JP4672991B2 - Duplex printing device - Google Patents

Description

  The present invention relates to a duplex printing apparatus, and more particularly to a duplex printing apparatus including a duplex stencil printing apparatus and the like.

In general, a laminate structure in which a thermoplastic resin film having a thickness of approximately 1 to 2 μm and a porous support made of Japanese paper fiber or synthetic fiber or a mixture of Japanese paper fiber and synthetic fiber are bonded together. The surface of the thermoplastic resin film of the stencil master (hereinafter referred to as “master”) is brought into contact with the heat generating element of the thermal head and heated perforated / engraved through the operation of the thermal head in the main scanning direction. While moving the master made by master transport means such as a roller (hereinafter sometimes referred to as “pre-mastered master”) in the sub-scanning direction (master transport direction) perpendicular to the main scanning direction, for example, resin or A mesh screen made of a metal mesh body is wound around a porous cylindrical rotatable plate cylinder having a structure in which a plurality of layers are wound. Ink is supplied from the supply member to the master that has been made on the plate cylinder, and the plate on the plate cylinder is pressed by a press means called a press roller, an impression cylinder, or an intermediate press roller (hereinafter referred to as “press roller”). Thermal digital that performs printing by continuously pressing printing paper (hereinafter simply referred to as “paper”) onto the finished master and allowing ink to ooze out from the perforated part of the plate cylinder and the perforated part of the master and transfer it to the paper. A stencil printing apparatus of the type is known. Also known is a stencil transfer printing apparatus that once transfers the ink that has oozed out from the opening portion of the plate cylinder to a transfer cylinder having a rubber sheet and then prints it on a sheet (see, for example, Patent Document 1).
Note that the “plate cylinder” is sometimes simply referred to as a printing drum or a plate cylinder disposed on the outer periphery of the printing drum. I will call it.

In the above-described stencil printing, in addition to single-sided printing that prints only on one side of the paper, in recent years, printing is performed on both front and back sides of the paper for the purpose of reducing paper consumption and document storage space. Double-sided printing has come to dominate. As a conventional double-sided printing method / method, using a stencil printing apparatus or the like that performs normal single-sided printing as described above, the paper stacked on the paper feeding unit is passed through the printing unit, and one side of the paper ( Double-sided printed matter by printing over the printed paper that has been printed on the front side and then discharged and stacked on the paper discharge tray, etc., and then passing through the printing section again and printing on the remaining side (back side) of the printed paper Is what you get. In this double-sided printing method, printing is performed twice, or the total printing is necessary because it is necessary to increase the waiting time until the ink of the single-sided printed matter after the single-sided printing is sufficiently dried to be in a set state. As the time becomes very long, the work of neatly arranging the single-sided printed matter or the setting of the single-sided printed matter again in the paper feeding unit is very troublesome.
In order to improve the conventional double-sided printing method with manual operation as described above, a double-sided printing device capable of automatically performing double-sided printing has been actively developed, and there are several types of double-sided printing devices. Although proposed, they are mainly classified into the following six types, and have advantages and problems described later.

  (1) Two-drum opposed one-pass simultaneous duplex printing method: a first plate cylinder, a second plate cylinder disposed opposite to the first plate cylinder via a paper conveyance path, and a first plate cylinder There is provided contact / separation means for bringing the outer peripheral surface and the outer peripheral surface of the second plate cylinder into contact with and separating from each other. By operating the contact / separation means, the plate cylinders are brought into pressure contact with each other. A double-sided printing method that obtains a double-sided printed matter by performing front-side printing for printing on the front side of the paper, which is one side of the paper, and back-side printing for printing on the back side of the paper, which is the other side of the paper, in a single pass (For example, see Patent Document 2).

  In the double-sided printing method (1), two plate cylinders are arranged one above the other so that they are pressed against each other. Therefore, it is necessary to press the plate cylinders together even during single-sided printing. In this case, a master for making a plate must be wound on the master and an unprinted master (no plate master) must be wound on the other plate cylinder. The master is unnecessarily consumed during single-sided printing and the operation is troublesome. There is a problem. In addition, in order to hold the master on the outer peripheral surface of each plate cylinder and to have a clamper of a type protruding outward from each outer peripheral surface, in order to press the two plate cylinders together It is necessary to separate the plate cylinders at the positions where the clampers face each other. When the printing speed is increased, the area where the plate cylinders come into contact with each other is reduced and the image amount area is reduced. In order to achieve this, it is necessary to increase the outer diameter of each plate cylinder, which makes it difficult to reduce the size of the apparatus due to an increase in the size of the apparatus. However, it is very difficult to prevent the sheet from being rolled up.

  (2) Stock refeed type after single-sided printing, two-pass double-sided printing method ... Contrast to the conventional device configuration of a single-sided stencil printing device, the paper discharge unit provided with a paper discharge tray is movable. By adding the function of the paper feed tray to the paper discharge tray or adding a new reverse paper feed path, etc., the paper loaded on the paper feed unit is passed through the printing unit for surface printing. Once the printed paper on the front side is discharged and stacked on the paper discharge tray, the front side printed paper on the paper discharge tray is turned over by being conveyed to the reverse feeding path, and is again passed through the printing unit. This is a double-sided printing method in which a double-sided printed material is obtained by printing (see, for example, Patent Document 3). This double-sided printing method has the advantage that it can be used with only a slight modification of the conventional single-sided stencil printing apparatus and its configuration.

  On the other hand, in the double-sided printing method (2), in addition to the problem that the printing time is increased until double-sided printed material is obtained by performing printing twice, the printed material after surface printing is sufficiently dried. Since it is not in a so-called set state, when printing is finished on the back side immediately after the front surface printing is finished, pressing means such as a transport roller and a press roller are pressed against the image portion, and the printed image becomes ink or the like. As a result of the problem of smearing or disturbing the sheet, once the surface-printed paper that has been surface printed once is separated and transported again, jamming is likely to occur and the printing apparatus becomes large.

  (3) Two-drum facing transfer cylinder intervening one-pass simultaneous double-sided printing method: first and second plate cylinders that are provided with ink supply means and are rotatable by winding a master around the outer peripheral surface; Using a transfer cylinder positioned between the second plate cylinder and transferring the ink image from the second plate cylinder to the transfer cylinder, and then transferring the ink image on the transfer cylinder to the back side of the same paper. Is a double-sided printing method in which printing is simultaneously performed on the front and back surfaces of a sheet (see, for example, Patent Document 4). In the double-sided printing method (3), the density difference and the image quality difference between the printed images on the front surface and the back surface cannot be eliminated. As a result, the 3 drums including the transfer cylinder are arranged, resulting in a large printing apparatus. Or has to be cleaned.

  (4) 1-drum split printing simultaneous reversal type duplex printing method: a printing drum on which a master plate having a first plate-making image and a second plate-making image formed is wound, and paper is supplied in the vicinity of the printing drum And a first paper image formed on the first surface of the paper by pressing the first surface of the paper supplied by the paper feeding device against the first plate-making image on the printing drum. Pressing means, paper reversing means for reversing the paper on which the first print image is printed on the first surface, and the second surface of the paper reversed by the paper reversing means is the second surface on the printing drum. A second pressing unit that presses against the plate-making image to form a second print image on the second surface of the paper, and simultaneously prints on the front and back surfaces of the paper in one plate-making process and one printing process. This is a double-sided printing method (see, for example, Patent Document 5).

  In the double-sided printing method (4), compared with the above-described three double-sided printing methods and the one-drum divided transfer cylinder 1-pass double-sided printing method described later, if the image size during double-sided printing is limited, a compact printing apparatus can be used. However, there is no problem in single-sided printing and the density difference between the printed images on the front and back sides, and both sides can be printed at high speed in a short time, saving the time required for printing, and the advantage of high productivity. Have. On the other hand, in the above-mentioned double-sided printing method (4), for example, in the printing apparatus described in Japanese Patent Application Laid-Open No. 9-95033, there is a serious question about the certainty / reliability of paper conveyance and high-speed printing compatibility. In addition, two press means (primary and secondary press rollers 17, 24 as first and second press means) are used, and ink supply means (7, 8) are provided in the plate cylinder correspondingly. There is also a problem that the configuration around the printing unit, which requires two places, is complicated.

  (5) 1-drum divided transfer transfer cylinder 1-pass double-sided printing method: This is a double-sided printing method located in the middle of (3) and (4) (for example, see Patent Document 6). A basic configuration of a stencil printing machine adopting this one-drum divided transfer cylinder one-pass duplex printing system includes a plate cylinder having a printing area for the front surface and a printing area for the back surface on the outer peripheral surface of one plate cylinder, Conveying means for conveying paper between a transfer cylinder on which the back side ink image transferred by the ink that has passed through the back side printing area is formed, and a transfer cylinder on which the plate cylinder and the back side ink image are formed Etc.

  In the double-sided printing method of (5), the paper passes between the plate cylinder and the transfer cylinder on which the back-side ink image is formed, so that printing can be simultaneously performed on the front and back surfaces of the paper in one pass. That is, in the double-sided printing method, it is only necessary to have one plate cylinder, one ink supply means, one transfer cylinder, and one plate-making unit and plate-removing unit, respectively. By making the diameter ratio between the plate cylinder and the transfer cylinder 2: 1, the plate cylinder and the transfer cylinder are continuously rotated at a constant rotation speed (constant rotation speed). There is also an advantage that printing can be performed.

On the other hand, in the double-sided printing method of (5), the ease of ink ejection 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 the material having ink repellency is the transfer cylinder. In addition, for example, when compared on the basis of simultaneous printing on the front and back surfaces based on the same plate-making image of the same document, the outer periphery of the transfer cylinder The amount of ink transferred to the surface is smaller than the amount of ink transferred directly from the outer peripheral surface of the plate cylinder to the paper. As a result, even in the double-sided printing method, there is a problem in that unevenness in the print image density or difference in print image density occurs between the print image for the front surface and the print image for the back surface.
(6) All the problems (1) to (5) above can be solved, and one-sided printing can be performed without using a useless master, and a printed matter with good image quality can be obtained during double-sided printing. Innovative one-step double-sided printing device capable of suppressing an increase in installation space, that is, the double-sided printing method (4) is a basic method (however, a press roller and a single ink as a single pressing means) Adopting supply means) (hereinafter referred to as “one-drum one-pressing means double-sided printing method or one-plate cylinder one-pressing means double-sided printing method”), lack of certainty and reliability of paper conveyance and high-speed printing compatibility A new double-sided printing apparatus that solves and solves the problem has been proposed and tried (see, for example, Patent Documents 7 and 8).

  Incidentally, in Japanese Patent Laid-Open No. 2003-200355 proposed by the applicant of the present application, as shown in FIG. 17, a single plate cylinder 212 and a press having a diameter smaller than the outer diameter of the plate cylinder 212 as a single pressing means. A double-sided printing apparatus 201 having a novel configuration such as an auxiliary tray 208 as a refeed storage unit, a refeed unit 209, a switching member 210 as a switching unit, and the like by skillfully utilizing the sheet conveying action by the rotation of the roller 213. It is disclosed. Each symbol used in FIGS. 17 and 18 corresponds to a symbol obtained by adding the numeral 200 to the symbol in each figure of the above-mentioned Japanese Patent Application Laid-Open No. 2003-200355 (however, the symbol indicating paper is not limited to this).

  17 and 18, reference numeral 208 a denotes an end fence integrally formed with the auxiliary tray 208, and reference numeral 208 c denotes an auxiliary tray 208 provided with the other end of the surface-printed paper close to the refeed positioning member 224. Re-feeding sensor 222 serving as a surface printed sheet detecting means for detecting this is guided to the plate cylinder 212 while the conveyed surface printed sheet is brought into contact with and held on the outer peripheral surface of the press roller 213. Reference numeral 223 denotes a re-feeding guide member serving as a paper guiding unit. The re-feeding guide unit 225 presses the surface-printed paper conveyed by the re-feeding conveyance unit 225 with a predetermined pressure contact with the outer peripheral surface of the rotating press roller 213. Re-feeding as a press contact means that can be displaced between a press contact position indicated by a solid line in the drawing and a separate position (not shown) that is spaced from the outer peripheral surface of the press roller 213 The registration roller, numeral 224 a refeed positioning member for temporarily stopping the other end of the surface-printed sheet to be fed again to the printing unit 202 by refeeding unit 225 in place, respectively.

  Reference numeral 225 denotes a re-feed conveyance unit having a conveyance unit main body 235, a driving roller 236, a driven roller 237, an endless belt 238, a suction fan 239, and the like. Reference numeral 226 denotes a cleaning unit that cleans the outer peripheral surface of the press roller 213. Reference numerals 227 to 230 denote guide plates that guide the cleaning roller 227 so that the surface-printed paper fed from the printing unit 202 does not touch the cleaning roller 226 and toward the auxiliary tray 208. The rollers 231, 231, and 230 are provided integrally with each other and press the respective peripheral surfaces thereof against the outer peripheral surface of the press roller 213. Reference numeral 231 indicates the peripheral surfaces of the rollers 228, 229, and 230 to contact the outer peripheral surface of the press roller 213. A paper guide plate with a plurality of openings (not shown) 56 is a guide plate that guides the surface-printed paper to the auxiliary tray 208 between the guide plate 227 when the switching member 210 occupies the second position shown in FIG. A paper discharge conveyance unit that is disposed below the claw and to the left of the switching member 210 and includes a driving roller 287, a driven roller 288, an endless belt 289, a suction fan 290, and the like is shown.

  In the duplex printing apparatus 201 shown in FIG. 17, during duplex printing, the first sheet (not shown) is fed from the paper feed unit (not shown) to the printing unit 202 and is placed on the plate cylinder 212 on the surface thereof. Printing corresponding to a first plate-making image (both not shown) of the wound divided plate-making master was performed, and the printed first surface-printed paper PA1 was guided to the auxiliary tray 208 by the switching member 210. Thereafter, a second sheet (not shown) is fed from the sheet feeding unit to the printing unit 202, and printing corresponding to the first plate-making image of the divided plate-making master is performed on the surface and re-feeding is performed. The first front-side printed paper PA1 is fed again to the printing unit 202 by means 209, and printing corresponding to the second plate-making image of the divided plate-making master is performed on the back side, and the first member is printed by the switching member 210. Paper on both sides printed (not shown) 06, well-known behavior of the second sheet surface-printed sheet PA2 guiding respectively the auxiliary tray 208 is performed.

JP-A-6-48014 JP-A-6-71996 JP-A-7-81202 JP-A-8-118774 JP-A-9-95033 JP-A-10-129100 JP 2003-200355 A JP 2003-266906 A

  However, in the above-described double-sided printing apparatus 201, as shown in FIG. 17, during the double-sided printing operation, the second sheet passes through the printing nip portion between the plate cylinder 212 and the press roller 213, and the second surface printing is performed. When the paper PA2 is sent to the auxiliary tray 208, the first surface-printed paper PA1 is sent from the auxiliary tray 208 toward the nip portion between the plate cylinder 212 and the press roller 213. At this time, as shown in the figure, the front end, which is one end of the surface-printed paper PA2, is a print image surface on one end side (front end side) of the front-printed paper PA1 (in FIG. 17, the upper surface of the front-printed paper PA1 is the ink As a result, the one side and the back side of the surface-printed paper PA2 are rubbed and stained, and the one side of the surface-printed paper PA1 is rubbed and stained. There is a problem.

At this time, one end of the surface-printed paper PA2 must be conveyed toward the left in the figure, but one end of the surface-printed paper PA2 comes into contact with one end of the surface-printed paper PA1 conveyed toward the right in the figure. The adhesive force of the ink on the printed paper PA1 and the conveyance force to the right in the figure cancel the conveyance force to the left in the figure, and the surface-printed paper PA2 stops on the spot and a conveyance jam occurs. There is a problem that it will.
FIG. 18 shows a state in which the plate cylinder 212 is slightly rotated from the state shown in FIG. 17, but the front surface printed paper PA2 sent is the state in which the front surface printed paper PA1 is sent and there is no paper. It is dropped on the auxiliary tray 208 and is attracted onto the auxiliary tray 208 by the suction force of the operating suction fan 239, and the conveying force to the left in the figure is canceled by the frictional force of the endless belt 238, There is a problem that conveyance of the front-side printed paper PA2 is hindered and a conveyance jam occurs.

  Further, in the double-sided printing method (6) including the above-described double-sided printing apparatus 201, when the entrance of the paper is detected to be reversed and conveyed by the press roller 213, that is, for example, the other end of the surface-printed paper Although the sensor 208c detects that the paper is positioned on the auxiliary tray 208 close to the refeed positioning member 224, the surface-printed paper does not reach between the plate cylinder and the pressing unit due to some trouble. When a jam or the like occurs, the pressing means presses against the plate cylinder (the master that has been subjected to the divided plate making) even though there is no paper, so the outer peripheral surface of the pressing means is stained with ink. . In general, it is necessary to pass a large amount of paper until the dirt is removed, or to remove the plate cylinder that is detachably attached to the apparatus main body and clean the outer peripheral surface of the pressing means. There are also problems such as being wasted and cleaning work is very troublesome.

Accordingly, the first object of the present invention is to enable one-sided printing without using a useless master, and to obtain a printed material with good image quality with no printed image density difference at the time of double-sided printing, and moreover, A double-sided printing device that is simpler than the conventional one-drum one-pressing unit double-sided printing type one-sided printing device capable of suppressing an increase in installation space, that is, a sheet clamping unit and a moving unit are newly provided. Thus, a double-sided printing apparatus capable of removing the re-feed storage means in the conventional double-sided printing apparatus, the first surface-printed paper sent out from the printing unit during the continuous double-sided printing, etc. Prevents contact with the second surface printed paper and prevents the surface printed paper from rubbing and smearing. The leading edge can be inserted without resistance, and the leading edge of the surface-printed paper can be clamped reliably and satisfactorily to prevent the occurrence of jamming of the surface-printed paper, and the surface-printed paper can meander. By preventing the image from skewing or skewing, it is possible to prevent the print image from tilting or resist from deteriorating due to tilting when printing on the back side. Further , the advantages described in the embodiments described later regarding the movement guide (81) as the sheet clamping means according to the double-sided printing apparatus proposed in Japanese Patent Application No. 2003-366423 dated October 27, 2003 by the applicant of the present application. It is an object of the present invention to provide a double-sided printing apparatus that can obtain further remarkable advantages and effects .

The second object of the present invention is to enable one-sided printing without using a useless master and to obtain a printed material with good image quality free from printed image density difference at the time of double-sided printing at low cost and moreover. 1-drum 1-pressing means capable of suppressing the increase in the double-sided printing type one-step double-sided printing apparatus, in the continuous double-sided printing, etc., the first surface printed paper and two sheets sent from the printing unit It prevents contact with the paper with the surface printed on the eyes and prevents the surface-printed paper from rubbing and smearing, and even with loose paper, the front end of the paper can be inserted without resistance, and the surface is printed. By securely and satisfactorily holding the leading edge of the paper, it is possible to prevent the front-side printed paper from being jammed, and the front-side printed paper can meander or skew. By allowing better conveyed in a state where it is not stable to or, tilting the printed image when printing on the back surface it can be prevented that such inclination would resist is deteriorated under, yet, The present applicant is more prominent than the advantages described in the later-described embodiment relating to the movement guide (81) as the sheet clamping means according to the double-sided printing apparatus proposed in Japanese Patent Application No. 2003-366423 dated October 27, 2003. An object of the present invention is to provide a double-sided printing apparatus that can obtain various advantages and effects .

  In addition to the first or second object, the third object of the present invention is that when a load or the like acts in the direction in which the front surface printed paper comes out during conveyance of the front surface printed paper, the clamping force (pushing force) It is an object of the present invention to provide a double-sided printing apparatus that can increase the pressure) and prevent the sheet from slipping out, can set the pinching force small, and can be configured at low cost without the need to make it firmly.

In order to solve the above-described problems and achieve the above object, the present invention is characterized in that the invention according to each claim adopts the following configuration.
That is, the invention described in claim 1 is the plate cylinder on which the divided plate-making master in which the first plate-making image and the second plate-making image are formed side by side along the rotation direction of the plate cylinder, A printing unit having pressing means that can be moved toward and away from the plate cylinder, a paper feeding unit that feeds paper toward the printing unit, and a printed sheet printed by the printing unit are discharged. The paper discharge unit and the printing unit temporarily hold the surface-printed paper on which the print image is formed corresponding to the first plate-making image or the second plate-making image, and then the surface-printed A sheet re-feeding unit that feeds the sheet toward the pressing unit, reverses the sheet by the pressing unit, and re-feeds the sheet toward the printing unit; and a sheet width direction of the surface-printed sheet fed from the printing unit. Hold the tip of the center near the first position near the printing part. Between the first position and the second position, a sheet clamping means that opens the front end of the front surface printed sheet at a second position near the upstream side of the refeeding means that is lower than the first position. When the paper clamping means occupies the first position, the paper clamping means is opened once and then the leading edge of the surface printed paper is clamped when the paper clamping means occupies the first position. And when the paper clamping means occupies the second position, the paper clamping means operates to release the front end of the front surface printed paper, and passes through the printing unit. A double- sided printing apparatus capable of printing on both sides of the paper with one rotation of the plate cylinder , the paper-clamping means comprising: The surface-printed paper fed from the printing unit An impact member for abutting the front end is provided, and the impact member is upstream in the direction of feeding from the printing unit for abutting the front end of the substantially center portion in the paper width direction of the surface-printed paper. And a protruding stopper part slightly protruding from the stopper member .

According to a second aspect of the present invention, there is provided the plate cylinder on which the divided plate-making master, in which the first plate-making image and the second plate-making image are formed side by side along the rotation direction of the plate cylinder, is wound, and the plate. A printing unit having pressing means that can be moved toward and away from the cylinder; a paper feeding unit that feeds paper toward the printing unit; and a paper discharge unit that discharges printed paper printed by the printing unit. And the surface-printed paper having a printed image formed on the surface thereof by the printing unit, the surface-printed paper is sent out toward the pressing means, and is reversed by the pressing means to A double-sided printing apparatus comprising: a refeed unit that refeeds toward a printing unit; and a switching unit that guides paper that has passed through the printing unit to the refeed unit or the paper discharge unit, Near the center in the paper width direction of the surface-printed paper fed from the printing unit A front end of the front-side printed sheet is opened at a second position near the upstream side of the refeeding section that is lower than the first position. Clamping means, moving means for reciprocating the paper clamping means between the first position and the second position, and when the paper clamping means occupies the first position, Once opened, the paper is operated so as to clamp the front end of the front surface printed paper, and when the paper gripping means occupies the second position, the front side of the front surface printed paper is moved by the paper gripping means. possess an actuation timing control means for actuating to open, the sheet pinching means comprises a衝止member for abutting the tip of the surface-printed sheet fed from the printing unit, the衝止member Is approximately the center in the paper width direction of the surface-printed paper Characterized in that it comprises in order to abut the front end, a convex衝止portion protrudes slightly from the衝止member on the upstream side in the direction sent out from the printing unit.

  3. The double-sided printing apparatus according to claim 2, wherein the surface-printed paper on which the printed image is formed is temporarily held by the printing unit, and then the surface-printed paper is sent toward the pressing unit. The “refeeding unit that is reversed by the pressing unit and refeeds toward the printing unit” includes, for example, “printing” in a double-sided printing apparatus described in Japanese Patent Application Laid-Open Nos. 2003-200965 and 2003-266906. Re-feed storage means for temporarily storing the surface-printed paper having a printed image formed on the surface thereof, and the surface-printed paper stored in the re-feed storage means is reversed and directed to the printing section And a refeeding means for refeeding.

  According to a third aspect of the present invention, in the double-sided printing apparatus according to the first or second aspect, the paper clamping means is a single openable and closable material that clamps the front end of the front-side printed paper in a substantially central portion in the paper width direction. It has a holding member.

According to a fourth aspect of the present invention, in the double-sided printing apparatus according to the third aspect, the sandwiching member is inclined in the advancing direction of the surface-printed paper fed from the printing unit.
Here, “the clamping member is inclined in the traveling direction of the front surface printed paper fed out from the printing unit” means that the sandwiching member is inclined with an acute rising angle with respect to the forward direction of the front surface printed paper. Means.

According to a fifth aspect of the present invention, in the duplex printing apparatus according to any one of the first to fourth aspects, the operation timing control means includes a cam.
As the “operation time control means” according to claims 1 to 4 , for example, a solenoid and an on / off control of the solenoid may be performed as long as the effect as configured with the cam according to claim 5 is not required. Also included are those composed of electrical or electromagnetic means such as control means.

ADVANTAGE OF THE INVENTION According to this invention, the various problems which the conventional double-sided printing apparatus as mentioned above has can be solved, and a novel double-sided printing apparatus can be provided. The effects for each claim are as follows.
According to the first aspect of the present invention, single-sided printing can be performed without using a useless master, and at the same time double-sided printing can be obtained inexpensively and easily with good image quality with no printed image density unevenness or printed image density difference. In addition to the fact that it is possible to insert the paper tip and moving means, it is possible to insert the leading edge of the paper without resistance even if the paper is weak, etc. A double-sided printing device that can be carried out and that is capable of suppressing an increase in installation space and that is simpler than the one-step double-sided printing device of the conventional one-plate cylinder 1-pressing means double-sided printing method, that is, the conventional double-sided printing. It is possible to provide a new double-sided printing apparatus that eliminates the need for a refeed storage unit in the apparatus, as well as a front-side printed sheet fed from the printing unit and a refeed unit. Can prevent the occurrence of rubbing stains on the surface-printed paper by preventing contact with the surface-printed paper. Spent paper does not meander or skew, and can be transported in a stable state. This prevents printing images from being tilted during printing, and resist from deteriorating due to tilt. .
In addition, since the sheet clamping means is configured to clamp the front end of the substantially center portion in the sheet width direction of the front surface printed sheet fed from the printing unit, a plurality of positions in the sheet width direction (for example, in the sheet width direction) Compared with the case where the front end of the front surface printed paper is clamped at two positions (left and right), the front end of the front surface printed paper is opened at the second position and transferred to the refeed unit or the refeed unit. At this time, the point at which the front end of the front surface printed paper is released is one place, that is, the front end of the substantially central portion in the paper width direction of the front surface printed paper. If the load on the printed paper fluctuates, there will be no problems such as skewing or distortion, and the front printed paper will be skewed by the refeed means or refeed section. With printed positional deviation or the like is suppressed by or to line becomes allow good printing with excellent paper posture,衝止member to abut the tip of the surface-printed sheet fed from the printing unit In addition, a convex bumper slightly protruding from the bumper is provided on the upstream side in the direction of feeding from the printing unit for contacting the front end of the substantially central portion in the paper width direction of the surface printed paper. Thus, when the front end of the front surface printed paper fed out from the printing unit hits the stop member, first, the front end of the front side of the front surface printed paper substantially contacts the convex end. By being conveyed in a state, a force is applied so that the front end portion of the front surface printed paper is bent slightly in a substantially U shape when viewed from the side. The paper width of the front-side printed paper with both ends of the front-side printed paper being pushed slightly and the leading edges of both sides of the front-side printed paper slightly touching the stopper Since the leading edge of the center of the direction is clamped, when the paper clamping means is moved, it is transferred to the paper refeeding means or paper refeeding section while the floats at the left and right edges in the paper width direction of the surface printed paper are tilted. It is possible to more reliably reduce the occurrence of skew or the like due to being carried or conveyed.
According to the invention described in claim 2, from the effect of the invention described in claim 1 described above, “a double-sided printing device that is more simplified than the one-step double-sided printing device of the conventional one-plate cylinder 1 pressing means double-sided printing method, That is, it is possible to provide a novel double-sided printing apparatus that eliminates the need for refeed storage means in the conventional double-sided printing apparatus.
According to the third aspect of the present invention, the sheet clamping means has a single openable and closable clamping member that clamps the front end of the substantially central portion of the surface-printed sheet in the sheet width direction. Compared to the case where the front end of the surface printed paper is clamped by the clamping members (for example, two places on the right and left in the paper width direction), the front end of the front surface printed paper is opened at the second position. When the paper is delivered to the paper re-feeding means or paper re-feeding section, there is only one point for opening the front end of the front-side printed paper. The load on the paper fluctuates, so that problems such as skewing and distortion do not occur, and the surface-printed paper is skewed or meandered by the refeeding means or refeeding unit. By chance And printing positional deviation or the like is suppressed will allow a good print with good paper posture. Further, it becomes unnecessary to wear the plurality of clamping members and to adjust the holding / pressing force of the surface-printed paper by the plurality of clamping members, so that the apparatus can be configured at low cost.

According to the fourth aspect of the present invention, the sheet clamping means is inclined in the traveling direction of the front surface printed paper fed from the printing unit, so that the front surface printed paper is conveyed when the front surface printed paper is conveyed. When a load or the like acts in the direction of pulling out, a moment in the direction to increase the holding force works, so that the paper can be prevented from being pulled out and the holding force can be set small, so it is not necessary to make it firmly and it is inexpensively configured it can.

According to the fifth aspect of the present invention, the operation timing control means has a cam so that, for example, compared with a case where an electrical means such as a solenoid and a control device for controlling on / off of the solenoid is used, the paper When the clamping means occupies the first position, the opening time for clamping the front end of the surface-printed paper can be set to be long to some extent by devising and adjusting the shape of the cam as a simple mechanical element. This makes it possible to insert the front end of a paper without any resistance even with weak paper, etc., and more reliably and satisfactorily hold the front end of the surface-printed paper. This is advantageous in terms of cost.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention (hereinafter referred to as “embodiments”) including the best mode for carrying out the present invention and examples will be described below with reference to the drawings. In the embodiments and modifications, components such as members and components having the same functions and shapes are described with the same reference numerals, and the description thereof will be omitted. In order to simplify the drawings and the description, even components that are to be represented in the drawings may be omitted as appropriate without being specifically described in the drawings. When a constituent element such as a published patent gazette is cited and explained as it is, the reference numeral is attached with parentheses to distinguish it from that of each embodiment.

  First, an overall configuration of a double-sided stencil printing apparatus 300 as an example of a double-sided printing apparatus to which an embodiment of the present invention is applied will be described with reference to FIG. As shown in FIG. 1, the double-sided stencil printing apparatus 300 is disposed at the upper left side of FIG. 1 and makes a master 8 wound in a roll shape, and is disposed at a substantially central portion in FIG. A plate cylinder 1 that winds a master (hereinafter referred to as a “plate-making master”) around an outer peripheral surface, an ink supply means that supplies ink to a plate-making master on the plate cylinder 1, and an outer peripheral surface of the plate cylinder 1 described later A printing section 16 having a press roller 21 or the like as a pressing means that presses and presses a sheet 36 (an example of a pre-sheet recording medium) against a master that has been made on and off the plate cylinder 1, and a plate making section that sandwiches the plate cylinder 1 15, a plate discharging unit 17 that peels and discharges a used master on the plate cylinder 1 and a sheet 36 on a sheet feeding tray 35 that is disposed below the plate discharging unit 17 and serves as a sheet feeding table. Paper feed unit 30 that feeds toward 16 A paper discharge unit 19 that peels off the printed paper 36 disposed below the plate making unit 15 so as to face the paper supply unit 30 and discharges it to a paper discharge tray 172 as a paper discharge table. As shown in FIG. 14, the plate cylinder 1, the plate making unit 15 and the plate discharging unit 17 (all omitted in FIG. 14) are arranged on the upper part of a main body frame 130 as a main body of the apparatus. And an image reading unit 18 for reading an image of a document 133 to be transferred or an image of a document (not shown) placed on a contact glass 135 as a reading unit.

  Further, the double-sided stencil printing apparatus 300 temporarily holds the surface-printed paper on which the printed image is formed on the surface thereof as described later, and then directs the surface-printed paper toward the press roller 21. A refeeding unit 48 that is reversed by the delivery press roller 21 and refeeds toward the printing unit 16, and a sheet that has passed through the printing unit 16 (surface-printed paper or double-sided printed paper) And a switching guide 46 as switching means for guiding to the paper discharge unit 19.

  1 to 4, the refeed unit 48 temporarily holds the front surface printed paper on which the printed image is formed by the printing unit 16, and then presses the front surface printed paper to the press roller. The paper is fed from the printing unit 16 as shown in FIGS. 1 to 6, 8, and 9. The front end of the front-side printed sheet is clamped near the moving position P1 as the first position in the vicinity of the printing section 16 in the paper width direction Y, and is upstream of the refeeding means 45 lower than the moving position P1. A movement guide 81 as a sheet clamping means for opening the front end of the surface-printed sheet at an initial position P2 (or standby position P2) as a second position in the vicinity, and a movement position P1 and an initial position P2 as shown in FIG. Movement guide 8 between When the movement guide 81 occupies the movement position P1 as shown in FIG. 9, the movement guide 81 is opened once and then the front end of the surface printed paper is clamped. A release cam 98, a release pin 99, and the like constituting an operation timing control means for operating the movement guide 81 to release the front end of the surface printed paper when the movement guide 81 occupies the initial position P2. It has.

As described above, the double-sided stencil printing apparatus 300 includes a single ink supply unit, a single plate cylinder 1 and a single press roller 21, and makes one rotation of the plate cylinder 1 as described later. Therefore, a one-plate cylinder 1-pressing means double-sided printing method capable of printing on both sides of the paper is adopted. The plate making unit 15, printing unit 16, plate discharging unit 17, paper feeding unit 30, paper discharge unit 19, image reading unit 18, refeed unit 45, movement guide 81, movement unit 87, operation timing control unit and switching Each of the guides 46 is configured as a device as will be described later.
The double-sided stencil printing apparatus 300 is different from the double-sided stencil printing apparatus 200 as an example of the double-sided printing apparatus proposed in Japanese Patent Application No. 2003-366423 dated October 27, 2003 by the applicant of the present application. The only difference is that the configuration of 28 is changed and a part of the configuration of the movement guide 81 is changed.

  The plate making unit 15 performs plate making on the master 8 and, as shown in FIG. 10, the first plate making image for surface printing along the rotation direction of the plate cylinder 1 (which is also the paper carrying direction X and the master carrying direction X1). A divided master-making master 8X having 8A (hereinafter referred to as “front-side plate-making image 8A”) and a second plate-making image 8B for back-side printing (hereinafter referred to as “back-side plate-making image 8B”), or shown in FIG. As described above, the third plate-making image 8YA (hereinafter referred to as “one-side plate-making image 8YA”) having an image amount area corresponding to two surfaces of the front-side plate-making image 8A and the back-side plate-making image 8B along the rotation direction of the plate cylinder 1 is obtained. Has a function and configuration for producing a pre-made master 8Y. The front plate-making image 8A is formed at a position corresponding to the surface region 1A shown in FIG. 1 when the divided plate-making master 8X is wound on the outer peripheral surface of the plate cylinder 1, and the back plate-making image 8B is the same as the back surface region 1B. And corresponding positions.

In FIG. 1 and FIG. 10, etc., the master-made master 8Y is distinguished from the divided master-made master 8X by adding parentheses. In FIG. 10, the area range of the single-side plate making image 8YA formed on the plate-making master 8Y is indicated by a two-dot chain line, and the boundary line of the same area range in the master transport direction X1 is the solid line of the front plate making image 8A and the back plate making image 8B. Because of the overlap, the area range is shown to be slightly larger. However, the area range of the single-side plate-making image 8YA is a front-side plate-making image 8A, a back-side plate-making image 8B, and an unfinished blank area that is located between them. This is the entire range including the plate making area 8C.
In FIG. 10, the front plate making image 8A, the back plate making image 8B, the intermediate non-plate making region 8C, and the single-side plate making image 8YA are drawn in a scale-out. In particular, the intermediate non-plate making region 8C is in the master transport direction X1. It is exaggerated and drawn.

  The plate making unit 15 includes a master support member 8c as a master support unit that supports the master 8 so that the master 8 can be fed out in the master transport direction X1, a thermal head 11 that heats and makes a master according to image information, and a thermal head. The platen roller 9 serving as a master transporting means for transporting the master 8 while rotating the master 8 in the master transport direction X1 while pressing the master 8 against the master 11, and the master 8 transported by the platen roller 9 are given appropriate tension. In addition, a pair of transport rollers 13 serving as a master transport unit that transports further downstream in the master transport direction X1 and a master 8 that has been pre-made or is not disposed in between the platen roller 9 and the pair of transport rollers 13. A master 12 that has been transported by a cutter 12 that is cut to a predetermined length, a platen roller 9 and a transport roller pair 13. Comprising a master guide plate 14 or the like for guiding the clamper 7 was expanded on the plate cylinder 1 as described below the tip.

  The master 8 has a continuous sheet shape and is wound around a synthetic resin roll core 8b to form a master roll 8a. The roll core 8 b protrudes from both end faces of the master roll 8 a and is formed longer than the width of the master 8. In the master roll 8a, the roll cores 8b on both ends are rotatably supported by the master support member 8c in a counterclockwise direction, and are detachable from the master support member 8c. The master support members 8c on both ends are attached and fixed to plate making side plate pairs (not shown) disposed on the left and right sides of the plate making portion 15 along the master transport direction X1. Therefore, the master 8 is supported by the master support member 8c so that it can be fed out from the master roll 8a in the master transport direction X1.

  The master 8 has a laminated structure in which, for example, a thermoplastic resin film having a thickness of 1 to 5 μm and a porous support made of synthetic fiber or the like are bonded together. In addition, the master is not limited to this, for example, a so-called substantially thermoplastic material in which a porous support made of Japanese paper fiber or a mixture of Japanese paper fiber and synthetic fiber and a thermoplastic resin film are bonded together. A master made only of a resin film is also used.

  The thermal head 11 extends in parallel to the platen roller shaft of the platen roller 9 and the near side and the back side of the paper surface of FIG. 1, and is provided by a contact / separation mechanism including a cam and a spring member (not shown). The platen roller 9 can be contacted and separated via the master 8. The thermal head 11 is urged by the spring member so as to contact the platen roller 9. In the main scanning direction of the thermal head 11, a large number of heat generating elements (not shown) are disposed at portions that contact the platen roller 9 via the master 8. The thermal head 11 passes through an A / D conversion unit and an image signal processing unit, both not shown, and the heat generation based on a digital image signal processed and sent out by a plate making control device and a thermal head drive circuit (both not shown). By selectively heating the element, it has a well-known function as a plate making means for selectively heating and melting and perforating the master 8.

  The platen roller 9 is formed integrally with the platen roller shaft through a metal cored bar. The platen roller 9 is rotatable clockwise because both ends of the platen roller shaft are rotatably supported by the plate making side plate pair. The platen roller 9 is connected to a master transport motor 10 as a master transport driving means via a rotation transmission member (not shown) such as a timing belt and a gear, and is thereby driven to rotate clockwise. The master transport motor 10 is composed of, for example, a stepping motor. As described above, when the platen roller 9 is driven to rotate clockwise by the master transport motor 10, the master 8 is pulled out from the master roll 8a.

  The conveying roller pair 13 is provided with an appropriate pressing force applied by an urging means such as a spring and pressed against each other, and both end portions of each roller shaft are rotatably supported by the plate making side plate pair. Thus, they can rotate in opposite directions. The conveyance roller pair 13 is set to rotate at a circumferential speed (conveyance speed) slightly faster than the circumferential speed (conveyance speed) of the platen roller 9 by the rotation transmission member including the master conveyance motor 10. Appropriate front tension is applied to the master 8 while sliding between the two.

  The cutter 12 is a known guillotine type that includes a fixed blade 12b and a movable blade 12a. The cutter 12 is not limited to the guillotine type, and a rotary blade moving type in which the movable blade moves while rotating in the master width direction orthogonal to the master transport direction X1 may be used.

  The drive system around the platen roller 9 and the conveyance roller pair 13 via the master conveyance motor 10 is substantially the same as the rotation transmission mechanism shown in FIG. 2 of Japanese Patent Laid-Open No. 11-77949 proposed by the applicant of the present application, for example. The mechanism is adopted. The plate making unit 15 includes components that constitute plate feeding means capable of transporting and winding the master-made master 8 to the plate cylinder 1. As plate feeding means, a platen roller 9 of the plate making section 15, a conveying roller pair 13, a master guide plate 14, a clamper 7 of the plate cylinder 1 described later, an opening / closing device and a plate as an opening / closing means (not shown) for driving the clamper 7 to open and close. A main motor 20 that rotationally drives the body 1 is included.

  As shown in FIG. 16, in the plate making unit 15, the control target drive means of the plate making unit 15 including the thermal head 11 driven by a thermal head drive circuit (not shown) and the master transport motor 10 is generally made as plate making drive means. 124.

  The plate cylinder 1 has a two-layer structure including a porous and cylindrical support cylinder and a mesh screen (not shown) made of a resin or metal mesh wound around a plurality of layers so as to cover the outer periphery of the support cylinder. Consists of. The plate cylinder 1 is provided with a printable aperture 1a (hereinafter sometimes referred to as an “image forming region”) in which a large number of ink-permeable apertures are formed, a clamper 7 and the like, and cannot be printed. A non-opening portion (hereinafter sometimes referred to as “non-image forming region”) is formed along the rotation direction of the plate cylinder 1 indicated by an arrow in FIG. The image forming area includes a first image area 1A (hereinafter referred to as “front surface area 1A”), an intermediate area 1C, and a second image area 1B (hereinafter referred to as “back surface area 1B”) in the plate cylinder 1 in FIG. ”) At least.

  The plate cylinder 1 is wound around and fixed to an outer peripheral portion of an end plate flange (not shown), and is rotatably supported around a support shaft 5 that also serves as an ink pipe 5 described later. In terms of the embodiment, the size of the plate cylinder 1 is, for example, a size that can be printed on A3 size paper 36 at the maximum during single-sided printing to obtain an A3 size printed matter, that is, A3 size 1 The plate master 8 has a size capable of being wound, its outer diameter is 180 mm (the outer peripheral length of the plate cylinder 1 is about 565 mm), and its width direction (rotation center axis direction) is 350 mm. Is set.

  The plate cylinder 1 is connected to a main motor 20 as a plate cylinder driving means via a drive transmission means such as a gear or a belt (not shown), and is driven to rotate in the direction of the arrow (clockwise) in FIG. The As the main motor 20, for example, a control DC motor is used. An output shaft of the main motor 20 is provided with an optical rotary encoder (not shown) and a plate cylinder sensor (not shown) that sandwiches the optical rotary encoder and generates a pulse by cooperation of the rotary encoder. Yes. This plate cylinder sensor is composed of a transmission type optical sensor (hereinafter simply referred to as “transmission type optical sensor”) having a light emitting part and a light receiving part, and controls the rotational speed (printing speed) of the plate cylinder 1 and the rotational position. It is used for indexing etc.

  Inside the plate cylinder 1 is rotatably supported by a side plate (not shown), and the rotational driving force of the main motor 20 is transmitted by a drive transmission means such as a gear (not shown) so as to be synchronized with the rotation of the plate cylinder 1. An ink roller 2 that is driven to rotate in the direction of the middle arrow (clockwise) and contacts the inner peripheral surface of the plate cylinder 1 to supply ink, and an ink roller 2 that is arranged in parallel with the ink roller 2 with a slight gap therebetween. A doctor roller 3 for forming an ink reservoir 4 having a wedge-shaped cross section and an ink pipe 5 for supplying ink to the ink reservoir 4 are disposed between the two. The ink roller 2, the doctor roller 3, and the ink pipe 5 constitute an ink supply means for supplying ink to the divided master-making master 8X and the master-making master 8Y on the plate cylinder 1, and in this embodiment, the ink supply means is a single ink supply means. It is one thing.

  The ink in the ink reservoir 4 is sucked by an ink pump (not shown) from an ink pack (not shown) provided outside the plate cylinder 1 and supplied from a supply hole of the ink pipe 5 to be kneaded. The ink in the ink reservoir 4 is supplied as a thin film on the outer peripheral surface of the ink roller 2 while being measured by the doctor roller 3, and further, the outer peripheral surface of the ink roller 2 comes into contact with the peripheral surface of the support cylinder in the plate cylinder 1. It is supplied to the opening 1a portion of the plate cylinder 1.

  A portion of the plate cylinder 1 on the outer peripheral surface of the non-opening portion includes a ferromagnetic stage 6 provided along one bus bar of the plate cylinder 1 and clampers provided on both side ends of the stage 6. A clamper 7 having a rubber magnet that is rotatably attached to the shaft and can be opened and closed with respect to the flat surface of the stage 6 is provided. The clamper 7 is opened and closed at a predetermined position by an opening / closing device (not shown) provided on the main body frame side. The plate cylinder 1 is stopped in a state in which the clamper 7 is positioned almost directly as shown in FIG. The plate cylinder 1 is configured as a plate cylinder unit integrally formed with the ink pack, the ink pump, and the like, and is inserted into and removed from the main body frame of the double-sided stencil printing apparatus 300 in the axial direction of the ink pipe 5 (detachment). ) It is free.

  In FIG. 1, on the end plate flange of the plate cylinder 1 on the back side of the paper surface and on the main body frame side in the vicinity of the end plate flange, the rotation position of the plate cylinder 1 is detected as shown in FIG. Components for providing start / trigger information to the sheet feeding motor 37 and the registration motor 41 shown in FIGS. 1 and 12 are arranged. That is, as shown in FIG. 11, on the outer wall of the end plate flange on the back side of the plate cylinder 1, a sheet feeding start light shielding plate 121 and a resist start light shielding plate 122 are on the same circumference of the plate cylinder 1. Are respectively attached to predetermined positions at predetermined intervals.

  On the other hand, on the main body frame side in the vicinity of the light shielding plates 121 and 122, these are opposed to the same circumference of the plate cylinder 1 to which the paper feeding start light shielding plate 121 and the resist start light shielding plate 122 are attached. A sheet feeding registration sensor 120 is attached in a sandwiching manner. The paper feed registration sensor 120 is a transmissive optical sensor.

  In the present embodiment, the home position (initial position) of the plate cylinder 1 is the tip of the divided plate-making master 8X or the plate-making master 8Y conveyed from the plate-making unit 15 with the clamper 7 positioned almost directly above. It is set to the same position as the plate feeding standby position, which is a position for receiving and holding. A light shielding plate for home position (not shown) for detecting the home position of the plate cylinder 1 is attached to a predetermined position of the outer wall of the end plate flange on the back side of the plate cylinder 1. A home position sensor (not shown) is attached to the main body frame side in the vicinity of the home position light shielding plate so as to face the home position light shielding plate of the plate cylinder 1 and sandwich it. The home position sensor is a transmissive optical sensor.

  In FIG. 16, the plate cylinder sensor, the paper feed registration sensor 120, and the home position sensor are collectively referred to as a plate cylinder position detection sensor 29 as a plate cylinder position detection unit that detects the rotational position of the plate cylinder 1.

  A single press roller 21 is disposed near the lower part of the outer peripheral surface of the plate cylinder 1 facing the ink roller 2. The press roller 21 is configured by integrally fixing an elastic body to a metal press roller shaft 21 a and extends in the axial direction of the plate cylinder 1. The press roller 21 is formed so that its lateral width is substantially the same as the lateral width of the plate cylinder 1. As shown in FIGS. 2 to 4, the press roller 21 has a pair of printing arms 22 as pressing means support members disposed on the front side and the back side of the sheet via both end portions of the press roller shaft 21 a. , 22 (the front side of the paper is omitted, and is hereinafter referred to as “a pair of printing pressure arms 22”).

  Each printing pressure arm 22 is disposed with substantially the same shape and the same phase on the front side and the back side of the sheet. Each printing pressure arm 22 is integrated by an arm shaft 22a attached and fixed to a portion in the vicinity of the bent portion and a connection reinforcing member (not shown). A notch 22b that selectively engages with a locking claw 60a of a locking member 60 described later is formed at the lower end of the printing pressure arm 22 shown in the figure. The arm shaft 22a is rotatable by a predetermined angle via a bearing (not shown) between a pair of housing side plates (not shown) fixed on the main body frame side (see the housing side plate pairs 130a and 130b in FIG. 8). It is supported by.

  The press roller 21 is made of, for example, nitrile rubber (NBR) or silicone rubber (Q), which is an oil-resistant elastic body, and at least the outer peripheral surface of the rubber is subjected to a fine uneven surface treatment. The same glass beads as, for example, vitreous fine particles, which are used as a film, for example, for preventing smearing of printed matter in an offset printing machine or the like, are uniformly coated or adhered. Not only glassy fine particles but also ceramic fine particles may be used. As a result, when the outer peripheral surface of the plate cylinder 1 or the divided master-making master 8X or the master-making master 8Y on the plate cylinder 1 comes into contact, or as described later with reference to FIG. 4, the printed image of the surface-printed paper 36a. Swelling and ink stain due to contact with the ink on the surface side are minimized. For example, in the case where the cleaning roller 226 (cleaning means) as shown in FIGS. 17 and 18 is disposed, it is not desired to prevent the remarkable printed matter contamination as described above by vitreous fine particles or ceramic fine particles. If it is good, the outer peripheral surface of the press roller 21 formed of the elastic body having oil resistance is smoothed with a film having ink repellency and oil resistance such as fluoro rubber (FKM) or polytetrafluoroethylene resin. It may be coated.

  The press roller 21 is a divided master-making master 8X or plate-making on the plate cylinder 1 through a printing pressure range varying means 28, a locking means 64 and each printing pressure arm 22 shown in FIGS. The printing position shown in FIGS. 3 and 4 for pressing the unprinted paper 36 and the surface printed paper 36a against the finished master 8Y, and the non-printing position (also the initial position) shown in FIGS. 1 and 2 away from the printing position. It is configured to be freely displaceable between. As described above, the pair of printing arms 22 as the pressing means support members support the press roller 21 as the pressing means so as to be rotatable, and make the press roller 21 contactable / separable with respect to the plate cylinder 1. It is configured to be displaceable. The printing pressure range varying means 28 may also be referred to as a press roller contacting / separating mechanism as pressing means contacting / separating means.

  In FIG. 2, reference numeral 54 denotes a press roller rotation driving unit as a pressing unit driving unit that rotationally drives the press roller 21. The press roller rotation drive means 54 is a press roller drive as a drive means for driving the press roller 21 to rotate in the direction opposite to the rotation direction of the plate cylinder 1 (counterclockwise) at substantially the same peripheral speed as that of the plate cylinder 1. The motor 55 and the driving force transmitting means for transmitting the rotational driving force of the press roller driving motor 55 to the press roller 21 are mainly configured. The press roller drive motor 55 is attached and fixed to the outer wall of the printing pressure arm 22 on the back side in FIG.

  As shown in FIG. 2, the drive force transmission means includes a toothed drive pulley 56 fixed to the output shaft 55a of the press roller drive motor 55, and a press roller protruding further to the back side of the paper surface of the printing pressure arm 22. A toothed driven pulley 57 fixed to the shaft 21a and a toothed endless belt 58 stretched between the driving pulley 56 and the driven pulley 57 are provided.

  The press roller 21 is a press roller driving motor in accordance with the timing when the unprinted paper 36, the front surface printed paper 36a, or the single-side printed paper 36c is pressed against the divided master making master 8X or the master making master 8Y on the plate cylinder 1. 55 is rotationally driven. The operation of the press roller drive motor 55 is controlled by the control device 100 shown in FIG. Control of the rotational speed of the press roller drive motor 55 via the driving force transmission means is performed so that the peripheral speed of the press roller 21 is substantially the same as the peripheral speed of the plate cylinder 1 as described above. According to the example of the present embodiment, since the press roller 21 is rotationally driven by the press roller drive motor 55 at a circumferential speed that is substantially the same as the circumferential speed of the plate cylinder 1, it is possible to obtain a good printed matter with no print image positional deviation. it can.

  Between the printing pressure arms 22, there are a re-feed roller 51 as a re-feed roller member, a roller guide plate 50 as a re-feed guide member, etc., in addition to the press roller 21 constituting the re-feed means 45. It is arranged. That is, the paper re-feeding means 45 temporarily holds the front-side printed paper 36a on which the print image is formed by the printing unit 16, and then the front-side printed paper 36a is pressed against the press roller 21 and the re-feed roller. 51 is fed to the plate cylinder 1 by holding the sheet refeeding and conveying device 104 sent out at a predetermined timing and the surface printed paper 36a sent out by the sheet refeeding and conveying device 104 on the outer peripheral surface thereof. The press roller 21 that rotates and conveys, the refeed roller 51 provided in contact with the outer peripheral surface of the press roller 21 on the lower side of the press roller 21, and the press roller 21 adjacent to the outer peripheral surface of the press roller 21 on the right side. And a curved roller guide plate 50 provided mainly.

  As shown in FIGS. 1 to 4, the refeed conveyance device 104 is disposed below the reciprocating path of the movement guide 81 and in the vicinity of the left side of the refeed roller 51. As shown in detail in FIGS. 2 to 4, the refeed conveyance device 104 is provided integrally with the drive shaft 107 a and a refeed housing 110 that rotatably supports a drive shaft 107 a and a driven shaft 106 a described later. A rear roller 107 serving as a drive roller, and a driven roller provided integrally with a driven shaft 106a disposed upstream of the drive shaft 107a in the paper transport direction X and in the vicinity of the refeed roller 51. As an endless belt that holds and conveys the surface-printed paper 36a that is wound and stretched between the front conveyance roller 106, the rear conveyance roller 107, and the front conveyance roller 106, and is delivered from the moving guide 81. A conveying belt 108 formed with a plurality of holes (not shown) for air suction and a driving shaft 107a are connected to the driving shaft 107a via a driving force transmission means such as a gear or a belt. A belt driving motor 105 as a belt driving means for rotating the conveying belt 108 through rotation driving, and the surface printed sheet 36a delivered from the moving guide 81 sucks air from the plurality of holes to convey the conveying belt 108. And a suction fan 109 for adsorbing and holding on the upper surface side.

  The re-feeding casing 110 is formed so that its upper surface is open and its width is slightly smaller than the interval between the printing pressure arms 22, and has a substantially U-shaped side section. The bottom wall of the refeed housing 110 is formed with a number of holes or slits (not shown) for letting the air flow from the suction fan 109 escape downward. The re-feeding casing 110 has bearings (not shown) on both the upstream and downstream sides in the sheet conveying direction, and these bearings rotatably support the drive shaft 107a and the driven shaft 106a, respectively. Yes. Both ends of the drive shaft 107a penetrate both side surfaces of the refeed housing 110, and both ends of the penetrated drive shaft 107a can be rotated by a bearing member (not shown) provided on the main body frame. It is supported.

  A drive gear (not shown) is attached to one end of the drive shaft 107a (for example, the back side of the paper surface in FIGS. 2 to 4). Driven by rotation. The conveyor belt 108 is intermittently rotated clockwise at a predetermined timing as described later by the operation of the belt drive motor 105 based on the command signal from the control device 100 shown in FIG. The belt drive motor 105 is fixedly provided on the main body frame side. Both ends of the driven shaft 37a are configured not to penetrate both side surfaces of the refeed housing 110.

  Boss 111 is integrally provided on both outer sides of the upstream end in the paper transport direction X in the paper refeed housing 110, and each boss 111 is formed on each printing pressure arm 22 (not shown). Each of the long hole-shaped escape holes is loosely fitted. With this configuration, the re-feeding housing 110 is driven by the swing of each printing pressure arm 22 when the press roller 21 is brought into contact with or separated from the plate cylinder 1 by a printing pressure range changing unit 28 described later. Oscillation around 107a is possible.

  As shown in FIGS. 2 to 4, the surface-printed paper 36 a is transferred to the outer peripheral surface of the press roller 21 and the refeed roller 51 by the transport belt 108 at the upstream end in the paper transport direction X in the refeed housing 110. A re-feed sensor 52 as a surface printed paper detecting means for detecting that the rear end of the surface printed paper 36a is temporarily held at a predetermined position near the press roller 21 when being conveyed between It is arranged. The re-feed sensor 52 includes a reflection type optical sensor, and includes a rear end (the right end of the front surface printed paper 36a shown in FIG. 4) and a front end (the left end of the front surface printed paper 36a shown in FIG. 4). ).

  The conveying roller rear 107 and the conveying roller front 106 are divided into skewers, are formed of, for example, a toothed roller, and are formed of a high friction material. Incidentally, it is desirable to form the post-conveyance roller 107 and the pre-conveyance roller 106 with a high friction material having oil resistance (ink corrosion resistance) such as nitrile rubber (NBR) or an appropriate resin. The conveyor belt 108 is formed of, for example, a toothed belt, and a plurality of belts are wound and stretched between a conveyor roller rear 107 and a conveyor roller front 106 which are divided into skewers. Incidentally, the conveyor belt 108 is desirably formed of an elastic body having oil resistance (ink corrosion resistance) such as nitrile rubber (NBR) or silicone rubber (Q).

  The suction fan 109 sucks the surface-printed paper 36 a delivered from the movement guide 81 to the upper surface side of the transport belt 108 by sucking air from the plurality of holes formed in the transport belt 108. A fan drive motor is incorporated as fan drive means for rotationally driving 109. Hereinafter, the fan drive motor is simply referred to as “suction fan 109”.

  As shown in FIG. 4, the re-feed roller 51 is a front-side print that is transported by the transport belt 108 after the surface-printed paper 36 a is temporarily sucked and held on the transport belt 108 of the re-feed transport device 105. The used paper 36 a is pressed between the outer peripheral surfaces of the press roller 21 and has a function of driven rotation and conveyance. The re-feed roller 51 is composed of a plurality of rollers divided into skewers, and is formed integrally with the shaft 51a. The re-feed roller 51 is disposed on the lower side of the press roller 21 so that the outer peripheral surface thereof is in pressure contact with the outer peripheral surface of the press roller 21, and both end portions of the shaft 51 a are rotatable between the printing pressure arms 22. By being supported, it receives the rotational force of the press roller 21 and is driven to rotate in the opposite direction (clockwise) to the rotation direction (counterclockwise) of the press roller 21.

  The roller guide plate 50 has a function of guiding the surface-printed paper 36 a conveyed by the rotational force of the press roller 21 toward the plate cylinder 1 by contacting the outer peripheral surface of the press roller 21. The roller guide plate 50 has a curved partial cylindrical shape centered on the press roller shaft 21a in order to guide the surface-printed paper 36a along the outer peripheral surface of the press roller 21. Are fixed between the printing pressure arms 22. The guide surface side of the surface-printed paper 36a on the roller guide plate 50 has a low coefficient of friction with respect to the surface-printed paper 36a and a smooth coating film having ink repellency and oil resistance such as polytetrafluoroethylene resin. It is coated.

  In FIG. 16, the control target drive means of the refeed means 45 includes a press roller drive motor 55, a belt drive motor 105, a suction fan 109, and the like. Various detection means of the paper refeed means 45 include a paper refeed sensor 52 and the like.

  Next, the configuration around the printing pressure range variable means 28 that determines the printing pressure range of the press roller 21 will be described in detail. In the present embodiment, as shown in FIGS. 1 and 10, a first printing pressure range pattern that applies printing pressure only to the surface area 1 </ b> A corresponding to the surface plate-making image 8 </ b> A in the divided plate-making master 8 </ b> X on the plate cylinder 1. And a printing pressure range pattern as a second printing pressure range pattern that applies printing pressure only to the back surface area 1B corresponding to the back plate making image 8B in the divided plate-making master 8X on the plate cylinder 1. II and a printing pressure range as a third printing pressure range pattern that applies a printing pressure from the front surface area 1A to the back surface area 1B corresponding to the single-side plate-making image 8YA in the plate-making master 8Y on the plate cylinder 1. One of at least three printing pressure range patterns with the pattern III can be selectively switched. A part of the mechanism relating to the printing pressure range varying means 28 for selectively switching one of these three printing pressure range patterns is shown in FIGS. The printing pressure range varying means 28 also has a configuration / function for displacing the press roller 21 between the printing position and the non-printing position.

  The printing pressure range variable means 28 includes a multi-stage cam (43), a step cam (49), and a stepping motor that rotationally drives the step cam (49) shown in FIGS. (52) etc. It is the structure similar to the press roller contacting / separating mechanism (55). Incidentally, in FIG. 2 and FIG. 3, the printing pressure range varying means 28 is composed of components such as a multi-stage cam (43), a step cam (49), and a stepping motor (52) that constitute the press roller contact / separation mechanism (55). A part of the above-mentioned arm shaft 22a, the above-described printing pressure arm pair 22, a pair of cam followers 241, 241 (hereinafter referred to as "a pair of cam followers 241"). A pair of printing springs 242 and 242 (hereinafter referred to as “a pair of printing springs 242”), a printing pressure cam shaft 244 and a pair of multistage cams 243 and 243 (hereinafter referred to as “a pair of multistage cams 243”). And the like). The stepping motor 252 is shown only in the printing pressure range variable means 28 shown in FIG.

  As shown in FIGS. 2 and 3, each of the components constituting the printing pressure range varying means 28 basically applies a uniform pressing force of the press roller 21 to the outer peripheral surface of the plate cylinder 1. Since the press roller 21 is disposed on the front side and the back side of the paper as viewed from FIG. 1 (the front side of the paper is omitted), the components on the back side of the paper will be described as a representative. Therefore, the description on the front side of the sheet is omitted. If the printing pressure range variable means 28 does not need the advantages as described above, the components constituting the printing pressure range variable means 28 may be, for example, the back of the paper surface of FIGS. Of course, it may be arranged only on the side.

As shown in FIGS. 2 and 3, a cam follower 241 is pivotally mounted on the outer wall at the center of the printing pressure arm 22 facing the inside of the printing pressure arm 22 on which the press roller 21 is supported. Is held. The cam follower 241 is configured by a rolling bearing so that the cam follower 241 can contact the multistage cam 243 with reduced frictional resistance.
One end of a printing spring 242 (tensile spring) that constantly urges the press roller 21 in a direction in which it presses against the outer peripheral surface of the plate cylinder 1 is locked to the other end of the printing pressure arm 22. The other end is locked to the housing side plate side. By this printing pressure spring 242, the other end side of the printing pressure arm 22 is oscillated clockwise around the arm shaft 22 a and is urged in a direction in which the press roller 21 is pressed against the outer peripheral surface of the plate cylinder 1. A notch 22b that can be engaged with a locking claw 60a of a locking member 60, which will be described later, is integrally formed at the other end of the printing pressure arm 22, and can be engaged with and disengaged from the locking member 60. .

  On the other hand, a printing pressure cam shaft 244, to which a pair of multi-stage cams 243 rotating in synchronization with the rotation of the plate cylinder 1 is fixed, is rotatably supported on the respective housing side plates near the respective cam followers 241. The multistage cam 243 is composed of, for example, a plate cam in which a small diameter portion (concave portion) and a large diameter portion (convex portion) are formed.

A belt pulley or gear (not shown) is fixed to the printing cam shaft 244, and is connected to the main motor 20 via a drive transmission means such as a belt or gear (not shown). The plate cylinder 1 rotates in synchronization with the rotation of the plate cylinder 1. The cam follower 241 is urged by the above-described printing pressure spring 242 so as to always come into contact with the multistage cam 243. Therefore, the cam driving means for rotationally driving the multistage cam 243 is mainly composed of the main motor 20.
Each multistage cam 243 has three cam plates 243A, 243B, and 243C, which are fixed to the printing cam shaft 244 at an appropriate interval. The cam plates 243A, 243B, and 243C are arranged in the order of the cam plate 243B, the cam plate 243A, and the cam plate 243C from the front side of the sheet of FIG. 2 and FIG. Each of the cam plates 243A, 243B, and 243C has a small-diameter portion (concave portion or base portion) that is a disc concentric with the cam shaft 244, and a large-diameter portion (convex portion) having the same protruding amount. The multistage cam 243 is a camshaft 244, that is, a drive gear (45) attached to the camshaft (44) shown in FIG. The rotational force from the plate cylinder driving means (121), that is, the main motor 20, is transmitted through the transmission gear (47) attached to the shaft (46), and is driven to rotate clockwise in FIG.
The press roller 21 has a non-printing position shown in FIG. 2 in which the peripheral surface is separated from the outer peripheral surface of the plate cylinder 1 when any one of the large diameter portions of the cam plates 243A, 243B, 243C contacts the cam follower 241. 3 and 4 in which the peripheral surface is pressed against the outer peripheral surface of the plate cylinder 1 by the urging force of the printing pressure spring 242 when the contact between any of the large diameter portions and the cam follower 241 is released. Occupy position. Each of the cam plates 243A, 243B, and 243C is configured so that the small diameter portion (base portion) and the cam follower 241 do not come into contact with each other when the press roller 21 occupies the printing position.
The shape of the large diameter portion of each cam plate 243A, 243B, 243C is such that the contact range between the press roller 21 and the plate cylinder 1 is such that the surface region 1A, the intermediate region 1C and the back surface region 1B shown in FIG. The cam plate 243B has the same range as the surface region 1A (see the printing pressure range pattern I shown in FIG. 10) so that all the ranges are combined (see the printing pressure range pattern III shown in FIG. 10). The cam plate 243C is formed to have the same range as that of the back surface region 1B (see the printing pressure range pattern II shown in FIG. 10).

  2 and 3, reference numeral 64 indicates a locking means for holding the press roller 21 in the non-printing position shown in FIGS. 1 and 2 except when paper is passed. The locking means 64 is sometimes referred to as a printing pressure releasing means, and is mainly composed of a locking member 60, a support shaft 61, a solenoid 62, and a tension spring 63. The locking means 64 is disposed on the back side of the page.

  The locking member 60 is swingably supported around a support shaft 61 planted on the housing side plate on the back side of the paper surface. One end of the locking member 60 is selected with the notch 22b of the printing pressure arm 22 described above. An engaging claw 60a is formed to engage with each other. The other end of the locking member 60 is locked with one end of a tension spring 63 that urges the engaging claw 60a to always engage with the notch 22b of the printing pressure arm 22. The other end of the tension spring 63 is locked to the housing side plate side on the back side of the drawing. Further, on the side of the other end portion of the locking member 60 facing the arrangement portion of the tension spring 63, a plunger 62a of a solenoid 62 fixed to the casing side plate on the back side of the paper surface via a bracket (not shown) has a pin. Are connected through. The solenoid 62 uses a pull type.

  As described above, when the solenoid 62 is energized and the solenoid 62 is turned on, the printing pressure range variable means 28 is operated, and the press roller 21 occupies the printing position through the operation described later. As a result, the press roller 21 continuously presses the paper 36 while rotating it on the divided master-making master 8X or the master-making master 8Y on the plate cylinder 1. When the energization of the solenoid 62 is interrupted and the solenoid 62 is turned off, the printing pressure range variable means 28 is deactivated, and the press roller 21 is separated from the printing position through the operation described later. 2 occupies the non-printing position (initial position).

  The solenoid 62 is on / off controlled by a control device 100 described later. By the on / off switching control of the solenoid 62 by the control device 100, the state is selectively switched between a state in which the printing pressure arm 22 is held and a state in which the holding is released. As will be described later, the solenoid 62 is turned on when the cam follower 241 is in contact with the large diameter portion of the multistage cam 243 (see FIG. 2).

  FIG. 10 is an expanded view of the printing pressure range of the press roller 21 for easy understanding. In FIG. 10, an area portion of the front plate-making image 8A and an area portion of the back-side plate-making image 8B are formed on the divided plate-making master 8X wound around the opening 1a on the plate cylinder 1 (not shown). In addition, there is an unfinished blank intermediate unmade region 8C between them. Here, the leading side of the divided pre-printed master 8X, which is also called the leading edge blank portion sandwiched and fixed by the clamper 7 of the plate cylinder 1 (not shown in FIG. 10), is the left end side.

  The printing pressure range pattern for normal printing including single-sided printing is as shown in III. That is, the printing pressure range pattern III is applied to one side of the prepressed master 8Y by applying a printing pressure from the area portion of the front plate making image 8A to the area portion of the back plate making image 8B through the intermediate non-plate making area 8C. The cam plate 243A is selected by operating the printing pressure range varying means 28 in response to a command from the control device 100 shown in FIG. 16 so that the paper 36 is continuously pressed against the plate-making image 8YA, and the cam plate 243A is selected. Is rotated so that the small diameter portion thereof faces the cam follower 241.

  At the time of front side printing, the printing pressure range variable means 28 is operated in accordance with a command from the control device 100 so as to be printed corresponding to the area portion of the front plate-making image 8A as shown in the printing pressure range pattern I. Thus, the cam plate 243B is selected, and the cam plate 243B is rotationally driven so that the small diameter portion of the cam plate 243B faces the cam follower 241 and then the printing pressure is released in the intermediate unmade region 8C.

At the time of printing on the back side, the printing pressure range pattern II is obtained, and the cam plate 243C is selected by the operation of the printing pressure range varying means 28 in response to a command from the control device 100, so that the region portion of the first front plate-making image 8A is selected. Then, in order to release the printing pressure, the cam plate 243C is rotationally driven so that the large diameter portion of the cam plate 243C faces the cam follower 241 and then the small diameter portion of the cam plate 243C faces the cam follower 241.
According to the present embodiment, since the printing pressure range variable means 28 is provided, the printing pressure on range is optimally set, and the printing pressure is turned on when there is no sheet and the press roller 21 It is possible to prevent a problem that the printed image is transferred to the outer peripheral surface and is stained with ink.

The printing pressure range variable means 28 includes the multistage cam (43), the step cam (49), and the press roller contact / separation mechanism (55) shown in FIGS. 2 and 4 of JP-A-2003-200355 as described above. For example, a pair of cam followers (41), a pair of printing pressure springs 42, and a pressure release cam assembly (43) shown in FIGS. 2 to 6 of JP-A-2003-266906 are included. In addition, a printing pressure range variable means (55) including a cam home position sensor (54), a pressure release cam switching motor (53), and the like may be employed.
Further, as a specific example of the printing pressure range variable means, in addition to the above-described configuration, for example, by applying the technique disclosed in Japanese Utility Model Publication No. 5-45500, for example, Japanese Patent Application Laid-Open No. 64-18683 By applying a cam plate set composed of a plurality of cams movable by a screw shaft as disclosed in FIGS. 7 and 8 and a printing cam switching motor for rotationally driving the screw shaft, etc. For example, an application of a swinging mechanism of a pressing member and a pressing range variable mechanism capable of selecting a multistage cam as disclosed in FIGS. 7 and 8 of JP-A-10-193767, and for example, JP-A-2003-237030 1 to 4 of the gazette may be applied to the emergency pressing release means (79).

  As shown in FIG. 1, the paper discharge unit 19 is provided so as to be close to the outer peripheral surface of the plate cylinder 1, and a peeling claw 170 that peels the single-side printed paper 36 c from the plate-making master 8 </ b> Y on the plate cylinder 1. A separation fan 171 for blowing air between the front end portion of the single-side printed paper 36c separated by the nail 170 and the plate cylinder 1 to assist the separation action by the separation nail 170, and separation by the separation nail 170 and the separation fan 171. The paper discharge conveyance device 152 that conveys one of the printed single-sided printed paper 36c and the double-sided printed paper 36b while sucking, and the discharge tray 172 described above are mainly configured.

  The peeling claw 170 is provided in the vicinity of the downstream in the printing nip portion formed when the press roller 21 is pressed against the outer peripheral surface of the plate cylinder 1. The peeling claw 170 is close to the outer peripheral surface of the plate cylinder 1 on the plate cylinder 1 by a peeling claw displacing means (not shown) having a cam and a spring that are driven to rotate in synchronization with the rotation of the plate cylinder 1. A separation position for forcibly separating the single-side printed paper 36c from the pre-printed master 8Y, and a non-peeling position for avoiding contact with the clamper 7 arrangement portion protruding from the outer peripheral surface of the plate cylinder 1 apart from the separation position It is configured to be freely displaceable between. The peeling fan 171 has a built-in fan drive motor that rotationally drives the peeling fan.

  As shown in FIGS. 1 to 4, the paper discharge conveyance device 152 is disposed below the peeling claw 170 and on the left side of the switching guide 46. The paper discharge roller rear 154 as a driving roller, a driven roller The sheet discharge roller front 156, a sheet discharge belt 158 which is an endless belt, a suction fan 159, and the like are provided. A plurality of post-discharge rollers 154 have a roller shape and are attached to a drive shaft 154a rotatably supported by the pair of casing side plates at a predetermined interval. A plurality of front discharge rollers 156 are also provided on the driven shaft 156a rotatably supported by the casing side plate pair at equal intervals with the rear 154 of each discharge roller. A paper discharge belt 158 is stretched around each paper discharge roller 154 and each paper discharge roller front 156 corresponding thereto. A drive gear or a drive pulley (not shown) is attached to the drive shaft 154a (for example, the back side of the paper surface of FIGS. 1 to 4), and a motor gear (not shown) that meshes with the drive gear or between the drive pulley and the pulley (not shown). It is connected to a paper discharge belt drive motor 153 via a driving force transmission means such as a stretched belt. As a result, the paper discharge belt 158 is rotationally driven by the paper discharge belt drive motor 153 in the direction of the arrow (counterclockwise) shown in FIG.

  A suction fan 159 is disposed below the discharge roller 154, the discharge roller front 156, and the discharge belt 158. The suction fan 159 has a built-in fan drive motor that rotationally drives the suction fan. The paper discharge conveyance device 152 sucks either the single-side printed paper 36c or the double-side printed paper 36b onto each paper discharge belt 158 by the suction force of the suction fan 159, and rotates the rear 154 after each paper discharge roller. 1 in the direction of arrow

  In FIG. 16, the control target drive means of the paper discharge unit 19 including the fan drive motor of the peeling fan 171, the paper discharge belt drive motor 153, and the fan drive motor of the suction fan 159 in the paper discharge unit 19 is discharged in a general manner. The driving means 127 is used.

  As shown in FIGS. 1 to 4, the switching guide 46 includes a printing nip portion 16 a serving as a print image forming portion in the printing portion 16 formed by pressing the press roller 21 against the plate cylinder 1 and paper discharge. It is disposed on a paper conveyance path to and from the conveyance device 152. The switching guide 46 is made of a plate material having substantially the same width as the plate cylinder 1 and the press roller 21, and its base end portion (downstream end portion in the paper transport direction X) is supported by the casing side plate so as to be rotatable by a predetermined angle. The free end portion (the upstream end portion in the paper transport direction X) is swingable about the shaft 46a. The outer peripheral surface of the switching guide 46 may be smoothly coated with a film having ink repellency and oil resistance, such as polytetrafluoroethylene resin.

  The switching guide 46 has a free end portion formed in an acute angle section when a solenoid 47 as a switching drive means shown in FIGS. 2 and 16 operates against a biasing force of a tension spring as a biasing means (not shown). Are selectively positioned at a first displacement position indicated by a solid line and a second displacement position indicated by a two-dot chain line in FIG. The switching guide 46 is usually given the habit of swinging by the urging force of the tension spring at the first displacement position which is also the initial position shown in FIG. When the switching guide 46 occupies the first displacement position, the tip of the switching guide 46 comes close to the outer peripheral surface of the press roller 21 and does not interfere with the clamper 7 on the plate cylinder 1 and occupies the second displacement position. The tip of the plate cylinder 1 is placed close to the peripheral surface of the plate cylinder 1. The double-side printed paper 36b or the single-side printed paper 36c that has passed between the plate cylinder 1 and the press roller 21 is guided to the paper discharge unit 6 when the switching guide 46 occupies the first displacement position, The printed sheet 36a is delivered to the moving guide 81 while being guided by the switching guide 46 when the switching guide 46 occupies the second displacement position. The switching drive means for displacing the switching guide 46 between the first displacement position and the second displacement position is not limited to the combination of the solenoid 47 and the tension spring, and is driven by, for example, a stepping motor or a rotary solenoid. It may be.

  As shown in FIGS. 1 to 4, the moving guide 81 is disposed between the discharge conveyance device 152 and the switching guide 46 and the refeed conveyance device 104. As shown in FIGS. 3, 8, and 9, the movement guide 81 has a first end near the printing unit 16 at the front end of the front-side printed paper 36 a fed from the printing nip portion 16 a at the substantially central portion in the paper width direction Y. The front-side printed paper 36a at the initial position P2 as the second position in the vicinity of the upstream side of the refeeding unit 45 lower than the movement position P1 as shown in FIGS. It has a function and configuration as a sheet clamping means for opening the front end of the paper.

  As shown in FIGS. 1 to 6, 8, and 9, the movement guide 81 includes a sandwiching base 81 f that sandwiches and places the leading end of the surface-printed paper 36 a, and surface printing sent from the printing nip portion 16 a. An end fence 81d having a sheet contact surface 81e that is integrally formed with the holding table 81f downstream of the sheet advance direction Xa of the used sheet 36a and that contacts the front end of the surface-printed sheet 36a, and a sheet surface of the holding table 81f. A pair of protrusions 81c integrally formed in a reciprocating direction and a pair of protrusions 81c integrally formed on both front and rear side ends, and a front end of a substantially central portion in the sheet width direction Y of the surface-printed sheet 36a. A single clamping claw 81b as a clamping member that can be opened and closed with respect to a clamping table 81f that grips and clamps the distal end including it, and a swingable movement that attaches and fixes the base end of the clamping claw 81b ( Clamp shaft 81a having a constant angle rotation) and a pair of bearing brackets 81g shown only in FIG. 8 that are integrally attached to both side ends of a clamping table 81f for supporting the clamp shaft 81a so as to be rotatable by a predetermined angle. And a torsion coil spring (not shown) as an urging means for urging the free end of the clamp claw 81b against the upper surface of the clamping base 81f in the direction shown by the arrow in FIG. 4 and the clamp shaft 81a are loosened so as to be rotatable by a predetermined angle. A plurality of guides 81h having a trapezoidal shape when viewed from the front with the base fixed to the end fence 81d, and a pair of upper and lower release levers 82 shown in FIG. 9 attached and fixed to the back side of the paper surface of the clamp shaft 81a. The upper part is mainly composed of the lower part 83 and the lower part of the release lever.

The movement guide 81 is formed in a substantially L-shaped cross section by a clamping table 81f and an end fence 81d. The four protrusions 81c are loosely fitted in the guide grooves 88 formed in the housing side plate pairs 130a and 130b shown in FIG. The clamp claw 81b is inclined with an acute rising angle with respect to the paper traveling direction Xa (conveying direction) of the surface-printed paper 36a fed from the printing nip portion 16a, and its base end is attached and fixed to the clamp shaft 81a. The free end is formed into an acute angle. In addition, the clamp claw 81b is provided at the center portion of the clamp shaft 81a in the sheet width direction Y so as to clamp and grip the front end of the substantially center portion in the sheet width direction Y of the surface-printed sheet 36a fed from the printing nip portion 16a. It consists of a thin plate member made of metal or resin having a predetermined width (approximately 10 to 30 mm in width) in the same width direction Y. A mounting portion 84 shown in FIG. 8 is integrally provided at a lower portion of the clamping table 81 f on the back side of the paper surface, and the mounting portion 84 is fixed to a timing belt 89 that constitutes the moving means 87.
As shown in detail in FIGS. 5 and 6, the guide 81h includes an inclined surface 81ha inclined in the paper traveling direction Xa. The inclined surface 81ha is mainly fed from the printing nip portion 16a and proceeds in the paper traveling direction Xa. A function of guiding the front end of the surface-printed paper 36a to pass between the free end of the clamp claw 81b and the upper surface of the clamping base 81f so as to contact the paper contact surface 81e below the end fence 81d; A function of pressing the front end of the surface-printed paper 36a after coming into contact with the surface 81e so as not to be lifted, and a surface-printed that has been clamped by vibration or vibration of the clamp shaft 81a when the moving guide 81 is stopped or reciprocated. It has a function of preventing the position of the leading edge of the paper 36a from fluctuating.
For the purpose of disposing the guide 81h having the above three functions, in the present embodiment, two positions are provided at positions that are symmetrical with respect to the paper width direction Y with respect to the clamp claw 81b. You may arrange | position in this position.
The release lever 82 and the release lever lower 83 are formed of a plate-like member. Note that the protrusion 81c is not limited to being formed integrally with the holding base 81f, but may be formed of a roller that can roll on the inner wall of the guide groove 88 with little frictional resistance.

Here, for example, in the case where a plurality of clamp claws 81b (clamping members) are arranged in the paper width direction Y of the clamp shaft 81a, the opening timing of the plurality of clamp claws 81b when opening the front end portion of the front surface printed paper 36a. Are not the same, the separation of the plurality of clamp claws 81b from the clamping portion at the front end of the front surface printed paper 36a is locally different, and the load on the front surface printed paper 36a fluctuates and skews. It becomes easy to generate troubles such as being distorted. Therefore, the adjustment for making the release timings of the plurality of clamp claws 81b the same is troublesome, or the plurality of clamp claws 81b are worn as they are used several times, so that successive readjustments are necessary. There were problems such as becoming.
However, according to the movement guide 81 of the present embodiment, as described above, the clamp claw 81b pinches and grips the front end of the substantially center portion in the paper width direction Y of the surface-printed paper 36a fed from the printing nip portion 16a. Accordingly, since the single clamp portion 81b is disposed at the center of the clamp shaft 81a in the sheet width direction Y, for example, a plurality of clamp claws 81b are disposed in the sheet width direction Y of the clamp shaft 81a. In the operation example 2, when the front end of the front surface printed paper 36a is opened at the initial position P2 and delivered to the refeed conveyance device 104, there is a single point for opening the front end of the front surface printed paper 36a. For example, the release timing of the clamp claws 81b (clamping members) arranged on the left and right sides is shifted, and the load on the surface-printed paper 36a fluctuates. As a result, problems such as skewing and distortion do not occur, and printing position deviation due to skewing and meandering of the surface-printed paper 36a in the refeed conveyance device 104 is suppressed, which is good. It is possible to perform good printing in a proper paper posture state. In addition, the wear of the plurality of clamp claws 81b and the adjustment of the holding / pressing force of the surface-printed paper 36a by the plurality of clamp claws 81b are unnecessary, and the apparatus can be configured at low cost.
Further, by providing the clamp claw 81b inclined with an acute rising angle with respect to the paper traveling direction Xa of the front surface printed paper 36a sent out from the printing nip portion 16a, the front surface printed paper 36a can be conveyed. When a load or the like is applied in the direction in which the front-side printed paper 36a is pulled out, a direction that increases the clamping force (pressing force), that is, a moment that rotates the clamp claw 81b counterclockwise acts. ) To prevent the sheet 36a from coming off, and the clamping force as the urging force of a torsion coil spring (not shown) can be set small, and there is an advantage that it can be constructed inexpensively without having to be made firmly.
It should be noted that the portion of the moving guide 81 that contacts the surface-printed paper 36a is formed of a metal material having an antistatic action, or subjected to an evaporation process or a plating process having an antistatic action. Is more preferable.

  As shown in FIG. 8, the moving means 87 is disposed outside the casing side plate 130b on the back side of the page, and has a function and configuration for reciprocating the moving guide 81 between the moving position P1 and the initial position P2. Have The moving means 87 is formed so as to incline to the lower left so as to be substantially the same as the transport dropping path in the paper traveling direction Xa (transport direction) of the front surface printed paper 36a and penetrate the housing side plate pair 130a, 130b. An arcuate guide groove 88 and a toothed drive pulley 90 rotatably supported with a shaft 90a on a housing side plate 130b in the guide groove 88 in the vicinity of the downstream end in the paper traveling direction Xa of the surface-printed paper 36a. A toothed driven pulley 91 having a shaft 91a rotatably supported by a housing side plate 130b in the guide groove 88 near the upstream end in the paper traveling direction Xa of the front surface printed paper 36a, and a drive pulley 90 The timing belt 89 is stretched between the driven pulley 91 and stretched, and the housing side plate 130b is not shown so as to abut against the timing belt 89 and apply tension thereto. A plurality of tension rollers 95 supported rotatably with a shaft, a drive gear 92 attached and fixed to the shaft 90a of the drive pulley 90, and a housing side plate 130b in the vicinity of the shaft 90a of the drive pulley 90 It is mainly composed of a drive motor 94 as a fixed forward / reverse drive means, and a motor gear 93 that is attached and fixed to the output shaft 94a of the drive motor 94 and meshes with the drive gear 92.

  The timing belt 89 is connected and fixed to the moving guide 81 via an attachment portion 84 formed integrally with the lower portion of the holding base 81 f of the moving guide 81. The drive motor 94 is composed of a stepping motor, for example. As described above, the driving motor 94 is the driving means of the moving means 87, the guide groove 88 is the guiding means of the moving means 87, and the timing belt 89, the driving pulley 90, the driven pulley 91, the driving gear 92, and the motor gear 93 are the driving motor 94. The driving force transmission means for transmitting the driving force to the movement guide 81 is configured.

  As shown in FIG. 3, FIG. 8, FIG. 9 and FIG. 9 in which the moving guide 81 clamps the leading end of the front surface printed paper 36a through the driving force transmitting means by forward / reverse driving of the driving motor 94, as shown by the solid line in FIG. In the vicinity of the movement position P1 (first position) that is in the vicinity of the printing unit 16 and in the vicinity of the upstream side of the refeeding means 45 that is lower than the movement position P1 (in the vicinity of the rear upper portion of the conveyance roller 107 of the refeeding conveyance device 104). In order to selectively occupy the initial position or the standby position (second position) indicated by a solid line in FIGS. 1 and 2 and a two-dot chain line in FIGS. Reciprocates. In the vicinity of the drive pulley 90, a home position sensor 85 is provided for detecting when the movement guide 81 occupies the second position, which is the home position P2 (initial position P2).

  As shown in FIG. 9, the release cam 98 and the torsion coil spring come into contact with the lower release lever 83 of the movement guide 81 when the movement guide 81 occupies the movement position P <b> 1 indicated by the solid line, thereby the torsion coil spring. The clamp claw 81b is swung clockwise (turned by a predetermined angle) via the release lever 83 and the clamp shaft 81a against the urging force, and once opened, the movement guide 81 is moved from the movement position P1. When the movement starts toward the initial position P2 indicated by the chain line, the contact state with the lower release lever 83 is released, and the clamping claw 81b is swung counterclockwise by the biasing force of the torsion coil spring. Thus, it has a function as an operation timing control means for operating so as to sandwich the leading end of the front surface printed paper 36a. As shown in FIG. 9, when the movement guide 81 occupies the initial position P2, the release pin 99 abuts against the release lever upper 82 of the movement guide 81 to resist the biasing force of a torsion coil spring (not shown). It has a function as an operation timing control unit that operates to swing the clamp claw 81b clockwise via the release lever upper 82 and the clamp shaft 81a to open the front end of the surface-printed paper 36a.

  According to the present embodiment, the provision of the release cam 98 has the following advantages over the case where the release cam 98 is not provided. That is, for example, when the movement guide 81 occupies the movement position P1, the front end of the surface-printed paper 36a overcomes the urging force of a torsion coil spring (not shown) by the conveying force applied by the printing nip portion 16a and rotates the clamp pawl 81b clockwise. If the release cam 98 is removed so as to be inserted into the open part (the open part between the tip of the clamp claw 81b and the upper surface of the clamping table 81f), the Even if the urging force of the torsion coil spring is set according to a sheet with low stiffness, it is assumed that the leading end of the sheet is deformed or the sheet clamping force becomes unstable. On the other hand, according to the present embodiment, when the movement guide 81 occupies the movement position P1, the front end of the surface printed paper 36a is conveyed by the printing nip portion 16a by the action of the release cam 98 described above. Because it is smoothly inserted into the open part (open part between the tip of the clamp claw 81b and the upper surface of the clamping table 81f) by force, the surface printed paper is not affected by the strength of the paper. The tip of 36a can be securely clamped and clamped between the tip of the clamp claw 81b and the upper surface of the clamping table 81f, so that the surface-printed paper 36a is in a stable state without meandering or skewing. Can be transported satisfactorily at the same time, and the printing image can be prevented from tilting when printing on the back side, or the resist can be prevented from deteriorating due to tilting. It is. In addition, the opening time when the front end of the surface-printed paper 36a is clamped can be set to a certain extent by devising and adjusting the shape of the release cam. This can be performed without resistance, and the front end of the surface-printed paper 36a can be favorably clamped.

  By the action and action of the release pin 99, when the movement guide 81 occupies the initial position P2, the front end portion of the surface-printed paper 36a held between the front end of the clamp claw 81b and the upper surface of the holding base 81f is released. The front surface printed paper 36a falls from the rear end thereof onto the conveyance belt 108 of the refeed conveyance apparatus 104, and is temporarily sucked and held on the conveyance belt 108 by the suction force of the suction fan 109 operating at this time. After that, it is conveyed by the rotational drive of the conveyor belt 108. Needless to say, the length of the transport belt 108 and the initial position P2 of the moving guide 81 are set to have optimum lengths depending on the length of the paper 36 used for duplex printing in the paper transport direction X. .

  The plate removal unit 17 includes an upper plate removal member 160, a lower plate removal member 161, a plate removal box 162, a compression plate 163, and the like. The upper plate removal member 160 includes a driving roller 164, a driven roller 165, an endless belt 166, and the like. The drive roller 164 is rotationally driven in the clockwise direction of FIG. 1 by a plate discharge driving means 126 (see FIG. 16) including a plate discharge motor (not shown), whereby the endless belt 166 moves in the arrow direction in FIG. The lower plate removal member 161 includes a driving roller 167, a driven roller 168, an endless belt 169, and the like. The driving roller 167 is driven to rotate in the clockwise direction in FIG. 1 by transmitting the driving force of the plate discharging motor that rotates the driving roller 164 by driving force transmitting means (not shown) such as a gear or a belt. The endless belt 169 moves in the direction of the arrow in FIG. Further, the lower plate discharging member 161 is movably provided by a moving unit (not shown) included in the plate discharging driving unit 126, and an endless belt 169 positioned on the outer peripheral surface of the driven roller 168 and the position shown in the figure is the plate cylinder 1. And a position that abuts on the outer peripheral surface.

  The plate removal box 162 stores a used master therein and is detachably attached to the main body frame 130. The compression plate 163 is supported by the main body frame 130 so as to be movable up and down so that the used master carried by the upper plate discharging member 160 and the lower plate discharging member 161 is pushed into the plate discharging box 162. It is moved up and down by lifting means (not shown) including the lifting motor included.

  In FIG. 16, the discharge target drive means 126 is collectively referred to as the control target drive means of the discharge plate section 17 including the discharge motor, the moving means, and the lifting motor of the discharge section 17.

  As shown in FIGS. 1, 11, and 12, the paper feed unit 30 comes into contact with the paper feed tray 35 that can stack and lift up the paper 36 so that the paper 36 can be raised and lowered, and the paper 36 on the paper feed tray 35. The sheet feeding roller 33 and the separating member 34 as sheet feeding means for separating and transporting the sheet 36 one by one toward the nip portion of the registration roller pair 31a, 31b (hereinafter referred to as “registration roller pair 31”). A pair of registration rollers as registration means for feeding the paper 36 at a later-described timing between the outer peripheral surface of the plate cylinder 1 and the press roller 21. 31 and so on.

  The paper feed tray 35 is provided with a drive device (not shown) including a paper feed tray lifting / lowering motor (not shown) as a lifting / lowering means (not shown) for moving the paper feeding tray 35 up and down. The upper level always comes into contact with the paper feed roller 33 with a predetermined pressing force (pressing force capable of transporting the paper 36), that is, in contact with the increase / decrease of the paper 36 with a pressing force within a range in which the paper 36 can be transported. It is raised and lowered while maintaining the state. The paper feed tray 35 has a structure in which many paper types and paper sizes can be used, and the paper stacking capacity is, for example, the paper size A3 (horizontal placement: the user stands in front of the paper in FIG. And a structure suitable for a stencil printing apparatus capable of stacking 500 sheets or more of A4 paper 36.

  As shown in FIG. 13, a pair of side fences 113 a and 113 b for positioning and aligning both side edges of the paper 36 according to the paper size are disposed in the paper feed tray 35 movably in the paper width direction Y. . FIG. 13 shows the paper size detecting means 112. This paper size detecting means 112 determines the paper size of the paper 36 in conjunction with the movement of the side fence pair 113a, 113b in the paper width direction Y.

  The paper size detecting means 112 includes a pair of movable side fences 113a and 113b, a pinion 116 rotatably attached to a stationary member disposed at the lower part of the paper feed tray 35, and a lower part of the side fence 113a. A rack portion 115 formed on the end edge portion and meshed with the pinion 116, a rack portion 114 formed on the lower edge portion of the side fence 113 b and opposed to the rack portion 115 and meshed with the pinion 116, and a rack portion 114 of the side fence 113 b A blocking portion 114a having a plurality of notches protruding downward and bent at an opposed lower end edge and notched at an appropriate interval, and fixed to the stationary member of the paper feed tray 35 at an appropriate interval. A plurality (two in this case) of lateral size detection sensors 118 that selectively engage with the shielding portions 114a, respectively. , 118b and a plurality (three in this case) of vertical size detection sensors 119a, 119b, and 119c fixed at an appropriate interval in the paper conveyance direction X of the stationary member of the paper feed tray 35. ing.

  Each of the horizontal size detection sensors 118a and 118b is a transmissive optical sensor, and detects the length / size of the paper 36 in the paper width direction Y by selectively engaging with the blocking portion 114a. The vertical size detection sensors 119a, 119b, and 119c are reflection type optical sensors. The vertical size detection sensors 119a, 119b, and 119c detect the length and size of the paper 36 in the paper transport direction X. The horizontal size detection sensors 118a and 118b and the vertical size detection sensors 119a, 119b, and 119c are collectively referred to as a paper size detection sensor 117. The paper size detection sensor 117 is electrically connected to the control device 100 to be described later, and the CPU 101 of the control device 100 determines the paper 36 by combining the size signal data detected by the paper size detection sensor 117. This determines the paper size. The paper size detection sensor 117 has a function as a paper size detection unit that detects the paper size of the paper 36, and the vertical size detection sensor 119 a also has a function as a paper presence / absence detection unit that detects the presence / absence of the paper 36.

  For the sake of simplicity, two horizontal size detection sensors for detecting the length and size of the paper 36 in the paper width direction Y and two vertical size detection sensors for detecting the size of the paper 36 in the paper transport direction X are Although three are provided, more sizes may be arranged so that more sizes can be detected. As details of such a paper size detection method, for example, a technique disclosed in Japanese Patent Laid-Open No. 9-30714 can be cited. The paper size detection method is not limited to the method described above, and other methods, for example, the slider slides in conjunction with a paper feed side plate (side fence) and is arranged according to the paper size. It may be one that detects by contacting / connecting with each terminal of the paper size detection plate.

  As shown in FIGS. 1 and 12, the paper feed roller 33 is formed integrally with a metal paper feed roller shaft 33a, and one end of the paper feed roller shaft 33a is rotatable on the casing side plate. It is supported. The surface of the paper feed roller 33 is formed of at least a high friction resistance member such as rubber. A toothed paper feed roller pulley 39 is attached to one end of the paper feed roller shaft 33a. Between the paper feed roller shaft 33a and the paper feed roller pulley 39, a one-way clutch for rotating the paper feed roller 33 so as to transport the paper 36 only in the paper transport direction X, that is, rotating it clockwise only (see FIG. (Not shown) is provided. The separation member 34 has a member called a separation pad that is made of rubber or resin having a high friction coefficient with respect to the paper 36 and that can contact the paper feed roller 33. This separation pad is urged in a direction to be pressed against the paper feed roller 33 by a compression spring (not shown) as urging means.

  As shown in FIG. 12, below the paper feed roller pulley 39, a paper feed motor 37 as a paper feed driving unit that rotationally drives the paper feed roller 33 is fixed to the casing side plate. The paper feed motor 37 is composed of, for example, a stepping motor as a motor driven by pulse input, and a toothed paper feed motor pulley 38 is fixed on the output shaft thereof. A toothed paper feed motor belt 40 is stretched between the paper feed roller pulley 39 and the paper feed motor pulley 38. As a result, the paper feed roller 33 and the paper feed motor 37 are in a rotational driving force transmission relationship between the paper feed motor belt 40 and the one-way clutch.

  As shown in FIGS. 1 and 12, the registration roller upper portion 31a is integrally formed with a metal registration roller shaft, and the registration roller lower portion 31b is integrally formed with a metal registration roller shaft 31c. Both end portions of the housing are rotatably supported by the casing side plate. A toothed registration roller pulley 43 is attached to one end of the lower registration roller shaft 31c. The lower registration roller 31b is supported by the casing side plate through a registration roller shaft 31c so as not to move and to rotate freely. The upper registration roller 31a is provided so as to be able to contact and separate through a registration roller contacting / separating means (not shown) so as to come into contact with the lower registration roller 31b at a predetermined timing.

  As shown in FIGS. 1 and 12, a registration motor 41 as registration driving means for rotating the registration roller pair 31 is fixed to the casing side plate below the registration roller lower 31b. The registration motor 41 includes, for example, a stepping motor as a motor driven by pulse input, and a toothed registration motor pulley 42 is fixedly provided on an output shaft thereof. Between the registration roller pulley 43 and the registration motor pulley 42, a toothed registration motor belt 44 is stretched. Accordingly, the lower registration roller 31 b and the registration motor 41 are in a rotational driving force transmission relationship via the registration motor belt 44.

  In FIG. 1, a sheet for detecting the leading edge and the trailing edge of the sheet 36 fed from the registration roller pair 31 is disposed on a sheet conveyance path XA from the plate cylinder 1 and the press roller 21 to the nip portion of the registration roller pair 31. A paper detection sensor 32 is provided as detection means. In the paper detection sensor 32, the paper 36 stays in the paper transport path XA on the upstream side of the arrangement position of the paper detection sensor 32 (position where the leading edge of the paper 36 can be detected) (jamming or the like occurs). It also has a function to detect. The paper detection sensor 32 is a reflective optical sensor.

  In FIG. 16, control target drive means of the paper feed unit 30 including the paper feed tray lifting / lowering motor, the paper feed motor 37, and the registration motor 41 of the paper feed unit 30 are collectively referred to as a paper feed drive unit 125.

  The paper feed driving means for rotationally driving the paper feed roller 33 is not limited to the paper feed motor 37 and the like, and the rotational driving force from the main motor 20 is supplied by a driving force transmitting means (not shown) such as a gear or a cam. It may be configured to be driven to rotate at a predetermined timing synchronized with the plate cylinder 1. Similarly, the registration driving means for rotationally driving the registration roller pair 31 is not limited to the registration motor 41 or the like, and the rotational driving force from the main motor 20 is transmitted by a driving force transmission means (not shown) such as a gear or a cam. The lower registration roller 31b as a driving roller rotates at a predetermined timing synchronized with the plate cylinder 1, and the upper registration roller 31a as a driven roller pressed against the lower registration roller 31b causes the plate cylinder 1 in the printing unit 16 to move. The paper 36 or the surface-printed paper 36a may be fed at a predetermined timing toward the printing nip portion 16a formed by press contact between the outer peripheral surface and the outer peripheral surface of the press roller 21.

  As shown in FIG. 14, the image reading unit 18 includes the above-described document receiving plate 134 on which a plurality of documents 133 are stacked, a contact glass 135 as a reading unit on which the document 133 is placed, and a document that conveys the document 133. A pair of transport rollers 136 and a document transport roller 137, guide plates 138 and 139 for guiding the transported document 133, a plurality of document transport belts 140 that transport the document 133 along the contact glass 135, and the read document 133 A document tray 141, a pressure plate 142 that supports each member excluding the contact glass 135 and is provided so as to be able to contact / separate / open / close with respect to the contact glass 135, and scans and reads an image of the document 133 while illuminating it Reflection mirrors 143 and 144 and a fluorescent lamp 145 for focusing the reflected light of the scanned and read image That a lens 146, and a like image sensor 147 having a CCD (charge coupled device) or the like for processing the reflected light of the focused image.

  In the above configuration, the original 133 is placed on the contact glass 135 (reading unit) by the original receiving tray 134, the original conveying roller pair 136, the original conveying roller 137, the guide plates 138 and 139, the original conveying belt 140 and the original tray 141. An automatic document feeder (hereinafter referred to as “ADF”) 148 is configured as an automatic document feeder that feeds sheets one by one. Further, a scanner device 132 as a document reading unit that reads an image of the document 133 on the contact glass 135 (reading unit) by the contact glass 135, the reflecting mirrors 143 and 144, the fluorescent lamp 145, the lens 146, and the image sensor 147, Each of the reflecting mirrors 143 and 144, the fluorescent lamp 145, and the lens 146 constitutes a document scanning optical system.

  The document transport roller pair 136, the document transport roller 137, and the document transport belt 140 are driven by a document transport motor (not shown). The scanner device 132 is provided with a scanner motor (not shown) that drives the scanner device 132. The image sensor 147 performs photoelectric conversion corresponding to the received reflected light, and inputs an image signal obtained thereby to the A / D converter.

  In the vicinity of the lower part of the contact glass 135, a document length detection sensor 149a that detects the length of the document in the transport direction (left-right direction) in the view of the document 133 to be transported or a document (not shown) placed on the contact glass 135. 149b, and a document lateral size detection sensor (not shown) for detecting the length of the front side and the back side of the paper surface in the drawing of the document 133 (not shown) placed on the conveyed document 133 or contact glass 135. . The document vertical size detection sensors 149a and 149b and the document horizontal size detection sensor detect the sizes of the document 133 to be conveyed or the document (not shown) placed on the contact glass 135. These are hereinafter referred to as the document size detection sensor 149. Collectively.

  The original size detection sensors 149a and 149b of the original size detection sensor 149 and the original horizontal size detection sensor are both reflection-type optical sensors. The presence or absence of 133 is detected. A signal from the document size detection sensor 149 is input to the control device 100 described later. Based on the signal from the document size detection sensor 149, the control device 100 determines and recognizes the document size (when it is the same size, it is also the size of the plate-making image to be made and formed on the master 8). A document detection sensor 131 that detects the document 133 remaining on the document tray 134 is disposed below the document tray 134. The document detection sensor 131 outputs a signal to the control device 100 when the document 133 on the document tray 134 runs out.

  In FIG. 16, the control target drive means of the image reading unit 18 including the scanner motor and the document transport motor of the image reading unit 18 are collectively referred to as a reading drive unit 128.

  Next, a detailed configuration of the operation panel 173 will be described with reference to FIG. The operation panel 173 is for instructing the double-sided stencil printing apparatus 300 to perform a predetermined operation or the like, and is disposed in the vicinity of the image reading unit 18 shown in FIG. The operation panel 173 has a plate making start key 174, a printing start key 175, a trial printing key 176, a continuous key 177, a clear / stop key 178, a numeric key 179, an enter key 180, a program key 181, a mode clear key 182 on the upper surface of the operation panel 173. Speed setting key 183, four-direction key 184, paper size setting key 185, double-sided printing key 187, single-sided printing key 188, display device 189 composed of 7-segment LED (light emitting diode), display device 190 composed of LCD (liquid crystal display device) Etc.

  The plate-making start key 174 is pressed when the double-sided stencil printing apparatus 300 performs a plate-making operation. When the plate-making start key 174 is pressed, a plate-making operation is performed after a plate-discharging operation and a document reading operation are performed. The printing operation is performed and the double-sided stencil printing apparatus 300 enters a print standby state. The print start key 175 is pressed when the duplex stencil printing apparatus 300 performs a printing operation. When the duplex start stencil printing apparatus 300 enters a print standby state and various printing conditions are set, the print start key 175 is pressed. A printing operation is performed. The trial printing key 176 is pressed when causing the double-sided stencil printing apparatus 300 to perform trial printing, and only one sheet is printed by pressing the trial printing key 176 after various conditions are set. The continuous key 177 is pressed before the plate making start key 174 is pressed when performing the plate making operation and the printing operation continuously. After the continuous key 177 is pressed, the plate making start key 174 is pressed after the printing conditions are input. Then, the printing operation is performed following the plate discharging operation, the document reading operation, and the plate making operation.

  The clear / stop key 178 is pressed when the operation of the double-sided stencil printing apparatus 300 is stopped or when the number is cleared. The numeric keypad 179 is used for inputting numerical values. The enter key 180 is pressed when setting a numerical value or the like during various settings, and the program key 181 is pressed when registering or calling a frequently performed operation. The mode clear key 182 clears various modes. Press to return to the initial state. The print speed setting key 183 is pressed when setting the print speed prior to the printing operation, and when it is desired to obtain a darker image or when the ambient temperature is low, the print speed is slow and a lighter image is desired. Or when the ambient temperature is high, the printing speed is set fast. The four-way key 184 has an up key 184a, a down key 184b, a left key 184c, and a right key 184d. When adjusting the image position during image editing or when selecting numerical values or items at various settings, etc. Pressed. The paper size setting key 185 is pressed when an arbitrary paper size is input, and the paper size input with the paper size setting key 185 has priority over the paper size detected by the paper size detection sensor 73.

  The double-sided printing key 187 is pressed before the plate making start key 174 is pressed when the double-sided stencil printing apparatus 300 performs the double-sided printing operation. When the double-sided printing key 187 is pressed, the LED 187a arranged in the vicinity thereof lights up. Is displayed indicating that the duplex printing mode is set. Similarly to the double-sided printing key 187, the single-sided printing key 188 is pressed before pressing the plate making start key 184 when the double-sided stencil printing apparatus 300 performs a single-sided printing operation. The arranged LED 188a is turned on to indicate that the single-sided printing mode is set. In the double-sided stencil printing apparatus 300, the LED 188a is lit in an initial state after turning on a power switch (not shown), and the single-sided printing mode is set.

  The display device 189 mainly displays numbers such as the number of printed sheets. The display device 190 has a hierarchical display structure. By selecting and pressing selection setting keys 190a, 190b, 190c, and 190d provided below the display device 190, various modes such as scaling and position adjustment can be entered. It can be changed and set in each mode. The display device 190 displays the status of the double-sided stencil printing device 300 such as “can perform plate making / printing” as shown in the figure, warnings such as plate making or discharging jam, paper feeding or paper discharge jam, Supply instructions for supplies such as paper, master, and ink are also displayed.

  Next, the main control configuration of the double-sided stencil printing apparatus 300 will be described with reference to FIG. In FIG. 16, the control device 100 has a function and configuration as control means for controlling mainly a document reading operation, plate making / plate feeding operation, paper feeding operation and printing operation of the double-sided stencil printing apparatus 300. The control device 100 includes a CPU 101 (central processing unit), an I / O (input / output) port (not shown), a ROM 102 (read-only storage device), a RAM 103 (read / write storage device), a timer with a battery (not shown), and the like. And a microcomputer having a configuration in which they are connected by a signal bus (not shown).

  As shown in FIG. 1, the control device 100 is provided in a control board arrangement section in the main body frame 130. The CPU 101 of the control device 100 (hereinafter, sometimes simply referred to as “control device 100” for simplicity of explanation) receives various signals from the operation panel 173 and the above-described various sensors provided on the main body frame 130. Based on the detection signal and the operation program called from the ROM 102, the main motor 20 of the printing unit 16, the stepping motor 252 of the printing pressure range changing unit 28, the solenoid 62 of the locking unit 64, the plate making unit 15, the paper feeding unit 30, Each control target drive unit provided in the plate discharge unit 17, the paper discharge unit 19, and the image reading unit 18, the press roller drive motor 55 provided in the refeed unit 45, the suction fan 109 of the refeed conveyance device 104, the belt Each operation of the drive motor 105, the solenoid 47 of the switching guide 46, and the drive motor 94 provided in the moving means 87 is controlled. And controls the duplex stencil printing device 300 overall operation. The control device 100 also grasps the rotational position of the plate cylinder 1 based on various plate cylinder position signals from the plate cylinder position detection sensor 29 generally shown in FIG.

  The ROM 102 stores an operation program for the entire double-sided stencil printing apparatus 300, necessary data, and the like, and the operation program is appropriately called by the CPU 101. The RAM 103 has a function of temporarily storing calculation results of the CPU 101, a function of storing data signals and on / off signals set and input from various keys and various sensors on the operation panel 173 as needed.

  Based on the above-described configuration, the operation including the operation procedure of the double-sided stencil printing apparatus 300 in the present embodiment will be described in detail with reference to FIGS. 1 to 16 excluding FIG. Since this operation is performed under the control of the control device 100, when describing detailed operations such as activation, operation, and stop of actuators (control target drive means) such as various motors and various solenoids, the control device 100 The expression based on the command or command signal is omitted as much as possible.

(Operation example 1)
First, an operation example 1 in which the simplex printing mode is set and the simplex printing is performed will be described. The operation example 1 is almost the same as the operation of performing single-sided printing by a conventional stencil printing apparatus, and the printing pressure range pattern III is used. For this reason, the cam plate 243A for normal printing is selected from the components of the printing pressure range varying means 28 and used. In the first operation example, in order to facilitate understanding of each operation, the A3 size is used as the master size, and the A3 size is used as the document size and the paper size.

  The user loads A3 size paper 36 as a paper size used for printing on the paper feed tray 35, opens the pressure plate 142, and places an A3 size document to be printed on the contact glass 135, and then again. The pressure plate 142 is closed. Thereafter, after making plate making conditions with various keys on the operation panel 173, the simplex printing key 188 is pressed to set the simplex printing mode.

  The user confirms the single-sided printing mode by turning on the LED 188a, and then presses the plate making start key 174. When the plate making start key 174 is pressed, a paper size detection signal is sent from the paper size detection sensor 117 and a document size detection signal is sent from the document size detection sensor 149 to the control device 100. Compare each signal. At this time, if the paper size and the document size are the same, the image reading operation is immediately performed. If the paper size and the document size are different, the control device 100 displays the fact on the display device 190 and pays attention to the user. Prompt. When the paper size and the document size are different, enlargement / reduction scaling may be automatically performed in response to a command from the control device 100 to match the document size and the image size.

  As described above, in the single-sided printing mode setting state, the switching guide 46 is stopped and held at the first displacement position (initial position) shown in FIG. When a plate making start key 174 is pressed to generate a start signal and is input to the control device 100, a series of operations from discharging to discharging are automatically performed. Prior to this, when the paper feed tray lifting / lowering motor is turned on, the paper feed tray 35 is raised, and the uppermost paper 36 comes into contact with the paper feed roller 33 to turn on a paper feed position detection sensor (not shown). When the control device 100 determines that the uppermost paper 36 is ready to be fed by detection, the paper feeding device 30 enters a paper feed standby state.

  First, in the plate removal unit 17, a plate removal operation for peeling the used master from the outer peripheral surface of the plate cylinder 1 is performed. When the plate making start key 174 is pressed, the plate cylinder 1 starts rotating. When the plate cylinder 1 reaches the home position where the clamper 7 is almost directly above, a home position signal is sent from the home position sensor to the control device 100. Sent. Upon receiving the home position signal, the control device 100 measures the number of pulses generated by the encoder (not shown) based on the home position, and the tip of the used master wound around the outer peripheral surface of the plate cylinder 1 is the driven roller 168. When it is determined that the predetermined plate discharging position corresponding to the endless belt 169 located on the outer peripheral surface of the main motor 20 has been reached, the operation of the main motor 20 is stopped.

  When the main motor 20 is stopped and the plate cylinder 1 is stopped at a predetermined plate discharge position, the plate discharge driving means 126 is operated to rotate the drive rollers 164 and 167 and the lower plate discharge member 161 is moved to the plate cylinder 1 side. The endless belt 169 that moves and is positioned on the outer peripheral surface of the driven roller 168 comes into contact with the used master. When the main motor 20 is started following the operation of the plate discharge driving means 126, the used master scooped up from the outer peripheral surface of the plate cylinder 1 by the rotation of the plate cylinder 1 and the movement of the endless belt 169 is the lower plate discharging member. 161 and the upper plate removal member 160 are nipped and conveyed and peeled from the outer peripheral surface of the plate cylinder 1. The peeled used master is discarded in the discharge box 162 and then compressed by the compression plate 163.

  Even after all used masters are peeled off from the outer peripheral surface, the plate cylinder 1 continues to rotate, and stops until the clamper 7 rotates to a predetermined plate feed standby position located almost directly above. When the plate cylinder 1 stops at the plate feeding standby position, an opening / closing device (not shown) is operated to open the clamper 7, and the double-sided stencil printing apparatus 300 enters a plate feeding standby state.

  In parallel with the plate removal operation, the image reading unit 18 performs a document image reading operation. The original image is read by reflecting the reflected light illuminated by the fluorescent lamp 145 by the respective reflecting mirrors 143 and 144, and the reflected light related to the read original image is focused by the lens 146 and then image sensor 147. And is photoelectrically converted. The photoelectrically converted electrical signal is input to the A / D converter (not shown) in the main body frame 130, and then passes through a plate making control device (not shown) (which may be disposed in the control device 100). It is transmitted to a thermal head drive circuit (not shown).

  In parallel with the plate discharging operation and the image reading operation, the plate making unit 15 performs the plate making operation. That is, a digital image signal for controlling the heat generation of the heat generating element of the thermal head 11 is transmitted to the thermal head 11 via the plate making control device and the like (not shown) and the thermal head driving circuit. As a result, the plurality of heating elements of the thermal head 11 are energized in pulses in the main scanning direction to selectively generate heat, and the master transport motor 10 is driven to rotate, whereby the platen roller 9 and the transport roller pair 13 starts rotating, and the thermoplastic resin film portion of the master 8 is selectively heated and punched according to image information while the master 8 is pulled out from the master roll 8a and is transported in the master transport direction X1.

  Then, the leading end of the master-made master 8Y is inserted between the clampers 7 that are guided by the master guide plate 14 and expanded with respect to the stage 6, and the number of steps of the master transport motor 10 reaches a certain set value, When it is determined that the leading end of the master-making master 8Y has reached between the stage 6 and the clamper 7, the clamper 7 is closed by the opening / closing device, and the leading-end of the master-making master 8Y is between the stage 6 and the clamper 7. Adsorbed and pinched by

  After clamping the front end of the master 8Y, the plate cylinder 1 resumes rotation at the same peripheral speed as the master transport speed by the rotation of the main motor 20, so that the master 8Y is ready for the platen roller 9 and the transport roller pair 13. Is fed to be wound around the outer peripheral surface of the plate cylinder 1. When it is determined that the plate making to the master 8 and the carrying of the set amount of the plate-making master 8Y have been completed by the rotation driving of the master carrying motor 10 by a predetermined number of steps, the cutter 12 is operated to cut the plate-making master 8Y. At the same time, the rotation of the platen roller 9 and the conveyance roller pair 13 is stopped by stopping the rotation of the master conveyance motor 10. When the rear end of the cut master 8Y is drawn out of the plate making unit 15 by the rotation of the plate cylinder 1 and completely wound around the outer peripheral surface of the plate cylinder 1, the master 8Y is transferred to the plate cylinder 1. When the winding of is finished, the plate feeding operation is finished.

  When winding of the plate-making master 8Y around the plate cylinder 1 is completed, the plate cylinder 1 starts to rotate at a predetermined peripheral speed in the direction of the arrow shown in FIG. Be started. Until the leading edge of the paper 36 crosses / passes the paper detection sensor 32, in other words, until the leading edge of the paper 36 is detected ON by the paper detection sensor 32, the solenoid 62 of the locking means 64 is controlled by the control device 100. Therefore, the printing pressure range variable means 28 is in an inoperative state, so that the press roller 21 is held at a non-printing position, that is, at an initial position separated from the outer peripheral surface of the plate cylinder 1. Yes.

  When the plate cylinder 1 rotates at a low speed in the direction of the arrow, first, the sheet feeding start light shielding plate 121 shown in FIG. 11 is engaged with the sheet feeding registration sensor 120, whereby the sheet feeding registration sensor 120 is turned on and fed. A paper start signal is generated, and this signal is used as a trigger to start the paper feed motor 37 (start rotation driving). When the paper feed motor 37 is driven to rotate clockwise in FIG. 12, the paper feed roller shaft 33a and the paper feed roller are fed via the paper feed motor pulley 38, the paper feed motor belt 40, the paper feed roller pulley 39 and the one-way clutch. As the sheet 33 rotates clockwise, the uppermost sheet 36 on the sheet feeding tray 35 that is in contact with the sheet feeding roller 33 is separated into one sheet by the cooperative action with the separating member 34 while being conveyed. The sheet is fed toward the nip portion of the registration roller pair 31 on the downstream side in the transport direction X.

  Next, the plate cylinder 1 further rotates in the direction of the arrow in FIG. 1, and the resist start light shielding plate 122 engages with the paper feed resist sensor 120, whereby the paper feed resist sensor 120 is turned on and a resist start signal is generated. Then, this signal is used as a trigger to activate the registration motor 41 (start rotation driving). The timing at which the registration motor 41 is activated, in other words, the timing at which the lower registration roller 31b is rotated is the image area of the single-side plate-making image 8YA in the plate-cylinder rotation direction of the plate-making master 8Y wound on the plate cylinder 1. It is set at a predetermined timing when the tip end reaches a position corresponding to the press roller 21.

  The registration motor 41 is driven to rotate counterclockwise in FIG. 12, and the registration lower shaft 32a and the registration roller lower 31b rotate counterclockwise via the registration motor pulley 42, the registration motor belt 44, and the registration roller pulley 43. Thus, the leading edge of the sheet 36 that is in contact with the nip portion of the registration roller pair 31 and is waiting is fed while being pressed against the registration roller upper 31 a and is sent out between the plate cylinder 1 and the press roller 21. It is.

  Next, the leading edge of the sheet 36 fed by the registration roller pair 31 is normally entered, that is, the leading edge of the sheet 36 is within a predetermined time counted by the timer (or a predetermined amount supplied to the registration motor 41). This signal is input to the control device 100 when the paper detection sensor 32 detects the ON state within the number of pulses. Based on the detection signal of the leading edge of the sheet 36 from the sheet detection sensor 32 and the rotational position information of the plate cylinder 1 from the plate cylinder position detection sensor 29, the control device 100 instructs the solenoid 62 of the locking means 64 to energize. Is transmitted to a solenoid drive circuit (not shown) related to the solenoid 62, and the solenoid 62 is turned on to operate the cam plate 243A of the printing pressure range varying means 28.

  When the solenoid 62 is turned on, the plunger 62a is sucked, whereby the locking member 60 swings counterclockwise about the support shaft 61 against the urging force of the tension spring 63, and the locking member 60 The other end side of the printing pressure arm 22 with which the notch 22b is locked to the locking claw 60a is unlocked and swings clockwise around the arm shaft 22a by the biasing force of the printing pressure spring 242. To do. By swinging the other end of the printing pressure arm 22, the outer peripheral surface of the cam follower 241 is opposed to the peripheral surface of the small-diameter portion of the cam plate 243A rotating in synchronization with the rotation of the plate cylinder 1. At the rotational position of the cam plate 243A (for example, the rotational position shown by borrowing FIG. 3), the printing pressure arm pair 22 is swung clockwise by the urging force of the printing pressure spring 242 about the arm shaft 22a. .

  As a result, as shown in FIG. 10, the press roller 21 has a single-side plate-making image 8YA of the plate-making master 8Y whose outer peripheral surface is wound on the surface region 1A or the back surface region 1B of the plate cylinder 1 shown in FIG. The paper 36 is pressed to the left end margin part slightly to the left and displaced to the printing position where the printing pressure is applied, so that the printing nip portion 16a (see, for example, FIG. 4) is formed. At the same time, the press roller drive motor 55 rotates the press roller 21 at a substantially same peripheral speed as the peripheral speed of the plate cylinder 1, so that the press roller 21 rotates in the direction opposite to the rotation direction of the plate cylinder 1. By continuously pressing the sheet 36 against the plate-making master 8Y on the plate 1, the plate-making master 8Y is brought into close contact with the outer peripheral surface of the plate cylinder 1 and so-called printing is performed to fill the ink. In this printing, stencil printing is performed by the ink oozing from the opening portion of the opening portion 1a of the plate cylinder 1 to the punching portion of the master-making master 8Y and transferred to the surface of the paper 36.

  At this time, the ink roller 2 also rotates in the same direction as the rotation direction of the plate cylinder 1. The ink in the ink reservoir 4 is attached to the surface of the ink roller 2 by the rotation of the ink roller 2, and the amount of the ink is regulated when passing through the gap between the ink roller 2 and the doctor roller 3. To be supplied. On the other hand, in conjunction with the raising / lowering operation of the press roller 21, the refeed conveyance device 104 swings around the drive shaft 107 a via the refeed housing 110. In the single-sided printing mode, the belt driving motor 105 and the suction fan 109 of the refeed conveyance device 104 remain in an inoperative state, the driving motor 94 of the moving unit 87 also remains in an inoperative state, and the moving guide 81 is The initial position P2 is still occupied.

  In this way, plate printing corresponding to the single-side plate-making image 8YA in the plate-making master 8Y on the plate cylinder 1 is performed, and the plate cylinder 1 is further rotated in the rear end margin portion slightly to the right of the rear end of the single-side plate-making image 8YA. The peripheral surface of the large-diameter portion of the cam plate 243A rotating in synchronization with the plate cylinder 1 comes into contact with the outer peripheral surface of the cam follower 241. As a result, the printing pressure arm pair 22 swings and displaces counterclockwise against the urging force of the printing spring 242 around the arm shaft 22a, and the press roller 21 moves downward to occupy the non-printing position. Thus, the printing pressure application state by the press roller 21 is released.

  When the plate cylinder 1 rotates in the direction of the arrow in FIG. 1 and the clamper 7 reaches the vicinity of the press roller 21 in pressure contact with the plate cylinder 1, the plate cylinder 1 is driven to rotate in synchronization with the rotation of the plate cylinder 1. Since the cam plate 243A rotates the peripheral surface of the large diameter portion to a position where it abuts on the outer peripheral surface of the cam follower 241, the press roller 21 is separated from the clamper 7 protruding outward from the outer peripheral surface of the plate cylinder 1. Thus, interference between the press roller 21 and the clamper 7 can be avoided.

  The one-side printed paper 36c that has been subjected to plate printing is further conveyed by the rotation of the plate cylinder 1 in the direction of the arrow in FIG. 1 while being pressed by the press roller 21, and the leading end of the single-side printed paper 36c is the plate cylinder 1 The separation claw 170 approaching the outer peripheral surface of the sheet and the blower 171 blow off the plate-making master 8Y on the plate cylinder 1 reliably, and the one-side printed sheet 36c that has been separated falls downward and is discharged and conveyed. The sheet is conveyed to the sheet discharge belt 158 of the apparatus 152 and is attracted and held by the suction force of the suction fan 159 on the upper surface of the sheet discharge belt 158 rotating in the direction of the arrow (counterclockwise) in FIG. The paper is conveyed to the downstream side and discharged to the paper discharge tray 172 with its both ends aligned by a pair of paper discharge side fences 172a and 172b.

  On the other hand, when the press roller 21 comes into contact with the outer peripheral surface of the plate cylinder 1, the plate cylinder 1 makes approximately three quarters of a turn, and when the large-diameter portion peripheral surface of the cam plate 243 </ b> A comes into contact with the cam follower 241, When the locking claw 60a of the stop member 60 and the notch 22b of the printing pressure arm 22 can be locked, the energization to the solenoid 62 is interrupted (turned off) by a command from the control device 100. Then, the locking member 60 is swung clockwise around the support shaft 61 by the urging force of the tension spring 63, and the notch 22b of the printing pressure arm 22 is locked to the locking claw 60a. As a result, the press roller 21 is returned to and held in the non-printing position away from the outer peripheral surface of the plate cylinder 1, and the plate cylinder 1 is rotated to the home position again and stopped. The stencil printing apparatus 300 enters a print standby state.

  Further, during paper feeding or plate-making, the platen roller 9 and the conveying roller pair 13 resume rotation, and the leading end of the cut master 8 is sent toward the nip portion of the conveying roller pair 13. If it is determined from the number of pulses of the master transport motor 10 that the tip of the cut master 8 has reached the nip portion of the transport roller pair 13 and has been sandwiched, the rotation of the platen roller 9 and the transport roller pair 13 stops, and the next It will be in the plate-making standby state for the plate-making.

  After the duplex stencil printing apparatus 300 enters a print standby state, when a printing condition is input using the printing speed setting key 183 and various keys on the operation panel 173 and the trial printing key 176 is pressed, the trial printing is performed. When the trial printing key 176 is pressed, the plate cylinder 1 is driven to rotate at the set printing speed, and one sheet of paper 36 is fed from the paper feeding unit 30. The fed paper 36 is temporarily stopped by the registration roller pair 31 and then fed at the same timing as that at the time of printing. The press roller 21 is pressed against the plate-making master 8Y on the outer peripheral surface of the plate cylinder 1. The single-sided printed paper 36c on which the printed image is formed is surely peeled off from the plate-making master 8Y on the plate cylinder 1 by the peeling claw 170 and the peeling fan 171, and the peeled single-sided printed paper 36c is discharged. The paper is transported by the paper transport device 152 in the same manner as described above and discharged onto the paper discharge tray 172.

  Along with the set printing speed, control target drive means such as various motors such as printing pressure range variable means 28, paper feed unit 30, paper discharge conveyance device 152, and various solenoids are driven at speeds and timings suitable for the print speed. Be controlled. When the position or density of the image is confirmed by trial printing, and the print start key 175 is pressed after the number of prints is input by the numeric keypad 179, the paper 36 is continuously fed from the paper supply unit 30, and the trial printing is performed. The printing operation is performed under the same conditions. When the set number of prints (predetermined number) has been consumed, the plate cylinder 1 stops at the home position, and the double-sided stencil printing apparatus 300 enters the print standby state again. In the normal printing operation, as compared with the printing operation at the time of printing, as described above, the number of sheets 36 used for printing is not counted as the normal normal printing number, and the setting desired by the user The main difference is that the operations of paper feeding, printing, and paper discharge at a speed corresponding to the printing speed are performed.

  When the leading edge of the paper 36 is not detected by the paper detection sensor 32 within a predetermined time counted by the timer of the control device 100, the control device 100 detects that the registration roller pair 31 or the upstream of the paper transport direction X is higher than this. On the side, it is determined that the paper 36 is in a staying state due to a jam or the like, and the solenoid 62 of the locking means 64 is turned off to keep the press roller 21 held at the non-printing position as shown in FIG. As a result, the press roller 21 occupies the printing position in spite of the absence of the paper 36, so that it comes into contact with the single-side plate-making image 8YA on the plate-making master 8Y on the plate cylinder 1 and the outer periphery of the press roller 21. The surface is prevented from being stained with ink. Such a control operation is the same in a continuous paper feeding operation in the double-sided printing mode, which will be described later, and will not be described below.

  The sheet detection means corresponding to the sheet detection sensor 32 as described above is conveyed so as to detect the leading edge and the trailing edge of the surface printed sheet 36a which is held on the outer peripheral surface of the press roller 21 and conveyed to the printing nip portion 16a. You may arrange | position on a road. The reading operation in the image reading unit 18 may use ADF 148 in addition to the above. The difference from the operation example 1 in this case is as follows. That is, when an A3-size document 133 is set on the document tray 134 of the ADF 148 by the user, the ADF 148 of the image reading unit 18 is operated in parallel with the plate removal operation, so that one document 133 is read by the reading unit. The only difference is that it is delivered onto a certain contact glass 135. After that, as described above, the image of the original 133 is read as optical information by the operation of the scanner device 132.

(Operation example 2)
Next, an operation example 2 in which the duplex printing mode is set and duplex printing is performed will be described. This operation example 2 includes many operations peculiar to the present invention, and all of the printing pressure range pattern I, the printing pressure range pattern II and the printing pressure range pattern III shown in FIG. 10 are used. For this reason, all of the three cam plates 243A, 243B, 243C of the multistage cam 243 constituting the constituent elements of the printing pressure range varying means 28 are used. In operation example 2, in order to facilitate understanding of each operation, a master size of A3 is used, and a document size and a paper size of A4 are used. Hereinafter, the points different from the operation example 1 will be mainly described.

  The user stacks A4 size paper 36 as a paper size used for printing on the paper feed tray 35, opens the pressure plate 142, and places the first A4 size original for surface printing on the contact glass 135. After placing, the pressure plate 142 is closed again. Thereafter, after setting the platemaking conditions by using various keys on the operation panel 173, the duplex printing key 187 is pressed to set the duplex printing mode, and then the duplex printing mode is confirmed by turning on the LED 187a. Next, when the plate making start key 174 is pressed, a start signal is generated as in the single-sided printing mode, and this is input to the control device 100.

  Similarly to the first operation example, a paper size detection signal is sent from the paper size detection sensor 117 and a document size detection signal is sent from the document size detection sensor 149 to the control device 100. The control device 100 that receives these signals receives each signal. Compare signals. In the present embodiment, since the maximum paper size that can be printed by the plate cylinder 1 during single-sided printing is A3 size, the paper size that can be used during double-sided printing is up to A4 portrait.

  As a result of comparing the document size and the paper size, if the two sizes are the same, the image reading operation is immediately performed. If the two sizes are different, the control device 100 displays a warning on the display device 190 as a warning. Call attention to the user. When the paper size and the document size are different from each other, an enlargement or reduction scaling is automatically performed by a command from the control device 100 to match the document size and the image size. It is good also as a structure which displays procedures, such as rotation, and assists a user's operation. If the paper size exceeds A4 portrait orientation, the control device 100 causes the display device 190 to display a message to prohibit double-sided printing operation and prompt single-sided printing.

  When the plate making start key 174 is pressed, a series of operations from discharging to discharging are automatically performed as in the first operation example. Similarly to the first operation example, when the control device 100 determines that the uppermost sheet 36 in the sheet feeding tray 35 is ready to be fed, the sheet feeding unit 30 enters a sheet feeding standby state. After the plate removal operation similar to Operation Example 1 is performed, the plate cylinder 1 from which all used masters have been peeled off from the outer peripheral surface is stopped at the plate feed standby position as in Operation Example 1, and is opened and closed (not shown) The clamper 7 is opened by the device.

  In part in parallel with this plate removal operation, the image reading unit 18 performs the reading operation of the first original image for front surface printing in the same manner as in Operation Example 1, and the image data signal passes through the plate making control device and the like. Transmitted to the thermal head driving circuit. In part in parallel with the image reading operation, the plate making unit 15 performs plate making by the thermal head 11 as in the operation example 1, and the master 8 is pulled out from the master roll 8a by the rotation of the platen roller 9 and the conveying roller pair 13. While being transported in the master transport direction X1, the thermoplastic resin film portion of the master 8 is selectively heated and punched according to image information, and a surface plate-making image 8A for surface printing is formed in the first half of the master 8. (See the divided master-making master 8X shown in FIG. 10).

  Then, the leading end of the divided prepress master 8X is inserted between the clampers 7 which are guided by the master guide plate 14 and expanded with respect to the stage 6, and the number of steps of the master transport motor 10 reaches a certain set value. When it is determined that the leading end of the divided plate-making master 8X has reached between the stage 6 and the clamper 7, the clamper 7 is closed by the opening and closing device, and the leading end of the divided plate-making master 8X is moved to the stage 6 and the clamper 7. Adsorbed and pinched between.

  After clamping the front end of the divided plate-making master 8X, the plate cylinder 1 resumes rotating at the same peripheral speed as the master conveyance speed by starting the main motor 20 (starting rotation), and the divided plate-making master 8X becomes a platen roller. 9 and the conveying roller pair 13 are fed so as to be wound around the outer peripheral surface of the plate cylinder 1. If the controller 100 determines that the surface plate-making image 8A of the divided plate-making master 8X shown in FIG. 10 has been completed by the number of steps of the master conveyance motor 10, the platen roller 9, the conveyance roller pair 13, and the plate The rotation of the cylinder 1 is stopped, and the plate making standby state for making the back plate making image 8B for back printing in the next divided plate making master 8X is entered.

  Next, the user opens the pressure plate 142 again, places a second A4 size original for back side printing on the contact glass 135, and then closes the pressure plate 142 again. Thereafter, when the plate making start key 174 is pressed again, a start signal is generated and input to the control device 100. At this time, as in the case of the first document, the control device 100 compares the document size with the paper size and performs the same processing operation as described above. In the image reading section 18, the reading operation of the second original image for back side printing is performed in the same manner as the case of the first original, and the image data signal passes through the plate making control device (not shown) or the like. It is transmitted to the thermal head drive circuit. In the plate making unit 15, plate making is performed by the thermal head 11 as in the case of the first document, and the platen roller 9 and the carry roller pair 13 are rotated by the master carrying motor 10 being rotated again. The thermoplastic resin film portion of the master 8 is selectively heated and punched in accordance with image information while the master 8 is being pulled out from the master roll 8a and being transported in the master transport direction X1, and the back surface is formed on the back surface of the master 8 A back side plate-making image 8B for printing is formed (see FIG. 10).

  At this time, the plate cylinder 1 resumes rotating at the same peripheral speed as the master conveyance speed, so that the latter half of the divided plate-making master 8X is drawn out from the plate making unit 15 and wound around the outer peripheral surface of the plate cylinder 1. To go. Then, when the controller 100 determines that the last plate making image 8B of the divided plate making master 8X is completed by the number of steps of the master transport motor 10, the cutter 12 is operated and the divided plate making master is completed. The rear end portion of 8X is cut, the rotation of the platen roller 9 and the conveying roller pair 13 is stopped, and the rear end of the divided plate-making master 8X for one plate cut by the rotation of the plate cylinder 1 is the plate making section 15. The drawing / feeding operation of the divided master-making master 8X to the plate cylinder 1 is completed.

  The document image reading operation and the image data input operation are not limited to the above-described example. For example, the document 133 is automatically transported onto the contact glass 135 using the ADF 148, or an image from an external device (not shown). It is good also as a structure which takes in data. Further, in the duplex printing mode, one original may be reversed and conveyed, and image data for two sheets may be acquired from the front and back surfaces. Further, in the duplex printing mode, one document for front and back printing may be reversed and conveyed, and image data for two sheets may be acquired from the front and back surfaces.

  In this embodiment, when the plate making of the front plate making image 8A in the divided plate making master 8X is completed, the plate making standby state for making the back plate making image 8B for back printing in the next divided plate making master 8X is set. Accordingly, the rotation of the platen roller 9 and the conveying roller pair 13 and the plate cylinder 1 in the plate making unit 15 is temporarily stopped, but it is desirable to do as follows. That is, in addition to the automatic conveyance operation of the original 133 by the ADF 148, an image memory (not shown) including, for example, a bitmap memory or the like that stores a second original in advance and stores and stores image data related to the read original image. If the first and second image data are stored and stored in the image memory and the plate making is performed continuously while sequentially calling the image data, the plate making time can be shortened. And from the viewpoint of shortening the first print time (FPT).

  The printing operation is performed following the plate feeding operation. When the plate cylinder 1 stops at the home position, the control device 100 activates the printing pressure range variable means 28. Hereinafter, when performing printing corresponding to the surface plate-making image 8A in the divided plate-making master 8X on the plate cylinder 1 or performing surface printing in a regular double-sided printing operation described later, the mark shown in FIG. The printing pressure range variable means 28 is controlled so that the printing pressure ON timing by the press roller 21 in the pressure range pattern I is selected. That is, the stepping motor 252 shown only in FIG. 16 is rotationally driven and undergoes a well-known detailed operation through the rotation of the step cam (49), the cam plate 243B is selected, and the contour peripheral surface of the cam plate 243B is the cam follower 241. Abut.

  When the winding of the divided plate-making master 8X to the plate cylinder 1 is completed, the plate cylinder 1 starts to rotate in the direction of the arrow shown in FIG. 3 at a predetermined peripheral speed (usually a low speed for printing). Then, a paper feeding / printing process for printing is started. As in the first operation example, until the leading edge of the paper 36 is detected to be turned on by the paper detection sensor 32, the solenoid 62 of the locking means 64 is controlled to be turned off, so that the printing pressure range variable means 28 is not turned on. The press roller 21 is held in the non-printing position.

  When the plate cylinder 1 rotates in the direction of the arrow, first, the sheet feeding start light-shielding plate 121 shown in FIG. to start. When the paper feed motor 37 is driven to rotate clockwise in FIG. 12, the uppermost first sheet on the paper feed tray 35 in contact with the paper feed roller 33 is operated through the same operation as in the first operation example. While being conveyed, the sheet 36 is separated into one sheet by the cooperative action with the separating member 34 and is sent out toward the nip portion of the registration roller pair 31.

  After the leading edge of the sheet 36 thus fed comes into contact with the nip portion of the registration roller pair 31, the sheet 36 is held in a state where a predetermined curved deflection is formed at the leading end portion of the sheet 36. Next, the plate cylinder 1 further rotates in the direction of the arrow in FIG. 1, and the registration start light shielding plate 122 engages with the paper feed registration sensor 120, whereby the registration motor 41 is started in the same manner as in the first operation example. The registration motor 41 is driven to rotate counterclockwise in FIG. 12, and the leading edge of the paper 36 that has been in contact with the nip portion of the registration roller pair 31 and waiting is the same as in the first operation example. By the rotation of the registration roller pair 31 having the same predetermined timing, it is sent out between the plate cylinder 1 and the press roller 21. At this time, as in the operation example 1, the approach of the leading edge of the paper 36 fed by the registration roller pair 31 is normally detected by the paper detection sensor 32.

  Next, based on the detection signal of the leading edge of the paper 36 from the paper detection sensor 32 and the rotational position information of the plate cylinder 1 from the plate cylinder position detection sensor 29, the control device 100 turns on the solenoid 62 as in the first operation example. Thus, the cam plate 243B of the printing pressure range varying means 28 is operated. When the solenoid 62 is turned on, the detailed operation of the locking means 64 similar to that of the operation example 1 is performed, the contour peripheral surface of the cam plate 243B abuts the outer peripheral surface of the cam follower 241, and the outer peripheral surface of the cam follower 241 is the cam. At the rotational position of the cam plate 243B facing the small-diameter peripheral surface of the plate 243B and in a non-contact state, the printing pressure arm pair 22 swings clockwise around the arm shaft 22a by the biasing force of the printing pressure spring 242. Will rise.

  Thereby, as shown in FIG. 10, the press roller 21 has a slightly smaller outer surface than the surface plate-making image 8A of the divided plate-making master 8X wound on the surface region 1A of the plate cylinder 1 shown in FIG. The paper 36 is pressed against the left end margin and is displaced to the printing position where the printing pressure is applied, so that the printing nip portion 16a is formed (printing by the press roller 21 in the printing pressure range pattern I shown in FIG. 10). Refer to the pressure on timing). At the same time, the press roller drive motor 55 rotates the press roller 21 at a substantially same peripheral speed as the peripheral speed of the plate cylinder 1, so that the press roller 21 rotates in the direction opposite to the rotation direction of the plate cylinder 1. By continuously pressing the sheet 36 against the surface plate-making image 8A portion of the divided plate-making master 8X, the surface plate-making image 8A of the divided plate-making master 8X is brought into close contact with the outer peripheral surface of the plate cylinder 1 and filled with ink. So-called printing is performed. In this plate printing, ink oozes out from the opening portion of the opening portion 1a of the plate cylinder 1 to the perforated portion of the surface plate-making image 8A in the divided plate-making master 8X and is transferred to the surface of the sheet 36, thereby making the stencil plate. Printing is performed.

  At this time, the ink roller 2 also rotates in the same direction as the rotation direction of the plate cylinder 1 as in the first operation example. The ink in the ink reservoir 4 is attached to the surface of the ink roller 2 by the rotation of the ink roller 2, and the amount of the ink is regulated when passing through the gap between the ink roller 2 and the doctor roller 3. To be supplied. In this way, plate printing corresponding to the surface plate-making image 8A in the divided plate-making master 8X on the plate cylinder 1 is performed, and the plate cylinder 1 is further rotated so that the vicinity of the rear end of the surface plate-making image 8A becomes the printing nip portion 16a. When the corresponding rotational position is reached, the circumferential surface of the large-diameter portion of the cam plate 243B and the cam follower 241 come into contact with each other, so that the printing pressure arm 22 rotates counterclockwise about the arm shaft 22a and the press roller 21 does not move. Holds the print position. At this time, since the solenoid 62 of the locking means 64 has already been turned off by a command from the control device 100, the press roller 21 is returned to and held in the initial position state in which the non-printing position is occupied.

  In parallel with the printing operation, the solenoid 47 is turned on when the clamper 7 of the plate cylinder 1 passes over the press roller 21 occupying the non-printing position, whereby the switching guide 46 is shown in FIG. Thus, it is swung counterclockwise about the shaft 47a and occupies the second displacement position and stops. At the same time, when the drive motor 94 of the moving means 87 is activated (for example, forward rotation driving is started), the movement guide 81 is also printed by printing from the initial position (standby position) P2 as shown in FIG. In order to sandwich the leading end position of the substantially central portion of the printed paper 36a in the paper width direction Y, the four protrusions 81c are guided and moved along the guide groove 88 and occupy the moving position P1 in the upper right direction in the drawing. Move to. When the movement guide 81 occupies the movement position P1 by the number of steps of the drive motor 94 reaching a certain set value, the lower release lever 83 is placed on the contour peripheral surface of the release cam 98 as shown by the solid line in FIG. By sliding on and sliding, the clamp claw 81b swings clockwise and stops in a state where it is released from the contact state with the upper surface of the clamping table 81f.

  When the movement guide 81 occupies the movement position P1 and stops, as shown in FIG. 3, the leading edge of the front surface printed paper 36a occupies the second displacement position and stops at the switching guide 46 and the peeling fan 171. By the operation of (see FIG. 1), it is surely peeled off from the divided master-making master 8X (see FIG. 10) on the plate cylinder 1. The front end portion of the peeled surface-printed paper 36a is formed in a gap portion between the upper surface of the clamping base 81f and the free end of the clamp claw 81b by an inclined surface 81ha of each guide 81h provided on the moving guide 81. After being guided and inserted, the leading end of the end fence 81d comes into contact with the paper contact surface 81e of the end fence 81d. When the front end of the front surface printed paper 36a is inserted into the gap between the upper surface of the clamping table 81f and the free end of the clamp claw 81b, the drive motor 94 moves the transport speed of the front surface printed paper 36a (the plate cylinder 1 and the press). The movement guide 81 is started to move diagonally downward to the left in the figure toward the initial position P2 by being activated (for example, reverse rotation driving is started) so as to be substantially the same speed as the circumferential speed by the rotation with the roller 21). To do.

  At this time, in FIG. 9, when the lower release lever 83 is disengaged from the contour peripheral surface of the release cam 98, the clamping pawl 81b swings counterclockwise by the urging force of the torsion coil spring, and the free end of the clamping pawl 81b. And the upper end of the clamping table 81f, the front end of the front-side printed sheet 36a is clamped and clamped at the substantially central portion in the sheet width direction Y. As described above, the moving guide 81 has the front end of the front surface printed paper 36a fixed to the front end of the paper width direction Y, and the front end of the front surface printed paper 36a abuts against the paper contact surface 81e. In this state, the sheet moves obliquely downward to the left in the drawing toward the initial position P2 at a movement speed substantially the same as the conveyance speed of the front-side printed paper 36a.

  As described above, after the plate printing corresponding to the surface plate-making image 8A in the divided plate-making master 8X on the plate cylinder 1 is completed, the press roller 21 is returned to and held in the initial position that occupied the non-printing position. In a paper feed standby state for the next paper feed.

On the other hand, referring to FIG. 4, the surface-printed paper 36a is initially in a state of being clamped and fixed between the free end of the clamp claw 81b of the moving guide 81 and the upper surface of the clamping table 81f by the operation of the moving means 87. When the movement guide 81 occupies the initial position P2 and is stopped toward the position P2, the release lever upper 82 comes into contact with the release pin 99 as shown by a two-dot chain line in FIG. When the clamp claw 81b is swung clockwise, the front end portion including the front end of the surface-printed paper 36a is released from the sandwiched / fixed state.
At this time, after the rear portion of the surface-printed paper 36a is sucked and held by the operation of the paper refeeding / conveying device 104, the front-end portion of the surface-printed paper 36a is formed between the free end of the clamp claw 81b and the upper surface of the clamping table 81f. It is desirable that the position of the sheet 36a is opened in order to reduce the fluctuation of the sheet 36a and improve the positional accuracy of the sheet 36a.

  The solenoid 47 is turned off when the rear end of the front surface printed paper 36a passes the switching guide 46, so that the switching guide 46 is centered on the shaft 47a as shown by the solid line in FIG. 1 by the urging force of the tension spring. It is controlled so as to swing clockwise and return to the first displacement position (initial position) and stop.

  The front-side printed paper 36a having its front end opened is first suctioned by the suction fan 109 of the refeed conveyance device 104 being first driven so that the non-printed image surface on the back side is sucked onto the upper surface of the conveyance belt 108. The front end of the surface-printed paper 36a is held and fixed, and is then rotated and conveyed by the conveying belt 108 via the clockwise rotation of the conveying roller rear 107 by driving the belt driving motor 105 and driving it for a predetermined time. Is conveyed between the press roller 21 and the refeed roller 51. As a result, the front end of the surface-printed paper 36 a is conveyed to a position close to the nip portion to be formed between the press roller 21 and the refeed roller 51, that is, a predetermined position detected by the refeed sensor 52. Thereafter, the belt drive motor 105 is temporarily stopped to stop the rotation of the conveyor belt 108.

Next, based on the rotational position information of the plate cylinder 1 from the plate cylinder position detection sensor 29, the surface of the plate cylinder 1 corresponds to a predetermined position, that is, the reverse side plate-making image 8B in the divided plate-making master 8X on the plate cylinder 1. When the control device 100 determines that the rotational position of the plate cylinder 1 has been reached at which printing on the back surface of the finished paper 36a is possible, the belt drive motor 105 is moved to a predetermined position in accordance with the rotation of the plate cylinder 1 to the predetermined position. By being started again at the timing, the conveying roller 107 starts to rotate clockwise again, so that the conveying belt 108 sucks and holds the back surface of the front-side printed paper 36a, and the circumferential speed of the plate cylinder 1 is almost the same. It begins to rotate clockwise at the same linear velocity.
At the same time, when performing the printing corresponding to the back side plate-making image 8B in the divided plate-making master 8X on the plate cylinder 1 or the back side printing in the regular double-sided printing operation to be described later, FIG. The printing pressure range variable means 28 is controlled so that the printing pressure ON timing by the press roller 21 in the printing pressure range pattern II shown in FIG. That is, the stepping motor 252 shown only in FIG. 16 is rotationally driven, and through a known detailed operation through the rotation of the step cam (49), the cam plate 243C is selected, and the contour peripheral surface of the cam plate 243C is the cam follower 241. Abut.

  Simultaneously with the above-described operation, the press roller drive motor 55 shown in FIG. 2 is driven to rotate, so that the press roller 21 is rotated counterclockwise. The front end of the surface-printed paper 36a, which is close to the nip portion of the paper and temporarily held / waiting on the upper surface of the re-feed sensor 52, is rotated counterclockwise by the press roller 21 that rotates counterclockwise. Guided so as to be conveyed along the outer peripheral surface of the press roller 21 by the roller guide plate 50 at a substantially same peripheral speed as the peripheral speed of the plate cylinder 1 while being sandwiched between the re-feeding roller 51 and the rotating sheet. Then, the plate cylinder 1 and the press roller 21 are conveyed while being turned upside down toward the printing nip portion 16a formed by pressure contact.

  In parallel with this conveyance, when a predetermined rotational position of the plate cylinder 1, that is, a portion in the vicinity of the front end of the back plate-making image 8B on the divided plate-making master 8X on the plate cylinder 1 reaches a rotational position corresponding to the printing nip portion 16a. In this case, when the small diameter portion of the cam plate 243C rotating in synchronization with the rotation of the plate cylinder 1 is in a non-contact state facing the cam follower 241, the press roller 21 has an outer peripheral surface as shown in FIG. The back surface of the surface-printed paper 36a (upper surface in FIG. 4) is formed at the front end portion slightly to the left of the back plate-making image 8B of the divided plate-making master 8X wound on the back surface region 1B of the plate cylinder 1 shown in FIG. Is pressed and displaced to a printing position where printing pressure is applied, and the printing nip portion 16a is formed by the urging force of the printing pressure spring 242, and duplex printing for printing is performed (FIG. 10). Indication Referring printing pressure ON timing by the press roller 21 in the printing pressure range pattern II).

  In this way, the double-side printed paper for printing on which the double-sided printing is performed in which the back side printed image is formed on the back side of the front side printed paper 36a corresponding to the back side plate-making image 8B in the divided plate-making master 8X on the plate cylinder 1. Similarly to the paper discharge operation for the single-side printed paper 36c, 36b is a divided plate-making master 8X on the plate cylinder 1 by air blown from the peeling claw 170 and the peeling fan 171 whose leading end approaches the outer peripheral surface of the plate cylinder 1. The double-sided printed paper 36b that has been reliably peeled off from the paper falls downward and is sent to the paper discharge conveying device 152, and is rotated counterclockwise as shown in FIG. The sheet is conveyed to the downstream side in the sheet conveyance direction X while being attracted and held by the suction force of the suction fan 159 and discharged to the sheet discharge tray 172.

  On the other hand, when the press cylinder 21 makes approximately three-quarters of a turn from the time when the press roller 21 contacts the outer peripheral surface of the plate cylinder 1 and the cam follower 241 contacts the large diameter peripheral surface of the cam plate 243C, an example of operation is performed. 1, the press roller 21 is returned to and held in the non-printing position away from the outer peripheral surface of the plate cylinder 1, and the plate cylinder 1 rotates to the home position again and stops. After the attaching operation, the double-sided stencil printing apparatus 300 enters a print standby state for the next regular double-sided printing.

  After the double-sided stencil printing apparatus 300 is in a print standby state, the printing conditions are input using the printing speed setting key 183 and various keys on the operation panel 173, and the position or density of the image is confirmed by trial printing as appropriate. When the print start key 175 is pressed after the number of prints is input through 179, the paper 36 is continuously fed from the paper supply unit 30, and the duplex printing operation for the set number of sheets set by the ten key 179 is performed.

That is, the set number of double-sided printing operations are performed by re-feeding the first first surface-printed paper 36a (hereinafter, simply referred to as “first surface-printed paper 36a”), as in the above-described printing process. Since it is the same until it is sucked and held by the conveyance belt 108 of the paper conveyance device 104 and then conveyed to a predetermined position where the leading edge is detected by the re-feed sensor 52, the description is omitted. .
In parallel with the operation until the first surface-printed paper 36a is transported by the transport belt 108 to a predetermined position where the leading edge of the paper 36a is detected by the re-feed sensor 52, the second paper 36 is reached. Is fed from the registration roller pair 31 toward the gap between the plate cylinder 1 and the press roller 21 at a predetermined timing through the detailed operation similar to that described above.

  As shown in FIG. 3, the moving guide 81 sandwiches the leading end position in the substantially central portion in the sheet width direction Y of the second front-side printed sheet 36a from the initial position P2 through the same detailed operation as described above. Therefore, the clamp pawl 81b swings clockwise as the release lever lower 83 rides on the release cam 98 as shown by the solid line in FIG. 9 so as to occupy the movement position P1 as much as possible. Then, it waits and stops in a state where it is released from the contact state with the upper surface of the clamping table 81f. On the other hand, in parallel with the movement operation of the movement guide 81 to the movement position P1, the solenoid 47 is turned on when the clamper 7 of the plate cylinder 1 passes over the press roller 21 occupying the non-printing position. The switching guide 46 is swung counterclockwise as shown in FIG. 3 to occupy the second displacement position and stop.

  When the movement guide 81 occupies the movement position P1 and stops in the open state, the next second front surface printed sheet 36a occupies the second displacement position and stops at the switching guide 46 and the peeling fan 171 ( 1), the front end portion of the surface-printed paper 36a that has been peeled off from the divided master-making master 8X (see FIG. 10) on the plate cylinder 1 is guided to the switching guide 46 and the moving guide 81. It is guided by an inclined surface 81ha of 81h, inserted into a gap portion between the upper surface of the clamping base 81f and the free end of the clamp claw 81b, and then abutted against the paper contact surface 81e of the end fence 81d. The tip is abutted and aligned. When the front end of the front-side printed sheet 36a is inserted into the gap between the upper surface of the clamping table 81f and the free end of the clamp claw 81b, the moving means 87 similar to that described above is used. Through the detailed operation, the movement guide 81 starts to move toward the initial position P2 at substantially the same speed as the conveyance speed of the second surface-printed paper 36a.

  At this time, in FIG. 9, when the lower release lever 83 is disengaged from the contour peripheral surface of the release cam 98, the clamping pawl 81b swings counterclockwise by the urging force of the torsion coil spring, and the free end of the clamping pawl 81b. And the upper surface of the clamping table 81f, the leading end of the center portion of the second surface-printed paper 36a in the paper width direction Y is clamped and clamped. The movement guide 81 is moved toward the initial position P2 at substantially the same moving speed as the conveying speed of the front surface-printed paper 36a in a state where the front end of the center portion in the paper width direction Y of the second front surface-printed paper 36a is fixed. In the figure, it moves diagonally to the left.

  4 and 10, when printing is performed on the second sheet corresponding to the surface plate-making image 8A in the divided plate-making master 8X on the plate cylinder 1, and subsequently, it is reversed and conveyed by the refeeding means 45. When printing corresponding to the back side plate-making image 8B in the divided plate-making master 8X on the plate cylinder 1 on the back side of the first front-side printed paper 36a, the normal single-sided printing mode (see operation example 1) is used. Similarly, the printing pressure range variable means 28 is controlled so that the printing pressure ON timing by the press roller 21 in the printing pressure range pattern III shown in FIG. 10 is selected. Since the detailed operation of the printing pressure range varying means 28 at this time is performed in the same manner as in the operation example 1, the description thereof is omitted.

  Although description will be made before and after, based on the rotational position information of the plate cylinder 1 from the plate cylinder position detection sensor 29, the outer periphery of the press roller 21 and the plate cylinder 1 that is rotationally driven in a pressed state are in a predetermined position, that is, the plate cylinder. The control device 100 determines that the rotational position of the plate cylinder 1 has reached the position where printing on the back surface of the first front-side printed paper 36a is possible corresponding to the back-side plate-making image 8B in the divided plate-making master 8X on 1. Then, when the belt driving motor 105 is started again, the post-conveying roller 107 starts rotating clockwise again, so that the conveying belt 108 sucks and holds the back surface of the first front surface printed paper 36a. In this state, it is rotated clockwise at substantially the same linear velocity as the peripheral velocity of the plate cylinder 1. At this time, as shown in FIG. 4, the press roller drive motor 55 is driven to rotate, and the press roller 21 is rotated counterclockwise, so that the nip between the press roller 21 and the refeed roller 51 is reduced. The front end of the surface-printed paper 36a held in contact with the printing portion 36a has a substantially central end in the paper width direction Y and a press roller 21 that rotates counterclockwise and a paper refeed that rotates in the clockwise direction. While being sandwiched between the rollers 51, the plate is already guided by the roller guide plate 50 so as to be conveyed along the outer peripheral surface of the press roller 21 at the same peripheral speed as that of the plate cylinder 1. The cylinder 1 and the press roller 21 are conveyed while being turned upside down toward the printing nip portion 16a formed by pressure contact.

  The detailed operation of the printing pressure range varying means 28 at this time is performed in the same manner as in the operation example 1 as described above. As shown in FIG. 4, the surface plate-making image in the divided plate-making master 8X on the plate cylinder 1 is obtained. The second sheet of paper is pressed against the 8A by the press roller 21, and continuously the press roller 21 occupies the printing position. The back surface of the first front-side printed paper 36 a that has been reversely conveyed by the re-feeding means 45 with respect to 8B is pressed by the press roller 21.

  On the other hand, as shown in FIG. 4, the front-side printed sheet 36a of the second sheet is sandwiched and fixed at the substantially central end in the sheet width direction Y between the clamping claw 81b of the moving guide 81 and the clamping table 81f. When the moving guide 81 is transported toward the initial position P2 through the above-described detailed operation of the moving means 87 and stops when the moving guide 81 occupies the initial position P2, as shown by the two-dot chain line in FIG. When the upper 82 comes into contact with the release pin 99, the clamp pawl 81b is swung clockwise, so that the leading end portion of the second surface-printed paper 36a is released. When the rear end of the second front surface printed paper 36a passes the switching guide 46, the solenoid 47 is turned off and the switching guide 46 is swung clockwise as indicated by the solid line in FIG. It is moved to return to the first displacement position (initial position) and stops.

  The second surface-printed paper 36 a having its front end opened is first suctioned by the suction fan 109 of the refeed conveyance device 104, so that the non-printed image surface on the back surface is sucked onto the upper surface of the conveyance belt 108. The leading end of the second surface-printed paper 36a is brought into contact with the press roller 21 by the rotational conveyance of the conveying belt 108 by temporarily holding and fixing the suction and then driving the belt driving motor 105 for a predetermined time. It is conveyed toward the re-feed roller 51. As a result, the front end of the surface-printed paper 36 a is conveyed to a position close to the nip portion to be formed between the press roller 21 and the refeed roller 51, that is, a predetermined position detected by the refeed sensor 52. Thereafter, the belt drive motor 105 is temporarily stopped to stop the rotation of the conveyor belt 108.

  In parallel with the transport operation of the second front-side printed paper 36a described above, as shown in FIG. 4, the first front side corresponding to the back side plate-making image 8B in the divided master-making master 8X on the plate cylinder 1 The first double-sided printed paper 36b having the back side printed image formed on the back side of the printed paper 36a has a leading end portion similar to the first example and the paper discharge operation at the time of printing in the double-sided printing mode. The double-sided printed paper 36b that has been peeled off from the divided master-making master 8X on the plate cylinder 1 by the air from the peeling claw 170 and the peeling fan 171 approaching the outer peripheral surface of the plate cylinder 1 falls downward. Then, the sheet is conveyed to the sheet conveying apparatus 152 and is conveyed to the downstream side in the sheet conveying direction X while being attracted and held by the suction force of the suction fan 159 on the upper surface of the sheet discharging belt 158 rotating counterclockwise. It is, is discharged to the discharge tray 172.

  In parallel with the first double-sided printing operation, the second front-side printed paper 36a that has been stopped / waiting on the conveyor belt 108, which is a predetermined position whose leading edge is detected by the re-feed sensor 52, Based on the rotational position information of the plate cylinder 1 from the plate cylinder position detection sensor 29, the plate cylinder 1 corresponds to the predetermined position, that is, the second plate-making image 8B in the divided plate-making master 8X on the plate cylinder 1. When the control apparatus 100 determines that the rotation position of the plate cylinder 1 that enables printing on the back surface of the front-side printed paper 36a has been reached, the post-conveying roller 107 is adjusted in accordance with the rotation of the plate cylinder 1 to a predetermined position. By starting to rotate clockwise again at a predetermined timing, the conveyor belt 108 sucks and holds the back surface of the second front surface printed paper 36a, and rotates clockwise at substantially the same linear speed as the peripheral speed of the plate cylinder 1. To be rotated. At the same time, the press roller 21 is rotated counterclockwise, so that the leading edge of the second surface-printed paper 36a is rotated counterclockwise with the press roller 21 rotating counterclockwise. Guided so as to be conveyed along the outer peripheral surface of the press roller 21 by the roller guide plate 50 at a substantially same peripheral speed as the peripheral speed of the plate cylinder 1 while being sandwiched between the re-feeding roller 51 and the rotating sheet. Then, it is conveyed toward the printing nip portion 16a while being turned upside down.

  Similarly to the first double-sided printing described above, the second front-side printed paper 36a has a back side printed image formed on the back side thereof corresponding to the back side plate-making image 8B in the divided plate-making master 8X on the plate cylinder 1. Thereafter, the leading end portion of the plate cylinder 1 is surely peeled off from the divided plate-making master 8X on the plate cylinder 1 by the air blow from the peeling claw 170 and the peeling fan 171 approaching the outer peripheral surface of the plate cylinder 1. The peeled second double-side printed paper 36b is dropped downward and sent to the paper discharge conveying device 152, and is sucked onto the upper surface of the paper discharge belt 158 rotating counterclockwise by the suction force of the suction fan 159. While being attracted and held by suction, it is transported to the downstream side in the paper transport direction X, and is discharged to the paper discharge tray 172.

  Thereafter, the same printing operation as described above is repeated for the set number N of sheets set with the numeric keypad 179 up to the (N−1) th sheet. When performing double-sided printing on the back side of the N-th (last first) front-side printed paper 36a that is temporarily held by the re-feed conveyance device 104 immediately before the end of the printing operation, the mark shown in FIG. The printing pressure range variable means 28 is controlled so that the printing pressure ON timing by the press roller 21 in the pressure range pattern II is selected. That is, the back surface of the N-th surface printed paper 36a is pressed only by the press roller 21 only on the back plate making image 8B in the divided plate making master 8X on the plate cylinder 1, and the same paper discharge operation as described above is performed. After that, the double-sided printing operation of the set number N is completed, and the double-sided stencil printing apparatus 300 enters a print standby state.

  Compared with the double-sided printing operation at the time of printing, the normal regular double-sided printing operation does not count the number of sheets 36 used for printing as described above as the normal normal printing number, and the user However, the only difference is that operations such as paper feeding, refeeding, front surface printing, back surface printing, and paper discharge are performed at a speed corresponding to a desired set printing speed. As described above, in the normal regular duplex printing operation, the set number of duplex printings is performed every rotation of the plate cylinder 1, and the surface plate-making image of the divided plate-making master 8 </ b> X is obtained almost every half rotation of the plate cylinder 1. The front side printing corresponding to 8A is performed in this order in the order of the remaining half rotation of the plate cylinder 1 in the order of the back side plate making image 8B of the divided plate-making master 8X.

FIG. 7 shows a modification of the above embodiment.
This modified example is different from the above-described embodiment only in that it has a movement guide 81A as a sheet clamping means instead of the movement guide 81.
The movement guide 81A is different from the movement guide 81 only in having an end fence 81Ad instead of the end fence 81d. Compared with the end fence 81d of the above-described embodiment, the end fence 81Ad is a printing unit for bringing the front end of the front-side printed paper 36a fed from the printing nip portion 16a into contact with the front end of the substantially central portion in the paper width direction Y. 16 has a stopper portion 81j as a convex stop portion having a sheet contact surface 81ja slightly protruding upstream in the sheet traveling direction Xa fed from the sheet 16.

The front end of the substantially center portion in the paper width direction Y of the surface-printed paper 36a fed from the printing nip portion 16a comes into contact with the paper contact surface 81ja. The step-like thickness ta of the portion of the paper contact surface 81ja in the stopper portion 81j is about 0.1 to 0.3 mm higher than the thickness tb of the portion of the left and right paper contact surfaces 81e in FIG. A stopper portion 81j is integrally formed with the end fence 81Ad.
The formation direction in the height direction of the stopper portion 81j is a range in which the front end of the substantially center portion in the paper width direction Y of the surface-printed paper 36a abuts, that is, from the upper surface of the clamping table 81f to the uppermost end of the guide 81h in FIG. It is sufficient if it is formed.

  The convex stop portion is not limited to the stopper portion 81j integrally formed with the end fence 81Ad, and may be configured by attaching an elastic body made of thin rubber, resin, or the like to the paper contact surface 81e. The end fence may be formed in a curved shape. The protruding amount of these convex stoppers to the sheet contact surface is larger than the contact surface of the end fence with which the left and right ends in the sheet width direction Y of the surface-printed sheet 36a are in contact with both sides of the double-sided stencil printing apparatus 300. In consideration of the strength level of the waist depending on the type of paper used at the time of printing, it may be configured to have a convex of about 0.1 to 0.3 mm as described above.

  According to this modification, by having the stopper portion 81j provided with the paper contact surface 81ja, there is a more significant advantage than the advantage of the movement guide 81 in the above embodiment. That is, when the front end of the surface-printed paper 36a sent out from the printing nip portion 16a hits the paper contact surface of the end fence, first, the front end of the front-side printed paper 36a is substantially in the center in the paper width direction Y. By carrying the sheet in contact with the surface 81ja, as shown by a two-dot chain line in FIG. 7, the front end portion of the surface-printed paper 36a is formed, and its substantially central portion is slightly curved in a U shape in a side view. By applying a force so as to cause the front-side printed paper 36a to be pushed in both left and right ends in the paper width direction Y, the leading edges of both side edges (both sides) of the front-side printed paper 36a that is weak in appearance are In a state where it is in contact with the paper contact surfaces 81e on both the left and right sides with a slight delay, the front end of the front-side printed paper 36a is clamped by the clamp claw 81b at the center in the paper width direction Y. Since it is ramped, when the movement guide 81A is moved, the front end of the front surface printed paper 36a is uniformly applied to the paper contact surface 81e of the end fence 81Ad due to the floating of the left and right ends in the paper width direction Y of the front surface printed paper 36a. It is possible to more reliably reduce the occurrence of skew due to being transferred to and transported to the paper refeeding / conveying device 104 while tilting without contacting.

  According to the present embodiment and the above-described modification, since it is as described above, the above-described advantages can be obtained, and compared with the double-sided printing apparatus (1) disclosed in, for example, Japanese Patent Application Laid-Open No. 2003-200355. Thus, the movement guides 81 and 81A as the sheet clamping means and the movement means 87 are newly provided, and the surface-printed paper 36a is temporarily held by the refeed conveyance device 104 in the refeed means 45. Then, the surface-printed paper 36a is sent to the press roller 21 as the pressing means at a predetermined timing, reversed by the press roller 21, and re-feeded toward the printing nip portion 16a. The auxiliary tray (8) as the refeed storage means as shown in the same publication can be removed without the need for it, In which it is possible to realize a simple double-sided printing apparatus further reducing components by Les. Moreover, similarly to the double-sided printing apparatus (1) of the same publication, a single-sided printing can be performed without using a useless master, and a printed matter with good image quality without printed image density unevenness or printed image density difference during double-sided printing. It is an object of the present invention to provide a one-step double-sided printing apparatus of a new one-plate cylinder / one pressing means double-sided printing method that can be obtained inexpensively and easily and that can suppress an increase in installation space.

  In the present embodiment, since the surface treatment of the outer peripheral surface portion of the press roller 21 is performed as described above, for example, a cleaning roller (26) as a cleaning means as disclosed in JP-A-2003-200355, etc. However, if such an advantage is not desired, a cleaning roller (26) as the cleaning means may be added as a matter of course. Absent.

  The press roller rotation driving means 54 shown in FIG. 2 is not an essential configuration as long as the above-described advantages are not desired, and is disclosed in, for example, Japanese Patent Application Laid-Open Nos. 2003-200265 and 2003-266906. As shown, the press roller 21 may be in contact with the plate cylinder 1 and driven to rotate.

  Instead of the press roller 21 having a small diameter as in the above-described embodiment, the circumferential length of the peripheral surface of the press roller is merely the circumferential length of the front surface region 1A or the back surface region 1B on the outer peripheral surface of the plate cylinder 1. Are used, and those that satisfy this condition and have an integer ratio between the circumferential length of the plate cylinder 1 and the circumferential length of the plate cylinder 1, that is, those that have an integer ratio between the diameter and the diameter of the plate cylinder 1 are used. May be. With such a configuration, it becomes easy to set the peripheral speed of the press roller to the same speed as the peripheral speed of the plate cylinder. In this case, since the circumferential length of the press roller needs to be longer than the circumferential length of the front surface region 1A or the back surface region 1B on the outer peripheral surface of the plate cylinder, the diameter of the press roller and the plate cylinder The ratio to the diameter is preferably 1: 2 or 1: 3. If this ratio is larger than this, the diameter of the plate cylinder becomes too large, which hinders downsizing of the apparatus. For this reason, it is desirable that the diameter of the press roller is in the range of 1/2 to 1/2 of the diameter of the plate cylinder.

  Not only in the plate printing in the operation example 2 of the above embodiment, but when focusing on the basic functions of the plate printing, that is, in order to ensure ink bleeding, the divided master plate 8X is filled with ink and the plate cylinder 1 is used. Focusing on the basic function of printing, which is in close contact with the outer peripheral surface of the printing plate, the printing pressure range pattern III shown in FIG. 10 is selected, for example, in the same manner as printing during normal single-sided printing operation. You may set and perform the plate printing operation.

  In this case, if the maximum sheet passing size in the single-sided printing mode is A3 size, a normal single-sided printing operation can be performed by feeding A3 size paper 36, and as described above, it passes twice through the printing nip portion 16a. Saves time by eliminating the need for paper. In this case, A3 size paper 36 (so-called scraped paper such as damaged paper that has been printed on both sides) may be placed on the paper feed tray 35, and the paper may be fed and printed. In this case, in a double-sided printing apparatus having a plurality of paper feeding units, it is preferable that A3 size paper 36 exclusively for printing is loaded on any one of them and automatically fed and printed. In addition, the operation panel 173 and the like can be used to appropriately select and set the plate printing operation (process) in the double-sided printing mode and the plate printing operation (process) in the normal single-sided printing operation as desired by the user. In addition, it is of course possible to appropriately switch using the printing pressure range variable means 28.

  In the above-described embodiment, the document size detection sensor 149 and the paper size detection sensor 117 are used to cause the control apparatus 100 to recognize the plate-making image area and the paper size related to the document size. Two combinations of the detection sensor 149 and any one of the document size setting means for manually inputting and setting the document size and the paper size detection sensor 117 and any one of the paper size setting means for manually inputting and setting the paper size But you can. Since these operations can be carried out very easily from the configuration and operation example described above, the description thereof will be omitted.

  In the operation example 2 of the above-described embodiment, the front side plate-making image 8A as the first plate-making image and the back side plate-making image 8B as the second plate-making image are formed side by side along the rotation direction of the plate cylinder 1. The operation of performing duplex printing in this order when the divided master-making master 8X is wound around the plate cylinder 1 has been described. However, the duplex printing may be performed in the reverse order.

  In the above-described embodiment, the case of a stencil printing method using a master is illustrated as an example of a double-sided printing device. However, the present invention is not limited to this, and can be applied mutatis mutandis to a printing device of a principle other than the stencil printing method. For example, using a lithographic plate (regardless of the presence or absence of dampening water) as a printing plate used in an offset printing machine or the like, it is relatively easy to implement a direct printing type.

It is a partial cross section front view of the principal part of the double-sided stencil printing apparatus which shows one Embodiment of this invention. FIG. 2 is an enlarged partial cross-sectional front view showing a configuration and operation around a printing unit, a refeed unit, and a printing pressure range variable unit of the double-sided stencil printing apparatus in FIG. 1. FIG. 2 is an enlarged partial cross-sectional front view illustrating a configuration around a printing unit, a refeed unit, a printing pressure range variable unit, and a surface printing operation of the double-sided stencil printing apparatus in FIG. 1. FIG. 2 is an enlarged partial cross-sectional front view illustrating a double-sided printing operation in parallel with a configuration of a printing unit and a refeeding unit of the double-sided stencil printing apparatus in FIG. It is the top view which looked at the movement guide of the double-sided stencil printing apparatus in FIG. 1 from the V direction of FIG. It is a partial cross section front view which shows the principal part around the guide of the movement guide in FIG. 5, FIG. It is the partial cross section top view which looked at the movement guide in the modification of the said embodiment from the V direction of FIG. FIG. 2 is a partial sectional front view around a moving guide and moving means of the double-sided stencil printing apparatus in FIG. 1. FIG. 2 is a partial cross-sectional front view around a movement guide, a release cam, and a release pin of the double-sided stencil printing apparatus in FIG. 1. FIG. 3 is a diagram for developing and explaining three printing pressure range patterns applied corresponding to a divided master-making master on a plate cylinder used in the double-sided stencil printing apparatus in FIG. 1. FIG. 2 is a perspective view showing an arrangement example of a sheet feeding start light shielding plate and a resist start light shielding plate used in the double-sided stencil printing apparatus in FIG. 1 on an end plate of a plate cylinder. FIG. 2 is a front view of a main part showing a drive mechanism of a paper feed roller and a registration roller of a paper feed unit of the double-sided stencil printing apparatus in FIG. 1. FIG. 2 is a perspective view of a main part of a paper size detection unit disposed in a paper feed tray of a paper feed unit of the double-sided stencil printing apparatus in FIG. 1. It is a front view of the principal part of the image reading part of the double-sided stencil printing apparatus in FIG. It is a top view of the principal part of the operation panel of the double-sided stencil printing apparatus in FIG. It is a block diagram which shows the control structure of the principal part of the double-sided stencil printing apparatus in FIG. It is a front view of the principal part explaining the problem of the conventional double-sided stencil printing apparatus. It is a front view of the principal part explaining the problem of the conventional double-sided stencil printing apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Plate cylinder 2 Ink roller 8 which comprises an ink supply means Master 8A The surface plate-making image 8B as a 1st plate-making image 8C The back surface plate-making image 8C as a 2nd plate-making image 8X Intermediate | middle non-plate making area | region 8X The division plate-making master 8Y The plate-making master 8YA Single-side plate-making image 11 Thermal head 15 as plate-making means 15 Plate-making part 16 Printing part 16a Printing nip part 17 Plate-release part 18 Image reading part 19 Paper discharge part 20 Main motor 21 as plate-cylinder driving means Re-feed as pressing means Press roller 27 constituting means Printing pressure cam 28 constituting printing pressure range varying means Printing pressure range varying means 30 Paper feed section 32 Paper detection sensor 33 as paper detection means Paper feed roller 35 as paper feed means Paper feed stand Paper feed tray 36 Paper 36a Front side printed paper 36b Double side printed paper 36c Single side printed paper 45 Refeed Means 46 Switching guide 47 as switching means Solenoid 48 as switching drive means Refeeding section 50 Roller guide plate 51 as refeeding guide member Refeeding roller 52 as refeeding roller member Surface printed paper detection means Refeeding sensor 64 as a locking means 81, 81A Movement guide 81b as a paper clamping means Clamp claw 81d as a clamping member, 81Ad End fence 81e as a locking member Paper contact surface 81j As a convex locking part Stopper part 81ja Paper contact surface 82 of the stopper part Release lever upper 83 Release lever lower 87 Moving means 88 Guide groove 98 as guide means constituting the moving means Release cam 99 constituting operation time control means Release pin 100 As control means Control device 101 CPU
102 ROM
104 Refeed transport device 173 Operation panel 300 Double-sided stencil printing device P1 as an example of a double-sided printing device P1 Movement position P2 as a first position X Initial position as a second position X Paper transport direction X1 Master transport direction Y Paper width direction

Claims (5)

Relative to the plate cylinder and the plate cylinder around which the divided plate-making master, in which the first plate-making image and the second plate-making image are formed side by side along the rotation direction of the plate cylinder, is wound. A printing unit having a detachable pressing means;
A paper feed unit for feeding paper toward the printing unit;
A paper discharge unit for discharging printed paper printed by the printing unit;
The printing unit temporarily holds the surface-printed paper having the printed image formed on the surface corresponding to the first plate-making image or the second plate-making image, and then presses the surface-printed paper to the pressing unit. Refeeding means for sending out toward the printing section and refeeding the printing section by reversing by the pressing means;
The front end of the surface-printed paper fed from the printing unit is sandwiched near the first position in the vicinity of the printing unit in the width direction of the sheet, and the refeeding unit is lower than the first position. Paper nipping means for opening the front end of the surface-printed paper at a second position near the upstream side;
Moving means for reciprocating the sheet clamping means between a first position and a second position;
When the paper clamping means occupies the first position, the paper clamping means is opened once and then operated so as to clamp the front end of the front surface printed paper. An operation timing control means for operating the paper clamping means to open the front end of the surface-printed paper when the position is occupied;
A double- sided printing apparatus having switching means for guiding the paper that has passed through the printing unit to the paper clamping unit or the paper discharge unit, and capable of printing on both sides of the paper with one rotation of the plate cylinder ,
The paper sandwiching means includes a stopper member that abuts the front end of the front surface printed paper fed from the printing unit,
The impact member is a convex shape slightly projecting from the impact member on the upstream side in the direction of feeding from the printing portion for contacting the front end of the substantially center portion in the paper width direction of the surface-printed paper. A double-sided printing apparatus comprising a stop portion . Relative to the plate cylinder and the plate cylinder around which the divided plate-making master, in which the first plate-making image and the second plate-making image are formed side by side along the rotation direction of the plate cylinder, is wound. A printing unit having a detachable pressing means; a paper feeding unit that feeds paper toward the printing unit; a paper discharge unit that discharges printed paper printed by the printing unit; and After temporarily holding the surface-printed paper having the printed image formed on the front surface, the surface-printed paper is sent out toward the pressing unit, reversed by the pressing unit, and re-feeded toward the printing unit. A double-sided printing apparatus comprising: a paper re-feeding unit that performs switching; and a switching unit that guides the paper that has passed through the printing unit to the paper re-feeding unit or the paper discharge unit.
The front end of the surface-printed paper fed from the printing unit is clamped at a substantially central end in the paper width direction near the first position near the printing unit, and is lower than the first position. Paper nipping means for opening the front end of the surface-printed paper at a second position near the upstream side;
Moving means for reciprocating the sheet clamping means between a first position and a second position;
When the paper clamping means occupies the first position, the paper clamping means is opened once and then operated so as to clamp the front end of the front surface printed paper. when the position occupied, and the the paper clamping means possess an actuation timing control means for actuating so as to open the tip of the surface-printed paper,
The paper sandwiching means includes a stopper member that abuts the front end of the front surface printed paper fed from the printing unit,
The impact member is a convex shape slightly projecting from the impact member on the upstream side in the direction of feeding from the printing portion for contacting the front end of the substantially center portion in the paper width direction of the surface-printed paper. A double-sided printing apparatus comprising a stop portion . The double-sided printing apparatus according to claim 1 or 2,
The double-sided printing apparatus, wherein the paper sandwiching means has a single openable and closable gripping member that sandwiches the front end of the front-side printed paper in a substantially central portion in the paper width direction. The double-sided printing apparatus according to claim 3.
The double-sided printing apparatus, wherein the sandwiching member is inclined in the traveling direction of the front surface printed paper fed from the printing unit. The double-sided printing apparatus according to any one of claims 1 to 4,
The double-sided printing apparatus , wherein the operation timing control means has a cam .

Images