KR20100028687A - Offset printing device - Google Patents

Abstract

PURPOSE: An offset printing device is provided to prevent paste from being dried by automatically mixing paste using a mixing slider in an offset print process. CONSTITUTION: An offset printing device(100) comprises a paste feeding unit(12), a gravure roll(16), a doctor unit(14), a blanket roll(18), and a paste collecting box(20). A concave groove(161) is formed on the gravure roll. The doctor unit is contacted with a gravure roll and washes the paste(P) which is attached on the surface of the gravure roll. The blanket roll prints the paste which is transcribed on the substrate. The paste collecting box stores remaining paste after the completion of the print.

Description

Offset printing device {OFFSET PRINTING DEVICE}

The present invention relates to an offset printing apparatus, and more particularly, to an offset printing apparatus capable of efficiently collecting the remaining paste after the printing operation is completed.

Recently, various kinds of display devices have been developed. For example, flat panel displays such as plasma display panels (PDPs), liquid crystal displays (LCDs), and organic light emitting diode displays (OLEDs) have been developed. Such flat panel display devices are thin and light, and thus are used in many products requiring image display.

The offset printing method is widely used to form the electrode or the electromagnetic shielding filter included in the aforementioned display devices. In the offset printing method, the paste is printed on the printed matter using a blanket roll serving as an intermediate medium rather than printing the paste directly on the printed matter.

It is an object of the present invention to provide an offset printing apparatus capable of efficiently collecting the remaining paste after an offset printing operation is completed.

An offset printing apparatus according to an embodiment of the present invention includes: (i) a paste supply unit for supplying paste, ii) a gravure roll for forming a recess for receiving paste on a surface thereof, and Is applied to temporarily receive the concave grooves, the doctor unit is in contact with the gravure roll to wipe the paste adhered to the surface of the gravure roll, iii) the gravure roll in contact with the paste received in the concave groove is transferred, and the transferred paste A blanket roll for printing on a substrate, and iii) a paste collecting box for supplying and storing the paste remaining after the printing is completed in connection with the doctor unit.

The doctor unit comprises: (i) a doctor portion in contact with the gravure roll, ii) a guide portion positioned between the paste supply unit and the doctor portion to guide the paste supplied from the paste supply unit onto the doctor portion, and iii) both ends of the doctor portion. It may include a pair of edge dams installed to face each other.

An outlet may be formed at one or more edge dams of the pair of edge dams, and the paste collection box may be connected to the outlet. The outlet may be located at the bottom of the edge dam. The doctor portion may form an inclined portion at the end toward the discharge port, the height of which decreases closer to the discharge port.

The outlet is formed in one of the edge dams of the pair of edge dams, and the vertical length of the edge dam with the outlet may be greater than the vertical length of the other edge dam without the outlet. The top of the pair of edge dams may be located at the same height relative to the ground.

The offset printing apparatus may further include i) a guide tube interconnecting the outlet port and the paste collection box, and ii) a control valve installed in the guide tube to control the opening and closing of the guide tube. The offset printing apparatus may further include a scale installed at the bottom of the paste collection box to measure the weight of the paste.

The offset printing apparatus includes: (i) a stirring slider which is located at the top of the doctor portion to stir and push out the paste contained on the doctor portion, and ii) a stirring slider driving portion which is coupled with the stirring slider to move the stirring slider along the axial direction of the gravure roll. It may further include.

The stirring slider may be exposed over the paste received over the doctor portion. The stirring slider may have a width smaller than the gap between the guide portion and the gravure roll. The stirring slider may further include a buffer member fixed to an end contacting the doctor portion.

The stirring slider drive may include: i) a gear shaft passing through the agitating slider; ii) a motor for generating power to rotate the gear shaft; .

The offset printing apparatus may further include a fixing block that is installed on each of the pair of edge dams. The motor is installed in the stationary block, and both ends of the gear shaft and both ends of the movement guide may be supported by the stationary block.

The stirring slider may form a first opening into which the gear shaft is fitted and a second opening into which the movement guide is fitted. Threads may be formed on the sidewalls of the first opening, and the second opening may have a diameter larger than that of the moving guide.

After the offset printing process is completed, the remaining paste can be easily discharged into the paste collection using the stirring slider. Therefore, it is possible to increase workability by replacing manual work, and reduce the process cost by reusing paste.

In addition, the paste may be automatically stirred using the stirring slider in the offset printing process. Accordingly, the paste may be prevented from drying and the dispersibility of the paste may be increased to increase the offset printing quality.

When a portion is referred to as being "above" another portion, it may be just above the other portion or may be accompanied by another portion in between. In contrast, when a part is mentioned as "directly above" another part, no other part is intervened in between.

Terms indicating relative space such as "below" and "above" may be used to more easily explain the relationship of one part to another part shown in the drawings. These terms are intended to include other meanings or operations of the device in use with the meanings intended in the figures. For example, turning the device of the figure upside down, certain parts described as being "below" of another part are described as being "above" other parts. Thus, the exemplary term "down" includes all the down directions. The device can be rotated 90 degrees or at other angles, the terms representing relative space being interpreted accordingly.

The terminology used herein is for reference only to specific embodiments and is not intended to limit the invention. As used herein, the singular forms “a,” “an,” and “the” include plural forms as well, unless the phrases clearly indicate the opposite. As used herein, the term "comprising" embodies a particular property, region, step, operation, element, and / or component, and the presence or addition of other specific property, region, step, operation, element, component, and / or group. It does not exclude.

Unless defined otherwise, all terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. Commonly defined terms used are additionally interpreted as having a meaning consistent with the related technical literature and the presently disclosed contents, and are not interpreted in an ideal but very formal sense unless defined.

Embodiments of the invention described with reference to perspective views, side views, and cross-sectional views specifically illustrate ideal embodiments of the invention. As a result, various modifications of the drawings, for example, manufacturing methods and / or specifications, are expected. Accordingly, the embodiment is not limited to the specific form of the illustrated region, but includes, for example, modification of the form by manufacture. Accordingly, the regions shown in the figures are only approximate in nature, and their forms are not intended to depict the exact form of the regions and are not intended to narrow the scope of the invention.

1 is a perspective view schematically showing an offset printing apparatus 100 according to an embodiment of the present invention, and FIG. 2 shows the doctor unit 14 and the gravure roll 16 of FIG. 1. It is a schematic front view.

The structure of the offset printing apparatus 100 shown in FIG. 1 is merely for illustrating the present invention, and the present invention is not limited thereto. Therefore, the structure of the offset printing apparatus 100 can be modified into other forms. In addition, although the offset printing apparatus 100 of FIG. 1 further includes other apparatuses for driving, these apparatuses are easily understood by those skilled in the art, and thus, they are omitted in FIG. 1 for convenience. To show.

1 and 2, the offset printing apparatus 100 includes a paste supply unit 12, a doctor unit 14, a gravure roll 16, and a blanket roll 18. In addition, the offset printing apparatus 100 further includes a paste collection box 20, a stirring slider 22, and a stirring slider driver 24. In addition, the offset printing apparatus 100 may further include other components as necessary.

The paste supply unit 12 includes a header 26 for storing the paste P, and a plurality of discharge portions 28 for evenly discharging the paste P stored in the header 26. Here, the paste P is interpreted to mean all liquids capable of offset printing. The structure of the paste supply unit 12 is not limited to the illustrated example, and can be variously modified.

The doctor unit 14 includes a doctor portion 30 in contact with the gravure roll 16, a guide portion 32 (shown in FIG. 2) located between the paste supply unit 12 and the doctor portion 30, and It includes a pair of edge dams (34) formed at a predetermined height at both ends of the doctor portion (30). The discharged paste P flows down the guide part 32 and is received on the doctor part 30 without leakage by the pair of edge dams 34.

The doctor unit 30 may be manufactured in the form of a plate. One end of the doctor portion 30 is fixed to the support 36, and the other end protrudes from the support 36 in the x-axis direction to be in close contact with the surface of the gravure roll 16. Therefore, the doctor part 30 may receive the paste P on one end of the protruding doctor part 30 while being stably fixed to the support 36.

The guide part 32 includes a fixed plate 38 fixed to the support 36, and a first guide plate 40 and a second guide plate 42 for guiding the flow of the paste P.

One end of the fixing plate 38 is fixed to the support 36, and the other end protrudes from the support 36 toward the x-axis direction. The end of the fixing plate 38 is spaced apart from the gravure roll 16. To this end, the length of the fixing plate 38 protruding from the support 36 is made smaller than the length of the doctor portion 30 protruding from the support 36. The sealing member 44 is positioned between the fixed plate 38 and the doctor portion 30 to prevent the leakage of the paste P.

The first guide plate 40 and the second guide plate 42 are inclined with respect to the ground. The first guide plate 40 may be formed to be steeper than the second guide plate 42, and may be formed to have a greater length than the second guide plate 42 along the flow direction of the paste P. The first and second guide plates 40 and 42 naturally lead the paste P discharged from the paste supply unit 12 downward. Therefore, the paste P can stably flow down between the guide part 32 and the gravure roll 16. FIG.

The guide part 32 of FIGS. 1 and 2 may be omitted, and the paste P may be directly supplied on the doctor part 30 in the paste supply unit 12. Assuming that there is no guide portion 32, the paste P is directly discharged to the upper portion of the doctor unit (14). In this case, the paste P spreads widely in contact with the support 36 and can easily leak to the outside.

The pair of edge dams 34 are installed to face each other at both ends of the doctor part 30 along the y-axis direction. The pair of edge dams 34 abut on both sides of the gravure roll 16 to seal therebetween. Therefore, the paste P flowing down through the guide part 32 is accommodated between the guide part 32 and the gravure roll 16 without leakage.

The gravure roll 16 forms a plurality of concave grooves 161 on the surface thereof, and receives the paste P in the concave grooves 161 while rotating in one direction (counterclockwise in FIG. 1). At this time, the doctor unit 30 wipes the paste P deposited on the surface of the gravure roll 16 while contacting the surface of the gravure roll 16.

The blanket roll 18 is in contact with the gravure roll 16 while being rotated in the opposite direction (clockwise in FIG. 1) from the gravure roll 16 to transfer the paste P therefrom. In addition, the blanket roll 18 applies the paste P transferred from the gravure roll 16 onto the substrate S while being in contact with the substrate S. Offset printing proceeds in the manner described above.

3 is a right side view schematically showing the doctor portion 14, the pair of edge dams 34, and the paste collection box 20 of FIG.

1 and 3, the offset printing apparatus 100 includes a discharge pipe 341 formed in the edge dam 34, a guide pipe 46 connecting the discharge hole 341 and the paste collection box 20, and a guide. A control valve 48 installed in the pipe 46.

The discharge port 341 and the guide tube 46 are opened after the offset printing process is completed to discharge the remaining paste P accommodated on the doctor unit 30 to the paste collection box 20. The scale 50 is installed at the bottom of the paste collection box 20 to measure the weight of the collected paste.

The outlet 341 may be provided at one edge dam 34 of the pair of edge dams 34. In addition, the outlet 341 may be located at the bottom of the edge dam 34. Therefore, the entire amount of the paste P remaining after the offset printing process is completed may be discharged to the paste collection box 20.

The doctor unit 30 may form the inclined portion 301 at one end facing the discharge port 341. The height of the inclined portion 301 becomes lower as it approaches the outlet 341. At this time, the vertical length h1 (see FIG. 3) of the edge dam 34 having the outlet 341 is greater than the vertical length h2 (see FIG. 3) of the other edge dam 34 without the outlet 341. The outlet 341 is larger than the doctor part 30 at the lowermost end of the edge dam 34. Here, the upper ends of the edge dams 34 are located at the same height with respect to the ground. Therefore, since the paste P accommodated on the doctor part 30 naturally flows along the inclined part 301 toward the discharge port 341, the paste P may be easily discharged.

The control valve 48 may be an automatic solenoid valve. The control valve 48 opens the guide tube 46 in the process of collecting the paste P, and operates after the paste P has been collected or after the paste collection box 20 is full. To close.

In FIG. 3, the discharge port 341 is provided in one edge dam 34 of the pair of edge dams 34, but as illustrated in FIG. 4, the discharge holes are provided in all of the pair of edge dams 34. A configuration in which 341 is provided is also possible. In this case, the doctor unit 30 may form the inclined portions 301 at both ends facing the discharge port 341, and the paste collection box 20 is disposed outside the pair of edge dams 34.

Assuming that there is no outlet 341 and the guide tube 46, the operator has to float and remove the remaining paste P by hand after the offset printing operation is completed. However, in the present embodiment, since the remaining paste P is discharged along the discharge hole 341 and the guide tube 46, workability can be improved. In addition, since the paste P can be collected and reused, the process cost can be reduced.

5 is a right side view of the stirring slider 22 and the stirring slider driving unit 24 of FIG. 1, and FIG. 6 is a perspective view of the stirring slider 22 of FIG. 5.

1, 5, and 6, the stirring slider 22 is positioned so that a part of the stirring slider 22 is buried in the paste P at the upper portion of the doctor part 30. The stirring slider 22 agitates the paste P in the offset printing process to increase the dispersibility of the paste P, and pushes the paste P toward the outlet 341 after the offset printing process is completed. do.

The stirring slider 22 is positioned to be exposed on the paste P accommodated on the doctor part 30. Therefore, in the offset printing process, the lower part of the stirring slider 22 is buried in the paste P, and the upper part of the stirring slider 22 is located above the paste P.

The stirring slider 22 moves along the axial direction (y-axis direction) of the gravure roll 16 between a pair of edge dams 34. The width of the stirring slider 22 is made smaller than the gap between the first guide plate 40 (see FIG. 2) and the gravure roll 16 (see FIG. 2). Therefore, the stirring slider 22 can move smoothly along the y-axis direction, without contacting the 1st guide plate 40 and the gravure roll 16. FIG.

The stirring slider 22 may be manufactured in the form of a flat plate as a whole. On the other hand, the stirring slider 22 may be formed to be convex or concave in the portion buried in the paste (P). In FIG. 5, the stirring slider 22 in the form of a plate is illustrated as an example, but the shape of the stirring slider 22 is not limited to the illustrated shape and may be variously modified.

The stirring slider 22 is formed of the material which is not corroded by the paste P and does not change the composition of the paste P. FIG. For example, the stirring slider 22 may be made of plastic or stainless steel sheet. In addition, a rubber shock absorbing member 52 may be provided at the lower end of the stirring slider 22 in contact with the doctor part 30. Therefore, when the stirring slider 22 moves on the doctor part 30, the friction with the doctor part 30 can be reduced.

The stirring slider drive 24 engages with the upper portion of the stirring slider 22 exposed over the paste P to reciprocate the stirring slider 22 along the axial direction (y-axis direction) of the gravure roll 16.

The stirring slider drive 24 may be mechanical. In the figure, the stirring slider drive 24 using the motor 54 and the gear shaft 56 is shown as an example. The stirring slider drive 24 is not limited to the structure shown, and the coupling structure with the power source and the stirring slider 22 can be easily modified in other ways.

The stirring slider drive 24 includes a gear shaft 56 passing through the stirring slider 22, a motor 54 generating power to rotate the gear shaft 56, and bearings supporting both ends of the gear shaft 56 ( 58, and a movement guide 60 positioned parallel to the gear shaft 56 and penetrating the stirring slider 22.

The stirring slider driver 24 may be installed on the pair of edge dams 34. To this end, a fixed block 62 is installed on the pair of edge dams 34, and a motor 54 and a bearing 58 are installed in the fixed block 62. And both ends of the movement guide 60 is fixed to the fixing block 62. Therefore, the stirring slider drive 24 can be firmly installed on the doctor part 30 and the pair of edge dams 34.

The stirring slider 22 has a 1st opening part 221 into which the gear shaft 56 is fitted, and the 2nd opening part 222 into which the movement guide 60 is fitted. A thread is formed on the sidewall of the first opening 221 to be screwed with the gear shaft 56. The second opening 222 is formed to have a diameter slightly larger than the diameter of the movement guide 60 to allow the stirring slider 22 to smoothly move along the movement guide 60.

When the gear shaft 56 rotates by the operation of the motor 54, the rotational force also acts on the stirring slider 22 geared with the gear shaft 56. By the way, since the movement guide 60 has penetrated the stirring slider 22, the rotation of the stirring slider 22 is forcibly prevented. Thus, the stirring slider 22 moves linearly along the movement guide 60 while being loosened or tightened with respect to the gear shaft 56. In this manner, the rotation of the gear shaft 56 can be switched to the linear motion of the stirring slider 22.

The stirring slider 22 is moved forward or backward by repeating the forward and reverse rotation of the motor 54. The stirring slider 22 can be reciprocated by the action of this stirring slider drive 24. The stirring slider 22 reciprocates in the offset printing process, and stirs the paste P. As shown in FIG. Therefore, drying of the paste P can be prevented and the dispersibility of the paste P can be improved, and offset printing quality can be improved.

In addition, the stirring slider 22 moves after the offset printing process is completed and pushes the remaining paste P toward the discharge port 341 provided in the edge dam 34. Therefore, since the operator can easily discharge the paste P through the stirring slider 22 that moves automatically without manually removing the paste P, workability can be improved through an automated process.

Although the present invention has been described above, it will be readily understood by those skilled in the art that various modifications and variations are possible without departing from the spirit and scope of the claims set out below.

1 is a perspective view schematically showing an offset printing apparatus according to an embodiment of the present invention.

FIG. 2 is a front view schematically illustrating the doctor unit and the gravure roll of FIG. 1.

FIG. 3 is a right side view schematically showing the doctor portion, a pair of edge dams, and a paste collecting container of FIG.

4 is a right side view schematically showing a modified embodiment of the doctor portion, a pair of edge dams, and a paste collection container of FIG.

FIG. 5 is a right side view of the stirring slider and the stirring slider drive of FIG. 1. FIG.

6 is a perspective view illustrating the stirring slider of FIG. 5.

Claims (15)

A paste supply unit for supplying paste, A gravure roll for forming a recess in the surface for accommodating the paste, A doctor unit which is adapted to temporarily receive the paste supplied from the paste supply unit and to provide it to the concave groove, and contacts the gravure roll to wipe off the paste on the surface of the gravure roll; A blanket roll in contact with the gravure roll to transfer the paste contained in the concave groove, and to print the transferred paste on a substrate; Paste collection box which is connected to the doctor unit and receives and stores the remaining paste after the printing is completed from the doctor unit Offset printing apparatus comprising a. The method of claim 1, The doctor unit, A doctor part in contact with the gravure roll, A guide part positioned between the paste supply unit and the doctor part to guide the paste supplied from the paste supply unit onto the doctor part; A pair of edge dams respectively installed at both ends of the doctor part to face each other Offset printing apparatus comprising a. The method of claim 2, At least one edge dam of the pair of edge dams discharge outlet is formed, the paste collection box is connected to the discharge outlet offset printing apparatus. The method of claim 3, And the outlet is located at the bottom of the edge dam. The method of claim 4, wherein And the doctor portion forms an inclined portion at an end portion facing the discharge opening, the height of which decreases as the closer to the discharge opening. The method of claim 5, The discharge port is formed in one edge dam of the pair of edge dams, The vertical length of the edge dam with the outlet is greater than the vertical length of the other edge dam without the outlet, And an upper end of the pair of edge dams positioned at the same height relative to the ground. The method of claim 3, A guide tube interconnecting said outlet and said paste collection bin, and A control valve installed in the guide tube to control opening and closing of the guide tube Offset printing apparatus further comprising. The method of claim 1, Offset printing apparatus further comprises a balance which is installed in the lower portion of the paste collection box to measure the weight of the paste. The method of claim 1, A stirring slider which is positioned above the doctor part and stirs and pushes the paste contained on the doctor part, and Stir slider drive unit coupled to the stirring slider to move the stirring slider along the axial direction of the gravure roll Offset printing apparatus further comprising. The method of claim 9, And the stirring slider is exposed over the paste received on the doctor portion. The method of claim 10, The stirring slider has a width smaller than the interval between the guide portion and the gravure roll. The method of claim 11, The stirring slider further comprises a buffer member fixed to the end in contact with the doctor portion. The method of claim 9, The stirring slider drive unit, A gear shaft penetrating the stirring slider, A motor for generating power to rotate the gear shaft; and A movement guide penetrating the stirring slider and positioned parallel to the gear shaft; Offset printing apparatus comprising a. The method of claim 13, And a fixed block disposed on the pair of edge dams, wherein the motor is mounted to the fixed block, and both ends of the gear shaft and both ends of the movement guide are supported by the fixed block. The method of claim 13, The stirring slider forms a first opening in which the gear shaft is fitted, and a second opening in which the movement guide is fitted. A thread is formed on the sidewall of the first opening, and the second opening is a diameter of the movement guide. Offset printing apparatus having a larger diameter.

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