JPH0746529Y2 - Print alignment device for screen printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an apparatus for aligning a printing position between a screen plate and an object to be printed in a cylinder type screen printing machine.

[Prior Art] Conventionally, as shown in FIG. 12, in a cylinder type screen printing machine, printing papers F stacked in the automatic paper feeder 1 are arranged in the cylinder 3 on the paper feeding side around the cylinder 3. A paper feed tape 2 for paper is provided, and on the paper discharge side thereof, a print paper guide 11 for discharging the print paper F printed on the cylinder 3 from the cylinder 3 and a paper discharge tray 12 are provided.
Is provided. The cylinder 3 is reciprocally rotated in the arrow A direction or the arrow B direction in conjunction with the sector gear 7 which is swung via the connecting rod 6 as the crank 5 rotates. On the other hand, a screen plate 9 is disposed above the cylinder 3, and the screen plate 9 is reciprocally moved in the L arrow direction or the R arrow direction in conjunction with the reciprocating rotation of the cylinder 3.

The printing on the printing paper F is performed by holding the printing paper F distributed by the paper feed tape 2 by the paper claw 4 attached to the cylinder 3 and rotating the cylinder 3 in the direction of arrow A to print the printing paper F. This is performed by feeding F to the lower side of the screen plate 9 and pressing the screen plate 9 by the squeegee 10 to push out the ink on it.

When multicolor printing is performed on the same printing paper F using the screen printing machine as described above, only one color can be printed at a time, so printing is performed several times. At this time, in order to align the printing position of the second color with the printing paper F on which the first color has been printed, a mark for printing position alignment at the same time as the design on the printing paper F when printing the first color. Was printed, and the mounting position of the screen plate 9 was finely adjusted so as to match the mark on the screen plate 9 of the second color to align the printing positions of the first color and the second color. .

[Problems to be Solved by the Invention] In order to accurately align the alignment mark on the printing paper F on which the first color is printed with the mark on the screen plate 9 for the second color, the printing paper F And the screen plate 9 are closest to each other, that is, at the contact position with the screen plate 9 which is the apex of the cylinder 3, it is necessary to perform the alignment. Therefore, the operator slightly moves the cylinder 3 so that the positioning mark on the printing paper F placed on the cylinder 3 is located at the apex position of the cylinder 3, and then the mark on the screen plate 9 is aligned with this mark. It was necessary to adjust the mounting position of the screen plate 9 so as to do so.

However, while the operator sees through the contact position from above the printing machine, the operator actually moves the cylinder 3 slightly to print the printing paper F.
Even if it is attempted to visually check whether or not the mark of is located at the apex position of the cylinder 3, the screen plate 9 itself is an obstacle and cannot be seen, and the mark of the printing paper F and the screen plate 9 are not visible. There is a problem that it is necessary for a worker to have skill based on many years of experience and intuition in order to match the marks.

An object of the present invention is to solve the above-mentioned problems in the screen printing machine and to provide a printing position aligning apparatus for the screen printing machine, which can easily and reliably perform the positioning between the printing material and the screen plate. is there.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a cylinder for sending an object to be printed on a circumferential surface, and a cylinder that reciprocates in a plane above the cylinder in association with its reciprocating rotation. A cylinder-type screen printing machine that is equipped with a moving screen plate and presses the screen plate to print on a printing material sent to the lower side of the screen plate in synchronization with the reciprocating movement of the screen plate. A screen printing machine equipped with a control means for issuing a control signal when the printing position alignment mark that moves with the printing plate reaches the apex of the cylinder closest to the screen plate, and stopping the rotation of the cylinder based on this control signal. The printing alignment device of

[Operation] When the printing alignment is performed between the screen plate and the printing material, when the printing material moves together with the cylinder and the printing positioning mark of the printing material reaches the apex of the cylinder, the control means is based on the control signal. Stop the rotation of the cylinder. In this state, the screen plate is adjusted so that the print position alignment mark of the screen plate coincides with the print position alignment mark of the printing material at the apex of the cylinder.

[Embodiment] An embodiment of a cylinder type screen printer embodying the present invention will be described below with reference to the drawings.

<First embodiment> In the first embodiment shown in FIGS. 1 to 6, as shown in FIG. 1, the cylinder 3 is the center of the sheet feeding side (right side in the figure).
Is provided with a paper feed tape 2 on which the printing papers F as the objects to be printed, which are stacked on the automatic paper feeder 1, are placed on the circumferential surface of the cylinder 3, and on the paper discharge side (the left side in the figure). Is a printing paper guide 11 and a paper ejection tray 12 for ejecting the printing paper F printed on the cylinder 3 from the cylinder 3.
Is provided. A gear 8 is attached to the end of the cylinder 3, and the gear 8 is meshed with the sector gear 7. This sector gear 7 is a drive motor M
Since the crank 5 driven by (see FIG. 3) is swung via the connecting rod 6, the cylinder 3 is reciprocally rotated in the arrow A direction or the arrow B direction in conjunction with this. It is like this.

On the other hand, a screen plate 9 is arranged above the cylinder 3, which is operated by a mechanism (not shown).
L in the plane above the cylinder 3 in conjunction with the reciprocating rotation of
It is adapted to reciprocate in the arrow direction or the R arrow direction. The screen plate 9 is located above the screen plate 9.
A squeegee 10 and a doctor 13 are provided which can move up and down in conjunction with the reciprocating movement of 1 and pressurize the screen plate 9.

In particular, as can be seen from FIGS. 1 and 2, in the first embodiment, the gear 22 is attached to the end of the rotation center shaft 21 of the sector gear 7, and the output shaft of the potentiometer 22 is attached to this gear 22. A gear 24 to which 23a is attached is meshed, and the cylinder 3, the sector gear 7, the gear 22 of the rotation center shaft 21, and the gear 24 of the potentiometer 23 are interlocked. Then, the potentiometer 23 generates a voltage corresponding to the rotational position of the cylinder 3 to detect the rotational position of the cylinder 3.

Next, the electrical configuration of this embodiment will be described with reference to FIG.

The controller 25 has a central processing unit (CPU), a read-only memory (ROM) and a rewritable memory (RAM) built therein. The potentiometer 23 is connected to the input side of the controller 25 so that the controller 25 can input the rotational position of the cylinder 3 as a voltage value. Further, a set switch 26 is connected to the input side of the controller 25, and an operator adjusts the mounting position of the screen plate 9, so that the controller 25 can be instructed to start the automatic positioning operation. .

On the other hand, the drive motor M is connected to the output side of the controller 25 so that the controller 25 can drive and stop it. The controller 25 stores in advance a voltage value indicating a rotational position for aligning the cylinder 3 as a control program and setting data. The input data from the potentiometer 23 is constantly compared and calculated with the setting data, and the calculation is performed. A control signal is output to the drive motor M based on the result.

The operation and effect of the screen printing machine configured as described above will be described.

In a normal printing operation, the cylinder 3 is rotated in the direction of arrow B to a certain position in accordance with the synchronized reciprocating motion of the cylinder 3 and the screen plate 9, and the paper attached to the cylinder 3 is rotated. After the eating claw 4 grips the printing paper F, it is inverted in the direction of arrow A. At this time, the squeegee 10 is lowered when the paper-feeding claw 4 passes the apex X of the cylinder 3, and as shown in FIG. Printing paper F pushed out and sent to the lower side of the screen plate 9
Print on the surface of.

When the cylinder 3 is rotated in the direction of the arrow A and the paper catching pawl 4 is opened in front of the printing paper guide 11 as shown by the phantom line in FIG. 4, the printing paper F becomes the printing paper as shown in FIG. It flows over the guide 11, is placed on the paper discharge table 12 arranged on the paper discharge side of the cylinder 3, and is discharged. At this time, cylinder 3
Is rotated in the direction of arrow A to a certain position as shown in FIG. 5, and then is inverted in the direction of arrow B, and the screen plate 9 is moved to a certain position in the direction of arrow L as shown in FIG. After being moved, it is moved back in the direction of the arrow R. As the screen plate 9 moves in the direction of the arrow R, the squeegee 10 ascends and the doctor 13 descends to return the ink on the screen plate 9. After that, cylinder 3 is again B
It is rotated to a fixed position in the direction of the arrow, and printing is performed by repeating the same operation as described above.

After the first color is printed on the printing paper F as described above, when the color is changed and the second color is printed, the second color screen plate 9 and the first color are printed. Paper F
The print position alignment between and is performed in the following manner. That is, when the set switch 26 is pressed, the controller 25 drives the drive motor M. Along with this, the cylinder 3 is rotated, and after the paper-feeding claw 4 grips the printing paper F on the paper feed tape 2, it is rotated again in the direction of arrow A. During this time, the rotational position of the cylinder 3 is constantly input to the controller 25 by the potentiometer 23. And
As shown in FIG. 6, when the mark G attached to the central portion in the feeding direction of the printing paper F placed on the cylinder 3 comes to the apex X of the cylinder 3, the controller 25 causes the cylinder 3 to move.
It is determined that the rotational position data of No. 3 coincides with the previously stored setting data, and a control signal is output to the drive motor M, and the drive motor M is stopped by this signal to rotate the cylinder 3. Stops.

Therefore, when the rotation of the cylinder 3 is stopped, the printing position alignment mark G of the printing paper F is apex X of the cylinder 3.
Automatically, and in this state, the printing position alignment mark H at the center of the second color screen plate 9 in the moving direction.
Between the second color screen plate 9 and the printing paper F on which the first color is printed by simply adjusting the so as to match the printing alignment mark G of the printing paper F at the vertex X of the cylinder 3. The printing position can be reliably and easily adjusted.

<Second Embodiment> In the second embodiment shown in FIGS. 7 and 8, instead of the potentiometer 23 in the first embodiment, the sector gear 7 swings as shown by the phantom line in FIG. A limit switch 28 is provided as a reversal position detecting means that comes into contact with the left end position, and the limit switch 28 is connected to the input side of the controller 25 as shown in FIG. Further, a timer 29 is connected to the controller 25 so that the drive motor M can be driven or stopped according to a time schedule.

Therefore, when the set switch 26 is pushed, the controller 25 drives the drive motor M, so that the sector gear 7 is swung and the cylinder 3 is swung. When the sector gear 7 swings and reaches the leftmost position, that is, when the cylinder 3 reaches a position where it cannot further rotate clockwise (reverse position to counterclockwise rotation), the sector gear 7 Press the limit switch 28. Then, when the sector gear 7 slightly reverses and rotates in the clockwise direction and the contact between the limit switch 28 and the sector gear 7 is released, the controller 25 detects the fall of the signal from the limit switch 28. And timer 29
Operate. The timer 29 is a preprogrammed time, that is, at the above-mentioned inverted position of the cylinder 3, the paper-feeding claw 4 grips the printing paper F, and the cylinder 3 rotates so that the printing position alignment mark G is attached to the printing paper F. When the time for reaching the apex X of the cylinder 3 has passed, a time-up signal is output to the controller 25. Then, the controller 25 receiving this signal outputs a control signal to the drive motor M and stops it, so that the printing position alignment mark G of the printing paper F is located at the apex X of the cylinder 3 as in the first embodiment. Can be matched.

<Third Embodiment> In the third embodiment shown in FIGS. 9 to 11, instead of the timer 29 in the second embodiment, an angle measuring means is provided at the end of the rotation center shaft 21 of the sector gear 7. A rotary encoder 31 is provided. This rotary encoder 31
Is composed of a disk 31a having a large number of equally spaced slits attached to the rotation center shaft 21, and a main body 31b that generates a pulse signal each time the detection light passes through the slits of the disk 31a. Then, as shown in FIG. 11, the rotary encoder 31 is connected to the input side of the controller 25 so that the number of pulses corresponding to the rotation angle of the rotation center shaft 21 can be input to the controller 25.

Therefore, when the set switch 26 is pushed, the controller 25 drives the drive motor M, so that the sector gear 7 is swung and the cylinder 3 is swung. When the sector gear 7 swings to the leftmost position, that is, when the cylinder 3 reaches a position where it cannot further rotate clockwise (reverse position to counterclockwise rotation), the sector gear 7 Presses the limit switch 28. Then, when the sector gear 7 slightly reverses and rotates in the clockwise direction and the contact between the limit switch 28 and the sector gear 7 is released, the controller 25 detects the fall of the signal from the limit switch 28. And rotary encoder
The counting of pulse signals input from 31 is started. The controller 25 controls the pre-programmed count number, that is, the paper catcher 4 at the reverse position of the cylinder 3.
Grips the printing paper F, and the cylinder 3 rotates to enumerate the count number corresponding to the rotation angle until the printing alignment mark G attached to the printing paper F reaches the apex X of the cylinder 3. At this time, the controller 25 outputs a control signal to the drive motor M and stops it, so that the printing position alignment mark G of the printing paper F can be aligned with the apex X of the cylinder 3 as in the first embodiment.

In addition to the above-described three embodiments, for example, a reflecting mirror may be attached to a part of the outer surface of the sector gear 7, and a photoelectric switch having an integrated light emitter / receiver may be provided in parallel with the sector gear 7. This photoelectric switch is a sector gear 7
Light is cast on the orbit in which the reflecting mirror oscillates in accordance with the oscillation of the. Then, when the cylinder 3 rotates to reach the position where the printing alignment mark G attached to the printing paper F reaches the apex X of the cylinder 3, the light emitted from the photoelectric switch is reflected by the reflecting mirror. At the same time, the drive of the drive motor M may be stopped when the photoelectric switch receives the reflected light. In such a case, the sensor is not limited to the photoelectric switch, but may be a pair of contact switches provided on the outer surface of the sector gear 7 and at a position parallel thereto.

Alternatively, a mark that can be detected by the photoelectric switch is printed on the printing paper F separately from the printing alignment mark G, and the cylinder 3 is rotated so that the printing alignment mark G on the printing paper F is printed. The photoelectric switch may detect the above-mentioned mark and stop the drive motor M when the position reaches the apex X of the cylinder 3.

Further, a printing position alignment mark G is provided above the screen plate 9.
It is also possible to dispose a mark sensor for detecting that the driving motor M is stopped by the mark sensor when the mark G reaches the apex X of the cylinder 3.

[Advantages of the Invention] According to the printing alignment device of the screen printing machine of the present invention, the printing alignment mark of the printing material can be automatically aligned with the apex of the cylinder. Even if it does not exist, there exists an outstanding effect that the printing position of a to-be-printed material and a screen plate can be performed simply and reliably.

[Brief description of drawings]

1 to 6 show a first embodiment of the present invention, and FIG. 1 is a front view showing the outline of a screen printer and an automatic paper feeder, and FIG.
FIG. 4 is a partial plan view showing the vicinity of the potentiometer, FIG. 3 is a block diagram showing an electrical configuration, FIG. 4 is a partial front view showing a state during printing operation, and FIG. 5 is a portion showing another state during printing operation. Front view, FIG. 6 is an explanatory view showing a print alignment state, FIGS. 7 and 8 show a second embodiment of the present invention, FIG. 7 is a front view showing an outline of a screen printing machine, and FIG. FIG. 9 is a block diagram showing an electrical configuration, FIGS. 9 to 11 show a third embodiment of the present invention, FIG. 9 is a front view showing the outline of a screen printing machine, and FIG. 10 is a partial plan view showing the vicinity of a rotary encoder. FIG. 11 is a block diagram showing the electrical configuration, and FIG. 12 is a front view showing the outline of a conventional screen printing machine and automatic paper feeder. 3 ... Cylinder, 9 ... Screen plate, F ... Printing paper as a printing object, G, H ... Marks for printing alignment,
X ... Apex.

Claims (1)

[Scope of utility model registration request] 1. A cylinder (3) for sending a material to be printed (F) on a circumferential surface and a screen plate (9) which reciprocates in a plane above the cylinder (3) in association with its reciprocating rotation. ) And is synchronized with the reciprocating movement of the screen plate (9), the screen plate (9) is pressed against the substrate (F) sent to the lower side of the screen plate (9) for printing. In the cylinder type screen printing machine to be performed, the print alignment mark (G) of the printing medium (F) moving together with the cylinder (3) reaches the apex (X) of the cylinder (3) closest to the screen plate (9). By the way, a printing position alignment device for a screen printing machine, which is provided with a control means for issuing a control signal and stopping the rotation of the cylinder (3) based on the control signal.