, fourth to seventh embodiments of the duplex copying apparatus according to the present invention will be described with reference to the drawings.

6 and 7 show a fourth embodiment of the double-sided copying apparatus according to the present invention. FIGS. 6 (a) to 6 (d) are explanatory diagrams showing respective operating states, and FIG. FIG. 7 (b) is a perspective view showing a guide member and a support member.

FIG. 8 is an explanatory view showing a fifth embodiment of the duplex copying apparatus according to the present invention.

9 and 10 show a duplex copying apparatus 6 according to the present invention.
FIG. 9 is an explanatory diagram showing an operation state, and FIG.
The figure is a perspective view of a main part of a guide plate portion.

FIG. 11 is an explanatory view showing a seventh embodiment of the duplex copying apparatus according to the present invention.

As already described, FIG. 12 is an explanatory diagram showing an outline of the entire configuration of a copying machine to which the present invention is applied, and FIG. 13 is an explanatory diagram showing an enlarged main part of the copying machine.

In FIG. 12, reference numeral 10 denotes a paper feeding cassette, 11 denotes a paper feeding device for feeding out paper from the paper feeding cassette 10, 12 denotes a registration roller for feeding and aligning the paper, and 13 denotes a photosensitive drum.
14 is a transfer device, 15 is a fixing device, 16 is a paper discharge roller for feeding paper to a paper discharge tray (not shown), 17 is an intermediate tray for storing the copied paper, and 18 is a paper discharge direction. The first switching claw for switching to the tray or the intermediate tray 17 is driven by a solenoid (not shown). Reference numeral 19 denotes a guide plate, and reference numeral 20 denotes a transport roller. The transport path is configured by the guide plate 19 and the transport roller. Reference numeral 21 denotes a second switching claw, which is driven to two positions by a solenoid (not shown).

Reference numeral 22 denotes a paper feed roller. The paper feed roller 22 is capable of normal rotation and reverse rotation. Reference numeral 23 denotes a separation roller. The separation roller 23 has a separation roller shaft 24 attached to a rotation arm 25, and the rotation arm 25 is urged by a tension spring 26 to move the separation roller 23 to the sheet feeding roller 22. We are in pressure contact. Although not shown, the separation roller 23 is provided with a one-way clutch. When the sheet supply roller 22 rotates in a direction to feed the sheet to the intermediate tray 17 by the one-way clutch, the separation roller 23 is driven, When the paper roller 22 rotates in the re-feeding direction, the separation roller 23 does not rotate but stops and separates sheets one by one.

Auxiliary rollers 28 are fixed to the paper supply roller shaft 27 of the paper supply roller 22 symmetrically around the paper supply roller 22, and the diameter of these auxiliary rollers 28 is set smaller than the diameter of the paper supply roller 22. (FIG. 6). A guide member 29 is provided facing the paper feed roller 22. The guide member 29 is made of an elastic piece, for example, a Mylar sheet having a thickness of about 0.2 mm. The lower portion of the guide member 29 is fixed to the support member 30, and the upper end 29 a of the guide member 29 is in contact with the auxiliary roller 28. In contact. When the auxiliary roller 28 rotates clockwise, the upper end 29a of the guide member 29 follows and is located inside the wall surface 17a of the intermediate tray 17. The support member 30 is rotatable about a support shaft 31. When the paper feed roller 22, that is, the auxiliary roller 28 rotates counterclockwise, the upper end 29a of the guide member 29 follows the intermediate position. Tray 17
, The support member 30 is also rotated clockwise about the support shaft 31. Also, a support member
The lower end 30a of 30 is bent to form a wall surface 17a of the intermediate tray 17.
Extending into the intermediate tray 17 from the opening of the
The upper end 30b of the 30 is bent in the opposite direction to the lower end 30a, and the bent portion 30c is set to protrude upward from the opening 32a of the guide plate 32 at the time of stacking as shown in FIG. The leading end of the sheet conveyed by the bent portion 30c is guided, and the leading end is guided by the guide member 29 and the support member 30.
So that it does not get into the junction.

The turning operation of the support member 30 is also linked to the operation of the bottom plate 33 that presses the paper in the intermediate tray 17 against the paper feed roller 22. The bottom plate 33 is operated only by the push-up means 34 during paper feeding. That is, the lower end 30a of the support member 30 is disposed below the bottom plate 33. When the bottom plate 33 moves down to the lower position (at the time of stacking), the lower end 30a is also pushed down by the bottom plate 33 to lower the support member 30. Rotate counterclockwise and support member
Hold 30. On the other hand, if the bottom plate 33 rises during refeeding,
The holding is released, and the tip 29a of the guide member 29 follows the rotation of the auxiliary roller 28 to tilt the support member 30 as described above. Reference numeral 35 denotes a push plate for stopping the leading end of the paper stored in the intermediate tray 17, and is inclined from the middle to the paper entry side. The push plate 35 is set at a position corresponding to the sheet size before the sheets are stored. Reference numeral 36 denotes a side plate for regulating the width of the paper, which aligns the paper when stored, and prevents skew of the paper when re-feeding. Reference numeral 37 denotes a second registration roller which sends the sheet re-fed from the intermediate tray 17 to the registration roller 12 after aligning the sheets.

In addition, a guide member, for example, a mylar sheet, is disposed to face the paper feed roller 22 so that the central portion of the leading end of the paper is discharged upward.

Regarding the operation of the fourth embodiment configured as described above,
This will be described with reference to FIGS. 6 (a) to 6 (d).

First, FIG. 6 (a) is an explanatory view showing a state in which the sheet is stored in the intermediate tray 17, and the sheet after one-sided copying is sent to the intermediate tray 17 by the paper feed roller 22 and the auxiliary roller 28 through the transport path. In this state, the bottom plate 33 is in the lower position, the lower end 30a of the support member 30 is pushed down by the bottom plate 33, and the support member 30 is erected, and the bent portion 30c is in the opening 3 of the guide plate 32.
Projecting from 2a. The upper end 29a of the guide member 29 fixed to the support member 30 follows the clockwise rotation of the auxiliary roller 28 and is located inside the wall surface 17a, and the tangent to the auxiliary roller 28 rises to the left. I have. Then, the leading end of the sheet that has passed through the conveyance path around the auxiliary roller 28 is
The guide member 29 is guided against the bending member 30c of the support member 30, and is sent to the contact surface between the tip end 29a of the guide member 29 and the auxiliary roller 28.
The leading end 29a of the guide member 29 faces upward, and discharges the sheet to the intermediate tray 17 with the leading end thereof facing upward. Also,
Since the leading end 29a presses the paper against the auxiliary roller 28,
A conveyance force is generated on the contact surface, and the sheet can be more reliably fed into the intermediate tray 17.

Next, a refeed operation from the intermediate tray 17 will be described.

At the time of re-feeding, as shown in FIG.
28 rotates counterclockwise, the lifting means 34 is released, the bottom plate 33 rises, and the holding of the support member 30 is released, so that the support member 30 can be tilted. The tip 29a of the guide member 29 moves rightward following the rotation of the auxiliary roller 28 in the counterclockwise direction, and with this movement, the support member 30 tilts rightward.

Then, the bottom plate 33 further rises and presses the rear end upper surface of the stored paper against the paper feed roller 22, and the pressing force generates a conveying force by the counterclockwise rotation of the paper feed roller 22,
The paper is pulled in and re-fed. At this time, the paper feed roller
The separation roller 23, which is in pressure contact with the sheet 22, does not follow the counterclockwise rotation of the sheet supply roller 22 by the action of the one-way clutch, so that the separation roller 23 separates the sheets one by one. . As shown in FIG. 1C, when the bottom plate 33 is raised and the paper is pressed against the paper feed roller 22, the paper is not pressed against the auxiliary roller 28. That is, re-feeding is performed by the conveyance force of only the feed roller 22. Further, the lower end portion 30a of the support member 30 is in contact with the upper edge of the lower opening of the wall surface 17a and is held in a tilted state. In this inclined state, the upper end 29a of the guide member 29 is
8 and is set to a position retreated from the refeeding conveyance path.

Next, the operation of storing sheets in the intermediate tray 17 again will be described.

When the sheet re-feeding state shown in FIG.
The auxiliary roller 28 and the paper feed roller 22 rotate clockwise as shown in FIG. Further, the lifting means 34 is operated to lower the bottom plate 33, and the bottom plate 33 is moved to the lower end 30 of the support member 30.
Depress a to cause the support member 30 to be in an upright state (in the direction of the arrow). Then, the upper end member 29a of the guide member 29 fixed to the support member 30 abuts on the auxiliary roller 28, and the upper end portion 29a follows the rotation of the auxiliary roller 28 by the frictional force to form the upper surface 29a of the wall surface 17a of the intermediate tray 17. It is located inside and is in the state of FIG. 6 (a).

In the fourth embodiment configured as described above, a guide member 29 is provided to face the paper feed roller 22 and the auxiliary roller 28, and the leading end of the sheet at the time of storage is directed upward. The line connecting the pair of axes is inclined, and even if the leading edge of the ejected sheet is downward, the leading edge of the sheet does not face upward and hits the trailing edge of the sheet in the intermediate tray 17 and is stable. Stacking becomes possible, and the thickness of the intermediate tray 17 can be reduced accordingly, so that the height of the apparatus as a whole can be reduced.

Further, the guide member 29 facing the auxiliary roller 28 is configured to retreat from the conveyance path at the time of re-feeding by the rotation of the support member 30.
The paper is conveyed stably by the rotation of the separation roller 22 and the separation roller 23, but the separation roller 28 stops at the time of re-feeding and the paper is conveyed only by the rotation of the paper supply roller 22. Even in the feeding state, the leading end of the guide member 29 facing the auxiliary rollers 28 located at both ends of the sheet does not contact the sheet to be re-fed, and no force for causing skew occurs on the sheet. . Therefore, stable paper feeding is possible.

Further, by forming the guide member 29 by a mylar sheet, the sheet is supported by the auxiliary roller 28 at the tip 29a of the guide member 29.
To generate a conveying force, and the sheet can be reliably fed into the intermediate tray 17. Further, the support member 30 can be rotated following the forward / reverse rotation of the auxiliary roller 28.

In addition, since the rotation of the support member 30 is linked to the vertical movement of the bottom plate 33, there is no need to separately provide a solenoid and a control device for the rotation of the support member 30. It can be.

Further, since the bent portion 30c of the support member 30 is projected upward from the opening 32a of the guide plate 32 during stacking, the intermediate tray 1
It is possible to prevent the leading end of the paper conveyed to be stored in 7 from entering the joint surface between the guide member 29 and the support portion 30 and catching the paper.

Further, since the support member 30 is tilted and retreated from the conveyance path at the time of re-feeding, the bent portion 30c has an obstacle that the sheet hits the bent portion 30c at the time of re-feeding and the conveyance is not performed smoothly. Can be removed.

 Next, a fifth embodiment will be described with reference to FIG.

The fifth embodiment differs from the fourth embodiment in that the bent portion 30c and the upper end 30b of the support member 30 in the fourth embodiment are not provided, and the fifth embodiment is different from the fourth embodiment. The upper end of the member 30 extends straight below the opening 32a of the guide plate 32.

Next, a sixth embodiment will be described with reference to FIGS. 9 and 10. FIG.

The sixth embodiment is different from the fifth embodiment in that projections 32b projecting upward are formed on both side ends of an opening 32a of a guide plate 32, and the surface of the projection 32b is The leading edge of the paper conveyed at the time of storage contacts the guide member 29.
Is guided in the direction of the contact portion between the leading end 29a of the roller and the auxiliary roller. As a result, the leading end of the paper is
There is no risk of catching on the 30 joint surfaces.

 Next, a seventh embodiment will be described with reference to FIG.

In the seventh embodiment, the guide member 38 is made of an inelastic material and does not contact the auxiliary roller 23 during stacking (shown by a solid line). The guide member 38 is fixed to an arm 40 having one end rotatably supported on a support shaft 39.
It is interlocked with the vertical movement of the bottom plate 33 via a lever 42 rotatably supported by 41. Reference numeral 43 denotes an engagement portion provided on the lever 42, which is engaged with the lower surface of the arm 40.

The operation of the seventh embodiment will be described. During stacking (shown by a solid line), the bottom plate 33 is in the lower position and the lever 42
Are held at the positions of the arm 40 and the guide member 38 indicated by the solid line through. In this state, when the sheet is conveyed, the leading end of the sheet is guided along the upper surface of the guide member 38 and is discharged upward from between the guide member 38 and the auxiliary roller 23 into the intermediate tray 17.

Further, at the time of re-feeding, the bottom plate 33 rises in the same manner as in the above-described embodiment, and the guide member 38 and the arm
Due to its own weight or spring force, 40 rotates clockwise about the support shaft 41 and retreats below the guide plate 32 (the position indicated by the dashed line).

In the seventh embodiment, a roller may be provided at the left end of the guide member 38, and this roller may be brought into contact with the auxiliary roller 28.

In this manner, according to the fourth to seventh embodiments, when the paper is fed into the intermediate tray without increasing the height of the apparatus, the rear end of the stacked paper is Will not be hit.

〔The invention's effect〕

As described above, according to the first aspect of the present invention,
Since the trailing end of the last sheet of a large number of sheets is sandwiched between the feed roller and the separation roller, the positioning operation by the aligning means such as the push plate and the side plate is unnecessary, and the sheets are stacked on the intermediate tray. Therefore, the time required to shift from paper feeding to re-feeding can be shortened, so that the copying operation time can be shortened.

Similarly, according to the second and third aspects of the present invention, the separation roller is arranged on the intermediate tray side from the perpendicular position passing through the center of the paper feed roller with respect to the guide plate facing the paper feed roller, so that the paper is fed to the intermediate tray. This allows room for slippage of paper when storing paper. Then, at the time of re-feeding, a stable transporting property can be obtained without the paper edge abutting on the upper re-feeding guide piece.

According to the fourth aspect of the present invention, since the pressing portion of the paper pressing device is rotatable, the bottom plate is raised without rocking due to friction between the pressing portion and the sheet when the bottom plate is raised in re-feeding. This makes it possible to prevent refeed errors.

Similarly, according to the fifth, sixth, and seventh aspects of the present invention, a stable stack can be achieved without increasing the height of the apparatus, and the guide member is retracted during re-feeding. The skew can be prevented and stable paper feeding can be performed.The evacuation operation of the guide member is linked to the up and down operation of the bottom plate, so there is no need to prepare a separate drive means for the guide member. This operation can be performed automatically, and the above operation can be achieved with a simple configuration by using a mylar sheet as the guide member.

[Brief description of the drawings]

FIG. 1 is a main part configuration diagram of a first embodiment of a double-sided paper feeding device according to the present invention, FIG. 2 is a main portion configuration diagram of a second embodiment of a double-sided paper feeding device according to the present invention, and FIG. FIG. 4 shows the characteristics of FIG.
FIG. 5 is a view showing a main part of a modified example of the double-sided paper feeding apparatus, and FIGS. 6 and 7 show a fourth embodiment of a double-sided copying apparatus according to the present invention. FIG. 6 is an explanatory view showing each operation state, FIG. 7 (a) is a perspective view of a main part of a guide plate,
FIG. 7 (b) is a perspective view of a guide member and a support member incorporated in the guide plate, FIG. 8 is an explanatory view showing a fifth embodiment of the double-sided copying apparatus according to the present invention, FIG. 9 and FIG. Shows a sixth embodiment of the duplex copying apparatus according to the present invention, FIG. 9 is an explanatory view showing an operation state, FIG. 10 is a perspective view of a main part of a guide plate portion, and FIG. FIG. 12 is an explanatory view showing a seventh embodiment of a copying apparatus, FIG. 12 is a configuration diagram of a copying machine to which the present invention is applied, FIG. 13 is a configuration diagram of the double-sided paper feeding device, and FIG. FIG. 15 is a configuration diagram centering on a conventional paper pressing member, FIGS. 16 to 17 are explanatory views of the proposed device, and FIG. 16 is a paper feed roller. FIG. 17 is a vertical cross-sectional view showing a schematic configuration of an auxiliary roller portion, and FIG. 18 is a longitudinal sectional view showing a schematic configuration of an auxiliary roller portion. 19 is an explanatory view showing the state of the leading edge of the sheet to be inserted, FIG. 19 is an explanatory view showing the state of feeding the sheet to the intermediate tray, FIG. 20 and FIG. FIG. 22 and FIG. 23 are explanatory diagrams showing the problems of the conventional device, and FIG. 22 and FIG. 23 are explanatory diagrams showing the problems of the paper holding member according to the conventional example. 5: Sensor, 17: Intermediate tray, 22: Feed roller,
23: separation roller, 29: guide member, 32: guide plate, 33: bottom plate, 35: push plate, 36: side plate.

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B65H 83/00-85/00

Claims (7)

(57) [Claims] An intermediate tray for storing single-sided copied paper, a paper feed roller rotatable in a direction of feeding into the intermediate tray and a direction of feeding out the intermediate tray for duplex copying, and comes into contact with the paper feed roller. When performing double-sided copying of a large number of sheets in a double-sided sheet feeding device having a separation roller, the last sheet of the single-sided copied sheet sent to the intermediate tray is detected, and the sheet feeding roller and the separation roller detect the last sheet. A double-sided paper feeder comprising a sensor for generating a detection signal for stopping driving while holding a rear end. 2. A double-sided paper feeder, comprising: an intermediate tray for storing single-sided copied paper; and a paper feed roller rotatable in a direction of feeding the intermediate tray and a direction of sending the two-sided copy from the intermediate tray. A guide plate disposed near a paper roller for guiding the single-sided copied paper to the intermediate tray; and a center located on the intermediate tray side from a position perpendicular to the center of the paper feed roller with respect to the guide plate and the paper feed roller. And a separation roller provided in contact with the sheet feeder. 3. The double-sided sheet feeding device according to claim 2, wherein an angle between the perpendicular and a line connecting the sheet feeding roller and the center of the separation roller is 2 to 4 degrees. 4. A double-sided paper feeder, comprising: an intermediate tray for storing single-sided copied paper; and a paper feed roller rotatable in a direction of feeding the intermediate tray and a direction of sending the two-sided copy from the intermediate tray. Paper having an ascending bottom plate provided in the tray, and a pressing portion rotatably mounted above the intermediate tray and rotating while pressing the rear end of the sheet fed into the intermediate tray by the raising of the bottom plate. A double-sided paper feeding device, comprising: a holding member. 5. An intermediate tray for storing single-sided copied paper, a forward / reverse rotation in a direction for feeding the single-sided copied paper to the intermediate tray, and a direction for sending out double-sided copying from the intermediate tray, and feeding the sheet on a center basis. A paper feed roller, a separation roller pressed against the paper feed roller, and an auxiliary roller that rotates forward and reverse in conjunction with the paper feed roller in a target arrangement around the paper feed roller; A line connecting the axis of the separation roller is arranged at an angle, and the paper is fed downward during storage, and the paper feed roller is pressed against the top of the paper when paper is re-fed to separate the paper. In the copying apparatus, a guide member is provided to face the auxiliary rollers at both ends, and when the single-sided copied paper is fed into the intermediate tray, the width of the single-sided copied paper is adjusted by the guide member. Duplex paper feed apparatus, characterized in that the front end portions at both ends and to direct above the. 6. A double-sided paper feeder according to claim 5, wherein said guide member is formed of a flexible member. 7. The guide member is provided so as to be capable of moving forward and backward with respect to the conveyance path of the single-sided copied paper, and the forward and backward movement is performed by a vertical movement of a bottom plate which presses against the paper feed roller to generate a paper feed pressure. 7. The double-sided paper feeder according to claim 6, wherein the paper feeder is linked.