JP2826051B2 - Printing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for show-through prevention printing and simple divided printing in a printing press.

[0002]

2. Description of the Related Art In a general printing apparatus, ink transferred to printing paper at the time of printing penetrates into the printing paper and does not stain when rubbed with a finger or the like. By the time this set is complete,
It took some time. If the next printing paper is loaded before the setting is completed, a problem of so-called show-through occurs, which transfers to the back side of the next printing paper on which the ink of the image portion of the previous printing paper is loaded. Was. This show-through is not a serious problem in normal printing in which printing is performed only on one side of the printing paper, but is a serious problem in double-sided printing or postcard printing.

In order to prevent such show-through, the printing speed may be reduced, the drum may be idled several times to increase the paper feed interval, or a collating device having a plurality of sort bins may be connected. Measures have been taken to discharge printed sheets one by one into each bin to increase the time until the next printed sheet overlaps.

In order to sort sheets, a collating device or a sorting device (see Japanese Patent Application Laid-Open No. 4-24657) is connected to a printing device to perform sorting.

[0005]

However, in the above-described countermeasure for preventing show-through, there is a problem that the efficiency of the printing operation is reduced when the printing speed is reduced or the drum is rotated to widen the paper feeding interval. In addition, in the countermeasure for connecting the collating apparatus to increase the time for discharging the paper, there is a problem that the cost is increased by connecting the collating apparatus.

[0006] Also, when paper is sorted, there is a problem that the cost is increased by connecting a collating device or a sorting device.

The present invention provides a printing apparatus which solves the above problems, prevents the show-through of printing paper without lowering the efficiency of the printing operation, and does not increase the cost. With the goal.

[0008]

According to the first aspect of the present invention,
A rotatable drum, a press roller movably provided between a first position that is an initial position away from the outer peripheral surface of the drum, and a second position that is in contact with the outer peripheral surface,
A sheet feeding device for feeding a printing sheet; and a moving unit for reciprocating the press roller between the first position and the second position. In the printing apparatus provided with a slip sheet mode for inserting a sheet, when the printing is performed by selecting the slip sheet mode, the moving means is alternately arranged on the printing sheet fed from the sheet feeding apparatus. Is provided with control means for operating.

According to a second aspect of the present invention, in the printing apparatus according to the first aspect, the paper feeder further includes a plurality of paper feed trays, and selects the interleaving mode and the respective paper feeds. When printing is performed by designating the printing paper tray and the interleaf paper tray respectively from the trays, the printing paper tray and the interleaf paper tray are alternately switched to change the printing paper to one. The sheet is fed one by one, and the moving unit is operated for the printing paper fed from the printing paper feeding tray, and the interleaving paper is fed from the interleaving paper feeding tray. For printing paper, a control means for stopping the operation of the moving means is provided.

According to a third aspect of the present invention, there is provided a drum which is rotatable, and wherein the first position is an initial position apart from the outer peripheral surface of the drum.
And a press roller movably provided between a second position in contact with the outer peripheral surface, a paper feeding device for feeding print paper, and the press roller, the first position and the first position. Moving means for reciprocating between a second position and a predetermined number of printed sheets per original, and inserting a slip sheet between groups of the predetermined number of printed sheets; In a printing apparatus having a grouping mode, when the grouping mode is selected and printing is performed by designating the number of groups and the number of prints per group, the movement is performed until the printing of the first group is completed. After the printing of the first group is completed, when the paper feeding device feeds one sheet of the printing paper as the slip sheet, the operation of the moving means is stopped, and then, During printing of the loop, characterized by comprising a control means for actuating the moving means again.

According to a fourth aspect of the present invention, in the printing apparatus according to the third aspect, the paper feeder has a plurality of paper feed trays, and selects the grouping mode and supplies each of the paper feed trays. From the trays, specify the paper feed tray for printing and the paper feed tray for slip sheets, and
When printing is performed by designating the number of prints of each group, for printing of the first group, paper is fed from the printing paper feed tray and the moving means is operated,
After the printing of the first group is completed, one sheet of the printing paper as a slip sheet is fed from the slip sheet feeding tray and the operation of the moving unit is stopped. Thereafter, when printing the next group, It is characterized by comprising control means for operating the moving means again.

According to a fifth aspect of the present invention, in the printing apparatus of the third aspect, the paper feeder further includes a plurality of paper feed trays, and each of the paper feed trays is moved in a direction perpendicular to the paper feed direction. Paper feed tray moving means for selecting the grouping mode, designating a paper feed tray for printing and a paper feed tray for interleaving from each paper feed tray, and When printing is performed by designating the number of prints of each group, for the printing of the first group, paper is fed from the printing paper feed tray and the moving unit is operated, and after the printing of the first group is completed, Feeds one sheet of printing paper as interleaving paper from the interleaving paper feeding tray which is moved by the paper feeding tray moving means and the feeding position of which is changed from the printing paper feeding tray. Stops the operation of said moving means together with, then, at the time of the next group printing, characterized by comprising a control means for actuating the moving means again.

According to a sixth aspect of the present invention, there is provided a drum which is rotatable, and wherein the first position is an initial position apart from the outer peripheral surface of the drum.
, A press roller movably provided between a second position in contact with the outer peripheral surface, a plurality of paper feed trays, a paper feed device for feeding paper, and the press roller Moving means for reciprocating between the first position and the second position, and a sorting mode for sequentially feeding a predetermined number of sheets of paper from each of the paper feed trays. In the printing apparatus, the sorting mode is selected, and the sheet feeding order from each of the sheet feeding trays, the number of sheets fed, and the number of sheets to be sorted are respectively specified, and the sheets fed from each of the sheet feeding trays are sorted. At the time, the paper is fed from each of the paper feed trays according to a specified paper feed order, the number of paper feeds, and the number of sheets, and the paper fed from each of the paper feed trays is Control means for stopping the operation of the moving means Characterized by comprising.

[0014]

According to the first aspect of the present invention, when printing is performed by selecting the slip sheet mode, the control means controls the moving means for every other sheet of printing paper fed from the paper feeding device. Since the printing paper is activated and the printing paper is brought into contact with the outer peripheral surface of the drum every other sheet by the press roller, unprinted paper is sandwiched between the printed papers.

According to the second aspect of the present invention, when the interleaving mode is selected and printing is performed by designating a printing paper tray and an interleaving paper tray from a plurality of paper trays, respectively. The control means alternately switches between the printing paper tray and the interleaving paper tray to feed the printing paper one sheet at a time, and controls the printing paper fed from the printing paper tray. Operates the moving unit and stops the operation of the moving unit for the printing paper as the slip sheet fed from the slip sheet feeding tray, so that the printing sheet fed from the printing sheet feeding tray is stopped. Unprinted sheets fed from the slip sheet feed tray are sandwiched between the finished sheets as slip sheets.

According to the third aspect of the present invention, when the grouping mode is selected and printing is performed by designating the number of groups and the number of prints per group, the control means performs printing of the first group. Until the operation is completed, the moving means is operated, and after the printing of the first group is completed, when the sheet feeding device feeds one sheet of printing paper as the slip sheet, the operation of the moving means is stopped, and then the operation of the next group is stopped. At the time of printing, since the moving unit is operated again, unprinted paper is sandwiched between the groups.

According to the fourth aspect of the present invention, a grouping mode is selected, and a printing paper tray and an interleaf paper feeding tray are respectively designated from a plurality of paper feeding trays.
Further, when printing is performed by designating the number of groups and the number of prints in each group, the control unit supplies the paper from the printing paper supply tray and activates the moving unit for the printing of the first group, After the printing of the first group is completed, one sheet of printing paper is inserted from the sheet feeding tray.
The paper is fed and the operation of the moving means is stopped.
At the time of printing of the next group, since the moving means is operated again, between the groups of printed papers fed from the printing paper feed tray, there is no printing fed from the slip paper feeding tray. The paper is inserted as a slip sheet.

According to the fifth aspect of the present invention, a grouping mode is selected, and a printing paper tray and an interleaf paper feeding tray are respectively designated from a plurality of paper feeding trays.
Further, when printing is performed by designating the number of groups and the number of prints in each group, the control unit supplies the paper from the printing paper supply tray and activates the moving unit for the printing of the first group, After the printing of the first group is completed, the sheet is moved by the sheet feeding tray moving means, and one sheet of printing paper is fed from the printing sheet feeding tray and the slip sheet feeding tray whose feeding position is changed to one sheet. At the same time, the operation of the moving means is stopped, and then when printing the next group,
Since the moving means is operated again, unprinted paper fed from the interleaf paper feed tray is interposed between the groups of printed paper fed from the print paper feed tray.
The position is shifted and sandwiched as interleaving paper.

According to the sixth aspect of the present invention, the sorting mode is selected, and the sheet feeding order, the number of sheets to be fed, and the number of sheets of the plurality of sheet feeding trays are respectively designated, and the sheets are fed from each sheet feeding tray. When the paper is sorted, the control means causes the paper to be fed from each paper feed tray in accordance with the specified paper feeding order, the number of papers to be fed, and the number of papers to be sorted, and controls the paper fed from each paper feed tray. Since the operation of the moving means is stopped, the paper is sequentially conveyed without being printed.

[0020]

1 shows an embodiment of the present invention. A printing apparatus 1 includes a paper feeding device 2, a printing unit 3, and a paper discharging unit 4. In this embodiment, in addition to the paper feeding device 2 provided integrally with the housing 5 of the printing apparatus 1, a paper feeding device 6 having a different structure from the housing 5 as shown in FIG. doing.

The paper feeder 2 mainly comprises a paper feed tray 7, a paper feed roller 8, a separation pad 9, a pair of registration rollers 10, and the like. The paper feed tray 7 is detachably attached to the housing 5, and print paper P is stacked on a paper feed table 7 a provided inside. The paper feed tray 7 is configured in the same manner as a paper feed tray 37 described later, and the loaded printing paper P is pressed against the paper feed roller 8 by a vertical movement mechanism 42 described later. The paper feed table 7a is movably supported by a paper feed tray moving means 41 described later. The paper feed roller 8 is driven to rotate by a driving unit (not shown), and picks up and feeds the printing paper P that comes into contact with the outer peripheral surface thereof.
The operation of the driving means for driving the paper feed roller 8 is controlled by control means described later. When the feed roller 8 feeds the printing paper P, the printing paper P is prevented from being double fed by the separation pad 9. A paper transport path 11 is formed on the left side of the paper feed roller 8 and the separation pad 9, and a registration roller pair 10 that is rotated and driven by a driving unit (not shown) is provided on the left side. A paper transport path 12 that guides the printing paper P to the printing unit 3 is formed on the left side of the registration roller pair 10 and near the printing unit 3. Below the paper transport path 12, a paper sensor 13 for detecting whether or not the printing paper P is present inside the paper transport path 12 is provided. The signal output from the paper sensor 13 is input to control means described later. The paper transport path 11 is
It branches downward from the end on the side of the pair of registration rollers 10 to form a paper transport path 14. The paper transport path 14 is provided so as to open at the lower part of the housing 5, and a rotatable transport roller pair 15 is provided in the middle of the paper transport path 14.

A printing section 3 is provided on the left side of the sheet feeding device 2. The printing unit 3 mainly includes a printing drum 16, a press roller 17, and the like. The printing drum 16
It is rotatably supported by a side plate (not shown), and is rotatably driven by driving means (not shown). As shown in FIG. 2, a press roller 17 is provided below the printing drum 16. The press roller 17 is formed such that its width is substantially the same as the width of the printing drum 16.
A shaft 17a is inserted and fixed at the center. Both ends of the shaft 17a are rotatably supported by guide members 18,18. A center shaft 19 is fixedly inserted through ends of the guide members 18, 18 opposite to the ends supporting the shaft 17a. The center shaft 19 is rotatably supported by a side plate (not shown) of the housing 5, and has a
An operation plate 20 is fixed at one end. Operating plate 20
Is a thin plate member formed in a vertically long shape, and a shaft 21 a for rotatably supporting the cam follower 21 is fixed to an end opposite to the end fixed to the central shaft 19. The operation plate 20 is formed such that both side portions protrude, and one end of a tension coil spring 22 is engaged with the protrusion 20 a on the print drum 16 side. Extension coil spring 22
Is fixed to a side plate (not shown) of the housing 5,
A biasing force in the counterclockwise direction in FIG. 2 is applied to the operation plate 20 about the central axis 19. The protruding portion 20b of the operation plate 20 on the paper feeder 2 side is capable of engaging and disengaging with a locking member 29 described later.

A printing pressure gear 23 is disposed further behind the operation plate 20 than the apparatus. The printing pressure gear 23 is rotatably supported by a side plate (not shown), and has a pinion 2 fixed to an output shaft end of a motor 24 mounted on the housing 5.
The rotation force is transmitted from the motor 5 and the printing drum 16 is driven to rotate in synchronization with the printing drum 16. A printing pressure cam 26 is arranged coaxially with the printing pressure gear 23 in front of the printing pressure gear 23. The printing pressure cam 26 is a plate member having a substantially figure-eight shape, and is rotationally driven by transmitting the rotational force of the motor 24. Printing pressure cam 2
6, a tension coil spring 2 is provided on the track formed on the outer peripheral surface.
The outer peripheral surface of the cam follower 21 urged in 2 abuts. The above-mentioned operation plate 20, cam follower 21, tension coil spring 22, printing gear 23, motor 24, pinion 2
5. The moving means 27 is constituted by the printing pressure cam 26 and the like.

An engaging means 28 is provided near the paper feeding device 2 side of the moving means 27. The locking means 28 mainly includes a locking member 29, a solenoid 30, a tension coil spring 31, and the like. The locking member 29 is a plate material having a substantially L-shape, and is rotatably supported by the support shaft 32 at a bent portion thereof. The support shaft 32 is implanted on a side plate (not shown) of the housing 5. One end of a tension coil spring 31 is engaged with one end 29 a of the locking member 29, and the other end of the tension coil spring 31 is attached to a side plate of the housing 5. Thereby, the locking member 29 is given a biasing force in the counterclockwise direction about the support shaft 32 in FIG. The end of the plunger 30a of the solenoid 30 is rotatably attached to the one end 29a by a shaft 33. As a result, the locking member 29 has one end 29a.
Are supported by a solenoid 30, a tension coil spring 31, and a support shaft 32 such that the horizontal axis is substantially horizontal. Locking member 2
The other end 29b of 9 extends downward from the bent portion, and a cutout portion 29c is formed in the upper side edge. The notch 29 c has a protrusion 20 of the operation plate 20.
b is detachable. The solenoid 30 is connected to the housing 5
The operation is controlled by control means described later.

At the lower left of the printing unit 3, a paper discharging unit 4 is provided. The paper discharge unit 4 mainly includes a suction conveyance unit 34 and a paper discharge tray 35. Suction transport unit 3
Numeral 4 is attached to the housing 5 to separate the printed printing paper P from the outer peripheral surface of the printing drum 16 and
It has a well-known structure in which the printing paper P is sewn to the outside after being sewn to improve the paper ejection alignment. Output tray 3
Reference numeral 5 is removably attached to the housing 5, and sequentially stacks printed printing papers P discharged outside the apparatus by the suction conveyance unit 34.

An operation panel 66 is provided on the upper surface of the housing 5. As shown in FIG. 3, the operation panel 66 performs a predetermined number of prints per one original, with a slip sheet key 67 for selecting a slip sheet mode for inserting a slip sheet between printed sheets. Grouping key 68 for selecting a grouping mode, inserting a predetermined number of sheets sequentially from a plurality of paper trays, and selecting a sorting mode. Key 69a, a tray selection key 70 for selecting a tray to be used from a plurality of paper feed trays, a leftward movement key 71a for moving the paper supply tray provided on the paper supply tray to the left, and a rightward movement. Right arrow key 7
1b, a paper tray moving key 71, a message display 72 for displaying print information, a ten key 73 for setting print conditions, and a start key 7 for starting printing.
4. A plate making start key 82 for starting a plate making operation is arranged. Control means 76 is provided below the operation panel 66 and inside the housing 5. The control means 76, as shown in FIG.
It mainly comprises a RAM 78 and a ROM 79.

Below the housing 5, a paper feeder 6 of another structure is connected. The paper feeding device 6 mainly includes an apparatus main body 36, a plurality of paper feeding trays 37, 37, a paper feeding roller 8 similar to the paper feeding device 2, a separation pad 9, a transport roller pair 15, and the like. As shown in FIG. 5, the paper feed tray 37 includes a paper feed table 38, a paper feed bottom plate 39, side guide plates 40 and 40,
It mainly comprises a paper feed tray moving means 41, a vertical movement mechanism 42 and the like.

A guide shaft 43 is provided between the side plates 37a and 37b of the paper feed tray 37. The guide shaft 43 is inserted through the side plates 38 a and 38 b of the paper feed table 38, and the paper feed table 38 is supported by the guide shaft 43 so as to be slidable in the arrow X direction. In the middle part of the paper supply table 38, a paper supply bottom plate 39 on which the printing paper P is loaded is disposed on the upper part thereof. The sheet feeding bottom plate 39 is engaged with elongated holes formed in the side plates 38a and 38b by protrusions 39a and 39b provided on both sides thereof, and is supported by a vertically moving mechanism 42 described later so as to be vertically movable. I have. On the upper surface of the paper feed bottom plate 39,
Side guide plate 4 for positioning printing paper P in the width direction
0 and 40 are provided. Side guide plates 40, 40
Is a well-known configuration provided symmetrically from the center of the printing paper P and both movable in the arrow X direction.

A paper feed tray moving means 41 is provided at a lower portion inside the paper feed table 38. Paper feed tray moving means 41
Is a motor 44, a ball screw 45, a slit disk 4
6. It mainly comprises a slit sensor 47 and the like.
The motor 44 is supported by a motor bracket 48, and the motor bracket 48 is
8c. Output shaft 44 of motor 44
a is connected via a joint 49 to a shaft 50 on which a ball screw 45 is engraved.
5 is rotatably supported by a support member 51 mounted on the bottom plate 38c, and has free ends at its both ends.
A slit disk 46 is fixedly provided. A substantially L-shaped bracket 52 having one surface fixed on the bottom plate of the paper feed tray 37 is screwed to the ball screw 45. With this configuration, the ball screw 45 rotates with respect to the immovable bracket 52 by the rotational force of the motor 44, and the paper feed table 38 can move on the guide shaft 43 in the arrow X direction. The operation of the motor 44 is controlled by the control means 76.

As shown in FIG. 6, a plurality of slits 53 are formed radially at equal intervals in the slit disk 46. A slit sensor 47 that counts the slits 53 is provided at a position facing the slit 53, and the slit sensor 47 is fixed on the bottom plate 38c. The slit disk 46 and the slit sensor 47 constitute a movement amount detecting means 54. Also, the bottom plate 38
c, an initial position indicating plate 80 is fixed on the lower surface of the sheet feed tray 37, and an initial position sensor 81 is mounted on the bottom plate of the paper feed tray 37. By providing the initial position indicating plate 80 at a position where the center coincides with the center in the X direction, the displacement of the document image with respect to the printing paper P can be corrected by moving the paper feed table 38 by the motor 44.

The vertical movement mechanism 42 includes a gear motor 55, a worm 56, and a worm wheel shaft 5 as shown in FIG.
7, hub 58, fixed pulleys 59, 59, 59, moving pulley 60,
60, a wire 61, a pulse generator 62, a remaining amount sensor 63, and the like. Gear head 5
The gear motor 55 having 5a is fixed on the bottom plate 38c, and its operation is controlled by the control means 76. The worm 56 has one end connected to the gear head 55a, and a pulse generator 62 fixed to the other end. A remaining amount sensor 63 is provided at a position facing the pulse generator 62, and the remaining amount sensor 63 is mounted on the bottom plate 38c. The pulse generator 62 and the remaining amount sensor 63 constitute a paper detecting unit 65. Worm wheel shaft 5 having a worm wheel 57a engaged with the worm 56
7 are brackets 64, 64 fixed on the bottom plate 38c.
, And is disposed so as to penetrate the side plate 38a and the side plate 38b (not shown). A hub 58 is mounted near the side plate 38 a of the worm wheel shaft 57, and a hub (not shown) is mounted on the other side of the side plate 38 b, similarly to the hub 58.

The side plate 38a is provided with two vertically formed
Three long holes 38d, 38d are formed. Each long hole 38
d, 38d, and a lower part between the long holes, a fixed pulley 5
9, 59, 59 are rotatably mounted, and the moving pulleys 60, 60 are loosely fitted in the respective elongated holes so as to be movable in the vertical direction. The protrusions 39a and 39 of the feed bottom plate 39 described above.
“a” is supported by the moving pulleys 60 and 60. A wire 61 is wound around each fixed pulley and each moving pulley. One end of the wire 61 is fixed to the hub 58, and the other end is fixed to one moving pulley 60. This hub, constant pulley,
The structures of the moving pulley and the wire are symmetrically formed also on the side plate 38b side. With this configuration, the gear motor 5
When the worm wheel shaft 57 rotates counterclockwise in FIG. 7 with the rotation of 5, the wire 61 is wound around the hub 58, and the moving pulleys 60 are raised, so that the protrusions 39a, 39a are pushed up, and the supply is performed. The paper bottom plate 39 rises.

The printing paper P fed from the paper feed trays 37, 37 is fed to a paper transport path 7 formed inside the paper feeding device 6.
5, and is carried to the registration roller pair 10 via the sheet conveyance path 14 opened at the lower part of the housing 5.

The operation based on the above configuration will be described below. As a first embodiment, a case where printing is performed in the slip sheet mode will be described. Prior to printing, the operator sets a document on an image reading device (not shown), presses a plate making start key 82 on the operation panel 66, winds a plate made master on the outer peripheral surface of the printing drum 16, and then inserts a slip sheet key. Pressing 67 (when the master having already made a plate has already been wound on the outer peripheral surface of the printing drum 16, the pressing of the plate making start key 82 is omitted). The signal is judged by the CPU 77, the print data is read from the ROM 79, and an instruction is issued to set the number of trays to be used on the message display 72, the designated tray number, and the number of prints. On the other hand, the operator designates the number of trays using the ten keys 73. Here, a case where one tray is selected will be described. Next, the operator selects and specifies the tray to be used with the tray selection key 70, sets the number of prints with the ten keys 73, and then presses the start key 74. The input information specified here is input to the RAM 78.

When the start key 74 is pressed, the selected paper feed tray (any tray may be used,
Up and down mechanism 4 provided in the upper stage is selected)
The gear motor 55 rotates, and the wire 61 is connected to the hub 5.
8 and the moving pulleys 60, 60 are raised. As the movable pulleys 60 are raised, the paper feed bottom plate 39 is raised and the upper surface of the loaded printing paper P comes into contact with the paper feed roller 8, and the pressure on the paper feed roller 8 is a predetermined pressure stored in the ROM 79. At this point, the rotation of the gear motor 55 is stopped, and the raising of the sheet feeding bottom plate 39 is stopped. At this time, when the worm 56 rotates, the pulse generator 62 rotates to generate a pulse, and the remaining amount sensor 63 counts the number of pulses. The amount of movement of the paper feed bottom plate 39 changes according to the number of loaded printing papers P, and the number of pulses generated accordingly changes. Therefore, the number of printing papers P is detected, and this signal is sent to the RAM 78. . Then, from this signal, the remaining number of print papers P becomes smaller or becomes zero.
When the CPU 77 determines that the operation
A printing paper replenishment lamp (not shown) provided on the lamp 6 is turned on.

When the feed bottom plate 39 stops rising and the printing paper P
Is pressed against the paper feed roller 8 at an appropriate pressure, a command is issued from the control means 76, and the paper feed roller 8 rotates to feed the printing paper P. At this time, the printing paper P is separated one by one by the separation pad 9 and fed to the paper transport path 14. Paper transport path 1
The printing paper P sent to 4 is transported by the transport roller pair 15, and when the leading end reaches a position where it comes into contact with the registration roller pair 10, a signal is output from the control unit 76 and the transport roller pair 15 is stopped. .

A printing operation is performed in the printing unit 3 in parallel with the paper feeding operation of the paper feeding device 6. In accordance with the rotation of the printing drum 16, the registration roller pair 10 stopped
Rotates, and feeds the printing paper P from the paper transport path 12 between the printing drum 16 and the press roller 17. At this time, when the leading edge of the printing paper P crosses the paper sensor 13, the paper sensor 13 outputs a signal.
78 is input. The signal input to the RAM 78 is C
The PU 77 compares the print data with the print data stored in the ROM 79, sends a signal from the CPU 77 based on the print data, and energizes the solenoid 30.

The solenoid 30 attracts the plunger 30a when energized. Then, the locking member 29 is rotated clockwise around the support shaft 32 against the urging force of the extension coil spring 31, and the operating plate in which the notch 29 c of the locking member 29 locks the protruding portion 20 b. The lock 20 is unlocked and rotated counterclockwise about the central axis 19 by the urging force of the extension coil spring 22. By the rotation of the operation plate 20, the outer peripheral surface of the cam follower 21 comes into contact with the outer peripheral surface of the printing pressure cam 26, and the operation plate 20 is swung along the printing pressure cam 26,
The press roller 17 is moved to a second position where its outer peripheral surface contacts the outer peripheral surface of the printing drum 16.

The printing drum 1 is pressed by the press roller 17.
The printing paper P to which the print image has been transferred by being pressed against the outer peripheral surface of the printing drum 6 is separated from the outer peripheral surface of the printing drum 16 by a separating claw (not shown) arranged near the outer peripheral surface of the printing drum 16, and then is suction-conveyed. The sheet is conveyed while being crimped by the unit 34, and is discharged onto a discharge tray 35 outside the apparatus.

The printing drum 16 makes approximately three-quarters of a turn from the time when the press roller 17 contacts the outer peripheral surface of the printing drum 16, and the time when the most protruding portion of the printing pressure cam 26 comes into contact with the cam follower 21, At the time when the notch 29c of the stop member 29 and the protruding portion 20b of the operation plate 20 can be locked, a signal is sent from the control means 76 and the energization to the solenoid 30 is cut off. Then, the locking member 29 is rotated counterclockwise by the urging force of the extension coil spring 31, and locks the protruding portion 20b of the operation plate 20 into the notch 29c. As a result, the press roller 17 is held at the first position where the outer peripheral surface of the print drum 16 is separated from the outer peripheral surface of the print drum 16.

After the printing of the first sheet is completed, the printing of the second sheet is performed. Similarly to the first sheet, the second sheet of printing paper P is conveyed to the registration roller pair 10 and timed with the printing drum 16, and then the printing sheet P is pressed by the registration roller pair 10 with the printing drum 16. It is fed between the rollers 17. At this time, similarly to the first sheet, a signal is output from the sheet sensor 13 and the signal is input to the RAM 78. The signal input to the RAM 78 is compared with the print data stored in the ROM 79 by the CPU 77. However, this print data is different from the print data of the first sheet, so that the power to the solenoid 30 is not turned on. Has become. Therefore, the press roller 17 does not move while being held at the first position, and the printing paper P
After passing through the space between the press roller 6 and the press roller 17 and being conveyed to the suction conveyance unit 34, the paper is discharged onto a paper discharge tray 35.

Thereafter, the third printing is performed in the same manner as the first printing,
The fourth print is performed up to the set number of prints in the same manner as the second print. As described above, the print data indicating that the press roller 17 is moved during the printing of the odd-numbered sheets and the press roller 17 is not moved during the printing of the even-numbered sheets is stored in the ROM 79. Are stacked on the paper discharge tray 35 alternately. As a result, the excess ink on the printed paper is absorbed by the unprinted paper serving as the slip sheet, thereby preventing the problem of show-through of the ink.

As a second embodiment, a case will be described in which each item is set prior to printing in the same manner as in the first embodiment, and two trays are selected with the ten keys 73 when setting the number of trays to be used. . The operator uses the tray selection key 7
At 0, the printing paper tray and the interleaving paper tray are selected and designated, and the start key 74 is pressed. Start key 7
When the button 4 is pressed, the vertical movement provided on each of the selected trays (the upper tray of the paper feed tray 37 is selected as the paper feed tray for printing and the paper feed tray 7 is selected as the paper feed tray for interleaving paper) is selected. Each of the mechanisms 42 operates to press the printing paper P against the paper feed roller 8 in the same manner as in the first embodiment.

When the printing paper P is pressed against the paper feed roller 8 at an appropriate pressure, a command is issued from the control means 76 to rotate the paper feed roller 8 and feed the print paper P from the upper stage of the paper feed tray 37. I do. The printing paper P sent to the paper transport path 14 is transported by the transport roller pair 15, and when the leading end reaches a position where it comes into contact with the registration roller pair 10, a signal is output from the control unit 76 and the transport roller pair 15 is moved. Stopped. The stopped registration roller pair 10 rotates in accordance with the rotation of the printing drum 16, and feeds the printing paper P from the paper transport path 12 between the printing drum 16 and the press roller 17. At this time, the paper sensor 13 outputs a signal when the leading end of the printing paper P crosses the paper sensor 13, and the signal is input to the RAM 78. The signal input to the RAM 78 is compared with the print data stored in the ROM 79 by the CPU 77, and based on the print data,
A signal is sent from U77 to energize the solenoid 30. When the solenoid 30 is energized, the press roller 17 is moved to the second position, and the document image is transferred to the printing paper P fed from the upper stage of the paper feed tray 37. Thereafter, the printing paper P is transferred to the suction conveyance unit 34.
The sheet is conveyed while being tied up, and is discharged onto the sheet discharge tray 35. The press roller 17 is again positioned at the first position as in the first embodiment.

When the printing paper P fed from the upper stage of the paper feeding tray 37 is discharged onto the paper discharging tray 35, the printing paper P as a slip sheet is then fed from the paper feeding tray 7. When the leading end of the printing paper P sent to the paper transport path 11 reaches a position where the leading end of the printing paper P comes into contact with the registration roller pair 10, a signal is output from the control means 76 and the paper feeding roller 8 is stopped.
The stopped registration roller pair 10 rotates in accordance with the rotation of the printing drum 16, and the printing paper P is transferred to the paper transport path 1.
2 to feed between the printing drum 16 and the press roller 17.

At this time, a signal is output from the paper sensor 13, and this signal is
The print data stored in the ROM 79 is compared with the print data 77, and the print data is not supplied to the solenoid 30. Accordingly, the press roller 17 does not move while being held at the first position, and the printing paper P fed from the paper feed tray 7 passes between the printing drum 16 and the press roller 17 and is suction-conveyed. After being transported to the unit 34, the paper is discharged onto a paper discharge tray 35.

As described above, the press roller 17 is moved when printing the printing paper P fed from the printing paper feed tray, and is pressed when printing the printing paper P fed from the slip paper feeding tray. Is stored in the ROM 79 so that printed paper and unprinted paper are alternately stacked on the paper discharge tray 35. As a result, the excess ink on the printed paper is absorbed by the unprinted paper serving as the slip sheet, thereby preventing the problem of show-through of the ink. Further, waste paper can be used as the printing paper P as the slip sheet.

As a third embodiment, a case where printing is performed in the grouping mode will be described. Prior to printing, the operator sets a document on an image reading device (not shown),
After pressing the plate making start key 82 of the operation panel 66 and winding the plate made master on the outer peripheral surface of the printing drum 16,
The grouping key 68 is pressed. The signal is sent to the CPU 77
The print data is read from the ROM 79 and an instruction is issued to set the number of trays to be used for printing on the message display 72, the designated tray number, the number of groups, and the number of prints per group. On the other hand, the operator designates the number of trays with the ten keys 73. Here, a case where one tray is selected will be described. Next, the operator selects and specifies the tray to be used with the tray selection key 70, sets the number of groups and the number of prints per group with the ten keys 73, and then presses the start key 74.

In the same manner as in the above embodiments, the vertical movement mechanism 42 provided on the selected paper feed tray (the upper stage of the paper feed tray 37 is selected) operates to feed the printing paper P to the paper feed roller 8. Pressure contact. After the printing paper P is pressed against the paper feed roller 8 with an appropriate pressure, the print paper P is transported by the paper feed roller 8 and the transport roller pair 15 to a position where it comes into contact with the registration roller pair 10.
Thereafter, the printing paper P is sent between the printing drum 16 and the press roller 17 by the registration roller pair 10, and
The sensor 13 outputs a signal. This signal is stored in RAM7
8 and collated by the CPU 77 with the print data stored in the ROM 79. A signal is sent from the CPU 77 based on the print data, and the solenoid 30 is energized. When the solenoid 30 is energized, the press roller 17 is moved to the second position.
The original image is transferred onto the printing paper P fed from the upper stage of FIG. This operation is repeated until the number of printed sheets for one group input to the RAM 78 is exhausted.

When the number of printed sheets for one group input to the RAM 78 is exhausted, the CPU 77 cuts off the power supply to the solenoid 30 and puts the printing paper P in the state where the press roller 17 is positioned at the first position. Pass only one sheet. Thereafter, the CPU 77 re-energizes the solenoid 30 in the same manner as described above, and printing of the next group is performed. When the number of prints for this group is exhausted again, the CPU 77 cuts off the power supply to the solenoid 30, and
With the press roller 17 positioned at the first position, only one print sheet P is passed. RAM above operation
By storing in the ROM 79 print data that repeats up to the number of groups input to the group 78, unprinted sheets are inserted as interleaving sheets between the groups constituted by a plurality of printed sheets. The grouping of the printed sheets can be performed without using a separating device.

As a fourth embodiment, a case will be described in which each item is set prior to printing in the same manner as in the third embodiment, and two trays are selected with the ten keys 73 when setting the number of trays to be used. . The operator uses the tray selection key 7
At 0, the printing paper tray and the interleaving paper tray are selected and designated, and the start key 74 is pressed. Start key 7
When the button 4 is pressed, the vertical movement provided on each of the selected trays (the upper tray of the paper feed tray 37 is selected as the paper feed tray for printing and the paper feed tray 7 is selected as the paper feed tray for interleaving paper) is selected. The mechanisms 42 operate, respectively, to press the printing paper P against the paper feed roller 8 in the same manner as in the above-described embodiments.

The printing paper P fed from the upper stage of the paper feed tray 37 is pressed against the paper feed roller 8 at an appropriate pressure, and then is brought into contact with the registration roller pair 10 by the paper feed roller 8 and the transport roller pair 15. Transported to Then, the printing paper P
Is sent between the printing drum 16 and the press roller 17 by the registration roller pair 10 to cause the sensor 13 to output a signal. This signal is input to the RAM 78 and the CP
In U77, the print data is collated with the print data stored in the ROM 79. A signal is sent from the CPU 77 based on the print data, and the solenoid 30 is energized. When the solenoid 30 is energized, the press roller 17 is moved to the second position, and the document image is transferred to the printing paper P fed from the upper stage of the paper feed tray 37. This operation is repeated until the number of printed sheets for one group input to the RAM 78 is exhausted.

When the number of printed sheets for one group input to the RAM 78 has been exhausted, the CPU 77 cuts off the power supply to the solenoid 30 and places the press roller 17 at the first position in the sheet feed tray. 7 passes only one sheet of printing paper P as a slip sheet. Thereafter, the CPU 77 again operates the solenoid 30 as described above.
, And printing of the next group is performed. When the number of prints for this group is exhausted again, C
The PU 77 cuts off the power supply to the solenoid 30 and passes only one print sheet P from the sheet feed tray 7 in a state where the press roller 17 is positioned at the first position. By storing in the ROM 79 the print data that repeats the above operation up to the number of groups input to the RAM 78, it is possible to print between groups formed by a plurality of printed sheets.
An unprinted sheet is inserted as a slip sheet, so that the printed sheets can be grouped without using a grouping device. In addition, waste paper or colored paper can be used as the printing paper P as the slip sheet.

As a fifth embodiment, prior to printing, each item is set in the same manner as in the fourth embodiment, and when setting the number of trays to be used, two trays are selected with the ten keys 73, and The case where the paper movement mode is selected will be described.
The operator uses the tray selection key 70 to select and specify the printing paper tray and the interleaf paper feeding tray, respectively, according to the instructions on the message display 72. Then, when specifying the paper feed tray for interleaf paper (the upper stage of the paper feed tray 37 is selected), the interleaf paper transfer mode is selected.

When the slip sheet moving mode is selected, a command is issued from the control means 76, and the shaft 50 is rotated by the rotational force of the motor 44.
The ball screw 45 engraved on the paper tray rotates,
The paper feed table 38 moves in the set direction of FIG. Axis 5
With the rotation of 0, the slit disk 46 also rotates, and the slit sensor 47 counts the number of slits 53, so that the amount of movement of the sheet supply table 38 is detected. The movement amount detected by the movement amount detection means 54 is input to the RAM 78 and is
The CPU 77 outputs a movement stop command from the CPU 77 when the movement amount and the setting data match when the data is compared with the data set in M79.

Thereafter, when the start key 74 is pressed,
Each of the selected trays (the lower row of the paper feed tray 37 as a print paper feed tray is the
The upper and lower moving mechanisms 42 provided in the upper stage 7 are respectively operated, and the printing paper P is pressed against the paper feed roller 8 in the same manner as in each of the above embodiments.

The printing paper P fed from the lower stage of the paper feed tray 37 is pressed against the paper feed roller 8 at an appropriate pressure, and then comes into contact with the registration roller pair 10 by the paper feed roller 8 and the transport roller pair 15. Transported to Then, the printing paper P
Is sent between the printing drum 16 and the press roller 17 by the registration roller pair 10 to cause the sensor 13 to output a signal. This signal is input to the RAM 78 and the CP
In U77, the print data is collated with the print data stored in the ROM 79. A signal is sent from the CPU 77 based on the print data, and the solenoid 30 is energized. When the solenoid 30 is energized, the press roller 17 is moved to the second position, and the document image is transferred to the printing paper P fed from the upper stage of the paper feed tray 37. This behavior is
This process is repeated until the number of printed sheets for one group input to the RAM 78 is exhausted.

When the number of printed sheets for one group input to the RAM 78 has been exhausted, the CPU 77 cuts off the power supply to the solenoid 30 and places the press roller 17 at the first position in the feed tray. Only one sheet of printing paper P as a slip sheet fed from the upper stage of 37 is passed. The printing paper P as the slip sheet discharged onto the paper discharge tray 35 is discharged with the discharge position of the printed paper shifted from a direction perpendicular to the paper discharge direction. Then CPU7
At 7, the solenoid 30 is energized again in the same manner as described above, and printing of the next group is performed. When the number of prints for this group has been exhausted again, the CPU 77 cuts off the power supply to the solenoid 30 and prints the print paper from the upper stage of the paper feed tray 37 with the press roller 17 positioned at the first position. P, and only one sheet passes through the discharge tray 35.
Discharge up. By storing in the ROM 79 print data that repeats the above operation up to the number of groups input to the RAM 78, unprinted paper is inserted as a slip sheet between each group composed of a plurality of printed papers,
This makes it possible to perform grouping of printed sheets without using a grouping device. In addition, waste paper or colored paper can be used as the printing paper P as the slip sheet, and printed paper can be easily taken out for each group.

As a sixth embodiment, a case where sheets are sorted in the sorting mode will be described. Prior to the sorting, the operator presses a sorting key 69 on the operation panel 66. The signal is input to the RAM 78, judged by the CPU 77, the print data is read out from the ROM 79, and the number of trays to be used for the message display 72, the designated tray number, the sheet feeding order from each designated tray, and the An instruction is issued to set the number of sheets to be fed and the required number of divisions. On the other hand, the operator designates the number of trays using the ten keys 73. Next, the operator:
The tray to be used with the tray selection key 70 is
Then, the number of sheets to be fed is input for each designated tray, the sheet feeding order is specified by the tray selection key 70, the number of sheets is input by the ten keys 73, and then the start key 74 is pressed.

When the start key 74 is pressed, each of the selected trays (the upper stage of the paper feed tray 37 and the lower stage of the paper feed tray 37 is selected, and the paper is fed from the upper stage of the paper feed tray 37 first. The vertical movement mechanisms 42 provided at the designated positions are respectively operated, and the printing paper P is pressed against the paper feed rollers 8 as in the above embodiments. At this time, not the printing paper P but the paper to be sorted is loaded on each paper feed tray. Printed paper may be used as the paper to be sorted.

In accordance with the designated sheet feeding order, the sheet feeding tray 37
The paper fed from the upper stage is pressed against the paper feed roller 8 at an appropriate pressure, and then conveyed by the paper feed roller 8 and the conveying roller pair 15 to a position where it comes into contact with the registration roller pair 10. Thereafter, the sheet is fed between the printing drum 16 and the press roller 17 by the registration roller pair 10 and causes the sensor 13 to output a signal. This signal is input to the RAM 78 and collated by the CPU 77 with the print data stored in the ROM 79. CPU based on this print data
A signal is sent from 77, but at this time, power is not supplied to the solenoid 30. Therefore, the press roller 17 remains held at the first position, and the image is not transferred to the sheet fed from the upper stage of the sheet feed tray 37, but is discharged onto the sheet discharge tray 35 as it is. This operation is performed in the RAM 7
This process is repeated until the number of sheets fed in 8 is exhausted.

When the number of sheets fed for one group input to the RAM 78 is exhausted, the CPU 77 stops the sheet feeding roller 8 for feeding sheets from the upper stage of the sheet feeding tray 37, and stops the lower stage of the sheet feeding tray 37. The paper feed roller 8 for feeding more paper is rotated. The paper fed from the lower stage of the paper feed tray 37 is sent between the printing drum 16 and the press roller 17 by the registration roller pair 10 and causes the sensor 13 to output a signal. Then, a signal is sent from the CPU 77, but at this time, the solenoid 30 is not energized. Therefore, the press roller 17 remains held at the first position, the image is not transferred to the sheet fed from the lower stage of the sheet feed tray 37, and
Is discharged on top. This operation is repeated until the number of sheets fed to the RAM 78 is exhausted. RA operation
By storing in the ROM 79 print data that repeats until the number of divisions input to M78 has been exhausted, the paper can be classified without using a classification device.

[0063]

According to the first aspect of the present invention, when printing is performed by selecting the slip sheet mode, the control means moves every other sheet of printing paper fed from the sheet feeding device. By activating the means and pressing the printing paper with the outer peripheral surface of the drum every other sheet by the press roller, the unprinted paper is sandwiched between the printed papers, so that excess ink adhering to the printed paper is Is absorbed by unprinted paper as an interleaving sheet, so that show-through can be prevented without lowering the printing efficiency and without providing an extra device.

According to the second aspect of the present invention, when the interleaving mode is selected and printing is performed by designating the printing paper tray and the interleaving paper tray from a plurality of paper trays, respectively. The control means alternately switches between the printing paper tray and the interleaving paper tray to feed the printing paper one sheet at a time, and controls the printing paper fed from the printing paper tray. Operates the moving unit and stops the operation of the moving unit for the printing paper as the interleaf paper fed from the interleaf paper tray, so that the printed paper fed from the printing paper tray is Unprinted paper fed from the interleaf paper tray is sandwiched between the papers, so excess ink attached to the printed paper is absorbed by the unprinted paper as the interleaf paper. , Without lowering printing efficiency, and Show-through without providing a minute device can be prevented. In addition, waste paper can be used as interleaving paper, and running costs can be reduced.

According to the third aspect of the present invention, when the grouping mode is selected and printing is performed by designating the number of groups and the number of prints per group, the control means performs printing of the first group. Until the operation is completed, the moving unit is operated, and after the printing of the first group is completed, the operation of the moving unit is stopped when the sheet feeding device feeds one sheet of printing paper as an interleaving sheet. At times, by operating the moving means again, the unprinted paper is sandwiched between the groups, so that the groups can be divided without providing an extra device.

According to the fourth aspect of the present invention, the grouping mode is selected, and the printing paper tray and the interleaving paper tray are respectively designated from the plurality of paper trays.
Further, when printing is performed by designating the number of groups and the number of prints in each group, the control unit supplies the paper from the printing paper supply tray and activates the moving unit for the printing of the first group, After the printing of the first group is completed, one sheet of printing paper is inserted from the sheet feeding tray.
The paper is fed and the operation of the moving means is stopped.
At the time of printing of the next group, by operating the moving means again, between the groups of the printed paper fed from the printing paper feed tray, the non-printed paper fed from the slip paper feeding tray is not printed. Since the sheets are sandwiched as slip sheets, grouping can be performed without providing an extra device. In addition, the running cost can be reduced by using waste paper or low-grade paper as the interleaving paper, and the separation between the groups can be clarified by using colored paper as the interleaving paper.

According to the fifth aspect of the present invention, the grouping mode is selected, and the printing paper tray and the interleaving paper tray are respectively designated from the plurality of paper trays.
Further, when printing is performed by designating the number of groups and the number of prints in each group, the control unit supplies the paper from the printing paper supply tray and activates the moving unit for the printing of the first group, After the printing of the first group is completed, the sheet is moved by the sheet feeding tray moving means, and one sheet of printing paper is fed from the printing sheet feeding tray and the slip sheet feeding tray whose feeding position is changed to one sheet. At the same time, the operation of the moving means is stopped, and then when printing the next group,
By operating the moving means again, the unprinted paper fed from the interleaf paper feed tray shifts between the groups of printed paper fed from the print paper feed tray. It is sandwiched as interleaving paper, so that it is possible to perform grouping without providing extra devices, and by using waste paper or low-grade paper as interleaving paper,
The running cost can be reduced, and the use of colored paper as the interleaving paper can further clarify the division between the groups.

According to the sixth aspect of the present invention, the sorting mode is selected, and the sheet feeding order, the number of sheets to be fed, and the number of sheets of the plurality of sheet feeding trays are respectively designated, and the sheets are fed from each sheet feeding tray. When the paper is sorted, the control means causes the paper to be fed from each paper feed tray in accordance with the specified paper feeding order, the number of papers to be fed, and the number of papers to be sorted, and controls the paper fed from each paper feed tray. In other words, by stopping the operation of the moving means, the paper is sequentially conveyed without being printed,
Sheets can be sorted without providing a separate sorting device.

[Brief description of the drawings]

FIG. 1 is a schematic side view of a main part of a printing apparatus employing an embodiment of the present invention.

FIG. 2 is a partial perspective view of a printing unit illustrating one embodiment of the present invention.

FIG. 3 is a diagram of an operation panel for explaining an embodiment of the present invention.

FIG. 4 is a diagram illustrating control means according to an embodiment of the present invention.

FIG. 5 is a side sectional view of a sheet feed tray for explaining an embodiment of the present invention.

FIG. 6 is a diagram illustrating a moving amount detecting unit according to an embodiment of the present invention.

FIG. 7 is a diagram illustrating a vertical movement mechanism according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Printing apparatus 2, 6 Paper feeder 7, 37 Paper feed tray 16 Printing drum 17 Press roller 27 Moving means 76 Control means

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B41L 13/04 B41F 21/00 B41F 33/02 B65H 33/04

Claims (6)

(57) [Claims] 1. A rotatable drum, and a press roller movably provided between a first position that is an initial position separated from an outer peripheral surface of the drum and a second position that is in contact with the outer peripheral surface. And a paper feeding device for feeding the printing paper; and a moving unit for reciprocating the press roller between the first position and the second position. In a printing apparatus having a slip sheet mode for inserting a slip sheet, when printing is performed by selecting the slip sheet mode, the printing sheet fed from the sheet feeding device is alternately printed on every other sheet. A printing apparatus, comprising: control means for operating a moving means. 2. The paper feeder has a plurality of paper feed trays, selects the interleaving mode, and sets a printing paper feed tray and an interleaf paper feed tray from the respective paper feed trays. When performing printing by designating, the printing paper tray and the interleaf paper feeding tray are alternately switched so that the printing paper is fed one by one, and the printing paper tray is fed from the printing paper tray. The moving unit is operated for the fed printing paper, and the operation of the moving unit is stopped for the printing paper as the slip sheet fed from the slip sheet feeding tray. The printing apparatus according to claim 1, further comprising control means. 3. A rotatable drum, and a press roller movably provided between a first position that is an initial position away from the outer peripheral surface of the drum and a second position that is in contact with the outer peripheral surface. And a paper feeding device for feeding printing paper; and moving means for reciprocating the press roller between the first position and the second position. In a printing apparatus having a grouping mode for printing a predetermined number of sheets and inserting a slip sheet between groups of the predetermined number of printed sheets, the grouping mode is selected, and the number of groups and the number of one group are set. When printing is performed by designating the number of prints, the moving unit is operated until the printing of the first group is completed, and after the printing of the first group is completed, the paper feeding device determines that the slip sheet is inserted. A printing apparatus comprising: a control unit for stopping the operation of the moving unit when one of the printing sheets is fed, and then operating the moving unit again when printing the next group. . 4. A paper feeder having a plurality of paper feed trays, wherein the grouping mode is selected, and a print paper feed tray and an interleaf paper feed tray are respectively set from the respective paper feed trays. When printing is performed by designating and specifying the number of groups and the number of prints in each group, for printing of the first group, paper is fed from the printing paper feed tray and the moving means is operated. After the printing of the first group is completed, one sheet of the printing paper as a slip sheet is fed from the slip sheet feeding tray, and the operation of the moving unit is stopped. Thereafter, when printing the next group, 4. The printing apparatus according to claim 3, further comprising control means for operating the moving means again. 5. The grouping mode, wherein the paper feeder has a plurality of paper feed trays and a paper feed tray moving means for moving each of the paper feed trays in a direction orthogonal to a paper feed direction. Is selected, the printing paper tray and the interleaf paper feeding tray are specified from the respective paper feeding trays, and the number of groups and the number of printed sheets in one group are specified. For the printing of the group, the paper is fed from the printing paper feed tray and the moving means is operated, and after the printing of the first group is completed, the paper is moved by the paper feeding tray moving means and the printing paper feed tray is moved. From the paper tray and the paper feeding tray for which the paper feeding position has been changed, one sheet of the printing paper as the paper is fed and the operation of the moving means is stopped. 4. The printing apparatus according to claim 3, further comprising control means for operating the moving means again during printing. 6. A rotatable drum, and a press roller movably provided between a first position that is an initial position separated from the outer peripheral surface of the drum and a second position that is in contact with the outer peripheral surface. A paper feeder having a plurality of paper feed trays and feeding paper; and moving means for reciprocating the press roller between the first position and the second position. A printing apparatus having a sorting mode for sequentially feeding the sheets by a predetermined number of sheets from each of the paper feeding trays. When the number of sheets and the number of sheets are specified, and the sheets fed from each of the sheet feeding trays are sorted, the sheets are fed from each of the sheet feeding trays according to the specified sheet feeding order, the number of sheets to be fed, and the number of sheets. And each of the above For the paper fed from the paper tray, the printing apparatus characterized by comprising a control means for stopping the operation of said moving means.