JP2006213007A - Offset printing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent inferiority of the quality of printing by suppressing swinging in the width direction of the printing generated during the printing in offset printing. <P>SOLUTION: In a printing apparatus in which a blanket cylinder 8 is pivoted on a truck 7 horizontally moving in the printing direction on a guide 6 of a printing trestle 5, and when the truck 7 is moved, a printing plate 1 and a body 3 to be printed are rotated, an actuator A driving in the printing width direction and pushing the blanket cylinder 8 is equipped on both ends in the printing width direction of the truck 7. In addition, the position of the truck 7 on the printing trestle 5 and the amount of swinging of the truck 7 are measured at any time, and an operation controlling apparatus C indicating the amount of the swinging or an amount in which an optional amount is added to the amount of the swinging to the actuator A, is equipped, to instantaneously drive the actuator A to suppress the swinging. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an intaglio or letterpress offset printing apparatus used for color filter coloring patterns, pixel cell patterns such as plasma displays and liquid crystal displays, printing formation of alignment films of liquid crystal displays, and other thick film printing and overcoat printing. Regarding improvements.

When producing a color filter by a printing method, when a colored pattern is printed and formed on a flat plate-shaped substrate, generally, a blanket cylinder (roll-shaped rotating body) facing the fixed horizontal printing surface plate is a straight line. The reciprocating movement is performed, and printing is performed by rolling the printing plate or the substrate.
After supplying printing ink to the printing plate or blanket cylinder, the blanket cylinder is moved horizontally, and the printing plate or substrate is pressed between the horizontal printing surface plate and the blanket cylinder, and then supplied to the printing plate or blanket cylinder. Further, printing is performed by an offset printing apparatus in which the printing ink is transferred to a printing medium by a blanket (rubber elastic surface) wound around a blanket cylinder by an offset method.
As a color filter manufacturing method by the offset printing method, it has been reported in the following patent documents.
JP 7-43514 A JP-A-7-266532

As this type of offset printing apparatus, there is one having a configuration shown in a schematic side view of FIG. 3 and a schematic plan view of FIG.
A linear guide 106 (for example, a linear guide or a concave groove) is provided at both ends of the printing frame 105 formed of a base frame, and is fitted in the guide 106 so as to be fitted in the printing direction along the guide 106. A cart 107 that can move linearly is provided.

A blanket cylinder 108 is pivotally supported at the center of the carriage 107 through a bearing so as to be rotatable.
A bearer (pillow) 113 of the blanket cylinder 108 and a bearer 109 of the printing frame are provided on both sides of the blanket cylinder 108 and both sides of the printing frame 105, respectively.
At the time of printing, while the bearer 113 of the blanket cylinder 108 and the bearer 109 of the printing stand are in close contact with each other, the blanket cylinder 108 moves up and down with the carriage 107 while receiving the vertical movement of the blanker cylinder 108 on the bearer surface. Above, it rolls around the axis 112 of the blanket cylinder 108 to transfer the printing ink.

As a moving method of the carriage 107, the carriage 107 is fixed to a ball screw (not shown) and is moved by rotating the ball screw, the carriage 107 is moved by a linear motor (not shown), the carriage 107 is moved. Some pull a tow rope (not shown) connected to the.
In many cases, the pinion gear 114 is provided on the left and right sides of the blanket cylinder 108 and the rack gear 110 that meshes with the printing stand 105 is provided for the one that moves with the ball screw and the one that pulls the tow rope connected to the carriage 107.

  On the printing stand 105, a printing plate surface plate 102 for mounting and fixing the printing plate 101 and a printing body surface plate 104 for mounting and fixing the printing body 103 are arranged.

In the blanket cylinder 108, the bearers 113 provided on both sides need to move straight on the bearer 109 of the printing frame.
However, there is a case where the blanket cylinder 108 swings in the printing width direction for the following reasons.

One is influenced by bearers 113 and 109.
The support for the vertical movement of the blanket cylinder 108 is carried out on the bearer surface, and if the bearers 113 and 109 are slightly bent, they swing.

One effect is due to the undulation of the guide 106.
When the straightness of the guide 106 is undulated, the carriage 8 swings, and as a result, the blanket cylinder 108 swings while being supported by the carriage 8.

  For example, when the pinion gears 114 are provided on the left and right sides of the blanket cylinder 108 and the rack gear 110 is provided on the printing stand 105, the gap between the gear teeth (for example, about 1 μm to 10 μm, or More than that, a difference occurs in the tooth contact when the blanket cylinder 108 moves, and as a result, the blanket cylinder 108 swings.

For example, when transferring printing ink by applying pressure to a blanket (not shown) wound around the blanket cylinder 108, the blanket cylinder 108 swings if the surface of the blanket has waviness. .
Further, the blanket is a consumable item and needs to be replaced when it is deteriorated. However, the swinging state slightly changes at the time of replacement due to the difference in the waviness between the blankets.

  For example, the rocking state slightly changes due to variations in the thickness of the printing plate 101 and the substrate 103 or waviness in the surface.

  Such swinging of the blanket cylinder 108 during a printing operation causes a print image shape defect or a print registration defect in the print width direction or the print direction in the print image printed on the printing medium 103, resulting in poor print quality. Is generated.

When such a print quality defect occurs, when the pinion gear 114 is provided on both sides of the blanket cylinder 108 and the rack gear 110 is provided on the printing stand 105, the position of the rack gear 110 is determined in the printing direction or printing depending on intuition and experience. Increase the print quality accuracy by repeatedly moving in the width direction, checking the state of the print image after printing, re-estimating the movement direction and amount of movement of the rack gear 110 from that state, and moving the position. For a method of moving the carriage 107 with a linear motor, printing is performed by repeatedly checking the state of the print image after changing the speed control of the linear motor, and reviewing and changing the contents of the speed control change from that state. There are ways to increase the accuracy of quality.
In any case, when a print quality defect occurs, it is not a method that can be dealt with immediately, but generally a person who has specialized skills, knowledge, and experience over a period of several days is required.

  An object of the present invention is to solve such a problem, and it is easy to immediately eliminate a quality defect of a printed matter (color filter) caused by the blanket cylinder 108 swinging in the printing width direction. A printing apparatus is provided.

As shown in the schematic side view of FIG. 1 and the schematic plan view of FIG.
A printing platen 2 for mounting and fixing the printing plate 1;
A printing stand 5 provided with a printing body surface plate 4 on which the printing body 3 is placed and fixed;
A carriage 7 linearly reciprocating in the printing direction along guides 6 provided on the left and right of the printing stand 5;
An offset printing apparatus having a blanket cylinder 8 supported by a carriage 7 and moving together with the carriage 7 and rolling on the printing plate 1 and the printing medium 3,
The actuator A is fixed to both sides of the carriage 7 in the printing width direction, and includes an actuator A that precisely pushes the blanket cylinder 8 in the printing width direction.
A carriage position measuring device 11 for measuring the absolute position of the carriage 7 in the printing direction on the printing stand 5;
A swing amount measuring device B that measures the swing amount of the carriage 7 in the printing width direction, and an instruction to drive the actuator A by the swing amount or an amount obtained by adding an arbitrary instruction value to the swing amount at the position of the arbitrary carriage 7. Calculation control device C
It is characterized by providing.

According to the present invention, there is a precision actuator A that is fixed to both sides of the carriage 7 in the printing width direction and that precisely presses the blanket cylinder 8 from both sides in the printing width direction. Since the position and the amount of swing of the carriage 7 in the printing width direction at the position are grasped, an instruction to drive the actuator A immediately after the amount of swing or an amount obtained by adding an arbitrary instruction value to the swing amount can be automatically issued. 9 swell, guide 6 swell, gear tooth pitch shift, blanket swell, printing plate 1 and substrate 3 thickness variations, and other factors including subtle fluctuations of the carriage 7 You can control changes in movement.
As a result, it is possible to suppress print image formation defects and print registration defects in the print width direction that occur in the print image of the printing medium 3.

A schematic configuration of an offset printing apparatus according to the present invention is shown in FIGS.
On both sides of the carriage 7 in the printing width direction, there are provided precision actuators A that can be controlled by a precise reciprocating motion in the vertical direction in FIG. 2 by pressing the shaft core 12 of the blanket cylinder 8 in the printing width direction.
The precision actuator A is driven by a ball screw, a linear motor, etc., and is equipped with a laser length measuring device, a linear scale, etc., and accurately measures the driving amount of the precision actuator A itself.
The precision actuator A is also attached to a beam passed to the frame of the carriage 7 or a rigid plate that plays the same role.
Moreover, the structure which presses not the axial core 12 but the side surface of the blanket cylinder 8 is also considered.
The shape of the tip of the precision actuator A may be a rod shape or a plate shape.

In order to measure the position of the carriage 7 in the printing direction of the printing stand 5, a carriage position measuring instrument 11 such as a linear scale is provided.
Thereby, the position on the printing plate surface plate 2 and the to-be-printed body surface plate 4 of the blanket cylinder 8 pivotally supported by the cart 7 can be grasped.
The value of the cart position measuring device 11 is taken in by the arithmetic control device C as needed.

A swing amount measuring device B such as an autocollimator or a laser length measuring device is installed at one end in the printing direction of the printing apparatus and at any point on the carriage.
The oscillating amount measuring device B side or the other end is used as the origin of the oscillating amount measurement, and the oscillating amount in the printing width direction during the movement of the carriage 7 from one end to the other end is measured at any time. Capture.

  In the control arithmetic unit C, the position of the carriage 7 from the carriage position measuring device 11 is compared with the swing amount which is the value of the swing amount measuring device B, and a drive instruction is immediately given to the precision actuator A. A pushes the blanket cylinder 8 by the swing amount.

The instruction terminal D manually inputs an amount to drive the precision actuator A and a moving region of the carriage 7 that drives and holds the amount independently of the pitch corresponding to the swing amount.
The input value is registered in the control arithmetic device C, and the control arithmetic device C gives the precision actuator A the amount obtained by adding the value input at the instruction terminal D to the swing amount of the carriage 8 to the precision actuator A. Give drive instructions.

An embodiment of a printing apparatus according to the present invention will be described in detail with reference to the schematic diagrams of FIGS.
A linear guide 6 is provided at both ends of a printing frame 5 formed of a base frame, and a carriage 7 is provided that is fitted in the linear guide 6 and is linearly movable along the printing operation direction along the linear guide 6.

  The blanket cylinder 8 is rotatably supported on the frame of the carriage 8 via a bearing, and is rotated by a transmission (not shown) and an electric motor (not shown) attached to one end of the blanket cylinder 8. It is controlled by a controller (not shown) that controls the rotation speed and rotation direction of the electric motor, and is driven in the forward rotation direction and the reverse rotation direction.

A bearer 13 of the blanket cylinder 8 and a bearer 9 of the printing frame 5 are provided on both sides of the blanket cylinder 8 and both sides of the printing frame 5, respectively.
When printing, the bearer 13 of the blanket cylinder 8 and the bearer 9 of the printing stand 5 are in close contact with each other, and the blanket cylinder 8 is moved back and forth with the carriage 7 while receiving the vertical movement of the blanket cylinder 8 on the bearer surface. Above, it rolls around the axis 12 of the blanket cylinder 8 to transfer the printing ink.

As a moving system of the carriage 7, as an embodiment, the carriage 7 is fixed to a ball screw (not shown) and moved by rotating the ball screw.
What moves the trolley | bogie 7 with a linear motor, pulls the tow rope connected to the trolley | bogie 7, etc. can be implemented suitably. Pinion gears 14 are provided on the left and right sides of the blanket cylinder 8, and a rack gear 10 that meshes with the printing stand 5 is provided.
Also in this case, when the carriage 7 is moved by a linear motor, the pinion gear 14 and the rack gear 10 may not be provided.

On the printing stand 5, a printing plate surface plate 2 on which the printing plate 1 is placed and fixed, and a printing body surface plate 4 on which the printing material 3 is placed and fixed are arranged.
Although not shown, for example, a printing ink tray is placed and fixed as a partial mechanism of the printing ink supply mechanism.

On both sides in the printing width direction of the carriage, there are provided precision actuators A capable of reciprocating to push the axis 12 of the blanket cylinder 8 in the printing width direction.
For example, an actuator such as a linear actuator having a resolution of 0.05 μm and a driving accuracy of ± 0.5 μm is provided.
The resolution and driving accuracy are considered according to the required print quality.
In addition to the built-in encoder and return to its original origin position, a laser length measuring machine, linear scale, etc. are also provided to accurately measure and drive the actuator's own drive amount.

The precision actuator A is also attached to a beam passed to the frame of the carriage or a rigid plate that plays the same role.
Furthermore, the structure which pushes the side surface of the blanket cylinder 8 instead of the shaft core 12 is also considered.
Further, the shape of the tip of the precision actuator A may be a rod shape or a plate shape.

In order to measure the position of the carriage 7 in the printing direction of the printing stand 5, a linear scale which is the carriage position measuring device 11 is provided.
The position of the carriage 7 is taken in by the arithmetic control device C as needed.
In addition, it can implement also with the trolley | bogie position measuring device 11 other than a linear scale.

An autocollimator, which is one of the swing amount measuring devices B, is installed at one end of the printing stand 5 in the printing direction, which is the position before the printing operation of the printing apparatus, and a mirror for receiving a laser is installed at the upper part of the carriage 7.
The position before the printing operation of the printing apparatus is set as the origin of measurement of the fluctuation amount in the printing width direction, and the fluctuation amount in the printing width direction while the carriage 7 moves to the other end is measured at any time. take in.
In addition, it can implement also with the rocking | swiveling amount measuring apparatus B other than an autocollimator.
In the present embodiment, two autocollimators are installed on one end of the printing stand 5 on the same line perpendicular to the printing direction.

In the control arithmetic unit C, the position of the carriage 7 from the linear scale is compared with the swing amount from the autocollimator.
Immediately, a drive instruction is issued to the linear actuator which is the precision actuator A.
The linear actuator pushes the blanket cylinder 8 by an amount corresponding to the swinging amount to suppress the swinging.
As the swing amount, either the swing amount of one of the two autocollimators, the average of the two swing amounts, or a calculation method other than the average value may be used. The arithmetic device C calculates the driving amount.
When the printing apparatus is installed, the range in which the carriage 7 moves the printing platen 2 and the printing platen 4 is registered in the control arithmetic unit C, and printing at any point on the printing plate 1 and the printing plate 3 is performed. The position of the mount 5 can be compared.

Although the swing of the carriage 7 is suppressed by the above, the swell of the bearers 13 and 9, the swell of the guide 6, the gap between the gear teeth, the swell of the blanket, the variation in the thickness of the printing plate 1 and the printing medium 3. Is large, the blanket cylinder 8 may swing in a specific area independently of the carriage 7 due to the tolerance of the blanket cylinder 8 and the bearing that supports it.
As a result, the print image of the printing medium may not be transferred to a desired position in the specific area.
In this case, from a personal computer that is one of the instruction terminals D, apart from the pitch corresponding to the swing amount, the precision actuator A is shifted from the position where the print image should be or an amount to drive any precision actuator A. A specific area in the printing direction or an arbitrary printing direction area that has not been transferred to the position where the print image of the printing medium should be, is manually input as an area where the movement area of the carriage is converted.
The input value is registered in the control arithmetic unit C, and the precision actuator A is instructed to drive the precision actuator A by adding the value input at the instruction terminal D to the swing amount of the carriage 7. Press the blanket cylinder 8.
As a result, print image formation defects and print registration defects in the print width direction that occur in the print image of the printing medium 3 are suppressed.

  The structure of the printing ink supply mechanism in the printing apparatus of the present invention is not particularly limited, and a printing ink supply mechanism used in a known printing apparatus can be employed.

1 is a schematic side view of an offset printing apparatus according to claim 1 of the present invention. 1 is a schematic plan view of an offset printing apparatus according to claim 1 of the present invention. The outline side view of the conventional offset printing apparatus. FIG. 6 is a schematic plan view of a conventional offset printing apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,101 ... Printing plate 2,102 ... Printing platen surface plate 3,103 ... To-be-printed body 4,104 ... To-be-printed body surface plate 5,105 ... Printing stand 6,106 ... Guide 7, 107 ... Dolly 8,108 ... Blanket cylinders 9, 109 ... Print carrier bearers 10, 110 ... Rack gear 11 ... Dolly position measuring instrument 12, 112 ... Blanket cylinder axis 13, 113 ... Blanket cylinder bearers 14, 114 ... Pinion gear A ... Precision actuator B ... Swing amount measuring device C ... arithmetic control device D ... instruction terminal

Claims (1)

A printing platen for mounting and fixing the printing plate;
A printing stand provided with a printing body surface plate for mounting and fixing the printing body;
A carriage that reciprocates linearly in the printing direction along guides provided on both sides of the printing stand;
An offset printing apparatus comprising a blanket cylinder that is supported by a carriage and moves with the carriage and rolls on a printing plate and a printing medium,
An actuator that is fixed on both sides of the carriage in the printing width direction and precisely pushes the blanket cylinder in the printing width direction,
A carriage position measuring device for measuring the absolute position of the printing direction on the carriage printing stand,
A swing amount measuring device that measures the swing amount in the printing width direction of the carriage,
An arithmetic and control unit that gives an instruction to drive an actuator with an amount of swing or an amount obtained by adding an arbitrary instruction value to the amount of swing at an arbitrary position of the carriage,
An offset printing apparatus comprising:

Images