JP2947516B2 - Web offset press - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an offset rotary printing press.
The present invention relates to improvement of the plate forming means.

[Conventional technology]

Conventional rotary offset printing presses wind a printing plate on which image information such as characters is printed and developed around the peripheral surface of a plate cylinder (roller), transfer the image information on the plate once to a blanket cylinder, The printing is performed by copying from the cylinder to printing paper.

[Problems to be Solved by the Invention] However, in the conventional offset rotary printing press, a printing plate operation of performing photographic printing on the printing plate is necessary, and this plate making operation requires time and cost, especially in small lot printing. There is a problem in that spending and, in turn, soaring the printing cost. In addition, in the conventional example, when the prepress plate is mounted on a roll, accurate positioning is required, and furthermore, a multicolor machine requires registration, and requires much labor and time. There is a point. In order to solve the fourth problem, a roll having a magnetic and hydrophobic surface is provided, a magnetic head for forming a magnetic latent image by magnetizing a surface corresponding to a non-image portion of the roll, and a hydrophilic head. An offset printing press provided with a toner supply device for supplying the processed magnetic toner to a non-image area where the roll is magnetized (Japanese Patent Laid-Open No. 62-22284)
7) is known, but with this printing machine, the magnetic force around the printing machine must be taken into account when making a plate, and the work involved in the plate making operation cannot be sufficiently reduced.

Here, an object of the present invention is to provide an offset rotary printing press capable of easily performing plate making operations, eliminating the need for plate mounting work, and performing printing quickly.

[Means for solving the problem]

In view of the above, the present invention is a non-printing version of an offset rotary printing press which allows direct input of image information such as characters to a roll on which a printing plate is conventionally mounted. Specifically, the present invention relates to a roll, a blanket cylinder, an impression cylinder, a coating device, a drying device, a charging device, an exposure device, an information input device, a toner developing device, a fixing device, a dissolution device, a fountain solution device, and an ink applying device. A meat device, wherein the roll has a surface of a hydrophilic powder material, the blanket cylinder is configured to be in rolling contact with a roll, and the impression cylinder has a paper to be printed interposed between the blanket cylinder and the blanket cylinder. The coating device is configured to coat a photoconductor liquid on a peripheral surface of the roll, and the drying device is configured to dry the coated photoconductor liquid. The charging device is configured to apply a coating layer of the photoconductor liquid to one of positive and negative by, for example, corona discharge or the like. The exposure device is configured to expose a predetermined position of the coating layer to form an image portion on the roll by, for example, a laser beam or the like, and the information input device is configured to be an exposure device. The toner developing device is configured to input a developing powder (toner) charged to the positive or negative side opposite to the coating layer to the charged coating layer. The fixing device is configured to fix the toner adhered by the toner developing device, The elution device is configured to remove a non-image portion of the coating layer, The fountain device is configured to supply water to the peripheral surface of the roll, and the ink filling device is configured to supply ink to the peripheral surface of the roll. It is those that have been.

[Action]

In the present invention having the above-described configuration, after image information is input to the roll to form an oleophilic image portion with toner, printing is performed by applying ink to the lipophilic image portion. . That is, first, by a coating device, the peripheral surface of the roller is coated with a photoconductor liquid, and after this coating layer is dried, positively or negatively charged, and then the image information input to the information input device is obtained. The coating layer is exposed and scanned by an exposure device. This allows
For example, when a non-image area is exposed, the potential of the exposed area is reduced and a latent image is formed. Thereafter, the lipophilic toner charged to the opposite sign to the charge charged to the coating layer by the toner developing device adheres to the unexposed portion, that is, the image portion, and the toner is fixed by the fixing device, and further eluted. The coating layer in the non-image area is removed by the apparatus. Thereby, a lipophilic image area where the toner image is fixed on the roll surface and a hydrophilic non-image area where the hydrophilic surface is exposed by the elution device are formed.

Next, when the dampening device and the ink filling device are operated, as in a normal offset rotary printing press, the ink is deposited on the lipophilic image portion, while the ink is deposited on the hydrophilic non-image portion. An ink image is formed by being repelled.
Furthermore, the roll and the blanket cylinder are rotated, and the ink image is transferred to a blanket image that is in contact with the roll,
Offset rotary printing is performed by supplying printing paper between the blanket cylinder and the impression cylinder. After the printing is completed, the roll surface is refreshed as necessary to prepare for the next printing.

〔Example〕

 Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

In FIG. 1 schematically showing the structure, a roll 1 is formed by a known technique using a grained metal surface such as aluminum, anodized, sodium silicate, potassium fluoride zirconate, polycarboxylic acid, or the like. It has been subjected to a hydrophilic treatment.

Around the roll 1, a coating device 5, a cleaning device 26, an elution device 19, a drying device 9, a charging device 1
0, an exposure device 11, a toner developing device 17, and a fixing device 18 are arranged along the roll rotation direction.

The coating apparatus 5 includes a roll coater 8 for uniformly applying the photoconductor liquid 7 stored in the pan 6 to the surface of the roll 1, and the roll coater 8 is retracted from the roll 1 when not in use. I have. Here, the photoconductor liquid 7 is made of poly-N-vinylcarbazole (PV
K), oxadiazole, organic liquids, such as phenylenediamine, or an inorganic liquid, such as zinc oxide (Z _n O). When zinc oxide is used as the photoconductor liquid, an organic solvent is used as the eluent.

The drying device 9 is for drying the photoconductor liquid 7 coated on the surface of the roll 1 and has a blow device (not shown) for blowing hot air or cold air to the roll 1.

The charging device 10 uniformly charges the coating layer of the photoconductor liquid 7 to one of positive and negative by corona discharge or the like.

The exposure device 11 includes a laser oscillator 12 that oscillates a laser beam, and a lens 1 that is oscillated from the laser oscillator 12.
A polygon mirror 16 that reflects the laser beam that has passed through 3 and 15 with a polygonal column mirror that rotates at high speed and scans the roll 1 at high speed.
And a roll 1 disposed between the lenses 13 and 15
And a modulator 14 for modulating a laser beam to be scanned thereon to expose a position corresponding to a non-image portion of the coating layer on the roller 1 so as to reduce the potential of the portion. At this time, in the present embodiment, the image output is converted to a halftone dot. Note that the exposure apparatus 11 may perform exposure using an array element of a semiconductor laser or a light emitting diode (LED).

An information input device 30 is connected to the modulator 14, the information input device 30 includes an image information output computer 21 for inputting image information to the modulator 14, and an image scanner connected to the computer 21. And a character input unit 23 such as a word processor.The modulator 14 of the exposure device 11 is controlled by digital image information output from a computer device 21. .

The toner developing device 17 attaches lipophilic toner (development powder) charged to the opposite sign to the charge charged on the coating layer to the coating layer. Here, examples of the toner include low-molecular-weight polystyrene, rosin-displaced maleic resin, and the like, as in a normal dry-type copying machine.

The fixing device 18 fixes the toner attached by the toner developing device 17 by a method of heating with a heating roller, an oven heater, or the like, or a method of mechanically pressing with a roller or the like.

The elution device 19 includes a nozzle 20 that can be separated from the roll 1 in the vicinity. When the nozzle 20 is in the vicinity of the roll 1, the nozzle 20 elutes the coating layer of the non-image area where no toner is attached. An alkaline solution is sprayed onto the surface of the roll 1 so that the hydrophilic surface is exposed in the non-image area. A device for supplying the alkaline solution to the nozzle 20 is not shown.

The cleaning device 26 prepares for a new printing by dropping the image portion of the toner formed on the roll 1 after the predetermined printing is completed, and for example, a rotating brush for scraping off the toner and a rotating brush for scraping the toner. The rotary brush is configured to be provided with a vacuum cleaner (not shown) for sucking the dropped toner, and the rotating brush is retracted from the roll 1 when not in use.

Around the roll 1, a dampening device 24 for supplying water to the peripheral surface of the roll 1 and an ink filling device 25 for applying ink to the peripheral surface of the roll 1 are arranged. Reference numeral 25 denotes an ink discharge roll 25A disposed in the ink reservoir, and a kneading roll group 25C which is in rolling contact with the roll 1.
And an ink transfer roller 25B for transferring the ink applied to the ink delivery roll 25A to the kneading roll group 25C. Further, a blanket cylinder 1 having a rubber layer formed on the surface thereof is roll-contacted with the roll 1, and an impression cylinder 3 is roll-contacted with the blanket cylinder 2.
When a sheet-shaped or web-shaped printing paper 4 is supplied from a paper feeding device (not shown) between the impression cylinders, the printing paper 4 is coated with ink on the image area and printed. Has become. The blanket cylinder 2, the dampening device 24 and the ink filling device 25 can be approached and separated from the roll 1.

Next, a printing method using this embodiment having the above-described configuration will be described with reference to FIG.

 First, the plate making process will be described.

First, prior to plate making, the nozzle 2 of the dissolution apparatus 19
0. The rotating brushes of the moistening device 24, the ink filling device 25, and the cleaning device 26 are separated from the roller 1.

Thereafter, the roller coater 8 of the coating device 5 is advanced, the photoconductor liquid 7 is applied to the rotating roll 1 to form a coating layer, and the coating layer is dried by the drying device 9. The dried coating layer
The charging device 10 uniformly charges either positive or negative. Further thereafter, the image input unit 22 of the information input device 21
And / or input information to be printed from the character input unit 23 to the image information computer 21. This computer 21
Sends this information to the modulator 14 of the exposure device 11, and the modulator 14 emits a laser beam oscillated from the laser oscillator 12 of the exposure device 11 and exposed and scanned on the roll 1 corresponding to the non-image portion. Control is performed to expose the position. At this time, in this exposed portion, the potential decreases and a latent image is formed.

Thereafter, the lipophilic toner charged by the toner phenomenon device 17 to the opposite sign to the charging of the coating layer is attached to the coating layer. The toner is attached to a portion where the potential has not decreased according to exposure, that is, an image portion. When the adhesion of the toner is completed, the fixing device 18 fixes the toner on the coding layer.

Thereafter, the nozzle 20 of the dissolution apparatus 19 is brought close to the roll 1, and the alkaline solution is supplied from the nozzle 20 to the roll 1.
To elute the coating layer in the non-image area, and further, the surface of the roll 1 is dried by the drying device 9. Thereby, the hydrophilic surface of the roll 1 is exposed in the non-image area. When this elution step is performed over the entire circumference of the roll 1, the nozzle 20 is separated from the roll 1, thereby completing the plate making step.

After the plate making process is completed, the printing process is started. Printing according to the present embodiment is the same as printing using a normal offset rotary printing press. That is, when the roll 1 is rotated while the blanket cylinder 2, the dampening device 24 and the ink filling device 25 are in contact with the roll 1, water is applied to the non-image area where the hydrophilic surface is exposed. On the other hand, the ink is applied to the image area where the lipophilic toner on the roll 1 is applied, and the ink applied to the image area is transferred to the blanket cylinder 2.
The image is printed on the printing paper 4 supplied between the blanket cylinder 2 and the impression cylinder 3. This printing is performed for each predetermined number of lots.

When the printing of the small lot is completed, the surface of the roll 1 is refreshed in preparation for the next printing. Therefore, the image area of the toner formed on the roll 1 is scraped off by the rotating brush of the cleaning device 26, and the scraped toner is sucked by a vacuum cleaner. Roll 1
Wash the surface. Further, the surface of the roll 1 is dried by the drying device 9 to bring the roll 1 into a state before plate making.

According to the present embodiment, in plate making, by inputting object information such as characters to the roll 1 directly from the object information input device 30 without going through the conventional plate making process, the plateless offset rotary printing is performed. Printing can be performed. Therefore, the plate making operation can be made easier than before, and the plate plate attaching operation can be eliminated. This is particularly simple for small lot printing, and is also effective as a desktop printer. Further, since the object information is directly input to the roll 1, there is no need to provide a step for mounting the printing plate as in the related art, so that the gap of the printing plate in the conventional offset rotary press can be eliminated. Further, since the blanket cylinder 2 can form a rubber roll having a uniform flat surface, it is possible to eliminate vibrations, doubling, and the like in the gap in the conventional offset rotary printing press. Moreover, since the coated photoconductor liquid is forcibly dried by the drying device 9, it is not necessary to wait until the coating layer dries in the step of printing the printing paper with the blanket cylinder 2 or the impression cylinder 3 when switching the plate. Therefore, printing can be performed quickly.

In the present invention, the arrangement of the coating device 5, the cleaning device 26, the dissolution device 19, the drying device 9 and the like around the roll 1 is not limited as in the above-described embodiment. Further, in the above-described embodiment, the latent image was formed by exposing the position corresponding to the non-image portion of the coating layer. However, in the present invention, on the contrary, the position corresponding to the image portion was exposed and the latent image was formed. May be formed. In this case, since the charge is lost by the exposure, it is conceivable that the toner cannot be transferred to the portion where the charge has been lost by exposing the image portion.

〔The invention's effect〕

According to the present invention as described above, the plate making operation is facilitated, the plate plate attaching operation can be omitted, and printing can be performed quickly.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention, and FIG. 2 is a flowchart showing an operation procedure of the embodiment. 1 ... roll, 2 ... blanket cylinder, 3 ... impression cylinder, 4
... printing paper, 5 ... coating device, 7 ... photoconductor liquid, 9 ... drying device, 10 ... charging device, 11 ... exposure device, 17 ... toner developing device, 18 ... fixing device, 19 …… elution device, 24 …… fountain solution device, 25 …… ink deposition device, 26
... cleaning device, 30 ... image information input device.

Claims (1)

(57) [Claims] 1. A roll comprising a surface of a hydrophilic powdery material, a blanket cylinder which rolls in contact with the roll, and an impression cylinder which rolls in contact with the blanket cylinder with the paper to be printed interposed between the roll and the blanket cylinder. A coating device that coats the photoconductor liquid on the peripheral surface of the roll, a drying device that blows air onto the roll to dry the coated photoconductor liquid, and a positive and negative coating layer of the photoconductor liquid. A charging device for charging one of them,
An exposure device for exposing a predetermined position of the coating layer to form an image portion on the roll; an information input device for inputting image information to the exposure device; and a positive or a negative for the charged coating layer. A toner developing device for attaching a charged lipophilic toner to the other, a fixing device for fixing the toner adhered by the toner developing device, and an elution device for removing a non-image portion of the coating layer;
An offset rotary printing press comprising: a dampening device for supplying water to the peripheral surface of the roll; and an ink depositing device for supplying ink to the peripheral surface of the roll.