JP2907650B2 - Reverse paper feed unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper processing apparatus (hereinafter referred to as a printer) such as a copying machine or a printing apparatus, in which a sheet is turned over to be copied or printed again (hereinafter referred to as printing). And a reversing sheet feeding unit for feeding sheets to the sheet feeding unit.

[0002]

2. Description of the Related Art Conventionally, for example, as shown in FIG.
2. Description of the Related Art A printer that reverses a sheet printed in a printing unit and prints on both sides of the sheet is known. Hereinafter, a printer having a sheet reversing function will be described with reference to FIG.

A paper feed cassette 2 is provided at a lower portion in the printer main body 1.
For example, A3 size paper 3 is stacked and accommodated. The stacked and accommodated sheets are fed out one by one by a feed roller 4 and guided to a sheet guide 7 by a pair of conveying rollers 5a. Then, the sheet guided to the sheet guide 7 is conveyed to a printing unit 8 provided at an upper part in the printer main body 1 via a pair of conveying rollers 5b and 5c.

The sheet printed by the printing unit 8 is guided to a sheet guide 11a via a pair of conveying rollers 9. An on-off valve (path switching mechanism) 10 is disposed downstream of the paper guide 11a. When one-side printing is performed on the paper, the on-off valve 10 is rotated clockwise from the state shown in FIG. The sheet is discharged to the discharge tray 13. On the other hand, when performing double-sided printing on a sheet, the on-off valve 10 is in a state as shown in the figure, and guides the printed sheet to the guide 11b of the reversing unit.

A sheet reversing unit 12 is provided at a central portion in the printer main body 1. A sheet guided to a guide 11b for the reversing unit is fed to a pair of reversing sheet feeding rollers 12a.
The sheet is placed on the placing plate 12b in the sheet reversing unit 12 via the line a. In this case, the rear end of the printed sheet is in a state of being bitten by the pair of reverse sheet feed rollers 12a. Thereafter, by rotating the pair of reverse feeding rollers 12a in the opposite direction, the printed sheet is guided to a reverse feeding path 12e provided above the sheet reversing unit 12, and the conveying rollers 12c, 12d, and 12f and the guides are guided. The sheet 13 is again guided to the sheet guide 7.

The paper guided again to the paper guide 7 is in a state reversed from the state where it is first guided from the paper feed cassette 2 to the paper guide 7, and thereafter, the surface already printed in the printing section 8 is printed. The printing is performed on the surface on the opposite side from. Then, the paper on which the double-sided printing has been performed is carried by the conveying roller pair 9 and the opening / closing valve 10 rotated clockwise from the state shown in FIG.
Is discharged to the discharge tray 13 via the As described above, one-sided printing or two-sided printing is performed on the paper.

[0007]

As described above, the conventional printer is configured to perform one-sided printing or two-sided printing on paper. That is, a unit for reversing the sheet so that double-sided printing can be performed is incorporated in the printer.

However, when printing is actually performed on paper, the double-sided printing mode may not always be required depending on the application. This means that unnecessary units are incorporated in the printer for single-sided printing in advance, and as a result, the cost of the printer body increases. In addition, it is necessary to provide a mechanism for driving the unnecessary unit in the printer for single-sided printing in advance, which increases the size and weight of the printer, as well as the structure,
Process management and the like become complicated. On the other hand, in a printer for single-sided printing, when it is necessary to print on both sides of the paper depending on the application, this cannot be performed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a reversing device capable of performing double-sided printing or the like as necessary even for a printer having a simple structure for single-sided printing and copying. An object is to provide a paper feeding unit.

[0010]

In order to solve the above-mentioned problems, a reversing sheet feeding unit according to the present invention is provided in a printer main body.
Separately feeds stacked paper into the paper insertion slot opened on the side
Equipped with a detachable automatic paper feeder, fed from the insertion slot
Which is detachably mounted printing and the printer body outside the upper surface having a printing unit that performs copying on one side of the sheet, reverse feed unit again by inverting the printed or copied paper on one side for feeding the printing section A guide means for guiding a sheet printed or copied on one side to a reversing sheet supply unit, a switchback mechanism for reversing a feed direction of the sheet guided through the guide means back and forth, and a switchback mechanism. A sheet conveying unit that conveys the sheet toward the printing unit via an outlet near the sheet insertion port; and the same driving unit that drives the guide unit, the switchback mechanism, and the sheet conveying unit. Features.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the accompanying drawings. FIG. 1 shows a reversing sheet feeding unit 5 according to the present invention.
FIG. 2 is a diagram showing a state in which 0 is attached to the upper surface of a printer body 30 for single-sided printing. This reversing sheet feeding unit 50
It is detachable from the frame 40 of the printer main body 30 by attachment members 51a and 51b such as screws.

Referring to FIG. 1, an automatic paper feeder 20 detachable from a printer main body 30 is provided with a hopper 23 on which sheets 22 of various sizes are placed. , The sheet is separated into one sheet by the separation roller 24 and the separation member 25, and is fed from the guide section 26 to the sheet insertion port 42 of the printer. Further, the automatic paper feeder 20 is provided with a manual feed guide 27 for manually feeding paper into the insertion slot 42 one by one, and an engagement portion 28 is provided at a front portion. The main body 30 is detachable from the automatic paper feeder attaching / locking portion 43.

In the printer main body 30, the insertion port 42 is provided.
A registration roller pair 32 for transporting the paper inserted from the printer toward the printing unit 34 is provided. A sensor 33a for detecting the leading end of the sheet inserted from the insertion slot 42 is provided immediately before the registration roller pair 32. On the downstream side of the printing unit 34 in the printer main body 30, there are provided transport roller pairs 35 and 36 for transporting the printed paper, and between these roller pairs 35 and 36,
A sensor 33b for detecting passage of a sheet is provided.

The sheet conveyed by the pair of conveying rollers 36 is guided to either the discharge port 39b or the discharge port 39a to the reversing sheet supply unit 50 by the on-off valve 52 described later at the sheet path switching position 52a. It has become.
In the state shown in FIG.
The sheet is positioned so as to be guided to the sheet tray b, and the sheet is discharged from a discharge port 39b through a pair of discharge rollers 37 and 38 onto a discharge tray (not shown).

In the drawings, a drive source for driving each roller pair, a printing unit, etc., a mechanism for turning on / off the transmission of a driving force, a control means for controlling these drives, and the like are omitted. .

Next, the structure of the reversing sheet feeding unit 50 is shown in FIG.
This will be described with reference to FIG. Reverse paper feed unit 50
Has a base plate 60 and a top cover 70. The top cover 70 is
0 allows the base plate 60 to open and close freely. The base plate 60 is formed so as to match the upper surface shape of the printer main body. The base plate 60 is provided with mounting members 51a and 51b, whereby the reversing sheet feeding unit 50 is detachable from the printer main body. The reversing sheet feeding unit 50 includes:
An on-off valve 52 is provided corresponding to the above-described paper path switching position 52a, and the on-off valve 52 is rotatably supported on a frame (not shown) of the reversing sheet feeding unit 50 by a pin 52b. . That is, by rotating the open / close valve, it is possible to switch the transport path of the printed sheet.

In the reversing sheet supply unit 50, an on-off valve 52 is provided.
And a pair of switchback rollers 54a, 54b and 56 for nipping and conveying the sheet guided into the unit 50 through the
a, 56b are provided. Of these roller pairs,
The upper rollers 54a and 56a are on the driving side. A switchback window 74 is formed in the base plate 60 near the pair of switchback rollers 56a and 56b, and the sheet guided into the reversing sheet supply unit 50 has its rear end at the switchback roller pair 56a, 56b.
The sheet is pushed out of the reversing sheet feeding unit while being sandwiched by the sheet 56b. Switchback roller pair 54a, 54b and 56
A sensor 33c for detecting the end of the sheet being conveyed is disposed between the sensors 33a and 56b.

The frame of the reversing sheet feeding unit 50 is provided with a pair of conveying rollers 58a, 58b and 59a, 59b, and conveys the sheet conveyed from the pair of switchback rollers toward an outlet 76. Then, the sheet conveyed toward the exit is guided by the guide 77, and the leading end thereof is again pressed against the meshing portion of the registration roller pair 32. At this time, the state in which the sheet is conveyed from the automatic sheet feeding device 20 is reversed, and the sheet can be printed on a surface on which no printing is performed.

The base plate 60 and the top cover 70 are provided with a base guide rib 62 and a top cover guide rib 72, respectively, to stably guide sheets of various widths. The switchback roller pair and the transport roller pair described above are driven by a drive motor provided in the reverse sheet feeding unit 50. Next, the drive system of the reversing sheet feeding unit 50 will be specifically described with reference to FIGS.

The frame 101a of the reversing sheet feeding unit 50
Is provided with a drive motor 102, and a motor gear 103 is attached to a drive shaft 102a of the drive motor. This motor gear 103 has a frame 101
a is engaged with the reduction gear 104 attached thereto. The torque of the reduction gear 104 is transmitted to the gear 105 and the gear 111 attached to the frame 101b.

The gear 105 is mounted on the frame 101b and meshes with a gear 106 having a cam 108. The gear 106 has a torque limiter 107, which restricts rotation of the cam 108 in the counterclockwise direction. On the other hand, the clockwise rotation of the cam 108 is limited by the stopper 110. An on-off valve arm 52c is attached to the pin 52b pivotally supporting the on-off valve 52, and the cam 108 is engaged with the upper surface of the on-off valve arm 52c. A tension spring 109 is fixed to the tip of the on-off valve arm 52c.
2 is always urged counterclockwise about the pin 52b. Accordingly, when the gear 106 rotates in the direction shown by the arrow from the state shown in FIG.
Is rotated in the direction of the arrow by the urging force of (1), and the state shown in FIG. This state is defined as the initial position of the on-off valve 52.

An idler gear 112 meshes with the gear 111, and the idler gear 112
The gear 113a attached to the gear 01b is engaged.
The rotational force of the gear 113a is transmitted to the frame 101b and the frame
1c. The gear 114 has a gear 11 attached to a rotating shaft 56p having the switchback roller 56a shown in FIG.
5 are engaged. An idler gear 115 attached to the frame 101c meshes with the gear 115. The idler gear 115 has a rotating shaft 54p having the switchback roller 54a shown in FIG.
Is engaged with the gear 117. As a result, the rotation shafts 54p and 56p are rotated in the same direction.

Next, the operation of the drive system of the reversing sheet feeding unit 50 will be described with reference to FIGS. When the reduction gear 104 is rotated clockwise by the drive motor, the gear 106 rotates in the direction shown by the arrow, whereby the on-off valve 52 is rotated counterclockwise as shown by the arrow by the urging force of the tension spring 109. Be moved. That is, the on-off valve 52 selects the discharge port 39b as shown in FIG. 1 (initial position). The rotation of the cam 108 is stopped at an appropriate position by the stopper 110. At this time, the switchback rollers 54a and 56a shown in FIG. 1 are rotated counterclockwise via the gear train.

On the other hand, when the reduction gear 104 is rotated in the counterclockwise direction by the drive motor, the gear 106 rotates in the direction opposite to the direction shown by the arrow.
The cam 108 rotates clockwise against the urging force of the tension spring 109. That is, the on-off valve 52 is rotated clockwise from the initial position shown in FIG. 1, and selects the discharge port 39a. The rotation of the cam 108 is stopped at an appropriate position by the torque limiter 107. At this time, the switchback rollers 54a and 56a shown in FIG. 1 are rotated clockwise through the gear train. The drive motor 102 of the above-described reversing sheet feeding unit 50 includes sensors 33b, 3
It is driven based on the detection signal detected by 3c.

FIG. 5 is a plan view showing a mechanism for transmitting a driving force in the reverse sheet feeding unit 50. A gear 11 is provided on the rotation shaft 54p of the switchback roller 54a.
7, a toothed pulley 54r is attached. Further, toothed pulleys 58r, 59r are also provided on the rotating shafts 58p, 59p of the transport rollers 58a, 59a.
Is attached. A toothed belt 120 is wound around these toothed pulleys 54r, 58r, 59r, and the above-described rotating shafts 58p, 59p are
All are rotated in the same direction together with the rotation shaft 54p. In addition,
In the figure, reference numerals 122, 124 and 126 are attached to the frame 101c, respectively, and
Shows a tension pulley for applying tension. In the configuration described above, each operation will be described for the case of performing single-sided printing and the case of performing double-sided printing.

(A) The case of the single-sided printing mode will be described with reference to FIG. (1) The leading end of the sheet separated from the automatic sheet feeding device 20 by the separation roller 24 comes into contact with the meshing portion of the pair of registration rollers 32 through the insertion opening 42. The registration roller pair 32 is driven a fixed time after the sensor 33a detects the passage of the sheet. Therefore, the sheet is sent out by the separation roller 24 and the leading edge thereof is in contact with the meshing portion of the registration roller pair 32, so that the sheet is bent and the skew is removed.

(2) After the skew is removed, the sheet is conveyed toward the printing unit 34 by driving the registration roller pair 32. Further, the driving of the separation roller 24 is stopped at the same time as the driving of the registration roller pair 32, and the separation roller 24 rotates together with the sheet conveyance operation.

(3) The sheet on which printing has been performed by the printing unit 34 is conveyed toward a pair of conveying rollers 35 and 36.
In the single-sided printing mode, the open / close valve 52 is always in the initial position as shown in the figure, and the sheet is guided toward the pair of discharge rollers 37 and 38 at the sheet path switching position 52a.
Then, a discharge port 39b is provided through a pair of discharge rollers 37 and 38.
Is discharged onto a tray (not shown). Sensor 3
The driving of the printer is stopped a fixed time after the detection of the trailing edge of the sheet (time required for the sheet to be discharged to the tray), thereby completing one process of single-sided printing.

(B) The case of the double-sided printing mode will be described with reference to FIGS. (1) The steps from when one sheet of paper is separated from the automatic paper feeder 20 until printing is performed by the printing unit 34 are the same as those in (1) and (2) of (A).

(2) In the case of the duplex printing mode, the sensor 33
When b detects the passage of the sheet, the drive motor 102 is rotated forward based on this signal. The forward rotation of the drive motor 102 causes the reduction gear 104 to rotate counterclockwise.
As a result, the gear 106 rotates counterclockwise, and the on-off valve 52 is rotated clockwise from the initial position, so that the outlet 39 a
To release.

When the reduction gear 104 rotates counterclockwise, the switchback roller 54 shown in FIG.
a and 56a are rotated clockwise through the gear train. As a result, the sheet guided to the reversing sheet supply unit 50 via the on-off valve 52 is
a and 56a, and are pushed out from the switchback window 74 as shown in FIG. After the printed sheet is guided into the reversing sheet feeding unit 50 and the trailing edge of the sheet is detected by the sensor 33b, after a predetermined time (time until the sheet completely moves into the reversing sheet feeding unit), The drive system of the printer is stopped.

(3) The rear end of the printed sheet is the sensor 3
3c, the drive motor reversely rotates, thereby causing the switchback rollers 54a, 56a
Is rotated counterclockwise through the gear train. That is, the paper is sent out toward the transport path defined by the base guide ribs 62 and the top cover guide ribs 72, with the rear end side leading.

When the drive motor rotates in the reverse direction as detected by the sensor 33c, the reduction gear 104 rotates clockwise.
Accordingly, the gear 106 rotates clockwise, and the on-off valve 5
2 is rotated from the state shown in FIG. 3 in the direction shown by the arrow and returns to the initial position. The sheet sent out toward the transport path is moved in the transport path by the switchback roller pair and the transport roller pair driven together with the switchback roller. Then, the leading end of the sheet conveyed to the outlet 76 is again applied to the meshing portion of the registration roller pair 32 via the guide 77 and the manual feed port 42a.

(4) Thereafter, the paper is subjected to a skew removal and printing process in accordance with the same procedure as in the single-sided printing mode described in (A), and is discharged onto a tray (not shown) through the discharge port 39b. You. Thus, one step of the double-sided printing mode is completed.

In the drawings, control means for controlling the driving of the reversing sheet feeding unit 50 and the printer 30 based on the detection signals from the sensors are omitted.

In the case of the double-sided printing mode, when a paper jam or the like occurs in the reversing paper feed unit 50, the paper can be easily removed by opening the top cover 70 and releasing the paper passing path (FIG. 2). In addition, since the switchback mechanism for switching the sheet feeding direction and the switchback window 74 are provided to shorten the sheet reversing path, the size of the reversing sheet supply unit 50 can be reduced.

The mounting of the reversing sheet feeding unit 50 on the printer body 30 does not require connection of a driving force transmitting mechanism other than connection of a connector for transmitting a sequence from the printer body, so that mounting is easy. .

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments and can be variously modified. For example, the skew removing means, the attachment position of the reversing sheet feeding unit 50 to the printer main body, the attachment / detachment mechanism, and the like can be appropriately changed.

[0039]

As described above, the reversing sheet feeding unit according to the present invention comprises a switchback mechanism for reversing a sheet from a printer for one-sided printing, a driving means for driving the switchback mechanism, and a driving means for the switchback mechanism. And a driving force transmission mechanism for transmitting the driving force from the motor. For this reason, it is not necessary to provide a special device, mechanism, and the like for double-sided printing on the printer main body side only by the control sequence, so that the printer main body can be reduced in size and weight, and the cost can be reduced.

Further, the control means for the double-sided printing mode is small,
If the printer is provided in a lightweight printer for single-sided printing, double-sided printing can be performed by the reversing sheet feeding unit of the present invention.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a state in which a reversing sheet feeding unit of the present invention is mounted on an upper surface portion of a printer main body, and illustrates a single-sided printing mode.

FIG. 2 is a diagram illustrating a state in which a top cover of the reverse sheet feeding unit is opened.

FIG. 3 is a view showing a driving force transmission mechanism of the reverse sheet feeding unit.

FIG. 4 is a diagram showing a mechanism for transmitting a driving force from a driving motor of the reverse sheet feeding unit.

FIG. 5 is a plan view showing the inside of the reverse sheet feeding unit.

FIG. 6 is a diagram illustrating a state in which the reversing sheet feeding unit is attached to an upper surface portion of a printer main body and illustrating a duplex printing mode.

FIG. 7 is a side view showing a printer provided with a conventional sheet reversing mechanism.

[Explanation of symbols]

Reference Signs List 20: automatic paper feeder, 30: printer body, 34: printing unit, 50: reversing paper feed unit, 52: open / close valve, 54a,
56a: switchback roller, 74: switchback window, 102: drive motor.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-3-13463 (JP, A) JP-A-4-28677 (JP, A) JP-A-61-226049 (JP, A) JP-A-2- 95666 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) B65H 29/58 B65H 85/00 B65H 29/60

Claims (2)

(57) [Claims] 1. A paper insertion opening at a side portion of a printer main body.
Detachable automatic paper feeder that separates and feeds laminated paper into the mouth
The provided, in the printer body outside the upper surface having a printing unit that performs printing and copying on one side of the sheet fed from the insertion port
A reversing sheet feeding unit that is detachably mounted, inverts a sheet printed or copied on one side, and feeds the sheet again to the printing unit, and guides the sheet printed or copied on one side to the reversing sheet feeding unit. Guide means, a switchback mechanism for reversing the feed direction of the paper guided through the guide means back and forth, and feeding the switched back paper out near the paper insertion slot.
A reversing sheet feeding unit, comprising: sheet conveying means for conveying the paper toward the printing unit via an opening; and the same driving means for driving the guide means, the switchback mechanism, and the sheet conveying means. 2. The sheet conveying means includes a guide path on which the sheet is conveyed, and a conveying roller for conveying the sheet along the guide path, and the conveying roller is connected to the sheet via the switchback mechanism. The reversing sheet feeding unit according to claim 1, wherein the sheet feeding unit is driven by a driving unit.