JPH09207422A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow choosing one from two printing methods, a combination of a printing plate processer and an electrostatic printer and use of an electrophotographic type image forming device, in a single apparatus, by a method wherein a printer includes a printing drum on which an original plate sheet is wound to produce an electrostatic printing plate. SOLUTION: A sheet of printing paper 7 is fed to a plate cylinder 1 by a paper feed roller 11 and held by the plate cylinder 1, and a photosensitive drum 27 of a plate processing/printing section 25 is negatively charged by a charger 29. Image data read by a scanner 23 are exposed on the photosensitive drum 27 by a laser head 31. An electrostatic latent image is formed as negative charges on exposed areas are neutralized, and then turned to a patent image by a developing device 35. When the printing paper 7 held by the plate cylinder 1 comes to the position of the photosensitive drum 27, a toner image is transferred on the printing paper 7, which is charged in reverse polarity to the electric potential of toner 33, by the action of a switch 53.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus for printing a desired image on a printing paper, and more particularly, to supply an original sheet to a printing cylinder to prepare an electrostatic printing plate, The present invention relates to a device that is devised so that electrostatic printing can be performed using the plate.

[0002]

2. Description of the Related Art There is already known a method of forming an image such as character information on an original sheet by an electrophotographic method, using the image as a plate for electrostatic printing, and performing electrostatic printing using the plate. ing. It will be described in detail with reference to FIGS. 2 to 7. First, there is an original sheet 102 as shown in FIG.
This original sheet 102 has an insulating layer 103 and a conductive layer 1 in advance.
05. Specifically, for example, it is provided as a film having a polyester resin film as a substrate and a surface thereof coated with a conductive polymer. Next, as shown in FIG. 3, an image (plate-making image) with toner is developed on the conductive layer 105 of the original sheet 102, and the image is fixed to form an insulating pattern layer 107, thereby completing the plate 101.

Next, as shown in FIG. 4, the charging device 109
Is prepared, and the plate 101 is uniformly charged so that the insulating pattern layer 107 remains charged. Then, as shown in FIG. 5, a developing device 111 is prepared. Liquid toner 115 as a developer charged to the opposite polarity is attached to the developing roller 113 of the developing device 111, and the liquid toner 115 is used for development. That is, the liquid toner 115 is attached to the insulating pattern layer 107 side of the plate 101. Next, as shown in FIG. 6, the printing paper 117 is placed on the plate 101 and the transfer / fixing roller 119 presses the printing paper 117 to the plate 101 side. As a result, the liquid toner 115 adhering to the insulating pattern layer 107 side is transferred and fixed on the printing paper 117 side, and the state shown in FIG. 7 is obtained.

Printing on one sheet of printing paper 117 is completed as described above, and thereafter, by repeating the steps of FIGS. 4 to 6,
The plate 101 is used to perform electrostatic printing on a desired number of printing sheets 117.

By the way, in the case of the electrostatic printing method,
When printing on a large number of printing papers 117, there is no problem, but when the number of printings is small, the original plate price (the price of the plate 101) is passed on to the printing price of one printing paper 117. There is a problem that the cost will rise.
Therefore, when the number of prints is small, an image forming apparatus adopting the electrophotographic method is used. That is,
Depending on the number of printed sheets, it is possible to select whether to perform printing by using a combination of a plate-making device and an electrostatic printing device or to use an image forming apparatus that employs an electrophotographic method.

[0006]

According to the above-mentioned conventional configuration, there are the following problems. That is, in the conventional case, as described above, depending on the number of printed sheets, printing is performed by a combination of the plate making device and the electrostatic printing device,
Or, it was selected whether to use an image forming apparatus adopting an electrophotographic method, but since each apparatus is separate, if all of these apparatuses are not provided, such an optional There was a problem that it could not be printed properly.
In addition, a plate is made by a plate making device, and the plate is carried to an electrostatic printing device to be set and printed, and the plate may be damaged due to such movement of the plate, or may be displaced at the time of setting. However, there is also a problem in that the print quality is deteriorated. Although it is considered that the above-mentioned functions can be realized by a single device, all of them are simply a combination of a plate-making device, an electrostatic printing device, and an image forming device adopting an electrophotographic method. However, there is a problem in that it is large and costly as a single device. Further, even in such a single device, the printing paper or plate must be transported between the devices, which may damage them, so that the quality of the printing is deteriorated in the end. There was a problem.

The present invention has been made on the basis of the above points, and an object thereof is to provide a single device,
To provide a compact and inexpensive printing device that can be used by selecting whether to perform printing by a combination of a plate making device and an electrostatic printing device or to use an image forming device that employs an electrophotographic method. is there.

[0008]

In order to achieve the above object, a printing apparatus according to the present invention is characterized in that an original sheet is wound around a printing cylinder to produce an electrostatic printing plate. To do. Further, a plate cylinder, a paper feed means arranged at an outer peripheral position of the plate cylinder to supply a printing sheet to the plate cylinder, and an original sheet supply means arranged at an outer peripheral position of the plate cylinder to supply an original sheet to the plate cylinder. An insulating image forming means for forming an insulating image on a printing paper or an original sheet which is arranged at an outer peripheral position of the plate cylinder and is rotated and conveyed while being held by the plate cylinder,
Electrostatic printing for electrostatically printing a printing paper supplied to the plate cylinder from the paper feeding means using a plate which is arranged at the outer peripheral position of the plate cylinder and is formed by forming an insulating image on the original plate sheet. Means and are provided. At that time, it is possible to use an electrophotographic system as the insulating image forming means.

That is, in the case of the present invention, a printing cylinder is basically used to form a plate for electrostatic printing. In other words, a single cylinder is used for both printing and plate making. Specifically, a configuration as set forth in claim 2 can be considered. Then, for example, when the number of prints is small, printing is performed on the printing paper wound around the plate cylinder by the insulating image forming means without creating a plate for electrostatic printing. When the number of prints is large, an insulating image is formed by the insulating image forming means on the original sheet which is supplied from the original sheet supply device and is wound around the plate cylinder. And
Then, using the plate, electrostatic printing is performed by electrostatic printing means on the printing paper supplied from the paper feeding device and wound around the plate cylinder. As the insulating image forming means, there are various electrophotographic systems such as a laser system and a thermal system.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. First, there is a plate cylinder 1, and a sheet feeding device 3 and an original sheet feeding device 5 are arranged at the lower left of the plate cylinder 1 in FIG. The paper feeding device 3 stacks and holds a plurality of printing papers 7 in the stocker 9, and supplies the printing papers 7 from the uppermost printing paper 7 to the plate cylinder 1 side sequentially by a paper feeding roller 11. Further, the original plate supply device 5 is for stacking and holding a plurality of original plate sheets 10 in the stocker 15, and supplies them sequentially from the uppermost original plate sheet 10 to the plate cylinder 1 side by the plate supply roller 17. The original sheet 10 has the same structure as the original sheet 102 shown in FIG. 2, and is formed by providing a conductive layer on one surface side of the insulating layer.

Further, on the right side of the plate cylinder 1 in FIG.
9 and the plate discharge device 21 are arranged respectively. The printed printing paper 7 is discharged to the paper discharge device 19, and the plate 13 used for electrostatic printing is discharged to the plate discharge device 21.

At the upper position of the plate cylinder 1 in FIG. 1, a scanner device 23 and a plate making / printer printing section 25 are arranged. The scanner device 23 and the plate-making / printer printing unit 25 constitute an insulating image forming means. A photosensitive drum 27 is arranged in the plate making / printer printing section 25, and around the photosensitive drum 27,
A charging device 29, a laser head device 31, a developing device 35 for supplying toner 33, and a cleaning device 37 for cleaning the photosensitive drum 27 are arranged respectively. A plate fixing device 39 is arranged at a position facing the plate cylinder 1 side. The scanner device 23 inputs image data such as character information and outputs it to the plate making / printer printing unit 25.

Further, on the outer periphery of the plate cylinder 1, a charging device 41, a developing device 43, a transfer device 45, and a printing paper peeling device 4 are provided.
7, cleaning device 49, fixing device 51, switch 5
3, 55 are arranged respectively, and these charging devices 41,
The developing device 43, the transfer device 45, the printing paper peeling device 47, the cleaning device 49, the fixing device 51, the switches 53 and 55, etc. constitute an electrostatic printing means.
In addition, reference numerals 57 and 59 in FIG. 1 respectively denote transport rollers.

The operation will be described based on the above configuration. First, a case where printing is performed on a small number of copies 7 will be described. In this case, basically no plate for electrostatic printing is produced. First, one sheet of printing paper 7 is supplied to the plate cylinder 1 by the paper feeding roller 11 of the paper feeding device 3. The supplied one printing sheet 7 is held by the plate cylinder 1.
On the other hand, in the plate making / printer printing section 25, the photosensitive drum 27 is in a state of being “negatively” charged by the charging device 29. The image data read by the scanner device 23 is read by the laser head device 31.
The photosensitive drum 27 is exposed. Then, in the exposed portion, the "negative" charge is neutralized, and as a result, an electrostatic latent image is formed.

The electrostatic latent image is developed by the developing device 35.
The toner 33, which is negatively charged, is visualized. Further, since the toner 33 is made of epoxy resin or the like to which magnetic fine powder such as ferrite and a plastic material are added to have an insulating property, the toner 33 is exposed to the "negative" when the photosensitive drum 27 is exposed. It will adhere to the part. Since the plate cylinder 1 and the photosensitive drum 27 rotate at a predetermined timing, the printing paper 7 held by the plate cylinder 1
When the toner image comes to the position of the photosensitive drum 27, the operation of the switch 53 causes the toner image to be transferred to the side of the printing paper 7 which is charged with a polarity opposite to the potential of the toner 33. The transferred toner image is fused and fixed by the plate fixing device 39, whereby the image formation is completed.

The printing paper 7 is conveyed as it is to the position of the paper peeling device 47 by the rotation of the plate cylinder 1, and is peeled by the paper peeling device 47. The peeled printing paper 7 is discharged into the paper discharge device 19. This completes printing on one sheet of printing paper 7. After that,
By repeating the above steps, the predetermined number of printing sheets 7 are printed. When the printing operation is repeated, the photosensitive drum 27 is cleaned by the cleaning device 37, and then the photosensitive drum 27 is uniformly charged by the charging device 29.

Next, the case of printing on a large number of copies of the printing paper 7 will be described. In this case, basically, a plate for electrostatic printing is manufactured, and the plate is used for electrostatic printing.
In this case, the plate feeding roller 17 of the original sheet feeding device 5
Thus, one original sheet 10 is supplied to the plate cylinder 1. The supplied one original sheet 10 is held by the plate cylinder 1. On the other hand, in the plate making / printer printing section 25, the photosensitive drum 27 is in a state of being negatively charged by the charging device 29. The image data read by the scanner device 23 is exposed on the photosensitive drum 27 by the laser head device 31.
Then, in the exposed portion, the "negative" charge is neutralized,
As a result, an electrostatic latent image is formed.

The electrostatic latent image is developed by the developing device 35.
The toner 33, which is negatively charged, is visualized. Further, since the toner 33 is made of epoxy resin or the like to which magnetic fine powder such as ferrite and a plastic material are added to have an insulating property, the toner 33 is exposed to the "negative" when the photosensitive drum 27 is exposed. It will adhere to the part. Since the plate cylinder 1 and the photosensitive drum 27 rotate at a predetermined timing, when the original sheet 10 held by the plate cylinder 1 reaches the position of the photosensitive drum 27, the switch 53 is operated to cause the potential of the toner 33. Thus, the toner image is transferred to the original sheet 10 side charged with the opposite polarity. The transferred toner image is melted and fixed by the plate fixing device 39, whereby the image formation is completed, and at the same time, the plate 13 for electrostatic printing is created.

Next, electrostatic printing is performed using the plate 13. First, the plate 13 held on the plate cylinder 1 is uniformly charged by the charging device 41 in a “positive” manner. By this "positive" charging, the conductive layer of the plate 13 becomes substantially ground potential. On the other hand, the insulating image portion of the plate 13 is 200 to 30
The electric charge of 0V is retained. Next, the developing device 43
, The negatively charged liquid toner is applied to the plate 13
Contact surface. As a result, the liquid toner is applied to the plate 1.
It is sucked to the 3 side and developed.

Next, the printing paper 7 is supplied to the plate cylinder 1 side by the paper feeding device 3, and both the printing paper 7 and the plate 13 come to the position of the transfer device 45. Therefore, the transfer device 45
However, when the “positive” potential is applied by the operation of the switch 55, the “negative” charged liquid toner on the toner image on the plate 13 is transferred to the printing paper 7 side. After that, the toner transferred by passing through the fixing device 51 is fixed and discharged to the paper discharging device 19 side. By repeating the same operation, desired printing is performed on the printing paper 7 having a large number of copies. In that case, the plate 13 is cleaned by the cleaning device 49, and then the charging device 4 is used.
1 means that it is uniformly charged. When the plate 13 is no longer needed after printing a predetermined number of sheets, the plate 13 is discharged into the plate discharging device 21.

According to this embodiment, the following effects can be obtained. First, according to the printing device of the present embodiment, a single device is used to repeatedly print by the insulating image forming means or to produce a plate for electrostatic printing, depending on the number of copies to be printed. It is possible to select whether or not to perform electrostatic printing by the electrostatic printing means using, so that it is possible to print without using a plurality of devices that are individually configured as in the past. It is possible to perform desired printing according to the number of copies. Also, in terms of configuration,
Since one plate cylinder 1 is configured to exhibit a desired function, it is compact and the cost of the device is low. In the case of performing electrostatic printing, the prepared plate 13 is wound around the plate cylinder 1 as it is, and electrostatic printing is performed without moving the plate 13 as it is. The quality of electrostatic printing can be improved in the end without damaging it or shifting its position due to inadvertent movement. Further, in the developing device 43 of the printing apparatus, a liquid toner is used, and the liquid toner is configured as a developing solution in which a toner holding a charge is suspended in an insulating liquid. . By using such a liquid toner, it has become possible to perform sharper printing with higher density.

The present invention is not limited to the above embodiment. First, in the plate making / printer section 25 of the printing apparatus, the one using the laser head device 31 is shown as an example of the electrophotographic system, but the invention is not limited to this, and all known electrophotography such as the LED system. Insulating image forming means including methods can be applied. Further, the developing device 43 of the printing device is not limited to liquid toner, but may be development using dry toner, charging mist or the like. Further, the image data is not limited to being input by the scanner, but may be input from a computer or the like. The configuration of the printing apparatus is shown in FIG.
It is not limited to those shown in.

Further, in the above-mentioned embodiment, a special sheet having a conductive layer formed on the surface in advance was used as the original sheet, but the original sheet is not necessarily limited to this. For example, it is conceivable to form a plate by a method of impregnating plain paper with a conductive agent. That is, a general plain paper is used as the printing paper, the printing paper fed from the paper feeding device is supplied to the plate cylinder and wound, and an insulating image by an electrophotographic method is once formed on the printing paper. A plate for electrostatic printing can be obtained by impregnating a conductive agent with a means such as a transfer roller or a spray to impart conductivity. The present invention can be applied to a plate produced by such a method. Since the above-mentioned conductivity is only required to be diffused when the plate is charged so as to cause an appropriate difference from the charged potential on the insulating image, a substance used as a conductive agent and used as a commercially available antistatic (eliminating) agent. Can be applied.

[0024]

As described above in detail, according to the plate making method and the plate making apparatus of the present invention, the original plate sheet is supplied and wound around the printing cylinder to form the plate for electrostatic printing. Therefore, both printing and plate making can be performed by a single device, and a compact device can be provided.
Further, in the case of the constitution as claimed in claim 2, the insulating image forming means repeatedly prints by a single device, or the plate for electrostatic printing is manufactured, depending on the number of print copies. It is possible to select and execute whether to perform electrostatic printing by the electrostatic printing means using it, so even if a plurality of devices that are separately configured are not provided, unlike the conventional case, It is possible to perform desired printing according to the number of print copies. Further, in the case of performing electrostatic printing, since the prepared plate is wound around the plate cylinder as it is, the electrostatic printing means performs electrostatic printing without moving the plate as it is. There is no damage or displacement of the plate due to careless movement of the plate.
The quality of electrostatic printing can be improved.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the invention and is a diagram showing a configuration of a printing apparatus.

FIG. 2 is a diagram showing a method of electrostatic printing step by step, showing a configuration of an original sheet.

FIG. 3 is a diagram showing electrostatic printing methods in order, showing a state in which an insulating image is formed on an original sheet.

FIG. 4 is a diagram sequentially showing a method of electrostatic printing, showing a state in which an insulating image of a plate is charged.

5A to 5C are diagrams showing electrostatic printing methods in sequence, showing how toner is attached to an insulating image on a plate to develop the image.

FIGS. 6A to 6C are diagrams sequentially showing an electrostatic printing method, showing a state in which toner on an insulating image on a plate is transferred to a printing paper side. FIG.

FIG. 7 is a diagram showing a method of electrostatic printing in order, showing a printed printing sheet.

[Explanation of symbols]

 1 Plate Cylinder 3 Paper Feeding Device 7 Printing Paper 5 Original Plate Feeding Device 10 Original Plate Sheet 11 Paper Feed Roller 13 Plate 17 Plate Feeding Roller 19 Paper Ejecting Device 21 Plate Ejecting Device 23 Scanner Device 25 Plate Making / Printer Section 27 Photosensitive Drum 29 Charging Device 31 Laser head device 33 Toner 35 Developing device 37 Cleaning device 39 Plate fixing device 41 Charging device 43 Developing device 45 Transfer device 47 Paper peeling device 49 Cleaning device 51 Fixing device 53 Switch 55 switch

Claims (3)

[Claims] 1. A printing apparatus, characterized in that an original sheet is wound around a printing cylinder to produce an electrostatic printing plate. 2. A plate cylinder, a paper feed unit arranged at an outer peripheral position of the plate cylinder for supplying a printing sheet to the plate cylinder, and an original sheet arranged at an outer peripheral position of the plate cylinder for supplying an original plate to the plate cylinder. A feeding means, an insulating image forming means for forming an insulating image on a printing paper or an original sheet which is arranged on an outer peripheral position of the plate cylinder and is rotated and conveyed while being held by the plate cylinder, and an outer peripheral position of the plate cylinder. An electrostatic printing means for performing electrostatic printing on the printing paper supplied from the paper feeding means to the plate cylinder by using an electrostatic printing plate which is arranged and formed by forming an insulating image on the original sheet; A printing apparatus comprising: 3. The printing apparatus according to claim 2, wherein the insulating image forming means is of an electrophotographic type.