JP2006247962A - Duplex printing method and duplex printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that surface-printed paper is wasted due to the necessity of processing such as the removal of not only paper causing a jammed state but also lower surface-printed paper staying midway through carrying by a paper refeeding part, for example, when the paper is wound up onto a plate cylinder or paper jamming occurs because the paper gets hung up, for example, midway through a paper ejection path, in a paper ejection process including backside printing. <P>SOLUTION: A control unit 100 controls a driving motor 94 of a moving means 87 in the state of holding the surface-printed paper by a movement guide 81, so that the movement guide 81 can be stopped near a second position, on the basis of a signal, associated with the paper jamming, from a paper ejection sensor 65, and a signal, associated with stop near the second position, from a stop-position sensor 86. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

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

In general, a laminate structure in which a thermoplastic resin film generally having a thickness of about 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 simply referred to as “master”) is brought into contact with the heat generating element of the thermal head to perform heat drilling and plate making through the operation in the main scanning direction of the thermal head, A master screen having a plate made by a platen roller or the like is moved in the sub-scanning direction (master transport direction) perpendicular to the main scanning direction while a master screen is used, and a mesh screen made of, for example, a resin or metal mesh is wound in multiple layers. It is wound around a rotatable cylindrical cylinder with a porous cylindrical structure, and the master plate on the plate cylinder is made from the ink supply member provided inside the plate cylinder. Printing as an example of a sheet-like recording medium on a pre-printed master on a plate cylinder by pressing means called a press roller, an impression cylinder, or an intermediate pressing roller (hereinafter referred to as “press roller”) A thermal digital stencil printing device that performs printing by continuously pressing paper (hereinafter simply referred to as “paper”) 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. It has been known.
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 loaded in 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, since the printing is performed twice, or since 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 and set to a so-called set state, The printing time has become very long, and the work of neatly arranging the single-sided printed matter and the setting of the single-sided printed matter again in the paper feeding unit has been very troublesome.
In order to improve the conventional double-sided printing method with manual operation as described above, a double-sided printing device that can automatically perform double-sided printing has been actively developed, and there are several types of double-sided printing devices. Proposed.

For example, Japanese Patent Application Laid-Open No. 2003-266906 has referred to the conventional double-sided printing method as being roughly divided into six. That is, (1) In the two-drum facing one-pass simultaneous duplex printing method, two plate cylinders can be opposed to each other and printing can be performed on both sides of a sheet of paper in one pass. In order to prevent ink transfer from the plate cylinder on one side corresponding to printing, there is a restriction such as mounting a masterless master, and there is a problem that the master is wasted and the operation is troublesome (for example, , See Patent Document 1).
The other five double-sided printing methods can be broadly divided into (2) stock refeeding type two-pass double-sided printing method after single-sided printing (see, for example, Patent Document 2), and (3) two-drum facing type. Transfer cylinder intervening one-pass simultaneous double-sided printing method (for example, see Patent Document 3), (4) 1-drum divided printing simultaneous reversal type double-sided printing method (for example, see Patent Document 4), (5) 1-drum divided printing transfer cylinder There is a one-pass duplex printing method (see, for example, Patent Document 5).
Therefore, although the paper size is limited, (6) The above problems (1) to (5) can be solved as a whole, and single-sided printing can be performed, and at the same time image quality is good at the time of duplex printing without using a useless master. Innovative one-step double-sided printing apparatus capable of obtaining a large printed product and further suppressing an increase in installation space, that is, the double-sided printing method of (4) is a basic method (however, a single pressing means) As a press roller and a single ink 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”). A new and inexpensive double-sided printing apparatus that solves and solves the problem of lack of reliability and high-speed printing compatibility has been proposed and tried (see, for example, Patent Documents 6 to 8).

This is because the first plate-making image and the second plate-making image are arranged side by side along the rotation direction of the plate cylinder, as disclosed in Japanese Patent Application Laid-Open No. 2003-200355 (Patent Document 6) by the applicant of the present application. A printing cylinder having a plate cylinder on which the plate-making master for double-sided printing formed in step 1 is wound and a pressing unit that is relatively movable toward and away from the plate cylinder; After forming a printed image on the surface corresponding to one of the plate-making image and the second plate-making image, the surface-printed paper is moved by a switching member around the position where it passes the nip portion between the plate cylinder and the pressing means. While being guided downward, the paper is once transported and held down to a position where it can be transferred to the pressing means by the refeeding means, and then pressed in such a manner that it is reversed and reversed with the surface-printed paper that is re-feeded thereafter. Using the rotation of the means Conveyed between the plate cylinder and the pressing means, and a printed image is formed on the back surface of the surface printed paper corresponding to the other of the first plate-making image and the second plate-making image in the plate-making master on the plate cylinder By doing so, double-sided printing is performed continuously.
In other words, surface-printed paper (single-sided printed paper) can be re-used by skillfully utilizing the paper reversing / conveying action by the rotation of a single pressing means (especially a press roller having a diameter smaller than the outer diameter of the plate cylinder). This is a system in which double-sided printing is performed while continuously feeding the back surface, which is the unprinted surface of the front surface printed paper, to either one of the two pre-made masters on the plate cylinder.

JP-A-6-71996 JP 7-81202 A JP-A-8-118774 JP-A-9-95033 JP-A-10-129100 JP 2003-200355 A JP 2003-266906 A JP 2004-224479 A

  In the double-sided printing apparatus as disclosed in Patent Documents 6 to 8, in the paper discharge process including when printing on the back side, as the paper conveyance abnormality, for example, the double-sided printed paper printed on the back side has ink adhesion on the plate cylinder. The jammed paper is printed on the lower surface where the jammed paper stays in the middle of the re-feeding section when it is jammed due to a problem such as roll-up that is stuck and not ejected, etc. There is a problem that processing for removing the used paper is necessary, and the front printed paper is wasted.

  Therefore, according to the present invention, it is possible to perform double-sided printing easily and inexpensively using the one-plate cylinder 1-pressing means double-sided printing method, as well as when a jam or the like occurs in the paper discharge process including the backside printing. The main object of the present invention is to provide a double-sided printing method and a double-sided printing apparatus that do not waste the surface-printed paper. In addition, another object of the present invention is to provide a double-sided printing method and a double-sided printing apparatus that can obtain the advantages and effects described below.

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.
In the invention described in claim 1, a plate cylinder around which a plate-making master for double-sided printing, in which two first and second plate-making images are formed side by side along the rotation direction of the plate cylinder, and A printing unit having pressing means that can be moved toward and away from the plate cylinder, and a printing image on the surface of the printing unit corresponding to one of the first plate-making image and the second plate-making image. The formed front surface printed paper is temporarily held and then re-feeded toward the printing unit, and the front end of the front surface printed paper disposed in the re-feeding unit is printed. And a movable sheet holding means for holding the front-side printed sheet at a first position in the vicinity of the printing unit and opening the front end of the printed sheet at the second position. A printed image corresponding to the other of the first plate-making image and the second plate-making image is printed on the back side of the printed paper. In the double-sided printing method using the double-sided printing apparatus to be formed, if a conveyance abnormality occurs when forming a printed image on the back side of the front-side printed paper, printing is performed using the front-side printed paper held by the paper holding unit It is characterized by having comprised so that it may restart.

  According to a second aspect of the present invention, in the double-sided printing method according to the first aspect, when the conveyance abnormality occurs, the paper holding unit is used to hold the surface-printed paper and stop near the second position. It is characterized by being configured.

  According to a third aspect of the present invention, in the double-sided printing method according to the first or second aspect, the pressing means is driven at substantially the same peripheral speed as the plate cylinder, and a printed image is printed only on the back surface of the surface-printed paper. When the pressing means is operated so as to form an image, the entry timing of the front end of the surface-printed paper into the pressing means is delayed by a predetermined amount from the time of continuous duplex printing.

  According to a fourth aspect of the present invention, there is provided a plate cylinder on which a plate-making master for double-sided printing, in which two first and second plate-making images are formed side by side along the rotation direction of the plate cylinder, and A printing unit having pressing means that can be moved toward and away from the plate cylinder, and a printing image on the surface of the printing unit corresponding to one of the first plate-making image and the second plate-making image. The formed front surface printed paper is temporarily held and then re-feeded toward the printing unit, and the front end of the front surface printed paper disposed in the re-feed unit is printed A sheet holding unit that holds the sheet at a first position near the portion and opens a front end of the surface-printed sheet at a second position, and the sheet holding unit reciprocates between the first position and the second position. Moving means for moving the first printed sheet on the back surface of the front printed sheet that has been re-fed from the re-feed unit. In the double-sided printing apparatus that forms a printed image corresponding to the other of the plate image and the second plate-making image, a conveyance abnormality detection that detects that a conveyance abnormality has occurred when the printed image is formed on the back surface of the front-side printed paper. And on the basis of a signal from the conveyance abnormality detecting means, the movement is performed so that the paper holding means holds the surface printed paper and the paper holding means stops at a predetermined position. And first control means for controlling the means.

According to a fifth aspect of the present invention, in the double-sided printing apparatus according to the fourth aspect, the predetermined position of the paper holding unit is preliminarily in the vicinity of a second position where the paper holding unit holds the surface-printed paper. A position detection unit configured to detect that the sheet holding unit occupies the vicinity of the second position, and the first control unit is configured to detect each of the conveyance abnormality detection unit and the position detection unit. Based on the signal, the moving means is controlled so that the paper holding means stops near the second position.
According to a sixth aspect of the present invention, in the double-sided printing apparatus according to the fourth or fifth aspect, the printing pressure is applied only to the first image area corresponding to the first plate-making image in the plate-making master on the plate cylinder. 1 printing pressure range pattern, a second printing pressure range pattern that applies printing pressure only to the second image area corresponding to the second plate-making image in the master-making master on the plate cylinder, and the first image area A printing pressure range variable means capable of selectively switching at least one of at least three printing pressure range patterns of the third printing pressure range pattern for applying printing pressure over the second image area; Press driving means for driving the pressing means at substantially the same peripheral speed as the plate cylinder, and refeeding for temporarily holding the surface-printed paper disposed in the refeed unit and transporting it toward the pressing means Before the paper conveying means and the paper re-feeding section The reprinting contact means for contacting the surface-printed paper conveyed by the refeeding conveyance means with the pressing means, and the printing pressure range variable means for switching to the second printing pressure range pattern. When the pressing means is operated to form a printed image only on the back surface of the printed paper, the front end of the surface printed paper by the refeed conveyance means between the pressing means and the refeed contact means The second feeding control unit controls the refeed conveying unit to delay the entry timing by a predetermined amount from the time when the printing pressure range changing unit is used to switch to the third printing pressure range pattern to perform double-sided continuous printing. Control means.

  According to a seventh aspect of the present invention, in the double-sided printing apparatus according to the fourth or fifth aspect, the printing pressure is applied only to the first image area corresponding to the first plate-making image in the plate-making master on the plate cylinder. 1 printing pressure range pattern, a second printing pressure range pattern that applies printing pressure only to the second image area corresponding to the second plate-making image in the master-making master on the plate cylinder, and the first image area A printing pressure range variable means capable of selectively switching at least one of at least three printing pressure range patterns of the third printing pressure range pattern for applying printing pressure over the second image area; Press driving means for driving the pressing means at substantially the same peripheral speed as the plate cylinder, and refeeding for temporarily holding the surface-printed paper disposed in the refeed unit and transporting it toward the pressing means Before the paper conveying means and the paper re-feeding section A refeed stop means for temporarily stopping the front end of the front surface printed paper conveyed by the refeed conveyance means before being delivered to the pressing means; and the refeeding means disposed in the refeed section. A re-feeding resisting means that is displaceable between a contact position where the surface-printed paper transported by the transporting means is brought into contact with the pressing means and a separation position separated from the contact position; and the printing pressure range When the pressing means is operated to form a print image only on the back side of the front-side printed paper by changing the second printing pressure range pattern using the variable means, the re-feed stop means temporarily stops the operation. The contact timing at which the leading edge of the printed surface printed paper comes into contact with the pressing means is delayed by a predetermined amount than when double-sided continuous printing is performed by switching the printing pressure range variable means to the third printing pressure range pattern. To do And having a second control means for controlling the refeed registration means.

ADVANTAGE OF THE INVENTION According to this invention, the problem which the conventional double-sided printing apparatus as mentioned above has can be solved, and a novel double-sided printing method and double-sided printing apparatus can be provided.
According to the present invention, when the conveyance abnormality such as a jam occurs due to some trouble due to the above configuration, the lower surface printed paper stays in the middle of the conveyance of the refeed unit and the refeed unit as in the past. It is no longer necessary to remove the paper, and it becomes possible to reduce the waste of the printed surface printed paper. In addition, since the front surface printed paper is held by the paper holding means, the front surface printed paper does not move during the conveyance abnormality processing (for example, during jam processing), and is reused after resuming printing. Therefore, there is no occurrence of the same conveyance abnormality (for example, jam) due to the movement of the print image or the print image deviation due to skew or the like (claims 1 and 4).

  According to the present invention, with the above-described configuration, it is possible to easily and accurately control the position of the sheet holding unit when resuming printing using the surface-printed sheet (claims 2 and 5).

  According to the present invention, it is possible to prevent a misalignment of the print image that occurs during printing corresponding to the second plate-making image or during printing corresponding to the second plate-making image during regular duplex printing. (Claims 3, 6 and 7).

  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. Constituent elements such as members and components having the same function and shape throughout the embodiment and the modified examples are given the same reference numerals and will not be described after being described once. 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 embodiment)
First, with reference to FIG. 1 etc., the whole structure of the double-sided stencil printing apparatus 300 as an example of the double-sided printing apparatus which concerns on the 1st Embodiment of this invention is demonstrated. As shown in FIG. 1, a double-sided stencil printing apparatus 300 includes a plate-making unit 15 for making a master 8 placed in the upper left side of FIG. 1 and wound in a roll shape, and a master-making master arranged at a substantially central portion in FIG. On the outer peripheral surface of the plate cylinder 1, an ink supply means for supplying ink to a master made on the plate cylinder 1 to be described later, and an outer peripheral surface of the plate cylinder 1. A printing unit 16 having a press roller 21 or the like as a pressing unit that presses a sheet 36 (an example of a sheet recording medium) to a master that has made a plate, and a plate cylinder 1 that is disposed to face the plate making unit 15 with the plate cylinder 1 interposed therebetween. A plate discharging unit 17 that peels and discharges the used master, and a paper feeding unit 30 that is disposed below the plate discharging unit 17 and feeds the paper 36 on the paper feeding tray 35 serving as a paper feeding base toward the printing unit 16. And the plate making unit 15 facing the sheet feeding unit 30 A paper discharge unit 19 that peels the printed paper 36 disposed below from the plate cylinder 1 and discharges the paper 36 onto a paper discharge tray 172 as a paper discharge table, and as shown in FIG. 11, the plate cylinder 1, the plate making unit 15 and An image of a document 133 which is arranged on the upper part of a main body frame 130 as an apparatus main body provided with a plate discharging unit 17 (both are omitted in FIG. 11) or transferred from a document receiving table 134 or a contact glass as a reading unit. And an image reading unit 18 for reading an image of a document or the like (not shown) placed on 135.

  Further, the double-sided stencil printing apparatus 300 temporarily holds the surface-printed paper on which the printed image is formed as will be described later in the description of the printing unit 16, and then transfers the surface-printed paper to the press roller 21. A refeeding unit 48 that reverses by the press roller 21 and refeeds toward the printing unit 16, and a paper refeeding unit that passes the printing unit 16 (surface-printed paper or double-sided printed paper). 48 or a switching guide 46 as switching means for guiding to the paper discharge unit 19.

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. As described later, one rotation of the plate cylinder 1 is performed. 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, and paper refeed unit 48 described above each have a configuration as an apparatus 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, a portion of the configuration of the movement guide 81 is changed, and the control configuration is changed.
Further, the double-sided stencil printing apparatus 300 is different from the double-sided printing apparatus 1 disclosed in Japanese Patent Application Laid-Open No. 2004-224479 by the applicant of the present application in that the configuration of the refeed unit 48 is changed. 15, a part of the configuration of the printing unit 16, the plate discharging unit 17, the paper feeding unit 30, and the paper discharging unit 19 is changed, and the arrangement of these units with respect to the plate cylinder 1 and the control configuration are mainly changed. Is different. Accordingly, the configurations of the plate making unit 15, the printing unit 16, the plate discharging unit 17, the paper feeding unit 30, and the paper discharging unit 19 are well known and will be briefly described.

  The plate making unit 15 performs plate making on the master 8 based on the image information, and as shown in FIG. 5, the plate making unit 15 is used for surface printing along the rotation direction of the plate cylinder 1 (also the paper transport direction X and the master transport direction X1). A divided master-making master 8X having a first plate-making image 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”); Alternatively, as shown in the figure, a third plate-making image 8YA (hereinafter referred to as “single-side plate-making image”) having an image amount area corresponding to two sides 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. And a function / 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. 5 and the like, the master-made master 8Y is indicated with parentheses to distinguish it from the divided master-made master 8X. In FIG. 5, 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-side plate-making image 8A and the back-side plate-making image 8B. Although the area range is illustrated as being slightly larger, the area range of the single-side plate-making image 8YA is an intermediate unprinted blank area located between the front-side plate-making image 8A, the back-side plate-making image 8B, and these. This is the entire range including the plate making area 8C.
In FIG. 5, 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 out in scale, and the intermediate non-plate making region 8C is particularly 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 the master 8 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 roll core 8b to form a master roll 8a. 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.

  The thermal head 11 extends in parallel to the platen roller shaft of the platen roller 9 and the front 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, melting, punching and making the master 8.

  The platen roller 9 is formed integrally with the platen roller shaft, and both end portions of the platen roller shaft are rotatably supported by the plate-making side plate pair so as to be rotatable clockwise. 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 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 may be 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.
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.
In the plate making unit 15 shown in FIG. 13, the control target drive means of the plate making unit 15 including the thermal head 11 and the master transport motor 10 driven by a thermal head drive circuit (not shown) are collectively referred to as plate making drive unit 124. .

  The plate cylinder 1 has a two-layer structure of 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 “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 and fixed around 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. The 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 the cooperative action of the rotary encoder. Yes. The plate cylinder sensor includes a transmissive optical sensor (hereinafter simply referred to as a “transmissive optical sensor”) having a light emitting unit and a light receiving unit, and controls the rotational speed (printing speed) and rotational position of the plate cylinder 1. 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 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 It is a single 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, supplied from the supply hole of the ink pipe 5, and 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 the outer peripheral surface of the ink roller 2 is in contact with the peripheral surface of the support cylinder in the plate cylinder 1. 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 giving start / trigger information to the paper feed motor 37 and the registration motor 41 shown in FIGS. 1 and 10 are arranged. That is, as shown in FIG. 9, 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 attached at 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 the 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. 13, 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 the press roller shaft 21 a and is provided to extend 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 ends of the press roller shaft 21 a. (The front side of the paper is omitted) and is supported rotatably.
Note that the size and size of the plate cylinder 1 is greatly exaggerated as compared with that of the press roller 21, and in the embodiment, as disclosed in, for example, Japanese Unexamined Patent Application Publication No. 2003-200355, Needless to say, the ratio of the diameter of the press roller to the diameter of the plate cylinder is preferably 1: 2 or 1: 3 in order to easily make the peripheral speed the same as that of the plate cylinder. Of course, if the above-mentioned advantage is not desired, the circumferential length of the peripheral surface of the press roller 21 is simply larger 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 1. Longer ones may be used.

Each printing pressure arm 22 is substantially L-shaped, and 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 22 b that selectively engages with the locking claw 60 a of the locking member 60 is formed at the lower end of the printing pressure arm 22. The arm shaft 22a is rotatable at 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. 7). It is supported by.
The press roller 21 is formed of, for example, nitrile rubber (NBR), which is an elastic body having oil resistance, and at least the outer peripheral surface of the rubber is a film having a fine uneven surface treatment, for example, For example, glass beads as glassy fine particles, which are the same as those used 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.

  The press roller 21 is not applied to the divided plate-making master 8X or the plate-making master 8Y on the plate cylinder 1 via the printing pressure range varying means 28, the locking means 64 and the printing pressure arms 22 shown in FIGS. The printing position shown in FIGS. 3 and 4 that presses the printing paper 36 or the surface-printed paper 36a and the non-printing position including the initial position shown in FIGS. 1 and 2 away from the printing position are configured to be displaceable. Has been. As described above, the pair of printing pressure arms 22 is configured to be displaceable so as to rotatably support the press roller 21 and to allow the press roller 21 to contact and separate from the plate cylinder 1.

As shown in FIGS. 2 and 6, the press roller rotation driving mechanism 54 presses the press roller 21 at a rotational speed substantially the same as that of the plate cylinder 1 and in a direction opposite to the rotation direction of the plate cylinder 1. It has a function as a means drive means.
The press roller rotation drive mechanism 54 is set in view of the following points. This will be described with reference to FIGS. The paper 36 that is passed through the first half of the master plate 8X on the plate cylinder 1 that has been subjected to the plate making (front surface image 8A) is regulated by the registration roller pair 31 of the paper feed unit 30 at the leading edge of the paper 36. Since the sheet 36 is fed and inserted into the nip formed by the press contact between the plate cylinder 1 and the press roller 21, the positional deviation of the sheet 36 with respect to the front plate-making image 8A does not occur, but the second half of the latter half (back plate-making). The image 8B) is printed on the back surface of the front-side printed paper by the rotation of the press roller 21 that is rotationally driven from the plate cylinder 1 via the driving force transmission means (or, as described later, substantially the same circumference as the plate cylinder 1). Since the speed is regulated (by the rotation of the press roller 21 that is rotationally driven by a unique driving means (motor or the like) different from the plate cylinder 1), the divided prepress master 8X on the plate cylinder 1 is controlled by the press roller 21. and/ Alternatively, in order to prevent misalignment caused by sliding with the back surface of the printed sheet, the press roller is rotated so that the peripheral speed of the press roller 21 is substantially the same as the peripheral speed of the plate cylinder 1. A drive mechanism 54 is employed.

The press roller rotation drive mechanism 54 is rotatably supported by the arm shaft 22a, and via a driving force transmission means (not shown) (for example, a gear train or a combination of a pulley and an endless belt). A one-way clutch 59 is interposed between the toothed drive pulley 56 and the press roller shaft 21a so that the drive force can be transmitted only in the counterclockwise direction indicated by the arrow in the figure. It is mainly composed of a toothed driven pulley 57 provided, a toothed endless belt 58 stretched between the driving pulley 56 and the driven pulley 57, and the driving force transmitting means.
The one-way clutch 59 interposed between the press roller shaft 21a and the driven pulley 57 has a paper conveyance abnormality (such as jamming or jamming) when the double-sided stencil printing apparatus 300 forms a printed image on at least the back surface of the surface-printed paper 36a. When the paper rolls up to the plate cylinder 1), the press roller 21 is provided so that it can rotate freely so as not to apply a load to the drive system by rotating with its inertia (inertia).
The press roller rotation drive mechanism 54 shown in FIG. 6 exaggerates the arrangement positions and angles of the arm shaft 22a, the press roller shaft 21a, and the like, as compared with that shown in FIG.
The pressing means driving means is not limited to the press roller rotation driving mechanism 54, and instead of driving force transmitting means (rotation transmitting means) provided on the driving pulley 56 side and transmitting the rotational driving force of the main motor 20, for example, the driving pulley 56 You may comprise by the electric motor (not shown) as a drive means which drives directly. In this case, the press roller 21 adjusts the unprinted paper 36, the front-side printed paper 36a, or the single-side printed paper 36c to the divided master-making master 8X or the master-making master 8Y on the plate cylinder 1 in accordance with the timing of pressing. What is necessary is just to comprise so that it may be rotationally driven by an electric motor.

  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 5, a first printing pressure range pattern that applies printing pressure only to the surface region 1A corresponding to the surface plate-making image 8A in the divided plate-making master 8X 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 for applying 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 master-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 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 thereof is represented by a sign obtained by adding a numerical value “200” to the sign of the above, and the arm shaft 22a, the printing pressure arm pair 22, the pair of cam followers 241, the pair of printing pressure springs 242, and the printing pressure cam shaft. 244, 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. 13 and FIG.

As shown in FIGS. 2 and 3, each of the constituent elements 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 description on the front side of the paper is omitted by describing the components on the back side of the paper as a representative. If the printing pressure range variable means 28 does not need the advantages as described above, the constituent elements of the printing pressure range variable means 28 are, 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 pivots 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 come into contact with 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 swung and urged clockwise around the arm shaft 22 a, and the press roller 21 is urged in a direction in which it is pressed against the outer peripheral surface of the plate cylinder 1. ing. A notch 22b that can be engaged with the locking claw 60a of the locking member 60 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 rotatably supported by a drive cam (45) and a main body frame attached to a printing pressure cam shaft 244, that is, the cam shaft (44) shown in FIG. The rotational force from the plate cylinder drive means (121), that is, the main motor 20, is transmitted through the transmission gear (47) attached to the support shaft (46), and is rotated in the clockwise direction 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 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 area between the press roller 21 and the plate cylinder 1 includes 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 that of the surface region 1A (see the printing pressure range pattern I shown in FIG. 5) so that all the ranges are combined (see the printing pressure range pattern III shown in FIG. 5). 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. 5).

As shown in FIGS. 2 and 3, the locking means 64 is a locking means for holding the press roller 21 in the non-printing position shown in FIGS. The locking means 64 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 that engages with each other is formed. One end of a tension spring 63 that urges the engaging claw 60 a in a direction to always engage with the notch 22 b of the printing pressure arm 22 is locked to the other end portion of the locking member 60. 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 drawing 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. 5 is an expanded view of the printing pressure range of the press roller 21 for easy understanding. In FIG. 5, 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 referred to as the leading edge blank portion sandwiched and fixed by the clamper 7 of the plate cylinder 1 (not shown), 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 the double-sided continuous printing mode or A3 by applying 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. In order to execute the single-sided printing mode, 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. 13, and the small diameter portion of the cam plate 243A faces the cam follower 241. It is driven to rotate.

  At the time of front surface printing, the control device 100 is configured such that the first surface printing and the A4 single-sided printing mode are performed, which is printed as the printing pressure range pattern I and corresponding to the area portion of the surface plate-making image 8A. When the printing pressure range varying means 28 is actuated by the command from the cam plate 243B, the cam plate 243B is selected, and the printing pressure is then released in the intermediate unmade region 8C so that the small diameter portion of the cam plate 243B faces the cam follower 241. It is driven to rotate.

At the time of printing on the back side, the printing pressure range variable means 28 is operated according to a command from the control device 100 so that the printing surface pattern II is formed and the second side printing and the final paper printing mode are executed. Then, the cam plate 243C is selected, and the large diameter portion of the cam plate 243C is opposed to the cam follower 241 so that the printing pressure is released in the region of the first surface plate-making image 8A, and then the small diameter of the cam plate 243C is selected. It is rotationally driven so that the portion 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 multi-stage 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. The configuration is not limited to the above, and for example, an emergency pressing release means (79) shown in FIGS. 1 to 4 of JP-A-2003-237030 may be applied.

  1-4, FIG. 7 and FIG. 8, the paper re-feed unit 48 is sometimes referred to as a front end portion (hereinafter referred to as “front end”) including the front end of the front surface printed paper 36a delivered from the printing unit 16. ) In the vicinity of the moving position P1 as the first position in the vicinity of the nip portion 16a of the printing unit 16, and the initial position as the second position in the vicinity of the upstream side of the refeeding unit 45 lower than the moving position P1. A movement guide 81 serving as a sheet holding means for releasing the front end of the surface-printed sheet 36a at the position P2 (or standby position P2), and the movement guide 81 between the movement position P1 and the initial position P2 as shown in FIG. When the moving means 87 for reciprocating movement and the movement guide 81 occupy the movement position P1 as shown in FIG. 8, the movement guide 81 is opened once, and then the front end of the surface printed paper 36a is clamped. Operate and move When the id 81 occupies the initial position P2, the disengagement cam 98 and the disengagement pin 99 constituting the operation timing control means that actuates the movement guide 81 to open the front end of the front surface printed paper 36a, and FIGS. As shown in FIG. 4 and the like, the surface-printed paper 36a delivered from the movement guide 81 is temporarily held, and then the surface-printed paper is sent toward the press roller 21 and reversed by the press roller 21 to be printed. 16 and a paper re-feeding means 45 for re-feeding toward the paper 16.

  The movement guide 81 is integrated with a clamping table 81f that clamps and places the front end of the surface-printed paper 36a, and a clamping table 81f that is downstream of the paper-printing direction Xa of the surface-printed paper 36a fed from the nip portion 16a. A pair of end fences 81d having a paper contact surface 81e that contacts the front end of the surface-printed paper 36a formed on the front and back sides of the paper surface of the clamping table 81f and integrated in the reciprocating direction. Four projections 81c as guided portions formed on the surface, clamp claws 81b as a clamping member that can be opened and closed with respect to a clamping base 81f that clamps the front end portion of the surface-printed paper 36a, and a base of the clamp claws 81b An oscillating clamp shaft 81a for attaching and fixing the end portion (a predetermined angle is rotatable), and a clamping base for supporting the clamp shaft 81a so as to be able to rotate a predetermined angle. A pair of bearing brackets 81g shown in FIG. 7 that are integrally attached to both side ends of If and the free end of the clamp pawl 81b are pressed against the upper surface of the clamping base 81f. It mainly comprises a torsion coil spring (not shown) as means, and a pair of upper and lower release levers 82 and a lower release lever 83 shown in FIG. 8 attached and fixed to the back side of the paper surface of the clamp shaft 81a.

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 guide grooves 88 formed in the case 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 out from the 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. The clamp claw 81b is a metal or resin thin plate member that extends and is fixed in the paper width direction Y of the clamp shaft 81a so as to sandwich the front end of the surface-printed paper 36a fed from the nip portion 16a. Become. A mounting portion 84 shown in FIG. 7 is integrally provided at a lower portion of the clamping table 81 f on the back side of the paper surface, and this mounting portion 84 is fixed to a timing belt 89 that constitutes the moving means 87.
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.

According to the movement guide 81 of this embodiment, the surface printing is provided by including the clamp claw 81b inclined with an acute rising angle with respect to the sheet traveling direction Xa of the surface printed sheet 36a fed from the nip portion 16a. When a load or the like is applied in the direction in which the surface-printed paper 36a is removed during conveyance of the used paper 36a, the moment of increasing the clamping force (pressing force), that is, the moment for rotating the clamp pawl 81b counterclockwise is generated. Therefore, the clamping force (pressing force) increases to prevent the sheet 36a from coming off, and the clamping force as a biasing force of a torsion coil spring (not shown) can be set small, and it is not necessary to make it firmly and inexpensively. It has the advantage of being configurable.
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. 7, the moving means 87 is disposed outside the housing side plate 130b on the back side of the drawing. 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 and reverse movable 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. As the drive motor 94, for example, a stepping motor is preferably used from the viewpoint that the position control of the movement guide 81 and the variable control of the movement speed can be relatively easily performed with good accuracy. As described above, the driving motor 94 is the moving driving means of the moving means 87, the guide groove 88 is the guiding means of the moving means 87, 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. Driving force transmitting means for transmitting 94 driving force to the movement guide 81 is configured.
As shown in FIG. 3, FIG. 7, FIG. 7 and FIG. 8 in which the moving guide 81 clamps the front end of the surface-printed paper 36a through the driving force transmission means by forward / reverse driving of the driving motor 94, as indicated by a solid line. 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 (near the upper part of the rear side of the conveyance roller 107 of the refeeding conveyance device 104) 1 and 2 that open the front end of the front surface printed paper 36a, and reciprocate to selectively occupy the initial position (second position) indicated by the two-dot chain line in FIGS. .
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).
In the figure, in the vicinity of the second position immediately above the home position sensor 85, position detection for detecting that the moving guide 81 occupies the vicinity of the second position where the front end of the front surface printed paper 36a is held. A stop position detection sensor 86 as a means is provided.
The home position sensor 85 and the stop position detection sensor 86 are, for example, transmissive optical sensors. Based on the signals output from the sensors 85 and 86 when the light-shielding piece protruding below the mounting portion 84 of the movement guide 81 is selectively engaged with the home position sensor 85 or the stop position detection sensor 86, FIG. The CPU 101 shown in FIG. 13 recognizes that the movement guide 81 occupies the second position and the vicinity of the second position. Each of the sensors 85 and 86 is not limited to a transmissive optical sensor, and may be, for example, a reflective optical sensor or a limit switch as long as reliability such as erroneous detection is not desired.

  As shown in FIG. 8, 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. The clamp claw 81b is swung clockwise (rotated by a predetermined angle) via the release lever lower 83 and the clamp shaft 81a against the urging force of the first position, and then once released, 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 unit that operates so as to sandwich the front end of the front surface printed paper 36a. As shown in FIG. 8, when the movement guide 81 occupies the initial position P2, the release pin 99 comes into contact with the release lever upper 82 of the movement guide 81, thereby resisting 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 nip portion 16a, and the clamp pawl 81b is rotated clockwise. If the release cam 98 is removed so as to be inserted into the open portion (open portion between the tip of the clamp claw 81b and the upper surface of the clamping base 81f) by swinging, even if the twist Even if the biasing force of the 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 conveying force applied to the front end of the surface-printed paper 36a by the nip portion 16a by the action of the release cam 98 described above. Is smoothly inserted into the open portion (the open portion 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 not affected by the strength of the paper. 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 can be kept in a stable state without meandering or skewing. It has the advantage that it can be transported satisfactorily and the printing image can be prevented from tilting during printing on the back side, or the resist from deteriorating due to tilting etc.In addition, the opening time when the front end of the front-side 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 printed sheet 36a can be favorably clamped at the front end.

  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. .

  Between each printing pressure arm 22, in addition to the press roller 21 constituting the refeed means 45, a refeed conveyance device 104, a refeed roller 51, a roller guide plate 50, and the like are disposed. In other words, the refeed unit 45 temporarily holds the surface-printed paper 36 a delivered from the movement guide 81 and conveys it at a predetermined timing between the press roller 21 and the refeed roller 51. Re-feeding conveying device 104 as a re-feeding conveying unit to be performed, and re-feeding as a re-feeding contact unit for abutting the surface printed sheet 36a conveyed by the re-feeding conveying device 104 to the press roller 21 The front surface printed paper 36 a provided near the outer peripheral surface of the press roller 21 on the right side of the paper roller 51 and the press roller 21 and brought into contact with the outer peripheral surface of the press roller 21 by the refeed roller 51 is guided to the printing unit 16. It is mainly composed of a roller guide plate 50 as a refeed guide means.

  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), and the drive shaft 107a is driven by a belt drive motor 105 connected via the drive gear. 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 formed of a stepping motor, for example, and is fixed to the main body frame side. The driven shaft 106 a is configured such that both ends thereof do not 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.

At the upstream end of the paper refeeding case 110 in the paper transport direction X, when the surface-printed paper 36 a is transported between the outer peripheral surface of the press roller 21 and the paper refeed roller 51 by the transport belt 108, The leading edge of the printed paper 36a (corresponding to the trailing edge when viewed in the paper transport direction X, but corresponds to the leading edge when viewed in the advancing direction of the front surface printed paper 36a, and is named as follows) Is temporarily held at a predetermined position in the vicinity of the press roller 21 (meaning an optimum position for inserting the front end of the surface-printed paper 36a between the outer peripheral surface of the press roller 21 and the refeed roller 51). A re-feed sensor 52 is provided as a surface printed sheet detecting means for this purpose. The re-feed sensor 52 includes a reflection-type optical sensor, and includes a front end (front right side of the front surface printed paper 36a illustrated in FIG. 4) and a rear end (left end of the front surface printed paper 36a illustrated in FIG. 4). ) Is detected, it also has a function as a conveyance abnormality detection means for detecting the presence or absence of conveyance abnormality of the front-side printed paper 36a.

The conveyance roller rear 107 and the conveyance 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 is configured so that the surface-printed paper 36 a delivered from the movement guide 81 is attracted 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 referred to as “suction fan 109”.

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 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. The roller guide plate 50 and the outer peripheral surface of the press roller 21 have a predetermined shape. 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. 13, the control target drive means of the refeed means 45 includes 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.

  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 peels the double-sided printed paper 36b from the pre-made master 8X on the plate cylinder 1, or the single-sided printed paper. 36c between the platen 1 and the peeling claw 170 for peeling the plate 36c from the plate-making master 8Y on the plate cylinder 1 and the front end of the double-sided printed paper 36b or the single-sided printed paper 36c peeled off by the peeling claw 170. The separation fan 171 that blows air to assist the separation action by the separation claw 170 and the one-side printed paper 36c and the double-side printed paper 36b separated by the separation claw 170 and the separation fan 171 are sucked and conveyed. The paper discharge conveyance device 152 to be discharged, and the conveyance abnormality of the double-sided printed paper 36b or the single-sided printed paper 36c disposed on the upstream side of the paper discharge conveyance device 152 (the jam caused by the paper being rolled up on the plate cylinder 1). A paper discharge sensor 65 serving as a conveyance failure detection means for detecting a jam) by catching on and outputting pathway during transport, is mainly composed of the above-described discharge tray 172.

  The peeling claw 170 is provided in the vicinity of the downstream in the 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 placed on the plate cylinder 1 in the vicinity of the outer peripheral surface of the plate cylinder 1 by a peeling claw displacing means (not shown) provided with a cam, a spring and the like that are driven to rotate in synchronization with the rotation of the plate cylinder 1. A separation position for forcibly separating the single-sided 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 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 includes a 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 on 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 the arrow.
The paper discharge sensor 65 also has a function of counting the normal number of printed sheets, and is disposed and fixed at the lower part of the opening between the paper discharge belts 158 divided into a plurality of parts. The paper discharge sensor 65 uses a reflection type optical sensor, and a light receiving element (not shown) emits light when the single-side printed paper 36c or the double-side printed paper 36b is sucked and conveyed by the paper discharge belt 158 at a predetermined timing. By receiving reflected light emitted from an element (not shown) and reflected by the back surface of each of the papers 36c and 36b, the passage of the papers 36c and 36b is detected to detect a paper conveyance abnormal state such as a jam. Is.
In FIG. 13, control target drive means of the paper discharge section 19 including the separation fan 171, the paper discharge belt drive motor 153, and the suction fan 159 in the paper discharge section 19 are collectively referred to as a paper discharge drive means 127.

  As shown in FIGS. 1 to 4, the switching guide 46 includes a nip portion 16 a 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 conveyance. It is disposed on a paper discharge path with the device 152. The switching guide 46 is made of a plate material having substantially the same width as that of 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 switching guide 46 has a free end portion formed in an acute cross section when the solenoid 47 as the switching driving means shown in FIGS. 2 and 13 operates against the urging force of a tension spring as urging 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 a 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.

Compared with the plate discharging apparatus (5) shown in FIG. 1 of the above-mentioned Japanese Patent Application Laid-Open No. 2004-224479, the plate discharging unit 17 differs only in arrangement and is substantially the same in configuration. Keep on.
In FIG. 13, a plate removal motor (not shown) of the plate release unit 17, a moving unit (not shown), and a control target drive unit of the plate release unit 17 including a lift motor (not shown) are collectively referred to as a plate release drive unit 126.

  As shown in FIGS. 1 and 10, the paper feed unit 30 contacts the paper feed tray 35, which can stack the paper 36 so that the paper 36 can be fed out and can be moved up and down, and the paper 36 on the paper feed tray 35. A sheet feeding roller 33 and a separating member 34 as sheet feeding means for separating and transporting the sheet 36 one by one toward the nip portion of the pair 31a, 31b (hereinafter referred to as “registration roller pair 31”), and the sheet A sheet size detection sensor 117 serving as a sheet size detection unit that detects the sheet size 36 and a registration unit that feeds the sheet 36 at a predetermined timing between the outer peripheral surface of the plate cylinder 1 and the press roller 21. And a registration roller pair 31 and the like.

  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. A state in which the upper layer contacts the paper feed roller 33 with a predetermined pressing force (a pressing force capable of transporting the paper 36), that is, a state in which the paper 36 contacts with a pressing force within a range in which the paper 36 can be transported in conjunction with increase / decrease of the paper 36. It is lifted while holding. The paper feed tray 35 has a structure in which many paper types and paper sizes can be used, and the paper stacking capacity thereof is, for example, a paper size A3 (horizontal placement: the user stands in front of the paper in FIG. And a structure suitable for a stencil printing apparatus that can stack 500 sheets or more of paper 36 of paper size A4.

In the paper feed tray 35, a pair of side fences (not shown) for positioning and aligning both side edges of the paper 36 according to the paper size is disposed so as to be movable in the paper width direction orthogonal to the paper transport direction X.
In the vicinity of the lower portion of the paper feed tray 35, paper length size detection sensors 117a, 117b, and 117c (both are made of a reflective optical sensor) for detecting the length of the fed paper 36 and the fed paper 36 In the figure, a paper width size detection sensor (not shown) that detects the paper width on the front side and the back side of the paper surface (for example, a transmissive optical sensor that detects the paper width in conjunction with the movement of the pair of side fences in the paper width direction) Are provided). The paper length size detection sensors 117a, 117b, and 117c and the paper width size detection sensor detect the size of the fed paper 36. Hereinafter, these are collectively referred to as the paper size detection sensor 117.
In the paper feed tray 35, a pair of side fences (not shown) for positioning and aligning both side edges of the paper 36 in accordance with the paper size is disposed movably in the paper width direction Y.

  In the vicinity of the lower portion of the paper feed tray 35, paper length size detection sensors 117a, 117b, and 117c (both are made of a reflective optical sensor) for detecting the length of the fed paper 36 and the fed paper 36 In the figure, a paper width size detection sensor (not shown) that detects the paper width on the front side and the back side of the paper surface (for example, a transmissive optical sensor that detects the paper width in conjunction with the movement of the pair of side fences in the paper width direction) Are provided). The paper length size detection sensors 117a, 117b, and 117c and the paper width size detection sensor detect the size of the fed paper 36. Hereinafter, these are collectively referred to as the paper size detection sensor 117.

As shown in FIGS. 1 and 10, the paper feed roller 33 is formed integrally with the paper feed roller shaft 33a, and one end of the paper feed roller shaft 33a is rotatably supported by the casing side plate. Yes. 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). 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.
Below the paper feed roller pulley 39, a paper feed motor 37 as a paper feed driving means for rotationally driving 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 10, the upper registration roller 31a is integrally formed with a metal registration roller shaft, and the lower registration roller 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.
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 the 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 remains in the paper transport path XA upstream from the position where the paper detection sensor 32 is disposed (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. 13, 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.

  As shown in FIG. 11, the image reading unit 18 includes the above-described document tray 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 transports 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 except for 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 vertical size 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 the 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 in the drawing of the document 133 (not shown) placed on the document 133 or the contact glass 135 to be conveyed. . 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 / 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 is exhausted.
In FIG. 13, the control target drive unit of the image reading unit 18 including the scanner motor and the document conveying motor of the image reading unit 18 is 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 test 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 configurations and functions of the various keys and various display devices of the operation panel 173 are the same as those described in, for example, the above-mentioned Japanese Patent Application Laid-Open No. 2004-224479 (Patent Document 8).
The display device 190 has a function as a conveyance abnormality notification unit or a conveyance abnormality display unit that performs display / notification regarding a jam. The conveyance abnormality notification means may be a warning sound notification means using a buzzer (not shown) or a voice notification means using a speaker.

Next, the main control configuration of the double-sided stencil printing apparatus 300 will be described with reference to FIG.
In FIG. 13, the control device 100 has a function and configuration as a control unit that mainly controls 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 backed up by a battery (not shown), etc. 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 and related data, the main motor 20 of the printing unit 16, the stepping motor 252 of the printing pressure range varying unit 28, the solenoid 62 of the locking unit 64, the plate making unit 15, the paper feed Control unit driving means provided in the image forming unit 30, the plate discharging unit 17, the paper discharge unit 19, the image reading unit 18, the suction fan 109 of the refeeding conveyance device 104 provided in the refeeding unit 45, and the belt driving motor 105. , The solenoid 47 of the switching guide 46, the operation of the drive motor 94 provided in the moving means 87, etc. Controls the printing apparatus 300 overall operation. The control device 100 also grasps the determination of the rotational position of the plate cylinder 1 and the detection of the printing speed, based on various plate cylinder position signals from the plate cylinder position detection sensor 29 generally shown in FIG. Is going.

The ROM 102 stores in advance an operation program for the entire duplex stencil printing apparatus 300, necessary related data, and the like, and this operation program is appropriately called by the CPU 101. As the relation data, when the printing pressure range varying means 28 is switched to the printing pressure range pattern II by the control function of the CPU 101 and the press roller 21 is operated to form a print image only on the back side of the front surface printed paper, the press roller The printing pressure range variable means 28 is switched to the printing pressure range pattern III to change the leading timing of the front end of the printed sheet by the conveying belt 108 of the refeeding conveying device 104 between the printing pressure range 21 and the refeeding roller 51. There is a start timing preset for each printing speed for controlling and starting the belt driving motor 105 of the paper refeeding / conveying device 104 so as to be delayed by a predetermined amount from the time of performing continuous duplex printing. These relational data are obtained and set for each printing speed in advance through experiments or the like, for example.
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.

The control device 100 (CPU 101) moves based on a signal related to jam from the paper discharge sensor 65 and a signal related to stop near the second position from the stop position detection sensor 86 while calling and referring to the operation program of the ROM 102. A function as a first control unit that controls the drive motor 94 of the moving unit 87 so that the guide 81 is held on the front surface printed sheet and the moving guide 81 stops near the second position. Have
At this time, the control device 100 (CPU 101) has a well-known function of determining that a jam has occurred when the passage of the single-side printed paper 36c or the double-side printed paper 36b is not detected at a predetermined timing by the paper discharge sensor 65. . In addition, on the basis of a signal relating to a jam from the paper discharge sensor 65, the control device 100 performs the above-described operations of the printing unit 16, the paper discharge unit 19, the paper feed unit 30, and the refeed unit 45 of the double-sided stencil printing device 300. The control target drive means is immediately stopped and has a function of causing the display device 190 of the operation panel 173 to display a jam. However, at this time, the main feature of the present embodiment is that the control device 100 performs control as described later without immediately stopping the driving motor 94 of the moving means 94.

  The control device 100 (CPU 101) calls and refers to the operation program of the ROM 102 and the related data, makes the printing pressure range variable means 28 switch to the printing pressure range pattern II, and prints the print image only on the back surface of the surface printed paper. When the press roller 21 is operated to be formed, the entry timing of the front end of the surface-printed paper by the transport belt 108 of the refeed transport device 104 between the press roller 21 and the refeed roller 51 is determined in the printing pressure range. As a second control means for controlling the belt driving motor 105 of the paper refeeding / conveying device 104 so as to be delayed by a predetermined amount from the time when the variable means 28 is switched to the printing pressure range pattern III to perform continuous duplex printing. It has a function.

Here, it supplements about the technical matter which supports that the control apparatus 100 (CPU101) which has a function as said 2nd control means is required.
In FIG. 5, for example, when the master size is A3, as described above, the maximum printing range is A3, that is, the front plate making image 8A that is the first surface, the intermediate non-plate making region 8C, and the back plate making that is the second surface. If the entire printing range including the image 8B is combined, the divided plate-making master 8X (the plate-making master for double-sided printing is used while pressing the entire region with the press roller 21 as in the normal single-sided printing range A3. ) In the first half (front plate making image 8A) of the first half of the printing range divided into two front and back sides, and the same paper size A4 on the second side (back plate making image 8B) of the second half. Printing can be performed on the back side of the front-side printed paper, and there is also a printing pressure range pattern mode in which the front half and the latter half are pressed separately.

In FIG. 6, symbols indicated by black triangles near the outer peripheral surface of the press roller 21 are for comparing changes in the rotational position (phase) of the press roller 21 between FIG. 6A and FIG. 6B. belongs to.
As shown in FIG. 6, in particular, when printing on the back side of a front surface printed paper (not shown) on the second side (back side plate-making image 8B), as shown in FIG. When the surface-printed paper is conveyed by being rotated by the press roller 21 while being separated from the outer periphery of the paper 1 and intermittently pressed against the plate cylinder 1 for printing, as shown in FIG. When the surface-printed paper is sent out while the roller 21 is in pressure contact with the plate cylinder 1, the pulleys 56 and 57 of the press roller rotation drive mechanism 54 and the endless belt 58 are as if they were parallel links. By performing the role, a separation position where the press-printed roller 21 and the refeed roller 51 pinch and feed the surface-printed paper, and the press-roller 21 presses against the plate cylinder 1 to press the surface-printed paper. Send The output position changes in such a manner that the phase of the press roller 21 slightly advances as indicated by the symbol A in FIG. 6B, and a print image position shift (hereinafter referred to as a position shift of the surface printed paper). (Hereinafter simply referred to as “image position shift”). This is a peculiar malfunction that occurs only when printing on the back surface of the front-side printed paper on the second surface (back plate making image 8B). The control device 100 (CPU 101) having the function as the second control means constitutes means for solving the above-mentioned problems.

  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. 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 the 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 operation example 1, the switching guide 46 is compared with the operations in the first surface printing, the second surface printing, the final paper printing mode, and the duplex continuous printing mode shown in FIG. The only difference is that the refeeding means 45 and the moving means 87 in the refeeding section 48 are performed in the non-operating state while occupying the first displacement position shown in FIG. From the point of operation example 2 and the contents disclosed in the above-mentioned patent documents 6 to 8 and the like, those skilled in the art can easily understand and implement it, and also from the point of avoiding redundant description with operation example 2 etc. described later Is omitted.

(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. 5 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.
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, and the control device receives these signals. 100 compares each signal. 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, a configuration in which enlargement or reduction is automatically performed in response to a command from the control device 100 to match the document size and the image size, and the display device 190 is configured to reduce or reduce the size of the image data. 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 a plate making start key 174 is pressed to generate a start signal and this is input to the control device 100, a series of operations from plate discharge to paper discharge 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, so that a paper feed position detection sensor (not shown) is turned on. When the control device 100 determines that the uppermost sheet 36 is ready to be fed by the detection, the sheet feeding device 30 enters a sheet feeding 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 removal 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 removal 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 used master that has been peeled off 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 the reading operation of the first original image for front side printing. 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 arranged 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 (not shown) and the thermal head driving circuit. As a result, the plurality of heating elements of the thermal head 11 are energized in a pulsed manner 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, while the master 8 is pulled out from the master roll 8a and 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, A surface plate-making image 8A for surface printing is formed in the first half of the master 8 (see the divided plate-making master 8X shown in FIG. 5).

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. 5 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 reverse plate-making image 8B for printing is formed (see FIG. 5).

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.

  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).

When the winding of the divided master-making master 8X around the plate cylinder 1 is completed, the plate cylinder 1 starts to rotate in the direction of the arrow shown in FIG. Is 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 to be 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 in a non-printing position, that is, an initial position separated from the outer peripheral surface of the plate cylinder 1. Yes.
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 surface printing in the regular double-sided printing operation, the printing pressure range 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 pattern I is selected. That is, the stepping motor 252 shown only in FIG. 13 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.

  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. 9 is engaged with the sheet feeding registration sensor 120, whereby the sheet feeding registration sensor 120 is turned on. 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. 10, 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, when 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, 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. The timing at which the registration motor 41 is activated, in other words, the timing at which the lower registration roller 31b is rotationally driven is the image of the surface plate-making image 8A in the plate cylinder rotation direction of the divided plate-making master 8X wound around the plate cylinder 1. It is set so as to reach a predetermined timing when the tip of the region reaches a position corresponding to the press roller 21.
The registration motor 41 is driven to rotate counterclockwise in FIG. 10, 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 by 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 243B 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. As the printing arm 22 is swung on the other end side, the outer peripheral surface of the cam follower 241 is opposed to the peripheral surface of the small diameter portion of the cam plate 243B rotating in synchronization with the rotation of the plate cylinder 1. At the rotational position of the cam plate 243B, the printing pressure arm pair 22 swings and rises clockwise around the arm shaft 22a by the urging force of the printing pressure spring 242.

  As a result, as shown in FIG. 5, the press roller 21 has a first surface of the divided plate-making master 8X whose outer peripheral surface is wound on the surface region 1A of the plate cylinder 1 shown in FIG. The paper 36 is pressed against the leading edge margin portion slightly to the left of the image 8A to be displaced to a printing position where printing pressure is applied, and a nip portion 16a is formed (press in the printing pressure range pattern I shown in FIG. 5). (See printing pressure ON timing by roller 21). At the same time, the press roller 21 rotates at a speed substantially equal to the peripheral speed of the plate cylinder 1 via the press roller rotation drive mechanism 54, so that the press roller 21 rotates in the direction opposite to the rotation direction of the plate cylinder 1. However, by continuously pressing the sheet 36 against the surface plate-making image 8A portion of the divided plate-making master 8X on the plate cylinder 1, 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 ink is applied thereto. So-called printing for filling 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. The ink in the ink reservoir 4 is adhered 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 and lowering operation of the press roller 21, the refeed conveyance device 104 swings about the drive shaft 107 a via the refeed housing 110.
Thus, plate printing corresponding to the surface plate-making image 8A in the divided plate-making master 8X on the plate cylinder 1 is performed, the plate cylinder 1 further rotates, and the portion near the rear end of the surface plate-making image 8A corresponds to the nip portion 16a. When the rotation 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, whereby the printing pressure arm 22 rotates counterclockwise about the arm shaft 22a, and the press roller 21 does not print. Holds the position occupied. At this time, since the solenoid 62 of the locking means 64 is already 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, the forward rotation drive is started), as shown in FIG. 3, the movement guide 81 is also printed on the surface 36a printed by the printing from the initial position P2. The four protrusions 81c are moved obliquely upward and to the right in the drawing so as to occupy the movement position P1 while being guided and moved along the guide groove 88 in order to sandwich the tip end of the guide. 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 reliably peeled off from the divided master-making master 8X (see FIG. 5) on the plate cylinder 1. The front end portion of the peeled surface-printed paper 36a is guided by the inclined surface 81ha of each guide 81h provided on the moving guide 81, and the gap between the upper surface of the clamping table 81f and the free end of the clamp claw 81b that is opened. The tip is abutted and aligned by being inserted into the portion and then abutting against the sheet abutting 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. 8, when the lower release lever 83 is disengaged from the contour peripheral surface of the release cam 98, the biasing force of the torsion coil spring causes the clamp claw 81b to swing counterclockwise and the free end of the clamp claw 81b. And the top end of the surface-printed paper 36a are clamped and clamped between the upper surface of the clamping table 81f. As described above, the moving guide 81 has the front surface printed paper 36a in a state where the front end of the front surface printed paper 36a is fixed and the front end of the front surface printed paper 36a abuts against the paper contact surface 81e. It moves to the left diagonally downward in the figure toward the initial position P2 at a moving speed that is substantially the same as the transport speed.
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 occupied by 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 movement guide 81 and the upper surface of the clamping table 81f by the operation of the moving means 87. As shown in FIG. 4, the movement guide 81 is moved to the position near the initial position P2 before the movement guide 81 reaches the initial position P2, that is, the upper surface of the release lever 82 does not come into contact with the release pin 99. It stops at the position detected by the stop position detection sensor 86 in a state where the leading end of the printed paper 36a is held and temporarily stands by.
At this time, the solenoid 47 is turned off when the rear end of the surface-printed paper 36a passes the switching guide 46, so that the switching guide 46 is driven by a shaft 47a as shown by a solid line in FIG. Is controlled to return to the first displacement position (initial position) and stop. In the state where the switching guide 46 is in the first displacement position (initial position) in FIG. 1, the plate cylinder 1 is rotated, and the reverse plate-making image 8B which is the second surface of the divided plate-making master 8X on the plate cylinder 1 is a press roller. When the control device 100 determines that the printing position timing corresponding to the front surface prepress image 8A on the first surface has come again after passing over 21, the printing operation corresponding to the above-described front prepress image 8A is started. . In the printing operation for the front side plate-making image 8A on the first surface, the movement guide 81 moves toward the home position and occupies the initial position P2, and this time, as shown by a two-dot chain line in FIG. When the release lever upper 82 comes into contact with the release pin 99, the clamp pawl 81b is swung clockwise, so that the front end of the front 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 suction fan 109 of the re-feed conveyance device 104, the surface-printed paper from between the free end of the clamp claw 81b and the upper surface of the clamping table 81f It is desirable that the leading end of 36a is opened in order to reduce the fluctuation of the sheet 36a, improve the positional accuracy of the sheet 36a, and keep the subsequent printing position deviation to a minimum.

  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 36a (the right end side on the conveyor belt 108) is close to the nip portion to be formed between the press roller 21 and the refeed roller 51, that is, the refeed sensor 52. Then, the belt drive motor 105 is temporarily stopped driving, and the rotation of the conveyor belt 108 is temporarily stopped.

  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 that enables printing on the back surface of the finished paper 36a has been reached, the belt drive motor 105 is synchronized with the rotation of the plate cylinder 1 to a predetermined position. In addition, by starting again at a specific timing delayed by a predetermined amount from the time of continuous duplex printing, the rear 107 of the transport roller starts to rotate clockwise again, so that the transport belt 108 is printed on the surface-printed paper 36a. In a state where the back surface of the plate cylinder is sucked and held, it starts to rotate clockwise at a linear speed (conveyance speed) substantially the same as the peripheral speed of the plate cylinder 1.

At the same time, at the time of the second surface printing corresponding to the back side plate-making image 8B in the divided plate-making master 8X on the plate cylinder 1, and at the final paper printing mode in which only the back side printing in the regular double-sided printing operation described later is performed, The printing pressure range variable means 28 is controlled by a command from the control device 100 so that the printing pressure ON timing by the press roller 21 in the printing pressure range pattern II shown in FIG. 5 is selected. That is, the stepping motor 252 shown only in FIG. 13 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. And is controlled to be pressed by the press roller 21 at a position corresponding only to the second side rear plate-making image 8B on the divided plate-making master 8X on the plate cylinder 1 as will be described later.
At this time, as described above with reference to FIG. 6, the surface-printed paper 36a (not shown in FIG. 6) is re-attached to the press roller 21 as shown in FIGS. 6 (a) to 6 (b). Since it ascends while being nipped by the nip portion with the paper feed roller 51, it is as if it is parallel when it swings to a position corresponding to the second side rear plate making image 8B on the divided plate making master 8X on the plate cylinder 1. Since it is rotated and moved by the link, it is transported by the rotational movement amount (phase movement amount) A of the press roller 21 and is in an excessively advanced state, so that it corresponds to the predetermined amount delay timing to compensate for this. The conveyance belt 108 starts conveyance at a timing delayed by a distance corresponding to the movement amount A that is the rotation advance amount of the press roller 21.

The surface-printed paper 36a is re-supplied by rotating the press roller 21 counterclockwise via the press roller rotation drive mechanism 54 shown in FIG. While being sandwiched between the paper rollers 51, the plate is 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. It is conveyed while being turned upside down toward the nip portion 16a between the cylinder 1 and the press roller 21.
In parallel with this conveyance, when the predetermined rotation position of the plate cylinder 1, that is, 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 the rotation position corresponding to the nip portion 16a. When the small diameter portion of the cam plate 243C rotating in synchronism 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. 4, the back surface of the surface-printed paper 36a (upper surface in FIG. 4) is provided 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 to displace the printing position where the printing pressure is applied, and the nip portion 16a is formed by the urging force of the printing spring 242 to perform double-sided printing for printing (see the mark shown in FIG. 5). Pressure range Referring printing pressure ON timing by the press roller 21 in over emissions II).

  In this way, a plate on which double-sided printing has been performed in which the back side plate-making image 8B in the divided plate-making master 8X on the plate cylinder 1 is filled with ink and a back side printed image is formed on the back side of the front side printed paper 36a correspondingly. The double-sided printed paper 36b for attachment is reliably peeled off from the divided plate-making master 8X on the plate cylinder 1 by the air from the peeling claw 170 and the peeling fan 171 whose leading end approaches the outer peripheral surface of the plate cylinder 1. The peeled double-sided printed paper 36b falls downward and is sent to the paper discharge belt 158 of the paper discharge transport device 152, and is discharged in the direction of the arrow (counterclockwise) shown in FIG. While being attracted and held by the suction force of the suction fan 159 on the upper surface of the paper belt 158, it is transported to the downstream side in the paper transport direction X by the pair of paper discharge side fences 172a and 172b. While aligned with both side ends Te is discharged to the discharge tray 172.

  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 peripheral surface of the cam plate 243 </ b> C comes into contact with the cam follower 241, that is, 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 for the next trial printing or 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.

Although description will be omitted, during feeding or printing, the platen roller 9 and the transport roller pair 13 resume rotation, and the leading end of the cut master 8 is fed toward the nip portion of the transport 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 state of waiting for plate making in preparation for 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 rotationally driven at the set printing speed, and double-sided printing is performed in the same process as the plate printing.
Next, a description will be given of a double-sided printing operation in which the front-side printed paper 36a printed by the printing unit 16 is printed for the set number of sheets while being replaced with the front-side printed paper 36a temporarily held on the conveyance belt 108.
In the set number of double-sided printing operations, the first front-side printed paper 36a (hereinafter simply referred to as “first front-side printed paper 36a”) is re-feeded and transported, as in the plate-making operation described above. Since it is the same up to the point where the leading edge is detected by the re-feed sensor 52 after being sucked and held by the conveyor belt 108 of the apparatus 104, 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 plate cylinder 1 and the press roller 21 at a predetermined timing through the same detailed operation as described above.

  As shown in FIG. 3, the movement guide 81 occupies the movement position P <b> 1 so as to sandwich the leading edge of the second front surface printed sheet 36 a from the initial position P <b> 2 through the same detailed operation as described above. When the release lever lower 83 rides on the release cam 98 as shown by the solid line in FIG. 8, the clamp claw 81b swings clockwise and contacts the upper surface of the clamping table 81f. Stop and wait in the released state. 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. 5) on the plate cylinder 1 is peeled off in the same manner as described above. It is guided by the movement guide 81 and inserted into a gap portion between the upper surface of the clamping table 81f and the free end of the clamp claw 81b that is open, and then comes into contact with the paper contact surface 81e of the end fence 81d so that the tip thereof is It is abutted and aligned. When the front end of the front surface printed paper 36 is inserted into the gap portion between the upper surface of the clamping table 81f and the free end of the clamp claw 81b, the movement guide 81 is operated through the detailed operation of the movement means 87 similar to that described above. Starts moving toward the initial position P2 at substantially the same speed as the transport speed of the second front surface printed paper 36a.

At this time, in FIG. 8, when the lower release lever 83 is disengaged from the contour peripheral surface of the release cam 98, the detailed operation similar to that described above is performed between the free end of the clamp claw 81b and the upper surface of the clamping table 81f. The leading edge of the second front surface printed paper 36a is clamped. The movement guide 81 moves diagonally 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 surface printed paper 36a with the tip of the second front surface printed paper 36a fixed.
When printing on the second sheet 36 corresponding to the surface plate-making image 8A in the divided plate-making master 8X on the plate cylinder 1, and subsequently, the first sheet reversely conveyed by the re-feeding 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 front-side printed paper 36a, as in the normal single-sided printing mode (see operation example 1), 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 III shown is selected. That is, based on the detection signal of the leading edge of the second 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 controls the solenoid 62 of the locking means 64. A command signal for energization is transmitted to a solenoid drive circuit (not shown) related to the solenoid 62, whereby the solenoid 62 is turned on to operate the cam plate 243A of the printing pressure range varying means 28. At the rotational position of the cam plate 243A where 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 through the detailed operation described above. The printing pressure arm pair 22 is swung clockwise by the urging force of the printing pressure spring 242 around the arm shaft 22a.

  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, it is not the timing that the belt driving motor 105 is synchronized with the rotation of the plate cylinder 1 to a predetermined position and that is delayed by a predetermined amount set for each printing speed as in the second surface printing. By starting again at the normal setting timing set for each printing speed, the rear 107 of the conveying roller starts to rotate clockwise again, so that the conveying belt 108 of the surface-printed paper 36a is rotated. A surface while holding adsorbed peripheral speed of the plate cylinder 1 starts to be rotated clockwise about the same linear speed (conveying speed). At this time, the surface that was held in contact with the nip portion between the press roller 21 and the refeed roller 51 by rotating the press roller 21 counterclockwise via the press roller rotation drive mechanism 54. While the front end of the printed paper 36a is sandwiched between a press roller 21 that rotates counterclockwise and a refeed roller 51 that rotates in the clockwise direction, the peripheral speed of the plate cylinder 1 is almost the same. Nip formed at the peripheral speed and guided by the roller guide plate 50 so as to be conveyed along the outer peripheral surface of the press roller 21 and the plate cylinder 1 and the press roller 21 are already in pressure contact with each other. It is conveyed toward the part 16a while being turned upside down.

The detailed operation of the printing pressure range varying means 28 at this time is performed as described above, and the second sheet is pressed against the front plate making image 8A in the divided plate making master 8X on the plate cylinder 1 by the press roller 21. With the press roller 21 continuously occupying the printing position, the sheet is re-supplied to the back plate-making image 8B in the divided plate-making master 8X on the plate cylinder 1 through the intermediate unmade region 8C. The back surface of the first front surface printed paper 36 a that is reversed and conveyed by the paper means 45 is pressed by the press roller 21.
On the other hand, the second surface-printed paper 36a is in an initial position through the above-described detailed operation of the moving means 87 in a state where the tip is clamped and fixed between the clamp claw 81b of the movement guide 81 and the clamping table 81f. When the movement guide 81 occupies the initial position P2 and is stopped toward the initial position P2, the release lever upper 82 comes into contact with the release pin 99 as shown by the two-dot chain line in FIG. By swinging clockwise, the leading end 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 shown 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 plate-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 at the outer peripheral surface of the plate cylinder 1 in the same manner as the paper discharge operation at the time of printing in the double-sided printing mode. The peeled claw 170 and the peeling fan 171 approaching the sheet are surely peeled off from the divided master-making master 8X on the plate cylinder 1, and the peeled double-side printed paper 36b falls downward and is discharged to the paper discharge conveyance device 152. To the upper surface of the paper discharge belt 158 rotating counterclockwise and attracted by the suction force of the suction fan 159 and conveyed to the downstream side in the paper conveyance direction X while being sucked and held, and the paper discharge tray It is discharged to 72.

  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, the sheet is conveyed while being turned upside down toward the nip portion 16a.

  As with 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, for the set number N of sheets set with the numeric keypad 179, the same printing operation as described above is repeated until the (N-1) th sheet. When performing double-sided printing on the back surface 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 by the press roller 21 only to the back surface pre-printed image 8B in the divided plate 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 for the set number N is completed, and the double-sided stencil printing apparatus 300 enters a print standby state.
At this time, at the time of the second side printing corresponding to the back side plate-making image 8B in the divided plate-making master 8X on the plate cylinder 1, and in the final paper printing mode in which only the back side printing is performed in the regular double-sided printing operation described later, the control device 100 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. 13 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. And is controlled to be pressed by the press roller 21 at a position corresponding only to the second side rear plate-making image 8B on the divided plate-making master 8X on the plate cylinder 1 as will be described later.
At this time, as described above, the surface-printed paper 36a is transported and advanced by the rotational movement amount A of the press roller 21, so that the predetermined amount set for each rotational speed to compensate for this. The nip portion between the press roller 21 and the refeed roller 51 is conveyed by the transport belt 108 at the timing delayed by a distance corresponding to the movement amount A that is the rotation advance amount of the press roller 21 corresponding to the delay timing. Transport is started toward

  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.

Next, an operation when a paper conveyance abnormality such as a jam occurs at the time of forming a printed image on the back surface of the front-side printed paper 36a or in the paper discharge process will be described.
When a reverse side-printed double-sided printed paper 36b is stuck on the plate cylinder 1 and jammed due to roll-up that is not ejected or a jamming jam occurs on the paper ejection belt 158 in the middle of the paper ejection path, The control device 100 (CPU 101) determines that the passage of the double-side printed paper 36b is not detected at a predetermined timing by the paper discharge sensor 65 (a signal related to a jam from the paper discharge sensor 65). A jam command signal is transmitted from the control device 100 to each of the control target drive units of the printing unit 16, the paper discharge unit 19, the paper supply unit 30, and the refeed unit 45 of the double-sided stencil printing apparatus 300. The controlled object driving means is immediately stopped, and the display device 190 of the operation panel 173 does not indicate that a jam has occurred and does not indicate a jam location or the like. That.

At the same time, a jam command signal from the control device 100 is transmitted to the drive motor 94 via the stepping motor drive circuit of the moving means 87, so that the surface between the clamp claw 81b of the moving guide 81 and the clamping table 81f The moving guide 81 is stopped in the vicinity of the second position while the leading end of the printed paper 36a is held and held.
Therefore, after confirming the jam display and its location displayed on the display device 190, the user performs jam processing on the jam location at the upper part in the double-sided stencil printing device 300, and then again presses the plate-making start key 174, for example. By inputting the start signal to the control device 100, double-sided printing is performed in the mode using the surface-printed paper 36a sandwiched and held by the movement guide 81 described above. Detailed operations in this mode can be easily understood and carried out by those skilled in the art, and a description thereof will be omitted.

  In the printing and test printing in the duplex printing mode in the operation example 2, the surface-printed paper 36a is in the vicinity of the initial position P2 before the movement guide 81 reaches the initial position P2, that is, the release lever upper 82 is the release pin 99. Although it has been described that the front end of the surface-printed paper 36a is held by the movement guide 81 without being in contact with the position detected by the stop position detection sensor 86 and temporarily stands by, This is not a necessary operation because it is not when a paper conveyance abnormality such as a jam occurs during the formation of a printed image on the back surface of the front surface printed paper 36a or in the paper discharge process. 81 may be moved to the initial position P2.

At the time of printing in the duplex printing mode and at the time of trial printing, after the printing pressure cam shaft 244 is moved so that the cam plate 243B can come into contact with the cam follower 241, the first sheet 36 is removed from the sheet feeding unit 30. After feeding and printing the surface prepress image 8A on the surface of the first sheet 36 and guiding it from the moving guide 81 to the conveying belt 108, the cam plate 243A can come into contact with the cam follower 241. In this way, the printing cam shaft 244 is moved so that the second sheet 36 is fed from the sheet feeding unit 30, and the surface plate-making image 8 A is printed on the surface of the second sheet 36, and this is output to the sheet discharge tray. The first front-side printed paper 36a is fed from the conveyor belt 108, the second plate-making image 65B is printed on the back surface of the paper, and then discharged to the paper discharge tray 172. Open 200 -200645 discloses light of the contents described in (Patent Document 6), it is needless to say that may be operated as follows.
That is, after the printing pressure cam shaft 244 is moved so that the cam plate 243B can come into contact with the cam follower 241, one sheet 36 is fed from the sheet feeding unit 30, and the surface plate-making image is formed on the surface of the sheet 36. After printing 8A and guiding and transferring it from the moving guide 81 to the conveyor belt 108, the printing cam shaft 244 is moved so that the cam plate 243C can come into contact with the cam follower 241, and the outer peripheral surface of the press roller 21 is moved. Is brought into pressure contact with the outer peripheral surface of the plate cylinder 1 and then the belt at a timing slightly earlier than the front end of the image area of the back plate-making image 8B in the plate cylinder rotation direction of the divided plate-making master 8X reaches the position corresponding to the press roller 21. The drive motor 105 is activated, and the first surface-printed paper 36a temporarily held on the conveyor belt 108 is fed with the press roller 21 and the refeed paper low. It reversed and conveyed by the press roller 21 by that sending the nip portion 51, may be this by printing the back side perforated image 8B on the back surface configured so as to discharge the discharge tray 172. With this configuration, printing and trial printing can be covered with a single sheet of paper 36, and costs can be reduced.

  As described above, according to the present embodiment, the double-sided printing device (1) disclosed in, for example, Japanese Patent Application Laid-Open No. 2004-224479 (Patent Document 8) is not only provided with the advantages and effects described above. Compared to the above, the re-feeding conveyance device 104 in the re-feeding means 45 temporarily holds the surface-printed paper 36a, and then presses the surface-printed paper 36a at a predetermined timing as a pressing means. The refeeding positioning member (24) as shown in the same publication is provided by feeding to the roller 21 and reversing by the press roller 21 and refeeding toward the nip portion 16a. It is possible to remove the auxiliary tray (8) as a refeed storage means without the need for it, thereby further reducing the number of components and realizing a simple duplex printing apparatus. It is those that can be. 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.

As described above, according to the present embodiment, when a printed image is formed on the back side of the front-side printed paper during double-sided printing (hereinafter sometimes referred to as “back side printing”) and in the paper discharge process, it is transported due to some trouble. When an abnormal jam occurs, the control device 100 causes the movement means 87 to stop in the vicinity of the second position while the movement guide 81 is used to hold the front surface printed paper. By controlling the drive motor 94, in other words, printing is resumed using the front surface printed paper held by the movement guide 81. It is no longer necessary to remove the lower surface printed paper staying in the middle of conveying the means, and it becomes possible to reduce the waste surface printed paper. In addition, since the front-side printed paper is held and held by the movement guide 81 during backside printing, the front-side printed paper does not move during jam processing, and the front-side printed paper that is reused after printing resumes can be moved. For example, similar jamming does not occur, and image misalignment due to skew or the like does not occur. Further, since the drive motor 94 is constituted by a stepping motor, it is possible to easily and accurately control the position of the sheet holding means when resuming printing using the surface-printed sheet.
Further, according to the present embodiment, the control device 100 switches the printing pressure range variable means 28 to the printing pressure range pattern II, and operates the press roller 21 so as to form a print image only on the back surface of the front surface printed paper. When the leading edge of the surface printed paper by the conveying belt 108 of the refeed conveyance device 104 between the press roller 21 and the refeed roller 51 is entered, the printing pressure range variable means 28 is used to determine the printing pressure range. By controlling the belt driving motor 105 of the paper refeeding / conveying device 104 so as to be delayed by a predetermined amount from when performing double-sided continuous printing by switching to the pattern III, in other words, a printed image only on the back side of the front-side printed paper When the press roller 21 is operated so as to form a sheet, the entry timing of the front end of the surface-printed paper into the press roller 21 is delayed by a predetermined amount from the time of continuous duplex printing. Since it is configured so as to, and during the second surface plate with, as shown in FIG. 5, the image position deviation in the case of the back-side printing in the final paper printing mode is to be prevented.

(Second Embodiment)
14 and 15 show a double-sided stencil printing apparatus 300A according to the second embodiment. This double-sided stencil printing apparatus 300A is obtained by applying the present invention to the double-sided printing apparatus (1) shown in FIG. As shown in FIGS. 14 and 15, the double-sided stencil printing apparatus 300 </ b> A has a re-feed unit 48 replaced with a re-feeding unit 48 as compared with the double-sided stencil printing apparatus 300 of the first embodiment shown in FIGS. 1 to 13. The main difference is that the sheet feeding unit 48A is provided and the control device 100A is replaced with the control device 100A. The configuration of the double-sided stencil printing apparatus 300 </ b> A is the same as that of the double-sided stencil printing apparatus 300 except for the differences.

The refeed unit 48A is different from the refeed unit 48 of the first embodiment only in that it includes a refeed unit 45A instead of the refeed unit 45. Compared with the refeeding unit 45 of the first embodiment, the refeeding unit 45A temporarily replaces the refeeding conveyance device 104 with the front printed sheet 36a delivered from the movement guide 81. It has a refeed conveyance device 104A as a refeed conveyance device that holds and conveys it toward the press roller 21, and presses the front end of the surface printed paper 36a conveyed by the refeed conveyance device 104A. The auxiliary tray 208 provided with a stopper 224 as a refeed stop means for temporarily stopping the paper before being transferred to the roller 21 is newly provided, and the front surface printed paper 36a conveyed by the refeed conveyance device 104A. Is a re-feeding registration roller 223 that constitutes a re-feeding registration means that is displaceable between a contact position for contacting the press roller 21 and a separation position that is spaced from the contact position. A newly-provided point and a re-feed resist contact / separation means 260 constituting a re-feed resist means for displacing the re-feed resist roller 223 between the contact position and the separation position are newly added and the paper is re-feeded. The main difference is that the roller 51 is removed and a refeed sensor 208c is used instead of the refeed sensor 52.
The configuration of the refeed unit 48A other than the differences is the same as that of the refeed unit 48 of the first embodiment. That is, the refeed unit 48A includes a roller guide plate 50 and a moving guide 81 similar to those in the first embodiment, a moving unit 87 omitted in FIG. 14, a release cam 98 and a release pin as operating time control units, respectively. 99, a press roller rotation drive mechanism 54, and the like.

Compared to the refeed conveyance apparatus 104, the refeed conveyance apparatus 104 </ b> A has an auxiliary tray 208 integrally formed at the upper part of the upstream end (the right end side in FIG. 14) in the sheet conveyance direction X in the refeed casing 110. The only difference is that the resist function is removed from the formed point and the function of the paper refeeding transport device 104, and the other configuration is the same as that of the paper refeeding transporting device 104. That is, the refeed conveyance device 104A removes the sheet receiving plate (40) from the refeed conveyance unit (25) shown in FIGS. 1 to 3 of Japanese Patent Application Laid-Open No. 2004-224479 (Patent Document 8). The other points are substantially the same as those of the refeed conveyance unit (25).
The re-feeding registration roller 223 is shown in FIG. 2 of Japanese Patent Application Laid-Open No. 2003-200355 (Patent Document 6), and includes a re-feeding registration roller having a solenoid (33) and a tension spring (34). A mechanism similar to the mechanism (160) is displaced between a contact position indicated by a solid line in FIG. 14 and a separated position indicated by a two-dot chain line in FIG. The solenoid (33) is a solenoid 233 shown in FIG. 14 and FIG.
The re-feed sensor 208c is a reflection-type optical sensor, and detects the front end position of the surface printed paper 36a that comes into contact with or abuts against the stopper 224, and the rear end (of the surface printed paper 36a shown in FIG. By detecting (left end), it also has a function as a conveyance abnormality detection means for detecting the presence or absence of conveyance abnormality of the surface-printed paper 36a.

As shown in FIG. 15, the control device 100A differs from the control device 100 of the first embodiment only in that it has a CPU 101A instead of the CPU 101, a ROM 102A instead of the ROM 102, and a RAM 103A instead of the RAM 103. Others include a microcomputer having the same configuration as the control device 100.
CPU 101A of control device 100A (hereinafter sometimes simply referred to as “control device 100A”) is called from various signals from operation panel 173, detection signals from the various sensors provided on main body frame 130, and ROM 102A. Based on the operation program and related data, the main motor 20 of the printing unit 16, the stepping motor 252 of the printing pressure range varying unit 28, the solenoid 62 of the locking unit 64, the plate making unit 15, the paper feeding unit 30, the plate discharging unit 17, Each of the control target drive units provided in the paper unit 19 and the image reading unit 18, the suction fan 109 of the refeed conveyance device 104A provided in the refeed unit 45A, the belt drive motor 105, the solenoid 233, and the switching guide 46 Control each operation of the drive motor 94 provided in the solenoid 47 and the moving means 87, Controlling the surface stencil printing apparatus 300 overall operation. The control device 100A also determines the rotational position of the plate cylinder 1 and the detection of the printing speed based on various plate cylinder position signals from the plate cylinder position detection sensor 29 generally shown in FIG. Is going.

The ROM 102A stores in advance an operation program for the entire duplex stencil printing apparatus 300A, necessary related data, and the like, and this operation program is appropriately called by the CPU 101A. As the relational data, when the printing pressure range variable means 28 is switched to the printing pressure range pattern II by the control function of the CPU 101A and the press roller 21 is operated so as to form a print image only on the back surface of the front surface printed paper, the stopper 224 is used. The contact timing at which the front end of the surface-printed paper that is temporarily stopped by the contact with the press roller 21 is set to be higher than when the printing pressure range variable means 28 is switched to the printing pressure range pattern III to perform continuous duplex printing. There is a related to a start timing preset for each printing speed for controlling and starting the solenoid 233 of the refeed resisting means so as to delay by a predetermined amount. These relational data are obtained and set for each printing speed in advance through experiments or the like, for example.
The RAM 103A has a function of temporarily storing calculation results of the CPU 101A, 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.

As in the first embodiment, the control device 100A (CPU 101A) calls the operation program stored in the ROM 102A and refers to the jam signal from the paper discharge sensor 65 and the vicinity of the second position from the stop position detection sensor 86. Based on the signal related to the stop, the drive motor 94 of the moving means 87 is controlled so that the movement guide 81 is held by the movement guide 81 and the movement guide 81 stops near the second position. It has the function as the 1st control means to do.
At this time, the control device 100A (CPU 101A) has a well-known function of determining that the passage of the single-side printed paper 36c or the double-side printed paper 36b is a jam when the paper discharge sensor 65 does not detect the passage at a predetermined timing. . In addition, the control device 100A, based on a signal relating to a jam from the paper discharge sensor 65, the printing unit 16, the paper discharge unit 19, the paper supply unit 30, and the refeed unit 45A of the double-sided stencil printing device 300A. It also has a function of stopping the controlled object drive means and causing the display device 190 of the operation panel 173 to display a jam. However, at this time, as in the first embodiment, the control device 100A performs the above-described control without immediately stopping the driving motor 94 of the moving means 94, which is a major feature of this embodiment. .

The control device 100A (CPU 101A) calls and refers to the operation program of the ROM 102A and the related data, makes the printing pressure range variable means 28 switch to the printing pressure range pattern II, and prints the print image only on the back surface of the front surface printed paper. When the press roller 21 is operated to be formed, the printing pressure range variable means 28 is used as the printing pressure range pattern for the contact timing when the front end of the surface printed paper temporarily stopped by the stopper 224 contacts the press roller 21. It has a function as a second control means for controlling the solenoid 233 of the refeed resisting means so as to be delayed by a predetermined amount compared with the case of performing double-sided continuous printing by switching to III.
As the displacement driving means for displacing the refeed resist roller 223 as the refeed resist means so as to occupy the contact position, in addition to using the solenoid 233, for example, a DC motor or a stepping motor via a gear train, Needless to say, a rotary solenoid or the like may be used.

  Each operation during single-sided printing and double-sided printing of the double-sided stencil printing apparatus 300A automatically executed under the control apparatus 100A described above is apparent from the functions of the control apparatus 100A. Those skilled in the art can easily understand and implement the technology disclosed in Japanese Patent Application Laid-Open No. 2003-200355 (Patent Document 6), and the description thereof will be omitted.

As described above, according to the present embodiment, when a jam as a conveyance abnormality occurs due to some trouble during the back side printing and the paper discharge process during double-sided printing, the control device 100A uses the movement guide 81 to perform front surface printing. By controlling the drive motor 94 of the moving unit 87 so that the moving guide 81 stops near the second position while the sheet is held, the same advantages as in the first embodiment can be obtained.
Further, according to the present embodiment, the control device 100A operates the press roller 21 to form the print image only on the back surface of the front surface printed paper by causing the printing pressure range variable means 28 to switch to the printing pressure range pattern II. When printing, double-sided continuous printing is performed by switching the printing pressure range variable means 28 to the printing pressure range pattern III for the contact timing at which the leading edge of the surface printed paper temporarily stopped by the stopper 224 contacts the press roller 21. In other words, when the press roller 21 is operated so as to form a print image only on the back side of the front-side printed paper by controlling the solenoid 233 of the re-feeding registration means so as to be delayed by a predetermined amount from the time of performing Since the entrance timing of the front end of the printed sheet on the front surface to the press roller 21 is configured to be delayed by a predetermined amount from the time of continuous duplex printing, 5 and when the second side plate with, as shown in, the image position deviation in the case of the back-side printing in the final paper printing mode is to be prevented.

  The sheet holding unit, the moving unit, and the operation timing control unit are not limited to the moving guide 81, the moving unit 87, the release cam 98, and the release pin 99 described in the first and second embodiments, but the first and second described above. If it is not necessary to desire the advantages and effects as in the above embodiment, for example, the paper front end holding member (168) shown in FIGS. 30 to 34 of Japanese Patent Laid-Open No. 2004-224479 (Patent Document 8), It may be a holding member moving means (143), a guide plate (56), a clamper releasing member (169), and the like.

  The press roller rotation drive mechanism 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.

As described above, in Embodiments 1 and 2, it can be said that the double-sided printing method according to claims 1 to 3 described in the column of means for solving the problem is used.
In consideration of the technical contents of the first and second embodiments described above, in this specification, in addition to the invention according to claims 1 to 7 described in the column of means for solving the problems, double-sided printing in which image positional deviation does not occur. It is apparent that the following first to third inventions are also disclosed for the purpose of providing a method and a duplex printing apparatus.
That is, the first invention relates to a plate cylinder on which a plate-making master for double-sided printing in which two first and second plate-making images are formed side by side along the rotation direction of the plate cylinder, and A printing unit having pressing means that can be moved toward and away from the plate cylinder, and a printing image on the surface of the printing unit corresponding to one of the first plate-making image and the second plate-making image. A front-surface-printed paper that has been re-feeded from the re-feeding portion, and has a re-feed portion that re-feeds the formed front-surface-printed paper temporarily In the double-sided printing method using a double-sided printing apparatus that forms a printed image corresponding to the other of the first plate-making image and the second plate-making image on the back surface of the plate, the pressing means is substantially the same as the plate cylinder Driven at a peripheral speed, a printed image should be formed only on the back side of the front side printed paper. When operating the pressing means, it is characterized in that the entry timing to the pressing means of the tip of the surface-printed sheet was configured to a predetermined amount delayed from the duplex continuous printing.

  According to a second aspect of the present invention, there is provided a plate cylinder on which a plate-making master for double-sided printing, in which two first and second plate-making images are formed side by side along the rotation direction of the plate cylinder, and the plate A printing unit having a pressing means that is relatively movable toward and away from the cylinder, and a printing image is formed on the surface of the printing unit corresponding to one of the first plate-making image and the second plate-making image. A paper re-feeding unit that temporarily holds the front-side printed paper and then re-feeds the paper toward the printing unit; and a front end of the front-side printed paper disposed in the re-feeding unit near the printing unit. A first image corresponding to the first plate-making image in the plate-making master on the plate cylinder, and a paper holding means for holding the front-side printed paper in the second position A first printing pressure range pattern for applying printing pressure only to the region, in the master plate-making master on the plate cylinder A second printing pressure range pattern for applying printing pressure only to the second image area corresponding to the second plate-making image, and a third for applying printing pressure to the second image area continuously from the first image area. A printing pressure range variable means capable of selectively switching one of at least three printing pressure range patterns of the printing pressure range pattern, and the surface printed after being re-fed from the re-feeding unit In a double-sided printing apparatus that forms a print image corresponding to the other of the first plate-making image and the second plate-making image on the back surface of the paper, the pressing means that drives the pressing means at substantially the same peripheral speed as the plate cylinder A driving unit; a refeeding conveyance unit that is disposed in the refeeding unit and temporarily holds and conveys the surface-printed paper toward the pressing unit; and the refeeding unit disposed in the refeeding unit. Front-side printed paper that has been transported by the paper transport means The refeeding contact means for contacting the pressing means, and the pressure range changing means for switching to the second printing pressure range pattern so as to form a printed image only on the back surface of the printed sheet. When the means is operated, the printing pressure range variable means is used to determine the approach timing of the front end of the surface-printed paper by the refeed conveyance means between the pressing means and the refeed contact means. And a control unit that controls the refeed conveyance unit so as to be delayed by a predetermined amount as compared with the case of performing double-sided continuous printing by switching to a printing pressure range pattern of 3.

  According to a third aspect of the present invention, there is provided a plate cylinder on which a plate-making master for double-sided printing, in which two first and second plate-making images are formed side by side along the rotation direction of the plate cylinder, and the plate A printing unit having a pressing means that is relatively movable toward and away from the cylinder, and a printing image is formed on the surface of the printing unit corresponding to one of the first plate-making image and the second plate-making image. A paper re-feeding unit that temporarily holds the front-side printed paper and then re-feeds the paper toward the printing unit; and a front end of the front-side printed paper disposed in the re-feeding unit near the printing unit. A first image corresponding to the first plate-making image in the plate-making master on the plate cylinder, and a paper holding means for holding the front-side printed paper in the second position A first printing pressure range pattern for applying printing pressure only to the region, in the master plate-making master on the plate cylinder A second printing pressure range pattern for applying printing pressure only to the second image area corresponding to the second plate-making image, and a third for applying printing pressure to the second image area continuously from the first image area. A printing pressure range variable means capable of selectively switching one of at least three printing pressure range patterns of the printing pressure range pattern, and the surface printed after being re-fed from the re-feeding unit In a double-sided printing apparatus that forms a print image corresponding to the other of the first plate-making image and the second plate-making image on the back surface of the paper, the pressing means that drives the pressing means at substantially the same peripheral speed as the plate cylinder A driving unit; a refeeding conveyance unit that is disposed in the refeeding unit and temporarily holds and conveys the surface-printed paper toward the pressing unit; and the refeeding unit disposed in the refeeding unit. The tip of the surface printed paper that has been transported by the paper feed transport means Re-feeding stop means for temporarily stopping the paper before being delivered to the pressing means, and the surface-printed paper that is disposed in the re-feeding section and conveyed by the re-feed conveying means to the pressing means. A re-feeding registration unit that is displaceable between a contact position to be contacted and a separation position that is separated from the contact position, and the printing pressure range variable unit to switch to the second printing pressure range pattern. When the pressing unit is operated to form a printed image only on the back side of the front surface printed paper, the front end of the front surface printed paper temporarily stopped by the refeed stop unit comes into contact with the pressing unit. Control means for controlling the re-feeding registration means so that the contact timing is delayed by a predetermined amount from the time when the printing pressure range variable means is switched to the third printing pressure range pattern to perform double-sided continuous printing. Having It is characterized by.

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. 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.
As described above, the present invention has been described with respect to specific embodiments including examples. However, the configuration of the present invention is not limited to the above-described embodiments, and may be configured by appropriately combining them. It will be apparent to those skilled in the art that various embodiments and examples can be made within the scope of the present invention according to the necessity and application thereof.

It is a partial cross section front view of the principal part of the double-sided stencil printing apparatus which shows the 1st 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. 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. (A) is a case where the surface-printed paper is conveyed by the rotation of the press roller while being pressed away from the outer periphery of the plate cylinder and is intermittently pressed against the plate cylinder 1 for printing (b) FIG. 10 is a simplified front view for explaining image position misalignment when a surface-printed sheet is sent out in a state where the press roller is in pressure contact with the plate cylinder. 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. 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. 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. FIG. 10 is an enlarged partial cross-sectional front view illustrating a double-sided printing operation in parallel with a printing unit of a double-sided stencil printing apparatus showing a second embodiment of the present invention, a configuration around a re-feeding unit, and a front-side printed paper transporting operation. It is a block diagram which shows the control structure of the principal part of the double-sided stencil printing apparatus in FIG.

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 The back surface plate-making image 8C as a 2nd plate-making image Intermediate intermediate plate-making area 8X As a plate-making master for double-sided printing Master plate 8YA with single plate making Image 11 Thermal head 15 as plate making means 15 Plate making section 16 Printing section 16a Nip section 17 Plate discharging section 18 Image reading section 19 Paper discharge section 20 Main motor 21 as plate cylinder driving means 21 Pressing means , Press roller 28 constituting re-feeding means printing pressure range changing means 30 paper feed section 33 paper feed roller 35 as paper feed means paper feed tray 36 as paper feed tray paper 36a surface printed paper 36b double-side printed paper 36c Single-side printed paper 45, 45A Refeeding means 46 Switching guide 47 as switching means As switching drive means Solenoids 48, 48A Re-feeding section 50 Roller guide plate 51 as a re-feeding guide member Re-feeding roller 52 as a re-feeding roller member Re-feeding sensor 54 as a surface printed paper detecting means As a pressing drive means Press roller rotation drive mechanism 65 Paper discharge sensor 81 as conveyance abnormality detection means Movement guide 86 as paper holding means Stop position detection sensor (position detection means)
87 Moving means 94 Drive motor (moving drive means)
98 Release cam 99 constituting operation timing control means Release pin 100, 100A Control devices 101, 101A as first and second control means CPU constituting first and second control means
102,102A ROM
104, 104A Refeed conveyance device 173 Operation panel 300, 300A 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 conveyance direction Y Paper width direction

Claims (7)

Relative to a plate cylinder on which a plate-making master for double-sided printing in which two first plate-making images and second plate-making images are formed side by side along the rotation direction of the plate cylinder, and the plate cylinder A printing unit having pressing means that can be freely contacted and separated, and a surface-printed paper having a printing image formed on the surface corresponding to one of the first plate-making image and the second plate-making image at the printing unit. A paper re-feeding unit that re-feeds the paper toward the printing unit after being temporarily held; and a front end of the front surface printed paper disposed in the paper re-feeding unit at a first position near the printing unit. And a movable paper holding means for holding and releasing the front end of the front surface printed paper at the second position, and the first surface is provided on the back surface of the front surface printed paper re-feeded from the refeed portion. A double-sided printing device that forms a print image corresponding to the other one of the second plate-making image and the second plate-making image. The duplex printing method for,
The double-sided printing is configured such that printing is resumed using the front-side printed paper held by the paper holding unit when a conveyance abnormality occurs during the formation of a printed image on the back side of the front-side printed paper. Printing method. The double-sided printing method according to claim 1,
The double-sided printing method, wherein when the conveyance abnormality occurs, the paper holding unit is used to stop the paper near the second position in a state where the front-side printed paper is held. The double-sided printing method according to claim 1 or 2,
The pressing means is driven at substantially the same peripheral speed as the plate cylinder. A double-sided printing method characterized in that the approach timing to the pressing means is delayed by a predetermined amount from the time of continuous double-sided printing. Relative to a plate cylinder on which a plate-making master for double-sided printing in which two first plate-making images and second plate-making images are formed side by side along the rotation direction of the plate cylinder, and the plate cylinder A printing unit having pressing means that can be freely contacted and separated, and a surface-printed paper having a printing image formed on the surface of the printing unit corresponding to one of the first plate-making image and the second plate-making image. A paper re-feeding unit that re-feeds the printing unit after temporarily holding the paper, and a front end of the front surface printed paper disposed in the paper re-feeding unit at a first position near the printing unit. A sheet holding unit that holds and releases a front end of the front surface printed sheet at a second position; and a moving unit that reciprocates the sheet holding unit between the first position and the second position. The first plate-making image and the second plate-making image are formed on the back surface of the front-side printed paper that has been re-feeded from the re-feeding unit. The duplex printing apparatus for forming a print image corresponding to the other of the images,
A conveyance abnormality detection means for detecting that a conveyance abnormality has occurred when forming a printed image on the back surface of the front-side printed paper;
Based on the signal from the conveyance abnormality detecting means, the moving means is controlled so that the paper holding means holds the surface printed paper and the paper holding means stops at a predetermined position. And a double-sided printing apparatus. The double-sided printing apparatus according to claim 4.
The predetermined position of the paper holding means is preset in the vicinity of a second position where the paper holding means holds the surface-printed paper,
Position detecting means for detecting that the sheet holding means occupies the vicinity of the second position;
The first control unit controls the moving unit so that the sheet holding unit stops near the second position based on signals from the conveyance abnormality detection unit and the position detection unit. Double-sided printing device. The double-sided printing apparatus according to claim 4 or 5,
A first printing pressure range pattern for applying a printing pressure only to a first image area corresponding to a first plate-making image on the plate-making master on the plate cylinder; a second plate-making on the plate-making master on the plate cylinder A second printing pressure range pattern for applying printing pressure only to the second image area corresponding to the image and a third printing pressure for applying printing pressure over the second image area from the first image area. A printing pressure range variable means capable of selectively switching one of at least three printing pressure range patterns of the range pattern;
Press driving means for driving the pressing means at substantially the same peripheral speed as the plate cylinder;
A re-feed conveyance unit that is disposed in the re-feed unit and temporarily holds the surface-printed paper and conveys the paper toward the pressing unit;
A refeeding contact means for contacting a surface-printed sheet disposed in the refeeding section and transported by the refeeding transporting means with the pressing means;
When the printing pressure range changing means is switched to the second printing pressure range pattern and the pressing means is operated to form a print image only on the back side of the front surface printed paper, the pressing means and the refeed Double-sided continuous printing is performed by switching the entry timing of the front end of the surface-printed paper by the refeed conveyance means to the contact means to the third printing pressure range pattern using the printing pressure range variable means. Second control means for controlling the refeed conveyance means so as to be delayed by a predetermined amount from the time;
A double-sided printing apparatus comprising: The double-sided printing apparatus according to claim 4 or 5,
A first printing pressure range pattern for applying a printing pressure only to a first image area corresponding to a first plate-making image on the plate-making master on the plate cylinder; a second plate-making on the plate-making master on the plate cylinder A second printing pressure range pattern for applying printing pressure only to the second image area corresponding to the image and a third printing pressure for applying printing pressure over the second image area from the first image area. A printing pressure range variable means capable of selectively switching one of at least three printing pressure range patterns of the range pattern;
Press driving means for driving the pressing means at substantially the same peripheral speed as the plate cylinder;
A re-feed conveyance unit that is disposed in the re-feed unit and temporarily holds the surface-printed paper and conveys the paper toward the pressing unit;
A refeed stop means for temporarily stopping the front end of the surface-printed paper disposed in the refeed section and transported by the refeed transport means before passing to the pressing means;
Displacement between a contact position where the surface-printed paper which is disposed in the refeed unit and conveyed by the refeed conveyance unit abuts on the pressing unit, and a separation position which is separated from the contact position Possible refeed resist means; and
When the printing pressure range changing means is switched to the second printing pressure range pattern and the pressing means is operated to form a print image only on the back side of the front surface printed paper, the refeed stop means temporarily When the double-sided continuous printing is performed by switching the contact timing at which the front end of the front surface printed paper stopped to the pressing means contacts the printing pressure range changing means to the third printing pressure range pattern. A second control means for controlling the re-feeding registration means so as to be delayed by a predetermined amount;
A double-sided printing apparatus comprising:

Images