JP3287888B2 - Plate making equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plate making apparatus, and more particularly to a structure for removing electricity from a printing base paper.

[0002]

2. Description of the Related Art In general, a stencil printing apparatus, which is one of the printing apparatuses, uses a printing base paper formed by laminating, for example, a Japanese paper as a support and a film-like thermoplastic resin thereon. The printing base paper is perforated in a plate making apparatus, and the perforated sheet is wound around a plate cylinder, and ink from an ink supply mechanism disposed inside the plate cylinder is transferred to printing paper through the perforation of the printing base paper to obtain a printed material. It has become. FIG. 3 shows an example of the above-described printing apparatus. This printing apparatus A includes, in particular, a plate cylinder B on which printing base paper is wound, and an ink supply mechanism C provided inside the plate cylinder. A plate making apparatus D is provided as a main part. A plate making apparatus D for perforating the printing base paper E includes a transport device D1 for feeding out the printing base paper E stored in a roll, a thermal head D2 for perforating processing, a platen roller D3, and a cutter D4. While the printing base paper E is pressed against the thermal head D2 by the platen roller D3, it is pierced by heating and scanning with the thermal head D2, and when the length of winding and moving on the plate cylinder B reaches a predetermined length. The cutting is performed by the cutter D4.

[0003] The printing paper E fed from the plate making apparatus D is clamped at its leading end by a clamp mechanism B1 provided on the plate cylinder B and moves with the rotation of the plate cylinder B. Wound on.

The above-mentioned transport device D1 is composed of a plurality of roller pairs arranged along the feeding direction of the printing base paper E (the direction of the arrow in the drawing), and is configured to hold and transfer the printing base paper E. .

[0005]

In such a printing apparatus, a printing base paper E fed from a plate making apparatus D includes a printing base paper including a platen roller constituting a nip portion facing a thermal head. Is transported by the frictional force of the rollers arranged along the feeding direction, so that static electricity is easily generated on the printing base paper and the rollers. Therefore, when charging occurs due to static electricity generated between the film-like thermoplastic resin of the printing base paper and the roller, the printing base paper is electrostatically attracted to the surfaces of the guide members and rollers arranged in the transport path, This causes a so-called jam or other conveyance failure, and the printing process must be interrupted.

Therefore, conventionally, a roller having a structure in which protrusions and grooves are formed on the surface of the roller to reduce the area for frictional clamping that causes static electricity is provided, or the roller is formed by a conductive member. In addition, it has been proposed to contact a static elimination brush (for example, JP-A-2-248282).

However, with respect to reducing the contact area with the printing base paper, since such a configuration cannot be adopted for the platen roller used to press the printing base paper against the thermal head, static electricity is removed. Cannot be performed completely. When the roller is made of a conductive material, not only the roller,
It is meaningless unless the bearing of this roller is also made conductive.
Furthermore, even if the static elimination brush is made to correspond to only one of the charged objects, if the other charged object in which the static electricity of the opposite polarity is generated by the electrostatic induction remains as it is, when one of the static electricity is removed, it is re-applied. As a result, it is charged, and as a result, complete neutralization cannot be performed.

In view of the above-mentioned problems in the conventional plate making apparatus, the present invention aims to efficiently remove static electricity of opposite polarities generated between members that are in contact with each other, and to convey defective sheets. It is an object of the present invention to provide a plate making apparatus capable of preventing the occurrence of occurrence.

[0009]

In order to achieve the above object, the invention according to claim 1 is characterized in that the printing base paper is heated while being pressed against a thermal head by a platen roller to perform the perforation processing of the printing base paper. Then, in the plate making apparatus having a configuration for transferring the printing base paper toward the plate cylinder, the static electricity of the printing base paper among the static electricity generated during the holding and conveying of the printing base paper is brought into contact with the printing base paper conveyance path by contact.
A first static elimination member for static elimination, and a charge to the printing base paper
Static electricity of the platen roller charged to the opposite polarity to static electricity
A second static elimination member for eliminating static electricity by contact with air, wherein the first static elimination member and the second static elimination member are electrically connected to each other.

[0010]

[0011]

[0012]

[0013]

According to the present invention, the relative friction between two members is reduced.
Charging due to static electricity of opposite polarity
That is, positive and negative charges are electrically connected to each other.
It is generated by an electrical short circuit using the conductive neutralizing member.
By eliminating the charges in such a manner as to cancel out the accumulated electric charges, all the static electricity generated between the printing base paper and the member on the side of nipping and conveying the printing base paper is removed.

[0014]

[0015]

[0016]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

FIG. 1 is a schematic view showing the structure of a main part of a plate making apparatus according to the present invention. In FIG. 1, a plate making apparatus 1 includes a master storage unit 3 for accommodating a printing base paper (hereinafter, referred to as a master for convenience) 2 in a roll shape, and a transfer direction of the master 2 fed from the master storage unit 3.
A perforation processing unit 4, a cutter 5, and a master guide unit 6 are arranged in this order from the upstream side (in the direction of the arrow in the drawing). The perforation processing unit 4 includes a thermal head 4A and a platen roller 4B that can be opposed to and contact with the master 2 therebetween.
When the master 2 is pressed against the thermal head 4A by the platen roller 4B, a nip portion of the master 2 is formed. The thermal head 4A is formed by arranging a heating element having a well-known structure in a main scanning direction orthogonal to the transfer direction of the master 2. The heating element at a position corresponding to an image signal generates heat, thereby forming a film-like thermoplastic resin of the master 2. Perforate the resin.

On the other hand, the guide portion 6 is disposed in front of the plate cylinder 7 in the transfer direction of the master 2 and opposes the first and second guide members 6A and 6B across the transfer path of the master 2.
It has. The guide members 6A and 6B are formed in a shape capable of guiding the master 2 in the tangential direction of the plate cylinder 7 by rotating the transfer direction of the master 2 along the curl direction of the master 2. An opening (not shown) for allowing the roller of the tension mechanism 7 to enter the transfer path of the master 2 is formed in the second guide member 6B facing the thermoplastic resin side. That is,
The tension mechanism 7 is provided on the back side of the second guide member 6B,
That is, it is disposed at a position facing the first guide member 6A with the second guide member 6B interposed therebetween, and includes a lever 7B rotatable about the support shaft 7A. At one end of the lever 7B, there is provided a roller 7C which can move forward and backward with respect to the opening of the second guide member 6B.
Is hooked to one end of a tension spring 7D. Lever 7B is tension spring 7D
In the drawing, the rotation behavior in the counterclockwise direction in the drawing is imparted, and the roller 2C enters the transfer path of the master 2 through the opening of the second guide member 6B to be clamped on the plate cylinder 8 side. Is pulled between the clamp position.

A projection is formed on the surface of the lever 7B facing the plate cylinder 8 at a position on the swinging end side from the center of rotation, and the projection is formed by a clamp mechanism provided on the plate cylinder 8. 9 is pressed when it is opened.
Therefore, when the projection is pressed when the clamp mechanism 9 of the plate cylinder 8 is released and the master 2 is set to the plate feeding or discharging state, the tension spring 7D
, The roller 7B can be retracted from the opening of the second guide member 6B and the traction of the master 2 can be released.

The above-mentioned plate cylinder 8 has a well-known structure including an ink supply mechanism used in this type of stencil printing apparatus. The master 2 can be wound on the master. Then, the rotation speed of the plate cylinder 8 is made slower than that of the platen roller 4B, whereby, before reaching the tip of the second guide member 6B in the transfer direction of the master 2 in the transfer direction of the master 2 in the illustrated embodiment. A deflection is caused at the position. This bending is set in order to secure the length of the master 2 wound around the plate cylinder 8 and perform cutting by the cutter 5. Further, the clamp mechanism 9 is provided with a not-shown locking piece on the rotating shaft for positioning the leading end position of the master 2. The master 2 can be clamped by rotating the rotary shaft together with the positioning of the tip.

Meanwhile, the transfer path of the platen roller 4B and the master 2 which has passed through the position of the platen roller 4B, in the illustrated embodiment, the rear position of the cutter 5, discharger
Materials 10 and 11 are provided. Static elimination members 10 and 11
Is a member which is a feature of the present embodiment, and is constituted by conductive brushes which can come into contact with the peripheral surface of the platen roller 4B and the surface of the master 2 during transfer, and these brushes cover the transfer path of the master 2 together. It is attached to the conductive casing 12 and is conductive. Of these static elimination members, the static elimination brush 10 provided opposite to the platen roller 4 </ b> B is used to eliminate one polarity, for example, a negative charge, and is disposed in the transfer path of the master 2. discharging brush 11 provided in the other
The polarity, in this example, is provided to eliminate the positive charge.

Next, the operation will be described.

In winding the master 2 made on the plate cylinder 8, the clamping mechanism 9 on the plate cylinder 8 faces the front ends of the first and second guide members 6 A, 6 B of the guide portion 6. The lever 7B of the tension mechanism 7, which is disposed at a position where the lever 7B is opened and the projection is pressed when the clamp mechanism 9 is released, rotates clockwise in FIG.
C is separated from the second guide member 6B. Therefore, the roller 7C of the tension mechanism 7 is set in a state of retracting from the transfer path of the master 2 and releasing the traction of the master 2. Then, the master 2 fed out from the master storage section 3 is formed with a hole while being pinched and conveyed by a nip portion composed of a thermal head 4A and a platen roller 4B in the hole processing section 4 and then passed through a guide section 6. It reaches the clamping mechanism 9 on the plate cylinder 8 side. The front end of the master 2 is positioned by the locking piece of the clamp mechanism 9 and rotates the rotating shaft, so that the master 2 is clamped when the clamp mechanism 9 is closed.

On the other hand, when the leading end of the master 2 is clamped by the clamp mechanism 9, the lever 7B of the tension mechanism 7 also moves the second guide member 6B toward the first guide member 6A by the bias of the tension spring 7D. The master 2 is pulled by being pressed by the roller 7 </ b> C of the tension mechanism 7.

By the way, the master 2 fed out from the master storage section 3 is charged by friction generated in a nip portion between the master 2 and the platen roller 4B. When positively charged, the platen roller 4B
This will induce a negative charge of the opposite polarity on the side. However, in the present embodiment, since both the master 2 and the platen roller 4B are brought into contact with the neutralizing brushes 10 and 11, which are the neutralizing members , respectively, and the neutralizing brushes are electrically connected to each other. A current flows so as to cancel the charge due to the difference in charge polarity, which not only prevents accumulation of static electricity but also removes positively charged static electricity.

According to the present embodiment, the charge is removed for any of the charged polarities due to the static electricity generated by the frictional pinching. Therefore, it is possible to prevent the recharging that occurs when a small amount of the static electricity remains. As a result, it is possible to completely prevent a transfer failure due to electrostatic attraction of the master during the transfer. The static elimination member is not necessarily
It is not necessary to contact the opposing member. For example, it is possible to oppose the member with a gap in which the discharge can be performed. However, it is better to make the contact in order to prevent secondary adverse effects due to the discharge.

According to this embodiment having such a configuration, it is not necessary to provide a roller having a special structure such as reducing the contact area with the master 2 or providing conductivity as the transfer structure of the master 2. Cost increase can be prevented.

By the way, the present inventor determined the occurrence state of the jam with respect to the number and the arrangement position of the static elimination members of the above-described embodiment, and obtained the results shown in Table 1. In addition,
As a configuration for obtaining this result, as shown in FIG. 2, in addition to the configurations of the static elimination members 10 and 11 described in the above embodiment, for example, a third guide is provided on the distal end side of the first guide member 6A. The static elimination member 13 and the fourth static elimination member 14 are arranged on the distal end side of the second guide member 6B, respectively, and the third and fourth static elimination members 13 and 14 are both relative to the master 2. Although they are not in contact with each other, they are provided in the same state as when they are made conductive by being grounded to each other.

[0029]

[Table 1]

As is evident from the results, at least at a position where the master 2 can be brought into contact with the platen roller 4B in the transfer path and at the same time, the conduction of these static elimination members is caused by static electricity. It is necessary to perform the complete static elimination of the. This is because the generation of static electricity is most remarkable when the master 2 is conveyed by frictional clamping, and the amount of charge is large. It is effective to remove the static electricity at this point in order to prevent the master 2 from jamming after the perforation processing. It seems to be.

[0031]

[0032]

As described above, according to the present invention, the static electricity generated in the printing base paper as the master and the structure for frictionally holding and transporting the printing base paper during plate making is called an electrical short circuit.
Since the charge is eliminated by canceling the charge polarity, the situation where static electricity of one charge polarity remains is eliminated. Accordingly, since re-charging does not occur on the master that has passed through the discharging member , it is possible to prevent conveyance failure such as jam due to electrostatic attraction in the transfer path. In addition, both static elimination members 10 and 11 are electrically
Is electrically connected, the charge is transferred to the platen roller, base paper,
Both static elimination members, and conductive member for conducting both static elimination members
(Conductive housing)
Regardless of whether the device is grounded to earth
is there. That is, each static elimination member is individually grounded.
Not connected.
There is no risk of trouble.

[0033]

[0034]

[Brief description of the drawings]

FIG. 1 is a schematic view showing a configuration of a main part of a plate making apparatus according to the present invention.

FIG. 2 is a schematic diagram showing a partially modified example of the configuration shown in FIG.

FIG. 3 is a schematic view showing a conventional example of a printing apparatus provided with a plate making apparatus .
FIG .

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Plate-making apparatus 2 Master which is printing base paper 6B Platen roller 10, 11 Static elimination brush which forms a static elimination member

Claims (1)

(57) [Claims] 1. A plate making apparatus having a configuration in which a printing base paper is heated while being pressed against a thermal head by a platen roller to perform a perforating process of the printing base paper and transfer the printing base paper toward a plate cylinder. In the transport path of the printing base paper, the static electricity of the printing base paper out of the static electricity generated during the nipping and transporting of the printing base paper is removed by contact.
A first static elimination member for charging, and an electrostatic charge for the printing base paper
Static electricity of the platen roller charged to the opposite polarity
A second static elimination member for eliminating static electricity by contact, wherein the first static elimination member and the second static elimination member are electrically connected to each other;
A plate making apparatus characterized by being electrically conductive.