Background Art Generally, a web type offset printer comprises a paper feeder for feeding print paper from a paper roll, an offset print unit for performing printing on the fed print paper, a cutter for cutting the printed paper, and a delivery unit capable of stacking sheets of the cut paper. Offset printing is a printing method by which printing ink is transferred from a printing plate to print paper not directly but through a blanket. An offset printing unit is provided with an inking unit for supplying ink, a damping unit for supplying water, a printing plate, a blanket, and the like.

Of general web type offset printers having such a configuration, there has not been known a web type offset printer capable of continuously performing printing directly on adhesive paper to which an adhesive is applied. The reason is that it is difficult to accurately adjust tension and align registration of the adhesive paper when the paper passes by rollers of a paper feeder and a cylinder of the printing unit of an offset printer. This is because the adhesive adheres to rollers of a paper feeder and a cylinder of the printing unit of an offset printer when the adhesive paper passes by the rollers and cylinder.

As for conventional methods of manufacturing adhesive note pads with memo surfaces on which specific characters or figures are printed, there is a method comprising the steps of printing the characters or figures on plain paper, additionally applying an adhesive to a back surface of the paper, and cutting the paper in a proper size. A printer for performing printing using such a method is disclosed in Korean Utility Model Registration No. 20-282324 entitled"Apparatus for manufacturing adhesive note pad"that was filed on April 15,2002.

However, such a method is troublesome in that an adhesive is additionally applied to printed paper. Particularly, in case of the contents should be printed in colors and in a small amount, printing costs are high and thus the economic efficiency is lowered.

Therefore, there are many cases where adhesive note pads are difficult to be manufactured in practice.

To solve the problem, there has been proposed print paper in which a peelable strip is attached to a surface of the print paper with an adhesive applied thereto so that it can be fed to a printer and then subjected directly to printing. The print paper is disclosed in Korean Utility Model Registration No. 20-247226 entitled"Print paper for computer" that was filed on June 11,2001.

However, since the print paper requires the additional process of attaching the peelable strip to the adhesive-applied surface of the print paper, additional costs are incurred and it is necessary to additionally remove the peelable strip in a case where the print paper is intended to be manufactured in the form of the conventional adhesive note pad.

Therefore, there is a need for a web type offset printer capable of rapidly printing specific characters or figures in colors and in a great amount without attaching an additional sheet of paper such as a peelable strip to an adhesive surface of adhesive paper.

Disclosure of Invention The present invention is conceived to solve the aforementioned problems. An object of the present invention is to provide a web type offset printer that has rollers and impression cylinders specially processed to allow printing to be performed directly on adhesive paper without attaching an additional sheet of paper such as a peelable strip.

Another object of the present invention is to provide a web type offset printer, wherein upon cutting printed adhesive paper and stacking the cut sheets of printed paper on a stack stand, nozzles of the offset printer inject air below the sheets of printed paper to accurately stack the sheets of printed paper, thereby preventing the sheets of printed paper from being poorly stacked due to adhesives applied to lower surfaces of the sheets.

A further object of the present invention is to provide a web type offset printer,

wherein upon cutting printed adhesive paper and stacking the cut sheets of printed paper on a stack stand, a static electricity-removing device of the offset printer can remove static electricity generated at top and bottom surfaces of the sheets of print paper, thereby preventing the sheets of printed paper from being poorly stacked due to the static electricity generated on the sheets.

To achieve these objects, the web type offset printer of the present invention comprises a paper feeder for feeding adhesive paper from a roll thereof, a plurality of printing units for performing printing on the adhesive paper fed from the paper feeder, and a cutting/delivery unit for cutting and discharging the adhesive paper on which the printing has been performed by the plurality of printing units. A metal material is coated on surfaces of a plurality of rollers that are installed in the paper feeder to guide the adhesive paper fed into the printing units, by using thermal spray coating. The metal material is also coated on surfaces of impression cylinders installed in the printing units by using the thermal spray coating.

In the offset printer of the present invention, the paper feeder may be provided with a scraping means which comes into contact with a surface of the adhesive paper to which an adhesive has not been applied, thereby scraping the contact surface when the adhesive paper is fed into the printing units.

Further, in the offset printer of the present invention, the scraping means may comprise a scraping bar with a blade having a length greater than the width of the print paper, and brackets for fixing both ends of the scraping bar to a shaft of the plurality of rollers installed in the paper feeder.

In the offset printer of the present invention, the scraping means may further comprise a pivoting means for pivoting the roller shaft with the brackets installed thereon to adjust contact pressure between the scraping bar and the adhesive paper.

In the offset printer of the present invention, the paper feeder may further comprise an edge position adjustor for the adhesive paper, and the edge position adjustor comprises a sensor for detecting the position of an edge of the print paper, a controller for receiving signals from the sensor and outputting control signals for adjusting the edge position, and a paper rotating means for rotating a first roller and a second roller through a predetermined

angle with respect to an axis in response to the control signals from the controller, wherein the first and the second roller are installed in parallel and comes into contact with a surface of the print paper to which an adhesive has not been applied to guide the adhesive paper, the axis is perpendicular to the surface formed by the axes of the first and the second roller and located at the center of the length of the first roller.

Furthermore, in the offset printer of the present invention, the size of particles of the metal material coated on the surfaces of the plurality of rollers may be in a range of 200 to 300 meshes, and the size of particles of the metal material coated on the surfaces of the impression cylinders may be in a range of 300 to 500 meshes.

According to the present invention, the surfaces of the rollers and impression cylinders of the paper feeder are coated with the metal material, so that the stickiness of the adhesive of the adhesive paper to the rollers and the impression cylinders can be weakened as compared with conventional rollers and impression cylinders which are not coated with a metal material, thereby reducing the influence of the stickiness upon performing printing.

Particularly, when the outer periphery of each impression cylinder is coated with a metal material having particles of 300 to 500 meshes in size, it is possible to eliminate printing defects resulting from convexo-concave portions on the surface of the impression cylinder and simultaneously reduce the stickiness of the adhesive to the surface of the impression cylinder.

In the offset printer of the present invention, the cutting/delivery unit may comprise a cutting roller for cutting the adhesive paper on which the printing has been performed into sheets having a proper length, a feeding roller for discharging the sheets of adhesive paper cut by the cutting roller, a stack stand for stacking the sheets of adhesive paper discharged by the feeding roller thereon, and air supply nozzles for controlling the falling of the sheets by injecting air below the sheets to be stacked on the stack stand, and wherein a surface of the feeding roller is coated with the metal material.

Further, in the offset printer of the present invention, predetermined portions of the coated surface of the feeding roller may be circumferentially formed with grooves having a predetermined depth, and the air supply nozzles may be installed within the grooves not to protrude beyond a plane in which the adhesive paper passes on the feeding roller.

Further, the offset printer of the present invention may further comprise a first static electricity-removing device installed between the cutting roller and the feeding roller in the cutting/delivery unit to remove static electricity generated on a surface of the adhesive print paper to which the adhesive has been applied, and a second static electricity- removing device installed above the stack stand to remove static electricity generated on the surface opposite to the adhesive-applied surface of the adhesive print paper.

According to the present invention, when the adhesive paper on which printing has been performed is cut into the sheets of a predetermined length and the sheets are then stacked on the stack stand, air is injected toward the bottom surfaces of the sheets to which the adhesive has been applied so that the sheets can be moved to a stack position, thereby preventing the occurrence of stacking defects resulting from the adhesion of the sheets to stacked sheets due to the adhesive.

Brief Description of Drawings FIG. 1 is a schematic perspective view of a web type offset printer for adhesive paper according to an embodiment of the present invention.

FIG. 2 is a schematic view of a paper feeder of the web type offset printer for adhesive paper according to the embodiment of the present invention.

FIG. 3 is a detailed perspective view showing an installation state of a scraping means of the web type offset printer for adhesive paper according to the embodiment of the present invention.

FIG. 4 is a perspective view of one of rollers installed in the web type offset printer for adhesive paper according to the embodiment of the present invention.

FIG. 5 is an exploded perspective view showing the structure of an edge position adjustor of the web type offset printer for adhesive paper according to the embodiment of the present invention.

FIG. 6 is a schematic perspective view of a cutting/delivery unit of the web type offset printer for adhesive paper according to the embodiment of the present invention.

100: Paper feeder

110: Tension measuring roller 130: Infeed roller 150: Scraping means 160: Edge position adjustor 200: Printing unit 220: Impression cylinder 230: Blanket cylinder 300: Cutting/delivery unit 310 : Cutting roller 320: Feeding roller 330,340 : Static electricity-removing device 350: Air supply nozzle 370: Stack stand Best Mode for Carrying out the Invention Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic perspective view of a web type offset printer for adhesive paper according to an embodiment of the present invention.

As shown in FIG. 1, the web type offset printer for adhesive paper according to the embodiment of the present invention comprises a paper feeder 100 for feeding print paper from a roll of adhesive paper into printing units, the four printing units 200 for performing printing on the adhesive paper fed from the paper feeder, and a cutting/delivery unit 300 for cutting the adhesive paper on which the printing has been performed by the printing units and stacking the cut sheets of printed paper on a stack stand. An adhesive has been applied, at a predetermined interval, to a bottom surface of the adhesive paper wound in the form of a roll. The adhesive has not been applied to a top surface of the paper for the purpose of printing. Although the four printing units are provided in the embodiment, the present invention is not limited thereto. The number of printing units may be increased or decreased according to the purpose of printing.

FIG. 2 is a schematic view of a paper feeder of the web type offset printer for adhesive paper according to the embodiment of the present invention, FIG. 3 is a detailed perspective view showing an installation state of a scraping means of the web type offset printer for adhesive paper according to the embodiment of the present invention, and FIG.

4 is a perspective view of one of rollers installed in the web type offset printer for adhesive paper according to the embodiment of the present invention.

Problems produced in performing printing on adhesive print paper by a typical web type offset printer are that it is difficult to adjust tension of the print paper due to an adhesive applied to the bottom surface of the adhesive print paper, remnants of the adhesive adhering to the printing surface of the print paper upon unwinding of the print paper from a roll thereof contaminate a blanket cylinder of each printing unit, and the adhesive applied to the bottom surface of the print paper adheres to an impression cylinder resulting in difficulty in aligning registration. This is because a surface of a conventional roller is coated with hard chrome or a heat-treated stainless steel roller is used and thus it is impossible to reduce the stickiness of the adhesive to the roller.

To solve the problems, the present invention employs a metal film 400 formed on a surface of each of all rollers of the paper feeder by using thermal spray coating in order to reduce the stickiness of the adhesive to the roller, as shown in FIG. 4. Since a surface of an impression cylinder of each of the printing units also comes into contact with the adhesive of the print paper, the surface of the impression cylinder is coated with metal by using the thermal spray coating in order to reduce the stickiness of the adhesive to the impression cylinder. It is preferred that the thermal spray coating be performed by means of plasma spray coating. Preferably, the coated metal material includes, but not limited to, powder with tungsten and cobalt mixed therein. However, it is preferred that the size of the powder used in the thermal spray coating be in a range of 200 to 400 meshes, whereby the stickiness of the adhesive to the surface of the roller can have little influence on tension applied to the adhesive print paper. Particularly, as shown in FIG. 2, it is preferred that powder of 200 to 300 meshes be used for the rollers 111 to 125 of the paper feeder and finer powder of 300 to 400 meshes be used for the impression cylinder 220 to achieve precise printing.

In FIG. 2, reference numeral 110 designates a cylinder for measuring tension applied to the print paper, reference numeral 130 designates an infeed roller of the paper feeder, reference numeral 101 designates wound adhesive paper, and reference numeral 120 designates a shaft for supporting the paper.

FIG. 3 shows a scraping means 150 for removing remnants of the adhesive present on the top surface of the print paper when the adhesive print paper is unwound from the roll in a state where the top surface of the paper on which printing is made adheres to the surface of the paper to which the adhesive is applied. The scraping means 150 is constructed to be in contact with the surface of the paper to which the adhesive is not applied and to scrape the contacted surface when the adhesive print paper is fed into the printing unit. That is, the scraping means comprises a scraping bar 152 with a blade having a length greater than the width of the print paper, a pair of brackets 151 for fixing both ends of the scraping bar 152 to a shaft of the plurality of rollers installed in the paper feeder, and a pivoting means 153 for pivoting the roller shaft with the brackets 151 installed thereon to adjust contact pressure between the scraping bar and the print paper.

Although not shown in the figure, the pivoting means 153 is constructed such that it is connected via a worm gear to the shaft of the roller 114 with the brackets installed thereon so that the rotation of the pivoting means 153 causes the shaft of the roller 114 connected thereto via the worm gear to be rotated. It will be apparent that those skilled in the art can conceive a mechanism for rotating the shaft of the roller 114, in addition to the configuration. It is possible to properly adjust the amount of removal of the remnants of the adhesive adhering to the top surface of the print paper by pivoting the scraping bar 152 to change frictional force between the scraping bar 152 and the top surface of the print paper. Reference numeral 154 designates a bolt for fixing the relevant bracket.

FIG. 5 is an exploded perspective view showing the structure of an edge position adjustor of the web type offset printer for adhesive paper according to the embodiment of the present invention.

The edge position adjustor 160 comprises a sensor 181 for detecting the position of an edge of the paper, a controller 180 for receiving signals from the sensor and outputting control signals for adjusting the edge position, and a paper rotating means for

rotating a first roller and a second roller through a predetermined angle with respect to an axis in response to the control signals from the controller, wherein the first and the second roller are installed in parallel and comes into contact with a surface of the print paper to which an adhesive has not been applied to guide the adhesive paper, the axis is perpendicular to the surface formed by the axes of the first and the second roller and located at the center of the length of the first roller.

As shown in FIG. 5, the paper rotating means comprises a roller support 169 for rotatably supporting the two horizontal rollers, and a means for rotating the roller support through a predetermined angle about an axis perpendicular to the axis of the first roller 120 fixed to the roller support and disposed upstream of the feeding of the adhesive print paper.

In this embodiment, the means for rotating the roller support in response to the control signals from the controller comprises a hydraulic cylinder 165 of which one end is fixed to a portion of the roller support below a support shaft for the second roller 121 and the other end is fixed to a base plate 161, a pin 167 fixed to the base plate 161 and engaged with an inner race of a bearing 168 to pivotably support a portion of the roller support below the center of a shaft for the first roller, and a pair of ball guides fixed below the second roller 121 to be pivotably and linearly moved. Reference numeral 182 is a valve for controlling the hydraulic cylinder. An outer race of the bearing 168 is engaged with a recess 170a formed in the bottom of the roller support 169.

The pair of ball guides comprises a pair of guide rods 163 symmetrically and pivotably fixed to the base plate 161, and a pair of guide members 164 having bores fitted around the respective guide rods 163 to be movable linearly and further having pins protruding perpendicularly to the guide rods. The guide members can smoothly move linearly due to balls contained therein. The pins of the guide members 164 are engaged with and rotatably supported by the inner races of the respective bearings installed within recesses 170b formed symmetrically at portions of the roller support near the second roller.

Therefore, the edge position adjustor 160 can adjust the position of the edge of the print paper fed into the printing unit 200 by moving the cylinder 165 forward or rearward in response to control signals of the controller 180 based on detection signals from the sensor 181.

FIG. 6 is a schematic perspective view of a cutting/delivery unit of the web type offset printer for adhesive paper according to the embodiment of the present invention Generally, if adhesive paper on which printing has been made is cut into sheets that in turn are delivered to a stack stand by a conventional delivery unit, there is a problem in that the sheets adhere to a floor of the stack stand due to the adhesive applied to the bottom surface of the print paper and thus cannot be accurately stacked in an aligned state.

Further, there is a disadvantageous in that upon carrying the cut sheets of print paper by a feeding roller, they cannot be properly carried due to the adhesive.

To solve these problems, the present invention employs Teflon coating of a floor 360 between a cutting roller 310 and a feeding roller 320 for discharging sheets of adhesive print paper cut by the cutting roller, as shown in FIG. 6. Further, a plurality of air supply nozzles 350 are installed to control the falling of the cut sheets of adhesive print paper discharged through the feeding roller 320 by injecting air below the sheets so that the sheets can be accurately discharged to and stacked on the stack stand 370. The air supply nozzles 350 are installed within grooves having a predetermined depth formed circumferentially at predetermined portions of a coated surface of the feeding roller 320 so that they cannot interfere with the carrying of the print paper.

Further, to remove static electricity generated on the both surfaces of each of the cut sheets of print paper, a first static electricity-removing device 330 is installed between the cutting roller 310 and the feeding roller 320 to remove static electricity generated on the adhesive-applied surface of the adhesive print paper, and a second static electricity- removing device 340 is installed above the stack stand 370 to remove static electricity generated on the surface opposite to the adhesive-applied surface of the adhesive print paper.

Therefore, with the air injected by the air supply nozzles, the cut sheets of adhesive print paper can be accurately discharged to and stacked on the stack stand 370 in a state where the static electricity has been completely removed from the sheets, even though the adhesive has been applied to the bottom surfaces of the sheets.

Industrial Applicability

According to the present invention, printing can be performed directly on adhesive paper without attaching an additional sheet of paper such as a peelable strip thereto.

Therefore, it is possible to economically manufacture various types of adhesive note pads printed in colors and in small amounts.

The embodiment of the present invention described above and illustrated in the drawings should not be construed as defining the technical spirit of the present invention.

The scope of the invention is defined only by the appended claims and those skilled in the art can make various modifications and changes within the technical sprit of the invention.

Therefore, such modifications and changes fall within the scope of the invention so long as they are obvious to those skilled in the art.