JP2003039802A - Equipment and method for stencil printing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate nonuniformity in an image density, an image density difference or the like which occurs between a printing image for the surface and a printing image for the rear, as the amount of transfer of ink transferred from the outer peripheral surface of a plate cylinder onto the outer peripheral surface of a transfer cylinder becomes smaller than that of the ink transferred directly from the outer peripheral surface of the plate cylinder onto printing paper, in stencil printing equipment of a one-pass double-side printing system using one plate cylinder and a divided transfer cylinder. SOLUTION: Based on output signals from a double-side printing set key 143 and a plate making start key 141 of an operation panel 140, a control device 90 selects, from a ROM 92, the relational data for forming a non-plate-making area length L25 corresponding to a pressing force changeover time required for changing a pressing force of the transfer cylinder 9 against the plate cylinder 1, between a plate making image area 24 for the rear and a plate making image area 23 for the surface along the direction A of rotation of the plate cylinder 1 in a master 22 already subjected to plate making. It controls a thermal head 26 through the intermediary of a thermal head driving circuit 26A and controls a master carrying motor 30 through the intermediary of a master carrying motor driving circuit 30A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stencil printing apparatus, and more particularly to a double-sided stencil printing apparatus capable of simultaneously printing on the front and back surfaces of a printing sheet with one-pass sheet feeding (one-time sheet feeding). ..

[0002]

2. Description of the Related Art At present, a printing method which is generally popular in the world is a copy printing method using a plate and ink, which is characterized in that a large amount of printed matter can be produced inexpensively, at high speed, and in a short time. And it can be obtained with high quality. The types of printing methods are classified into the following four types according to the edition format. (1) letterpress printing (2) intaglio printing (3) lithographic printing (4) stencil printing A stencil printing apparatus is known as one using the most popular printing method among them. Ordinary stencil printers
The print image is formed only on the front surface of the printing paper in one pass. The device configuration is such that an image of a document is optically read by a document reading device, and the optical information is converted into an electric signal by a photoelectric conversion element such as a CCD (charge coupled device), and mainly a thermoplastic resin film and a porous support are used. The stencil printing plate (hereinafter referred to as "master") composed of a body (base) is informed to a stencil making unit as a stencil making device for making holes corresponding to image information.

In the plate making unit, a thermal head having a plurality of minute heating elements, which are also called heating elements, arranged in the main scanning direction is pressed against a platen roller via a master, and the heating element of the thermal head is pulsed. The platen roller conveys the master in the sub-scanning direction orthogonal to the main scanning direction (hereinafter, sometimes referred to as the “master conveyance direction”) while energizing the plate to generate heat, thereby responding to the image information from the document reading device. The heat-sensitive punching is performed to form a punching pattern. In this way, the master after the plate making, in which the perforation pattern is formed according to the image information, is automatically conveyed through the cutter unit etc. by the rotation of the plate feed roller pair, etc., and the outer periphery of the plate cylinder also called the porous cylindrical printing drum. The master is automatically wound around the surface, and the leading end of the master is held and fixed by a clamper that can be opened and closed for each plate, and is wound around the outer peripheral surface of the plate cylinder.

Around the outer periphery of the plate cylinder, a large number of metal supporting cylinders having fine holes are formed, and a single or plural layers of mesh screens are wound on the supporting cylinder. In addition, an ink supply member called an ink supply roller that supplies ink to the inner peripheral surface of the plate cylinder is arranged inside the plate cylinder, and next to it is an ink amount regulation that adjusts the ink supply amount called a doctor roller. The member is arranged. A cylindrical impression cylinder (pressing means), at least the surface of which is made of a material such as synthetic rubber, is arranged at a position facing the plate cylinder so as to be able to come into contact with and separate from the outer peripheral surface of the plate cylinder. At the time of printing, a printing sheet as a sheet-shaped recording medium is fed from a sheet feeding unit as a sheet feeding device between the plate cylinder and the impression cylinder, and the impression cylinder is displaced / raised toward the ink supply roller to move to the plate cylinder. By pressing the printing paper against the outer peripheral surface of the ink, the ink pushed out by the ink supply roller passes through the perforation pattern of the master that has been prepressed, the ink image is transferred to the printing paper, and the printing paper thus printed is ejected. Is discharged to the paper discharge unit. It should be noted that the master, which has been made into a plate and is wound around the plate cylinder, can be used repeatedly as many times as long as the master does not perform a reading operation or a plate making operation. As the pressing means, a press roller may be used instead of the impression cylinder.

If a new original is to be read, the used master, which has been wound around the plate cylinder until now, is peeled off by a peeling conveying member such as a plate discharging peeling roller and stored in the plate discharging box. In the current stencil printing apparatus, the speed at which the first printed material is discharged, that is, the so-called FPT (first print time), is shortened by simultaneously performing the plate discharging operation and the plate making operation described above in parallel.

However, recently, there is an increasing need for a double-sided printing apparatus capable of printing on the front surface and the back surface of the printing paper, instead of the single-sided printing apparatus capable of printing only on the front surface of the printing paper as described above. . As the double-sided printing method, for example, a one-plate cylinder temporary stock re-feeding method as disclosed in Japanese Patent Application Laid-Open No. 7-81202, or a two-sided printing method as disclosed in Japanese Patent Application Laid-Open No. 10-86498, for example.
Plate cylinder facing type 1-pass double-sided printing method, for example, Japanese Patent Laid-Open No. 8-1
No. 18774, Japanese Unexamined Patent Publication No. 11-20291, Japanese Unexamined Patent Publication No. 11-58913, or the like, a two-plate cylinder facing one-transfer cylinder interposing type one-pass double-sided printing method, or, for example, Japanese Unexamined Patent Publication No. 10-129100. There is a 1-plate cylinder split transfer cylinder 1-pass double-sided printing system as disclosed in the publication.

The 1-plate cylinder temporary stock re-feeding system uses a mechanism and a device substantially similar to the above-mentioned single-sided printing device.
It is configured such that it can be moved together with the paper discharge unit including the paper discharge tray, and once the functional structure of the paper feed tray is added to the paper discharge tray or a reversal paper feed path is newly added, This is a double-sided printing method in which the printing paper on the discharge tray, which has been printed on the front surface, is conveyed through the reverse paper feed path and is printed again on the back surface.

In the two-plate cylinder facing type one-pass double-sided printing method, a plate cylinder is used instead of the impression cylinder and the press roller of the above-mentioned one-sided printing device, and two printing cylinders having the same diameter are opposed to each other to sandwich the printing paper. This is a 1-pass double-sided printing method in which printing is performed simultaneously on the front and back surfaces of printing paper.

The two-plate cylinder facing one-transfer cylinder interposing type one-pass double-sided printing system includes first and second plate cylinders which are provided with ink supply means and are rotatable around by winding a master around the outer peripheral surface thereof. , Second
By transferring the ink image from the second plate cylinder to the transfer cylinder and then retransferring the ink image on the transfer cylinder to the back surface of the same printing paper. This is a one-pass double-sided printing method in which printing is performed on the front and back surfaces of printing paper at the same time.

However, although the 1-plate cylinder temporary stock re-feeding method has the advantage that it can be used with a slight modification of the conventional printing apparatus and its configuration, the movement time required to move the paper discharge unit is reduced. If there is a problem or if the surface-printed paper is not sufficiently dried, the surface-printed image will be transferred to the outer surface of the impression cylinder or press roller during backside printing, causing the impression cylinder or press roller to print the ink. There is also a problem in that the ink on the impression cylinder and the press roller is transferred to the surface printed image of the next printed matter by being stained with the ink.

On the other hand, in the two-pass cylinder opposite-type one-pass double-sided printing system, there are problems in moving time such as in the one-plate cylinder temporary stocking and re-feeding system, and problems such as transfer of ink to the impression cylinder and the press roller. In addition to this, there is an advantage that double-sided printing can be performed in a short time with one pass. However, there are problems such as an increase in a new plate making unit and a plate discharge unit due to the provision of the plate cylinder instead of the impression cylinder, and an improvement in the ink supply method inside the plate cylinder by disposing the plate cylinder below. At the same time, it causes an increase in the number of parts and an increase in the size of the device.

Further, in the two-plate cylinder facing one-transfer cylinder interposing type one-pass double-sided printing system, the same problem of moving time as in the two-plate cylinder facing one-pass double-sided printing system and the transfer of ink to the impression cylinder and the press roller. In addition to the above problems, there is an advantage that double-sided printing can be performed in a short time with one pass. However, for example, JP-A-8-118774 and JP-A-11-
According to the technique disclosed in Japanese Patent No. 20291, an increase in a new plate-making unit and a plate-discharging unit, and a second plate-cylinder inside by arranging the second plate-cylinder substantially in the same manner as in the 2-plate-cylinder facing-type one-pass double-sided printing method. In addition to problems such as improvement of the ink supply method, the number of parts and the size of the apparatus increase. The technique disclosed in Japanese Patent Application Laid-Open No. 11-58913 solves the problem of the increase in new plate making units and plate discharge units.

Therefore, in the present invention, the 1-plate cylinder division transfer cylinder 1
The double-sided pass printing method is recommended. This 1 plate cylinder transfer cylinder 1
The basic configuration of the stencil printing machine adopting the pass double-sided printing method is that a plate cylinder having a front surface printing area and a back surface printing area on one plate cylinder outer peripheral surface and a back surface printing area of the plate cylinder are passed. It is provided with a transfer cylinder on which a back side ink image transferred by ink is formed, and a conveying means for conveying the printing paper between the plate cylinder and the transfer cylinder on which the back side ink image is formed. .

According to such a 1-plate cylinder split transfer cylinder 1-pass double-sided printing method, the printing paper passes between the plate cylinder and the transfer cylinder on which the ink image for the back side is formed, so that the printing paper is transferred in one pass. It is possible to print on the front and back sides at the same time. That is, in the 1-pass double-sided printing method, 1
Since only one plate cylinder, one transfer cylinder, and one plate making unit and one plate discharge unit, respectively, are provided, the cost reduction due to the reduction in the number of parts and the size reduction of the apparatus can be achieved. Further, since one master (stencil sheet) has a front side plate making image and a back side plate making image, it is possible to use one clamper for holding and fixing the leading end portion of the master on the outer surface of the plate cylinder. . Further, in the above printing machine, since the diameter ratio of the plate cylinder and the transfer cylinder can be set to 2: 1, the plate cylinder and the transfer cylinder are continuously rotated at a constant rotation speed (constant rotation speed). It also has various effects such as being able to perform printing selectively.

[0015]

In the above-described 1-plate cylinder split transfer cylinder 1-pass double-sided printing method, when printing is performed using the plate-making image for the surface, the ink that has passed through the plate-cylinder and the plate-making image for the surface is directly printed. When transferred to paper and printed using the backside plate-making image, the ink that has passed through the plate cylinder and the backside plate-making image is once transferred and transferred to the transfer cylinder to form an ink image, and then the ink image is further transferred. The method of transferring directly from the transfer cylinder to the back side of the printing paper is adopted.

In general, the amount of ink transferred from the plate cylinder to the transfer cylinder via the master that has been prepressed is largely dependent on the surface smoothness of the transfer cylinder. In addition, the outer peripheral surface layer of the transfer cylinder is improved in cleaning performance after transfer, as disclosed in, for example, Japanese Patent Application Laid-Open No. 8-142302, in order to obtain a printed material with less set-off, bleeding, strike-through, etc. In addition, ink-repellent silicone rubber (Q), which is ink-repellent, and resin tetrafluoroethylene (PTF)
A material having high smoothness such as E) is used. in this way,
Due to the difference in contact area with the surface of the transfer cylinder, the transfer amount of ink is small when the smoothness of the transfer cylinder is high, and the transfer amount of ink is large when the smoothness is low.

However, the above-mentioned Japanese Unexamined Patent Publication No. 10-1291.
In the technology described in Japanese Patent Publication No. 00 (the above-mentioned 1-plate cylinder split transfer cylinder 1-pass double-sided printing method), although the basic principle and configuration as described above are disclosed, the 1-plate cylinder split transfer cylinder 1
Consideration on the device structure necessary for practical use of the pass double-sided printing method, that is, the pressing force of the transfer cylinder against the plate cylinder during double-sided printing and transfer, the rotation speed of the plate cylinder, or the plate making on the plate cylinder. No consideration is given to the perforation diameter and the like of the front side plate making image area and the back side plate making image area in the completed master. Therefore, a known technique of using the above-mentioned material having ink repellency for the outer peripheral surface layer of the transfer drum is described in the technique described in JP-A-10-129100 (the above-mentioned 1-version cylinder divided transfer drum 1-pass double-sided). Print method). As a premise of its application, the above-mentioned Japanese Patent Laid-Open No.
In the technique described in Japanese Patent Application Laid-Open No. 129100, the pressing force of the transfer cylinder against the plate cylinder during double-sided printing and transfer, the rotation speed of the plate cylinder, or the plate-making image area for the front surface and the back surface of the plate-made master on the plate cylinder. Since no consideration is given to the perforation diameter of the plate-making image area, the pressing force of the transfer cylinder against the plate cylinder and the rotation speed of the plate cylinder during double-sided printing and transfer are the same. The side corresponds to the front side printing area corresponding to the front side plate making image area of the plate making master on which the front side plate making image is formed and the back side plate making image area of the plate making master to which the back side plate making image is formed. It has the same structure regardless of the printing area for the back side, the plate making conditions are the same, and the same ink (usually, for example, water-in-oil type (W / O type) emulsion ink) is used. It is considered that the ease with which ink is ejected from the outer peripheral surface of the plate cylinder is the same in both the front surface printing area and the back surface printing area.

As described above, the ease with which ink is ejected from the outer peripheral surface of the plate cylinder is the same in both the front surface printing area and the back surface printing area, and an ink-repellent material is applied to the outer peripheral surface layer of the transfer cylinder. Ink that is used and transferred from the outer peripheral surface of the plate cylinder to the outer peripheral surface of the transfer cylinder when compared with the case of simultaneously printing on the front and back sides based on the same plate-making image of the same original, for example. The transfer amount is smaller than the ink transfer amount transferred directly from the outer peripheral surface of the plate cylinder to the printing paper. As a result, the print image density unevenness or the print image density difference occurs between the front surface print image and the back surface print image. Hereinafter, the print image density is simply referred to as “image density”.

Therefore, the present invention has been made in view of the above circumstances, and in the above-described 1-plate cylinder split transfer cylinder 1-pass double-sided printing system, not only can the known effects be obtained, but also in a plate-made master. Between the front side plate making image area and the back side plate making image area along the rotation direction of the plate cylinder,
A master is set according to the pressing force switching time required to change the pressing force of the transfer cylinder with respect to the plate cylinder, the rotation speed switching time required to change the rotation speed of the plate cylinder, and the front plate making image area and the back plate making image area. By forming a plateless region of a predetermined length corresponding to at least one switching time of the energy switching time for punching required to change the energy for punching for punching, a front-side print image and a back-side print image are formed. A first object of the present invention is to provide a stencil printing apparatus and a stencil printing method capable of preventing image density unevenness and the like that occur between the two.
The purpose of.

A second object is to make the transfer cylinder pressing force against the plate cylinder during transfer of the back side plate-making image different from the printing cylinder pressing force against the plate cylinder during double-sided printing. It is to reduce the image density difference that occurs between the front side print image and the back side print image. Third
The purpose of is to correspond the pressure during transfer of the transfer cylinder to the plate cylinder during the transfer of the backside plate-making image and the pressure during printing of the transfer cylinder against the plate cylinder during double-sided printing to the plate-less area of the master that has already made the plate. The first object is easily achieved by changing the rotational position of the plate cylinder.

A fourth object is to make the rotational speed of the plate cylinder during transfer of the plate-making image for the back side different from the rotational speed during printing of the plate cylinder for double-sided printing so that the printed image for the front surface and the backside image can be different from each other. This is to reduce the difference in image density that occurs between the print image for printing. A fifth object is to control the rotational speed during transfer of the plate cylinder during transfer of the plate-making image for the back surface and the rotational speed during printing of the plate cylinder during double-sided printing of the plate cylinder corresponding to the plate-less region of the master that has already made the plate. The first purpose can be easily achieved by changing the rotational position.

A sixth object is that the energy for perforation to be supplied to each heating element of the thermal head (plate-making means) has been plate-prepared in accordance with the formation of the plate-making image for the front surface and the formation of the plate-making image for the back surface. It is to reduce the image density difference that occurs between the front-side print image and the back-side print image by changing the master plate in accordance with the masterless plate making area. A seventh object is that the aperture ratio of the mesh screen corresponding to the back side plate making image area in the plate making master wound on the mesh screen of the plate cylinder corresponds to the front side plate making image area of the plate making master. The print image for the front side and the print image for the back side are set by setting it larger than that, and by configuring the switching position of the aperture ratio so as to correspond to the plate-less area of the plate-making master that is wound on the mesh screen. To reduce the difference in image density that occurs between and.

An eighth object is to obtain the known effects in the 1-plate cylinder split transfer cylinder 1-pass double-sided printing system as well as to obtain the rotational speed of the plate cylinder during transfer of the backside plate-making image, An object of the present invention is to provide a stencil printing apparatus capable of reducing an image density difference generated between a front-side print image and a back-side print image by having a configuration that changes a printing cylinder rotation speed during double-sided printing. .

[0024]

In order to solve the above-mentioned problems and to achieve the above-mentioned object, the present invention adopts the following means / invention specifying matters (structures) in the invention for each claim. It is characterized by that. The invention according to claim 1 is a plate making apparatus for punching a master to form a front plate making image and a back plate making image according to image information, and a front plate making image on which the front plate making image is formed. A plate cylinder for winding a plate-making master having a region and the back plate-making image region on which the back plate-making image is formed, and the plate cylinder from the inside of the plate cylinder so as to be contactable so as to face the plate cylinder. By the ink that has passed through the plate making image for the back side,
A transfer cylinder having an ink image for the back surface formed on the surface thereof, and feeding the print paper between the plate cylinder and the transfer cylinder having the ink image for the back surface formed thereon, In a stencil printing apparatus capable of simultaneously printing on both sides of the, the plate making apparatus, between the front side plate making image area and the back side plate making image area along the rotation direction of the plate cylinder in the plate making master. The pressing force switching time required to change the pressing force of the transfer cylinder with respect to the plate cylinder, the rotation speed switching time required to change the rotation speed of the plate cylinder, the plate-making image area for the front surface and the plate-making image for the back surface. Forming a plateless area of a predetermined length corresponding to at least one switching time of the energy switching time for punching required to change the energy for punching to punch the master according to the area It is characterized in.

Here, "the pressing force switching time required to change the pressing force of the transfer cylinder with respect to the plate cylinder, the rotation speed switching time required to change the rotation speed of the plate cylinder, and the surface plate-making image area The following seven modes are included in the "at least one switching time of the perforation energy switching time required for changing the perforation energy for perforating the master according to the back side plate-making image area". The first is only the pressing force switching time, and the second is
Is a mode of only the rotation speed switching time, a third is a mode of only the perforation energy switching time, a fourth is a mode of the pressing force switching time and the rotation speed switching time, and a fifth is a mode. A sixth aspect is a mode of the pressing force switching time and the perforation energy switching time, a sixth is a mode of the rotational speed switching time and the perforation energy switching time, and a seventh aspect.
Is a mode including all of the pressing force switching time, the rotation speed switching time, and the perforation energy switching time.

According to a second aspect of the present invention, in the stencil printing apparatus according to the first aspect, the transfer pressing force of the transfer cylinder against the plate cylinder at the time of transferring the backside plate-making image, and the plate at the time of double-sided printing. It is characterized in that it has a pressing force varying means for changing the pressing force of the transfer cylinder at the time of printing with respect to the cylinder.

According to a third aspect of the present invention, in the stencil printing apparatus according to the second aspect, the transfer pressing is performed at a rotational position of the plate cylinder corresponding to the plateless area of the master on the plate cylinder. It is characterized in that the pressure is switched to the pressing force during printing.

According to a fourth aspect of the present invention, in the stencil printing apparatus according to the first aspect, the rotational speed of the plate cylinder during transfer of the backside plate-making image and the printing speed of the plate cylinder during double-sided printing. It is characterized by having a rotation speed varying means for changing the rotation speed.

According to a fifth aspect of the present invention, in the stencil printing apparatus according to the fourth aspect, the plate cylinder is rotated at the rotational position corresponding to the plateless region of the master on the plate cylinder. It is characterized in that the speed is switched to the rotation speed during printing.

The invention according to claim 6 is the same as claims 1 to 5.
In the stencil printing apparatus according to any one of 1, a plate-making device having a plurality of heating elements in the main scanning direction for punching a master, and at the time of forming the plate-making image for the front surface and forming the plate-making image for the back surface. Depending on the time, it has a perforation energy variable means for changing the perforation energy supplied to the individual heating elements of the plate making means, and switching of the perforation energy by the perforation energy variable means is the plateless plate It is characterized in that it corresponds to a region.

The invention according to claim 7 is the invention according to claims 1 to 6.
In the stencil printing apparatus according to any one of, a start setting means for starting the plate making apparatus, a storage means for pre-storing data relating to a predetermined length of the plate making area, and the start setting means It is characterized by further comprising control means for selecting data relating to a predetermined length of the plate-making area from the storage means on the basis of a signal and controlling the plate making apparatus so as to form the plate-making area.

The invention according to claim 8 is the invention according to claims 1 to 7.
In the stencil printing apparatus according to any one of the above, the outer peripheral surface of the plate cylinder is wound with an ink-permeable mesh screen, and the master in a plate-making master wound on the mesh screen The aperture ratio of the mesh screen corresponding to the back side plate making image area is set larger than that corresponding to the front side plate making image area, and the switching position of the aperture ratio is wound on the mesh screen. It is characterized in that it corresponds to the above-mentioned plate-less area of the master which has been plate-formed.

According to a ninth aspect of the present invention, a master having a plate-making process, which has a front-side plate-making image region on which a front-side plate-making image is formed and a back-side plate-making image region on which a back-side plate-making image is formed, is provided on the plate cylinder. By the master winding step of winding and the transfer cylinder provided so as to be able to contact the plate cylinder, the ink for the back surface is transferred to the surface of the transfer cylinder by the ink that has passed through the plate-making image for the back surface from the inside of the plate cylinder. A transfer process formed on the top,
A stencil printing method including a double-sided printing step of simultaneously printing on both sides of a printing paper by feeding a printing paper between the plate cylinder and the transfer cylinder on which the ink image for the back side is formed. Between the front side plate making image area and the back side plate making image area along the rotation direction of the plate cylinder in the completed master, the pressing force switching time required to change the pressing force of the transfer cylinder to the plate cylinder , For perforation required to vary the rotational speed switching time required to change the rotational speed of the plate cylinder and perforation energy for perforating the master according to the front side plate making image area and the back side plate making image area It is characterized in that a plate-making master in which a plate-making region having a predetermined length corresponding to at least one of the energy switching times is formed is used.

According to a tenth aspect of the present invention, there is provided a plate cylinder for winding a plate-made master on which a surface plate-making image and a back plate-making image are formed, and a plate cylinder facing the plate cylinder so as to be in contact therewith. A transfer cylinder on which an ink image for the back side is formed on the surface by the ink which has passed through the plate-making image for the back side from the inside of the plate cylinder, and the transfer in which the ink image for the back side is formed. In the stencil printing apparatus capable of simultaneously printing on both sides of the printing paper by feeding the printing paper between the cylinder and the cylinder, the transfer rotation speed of the plate cylinder at the time of transferring the backside plate-making image and It is characterized in that it has a rotation speed varying means for changing the rotation speed of the plate cylinder during printing during double-sided printing.

The present invention includes the following technical configurations, and the technical configurations have the following unique effects. A first technical configuration is a plate cylinder around which a plate-making master is wound, the plate cylinder having a front plate-making image area on which a front plate-making image is formed and a back-side plate making image area on which a back-side plate making image is formed, And a transfer cylinder provided so as to face the plate cylinder so as to be in contact therewith, and an ink image for the back surface is formed on the surface of the plate by the ink that has passed through the plate-making image for the back surface from the inside of the plate cylinder. In the stencil printing machine capable of simultaneously printing on both sides of the printing paper by feeding the printing paper between the transfer cylinder on which the back side ink image is formed and the transfer cylinder on which the back side plate image is formed. The present invention is characterized by comprising pressing force varying means for changing the pressing force of the transfer cylinder with respect to the plate cylinder at the time of transfer and the pressing force of the transfer cylinder with respect to the plate cylinder at the time of double-sided printing. .
According to the first technical configuration, since one plate cylinder and one transfer cylinder are provided, and one plate making device and one plate discharging device can be arranged, one master plate is used. Since it is possible to print on both sides of the printing paper at the same time, the cost can be reduced by reducing the number of parts and the size of the device can be reduced (hereinafter referred to as "the effect of the 1-version cylinder split transfer cylinder 1-pass double-sided printing method"). In addition, the pressing force varying means changes the pressing force at the time of transfer and the pressing force at the time of printing, so that the amount of ink passing from the plate making image for the front surface to the surface of the printing paper and the amount of ink passing at the time of transferring the plate making image for the back surface By adjusting the and, it is possible to equalize the ink passage amount when re-transferring from the ink image for the back side on the transfer cylinder to the back side of the printing paper and the ink passage amount from the plate-making image for the surface to the front side of the printing paper. Na Because be adjusted becomes possible as possible to reduce the image density difference is generated between the surface for printing images and backside print image.

A second technical configuration is a plate cylinder for winding a master having a plate-making completed, which has a front plate-making image area on which a front plate-making image is formed and a back-side plate making image area on which a back-side plate-making image is formed. And a transfer cylinder provided so as to face the plate cylinder so as to be contactable therewith, and an ink image for the back surface is formed on the surface by the ink that has passed through the plate-making image for the back surface from the inside of the plate cylinder, A master is punched in a stencil printing apparatus capable of simultaneously printing on both sides of a printing paper by feeding the printing paper between the plate cylinder and the transfer cylinder on which the back side ink image is formed. The plate-making means having a plurality of heating elements in the main scanning direction for supplying, to the individual heating elements of the plate-making means according to the formation of the front side plate-making image and the formation of the back side plate-making image Change the drilling energy It is characterized in that it has a hole for energy varying means. According to the second technical configuration, in addition to the effect of the 1-plate cylinder divided transfer cylinder 1-pass double-sided printing system, the energy changing means for perforation is used to form a plate-making image for the front surface and a plate-making image for the back surface. By adjusting the perforation energy supplied to each heating element of the plate making means, the ink passing amount from the front plate making image to the front surface of the printing paper and the ink passing amount at the time of transferring the back plate making image are adjusted. As a result, the amount of ink passing from the ink image for the back side on the transfer cylinder to the back side of the printing paper at the time of re-transfer and the amount of ink passing from the plate-making image for the front side to the surface of the printing paper become equal. Since the adjustment can be performed, it is possible to reduce the image density difference that occurs between the front side print image and the back side print image.

A third technical configuration is a plate cylinder for winding a master that has been prepressed and has a front side plate-making image area on which a front side plate-making image is formed and a back side plate-making image area on which a backside plate-making image is formed. And a transfer cylinder provided so as to face the plate cylinder so as to be contactable with the ink having passed through the back plate-making image from the inside of the plate cylinder, and a back ink image is formed on the surface thereof, In a stencil printing machine capable of simultaneously printing on both sides of a printing paper by feeding a printing paper between the printing cylinder and the transfer cylinder on which the ink image for the back side is formed, It has a heating means for heating the surface of the. According to the third technical configuration, in addition to the effect of the 1-plate cylinder split transfer cylinder 1-pass double-sided printing system, the surface of the transfer cylinder is heated by the heating means to transfer the back plate-making image to the surface of the transfer cylinder. By changing the ink viscosity so that the ink viscosity at the time decreases relatively, it becomes possible to adjust the ink passage amount from the front plate making image to the front surface of the printing paper and the ink passage amount at the time of transferring the back plate making image. Therefore, it is necessary to adjust so that the amount of ink passing from the back side ink image on the transfer cylinder to the back side of the printing paper is equal to the amount of ink passing from the front side plate making image to the front side of the printing paper. Therefore, it is possible to reduce the difference in image density that occurs between the front-side print image and the back-side print image.

According to a fourth technical constitution, in the stencil printing machine described in the first technical constitution, a plate-making means having a plurality of heating elements for punching a master in the main scanning direction, and formation of the surface plate-making image. It has a perforation energy varying means for changing the perforation energy supplied to each heating element of the above-mentioned plate-making means according to the time and the time of forming the above-mentioned back-side plate-making image. According to the fourth technical configuration,
In two stages of the pressing force varying means and the perforation energy varying means, it becomes possible to share and adjust the amount of change between the pressing force at the time of transfer and the pressing force at the time of printing by the pressing force varying device and the amount of change in the energy for perforation. The effects of the first and second technical configurations are more prominently exhibited.

A fifth technical structure is characterized in that the stencil printing machine according to the first technical structure has a heating means for heating the surface of the transfer cylinder. According to the fifth technical configuration, the amount of change between the pressing force at the time of transfer and the pressing force at the time of printing by the pressing force varying unit and the degree of decrease in ink viscosity are shared in two stages of the pressing force varying unit and the heating unit. It becomes possible to adjust, and the effects described in the first and third technical configurations are exhibited in a more prominent form.

A sixth technical configuration is the stencil printing machine according to the second technical configuration, characterized by comprising heating means for heating the surface of the transfer cylinder. According to the sixth technical configuration, it is possible to share and adjust the amount of change in the energy for punching and the degree of decrease in the viscosity of the ink in two stages of the energy varying means for punching and the heating means. The effect described in the technical configuration of item 3 is exhibited in a more prominent form.

A seventh technical configuration is, in the stencil printing apparatus described in the first technical configuration, a plate-making means having a plurality of heating elements for punching a master in the main scanning direction, and formation of the surface plate-making image. Depending on the time and the time of forming the back side plate making image, an energy changing means for punching that changes the energy for punching to be supplied to each heating element of the plate making means, and a heating means for heating the surface of the transfer cylinder. It is characterized by having. According to the seventh technical configuration, the amount of change between the pressing force at the time of transfer and the pressing force at the time of printing by the pressing force varying unit and the energy for punching are three stages of the pressing force varying unit, the perforating energy varying unit, and the heating unit. The amount of change and the degree of decrease in the viscosity of the ink can be shared and adjusted, and the effects described in the first to third technical configurations can be more prominently exhibited.

An eighth technical structure is the stencil printing machine according to any one of the first to seventh technical structures, wherein an ink-permeable mesh screen is wound around the outer peripheral surface of the plate cylinder. The aperture ratio of the mesh screen corresponding to the back side plate making image area in the plate making master wound on the mesh screen is set larger than that corresponding to the front side plate making image area. It is characterized by being present. According to the eighth technical configuration, the aperture ratio of the mesh screen corresponding to the back side plate making image area in the plate making master wound on the mesh screen is set to be larger than that corresponding to the front side plate making image area. By doing so, it becomes possible to more easily adjust the ink passage amount from the front side plate making image to the front side of the printing paper and the ink passage amount at the time of transferring the back side plate making image. Since it is possible to adjust the ink passage amount at the time of retransfer from the ink image for printing to the back surface of the printing paper and the ink passage amount from the surface plate-making image to the front surface of the printing paper,
The effect described in any one of the seventh to seventh technical configurations is exhibited in a more remarkable form.

According to a ninth technical constitution, in the stencil printing apparatus according to any one of the first to eighth technical constitutions, the outer peripheral surface of the transfer cylinder is made of an ink repellent material. It is a feature. According to the ninth technical configuration, in addition to the effect described in any one of the first to eighth technical configurations, it is possible to obtain a printed material with less set-off, bleeding, strike-through, and the like. The cleaning performance after retransfer of the ink image to the back surface of the printing paper can also be improved.

A tenth technical configuration is the stencil printing machine according to any one of the first to ninth technical configurations, in which the back side ink image remaining on the transfer cylinder after double-sided printing is finished is cleaned. And a cleaning means for cleaning the ink on the outer peripheral surface of the transfer cylinder, the cleaning means being disposed on the upstream side in the rotational direction of the transfer cylinder, and the arrangement of the ink scraping means. And a cloth sheet cleaning means for cleaning the ink on the outer peripheral surface of the transfer cylinder after being scraped by the ink scraping means, the cloth sheet cleaning means being disposed on the downstream side in the rotational direction of the transfer cylinder. It is a feature. According to the tenth technical configuration, in addition to the effect described in any one of the first to ninth technical configurations, in comparison with the case where a cleaning liquid is used, for example, the cleaning unit becomes large and complicated. It is possible to prevent deterioration of image quality such as generation of a bleeding image when a cleaning liquid is used.

The eleventh technical configuration is any one of claims 1 to 8 and 10, the stencil printing apparatus according to any one of the first to tenth technical configurations, or the stencil printing according to claim 9. In the method, the diameter ratio between the plate cylinder and the transfer cylinder is 2: 1. 11th
According to the technical configuration of claim 1, the effect of the stencil printing device according to any one of claims 1 to 8 and 10, the stencil printing method according to any one of the first to tenth technical configurations, or the stencil printing method according to claim 9. In addition, the plate cylinder and the transfer cylinder can be continuously rotated at a constant speed.

According to any one of claims 1 to 8 and 10, the stencil printing apparatus according to any one of the first to eleventh technical constructions is provided so as to be "contactable so as to face the plate cylinder ... The "cylinder" and the "transfer cylinder provided so as to be able to contact the plate cylinder" in the stencil printing method according to claim 9 mean that the plate cylinder is pressed against the transfer cylinder via a master that has been prepressed and the back surface to the transfer cylinder Plate cylinder contact / separation method that transfers ink images for printing and double-sided printing operation, and presses the transfer cylinder against the plate cylinder via a master that has already been prepressed to transfer the back-side ink image to the transfer cylinder and double-sided printing operation. There are a transfer cylinder contact / separation method to be performed and a combination method thereof. Here, as the plate cylinder, as in the embodiment described later, a plate cylinder "having at least a supporting cylindrical body as an ink-permeable metal thin plate layer" can be mentioned, as well as an "ink-permeable mesh". A porous cylindrical body formed of a material that can be brought into contact with and separated from the outer peripheral surface of the transfer cylinder, and contact the inner peripheral surface of the porous cylindrical body arranged in the plate cylinder along one generatrix, to the transfer cylinder. It has an intermediate pressing roller that pushes the porous cylindrical body radially outward toward the transfer cylinder to press the outer peripheral surface of the transfer cylinder during the transfer of the ink image for the back surface and the double-sided printing. " To be

In the plate cylinder contacting / separating method, printing is performed by moving the porous cylinder portion of the plate cylinder to the transfer cylinder side (including a type in which the ink supply roller inside the plate cylinder projects to the transfer cylinder side). There is a well-known one. As an example of this, for example, Japanese Patent Laid-Open No. 1-20
No. 4781, Japanese Patent Application Laid-Open No. 3- 197078, Japanese Patent Application Laid-Open No. 3-259484, and the like, a so-called middle press roller system (which also serves as an ink supply roller) in which a metal screen is bulged from the inside to the outside (Including things). An example of the transfer cylinder contact / separation method is according to the embodiment described later.

[0048]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention (hereinafter, referred to as "embodiments") including examples will be described below with reference to the drawings. Throughout the embodiments and the like, constituent elements such as members and constituent parts having the same function and shape are designated by the same reference numerals, and the description thereof will be omitted once described. In order to simplify the drawings and the description, even if the constituent elements are to be shown in the drawing, the constituent elements that do not need to be particularly described in the drawing may be appropriately omitted without notice. When the reference numerals shown in the drawings and the like of the prior art disclosed patent publications and the like are quoted as they are, the quoted numerals shall be shown in parentheses. (Embodiment 1) FIG. 1 is a somewhat schematic diagram of the overall configuration of a stencil printing apparatus 200 to which an embodiment of the first invention of the stencil printing apparatus according to the present invention (hereinafter referred to as "Embodiment 1") is applied. Shown in. In FIG. 1, reference numeral 210 is a stencil printing apparatus 2
A main body frame forming a frame of 00 is shown.

As shown in FIG. 1, the stencil printing device 200 is arranged above the main body frame 210 and reads the image of the document 74 shown by the solid line and the chain double-dashed line.
And a body frame 210 below the document reading device 70.
Has a function and a configuration of a plate making apparatus for punching a master 22 which is arranged on one side part of the master 22 and is fed to form a front side plate making image and a back side plate making image according to image information. The plate-making plate feeding unit 20 having a part of the function and configuration of the plate-feeding device for feeding the completed master 22 to the clamper 4 of the plate cylinder 1, and the plate-making image for surface (disposed at the substantially central portion of the main body frame 210). A plate-making image area 23 on which a front plate-making image area 23 (not shown), a back-side plate-making image area 24 on which a back-side plate-making image (not shown) is formed, and a plate-making area 25 to be described later in detail. An ink image for the back side is formed by the plate cylinder 1 on which the master 22 is wound around the outer peripheral surface and the ink passed through the plate-making image 24 for the back surface from the inside of the plate cylinder 1 so as to face the plate cylinder 1 so as to be in contact therewith. Transfer cylinder 9 formed on top and plate making plate A sheet feeding unit 40 arranged below the knit 20 and feeding a printing sheet P as a sheet-shaped recording medium stacked on a sheet feeding tray 41 toward the sheet clamper 12 of the transfer cylinder 9 and a sheet feeding unit 40. As a paper discharging device which is arranged below the main body frame 210 facing the paper feeding unit 40, and which discharges the printed printing paper P, which is printed on both sides simultaneously by the plate cylinder 1 and the transfer cylinder 9, to the paper discharge tray 61. Is disposed between the sheet discharge unit 60 and the document reading device 70, and the used master 22 is stripped from the outer peripheral surface of the plate cylinder 1 and discharged into the plate discharge box 54 for storage. The plate discharge unit 50 as a plate discharge device, which is arranged between the plate making plate supply unit 20 and the paper feeding unit 40, and the operation of each of the above-described devices that constitute the stencil printing apparatus 200 will be described later. And a control unit 90 having a Gosuru function.

In FIG. 1, reference numeral 15 denotes a printing plate cylinder device for performing double-sided printing or single-sided printing by pressing the outer peripheral portion 9a of the transfer cylinder 9 against the master 22 on the plate cylinder 1 which has already been made.
The printing plate cylinder device 15 mainly includes a plate cylinder 1, a transfer cylinder 9, a contacting / separating means 120 shown in FIG. 5, and a pressing force varying means 130 shown in FIGS. 5 and 6. In FIG. 1, only a control device 90 corresponding to the first embodiment is illustrated for the sake of simplicity of the drawing, and a description of the control device corresponding to a modified example and other embodiments described later is given in a block diagram described below. Shall be done in.

The above-mentioned devices and units will be sequentially described below. The document reading device 70 includes a main body frame 21.
0, which is placed on the original receiving tray 72 and a contact glass 86 for reading the image by manually placing the original 74 indicated by the chain double-dashed line during manual reading. 8 sheets of original 74 contact glass 8
ADF to automatically transfer to a fixed position (reading position) on 6
An (automatic document feeder) 71 and a scanner 80 arranged below the contact glass 86 for reading an image of the document 74 placed at the above-mentioned predetermined position on the contact glass 86 or the image of the document 74 transferred from the ADF 71 are provided. ing.

The lower part of the ADF 71 is the main body frame 210.
Contact glass 8 with the upper left side as a fulcrum
A pressure plate that can be moved in and out of contact with 6 is openable and closable. The ADF 71 includes a document receiving tray 72, a document feeding roller 75 that sequentially feeds the document 74 placed on the document receiving tray 72 from the lowermost document 74, and one document 74 fed by the document feeding roller 75. Separation roller pairs 76a and 76b for separating and conveying each one, front conveyance roller pairs 77a and 77b for conveying the document 74 conveyed by the separation roller pairs 76a and 76b to the above-mentioned fixed position on the contact glass 86, and Conveying roller pair 77a, 77
The document 74 conveyed by the b is further conveyed in the document conveyance direction X1.
Rear transport roller pair 78 for transporting the document to the document discharge tray 79
a, 78b, and a first document size detection sensor 73 that is disposed between the front transport roller pair 77a, 77b and the rear transport roller pair 78a, 78b and that detects the document size of the document 74 in the document transport direction X1. To do.

The pair of rear carrying rollers 78a and 78b are connected to a document carrying motor (not shown) and are rotated by the document carrying motor. The front transport roller 77a is rotated via a timing belt (not shown) that is stretched between the rear transport roller 78a and the front transport roller 77a,
The rear conveyance roller 78b and the front conveyance roller 77b are driven to rotate. The first document size detection sensor 73 is a well-known reflective optical sensor including a light emitting element and a light receiving element. A plurality of transmissive optical sensors (not shown) for detecting the document width size of the document 74 in the document width direction are arranged on the document receiving tray 72. In addition, the original tray 72
Is provided with a guide plate (not shown) that is movable in the document width direction so as to position both end surface portions of the document 74. A sensor shielding member (both not shown) including a plurality of optical path shielding pieces for selectively shielding the optical path of the sensor is provided.

The scanner 80 has a contact glass 86.
And the original 7 placed on the contact glass 86, which is arranged on the lower left side in the figure of the contact glass 86.
No. 4 second document size detection sensor 87 for detecting the document size in the document transport direction X1, scanning mirror 82 for reflecting and reflecting the reflected light from the surface of document 74, and movement at a speed half that of scanning mirror 82. Optical path folding mirror pair 83a, 83b, and an imaging lens 8 having a variable magnification function
4 and an image sensor 85 including a CCD (charge imaging device)
And a light source 81 composed of an illumination lamp (fluorescent lamp or the like) that moves together with the scanning mirror 82 and illuminates the surface of the document 74.
And a known original scanning optical system including The image sensor 85 performs photoelectric conversion in response to the reflected light imaged via the imaging lens 84, and the image signal obtained by this is converted into analog / digital (hereinafter referred to as “analog / digital” shown in FIG. The data is input from a conversion device 88 (abbreviated as “A / D”) through an image processing device 89 to a plate making control device (not shown) in a control device 90. The second document size detection sensor 87 includes a reflective optical sensor,
The original 74 is set at each standard size position.

The control target drive parts such as the document feed motor in the ADF 71 are collectively referred to as an ADF drive part 71A in the block diagram of FIG. In FIG. 9, the scanner drive unit 80A is a collection of the control target drive units.

As shown in FIG. 7, the plate making and feeding unit 20 receives the master roll 2 based on a command from the controller 90.
7 of the plate cylinder 1 in the master 22 fed from 2A.
A pressing force required to change the pressing force of the transfer cylinder 9 with respect to the plate cylinder 1 between the back plate-making image area 24 and the front plate-making image area 23 along the direction of the middle arrow A (rotational direction A of the plate cylinder 1). It has a function / structure for forming a plateless region 25 having a predetermined length corresponding to the switching time.

The plate making and feeding unit 20 is shown in FIGS.
As shown in, the master support member 22C for storing and supporting the master 22 so that the master 22 can be paid out from the master roll 22A formed by being wound around the core tube 22B, and the master support member 22C in the master transport direction X2. A thermal head 26 that is disposed on the downstream side and heat-plates the master 22 that is fed from the master roll 22A according to an image signal, a platen roller 27 that rotates and conveys the master 22 while the master head 22 is pressed by the thermal head 26, and a platen. A cutter unit 36, which is disposed between the roller 27 on the downstream side in the master transport direction X2 and the plate cylinder 1 and serves as a master cutting unit that cuts the master 22 that has been plate-made into a predetermined length, the platen roller 27, and the cutter. The first guide plate 28 disposed on the master transport path between the unit 36 and the cutter unit 36. A pair of feed rollers 37a, 37b arranged on the downstream side of the master conveyance direction X2, a pair of plate feed rollers 38a, 38b arranged on the downstream side of the feed rollers 37a, 37b in the master conveyance direction X2, and The flexible box 3 disposed below the master conveyance path between the roller pair 37a, 37b and the plate supply roller pair 38a, 38b.
2 and a guide conveying plate 33, and the like, and a second guide plate 29 disposed downstream of the plate feeding roller pairs 38a and 38b in the master conveying direction X2. The structure of the plate-making plate feeding unit 20 is the same as that shown in FIG. 15 of JP-A-10-193768, for example.

The master 22 is in the form of a continuous sheet, as schematically shown in FIG. 2 with its cross section enlarged and exaggerated. For example, the master 22 has an overcoat layer 221 for preventing sticking and static electricity, and a thermoplastic resin. Resin film 2
22 and the adhesive 22 on the thermoplastic resin film 222.
Porous support (base) 224 bonded by 3
It has a laminated structure composed of and. As the thermoplastic resin film 222, for example, a polyester terephthalate (PET) -based film having a thickness of 0.5 to 5 μm is used. The porous support 224 is made of, for example, thin Japanese paper fibers, and is formed in a manner in which warp-like fibers 224a extending in the longitudinal direction in the plane of the master 22 and weft-like fibers 224b extending in the transverse direction are woven together. , Has ink permeability. The porous support (base) 224 has a function of ensuring the mechanical strength (so-called waist strength) of the master 22. The porous support 224 is not limited to the one made of the above-mentioned Washi fibers, but may be made of thin fibers such as synthetic fibers or a mixture of synthetic fibers and Washi fibers.

In addition to the above-mentioned masters, the master 22 is, for example, a master having a thickness of 0.5 to 3 μm and substantially made of a thermoplastic resin film, or a master in which the thickness of the porous support of the master 22 is thin. May be, for example, JP-A-1
The synthetic fiber base master as described in JP-A-1-77949 may be used, or a master in which a molten resin is applied to a synthetic resin film to integrally form a resin film on the synthetic resin film is also used. be able to. Further, in the cross-sectional structure of the master 22 shown in FIG. 2, an ink-permeable porous layer formed of a resin is arranged below the thermoplastic resin film 222, and the porous layer and Japanese paper are bonded with an adhesive. Also used.

At the center of the master roll 22A, a pipe-shaped core tube 22 protruding from both end faces of the master roll 22A is provided.
B is provided. The master support member 22C is the core tube 2
It is provided on a plate-making side plate (not shown) so as to rotatably support both end portions of 2B. The master roll 22 of the plate making plate feeding unit 20 shown in FIGS. 1 and 3.
In A, the surface of the thermoplastic resin film 222 is an example of inner winding, but a master roll in which the surface of the thermoplastic resin film 222 is outer winding can of course be used.

As shown in detail in FIG. 3, the thermal head 26 has a heating element 26a also called a plurality of heating elements arranged along the main scanning direction corresponding to the axial direction of the platen roller 27. It has a function and a structure as a plate making means for selectively heating the heating element 26a by selectively energizing the heating element 26a to heat and melt the portion of the master 22 corresponding to the heating position to perforate. The thermal head 26 is provided so that it can be brought into contact with and separated from the platen roller 27 by a contacting / separating means (not shown). The platen roller 27 is rotatably supported by the plate making side plate via a roller shaft (not shown), and has a driven gear arranged on the roller shaft and a drive gear (both shown in the drawing) meshing with the driven gear. The master 22 is rotated by a master conveyance motor 30 connected via a drive transmission system composed of, for example, and the master 22 is conveyed to the downstream side in the master conveyance direction X2 while being pressed against the thermal head 26. Master transport motor 30
Is, for example, a stepping motor.

The cutter unit 36 is connected to a cutter motor (not shown) via a wire and a wire pulley, and is constituted by a known rotary blade which is rotationally moved in the width direction of the master 22 by the rotational driving of the cutter motor. The downstream end of the first guide plate 28 in the master transport direction X2 serves as a fixed blade of the cutter unit 36. When the cutter unit 36 is not in operation, the cutter unit 36 is on standby at one end of the master transport path so as not to interfere with the transport of the master 22 that has already made a plate and the master 22 that has not made a plate.

In the pair of feed rollers 37a and 37b, the upper roller is a driving roller and the lower roller is a driven roller. The upper driving roller is a pulley or an endless belt (both not shown). It is connected to the master conveyance motor 30 via the rotation transmission means. Similarly, in the plate feeding roller pair 38a, 38b, the upper roller is a driving roller and the lower roller is a driven roller. It is connected to the master conveyance motor 30 via a rotation transmission means (both not shown) or the like. The electromagnetic clutch is a plate feed roller pair 3
It has a function of intermittently transmitting the rotational driving force of the master conveyance motor 30 to 8a and 38b. Instead of the electromagnetic clutch, a stepping motor different from the master transport motor 30 may be provided for rotationally driving only the plate feed roller pair 38a, 38b.

The master stock means 31 is mainly composed of a bending box 32, a guide transport plate 33, a transport plate drive motor (not shown), a suction fan 34 and a suction fan motor (not shown). The master stock means 31 is
The plate 22 has a function of forming a bend in the plate-making master 22 and temporarily storing the bend. Flexible box 3
2 is formed by being bent into an L shape on the downstream side in the master transport direction X2. The bending box 32 has a function of sequentially storing the plate-made master 22 in which the bending is formed. A suction port 32b and an exhaust port 32, which are slits, mesh-shaped small holes, or the like, are provided on the inner side (right side in FIG. 1) of the flexible box 32 located on the downstream side in the master transport direction X2.
c is provided. These suction port 32b and exhaust port 3
A suction fan 34 rotated by the suction fan motor is disposed at the end of the flexible box 32 between the suction fan 34 and 2c. By the rotational drive of the suction fan motor, the suction fan 34 is rotated to generate an air flow that flows from the left side to the right side in the drawing, and the master 22 that has been plate-finished is gradually bent.

The guide transport plate 33 is positioned below its master guide surface in the master transport direction X2 to guide the master 22 which has been prepressed. The guide transport position shown in FIG. It is openable and closable between the plate forming roller 38b on the right side and a bending forming position (see FIG. 3) that hangs downward to the right to position the master guide surface. When the guide transport plate 33 occupies the bending formation position, the upper side of the bending box 32 is opened, and the bending box 32 is opened.
An opening 32a for introducing the master 22 that has been prepressed is formed above the. As shown in FIG. 3, the guide transport plate 33 is integrally formed with arm portions 33a extending to both ends of the shaft 38c of the lower plate feed roller 38b, and the guide transport plate 33 has each arm portion 33a. Axis 3 through
It is swingably supported at both ends of 8c. A fan-shaped sector gear (not shown) for swinging the guide transport plate 33 between the guide transport position and the flexure forming position about the shaft 38c is provided on the arm portion 33a on the back side of the paper in FIG. Has been. On the other hand, on the plate side plate side, the transport plate drive motor provided with a drive gear (not shown) that constantly meshes with the sector gear is fixed.

After the master cutting after the completion of the plate making operation, the guide carrying plate 33 performs the rotation transmission operation of the drive gear and the sector gear by the forward rotation of the carrying plate drive motor for the next plate making preparation. Through the movement from the flexure forming position to occupy the guide conveyance position, the tip of the plate-finished master 22 does not fall into the flexure box 32 from the opening 32a. It is designed so that it is conveyed to the plate-making standby position shown in. Further, the guide transport plate 33 occupies the guide transport position after the master cutting after the completion of the plate making operation, and then the transport plate drive motor is driven in the reverse direction so that the leading end of the master 22 which has been plate-made is a plate feed roller pair. After being nipped by the nip portions 38a and 38b to reach the plate-making standby position, it is again movable to the flexure forming position. The operation of the master stock means 31 is as follows.
The following is a brief description.

For the sake of convenience of explanation, the front end of the master 22 which has completed the plate making standby position has the plate feed roller pair 38a, 38b.
Although the position where the master 22 is sandwiched by the nip portion of the master roller 22 is actually the front end of the master 22 which has been prepressed,
The position is held by the nip portion of b, because the master 22 is not used in vain. In addition, for the same reason as above, the master 22 that has been prepressed is not limited to the above-mentioned positions.
The position on the downstream end of the first guide plate 28 whose tip is cut by the cutter unit 36 may be the plate making standby position. 1 and 3, the thermal head 26
The length of the master conveying path from the plate feeding roller pair 38a, 38b to the nip portion is exaggeratedly drawn long.
In order to eliminate the useless use of 2, the length is actually set shorter than shown in each figure. The second guide plate 29 has a function of changing the direction of the tip of the master 22 that has been prepressed and guiding the master 22 that has been prepressed substantially vertically downward in the drawing.

A thermal head 26 in the plate making and feeding unit 20, a thermal head drive circuit 26A for driving the thermal head 26, a master transport motor 30,
A master conveyance motor drive circuit 30A for driving the master conveyance motor 30, the cutter motor, the electromagnetic clutch, the suction fan motor, the conveyance plate drive motor, and other control target drive portions are collectively shown in the block of FIG. Only in the figure, the plate-making / plate-feeding drive unit is designated by reference numeral 39.

The plate cylinder 1 is, as shown in FIGS. 1 and 3,
A support shaft 3 for rotatably supporting the plate cylinder 1 in the direction of arrow A in the drawing (hereinafter referred to as "rotational direction A") via end plates (not shown) provided at both ends of the plate cylinder 1, and A support cylinder 2A having a large number of ink-permeable holes 2a (shown only in FIG. 3) that are fastened to the outer circumference of each end plate with screws or the like, and are wound around the outer circumference of the support cylinder 2A. Single-layer (one sheet) mesh screen 2 which has a stable ink permeability
B, and the plate feed roller pair 38a, 3 of the plate making plate feed unit 20
It is mainly composed of a clamper 4 for sandwiching and locking the leading end of the master 22 having been plate-prepared from 8b, an ink supply means 5 for supplying ink to the inner peripheral surface of the plate cylinder 1, and the like.

The support shaft 3 extends on the front side and the back side of the paper surface of FIG. 1 and also serves as an ink supply pipe described later.
The support cylinder 2A is formed by bending it into a cylindrical shape using a thin plate of stainless steel, for example. Support cylinder 2
A large number of fine holes 2a of A are formed in the outer periphery of the support cylindrical body 2A excluding the peripheral portion of the clamper 4 and the side edge regions of the end plates. Thereby, the support cylinder 2A
Together with the mesh screen 2B form a printable region and a non-printable region of the plate cylinder 1.

The mesh screen 2B is formed of, for example, a resin or metal net. As shown in detail in FIG. 4, the mesh screen 2B includes a back side printing area 118 corresponding to the back side plate making image area 24 in the plate making completed master 22 shown by a chain double-dashed line wound on the mesh screen 2B, and a front side. A front surface printing area 117 corresponding to the plate making image area 23 is formed. In addition,
In FIG. 4, the front side plate-making image area 23, the back side plate-making image area 24, and the plate-less plate-making area 25 in the master 22 that has been made
The parentheses are attached to the respective symbols to indicate that they are distinguished from the mesh screen 2B. The reference numeral indicated by arrow A in FIG. 4 corresponds to the rotation direction A of the plate cylinder 1.

In the printing area 117 for the front surface and the printing area 118 for the back surface, fine mesh-shaped openings are formed at least over the size of the printing paper used. In the first embodiment, for simplification of the description, it is assumed that the area is formed to be the same as the area when the printing paper size used is A3 (horizontal). As a result, the front surface printing area 117
Surface printing area length L1 along the rotation direction A of the plate cylinder 1
17 is equal to the back surface printing area length L118 along the rotation direction A of the back surface printing area 118, which is 297 mm in an embodiment. The length L25 corresponding to the plateless region 25 is 40 to 100 mm as described later.

The opening ratio of the mesh screen 2B in the back printing area 118 is set to be larger than that in the front printing area 117, and the switching position of the opening ratio is wound around the mesh screen 2B. It exists in correspondence with the plate-less area 25 of the master 22 that has been plate-made.
In the example shown in FIG. 4, the switching position of the aperture ratio is bounded by an alternate long and short dash line demarcating the center of the plate-making area 25 of the master 22 which has been plate-made. Here, "the opening ratio of the mesh screen 2B in the back side printing area 118 is set to be larger than that of the front side printing area 117" means, for example, that the fiber diameters of the fibers forming the mesh screen 2B are the same. In this case, it means that the mesh value of the mesh screen 2B in the back side printing area 118 is made lower than the mesh value in the front side printing area 117, that is, the eyes are coarse and the ink passage amount is increased. . In the case where the mesh screen 2B is wound in a plurality of layers, as the number of layers of the mesh screen 2B increases, the ink passing amount generally tends to decrease under the same stencil printing conditions.

The clamper 4, as shown in detail in FIG.
In the non-printable area of the support cylinder 2A, it is arranged along one generatrix of the outer peripheral portion of the plate cylinder 1. The clamper 4
It is pivotally attached to the outer peripheral portion of the plate cylinder 1 with a shaft 4a, and can freely come into contact with and separate from the stage portion 4B and can be opened and closed. The clamper 4 has a rubber magnet 4A shown in a satin pattern fixed to a thin metal plate in FIG. 3, and when the plate cylinder 1 occupies a plate discharge position or a plate supply position described later, the main frame 210 side. By the opening and closing device (not shown) installed in
The support cylinder 2A is opened and closed with respect to the stage portion 4B made of a ferromagnetic material provided on the outer peripheral portion of the non-printable area. Speaking of an embodiment, the clamper 4 has a plate made between a rubber magnet 4A having a thickness of about 2 mm and a stage portion 4B having a thickness of about 0.2 to 0.3 mm and made of, for example, a stainless steel thin plate. The tip of the master 22 is clamped and locked. Also,
The surface of the stage portion 4B that is in contact with the tip of the master 22 that has been plate-finished is roughened to increase the coefficient of friction with the tip of the master 22 that has been plate-made. Of the master 22 is prevented from being displaced. The opening / closing device includes an opening / closing member (not shown) that selectively engages the clamper 4, a clamper motor (not shown) that drives the opening / closing member, and the like. For example, Japanese Patent Laid-Open No. 6-247031 It has the same configuration as in FIGS. 1 to 3.

The ink supply means 5 is arranged inside the plate cylinder 1 shown in FIG. The ink supply means 5 is arranged in parallel with the ink supply roller 6 that contacts the inner peripheral surface of the support cylinder 2A of the plate cylinder 1 to supply ink and the ink supply roller 6 with a minute gap therebetween. It is composed of a doctor roller 7 that forms an ink reservoir 8 with the roller 6, and an ink supply pipe 3 that also serves as the support shaft 3 and that supplies ink to the ink reservoir 8. Since the ink supply roller 6 is arranged at a position facing the transfer cylinder 9, the ink supply roller 6 also functions as a backup roller that prevents deformation when the transfer cylinder 9 contacts and presses the plate cylinder 1 during printing. It has become. The mechanism for driving the ink supply means 5 is similar to that shown in FIG. 2 of JP-A-5-229243, for example, and uses the rotational driving force from the main motor 17 shown in FIG. .

The ink is used in order to obtain a good print quality.
For example, a water-in-oil type (W / O type) emulsion ink is preferably used. The ink fed and dropped from the ink supply pipe 3 and stored in the ink reservoir 8 is weighed through a minute gap between the ink supply roller 6 and the doctor roller 7, and a thin film is formed on the outer peripheral surface of the ink supply roller 6. Form an ink line, and excess ink is collected as an ink pool 8. The rotation of the ink supply roller 6 in the rotation direction A in synchronization with the rotation of the plate cylinder 1 and the doctor roller 7 shown in FIG.
With rotation in the direction of the middle arrow B (hereinafter referred to as “rotational direction B”), a fixed amount of ink is supplied from the ink reservoir 8 onto the outer peripheral surface of the ink supply roller 6, and the contact / separation means 120 shown in FIG. When the transfer cylinder 9 is pressed against the plate-making image area 24 for the back surface of the master 22 on the plate cylinder 1 by the operation of, the ink image for the back surface is transferred to the outer peripheral surface of the transfer cylinder 9, and then the printing paper P Is paid,
The transfer cylinder 9 presses the surface of the printing paper P against the surface plate-making image area 23 of the plate-making master 22 on the plate cylinder 1, so that the surface printing corresponding to the surface plate-making image of the plate-making master 22 is performed. An image is printed on the front surface of the printing paper P, and at the same time, an ink image for the back surface on the outer peripheral surface of the transfer cylinder 9 corresponding to the back plate making image of the master 22 that has been prepressed is printed on the back surface of the printing paper P, respectively.

As shown in FIGS. 1 and 5, the transfer cylinder 9 is disposed near the lower part of the plate cylinder 1 facing the ink supply roller 6 in the plate cylinder 1. The transfer cylinder 9 is attached to the outer peripheral portion 9a of the transfer cylinder 9 by the contacting / separating means 120 shown in FIG.
Is provided so as to be capable of rising and swinging between a pressing position where it comes into contact with and presses the outer peripheral surface of the plate cylinder 1 and an outer peripheral portion 9a of the transfer cylinder 9 between a printing pressure releasing position which is separated from the outer peripheral surface of the plate cylinder 1. There is. The transfer cylinder 9 has a concave portion 11 recessed from the outer peripheral portion 9a in order to avoid contact between the cylindrical outer peripheral portion 9a and a protruding portion of the plate cylinder 1 in the vicinity of the clamper 4 arrangement portion. It is arranged on the delay side of the rotation direction B and holds the leading end of the printing paper P fed from the paper feeding unit 40 (hereinafter,
The paper clamper 12 and the like are included.

The transfer cylinder 9 is rotatably supported around a transfer cylinder shaft 10 arranged at the center of the transfer cylinder 9. Transfer cylinder 9
The diameter of is 1/2 that of the plate cylinder 1. The transfer cylinder 9 and the plate cylinder 1 are rotationally driven by a drive mechanism to be described later such that the peripheral speeds of the transfer cylinder 9 and the plate cylinder 1 match each other during transfer of the back side ink image onto the transfer cylinder 9 and double-sided printing. Therefore, the transfer cylinder 9 rotates twice while the plate cylinder 1 rotates once.

The surface layer of the outer peripheral portion 9 of the transfer drum 9 is made of an ink-repellent and cleaning solvent-permeable material. The ink-repellent and cleaning solvent-permeable material is used to obtain a printed material with less set-off, bleeding, strike-through, etc. as described in the prior art, and to improve the cleaning performance after transfer. Silicone rubber (Q), which is a material having excellent smoothness and excellent ink repellency, cleaning solvent permeability, and ink resistance.
Is used. Thus, the outer peripheral portion 9a of the transfer cylinder 9
By forming the surface layer of No. 2 from silicone rubber, it is possible to reduce the oil-based component of the ink image for the back surface formed by transferring the ink from the plate cylinder 1 to the surface of the outer peripheral portion 9a of the transfer cylinder 9. It is possible to increase the drying speed of the back surface print image formed by being retransferred to the back surface of the paper P,
As a result, it is possible to prevent bleeding images, strike-through, strike-through, and the like.

Ink that has passed through the back side plate making image (not shown) in the back side plate making image area 24 of the plate making master 22 wound on the plate drum 1 from the inside of the plate cylinder 1 Transferred to the silicone rubber layer on the outer periphery 9a,
A back side ink image 19 shown in FIG. 10 and the like described later is formed. In this case, the ink immediately after being transferred from the plate cylinder 1 to the transfer cylinder 9 is in an ink state in which the water-based component and the oil-based component coexist. As time passes, part of the oil-based component in the ink state penetrates into the silicone rubber layer due to the solvent penetration property of the silicone rubber. At this time, in the ink state on the surface of the outer peripheral portion 9a of the transfer cylinder 9 in the ink state, a small amount of oil-based components and water-based components due to the water repellency of the silicone rubber layer remain. In this state, the back surface ink image 19 is retransferred to the back surface of the printing paper P, that is, it is retransferred to the back surface of the printing paper P with a small amount of oil-based components. At this time, the aqueous component is absorbed by the printing paper P and decreases. For this reason, the untransferred ink remaining on the surface of the outer peripheral portion 9a of the transfer drum 9 after the retransfer is in a powder state mainly containing a pigment containing less oil-based components and water-based components.

The outer peripheral portion 9a inside the surface layer of the transfer drum 9 is wound with, for example, nitrile rubber to reduce uneven rotation of the transfer drum 9. Resin is used to reduce weight.

The paper clamper 12 adopts a clamp system using a magnet, and the paper clamper 1
Reference numeral 2 has its base end fixed to a paper clamper shaft arranged in the recess 11, and is always urged in a closing direction by a spring (not shown). The paper clamper 12 holds the print paper P on the outer peripheral surface of the transfer cylinder 9 by opening the paper clamper 12 at a predetermined timing by a cam (not shown) arranged on the main body frame 210 side, holding the front end of the print paper P, and then closing it. To do.

As shown in FIG. 1, the transfer cylinder 9 rotates in the direction of arrow B (counterclockwise direction), and printing is performed at the rotational position of the paper clamper 12 on the transfer cylinder 9 (hereinafter referred to as "paper gripping position"). After the leading edge of the paper P is abutted against the paper clamper 12 (at this time, the rotation position of the plate cylinder 1 is the position where the plateless area 25 of the printed master 22 on the plate cylinder 1 is closest to and opposed to the paper clamper 12). When the paper clamper 12 is closed, the leading edge of the printing paper P is moved to the paper clamper 12
Is held and held by. Next, the transfer cylinder 9 further rotates in the direction of the arrow B, and the rotational position (hereinafter referred to as "paper ejection position") slightly advanced from the position where the paper clamper 12 on the transfer cylinder 9 faces the ink supply roller 6 of the plate cylinder 1. Then, the paper clamper 12 is opened, and the ink image for the back surface on the outer peripheral surface of the transfer cylinder 9 is transferred to the back surface of the printing paper P, and at the same time, the ink from the plate-making image for the surface on the plate cylinder 1 is transferred to the surface of the printing paper P. Since the leading edge of the printing paper P is discharged at a position that is beyond the nip portion, which is the printing portion between the plate cylinder 1 and the transfer cylinder 9, which corresponds to the timing of the transfer, the printing paper P is printed by the adhesive force of the ink. There is also an advantage that the body 1 is not rolled up. The detailed structure around the paper clamper 12 is the same as that disclosed in FIGS. 1 to 7 of JP 2000-238400 A proposed by the applicant of the present application, for example.

Next, referring to FIG. 5, the transfer cylinder 9 is set to the plate cylinder 1.
The contacting / separating means 120 for contacting / separating with respect to will be described. The reason for providing the contacting / separating means 120 is as follows. That is, in the printing apparatus using the transfer drum 9, under the condition that printing is performed, that is, the printing paper P is present between the plate drum 1 and the transfer drum 9, the outer circumference of the transfer drum 9 is reduced. The portion 9a is relatively the outer peripheral surface of the plate cylinder 1 (the portion excluding the clamper 4 arrangement portion)
Must be pressed against the printing paper P or the master 22 when the power is turned off, the plate is fed or discharged, or the color is changed.
The outer periphery of the plate cylinder 1 under the condition that the printing paper P does not exist between the plate cylinder 1 and the transfer cylinder 9 at the time of the plate cylinder replacement such as the jam treatment or the maintenance, that is, the non-printing. If the surface comes into direct contact with the surface of the outer peripheral portion 9a of the transfer cylinder 9, the ink on the surface of the plate cylinder 1 adheres to the surface of the outer peripheral portion 9a of the transfer cylinder 9 and causes inconvenience such as back stain during printing. It is necessary to separate the transfer cylinder 9 from the plate cylinder 1 and hold the transfer cylinder 9 in the printing pressure release position so that the printing pressure by the transfer cylinder 9 is not applied to the plate cylinder 1. Therefore, in order to control the contact / separation of the transfer cylinder 9 with respect to the plate cylinder 1, a contact / separation unit 120 is provided. In other words, the transfer cylinder 9 causes the contact / separation unit 120 to convey the printing paper P (the guide plate pair 45 shown in FIG. 1).
a, 45b, which is a conveyance path guided and demarcated and a conveyance path on an extension line of the conveyance path. The distance between the outer peripheral surface of the plate cylinder 1 and the surface of the outer peripheral portion 9a of the transfer cylinder 9 is set to be extremely small, for example, about 2 mm in order to reduce noise during printing as much as possible.

As shown in FIG. 5, the contacting / separating means 120 includes a transfer cylinder moving arm 121, a cam follower 122, an arm stopper 123, a solenoid 124, and a return spring 12.
5, a transfer cylinder displacement cam 126, a tension spring 127, a support shaft 128, and the like. Transfer cylinder moving arm 1
A pair of the transfer cylinder moving arms 121 and 121 are arranged on the front side and the back side of the paper surface of FIG. ing. The transfer cylinder moving arm 121 on the front side of the paper surface of FIG. 5 is omitted. The transfer cylinder moving arms 121, 121 have a pair of support shafts 128, 128 planted in the same phase on the front side and the back side of the main body frame 210 in the plane of FIG. Is used as a fulcrum, and is swingably supported between the pressing position and the printing pressure releasing position so as to raise and swing the transfer cylinder 9. Hereinafter, in FIG. 5, since the transfer cylinder moving arms 121, 121 and the support shafts 128, 128 are the same, one side thereof will be described, and the support shaft 128 of the transfer cylinder moving arm 121 will be used as a center in FIG. Since both the left free end and the right free end can swing, these names will be used as they are.

When the transfer cylinder moving arm 121 moves the transfer cylinder 9 to the printing pressure release position, it is locked by the arm stopper 123 located at the tip of the right free end of the transfer cylinder moving arm 121 (right end in FIG. 5). It has become. The arm stopper 123 is an arm swingable around a fulcrum pin 123a arranged on the body frame 210 side, and a plunger 124a of a pull type solenoid 124 is connected to the free end side of the arm stopper 123 via a pin. There is. An extendable return spring 125 is arranged between the plunger 124a and the arm stopper 123, and the elastic force of the return spring 125 causes the arm stopper 123 to engage with the tip of the right free end of the transfer cylinder moving arm 121. It is urged to match.

When the solenoid 124 is off, the elastic force of the return spring 125 causes the arm stopper 123 to move.
Engages with the right free end of the transfer cylinder moving arm 121. On the other hand, the leading edge of the printing paper P fed from the paper feeding unit 40 is detected by the paper detection sensor 115 arranged in the paper conveyance path between the transfer cylinder 9 and the pair of registration rollers 44a and 44b shown in FIG. The solenoid 124 is detected, and in response to a command from the control device 90 based on the detection signal.
Is turned on, the plunger 124a is pulled so that the arm stopper 123 is moved to the transfer cylinder moving arm 1.
Since it is separated from the right end of the free end of the arm 21, the engagement between the arm stopper 123 and the end of the right free end of the transfer cylinder moving arm 121 is released. As described above, each of the claw shapes of the arm stopper 123, the solenoid 124, the return spring 125, the arm stopper 123, and the tip of the right free end of the transfer cylinder moving arm 121 has a printing pressure that holds the transfer cylinder 9 in the printing pressure release position. The releasing means 129 is configured.

The support shaft 10 of the transfer drum 9 is supported on a part of the left free end of the transfer drum moving arm 121.
Further, a cam follower 122 is rotatably supported by a shaft 122a embedded in the transfer cylinder moving arm 121 between the support shaft 128 and the tip portion of the right free end. The cam follower 122 faces the transfer cylinder displacement cam 126, which is an eccentric cam rotatably provided on the body frame 210 side. The transfer cylinder displacement cam 126 is integrally fixed to the cam shaft 126a, and is rotationally driven by the main motor 17 shown in FIG. The transfer cylinder displacement cam 126 swings and displaces the transfer cylinder moving arm 121 so that the transfer cylinder 9 occupies the pressing position when the small diameter portion faces the cam follower 122, and when the large diameter portion faces and slides against the cam follower 122. The transfer cylinder moving arm 121 can be oscillated and displaced so that the transfer cylinder 9 occupies the printing pressure releasing position, and the right free end of the transfer cylinder moving arm 121 can be placed at a position where it can be engaged with the arm stopper 123. It is formed in such a shape. The tension spring 127 applies an urging force in a direction in which the transfer cylinder moving arm 121 is swung in a direction in which the cam follower 122 provided in the transfer cylinder moving arm 121 is brought into contact with the transfer cylinder displacement cam 126, and the transfer to the plate cylinder 1 is performed. It also serves to apply a pressing force to the body 9.
One end of the tension spring 127 is locked between the tip of the right free end of the transfer cylinder moving arm 121 and the transfer cylinder moving arm 121 of the cam follower 122 support portion, and the other end is locked to the end of the rack 133 described later. Has been done. The transfer cylinder displacement cam 126 is incorporated in a drive system of the plate cylinder 1 and the transfer cylinder 9, which will be described later.

The contacting / separating means 120 performs the following operation. For the sake of convenience of explanation, it is assumed that the other end of the tension spring 127 is locked to the end of the rack 133 held at a certain position and the tension length thereof is constant. First, when the transfer cylinder 9 is set to the printing pressure release position which is also the position retracted from the conveyance path of the printing paper P, the transfer cylinder displacement cam 126 is arranged so that the large diameter portion of the transfer cylinder displacement cam 126 faces the cam follower 122. The rotational position of 126 is determined. As a result, the right free end of the transfer cylinder moving arm 121 swings counterclockwise about the support shaft 128 as a fulcrum.
Displaced to a position where it can be locked by the arm stopper 123,
The tip of the right free end of the transfer cylinder moving arm 121 resiliently engages with the free end of the arm stopper 123 against the elastic force of the return spring 125. As a result, the transfer cylinder 9 is pulled by the tension spring 127 that is hung on the transfer cylinder moving arm 121.
It is held at the printing pressure release position against the urging force of.

Next, when the transfer cylinder 9 is set to the pressing position which is also the position for advancing to the conveying path of the printing paper P, the solenoid 124 is turned on and the plunger 124a is resisted against the biasing force of the return spring 125. Is pulled, whereby the free end of the arm stopper 123 swings in the counterclockwise direction to release the tip of the right free end of the transfer cylinder moving arm 121 and release the locked state with the transfer cylinder moving arm 121. To do. As a result, the right free end of the transfer cylinder moving arm 121 swings in the clockwise direction about the support shaft 128 as a fulcrum by the urging force of the tension spring 127, whereby the cam follower 1 is moved.
22 is displaced in the direction in which it comes into contact with the transfer cylinder displacement cam 126. The cam follower 12 is attached to the small diameter portion of the transfer cylinder displacement cam 126.
By determining the rotational position of the transfer cylinder displacement cam 126 so that the two faces, the transfer cylinder 9 occupies the pressing position.

When the right free end of the transfer cylinder moving arm 121 is swung clockwise by the urging force of the tension spring 127 about the support shaft 128 as a fulcrum, the transfer cylinder moving arm 1 is moved.
Since a stopper member (not shown) for restricting the clockwise swinging range of the right free end of 21 is provided on the body frame 210 side, the small diameter portion of the transfer cylinder displacement cam 126 and the cam follower 122 are slightly different. It is arranged to face each other in a non-contact state while maintaining a large gap. As a result, the pressing force by the urging force of the tension spring 127 when the outer peripheral surface 9a of the transfer cylinder 9 is pressed against the outer peripheral surface of the plate cylinder 1 is efficiently and accurately applied. The printing paper P when the double-sided printing operation is performed is sandwiched between the transfer cylinder 9 and the plate cylinder 1, and the front and back surfaces of the printing paper P are pulled by the transfer cylinder 9 by the tension spring 1
The pressing force corresponding to the biasing force of 27 is received. In this case, the pressing force is maintained constant unless an external force acts on the tension spring 127 and the like.

The first embodiment has the pressing force varying means 130 for changing the pressing force. By the way, the pressing force varying means 130 according to the first embodiment is used to transfer the pressing force of the transfer cylinder 9 to the plate cylinder 1 at the time of transferring the backside plate-making image formed on the master 22 having been plate-made, and the plate at the time of double-sided printing. It is also used when changing the printing pressing force of the transfer cylinder 9 with respect to the cylinder 1.

The pressing force varying means 130 is shown in FIG. 5 and FIG.
As shown in FIG. 3, the pressing force variable motor 131 including a stepping motor, the pinion 132 fixed to the rotating shaft of the pressing force variable motor 131, and the rack 13 that is locked to the other end of the tension spring 127 and constantly meshes with the pinion 132.
3. The light shielding plate 134 protruding downward from the bottom wall of the rack 133 and the rack 1 provided so as to sandwich the light shielding plate 134.
A home position sensor 135 for detecting the home position of 33 is mainly configured. Rack 133
Is supported by a guide member (not shown) provided on the main body frame 210 side so as to be movable in the extension / contraction direction of the tension spring 127. The home position sensor 135 is a transmissive optical sensor including a light emitting element and a light receiving element, and is provided on the body frame 210 side.

A double-sided printing mode is set through a key operation to be described later on the operation panel 140 shown in FIG. 8, and an output signal related to the double-sided printing mode setting is output to the control device 90 shown in FIG.
9 is input to the pressing force variable motor drive circuit 131A shown in FIG. 9, which causes the pressing force variable motor 131 to be driven.
Rotates for a predetermined number of steps. The rack 133 is moved by the rotational driving of the pressing force variable motor 131, the spring strength is changed by changing the tension length of the tension spring 127, and the outer peripheral portion 9a of the transfer cylinder 9 is changed with respect to the outer peripheral surface of the plate cylinder 1.
The pressing force when is pressed changes. In FIG. 5, when the rack 133 moves in the direction of arrow C, the tension length of the tension spring 127 becomes long and the pressing force increases, and when it moves in the direction of arrow D, the pressing force decreases.

Next, referring to FIG. 7, a plate at the time of transfer of the plate-making image (not shown) for the back side of the plate-making master 22 wound on the plate cylinder 1 shown by a chain double-dashed line in FIG. The relationship between the transfer pressing force F1 of the transfer cylinder 9 against the cylinder 1 and the printing pressing force F2 of the transfer cylinder 9 against the plate cylinder 1 during double-sided printing will be described. In the graph shown on the lower side of FIG.
The horizontal axis represents the time t corresponding to the rotation angle of the plate cylinder 1, and the vertical axis represents the pressing force F of the transfer cylinder 9 against the plate cylinder 1, respectively, which represents the transfer pressing force F1 and the printing pressing force F2. Relationship is represented. Further, in FIG. 7, reference numeral L23 is the length of the surface plate-making image area of the surface plate-making image area 23 along the rotation direction A of the plate cylinder 1 (which is also the master transport direction X2), and reference numeral L24 is the rotation direction of the plate cylinder 1. The length of the backside plate-making image area of the backside plate-making image area 24 along the line A is denoted by L25.
The plate-free area length of the plate-free area 25 along the rotation direction A of FIG.

As described above, the master 22 which has been plate-made has the plate-making image area 24 for the back surface and the plate-making image area 24 for the surface along the rotation direction A of the plate cylinder 1 by the plate-making plate feeding unit 20 which receives a command from the controller 90. Between the plate-making image area 23, the plate cylinder 1
A plateless region 25 having a predetermined length corresponding to the pressing force switching time required to change the pressing force F of the transfer cylinder 9 with respect to is formed.

In the operation of the first embodiment, which will be described later, when the plate cylinder 1 rotates in the rotation direction A, the back plate-making image area 24 to the front plate-making image area 23 in the plate-making master 22 on the plate cylinder 1 are processed. , The pressing force varying means 130 is actuated to change the pressing force F to the plate cylinder 1. Especially, the mechanical operating portion of the pressing force varying means 130 (from the rotational movement by the pinion 132 and the rack 133 to the linear movement). Since there is a relatively large time delay due to the conversion operation of (1) and the swinging of the transfer cylinder moving arm 121 due to the change in the tension length of the tension spring 127, the pressing force cannot be suddenly changed. Need time. Therefore, the plate-less region length L25 exists in an amount corresponding to the pressing force switching time required to change the pressing force of the transfer cylinder 9 with respect to the plate cylinder 1. That is, in the first embodiment, it is possible to switch from the pressing force F1 at the time of transfer to the pressing force F2 at the time of printing at the rotational position of the plate cylinder 1 corresponding to the plate-making region 25 of the master 22 on the plate cylinder 1 which has been already made. It has two characteristics.

Further, under normal plate-making printing conditions (for example, when both the front side image and the back side original image are character images), the transfer pressing force F1 is larger than the printing pressing force F2 as shown in FIG. It is set in advance so as to be large by experiments or the like. By having the control configuration for controlling the pressing force varying means 130, the transfer pressing force F1 is controlled to be larger than the printing pressing force F2, so that the ink passage amount in the back side plate-making image area 24 is increased. Is larger than that of the front side plate-making image area 23, thereby preventing occurrence of image density unevenness between the front side print image and the back side print image during double-sided printing, and reducing the image density difference. It will be easy to do.

As shown in FIG. 7, the A3 size plate-making image is displayed on the front side plate-making image area 23 and the back side plate-making image area 2.
Assuming that two surfaces are taken as 4, and the rotation speed (printing speed) of the plate cylinder 1 is 120 rpm, which is the maximum speed, and also considering the clamper 4 arrangement area of the plate cylinder 1, the diameter of the plate cylinder 1 is approximately 330 mm, The peripheral speed is about 2073 mm /
It becomes sec (second). Further, when the control system shown in FIG. 9 for changing the pressing force and the load of the pressing force variable motor 131 are taken into consideration, the response time for that is 0.
02-0.05 sec is required. Taking all of these into consideration, the plate-less region length L25 is about 40 to 100 mm. However, the numerical range of the plate-less region length L25 is the actual machine used this time (a preport JP manufactured by Ricoh Co., Ltd. equipped with a pressing force varying means 130).
5550 is used), and it is considered that the platemaking region length L25 is further reduced if the response time of the control system and the pressing force variable motor is fast.

The contacting / separating means is not limited to the above-mentioned contacting / separating means 120, and, for example, JP-A-10-25 proposed by the applicant of the present application.
The contact / separation means (7
It may have the same configuration as that of 0). Further, the pressing force changing means is not limited to the pressing force changing means 130, and for example, the tension spring 127 may be provided on the transfer cylinder moving arms 121 and 121 and the main body frame 210 on the front side and the back side of the paper surface of FIG.
On the side, a pair is arranged with the same spring load and the same length, and the tension length of the pair of tension springs 127, 127 is adjusted by the same two pressing force variable motors 131 or one pressing force variable motor 131. You can also do it. The pressing force changing means is not limited to the pressing force changing means 130, but may be the pressing force changing means (900) as described in paragraph No. (0043) of the specification of JP-A No. 11-48594 and FIG. 5, for example. Good.

Next, referring to FIGS. 1 and 3, the plate cylinder 1
A configuration around a drive mechanism as an example of a drive system that rotationally drives the transfer drum 9 will be described. The plate cylinder 1 is shown in FIG.
As shown in FIG. 5, the motor is rotated via a drive system including a main motor 17 via a motor drive circuit described later so that the rotational speed can be changed corresponding to a plurality of printing speeds. A DC motor for control is preferably used as the main motor 17 in order to secure a sufficient drive torque.
Well-known braking means is attached to this DC motor.
The main motor 17 is not limited to the above DC motor,
It may be a pulse-driving type such as a stepping motor.

In FIG. 3, an encoder 151 is attached to the output shaft 17a of the main motor 17.
The encoder 151 is composed of an incremental type photo rotary encoder. The main body frame 210 near the encoder 151 is provided with an encoder sensor 152 including a transmissive optical sensor including a light emitting element and a light receiving element for holding the encoder 151 at a predetermined interval. By detecting a predetermined pulse generated by the encoder sensor 152 in cooperation with the rotation operation of the encoder 151 by the rotation driving of the main motor 17,
The rotation speed of the plate cylinder 1 is detected. As a result, the rotation speed of the plate cylinder 1 is controlled via the main motor 17.

The drive mechanism is disposed on the body frame 210 side on the back side of the paper surface of FIGS.
The drive mechanism is, for example, the above-mentioned Japanese Patent Laid-Open No. 10-258566.
Paragraph Nos. (0025) to (003) of Japanese Patent Publication No.
0) and a mechanism substantially similar to the mechanism described in FIGS. 1 and 2. That is, a toothed drive pulley (corresponding to the pulley (141) of the above publication) fixed to the output shaft 17a of the main motor 17 and a cam shaft 126a of the transfer cylinder displacement cam 126 (the shaft (5 of the above publication).
(Corresponding to 5)) and a cam drive pulley with teeth (not shown) integrally provided (corresponding to the pulley (56) in the above publication).
And two large plate cylinders with teeth (not shown) (corresponding to the pulley (47) of the above publication) integrally provided on an end plate (not shown) of the plate cylinder 1 and a plate cylinder with teeth (not shown). A small pulley (corresponding to the pulley (46) in the above publication), a toothed cam drive belt (not shown) wound between the drive pulley, the cam drive pulley, and the plate cylinder pulley small (the publication). Belt (48)) and transfer cylinder 9
And an unshown Oldham shaft joint (corresponding to the Oldham shaft joint (83) in the above publication) interposed between one end and the other end of the transfer drum support shaft 10 fixed to the end plate of A transfer drum gear (not shown) integrally provided on the other end side of the shaft 10 (corresponding to the impression drum gear (44-1) of the above publication).
An idle gear (not shown) provided on the main body frame side so as to always mesh with the transfer cylinder gear (corresponding to the gear (50b) in the above publication), and a tooth not shown provided coaxially with the idle gear. (Corresponding to the pulley (50a) in the above publication) and a belt with teeth (not shown) (belt (43-1) in the above publication) wound between the size of the plate cylinder pulley and the pulley. Equivalent) and is mainly composed of.

In the drive mechanism, for example, the transfer cylinder gear and the idle gear are configured with the same tooth number ratio, and the diameter of the plate cylinder pulley is large (or the tooth number ratio).
Is set to twice that of the above idle pulley.
As a result, the transfer cylinder 9 and the plate cylinder 1 are rotationally driven so that the peripheral velocities of the transfer cylinder 9 and the plate cylinder 1 are the same at the time of transferring the back side ink image to the transfer cylinder 9 and at the time of double-sided printing. The transfer cylinder 9 rotates twice during one rotation.
The diameter of the drive pulley (or the number of teeth) and that of the cam drive pulley are set so that the transfer cylinder displacement cam 126 makes one rotation while the plate cylinder 1 makes one rotation. In other words, the shape of the transfer cylinder displacement cam 126 is such that at least the plate-making area corresponding to the plate-making master 22 on the plate cylinder 1 (the area including the plate-making image area 23 for the front surface, the plate-making image area 24 for the back surface, and the plate-less area 25). The transfer cylinder 9 is formed so as to press against the plate cylinder 1.

The drive mechanism is not limited to the one described above, and may be, for example, a planetary gear mechanism provided with a gear group for rotationally driving the plate cylinder 1 and the transfer cylinder 9 (for example, proposed by the applicant of the present application). Paragraph Nos. (0050) to (0060) of the specification of Japanese Patent Application Laid-Open No. 11-20291 and FIG. 3 etc.).

At a predetermined position on the side of the main body frame 210 facing one end plate of the plate cylinder 1, when the plate cylinder 1 occupies the plate feeding position for positioning the clamper 4 on the right side of the plate cylinder 1,
Plate supply position detection sensor 13 for detecting the plate supply position
(Shown only in FIG. 9), and when the plate cylinder 1 occupies a home position where the clamper 4 is located directly below the plate cylinder 1, a home position detection sensor 14 (FIG. 9 only) for detecting the home position. Are shown) and are arranged. The plate feeding position detection sensor 13 and the home position detection sensor 14 are known transmission type optical sensors having a light emitting element and a light receiving element. The plate discharge position is a position in which the plate cylinder 1 opposes the clamper 4 toward the plate discharge peeling roller 51a toward the downstream side in the rotation direction of the plate cylinder 1.
The detection means for detecting the plate ejection position also serves as the home position detection sensor 14, and the plate ejection position is when an on signal is output from the home position detection sensor 14 when the plate cylinder 1 occupies the home position. From the starting point, the amount of rotation (rotation angle) of the plate cylinder 1 by the encoder sensor 152 provided attached to the main motor 17
Is detected by detecting.

As shown in FIG. 1, in the vicinity of the lower part of the transfer drum 9, the ink of the ink image for the rear surface remaining on the surface of the outer peripheral portion 9a of the transfer drum 9 after completion of double-sided printing is removed and cleaned, that is, cleaning. A cleaning unit 100 for cleaning is provided. The cleaning means 100 is
Ink scraping means disposed on the delay side (upstream side) of the transfer cylinder 9 in the rotation direction B to scrape ink on the surface of the outer peripheral portion 9a of the transfer cylinder 9, and the transfer cylinder more than the arrangement part of the ink scraping means. 9
Of the transfer drum 9 disposed on the advance side (downstream side) in the rotation direction B of the transfer drum 9 after being scraped by the ink scraping means.
a Mainly composed of a cloth sheet cleaning means 107 for cleaning the ink on the surface.

The ink scraping means is capable of coming into contact with and separating from the surface of the outer peripheral portion 9a of the transfer cylinder 9, and an ink scraping blade 101 as an ink scraping member, and a casing for collecting and storing the scraped ink. 102 and 102. The ink scraping blade 101 extends in the direction of the transfer cylinder shaft 10 of the transfer cylinder 9, and has, for example, excellent ink resistance,
In addition, it is made of silicone rubber, which is a material that does not scratch the surface of the outer peripheral portion 9a of the transfer cylinder 9. The ink scraping blade 101 has a press-contact position that is lightly pressed against the surface of the outer peripheral portion 9a of the transfer cylinder 9 and a separate position that is separated from the press-contact position to avoid contact with the paper clamper 12 and the like by a contact-separation unit (not shown). It is configured to be freely displaceable between.
The contacting / separating means has, for example, a configuration similar to that of the contacting / separating means 120 shown in FIG.

The cloth sheet cleaning means 107 is a cloth sheet roll 103 in which the cloth sheet 103 is wound in a roll shape.
Cloth sheet roll supporting portion 104 for rotatably supporting A
And a pressure roller 105 that is rotatable in a counterclockwise direction while winding the cloth sheet 103 and is capable of coming into contact with and separating from the surface of the outer peripheral portion 9a of the transfer drum 9, and the cloth sheet 103 to which the ink has been transferred / absorbed. Cloth sheet collecting roller 106
Mainly consists of and.

The cloth sheet 103 is the transfer drum shaft 1 of the transfer drum 9.
It extends in the 0 direction, and has excellent ink absorption, etc.,
Further, it is formed of, for example, acrylic nylon fiber which is a material that does not scratch the surface of the outer peripheral portion 9a of the transfer cylinder 9. The pressure roller 105 is provided between a pressing position where the surface of the outer peripheral portion 9a of the transfer cylinder 9 is lightly pressed by a contacting / separating unit (not shown) and a separating position for separating from the pressing position and avoiding contact with the paper clamper 12. It is configured so that it can be displaced. The contacting / separating means is, for example, the contacting / separating means 1 shown in FIG.
It has a configuration similar to 20. Pressure roller 105
Is a counter to the rotation direction B of the transfer cylinder 9 in the counterclockwise direction, which is a counter to the rotation direction B of the transfer cylinder 9, in order to improve the absorption and cleaning of the ink on the surface of the outer peripheral portion 9a of the transfer cylinder 9 by the cloth sheet 103. It is configured to be rotatably supported on. The cloth sheet collecting roller 106 is rotated by a collecting roller drive motor (not shown) connected to the shaft thereof in the clockwise direction, which is the winding direction of the cloth sheet 103, as indicated by the arrow in the figure. As a result, the pressure roller 105 is driven to rotate counterclockwise.

As described above, the outer peripheral portion 9 of the transfer cylinder 9
Since the surface layer of a is formed of silicone rubber, the ink on the surface of the silicone rubber after double-sided printing is in a powder state mainly containing a pigment component. Therefore, normally, the cleaning can be performed only by transferring and absorbing the ink to the cloth sheet 103, but in the present invention, the cloth sheet cleaning means 107 is arranged in order to more reliably remove and clean the ink on the transfer cylinder 9. The ink scraping means is arranged on the delay side (upstream side) in the rotation direction B of the transfer cylinder 9 with respect to the position. With such an arrangement, the outer peripheral portion 9 of the transfer cylinder 9
Most of the ink present on the surface of a is first scraped by the ink scraping blade 101, and then the cloth sheet cleaning means 107 is used for finish cleaning.

Here, for convenience of description, the detailed operation of the cleaning means 100 will be described. After the double-sided printing of each printing sheet P is completed, first, the ink scraping blade 101 occupies the pressure contact position by the operation of the contacting / separating means so that the ink scraping blade 101 exists on the surface of the outer peripheral portion 9a of the transfer cylinder 9. The untransferred residual ink in a powder state mainly composed of the pigment component is scraped off. The ink thus scraped off is stored in the casing 102. After that, the cloth sheet cleaning means 107 operates to recover the ink that could not be recovered by the ink scraping operation. After that, the ink scraping blade 101 occupies the separated position. That is, at the same time that the collecting roller drive motor operates, the pressing roller 105 wound around the cloth sheet 103 by the operation of the contacting / separating means occupies the pressing position, so that the cloth sheet 103 on the pressing roller 105 is transferred. Rotation direction B of body 9
With respect to the surface of the outer peripheral portion 9a of the transfer drum 9, the ink remaining on the surface of the outer peripheral portion 9a of the transfer drum 9 is removed by being pressed against the surface of the outer peripheral portion 9a of the transfer drum 9 while rotating counterclockwise as a counter.
The cloth sheet 103, which has been transferred and absorbed by No. 3, and whose ink has been transferred and absorbed, is sequentially wound around the cloth sheet collecting roller 106. After that, the pressure roller 105 occupies the separated position.

Main motor 1 in printing plate cylinder device 15
7, a main motor drive circuit 17A for driving the main motor 17, the clamper motor, the contacting / separating means 12
0 of the solenoid 124, the pressing force variable motor 131 of the pressing force varying means 130, the pressing force variable motor drive circuit 131A for driving the pressing force variable motor 131, etc. A plate supply printing drive unit indicated by reference numeral 16 is shown only in the figure. Note that in the block diagram of FIG. 9, each control target drive portion of the cleaning means 100 (for example, a cam drive motor (not shown) configuring each of the above-mentioned contacting / separating means, and the cloth sheet cleaning means 107 is configured for the sake of simplicity. Although the above description of the collecting roller driving motor etc. is omitted, the control device 9 shown in FIG.
Note that it is controlled by 0.

The paper feed unit 40 includes a paper feed tray 41, a paper feed roller 42, a pair of separation rollers 43a and 43b, a pair of guide plates 45a and 45b, and a pair of registration rollers 44a and 44b.
The lift motor (not shown), paper feed motor (not shown), and registration motor (not shown) are mainly configured. The paper feed tray 41 is loaded with print paper P thereon, and is supported so as to be vertically movable with respect to a paper feed side plate (not shown) arranged on the body frame 210 side. The paper feed tray 41 is moved up and down by the lifting motor in conjunction with the increase and decrease of the print paper P. For example, as shown in FIGS. 4A and 4B of Japanese Patent Laid-Open No. 10-193768, the size of the print paper P is linked to the movement of the side fence (49) in the paper feed tray 41. A plurality of paper size detection sensors (47, 48) similar to those for detection are provided.

Paper feed roller 42 and upper separation roller 43a
And are provided so as to contact the uppermost printing paper P. The paper feed roller 42 is a roller that comes in contact with the uppermost printing paper P and picks up the printing paper P in the paper transport direction X3. The separation roller pair 43a and 43b are
It has a well-known function of separating the printing paper P delivered by the paper feed roller 42 into one sheet by the cooperative action thereof and delivering it in the paper transport direction X3. The paper feed roller 42 and the upper separation roller 43a are connected to the paper feed motor, which is a stepping motor, via a rotation transmission means including a pulley, an endless belt, and the like (not shown), and are rotated by the paper feed motor. It The paper feed motor and the rollers 42, 4
A one-way clutch (not shown) is interposed between the shaft 3a and the shaft 3a, and when the paper feed motor is off, the print paper P is rotatable in the feeding direction. Accordingly, when only the registration motor is turned on, or when the printing paper P is sandwiched at the nip portion between the plate cylinder 1 and the transfer cylinder 9 to perform double-sided printing or the like, each roller moves the printing paper P. It is turned around in the feeding direction.

Registration roller pairs 44a and 44b are provided downstream of the separation roller pair 43a and 43b in the sheet conveying direction X3.
Is provided. Registration roller pair 44a, 44b
Is fed by a paper feed roller 42 and a separation roller pair 43
a, 43b grips the leading edge of one sheet of printing paper P that is separated and fed, and sets it to the image writing start position in the surface plate-making image area 23 of the master 22 that has been plate-formed on the rotating plate cylinder 1. It has a function to convey the sheet clamper 12 which has been opened to the spread sheet clamper 12 at a timing while being synchronized with each other.
The pair of registration rollers 44a and 44b are connected to the registration motor via a rotation transmission means including a pulley and an endless belt (not shown), and are rotated by the registration motor. The registration motor is a stepping motor. The pair of guide plates 45a and 45b are fixed to a paper feed side plate (not shown) of the apparatus body and guide the printing paper P to be fed.

The paper feeding unit 40 and the transfer cylinder 9 are provided, for example, in Japanese Patent Laid-Open No. 11-3099 proposed by the applicant of the present application.
Various control components similar to the configuration disclosed in FIGS. 1 and 2 of Japanese Patent Publication No. 34-34, that is, a series of control components for controlling the timing of feeding the leading edge of the printing paper P to the paper clamper 12. Is provided. As a result, after the registration motor is controlled so as to feed the leading edge of the printing paper P in time with the paper gripping position of the paper clamper 12, an output signal from a registration sensor (corresponding to the paper detection sensor 115) not shown. Based on
The registration motor is controlled so that the rotation speed of the lower registration roller 44b is increased to compensate for the slip of the printing paper P on the registration roller pair 44a and 44b.

The control target drive parts such as the paper feed motor, the registration motor, and the lift motor in the paper feed unit 40 are collectively referred to as a paper feed drive indicated by reference numeral 46 only in the block diagram of FIG.

The paper discharge unit 60 includes a paper discharge tray 61, a pair of upper and lower paper discharge peeling claws 62a and 62b, a suction and discharge inlet roller 63, a suction and discharge outlet roller 64, and a conveyor belt 6.
5, a suction fan 66, a paper discharge drive motor (not shown), and a fan motor (not shown).
The paper ejection claw 62a is disposed below the outer peripheral surface of the plate cylinder 1, and the printed printing paper P released from the paper clamper 12 by the opening operation of the paper clamper 12 is placed on the outer peripheral surface of the plate cylinder 1. This is to prevent the roll up. The paper ejection peeling claw 62b is disposed on the main body frame 210 in the vicinity of the paper ejection position on the transfer cylinder 9, and peels the printed printing paper P released from the paper clamper 12 and receives it on the conveyor belt 65. It is something to pass.

The suction and discharge inlet roller 63 and the suction and discharge outlet roller 64 are a discharge side plate (not shown) of the discharge unit 60.
Is rotatably supported, and a conveyor belt 65 having a plurality of openings on its surface is stretched between the rollers. The suction / discharge outlet roller 64 is rotationally driven by the discharge drive motor, and this rotational force is transmitted to the suction / discharge inlet roller 63 via the conveyance belt 65. Each roller 63, 64
A suction fan 66 that is rotated by the fan motor is disposed in the space between and below the sheet discharge side plate.
The suction fan 66 generates a downward airflow in the drawing by its rotation, and sucks the printing paper P printed on the surface of the conveyor belt 65.

The paper discharge drive motor in the paper discharge unit 60, a paper discharge drive motor drive circuit (not shown) for driving the paper discharge drive motor, the fan motor, and a fan motor drive circuit for driving the fan motor (FIG. (Not shown)
The respective control target drive parts such as the above are collectively referred to as a paper discharge drive part indicated by reference numeral 67 only in the block diagram of FIG.

The plate discharge unit 50 further discharges the used master 22 peeled / conveyed and the plate discharge peeling roller pair 51a, 51b for pressing and mutually peeling and conveying the used master 22 from the plate cylinder 1. Plate discharge roller pair 53a, 53b to be conveyed to the box 54, and plate discharge roller pair 53
a, 53b and the plate discharge peeling roller pair 51a, 51b, the plate discharge conveying belt pair 52a, 52b, the plate discharging box 54, the plate discharging peeling roller pair 51a, 51b, the plate discharging conveying belt pair 52a, 52b, and the plate discharging. Coro vs 53
a plate discharge motor (not shown) for rotationally driving a and 53b,
It is mainly composed of the above-mentioned compression plate 55 and a compression plate drive motor (not shown) for driving the compression plate 55 up and down.
One of the plate discharge peeling roller pairs 51a and 51b is provided on one plate discharge peeling roller 51b side so as to be movable by a moving mechanism (not shown) including a link mechanism (not shown), a biasing means, a solenoid, and the like. The plate discharge unit 50 provided with the above-mentioned moving means has the same structure as that shown in FIGS. 1 and 2 of Japanese Patent No. 3061936 (JP-A-5-286223), for example.

The control target drive parts including the plate discharge motor, the solenoid, the compression plate drive motor and the like in the plate discharge unit 50 are collectively referred to as a plate discharge driving portion indicated by reference numeral 56 only in the block diagram of FIG.

As shown in FIG. 8, the operation panel 140 is
1 for operating the stencil printing apparatus 200.
The document reading device 70 shown in FIG. On the operation panel 140, from the image reading of the original 74 to plate making, plate feeding, plate-forming double-sided printing also called test printing,
A plate-making start key 141 for inputting and setting the start of a series of operations up to the paper discharge operation, a double-sided printing setting key 143 for setting a double-sided printing mode in which printing is performed on both sides of the printing paper P at the same time, A numeric keypad 144 for inputting / setting the number of prints and the like, and inputting with this numeric keypad 144
A print start key 142 for activating the printing operation for the set number of prints, and a print speed level as a set value of the print speed, for example, one print speed from five print speeds of 1 to 5 speeds. Print speed setting key 14 including a speed down key 146a and a speed up key 146b as a print speed setting means for selectively setting
6 and the like are provided. The plate-making start key 141 and the double-sided printing setting key 143 have a function as start-up setting means for activating at least the plate-making device portion of the plate-making plate feeding unit 20 when the double-sided printing mode is set.

Also, on the operation panel 140, a double-sided print mode indicator 143A as a double-sided print mode display means for indicating that the double-sided print mode is set by the double-sided print setting key 143, and a speed down key 14 are displayed.
6a or a speed up key 146b, a print speed indicator 147 as a set print speed display means for displaying the set print speed, an operator, a user, etc.
A liquid crystal display device 145 or the like is provided for appropriately displaying and notifying operations and actions to be performed by the "user", settings / detection information in the process, and the like, and issuing a warning to the user's operation result. ing.

The double-sided printing mode display 143A is an LED.
It consists of a (light emitting diode) lamp. Print speed indicator 1
47 consists of a group of LED lamps. Print speed indicator 14
In FIG. 7, the hatched "set print speed: 3rd speed" in the center is the standard print speed corresponding to the print speed that is normally used, and the speed down key 146a or the speed up key 146b was not pressed. It is supposed to be set automatically in case. Here, for example, the leftmost "set print speed: 1st speed" is 60 sheets / the lowest print speed.
min: 60 rpm, "set print speed: 2nd speed" print speed is 75 sheets / min: 75 rpm, "set print speed: 3rd speed" print speed is 90 sheets / min: 90 rpm
"Set print speed: 4th speed" has a print speed of 105 sheets / m
in: 105 rpm, rightmost "setting print speed: 5
“High speed” means that the printing speed is 120 sheets / the highest speed in the first embodiment.
It is set corresponding to min: 120 rpm. The print speed indicator 147 is a speed down key 146a.
Or, by pressing the speed up key 146b once,
The print speed at which the print speed can be switched to any one of the five set print speeds from 1 to 5 is lit and displayed.
As a result, the set print speed selected by the user can be visually confirmed on the print speed display 147.

The liquid crystal display device 145 is a liquid crystal display unit 145 for displaying characters to inform the user of the operation to be performed and to give a warning / message to the operation result.
A and the operation contents that are displayed as characters by the liquid crystal display unit 145A are sequentially illustrated and displayed, and the failure location and the failure content such as the master 22 in the stencil printing apparatus 200 or the master 22 that has already made a plate and the jam of the printing paper P are displayed. And an auxiliary display unit 145B for performing the operation.

Next, referring to FIG. 9, the stencil printing machine 200
The main control configuration of will be described. The control device 90 includes a plurality of microcomputers, a CPU (central processing unit) 91, an I / O (input / output) port (not shown), and a ROM (read-only storage device) 92, R.
It has an AM (readable / writable storage device) 93 and the like, and is connected by a signal bus (not shown).

The CPU 91 of the control device 90 uses the image processing device 89, the plate feeding position detection sensor 13, the home position detection sensor 14, and the home position sensor 135 via various input circuits such as a sensor input circuit and the input port.
Also, the encoder sensor 152, the double-sided printing setting key 143 and the plate making start key 141 of the operation panel 140.
Etc. are electrically connected to each other. Output signals from these, such as on / off signals and data signals, are output by the CPU.
It is input to 91.

The CPU 91 of the controller 90 controls the operation panel 1 via various drive circuits (not shown) and the output ports.
40 double-sided printing mode display device 143A and other various display devices or liquid crystal display device 14 omitted in FIG.
5, the ADF drive unit 71A and the scanner drive unit 80A of the document reading device 70, and the thermal head drive circuit 26A of the plate making / plate drive unit 39.
6, the master conveyance motor 30 via the master conveyance motor drive circuit 30A, the main motor 17 via the main motor drive circuit 17A in the plate feed printing drive unit 16, and the pressing force via the pressing force variable motor drive circuit 131A. A variable motor 131, a plate discharge drive unit 56, a paper feed drive unit 46,
The paper ejection drive unit 67 is electrically connected to each. C
The PU 91 outputs various command signals to the various display devices, the liquid crystal display device 145, or the various drive units to start, stop, and operate timing of the controlled object drive portion in each of the devices and units of the stencil printing apparatus 200. It controls the system for the entire operation.

First, the CPU 91 of the control device 90 (hereinafter sometimes simply referred to as "control device 90") moves in the master carrying direction X2 of the master 22 in accordance with the image signal input from the image processing device 89. In order to form the front side plate making image in the front side plate making image area 23 and the back side plate making image area 24 respectively,
The plate-making plate driving unit 39 of the plate-making plate feeding unit 20 (the thermal head 26 via the thermal head driving circuit 26A,
It has a basic function of controlling the master carry motor 30) via the master carry motor drive circuit 30A. More specifically, the above function is shared by the CPU of the plate making control device in the control device 90.

Secondly, the control device 90 includes the operation panel 14
0 double-sided printing setting key 143 and plate making start key 1
Based on the output signal relating to the duplex printing mode setting from 41 and the plate-making start signal, as shown in FIG. 7, the back-side plate-making image area 24 and the front side in the plate-making master 22 along the rotation direction A of the plate cylinder 1 The relevant data for forming the plate-less region length L25 corresponding to the pressing force switching time required to change the pressing force of the transfer cylinder 9 with respect to the plate cylinder 1 is selected from the ROM 92 with the plate-making image area 23. hand,
The plate-making plate driving unit 39 of the plate-making plate feeding unit 20 (the thermal head 26 via the thermal head driving circuit 26A,
It has a function as a control means for controlling the master carry motor 30) via the master carry motor drive circuit 30A.

Thirdly, the control device 90 refers to the output signals from the plate feed position detection sensor 13, the home position detection sensor 14, the encoder sensor 152, and the home position sensor 135, while referring to the output signals from the plate cylinder 1 Master 2
At the rotational position of the plate cylinder 1 corresponding to the plateless region 25 of No. 2, as shown in FIG.
It has a function as a control means for controlling the plate feed printing drive unit 16 (pressing force variable motor 131 via the pressing force variable motor drive circuit 131A) of the printing plate cylinder device 15 so as to switch to 2.

The stencil printing device 2 described later is stored in the ROM 92.
ON / OFF of the thermal head 26 relating to the program for executing the operation 00, the back side plate-making image area length L24, the front side plate-making image area length L23, and the plate-less area length L25 when making the master 22. Relationship data between the OFF heat generation drive timing and the number of pulses for driving the master conveyance motor 30 (conveyance distance of the master 22), the plate-free area of the master 22 on the plate cylinder 1 when performing double-sided printing At the rotational position of the plate cylinder 1 corresponding to 25, the rotational position of the plate cylinder 1 and the pressing force variable motor 131 for switching from the transfer pressing force F1 to the printing pressing force F2 with the pressing force as shown in FIG. 7, for example. The related data and the like relating to the number of steps (pressing force value) are stored in advance. The above-mentioned programs and related data are set to the ROM 92 in advance by data, or by replacing the ROM chip, or P
I go to ROM. As mentioned above, the ROM 92 is
It has a function as a storage unit that stores in advance the above-mentioned relational data relating to a predetermined length of the plate-less region 25 (for example, plate-less region length L25 shown in FIG. 7). RAM93 is a CPU
The calculation result in 91 is temporarily stored, and the ON / OFF signals and data signals input from the sensors and keys are stored as needed.

Hereinafter, the overall operation of the stencil printing apparatus 200 performed under the command of the control device 90 will be described while using each operation shown in FIGS. 1, 3, 10 to 12 and the like together. 1, FIG. 3, FIG. 10 to FIG. 12, etc., the thickness of the supporting cylinder 2A of the plate cylinder 1 and the master 22 and the thickness of FIG.
The thickness of the ink layer of the back side ink image 19 on the transfer cylinder 9, which is indicated by a thick line in FIGS. 0 to 12, is enlarged and exaggerated. Further, the lengths of the front side plate-making image area 23 and the back side plate-making image area 24 in the plate-making master 22 on the plate cylinder 1 are shown in a simplified manner, and are exactly as shown in FIG. 7.

In describing the operation of the controlled object drive part in each drive part, the time when each controlled object drive part is driven may be restated as "on" and the time when the drive is stopped may be restated as "off". . In addition, after the ON / OFF operation by each control target drive part is described once, the description of the ON / OFF operation by the control target drive part may be omitted for the sake of simplification and avoiding redundant description. is there.

In the initial state of the stencil printing apparatus 200, in FIG. 1, the position where the clamper 4 of the plate cylinder 1 is substantially right below is the home position of the plate cylinder 1, and the recess 11 of the transfer cylinder 9 is at the home position. The position is substantially right above the position of the clamper 4 of 1. Hereinafter, in order to simplify the description of the operation, both the back side document 74 and the front side print image and the back side print image to be printed corresponding to the front side document 74 will be described as being character images.

(Operation Example 1) First, A of the document reading device 70
An operation example 1 when double-sided printing is performed using the DF unit 71 will be described. In FIG. 1, first, when the user presses the double-sided print setting key 143 on the operation panel 140, an output signal related to the double-sided print mode setting is transmitted to the control device 90. As a result, the control device 90 recognizes that the operation related to the double-sided print mode setting is performed and recognizes that the double-sided print mode display 1
Turn on 43A. At the same time, the liquid crystal display unit 14
5A includes, for example, "a document receiving tray 72 and a back document 74
Place the original 74 for the front side on the lower side and the image side on the lower side for setting. After that, press the plate making start key 141. Is displayed, the user performs the document setting operation and the key operation as they are. Further, when there is no print paper P on the paper feed tray 41 or when the print paper P is less than the number of prints to be printed,
Since a display to that effect is displayed on the liquid crystal display unit 145A or the auxiliary display unit 145B, the printing paper P is replenished and set while appropriately checking those displays.

Next, when the user presses the plate making start key 141, a plate making start signal is generated and transmitted to the control device 90. As a result, a series of operations from plate ejection to sheet ejection is automatically performed. First, the plate making operation is performed in parallel with the plate discharging operation. Prior to this, the raising / lowering motor is turned on to raise the paper feed tray 41, so that the uppermost printing paper P contacts the paper feed roller 42. As a result, the control device 90 indicates that the uppermost printing paper P is ready to be fed by the ON detection of the feeding position detection sensor (not shown).
When the judgment is made, the paper feed unit 40 enters the paper feed standby state.

First, the plate discharge operation is performed. The plate cylinder 1 having the used master 22 of the previous plate wound around the outer peripheral surface and occupying the home position starts to rotate in the rotation direction A when the main motor 17 is turned on. As a result, the home position detection sensor 14 generates an off signal, and this off signal is transmitted to the control device 90. The control device 90 drives and controls the main motor 17 based on the OFF signal from the home position detection sensor 14 so that the plate cylinder 1 stops at the plate ejection position. During the plate discharge and plate making / plate feeding operations, the solenoid 124 of the plate feeding printing drive unit 16 is in the OFF state, and the printing cylinder 1 is separated from the outer peripheral surface of the plate cylinder 1 in the printing pressure released state. And the transfer cylinder 9 rotates.

Since the main motor 17 is turned off,
When the plate cylinder 1 stops at the plate ejection position, the opening / closing operation of the clamper 4 for preparation for the plate ejection operation starts immediately. The clamper 4 is opened by turning on the clamper motor. When the plate discharge motor of the plate discharge unit 50 is turned on, the plate separation roller pairs 51a, 51
While b is rotating, one of the plate discharge peeling roller 51b side scoops up the rear end portion of the used master 22 on the outer peripheral surface of the plate cylinder 1 by the operation of the moving means, and the plate discharge peeling roller pair 51.
The used master 22 sandwiched by a and 51b is
The used master 22 is conveyed and discharged toward the plate discharge box 54 by the plate discharge conveyance belt pair 52a and 52b, and the used master 22 is used as the plate cylinder 1.
The plate is completely peeled off from the outer peripheral surface, and the plate discharging process is completed.
At this time, the plate cylinder 1 is rotating in the counterclockwise direction (direction opposite to the rotation direction A). The used master 22 discharged to the plate discharge box 54 is then compressed inside the plate discharge box 54 through the lifting and lowering operation of the compression plate 55 when the compression plate drive motor is turned on.

On the other hand, in parallel with the movement of the plate cylinder 1 to the plate ejection position and the plate ejection operation, at the same time as the image reading operation of the document 74 is performed in the document reading device 70, the plate making operation in the plate making plate feeding unit 20. Will start. ADF drive unit 71A
2 is set on the document receiving tray 72 by driving
While the lower back original 74 of the originals 74 is automatically conveyed to a fixed position on the contact glass 86, the image of the rear original 74 is read by the original scanning optical system, and the image sensor 85 is read. The electric signal photoelectrically converted by is input to the A / D converter 88 shown in FIG. The original 74 for the back side from which the image has been read is discharged onto the original discharge tray 79. At this time, the document transport motor of the ADF drive unit 71A is turned on, and the pair of rear transport rollers 78
The a, 78b and the front transport rollers 77a, 77b are set at a document feed speed corresponding to the plate-making feed speed at which the plate-finished master 22 is transported by the rotation of the platen roller 27 by the ON-drive of the master transport motor 30 described later. The original document 74 for the back side is rotated and controlled so that the original document conveyance direction X1
Be transported to.

On the other hand, in parallel with the image reading operation of the backside document 74, various processing is performed by the A / D conversion device 88 and the image processing device 89, and whether the image data is for the front side or the image data for the backside. It is input to the plate making control device in the control device 90 as image identification data for identifying whether it exists. In the first embodiment, the plate making control device in the control device 90 determines that the image data is for the back side based on the image reading result of the document 74 for the back side. And
The heating element 26a of the thermal head 26 is selectively driven to generate heat by the thermal head drive circuit 26A in response to a digital image signal sent via the plate making control device in the control device 90 based on this, and the platen Roller 27
On the other hand, the portion of the thermoplastic resin film of the master 22 that is pressed by the thermal head 26 is selectively heated and melted to be punched, and as shown in FIG.
Is turned on, the platen roller 27 and the feed roller pair 37a, 37b rotate in the directions of the arrows in the figure, respectively, and the master 22 which has been perforated and plate-made is guided by the first guide plate 28 while being conveyed. Direction X2
Is transported to the downstream side. At this time, the electromagnetic clutch remains off, and the rotational driving force of the master conveyance motor 30 is not transmitted to the plate feed roller pair 38a, 38b.

Simultaneously with this, the suction fan motor is turned on and the suction fan 34 is rotated, so that the master 22 which has been prepressed is generated along the shape of the bending box 32 by the rotation of the suction fan 34. In the drawing, the airflow directed rightward is guided to the inside of the bending box 32 so as to hang down from the opening 32a while being bent. In this way, the plate-finished master 22 on which the back plate-making image is formed is stored in the bending box 32 as shown by the solid line. While the plate making operation is being performed, as shown in FIG. 3, the plate cylinder 1 rotates in the rotation direction A and stops at the plate feeding position shown in FIG. Then, the clamper 4 is expanded as shown by the chain double-dashed line in the figure, and the plate cylinder 1 is in the plate supply standby state.

When the image reading operation of the back side original 74 is completed, the back side plate making image (not shown) is formed in the plate making plate feeding unit 20 in the plateless state without perforating plate making as described below. Further, an operation peculiar to the present invention is carried out, in which the master 22 which has been prepressed is transported to the downstream side in the master transport direction X2 by a predetermined length. That is, in the master-made master 22 on which the above-mentioned back-side plate-making image is formed according to the image information of the back-side document 74, the upstream side in the master transport direction X2 of the back-side plate-making image area 24 (the rear part of the plate-making master 22). 7), the thermal head 26 performs perforation plate making in order to form the plate-making region length L25 shown in FIG. 7 corresponding to the pressing force switching time required for changing the pressing force of the transfer drum 9 with respect to the plate drum 1. At the same time that the thermal head drive circuit 26A is controlled so that the master plate conveyance motor 30 is rotated by the number of pulses (or the number of steps) corresponding to the plate-making region length L25, that is, the plate-making region length Master 22 that has been engraved for 25 minutes
The number of pulses for driving the master carry motor 30 so as to carry the paper to the downstream side in the master carry direction X2 is transmitted to the master carry motor drive circuit 30A. From the above, it should be noted that the plate-less area length L25 does not belong to the blank area of the unmade plate corresponding to the simple margin length of the original document 74 as in the conventional case.

When the controller 90 determines that the plate-making area 25 having the plate-making area length L25 is formed on the rear side of the back-side plate-making image area 24 by the control unit 90, the liquid crystal display section 145A displays the plate-making area 25. For example, "the front side document 74
Image is read, so the plate making start key 14
Please press 1. Is displayed, the user performs the key operation as it is.

On the other hand, in parallel with the image reading operation of the front-side original 74, the plate making operation according to the digital image signal of the front-side original 74 is performed similarly to that of the back-side original 74, as shown in FIG. As shown in the bending box 32, the master 2 having the plate-making process in which the plate-making image for surface (not shown) is formed.
As indicated by the double-dashed line, 2 is stored while gradually increasing the storage amount.

Next, in FIG. 3, the plate feeding operation is started. First, when the electromagnetic clutch is turned on, the rotational driving force of the master conveyance motor 30 is transmitted to the plate feed roller pairs 38a and 38b via the rotation transmission means, and the plate feed roller pairs 38a and 38b are indicated by broken line arrows. By such rotation, the leading end of the plate-finished master 22 shown by the broken line is conveyed to the clamper 4 which is expanded while being guided by the second guide plate 29. When the control device 90 determines that the leading end of the master 22 which has been prepressed has reached the clamper 4 due to the ON operation of the master conveyance motor 30 for a predetermined number of pulses, the clamper motor is turned off and the clamper 4 is turned off.
Is closed, so that the leading end of the master 22 that has been prepressed is locked by the clamper 4. At this time, since the electromagnetic clutch is turned off on the plate making and feeding unit 20 side,
The operation of the plate feed roller pair 38a, 38b is stopped.

Next, from the state shown in FIG. 3, a plate feeding operation is performed in which the plate-finished master is wound around the outer peripheral surface of the plate cylinder 1. When the main motor 17 is turned on, the plate cylinder 1 is rotated in the rotation direction A, and the rotational force of the plate cylinder 1 causes the plate feed roller pairs 38 a and 38 b to rotate together and is stored in the bending box 32. The master 22 that has been prepressed is pulled out and wound around the outer peripheral surface of the plate cylinder 1.
At this time, since the plate-making master 22 supplied to the outer peripheral surface of the plate cylinder 1 is applied with a load due to the rotation of the plate supply roller pairs 38a and 38b, a predetermined tension acts and wrinkles and the like are generated. It is wound around the outer peripheral surface of the plate cylinder 1 without being generated.

As the plate making operation proceeds, the master transport motor 30
The number of pulses to the master transport motor 30, that is, the number of pulses for rotating the master transport motor 30 (the number of steps of the master transport motor 30) is counted to form the above-mentioned front side plate-making image corresponding to the front side document 74, and double-sided printing is performed. When the control device 90 determines that the master 22 for which one plate has been prepressed at the time of mode setting has been prepressed, the master transport motor 30 and the suction fan motor are turned off by a command from the control device 90. As a result, the rotations of the platen roller 27, the pair of feed rollers 37a and 37b, and the suction fan 34 are stopped, and the plate making operation ends.
At this time, the amount of flexure of the master 22 made by the master stock means 31 is gradually reduced, and when the amount of flexure of the master 22 made by platemaking is minimized, the cutter motor is turned on and the cutter unit is turned on. 36
Is moved while being rotated in the width direction of the plate-made master 22, and the rear end of the plate-made master 22 is cut. Then, the cutter motor is turned off and the operation of the cutter unit 36 is stopped. In this way, the cutting timing of the rear end of the master 22 that has been plate-made by the cutter unit 36 is
It is set when the amount of flexure of the master 22 that has been prepressed is minimum. As shown in FIG. 1, when the master 22 for which one plate has been made is completely wound around the outer peripheral surface of the plate cylinder 1,
The plate feeding operation ends.

Immediately thereafter, the master 22 which has been prepressed is brought into close contact with the outer peripheral surface of the plate cylinder 1 by the adhesive force of the ink so that the ink supplied from the ink supply roller 6 inside the plate cylinder 1 can be normally exuded. The versioning operation is performed. This printing operation is performed by the master 2 on the plate cylinder 1
2 is continuously performed over three areas corresponding to the backside plate-making image area 24, the non-platemaking area 25 and the front-side platemaking image area 23. The plate-making operation for the back-side plate-making image area 24 and the non-plate-making area 25 in the plate-making master 22 is different from the conventional plate-making printing operation in which the printing paper P is fed and is not supplied. It is done in paper form. In the plate-making operation, the rotation speed of the plate cylinder 1 is set to, for example, 16 to 2.
It is performed at an ultra-low speed such as 0 rpm.

First, the solenoid 1 of the plate supply printing drive unit 16
When 24 is turned on, the printing pressure release state of the transfer drum 9 with respect to the plate cylinder 1 is released, and the printing pressure of the transfer drum 9 with respect to the plate cylinder 1 is regularly turned on / off by the rotation of the transfer drum displacement cam 126. It is said that Further, the control device 90 controls the pressing force variable motor 131 of the plate supply printing drive unit 16 so as to have the transfer pressing force F1 as shown in FIG.

When the main motor 17 is turned on,
As shown in FIG. 1, the plate cylinder 1 rotates in the rotation direction A, and the transfer cylinder 9 rotates in the rotation direction B at the same peripheral speed as the peripheral speed of the plate cylinder 1. Then, when the clamper 4 arrangement portion of the plate cylinder 1 and the recessed portion 11 of the transfer cylinder 9 have passed the rotational position where they oppose each other, that is, the master 2 on which the plate has been made on the plate cylinder 1 shown in FIG.
2 at the rotational position of the plate cylinder 1 corresponding to the front end margin of the back side plate-making image area 24, the outer circumference of the transfer cylinder 9 is caused by the transfer pressing force F1 which is the urging force of the tension spring 127 through the operation of the contacting / separating means 120. The portion 9a is pressed against the outer peripheral surface of the plate cylinder 1.

At this time, on the inner peripheral side of the plate cylinder 1, ink is supplied from the ink supply pipe 3 also serving as a support shaft to the ink reservoir 8 formed between the ink supply roller 6 and the doctor roller 7, and the plate cylinder 1 1 is rotated in the same direction as the rotation direction A of the plate cylinder 1 and in synchronism with the rotation speed of the plate cylinder 1 by the ink supply roller 6 which is in contact with the inner peripheral surface of the plate cylinder 1, so that the ink is applied to the inner circumference of the support cylinder 2A of the plate cylinder 1. Supplied to the side.

As shown in FIG. 10, the ink supply roller 6
The ink supplied to the inner peripheral side of the supporting cylindrical body 2A by
The back side plate making of the back side plate making image area 24 in the master 22 which has passed through a large number of openings 2a of the supporting cylinder 2A in the plate cylinder 1 shown in FIG. 3 and a mesh-shaped opening portion of the mesh screen 2B. After passing through the perforation pattern of the image, it is attached and transferred to the surface of the outer peripheral portion 9a (the surface of the silicone rubber layer) of the transfer cylinder 9 that is in contact with and pressed against the surface of the master 22 that has been prepressed. On the surface of the outer peripheral portion 9a, a back surface ink image 19 as shown by a thick line is formed.

Since the diameter ratio between the plate cylinder 1 and the transfer cylinder 9 is 2: 1, as shown in FIGS. 1 to 11, the transfer cylinder 9 rotates one revolution while the plate cylinder 1 rotates one half. Therefore, during this rotation, the back side plate-making image in the back side plate-making image area 24 in the first half of the plate-making master 22 is transferred to the surface of the outer peripheral portion 9a of the transfer cylinder 9 as the back side ink image 19. It should be noted that the rotational positions of the plate cylinder 1 and the transfer drum 9 shown in FIG. 11 are slightly advanced to the leading side in the rotational directions A and B relative to that shown in FIG. The state where the clamper 12 occupies the paper gripping position is shown.

As shown in FIG. 11, according to the present invention, the pressing force of the transfer cylinder 9 against the plate cylinder 1 is changed at the rotational position of the plate cylinder 1 corresponding to the plateless area 25 of the master 22 on the plate cylinder 1. The operation peculiar to is performed. That is, the control device 90
Corresponds to the plate-making area 25 of the plate-finished master 22 on the plate cylinder 1 while referring to the output signals from the plate supply position detection sensor 13, the home position detection sensor 14, the encoder sensor 152, and the home position sensor 135. At the rotational position of the plate cylinder 1, the plate feeding printing drive unit 1 is configured to switch from the transfer pressing force F1 shown in FIG. 7 to the printing pressing force F2.
The pressing force variable motor 131 is controlled via the pressing force variable motor drive circuit 131A.

On the other hand, while the back side ink image 19 is being formed on the transfer cylinder 9, in the paper feeding unit 40, the paper feeding motor is turned on and the paper feeding roller 42 and the separation roller 4 are turned on.
By rotating 3a, a pair of separation rollers 43a,
Only the uppermost one printing sheet P of the paper feed tray 41 is separated and fed by the cooperation of 43b.
Is abutted against the nip portion of the pair of registration rollers 44a and 44b. As shown in FIG. 11, the feeding amount of the printing paper P at this time is such that the front end of the printing paper P is abutted against the nip portion of the registration roller pair 44a and 44b, and a predetermined amount of curved flexure as shown by a broken line is generated. As it is formed
This is done by rotating the paper feed motor a predetermined number of steps. By turning off the paper feed motor and stopping the rotation of the paper feed roller 42 and the separation roller 43a, the leading edge of the printing paper P is brought into contact with and held by the nip portion of the registration roller pair 44a, 44b, and printing is performed. The rear end of the sheet P is brought into contact with and held by the sheet feeding roller 42 and the pair of separating rollers 43a and 43b.

In the printing plate cylinder device 15, as shown in FIG. 11, the paper feed operation is started in synchronization with the rotational movement operation immediately before the plate cylinder 1 occupies the home position. When the registration motor is turned on, the printing paper P is fed by the registration rollers 44a and 44b at a predetermined timing synchronized with the rotation of the plate cylinder 1, and is fed. Is expanded, and Fig. 11
As shown in, the paper clamper 12 is closed immediately after the front end of the printing paper P is abutted against the paper clamper 12, so that the paper clamper 12 holds the front end of the printing paper P. The leading edge of the printing paper P is nipped by the paper clamper 12.
As shown in FIG. 11, the transfer drum 9 is rotated while the printing paper P is held on the outer peripheral surface of the transfer drum 9, and the plate drum 1 is rotated.
The printing paper P is sent to the nip portion between the transfer cylinder 9 and the transfer cylinder 9. The details of the paper feeding operation are performed in the same manner as the operation described in Japanese Patent Application Laid-Open No. 11-309934 proposed by the applicant of the present application, for example.

The nip portion between the outer peripheral surface of the plate cylinder 1 and the outer peripheral portion 9a of the transfer cylinder 9 is pressed by the pressing force F2 during printing, which is the urging force of the tension spring 127 of the contacting / separating means 120. As a result, the surface of the printing paper P is pressed by the surface plate-making image (not shown) in the surface plate-making image area 23 of the plate-making master 22 on the plate cylinder 1, so that the ink supply roller 6 causes The ink supplied to the inner peripheral surface of the plate cylinder 1 passes through the perforated portion of the master 22 on which the plate has been made, and oozes out, and the bleeding ink is transferred to the surface of the printing paper P to form a surface print image. At the same time, on the back surface of the printing paper P, the back surface ink image 19 that has already been transferred onto the surface of the outer peripheral portion 9a of the transfer cylinder 9 is retransferred to the back surface of the printing paper P, and the back surface printing image is formed. It is formed. Thus
Both sides of the printing paper P are simultaneously subjected to plate-making and double-sided printing. When the printing paper P is fed to the nip portion between the plate cylinder 1 and the transfer cylinder 9 and the pressing force F2 at the time of printing is applied, the registration motor is off, and the printing paper P is conveyed by the main motor. It is made by the rotational driving force of 17.

In the printed printing paper P on which the front side print image and the back side print image are formed, the transfer cylinder 9 rotates and the paper clamper 12 is placed in front of the upper and lower 62a and 62b of the paper discharge peeling claw. By opening, the paper ejection peeling claw top / bottom 62
The sheet is separated by a and 62b, and is discharged onto the conveyor belt 65 while being sucked by the suction fan 66 through the operation of the sheet discharge driving unit 67. The printed printing paper P on the conveyance belt 65 is conveyed by the rotation of the suction paper ejection outlet roller 64 while being sucked onto the conveyance belt 65 by the suction fan 66, and is ejected onto the paper ejection tray 61 to perform double-sided printing with printing. Ends. After the printing on both sides of the plate is completed, the plate supply printing drive unit 1
When the solenoid 124 of No. 6 is turned off, the transfer cylinder displacement cam 126 is operated, and the outer peripheral portion 9a of the transfer cylinder 9 is moved to the plate cylinder 1.
Is separated from the outer peripheral surface of. The plate cylinder 1 is rotationally moved to the home position and stopped at the home position.

On the other hand, on the transfer cylinder 9 side, the transfer cylinder 9 is shown in FIG.
At the rotational position further rotated to the downstream side (advance side) in the rotational direction B from the rotational position shown in FIG. 2, the cleaning unit 100 shown in FIG. 1 performs the two-stage cleaning as described above. When the transfer cylinder 9 prints with the same master 22, every time the printing with the back surface ink image 19 formed by the ink transferred from the back surface plate-making image of the plate-making master 22 on the plate cylinder 1 is completed. Alternatively, the surface of the outer peripheral portion 9a is cleaned by the cleaning unit 100 every predetermined number of times of printing. Further, regarding the cleaning, when the printing process by the new master 22 is performed, it is needless to say that the cleaning process is performed at the previous stage, that is, when the final printing by the master 22 in the previous stage is completed.

On the other hand, in FIG. 3, the plate making and feeding unit 2
At 0, the guide transport plate 33 moves from the deflection forming position shown in FIG. 3 and lies between the vicinity of the lower part of the nip portion of the feed roller pairs 37a and 37b and the vicinity of the lower part of the nip portion of the plate feeding roller pairs 38a and 38b. Do not occupy the guide transport position. At the same time, the master transport motor 30 is turned on, so that the platen roller 27 and the feed roller pair 37 are
a, 37b are rotated, the electromagnetic clutch is turned on, and the plate feed roller pair 38a, 38b is rotated, so that the tip of the master 22 of the next plate, which is cut by the cutter unit 36, is fed by the feed roller. Pair 37a, 37
While being guided by the guide transport plate 33 and the second guide plate 29 while being transported by the rotation operation of the b and the plate feed roller pair 38a, 38b, they are transported downstream in the master transport direction X2. Then, when it is determined that the leading end of the master 22 of the next plate, which has been plate-formed, has occupied the plate-making standby position shown by the solid line in FIG. This stops the rotations of the platen roller 27, the feed roller pairs 37a and 37b, and the plate feed roller pairs 38a and 38b.

Next, when the user sets the number of prints with the ten keys 144 of the operation panel 140 and presses the plate making start key 141 again, a print start signal is transmitted to the control device 90, and the plate making operation and the plate making both sides are performed. In the same operation as the printing operation, each operation of paper feeding, printing and paper ejection is repeatedly performed for the set number of printed sheets, and all operations of the regular double-sided printing are completed.

The printing paper P used in the printing on both sides of printing is not counted as the regular number of printed sheets. The regular double-sided printing operation is performed at the set print speed set by the user with the print speed setting key 146 (speed down key 146a and speed up key 146b) or by the user, as compared with the above-mentioned plate-forming operation and the above-mentioned plate-forming double-sided printing operation. Does not operate the print speed setting key 146, it is different in that double-sided printing is performed at the standard print speed and that the paper feed operation and the paper discharge operation are performed at a speed corresponding to the set print speed. Only.

(Operation Example 2) Next, the back glass original 74 indicated by the alternate long and two short dashes line on the contact glass 86 of the original reading device 70.
A second operation example in which double-sided printing is performed through the operation of sequentially placing the front surface original 74 will be described. The operation example 2 is different from the operation example 1 in that the backside document 74 is set on the contact glass 86, the image is read and the plate making operation is performed, and then the front side document 74 is set. The main difference is that image reading and plate making operations are performed. Hereinafter, a brief description will be given focusing on the different points.

In FIG. 1, first, when the user presses the double-sided print setting key 143 on the operation panel 140, an output signal relating to the double-sided print mode setting is transmitted to the control device 90 as in the operation example 1, and The control device 90 recognizes that the operation related to the double-sided printing mode setting is performed, and turns on the double-sided printing mode indicator 143A. At the same time, the liquid crystal display 145A displays "Please place and set the back side original 74 on the contact glass 86 with the image side down. After that, press the plate making start key 141." Is displayed, the user performs original document setting operation and key operation as they are. Below, operation example 1
Similarly, when the user presses the plate making start key 141,
A plate-making start signal is generated and transmitted to the control device 90, so that a series of operations from plate ejection to sheet ejection is automatically performed. First, in parallel with the plate discharging operation, the plate making operation is performed in the same manner as in the operation example 1.

The image reading operation of the back side document 74 is as follows.
The image of the backside document 74 placed and set at a fixed position on the contact glass 86 is read by the document scanning optical system of the scanner section 80, and thereafter, the same operation as in the operation example 1 is performed. When the image reading operation of the back side original 74 is completed, in the plate making plate feeding unit 20, as in the operation example 1, the plate making area 25 corresponding to the plate making area length L25 is provided on the rear side of the back plate making image area 24. It is formed on the master 22 that has been prepressed. When the control device 90 determines that the plate-making area 25 is formed on the master 22 that has been plate-formed, the liquid crystal display 145A displays, for example, "Because the image of the original 74 for the front side is read, the contact glass 86, Place and set the front side document 74 with the image side facing down. After that, press the plate making start key 141. "is displayed. I do. Below, operation example 1
The same operation is performed.

Therefore, according to the first embodiment, the first
In addition, the basic configuration of the conventional one-plate cylinder split transfer cylinder one-pass double-sided printing system, that is, one plate cylinder, one transfer cylinder, and one plate making unit and one plate discharge unit Since it is possible to perform simultaneous printing on both sides of the printing paper using, the same effects as the conventional one can be achieved such as cost reduction by reducing the number of parts and downsizing of the device, and the following effects peculiar to this embodiment. Play. Secondly, the plate cylinder 1 in the master 22 that has been prepressed
Between the back side plate-making image area 24 and the front side plate-making image area 23 along the rotation direction A of a predetermined length corresponding to the pressing force switching time required to change the pressing force of the transfer cylinder 9 to the plate cylinder 1. By forming the plateless region 25, it is possible to prevent image density unevenness that occurs between the front side print image and the back side print image.

Thirdly, the pressing force F1 at the time of transfer of the transfer cylinder 9 to the plate cylinder 1 at the time of transferring the back side plate-making image by the pressing force varying means 130 and the printing pressure of the transfer cylinder 9 to the plate cylinder 1 at the time of double-sided printing. By changing to the pressing force F2, that is, by making the pressing force F1 at the time of transfer and the pressing force F2 at the time of printing different, the image density difference generated between the front side print image and the back side print image is reduced. can do.

Fourth, the transfer pressing force F1 of the transfer cylinder 9 against the plate cylinder 1 at the time of transferring the back side plate-making image and the printing pressing force F of the transfer cylinder 9 against the plate cylinder 1 at the time of double-sided printing.
The second effect can be easily obtained by changing 2 and 2 by the rotational position of the plate cylinder 1 corresponding to the plate-making area 25 of the master 22 that has already made the plate. Fifthly, the aperture ratio of the mesh screen 2B in the back side printing area 118 is determined by the front side printing area 117.
Is set larger than that, and the switching position of the aperture ratio corresponds to the plate-making area 25 of the plate-making master 22 wound on the mesh screen 2B. Since the degree of freedom in design is large and it can be changed relatively easily as compared with the case of changing the opening density or the opening ratio of the cylindrical body 2A, the third effect can be obtained more easily.

Sixth, since the transfer drum 9 is provided with the paper clamper 12 that holds the leading end of the fed printing paper P, the leading end of the printing paper P is abutted against the paper clamper 12 to feed the paper. As a result, the printing resist accuracy for the printing paper P can be improved, and the distance between the outer peripheral surface of the plate cylinder 1 and the outer peripheral surface 9a of the transfer drum 9 is set to about 2 mm, which is very small. It is also possible to reduce the noise of time.

As described above, the mesh screen 2B
Is not always necessary, and may not be wound around the outer peripheral surface of the support cylindrical body 2A depending on printing conditions (see claims 1 to 3). When the mesh screen 2B is removed from the configuration of the plate cylinder 1 of the first embodiment, in order to obtain the same effect as the second effect, the pressing force at the time of transfer by the pressing force varying unit 130 is generally used. It can be said that it is necessary to make the amount of change between F1 and the pressing force F2 during printing larger than in the example shown in FIG. 7, for example. This is
The same can be said for modified examples 1 to 3 described later.

If it is not necessary to adjust the amount of ink passing through the plate cylinder 1 by changing the aperture ratio of the mesh screen 2B, the aperture 2a of the support cylinder 2A shown in FIG. Density change (when the aperture diameter of the aperture 2a is the same, the ink passage amount is changed by changing the aperture area per unit area in the printable area of the support cylinder 2A), and the support cylinder 2A Change in aperture ratio (when the aperture density is the same, aperture 2a1
The amount of ink passing can be changed by changing the aperture size per piece). That is, the opening density and the aperture ratio of the back side printing area 118 are set to the front side printing area 117.
And the switching positions of the aperture density and the aperture ratio are set to correspond to the plate-making area 25 of the plate-making master 22 wound around the supporting cylinder 1A and the mesh screen 2B. It may be formed. This can be said also in Modifications 1 to 3 described later.

The embodiment of the present invention is not limited to the first embodiment, and the unique plate-making area 25 as in the present invention is not disclosed, for example, the one-plate cylinder disclosed in JP-A-10-129100. In the split transfer cylinder 1-pass double-sided printing configuration, the configuration (including control) having only the pressing force varying means 130 may be used (see the first technical configuration in the means for solving the problem). Such Embodiment 1
The operation of the stencil printing apparatus according to the first technical configuration, which is not limited to the above, can be easily performed from the above-described operation examples 1 and 2, and the description thereof will be omitted.

(Modification 1 of Embodiment 1) Modification 1 of Embodiment 1 will be described. The first modification is the first embodiment.
Compared with the above, the main difference is that a control device 90A is provided instead of the control device 90. Like the control device 90, the control device 90A includes a plurality of microcomputers, a CPU 91A, an I / O (input / output) port (not shown), a ROM 92A, a RAM 93, and the like, and a signal bus (not shown). No.)).

The CPU 91A of the control device 90A (hereinafter sometimes simply referred to as "control device 90A") has a surface function in addition to the first and third functions of the control device 90 as compared with the control device 90. A perforation energy varying means for changing the perforation energy supplied to each heating element 26a of the thermal head 26 in accordance with the formation of the plate-making image (not shown) and the formation of the back-side plate-making image (not shown). Is different (hereinafter, this function is referred to as a fourth function of the control device 90A).

Further, the control device 90A replaces the second function of the control device 90 with an output signal and a plate-making start signal from the double-sided print setting key 143 and the plate-making start key 141 of the operation panel 140 for setting the double-sided printing mode. Based on the above, between the back side plate making image area 24 and the front side plate making image area 23 along the rotation direction A of the plate cylinder 1 in the plate making master 22, the pressing force switching time and the front side plate making image area 23 are provided. The plate-making area 2 corresponding to the perforation energy switching time required to change the perforation energy for perforating the master 22 according to the back-side plate-making image area 24.
The relational data for forming the length 5 is selected from the ROM 92A, and the plate making plate driving unit 3 of the plate making plate making unit 20 is selected.
9 (the thermal head 26 via the thermal head drive circuit 26A and the master transport motor 30 via the master transport motor drive circuit 30A) has a function as a control means (hereinafter, this function will be referred to as the control device 90A). 2).

The ROM 92A differs from the ROM 92 in that
In addition to the above-described functions of the ROM 92, the thermal head 26 is provided in accordance with the formation of the front side plate-making image (not shown) and the back side plate-making image (not shown) when the master 22 is made. Of the relational data relating to the energization pulse width for changing the energy for perforation to be supplied to each of the heating elements 26a, that is, "the energization time reference value of the front side plate-making image" and "the energization time reference value of the back side plate-making image". The difference is that it is determined and stored in advance by experiments or the like.

Here, for example, the relationship between the print image density in the stencil printing apparatus, the energy for perforation, and the perforation diameter of the master 22, which are basic technical matters disclosed in Japanese Patent Nos. 2756219 and 2756224, are given. , Keep it together. In a stencil printer,
The print image density is determined by the amount of ink bleeding from the master 22. The amount of ink that bleeds from the perforated portion of the master 22 is proportional to the opening area of each minute perforation that constitutes the perforation pattern formed on the master 22.

Therefore, a print image with a high print image density is obtained by enlarging individual perforations forming a perforation pattern, and conversely, a print image with a low print image density is
Obtained by reducing the individual perforations that form the perforation pattern. In other words, the perforation energy corresponding to the temperature of each heat generating portion of the thermal head 26, that is, the perforation size of the perforation pattern for obtaining the optimum print image is determined according to the desired print image density. You can

From the technical matters shown in FIG. 2 and the like of the patent publication of Japanese Patent No. 2756224, the punching pattern formed on the master 22 by the punching energy supplied to the individual heating elements 26a of the thermal head 26. The size of the perforation (perforation diameter) as one unit can be controlled. This situation is the same regardless of whether the heating element 26a is rectangular type or heat concentration type. As described above, the size of the perforation pattern is determined according to each of the print image densities, and on the other hand, the size of the perforation is determined by the energy for perforation.Therefore, there is a correspondence between the print image density and the energy for perforation. , This correspondence can be determined experimentally.

Adjustment of the energy for drilling is described in Japanese Patent No. 275.
As described in Japanese Patent No. 6219 and Japanese Patent No. 2756224, the thermal head 26 is responsive to an image signal.
Value of the current flowing through the individual heating elements 26a of the
Although it may be performed by changing the voltage value applied to a, in the first modification, it is performed by changing the energizing pulse width (energizing time) to the heating element 26a of the thermal head 26. Then, when the other plate making conditions other than the energizing pulse width (energizing time) are not changed, the energizing pulse width (energizing time) length when forming the back side plate making image in the back side plate making image area 24 is set as follows. Surface plate-making image area 23
The perforation plate making is made longer than that when forming the front side plate-making image in (1) to compensate for the decrease in the image density of the back side print image. The thermal head drive circuit 26A receives power supply from a power source (not shown) according to the image signal, and the individual heating elements 26a of the thermal head 26 according to the energization pulse width set by the controller 90A.
Heat up.

(Operational Example 3) Next, an operational example 3 of the modified example 1 will be described focusing on points different from the operational example 1. The first operation by the user, that is, the user operates the operation panel 14
0 double-sided printing setting key 143 and plate making start key 1
The operations such as discharging the plate after pressing 41 and reading the image of the backside document 74 can be easily understood and implemented by replacing the control device 90 with the control device 90A in the operation example 1, and therefore the description thereof is omitted. To do.

Whether the image data for the front side or the image data for the back side is processed by the A / D conversion device 88 and the image processing device 89 in parallel with the image reading operation for the back side document 74. Is input to the plate making control device in the control device 90A as image identification data for identifying.
In the first modification, the plate making control device in the control device 90A determines that the image data is for the back side based on the image reading result of the document 74 for the back side. At this time, the plate making control device (CPU 91A) in the control device 90A is R
The energization time reference value of the backside plate-making image is selected from the OM 92A, and the heating element 26a of the thermal head 26 selectively selects the energization time reference value of the backside plate-making image via the thermal head drive circuit 26A according to the digital image signal. It is driven by heat. Hereinafter, the same plate making operation as that in the operation example 1 is performed.

When the image reading operation of the back side original 74 is completed, in the plate making plate feeding unit 20, as described below, the back side plate making image (not shown) is formed in a plateless state without perforating plate making. Formed master 22
The operation peculiar to the present invention is carried out in which is carried to the downstream side in the master carrying direction X2 by a predetermined length. At this time, the length of the plate-less area 25 in the master 22 that has been plate-made is
It is determined corresponding to the longer one of the pressing force switching time and the perforation energy switching time in the operation example 1. However, in general, the response time delay until the heating device 26a of the thermal head 26 is controlled to generate heat within the perforation energy switching time from the control device 90A via the thermal head driving circuit 26A is the pressing force switching time. The plate-making region length L25 shown in FIG. 7 corresponding to the pressing force switching time is practically acceptable since it is negligibly small compared to the plate-making region length L25.

When the control device 90A determines that the plate-making region 25 is formed on the rear side of the back-side plate-making image region 24 by the plate-making region length L25 in the master 22 which has been plate-prepared, the liquid crystal display unit 145A shows For example, "the front side document 74
Image is read, so the plate making start key 14
Please press 1. Is displayed, the user performs the key operation as it is.

On the other hand, in parallel with the image reading operation of the front surface original 74, the plate making operation according to the digital image signal of the front surface original 74 is performed. Various processes are performed by the A / D conversion device 88 and the image processing device 89, and it is determined by the plate making control device in the control device 90A that the image data is for the front surface based on the image reading result of the original document 74 for the front surface. At this time, the plate making control device (C
The PU 91A) selects the energization time reference value of the surface plate-making image from the ROM 92A, and the thermal head 26 via the thermal head drive circuit 26A according to the digital image signal.
The heating element 26a is selectively driven to generate heat with the energization time reference value of the surface plate-making image. After that, the same plate making / plate feeding operation and plate printing operation are performed as in the operation example. The operation example of the modified example 1 corresponding to the operation example 2 of the first embodiment can be easily understood and implemented from the operation example 2 and the operation example 3 described above, and thus the description thereof will be omitted.

Therefore, according to the first modification, the same effects as the first, third, and sixth embodiments of the first embodiment are obtained, and the following effects replacing the second and third effects of the first embodiment are obtained. Play. Secondly, in order to change the pressing force of the transfer cylinder 9 to the plate cylinder 1 between the back plate-making image area 24 and the front plate-making image area 23 along the rotation direction A of the plate cylinder 1 in the plate-making master 22. Of a predetermined length corresponding to the pressing force switching time required for changing the punching energy for punching the master 22 according to the front side plate making image area 23 and the back side plate making image area 24. By forming the plate-making region 25, it is possible to prevent image density unevenness that occurs between the front side print image and the back side print image.

Thirdly, by changing the pressing force F1 at the time of transfer and the pressing force F2 at the time of printing by the pressing force changing means 130, the image density difference generated between the front side print image and the back side print image is reduced. It can be reduced. Overlapping this, the individual heating elements of the thermal head 26 are formed according to the time of forming the front plate-making image (not shown) and the back-side plate making image (not shown) by the perforation energy varying means. Since the perforation energy supplied to 26a can be changed and made different, the image density difference generated between the front side print image and the back side print image can be reduced in a more remarkable manner.

In the first modification, the prevention of the image density unevenness occurring between the front side print image and the back side print image is prevented by the pressing force varying means 130 and the perforation energy varying means.
Since the steps are performed in stages, the amount of change in the pressing force and the amount of change in the energy for punching can be performed in a relatively small range as compared with the case of using either one of the means.

The embodiment of the present invention is not limited to the first modification,
Only the pressing force varying means 130 shown in FIGS. 5 and 6 may be removed, and a combination configuration of the energy varying means for perforation (including control) and the change of the mesh screen aperture ratio may be adopted (claim 1 and (See claim 8). Alternatively, both the pressing force varying means 130 and the mesh screen aperture ratio may be removed, and only the perforation energy varying means may be configured (including control) (see claims 1 and 6). . For each of these actions,
Since it can be easily implemented from the above-described operation examples 1 to 3, the description thereof will be omitted.

Not limited to the modified example 1, the specific plateless area 25 as in the present invention is not disclosed, for example, as disclosed in Japanese Patent Laid-Open No. 10-129100.
The plate cylinder divided transfer cylinder 1-pass double-sided printing configuration may have only the perforation energy varying means (including control) (see the second technical configuration in the means for solving the problems). The operation of the stencil printing apparatus according to the second technical configuration which is not limited to the modification 1 can be easily performed from the above-described operation example 3 and the like, and thus the description thereof will be omitted.

(Modification 2 of Embodiment 1) FIGS. 9 and 1
Modification 2 of Embodiment 1 will be described with reference to FIG. This modified example 2 is different from the modified example 1 in that the plate-making master 2 wound around the plate cylinder 1 shown by a chain double-dashed line in FIG.
2. The transfer rotation speed V1 of the plate cylinder 1 during the transfer of the back side plate-making image (not shown) and the plate cylinder 1 during the double-sided printing.
9 has a main motor drive circuit 17A shown in FIG. 9 having a partial functional configuration as a rotation speed varying means for changing the printing rotation speed V2, and one of the rotation speed varying means instead of the control device 90A. The main difference is that it has a control device 90B having the function of a part and having a function of controlling the main motor 17 via the main motor drive circuit 17A.

As the main motor 17, for example, an outer rotor type DC brushless motor with a gear is preferably used from the viewpoints of life improvement, noise reduction, high efficiency and high speed response. The main motor drive circuit 17A incorporates a control circuit and the like including a dedicated IC for controlling the rotation speed (rotation speed) of the main motor 17 as the printing speed. In terms of an embodiment, this control circuit is a PW because it has almost no power loss, is energy efficient, and is economical.
An N (pulse width modulation) control method is adopted, and it has a known circuit configuration in which the duty ratio, which is the time ratio of ON and OFF of the voltage applied to the main motor 17, is changed.

With reference to FIG. 13, the relationship between the transfer rotational speed V1 and the printing rotational speed V2 will be described. Figure 1
3, the horizontal axis represents the time t corresponding to the rotation angle of the plate cylinder 1, and the vertical axis represents the printing speed (rpm) corresponding to the rotation speed of the plate cylinder 1. The relationship between the hourly rotation speed V1 and the printing rotation speed V2 is shown. In addition to the operations of the above-described operation examples 1 to 3, the plate-making master 22 already made by the plate-making plate feeding unit 20 which receives a command from the control device 90B causes the plate-making image for the back surface along the rotation direction A of the plate cylinder 1. Between the area 24 and the surface plate-making image area 23, a plate-making area 25 having a predetermined length corresponding to the rotation speed switching time required to change the rotation speed of the plate cylinder 1.
Is formed.

In the later-described operation of the second modification, when the plate cylinder 1 rotates in the rotation direction A, the back plate-making image area 24 in the plate-making master 22 on the plate cylinder 1 changes from the front plate-making image area 23 to the front plate-making image area 23. When changing, the main motor drive circuit 17A is operated by a command from the control device 90B to change the rotation speed of the plate cylinder 1.
In particular, the mechanical operation part of the above-mentioned drive mechanism including (for example, backlash of mechanical mechanism part or variation of belt tension)
Since there is a relatively large time delay due to
It is not possible to change the rotation speed of, and it takes some time to change it. Therefore, the plate-less region length L25 corresponds to the pressing force switching time required to change the pressing force of the transfer cylinder 9 with respect to the plate cylinder 1, and also the plate cylinder 1
The amount corresponding to the rotation speed switching time required to change the rotation speed of is also required. That is, in this modification 2, the pressing force F1 at the time of transfer is switched to the pressing force F2 at the time of printing at the rotational position of the plate cylinder 1 corresponding to the plate-making area 25 of the master 22 on the plate cylinder 1 which has already been plate-made. And the rotational speed V during transfer
One of the features is to switch from 1 to the rotational speed V2 during printing.

In practice, in the plateless region 25, the time t corresponding to the pressing force switching time is overlapped with the time t corresponding to the rotation speed switching time at the same time. It can be said that the plate-less region length L25 is determined by the longer one of the pressing force switching time and the rotation speed switching time (both in the case of equality).

Further, under normal plate-making printing conditions (for example, when both the front side and the back side original images are character images), the transfer rotation speed V1 is higher than the printing rotation speed V2 as shown in FIG. It is set in advance so as to be small by experiments or the like. By having such a control configuration for controlling the rotation speed varying means, the transfer rotation speed V1 is controlled to be lower than the printing rotation speed V2, and the ink passage amount in the back side plate-making image area 24 is controlled. By making it larger than that of the front side plate-making image area 23, it becomes possible to easily reduce the image density difference generated between the front side print image and the back side print image during double-sided printing.

As shown in FIG. 13, two A3 size plate-making images are taken as the front side plate-making image area 23 and the back side plate-making image area 24, and the rotation speed (printing speed) of the plate cylinder 1 is set to the maximum. 120 rpm of the plate cylinder 1 and considering the clamper 4 arrangement area of the plate cylinder 1, the diameter of the plate cylinder 1 is about 330 mm and the peripheral speed thereof is about 2073 mm.
/ sec (seconds). Further, the control system and the main motor 17 shown in FIG. 9 for changing the rotation speed of the plate cylinder 1.
In consideration of the load and the like, 0.02 to 0.05 sec is required as a response time for that. Taking all of these into consideration, the plate-less region length L25 is about 40 to 100 mm. However, the numerical range of the plate-less region length L25 is the result of the actual machine used this time as described with reference to FIG. 7, and if the response time of the control system and the main motor 17 becomes faster, the plate-less region becomes longer. It is considered that the length L25 becomes smaller.

Like the control device 90A, the control device 90B includes a plurality of microcomputers, and CP
A U91B, an I / O (input / output) port (not shown), a ROM 92B, a RAM 93, and the like are provided and are connected by a signal bus (not shown). Control device 90B
CPU 91B (hereinafter sometimes simply referred to as "control device 90B") is added to the first and fourth functions of control device 90A as compared with control device 90A, and is used for transferring the backside plate-making image. The rotational speed V1 of the plate cylinder 1 during transfer,
The plate feed printing drive unit 1 in the printing plate cylinder device 15 so as to change the printing rotation speed V2 of the plate cylinder 1 during double-sided printing.
6 (main motor 17 via the main motor drive circuit 17A) has a function as a control means for controlling (hereinafter, this function is referred to as a fifth function of the control device 90B).

Further, the control device 90B is the same as the control device 90A.
In place of the second function of the plate cylinder 1 in the master 22 which has already been made, based on the output signal relating to the double-sided print mode setting from the double-sided print setting key 143 and the plate-making start key 141 of the operation panel 140 and the plate-making start signal. Between the back side plate-making image area 24 and the front side plate-making image area 23 along the rotation direction A, the rotation speed required to change the pressing force switching time, the perforation energy switching time and the rotation speed of the plate cylinder 1. Plateless area 25 corresponding to the switching time
Relational data for forming the length of the plate making plate driving unit 39 of the plate making plate feeding unit 20.
(Controls the thermal head 26 via the thermal head drive circuit 26A, the master transport motor 30 via the master transport motor drive circuit 30A) and the plate feed printing drive unit 16 (main motor 17 via the main motor drive circuit 17A). It has a function as a control means (hereinafter, this function will be referred to as a second function of the control device 90B).

Further, the control device 90B is the same as the control device 90A.
Instead of the third function of the plate feeding position detection sensor 13, the home position detection sensor 14, the encoder sensor 15
2. Referring to the output signal from the home position sensor 135, at the rotational position of the plate cylinder 1 corresponding to the plate-making area 25 of the plate-making master 22 on the plate cylinder 1, for example, as shown in FIG. The plate feed printing drive unit 16 of the printing plate cylinder device 15 so as to switch from the hour pressing force F1 to the printing pressing force F2.
At the same time as controlling the pressing force variable motor 131 via the pressing force variable motor drive circuit 131A,
5 at the rotational position of the plate cylinder 1 such that the rotational speed V1 during transfer is switched to the rotational speed V2 during printing as shown in FIG. 13, for example, the plate feed printing drive unit 16 (via the main motor drive circuit 17A) It has a function as a control means for controlling the main motor 17) (hereinafter, this function is referred to as a third function of the control device 90B).

The ROM 92B is, in comparison with the ROM 92A, added to the above-mentioned functions of the ROM 92A to provide relational data relating to the rotational speed of the plate cylinder 1 for changing the rotational speed V1 during transfer and the rotational speed V2 during printing, that is, " The difference is that the “transfer rotational speed reference value” and the “printing rotational speed reference value” are previously determined and stored by experiments or the like.

(Operational Example 4) Next, an operational example 4 of the modified example 2 will be described focusing on points different from the operational example 3 of the modified example 1. The first operation by the user, that is, the discharge 74 of the plate after the user presses the double-sided printing setting key 143 and the plate-making start key 141 of the operation panel 140, the original 74 for the back side
In the operation example 3, the controller 90A is controlled by the controller 9A for the plate making operation performed in parallel with the image reading of
It can be easily understood and implemented by replacing it with 0B.
The description is omitted.

When the image reading operation of the back side original 74 is completed, the back side plate making image (not shown) is formed in the plate making plate feeding unit 20 in the state of no plate making without perforating plate making, as described below. Further, an operation peculiar to the present invention is carried out, in which the master 22 which has been prepressed is transported to the downstream side in the master transport direction X2 by a predetermined length. At this time, the length of the plate-making region 25 in the master 22 that has been plate-formed corresponds to the longer one of the pressing force switching time, the perforation energy switching time, and the rotation speed switching time. Decided.

When the controller 90B determines that the plate-making area 25 is formed on the master 22 which has been plate-formed by the plate-making area length L25 on the rear side of the back-side plate-making image area 24, the liquid crystal display section 145A shows For example, "the front side document 74
Image is read, so the plate making start key 14
Please press 1. Is displayed, the user performs the key operation as it is.

On the other hand, in parallel with the image reading operation of the front side document 74, a plate making operation according to the digital image signal of the front side document 74 and a plate feeding operation similar to the operation example 3 are performed in the same manner as in the operation example 3. Done. As shown in FIG. 1, the plate feeding operation is completed at the stage when one plate-made master 22 is completely wound around the outer peripheral surface of the plate cylinder 1.

Immediately thereafter, the printing operation is performed. This plate making operation is continuously performed over three areas corresponding to the back side plate making image area 24, the plate making image area 25 and the front side plate making image area 23 in the plate making master 22 on the plate cylinder 1. The plate-making operation for the back-side plate-making image area 24 and the plate-free area 25 in the plate-making completed master 22 is performed in an operation different from the operation example 3 in the non-feeding state.

First, the solenoid 1 of the plate supply printing drive unit 16
When 24 is turned on, the printing pressure release state of the transfer drum 9 with respect to the plate cylinder 1 is released, and the printing pressure of the transfer drum 9 with respect to the plate cylinder 1 is regularly turned on / off by the rotation of the transfer drum displacement cam 126. It is said that Further, the control device 90B controls the pressing force variable motor 131 so as to obtain the transfer pressing force F1 as shown in FIG. 7, and also the main motor 1 so as to obtain the transfer rotational speed V1 as shown in FIG.
7 is controlled. At this time, the rotation speed of the plate cylinder 1 during the plate-making operation for the back-side plate-making image area 24 is slower than that in the operation example 3, for example, 16 to 20 r, in the example.
It is performed at a very low speed such as pm.

By turning on the main motor 17,
As shown in FIG. 1, the plate cylinder 1 rotates in the rotational direction A at the transfer rotational speed V1, and the transfer drum 9 rotates in the rotational direction B at the same peripheral speed as the peripheral speed of the plate cylinder 1 to operate. The printing on the backside plate-making image area 24 is performed in the same manner as in Example 3.

As shown in FIG. 11, at the rotational position of the plate cylinder 1 corresponding to the plate-making area 25 of the master 22 on the plate cylinder 1, the pressing force of the transfer cylinder 9 against the plate cylinder 1 is changed at the same time. The operation peculiar to the present invention that changes the rotation speed (printing speed) of the plate cylinder 1 is performed. That is, the control device 90B
While referring to the output signals from the plate feed position detection sensor 13, the home position detection sensor 14, the encoder sensor 152, and the home position sensor 135, the plate cylinder corresponding to the plateless region 25 of the master 22 on the plate cylinder 1 which has been plate-made. At the rotation position of 1, the pressing force variable motor 131 is changed through the pressing force variable motor drive circuit 131A of the plate supply printing drive unit 16 so as to switch from the transfer pressing force F1 shown in FIG. 7 to the printing pressure force F2. Simultaneously with the control, at the rotational position of the plate cylinder 1 corresponding to the same plate-making area 25, for example, as shown in FIG. 13, the plate feeding print driving unit 16 (to switch from the transfer rotational speed V1 to the printing rotational speed V2). The main motor 17) is controlled via the main motor drive circuit 17A.

Subsequent sheet feeding preparation operations and sheet feeding operations are performed in the same manner as in the operation example 3. In the plate-making double-sided printing operation, in comparison with the rotation speed of the plate cylinder 1 at the time of plate-making with respect to the back side plate-making image area 24 in the operation example 4, as compared with the embodiment, it is more than in the case of the back side plate-making image area 24. Is also fast, for example 20 to 3
The only difference is that the operation is performed at an ultra low speed such as 0 rpm.

The printing paper P used in the printing on both sides of the plate is not counted as the regular number of prints. The regular double-sided printing operation differs from the above-mentioned plate-forming operation and the above-mentioned plate-forming double-sided printing operation only in the following points.
That is, when the back side ink image 19 is transferred from the back side plate-making image area 24 onto the transfer cylinder 9, the set print speed set by the user with the print speed setting key 146 (speed down key 146a and speed up key 146b) is exceeded. Also, the transfer is performed at the slower transfer printing speed V1 or at the transfer printing speed V1 slower than the standard printing speed when the user does not operate the printing speed setting key 146.

On the other hand, during double-sided printing (surface plate-making image area 2
For printing on the front surface of the printing paper P from No. 3 and re-transferring the ink image 19 for the back surface on the transfer cylinder 9 to the back surface of the printing paper P, the user sets the printing speed setting key 146 (speed down key 146a and At the set printing speed corresponding to the printing rotation speed V2 set by the speed up key 146b), or at the standard printing speed corresponding to the printing rotation speed V2 when the user does not operate the printing speed setting key 146, The only difference is that double-sided printing is performed and that the sheet feeding operation and the sheet discharging operation are performed at a speed corresponding to the set printing speed. The operation example of the modified example 2 corresponding to the operation example 2 of the first embodiment can be easily understood and implemented from the operation example 2 and the operation example 4 described above, and thus the description thereof will be omitted.

Therefore, according to the second modification, the same effects as those of the first, third, and sixth embodiments of the first embodiment are obtained, and the following effects replacing the second and third effects of the first modification are provided. Play. Secondly, between the plate-making image area 24 for the back surface and the plate-making image area 23 for the front surface along the rotation direction A of the plate cylinder 1 in the master 22 which has already been made, the transfer cylinder 9 for the plate cylinder 1 is formed.
Pressing force switching time required to change the pressing force of, the punching energy switching time required to change the punching energy for punching the master 22 according to the front side plate making image area 23 and the back side plate making image area 24, and the plate. By forming the plate-less region 25 of a predetermined length corresponding to the rotation speed switching time required to change the rotation speed (printing speed) of the cylinder 1, it occurs between the front side print image and the back side print image. Image density unevenness can be prevented. Thirdly, the pressing force varying unit 130 changes the pressing force F1 at the time of transfer and the pressing force F2 at the time of printing, and overlaps with this, and at the time of forming the surface plate-making image (not shown) by the energy changing unit for perforation. The energy for perforation to be supplied to each heating element 26a of the thermal head 26 is changed depending on the time of forming a backside plate-making image (not shown), and is overlapped with the rotation speed changing means for the backside. The transfer rotation speed V1 of the plate cylinder 1 at the time of transferring the plate-making image and the printing rotation speed V2 of the plate cylinder 1 at the time of double-sided printing can be changed and can be made different from each other. The image density difference generated between the image and the image can be reduced in a more remarkable manner.

In the second modification, the unevenness of the image density generated between the print image for the front side and the print image for the back side is prevented by the pressing force varying means 130, the perforating energy varying means, and the rotating speed varying means. Since it is carried out in stages, the amount of change in pressing force, the amount of energy for drilling, and the amount of change in rotational speed should be performed in a relatively small range, as compared with the case of using any one means or any two means. Will be able to.

The embodiment of the present invention is not limited to the second modification,
Even if the rotational speed varying means is combined with at least one of the pressing force varying means 130, the perforating energy varying means, and the mesh screen aperture ratio changing configuration shown in FIGS. 5 and 6. Good (see claim 1, claim 4 to claim 8).

Not only the second modification but also the pressing force varying means 13
0, the energy varying means for perforation and the configuration for changing the aperture ratio of the mesh screen may be completely removed, and only the rotational speed varying means may be configured (including control) (claims 1, 4 and 5). reference). Not limited to the second modification,
In the one-plate cylinder split transfer cylinder one-pass double-sided printing configuration disclosed in, for example, Japanese Unexamined Patent Publication No. 10-129100, which does not disclose the specific plateless area 25 as in the present invention, only the rotation speed varying means is used. Configuration (including control)
(See claim 10). Each operation of the stencil printing apparatus which is not limited to the modified example 2 can be easily implemented from the above-described operation examples 1 to 4 and the like, and the description thereof will be omitted.

(Modification 3 of Embodiment 1) Modification 3 of Embodiment 1 will be described with reference to FIGS. 14 and 15. This modification 3 is different from modification 2 in that a heating means 160 shown in FIG. 14 and a temperature sensor 163 as an environment temperature detecting means for detecting an environment temperature shown in FIG. 15 are added to the configuration of the modification 2. , And the controller 90B in place of the controller 90B of the second modification,
The heating means 1 is based on the output signal from the temperature sensor 163.
The main difference is that it has a control device 90C that also has the function of controlling 60.

The heating means 160, as shown in FIG.
The stencil printing apparatus 2 is configured to heat the surface of the outer peripheral portion 9a on the upstream side in the rotation direction B of the transfer drum 9 with respect to the area close to the plate cylinder 1.
No. 00 of the main body frame 210 (not shown in FIG. 14, see FIG. 1) is fixedly provided to an immovable member (not shown). The heating means 160 includes a heat source 161 formed of a heating tube and a part of the surface of the outer peripheral portion 9a of the transfer drum 9 that receives heat from the heat source 161, that is, a portion where the back side ink image is transferred from the plate drum 1. It is composed of a reflector 162 that is gathered on the upstream side peripheral surface portion.

By the heating means 160, the rotational direction of the transfer cylinder 9 is larger than the area K on the surface of the outer peripheral portion 9a of the transfer cylinder 9 facing the plate cylinder 1 to which the ink image for the back surface from the plate cylinder 1 is transferred. The upstream part of B is preheated. Therefore, when the ink for the back surface is transferred from the plate cylinder 1 to the transfer cylinder 9, the ink present on the outer peripheral surface of the plate cylinder 1 is temporarily warmed by the contact with the heated transfer cylinder 9. Viscosity decreases.
Therefore, the amount of ink transferred from the plate cylinder 1 to the transfer cylinder 9 is larger than that in the conventional case, and as a result, the amount of ink retransferred from the transfer cylinder 9 to the back surface of the printing paper P and the printing paper directly from the plate cylinder 1 are performed. The amount of ink transferred to the surface of P can be balanced. As the heating tube used as the heat source 161, for example, a halogen lamp can be used.

Like the control device 90B, the control device 90C is equipped with a plurality of microcomputers, and CP
A U91C, an I / O (input / output) port (not shown), a ROM 92C, a RAM 93, and the like are provided and are connected by a signal bus (not shown). Temperature sensor 16
3 is, for example, a body frame 210 (see FIG. 1) near the transfer cylinder 9.
4 is omitted). The temperature sensor 163 is connected to the CPU 91C of the control device 90C via a sensor input circuit and an input port (not shown). As shown in FIG. 15, the CPU 91C of the control device 90C (hereinafter sometimes simply referred to as “control device 90C”) is connected to the heat source 161 via an output port and a heat source drive circuit (not shown), and the temperature sensor 163. It has a function of controlling the heat generation amount of the heat source 161 based on the output signal from the.

The control device 90C determines the amount of heat applied to the transfer cylinder 9 by the heating means 160 on the basis of the environmental temperature information detected by the temperature sensor 163, the image density of the front side print image of the printing paper P and the back side print image. The image density is automatically adjusted to an appropriate value so as to obtain a uniform state. In addition, the user can manually adjust the heating amount of the heating unit 160 by operating a temperature adjustment key (not shown) provided on the operation panel 140 while checking the state of the printed matter. The amount of heating by the heating means 160 is adjusted by adjusting the energization time by changing the duty ratio of a PWM (pulse width modulation) method or the like.

The embodiment of the present invention is not limited to the third modification,
In the first embodiment, the modified examples 1 and 2 described above, the heating means 160 is arranged as shown in FIG. 14, and the heating means 160 is based on the output signal from the temperature sensor 163.
It is also possible to add a function for controlling the above to each control device 90, 90A, 90B.

Not limited to the modified example 3, the one-plate cylinder split transfer cylinder one-pass double-sided printing disclosed in, for example, Japanese Unexamined Patent Publication No. 10-129100, which is not disclosed about the peculiar plateless area 25 as in the present invention. In the stencil printer of the system,
The heating means 160 may be arranged as shown in FIG. 14 and a control device for controlling the heating means 160 based on the output signal from the temperature sensor 163 may be provided. (Refer to the third technical configuration in the means column). Further, the stencil printing apparatus according to the fifth to seventh technical configurations in the means column for solving the problem may be used. As described above, it can be said that the stencil printing method according to the invention of claim 9 was used in the first embodiment, the modified examples 1 to 3, and the like.

The configurations of the first embodiment, the modified examples 1 to 3 and the operation examples 1 to 4 and the like are not limited to the examples described above, but may be as follows. For example, in the block diagram of FIG. 9, an image memory (not shown) is provided as an image storage unit that transmits and receives to and from the image processing device 89, and each image of the back side document 74 and the front side document 74 is continuously read. As described above, the ADF driving unit 71A is controlled so that only the read image data of the original 74 for the surface is temporarily stored in the image memory, and is stored in the image memory when the plate-making image for the surface is produced. An image signal related to image data is called to control device 90 (in the plate making control device portion)
This is done by inputting in. In this way, after the original 74 for the back side and the original 74 for the front side are set on the original cradle 72, the plate making star key 141 is set to 1
A series of operations from the plate discharge to the sheet discharge can be automatically performed by just pressing the plate once, and the plate-making star key 141 as a trigger at the time of reading an image of the front-side document 74.
Since the pressing operation of can be omitted, the operability is improved.

In the first embodiment, the first to third modifications, etc., from the viewpoint that the image quality of the front surface print image formed on the front surface of the printing paper P is more important than that of the back surface print image,
The back side plate-making image area 24, the non-plate-making area 25, and the front side plate-making image area 23 are formed on the master 22 in this order. is there. In this case, first, the front side document 74
Image is read, a plate-making image for the front side is formed on the master 22 in accordance with this image information, and a predetermined plate-making area 25 is formed. Then, the backside plate-making image may be formed on the master 22.

When one side of the printing paper P to be printed is a character image and the other side is a photographic image, the photographic image may be difficult to see if the image densities are the same. In such a case, the operation panel 140 is provided with an original designating key for designating the backside document 74 and the frontside document 74 and a photographic image mode setting key (not shown) as appropriate.
It is desirable that the density can be appropriately adjusted from the 40 side.

The plate-making means is not limited to the above-mentioned thermal head 26 for selectively heating the master 22 to perforate the plate, but may be a plate-making means such as a heat-sensitive stencil using a xenon lamp or a laser plate making with a laser beam. Well,
The present invention can be applied mutatis mutandis even when such a plate-making means is used (except claim 6).

The image data relating to the document 74 transmitted to the image processing device 89 via the image sensor 85 and the A / D conversion device 88 shown in FIGS.
For example, a personal computer controller (not shown) for receiving image data from a personal computer is provided in the main body frame 210, and the image data from the personal computer is transmitted to the image processing device 89 via the personal computer controller, It is of course possible to prepare a backside plate-making image and a front side plate-making image based on this.

As described above, the present invention has been described with reference to the particular embodiment of the invention and the examples included therein, but the configuration of the present invention is limited to the above-described embodiment 1 and the modifications 1 to 3 and the like. However, it may be configured by appropriately combining these, within the scope of the present invention,
It is obvious to those skilled in the art that various embodiments and examples of the invention can be configured according to the necessity and the purpose / application.

[0233]

As described above, according to the present invention,
A novel stencil printing apparatus and a new stencil printing method can be provided by solving various problems of the conventional apparatus as described above. According to the present invention, a known effect of the one-plate cylinder divided transfer cylinder one-pass double-sided printing system, that is, one plate cylinder and one transfer cylinder, and one plate-making device and one plate-discharging device are provided. Since it is possible to print on both sides of the printing paper at the same time by using the master of one version, it is possible to reduce the cost by reducing the number of parts and downsize the device. The effect peculiar to each claim of is produced.

According to the first aspect of the invention, the pressing force of the transfer cylinder against the plate cylinder is applied between the plate-making image area for the front surface and the plate-making image area for the back surface along the rotation direction of the plate cylinder in the master which has been made. In order to change the pressing force switching time required to change, the rotation speed switching time required to change the rotation speed of the plate cylinder, and the energy for punching the master according to the front side plate making image area and the back side plate making image area. By forming a plateless region of a predetermined length corresponding to at least one switching time of the perforation energy switching time, it is possible to prevent uneven image density between the front side print image and the back side print image. can do. Further, since the plate-making region having a predetermined length is formed, it is possible to prevent the boundary line when switching the pressing force, the rotation speed, and the energy for punching from appearing as a printed image.

According to the second aspect of the present invention, the pressing force at the time of transfer of the transfer cylinder to the plate cylinder at the time of transferring the back side plate-making image and the pressing force of the transfer cylinder at the time of printing on the plate cylinder at the time of double-sided printing by the pressing force varying means. By changing the pressure and
It has become possible to adjust the amount of ink passing from the front side plate making image to the front side of the printing paper and the amount of ink passing at the time of transferring the back side plate making image. Since it is possible to adjust the ink passage amount at the time of retransfer and the ink passage amount from the surface plate-making image to the surface of the printing paper, it is possible to adjust between the front side printing image and the back side printing image. It is possible to reduce the difference in image density that occurs in the image.

According to the third aspect of the invention, since the pressing force at the time of transfer is switched to the pressing force at the time of printing at the rotational position of the plate cylinder corresponding to the plate-making area of the master on the plate cylinder which has already been made,
The effect of the invention according to claim 1 is exerted.

According to the fourth aspect of the present invention, the rotational speed varying means can change the rotational speed during transfer of the plate cylinder during transfer of the backside plate-making image and the rotational speed during printing of the plate cylinder during double-sided printing. This makes it possible to adjust the ink passage amount from the front plate making image to the front surface of the printing paper and the ink passage amount at the time of transferring the back plate making image,
It is possible to adjust so that the amount of ink passing from the back side ink image on the transfer cylinder to the back side of the printing paper and the amount of ink passing from the front side plate making image to the front side of the printing paper are equal. Therefore, it is possible to reduce the image density difference that occurs between the front side print image and the back side print image.

According to the fifth aspect of the present invention, the rotational speed during transfer is switched to the rotational speed during printing at the rotational position of the plate cylinder corresponding to the plateless region of the master on the plate cylinder that has been prepressed. The effects of the invention described in 1 are achieved.

According to the sixth aspect of the invention, the perforation is supplied to the individual heating elements of the plate making means in accordance with the formation of the front plate making image and the back side plate making image by the punching energy varying means. By changing energy and
It has become possible to adjust the ink passage amount from the front side plate making image to the front side of the printing paper and the ink passage amount at the time of transferring the back side plate making image, so that the back side ink image on the transfer cylinder is transferred to the back side of the printing sheet. 6. It is possible to adjust so that the ink passage amount at the time of retransfer and the ink passage amount from the surface plate-making image to the surface of the printing paper can be adjusted, and therefore, it is possible to set the ink amount to the same. In addition to the effect of the invention described above, it is possible to reduce the difference in image density that occurs between the printed image for the front surface and the printed image for the back surface.

According to the seventh aspect of the invention, the control means forms the plateless area by selecting the data relating to the predetermined length of the plateless area from the storage means based on the signal from the start setting means. Since the plate making apparatus is controlled in accordance with the above aspect, the effect of the invention according to claim 1 is achieved.

According to the eighth aspect of the invention, the aperture ratio of the mesh screen corresponding to the back side plate-making image area in the plate-making master wound on the mesh screen corresponds to the front side plate-making image area. Is larger than the above, and the switching position of the aperture ratio corresponds to the plate-less area of the master that has been plate-wound on the mesh screen. It has become possible to more easily adjust the passage amount and the ink passage amount during the transfer of the backside plate-making image, and the ink passage amount at the time of retransfer from the backside ink image on the transfer cylinder to the backside of the printing paper. Since it is possible to easily adjust so that the amount of ink passing from the surface plate-making image to the surface of the printing paper becomes equal, it is possible to adjust between the front surface printing image and the back surface printing image. It is possible to reduce the image density difference of product in the more pronounced form.

According to the invention of claim 9, the pressing force of the transfer cylinder with respect to the plate cylinder is applied between the plate-making image area for the front surface and the plate-making image area for the back surface along the rotation direction of the plate cylinder in the master which has already been made. In order to change the pressing force switching time required to change, the rotation speed switching time required to change the rotation speed of the plate cylinder, and the energy for perforating the master according to the front side plate making image area and the back side plate making image area. Occurred between the print image for the front surface and the print image for the back surface by using a plate-making master in which a plate-making area having a predetermined length corresponding to at least one of the switching time for the required energy for punching is formed. It is possible to prevent uneven image density. Further, since a master having a plate-making area having a predetermined length is used, it is possible to prevent the boundary line when switching the pressing force, the rotation speed and the energy for punching from appearing as a printed image.

According to the tenth aspect of the invention, the rotational speed changing means can change the rotational speed of the plate cylinder during transfer of the back side plate-making image and the rotational speed of the plate cylinder during printing of double-sided printing. This makes it possible to adjust the amount of ink passing from the plate-making image for the front surface to the surface of the printing paper and the amount of ink passing when transferring the plate-making image for the back surface. It is possible to adjust so that the ink passage amount at the time of retransfer to the back side and the ink passage amount from the front side plate making image to the front side of the printing paper become equal, so the front side print image and the back side print image It is possible to reduce the difference in image density that occurs between and.

[Brief description of drawings]

FIG. 1 is a schematic front view of a stencil printing machine showing a first embodiment to which the invention is applied.

FIG. 2 is a schematic cross-sectional view of a master used in Embodiment 1 and the like.

FIG. 3 is a partially sectional front view showing a plate making plate supply unit of Embodiment 1 and the like in an enlarged manner.

FIG. 4 is a plan view of a mesh screen and a master on which a plate has been made, which is developed and viewed from the outer peripheral surface side.

FIG. 5 is a front view around the contacting / separating means and the pressing force varying means according to the first embodiment.

FIG. 6 is an enlarged side view of the periphery of the pressing force varying means of FIG.

FIG. 7 shows a transfer pressing force and a printing pressing force applied in correspondence with a backside plate-making image area, a plate-less plate-making image area, and a front-side plate-making image area in a plate-making master on the plate cylinder in Embodiment 1 and the like. It is a graph which shows a relationship.

FIG. 8 is a plan view of the operation panel according to the first embodiment and the like.

FIG. 9 is a block diagram showing a control configuration of the first embodiment, modified examples 1 and 2.

FIG. 10 is an operation diagram showing a transitional state of the rotational operation of the plate cylinder and the transfer cylinder in the first embodiment and the like.

FIG. 11 is an operation diagram showing a transition state of a sheet feeding state and a rotation operation of a plate cylinder and a transfer cylinder in the first embodiment and the like.

FIG. 12 is an operation diagram showing a double-sided printing state by the plate cylinder and the transfer cylinder in the first embodiment and the like.

FIG. 13 is a graph showing the relationship between the rotational speed during transfer and the rotational speed during printing corresponding to the backside platemaking image area, the platemaking image area for front side, and the platemaking image area for front side in the platemaking master on the plate cylinder in Modification 2; Is.

FIG. 14 is a front view of a main part around a heating unit in a modified example 3.

FIG. 15 is a block diagram showing a control configuration of modification 3;

[Explanation of symbols]

1 plate cylinder 2A support cylinder 2B mesh screen 5 ink supply means 6 ink supply roller 9 transfer cylinder 9a outer peripheral portion 12 paper clamper 15 printing plate cylinder device 16 plate supply printing drive section 17 main motor 17A main part constituting rotation speed varying means Motor drive circuit 19 Ink image for back side 20 Plate making plate supply unit 22 as plate making apparatus Master 23 Front plate making image area 24 Back side plate making image area 25 No plate making area 26 Thermal head 26a Heating element 26A as a plate making means Thermal head driving circuit 30 Master Transport Motor 30A Master Transport Motor Drive Circuit 39 Plate Making Plate Drive Unit 40 Sheet Feed Unit as Paper Feed Unit 46 Paper Feed Drive Unit 50 Plate Ejection Unit 56 as Plate Ejection Device 56 Plate Ejection Drive Unit 60 Plate Ejection Unit 67 as Paper Ejector Device Paper ejection drive unit 70 Original reading device 71A ADF Moving part 74 Original document 80A Scanner driving part 89 Image processing devices 90, 90B, 90C Control device 90A as control means Control device 90B as control means also functioning as energy varying means Control device 92 as control means also acting as rotation speed varying means 92A, 92B, 92C RO as storage means
M 117 front surface printing area 118 back surface printing area 120 contact / separation means 130 pressing force variable means 131 pressing force variable motor 131A pressing force variable motor drive circuit 140 operation panel 141 plate making start key 143 constituting startup setting means Double-sided print setting key 152 Encoder sensor 200 Stencil printer 210 Main body frame F1 Transfer pressing force F2 Printing pressing force P Printing paper V1 Transfer rotating speed V2 Printing rotating speed X1 Original conveying direction X2 Master conveying direction X3 Paper conveying direction

Claims (10)

[Claims] 1. A plate making apparatus for perforating a master to form a front plate making image and a back plate making image according to image information, a front plate making image area in which the front plate making image is formed, and A plate cylinder around which a plate-making master having a back plate-making image area on which a back plate-making image is formed, and a plate making plate for the back side which is provided so as to face the plate cylinder and can come into contact therewith A transfer cylinder on which an ink image for the back side is formed on the surface by the ink that has passed through the image, and a printing paper is fed between the plate cylinder and the transfer cylinder on which the ink image for the back side is formed. In the stencil printing apparatus capable of simultaneously printing on both sides of the printing paper by sending, the plate making apparatus is the plate making image area for the front surface and the back surface along the rotation direction of the plate cylinder in the master having been made. Plate making image area Between the area and the area, the pressing force switching time required to change the pressing force of the transfer cylinder with respect to the plate cylinder, the rotation speed switching time required to change the rotation speed of the plate cylinder, and the surface plate-making image area and Characteristic of forming a plateless area of a predetermined length corresponding to at least one switching time of the punching energy switching time required to change the punching energy for punching the master according to the backside platemaking image area And a stencil printer. 2. The stencil printing apparatus according to claim 1, wherein the transfer pressing force of the transfer cylinder against the plate cylinder during transfer of the backside plate-making image, and the transfer cylinder relative to the plate cylinder during double-sided printing. A stencil printing machine comprising a pressing force varying means for changing a pressing force during printing. 3. The stencil printing apparatus according to claim 2, wherein at the rotational position of the plate cylinder corresponding to the plateless area of the plate-made master on the plate cylinder, the pressing force at the transfer is applied to the printing press. A stencil printing machine characterized by switching to pressure. 4. The stencil printing apparatus according to claim 1, wherein a rotation for changing a rotational speed during transfer of the plate cylinder during transfer of the backside plate-making image and a rotational speed during printing of the plate cylinder during double-sided printing. A stencil printing machine having a speed varying means. 5. The stencil printing apparatus according to claim 4, wherein at the rotational position of the plate cylinder corresponding to the plateless region of the plate-made master on the plate cylinder, the rotational speed during transfer is changed to the rotational speed during printing. A stencil printing machine characterized by switching to speed. 6. The stencil printing apparatus according to claim 1, further comprising: a plate-making device having a plurality of heating elements in a main scanning direction for punching a master, and the surface plate-making image. A perforation energy changing means for changing the perforation energy supplied to each heating element of the plate making means in accordance with the time of formation and the formation of the backside plate making image; The stencil printing apparatus is characterized in that the switching of punching energy corresponds to the plateless region. 7. The stencil printing apparatus according to claim 1, wherein start setting means for starting the plate making apparatus and data regarding a predetermined length of the plateless area are stored in advance. Control for controlling the plate making apparatus so as to form the plateless area by selecting data relating to a predetermined length of the plateless area from the storage means based on a signal from the storage means and the activation setting means. A stencil printing apparatus comprising means. 8. The stencil printing apparatus according to claim 1, wherein an ink permeable mesh screen is wound around the outer peripheral surface of the plate cylinder, and the mesh screen is placed on the mesh screen. The aperture ratio of the mesh screen corresponding to the back side plate-making image area in the plate-making master to be wound is set larger than that corresponding to the front side plate-making image area, and the opening ratio switching position Corresponds to the plateless region of the plate-made master wound on the mesh screen. 9. A master winding method for winding a pre-made master having a front plate-making image area on which a front plate-making image is formed and a back-side plate-making image area having a back-side plate-making image formed on a plate cylinder. Transfer step of forming an ink image for the back side on the surface of the transfer cylinder by the ink that has passed through the plate-making image for the back side from the inside of the plate cylinder by a transfer cylinder provided so as to be able to contact the plate cylinder And a stencil printing method including a double-sided printing step of simultaneously printing on both sides of the printing paper by feeding the printing paper between the plate cylinder and the transfer cylinder on which the ink image for the back side is formed. , A pressing force required to change the pressing force of the transfer cylinder with respect to the plate cylinder between the front plate-making image area and the back plate-making image area in the plate-making master along the rotation direction of the plate cylinder. Switching time , For perforation required to vary the rotational speed switching time required to change the rotational speed of the plate cylinder and perforation energy for perforating the master according to the front side plate making image area and the back side plate making image area A stencil printing method characterized by using a master that has been plate-formed and has a plate-less region of a predetermined length corresponding to at least one of the energy switching times. 10. A plate cylinder, around which a plate-made master on which a plate-making image for the front surface and a plate-making image for the back surface are formed is wound, is provided so as to face the plate cylinder so as to be in contact therewith, and A transfer cylinder on which an ink image for the back side is formed by the ink that has passed through the plate-making image for the back side, and printing between the plate cylinder and the transfer cylinder on which the ink image for the back side is formed. In a stencil printing apparatus capable of simultaneously printing on both sides of a printing sheet by feeding a sheet, in the transfer rotation speed of the plate cylinder at the time of transferring the back side plate-making image, and at the time of double-sided printing A stencil printing machine having a rotation speed varying means for changing a rotation speed of a plate cylinder during printing.