JP2015024618A - Plate making device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve problems for example, when plate making is finished, a stencil sheet is stuck to a thermal head.SOLUTION: A plate making device 10 for plate making while transporting a stencil sheet 1 which is a roll-state by a TPH (thermal print head) 3 and a platen roller 4 is configured so that: after plate making in a previous process, when skew correction and positioning of the stencil sheet before start of plate making in a next process, the stencil sheet is sent and a master standby sensor 5 detects its tip end ((1) to (4)), and the platen roller is reversed and the TPH is lifted up for dissolving sticking of the stencil sheet and the TPH ((5)), and skew correction of the stencil sheet is performed by normal rotation of the platen roller ((6)). Then, using signal output of the master standby sensor 5, positioning of the stencil sheet is performed for plate making.

Description

  The present invention relates to a plate making apparatus that performs thermal perforation while transporting a stencil sheet sandwiched between a thermal head and a platen roller, and in particular, a problem that occurs due to the stencil sheet sticking to a thermal head after the completion of plate making. The means for solving is proposed.

  In a general plate making apparatus for making a stencil sheet, thermal piercing is performed while a belt-shaped stencil sheet fed from a roll-shaped stencil sheet is sandwiched and conveyed by a thermal head and a platen roller. Yes. In a stencil printing apparatus equipped with such a stencil making apparatus, stencil printing is performed by winding a stencil sheet that has been stenciled around a printing means such as a plate cylinder. A plate making apparatus or plate making printing apparatus using such a stencil sheet is disclosed in Patent Document 1 below.

JP-A-9-11600

  According to the knowledge of the applicant of the present application, when the plate making is completed in the plate making apparatus as described above, the thermal head may be moved away from the platen roller. This is because the platen roller is deformed by leaving the platen roller in contact with the thermal head for a long period of time, or the stencil paper sandwiched between the platen roller and the thermal head sticks to the thermal head. It is for preventing.

  However, after stencil printing, the stencil sheet may be already attached to the thermal head due to variations in the smoothness of the glass surface of the thermal head, the influence of the release agent applied to the stencil sheet, and the like. For this reason, if the thermal head is moved to a position away from the platen roller after the plate making, the stencil sheet adhered to the thermal head may be lifted together. As a result, there is a problem with the positioning of the leading edge of the stencil sheet, or when the stencil sheet is sandwiched by lowering the thermal head and contacting the platen roller again, the stencil sheet will be wrinkled or folded. Problems are likely to occur. If the thermal head and the stencil sheet stick together in this way, the stencil sheet cannot be transported normally during the next stencil making, resulting in poor transport and wasteful consumption of the stencil sheet. The problem that it takes extra time is likely to occur.

Hereinafter, the above problem will be described more specifically.
FIG. 7 is a timing chart of processes performed after the completion of plate making in the plate making apparatus proposed by the present inventor. FIG. 8 is a diagram of each part of the apparatus corresponding to each control time point 1) to 14) in the timing chart of FIG. It is a figure which shows a state, the position of stencil paper, etc. The technical contents shown in these figures were invented by the inventor of the present application, and the inventor of the present application does not consider that the technical contents are known techniques at the time of filing this application. The inventor of the present application has discovered the new problem for the first time and made the present invention in order to solve the problem, while making an effort to improve the technique shown in FIGS.

  FIGS. 7 and 8 show a state in which the stencil sheet (also referred to as a master) is cut with a cutter after the pre-process is made and is inclined with respect to the transport direction before the next process is started. This is a time series of operations that perform skew correction that corrects the orientation of the stencil sheet and sets the leading edge of the stencil sheet to a predetermined standby position. In this example, the process proceeds without any problem. Hereinafter, each control time point 1) to 14) will be described.

1) The pre-process plate making is completed, and the stencil sheet 1 is cut by the cutter 2.
2) The thermal head 3 (also referred to as a thermal print head; hereinafter abbreviated as TPH3) descends to sandwich the stencil sheet 1 with the platen roller 4, and the platen roller 4 rotates (forward) in the feed direction. The stencil sheet 1 is then sent downstream.
3) The leading edge of the stencil sheet 1 is detected by the master standby sensor 5, and the output of the master standby sensor 5 is turned on.
4) The platen roller 4 stops after a predetermined time has elapsed since the output of the master standby sensor 5 was turned on.

5) With the platen roller 4 stopped, the TPH 3 rises and leaves the stencil sheet 1.
6) The platen roller 4 rotates normally after a predetermined time has elapsed after the TPH 3 is separated from the stencil sheet 1. If the stencil sheet 1 is skewed, it is corrected by the rotation of the platen roller 4.

7) After the platen roller 4 is stopped, the TPH 3 is lowered to sandwich the stencil sheet 1.
8) The platen roller 4 rotates (reverses) in the return direction and pulls the stencil sheet 1 back to the upstream side.
9) When the stencil sheet 1 that has blocked the master standby sensor 5 is retracted and the leading edge thereof passes through the master standby sensor 5, the ON signal output from the master standby sensor 5 becomes the OFF signal.
10) The platen roller 4 is stopped after a predetermined time has elapsed since the signal of the master standby sensor 5 becomes the OFF signal.
11) After the platen roller 4 is stopped, the TPH 3 is raised after a predetermined time has elapsed.
12) After a predetermined time has elapsed, the TPH 3 is lowered to sandwich the stencil sheet 1, and then the stencil sheet 1 is fed by rotating the platen roller 4 forward after the predetermined time has elapsed.
13) The leading edge of the stencil sheet 1 is detected by the master standby sensor 5, and the platen roller 4 is stopped after a predetermined time has elapsed since the output of the master standby sensor 5 is turned on.
14) The TPH 3 rises to release the stencil sheet 1 and the stencil sheet 1 is made ready for the next stencil making.

  If the series of steps described above is performed without delay after the plate making in the previous step is completed, plate making in the next step can be started without any trouble. However, the applicant of the present application has discovered a new problem due to the problem that the stencil sheet 1 sticks to the thermal head 3 in the above invention.

  That is, the skew correction process in the above steps 5) and 6) and the subsequent returning process in 7) and 8) are actually phenomena because the stencil sheet 1 sticks to the thermal head. The problem of not progressing as shown in 8) 5) to 8) was discovered. Actually, as shown in 5) of FIG. 9, since the stencil sheet 1 is affixed to the TPH 3, when the TPH 3 is raised, the stencil sheet 1 is also lifted together, and the tip of the stencil sheet 1 is The master standby sensor 5 will come off. For this reason, the stencil sheet 1 is pulled back and passed through the master standby sensor 5 in a subsequent process, and the detection signal changes from ON to OFF, so that the leading end cannot be positioned. Further, since the stencil sheet 1 is lifted together with the TPH 3 and separated from the platen roller 4, as shown in 6) of FIG. 9, even if the platen roller 4 is rotated forward to perform skew correction, The rotational force of the roller 4 is not transmitted to the stencil sheet 1, and the skew of the stencil sheet 1 cannot be corrected. Further, as shown in 7) and 8) of FIG. 9, the stencil sheet 1 is lowered in a process of lowering the stencil sheet 1 between the platen roller 4 and reversing the platen roller 4 to pull the stencil sheet 1 back. There was also a problem that the base paper 1 was wrinkled.

  The present invention has been made in view of the problems first grasped in the plate making apparatus proposed by the applicant of the present invention as described above, and has problems caused by sticking of the stencil sheet to the thermal head. The purpose is to solve.

In order to achieve the above object, the plate making apparatus described in claim 1 is:
A platen roller that is driven to rotate;
A thermal head that is provided so as to be movable between a position in contact with the platen roller and a position away from the platen roller, and performs thermal perforation on the stencil sheet sandwiched between the platen roller that is rotationally driven;
Control means for driving the platen roller while moving the thermal head to a position away from the platen roller;
It is characterized by comprising.

The plate making apparatus described in claim 2 is the plate making apparatus according to claim 1,
When the platen roller is driven while moving the thermal head to a position away from the platen roller, the platen roller is driven to rotate at a speed higher than that during plate making.

According to the plate making apparatus described in claim 1, since the TPH is moved to a position away from the platen roller while the platen roller is rotationally driven after plate making or before plate making, the stencil paper was temporarily attached to the thermal head. However, since the stencil sheet is peeled off from the thermal head by the rotation of the platen roller and the movement of the TPH, the stencil sheet can be reliably separated from the thermal head. For this reason, there exists an effect that the various processes which should be performed after plate making or before plate making can be performed without trouble.

  According to the plate making apparatus described in claim 2, when the platen roller is driven while the thermal head is moved away from the platen roller, the platen roller is driven to rotate at a speed higher than that at the time of plate making. There is an effect that the effect of separating the base paper from the thermal head can be further ensured.

It is a schematic structure figure showing typically the structure of the plate making apparatus of the present invention. It is a control block diagram of the plate making apparatus of the present invention. FIG. 3 is a control timing chart of the leading edge feeding operation of the stencil sheet in the plate making apparatus of the first embodiment of the present invention. It is a figure which shows the state of each part of an apparatus corresponding to each control time 1) -14) in the timing chart of FIG. 3, the position of a stencil sheet, etc. FIG. 10 is a control timing chart of a stencil sheet leading-out operation in a plate making apparatus according to a second embodiment of the present invention. It is a figure which shows the state of each part of an apparatus corresponding to each control time 1) -14) in the timing chart of FIG. 5, the position of a stencil sheet, etc. FIG. 6 is a control timing chart of the stencil sheet leading-out operation in the plate making apparatus proposed by the present applicant. It is a figure which shows the state of each part of an apparatus corresponding to each control time 1) -14) in the timing chart of FIG. 7, the position of a stencil sheet, etc. FIG. 9 is a diagram showing a new problem grasped by the applicant of the present invention in the invention proposed by the applicant of the present invention shown in FIGS. 7 and 8.

The structure of the plate making apparatus 10 according to the first embodiment will be described with reference to FIGS. 1 and 2.
The plate making apparatus 10 of this embodiment uses a roll-shaped stencil sheet 1. The roll-shaped stencil sheet 1 is rotatably mounted on the support part 11 of the base paper storage part. The support unit 11 is provided with a damper that applies a force in the direction opposite to the pulling direction to the stencil sheet 1, and is configured so that an appropriate tension is applied to the stencil sheet 1 drawn out during the plate making.

  The stencil sheet 1 drawn from the roll is guided to the plate making unit 14 through the guide plate 13 and the guide roller 12. The plate making unit 14 includes a platen roller 4 disposed at a predetermined position, and a thermal head 3 (also referred to as a thermal print head, hereinafter abbreviated as TPH3) that sandwiches the stencil sheet 1 between the platen roller 4. Yes. The platen roller 4 is rotationally driven by a platen roller drive motor MP in either of two directions, a normal rotation for feeding the stencil sheet 1 in the downstream direction and a reverse rotation for returning the stencil sheet 1 in the upstream direction. The TPH 3 is movable between a position in contact with the platen roller 4 and an upper position away from the platen roller 4 and can be moved up and down freely by the driving force of the TPH drive motor MT.

  The cutter 2 is provided on the downstream side of the plate making unit 14. The cutter 2 includes a fixed tooth 2a provided at a predetermined position and a drive tooth 2b that moves relative to the fixed tooth 2a. By driving the drive teeth 2b with the cutter drive motor MC, the rear end of the stencil sheet 1 that has been subjected to the pre-making process can be cut and separated from the unstenciled stencil sheet 1 on the upstream side.

  A conveyance roller 6 is provided on the downstream side of the cutter 2. The transport roller 6 can be rotated forward or reverse by a transport roller drive motor MR driven in synchronization with the platen roller 4, and can transport or pull back the stencil sheet 1. As described above, the platen roller drive motor MP and the transport roller drive motor MR may be provided separately and driven in synchronization, but both rollers may be driven by a common drive motor.

  A master standby sensor 5 is provided on the downstream side of the transport roller 6. The master standby sensor 5 outputs an ON signal as a detection signal when the stencil sheet 1 is detected, and outputs an OFF signal as a non-detection signal when the stencil sheet 1 is not detected. The position of the front end portion of the stencil sheet 1 can be managed by the detection or non-detection signal of the master standby sensor 5. In the present embodiment, the standby position where the stencil sheet 1 is to be standby in preparation for the next plate making process is a position where the leading end of the stencil sheet 1 comes to a predetermined position on the downstream side of the master standby sensor 5, for example, 1 mm. It is.

  A plurality of pairs of conveying rollers 7 are further provided on the downstream side of the master standby sensor 5 so that the stencil sheet 1 made of the plate can be conveyed downstream. Although FIG. 1 shows two pairs of conveying rollers 7, FIG. 4 described later shows only one pair of conveying rollers 7 for convenience of illustration. Although not shown in detail, a printing device 15 having a printing unit such as a drum is provided on the downstream side of the plurality of pairs of transport rollers 7. The printed stencil sheet 1 supplied from the upstream plate making apparatus 10 to the printing apparatus 15 is wound around a peripheral surface of a drum which is a printing means provided with an ink supply mechanism. Then, the drum can be rotated, and printing paper sent from a paper supply unit (not shown) can be pressed against the surface of the drum by the pressing means to perform stencil printing on the printing paper.

The control means 20 of the plate making apparatus 10 of this embodiment will be described with reference to FIG.
Connected to the control means 20 which is a CPU constituted by a microprocessor or the like is a ROM 21 storing a control program and a RAM 22 for storing control information such as input information, timer measurement values, the number of steps of the motor to be driven, etc., as needed. Has been. In addition, the control means 20 includes a timer 23 that outputs a timing signal for managing time in position control of the stencil sheet 1 to be described later, the master standby sensor 5 that outputs an ON signal and an OFF signal, and an elevator An upper limit switch 24 that detects an upper limit position of the driven TPH 3 and outputs an upper limit signal; and a lower limit switch 25 that detects a lower limit position of the TPH 3, that is, a position where the TPH 3 contacts the platen roller 4 and outputs a lower limit signal. Each is connected.

  The control means 20 includes a motor control circuit 26 that drives the cutter drive motor MC described above, a motor control circuit 27 that drives the platen roller drive motor MP, and a motor control circuit 28 that drives the transport roller drive motor MR. The motor control circuits 29 for driving the TPH drive motor MT are respectively connected.

  The control means 20 obtains information from each of the timer 23, the master standby sensor 5, the TPH upper limit switch 24, and the TPH lower limit switch 25, and writes the necessary control information in the RAM 22 while using the control program of the ROM 21, etc. Necessary operation commands are output to the motor control circuits 26 to 29 that respectively drive the cutter drive motor MC, the platen roller drive motor MP, the transport roller drive motor MR, and the TPH drive motor MT.

  The control means 20 executes the control program, and after the stencil sheet 1 in the previous process is completed and the stencil sheet 1 is cut by the cutter 2, it is inclined with respect to the transport direction before starting the stencil process in the next process. A series of preparation steps are performed in which skew feeding correction is performed to correct the posture of the stencil sheet 1 and the cueing is performed to set the front end of the stencil sheet 1 to the standby position.

  With reference to FIG.3 and FIG.4, the preparatory process performed immediately after plate making in the plate making apparatus 10 of this embodiment is demonstrated. The control time points 1) to 14) shown in FIG. 3 correspond to the statuses of the apparatus and stencil sheet 1 shown in the respective FIGS. 1) to 14) in FIG. explain.

  1) The pre-process plate making is completed, and the stencil sheet 1 is cut by the cutter 2. The preceding stencil sheet 1 having been subjected to pre-making is conveyed downstream and used for printing. Thereafter, when the output of the master standby sensor 2 changes from the ON signal to the OFF signal, the platen roller 4 is rotated forward and the TPH 3 is lowered.

  2) The TPH 3 descends and the stencil sheet 1 is sandwiched between the platen roller 4 and the platen roller 4 rotates (forward) in the feeding direction to feed the stencil sheet 1 downstream.

  3) The leading edge of the stencil sheet 1 is detected by the master standby sensor 5, and the detection output of the master standby sensor 5 is turned on.

  4) The platen roller 4 stops after a predetermined time has elapsed since the output of the master standby sensor 5 was turned on. The leading edge of the stencil sheet 1 is set at a position 1 mm downstream of the master standby sensor 5.

  5) After a lapse of a predetermined time from the stop of the platen roller 4, the platen roller 4 starts to reverse and performs the “return” operation of the stencil sheet 1, and raises the TPH 3 while the platen roller 4 is reversely rotating. Since the TPH 3 is raised while rotating the platen roller 4, even if the stencil sheet 1 is stuck to the TPH 3, the stencil sheet 1 is peeled off from the TPH 3 by the reverse rotation of the platen roller 4 and the movement of the TPH 3. Therefore, the stencil sheet 1 can be reliably separated from the TPH 3. When the platen roller 4 is rotated in the reverse direction, a predetermined tension is applied to the stencil sheet 1 that is pulled in the return direction by the downstream conveying roller 6 sandwiching the stencil sheet 1 with a predetermined force. In this step, the front end of the stencil sheet 1 is kept at a position 1 mm downstream of the master standby sensor 5 by an arbitrary value set in anticipation of returning slightly upstream from the position 1 mm downstream of the master standby sensor 5. It is.

  In this step, the sticking between the stencil sheet 1 and the TPH 3 can be more reliably eliminated if the rotation speed of the platen roller 4 is made larger than that during plate making. However, although it depends on the type of stencil sheet 1 and the smoothness of the plate-making surface of TPH3, the limit is preferably about 1.1 to 1.2 times the rotational speed of the platen roller 4 during plate-making. If it is larger than this, the stencil sheet 1 may be wrinkled or folded.

  6) When the stencil sheet 1 is peeled off from the TPH 3, the platen roller 4 stops and further starts normal rotation. At this time, since the TPH 3 holds an upper position away from the platen roller 4, the free stencil sheet 1 receives a conveying force from the platen roller 4, and if it is skewed, the platen roller 4 rotates. The direction is corrected.

  7) After the platen roller 4 is stopped, the TPH 3 is lowered to sandwich the stencil sheet 1. At this time, since the stencil sheet 1 is flat on the platen roller 4, the stencil sheet 1 sandwiched between the TPH 3 and the platen roller 4 is not wrinkled or bent.

  8) The platen roller 4 rotates (reverses) in the return direction and pulls the stencil sheet 1 back to the upstream side. The stencil sheet 1 sandwiched between the TPH 3 and the platen roller 4 is not wrinkled or bent, and is held in a normal state, so that there is no hindrance to conveyance in the return direction.

  9) When the stencil sheet 1 that has blocked the master standby sensor 5 is retracted and the leading edge thereof passes through the master standby sensor 5, the signal output from the master standby sensor 5 changes from an ON signal to an OFF signal.

  10) The platen roller 4 is stopped after a predetermined time has elapsed since the signal of the master standby sensor 5 becomes the OFF signal. The position at which the stencil sheet 1 is stopped is a position where the front end of the stencil sheet 1 comes to a position of 1 mm + B (B is an arbitrary value set in advance) from the master standby sensor 5 to the upstream side.

  11) After the platen roller 4 is stopped, the TPH 3 is raised after a predetermined time has elapsed.

  12) After a predetermined time elapses, the TPH 3 is lowered to sandwich the stencil sheet 1 again, and then the platen roller 4 is rotated forward after the predetermined time elapses to feed the stencil sheet 1.

  13) The front end of the stencil sheet 1 is detected by the master standby sensor 5, and the platen roller 4 is stopped after a predetermined time has elapsed since the detection output of the master standby sensor 5 becomes the ON signal. At this time, the front end of the stencil sheet 1 is downstream of the master standby sensor 5 by a predetermined dimension (for example, 1 mm). This position is the standby position of the stencil sheet 1 waiting for the next plate making process.

  14) Thereafter, the TPH 3 is lifted to release the stencil sheet 1 and release the pressure on the stencil sheet 1, and the stencil sheet 1 is put on standby at the standby position in preparation for the next plate making.

Next, a second embodiment will be described with reference to FIGS.
The configuration of the second embodiment is the same as that of the first embodiment. The difference is that, in order to eliminate sticking of the stencil sheet 1 to the TPH 3, the rotation direction when the platen roller 4 is rotated while the TPH 3 is separated from the platen roller 4 is reversed in the first embodiment. On the other hand, the second embodiment is a forward rotation. Therefore, FIG. 5 shows the entire control timing chart of the second embodiment, but FIG. 6 showing the situation of the apparatus and the stencil sheet 1 shows the control points 5) and 6 in FIG. Only the figure corresponding to) is shown, and only the difference will be described. For other configurations, operations, etc., the illustration and description of the first embodiment are used.

  5) After a lapse of a predetermined time from the stop of the platen roller 4, the platen roller 4 starts to rotate forward and performs the "feed" operation of the stencil sheet 1, and raises the TPH 3 while the platen roller 4 is rotating forward. . Since the TPH 3 is raised while the platen roller 4 is normally rotated, even if the stencil sheet 1 is stuck to the TPH 3, the stencil sheet 1 is peeled off from the TPH 3 by the normal rotation of the platen roller 4 and the movement of the TPH 3. Therefore, the stencil sheet 1 can be reliably separated from the TPH 3. When the platen roller 4 is rotated forward, the damper of the support portion 11 holding the roll of the stencil sheet 1 gives a predetermined tension to the stencil sheet 1 that receives a force in the feeding direction. In this step, the front end of the stencil sheet 1 is kept at a position 1 mm downstream of the master standby sensor 5 by an arbitrary value set in anticipation of proceeding slightly downstream from the position 1 mm downstream of the master standby sensor 5. It is.

  6) When the stencil sheet 1 is peeled off from the TPH 3, the platen roller 4 continues to rotate forward. At this time, since the TPH 3 holds an upper position away from the platen roller 4, the free stencil sheet 1 receives a conveying force from the platen roller 4, and if it is skewed, the platen roller 4 rotates. The direction is corrected.

As described above, according to the plate making apparatus 10 of each embodiment, since the TPH 3 is moved to a position away from the platen roller 4 while the platen roller 4 is rotationally driven after plate making, the stencil sheet 1 is temporarily attached to the TPH 3. Even so, the stencil sheet 1 is surely peeled off from the TPH 3 by the rotation of the platen roller 4 and the movement of the TPH 3, and the subsequent skew correction can be reliably performed without any trouble. For this reason, it is possible to quickly prepare for the next plate making after completion of the plate making in the previous step, and in the next step, the time required from the start of plate making to the discharge of the first printed material (first print time) as much as possible The effect that it can shorten is acquired.
To “move the TPH 3 to a position away from the platen roller 4 while driving the platen roller 4 to rotate”, “to move the TPH 3 to a position away from the platen roller 4 and simultaneously start to rotate the platen roller 4. And “starting rotational driving of the platen roller 4 before moving the TPH 3 to a position away from the platen roller 4”.

1 ... Stencil paper 3 ... Thermal print head (TPH)
DESCRIPTION OF SYMBOLS 4 ... Platen roller 5 ... Master standby sensor 6 ... Conveyance roller 10 ... Plate making apparatus 20 ... Control means MP ... Platen roller drive motor MT ... Thermal head drive motor

Claims (2)

A platen roller that is driven to rotate;
A thermal head that is provided so as to be movable between a position in contact with the platen roller and a position away from the platen roller, and performs thermal perforation on the stencil sheet sandwiched between the platen roller that is rotationally driven;
Control means for driving the platen roller while moving the thermal head to a position away from the platen roller;
A plate making apparatus comprising: 2. The plate making according to claim 1, wherein when the platen roller is driven while the thermal head is moved away from the platen roller, the platen roller is rotationally driven at a speed higher than that at the time of plate making. apparatus.

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