JPH11348400A - Printing press - Google Patents

Abstract

PROBLEM TO BE SOLVED: To deliver a master to a master stop means while suppressing creasing of the master by enlarging the breadthwise direction of master by a specified amount after the forward end of the master is clamped before it is stopped at a stopping part. SOLUTION: A plate making means 30 carries a master 9 toward a plate cylinder 1 while plate making through a thermal head 11 and a platen roller 10 depending on image information and the plate cylinder 1 winds a master 9A completed of plate making around the outer circumference 1a thereof. A master clamping/carrying means 40 disposed between a tension imparting means 12 and a master stopping means 50 carries the master to the master stopping means 50 while clamping the forward end 9B thereof. A master clamping part passes through a stopping part Y opened at a master stopping position while clamping the forward end part 9B of the master 9 up to the front of a cutting means 20 and stops (clamps) the forward end part 9B at the stopping part Y. According to the arrangement, a master is delivered surely while suppressing creasing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus, such as a stencil printing apparatus, provided with a master holding and conveying means for conveying a master made on a plate to a master engaging means on a plate cylinder.

[0002]

2. Description of the Related Art A perforated master is wound around the outer peripheral surface of a plate cylinder which is driven to rotate by a driving source, ink is transmitted from the inside of the plate cylinder through a master perforated portion, and the ink is transferred to printing paper. 2. Description of the Related Art A stencil printing apparatus that obtains a print image by causing the stencil printing apparatus to be used is well known. In this stencil printing machine, master locking means for locking the leading end of the master on the outer peripheral surface of the plate cylinder is provided to be freely openable and closable with respect to the outer peripheral surface of the plate cylinder.
By opening and closing this master locking means at the master clamp position as needed, the leading end of the master conveyed by the platen roller, the conveyance roller or the like is held.

As a master used in stencil printing, a thin thermoplastic resin film (about 2 to 9 μm in thickness) and a paper made of Japanese paper, synthetic fiber or a mixture of Japanese paper and synthetic fiber as a porous support are attached. A laminate having a laminated structure is generally used, and a laminate having a thin porous support or a thermoplastic resin film alone without using a porous support is also available.

[0004] When transferring such a master to the master locking means, the following problems arise. First, since the thickness of the master is thin, the master wraps around a platen roller or a conveyance roller to which a conveyance force is applied by static electricity or curl before reaching the master locking means.

Second, even if the sheet is conveyed without being wound around each roller, a slight but undulating phenomenon occurs due to heat shrinkage at the time of perforation or a habit of the film.
If the master is locked by the master locking means and wound on the outer peripheral surface of the plate cylinder in the wavy state, the master may be wrinkled on the plate cylinder, resulting in poor printing. Such a state becomes conspicuous when a master having a weak stiffness is used, such as a thin porous support or a single thermoplastic resin film.

Thirdly, it is conceivable to provide a guide plate in the transfer path of the master to the master locking means to transfer the master. It is necessary to avoid contact with the means and the like, and the guide plate cannot be provided so close to the plate cylinder. Further, even when the guide plate is provided, if the master is charged with static electricity, a poor conveyance may occur in the case of the master having no rigidity.

Fourth, an antistatic agent may be applied to the surface of the master as a countermeasure for preventing the master from charging. However, the amount of the antistatic agent applied to the master having no rigidity is larger than that of the master having rigidity. This leads to corrosion of the thermal head and an increase in the cost of the master itself.

Although there is no technique for solving the first to fourth problems, for example, Japanese Patent Laid-Open Publication No.
Japanese Patent Application Laid-Open No. 937/937 and Japanese Patent Application Laid-Open No. 6-320853 disclose a technique in which the leading end of a master is pinched downstream of a cutting means using a master pinching and conveying means and is conveyed to a master locking means on a plate cylinder. JP-A-305232 proposes a technique in which a sheet member is superposed from the upstream side of the cutting means to the master locking means on the plate cylinder, and the leading end of the master is sent out.

[0009]

SUMMARY OF THE INVENTION The above-mentioned Japanese Patent Application Laid-Open No.
In the technology described in Japanese Patent Application Laid-Open No. 104937 and Japanese Patent Application Laid-Open No. 6-320853, since the master pinching / conveying means is disposed downstream of the cutting means, the leading end of the cut master is pinched and conveyed during the next plate making. When the sheet is conveyed to the transfer means, there is a possibility that the sheet is wrapped around the transfer roller, is clogged by the cutting means, or is caught on the introduction side of the master of the master holding and conveying means. When this happens,
It is difficult to transport the master in a stable state to the master locking means, and there is a problem in the transportability of the master.

In the technique described in Japanese Patent Application Laid-Open No. Hei 6-305232, since the leading end of the master overlaps the sheet member and is conveyed, the leading end of the master is moved before reaching the master locking means on the plate cylinder. The master may be turned up from the sheet member to cause wrinkles, and it is difficult to stably transport the master. In addition, if the master end is bonded or welded to the sheet member and conveyed, such a curl up can be prevented, but this requires a mechanism and process for bonding and welding, and also requires adhesion and welding. There is a possibility that wrinkles may occur at the time, and the sheet member and the leading end of the master may not be peeled off satisfactorily during delivery to the master locking means.

According to the present invention, the leading end of the master is securely clamped by the master clamping / transporting means, the leading end of the clamped master is stably transported to the master retaining means on the plate cylinder, and the master is retained by the master. It is an object of the present invention to provide a printing apparatus capable of reducing the occurrence of wrinkles on a master while reliably transferring the printing apparatus to a printing medium.

[0012]

According to the first aspect of the present invention,
A plate cylinder having a master locking means having a locking portion for locking the leading end of the master on a part of the outer peripheral surface; and making the master according to image information, and forming the master on the outer peripheral surface of the plate cylinder. In a printing apparatus having plate making means for transporting the master to be wound thereon and cutting means for cutting a plate made by the plate making means into a predetermined length, the plate cylinder is provided with A first position for holding the leading end of the master, which is located near the master locking means when stopped at the master locking position for locking the leading end and located on the upstream side of the cutting means in the master transport direction. And a master holding / conveying means capable of reciprocatingly displacing between a second position which can pass through the locking portion and lock the leading end of the master with the locking portion. After clamping the tip of the master at the first position, Serial locking portion is characterized in that the predetermined amount of expansion in the master width direction until engaging the distal end portion of the master.

According to a second aspect of the present invention, there is provided a plate cylinder provided with a master locking means having a locking portion for locking a leading end of a master on a part of an outer peripheral surface, and the master is made in accordance with image information. And a printing apparatus comprising: plate making means for conveying the master to be wound around the outer peripheral surface of the plate cylinder; and cutting means for cutting the plate-made master made by the plate making means into a predetermined length. In the vicinity of the master locking means when the plate cylinder is stopped at a master locking position for locking the leading end of the master with the locking portion, the printing cylinder is positioned upstream of the cutting means in the master transport direction. A master clamp capable of reciprocatingly displacing between a first position for clamping the leading end of the master and a second position where the leading end of the master passes through the locking portion and can be locked by the locking portion. Transport means, wherein the master nipping transport means is The contact portion between the tip portion, and having a elongate member to impart a stretching force to the master width direction with respect to the master.

According to a third aspect of the present invention, in the printing apparatus according to the second aspect, the extension member is further arranged so as to expand toward the downstream side in the master transport direction.

According to a fourth aspect of the present invention, there is provided a plate cylinder provided with an openable / closable master locking means having a locking portion for locking a leading end portion of a master on a part of an outer peripheral surface, and the plate cylinder according to image information. A printing apparatus comprising: a plate making means for making a master and transporting the master so as to wind the master around an outer peripheral surface of the plate cylinder; and a cutting means for cutting the plate made by the plate making means into a predetermined length. In the above, near the master locking means when the plate cylinder is stopped at a master locking position for locking the leading end of the master with the locking portion, the printing cylinder is positioned upstream of the cutting means in the master transport direction. Reciprocally displaceable between a first position where the front end of the master is sandwiched and a second position where the front end of the master passes through the locking portion and can be locked by the locking portion. Master holding and conveying means for holding the leading end of the master. When the master holding means moves from the open state to the closed state after the master holding / conveying means has moved to the second position in the state, the free end side tip of the locking portion abuts on the master. It is characterized by moving while moving.

According to a fifth aspect of the present invention, in the printing apparatus of the fourth aspect, the locking portion is formed in a shape in which a center portion of a free end side tip portion projects. .

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. The stencil printing machine shown in FIG. 1 includes a master roll 9R wound with a heat-sensitive stencilable master 9 (hereinafter, referred to as a master 9) mainly used for printing, stencil making means 30 for conveying the master 9 while making a stencil, A master holding means 40 for holding the master 9 toward a master locking means 50 provided on a part of the outer peripheral surface 1a of the plate cylinder 1;
And a tension applying means 12 for applying a tension to the master 9 moving toward the master locking means 50.

The master roll 9R is arranged at the most upstream in the master transport direction indicated by an arrow X (hereinafter, referred to as the master transport direction X), and the plate cylinder 1 is arranged at the most downstream in the master transport direction X. A master transport path is formed between the master roll 9R and the plate cylinder 1. Along the master transport path, the respective units are arranged in the order of the plate making means 30, the tension applying means 12, the master nipping and transporting means 40, and the cutting means 20. It is arranged in.

The master 9 is substantially made of only a very thin thermoplastic resin film such as polyester having a thickness of about 1 to 4 μm, and is wound around the outer peripheral surface of a core tube 9P made of a thermoplastic resin that is long in the axial direction. A roll 9R is formed. The master roll 9R is rotatably supported by a stationary member (not shown). The master 9 substantially consisting only of a thermoplastic resin film shown here means, in addition to the master consisting of only a thermoplastic resin film, a master containing a trace component such as an antistatic agent in a thermoplastic resin film, Include those in which one or more thin film layers such as an overcoat layer are formed on both principal surfaces of a thermoplastic resin film, that is, at least one of the front surface and the back surface.

The plate making means 30 conveys the master 9 toward the plate cylinder 1 while making a plate by the thermal head 11 and the platen roller 10 contacting the master 9 via the master 9 in accordance with image information. Platen roller 1
Numeral 0 is substantially integrally attached to the shaft 10a and is provided extending in the axial direction. The shaft 10a is rotatably supported by a side plate of a stencil printing machine (not shown). Is rotationally driven in the direction of the arrow in FIG. The thermal head 11 is located below the platen roller 10 and extends parallel to the shaft 10a.
The thermal head 11 is a heating element (not shown) based on digital image information processed and transmitted by an A / D conversion unit and a plate making control unit (both not shown) provided in a document reading unit of a stencil printing device (not shown). Has a well-known function of thermally perforating the master 9 by selectively generating heat.

The plate cylinder 1 includes a porous cylindrical support cylinder,
A mesh screen wound around the outer peripheral surface of the supporting cylindrical body, and the plate-making master 9A is wound around the outer peripheral surface 1a. The plate cylinder 1 is rotatably supported around an ink pipe 7 also serving as a rotation center axis, and is rotationally driven by a drive motor 22 as a drive source and a drive force transmission mechanism (not shown) in the direction of the arrow in the figure. Inside the plate cylinder 1, the plate cylinder 1
An ink roller 4 which rotates in the same direction in synchronism with the ink roller 4 and supplies ink to the inner peripheral surface of the plate cylinder 1; Roller 5 for forming an ink reservoir 6 and an ink pipe 7 for supplying ink to the ink reservoir 6
And an opening 7a provided at the bottom. These ink roller 4, doctor roller 5, and ink pipe 7 constitute ink supply means 60. A press roller 8 that swings up and down by a contact / separation mechanism (not shown) and presses the printing paper 73 against the plate cylinder 1 is disposed near the lower part of the outer peripheral surface 1 a facing the ink roller 4.

At a predetermined position (non-opening portion) on the outer peripheral surface 1a, there is provided a master locking means 50 for locking (clamping) the leading end 9B of the master 9A. The master locking means 50 extends parallel to the generatrix of the plate cylinder 1 and
a stage 2 provided substantially integrally with the
An openable and closable clamper 3 is rotated by receiving a driving force from an open / close device (not shown) via a clamper shaft 13, and a magnet 3 b for magnetically attaching the clamper 3 to the stage 2. The opening and closing device includes a step motor 23 serving as a clamper driving unit and a well-known driving force transmission mechanism.

As shown in FIG. 2, the clamper 3
Of the master 9
Is slightly longer than the width W of the plate cylinder 1 and shorter than the width L of the plate cylinder 1. The magnet 3b is located on the upstream side of the clamper shaft 13 in the master transport direction X.
Is fixed to the surface facing the stage 2 on the side of the open / close end 3a. Both side edges 3A and 3B of the clamper 3 located between the rear end 3c of the magnet 3b and the clamper shaft 13 and located in the width direction of the master 9 indicated by the double-headed arrow Z (hereinafter referred to as the master width direction Z). Are formed with notched portions 3L and 3R that are recessed inward of the clamper 3, respectively. The notches 3L and 3R are formed in a size that does not interfere with a pair of master holding portions 14 and 15 provided in the master holding and conveying means 40 described later. The range in which the clamper 3 is provided with the magnet 3b is a locking portion Y.

As shown in FIG. 1, the tension applying means 12
It is arranged between the plate making means 30 and the master holding means 40. The tension applying means 12 includes a pair of roller members 1.
2a and 12b are provided. Roller members 12a, 12
b are disposed so as to be opposed to each other with their outer peripheral surfaces in contact with each other. In this example, the master 9 has a function of changing the direction of the master 9 conveyed substantially horizontally to a substantially vertical downward direction. Follow each other. A brake device 12c such as a torque limiter is mounted on one end of one roller member 12b, and tension is applied to the master 9 moving in the master transport direction X so that no slack occurs in the moving direction. It is configured to give. The tension applying means 12 may be configured to rotate one of the roller members 12a and 12b with a drive motor. In this case, the peripheral speed of the outer peripheral surface of the driven roller member is set to the outer peripheral surface 1a. By setting the peripheral speed or the moving speed of the master holding and conveying means 40 to be lower, tension can be applied to the moving master 9.

The master holding / conveying means 40 is disposed between the tension applying means 12 and the master locking means 50, and holds the leading end 9B of the master 9 while holding the master holding means 50.
Is to be transported. As shown in FIG. 3, the master nipping and conveying means 40 includes a pair of master nipping parts 14 and 15 for nipping the front end 9B from both side edges 9a and 9b in the master width direction Z in the forward stroke. , 15 in the master width direction Z, as shown in FIG. 4, between the first position shown by the solid line and the second position shown by the two-dot chain line of the master holding portions 14, 15 as shown in FIG. And a moving means 17 for reciprocating with. The cutting means 20 is mounted on the master holding and conveying means 40 on the downstream side of the master holding sections 14 and 15 in the master conveying direction X.

Here, the first position refers to a position where the master holding portions 14 and 15 hold the leading end 9B of the master 9 conveyed before the cutting means 20, and the second position refers to the master position. In a state where the holding portions 14 and 15 hold the distal end portion 9B, they pass through the locking portion Y opened at the master locking position, and indicate positions where the locking portion Y can lock (hold) the distal end portion 9B.

As shown in FIGS. 3 and 5, the master holding portions 14 and 15 can be freely opened and closed so as to hold both side edges 9a and 9b of the front end portion 9B from both main surfaces (front and back surfaces) 9C and 9D. Upper transfer clampers 26A, 2 serving as holding members provided
6B and lower transport clampers 27A and 27B, electromagnetic solenoids 28A and 28B serving as clamping unit driving means for opening and closing the upper transport clampers 26A and 26B, and coil springs 29A and 29B as biasing means.

The lower transport clampers 27A and 27B are formed of plate-like members,
Are slidably supported in the master width direction Z. More specifically, slots 31A, 31B extending in the master width direction Z are formed in the lower transport clampers 27A, 27B, and the slots 141A, 31B are erected in parallel in the master width direction Z of the frame 141 in the slots 31A, 31B. Screw 32A, 32B and step screw 33A, 3
3B and 3B, respectively. Lower transport clamper 27A,
27B, one end side thereof is bent in a direction substantially orthogonal to the master width direction Z, and the lower end thereof is bent inward in the master width direction Z to form the contact portions 27C and 27D. The contact portions 27C and 27D are provided on the back surface 9D of the master 9.
Are arranged on the same plane so as to abut each other.

The upper transport clampers 26A and 26B are
The contact portions 27C and 27D are respectively provided by 4a and 34b.
It is supported to open and close freely. Electromagnetic solenoid 28A,
28B is attached to lower transport clampers 27A and 27B located above the upper transport clampers 26A and 26B, and the movable pieces 28C and 28D are attached to the upper transport clampers 26A and 26B.
A and 26B are pin-connected respectively. The electromagnetic solenoids 28A and 28B are of a push type that pushes out the movable pieces 28C and 28D when a drive signal is input. The coil springs 29A and 29B are
A, 28B and upper transport clampers 26A, 26B, both ends of which are locked.
B is given a turning behavior in the opening direction.

On the other end side of the lower transport clampers 27A, 27B, both side edges 9 of the front end 9B shown by reference numerals A, B in FIG.
a to move the master holding portions 14 and 15 in the master width direction Z between a holding position at which the master holding portions a and 9b can be held and a detached position deviated outward from the side edges 9a and 9b indicated by reference numerals C and D in FIG. A means driving mechanism 25 is provided. The separation positions C and D are located outside the both side edges 3A and 3B of the clamper 3.

As shown in FIGS. 3 and 5, the displacement means drive mechanism 25 includes a drive motor 35 that can be rotated forward and reverse as a drive source, a pinion gear 36 mounted on an output shaft 35a of the drive motor 35, It mainly comprises rack gears 37 and 38. The rack gears 37 and 38 are formed on the lower transport clampers 27A and 27B, respectively, and are provided at a pinion gear 36 disposed substantially at the center of the frame 141.
And mesh with each other from above and below. When the drive motor 35 is driven to rotate in the clockwise direction (positive direction) in FIG. 3, the displacement means drive mechanism 25 moves the lower transport clampers 27A and 27B in the direction indicated by the solid line arrow to separate the master holding portions 14 and 15. To the position,
When the drive motor 35 is driven to rotate counterclockwise (reverse) in FIG. 3, the lower transport clampers 27A, 27
B in the direction shown by the dashed arrow, and
4, 15 are displaced to the holding position.

In the vicinity of the long hole 31A of the lower transport clamper 27A, a holding position detecting sensor 41 and a separating position detecting sensor 42 as detecting means for detecting the holding position and the separating position are provided. A microswitch is used for each of the sandwiching position detection sensor 41 and the separation position detection sensor 42, and the separation position detection sensor 42
As shown in FIG. 5, when the lever 42a is pressed by the step screw 32B, a release position detection signal is output, and when the lever 41a is pressed by the step screw 32A, the pinch position detection sensor 41 outputs a pinch position detection signal. .

As shown in FIGS. 3, 4, and 5, the cutting means 20 is provided on the surface 141c of the frame 141 facing the master transport path such that the circular blade 43 serving as a cutting member faces the master transport path. It is installed. The cutting means 20 includes the facing surface 1
41c, a rotary having a rail 44 extending and fixed in the master width direction Z, a slider 45 slidably supported by the rail 44, and a circular blade portion 43 rotatably supported by the slider 45. It consists of a cutter and slides when the master is cut by a drive motor 39 described later.
The circular blade portion 43 is supported by the slider 45 such that the outer peripheral surface is located slightly below the contact surfaces 27C and 27D.

As shown in FIG. 4, the moving means 17 includes a rotating shaft 47 supported by the frame 141, and the rotating shaft 47.
And a drive motor 46 that can be rotated forward and backward as a drive source. The drive motor 46 is fixed to the frame 141 and its output shaft 4
A drive gear 49 is fixed to 6a. A driving gear 49 meshes with the gear 48, and the driving gear 49 of the gear 48
The rack 51 meshes with a position facing the meshing position with the rack. As shown in FIG. 3, the rotating shaft 47 is
Sides 141a, 141 provided upright on both sides of
The upper part b is rotatably supported by bearings 52, 52, and both ends thereof protrude outward from the side surfaces 141a, 141b. A pair of guide pins 53 is provided below the side surfaces 141a and 141b so as to protrude in the master width direction Z.

Both ends of the rotating shaft 47 and the guide pins 53, 53
As shown in FIG. 4, is loosely fitted into long holes 54 and 55 formed in a frame of a device (not shown). The elongated holes 54 and 55 are formed so as to extend from the tension applying means 12 toward the master engaging means 50 at the master engaging position shown in FIG. To the downstream of the locking portion Y of the master locking means 50, that is, from the first position to the second position. As a result, the master holding / conveying means 40 is configured to be guided to the master locking means 50 and not to swing during the reciprocating operation.

The master locking position here refers to a position where the plate cylinder 1 stops when the master 9 is locked by the master locking means 50. In this embodiment, the clamper 3 is moved upward in FIG. It refers to a position where the master locking means 50, which opens and closes in a facing state, is placed almost right beside.

The drive motor 46 is moved from the first position to the second
4 is rotated clockwise (positive direction) in FIG. 4 at the time of forward movement to move the master holding / conveying means 40 to the position shown in FIG. 4, and at the time of double movement of moving the master holding / conveying means 40 from the second position to the first position. In FIG. 4, it is rotationally driven in a counterclockwise direction (reverse direction).

In the vicinity of the master nipping and conveying means 40, a first position detecting sensor 56 for detecting that the master nipping and conveying means 40 has been positioned at the first position, and for detecting that it has been positioned at the second position. Second position detection sensor 5
7 are arranged. The first position detection sensor 56 outputs a first position detection signal by being pushed by a part of the frame 141 when the master holding and conveying means 40 occupies the first position, and the second position detection sensor 57 When the nipping and conveying means 40 occupies the second position, the frame 141
And a limit switch that outputs a second position detection signal when pressed by a part of the switch. The master holding / transporting means 40 sets the home position when the master holding portions 14 and 15 are at the holding position A.

In this embodiment, the master nipping and conveying means 4
0 is configured to be able to reciprocate substantially vertically. The rack 51 is arranged in parallel with the long hole 54 and is fixed to a frame (not shown). For this reason, when the drive motor 46 is not driven, the master pinching / conveying means 40 is held at a fixed position by meshing the drive gear 49, the gear 48 and the rack 51. In other words, the rack 51, together with the gear 48, constitutes a drop prevention (stopper) means and a positioning means of the master nipping and conveying means 40.

The stencil printing apparatus includes a control unit 70 shown in FIG.
It has. The control means 70 is composed of a well-known microcomputer having a ROM and a RAM.
It functions as a drive circuit and controller for each means. The control means 70 includes a stop key 61 serving as a stop command means, a plate making start key 62 serving as a plate making command means, a print start key 63 serving as a print command means, a first position detecting sensor 56, a second position detecting sensor 57, Position detection sensor 41, separation position detection sensor 42, step motors 21, 23, various drive motors 22, 35, 3
9, 46, electromagnetic solenoids 28A and 28B and power supply 58
Are electrically connected to each other.

When the master making start key 62 is depressed and a master making command is output, the control means 70 controls the master making master 9.
A is transported to the clamper 3 on the plate cylinder 1 using the master holding and transporting means 40, and a function of performing a plate making operation of winding the master 9A having the plate made on the outer peripheral surface 1a is performed, and the print start key 63 is depressed. When a print command is output, a function of performing a well-known printing operation for executing printing of the number of prints set by a ten-key (not shown), a function of stopping a plate making operation or a printing operation when a stop key 61 is pressed, And a control unit 71 for controlling the drive motor 39.

Hereinafter, the plate making function by the control means 70 and the operation of the apparatus by the control unit 71 will be mainly described. In FIG. 1, when a new master roll 9R is set in the apparatus, the master roll 9R is unwound and the platen roller 1R is unrolled.
The master 9 is inserted between the thermal head 11 and the thermal head 11, and the master 9 is interposed between the roller members 12a and 12b so that the leading end 9B is positioned up to the master nipping and conveying means 40.

When the plate making start key 62 is depressed, the drive motor 22 is driven by a predetermined amount, and a printed master (not shown), which has finished printing by a well-known plate discharging means, is placed on the outer peripheral surface 1.
a, and the plate cylinder 1 stops at the master locking position.
When the plate cylinder 1 occupies the master locking position, the step motor 23 is driven and the clamper 3 is opened at the master locking position. When the first position detection signal is output from the first position detection sensor 56, it is determined that the master holding / conveying means 40 is at the home position, and the electromagnetic solenoids 28A,
28B is driven. As a result of this driving operation, the upper transport clampers 26A, 26B are closed, and both side edges 9a, 9b of the front end portion 9B of the master 9 are moved from both main surfaces (front and back surfaces) 9C, 9D as shown in FIG. It is sandwiched between 14 and 15. That is, as shown in FIGS. 6A and 6B, the clamper 3 is in the open state, and both side edges 9a and 9b of the front end 9B of the master 9 are in the first position at the master holding portion 14. , 15.

When the electromagnetic solenoids 28A and 28B are turned on, the drive motor 35 is energized for a predetermined time (several msec), and the drive motor 35 rotates clockwise in FIG. As a result, the pinion gear 36 is rotated clockwise by a small amount, and the lower transport clampers 27A and 27B having the racks 37 and 38 meshing therewith.
Move relative to the solid line position from the two-dot chain line position. The relative movement amount of the lower transport clampers 27A and 27B is
To the extent that the master 9 does not fall out of the master holding portions 14 and 15,
In addition, it is set to such an extent that the master 9 does not expand.

With this movement, the master holding portion 14 and the master holding portion 14 are held in a state where the side edges 9a and 9b of the leading end 9B of the master 9 are held.
Since 15 spreads in the master width direction Z, the slack at the leading end 9B of the master 9 is extended.

When the electromagnetic solenoids 28A and 28B are driven and the energization of the drive motor 35 is completed, the step motor 21 is started, the platen roller 10 is driven to rotate clockwise and the master 9 is sent out, and at the same time, the image is displayed. The heating element of the thermal head 11 is selectively heated according to the information, and the master 9 pressed by the platen roller 10 against the thermal head 11 is selectively melted and perforated. The perforated master 9A thus perforated is transported in the master transport direction X by the platen roller 10.

On the other hand, the first position detection sensor 56
When the position detection signal is output, the drive motor 46 shown in FIG. 4 is driven to rotate clockwise, and the master nipping and conveying means 40 moves toward the second position (downward) in FIG. At this time, the moving speed of the master nipping and conveying means 40 is conveyed at substantially the same speed as the master conveying speed by the platen roller 10. In this way, the master-carrying master 9A is conveyed toward the clamper 3 while applying tension between the master-making master 9A and the roller members 12a and 12b by the forward movement of the master nipping and conveying means 40.

When the master nipping and conveying means 40 occupies the second position after passing between the expanding stage 2 and the clamper 3, a second position detection signal is output from the second position detection sensor 57. , The drive motor 46 is stopped. As a result, as shown in FIGS. 7A and 7B, the master holding portions 14 and 15 pass through the locking portion Y and have the notches 3L and 3L.
It stops at the holding position B in 3R. When the driving motor 46 stops, the stepping motor 23 is driven to rotate by a predetermined amount in the closing direction, and then the electromagnetic solenoids 28A, 28
B is not driven (off). As a result, the plate-making master 9 pinched and transported by the master pinching sections 14 and 15
After the leading end 9B of A is locked by the stage 2 and the magnet 3b of the clamper 3, the master holding portion 14,
15 is released. Therefore, even when the master 9 is charged with static electricity or curled, the master 9 is not wound around the roller members 12a and 12b, and can be reliably transported to the clamper 3.

When the electromagnetic solenoids 28A and 28B are turned off, the drive motor 35 is driven clockwise in FIG. 5, and is driven until the separation position detection sensor 42 outputs a separation position detection signal. As a result, the pinion gear 36 is driven to rotate clockwise, and the lower transport clampers 27A and 27A having the racks 37 and 38 meshing therewith.
27B relatively moves from the two-dot chain line position to the solid line position.

When the lever 42a of the separation position detecting sensor 42 is pushed by the step screw 32B and the separation position detection signal is output, the rotation of the drive motor 35 stops. Thus, the master holding portions 14 and 15 occupy the detached position C in the second position.

When the separation position detection signal is output from the separation position detection sensor 42, the drive motor 46 shown in FIG. 4 is driven to rotate counterclockwise, and this operation is performed by the first position detection sensor 56 The operation is performed until the detection signal is output. By this operation, the master holding / conveying means 40 placed at the second position shown by the two-dot chain line in FIG. 9 is moved back to the first position, and the master holding portions 14 and 15 are separated from the separation position D.
Is positioned. As described above, the master holding portions 14, 1
5 is moved from the second position to the first position while occupying the detached position when the master nipping and conveying means 40 moves backward, so that both side edges 9a and 9b and both side edges 3 are moved during the movement.
A and 3B do not interfere.

Since the stepping motor 21 is driven during the movement of the master holding and conveying means 40, that is, while the master holding portions 14 and 15 are moving between the separation positions C and D in FIG. The plate making conveyance of the roller 10 is performed. For this reason, the master 9 causes the master-making master 9A to be excessively fed between the platen roller 10 and the roller members 12a and 12b.

When the first position detection signal is output from the first position detection sensor 56, the drive motor 22 drives the plate cylinder 1 to rotate in the direction of the arrow in FIG. The plate 1 is wound around the outer peripheral surface 1a by the rotation of the plate 1.

When the master 9 is conveyed by a predetermined amount by rotating the step motor 21 by a predetermined amount, the outer peripheral surface 1a of the plate cylinder 1
The step motor 21 and the drive motor 22 are stopped assuming that the plate-making master 9A to be wound on the plate has been made. After the plate making operation is completed, the drive motor 35 is driven counterclockwise in FIG. 5 to rotate the pinion gear 36 counterclockwise, and the lower transport clampers 27A, 27B
Move relatively in the direction of the broken line. Then, when the lever 41a of the holding position detection sensor 41 is pressed by the step screw 32A and the holding position detection signal is output, the rotation of the drive motor 35 is stopped, whereby the master holding portions 14, 15 are held at the holding position A. Is done.

Accordingly, the control unit 71 drives (turns on) the electromagnetic solenoids 28A and 28B, closes the upper transport clampers 26A and 26B, clamps both side edges 9a and 9b, and holds the cutting state while maintaining the state. Drive motor 39
Drive. Thereby, the slider 45 is slid from right to left in FIG. 5, and the rear end of the master 9A is cut by the circular blade 43. For this reason, the plate-making master 9A has its tip 9B locked by the clamper 3,
Since the rear end portion on the upstream side in the master transport direction X is cut while being held by the master holding portions 14 and 15,
The master 9 can be cut satisfactorily, and it is not necessary to transport the leading end 9B of the master 9 to the master holding portions 14 and 15 after cutting. Therefore, even when the master 9 is charged or the curl remains on the master 9, the master 9 is moved between the master making means 30 and the master nipping and conveying means 40.
Is prevented from being clogged.

After the cutting, the electromagnetic solenoids 28A and 28B are turned off, the master holding portions 14 and 15 are opened, and the drive motor 22 rotates the plate cylinder 1 in the direction of the arrow in FIG. The master 9A is wound.

Thereafter, the control means 70 controls the drive motor 2
2 is driven to rotate the plate cylinder 1 at a low speed in the direction of the arrow in FIG. 1, and one print sheet 73 is fed from a not-shown sheet feeder to a well-known registration roller 72. At this time, the ink roller 4 is also rotated in the same direction as the rotation direction of the plate cylinder 1, and ink is supplied to the inner peripheral surface of the plate cylinder 1. The registration roller 72 feeds the printing paper 73 between the plate cylinder 1 and the press roller 8 at a predetermined timing synchronized with the rotation of the plate cylinder 1. Then, the press roller 8 separated from the outer peripheral surface 1a moves from the separated position indicated by the solid line in FIG. 1 to the pressing position indicated by the two-dot chain line, and is wound around the outer peripheral surface 1a of the plate cylinder 1 driven to rotate in the direction of the arrow. The printing paper 73 is pressed against the plate-making master 9A. As a result, the stencil master 9A is brought into close contact with the outer peripheral surface 1a while the ink oozes from the perforated portion of the stencil master 9A, so that the so-called stencil printing is completed, the respective drive motors and the step motors are stopped, and a printing standby state is established. .

When the number of prints is set by a ten-key (not shown) and the print start key 63 is pressed, the plate cylinder 1 is pressed.
Is rotated at a high speed, and the press roller 8 and the registration roller 72 are driven in the same manner as printing, so that printing for the set number of sheets is performed on the printing paper 73.

As described above, in this embodiment, the transfer of the master 9 from the plate making means 30 to the master locking means 50 is performed in a state where the master 9 is held by the master holding portions 14 and 15, and thus the rotation of the roller member is performed. Unlike the extrusion conveyance of the master 9, the conveyance failure due to the sticking or curling of the master 9 due to the static electricity does not occur. Further, the master holding portions 14 and 15 are expanded in the master width direction Z in a state where the both side edges 9a and 9b of the front end portion 9B of the master 9 are held between the master holding portions 14 and 15 to reduce the slack of the front end portion 9B. As you stretch,
Since the tip 9B is clamped by the clamper 3 in a state where tension is applied by the roller pair 12a, 12b and the brake device 12c during the master conveyance, it is possible to prevent wrinkles and loosening of the plate-making master 9A during this clamping.

Further, since the cutting means 20 is arranged on the downstream side of the master holding and conveying means 40 in the master conveying direction X, and the cutting is performed while the side edges 9a and 9b are held by the master holding portions 14 and 15, After cutting the master 9A, the leading end 9B of the subsequent master 9 is already located on the contact portions 27C and 27D. There is no need to carry the master 9, and it is possible to prevent the clogging of the master 9 between the plate making means 30 and the master pinching / conveying means 40 and the occurrence of wrinkles caused thereby.

Further, the front end portion 9 is formed by the master holding portions 14 and 15.
Since the master 9 holding B is transported to the downstream side in the master transport direction X from the locking portion Y, the tip 9B can be reliably locked by the clamper 3.

FIGS. 9 and 10 show a second embodiment of the present invention. The second embodiment differs from the first embodiment in that the extension members 18 are provided on the contact surfaces of the upper transport clampers 26A, 26B with the contact portions 27C, 27D, which are the contact portions with the tip 9B of the master 9. , 19 only.

The stretching members 18 and 19, which are made of a thin plate of an elastic body having a substantially curvilinear shape, have one ends fixed to the open ends of the upper transport clampers 26A and 26B, and the other ends in the master width direction Z. It is arranged so that it faces outside. Examples of the stretching members 18 and 19 include a mylar, a metal sheet, a resin sheet, and a rubber sheet.

By providing the extension members 18 and 19, the tip 9B of the master 9 is extended outward in the master width direction Z when the upper transport clampers 26A and 26B are closed, and the slack of the tip 9B is reduced. Removed. It is desirable that the extension members 18 and 19 have a certain degree of frictional resistance, such as resin and rubber.

As a modification of the second embodiment, as shown in FIG. 11, an upper extension member 68 is used instead of the extension members 18 and 19.
A, 68B and lower extension members 69A, 69B may be used. The upper extension members 68A and 68B made of a rod-shaped elastic body are fixed to the upper transport clampers 26A and 26B, and the lower extension members 69A and 69B having inclined surfaces 69a and 69b.
Are fixed to the contact portions 27C and 27D. The lower extension members 69A and 69B are disposed in such a manner that the inclined surfaces 69a and 69b are lowered as going outward in the master width direction Z.

With this configuration, the upper transport clamper 26
When A and 26B are closed, the upper extension members 68A and 68B elastically deform along the inclined surfaces 69a and 69b, whereby the distal end portion 9B is extended outward in the master width direction Z, and the slack is removed. You. The upper extension members 68A, 68B
It is desirable to use a material having a certain degree of frictional resistance, such as resin or rubber, and the inclined surfaces 69a and 69b may be flat or curved.

As another modified example of the second embodiment,
As shown in FIG. 12, the extension members 18 and 19 may be disposed obliquely so that their free ends are directed outward in the master width direction Z as their free ends are directed downstream in the master transport direction X.
As another modification of the modification shown in FIG. 1, as shown in FIG. 13, the lower extension members 69A and 69B are
9b may be disposed obliquely so as to lower as it goes downstream in the master transport direction X and outward in the master width direction Z. With such a configuration, the leading end portion 9B is extended toward the downstream side in the master transport direction X and the outside in the master width direction Z, and the slack is removed.

FIG. 14 shows a stencil printing apparatus used in the third embodiment of the present invention. This stencil printing machine
Compared with the first embodiment, the point that the master locking unit 24 is used instead of the master locking unit 50 and the stop position of the plate cylinder 1 at the master locking position are different from those of the first embodiment. The only difference is that it occupies a position displaced slightly upward from the side.

The master locking means 24 includes a stage 59 extending in parallel with the generatrix of the plate cylinder 1 and provided substantially integrally with the outer peripheral surface 1a.
An openable and closable clamper 64 that is rotated by receiving a driving force from an opening / closing device (not shown) through the opening 5 is provided. The opening / closing device includes a step motor 23 and a well-known driving force transmission mechanism, as in the first embodiment.

The clamper 64 mainly includes a support portion 64a supported by the clamper shaft 65 so as to be openable and closable, and a locking portion 64Y rotatably connected to the support portion 64a by a pin 64b. The clamper 64 has its locking portion 64
The width of Y is formed to be the same as the total width E of the clamper 3, and the width of the support portion 64a is formed to be the width of the locking portion 64Y excluding the cutout portions 3L and 3R of the clamper 3.

A magnet 64c for magnetically attaching the clamper 64 to the stage 59 is attached to the locking portion 64Y. A torsion coil spring (not shown) for applying a rotational urging force in the counterclockwise direction in FIG. 14 to the locking portion 64Y is mounted on the pin 64b, and the pin 64b is connected between the support portion 64a and the locking portion 64Y. A stopper (not shown) is provided at the connection portion, and the locking portion 64Y occupies the position shown in the drawing when no load is applied, and occupies a position almost linear with the support portion 64a when the master is locked. The urging force of this not-shown torsion coil spring will be described later.

The operation of the stencil printing apparatus based on the above configuration will be described below. When the plate making start key 62 is depressed, the drive motor 22 is driven by a predetermined amount, the printed master (not shown) is peeled from the outer peripheral surface 1a, and the plate cylinder 1 is stopped at the master locking position shown in FIG. When the plate cylinder 1 occupies the master locking position, the step motor 23 is driven to position the clamper 64 at the open position shown by the two-dot chain line in FIG. When the first position detection signal is output from the first position detection sensor 56, the master holding and conveying means 40 is determined to be at the home position and the electromagnetic solenoid 2
8A and 28B are driven, and both side edges 9a and 9b are held by the master holding portions 14 and 15.

When the electromagnetic solenoids 28A and 28B are driven, the step motor 21 is started, the platen roller 10 is driven to rotate clockwise, the master 9 is sent out, and at the same time the thermal head 11 is driven, and the master 9 is driven. Is perforated plate making. Pre-plated master 9A
Is transported in the master transport direction X by the platen roller 10.

On the other hand, the first position detection sensor 56
When the position detection signal is output, the master nipping and conveying means 40
Moves downward at substantially the same speed as the master transport speed by the platen roller 10, and the master 9A
Is transported toward the clamper 64 while being tensioned between the roller members 12a and 12b.

When the master holding means 40 passes between the expanding stage 59 and the clamper 64 and occupies the second position, the second position detection sensor 57 outputs a second position detection signal. The drive motor 46 is stopped, and the master holding portions 14 and 15 move to the holding position B in the first embodiment.
Stop at the position corresponding to.

When the drive motor 46 stops, the step motor 23 is driven to rotate by a predetermined amount, and the clamper 64 is rotated in the closing direction. At the time of this rotation, as shown by the solid line in FIG. 14, the free end side tip of the magnet 64c comes into contact with the master 9A, and pulls out the master 9A from the tension applying means 12 while applying tension. At this time, the urging force of the not-shown torsion coil spring provided on the pin 64b is set to such a degree that the master 9A having finished making the master does not fall out of the master holding portions 14, 15.
The clamper 64 is rotated counterclockwise about the clamper shaft 65 while rotating the locking portion 64Y clockwise so that the support portion 64a and the locking portion 64Y gradually become linear. You. Then, the stage 59 and the magnet 6
After the leading end 9B of the master 9A has been locked by 4c, the electromagnetic solenoids 28A and 28B are turned off, and the holding of the master 9A by the master holding portions 14 and 15 is released. This makes it possible to apply tension in the master transport direction X to the plate-making master 9A, and to remove slack.

Thereafter, similarly to the first embodiment, after the master holding portions 14 and 15 are moved from the separation position C to the position corresponding to the separation position D, the operation of winding the master having been made on the outer peripheral surface 1a is started. Done.

In the third embodiment, the free end of the magnet 64c is brought into contact with the plate-making master 9A. However, the free end of the magnet 64c is positioned on the clamper shaft 65 side (that is, the magnet 64c). May be shortened), and the free-end-side tip of the locking portion 64Y may be brought into contact with the master 9A that has been made.

As a modification of the third embodiment, FIG.
5. As shown in FIG. 16, the free end of the magnet 64c or the locking portion 64Y that comes into contact with the plate-making master 9A may be formed so as to protrude from the center.
By adopting such a configuration, the pre-mastered master 9A
Is applied with tension also in the master width direction Z at the time of contact, and the slack can be effectively removed. In the examples shown in FIGS. 15 and 16, the magnet 64c and the corner on the free end side of the locking portion Y are chamfered into a curved shape so that the central portion protrudes. A master 9A having a shape for applying tension in the direction Z and having a prepress
However, the shape is not limited as long as the shape is not damaged.

In each of the above embodiments and modifications, the arrangement position of the master roll 9R and the master engagement position of the plate cylinder 1 are set so that the leading end 9B is transported from above with respect to the clamper 3. Although the master holding / transporting means 40 is reciprocated in the vertical direction, the present invention is not limited to this configuration. When the arrangement position of the master roll 9R and the master locking position of the plate cylinder 1 are set so that the leading end 9B is transported and inserted into the clamper 3 from the horizontal direction, the master nipping and transporting means 40 is reciprocated in the horizontal direction. Slot 5 to move
4 and 55 are provided horizontally, and the rotating shaft 47 is rotated to
4 may be configured to travel. In this case, the rack 51 need not be provided.

In each of the above embodiments and modifications, the leading end 9B is held between the master holding portions 14 and 15, and the master 9 is made by the plate making means 30 while the master making master 9A is held by the master holding and conveying means 40. However, the front end 9B is held by the master holding portions 14 and 15, and the master 9 is held by the master holding / transporting means 40 to the clamper 3 before plate making. May be conveyed, and the master 9 may be subjected to plate making after being locked by the clamper 3. However, since the length of one master plate 9A wound around the outer peripheral surface 1a is limited by the circumferential length of the outer peripheral surface 1a, the plate making area of the master 9A is reduced. Sometimes. Therefore, in this case, by reducing the reciprocating movement range of the master pinching / conveying means 40 and setting the master locking position of the plate cylinder 1 closer to the master pinching / conveying means 40, the unplated area in the master 9 is reduced. Then, the plate making area may be secured.

In each of the above embodiments and modifications, a master substantially consisting of only a thermoplastic resin film was used as the master 9, but the master is not limited to this, and may have a porous support or A thin master with a further reduced thickness of the porous support than the master may be used.

In each of the above embodiments and modifications, the leading end 9B is connected to the master holding section 1 of the master holding and conveying means 40.
After being clamped at 4, 15 by the cutting means 20, it is cut to a predetermined length. However, in the case of a relatively hard-to-charge master or in an environment of low-chargeability, there are almost no problems such as winding of the master. It is not necessary to cut the plate-making master 9A after the holding by the master holding portions 14 and 15.

In each of the above embodiments and modifications, the cutting means 2
0 is mounted on the frame 141, and the
The cutting means 20 is configured to move integrally with the reciprocating operation of the stencil printing machine. However, the present invention is not limited to this. 20 may be provided separately. In this case, the cutting unit 20 is arranged downstream of the master holding units 14 and 15 in the master transfer direction X when the master holding and conveying unit 40 occupies the first position. Also,
As the cutting means 20, a rotary cutter that slides the circular blade portion 43 is illustrated, but a type that rotates a movable blade with respect to a fixed blade, or a so-called guillotine type may be used.

[0085]

According to the first aspect of the present invention, after the master pinching / conveying means has pinched the front end of the master at the first position and before it locks the front end of the master at the locking portion. Since the master is expanded by a predetermined amount in the master width direction, the leading end of the master spreads in the master width direction, and the slack is removed.

According to the second aspect of the present invention, since the master pinching / conveying means has an extension member at a contact portion with the tip of the master, when the master pinching / transporting means pinches the tip of the master, The tip is extended outward in the master width direction, and its slack is removed.

According to the third aspect of the present invention, since the extension member is disposed so as to expand toward the downstream side in the master transport direction, the master holding and transporting means can hold the master when the leading end of the master is gripped. Is extended toward the downstream side in the master transport direction and the outer side in the master width direction, and the slack is removed.

According to the fourth aspect of the present invention, when the master is locked, the free end of the locking portion moves while abutting on the master, so that the master is extended downstream in the master transport direction. , The slack is removed.

According to the fifth aspect of the present invention, the locking portion is
Since the center of the free end side tip portion is formed to protrude, when the free end side tip portion of the locking portion moves while abutting on the master when the master is locked, the master is moved in the master transport direction. It is stretched downstream and outward in the master width direction, and its slack is removed.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a stencil printing apparatus used in a first or second embodiment of the present invention.

FIG. 2 is a plan view showing a first position and a second position of a master holding device used in each of the first to third embodiments of the present invention, and a holding position and a separating position of a master holding portion. is there.

FIG. 3 is a perspective view showing a configuration of a master nipping and conveying means used in each of the first to third embodiments of the present invention.

FIG. 4 is a diagram illustrating a configuration of a moving unit provided in the master nipping and conveying unit.

FIG. 5 is a front view showing the configuration and operation of a master holding unit and a displacement unit, a driving mechanism thereof, and a holding unit driving member.

6A is a plan view showing a holding position of a master holding portion at a first position, and FIG. 6B is a side view of FIG.

7A is a plan view showing a clamping position of a master clamping unit at a second position, and FIG. 7B is a side view of FIG.

FIG. 8 is a block diagram showing a configuration example of a control unit and a control unit used in each of the first to third embodiments of the present invention.

FIG. 9 is a partial front view of a master holding section illustrating an extension member used in a second embodiment of the present invention.

FIG. 10 is a plan view of an upper transport clamper illustrating an extension member used in a second embodiment of the present invention.

FIG. 11 is a partial front view of a master holding section illustrating an extension member used in a modification of the second embodiment of the present invention.

FIG. 12 is a plan view of an upper transport clamper for explaining another modification of the second embodiment of the present invention.

FIG. 13 is a plan view of an upper transport clamper for explaining still another modified example of the second embodiment of the present invention.

FIG. 14 is a schematic configuration diagram of a stencil printing apparatus used in a third embodiment of the present invention.

FIG. 15 is a plan view of a clamper used in a modification of the third embodiment of the present invention.

FIG. 16 is a plan view of a clamper used in another modification of the third embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 plate cylinder 1a outer peripheral surface 9 master 9A plate-making master 9B tip portion 18, 19 extension member 20 cutting means 24, 50 master locking means 30 plate making means 40 master pinching and conveying means 64Y, Y locking part X master conveying direction Z master Width direction

Claims (5)

[Claims] A plate cylinder provided with a master locking means having a locking portion for locking a leading end of the master on a part of an outer peripheral surface; and a plate making of the master according to image information. In a printing apparatus having a plate making means for conveying the plate master to be wound around an outer peripheral surface of the plate cylinder, and a cutting means for cutting a plate made by the plate making means into a predetermined length, the plate cylinder is provided with the locking When the part is stopped at a master locking position for locking the leading end of the master, the leading end of the master is pinched near the master locking means and upstream of the cutting means in the master transport direction. A first position, and a master holding / transporting means capable of reciprocatingly displacing between a first position passing through the locking portion and a second position capable of locking the leading end of the master at the locking portion, The master nipping and conveying means is provided at a first position at a tip end of the master. After clamping, the printing apparatus characterized in that said locking portion by a predetermined amount flared master width direction until engaging the distal end portion of the master. 2. A plate cylinder provided with a master locking means having a locking portion for locking a leading end portion of a master on a part of an outer peripheral surface; In a printing apparatus having a plate making means for conveying the plate master to be wound around an outer peripheral surface of the plate cylinder, and a cutting means for cutting a plate made by the plate making means into a predetermined length, the plate cylinder is provided with the locking When the part is stopped at a master locking position for locking the leading end of the master, the leading end of the master is pinched near the master locking means and upstream of the cutting means in the master transport direction. A first position, and a master holding / transporting means capable of reciprocatingly displacing between a first position passing through the locking portion and a second position capable of locking the leading end of the master at the locking portion, The master pinching and conveying means includes a contact portion with the tip of the master. Printing apparatus characterized by having an elongate member to impart a stretching force to the master width direction with respect to the master. 3. The printing apparatus according to claim 2, wherein the extension member is disposed so as to expand toward the downstream side in the master transport direction. 4. A plate cylinder provided with an openable and closable master locking means having a locking portion for locking a leading end portion of a master on a part of an outer peripheral surface; A printing apparatus comprising: plate making means for conveying a master to be wound around the outer peripheral surface of the plate cylinder; and cutting means for cutting the plate-made master made by the plate making means into a predetermined length. In the vicinity of the master locking means when stopped at a master locking position for locking the leading end of the master with the locking portion, the tip of the master positioned upstream of the cutting means in the master transport direction. A master holding / transporting means capable of reciprocatingly displacing between a first position for holding the portion and a second position which can pass through the locking portion and lock the leading end of the master with the locking portion. The master pinch is held in a state where the tip of the master is pinched. After the transport means has moved to the second position, when the master locking means moves from the open state to the closed state, the free end side distal end of the locking part moves while abutting on the master. Characteristic printing device. 5. A printing apparatus according to claim 4, wherein said locking portion is formed in a shape in which a central portion of a free end side tip portion protrudes.