JP3027537B2 - Stencil printing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stencil printing machine, and more particularly to a stencil printing machine capable of printing on both the front and back surfaces of printing paper and effectively preventing the printing surface from being stained. Regarding the ingenuity.

[0002]

2. Description of the Related Art Heretofore, there has been a stencil printing apparatus that performs printing on printing paper using a plate cylinder around which a stencil sheet made by stencil is wound.
The stencil printing machine has an advantage that the operation is so simple that it can be used in a general office and can be used with the same feeling as a so-called "copier". Accordingly, it will be described with reference to FIG. 11 the structure of a conventional stencil printing machine. First, there is a document reading unit 301, and the document reading unit 301
It is configured as a book type image scanner unit, and a document to be printed is placed on a document setting surface 303.
And the original is fixed by the cover 305. Then, an image scanner (not shown) is operated to read data shown on the document as print data.

At a position below the original reading means 301,
Plate making means 307 is provided. That is, first, there is a stencil roller 309, and a stencil sheet (hereinafter abbreviated as stencil sheet) 311 is wound around the stencil roller 309.
On the left side in FIG. 11 of the base paper roller 309, the line thermal head 313 and the platen roller 315 are opposing and arranged. Further, a stencil sheet cutter 317 and stencil sheet feed rollers 319 and 321 are opposed to each other.
A plate cylinder 323 is provided, and a plate discharging means 325 is provided on the left side in FIG. 11 with the plate cylinder 323 interposed therebetween. A plate discharging box 327 is installed in the plate discharging means 325, and plate discharging rollers 329 and 331 are opposed to and arranged at the entrance of the plate discharging box 327.

In the plate making means 307 having the above structure, the line thermal head 31 based on the print data read by the document reading means 301 described above.
3, a plurality of point heating elements selectively generate heat,
Thereby, the base paper 3 supplied from the base paper roller 309
11 is subjected to perforation and plate making. That is, the base paper 311 has, for example, a configuration in which a PET film is attached to one surface side of a nonwoven fabric, and the portion of the PET film is melted and perforated by the heat generated by the point heating element,
Plate making is performed.

The perforated and perforated stencil 311 is supplied to a platen roller 315 and stencil stencil feed rollers 319 and 321.
As a result, the sheet is conveyed in the direction of the plate cylinder 323, and its tip is clamped by a clamp mechanism 333 provided on the plate cylinder 323. When the plate cylinder 323 rotates, the base paper 311 is wound around the outer peripheral surface of the plate cylinder 323. Then, the base paper 311 is cut by the base paper cutter 317 at a location of a preset length.

On the other hand, there is a sheet feeding means 335, and the sheet feeding means 335 has a sheet feeding table 337.
7, a plurality of printing papers 339 are placed in a stacked state. A pickup roller 341 and a sub roller 343 are disposed above the printing paper 339 and on the side of the plate cylinder 323. A pad 345 for sabaki is arranged below the sabaki roller 343. The registration rollers 347 and 349 are opposed to and arranged on the plate cylinder 323 side of the sub-roller roller 345. The paper feed table 337 is configured to be able to move up and down by a drive motor and a sensor (not shown) so that the uppermost printing paper 339 is always in contact with the pickup roller 341. Then, when supplying the printing paper 339, first, the pickup roller 341 and the sabaki roller 343 are rotated by a drive motor (not shown) to send out the top printing paper 339. At this time, if two or more printing papers 339 are multiply fed, the multiply fed printing papers 339 are separated by the sabaki roller 343 and the sabaki pad 345. A printing unit 351 is provided in the plate cylinder 323, and another cylinder 353 is disposed below the plate cylinder 323 in FIG. On the discharge side of the printing paper 339, a paper discharge means 355 and a paper discharge stocker 357 are provided.

According to the above configuration, the data reading means 301
The print data is read by the
Transfer to The plate making means 307 performs perforation and plate making on the base paper 311 based on the transferred print data. The perforated and perforated base paper 311 is wound around a plate cylinder 323. On the other hand, the printing paper 339 is supplied from the paper feeding means 335 to the plate cylinder 323.
The paper is supplied by the printing unit 351 while the paper is passed therethrough, and is discharged into the discharge stocker 357 by the discharge unit 355.

[0008]

According to the above-mentioned conventional configuration, there are the following problems. Recently, from the viewpoint of effective use of resources, in printing, it is required to perform printing not only on the front surface but also on the back surface. However, in the above-described conventional stencil printing apparatus, when printing is performed on both the front surface and the back surface of the printing paper 339, an operation of inverting the printing paper 339 is required as an operation. In other words, it is necessary to turn the printing paper 339 once printed on the front side upside down and set it on the paper feeding means 335 again, and there is a problem that a complicated operation is inevitable. Further, as a stencil printing apparatus, for example, the one shown in the specification attached to the application of Japanese Patent Application No. 4-232283 has been proposed as a device for performing double-sided printing. This opposes two plate cylinders
With the arrangement, the base paper for front side printing and the base paper for back side printing are wound around each plate cylinder, printing paper is supplied between these two plate cylinders, and printing is simultaneously performed on both sides. is there. However, with such a configuration, although double-sided printing can be performed, there is a problem that the printing surface of the printing paper becomes dirty. To further explain this point, in stencil printing, water and a high boiling point (200-3)
(00 ° C) Emulsion inks prepared by adding surfactants to oils and pigments are often used. These emulsion inks are more dry than organic solvent inks used in general offset printing. There is a characteristic that is bad. In other words, when the emulsion ink is transferred to the printing paper 339, the emulsion state is broken and easily separated into water and oil. The separated water is absorbed by the fiber structure of the printing paper 339, but the separated oil is printed together with the pigment. Paper 33
9 and remained on the surface without being absorbed, and because it is hardly volatile, it is considered that the drying property of the emulsion ink is deteriorated. As described above, since the drying property after printing is poor, in the above-described double-sided printing, when the newly printed printing paper 339 is superimposed on the already printed printing paper 339, the printing of the printing paper 339 is performed. This causes a problem that the surface becomes dirty.
Further, there is a problem that the ink of the printing paper 339 also adheres to the back surface (lower side) of the printing paper 339 which is overlaid.

The present invention has been made on the basis of the above points, and an object of the present invention is to enable printing on both the front surface and the back surface of a printing paper, and to remove stains on the printing surface. It is an object of the present invention to provide a stencil printing apparatus capable of preventing the stencil printing.

[0010]

To achieve the above object, a stencil printing apparatus according to claim 1 of the present application comprises a first printing drum on which a stencil sheet is wound, and a stencil sheet on which the stencil sheet is wound. A second plate cylinder to be transferred, a transfer cylinder onto which the ink image of the second plate cylinder is transferred, and a printing sheet pressed from one surface and the other surface of the second plate cylinder via the first plate cylinder and the transfer cylinder, respectively. Stencil printing apparatus for simultaneously printing on both sides of the printing paper by transporting the printing paper between the first plate cylinder and the transfer cylinder while pressing the printing paper against each other . The first version, which is in the cylinder of the first version
With the outer peripheral surface of the cylinder projected and pressed against the transfer cylinder
The ink image of the first plate cylinder is positioned on the transfer cylinder.
A first squeegee roller for transferring to a printing paper;
The outer peripheral surface of the second plate cylinder is provided in the transfer cylinder in the second plate cylinder.
The ink image of the second plate cylinder in a protruding and pressed state.
A second squeegee roller for transferring
On the transfer cylinder, which is moved upward by the first squeegee roller.
Where the ink image of the first plate cylinder is transferred to the printing paper.
Upstream from the second squeegee roller,
The transferred ink image on the transfer cylinder and the printing paper
Supply the printing paper to the upstream position where
Printing paper supply means, and the printing paper supply means
When printing with the printing paper supplied to the transfer cylinder,
The first plate cylinder is held from the upstream position while holding the leading end of the printing paper.
Position that is in the projecting / pressing state toward the transfer cylinder
Transfer the printing paper over the downstream position
And a printing paper holding means for holding the printing paper on the body side .

[0011]

According to the present invention, on the transfer cylinder, the first
The squeegee roller raises the ink image on the first plate cylinder.
Upstream of the position to be transferred to the printing paper,
The ink on the transfer cylinder transferred by the squeegee roller
Print at the upstream position where the print image and the printing paper come into contact in advance
Print paper is supplied by the paper supply means and print paper is held
Means to hold the printing paper.
The contact time on the transfer cylinder side can be lengthened. First of all
Compared to printing directly on printing paper from the first plate cylinder
The amount of ink transferred when printing via the transfer cylinder
Tends to decrease.
Transfer ink by extending contact time
The printing from the first cylinder side and the transfer cylinder side
It is possible to eliminate variations in printing from the printer.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, with reference to FIGS. 1 to 10, a description will be given of an embodiment of the present invention. FIG. 1 is a diagram showing the appearance of a stencil printing apparatus according to the present embodiment, and the internal structure thereof is as shown in FIG. The stencil printing apparatus according to the present embodiment basically includes two plate cylinders 1, 3
(A first plate cylinder 1 and a second plate cylinder 3), and a transfer cylinder 5 disposed between these two plate cylinders 1 and 3, and the two plate cylinders 1 and 3 and the transfer cylinder 5 are transferred. Around the drum 5, document reading means 7, plate making means 9, plate discharging means 11, 13, paper feeding means 15,
It has a configuration in which printing means 17, 19, paper discharging means 21, cleaning means 22, and the like are arranged. The plate cylinders 1, 3 and the transfer cylinder 5 all have the same outer diameter.

The configuration of each section will be described in detail below. First, the document reading means 7 is configured as a book type image scanner unit, and a document to be printed is placed at a predetermined position on the document setting surface 23. And the original is fixed by the cover 25. Then, an image scanner (not shown) is operated to read data shown on the document. Alternatively, in the case of a sheet-shaped document, the sheet-shaped document is placed on the document tray 24, conveyed to a predetermined position on the document set surface 23 by a conveying means (not shown), set, and data is read in the same manner as described above. To go.

Below the original reading means 1, the above-described plate making means 9 is arranged. That is, first, there is a base paper roller 27, and the base paper roller 27
Is wound. A line thermal head 31 and a platen roller 35 are opposed to and arranged on the left side of the base paper roller 29 in FIG. Furthermore, the stencil paper cutter 37,
The stencil paper feed rollers 39 and 41 are opposed and arranged. On the left side of FIG. 2 with respect to the plate cylinder 1, the above-described plate discharging means 11 is installed.
Has a plate discharge box 43, and plate discharge rollers 45 and 47 are opposed to and arranged at the entrance of the plate discharge box 43.

In the plate making means 9 having the above structure, a plurality of dot heating elements provided on the line thermal head 31 selectively generate heat based on the print data read by the document reading means 7 already described. Thereby, the base paper 29 supplied from the base paper roller 27 is perforated and made. That is, the base paper 29 has, for example, a configuration in which a PET film is adhered to one surface side of a nonwoven fabric, and a portion of the PET film is melted and perforated by the heat generated by the point heating element, thereby forming a plate. Is what is done.

The perforated and perforated stencil 29 is conveyed in the direction of the plate cylinder 1 by a platen roller 35 and stencil feed rollers 39 and 41, and the leading end thereof is clamped by a clamp mechanism 49 provided on the plate cylinder 1. Is done. Then, as the plate cylinder 1 rotates, the base paper 29 is wound around the outer peripheral surface of the plate cylinder 1. Then, the sheet is cut by the base paper cutter 37 at a predetermined length. Since the plate discharging means 13 has the same configuration as the plate discharging means 11, the same reference numerals are given to the same parts in the figure, and the description thereof will be omitted.

Next, the configuration of the sheet feeding means 15 will be described. First, there is a paper feed table 51, and on this paper feed table 51,
A plurality of printing papers 53 are placed in a stacked state. Further, a pickup roller 55 and a sabaki roller 57 are disposed above the printing paper 53 and on the transfer cylinder 5 side. Below the sabaki roller 57, a sabaki pad 59 is arranged. Sabaki Roller 57
The registration rollers 61 and 63 are opposed to the transfer cylinder 5 side.
Are located. The paper feed table 51 is configured to be able to move up and down by a drive motor and a sensor (not shown) so that the uppermost printing paper 53 is always in contact with the pickup roller 55.

When supplying the printing paper 53, first, the pickup roller 55 and the sabaki roller 57
Are rotated by a drive motor (not shown) to feed out the uppermost printing paper 53. At this time, if two or more printing papers 53 are multi-fed, the
And the printing paper 5 double fed by the pad 59 for Sabaki
3 is separated. That is, it is set so that only one sheet of printing paper 53 can pass between the sabaki roller 57 and the sabaki pad 59. Therefore, the registration roller 6
Only one sheet of printing paper 53 is supplied to the sides 1 and 63. Then, the leading end of the supplied printing paper 53 is
When reaching the contact position between the registration rollers 61 and 63, the rotation of the pickup roller 55 and the rotation roller 57 is temporarily stopped to enter a standby state. Then, at the timing of paper feeding in accordance with the rotation timing of the plate cylinders 1 and 3 and the transfer cylinder 5, the registration rollers 61 and 63 are rotated by a drive motor (not shown) to rotate the printing paper 53. It is supplied between the cylinder 1 and the transfer cylinder 5.

Here, the rotational driving of the plate cylinders 1 and 3 and the transfer cylinder 5 will be described. First, as shown in FIG. 3, a driving motor 65 is provided, and a pulley 67 is fixed to a rotating shaft of the driving motor 65. Have been. On the other hand, a pulley 69 is coaxially fixed to the transfer drum 5 side, and a belt 71 is wound around the pulley 69 and the pulley 67. Accordingly, when the drive motor 65 is driven to rotate, the transfer cylinder 5 is rotated in the direction indicated by the arrow a in FIG. 3 via the pulley 67, the belt 71, and the pulley 69. A gear 73 is coaxially fixed to the transfer cylinder 5.
A gear 75 meshes with 3, and a gear 77 meshes with this gear 75. A gear 79 is coaxially fixed to the plate cylinder 1, and the gear 79 meshes with the gear 77. Therefore, when the transfer cylinder 5 rotates,
The plate cylinder 1 rotates in the direction indicated by the arrow b in FIG. 3 via the gears 73, 75, 77, 79.

Similarly, a gear 81 is engaged with the gear 73, and a gear 83 is engaged with the gear 81.
A gear 85 is coaxially fixed to the plate cylinder 3, and the gear 85 meshes with the gear 83. Therefore, when the transfer cylinder 5 rotates, the gears 73, 81, 83,
The plate cylinder 3 rotates in the direction indicated by the arrow c in FIG. In addition, regarding the said drive transmission mechanism,
This is merely an example, and various rotational transmission configurations are possible.

Next, the configuration of the printing units 17 and 19 will be described. Since the printing units 17 and 19 have the same configuration, the printing unit 17 will be described as an example. As shown in FIGS. 2 and 4, inside the plate cylinder 1, a squeegee roller 87, a doctor roller 89, a lift roller 91, a lift cam 93, a lift lever 95, a lever return spring 97,
A lever detection sensor 99 is incorporated. As shown in FIG. 5, frames 101 and 103 are built in the plate cylinder 1, and other frames 105 and 107 are fixed to the angle 109 by screws 111 and 113. The angle 109 is a rail 12 fixed between the frames 115 and 117 by screws 119 and 121.
5 is arranged via rollers 125 and 127 so as to be movable in the left-right direction in FIG.

The doctor roller 89 is provided between the frames 101 and 103 by bearing members 129 and 131.
Is rotatably supported via shafts 89a, 89a. Further, the squeegee roller 87 is rotatably supported between the lift levers 95, 95 by bearing members 133, 135 via shafts 87a, 87a. Further, ink 137 is appropriately supplied to a contact point between the doctor roller 89 and the squeegee roller 87 from an ink supply mechanism (not shown).

At the time of printing standby, the state is as shown in FIG. 4, in which the convex surface of the lift cam 93 pushes up the lift roller 91, and the lift lever 95 shields the sensor 99. On the other hand, at the time of printing, first, as shown in FIGS.
Are rotated by a drive motor (not shown), whereby the meshing gear 141 is rotated. Lift cam 9
3 is coaxially fixed to the gear 141, so that the rotation of the gear 141 causes the lift cam 93 to rotate. Then, the lift cam 93 rotates by 180 ° from the state shown in FIG. By the rotation of the lift cam 93, the upward bias on the lift roller 91 is released, so that the lift lever 95 is moved to the lever return spring 97.
The squeegee roller 87 is moved downward in the figure as shown in FIG. Then, the plate cylinder 1 acts so as to be pressed against the transfer cylinder 5. At the same time, the shield of the sensor 99 is released. Printing is performed in such a state.
As described above, the printing unit 19 has the same configuration, and the same parts are denoted by the same reference numerals and description thereof is omitted. However, printing on the plate cylinder 1 side is performed on the surface of the printing paper 53 supplied by the paper feeding means 15 between the plate cylinder 1 and the transfer cylinder 5, whereas The printing on the third side is performed on the transfer cylinder 5, and the image once transferred to the transfer cylinder 5 is printed on the back surface of the printing paper 53.

Next, the configuration of the paper discharging means 21 will be described. The paper discharging means 21 includes a printing paper separating claw 143 and the paper discharging guide 1.
45, a paper discharge tray 147, and a paper discharge stopper 149. The printed printing paper 53 is peeled off from the transfer drum 5 by the paper separating claw 143 when the printing paper holding means 151 provided on the transfer drum 5 opens its leading end. Printing paper 53 peeled off
Are guided by the paper ejection guide 145 and fly until they collide with the paper ejection stopper 149, and after being collided with the paper ejection stopper 149, are stacked on the paper ejection table 147. The configuration of the printing paper holding means 151 will be described later in detail.

Next, the structure of the cleaning means 22 will be described. As shown in FIG. 2, the cleaning unit 22 includes a tank 155 containing a cleaning liquid 153, cleaning rollers 157, 159, 161, a cleaning cloth 163,
The cleaning cloth take-up roller 165, the driven roller 167, the pressing roller 169, and the like are included. When cleaning is performed by the cleaning means 22 having the above configuration, first, the plate cylinders 1 and 3 and the transfer cylinder 5 are separated from each other, and the transfer cylinder 5 is rotated in the direction of arrow a by the drive motor 65. Next, the cleaning roller 161 and the pressing roller 169 are pressed against the transfer cylinder 5 by a drive motor and a clutch (not shown). Thereby, first, the cleaning liquid 153 is supplied to the cleaning rollers 157, 159, 1
The coating material is applied to the outer peripheral surface of the transfer drum 5 through the reference numeral 61. By the application of the cleaning liquid 153, the ink adhering to the outer peripheral surface of the transfer cylinder 5 is in a state where it can be easily wiped off.

Then, the cleaning cloth 163 is pressed against the transfer cylinder 5 via the pressing roller 169, and the cleaning cloth 163 is wiped off together with the cleaning liquid 153 to which the ink which has been easily wiped off is applied. Then, when the application of the cleaning liquid 153 and the wiping operation are completed within a predetermined range, the pressing of the cleaning roller 161 and the pressing roller 169 against the transfer cylinder 5 is released. Next, the cleaning cloth winding roller 1 is driven by a drive motor (not shown).
Rotate 65 to wipe off the ink and remove the dirty cleaning cloth 16
At the same time as the take-up roller 3, the unused cleaning cloth 163 is supplied to the portion of the pressing roller 169 by the driven roller 167 to prepare for the next cleaning.

Next, the configuration of the printing paper holding means 151 will be described. The printing paper holding means 151
Is configured as shown in FIGS. First, there is a transfer cylinder shaft 171, which is mounted parallel to the transfer cylinder 5. The above-described rotation transmitting pulley 6 is provided at the right end of the transfer cylinder shaft 171 in FIG.
9 is fixed. A rubber blanket 173 is attached to the outer periphery of the transfer cylinder 5, and one end of the blanket 173 is pin 1 as shown in FIG.
The other end is fixed by a screw member 177. The transfer cylinder shaft 171 has
A transfer cylinder frame 179 is fixed, and a drive base shaft 181 is attached to the transfer cylinder frame 179. A flange 183 is covered on the outer periphery of the drive base shaft 181, and a drive base 185 is fixed to the flange 183.

A cam follower shaft 187 is attached and fixed to the lower end of the drive base 185 in FIG.
A gear body 189 is fixed to the upper end by a screw member 191. On the other hand, the printing paper holding means 151
A claw shaft 193 is provided, and a plurality of claws 195 are attached to the claw shaft 193 at a predetermined pitch. The claw shaft 193 is rotatably supported by a bearing member 197 and protrudes through the bearing member 197.
A claw shaft drive gear body 199 is fixed to an end of the third shaft 3.
The claw shaft driving gear body 199 and the gear body 189 described above are in a meshing relationship. In the above configuration,
When the drive base 185 swings with the flange 183 about the drive base shaft 181, the claw shaft drive gear body 199 rotates via the gear body 189. The rotation of the claw shaft driving gear body 199 causes the claw shaft 193 to rotate, thereby rotating the plurality of claws 195.

Next, the swing of the drive base shaft 185 will be described. The cam follower 201 is attached to the tip of the cam follower shaft 187 described above, with its inner ring held. An opening / closing cam 203 is arranged above the cam follower 201 in FIG. or,
A flange 207 is fixed to the main body frame 205. The flange 207 includes a cylindrical portion 207a, and the cylindrical portion 207a is arranged so as to be covered by the outer periphery of the transfer cylinder shaft 171 described above. I have. On the other hand, the opening / closing cam 203 has a cylindrical portion 203a, and is mounted movably along the cylindrical portion 207a in a state where the cylindrical portion 203a is covered by the outer periphery of the cylindrical portion 207a of the flange 207. Have been. Also, the stopper shaft 20
The stopper shaft 209 is extended upright so as to penetrate the opening / closing cam 203. That is, the rotation of the opening / closing cam 203 is restricted by the stopper shaft 209. The opening / closing cam 2
At a predetermined position in the circumferential direction of 03, a convex portion is provided.
Also, the driving base 185 described above uses the elastic member (not shown) to connect the plurality of claws 195 to the blanket 173.
It is always urged in the direction to further separate.

According to the above configuration, when the transfer cylinder shaft 171 is driven to rotate, not only the transfer cylinder 5 but also the drive base 18 is rotated.
5 also rotates integrally. On the other hand, the opening / closing cam 20
No. 3 does not rotate synchronously with the transfer cylinder shaft 171 side and its rotation is regulated by the stopper shaft 209. The cam follower 201, which rotates integrally with the drive base 185, rotates while rolling along the outer peripheral portion of the opening / closing cam 203, and at this time, reaches the convex portion of the opening / closing cam 203.
You will get on there. As a result, the drive base 185 rotates against the urging force of the elastic member, and the gear body 1
89, the claw shaft 193 is rotated via the claw shaft drive gear body 199. As a result, the plurality of claws 195 rotate in the direction of the blanket 173 to hold the leading end of the printing paper. Then, the state in which the cam follower 189 rides on the convex portion is released, whereby the drive base 1 is released.
85 returns to the original position by the urging force of the elastic member, thereby rotating the claw shaft 193 in the reverse direction via the gear body 189 and the claw shaft drive gear body 199. Then, the holding of the printing paper by the plurality of claws 195 is released.

A pair of projections 211, 211 are provided on the cylindrical portion 203a of the opening / closing cam 203, while a cam drive plate 213 is provided.
13, a U-shaped engagement recess 213a is formed. The projection 211 is engaged with the U-shaped engagement recess 213a. Also, the cam drive plate 213
Is connected to a solenoid 215, and the excitation of the solenoid 215 causes the cam drive plate 213 to swing. The swing of the cam drive plate 213 causes the U-shaped engagement recess 213 a and the projection 211
, The opening and closing cam 203 moves along the cylindrical portion 207a of the flange 207. The sensor 21
4 is attached, and by this sensor 214,
The swing of the cam drive plate 213 is monitored.

In FIG. 9, reference numeral 217 indicates an electrostatic attraction plate. The electrostatic attraction plate 217 holds the base paper 29 for back printing which is conveyed from the plate cylinder 1 side. That is, the plate cylinder 1 has the clamp mechanism 49, and the plate cylinder 3 also has the clamp mechanism 49. Then, the base paper 29 for the front side printing is wound around the plate cylinder 1, but the base paper 29 for the back side printing is provided.
First, while being held by the clamping mechanism 49 of the plate cylinder 1, it is conveyed in the direction of the transfer cylinder 5 by rotation of the plate cylinder 1, where it is held by the electrostatic suction plate 217 of the transfer cylinder 5. At this time, the clamping mechanism 49 on the plate cylinder 1 side
Is released. Then, the sheet is conveyed toward the plate cylinder 3 by the rotation of the transfer cylinder 5, and is held by the clamp mechanism 49 of the plate cylinder 3. At this time, the holding of the transfer cylinder 5 by the electrostatic suction plate 217 is released. In this manner, the base paper 29 for backside printing is transferred from the plate cylinder 1 to the transfer cylinder 5 and from the transfer cylinder 5 to the plate cylinder 3 and wound around the outer circumference of the plate cylinder 3. It should be noted that the plate cylinder 1 already has a base paper 29 for surface printing.
Is wound, the base paper 29 for the back side printing is conveyed while being wound around the outer periphery of the base paper 29 for the front side printing.

The operation when performing double-sided printing based on the above configuration will be described. First, a document to be printed on the surface of the printing paper 53 is set on the document setting surface 23, covered with the cover 25, and in this state, the document is read by an image scanner (not shown). The read print data is converted into an electric signal and transferred to the line thermal head 31 of the plate making means 9. On the other hand, the base paper 29 is supplied from the base paper roll 27, and the base paper 29 is subjected to perforation and plate making by the line thermal head 31. Perforation
The stencil sheet 29 that has been made is conveyed in the direction of the plate cylinder 1 by rollers 39 and 41, and is sucked and held by a clamp mechanism 49 of the plate cylinder 1. Thereafter, as the plate cylinder 1 rotates, the perforated and perforated stencil 29 is wound around the outer periphery of the plate cylinder 1 and is sucked and held by the ink adhered to the surface.

Next, an original to be printed on the back side of the printing paper 53 is set on the original
Then, the original is read by an image scanner (not shown). The read print data is converted into an electric signal and transferred to the line thermal head 31 of the plate making means 9. On the other hand, the base paper 29 is supplied from the base paper roll 27, and the base paper 29 is subjected to perforation and plate making by the line thermal head 31. The perforated and perforated base paper 29 is conveyed in the direction of the plate cylinder 1 by rollers 39 and 41, and is sucked and held by the clamp mechanism 49 of the plate cylinder 1. Up to this point, the process is the same as that for the front side printing, but from there, the perforated and perforated base paper 29 is transferred to another plate cylinder 3 via the transfer cylinder 5 and wound. That is, the base paper 29 held by the clamp mechanism 49 of the plate cylinder 1 is transferred to the electrostatic attraction plate 217 of the transfer cylinder 5.
And then transferred to the clamping mechanism 49 of the plate cylinder 3, and then wound around the outer peripheral surface of the plate cylinder 3. In addition, the plate cylinder 1, the transfer cylinder 5, and the plate cylinder 3 have the same outer diameter and are configured to be synchronously driven to rotate.
Therefore, each of the clamp mechanism 49 and the electrostatic suction mechanism 21
7. By disposing the clamp mechanism 49 at a position where delivery is possible, the delivery operation can be performed.

Next, the printing operation will be described. First,
The printing paper 53 is supplied between the plate cylinder 1 and the transfer cylinder 5 from the paper feeding unit 15. The supplied printing paper 53 is held between the blanket 173 by a plurality of claws 195 of the printing paper holding means 151 at the leading end thereof. Then, the printing paper 53 passes between the plate cylinder 1 and the transfer cylinder 5, and at this time, the printing cylinder 53
The printing is performed by the printing unit 17 from the side, while the image once transferred from the plate cylinder 3 to the transfer cylinder 5 is printed on the back side of the printing paper 53. Then, the printing paper 53 on which printing has been performed is released from the holding of the printing paper holding means 151 at a predetermined timing, and is discharged via the paper discharging means 21. After printing is completed, the base paper 29 wound around the plate cylinders 1 and 3 is discharged by the plate discharge means 11 and 13, respectively, and the transfer cylinder 5 is cleaned by the cleaning means 22.

According to the present embodiment, the following effects can be obtained. First, for the printing paper 53,
Simultaneous printing on the front surface and the back surface can be performed, and at this time, complicated work such as resetting the printing paper 53 is not performed as in the related art. Further, since the printing on the back side of the printing paper 53 is not performed directly from the plate cylinder 3 but via the transfer cylinder 5, the printing paper 53 is compared with the case where printing is performed directly from the plate cylinder 3. The amount of ink transferred to the back surface of the substrate can be made an appropriate amount. That is, since it is possible to prevent excess ink from adhering to the back surface of the printing paper 53, it is possible to prevent the printing paper 53 from being stained after printing, that is, to stain the surface of the printing paper 53 already printed. Can be effectively prevented and print quality can be improved. Further, at the time of printing, the printing paper 53 is held by the printing paper holding means 151 provided on the transfer cylinder 5, so that the printing paper 53 after printing is surely transferred to the transfer cylinder 5 side. It will be transported and ejected while being held,
It is possible to eliminate the problem that it is not clear to which side the printing paper 53 is stuck and discharged and the separation becomes unstable. That is, the timing of separating the printing paper 53 from the plate cylinder 1 side is constant, it is possible to prevent extra ink from adhering to the surface of the printing paper 53, and It will effectively prevent soiling. Also, when printing is performed directly from the plate cylinder 1 and when printing is performed via the transfer cylinder 5, the amount of transferred ink tends to be larger in the case of printing directly from the plate cylinder 1. In this regard, in this embodiment,
The printing paper 53 is configured to be held on the transfer cylinder 5 side,
Since the contact time between the transfer cylinder 5 and the printing paper 53 is ensured, the variation in the amount of ink transferred to the front and back of the printing paper 53 can be reduced at the same time.
Further, the print quality on the front side and the back side of the printing paper 53 can be made equal to reduce the variation. That is, by holding the printing paper 53 on the transfer cylinder 5 side to secure the contact time, the amount of ink transferred from the transfer cylinder 5 side to the printing paper 53 increases, and conversely, the contact time on the plate cylinder 1 side Is reduced stably, so that the amount of ink supplied from the plate cylinder 1 side is reduced, and variations are eliminated by both of them. Further, when the transfer cylinder 5 is used as in the present embodiment, since the print pattern is repeatedly transferred to the same position, the transfer efficiency to the printing paper 53 is high and the afterimage after printing is small and stable. For example, when the emulsion ink is used, the influence of the transfer due to the osmotic pressure of the water is large. Therefore, as described above, it is difficult to increase the contact time on the transfer cylinder 5 side. This is also effective in increasing the transfer efficiency of transferring a small amount of ink stably.

[0037]

The present invention is not limited to the first and second embodiments. First, as for the plate making means, the plate making for the front side and the back side may be performed by one plate making means as in each of the above-described embodiments. It may be performed. In that case, the delivery of the base paper for the back side becomes unnecessary. Further, in each of the above embodiments, the printing color is not particularly mentioned, but for example, a configuration in which two-color printing is performed at the same time can be considered.

[0039]

As described in detail above, according to the stencil printing apparatus of the present invention , the first squeegee
The ink image of the first plate cylinder onto the printing paper
The second squeegee upstream from the transfer position
And the ink image on the transfer cylinder transferred by the roller
Printing paper supply means at an upstream position where the printing paper comes into contact with the printing paper in advance
Supply the printing paper and maintain it by the printing paper holding means.
As a result, variations in the amounts of ink on the front surface and the back surface can be reduced at the same time, the use of the ink can be made equal, and the transfer of a small amount of ink stably can be performed. Efficiency can also be increased.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an embodiment of the present invention, and is a perspective view illustrating an appearance of a stencil printing apparatus.

FIG. 2 is a diagram illustrating an embodiment of the present invention, and is a side view schematically illustrating an internal configuration of a stencil printing apparatus.

FIG. 3 is a view showing one embodiment of the present invention, and is a side view showing an outline of an internal configuration of a stencil printing apparatus and a configuration of a rotation transmission mechanism for rotating a plate cylinder and a transfer cylinder.

FIG. 4 is a view showing an embodiment of the present invention, and is a side view mainly showing a configuration of a printing unit during non- printing when the inside of the plate cylinder is not printed.

FIG. 5 is a view showing an embodiment of the present invention, and is a cross-sectional view showing a configuration inside the plate cylinder and mainly showing a printing unit.

FIG. 6 is a view showing an embodiment of the present invention, and is a side view mainly showing a configuration of a printing unit at the time of printing, showing a configuration inside a plate cylinder.

FIG. 7 is a view showing one embodiment of the present invention, and is a side view showing a rotation operation of a lift cam of a printing unit.

FIG. 8 is a view showing one embodiment of the present invention, and is a cross-sectional view showing a part of an internal configuration of a transfer cylinder centering on a configuration of a printing paper holding unit.

FIG. 9 is a view showing one embodiment of the present invention, and is a side view showing a part of the internal configuration of the transfer cylinder centering on the configuration of the printing paper holding means.

FIG. 10 is a diagram illustrating an embodiment of the present invention, and is a side view illustrating a state in which a leading edge of a printing sheet is held by holding claws of a printing sheet holding unit.

FIG. 11 is a diagram showing a conventional example, schematically illustrating a main part of a stencil printing apparatus.
FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 plate cylinder (first plate cylinder) 3 plate cylinder (second plate cylinder) 5 transfer cylinder 7 original reading means 9 plate making means 11 plate discharging means 13 plate discharging means 15 paper feeding means 17, 19 printing means 21 paper discharging means 22 Cleaning means 151 Printing paper holding means

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takuhiro Shibayama 20-10 Nakayoshida, Shizuoka City, Shizuoka Prefecture Inside Star Precision Co., Ltd. (56) References JP-A-8-118774 (JP, A) JP-A Heisei 6-71999 (JP, A) JP-A-7-52517 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41L 13/04 B41L 13/18

Claims (1)

(57) [Claims] 1. A first plate on which a stencil sheet is wound.
A second plate cylinder on which a perforated stencil sheet is wound; a transfer cylinder onto which an ink image of the second plate cylinder is transferred; and
Pressing means for pressing the first plate cylinder through the transfer cylinder;
The first printing cylinder and the transfer cylinder sandwiching and pressing the printing paper.
By transporting them together, both sides of the printing paper
In a stencil printing machine that simultaneously prints on a surface,The outer peripheral surface of the first plate cylinder is located in the first plate cylinder,
Put the first plate cylinder in the projecting / pressing state with respect to the photo cylinder.
Transfer the print image to the printing paper positioned on the transfer cylinder.
A first squeegee roller, The outer peripheral surface of the second plate cylinder is located in the second plate cylinder.
With the projecting / pressing state against the photo cylinder,
A second squeegee roller for transferring an image to the transfer cylinder
When, On the transfer cylinder, by the first squeegee roller
The ink image of the first plate cylinder is transferred to the printing paper.
Upstream of the second squeegee roller,
The ink image on the transfer cylinder transferred by
Supply the printing paper to the upstream position where the paper comes into contact in advance
Printing paper supply means, The printing paper supply means allows the transfer cylinder to be used for printing.
Holds the leading edge of the printing paper during printing when paper is supplied.
The first plate cylinder projects from the upstream position toward the transfer cylinder.
To the downstream position via the
For printing, holding the printing paper on the transfer cylinder side
Paper holding means,  A stencil printing apparatus, comprising: