JPH1120124A - Offset rotary press - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate replacement of a roll by adhering new hydrophilic toner of new print to the roll each time, thereby stably holding hydrophilic property. SOLUTION: A first toner developing unit 17 adheres lipophilic toner charged to opposite symbol to that of charging of a coating layer formed on a roll 1 to the coating layer. The toner is adhered to part in which a potential is not lowered in the case of exposure, i.e., a printing element part. Thereafter, the toner is fixed onto the coating layer by a fixing unit 18. Meanwhile, a second toner developing unit 32 adheres hydrophilic toner charged to symbol of the same direction as that of charging of the coating layer to the coating layer. The hydrophilic toner is repelled by the element part in which a potential is held even in the case of exposure, and attracted to a non-printing element part in which a potential is lowered. Thereafter, the toner on the coating layer is fixed by the unit 18. Thus, hydrophilic performance is stabilized and hence replacement of the roll is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an offset rotary printing press, and more particularly, to an improvement in plate forming means.

[0002]

2. Description of the Related Art In a conventional offset rotary printing press, a printing plate on which image information such as characters is printed on a peripheral surface of a plate cylinder (roll) is wound, and image information on the plate is once transferred to a blanket cylinder. Thereafter, printing is carried out by copying from a blanket cylinder onto printing paper.

In such an offset rotary printing press, it is necessary to perform a plate making operation of printing a photo on a printing plate.
This plate-making operation has a problem that it consumes time and money especially in small lot printing (printing with a small number of prints), and thus increases the printing cost. In addition, there is a problem that accurate positioning is required when the plate is made on a roll, and furthermore, a lot of labor and time are required, for example, a multicolor machine requires registration. . Further, when the printing plate is mounted on the roll, the roll is inserted into a groove provided in the axial direction of the peripheral surface of the roll and wound, so that when the groove portion comes into rotational contact with the counterpart roll during operation, pressure loss occurs. As a result, there is a problem that shock, vibration, and doubling occur. In order to solve these problems, the present applicant has a roll having a hydrophilic surface, a charging device and an exposure device for forming an electrostatic latent image by charging the surface corresponding to the image portion thereof, An offset rotary printing press provided with a toner developing device for charging a lipophilic-processed toner and supplying it to an image area serving as an electrostatic latent image has been previously proposed (Japanese Patent Application Laid-Open No. Hei 1-206048).

[0004]

In the offset printing, the maintenance of hydrophilicity is the most important issue. However, in the offset rotary printing press, the hydrophilicity of the roll having hydrophilicity is impaired by repeated use. The rolls need to be changed regularly. And this roll exchange operation in an offset rotary printing press requires a great deal of labor.

[0005] It is an object of the present invention to provide an offset rotary printing press which can easily perform a plate making operation, does not require a plate attaching operation, can stably maintain hydrophilicity, and does not require a roll change. Is to provide.

[0006]

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to make it possible to directly input image information such as characters to a roll on which a printing plate has been mounted, thereby making the web offset printing press non-printing and non-printing. This is to maintain the hydrophilic function of the image area. Specifically, the present invention relates to a roll, a blanket cylinder, a coating device, a drying device, a charging device, a first exposure device, a second exposure device, a driving device, an information input device, a first toner developing device, The second roll includes a toner developing device, a fixing device, a removing device, a cleaning device, a fountain solution device, and an ink filling device.
In particular, no special processing is required, and the blanket cylinder is configured to be in contact with a roll, and the impression cylinder is in contact with the blanket cylinder while sandwiching a printing paper to be printed between the blanket cylinder and the blanket cylinder. Wherein the coating device is configured to coat the photoconductor liquid on the peripheral surface of the roll, the drying device is configured to dry the photoconductor liquid of the coated roll, and the charging device is configured to: Is configured to charge the coating layer of the photoconductor liquid to one of positive and negative by, for example, corona discharge, and the first exposure apparatus is configured to form an image portion on the roll. A predetermined position of the coating layer, for example, is configured to be exposed by a laser beam or the like, the second exposure device,
The first toner developing device is constituted by, for example, a xenon lamp so as to expose the entire surface of the roll. The first toner developing device has a positively or negatively charged developing powder (lipophilic toner) opposite to the charged coating layer. Wherein the second toner developing device is configured to apply a charged developing powder (hydrophilic toner) to one of the same positive and negative as the charged coating layer,
The fixing device is configured to fix the toner attached in the first toner developing device and the second toner developing device, and the removing device removes the coating layer on the roll, the lipophilic toner, and the hydrophilic toner. The cleaning device is configured to scrape off, the cleaning device is configured to clean the peripheral surface of the roll after the removing operation by the removing device, and the dampening device is configured to supply water to the peripheral surface of the roll. The ink inking device is configured to supply ink to the peripheral surface of the roll.

In the present invention having the above-described structure, image information is input to the roll to form a lipophilic image portion with a lipophilic toner and a hydrophilic non-image portion with a hydrophilic toner. Thereafter, printing is performed by depositing ink on the lipophilic image area. In other words, first, the coating device coats the photoconductor liquid on the peripheral surface of the roll, charges the coating layer positively or negatively, and then applies the image information input to the information input device to the first exposure device. Scans the coating layer.

As a result, for example, when a non-image area is exposed, the potential of the exposed area is reduced and an electrostatic latent image is formed. Thereafter, the lipophilic toner charged to the opposite sign to the charge charged to the coating layer by the first toner developing device adheres to the non-exposed portion, that is, the image portion, and the toner is fixed by the fixing device. Further, the roll peripheral surface is again charged positively or negatively by the charging device, and the entire surface of the roll is exposed by the second exposure device. At the time of this exposure, the toner is fixed to the image portion in the previous stage, and the coating layer of the image portion is shielded by the toner and is not exposed. Therefore, the potential of the image portion is maintained, and the toner adheres. The potential of the non-existing portion is reduced, and the electrostatic latent image is formed again.

After that, the second toner developing device
A hydrophilic toner charged to the same sign as the potential charged to the coating layer adheres to an exposed portion, that is, to a non-image portion, and the toner is fixed by a fixing device. Thus, a lipophilic image portion where the lipophilic toner is fixed and a hydrophilic non-image portion where the hydrophilic toner is fixed are formed on the roll surface.

Next, when the dampening device and the ink filling device are operated in the same manner as in a normal offset rotary printing press, ink is applied to the lipophilic image portion while the hydrophilic non-image portion is applied. In the portion, the ink is not deposited due to the ink being repelled by the dampening solution, and a desired ink image can be formed on the peripheral surface of the roll. Further, the roll and the blanket cylinder are rotated, the ink image is transferred to the blanket cylinder that comes into contact with the roll, and printing paper is supplied between the blanket cylinder and the impression cylinder to perform offset rotary printing. After printing is completed, the coating layer, the lipophilic toner and the hydrophilic toner on the roll surface are scraped off by the removing device, and the roll peripheral surface is refreshed by cleaning with the cleaning device so as to prepare for the next printing.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the offset rotary printing press 40 of the present embodiment includes a roll 1, and the roll 1 is made of aluminum, steel, or the like. Around the roll 1, a coating device 5, a cleaning device 26, a removing device 19, a drying device 9, a charging device 10, a first exposure device 11, a second exposure device 31,
First toner developing device 17, second toner developing device 3
2 and a fixing device 18 are arranged along the rotation direction of the roll 1.

The coating apparatus 5 is provided with 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. ing. Here, the photoconductor liquid 7 is made of poly-N-vinylcarbazole (PV
K), an organic liquid such as oxadiazole or phenylenediamine, or an inorganic liquid such as zinc oxide (ZnO). 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 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 first exposure apparatus 11 includes a laser oscillator 12 for oscillating a laser beam, a polygon mirror 16 for rotating the laser beam oscillated from the laser oscillator 12 and passing through the lenses 13 and 15 at high speed, and a lens 13 and Fifteen
And a modulator 14 that modulates a laser beam scanned on the roll 1 and that exposes a position corresponding to a non-image portion of the coating layer on the roll 1 to reduce the potential of the portion. It is made to let. In this case, in the present embodiment, data obtained by halftoning image data by raster image processing is used. In addition,
The first exposure apparatus 11 may be of a type that performs exposure using an array element such as a semiconductor laser or a light emitting diode (LED).

A driving device 21 is connected to the modulator 14.
An information input device 30 having raster image processing is connected to the drive device 21. The information input device 30 is connected to the plate making data processing system 22, and the print data sent from the plate making data processing system 22 is received by the information input device 30, subjected to raster image processing, sent to the drive device 21, and The modulator 14 of the one exposure device 11 is controlled. When the first exposure device 11 is constituted by a semiconductor laser or an LED, the output of the information input device 21 controls a drive circuit of the semiconductor laser or the LED.

The second exposure device 31 is for exposing the whole surface of the coating layer, and is constituted by using a halogen lamp or a xenon lamp as a light source. Here, the first exposure apparatus 11 may be used as the second exposure apparatus 31, but it is preferable that the first exposure apparatus 11 be separately configured because it only satisfies the purpose of overall exposure. The first toner developing device 17 attaches lipophilic toner (developing powder) charged to the opposite sign to the charge charged on the coating layer to the coating layer. The second toner developing device 32 attaches a hydrophilic toner (development powder) charged in the same direction as the charge charged on the coating layer to the coating layer. Here, examples of the toner include low molecular weight polystyrene, rosin-displaced maleic acid resin, and the like, as in a normal dry copying machine.

The fixing device 18 is attached by the first toner developing device 17 and the second toner developing device 32 by a method of heating with a heating roll, an oven heater or the like, or a method of mechanically pressing with a roll or the like. This is for fixing the toner. Removal device 1
Reference numeral 9 denotes a rotary brush 20 for scraping off the toner formed on the roll 1 after predetermined printing is completed, and a vacuum cleaner (not shown) for suctioning the toner scraped off by the rotary brush 20. The rotating brush 20 is retracted from the roll 1 when not in use. The cleaning device 26 cleans the peripheral surface of the roll 1 after the coating layer, the lipophilic toner, and the hydrophilic toner on the peripheral surface of the roll 1 are scraped off by the removing device 19.

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. The meat device 25 is composed of an ink fountain 25A disposed in the ink reservoir, a kneading group 25C that is in rolling contact with the roll 1, and an ink transfer 25B that transfers the ink applied to the ink fountain roll 25A to the kneading roll group 25C. ing.

Further, a blanket cylinder 2 having a rubber layer formed on its surface is rolled on the roll 1, and an impression cylinder 3 is rolled on the blanket cylinder 2, and the blanket cylinder 2 and the impression cylinder 3 are shown between the blanket cylinder 2 and the impression cylinder 3. When a sheet-shaped or web-shaped printing paper 4 is supplied from a paper feeding device which is not used, the printing paper 4 is printed with the ink applied to the image area. The blanket cylinder 2, the dampening device 24, and the ink depositing device 25 can be approached or separated from the roll 1.

Next, a printing method using the present embodiment configured as described above will be described with reference to FIG.
First, the plate making process will be described. First, the rotating brushes of the dampening unit 24, the ink filling unit 25, and the removing unit 19 are separated from the roll 1 before the plate making. Thereafter, the roll coater 8 of the coating device 5 is advanced, and the photoconductor liquid 7 is applied to the rotating roll 1 to form a coating layer (first stage A). The coating layer is further dried by the drying device 9. (Second stage B). The dried coating layer is uniformly charged either positively or negatively by the charging device 10 (third stage C).

Thereafter, the plate making data processing system 2
2, the print data is sent to the information input device 30 and, after raster image processing, sent to the drive device 21 as exposure information. Based on this information, the laser beam oscillated from the laser oscillator 12 of the first exposure apparatus 11 and exposed and scanned on the roll 1 is controlled to expose a position corresponding to the non-image area (fourth stage D). At this time, in this exposed portion, the potential decreases and an electrostatic latent image is formed. Thereafter, the lipophilic toner charged by the first toner developing device 17 with the opposite sign to the charging of the coating layer is attached to the coating layer (fifth stage E). The lipophilic toner is attached to a portion where the potential has not decreased with exposure, that is, an image portion. After the attachment of the lipophilic toner is completed, the lipophilic toner is fixed on the coating layer by the fixing device 18 (6th stage F).

Next, charging is performed again by the charging device 10 to a potential in the same direction as previously (seventh stage G). Thereafter, the entire surface of the coating layer is exposed by the second exposure device 31 (8th stage H). By this exposure, the image portion where the lipophilic toner is fixed on the coating layer is prevented from being exposed by the lipophilic toner and the potential is maintained, but the portion where the lipophilic toner is not attached, that is, the non-image portion The potential of the part decreases.

Thereafter, the hydrophilic toner charged by the second toner developing device 32 in the same direction as the charge of the coating layer is adhered to the coating layer (9th stage I). The hydrophilic toner is repelled by the image area where the electric potential can be maintained even by exposure, and is attracted to the non-image area where the electric potential has decreased. Thereafter, the toner on the coating layer is fixed by the fixing device 18 (10th stage J). As a result, the plate making process is completed and the printing process is started.

The printing according to the present embodiment is the same as the 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 adheres to the non-image area where the hydrophilic toner has adhered. On the other hand, the image area on the roll 1 to which the lipophilic toner has adhered is filled with ink (stage 12L), and the ink adhered to the image area is removed from the blanket cylinder. 2
Is transferred onto the printing paper 4 supplied between the blanket cylinder 2 and the impression cylinder 3 (14th stage N). This printing is performed for each predetermined number of lots.

When printing of a small lot is completed, the surface of the roll 1 is refreshed in preparation for the next printing. Therefore, the coating layer formed on the roll 1, the image portion of the lipophilic toner, and the non-image portion of the hydrophilic toner were scraped off by the rotary brush 20 of the removing device 19 (15th stage O) and scraped off. The toner is sucked by a vacuum cleaner, and thereafter, an alkaline solution is sprayed onto the roll 1 from the cleaning device 26 to clean the peripheral surface of the roll 1 (16th stage P). Further, the peripheral surface of the roll 1 is dried by the drying device 9 to bring the roll 1 into a state before plate making (17th stage Q).

According to this embodiment, the following effects can be obtained. The maintenance and stability of hydrophilicity, which is the most important issue in printing, can be easily achieved because the non-image area is formed by attaching a new hydrophilic toner every time printing is performed. Since a new hydrophilic toner is attached to the roll 1 every time a new print is performed, it is not necessary to prepare a special roll that has been subjected to a hydrophilic treatment, and therefore, there is no need to replace the roll. .

In plate making, by directly inputting image information such as characters to the roll 1 from the image information input computer 30 without going through the conventional plate making process, plateless offset rotary printing can be performed. . Therefore, the plate making operation can be made easier than before, and the plate mounting operation can be omitted. This is particularly convenient for small lot printing, and is also effective as a desktop printer.

Since the object information is directly input to the roll 1, there is no need to provide a step for attaching the printing plate as in the prior art, and therefore, the gap of the printing plate in the conventional offset rotary press can be eliminated. Since the blanket cylinder 2 can also be made of rubber having a uniform flat surface, it is possible to eliminate vibrations, doubling, and the like at the gap in the conventional offset rotary printing press.

The present invention is not limited to the above-described embodiment, but includes the following modifications as long as the object of the present invention can be achieved. That is, the arrangement state of the coating device 5, the cleaning device 26, the removing device 19, the drying device 9 and the like around the roll 1 is not limited to the arrangement as in the above embodiment, but may be changed as appropriate. Further, in the embodiment, the position corresponding to the non-image area of the coating layer is exposed by the first exposure device to form an electrostatic latent image. In the present invention, on the contrary, in the image area, A corresponding position may be exposed to form an electrostatic latent image.

[0030]

As described above, according to the web offset printing press of the present invention, the hydrophilicity performance is stabilized, the roll exchange for this is not required, the plate making operation becomes easy, and the plate making operation becomes easy. This has the effect of eliminating the need for plate mounting work.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a schematic configuration of an offset rotary printing press according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating an operation procedure of the offset rotary printing press of the present embodiment.

[Explanation of symbols]

 1: Roll 2: Blanket cylinder 3: Impression cylinder 4: Printing paper 5: Coating device 9: Drying device 10: Charging device 11: First exposure device 17: First toner developing device 18: Fixing device 19: Removal device 21: Driving device 22: Plate making data processing system 24: Dampening solution device 25: Ink deposition device 26: Cleaning device 30: Information input device 31: Second exposure device 32: Second toner developing device

Claims (1)

[Claims] 1. A rotary offset printing press for printing on printing paper, comprising: a roll on which a print image is written; a blanket cylinder which rolls on the roll; and the printing paper for printing sandwiched between the blanket cylinder. An impression cylinder that rolls into contact with a blanket cylinder in a state, a coating device that coats a peripheral surface of the roll with a photoconductor liquid, a drying device that dries the photoconductor liquid coated on the peripheral surface of the roll, and the photoconductive member. A charging device that charges the coating layer of the bodily fluid to one of positive and negative; a first exposure device that exposes a predetermined position of the coating layer to form an image portion on the roll; A second exposure device that exposes the entire surface of the coating layer to form a line portion, and a driving device that drives the first exposure device according to print information. A device, an information input device for inputting image information to the driving device, a first toner developing device for attaching a positive or negative charged lipophilic toner to the charged coating layer, and A second toner developing device for attaching a positively or negatively charged hydrophilic toner to the charged coating layer; and a lipophilic toner and a second toner attached by the first toner developing device. A fixing device that fixes the hydrophilic toner attached by the developing device; a removing device that removes the coating layer, the lipophilic toner, and the hydrophilic toner from the peripheral surface of the roll; A cleaning device for cleaning the peripheral surface of the roll, a dampening device for supplying water to the peripheral surface of the roll, and an ink filling device for supplying ink to the peripheral surface of the roll. An offset rotary printing press characterized by including and including.